bioRxiv Science⌕ Search

Biology subjects

Lejri, I.

Publications and source records attributed to Lejri, I..

2 recordsLinked to original sources

Human iPSCs from aged donors retain their mitochondrial aging signature

Aging represents the main risk factor for developing neurodegenerative disorders. One of the hallmarks of aging is mitochondrial dysfunction. Age-related mitochondrial alterations have been shown to affect mitochondrial energy metabolism and redox homeostasis as well as mitochondrial dynamics. In the present study, we addressed the question of whether or not, induced pluripotent stem cells (iPSCs) may be used as a model of "aging in a dish" to identify therapies at alleviating the aging of mitochondria. Notably, we could demonstrate that compared to human iPSCs from young donors, those from aged donors show impaired mitochondrial bioenergetics and exhibit a rise in reactive oxygen species generation. Furthermore, we demonstrate that iPSCs from aged donors present low mitochondrial mass and alterations of the morphology of the mitochondrial network. This study provides evidence that the aging phenotype is present at the mitochondrial level in iPSCs from aged donors, ranging from bioenergetics to dynamics. Thus, this model can be used for high through put screening to identify drugs that improve mitochondrial function. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=157 SRC="FIGDIR/small/589733v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@17c5ccorg.highwire.dtl.DTLVardef@bae9aaorg.highwire.dtl.DTLVardef@142d8e6org.highwire.dtl.DTLVardef@1adf519_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Preservation of an Aging-Associated Mitochondrial Signature in Advanced Human Neuronal Models

1.This study investigated whether induced pluripotent stem cell-derived neurons (iPSCsNs) and directly converted neurons (iNs) generated from the same cells of origin (human fibroblasts) represent aging-related characteristics on mitochondrial levels. There is still uncertainty regarding the potential for rejuvenation or preservation of an aging-associated donor signature in aged iPSCsNs upon transition through pluripotent states, while direct conversion retains the aging-associated mitochondrial impairments. Surprisingly, both aged neuronal models exhibited age-associated donor phenotypes, including decreased ATP, mitochondrial membrane potential, mitochondrial respiration, NAD+/NADH ratio, and increased radical levels and mitochondrial mass. Besides, a fragmented mitochondrial network was observed in both aged neuronal models. However, unlike aged iNs, aged iPSCsNs did not show a metabolic shift towards anaerobic glycolysis to compensate for the energy deficit. Moreover, the mRNA expression profile significantly differed between aged iPSCsNs and aged iNs. Our study indicates that aged iPSCsNs may experience rejuvenation in certain parameters, such as transcriptomics and the aging-associated glycolytic shift. Nevertheless, aged iPSCsNs can be a valuable tool for studying neuronal aging of mitochondrial parameters in vitro alongside aged iNs.

neuroscience↗