Associations of A20, CYLD, Cezanne and JAK2 Genes and Immunophenotype with Psoriasis Susceptibility.

Background and Objectives: Psoriasis is an immune-mediated chronic inflammatory skin disorder and commonly associated with highly noticeable erythematous, thickened and scaly plaques. Deubiquitinase genes, such as tumor necrosis factor-alpha protein 3 (TNFAIP3, A20), the cylindromatosis (CYLD) and Cezanne, function as negative regulators of inflammatory response through the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. In this study, polymorphisms and expressions of A20, CYLD and Cezanne genes as well as immunophenotype in psoriatic patients were determined. Materials and Methods: In total, 82 patients with psoriasis and 147 healthy individuals with well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by direct DNA sequencing, gene expression profile by quantitative real time-polymerase chain reaction (PCR), immunophenotype by flow cytometry, and the secretion of cytokines and cancer antigen (CA) 125 by enzyme-linked Immunosorbent assay (ELISA). Results: The inactivation of A20, CYLD and Cezanne and increased levels of TNF-α, IFN-γ and CA 125 was observed in psoriatic patients. Importantly, patients with low A20 expression had significant elevations of triglyceride and total cholesterol concentrations and higher numbers of CD13+CD117- and CD19+CD23+ (activated B) cells than those with high A20 expression. Genetic analysis indicated that all rs4495487 SNPs in the JAK2 gene, rs200878487 SNPs in the A20 gene and four SNPs (c.1584-375, c.1584-374, rs1230581026 and p.W433R) in the Cezanne gene were associated with significant risks, while the rs10974947 variant in the JAK2 gene was at reduced risk of psoriasis. Moreover, in the Cezanne gene, p.W433R was predicted to be probably damaging by the Polyphen-2 prediction tool and an AA/CC haplotype was associated with a high risk of psoriasis. In addition, patients with higher CA 125 levels than the clinical cutoff 35 U/mL showed increased levels of IFN-γ than those with normal CA 125 levels. Conclusions: A20 expression was associated with lipid metabolism and the recruitment of CD13+ CD117- and activated B cells into circulation in psoriatic patients. Besides this, the deleterious effect of the p.W433R variant in the Cezanne gene may contribute to the risk of psoriasis.

Association of PSORS1C3, CARD14 and TLR4 genotypes and haplotypes with psoriasis susceptibility.

Psoriasis is a common chronic, immune-mediated inflammatory disease of the skin. PSORS1C3 is a non-protein coding gene, of which the RNA transcript is found in psoriatic patients. CARD14 is mainly expressed in epidermal keratinocytes. TLR4 is a transmembrane protein to recognize microbial antigens. Our study aimed to assess the relationship among PSORS1C3, CARD14 and TLR4 polymorphisms, inflammatory expression and psoriasis susceptibility. To the end, 71 patients with psoriasis and 46 healthy individuals with the well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by Sanger DNA sequencing and secretion of cytokines by ELISA. As a result, genetic analysis of PSORS1C3 gene identified nine SNPs and three haplotype blocks. Sequencing of the CARD14 gene determined eight SNPs and one haplotype block. Sequencing of TLR4 gene identified nine SNPs, in which a SNP rs1018673641 was found to exert deleterious effect. The linkage disequilibrium analysis showed that seven variants in PSORS1C3 gene and three SNPs in CARD14 gene were in tightly linked. More importantly, a significant association between IL-6 level and rs1018673641 AT genotype in TLR4 gene was detected in psoriatic patients. In conclusion, the PSORS1C3, CARD14 and TLR4 polymorphisms and haplotypes may be correlated with risk of suffering psoriasis and the IL-6-mediated chronic inflammation in psoriasis could be partially regulated by the TLR4 functional variant.

Investigation of the gut microbiome of Apis cerana honeybees from Vietnam.

