Given the relatively long life of stem cells (SCs), efficient mechanisms of quality control to balance cell survival and resistance to external and internal stress are required. Our objective was to test the relevance of cell quality control mechanisms for SCs maintenance, differentiation and resistance to cell death. We compared cell quality control in P19 stem cells (P19SCs) before and after differentiation (P19dCs). Differentiation of P19SCs resulted in alterations in parameters involved in cell survival and protein homeostasis, including the redox system,
cardiolipin and
lipid profiles, unfolded protein response,
ubiquitin-
proteasome and lysosomal systems, and signaling pathways controlling cell growth. In addition, P19SCs pluripotency was correlated with stronger
antioxidant protection, modulation of apoptosis, and activation of macroautophagy, which all contributed to preserve SCs quality by increasing the threshold for cell death activation. Furthermore, our findings identify critical roles for the PI3K-AKT-MTOR pathway, as well as autophagic flux and apoptosis regulation in the maintenance of P19SCs pluripotency and differentiation potential.Abbreviations: 3-MA: 3-methyladenine; AKT/
protein kinase B:
thymoma viral proto-oncogene; AKT1:
thymoma viral proto-oncogene 1; ATG: AuTophaGy-related; ATF6:
activating transcription factor 6; BAX:
BCL2-associated X protein; BBC3/PUMA:
BCL2 binding component 3; BCL2:
B cell leukemia/
lymphoma 2; BNIP3L: BCL2/adenovirus E1B interacting
protein 3-like;
CASP3:
caspase 3; CASP8:
caspase 8; CASP9:
caspase 9; CL:
cardiolipin; CTSB:
cathepsin B; CTSD:
cathepsin D; DDIT3/CHOP: DNA-damage inducible transcript 3; DNM1L/DRP1:
dynamin 1-like; DRAM1: DNA-damage regulated autophagy modulator 1; EIF2AK3/PERK: eukaryotic translation
initiation factor 2 alpha
kinase 3; EIF2S1/eIF2α: eukaryotic translation
initiation factor 2, subunit alpha; ERN1/IRE1α: endoplasmic reticulum to nucleus signaling 1; ESCs: embryonic stem cells; KRT8/TROMA-1:
cytokeratin 8; LAMP2A:
lysosomal-associated membrane protein 2A; MAP1LC3/LC3:
microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of
rapamycin kinase; NANOG: Nanog homeobox;
NAO: 10-N-nonyl
acridine orange; NFE2L2/NRF2: nuclear factor, erythroid derived 2, like 2; OPA1: OPA1, mitochondrial
dynamin like
GTPase; P19dCs: P19 differentiated cells; P19SCs: P19 stem cells; POU5F1/OCT4:
POU domain, class 5, transcription factor 1; PtdIns3K:
phosphatidylinositol 3-kinase; RA:
retinoic acid; ROS:
reactive oxygen species; RPS6KB1/
p70S6K:
ribosomal protein S6 kinase,
polypeptide 1; SCs: stem cells; SOD:
superoxide dismutase; SHC1-1/p66SHC:
src homology 2 domain-containing transforming protein C1, 66 kDa
isoform; SOX2: SRY (sex determining region Y)-box 2; SQSTM1/p62: sequestosome 1; SPTAN1/αII-
spectrin:
spectrin alpha, non-erythrocytic 1; TOMM20: translocase of outer mitochondrial membrane 20; TRP53/p53: transformation related
protein 53; TUBB3/betaIII-
tubulin:
tubulin, beta 3 class III; UPR: unfolded protein response; UPS:
ubiquitin-
proteasome system.