Cold‐inducible RNA‐binding protein regulates cyclin B1 against spermatogenesis arrest caused by heat stress

Abstract

Background Spermatogenesis arrest and spermatogenic cell apoptosis occur in the testes of heat‐stressed mice. Although heat stress‐induced spermatogenic cell apoptosis is due to the decreased expression of cold‐inducible RNA‐binding protein (CIRBP), it remains unclear whether spermatogenesis arrest is also affected by CIRBP. Additionally, the specific mechanism by which CIRBP regulates spermatogenic cell apoptosis or inhibits spermatogenesis remains to be elucidated. Objectives To investigate the mechanism by which CIRBP contributes to heat stress‐induced testicular spermatogenesis arrest. Materials and methods Target mRNAs downstream of CIRBP in testicular tissue of BALB/c mice, exposed or not to heat stress, were sequenced. Sequencing data were subjected to bioinformatics analysis to identify key mRNAs and pathways associated with heat stress‐induced spermatogenic damage. The link between CIRBP and its target mRNA Ccnb1 (cyclin B1) was verified by western blotting, flow cytometry, and RNA pulldown assays, and the ability of CIRBP to inhibit germ cell cycle arrest by regulating cyclin B1 expression was investigated in a mouse spermatocyte cell line (GC‐2spd). Results Changes in mRNA expression downstream of CIRBP were mainly associated with the cell cycle and RNA binding, transport and splicing. Cyclin B1 was found to regulate the G2/M transition during the first meiotic division of spermatogenic cells. Further, CIRBP was shown to bind directly to the 3′‐untranslated region of Ccnb1 mRNA and was associated with cyclin B1‐induced inhibition of spermatogenesis arrest. Discussion and conclusion In conclusion, our results provide strong evidence that CIRBP may exert its key function in heat stress‐induced testicular spermatogenic cell injury partly by regulating the expression of Ccnb1, the product of which inhibits spermatogenesis arrest.

Exposure to elevated temperature affects the expression of PIWI‐interacting RNAs and associated transcripts in mouse testes

“…21 These piRNAinvolved pathways were considered a germline-specific mechanism of gene silencing, which are crucial for protecting the genome integrity from transposable elements. 13,22 Multiple reports support the modulation of mRNAs and proteins in mouse testes exposed to heat stress, 3,6,23,24 whereas information is sparse regarding a differential expression of piRNAs following such situation. In this study, we investigated the expression profile and specific role of piRNA when adapted to testicular heat stress through piRNA sequencing in a mouse heat transcript overlap between GC-1 cells (or GC-2 cells) and the primary spermatocyte transcriptome, 28 which could also partially represent germ cells in vitro.…”

Specific expression of alternatively spliced genes in the turkey (Meleagris gallopavo) reproductive tract revealed their function in spermatogenesis and post-testicular sperm maturation

“…CIRBP is a cold-shock protein whose activation is increased in response to cold stress ( Nishiyama et al, 1997 ). In birds, CIRBP is expressed in the testis, and its transcription is decreased after heat stress in chickens ( Wang et al, 2013a ; Liu et al, 2022 ). The role of CIRBP in the heat-stress response of bird testes is still unknown.…”

“…The role of CIRBP in the heat-stress response of bird testes is still unknown. In mammals, CIRBP plays a key function in heat stress-induced testicular spermatogenic cell injury, acting as a modulator of cyclin B1 expression, which inhibits spermatogenesis arrest ( Xia et al, 2012 ; Liu et al, 2022 ). The turkey CIRBP gene was characterized by multiple splicing events, and 5 of them differentiated the testis and ductus deferens ( Supplementary Figure 1 F).…”