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1.
Reprod Sci ; 30(2): 473-486, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36085549

RESUMO

This study examined the protective effects of small peptides from Periplaneta americana against H2O2-induced mitochondrial injury in human ovarian granulosa cells. The ATP level and mitochondrial membrane potential as well as the quantity and ultrastructure of mitochondria in cells were detected. Mitochondrial DNA copy number and expression levels of Bcl2L13, LC3B, and p62 were tested. Targeted silencing of Bcl2L13 expression in KGN cells. The expression levels of Bcl2L13 and LC3B as well as interaction were evaluated. The ATP level, mtDNA-CN, and MMP of the H2O2 group were significantly lower than those of the normal control group (P < 0.05), accompanied by a reduction in mitochondrial mass and mitochondrial fluorescence intensity (P < 0.05). However, the ATP level, mtDNA, and MMP in KGN cells were increased after SPPA treatment (P < 0.05). Scanning electron microscopy shows that SPPA ameliorates H2O2-induced structural damage to mitochondria. Moreover, the expression levels of Bcl2L13 and p62 in the H2O2 group were downregulated significantly compared with those of the normal control group (P < 0.05), while LC3B was upregulated (P < 0.05). After SPPA treatment, the expression levels of Bcl2L13 and p62 were upregulated (P < 0.05), while LC3B was downregulated (P < 0.05). The Co-IP results indicated that Bcl2L13 and LC3B interacted, and this interaction was weakened after cell treatment with H2O2, and dissociation between Bcl2L13 and LC3B declined after SPPA treatment. SPPA inhibits KGN cell apoptosis induced by oxidative stress via inhibition of mitochondrial injury Bcl2L13-mediated mitochondrial autophagy might participate in the regulation process.


Assuntos
Periplaneta , Animais , Feminino , Humanos , Trifosfato de Adenosina/metabolismo , Apoptose , DNA Mitocondrial/metabolismo , Peróxido de Hidrogênio/toxicidade , Mitocôndrias/metabolismo , Estresse Oxidativo , Peptídeos/metabolismo , Periplaneta/metabolismo
2.
J Obstet Gynaecol Res ; 48(1): 188-199, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34729871

RESUMO

AIM: To investigate the protective effect of small peptides from Periplaneta americana (SPPA) on cyclophosphamide (CP)-induced premature ovarian failure (POF) in mice. Silent mating type information regulation 2 homolog 1 (SIRT1) /tumor-associated protein 53 (p53) signaling pathway plays an important role in delaying POF. Hematopoietic progenitor cell antigen (CD34) reflects ovarian aging from the side. However, whether SPPA inhibits POF in mice by influencing the SIRT1/p53 pathway and CD34 expression remains to be studied. METHODS: Forty female Kun Ming (KM) mice were divided into four groups: a control group (normal saline, n = 10), POF model group (160 mg/kg CP, n = 10), SPPA low-dosage group (160 mg/kg CP + 100 mg/kg SPPA, n = 10), and SPPA high-dosage group (160 mg/kg CP + 200 mg/kg SPPA, n = 10). CP administration route is intraperitoneal injection, and SPPA administration route is intragastric. Eyeball enucleation blood samples and the ovaries of mice were collected by midline laparatomy and oopherectomy, and the malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH) concentrations were tested. Immunohistochemical tests for the expressions of SIRT1, p53, and CD34 were carried out. Finally, ovarian mRNA levels of SIRT1 and p53 were detected with real-time fluorescence quantification PCR (qRT-PCR). RESULTS: A mouse model of POF was generated using 160 mg/kg of CP. Compared with POF group, we found that plasma NO, MDA, and FSH decreased, while AMH and SOD increased in the SPPA low-dose group. Compared with the POF group, the SPPA low- and high-dosage groups achieved significant growth in the number of primordial, primary, and total number of healthy follicles at all levels, but sharp reductions in the number of atretic follicles. In addition, we found downregulated protein and mRNA expression of SIRT1, and upregulated that of p53 were observed in ovarian tissues of treated mice with POF, in immunohistochemistry experiments and qPCR experiments. In contrast, high protein and mRNA expression of SIRT1, and low that of p53 were observed in SPPA treatment groups. And the results of CD34 protein expression were consistent with that of SIRT1. CONCLUSION: In total, SPPA significantly inhibited POF caused by CP in mice via activation of the SIRT1/p53 signaling pathway in the mouse ovary.


