Activation-induced cytidine deaminase is a possible regulator of cross-talk between oocytes and granulosa cells through GDF-9 and SCF feedback system

Abstract

Activation-induced cytidine deaminase (AID, Aicda) is a master gene regulating class switching of immunoglobulin genes. In this study, we investigated the significance of AID expression in the ovary. Immunohistological study and RT-PCR showed that AID was expressed in murine granulosa cells and oocytes. However, using the Aicda-Cre/Rosa-tdRFP reporter mouse, its transcriptional history in oocytes was not detected, suggesting that AID mRNA in oocytes has an exogenous origin. Microarray and qPCR validation revealed that mRNA expressions of growth differentiation factor-9 (GDF-9) in oocytes and stem cell factor (SCF) in granulosa cells were significantly decreased in AID-knockout mice compared with wild-type mice. A 6-h incubation of primary granuloma cells markedly reduced AID expression, whereas it was maintained by recombinant GDF-9. In contrast, SCF expression was induced by more than threefold, whereas GDF-9 completely inhibited its increase. In the presence of GDF-9, knockdown of AID by siRNA further decreased SCF expression. However, in AID-suppressed granulosa cells and ovarian tissues of AID-knockout mice, there were no differences in the methylation of SCF and GDF-9. These findings suggest that AID is a novel candidate that regulates cross-talk between oocytes and granulosa cells through a GDF-9 and SCF feedback system, probably in a methylation-independent manner.

Uterine Deletion of Bmal1 Impairs Placental Vascularization and Induces Intrauterine Fetal Death in Mice

“…In a total of 20,983 genes, up-regulated genes were defined as those with both up-regulated in ZT0 and ZT12 (fold-change > 1; 6147 genes) and were selected by multiplying the absolute value of each WAD (>0.02; 597 genes), whereas down-regulated genes were those with both down-regulated (fold-change < 1; 5169 genes) and were selected (>0.02; 515 genes) as described previously [ 18 ]. Gene ontology biological process term enrichment analyses of the identified up- and down-regulated genes detected by WAD were performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) with the threshold at a p -value < 0.05, and the top 11 groups are presented [ 18 ] ( Figure 4 A). Since the gene ontology terms of immune responses including NK cell activation were dominantly detected in the down-regulated group, we focused on the uterine NK (uNK) cells.…”

“…After removing contaminating genomic DNA with TURBO DNA-free Kit (Thermo Fisher, Waltham, MA, USA), one µg RNA was reverse-transcribed with Superscript II and oligo(dT) primer to prepare cDNA (Thermo Fisher, Waltham, MA, USA). PCR was performed as previously described [ 18 , 46 ]. The primer sequences for PCR are forward primer (5′-aaagaggcgtcgggacaaaa-3′) and reverse primer (5′-ccatctgctgccctgagaat-3′) for Bmal1 , and forward primer (5′-ctctcgctttctggagggtg-3′) and reverse primer (5′-tcagtctccacagacaatgcc-3′) for Rplp0 as an internal control.…”

“…To investigate the key genes related to uterine functional changes in cKO mice, we performed microarray analysis using uterine tissues of WT and cKO mice. In a total of 20,983 genes, up-regulated genes were defined as those with both up-regulated in ZT0 and ZT12 (fold-change > 1; 6147 genes) and were selected by multiplying the absolute value of each WAD (>0.02; 597 genes), whereas down-regulated genes were those with both down-regulated (fold-change < 1; 5169 genes) and were selected (>0.02; 515 genes) as described previously [18]. Gene ontology biological process term enrichment analyses of the identified up-and down-regulated genes detected by WAD were performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) with the threshold at a p-value < 0.05, and the top 11 groups are presented [18] (Figure 4A).…”