There have been considerable recent advances towards a better understanding of the complex cellular and molecular network underlying liver fibrogenesis.Recent data indicate that the termination of fibrogenic processes...There have been considerable recent advances towards a better understanding of the complex cellular and molecular network underlying liver fibrogenesis.Recent data indicate that the termination of fibrogenic processes and the restoration of deficient fibrolytic pathways may allow the reversal of advanced fibrosis and even cirrhosis.Therefore,efforts have been made to better clarify the cellular and molecular mechanisms that are involved in liver fibrosis.Activation of hepatic stellate cells(HSCs)remains a central event in fibrosis,complemented by other sources of matrix-producing cells,including portal fibroblasts,fibrocytes and bone marrow-derived myofibroblasts.These cells converge in a complex interaction with neighboring cells to provoke scarring in response to persistent injury.Defining the interaction of different cell types,revealing the effects of cytokines on these cells and characterizing the regulatory mechanisms that control gene expression in activated HSCs will enable the discovery of new therapeutic targets.Moreover,the characterization of different pathways associated with different etiologies aid in the development of disease-specific therapies.This article outlines recent advances regarding the cellular and molecular mechanisms involved in liver fibrosis that may be translated into future therapies.The pathogenesis of liver fibrosis associated with alcoholic liver disease,non-alcoholic fatty liver disease and viral hepatitis are also discussed to emphasize the various mechanisms involved in liver fibrosis.展开更多
AIM： To investigate whether Notch signaling is involved in liver fibrosis by regulating the activation of hepatic stellate cells （HSCs）.METHODS： Immunohistochemistry was used to detect the expression of Notch3 in ...AIM： To investigate whether Notch signaling is involved in liver fibrosis by regulating the activation of hepatic stellate cells （HSCs）.METHODS： Immunohistochemistry was used to detect the expression of Notch3 in fibrotic liver tissues of patients with chronic active hepatitis. The expression of Notch3 in HSC-T6 cells treated or not with transforming growth factor （TGF）-β1 was analyzed by iramunofluorescence staining, The expression of Notch3 and myofibroblastic marker （z-smooth muscle actin （（z-SMA） and collagen 1 in HSC-T6 cells transfected with pcDNA3. I-N3ICD or control vector were detected by Western blotting and immunofluorescence staining. Moreover, effects of Notch3 knockdown in HSC-T6 by Notch3 siRNA were investigated by Western blotting and immunofluorescence staining.RESULTS： The expression of Notch3 was significantly up-regulated in fibrotic liver tissues of patients withchronic active hepatitis, but not detected in normal liver tissues. Active Notch signaling was found in HSC-T6 cells. TGF-β1 treatment led to up-regulation of Notch3 expression in HSC-T6 cells, and over-expression of Notch3 increased the expression of α-SMA and collagen I in HSC-T6 without TGF-β1 treatment. Interestingly, transient knockdown of Notch3 decreased the expression of myofibroblastic marker and antagonized TGF-β1 induced expression of α-SMA and collagen I in HSC-T6.CONCLUSION： Notch3 may regulate the activation of HSCs, and the selective interruption of Notch3 may provide an anti -fibrotic strategy in hepatic fibrosis.展开更多
