MicroRNA-mediated downregulation of K+ channels in pulmonary arterial hypertension
Ayon, Ramon J
Ek Vitorin, Jose F
Pohl, Nicole M
Quinton, Brooke A
Ravellette, Keeley S
Vanderpool, Rebecca R
Thistlethwaite, Patricia A
Yuan, Jason X-J
AffiliationUniv Arizona, Dept Med
Univ Arizona, Dept Physiol
MetadataShow full item record
PublisherAMER PHYSIOLOGICAL SOC
CitationBabicheva, A., Ayon, R. J., Zhao, T., Vitorin, J. F. E., Pohl, N. M., Yamamura, A., ... & Ravellette, K. S. (2019). MicroRNA-mediated downregulation of K+ channels in pulmonary arterial hypertension. American Journal of Physiology-Lung Cellular and Molecular Physiology.
RightsCopyright © 2020 the American Physiological Society
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractDownregulated expression of K+ channels and decreased K+ currents in pulmonary artery smooth muscle cells (PASMC) have been implicated in the development of sustained pulmonary vasoconstriction and vascular remodeling in patients with idiopathic pulmonary arterial hypertension (IPAH). However, it is unclear exactly how K+ channels are downregulated in IPAH-PASMC. MicroRNAs (miRNAs) are small non-coding RNAs that are capable of posttranscriptionally regulating gene expression by binding to the 3'-untranslated regions of their targeted mRNAs. Here, we report that specific miRNAs are responsible for the decreased K+ channel expression and function in IPAH-PASMC. We identified 3 miRNAs (miR-29b, miR-138, and miR-222) that were highly expressed in IPAH-PASMC in comparison to normal PASMC (>2.5-fold difference). Selectively upregulated miRNAs are correlated with the decreased expression and attenuated activity of K+ channels. Overexpression of miR-29b, miR-138, or miR-222 in normal PASMC significantly decreased whole cell K+ currents and downregulated voltage-gated K+ channel 1.5 (KV1.5/KCNA5) in normal PASMC. Inhibition of miR-29b in IPAH-PASMC completely recovered K+ channel function and KV1.5 expression, while miR-138 and miR-222 had a partial or no effect. Luciferase assays further revealed that KV1.5 is a direct target of miR-29b. Additionally, overexpression of miR-29b in normal PASMC decreased large-conductance Ca2+-activated K+ (BKCa) channel currents and downregulated BKCa channel β1 subunit (BKCaβ1 or KCNMB1) expression, while inhibition of miR-29b in IPAH-PASMC increased BKCa channel activity and BKCaβ1 levels. These data indicate upregulated miR-29b contributes at least partially to the attenuated function and expression of KV and BKCa channels in PASMC from patients with IPAH.
Note12 month embargo; published online: 25 September 2019
VersionFinal accepted manuscript