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1.
iScience ; 25(8): 104821, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35982787

RESUMO

In mammals, LGP2 is the enigmatic RLR family member, being initially believed as an inhibitor of RLR-triggered IFN response but subsequently as an activator of MDA5 signaling and an inhibitor of RIG-I signaling. The contradiction happens to fish LGP2. Here, we generate a lgp2 loss-of-function (lgp2 lof/lof ) zebrafish mutant, which is highly susceptible to SVCV infection, displaying an initially decreased activation of IFN response and a following increased one. Mechanistically, zebrafish LGP2 functions as the essential activator of IFN response dependent on MDA5 at the early stage of viral infection but as a negative regulator by impairing mRNA levels of tbk1 and ikki at the late stage of viral infection. The function switch of LGP2 is related to cellular IFN production during viral infection. Our data demonstrate that zebrafish LGP2 is a key homeostatic regulator of IFN response and thus essential for zebrafish survival against SVCV infection.

2.
Zhen Ci Yan Jiu ; 46(6): 486-91, 2021 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-34190452

RESUMO

As the living standard improves and population aging continues, the traditional cupping manipulations fail to meet the ever-growing demand for high-quality medical and health services. Aiming to address such shortcomings of traditional cupping manipulations as difficulty in achieving real-time temperature control, unsatisfactory negative pressure effect and inconve-nience to observe the internal situation, we have developed a glass cupping device with closed-loop control that could automatically integrate the acupoint-symptom analysis models. This device, composed of two cups, boasts high safety, good sealing and sound economic efficiency. The PT100 thermocouple probe and the pressure sensor equipped with P89C668 single chip microcomputer enable the multimodal integration of temperature and pressure, whose main parameters can be automatically displayed on the LED screen by the built-in data processing device. This glass cupping device with closed-loop control is an updated design for acupuncture and moxibustion based on multidisciplinary resources.


Assuntos
Terapia por Acupuntura , Moxibustão , Pontos de Acupuntura
3.
Math Biosci Eng ; 17(5): 5341-5368, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-33120556

RESUMO

In this paper, we establish a stochastic delayed avian influenza model with saturated incidence rate. Firstly, we prove the existence and uniqueness of the global positive solution with any positive initial value. Then, we study the asymptotic behaviors of the disease-free equilibrium and the endemic equilibrium by constructing some suitable Lyapunov functions and applying the Young's inequality and Hölder's inequality. If $\mathscr{R}_0 < 1$, then the solution of stochastic system is going around disease-free equilibrium while the solution of stochastic system is going around endemic equilibrium as $\mathscr{R}_0 >1$. Finally, some numerical examples are carried out to illustrate the accuracy of the theoretical results.


Assuntos
Influenza Aviária , Animais , Incidência , Influenza Aviária/epidemiologia
4.
Math Biosci Eng ; 17(3): 2650-2675, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32233559

RESUMO

Numerical approximation is a vital method to investigate the properties of stochastic age-dependent population systems, since most stochastic age-dependent population systems cannot be solved explicitly. In this paper, a Taylor approximation scheme for a class of age-dependent stochastic delay population equations with mean-reverting Ornstein-Uhlenbeck (OU) process and Poisson jumps is presented. In case that the coefficients of drift and diffusion are Taylor approximations, we prove that the numerical solutions converge to the exact solutions for these equations. Moreover, the convergence order of the numerical scheme is given. Finally, some numerical simulations are discussed to illustrate the theoretical results.


Assuntos
Processos Estocásticos , Difusão
5.
Microbiol Immunol ; 64(1): 23-32, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31595527

