Protective effect of 3-hydroxybutyrate against endoplasmic reticulum stress-associated vascular endothelial cell damage induced by low glucose exposure

Abstract

Aims/HypothesisThe aim of this study was to elucidate the mechanism by which severe hypoglycemia accelerates vascular complications. Furthermore, we assessed the possible protective effect of ketone bodies against the endothelial cell damage caused by glucose deficiency.MethodsHuman umbilical vein endothelial cells (HUVECs) were cultured at a glucose level of either 0.56 or 5.6 mmol/L with or without 3-hydroxybutyrate (3-HB) supplementation. Cell viability was assessed with a CCK-8 assay and a lactate dehydrogenase (LDH) release assay. The activity of caspases was measured using fluorogenic substrates. The expression of genes associated with endothelial cell function and endoplasmic reticulum (ER) stress was evaluated by real-time quantitative PCR. Protein levels of ER stress-related molecules were assessed by Western blotting.ResultsCulture of HUVECs in low-glucose medium for 24 or 48 h resulted in reduction of cell viability accompanied by activation of caspase-3/7 and caspase-8. The addition of a pan caspase inhibitor attenuated the cell death. After incubation in the low-glucose medium, we found reduced mRNA and protein levels of endothelial nitric oxide synthase. ER stress responses mediated by phosphorylation of protein kinase RNA-like ER kinase (PERK) and cleavage of activating transcription factor 6 (ATF6) were augmented, but X-box binding protein 1 (Xbp1) splicing was reduced. Most of these responses to glucose deficiency were significantly attenuated by supplementation with 3-HB.Conclusions/InterpretationThese observations showed that exposure to low glucose induces ER stress, caspase activation, endothelial cell dysfunction and cell death. The beneficial effects of 3-HB shown in this study suggest that hypoketonemic severe hypoglycemia induced by insulin injections or insulin secretagogue administration may be more harmful than hyperketonemic severe hypoglycemia.

Exogenous ketosis elevates circulating erythropoietin and stimulates muscular angiogenesis during endurance training overload

“…This is of primary importance as exercise‐induced angiogenesis is mainly controlled by VEGF (Gorski & De Bock, 2019). Addition of βHB in the micromolar range (1–10 mM) has also been shown to increase endothelial nitric oxide synthase (eNOS), a downstream factor of VEGF, in human endothelial cells during low‐glucose‐induced endothelial cell damage (Soejima et al., 2018). Furthermore, treatment of cardiac endothelial cells with both the ketone bodies βHB and AcAc directly promoted cell proliferation and sprouting capacity in vitro (Weis et al., 2022).…”

Effect of A Very Low-Calorie Ketogenic Diet on Food and Alcohol Cravings, Physical and Sexual Activity, Sleep Disturbances, and Quality of Life in Obese Patients

“…However, it was evidenced that a VLCK diet is safe because it does not modify the acid-base equilibrium [ 18 ]. In fact, it has been proposed that the ketone body, β-hydroxy-butyrate (β-OHB) has several beneficial effects on metabolism [ 19 ] and psychological functions [ 20 , 21 ]. Nevertheless, a scarcity of studies has evaluated the effect of a VLCK diet combined with physical activity, on potential improvement in the psychological conditions and well-being of treated overweight/obese patients.…”

A comparative study between olive oil and corn oil on oxidative metabolism

“…However, this response could be beneficial since a possible protective effect of these ketone bodies against the cell damage caused by this glucose metabolism dysfunction has been recently demonstrated. 79…”

“…However, this response could be beneficial since a possible protective effect of these ketone bodies against the cell damage caused by this glucose metabolism dysfunction has been recently demonstrated. 79 Regarding cell membranes, LDH is rapidly released when the plasma membrane is damaged, a key feature of cells undergoing apoptosis, necrosis, and other forms of cellular damage. 80 This would mean that, in the hepatocytes treated with corn oil, the release of LDH is greater (Fig.…”