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Abnormal adipose tissue formation is associated with metabolic disorders such as obesity, diabetes, and liver and cardiovascular diseases. Thus, identifying the novel factors that control adipogenesis is crucial for understanding these conditions and developing targeted treatments. In this study, we identified the melanosome-related factor MLPH as a novel adipogenic factor. MLPH was induced during the adipogenesis of 3T3-L1 cells and human mesenchymal stem cells. Although MLPH did not affect lipid metabolism, such as lipogenesis or lipolysis, adipogenesis was severely impaired by MLPH depletion. We observed that MLPH prevented excess reactive oxygen species (ROS) accumulation and lipid peroxidation during adipogenesis and in mature adipocytes. In addition, increased MLPH expression was observed under cirrhotic conditions in liver cancer cells and its overexpression also reduced ROS and lipid peroxidation. Our findings demonstrate that MLPH is a novel adipogenic factor that maintains redox homeostasis by preventing lipid peroxidation and ROS accumulation, which could lead to metabolic diseases.
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Alcohol-associated liver disease (ALD) is caused by excessive abuse of alcohol. One of the most representative causes of ALD is the action of acetaldehyde. Acetaldehyde is a toxic material produced when alcohol is metabolized through some enzymes, and it causes endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and tissue injury. In this study, we assessed the relationship between Progesterone receptor membrane component 1 (PGRMC1) and ALD because PGRMC1 is expressed in the ER and mitochondria in the liver. Using the chronic and binge alcohol feeding models, we assessed acetaldehyde level, liver damage, alcohol-degrading enzymes, and ER stress. Compared with wild-type (WT) mice ethanol-fed Pgrmc1 knockout (KO) mice had higher levels of alanine aminotransferase (ALT) and alcohol-degrading enzymes, and Pgrmc1 KO mice had high serum acetaldehyde and ER stress levels compared with WT mice with control and ethanol feeding. Loss of Pgrmc1 increased acetaldehyde production through increased expression of alcohol dehydrogenase and catalase, which led to increased ER stress and suggested that cell death was promoted. In conclusion, it has been proposed that the loss of PGRMC1 could promote ALD and cause liver damage in alcohol-abusing humans.NEW & NOTEWORTHY Loss of Pgrmc1 increased acetaldehyde production, and excess acetaldehyde consequently increased ER stress, which activates apoptosis. Since low expression of PGRMC1 is vulnerable to alcoholic liver damage, the loss of PGRMC1 expression may increase susceptibility to ALD.
Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Hepatopatias Alcoólicas , Humanos , Camundongos , Animais , Etanol/toxicidade , Etanol/metabolismo , Acetaldeído/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Fígado/metabolismo , Hepatopatias Alcoólicas/metabolismo , Estresse Oxidativo , Camundongos Knockout , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismoRESUMO
PURPOSE: To describe clinical manifestations and short-term prognosis of ocular motility disorders following coronavirus disease-2019 (COVID-19) vaccination. METHODS: Ocular motility disorders were diagnosed by clinical assessment, high-resolution magnetic resonance imaging, and laboratory testing. Clinical manifestations, short-term prognosis, and rate of complete recovery were analyzed. RESULTS: Sixty-three patients (37 males, 26 females) with a mean age of 61.6 ± 13.3 years (range, 22-81 years) were included in this study. Among 61 applicable patients with sufficient information regarding medical histories, 38 (62.3%) had one or more significant underlying past medical histories including vasculopathic risk factors. The interval between initial symptoms and vaccination was 8.6 ± 8.2 (range, 0-28) days. Forty-two (66.7%), 14 (22.2%), and 7 (11.1%) patients developed symptoms after the first, second, and third vaccinations, respectively. One case of internuclear ophthalmoplegia, 52 cases of cranial nerve palsy, two cases of myasthenia gravis, six cases of orbital diseases (such as myositis, thyroid eye disease, and IgG-related orbital myopathy), and two cases of comitant vertical strabismus with acute onset diplopia were found. Among 42 patients with follow-up data (duration: 62.1 ± 40.3 days), complete improvement, partial improvement, no improvement, and exacerbation were shown in 20, 15, 3, and 4 patients, respectively. CONCLUSION: This study provided various clinical features of ocular motility disorders following COVID-19 vaccination. The majority of cases had a mild clinical course while some cases showed a progressive nature. Close follow-up and further studies are needed to elucidate the underlying mechanisms and long-term prognosis.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Miastenia Gravis , Transtornos da Motilidade Ocular , Estrabismo , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , COVID-19/diagnóstico , COVID-19/epidemiologia , Vacinas contra COVID-19/efeitos adversos , Transtornos da Motilidade Ocular/diagnóstico , Transtornos da Motilidade Ocular/etiologia , Estrabismo/diagnósticoRESUMO
