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Aims: Long noncoding RNAs (lncRNAs) play key roles in the pathophysiology of DKD involving actions of microRNAs (miRNAs). The aims of the study were to establish the involvement of selected lncRNAs in the epigenetic mechanisms of podocyte damage and tubular injury in DKD of type 2 diabetes mellitus (DM) patients in relation to a particular miRNAs profile. Methods: A total of 136 patients with type 2 DM and 25 healthy subjects were assessed in a cross-sectional study concerning urinary albumin: creatinine ratio (UACR), eGFR, biomarkers of podocyte damage (synaptopodin, podocalyxin) and of proximal tubule (PT) dysfunction (Kidney injury molecule-1-KIM-1, N-acetyl-D-glucosaminidase-NAG), urinary lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), nuclear-enriched abundant transcript 1 (NEAT1), myocardial infarction-associated transcript (MIAT), taurine-upregulated gene 1 (TUG1), urinary miRNA21, 124, 93, 29a. Results: Multivariable regression analysis showed that urinary lncMALAT1 correlated directly with urinary synaptopodin, podocalyxin, KIM-1, NAG, miRNA21, 124, UACR, and negatively with eGFR, miRNA93, 29a (p<0.0001; R 2 =0.727); urinary lncNEAT1 correlated directly with synaptopodin, KIM-1, NAG, miRNA21, 124, and negatively with eGFR, miRNA93, 29a (p<0.0001; R 2 =0.702); urinary lncMIAT correlated directly with miRNA93 and 29a, eGFR (p<0.0001; R 2 =0.671) and negatively with synaptopodin, KIM-1, NAG, UACR, miRNA21, 124 (p<0.0001; R 2 =0.654); urinary lncTUG1 correlated directly with eGFR, miRNA93, 29a, and negatively with synaptopodin, podocalyxin, NAG, miRNA21, 124 (p<0.0001; R 2 =0.748). Conclusions: In patients with type 2 DM lncRNAs exert either deleterious or protective functions within glomeruli and PT. LncRNAs may contribute to DKD through modulating miRNAs expression and activities. This observation holds true independently of albuminuria and DKD stage., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Aims: To evaluate if there is a link between inflammation (expressed by inflammatory cytokines) and the early stage of diabetic kidney disease (DKD), as shown by markers of podocyte damage and proximal tubular (PT) dysfunction., Methods: In this study were enrolled 117 type 2 DM patients (36-normoalbuminuria, 42-microalbuminuria, 39- macroalbuminuria), and 11 healthy subjects. Serum and urinary IL-1 alpha, IL-8, IL-18, urinary albumin:creatinine ratio (UACR), eGFR, biomarkers of podocyte damage (podocalyxin, synaptopodin, nephrin) and of PT dysfunction (KIM-1, NAG) were assessed., Results: In multivariable regression urinary Il-1 alpha correlated positively with podocalyxin and NAG (p < 0.0001, R 2 = 0.57); urinary IL-8 correlated directly with synaptopodin, NAG, nephrin, and KIM-1 (p < 0.0001, R 2  = 0.67); urinary IL-18 correlated directly with synaptopodin, NAG, and nephrin (p < 0.0001, R 2  = 0.59). Serum IL-1 alpha correlated positively with nephrin, synaptopodin, NAG (P < 0.0001, R 2  = 0.68); serum IL-8 correlated directly with synaptopodin and NAG (p < 0.0001, R 2  = 0.66); serum IL-18 correlated directly with NAG, KIM-1, and podocalyxin (p < 0.0001, R 2 =0.647)., Conclusions: Pro-inflammatory interleukins are associated with podocyte injury and PT dysfunction in early DKD. These could exert a key role in the pathogenesis of early DKD, before the development of albuminuria., (Copyright © 2019 Elsevier Inc. All rights reserved.)

MicroRNAs (miRNAs) are short non-coding RNA species that are important post-transcriptional regulators of gene expression. The aim of the study was to establish a potential explanation of podocyte damage and proximal tubule (PT) dysfunction induced by deregulated miRNAs expression in the course of type 2 diabetes mellitus (DM). A total of 68 patients with type 2 DM and 11 healthy subjects were enrolled in a cross-sectional study and assessed concerning urinary albumin:creatinine ratio (UACR), urinary N -acetyl-β-D-glucosamininidase (NAG), urinary kidney injury molecule-1, urinary nephrin, podocalyxin, synaptopodin, estimated glomerular filtration rate (eGFR), urinary miRNA21, miRNA124, and miRNA192. In univariable regression analysis, miRNA21, miRNA124, and miRNA192 correlated with urinary nephrin, synaptopodin, podocalyxin, NAG, KIM-1, UACR, and eGFR. Multivariable regression analysis yielded models in which miRNA192 correlated with synaptopodin, uNAG, and eGFR (R 2 =0.902; P<0.0001), miRNA124 correlated with synaptopodin, uNAG, UACR, and eGFR (R 2 =0.881; P<0.0001), whereas miRNA21 correlated with podocalyxin, uNAG, UACR, and eGFR (R 2 =0.882; P<0.0001). Urinary miRNA192 expression was downregulated, while urinary miRNA21 and miRNA124 expressions were upregulated. In patients with type 2 DM, there is an association between podocyte injury and PT dysfunction, and miRNA excretion, even in the normoalbuminuria stage. This observation documents a potential role of the urinary profiles of miRNA21, miRNA124, and miRNA192 in early DN. Despite their variability across the segments of the nephron, urinary miRNAs may be considered as a reliable tool for the identification of novel biomarkers in order to characterize the genetic pattern of podocyte damage and PT dysfunction in early DN of type 2 DM., Competing Interests: Competing interests: None