OBJECTIVES: In this study, the gut microbiome of healthy adult honeybees, Apis cerana, was investigated by sequencing the V3 - V4 region in 16S rRNA gene using Illumina Miseq platform. RESULTS: The total of 37,853 reads for 16S rRNA gene were obtained and 30,121 (79.6%) reads were valid with 25,291 (84.0%) reads that were classified into 116 species belonging to four major phyla. The relative abundances of the bacterial isolates in honeybee samples were phylum Proteobacteria (70.7%), Actinobacteria (10.7%), Firmicutes (10.3%), and Bacteroidetes (8.4%), respectively. Lactic acid bacteria comprised 18.95% with 10 groups including Bifidobacterium asteroides, B. indicum, Fructobacillus fructosus, Lactobacillus apinorum, L. apis, L. helsingborgensis, L. kimbladii, L. kullabergensis, and L. kunkeei. CONCLUSIONS: The presence of beneficial bacteria in the gut highlighted their role in the honeybee and suggested that they can be promising candidates for the development of probiotics for health improvement, infection control and disease management of honeybees.

Three novel mutations in the ATP7B gene of unrelated Vietnamese patients with Wilson disease.

BACKGROUND: Wilson disease (OMIM # 277900) is a autosomal recessive disorder characterized by accumulation of copper in liver and brain. The accumulation of copper resulting in oxidative stress and eventually cell death. The disease has an onset in a childhood and result in a significant neurological impairment or require lifelong treatment. Another serious consequence of the disease is the development of liver damage and acute liver failure leading to liver transplant. The disorder is caused by mutations in the ATP7B gene, encoding a P-type copper transporting ATPase. CASE PRESENTATION: We performed genetic analysis of three unrelated patients from three different Vietnamese families. These patients had clinical features such as numbness of hands and feet, vomiting, insomnia, palsy, liver failure and Kayser-Fleischer (K-F) rings and were diagnosed with Wilson disease in the Human Genetics Department, Vietnam National Children's Hospital. The entire coding region and adjacent splice sites of ATP7B gene were amplified and sequenced by Sanger method. Sequencing data were analyzed and compared with the ATP7B gene sequence published in Ensembl (ENSG00000123191) by using BioEdit software to detect mutations. CONCLUSIONS: In this study, five mutations in the ATP7B gene were found. Among of these, three mutations were novel: c.750_751insG (p.His251Alafs*19) in exon 2, c.2604delC (p.Pro868Profs*5) in exon 11, and c.3077 T > A (p.Phe1026Tyr) in exon 14. Our results of the mutations associated with Wilson disease might facilitate the development of effective treatment plans.

Comparative Genomic Analysis for Genetic Variation in Sacbrood Virus of Apis cerana and Apis mellifera Honeybees From Different Regions of Vietnam.

Sacbrood virus (SBV) is one of the most common viral infections of honeybees. The entire genome sequence for nine SBV infecting honeybees, Apis cerana and Apis mellifera, in Vietnam, namely AcSBV-Viet1, AcSBV-Viet2, AcSBV-Viet3, AmSBV-Viet4, AcSBV-Viet5, AmSBV-Viet6, AcSBV-Viet7, AcSBV-Viet8, and AcSBV-Viet9, was determined. These sequences were aligned with seven previously reported complete genome sequences of SBV from other countries, and various genomic regions were compared. The Vietnamese SBVs (VN-SBVs) shared 91-99% identity with each other, and shared 89-94% identity with strains from other countries. The open reading frames (ORFs) of the VN-SBV genomes differed greatly from those of SBVs from other countries, especially in their VP1 sequences. The AmSBV-Viet6 and AcSBV-Viet9 genome encodes 17 more amino acids within this region than the other VN-SBVs. In a phylogenetic analysis, the strains AmSBV-Viet4, AcSBV-Viet2, and AcSBV-Viet3 were clustered in group with AmSBV-UK, AmSBV-Kor21, and AmSBV-Kor19 strains. Whereas, the strains AmSBV-Viet6 and AcSBV-Viet7 clustered separately with the AcSBV strains from Korea and AcSBV-VietSBM2. And the strains AcSBV-Viet8, AcSBV-Viet1, AcSBV-Viet5, and AcSBV-Viet9 clustered with the AcSBV-India, AcSBV-Kor and AcSBV-VietSBM2. In a Simplot graph, the VN-SBVs diverged stronger in their ORF regions than in their 5' or 3' untranslated regions. The VN-SBVs possess genetic characteristics which are more similar to the Asian AcSBV strains than to AmSBV-UK strain. Taken together, our data indicate that host specificity, geographic distance, and viral cross-infections between different bee species may explain the genetic diversity among the VN-SBVs in A. cerana and A. mellifera and other SBV strains.

