Fibrogenesis in pediatric cholestatic liver disease: role of taurocholate and hepatocyte-derived monocyte chemotaxis protein-1 in hepatic stellate cell recruitment

SLC10A5 deficiency causes hypercholanemia

BACKGROUND AND AIMS

Solute Carrier Family 10 Member 5 (SLC10A5) is a member of SLC10, comprising transporters of bile acids, steroidal hormones, and other substrates, but its function remains unclear. The aim of the current investigation was to clarify its function in the metabolism of bile acid and hypercholanemia.

APPROACH AND RESULTS

Whole-exome sequencing and Sanger sequencing were used to identify and confirm the variant in the subjects of hypercholanemia. CRISPR/Cas9-mediated genome engineering was used to establish the knockout and point mutation mice. Primary mouse hepatocytes were isolated, and cell lines were cultured. SLC10A5 was silenced by siRNA and overexpressed by wild-type and mutant plasmids. The fluorescent bile acid derivative was used for the bile acid uptake assay. Bile acids were assessed with ultra-performance liquid chromatography tandem mass spectrometry. A heterozygous variant SLC10A5 : c.994_995del (p.D332X) was identified in subjects with elevated total bile acid or altered bile acid profiles. Bile acids were increased in the serum and liver of knockout and point mutation mice. The expressions of FXR and SHP, regulators involved in the negative feedback of bile acid synthesis, were downregulated, while the bile acid synthesis genes CYP7A1 and CYP8B1 were upregulated in both gene-edited mice. Both the wild and mutant SLC10A5 proteins were localized on the plasma membrane. Knockdown, knockout, or targeted mutation of SLC10A5 led to the inhibition of bile acid uptake by cell lines and primary mouse hepatocytes.

CONCLUSION

SLC10A5 is involved in the uptake of bile acid, and its deficiency causes hypercholanemia.

Cystic fibrosis liver disease in the new era of cystic fibrosis transmembrane conductance regulator (CFTR) modulators

Cystic fibrosis liver disease (CFLD) is characterised by a wide heterogenity of manifestations and severity. It represents a major cause of morbidity in people with cystic fibrosis (PwCF), which will be of increasing relevance as survival increases in the new era of cystic fibrosis care. No medical therapy currently available has evidence to treat or prevent progression of liver disease. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators may be transformative on pulmonary, nutritional and quality of life, but direct effect on long term liver disease outcomes is not yet established. Drug-associated hepatic adverse effects may be common, and clinician familiarity with drug-monitoring recommendations is essential. Longitudinal studies are required to understand the effect of CFTR modulators on the incidence and natural history of CFLD, including with early treatment initiation, in established advanced liver disease, and post liver transplantation.

Er-Chen Decoction Alleviates High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Rats through Remodeling Gut Microbiota and Regulating the Serum Metabolism

Many studies have found that the dysfunction in gut microbiota and the metabolic dysfunction can promote nonalcoholic fatty liver disease (NAFLD) development. Er-Chen decoction (EC) can be used in the treatment of NAFLD. However, the mechanism of this hepatoprotection is still unknown. In this study, we constructed a rat model with NAFLD fed with high-fat chow and administered EC treatment. The therapeutic effects of EC on NAFLD were evaluated by measuring transaminases, blood lipid levels, and pathological changes in the liver. In addition, we measured the effects of EC on liver inflammatory response and oxidative stress. The changes in gut microbiota after EC treatment were studied using 16S rRNA sequencing. Serum untargeted metabolomics analysis was also used to study the metabolic regulatory mechanisms of EC on NAFLD. The results showed that EC decreased the serum transaminases and lipid levels and improved the pathological changes in NAFLD rats. Furthermore, EC enhanced the activities of SOD and GSH-Px and decreased MDA level in the liver. EC treatment also decreased the gene and protein levels of IL-6, IL-1β, and TNF-α in the liver and serum. The 16S rRNA sequencing and untargeted metabolomics indicated that EC treatment affected the gut microbiota and regulated serum metabolism. Correlation analysis showed that the effects of EC on taurine and hypotaurine metabolism, cysteine and methionine metabolism, and vitamin B6 metabolism pathways were associated with affecting in the abundance of Lactobacillus, Dubosiella, Lachnospiraceae, Desulfovibri, Romboutsia, Akkermansia, Intestinimonas, and Candidatus_saccharimonas in the gut. In conclusion, our study confirmed the protective effect of EC on NAFLD. EC could treat NAFLD by inhibiting oxidative stress, reducing inflammatory responses, and improving the dysbiosis of gut microbiota and the modulation of the taurine and hypotaurine metabolism, cysteine and methionine metabolism, and vitamin B6 metabolism pathways in serum.

Disordered farnesoid X receptor signaling is associated with liver carcinogenesis in Abcb11-deficient mice

ABCB11 encodes the bile salt export pump (BSEP), a key regulator in maintaining bile acid (BA) homeostasis. Although inherited ABCB11 mutations have previously been linked to primary liver cancer, whether ABCB11 deficiency leads to liver cancer remains unknown. Here, we analyzed ABCB11 mRNA expression levels in liver tumor specimens [29 with hepatocellular carcinoma (HCC), one with intrahepatic cholangiocarcinoma (ICC), and one with mixed HCC/ICC] with adjacent normal specimens and published human datasets. Liver tissues obtained from Abcb11-deficient (Abcb11^-/- ) mice and wild-type mice at different ages were compared by histologic, RNA-sequencing, and BA analyses. ABCB11 was significantly downregulated in human liver tumors compared with normal controls. Abcb11^-/- mice demonstrated progressive intrahepatic cholestasis and liver fibrosis, and spontaneously developed HCC and ICC over 12 months of age. Abcb11 deficiency increased BAs in the liver and serum in mice, most of which are farnesoid X receptor (FXR) antagonists/non-agonists. Accordingly, the hepatic expression and transcriptional activity of FXR were downregulated in Abcb11^-/- mouse livers. Administration of the FXR agonist obeticholic acid reduced liver injury and tumor incidence in Abcb11^-/- mice. In conclusion, ABCB11 is aberrantly downregulated and plays a vital role in liver carcinogenesis. The cholestatic liver injury and liver tumors developed in Abcb11^-/- mice are associated with increased FXR antagonist BAs and thereby decreased activation of FXR. FXR activation might be a therapeutic strategy in ABCB11 deficiency diseases. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Geniposide suppresses liver injury in a mouse model of DDC-induced sclerosing cholangitis

Sclerosing cholangitis, characterized by biliary inflammation, fibrosis, and stricturing, remains one of the most challenging conditions of clinical hepatology. Geniposide (GE) has anti-inflammatory, hepatoprotective, and cholagogic effects. Whether GE provides inhibition on the development of sclerosing cholangitis is unknown. Here, we investigated the role of GE in a mouse model in which mice were fed with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) for 4 weeks to induce sclerosing cholangitis. The results demonstrated that the increased hepatic gene expressions of pro-inflammatory (IL-6, VCAM-1, MCP-1, and F4/80) and profibrogenic markers (Col1α1, Col1α2, TGF-β, and α-SMA) in DDC feeding mice were reversed after treatment with GE. GE also suppressed expressions of CK19 and Ki67 in DDC-fed mice, suggesting that GE could ameliorate DDC-induced hepatocytes and cholangiocytes proliferation. In addition, GE significantly increased bile acids (BAs) secretion in bile, which correlated with induced expressions of hepatic FXR, BAs secretion transporters (BSEP, MRP2, MDR1, and MDR2), and reduced CYP7A1 mRNA expression. Furthermore, higher expressions of ileal FXR-FGF15 signaling and reduced ASBT were also observed after GE treatment. Taken together, these data showed that GE could modulate inflammation, fibrosis, and BAs homeostasis in DDC-fed mice, which lead to efficiently delay the progression of sclerosing cholangitis.

HJC0416 Attenuates Fibrogenesis in Activated Hepatic Stellate Cells via STAT3 and NF-κB Pathways

BACKGROUND

Hepatic fibrosis is wound-healing response that is the result of hepatic stellate cell (HSC) activation and subsequent excess extracellular matrix deposition. HSCs can be activated by a variety of inflammatory stimuli as well as through the signal transducer and activator of transcription 3 (STAT3) pathway. HJC0416 is a novel, orally bioavailable small-molecule inhibitor of STAT3 that was developed by our team using a fragment-based drug design approach. Previously, our team has shown that HJC0416 has antifibrogenic effects in activated HSCs. Recently, increasing evidence suggests that nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) plays an important role in the activation of HSCs. In the present study, we examined the role of NF-κB inhibition of HSC activation by HJC0416.

