Diagnosis and treatment of early renal disease in patients with type 2 diabetes mellitus: what are the clinical needs?

Targeting heme oxygenase-1 in early diabetic nephropathy in streptozotocin-induced diabetic rats

Diabetic nephropathy (DN) is one of the most common microvascular diabetic complications. This study was designed to evaluate the possible protective effect and underlying mechanisms of HO-1 induction in streptozotocin (STZ)-induced early DN in rats. The diabetic rats were divided into three groups: STZ-diabetic, cobalt protoporphyrin (CoPP)-treated diabetic, and zinc protoporphyrin IX (ZnPP)-treated diabetic groups. Compared to the STZ-diabetic group, CoPP-induced HO-1 upregulation improved the diabetic state and renal functional parameters, suppressed the renal proinflammatory marker, NF-κB, abrogated the elevated renal hydroxyprolin, and decreased the enhanced renal nicotinamide adenine dinucleotide phosphate oxidase activity with parallel reduction of urinary oxidative stress markers. On the contrary, treatment with ZnPP abrogated HO-1 levels, aggravated the diabetic condition with further increases in renal oxidative stress, fibrotic and inflammatory markers, and exacerbated renal dysfunction in diabetic animals. These findings suggest that the reduced diabetic renal injury upon HO-1 induction implicates the role of HO-1 induction as a potential treatment for DN.

Potential diagnostic biomarkers for chronic kidney disease of unknown etiology (CKDu) in Sri Lanka: a pilot study

Background

In Sri Lanka, there exists chronic kidney disease of both known (CKD) and unknown etiologies (CKDu). Identification of novel biomarkers that are customized to the specific causative factors would lead to early diagnosis and clearer prognosis of the diseases. This study aimed to find genetic biomarkers in blood to distinguish and identify CKDu from CKD as well as healthy populations from CKDu endemic and non-endemic areas of Sri Lanka.

Methods

The expression patterns of a selected panel of 12 potential genetic biomarkers were analyzed in blood using RT-qPCR. Fold changes of gene expressions in early and late stages of CKD and CKDu patients, and an apparently healthy population of a CKDu endemic area, Girandurukotte (GH) were calculated relative to apparently healthy volunteers from a CKDu non-endemic area, Kandy (KH) of Sri Lanka, using the comparative CT method.

Results

Significant differences were observed between KH and early stage CKDu for both the insulin-like growth factor binding protein 1 (IGFBP1; p = 0.012) and kidney injury molecule-1 (KIM1; p = 0.003) genes, and KH and late stage CKD and CKDu for the glutathione-S-transferase mu 1 (GSTM1; p < 0.05) gene. IGFBP1 and KIM1 genes showed significant difference between the early and late stage CKDu (p < 0.01). The glutamate cysteine ligase catalytic subunit (GCLC) gene had significantly different expression between KH and all the other study groups (p < 0.01). The GH group was significantly different from the KH group for the oxidative stress related genes, G6PD, GCLC and GSTM1 (p < 0.01), and also the KIM1 gene (p = 0.003). IGFBP1, insulin-like growth factor binding protein 3 (IGFBP3), fibronectin 1 (FN1) and KIM1 showed significant correlations with serum creatinine, and IGFBP1, KIM1 and kallikrein 1 (KLK1) with eGFR (p < 0.05).

Conclusion

A panel consisting of IGFBP1, KIM1, GCLC and GSTM1 genes could be used in combination for early screening of CKDu, whereas these genes in addition with FN1, IGFBP3 and KLK1 could be used to monitor progression of CKDu. The regulation of these genes has to be studied on larger populations to validate their efficiency for further clinical use.