RESUMO

Increasing evidence has confirmed that the antimicrobial and anti-inflammatory effects of cinnamon essential oil (CEO) contribute to protection against inflammatory bowel disease (IBD). The dextran sodium sulfate (DSS)-induced colitis mouse model was established to investigate the correlation between the protective effects of CEO and the regulation of intestinal microflora. The symptoms of IBD were assessed by measuring the hemoglobin content, myeloperoxidase activity, histopathological observation, cytokines, and toll-like receptor (TLR4) expression. The alteration of the fecal microbiome composition was analyzed by 16S rRNA gene sequencing. The results indicated that the oral administration of CEO enriched with cinnamaldehyde effectively alleviated the development of DSS-induced colitis. In contrast to the inability of antibiotics to regulate flora imbalance, the mice fed with CEO had an improved diversity and richness of intestinal microbiota, and a modified community composition with a decrease in Helicobacter and Bacteroides and an increase in Bacteroidales_S24-7 family and short-chain fatty acids (SCFA)-producing bacteria (Alloprevotella and Lachnospiraceae_NK4A136_group). Moreover, the correlation analysis showed that TLR4 and tumor necrosis factor-α was positively correlated with Helicobacter, but inversely correlated with SCFA-producing bacteria. These findings indicated from a new perspective that the inhibitory effect of CEO on IBD was closely related to improving the intestinal flora imbalance.


Assuntos
Cinnamomum zeylanicum/química , Colite/tratamento farmacológico , Colite/microbiologia , Sulfato de Dextrana/efeitos adversos , Microbioma Gastrointestinal/efeitos dos fármacos , Óleos Voláteis/farmacologia , Sulfatos/efeitos adversos , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bacteroides/efeitos dos fármacos , Colite/induzido quimicamente , Colite/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Helicobacter/efeitos dos fármacos , Hemoglobinas , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Peroxidase , RNA Ribossômico 16S/genética , Receptor 4 Toll-Like/metabolismo
6.
Math Biosci Eng ; 16(5): 4107-4121, 2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-31499653

RESUMO

This paper focuses on numerical approximation of the basic reproduction number R0, which is the threshold defined by the spectral radius of the next-generation operator in epidemiology. Generally speaking, R0 cannot be explicitly calculated for most age-structured epidemic systems. In this paper, for a deterministic age-structured epidemic system and its stochastic version, we discretize a linear operator produced by the infective population with a theta scheme in a finite horizon, which transforms the abstract problem into the problem of solving the positive dominant eigenvalue of the next-generation matrix. This leads to a corresponding threshold R0,n . Using the spectral approximation theory, we obtain that R0,n → R0 as n → +∞. Some numerical simulations are provided to certify the theoretical results.


Assuntos
Número Básico de Reprodução/estatística & dados numéricos , Epidemias/estatística & dados numéricos , Modelos Biológicos , Fatores Etários , Doenças Transmissíveis/epidemiologia , Simulação por Computador , Humanos , Conceitos Matemáticos , Processos Estocásticos
7.
Microbiol Immunol ; 63(8): 303-315, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31218724

RESUMO

We investigated the correlation between the beneficial effect of Lactobacillus acidophilus on gut microbiota composition, metabolic activities, and reducing cow's milk protein allergy. Mice sensitized with ß-lactoglobulin (ß-Lg) were treated with different doses of L. acidophilus KLDS 1.0738 for 4 weeks, starting 1 week before allergen induction. The results showed that intake of L. acidophilus significantly suppressed the hypersensitivity responses, together with increased fecal microbiota diversity and short-chain fatty acids (SCFAs) concentration (including propionate, butyrate, isobutyrate, and isovalerate) when compared with the allergic group. Moreover, treatment with L. acidophilus induced the expression of SCFAs receptors, G-protein-coupled receptors 41 (GPR41) and 43 (GPR43), in the spleen and colon of the allergic mice. Further analysis revealed that the GPR41 and GPR43 messenger RNA expression both positively correlated with the serum concentrations of transforming growth factor-ß and IFN-γ (p < .05), but negatively with the serum concentrations of IL-17, IL-4, and IL-6 in the L. acidophilus-treated group compared with the allergic group (p < .05). These results suggested that L. acidophilus protected against the development of allergic inflammation by improving the intestinal flora, as well as upregulating SCFAs and their receptors GPR41/43.


