Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

Staging liver fibrosis with various diffusion-weighted magnetic resonance imaging models

BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC.

Alpha-1 antitrypsin deficiency and Pi*Z allele as important co-factors in the development of liver fibrosis

BACKGROUND Alpha-1 antitrypsin deficiency(AATD)is a codominant autosomal hereditary condition that predisposes patients to the development of lung and/or liver disease,and Pi*Z allele is the most clinically relevant mutation.AIM To evaluate the impact of clinical parameters and AATD phenotypes,particularly the Pi*Z allele,in liver fibrosis.METHODS Cross-sectional cohort study including consecutive patients with AATD followed in Pulmonology or Hepatology consultation.RESULTS Included 69 patients,49.3%had Pi*MZ phenotype and 10.1%Pi*ZZ.An age≥55 years,age at diagnosis≥41 years and AAT at diagnosis<77 mg/dL predicted a nonalcoholic fatty liver disease fibrosis score(NFS)not excluding advanced fibrosis[area under the curve(AUC)=0.840,P<0.001;AUC=0.836,P<0.001;AUC=0.681,P=0.025].An age≥50 years and age at diagnosis≥41 years predicted a fibrosis-4 index of moderate to advanced fibrosis(AUC=0.831,P<0.001;AUC=0.795,P<0.001).Patients with hypertension,type 2 diabetes mellitus(DM),dyslipidaemia,metabolic syndrome,and regular alcohol consumption were more likely to have a NFS not excluding advanced fibrosis(P<0.001,P=0.002,P=0.008,P<0.001,P=0.033).Patients with at least one Pi*Z allele and type 2 DM were 8 times more likely to have liver stiffness measurement≥7.1 kPa(P=0.040).CONCLUSION Risk factors for liver disease in AATD included an age≥50 years,age at diagnosis≥41 years,metabolic risk factors,regular alcohol consumption,at least one Pi*Z allele,and AAT value at diagnosis<77 mg/dL.We created an algorithm for liver disease screening in AATD patients to use in primary care,selecting those to be referred to Hepatology consultation.

Ginsenoside Rb1 induces hepatic stellate cell ferroptosis to alleviate liver fibrosis via the BECN1/SLC7A11 axis

Liver fibrosis is primarily driven by the activation of hepatic stellate cells(HSCs),a process associated with ferroptosis.Ginsenoside Rb1(GRb1),a major active component extracted from Panax ginseng,inhibits HSC activation.However,the potential role of GRb1 in mediating HSC ferroptosis remains unclear.This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro,using CCl4-induced liver fibrosis mouse model and primary HSCs,LX-2 cells.The findings revealed that GRb1 effectively inactivated HSCs in vitro,reducing alpha-smooth muscle actin(a-SMA)and type I collagen(Col1A1)levels.Moreover,GRb1 significantly alleviated CCl4-induced liver fibrosis in vivo.From a mechanistic standpoint,the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1.Specifically,GRb1 promoted HSC ferroptosis both in vivo and in vitro,characterized by increased glutathione depletion,malondialdehyde production,iron overload,and accumulation of reactive oxygen species(ROS).Intriguingly,GRb1 increased Beclin 1(BECN1)levels and decreased the System Xc-key subunit SLC7A11.Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1.Moreover,BECN1 could directly interact with SLC7A11,initiating HSC ferroptosis.In conclusion,the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro.Overall,this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation,at least partly through its modulation of BECN1 and SLC7A11.

Quantitative Assessment of Liver Fibrosis by Elastography in Patients with Chronic Liver Disease: A Cross-Sectional Study in Lomé (Togo)

