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Osteoporosis (OP) predominantly affects elderly individuals. Stem cells show potential for treating OP. However, animal models with normal immune function can eliminate implanted human cells. This study utilized naturally aging NOD/SCID mice, which exhibit immunodeficiency, to create a human osteoporosis model. This approach helps to minimize the premature immune clearance of transplanted allogeneic or xenogeneic cells in preclinical studies, allowing for a more accurate replication of the clinical pharmacological and pharmacokinetic processes involved in stem cell interventions for osteoporosis. NOD/SCID mice were fed until 12, 32, and 43 weeks of age, respectively, and then euthanized. We harvested lumbar vertebra for Micro-Computed Tomography (Micro-CT) scanning and pathological examination. Additionally, we performed biomechanical testing of lumbar vertebra to assess the severity of osteoporosis. We utilized real-time RT-PCR to assess gene expression changes associated with bone metabolism, aging, inflammation, oxidative stress, and the Tgf-β1/Smad3 signaling pathway. In addition, the protein expression levels of P16, Tgf-β1 and Smad3 were detected using Western Blotting (WB). In comparison to 12-week-old mice, the 32-week-old and 43-week-old mice displayed significantly sparser and fractured trabeculae in their lumbar vertebra, lower bone mineral density (BMD), and changes in bone microstructural parameters (∗∗P < 0.01, ∗∗∗P < 0.001). Additionally, compared to 12-week-old mice, the 32-week-old and 43-week-old mice exhibited decreased expression of osteogenic genes (Alp, Opg, Sp7, Col1a1), increased expression of osteoclastic gene (Rankl), the number of TRAP-positive osteoclasts significantly increased in 32-week-old and 43-week-old mice compared to 12-week-old mice. The expression of genes related to aging and inflammatory (P16, Il-1β, Tnf-α) increases with advancing age (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001). The expression of oxidative stress-related genes (Sod1, Sod2, Foxo3, Nrf2), as well as Tgf-β1 and Smad3 decreased with age (∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001). As age increases, the levels of P16 protein increase, Tgf-β1 and Smad3 proteins decrease. Our study successfully replicated osteoporosis models in NOD/SCID mice at both 32 and 43 weeks, with the latter exhibiting more severe osteoporosis. This condition seems to be driven by factors such as aging, inflammation, oxidative stress, and the Tgf-β1/Smad3 signaling pathway., Competing Interests: Declaration of competing interest Zhaoxia Ma, Lihua Qiu, Jinyan Li, Zhen Wu, Shu Liang, Yunhui Zhao, Jinmei Yang, Min Hu and Yanjiao Li declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Lung cancer is the leading cause of cancer death worldwide. 85 % of lung cancers are categorized by their histological types as a non-small cell lung cancer (NSCLC) subtype. While the MED23 subunit of the mediator complex has been implicated in lung cancer development, the precise underlying mechanism remains unclear. Our research indicates that elevated MED23 expression is linked to reduced overall survival rates in NSCLC. Depletion of MED23 triggers premature senescence in NSCLC cells. Furthermore, through co-IP and mass spectrometry analyses, we have identified BCLAF1 as a binding partner of MED23, with subsequent confirmation via PLA assays. Subsequently, NUPR1, a transcriptional cofactor known to induce premature senescence in lung cancer cells by disrupting autophagic processes, was validated as a downstream target of the MED23/BCLAF1 complex through RNA-seq and ChIP assays. Thus, the interaction between MED23 and BCLAF1 regulates NUPR1 expression, impacting autophagic flux and leading to premature senescence in NSCLC cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Keloids represent a prevalent dermal fibroproliferative disorder. They only affect humans and exhibit several tumor characteristics, such as excessive extracellular matrix (ECM) deposition, which usually occurs after skin injury. Kreotoxin type A (KTA) can inhibit the release of acetylcholine, and thereby inhibit the proliferation of keloid fibroblasts and reducing the formation of scars. Thus, KTA could be used as a therapeutic agent for keloids. However, the mechanisms of action of KTA in keloid treatment remain unclear. In this study, we aimed to explore the underlying mechanisms of action of KTA in human keloid treatment using human tissue and a cell-based model. Integrative microarray analysis revealed that hypoxia-inducible factor 1-alpha (HIF-1α) expression was frequently upregulated in hypertrophic scar and keloid tissues, whereas it was downregulated in the KTA-treated samples. Furthermore, KTA addition to keloid-derived fibroblasts (KDFs) reduced the growth rate and viability, induced apoptosis, and decreased inflammation and oxidative stress in KDFs. However, overexpression of HIF-1α restored cell number and survival, decreased apoptosis, and promoted inflammation and oxidative stress in KTA-treated KDFs. Furthermore, KTA treatment reduced the expression of ECM proteins, including vascular endothelial growth factor (VEGF), collagen I and III, whereas HIF-1α overexpression abolished the effects of KTA on KDFs. In conclusion, our findings provide novel insights into the mechanisms of action of KTA as a potential therapeutic agent for keloids via modulating HIF-1α expression., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Sorafenib has been used to enhance the survival outcome of hepatocellular carcinoma (HCC) patients. But, occurrence resistance to sorafenib subtracts from its therapeutic benefits. Herein, we identified that FOXM1 was markedly upregulated in