Changes in the DNA damage response (DDR) and cellular metabolism are two important factors that allow cancer cells to proliferate. DDR is a set of events in which DNA damage is recognized, DNA repair factors are recruited to the site of damage, the lesion is repaired, and cellular responses associated with the damage are processed. In cancer, DDR is commonly dysregulated, and the enzymes associated with DDR are prone to changes in ubiquitination. Additionally, cellular metabolism, especially glycolysis, is upregulated in cancer cells, and enzymes in this metabolic pathway are modulated by ubiquitination. The ubiquitin-proteasome system (UPS), particularly E3 ligases, act as a bridge between cellular metabolism and DDR since they regulate the enzymes associated with the two processes. Hence, the E3 ligases with high substrate specificity are considered potential therapeutic targets for treating cancer. A number of small molecule inhibitors designed to target different components of the UPS have been developed, and several have been tested in clinical trials for human use. In this review, we discuss the role of ubiquitination on overall cellular metabolism and DDR and confirm the link between them through the E3 ligases NEDD4, APC/CCDH1, FBXW7, and Pellino1. In addition, we present an overview of the clinically important small molecule inhibitors and implications for their practical use.
Assuntos
Neoplasias , Humanos , Ubiquitinação , Neoplasias/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Dano ao DNA , Ubiquitina/metabolismo , Reparo do DNARESUMO
Porcine epidemic diarrhea virus (PEDV) is an α-coronavirus causing severe diarrhea and high mortality rates in suckling piglets and posing significant economic impact. PEDV replication is completed and results in a large amount of RNA in the cytoplasm. Stress granules (SGs) are dynamic cytosolic RNA granules formed under various stress conditions, including viral infections. Several previous studies suggested that SGs were involved in the antiviral activity of host cells to limit viral propagation. However, the underlying mechanisms are poorly understood. This study aimed to delineate the molecular mechanisms regulating the SG response to PEDV infection. SG formation is induced early during PEDV infection, but as infection proceeds, this ability is lost and SGs disappear at late stages of infection (>18 h postinfection). PEDV infection resulted in the cleavage of Ras-GTPase-activating protein-binding protein 1 (G3BP1) mediated by caspase-8. Using mutational analysis, the PEDV-induced cleavage site within G3BP1 was identified, which differed from the 3C protease cleavage site previously identified. Furthermore, G3BP1 cleavage by caspase-8 at D168 and D169 was confirmed in vitro as well as in vivo The overexpression of cleavage-resistant G3BP1 conferred persistent SG formation and suppression of viral replication. Additionally, the knockdown of endogenous G3BP1 abolished SG formation and potentiated viral replication. Taken together, these data provide new insights into novel strategies in which PEDV limits the host stress response and antiviral responses and indicate that caspase-8-mediated G3BP1 cleavage is important in the failure of host defense against PEDV infection.IMPORTANCE Coronaviruses (CoVs) are drawing extensive attention again since the outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019. CoVs are prone to variation and own the transmission capability by crossing the species barrier resulting in reemergence. How CoVs manipulate the antiviral responses of their hosts needs to be explored. Overall, the study provides new insight into how porcine epidemic diarrhea virus (PEDV) impaired SG assembly by targeting G3BP1 via the host proteinase caspase-8. These findings enhanced the understanding of PEDV infection and might help identify new antiviral targets that could inhibit viral replication and limit the pathogenesis of PEDV.
