Abstract 12403: Type 1 Diabetes Alters Estrogen-Stimulated microRNA Expression and Impairs Nitric Oxide Production in Human Coronary Artery Endothelial Cells

Abstract

Introduction: Women developed CAD about 1 decade after men. This advantage is erased in T1DM women, and the mechanisms remain unclear. Estrogen (E2) stimulates endothelial NO production via estrogen receptors, and microRNA (miR) have emerged as critical regulators of endothelial function. Whether E2 stimulation of NO production is impaired in T1DM and whether E2 stimulates different miR expression patterns are unknown. Hypothesis: E2-stimulated NO production will be impaired in T1DM endothelial cells which will also express differences in miR expression with E2 exposure. Methods: All experiments were done with and without incubation with 1 nM 17β-estradiol for 24 hours. MicroRNA was isolated from culture human coronary artery endothelial cells (HCAECs) from a woman with and a woman without T1DM. MicroRNA was isolated from HCAECs with four different exposure conditions (T1DM ± 1 nM 17β-estradiol for 24 hr and non-T1DM± 1 nM 17β-estradiol for 24 hr, N=4 biological replicates for all exposures). Fold changes in expression comparing T1DM and non-T1DM cells with and without estradiol stimulation were generated at significance testing performed using DESeq2 with FDR set at 5%. NO production was measured in HCAECs under the same 4 conditions using DAF2-DA and HPLC. Results: 249 miRs were differentially expressed inT1DM HCAECs compared to non-T1DM HCAECs in non-E2 stimulated samples. In E2-stimulated samples, 201 miRs were differentially expressed. Cross-referencing these comparisons showed 16 miRs differentially expressed in T1DM HCAECs relative to non-T1DM HCAECs both with and without E2 stimulation. 4 of these (miRs 548-ar-3p, 625-3p, 369-3p, and 376a-5p) were significantly changed in the opposite direction with estrogen stimulation compared to unstimulated HCAECs, suggesting changes in the expression were due to changes in E2 signaling in T1DM HCAECs. Further, estradiol stimulation of T1DM HCAECS demonstrates a significantly blunted NO production compared to non-T1DM HCAECs (N=6, P<0.05). Conclusions: E2-stimulated NO production is impaired and E2-stimulated changes in miR expression differ in the T1DM endothelium. Further work is necessary to determine whether these differences in miR expression impact E2-stimulated NO production in T1DM.