Urinary N-acetyl-β-D-glucosaminidase (NAG) activity in the early detection of diabetic nephropathy

Anchoring copper nanoclusters to Al2O3 microsphere for dual-mode analysis of N-acetyl-β-D-glucosaminidase and information encryption

Herein, we attempted to confine copper nanoclusters (CuNCs) with alumina (Al2O3) as the matrix (Al2O3@CuNCs), which effectively circumvented the drawbacks of CuNCs (such as weak photoluminescence and low quantum yield). Al2O3@CuNCs demonstrated sensitive response to p-nitrophenol, the catalytic product of N-acetyl-β-D-glucosaminidase (NAG) on account of the inner filter effect and dynamic quenching effect. In light of this, a novel assay was created to identify NAG, a critical indicator of diabetic nephropathy. Additionally, a portable and instrument-free sensing platform mainly consisting of a smartphone, a cuvette, a cuvette holder, a dark box and a 365 nm UV lamp was developed for the quantitative detection of NAG. The as-prepared material was also utilized in anti-counterfeiting and information encryption based on their excellent optical properties and sensitive response to the catalyzed product of NAG. This work advanced potential applications of CuNCs composites in the areas of portable, multi-mode biosensing, anti-counterfeiting and information encryption.

Urinary N-Acetyl-β-D glucosaminidase (uNAG) levels as an early marker for diabetic nephropathy in children with type 1 diabetes

Background

Diabetic nephropathy is considered a major complication among patients with type 1 diabetes. In the present study, we aimed to evaluate urinary N-acetyl-beta-D-glucosaminidase levels (uNAG) in patients with type 1 diabetes mellitus (DM).

Methods

This cross-sectional study of 60 patients with type 1 DM, was categorized into two groups (normoalbuminuria and microalbuminuria) and 30 healthy controls. uNAG was measured in all cases and controls.

Results

Patients with type 1 DM showed increased mean uNAG values compared to controls. Interestingly, increased NAG levels were found in diabetic patients without early signs of glomerular damage (normoalbuminuric). The severity of renal disease, poor glycemic control, and duration of diabetes were all proportional to uNAG increased levels.

Conclusions

NAG measurement is a useful, noninvasive tool for assessing renal involvement in children with diabetes and for early diagnosis of developing nephropathy.

Early detection of diabetic nephropathy in patient with type 2 diabetes mellitus: A review of the literature

Type 2 diabetes mellitus is a pathology of heterogeneous etiology characterized by hyperglycemia resulting from lack of insulin action, insulin secretion, or both, and the population with diabetes mellitus is predicted to be about 439 million worldwide by 2030. Prolong diabetes has been related with microvascular complications especially diabetic nephropathy. DN is the most common complication of type 2 diabetes mellitus, and it is the leading cause of end-stage renal disease worldwide. It is crucial to diagnose patients who are more sensible to develop DN for better control of the process of disease. Several factors and mechanisms contribute to the development and outcome of diabetic nephropathy. Microalbuminuria is an early marker of DN and use it as a routine for screening, but the renal damages may be happening even without microalbuminuria. There are several significant kidney damage and disease biomarkers which helps in early detection of DN. An early biomarker may allow earlier diagnosis, treatment reduces DN prevalence and slows DN progression. Therefore, this review focuses on laboratory biomarkers that are earlier, more validation of an early and specific biomarker could potentially make it possible for early diagnosis, treatment, and retardation of progression of diabetic nephropathy.

Increased urinary markers of kidney damage in the institutionalized frail elderly due to recurrent urinary tract infections

Objective:

To characterize the impact on kidney injury of recurrent urinary tract infections (RUTI) in the frail elderly.

