An "off-on" fluorescent nanosensor for the detection of cadmium ions based on APDC-etched CdTe/CdS/SiO2 quantum dots.

In this study, we have developed a novel fluorescent "OFF-ON" quantum dots (QDs) sensor based on CdTe/CdS/SiO2 cores. Ammonium pyrrolidine dithiocarbamate (APDC), ethylenediamine tetraacetic acid (EDTA), and 1,10-phenanthroline (Phen) served as potential chemical etchants. Among these three etchants, APDC exhibited the most pronounced quenching effect (94.06%). The APDC-etched CdTe/CdS/SiO2 QDs demonstrated excellent optical properties: the fluorescence of the APDC-etched CdTe/CdS/SiO2 QDs system (excitation wavelength: 365 nm and emission wavelength: 622 nm) was significantly and selectively restored upon the addition of cadmium ions (Cd2+) (89.22%), compared to 15 other metal ions. The linear response of the APDC-etched CdTe/CdS/SiO2 QDs was observed within the cadmium ion (Cd2+) concentration ranges of 0-20 µmol L-1 and 20-160 µmol L-1 under optimized conditions (APDC: 300 µmol L-1, pH: 7.0, reaction time: 10 min). The detection limit (LOD) of the APDC-etched CdTe/CdS/SiO2 QDs for Cd2+ was 0.3451 µmol L-1 in the range of 0-20 µmol L-1. The LOD achieved by the QDs in this study surpasses that of the majority of previously reported nanomaterials. The feasibility of using APDC-etched CdTe/CdS/SiO2 QDs for Cd2+ detection in seawater, freshwater, and milk samples was verified, with average recoveries of 95.27%-110.68%, 92%-106.47%, and 90.73%-111.60%, respectively, demonstrating satisfactory analytical precision (RSD ≤ 8.26).

Unveiling the therapeutic potential of a mutated paraoxonase 2 in diabetic retinopathy: Defying glycation, mitigating oxidative stress, ER stress and inflammation.

Paraoxonase 2 (PON2) is an intracellular anti-oxidant protein ubiquitously expressed in all cells and reduces reactive oxygen species, endoplasmic reticulum (ER) stress, further improves mitochondrial function and thereby shows anti-apoptotic function. In diabetes and its complications this PON gets glycated and becomes in effective. The PON activity is reported to be reduced in diabetic retinopathy and we have earlier showed Carboxy methyl lysine (AGE) decreased PON2 expression and activity in Human retinal endothelial cells (HREC) . In this study, we have designed and developed a mutated PON2 by in silico and in vitro approach which can resist glycation. Where in glycation-prone residues in PON2 was predicted using in silico analyses and a mutated PON2 was developed using in vitro site directed mutagenesis (SDM) assay mPON2 (mutant PON2-PON2-K70A) and its efficacy was compared with wPON2 (wild type PON2). CML glycated wPON2 and reduced its activity when compared with mPON2 in HREC confirmed by immunoprecipitation and in vitro experiments. Additionally, mPON2 interaction efficiency with its substrates was higher than wPON2 by insilico assay and demonstrated enhanced inhibition against CML-induced oxidative stress, ER stress, pro-inflammation, and mitochondrial fission than wPON2 by invitro assay. Further mPON2 showed increased inhibition of phosphorylation of NFĸB induced by CML. Our investigation establishes that the over expression of mPON2 in HREC can defy glycation and therefore mitigate ER stress and inflammation against CML than endogenous wPON2. These findings imply that mPON2 can be a beneficial therapeutic target against diabetic retinopathy.

New insights into the downregulation of cytochrome P450 2E1 via nuclear factor κB-dependent pathways in immune-mediated liver injury.

