Male specific conserved LncRNA TSCL1 regulated target mRNA translation by interaction with PIWIL1 [lncRNA-seq]

Long non-coding RNAs are known to play crucial roles in various physiological processes in mammals, yet their functions in spermatogenesis remain largely underexplored. Here, we have identified a distinct category of conserved haploid spermatids-associated long non-coding RNAs (cHS-LncRNAs) characterized by their sequence-based conservation, specific expression in the testis, and elevated expression levels in haploid spermatids. Among these, we found that the testis specific conserved LncRNA 1 (Tscl1) exhibits the highest expression in round spermatids. Deletion of Tscl1 in mice exhibits reduced sperm motility, disordered mitochondrial sheath structure, abnormal fatty acid metabolism, and results in male infertility. Mechanistically, Tscl1 directly interacts with PIWIL1 and HuR via its 5 end stem-loop structure and multiple AU-rich elements, respectively. This binding pattern promotes the formation of the PIWIL1/eIF3f/HuR/eIF4G3 supercomplex, regulating the translation efficiency of fatty acid metabolism-associated mRNAs within the chromatoid body. Furthermore, the region where TSCL1 interacts with PIWIL1 is significantly enriched with TSCL1 variants identified in patients with non-obstructive azoospermia (NOA) compared to those in the fertile controls (OR=5.992, P=0.020, NCase=1,338, NControl=2,664). Taken together, our findings elucidate the critical role of Tscl1 in regulating the translation efficiency of target mRNAs through its collaboration with PIWIL1 and HuR during spermiogenesis. lncRNA-seq profiling of PAC, RS, and ES cells isolated from mouse testes, with three biological replicates for each group长链非编码RNA（long non-coding RNAs，lncRNAs）已被证实可在哺乳动物的多种生理过程中发挥关键作用，然而其在精子发生过程中的功能仍未得到充分探究。本研究鉴定出一类独特的保守单倍体精子细胞相关长链非编码RNA（conserved haploid spermatids-associated long non-coding RNAs，cHS-LncRNAs），其特征为序列保守、睾丸特异性表达以及在单倍体精子细胞中表达量升高。其中，睾丸特异性保守长链非编码RNA 1（testis specific conserved LncRNA 1，Tscl1）在圆形精子细胞中表达量最高。在小鼠中敲除Tscl1会导致精子活力下降、线粒体鞘结构紊乱、脂肪酸代谢异常，并引发雄性不育。机制研究显示，Tscl1分别通过其5'端茎环结构与多个AU富集元件，直接与PIWIL1和HuR相互作用。这种结合模式可促进PIWIL1/eIF3f/HuR/eIF4G3超复合物的形成，进而调控拟染色体体（chromatoid body）内脂肪酸代谢相关mRNA的翻译效率。此外，与生育对照人群相比，在非梗阻性无精子症（non-obstructive azoospermia，NOA）患者中鉴定到的TSCL1变异显著富集于TSCL1与PIWIL1相互作用的区域（优势比OR=5.992，P=0.020，病例组样本量NCase=1,338，对照组样本量NControl=2,664）。综上，本研究阐明了Tscl1在精子形成过程中，通过与PIWIL1和HuR协同作用调控靶mRNA翻译效率的关键作用。对从小鼠睾丸中分离的PAC、RS与ES细胞开展lncRNA测序（lncRNA-seq）谱分析，每组设置3次生物学重复。