Trimetazidine Protects from Mercury-Induced Kidney Injury.

INTRODUCTION: The presence of mercury in the environment is a worldwide concern. Inorganic mercury is present in industrial materials, is employed in medical devices, is widely used in batteries, is a component of fluorescent light bulbs, and it has been associated with human poisoning in gold mining areas. The nephrotoxicity induced by inorganic mercury is a relevant health problem mainly in developing countries. The primary mechanism of mercury toxicity is oxidative stress. Trimetazidine (TMZ) is an anti-ischemic drug, which inhibits cellular oxidative stress, eliminates oxygen-free radicals, and improves lipid metabolism. The aim of this study was to evaluate whether the administration of TMZ protects against mercuric chloride (HgCl2) kidney damage. METHODS: Adult male Wistar rats received only HgCl2 (4 mg/kg bw, sc) (Hg group, n = 5) or TMZ (3 mg/kg bw, ip) 30 min before HgCl2 administration (4 mg/kg bw, sc) (TMZHg group, n = 7). Simultaneously, a control group of rats (n = 4) was studied. After 4 days of HgCl2 injection, urinary flow, urea and creatinine (Cr) plasma levels, Cr clearance, urinary glucose, and sodium-dicarboxylate cotransporter 1 (NaDC1) in urine were determined. Lipid peroxidation (MDA) and glutathione (GSH) levels were measured in kidney homogenates. RESULTS: Rats only treated with HgCl2 showed an increase in urea and Cr plasma levels, urinary flow, fractional excretion of water, glucosuria, and NaDC1 urinary excretion as compared with the control group and a decrease in Cr clearance. TMZHg group showed a decrease in urea and Cr plasma levels, urinary flow, fractional excretion of water, glucosuria, NaDC1 urinary excretion, and an increase in Cr clearance when compared to the Hg group. Moreover, MDA and GSH levels observed in Hg groups were decreased and increased, respectively, by TMZ pretreatment. CONCLUSION: TMZ exerted a renoprotective action against HgCl2-induced renal injury, which might be mediated by the reduction of oxidative stress. Considering the absence of toxicity of TMZ, its clinical application against oxidative damage due to HgCl2-induced renal injury should be considered. The fact that TMZ is commercially available should simplify and accelerate the translation of the present data "from bench to bedside." In this context, TMZ become an interesting new example of drug repurposing.

Glycemic control by the SGLT2 inhibitor empagliflozin decreases aortic stiffness, renal resistivity index and kidney injury.

BACKGROUND: Arterial stiffness is emerging as an independent risk factor for the development of chronic kidney disease. The sodium glucose co-transporter 2 (SGLT2) inhibitors, which lower serum glucose by inhibiting SGLT2-mediated glucose reabsorption in renal proximal tubules, have shown promise in reducing arterial stiffness and the risk of cardiovascular and kidney disease in individuals with type 2 diabetes mellitus. Since hyperglycemia contributes to arterial stiffness, we hypothesized that the SGLT2 inhibitor empagliflozin (EMPA) would improve endothelial function, reduce aortic stiffness, and attenuate kidney disease by lowering hyperglycemia in type 2 diabetic female mice (db/db). MATERIALS/METHODS: Ten-week-old female wild-type control (C57BLKS/J) and db/db (BKS.Cg-Dock7m+/+Leprdb/J) mice were divided into three groups: lean untreated controls (CkC, n = 17), untreated db/db (DbC, n = 19) and EMPA-treated db/db mice (DbE, n = 19). EMPA was mixed with normal mouse chow at a concentration to deliver 10 mg kg-1 day-1, and fed for 5 weeks, initiated at 11 weeks of age. RESULTS: Compared to CkC, DbC showed increased glucose levels, blood pressure, aortic and endothelial cell stiffness, and impaired endothelium-dependent vasorelaxation. Furthermore, DbC exhibited impaired activation of endothelial nitric oxide synthase, increased renal resistivity and pulsatility indexes, enhanced renal expression of advanced glycation end products, and periarterial and tubulointerstitial fibrosis. EMPA promoted glycosuria and blunted these vascular and renal impairments, without affecting increases in blood pressure. In addition, expression of "reversion inducing cysteine rich protein with Kazal motifs" (RECK), an anti-fibrotic mediator, was significantly suppressed in DbC kidneys and partially restored by EMPA. Confirming the in vivo data, EMPA reversed high glucose-induced RECK suppression in human proximal tubule cells. CONCLUSIONS: Empagliflozin ameliorates kidney injury in type 2 diabetic female mice by promoting glycosuria, and possibly by reducing systemic and renal artery stiffness, and reversing RECK suppression.