The extent of immune-mediated hepatic damage (such as in viral hepatitis) is characterised by the downregulation of cytochrome P450s (CYPs), a class of drug-metabolising enzymes. However, whether this downregulation aids liver cells in maintaining their homeostasis or whether the damage is aggravated remains largely unexplored. Herein, we evaluated the effects of phosphorylation mediated by the protein kinase C (PKC)/cAMP-response element binding protein (CREB) and nitration mediated by inducible nitric oxide synthase (iNOS) on the downregulation of CYP2E1 during immune-mediated liver injury. Additionally, we investigated the regulatory mechanism mediated by the nuclear factor κB (NF-κB). The rat model of immune-mediated liver injury was replicated by administering a single i.v. injection of Bacillus Calmette-Guerin (BCG, 125 mg/kg) vaccine and three i.p. injections of ammonium pyrrolidine dithiocarbamate (25, 50, 100 mg/kg/d, days 11, 12, and 13); blood was then collected on day 14. Subsequently, the livers were extracted to identify the different pharmacokinetic and biochemical indicators involved in the process. Our study reports new findings on the dependence between PKC-mediated CREB phosphorylation in the anti-inflammatory pathway and nitration emergency induced by iNOS in pro-inflammatory pathways in the NF-κB pathway. The interaction of these two pathways leads to the downregulation and recovery of CYP2E1, thus alleviating inflammation and nitration stress. Our results confirm that BCG-mediated downregulation of CYP2E1 is linked to iNOS-induced nitration and PKC/NF-κB-mediated CREB phosphorylation, and that NF-κB is an important molecular target in this process. These findings suggest that the downregulation of CYP2E1 may be an autonomous process characteristic of liver cells, helping them adapt to environmental changes, alleviate further hypoxia in inflamed tissues, and minimise exposure to toxic and harmful metabolites.

Minocycline and Pyrrolidine Dithiocarbamate Attenuate Hypertension via Suppressing Activation of Microglia in the Hypothalamic Paraventricular Nucleus.

Proinflammatory cytokines, reactive oxygen species and imbalance of neurotransmitters are involved in the pathophysiology of angiotensin II-induced hypertension. The hypothalamic paraventricular nucleus (PVN) plays a vital role in hypertension. Evidences show that microglia are activated and release proinflammatory cytokines in angiocardiopathy. We hypothesized that angiotensin II induces PVN microglial activation, and the activated PVN microglia release proinflammatory cytokines and cause oxidative stress through nuclear factor-kappa B (NF-κB) pathway, which contributes to sympathetic overactivity and hypertension. Male Sprague-Dawley rats (weight 275-300 g) were infused with angiotensin II to induce hypertension. Then, rats were treated with bilateral PVN infusion of microglial activation inhibitor minocycline, NF-κB activation inhibitor pyrrolidine dithiocarbamate or vehicle for 4 weeks. When compared to control groups, angiotensin II-induced hypertensive rats had higher mean arterial pressure, PVN proinflammatory cytokines, and imbalance of neurotransmitters, accompanied with PVN activated microglia. These rats also had more PVN gp91phox (source of reactive oxygen species production), and NF-κB p65. Bilateral PVN infusion of minocycline or pyrrolidine dithiocarbamate partly or completely ameliorated these changes. This study indicates that angiotensin II-induced hypertensive rats have more activated microglia in PVN, and activated PVN microglia release proinflammatory cytokines and result in oxidative stress, which contributes to sympathoexcitation and hypertensive response. Suppression of activated PVN microglia by minocycline or pyrrolidine dithiocarbamate attenuates inflammation and oxidative stress, and improves angiotensin II-induced hypertension, which indicates that activated microglia promote hypertension through activated NF-κB. The findings may offer hypertension new strategies.