Assuntos
Menopausa Precoce , Periplaneta , Insuficiência Ovariana Primária , Animais , Ciclofosfamida , Feminino , Camundongos , Peptídeos , Insuficiência Ovariana Primária/induzido quimicamente , Insuficiência Ovariana Primária/prevenção & controle
3.
J Anim Physiol Anim Nutr (Berl) ; 106(3): 528-536, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34486782

RESUMO

Betaine, the trimethyl derivative of glycine, is a good methyl group donor, and an important component in pig production. However, betaine has not been extensively studied in this field. Therefore, in this study, we reviewed the effects of betaine in pig production performance, meat quality and reproductive performance, as well as its mechanisms, to provide a theoretical basis for the optimal use and development of this compound.


Assuntos
Betaína , Carne , Animais , Betaína/farmacologia , Glicina , Carne/análise , Suínos
4.
Reprod Domest Anim ; 56(11): 1413-1424, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34390025

RESUMO

Oxidative stress can induce apoptosis of granulosa cells and lead to follicular atresia, thereby reducing the number of pigs giving birth. The aim of this study was to investigate the protective effect of Periplaneta americana peptide (PAP) on the apoptosis of the granulosa cells of pig ovaries (PGCs) induced by hydrogen peroxide (H2 O2 ) via FoxO1. PGCs were treated with H2 O2 to establish a cell apoptosis model. Cell viability was measured using the cell counting kit-8 (CCK-8) assay, and cell apoptosis was detected using flow cytometry. The malondialdehyde (MDA) level and nitric oxide (NO) content were detected to reflect the oxidative stress. Western blotting, qRT-PCR and overexpression were undertaken to determine the expression of FoxO1 and caspase-3, and immunofluorescence was used to detect FoxO1 in the nucleus and cytoplasm. PGCs were treated with 100 µM H2 O2 for 6 hr, which resulted in oxidative damage and apoptosis and an apoptosis rate for PGCs of 32.95%. Next, PGCs were treated with 400 µg/ml PAP for 24 hr to repair the apoptosis induced by H2 O2 . PAP improved cell viability in H2 O2 -stimulated PGCs, the increased MDA level and NO content caused by H2 O2 stimulation were reversed and the apoptotic rate of PGCs was reduced. The qRT-PCR and Western blotting results indicated that PAP decreased the H2 O2 -induced apoptosis and the expression of FoxO1 and caspase-3 in PGCs. The effect of PAP was the same following FoxO1 overexpression. FoxO1 was expressed in the nucleus when stimulated by H2 O2 or overexpression; however, it migrated to the cytoplasm following PAP treatment. PAP decreased the apoptosis of PGCs induced by H2 O2 by regulating FoxO1 expression and nuclear translocation.


Assuntos
Apoptose/efeitos dos fármacos , Proteína Forkhead Box O1/metabolismo , Células da Granulosa/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Células Cultivadas , Feminino , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Periplaneta/química , Suínos
5.
In Vitro Cell Dev Biol Anim ; 57(6): 610-619, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34155600

RESUMO

This study investigates the protective effect of small peptides from Periplaneta americana (SPPA) on hydrogen peroxide (H2O2)-induced apoptosis of ovarian granular cells. H2O2 was applied to human ovarian granular cells (KGN cell strains). Cell viability was tested by cell counting Kit-8 (CCK-8). Cell apoptosis was tested by flow cytometry, and a cell apoptosis model was established. The model cells were treated with SPPA, and the cell survival rate was monitored using the CCK-8 method. The oxidative stress state of cells was examined using SOD, ROS, MDA, and NO kits. The protein expression levels of SIRT1, p53, and the apoptosis-related gene Caspase3 were measured using Western Blot methodology. Relative to the control group, cell viability declined significantly after the H2O2 treatment only (P < 0.01), while the apoptosis rate increased significantly (P < 0.01). The activity of SOD was weakened significantly (P < 0.01), while the cell levels of ROS, MDA, and NO increased dramatically (P < 0.01). Cell viability dramatically recovered (P < 0.01), and the SOD activity is hugely increased (P < 0.01) after SPPA treatment. In contrast, contents of ROS, MDA, and NO decreased sharply (P < 0.01), and significant dose-response relationships are characterized. Moreover, the H2O2 treatment group showed significantly downregulated expression of SIRT1 (P < 0.01) but significantly upregulated expressions of p53 and Caspase3 (P < 0.01) compared to the control group. Following the SPPA treatment of apoptosis cells, expression of SIRT1 increased significantly, while expressions of p53 and Caspase3 declined significantly (P < 0.01). This study suggests that SPPA inhibits H2O2-induced human KGN cell apoptosis through antioxidation, and the SIRT1/p53 signal pathway mediates the antioxidation.


