149 results on '"Renfeng Li"'
Search Results
2. Study on fracture mechanical properties and mechanism of engineered cementitious composites (ECC) after high temperature
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Liangqin Wu, Zhiyong Zhu, Tianqian Wu, Renfeng Li, Zhenpeng Yu, Qiang Feng, and Dongyi Xie
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Engineered cementitious composites (ECC) ,High temperature ,PE fiber content ,Fracture mechanical properties ,Failure mechanism ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The low melting point characteristics of organic fibers restrict the utilization of ECC in engineering applications. In this paper, the fracture mechanical properties of ECC were studied considering temperature and polyethylene fiber content, and the crack propagation rule and potential mechanism of ECC were clarified by using digital image correlation (DIC) technology and microscopic testing technology. The following conclusions are mainly obtained through the study. When the fiber content is 0 %, with the increase of temperature, the unstable fracture load, initial fracture toughness and unstable fracture toughness of the specimen are all reduced, while the fracture energy increases first and then decreases. When the fiber content is 0.5 %, 1 % and 1.5 %, the fracture parameters (unstable fracture load, fracture energy, initial fracture toughness and unstable fracture toughness) of the specimens decrease with the increase of temperature, and the decrease of the fracture parameters of the specimens is more obvious especially at 400℃ and later. The higher the PE fiber content, the more the fracture parameter is reduced by the temperature effect. The fracture parameters of the specimens increased significantly with the increase of PE fiber content at both room temperature/20℃ and 200℃, while the fracture parameters of the specimens decreased with the increase of fiber content when the temperature was not lower than 400°C, but the decrease was not significant. The results of the DIC technique showed that, with the increase of temperature, the crack initiation stage is advanced, the rapid crack development period is delayed. The development trend of crack length of the specimen is slowed down. At the same time, the mechanism of high temperature on the deterioration of ECC fracture mechanical properties under different PE fiber content was revealed. The results of this paper provide a theoretical basis for the safety assessment and analysis of ECC in engineering structural applications after fire.
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- 2024
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3. Ferroptosis-related lncRNA NRAV affects the prognosis of hepatocellular carcinoma via the miR-375-3P/SLC7A11 axis
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Ke Zong, Caifeng Lin, Kai Luo, Yilei Deng, Hongfei Wang, Jianfei Hu, Shi Chen, and Renfeng Li
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lncRNA ,Ferroptosis ,Predictive models ,NRAV ,miR-375-3P/SLC7A11 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Ferroptosis has important value in cancer treatment. It is significant to explore the new ferroptosis-related lncRNAs prediction model in Hepatocellular carcinoma (HCC) and the potential molecular mechanism of ferroptosis-related lncRNAs. We constructed a prognostic multi-lncRNA signature based on ferroptosis-related differentially expressed lncRNAs in HCC. qRT-PCR was applied to determine the expression of lncRNA in HCC cells. The biological roles of NRAV in vitro and in vivo were determined by performing a series of functional experiments. Furthermore, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to confirm the interaction of NRAV with miR-375-3P. We identified 6 differently expressed lncRNAs associated with the prognosis of HCC. Kaplan–Meier analyses revealed the high-risk lncRNAs signature associated with poor prognosis of HCC. Moreover, the AUC of the lncRNAs signature showed utility in predicting HCC prognosis. Further functional experiments show that the high expression of NRAV can strengthen the viciousness of HCC. Interestingly, we found that NRAV can enhance iron export and ferroptosis resistance. Further study showed that NRAV competitively binds to miR-375-3P and attenuates the inhibitory effect of miR-375-3P on SLC7A11, affecting the prognosis of patients with HCC. In conclusion, We developed a novel ferroptosis-related lncRNAs prognostic model with important predictive value for the prognosis of HCC. NRAV is important in ferroptosis induction through the miR-375-3P/SLC7A11 axis.
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- 2024
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4. Targeting EBV Episome for Anti-Cancer Therapy: Emerging Strategies and Challenges
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Febri Gunawan Sugiokto and Renfeng Li
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Epstein–Barr virus ,cancer ,episome ,reactivation ,anti-cancer therapy ,CRISPR ,Microbiology ,QR1-502 - Abstract
As a ubiquitous human pathogen, the Epstein–Barr virus (EBV) has established lifelong persistent infection in about 95% of the adult population. The EBV infection is associated with approximately 200,000 human cancer cases and 140,000 deaths per year. The presence of EBV in tumor cells provides a unique advantage in targeting the viral genome (also known as episome), to develop anti-cancer therapeutics. In this review, we summarize current strategies targeting the viral episome in cancer cells. We also highlight emerging technologies, such as clustered regularly interspersed short palindromic repeat (CRISPR)-based gene editing or activation, which offer promising avenues for selective targeting of the EBV episome for anti-cancer therapy. We discuss the challenges, limitations, and future perspectives associated with these strategies, including potential off-target effects, anti-cancer efficacy and safety.
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- 2025
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5. Development of a visual detection method of porcine deltacoronavirus using loop-mediated isothermal amplification
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Renfeng Li, Wenyan Cao, Jiakang Yuan, Linyue Li, Yanlin Zhou, Fangyu Wang, Ziliang Wang, and Xiangqin Tian
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porcine ,deltacoronavirus ,loop-mediated isothermal amplification ,visualization ,detection ,Microbiology ,QR1-502 - Abstract
The emergence of porcine deltacoronavirus (PDCoV) presents a significant threat to both human and animal health due to its ability to cause highly contagious enteric diseases. This underscores the crucial need for timely and accurate diagnosis to facilitate effective epidemiological investigation and clinical management. This research aimed to establish a visual detection method based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) for PDCoV testing. In this study, six pairs of primers were designed according to the conserved sequences of PDCoV ORF1a/b genes. The primer sets and parameters that affect LAMP reaction were optimized. The visual RT-LAMP method was developed by incorporating methyl red into the optimized reaction system, it exclusively detected PDCoV without cross-reactivity with other viruses and the detection limits for PDCoV could reach 10 copies/μL. In comparison with RT-PCR for testing 132 clinical samples, the relative specificity and sensitivity of the visual RT-LAMP were found to be 99.2 and 100%, respectively, with a concordance rate of 99.2% and a kappa value of 0.959, indicating that the visual RT-LAMP is a reliable method for the application of PDCoV detection in clinical samples.
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- 2024
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6. Diverse associations between pancreatic intra-, inter-lobular fat and the development of type 2 diabetes in overweight or obese patients
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Lihui Wang, Yinghao Li, Renfeng Li, Jinwen Luan, Kaiming Cao, Tiancheng Liu, Haiyang Hu, Shanshan Chen, Le Bu, Longhua Liu, Hongzhi Wang, and Qing Lu
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obesity ,T2DM ,mDixon MRI ,pancreas fat quantification ,intra-lobular fat ,inter-lobular fat ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Pancreatic fat is associated with obesity and type 2 diabetes mellitus (T2DM); however, the relationship between different types of pancreatic fat and diabetes status remains unclear. Therefore, we aimed to determine the potential of different types of pancreatic fat accumulation as a risk factor for T2DM in overweight or obese patients. In total, 104 overweight or obese patients were recruited from January 2020 to December 2022. The patients were divided into three groups: normal glucose tolerance (NGT), impaired fasting glucose or glucose tolerance (IFG/IGT), and T2DM. mDixon magnetic resonance imaging (MRI) was used to detect pancreatic fat in all three groups of patients. The pancreatic head fat (PHF), body fat (PBF), and tail fat (PTF) in the IFG/IGT group were 21, 20, and 31% more than those in the NGT group, respectively. PHF, PBF, and PTF were positively associated with glucose metabolic dysfunction markers in the NGT group, and inter-lobular fat volume (IFV) was positively associated with these markers in the IFG/IGT group. The areas under the receiver operating characteristic curves for PHF, PBF, and PTF (used to evaluate their diagnostic potential for glucose metabolic dysfunction) were 0.73, 0.73, and 0.78, respectively, while those for total pancreatic volume (TPV), pancreatic parenchymal volume, IFV, and IFV/TPV were 0.67, 0.67, 0.66, and 0.66, respectively. These results indicate that intra-lobular pancreatic fat, including PHF, PTF, and PBF, may be a potential independent risk factor for the development of T2DM. Additionally, IFV exacerbates glucose metabolic dysfunction. Intra-lobular pancreatic fat indices were better than IFV for the diagnosis of glucose metabolic dysfunction.
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- 2024
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7. Targeted eradication of EBV-positive cancer cells by CRISPR/dCas9-mediated EBV reactivation in combination with ganciclovir
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Febri Gunawan Sugiokto and Renfeng Li
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EBV ,latency ,reactivation ,CRISPR/dCas9 activation ,CMER ,ganciclovir ,Microbiology ,QR1-502 - Abstract
ABSTRACT Epstein-Barr virus (EBV) is a ubiquitous human tumor virus that establishes lifelong, persistent infections in B cells. The presence of EBV in cancer cells presents an opportunity to target these cells by reactivating the virus from latency. In this study, we developed a novel approach for EBV reactivation termed clustered regularly interspaced short palindromic repeats (CRISPR)/dCas9-mediated EBV reactivation (CMER) strategy. Using modified CRISPR-associated protein 9 (dCas9) fused with VP64, we designed 10 single guide RNAs (sgRNAs) to target and activate the EBV immediate-early gene promoter. In Akata Burkitt lymphoma cells, 9 out of 10 CMER sgRNAs effectively reactivated EBV. Among these, CMER sgRNA-5 triggered robust reactivation across various cell types, including lymphoma, gastric cancer, and nasopharyngeal carcinoma cells. Importantly, the combination of CMER and ganciclovir selectively eliminated EBV-positive cells, regardless of their cell origin. These findings indicate that targeted virus reactivation by CMER, combined with nucleoside analog therapy, holds promise for EBV-associated cancer treatment.IMPORTANCEThis study explores a novel strategy called clustered regularly interspaced short palindromic repeats (CRISPR)/dCas9-mediated Epstein-Barr virus (EBV) reactivation (CMER) to reactivate the Epstein-Barr virus in cancer cells. EBV is associated with various cancers, and reactivating EBV from latency offers a potential therapeutic strategy. We utilized an enzymatically inactive CRISPR-associated protein 9 (dCas9) fused with VP64 and designed 10 single guide RNAs to target the EBV immediate-early gene promoter. Nine of these sgRNAs effectively reactivated EBV in Burkitt lymphoma cells, with CMER sgRNA-5 demonstrating strong reactivation across different cancer cell types. Combining CMER with ganciclovir selectively eliminated EBV-positive cells, showing promise for EBV-associated cancer treatment.