Chronic hyperglycemia is one of the main characteristics of diabetes. Persistent exposure to elevated glucose levels has been recognized as one of the major causal factors of diabetic complications. In pathologies, li...Chronic hyperglycemia is one of the main characteristics of diabetes. Persistent exposure to elevated glucose levels has been recognized as one of the major causal factors of diabetic complications. In pathologies, like type 2 diabetes mellitus(T2DM), mechanical and biochemical stimuli activate profibrotic signaling cascades resulting in myocardial fibrosis and subsequent impaired cardiac performance due to ventricular stiffness. High levels of glucose nonenzymatically react with long-lived proteins, such as collagen, to form advanced glycation end products(AGEs). AGE-modified collagen increase matrix stiffness making it resistant to hydrolytic turnover, resulting in an accumulation of extracellular matrix(ECM) proteins. AGEs account for many of the diabetic cardiovascular complications through their engagement of the receptor for AGE(RAGE). AGE/RAGE activation stimulates the secretion of numerous profibrotic growth factors, promotes increased collagen deposition leading to tissue fibrosis, as well as increased RAGE expression. To date, the AGE/RAGE cascade is not fully understood. In this review, we willdiscuss one of the major fibrotic signaling pathways, the AGE/RAGE signaling cascade, as well as propose an alternate pathway via Rap1 a that may offer insight into cardiovascular ECM remodeling in T2 DM. In a series of studies, we demonstrate a role for Rap1 a in the regulation of fibrosis and myofibroblast differentiation in isolated diabetic and non-diabetic fibroblasts. While these studies are still in a preliminary stage, inhibiting Rap1 a protein expression appears to down-regulate the molecular switch used to activate the ζ isotype of protein kinase C thereby promote AGE/RAGE-mediated fibrosis.展开更多
Astragalus mongholicus （AM） derived from the dry root ofAstragalus membranaceus Bge. var. mongolicus （Bge.） Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of...Astragalus mongholicus （AM） derived from the dry root ofAstragalus membranaceus Bge. var. mongolicus （Bge.） Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction （UUO）. We divided 48 Sprague-Dawley rats randomly into 4 groups： sham-operated group （Sham）, untreated UUO group, AM-treated （10 g/（kg.d）） UUO group, and losartan-treated （20 mg/（kg.d）） UUO group as positive control. Haematoxylin ＆ eosin （HE） and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin （FN）, type I collagen （coil）, hepatocyte growth factor （HGF）, transforming growth factor-β1 （TGF-β1）, and eL-smooth muscle actin （α-SMA） were analyzed by real-time polymerase chain reaction （PCR）, immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and coil from UUO by reducing the expressions of TGF-β1 and α-SMA （P〈0.05）, whereas HGF increased greatly with AM treatment （P〈0.05）. Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition ofmyofibroblast activation, inducing of HGF and reducing of TGF-β1 expression.展开更多
文摘There have been considerable recent advances towards a better understanding of the complex cellular and molecular network underlying liver fibrogenesis.Recent data indicate that the termination of fibrogenic processes and the restoration of deficient fibrolytic pathways may allow the reversal of advanced fibrosis and even cirrhosis.Therefore,efforts have been made to better clarify the cellular and molecular mechanisms that are involved in liver fibrosis.Activation of hepatic stellate cells(HSCs)remains a central event in fibrosis,complemented by other sources of matrix-producing cells,including portal fibroblasts,fibrocytes and bone marrow-derived myofibroblasts.These cells converge in a complex interaction with neighboring cells to provoke scarring in response to persistent injury.Defining the interaction of different cell types,revealing the effects of cytokines on these cells and characterizing the regulatory mechanisms that control gene expression in activated HSCs will enable the discovery of new therapeutic targets.Moreover,the characterization of different pathways associated with different etiologies aid in the development of disease-specific therapies.This article outlines recent advances regarding the cellular and molecular mechanisms involved in liver fibrosis that may be translated into future therapies.The pathogenesis of liver fibrosis associated with alcoholic liver disease,non-alcoholic fatty liver disease and viral hepatitis are also discussed to emphasize the various mechanisms involved in liver fibrosis.