Assuntos
Antioxidantes/farmacologia , Caspase 3/genética , Peptídeos/farmacologia , Sirtuína 1/genética , Proteína Supressora de Tumor p53/genética , Animais , Antioxidantes/química , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/toxicidade , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/crescimento & desenvolvimento , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/química , Periplaneta/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/genética , Superóxido Dismutase/efeitos dos fármacos
6.
Am J Trop Med Hyg ; 98(2): 420-431, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29231157

RESUMO

Yellow fever (YF) is a viral disease transmitted by mosquitoes and endemic mostly in South America and Africa with 20-50% fatality. All current licensed YF vaccines, including YF-Vax® (Sanofi-Pasteur, Lyon, France) and 17DD-YFV (Bio-Manguinhos, Rio de Janeiro, Brazil), are based on live attenuated virus produced in hens' eggs and have been widely used. The YF vaccines are considered safe and highly effective. However, a recent increase in demand for YF vaccines and reports of rare cases of YF vaccine-associated fatal adverse events have provoked interest in developing a safer YF vaccine that can be easily scaled up to meet this increased global demand. To this point, we have engineered the YF virus envelope protein (YFE) and transiently expressed it in Nicotiana benthamiana as a stand-alone protein (YFE) or as fusion to the bacterial enzyme lichenase (YFE-LicKM). Immunogenicity and challenge studies in mice demonstrated that both YFE and YFE-LicKM elicited virus neutralizing (VN) antibodies and protected over 70% of mice from lethal challenge infection. Furthermore, these two YFE-based vaccine candidates induced VN antibody responses with high serum avidity in nonhuman primates and these VN antibody responses were further enhanced after challenge infection with the 17DD strain of YF virus. These results demonstrate partial protective efficacy in mice of YFE-based subunit vaccines expressed in N. benthamiana. However, their efficacy is inferior to that of the live attenuated 17DD vaccine, indicating that formulation development, such as incorporating a more suitable adjuvant, may be required for product development.


Assuntos
Modelos Animais de Doenças , Vacina contra Febre Amarela/biossíntese , Febre Amarela/prevenção & controle , Animais , ELISPOT/métodos , Humanos , Camundongos/imunologia , Testes de Neutralização/métodos , Febre Amarela/tratamento farmacológico , Vacina contra Febre Amarela/imunologia , Vacina contra Febre Amarela/uso terapêutico , Vírus da Febre Amarela/imunologia
7.
J Am Med Dir Assoc ; 19(1): 12-17, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28757330

RESUMO

OBJECTIVE: To cross-culturally adapt and test the FRAIL scale in Chinese community-dwelling older adults. DESIGN: Cross-sectional study. METHODS: The Chinese FRAIL scale was generated by translation and back-translation. An urban sample of 1235 Chinese community-dwelling older adults was enrolled to test its psychometric properties, including convergent validity, criterion validity, known-group divergent validity, internal consistency and test-retest reliability. RESULTS: The Chinese FRAIL scale achieved semantic, idiomatic, and experiential equivalence. The convergent validity was confirmed by statistically significant kappa coefficients (0.209-0.401, P < .001) of each item with its corresponding alternative measurement, including the 7th item of the Center for Epidemiologic Studies-Depression Scale, the Timed Up and Go test, 4-m walking speed, polypharmacy, and the Short-Form Mini Nutritional Assessment. Using the Fried frailty phenotype as an external criterion, the Chinese FRAIL scale showed satisfactory diagnostic accuracy for frailty (area under the curve = 0.91). The optimal cut-point for frailty was 2 (sensitivity: 86.96%, specificity: 85.64%). The Chinese FRAIL scale had fair agreement with the Fried frailty phenotype (kappa = 0.274, P < .001), and classified more participants into frailty (17.2%) than the Fried frailty phenotype (3.9%). More frail individuals were recognized by the Chinese FRAIL scale among older and female participants than their counterparts (P < .001), respectively. It had low internal consistency (Kuder-Richardson formula 20 = 0.485) and good test-retest reliability within a 7- to 15-day interval (intraclass correlation coefficient = 0.708). CONCLUSIONS: The Chinese FRAIL scale presents acceptable validity and reliability and can apply to Chinese community-dwelling older adults.