both tumor samples and sorafenib-resistant HCC tissues. We also demonstrated that patients with decreased FOXM1 expression had longer overall survival (OS) and progression-free survival (PFS) in the cohort of sorafenib-treated patients. For HCC cells resistant to sorafenib, the IC50 value of sorafenib and the expression of FOXM1 were increased. In addition, Downregulation of FOXM1 expression alleviated the occurrence of resistance to sorafenib and reduced the proliferative potential and viability of HCC cells. Mechanically, the suppression of the FOXM1 gene resulted in the downregulation of KIF23 levels. Moreover, downregulation of FOXM1 expression reduced the levels of RNA polymerase II (RNA pol II) and histone H3 lysine 27 acetylation (H3K27ac) on the KIF23 promoter, further epigenetically silencing the production of KIF23. More intriguingly, our results similarly revealed that FDI-6, a specific inhibitor of FOXM1, suppressed the proliferation of HCC cells resistant to sorafenib, as well as upregulation of FOXM1 or KIF23 abolished this effect. In addition, we found that FDI-6 combined with sorafenib significantly improved the therapeutic effect of sorafenib. Collectively, the present results revealed that FOXM augments sorafenib resistance and enhances HCC progression by upregulating KIF23 expression via an epigenetic mechanism, and targeting FOXM1 can be an effective treatment for HCC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or COVID-19) has caused a global pandemic. The SARS-CoV-2 RNA genome is replicated by a conserved "core" replication-transcription complex (RTC) containing an error-prone RNA-dependent RNA polymerase holoenzyme (holo-RdRp, nsp12-nsp7-nsp8) and a RNA proofreading nuclease (nsp14-nsp10). Although structures and functions of SARS-CoV-2 holo-RdRp have been extensively studied and ribonucleotide-analog inhibitors, such as Remdesivir, have been treated for COVID-19 patients, the substrate and nucleotide specificity of SARS-CoV-2 holo-RdRp remain unknown. Here, our biochemical analysis of SARS-CoV-2 holo-RdRp reveals that it has a robust DNA-dependent RNA polymerase activity, in addition to its intrinsic RNA-dependent RNA polymerase activity. Strikingly, SARS-CoV-2 holo-RdRp fully extends RNAs with a low-fidelity even when only ATP and pyrimidine nucleotides, in particular CTP, are provided. This ATP-dependent error-prone ribonucleotide incorporation by SARS-CoV-2 holo-RdRp resists excision by the RNA proofreading nuclease in vitro. Our collective results suggest that a physiological concentration of ATP likely contributes to promoting the error-prone incorporation of ribonucleotides and ribonucleotide-analogs by SARS-CoV-2 holo-RdRp and provide a useful foundation to develop ribonucleotide analogs as an effective therapeutic strategy to combat coronavirus-mediated outbreak., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Protein disulfide isomerase A4 (PDIA4) is highly expressed in clear cell ovarian carcinoma and lung cancer. Through analysis of TCGA database and CGGA database, we noted that PDIA4 is a key promotor of glioblastoma (GBM). However, the detailed role and molecular mechanism of PDIA4 in GBM remain unclear. In this study, the expression pattern and biological role of PDIA4 in GBM was investigated. PDIA4 was overexpressed in GBM tumor samples and cell lines and positively correlated with pathological grades in glioma patients. In addition, downregulation of PDIA4 promoted apoptosis and inhibited proliferation of GBM. Meanwhile, there was a concurrent decrease in aerobic glycolysis metabolites. Mechanistically, PDIA4 downregulation promoted the apoptosis of GBM cells by increased the expression of apoptosis pathway proteins (caspase 3, caspase 9 and Bax). Downregulation of PDIA4 decreased energy demand and inhibited GBM growth in vitro and in vivo. Besides, such effect also inhibited the PI3K/AKT/m-TOR pathway by inhibiting protein phosphorylation levels of PI3K, AKT and m-TOR. After addition of PI3K/AKT/mTOR pathway activator 740Y-P, the effect of PDIA4 knockdown on GBM was reversed. Therefore, we believe that PDIA4 regulates the proliferation via activating the PI3K/AKT/m-TOR pathway and suppression of apoptosis in glioblastoma. It could be used as a potential target for the treatment of GBM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: circ&#95;LPAR3 is an oncogene in esophageal squamous cell carcinoma. However, its role in oral squamous cell carcinoma (OSCC) is unknown., Purpose: To reveal the functions of circ&#95;LPAR3 in OSCC., Methods: Online bioinformatic analysis was performed to disclose the differential expression of circ&#95;LPAR3, VEGFC, AKT1 in OSCC and also the target predictions of miR-513b-5p. Transfection was applied in OSCC cells. RT-qPCR was used to detect the RNA expression and western blot to measure the proteins, VEGFC and phosphor-AKT1 (ser473, p-AKT1). CCK8 kit was used for viability detection and Flow cytometry for apoptosis evaluation. RNA pull-down and luciferase reporter methods were used to validate the binding sites to miR-513b-5p on circ&#95;LPAR3, VEGFC and AKT1. OSCC mice models were established to further unveil the functions of circ&#95;LPAR3 in OSCC in vivo. H&E staining and immunohistochemistry (CD34, VEGFC and p-AKT1) were further applied to analyze the pathological changes in association with circ&#95;LPAR3 downregulation., Results: circ&#95;LPAR3 was upregulated in OSCC. Its knockdown in cells could decrease cell survival and mobility and in mice model, could inhibit the tumor growth and angiogenesis. Circ&#95;LPAR3 promoted VEGFC and AKT1 activity by sponging miR-513b-5p in OSCC cells., Conclusion: Knockdown of circ&#95;LPAR3 could inhibit the OSCC progression by sponging miR-513b-5p and