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Scientific Reports Sep 2015We demonstrate the role of molecular switching of TrkA/p75(NTR) signaling cascade in organophosphate pesticide-Monocrotophos (MCP) induced neurotoxicity in stem cell...
We demonstrate the role of molecular switching of TrkA/p75(NTR) signaling cascade in organophosphate pesticide-Monocrotophos (MCP) induced neurotoxicity in stem cell derived cholinergic neurons and in rat brain. Our in-silico studies reveal that MCP followed the similar pattern of binding as staurosporine and AG-879 (known inhibitors of TrkA) with TrkA protein (PDB ID: 4AOJ) at the ATP binding sites. This binding of MCP to TrkA led to the conformational change in this protein and triggers the cell death cascades. The in-silico findings are validated by observing the down regulated levels of phosphorylated TrkA and its downstream molecules viz., pERK1/2, pAkt and pCREB in MCP-exposed cells. We observe that these MCP induced alterations in pTrkA and downstream signaling molecules are found to be associated with apoptosis and injury to neurons. The down-regulation of TrkA could be linked to increased p75(NTR). The in-vitro studies could be correlated in the rat model. The switching of TrkA/p75(NTR) signaling plays a central role in MCP-induced neural injury in rBNSCs and behavioral changes in exposed rats. Our studies significantly advance the understanding of the switching of TrkA/p75(NTR) that may pave the way for the application of TrkA inducer/p75(NTR) inhibitor for potential therapeutic intervention in various neurodegenerative disorders.
Topics: Animals; Apoptosis; Behavior, Animal; Brain; Cell Differentiation; Cells, Cultured; Cholinesterase Inhibitors; Insecticides; Models, Molecular; Molecular Conformation; Molecular Docking Simulation; Monocrotophos; Nerve Tissue Proteins; Neural Stem Cells; Neurons; Rats; Receptor, trkA; Receptors, Growth Factor; Receptors, Nerve Growth Factor; Signal Transduction; Structure-Activity Relationship
PubMed: 26370177
DOI: 10.1038/srep14038 -
Journal of Insect Science (Online) Feb 2014The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in nine populations of the common pistachio psyllid, Agonoscena pistaciae Burckhardt...
The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in nine populations of the common pistachio psyllid, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), were investigated in Kerman Province, Iran. Nine A. pistaciae populations were collected from pistachio orchards, Pistacia vera L. (Sapindales: Anacardiaceae), located in Rafsanjan, Anar, Bam, Kerman, Shahrbabak, Herat, Sirjan, Pariz, and Paghaleh regions of Kerman province. The previous bioassay results showed these populations were susceptible or resistant to phosalone, and the Rafsanjan population was most resistant, with a resistance ratio of 11.3. The specific activity of AChE in the Rafsanjan population was significantly higher than in the susceptible population (Bam). The affinity (K(M)) and hydrolyzing efficiency (Vmax) of AChE on acetylthiocholine iodide, butyrylthiocholine iodide, and propionylthiocholine odide as artificial substrates were clearly lower in the Bam population than that in the Rafsanjan population. These results indicated that the AChE of the Rafsanjan population had lower affinity to these substrates than that of the susceptible population. The higher Vmax value in the Rafsanjan population compared to the susceptible population suggests a possible over expression of AChE in the Rafsanjan population. The in vitro inhibitory effect of several organophosphates and carbamates on AChE of the Rafsanjan and Bam populations was determined. Based on I50, the results showed that the ratios of AChE insensitivity of the resistant to susceptible populations were 23 and 21.7-fold to monocrotophos and phosphamidon, respectively. Whereas, the insensitivity ratios for Rafsanjan population were 0.86, 0.8, 0.78, 0.46, and 0.43 for carbaryl, eserine, propoxur, m-tolyl methyl carbamate, and carbofuran, respectively, suggesting negatively correlated sensitivity to organophosphate-insensitive AChE. Therefore, AChE from the Rafsanjan population showed negatively correlated sensitivity, being insensitive to phosphamidon and monocrotophos and sensitive to N-methyl carbamates.
Topics: Acetylcholinesterase; Acetylthiocholine; Animals; Butyrylthiocholine; Hemiptera; Insecticide Resistance; Insecticides; Iran; Organothiophosphorus Compounds; Thiocholine
PubMed: 25373165
DOI: 10.1093/jis/14.1.18 -
PloS One 2014Our recent study showed that monocrotophos (MCP) pesticide disrupted the hypothalamic-pituitary-thyroid (HPT) axis in male goldfish (Carassius auratus); however, the...
Monocrotophos pesticide decreases the plasma levels of total 3,3',5-triiodo-l-thyronine and alters the expression of genes associated with the thyroidal axis in female goldfish (Carassius auratus).
