Acetylcholinesterase Gene Research Articles

Expression of Drosophila melanogaster acetylcholinesterase (DmAChE) gene splice variants in Pichia pastoris and evaluation of its sensitivity to organophosphorus pesticides

Acetylcholinesterase (AChE) is a key enzyme used to detect organophosphorus pesticide residues by the enzyme inhibition method. An accidental discovery of a mutant strain with AChE activity was made in our laboratory during the process of AChE expression by Pichia pastoris. The pPIC9K-Drosophilamelanogaster acetylcholinesterase (DmAChE)-like expression vector was constructed by codon optimization of this mutant strain, which was transformed into P. pastoris GS115, and positive clones were selected on yeast peptone dextrose (YPD) plate with G418 at 4.0 mg/mL. The GS115-pPIC9K-DmAChE-like strain was subjected to 0.5% methanol induction expression for 120 h, with a protein band at 4.3 kDa found by the tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) pattern of the fermentation supernatant. After preliminary purification by ammonium sulfate precipitation, the enzyme activity was detected to be 76.9 U/(mL⋅min). In addition, the pesticide sensitivity test proved that DmAChE-like is selective and sensitive to organophosphorus pesticides.

Characterization and functional analysis of two acetylcholinesterase genes in Bradysia odoriphaga Yang et Zhang (Diptera: Sciaridae)

Two acetylcholinesterase genes (Boace1 and Boace2) were cloned from Bradysia odoriphaga, a devastating soil pest that mainly damages Chinese chives. The Boace1 encodes BoAChE1 protein consisting of 696 amino acid residues, while Boace2 encodes BoAChE2 containing 638 amino acids. Phylogenetic analysis showed that Boace1 and Boace2 are appeared to be distinct clusters. The gene expression patterns at different development stages and various body parts tissues were examined, and their biological functions were characterized by RNA interference and analog docking prediction. The results showed that both Boace genes were expressed in all developmental stages and examined tissues. The transcript level of Boace2 was significantly higher than Boace1 in all tested samples, and Boace1 was found most abundant in the head while Boace2 was highly expressed in the fat body of B. odoriphaga. The silencing of Boace1 and Boace2 significantly decreased the AChE activity of 36.6% and 14.8% separately, and increased the susceptibility of B. odoriphaga to phoxim, with 60.8% and 44.7% mortality. Besides, overexpression and gene duplication of Boace1 were found in two field resistant populations, and two major mutations, A319S and G400V, were detected in Boace1. Moreover, the docking results revealed that BoAChE1 had a higher affinity towards organophosphorus than BoAChE2. It is concluded that Boace2 is the most abundant ace type in B. odoriphaga, while both Boace play vital roles. Boace1 might play a major neurological function and more likely be the prime target for insecticides, while Boace2 might play some important unidentified roles.

Larvicidal activity of plant extracts by inhibition of detoxification enzymes in Culex pipiens

ObjectivesPlant extracts have been a safe and eco-friendly substituent of chemical pesticides, used against mosquitoes to prevent vector-borne infections e.g., chikungunya, yellow fever, dengue, filariasis, dirofilariasis tularemia, malaria, and many other diseases. MethodsThe larvicidal activities of the acetone extracts of four plants e.g., Lantana camara, Ruta chalepensis, Rhazya stricta, and Acalypha fruticosa was evaluated against Culex pipiens. The composition secondary metabolites of the most effective extract (L. camara) was examined using gas chromatography-mass spectrometry (GC–MS). The expression level of Acetylcholinesterase (AChE) and Glutathione S-transferase (GST) genes were assessed through qRT-PCR. ResultsThe results revealed that the extract of L. camara caused 98% mortality in Cx. pipiens followed by R. stricta (91%), A. fruticosa (79%), and R. chalepensis (69%) as compared to azadirachtin, used as a positive control. The results showed that LD50 and LD90 of the extract of L. camara were significantly higher as compared to R. stricta, A. fruticosa, and R. chalepensis extract. The extract of L. camara also significantly reduced the activities of AChE and GST as compared to the larvae, treated with the extracts of another plant extracts as well as a positive control. The chemical composition of L. camara, was determined through GC–MS. ConclusionsThe most important insecticidal compounds were including undecane, terephthalic acid, dimethyl-propane-thiosulfinate, fluorobenzoic acid octadecenoic acid. The insecticidal activity of the L. camara extracts against Cx. pipiens might be due to one or more of these compounds.