activating VEGFC and AKT1., Competing Interests: Declaration of competing interest No conflict of interest was found or declared by any of authors., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ethanol affects the nervous system of animals to cause a boost of feeding, sexual, verbal, and locomotor behaviors. To understand the neural mechanisms of these ethanol-induced behaviors, we investigated a neural pathway of ethanol-induced feeding behavior by guanylate cyclases and serotonin signals in C. elegans. We recorded the intracellular calcium signaling of seven sensory neurons in response to ethanol, and only found a significant increase of calcium signaling in BAG among the seven sensor neurons. And both guanylate cyclases GCY-31 and GCY-33 were crucial signaling protein of calcium response in BAG neurons. In addition, serotonin, released from NSM motor neurons, promoted feeding behavior under ethanol stimulation. And the rescue experiment of double mutant indicated the guanylate cyclases and serotonin in the same signaling pathway. So BAG neurons respond to alcohol through the promotion of intracellular calcium signaling, and then the downstream motor neurons NSM release serotonin to regulate the feeding behavior in C. elegans. These findings revealed a neural circuit to understand how the nervous system responds to ethanol and generates corresponding behavior., Competing Interests: Declaration of competing interest The authors declare that they have no potential conflicts of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Parkinson's disease (PD) is the second most common progressive neurodegenerative disease, which is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Iron deposit was found in the SNpc of PD patients and animal models, however, the mechanisms involved in disturbed iron metabolism remain unknown. Identifying the relationship between iron metabolism and PD is important for finding new therapeutic strategies. In this study, we found that transgenic overexpression (OE) of Drosophila mitoferrin (dmfrn) or knockdown of Fer3HCH significantly mitigated the reduced mitochondrial aconitase activity, abnormal wing posture, flight deficits and mitochondrial morphology defects associated with PINK1 loss-of-function (LOF). Further work demonstrated that dmfrn OE or Fer3HCH knockdown significantly rescued the impaired mitochondrial respiration in PINK1 LOF flies, indicating that dmfrn or Fer3HCH may rescue PINK1 LOF phenotypes through elevating mitochondrial bioavailable iron levels to promote mitochondrial respiration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Brain-derived neurotrophic factor (BDNF), which regulates the neuronal survival, differentiation and synaptic plasticity, has been proved to play a critical role in the pathology and treatment of several psychiatric disorders including depression. Dexamethaone (DEX) is indicated for a number of conditions in perinatal medicine, however, the long-term impact of early-life DEX exposure on BDNF expression in hippocampus remains unknown. Here we found that neonatal DEX(ND) exposure leads to insignificant change of BDNF expression levels in the adulthood, albeit increased hyperanxious and depressive-like behaviors. However, the bdnf mRNA and BDNF protein levels were significantly reduced in all the hippocampal subregions during the developmental stages, including the perinatal period and puberty. We conclude that early life DEX exposure leads to a persistent disturbance of BDNF signaling during the developmental stages, which might be associated with the life-long impairment of hippocampal function., Competing Interests: Declaration of competing interest There is no conflict of interest in this manuscript., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Collagen Triple Helix Repeat Containing 1 (CTHRC1) has been picked out as a cancer-related, secreted glycoprotein that possesses multifaceted functions such as wound repair, the formation of adipose tissue, hepatocytes fibrosis, and bone remodeling. This study aims to explore the biological function and the profound regulative mechanism of CTHRC1 in human prostate cancer (PCa). We found that CTHRC1 was upregulated in patients with PCa. The knockdown of CTHRC1 suppressed PCa cell proliferation, invasion, migration, and colony formation significantly. The expression of CTHRC1 was down-regulated and up-regulated by miR-30e-5p mimics and inhibitors, respectively, in PCa cells. The dual-luciferase reporter assay validated the binding of miR-30e-5p with CTHRC1 mRNA, indicating the regulation of CTHC1 by miR-30e-5p. In consequence, this study demonstrated that CTHRC1 acts as an oncogenic gene and targeting the miR-30e-5p-CTHRC1 axis may provide novel therapeutic treatment for PCa., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Neural differentiation is a complex process regulated by multiple signaling at different regulatory levels. Though great progresses have been made in understanding the mechanisms of neural differentiation, post-translational regulation of neural differentiation remains largely unknown. In this study, we found Prmt4, one of the methyltransferases catalyzing protein arginine methylation, is highly expressed in neural stem cells (NSCs) and associated with neural differentiation. Knockout of Prmt4 in mESCs blocked neural differentiation by inhibiting NF-κB activation. Mechanistically, Prmt4 interacts with NF-κB component p65 to promote its methylation, resulting in increased activation of NF-κB signaling during neural differentiation. Our study not only identified Prmt4 as novel regulator of neural differentiation, but also highlighted the importance of protein arginine methylation in cell fate transition., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Ophiopogonin