Project description:We found that the non-essential amino acid L-Proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells. This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the transcriptome We used microarrays to elucidate whether a diverse transcriptional program is the basis of the morphological and motility differences between ESCs and L- Proline treated ESCs (PiCs) Total RNA was extracted from Control (ESCs) and L-Proline treated mouse embryonic stem cells (PiCs) and hybridized on Affimetrix microarrays.
Project description:Lipid metabolism is recognized as a key process for stem cell maintenance and differentiation but genetic factors that instruct stem cell function by influencing lipid metabolism remain to be delineated. Here we identify Tnfaip2 as an inhibitor of reprogramming of mouse fibroblasts into induced pluripotent stem cells. Tnfaip2 knockout embryonic stem cells (ESCs) exhibit differentiation failure and knockdown of the planarian orthologue, Smed-exoc3, abrogates in vivo differentiation of somatic stem cells, tissue homeostasis, and regeneration. Tnfaip2 deficient ESCs fail to induce synthesis of cellular triacylglycerol (TAG) and lipid droplets (LD) coinciding with reduced expression of Vimentin (Vim) – a known inducer of LD formation. Knockdown of Vim and Tnfaip2 act epistatically in enhancing cellular reprogramming of mouse fibroblasts. Similarly, planarians devoid of Smed-exoc3 displayed acute loss of TAGs. Supplementation of palmitic acid (PA) and palmitoyl-L-carnitine (a mitochondrial carrier of PA) restores the differentiation capacity of Tnfaip2 deficient ESCs as well as stem cell differentiation and organ maintenance in Smed-exoc3-depleted planarians. Together, these results identify a novel pathway, which is essential for stem cell differentiation and organ maintenance by instructing lipid metabolism.
Project description:Lipid metabolism is recognized as a key process for stem cell maintenance and differentiation but genetic factors that instruct stem cell function by influencing lipid metabolism remain to be delineated. Here we identify Tnfaip2 as an inhibitor of reprogramming of mouse fibroblasts into induced pluripotent stem cells. Tnfaip2 knockout embryonic stem cells (ESCs) exhibit differentiation failure and knockdown of the planarian orthologue, Smed-exoc3, abrogates in vivo differentiation of somatic stem cells, tissue homeostasis, and regeneration. Tnfaip2 deficient ESCs fail to induce synthesis of cellular triacylglycerol (TAG) and lipid droplets (LD) coinciding with reduced expression of Vimentin (Vim) – a known inducer of LD formation. Knockdown of Vim and Tnfaip2 act epistatically in enhancing cellular reprogramming of mouse fibroblasts. Similarly, planarians devoid of Smed-exoc3 displayed acute loss of TAGs. Supplementation of palmitic acid (PA) and palmitoyl-L-carnitine (a mitochondrial carrier of PA) restores the differentiation capacity of Tnfaip2 deficient ESCs as well as stem cell differentiation and organ maintenance in Smed-exoc3-depleted planarians. Together, these results identify a novel pathway, which is essential for stem cell differentiation and organ maintenance by instructing lipid metabolism.
Project description:We found that the non-essential amino acid L-proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells.This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the H3K9me3 and H3K36me3 histone marks. Examination of 2 different histone modifications in untreated ESCs and L-Pro treated ESCs
Project description:We found that the non-essential amino acid L-Proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells. This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the transcriptome We used microarrays to elucidate whether a diverse transcriptional program is the basis of the morphological and motility differences between ESCs and L- Proline treated ESCs (PiCs)
Project description:The role of mitochondria dynamics and its molecular regulators remains largely unknown during naïve-to-primed pluripotent cell interconversion. Here we report that mitochondrial MTCH2 is a regulator of mitochondrial fusion, essential for the naïve-to-primed interconversion of murine embryonic stem cells (ESCs). During this interconversion, wild-type ESCs elongate their mitochondria and slightly alter their glutamine utilization. In contrast, MTCH2-/- ESCs fail to elongate their mitochondria and to alter their metabolism, maintaining high levels of histone acetylation and expression of naïve pluripotency markers. Importantly, enforced mitochondria elongation by the pro-fusion protein Mitofusin (MFN) 2 or by a dominant negative form of the pro-fission protein dynamin-related protein (DRP) 1 is sufficient to drive the exit from naïve pluripotency of both MTCH2-/- and wild-type ESCs. Taken together, our data indicate that mitochondria elongation, governed by MTCH2, plays a critical role and constitutes an early driving force in the naïve-to-primed pluripotency interconversion of murine ESCs.