Assuntos
Ácidos Graxos Voláteis/metabolismo , Intestinos/microbiologia , Lactobacillus acidophilus/fisiologia , Lactoglobulinas/efeitos adversos , Receptores Acoplados a Proteínas G/metabolismo , Animais , Butiratos/metabolismo , Colo/metabolismo , Modelos Animais de Doenças , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/fisiologia , Hemiterpenos , Interferon gama/metabolismo , Interleucina-17/sangue , Interleucina-4/sangue , Interleucina-6/sangue , Isobutiratos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Hipersensibilidade a Leite/terapia , Proteínas do Leite , Ácidos Pentanoicos/metabolismo , Propionatos/metabolismo , RNA Mensageiro/metabolismo , Baço/metabolismo , Fator de Crescimento Transformador beta/metabolismo
8.
Math Biosci Eng ; 16(4): 2562-2586, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-31137228

RESUMO

In this paper, we analyze the effect of environment noise on the transmission dynamics of a stochastic hepatitis B virus (HBV) infection model with intervention strategies. By using the Markov semigroups theory, we define the stochastic basic reproduction number and find it can be used to govern disease extinction or persistence. When it is less than one, under a mild extra condition, the stochastic system has a disease-free equilibrium and the disease is predicted to die out with probability one. When it is greater than one, under mild extra conditions, the model admits a stationary distribution which means the persistence of the disease. Thus, we observe that larger intensity of noise (resulting in a smaller stochastic basic reproduction number) can suppress the emergence of hepatitis B outbreak. Numerical simulations are also carried out to investigate the influence of information intervention strategies that may change individual behavior and protect the susceptible from infection. Our analysis shows that the environmental noise can greatly a ect the long-term behavior of the system, highlighting the importance of the role of intervention strategies in the control of hepatitis B.


Assuntos
Número Básico de Reprodução , Vírus da Hepatite B , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Processos Estocásticos , Algoritmos , Simulação por Computador , Surtos de Doenças , Saúde Global , Humanos , Infectologia/métodos , Cadeias de Markov , Modelos Biológicos , Probabilidade
9.
Math Biosci Eng ; 16(3): 1348-1375, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30947424

RESUMO

As it is known that environmental perturbation is a key component of epidemic models, and Markov process reveals how the noise affects epidemic systems. The paper introduces Markov chain into a stochastic susceptible-infected-vaccination(SIV) epidemic model composed of vaccination and saturated treatment to analyze the near-optimal control. Based on Pontryagin stochastic maximum principle, the paper gives adequate and all necessary conditions for near-optimal control. Numerical simulations are presented to display the theoretical results and verify the effect of treatment control on epidemic diseases.


Assuntos
Controle de Doenças Transmissíveis/métodos , Síndrome de Imunodeficiência Adquirida dos Símios/epidemiologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia , Algoritmos , Animais , Simulação por Computador , Epidemias , Cadeias de Markov , Modelos Biológicos , Processos Estocásticos , Vacinação
10.
Fish Shellfish Immunol ; 86: 1058-1063, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30593899

RESUMO

In mammals, virus infection of host cells triggers innate immune response, characterized by induction of interferon (IFN) and downstream IFN-stimulated genes (ISGs). The initiation of IFN antiviral response is dependent on host recognition of virus infection. In fish, similar IFN antiviral response is induced in response to RNA or DNA virus infection; however, the detailed mechanisms underlying recognition of a given virus and activation of downstream signaling remain largely unexplored. Using an infection model with Epithelioma papulosum cyprini (EPC) cells and spring viremia of carp virus (SVCV), a negative sense single-stranded RNA virus, we reported that fish RLR signaling pathway was involved in SVCV-triggered fish IFN response. IFN response was significantly initiated in EPC cells when infected with SVCV, as evidenced by activation of fish IFN promoters, upregulation of IFN and ISGs at mRNA and protein levels. However, function blockade of RIG-I and MDA5, two cytosolic receptors of fish RLR family, significantly attenuated the activation of fish IFN promoters and also the induction of fish IFN and ISGs by SVCV infection. Consistently, SVCV infection-triggered IFN response were blocked in EPC cells when transfected with the dominant negative mutants of pivotal RLR signaling factors, including MAVS, MITA, TBK1, IRF3 and IRF7. These results together shed light on the conservation of RLR-mediated IFN signaling that contributes to fish cells responding to RNA virus infection.


