Kaempferol inhibited VEGF and PGF expression and in vitro angiogenesis of HRECs under diabetic-like environment

Abstract

Diabetic retinopathy (DR) is one of the common and specific microvascular complications of diabetes. This study aimed to investigate the anti-angiogenic effect of kaempferol and explore its underlying molecular mechanisms. The mRNA expression level of vascular endothelial growth factor (VEGF) and placenta growth factor (PGF) and the concentrations of secreted VEGF and PGF were measured by qTR-PCR and ELISA assay, respectively. Human retinal endothelial cells (HRECs) proliferation, migration, and sprouting were measured by CCK-8 and transwell, scratching wound, and tube formation assays, respectively. Protein levels were determined by western blot. High glucose (25 mM) increased the mRNA expression levels of VEGF and PGF as well as the concentrations of secreted VEGF and PGF in HRECs, which can be antagonized by kaempferol (25 µM). Kaempferol (5-25 µM) significantly suppressed cell proliferation, migration, migration distance and sprouting of HRECs under high glucose condition. The anti-angiogenic effect of kaempferol was mediated via downregulating the expression of PI3K and inhibiting the activation of Erk1/2, Src, and Akt1. This study indicates that kaempferol suppressed angiogenesis of HRECs via targeting VEGF and PGF to inhibit the activation of Src-Akt1-Erk1/2 signaling pathway. The results suggest that kaempferol may be a potential drug for better management of DR.

Chemo‐preventive and therapeutic effect of the dietary flavonoid kaempferol: A comprehensive review

“…Administration of kaempferol at the rate of 5–25 μM, under high‐glucose conditions, markedly inhibited cell proliferation, migration distance, and growth of HRECs. Furthermore, kaempferol suppressed the activation of Src, Erk1/2, and Akt1 and downregulated the expression of PI3K (Xu, Zhao, Peng, Xie, & Liu, ). Varshney and coworkers recently studied the cytoprotective effect of kaempferol against palmitic acid‐induced pancreatic β‐cell death through modulation of autophagy via the AMPK/mTOR signaling pathway.…”

A Critical Analysis of the AvailableIn VitroandEx VivoMethods to Study Retinal Angiogenesis

“…Some authors use both methods [ 74 , 75 , 126 ]. Although higher costs and more time are required, this approach allows us to compare both results, overtaking some limitations of each one.…”

“…The form WST-8 combines the high stability of WST-1 with the high sensitivity of WST-3 [ 172 ]. WST assays are indeed the most used, and we can observe an increase in the WST-8 use instead of WST-1 over time: 15 works [ 57 , 74 , 88 , 91 , 98 , 100 , 102 , 107 , 108 , 110 , 112 , 121 , 173 , 174 ] used WST-8 since 2007, whereas only 6 studies [ 39 , 54 , 104 , 113 , 140 , 175 ] applied WST-1, having been the last time in 2014. Contrary to tetrazolium salts, only two articles [ 70 , 105 ] used alamar blue compound to assess metabolic activity, which is surprising since alamar blue has been available for a long time and seems to offer many advantages over tetrazolium salts.…”

“…Actually, most of the found retinal explant protocols aimed at evaluating the toxicity of possible new drugs, some of which antiangiogenic, but they do not evaluate specifically angiogenesis. Instead, they evaluate retinal morphology [ 74 , 130 , 192 , 193 ] or perform electroretinograms [ 194 , 195 ] to assess functionality.…”

MicroRNA-214 Prevents Pulmonary Angiogenesis and Alveolarization in Rat Models with Bronchopulmonary Dysplasia via PlGF-Dependent STAT3 Signaling Pathway

“…MiR-214 can inhibit angiogenesis procession by suppressing Quaking and pro-angiogenic growth factor expression [37]. Through the depletion of PlGF, Kaempferol exerts suppressive effects on angiogenesis of human retinal endothelial cells [38]. Therefore, our studies evidenced that miR-214 overexpression could reduce the expression of pro-in ammatory factors, thus blocked pulmonary angiogenesis and alveolarization as well as inhibit cell apoptosis of lung epithelium in neonatal rats with BPD.…”