Antifibrotic therapy in chronic liver disease

Evaluation of the efficacy of Biejia decoction pill combined with entecavir in the treatment of hepatitis B liver fibrosis/cirrhosis by VCTE

The vibration controlled transient elastography (VCTE) technique was used to assess the effectiveness of a Biejia Decoction pill in combination with Entecavir in the treatment of hepatitis B liver fibrosis/cirrhosis. We randomly selected 120 patients to receive entecavir and 119 patients to receive both entecavir and Biejia Decoction Pill, which both with hepatitis B liver fibrosis/cirrhosis visited the Second Affiliated Hospital of Nanchang University between January 2019 and February 2022. The observation group got ETV (entecavir) and Biejia Decoction pills, whereas the control group received only standard ETV antiviral medication. Based on the grading of the VCTE detection value (LSM) initially diagnosed for patients with hepatitis B liver fibrosis/cirrhosis, we divided the patients into two subgroups of liver fibrosis and cirrhosis. In addition, patients with liver fibrosis were divided into mild and moderate subgroups according to their VCTE values. Patients were measured for liver hardness after three, six, nine, and twelve months of treatment with VCTE. Biejia Decoction Pill combined with ETV on HBV liver fibrosis/cirrhosis was evaluated by comparing patients' changes in liver hardness and HBV-DNA negative conversion rates before and after treatment in each group at the same baseline. The LSM (liver elasticity value) of the observation group and the control group after treatment was lower than that before treatment, and the difference was statistically significant (P < 0.0001); The LSM of the observation group after treatment was significantly lower than that of the control group, and the difference was also statistically significant (P = 0.0005 < 0.05). In the subgroup of liver fibrosis, the number of patients with moderate and severe liver fibrosis who completely reversed liver fibrosis after treatment in the treatment group was far more than that in the control group, and the difference between the two groups was statistically significant (χ2 = 4.82 P = 0.028 < 0.05) 。 When the treatment course was more than 9 months, the negative conversion rate of patients in the observation group reached 87.4%, which was higher than that in the control group (70.8%), and the difference was statistically significant (P = 0.002 < 0.05); After 12 months of treatment, the negative conversion rate of patients in the observation group was as high as 95%, which was significantly higher than 76.67% in the control group (P < 0.001). The degree of liver fibrosis was significantly improved when Biejia Decoction Pill was combined with ETV in patients with liver fibrosis/cirrhosis due to hepatitis B. The virological response rate to HBV-DNA increased with the prolongation of treatment, and the Biejia Decoction Pill assists with entecavir in antiviral therapy.

Roles of Macrophages in Advanced Liver Fibrosis, Identified Using a Newly Established Mouse Model of Diet-Induced Non-Alcoholic Steatohepatitis

Macrophages play critical roles in the pathogenesis of non-alcoholic steatohepatitis (NASH). However, it is unclear which macrophage subsets are critically involved in the development of inflammation and fibrosis in NASH. In TSNO mice fed a high-fat/cholesterol/cholate-based diet, which exhibit advanced liver fibrosis that mimics human NASH, we found that Kupffer cells (KCs) were less abundant and recruited macrophages were more abundant, forming hepatic crown-like structures (hCLS) in the liver. The recruited macrophages comprised two subsets: CD11c+/Ly6C- and CD11c-/Ly6C+ cells. CD11c+ cells were present in a mesh-like pattern around the lipid droplets, constituting the hCLS. In addition, CD11c+ cells colocalized with collagen fibers, suggesting that this subset of recruited macrophages might promote advanced liver fibrosis. In contrast, Ly6C+ cells were present in doughnut-like inflammatory lesions, with a lipid droplet in the center. Finally, RNA sequence analysis indicates that CD11c+/Ly6C- cells promote liver fibrosis and hepatic stellate cell (HSC) activation, whereas CD11c-/Ly6C+ cells are a macrophage subset that play an anti-inflammatory role and promote tissue repair in NASH. Taken together, our data revealed changes in liver macrophage subsets during the development of NASH and shed light on the roles of the recruited macrophages in the pathogenesis of advanced fibrosis in NASH.

NR4A1 inhibits the epithelial–mesenchymal transition of hepatic stellate cells: Involvement of TGF-β–Smad2/3/4–ZEB signaling

This study aimed to examine whether nuclear receptor 4a1 (NR4A1) is involved in inhibiting hepatic stellate cell (HSC) activation and liver fibrosis through the epithelial–mesenchymal transition (EMT). HSC-T6 cells were divided into the control group, the acetaldehyde (200 μM, an EMT activator) group, and the NR4A1 activation group (Cytosporone B; 1 μM). The expression levels of the epithelial marker E-cadherin, the mesenchymal markers fibronectin (FN), vimentin, smooth muscle alpha-actin (α-SMA), and fibroblast-specific protein 1 (FSP-1), and the components of the transforming growth factor (TGF)-β pathway were detected by real-time polymerase chain reaction and western blotting. Compared with the control group, E-cadherin in the acetaldehyde group was downregulated, whereas FN, FSP-1, vimentin, α-SMA, and COL1A1/COL1A2 were upregulated (P < 0.05). Compared with the acetaldehyde group, NR4A1 agonist upregulated E-cadherin and downregulated FN, FSP-1, vimentin, α-SMA, and COL1A1/COL1A2 (P < 0.05). After acetaldehyde stimulation, TGF-β, Smad2/3/4, and zinc finger E-box-binding homeobox (ZEB) were upregulated, while Smad7 mRNA levels were downregulated (all P < 0.05). Compared with acetaldehyde alone, NR4A1 agonist increased Smad7 mRNA levels and reduced TGF-β, Smad2/3/4, and ZEB mRNA levels (all P < 0.05). NR4A1 activation suppresses acetaldehyde-induced EMT, as shown by epithelial and mesenchymal marker expression. The inhibition of the TGF-β–Smad2/3/4–ZEB signaling during HSC activation might be involved.

Therapeutic Potential of HNF4α in End-stage Liver Disease

The prevalence of end-stage liver disease (ESLD) in the US is increasing at an alarming rate. It can be caused by several factors; however, one of the most common routes begins with nonalcoholic fatty liver disease (NAFLD). ESLD is diagnosed by the presence of irreversible damage to the liver. Currently, the only definitive treatment for ESLD is orthotopic liver transplantation (OLT). Nevertheless, OLT is limited due to a shortage of donor livers. Several promising alternative treatment options are under investigation. Researchers have focused on the effect of liver-enriched transcription factors (LETFs) on disease progression. Specifically, hepatocyte nuclear factor 4-alpha (HNF4α) has been reported to reset the liver transcription network and possibly play a role in the regression of fibrosis and cirrhosis. In this review, we describe the function of HNF4α, along with its regulation at various levels. In addition, we summarize the role of HNF4α in ESLD and its potential as a therapeutic target in the treatment of ESLD.

RUNX1 regulates SMAD1 by transcriptionally activating the expression of USP9X, regulating the activation of hepatic stellate cells and liver fibrosis

Liver fibrosis (LF) is a common pathological process with high morbidity and mortality. Runt-related transcription factor 1 (RUNX1) is a transcription factor that could cause nephropathy and renal fibrosis, but its role in LF is unclear. Therefore, this study aimed to investigate the role RUNX1 in LF. Briefly, hepatic fibrosis was detected by Sirius Red staining. Transcript levels were quantified by qPCR, and proteins were assessed by western blotting or immunofluorescence. Cell viability and cell migration were measured by CCK8 assays and wound healing assays, respectively. The binding of RUNX1 and ubiquitin-specific protease 9X (USP9X) promoter was validated by ChIP assays and luciferase report assays, while the binding of USP9X and SMAD1 was confirmed by co-immunoprecipitation (Co-IP). Our studies found that the expression of RUNX1 was upregulated in LF mice, and RUNX1 knockdown alleviated CCl4-induced LF. RUNX1 silencing reduced the viability and migration of HSCs. Besides, RUNX1, as a transcription factor, bound to the promoter of USP9X and regulated the expression of USP9X. USP9X is a deubiquitination enzyme and was found to be up-regulated in LF mice. USP9X silencing reduced the viability and migration of HSCs, thereby inhibiting LF. Further studies showed that USP9X could stabilize downstream Smad1 expression. Furthermore, we also found that RUNX1 regulated the expression of SMAD1 by transcriptionally activating the expression of USP9X, thereby regulating the activation of hepatic stellate cells and liver fibrosis.

miR-125b acts as anti-fibrotic therapeutic target through regulating Gli3 in vivo and in vitro

INTRODUCTION AND OBJECTIVES

Liver fibrosis is a major characteristic of most chronic liver diseases which leads to accumulation of extracellular matrix (ECM) proteins. Hedgehog (Hh) pathway activated by Gli genes participated in the pathogenesis of liver fibrosis. However, the regulatory role of miR-125b in liver fibrosis via targeting Gli genes remains unknown.