declared., (© American Federation for Medical Research (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Aims: Detection of podocytes in the urine of patients with type 2 diabetes may indicate severe injury to the podocytes. In the course of type 2 diabetes the proximal tubule is involved in urinary albumin processing. We studied the significance of podocyturia in relation with proximal tubule dysfunction in type 2 diabetes., Methods: A total of 86 patients with type 2 diabetes (34-normoalbuminuria; 30-microalbuminuria; 22-macroalbuminuria) and 28 healthy subjects were enrolled in the study and assessed concerning urinary podocytes, podocyte-associated molecules, and biomarkers of proximal tubule dysfunction. Urinary podocytes were examined in cell cultures by utilizing monoclonal antibodies against podocalyxin and synaptopodin., Results: Podocytes were detected in the urine of 10% of the healthy controls, 24% of the normoalbuminuric, 40% of the microalbuminuric, and 82% of the macroalbuminuric patients. In multivariate logistic regression analysis, urinary podocytes correlated with urinary albumin:creatinine ratio (p=0.006), urinary nephrin/creat (p=0.001), urinary vascular endothelial growth factor/creat (p=0.001), urinary kidney injury molecule-1/creat (p=0.003), cystatin C (p=0.001), urinary advanced glycation end-products (p=0.002), eGFR (p=0.001)., Conclusions: In patients with type 2 diabetes podocyturia parallels proximal tubule dysfunction independently of albuminuria and renal function decline. Advanced glycation end-products may impact the podocytes and the proximal tubule., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Aim: The renal and cerebral protective effects of pioglitazone were assessed in normoalbuminuric patients with type 2 diabetes mellitus (DM)., Methods: A total of 68 normoalbuminuric type 2 DM patients were enrolled in a one-year open-label randomized controlled trial: 34 patients (pioglitazone-metformin) vs. 34 patients (glimepiride-metformin). All patients were assessed concerning urinary albumin: creatinine ratio (UACR), urinary alpha1-microglobulin, urinary beta2-microglobulin, plasma asymmetric dymethyl-arginine (ADMA), GFR, hsC-reactive protein, fibrinogen, HbA1c; pulsatility index, resistance index in the internal carotid artery and middle cerebral artery, intima-media thickness in the common carotid artery; cerebrovascular reactivity was evaluated through the breath-holding test., Results: At 1 year there were differences between groups regarding ADMA, urinary beta2-microglobulin, urinary alpha1-microglobulin, parameters of inflammation, serum creatinine, GFR, UACR, the cerebral haemodynamic indices. Significant correlations were found between alpha 1-microglobulin-UACR (R(2)=0.143; P=0.001) and GFR (R(2)=0.081; P=0.01); beta2-microglobulin-UACR (R(2)=0.241; P=0.0001) and GFR (R(2)=0.064; P=0.036); ADMA-GFR (R(2)=0.338; P=0.0001), parameters of inflammation, HbA1c, duration of DM, cerebral indices. There were no correlations between ADMA-UACR, urinary alpha1-microglobulin and beta2-microglobulin., Conclusion: Proximal tubule (PT) dysfunction precedes albuminuria and is dissociated from endothelial dysfunction in patients with type 2 DM. Pioglitazone delays PT dysfunction and improves cerebral vessels endothelial dysfunction in normoalbuminuric patients with type 2 DM., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Introduction: The aim of our study was to clarify the hypothesis that proximal tubule (PT) dysfunction may be responsible for early diabetic nephropathy (DN), independently of preceding glomerular endothelial dysfunction. The pattern of endothelial dysfunction and its potential variability was evaluated in two vascular beds, the kidney and the brain., Methods: A total of 68 normoalbuminuric type 2 diabetes mellitus (DM) patients were enrolled in a cross-sectional study and the following parameters were assessed: urinary albumin:creatinine ratio (UACR), urinary α(1)-microglobulin, urinary β(2)-microglobulin, plasma asymmetric dimethyl-arginine (ADMA), serum creatinine, glomerular filtration rate (GFR), C-reactive protein (CRP), fibrinogen, HbA(1c); pulsatility and resistance indices in the internal carotid artery and middle cerebral artery and intima-media thickness (IMT) in the common carotid artery; cerebrovascular reactivity was evaluated through the breath-holding test., Results: Plasma ADMA was increased in 12 patients (17.5%), urinary α(1)-microglobulin in 19 patients (27.9%) and urinary β(2)-microglobulin in 16 patients (23.5%). Cerebral hemodynamic indices correlated with plasma ADMA, CRP, fibrinogen, duration of DM, HbA(1c) and GFR. ADMA correlated with fibrinogen, CRP, HbA(1c), duration of DM and GFR. There were no correlations between ADMA and UACR, and urinary α(1)-/β(2)-microglobulin. Also, no correlations were found between urinary α(1)-/β(2)-microglobulin and UACR, HbA(1c), duration of DM and GFR., Conclusion: The increase in urinary α(1)-/β(2)-microglobulin precedes the stage of albuminuria. It may be assumed that early DN is related to PT dysfunction. Endothelial dysfunction plays a pivotal role in the brain vasculature, while its involvement in the development of early DN is not conditional on the occurrence of albuminuria., (Copyright © 2010 S. Karger AG, Basel.)