Defensive proclivity of bacoside A and bromelain against oxidative stress and AChE gene expression induced by dichlorvos in the brain of Mus musculus

The objective of current study was to evaluate the neuroprotective effects of bacoside A and bromelain against dichlorvos induced toxicity. The healthy, 6–8 weeks old male Swiss mice were administered in separate groups subacute doses of dichlorvos (40 mg/kg bw), bacoside A (5 mg/kg bw) and bromelain (70 mg/kg bw). In order to determination of oxidative stress in different groups, thiobarbituric acid reactive substances (TBARS) and protein carbonyl content (PCC) were studied in the present investigation. Moreover, for toxic manifestation at molecular level the site-specific gene amplification of acetylcholinesterase (AChE) gene was studied in the brain. Nonetheless, the protective effects of bacoside A and bromelain were also evaluated on the TBARS, PCC and AChE gene. The exposure of dichlorvos leads to significant increase in TBARS level (p < 0.01, p < 0.001) and PCC. Besides, the decline in DNA yield, expression of amplified products of AChE gene was observed in the brain of dichlorvos treated group. The bacoside A and bromelain treatments significantly decreased the level of TBARS (p < 0.05, (p < 0.01) and PCC whereas, increase in the DNA yield and expression of amplified AChE gene products were observed in the brain compared to only dichlorvos treated mice. The overall picture which emerged after critical evaluation of results indicated that the dichlorvos induced oxidative stress and alteration in AChE gene expression showed significant improvement owing to the treatments of bacoside A and bromelain. Thus, bacoside A and bromelain are very effective in alleviating neurotoxicity induced by dichlorvos.

Protein liposomes-mediated targeted acetylcholinesterase gene delivery for effective liver cancer therapy

BackgroundEffective methods to deliver therapeutic genes to solid tumors and improve their bioavailability are the main challenges of current medical research on gene therapy. The development of efficient non-viral gene vector with tumor-targeting has very important application value in the field of cancer therapy. Proteolipid integrated with tumor-targeting potential of functional protein and excellent gene delivery performance has shown potential for targeted gene therapy.ResultsHerein, we prepared transferrin-modified liposomes (Tf-PL) for the targeted delivery of acetylcholinesterase (AChE) therapeutic gene to liver cancer. We found that the derived Tf-PL/AChE liposomes exhibited much higher transfection efficiency than the commercial product Lipo 2000 and shown premium targeting efficacy to liver cancer SMMC-7721 cells in vitro. In vivo, the Tf-PL/AChE could effectively target liver cancer, and significantly inhibit the growth of liver cancer xenografts grafted in nude mice by subcutaneous administration.ConclusionsThis study proposed a transferrin-modified proteolipid-mediated gene delivery strategy for targeted liver cancer treatment, which has a promising potential for precise personalized cancer therapy.

Resistance to pirimiphos-methyl in West African Anopheles is spreading via duplication and introgression of the Ace1 locus.

Vector population control using insecticides is a key element of current strategies to prevent malaria transmission in Africa. The introduction of effective insecticides, such as the organophosphate pirimiphos-methyl, is essential to overcome the recurrent emergence of resistance driven by the highly diverse Anopheles genomes. Here, we use a population genomic approach to investigate the basis of pirimiphos-methyl resistance in the major malaria vectors Anopheles gambiae and A. coluzzii. A combination of copy number variation and a single non-synonymous substitution in the acetylcholinesterase gene, Ace1, provides the key resistance diagnostic in an A. coluzzii population from Côte d’Ivoire that we used for sequence-based association mapping, with replication in other West African populations. The Ace1 substitution and duplications occur on a unique resistance haplotype that evolved in A. gambiae and introgressed into A. coluzzii, and is now common in West Africa primarily due to selection imposed by other organophosphate or carbamate insecticides. Our findings highlight the predictive value of this complex resistance haplotype for phenotypic resistance and clarify its evolutionary history, providing tools to for molecular surveillance of the current and future effectiveness of pirimiphos-methyl based interventions.