D (OPD) is the chief pharmacological active component of the traditional Chinese herbal prescription drug-Shenmai injection (SMI), which has been used to prevent and treat cardiovascular diseases. In the present study, we investigated whether OPD protectively relieve cardiac hypertrophy against inflammation via inhibiting the expression of NF-κB and examined whether cytochrome P450 2J3 (CYP2J3)was involved in this pathway. H9c2 cells were treated with Angiotensin II (Ang II). Hypertrophy in rat was induced by administration of Ang II infusion. To evaluate the effect of OPD on disease progression and the role of CYP2J3 in this way, inflammatory mediators (NF-κB), specific hypertrophic factors and pathological change were determined in this experiment. Ang II induced hypertrophy with the elevated expression of specific hypertrophy genes and NF-κB signaling molecules. However, these inductive effects were reversed by OPD in conjunction with Ang II. Overexpression of CYP2J3 prevented the excessive expression of NF-κB. In vivo, partial pathological cardiac hypertrophy injuries were relieved after OPD treatment. OPD exerts a positive effect on alleviating cardiac hypertrophy. The mechanism is probably through inhibiting the expression of NF-κB by upregulating CYP2J3 to suppress inflammation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The development of novel anti-papillary thyroid carcinoma agents is urgent. AZD5153 is a novel and specific Bromodomain-containing protein 4 (BRD4) inhibitor. Here, we show that AZD5153 dose-dependently inhibited survival, proliferation and cell cycle progression in TPC-1 cells and primary human thyroid carcinoma cells. Yet, it was non-cytotoxic to the primary thyroid epithelial cells. AZD5153 induced caspase-3/-9 and apoptosis activation in TPC-1 cells and primary cancer cells. Its cytotoxicity in TPC-1 cells was significantly attenuated with co-treatment of the caspase inhibitors. BRD4 expression was elevated in TPC-1 and primary human thyroid carcinoma cells, but was low in the thyroid epithelial cells. BRD4-regulated proteins, including c-Myc, Bcl-2 and cyclin D1, were significantly downregulated following AZD5153 treatment in TPC-1 and primary cancer cells. In vivo, oral administration of AZD5153 at well-tolerated doses significantly inhibited TPC-1 xenograft growth in severe combined immunodeficient (SCID) mice. BRD4-dependent proteins, Myc, Bcl-2 and cyclin D1, were also downregulated in AZD5153-treated tumor tissues. Collectively, the results suggest that targeting BRD4 by AZD5153 inhibits human thyroid carcinoma cell growth in vitro and in vivo., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to determine the expression of long-chain non-coding RNA SNHG1 (lncRNA-SNHG1) in gastric carcinoma and explore its function on cancer cell proliferation., Methods: The expression of lncRNA-SNHG1 in tumor tissues and corresponding adjacent tissues from 50 patients with gastric cancer was detected with realtime-PCR. The relationships between the expression of lncRNA-SNHG1 and clinicopathological features of gastric cancer patients were analyzed. Survival analysis was performed to study the correlation between lncRNA SNHG1 expression and patient prognosis. To assess the effect of LncRNA SNHG1 on proliferation in cancer cells, cell viability and colony formation assays were conducted when lncRNA SNHG1 was upregulated or downregulated by Lentivirus or plasmid in gastric cancer cells. Furthermore, in vivo tumor assay was performed to confirm the impact of lncRNA SNHG1 on proliferation of gastric cancer., Results: The expression of lncRNA SNHG1 in gastric cancer tissues was significantly higher than that in adjacent tissues and was correlated with TNM stage, T stage, and lymph node metastasis. The survival time of patients with higher expression level of lncRNA-SNHG1 was significantly lower than that of the lower expression level. LncRNA-SNHG1 accelerated the proliferation of gastric cancer cells obviously and increased the expression of DNMT1., Conclusion: LncRNA SNHG1 promotes DNMT1 expression, which facilitates the gastric cancer proliferation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Non-small cell lung cancer (NSCLC) stemness and chemoresistance represent significant barriers to successful treatment. Downregulation of microRNA 129 (miR-129) has been implicated in a variety of cancers, and miR-129-5p has recently been shown to reduce lung cancer proliferation and metastasis. In this study, we used NSCLC cell lines A549 and H460 to investigate the effects of miR-129-5p on NSCLC stemness and chemoresistance. CD133 + stem cells in both lines showed reduced miR-129-5p expression, and introducing miR-129-5p into these cells reduced stem cell markers and self-renewal ability, as measured by qRT-PCR, western blot, MTT assays, and sphere formation assays. MTT, colony formation, and DAPI staining assays further revealed that miR-129-5p inhibits NSCLC chemoresistance when the cells are treated with varying doses of CDDP. The target prediction algorithm TargetScan allowed us to identify notch signaling receptor delta-like 1 homolog (DLK1) as a potential target for miR-129-5p in its inhibition of NSCLC stemness and chemoresistance. Indeed, our DLK1 luciferase reporter plasmid demonstrated that miR-129-5p reduces DLK1 expression. Furthermore, DLK1 overexpression partially rescued inhibition of NSCLC stemness and chemoresistance caused by miR-129-5p. Overall, these results demonstrate that miR-129-5p inhibits NSCLC stemness and chemoresistance through direct targeting of DLK1. They suggest that miR-129-5p and DLK1 can play a role in an effective treatment strategy for NSCLC., (Copyright © 2017 Elsevier Inc. All rights reserved.)

