Copyright
©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
SPOC domain-containing protein 1 regulates the proliferation and apoptosis of human spermatogonial stem cells through adenylate kinase 4
Dai Zhou, Fang Zhu, Zeng-Hui Huang, Huan Zhang, Li-Qing Fan, Jing-Yu Fan
Dai Zhou, Fang Zhu, Zeng-Hui Huang, Huan Zhang, Li-Qing Fan, Jing-Yu Fan, Institute of Reproduction and Stem Cell Engineering, School of Basic Medicine Science, Central South University, Changsha 410000, Hunan Province, China
Dai Zhou, Zeng-Hui Huang, Huan Zhang, Li-Qing Fan, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha 410000, Hunan Province, China
Dai Zhou, College of Life Sciences, Hunan Normal University, Changsha 410000, Hunan Province, China
Dai Zhou, Zeng-Hui Huang, Huan Zhang, Li-Qing Fan, Clinical Research Center for Reproduction and Genetics in Hunan Province, Changsha 410000, Hunan Province, China
Jing-Yu Fan, Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, United States
Author contributions: Fan JY designed the study and supervised the laboratory experiments; Zhou D conducted the experiments and drafted the manuscript; Zhu F assisted in bioinformatics analysis; Huang ZH and Zhang H assisted with the experiments and sample collection; Fan LQ contributed new reagents and analytic tools; all authors read and approved the final manuscript.
Supported by the National Natural Science Foundation for Young Scholars of China, No. 82201771; National Natural Science Foundation of China, No. 32270912; Natural Science Foundation of Changsha, No. kq2202491; Research Grant of CITIC-Xiangya, No. YNXM202109 and No. YNXM202115; and Hunan Provincial Grant for Innovative Province Construction, No. 2019SK4012.
Institutional review board statement: The study was reviewed and approved by the Reproductive & Genetic Hospital of CITIC-Xiangya, Basic Medical Science School, Central South University Institutional Review Board (Approval No. LL-SC-2021-025).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Data sharing statement: All data are available from the corresponding author upon reasonable request jingyu@email.sc.edu.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Jing-Yu Fan, MD, PhD, Researcher, Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, GSRC 109, Columbia, SC 29208, United States. jingyu@email.sc.edu
Received: August 4, 2022
Peer-review started: August 4, 2022
First decision: September 29, 2022
Revised: October 7, 2022
Accepted: November 30, 2022
Article in press: November 30, 2022
Published online: December 26, 2022
BACKGROUND
Spermatogonial stem cells (SSCs) are the origin of male spermatogenesis, which can reconstruct germ cell lineage in mice. However, the application of SSCs for male fertility restoration is hindered due to the unclear mechanisms of proliferation and self-renewal in humans.
AIM
To investigate the role and mechanism of SPOC domain-containing protein 1 (SPOCD1) in human SSC proliferation.
METHODS
We analyzed publicly available human testis single-cell RNA sequencing (RNA-seq) data and found that SPOCD1 is predominantly expressed in SSCs in the early developmental stages. Small interfering RNA was applied to suppress SPOCD1 expression to detect the impacts of SPOCD1 inhibition on SSC proliferation and apoptosis. Subsequently, we explored the target genes of SPOCD1 using RNA-seq and confirmed their role by restoring the expression of the target genes. In addition, we examined SPOCD1 expression in some non-obstructive azoospermia (NOA) patients to explore the correlation between SPOCD1 and NOA.
RESULTS
The uniform manifold approximation and projection clustering and pseudotime analysis showed that SPOCD1 was highly expressed in the early stages of SSC, and immunohistological results showed that SPOCD1 was mainly localized in glial cell line-derived neurotrophic factor family receptor alpha-1 positive SSCs. SPOCD1 knockdown significantly inhibited cell proliferation and promoted apoptosis. RNA-seq results showed that SPOCD1 knockdown significantly downregulated genes such as adenylate kinase 4 (AK4). Overexpression of AK4 in SPOCD1 knockdown cells partially reversed the phenotypic changes, indicating that AK4 is a functional target gene of SPOCD1. In addition, we found a significant downregulation of SPOCD1 expression in some NOA patients, suggesting that the downregulation of SPOCD1 may be relevant for NOA.
CONCLUSION
Our study broadens the understanding of human SSC fate determination and may offer new theories on the etiology of male infertility.
Core Tip: In this study, we reported the dominant expression of SPOC domain-containing protein 1 (SPOCD1) in human spermatogonial stem cells (SSCs). Knockdown of SPOCD1 in SSC caused a significant decrease in proliferation and self-renewal, and the induction of apoptosis. RNA sequencing showed that SPOCD1 knockdown caused significant downregulation of genes such as adenylate kinase 4 (AK4), and overexpression of AK4 in SPOCD1-knockdown cells reversed the phenotypic alterations induced by SPOCD knockdown. Additionally, we found significant downregulation of SPOCD1 in non-obstructive azoospermia patients. These results broaden our understanding of human SSC fate determination and provide new theories on the etiology of male infertility.
