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Sedivy, L. J.

Publications and source records attributed to Sedivy, L. J..

2 recordsLinked to original sources

Mouse Embryonic Stem Cell Pluripotency Factors Regulate RNA Methylation

The pluripotency of embryonic stem cells (ESCs) is actively promoted by a diverse set of factors, including leukemia inhibitory factor (LIF), glycogen synthase kinase-3 (Gsk-3) and mitogen-activated protein kinase kinase (MEK) inhibitors, ascorbic acid, and -ketoglutarate. Strikingly, several of these factors intersect with the post-transcriptional methylation of RNA (m6A), which has also been shown to play a role in ESC pluripotency. Therefore, we explored the possibility that these factors converge on this biochemical pathway to promote the retention of ESC pluripotency. Mouse ESCs were treated with various combinations of small molecules, and the relative levels of m6A RNA were measured, as well as the expression of genes marking naive and primed ESCs. The most surprising result was the discovery that replacing glucose with high levels of fructose pushed ESCs to a more naive state and reduced m6A RNA abundance. Our results suggest a correlation between molecules previously shown to promote the retention of ESC pluripotency and m6A RNA levels, strengthening a molecular connection between reduced m6A RNA and the pluripotent state, and provides a foundation for future mechanistic studies on the role of m6A and ESC pluripotency.

molecular biology↗

Vitamin C and Transferrin Reduce RNA Methylation in Mouse Embryonic Stem Cells

Methylation of mRNA on adenosine bases (referred to as m6A) is the most common internal modification of mRNA in eukaryotic cells. Recent work has revealed a detailed view of the biological significance of m6A-modified mRNA, with a role in mRNA splicing, control of mRNA stability, and mRNA translation efficiency. Importantly, m6A is a reversible modification, and the primary enzymes responsible for methylating (Mettl3/Mettl14) and demethylating RNA (FTO/Alkbh5) have been identified. Given this reversibility, we are interested in understanding how m6A addition/removal is regulated. Recently, we identified glycogen synthase kinase-3 (Gsk-3) activity as a mediator of m6A regulation via controlling the levels of the FTO demethylase in mouse embryonic stem cells (ESCs), with Gsk-3 inhibitors and Gsk-3 knockout both leading to increased FTO protein and decreased m6A mRNA levels. To our knowledge, this remains one of the only mechanisms identified for the regulation of m6A modifications in ESCs. Several small molecules that have been shown to promote the retention of pluripotency of ESCs, and interestingly, many have connections to the regulation of FTO and m6A. Here we show that the combination of Vitamin C and transferrin potently reduces levels of m6A and promotes retention of pluripotency in mouse ESCs. Combining Vitamin C and transferrin should prove to be valuable in growing and maintaining pluripotent mouse ESCs.

molecular biology↗