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1.
J Med Entomol ; 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38381589

RESUMO

Spiroplasma (Mycoplasmatales: Spiroplasmataceae) is one of the most widely distributed symbionts of arthropods. Spiroplasma species can infect their hosts via vertical or horizontal transmission. However, the mode of transmission of Spiroplasma between different arthropod taxa has not been elucidated. In this study, we investigated the potential for the transmission of Spiroplasma to non-native arthropod species, using 2 Spiroplasma spp. isolated from ticks, namely Spiroplasma ixodetis and Spiroplasma mirum, and 3 species of mosquito laboratory colonies, namely Aedes albopictus, Aedes aegypti, and Culex pipiens pallens (Diptera: Culicidae). After feeding the adult mosquitoes with Spiroplasma-containing artificial meals, they were kept at 25 °C for 10 days. Homogenates prepared from Spiroplasma-fed mosquitoes were used to re-isolate Spiroplasma using the in vitro culture method. Nine weeks after culture initiation, the presence of Spiroplasma was tested using the polymerase chain reaction (PCR). The results revealed that only S. ixodetis was detected from all 3 species of mosquitoes and re-isolated from 2 of them. The differences in the infection ability of different Spirolasma species could be attributed to several factors, including environmental effects. Nevertheless, this is the first experimental demonstration of Spiroplasma transmission among different arthropod taxa. Further studies are needed to elucidate the evolutionary mechanism that supports the survival of Spiroplasma in nature.

2.
Sci Rep ; 13(1): 18165, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37875565

RESUMO

Mosquitoes interact with various organisms in the environment, and female mosquitoes in particular serve as vectors that directly transmit a number of microorganisms to humans and animals by blood-sucking. Comprehensive analysis of mosquito-borne viruses has led to the understanding of the existence of diverse viral species and to the identification of zoonotic arboviruses responsible for significant outbreaks and epidemics. In the present study on mosquito-borne bunyaviruses we employed a broad-spectrum RT-PCR approach and identified eighteen different additional species in the Phenuiviridae family and also a number of related but unclassified bunyaviruses in mosquitoes collected in Zambia. The entire RNA genome segments of the newly identified viruses were further analyzed by RNA sequencing with a ribonuclease R (RNase R) treatment to reduce host-derived RNAs and enrich viral RNAs, taking advantage of the dsRNA panhandle structure of the bunyavirus genome. All three or four genome segments were identified in eight bunyavirus species. Furthermore, L segments of three different novel viruses related to the Leishbunyaviridae were found in mosquitoes together with genes from the suspected host, the Crithidia parasite. In summary, our virus detection approach using a combination of broad-spectrum RT-PCR and RNA sequencing analysis with a simple virus enrichment method allowed the discovery of novel bunyaviruses. The diversity of bunyaviruses is still expanding and studies on this will allow a better understanding of the ecology of hematophagous mosquitoes.


Assuntos
Arbovírus , Culicidae , Orthobunyavirus , Vírus de RNA , Animais , Humanos , Feminino , Mosquitos Vetores , Orthobunyavirus/genética , Vírus de RNA/genética , Arbovírus/genética
3.
Acta Parasitol ; 68(4): 862-868, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37831281

RESUMO

PURPOSE: Mosquitoes are important vectors that carry disease-causing agents that can affect humans and animals. DNA barcoding is a complementary identification which can be used to validate morphological characterization of mosquito species. The objectives of this study were to identify the mitochondrial sequence of the COI gene and to construct a molecular phylogeny based on the genetic divergence of the mosquito species studied. METHODS: In this study, DNA extraction and the amplification of the mitochondrial cytochrome oxidase subunit I genes (COI) were performed on pooled mosquito samples collected in Nay Pyi Taw area, Myanmar. RESULTS: Fragments of the COI gene showed 99-100% identity with sequences of Aedes aegypti, Armigeres subalbatus, Culex pipiens complex, and Cx. quinquefasciatus, respectively, deposited in GenBank. This study categorized two haplotypes from each Ar. subalbatus and Cx. pipiens complex COI gene sequence, as well as three haplotypes from Cx. quinquefasciatus COI gene sequences. The highest haplotype diversity and nucleotide diversity were observed in the Ar. subalbatus population (Hd = 1.0000; π = 0.0033), followed by the Cx. pipiens complex and Cx. quinquefasciatus populations. CONCLUSION: This study provides useful information on the molecular identification and genetic diversity of mosquito vectors with medical and veterinary significance, which may assist in the improvement of mosquito control programs.