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- 2024
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8. SUMOylation of the m6A reader YTHDF2 by PIAS1 promotes viral RNA decay to restrict EBV replication
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Febri Gunawan Sugiokto, Farjana Saiada, Kun Zhang, and Renfeng Li
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PIAS1 ,YTHDF2 ,restriction factor ,Epstein-Barr virus ,SUMOylation ,m6A ,Microbiology ,QR1-502 - Abstract
ABSTRACT YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2) is a member of the YTH protein family that binds to N6-methyladenosine (m6A)-modified RNA, regulating RNA stability and restricting viral replication, including Epstein-Barr virus (EBV). PIAS1 is an E3 small ubiquitin-like modifier (SUMO) ligase known as an EBV restriction factor, but its role in YTHDF2 SUMOylation remains unclear. In this study, we investigated the functional regulation of YTHDF2 by PIAS1. We found that PIAS1 promotes the SUMOylation of YTHDF2 at three specific lysine residues (K281, K571, and K572). Importantly, PIAS1 synergizes with wild-type YTHDF2, but not a SUMOylation-deficient mutant, to limit EBV lytic replication. Mechanistically, YTHDF2 lacking SUMOylation exhibits reduced binding to EBV transcripts, leading to increased viral mRNA stability. Furthermore, PIAS1 mediates SUMOylation of YTHDF2’s paralogs, YTHDF1 and YTHDF3, to restrict EBV replication. These results collectively uncover a unique mechanism whereby YTHDF family proteins control EBV replication through PIAS1-mediated SUMOylation, highlighting the significance of SUMOylation in regulating viral mRNA stability and EBV replication.IMPORTANCEm6A RNA modification pathway plays important roles in diverse cellular processes and viral life cycle. Here, we investigated the relationship between PIAS1 and the m6A reader protein YTHDF2, which is involved in regulating RNA stability by binding to m6A-modified RNA. We found that both the N-terminal and C-terminal regions of YTHDF2 interact with PIAS1. We showed that PIAS1 promotes the SUMOylation of YTHDF2 at three specific lysine residues. We also demonstrated that PIAS1 enhances the anti-EBV activity of YTHDF2. We further revealed that PIAS1 mediates the SUMOylation of other YTHDF family members, namely, YTHDF1 and YTHDF3, to limit EBV replication. These findings together illuminate an important regulatory mechanism of YTHDF proteins in controlling viral RNA decay and EBV replication through PIAS1-mediated SUMOylation.
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- 2024
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9. Numerical Analysis on Effect of Structural Parameters on Flow Field and Internal Trajectory in Gas–Steam Ejection Systems
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Bing Liu, Renfeng Li, Xiaohan Chen, Jinlan Gou, Bangming Li, and Guigao Le
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gas–steam ejection ,structural parameters ,shock wave characteristics ,multiphase flow ,internal trajectory ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
This paper aims to study the influence of the structure of spray holes and throats on the flow field and the internal trajectory of the gas–steam ejection device. The compressible Navier–Stokes equations, discrete ordinate methods and RNG k-ε turbulence model are utilized to simulate the two-phase flow of the rocket gas with multispecies and the water sprays. The comparison between numerical results and experimental data confirms the accuracy and effectiveness of this model. The simulation analysis on the cases of the ejection process with multiple spray hole diameters, number of spray holes, total spray area, and throat diameter are conducted. The shock wave structure inside the gas–steam ejection device is examined. The simulation results show that, instead of the spray hole diameter and number, the total spray area and secondary nozzle throat diameter are the key factors that affect the flow field and internal trajectory of the gas–steam ejection device. Under the existing spray structure, the maximum number of spray holes is 300 to achieve the stability of the flow field and internal ballistic trajectory of gas–steam ejection devices. By comparing the throat diameters of multiple secondary nozzles, it was found that the minimum throat diameter of the secondary nozzles should be no less than 100 mm. The results could be valuable for the design of gas–steam ejection devices.
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- 2023
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10. PIAS1 potentiates the anti-EBV activity of SAMHD1 through SUMOylation
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Farjana Saiada, Kun Zhang, and Renfeng Li
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SAMHD1 ,PIAS1 ,Restriction factor ,Epstein-Barr virus ,Cytomegalovirus ,SUMOylation ,Biotechnology ,TP248.13-248.65 ,Biology (General) ,QH301-705.5 ,Biochemistry ,QD415-436 - Abstract
Abstract Background Sterile alpha motif and HD domain 1 (SAMHD1) is a deoxynucleotide triphosphohydrolase (dNTPase) that restricts the infection of a variety of RNA and DNA viruses, including herpesviruses. The anti-viral function of SAMHD1 is associated with its dNTPase activity, which is regulated by several post-translational modifications, including phosphorylation, acetylation and ubiquitination. Our recent studies also demonstrated that the E3 SUMO ligase PIAS1 functions as an Epstein-Barr virus (EBV) restriction factor. However, whether SAMHD1 is regulated by PIAS1 to restrict EBV replication remains unknown. Results In this study, we showed that PIAS1 interacts with SAMHD1 and promotes its SUMOylation. We identified three lysine residues (K469, K595 and K622) located on the surface of SAMHD1 as the major SUMOylation sites. We demonstrated that phosphorylated SAMHD1 can be SUMOylated by PIAS1 and SUMOylated SAMHD1 can also be phosphorylated by viral protein kinases. We showed that SUMOylation-deficient SAMHD1 loses its anti-EBV activity. Furthermore, we demonstrated that SAMHD1 is associated with EBV genome in a PIAS1-dependent manner. Conclusion Our study reveals that PIAS1 synergizes with SAMHD1 to inhibit EBV lytic replication through protein–protein interaction and SUMOylation.
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- 2021
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11. The Value of Circulating Tumor Cells in the Prognosis and Treatment of Pancreatic Cancer
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Kai Luo, Xiangkun Wang, Xudong Zhang, Zhongyuan Liu, Shuai Huang, and Renfeng Li
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circulating tumor cell ,pancreatic carcinoma ,EMT ,prognosis ,circulating tumor cell (CTCs) ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
In the past few decades, tumor diagnosis and treatment theory have developed in a variety of directions. The number of people dying from pancreatic cancer increases while the mortality rate of other common tumors decreases. Traditional imaging methods show the boundaries of pancreatic tumor, but they are not sufficient to judge early micrometastasis. Although carcinoembryonic antigen (CEA) and carbohydrate antigen19-9 (CA19-9) have the obvious advantages of simplicity and minimal invasiveness, these biomarkers obviously lack sensitivity and specificity. Circulating tumor cells (CTCs) have attracted attention as a non-invasive, dynamic, and real-time liquid biopsy technique for analyzing tumor characteristics. With the continuous development of new CTCs enrichment technologies, substantial progress has been made in the basic research of CTCs clinical application prospects. In many metastatic cancers, CTCs have been studied as an independent prognostic factor. This article reviews the research progress of CTCs in the treatment and prognosis of pancreatic cancer.
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- 2022
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12. The immunoregulation effect of tumor microenvironment in pancreatic ductal adenocarcinoma
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Jingchang Zhang, Renfeng Li, and Shuai Huang
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tumor microenvironment ,immunotherapy ,immunosuppression ,PDAC ,immune checkpoint inhibitor ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Pancreatic cancer has the seventh highest death rate of all cancers. The absence of any serious symptoms, coupled with a lack of early prognostic and diagnostic markers, makes the disease untreatable in most cases. This leads to a delay in diagnosis and the disease progresses so there is no cure. Only about 20% of cases are diagnosed early. Surgical removal is the preferred treatment for cancer, but chemotherapy is standard for advanced cancer, although patients can eventually develop drug resistance and serious side effects. Chemoresistance is multifactorial because of the interaction among pancreatic cancer cells, cancer stem cells, and the tumor microenvironment (TME). Nevertheless, more pancreatic cancer patients will benefit from precision treatment and targeted drugs. This review focuses on the immune-related components of TME and the interactions between tumor cells and TME during the development and progression of pancreatic cancer, including immunosuppression, tumor dormancy and escape. Finally, we discussed a variety of immune components-oriented immunotargeting drugs in TME from a clinical perspective.
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- 2022
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13. Preparation and characterisation of monoclonal antibodies against deoxynivalenol
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Li Han, Yuetao Li, Jinqing Jiang, Renfeng Li, Guoying Fan, Zhuang Lei, Haojie Wang, Ziliang Wang, and Wenju Zhang
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anti-deoxynivalenol ,artificial antigen ,monoclonal antibody ,characterisation analysis ,Animal culture ,SF1-1100 - Abstract
To prepare broad-spectrum and specific monoclonal antibodies (mAb) against deoxynivalenol (DON), DON-BSA was synthesised by the carbonyl diimidazole method as an artificial antigen to immunise Balb/C mice, and the coated DON-OVA was synthesised by the carbodiimide method to detect anti-DON antibodies. Monoclonal antibodies were screened by indirect ELISA and indirect competitive ELISA. A hybridoma cell line (4F3) capable of stably secreting DON antibody was obtained. The titre of antibody in the culture supernatant was 1:1.28 × 103, and the titre of the ascites antibody was 1:3.2 × 105. The monoclonal antibody homology was IgG1/λ. The half inhibitory concentration (IC50) of DON was 9.84 ng/mL. The cross-reaction rates with 3-Ac-DON and 15-Ac-DON were 60.44% and 52.04%, respectively, but no cross-reaction with other mycotoxins was observed. The results showed that the anti-DON monoclonal antibodies prepared in this experiment could recognise not only DON but also 3-Ac-DON and 15-Ac-DON, which could provide materials for the next step to establish a method to detect DON and its similar compounds.Highlights This study demonstrated that an artificial antigen was synthesised by carbonyl diimidazole method, and a novel broad-spectrum, high affinity monoclonal antibody was developed. The anti-DON mAb developed in this study has better sensitivity, moreover the antibody was sensitive to DON and its derivatives. Therefore, it could be used for simultaneous monitoring of three mycotoxins. Results of this study will further lay the foundation for the establishment of immunological assays for the total amount of similar compounds.
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- 2020
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14. Oxysterol-Binding Protein 2 Promotes Pancreatic Ductal Adenocarcinoma Progression Through Epithelial-Mesenchymal Transition
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Shuai Huang, Xudong Zhang, Kai Luo, Li Jiang, Jianhua Jiang, and Renfeng Li
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epithelial–mesenchymal transition ,oxysterol-binding protein 2 ,pancreatic ductal adenocarcinoma ,migration ,invasion ,proliferation ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Oxysterol-binding protein 2 (OSBP2) is crucial for promoting the growth and development of cancers; however, its effects on pancreatic ductal adenocarcinoma (PDAC) are still unclear. Here, we report that OSBP2 is an efficient tumor-associated protein to lead to extremely malignant characteristics in PDAC. We discovered that increased OSBP2 expression in primary tumors was associated with shorter survival in PDAC patients. Therefore, we used immunohistochemistry (IHC) to analyze the levels of OSBP2 expression in PDAC tissues and adjacent paracancerous tissues. We used wound healing and Transwell assays to evaluate the effects of OSBP2 on PDAC cell (ASPC-1 and BXPC-3) migration and invasion, respectively, and CCK-8 and Annexin V/PI double staining to evaluate the effects of OSBP2 on PDAC cell proliferation and apoptosis, respectively. Western blotting was used to analyze the effect of OSBP2 on the PDAC cell phenotype. We also explored the effect of OSBP2 on chemosensitivity to gemcitabine (GEM) and 5-fluorouracil (5-FU). We validated these findings in an in vivo mouse model. The data show that OSBP2 overexpression promoted PDAC cell migration, invasion, proliferation and chemotherapy resistance, and decreased apoptosis. OSBP2 overexpression downregulated E-cadherin expression and upregulated N-cadherin, vimentin, Snail, Slug, ZEB1, and β-catenin expression. Taken together, our findings indicated that OSBP2 was overexpressed in PDAC and that upregulation of OSBP2 may promote PDAC progression. Therefore, OSBP2 may have potential diagnostic and therapeutic value in PDAC.