Genome Characteristics of the Endophytic Fungus Talaromyces sp. DC2 Isolated from Catharanthus roseus (L.) G. Don.

Talaromyces sp. DC2 is an endophytic fungus that was isolated from the stem of Catharanthus roseus (L.) G. Don in Hanoi, Vietnam and is capable of producing vinca alkaloids. This study utilizes the PacBio Sequel technology to completely sequence the whole genome of Talaromyces sp. DC2The genome study revealed that DC2 contains a total of 34.58 Mb spanned by 156 contigs, with a GC content of 46.5%. The identification and prediction of functional protein-coding genes, tRNA, and rRNA were comprehensively predicted and highly annotated using various BLAST databases, including non-redundant (Nr) protein sequence, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Carbohydrate-Active Enzymes (CAZy) databases. The genome of DC2 has a total of 149, 227, 65, 153, 53, and 6 genes responsible for cellulose, hemicellulose, lignin, pectin, chitin, starch, and inulin degradation, respectively. The Antibiotics and Secondary Metabolites Analysis Shell (AntiSMASH) analyses revealed that strain DC2 possesses 20 biosynthetic gene clusters responsible for producing secondary metabolites. The strain DC2 has also been found to harbor the DDC gene encoding aromatic L-amino acid decarboxylase enzyme. Conclusively, this study has provided a comprehensive understanding of the processes involved in secondary metabolites and the ability of the Talaromyces sp. DC2 strain to degrade plant cell walls.

Two novel CD40LG gene mutations causing X-linked hyper IgM syndrome in Vietnamese patients.

The X-linked hyper IgM syndrome is a primary immunodeficiency disorder (PID) due to mutations in the CD40LG gene. Hyper IgM syndrome is characterized by the absence or decreased levels of IgG and IgA and normal or elevated IgM levels in serum. Affected patients become susceptible to infections such as pneumonia, diarrhea, and skin ulcer types. Hematopoietic stem cell transplantation is the only treatment currently available and ideally performed before the age of 10 years. Early, accurate diagnosis will contribute to the effective treatment for patients with hyper IgM. The patients from different Vietnamese families who have been diagnosed with hyper IgM at The Allergy, Immunology and Rheumatology Department, Vietnam National Hospital Pediatrics, were performed a genetic analysis using whole exome sequencing. The mutations were confirmed by the Sanger sequencing method in patients and their families. The influence of the mutations was predicted with the in silico analysis tools: PROVEAN, SIFT, PolyPhen-2, and MutationTaster. In this study, two novel mutations (p.Thr254fs and p.Leu138Phe) in the CD40LG gene were found in Vietnamese patients with X-linked hyper IgM syndrome. Our results contribute to the general understanding of the etiology of the disease and can help diagnose the different forms of PID.

Case Report: Novel rare mutation c.6353C > G in the ABCA12 gene causing harlequin ichthyosis identified by whole exome sequencing.

