Biology subjects

Vinod, M.

Publications and source records attributed to Vinod, M..

3 recordsLinked to original sources

bioRxiv2023

SMYD5 is a novel epigenetic gatekeeper of the mild hypothermia response

The mild hypothermia response (MHR) maintains organismal homeostasis during cold exposure and is thought to be critical for the neuroprotection documented with therapeutic hypothermia. To date, little is known about the transcriptional regulation of the MHR. We utilize a forward CRISPR-Cas9 mutagenesis screen to identify the histone lysine methyltransferase SMYD5 as a regulator of the MHR. SMYD5 represses the key MHR gene SP1 at euthermia. This repression correlates with temperature-dependent levels of H3K36me3 at the SP1-locus and globally, indicating that the mammalian MHR is regulated at the level of histone modifications. We have identified 37 additional SMYD5 regulated temperature-dependent genes, suggesting a broader MHR-related role for SMYD5. Our study provides an example of how histone modifications integrate environmental cues into the genetic circuitry of mammalian cells and provides insights that may yield therapeutic avenues for neuroprotection after catastrophic events.

genetics↗

bioRxiv2023

L1 retrotransposons drive human neuronal transcriptome complexity and functional diversification

The genetic mechanisms underlying the expansion in size and complexity of the human brain remains poorly understood. L1 retrotransposons are a source of divergent genetic information in hominoid genomes, but their importance in physiological functions and their contribution to human brain evolution is largely unknown. Using multi-omic profiling we here demonstrate that L1-promoters are dynamically active in the developing and adult human brain. L1s generate hundreds of developmentally regulated and cell-type specific transcripts, many which are co-opted as chimeric transcripts or regulatory RNAs. One L1-derived lncRNA, LINC01876, is a human-specific transcript expressed exclusively during brain development. CRISPRi-silencing of LINC01876 results in reduced size of cerebral organoids and premature differentiation of neural progenitors, implicating L1s in human-specific developmental processes. In summary, our results demonstrate that L1-derived transcripts provide a previously undescribed layer of primate- and human-specific transcriptome complexity that contributes to the functional diversification of the human brain.

neuroscience↗

bioRxiv2023

A time- and space-resolved nuclear receptor atlas in mouse liver

The unique functional versatility of the liver is paramount for organismal homeostasis. Both liver development and adult functions are controlled by tightly regulated transcription factor networks, within which nuclear receptors regulate essential functions of parenchymal and non-parenchymal cells. Acting as transcription factors sensitive to extracellular cues such as steroidal hormones, lipid metabolites, xenobiotics... and modulated by intracellular signaling pathways, nuclear receptors orchestrate many aspects of hepatic physiology. While liver functional zonation and adaptability to fluctuating conditions are known to rely on a sophisticated cellular architecture, a comprehensive knowledge of nuclear receptor functions in the different liver cell types is still lacking. As a first step toward the accurate mapping of nuclear receptor functions in mouse liver, we characterized their levels of expression in whole liver as a function of time and diet, and explored nuclear receptor isoform expression in hepatocytes, cholangiocytes, Kupffer cells, hepatic stellate cells and liver sinusoidal cells. In addition, we leveraged liver single cell RNAseq studies to provide here an up-to-date compendium of nuclear receptor expression in mouse liver in space and time.

molecular biology↗