Assuntos
Comparação Transcultural , Fragilidade/diagnóstico , Avaliação Geriátrica/métodos , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , China , Estudos Transversais , Feminino , Fragilidade/epidemiologia , Humanos , Vida Independente/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural/fisiologia , Psicometria , Curva ROC , Medição de Risco , Sensibilidade e Especificidade , Fatores Sexuais , Fatores Socioeconômicos
8.
PLoS Pathog ; 8(3): e1002566, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22396649

RESUMO

Aberrant expression of Aurora A kinase has been frequently implicated in many cancers and contributes to chromosome instability and phosphorylation-mediated ubiquitylation and degradation of p53 for tumorigenesis. Previous studies showed that p53 is degraded by Kaposi's sarcoma herpesvirus (KSHV) encoded latency-associated nuclear antigen (LANA) through its SOCS-box (suppressor of cytokine signaling, LANA(SOCS)) motif-mediated recruitment of the EC(5)S ubiquitin complex. Here we demonstrate that Aurora A transcriptional expression is upregulated by LANA and markedly elevated in both Kaposi's sarcoma tissue and human primary cells infected with KSHV. Moreover, reintroduction of Aurora A dramatically enhances the binding affinity of p53 with LANA and LANA(SOCS)-mediated ubiquitylation of p53 which requires phosphorylation on Ser215 and Ser315. Small hairpin RNA or a dominant negative mutant of Aurora A kinase efficiently disrupts LANA-induced p53 ubiquitylation and degradation, and leads to induction of p53 transcriptional and apoptotic activities. These studies provide new insights into the mechanisms by which LANA can upregulate expression of a cellular oncogene and simultaneously destabilize the activities of the p53 tumor suppressor in KSHV-associated human cancers.


Assuntos
Herpesvirus Humano 8/genética , Proteínas Serina-Treonina Quinases/genética , Proteína Supressora de Tumor p53/genética , Antígenos Virais/genética , Antígenos Virais/metabolismo , Aurora Quinases , Linhagem Celular Tumoral , Regulação Viral da Expressão Gênica , Herpesvirus Humano 8/metabolismo , Humanos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Leucócitos Mononucleares/virologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , Transcrição Gênica , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Ubiquitinação , Regulação para Cima
9.
J Virol ; 86(8): 4586-98, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22318147

RESUMO

A herpes simplex virus 2 (HSV-2) glycoprotein E deletion mutant (gE2-del virus) was evaluated as a replication-competent, attenuated live virus vaccine candidate. The gE2-del virus is defective in epithelial cell-to-axon spread and in anterograde transport from the neuron cell body to the axon terminus. In BALB/c and SCID mice, the gE2-del virus caused no death or disease after vaginal, intravascular, or intramuscular inoculation and was 5 orders of magnitude less virulent than wild-type virus when inoculated directly into the brain. No infectious gE2-del virus was recovered from dorsal root ganglia (DRG) after multiple routes of inoculation; however, gE2-del DNA was detected by PCR in lumbosacral DRG at a low copy number in some mice. Importantly, no recurrent vaginal shedding of gE2-del DNA was detected in immunized guinea pigs. Intramuscular immunization outperformed subcutaneous immunization in all parameters evaluated, although individual differences were not significant, and two intramuscular immunizations were more protective than one. Immunized animals had reduced vaginal disease, vaginal titers, DRG infection, recurrent genital lesions, and recurrent vaginal shedding of HSV-2 DNA; however, protection was incomplete. A combined modality immunization using live virus and HSV-2 glycoprotein C and D subunit antigens in guinea pigs did not totally eliminate recurrent lesions or recurrent vaginal shedding of HSV-2 DNA. The gE2-del virus used as an immunotherapeutic vaccine in previously HSV-2-infected guinea pigs greatly reduced the frequency of recurrent genital lesions. Therefore, the gE2-del virus is safe, other than when injected at high titer into the brain, and is efficacious as a prophylactic and immunotherapeutic vaccine.


