SH3YL1 protein as a novel biomarker for diabetic nephropathy in type 2 diabetes mellitus.

BACKGROUND AND AIMS: Oxidative stress contributes to development of diabetic nephropathy. We implicated SH3YL1 in oxidative stress-induced inflammation and examined whether SH3YL1 could be used as a new biomarker of diabetic nephropathy. METHODS AND RESULTS: In this study, we investigated the relationship between plasma level of SH3YL1 and diabetic nephropathy in patients with type 2 diabetes. In addition, we examined the physiological role of SH3YL1 in db/db mice and cultured podocytes. Plasma SH3YL1 concentration was significantly higher in patients with diabetes than in controls, even in normoalbuminuric patients, and was markedly increased in the macroalbuminuria group. Plasma SH3YL1 level was positively correlated with systolic blood pressure, HOMA-IR, postprandial blood glucose, plasma level of retinol binding protein 4 (RBP 4), and urinary albumin excretion (UAE) and was inversely correlated with BMI. Regression analysis showed that plasma level of RBP 4, UAE, and BMI were the only independent determinants of plasma SH3YL1 concentration. In db/db mice, plasma and renal SH3YL1 levels were significantly increased in mice with diabetes compared with control mice. In cultured podocytes, high glucose and angiotensin II stimuli markedly increased SH3YL1 synthesis. CONCLUSION: These findings suggest that plasma level of SH3YL1 offers a promising new biomarker for diabetic nephropathy.

Acute toxicity of a mixture of copper and single-walled carbon nanotubes to Daphnia magna.

Nanomaterials released into the environment will interact with many materials including other contaminants. This may influence bioavailability and fate of both the nanoparticles and the other contaminants. The present study examined the effect of a combination of soluble copper and surface-modified single-walled carbon nanotubes (SWNTs) on Daphnia magna. Lysophosphatidylcholine (LPC) was used to modify the surface of SWNTs, reducing the surface hydrophobicity of the tubes and thereby producing a stable aqueous nanoparticle suspension. The toxicity of the nanoparticle-copper (Cu) mixture was determined to be additive. The addition of nontoxic concentration of LPC-SWNTs enhanced the uptake and toxicity of copper. Greater amounts of Cu were shown to accumulate in D. magna upon addition of 0.5 and 1.0 mg/L LPC-SWNTs.

Estimating the combined effects of copper and phenol to nitrifying bacteria in wastewater treatment plants.

The inhibition of nitrification by phenol and copper mixtures was studied to investigate the differences between individual and mixture inhibition as the change of phenol and copper speciation due to their reactions. This study showed a decrease in the ammonium removal rate (k, first-order rate coefficient), indicating an increase in the relative % inhibition on nitrification, as the phenol and mixed liquor suspended solids (MLSS) concentrations were increased. In the case of copper, the ammonium removal rate decreased as the copper concentration increased and that of the MLSS decreased. This was attributed to the enhanced sorption of copper to heterotrophs at high MLSS concentrations. The relative % inhibition was plotted against free Cu2+ ions, which showed a close relationship. In the tests on copper and phenol mixtures, the mixture effects turned out overestimated by the calculation based on the additional chemical concentrations. In most Cu-phenol mixture tests, the presence of phenol as a complexation ligand caused a reduction of the inhibition rate to nitrifiers over the entire exposure range. Consequently, the prediction of nitrification inhibition in mixture environments, such as wastewater treatment plants, is influenced by the presence of a number of parameters that affect the activity of nitrifiers and, therefore, chemical speciation should be taken into consideration.