Conditional depletion of macrophages ameliorates cholestatic liver injury and fibrosis via lncRNA-H19.

Although macrophages are recognized as important players in the pathogenesis of chronic liver diseases, their roles in cholestatic liver fibrosis remain incompletely understood. We previously reported that long noncoding RNA-H19 (lncRNA-H19) contributes to cholangiocyte proliferation and cholestatic liver fibrosis of biliary atresia (BA). We here show that monocyte/macrophage CD11B mRNA levels are increased significantly in livers of BA patients and positively correlated with the progression of liver inflammation and fibrosis. The macrophages increasingly infiltrate and accumulate in the fibrotic niche and peribiliary areas in livers of BA patients. Selective depletion of macrophages using the transgenic CD11b-diphtheria toxin receptor (CD11b-DTR) mice halts bile duct ligation (BDL)-induced progression of liver damage and fibrosis. Meanwhile, macrophage depletion significantly reduces the BDL-induced hepatic lncRNA-H19. Overexpression of H19 in livers using adeno-associated virus serotype 9 (AAV9) counteracts the effects of macrophage depletion on liver fibrosis and cholangiocyte proliferation. Additionally, both H19 knockout (H19-/-) and conditional deletion of H19 in macrophage (H19ΔCD11B) significantly depress the macrophage polarization and recruitment. lncRNA-H19 overexpressed in THP-1 macrophages enhance expression of Rho-GTPase CDC42 and RhoA. In conclusions, selectively depletion of macrophages suppresses cholestatic liver injuries and fibrosis via the lncRNA-H19 and represents a potential therapeutic strategy for rapid liver fibrosis in BA patients.

The ameliorative effect of niclosamide on bile duct ligation induced liver fibrosis via suppression of NOTCH and Wnt pathways.

Liver fibrosis is the conjoint consequence of almost all chronic liver diseases. Cholestatic liver injury is a significant stimulus for fibrotic liver. This study was conducted to investigate the hepatoprotective effect of niclosamide as a NOTCH inhibitor and on the Wnt pathway against cholestatic liver fibrosis (CLF) which was experimentally induced by bile duct ligation (BDL). Rats were randomly divided into five main groups (6 per group): sham, BDL, BDL/niclosamide 5, BDL/niclosamide 10 and niclosamide 10 only group. Niclosamide was administered intraperitoneally (i.p.) for 4 weeks starting at the same day of surgery at doses 5 and 10 mg/kg. Liver function, cholestasis, oxidative stress, inflammation, liver fibrosis, NOTCH signaling pathway and Wnt pathway markers were assessed. Niclosamide (5 and 10 mg/kg) significantly reduced liver enzymes levels, oxidative stress, inflammation and phosphorylated signal transducer and activator of transcription3 (p-STAT3). Niclosamide (5 and 10 mg/kg) also significantly reduced NOTCH pathway (Jagged1, NOTCH2, NOTCH3, HES1, SOX9), Wnt pathway (Wnt5B, and Wnt10A), and fibrosis (transforming growth factor-beta1 (TGF-ß1), alpha smooth muscle actin (α-SMA) and collagen deposition with more prominent effect of the higher dose 10 mg/kg. So, this study presents nicloamide as a promising antifibrotic agent in CLF through inhibition of NOTCH and Wnt pathways.

Serum levels of a cell death biomarker predict the development of cirrhosis-related conditions in primary biliary cholangitis.

Non-invasive predictors for the development of cirrhosis-related conditions are needed for patients with primary biliary cholangitis (PBC). We investigated the association between cytokeratin-18 fragments (M30 and M65) and liver histology, treatment response and the development of cirrhosis-related conditions in patients with PBC. We retrospectively reviewed the clinical data of 111 individuals with biopsy-proven PBC. Serum M30 and M65 levels were measured using stored sera. M30 were significantly decreased after treatment, but there was no significant change in the M65 levels. M65 was significantly higher in non-responders according to the Paris-I and Paris-II definitions. In the multivariate analysis, high levels of M65 were significantly associated with advanced Scheuer stage (odds ratio 5.86; 95% confidence interval 0.55-22.2; P = 0.009) and with the development of cirrhosis-related conditions (hazard ratio 3.94; 95% confidence interval: 1.06-14.5, P = 0.039). Among PBC patients without cirrhosis, those with high serum M65 levels at baseline were at higher risk of developing cirrhosis-related conditions (log-rank test; P = 0.001). High levels of serum M65 may be a non-invasive and early predictor of the development of cirrhosis-related conditions in PBC patients. Our findings may help initiate therapies earlier for those at risk for cirrhosis.

