Search

DNA replication stress threatens genome stability and is a hallmark of cancer in humans. The evolutionarily conserved kinases ATR (ATM and RAD3-related) and WEE1 are essential for the activation of replication stress responses. Translational control is an important mechanism that regulates gene expression, but its role in replication stress responses is largely unknown. Here we show that ATR–WEE1 control the translation of SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a master transcription factor required for replication stress responses in Arabidopsis thaliana. Through genetic screening, we found that the loss of GENERAL CONTROL NONDEREPRESSIBLE 20 (GCN20) or GCN1, which function together to inhibit protein translation, suppressed the hypersensitivity of the atr or wee1 mutant to replication stress. Biochemically, WEE1 inhibits GCN20 by phosphorylating it; phosphorylated GCN20 is subsequently polyubiquitinated and degraded. Ribosome profiling experiments revealed that that loss of GCN20 enhanced the translation efficiency of SOG1, while overexpressing GCN20 had the opposite effect. The loss of SOG1 reduced the resistance of wee1 gcn20 to replication stress, whereas overexpressing SOG1 enhanced the resistance to atr or wee1 to replication stress. These results suggest that ATR–WEE1 inhibits GCN20–GCN1 activity to promote the translation of SOG1 during replication stress. These findings link translational control to replication stress responses in Arabidopsis. The ATR–WEE1 kinase-mediated activation of SUPPRESSOR OF GAMMA RESPONSE 1 translation links translational control to replication stress responses in Arabidopsis. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a notorious pathogen responsible for various severe diseases. Due to the emergence of drug-resistant strains, the prevention and treatment of S. aureus infections have become increasingly challenging. Vancomycin is considered to be one of the last-resort drugs for treating most methicillin-resistant S. aureus (MRSA), so it is of great significance to further reveal the mechanism of vancomycin resistance. VraFG is one of the few important ABC (ATP-binding cassette) transporters in S. aureus that can form TCS (two-component systems)/ABC transporter modules. ABC transporters can couple the energy released from ATP hydrolysis to translocate solutes across the cell membrane. In this study, we obtained a strain with decreased vancomycin susceptibility after serial passaging and selection. Subsequently, whole-genome sequencing was performed on this laboratory-derived strain MWA2 and a novel single point mutation was discovered in vraF gene, leading to decreased sensitivity to vancomycin and daptomycin. Furthermore, the mutation reduces autolysis of S. aureus and downregulates the expression of lytM , isaA , and atlA. Additionally, we observed that the mutant has a less net negative surface charge than wild-type strain. We also noted an increase in the expression of the dlt operon and mprF gene, which are associated with cell surface charge and serve to hinder the binding of cationic peptides by promoting electrostatic repulsion. Moreover, this mutation has been shown to enhance hemolytic activity, expand subcutaneous abscesses, reflecting an increased virulence. This study confirms the impact of a point mutation of VraF on S. aureus antibiotic resistance and virulence, contributing to a broader understanding of ABC transporter function and providing new targets for treating S. aureus infections. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by the infiltration of macrophages in the fibrotic region. Currently, no therapeutic strategies effectively control disease progression, and the 5‐year mortality of patients after diagnosis is unacceptably high. Thus, developing an effective and safe treatment for IPF is urgently needed. The present study illustrated that methyl‐CpG‐binding protein 2 (MECP2), a protein responsible for the interpretation of DNA methylome‐encoded information, was abnormally expressed in lung and bronchoalveolar lavage fluid samples of IPF patients and mice with onset of pulmonary fibrosis. And further studies verified that the overexpression of MECP2 occurred mainly in macrophages. Inhibition