Assuntos
Aedes , Culex , Animais , Humanos , Culex/genética , Aedes/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mianmar , Mosquitos Vetores/genética
4.
Med Vet Entomol ; 37(3): 542-549, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37017293

RESUMO

Dirofilariosis, known as one of the most widespread vector-borne zoonotic diseases, is caused by several different species of the nematodes of the genus Dirofilaria, which can be transmitted by Culex, Anopheles and Aedes mosquito vectors. In order to identify key vector mosquitoes of filarial parasites in Myanmar, mosquitoes were collected during three different seasons (summer, rainy and winter) in three townships in Nay Pyi Taw area, Myanmar. DNA extraction and polymerase chain reaction (PCR) analyses were conducted for 185 mosquito pools, with each pool containing 1-10 mosquitoes. Dirofilaria immitis was detected in 20 pools of Culex pipiens complex mosquitoes. The minimum infection rate of mosquitoes was found to be 16.33. The small subunit ribosomal RNA (12S rDNA) gene targeted PCR revealed that the sequences obtained were completely identical to the sequences of D. immitis derived from dogs in China, Brazil and France. The sequences obtained from mitochondrial cytochrome oxidase subunit I (COI) gene PCR exhibited 100% identity with the sequences of D. immitis derived from dogs in Bangladesh, Iran, Japan and Thailand, as well as humans in Iran and Thailand, and mosquitoes in Germany and Hungary. The findings of this study demonstrated that the mosquito species of Cx. pipiens complex are potential mosquito vectors for dirofilariosis in Myanmar.


Assuntos
Aedes , Culex , Dirofilaria immitis , Dirofilariose , Doenças do Cão , Humanos , Animais , Cães , Dirofilaria immitis/genética , Culex/genética , Mianmar , Dirofilariose/parasitologia , Aedes/parasitologia , Mosquitos Vetores , Doenças do Cão/parasitologia
5.
J Med Entomol ; 60(1): 122-130, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36373613

RESUMO

Controlling mosquitoes is vital for counteracting the rising number of mosquito-borne illnesses. Vector control requires the implementation of various measures; however, current methods lack complete effectiveness, and new control agents or substances are urgently needed. Therefore, this study developed a nonwoven fabric sheet coated with hydroxyapatite-binding silver/titanium dioxide compound (hydroxyapatite-binding silver/titanium dioxide sheet [HATS])and evaluated its effectiveness on all stages of laboratory Aedes aegypti (Linnaeus); Diptera: Culicidae and Anopheles dirus (Peyton & Harrison); Diptera: Culicidae. We reared larvae with HATS and control sheets and assessed their mortality, emergence, and hatching rates. The submersion rates of engorged female mosquitoes in submerged HATS and control sheets were also compared. The HATS strongly affected mosquito development, resulting in high mortality rates (mean ± SE) of 99.66 ± 0.58% (L1-L2) and 91.11 ± 9.20% (L3-L4) for Ae. aegypti and 100% of both stages for An. dirus. In contrast, mosquitoes raised in the control sheet showed relatively high survival rates of 92.33 ± 3.21% (L1-L2) and 95.67 ± 0.58% (L3-L4) for Ae. aegypti and 86.07 ± 3.53% (L1-L2) and 92.01 ± 8.67% (L3-L4) for An. dirus. Submersion of engorged females was found in the HATS oviposition cup, leading to a decreased number of eggs and a low hatching rate compared to that of the control. Overall, HATS may be a useful new control method for Ae. aegypti and An. dirus.