Assuntos
Caspase 8/metabolismo , Infecções por Coronavirus/metabolismo , Grânulos Citoplasmáticos/metabolismo , Vírus da Diarreia Epidêmica Suína/fisiologia , Proteólise , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Replicação Viral , Animais , Caspase 8/genética , Chlorocebus aethiops , Infecções por Coronavirus/genética , Infecções por Coronavirus/patologia , Grânulos Citoplasmáticos/genética , Grânulos Citoplasmáticos/virologia , Células HEK293 , Humanos , Proteínas com Motivo de Reconhecimento de RNA/genética , Suínos , Células VeroRESUMO
BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory disease in humans, with a case fatality rate of approximately 35%, thus posing a considerable threat to public health. The lack of approved vaccines or antivirals currently constitutes a barrier in controlling disease outbreaks and spread. METHODS: In this study, using a mammalian expression system, which is advantageous for maintaining correct protein glycosylation patterns, we constructed chimeric MERS-CoV virus-like particles (VLPs) and determined their immunogenicity and protective efficacy in mice. RESULTS: Western blot and cryo-electron microscopy analyses demonstrated that MERS-CoV VLPs were efficiently produced in cells co-transfected with MERS-CoV spike (S), envelope, membrane and murine hepatitis virus nucleocapsid genes. We examined their ability as a vaccine in a human dipeptidyl peptidase 4 knock-in C57BL/6 congenic mouse model. Mice immunized with MERS VLPs produced S-specific antibodies with virus neutralization activity. Furthermore, MERS-CoV VLP immunization provided complete protection against a lethal challenge with mouse-adapted MERS-CoV and improved virus clearance in the lung. CONCLUSIONS: Overall, these data demonstrate that MERS-CoV VLPs have excellent immunogenicity and represent a promising vaccine candidate.
Assuntos
Infecções por Coronavirus , Coronavírus da Síndrome Respiratória do Oriente Médio , Vacinas de Partículas Semelhantes a Vírus , Vacinas Virais , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Microscopia Crioeletrônica , Mamíferos , Camundongos , Camundongos Endogâmicos C57BL , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Glicoproteína da Espícula de Coronavírus/genética , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas Virais/genéticaRESUMO
Aeromonas phage AHP-1 was originally isolated from crucian carp (Carassius carassius) tissue. It was able to infect Aeromonas hydrophila and A. salmonicida. Genome sequence analysis revealed a 218,317-bp-long linear genome with an overall G + C content of 47.9%, 315 open reading frames (ORFs), and 25 tRNA sequences. Its genome was found to contain 67 unique ORFs (21.26%) that did not show any homology to previously characterized proteins. A comparative genome analysis suggested that its closest neighbors are unclassified phages belonging to the genus Tequatrovirus of the subfamily Tevenvirinae.
Assuntos
Aeromonas , Genoma Viral , Myoviridae/genética , Filogenia , Análise de SequênciaRESUMO
In this study, we investigated the role of heat shock protein 70 (HSP70) in porcine epidemic diarrhoea virus (PEDV) replication. We found that PEDV infection induced strong HSP70 overexpression in the very early stage of infection. We also confirmed that HSP70 overexpression increased the speed of PEDV replication, resulting in the generation of more virions. In contrast, knockout of HSP70 in cells significantly downregulated PEDV protein expression, resulting in a significant reduction in PEDV replication. Most importantly, we confirmed that among the structural proteins of PEDV, membrane (M) proteins have this important role. We found that membrane proteins control cellular HSP70 expression in PEDV-infected cells. We confirmed HSP70/M complex formation by both immunoprecipitation and immunofluorescence assays. Additionally, PEDV M overexpression induced strong HSP70 expression. All our results clearly confirmed that in PEDV-infected cells, the M protein plays a very important role in PEDV replication in collaboration with HSP70.
Assuntos
Infecções por Coronavirus/veterinária , Proteínas M de Coronavírus/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Vírus da Diarreia Epidêmica Suína/fisiologia , Doenças dos Suínos/virologia , Replicação Viral , Animais , Infecções por Coronavirus/virologia , Biossíntese de Proteínas , Sus scrofa , SuínosRESUMO
BACKGROUND: The oncogene LSF (encoded by TFCP2) has been proposed as a novel therapeutic target for multiple cancers. LSF overexpression in patient tumors correlates with poor prognosis in particular for both hepatocellular carcinoma and colorectal cancer. The limited treatment outcomes for these diseases and disappointing clinical results, in particular, for hepatocellular carcinoma in molecularly targeted therapies targeting cellular receptors and kinases, underscore the need for molecularly targeting novel mechanisms. LSF small molecule inhibitors, Factor Quinolinone Inhibitors (FQIs), have exhibited robust anti-tumor activity in multiple pre-clinical models, with no observable toxicity. METHODS: To understand how the LSF inhibitors impact cancer cell proliferation, we characterized the cellular phenotypes that result from loss of LSF activity. Cell proliferation and cell cycle progression were analyzed, using HeLa cells as a model cancer cell line responsive to FQI1. Cell cycle progression was studied either by time lapse microscopy or by bulk synchronization of cell populations to ensure accuracy in interpretation of the outcomes. In order to test for biological specificity of targeting LSF by FQI1, results were compared after treatment with either FQI1 or siRNA targeting LSF. RESULTS: Highly similar cellular phenotypes are observed upon treatments with FQI1 and siRNA targeting LSF. Along with similar effects on two cellular biomarkers, inhibition of LSF activity by either mechanism induced a strong delay or arrest prior to metaphase as cells progressed through mitosis, with condensed, but unaligned, chromosomes. This mitotic disruption in both cases resulted in improper cellular division leading to multiple outcomes: multi-nucleation, apoptosis, and cellular senescence. CONCLUSIONS: These data strongly support that cellular phenotypes observed upon FQI1 treatment are due specifically to the loss of LSF activity. Specific inhibition of LSF by either small molecules or siRNA results in severe mitotic defects, leading to cell death or senescence - consequences that are desirable in combating cancer. Taken together, these findings confirm that LSF is a promising target for cancer treatment. Furthermore, this study provides further support for developing FQIs or other LSF inhibitory strategies as treatment for LSF-related cancers with high unmet medical needs.