Assuntos
Doenças dos Peixes/imunologia , Infecções por Rhabdoviridae/veterinária , Rhabdoviridae/fisiologia , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Cyprinidae/imunologia , Proteína DEAD-box 58/metabolismo , Doenças dos Peixes/virologia , Imunidade Inata , Interferons/imunologia , Regiões Promotoras Genéticas , Infecções por Rhabdoviridae/imunologia
11.
Biosci Biotechnol Biochem ; 82(11): 1955-1963, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30156972

RESUMO

This study aims to investigate the correlation between the ability of L. acidophilus to modulate miRNA expression and prevent Th17-dominated ß-lactoglobulin (ß-Lg) allergy. In vitro immunomodulation was evaluated by measuring splenocyte proliferation, Th17-related immune response and miRNA expression in ß-Lg-sensitized splenocytes cultured with live L. acidophilus. Next, the allergic mouse model was used to evaluate anti-allergy capability of lactobacilli. The ß-Lg challenge led to induction of up-regulation of miR-146a, miR-155, miR-21 and miR-9 expression in both in vivo and in vitro, along with increased Th17-related cytokine levels and mRNA expression of RORγt and IL-17. However, treatment of live L. acidophilus significantly suppressed hypersensitivity responses and Th17 cell differentiation. Moreover, administration of live L. acidophilus reduced expression of four miRNAs, especially miR-146a and miR-155. In addition, the decreased expression of the miRNAs in the spleen of the L. acidophilus-treated group was closely associated with decrease of IL-17 and RORγt mRNA expression.


Assuntos
Lactobacillus acidophilus , Lactoglobulinas/efeitos adversos , MicroRNAs/genética , Hipersensibilidade a Leite/etiologia , Hipersensibilidade a Leite/prevenção & controle , Animais , Bovinos , Polaridade Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Técnicas In Vitro , Lactoglobulinas/administração & dosagem , Camundongos Endogâmicos BALB C , Hipersensibilidade a Leite/genética , Hipersensibilidade a Leite/imunologia , Reação em Cadeia da Polimerase em Tempo Real , Células Th17/citologia , Células Th17/imunologia
12.
Cell Physiol Biochem ; 46(5): 1861-1867, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29705808

RESUMO

BACKGROUND/AIMS: SUMOylation is a dynamic process and reversed by the activity of SUMO-specific proteases (SENPs) family. SENP1, a member of this family, is highly expressed and plays oncogenic roles in diverse cancers including prostate cancer. However, the SENP1-transgenic mice exhibit aberrant transformation of the mouse prostate gland but do not develop cancer. Cellular Stress Response 1 (CSR1) is a tumor suppressor gene and frequently deleted in prostate cancers. Overexpression of CSR1 in prostate cancer cells inhibits colony formation, anchorage-independent growth and induces cell death. METHODS: The relationship between CSR1 and SENP1 were determined by immunoprecipitation-based proteomics screen and verified by GST-pull down assay. In vivo SUMOylation assay was used to detect the direct effect of SENP1 in the regulation of CSR1. Clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing was used to generate Senp1-/- and CSR1-/- PC3 cells. FACS assay was used to determine the apoptosis ratio of cells after transfection. RESULTS: CSR1 is SUMOylated at K582 and rapid ubiquitinated and degradated in prostate cancer cells. SENP1 interacts with and deSUMOylates CSR1 to prevent its degradation and enhances CSR1-dependent prostate cancer cell death. CONCLUSION: Thus, our data indicates that CSR1 is a critical SUMOylated substrate of SENP1 that might partially explain the controversial roles of SENP1 in prostate cancer development.


Assuntos
Proteínas de Choque Térmico/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Depuradores Classe A/metabolismo , Sumoilação , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Cisteína Endopeptidases/metabolismo , Humanos , Masculino , Neoplasias da Próstata/patologia , Estabilidade Proteica , Ubiquitinação
13.
J Immunol ; 200(2): 688-703, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29203516