MATERIALS AND METHODS

RT-qPCR and western blot were employed to the expression levels of mRNA and protein, respectively. The fibrosis level of liver tissue was determined by Masson's trichrome staining. The interaction between miR-125b and Gli3 was tested by luciferase reporter assay. In addition, LX2 cells were activated and CCl₄-induced rat model was used in this study.

RESULTS

miR-125b was significantly declined in serum samples of the clinical liver fibrosis patient, activated LX2 cells and the liver tissues of the CCl₄-induced rat model. Furthermore, in cellular level, the alpha-smooth muscle actin (α-SMA) and Albumin expressions were ascending and descending in LX2 cells, respectively, with the decline of miR-125b. However, when transfecting with miR-125b mimic, the expressions of α-SMA and Albumin was reversed and Gli3 expression was notably repressed in LX2 cells. The target interaction between miR-125b and Gli3 was determined by dual-luciferase assays. It was further discovered that the changes of α-SMA, Albumin, and Gli3 were similar to the expression trend in LX2 cells with miR-125b mimic transfection.

CONCLUSION

These results suggested that miR-125b might be protective against liver fibrosis via regulating Gli3 and it might be a promising target in the development of novel therapies to treat pathological fibrotic disorders.

Two-Dimensional-Shear Wave Elastography with a Propagation Map: Prospective Evaluation of Liver Fibrosis Using Histopathology as the Reference Standard

Objective

The aim of this study was to prospectively evaluate whether liver stiffness (LS) assessments, obtained by two-dimensional (2D)-shear wave elastography (SWE) with a propagation map, can evaluate liver fibrosis stage using histopathology as the reference standard.

Materials and Methods

We prospectively enrolled 123 patients who had undergone percutaneous liver biopsy from two tertiary referral hospitals. All patients underwent 2D-SWE examination prior to biopsy, and LS values (kilopascal [kPa]) were obtained. On histopathologic examination, fibrosis stage (F0–F4) and necroinflammatory activity grade (A0–A4) were assessed. Multivariate linear regression analysis was performed to determine the significant factors affecting the LS value. The diagnostic performance of the LS value for staging fibrosis was assessed using receiver operating characteristic (ROC) analysis, and the optimal cut-off value was determined by the Youden index.

Results

Reliable measurements of LS values were obtained in 114 patients (92.7%, 114/123). LS values obtained from 2D-SWE with the propagation map positively correlated with the progression of liver fibrosis reported from histopathology (p < 0.001). According to the multivariate linear regression analysis, fibrosis stage was the only factor significantly associated with LS (p < 0.001). The area under the ROC curve of LS from 2D-SWE with the propagation map was 0.773, 0.865, 0.946, and 0.950 for detecting F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The optimal cut-off LS values were 5.4, 7.8, 9.4, and 12.2 kPa for F ≥ 1, F ≥ 2, F ≥ 3, and F = 4, respectively. The corresponding sensitivity and specificity of the LS value for detecting cirrhosis were 90.9% and 88.4%, respectively.

Conclusion

The LS value obtained from 2D-SWE with a propagation map provides excellent diagnostic performance in evaluating liver fibrosis stage, determined by histopathology.

Fibrosis reversal after hepatitis C virus elimination

PURPOSE OF REVIEW

Hepatitis C virus (HCV) infection has been the leading cause of cirrhosis in the United States now for the last several decades. With the introduction of highly effective direct acting antiviral (DAA) drugs, cure rates are now almost 100%. With this explosion of effective therapy, it is possible that many patients with HCV may have reversion in fibrosis. The purpose of this review is, therefore, to report on recent findings in this field.

RECENT FINDINGS

Older data that examined the effect of interferon-based HCV therapy indicate that fibrosis reverses after HCV eradication. More recent work in the DAA era similarly indicates that fibrosis is reversible. A caveat is that DAA therapy causes rapid viral clearance, and appears to lead to rapid reductions in inflammation. Some tools (such as transient elastography), which may also reflect the inflammatory response, and thus may 'overestimate' of fibrosis reversal. However, emerging data suggesting improved outcomes in patients with cirrhosis after HCV clearance support the concept that even cirrhosis reverses in some patients.

SUMMARY

Fibrosis (and cirrhosis) reversion, to some extent, occurs after HCV clearance. This topic is vitally important and information continues to emerge; more data on this subject are expected and needed.

Are we any closer to treating liver fibrosis (and if no, why not)?

This review provides a personal view on anti-fibrosis therapy in the liver. The worst clinical consequence of liver fibrosis is the development of liver cirrhosis and portal hypertension. Etiology is a decisive factor which determines patterns of fibrous septa and subsequent vascular remodeling, which is essential for the development of portal hypertension. Removing or controlling the disease-causing agent, i.e. anti-viral treatment for hepatitis, is the essential first step for treating chronic liver diseases and can reverse fibrosis in some settings. However, removing etiology is not always sufficient to prevent fibrosis from progressing towards cirrhosis and portal hypertension. In liver diseases such as severe alcoholic hepatitis and massive parenchymal loss, the formation of vascular anastomoses between portal to central veins based on bridging fibrosis results in cirrhosis and portal hypertension. For these patients, anti-fibrotic treatment is crucial and urgent. Unfortunately, a lack of understanding how fibrosis contributes to vascular remodeling caused by and combined with a lack of suitable experimental models that recapitulate human liver diseases, has hampered the development of successful anti-fibrotic drugs for clinical use to date.

Assessment of liver fibrosis in chronic hepatitis: comparison of shear wave elastography and transient elastography

PURPOSE

To evaluate the diagnostic accuracy of shear wave elastography (SWE) and transient elastography (TE) in the evaluation of liver fibrosis in chronic hepatitis B (CHB) and C (CHC) patients taking liver biopsy as gold standard.

METHODS

Ethics committee approved this prospective cross-sectional study. Between October 2012 and December 2014, consecutive CHB/CHC patients fulfilling the inclusion criteria were included-age more than 18 years, informed written consent, willing and suitable for liver biopsy. SWE, TE, and biopsy were performed the same day. Liver stiffness measurement (LSM) cut-offs for various stages of fibrosis were generated for SWE and TE. AUC, sensitivity, specificity, and positive/negative predictive values were estimated individually or in combination.

RESULTS

CH patients (n = 240, CHB 172, CHC 68), 176 males, 64 females, mean age 32.6 ± 11.6 years were enrolled. Mean LSM of patients with no histological fibrosis (F0) was 5.0 ± 0.7 and 5.1+1.4 kPa on SWE and TE, respectively. For differentiating F2 and F3-4 fibrosis on SWE, at 7.0 kPa cut-off, the sensitivity was 81.3% and specificity 77.6%. For TE, at 8.3 kPa cut-off, sensitivity was 81.8% and specificity 83.1%. For F3 vs. F4, SWE sensitivity was 83.3% and specificity 90.7%. At 14.8 kPa cut-off, TE showed similar sensitivity (83.3%) but specificity increased to 96.5%. Significant correlation between SWE and TE was observed (r = 0.33, p < 0.001). On combining SWE and TE, a drop in sensitivity with increased specificity for all stages of liver fibrosis occured.

