CHD4 acts as a critical regulator in the survival of spermatogonial stem cells in mice [RNA-Seq]

Male spermatogenesis is sustained by homeostatic balance between the self-renewal and differentiation of spermatogonial stem cells (SSCs), which is dependent on the strict regulation of transcriptional factor and chromatin modulator gene expression. Chromodomain helicase DNA-binding protein 4 (CHD4) is highly expressed in SSCs but roles in mouse spermatogenesis are unexplored. Here, we report that the germ-cell-specific deletion of Chd4 resulted in complete infertility in male mice, with rapid loss of SSCs and excessive germ cell apoptosis. Chd4-knockdown in cultured SSCs also promoted the expression of apoptosis-related genes and thereby activated the tumor necrosis factor signaling pathway. Mechanistically, CHD4 occupies the genomic regulatory region of key apoptosis-related genes including Jun and Nfkb1. Together, our findings reveal the determinant role of CHD4 in SSCs survival in vivo, which will offer insight into the pathogenesis of male sterility and potential novel therapeutic targets. Overall design: We sequenced the SSCs mRNA from both control and Chd4-KD and three biological replicates were generated per condition.

雄性精子发生的维持依赖于精原干细胞（spermatogonial stem cells, SSCs）自我更新与分化之间的稳态平衡，而该平衡严格依赖于转录因子与染色质调控因子的基因表达调控。染色质域解旋酶DNA结合蛋白4（Chromodomain helicase DNA-binding protein 4, CHD4）在精原干细胞中高表达，但其在小鼠精子发生中的功能尚未被阐明。本研究发现，生殖细胞特异性敲除Chd4会导致雄性小鼠完全不育，伴随精原干细胞的快速丢失与生殖细胞的过度凋亡。在体外培养的精原干细胞中敲低Chd4同样可促进凋亡相关基因的表达，进而激活肿瘤坏死因子信号通路。机制层面研究表明，CHD4可结合包括Jun与Nfkb1在内的关键凋亡相关基因的基因组调控区域。综上，本研究揭示了CHD4在体内精原干细胞存活中的决定性作用，该发现可为男性不育的发病机制研究提供新见解，并为潜在的新型治疗靶点提供思路。实验设计概述：我们对对照组与Chd4敲低（Chd4-KD）组的精原干细胞mRNA进行了测序，每组设置3次生物学重复。