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- 2022
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15. CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle
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Apurva T. Prabhakar, Claire D. James, Dipon Das, Raymonde Otoa, Matthew Day, John Burgner, Christian T. Fontan, Xu Wang, Sarah H. Glass, Andreas Wieland, Mary M. Donaldson, Molly L. Bristol, Renfeng Li, Anthony W. Oliver, Laurence H. Pearl, Brian O. Smith, and Iain M. Morgan
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Microbiology ,QR1-502 - Abstract
Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitroin vivo
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- 2021
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16. Caspases Switch off the m6A RNA Modification Pathway to Foster the Replication of a Ubiquitous Human Tumor Virus
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Kun Zhang, Yucheng Zhang, Yunash Maharjan, Febri Gunawan Sugiokto, Jun Wan, and Renfeng Li
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reactivation ,lytic replication ,restriction factor ,m6A RNA modification ,YTHDF2 ,METTL3 ,Microbiology ,QR1-502 - Abstract
ABSTRACT The methylation of RNA at the N6 position of adenosine (m6A) orchestrates multiple biological processes to control development, differentiation, and cell cycle, as well as various aspects of the virus life cycle. How the m6A RNA modification pathway is regulated to finely tune these processes remains poorly understood. Here, we discovered the m6A reader YTHDF2 as a caspase substrate via proteome-wide prediction, followed by in vitro and in vivo validations. We further demonstrated that cleavage-resistant YTHDF2 blocks, while cleavage-mimicking YTHDF2 fragments promote, the replication of a common human oncogenic virus, Epstein-Barr virus (EBV). Intriguingly, our study revealed a feedback regulation between YTHDF2 and caspase-8 via m6A modification of CASP8 mRNA and YTHDF2 cleavage during EBV replication. Further, we discovered that caspases cleave multiple components within the m6A RNA modification pathway to benefit EBV replication. Our study establishes that caspase disarming of the m6A RNA modification machinery fosters EBV replication. IMPORTANCE The discovery of an N6-methyladenosine (m6A) RNA modification pathway has fundamentally altered our understanding of the central dogma of molecular biology. This pathway is controlled by methyltransferases (writers), demethylases (erasers), and specific m6A binding proteins (readers). Emerging studies have linked the m6A RNA modification pathway to the life cycle of various viruses. However, very little is known regarding how this pathway is subverted to benefit viral replication. In this study, we established an unexpected linkage between cellular caspases and the m6A modification pathway, which is critical to drive the reactivation of a common tumor virus, Epstein-Barr virus (EBV).
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- 2021
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17. Associations between forkhead box l2 expression and ovary development in laying hens
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Shouping ZHANG, Xiaojing XIA, Lirong WANG, Renfeng LI, Meng YANG, and Sanhu WANG
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foxl2 ,follicle ,ovary ,laying ,poultry ,Veterinary medicine ,SF600-1100 - Abstract
Make sure healthy ovary or follicle is critical for extending egg laying performance in poultry. Transcription factor forkhead box L2 (FOXL2) gene have key role in regulate development of ovary. In the present research, different aged Hy-line Brown hens were maintained to explore relationships between ovarian developing and FOXL2 expression. Through histological observation, different quantities of follicles from various phases of age were observed. It was displayed that FOXL2 expression and number mature follicle were increased as the days of age increased and then decreased. In comparison, the expression of FOXL2 in hypothalamus and eyelid were remained in a relative stable level. Taken together, these data in our research establish a framework for understanding the potential functions of FOXL2 in regulate chicken ovarian developing and may provide a new perspective on the theory and practice to increase egg production or others.
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- 2019
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18. Heat transfer enhancement and field synergy analysis of vacuum collector tube with inserted rotor
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Zhi Geng, Jifeng Gao, Haochen Liu, Ziyuan Mo, Yujiong Gu, Renfeng Li, Lina Zhang, Zhenghe Wang, Li Liu, and Xiang Zhang
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Physics ,QC1-999 - Abstract
Aiming at the large heat loss inside the traditional trough-type vacuum solar heat collecting tube, a new type of spiral three-blade rotor structure was designed and inserted into the inner tube side of the heat collecting tube. Based on the principle of fluid dynamics and field synergy, a mathematical model of the three governing equations of the fluid in the tube was established. Numerical simulations of the heat transfer and flow in the flow field in the two types of collector tubes with or without interpolated rotors were performed. Performance comparisons were made in terms of velocity field, pressure field, temperature field, and field synergy coupling ability. The results of the comprehensive evaluation index of heat transfer performance were finally given. The research shows that the PEC value continues to become larger with the increase in the inlet flow rate, from an initial value of 1.63 to a final value of 2.69. The heat transfer performance enhancement advantage of the new type vacuum heat collector tube is obviously greater than the disadvantage of flow resistance, and the comprehensive performance is better.
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- 2020
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19. Point-of-Care Tests for Rapid Detection of Porcine Epidemic Diarrhea Virus: A Systematic Review and Meta-Analysis
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Renfeng Li, Xiangqin Tian, Junzeng Pang, Linyue Li, Jiakang Yuan, Zhuangzhuang Tian, and Ziliang Wang
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porcine epidemic diarrhea virus ,point-of-care tests ,lateral flow immunochromatography assay ,nucleic acid isothermal amplification ,systematic review ,meta-analysis ,Microbiology ,QR1-502 - Abstract
The timely and accurate diagnosis of porcine epidemic diarrhea virus (PEDV) infection is crucial to reduce the risk of viral transmission. Therefore, the objective of this review was to evaluate the overall diagnostic accuracy of rapid point-of-care tests (POCTs) for PEDV. Studies published before 7 January 2022 were identified by searching PubMed, EMBASE, Springer Link, and Web of Science databases, using subject headings or keywords related to point of care and rapid test diagnostic for PEDV and PED. Two investigators independently extracted data, rated risk of bias, and assessed the quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The bivariate model and the hierarchical summary receiver operating characteristic (HSROC) model were used for performing the meta-analysis. Threshold effect, subgroup analysis, and meta-regression were applied to explore heterogeneity. Of the 2908 records identified, 24 eligible studies involving 3264 specimens were enrolled in the meta-analysis, including 11 studies on evaluation of lateral flow immunochromatography assay (ICA)-based, and 13 on nucleic acid isothermal amplification (NAIA)-based POCTs. The overall pooled sensitivity, specificity and diagnostic odds ratio (DOR) were 0.95 (95% CI: 0.92–0.97), 0.96 (95% CI 0.88–0.99) and 480 (95% CI 111–2074), respectively; for ICA-based POCTs and the corresponding values for NAIA-based, POCTs were 0.97 (95% CI 0.94–0.99), 0.98 (95% CI 0.91–0.99) and 1517 (95% CI 290–7943), respectively. The two tests showed highly comparable and satisfactory diagnostic performance in clinical utility. These results support current recommendations for the use of rapid POC tests when PEDV is suspected.
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- 2022
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20. B Cell Receptor Activation and Chemical Induction Trigger Caspase-Mediated Cleavage of PIAS1 to Facilitate Epstein-Barr Virus Reactivation
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Kun Zhang, Dong-Wen Lv, and Renfeng Li
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Biology (General) ,QH301-705.5 - Abstract
Summary: Epstein-Barr virus (EBV) in tumor cells is predominately in the latent phase, but the virus can undergo lytic reactivation in response to various stimuli. However, the cellular factors that control latency and lytic replication are poorly defined. In this study, we demonstrated that a cellular factor, PIAS1, restricts EBV lytic replication. PIAS1 depletion significantly facilitated EBV reactivation, while PIAS1 reconstitution had the opposite effect. Remarkably, we found that various lytic triggers promote caspase-dependent cleavage of PIAS1 to antagonize PIAS1-mediated restriction and that caspase inhibition suppresses EBV replication through blocking PIAS1 cleavage. We further demonstrated that a cleavage-resistant PIAS1 mutant suppresses EBV replication upon B cell receptor activation. Mechanistically, we demonstrated that PIAS1 acts as an inhibitor for transcription factors involved in lytic gene expression. Collectively, these results establish PIAS1 as a key regulator of EBV lytic replication and uncover a mechanism by which EBV exploits apoptotic caspases to antagonize PIAS1-mediated restriction. : The life cycle of Epstein-Barr virus (EBV) is tightly regulated by cellular factors. Zhang et al. identify PIAS1 as a critical host factor that suppresses EBV lytic replication. Upon B cell receptor activation or chemical perturbation, EBV hijacks host caspases to cleave and inactivate PIAS1 for efficient replication. Keywords: Epstein-Barr virus, Kaposi’s sarcoma-associated herpesvirus, latency, reactivation, B cell receptor activation, lytic induction, caspase, PIAS1, cleavage, apoptosis
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- 2017
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21. Local structure of liquid gallium under pressure
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Renfeng Li, Luhong Wang, Liangliang Li, Tony Yu, Haiyan Zhao, Karena W. Chapman, Yanbin Wang, Mark L. Rivers, Peter J. Chupas, Ho-kwang Mao, and Haozhe Liu
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Medicine ,Science - Abstract
Abstract In situ high energy X-ray pair distribution function (PDF) measurements, microtomography and reverse Monte Carlo simulations were used to characterize the local structure of liquid gallium up to 1.9 GPa. This pressure range includes the well-known solid-solid phase transition from Ga-I to Ga-II at low temperature. In term of previous research, the local structure of liquid gallium within this domain was suggested a mixture of two local structures, Ga I and Ga II, based on fitting experimental PDF to known crystal structure, with a controversy. However, our result shows a distinctly different result that the local structure of liquid gallium resembles the atomic arrangement of both gallium phase II and III (the high pressure crystalline phase). A melting mechanism is proposed for Ga, in which the atomic structure of phase Ι breaks up at the onset of melting, providing sufficient free volume for atoms to rearrange, to form the melt.
