5-7-dihydroxy-6-methoxy-2-phenylchromen-4-one and Liver-Cirrhosis

Relevant studies have recognized the important role of hepatic stellate cell (HSC) senescence in anti-liver fibrosis. Cellular senescence is believed to be regulated by the cGAS-STING signaling pathway. However, underlying exact mechanisms of cGAS-STING pathway in hepatic stellate cell senescence are still unclear. Here, we found that Oroxylin A could promote senescence in HSC by activating the cGAS-STING pathway. Moreover, activation of the cGAS-STING pathway was dependent on DNMT3A downregulation, which suppressed cGAS gene DNA methylation. Interestingly, the attenuation of DNMT activity relied on the reduction of methyl donor SAM level. Noteworthy, the downregulation of SAM levels implied the imbalance of methionine cycle metabolism, and MAT2A was considered to be an important regulatory enzyme in metabolic processes. In vivo experiments also indicated that Oroxylin A induced senescence of HSCs in mice with liver fibrosis, and DNMT3A overexpression partly offset this effect. In conclusion, we discovered that Oroxylin A prevented the methylation of the cGAS gene by preventing the production of methionine metabolites, which promoted the senescence of HSCs. This finding offers a fresh hypothesis for further research into the anti-liver fibrosis mechanism of natural medicines.

Topics: Animals; Cellular Senescence; DNA; DNA Methylation; Hepatic Stellate Cells; Liver Cirrhosis; Methionine; Mice; Nucleotidyltransferases

In recent study, the pathological mechanism of liver fibrosis has been associated with hepatic stellate cell (HSC) senescence. Targeted induction of HSC senescence is considered as a new strategy to remove activated HSC. Nevertheless, little is known about the role of ferritinophagy in cell senescence. In this study, we reported that Oroxylin A from Scutellaria baicalensis Georgi can regulate HSC senescence induced by ferritinophagy through the cGAS-STING pathway to reduce liver fibrosis. We first found that Oroxylin A treatment alleviated the pathological changes of liver fibrosis, reduced collagen deposition, and significantly inhibited liver fibrosis. Interestingly, Oroxylin A treatment can activate HSC ferritinophagy and further induce HSC senescence. It is noteworthy that ferritinophagy is mediated by nuclear receptor coactivator 4 (NCOA4), an important selective mediator for ferritin degradation. NCOA4 siRNA causes Oroxylin A to reduce the degree of telomerase activity in HSCs and induce the expression of senescence markers, such as SA-β-Gal and related marker proteins. Importantly, the cGAS-STING pathway is crucial to the activation of HSC ferritinophagy by Oroxylin A. Specifically, Oroxylin A can promote the secretion of cytokines like IFN-β by the cGAS-STING pathway to regulate ferritinophagy. cGAS siRNA resulted in a dose-dependent decrease in the expression of NCOA4, a significant reduction in the expression level of autophagy-related phenotype, and a decrease in the content of ROS and iron ions in HSCs. In conclusion, we identified the new role of ferritinophagy and the GAS-STING pathway in Oroxylin A -mediated anti-hepatic fibrosis.

Topics: Cellular Senescence; Hepatic Stellate Cells; Humans; Liver Cirrhosis; Nucleotidyltransferases; RNA, Small Interfering; Signal Transduction

More and more evidence showed that autophagy is an inflammation-related defense mechanism against a variety of diseases including liver fibrosis. However, the essential mechanisms remain poorly understood. In this study, we sought to elucidate the impact of Oroxylin A on autophagy and further to identify the potential mechanism of its anti-inflammatory activity. We found that Oroxylin A played a critical role in controlling inflammation in murine liver fibrosis. Moreover, Oroxylin A could inhibit the secretion of pro-inflammatory cytokines in activated hepatic stellate cell (HSCs). We previously reported that Oroxylin A can induce autophagy to alleviate the pathological changes of liver fibrosis and the activation of HSC. Here we further revealed that the inhibition of the PI3K/Akt/mTOR signaling was required for Oroxylin A to induce autophagy activation, which may be the underlying mechanism of the anti-inflammatory activity of Oroxylin A. Interestingly, mTOR overexpression completely impaired the Oroxylin A-mediated autophagy activation, and in turn, damaged the anti-inflammatory activity. Importantly, Oroxylin A inhibited PI3K/Akt/mTOR signaling by scavenging reactive oxygen species (ROS). ROS accumulation by buthionine sulfoximine (BSO) could abrogate the Oroxylin A-mediated ROS elimination, the inhibition of PI3K/Akt/mTOR signaling, and anti-inflammatory activities. Overall, our results provided reliable evidence for the molecular mechanism of Oroxylin A-mediated anti-fibrosis activity, and also identified a new target for drug therapy of liver fibrosis.