Inhibition of pyrrolidine dithiocarbamate on transforming growth factor-beta 2 induced epithelial-mesenchymal transition in human lens epithelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the mechanism of pyrrolidine dithiocarbamate(PDTC)on transforming growth factor-beta 2(TGF-β2)-induced epithelial-mesenchymal transition(EMT)in human lens epithelial cells(LECs).METHODS: LECs were treated with various doses of PDTC chemicals following TGF-β2 caused EMT on these cells. Cell proliferation and lateral migration were discovered using the CCK-8 and cell scratch test. The markers of EMT, including E-cadherin, α-SMA and nuclear factor-κB(NF-κB)signaling pathway-related expression, were tested by Western Blot as well as the changes in the expression of the apoptosis-related proteins BAX, BCL-2, Caspase-3, and Cyclin D1.RESULTS: The proliferation and migration viability of cells in the TGF-β2 treated group was increased compared to the group without TGF-β2, and the expression of α-SMA increased whereas the E-cadherin expression decreased. With the effect of TGF-β2, NF-κB p65 and phosphorylated NF-κB p65 expression increased, the concentration of TGF-β2 that had the greatest capacity for proliferation and migration was 10 ng/mL(P<0.05). Mechanism study of PDTC-induced EMT reversal and apoptosis showed that cell viability and migratory capability were both significantly reduced after PDTC intervention; PDTC prevents IκB phosphorylation, thus inhibiting NF-κB nuclear translocation. Protein associated to the NF-κB signaling pathway, and protein expression of NF-κB/IκBα/p-IκBα/Iκκ-α/p-Iκκ-α was decreased(P<0.05), PDTC increased the expression of the pro-apoptotic protein BAX/Caspase-3, expression of the inhibitor of apoptosis protein BCL-2 and the cell cycle protein Cyclin D1 was reduced. The expression of NF-κB/IκB mRNA was reduced, expression of the apoptosis-related mRNA BAX increased, while BCL-2 reduced.CONCLUSION: The EMT in LECs cells induced by TGF-β2 can be significantly reversed by PDTC, which may be related to the decreased expression of NF-κB p65/IκB/Iκκ-α and activation of apoptosis-related protein. PDTC can reverse EMT by inhibiting NF-κB signaling pathway and induce apoptosis of abnormally proliferated cells, which will provide new potential therapeutic agents for posterior capsular opacification(PCO)treatment.

Genistein promotes M1 macrophage apoptosis and reduces inflammatory response by disrupting miR-21/TIPE2 pathway.

Cardiovascular diseases are a major cause of mortality, and vascular injury, a common pathological basis of cardiovascular disease, is deeply correlated with macrophage apoptosis and inflammatory response. Genistein, a type of phytoestrogen, exerts cardiovascular protective activities, but the underlying mechanism has not been fully elucidated. In this study, RAW264.7 cells were treated with genistein, lipopolysaccharide (LPS), nuclear factor-kappa B (NF-κB) inhibitor, and/or protein kinase B (AKT) agonist to determine the role of genistein in apoptosis and inflammation in LPS-stimulated cells. Simultaneously, high fat diet-fed C57BL/6 mice were administered genistein to evaluate the function of genistein on LPS-induced cardiovascular injury mouse model. Here, we demonstrated that LPS obviously increased apoptosis resistance and inflammatory response of macrophages by promoting miR-21 expression, and miR-21 downregulated tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) expression by targeting the coding region. Genistein reduced miR-21 expression by inhibiting NF-κB, then blocked toll-like receptor 4 (TLR4) pathway and AKT phosphorylation dependent on TIPE2, resulting in inhibition of LPS. Our research suggests that miR-21/TIPE2 pathway is involved in M1 macrophage apoptosis and inflammatory response, and genistein inhibits the progression of LPS-induced cardiovascular injury at the epigenetic level via regulating the promoter region of Vmp1 by NF-κB.

Pyrrolidine Dithiocarbamate Might Mitigate Radiation-Induced Heart Damage at an Early Stage in Rats.