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- 2017
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22. Long Noncoding RNA AFAP1-AS1 Promoted Tumor Growth and Invasion in Cholangiocarcinoma
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Xu Lu, Chuang Zhou, Renfeng Li, Yilei Deng, Longshuan Zhao, and Wenlong Zhai
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Long non-coding RNAs ,AFAP1-AS1 ,CCA ,Proliferation ,Invasion ,Physiology ,QP1-981 ,Biochemistry ,QD415-436 - Abstract
Background: Long non-coding RNAs (lncRNAs) have been shown to play important roles in a wide range of pathophysiological processes, including cancer progression. Our previous study has shown that AFAP1-AS1 was upregulated and acted as an oncogene in hepatocellular carcinoma. However, the expression and biological functions of lncRNA AFAP1-AS1 in intrahepatic cholangiocarcinoma (CCA) remains largely unknown. Methods: The expression level of AFAP1-AS1 was measured in 56 pairs of human cholangiocarcinoma tumor tissues and corresponding adjacent normal bile duct tissues. The correlation between AFAP1-AS1 and the clinicopathological features were evaluated by chi-square test. The effects of AFAP1-AS1 on CCA cells were determined by CCK-8 assay, clone formation assay, flow cytometry and transwell assay. Finally, to determine the effect of AFAP1-AS1 on tumor growth in vivo, AFAP1-AS1 knockdowned CCLP-1 cells were subcutaneously into nude mice to evaluate tumor growth. Results: In this study, we found that lncRNA AFAP1-AS1 was increased in CCA tissues and patients with high AFAP1-AS1 expression had a shorter overall survival. SiRNA-mediated AFAP1-AS1 knockdown significantly decreased cell proliferation of the CCA cells, with downregulation of C-myc and Cycling D1 in vitro. Furthermore, AFAP1-AS1 silencing inhibited cell migration partly due to decrease the expression of MMP-2 and MMP-9. In addition, CCLP-1 cells with AFAP1-AS1 knockdown were injected into nude mice to investigate the effect of AFAP1-AS1 on the tumorigenesis in vivo. Conclusions: Taken together, our findings suggested that AFAP1-AS1 might promote the CCA progression and provided a novel potential therapeutic target for CCA.
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- 2017
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23. SAMHD1 Regulates Human Papillomavirus 16-Induced Cell Proliferation and Viral Replication during Differentiation of Keratinocytes
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Claire D. James, Apurva T. Prabhakar, Raymonde Otoa, Michael R. Evans, Xu Wang, Molly L. Bristol, Kun Zhang, Renfeng Li, and Iain M. Morgan
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SAMHD1 ,differentiation ,host-pathogen interactions ,life cycle ,papillomavirus ,viral replication ,Microbiology ,QR1-502 - Abstract
ABSTRACT Human papillomaviruses induce a host of anogenital cancers, as well as oropharyngeal cancer (HPV+OPC); human papillomavirus 16 (HPV16) is causative in around 90% of HPV+OPC cases. Using telomerase reverse transcriptase (TERT) immortalized foreskin keratinocytes (N/Tert-1), we have identified significant host gene reprogramming by HPV16 (N/Tert-1+HPV16) and demonstrated that N/Tert-1+HPV16 support late stages of the viral life cycle. Expression of the cellular dNTPase and homologous recombination factor sterile alpha motif and histidine-aspartic domain HD-containing protein 1 (SAMHD1) is transcriptionally regulated by HPV16 in N/Tert-1. CRISPR/Cas9 removal of SAMHD1 from N/Tert-1 and N/Tert-1+HPV16 demonstrates that SAMHD1 controls cell proliferation of N/Tert-1 only in the presence of HPV16; the deletion of SAMHD1 promotes hyperproliferation of N/Tert-1+HPV16 cells in organotypic raft cultures but has no effect on N/Tert-1. Viral replication is also elevated in the absence of SAMHD1. This new system has allowed us to identify a specific interaction between SAMHD1 and HPV16 that regulates host cell proliferation and viral replication; such studies are problematic in nonimmortalized primary keratinocytes due to their limited life span. To confirm the relevance of our results, we repeated the analysis with human tonsil keratinocytes (HTK) immortalized by HPV16 (HTK+HPV16) and observed the same hyperproliferative phenotype following CRISPR/Cas9 editing of SAMHD1. Identical results were obtained with three independent CRISPR/Cas9 guide RNAs. The isogenic pairing of N/Tert-1 with N/Tert-1+HPV16, combined with HTK+HPV16, presents a unique system to identify host genes whose products functionally interact with HPV16 to regulate host cellular growth in keratinocytes. IMPORTANCE HPVs are causative agents in human cancers and are responsible for around of 5% of all cancers. A better understanding of the viral life cycle in keratinocytes will facilitate the development of novel therapeutics to combat HPV-positive cancers. Here, we present a unique keratinocyte model to identify host proteins that specifically interact with HPV16. Using this system, we report that a cellular gene, SAMHD1, is regulated by HPV16 at the RNA and protein levels in keratinocytes. Elimination of SAMHD1 from these cells using CRISPR/Cas9 editing promotes enhanced cellular proliferation by HPV16 in keratinocytes and elevated viral replication but not in keratinocytes that do not have HPV16. Our study demonstrates a specific intricate interplay between HPV16 and SAMHD1 during the viral life cycle and establishes a unique model system to assist exploring host factors critical for HPV pathogenesis.
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- 2019
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24. Conserved Herpesvirus Protein Kinases Target SAMHD1 to Facilitate Virus Replication
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Kun Zhang, Dong-Wen Lv, and Renfeng Li
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Biology (General) ,QH301-705.5 - Abstract
Summary: To ensure a successful infection, herpesviruses have developed elegant strategies to counterbalance the host anti-viral responses. Sterile alpha motif and HD domain 1 (SAMHD1) was recently identified as an intrinsic restriction factor for a variety of viruses. Aside from HIV-2 and the related simian immunodeficiency virus (SIV) Vpx proteins, the direct viral countermeasures against SAMHD1 restriction remain unknown. Using Epstein-Barr virus (EBV) as a primary model, we discover that SAMHD1-mediated anti-viral restriction is antagonized by EBV BGLF4, a member of the conserved viral protein kinases encoded by all herpesviruses. Mechanistically, we find that BGLF4 phosphorylates SAMHD1 and thereby inhibits its deoxynucleotide triphosphate triphosphohydrolase (dNTPase) activity. We further demonstrate that the targeting of SAMHD1 for phosphorylation is a common feature shared by beta- and gamma-herpesviruses. Together, our findings uncover an immune evasion mechanism whereby herpesviruses exploit the phosphorylation of SAMHD1 to thwart host defenses. : Herpesviruses have evolved elegant strategies to dampen the host anti-viral responses. Zhang et al. discover a mechanism by which herpesviruses evade SAMHD1-mediated host defenses through phosphorylation, expanding the functional repertoire of viral protein kinases in herpesvirus biology. Keywords: Epstein-Barr virus, cytomegalovirus, conserved herpesvirus protein kinases, infection, reactivation, lytic replication, phosphorylation, SAMHD1, restriction factor, dNTPase
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- 2019
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25. Interferon regulatory factor 8 regulates caspase-1 expression to facilitate Epstein-Barr virus reactivation in response to B cell receptor stimulation and chemical induction.
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Dong-Wen Lv, Kun Zhang, and Renfeng Li
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Interferon regulatory factor 8 (IRF8), also known as interferon consensus sequence-binding protein (ICSBP), is a transcription factor of the IRF family. IRF8 plays a key role in normal B cell differentiation, a cellular process that is intrinsically associated with Epstein-Barr virus (EBV) reactivation. However, whether IRF8 regulates EBV lytic replication remains unknown. In this study, we utilized a CRISPR/Cas9 genomic editing approach to deplete IRF8 and found that IRF8 depletion dramatically inhibits the reactivation of EBV upon lytic induction. We demonstrated that IRF8 depletion suppresses the expression of a group of genes involved in apoptosis and thus inhibits apoptosis induction upon lytic induction by B cell receptor (BCR) stimulation or chemical induction. The protein levels of caspase-1, caspase-3 and caspase-8 all dramatically decreased in IRF8-depleted cells, which led to reduced caspase activation and the stabilization of KAP1, PAX5 and DNMT3A upon BCR stimulation. Interestingly, caspase inhibition blocked the degradation of KAP1, PAX5 and DNMT3A, suppressed EBV lytic gene expression and viral DNA replication upon lytic induction, suggesting that the reduced caspase expression in IRF8-depleted cells contributes to the suppression of EBV lytic replication. We further demonstrated that IRF8 directly regulates CASP1 (caspase-1) gene expression through targeting its gene promoter and knockdown of caspase-1 abrogates EBV reactivation upon lytic induction, partially through the stabilization of KAP1. Together our study suggested that, by modulating the activation of caspases and the subsequent cleavage of KAP1 upon lytic induction, IRF8 plays a critical role in EBV lytic reactivation.
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- 2018
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26. Phosphoproteomic Profiling Reveals Epstein-Barr Virus Protein Kinase Integration of DNA Damage Response and Mitotic Signaling.
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Renfeng Li, Gangling Liao, Raja Sekhar Nirujogi, Sneha M Pinto, Patrick G Shaw, Tai-Chung Huang, Jun Wan, Jiang Qian, Harsha Gowda, Xinyan Wu, Dong-Wen Lv, Kun Zhang, Srikanth S Manda, Akhilesh Pandey, and S Diane Hayward
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Epstein-Barr virus (EBV) is etiologically linked to infectious mononucleosis and several human cancers. EBV encodes a conserved protein kinase BGLF4 that plays a key role in the viral life cycle. To provide new insight into the host proteins regulated by BGLF4, we utilized stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomics to compare site-specific phosphorylation in BGLF4-expressing Akata B cells. Our analysis revealed BGLF4-mediated hyperphosphorylation of 3,046 unique sites corresponding to 1,328 proteins. Frequency analysis of these phosphosites revealed a proline-rich motif signature downstream of BGLF4, indicating a broader substrate recognition for BGLF4 than its cellular ortholog cyclin-dependent kinase 1 (CDK1). Further, motif analysis of the hyperphosphorylated sites revealed enrichment in ATM, ATR and Aurora kinase substrates while functional analyses revealed significant enrichment of pathways related to the DNA damage response (DDR), mitosis and cell cycle. Phosphorylation of proteins associated with the mitotic spindle assembly checkpoint (SAC) indicated checkpoint activation, an event that inactivates the anaphase promoting complex/cyclosome, APC/C. Furthermore, we demonstrated that BGLF4 binds to and directly phosphorylates the key cellular proteins PP1, MPS1 and CDC20 that lie upstream of SAC activation and APC/C inhibition. Consistent with APC/C inactivation, we found that BGLF4 stabilizes the expression of many known APC/C substrates. We also noted hyperphosphorylation of 22 proteins associated the nuclear pore complex, which may contribute to nuclear pore disassembly and SAC activation. A drug that inhibits mitotic checkpoint activation also suppressed the accumulation of extracellular EBV virus. Taken together, our data reveal that, in addition to the DDR, manipulation of mitotic kinase signaling and SAC activation are mechanisms associated with lytic EBV replication. All MS data have been deposited in the ProteomeXchange with identifier PXD002411 (http://proteomecentral.proteomexchange.org/dataset/PXD002411).