LncRNAs were altered in several cancers and played a crucial role in various biological activities and progressions of different diseases, including proliferation, chemical resistance, and metastasis. In the present study, we revealed that prostrate androgen-regulated transcript-1 (PART-1) was highly expressed in colorectal cancer cells and tissues, and knockdown of PART-1 suppressed cell proliferation and metastasis, both in vitro and in vivo. In addition, PART-1 functioned as a ceRNA of DNMT3A, by sponging miR-143. Finally,PART-1 induced tumor progression by regulating DNMT3A., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Osteoporosis is a skeletal disorder characterized by bone loss, resulting in architectural deterioration of the skeleton, decreased bone strength and an increased risk of fragility fractures. Strengthening osteogenesis is an effective way to relieve osteoporosis. Sirtuin1 (Sirt1) is a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase, which is reported to be involved in improving osteogenesis. Sirt1 targets peroxisome proliferator-activated receptor γ (PPARγ) in the regulation of adipose tissues; however, the molecular mechanism of Sirt1 in osteogenic differentiation is still unknown. PPARγ tends to induce more adipogenic differentiation rather than osteogenic differentiation. Hence, we hypothesized that Sirt1 facilitates osteogenic differentiation through downregulation of PPARγ signaling. Mouse pre-osteoblastic MC3T3-E1 cells were cultured under osteogenic medium. Sirt1 was overexpressed through plasmid transfection. The results showed that high expression of Sirt1 was associated with increased osteogenic differentiation, as indicated by quantitative PCR and Western blot analysis of osteogenic markers, and Von Kossa staining. Sirt1 overexpression also directly and negatively regulated the expression of PPARγ and its downstream molecules. Use of the PPARγ agonist Rosiglitazone, reversed the effects of Sirt1 on osteogenic differentiation. Using constructed luciferase plasmids, we demonstrated a role of Sirt1 in inhibiting PPARγ-induced activity and expression of adipocyte-specific genes, including acetyl-coenzyme A carboxylase (Acc) and fatty acid binding protein 4 (Fabp4). The interaction between Sirt1 and PPARγ was further confirmed using co-immunoprecipitation analysis. Together, these results reveal a novel mechanism for Sirt1 in osteogenic differentiation through downregulation of PPARγ activity. These findings suggest that the Sirt1-PPARγ pathway may represent a potential target for enhancement of osteogenesis and treatment of osteoporosis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis. Expression of microRNAs (miRNAs) has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. The function of miR-935 has never been reported in cancer before. We found, using microRNA array, that expression of miR-935 in GSRCC cell lines is lower than in non-GSRCC cell lines, and enhanced expression of miR-935 in GSRCC cell-lines inhibit cell proliferation, migration and invasion. We also identified Notch1 as a direct target of miR-935. Knockdown of Notch1 reduced proliferation, migration/invasion of GSRCC cells, and overexpression Notch1's activated form (Notch intracellular domain) could rescue miR-935's tumor suppressive effect on GSRCC. Expression of miR-935 was lower in gastric carcinoma tissue than in paired normal tissue samples, and lower in GSRCC than in non-GSRCC. Our results demonstrate the inverse correlation between the expression of miR-935 and Notch1 in gastric tissues. We conclude that miR-935 inhibits gastric carcinoma cell proliferation, migration and invasion by targeting Notch1, suggesting potential applications of the miR-935-Notch1 pathway in gastric cancer clinical diagnosis and therapeutics, especially in gastric signet ring cell carcinoma., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Myogenesis is a complex process including myoblast proliferation, differentiation and myotube formation and is controlled by myogenic regulatory factors (MRFs), MyoD, MyoG, Myf5 and Myf6 (also known as MRF4). MicroRNA is a kind of ∼22 nt-long non-coding small RNAs, and act as key transcriptional or post-transcriptional regulators of gene expression. Identification of miRNAs involved in the regulation of muscle genes could improve our understanding of myogenesis process. In this study, we investigated the regulation of Myf6 gene by miRNAs. We showed that miR-374b specifically bound to the 3'untranslated region (UTR) of Myf6 and down-regulated the expression of Myf6 gene at both mRNA and protein level. Furthermore, miR-374b is ubiquitously expressed in the tissues of adult C57BL6 mouse, and the mRNA abundance increases first and then decreases during C2C12 myoblasts differentiation. Over-expression of miR-374b impaired C2C12 cell differentiation, while inhibiting miR-374b expression by 2'-O-methyl antisense oligonucleotides promoted C2C12 cell differentiation. Taken together, our findings identified miR-374b directly targets Myf6 and negatively regulates myogenesis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Gastric cancer (GC) is a prevalent malignant cancer worldwide and is highly lethal because of its fast growth. Currently, the clinical therapy options for GC remain limited. MiR-32 has been reported as an oncogenic microRNA in many cancers, but its role in GC is unclear. Here, we found that miR-32 was overexpressed in GC tissues compared with adjacent normal tissue, and miR-32 was higher in GC patients' plasma compared with healthy individuals. Furthermore, we have identified miR-32 to be oncogenic, by promoting gastric cell proliferation, migration and invasion. We also identified Kruppel-like factor 4 (KLF4) as a direct target of miR-32. Knockdown of KLF4 promoted proliferation, migration and invasion of GC cells. We conclude that miR-32 promotes GC cell proliferation, migration and invasion by targeting KLF4, suggesting that the miR-32-KLF4 pathway may be useful in clinical diagnosis and therapeutics., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Influenza A virus (IAV) infection induces secretion of type I interferon (IFN) and activation of p53, which play essential roles in the host defense against tumor development and viral infection. In this study, we knocked down p53 expression by RNA interference. The expression levels of IFN-stimulated genes (ISGs) including IFN regulatory factor (IRF) 5, IRF9, ISG15, ISG20, guanylate-binding