目的:肌动蛋白相关蛋白T1(ACTRT1)缺乏可能是男性不育的潜在致病因素吗?
结论:X染色体110kb微缺失,仅包括ACTRT1基因,在两名精子显示顶体超微结构缺陷和受精失败的中国男性中,被确定为不育的原因。
背景:肌动蛋白相关蛋白(例如ACTRT1,ACTRT2,ACTL7A,和ACTL9)相互作用,在精子的顶体下区形成多聚体复合物,这对顶体-核连接至关重要。Actrt1敲除(KO)小鼠由于畸形的精子头,顶体分离和部分受精失败而严重不育。目前尚无关于ACTRT1缺失与人类男性不育之间关联的报道。
方法:我们于2019年8月至2023年8月在一家大型三级医院招募了120名精子头部畸形的不育男性。从受影响的个体中提取的基因组DNA进行了全外显子组测序(WES),并进行了计算机模拟分析以鉴定遗传变异。形态学分析,功能测定,和ART分别于2022年和2023年进行。
方法:通过WES鉴定ACTRT1缺陷,并通过全基因组测序证实,PCR,和定量PCR。收集所有家族成员的基因组DNA以定义遗传模式。进行巴氏染色和电子显微镜检查以揭示精子形态变化。采用免疫印迹和免疫染色方法探讨ACTRT1缺乏的病理机制。ICSI结合人工卵母细胞激活(AOA)用于一个先证者。
结果:我们在两名不育男性中发现了ACTRT1的全基因缺失变体,从他们的母亲那里继承下来,分别。先证者由于顶体脱离而表现出精子头变形,这与我们之前对Actrt1-KO小鼠的观察结果一致。在先证者的精子样品中观察到ACTL7A和磷脂酶Cζ的表达降低和异位分布。ICSI结合AOA有效地解决了Actrt1-KO小鼠和两个先证者之一的受精问题。
结论:需要更多病例来进一步确认ACTRT1变异对男性不育的遗传贡献。
结论:我们的结果揭示了此处描述的ACTRT1缺失与由于顶体脱离和受精失败导致的人类男性不育之间的基因-疾病关系。本报告还描述了以ICSI-AOA为先证者的ART良好生殖结果。
背景:这项工作得到了重庆市医学科研项目(重庆市卫生健康委员会和科技局联合项目,2023MSXM008和2023MSXM054)。没有竞争的利益可以宣布。
背景:不适用。
OBJECTIVE: Could actin-related protein T1 (ACTRT1) deficiency be a potential pathogenic factor of human male infertility?
CONCLUSIONS: A 110-kb microdeletion of the X chromosome, only including the ACTRT1 gene, was identified as responsible for infertility in two Chinese males with sperm showing acrosomal ultrastructural defects and fertilization failure.
BACKGROUND: The actin-related proteins (e.g. ACTRT1, ACTRT2, ACTL7A, and ACTL9) interact with each other to form a multimeric complex in the subacrosomal region of spermatids, which is crucial for the acrosome-nucleus junction. Actrt1-knockout (KO) mice are severely subfertile owing to malformed sperm heads with detached acrosomes and partial fertilization failure. There are currently no reports on the association between ACTRT1 deletion and male infertility in humans.
METHODS: We recruited a cohort of 120 infertile males with sperm head deformations at a large tertiary hospital from August 2019 to August 2023. Genomic DNA extracted from the affected individuals underwent whole exome sequencing (WES), and in silico analyses were performed to identify genetic variants. Morphological analysis, functional assays, and ART were performed in 2022 and 2023.
METHODS: The ACTRT1 deficiency was identified by WES and confirmed by whole genome sequencing, PCR, and quantitative PCR. Genomic DNA of all family members was collected to define the hereditary mode. Papanicolaou staining and electronic microscopy were performed to reveal sperm morphological changes. Western blotting and immunostaining were performed to explore the pathological mechanism of ACTRT1 deficiency. ICSI combined with artificial oocyte activation (AOA) was applied for one proband.
RESULTS: We identified a whole-gene deletion variant of ACTRT1 in two infertile males, which was inherited from their mothers, respectively. The probands exhibited sperm head deformations owing to acrosomal detachment, which is consistent with our previous observations on Actrt1-KO mice. Decreased expression and ectopic distribution of ACTL7A and phospholipase C zeta were observed in sperm samples from the probands. ICSI combined with AOA effectively solved the fertilization problem in Actrt1-KO mice and in one of the two probands.
CONCLUSIONS: Additional cases are needed to further confirm the genetic contribution of ACTRT1 variants to male infertility.
CONCLUSIONS: Our results reveal a gene-disease relation between the ACTRT1 deletion described here and human male infertility owing to acrosomal detachment and fertilization failure. This report also describes a good reproductive outcome of ART with ICSI-AOA for a proband.
BACKGROUND: This work was supported by the Chongqing medical scientific research project (Joint project of Chongqing Health Commission and Science and Technology Bureau, 2023MSXM008 and 2023MSXM054). There are no competing interests to declare.
BACKGROUND: N/A.