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- 2015
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27. Phosphorylation of the chromatin binding domain of KSHV LANA.
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Crystal Woodard, Meir Shamay, Gangling Liao, Jian Zhu, Ai Na Ng, Renfeng Li, Rob Newman, Hee-Sool Rho, Jianfei Hu, Jun Wan, Jiang Qian, Heng Zhu, and S Diane Hayward
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
The Kaposi sarcoma associated herpesvirus (KSHV) latency associated nuclear antigen (LANA) is expressed in all KSHV associated malignancies and is essential for maintenance of KSHV genomes in infected cells. To identify kinases that are potentially capable of modifying LANA, in vitro phosphorylation assays were performed using an Epstein Barr virus plus LANA protein microarray and 268 human kinases purified in active form from yeast. Interestingly, of the Epstein-Barr virus proteins on the array, the EBNA1 protein had the most similar kinase profile to LANA. We focused on nuclear kinases and on the N-terminus of LANA (amino acids 1-329) that contains the LANA chromatin binding domain. Sixty-three nuclear kinases phosphorylated the LANA N-terminus. Twenty-four nuclear kinases phosphorylated a peptide covering the LANA chromatin binding domain (amino acids 3-21). Alanine mutations of serine 10 and threonine 14 abolish or severely diminish chromatin and histone binding by LANA. However, conversion of these residues to the phosphomimetic glutamic acid restored histone binding suggesting that phosphorylation of serine 10 and threonine 14 may modulate LANA function. Serine 10 and threonine 14 were validated as substrates of casein kinase 1, PIM1, GSK-3 and RSK3 kinases. Short-term treatment of transfected cells with inhibitors of these kinases found that only RSK inhibition reduced LANA interaction with endogenous histone H2B. Extended treatment of PEL cell cultures with RSK inhibitor caused a decrease in LANA protein levels associated with p21 induction and a loss of PEL cell viability. The data indicate that RSK phosphorylation affects both LANA accumulation and function.
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- 2012
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28. Silk-engineered bioactive nanoparticles for targeted alleviation of acute inflammatory disease via macrophage reprogramming
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Renfeng Liu, Erkang Zhao, Yejing Wang, Hua Zuo, Lanlan Li, Qingyou Xia, and Huawei He
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Oxidative stress ,Anti-inflammation ,Inflammation-associated disease ,Silk ,Nanotherapy ,Biotechnology ,TP248.13-248.65 ,Medical technology ,R855-855.5 - Abstract
Abstract Significant progress has been made in the development of potential therapies for diseases associated with inflammation and oxidative stress. Nevertheless, the availability of effective clinical treatments remains limited. Herein, we introduce a novel silk-based bioactive material, TPSF, developed by sequentially conjugating Tempol and phenylboronic acid pinacol ester to silk fibroin. This innovative reactive oxygen species (ROS) scavenging material not only effectively eliminates free radicals and hydrogen peroxide but also readily self-assembles into nanoparticle forms (TPSN). In vitro experiments have demonstrated that TPSN exhibits significant anti-inflammatory activities and cytoprotective effects against ROS-mediated damage. Consistently, in murine models of acute lung and kidney injury, TPSN outperforms the small-molecule antioxidant NAC, exhibiting superior therapeutic efficacy. Mechanistically, TPSN has the capability to reprogram M1-like macrophages toward an M2-like state. Importantly, biocompatibility assays confirm that TPSN has good safety profiles. Consequently, TPSN, characterized by its favorable protective effects and excellent biocompatibility, exhibits considerable promise as a therapeutic intervention for inflammation-related diseases. This innovative strategy, which incorporates multifunctional antioxidant components into the silk fibroin matrix, effectively addresses oxidative stress and acute inflammation. Furthermore, it highlights the potential of modified silk fibroin materials in the management and mitigation of inflammation-led tissue damage.
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- 2025
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29. Difficulty encountered in the early radiological diagnosis of atypical pancreatic duct stones compared to the typical type in Chinese patients.
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Changlong HOU, Renfeng LI, Qianli CHEN, Liqing JIN, Bo HU, Xue MENG, and Jianhua ZHANG
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- 2024
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30. Chinese herbal compound prescription for Systemic lupus erythematosus: A protocol for systematic review and meta-analysis
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Xiusong Tang, Renfeng Li, Yulei Fu, Yuzhou Pang, Yunyan Zhang, Zhenfeng Chen, An Huang, Yehao Luo, and Donghan Xu
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medicine.medical_specialty ,education ,MEDLINE ,Traditional Chinese medicine ,Cochrane Library ,03 medical and health sciences ,Hemoglobins ,Leukocyte Count ,0302 clinical medicine ,systematic review ,systemic lupus erythematosus ,Study Protocol Systematic Review ,medicine ,Medicine and Health Sciences ,Humans ,Lupus Erythematosus, Systemic ,030212 general & internal medicine ,Chinese herbal compound prescription ,protocol ,Medical prescription ,Intensive care medicine ,Adverse effect ,skin and connective tissue diseases ,Randomized Controlled Trials as Topic ,Lupus erythematosus ,business.industry ,Remission Induction ,General Medicine ,medicine.disease ,meta-analysis ,Systematic review ,Research Design ,030220 oncology & carcinogenesis ,Meta-analysis ,business ,Drugs, Chinese Herbal ,Research Article - Abstract
Background: Systemic lupus erythematosus (SLE), known as lupus, is a chronic autoimmune disease and there is no cure for SLE. The western medication can improve syndromes to some extent; however, severe adverse drug reactions appear at the same time. Recently, it is confirmed that Chinese medicine also can have an excellent clinical efficacy on SLE. Methods and analysis: The following databases will be searched for relevant information before July 2020: PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure. Major results: levels of total remission rate, SLEDAI. Secondary results: The laboratory index about C3 levels, Hb levels, white blood cell levels, and adverse event. Data will be collected independently by 2 researchers, and the risk of bias in meta analysis will be evaluated according to “Cochrane Handbook for Systematic Reviews of Interventions.” All data analysis will be conducted using Review Manager V.5.3. and Stata V.12.0. Results: The curative effect and safety of Chinese herbal compound prescription treatment for SLE patients will be evaluated systematically. Conclusion: The systematic review of this study will summarize the currently published evidence of Chinese herbal compound prescription treatment for SLE to further guide its promotion and application. Ethics and dissemination: The private information from individuals will not be published. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences. Open Science Framework (OSF)registration number: https://osf.io/wvfrx/.
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- 2022
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31. Ferroptosis-related lncRNA NRAV affects the prognosis of hepatocellular carcinoma via miR-375-3P/SLC7A11 axis
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Ke Zong, Caifeng Lin, Kai Luo, Yilei Deng, Hongfei Wang, Jianfei Hu, Shi Chen, and Renfeng Li
- Abstract
Ferroptosis has important value in cancer treatment. It is significant to explore the new ferroptosis-related lncRNAs(FRLs) prediction model in Hepatocellular carcinoma (HCC) and the potential molecular mechanism of ferroptosis-related lncRNAs. We constructed a prognostic multi-lncRNA signature based on ferroptosis-related differentially expressed lncRNAs in HCC. qRT-PCR was applied to determine the expression of lncRNA in HCC cells. The biological roles of NRAV in vitro and in vivo were determined by performing a series of functional experiments. Further, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to confirm the interaction of NRAV with miR-375-3P. We identified 6 differently expressed lncRNAs associated with the prognosis of HCC. Kaplan-Meier analyses revealed the high-risk lncRNAs signature associated with poor prognosis of HCC. Moreover, the AUC of the lncRNAs signature showed the utility in predicting HCC prognosis. Further functional experiments show that the high expression of NRAV can strengthen the viciousness of HCC. Interestingly, we found that NRAV can enhance iron export and ferroptosis resistance. Further research showed NRAV via competitively binds to miR-375-3P and attenuates the inhibitory effect of miR-375-3P on SLC7A11, affecting the prognosis of patients with HCC. In conclusion, We developed a novel FRLs prognostic model with important predictive value for the prognosis of hepatocellular carcinoma. NRAV plays an important role in ferroptosis induction through the miR-375-3P/SLC7A11 axis.
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- 2022
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32. Combined Evaluation of mRNA and Protein Expression, Promoter Methylation, and Immune Infiltration of UBE2I in Pan-Digestive System Tumors
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Shuai Huang, Xiangkun Wang, Kai Luo, Xudong Zhang, Zhongyuan Liu, and Renfeng Li
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Pancreatic Neoplasms ,Aging ,Article Subject ,Colonic Neoplasms ,Ubiquitin-Conjugating Enzymes ,Humans ,Cell Biology ,General Medicine ,RNA, Messenger ,Adenocarcinoma ,Ribonucleoproteins, Small Nuclear ,Biochemistry ,Methylation - Abstract
Background. Digestive system tumors (DSTs) have high morbidity and mortality worldwide. This study explored the potential value of ubiquitin-conjugating enzyme E2 I (UBE2I) in pan-digestive system tumors (pan-DSTs). Methods. Differential expression, tumor stages, and survival outcomes of UBE2I in pan-DSTs were determined using the GEPIA database. The TIMER database was used to confirm the correlation of UBE2I expression with pan-DSTs and immune infiltrates. Differential analyses of UBE2I promoter methylation and protein levels were performed using the UALCAN database. The underlying mechanisms of UBE2I involvement in pan-DSTs were visualized using interaction networks. The diagnostic value of UBE2I in pan-DSTs was identified using the Oncomine database. Results. UBE2I was differentially and highly expressed in cholangiocarcinoma (CHOL), pancreatic adenocarcinoma (PAAD), colon adenocarcinoma (COAD), rectal adenocarcinoma (READ), liver hepatocellular carcinoma (LIHC), and stomach adenocarcinoma (STAD). According to survival analysis, upregulated UBE2I was associated with adverse overall and disease-free survival in PAAD and favorable overall survival in READ. UBE2I expression was partially linked to the purity of immune infiltration in COAD, LIHC, PAAD, READ, and STAD, as indicated by the immune infiltration analysis. Promoter methylation analysis showed differential and high methylation of UBE2I in PAAD as well as stratified analysis by gender, nodal metastasis, and race. Protein expression analysis in colon cancer revealed that UBE2I had differential and high expression in tumors as well as stratified analysis by gender, tumor histology, race, and tumor stage. Mechanism explorations demonstrated that in COAD and PAAD, UBE2I was involved in spliceosomal snRNP complex, Notch signaling pathway, etc. Diagnostic analysis indicated that UBE2I had consistent diagnostic value for COAD and PAAD. Conclusions. Upregulated UBE2I may be a diagnostic and surveillance predictive signature for PAAD and COAD. The potential significance of immune infiltrates and promoter methylation in PAAD and COAD needs further exploration.