Paquinimod prevents development of diabetes in the non-obese diabetic (NOD) mouse.

Quinoline-3-carboxamides (Q compounds) are immunomodulatory compounds that have shown efficacy both in autoimmune disease and cancer. We have in here investigated the impact of one such compound, paquinimod, on the development of diabetes in the NOD mouse model for type I diabetes (T1D). In cohorts of NOD mice treated with paquinimod between weeks 10 to 20 of age and followed up until 40 weeks of age, we observed dose-dependent reduction in incidence of disease as well as delayed onset of disease. Further, in contrast to untreated controls, the majority of NOD mice treated from 15 weeks of age did not develop diabetes at 30 weeks of age. Importantly, these mice displayed significantly less insulitis, which correlated with selectively reduced number of splenic macrophages and splenic Ly6Chi inflammatory monocytes at end point as compared to untreated controls. Collectively, these results demonstrate that paquinimod treatment can significantly inhibit progression of insulitis to T1D in the NOD mouse. We propose that the effect of paquinimod on disease progression may be related to the reduced number of these myeloid cell populations. Our finding also indicates that this compound could be a candidate for clinical development towards diabetes therapy in humans.

Bone marrow transplantation improves proximal tubule dysfunction in a mouse model of Dent disease.

Dent disease is a rare X-linked tubulopathy caused by mutations in the endosomal chloride-proton exchanger (ClC-5) resulting in defective receptor-mediated endocytosis and severe proximal tubule dysfunction. Bone marrow transplantation has recently been shown to preserve kidney function in cystinosis, a lysosomal storage disease causing proximal tubule dysfunction. Here we test the effects of bone marrow transplantation in Clcn5Y/- mice, a faithful model for Dent disease. Transplantation of wild-type bone marrow in Clcn5Y/- mice significantly improved proximal tubule dysfunction, with decreased low-molecular-weight proteinuria, glycosuria, calciuria, and polyuria four months after transplantation, compared to Clcn5Y/- mice transplanted with ClC-5 knockout bone marrow. Bone marrow-derived cells engrafted in the interstitium, surrounding proximal tubule cells, which showed a rescue of the apical expression of ClC-5 and megalin receptors. The improvement of proximal tubule dysfunction correlated with Clcn5 gene expression in kidneys of mice transplanted with wild-type bone marrow cells. Coculture of Clcn5Y/- proximal tubule cells with bone marrow-derived cells confirmed rescue of ClC-5 and megalin, resulting in improved endocytosis. Nanotubular extensions between the engrafted bone marrow-derived cells and proximal tubule cells were observed in vivo and in vitro. No rescue was found when the formation of the tunneling nanotubes was prevented by actin depolymerization or when cells were physically separated by transwell inserts. Thus, bone marrow transplantation may rescue the epithelial phenotype due to an inherited endosomal defect. Direct contacts between bone marrow-derived cells and diseased tubular cells play a key role in the rescue mechanism.

Antidiabetic and antioxidant potential of ß-sitosterol in streptozotocin-induced experimental hyperglycemia.

BACKGROUND: Oxidative stress, produced under diabetic conditions, may cause tissue damage. Although several drugs are currently available for the treatment of diabetes, their continued use may cause unwanted side effects. The aim of the present study was to evaluate the antioxidant potential of ß-sitosterol (BS), a phytosterol from Solanum surattense, using an experimental model for diabetes-induced oxidative damage. METHODS: The effects of 21 days treatment with BS (10, 15 and 20 mg/kg, p.o.) on blood, serum, and tissue biochemical parameters were evaluated in control and streptozotocin-induced diabetic rats. Nine experimental groups, including a control group, a diabetic group, and BS- and glibenclamide-treated diabetic groups, were evaluated. RESULTS: All three dose levels dose dependently resulted in decreases in glycated hemoglobin, serum glucose, and nitric oxide, with concomitant increases in serum insulin levels. Furthermore, treatment with BS doses also increased pancreatic antioxidant levels, with a concomitant decrease in thiobarbituric acid-reactive substances. CONCLUSIONS: ß-Sitosterol has promising antidiabetic as well as antioxidant effects and may be considered in clinical studies for drug development.

Crocin attenuates cisplatin-induced renal oxidative stress in rats.

