CD14 is associated with biliary stricture formation.

UNLABELLED: The pathogenesis of intrahepatic biliary stricture formation in patients with primary sclerosing cholangitis (PSC) or after liver transplantation (LTx) remains elusive. CD14 receptor signaling is a key mediator of the innate immune system; its common genetic variant is associated with alcoholic liver disease. PSC and LTx cohort patients and primary biliary cirrhosis (PBC) control patients were genotyped for the CD14 -260C>T (rs2569190) polymorphism, and genotypes were correlated with long-term clinical outcome. Biliary tissue, bile, and whole blood of PSC patients and healthy controls were screened for markers of the innate immune system and bacterial infection. In 121 PSC patients, the CD14 -260C>T genotype was associated with development of dominant bile duct strictures (P = 0.02). In 365 LTx patients, TT carriers (4.1%) were protected against the formation of nonanastomotic biliary strictures versus CC/CT patients (12.6%; P = 0.01). Chemokine ligand 8 (P = 0.04) and chemokine receptor 6 (P = 0.004) were up-regulated in biliary tissue of PSC patients with the TT versus the CC/CT genotype. Lipopolysaccharide whole-blood stimulation resulted in a significant change in interleukin (IL)-8 (P = 0.05) and IL-12p40 levels (P = 0.04) in healthy control subjects carrying the TT genotype. TT PSC patients were protected against Gram-negative bacterial biliary infection (TT: 0% vs. CC/CT: 22.5%; P = 0.02). Serum-soluble CD14 levels correlated with the CD14 -260C>T genotype (P = 0.02), representing an independent risk indicator of survival in PSC patients (hazard ratio, 0.40; 95% confidence interval, 0.19-0.86; P =0.01). CONCLUSIONS: The function of the innate immune response by CD14 is crucial during biliary infection and stricture formation. The benefits of CD14 signaling modification should be addressed in future studies. (Hepatology 2016;64:843-852).

Tauro-ß-muricholic acid restricts bile acid-induced hepatocellular apoptosis by preserving the mitochondrial membrane potential.

PURPOSE: ß-Muricholic acid (ßMCA) is a trihydroxylated bile acid that constitutes the major bile acid in rat and mouse. ßMCA is more hydrophilic than ursodeoxycholic acid and has been evaluated for dissolution of cholesterol gallstones. Since it is unknown if ßMCA has beneficial effects on hepatocyte cell death we determined the effect of tauro-ßMCA (TßMCA) on apoptosis in vitro. METHODS: Human Ntcp-transfected HepG2 cells and primary hepatocytes from rat and mouse were incubated with the proapoptotic glycochenodeoxycholic acid (GCDCA) as well as the free fatty acid palmitate in the absence and presence of TßMCA. Apoptosis was quantified using caspase 3/7-assays and after Hoechst 33342 staining. The mitochondrial membrane potential (MMP) was measured fluorometrically using JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzimidazol-carbocyaniniodide). Immunoblotting was performed against the proapoptotic Bcl-2-protein Bax. RESULTS: In Ntcp-HepG2 cells, GCDCA markedly increased apoptosis after 4h. Co-incubation with TßMCA reduced apoptosis to 49% (p<0.01 vs. GCDCA, each; n=6). While GCDCA (100µmol/L) reduced the MMP to 34% after 6h, combination treatment with TßMCA restored the MMP to control levels at all time points (n=4). TßMCA also restored breakdown of the MMP induced by palmitate. GCDCA induced a translocation of Bax from the cytosol to mitochondria that was inhibited by simultaneous treatment with TßMCA in eqimolar concentrations. CONCLUSIONS: TßMCA restricts hepatocellular apoptosis induced by low micromolar concentrations of GCDCA or palmitate via inhibition of Bax translocation to mitochondria and preservation of the MMP. Thus, further studies are warranted to evaluate a potential use of TßMCA in ameliorating liver injury in cholestasis.

Analysis of IL2/IL21 gene variants in cholestatic liver diseases reveals an association with primary sclerosing cholangitis.

