Autophagy is reported to be involved in the formation of skin hypertrophic scar (HTS). However, the role of autophagy in the process of fibrosis remains unclear, therefore an improved understanding of the molecular mechanisms associated with autophagy may accelerate the development of effective therapeutic strategies against HTS. The present study evaluated the roles of autophagy mediated by transcription factor EB (TFEB), a pivotal regulator of lysosome biogenesis and autophagy, in transforming growth factor-β1 (TGF-β1)-induced fibroblast differentiation and collagen production. Fibroblasts were treated with TGF-β1, TGF-β1 + tauroursodeoxycholic acid (TUDCA) or TGF-β1 + TFEB-small interfering RNA (siRNA). TGF-β1 induced phenotypic transformation of fibro-blasts, as well as collagen synthesis and secretion in fibroblasts in a dose-dependent manner. Western blotting and immuno-fluorescence analyses demonstrated that TGF-β1 upregulated the expression of autophagy-related proteins through the endoplasmic reticulum (ER) stress pathway, whereas TUDCA reversed TGF-β1-induced changes. Reverse transcription-quantitative PCR (RT-qPCR), western blotting and RFP-GFP-LC3 double fluorescence analyses demonstrated that knockdown of TFEB by TFEB-siRNA decreased autophagic flux, upregulated the expression of proteins involved in the apoptotic pathway, such as phosphorylated-α subunit of eukaryotic initiation factor 2, C/EBP homologous protein and cysteinyl aspartate specific proteinase 3, and also downregulated the expression of α-smooth muscle actin and collagen I (COL I) in fibroblasts. Immunofluorescence confocal analyses and enzyme-linked immunosorbent assay indicated that TGF-β1 increased the colocalization of COL I with lysosomal-associated membrane protein 1 and Ras-related protein Rab-8A, a marker of secretory vesicles, in fibroblasts, as well as the secretion of pro-COL Iα1 in culture supernatants. Meanwhile, these effects were abolished by TFEB knockdown. The present results suggested that autophagy reduced ER stress, decreased cell apoptosis and maintained fibroblast activation not only through degradation of misfolded or unfolded proteins, but also through promotion of COL I release from the autolysosome to the extracellular environment.
Objectives: Depletion of early growth response factor-1 (Egr-1) by a DNA enzyme, ED5, inhibits neointimal hyperplasia (NH) following vascular injury by an unknown mechanism. The aim of this study was to characterize the effects of ED5 in a rat carotid injury model in order to elucidate the mechanism by which ED5 inhibits NH. Methods: ED5 was transfected into the arterial wall of Wistar rats using FuGENE6 transfection reagent following artery balloon injury. Hematoxylin and eosin staining, immunohistochemistry, real-time reverse transcription polymerase chain reaction and Western blotting analysis were used to characterize the response to ED5. Results: NH decreased significantly in the ED5- plus FuGENE6-treated rats (p < 0.05) compared with the control groups, and this was accompanied by a reduced inflammatory response. Egr-1 mRNA and protein levels were significantly decreased in the ED5-treated group, as expected. The decrease in Egr-1 was accompanied by decreases in the mRNA and protein levels of PDGF-BB, Cyclin D1, CDK4, MCP-1, and ICAM-1 (p < 0.05). Conclusions: Transfection of the Egr-1-specific synthetic DNA enzyme ED5 significantly reduced NH after injury in rats, at least in part, as a result of decreased expression of downstream proliferative genes such as PDGF-BB, Cyclin D1, CDK4, and the inflammatory factors MCP-1 and ICAM-1.
Fulminant hepatitis (FH) is a life-threatening disease with partially understood pathogenesis. It has been demonstrated that myeloid-derived suppressor cells (MDSCs) are recruited into the liver during this process, and their augmented accumulation by various strategies protects against liver injury. However, the underlying mechanism(s) remain elusive. Receptor for activated C kinase 1 (RACK1), a multi-functional scaffold protein, is highly expressed in normal liver and has been implicated in liver physiology and diseases, but the in vivo role of hepatic RACK1 in FH remains unknown. Methods: Survival curves and liver damage were monitored to investigate the in vivo role of hepatic RACK1 in FH. The liver microenvironment was explored by microarray-based transcriptome analysis, flow cytometry, immunoblotting, and immunohistochemistry. MDSCs were identified with phenotypic and functional characteristics. Functional antibodies were used to target MDSCs. Co-culture techniques were used to study the underlying mechanism(s) of protection. The interaction of RACK1 with histone deacetylase 1 (HDAC1) and the consequent effects on HDAC1 ubiquitination were analyzed. Ectopic expression of HDAC1 with recombinant adeno-associated virus serotype 8 was conducted to confirm the role of HDAC1 in the protective effects of hepatic RACK1 deficiency against FH. Post-translational modifications of RACK1 were also investigated during the induction of FH. Results: Liver-specific RACK1 deficiency rendered mice resistant to FH. RACK1-deficient livers exhibited high basal levels of chemokine (C-X-C motif) ligand 1 (CXCL1) and S100 calcium-binding protein A9 (S100A9), associated with MDSC accumulation under steady-state conditions. Targeting MDSCs with an antibody against either Gr1 or DR5 abrogated the protective effects of liver-specific RACK1 deficiency. Accumulated MDSCs inhibited inflammatory cytokine production from macrophages and enhanced IκB kinase (IKK)/NF-κB pathway activation in hepatocytes. Further investigation revealed that RACK1 maintained HDAC1 protein level in hepatocytes by direct binding, thereby controlling histone H3K9 and H3K27 acetylation at the Cxcl1 and S100a9 promoters. Ectopic expression of HDAC1 in livers with RACK1 deficiency partially reversed the augmented Cxcl1/S100a9 → MDSCs → IKK/NF-κB axis. During FH induction, RACK1 was phosphorylated at serine 110, enhancing its binding to ubiquitin-conjugating enzyme E2T and promoting its ubiquitination and degradation. Conclusion: Liver-specific RACK1 deficiency protects against FH through accelerated HDAC1 degradation and the consequent CXCL1/S100A9 upregulation and MDSC accumulation.