Assuntos
Aedes , Anopheles , Culicidae , Feminino , Animais , Prata/química , Mosquitos Vetores , Larva , Controle de Mosquitos/métodos , Hidroxiapatitas
6.
PLoS Negl Trop Dis ; 16(6): e0010420, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35653390

RESUMO

Rift valley fever (RVF) is a mosquito-borne disease of animals and humans. Although RVF outbreaks are usually reported at 5-15-year intervals in sub-Saharan Africa, Zambia has experienced an unusually long inter-epizootic/-epidemic period of more than three decades. However, serological evidence of RVF virus (RVFV) infection in domestic ruminants during this period underscores the need for comprehensive investigation of the mechanisms of virus perpetuation and disease emergence. Mosquitoes (n = 16,778) captured from eight of the ten provinces of Zambia between April 2014 and May 2019 were pooled (n = 961) and screened for RVFV genome by a pan-phlebo RT-PCR assay. Aedes mosquito pools (n = 85) were further screened by nested RT-PCR assay. Sera from sheep (n = 13), goats (n = 259) and wild ungulates (n = 285) were screened for RVFV antibodies by ELISA while genome detection in pooled sera (n = 276) from domestic (n = 248) and wild ungulates (n = 37) was performed by real-time RT-PCR assay. To examine the association between the long inter-epizootic period and climatic variables, we examined El Niño-Southern Oscillation indices, precipitation anomalies, and normalized difference vegetation index. We then derived RVF risk maps by exploring climatic variables that would favor emergence of primary RVFV vectors. While no RVFV genome could be detected in pooled mosquito and serum samples, seroprevalence was significantly high (OR = 8.13, 95% CI [4.63-14.25]) in wild ungulates (33.7%; 96/285) compared to domestic ruminants (5.6%; 16/272). Retrospective analysis of RVF epizootics in Zambia showed a positive correlation between anomalous precipitation (La Niña) and disease emergence. On risk mapping, whilst northern and eastern parts of the country were at high risk, domestic ruminant population density was low (< 21 animals/km2) in these areas compared to low risk areas (>21 animals/km2). Besides evidence of silent circulation of RVFV and the risk of disease emergence in some areas, wildlife may play a role in the maintenance of RVFV in Zambia.


Assuntos
Culicidae , Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais , Surtos de Doenças/veterinária , Mosquitos Vetores , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Vírus da Febre do Vale do Rift/genética , Ruminantes , Estudos Soroepidemiológicos , Ovinos , Zâmbia/epidemiologia
7.
BMC Res Notes ; 15(1): 44, 2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35151353

RESUMO

OBJECTIVE: To disseminate the portable sequencer MinION in developing countries for the main purpose of battling infectious diseases, we found a consortium called Global Research Alliance in Infectious Diseases (GRAID). By holding and inviting researchers both from developed and developing countries, we aim to train the participants with MinION's operations and foster a collaboration in infectious diseases researches. As a real-life example in which resources are limited, we describe here a result from a training course, a metagenomics analysis from two blood samples collected from a routine cattle surveillance in Kulan Progo District, Yogyakarta Province, Indonesia in 2019. RESULTS: One of the samples was successfully sequenced with enough sequencing yield for further analysis. After depleting the reads mapped to host DNA, the remaining reads were shown to map to Theileria orientalis using BLAST and OneCodex. Although the reads were also mapped to Clostridium botulinum, those were found to be artifacts derived from the cow genome. An effort to construct a consensus sequence was successful using a reference-based approach with Pomoxis. Hence, we concluded that the asymptomatic cow might be infected with T. orientalis and showed the usefulness of sequencing technology, specifically the MinION platform, in a developing country.