CONCLUSION

SWE is an accurate technique for evaluating liver fibrosis. SWE compares favorably with TE especially for predicting advanced fibrosis/cirrhosis. Combining SWE and TE further improves specificity.

Atypical Chemokine Receptor 1 polymorphism cannot be used as an indicator of liver fibrosis progression in Hepatitis C virus positive patients

Background & Objective:

Atypical chemokine receptor 1(ACKR1) represents an atypical chemokine receptor that can bind promiscuously to various chemokines. Chemokines play a crucial role to recruit leukocyte subsets migration through the endothelium and into liver against the virus during the progression of hepatitis C virus (HCV) infection. Most HCV positive patients can lead to liver fibrosis. Hyaluronic acid (HA), laminin (LN), collagen IV(C-IV) and amino-terminal pro-peptide of Type-III pro-collagen (PIII NP) are indices of the extent of liver fibrosis. The aim of this study was to investigate the association between ACKR1 polymorphism and liver fibrosis with these four serum liver markers in HCV positive patients.

Methods:

From April 2015 to December 2015, a total of 210 patients (109 males and 101 females) with chronic HCV infection at Dalian Infectious Hospital were recruited to participate in this study. ACKR1 genotyping was using TaqMan probes method. HA, LN, C-IV and PIII NP were detected by using diagnostic kits.

Results:

We compared serum levels of HA, LN, C-IV and PIII NP between FY^*A/FY^*A and FY^*A/FY^*B patients and the differences were not significant (P=0.905, P=0.298, P=0.880 and P=0.470, respectively).

Conclusions:

This study has attempted to elucidate the role of ACKR1 polymorphism in liver fibrosis progression of HCV infection, our results demonstrated that ACKR1 polymorphism is not directly associated with the fibrogenesis in HCV positive patients.

Hepatic Stellate Cells in Liver Fibrosis and siRNA-Based Therapy

Hepatic fibrosis is a reversible wound-healing response to either acute or chronic liver injury caused by hepatitis B or C, alcohol, and toxic agents. Hepatic fibrosis is characterized by excessive accumulation and reduced degradation of extracellular matrix (ECM). Excessive accumulation of ECM alters the hepatic architecture leading to liver fibrosis and cirrhosis. Cirrhosis results in failure of common functions of the liver. Hepatic stellate cells (HSC) play a major role in the development of liver fibrosis as HSC are the main source of the excessive production of ECM in an injured liver. RNA interference (RNAi) is a recently discovered therapeutic tool that may provide a solution to manage multiple diseases including liver fibrosis through silencing of specific gene expression in diseased cells. However, gene silencing using small interfering RNA (siRNA) is encountering many challenges in the body after systemic administration. Efficient and stable siRNA delivery to the target cells is a key issue for the development of siRNA therapeutic. For that reason, various viral and non-viral carriers for liver-targeted siRNA delivery have been developed. This review will cover the current strategies for the treatment of liver fibrosis as well as discussing non-viral approaches such as cationic polymers and lipid-based nanoparticles for targeted delivery of siRNA to the liver.

Reversal effect of Jagged1 signaling inhibition on CCl4-induced hepatic fibrosis in rats

The role of the Notch ligand Jagged1 in hepatic fibrosis remains to be elucidated. In the current study, we investigated the role of Jagged1 in the activation of hepatic stellate cells (HSCs) and development of hepatic fibrosis in rats. In vitro, Jagged1 in HSCs was downregulated and upregulated by Jagged1 siRNA and pcDNA3.1 Jagged1, respectively. The levels of epithelial-mesenchymal transition (EMT) markers and HSC activation markers were assessed using western blot analysis. The proliferation and migration capacity of HSCs were assessed using 5-ethynyl-2′-deoxyuridine (EdU) incorporation and Transwell migration assays. In vivo, a recombinant adeno-associated virus type 1 (rAAV1) vector carrying Jagged1 shRNA (rAAV1-Jagged1-shRNA) was constructed and transferred to rat livers via the tail vein. Reversion of liver fibrosis and the effect of Jagged1 signaling on EMT were studied using pathological, immunohistochemical and immunofluorescence methods. Our findings revealed that downregulation and upregulation of Jagged1 inhibited and promoted, respectively, HSC activation. The migratory capacity of HSCs was markedly restrained by Jagged1 siRNA. Furthermore, downregulation of Jagged1 suppressed EMT in HSCs. rAAV1-Jagged1-shRNA was generated to treat CCl4-induced hepatic fibrosis in rats. Treatment with rAAV1-Jagged1-shRNA reversed hepatic fibrosis by decreasing EMT. The results of the present study suggest that inhibition of Jagged1 is a potential treatment to ameliorate liver fibrosis.

Insulin-Like Growth Factor-1 Deficiency and Cirrhosis Establishment

Cirrhosis represents the final stage of chronic liver damage, which can be due to different factors such as alcohol, metabolic syndrome with liver steatosis, autoimmune diseases, drugs, toxins, and viral infection, among others. Nowadays, cirrhosis is an important health problem and it is an increasing cause of morbidity and mortality, being the 14th most common cause of death worldwide. The physiopathological pathways that lead to fibrosis and finally cirrhosis partly depend on the etiology. Nevertheless, some common features are shared in this complex mechanism. Recently, it has been demonstrated that cirrhosis is a dynamic process that can be altered in order to delay or revert fibrosis. In addition, when cirrhosis has been established, insulin-like growth factor-1 (IGF-1) deficiency or reduced availability is a common condition, independently of the etiology of chronic liver damage that leads to cirrhosis. IGF-1 deprivation seriously contributes to the progressive malnutrition of cirrhotic patient, increasing the vulnerability of the liver to establish an inflammatory and oxidative microenvironment with mitochondrial dysfunction. In this context, IGF-1 deficiency in cirrhotic patients can justify some of the common characteristics of these individuals. Several studies in animals and humans have been done in order to test the replacement of IGF-1 as a possible therapeutic option, with promising results.

Liver Fibrosis Reversion After Suppression of Hepatitis B Virus

Great strides have been made in hepatitis B virus (HBV)-related fibrosis and cirrhosis. Available evidence indicates that HBV viral suppression causes regression of advanced fibrosis and even cirrhosis, and therefore should be attempted in all patients with advanced fibrosis and cirrhosis. The preferred agents in patients with cirrhosis are entecavir and tenofovir, primarily because the risk of breakthrough is low. HBV viral suppression leads to improved clinical outcomes even in patients with cirrhosis and complications. The risk of hepatocellular carcinoma is reduced, but not eliminated. Thus, patients with HBV cirrhosis should continue to have routine screening for hepatocellular carcinoma, even after viral suppression.

Renin-angiotensin system inhibitors and fibrosis in chronic liver disease: a systematic review

BACKGROUND AND AIMS

The renin-angiotensin system (RAS) has an important role in hepatic fibrosis and portal hypertension. RAS inhibitors are already accepted in clinical fields for antihypertensive management, but their effects on hepatic fibrosis are controversial. The aim of this study was to systematically review the effects of RAS inhibitors on hepatic fibrosis based on histological assessment.

METHODS

We performed a systematic review and meta-analysis (MA) of the literature using the Ovid-MEDLINE, EMBASE, and Cochrane Library databases (up to January 2015) to identify clinical studies evaluating the effects of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers on hepatic fibrosis or cirrhosis patients based on histological assessment. Of the 455 studies identified, we analyzed 7, including a total of 1066 patients, which met our selection criteria.

RESULTS

According to the MA, patients treated with RAS inhibitors had significantly lower fibrosis scores (SMD -0.68, 95 % CI -1.03, -0.34, I (2) = 0 %, p < 0.0001) and smaller fibrosis areas (SMD -0.80, 95 % CI -1.18, -0.41, I (2) = 0 %, p < 0.0001) than controls. Serum fibrosis markers such as TGF-β1, collagen I, IV, TIMP-1, and MMP2 were significantly reduced in the intervention group. In two studies, mean arterial pressures were significantly decreased in RAS inhibitor users, but there were no reports about symptoms related to decreased blood pressure. No significant difference was found in serum creatinine levels between the intervention and control groups, and significant renal dysfunction was not observed after administration of RAS inhibitors.

