Metabolism regulation of TD26 in hepatocellular carcinoma: mechanistic links and potential clinical implication

Objective:Hepatocellular carcinoma(HCC)is a leading cause of cancer-related deaths worldwide,and HCC cells metabolically distinct from normal hepatocytes.Increased lipogenesis has been reported to play a critical role in HCC progression.This study aims to investigate the underlying mechanism contributing to lipogenesis increase in HCC.

CCL5 deficiency promotes liver repair by improving inflammation resolution and liver regeneration through M2 macrophage polarization

Despite the diverse etiologies of drug-induced liver injury(DILI),innate immunity activation is a common feature involved in DILI progression.However,the involvement of innate immunity regulation in inflammation resolution and liver regeneration in DILI remains obscure.Herein,we identified the chemokine CCL5 as a central mediator of innate immunity regulation in the pathogenesis of DILI.First,we showed that serum and hepatic CCL5 levels are elevated in both DILI patients and an APAP-induced liver injury(AILI)mouse model.Interestingly,both nonparenchymal cells and stressed hepatocytes are cell sources of CCL5 induction in response to liver injury.Functional experiments showed that CCL5 deficiency has no effect on the early phase of AILI but promotes liver repair in the late phase mainly by promoting inflammation resolution and liver regeneration,which are associated with an increased number of hepatic M2 macrophages.Mechanistically,CCL5 can directly activate M1 polarization and impede M2 polarization through the CCR1-and CCR5-mediated activation of the MAPK and NF-κB pathways.We then showed that CCL5 inhibition mediated by either a CCL5-neutralizing antibody or the antagonist Met-CCL5 can greatly alleviate liver injury and improve survival in an AILI mouse model.Our data demonstrate CCL5 induction during DILI,identify CCL5 as a novel innate immunity regulator in macrophage polarization,and suggest that CCL5 blockage is a promising therapeutic strategy for the treatment of DILI.

Mesenchymal stem cells therapy for acute liver failure: Recent advances and future perspectives

Acute liver failure(ALF)is a life-threatening disease characterized by the rapid development of hepatocyte death and a systemic inflammatory response,which leads to high mortality.Despite the prevention of ALF complications,therapeutic effectiveness remains limited because of the rapid disease progression.Thus,there is a need to explore various therapeutic approaches.Currently,the only effective treatment is liver transplantation;However,the lack of donors,surgical complications,immunosuppression,and high medical costs limit its clinical application.Recently,mesenchymal stem cells(MSCs)have been found to exert hepatoprotective effects in ALF through suppression of inflammation,immunoregulation,promotion of mitosis,anti-apoptosis effects,and alleviation of the metabolic and oxidative stress imbalance.In this review,we summarize the advantages and disadvantages of MSCs from different sources and their molecular mechanisms in ALF treatment,along with future perspectives that may provide guidance to improve the current status of MSCs therapy for ALF.

B cell dysfunction in chronic hepatitis B virus infection

Chronic hepatitis B(CHB)remains a global health problem.The persistence of hepatitis B surface antigen(HBsAg)in the blood for longer than 6 months after the initial infection is a sign of CHB.The therapeutic goal for the functional cure of CHB is the generation of antibodies against HBsAg.However,the adaptive immune response of patients with CHB cannot generate an efficient antiviral response.Many previous studies have evaluated T cell function and T cell therapy specifically designed to counter hepatitis B virus(HBV)infection.As one of the major components of adaptive immunity,B cells also display dysfunctions in anti-HBsAg antibody(HBsAb)production and antigen presentation.Patients with CHB have amplification of CD19^(+)CD10^(-)CD27^(-)CD21^(-)atypical memory B cell subsets and CD19^(+)CD24^(hi)CD38^(hi) regulatory B cells.Currently,no reviews have summarized specific B cell responses during CHB infection.Thus,in this study,we summarized B cell dysfunction during CHB progression and the potential mechanisms behind these dysfunctions to further our understanding of the mechanisms of adaptive immune response of B cells in the process of CHB development and help provide new methods and ideas for the treatment of CHB.