protein 1, retinoic acid-inducible gene-I and 2'-5'-oligoadenylate synthetase 1 were significantly attenuated in response to IAV infection and IFN-α stimulation in p53-knockdown cells. This attenuated expression of ISGs was associated with enhanced replication of IAV. Pretreatment of p53-knockdown cells with IFN-α failed to inhibit IAV replication, indicating impaired antiviral activity. These findings indicate that p53 plays an essential role in the enhancement of the type I IFN-mediated immune response against IAV infection., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Brown adipose tissue (BAT) is specialized to dissipate energy as heat, therefore reducing fat deposition and counteracting obesity. Brown adipocytes arise from myoblastic progenitors during embryonic development by the action of transcription regulator PRDM16 binding to PPARγ, which promotes BAT-like phenotype in white adipose tissue. To investigate the capability of converting white adipose tissue to BAT or browning by PPARγ in vivo, we generated transgenic mice with over-expressed PPARγ2. The transgenic mice showed strong brown fat features in subcutaneous fat in morphology and histology. To provide molecular evidences on browning characteristics of the adipose tissue, we employed quantitative real-time PCR to determine BAT-specific gene expressions. The transgenic mice had remarkably elevated mRNA level of UCP1, Elovl3, PGC1α and Cebpα in subcutaneous fat. Compared with wild-type mice, UCP1 protein levels were increased significantly in transgenic mice. ATP concentration was slightly decreased in the subcutaneous fat of transgenic mice. Western blotting analysis also confirmed that phosphorylated AMPK and ACC proteins were significantly (P<0.01) increased in the transgenic mice. Therefore, this study demonstrated that over-expression of PPARγ2 in skeletal muscle can promote conversion of subcutaneous fat to brown fat formation, which can have beneficial effects on increasing energy metabolisms and combating obesity., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Isolated pancreatic islets containing the insulin-producing beta cells are devoid of circulation. They may therefore experience hypoxia with possible negative effects on beta cell function and survival. We investigated (1) whether hyperoxia in vitro would be beneficial by counteracting putative effects of lost circulation and, further, (2) whether previous hyperoxia would attenuate the impact of subsequently induced severe hypoxia. Islets from Sprague-Dawley rats were exposed to 95% O2 for 18 h. This hyperoxic exposure diminished glucose-induced insulin secretion by 47% and inhibited oxygen consumption by 39-41%. Mitochondrial complexes I-III were decreased by 29-37%. Negative effects on insulin secretion and complexes III and IV waned after a 22 h period of normoxia following hyperoxia whereas complexes I and II were still diminished, ROS production was increased and rates of apoptosis tended to be increased (P=0.07). The effects of previous hyperoxia on susceptibility to damage by subsequent hypoxia were tested after 5.5h of 0.8% O2. Previous hyperoxia did not affect hypoxia-induced enhancement of HIF-1 alpha but modestly and significantly attenuated hypoxia-induced decreases in insulin contents. We conclude that hyperoxia exerts largely negative effects on beta cells, effects which are functional and possibly also toxic. A paradoxical positive finding (attenuation of hypoxia-induced effects) could be secondary to a protective effect of the hyperoxia-induced reduction of oxidative metabolism., (Copyright © 2013. Published by Elsevier Inc.)

Spatiotemporal control of transgene expression in living cells provides new opportunities for the characterization of gene function in complex biological processes. We previously reported a synthetic, light-switchable transgene expression system called LightOn that can be used to control gene expression using blue light. In the present study, we modified the different promoter segments of the light switchable transcription factor GAVPO and the target gene, and assayed their effects on protein expression under dark or light conditions. The results showed that the LightOn system maintained its high on/off ratio under most modifications, but its induction efficiency and background gene expression level can be fine-tuned by modifying the core promoter, the UASG sequence number, the length of the spacer between UASG and the core promoter of the target protein, and the expression level of the GAVPO transcription factor. Thus, the LightOn gene expression system can be adapted to a large range of applications according to the requirements of the background and the induced gene expression., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Genes that are specific to germline and embryonic development can be activated in many tumors. Here, we show that germline traits that are present in human hepatoblastoma cells might be associated with the malignant behaviors of these tumor cells. In culture, single human hepatoblastoma cells differentiated into germ cell-like cells, which further developed into oocyte-like cells and formed parthenogenetic blastocyst-like structures. The germ cell-like cells and their embryonic derivatives from hepatoblastoma cells may favorably give rise to xenograft tumors with embryonal/germline traits and intrahepatic metastasis. These findings suggest that germline potential can be spontaneously activated in human hepatoblastoma cells and it might be important for tumor formation and metastasis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Human guanylate-binding protein 1 (hGBP1) plays an important role in antitumor and antiviral immune responses. Here, we show that tumor suppressor p53 positively regulated hGBP1 transcription via binding to the p53 response element (p53RE) present in the hGBP1 promoter region. p53 activation by 5-fluorouracil significantly increased hGBP1 expression in wild-type p53 cells, but not in p53-null cells. Knockdown of p53 expression remarkably impaired hGBP1 expression induced by 5-fluorouracil, type I interferon treatment, or influenza A virus infection. Among three deductive p53REs present in the hGBP1 promoter region, two p53REs were found to be transactivated by p53., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Matrix metalloproteinase-1 (MMP-1) is a member of the family of zinc-dependent endopeptidases that are capable of degrading extracellular