Midazolam Ameliorates Hyperglycemia-Induced Glomerular Endothelial Dysfunction by Inhibiting Transglutaminase 2 in Diabetes

Abstract

Midazolam is an anesthetic widely used for anxiolysis and sedation; however, to date, a possible role for midazolam in diabetic kidney disease remains unknown. Here, we investigated the effect of midazolam on hyperglycemia-induced glomerular endothelial dysfunction and elucidated its mechanism of action in kidneys of diabetic mice and human glomerular microvascular endothelial cells (HGECs). We found that, in diabetic mice, subcutaneous midazolam treatment for 6 weeks attenuated hyperglycemia-induced elevation in urine albumin/creatinine ratios. It also ameliorated hyperglycemia-induced adherens junction disruption and subsequent microvascular leakage in glomeruli of diabetic mice. In HGECs, midazolam suppressed high glucose-induced vascular endothelial-cadherin disruption and endothelial cell permeability via inhibition of intracellular Ca2+ elevation and subsequent generation of reactive oxygen species (ROS) and transglutaminase 2 (TGase2) activation. Notably, midazolam also suppressed hyperglycemia-induced ROS generation and TGase2 activation in glomeruli of diabetic mice and markedly improved pathological alterations in glomerular ultrastructure in these animals. Analysis of kidneys from diabetic Tgm2−/− mice further revealed that TGase2 played a critical role in microvascular leakage. Overall, our findings indicate that midazolam ameliorates hyperglycemia-induced glomerular endothelial dysfunction by inhibiting ROS-mediated activation of TGase2.

Simultaneous attenuation of hyperglycemic memory-induced retinal, pulmonary, and glomerular dysfunctions by proinsulin C-peptide in diabetes

“…Microvascular leakage in mouse retinas, lungs, and kidneys was measured as previously described [ 5 , 7 , 28 ]. Briefly, mice were deeply anesthetized, and 1.25 mg 500-kDa FITC-dextran (MilliporeSigma) was injected into the left ventricle and circulated for 5 min.…”

“…In situ TGase transamidating activity was measured by confocal microscopic assay as previously described [ 28 ]. Briefly, HRECs were treated with 1 mmol/L 5-(biotinamido)pentylamine for 1 h and fixed with 3.7% formaldehyde for 30 min.…”

Polymer-Based Delivery of Peptide Drugs to Treat Diabetes: Normalizing Hyperglycemia and Preventing Diabetic Complications

“…DN develops in 40% of type 2 diabetes patients and 30% of type 1 diabetes patients, with a peak incidence in 10-20 years after diagnosis of diabetes [45,47]. DN is characterized by a number of pathological changes of the kidney, including albuminuria, a progressive decrease in glomerular filtration rate, increased blood pressure, and renal fibrosis due to glomerular and tubular membrane thickening, increased expression of extracellular matrix, and microvascular dysfunction [48]. Microalbuminuria, which is now generally accepted as the first clinical indication of DN, is induced by interference of the glomerular filtration barrier due to microvascular dysfunction, glomerular basement membrane thickening, and foot process effacement of podocytes [49].…”

“…Chronic kidney disease is diagnosed by increased excretion of urinary albumin, decreased glomerular filtration rate, or other indications of kidney damage [50]. An alteration in glomerular microvascular permeability is a key pathogenic factor of diabetic kidney disease and is associated with microalbuminuria [48]. Glomerular endothelial cells interact with podocytes and mesangial cells via growth factors, including VEGF and transforming growth factor-β1, and glomerular microvascular dysfunction is associated with development and progression of DN [49,51].…”

“…Numerous efforts have been made to develop drugs targeting podocyte injury and renal fibrosis. Potential anti-fibrotic drugs have been reported in preclinical studies, including neutralizing antibodies against transforming growth factor-β1 and connective tissue growth factor; however, their effectiveness on DN has been limited [48,54]. Since the change in glomerular microvascular permeability is a pivotal pathogenic factor of diabetic kidney disease, renal fibrosis and glomerular microvascular dysfunction remain attractive targets in translational researches for the treatment of DN [48].…”