Functional roles of CCL5/RANTES in liver disease

Inflammation,which is mediated by leukocyte trafficking and activation,plays a prominent role in the pathogenesis of acute and chronic liver injury.Chemokines are critical mediators involved in the migration of leukocytes into the diseased liver via binding to their G protein-coupled receptors.CeC motif ligand 5(CCL5)belongs to the CC-chemokine family and is secreted by several hepatic cell pop-ulations including hepatocytes,macrophages,hepatic stellate cells,and endothelial cells upon activation.CCL5 regulates the recruitment and migration of T cells(via CCR5)and NK cells(via CCR1).Moreover,CCL5 activates and stimulates T cell proliferation and cytokine production,sequentially regulating in-flammatory responses.Accumulating studies have identified crucial effects of CCL5 both in liver-disease patients and in experimental models,in which CCL5 is elevated and displays distinct effects according to pathological conditions.In this review,we discussed the crucial functions of CCL5 in liver diseases,including acute liver failure,hepatic ischemia-reperfusion injury,acute liver failure,acute and viral hepatitis,alcoholic liver disease,non-alcoholic fatty liver disease,fibrosis,and hepatocellular carcinoma.Continued understanding the roles of CCL5 in liver disease and their mechanisms of activation are indispensable for the development of effective clinical therapeutics.

Metabolic modulation of acetaminophen-induced hepatotoxicity by osteopontin

Induction of osteopontin(OPN),a well-known pro-inflammatory molecule,has been observed in acetaminophen(APAP)-induced hepatotoxicity.However,the precise cell source for OPN induction and its role during APAP-induced hepatotoxicity has not been fully explored.By employing a hepatotoxic mouse model induced by APAP overdose,we demonstrate that both serum and hepatic OPN levels were significantly elevated in response to APAP treatment.Our in vivo and in vitro studies clearly indicated that the induced expression of hepatic OPN was mainly located in necrosis areas and produced by dying or dead hepatocytes.Functional experiments showed that OPN deficiency protected against the APAP-induced liver injury by inhibiting the toxic APAP metabolism via reducing the expression of the cytochrome P450 family 2 subfamily E member 1(CYP2E1).Interestingly,this inhibition of CYP2E1 expression did not occur in unfasted Opn−/−mice,but was significant in fasted Opn−/−mice and maintained for 2hours after APAP challenge in fasted Opn−/−mice.In addition,despite the early protective role of OPN deficiency on APAP-induced hepatotoxicity,OPN deficiency retarded injury resolution by sensitizing hepatocytes to apoptosis and impairing liver regeneration.Finally,we demonstrated that a siRNA-mediated transient hepatic Opn knockdown could sufficiently and significantly protect animals from APAP-induced hepatotoxicity and death.In conclusion,this study clearly defines the cell source of OPN induction in response to APAP treatment,provides a novel insight into the metabolic role of OPN to APAP overdose,and suggests an Opn-targeted therapeutic strategy for the treatment or prevention of APAP-induced hepatotoxicity.

Emerging roles of DJ-1 in liver diseases through regulation of oxidative stress and immune response

Reactive oxygen species(ROS)and immune response play critical roles in the progression of liver diseases.DJ-1,also known as Parkinson disease 7(Park7),is extensively expressed in cells and tissues,where it governs numerous biological functions including chaperone activity,protease function,transcriptional and mitochondrial regulation,and ROS modulation.Moreover,we have established that DJ-1 plays a critical role in initiating an inflammatory response by modulating ROS generation.Therefore,DJ-1 may play an important role in the progression of liver diseases by modulating ROS and the immune response.Recently,we have shown that DJ-1 deficiency negatively regulates proliferation of hepatic progenitor cells(HPCs)by impairing the formation of HPC-associated fibrosis and inflammatory niches.Deficiency of DJ-1 ameliorates liver fibrosis by inhibiting hepatic ROS production and inflammation;moreover,in a classic diethylnitrosamine(DEN)-mediated hepatocellular carcinoma(HCC)mouse model,deletion of DJ-1 ameliorates tumorigenesis and HCC cell proliferation by regulating hepatic inflammation and reducing the activity of the interleukin 6/signal transducer and activator of transcription 3(IL-6/STAT3)signaling pathway.Taken together,these data suggest a critical function for,and therapeutic value of,DJ-1 in treatment of liver diseases.The aim of this review is to summarize these functions and the underlying molecular mechanisms of DJ-1 in liver diseases,and to highlight the potential therapeutic value and future research direction of DJ-1 in liver diseases.