Widespread multiple insecticide resistance in the major dengue vector Aedes albopictus in Hainan Province, China

BACKGROUND Aedes albopictus is a highly invasive mosquito and has become a potential vector of dengue, chikungunya and Zika viruses. Insecticide‐based mosquito interventions are the main tools for vector‐borne disease control. However, mosquito resistance to insecticides is a major threat to effective prevention and control. Five Ae. albopictus populations across Hainan Province, China were investigated for susceptibility to multiple insecticide and resistance mechanisms.RESULTSLarval bioassays indicated that resistance to pyrethroids was common in all larval populations. Adult bioassays revealed all populations were either resistant or highly resistant to at least four of the six synthetic insecticides (deltamethrin, permethrin, cyfluthrin, propoxur, malathion, and DDT) tested. Pre‐exposure of mosquitoes to the synergistic agent piperonyl butoxide (PBO) increased mosquito mortality by 2.4–43.3% in bioassays to DDT, malathion, and permethrin and rendered mosquito sensitive to deltamethrin, cyfluthrin, and propoxur. The frequency of knockdown resistance (kdr) mutations (F1534S and F1534C) ranged from 69.8% to 89.3% and from 38.1% to 87.0% in field‐resistant and sensitive populations, respectively. F1534S mutation was significantly associated with pyrethroid resistance. No mutation was detected in the acetylcholinesterase (ace‐1) gene in the two examined populations.CONCLUSIONThis study provides evidence of widespread resistance to multiple insecticides in Ae. albopictus in Hainan Province, China. Both kdr mutations and metabolic detoxification were potential causes of insecticide resistance for Ae. albopictus. Our findings highlight the need for insecticide resistance management and mosquito control measures that do not entirely depend on synthetic insecticides. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

CRISPR/Cas9-mediated genome editing of Schistosoma mansoni acetylcholinesterase.

CRISPR/Cas9-mediated genome editing shows cogent potential for the genetic modification of helminth parasites. We report successful gene knock-in (KI) into the genome of the egg of Schistosoma mansoni by combining CRISPR/Cas9 with single-stranded oligodeoxynucleotides (ssODNs). We edited the acetylcholinesterase (AChE) gene of S. mansoni targeting two guide RNAs (gRNAs), X5 and X7, located on exon 5 and exon 7 of Smp_154600, respectively. Eggs recovered from livers of experimentally infected mice were transfected by electroporation with a CRISPR/Cas9-vector encoding gRNA X5 or X7 combining with/ without a ssODN donor. Next generation sequencing analysis of reads of amplicon libraries spanning targeted regions revealed that the major modifications induced by CRISPR/Cas9 in the eggs were generated by homology directed repair (HDR). Furthermore, soluble egg antigen from AChE-edited eggs exhibited markedly reduced AChE activity, indicative that programed Cas9 cleavage mutated the AChE gene. Following injection of AChE-edited schistosome eggs into the tail veins of mice, an significantly enhanced Th2 response involving IL-4, -5, -10, and-13 was detected in lung cells and splenocytes in mice injected with X5-KI eggs in comparison to control mice injected with unmutated eggs. A Th2-predominant response, with increased levels of IL-4, -13, and GATA3, also was induced by X5 KI eggs in small intestine-draining mesenteric lymph node cells when the gene-edited eggs were introduced into the subserosa of the ileum of the mice. These findings confirmed the potential and the utility of CRISPR/Cas9-mediated genome editing for functional genomics in schistosomes.

An overview of the mitigating mechanisms of the fitness cost of mutations associated with pesticide resistance in arthropods

Alleles that cause resistance to pesticides may also result in host physiological cost, as they can impair phenotypes such as reproduction and survival. However, works have described that in some arthropods mechanisms that mitigate the physiological cost have also been selected. This review covers a survey of the fitness attenuating mechanisms reported in the literature that can contribute to the maintenance of resistance in arthropods. Searches were made in the Pubmed and Scopus databases, from October 2019 to January 2020, to find references related to the topic, using combinations of key words, the Boolean operator AND, as well as inclusion and exclusion criteria. Sixty-one scientific articles were obtained, which were selected from the title and abstract. Different attenuation mechanisms were found and were classified into nine categories according to the mechanism of action described in the article. The Diptera Order was the most addressed in the articles (24 articles), represented mainly by the Culicidae family mosquitoes (17 articles). Gene duplication, mainly of acetylcholinesterase genes, was the mechanism most found (14 articles), and the one with the greatest variety of species in which it occurs (eight species from three Orders, including insects and arachnids).