Sildenafil protects against bile duct ligation induced hepatic fibrosis in rats: Potential role for silent information regulator 1 (SIRT1).

Hepatic fibrosis is a potential health problem that may end with life-threatening cirrhosis and primary liver cancer. Recent studies point out to the protective effects of silent information regulator1 (SIRT1), against different models of organs fibrosis. This work aimed to investigate the possible protective effect of sildenafil (SIRT1 activator) against hepatic fibrosis induced by bile duct ligation (BDL). Firstly, three different doses of sildenafil (5, 10, 20mg/kg/day) were investigated; to detect the most protective one against BDL induced liver dysfunction and hepatic fibrosis. The most protective dose is then used; to study its effect on BDL induced SIRT1 downregulation, imbalance of oxidant/antioxidant status, increased inflammatory cytokines and fibrosis. Sildenafil (20mg/kg/day) was the most protective one, it caused upregulation of SIRT1, reduction of hepatic malondialdehyde (MDA) content, increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemeoxygenease (HO)-1, reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hepatic content of tumor necrosis factor-α (TNF-α) and nuclear factor κB (NFκB) expression & content displayed significant reductions with sildenafil treatment, Furthermore, sildenafil caused marked reductions of transforming growth factor (TGF)-ß content, expression of plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), α-smooth muscle actin (α-SMA), fibronectin, collagen I (α1) and hydroxyproline content. However, sildenafil protective effects were significantly reduced by co-administration of EX527 (SIRT1 inhibitor). Our work showed, for the first time that, sildenafil has promising protective effects against BDL induced liver dysfunction and hepatic fibrosis. These effects may be, in part, mediated by up regulation of SIRT1.

Colangitis biliar primaria. Parte 1. Actualización: generalidades, epidemiología, factores involucrados, fisiopatología y manifestaciones clínicas / Primary biliary cholangitis. Part 1. State of the art, epidemiology, physiopathology and clinical manifestations

La colangitis biliar primaria (CBP), es una colangiopatía crónica caracterizada por la destrucción selectiva de las células epiteliales biliares de conductos hepáticos de pequeño y mediano calibre, que afecta principalmente a mujeres. Los principales síntomas son la fatiga y el prurito, sin embargo, gran porcentaje de los pacientes pueden ser asintomáticos. El diagnóstico se basa en anticuerpos antimitocondriales (AMA) con títulos >1:40, fosfatasa alcalina >1,5 veces del límite superior normal por más de 24 semanas e histología hepática compatible con la patología. Se asocia con múltiples enfermedades principalmente de carácter autoinmune extra hepáticas, enfermedades tiroideas, óseas, entre otras. El tratamiento de primera línea es el ácido ursodesoxicólico (AUDC) que a pesar que no cura la enfermedad, mejora las pruebas del perfil hepático, así como el retraso en la progresión a cirrosis. Actualmente se encuentran en estudio nuevos tratamientos y terapias adyuvantes. El propósito de esta revisión es ofrecer una actualización de este tema que se presenta en los servicios de medicina interna y gastroenterología; para su realización se conformó un equipo interdisciplinario que desarrolló una búsqueda en la base Medline a través de PubMed con las palabras claves correspondientes y se procedió a una lectura crítica y analítica de títulos, resúmenes y textos completos para el filtro, extracción y síntesis de la información encontrada

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the database Medline thorough PubMed with the key words describe below, we made a critical lecture of the titles and abstracts of each article to write this paper

[Primary biliary cholangitis. Part 1. State of the art, epidemiology, physiopathology and clinical manifestations]. / Colangitis biliar primaria. Parte 1. Actualización: generalidades,epidemiología, factores involucrados, fisiopatología y manifestaciones clínicas.