Background: Coronary pressure-derived fractional flow reverse (FFR) is the standard of the functional assessment of lesion severity. In spite of its strengths in determining ischemia-related coronary stenosis, the invasive operation involved still limits its clinical application. Coronary computed tomography angiographyderived FFR (CCTA-FFR) or computed tomography-derived FFR (CT-FFR) has been indicated as an effective and non-invasive index to evaluate lesion-specific ischemia. However, its diagnostic performance, especially in patients with different severity of coronary stenosis, remains unknown. The current research attempted to demonstrate this problem and provided the foundation for extensive clinical application of CCTA-FFR. Methods:The design of this study was a diagnostic test. A total of 97 vessels from 91 patients who performed CCTA and coronary angiography (CAG) during a hospitalization collected from two research centers were included in this study. CCTA-FFR and FFR were obtained by CCTA and CAG separately.The Gensini score was calculated according to the CAG in each patient. FFR was indicated as the golden diagnosis of lesion-specific ischemia with a cut-off value of 0.80, which was consistent with most contemporary studies. A receiver-operating characteristic (ROC) curve, simple linear analysis, and Bland-Altman plot were performed to determine the diagnostic performance of CCTA-FFR.Results: CCTA-FFR was well correlated with invasive FFR (R 2 =0.745, P<0.001) and the area under the curve (AUC) was 0.976. The sensitivity was 94.6% and the specificity was 95.1%. The mean difference between FFR and CT-FFR was 0.011, and the 95% confidence interval was −0.173 to 0.196. The AUCs were 0.989 and 0.928 in the low and high Gensini groups, respectively, and there was no significant difference in the diagnostic accuracies between these two groups (Z=0.003, P>0.500). CT-FFR still exhibited a good correlation with FFR (R 2 =0.713, P<0.001 in the low Gensini group and R 2 =0.743, P<0.001 in the high Gensini group). The systematic differences were calculated, and the mean difference between FFR and CT-FFR was −0.005 and 0.025, respectively, in these two groups.Conclusions: CCTA-FFR exhibited good diagnostic performance in patients with different Gensini score levels. Our results indicate that CCTA-FFR could be an effective tool to screen lesion-specific ischemia in patients with coronary artery disease.
Ginseng (Panax ginseng C.A.Mey.) is the dry root and rhizome of the Araliaceae ginseng plant. It has always been used as a tonic in China for strengthening the body. Cardiovascular disease is still the main cause of death in the world. Some studies have shown that the functional components of ginseng can regulate the pathological process of various cardiovascular diseases through different mechanisms, and its formulation also plays an irreplaceable role in the clinical treatment of cardiovascular diseases. Therefore, this paper elaborates the current pharmacological effects of ginseng functional components in treating cardiovascular diseases, summarizes the adverse reactions of ginseng, and sorts out the Chinese patent medicines containing ginseng formula which can treat cardiovascular diseases.
Objective To investigate the role of IGF1 and SIRT1 pathways in protection of hydrogen peroxide (H2O2)-induced aging in H9c2 rat cardiomyocyte cells by testosterone. Methods The cells were treated with testosterone or up- or down-regulated for the IGF1 and SIRT1 genes and assessed for apoptosis, aging and expression of relevant genes. Results Aging was induced and the expression of SIRT1 and IGF1 was down-regulated after H2O2 treatment in H9c2 cells. The aging was attenuated in a dose-dependent manner after the cells were exposed to testosterone. Down-regulation of SIRT1 and IGF1expression was offset in the H2O2-treated cells co-treated with testosterone. Up- or down-regulation of IGF1 significantly reduced or increased senescence-associated beta-galactosidase (SA-β-gal) cells and the ROS level, respectively. In addition, SIRT1 expression was regulated by IGF1 expression. Down- or up-regulation of SIRT1 significantly decreased or increased the IGF1 levels, respectively. Furthermore, after IGF1 and SIRT1 knockdown, testosterone did not protect the cells from senescence. Testosterone, and overexpression of IGF1 and SIRT1 also up-regulated the expression of the fetal genes SERCA2 and MYH6 and down-regulated the expression of the ACTA1 and MYH7 genes. Conclusions Our data indicate that testosterone can attenuate cardiomyocyte aging induced by H2O2 and up-regulate SIRT1 and IGF1. The IGF1and SIRT1 pathway may be new targets to treat heart aging and heart failure.
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