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- 2022
33. Calreticulin: a potential diagnostic and therapeutic biomarker in gallbladder cancer
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Renfeng Li, Wenlong Zhai, Jianwen Ye, Long Yu, Lei Qi, Zhicheng Du, Kunlun Chen, and Ruo Feng
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Male ,Aging ,Antimetabolites, Antineoplastic ,genetic structures ,Mice, Nude ,Deoxycytidine ,gallbladder cancer ,calreticulin ,Random Allocation ,Cell Line, Tumor ,Biomarkers, Tumor ,Cholecystitis ,Medicine ,Animals ,Humans ,cardiovascular diseases ,Molecular Targeted Therapy ,Gallbladder cancer ,PI3K/AKT/mTOR pathway ,Gene knockdown ,biology ,Oncogene ,business.industry ,Cell growth ,Cancer ,Cell Biology ,Oncogenes ,Cell cycle ,Middle Aged ,medicine.disease ,equipment and supplies ,Prognosis ,Xenograft Model Antitumor Assays ,Gemcitabine ,PI3K/Akt pathway ,Cancer research ,biology.protein ,cardiovascular system ,biomarker ,Female ,Gallbladder Neoplasms ,business ,Calreticulin ,circulatory and respiratory physiology ,Research Paper - Abstract
Recent studies suggested that calreticulin (CRT) has an important role in the progression of various types of cancer. Our previous study suggested that CRT was upregulated and acted as an oncogene in hepatocellular carcinoma. However, the role of CRT in gallbladder cancer (GBC) remains unclear. The expression level of CRT was upregulated in GBC tissues in comparison with adjacent non-tumor tissues and chronic cholecystitis tissues. Moreover, CRT expression was found to be correlated with the tumor size. Knockdown of CRT inhibited cell proliferation, induced apoptosis, arrested cell cycle and resulted in decreased resistance to gemcitabine, which was mediated by the inactivation of the PI3K/Akt pathway. Collectively, the present results suggested a potential role of CRT in GBC progression and provided novel insights into the mechanism underlying the CRT-mediated chemosensitivity in GBC cells.
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- 2021
34. NRAV, a newly identified Ferroptosis-related lncRNAs, affects the prognosis of hepatocellular carcinoma through the miR-375- 3P/SLC7A11 axis
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Ke Zong, jianfei hu, Kai Luo, Yilei Deng, Hongfei Wang, Shi Chen, and Renfeng Li
- Abstract
Background: Ferroptosis has important value in cancer treatment. It is significant to explore the new Ferroptosis-related lncRNA prediction model in Hepatocellular carcinoma (HCC) and the potential molecular mechanism.Methods: We constructed a prognostic multilncRNA signature based on ferroptosis-related differentially expressed lncRNAs in HCC. qRT-PCR was applied to determine the expression of lncRNA in HCC cells and tissues. The biological roles of NRAV in vitro and in vivo were determined by performing a series of functional experiments. Further, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to confirm the interaction of NRAV with miR-375-3P.Results: We identified 19 differently expressed lncRNAs associated with the prognosis of HCC. Kaplan-Meier analyses revealed the high-risk lncRNAs signature associated with poor prognosis of HCC. Moreover, the AUC of the lncRNAs signature was 0.803, underscoring their utility in predicting HCC prognosis. Indeed, our risk assessment model was superior to standard clinicopathological features in predicting HCC prognosis. Further functional experiments show that the high expression of NRAV can strengthen the viciousness of HCC. NRAV via miR-375-3P/SLC7A11 axis enhances iron export and ferroptosis resistance, affecting the prognosis of patients with HCC.Conclusion: A novel ferroptosis-related lncRNAs signature impacts the prognosis of HCC.NRAV may play a role in induced ferroptosis, which can be considered a potential therapeutic target in HCC.
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- 2022
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35. Dual stage MRI image restoration based on blind spot denoising and hybrid attention
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Renfeng Liu, Songyan Xiao, Tianwei Liu, Fei Jiang, Cao Yuan, and Jianfeng Chen
- Subjects
Deep learning ,Medical imaging ,Blind spot denoising ,Attention ,GANs ,Medical technology ,R855-855.5 - Abstract
Abstract Background Magnetic Resonance Imaging (MRI) is extensively utilized in clinical diagnostics and medical research, yet the imaging process is often compromised by noise interference. This noise arises from various sources, leading to a reduction in image quality and subsequently hindering the accurate interpretation of image details by clinicians. Traditional denoising methods typically assume that noise follows a Gaussian distribution, thereby neglecting the more complex noise types present in MRI images, such as Rician noise. As a result, denoising remains a challenging and practical task. Method The main research work of this paper focuses on modifying mask information based on a global mask mapper. The mask mapper samples all blind spot pixels on the denoised image and maps them to the same channel. By incorporating perceptual loss, it utilizes all available information to improve performance while avoiding identity mapping. During the denoising process, the model may mistakenly remove some useful information as noise, resulting in a loss of detail in the denoised image. To address this issue, we train a generative adversarial network (GAN) with adaptive hybrid attention to restore the detailed information in the denoised MRI images. Result The two-stage model NRAE shows an improvement of nearly 1.4 dB in PSNR and approximately 0.1 in SSIM on clinical datasets compared to other classic models. Specifically, compared to the baseline model, PSNR is increased by about 0.6 dB, and SSIM is only 0.015 lower. From a visual perspective, NRAE more effectively restores the details in the images, resulting in richer and clearer representation of image details. Conclusion We have developed a deep learning-based two-stage model to address noise issues in medical MRI images. This method not only successfully reduces noise signals but also effectively restores anatomical details. The current results indicate that this is a promising approach. In future work, we plan to replace the current denoising network with more advanced models to further enhance performance.
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- 2024
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36. Microenvironment-responsive metal-phenolic network release platform with ROS scavenging, anti-pyroptosis, and ECM regeneration for intervertebral disc degeneration
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Hao Zhou, Jinpeng He, Renfeng Liu, Jun Cheng, Yuhao Yuan, Wanpu Mao, Jun Zhou, Honghui He, Qianqi Liu, Wei Tan, Cijun Shuai, and Youwen Deng
- Subjects
Intervertebral disc degeneration ,Metal-phenolic network ,Pyroptosis ,IL-17/ERK signaling pathway ,Reactive oxygen species ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biology (General) ,QH301-705.5 - Abstract
Intervertebral disc degeneration (IVDD) can be caused by aging, injury, and genetic factors. The pathological changes associated with IVDD include the excessive accumulation of reactive oxygen species (ROS), cellular pyroptosis, and extracellular matrix (ECM) degradation. There are currently no approved specific molecular therapies for IVDD. In this study, we developed a multifunctional and microenvironment-responsive metal-phenolic network release platform, termed TMP@Alg-PBA/PVA, which could treat (IL-1β)-induced IVDD. The metal-phenolic network (TA-Mn-PVP, TMP) released from this platform targeted mitochondria to efficiently scavenge ROS and reduce ECM degradation. Pyroptosis was suppressed through the inhibition of the IL-17/ERK signaling pathway. These findings demonstrate the versatility of the platform. And in a rat model of IVDD, TMP@Alg-PBA/PVA exhibited excellent therapeutic effects by reducing the progression of the disease. TMP@Alg-PBA/PVA, therefore, presents clinical potential for the treatment of IVDD.
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- 2024
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37. Enhanced electrocatalytic biomass oxidation at low voltage by Ni2+-O-Pd interfaces
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An Pei, Peng Wang, Shiyi Zhang, Qinghua Zhang, Xiaoyi Jiang, Zhaoxi Chen, Weiwei Zhou, Qizhen Qin, Renfeng Liu, Ruian Du, Zhengjian Li, Yongcai Qiu, Keyou Yan, Lin Gu, Jinyu Ye, Geoffrey I. N. Waterhouse, Wei-Hsiang Huang, Chi-Liang Chen, Yun Zhao, and Guangxu Chen
- Subjects
Science - Abstract
Abstract Challenges in direct catalytic oxidation of biomass-derived aldehyde and alcohol into acid with high activity and selectivity hinder the widespread biomass application. Herein, we demonstrate that a Pd/Ni(OH)2 catalyst with abundant Ni2+-O-Pd interfaces allows electrooxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid with a selectivity near 100 % and 2, 5-furandicarboxylic acid yield of 97.3% at 0.6 volts (versus a reversible hydrogen electrode) in 1 M KOH electrolyte under ambient conditions. The rate-determining step of the intermediate oxidation of 5-hydroxymethyl-2-furancarboxylic acid is promoted by the increased OH species and low C–H activation energy barrier at Ni2+-O-Pd interfaces. Further, the Ni2+-O-Pd interfaces prevent the agglomeration of Pd nanoparticles during the reaction, greatly improving the stability of the catalyst. In this work, Pd/Ni(OH)2 catalyst can achieve 100% 5-hydroxymethylfurfural conversion and >90% 2, 5-furandicarboxylic acid selectivity in a flow-cell and work stably over 200 h under a fixed cell voltage of 0.85 V.