Assuntos
Doenças Transmissíveis , Sequenciamento de Nucleotídeos em Larga Escala , Animais , Bovinos , Genoma , Metagenômica , Análise de Sequência de DNA
8.
Sci Rep ; 11(1): 4883, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649491

RESUMO

Tick-borne flaviviruses (TBFVs) infect mammalian hosts through tick bites and can cause various serious illnesses, such as encephalitis and hemorrhagic fevers, both in humans and animals. Despite their importance to public health, there is limited epidemiological information on TBFV infection in Africa. Herein, we report that a novel flavivirus, Mpulungu flavivirus (MPFV), was discovered in a Rhipicephalus muhsamae tick in Zambia. MPFV was found to be genetically related to Ngoye virus detected in ticks in Senegal, and these viruses formed a unique lineage in the genus Flavivirus. Analyses of dinucleotide contents of flaviviruses indicated that MPFV was similar to those of other TBFVs with a typical vertebrate genome signature, suggesting that MPFV may infect vertebrate hosts. Bioinformatic analyses of the secondary structures in the 3'-untranslated regions (UTRs) revealed that MPFV exhibited unique exoribonuclease-resistant RNA (xrRNA) structures. Utilizing biochemical approaches, we clarified that two xrRNA structures of MPFV in the 3'-UTR could prevent exoribonuclease activity. In summary, our findings provide new information regarding the geographical distribution of TBFV and xrRNA structures in the 3'-UTR of flaviviruses.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Infecções por Flavivirus/virologia , RNA Viral , Carrapatos/virologia , Animais , Vírus da Encefalite Transmitidos por Carrapatos/classificação , Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Infecções por Flavivirus/epidemiologia , Especificidade de Hospedeiro , Humanos , Conformação de Ácido Nucleico , Zâmbia/epidemiologia
9.
Int J Mol Sci ; 21(20)2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33053895

RESUMO

Efforts to determine the mosquito genes that affect dengue virus replication have identified a number of candidates that positively or negatively modify amplification in the invertebrate host. We used deep sequencing to compare the differential transcript abundances in Aedes aegypti 14 days post dengue infection to those of uninfected A. aegypti. The gene lethal(2)-essential-for-life [l(2)efl], which encodes a member of the heat shock 20 protein (HSP20) family, was upregulated following dengue virus type 2 (DENV-2) infection in vivo. The transcripts of this gene did not exhibit differential accumulation in mosquitoes exposed to insecticides or pollutants. The induction and overexpression of l(2)efl gene products using poly(I:C) resulted in decreased DENV-2 replication in the cell line. In contrast, the RNAi-mediated suppression of l(2)efl gene products resulted in enhanced DENV-2 replication, but this enhancement occurred only if multiple l(2)efl genes were suppressed. l(2)efl homologs induce the phosphorylation of eukaryotic initiation factor 2α (eIF2α) in the fruit fly Drosophila melanogaster, and we confirmed this finding in the cell line. However, the mechanism by which l(2)efl phosphorylates eIF2α remains unclear. We conclude that l(2)efl encodes a potential anti-dengue protein in the vector mosquito.


Assuntos
Aedes/genética , Aedes/virologia , Vírus da Dengue/fisiologia , Dengue/virologia , Proteínas de Choque Térmico HSP20/genética , Proteínas de Insetos/genética , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , Animais , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Transcriptoma , Replicação Viral
10.
Viruses ; 12(9)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32878170

RESUMO

Bluetongue (BT) is an arthropod-borne viral disease of ruminants with serious trade and socio-economic implications. Although the disease has been reported in a number of countries in sub-Saharan Africa, there is currently no information on circulating serotypes and disease distribution in Zambia. Following surveillance for BT in domestic and wild ruminants in Zambia, BT virus (BTV) nucleic acid and antibodies were detected in eight of the 10 provinces of the country. About 40% (87/215) of pooled blood samples from cattle and goats were positive for BTV nucleic acid, while one hartebeest pool (1/43) was positive among wildlife samples. Sequence analysis of segment 2 revealed presence of serotypes 3, 5, 7, 12 and 15, with five nucleotypes (B, E, F, G and J) being identified. Segment 10 phylogeny showed Zambian BTV sequences clustering with Western topotype strains from South Africa, intimating likely transboundary spread of BTV in Southern Africa. Interestingly, two Zambian viruses and one isolate from Israel formed a novel clade, which we designated as Western topotype 4. The high seroprevalence (96.2%) in cattle from Lusaka and Central provinces and co-circulation of multiple serotypes showed that BT is widespread, underscoring the need for prevention and control strategies.