Aim: To describe the two-dimensional elastographic profile according to the Shearwave (2D-SWE) technique in patients with chronic liver disease in Lom. Materials and method: Cross-sectional, descriptive study conducted over seven month at the Autel dElie Clinic in Lom, from January to August 2022, on adult patients with chronic liver disease who underwent abdominal ultrasound coupled with two-dimensional elastography. Results: The sample size was 54 patients. The mean age of the patients was 33 12 years, with extremes of 18 and 66 years. Patients aged 30 years or less accounted for 48.1% (n = 26). All patients (n = 54) had at least one transaminase assay with a mean of 69.3 78.3 IU/l (AST) and 59.3 82.8 IU/l (ALT). There was no statistically significant association between the biological parameters and the presence of fibrosis. Viral liver disease was the main cause, accounting for 81.5% (n = 44) of cases, with no significant association with the degree of fibrosis. Ultrasound revealed a dysmorphic liver (57.4%;n = 31) and portal hypertension (18.5%, n = 10). Fibrosis stages F1, F2 and F4 accounted for (48.1%, n = 26), (24.1%, n = 13) and (13%, n = 7) of cases respectively. Liver dysmorphia was significantly associated with the presence of fibrosis (p = 0.012) and portal hypertension was significantly associated with the degree of fibrosis (p = 0.0063). Conclusion: Assessment of liver fibrosis in patients with chronic liver disease using 2D-SWE elastography is essential for patient follow-up.

Angiotensin-converting enzyme 2 and AMPK/mTOR pathway in the treatment of liver fibrosis:Should we consider further implications?

This editorial contains comments on the article by Zhao et al in print in the World Journal of Gastroenterology.The mechanisms responsible for hepatic fibrosis are also involved in cancerogenesis.Here,we recapitulated the complexity of the renin-angiotensin system,discussed the role of hepatic stellate cell(HSC)autophagy in liver fibrogenesis,and analyzed the possible implications in the development of hepatocarcinoma(HCC).Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers definitively contribute to reducing hepatic fibrogenesis,whereas their involvement in HCC is more evident in experimental conditions than in human studies.Angiotensin-converting enzyme 2(ACE2),and its product Angiotensin(Ang)1-7,not only regulate HSC autophagy and liver fibrosis,but they also represent potential targets for unexplored applications in the field of HCC.Finally,ACE2 overexpression inhibits HSC autophagy through the AMP-activated protein kinase(AMPK)/mammalian target of rapamycin(mTOR)pathway.In this case,Ang 1-7 acts binding to the MasR,and its agonists could modulate this pathway.However,since AMPK utilizes different targets to suppress the mTOR downstream complex mTOR complex 1 effectively,we still need to unravel the entire pathway to identify other potential targets for the therapy of fibrosis and liver cancer.

Metabolic puzzle: Exploring liver fibrosis differences in Asian metabolic-associated fatty liver disease subtypes

BACKGROUND Metabolic-associated fatty liver disease(MAFLD)is a liver condition marked by excessive fat buildup in the absence of heavy alcohol use.It is primarily linked with metabolic issues like insulin resistance,obesity,and abnormal lipid levels,and is often observed with other conditions such as type 2 diabetes and cardiovascular disease.However,whether the subtypes of MAFLD based on the metabolic disorder differentially impact liver fibrosis is not well explicated,especially in the Asian population.AIM To compare the severity of liver fibrosis among different MAFLD subtypes.METHODS A total of 322 adult patients of either gender with fatty liver on ultrasound were enrolled between January to December 2021.MAFLD was defined as per the Asian Pacific Association for the Study of the Liver guidelines.Fibrosis-4 index(Fib-4)and nonalcoholic fatty liver disease fibrosis score(NFS)were employed to evaluate liver fibrosis.RESULTS The mean age was 44.84±11 years.Seventy-two percent of the patients were female.Two hundred and seventy-three patients were classified as having MAFLD,of which 110(40.3%)carried a single,129(47.3%)had two,and 34(12.5%)had all three metabolic conditions.The cumulative number of metabolic conditions was related to elevated body mass index,triglyceride(TG)levels,and glycated hemoglobin,lower high-density lipoprotein(HDL)levels,higher liver inflammation(by aspartate aminotransferase andγ-glutamyl transferase),and higher likelihood of fibrosis(by NFS and Fib-4 scores)(P<0.05 for all).The proportion of advanced fibrosis also increased with an increase in the number of metabolic conditions(4.1%,25.5%,35.6%,and 44.1%by NFS and 6.1%,10.9%,17%,and 26.5%by Fib-4 for no MAFLD and MAFLD with 1,2,and 3 conditions,respectively).Among MAFLD patients,those with diabetes alone were the eldest and had the highest mean value of NFS score and Fib-4 score(P<0.05),while MAFLD patients diagnosed with lean metabolic dysfunction exhibited the highest levels of TG and alanine aminotransferase but the lowest HDL levels(P<0.05).CONCLUSION The study suggests that the severity of liver fibrosis in MAFLD patients is influenced by the number and type of metabolic conditions present.Early identification and management of MAFLD,particularly in patients with multiple metabolic conditions,are crucial to prevent liver-related complications.

Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease

BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis.Peroxisome proliferator activated receptor(PPAR)α and δ play a key role in lipid metabolism and intestinal barrier homeostasis,which are major contributors to the pathological progression of ALD.Meanwhile,elafibranor(EFN),which is a dual PPARαand PPARδagonist,has reached a phase III clinical trial for the treatment of metabolic dysfunctionassociated steatotic liver disease and primary biliary cholangitis.However,the benefits of EFN for ALD treatment is unknown.AIM To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model.METHODS ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol(EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly(1 mL/kg)for 8 weeks.EFN(3 and 10 mg/kg/day)was orally administered during the experimental period.Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis,fibrosis,and intestinal barrier integrity.The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays.RESULTS The hepatic steatosis,apoptosis,and fibrosis in the ALD mice model were significantly attenuated by EFN treatment.EFN promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells,primarily through PPARαactivation.Moreover,EFN inhibited the Kupffer cell-mediated inflammatory response,with blunted hepatic exposure to lipopolysaccharide(LPS)and toll like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling.EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses.The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation.CONCLUSION EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis,enhancing hepatocyte autophagic and antioxidant capacities,and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function.

Peroxisome proliferator-activated receptors gama ameliorates liver fibrosis in non-alcoholic fatty liver disease by inhibiting TGF-β/Smad signaling activation

Background:Nonalcoholic fatty liver disease(NAFLD)is a chronic condition characterized by a progressive decline in liver function,leading to disruptions in liver integrity and metabolic function,resulting in lipid deposition and excessive accumulation of extracellular matrix(ECM).The pathogenesis of NAFLD is complex and not yet fully understood,contributing to the absence of specific therapeutic strategies.Peroxisome proliferator-activated receptor gamma(PPARγ)is a ligand-activated transcription factor pivotal in regulating lipid and glucose metabolism.However,the impacts of PPARγon NAFLD remains insufficiently explored.Thus,this study aimed to investigate the role of PPARγin NAFLD and its underlying molecular mechanisms.Methods:Chemical detection kits were utilized to quantify collagen content,alanine aminotransferase(ALT),and aspartate aminotransferase(AST)level variations.Quantitative real-time polymerase chain reaction(qRT-PCR)was employed to assess alterations in extracellular matrix-related genes and inflammatory response genes in liver tissue and HepG2 cells,while western blotting was conducted to analyze the levels of both PPARγand the TGF-β/Smad signaling pathway.Results:Our findings unveiled significantly reduced PPARγexpression in a rat model of NAFLD,leading to subsequent activation of the TGF-β/Smad signaling pathway.Furthermore,PPARγactivation effectively mitigated NAFLD progression by inhibiting inflammation and fibrosis-related gene expression and collagen production.On a cellular level,PPARγactivation was found to inhibit the expression of extracellular matrix-related genes such as matrix metalloproteinase 2(MMP2)and matrix metalloproteinase 9(MMP9),along with inflammatory response genes interleukin(IL)-1βand IL-6.Additionally,PPARγactivation led to a significant decrease in the levels of ALT and AST.At the molecular level,PPARγnotably down-regulated the TGF-β/Smad signaling pathway,which is known to promote liver fibrosis.Conclusion:These groundbreaking findings underscore PPARγactivation as a promising therapeutic approach to delay NAFLD progression by targeting the TGF-β/Smad signaling pathway in hepatic cells.This highlights the potential of PPARγas a promising therapeutic target for NAFLD management in clinical settings.