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- 2024
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38. Morphological and Immunohistochemical Identification of Villous M Cells in the Small Intestine of Newborn Piglets/Identificacion Morfologica e Inmunohistoquimica de los Epiteliocitos Microplegados de las Vellosidades en el Intestino Delgado de Lechones Recien Nacidos
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Renfeng, Li, Xiangqin, Tian, Songlin, Qiao, Yanyan, Yang, Enmin, Zhou, and Gaiping, Zhang
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- 2015
39. Alleviation of infectious-bursal-disease-virus-induced bursal injury by betaine is associated with DNA methylation in IL-6 and interferon regulatory factor 7 promoter
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Shouyang Du, Yanhong Zhang, Feng Guo, Yan Yu, Renfeng Li, Zhiyong Xu, Jinyou Ma, Changbo Ou, and Qiuxia Wang
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animal structures ,Interferon Regulatory Factor-7 ,Biology ,Antiviral Agents ,Infectious bursal disease virus ,Virus ,Infectious bursal disease ,Avian Proteins ,Random Allocation ,03 medical and health sciences ,chemistry.chemical_compound ,Betaine ,medicine ,Animals ,Poultry Diseases ,030304 developmental biology ,0303 health sciences ,Interleukin-6 ,0402 animal and dairy science ,Promoter ,04 agricultural and veterinary sciences ,General Medicine ,Methylation ,DNA Methylation ,Birnaviridae Infections ,medicine.disease ,040201 dairy & animal science ,Virology ,chemistry ,DNA methylation ,IRF7 ,Animal Science and Zoology ,Interferon regulatory factors - Abstract
Infectious bursal disease virus (IBDV) often infects young chickens and causes severe immunosuppression and inflammatory injury. Betaine is an antiviral and anti-inflammatory ingredient that may exert functions through epigenetic regulation. However, the effects of betaine on an IBDV-induced bursal injury and their underlying mechanisms have not been investigated. In this study, betaine was supplemented to the drinking water of newly hatched commercial broilers for 3 wk. Afterward, the chickens were infected with the IBDV. After 5 D of infection, the bursal lesions were examined. The mRNA expression levels of IBDV VP2 gene, pro-inflammatory cytokines, and interferons were detected. Furthermore, the 5-methylcytosine level of the CpG island in the promoter region of IL-6 and interferon regulatory factor 7 (IRF7) were determined. The IBDV induced the depletion of lymphocytes and inflammation in the bursal follicles. IBDV infection considerably elevated the mRNA levels of VP2, IL-6, types I (IFNα and IFNβ) and II (IFNγ) interferons, and IRF7. The CpG island methylation in the promoter regions of IL-6 and IRF7 were substantially decreased after IBDV infection. Betaine administration attenuated the IBDV-induced bursal lesions. Meanwhile, the IBDV-induced mRNA expression levels of IL-6, IFNβ, and IRF7 were suppressed by betaine consumption. Furthermore, the hypomethylation effects of IBDV infection to the promoter regions of IL-6 and IRF7 genes were eliminated and relieved by betaine administration. Our results indicated that the IBDV-induced expression levels of IL-6 and IRF7 genes are associated with the suppression of methylation in the promoter region. Betaine administration through drinking water may alleviate the IBDV-induced bursal injury via epigenetic regulation.
- Published
- 2019
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40. CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle
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Laurence H. Pearl, Molly L. Bristol, Iain M. Morgan, Dipon Das, Brian O. Smith, Christian T. Fontan, Matthew Day, Sarah H Glass, Apurva T. Prabhakar, Andreas Wieland, Anthony W Oliver, John W. Burgner, Raymonde Otoa, Claire D. James, Mary Donaldson, Renfeng Li, and Xu Wang
- Subjects
Keratinocytes ,cervical cancer ,viruses ,CK2 ,Mitosis ,Biology ,medicine.disease_cause ,Virus Replication ,Microbiology ,papillomavirus ,Serine ,Viral life cycle ,E2 ,Transcription (biology) ,Virology ,medicine ,life cycle ,Humans ,Phosphorylation ,human papillomavirus ,Casein Kinase II ,Mutation ,Human papillomavirus 16 ,Life Cycle Stages ,Nuclear Proteins ,TopBP1 ,Oncogene Proteins, Viral ,assay ,QR1-502 ,Chromatin ,Cell biology ,DNA-Binding Proteins ,Viral replication ,Host-Pathogen Interactions ,BRD4 ,head and neck cancer ,Carrier Proteins ,Research Article - Abstract
During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitro and in vivo. This complex results in stabilization of E2 during mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23 in vivo and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, hindering immortalization and disrupting the viral life cycle, demonstrating a critical function for this residue.
- Published
- 2021
41. Magnesium malate-modified calcium phosphate bone cement promotes the repair of vertebral bone defects in minipigs via regulating CGRP
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Hailiang Xu, Fang Tian, Youjun Liu, Renfeng Liu, Hui Li, Xinlin Gao, Cheng Ju, Botao Lu, Weidong Wu, Zhiyuan Wang, Lei Zhu, Dingjun Hao, and Shuaijun Jia
- Subjects
Calcium phosphate cement ,Magnesium malate ,Bone defect ,Calcitonin gene-related peptide ,Prostaglandin E2 ,Osteogenesis ,Biotechnology ,TP248.13-248.65 ,Medical technology ,R855-855.5 - Abstract
Abstract Active artificial bone substitutes are crucial in bone repair and reconstruction. Calcium phosphate bone cement (CPC) is known for its biocompatibility, degradability, and ability to fill various shaped bone defects. However, its low osteoinductive capacity limits bone regeneration applications. Effectively integrating osteoinductive magnesium ions with CPC remains a challenge. Herein, we developed magnesium malate-modified CPC (MCPC). Incorporating 5% magnesium malate significantly enhances the compressive strength of CPC to (6.18 ± 0.49) MPa, reduces setting time and improves disintegration resistance. In vitro, MCPC steadily releases magnesium ions, promoting the proliferation of MC3T3-E1 cells without causing significant apoptosis, proving its biocompatibility. Molecularly, magnesium malate prompts macrophages to release prostaglandin E2 (PGE2) and synergistically stimulates dorsal root ganglion (DRG) neurons to synthesize and release calcitonin gene-related peptide (CGRP). The CGRP released by DRG neurons enhances the expression of the key osteogenic transcription factor Runt-related transcription factor-2 (RUNX2) in MC3T3-E1 cells, promoting osteogenesis. In vivo experiments using minipig vertebral bone defect model showed MCPC significantly increases the bone volume fraction, bone density, new bone formation, and proportion of mature bone in the defect area compared to CPC. Additionally, MCPC group exhibited significantly higher levels of osteogenesis and angiogenesis markers compared to CPC group, with no inflammation or necrosis observed in the hearts, livers, or kidneys, indicating its good biocompatibility. In conclusion, MCPC participates in the repair of bone defects in the complex post-fracture microenvironment through interactions among macrophages, DRG neurons, and osteoblasts. This demonstrates its significant potential for clinical application in bone defect repair.
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- 2024
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42. Biomechanical response of decompression alone in lower grade lumbar degenerative spondylolisthesis--A finite element analysis
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Renfeng Liu, Tao He, Xin Wu, Wei Tan, Zuyun Yan, and Youwen Deng
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Degenerative lumbar spondylolisthesis ,Laminectomy ,Decompression alone ,Biomechanics ,Finite element analysis ,Orthopedic surgery ,RD701-811 ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Previous studies have demonstrated the clinical efficacy of decompression alone in lower-grade spondylolisthesis. A higher rate of surgical revision and a lower rate of back pain relief was also observed. However, there is a lack of relevant biomechanical evidence after decompression alone for lower-grade spondylolisthesis. Purpose Evaluating the biomechanical characteristics of total laminectomy, hemilaminectomy, and facetectomy for lower-grade spondylolisthesis by analyzing the range of motion (ROM), intradiscal pressure (IDP), annulus fibrosus stress (AFS), facet joints contact force (FJCF), and isthmus stress (IS). Methods Firstly, we utilized finite element tools to develop a normal lumbar model and subsequently constructed a spondylolisthesis model based on the normal model. We then performed total laminectomy, hemilaminectomy, and one-third facetectomy in the normal model and spondylolisthesis model, respectively. Finally, we analyzed parameters, such as ROM, IDP, AFS, FJCF, and IS, for all the models under the same concentrate force and moment. Results The intact spondylolisthesis model showed a significant increase in the relative parameters, including ROM, AFS, FJCF, and IS, compared to the intact normal lumbar model. Hemilaminectomy and one-third facetectomy in both spondylolisthesis and normal lumbar models did not result in an obvious change in ROM, IDP, AFS, FJCF, and IS compared to the pre-operative state. Moreover, there was no significant difference in the degree of parameter changes between the spondylolisthesis and normal lumbar models after undergoing the same surgical procedures. However, total laminectomy significantly increased ROM, AFS, and IS and decreased the FJCF in both normal lumbar models and spondylolisthesis models. Conclusion Hemilaminectomy and one-third facetectomy did not have a significant impact on the segment stability of lower-grade spondylolisthesis; however, patients with LDS undergoing hemilaminectomy and one-third facetectomy may experience higher isthmus stress on the surgical side during rotation. In addition, total laminectomy changes the biomechanics in both normal lumbar models and spondylolisthesis models.
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- 2024
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43. Clinical characteristics analysis of pediatric spinal cord injury without radiological abnormality in China: a retrospective study
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Renfeng Liu, Qizhi Fan, Jingpeng He, Xin Wu, Wei Tan, Zuyun Yan, Weiguo Wang, Zhiyue Li, and You-Wen Deng
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SCIWORA ,Chinese children ,Sports-related ,Dancing ,Backbend ,Pediatric ,Pediatrics ,RJ1-570 - Abstract
Abstract Purpose This study aims to analyze the clinical characteristics of Chinese children with spinal cord injury (SCI) without radiographic abnormality (SCIWORA) and explore their contributing factors and mechanisms of occurrence. Methods A retrospective analysis was conducted on the clinical data of pediatric patients diagnosed with SCIWORA from January 2005 to May 2020. Epidemiological, etiological, mechanistic, therapeutic, and outcome aspects were analyzed. Results A total of 47 patients with SCIWORA were included in this study, comprising 16 males and 31 females. The age range was 4 to 12 years, with an average age of 7.49 ± 2.04 years, and 70% of the patients were below eight. Sports-related injuries constituted 66%, with 70% attributed to dance backbend practice. Thoracic segment injuries accounted for 77%. In the American Spinal Injury Association (ASIA) classification, the combined proportion of A and B grades accounted for 88%. Conservative treatment was chosen by 98% of the patients, with muscle atrophy, spinal scoliosis, hip joint abnormalities, and urinary system infections being the most common complications. Conclusion SCIWORA in Chinese children is more prevalent in those under eight years old, with a higher incidence in females than males. Thoracic spinal cord injuries are predominant, dance backbend as a primary contributing factor, and the social environment of “neijuan” is a critical potential inducing factor. Furthermore, the initial severity of the injury plays a decisive role in determining the prognosis of SCIWORA.
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- 2024
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44. PIAS1 Potentiates the Anti-viral Activity of SAMHD1 through SUMOylation
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Farjana Saiada, Kun Zhang, and Renfeng Li
- Abstract
Background: Sterile alpha motif and HD domain 1 (SAMHD1) is a host restriction factor that suppresses the infection of a variety of RNA and DNA viruses, including herpesviruses. The anti-viral activity of SAMHD1 is finely tuned by post-translational modifications, including phosphorylation, acetylation and ubiquitination. Our recent studies also demonstrated that the E3 SUMO ligase PIAS1 functions as an Epstein-Barr virus (EBV) restriction factor. However, whether SAMHD1 is regulated by PIAS1 to restrict viral infection remains unknown.Results: In this study, we showed that PIAS1 interacts with SAMHD1 and promotes its SUMOylation. We identified three lysine residues (K469, K595 and K622) located on the surface of SAMHD1 as the major SUMOylation sites. We demonstrated that phosphorylation of SAMHD1 slightly promotes its SUMOylation by PIAS1 and SUMOylated SAMHD1 can still be phosphorylated by viral protein kinases. We further demonstrated that SUMOylation-deficient SAMHD1 loses its anti-EBV activity. Conclusion: Our study reveals that PIAS1-mediated SUMOylation of SAMHD1 enhances its anti-viral activity.