Assuntos
Vírus Bluetongue/isolamento & purificação , Bluetongue/virologia , Doenças dos Bovinos/virologia , Doenças das Cabras/virologia , Doenças dos Ovinos/virologia , Animais , Bluetongue/epidemiologia , Vírus Bluetongue/classificação , Vírus Bluetongue/genética , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças das Cabras/epidemiologia , Cabras , Filogenia , Ovinos , Doenças dos Ovinos/epidemiologia , Zâmbia/epidemiologia
11.
Viruses ; 12(9)2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32933075

RESUMO

To monitor the arthropod-borne virus transmission in mosquitoes, we have attempted both to detect and isolate viruses from 3304 wild-caught female mosquitoes in the Livingstone (Southern Province) and Mongu (Western Province) regions in Zambia in 2017. A pan-flavivirus RT-PCR assay was performed to identify flavivirus genomes in total RNA extracted from mosquito lysates, followed by virus isolation and full genome sequence analysis using next-generation sequencing and rapid amplification of cDNA ends. We isolated a newly identified Barkedji virus (BJV Zambia) (10,899 nt) and a novel flavivirus, tentatively termed Barkedji-like virus (BJLV) (10,885 nt) from Culex spp. mosquitoes which shared 96% and 75% nucleotide identity with BJV which has been isolated in Israel, respectively. These viruses could replicate in C6/36 cells but not in mammalian and avian cell lines. In parallel, a comparative genomics screening was conducted to study evolutionary traits of the 5'- and 3'-untranslated regions (UTRs) of isolated viruses. Bioinformatic analyses of the secondary structures in the UTRs of both viruses revealed that the 5'-UTRs exhibit canonical stem-loop structures, while the 3'-UTRs contain structural homologs to exoribonuclease-resistant RNAs (xrRNAs), SL-III, dumbbell, and terminal stem-loop (3'SL) structures. The function of predicted xrRNA structures to stop RNA degradation by Xrn1 exoribonuclease was further proved by the in vitro Xrn1 resistance assay.


Assuntos
Exorribonucleases/genética , Flavivirus/enzimologia , Flavivirus/genética , Insetos/virologia , Regiões 3' não Traduzidas , Animais , Linhagem Celular , Culex/virologia , Culicidae/virologia , Exorribonucleases/química , Exorribonucleases/classificação , Feminino , Flavivirus/isolamento & purificação , Genoma Viral , Proteínas de Insetos/genética , Israel , Filogenia , Zâmbia
12.
Arch Virol ; 164(8): 2165-2170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154511

RESUMO

Zika virus (ZIKV) circulation occurs between non-human primates (NHPs) in a sylvatic transmission cycle. To investigate evidence of flavivirus infection in NHPs in Zambia, we performed a plaque reduction neutralization test (PRNT) to quantify neutralizing antibodies. PRNT revealed that sera from NHPs (African green monkeys and baboons) exhibited neutralizing activity against ZIKV (34.4%; 33/96), whereas a PRNT for yellow fever virus using NHP sera showed no neutralization activity. ZIKV genomic RNA was not detected in splenic tissues from NHPs, suggesting that the presence of anti-ZIKV neutralizing antibodies represented resolved infections. Our evidence suggests that ZIKV is maintained in NHP reservoirs in Zambia.


