Hepatic LGR4 aggravates cholestasis-induced liver injury in mice.

Current therapy for hepatic injury induced by the accumulation of bile acids is limited. Leucine-rich repeat G protein-coupled receptor 4 (LGR4), also known as GPR48, is critical for cytoprotection and cell proliferation. Here, we reported a novel function for the LGR4 in cholestatic liver injury. In the bile duct ligation (BDL)-induced liver injury model, hepatic LGR4 expression was significantly downregulated. Deficiency of LGR4 in hepatocytes (Lgr4LKO) notably decreased BDL-induced liver injury measured by hepatic necrosis, fibrosis, and circulating liver enzymes and total bilirubin. Levels of total bile acids in plasma and liver were markedly reduced in these mice. However, deficiency of LGR4 in macrophages (Lyz2-Lgr4MKO) demonstrated no significant effect on liver injury induced by BDL. Deficiency of LGR4 in hepatocytes significantly attenuated S1PR2 and the phosphorylation of protein kinase B (AKT) induced by BDL. Recombinant Rspo1 and Rspo3 potentiated the taurocholic acid (TCA)-induced upregulation in S1PR2 and phosphorylation of AKT in hepatocytes. Inhibition of S1PR2-AKT signaling by specific AKT or S1PR2 inhibitors blocked the increase of bile acid secretion induced by Rspo1/3 in hepatocytes. Our studies indicate that the R-spondins (Rspos)-LGR4 signaling in hepatocytes aggravates the cholestatic liver injury by potentiating the production of bile acids in a S1PR2-AKT-dependent manner.NEW & NOTEWORTHY Deficiency of LGR4 in hepatocytes alleviates BDL-induced liver injury. LGR4 in macrophages demonstrates no effect on BDL-induced liver injury. Rspos-LGR4 increases bile acid synthesis and transport via potentiating S1PR2-AKT signaling in hepatocytes.

[A comparative study of cerebellar development between appropriate-for-gestational age infants and small-for-gestational-age infants].

OBJECTIVE: To investigate whether there is a difference in cerebellar development between appropriate -for-gestational-age (AGA) infants and small-for-gestational-age (SGA) infants. METHODS: A total of 165 AGA infants and 105 SGA infants, with a gestational age of 26-40+6 weeks, were enrolled in this study. Within 24-48 hours after birth, ultrasound examination was performed to measure the transverse diameter of the cerebellum, the height of the vermis, the area of the vermis, the perimeter of the vermis, and the area and perimeter of the cerebellum on transverse section. A Pearson correlation analysis was used to investigate the correlation between cerebellar measurements and gestational age. RESULTS: In both AGA and SGA infants, all cerebellar measurements were positively correlated with gestational age (r=0.50-0.81, P<0.05). In AGA and SGA infants, there were no significant differences in the measurements between the 25-27+6 weeks, 28-30+6 weeks, and 31-33+6 weeks of gestational age subgroups (P>0.05), while in the 34-36+6 weeks and 37-40+6 weeks subgroups, the SGA infants had significantly lower measurements than the AGA infants (P<0.05). CONCLUSIONS: The SGA infants with a gestational age of <34 weeks have intrauterine cerebellar development similar to AGA infants, but those with a gestational age of ≥34 weeks have poorer intrauterine cerebellar development than AGA infants.