Background: Harlequin ichthyosis (HI) is a severe rare genetic disease that mainly affects the skin. Neonates with this disease are born with thick skin and large diamond-shaped plates covering most of their bodies. Affected neonates lose the ability to control dehydration and regulate temperature and are more susceptible to infections. They also face respiratory failure and feeding problems. These clinical symptoms are factors associated with high mortality rates of neonates with HI. Until now, there are still no effective treatments for HI patients and most patients die in the newborn period. Mutation in the ABCA12 gene, which encodes an adenosine triphosphate-binding cassette (ABC) transporter, has been demonstrated as the major cause of HI. Case presentation: In this study, we report the case who is one infant that was born prematurely at 32 gestational weeks with the whole body covered with thick plate-like scales of skin. The infant was severely infected with mild edema, multiple cracked skins full of the body, yellow discharge, and necrosis of fingers and toes. The infant was suspected to be affected by HI. Whole exome sequencing (WES) was performed as a tool for detecting the novel mutation in one prematurely born Vietnam infant with HI phenotype. And after that, the mutation was confirmed by the Sanger sequencing method in the patient and the members of his family. In this case, one novel mutation c.6353C > G (p.S2118X, Hom) in the ABCA12 gene, was detected in the patient. The mutation has not been reported in any HI patients previously. This mutation was also found in a heterozygous state in the members of the patient's family, including his parents, an older brother, and an older sister who are no symptoms. Conclusions: In this study, we identified a novel mutation in a Vietnamese patient with HI by whole exome sequencing. The results for the patient and the members of his family will be helpful in understanding the etiology of the disease, diagnosing carriers, assisting in genetic counseling, and emphasizing the need for DNA-based prenatal screening for families with a history of the disease.

Novel mutations in the SGCA gene in unrelated Vietnamese patients with limb-girdle muscular dystrophies disease.

Background: Limb-girdle muscular dystrophy (LGMD) is a group of inherited neuromuscular disorders characterized by atrophy and weakness in the shoulders and hips. Over 30 subtypes have been described in five dominant (LGMD type 1 or LGMDD) and 27 recessive (LGMD type 2 or LGMDR). Each subtype involves a mutation in a single gene and has high heterogeneity in age of onset, expression, progression, and prognosis. In addition, the lack of understanding of the disease and the vague, nonspecific symptoms of LGMD subtypes make diagnosis difficult. Even as next-generation sequencing (NGS) genetic testing has become commonplace, some patients remain undiagnosed for many years. Methods: To identify LGMD-associated mutations, Targeted sequencing was performed in the patients and Sanger sequencing was performed in patients and family members. The in silico analysis tools such as Fathmm, M-CAP, Mutation Taster, PolyPhen 2, PROVEAN, REVEL, SIFT, MaxEntScan, Spliceailookup, Human Splicing Finder, NetGene2, and Fruitfly were used to predict the influence of the novel mutations. The pathogenicity of the mutation was interpreted according to the ACMG guidelines. Results: In this study, six patients from four different Vietnamese families were collected for genetic analysis at The Center for Gene and Protein Research and The Department of Molecular Pathology Faculty of Medical Technology, Hanoi Medical University, Hanoi, Vietnam. Based on clinical symptoms and serum creatine kinase (CK) levels, the patients were diagnosed with limb-girdle muscular dystrophies. Five mutations, including four (c.229C>T, p.Arg77Cys; exon one to three deletion; c.983 + 5G>C; and c.257_258insTGGCT, p.Phe88Leufs*125) in the SGCA gene and one (c.946-4_946-1delACAG) in the CAPN3 gene, were detected in six LGMD patients from four unrelated Vietnamese families. Two homozygous mutations (c.983 + 5G>C and c.257_258insTGGCT) in the SGCA gene were novel. These mutations were identified as the cause of the disease in the patients. Conclusion: Our results contribute to the general understanding of the etiology of the disease and provide the basis for definitive diagnosis and support genetic counseling and prenatal screening.

The first Vietnamese patient who presented late onset of pantothenate kinase-associated neurodegeneration diagnosed by whole exome sequencing: A case report.