METHODS

LX-2 (human) and HSC-T6 (rat) cell lines were used. Expression levels of extracellular proteins, NF-κB and STAT3 expression and DNA binding, and inflammatory cytokine levels were determined using western blot, ELISA, and immunofluorescence assay.

RESULTS

HJC0416 decreased cell viability in a dose-dependent manner in both cell lines and arrested the cell cycle at the S phase. Increased apoptosis was seen in LX-2 cells through Yo-Pro-1 and propidium iodide immunofluorescent stating. HJC0416 significantly decreased expression of fibronectin and collagen I as well as markedly decreased α-SMA and laminin. HJC0416 inhibited the STAT3 pathway by decreasing phosphorylation of STAT3, as well as signal transduction pathway activation. Notably, HJC0416 also inhibited the classic and alternative pathways of NF-κB activation. HJC0416 inhibited LPS-induced p65 nuclear translocation and DNA binding, as well as prevented phosphorylation and degradation of inhibitory protein IκBα. HJC0416 also prevented phosphorylation of serine residue 536 on p65.

CONCLUSIONS

HJC0416, an inhibitor of STAT3, was found to have antifibrogenic properties in activated hepatic stellate cell lines. In addition, HJC0416 was found to inhibit the NF-κB pathway. Owing to this double effect, HJC0416 demonstrates promise for in vivo experimentation as an antifibrosis treatment.

Identification of global mRNA expression profiles and comprehensive bioinformatic analyses of abnormally expressed genes in cholestatic liver disease

BACKGROUND

Cholestatic liver disease (CLD) is a highly heterogeneous hepatobiliary disease with various causes. The purpose of this research was to explore the gene expression changes throughout the course of CLD revealing potential causative molecular mechanisms and therapeutic targets.

METHODS

We established two animal models of cholestasis: 3,5-diethoxycarbonyl-1,4-dihydrocollidine feeding for 2, 4 and 6 weeks and bile duct ligation for 14 days. Using these two models, we identified differentially expressed genes (DEGs) by RNA-Seq analysis and used the newly-found knowledge of DEGs in comprehensive bioinformatic analyses to investigate key molecular events. Sequencing results were confirmed by experimental verification.

RESULTS

Our study detected overlapping DEGs in the two models, of these 568 genes were upregulated and 117 genes were downregulated. Gene Ontology analysis demonstrated that the upregulated genes were associated with the biological processes of cell adhesion, cell migration and cell motility, while the metabolic processes of various substances were enriched for the downregulated genes. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the upregulated pathways were mainly distributed in focal adhesion, ECM-receptor interaction and amoebiasis, while downregulated pathways focused on peroxisome proliferator-activated receptor signaling pathway, metabolic pathways and primary bile acid biosynthesis. These findings were further confirmed by protein-protein interaction network modeling. Hub genes Src, Pdgfb, Col15a1, Mmp9, Egfr were selected using centralities analyses and verified by qRT-PCR.

CONCLUSION

We profiled a global mRNA landscape in CLD to promote a complete understanding of transcriptomic events of this disease, offering candidate biomarkers and therapeutic targets for the clinic.

Modifier genes in cystic fibrosis-related liver disease

PURPOSE OF REVIEW

Cystic fibrosis (CF; OMIM 219700) is caused by variations in the cystic fibrosis transmembrane conductance regulator gene. CF-related liver disease (CFLD) affects approximately one-third of patients with CF, but the severity of CFLD is highly variable. This review provides the latest knowledge in the pathophysiology and CF genetic modifier research in CFLD.

RECENT FINDINGS

So far, the only modifier gene validated in CFLD is SERPINA1 (α-1-antitrypsin) Z allele. Recent studies support the view that cholangiopathy arising in CF is the result of an ill-adapted innate immune response to endotoxins coming from the intestine and triggering a pro-inflammatory response.

SUMMARY

The pathophysiology of liver disease remains uncertain and so far, no therapy has proven effective to prevent the progression of CFLD. A better understanding of the pathophysiology and the effect of environmental and non-cystic fibrosis transmembrane conductance regulator genetic influences in the context of CFLD development would help improve management and develop new drug therapies.

MicroRNA Sequencing Identifies a Serum MicroRNA Panel, Which Combined With Aspartate Aminotransferase to Platelet Ratio Index Can Detect and Monitor Liver Disease in Pediatric Cystic Fibrosis

Cystic fibrosis (CF)-associated liver disease (CFLD) is a hepatobiliary complication of CF. Current diagnostic modalities rely on nonspecific assessments, whereas liver biopsy is the gold standard to assess severity of fibrosis. MicroRNAs (miRNAs) regulate liver disease pathogenesis and are proposed as diagnostic biomarkers. We investigated the combined use of serum miRNAs and aspartate aminotransferase (AST) to platelet ratio (APRI) to diagnose and assess CFLD severity. This was a cross-sectional cohort study of the circulatory miRNA signature of 124 children grouped by clinical, biochemical, and imaging assessments as follows: CFLD (n = 44), CF patients with no evidence of liver disease (CFnoLD; n = 40), and healthy controls (n = 40). Serum miRNAs were analyzed using miRNA sequencing (miRNA-Seq). Selected differentially expressed serum miRNA candidates were further validated by qRT-PCR and statistical analysis performed to evaluate utility to predict CFLD and fibrosis severity validated by liver biopsy, alone or in combination with APRI. Serum miR-122-5p, miR-365a-3p, and miR-34a-5p levels were elevated in CFLD compared to CFnoLD, whereas miR-142-3p and let-7g-5p were down-regulated in CFLD compared to CFnoLD. Logistic regression analysis combining miR-365a-3p, miR-142-3p, and let-7g-5p with APRI showed 21 times greater odds of accurately predicting liver disease in CF with an area under the receiver operating characteristics curve (AUROC) = 0.91 (sensitivity = 83%, specificity = 92%; P < 0.0001). Expression levels of serum miR-18a-5p were correlated with increasing hepatic fibrosis (HF) stage in CFLD (r_s  = 0.56; P < 0.0001), showing good diagnostic accuracy for distinguishing severe (F3-F4) from mild/moderate fibrosis (F0-F2). A unit increase of miR-18a-5p showed a 7-fold increased odds of having severe fibrosis with an AUROC = 0.82 (sensitivity = 93%, specificity = 73%; P = 0.004), indicating its potential to predict fibrosis severity. Conclusion: We identified a distinct circulatory miRNA profile in pediatric CFLD with potential to accurately discriminate liver disease and fibrosis severity in children with CF.

Diagnosis of cirrhosis in patients with chronic hepatitis C genotype 4: Role of ABCB11 genotype polymorphism and plasma bile acid levels

BACKGROUND/AIMS

Chronic hepatitis C (CHC)-related mortality generally results from cirrhosis and subsequent complications. We aimed to investigate the potential role of plasma bile acid levels and ABCB11 1331T > C (V444A, rs2287622) (ATP-binding cassette subfamily B, member 11) gene polymorphism in fibrosis prediction in CHC genotype 4 patients.

MATERIALS AND METHODS

This case control study included 85 healthy control and the following 225 subjects: 170 adult patients infected with hepatitis C virus (HCV) and categorized into three groups according to liver biopsy; no fibrosis group (F0) (n=33), early fibrosis group (F1-F2) (n=61), and advanced fibrosis group (F3-F4) (n=76). Fasting bile acid levels, hepatitis C virus (HCV) genotyping, and ABCB11 1331T > C gene polymorphism were assessed.

RESULTS

The frequency of the variant homozygote genotype CC in advanced fibrosis was significantly higher than that in early fibrosis (48.7% vs. 36.1%) (odd ratio, OR =2.58; 95% confidence interval, CI=1.07-6.20; p=0.03). C allele was significantly represented in advanced fibrosis (65.8%) compared with that in early fibrosis (51.6%) (OR=1.80, 95% CI=1.10-2.93, p=0.01). A significant elevation of plasma bile acid levels in advanced fibrosis was observed compared with those in early fibrosis (p≤0.001). Receiver operating characteristic curve for plasma bile acid levels at cutoff value of 75.5 μmol/L had a 59% specificity and 97.4% sensitivity as a predictor of advanced hepatic fibrosis (AUROC=0.78%).

CONCLUSION

We concluded that Egyptian patients having chronic hepatitis C genotype 4 with CC genotype of ABCB11 SNP 1331T > C and high plasma bile acid levels at cutoff value of 75.5 μmol/L were associated with advanced hepatic fibrosis.