Assuntos
Deleção de Genes , Vacinas contra o Vírus do Herpes Simples/imunologia , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/imunologia , Neurônios/virologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Chlorocebus aethiops , DNA Viral , Feminino , Gânglios Espinais/virologia , Cobaias , Herpes Genital/mortalidade , Herpes Genital/prevenção & controle , Herpes Genital/terapia , Herpes Simples/mortalidade , Herpes Simples/prevenção & controle , Herpes Simples/terapia , Vacinas contra o Vírus do Herpes Simples/administração & dosagem , Vacinas contra o Vírus do Herpes Simples/efeitos adversos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Medula Espinal/virologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia
10.
Virology ; 405(2): 269-79, 2010 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-20598729

RESUMO

The HSV-2 lifecycle involves virus spread in a circuit from the inoculation site to dorsal root ganglia and return. We evaluated the role of gE-2 in the virus lifecycle by deleting amino acids 124-495 (gE2-del virus). In the mouse retina infection model, gE2-del virus does not spread to nuclei in the brain, indicating a defect in anterograde (pre-synaptic to post-synaptic neurons) and retrograde (post-synaptic to pre-synaptic neurons) spread. Infection of neuronal cells in vitro demonstrates that gE-2 is required for targeting viral proteins from neuron cell bodies into axons, and for efficient virus spread from epithelial cells to axons. The mouse flank model confirms that gE2-del virus is defective in spread from epithelial cells to neurons. Therefore, we defined two steps in the virus lifecycle that involve gE-2, including efficient spread from epithelial cells to axons and targeting viral components from neuron cell bodies into axons.


Assuntos
Axônios/metabolismo , Células Epiteliais/virologia , Herpesvirus Humano 2/patogenicidade , Neurônios/virologia , Proteínas do Envelope Viral/metabolismo , Proteínas Virais/metabolismo , Animais , Células Cultivadas , Chlorocebus aethiops , Modelos Animais de Doenças , Feminino , Herpes Simples/fisiopatologia , Herpes Simples/virologia , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/metabolismo , Humanos , Queratinócitos/virologia , Camundongos , Camundongos Endogâmicos BALB C , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Retina/virologia , Deleção de Sequência , Vagina/virologia , Células Vero , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas Virais/genética
11.
J Virol ; 82(13): 6734-46, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18417561

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) genomes are tethered to the host chromosomes and partitioned faithfully into daughter cells with the host chromosomes. The latency-associated nuclear antigen (LANA) is important for segregation of the newly synthesized viral genomes to the daughter nuclei. Here, we report that the nuclear mitotic apparatus protein (NuMA) and LANA can associate in KSHV-infected cells. In synchronized cells, NuMA and LANA are colocalized in interphase cells and separate during mitosis at the beginning of prophase, reassociating again at the end of telophase and cytokinesis. Silencing of NuMA expression by small interfering RNA and expression of LGN and a dominant-negative of dynactin (P150-CC1), which disrupts the association of NuMA with microtubules, resulted in the loss of KSHV terminal-repeat plasmids containing the major latent origin. Thus, NuMA is required for persistence of the KSHV episomes in daughter cells. This interaction between NuMA and LANA is critical for segregation and maintenance of the KSHV episomes through a temporally controlled mechanism of binding and release during specific phases of mitosis.


Assuntos
Antígenos Nucleares/metabolismo , Antígenos Virais/metabolismo , Segregação de Cromossomos/genética , Genoma Viral/genética , Herpesvirus Humano 8/genética , Proteínas Associadas à Matriz Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Animais , Antígenos Virais/genética , Western Blotting , Proteínas de Ciclo Celular , Linhagem Celular , Primers do DNA/genética , Humanos , Imunoprecipitação , Camundongos , Microscopia de Fluorescência , Microtúbulos/metabolismo , Proteínas Nucleares/genética , Plasmídeos/genética , Interferência de RNA
12.
J Virol ; 81(19): 10413-23, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17634230

RESUMO

Hypoxia-inducible factor 1 (HIF-1) is a ubiquitously expressed transcriptional regulator involved in induction of numerous genes associated with angiogenesis and tumor growth. Kaposi's sarcoma, associated with increased angiogenesis, is a highly vascularized, endothelial cell-derived tumor. Previously, we have shown that the latency-associated nuclear antigen (LANA) encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) targets the HIF-1alpha suppressors von Hippel-Lindau protein and p53 for degradation via its suppressor of cytokine signaling-box motif, which recruits the EC5S ubiquitin complex. Here we further show that HIF-1alpha was aberrantly accumulated in KSHV latently infected primary effusion lymphoma (PEL) cells, as well as HEK293 cells infected with KSHV, and also show that a potential alpha-helical amino-terminal domain of LANA was important for HIF-1alpha nuclear accumulation in normoxic conditions. Moreover, we have now determined that this association was dependent on the residues 46 to 89 of LANA and the oxygen-dependent degradation domain of HIF-1alpha. Introduction of specific small interfering RNA against LANA into PEL cells also resulted in a diminished nuclear accumulation of HIF-1alpha. Therefore, these data show that LANA can function not only as an inhibitor of HIF-1alpha suppressor proteins but can also induce nuclear accumulation of HIF-1alpha during KSHV latent infection.


