Microarray Expression Profile of Exosomal circRNAs from High Glucose Stimulated Human Renal Tubular Epithelial Cells.

Introduction: Circular RNA (circRNAs) are a type of non-coding RNA (ncRNAs) with a wealth of functions. Recently, circRNAs have been identified as important regulators of diabetic kidney disease (DKD), owing to their stability and enrichment in exosomes. However, the role of circRNAs in exosomes of tubular epithelial cells in DKD development has not been fully elucidated. Methods: In our study, microarray technology was used to analyze circRNA expression in cell supernatant exosomes isolated from HK-2 cells with or without high glucose (HG) treatment. The small interfering RNAs (siRNA) and plasmid overexpression were used to validate functions of differentially expressed circRNAs. Results: We found that exosome concentration was higher in HG-stimulated HK-2 cells than in controls. A total of 235 circRNAs were significantly increased and 458 circRNAs were significantly decreased in the exosomes of the HG group. In parallel with the microarray data, the qPCR results showed that the expression of circ_0009885, circ_0043753, and circ_0011760 increased, and the expression of circ_0032872, circ_0004716, and circ_0009445 decreased in the HG group. Rescue experiments showed that the effects of high glucose on regulation of CCL2, IL6, fibronetin, n cadherin, e cadherin and epcam expression can be reversed by inhibiting or overexpressing these circRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analyses indicated that circRNA parental genes are associated with glucose metabolism, lipid metabolism, and inflammatory processes, which are important in DKD development. Further analysis of circRNA/miRNA interactions indicated that 152 differentially expressed circRNAs with fold change (FC) ≥1.5 could be paired with 43 differentially expressed miRNAs, which are associated with diabetes or DKD. Discussion: Our results indicate that exosomal circRNAs may be promising diagnostic and therapeutic biomarkers, and may play a critical role in the progression of DKD.

Urinary liver-type fatty acid-binding protein change in gestational diabetes mellitus.

We compared urinary liver-type fatty acid-binding protein (L-FABP) among non-pregnant and pregnant women with and without gestational diabetes mellitus (GDM). Higher urinary L-FABP was found in pregnant with and without GDM, and considerably higher urinary L-FABP was found in the GDM group compared with the non-GDM group. Hyperglycemia and anemia were related with high urinary L-FABP expression.

Correlation of high urinary Smad1 level with glomerular hyperfiltration in type 2 diabetes mellitus.

The aim of this study was to assess the relationship between urinary Smad1 and glomerular hyperfiltration (GHF) in type 2 diabetes mellitus (T2DM), and to explore the factors related to the urinary Smad1 in T2DM. The reference value of the estimated glomerular filtration rate (eGFR) was determined in 248 healthy individuals. 30 patients with GHF, 58 patients with norm-GFR T2DM, and 24 healthy patients who served as controls were recruited. Urinary Smad1, fasting plasma glucose (FPG), fasting serum C-Peptide (C-P), hemoglobin A1C (HbA1c), cystatin C, and other chemistry laboratory parameters of T2DM participants and controls were measured. Patients with GHF had higher levels of urinary Smad1 than the control group, and those with norm-GFR. For T2DM patients with body mass index, age, and gender adjustments, urinary Smad1 was positively correlated with FPG, HbA1C, and eGFR, but negatively correlated with fasting serum C-P. Multivariate linear regression analysis demonstrated that eGFR, HbA1C, and fasting serum C-P were independently associated with urinary Smad1. High levels of urinary Smad1 were found in GHF patients with T2DM, which may be another potential mechanism of GHF in relation to diabetic nephropathy.

Urinary tubular biomarkers in short-term type 2 diabetes mellitus patients: a cross-sectional study.

