Long Range Endocrine Delivery of Circulating miR-210 to Endothelium Promotes Pulmonary Hypertension.

Circulation research 2020 Aug 14

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Unproven theories abound regarding the long-range uptake and endocrine activity of extracellular blood-borne microRNAs into tissue. In pulmonary hypertension (PH), microRNA-210 (miR-210) in pulmonary endothelial cells promotes disease, but its activity as an extracellular molecule is incompletely defined. We investigated whether chronic and endogenous endocrine delivery of extracellular miR-210 to pulmonary vascular endothelial cells promotes PH. Using miR-210 replete (wild-type [WT]) and knockout mice, we tracked blood-borne miR-210 using bone marrow transplantation and parabiosis (conjoining of circulatory systems). With bone marrow transplantation, circulating miR-210 was derived predominantly from bone marrow. Via parabiosis during chronic hypoxia to induce miR-210 production and PH, miR-210 was undetectable in knockout-knockout mice pairs. However, in plasma and lung endothelium, but not smooth muscle or adventitia, miR-210 was observed in knockout mice of WT-knockout pairs. This was accompanied by downregulation of miR-210 targets ISCU (iron-sulfur assembly proteins)1/2 and COX10 (cytochrome c oxidase assembly protein-10), indicating endothelial import of functional miR-210. Via hemodynamic and histological indices, knockout-knockout pairs were protected from PH, whereas knockout mice in WT-knockout pairs developed PH. In particular, pulmonary vascular engraftment of miR-210-positive interstitial lung macrophages was observed in knockout mice of WT-knockout pairs. To address whether engrafted miR-210-positive myeloid or lymphoid cells contribute to paracrine miR-210 delivery, we studied miR-210 knockout mice parabiosed with miR-210 WT; Cx3cr1 knockout mice (deficient in myeloid recruitment) or miR-210 WT; Rag1 knockout mice (deficient in lymphocytes). In both pairs, miR-210 knockout mice still displayed miR-210 delivery and PH, thus demonstrating a pathogenic endocrine delivery of extracellular miR-210. Endogenous blood-borne transport of miR-210 into pulmonary vascular endothelial cells promotes PH, offering fundamental insight into the systemic physiology of microRNA activity. These results also describe a platform for RNA-mediated crosstalk in PH, providing an impetus for developing blood-based miR-210 technologies for diagnosis and therapy in this disease.

Citation

Jingsi Zhao, Jonathan Florentin, Yi-Yin Tai, Stéphanie Torrino, Lee Ohayon, Tomasz Brzoska, Ying Tang, Jimin Yang, Vinny Negi, Chen-Shan Chen Woodcock, Michael G Risbano, Seyed Mehdi Nouraie, Prithu Sundd, Thomas Bertero, Partha Dutta, Stephen Y Chan. Long Range Endocrine Delivery of Circulating miR-210 to Endothelium Promotes Pulmonary Hypertension. Circulation research. 2020 Aug 14;127(5):677-692