Pathological Effects of Exosomes in Mediating Diabetic Cardiomyopathy

Diabetic subjects are at risk of developing cardiovascular disease, which accounts for 60-80% of diabetes-related mortality. Atherosclerosis is still considered as a leading cause of heart failure in diabetic patients, but it could also be an intrinsic and long-term effect of contractile cardiac cells malfunction, known as diabetic cardiomyopathy (DCM). Pathologically, this cardiac dysfunction is manifested by inflammation, apoptosis, fibrosis, hypertrophy and altered cardiomyocytes metabolism. However, the underlying molecular mechanisms of DCM pathophysiology are not clearly understood. Recent and several studies have suggested that exosomes are contributed to the regulation of cell-to-cell communication. Therefore, their in-depth investigation can interpret the complex pathophysiology of DCM. Structurally, exosomes are membrane-bounded vesicles (10-200 nm in diameter), which are actively released from all types of cells and detected in all biological fluids. They carry a wide array of bioactive molecules, including mRNAs, none-coding RNAs (e.g., microRNAs, lncRNAs, circRNAs, etc), proteins and lipids. Importantly, the abundance and nature of loaded molecules inside exosomes fluctuate with cell types and pathological conditions. This chapter summarizes currently available studies on the exosomes' role in the regulation of diabetic cardiomyopathy. Specifically, the advances on the pathological effects of exosomes in diabetic cardiomyopathy as well as the therapeutic potentials and perspectives are also discussed.

Proteomic prediction and Renin angiotensin aldosterone system Inhibition prevention Of early diabetic nephRopathy in TYpe 2 diabetic patients with normoalbuminuria (PRIORITY): essential study design and rationale of a randomised clinical multicentre trial

INTRODUCTION

Diabetes mellitus affects 9% of the European population and accounts for 15% of healthcare expenditure, in particular, due to excess costs related to complications. Clinical trials aiming for earlier prevention of diabetic nephropathy by renin angiotensin system blocking treatment in normoalbumuric patients have given mixed results. This might reflect that the large fraction of normoalbuminuric patients are not at risk of progression, thereby reducing power in previous studies. A specific risk classifier based on urinary proteomics (chronic kidney disease (CKD)273) has been shown to identify normoalbuminuric diabetic patients who later progressed to overt kidney disease, and may hold the potential for selection of high-risk patients for early intervention. Combining the ability of CKD273 to identify patients at highest risk of progression with prescription of preventive aldosterone blockade only to this high-risk population will increase power. We aim to confirm performance of CKD273 in a prospective multicentre clinical trial and test the ability of spironolactone to delay progression of early diabetic nephropathy.

METHODS AND ANALYSIS

Investigator-initiated, prospective multicentre clinical trial, with randomised double-masked placebo-controlled intervention and a prospective observational study. We aim to include 3280 type 2 diabetic participants with normoalbuminuria. The CKD273 classifier will be assessed in all participants. Participants with high-risk pattern are randomised to treatment with spironolactone 25 mg once daily, or placebo, whereas, those with low-risk pattern will be observed without intervention other than standard of care. Treatment or observational period is 3 years.The primary endpoint is development of confirmed microalbuminuria in 2 of 3 first morning voids urine samples.

ETHICS AND DISSEMINATION

The study will be conducted under International Conference on Harmonisation - Good clinical practice (ICH-GCP) requirements, ethical principles of Declaration of Helsinki and national laws. This first new biomarker-directed intervention trial aiming at primary prevention of diabetic nephropathy may pave the way for personalised medicine approaches in treatment of diabetes complications.

TRIAL REGISTRATION NUMBER

NCT02040441; Pre-results.

Diabetic nephropathy: What does the future hold?

The consensus management of diabetic nephropathy (DN) in 2015 involves good control of glycaemia, dyslipidaemia and blood pressure (BP). Blockade of the renin-angiotensin-aldosterone system using angiotensin-converting enzyme inhibitors, angiotensin-2 receptor blockers or mineralocorticoid inhibitors are key therapeutic approaches, shown to be beneficial once overt nephropathy is manifest, as either, or both, of albuminuria and loss of glomerular filtration rate. Some significant additional clinical benefits in slowing the progression of DN was reported from the Remission clinic experience, where simultaneous intensive control of BP, tight glycaemic control, weight loss, exercise and smoking cessation were prioritised in the management of DN. This has not proved possible to translate to more conventional clinical settings. This review briefly looks over the history and limitations of current therapy from landmark papers and expert reviews, and following an extensive PubMed search identifies the most promising clinical biomarkers (both established and proposed). Many challenges need to be addressed urgently as in order to obtain novel therapies in the clinic; we also need to examine what we mean by remission, stability and progression of DN in the modern era.