Garcia-Fabiani Maria B, Montanaro Mauro A, Stringa Pablo, Lacunza Ezequiel, Cattaneo Elizabeth R, Santana Marianela, Pellon-Maison Magali, Gonzalez-Baro Maria R
Instituto de Investigaciones Bioquímicas de La Plata 'Rodolfo R. Brenner', Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata 1900, Argentina.
Laboratorio de Trasplante de Órganos, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata 1900, Argentina.
Biochem J. 2017 Aug 30;474(18):3093-3107. doi: 10.1042/BCJ20161018.
Glycerol-3-phosphate acyltransferases (GPATs) catalyze the first and rate-limiting step in the glycerolipid synthesis. The GPAT2 isoform differs from the other isoforms because its expression is restricted to male germ cells and cancer cells. It has been recently reported that GPAT2 expression in mouse testis fluctuates during sexual maturation and that it is regulated by epigenetic mechanisms in combination with vitamin A derivatives. Despite progress made in this field, information about GPAT2 role in the developing male germ cells remains unclear. The aim of the present study was to confirm the hypothesis that GPAT2 is required for the normal physiology of testes and male germ cell maturation. The gene was silenced by inoculating lentiviral particles carrying the sequence of a short-hairpin RNA targeting mRNA into mouse testis. Histological and gene expression analysis showed impaired spermatogenesis and arrest at the pachytene stage. Defects in reproductive fitness were also observed, and the analysis of apoptosis-related gene expression demonstrated the activation of apoptosis in -silenced germ cells. These findings indicate that GPAT2 protein is necessary for the normal development of male gonocytes, and that its absence triggers apoptotic mechanisms, thereby decreasing the number of dividing germ cells.
甘油-3-磷酸酰基转移酶(GPATs)催化甘油脂质合成的第一步且是限速步骤。GPAT2同工型与其他同工型不同,因为其表达仅限于雄性生殖细胞和癌细胞。最近有报道称,小鼠睾丸中GPAT2的表达在性成熟过程中会波动,并且它受表观遗传机制与维生素A衍生物共同调控。尽管该领域已取得进展,但关于GPAT2在发育中的雄性生殖细胞中的作用仍不清楚。本研究的目的是证实GPAT2是睾丸正常生理功能和雄性生殖细胞成熟所必需的这一假设。通过将携带靶向mRNA的短发夹RNA序列的慢病毒颗粒接种到小鼠睾丸中,使该基因沉默。组织学和基因表达分析显示精子发生受损并停滞在粗线期。还观察到生殖适应性缺陷,并且对凋亡相关基因表达的分析表明沉默基因的生殖细胞中凋亡被激活。这些发现表明,GPAT2蛋白是雄性生殖母细胞正常发育所必需的,其缺失会触发凋亡机制,从而减少分裂生殖细胞的数量。