Pyrrolidine dithiocarbamate protects pancreatic ß-cells from oxidative damage through regulation of FoxO1 activity in type 2 diabetes rats.

Pyrrolidine dithiocarbamate (PDTC) can lower the blood glucose level and improve the insulin sensitivity in diabetic rats. However, the mechanisms underlying this effect of PDTC treatment in diabetic rats remained uncertain. In this study, we evaluated the mechanisms by which PDTC conferred protection against oxidative damage to pancreatic islet ß-cells in rats with experimental type 2 diabetes mellitus (DM). DM in the rats was elicited by long-term high-fat diet accompanied with a single intraperitoneal (i.p.) injection of a low dose of streptozotocin. After a 7-day administration of PDTC (50 mg/kg/day i.p.), blood glucose levels were measured and pancreatic tissues were collected for the determination of various biochemical and enzymatic activities using immunohistochemistry, immunofluorescence, and western blot techniques. The percentage of apoptotic pancreatic islet ß-cells was detected by flow cytometry. The results showed that diabetic rats had elevated blood glucose levels and insulin resistance, accompanied with an increase in malondialdehyde content, nitrotyrosine production, and inducible nitric oxide synthase expression. A decrease in superoxide dismutase and glutathione peroxidase activities was also observed in DM rats, culminating with elevated ß-cell apoptosis. PDTC treatment significantly reduced the oxidative damage and the ß-cell apoptosis, and also increased the insulin production through down-regulating FoxO1 acetylation and up-regulating nuclear PDX-1 level. These data suggested that PDTC can protect islet ß-cells from oxidative damage and improve insulin production through regulation of PDX-1 and FoxO1 in a DM rat model.

Rapid and simple As(III) quantification using a turbidimetric test for the monitoring of microbial arsenic bio-transformation.

A turbidimetric test for rapid quantification of As(III) (detection limit of 3 mg/L, quantification range of 10-100 mg/L) in liquid growth medium was developed for assessing and monitoring microbial As(III)-oxidizing and As(V)-reducing activities. This test is based on As(III) chelation with pyrrolidine dithiocarbamate followed by spectrometric measurement of absorbance, and was validated by comparison with AAS quantification of As after As(III)/As(V) separation.

Effects of 10 weeks of regular running exercise with and without parallel PDTC treatment on expression of genes encoding sarcomere-associated proteins in murine skeletal muscle.

Physical exercise can induce various adaptation reactions in skeletal muscle tissue, such as sarcomere remodeling. The latter involves degradation of damaged sarcomere components, as well as de novo protein synthesis and sarcomere assembly. These processes are controlled by specific protease systems in parallel with molecular chaperones that assist in folding of newly synthesized polypeptide chains and their incorporation into sarcomeres. Since acute exercise induces oxidative stress and inflammation, leading to activation of the transcription factor NFκB (nuclear factor kappa B), we speculated that this transcription factor might also play a role in the regulation of long-term adaptation to regular exercise. Thus, we studied skeletal muscle adaptation to running exercise in a murine model system, with and without parallel treatment with the NFκB-inhibitory, anti-oxidant and anti-inflammatory drug pyrrolidine dithiocarbamate (PDTC). In control mice, 10 weeks of uphill (15° incline) treadmill running for 60 min thrice a week at a final speed of 14 m/min had differential, but only minor effects on many genes encoding molecular chaperones for sarcomere proteins, and/or factors involved in the degradation of the latter. Furthermore, there were marked differences between individual muscles. PDTC treatment modulated gene expression patterns as well, both in sedentary and exercising mice; however, most of these effects were also modest and there was little effect of PDTC treatment on exercise-induced changes in gene expression. Taken together, our data suggest that moderate-intensity treadmill running, with or without parallel PDTC treatment, had little effect on the expression of genes encoding sarcomere components and sarcomere-associated factors in murine skeletal muscle tissue.

The study on inflammatory mechanism of cognitive dysfunction induced by 1-bromopropane in rats / 中华行为医学与脑科学杂志