Reactive oxygen species (ROS) and oxidative damage are the most important factors in cisplatin-induced acute renal failure. This study examined the protective effects of crocin against cisplatin-induced renal oxidative stress in rat. Animals were divided into five groups (n=6). Group 1 received normal saline (2 ml/day, i.p.). Group 2 received a single dose of cisplatin (5mg/kg, i.p.). Groups 3-5 received crocin (100, 200, and 400mg/kg, i.p., respectively) for four consecutive days beginning 1-h before a single dose of cisplatin (5mg/kg) on day 1. On day 5, blood samples were drawn and kidneys were removed for histopathological, biochemical and RT-PCR examinations. Twenty four hours urinary chemistries were measured. Blood urea and creatinine and urinary glucose and protein concentrations in crocin-treated groups were significantly lower compared to the cisplatin-treated group. Histopathological studies showed massive damage in the S(3) segment of proximal tubules in cisplatin-treated group but not in crocin-treated groups. Crocin treatment resulted in a significant reduction in malondialdehyde (MDA) concentration and produced a significant elevation in total thiol and glutathione peroxidase concentrations. There was a significant elevation in the mRNA expression of glutathione peroxidase in crocin-treated groups. The results suggest that crocin attenuates cisplatin-induced renal oxidative stress in rats.

Protective effects of crocin against cisplatin-induced acute renal failure and oxidative stress in rats.

BACKGROUND: The major side effect of cisplatin, used in some tumours, is nephrotoxicity. Reactive oxygen species and oxidative damage are the most important factors in cisplatin-induced acute renal failure. The main purpose of this study is to investigate the protective effects of crocin against cisplatin-induced acute renal failure and oxidative stress in rat. METHODS: In this study, animals were randomly divided into 5 groups (6 each). Group one received normal saline (2 ml/day, i.p.). Group two received a single dose of cisplatin (5 mg/kg, i.p.). Groups 3 to 5 received crocin (100, 200 and 400 mg/kg, i.p., respectively, for 4 consecutive days one hour before a single dose of cisplatin (5 mg/kg) only at the first day. Blood samples were taken out (on the fifth day) for measuring the level of urea and creatinine. The kidneys were removed for histopathological and biochemical examinations. Furthermore, 24-hour urinary factors were measured. RESULTS: Blood urea, creatinine and urinary glucose and protein concentrations in crocin-treated groups were significantly lower than those of cisplatin-treated group in a dose-dependent manner. Histopathological studies showed a massive damage in S3 segment of proximal tubules in cisplatin-treated group. No damage was observed in crocin-treated groups. Crocin treatment resulted in a significant and dose-dependent reduction in malondialdehyde concentration as compared to the cisplatin-treated group. Moreover, crocin produced a significant elevation in total thiol and glutathione peroxidase concentrations, as compared with cisplatin-treated group. CONCLUSION: The results of the present study suggest that crocin has a protective effect against cisplatin-induced acute renal failure and relative oxidative stress.

[A diabetic patient with cystitis emphysematosa]. / Een diabetespatiënt met cystitis emphysematosa.

In a woman aged 80 years arriving in the Emergency Room with progressive malaise, anorexia and somnolence, a large resistance was found in the lower abdomen, which proved to be due to cystitis emphysematosa. The patient was known to suffer from non-insulin dependent diabetes mellitus. Imaging revealed a large accumulation of gas in the urinary bladder, which was treated successfully with catheterization and antibiotics. Cystitis emphysematosa is a rare condition, characterized by collection of gas in the bladder and bladder wall and brought about by gas-forming micro-organisms that decompose glucose. In patients with diabetes mellitus optimal regulation of the blood glucose levels, with a view to preventing glycosuria, is a condition of speedy recovery. Although cases with a fatal outcome have been reported, the prognosis in general is favourable.

Detecting GD and preeclampsia. Effectiveness of routine urine screening for glucose and protein.

OBJECTIVE: To assess why urine collection and analysis for proteinuria and glycosuria is routinely performed during each antepartum visit at prenatal clinics. STUDY DESIGN: Six hundred ten antepartum medical records were reviewed. RESULTS: One hundred nine (18%) patients had proteinuria, while 17 patients (2.8%) developed preeclampsia. Fifteen patients (2.5%) had at least one episode of glycosuria (100 mg/dL), while 11 had gestational diabetes. Of those with gestational diabetes, four (36%) had glycosuria. Of those with preeclampsia, three (17.7%) had proteinuria that preceded the finding of hypertension. CONCLUSION: These results support our observation that routine oral 50-g glucose diabetes screening and careful monitoring of blood pressure are better screens for gestational diabetes and preeclampsia. The increased patient inconvenience and clinic staffing necessary for routine urinalysis may be avoided by eliminating that ritual.