CONCLUSIONS

RAS inhibitors are potential therapeutic agents for hepatic fibrosis, which can be safely used in patients with chronic liver disease.

Non-invasive detection of liver fibrosis: MR imaging features vs. MR elastography

PURPOSE

To compare accuracy of morphological features of liver on MRI and liver stiffness with MR elastography (MRE) for detection of significant liver fibrosis and cirrhosis.

MATERIALS AND METHODS

In this retrospective study, we evaluated 62 patients who underwent liver MRI with MRE and histological confirmation of liver fibrosis within 6 months. Two radiologists, blinded to histology results, independently evaluated liver parenchyma texture, surface nodularity, signs of volumetric changes, and portal hypertension for presence of significant fibrosis and cirrhosis. Two more readers independently calculated mean liver stiffness values with MRE. Interobserver agreement was evaluated with kappa and intra-class correlation coefficient (ICC) analysis. Diagnostic accuracy was assessed with area under receiver operating characteristic (AUROC) analysis. Comparison of AUROCs of MRI and MRE was performed.

RESULTS

Liver fibrosis was present in 37 patients. The interobserver agreement was poor to good (κ = 0.12-0.74) for MRI features and excellent for MRE (ICC 0.97, 95% CI 0.95-0.98). MRI features had 48.5%-87.9% sensitivity, 55.2%-100% specificity, and 71.5%-81.6% accuracy/for detection of significant fibrosis. MRE performed better with 100% sensitivity, 96.5% specificity, and 98.9% accuracy. For the detection of cirrhosis, MRE performed better than MRI features with 88.2% sensitivity (vs. 41.2%-82.3%), 91.1% specificity (vs. 64.4%-95.6%), and 93.5% accuracy (vs. 60.6%-80.5%). Among the MRI features, surface nodularity and overall impression had the best accuracies of 80.3% and 81.6% for detection of significant fibrosis, respectively. For cirrhosis, parenchyma texture and overall impression had the best accuracies of 80.5% and 79.7%, respectively. Overall, MRE had significantly greater AUROC than MRI features for detection of both significant fibrosis (0.98.9 vs 0.71-0.82, P < 0.001) and cirrhosis (0.93.5 vs. 0.61-0.80.5, P < 0.01).

CONCLUSION

MRE is superior to MRI for the non-invasive diagnosis of significant liver fibrosis and cirrhosis.

Role of Smad3 in platelet-derived growth factor-C-induced liver fibrosis

Chronic liver injury leads to fibrosis and cirrhosis. Cirrhosis, the end stage of chronic liver disease, is a leading cause of death worldwide and increases the risk of developing hepatocellular carcinoma. Currently, there is a lack of effective antifibrotic therapies to treat fibrosis and cirrhosis. Development of antifibrotic therapies requires an in-depth understanding of the cellular and molecular mechanisms involved in inflammation and fibrosis after hepatic injury. Two growth factor signaling pathways that regulate liver fibrosis are transforming growth factor-β (TGFβ) and platelet-derived growth factor (PDGF). However, their specific contributions to fibrogenesis are not well understood. Using a genetic model of liver fibrosis, we investigated whether the canonical TGFβ signaling pathway was necessary for fibrogenesis. PDGF-C transgenic (PDGF-C Tg) mice were intercrossed with mice that lack Smad3, and molecular and histological fibrosis was analyzed. PDGF-C Tg mice that also lacked Smad3 had less fibrosis and improved liver lobule architecture. Loss of Smad3 also reduced expression of collagen genes, which were induced by PDGF-C, but not the expression of genes frequently associated with hepatic stellate cell (HSC) activation. In vitro HSCs isolated from Smad3-null mice proliferated more slowly than cells from wild-type mice. Taken together, these findings indicate that PDGF-C activates TGFβ/Smad3 signaling pathways to regulate HSC proliferation, collagen production and ultimately fibrosis. In summary, these results suggest that inhibition of both PDGF and TGFβ signaling pathways may be required to effectively attenuate fibrogenesis in patients with chronic liver disease.

Short-Term Repeatability of Magnetic Resonance Elastography at 3.0T: Effects of Motion-Encoding Gradient Direction, Slice Position, and Meal Ingestion

PURPOSE

Magnetic resonance elastography (MRE) can estimate liver stiffness (LS) noninvasively. We prospectively assessed whether motion-encoding gradient (MEG) direction, slice position, or high-caloric food intake affects the repeatability of MRE measurements of LS.

MATERIALS AND METHODS

Twenty healthy volunteers (8 women, 12 men; age, 48 ± 12 years) were imaged in a 3.0T scanner at four timepoints: twice after overnight fasting (B1 , B2 ) and twice after consuming a 1050-calorie standardized meal (A1 , A2 ; after 30 and 60 min, respectively). Each session comprised sequential MRE acquisitions in which MEG was applied in three orthogonal directions with three slices positioned over the liver for each. Between sessions, the participants were repositioned to assess test-retest reproducibility.

RESULTS

The LS measurements before/after food intake were 3.36 ± 1.31 kPa/3.22 ± 1.03 kPa, 2.04 ± 0.33 kPa/2.27 ± 0.38 kPa, and 2.47 ± 0.50 kPa/2.64 ± 0.76 kPa for MEG superimposed along the anterior-posterior (AP), foot-head (FH), and right-left (RL) directions, respectively. Before and after food intake, LS estimates were lower and more reproducible (<10% coefficient of variation) when the MEG was in the FH direction, not the AP or RL direction. Liver stiffness estimates were significantly elevated after meal consumption when the MEG was in the FH direction (P < 0.05 for B1 vs. A1 , B1 vs. A2 , B2 vs. A1 , and B2 vs. A2 ).

CONCLUSION

MRE estimates of LS were highly reproducible, particularly when MEG was applied in the FH direction, suggesting that this method could be used for long-term monitoring of antifibrotic therapy without repeated biopsies. High-caloric food intake resulted in slightly elevated LS on MRE.

Cyclin-dependent kinases, control of cell cycle and hepatic fibrosis

Multiple etiologies of liver disease lead to liver fibrosis by driving the activation of hepatic stellate cells (HSCs) into a myofibroblast-like phenotype that is contractile, proliferative and fibrogenic. Liver fibrosis is associated with the proliferation of HSCs, and the cell cycle of activated HSCs is abnormal. Cyclin-dependent kinases (CDKs) play essential roles in cell proliferation. However, the molecular mechanisms responsible for the abnormal proliferation of activated HSCs during hepatic fibrogenesis remain to be defined. Here we will review recent progress in understanding the associations among CDKs, the control of cell cycle and hepatic fibrosis, with an aim to reveal the potential mechanisms of hepatic fibrosis.

Translating an understanding of the pathogenesis of hepatic fibrosis to novel therapies

The response to injury is one of wound healing and fibrogenesis, which ultimately leads to fibrosis. The fibrogenic response to injury is a generalized one across virtually all organ systems. In the liver, the injury response, typically occurring over a prolonged period of time, leads to cirrhosis (although it should be pointed out that not all patients with liver injury develop cirrhosis). The fact that many different diseases result in cirrhosis suggests a common pathogenesis. The study of hepatic fibrogenesis over the past 2 decades has been remarkably active, leading to a considerable understanding of this process. It clearly has been shown that the hepatic stellate cell is a central component in the fibrogenic process. It also has been recognized that other effector cells are important in the fibrogenic process, including resident fibroblasts, bone marrow-derived cells, fibrocytes, and even perhaps cells derived from epithelial cells (ie, through epithelial to mesenchymal transition). A key aspect of the biology of fibrogenesis is that the fibrogenic process is dynamic; thus, even advanced fibrosis (or cirrhosis) is reversible. Together, an understanding of the cellular basis for liver fibrogenesis, along with multiple aspects of the basic pathogenesis of fibrosis, have highlighted many exciting potential therapeutic opportunities. Thus, although the most effective antifibrotic therapy is simply treatment of the underlying disease, in situations in which this is not possible, specific antifibrotic therapy is likely not only to become feasible, but will soon become a reality. This review highlights the mechanisms underlying fibrogenesis that may be translated into future antifibrotic therapies and to review the current state of clinical development.

