Altered Microbiota Diversity and Bile Acid Signaling in Cirrhotic and Noncirrhotic NASH-HCC.

OBJECTIVES: The precipitous increase in nonalcoholic steatohepatitis (NASH) is accompanied by a dramatic increase in the incidence of NASH-related hepatocellular carcinoma (HCC). HCC in NASH has a higher propensity to arise without pre-existing cirrhosis compared with other chronic liver diseases. METHODS: To identify the potential links between liver and gut in NASH-related hepatocarcinogenesis, we compared the gut microbiota and mediators of bile acid (BA) signaling in the absence or presence of cirrhosis through the analysis of stool and serum samples from patients with NASH non-HCC and NASH-HCC and healthy volunteers. RESULTS: Serum levels of total and individual BA were higher in NASH compared with healthy controls. Furthermore, serum levels of the primary conjugated BAs glycine-conjugated cholic acid, taurine-conjugated cholic acid, glycine-conjugated chenodeoxycholic acid, and taurine-conjugated chenodeoxycholic acid were significantly increased in cirrhotic vs noncirrhotic patients, independent of the occurrence of HCC. By contrast, serum FGF19 levels were higher in patients with NASH-HCC and associated with tumor markers as well as an attenuation of BA synthesis. Specific alterations in the gut microbiome were found for several bacteria involved in the BA metabolism including Bacteroides and Lactobacilli. Specifically, the abundance of Lactobacilli was associated with progressive disease, serum BA levels, and liver injury in NASH and NASH-HCC. DISCUSSION: Here, we demonstrate a clear association of the altered gut microbiota and primary conjugated BA composition in cirrhotic and noncirrhotic patients with NASH-HCC. Microbiota-associated alterations in BA homeostasis and farnesoid X receptor signaling, via FGF19, might thus contribute to fibrogenesis, liver injury, and tumorigenesis in NASH-HCC.

Structure-activity relationship and studies on the molecular mechanism of leishmanicidal N,C-coupled arylisoquinolinium salts.

Alternative drugs against leishmaniasis are desperately needed. Antimonials, the main chemotherapeutic tool, cause serious side effects and promote chemoresistance. We previously demonstrated that representatives of N,C-linked arylisoquinolines are promising leishmanicidal drug candidates. We now performed structure-activity relationship studies varying the aryl portion of our lead substrate. The new series of compounds show an enhanced selectivity against Leishmania major in comparison to their major host cell, the macrophage. Our results suggest that the arylisoquinolinium salts decrease the macrophage infection rate acting directly on the intracellular parasites. However, the activity of the 4'-i-propyl derivative might also involve the modulation of cytokine and nitric oxide production by host macrophages. Additionally, this isoquinoline acts synergistically with amphotericin B and does not interact with drug-metabolizing cytochrome P450 enzymes involved in the metabolism of antileishmanial drugs. The results demonstrate that the newly synthesized structurally simplified N,C-coupled arylisoquinolinium salts are promising candidates to be considered as leishmanicidal pharmacophores.