RATIONALE: Pantothenate kinase-associated neurodegeneration (PKAN), also called Hallervorden-Spatz syndrome, is a rare autosomal recessive disease associated with brain iron accumulation and characterized by progressive dystonia, dementia, and dysarthria symptoms. PKAN, caused by a defective pantothenate kinase 2 (PANK2) gene, is the most common neurodegeneration with a brain iron accumulation (NBIA) group. The "eye of the tiger" sign in the magnetic resonance imaging demonstrated a bilateral hyperintense signal in the basal ganglia region on T2-weighted images, which is a characteristic feature of the diagnosis. PKAN is classified into 2 main types. The early-onset type (classic type) with rapid progression is characterized by symptoms of gait impairment and dystonia leading to loss of ambulation in early childhood. In the later-onset type (atypical type), slow progression usually takes place in the second decade of life with symptoms of neurodegeneration, dystonia, dysarthria, rigidity, choreoathetosis, and motor impairment. Until now, PKAN patients have only been reported in a few countries in Asia such as China, Korea, India, Iran, Taiwan, and Thailand. PATIENT CONCERNS: Here we report the first case of PKAN in Vietnam. The patient had a late onset but the disease progresses rapidly with symptoms of dyskinesia, dysphagia, and difficulty speaking. DIAGNOSES: Pantothenate kinase-associated neurodegeneration. INTERVENTIONS: Whole exome sequencing was performed to identify heterozygous mutations in the PANK2 gene (NM_153638.4) (c.856C>T, p.Arg286Cys and c.1351C>T, p.Arg451Ter) that has been confirmed as the cause of the disease. OUTCOMES: In this study, the first Vietnamese patient with late-onset PKAN was diagnosed by the whole exome sequencing method. LESSONS: The patient's case marks an important milestone for the first case in Vietnam. The results of the study will provide a scientific basis for clinicians in the diagnosis and genetic counseling of patients.

Merosin-deficient congenital muscular dystrophy type 1a: detection of LAMA2 variants in Vietnamese patients.

Background: Merosin-deficient congenital muscular dystrophy type 1A (MDC1A), also known as laminin-α2 chain-deficient congenital muscular dystrophy (LAMA2-MD), is an autosomal recessive disease caused by biallelic variants in the LAMA2 gene. In MDC1A, laminin- α2 chain expression is absent or significantly reduced, leading to some early-onset clinical symptoms including severe hypotonia, muscle weakness, skeletal deformity, non-ambulation, and respiratory insufficiency. Methods: Six patients from five unrelated Vietnamese families presenting with congenital muscular dystrophy were investigated. Targeted sequencing was performed in the five probands. Sanger sequencing was carried out in their families. Multiplex ligation-dependent probe amplification was performed in one family to examine an exon deletion. Results: Seven variants of the LAMA2 (NM_000426) gene were identified and classified as pathogenic/likely pathogenic variants using American College of Medical Genetics and Genomics criteria. Two of these variants were not reported in the literature, including c.7156-5_7157delinsT and c.8974_8975insTGAT. Sanger sequencing indicated their parents as carriers. The mothers of family 4 and family 5 were pregnant and a prenatal testing was performed. The results showed that the fetus of the family 4 only carries c.4717 + 5G>A in the heterozygous form, while the fetus of the family 5 carries compound heterozygous variants, including a deletion of exon 3 and c.4644C>A. Conclusion: Our findings not only identified the underlying genetic etiology for the patients, but also provided genetic counseling for the parents whenever they have an offspring.