Objective:To observe the role of neuroinflammation in cognitive dysfunction induced by 1-bromopropane (1-BP) in rats.Methods:Male Wistar rats were randomly divided into control group, 1-BP group, pyrrolidine dithiocarbamate(PDTC)+ 1-BP group and PDTC group, with 15 rats in each group. Rats in 1-BP group and PDTC+ 1-BP group were given 800 mg / kg 1-BP by gavage, and rats in control group and PDTC group were given equal volume corn oil once a day for 12 days; rats in PDTC group and PDTC+ 1-BP group were intraperitoneally injected with 100 mg / kg PDTC 30 minutes after gavage, while rats in control group and 1-BP group were injected with equal volume of normal saline once a day for 12 days.From the 7th to 12th day of the experiment, ten rats in each group were randomly selected and subjected to Morris water maze test for detect the cognitive function. In the positioning navigation test, the learning ability of rats was evaluated by the escape latency and total swimming distance respectively. In the space exploration experiment, the memory ability of experimental animals was evaluated by the number of times crossing the target platform. After the experiment, ten rats were sacrificed, the cerebral prefrontal cortex was harvested. The cytosolic and nuclear NF-κB expression and phosphorylation were detected by Western blot, the mRNA levels of TNF-α and IL-1β were detected by qRT-PCR. After cardiac perfusion fixation, the brains of 5 rats were taken to make frozen sections for immunohistochemical staining and Nissl staining. SPSS 20.0 software was used for statistical analysis, repetitive measurement deviation analysis was used for the analysis of the swimming distance and the escape latency in positioning navigation test, One-way ANOVA was used for the analysis of the number of times crossed the target platform in spatial probe test and other data. Tukey's test was used for Post hoc comparison.Results:The results of Morris water maze showed that there was significant interaction between group and training time in the total swimming distance of rats in the four groups ( F=3.762, P<0.05). Simple effect analysis showed that the total swimming distance of 1-BP group in 1-4 days were longer than those of control group (all P<0.05), while the total swimming distance of PDTC+ 1-BP group in 1-4 days were shorter than those of 1-BP group (all P<0.05). There was significant interaction between group and training time in the escape latency among the four groups ( F=6.541, P<0.01). The escape latencies of 1-BP group in 1-4 days were longer than those of control group (all P<0.05), while the escape latencies of PDTC+ 1-BP group in 1-4 days were shorter than those of 1-BP group (all P<0.05). The results of space exploration experiment showed that there was significant difference in the number of crossing the platform among the four groups ( F=75.333, P<0.01). The number of crossing the platform (1.08±0.29) in 1-BP group was lower than that in the control (3.35±0.05) ( P<0.01). The number of crossing the platform (1.95±0.26) in PDTC+ 1-BP group was higher than that in 1-BP group ( P<0.01). It had significant difference both in the cytoplasm and in the nucleus of the NF-κB protein level in prefrontal cortex among rats of the four groups ( F=20.865, 23.877, both P<0.01). The levels of NF-κB in cytoplasm and nucleus of rats in 1-BP group were both higher than those in control group (cytoplasm: (177.3±32.1)%, (100.0±8.4)%, P<0.01; nucleus: ( 173.2±27.1)%, (100.0±8.4)%, P<0.01). While the levels of NF-κB in cytoplasm and nucleus of 1-BP+ PDTC group were both lower than those of 1-BP group (cytoplasm: (148.7±22.0)%, (177.3±32.1)%, P<0.01; nucleus: (149.7±18.8)%, (173.2±27.1)%, P<0.01). The results of qRT-PCR showed that there were significant differences in the mRNA levels of TNF-α and IL-1β in the prefrontal cortex among the four groups ( F=17.464, 17.382, both P<0.01). The levels of TNF-α and IL-1β mRNA in 1-BP group were higher than those in control group (both P<0.05), and the levels of TNF-α and IL-1β mRNA in PDTC+ 1-BP group were both lower than those in 1-BP group (both P<0.05). The results of immunohistochemistry showed that compared with the control group, the number of microglia and astrocytes in the 1-BP group increased (microglia: (158.30±9.68), (110.20±16.30), P<0.05; astrocytes: (122.76±4.35), (80.24±6.96), P<0.05), and the morphology was also activated, with light staining and reduced number of Nissl bodies in neurons.The number of microglia and astrocytes in PDTC + 1-BP group was lower than that in 1-BP group (microglia: (131.70±14.67), (158.30±9.68), P<0.05; astrocytes: (101.54±4.55), (122.76±4.35), P<0.05), and the Nissl body staining of neurons was significantly deepened. Conclusion:NF-κB signaling pathway might be the key mechanism of 1-BP neurotoxicity. PDTC intervention could significantly improve the neuroinflammatory response and behavioral disorders of experimental animals intoxicated with 1-BP.

Pyrrolidine dithiocarbamate,a inhibitor of NF-?B,enhances chemosensitivity of ovarian cancer cells to cisplatin / 中国肿瘤生物治疗杂志

Objective:To determine the promoting effect of pyrrolidine dithiocarbamate(PDTC),an inhibitor of NF-?B,on the sensitivity of human ovarian cancer cell line SKOV-3 to chemoagent cisplatin and the possible mechanisms.Methods:SKOV-3 cells were treated with various concentrations of cisplatin and PDTC combination for different periods.Then the growth inhibition of SKOV-3 cells were observed by MTT assay,expression of I-?B? and P65 protein by Western blotting assay,and apoptosis of cells by flow cytometry.Results:Separate application of both cisplatin(0.1-10 ?g/ml)and PDTC(10-40 ?mol/L L)significantly inhibited the growth of SKOV-3 cells and caused cell apoptosis(P