Inflammation and the Gut-Liver Axis in the Pathophysiology of Cholangiopathies

Cholangiocytes, the epithelial cells lining the bile ducts, represent the unique target of a group of progressive diseases known as cholangiopathies whose pathogenesis remain largely unknown. In normal conditions, cholangiocytes are quiescent and participate to the final bile volume and composition. Following exogenous or endogenous stimuli, cholangiocytes undergo extensive modifications of their phenotype. Reactive cholangiocytes actively proliferate and release a set of proinflammatory molecules, which act in autocrine/paracrine manner mediating the cross-talk with other liver cell types and innate and adaptive immune cells. Cholangiocytes themselves activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Gut microbiota has been implicated in the development and progression of the two most common cholangiopathies, i.e., primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), which have distinctive microbiota composition compared to healthy individuals. The impairment of intestinal barrier functions or gut dysbiosis expose cholangiocytes to an increasing amount of microorganisms and may exacerbate inflammatory responses thus leading to fibrotic remodeling of the organ. The present review focuses on the complex interactions between the activation of innate immune responses in reactive cholangiocytes, dysbiosis, and gut permeability to bacterial products in the pathogenesis of PSC and PBC.

HMBOX1 in hepatocytes attenuates LPS/D-GalN-induced liver injury by inhibiting macrophage infiltration and activation

The HMBOX1 (Homeobox Containing 1) gene was first isolated from the human pancreatic cDNA libraries and is widely expressed in many tissues. Previously, we detected high expression of HMBOX1 in the liver, but its function was unclear. In this study, hepatocyte-specific HMBOX1 knockout mice (Hm^△hep mice) were generated and used to characterize the function of HMBOX1 in the LPS/D-GalN-induced acute liver failure model. HMBOX1-knockout exhibits exacerbated liver injury induced by LPS/D-GalN, accompanied with high levels of inflammatory cytokines both in the liver and in circulation. Further investigation demonstrated that HMBOX1 negatively regulates NF-κB signal transduction. Therefore, HMBOX1-knockout in hepatocytes promotes CCL2 expression through the activation of NF-κB signaling, which enhanced the infiltration of macrophages into the liver. In addition, the decrease of HMBOX1 in hepatocytes promotes the activation of macrophages, upregulating CD80 and MHCⅡ, as well as inflammatory factors TNF-α and IL-6. Importantly, overexpression of HMBOX1 rescued liver injury in Hm^△hep mice. These findings indicate that HMBOX1 in hepatocytes acts as a key immunosuppressive factor for inflammation and plays a critical protective role in LPS/D-GalN-induced liver injury.

Antifibrosis Effect of Novel Oridonin Analog CYD0618 Via Suppression of the NF-κB Pathway

BACKGROUND

Liver fibrosis is characterized as excessive deposition of the extracellular matrix proteins, primarily by activated hepatic stellate cells (HSCs). NF-κB has been reported as one of the major mediators of HSC activation. Previously, our team reported that oridonin exhibited antihepatic fibrogenetic activity in vitro. In this study, we examined the effects of its novel derivative CYD0618 on HSC viability, apoptosis, and NF-κB signaling.

METHODS

Cell proliferation of activated human and rat HSC lines LX-2 and HSC-T6 was measured using Alamar Blue Assay. Apoptosis was measured by a Cell Death Detection ELISA kit. Cellular proteins were determined by Western blots and immunofluorescence.

RESULTS

CYD0618 significantly inhibited LX-2 and HSC-T6 cell proliferation in a dose-dependent manner. CYD0618 induced cell apoptosis in both cell lines. CYD0618 treatment increased cell cycle inhibitory protein p21, p27, and induced apoptosis marker cleaved poly (ADP-ribose) polymerase, while suppressing the expression of Collagen type 1. CYD0618 blocked lipopolysaccharide (LPS)-induced NF-κB p65 nuclear translocation and DNA binding activity and prevented LPS-induced NF-κB inhibitory protein IκBα phosphorylation and degradation. LPS-stimulated NF-κB downstream target cytokines IL-6 and MCP-1 were attenuated by CYD0618. Endogenous and LPS-stimulated NF-κB p65 S⁵³⁶ phosphorylation was inhibited by CYD0618 treatment.

CONCLUSIONS

The potent antihepatic fibrogenetic effect of CYD0618 may be mediated via suppression of the NF-κB pathway.

Taurocholic acid is an active promoting factor, not just a biomarker of progression of liver cirrhosis: evidence from a human metabolomic study and in vitro experiments

BACKGROUND

Previous studies have indicated that bile acid is associated with progression of liver cirrhosis. However, the particular role of specific bile acid in the development of liver cirrhosis is not definite. The present study aims to identify the specific bile acid and explore its possible mechanisms in promoting liver cirrhosis.

METHODS

Thirty two cirrhotic patients and 27 healthy volunteers were enrolled. Age, gender, Child-Pugh classification and serum of patients and volunteers were collected. Liquid chromatography tandem mass spectrometry (LC-MS) was utilized to determine concentrations of 12 bile acids in serum. Principal component analysis, fold change analysis and heatmap analysis were used to identify the most changed bile acid. And pathway analysis was used to identify the most affected pathway in bile acid metabolism. Spearman rank correlation analysis was employed to assess correlation between concentrations of bile acids and Child-Pugh classification. Hepatic stellate cells (LX-2) were cultured in DMEM. LX-2 cells were also co-cultured with HepG2 cells in the transwell chambers. LX-2 cells were treated with Na+/taurocholate in different concentrations. Western blot was used to evaluate the expression of alpha smooth muscle actin (α-SMA), type I collagen, and Toll-like receptor 4 (TLR4) in LX-2 cells.

RESULTS

Concentrations of 12 bile acids in serum of patients and healthy volunteers were determined with LC-MS successively. Principal component analysis, fold change analysis and heatmap analysis identified taurocholic acid (TCA) to be the most changed bile acid. Pathway analysis showed that TCA biosynthesis increased significantly. Spearman rank correlation analysis showed that concentration of TCA in serum of cirrhotic patients was positively associated with Child-Pugh classification. TCA increased the expression of α-SMA, type I collagen, and TLR4 in LX-2 cells. Moreover, the above effect was strengthened when LX-2 cells were co-cultured with HepG2 cells.

CONCLUSIONS

Increased TCA concentration in serum of liver cirrhotic patients is mainly due to increased bile acid biosynthesis. TCA is an active promoter of the progression of liver cirrhosis. TCA promoting liver cirrhosis is likely through activating hepatic stellate cells via upregulating TLR4 expression. TCA is a potential therapeutic target for the prevention and treatment of liver cirrhosis.

Luteolin-Mediated Inhibition of Hepatic Stellate Cell Activation via Suppression of the STAT3 Pathway

Hepatic stellate cell (HSC) activation is responsible for hepatic fibrogenesis and is associated with an overexpression of transcription 3 (STAT3). Luteolin, a common dietary flavonoid with potent anti-inflammatory properties, has previously demonstrated antifibrogenic properties in HSCs but the mechanism has not been fully elucidated. Activated human and rat hepatic stellate cell lines LX-2 and HSC-T6 were used to study the effects of luteolin on HSCs. Cellular proteins were determined by western blot and immunofluorescence. Cell proliferation was assessed with Alamar Blue assay. Luteolin significantly decreased LX-2 and HSC-T6 cell viability in a time-and-dose-dependent manner, as well as decreased HSC end-products α-smooth muscle actin (α-SMA), collagen I, and fibronectin. Luteolin decreased levels of total and phosphorylated STAT3, suppressed STAT3 nuclear translocation and transcriptional activity, and attenuated expression of STAT3-regulated proteins c-myc and cyclin D1. STAT3 specific inhibitors stattic and SH-4-54 demonstrated similar effects on HSC viability and α-SMA production. In LX-2 and HSC-T6 cells, luteolin demonstrates a potent ability to inhibit hepatic fibrogenesis via suppression of the STAT3 pathway. These results further elucidate the mechanism of luteolin as well as the effect of the STAT3 pathway on HSC activation.

Anti-inflammatory properties of ursodeoxycholyl lysophosphatidylethanolamide in endotoxin-mediated inflammatory liver injury

AIM

Endotoxin-mediated liver inflammation is a key component of many acute and chronic liver diseases contributing to liver damage, fibrosis and eventually organ failure. Here, we investigated ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE), a synthetic bile acid-phospholipid conjugate regarding its anti-inflammatory and anti-fibrogenic properties.

METHODS

Anti-inflammatory properties of UDCA-LPE were evaluated in a mouse model of D-galactosamine/lipopolysaccharide (GalN/LPS)-induced acute liver injury, LPS treated RAW264.7 macrophages and murine primary Kupffer cells. Furthermore, anti-inflammatory and anti-fibrotic effects of UDCA-LPE were studied on primary hepatic stellate cells (HSC) incubated with supernatant from LPS±UDCA-LPE treated RAW264.7 cells.