RESUMO

In mammals, RIG-I like receptors (RLRs) RIG-I and melanoma differentiation-associated gene 5 (MDA5) sense cytosolic viral RNA, leading to IFN antiviral response; however, LGP2 exhibits controversial functions. The same happens to fish LGP2. In this study we report that three zebrafish LGP2 splicing transcripts, a full-length LGP2, and two truncating variants, LGP2v1 and LGP2v2, play distinct roles during IFN antiviral response. Overexpression of the full-length LGP2 not only potentiates IFN response through the RLR pathway, in the absence or presence of poly(I:C) at limited concentrations, but also inhibits IFN response by relative high concentrations of poly(I:C) through functional attenuation of signaling factors involved in the RLR pathway; however, LGP2v1 and LGP2v2 only retain the inhibitory role. Consistently, LGP2 but not LGP2v1 and LGP2v2 confers protection on fish cells against spring viremia of carp virus (SVCV) infection and at limited expression levels, LGP2 exerts more significant protection than either RIG-I or MDA5. Further data suggest that in the early phase of SVCV infection, LGP2 functions as a positive regulator but along with SVCV replicating in cells up to a certain titer, which leads to a far more robust expression of IFN, LGP2 switches to a negative role. These in vitro results suggest an ingenious mechanism where the three zebrafish LGP2 splicing transcripts work cooperatively to shape IFN antiviral responses.


Assuntos
Processamento Alternativo , Antivirais/metabolismo , Resistência à Doença/genética , Proteínas de Peixes/genética , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Interferons/biossíntese , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Resistência à Doença/imunologia , Doenças dos Peixes/genética , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Interações Hospedeiro-Patógeno/imunologia , Poli I-C/imunologia , Polilisina/imunologia , RNA Helicases/genética , RNA Helicases/metabolismo , Transdução de Sinais , Replicação Viral/imunologia , Peixe-Zebra/virologia
14.
J Immunol ; 197(5): 1893-904, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27496972

RESUMO

In mammals, IFN regulatory factor (IRF)1, IRF3, and IRF7 are three critical transcription factors that are pivotal for cooperative regulation of the type I IFN response. In this study, we explored the relative contribution of zebrafish (Danio rerio) IRF1 (DrIRF1), IRF3 (DrIRF3), and IRF7 (DrIRF7) (DrIRF1/3/7) to zebrafish IFNΦ1 (DrIFNΦ1) and IFNΦ3 (DrIFNΦ3) (DrIFNΦ1/3) activation. Following spring viremia of carp virus infection, DrIFNΦ1/3 and DrIRF1/3/7 transcripts are significantly induced in zebrafish tissues, which correlates with the replication of spring viremia of carp virus. DrIRF1/3/7 selectively bind to the IRF-binding element/IFN-stimulated regulatory element sites of DrIFNΦ1/3 promoters, with the exception that DrIRF3 has no preference for two IRF-binding element/IFN-stimulated regulatory element motifs within the DrIFNΦ3 promoter. Consistently, DrIRF3 alone activates DrIFNΦ1, but not DrIFNΦ3; DrIRF7 predominantly stimulates DrIFNΦ3; and DrIRF1 has similar potential to DrIFNΦ1 and DrIFNΦ3. Strikingly, DrIRF3 facilitates the binding of DrIRF1 and DrIRF7 to both zebrafish IFN promoters, and so does DrIRF7 for the binding of DrIRF1, particularly to the DrIFNΦ3 promoter. These binding properties correlate with differential responses of DrIFNΦ1 and DrIFNΦ3 to the combinatory stimulation of DrIRF1/3/7, depending on their relative amounts. Similar to the dual roles of human IRF3 in regulating IRF7-activated IFNα genes, DrIRF3 exerts dual effects on DrIRF1-mediated DrIFNΦ3 gene expression: an inhibitory effect at lower concentrations and a synergistic effect at higher concentrations. These data provide evidence that fish and mammals have evolved a similar IRF-dependent regulatory mechanism fine-tuning IFN gene activation.


Assuntos
Regulação da Expressão Gênica , Fator Regulador 1 de Interferon/genética , Fator Regulador 3 de Interferon/genética , Fator Regulador 7 de Interferon/genética , Interferons/genética , Infecções por Rhabdoviridae/imunologia , Animais , Sítios de Ligação , Fator Regulador 1 de Interferon/imunologia , Fator Regulador 3 de Interferon/imunologia , Fator Regulador 7 de Interferon/imunologia , Interferons/imunologia , Regiões Promotoras Genéticas , Ligação Proteica , Rhabdoviridae , Infecções por Rhabdoviridae/metabolismo , Transdução de Sinais , Transcrição Gênica , Ativação Transcricional , Peixe-Zebra/genética , Peixe-Zebra/imunologia
15.
Zhonghua Nan Ke Xue ; 21(7): 630-3, 2015 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-26333226

