目的:人类睾丸衰老功能下降的分子背景是什么?
结论:本研究提供了一个全面的年轻人和老年人睾丸的单细胞转录组学图谱,并提供了对人类睾丸衰老的分子机制和潜在目标的见解。
背景:已知睾丸老化会导致男性年龄相关的生育能力下降和性腺功能减退。睾丸细胞功能失调被认为是睾丸衰老的关键因素。
方法:从三个年轻个体和三个老年个体中收集人睾丸活检以进行单细胞RNA测序(scRNA-seq)。关键结果在包含来自10个年轻供体和10个年老供体的人睾丸样品的较大队列中得到验证。
方法:scRNA-seq用于鉴定衰老过程中人类睾丸细胞的基因表达特征。通过基因集富集分析分析了精原干细胞(SSCs)和睾丸间质细胞(LCs)中基因表达的衰老相关变化,并通过免疫荧光和功能测定进行了验证。使用CellChat进行细胞-细胞通讯分析。
结果:调查了年轻人和老年人睾丸的单细胞转录组景观,揭示了种系和体细胞生态位细胞的年龄相关变化。对生殖细胞基因表达动力学的深入评估表明,碱基切除修复途径的破坏是旧SSCs的突出特征,提示SSC中DNA修复缺陷可能是随着年龄增长从头生殖系突变增加的潜在驱动因素。对衰老相关转录变化的进一步分析表明,应激相关变化和细胞因子途径在旧体细胞中积累。鉴定了老年LC中与年龄相关的氧化还原稳态损害,抗氧化剂的药物治疗减轻了LC的这种细胞功能障碍并促进了睾丸激素的产生。最后,我们的研究结果表明,在睾丸衰老过程中,多效蛋白信号的减少是导致精子发生受损的一个因素。
方法:本文报道的scRNA-seq测序和处理数据保存在基因组序列存档(https://ngdc。cncb.AC.cn/),在登录号HRA002349下。
结论:由于收集人体睾丸组织的困难,样本量有限。未来需要进一步深入的功能和机理研究。
结论:这些发现全面了解了人类睾丸衰老的细胞类型特异性机制,并提出了潜在的治疗靶点,这些靶点可用于解决与年龄相关的男性生育能力下降和性腺功能减退。
背景:这项工作得到了国家重点研究发展计划(2022YFA1104100)的支持,国家自然科学基金(32130046,82171564,82101669,82371611,82371609,82301796),广东省自然科学基金,中国(2022A1515010371),国家卫生计生委医学科技发展研究中心重大项目,中国(HDSL202001000),NHC男性生殖与遗传学重点实验室开放项目(KF202001),广东省区域联合基金-青年基金项目(2021A1515110921,2022A1515111201),和中国博士后科学基金(2021M703736)。作者声明没有利益冲突。
OBJECTIVE: What is the molecular landscape underlying the functional decline of human testicular ageing?
CONCLUSIONS: The present study provides a comprehensive single-cell transcriptomic atlas of testes from young and old humans and offers insights into the molecular mechanisms and potential targets for human testicular ageing.
BACKGROUND: Testicular ageing is known to cause male age-related fertility decline and hypogonadism. Dysfunction of testicular cells has been considered as a key factor for testicular ageing.
METHODS: Human testicular biopsies were collected from three young individuals and three old individuals to perform single-cell RNA sequencing (scRNA-seq). The key results were validated in a larger cohort containing human testicular samples from 10 young donors and 10 old donors.
METHODS: scRNA-seq was used to identify gene expression signatures for human testicular cells during ageing. Ageing-associated changes of gene expression in spermatogonial stem cells (SSCs) and Leydig cells (LCs) were analysed by gene set enrichment analysis and validated by immunofluorescent and functional assays. Cell-cell communication analysis was performed using CellChat.
RESULTS: The single-cell transcriptomic landscape of testes from young and old men was surveyed, revealing age-related changes in germline and somatic niche cells. In-depth evaluation of the gene expression dynamics in germ cells revealed that the disruption of the base-excision repair pathway is a prominent characteristic of old SSCs, suggesting that defective DNA repair in SSCs may serve as a potential driver for increased de novo germline mutations with age. Further analysis of ageing-associated transcriptional changes demonstrated that stress-related changes and cytokine pathways accumulate in old somatic cells. Age-related impairment of redox homeostasis in old LCs was identified and pharmacological treatment with antioxidants alleviated this cellular dysfunction of LCs and promoted testosterone production. Lastly, our results revealed that decreased
pleiotrophin signalling was a contributing factor for impaired spermatogenesis in testicular ageing.
METHODS: The scRNA-seq sequencing and processed data reported in this paper were deposited at the Genome Sequence Archive (https://ngdc.cncb.ac.cn/), under the accession number HRA002349.
CONCLUSIONS: Owing to the difficulty in collecting human testis tissue, the sample size was limited. Further in-depth functional and mechanistic studies are warranted in future.
CONCLUSIONS: These findings provide a comprehensive understanding of the cell type-specific mechanisms underlying human testicular ageing at a single-cell resolution, and suggest potential therapeutic targets that may be leveraged to address age-related male fertility decline and hypogonadism.
BACKGROUND: This work was supported by the National Key Research and Development Program of China (2022YFA1104100), the National Natural Science Foundation of China (32130046, 82171564, 82101669, 82371611, 82371609, 82301796), the Natural Science Foundation of Guangdong Province, China (2022A1515010371), the Major Project of Medical Science and Technology Development Research Center of National Health Planning Commission, China (HDSL202001000), the Open Project of NHC Key Laboratory of Male Reproduction and Genetics (KF202001), the Guangdong Province Regional Joint Fund-Youth Fund Project (2021A1515110921, 2022A1515111201), and the China Postdoctoral Science Foundation (2021M703736). The authors declare no conflict of interest.