Novel mutations in unrelated Vietnamese patients with chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder (PID) due to genetic defects in the NADPH oxidase of phagocytes. Affected patients become susceptible to infections such as pneumonia, diarrhea, and skin ulcer types. The patients require life-long treatment with prophylactic antibiotics, antifungals, or hematopoietic stem cell transplantation (HSCT) therapy. Early, accurate diagnosis will contribute to the life-prolonging of patients with CGD. This study's aim is to identify the mutation related to the disease. CASE PRESENTATION: Six patients from different Vietnamese families were collected for genetic analysis at Allergy, Immunology, and Rheumatology Department, Vietnam National Hospital Pediatrics. They were diagnosed with CGD by flow cytometry test with the conversion of dihydrorhodamine (DHR) 123 to rhodamine 123. METHODS: We performed whole exome sequencing (WES) as a tool for detecting novel mutations. The mutations were confirmed by the Sanger sequencing method in patients and their families. The influence of the mutations was predicted with the in silico analysis tools: PROVEAN, SIFT, PolyPhen 2, Mutation Taster, and MaxEntScan. RESULTS: In this study, five mutations were found in six unrelated patients with CGD from different Vietnamese families. Three novel pathogenic mutations were detected including one mutation (c.45+2 T>G) in the CYBB gene and two mutations (c.187_188insA and c.289G>C) in the NCF2 gene. CONCLUSIONS: Our results of CGD-related mutations contribute to the general understanding of the etiology of the disease and emphasize that WES sequencing can be used as a tool to help to diagnose carriers as well as assist in genetic counseling and prenatal screening.

Biliary atresia combined Wilson disease identified by whole exome sequencing in Vietnamese patient with severe liver failure.

RATIONALE: Hepatobiliary diseases such as biliary atresia (BA), Wilson disease, and progressive familial intrahepatic cholestasis are common causes of morbidity and mortality in young children. Affected patients progress rapidly to end-stage cirrhosis and require liver transplantation or die. Mutations in many genes have been identified to play an important role in the pathogenesis of hepatobiliary diseases. PATIENT CONCERNS AND DIAGNOSIS: In this study, we identified mutations in an 8-year-old girl who had severe liver failure. The patient was first diagnosed with BA at 2.5 months of age and has undergone Kasai surgery to connect the umbilical cord and jejunum. After that, the patient suddenly had unusual developments with symptoms of jaundice, acute liver failure with hemolysis. She was tested and diagnosed with Wilson disease. INTERVENTIONS AND OUTCOMES: She was treated according to the regimen for a patient with Wilson disease but had abnormal progress leading to severe liver failure. Genetic analysis was performed by whole exome sequencing and Sanger sequencing methods. The genetic analysis revealed that the patient had a homozygous mutation (p.Gly17Glyfs77∗) in the KRT18 gene, a double heterozygous mutation (p.Ser105∗ and p.Pro992Leu) in the ATP7B gene, and a homozygous variant (p.Val444Ala) in the ABCB11 gene. In silico prediction of mutations indicated that these mutations are the cause of the severe liver failure in the patient. LESSON: This is a rare clinical case of a BA patient combined with Wilson disease. Our results suggested that whole exome sequencing is an effective diagnostic tool and emphasizes the importance of early diagnosis and appropriate management to save lives and prevent serious complications in the patient.

Effect of Magnetic Magnetite (Fe3O4) Nanoparticle Size on Arsenic (V) Removal from Water.

Magnetic magnetite (Fe3O4) nanoparticles with average sizes of 5.11, 10.53, and 14.76 nm were synthesized by the chemical co-precipitation method. The surface area of Fe3O4 nanoparticles (average size of 5.11 nm) had the largest value of 167 m²/g. The adsorption capacity for removing arsenic (As(V)) from water at 3 ppm concentration was investigated by atomic absorption spectroscopy. Results showed that the As(V) adsorption capacity of Fe3O4 was dependent on particle size. The maximum absorption efficiency (Hmax) reached 99.02%, the equilibrium time was 30 min; the maximum Langmuir isotherm adsorption capacity was 14.46 mg/g with Fe3O4 nanoparticle an average size of 5 nm. The results indicate that reducing the size of Fe3O4 nanoparticles is a promised way for As(V) ion removal from water and wastewater treatment.

