Background: Diabetic heart disease may eventually lead to heart failure, a leading cause of mortality in diabetic individuals. The lack of effective treatments for diabetes-induced heart failure may result from a failure to address the underlying pathological processes, including chronic, low-grade inflammation. Previous studies have reported that lipoxin A (LXA), known to promote resolution of inflammation, attenuates diabetes-induced atherosclerosis, but its impact on diabetic hearts has not been sought.
View Article and Find Full Text PDFDiabetic Kidney Disease (DKD) is a significant complication of diabetes and primary cause of end-stage renal disease globally. The exact mechanisms underlying DKD remain poorly understood, but multiple factors, including the renin-angiotensin-aldosterone system (RAAS), play a key role in its progression. Aldosterone, a mineralocorticoid steroid hormone, is one of the key components of RAAS and a potential mediator of renal damage and inflammation in DKD.
View Article and Find Full Text PDFY-box-binding protein 1 is a well-described and important regulator of gene transcription, which is linked to various pathologic conditions, including inflammation and fibrosis of the kidney. The identification of a novel and protective crosstalk pathway between podocytes and tubular cells in the kidney with Y-box-binding protein 1 acting as a paracrine messenger sheds new light and provides novel opportunities for renoprotection.
View Article and Find Full Text PDFGlucagon like peptide-1 (GLP-1) is a hormone produced and released by cells of the gastrointestinal tract following meal ingestion. GLP-1 receptor agonists (GLP-1RA) exhibit kidney-protective actions through poorly understood mechanisms. Here we interrogated whether the receptor for advanced glycation end products (RAGE) plays a role in mediating the actions of GLP-1 on inflammation and diabetic kidney disease.
View Article and Find Full Text PDFDiabetes mellitus (DM) is an independent risk factor for micro- and macrovascular complications such as nephropathy and atherosclerosis respectively, which are the major causes of premature morbidity and mortality in Type 1 and Type 2 diabetic patients. Endothelial dysfunction is the critical first step of vascular disease and is characterized by reduced bioavailability of the essential endothelial vasodilator, nitric oxide (NO), coupled with an elevation in inflammation and oxidative stress. A novel pathway to bolster NO activity is to upregulate soluble guanylate cyclase (sGC), an enzyme responsible for mediating the protective actions of NO.
View Article and Find Full Text PDFObesity, diabetes mellitus, hypertension and cardiovascular disease are risk factors for chronic kidney disease (CKD) and kidney failure. Chronic, low-grade inflammation is recognized as a major pathogenic mechanism that underlies the association between CKD and obesity, impaired glucose tolerance, insulin resistance and diabetes, through interaction between resident and/or circulating immune cells with parenchymal cells. Thus, considerable interest exists in approaches that target inflammation as a strategy to manage CKD.
View Article and Find Full Text PDFFailure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing synthetic-LXA-mimetics (QNX-sLXms).
View Article and Find Full Text PDFBackground: The nicotinamide adenine dinucleotide phosphate oxidase isoform 4 (Nox4) mediates reactive oxygen species (ROS) production and renal fibrosis in diabetic kidney disease (DKD) at the level of the podocyte. However, the mitochondrial localization of Nox4 and its role as a mitochondrial bioenergetic sensor has recently been reported. Whether Nox4 drives pathology in DKD within the proximal tubular compartment, which is densely packed with mitochondria, is not yet known.
View Article and Find Full Text PDFDiabetic kidney disease (DKD) is a major health problem and one of the leading causes of end-stage renal disease worldwide. Despite recent advances, there exists an urgent need for the development of new treatments for DKD. DKD is characterized by the excessive synthesis and deposition of extracellular matrix proteins in glomeruli and the tubulointerstitium, ultimately leading to glomerulosclerosis as well as interstitial fibrosis.
View Article and Find Full Text PDFSeveral studies have shown that failure to resolve inflammation may contribute to the progression of many chronic inflammatory disorders. It has been suggested targeting the resolution of inflammation might be a novel therapeutic approach for chronic inflammatory diseases, including inflammatory bowel disease, diabetic complications, and cardiometabolic disease. Lipoxins [LXs] are a class of endogenously generated mediators that promote the resolution of inflammation.
View Article and Find Full Text PDFDiabetes mellitus (DM) is an important metabolic disorder characterized by persistent hyperglycemia resulting from inadequate production and secretion of insulin, impaired insulin action, or a combination of both. Genetic disorders and insulin receptor disorders, environmental factors, lifestyle choices and toxins are key factors that contribute to DM. While it is often referred to as a metabolic disorder, modern lifestyle choices and nutrient excess induce a state of systemic chronic inflammation that results in the increased production and secretion of inflammatory cytokines that contribute to DM.
View Article and Find Full Text PDFTransforming growth factor-beta (TGF-β1) plays an important regulatory role in the progression of chronic kidney failure. Further, damage to kidney glomerular mesangial cells is central to the progression of diabetic nephropathy. The aim of this study was to explore the genetic associations between mRNA, microRNA, and epigenetics in mesangial cells in response to TGF-β1.