Assuntos
Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia , Zika virus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Dengue/imunologia , Infecções por Flavivirus/imunologia , Infecções por Flavivirus/virologia , Primatas , Testes Sorológicos/métodos , Zâmbia
13.
PLoS Negl Trop Dis ; 13(6): e0007480, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31158221

RESUMO

Detection and sequencing of chikungunya virus (CHIKV) genome was performed using a combination of a modified reverse transcription loop-mediated isothermal amplification (RT-LAMP) method and a MinION sequencer. We developed the protocol for drying all the reagents for the RT-LAMP in a single reaction tube. Using this system, the CHIKV genome was effectively amplified under isothermal conditions, and used as a template for MinION sequencing with a laptop computer. Our in-house RT-LAMP method and MinION sequencing system were also validated with RNAs and serum samples from recent outbreaks of CHIKV patients in Brazil. The obtained sequence data confirmed the CHIKV outbreaks and identified the genotype. In summary, our established inexpensive on-site genome detection and sequencing system is applicable for both diagnosis of CHIKV infected patients and genotyping of the CHIKV virus in future outbreak in remote areas.


Assuntos
Febre de Chikungunya/diagnóstico , Vírus Chikungunya/isolamento & purificação , Técnicas de Genotipagem/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Análise de Sequência de DNA/métodos , Brasil , Febre de Chikungunya/virologia , Vírus Chikungunya/classificação , Vírus Chikungunya/genética , Dessecação , Humanos , Transcrição Reversa , Temperatura
14.
Parasit Vectors ; 12(1): 168, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975188

RESUMO

BACKGROUND: Flea-borne spotted fever is a zoonosis caused by Rickettsia felis, a Gram-negative obligate intracellular bacterium. The disease has a worldwide distribution including western and eastern sub-Saharan Africa where it is associated with febrile illness in humans. However, epidemiology and the public health risks it poses remain neglected especially in developing countries including Zambia. While Ctenocephalides felis (cat fleas) has been suggested to be the main vector, other arthropods including mosquitoes have been implicated in transmission and maintenance of the pathogen; however, their role in the epidemiological cycle remains to be elucidated. Thus, the aim of this study was to detect and characterize R. felis from animal hosts and blood-sucking arthropod vectors in Zambia. METHODS: Dog blood and rodent tissue samples as well as cat fleas and mosquitoes were collected from various areas in Zambia. DNA was extracted and screened by polymerase chain reaction (PCR) targeting genus Rickettsia and amplicons subjected to sequence analysis. Positive samples were further subjected to R. felis-specific real-time quantitative polymerase chain reactions. RESULTS: Rickettsia felis was detected in 4.7% (7/150) of dog blood samples and in 11.3% (12/106) of rodent tissue samples tested by PCR; this species was also detected in 3.7% (2/53) of cat fleas infesting dogs, co-infected with Rickettsia asembonensis. Furthermore, 37.7% (20/53) of cat flea samples tested positive for R. asembonensis, a member of spotted fever group rickettsiae of unknown pathogenicity. All the mosquitoes tested (n = 190 pools) were negative for Rickettsia spp. CONCLUSIONS: These observations suggest that R. felis is circulating among domestic dogs and cat fleas as well as rodents in Zambia, posing a potential public health risk to humans. This is because R. felis, a known human pathogen is present in hosts and vectors sharing habitat with humans.


Assuntos
Doenças do Gato/microbiologia , Doenças do Cão/microbiologia , Infecções por Rickettsia/veterinária , Rickettsia felis/isolamento & purificação , Doenças dos Roedores/microbiologia , Sifonápteros/microbiologia , Animais , Doenças do Gato/parasitologia , Gatos , Cães , Tipagem Molecular , Reação em Cadeia da Polimerase , Infecções por Rickettsia/microbiologia , Roedores , Zâmbia
15.
Inflamm Intest Dis ; 3(3): 145-154, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30820436

