0000000001315248
AUTHOR
Javier Prieto
Efficient differentiation of embryonic stem cells into mesodermal precursors by BMP, retinoic acid and Notch signalling
The ability to direct differentiation of mouse embryonic stem (ES) cells into specific lineages not only provides new insights into the pathways that regulate lineage selection but also has translational applications, for example in drug discovery. We set out to develop a method of differentiating ES cells into mesodermal cells at high efficiency without first having to induce embryoid body formation. ES cells were plated on a feeder layer of PA6 cells, which have membrane-associated stromal-derived inducing activity (SDIA), the molecular basis of which is currently unknown. Stimulation of ES/PA6 co-cultures with Bone Morphogenetic Protein 4 (BMP4) both favoured self-renewal of ES cells and…
Dysfunctional mitochondrial fission impairs cell reprogramming
We have recently shown that mitochondrial fission is induced early in reprogramming in a Drp1-dependent manner; however, the identity of the factors controlling Drp1 recruitment to mitochondria was unexplored. To investigate this, we used a panel of RNAi targeting factors involved in the regulation of mitochondrial dynamics and we observed that MiD51, Gdap1 and, to a lesser extent, Mff were found to play key roles in this process. Cells derived from Gdap1-null mice were used to further explore the role of this factor in cell reprogramming. Microarray data revealed a prominent down-regulation of cell cycle pathways in Gdap1-null cells early in reprogramming and cell cycle profiling uncovered…
Mitochondrial dynamics and metabolism in induced pluripotency.
Somatic cells can be reprogrammed to pluripotency by either ectopic expression of defined factors or exposure to chemical cocktails. During reprogramming, somatic cells undergo dramatic changes in a wide range of cellular processes, such as metabolism, mitochondrial morphology and function, cell signaling pathways or immortalization. Regulation of these processes during cell reprograming lead to the acquisition of a pluripotent state, which enables indefinite propagation by symmetrical self-renewal without losing the ability of reprogrammed cells to differentiate into all cell types of the adult. In this review, recent data from different laboratories showing how these processes are control…
Early ERK1/2 activation promotes DRP1-dependent mitochondrial fission necessary for cell reprogramming.
During the process of reprogramming to induced pluripotent stem (iPS) cells, somatic cells switch from oxidative to glycolytic metabolism, a transition associated with profound mitochondrial reorganization. Neither the importance of mitochondrial remodelling for cell reprogramming, nor the molecular mechanisms controlling this process are well understood. Here, we show that an early wave of mitochondrial fragmentation occurs upon expression of reprogramming factors. Reprogramming-induced mitochondrial fission is associated with a minor decrease in mitochondrial mass but not with mitophagy. The pro-fission factor Drp1 is phosphorylated early in reprogramming, and its knockdown and inhibition…
c-MYC Triggers Lipid Remodelling During Early Somatic Cell Reprogramming to Pluripotency.
AbstractMetabolic rewiring and mitochondrial dynamics remodelling are hallmarks of cell reprogramming, but the roles of the reprogramming factors in these changes are not fully understood. Here we show that c-MYC induces biosynthesis of fatty acids and increases the rate of pentose phosphate pathway. Time-course profiling of fatty acids and complex lipids during cell reprogramming using lipidomics revealed a profound remodelling of the lipid content, as well as the saturation and length of their acyl chains, in a c-MYC-dependent manner. Pluripotent cells displayed abundant cardiolipins and scarce phosphatidylcholines, with a prevalence of monounsaturated acyl chains. Cells undergoing cell r…
MYC Induces a Hybrid Energetics Program Early in Cell Reprogramming
Summary Cell reprogramming is thought to be associated with a full metabolic switch from an oxidative- to a glycolytic-based metabolism. However, neither the dynamics nor the factors controlling this metabolic switch are fully understood. By using cellular, biochemical, protein array, metabolomic, and respirometry analyses, we found that c-MYC establishes a robust bivalent energetics program early in cell reprogramming. Cells prone to undergo reprogramming exhibit high mitochondrial membrane potential and display a hybrid metabolism. We conclude that MYC proteins orchestrate a rewiring of somatic cell metabolism early in cell reprogramming, whereby somatic cells acquire the phenotypic plast…
Mitochondrial Dynamics: In Cell Reprogramming as It Is in Cancer
Somatic cells can be reprogrammed into a pluripotent cellular state similar to that of embryonic stem cells. Given the significant physiological differences between the somatic and pluripotent cells, cell reprogramming is associated with a profound reorganization of the somatic phenotype at all levels. The remodeling of mitochondrial morphology is one of these dramatic changes that somatic cells have to undertake during cell reprogramming. Somatic cells transform their tubular and interconnected mitochondrial network to the fragmented and isolated organelles found in pluripotent stem cells early during cell reprogramming. Accordingly, mitochondrial fission, the process whereby the mitochond…
Generation of a disease-specific iPS cell line derived from a patient with Charcot-Marie-Tooth type 2K lacking functional GDAP1 gene
Human CMT2-FiPS4F1 cell line was generated from fibroblasts of a patient with Charcot-Marie-Tooth disease harbouring the following mutations in the GDAP1 gene in heterozygosis: p.Q163X/p.T288NfsX3. This patient did not present mutations in the PM22, MPZ or GJB genes. Human reprogramming factors OCT3/4, KLF4, SOX2 and C-MYC were delivered using a non-integrative methodology that involves the use of Sendai virus.
Dysfunctional mitochondrial fission impairs cell reprogramming
We have recently shown that mitochondrial fission is induced early in reprogramming in a Drp1-dependent manner; however, the identity of the factors controlling Drp1 recruitment to mitochondria was unexplored. To investigate this, we used a panel of RNAi targeting factors involved in the regulation of mitochondrial dynamics and we observed that MiD51, Gdap1 and, to a lesser extent, Mff were found to play key roles in this process. Cells derived from Gdap1-null mice were used to further explore the role of this factor in cell reprogramming. Microarray data revealed a prominent down-regulation of cell cycle pathways in Gdap1-null cells early in reprogramming and cell cycle profiling uncovered…