MR elastography of healthy liver parenchyma: Normal value and reliability of the liver stiffness value measurement

PURPOSE

To investigate the normal liver stiffness value using MR elastography (MRE) and to compare the repeatability and reproducibility of three measurement methods.

MATERIALS AND METHODS

Forty-nine subjects who underwent liver MR imaging including elastography using a 1.5 Tesla scanner, who had normal laboratory test results, and who underwent liver donation, were included in this study. Two, independent readers measured the liver stiffness value of the hepatic parenchyma using three methods, including evaluating various liver parenchyma portions using different-sized, regions-of-interest (ROIs): 2cm-ROI-per-slice in the right lobe (2cm-per-slice); 1cm-ROI-per-segment (1cm-S); and 70%-of-the-surface area (70% S). The mean liver stiffness values were compared between gender using the t-test and among the age groups using one-way analysis of variance. The reproducibility and repeatability of the three liver stiffness value measurement methods were determined using intraclass correlation coefficients (ICCs) and the 95% Bland-Altman limits of agreement.

RESULTS

The liver stiffness values in living liver donors ranged from 1.54 to 2.87 kPa. The mean stiffness value was 2.05 kilopascal using the 2cm-per-slice method, 2.01 kilopascal with the 1cm-S method and 2.12 kilopascal using the 70% S method. There was no significant difference in the liver stiffness value according to the gender or age factors. For reproducibility, the ICCs were 0.416 with the 2cm-per-slice method, 0.800 using the 1cm-S method, and 0.845 with the 70% S method. In terms of repeatability, the ICCs were 0.238 using the 2cm-per-slice method, 0.914 with the 1cm-S method, and 0.852 using the 70% S method. The ICCs determined using the 2cm-per-slice method were significantly lower than those of the 1cm-S or 70% S method for assessing both reproducibility and repeatability. The 95% limit of agreement was 54.0% with the 2cm-per-slice method, 24.0% using the 1cm-S method, and 18.8% with the 70% S method, in terms of reproducibility. To assess the repeatability, the 95% limit of agreement was 63.3% using the 2cm-per-slice method, 20.6% with the 1cm-S method, and 17.4% using the 70% S method.

CONCLUSION

The mean liver stiffness values in living donors ranged from 2.05 to 2.12 kilopascals and did not differ significantly for either gender or age. The 1cm-S and 70% S methods were significantly more reliable compared with the 2cm-per-slice method.

A taxonomy of organ-specific breast cancer metastases based on a protein-protein interaction network

We carried out a systems-level study of the mechanisms underlying organ-specific metastases of breast cancer. We followed a network-based approach using microarray expression data from human breast cancer metastases to select organ-specific proteins that exert a range of functions allowing cell survival and growth in the microenvironment of distant organs. MinerProt, a home-made software application, was used to group organ-specific signatures of brain (1191 genes), bone (1623 genes), liver (977 genes) and lung (254 genes) metastases by function and select the most differentially expressed gene in each function. As a result, we obtained 19 functional representative proteins in brain, 23 in bone, 15 in liver and 9 in lung, with which we constructed four organ-specific protein-protein interaction networks. The network taxonomy included seven proteins that interacted in brain metastasis, which were mainly associated with signal transduction. Proteins related to immune response functions were bone specific, while those involved in proteolysis, signal transduction and hepatic glucose metabolism were found in liver metastasis. No experimental protein-protein interaction was found in lung metastasis; thus, computationally determined interactions were included in this network. Moreover, three of these selected genes (CXCL12, DSC2 and TFDP2) were associated with progression to specific organs when tested in an independent dataset. In conclusion, we present a network-based approach to filter information by selecting key protein functions as metastatic markers or therapeutic targets.

Effects of Angiotensin Converting Enzyme Inhibitors on Liver Fibrosis in HIV and Hepatitis C Coinfection

Background. Liver fibrosis is accelerated in HIV and hepatitis C coinfection, mediated by profibrotic effects of angiotensin. The objective of this study was to determine if angiotensin converting enzyme inhibitors (ACE-Is) attenuate liver fibrosis in coinfection. Methods. A retrospective review of 156 coinfected subjects was conducted to analyze the association between exposure to ACE-Is and liver fibrosis. Noninvasive indices of liver fibrosis (APRI, FIB-4, Forns indices) were compared between subjects who had taken ACE-Is and controls who had not taken them. Linear regression was used to evaluate ACE-I use as an independent predictor of fibrosis. Results. Subjects taking ACE-Is for three years were no different than controls on the APRI and the FIB-4 but had significantly higher scores than controls on the Forns index, indicating more advanced fibrosis. The use of ACE-Is for three years remained independently associated with an elevated Forns score when adjusted for age, race, and HIV viral load (P < 0.001). There were significant associations between all of the indices and significant fibrosis, as determined clinically and radiologically. Conclusions. There was not a protective association between angiotensin inhibition and liver fibrosis in coinfection. These noninvasive indices may be useful for ruling out significant fibrosis in coinfection.

Protective effects of allopurinol against acute liver damage and cirrhosis induced by carbon tetrachloride: modulation of NF-κB, cytokine production and oxidative stress

BACKGROUND

The aim of this work was to evaluate the hepatoprotective ability of allopurinol to prevent the liver injury induced by carbon tetrachloride (CCl(4)).

METHODS

Acute liver damage was induced with CCl(4) (4g/kg, by gavage); allopurinol (50mg/kg, by gavage) was given 1h before and 1h after CCl(4) intoxication and two daily doses for the previous three days. Cirrhosis was established by CCl(4) administration (0.4g/kg, i. p. three times a week, eight weeks); allopurinol was administered (100mg/kg, by gavage, daily) during the long-term of CCl(4) treatment. Alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GTP), xanthine oxidase (XO), lipid peroxidation, reduced and oxidized glutathione (GSH, GSSG, respectively), hydroxyproline and histopathologycal analysis were performed. Nuclear factor-κB (NF-κB), pro-inflammatory and anti-inflammatory cytokines, transforming growth factor-β (TGF-β) and metalloproteinase-13 (MMP-13) were analyzed by Western blots.

RESULTS

Acute injury increased ALT and γ-GTP activities, additionally enhanced NF-κB nuclear translocation and cytokines production such as tumor necrosis factor-α, interleukine-1β, and interleukine-6. Allopurinol partially prevented these effects, while increased interleukine-10. Acute and chronic CCl(4) treatments altered the levels of XO activity, lipid peroxidation, and GSH/GSSG ratio, while these remained within normal range with allopurinol administration. Necrosis, fibrosis and TGF-β production induced in chronic injury were partially prevented by allopurinol, interestingly, this drug induced MMP-13 activity.

CONCLUSIONS

Allopurinol possesses antioxidant, anti-inflammatory and antifibrotic properties, probably by its capacity to reduce NF-κB nuclear translocation and TGF-β expression, as well as to induce MMP-13. General significance Allopurinol might be effective treatment of liver diseases.

Role of integrins in fibrosing liver diseases

Integrins and other cell adhesion molecules regulate numerous physiological and pathological mechanisms by mediating the interaction between cells and their extracellular environment. Although the significance of integrins in the evolution and progression of certain cancers is well recognized, their involvement in nonmalignant processes, such as organ fibrosis or inflammation, is only beginning to emerge. However, accumulating evidence points to an instrumental role of integrin-mediated signaling in a variety of chronic and acute noncancerous diseases, particularly of the liver.

Development of a large animal model of cirrhosis and portal hypertension using hepatic transarterial embolization: a study in swine

PURPOSE

To develop a clinically relevant porcine model of liver cirrhosis with portal hypertension by means of hepatic transarterial embolization.