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the database Medline thorough PubMed with the key words describe below, we made a critical lecture of the titles and abstracts of each article to write this paper.

Statin pretreatment inhibits the lipopolysaccharide-induced epithelial-mesenchymal transition via the downregulation of toll-like receptor 4 and nuclear factor-κB in human biliary epithelial cells.

BACKGROUND AND AIM: Epithelial-mesenchymal transition (EMT) of biliary epithelial cells (BECs) plays an important role in biliary fibrosis. This study investigated the effects of simvastatin on the lipopolysaccharide (LPS)-induced EMT and related signal pathways in BECs. METHODS: Biliary epithelial cells were exposed to LPS (2 µg/mL) or transforming growth factor ß1 (TGF-ß1) (5 ng/mL) for 5 days. The EMT was assessed by a gain of mesenchymal cell markers (vimentin, N-cadherin, slug, and Twist-1) and a loss of epithelial cell markers (E-cadherin). The effects of simvastatin on the EMT induced by LPS or TGF-ß1 were determined by the changes in the levels of EMT markers and TLR4 and in the c-Jun N-terminal kinase (JNK), p38, and nuclear factor-κB (NF-κB) signaling pathways. RESULTS: Compared with the BECs treated with LPS alone, co-treatment with simvastatin and LPS induced an increase in the expression of E-cadherin and decreases in the expression levels of mesenchymal cell markers. The LPS-induced TLR4 expression level was slightly decreased by co-treatment with simvastatin. LPS-induced BEC growth was markedly inhibited by co-treatment with simvastatin. Furthermore, pretreatment with simvastatin inhibited the LPS-induced EMT in BECs by downregulating NF-κB and JNK phosphorylation. The suppressive effects of simvastatin pretreatment on the induction of the EMT by TGF-ß1 were also demonstrated in H69 cells. CONCLUSIONS: Our results demonstrate that LPS or TGF-ß1 promote the EMT in BECs that that pretreatment with simvastatin inhibited the induced EMT by downregulating toll-like receptor 4 and NF-κB phosphorylation. This finding suggests that simvastatin can be considered a new agent for preventing biliary fibrosis associated with the EMT of BECs.

Protective effect of bicyclol against bile duct ligation-induced hepatic fibrosis in rats.

AIM: To evaluate the protective effect of bicyclol against bile duct ligation (BDL)-induced hepatic fibrosis in rats. METHODS: Sprague-Dawley male rats underwent BDL and sham-operated animals were used as healthy controls. The BDL rats were divided into two groups which received sterilized PBS or bicyclol (100 mg/kg per day) orally for two consecutive weeks. Serum, urine and bile were collected for biochemical determinations. Liver tissues were collected for histological analysis and a whole genome oligonucleotide microarray assay. Reverse transcription-polymerase chain reaction and Western blotting were used to verify the expression of liver fibrosis-related genes. RESULTS: Treatment with bicyclol significantly reduced liver fibrosis and bile duct proliferation after BDL. The levels of alanine aminotransferase (127.7 ± 72.3 vs 230.4 ± 69.6, P < 0.05) and aspartate aminotransferase (696.8 ± 232.6 vs 1032.6 ± 165.8, P < 0.05) were also decreased by treatment with bicyclol in comparison to PBS. The expression changes of 45 fibrogenic genes and several fibrogenesis-related pathways were reversed by bicyclol in the microarray assay. Bicyclol significantly reduced liver mRNA and/or protein expression levels of collagen 1a1, matrix metalloproteinase 2, tumor necrosis factor, tissue inhibitors of metalloproteinases 2, transforming growth factor-ß1 and α-smooth muscle actin. CONCLUSION: Bicyclol significantly attenuates BDL-induced liver fibrosis by reversing fibrogenic gene expression. These findings suggest that bicyclol might be an effective anti-fibrotic drug for the treatment of cholestatic liver disease.