Our recent study showed that monocrotophos (MCP) pesticide disrupted the hypothalamic-pituitary-thyroid (HPT) axis in male goldfish (Carassius auratus); however, the effects of MCP on the thyroid system in female goldfish are remain unclear. In the present study, plasma thyroid hormone (TH) and thyroid-stimulating hormone (TSH) levels were evaluated in female goldfish exposed to 0.01, 0.10, and 1.00 mg/L of 40% MCP-based pesticide for 21 days in a semi-static exposure system. Expression profiles of HPT axis-responsive genes, including transthyretin (ttr), deiodinases (d1, d2, and d3), tshβ, thyrotropin-releasing hormone (trh), and corticotrophin-releasing hormone (crh), were determined. The results indicated that MCP decreased the plasma levels of total 3,3',5-triiodo-l-thyronine (TT3) and the ratio of TT3 to total 3,3',5,5'-l-thyroxine (TT4), and induced alternative expression of TH-related genes. Exposure to 0.01 and 0.10 mg/L MCP pesticide resulted in the up-regulation of ttr mRNA. The reduction of plasma TT3 levels was partly attributed to an increase in the metabolism of T3 in the liver, as revealed by the highly elevated hepatic d1 and d3 mRNA levels in the MCP treatment groups, and the expression of hepatic d3 showed a negative correlation with the plasma TT3/TT4 levels in females. Moreover, the plasma TSH levels were lower in females exposed to 0.01 and 0.10 mg/L MCP pesticide, whereas the up-regulation of tshβ mRNA levels was compensated by the decreased plasma TT3 levels. These results indicated that MCP had the potential to influence several pathways of HPT axis homeostasis in female goldfish.
Topics: Animals; Brain; Corticotropin-Releasing Hormone; Female; Goldfish; Iodide Peroxidase; Kidney; Liver; Monocrotophos; Pesticides; Prealbumin; RNA, Messenger; Thyroid Gland; Thyroid Hormones; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine
PubMed: 25268935
DOI: 10.1371/journal.pone.0108972 -
Toxicology International Jan 2014The present study was undertaken to evaluate the toxic effects of monocrotophos, a widely used organophosphorus pesticide, on Lamellidens marginalis with a wide battery...
The present study was undertaken to evaluate the toxic effects of monocrotophos, a widely used organophosphorus pesticide, on Lamellidens marginalis with a wide battery of biomarkers consisting of AchE inhibition, lipid peroxidation, the levels of antioxidant enzymes, and histopathological changes. Animals were exposed to monocrotophos (52.36 mg/l) for four days. Malondialdehyde (MDA) values were measured as index of oxidation while Superoxide dismutase (SOD), Catalase (CAT), Glutathione s-Transferase (GST), and Glutathione-Reductase (GR) were measured as index of an antioxidant status. After exposure, a significant reduction of the capability to neutralize radicals was observed. Histopathological changes, such as fibrosis in gill filaments and hypertrophy in mucous cells of foot tissue, were observed after treatment. In a second series of experiment, exposed animals were thereafter transferred to clean water and kept in it up to 28 days to assess the recovery pattern. Significant recovery is observed in AchE and antioxidant enzymes. Oxidative damage observed after acute exposure indicate that mussels faced an oxidative challenge but were able to counteract, as values of anti-oxidants returned near to control values after 28 days. Altered activities in anti-oxidant enzymes due to stress recovered well after 28 days in gill and muscles as compared to foot and mantle. Overall results suggested that oxidative markers are highly sensitive and could be profitably applied to freshwater mussels for environmental quality assessment in freshwater.
PubMed: 24748735
DOI: 10.4103/0971-6580.128793 -
PloS One 2014The expression and metabolic profile of cytochrome P450s (CYPs) is largely missing in human brain due to non-availability of brain tissue. We attempted to address the...
The expression and metabolic profile of cytochrome P450s (CYPs) is largely missing in human brain due to non-availability of brain tissue. We attempted to address the issue by using human brain neuronal (SH-SY5Y) and glial (U373-MG) cells. The expression and activity of CYP1A1, 2B6 and 2E1 were carried out in the cells exposed to CYP inducers viz., 3-methylcholanthrene (3-MC), cyclophosphamide (CPA), ethanol and known neurotoxicant- monocrotophos (MCP), a widely used organophosphorous pesticide. Both the cells show significant induction in the expression and CYP-specific activity against classical inducers and MCP. The induction level of CYPs was comparatively lower in MCP exposed cells than cells exposed to classical inducers. Pre-exposure (12 h) of cells to classical inducers significantly added the MCP induced CYPs expression and activity. The findings were concurrent with protein ligand docking studies, which show a significant modulatory capacity of MCP by strong interaction with CYP regulators-CAR, PXR and AHR. Similarly, the known CYP inducers- 3-MC, CPA and ethanol have also shown significantly high docking scores with all the three studied CYP regulators. The expression of CYPs in neuronal and glial cells has suggested their possible association with the endogenous physiology of the brain. The findings also suggest the xenobiotic metabolizing capabilities of these cells against MCP, if received a pre-sensitization to trigger the xenobiotic metabolizing machinery. MCP induced CYP-specific activity in neuronal cells could help in explaining its effect on neurotransmission, as these CYPs are known to involve in the synthesis/transport of the neurotransmitters. The induction of CYPs in glial cells is also of significance as these cells are thought to be involved in protecting the neurons from environmental insults and safeguard them from toxicity. The data provide better understanding of the metabolizing capability of the human brain cells against xenobiotics.
