Symmetric dimethyl arginine and N-acetyl-β-D-glucosaminidase lysozimuria of proximal renal tubules as a target for nephrotoxicity in patients with rheumatoid arthritis treated with disease modifying antirheumatic drugs

Advances in Optical Sensors of N-Acetyl-β-d-hexosaminidase (N-Acetyl-β-d-glucosaminidase)

N-Acetyl-β-d-hexosaminidases (EC 3.2.1.52) are exo-acting glycosyl hydrolases that remove N-acetyl-β-d-glucosamine (Glc-NAc) or N-acetyl-β-d-galactosamine (Gal-NAc) from the nonreducing ends of various biomolecules including oligosaccharides, glycoproteins, and glycolipids. The same enzymes are sometimes called N-acetyl-β-d-glucosaminidases, and this review article employs the shorthand descriptor HEX(NAG) to indicate that the terms HEX or NAG are used interchangeably in the literature. The wide distribution of HEX(NAG) throughout the biosphere and its intracellular location in lysosomes combine to make it an important enzyme in food science, agriculture, cell biology, medical diagnostics, and chemotherapy. For more than 50 years, researchers have employed chromogenic derivatives of N-acetyl-β-d-glucosaminide in basic assays for biomedical research and clinical chemistry. Recent conceptual and synthetic innovations in molecular fluorescence sensors, along with concurrent technical improvements in instrumentation, have produced a growing number of new fluorescent imaging and diagnostics methods. A systematic summary of the recent advances in optical sensors for HEX(NAG) is provided under the following headings: assessing kidney health, detection and treatment of infectious disease, fluorescence imaging of cancer, treatment of lysosomal disorders, and reactive probes for chemical biology. The article concludes with some comments on likely future directions.

The role of microalbuminuria as a predictor of subclinical cardiovascular events in rheumatoid arthritis patients and its relation to disease activity

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects many body tissues and leads to major morbidity and mortality. Renal disease in RA is clinically important because it restricts the management of primary disease and increases mortality. The objectives of this study are to (1) investigate the difference between RA patients with and without microalbuminuria (MAU) and (2) find out the relation between MAU and disease activity as well as subclinical cardiovascular effects. Ninety RA patients were divided into two groups according to the presence of MAU, in addition to 30 healthy volunteers. ESR, hs-CRP, RF, lipid profile, urinary microalbumin, GFR, renal function tests, carotid intima media thickness (cIMT), flow-mediated dilatation of the brachial artery (FMD), ECG, and echocardiographic examination were performed for patients and controls. MAU positive RA patients revealed significantly higher lipid profile, ESR, hs-CRP, DAS 28, cIMT, and lower FMD as well as ECG and echocardiographic abnormalities compared to MAU negative RA patients. Moreover, there was significant positive correlation between MAU and DAS28, hs-CRP, LDL, cIMT as well as negative correlation with FMD%. In our study, all RA patients with MAU had a normal serum creatinine concentration and gave a negative result with Albustix. MAU is significantly correlated with ESR, hs-CRP, lipid profile, cIMT, and FMD% in RA patients; therefore, it can be used as an index to measure disease activity as well as subclinical cardiovascular affection in RA patients.

Role of mesenchymal stem cells versus angiotensin converting enzyme inhibitor in kidney repair

AIM

The current study sought to clarify the role of bone marrow derived mesenchymal stem cells (BM-MSCs) and adipose tissue derived mesenchymal stem cells (AD-MSCs) in repressing nephropathy in the experimental model. Moreover, the aim of this work was extended to compare between stem cells role and angiotensin converting enzyme inhibitor in kidney repair.

METHODS

Isolation and preparation of MSCs culture, flow cytometry using CD34, CD44 and CD105 cell surface markers, biochemical analyses for determination of serum creatinine, urea, transforming growth factor β (TGF-β), cystatin C (CYS-C) and urinary N-Acetyl-ß-D-Glucosaminidase (UNAG), and histopathological investigation of kidney tissue sections were performed.

RESULTS

The results of the present study revealed that single intravenous infusion of MSCs either derived from bone marrow or adipose tissue was able to enhance renal reparative processes through significantly decreased serum creatinine, urea, TGF-β and CYS-C levels as well as UNAG level and significantly increase glomerular filtration rate. Additionally, the histopathological investigations of kidney tissues showed that MSCs have significant regenerative effects as evidenced by the decrease in focal inflammatory cells infiltration, focal interstitial nephritis and congested glomeruli as well as degenerated tubules.

CONCLUSION

The current data provided distinct evidence about the favourable impact of AD-MSCs and BM-MSCs in attenuation of cyclosporine-induced nephropathy in rats through their ability to promote functional and structural kidney repair via transdifferentiation.

The protective potential of metformin against acetaminophen-induced hepatotoxicity in BALB/C mice

CONTEXT

Acetaminophen overdose is regarded to a common cause of acute liver failure. The hepatotoxicity leads to mitochondrial oxidative stress and subsequent necrotic hepatocellular death.

OBJECTIVE

This study examines the protective effect of metformin on acetaminophen-induced oxidative stress, inflammation and subsequent hepatotoxicity in mice.

MATERIALS AND METHODS

Male BALB/c mice were orally administered to acetaminophen (250 mg/kg/d) for a 7-day period. The mice received metformin (100 and 200 mg/kg/d, p.o.) for 21 days. To evaluate acetaminophen-induced oxidative stress, liver tissue level of malodialdehyde (MDA), end product of membrane lipid peroxidation, and activities of superoxide dismutase (SOD) and glutathione (GSH) were measured. Histological analysis and measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were performed. Moreover, tissue concentrations of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), along with, C-reactive protein (CRP) were assessed.

RESULTS

Acetaminophen caused focal hepatocyte necrosis, inflammation and fatty degeneration, as well as increased tissue levels of AST, ALT, ALP and MDA, and also decreased GSH and SOD activities. Moreover, IL-6, TNF-α and CRP levels were increased following acetaminophen hepatotoxicity. Metformin (200 mg/kg/d) significantly normalized MDA, SOD and GSH levels (p < 0.001), and exerted a hepatoprotective effect by significant decreasing ALT, AST and ALP concentrations (p < 0.001). The tissue levels of IL-6, TNF-α and CRP were markedly decreased by 21-day treatment with metformin (200 mg/kg/d) (p < 0.001).

DISCUSSION

The results suggest metformin protects hepatocytes against acute acetaminophen toxicity. Metformin is indicated to diminish oxidative stress, proinflammatory cytokines, and hepatocyte necrosis.