Switching from tacrolimus to cyclosporine A to prevent primary biliary cirrhosis recurrence after living-donor liver transplantation.

Recurrence of primary biliary cirrhosis (PBC) after liver transplantation has been shown to negatively affect graft and patient survival. Recently, protective effects of cyclosporine A against PBC recurrence after liver transplantation have been reported. Participants were 4 patients who underwent living-donor liver transplantation (LDLT) for end-stage liver disease due to PBC. Tacrolimus was used for initial immunosuppression, and this was switched to cyclosporine A at least 3 months after liver transplantation. Targeted trough level of cyclosporine A was 20 times that of tacrolimus. We assessed liver and renal function, as well as antimitochondrial M2 antibody for recipients prior to LDLT, as well as before and after switching immunosuppressive agents. Patients were 1 man and 3 women, and they were ages 45 to 47 years at LDLT. Timing of switching from tacrolimus to cyclosporine A was 13, 3, 7, and 4 months respectively after liver transplantation, and all 4 patients have been on cyclosporine A without adverse effects at 20 to 46 months after transplantation. In 2 of 4 patients who had high titers of antimitochondrial M2 antibody before transplantation, antibody titer did not elevate after LDLT. In the other 2 patients without elevation of antimitochondrial M2 antibody, the titer did not turn positive. Switching from tacrolimus to cyclosporine A was possible without medical problems, and all patients exhibit no recurrence of PBC. Cyclosporine A may be useful for prevention of PBC recurrence after LDLT.

Secondary biliary cirrhosis in the rat is prevented by decreasing NF-κB nuclear translocation and TGF-ß expression using allopurinol, an inhibitor of xanthine oxidase.

Allopurinol is an inhibitor of xanthine oxidase (XO), and XO is an enzyme that generates great amounts of reactive oxygen species. The aim of this work was to evaluate the efficacy of allopurinol to prevent experimental cirrhosis. Fibrosis and cirrhosis were induced by common bile duct ligation (BDL) for 4 weeks in rats. Animals were divided into 4 groups: sham-operated rats (SHAM); BDL group; BDL plus allopurinol (100 mg·kg⁻¹, p.o.), and SHAM plus allopurinol treatment. Alanine aminotransferase, γ-glutamyl transpeptidase, and alkaline phosphatase were increased in BDL rats but were preserved normal by allopurinol. XO activity was prevented by allopurinol; however, lipophilic and hydrophilic oxidative stress was not prevented by the drug. Allopurinol partially suppresses nuclear factor-κB (NF-κB) nuclear translocation and transforming growth factor-ß (TGF-ß) expression, and increased the active form of matrix metalloproteinase-13 (MMP-13). Moreover, collagen production induced by BDL was partially but significantly reduced by allopurinol. These findings suggest that allopurinol possesses a hepatoprotective effect probably by modulating proteins such as NF-κB, TGF-ß, and MMP-13, helping to protect against liver damage induced by chronic cholestasis and a mechanism independent of oxidative stress.

[Liver disease recurrence after liver transplantation]. / Recurrencia de la enfermedad hepática primaria después del trasplante hepático.