matrix (ECM) and certain non-matrix proteins. It has been shown that MMP-1 can enhance muscle regeneration by improving the differentiation and migration of myoblasts. However, it is still not known whether MMP-1 can promote the myogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). To address this question, we isolated BMSCs from C57BL/6J mice and investigated the effects of MMP-1 on their proliferation and myogenic differentiation. Our results showed that MMP-1 treatment, which had no cytotoxic effects on BMSCs, increased the mRNA and protein levels of MyoD and desmin in a dose-dependent manner, indicating that MMP-1 promoted myogenic differentiation of BMSCs in vitro. These results suggest that BMSCs may have a therapeutic potential for treating muscular disorders., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 μg/ml of doxycycline (dox) induced UCP-2 fourfold (424 ± 113%, mean±SEM) and 0.1 μg/ml twofold (178 ± 29%, n=3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 ± 11%) as well as D-[U-(14)C]-glucose oxidation (+5 ± 9% at 11 mM glucose). Oxidation of [1-(14)C]-oleate was increased from 4088 to 5797 fmol/μg prot/2h at 3.3mM glucose, p<0.03. Oxidation of L-[(14)C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p<0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p<0.025. Testing for the lower level of UCP-2 induction did not reproduce any of the positive findings. A fourfold induction of UCP-2 was required to exert minor metabolic effects. These findings question an impact of moderately elevated UCP-2 levels in beta cells as seen in diabetes., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Plaminogen activator inhibitor-1 (PAI-1), the key physiological inhibitor of the plasmin fibrinolytic system, plays important roles in the pathogenesis of asthma. Mast cells (MCs) are crucial effector cells and a major source of PAI-1 for asthma. Cyclic adenosine monophosphate (cAMP) is the important regulator of MCs; however, its effects on PAI-1 expression in MCs remain unknown. We reported cAMP/protein kinase A pathway positively regulates PAI-1 expression through cAMP-response element binding protein binding to hypoxia response element-1 at -158 to -153bp of human PAI-1 promoter in human MCs. Moreover, cAMP synergistically augments PAI-1 expression with ionomycin- or IgE receptor cross-linking-mediated stimulation., (Copyright © 2010 Elsevier Inc. All rights reserved.)

NS1 protein of influenza A virus is involved in regulating the apoptosis of infected cells. We found that exogenously expressed NS1 was able to associate with the tumor suppressor p53 that plays an essential role in regulating apoptosis of influenza A virus-infected cells. Exogenous expression of NS1 resulted in inhibition of p53-mediated transcriptional activity and apoptosis. The p53 inhibitory domain of NS1 was located between amino acids 144 and 188. This domain is necessary for NS1 to inhibit p53 activity, but it requires additional region(s) to cooperatively exert this inhibitory function., (2010 Elsevier Inc. All rights reserved.)

Sinomenine (SIN) is an alkaloid isolated from the Chinese medicinal plant Sinomenium acutum. It is widely used as an immunosuppressive drug for treating autoimmune diseases. Due to its poor efficiency, the large-dose treatment presents some side effects and limits its further applications. In this study, we used chemical modification to improve the therapeutic effect of SIN in vitro and in vivo. A new derivative of sinomenine, named 1032, demonstrates significantly improved immunosuppressive activity over that of its parent natural compound (SIN). In an experimental autoimmune encephalomyelitis (EAE) model, 1032 significantly reduced encephalitogenic T cell responses and induced amelioration of EAE, which outcome was related to its selective inhibitory effect on the production of IL-17. By contrast, SIN treatment only led to a moderate alleviation of EAE severity and the expression level of IL-17 was not significantly reduced. Furthermore, 1032 exhibited suppression of Th17, but not Treg, cell differentiation, a result probably related to its inhibitory effect on IkappaB-alpha degradation as well as on IL-6 and TNF-alpha secretion in BMDCs. We speculate that 1032 as a novel anti-inflammatory agent may target DC to block IL-6 production, which in turn would terminate Th17 cell development. Thus, SIN derivative 1032 presents considerable potential in new drug development for treating autoimmune and inflammatory disease., (Copyright 2009 Elsevier Inc. All rights reserved.)

Tumor suppressor p53, the major cellular defense against tumor development, has recently been implicated in host antiviral defense. Previous studies have shown that p53 was induced at the apoptotic stage of influenza virus-infected cells. However, we found that p53 was induced not only at the apoptotic stage but also at the beginning phase of infection, showing a biphasic pattern with a first transient elevation apparent at the beginning phase of infection and a second elevation observable at the middle-late phase of infection. This up-regulation of p53 was independent of increased p53 transcription, but dependent on virus adsorption and replication. The increased p53 was active and able to transactivate its downstream target genes, such as interferon regulatory factor 9 (IRF9) and Bax. To our knowledge, this is the first report to describe a biphasic pattern of p53 accumulation in influenza virus-infected cells.

Although the tumor suppressor protein p53 is important in the control of various cellular activities, the analysis of p53 in the porcine model has been hampered by a lack of a suitable antibody that is specific for porcine p53. Using a recombinant porcine p53, we generated a rabbit polyclonal antibody (designated SH0797) that is directed against porcine p53. The results of the study show that the antibody is capable of detecting recombinant p53 protein expressed in Escherichia coli, as well as FLAG-tagged p53 that is expressed in the transfected cells. This demonstrates that the antibody is specific for the porcine p53 protein. The antibody also showed the ability to immunoprecipitate p53 protein from extracts of porcine cells and to cross-react with human p53 protein. In addition, expression of porcine p53 could be induced readily in porcine cells and detected using this new tool. This antibody is a useful tool for use in studies of the cellular pathways that involve p53 in the porcine model.