MATERIALS AND METHODS

Institutional animal care and use committee approval was obtained for all experiments. Pigs received transcatheter arterial infusion of a 3:1 mixture of iodized oil and ethanol into the hepatic artery in volumes of 16 mL in group 1 (n = 4), 28 mL in group 2 (n = 4), and 40 mL in group 3 (n = 4) with intent of bilobar distribution. Hepatic venous pressure gradient (HVPG) measurement, liver function tests, and volumetry were performed at baseline, at 2 weeks, and before necropsy.

RESULTS

Cirrhosis was successfully induced in three animals that received 16 mL of the embolic mixture and in all four animals that received 28 mL. The animals in the 40-mL group did not recover from the procedure and were euthanized within 48 h. Increases in HVPG after 6-8 weeks versus baseline reached statistical significance (P < .05). Correlation between degree of fibrosis and volume of embolic agent did not reach statistical significance, but there was a trend toward increased fibrosis in the 28-mL group compared with the 16-mL group.

CONCLUSIONS

Transcatheter hepatic arterial embolization can be used to create a reliable and reproducible porcine model of liver cirrhosis and portal hypertension.

Long-term antifibrotic action of interferon-γ treatment in patients with chronic hepatitis B virus infection

BACKGROUND

The first priority in treating fibrosis is to eliminate the causes that result in liver injury, e.g., hepatitis B and C virus. However, in many liver diseases the cause is either unknown or untreatable. The present study was designed to investigate the long-term antifibrotic effect of interferon-gamma (IFN-gamma) treatment in patients chronically infected with hepatitis B virus.

METHODS

A total of 42 patients, 30 treated with IFN-gamma and 12 controls, were enrolled from an original clinical trial (Clin Gastroenterol Hepatol 2005;3:819.). Three serial liver biopsies that were obtained at the initiation and end of IFN-gamma treatment as well as 4 to 6 years after treatment discontinuation were assessed according to the modified Chevallier scoring system.

RESULTS

Twenty-five out of 30 IFN-gamma-treated patients were followed up until 4 to 6 years after the treatment was stopped. However, all controls were excluded from follow-up due to death, loss and elevated virus level within 2 years. Twenty-five IFN-gamma-treated patients had stable serum liver function and liver fibrosis indices without any further anti-viral or anti-fibrotic treatment. Improved inflammatory and fibrotic scores were found after nine months of IFN-gamma treatment according to the modified Chevallier scoring system (inflammation: 11.8+/-6.5 at the beginning of IFN-gamma treatment vs. 9.2+/-4.1 after 9 months, P<0.05; fibrosis: 15.0+/-7.3 at baseline vs. 12.6+/-6.8 after 9 months, P<0.05). Among them, 14 patients accepted a third serial liver biopsy 4 to 6 years after treatment discontinuation, and the fibrotic score was increased (14.2+/-8.3 vs. 11.9+/-7.6 after 9 months, P<0.05).

CONCLUSIONS

Nine-month IFN-gamma treatment significantly improves the fibrosis score in patients with chronic HBV infection. The majority of patients demonstrate stable serum biochemical indices and quality of life. However, they do not show a long-term benefit according to histological criteria. Given the limited sample size, long-term IFN-gamma treatment regimens should be assessed in further clinical trials.

N-methyl-4-isoleucine cyclosporine attenuates CCl -induced liver fibrosis in rats by interacting with cyclophilin B and D

BACKGROUND AND AIM

N-methyl-4-isoleucine cyclosporine (NIM811), a new analogue of cyclosporine A, can inhibit collagen deposition in vitro and reduce liver necrosis in a bile-duct-ligation animal model. However, whether NIM811 effects on CCl(4) -induced rat liver fibrosis, and the related mechanism has not been determined.

METHODS

A liver fibrosis model was induced in Wistar rats using CCl(4) for 6 weeks. Meanwhile, two different doses of NIM811 (low-dose 10 mg/kg and high-dose 20 mg/kg) were given to the CCl(4) -treated rats. Liver fibrosis was then evaluated according to histopathological scoring and liver hydroxyproline content. Serum alanine aminotransferase, aspartate aminotransferase and albumin levels, expression of matrix metalloproteinase-13, tissue inhibitor of metalloproteinase-1, α-smooth muscle actin and cyclophilin B and D in liver tissue were determined. Cyclophilin B and D were also studied in an hepatic stellate cell line.

RESULTS

Hydroxyproline content was decreased in both NIM811 groups compared with the model (P < 0.05). Liver necrosis and fibrosis were also attenuated in the NIM811 groups. NIM811 suppressed the expression of tissue inhibitor of metalloproteinase-1, transforming growth factor beta mRNA and α-smooth muscle actin protein in liver tissue. Expression of cyclophilin B in the fibrosis model was increased compared with the normal group (P < 0.05), and was decreased significantly in the low-dose NIM811 treatment group (P < 0.05), which indicated that cyclophilin B might have a profibrotic effect. In vitro studies revealed that cyclophilin B and/or D knockout were associated with collagen inhibition.

CONCLUSIONS

NIM811 attenuates liver fibrosis in a CCl(4)-induced rat liver fibrosis model, which may be related to binding with cyclophilin B and D.

[Reversibility of hepatitis B virus-induced liver cirrhosis after prolonged antiviral therapy]

Reversibility of liver fibrosis or cirrhosis involves complete restoration of normal liver architecture. This phenomenon has been well documented in chronic liver diseases such as autoimmune hepatitis, biliary obstruction, hemochromatosis, nonalcoholic steatohepatitis, and viral hepatitis. There are very few reports of reversal of cirrhosis after antiviral therapy in patients with chronic hepatitis B virus (HBV) infection. We report a case of disappearance of HBV-induced liver cirrhosis after years of treatment with distinct antiviral drugs, documented by successive biopsy results. This disappearance was accompanied by normalization of platelet count, gammaglobulin titers, and radiologic findings.

Colchicine reduces procollagen III and increases pseudocholinesterase in chronic liver disease

AIM: To test whether colchicine would be an effective antifibrotic agent for treatment of chronic liver diseases in patients who could not be treated with α-interferon.

METHODS: Seventy-four patients (46 males, 28 females) aged 40-66 years (mean 53 ± 13 years) participated in the study. The patients were affected by chronic liver diseases with cirrhosis which was proven histologically (n = 58); by chronic active hepatitis C (n = 4), chronic active hepatitis B (n = 2), and chronic persistent hepatitis C (n = 6). In the four patients lacking histology, cirrhosis was diagnosed from anamnesis, serum laboratory tests, esophageal varices and ascites. Patients were assigned to colchicine (1 mg/d) or standard treatment as control in a randomized, double-blind trial, and followed for 4.4 years with clinical and laboratory evaluation.

RESULTS: Survival at the end of the study was 94.6% in the colchicine group and 78.4% in the control group (P = 0.001). Serum N-terminal peptide of type III procollagen levels fell from 34.0 to 18.3 ng/mL (P = 0.0001), and pseudocholinesterase levels rose from 4.900 to 5.610 mU/mL (P = 0.0001) in the colchicine group, while no significant change was seen in controls. Best results were obtained in patients with chronic hepatitis C and in alcoholic cirrhotics.

CONCLUSION: Colchicine is an effective and safe antifibrotic drug for long-term treatment of chronic liver disease in which fibrosis progresses towards cirrhosis.

Inhibitory effect of antisense oligonucleotide targeting TIMP-2 on immune-induced liver fibrosis

INTRODUCTION

We previously reported that both experimental and human studies have shown the importance of TIMP-1 and TIMP-2 in the development of liver fibrosis, a disease mostly caused by HBV and HCV infection in China. Inhibiting the expression of TIMP-1 by an antisense oligonucleotide (ASON) can prevent liver fibrosis through decreasing the deposition of collagen I and III. Whether blocking the expression of TIMP-2 has the same effect on liver fibrosis is not clear.

