iPSC reprogramming-mediated aneuploidy correction in autosomal trisomy syndromes

PLoS One. 2022 Mar 10;17(3):e0264965. doi: 10.1371/journal.pone.0264965. eCollection 2022.

Abstract

Trisomy 21, 18, and 13 are the major autosomal aneuploidy disorders in humans. They are mostly derived from chromosome non-disjunction in maternal meiosis, and the extra trisomic chromosome can cause several congenital malformations. Various genes on the trisomic chromosomes are intricately involved in the development of disease, and fundamental treatments have not yet been established. However, chromosome therapy has been developed to correct the extra chromosome in cultured patient cells, and it was recently reported that during reprogramming into iPSCs, fibroblasts from a Down syndrome patient lost the extra chromosome 21 due to a phenomenon called trisomy-biased chromosome loss. To gain preliminary insights into the underlying mechanism of trisomy rescue during the early stages of reprogramming, we reprogrammed skin fibroblasts from patients with trisomy syndromes 21, 18, 13, and 9 to iPSC, and evaluated the genomes of the individual iPSC colonies by molecular cytogenetic techniques. We report the spontaneous correction from trisomy to disomy upon cell reprogramming in at least one cell line examined from each of the trisomy syndromes, and three possible combinations of chromosomes were selected in the isogenic trisomy-rescued iPSC clones. Single nucleotide polymorphism analysis showed that the trisomy-rescued clones exhibited either heterodisomy or segmental uniparental isodisomy, ruling out the possibility that two trisomic chromosomes were lost simultaneously and the remaining one was duplicated, suggesting instead that one trisomic chromosome was lost to generate disomic cells. These results demonstrated that trisomy rescue may be a phenomenon with random loss of the extra chromosome and subsequent selection for disomic iPSCs, which is analogous to the karyotype correction in early preimplantation embryos. Our finding is relevant for elucidating the mechanisms of autonomous karyotype correction and future application in basic and clinical research on aneuploidy disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aneuploidy
  • Chromosomes
  • Down Syndrome* / genetics
  • Humans
  • Induced Pluripotent Stem Cells*
  • Mosaicism
  • Trisomy / genetics
  • Uniparental Disomy

Grants and funding

This work was supported by the Project for Baby and Infant in Research of Health and Development to Adolescent and Young Adult (BIRTHDAY) from the Japan Agency for Medical Research and Developmental, AMED (to S.M.: 18950264); Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (to S.M.: 15H04321 and 19K22515, to S.N.A.: 19K16520, to T.M.: 21H02718 and 20K21845); Grant-in-Aid for Scientific Research from the Ministry of Health, Labour and Welfare of Japan (to S.M.: 20316866); and the Program of the Network-type Joint Usage/Research Center for Radiation Disaster Medical Science (to S.M. and T.M.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.