RESUMO

BACKGROUND: Both environmental and genetic factors have been implicated in the induction of autoimmune disease. Therefore, it is important to understand the pathophysiological significance of the gut microbiota and host genetic background that contribute to an autoimmune disease such as inflammatory bowel disease (IBD). We have previously reported that mice deficient for suppressor of cytokine signaling-1 (SOCS1), in which SOCS1 expression was restored in T and B cells on an SOCS1-/- background (SOCS1-/-Tg mice), developed systemic autoimmune diseases accompanied by spontaneous colitis. METHODS: To investigate whether the proinflammatory genetic background affects the gut microbiota, we used SOCS1-/-Tg mice as a model of spontaneous chronic colitis. Fecal samples were collected from SOCS1-/-Tg mice and SOCS1+/+Tg (control) mice at 1 and 6 months of age, and the fecal bacterial 16S ribosomal RNA genes were sequenced using the Illumina MiSeq platform. RESULTS: Gut microbial diversity was significantly reduced and the intestinal bacterial community composition changed in SOCS1-/-Tg mice in comparison with the control mice. Interestingly, the population of Prevotella species, which is known to be elevated in ulcerative colitis and colorectal cancer patients, was significantly increased in SOCS1-/-Tg mice regardless of age. CONCLUSION: Taken together, these results suggest that the proinflammatory genetic background owing to SOCS1 deficiency causes dysbiosis of the gut microbiota, which in turn generates a procolitogenic environment.

16.
Biochem Biophys Res Commun ; 504(1): 245-250, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30190125

RESUMO

Sialadenitis is an inflammatory condition affecting the salivary glands including the parotid, submandibular, and sublingual glands. There are several different types of sialadenitis, each with different sites of predilection. However, the pathogenic mechanism underlying the tissue specificity of sialadenitis is largely unknown. TRAF6 is a cytoplasmic adaptor protein that is necessary for the activation of dendritic cells in response to Toll-like receptor ligands, thereby regulating innate immune responses. We previously demonstrated that T cell-specific TRAF6-deficient mice (TRAF6ΔT mice) spontaneously develop systemic inflammatory disease. Here, we show that salivary secretion is reduced in TRAF6ΔT mice due to sialadenitis that occurs in the parotid and submandibular glands, but not the sublingual glands. Consistent with pathological findings, both CD4+ and CD8+ T cells predominantly infiltrated the submandibular glands; however, sublingual infiltration was rare in TRAF6ΔT mice. The TH1 cytokine IFN-γ, the TH1 cell attractant chemokine CCL2, and its cognate receptor CCR2 were upregulated concomitantly in both the submandibular and sublingual glands. Interestingly, the TH17 cell attractant chemokine CCL20 and its cognate receptor CCR6 were selectively increased in the submandibular glands, but not in the sublingual glands of TRAF6ΔT mice. Thus, the expression of TRAF6 in T cells might be implicated in tissue-specific sialadenitis by regulating the chemokine-chemokine receptor system.


Assuntos
Doenças Autoimunes/metabolismo , Quimiocinas/metabolismo , Receptores de Quimiocinas/metabolismo , Sialadenite/metabolismo , Linfócitos T/metabolismo , Fator 6 Associado a Receptor de TNF/genética , Animais , Quimiocina CCL2/metabolismo , Citoplasma/metabolismo , Inflamação , Camundongos , Camundongos Knockout , Glândula Parótida/metabolismo , Receptores CCR2/metabolismo , Glândulas Salivares/metabolismo , Sialadenite/imunologia , Glândula Submandibular/metabolismo , Células Th1/metabolismo , Células Th17/metabolismo , Regulação para Cima
17.
Clin Exp Metastasis ; 35(8): 785-796, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30255290

RESUMO

Lymphangiogenesis plays a crucial role in promoting cancer metastasis to sentinel lymph nodes (LNs) and beyond. Increasing data have shown that simvastatin, a cholesterol-lowering medication for the prevention of cardiovascular diseases, is involved in tumor growth and dissemination, and endothelial functions. This study aimed to investigate the potential effect of simvastatin on lymphatic formation and LN metastasis. Tumor models were established by subcutaneous injection of B16-F10 melanoma cells into mouse hind footpads. Simvastatin was administered (0.2 µg/g, intraperitoneal injection, IP) every other day for a total of eight times. Tissue samples were removed and examined by immunohistochemical staining and reverse transcription-polymerase chain reaction (RT-PCR) techniques. The lymphatics of LN, skin, liver, and lung exhibited morphological changes, and LN weight and metastatic area of the tumor group treated with simvastatin was lower than that of the untreated tumor group. Analysis of lymphatic size, area fraction, and lymphatic vessel density showed tissue specificity and variation to melanoma carcinogenesis in the simvastatin-treated group compared with the untreated group. In addition, LNs and cutaneous tissues showed altered expression of lymphangiogenic factors and inflammatory cytokines such as VEGF-A/-C/-D and TNF-α. These findings indicated that simvastatin may modify lymphangiogenesis and tumor progression in malignant melanoma.


