Chronic liver inflammation drives hepatic fibrosis,and current immunosuppressive,anti-inflammatory,and anti-viral therapies can weaken this driver.Hepatic fibrosis is reversed,stabilized,or prevented in 57%-79%of pati...Chronic liver inflammation drives hepatic fibrosis,and current immunosuppressive,anti-inflammatory,and anti-viral therapies can weaken this driver.Hepatic fibrosis is reversed,stabilized,or prevented in 57%-79%of patients by conventional treatment regimens,mainly by their anti-inflammatory actions.Responses,however,are commonly incomplete and inconsistently achieved.The fibrotic mechanisms associated with liver inflammation have been clarified,and anti-fibrotic agents promise to improve outcomes as adjunctive therapies.Hepatitis C virus and immune-mediated responses can activate hepatic stellate cells by increasing oxidative stress within hepatocytes.Angiotensin can be synthesized by activated hepatic stellate cells and promote the production of reactive oxygen species.Anti-oxidants(Nacetylcysteine,S-adenosyl-L-methionine,and vitamin E)and angiotensin inhibitors(losartin)have had antifibrotic actions in preliminary human studies,and they may emerge as supplemental therapies.Anti-fibrotic agents presage a new era of supplemental treatment for chronic liver disease.展开更多
At present chronic liver disease(CLD),the third commonest cause of premature death in the United Kingdom is detected late,when interventions are ineffective,resulting in considerable morbidity and mortality.Injury to ...At present chronic liver disease(CLD),the third commonest cause of premature death in the United Kingdom is detected late,when interventions are ineffective,resulting in considerable morbidity and mortality.Injury to the liver,the largest solid organ in the body,leads to a cascade of inflammatory events.Chronic inflammation leads to the activation of hepatic stellate cells that undergo transdifferentiation to become myofibroblasts,the main extra-cellular matrix producing cells in the liver;over time increased extra-cellular matrix production results in the formation of liver fibrosis.Although fibrogenesis may be viewed as having evolved as a“wound healing”process that preserves tissue integrity,sustained chronic fibrosis can become pathogenic culminating in CLD,cirrhosis and its associated complications.As the reference standard for detecting liver fibrosis,liver biopsy,is invasive and has an associated morbidity,the diagnostic assessment of CLD by non-invasive testing is attractive.Accordingly,in this review the mechanisms by which liver inflammation and fibrosis develop in chronic liver diseases are explored to identify appropriate and meaningful diagnostic targets for clinical practice.Due to differing disease prevalence and treatment efficacy,disease specific diagnostic targets are required to optimally manage individual CLDs such as non-alcoholic fatty liver disease and chronic hepatitis C infection.To facilitate this,a review of the pathogenesis of both conditions is also conducted.Finally,the evidence for hepatic fibrosis regression and the mechanisms by which this occurs are discussed,including the current use of antifibrotic therapy.展开更多
The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal...The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal stem cells （MSCs） has gained much attention. However, the underlying cellular mechanisms of MSC therapy are still not fully understood. Although paracrine effects of MSCs on residual cardiomyocytes have been discussed, the amelioration of fibrosis was rarely studied as the hostile environment cannot support the survival of most cell populations and impairs the diffusion of soluble factors. Here in order to decipher the potential mecha- nism of MSC therapy for cardiac fibrosis, we investi- gated the interplay between MSCs and cardiac myofibroblasts （mFBs） using interactive co-culture method, with comparison to paracrine approaches, namely treatment by MSC conditioned medium and gap co-culture method. Various fibrotic features of mFBs were analyzed and the most prominent anti-fibrosis effects were always obtained using direct co-culture that allowed cell-to-cell contacts. Hepatocyte growth factor （HGF）, a well-known anti-fibrosis factor, was demonstrated to be a major contributor for MSCs＇ anti-fibrosisfunction. Moreover, physical contacts and tube-like structures between MSCs and mFBs were observed by live cell imaging and TEM which demonstrate the direct cellular interactions.展开更多
文摘Chronic liver inflammation drives hepatic fibrosis,and current immunosuppressive,anti-inflammatory,and anti-viral therapies can weaken this driver.Hepatic fibrosis is reversed,stabilized,or prevented in 57%-79%of patients by conventional treatment regimens,mainly by their anti-inflammatory actions.Responses,however,are commonly incomplete and inconsistently achieved.The fibrotic mechanisms associated with liver inflammation have been clarified,and anti-fibrotic agents promise to improve outcomes as adjunctive therapies.Hepatitis C virus and immune-mediated responses can activate hepatic stellate cells by increasing oxidative stress within hepatocytes.Angiotensin can be synthesized by activated hepatic stellate cells and promote the production of reactive oxygen species.Anti-oxidants(Nacetylcysteine,S-adenosyl-L-methionine,and vitamin E)and angiotensin inhibitors(losartin)have had antifibrotic actions in preliminary human studies,and they may emerge as supplemental therapies.Anti-fibrotic agents presage a new era of supplemental treatment for chronic liver disease.
文摘At present chronic liver disease(CLD),the third commonest cause of premature death in the United Kingdom is detected late,when interventions are ineffective,resulting in considerable morbidity and mortality.Injury to the liver,the largest solid organ in the body,leads to a cascade of inflammatory events.Chronic inflammation leads to the activation of hepatic stellate cells that undergo transdifferentiation to become myofibroblasts,the main extra-cellular matrix producing cells in the liver;over time increased extra-cellular matrix production results in the formation of liver fibrosis.Although fibrogenesis may be viewed as having evolved as a“wound healing”process that preserves tissue integrity,sustained chronic fibrosis can become pathogenic culminating in CLD,cirrhosis and its associated complications.As the reference standard for detecting liver fibrosis,liver biopsy,is invasive and has an associated morbidity,the diagnostic assessment of CLD by non-invasive testing is attractive.Accordingly,in this review the mechanisms by which liver inflammation and fibrosis develop in chronic liver diseases are explored to identify appropriate and meaningful diagnostic targets for clinical practice.Due to differing disease prevalence and treatment efficacy,disease specific diagnostic targets are required to optimally manage individual CLDs such as non-alcoholic fatty liver disease and chronic hepatitis C infection.To facilitate this,a review of the pathogenesis of both conditions is also conducted.Finally,the evidence for hepatic fibrosis regression and the mechanisms by which this occurs are discussed,including the current use of antifibrotic therapy.
文摘The onset of cardiac fibrosis post myocardial infarction greatly impairs the function of heart. Recent advances of cell transplantation showed great benefits to restore myocardial function, among which the mesenchymal stem cells （MSCs） has gained much attention. However, the underlying cellular mechanisms of MSC therapy are still not fully understood. Although paracrine effects of MSCs on residual cardiomyocytes have been discussed, the amelioration of fibrosis was rarely studied as the hostile environment cannot support the survival of most cell populations and impairs the diffusion of soluble factors. Here in order to decipher the potential mecha- nism of MSC therapy for cardiac fibrosis, we investi- gated the interplay between MSCs and cardiac myofibroblasts （mFBs） using interactive co-culture method, with comparison to paracrine approaches, namely treatment by MSC conditioned medium and gap co-culture method. Various fibrotic features of mFBs were analyzed and the most prominent anti-fibrosis effects were always obtained using direct co-culture that allowed cell-to-cell contacts. Hepatocyte growth factor （HGF）, a well-known anti-fibrosis factor, was demonstrated to be a major contributor for MSCs＇ anti-fibrosisfunction. Moreover, physical contacts and tube-like structures between MSCs and mFBs were observed by live cell imaging and TEM which demonstrate the direct cellular interactions.