RESULTS

UDCA-LPE ameliorated LPS-induced increase of IL-6, TNF-α, TGF-β, NOX-2 in the GalN/LPS model by up to 80.2% for IL-6. Similarly, UDCA-LPE markedly decreased the expression of inflammatory cytokines IL-6, TNF-α and TGF-β as well as the chemokines MCP1 and RANTES in LPS-stimulated RAW 264.7 cells. Anti-inflammatory effects were also observed in primary murine Kupffer cells. Mechanistic evaluation revealed a reversion of LPS-activated pro-inflammatory TLR4 pathway by UDCA-LPE. Moreover, UDCA-LPE inhibited iNOS and NOX-2 expression while activating eNOS via phosphorylation of AKT and pERK1/2 in RAW264.7 cells. HSC treated with conditioned medium from LPS±UDCA-LPE RAW264.7 cells showed lower fibrogenic activation due to less SMAD2/3 phosphorylation, reduced expression of profibrogenic CTGF and reduced pro-inflammatory chemokine expression.

CONCLUSION

In the setting of endotoxin-mediated liver inflammation, UDCA-LPE exerts profound anti-inflammatory and anti-fibrotic effect implying a promising potential for the drug candidate as an experimental approach for the treatment of acute and chronic liver diseases.

Schistosome-Induced Fibrotic Disease: The Role of Hepatic Stellate Cells

Hepatic fibrosis is a common pathology in various liver diseases. Hepatic stellate cells (HSCs) are the main cell type responsible for collagen deposition and fibrosis formation in the liver. Schistosomiasis is characterised by granulomatous fibrosis around parasite eggs trapped within the liver and other host tissues. This response is facilitated by the recruitment of immune cells and the activation of HSCs. The interactions between HSCs and schistosome eggs are complex and diverse, and a better understanding of these interactions could lead to improved resolution of fibrotic liver disease, including that associated with schistosomiasis. Here, we discuss recent advances in HSC biology and the role of HSCs in hepatic schistosomiasis.

Lung and liver growth and retinoic acid status in human fetuses with congenital diaphragmatic hernia

BACKGROUND

Abnormal retinoic acid (RA) signalling is considered a major cause of congenital diaphragmatic hernia (CDH). Pulmonary hypoplasia and pulmonary hypertension are the major causes of morbidity and mortality in infants born with CDH. Experimental studies in animals have found that RA signalling is involved in lung and liver development, but animal models of CDH do not directly correlate with CDH in human fetuses. This study investigated if RA status is also linked to lung and liver growth in human fetuses with CDH.

STUDY DESIGN AND PATIENTS

Hepatic stellate cells (HSC) in autopsy human fetal liver tissue were identified using cRBP-1 immunohistochemistry and the numbers of HSC manually counted. In mammals, RA is principally stored in HSC complexed to cRBP-1 and therefore cRBP-1⁺ HSC numbers were used as an indicator of fetal RA status. The number of HSCs was correlated with liver and lung weights, calculated relative to either normal biometric values or fetal body weight.

RESULTS

The number of cRBP-1⁺ HSCs correlated with lung weight contralateral to the side of the diaphragmatic hernia (r=0.82, p=0.025) and combined lung weight (r=0.78, p=0.039) but not with ipsilateral lung weight (r=0.43, p=0.33), in fetuses with right and left CDH and a case of giant omphalocoele. Liver growth was influenced by contact with diaphragm but not significantly correlated with cRBP-1 expression (r=0.52, p=0.056).

CONCLUSION

Fetal RA stores, reflected in the number of cRBP-1⁺ HSCs, influence lung growth as well as diaphragm development in human fetuses with CDH. Contact with diaphragm influenced liver growth.

Triplex High-Resolution Melting Assay for the Simultaneous Assessment of IFNL3 rs12979860, ABCB11 rs2287622, and RNF7 rs16851720 Genotypes in Chronic Hepatitis C Patients

Chronic hepatitis C (CHC) is a leading cause of liver disease. Despite the improved efficacy of new antivirals, their high costs preclude their adoption in resource-limited settings, where CHC prevalence is highest. We developed a triplex high-resolution melting assay for the simultaneous assessment of three genetic polymorphisms related to the response to treatment and development of advanced fibrosis in CHC: IFNL3 rs12979860, ABCB11 rs2287622, and RNF7 rs16851720. We validated the assay in clinical samples from 130 CHC patients treated with classic therapy. The assay showed excellent reproducibility and 100% accuracy, sensitivity, and specificity against the gold standard Sanger sequencing. When added to routine examination data, genotype information significantly improved their performance for prediction of advanced liver fibrosis and sustained virological response (P = 0.041 and P = 0.011, respectively). Correspondingly, the full models had area under the receiver operating characteristic curve values of 0.842 (95% CI, 0.773-0.911) and 0.921 (95% CI, 0.870-0.972) and integrated discrimination improvements of 7.5% (95% CI, 2.5%-12.5%; P = 0.003) and 11.5% (95% CI, 5.8%-17.2%; P < 0.001), respectively. This is the first report on a diagnostic test for simultaneous genotyping of IFNL3, ABCB11, and RNF7 in CHC patients. Reliable and inexpensive, the assay should provide useful information for the clinical management of CHC, like identification of patients at risk of rapid disease progression or with high chances of response to classic therapy.

Taurocholate Induces Biliary Differentiation of Liver Progenitor Cells Causing Hepatic Stellate Cell Chemotaxis in the Ductular Reaction: Role in Pediatric Cystic Fibrosis Liver Disease

Cystic fibrosis liver disease (CFLD) in children causes progressive fibrosis leading to biliary cirrhosis; however, its cause(s) and early pathogenesis are unclear. We hypothesized that a bile acid-induced ductular reaction (DR) drives fibrogenesis. The DR was evaluated by cytokeratin-7 immunohistochemistry in liver biopsies, staged for fibrosis, from 60 children with CFLD, and it demonstrated that the DR was significantly correlated with hepatic fibrosis stage and biliary taurocholate levels. To examine the mechanisms involved in DR induction, liver progenitor cells (LPCs) were treated with taurocholate, and key events in DR evolution were assessed: LPC proliferation, LPC biliary differentiation, and hepatic stellate cell (HSC) chemotaxis. Taurocholate induced a time-dependent increase in LPC proliferation and expression of genes associated with cholangiocyte differentiation (cytokeratin 19, connexin 43, integrin β4, and γ-glutamyltranspeptidase), whereas the hepatocyte specification marker HNF4α was suppressed. Functional cholangiocyte differentiation was demonstrated via increased acetylated α-tubulin and SOX9 proteins, the number of primary cilia⁺ LPCs, and increased active γ-glutamyltranspeptidase enzyme secretion. Taurocholate induced LPCs to release MCP-1, MIP1α, and RANTES into conditioned medium causing HSC chemotaxis, which was inhibited by anti-MIP1α. Immunofluorescence confirmed chemokine expression localized to CK7⁺ DR and LPCs in CFLD liver biopsies. This study suggests that taurocholate is involved in initiating functional LPC biliary differentiation and the development of the DR, with subsequent induction of chemokines that drive HSC recruitment in CFLD.

Ultrastructural Characteristics of Rat Hepatic Oval Cells and Their Intercellular Contacts in the Model of Biliary Fibrosis: New Insights into Experimental Liver Fibrogenesis

PURPOSE

Recently, it has been emphasized that hepatic progenitor/oval cells (HPCs) are significantly involved in liver fibrogenesis. We evaluated the multipotential population of HPCs by transmission electron microscope (TEM), including relations with adherent hepatic nonparenchymal cells (NPCs) in rats with biliary fibrosis induced by bile duct ligation (BDL).

METHODS

The study used 6-week-old Wistar Crl: WI(Han) rats after BDL for 1, 6, and 8 weeks.

RESULTS

Current ultrastructural analysis showed considerable proliferation of HPCs in experimental intensive biliary fibrosis. HPCs formed proliferating bile ductules and were scattered in periportal connective tissue. We distinguished 4 main types of HPCs: 0, I, II (bile duct-like cells; most common), and III (hepatocyte-like cells). We observed, very seldom presented in literature, cellular interactions between HPCs and adjacent NPCs, especially commonly found transitional hepatic stellate cells (T-HSCs) and Kupffer cells/macrophages. We showed the phenomenon of penetration of the basement membrane of proliferating bile ductules by cytoplasmic processes sent by T-HSCs and the formation of direct cell-cell contact with ductular epithelial cells related to HPCs.

CONCLUSIONS

HPC proliferation induced by BDL evidently promotes portal fibrogenesis. Better understanding of the complex cellular interactions between HPCs and adjacent NPCs, especially T-HSCs, may help develop antifibrotic therapies in the future.