A study on lethal doses of various pesticides on honeybees (Apis mellifera L.) – a laboratory trial

AbstractExposure of honeybee (Apis mellifera L.) to pesticides disturbed normal physiological and behavioral functions required for normal foraging and colony maintenance. The present study was aimed towards establishing the mean lethal concentration (LC50) of three pesticides viz. carbamate (carbaryl), organophosphate (chlorpyrifos) and neonicotinoid (imidacloprid) in honeybees through feeding bioassay laboratory trial. Deleteriousness was confirmed through mortality rate, number of survival bees, acetylcholinesterase (AChE), total protein (TP) levels, AChE gene transcription level, and gut tissues histological analysis of exposed honeybees. Mean mortality rate was calculated for 96 h interval at three different concentrations of tested pesticides (5, 2.5, and 1.25 mg L−1), and LC50 values calculated for 48 and 96 h interval. AChE enzyme and TP level are determined by ELIZA and spectrophotometer, respectively. Results revealed that imidacloprid had the lowest LC50 (0.477 ng/bee) values as compared with carbaryl and chlorpyrifos. High mortality rate was observed at highest dose, being impidacloprid have more lethal effects as compared with other pesticides. Similarly, biochemical analysis revealed that imidiacloprid and chlorpyrifos significantly (P ≤ 0.05) increased AChE and TP levels, whereas carbaryl significantly (P ≤ 0.05) decreased them. Similarly, probe based RT qPCR revealed that imidacloprid and chlorpyrifos treatments significantly (P ≤ 0.05) enhanced the AChE level whereas carbaryl decreased it. Histological analysis showed that the gut tissues of honeybees exposed to pesticide treatment had substantial morphological abnormalities. In a nutshell, imidacloprid, carbaryl and chlorpyrifos have substantial toxic effects on all the study attributes of honeybees with imidacloprid being most toxic.

Characterization of the rat Acetylcholinesterase readthrough (AChE-R) splice variant: Implications for toxicological studies

Exposure to chemicals and other environmental stressors can differentially impact the expression of Acetylcholinesterase (AChE) splice variants. Surprisingly, despite the widespread use of the rat model in toxicological studies and the wealth of literature on this important biomarker of neurotoxicity, AChE coding exons and splice variants are not yet fully annotated in this species. To address this knowledge gap, a short problematic region of the rat AChE genomic DNA present in GenBank was first re-sequenced. This revised genomic sequence was then aligned to rat AChE RefSeq mRNA and compared to orthologous mammalian sequences, in order to map the coding exon and intron boundaries of the rat AChE gene. Based on these bioinformatics analyses, a sequence was predicted for the yet-unannotated rat Acetylcholinesterase readthrough (AChE-R) splice variant. PCR primers designed to specifically amplify rat AChE-R were used to confirm its expression in rat PC12 cells. Compared to the canonical AChE-S splice variant, AChE-R was expressed at much lower levels but presented distinct regulation patterns in PC12 cells and rat primary cerebral granule cells (CGCs) following exposure to Chlorpyrifos (a well-known neurotoxic organophosphate pesticide). Taken together, these observations point to the evolutionary conservation of the AChE-R splicing event between rodents and human and to the distinct regulation of AChE splice variants in response to toxicological challenges.

Oxidative Stress and Analysis of Selected SNPs of ACHE (rs 2571598), BCHE (rs 3495), CAT (rs 7943316), SIRT1 (rs 10823108), GSTP1 (rs 1695), and Gene GSTM1, GSTT1 in Chronic Organophosphates Exposed Groups from Cameroon and Pakistan.

