Suppression of trinucleotide repeat expansion in spermatogenic cells in Huntington's disease

• Type of Material: Article
• Authors: In-Koo Cho, Emory University; Charles Easley IV, Emory University; Charles A Easley, Emory University; Anthony WS Chan, Emory University
• Language: English
• Date: 2022-09-06
• Publisher: SPRINGER/PLENUM PUBLISHERS
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2022
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1007/s10815-022-02594-x
• Title of Journal or Parent Work: JOURNAL OF ASSISTED REPRODUCTION AND GENETICS
• Volume: 39
• Issue: 10
• Start Page: 2413
• End Page: 2430
• Grant/Funding Information: This study was also supported in part by the Emory University Research Council (HERCULES) awarded to Anthony W.S. Chan and In K. Cho and Arthur and Sarah Merrill Foundation HD Pilot Grant awarded to In K. Cho.; Emory Integrated Genomics Core (EIGC) was supported by Emory University core grant under award number 2P30CA138292. This study was also supported in part by the Transgenic Huntington’s Disease Monkey Resource grant awarded by the ORIP/NIH (OD010930) to Anthony W.S. Chan. OD020182 and Georgia Partners in Regenerative Medicine Seed Grant to Anthony W.S. Chan and Charles. A. Easley.; YNPRC is supported by the Office of Research and Infrastructure Program (ORIP)/OD P51OD11132. The Yerkes NHP Genomics Core is supported in part by NIH P51 OD011132.
• Keywords: BISPHENOL-A; Reproductive Biology; Genetics & Heredity; ARA-C; STEM-CELLS; BASE EXCISION-REPAIR; KNOCK-IN MICE; Aspirin; Spermatogenesis; Huntington's disease; HUMAN AP ENDONUCLEASE; Life Sciences & Biomedicine; Science & Technology; MECHANISM; Drug discovery; Cytarabine (AraC); Trinucleotide repeats; INSTABILITY; CAG REPEAT; Obstetrics & Gynecology; DNA-REPAIR
• Research Categories: Health Sciences, Public Health

Abstract

Trinucleotide repeats (TNRs) are dispersed throughout the human genome. About 20 loci are related to human diseases, such as Huntington’s disease (HD). A larger TNR instability is predominantly observed in the paternal germ cells in some TNR disorders. Suppressing the expansion during spermatogenesis can provide a unique opportunity to end the vicious cycle of genetic anticipation. Here, using an in vitro differentiation method to derive advanced spermatogenic cells, we investigated the efficacy of two therapeutic agents, araC (cytarabine) and aspirin, on stabilizing TNRs in spermatogenic cells. Two WT patient-derived induced pluripotent stem cell (iPSC) lines and two HD hiPSC lines, with 44 Q and 180 Q, were differentiated into spermatogonial stem cell-like cells (SSCLCs). Both HD cell lines showed CAG tract expansion in SSCLC. When treated with araC and aspirin, HD1 showed moderate but not statistically significant stabilization of TNR. In HD2, 10 nM of aspirin and araC showed significant stabilization of TNR. All cell lines showed increased DNA damage response (DDR) gene expression in SSCLCs while more genes were significantly induced in HD SSCLC. In HD1, araC and aspirin treatment showed general suppression of DNA damage response genes. In HD2, only FAN1, OGG1, and PCNA showed significant suppression. When the methylation profile of HD cells was analyzed, FAN1 and OGG1 showed significant hypermethylation after the aspirin and araC treatment in SSCLC compared to the control. This study underscores the utility of our in vitro spermatogenesis model to study and develop therapies for TNR disorders such as HD.