Liver transplantation has become a standard option in the management of patients with end-stage liver disease. It is now evident that the most common etiology of long-term graft dysfunction is the recurrence of the primary liver disease. Autoimmune liver disorders such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis recur between 15 to 30% of the graft recipients. The clinical expression of this recurrence tends to be milder; the diagnosis is only established in many patients by findings in the liver biopsy. This milder clinical expression may be due to the use of immunosuppressive therapy for the prevention of organ rejection and it may also be modulating immune mechanisms that underlie these conditions. The recurrence of hepatitis C virus infection is characterized by an accelerated progression towards cirrhosis and hepatic failure due to the lack of an effective immunoprophylaxis program and an effective antiviral therapy. The recurrence of hepatitis B is uncommon due to the availability on an effective immunoprophylaxis program with effective antiviral agents. The familial amyloidotic polyneuropathy is a genetic condition residing in the hepatocyte that produces a mutation of transthyretin; this abnormal protein is deposited in peripheral nerves, gastrointestinal tract, heart, and kidneys. The liver from these patients, apart from producing this abnormal protein, is otherwise normal, and has been used as an organ for recipients in dire need of a liver transplant, such as patients with hepatocellular carcinoma. This approach is known as domino liver transplantation. As these recipients are followed long term, they may develop de novo amyloidosis. In summary, the underlying liver condition that led to endstage liver disease and liver transplantation may recur after liver transplantation. The clinical expression of the recurrence of the hepatic disease is modulated by the immunosuppression program unless we have an effective immunoprophylaxis and antiviral agents such as in hepatitis B.

Recurrencia de la enfermedad hepática primaria después del trasplante hepático / Liver disease recurrence after liver transplantation

Liver transplantation has become a standard option in the management of patients with end-stage liver disease. It is now evident that the most common etiology of long-term graft dysfunction is the recurrence of the primary liver disease. Autoimmune liver disorders such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis recur between 15 to 30 percent of the graft recipients. The clinical expression of this recurrence tends to be milder; the diagnosis is only established in many patients by fndings in the liver biopsy. This milder clinical expression may be due to the use of immunosuppressive therapy for the prevention of organ rejection and it may also be modulating immune mechanisms that underlie these conditions. The recurrence of hepatitis C virus infection is characterized by an accelerated progression towards cirrhosis and hepatic failure due to the lack of an effective immunoprophylaxis program and an effective antiviral therapy. The recurrence of hepatitis B is uncommon due to the availability on an effective immunoprophylaxis program with effective antiviral agents. The familial amyloidotic polyneuropathy is a genetic condition residing in the hepatocyte that produces a mutation of transthyretin; this abnormal protein is deposited in peripheral nerves, gastrointestinal tract, heart, and kidneys. The liver from these patients, apart from producing this abnormal protein, is otherwise normal, and has been used as an organ for recipients in dire need of a liver transplant, such as patients with hepatocellular carcinoma. This approach is known as “domino” liver transplantation. As these recipients are followed long term, they may develop de novo amyloidosis. In summary, the underlying liver condition that led to endstage liver disease and liver transplantation may recur after liver transplantation. The clinical expression of the recurrence of the hepatic disease is modulated by the immunosuppression...

Incremento del factor de crecimiento transformante B en las lesiones de vías biliares luego de la colecistectomía / Hepatic and systemic transforming growth factor B expression in post-cholecystectomy bile duct injury

Introducción: La lesión de vías biliares es un problema clínico importante, se manifiesta por activación de moléculas inflamatorias y fibrogénicas. Objetivo: Evaluar la expresión hepática y sistémica del factor de crecimiento transformante beta (TGF-ß) en la lesión de vías biliares luego de la colecistectomía. Pacientes y métodos: Grupo 1 (control), 3 sujetos sanos; grupo 2, 37 pacientes con lesión de vías biliares poscolecistectomía. Al grupo 2 se le realizó reconstrucción biliodigestiva a 8 semanas de la lesión. Se midió en suero la expresión de TGF-ß por ELISA. La biopsia hepática se sometió a análisis histopatológico e inmuhistoquímica con el anticuerpo anti-TGF-ß, se cuantificó la expresión mediante soporte digital AxioVision 4.6.3. Resultados: El promedio de los niveles séricos de TGF-ß del grupo 1 fue 904.49 ± 227.24 pg/ml contra el grupo 2 con 44 365.71 ± 20 260.61 pg/ml, 48 veces más expresión (p < 0.0001, t de Student). La actividad inflamatoria hepática fue diversa en el grupo 2, mostró grado 4 en 4 (11%); de 3, 15 (40%); de 2, 18 (49%). En el grupo 1 la actividad inflamatoria fue de grado 0. La expresión hepática del TGF-ß en el grupo 1, es de un promedio de 537.15 ± 330.96 μm2; en el grupo 2, 1 768.09 ± 1 024.50 μm2, 2.3 más expresión (p = 0.0473, t de Student). Conclusión: La expresión hepática y sistémica de TGF-ß se encontró aumentada en los pacientes con lesión de vías biliares poscolecistectomía.