Assuntos
Antígenos Virais/metabolismo , Herpesvirus Humano 8/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas Nucleares/metabolismo , Sarcoma de Kaposi/metabolismo , Sarcoma de Kaposi/virologia , Motivos de Aminoácidos , Antígenos Virais/química , Antígenos Virais/genética , Linhagem Celular Transformada , Núcleo Celular/química , Núcleo Celular/metabolismo , Herpesvirus Humano 8/genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteínas Nucleares/química , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
13.
J Virol ; 80(22): 11178-90, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16928741

RESUMO

Latency-associated nuclear antigen (LANA) of KSHV is expressed in all forms of Kaposi's sarcoma-associated herpesvirus (KSHV)-mediated tumors and is important for TR-mediated replication and persistence of the virus. LANA does not exhibit any enzymatic activity by itself but is critical for replication and maintenance of the viral genome. To identify LANA binding proteins, we used a LANA binding sequence 1 DNA affinity column and determined the identities of a number of proteins associated with LANA. One of the identified proteins was uracil DNA glycosylase 2 (UNG2). UNG2 is important for removing uracil residues yielded after either misincorporation of dUTP during replication or deamination of cytosine. The specificity of the 'LANA-UNG2 interaction was confirmed by using a scrambled DNA sequence affinity column. Interaction of LANA and UNG2 was further confirmed by in vitro binding and coimmunoprecipitation assays. Colocalization of these proteins was also detected in primary effusion lymphoma (PEL) cells, as well as in a cotransfected KSHV-negative cell line. UNG2 binds to the carboxyl terminus of LANA and retains its enzymatic activity in the complex. However, no major effect on TR-mediated DNA replication was observed when a UNG2-deficient (UNG(-/-)) cell line was used. Infection of UNG(-/-) and wild-type mouse embryonic fibroblasts with KSHV did not reveal any difference; however, UNG(-/-) cells produced a significantly reduced number of virion particles after induction. Interestingly, depletion of UNG2 in PEL cells with short hairpin RNA reduced the number of viral genome copies and produced infection-deficient virus.


Assuntos
Antígenos Virais/metabolismo , DNA Glicosilases/metabolismo , Herpesvirus Humano 8/fisiologia , Proteínas Nucleares/metabolismo , Mapeamento de Interação de Proteínas , Sequências Repetidas Terminais , Latência Viral/fisiologia , Animais , Linhagem Celular , Células Cultivadas , Humanos , Imunoprecipitação , Linfócitos/química , Linfoma/virologia , Camundongos , Modelos Biológicos , Ligação Proteica
14.
J Virol ; 80(18): 9017-30, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16940514

RESUMO

Terminal repeat (TR) elements of Kaposi's sarcoma-associated herpesvirus (KSHV), the potential origin sites of KSHV replication, have been demonstrated to play important roles in viral replication and transcription and are most likely also critical for the segregation of the KSHV genome to daughter cells. To search for the cellular proteins potentially involved in KSHV genome maintenance, we performed affinity chromatography analysis, using KSHV TR DNA as the affinity ligand. Proteomic analysis was then carried out to identify the TR-interacting proteins. We identified a total of 123 proteins from both KSHV-positive and -negative cells, among which most were identified exclusively from KSHV-positive cells. These proteins were categorized as proliferation/cell cycle regulatory proteins, proteins involved in spliceosome components, such as heterogeneous nuclear ribonuclear proteins, the DEAD/H family, the switch/sucrose nonfermenting protein family, splicing factors, RNA binding proteins, transcription regulation proteins, replication factors, modifying enzymes, and a number of proteins that could not be broadly categorized. To support the proteomic results, the presence of four candidate proteins, ATR, BRG1, NPM1 and PARP-1, in the elutions was further characterized in this study. The binding and colocalization of these proteins with the TR were verified using chromatin immunoprecipitation and immunofluorescence in situ hybridization analysis. These newly identified TR binding proteins provide a number of clues and potential links to understanding the mechanisms regulating the replication, transcription, and genome maintenance of KSHV. This study will facilitate the generation and testing of new hypotheses to further our understanding of the mechanisms involved in KSHV persistence and its associated pathogenesis.