Objective: Radiation-induced heart damage (RIHD) is becoming an increasing concern due to offsetting clinical benefits of radiotherapy to a certain extent. Pyrrolidine dithiocarbamate (PDTC) as an antioxidant has been implicated in cardioprotective effects. We aimed to investigate whether pyrrolidine dithiocarbamate could attenuate heart damage at an early stage post-irradiation and unveil the potential mechanisms. Methods: A total of 15 adult male Sprague-Dawley rats were randomized into the control, irradiation (IR), and PDTC plus irradiation (PDTC + IR) groups. Hearts were irradiated with a single fraction of 20.0 Gy. Rats received daily intraperitoneal injection of PDTC for 14 days. At the 14th day post-irradiation, echocardiography was performed, and rats were killed. Morphological damage was examined by hematoxylin-eosin (HE) stain and Masson's trichrome stain. The collagen volume fraction (CVF) was applied for semi-quantitative analysis. The protein levels were analyzed by Western blot and mRNA levels by quantitative real-time PCR. Results: No significant damage to systolic function of left ventricular was induced at an early stage post-irradiation. HE staining of cardiac tissue showed that the disordered arrangement of myocardial cells and abnormal cell infiltration were alleviated in the PDTC + IR group. The increased CVF in the irradiation group was inhibited in the PDTC + IR group (22.05 ± 2.64% vs. 9.99 ± 1.65%, p < 0.05). The protein levels of nuclear factor-kappa B (NF-κB), hypoxia-inducible factor-1α (HIF-1α), and COL-1 were downregulated after treatment with PDTC (p < 0.05), and there was a declining trend in the protein of the connective tissue growth factor (CTGF). The mRNA expression of NF-κB and HIF-1α in the PDTC plus irradiation group was lower than that in the irradiation group (p < 0.05), and there was a declining trend in the mRNA expression of the connective tissue growth factor and COL-1. Conclusion: PDTC alleviates myocardial cell disordered arrangement, abnormal cell infiltration, and pro-fibrotic change at an early stage in rats with radiation-induced heart damage. Such a protective effect is closely associated with the downregulation of NF-κB.

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.

Zinc Influx Restricts Enterovirus D68 Replication.

Enterovirus D68 (EV-D68) is a respiratory viral pathogen that causes severe respiratory diseases and neurologic manifestations. Since the 2014 outbreak, EV-D68 has been reported to cause severe complications worldwide. However, there are currently no approved antiviral agents or vaccines for EV-D68. In this study, we found that zinc ions exerted substantial antiviral activity against EV-D68 infection in vitro. Zinc salt treatment potently suppressed EV-D68 RNA replication, protein synthesis, and infectious virion production and inhibited cytopathic effects without producing significant cytotoxicity at virucidal concentrations (EC50=0.033mM). Zinc chloride (ZnCl2) treatment moderately inhibited EV-D68 attachment. Time-dose analysis of EV-D68 structural protein VP1 synthesis showed stronger suppression of VP1 in the culture medium than that in the cell lysates. Furthermore, a zinc ionophore, pyrrolidine dithiocarbamate, which can transport zinc ions into cells, also enhanced the anti-EV-D68 activity of ZnCl2 treatment. Taken together, our results demonstrated that the enhancement of zinc influx could serve as a powerful strategy for the therapeutic treatment of EV-D68 infections.

Simultaneous amelioration of diabetic ocular complications in lens and retinal tissues using a non-invasive drug delivery system.

Topically administered delivery systems for ophthalmic applications have been studied for the treatment of anterior or posterior eye diseases. However, simultaneous treatment of both anterior and posterior eye diseases has not been explored. In this study, we fabricated a topically administrable polymeric nanoparticle (NP)- based delivery system consisting of pluronic®F-68 shell and polycaprolactone core for the simultaneous treatment of both anterior and posterior eye diseases. These NPs were loaded with pyrrolidine dithiocarbamate (PDTC) or triamcinolone acetonide (TA) separately. The drug loading in NPs was optimized to initially achieve a moderate burst release of PDTC followed by slow and sustained release of both PDTC and TA. The resultant delivery system was studied for its in vivo efficacy in a diabetic retinopathy (DR) and cataract rat model. The results demonstrated that administration of PDTC NPs + TA NPs minimized oxidative stress in lens as evidenced by reduced levels of protein carbonyls and malondialdehyde, and, ameliorated DR complications in retina as evidenced by reduced expression of hypoxia inducible factor-1α along with a reduction in number of neovascular tufts and acellular capillaries. Therefore, delivery of PDTC and TA using PCL-PF68 NPs could be a useful approach for simultaneous treatment of diabetic cataract and DR.

Protective effect of pyrrolidine dithiocarbamate against methotrexate-induced testicular damage.