The detrimental effects of organophosphates (OPs) on human health are thought to be of systemic, i.e., irreversible inhibition of acetylcholinesterase (AChE) at nerve synapses. However, several studies have shown that AChE inhibition alone cannot explain all the toxicological manifestations in prolonged exposure to OPs. The present study aimed to assess the status of antioxidants malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) (reduced), catalase, and ferric reducing antioxidant power (FRAP) in chronic OP-exposed groups from Cameroon and Pakistan. Molecular analysis of genetic polymorphisms (SNPs) of glutathione transferases (GSTM1, GSTP1, GSTT1), catalase gene (CAT, rs7943316), sirtuin 1 gene (SIRT1, rs10823108), acetylcholinesterase gene (ACHE, rs2571598), and butyrylcholinesterase gene (BCHE, rs3495) were screened in the OP-exposed individuals to find the possible causative association with oxidative stress and toxicity. Cholinesterase and antioxidant activities were measured by colorimetric methods using a spectrophotometer. Salting-out method was employed for DNA extraction from blood followed by restriction fragment length polymorphism (RFLP) for molecular analysis. Cholinergic enzymes were significantly decreased in OP-exposed groups. Catalase and SOD were decreased and MDA and FRAP were increased in OP-exposed groups compared to unexposed groups in both groups. GSH was decreased only in Pakistani OPs-exposed group. Molecular analysis of ACHE, BCHE, Catalase, GSTP1, and GSTM1 SNPs revealed a tentative association with their phenotypic expression that is level of antioxidant and cholinergic enzymes. The study concludes that chronic OPs exposure induces oxidative stress which is associated with the related SNP polymorphism. The toxicogenetics of understudied SNPs were examined for the first time to our understanding. The findings may lead to a newer area of investigation on OPs induced health issues and toxicogenetics.

The production of a synthetic chemodisruptive peptide in planta precludes Meloidogyne incognita multiplication in Solanum melongena

Root-knot nematodes (RKNs) impose a severe constraint on eggplant productivity and sustainable options to minimize nematode populations below the economic threshold level are limited. In the present study, transgenic eggplants expressing a synthetic peptide (under the control of CaMV35S promoter) that disrupts nematode chemoreception were used as a proof-of-concept to assess the potential of hitherto-underexploited peptide-based transgenics in conferring nematode resistance. Six transgenic eggplant lines were characterized which were genotyped via PCR, qRT-PCR and Southern hybridization analyses. When challenge inoculated with RKN, all the peptide-expressing lines exhibited detrimental effect on nematode host location and penetration of host root. Consequently, perturbed infection ability and parasitic success of RKN on transgenic root was documented with 64.39–79.65% reduction in nematode multiplication. Root exudates of transgenic eggplant strongly elevated the expression of acetylcholinesterase genes (Mi-ace-1 and Mi-ace-2) in RKN. This altered expression of Mi-ace-1 and Mi-ace-2 was correlated with the efficacy of exudates as presoak solution for nematodes that affected their attraction to wild-type eggplant roots. The current study reestablishes the efficacy of novel, biosafe chemoreception-disruptive peptides in suppressing the nematode parasitism when expressed in planta. Gene pyramiding-based transgenic deployment of this peptide with proteinase inhibitor such as cystatin can satisfactorily increase the global agricultural output.

&lt;p&gt;&lt;strong&gt;&lt;span&gt;Transcriptome analys&lt;/span&gt;&lt;/strong&gt;&lt;strong&gt;&lt;span&gt;i&lt;/span&gt;&lt;/strong&gt;&lt;strong&gt;&lt;span&gt;s of &lt;/span&gt;&lt;/strong&gt;&lt;strong&gt;&lt;em&gt;&lt;span&gt;Tetranychus cinnabarinus&lt;/span&gt;&lt;/em&gt;&lt;/strong&gt;&lt;strong&gt;&lt;span&gt; responses to an insecticide exposure&lt;/span&gt;&lt;/strong&gt;&lt;/p&gt;

Diflubenzuron, a benzoylphenylurea insecticide that interferes with chitin biosynthesis, causes arthropods to moult abnormally and die. However, its mechanism of action in Tetranychus cinnabarinus is still unclear. In order to explore the effects of different sublethal concentrations of diflubenzuron on T. cinnabarinus, we conducted a high-throughput RNA-seq technology to identify the variations in transcriptomic profile of T. cinnabarinus larvae. The results revealed that 470 and 49 differentially expressed genes were identified in LC50-and LC70-treated groups, comparing with the control. We also identified and analyzed the detoxification enzymes involved in the transcritome of T. cinnabarinus, including 34 cytochrome P450 genes, 17 glutathione-s-transferase genes (GSTs), 12 acetylcholinesterase genes (AChEs) and 9 ABC transporter genes. In addition, differentially expressed genes analysis showed that the gene expression levels of detoxification enzymes were generally enhanced. At the same time, seven and eleven genes were involved in chitin synthesis and degradation ways, respectively. The expression level of most genes involved in chitin synthesis and degradation pathway were generally up-regulated after exposure to sublethal concentrations of diflubenzuron. Moreover, for transcriptome validation, the mRNA expression results of ten specially expressed genes by quantitative real-time PCR demonstrated that these gene expression trends were consistent with that of the transcriptome data. Together, all these results suggested that sublethal concentrations of diflubenzuron exposure affected gene expression of major detoxification enzymes and chitin metabolism genes in T. cinnabarinus larvae. These findings may be helpful to further understand the possible molecular mechanism of benzoylphenylurea insecticides in T. cinnabarinus, as well as in other spider mites.