基金grants from the National Natural Science Foundation of China (No.81570623)Science Funds for Distinguished Young Scholars of Anhui Province, China (No.1608085J07)。
基金Supported by The National Natural Science Foundation ofChina,No. 30900663
文摘AIM： To investigate whether Notch signaling is involved in liver fibrosis by regulating the activation of hepatic stellate cells （HSCs）.METHODS： Immunohistochemistry was used to detect the expression of Notch3 in fibrotic liver tissues of patients with chronic active hepatitis. The expression of Notch3 in HSC-T6 cells treated or not with transforming growth factor （TGF）-β1 was analyzed by iramunofluorescence staining, The expression of Notch3 and myofibroblastic marker （z-smooth muscle actin （（z-SMA） and collagen 1 in HSC-T6 cells transfected with pcDNA3. I-N3ICD or control vector were detected by Western blotting and immunofluorescence staining. Moreover, effects of Notch3 knockdown in HSC-T6 by Notch3 siRNA were investigated by Western blotting and immunofluorescence staining.RESULTS： The expression of Notch3 was significantly up-regulated in fibrotic liver tissues of patients withchronic active hepatitis, but not detected in normal liver tissues. Active Notch signaling was found in HSC-T6 cells. TGF-β1 treatment led to up-regulation of Notch3 expression in HSC-T6 cells, and over-expression of Notch3 increased the expression of α-SMA and collagen I in HSC-T6 without TGF-β1 treatment. Interestingly, transient knockdown of Notch3 decreased the expression of myofibroblastic marker and antagonized TGF-β1 induced expression of α-SMA and collagen I in HSC-T6.CONCLUSION： Notch3 may regulate the activation of HSCs, and the selective interruption of Notch3 may provide an anti -fibrotic strategy in hepatic fibrosis.
基金Supported by Grants from the American Heart Association,No.SDG5310006(JAS)and No.BGIA4150122(JAS)
文摘Chronic hyperglycemia is one of the main characteristics of diabetes. Persistent exposure to elevated glucose levels has been recognized as one of the major causal factors of diabetic complications. In pathologies, like type 2 diabetes mellitus(T2DM), mechanical and biochemical stimuli activate profibrotic signaling cascades resulting in myocardial fibrosis and subsequent impaired cardiac performance due to ventricular stiffness. High levels of glucose nonenzymatically react with long-lived proteins, such as collagen, to form advanced glycation end products(AGEs). AGE-modified collagen increase matrix stiffness making it resistant to hydrolytic turnover, resulting in an accumulation of extracellular matrix(ECM) proteins. AGEs account for many of the diabetic cardiovascular complications through their engagement of the receptor for AGE(RAGE). AGE/RAGE activation stimulates the secretion of numerous profibrotic growth factors, promotes increased collagen deposition leading to tissue fibrosis, as well as increased RAGE expression. To date, the AGE/RAGE cascade is not fully understood. In this review, we willdiscuss one of the major fibrotic signaling pathways, the AGE/RAGE signaling cascade, as well as propose an alternate pathway via Rap1 a that may offer insight into cardiovascular ECM remodeling in T2 DM. In a series of studies, we demonstrate a role for Rap1 a in the regulation of fibrosis and myofibroblast differentiation in isolated diabetic and non-diabetic fibroblasts. While these studies are still in a preliminary stage, inhibiting Rap1 a protein expression appears to down-regulate the molecular switch used to activate the ζ isotype of protein kinase C thereby promote AGE/RAGE-mediated fibrosis.
基金(No.30170437) supported by the National Natural Science Foundation of China
文摘Astragalus mongholicus （AM） derived from the dry root ofAstragalus membranaceus Bge. var. mongolicus （Bge.） Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction （UUO）. We divided 48 Sprague-Dawley rats randomly into 4 groups： sham-operated group （Sham）, untreated UUO group, AM-treated （10 g/（kg.d）） UUO group, and losartan-treated （20 mg/（kg.d）） UUO group as positive control. Haematoxylin ＆ eosin （HE） and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin （FN）, type I collagen （coil）, hepatocyte growth factor （HGF）, transforming growth factor-β1 （TGF-β1）, and eL-smooth muscle actin （α-SMA） were analyzed by real-time polymerase chain reaction （PCR）, immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and coil from UUO by reducing the expressions of TGF-β1 and α-SMA （P〈0.05）, whereas HGF increased greatly with AM treatment （P〈0.05）. Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition ofmyofibroblast activation, inducing of HGF and reducing of TGF-β1 expression.