Methods:

Prospective observational study in 200 frail elderly subjects for 1 year. Groups: GA (n = 100): subjects without RUTI, GB (n = 100): subjects with RUTI. Variables: age, concomitant diseases, glomerular filtration rate (GFR), urine neutrophil gelatinase-associated lipocalin (NGAL) at the beginning (NGAL-1) and end (NGAL-2) of the study, urine N-acetyl glucosaminidase (NAG) at the beginning (NAG-1) and the end (NAG-2) of the study, urine transforming growth factor-beta 1 (TGFβ-1). Descriptive statistics, Mann–Whitney test, Chi-squared test, Fisher’s exact test, and multivariate analysis were used.

Results:

Mean age was 84.33 (65–99) years old, with no difference between GA and GB. Mean NGAL-1 was 1.29 ng/ml (0.04–8). There was lower in GA than in GB. Mean NGAL-2 was 1.41 ng/ml (0.02–9.22). NGAL-2 was lower in GA than in GB. Mean NAG-1 was 0.38 UU.II/ml (0.01–2.63. NAG-1 in GA was lower than in GB. Mean NAG-2 was 0.44 UU.II/ml (0–3.41). NAG-2 was lower in GA compared with GB. Mean TGFβ-1 was 23.43 pg/ml (0.02–103.76). TGFβ-1 was lower in GA than GB. There were no differences in the presence of secondary diagnoses between GA and GB. NAG-2 and NGAL-1 were the most determining factors of renal function; in GA it was NGAL-2, followed by NAG-1; in GB it was NGAL-1, followed by NAG-2.

Conclusion:

Frail elderly with RUTI have higher urinary levels of renal injury markers, specifically NGAL, NAG, and TGFβ-1, chronically in periods between urinary tract infection (UTI). Urinary markers of renal injury, specifically NGAL, NAG, and TGFβ-1, identify early deterioration of renal function, compared with serum creatinine, or albuminuria, in frail elderly with recurrent urinary infections.

Carbon dots as fluorescent nanoprobe for the determination of N-acetyl-β-d-glucosaminidase activity

Carbon dots (CDs) were synthesized from p-aminophenol and ethylenediamine via one-step under mild condition and used as a sensitive fluorescent nanoprobe for the activity determination of N-acetyl-β-d-glucosaminidase (NAG). In this assay, p-nitrophenol was in situ produced from p-nitrophenyl-β-D-N-acetyl-glucosaminide, which was exclusively hydrolyzed by NAG. The UV absorption peak of p-nitrophenol (maximum at 400 nm) overlapped the excitation peak of CDs with maximum wavelength at 415 nm, which caused the fluorescence decline of CDs based on inner filter effect. The activity of NAG was determined by the fluorescence changes. The assay is highly sensitive to NAG with a low detection limit of 0.75 U L^-1 (K = 3) and showed a good linear relationship in the range from 1 to 45 U L^-1. This CDs nanoprobe was successfully applied for the determination of NAG activity in human serum and urine samples.

Urinary N-acetyl-beta-d-glucosaminidase (NAG) with neutrophil gelatinase-associated lipocalin (NGAL) improves the diagnostic value for proximal tubule damage in diabetic kidney disease

Screening for diabetic kidney disease (DKD) remains a challenge; however, there has been an ongoing research to investigate the diagnostic value of different biomarkers to identify DKD. The aim of this study was to assess the diagnostic value of both N-acetyl-beta-d-glucosaminidase (NAG) and neutrophil gelatinase-associated lipocalin (NGAL) in the progression of DKD. This cross-sectional case-control study included 92 type 2 diabetic patients with or without DKD. Urinary NAG and NGAL were measured to evaluate their diagnostic values as biochemical markers related to DKD. Both urinary NAG and NGAL levels were significantly higher among patients with DKD. In multiple linear regression analysis, NAG showed a positive significant association with NGAL in the three different adjusted models, while no significant correlation with fasting blood glucose, glycated hemoglobin, serum creatinine, estimated glomerular filtration rate, and albumin creatinine ratio were observed. The area under the curve for NGAL was 0.659 (p = 0.01) and 0.564 (p = 0.297) for NAG in DKD patients. This study demonstrates the association between urinary NAG and NGAL as a tubular damage marker for DKD although longitudinal studies are needed to evaluate its diagnostic value.