An acqueous extract of Bidens pilosa L. protects liver from cholestatic disease: experimental study in young rats / Um extrato aquoso de Bidens pilosa L. protege o fígado da doença colestática: estudo experimental em ratos jovens

PURPOSE: To test the hepatoprotective effect of water extract from Bidens Pilosa L. (BPE) in cholestatic liver disease induced by ligature and resection of the common bile ducts (LRBD) in young rats. METHODS: We studied four groups of ten 21 days old (P21) Wistar rats, Group SW: sham operation and water; Group SD: sham operation and BPE (160 mg of fresh leaves/100 g of body weight/day); Group LW: LRBD and water and Group LD: LRBD and BPE daily. Pentobarbital sleeping time (PST) and serum activities of aspartate aminotransferase (AST) and of alanine aminotransferase (ALT) were determined after the sacrifice (P70). A Ruwart's score for hepatic fibrosis (RS) was given to each animal. Were employed two way ANOVA and the test of Tukey or a non-parametric test for multiple comparisons. RESULTS: There were statistically significant differences between LW and LD in the measurements of the PST ((means LW=390; LD=173), AST (means LW=8, LD=5), ALT (medians LW=2; LD=1) e RS (medians LW=2; LD=1). CONCLUSION: BPE could be used in the phytotherapy of the hepatic damage induced by chronic obstructive cholestasis, because protects liver function, decreases the rate of necrosis and liver fibrosis in cholestatic liver disease.

OBJETIVO: Testar o efeito hepatoprotetor do extrato aquoso de Bidens pilosa L. (EBP) na doença hepática induzida pela ligadura e ressecção do ducto biliar comum (LRDBC) em ratos jovens. MÉTODOS: Estudamos ratos Wistar com 21º. dia de vida (P21) divididos em quatro grupos de 10 animais, Grupo SA: operação simulada e água; Grupo SD: operação simulada e EBP (160mg de folhas frescas/100g de peso corporal/dia); Grupo LA: LRDBC e água e Grupo LD: LRDBC e EBP diariamente. O tempo de sono por pentobarbital (TSP), aspartato (AST) e alanina (ALT) aminotransferase foram determinadas após o sacrifício (P70). O Score de Ruwart (SR) para fibrose hepática foi atribuído para cada animal. Foi realizada análise de variância com dois fatores e pelo teste de Tukey para comparações múltiplas ou por teste não paramétrico. RESULTADOS: Houve diferença estatisticamente significativa entre LA e LD nas variáveis: TSP (médias LA=390; LD=173), AST (médias LA=8, LD=5), ALT (medianas LA=2; LD=1) e SR (medianas LA=2; LD=1). CONCLUSÃO: EBP poderá ser empregado na fitoterapia da doença hepática induzida pela colestase obstrutiva crônica, pois protege a função hepática, diminui a velocidade de necrose e a intensidade da fibrose hepática na obstrução biliar extra-hepática.

Deletion of interleukin-12p40 suppresses autoimmune cholangitis in dominant negative transforming growth factor beta receptor type II mice.