MATERIALS AND METHODS

To interfere with this potentially effective target, we designed and synthesized two different ASON targeting TIMP-2, then mixed and transfected them by hydrodynamic injection into the rat livers with immune-induced liver fibrosis. We isolated HSCs from the HSA-induced rat model with liver fibrosis, and transfected them with ASON or sense oligonucleotide in vitro.

RESULTS

We observed that TIMP-2 ASON markedly reduced the expression of TIMP-2 by real-time PCR, Western blot, and enzyme linked immunosorbent assay. However, TIMP-2 ASON had little effect on alpha-SMA expression in vitro by Western blot. Inhibition of the expression of TIMP-2 by TIMP-2 ASON clearly decreased deposition of collagen I and IV, ameliorated liver pathology, and improved the liver function among the rats with immune-induced liver fibrosis.

CONCLUSION

The results suggested that TIMP-2 ASON could prevent the progression of liver fibrosis in this rat model. It is possible that this could form the basis for exploration of new liver anti-fibrosis drugs at a genetic level.

Library of molecular associations: curating the complex molecular basis of liver diseases

Background

Systems biology approaches offer novel insights into the development of chronic liver diseases. Current genomic databases supporting systems biology analyses are mostly based on microarray data. Although these data often cover genome wide expression, the validity of single microarray experiments remains questionable. However, for systems biology approaches addressing the interactions of molecular networks comprehensive but also highly validated data are necessary.

Results

We have therefore generated the first comprehensive database for published molecular associations in human liver diseases. It is based on PubMed published abstracts and aimed to close the gap between genome wide coverage of low validity from microarray data and individual highly validated data from PubMed. After an initial text mining process, the extracted abstracts were all manually validated to confirm content and potential genetic associations and may therefore be highly trusted. All data were stored in a publicly available database, Library of Molecular Associations http://www.medicalgenomics.org/databases/loma/news, currently holding approximately 1260 confirmed molecular associations for chronic liver diseases such as HCC, CCC, liver fibrosis, NASH/fatty liver disease, AIH, PBC, and PSC. We furthermore transformed these data into a powerful resource for molecular liver research by connecting them to multiple biomedical information resources.

Conclusion

Together, this database is the first available database providing a comprehensive view and analysis options for published molecular associations on multiple liver diseases.

Antifibrotic effects of CGX, a traditional herbal formula, and its mechanisms in rats

AIM

CGX is a modification of a traditional herbal medicine for "liver cleaning," which is used to treat various chronic liver disorders in oriental clinics. This study investigated the antifibrotic effects and associated mechanisms of CGX.

MATERIALS AND METHODS

Liver fibrosis was induced in rats by dimethylnitrosamine (DMN; 10 mg kg(-1), ip) injection on 3 consecutive days per week for 4 weeks. CGX (100 or 200 mg kg(-1), po) was administrated once a day for 4 weeks. Three cell lines (HepG2, RAW 264.7, and HSC-T6) were used to examine its mechanisms.

RESULTS

CGX treatment dramatically ameliorated the change in liver and spleen weight and serum albumin (p<0.01), aspartate transaminase (p<0.01), alanine transaminase (p<0.01), alkaline phosphatase (p<0.01), and total bilirubin (p<0.01) levels. Histopathologically, CGX administration decreased necrosis, inflammatory cell infiltration, and collagen accumulation. The antifibrotic effects of CGX were confirmed from hydroxyproline determination and the reduction in the numbers of activated hepatic stellate cells. In addition, antioxidant proteins, glutathione content, and glutathione peroxidase, catalase, and superoxide dismutase activities were maintained in the CGX-treated groups compared with the DMN group. CGX downregulated fibrosis-related genes (inducible nitric oxide synthase, tumor necrosis factor-alpha, transforming growth factor-beta, connective tissue growth factor, and platelet-derived growth factor-beta) and decreased the protein levels of profibrotic cytokines (transforming growth factor-beta and platelet-derived growth factor-beta) in liver tissues. In the cell line-based studies, CGX showed supportive effects, such as the protection of hepatocytes from CCl(4)-toxicity, inhibition of NO production in RAW 264.7 cells, and inactivation of hepatic stellate cells.

CONCLUSION

These results demonstrated the antifibrotic effects of CGX and the corresponding mechanisms associated with sustaining the antioxidative system and inhibiting hepatic stellate cell activation via the downregulation of fibrogenic cytokines.

Proteomics and liver fibrosis: identifying markers of fibrogenesis

Chronic hepatic disease damages the liver and the resulting wound-healing process might lead to liver fibrosis and subsequent cirrhosis development. Fibrosis is the excessive deposition of extracellular matrix (ECM) in the tissue as consequence of chronic liver damage. The fibrotic response triggers almost all of the complications of end-stage liver disease, including portal hypertension, ascites, encephalopathy, synthetic dysfunction and impaired metabolic capacity. Thus, efforts to understand and attenuate fibrosis have direct clinical implications. Reliable, accurate, disease-specific, noninvasive biomarkers of fibrosis and fibrogenesis in order to prevent or minimize the impact of the chronic liver disease progression are a critical need. This review aims to provide an overview of the possibilities that proteome technology can offer to the knowledge, diagnosis and prognosis of liver fibrosis.

Targeting liver fibrosis: strategies for development and validation of antifibrotic therapies

We have made striking progress in our understanding of the biochemistry and cell biology that underlies liver fibrosis and cirrhosis, including the development of strategies and agents to prevent and reverse fibrosis. However, translation of this knowledge into clinical practice has been hampered by (1) the limitation of many in vitro and in vivo models to confirm mechanisms and to test antifibrotic agents, and (2) the lack of sensitive methodologies to quantify the degree of liver fibrosis and the dynamics of fibrosis progression or reversal in patients. Furthermore, whereas cirrhosis and subsequent decompensation are accepted hard clinical endpoints, fibrosis and fibrosis progression alone are merely plausible surrogates for future clinical deterioration. In this review we focus on an optimized strategy for preclinical antifibrotic drug development and highlight the current and future techniques that permit noninvasive assessment and quantification of liver fibrosis and fibrogenesis. The availability of such noninvasive methodologies will serve as the pacemaker for the clinical development and validation of potent antifibrotic agents.

Seropharmacological effects of Yigankang Decoction and its separated recipe on collagen metabolism and transforming growth factor-beta 1 expression in hepatic stellate cells

AIM: To investigate the seropharmacological effects of Yigankang Decoction and its separated recipe on collagen metabolism and transforming growth factor-beta 1 (TGF-β1) expression in hepatic stellate cells (HSCs) and explore the antifibrotic mechanism of Yigankang Decoction.

METHODS: Normal rats and rats with carbon tetrachloride (CCl₄)-induced liver fibrosis were administered Yigankang Decoction and its separated recipe (containing radix salvia militiorrhizae, astragalus and angelica sinensis), respectively, to prepare medicated sera. After medicated rat sera were incubated with subcultured HSCs, the synthesis of collagen was evaluated by 3H-proline incorporation assay, and the expression of TGF-β1 mRNA and protein was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.

RESULTS: All kinds of medicated rat sera prepared in the study could inhibit 3H-proline incorporation at a concentration of 100 or 200 mL/L (normal rat sera at 100 mL/L: 2275.00 ± 114.30 cpm vs 2401.87 ± 108.50 cpm vs 2963.62 ± 128.01 cpm; fibrotic rat sera at 100 mL/L: 2205.31 ± 108.97 cpm vs 2462.70 ± 177.02 cpm vs 3179.12 ± 223.34 cpm; normal rat sera at 200 mL/L: 372.96 ± 123.3 cpm vs 2515.37 ± 98.25 cpm vs 3209.38 ± 110.75 cpm; fibrotic rat sera at 200 mL/L: 2394.29 ± 150.50 cpm vs 2611.25 ± 126.05 cpm vs 3490.46 ± 183.16 cpm; all P < 0.05 or 0.01), and decrease the expression of TGF-β1 mRNA and protein at a concentration of 100 mL/L (all P < 0.01). The sera from rats medicated with Yigankang Decoction had more significant inhibitory effects on 3H-proline incorporation and TGF-β1 expression than those from rats medicated with the separated recipe (all P < 0.01). The sera from medicated fibrotic rats were superior to those from medicated normal rats in the downregulation of TGF-β1 expression (Yigankang Decoction: TGF-β1 mRNA, 0.356 ± 0.032 vs 0.568 ± 0.028; TGF-β1 protein, 0.458 ± 0.009 vs 0.639 ± 0.102; the separated recipe: TGF-β1 mRNA, 0.601 ± 0.047 vs 0.810 ± 0.051; TGF-β1 protein, 0.612 ± 0.126 vs 0.860 ± 0.138; all P <0.05 or P < 0.01).