The purpose of this study was to investigate the prevalence of tubular damage in short-term (less than five years) type 2 diabetes mellitus (T2DM) patients and to explore the correlation between tubular markers and their relationship with renal indices at different stages of diabetic nephropathy. A group of 101 short-term T2DM patients and 28 control subjects were recruited. Tubular markers, such as neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl-ß-D: -glucosaminidase (NAG), and kidney injury molecule 1 (KIM-1), as well as urinary albumin excretion were measured in voided urine. Glomerular filtration rate (GFR) was estimated via Macisaac's formula. The patients were further categorized into three groups, namely, the normoalbuminuria, microalbuminuria, and macroalbuminuria groups, according to their urine albumin/creatinine ratio (UACR). Urinary tubular markers were compared and their correlations with renal indices [UACR and estimated GFR (eGFR)] were analyzed among the different diabetic groups. Compared with the control group, Urinary NGAL [median (IQR)][83.6(41.4-138.7) µg/gcr vs. 32.9(26.1-64.5) µg/gcr], NAG [13.5(8.7-17.9) U/gcr vs. 7.6(6.5-13.0) U/gcr] and KIM-1 [120.0(98.4-139.9) ng/gcr vs. 103.1(86.8-106.2) ng/gcr] in the T2DM were all markedly increased. For all patients, urinary NGAL had stronger positive correlations with UACR than NAG (R = 0.556 vs. 0.305, both P < 0.05). In addition, only urinary NGAL showed a negative correlation with eGFR (R = -0.215, P < 0.05). Urinary KIM-1, however, showed no significant difference among the three T2DM groups and did not correlate with either UACR or eGFR. As UACR increased from the normoalbuminuria to the last macroalbuminuria group, all of the markers increased. However, only the concentrations of NGAL were statistically different among the three diabetic groups. The correlation between the tubular markers and their relationships with the renal indices differed markedly among the three T2DM groups. In conclusion, these results suggest that tubular damage is common in short-term T2DM patients. Urinary NGAL may be a promising early marker for monitoring renal impairment in short-term T2DM patients.

Changes of the tubular markers in type 2 diabetes mellitus with glomerular hyperfiltration.

AIM: To assess whether glomerular hyperfiltration (GHF) could result in renal tubular damage in type 2 diabetes mellitus (T2DM) patients. METHODS: Reference value of estimated glomerular filtration rate (eGFR) was determined in 248 healthy individuals based on serum CysC levels. GHF was defined as an eGFR exceeding the sex-specific 97.5th percentile in non-diabetic individuals. In the present study, 30 with GHF, 58 with norm-GFR T2DM, and 24 healthy controls were recruited. Tubular markers, such as urinary N-acetyl-ß-D-glucosaminidase (NAG) and kidney injury molecule 1 (KIM-1), as well as serum and urinary neutrophil gelatinase-associated lipocalin (NGAL), were measured and compared. The correlation of these markers with eGFR was analyzed in the GHF group. RESULTS: The GHF group had higher urinary NGAL and KIM-1 levels but lower serum NGAL level than the norm-GFR and control groups. Slightly decreased serum NGAL and increased urinary NGAL levels were also noted in the norm-GFR group compared with those of the controls. There was no statistical difference in the urinary NAG values among the three groups. Correlation analysis showed that eGFR was positively related to fasting blood glucose (FBG), HbA1c, urinary NGAL, and KIM-1, but negatively with serum NGAL in the GHF group. CONCLUSION: Higher urinary tubular damage markers were found in T2DM patients with GHF than the norm-GFR and control groups, probably a direct proof that GHF is a deleterious factor for diabetic nephropathy.

[Urinary level of tissue factor and its procoagulant activity in patients with type 2 diabetes].

OBJECTIVE: To examine the urinary level of tissue factor (uTF) and its procoagulant activity (PCA) in patients with diabetes mellitus, and explore the relationship between uTF and renal damage in diabetes mellitus. METHODS: Eighty-six patients with type 2 diabetes mellitus were divided into 3 groups according to urine albumin excretion (UACR), namely normal albuminuria group, microalbuminuria group and macroalbuminuria group. The levels of uTF, PCA, blood urea nitrogen (BUN), serum creatinine (CRE), serum cystatin C (CYSC), glycohemoglobin A1c (HbA1c), and high-sensitivity C-reactive protein (hs-CRP) were measured in all the patients and 21 healthy controls. RESULTS: Compared with normal control, the diabetic patients showed significantly increased levels of uTF and PCA. The urinary TF-PCA was positively correlated to BUN, CYSC, CRE, UACR, fasting glucose and hs-CRP, but not to uTF; only hs-CRP, UACR were positively correlated to uTF. CONCLUSION: uTF is probably implicated in the development and progression of diabetic nephropathy.