Transient elastography and diffusion-weighted magnetic resonance imaging for assessment of liver fibrosis in children with chronic hepatitis C

BACKGROUND Chronic hepatitis C(CHC)is a health burden with consequent morbidity and mortality.Liver biopsy is the gold standard for evaluating fibrosis and assessing disease severity and prognostic purposes post-treatment.Noninvasive altern-atives for liver biopsy such as transient elastography(TE)and diffusion-weighted magnetic resonance imaging(DW-MRI)are critical needs.AIM To evaluate TE and DW-MRI as noninvasive tools for predicting liver fibrosis in children with CHC.METHODS This prospective cross-sectional study initially recruited 100 children with CHC virus infection.Sixty-four children completed the full set of investigations including liver stiffness measurement(LSM)using TE and measurement of apparent diffusion coefficient(ADC)of the liver and spleen using DW-MRI.Liver biopsies were evaluated for fibrosis using Ishak scoring system.LSM and liver and spleen ADC were compared in different fibrosis stages and correlation analysis was performed with histopathological findings and other laboratory parameters.RESULTS Most patients had moderate fibrosis(73.5%)while 26.5%had mild fibrosis.None had severe fibrosis or cirrhosis.The majority(68.8%)had mild activity,while only 7.8%had moderate activity.Ishak scores had a significant direct correlation with LSM(P=0.008)and were negatively correlated with both liver and spleen ADC but with no statistical significance(P=0.086 and P=0.145,respectively).Similarly,histopatho-logical activity correlated significantly with LSM(P=0.002)but not with liver or spleen ADC(P=0.84 and 0.98 respectively).LSM and liver ADC were able to significantly discriminate F3 from lower fibrosis stages(area under the curve=0.700 and 0.747,respectively)with a better performance of liver ADC.CONCLUSION TE and liver ADC were helpful in predicting significant fibrosis in children with chronic hepatitis C virus infection with a better performance of liver ADC.

Yinhuang granule alleviates carbon tetrachloride-induced liver fibrosis in mice and its mechanism

BACKGROUND Liver fibrosis is a formidable global medical challenge,with no effective clinical treatment currently available.Yinhuang granule(YHG)is a proprietary Chinese medicine comprising Scutellariae Radix and Lonicerae Japonicae Flos.It is frequently used for upper respiratory tract infections,pharyngitis,as well as acute and chronic tonsillitis.AIM To investigate the potential of YHG in alleviating carbon tetrachloride(CCl4)-induced liver fibrosis in mice.METHODS To induce a hepatic fibrosis model in mice,this study involved intraperitoneal injections of 2 mL/kg of CCl4 twice a week for 4 wk.Meanwhile,liver fibrosis mice in the low dose of YHG(0.4 g/kg)and high dose of YHG(0.8 g/kg)groups were orally administered YHG once a day for 4 wk.Serum alanine/aspartate aminotransferase(ALT/AST)activity and liver hydroxyproline content were detected.Sirius red and Masson's trichrome staining assay were conducted.Realtime polymerase chain reaction,western-blot and enzyme-linked immunosorbent assay were conducted.Liver glutathione content,superoxide dismutase activity level,reactive oxygen species and protein carbonylation amount were detected.RESULTS The administration of YHG ameliorated hepatocellular injury in CCl4-treated mice,as reflected by decreased serum ALT/AST activity and improved liver histological evaluation.YHG also attenuated liver fibrosis,evident through reduced liver hydroxyproline content,improvements in Sirius red and Masson's trichrome staining,and lowered serum hyaluronic acid levels.Furthermore,YHG hindered the activation of hepatic stellate cells(HSCs)and ameliorated oxidative stress injury and inflammation in liver from CCl4-treated mice.YHG prompted the nuclear accumulation of nuclear factor erythroid 2-related factor 2(Nrf2)and upregulated the expression of Nrf2-dependent downstream antioxidant genes.In addition,YHG promoted mitochondrial biogenesis in liver from CCl4-treated mice,as demonstrated by increased liver adenosine triphosphate content,mitochondrial DNA levels,and the expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha and nuclear respiratory factor 1.CONCLUSION YHG effectively attenuates CCl4-induced liver fibrosis in mice by inhibiting the activation of HSCs,reducing inflammation,alleviating liver oxidative stress damage through Nrf2 activation,and promoting liver mitochondrial biogenesis.