The aim of the study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) against methotrexate (MTX)-induced testicular damage in rats. Forty Wistar albino male rats were divided into equally four groups: Control group (saline solution, IP), PDTC group (100 mg/kg PDTC,IP, 10 days), MTX group (20 mg/kg MTX, IP, single dose, on the 6th day) and MTX + PDTC group (100 mg/kg PDTC, IP, 10 days and 20 mg/kg MTX, IP, single dose, on the 6th day). After 10 days, testicular tissues were excised for morphometric, histological and immunohistochemical evaluations. Serum testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and prokineticin 2 (PK2) levels were determined. Body and testicular weights were measured. Testicular damage was assessed by histological evaluation. Nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2) and PK2 immunoreactivities were evaluated by HSCORE. Body and testicular weights, serum FSH, LH, testosterone levels, seminiferous tubule diameter and germinal epithelial thickness were significantly decreased in the MTX group. However, serum PK2 level, histologically damaged seminiferous tubules and interstitial field width were significantly increased. Additionally, there was an increase in NFkB and PK2 immunoreactivity, whereas there was a significant decrease in Nrf2 immunoreactivity. PDTC significantly improved hormonal, morphometric, histological and immunohistochemical findings. Taken together, we conclude that PDTC may reduce MTX-induced testicular damage via NFkB, Nrf2 and PK2 signaling pathways.

Developing membrane-derived nanocarriers for ex vivo therapy of homologous breast cancer cells.

Aim: The primary aim of this study was to develop biomimetic nanocarriers for specific homologous targeting of the anticancer drugs ammonium pyrrolidine dithiocarbamate (PDTC) and doxorubicin. Methods: Membranous nanovesicles were synthesized from a breast cancer cell line (MCF7) by syringe extrusion process and were loaded with PDTC and doxorubicin. Besides their abilities for self-homing, the drug-loaded nanovesicles showed anti-cell proliferative effects via the generation of reactive oxygen species. Results: The nanovesicles demonstrated efficient internalization via homologous targeting. Delivery of PDTC showed a higher killing effect for homologous cell targeting than other cell types. Experimental results demonstrated increased antiproliferative potency of PDTC, which induced apoptosis via reactive oxygen species generation. Conclusion: The developed membrane-derived nanocarrier is an attractive biocompatible system for ex vivo targeted drug delivery.

Possible Therapeutic Options for Complex Regional Pain Syndrome.

Complex regional pain syndrome (CRPS) describes an array of painful conditions that are characterized by continuing regional pain. CRPS comprises severe and inappropriate pain in cases of complete recovery after trauma. Research on the pharmacological treatment of CRPS, however, has not been well investigated. In this study, we compared the pain relief effects of different drugs (URB597, pyrrolidine dithiocarbamate, and hydralazine) in a rat model of chronic post-ischemic pain-induced CRPS. After drug injection, CRPS-induced mechanical allodynia was significantly recovered. After three repetitive drug injections, mechanical sensitivity generally improved as hyper-nociception subsided. Reduced Nav1.7 expression at dorsal root ganglions (DRGs) was observed in the drug treatment groups. Neural imaging analysis revealed decreased neural activity for each drug treatment, compared to vehicle. In addition, treatments significantly reduced IL-1ß, IL-6, and TNFα expression in DRGs. These results indicated that drugs could reduce the expression of inflammatory factors and alleviate the symptoms of chronic post-ischemic pain-induced CRPS.

Determination of arsenic species using functionalized ionic liquid by in situ dispersive liquid-liquid microextraction followed by atomic absorption spectrometry.

Synthesis and application of a task-specific ionic liquids (TSILs) as extracting solvents or chelating agents in dispersive liquid-liquid micro-extraction (DLLME) was evaluated. The developed method was based on the use of an ammonium pyrrolidine dithiocarbamate (APDC) bonded ionic liquid for chelation with As(III), followed by conversion of the As(III) chelated TSIL to a hydrophobic ionic liquid using KPF6 as an anion-exchange reagent. As(V) was reduced to As(III), using a 2/1 w/w blend of KI and Na2S2O3 and then the total amount of As was measured through ETAAS analysis. Under optimal conditions, linear dynamic ranges of 0.2-15 ng mL-1 and 0.2-20 ng mL-1 were observed in the determination of As(III) and total As respectively. The relative standard deviations (RSD%, n = 5) for the determination of As(III) (10 ng mL-1) was 3.2% and the limits of detection and quantitation were determined to be 0.01 ng mL-1 and 0.0.034 ng mL-1; respectively.

