25-hydroxyvitamin D3 inhibits oxidative stress and ferroptosis in retinal microvascular endothelial cells induced by high glucose through down-regulation of miR-93

Abstract

Background The decrease of vitamin D plays a critical role in diabetes mellitus (DM)-induced oxidative stress and vascular endothelial injury. Therefore, we investigated the effect and mechanism of 25-hydroxyvitamin D3 (25 (OH) D3) on oxidative stress and ferroptosis induced by high glucose in human retinal microvascular endothelial cells (hRMVECs). And the objective of this paper was to propose a new strategy for the prevention and treatment of diabetic retinopathy (DR). Methods First, hRMVECs were transfected with mimics NC or miR-93. After that, cells were treated with 100 nM / 500 nM 25 (OH) D3 and then cultured in a high glucose (30 mM) environment. Subsequently, qRT-PCR was employed to detect the expression level of miR-93; CCK-8 for the proliferation of cells in each group; biochemical tests for the level of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), reduced glutathione (GSH) and ferrous ion (Fe2+); and Western blot for the expression of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and SLC7A11). Results Under a high glucose environment, 25 (OH) D3 at 100 nM/500 nM could significantly promote the proliferation of hRMVECs, remarkably decrease the level of intracellular ROS/MDA, and up-regulate the level of GSH. Besides, 25 (OH) D3 greatly reduced Fe2+ level in the cells while increased protein level of GPX4 and SLC7A11. Subsequently, we found that high glucose induced miR-93 expression, while 25 (OH) D3 markedly decreased high glucose-induced miR-93 overexpression. Furthermore, overexpression of miR-93 inhibited the functions of 25 (OH) D3 by activating ROS (ROS and MDA were up-regulated while GSH was down-regulated) and inducing Fe2+ (Fe2+ level was up-regulated while GPX4 and SLC7A11 level was down-regulated) in cells. Conclusion 25 (OH) D3 may inhibit oxidative stress and ferroptosis in hRMVECs induced by high glucose via down-regulation of miR-93.

The role of oxidative stress in diabetes mellitus-induced vascular endothelial dysfunction

“…Knocking out circ-UBAP2 in the miR-589-5p/EGR1 axis alleviates high glucose-induced oxidative stress and vascular dysfunction in human retinal microvascular endothelial cells (HRMECs) by increasing superoxide dismutase (SOD) and glutathione peroxidase activities and nuclear factor erythroid 2-related factor 2 (Nrf2), HO-1, and SOD-1 expression, which provides a promising therapeutic target for diabetic retinopathy [ 88 ]. Besides, miR-93 suppression induced by 25-dihydroxyvitamin D3 inhibits the high glucose-induced overproduction of ROS, MDA and ferroptosis in HRMECs [ 89 ].…”

The impact of vitamin D on the etiopathogenesis and the progression of type 1 and type 2 diabetes in children and adults

“…High glucose-induced upregulation of pro-inflammatory cytokines can lead to the destruction of the blood-retinal barrier (BRB), cell death, and angiogenesis ( 22 , 25 ). Supplementing vitamin D can protect retinal epithelial cells from high glucose-induced oxidative stress, inflammation and ferroptosis which may be one of the mechanisms by which vitamin D prevents the progression of diabetic retinopathy ( 28 , 29 ).…”

Effects of vitamin family members on insulin resistance and diabetes complications

“…Neuroprotective effects are exerted through the SIRT1/nrf-2/NF-kB signaling pathway[ 24 ]. 25(OH)D3 may inhibit oxidative stress in human retinal microvascular endothelial cells induced by high glucose-mediated miR-93 down-regulation[ 25 ]. Supplementation with vitamin D also improves neuropathy[ 26 ], which might be related to its regulation of neurotrophic factor levels and neuronal calcium homeostasis.…”