Ensemble for evaluating diagnostic efficacy of non-invasive indices in predicting liver fibrosis in untreated hepatitis C virus population

BACKGROUND Hepatitis C virus(HCV)infection progresses through various phases,starting with inflammation and ending with hepatocellular carcinoma.There are several invasive and non-invasive methods to diagnose chronic HCV infection.The invasive methods have their benefits but are linked to morbidity and complications.Thus,it is important to analyze the potential of non-invasive methods as an alternative.Shear wave elastography(SWE)is a non-invasive imaging tool widely validated in clinical and research studies as a surrogate marker of liver fibrosis.Liver fibrosis determination by invasive liver biopsy and non-invasive SWE agree closely in clinical studies and therefore both are gold standards.AIM To analyzed the diagnostic efficacy of non-invasive indices[serum fibronectin,aspartate aminotransferase to platelet ratio index(APRI),alanine aminotransferase ratio(AAR),and fibrosis-4(FIB-4)]in relation to SWE.We have used an Artificial Intelligence method to predict the severity of liver fibrosis and uncover the complex relationship between non-invasive indices and fibrosis severity.METHODS We have conducted a hospital-based study considering 100 untreated patients detected as HCV positive using a quantitative Real-Time Polymerase Chain Reaction assay.We performed statistical and probabilistic analyses to determine the relationship between non-invasive indices and the severity of fibrosis.We also used standard diagnostic methods to measure the diagnostic accuracy for all the subjects.RESULTS The results of our study showed that fibronectin is a highly accurate diagnostic tool for predicting fibrosis stages(mild,moderate,and severe).This was based on its sensitivity(100%,92.2%,96.2%),specificity(96%,100%,98.6%),Youden’s index(0.960,0.922,0.948),area under receiver operating characteristic curve(0.999,0.993,0.922),and Likelihood test(LR+>10 and LR-<0.1).Additionally,our Bayesian Network analysis revealed that fibronectin(>200),AAR(>1),APRI(>3),and FIB-4(>4)were all strongly associated with patients who had severe fibrosis,with a 100% probability.CONCLUSION We have found a strong correlation between fibronectin and liver fibrosis progression in HCV patients.Additionally,we observed that the severity of liver fibrosis increases with an increase in the non-invasive indices that we investigated.

A novel pulmonary fibrosis murine model with immune-related liver injury

Idiopathic pulmonary fibrosis(IPF),characterized by aggravated alveolar destruc-tion and fibrotic matrix deposition,tendentiously experiences the stage called acute exacerbation IPF(AE-IPF)and progresses to multiple organ damage,especially liver injury.Recent studies have found a variety of immune microenvironment disorders associated with elevated IPF risk and secondary organ injury,whereas current animal models induced with bleomycin(BLM)could not completely reflect the pathologi-cal manifestations of AE-IPF patients in clinic,and the exact underlying mechanisms are not yet fully explored.In the current study,we established an AE-IPF model by tracheal administration of a single dose of BLM and then repeated administrations of lipopolysaccharide in mice.This mouse model successfully recapitulated the clinical features of AE-IPF,including excessive intrapulmonary inflammation and fibrosis and extrapulmonary manifestations,as indicated by significant upregulation of Il6,Tnfa,Il1b,Tgfb,fibronectin,and Col1a1 in both lungs and liver and elevated serum aspartate transaminase and alanine transaminase levels.These effects might be attributed to the regulation of Th17 cells.By sharing this novel murine model,we expect to pro-vide an appropriate experimental platform to investigate the pathogenesis of AE-IPF coupled with liver injury and contribute to the discovery and development of targeted interventions.

Cornus officinalis with high pressure wine steaming enhanced anti-hepatic fibrosis: Possible through SIRT3-AMPK axis

Cornus officinalis,a medicinal and edible plant known for its liver-nourishing properties,has shown promise in inhibiting the activation of hepatic stellate cells(HSCs),crucial indicators of hepatic fibrosis,especially when processed by high pressure wine steaming(HPWS).Herein,this study aims to investigate the regulatory effects of cornus officinalis,both in its raw and HPWS forms,on inflammation and apoptosis in liver fibrosis and their underlying mechanisms.In vivo liver fibrosis models were established by subcutaneous injection of CCl4,while in vitro HSCs were exposed to transforming growth factor-b(TGF-b).These findings demonstrated that cornus officinalis with HPWS conspicuously ameliorated histopathological injury,reduced the release of proinflammatory factors,and decreased collagen deposition in CCl4-induced rats compared to its raw form.Utilizing ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometer(UHPLC-QTOF-MS)combined with network analysis,we identified that the pharmacological effects of the changed components of cornus officinalis before and after HPWS,primarily centered on the adenosine phosphate(AMP)-activated protein kinase(AMPK)pathway.Of note,cornus officinalis activated AMPK and sirtuin 3(SIRT3),promoting the apoptosis of activated HSCs through the caspase cascade by regulating caspase3,caspase6 and caspase9.small interfering RNA(siRNA)experiments showed that cornus officinalis could regulate AMPK activity and its mediated-apoptosis through SIRT3.In conclusion,cornus officinalis exhibited the ability to reduce inflammation and apoptosis,with the SIRT3-AMPK signaling pathway identified as a potential mechanism underlying the synergistic effect of cornus officinalis with HPWS on anti-liver fibrosis.

Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells

BACKGROUND Liver fibrosis is the common pathological process associated with the occurrence and development of various chronic liver diseases.At present,there is still a lack of effective prevention and treatment methods in clinical practice.Hepatic stellate cell(HSC)plays a key role in liver fibrogenesis.In recent years,the study of liver fibrosis targeting HSC autophagy has become a hot spot in this research field.Angiotensin-converting enzyme 2(ACE2)is a key negative regulator of reninangiotensin system,and its specific molecular mechanism on autophagy and liver fibrosis needs to be further explored.AIM To investigate the effect of ACE2 on hepatic fibrosis in mice by regulating HSC autophagy through the Adenosine monophosphate activates protein kinases(AMPK)/mammalian target of rapamycin(mTOR)pathway.METHODS Overexpression of ACE2 in a mouse liver fibrosis model was induced by injection of liver-specific recombinant adeno-associated virus ACE2 vector(rAAV2/8-ACE2).The degree of liver fibrosis was assessed by histopathological staining and the biomarkers in mouse serum were measured by Luminex multifactor analysis.The number of apoptotic HSCs was assessed by terminal deoxynucleoitidyl transferase-mediated dUTP nick-end labeling(TUNEL)and immunofluorescence staining.Transmission electron microscopy was used to identify the changes in the number of HSC autophagosomes.The effect of ACE2 overexpression on Wu Y et al.ACE2 improves liver fibrosis through autophagy WJG https://www.wjgnet.com 4976 September 7,2023 Volume 29 Issue 33 autophagy-related proteins was evaluated by multicolor immunofluorescence staining.The expression of autophagy-related indicators and AMPK pathway-related proteins was measured by western blotting.RESULTS A mouse model of liver fibrosis was successfully established after 8 wk of intraperitoneal injection of carbon tetrachloride(CCl4).rAAV2/8-ACE2 administration reduced collagen deposition and alleviated the degree of liver fibrosis in mice.The serum levels of platelet-derived growth factor,angiopoietin-2,vascular endothelial growth factor and angiotensin II were decreased,while the levels of interleukin(IL)-10 and angiotensin-(1-7)were increased in the rAAV2/8-ACE2 group.In addition,the expression of alpha-smooth muscle actin,fibronectin,and CD31 was down-regulated in the rAAV2/8-ACE2 group.TUNEL and immunofluorescence staining showed that rAAV2/8-ACE2 injection increased HSC apoptosis.Moreover,rAAV2/8-ACE2 injection notably decreased the number of autophagosomes and the expression of autophagy-related proteins(LC3I,LC3II,Beclin-1),and affected the expression of AMPK pathway-related proteins(AMPK,p-AMPK,p-mTOR).CONCLUSION ACE2 overexpression can inhibit HSC activation and promote cell apoptosis by regulating HSC autophagy through the AMPK/mTOR pathway,thereby alleviating liver fibrosis and hepatic sinusoidal remodeling.

Role of noncoding RNAs in liver fibrosis

Liver fibrosis is a wound-healing response following chronic liver injury caused by hepatitis virus infection,obesity,or excessive alcohol.It is a dynamic and reversible process characterized by the activation of hepatic stellate cells and excess accumulation of extracellular matrix.Advanced fibrosis could lead to cirrhosis and even liver cancer,which has become a significant health burden worldwide.Many studies have revealed that noncoding RNAs(ncRNAs),including microRNAs,long noncoding RNAs and circular RNAs,are involved in the pathogenesis and development of liver fibrosis by regulating signaling pathways including transforming growth factor-βpathway,phosphatidylinositol 3-kinase/protein kinase B pathway,and Wnt/β-catenin pathway.NcRNAs in serum or exosomes have been reported to tentatively applied in the diagnosis and staging of liver fibrosis and combined with elastography to improve the accuracy of diagnosis.NcRNAs mimics,ncRNAs in mesenchymal stem cell-derived exosomes,and lipid nanoparticles-encapsulated ncRNAs have become promising therapeutic approaches for the treatment of liver fibrosis.In this review,we update the latest knowledge on ncRNAs in the pathogenesis and progression of liver fibrosis,and discuss the potentials and challenges to use these ncRNAs for diagnosis,staging and treatment of liver fibrosis.All these will help us to develop a comprehensive understanding of the role of ncRNAs in liver fibrosis.