The dendritic cell-T helper 17-macrophage axis controls cholangiocyte injury and disease progression in murine and human biliary atresia

Biliary atresia (BA) is a fibroinflammatory obstruction of the extrahepatic biliary tree in neonates. While intrahepatic bile duct proliferation is universal at diagnosis, bile duct paucity develops later. We hypothesized that polarized T helper lymphocyte responses orchestrate progression of intrahepatic biliary injury in this disease. Interleukin 17A (IL-17A)-green fluorescent protein, cluster of differentiation 11c (CD11c)/diphtheria toxin receptor, and IL-17 receptor A^-/- mice were used to examine T-lymphocyte polarization, inflammatory leukocyte recruitment, and biliary injury in rhesus rotavirus-induced BA. Multiparameter flow cytometry and automated image analysis of immunostaining were applied to liver tissue samples from infants with BA. In the mouse model, activated CD4⁺ lymphocytes started to emerge in the liver on day 8 after viral challenge, while innate immune responses were waning. Plasma IL-17A levels rose concomitantly with hepatic accumulation of T helper 17 lymphocytes and myeloid dendritic cells. Targeted depletion of CD11c⁺ dendritic cells diminished hepatic IL-17A production and ameliorated intrahepatic bile duct injury. Recombinant IL-17A induced expression of chemokine (C-C motif) ligand 2 in neonatal cholangiocytes in vitro, and blockade of the corresponding chemokine (C-C motif) receptor 2 reduced recruitment of inflammatory macrophages to the liver in vivo. Genetic disruption of IL-17A signaling was associated with down-regulation of hepatic Ccl2/Ccr2 messenger RNA expression, reduced infiltration of the liver with inflammatory Ly6C^hi macrophages, and improved survival. In the liver of infants with BA, cholangiocytes were found to express IL-17 receptor A, and the prevalence of IL-17A⁺ cells was positively correlated with the degree of CD68⁺ macrophage infiltration at diagnosis. Hepatic CD4⁺ lymphocytes were chief producers of IL-17A in patients with progressive disease undergoing liver transplantation.

CONCLUSION

These findings identify the dendritic cell-T helper 17-macrophage axis as a target for the development of strategies to block progression of intrahepatic bile duct injury in patients with BA. (Hepatology 2017;65:174-188).

Imaging the Abdominal Manifestations of Cystic Fibrosis

Cystic fibrosis (CF) is a multisystem disease with a range of abdominal manifestations including those involving the liver, pancreas, and kidneys. Recent advances in management of the respiratory complications of the disease has led to a greater life expectancy in patients with CF. Subsequently, there is increasing focus on the impact of abdominal disease on quality of life and survival. Liver cirrhosis is the most important extrapulmonary cause of death in CF, yet significant challenges remain in the diagnosis of CF related liver disease. The capacity to predict those patients at risk of developing cirrhosis remains a significant challenge. We review representative abdominal imaging findings in patients with CF selected from the records of two academic health centres, with a view to increasing familiarity with the abdominal manifestations of the disease. We review their presentation and expected imaging findings, with a focus on the challenges facing diagnosis of the hepatic manifestations of the disease. An increased familiarity with these abdominal manifestations will facilitate timely diagnosis and management, which is paramount to further improving outcomes for patients with cystic fibrosis.

Aggf1 attenuates hepatic inflammation and activation of hepatic stellate cells by repressing Ccl2 transcription

Liver injury represents a continuum of pathophysiological processes involving a complex interplay between hepatocytes, macrophages, and hepatic stellate cells. The mechanism whereby these intercellular interactions contribute to liver injury and fibrosis is not completely understood. We report here that angiogenic factor with G patch and FHA domains 1 (Aggf1) was downregulated in the livers of cirrhotic patients compared to healthy controls and in primary hepatocytes in response to carbon tetrachloride (CCl4) stimulation. Overexpression of Aggf1 attenuated macrophage chemotaxis. Aggf1 interacted with NF-κB to block its binding to theCcl2 gene promoter and repressed Ccl2 transcription in hepatocytes. Macrophages cultured in the conditioned media collected from Aggf1-overexpressing hepatocytes antagonized HSC activation. Taken together, our data illustrate a novel role for Aggf1 in regulating hepatic inflammation and provide insights on the development of interventional strategies against cirrhosis.

Hypoxia-inducible factor-2α promotes hepatocyte apoptosis during cholestasis

AIM

Hypoxia-inducible factor-2α (HIF-2α) has been reported to play an important role in a host of pathophysiological processes, including cellular survival. This study explores the role of HIF-2α in cholestasis-mediated hepatocyte apoptosis.

METHODS

Hypoxia-inducible factor-2α expression was measured by immunohistochemistry and confocal microscopy. Hepatic apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling. The cholestatic mouse model was treated with bile duct ligation. The c-myc, p53, and Bax protein levels were measured with Western blot analysis.

RESULTS

In pediatric and murine cholestatic liver tissues, HIF-2α protein was widely expressed in the nucleus of parenchymal cells as well as in stromal cells. Hepatocyte HIF-2α expression was significantly elevated at the early stage of pediatric cholestasis and decreased at the late stage. In both in vivo and in vitro murine studies, HIF-2α deletion could alleviate cholestasis-mediated hepatocyte apoptosis and regulate the expression of c-myc, p53, and Bax proteins.

CONCLUSION

These findings implied the contribution of HIF-2α to cholestasis-mediated hepatocyte apoptosis.

Relevance of 3D Cholangiography and Transient Elastography to Assess Cystic Fibrosis-Associated Liver Disease?

Background. Cystic fibrosis-associated liver disease (CFLD) is a major cause of death. The objective of our retrospective study was to describe the relevance of magnetic resonance imaging (MRI) and liver stiffness measurement (LSM) for CFLD evaluation. Methods. All cystic fibrosis adult patients evaluated by MRI and LSM were included. MR signs of portal hypertension (PHT), dysmorphia, or cholangitis were collected and LSM expressed in kPa and Metavir. Results. Of 25 patients, 52% had abnormal MRI. Median LSM was 5.7 kPa (3.4–9.9). Three patients had F2 score and one had F3 score. In patients with PHT, LSM was 7.85 kPa (3.7–9.9) compared to 5 (3.4–7.5) in others, p = 0.02. In patients with abnormal liver function tests, 50% had increased LSM (≥F2), whereas 94% with normal tests had normal LSM (p = 0.04). Seven patients had abnormal MRI despite normal ultrasonography. Conclusions. MRI and LSM provide useful information on CFLD and may help to screen patients with PHT.

Mechanism of pancreatic and liver malformations in human fetuses with short-rib polydactyly syndrome

BACKGROUND

The short-rib polydactyly (SRP) syndromes are rare skeletal dysplasias caused by abnormalities in primary cilia, sometimes associated with visceral malformations.

METHODS

The pathogenesis of ductal plate malformation (DPM) varies in different syndromes and has not been investigated in SRP. We have studied liver development in five SRP fetuses and pancreatic development in one SRP fetus, with genetically confirmed mutations in cilia related genes, with and without DPMs, using the immunoperoxidase technique, and compared these to other syndromes with DPM.

RESULTS

Acetylated tubulin expression was abnormal in DPM in SRP, Meckel syndrome, and autosomal recessive polycystic kidney disease (ARPKD), confirming ciliary anomalies. SDF-1 was abnormally expressed in SRP and two of three cases of autosomal dominant polycystic kidney disease (ADPKD) but not ARPKD or Meckel. Increased density of quiescent hepatic stellate cells was seen in SRP, Meckel, one of three cases of ARPKD, and two of three cases of ADPKD with aberrant hepatocyte expression of keratin 19 in SRP and ADPKD. Immunophenotypic abnormalities were present even in fetal liver without fully developed DPMs. The SRP case with DPM and pancreatic malformations showed abnormalities in the pancreatic head (influenced by mesenchyme from the septum transversum, similar to liver) but not pancreatic body (influenced by mesenchyme adjacent to the notochord).

CONCLUSION

In SRP, there are differentiation defects of hepatocytes, cholangiocytes, and liver mesenchyme and, in rare cases, pancreatic mesenchymal anomalies. The morphological changes were subtle in early gestation but immunophenotypic abnormalities were present. Mesenchymal-epithelial interactions may contribute to the malformations. Birth Defects Research (Part A) 106:549-562, 2016. © 2016 Wiley Periodicals, Inc.