The role of p.Val444Ala variant in the ABCB11 gene and susceptibility to biliary atresia in Vietnamese patients.

ABSTRACT: Biliary atresia (BA) is the most serious type of obstructive cholangiopathy that occurs in infants. BA can be the cause of death in children under 2 years if untreated early. However, the etiology of the disease is not known. BA is considered to be the result of the destruction of the bile duct system including the accumulation of bile acids. The bile salt export pump, a transporter protein encoded by the ABCB11 gene, plays the main role in the exportation and accumulation of bile acids. The p.Val444Ala variant in this gene is known to be associated with many cholestatic diseases. However, to date no study have been performed to evaluate the association of this variant with susceptibility to the risk of BA. In this study, we aimed to identify the frequency of p.Val444Ala variant and the risk of BA in Vietnamese patients.The polymerase chain reaction (PCR)- restriction fragment length polymorphism method was used to determine the frequency of alleles c.1331T>C (p.Val444Ala, rs2287622) in the ABCB11 gene in 266 Vietnamese patients with BA and 150 healthy people. The gene segment containing the variant was amplified by PCR with specific primers, after that the PCR products were cut by HaeIII restriction enzyme and analyzed on agarose gel to determine the genotypes. The frequency of alleles was assessed statistically to determine the association between these alleles and the risk of disease in patients.In our study, the frequency of alleles c.1331T>C (p.Val444Ala, rs2287622) in the ABCB11 gene was investigated the first time in the patients with BA. The results showed that CC and TC genotypes were significantly different between BA patients and healthy people (P < .01), and the C allele was associated with an increased risk of BA (odds ratio = 2.47; 95% confidence interval: 1.84-3.32; P < .01). The initial results of clinical, biochemical, and genetic analysis in our study suggested that the p.Val444Ala variant in the ABCB11 gene may be a susceptibility factor for the disease in Vietnamese patients with BA. These results provided new insights into the role of this ABCB11 variant in the pathogenesis of BA.

Transcriptome Sequencing and Analysis of Changes Associated with Insecticide Resistance in the Dengue Mosquito (Aedes aegypti) in Vietnam.

The mosquito Aedes aegypti is a transmission vector for dangerous epidemic diseases in humans. Insecticides have been used as the most general vector control method in the world. However, Ae. aegypti have developed many resistant mechanisms such as reduced neuronal sensitivity to insecticides (target-site resistance), enhanced insecticide metabolism (metabolic resistance), altered transport, sequestration, and other mechanisms. It has become a major problem for vector control programs. Transcriptome sequencing and bioinformatic analysis were used to compare transcription levels between a susceptible strain (Bora7) and a resistant strain (KhanhHoa7) collected from the field. A total of 161 million Illumina reads, including 66,076,678 reads from the Bora7 strain and 69,606,654 reads from the KhanhHoa7 strain, were generated and assembled into 11,174 genes. A comparison of the KhanhHoa7 transcriptome to that of Bora7 showed 672 upregulated genes and 488 downregulated genes. We identified the highly upregulated genes: cytochrome P450 4C1, 4C3, 4C21, 4D1, 4D1 isoform X2, 4D2, 4D2 isoform X2, 4G15, 6A2, 6A8, 6D3, and 9E2; Glutathione S transferase (GST1), UGT1-3, 1-7, 2B15, and 2B37; binding cassette transporter (ABC) transporter F family member 4 and ABC transporter G family member 20. Interestingly, there was a significant increase in the expression of the genes such as CYP9E2 (8.3-fold), CYP6A8 (5.9-fold), CYP6D3 (5.4-fold), CYP4C21 (5.4-fold), CYP4G15 (5.2-fold), GST1 (3.5-fold), and ABC transporter 4 (2.1-fold). Our results suggested a potential relationship between the expression of the genes in metabolic processes and insecticide resistance in the studied strain. These results may contribute to the understanding of the mechanisms of insecticide resistance in Ae. aegypti.