Effects of retrorsine on mouse hepatocyte proliferation after liver injury

AIM： To study the effect of retrorsine on mouse hepatocyte proliferation. METHODS： Mice and rats were treated respectively with two injections of retrorsine （as retrosine-treated group） or saline （as non-treated group） at 2 wk intervals. They received a single injection of carbon tetrachloride （CCh） 4 wk later. On d 0, 1, 2, 3, 4, 6, 15 after CCh administration, the animals were killed and their livers were excised. Hematoxylin and eosin （HE） staining and Ki-67 antibody immunohistochemical analysis of liver samples were used to evaluate the pathological changes and hepatocyte proliferation. RESULTS： In rats treated with retrorsine and CCl4, the liver displayed obvious megalocytosis, proliferation of mild bile duct, small hepatocyte-forming nodule, which were not found in liver samples from non-treated group. However, in mice treated with retrorsine combined with CCh, the liver displayed hepatocyte degeneration and necrosis in perivenous areas. There was no obvious difference between retrorsine-treated group and nontreated group. Ki-67 immunohistochemical analysis showed that in rats treated with retrorsine, the positive hepatocytes mainly found in small hepatocyte nodules, were obviously less than those in non-treated group. The mice treated with retrorsine showed that the number of Ki-67 positive hepatocytes was very high and more than that in non-treated group. CONCLUSION： Retrorsine has no effect on mouse hepatocyte proliferation.

Retrorsine Cooperates with Gut Microbiota to Promote Hepatic Sinusoidal Obstruction Syndrome by Disrupting the Gut Barrier

Background and Aims:Hepatic sinusoidal obstruction syndrome(HSOS)is a life-threatening syndrome,and a cause is exposure to pyrrolizidine alkaloid(PA)-containing products.It is well-established that retrorsine(RTS),a rep-resentative Pas,insults hepatic sinusoidal endothelial cells and ensues congestion of hepatic sinusoids.However,little known about the impact of Pas on gut microbiota and intesti-nal barrier and inflammation in HSOS.Methods:Mice were gavaged with or without nonabsorbable antibiotics(ABX),followed by a single dose of RTS.The gut microbiota was examined by 16S rDNA sequencing.Results:ABX pretreat-ment significantly reversed RTS-induced liver damage.RTS altered gut microbiota composition,increasing Gram-nega-tive bacteria and resulting in a sharp elevation of circulating lipopolysaccharides(LPS)in HSOS mice.Gut decontamina-tion with ABX alleviated RTS-induced intestine inflamma-tion,protected against disruption of the intestinal epithelial barrier and gut vascular barrier(GVB),and suppressed he-patic LPS-NF-κB pathway activation in RTS-induced HSOS.Importantly,the LPS level was positively correlated with MELD score in patients with HSOS.Elevated LPS in patients with HSOS confirmed that Gram-negative bacteria were in-volved in the pathogenesis of HSOS.Conclusions:RTS,a PA,cooperated with gut dysbiosis to cause intestinal inflam-mation and gut barrier compromise that increased transport of gut-derived LPS into the liver through the portal vein,which contributed to the pathology of HSOS.Modulating the gut microbiota,protecting the intestinal barrier,and sup-pressing intestinal inflammation with prebiotics or antibiot-ics might be a useful pharmacologic intervention in HSOS.