Purchase this article with an account.
Salome Murinello, Peter D Westenskow, Carli M Wittgrove, Yoshihiko Usui, Stacey K Moreno, Edith Aguilar, Martin Friedlander; Targeting miR30a prevents pathological retinal angiogenesis by enhancing CCL2-dependent macrophage recruitment. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):45.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The vast majority of blinding diseases are associated with abnormal angiogenesis. MicroRNA 30a (miR30a) is a potent regulator of developmental and pathological angiogenesis. While originally identified in a high-throughput screen as a modulator of the VEGF/Ras/ERK signalling pathway, we show here that it can potently regulate the chemokine CCL2. Therefore we hypothesized that miR30a exerts additional effects on the retinal vasculature through CCL2-dependent recruitment of macrophages/microglia and miR30a-induced phagocytosis.
We examined the effects of targeting miR30a in multiple murine models of normal and pathological angiogenesis including oxygen-induced retinopathy (OIR) and very low density lipoprotein receptor knock-out (VLDLR-/-) mice. We performed intravitreous injections of anti-miR30a or scramble (control) miRs, and collected the tissues 2h through 48h afterwards. Macrophage/microglia recruitment was studied by CD11b immunoreactivity in retinal flat-mounts. qPCR, ELISA and in situ hybridization techniques were used to determine the spatial and temporal expression patterns of CCL2 mRNA and protein. The effect of anti-miR30a on phagocytic function was determined in vitro using bone-marrow derived macrophages (BMDMs).
Injection of anti-miR30a resulted in accelerated hyaloid regression in wild-type mice and significantly prevented neovascularization in OIR and VLDLR-/- mice. In all studies, retinal CCL2 mRNA and protein expression peaked at 6 hours after anti-miR30a injections, concomitant with an increase in CD11b+ macrophage/microglia infiltration that persisted until at least 48 hours post-injection. In situ hybridization analyses revealed that CCL2 was produced by retinal macrophages and neurons. Finally, BMDMs stimulated with anti-miR30a had increased phagocytic function as seen by increased uptake of fluorescent beads.
Several studies have suggested a detrimental role for CCL2 in the progression of angiogenesis. Here we show that anti-miR30a mediated CCL2 upregulation enhances macrophage/microglia recruitment and phagocytic function. It also accelerates regression of excessive vascular networks and prevents pathological angiogenesis. The results of this study demonstrate that anti-miR30a-based therapies may be effective for treating human neovascular eye diseases by targeting non-VEGF driven pathways.
This PDF is available to Subscribers Only