The role of liver progenitor cells during liver regeneration, fibrogenesis, and carcinogenesis

The growing worldwide challenge of cirrhosis and hepatocellular carcinoma due to increasing prevalence of excessive alcohol consumption, viral hepatitis, obesity, and the metabolic syndrome has sparked interest in stem cell-like liver progenitor cells (LPCs) as potential candidates for cell therapy and tissue engineering, as an alternative approach to whole organ transplantation. However, LPCs always proliferate in chronic liver diseases with a predisposition to cancer; they have been suggested to play major roles in driving fibrosis, disease progression, and may even represent tumor-initiating cells. Hence, a greater understanding of the factors that govern their activation, communication with other hepatic cell types, and bipotential differentiation as opposed to their potential transformation is needed before their therapeutic potential can be harnessed.

Pharmacological inhibition of apical sodium-dependent bile acid transporter changes bile composition and blocks progression of sclerosing cholangitis in multidrug resistance 2 knockout mice

Deficiency of multidrug resistance 2 (mdr2), a canalicular phospholipid floppase, leads to excretion of low-phospholipid "toxic" bile causing progressive cholestasis. We hypothesize that pharmacological inhibition of the ileal, apical sodium-dependent bile acid transporter (ASBT), blocks progression of sclerosing cholangitis in mdr2(-/-) mice. Thirty-day-old, female mdr2(-/-) mice were fed high-fat chow containing 0.006% SC-435, a minimally absorbed, potent inhibitor of ASBT, providing, on average, 11 mg/kg/day of compound. Bile acids (BAs) and phospholipids were measured by mass spectrometry. Compared with untreated mdr2(-/-) mice, SC-435 treatment for 14 days increased fecal BA excretion by 8-fold, lowered total BA concentration in liver by 65%, reduced total BA and individual hydrophobic BA concentrations in serum by >98%, and decreased plasma alanine aminotransferase, total bilirubin, and serum alkaline phosphatase levels by 86%, 93%, and 55%, respectively. Liver histology of sclerosing cholangitis improved, and extent of fibrosis decreased concomitant with reduction of hepatic profibrogenic gene expression. Biliary BA concentrations significantly decreased and phospholipids remained low and unchanged with treatment. The phosphatidylcholine (PC)/BA ratio in treated mice corrected toward a ratio of 0.28 found in wild-type mice, indicating decreased bile toxicity. Hepatic RNA sequencing studies revealed up-regulation of putative anti-inflammatory and antifibrogenic genes, including Ppara and Igf1, and down-regulation of several proinflammatory genes, including Ccl2 and Lcn2, implicated in leukocyte recruitment. Flow cytometric analysis revealed significant reduction of frequencies of hepatic CD11b(+) F4/80(+) Kupffer cells and CD11b(+) Gr1(+) neutrophils, accompanied by expansion of anti-inflammatory Ly6C(-) monocytes in treated mdr2(-/-) mice.

CONCLUSION

Inhibition of ASBT reduces BA pool size and retention of hydrophobic BA, favorably alters the biliary PC/BA ratio, profoundly changes the hepatic transcriptome, attenuates recruitment of leukocytes, and abrogates progression of murine sclerosing cholangitis.

Hepatocytes in liver injury: Victim, bystander, or accomplice in progressive fibrosis?

Chronic liver disease causes significant morbidity and mortality through progressive fibrosis, cirrhosis, and liver cancer. The classical theory of fibrogenesis has hepatic stellate cells (HSCs) as the principal and only significant source of abnormal extracellular matrix (ECM). Further, HSCs have the major role in abnormal ECM turnover. It is the death of hepatocytes, as the initial target of injury, that initiates a sequence of events including the recruitment of inflammatory cells and activation of HSCs. Following this initial response, the ongoing insult to hepatocytes is regarded as perpetuating injury, but otherwise, hepatocytes are regarded as "victims" and "bystanders" in progressive fibrosis. Recent developments, however, challenge this view and suggest the concept of the hepatocyte being an active participant in liver injury. It is clear now that hepatocytes undergo phenotypic changes, adapt to injury, and react to the altered microenvironment. In this review, we describe studies showing that hepatocytes contribute to progressive fibrosis by direct manipulation of the surrounding ECM and through signaling to effector cells, particularly HSCs and intrahepatic immune cells. Together, these findings suggest an active "accomplice" role for the hepatocyte in progressive liver fibrosis and highlight novel pathways that could be targeted for development of future anti-fibrotic therapies.

Peritumoral Cbl is a strong independent prognostic marker after curative resection of hepatocellular carcinoma

Growing evidences support the concept that peritumoral microenvironment gene expression is an important element for physicians to make an accurate prognosis. Nonetheless, the correlation between peritumoral ubiquitin ligases and the hepatocellular carcinoma (HCC) survival remains unclear till this present. The expression of intratumoral and peritumoral Casitas B-lineage Lymphoma (Cbl) and epidermal growth factor receptor (EGFR) in hepatocellular carcinomas (HCCs) followed by curative resection was assessed by tissue microarray-based immune-histochemistry in two independent cohorts (n = 352). Their respective prognostic values and other clinicopathologic factors were then evaluated. The peritumoral Cbl density, much higher than that in intratumoral tissue, was an independent prognostic factor for overall survival (P < 0.001) and time to recurrence (P < 0.001) of HCCs after curative resection. The hazard ratio were 1.587 and 1.689, respectively. However, there was no correlation between intratumoral Cbl and prognosis. The peritumoral Cbl was also associated with prognosis even in HCC subgroups with small tumor size, negative AFP, without microvascular invasion and negative HBeAg. After a thorough analysis pertaining to the key role of Cbl on ubiquitination and degradation of activated receptor tyrosine kinases, we eventually discovered the negative correlation between peritumoral Cbl and EGFR (P = 0.015). Furthermore, the combination of peritumoral Cbl and EGFR serves as a much stronger indicator to make an accurate prognosis, especially during early recurrence (P < 0.001). These findings suggest that low expression of peritumoral Cbl and EGFR were positively associated with tumor size, microvascular invasion and patients survival after hepatectomy, highlighting the key role of peritumoral liver milieu in HCC progression.

Enhanced anti-fibrogenic effects of novel oridonin derivative CYD0692 in hepatic stellate cells

Oridonin, isolated from Rabdosia rubescens, has been proven to possess various anti-neoplastic and anti-inflammatory properties. Previously, we reported the anti-fibrogenic effects of oridonin for liver in vitro. In the present study, we investigated the effects of a newly designed analog CYD0692 in vitro. Cell viability was measured by Alamar Blue assay. Cell apoptosis was assessed by Cell Death ELISA and Yo-Pro-1 staining. Western blots were performed for cellular proteins. Flow cytometry was used to measure cell cycle regulation. CYD0692 significantly inhibited LX-2 cells proliferation in a dose- and time-dependent manner with an IC50 value of ~0.7 μM for 48 h, ~tenfold greater potency than oridonin. Similar results were observed in HSC-T6 cells. In contrast, on the human hepatocyte cell line C3A, only 12 % of the cell growth was inhibited with 5 μM of CYD0692 treatment for 48 h, while 30 % inhibited at 10 μM. After CYD0692 treatment on LX-2 cells, apoptosis and S-phase cell cycle arrest were induced; cleaved-PARP, p21, and p53 were activated while cyclin-B1 levels declined. In addition, α-smooth muscle actin, type I Collagen, and fibronectin (FN) were markedly down regulated. Transforming growth factor β1 (TGF β1) has been identified as a dominant stimulator for ECM production in HSC. Our results indicated that pretreatment with CYD0692 blocked TGF β1-induced FN expression, thereby decreasing the downstream factors of TGF β1 signaling, such as Phospho-Smad2/3 and phospho-ERK. In comparison with oridonin, its novel derivative CYD0692 has demonstrated to be a more potent and potentially safer anti-fibrogenic agent for the treatment of hepatic fibrosis.

The development of hepatic stellate cells in normal and abnormal human fetuses - an immunohistochemical study

The precise embryological origin and development of hepatic stellate cells is not established. Animal studies and observations on human fetuses suggest that they derive from posterior mesodermal cells that migrate via the septum transversum and developing diaphragm to form submesothelial cells beneath the liver capsule, which give rise to mesenchymal cells including hepatic stellate cells. However, it is unclear if these are similar to hepatic stellate cells in adults or if this is the only source of stellate cells. We have studied hepatic stellate cells by immunohistochemistry, in developing human liver from autopsies of fetuses with and without malformations and growth restriction, using cellular Retinol Binding Protein-1 (cRBP-1), Glial Fibrillary Acidic Protein (GFAP), and α-Smooth Muscle Actin (αSMA) antibodies, to identify factors that influence their development. We found that hepatic stellate cells expressing cRBP-1 are present from the end of the first trimester of gestation and reduce in density throughout gestation. They appear abnormally formed and variably reduced in number in fetuses with abnormal mesothelial Wilms Tumor 1 (WT1) function, diaphragmatic hernia and in ectopic liver nodules without mesothelium. Stellate cells showed similarities to intravascular cells and their presence in a fetus with diaphragm agenesis suggests they may be derived from circulating stem cells. Our observations suggest circulating stem cells as well as mesothelium can give rise to hepatic stellate cells, and that they require normal mesothelial function for their development.

