Abstract 15513: miR-210 HypoxamiR Stimulates Neoangiogenesis in Response to Peripheral Ischemia
Background: MicroRNA-210 (miR-210) is induced by hypoxia in endothelial cells. The analysis of miR-210-loaded RISC complexes by transcriptomics identified many miR-210 targets involved in cell migration and angiogenesis. Accordingly, miR-210 expression increased endothelial tubulogenesis and VEGF-driven migration in vitro. Here, we investigated the regulation of angiogenesis by miR-210 in peripheral ischemia.
Methods and Results: Transcriptomic analysis by RNA seq of hypoxic endothelial cells showed that MIR210 Host Gene was the most induced long noncoding RNAs (27±1 fold, adj p<1 E-76). Accordingly, its product miR-210 was also increased (35±5 fold; p<0.00001). In keeping with in vitro data, miR-210 was induced 2.9±0.6 fold (p<0.04) in ischemic muscles of a mouse model of hindlimb ischemia induced by femoral artery dissection. miR-210 role was investigated by the administration of miR-210 complementary LNA oligos (anti-210) and in doxycycline-inducible miR-210 transgenic mice (Tg-210). MiR-210 stimulated neoangiogenesis in response to hindlimb ischemia: at day 7, capillary density increased to 155%±4 in Tg-210 (p<0.01) and decreased to 60%±9 in anti-210 mice (p<0.007) compared to relevant controls; arteriolar length density was also induced (Tg-210= 141%±8 and anti-210=72%±5 of controls; both p<0.05). Accordingly, blood perfusion measured by Power Doppler was 146%±8 of the controls for Tg-210 (p<0.003) and 34%±13 for anti-210 (p<0.04). In keeping with a pro-angiogenic role of miR-210, anti-210 administration significantly decreased capillary density in a matrigel plug assay (p<0.02).
To gain insight into the molecular events underpinning miR-210 function, the transcriptomic changes of anti-210 ischemic muscles were analysed, identifying the enrichment of “angiogenesis” and “blood vessel” gene ontology categories. Also differentially distributed were macrophages-related categories, suggesting a pro-inflammatory and anti-regenerative mileu. Indeed, immunohistological analysis revealed a 2.4±1 increase of CD-68+ macrophages (p<0.006) and a 2.3±1 increase of M1/M2 ratio (p<0.02) in anti-210 ischemic muscles.
Conclusions: miR-210 stimulates angiogenesis in response to acute ischemia.
Author Disclosures: B. Maimone: None. G. Zaccagnini: None. C. Voellenkle: None. F. Martelli: None.
- © 2016 by American Heart Association, Inc.