of Mecp2 expression in macrophages robustly abrogated alternatively activated macrophage (M2) polarization by regulating interferon regulatory factor 4 expression. Accordingly, cationic liposomes loading Mecp2 small interfering RNA (siRNA) were raised for the treatment of pulmonary fibrosis. It was noted that the liposomes accumulated in the fibrotic region after intratracheal injection, especially in macrophages. In addition, intratracheal administration of Mecp2 siRNA‐loaded liposomes significantly reversed the established pulmonary fibrosis with few side‐effects and high safety coefficients. Collectively, these results are essential not only for further understanding the DNA methylation in pathogenesis of IPF but also for providing a potent therapeutic strategy for IPF treatment in the clinic practice. [ABSTRACT FROM AUTHOR]

Background: The purpose of the current study was to explore the role and underlying mechanism of FGF-2 in dexamethasone (DEX)-induced apoptosis in MC3T3-E1 cells. Methods: GSE21727 was downloaded from the Gene Expression Omnibus (GEO) database to identify the differentially expressed genes (DEGs) by the limma/R package. MC3T3-E1 cells were exposed to DEX at different concentrations (0, 10−8, 10−7, 10−6, 10−5 and 10−4 mol/L), and cell viability, flow cytometry and TUNEL assay were used to detect cell proliferation and apoptosis. An FGF-2-pcDNA3 plasmid (oe-FGF-2) was used to overexpress FGF-2, and western blotting was conducted to detect protein expression. Results: We found that FGF-2 was downregulated in the DEX-treated group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that DEGs were associated with PI3K/Akt signaling pathway. DEX downregulated FGF-2 gene and protein expression, inhibited viability and induced MC3T3-E1 cell apoptosis. Overexpression of FGF-2 reversed DEX-induced apoptosis in MC3T3-E1 cells. FGF-2-mediated anti-apoptosis was impaired by inactivating the PI3K/AKT pathway with LY294002. Moreover, overexpression of FGF2 delayed the progression of DEX-induced osteonecrosis of the femoral head (ONFH) animal model by regulation PI3K/Akt signaling pathway. Conclusion: In conclusion, FGF-2 is effective at inhibiting DEX-induced MC3T3-E1 cell apoptosis through regulating PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the relationship between the DNA mismatch repair (MMR) status and histone lysine‐specific demethylase 6A (KDM6A) on the prognosis of colorectal cancer (CRC). Methods: About 594 patients with CRC from The Cancer Genome Atlas (TCGA) were enrolled in this retrospective study. Subsequently, a series of different classification tests for MMR status, cancer types, and target gene expression was conducted. Results: After filtering out the KDMs group of genes, we selected KDM6A as the target gene. A significant difference in the performance of KDM6A in tumor and normal tissues were confirmed. Our results showed a lower KDM6A expression, lower KDM6A exon expression, and higher KDM6A DNA methylation than their corresponding normal tissues in colon adenocarcinoma (COAD). Notably, the main MMR genes were highly expressed in tumor tissues than normal tissues both in COAD and rectum adenocarcinoma (READ). Moreover, proficient DNA mismatch repair (pMMR) was found to be an important poor prognostic factor in COAD (p = 0.0064) and the low KDM6A expression was an important factor for poor prognosis in READ (p = 0.0217). Based on these results, we consequently relate MMR status with KDM6A expression in predicting the prognosis of patients with CRC. Moreover, patients with pMMR exhibited a low KDM6A expression in COAD (p = 0.0250). Samples were divided into two groups based on the KDM6A expression. Interestingly, the group with low KDM6A expression showed no difference between pMMR and deficient DNA mismatch repair (dMMR) in prognosis, whereas the group with high KDM6A expression was closely related to MMR status in OS (p = 0.0082). Besides, COAD patients with high KDM6A expression and pMMR status had poor OS (p = 0.0082). Conclusions: The KDM6A/MMR classification‐based subtypes of low KDM6A expression/READ, high KDM6A expression/pMMR, and COAD/pMMR were associated with poor prognosis. This classification can be a novel prognostic approach in CRC. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovitis. Succinate is an inflammatory metabolic signal that exacerbates RA synovitis by activating succinate receptor 1 (SUCNR1) to amplify the release of IL-1β. Thus, inhibition of succinate activation of SUCRN1 could be an effective method to inhibit the inflammation of RA. Baihu Jia Guizhi decoction (BHGZ), which is composed of Gypsum Fibrosum, Anemarrhena asphodeloides Bge., Cinnamomum cassia Presl., Glycyrrhiza uralensis Fisch., and Oryza sativa L., is a Traditional Chinese Medicine (TCM) prescription used to treat RA in clinic. In addition, TCM believes that damp and heat environment is one of the causes of RA. In this study, we tested the role of damp and heat environments in exacerbating RA inflammation and the anti-inflammatory effect of BHGZ, based on succinate/SUCNR1/IL-1β pathway in the adjuvant arthritis (AA) model with damp and heat environment (AA + DHE). Results showed that paw swelling and synovial pathology were significantly increased in AA rats, and these results were aggravated by stimulation in damp and heat environment. BHGZ improved AA + DHE rats' paw swelling, synovial hyperplasia, and inflammatory cell infiltration and reduced IL-1β. In addition, AA rats significantly increased the expression of SUCNR1, and the stimulation of damp and heat environment not only increased the expression of SUCNR1 but also promoted the accumulation of succinate. BHGZ simultaneously reduced the concentration of succinate and the expression of SUCNR1. Finally, SDH activity was decreased in AA rats and AA + DHE rats, while BHGZ increased SDH activity and then reduced succinate concentration. Therefore, we prove that damp and heat environment deteriorated the inflammation of RA which is the activation of succinate/SUCNR1 pathway, while BHGZ regulates SDH activity to reduce the accumulation of succinate and inhibit the activation of SUCNR1 that is the underlying mechanism of its treatment of RA. [ABSTRACT FROM AUTHOR]

Clematidis Radix et Rhizoma, a kind of traditional Chinese medicine, is derived from Clematis chinensis Osbeck, Clematis hexapetala Pall. and Clematis manshurica Rupr. This herb shows great effects on expelling wind and dispelling dampness in ancient and it has anti-inflammatory and analgesic activity in modern clinical application. This experiment aimed to research anti-rheumatoid arthritis effect of crude and wine processed RC based on glycolysis metabolism to provide new ideas treating RA. Network pharmacology was applied to preliminarily forecast the potential pathways of common targets of RC and RA. RAW264.7 macrophages were induced by LPS, NO production, glucose uptake, lactate production, ROS and MMP were detected as instructions in vitro. ELISA was used to measure the content of HK2, PKM2 and LDHA involving in glycolysis process. Gut microbiota was analyzed by 16S rRNA gene amplicon sequencing in CIA rats. Crude and wine processed RC had good anti-inflammatory effect by reducing NO in RAW264.7 macrophages and ameliorating inflammatory infiltration and cartilage surface erosion in CIA rats. Whether in LPS-induced macrophages or CIA rats, crude and wine processed RC could inhibit glycolysis by down-regulating the expression of PKM2, causing less glucose uptake and lactic acid, which lead to less ROS and higher MMP to normal. PI3K-AKT and HIF-1α pathways were deduced to possibly play a crucial part in controlling glycolysis metabolism by network pharmacology analysis. Besides, it was displayed that Firmicutes and Bacteroidetes were prominent gut microbiota in CIA rats feces. CC-H and PZ-H groups could both increase the relative abundance of Firmicutes and decrease Bacteroidetes. These microbiota also played a role in RA pathological process via involving in energy metabolism, carbohydrate metabolism and immune system. Crude and wine processed RC have a good influence in ameliorating rheumatoid arthritis by inhibiting glycolysis and modulating gut microbiota together. [Display omitted] • Thermal and wine processed RC had good anti-inflammatory effects to ameliorate RA in vitro and vivo. • Thermal and wine processed RC inhibited glycolysis via mainly decreasing PKM2 in vitro and vivo. • The gut microbiota Roseburia and Prevotella were related with glycolytic enzyme PKM2 and LDHA. • PI3K-AKT pathway and HIF-1α pathway were deduced to be closed with glycolysis metabolism by network pharmacology analysis. • Thermal and wine processed RC may treat RA through inhibiting glycolysis combined with modulating gut microbiota. [ABSTRACT FROM AUTHOR]

