Serine and Arginine-Rich Splicing Factor 3 Promotes the Activation of Quiescent Mouse Neural Stem Cells.

The quiescence and activation of adult stem cells are regulated by many kinds of molecular mechanisms, and RNA alternative splicing participates in regulating many cellular processes. However, the relationship between stem cell quiescence and activation regulation and gene alternative splicing has yet to be studied. In this study, we aimed to elucidate the regulation of stem cell quiescence and activation by RNA alternative splicing. The upregulated genes in activated mouse neural stem cells (NSCs), muscle stem cells, and hematopoietic stem cells were collected for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The genes from three tissue stem cells underwent Venn analysis. The mouse NSCs were used for quiescence and reactivation induction. The immunostaining of cell-specific markers was performed to identify cell properties. The reverse transcription-polymerase chain reaction and western blotting were used to detect the gene expression and protein expression, respectively. We found that the upregulated genes in activated stem cells from three tissues were all enriched in RNA splicing-related biological processes; the upregulated RNA splicing-related genes in activated stem cells displayed tissue differences; mouse NSCs were successfully induced into quiescence and reactivation in vitro without losing differentiation potential; serine and arginine-rich splicing factor 3 (Srsf3) was highly expressed in the activated mouse NSCs, and the overexpression of SRSF3 protein promoted the activation of quiescent mouse NSCs and increased the neural cell production. Our data indicate that the alternative splicing change may underline the transition of quiescence and activation of stem cells. The manipulation of the splicing factor may benefit tissue repair by promoting the activation of quiescent stem cells.

Curative effect and technical key points of laparoscopic surgery for choledochal cysts in children.

Objective: The purpose of this study was to investigate the curative effect of and experience with laparoscopic surgery for congenital choledochal cysts in children. Methods: This is a retrospective analysis of 33 children diagnosed with congenital choledochal cyst in the pediatric surgery department of the Affiliated Hospital of Southwest Medical University between January 2019 and December 2021. The cohort included 8 males and 25 females aged 0.25-13.7 years (median age, 3.2 years), including 21 cases of type I and 12 cases of type IV choledochal cyst (Todani classification). Laparoscopic choledochal cyst resection and hepaticojejunostomy with Roux-en-Y anastomosis were performed in all the patients. Results: Laparoscopy without transit opening was successfully performed in the 33 cases. The duration of the procedure was 235-460 min (mean ± SD, 316 ± 61 min), and intraoperative blood loss volume was 15-40 ml (23 ± 7.6 ml). Postoperative hospital stay was 7-14 days (9 ± 1.8 days). Postoperative biliary fistula and pancreatitis occurred in two cases each, and all four patients were successfully treated with conservative treatment. No anastomotic stenosis, delayed bleeding, cholangitis, intestinal obstruction, or other complications occurred. All the children were followed up for 2-36 months (median period, 17.2 months). The clinical symptoms disappeared, and no obvious hepatic dysfunction was found on abdominal color ultrasound and liver function examination. Conclusion: Laparoscopic surgery for congenital choledochal cyst in children is safe and effective, as it is a minimally invasive surgery that is associated with a low degree of trauma and bleeding, rapid postoperative recovery, and satisfactory aesthetic appearance.

Downregulation of Hes1 expression in experimental biliary atresia and its effects on bile duct structure.

AIM: To analyze the expression and function of the Notch signaling target gene Hes1 in a rhesus rotavirus-induced mouse biliary atresia model. METHODS: The morphologies of biliary epithelial cells in biliary atresia patients and in a mouse model were examined by immunohistochemical staining. Then, the differential expression of Notch signaling pathway-related molecules was investigated. Further, the effects of the siRNA-mediated inhibition of Hes1 expression were examined using a biliary epithelial cell 3D culture system. RESULTS: Both immature (EpCAM+) and mature (CK19+) biliary epithelial cells were detected in the livers of biliary atresia patients without a ductile structure and in the mouse model with a distorted bile duct structure. The hepatic expression of transcripts for most Notch signaling molecules were significantly reduced on day 7 but recovered to normal levels by day 14, except for the target molecule Hes1, which still exhibited lower mRNA and protein levels. Expression of the Hes1 transcriptional co-regulator, RBP-Jκ was also reduced. A 3D gel culture system promoted the maturation of immature biliary epithelial cells, with increased expression of CK19+ cells and the formation of a duct-like structure. The administration of Hes1 siRNA blocked this process. As a result, the cells remained in an immature state, and no duct-like structure was observed. CONCLUSION: Our data indicated that Hes1 might contribute to the maturation and the cellular structure organization of biliary epithelial cells, which provides new insight into understanding the pathology of biliary atresia.

The Association between GWAS-identified BARD1 Gene SNPs and Neuroblastoma Susceptibility in a Southern Chinese Population.

A previous genome-wide association study (GWAS) has found that some common variations in the BARD1 gene were associated with neuroblastoma susceptibility especially for high-risk subjects, and the associations have been validated in Caucasians and African-Americans. However, the associations between BARD1 gene polymorphisms and neuroblastoma susceptibility have not been studied among Asians, not to mention Chinese subjects. In the present study, we investigated the association of three BARD1 polymorphisms (rs7585356 G>A, rs6435862 T>G and rs3768716 A>G) with neuroblastoma susceptibility in 201 neuroblastoma patients and 531 controls using TaqMan methodology. Overall, none of these polymorphisms was significantly associated with neuroblastoma susceptibility. However, stratified analysis showed a more profound association between neuroblastoma risk and rs6435862 TG/GG variant genotypes among older children (adjusted OR=1.55, 95% CI=1.04-2.31), and children with adrenal gland-originated disease (adjusted OR=2.94, 95% CI=1.40-6.18), or with ISSN clinical stages III+IV disease (adjusted OR=1.75, 95% CI=1.09-2.84). Similar results were observed for the variant genotypes of rs3768716 A>G polymorphism among these three subgroups. Our results suggest that the BARD1 rs6435862 T>G and rs3768716 A>G polymorphisms may contribute to increased susceptibility to neuroblastoma, especially for the subjects at age ≥12 months, with adrenal gland-originated or with late clinical stage neuroblastoma. These findings need further validation by prospective studies with larger sample size with subjects enrolled from multicenter, involving different ethnicities.