Posttranslational modifications as therapeutic targets for intestinal disorders.

A variety of biological processes are regulated by posttranslational modifications. Posttranslational modifications including phosphorylation, ubiquitination, glycosylation, and proteolytic cleavage, control diverse physiological functions in the gastrointestinal tract. Therefore, a better understanding of their implications in intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, celiac disease, and colorectal cancer would provide a basis for the identification of novel biomarkers as well as attractive therapeutic targets. Posttranslational modifications can be common denominators, as well as distinct biomarkers, characterizing pathological differences of various intestinal diseases. This review provides experimental evidence that identifies changes in posttranslational modifications from patient samples, primary cells, or cell lines in intestinal disorders, and a summary of carefully selected information on the use of pharmacological modulators of protein modifications as therapeutic options.

Proliferation and activation of vascular smooth muscle cells induced by activated complement alternative pathway and intervention study / 中国药理学通报

Aim To study the effect of proliferation and activation of vascular smooth muscle cells (VSMCs) induced by activated the complement alternative pathway and intervention. Methods Normal human plasma was specifically activated the complement alternative pathway by incubated with cobra venom factor (CVF). Exposed VSMCs to the activated complement products, the change of cell morphology and the cell viability were assayed by inverted phase contrast microscope and MTT method, respectively. The supernatant was assayed for expression of E-selectin, ICAM-1 and VCAM-1 by using ELISA reagent kits. The protein expression levels of p-NF-kB p65, NF-kB p65 and IKK were assayed by Western blot. The nucleus transcriptional activity of NF-ΚB p65 was tested by the dual luciferase reporter assay system. Pyrrolidine dithiocarbamate (PDTC) was used to intervene the proliferation and activation of VSMCs. Results VSMCs were activated and induced to proliferation after exposed to the products of activated complement alternative pathway. The expressions of E-selectin, VCAM-1 and ICAM-1 were up-regulated. The contents of ICAM-1 and VCAM-1 reached the peak at 6 h and the E-selectin increased significantly at 12 h. Meanwhile, the phosphorylation level of NF-ΚB p65, nucleus transcriptional activity of NF-ΚB p65 and the protein expression of IKK and N F - Κ B p65 increased. The above mentioned changes were clearly inhibited by PDTC. Conclusions The activated complement alternative pathway can initiate proliferation and activation of VSMCs, and its mechanism goes hand in hand with activation of N F - Κ B signaling pathway. PDTC, a specific inhibitor of N F - K B, can effectively inhibit the proliferation and activation of VSMCs.

Protective and therapeutic effects of pyrrolidine dithiocarbamate in a rat tongue cancer model created experimentally using 4-nitroquinoline 1-oxide.

BACKGROUND: Tongue tumors, which are oropharyngeal tumors, are increasing in frequency. Pyrrolidine dithiocarbamate (PDTC) is a powerful antioxidant and antitumoral agent. OBJECTIVES: To evaluate the protective and therapeutic effects of PDTC in a tongue cancer model induced with 4-nitroquinoline 1-oxide (4-NQO). MATERIAL AND METHODS: We included 40 rats in the trial and assigned them randomly to 5 groups. Group 1 (cancer, n = 7): 4-NQO (0-12 weeks); group 2 (protection, n = 8): 4-NQO (0-12 weeks) + PDTC (300 mg/kg/day, 0-12 weeks); group 3 (therapy-high dose, n = 10): 4-NQO (0-12 weeks) + PDTC (600 mg/kg/day, weeks 12-30); group 4 (therapy-low dose, n = 10): 4-NQO (0-12 weeks) + PDTC (300 mg/kg/day, weeks 12-30); and group 5 (control). Cardiac blood samples were taken to analyze oxidative stress parameters (total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)). Histopathological assessment was performed under a light microscope. RESULTS: The results of the histopathological assessment showed that the model we used in group 1 was successful, which was consistent with the literature. The PDTC dose administered in group 2 could not prevent tumor formation. Group 3 demonstrated that PDTC in high doses is effective as a therapeutic agent. Group 4 indicated that PDTC in low doses has no therapeutic effect. The results of the biochemical assessment showed that in group 3, TOS and OSI values were significantly lower than in groups 1, 2 and 4. No significant difference was found in the TOS and OSI values between groups 5 and 3. CONCLUSIONS: Our study demonstrated histopathologically that in an experimentally generated tongue cancer model, application of 600 mg/kg/day of PDTC led to a significant reduction in the size of the tumor. This was supported by the biochemical parameters.