Assuntos
Herpesvirus Humano 8/metabolismo , Proteômica/métodos , Sequências Repetidas Terminais , Núcleo Celular/metabolismo , Cromatografia , Genoma , Ligantes , Espectrometria de Massas , Microscopia de Fluorescência , Nucleofosmina , Ligação Proteica , RNA/química , Spliceossomos/metabolismo , Replicação Viral
15.
J Virol ; 80(16): 7965-75, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16873253

RESUMO

Hypoxia can induce lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV) in primary effusion lymphoma (PEL) cells. However, the molecular mechanism of lytic reactivation of KSHV by hypoxia remains unclear. Here we show that the latency-associated nuclear antigen (LANA), which plays a crucial role in modulating viral and cellular gene expression, directly associated with a low oxygen responder, hypoxia-inducible factor-1 alpha (HIF-1 alpha). LANA enhanced not only the transcriptional activities of HIF-1 alpha but also its mRNA level. Coimmunoprecipitation and immunofluorescence studies documented a physical interaction between LANA and HIF-1 alpha in transiently transfected 293T cells as well as in PEL cell lines during hypoxia. Through sequence analysis, several putative hypoxia response elements (HRE-1 to -6) were identified in the essential lytic gene Rta promoter. Reporter assays showed that HRE-2 (-1130 to -1123) and HRE-5 and HRE-6 (+234 to +241 and +812 to +820, respectively, within the intron sequence) were necessary and sufficient for the LANA-mediated HIF-1 alpha response. Electrophoretic mobility shift assays showed HIF-1 alpha-dependent binding of a LANA protein complex specifically to the HRE-2, -5, and -6 motifs within the promoter regulatory sequences. This study demonstrates that hypoxia-induced KSHV lytic replication is mediated at least in part through cooperation of HIF-1 alpha with LANA bound to the HRE motifs of the Rta promoter.


Assuntos
Antígenos Virais/metabolismo , Regulação Viral da Expressão Gênica , Herpesvirus Humano 8/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas Imediatamente Precoces/genética , Proteínas Nucleares/metabolismo , Transativadores/genética , Proteínas Virais/genética , Anaerobiose/genética , Herpesvirus Humano 8/genética , Humanos , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Oxigênio/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/metabolismo , Elementos de Resposta/genética , Transcrição Gênica , Replicação Viral/genética
16.
J Virol ; 80(2): 697-709, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16378973

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) is predominantly associated with three human malignancies, KS, primary effusion lymphoma, and multicentric Castleman's disease. These disorders are linked to genomic instability, known to be a crucial component of the oncogenic process. Latency-associated nuclear antigen (LANA), encoded by open reading frame 73 of the KSHV genome, is a latent protein consistently expressed in all KSHV-associated diseases. LANA is important in viral genome maintenance and is associated with cellular and viral proteins to regulate viral and cellular gene expression. LANA interacts with the tumor suppressor genes p53 and pRb, indicating that LANA may target these proteins and promote oncogenesis. In this study, we generated cell lines which stably expressed LANA to observe the effects of LANA expression on cell phenotype. LANA expression in these stable cell lines showed a dramatic increase in chromosomal instability, indicated by the presence of increased multinucleation, micronuclei, and aberrant centrosomes. In addition, these stable cell lines demonstrated an increased proliferation rate and as well as increased entry into S phase in both stable and transiently transfected LANA-expressing cells. Additionally, p53 transcription and its transactivation activity were suppressed by LANA expression in a dose-dependent manner. LANA may therefore promote chromosomal instability by suppressing the functional activities of p53, thereby facilitating KSHV-mediated pathogenesis and cancer.


Assuntos
Antígenos Virais/metabolismo , Instabilidade Cromossômica , Herpesvirus Humano 8/imunologia , Proteínas Nucleares/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Antígenos Virais/genética , Linhagem Celular , Regulação para Baixo , Humanos , Proteínas Nucleares/genética , Sarcoma de Kaposi , Transcrição Gênica , Ativação Transcricional , Transfecção , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
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