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Kevin S Smith

Publications and source records attributed to Kevin S Smith.

2 recordsLinked to original sources

A community overlap strategy reveals central genes and networks in heart failure

Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvested 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtained genome-wide genotyping and gene expression measurements for a subset of 313. We built failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs). PPP1R3A emerged as a novel regulator whose network connectivity changed significantly between health and disease. Time-course RNA sequencing after PPP1R3A knock-down validated network-based predictions of metabolic pathway expression, increased cardiomyocyte size, and perturbed respiratory metabolism. Mice lacking PPP1R3A were protected against pressure-overload heart failure. We present a global gene interaction map of the human heart failure transition, identify new cardiac eQTLs, and demonstrate the discovery potential of disease-specific networks through the description of PPP1R3A as a novel central protective regulator in heart failure.

Genomics

Impact of the X chromosome and sex on regulatory variation

The X chromosome, with its unique mode of inheritance, contributes to differences between the sexes at a molecular level, including sex-specific gene expression and sex-specific impact of genetic variation. We have conducted an analysis of the impact of both sex and the X chromosome on patterns of gene expression identified through transcriptome sequencing of whole blood from 922 individuals. We identified that genes on the X chromosome are more likely to have sex-specific expression compared to the autosomal genes. Furthermore, we identified a depletion of regulatory variants on the X chromosome, especially among genes under high selective constraint. In contrast, we discovered an enrichment of sex-specific regulatory variants on the X chromosome. To resolve the molecular mechanisms underlying such effects, we generated and connected sex-specific chromatin accessibility to sex-specific expression and regulatory variation. As sex-specific regulatory variants can inform sex differences in genetic disease prevalence, we have integrated our data with genome-wide association study data for multiple immune traits and to identify traits with significant sex biases. Together, our study provides genome-wide insight into how the X chromosome and sex shape human gene regulation and disease.

Genomics