Status of KRAS in iPSCs Impacts upon Self-Renewal and Differentiation Propensity

Abstract

SummaryOncogenic KRAS mutations in hematopoietic stem cells cause RAS-associated autoimmune lymphoproliferative syndrome-like disease (RALD). KRAS plays essential roles in stemness maintenance in some types of stem cells. However, its roles in pluripotent stem cells (PSCs) are poorly understood. Here, we investigated the roles of KRAS on stemness in the context of induced PSCs (iPSCs). We used KRAS mutant (G13C/WT) and wild-type isogenic (WT/WT) iPSCs from the same RALD patients, as well as wild-type (WTed/WT) and heterozygous knockout (Δed/WT) iPSCs, both obtained by genome editing from the same G13C/WT clone. Compared with WT iPSCs, G13C/WT iPSCs displayed enforced retention of self-renewal and suppressed capacity for neuronal differentiation, while Δed/WT iPSCs showed normalized cellular characteristics similar to those of isogenic WTed/WT cells. The KRAS-ERK pathway, but not the KRAS-PI3K pathway, was shown to govern these G13C/WT-specific phenotypes, indicating the strong impact of the KRAS-ERK signaling upon self-renewal and differentiation propensity in human iPSCs.

Transcriptome meta-analysis reveals differences of immune profile between eutopic endometrium from stage I-II and III-IV endometriosis independently of hormonal milieu

“…Additionally, these pathways are also extensively reported in other processes such as immunosurveillance 157 , stem cell self-renewal 158 and epithelial to mesenchymal transition 159 . Some of these processes have already been described in endometriosis pathogenesis and they include Kras signalling 160,161 , MYC targets 162,163 , mTORC1 signalling [164][165][166] , PI3K AKT mTOR signalling [167][168][169][170] , TGF beta signalling [171][172][173] , interferon gamma [174][175][176][177] , and interferon alpha response 178,179 . In accordance with our data regarding microenvironment heterogeneity, certain pathways that are enriched in the stage III-IV phenotype are directly associated to M1-M2 macrophage polarization, and these pathways include TGF beta sinalling 180,181 , PI3K AKT mTOR signalling 151,182 , interferon gamma response 79 , adipogenesis, glycolysis and other metabolic reprograming pathways 183 .…”

Neurodevelopmental Aspects of RASopathies

“…Unlike to NF1 , PTPN11 , and HRAS , function of KRAS have not been well studied in the neurodevelopment. Kubara et al (2018) has been shown that activation of KRAS is required for self-renewal of iPSC. In their study, KRAS activation by p.G13C heterozygote mutation suppresses neuronal differentiation suggesting its role during the neurodevelopment.…”

Dynamic genetic regulation of gene expression during cellular differentiation

“…Cell lines in the second, smaller cluster, show high expression of genes related to KRAS activation (Bonferroni p=0.005; gene cluster 4 in Fig. 1B), which is associated with increased self-renewal of undifferentiated iPSCs and decreased neuronal differentiation propensity (14). Other gene clusters illuminate broad changes in gene expression over time such as a transient rise in MYC and E2F target genes in the early days of differentiation (gene cluster 13 in Fig.…”