Treatment of liver fibrosis:Past,current,and future

Liver fibrosis accompanies the progression of chronic liver diseases independent of etiologies,such as hepatitis viral infection,alcohol consumption,and metabolicassociated fatty liver disease.It is commonly associated with liver injury,inflammation,and cell death.Liver fibrosis is characterized by abnormal accumulation of extracellular matrix components that are expressed by liver myofibroblasts such as collagens and alpha-smooth actin proteins.Activated hepatic stellate cells contribute to the major population of myofibroblasts.Many treatments for liver fibrosis have been investigated in clinical trials,including dietary supplementation(e.g.,vitamin C),biological treatment(e.g.,simtuzumab),drug(e.g.,pegbelfermin and natural herbs),genetic regulation(e.g.,non-coding RNAs),and transplantation of stem cells(e.g.,hematopoietic stem cells).However,none of these treatments has been approved by Food and Drug Administration.The treatment efficacy can be evaluated by histological staining methods,imaging methods,and serum biomarkers,as well as fibrosis scoring systems,such as fibrosis-4 index,aspartate aminotransferase to platelet ratio,and non-alcoholic fatty liver disease fibrosis score.Furthermore,the reverse of liver fibrosis is slowly and frequently impossible for advanced fibrosis or cirrhosis.To avoid the lifethreatening stage of liver fibrosis,anti-fibrotic treatments,especially for combined behavior prevention,biological treatment,drugs or herb medicines,and dietary regulation are needed.This review summarizes the past studies and current and future treatments for liver fibrosis.

Single-cell transcriptomic dissection of the cellular and molecular events underlying the triclosan-induced liver fibrosis in mice

Background: Triclosan [5-chloro-2-(2,4-dichlorophenoxy) phenol, TCS], a common antimicrobial additive in many personal care and health care products, is frequently detected in human blood and urine. Therefore, it has been considered an emerging and potentially toxic pollutant in recent years. Long-term exposure to TCS has been suggested to exert endocrine disruption effects, and promote liver fibrogenesis and tumorigenesis. This study was aimed at clarifying the underlying cellular and molecular mechanisms of hepatotoxicity effect of TCS at the initiation stage.Methods: C57BL/6 mice were exposed to different dosages of TCS for 2 weeks and the organ toxicity was evaluated by various measurements including complete blood count, histological analysis and TCS quantification. Single cell RNA sequencing(scRNA-seq) was then carried out on TCS-or mock-treated mice livers to delineate the TCS-induced hepatotoxicity. The acquired single-cell transcriptomic data were analyzed from different aspects including differential gene expression, transcription factor(TF) regulatory network, pseudotime trajectory, and cellular communication, to systematically dissect the cellular and molecular events after TCS exposure. To verify the TCS-induced liver fibrosis,the expression levels of key fibrogenic proteins were examined by Western blotting, immunofluorescence, Masson’s trichrome and Sirius red stainings. In addition, normal hepatocyte cell MIHA and hepatic stellate cell LX-2 were used as in vitro cell models to experimentally validate the effects of TCS by immunological, proteomic and metabolomic technologies.Results: We established a relatively short term TCS exposure murine model and found the TCS mainly accumulated in the liver. The scRNA-seq performed on the livers of the TCS-treated and control groups profiled the gene expressions of > 76,000 cells belonging to 13 major cell types. Among these types, hepatocytes and hepatic stellate cells(HSCs)were significantly increased in TCS-treated group. We found that TCS promoted fibrosis-associated proliferation of hepatocytes, in which Gata2 and Mef2c are the key driving TFs. Our data also suggested that TCS induced the proliferation and activation of HSCs, which was experimentally verified in both liver tissue and cell model. In addition,other changes including the dysfunction and capillarization of endothelial cells, an increase of fibrotic characteristics in B plasma cells, and M2 phenotype-skewing of macrophage cells, were also deduced from the scRNA-seq analysis, and these changes are likely to contribute to the progression of liver fibrosis. Lastly, the key differential ligand-receptor pairs involved in cellular communications were identified and we confirmed the role of GAS6_AXL interactionmediated cellular communication in promoting liver fibrosis.Conclusions: TCS modulates the cellular activities and fates of several specific cell types(including hepatocytes, HSCs,endothelial cells, B cells, Kupffer cells and liver capsular macrophages) in the liver, and regulates the ligand-receptor interactions between these cells, thereby promoting the proliferation and activation of HSCs, leading to liver fibrosis.Overall, we provide the first comprehensive single-cell atlas of mice livers in response to TCS and delineate the key cellular and molecular processes involved in TCS-induced hepatotoxicity and fibrosis.

