Abstract
Purpose:
Retinal fibrosis is a common complication of proliferative diabetic retinopathy (PDR) and is characterized by increased proliferation and contraction of cells, as well as the accumulation of extracellular matrix. In the pathogenesis of diabetic retinopathy, pericytes play a central role, and their transformation into myofibroblasts, a cell type involved in fibrotic disorders, has been described. A hallmark of this transformation is the increased expression of α-smooth muscle actin (α-SMA), an actin isoform important for cellular contractility. This study investigates whether Axitinib, a second generation multi-kinase inhibitor, can inhibit pericyte/myofibroblast transformation, proliferation and contraction in vitro.
Methods:
Human Pericytes from Placenta (hPC-PL) were exposed to Axtinib concentrations ranging from 0,1pg/ml to 0,1mg/ml to assess viability (MTT assay), induction of cell death (live/dead staining) and proliferation (MTT assay). The inhibitory effect of Axitinib on cellular contractility was investigated by a collagen contraction assay. Immunocytochemistry for α-SMA was performed after pretreatment with 1ng/ml TGFβ2.
Results:
Up to 10µg/ml Axitinib showed no effect on viability and induction of cell death. 1µg/ml Axitinib reduced proliferation by 13%, a concentration of 2.5µg/ml by 41%. 2.5µg/ml Axitinib inhibited cellular contraction by 24%. After pretreatment with TGFβ2, hPC-PL expression of α-SMA was significantly reduced by Axitinib.
Conclusions:
In this in-vitro study Axitinib inhibited pericyte contraction and TGFβ2-induced α-SMA-overexpression, two hallmarks of pericyte/myofibroblast transformation in retinal fibrosis. With its additional antiproliferative effects, Axitinib may offer properties as anti-fibrotic treatment in retinal vascular disease in vivo.
Keywords: 499 diabetic retinopathy •
688 retina •
765 wound healing