Mao Jing-Jing, Dai Xiao-Yu, Liu Yun-Zi, Ren Li-Jun, Zhang Ji-Qian-Zhu, Yan Lang, Li Jin-Feng, Tian Yi-Jun, Zhu Jiang-Bo, Chen Ji-Kuai
Department of Health Toxicology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China; Key Laboratory of Biosafety Defense (Naval Medical University), Ministry of Education, Shanghai 200433, China.
Department of Health Toxicology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
Reprod Toxicol. 2024 Dec;130:108701. doi: 10.1016/j.reprotox.2024.108701. Epub 2024 Aug 30.
DNAJA1 is a member of type I DnaJ proteins, which is essential for spermatogenesis and male fertility. However, its expression pattern in the testes and its impact on spermatogenesis remains unclear. Our study aimed to elucidate the mechanism of action of DNAJA1. We employed DNAJA1 knockout mice in this study. Western blotting and immunofluorescence analysis were conducted to determine the protein abundance of DNAJA1 in testes at various developmental stages. Our results revealed that DNAJA1 is predominantly expressed in the testes, and its knockout leads to complete infertility in male mice. We observed that DNAJA1 protein levels increased on postnatal days 14, 21, and 28, peaking on postnatal day 35 in mice. Immunofluorescence staining indicated that DNAJA1 expression varies across different stages of the spermatogenesis cycle. Additionally, DNAJA1 was absent in epididymal sperm. In early- and mid-stage tubules, DNAJA1 protein distribution was co-localized with residual bodies in elongating spermatids. Furthermore, we found that DNAJA1 knockout significantly reduced protein polyubiquitination in the testis. Analysis of the GEO database showed that DNAJA1 levels were significantly decreased in semen samples from subjects with teratozoospermia, asthenozoospermia, and impaired spermatogenesis. Our findings suggest that DNAJA1 is an essential protein for spermatogenesis, and its deletion reduces protein polyubiquitination in the testis, ultimately resulting in infertility and spermatogenesis defects.
DNAJA1是I型DnaJ蛋白家族的成员，对精子发生和男性生育至关重要。然而，其在睾丸中的表达模式及其对精子发生的影响仍不清楚。我们的研究旨在阐明DNAJA1的作用机制。本研究中我们使用了DNAJA1基因敲除小鼠。通过蛋白质免疫印迹法和免疫荧光分析来确定不同发育阶段睾丸中DNAJA1的蛋白丰度。我们的结果显示，DNAJA1主要在睾丸中表达，其敲除导致雄性小鼠完全不育。我们观察到，小鼠出生后第14、21和28天DNAJA1蛋白水平升高，在出生后第35天达到峰值。免疫荧光染色表明，DNAJA1的表达在精子发生周期的不同阶段有所变化。此外，附睾精子中不存在DNAJA1。在早期和中期的曲细精管中，DNAJA1蛋白分布与延长型精子细胞中的残余体共定位。此外，我们发现DNAJA1敲除显著降低了睾丸中的蛋白质多聚泛素化。对GEO数据库的分析表明，在患有畸形精子症、弱精子症和精子发生受损的受试者的精液样本中，DNAJA1水平显著降低。我们的研究结果表明，DNAJA1是精子发生所必需的蛋白质，其缺失会降低睾丸中的蛋白质多聚泛素化，最终导致不育和精子发生缺陷。