Assuntos
Benzodioxóis/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Quinolonas/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Apoptose/genética , Benzodioxóis/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Senescência Celular/efeitos dos fármacos , Senescência Celular/genética , Cromossomos Humanos/efeitos dos fármacos , Cromossomos Humanos/genética , Cromossomos Humanos/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Microscopia Intravital , Terapia de Alvo Molecular/métodos , Neoplasias/genética , Neoplasias/patologia , Quinolonas/uso terapêutico , RNA Interferente Pequeno/metabolismo , Imagem com Lapso de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Lysyl oxidase (LOX) is a cell-secreted amine oxidase that crosslinks collagen and elastin in extracellular microenvironment. LOX-traceable nanoparticles (LOXab-NPs) consisting of LOX antibodies (LOXab) and paclitaxel, can accumulate at high concentrations at radiation-treated target sites, as a tumor-targeting drug carrier for chemotherapy. Tumor-targeting and anticancer effects of PLGA based LOXab-NPs in vitro and in vivo were evaluated at radiation-targeted site. In the in vivo A549 lung carcinoma xenograft model, we showed highly specific tumor targeting (above 7.0 times higher) of LOXab-NPs on irradiated tumors. Notably, systemically administered NPs delayed tumor growth, reducing tumor volumes by more than 2 times compared with non-irradiated groups (222% vs. >500%) over 2â¯weeks. Radiotropic LOXab-NPs can serve as chemotherapeutic vehicles for combined targeted chemo-radiotherapy in clinical oncology.
Assuntos
Apoptose/efeitos da radiação , Nanopartículas/química , Nanopartículas/uso terapêutico , Proteína-Lisina 6-Oxidase/metabolismo , Radiação Ionizante , Células A549 , Animais , Western Blotting , Células Cultivadas , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Proteína-Lisina 6-Oxidase/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We previously reported that podophyllotoxin acetate (PA) inhibits the growth and proliferation of non-small cell lung cancer (NSCLC) cells and also makes them more sensitive to radiation and chemotherapeutic agents. In an attempt to enhance PA activity, we synthesized 34 derivatives based on podophyllotoxin (PPT). Screening of the derivative compounds for anti-cancer activity against NSCLC led to the identification of ß-apopicropodophyllin (APP) as a strong anti-cancer agent. In addition to its role as an immunosuppressive regulator of the T-cell mediated immune response, the compound additionally showed anti-cancer activity against A549, NCI-H1299 and NCI-460 cell lines with IC50 values of 16.9, 13.1 and 17.1â¯nM, respectively. The intracellular mechanisms underlying the effects of APP were additionally examined. APP treatment caused disruption of microtubule polymerization and DNA damage, which led to cell cycle arrest, as evident from accumulation of phospho-CHK2, p21, and phospho-Cdc2. Moreover, APP stimulated the pro-apoptotic ER stress signaling pathway, indicated by elevated levels of BiP, phospho-PERK, phospho-eIF2α, CHOP and ATF4. We further observed activation of caspase-3, -8 and -9, providing evidence that both intrinsic and extrinsic apoptotic pathways were triggered. In vivo, APP inhibited tumor growth of NSCLC xenografts in nude mice by promoting apoptosis. Our results collectively support a novel role of APP as an anticancer agent that evokes apoptosis by inducing microtubule disruption, DNA damage, cell cycle arrest and ER stress.
Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Podofilina/farmacologia , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Estrutura Molecular , Podofilina/síntese química , Podofilina/químicaRESUMO
Upon shift to a hypoxic environment, cellular HIF-1α protein is stabilized, with a rapid decline in oxygen-sensitive hydroxylation. Several additional post-translational modifications of HIF-1α are critical in controlling protein stability during hypoxia. In the present study, we showed that SIRT1 stabilizes HIF-1α via direct binding and deacetylation during hypoxia. SIRT1 depletion or inactivation led to reduced hypoxic HIF-1α accumulation, accompanied by an increase in HIF-1α acetylation. Impaired HIF-1α accumulation was recovered upon inhibition of 26S proteasome activity, indicating that SIRT1 is essential for HIF-1α stabilization during hypoxia. Consistently, HIF-1α accumulation was enhanced upon overexpression of wild-type SIRT1, but not its dominant-negative form. SIRT1-mediated accumulation of HIF-1α protein led to increased expression of HIF-1α target genes, including VEGF, GLUT1 and MMP2, and ultimate promotion of cancer cell invasion. These findings collectively imply that hypoxic HIF-1α stabilization requires SIRT1 activation. Furthermore, SIRT1 protection of HIF-1α from acetylation may be a prerequisite for stabilization and consequent enhancement of cell invasion.
Assuntos
Hipóxia Celular , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Sirtuína 1/metabolismo , Acetilação , Sequência de Bases , Linhagem Celular , Primers do DNA , Humanos , Ligação Proteica , Estabilidade Proteica , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sirtuína 1/genéticaRESUMO
To understand the molecular mechanisms of Avian metapneumovirus (aMPV) and the requirements involved in the infection and fusion, trypsin treatment was done in the different stages of virus; before infection, during entry and after virus infection followed by aMPV infection. The growth kinetics of aMPV was compared in time dependent manner. The effect of trypsin was found in the later stage of aMPV infection increasing the numbers of infected cells with the significant higher titer of infectious virions to that of trypsin treated before infection, during entry and aMPV. A serine protease inhibitor reduced aMPV replication in a significant way, whereas cysteine peptidase (E-64), aspartic protease (pepstatin A), and metalloprotease (phosphoramidon) inhibitors had no effect on aMPV replication. Inoculation of aMPV on Vero cells expressing the membrane-associated protease TMPRSS2 resulted in higher virus titers than that inoculated on normal Vero cells and is statistically significant (p < 0.05). Also, an inhibitor of clathrin/caveolae-mediated endocytosis had no effect on virus progeny, indicating that aMPV does not use the endocytic pathway for entry but undergoes direct fusion. The effect of lysosomotropic agents was not significant, suggesting that aMPV does not require low-pH environment in endosomes to fuse its envelope with the plasma membrane.
Assuntos
Metapneumovirus/fisiologia , Tripsina/farmacologia , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Chlorocebus aethiops , Fusão de Membrana/efeitos dos fármacos , Metapneumovirus/classificação , Metapneumovirus/efeitos dos fármacos , Infecções por Paramyxoviridae/veterinária , Infecções por Paramyxoviridae/virologia , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Células Vero , Carga Viral/efeitos dos fármacosRESUMO
In this study, multi-drug resistant Escherichia coli Sw1 (E. coli Sw1) and active lytic phage EcSw was isolated from feces samples of Sus scrofa domesticus (piglet) suffering from diarrhea. Transmission electron microscopy (TEM) indicated that isolated EcSw belongs to the Myoviridae family with an icosahedral head (80 ± 4) and a long tail (180 ± 5 nm). The EcSw phage genome size was estimated to be approximately 75 Kb of double-stranded DNA (dsDNA). Phage dynamic studies show that the latent period and burst size of EcSw were approximately 20 min and 28 PFU per cell, respectively. Interestingly, the EcSw phage can tolerate a wide range of environmental conditions, such as temperature, pH and ions (Ca(2+) and Mg(2+)). Furthermore, genome sequence analysis revealed that the lytic genes of the EcSw phage are notably similar to those of enterobacteria phages. In addition, phage-antibiotic synergy has notable effects compared with the effects of phages or antibiotics alone. Inhibition of E. coli Sw1 and 0157:H7 strains showed that the limitations of host specificity and infectivity of EcSw. Even though, it has considerable potential for phage therapy for handling the problem of the emergence of multidrug resistant pathogens.