View Article and Find Full Text PDFIncreasing evidence points to the fact that defects in the resolution of inflammatory pathways predisposes individuals to the development of chronic inflammatory diseases, including diabetic complications such as accelerated atherosclerosis. The resolution of inflammation is dynamically regulated by the production of endogenous modulators of inflammation, including lipoxin A4 (LXA). Here, we explored the therapeutic potential of LXA and a synthetic LX analog (Benzo-LXA) to modulate diabetic complications in the streptozotocin-induced diabetic ApoE mouse and in human carotid plaque tissue ex vivo.
View Article and Find Full Text PDFThe failure of spontaneous resolution underlies chronic inflammatory conditions, including microvascular complications of diabetes such as diabetic kidney disease. The identification of endogenously generated molecules that promote the physiologic resolution of inflammation suggests that these bioactions may have therapeutic potential in the context of chronic inflammation. Lipoxins (LXs) are lipid mediators that promote the resolution of inflammation.
View Article and Find Full Text PDFSignaling via the receptor of advanced glycation end products (RAGE)-though complex and not fully elucidated in the setting of diabetes-is considered a key injurious pathway in the development of diabetic nephropathy (DN). We report here that RAGE deletion resulted in increased expression of fibrotic markers (collagen I and IV, fibronectin) and the inflammatory marker MCP-1 in primary mouse mesangial cells (MCs) and in kidney cortex. RNA sequencing analysis in MCs from RAGE and wild-type mice confirmed these observations.
View Article and Find Full Text PDFThe contribution of environmental factors to pancreatic islet damage in type 1 diabetes remains poorly understood. In this study, we crossed mice susceptible to type 1 diabetes, where parental male (CD8 T cells specific for IGRP; NOD8.3) and female (NOD/ShiLt) mice were randomized to a diet either low or high in AGE content and maintained on this diet throughout pregnancy and lactation.
View Article and Find Full Text PDFThe protein oligosaccharyltransferase-48 (OST48) is integral to protein N-glycosylation in the endoplasmic reticulum (ER) but is also postulated to act as a membrane localised clearance receptor for advanced glycation end-products (AGE). Hepatic ER stress and AGE accumulation are each implicated in liver injury. Hence the objective of this study was to increase the expression of OST48 and examine the effects on hepatic function and structure.
View Article and Find Full Text PDFThe let-7 miRNA family plays a key role in modulating inflammatory responses. Vascular smooth muscle cell (SMC) proliferation and endothelial cell (EC) dysfunction are critical in the pathogenesis of atherosclerosis, including in the setting of diabetes. Here we report that let-7 levels are decreased in diabetic human carotid plaques and in a model of diabetes-associated atherosclerosis, the diabetic ApoE mouse.
View Article and Find Full Text PDFThe cytokine transforming growth factor (TGF)-β1 plays a central role in diabetic nephropathy (DN) with data implicating the miRNA (miR) miR-21 as a key modulator of its prosclerotic actions. In the present study, we demonstrate data indicating that miR-21 up-regulation positively correlates with the severity of fibrosis and rate of decline in renal function in human DN. Furthermore, concomitant analyses of various models of fibrotic renal disease and experimental DN, confirm tubular miR-21 up-regulation.
View Article and Find Full Text PDFIn recent years, several studies have reported dysregulation of microRNA expression in disease with a growing interest focussed on targeting microRNAs as a novel therapy for human disease. This is especially true in diabetic nephropathy where the expression of several microRNAs is dysregulated, contributing to the increased expression and accumulation of extracellular matrix proteins and increased pro-fibrotic signalling, ultimately resulting in renal fibrosis. The development of various techniques and microRNA reagents has enabled work to progress very rapidly in this area.
View Article and Find Full Text PDFBackground: Advanced glycation end products (AGE)-receptor for AGE (RAGE) axis and renin-angiotensin system (RAS) play a role in diabetic nephropathy (DN). Matrix metalloproteinase-2 (MMP-2) activation also contributes to DN. However, the pathological interaction among AGE-RAGE, RAS and MMP-2 in DN remains unknown.
View Article and Find Full Text PDFDiabetes is among the most common causes of end-stage renal disease, although its pathophysiology is incompletely understood. We performed next-generation sequencing-based transcriptome analysis of renal gene expression changes in the OVE26 murine model of diabetes (age 15 weeks), relative to non-diabetic control, in the presence and absence of short-term (seven-day) treatment with the angiotensin receptor blocker, losartan (n = 3-6 biological replicates per condition). We detected 1438 statistically significant changes in gene expression across conditions.
View Article and Find Full Text PDFMicroRNAs (miRNA) are a novel class of small, noncoding RNA molecules that have gained the attention of many researchers in recent years due to their ability to posttranscriptionally regulate the expression of families of genes simultaneously. Their role in normal physiology and pathobiology is intriguing and their regulation in normal and disease states is fascinating. That the cells can return to a state of homeostasis when these small molecules are perturbed is truly remarkable given the multiple cellular targets of each miRNA and that many mRNAs are targeted by multiple miRNAs.
View Article and Find Full Text PDFCurr Opin Nephrol Hypertens
January 2014
Purpose Of Review: Several factors are now known to contribute to the development and progression of nephropathy, particularly in diabetes. In recent times, there has been surge of interest in the role of small noncoding RNA, with several reports focusing on the effects of microRNAs on their target genes that are of relevance to nephropathy. This review focuses on recent progress in this field.
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