Susceptibility of fall armyworm, Spodoptera frugiperda (J.E. Smith), to eight insecticides in China, with special reference to lambda-cyhalothrin

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is the main destructive insect pest of grain crops that occurs in all maize growing regions of the Americas. It has rapidly invaded the Southern China since January 2019. However, the current status of insecticide resistance in S. frugiperda has not been reported in China. In this study, we determined the susceptibility of eight populations of FAW to eight insecticides by an artificial diet incorporation method. The results showed that among eight insecticides, emamectin benzoate, spinetoram, chlorantraniliprole, chlorfenapyr, and lufenuron showed higher toxicity to this pest, while lambda-cyhalothrin and azadirachtin exhibited lower toxicity. Susceptibility of S. frugiperda to indoxacarb was significantly different (10.0-fold for LC50) across the various geographic populations. To investigate the biochemical mechanism of FAW to lambda-cyhalothrin, we performed the synergism tests and the results showed that piperonyl butoxide (PBO) and triphenyl phosphate (TPP) produced a high synergism of lambda-cyhalothrin effects in the two field populations. Sequencing of the gene encoding the acetylcholinesterase (AChE) gene in the two field populations identified two amino acid mutations, all of which have been shown previously to confer resistance to organophosphates (OPs) in several arthropod species. The results of this study provided valuable information for choosing alternative insecticides and for insecticide resistance management of S. frugiperda.

Insecticide resistance in Anopheles stephensi in Somali Region, eastern Ethiopia

BackgroundThe movement of malaria vectors into new areas is a growing concern in the efforts to control malaria. The recent report of Anopheles stephensi in eastern Ethiopia has raised the necessity to understand the insecticide resistance status of the vector in the region to better inform vector-based interventions. The aim of this study was to evaluate insecticide resistance in An. stephensi in eastern Ethiopia using two approaches: (1) World Health Organization (WHO) bioassay tests in An. stephensi; and (2) genetic analysis of insecticide resistance genes in An. stephensi in eastern Ethiopia.MethodsMosquito larvae and pupae were collected from Kebri Dehar. Insecticide susceptibility of An. stephensi was tested with malathion 5%, bendiocarb 0.1%, propoxur 0.1%, deltamethrin 0.05%, permethrin 0.75%, pirimiphos-methyl 0.25% and DDT 4%, according to WHO standard protocols. In this study, the knockdown resistance locus (kdr) in the voltage gated sodium channel (vgsc) and ace1R locus in the acetylcholinesterase gene (ace-1) were analysed in An. stephensi.ResultsAll An. stephensi samples were resistant to carbamates, with mortality rates of 23% and 21% for bendiocarb and propoxur, respectively. Adult An. stephensi was also resistant to pyrethroid insecticides with mortality rates 67% for deltamethrin and 53% for permethrin. Resistance to DDT and malathion was detected in An. stephensi with mortality rates of 32% as well as An. stephensi was resistance to pirimiphos-methyl with mortality rates 14%. Analysis of the insecticide resistance loci revealed the absence of kdr L1014F and L1014S mutations and the ace1R G119S mutation.ConclusionOverall, these findings support that An. stephensi is resistant to several classes of insecticides, most notably pyrethroids. However, the absence of the kdr L1014 gene may suggest non-target site resistance mechanisms. Continuous insecticide resistance monitoring should be carried out in the region to confirm the documented resistance and exploring mechanisms conferring resistance in An. stephensi in Ethiopia.