UNLABELLED: Our laboratory has reported that mice that express a dominant negative form of transforming growth factor beta receptor restricted to T cells (dnTGFbetaRII) develop an inflammatory biliary ductular disease with elevated serum levels of interleukin (IL)-12p40 and other proinflammatory cytokines and antimitochondrial autoantibodies (AMAs) closely resembling human primary biliary cirrhosis (PBC). We have used this mouse model to address the potential mechanisms of immunomodulation of liver disease by creating two unique genetic strains: IL-12p40 knockout (KO)-dnTGFbetaRII mice and IFN-gamma KO-dnTGFbetaRII mice. The two colonies of genetically modified mice-and, for purposes of controls, the dnTGFbetaRII mice-were monitored for liver immunopathology, AMAs, and intrahepatic cytokine production. Disease expression in the IFN-gamma KO-dnTGFbetaRII mice, including liver immunopathology, were similar to those of dnTGFbetaRII mice, whereas the IL-12p40 KO-dnTGFbetaRII mice had a dramatic reduction in histological autoimmune cholangitis and significant decreases in levels of intrahepatic proinflammatory cytokines, but similar levels of AMAs compared with dnTGFbetaRII controls. CONCLUSION: These data indicate that in this mouse model of PBC, signaling by way of IL-12p40 is an essential requirement for the development of autoimmune cholangitis. The results of these studies will play an important role in identifying pathways and reagents that will selectively inhibit IL-12 signaling for the outlining of future therapeutic strategies for human PBC.

Suplementação com ácido ascórbico tem efeito citoprotetor na cirrose biliar secundária: estudo experimental em ratos jovens / Ascorbic acid supplementation has a cytoprotective effect on secondary biliary cirrhosis: experimental study in young rats

OBJETIVO: Testar se a suplementação com ácido ascórbico tem algum afeito citoprotetor em um modelo de cirrose biliar secundária em ratos jovens. MÉTODOS: Foram estudados 40 ratos Wistar desmamados no 21º dia pós-natal. Cada grupo de 10 foi submetido a um dos seguintes quatro tratamentos, até o 49º dia pós-natal, quando foram submetidos a eutanásia: 1) LC - ligadura dupla e ressecção do ducto biliar comum e administração diária de ácido ascórbico [100 mg/g de peso corporal (pc)]; 2) LA - ligadura dupla e ressecção do ducto biliar comum e administração diária de veículo aquoso (1 mL/g pc); 3) SC - operação simulada e administração diária de ácido ascórbico (100 mg/g pc); 4) SA - ligadura dupla e ressecção do ducto biliar comum e administração diária de veículo aquoso (1 mL/g pc). Os ratos eram pesados diariamente. No 27º dia pós-operatório, eles receberam injeção intraperitoneal de 1,5 mg/g pc de pentobarbital sódico, e o tempo de sono induzido pelo pentobarbital foi medido. Coletou-se sangue para determinação de atividade sérica de alanina aminotransferase e de aspartato aminotransferase, níveis de albumina e globulina séricas, e o fígado foi analisado quanto à conteúdo de água e gordura. Os dados foram submetidos à ANOVA two-way, e comparações pareadas entre grupos foram testadas com o método de SNK. O nível de significância foi estabelecido em 0,05. RESULTADOS: A suplementação com ácido ascórbico atenuou os efeitos da colestase: reduziu o tempo de anestesia pelo pentobarbital, globulina sérica e o conteúdo de gordura no fígado. CONCLUSÕES: Nossos resultados corroboram a hipótese de que a suplementação com ácido ascórbico tem um efeito citoprotetor na cirrose biliar secundária.

OBJECTIVE: To test whether ascorbic acid supplementation has any cytoprotective effect on a model of secondary biliary cirrhosis in young rats. METHODS: We studied 40 Wistar rats weaned at the 21st postnatal day. Each group of 10 was subjected to one of the following four treatments, until 49th postnatal day, when they suffered euthanasia: 1) LC-double ligature and resection of the common bile duct and daily administration of ascorbic acid [100 mg/g of body weight (bw)]; 2) LA-double ligature and resection of the common bile duct and daily administration of aqueous vehicle (1 mL/g bw); 3) SC-sham operation and daily administration of ascorbic acid (100 mg/g bw); 4) SA-double ligature and resection of the common bile duct and daily administration of aqueous vehicle (1 mL/g bw). The rats were weighed daily. On the 27th day after the operation they received an intra-peritoneal injection of 1.5 mg/g bw of sodium pentobarbital, and the pentobarbital sleeping time was measured. Blood was collected for serum alanine aminotransferase and aspartate aminotransferase activity measurements, serum albumin and globulin concentrations, and the liver was assessed for liver water and fat content. Data were submitted to two-way ANOVA and paired comparisons between groups were tested using the SNK method. Significance level was set at 0.05. RESULTS: Ascorbic acid supplementation attenuated the effects of cholestasis: decreased the pentobarbital sleeping time, serum globulin, and the liver fat content. CONCLUSIONS: Our results corroborate the hypothesis that ascorbic acid supplementation has a cytoprotective effect in secondary biliary cirrhosis.

