Dapagliflozin Reduces Apoptosis of Diabetic Retina and Human Retinal Microvascular Endothelial Cells Through ERK1/2/cPLA2/AA/ROS Pathway Independent of Hypoglycemic

Abstract

Introduction: It is known that the metabolic disorder caused by high glucose is one of pathogenesis in diabetic retinopathy (DR), the leading cause of blindness, due to the main pathological change of apoptosis of endothelial cells (ECs). In previous studies, the potential impact of sodium glucose cotransporter-2 (SGLT-2), whose inhibitors slow the progression of DR, has not been elucidated. The purpose of the presented study was to explore the effect of SGLT-2 inhibitors dapagliflozin (DAPA) on apoptosis of diabetic mice retina and human retinal microvascular endothelial cells (HRMECs), examine the effects of dapagliflozin on HRMECs metabolism, and explore the molecular processes that affect DR.Methods and Results: The eyeballs of male streptozotocin (STZ)-induced diabetic C57BL/6N mice were evaluated. C57BL/6N mice were divided into control group (CON), diabetic untreated group (DM), diabetic dapagliflozin treatment group (DM + DAPA) and diabetic insulin treatment group (DM + INS). Hematoxylin-Eosin (HE) staining was performed to observe the pathological structure of the mice retina, and TUNEL staining to detect apoptosis of mice retinal cells. In vitro, DCFH-DA and western blot (WB) were used to evaluate ROS, Bcl-2, BAX, cleaved-caspase 3 in HRMECs and metabolomics detected the effect of dapagliflozin on the metabolism of HRMECs. And then, we performed correlation analysis and verification functions for significantly different metabolites. In vivo, dapagliflozin reduced the apoptosis of diabetic mice retina independently of hypoglycemic. In vitro, SGLT-2 protein was expressed on HRMECs. Dapagliflozin reduced the level of ROS caused by high glucose, decreased the expression of cleaved-caspase3 and the ratio of BAX/Bcl-2. Metabolomics results showed that dapagliflozin did not affect the intracellular glucose level. Compared with the high glucose group, dapagliflozin reduced the production of arachidonic acid (AA) and inhibited the phosphorylation of ERK1/2, therefore, reducing the phosphorylation of cPLA2, which is a key enzyme for arachidonic acid release.Conclusion: Collectively, results unearthed for the first time that dapagliflozin reduced apoptosis of retina induced by DM whether in vivo or in vitro. Dapagliflozin did not affect the glucose uptake while mitigated intracellular arachidonic acid in HRMECs. Dapagliflozin alleviated HRMECs apoptosis induced by high glucose through ERK/1/2/cPLA2/AA/ROS pathway.

Determining the Role of SGLT2 Inhibition with Dapagliflozin in the Development of Diabetic Retinopathy

“…However, there is limited data from either animal models or clinical trials regarding the effects of SGLT2 inhibition on DR in type 1 diabetes [16]. In addition to our findings, a single study [35] has reported the protective effects of the SGLT2 inhibitor DAPA on DR in the setting of type 1 diabetes. Interestingly, our group is the first to uncover DAPA mediated reductions in retinal microvascular lesions in type 1 diabetic mice.…”

Dapagliflozin induces apoptosis by downregulating cFILPL and increasing cFILPS instability in Caki‑1 cells

“…These data suggest that dapagliflozin-mediated apoptosis is independent of ROS generation. However, recent studies have shown that dapagliflozin decreases ROS production (43)(44)(45). Consistent with the present study, dapagliflozin appears to be a feasible option for reducing ROS production.…”

Role of Sodium-Glucose Co-Transporter 2 Inhibitors in the Regulation of Inflammatory Processes in Animal Models

“…Although the first interest in SGLT2i was their glucose-lowering capacity, lately there have been described pleiotropic effects of SGLT2i in a wide range of targets throughout the body ( Figure 2 ). Using different experimental approaches and in different scenarios, SGLT2i have been shown to participate in the regulation of osmotic natriuresis and diuresis [ 103 , 104 ], hypertension [ 105 ], glucagon [ 106 , 107 ] and energy metabolism [ 108 , 109 , 110 , 111 , 112 ], mitochondrial function and biogenesis [ 113 , 114 , 115 , 116 , 117 , 118 ], autophagy [ 112 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ], oxidative stress [ 46 , 123 , 126 , 127 , 128 , 129 ], fibrosis [ 46 , 130 , 131 , 132 , 133 ], apoptosis [ 122 , 128 , 134 , 135 , 136 , 137 , 138 , 139 ], endoplasmic reticulum stress [ 124 , 139 , 140 , 141 , 142 , 143 ], or inflammation [ 120 ,…”