RESUMO

OBJECTIVE: To evaluate the effect of meatoplasty with the pedicle flap in the treatment of meatal stenosis secondary to chronic balanitis. METHODS: We retrospectively analyzed 32 cases of meatal stenosis secondary to chronic balanitis treated by meato- plasty with the pedicle flap. All the patients had a history of chronic balanitis and had received meatal dilatation or simple ventral mea- totomy without significant effect. Their mean maximum urinary flow rate (Qmax) was (4.3 ± 2.4) ml/s. During the operation, A "/\"-shaped incision was made in the healthy epidermis and a flap was harvested from the frenulum. After complete removal of the scar, the flap was placed into the urethral wall, followed by reconstruction of the external urethral orifice. RESULTS: The patients were fol- lowed up for 6 to 30 months, which revealed smooth urination in all the patients with Qmax of (26.7 ± 4.5) ml/s and normal erectile function and uresiesthesis. CONCLUSION: With little invasiveness and few complications, meatoplasty with the pedicle flap is an ideal surgical method for the treatment of meatal stenosis secondary to chronic balanitis. However, there might be some change in the normal appearance of the balanus postoperatively, and its long-term effect needs further observation.


Assuntos
Balanite (Inflamação)/complicações , Constrição Patológica/cirurgia , Uretra/cirurgia , Estreitamento Uretral/cirurgia , Constrição Patológica/etiologia , Dilatação , Humanos , Masculino , Período Pós-Operatório , Procedimentos de Cirurgia Plástica , Estudos Retrospectivos , Retalhos Cirúrgicos , Estreitamento Uretral/etiologia , Micção
16.
J Immunol ; 194(3): 1225-38, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25535281

RESUMO

In mammals, type I IFNs (mainly IFN-α/ß) are primarily regulated by transcription factors of the IFN regulatory factor (IRF) family. Fish IFNs do not show a one-to-one orthologous relationship with mammalian type I IFN homologues. Using a bacterial one-hybrid reporter screening system and an overexpression approach to explore the molecular mechanism underlying fish IFN induction, we identified zebrafish Danio rerio IRF (DrIRF)1 as a positive regulator of the fish IFN antiviral response. Among 12 zebrafish IRF family genes, DrIRF1 is most abundant in zebrafish immune tissues, including head kidney and spleen; upon virus infection, it is one of most significantly induced genes. Overexpression of DrIRF1 induces the expression of IFN and IFN-stimulated genes, hence protecting epithelioma papulosum cyprini cells against spring viremia of carp virus infection. As a transcription factor with constitutively nuclear retention, DrIRF1 directly binds to the IFN-stimulated regulatory element/IRF-binding element sites of zebrafish IFN promoters, which are dependent on four conserved amino acids of the N-terminal DNA-binding domain helix α3 motif. Mutation of either residue reveals a differential requirement for DrIRF1-mediated activation of zebrafish IFNϕ1 and IFNϕ3 promoters. Notably, C-terminal phosphorylation of DrIRF1 is observed and is not required for in vitro binding of DrIRF1 to fish IFN promoters. Unlike DrIRF3 and DrIRF7, which are responsible for differential expression of zebrafish IFNϕ1 and IFNϕ3 through the retinoic acid-inducible gene I-like receptor pathway, DrIRF1 works in concert with MyD88 to activate zebrafish IFNϕ3 but not IFNϕ1. These results provide insights into the evolving function of IRF1 as a positive IFN regulator.


Assuntos
Regulação da Expressão Gênica , Fator Regulador 1 de Interferon/metabolismo , Interferons/genética , Interferons/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Regiões Promotoras Genéticas , Transdução de Sinais , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Núcleo Celular/metabolismo , Células Cultivadas , Análise por Conglomerados , Perfilação da Expressão Gênica , Ordem dos Genes , Fator Regulador 1 de Interferon/química , Fator Regulador 1 de Interferon/genética , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico , Alinhamento de Sequência , Fatores de Transcrição/metabolismo , Viroses/genética , Viroses/imunologia , Viroses/metabolismo , Peixe-Zebra
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