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- 2021
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45. PIAS1 potentiates the anti-EBV activity of SAMHD1 through SUMOylation
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Kun Zhang, Farjana Saiada, and Renfeng Li
- Subjects
QH301-705.5 ,Viral protein ,Deoxynucleotide triphosphohydrolase ,Lysine ,SUMO protein ,Cytomegalovirus ,QD415-436 ,PIAS1 ,medicine.disease_cause ,Biochemistry ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Ubiquitin ,medicine ,Epstein-Barr virus ,Biology (General) ,Phosphorylation ,030304 developmental biology ,0303 health sciences ,biology ,Chemistry ,Research ,030302 biochemistry & molecular biology ,Restriction factor ,Herpesvirus ,SAMHD1 ,SUMOylation ,Cell biology ,Lytic cycle ,biology.protein ,HD domain ,Sterile alpha motif ,TP248.13-248.65 ,Biotechnology - Abstract
Background Sterile alpha motif and HD domain 1 (SAMHD1) is a deoxynucleotide triphosphohydrolase (dNTPase) that restricts the infection of a variety of RNA and DNA viruses, including herpesviruses. The anti-viral function of SAMHD1 is associated with its dNTPase activity, which is regulated by several post-translational modifications, including phosphorylation, acetylation and ubiquitination. Our recent studies also demonstrated that the E3 SUMO ligase PIAS1 functions as an Epstein-Barr virus (EBV) restriction factor. However, whether SAMHD1 is regulated by PIAS1 to restrict EBV replication remains unknown. Results In this study, we showed that PIAS1 interacts with SAMHD1 and promotes its SUMOylation. We identified three lysine residues (K469, K595 and K622) located on the surface of SAMHD1 as the major SUMOylation sites. We demonstrated that phosphorylated SAMHD1 can be SUMOylated by PIAS1 and SUMOylated SAMHD1 can also be phosphorylated by viral protein kinases. We showed that SUMOylation-deficient SAMHD1 loses its anti-EBV activity. Furthermore, we demonstrated that SAMHD1 is associated with EBV genome in a PIAS1-dependent manner. Conclusion Our study reveals that PIAS1 synergizes with SAMHD1 to inhibit EBV lytic replication through protein–protein interaction and SUMOylation.
- Published
- 2021
46. CK2 phosphorylation of human papillomavirus 16 E2 on serine 23 promotes interaction with TopBP1 and is critical for E2 plasmid retention function
- Author
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Apurva T. Prabhakar, Claire D. James, Dipon Das, Raymonde Otoa, Matthew Day, John Burgner, Christian T. Fontan, Xu Wang, Andreas Wieland, Mary M. Donaldson, Molly L. Bristol, Renfeng Li, Anthony W. Oliver, Laurence H. Pearl, Brian O. Smith, and Iain M. Morgan
- Subjects
Serine ,Mutation ,Plasmid ,Cell division ,Chemistry ,Transcription (biology) ,medicine ,Phosphorylation ,medicine.disease_cause ,Mitosis ,Chromatin ,Cell biology - Abstract
During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here, we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1in vitroandin vivo, and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A activates and represses transcription identically to E2-WT (wild-type), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin when compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis when compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. We next tested whether this difference in E2-S23A levels during mitosis disrupts E2 plasmid retention function. We developed a novel plasmid retention assay and demonstrate that E2-S23A is deficient in plasmid retention when compared with E2-WT. siRNA targeted knockdown of TopBP1 abrogates E2-WT plasmid retention function. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1, which is critical for E2 plasmid retention function and in HPV16 immortalization of keratinocytes.ImportanceHuman papillomaviruses are causative agents in around 5% of all cancers, with no specific anti-viral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex formation with the cellular protein TopBP1in vitroandin vivo. This complex results in stabilization of E2 during mitosis and mediates plasmid retention by E2. This function promotes the partitioning of viral genomes into the nuclei of daughter cells following mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23in vivo, and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, demonstrating a critical function for this residue. Together, our results suggest that CK2 inhibitors may disrupt the E2-TopBP1 dependent HPV16 life cycle and potentially kill HPV16 positive cancers, which lays a molecular foundation to develop novel therapeutic approaches for combating HPV16 disease.
- Published
- 2021
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47. Caspases switch off m6A RNA modification pathway to reactivate a ubiquitous human tumor virus
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Kun Zhang, Yucheng Zhang, Yunash Maharjan, Febri G Sugiokto, Jun Wan, and Renfeng Li
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Messenger RNA ,Viral life cycle ,biology ,biology.protein ,RNA ,Methylation ,Cell cycle ,Virus ,Caspase ,Oncovirus ,Cell biology - Abstract
The methylation of RNA at the N6 position of adenosine (m6A) orchestrates multiple biological processes to control development, differentiation, and cell cycle, as well as various aspects of the virus life cycle. How the m6A RNA modification pathway is regulated to finely tune these processes remains poorly understood. Here, we discovered the m6A reader YTHDF2 as a caspase substrate via proteome-wide prediction, followed by in vitro and in vivo validations. We further demonstrated that cleavage-resistant YTHDF2 blocks, while cleavage-mimicking YTHDF2 fragments promote, the replication of a common human oncogenic virus, Epstein-Barr virus (EBV). Intriguingly, our study revealed a feedback regulation between YTHDF2 and caspase-8 via m6A modification of CASP8 mRNA and YTHDF2 cleavage during EBV replication. Further, we discovered that caspases cleave multiple components within the m6A RNA modification pathway to benefit EBV replication. Together, our study establishes that caspase disarming of the m6A RNA modification machinery fosters EBV reactivation.TeaserCellular m6A RNA modification machinery is cleaved by caspases to foster the reproduction of a common human tumor virus
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- 2020
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48. Cover Image, Volume 92, Number 9, September 2020
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Yunfeng Zheng, Renfeng Li, and Shunai Liu
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Infectious Diseases ,Virology - Published
- 2020
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49. Lenvatinib induces anticancer activity in gallbladder cancer by targeting AKT
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Ruo Feng, Jianwen Ye, Wenlong Zhai, Renfeng Li, Wentao Liu, Ke Zong, Jialu Liang, and Lei Qi
- Subjects
0301 basic medicine ,Phosphoinositide 3-kinase ,biology ,Cell growth ,Cell ,Cell cycle ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Cyclin D1 ,medicine.anatomical_structure ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,medicine ,biology.protein ,Lenvatinib ,Protein kinase B ,PI3K/AKT/mTOR pathway - Abstract
Gallbladder cancer (GBC) is characterized by poor prognosis, early metastasis, and high recurrence rates, which seriously threaten human health. The effect of lenvatinib, a widely used drug in anti-hepatocellular carcinoma in China, on GBC progress, as well as its underlying molecular mechanism, remains unclear. Therefore, the present study investigated the effect of lenvatinib on human GBC GBC-SD and NOZ cells and its underlying mechanisms. A series of experiments, including cell proliferation, clone formation, wound healing, and cell migration and invasion assays, as well as flow cytometry, were performed to investigate the anticancer effect of lenvatinib on GBC. Western blotting was used to detect alterations in protein expression of CKD2, CKD4, cyclin D1, caspase-9, matrix metalloproteinase (MMP)-2, cell migration-inducing protein (CEMIP) and phospho-AKT (p-AKT). In addition, the chemosensitivity of lenvatinib-treated GBC cells to gemcitabine (GEM) and whether the activation of phosphoinositide 3 kinase (PI3K)/AKT contributed to the chemoresistance were determined. Finally, the anticancer effect of lenvatinib in vivo was detected using a xenograft mouse model. These data showed that treatment with lenvatinib inhibited cell proliferation, colony formation ability, migration, induced apoptosis, regulated cell cycle and resulted in decreased resistance to GEM. Treatment with lenvatinib decreased the expression of MMP-2, CEMIP, CDK2, CDK4 and cyclin D1, and increased the expression of cleaved caspase-9, which was mediated by the inactivation of the PI3K/AKT pathway in vitro. In addition, lenvatinib inhibited autophagy in GBC-SD and NOZ cells. Besides, Lenvatinib suppressed GBC cell growth in vivo by targeting p-AKT. In combination, the present data indicated that lenvatinib plays a potential anticancer role in GBC by downregulating the expression of p-AKT.
- Published
- 2020
50. Immunoregulation with mTOR inhibitors to prevent COVID‐19 severity: A novel intervention strategy beyond vaccines and specific antiviral medicines
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Shunai Liu, Renfeng Li, and Yunfeng Zheng
- Subjects
mTOR inhibitors ,medicine.medical_treatment ,coronavirus ,Reviews ,Review ,Cross Reactions ,medicine.disease_cause ,Antibodies, Viral ,Virus ,Immunomodulation ,03 medical and health sciences ,0302 clinical medicine ,cross‐reactive antibody ,Immunity ,Virology ,medicine ,Humans ,Antibody-dependent enhancement ,030212 general & internal medicine ,PI3K/AKT/mTOR pathway ,Coronavirus ,B-Lymphocytes ,business.industry ,rapamycin ,Mortality rate ,TOR Serine-Threonine Kinases ,medicine.disease ,immunity ,Antibody-Dependent Enhancement ,COVID-19 Drug Treatment ,Clinical trial ,Cytokine release syndrome ,Cytokine ,Infectious Diseases ,Immunology ,antibody‐dependent enhancement ,cytokine storm ,030211 gastroenterology & hepatology ,Cytokine storm ,business ,Cytokine Release Syndrome ,ADE - Abstract
Coronavirus disease 2019 (COVID‐19) has become a major global public health concern. The mortality rate for critically ill patients is up to 60%, and, thus, reducing the disease severity and case mortality is a top priority. Currently, cytokine storms are considered as the major cause of critical illness and death due to COVID‐19. After a systematical review of the literature, we propose that cross‐reactive antibodies associated with antibody‐dependent enhancement (ADE) may actually be the cause of cytokine storms. It would be more difficult to develop vaccines for highly pathogenic human coronaviruses (CoVs) if ADE characteristics are taken into consideration. Therefore, it is urgent to find an effective way to prevent the occurrence of severe illness as severe acute respiratory syndrome CoV‐2 specific drugs or vaccines are still in development. If the activation of memory B cells can be selectively inhibited in high‐risk patients at an early stage of COVID‐19 to reduce the production of cross‐reactive antibodies against the virus, we speculate that ADE can be circumvented and severe symptoms can be prevented. The mammalian target of rapamycin (mTOR) inhibitors satisfy such needs and it is recommended to conduct clinical trials for mTOR inhibitors in preventing the severity of COVID‐19., Highlights Cytokine storms are the major cause of critical illness and death due to COVID‐19. Antibody‐dependent enhancement (ADE) may be the major cause of cytokine storms. Selective inhibition of memory B cell activation by mTOR inhibitors could prevent ADE and reduce COVID‐19 severity.
- Published
- 2020
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