Loss of Slfn3 induces a sex-dependent repair vulnerability after 50% bowel resection.

Bowel resection accelerates enterocyte proliferation in the remaining gut with suboptimal absorptive and digestive capacity because of a proliferation-associated decrease in functional differentiation markers. We hypothesized that although schlafen 3 (Slfn3) is an important regulator of enterocytic differentiation, Slfn3 would have less impact on bowel resection adaptation, where accelerated proliferation takes priority over differentiation. We assessed proliferation, cell shedding, and enterocyte differentiation markers from resected and postoperative bowel of wild-type (WT) and Slfn3-knockout (Slfn3KO) mice. Villus length and crypt depth were increased in WT mice and were even longer in Slfn3KO mice. Mitotic marker, Phh3+, and the proliferation markers Lgr5, FoxL1, and platelet-derived growth factor-α (PDGFRα) were increased after resection in male WT, but this was blunted in male Slfn3KO mice. Cell-shedding regulators Villin1 and TNFα were downregulated in female mice and male WT mice only, whereas Gelsolin and EGFR increased expression in all mice. Slfn3 expression increased after resection in WT mice, whereas other Slfn family members 1, 2, 5, 8, and 9 had varied expressions that were affected also by sex difference and loss of Slfn3. Differentiation markers sucrase isomaltase, Dpp4, Glut2, and SGLT1 were all decreased, suggesting that enterocytic differentiation effort is incompatible with rapid proliferation shift in intestinal adaptation. Slfn3 absence potentiates villus length and crypt depth, suggesting that the differentiating stimulus of Slfn3 signaling may restrain mucosal mass increase through regulating Villin1, Gelsolin, EGFR, TNFα, and proliferation markers. Therefore, Slfn3 may be an important regulator not only of "normal" enterocytic differentiation but also in response to bowel resection.NEW & NOTEWORTHY The differentiating stimulus of Slfn3 signaling restrains an increase in mucosal mass after bowel resection, and there is a Slfn3-sex interaction regulating differentiation gene expression and intestinal adaptation. This current study highlights the combinatory effects of gender and Slfn3 genotype on the gene expression changes that contribute to the adaptation in intestinal cellular milleu (i.e. villus and crypt structure) which are utilized to compensate for the stress-healing response that the animals display in intestinal adaptation.

Loss of Schlafen3 influences the expression levels of Schlafen family members in ileum, thymus, and spleen tissue.

BACKGROUND: The Schlafen (Slfn) family proteins are important for regulation of cell growth, cell differentiation and cell cycle progression. We sought to distinguish Slfn family expression in Slfn3 knockout (KO) mice after RNA sequencing analysis of Slfn3KO vs. wildtype (WT) mice revealed varying expressions of Slfn family in ileal mucosa. METHODS: Quantitative PCR analysis of Slfn members was evaluated in ileal mucosa, thymus and spleen tissue since Slfn family members have roles in differentiating intestinal and immune cells. RESULTS: Ileal mucosa of Slfn3KO mice displayed a decrease in Slfn3, 4, 8 and 9 while Slfn1 and 5 increased in mRNA expression vs. WT mice. Thymic tissue had a Slfn9 increase and a Slfn4 decrease while splenic tissue had a Slfn8 and Slfn9 increase in Slfn3KO mice vs. WT mice. These differential expressions of Slfn members could indicate a feedback regulatory mechanism within the Slfn family. Indeed, MATCH™ tool from geneXplain predicted that all Slfn members have regions in their promoters for the Kruppel-like factor-6 transcription factor. In addition, NFAT related factors, ING4, ZNF333 and KLF4 are also predicted to bind in up to 6 of the 8 Slfn promoters. This study further describes a possible autoregulatory mechanism amongst the Slfn family members which could be important in how they regulate the differentiation of various cell types.