Protective effects of chelating agents against renal toxicity of gold sodium thiomalate in rats.

The protective effects of various chelating agents such as D-penicillamine (D-PEN), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropane sulphonate (DMPS), and N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine), on the renal damage induced by gold sodium thiomalate (AuTM) in rats were studied. Rats were injected i.v. with AuTM at doses of 0.026, 0.066, 0.132, and 0.198 mmol/kg. Urinary excretion of protein, aspartate aminotransferase (AST), and glucose in rats injected with AuTM significantly increased compared to the control levels within 1 day after the injection and thereafter decreased nearly to the control levels at 3 or 7 days. Gold was excreted rapidly during the first day after AuTM injection and excreted gradually thereafter. The concentrations of gold in the kidney and liver at 1 or 7 days after AuTM administration were approximately dose dependent. Treatment with D-PEN, DMSA, DMPS, and bucillamine (1.2 mmol/kg) significantly prevented increases in the urinary excretion of protein, AST, and glucose and the BUN level after AuTM (0.026 mmol/kg) injection. The injection of the chelating agents after AuTM administration showed that D-PEN, DMSA, and DMPS enhanced mainly the urinary excretion of gold and that bucillamine enhanced mainly the fecal excretion of the metal. These chelating agents significantly decreased the gold concentrations in the kidney and liver. The findings suggest that the chelating agents tested can ameliorate the renal damage induced by AuTM.

Effect of N-benzyl-D-glucamine dithiocarbamate on renal toxicity induced by cadmium-metallothionein in rats.

The effect of N-benzyl-D-glucamine dithiocarbamate (BGD) on the renal toxicity induced by acute exposure to cadmium-metallothionein (Cd-MT) in rats was studied. Rats were injected intraperitoneally with BGD (400 mumol/kg) 6, 12, or 24 h after intraperitoneal injection of Cd-MT (1.78 mumol Cd as Cd-MT/kg) and thereafter they received three injections of BGD (400 mumol/kg) daily for 3 days. Urinary protein concentration and aspartate aminotransferase (AST) activity significantly increased 1 day after Cd-MT treatment and decreased to control levels at 9 days after the treatment. Urinary excretion of glucose and amino acids rose gradually reaching maximum levels 5 days after Cd-MT treatment and returned to the control levels at 9 days. BGD injection significantly reduced the increases in the urinary excretion of protein, AST, glucose and amino acid, which were produced by Cd-MT treatment. Significant increases in urine volume were observed after Cd-MT treatment. BGD injection inhibited the increase in urine volume caused by Cd-MT treatment. A long time interval (12 and 24 h) between the administrations of Cd-MT and BGD resulted in a decreased protective effect of BGD against Cd-MT-induced renal damage. Following Cd-MT injection, the major route of excretion of cadmium (Cd) was via the urine and the kidney was the major site of accumulation of Cd. BGD injection remarkably increased the urinary excretion of Cd, resulting in a significant reduction in the kidney Cd concentration. The results of this study indicate that BGD injection is effective in decreasing the Cd concentration in the kidney, resulting in the protective effect on Cd-MT-induced renal damage.

Screening for hematuria, glucosuria and proteinuria in people aged 55-64. Technical, clinical and cost-benefit experience from a pilot study.

A total of 754 persons randomly selected from the age group 55-64 years were invited by letter to take part in a screening for hematuria, proteinuria and glucosuria. Each person was asked to provide one sample of morning urine and immediately mail it to the laboratory. A total of 413 persons (55%) responded. Two dipsticks: BM-Test-5L and a new single strip for hematuria determination preliminary named BM 33075 were used, both manufactured by Boehringer Mannheim GmbH. The test strips gave positive reaction for hematuria in 21 persons (5.1%), for proteinuria in 14 persons (3.4%), and for glucosuria in six persons (1.5%). All persons with positive tests were invited to follow-up investigations. In the hematuria group we found one person with a malignant disease, 13 with benign conditions and in seven persons we found no reason for the hematuria. Among those with proteinuria one person had a nephritis. Four persons with glucosuria knew about their diabetes mellitus. The cost of the screening was NOK 99 per participant.