Assuntos
Linfangiogênese/efeitos dos fármacos , Metástase Linfática/patologia , Melanoma Experimental/patologia , Sinvastatina/farmacologia , Neoplasias Cutâneas/patologia , Animais , Camundongos , Camundongos Endogâmicos C57BL
19.
Drug Discov Today ; 23(8): 1556-1563, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29879476

RESUMO

Overcoming multidrug resistance (MDR) of cancer cells can be accomplished using drug delivery systems in large-molecular-weight ATP-binding cassette transporters before entry into phagolysosomes and by particle-cell-surface interactions. However, these hypotheses do not address the intratumoral heterogeneity in cancer. Anti-MDR must be related to alterations of drug targets, expression of detoxification, as well as altered proliferation. In this study, it is shown that the excellent efficacy and sustainability of anti-MDR is due to a stable ES complex because of the allosteric facilities of artificial enzymes when they are used as supermolecular complexes. The allosteric effect of supermolecular drugs can be explained by the induced-fit model and can provide stable feedback control systems through the loop transfer function of the Hill equation.


Assuntos
Antineoplásicos/administração & dosagem , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Melanoma Experimental/tratamento farmacológico , Paclitaxel/administração & dosagem , Transportadores de Cassetes de Ligação de ATP/metabolismo , Regulação Alostérica , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Dextranos/química , Portadores de Fármacos , Composição de Medicamentos , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Metilmetacrilatos/química , Camundongos , Modelos Biológicos , Estrutura Molecular , Paclitaxel/química , Paclitaxel/metabolismo , Relação Estrutura-Atividade , Microambiente Tumoral
20.
Sci Rep ; 8(1): 8286, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29844487

RESUMO

Here, we report the application of a portable sequencer, MinION, for genotyping the malaria parasite Plasmodium falciparum. In the present study, an amplicon mixture of nine representative genes causing resistance to anti-malaria drugs is diagnosed. First, we developed the procedure for four laboratory strains (3D7, Dd2, 7G8, and K1), and then applied the developed procedure to ten clinical samples. We sequenced and re-sequenced the samples using the obsolete flow cell R7.3 and the most recent flow cell R9.4. Although the average base-call accuracy of the MinION sequencer was 74.3%, performing >50 reads at a given position improves the accuracy of the SNP call, yielding a precision and recall rate of 0.92 and 0.8, respectively, with flow cell R7.3. These numbers increased significantly with flow cell R9.4, in which the precision and recall are 1 and 0.97, respectively. Based on the SNP information, the drug resistance status in ten clinical samples was inferred. We also analyzed K13 gene mutations from 54 additional clinical samples as a proof of concept. We found that a novel amino-acid changing variation is dominant in this area. In addition, we performed a small population-based analysis using 3 and 5 cases (K13) and 10 and 5 cases (PfCRT) from Thailand and Vietnam, respectively. We identified distinct genotypes from the respective regions. This approach will change the standard methodology for the sequencing diagnosis of malaria parasites, especially in developing countries.


Assuntos
Resistência a Medicamentos/genética , Plasmodium falciparum/genética , Análise de Sequência de DNA/métodos , Animais , Antimaláricos/farmacologia , Genótipo , Humanos , Malária Falciparum/parasitologia , Mutação/efeitos dos fármacos , Nanoporos , Parasitos/genética , Plasmodium falciparum/efeitos dos fármacos , Análise de Sequência de DNA/instrumentação , Tailândia , Vietnã
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