Assuntos
Terapia Biológica , Myoviridae/metabolismo , Sus scrofa/virologia , Animais , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/virologia , Genoma Viral , Especificidade de Hospedeiro/genética , Concentração de Íons de Hidrogênio , Metais , Viabilidade Microbiana , Microscopia Eletrônica de Transmissão , Myoviridae/genética , Myoviridae/patogenicidade , Análise de Sequência de DNA , Sus scrofa/microbiologia , TemperaturaRESUMO
More than two-thirds of breast cancers express the estrogen receptor (ER) and depend on estrogen for growth and survival. Therapies targeting ER function, including aromatase inhibitors that block the production of estrogens and ER antagonists that alter ER transcriptional activity, play a central role in the treatment of ER+ breast cancers of all stages. In contrast to ER- breast cancers, which frequently harbor mutations in the p53 tumor suppressor, ER+ breast cancers are predominantly wild type for p53. Despite harboring wild-type p53, ER+ breast cancer cells are resistant to chemotherapy-induced apoptosis in the presence of estrogen. Using genome-wide approaches, we have addressed the mechanism by which ER antagonizes the proapoptotic function of p53. Interestingly, both ER agonists such as estradiol and the selective ER modulator (SERM) tamoxifen promote p53 antagonism. In contrast, the full ER antagonist fulvestrant blocks the ability of ER to inhibit p53-mediated cell death. This inhibition works through a mechanism involving the modulation of a subset of p53 and ER target genes that can predict the relapse-free survival of patients with ER+ breast cancer. These findings suggest an improved strategy for the treatment of ER+ breast cancer using antagonists that completely block ER action together with drugs that activate p53-mediated cell death.
Assuntos
Apoptose/fisiologia , Neoplasias da Mama/patologia , Receptores de Estrogênio/fisiologia , Proteína Supressora de Tumor p53/fisiologia , Neoplasias da Mama/fisiopatologia , Feminino , HumanosRESUMO
Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells.
Assuntos
Dano ao DNA , Glucuronosiltransferase/biossíntese , Tolerância a Radiação , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos da radiação , Indução Enzimática/efeitos da radiação , Raios gama , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Técnicas de Silenciamento de Genes , Glucuronosiltransferase/genética , Histonas/metabolismo , Humanos , Hialuronan Sintases , Regulação para Cima/genética , Regulação para Cima/efeitos da radiaçãoRESUMO
Chromatin immunoprecipitation identifies specific interactions between genomic DNA and proteins, advancing our understanding of gene-level and chromosome-level regulation. Based on chromatin immunoprecipitation experiments using validated antibodies, we define the genome-wide distributions of 19 histone modifications, one histone variant, and eight chromatin-associated proteins in Caenorhabditis elegans embryos and L3 larvae. Cluster analysis identified five groups of chromatin marks with shared features: Two groups correlate with gene repression, two with gene activation, and one with the X chromosome. The X chromosome displays numerous unique properties, including enrichment of monomethylated H4K20 and H3K27, which correlate with the different repressive mechanisms that operate in somatic tissues and germ cells, respectively. The data also revealed striking differences in chromatin composition between the autosomes and between chromosome arms and centers. Chromosomes I and III are globally enriched for marks of active genes, consistent with containing more highly expressed genes, compared to chromosomes II, IV, and especially V. Consistent with the absence of cytological heterochromatin and the holocentric nature of C. elegans chromosomes, markers of heterochromatin such as H3K9 methylation are not concentrated at a single region on each chromosome. Instead, H3K9 methylation is enriched on chromosome arms, coincident with zones of elevated meiotic recombination. Active genes in chromosome arms and centers have very similar histone mark distributions, suggesting that active domains in the arms are interspersed with heterochromatin-like structure. These data, which confirm and extend previous studies, allow for in-depth analysis of the organization and deployment of the C. elegans genome during development.