The medical management of primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a rare, chronic cholestatic liver disease of uncertain etiology characterized by the destruction of the intrahepatic and/or extrahepatic ducts through inflammation and fibrosis. This ultimately leads to biliary complications including cirrhosis, cholangiocarcinoma, and eventually death. Given the uncertainty surrounding the pathogenesis of the disease, a number of different medical therapies have been studied in the treatment of PSC. However, there currently are no effective medical therapies known to halt the progression of disease. The only definitive therapy for PSC is liver transplantation. This review will primarily focus on the medical approaches that have been studied for the treatment of PSC as well as on the management of symptoms commonly associated with the disease.

Wnt antagonism inhibits hepatic stellate cell activation and liver fibrosis.

Activation of hepatic stellate cells (HSC), a key event in liver fibrosis, is caused by diminished adipogenic transcription. This study investigated whether Wnt signaling contributes to "antiadipogenic" activation of HSC and liver fibrogenesis. Culture-activated HSC from normal rats and HSC from cholestatic rat livers were examined for expression of Wnt, Frizzled (Fz) receptors, and coreceptors by quantitative PCR. Wnt signaling was assessed by nuclear beta-catenin and T cell factor (TCF) promoter activity. Dickkopf-1 (Dkk-1), a Wnt coreceptor antagonist, was transduced by an adenoviral vector to assess the effects of Wnt antagonism on culture activation of HSC and cholestatic liver fibrosis in mice. Messenger RNA for canonical (Wnt3a and 10b) and noncanonical (Wnt4 and 5a) Wnt genes, Fz-1 and 2, and coreceptors [low-density lipoprotein-receptor-related protein (LRP)6 and Ryk] are increased approximately 3-12-fold in culture-activated HSC compared with quiescent HSC. The nuclear beta-catenin level and TCF DNA binding are markedly increased in activated HSC. TCF promoter activity is stimulated with Wnt1 but inhibited by Chibby, a protein that blocks beta-catenin interaction with TCF, and by Dkk-1. Dkk-1 enhances peroxisome proliferator-activated receptor-gamma (PPARgamma)-driven PPAR response element (PPRE) promoter activity, a key adipogenic transcriptional parameter, abrogates agonist-stimulated contraction, and restores HSC quiescence in culture. High expression of Dkk-1 increases apoptosis of cultured HSC. Expression of Wnt and Fz genes is also induced in HSC isolated from experimental cholestatic liver fibrosis, and Dkk-1 expression ameliorates this form of liver fibrosis in mice. These results demonstrate antiadipogenic Wnt signaling in HSC activation and therapeutic potential of Wnt antagonism for liver fibrosis.

High-dose ursodeoxycholic acid for the treatment of primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease that results in progressive fibrosis of intrahepatic and extrahepatic bile ducts. No effective therapy currently exists for this disease. Ursodeoxycholic acid (UDCA), a hydrophilic bile acid, is the most promising treatment option because of its benign side effect profile and documented benefit in the treatment of other cholestatic liver diseases, including primary biliary cirrhosis. Multiple studies using standard-dosage (8-15 mg/kg/d) and high-dosage (20-30 mg/kg/d) UDCA generally show improvement in liver chemistries in PSC patients, and several show improvement in liver histology. However, the majority of trials using UDCA in PSC are underpowered and fail to show improvements in clinically relevant endpoints, such as delayed progression to cirrhosis, portal hypertension, liver transplantation, development of cholangiocarcinoma, or death.