Urine and serum metabolomic profiling reveals that bile acids and carnitine may be potential biomarkers of primary biliary cirrhosis

In order to provide non-invasive, reliable and sensitive laboratory parameters for the diagnosis of primary biliary cirrhosis (PBC), metabolic technology of ultraperformance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF MS) was used to compare small molecule metabolites in blood and urine from patients with PBC and healthy controls. We then screened for bio-markers in the blood and urine of the patients with PBC. Data were processed by Bruker ProfileAnalysis metabonomic software and imported to SIMCA-P software, which utilized principal component analysis (PCA) to create models of patients with PBC and healthy controls. In total, 18 urinary markers were found and the levels of 11 of these urinary markers were elevated in the patients with PBC, whereas the levels of the remaining 7 markers were lower in the PBC group compared to the control group. We also identified 20 blood-based biomarkers in the patients with PBC and the levels of 9 of these markers were higher in the PBC group, whereas the levels of the remaining 11 markers were lower in the patients with PBC compared to the controls. Among these biomarkers, the levels of bile acids increased with the progression of PBC, while the levels of carnitines, such as propionyl carnitine and butyryl carnitine, decreased with the progression of PBC. In conclusion, the findings of the present study suggest that the circulating levels of bile acids and carnitine are differentially altered in patients with PBC.

A Potential Profibrogenic Role of Biliary Epithelium-Derived Cardiotrophin-1 in Pediatric Cholestatic Liver Disease

As a cytokine of the interleukin-6 family, cardiotrophin-1 (CT-1) has been shown to be an important endogenous protector in liver injury. Our study aimed to investigate the role of CT-1 in liver fibrosis in pediatric cholestatic liver disease (PCLD). CT-1 mRNA and protein expression levels were upregulated in PCLD liver biopsy tissues compared with controls. Immunohistochemistry and confocal microscopy of liver sections showed that CT-1 was predominantly expressed by biliary epithelium cells. Serum CT-1 was elevated significantly in the children with PCLD compared with controls. Serum CT-1 levels exhibited a moderate positive correlation with the Scheuer stage of hepatic fibrosis and serum TB levels and a weak correlation with serum ALP levels. In vitro analysis indicated that LX-2 cells preconditioned with CT-1 exhibited significant increments in proliferation and accumulation of extracellular matrix components, while also positively regulating the STAT3 and p38MAPK pathways. In conclusion, biliary epithelium-derived CT-1 may exert a profibrogenic potential in PCLD.

Lack of IL-17 signaling decreases liver fibrosis in murine schistosomiasis japonica

Accumulating evidence has identified the profibrogenic properties of IL-17A in organ fibrosis. However, the role of IL-17A signal in liver fibrosis induced by Schistosoma japonicum infection remains unclear. In this study, we investigated liver fibrosis in wild-type (WT) and IL-17RA(-/-) mice upon S. japonicum infection. Hepatic IL-17A, IL-17C, IL-17E (IL-25), IL-17F, IL-17RA, IL-17RB and IL-17RC transcript levels were determined by RT-PCR. IL-17A(+) cells were analyzed by flow cytometry and confocal microscopy among granuloma cells. Immunostaining of IL-17R was performed on liver sections. Collagen deposition was assessed by Van Gieson's staining. IL-17A, IL-17C, IL-17E, IL-17F, IL-17RA and IL-17RC mRNA levels were dramatically increased in fibrotic livers. Among granuloma cells, CD3(+) and CD3(-) lymphocytes, neutrophils and macrophages were found to express IL-17A. Compared to WT, IL-17RA(-/-) mice displayed attenuated granulomatous inflammation, liver fibrosis, improved liver function and high survival. Meanwhile, α-smooth muscle actin staining and the expression of fibrogenic genes (transforming growth factor β, IL-13 and collagen-I) as well as IL-17A-induced proinflammatory mediators (IL-1β, IL-6, tumor necrosis factor α, CXCL1 and CXCL2) and proteinases (MMP3 and TIMP1) involved in fibrosis were markedly reduced in IL-17RA(-/-) mice. In addition, Th2 cytokines IL-4 and IL-17E (IL-25) were also decreased in IL-17RA(-/-) mice. These results indicated that IL-17A signal contributes to the pathogenesis of liver fibrosis in murine schistosomiasis. This effect was induced possibly by activating hepatic stellate cells and stimulating the release of proinflammatory cytokines and chemokines. Furthermore, the Th2 response was also enhanced by IL-17A signals. Our data demonstrate that IL-17A may serve as a promising target for antifibrotic therapy.

Animal models of gastrointestinal and liver diseases. Animal models of cystic fibrosis: gastrointestinal, pancreatic, and hepatobiliary disease and pathophysiology

Multiple organ systems, including the gastrointestinal tract, pancreas, and hepatobiliary systems, are affected by cystic fibrosis (CF). Many of these changes begin early in life and are difficult to study in young CF patients. Recent development of novel CF animal models has expanded opportunities in the field to better understand CF pathogenesis and evaluate traditional and innovative therapeutics. In this review, we discuss manifestations of CF disease in gastrointestinal, pancreatic, and hepatobiliary systems of humans and animal models. We also compare the similarities and limitations of animal models and discuss future directions for modeling CF.

Circulating microRNAs as noninvasive diagnostic biomarkers of liver disease in children with cystic fibrosis

OBJECTIVES

Cystic fibrosis liver disease (CFLD), resulting from progressive hepatobiliary fibrosis, causes significant morbidity and mortality in up to 20% of children with cystic fibrosis (CF). Both pathogenesis and early detection of CFLD are elusive. Current diagnostic procedures to detect early CFLD and stage fibrosis severity are inadequate. Recent studies highlight a role for microRNAs (miRNAs) in the pathogenesis of many diseases and have suggested that serum miRNAs could be used as diagnostic biomarkers.

METHODS

We profiled circulating serum miRNA levels in patients with CFLD (n = 52), patients with CF without liver disease (CFnoLD, n = 30), and non-CF pediatric controls (n = 20). Extracted RNA was subjected to polymerase chain reaction (PCR) array of 84 miRNAs detectable in human serum. Seven candidate miRNAs identified were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), normalizing data to geNorm-determined stable reference genes, miR-19b and miR-93.

RESULTS

miR-122 was significantly elevated in patients with CFLD versus patients with CFnoLD and controls (P < 0.0001). miR-25 (P = 0.0011) and miR-21 (P = 0.0133) were elevated in patients with CFnoLD versus patients with CFLD and controls. CFLD was discriminated by both miR-122 (area under the curve [AUC] 0.71, P = 0.002) and miR-25 (AUC 0.65, P = 0.026). Logistic regression combining 3 miRNAs (-122, -25, -21) was greatly predictive of detecting CFLD (AUC 0.78, P < 0.0001). A combination of 6 miRNAs (-122, -21, -25, -210, -148a, -19a) distinguished F0 from F3-F4 fibrosis (AUC 0.73, P = 0.04), and miR-210 combined with miR-22 distinguished F0 fibrosis from any fibrosis, that is, F1-F4 (AUC 0.72, P = 0.02).

CONCLUSIONS

These data provide the first evidence of changes to circulating miRNA levels in CF, suggesting that serum-based miRNA analysis may complement and extend current CFLD screening strategies with potential to predict early hepatic fibrosis.

Cystic fibrosis: an update for clinicians. Part 2: hepatobiliary and pancreatic manifestations

This paper, the second in the series, will build on the first and explore the importance of liver and pancreatic manifestations of cystic fibrosis (CF) and the effect on morbidity and mortality of this multifaceted genetic condition. It will also further develop the critical role of the gastroenterologist as part of the multidisciplinary group of clinicians and allied health staff in the effective management of patients with CF.

A new histone deacetylase inhibitor improves liver fibrosis in BDL rats through suppression of hepatic stellate cells

Background and Purpose

Activation of hepatic stellate cells (HSCs) is a crucial step in the pathogenesis of hepatic fibrosis. Histone deacetylase (HDAC) is an attractive target in liver fibrosis because it plays a key role in gene expression and cell differentiation. We have developed a HDAC inhibitor, N-hydroxy-7-(2-naphthylthio)heptanomide (HNHA), and investigated the anti-fibrotic activity of HNHA in vitro and in vivo.

Experimental Approach

We investigated the anti-fibrotic effect of HNHA on mouse and human HSC activation in vitro and in the liver of bile duct-ligated (BDL) rats in vivo using cell proliferation assays, cell cycle analysis, biochemical assay, immunohistochemistry and Western blots. Liver pathology was assessed with histochemical techniques.