Assuntos
Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Cromossomos/metabolismo , Histonas/metabolismo , Animais , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Genes Ligados ao Cromossomo X/genética , Histonas/genética , Metilação , Metiltransferases/metabolismo , Membrana Nuclear/metabolismo , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Sequências Repetitivas de Ácido Nucleico/genéticaRESUMO
Toll-like receptors (TLRs) are critical components to stimulate immune responses against various infections. Recently, TLR agonists have emerged as a promising way to activate anti-tumor immunity. L-pampo, a TLR1/2 and TLR3 agonist, induces humoral and cellular immune responses and also causes cancer cell death. In this study, we investigated the L-pampo-induced signals and delineated their interactions with molecular signaling pathways using RNA-seq in immune cells and colon and prostate cancer cells. We first constructed a template network with differentially expressed genes and influential genes from network propagation using the weighted gene co-expression network analysis. Next, we obtained perturbed modules using the above method and extracted core submodules from them by conducting Walktrap. Finally, we reconstructed the subnetworks of major molecular signals utilizing a shortest path-finding algorithm, TOPAS. Our analysis suggests that TLR signaling activated by L-pampo is transmitted to oxidative phosphorylation (OXPHOS) with reactive oxygen species (ROS) through PI3K-AKT and JAK-STAT only in immune and prostate cancer cells that highly express TLRs. This signal flow may further sensitize prostate cancer to L-pampo due to its high basal expression level of OXPHOS and ROS. Our computational approaches can be applied for inferring underlying molecular mechanisms from complex gene expression profiles.
Assuntos
Redes Reguladoras de Genes , Transdução de Sinais , Receptores Toll-Like , Humanos , Receptores Toll-Like/agonistas , Receptores Toll-Like/metabolismo , Linhagem Celular Tumoral , Espécies Reativas de Oxigênio/metabolismo , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Fosforilação Oxidativa , Agonistas do Receptor Semelhante a TollRESUMO
Japanese encephalitis virus (JEV), a flavivirus transmitted by mosquitoes, has caused epidemics and severe neurological diseases in Asian countries. In this study, we developed a cDNA infectious clone, pBAC JYJEV3, of the JEV genotype 3 strain (EF571853.1) using a bacterial artificial chromosome (BAC) vector. The constructed infectious clone was transfected into Vero cells, where it exhibited infectivity and induced cytopathic effects akin to those of the parent virus. Confocal microscopy confirmed the expression of the JEV envelope protein. Comparative analysis of growth kinetics revealed similar replication dynamics between the parental and recombinant viruses, with peak titers observed 72 h post-infection (hpi). Furthermore, plaque assays demonstrated comparable plaque sizes and morphologies between the viruses. Cryo-electron microscopy confirmed the production of recombinant virus particles with a morphology identical to that of the parent virus. Immunization studies in mice using inactivated parental and recombinant viruses revealed robust IgG responses, with neutralizing antibody production increasing over time. These results showcase the successful generation and characterization of a recombinant JEV3 virus and provide a platform for further investigations into JEV pathogenesis and vaccine development.
RESUMO
Porcine epidemic diarrhea virus is attenuated upon adaptation to cell culture. Exclusively genomic mutations have been traced to the ORF3 gene of the laboratory strains. Previous attempts to express the protein were unsuccessful. We sought to express the ORF3 protein in both mammalian and bacteria cells as a prerequisite for investigation of the protein's role. For prokaryotic expression, two vector systems, pET28-a(+) and pGEX-4T-1 were constructed and expressed in Escherichia coli cells. For eukaryotic analyses, ORF3/pEGFP-C1 vector constructs were expressed in human embryonic, green monkey kidney and mouse fibrous cells. Intriguingly, there was minimal expression of the ORF3 gene. Following a documented hint that truncated ORF3 revealed higher expression, ORF3 gene was truncated. The simple modular architecture research tool analysis predicted two transmembrane domains between amino acid (aa) 41-63 and aa 76-98. Consequently, we generated two fragments; ORF-N (aa 1-98) inclusive of transmembrane domains and ORF3-C (aa 99-224). These truncated sequences were constructed as the whole gene here referred to as ORF3 wild type (wt). Coomassie blue stained gels revealed bands of ORF3-C expressed as a fusion protein of 17.5 and 39â¯kDa in pET28-a(+) and pGEX-4T-1 vectors, respectively. In contrast, ORF3-N was not. Additionally, ORF3-N induction decreased total cellular proteins suggesting inhibition of protein synthesis or metabolism. Solubility tests carried out at 30⯰C, 25⯰C and 18⯰C showed that ORF3 formed inclusion bodies. Similar findings were observed in mammalian cells. Noteworthy, morphological distortions appeared in mammalian cells expressing ORF3 protein or its truncated mutants suggesting significance in host viability.