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

Abstract

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.

Vil-Cre specific Schlafen 3 knockout mice exhibit sex-specific differences in intestinal differentiation markers and Schlafen family members expression levels

“…Previously, we demonstrated that expression of Slfn family members are affected by the loss of Slfn3 in the ileum of pan-Slfn3KO mice [ 18 ]. The loss of Slfn3 in the intestinal epithelial cells of VC-Slfn3KO mice also affected the expression of Slfn family members in the duodenal, jejunal, and ileal mucosa.…”

“…We also evaluated the expression of Slfn family members in the spleen. We did not expect to see a change in Slfn family expression in these VC-Slfn3KO mice due to the Vil-Cre being epithelial-specific for knocking out Slfn3, as we had seen in the pan-Slfn3KO mice [ 18 ]. Slfn3 RNA expression was present in all groups ( S3 Fig ).…”

“…Previous evaluation of Slfn family member RNA expression in the pan-Slfn3KO mice displayed an increase in Slfn1 and Slfn5 and a decrease in Slfn4, Slfn8, and Slfn9 in the ileal mucosa and was not affected by sex [ 18 ]. In this study, we extended our assessment to all intestinal regions and found a sex-dependent increase for Slfn2 and Slfn8 in the duodenal and jejunal regions of the female VC-Slfn3KO vs. Ctrl mice.…”

“…There is a direct correlation between the expression of Slfn3 and the expression of epithelial differentiation markers sucrase isomaltase (SI), villin1 (Vil1), dipeptidyl peptidase 4 (Dpp4), glucose transporter 2 (Glut2), and sodium glucose transporter 1 (SGLT1), which is dependent on the P-loop region in the N-terminus of Slfn3 [ 12 , 15 – 17 ]. Previous work utilizing a pan-Slfn3 knockout (Slfn3KO) mouse demonstrated that Slfn3 affects the mRNA expression levels of Slfn family members in the intestinal mucosa, thymus, and spleen [ 18 ]. Additionally, the global loss of Slfn3 results in sex-dependent disturbances in metabolic pathways, genes related to adipogenesis and ketogenesis, and intestinal differentiation markers [ 16 ].…”

Schlafens: Emerging Proteins in Cancer Cell Biology

“…The adaptation of A549 cells to the continuous stable loss of SLFN5 or off-target effects of the transient knockdown could affect other Schlafens. Manipulating levels of one Schlafen protein may affect others by feedback loops that await elucidation [ 89 ]. Therefore, it would be interesting and potentially explanatory to examine the expression of other endogenous Schlafen proteins in the experiments described by Guo et al [ 76 ] and Wan et al [ 77 ].…”