CONCLUSION: Both Yigankang Decoction and its separated recipe can inhibit collagen synthesis in HSCs perhaps through inhibiton of TGF-β1 expression. Sera from rats medicated with Yigankang Decoction and from fibrotic rats were superior to those from rats medicated with the separated recipe and from normal rats in inhibiting collagen synthesis and decreasing TGF-β1 expression, respectively.

Advances in antifibrotic therapy

Sustained progress in defining the molecular pathophysiology of hepatic fibrosis has led to a comprehensive framework for developing antifibrotic therapies. Indeed, the single greatest limitation in bringing new drugs to the clinical setting is a lack of clarity regarding clinical trial and treatment end points, not a lack of promising agents. A range of treatments, including those developed for other indications, as well as those specifically developed for hepatic fibrosis, are nearing or in clinical trials. Most are focused on attacking features of either hepatic injury and/or activated stellate cells and myofibroblasts, which are the primary sources of extracellular matrix (scar) proteins. Thus, features of injury and stellate cell activation provide a useful template for classifying these emerging agents and point to a new class of therapies for patients with fibrosing liver disease.

Current and future anti-fibrotic therapies for chronic liver disease

Chronic injury results in a wound healing response that eventually leads to fibrosis. The response is generalized, with features common among multiple organ systems. In the liver, various different types of injury lead to fibrogenesis, implying a common pathogenesis. Although several specific therapies for patients who have different liver diseases have been successfully developed, including antiviral therapies for those who have hepatitis B and hepatitis C virus infection, specific and effective antifibrotic therapy remains elusive. Over the past 2 decades, great advances in the understanding of fibrosis have been made and multiple mechanisms underlying hepatic fibrogenesis uncovered. Elucidation of these mechanisms has been of fundamental importance in highlighting novel potential therapies. Preclinical studies have indicated several putative therapies that might abrogate fibrogenesis. This article emphasizes mechanisms underlying fibrogenesis and reviews available and future therapeutics.

Nuclear cathepsin F regulates activation markers in rat hepatic stellate cells

Activation of hepatic stellate cells during liver fibrosis is a major event facilitating an increase in extracellular matrix deposition. The up-regulation of smooth muscle alpha-actin and collagen type I is indicative of the activation process. The involvement of cysteine cathepsins, a class of lysosomal cysteine proteases, has not been studied in conjunction with the activation process of hepatic stellate cells. Here we report a nuclear cysteine protease activity partially attributed to cathepsin F, which co-localizes with nuclear speckles. This activity can be regulated by treatment with retinol/palmitic acid, known to reduce the hepatic stellate cell activation. The treatment for 48 h leads to a decrease in activity, which is coupled to an increase in cystatin B and C transcripts. Cystatin B knockdown experiments during the same treatment confirm the regulation of the nuclear activity by cystatin B. We demonstrate further that the inhibition of the nuclear activity by E-64d, a cysteine protease inhibitor, results in a differential regulation of smooth muscle alpha-actin and collagen type I transcripts. On the other hand, cathepsin F small interfering RNA transfection leads to a decrease in nuclear activity and a transcriptional down-regulation of both activation markers. These findings indicate a possible link between nuclear cathepsin F activity and the transcriptional regulation of hepatic stellate cell activation markers.

Connective tissue growth factor: a fibrogenic master switch in fibrotic liver diseases

Connective tissue growth factor (CTGF=CCN2), one of six members of cysteine-rich, secreted, heparin-binding proteins with a modular structure, is recognized as an important player in fibrogenic pathways as deduced from findings in non-hepatic tissues and emerging results from liver fibrosis. Collectively, the data show strongly increased expression in fibrosing tissues and transforming growth factor (TGF-beta)-stimulated expression in hepatocytes, biliary epithelial cells and stellate cells. Functional activity as a mediator of fibre-fibre, fibre-matrix and matrix-matrix interactions, as an enhancer of profibrogenic TGF-beta and several secondary effects owing to TGF-beta enhancement, and as a down-modulator of the bioactivity of bone morphogenetic protein-7 has been proposed. By changing the activity ratio of TGF-beta to its antagonist bone-morphogenetic protein-7, CTGF is proposed as a fibrogenic master switch for epithelial-mesenchymal transition. Consequently, knockdown of CTGF considerably attenuates experimental liver fibrosis. The spill-over of CTGF from the liver into the blood stream proposes this protein as a non-invasive reporter of TGF-beta bioactivity in this organ. Indeed, CTGF-levels in sera correlate significantly with fibrogenic activity. The data suggest CTGF as a multifaceted regulatory protein in fibrosis, which offers important translational aspects for diagnosis and follow-up of hepatic fibrogenesis and as a target for therapeutic interventions. In addition, CTGF-promoter polymorphism might be of importance as a prognostic genetic marker to predict the progression of fibrosis.

Hepatic fibrosis -- overview

The study of hepatic fibrosis, or scarring in response to chronic liver injury, has witnessed tremendous progress in the past two decades. Clarification of the cellular sources of scar, and emergence of hepatic stellate cells not only as a fibrogenic cell type, but also as a critical immunomodulatory and homeostatic regulator are among the most salient advances. Activation of hepatic stellate cells remains a central event in fibrosis, complemented by evidence of additional sources of matrix-producing cells including bone marrow, portal fibroblasts, and epithelial-mesenchymal transition from both hepatocytes and cholangiocytes. A growing range of cytokines and their receptors and inflammatory cell subsets have further expanded our knowledge about this dynamic process. Collectively, these findings have laid the foundation for continued elucidation of underlying mechanisms, and more importantly for the implementation of rationally based approaches to limit fibrosis, accelerate repair and enhance liver regeneration in patients with chronic liver disease.

Changing the pathogenetic roadmap of liver fibrosis? Where did it start; where will it go?

The pathophysiology of liver injury has attracted the interest of experimentalists and clinicians over many centuries. With the discovery of liver-specific pericytes - formerly called fat-storing cells, Ito-cells, lipocytes, and currently designated as hepatic stellate cells (HSC) - the insight into the cellular and molecular pathobiology of liver fibrosis has evolved and the pivotal role of HSC as a precursor cell-type for extracellular matrix-producing myofibroblasts has been established. Although activation and transdifferentiation of HSC to myofibroblasts is still regarded as the pathogenetic key mechanism of fibrogenesis, recent studies point to a prominent heterogeneity of the origin of myofibroblasts. Currently, the generation of matrix-synthesizing fibroblasts by epithelial-mesenchymal transition, by influx of bone marrow-derived fibrocytes into damaged liver tissue, and by differentiation of circulating monocytes to fibroblasts after homing in the injured liver are discussed as important complementary mechanisms to enlarge the pool of (myo-)fibroblasts in the fibrosing liver. Among the molecular mediators, transforming growth factor-beta (TGF-beta) plays a central role, which is controlled by the bone-morphogenetic protein (BMP)-7, an important antagonist of TGF-beta action. The newly discovered pathways supplement the linear concept of HSC activation to myofibroblasts, point to fibrosis as a systemic response involving extrahepatic organs and reactions, add further evidence to a more or less uniform concept of organ fibrosis in general (e.g. liver, lung, kidney), and offer innovative approaches for the development of non-invasive biomarkers and antifibrotic trials.