HepG2.2.15-derived exosomes facilitate the activation and fibrosis of hepatic stellate cells

BACKGROUND The role of exosomes derived from HepG2.2.15 cells,which express hepatitis B virus(HBV)-related proteins,in triggering the activation of LX2 liver stellate cells and promoting liver fibrosis and cell proliferation remains elusive.The focus was on comprehending the relationship and influence of differentially expressed microRNAs(DE-miRNAs)within these exosomes.AIM To elucidate the effect of exosomes derived from HepG2.2.15 cells on the activation of hepatic stellate cell(HSC)LX2 and the progression of liver fibrosis.METHODS Exosomes from HepG2.2.15 cells,which express HBV-related proteins,were isolated from parental HepG2 and WRL68 cells.Western blotting was used to confirm the presence of the exosomal marker protein CD9.The activation of HSCs was assessed using oil red staining,whereas DiI staining facilitated the observation of exosomal uptake by LX2 cells.Additionally,we evaluated LX2 cell proliferation and fibrosis marker expression using 5-ethynyl-2′-deoxyuracil staining and western blotting,respectively.DE-miRNAs were analyzed using DESeq2.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways were used to annotate the target genes of DE-miRNAs.RESULTS Exosomes from HepG2.2.15 cells were found to induced activation and enhanced proliferation and fibrosis in LX2 cells.A total of 27 miRNAs were differentially expressed in exosomes from HepG2.2.15 cells.GO analysis indicated that these DE-miRNA target genes were associated with cell differentiation,intracellular signal transduction,negative regulation of apoptosis,extracellular exosomes,and RNA binding.KEGG pathway analysis highlighted ubiquitin-mediated proteolysis,the MAPK signaling pathway,viral carcinogenesis,and the toll-like receptor signaling pathway,among others,as enriched in these targets.CONCLUSION These findings suggest that exosomes from HepG2.2.15 cells play a substantial role in the activation,proliferation,and fibrosis of LX2 cells and that DE-miRNAs within these exosomes contribute to the underlying mechanisms.

Cell atlas of CCl_(4)-induced progressive liver fibrosis reveals stage-specific responses

Chronic liver injury leads to progressive liver fibrosis and ultimately cirrhosis,a major cause of morbidity and mortality worldwide.However,there are currently no effective anti-fibrotic therapies available,especially for latestage patients,which is partly attributed to the major knowledge gap regarding liver cell heterogeneity and cellspecific responses in different fibrosis stages.To reveal the multicellular networks regulating mammalian liver fibrosis from mild to severe phenotypes,we generated a single-nucleus transcriptomic atlas encompassing 49919nuclei corresponding to all main liver cell types at different stages of murine carbon tetrachloride(CCl_(4))-induced progressive liver fibrosis.Integrative analysis distinguished the sequential responses to injury of hepatocytes,hepatic stellate cells and endothelial cells.Moreover,we reconstructed the cell-cell interactions and gene regulatory networks implicated in these processes.These integrative analyses uncovered previously overlooked aspects of hepatocyte proliferation exhaustion and disrupted pericentral metabolic functions,dysfunction for clearance by apoptosis of activated hepatic stellate cells,accumulation of pro-fibrotic signals,and the switch from an anti-angiogenic to a pro-angiogenic program during CCl_(4)-induced progressive liver fibrosis.Our dataset thus constitutes a useful resource for understanding the molecular basis of progressive liver fibrosis using a relevant animal model.