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Biology subjects

Oni-Orisan, A.

Publications and source records attributed to Oni-Orisan, A..

3 recordsLinked to original sources

MIR192 Upregulates GLP-1 Receptor and Improves Statin-Induced Impairment of Insulin Secretion

Statins are a commonly prescribed cholesterol lowering drug class that can increase the risk of new-onset diabetes (NOD). To investigate the molecular mechanisms underlying this effect, we generated human induced pluripotent stem cells (iPSCs) from individuals identified from electronic health records of Kaiser Permanente of Northern California who were susceptible to developing NOD after statin initiation or controls who maintained stable fasting glucose on statin treatment. RNA-seq analysis of iPSCs incubated with atorvastatin, simvastatin or mock buffer for 24 hours identified the long non-coding RNA MIR194-2HG as a top candidate gene. Statin-induced increases in its expression were observed in NOD resistant controls, while statin-induced reductions occurred in NOD susceptible cases. MIR194-2HG encompasses two microRNA genes: MIR192 and MIR194-2. The mature microRNA miR-192-5p, derived from the 5 arm of MIR192, was predicted to bind the 3UTR of the glucagon like peptide 1 (GLP-1) receptor (GLP1R) transcript. Transfection of a rat insulinoma cell line INS-1 with a miR-192-5p mimic increased Glp1r transcript (1.41-fold) and protein (1.51-fold) levels compared to a scrambled control. Using a luciferase reporter containing the human GLP1R 3UTR, miR-192-5p overexpression similarly increased luciferase signal (1.44-fold). The miR-192-5p mimic enhanced glucose stimulated insulin secretion (GSIS) in response to GLP1R agonists (1.64-1.81-fold) and rescued simvastatin-induced GSIS impairment in INS-1 cells. Wild-type mice treated with miR-192 AAV8 had improved glucose sensitivity. Islets isolated from these mice exhibited enhanced GLP-1 potentiated GSIS during perifusion ex vivo. These effects were absent in the DIRKO (Glp1r/Gipr double knockout) mouse islets, consistent with the idea that miR-192 promotes GLP-1 mediated GSIS through GLP1R. These findings implicate MIR192 in statin-induced impairment of GSIS by modulating GLP1R, potentially contributing to the susceptibility to NOD in statin users.

cell biology↗

X chromosome dosage drives statin-induced dysglycemia and mitochondrial dysfunction

Statin drugs lower blood cholesterol levels for cardiovascular disease prevention. Women are more likely than men to experience adverse statin effects, particularly new-onset diabetes (NOD) and muscle weakness. We determined that female mice are more susceptible than males to glucose intolerance, fasting hyperglycemia, and muscle weakness after short-term statin treatment. Lipidomic, transcriptomic, and biochemical analyses identified reduced docosahexaenoic acid (DHA) levels, and impaired redox tone and mitochondrial respiration specifically in statin-treated female mice. Statin adverse effects could be prevented in females by complementation with a source of DHA. Statin adverse effects segregated with XX chromosome complement, and specifically dosage of the Kdm5c gene, which regulates fatty acid gene expression and has differential expression levels in females and males. In humans, we found that women experience more severe reductions than men in DHA levels after short-term statin administration, and that DHA reduction was correlated with increases in fasting glucose levels. Furthermore, induced pluripotent stem cells derived from women, but not men, who developed NOD exhibited impaired mitochondrial function when treated with statin. Overall, our studies identify biochemical mechanisms, biomarkers, and a genetic risk factor for susceptibility to statin adverse effects, and point to DHA supplementation as a preventive co-therapy.

physiology↗

Gene expression in African Americans and Latinos reveals ancestry-specific patterns of genetic architecture

We analyzed whole genome and RNA sequencing data from 2,733 African American and Hispanic/Latino children to explore ancestry- and heterozygosity-related differences in the genetic architecture of whole blood gene expression. We found that heritability of gene expression significantly increases with greater proportion of African genetic ancestry and decreases with higher levels of Indigenous American ancestry, consistent with a relationship between heterozygosity and genetic variance. Among heritable protein-coding genes, the prevalence of statistically significant ancestry-specific expression quantitative trait loci (anc-eQTLs) was 30% in African ancestry and 8% for Indigenous American ancestry segments. Most of the anc-eQTLs (89%) were driven by population differences in allele frequency, demonstrating the importance of measuring gene expression across multiple populations. Transcriptome-wide association analyses of multi-ancestry summary statistics for 28 traits identified 79% more gene-trait pairs using models trained in our admixed population than models trained in GTEx. Our study highlights the importance of large and ancestrally diverse genomic studies for enabling new discoveries of complex trait architecture and reducing disparities.

genetics↗