MicroRNA changes in human arterial endothelial cells with senescence: Relation to apoptosis, eNOS and inflammation

Abstract

A senescent phenotype in endothelial cells is associated with increased apoptosis, reduced endothelial nitric oxide synthase (eNOS) and inflammation, which are implicated in arterial dysfunction and disease in humans. We tested the hypothesis that changes in microRNAs are associated with a senescent phenotype in human aortic endothelial cells (HAEC). Compared with early-passage HAEC, late-passage HAEC had a reduced proliferation rate and increased staining for senescence-associated beta-galactosidase and the tumor suppressor p16INK4a. Late-passage senescent HAEC had reduced expression of proliferation-stimulating/apoptosis-suppressing miR-21, miR-214 and miR-92 and increased expression of tumor suppressors and apoptotic markers. eNOS-suppressing miR-221 and miR-222 were increased and eNOS protein and eNOS activation (phosphorylation at serine1177) were lower in senescent HAEC. Caveolin-1 inhibiting miR-133a was reduced and caveolin-1, a negative regulator of eNOS activity, was elevated in senescent HAEC. Inflammation-repressing miR-126 was reduced and inflammation–stimulating miR-125b was increased, whereas inflammatory proteins were greater in senescent HAEC. Development of a senescent arterial endothelial cell phenotype featuring reduced cell proliferation, enhanced apoptosis and inflammation and reduced eNOS is associated with changes in miRNAs linked to the regulation of these processes. Our results support the hypothesis that miRNAs could play a critical role in arterial endothelial cell senescence.

The regulatory role of microRNAs in angiogenesis‐related diseases

“…Many studies reported that miR‐221 and miR‐222 have the effect of promoting and/or inhibiting tumour angiogenesis in the malignant processes of HCC,62 breast cancer,63 lung cancer,64 human epithelial cancers,65 human glioblastoma,66 gastric cancer 67 and other various cancers 60, 61, 68, 69, 70, 71. MiR‐221 and miR‐222 inhibit angiogenesis by blocking tube formation, proliferation, migration and wound healing through repressing the expression of c‐Kit and endothelial nitric oxide synthase (eNOS) 24, 26, 72, 73. Moreover, they both suppress angiogenesis by reducing zinc finger E‐box binding homeobox 2 (ZEB2) in ECs 74…”

Role of Micro-RNAs 221/222 on Statin Induced Nitric Oxide Release in Human Endothelial Cells

“…Endothelial cells transfected with miRs-221/222 showed a reduction in both eNOS protein level and release of NO 21 . However, the direct mechanism by which these miRs may exert that effect is unknown because there is no target region for miRs-221/222 in the NOS3 mRNA molecule generating a mRNA:miR interaction according to the predictive analysis by bioinformatics tools.…”

MicroRNAs; easy and potent targets in optimizing therapeutic methods in reparative angiogenesis

“…For instance, induced senescence in human ECs has been addressed to reduce expression levels of proliferation‐stimulating/apoptosis‐suppressing miR‐17–92, ‐21 and ‐214, in contrast to tumour suppressor p16 and miR‐222 family for suppression of endothelial nitric oxide synthase (eNOS) 23. Down‐regulation of miR‐126 and ‐130a, in particular, impairs EC proliferation, migration and angiogenesis.…”

“…Between them, miR‐126, ‐17–92 and ‐221 are most known to control the growth of new blood vessels 23.…”

“…The anti‐inflammatory miR‐126 is also a negative regulator of endothelial senescence, and is reduced in senescent ECs, while pro‐inflammatory miR‐146, ‐221 are increased 23, 26.…”