TCF3 Regulates the Proliferation and Apoptosis of Human Spermatogonial Stem Cells by Targeting PODXL

Dai Zhou; Jingyu Fan; Zhizhong Liu; Ruiling Tang; Xingming Wang; Hao Bo; Fang Zhu; Xueheng Zhao; Zenghui Huang; Liu Xing; Ke Tao; Han Zhang; Hongchuan Nie; Huan Zhang; Wenbing Zhu; Zuping He; Liqing Fan

doi:10.3389/fcell.2021.695545

TCF3 Regulates the Proliferation and Apoptosis of Human Spermatogonial Stem Cells by Targeting PODXL

Front Cell Dev Biol. 2021 Aug 6:9:695545. doi: 10.3389/fcell.2021.695545. eCollection 2021.

Authors

Dai Zhou^{1

2

3

4

5}, Jingyu Fan⁶, Zhizhong Liu^{1

7}, Ruiling Tang^{1

2}, Xingming Wang^{1

2}, Hao Bo^{1

2}, Fang Zhu^{1

2}, Xueheng Zhao^{1

2}, Zenghui Huang^{1

2}, Liu Xing^{1

2}, Ke Tao^{1

2

8}, Han Zhang^{1

2}, Hongchuan Nie^{1

2}, Huan Zhang^{1

2}, Wenbing Zhu^{1

2}, Zuping He⁸, Liqing Fan^{1

2

4

5}

Affiliations

¹ Institute of Reproduction and Stem Cell Engineering, School of Basic Medicine Science, Central South University, Changsha, China.
² Reproductive & Genetic Hospital of CITIC-Xiangya, Changsha, China.
³ College of Life Sciences, Hunan Normal University, Changsha, China.
⁴ Clinical Research Center for Reproduction and Genetics in Hunan Province, Changsha, China.
⁵ NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, Central South University, Changsha, China.
⁶ Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, United States.
⁷ Department of Urology, Hunan Cancer Hospital, Changsha, China.
⁸ The Key Laboratory of Model Animals and Stem Cell Biology in Hunan Province, Hunan Normal University School of Medicine, Changsha, China.

Abstract

Spermatogonial stem cells (SSCs) are the initial cells for the spermatogenesis. Although much progress has been made on uncovering a number of modulators for the SSC fate decisions in rodents, the genes mediating human SSCs remain largely unclear. Here we report, for the first time, that TCF3, a member of the basic helix-loop-helix family of transcriptional modulator proteins, can stimulate proliferation and suppress the apoptosis of human SSCs through targeting podocalyxin-like protein (PODXL). TCF3 was expressed primarily in GFRA1-positive spermatogonia, and EGF (epidermal growth factor) elevated TCF3 expression level. Notably, TCF3 enhanced the growth and DNA synthesis of human SSCs, whereas it repressed the apoptosis of human SSCs. RNA sequencing and chromatin immunoprecipitation (ChIP) assays revealed that TCF3 protein regulated the transcription of several genes, including WNT2B, TGFB3, CCN4, MEGF6, and PODXL, while PODXL silencing compromised the stem cell activity of SSCs. Moreover, the level of TCF3 protein was remarkably lower in patients with spermatogenesis failure when compared to individuals with obstructive azoospermia with normal spermatogenesis. Collectively, these results implicate that TCF3 modulates human SSC proliferation and apoptosis through PODXL. This study is of great significance since it would provide a novel molecular mechanism underlying the fate determinations of human SSCs and it could offer new targets for gene therapy of male infertility.

Keywords: PODXL; TCF3; apoptosis; human spermatogonial stem cells; proliferation.