Correlation of plasma butyrylcholinesterase concentration with Acethylcholinesterase H353N polymorphism in the inflammatory response of Chagas disease patients

Trypanosoma cruzi infection triggers an intense production of pro-inflammatory cytokines mediated by T helper 1 lymphocytes, inducing the anti-inflammatory reflex of acetylcholine (ACh). The ACh concentration modulation is associated to the two major esterases, the acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). AChE H353N protein polymorphism is related to low Chagas chronic disease prognostic. In order to evaluate the correlation of plasmatic BuChE concentration and the presence of AChE H353N polymorphism in Chagas disease patients and healthy individuals, we studied two groups of individuals, one of 61 Chagas disease patients and another of 74 healthy individuals. Plasma concentration of BuChE was measured by the chemiluminescent method and AChE H353N polymorphism was investigated by PCR-RFLP and sequencing of the respective encoding AChE gene fragment. The BuChE concentration was statistically higher in Chagas disease patients, with no AChE genotype significant influence. AChE genotypes YT*A/YT*A, YT*A/YT*B and YT*B/YT*B, respectively, were expressed in 53 (86.88%), 7 (11.46%) and one (1.64%) chagasic patients, and in 68 (91.89%), 6 (8.10%) and none healthy individuals. BuChE activity may represent an important marker for chronic Chagas disease inflammatory process and prognostic. Lower BuChE concentration correlated with AChE YT*B allele, although without statistical power.

Vitamin D dietary supplementation ameliorates the complications associated with type 2 diabetes induced by streptozotocin

Type 2 diabetes is a major public health problem, accounting for significant premature mortality and morbidity. It has been reported to be associated with several chronic complications which involve coronary artery disease and renal and liver diseases that are considered the primary cause of disability and mortality in diabetic patients. Different studies stated that vitamin D have functional role in glucose tolerance through its effects on insulin secretion and sensitivity and ameliorate type 2 diabetes complication. For that this study was carried out to investigate the effect of dietary vitamin D on type 2 diabetes complication on the liver, pancreas, lipid profile, and brain function. Rats were divided into 5 groups (control, diabetic, Vitamin D treated, Vitamin D preventive, and vitamin D control). Blood and tissue samples were collected after 6 weeks for measurement of fasting blood glucose (FBG), HOMA-IR, fasting serum insulin (FSI), serum lipid profile, blood antioxidants [reduced glutathione (GSH),superoxide dismutase (SOD), and catalase], serum lipid peroxidation product (malondialdehyde (MDA)), and histopathological examination of the pancreas and liver, besides brain acetylcholinesterase (AChE) gene expression. Our results indicated that dietary vitamin D supplementation to diabetic rats significantly increased FSI, decreased FBG and HOMA-IR, enhancing lipid profile by increase HDL-C and decrease LDL-C, TAG, and VLDL-C; Vitamin D also ameliorate GSH level and catalase activity and decrease the level of serum MDA, in addition to depress expression of brain AChE gene and improving liver and pancreas architecture. From these results, it can be concluded that vitamin D assured great protection against type 2 diabetes complications in rats.

Single or combined exposure to chlorpyrifos and cypermethrin provoke oxidative stress and downregulation in monoamine oxidase and acetylcholinesterase gene expression of the rat's brain.

The extensive uses of organophosphates and pyrethroids have made it necessary to investigate the neurotoxicity of their combination as they may implicate in the neurodegenerative syndromes. Monoamine oxidase-A (MAO-A) and acetylcholinesterase (AChE) gene expression in the rat brain were evaluated after independent and combined intoxications with chlorpyrifos and cypermethrin. Twenty-four mature male rats were equally distributed into four groups. The first one was kept as a control group, whereas the second, third and fourth were orally gavage with chlorpyrifos (16.324mg/kg), cypermethrin (25.089mg/kg) and their combination (9.254mg/kg), respectively, for 4weeks. As compared to the control group, intoxications with chlorpyrifos and/or cypermethrin revealed significant (P < 0.05) declines in the levels of brain neurotransmitters (dopamine and serotonin) plus the enzymatic activities of MAO-A, AChE and sodium-potassium adenosine triphosphatase. The mRNA genes expression of MAO-A and AChE have also confirmed the enzymatic actions. Moreover, the oxidative injury recorded as the levels of malondialdehyde and nitric oxide markedly increased (P < 0.01), while the total thiol content reduced and the histopathological outcomes have confirmed these impacts. In conclusion, chlorpyrifos and cypermethrin revealed antagonistic inhibitions on the brain MAO-A and AChE gene regulation through neurotransmission deteriorations and oxidative damage, which could describe their contributions in the neuropathological progressions.

Genomics of Acetylcholinesterase gene expression and related RNA content in brain of five different vertebrate species: A prospective institutional study

Genomics of Acetylcholinesterase gene expression and related RNA content in brain of five different vertebrate species: A prospective institutional study