BACKGROUND/AIMS: The chromosome 4q27 region harboring IL2 and IL21 is an established risk locus for ulcerative colitis (UC) and various other autoimmune diseases. Considering the strong coincidence of primary sclerosing cholangitis (PSC) with UC and the increased frequency of other autoimmune disorders in patients with primary biliary cirrhosis (PBC), we investigated whether genetic variation in the IL2/IL21 region may also modulate the susceptibility to these two rare cholestatic liver diseases. METHODS: Four strongly UC-associated single nucleotide polymorphisms (SNPs) within the KIAA1109/TENR/IL2/IL21 linkage disequilibrium block were genotyped in 124 PBC and 41 PSC patients. Control allele frequencies from 1,487 healthy, unrelated Caucasians were available from a previous UC association study. RESULTS: The minor alleles of all four markers were associated with a decreased susceptibility to PSC (rs13151961: p = 0.013, odds ratio (OR) 0.34; rs13119723: p = 0.023, OR 0.40; rs6822844: p = 0.031, OR 0.41; rs6840978: p = 0.043, OR 0.46). Moreover, a haplotype consisting of the four minor alleles also had a protective effect on PSC susceptibility (p = 0.0084, OR 0.28). A haplotype of the four major alleles was independently associated with PSC when excluding the patients with concomitant inflammatory bowel disease (p = 0.033, OR 4.18). CONCLUSION: The IL2/IL21 region may be one of the highly suggestive but so far rarely identified shared susceptibility loci for PSC and UC.

Role of mitogen-activated protein kinases in tauroursodeoxycholic acid-induced bile formation in cholestatic rat liver.

AIM: Ursodeoxycholic acid exerts anticholestatic effects in various cholestatic disorders and experimental models of cholestasis. Its taurine conjugate (TUDCA) stimulates bile salt secretion in isolated perfused rat livers (IPRL) under physiological, non-cholestatic conditions, in part by mitogen-activated protein kinase (MAPK)-dependent mechanisms. The role of MAPK in the anticholestatic effect of TUDCA, however, is unclear. Therefore, we studied the role of MAPK in the anticholestatic effect of TUDCA in IPRL and isolated rat hepatocytes (IRH) in taurolithocholic acid (TLCA)-induced cholestasis. METHODS: Bile flow, biliary levels of 2,4-dinitrophenyl-S-glutathione (GS-DNP) as a marker of hepatobiliary organic anion secretion and activity of lactate dehydrogenase (LDH) in hepatovenous effluate as a marker of hepatocellular damage in IPRL perfused with TUDCA and/or TLCA were determined in the presence or absence of MAPK inhibitors. In addition, phosphorylation of Erk 1/2 and p38(MAPK) induced by TUDCA and/or TLCA was studied by Western immunoblot in IPRL and IRH. RESULTS: TUDCA-induced bile flow was impaired by the Erk 1/2 inhibitor PD98059 in normal livers (-28%), but not in livers made cholestatic by TLCA. GS-DNP secretion was unaffected by PD98059 under both conditions. TUDCA-induced bile formation and organic anion secretion both in the presence and absence of TLCA were unaffected by the p38(MAPK) inhibitor SB202190. Erk 1/2 phosphorylation in liver tissue was unchanged after bile salt exposure for 70 min, but was transiently enhanced by TUDCA in IRH. CONCLUSION: MAPK do not mediate the anticholestatic effects of TUDCA in TLCA-induced cholestasis.

[A 27-year-old patient with recurrent Fever]. / 27-jähriger Patient mit rezidivierendem Fieber.

BACKGROUND: In spite of a decreasing incidence of tuberculosis in highly industrialized countries, an obvious increase of the disease is observed worldwide. In times of progressing international migration, the early detection of tuberculosis is also becoming important in Germany. The diagnosis, however, is often impaired by unspecific symptomatology and ambiguous imaging results. CASE REPORT: A 27-year-old patient from Iraq presented with unclear recurring and antibiotic-resistant fever and inconspicuous thoracic X-ray. Only by thoracic computed tomography, markedly necrotizing mediastinal lymph nodes could be detected. Following lymph node biopsy and histologic investigation, the diagnosis of mediastinal lymph node tuberculosis could be ascertained. Test-adjusted antituberculotic combination treatment resulted in a normalization of body temperature and cessation of complaints. Starting from the case report presented, the importance of various investigative methods for the quick and secure diagnosis of tuberculosis and subsequent therapy are discussed. CONCLUSION: Unclear febrile disease even in young patients with an inconspicuous conventional thoracic X-ray may be caused by tuberculosis. In this situation, early extension of imaging diagnostics appears to be advantageous.