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.

Pyrrolidine dithiocarbamate reduces alloxan-induced kidney damage by decreasing nox4, inducible nitric oxide synthase, and metalloproteinase-2.

We examined the effect of the NFκB inhibitor pyrrolidine-1-carbodithioic acid (PDTC) on inducible nitric oxide synthase (iNOS), matrix metalloproteinase-2 (MMP-2) activity, and oxidative and inflammatory kidney damage in alloxan-induced diabetes. Two weeks after diabetes induction (alloxan-130 mg/kg), control and diabetic rats received PDTC (100 mg/kg) or vehicle for 8 weeks. Body weight, glycemia, urea, and creatinine were measured. Kidney changes were measured in hematoxylin/eosin sections and ED1 by immunohistochemistry. Kidney thiobarbituric acid reactive substances (TBARS), superoxide anion (O2-), and nitrate/nitrite (NOx) levels, and catalase and superoxide dismutase (SOD) activities were analyzed. Also, kidney nox4 and iNOS expression, and NFkB nuclear translocation were measured by western blot, and MMP-2 by zymography. Glycemia and urea increased in alloxan rats, which were not modified by PDTC treatment. However, PDTC attenuated kidney structural alterations and macrophage infiltration in diabetic rats. While diabetes increased both TBARS and O2- levels, PDTC treatment reduced TBARS in diabetic and O2- in control kidneys. A decrease in NOx levels was found in diabetic kidneys, which was prevented by PDTC. Diabetes reduced catalase activity, and PDTC increased catalase and SOD activities in both control and diabetic kidneys. PDTC treatment reduced MMP-2 activity and iNOS and p65 NFκB nuclear expression found increased in diabetic kidneys. Our results show that the NFκB inhibitor PDTC reduces renal damage through reduction of Nox4, iNOS, macrophages, and MMP-2 in the alloxan-induced diabetic model. These findings suggest that PDTC inhibits alloxan kidney damage via antioxidative and anti-inflammatory mechanisms.

Silencing PEG3 inhibits renal fibrosis in a rat model of diabetic nephropathy by suppressing the NF-κB pathway.

As paternally expressed gene 3 (PEG3), which can activate NF-κB pathway, plays an important role in the development of renal fibrosis in diabetic nephropathy (DN), the present study aimed to investigate the interaction of PEG3 and the NF-κB pathway on renal fibrosis in a DN model. Following the induction of the rat model of DN, a series of experiments were used to measure serum creatinine (Scr), blood urea nitrogen (BUN), urine protein for 24 h (UP24 h), proliferation of renal fibroblasts, positive expression of PEG3, Collagen I and Collagen II protein, the activity of NF-κB, collagen fiber expression and the FSP1+ cell ratio (fibroblast marker, reflecting renal fibrosis). Silencing of PEG3 or inhibition of the NF-κB pathway decreased the levels of Scr, BUN, and UP24 h, down-regulated Collagen I protein and up-regulated Collagen II protein. These treatments also down-regulated the expression of PEG3, NF-κB, Vimentin, α-SMA, FN, caspase-3 and FSP1 and the extents of IκBα, inhibitor of kappa B (IκB) kinase ß (IKKß), and NF-κB p65 phosphorylation while that of E-cadherin was up-regulated, and the ratio of FSP1+ cells was decreased. Taken together, these results showed that silencing of PEG3 inhibited the NF-κB pathway, thereby alleviating renal fibrosis in DN, thus presenting PEG3 as a potential therapeutic target in renal fibrosis in DN.