The chloroplast is a semi-autonomous organelle with its own genome. The expression of chloroplast genes depends on both chloroplasts and the nucleus. Although many nucleus-encoded proteins have been shown to localize in chloroplasts and are essential for chloroplast gene expression, it is not clear whether transcription factors can regulate gene expression in chloroplasts. Here we report that the transcription factor NAC102 localizes in both chloroplasts and nucleus in Arabidopsis. Specifically, NAC102 localizes in chloroplast nucleoids. Yeast two-hybrid assay and co-immunoprecipitation assay suggested that NAC102 interacts with chloroplast RNA polymerases. Furthermore, overexpression of NAC102 in chloroplasts leads to reduced chloroplast gene expression and chlorophyll content, indicating that NAC102 functions as a repressor in chloroplasts. Our study not only revealed that transcription factors are new regulators of chloroplast gene expression, but also discovered that transcription factors can function in chloroplasts in addition to the canonical organelle nucleus. [ABSTRACT FROM AUTHOR]

microRNAs (miRNAs) play an important role in gene regulation in animals by pairing with target gene mRNA. Many miRNAs are differentially expressed in the adipose tissue, often with conserved expression. In our study, we found that miR-208b expression was observed differently in the preadipocyte differentiation model. When miR-208b was overexpressed in the preadipocyte differentiation model, the overexpressed group displayed higher expression of PPARγ and FABP4—the markers of preadipocyte differentiation. Oil Red O staining revealed that the count of lipid droplets was increased in the overexpressed group. When the expression of miR-208b was inhibited, the above indicators showed an opposite trend. Moreover, results from both 5-ethynyl-2′-deoxyuridine (EDU) and cell counting kit (CCK) analysis showed that miR-208b promoted the proliferation of preadipocyte. Expression of gene CSNK2A2, a direct miR-208b target, was downregulated in the overexpressed group, providing a possible link to multiple signal pathways. Overall, our data indicate that miR-208b play a positive regulatory effect on the proliferation and differentiation of rabbit preadipocyte. [ABSTRACT FROM AUTHOR]

XANTHOMONAS RESISTANCE 21-binding protein3 (XB3) is the first characterized XA21 interacting protein required for plant immunity. We isolated GhXB32A that is similar to XBAT32 and was induced during inoculation of Verticillium dahliae in cotton. 32 putative XB3 family genes were identified in G. hirsutum, G. arboreum, and G. raimondii. Cis -Acting elements related to growth, stresses, and phytohormone were detected in the promoter regions. GhXB3s were ubiquitously expressed in different cotton tissues with different patterns. Most GhXB3s were down-regulated by cold stress, but up-regulated by heat, salt, PEG, V. dahliae , ethylene, and some were up-regulated by SA or MeJA. Silencing GhXB32A and GhXB32D greatly improved resistance to Verticillium wilt, while silencing GhXB35A(D) or GhXB37A(D) made them more susceptible to V. dahliae. The interacting proteins of GhXB32A and GhXB32D were functionally enriched in response to abiotic and/or biotic stresses, and photosynthesis. XB3 family genes are potential stress resistance genes for cotton improvement. • 32 putative XB3 family genes were identified in G. hirsutum, G. arboreum, and G. raimondii. • Most of GhXB3s were down-regulated by cold stress, but up-regulated by heat, salt, PEG, Verticillium dahliae , ethylene; some of them were up-regulated by SA or MeJA. • Silencing GhXB32A and GhXB32D significantly enhanced resistance to Verticillium wilt, whereas silencing GhXB35A(D) or GhXB37A(D) resulted in higher susceptibility to V. dahliae. • GhXB3s expression, VIGS Silencing, and interacting protein analyses indicate their roles in abiotic and/or biotic stresses. [ABSTRACT FROM AUTHOR]