Urinary peptidomics in a rodent model of diabetic nephropathy highlights epidermal growth factor as a biomarker for renal deterioration in patients with type 2 diabetes.

Many diabetic patients suffer from declining renal function without developing albuminuria. To identify alternative biomarkers for diabetic nephropathy (DN) we performed urinary peptidomic analysis in a rodent model in which hyperglycemia and hypertension synergize to promote renal pathologic changes consistent with human DN. We identified 297 increased and 15 decreased peptides in the urine of rats with DN compared with controls, including peptides derived from proteins associated with DN and novel candidate biomarkers. We confirmed by ELISA that one of the parent proteins, urinary epidermal growth factor (uEGF), was more than 2-fold reduced in rats with DN in comparison with controls. To assess the clinical utility of uEGF we examined renal outcomes in 642 participants from the Edinburgh Type 2 Diabetes Study who were normoalbuminuric and had preserved renal function at baseline. After adjustment for established renal risk factors, a lower uEGF to creatinine ratio was associated with new-onset estimated glomerular filtration rate less than 60 ml/min per 1.73m(2) (odds ratio 0.48; 95% confidence interval, 0.26-0.90), rapid (over 5% per annum) decline in renal function (odds ratio 0.44; 95% confidence interval, 0.27-0.72) or the composite of both outcomes (odds ratio 0.38; 95% confidence interval, 0.24-0.62). Thus, the utility of a low uEGF to creatinine ratio as a biomarker of progressive decline in renal function in normoalbuminuric patients should be assessed in additional populations.

Clinical significance of serum and urinary HER2/neu protein levels in primary non-muscle invasive bladder cancer.

OBJECTIVE: We aimed to compare serum and urinary HER2/neu levels between healthy control group and patients with non-muscle invasive bladder cancer. Additionally, we evaluated relationship of HER2/neu levels with tumor stage, grade, recurrence and progression. MATERIALS AND METHODS: Fourty-four patients with primary non-muscle invasive bladder tumors (Group 2) and 40 healthy control group (Group 1) were included the study. Blood and urinary samples were collected from all patients and HER2/neu levels were measured by ELISA method. Blood and urinary HER2/neu levels and additionally, ratio of urinary HER2/neu levels to urinary creatinine levels were recorded. Demographic data and tumor characteristics were recorded. RESULTS: Mean serum HER2/neu levels were similar between two groups and statistically significant difference wasn't observed. Urinary HER2/neu levels were significantly higher in group 2 than group 1. Ratio of urinary HER2/neu to urinary creatinine was significantly higher in group 2 than group 1, (p=0,021). Serum and urinary HER2/ neu levels were not associated with tumor stage, grade, recurrence and progression while ratio of urinary HER2/neu to urinary creatinin levels were significantly higher in high-grade tumors. HER2/neu, the sensitivity of the test was found to be 20.5%, and the specificity was 97.5%, also for the urinary HER2/neu/urinary creatinine ratio, the sensitivity and specificity of the test were found to be 31.8% and 87.5%, respectively. CONCLUSIONS: Urinary HER2/neu and ratio of urinary creatinine urine were significantly higher in patients with bladder cancer compared to healthy subjects. Large series and controlled studies are needed for use as a tumor marker.

The Role of MicroRNAs and Human Epidermal Growth Factor Receptor 2 in Proliferative Lupus Nephritis.

OBJECTIVE: To understand the roles of microRNAs (miRNAs) in proliferative lupus nephritis (LN). METHODS: A high-throughput analysis of the miRNA pattern of the kidneys of LN patients and controls was performed by molecular digital detection. Urinary miRNAs were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Target gene expression in human mesangial cells was evaluated by arrays and qRT-PCR. Human epidermal growth factor receptor 2 (HER-2) was analyzed by immunohistochemistry in kidney samples from LN patients and in a murine model of lupus. Urinary levels of HER-2, monocyte chemotactic protein 1 (MCP-1), and vascular cell adhesion molecule 1 (VCAM-1) were measured by enzyme-linked immunosorbent assay. RESULTS: Levels of the miRNAs miR-26a and miR-30b were decreased in the kidneys and urine of LN patients. In vitro these miRNAs controlled mesangial cell proliferation, and their expression was regulated by HER-2. HER-2 was overexpressed in lupus-prone NZM2410 mice and in the kidneys of patients with LN, but not in other mesangioproliferative glomerulonephritides. HER-2 was found to be up-regulated by interferon-α and interferon regulatory factor 1. Urinary HER-2 was increased in LN and reflected disease activity, and its levels correlated with those of 2 other recognized LN biomarkers, MCP-1 and VCAM-1. CONCLUSION: The kidney miRNA pattern is broadly altered in LN, which contributes to uncontrolled cell proliferation. Levels of the miRNAs miR-26a and miR-30b are decreased in the kidneys and urine of LN patients, and they directly regulate the cell cycle in mesangial cells. The levels of these miRNAs are controlled by HER-2, which is overexpressed in NZM2410 mice and in the kidneys and urine of LN patients. HER-2, miR-26a, and miR-30b are thus potential LN biomarkers, and blocking HER-2 may be a promising new strategy to decrease cell proliferation and damage in this disease.