Deficiency in AK9 causes asthenozoospermia and male infertility by destabilising sperm nucleotide homeostasis

Yanwei Sha; Wensheng Liu; Shu Li; Ludmila V Osadchuk; Yongjie Chen; Hua Nie; Shuai Gao; Linna Xie; Weibing Qin; Huiliang Zhou; Lin Li

doi:10.1016/j.ebiom.2023.104798

Deficiency in AK9 causes asthenozoospermia and male infertility by destabilising sperm nucleotide homeostasis

EBioMedicine. 2023 Oct:96:104798. doi: 10.1016/j.ebiom.2023.104798. Epub 2023 Sep 13.

Authors

Yanwei Sha¹, Wensheng Liu², Shu Li³, Ludmila V Osadchuk⁴, Yongjie Chen⁵, Hua Nie², Shuai Gao³, Linna Xie⁶, Weibing Qin⁷, Huiliang Zhou⁸, Lin Li⁹

Affiliations

¹ Department of Andrology, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China; State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, Fujian, China.
² NHC Key Laboratory of Male Reproduction and Genetics, Guangdong Provincial Reproductive Science Institute (Guangdong Provincial Fertility Hospital), Guangzhou, Guangdong, China.
³ Fujian Provincial Key Laboratory of Reproductive Health Research, School of Medicine, Xiamen University, Xiamen, Fujian, China.
⁴ The Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
⁵ Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Dongcheng, Beijing, China.
⁶ State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, Fujian, China.
⁷ NHC Key Laboratory of Male Reproduction and Genetics, Guangdong Provincial Reproductive Science Institute (Guangdong Provincial Fertility Hospital), Guangzhou, Guangdong, China. Electronic address: qinwb@gdszjk.org.cn.
⁸ Department of Andrology, First Affiliated Hospital of Fujian Medical University, No.20, Chazhong Road, Fuzhou, Fujian, China. Electronic address: zhlpaper@fjmu.edu.cn.
⁹ Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Dongcheng, Beijing, China. Electronic address: linlithu@ccmu.edu.cn.

Abstract

Background: Asthenozoospermia is the primary cause of male infertility; however, its genetic aetiology remains poorly understood. Adenylate kinase 9 (AK9) is highly expressed in the testes of humans and mice and encodes a type of adenosine kinase that is functionally involved in cellular nucleotide homeostasis and energy metabolism. We aimed to assess whether AK9 is involved in asthenozoospermia.

Methods: One-hundred-and-sixty-five Chinese men with idiopathic asthenozoospermia were recruited. Whole-exome sequencing (WES) and Sanger sequencing were performed for genetic analyses. Papanicolaou staining, Haematoxylin and eosin staining, scanning electron microscopy, and transmission electron microscopy were used to observe the sperm morphology and structure. Ak9-knockout mice were generated using CRISPR-Cas9. Sperm adenosine was detected by liquid chromatography-mass spectrometry. Targeted sperm metabolomics was performed. Intracytoplasmic sperm injection (ICSI) was used to treat patients.

Findings: We identified five patients harbouring bi-allelic AK9 mutations. Spermatozoa from men harbouring bi-allelic AK9 mutations have a decreased ability to sustain nucleotide homeostasis. Moreover, bi-allelic AK9 mutations inhibit glycolysis in sperm. Ak9-knockout male mice also presented similar phenotypes of asthenozoospermia. Interestingly, ICSI was effective in bi-allelic AK9 mutant patients in achieving good pregnancy outcomes.

Interpretation: Defects in AK9 induce asthenozoospermia with defects in nucleotide homeostasis and energy metabolism. This sterile phenotype could be rescued by ICSI.

Funding: The National Natural Science Foundation of China (82071697), Medical Innovation Project of Fujian Province (2020-CXB-051), open project of the NHC Key Laboratory of Male Reproduction and Genetics in Guangzhou (KF202004), Medical Research Foundation of Guangdong Province (A2021269), Guangdong Provincial Reproductive Science Institute Innovation Team grants (C-03), and Outstanding Young Talents Program of Capital Medical University (B2205).

Keywords: AK9; Asthenozoospermia; Energetic metabolism; Intracytoplasmic sperm injection; Nucleotide homeostasis.

MeSH terms

Animals
Asthenozoospermia* / genetics
Asthenozoospermia* / metabolism
Female
Humans
Infertility, Male* / genetics
Infertility, Male* / metabolism
Male
Mice
Nucleotides / metabolism
Pregnancy
Semen
Spermatozoa

Substances

Nucleotides