Topics: Animals; Anti-Inflammatory Agents; Carbon Tetrachloride; Cells, Cultured; Cytokines; Flavonoids; Hepatic Stellate Cells; Liver Cirrhosis; Male; Mice, Inbred C57BL; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction; TOR Serine-Threonine Kinases

Hepatic stellate cell (HSC) activation plays an indispensable role in hepatic fibrosis. Inducing apoptosis of activated HSCs can attenuate or reverse fibrogenesis. In this study, we initially found that oroxylin A (OA) protected CCl

Topics: Animals; Apoptosis; Carbon Tetrachloride; Cell Cycle Checkpoints; Cell Line; Cell Proliferation; Cinnamates; Collagen; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Eukaryotic Initiation Factor-2; Flavonoids; Hepatic Stellate Cells; Inflammation; Liver; Liver Cirrhosis; Male; Mice; Mice, Inbred ICR; Signal Transduction; Thiourea

Proliferation and differentiation of hepatic stellate cells (HSCs) are the most noticeable events in hepatic fibrosis, in which the loss of lipid droplets (LDs) is the most important feature. However, the complex mechanisms of LD disappearance have not been fully elucidated. In the current study, we investigated whether oroxylin A has the pharmacological activity of reversing LDs in activated HSCs, and further examined its potential molecular mechanisms. Using genetic, pharmacological, and molecular biological measure, we found that LD content significantly decreased during HSC activation, whereas oroxylin A markedly reversed LD content in activated HSCs. Interestingly, oroxylin A treatment observably decreased the expression of adipose triglyceride lipase (ATGL) without large differences in classical LD synthesis pathway, LD-related transcription factors, and autophagy pathway. ATGL overexpression could completely impair the effect of oroxylin A on reversing LD content. Importantly, reactive oxygen species (ROS) signaling pathway mediated oroxylin A-induced ATGL downregulation and LD revision in activated HSCs. ROS specific stimulant buthionine sulfoximine (BSO) could dramatically diminish the antioxidant effect of oroxylin A, and in turn, abolish reversal effect of oroxylin A on LD content. Conversely, ROS specific scavenger N-acetyl cystenine (NAC) can significantly enhance the pharmacological effect of oroxylin A on LD revision. Taken together, our study reveals the important molecular mechanism of anti-fibrosis effect of oroxylin A, and also suggests that ROS-ATGL pathway is a potential target for reversing LDs.

Topics: Animals; Autophagy; Cells, Cultured; Down-Regulation; Flavonoids; Gene Expression Regulation, Enzymologic; Hepatic Stellate Cells; Lipase; Lipid Droplets; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Signal Transduction

Contraction of hepatic stellate cells (HSCs) plays an important role in the pathogenesis of liver fibrosis by regulating sinusoidal blood flow and extracellular matrix remodeling. Here, we investigated how HSC contraction was affected by the natural compound oroxylin A, and elucidated the underlying mechanism.. Cell contraction and glycolysis were examined in cultured human HSCs and mouse liver fibrosis model upon oroxylin A intervention using diversified cellular and molecular assays, as well as genetic approaches.. Oroxylin A limited HSC contraction associated with inhibiting myosin light chain 2 phosphorylation. Oroxylin A blocked aerobic glycolysis in HSCs evidenced by reduction in glucose uptake and consumption and lactate production. Oroxylin A also decreased extracellular acidification rate and inhibited the expression and activity of glycolysis rate-limiting enzymes (hexose kinase 2, phosphofructokinase 1 and pyruvate kinas type M2) in HSCs. Then, we identified that oroxylin A blockade of aerobic glycolysis contributed to inhibition of HSC contraction. Furthermore, oroxylin A inhibited the expression and activity of lactate dehydrogenase-A (LDH-A) in HSCs, which was required for oroxylin A blockade of glycolysis and suppression of contraction. Oral administration of oroxylin A at 40 mg/kg reduced liver injury and fibrosis, and inhibited HSC glycolysis and contraction in mice with carbon tetrachloride-induced hepatic fibrosis. However, adenovirus-mediated overexpression of LDH-A significantly counteracted the oroxylin A's effects in fibrotic mice.. Blockade of aerobic glycolysis by oroxylin A via inhibition of LDH-A reduced HSC contraction and attenuated liver fibrosis, suggesting LDH-A as a promising target for intervention of hepatic fibrosis.

Topics: Aerobiosis; Cell Line; Flavonoids; Glycolysis; Hepatic Stellate Cells; Humans; L-Lactate Dehydrogenase; Liver; Liver Cirrhosis

Angiogenesis of liver sinusoidal endothelial cells (LSECs) accompanies with hypoxia in liver fibrosis and they are of mutual promotion, which has raised wide concern. Here we established murine model of liver fibrosis and found that oroxylin A (40 mg/kg) could ameliorate angiogenesis in liver fibrosis may related to hypoxia inducible factor 1α (HIF-1α). The underlying mechanism was further investigated by isolating and culturing murine primary LSECs. Hypoxia induced vascular endothelial growth factor A (VEGF-A), angiopoietin 2 (Ang-2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) elevated in LSECs were reduced by oroxylin A or acriflavine (ACF, an HIF-1α inhibitor), indicating HIF-1α involved the angiogenesis of LSECs. Additionally, interference with Yes-associated protein (YAP) significant downregulated the protein expression of HIF-1α and VEGF-A, while YAP plasmid exhibited an opposite effect. We next found that oroxylin A inhibited hypoxia-induced nuclear translocation of YAP, which may influence the accumulation of HIF-1α and subsequently decrease transcription of downstream target gene including VEGF-A and Ang-2, thereby exerting an anti-angiogenic activity.

Topics: Adaptor Proteins, Signal Transducing; Angiopoietin-2; Animals; Carbon Tetrachloride; Cell Cycle Proteins; Cells, Cultured; Disease Models, Animal; Endothelial Cells; Flavonoids; Gene Expression Regulation; Hypoxia-Inducible Factor 1, alpha Subunit; Liver Cirrhosis; Male; Mice; Neovascularization, Pathologic; Phosphoproteins; Signal Transduction; Vascular Endothelial Growth Factor A; YAP-Signaling Proteins