Key Results

HNHA inhibited proliferation and arrested the cell cycle via p21 induction in HSCs. In addition, HNHA induced apoptosis of HSCs, which was correlated with reduced COX-2 expression, NF-κB activation and cell death signals. HNHA restored liver function and decreased the accumulation of extracellular matrix in the liver via suppression of HSC activation in BDL rats in vivo. HNHA administration also increased survival in BDL rats.

Conclusions and Implications

HNHA improved liver function, suppressed liver fibrosis and increased survival of BDL rats, accompanied by reduction of cell growth, activation and survival of HSCs. These findings show that HNHA may be a potent anti-fibrosis agent against hepatic fibrosis because of its multi-targeted inhibition of HSC activity in vivo and in vitro.

Activation of nuclear factor kappa B in the hepatic stellate cells of mice with schistosomiasis japonica

Schistosomiasis japonica is a serious tropical parasitic disease in humans, which causes inflammation and fibrosis of the liver. Hepatic stellate cells (HSCs) are known to play an important role in schistosome-induced fibrosis, but their role in schistosome-induced inflammation is still largely unknown. Here, we use a murine model of schistosomiasis japonica to investigate the role that nuclear factor kappa B (NF-κB), a critical mediator of inflammatory responses, plays in schistosome-induced inflammation. We revealed that NF-κB was significantly activated in HSCs at the early stage of infection, but not at later stages. We also show that the expression levels of several chemokines regulated by NF-κB signaling (Ccl2, Ccl3 and Ccl5) were similarly elevated at early infection. TLR4 signaling, one of the strongest known inducers of NF-κB activation, seemed not activated in HSCs post-infection. Importantly, we found that levels of miR-146 (a known negative regulator of NF-κB signaling) in HSCs opposed those of NF-κB signaling, elevating at later stage of infection. These results indicate that HSCs might play an important role in the progression of hepatic schistosomiasis japonica by linking liver inflammation to fibrosis via NF-κB signaling. Moreover, our work suggests that miR-146 appeared to regulate this process. These findings are significant and imply that manipulating the function of HSCs by targeting either NF-κB signaling or miR-146 expression may provide a novel method of treating hepatic schistosomiasis japonica.

Oridonin inhibits hepatic stellate cell proliferation and fibrogenesis

BACKGROUND

Liver fibrosis is a common response to liver injury and, in severe cases, leads to cirrhosis. The hepatic stellate cells (HSCs) become activated after liver injury and play a significant role in fibrogenesis. The activated HSC is characterized by increased proliferation, overexpression of α smooth muscle actin, and excessive production of extracellular matrix (ECM) proteins. Oridonin, a naturally occurring diterpenoid, has been shown to induce apoptosis in liver and gastric cancer cells. However, its effects on the HSC are unknown.

METHODS

We tested the effects of oridonin on the activated human and rat HSC lines LX-2 and HSC-T6, and the human hepatocyte cell line C3A. Transforming growth factor β1 (TGF-β1) was used to stimulate LX-2 cells.

RESULTS

Oridonin significantly inhibited LX-2 and HSC-T6 proliferation. In contrast, oridonin had no antiproliferative effect on C3A cells at our tested range. Oridonin induced apoptosis and S-phase arrest in LX-2 cells. These findings were associated with an increase in p53, p21, p16, and cleaved Poly (ADP-ribose) Polymerase (PARP), and with a decrease in Cyclin-dependent kinase 4 (Cdk4). Oridonin markedly decreased expression of α smooth muscle actin and ECM protein type I collagen and fibronectin, blocked TGF-β1-induced Smad2/3 phosphorylation and type I collagen expression.

CONCLUSIONS

Oridonin induces apoptosis and cell cycle arrest involving the p53-p21 pathway in HSC and appears to be nontoxic to hepatocytes. In addition, oridonin suppressed endogenous and TGF-β1-induced ECM proteins. Thus, oridonin may act as a novel agent to prevent hepatic fibrosis.

Liver disease in cystic fibrosis

The survival of patients with cystic fibrosis (CF) has progressively increased over recent decades, largely attributable to early diagnosis through newborn screening and advances in nutritional and respiratory care. As the life expectancy of patients with CF has improved, non-respiratory complications such as liver disease have become increasingly recognized. Biochemical derangements of liver enzymes in CF are common and may be attributed to a number of specific hepatobiliary abnormalities. Among them, Cystic Fibrosis-associated Liver Disease (CFLD) is clinically the most significant hepatic complication and is believed to have a significant impact on morbidity and mortality. However, there remains much conjecture about the extent of the adverse prognostic implications that a diagnosis of CFLD has on clinical outcomes. The purpose of this review is to give an overview of the current knowledge regarding liver disease in children with CF.

TWEAK and LTβ Signaling during Chronic Liver Disease

Chronic liver diseases (CLD) such as hepatitis B and C virus infection, alcoholic liver disease, and non-alcoholic steatohepatitis are associated with hepatocellular necrosis, continual inflammation, and hepatic fibrosis. The induced microenvironment triggers the activation of liver-resident progenitor cells (LPCs) while hepatocyte replication is inhibited. In the early injury stages, LPCs regenerate the liver by proliferation, migration to sites of injury, and differentiation into functional biliary epithelial cells or hepatocytes. However, when this process becomes dysregulated, wound healing can progress to pathological fibrosis, cirrhosis, and eventually hepatocellular carcinoma. The other key mediators in the pathogenesis of progressive CLD are fibrosis-driving, activated hepatic stellate cells (HSCs) that usually proliferate in very close spatial association with LPCs. Recent studies from our group and others have suggested the potential for cytokine and chemokine cross-talk between LPCs and HSCs, which is mainly driven by the tumor necrosis factor (TNF) family members, TNF-like weak inducer of apoptosis (TWEAK) and lymphotoxin-β, potentially dictating the pathological outcomes of chronic liver injury.

Cellular and chemokine-mediated regulation in schistosome-induced hepatic pathology

In hepatic schistosomiasis, pathology arises when schistosome eggs become lodged in the host liver, evoking an interleukin 4 (IL-4)- and IL-13-mediated dominant CD4(+) Th2 immune response. This response leads to the development of granulomas and fibrosis, with eosinophils, neutrophils, macrophages, hepatic stellate cells, and lymphocytes all identified as major cellular contributors to these events. This review outlines the cellular and molecular mechanisms of hepatic schistosomiasis, with an emphasis on the major cellular components and their release of chemokines. The differences between Schistosoma mansoni- and Schistosoma japonicum-induced hepatic granuloma are also discussed. This comprehensive overview of the processes associated with hepatic schistosomiasis may provide new insights into improved treatment for both schistosomiasis and other granulofibrotic diseases.

Transforming growth factor-β and toll-like receptor-4 polymorphisms are not associated with fibrosis in haemochromatosis

AIM: To investigate the role of genetic polymorphisms in the progression of hepatic fibrosis in hereditary haemochromatosis.

METHODS: A cohort of 245 well-characterised C282Y homozygous patients with haemochromatosis was studied, with all subjects having liver biopsy data and DNA available for testing. This study assessed the association of eight single nucleotide polymorphisms (SNPs) in a total of six genes including toll-like receptor 4 (TLR4), transforming growth factor-beta (TGF-β), oxoguanine DNA glycosylase, monocyte chemoattractant protein 1, chemokine C-C motif receptor 2 and interleukin-10 with liver disease severity. Genotyping was performed using high resolution melt analysis and sequencing. The results were analysed in relation to the stage of hepatic fibrosis in multivariate analysis incorporating other cofactors including alcohol consumption and hepatic iron concentration.

RESULTS: There were significant associations between the cofactors of male gender (P = 0.0001), increasing age (P = 0.006), alcohol consumption (P = 0.0001), steatosis (P = 0.03), hepatic iron concentration (P < 0.0001) and the presence of hepatic fibrosis. Of the candidate gene polymorphisms studied, none showed a significant association with hepatic fibrosis in univariate or multivariate analysis incorporating cofactors. We also specifically studied patients with hepatic iron loading above threshold levels for cirrhosis and compared the genetic polymorphisms between those with no fibrosis vs cirrhosis however there was no significant effect from any of the candidate genes studied. Importantly, in this large, well characterised cohort of patients there was no association between SNPs for TGF-β or TLR4 and the presence of fibrosis, cirrhosis or increasing fibrosis stage in multivariate analysis.

CONCLUSION: In our large, well characterised group of haemochromatosis subjects we did not demonstrate any relationship between candidate gene polymorphisms and hepatic fibrosis or cirrhosis.