RNA interference mediated by small interfering RNAs (siRNAs) shows promise as a powerful research tool for gene function studies. However, controversy exists over the potential of siRNA-induced interferon response in vitro and in vivo. In this study, we showed that although intravenous administration of siRNA alone is essentially inert, injection of siRNA complexed with cationic liposomes resulted in a potent induction of both type I and type II interferon responses. Furthermore, i.v. administration of cationic lipid/siRNA complexes led to activation of STAT1. This study suggests caution in data interpretation and the potential toxicity with in vivo use of siRNA, particularly when delivered via a cationic lipid vector. This study also suggests the potential of siRNA as an immunostimulatory agent for immunotherapy.

Regulation of SNARE proteins by glucose in pancreatic islets is complex and insufficiently clarified. We aimed to study effects of glucose per se separate from enhancing effects on exocytosis. A 24h culture of rat islets at elevated glucose (27 mmol/L) increased t-SNARES (SNAP-25, syntaxin) (Western blotting). Co-culture with diazoxide, which inhibits glucose-induced insulin secretion, reversed these effects. Effects on SNAP-25 were similar in human and rat islets. Effects of diazoxide were mimicked by blocking secretion with somatostatin (rat islets). Blocking secretion by cooling abolished both glucose and diazoxide effects on SNAP-25. Total SNAP-25 mRNA as well as isoforms alpha and beta were increased by 24-h elevated glucose. Diazoxide failed to reverse the glucose effects on mRNA. However, effects of diazoxide on SNAP-25 protein were nullified by proteasome inhibitors (ALLN, MG-132, and epoxomicin) but not by lysosomal inhibition (NH(4)Cl). Exocytosis per se modifies SNAREs by a process linked to proteasomal activation.

Peptide nucleic acid (PNA) is a DNA/RNA mimic in which the phosphodiester (PO) linkage is replaced with a peptide bond. It has a number of unique properties compared to currently used oligonucleotides including higher affinity towards RNA or DNA target, resistance to nucleases or proteases, and minimal non-specific interactions with proteins. Clinical applications of PNA, however, are limited by its inefficient intracellular delivery. In this study, we have shown that delivery of PNA to pulmonary endothelium in intact mice can be greatly improved via hybridization with a short PO oligonucleotide that serves as a carrier to form complexes with cationic liposomes. We have also shown for the first time that unlike a CpG DNA oligo that is highly proinflammatory, a CG-containing PNA is inert in triggering TNF-alpha response in cultured macrophages and in mice. Thus delivery of PNA to pulmonary endothelium may prove to be a therapeutically useful for the treatment of pulmonary vascular diseases.

The antitumor agent paclitaxel (Taxol) mimics the actions of lipopolysaccharide (LPS) on murine macrophages (M phi). Recently, we have shown that the benzoyl group at the C-3' position of paclitaxel is the most important site to induce nitric oxide (NO) and tumor necrosis factor (TNF) production by C3H/HeN M phi (Biochem. Biophys. Res. Commun. 210, 678-686, 1996). In the present study, synthetic analogs of paclitaxel with replacement of the C-3'-N position were examined for their potencies to induce NO and TNF production by peritoneal M phi of LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice, by human blood cells and human M phi. In this structure-activity relationship study, we found that (i) the p-substitution of the benzoyl group definitely affects the activity to activate C3H/HeN M phi, (ii) the analogs having a methyl or chloro group at the p-position exhibit stronger activity than that of paclitaxel, (iii) there is good correlation between NO and TNF production by the M phi in response to compounds, (iv) the compounds tested do not induce either NO or TNF production by C3H/HeJ M phi or TNF production by human cells, (v) a previous treatment of C3H/HeN M phi with the inactive compounds can hardly affect either paclitaxel- or LPS-induced TNF production by the M phi, (vi) paclitaxel and its analogs marginally affect LPS-induced TNF production by human blood cells, and (vii) there is no correlation between the NO/TNF inducibility to C3H/HeN M phi and growth inhibitory activity against M phi-like J774.1 and J7.DEF3 cells.

Taxol (paclitaxel), a microtubule stabilizer with antitumor activity, mimics the actions of lipopolysaccharide (LPS) on murine macrophages (M phi). In the present study, a variety of synthetic analogs of paclitaxel were examined for their potencies to induce nitric oxide (NO) and tumor necrosis factor (TNF) production by peritoneal M phi from LPS-responsive C3H/HeN, and LPS-hyporesponsive C3H/HeJ mice, and by M phi-like LPS-responsive J774.1 and its mutant LPS-hyporesponsive J7.DEF3 cells. In this structure-activity relationship study, we found that (i) the benzoyl group at the C-3' position of paclitaxel is the most important site to activate C3H/HeN M phi; (ii) the phenyl group at C-3' is not a requisite for the activity; (iii) there is good correlation between NO and TNF production by the M phi in response to compounds, except for the analogs having a tert-butoxycarbonyl (10-acetyldocetaxel) or a thiophene-2-carbonyl group at C-3'-N instead of a benzoyl group, which is more dominant in TNF than in NO production; (iv) the compounds tested induce neither NO nor TNF production by C3H/HeJ M phi; (v) active compounds to C3H/He M phi induce TNF production by J7.DEF3 cells as well as J774.1 cells; and (vi) there is no correlation between the NO/TNF inducibility to C3H/HeN M phi and growth inhibitory activity against M phi-like J774.1 and J7.DEF3 cells. These data also suggest that the binding of taxoid/LPS to tubulin is not essential for the M phi activation.