Topics: Biocatalysis; Brain; Cell Line, Tumor; Cytochrome P-450 Enzyme System; Gene Expression Regulation, Enzymologic; Humans; Molecular Docking Simulation; Monocrotophos; Neurotoxins; Protein Conformation; Transcription, Genetic; Xenobiotics
PubMed: 24663500
DOI: 10.1371/journal.pone.0091946 -
Toxicology International May 2013Inducible expressions cytochrome P450s (CYPs) against environmental chemicals in brain tissues of experimental animals is well-documented. However, the precise role of...
Inducible expressions cytochrome P450s (CYPs) against environmental chemicals in brain tissues of experimental animals is well-documented. However, the precise role of specific brain cell type in the metabolism of different class of xenobiotics has not been explored adequately. We study the expression of selected CYPs (1A1/1A2, 2B1/2B2, 2E1) in primary cultures of rat brain neuronal and glial cell exposed to an organophosphate pesticide-monocrotophos (MCP), a known neurotoxicant. The cultured neurons and glial cells express significant expression of CYP1A1, 2B2 and 2E1 isoenzymes, where the levels were comparatively higher in neuronal cells. Neuronal cells exhibited greater induction of CYP2E1 against MCP exposure, while glial cells were having more vulnerability for CYP1A and 2B isoenzymes. Similarly, cells were showing substrate specific responses against the specific inducers of CYPs, that is, ethanol (2E1), cyclophosphamide (2B1/2B2), 3-methylcholanthrene (1A1/1A2). The altered expression and activity of selected CYPs in cultured neuronal and glial cells could be helpful in explaining the association between MCP-induced neurotoxicity/metabolism and synthesis or transport of the neurotransmitters. The induction of CYPs in glial cells may also have significance as these cells are thought to be involved in protecting the neurons from environmental insults and safeguard them from toxicity. The differential expression pattern of CYPs in neuronal and glial cells exposed to MCP also indicate the selective sensitivity of these cells against the xenobiotics, hence suggested their suitability as tool to screen neurotoxicity potential of variety of xenobiotics.
PubMed: 24082512
DOI: 10.4103/0971-6580.117264 -
Toxicology International Jan 2013The restorative potential of trans-resveratrol (RV) was investigated in a rat neuronal cell line (PC12) exposed to organophosphate pesticide-monocrotophos (MCP). RV...
The restorative potential of trans-resveratrol (RV) was investigated in a rat neuronal cell line (PC12) exposed to organophosphate pesticide-monocrotophos (MCP). RV shows significant protection against MCP-induced alterations in PC12 cells by restoration of oxidative stress-mediated apoptosis and cytotoxicity. RV treatment significantly reduced reactive oxygen species (ROS) production and lipid peroxidation, and also restored glutathione levels and mitochondrial membrane potential, in cells receiving MCP. Restoration of markers such as cytochrome c, Bax, Bcl-2 and caspase-3 also confirms the effectiveness of RV against MCP-induced, mitochondria-mediated apoptosis in PC12 cells. The data identify the protective/restorative potential of RV against MCP-induced neuronal damages by affecting ROS production and the level of antioxidant defence enzymes.
PubMed: 23833438
DOI: 10.4103/0971-6580.111571 -
Bioscience, Biotechnology, and... 2013The present study aimed at a comparative characterization of two distinct extracellular monocrotophos hydrolases, from Penicillium aculeatum ITCC 7980.10 (M3) and... (Comparative Study)
Comparative Study
Comparative purification and characterization of two distinct extracellular monocrotophos hydrolases secreted by Penicillium aculeatum and Fusarium pallidoroseum isolated from agricultural fields.
The present study aimed at a comparative characterization of two distinct extracellular monocrotophos hydrolases, from Penicillium aculeatum ITCC 7980.10 (M3) and Fusarium pallidoroseum ITCC 7785.10 (M4), isolated from agricultural fields. The MCP hydrolases were purified by Sephadex G-100 column and DEAE-Sepharose CL-6B ion-exchange column followed by SDS-PAGE analysis, which showed the presence of two hydrolases, of 33 and 67 kDa respectively. Both enzymes were most active at alkaline pH and were stable over a wide range of temperatures (60-70 °C). Between the strains, the MCP hydrolases from M3 were 2-fold more active than that from M4. Enzyme kinetic studies showed lowest Km (33.52 mM) and highest Vmax (5.18 U/mg protein) for OPH67 of M3 in comparison to the Km and Vmax of the other hydrolases purified from M3 and M4, suggesting that M3 OPH67 was the most efficient MCP hydrolase. To the best of our knowledge, this is the first report of the purification of two distinct extracellular thermostable MCP hydrolases from fungal strains Penicillium aculeatum ITCC 7980.10 and Fusarium pallidoroseum ITCC 7785.10. Owing to its potential MCP hydrolyzing activity, M3 OPH67 can perhaps used directly or in the encapsulated form for remediation of MCP contaminated sites.
Topics: Agriculture; Amides; Biodegradation, Environmental; Enzyme Stability; Extracellular Space; Fusarium; Hydrolases; Hydrolysis; Kinetics; Monocrotophos; Penicillium; Pesticides
PubMed: 23666511
DOI: 10.1271/bbb.120907 -
Indian Journal of Clinical Biochemistry... Jan 2012Oximes such as pralidoxime chloride reactivate acetylcholinesterase. However their role in management of organophosphate poisoning is controversial. The study was...
Oximes such as pralidoxime chloride reactivate acetylcholinesterase. However their role in management of organophosphate poisoning is controversial. The study was carried out to find effectiveness of pralidoxime chloride (2-PAM) in regenerating red cell acetyl cholinesterase in first 24 h following administration of it in dose recommended by WHO. Eight patients with OPP [chlorpyriphos (3), phorate (3), dichlorvos (1) and monocrotophos (1) who fulfilled the criteria for inclusion were investigated. In addition to decontamination and atropine, all these patients were administered 30 mg/kg body wt of 2-PAM as bolus dose followed by 7.5 mg/kg body wt/h with maximum dose being 500 mg/h as continuous infusion till first 24 h. Red cell AChE activity was estimated every 15 min for first 4 h, one hourly for next 4 h and then 2 hourly till 24 h and subsequently without 2-PAM every 12 h till 7 days or discharge or death which ever earlier. In all the patients maximum increase in activity was observed in first 4 h following which rise was very slow despite continued 2-PAM infusion and reaching a steady state in 20 h in all the cases. The increase in red cell AChE activity observed in diethyl group at 24 h of 2-PAM infusion was 154% vs. 81% in dimethyl group. At 7 days the increase in activity was 215% vs. 118% respectively. However on multiple repeated ANOVA, no statistically significant difference was observed between diethyl and dimethyl groups at admission and discharge (P > 0.05). Similarly no significant difference was observed in three groups when patients were categorized according to WHO classification of organophosphates (P > 0.05). The maximum increase in red cell AChE activity occurs in first 4 h of 2-PAM administration followed by a slow increase despite 2-PAM infusion till 24 h.
PubMed: 23277710
DOI: 10.1007/s12291-011-0152-0 -
Arhiv Za Higijenu Rada I Toksikologiju Sep 2012Several episodes of mass poisoning by organophosphates (OPs) have been reported from the developing countries. The diagnosis of OP-poisoning is mainly based on the...
Several episodes of mass poisoning by organophosphates (OPs) have been reported from the developing countries. The diagnosis of OP-poisoning is mainly based on the characteristic clinical features and history of exposure to a known OP compound. Estimation of serum and red blood cell (RBC) cholinesterase activities are helpful in confirming the diagnosis. However, there is controversy regarding a definite relationship between serum cholinesterase activity and the severity of clinical manifestations and prognosis. This report describes an episode of mass monocrotophos poisoning that occurred due to accidental ingestion of monocrotophos-contaminated millet (so-called bavta) flour involving eight severely poisoned persons. Clinical presentation included severe abdominal pain, diarrhoea, vomiting, pupil narrowing, and difficulty breathing. On hospital admission, plasma cholinesterase (PChE) and especially RBC acetylcholinesterase (AChE) activities correlated well with clinical symptoms presented by the patients. This case study highlights the need for clinicians to be aware of OP-pesticide poisoning from food sources and the need to look for depressed PChE and AChE activities that may point to OP exposure, so that OP-poisoning can be identified immediately and patients can receive specific treatment, rather than general treatment for food poisoning.
Topics: Adolescent; Adult; Child; Diarrhea; Dyspnea; Female; Flour; Food Contamination; Foodborne Diseases; Humans; India; Insecticides; Male; Middle Aged; Monocrotophos; Organophosphate Poisoning; Pain; Respiratory Insufficiency; Sialorrhea; Vomiting
PubMed: 23152387
DOI: 10.2478/10004-1254-63-2012-2158