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1.
Int J Biol Macromol ; 268(Pt 1): 131734, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38653431

RESUMO

SARS-CoV-2 infection results in cytokine burst, leading to proinflammatory responses in lungs of COVID-19 patients. SARS-CoV-2 ORF3a triggers the generation of proinflammatory cytokines. However, the underlying mechanism of dysregulation of proinflammatory responses is not well understood. We studied the role of microRNA in the generation of proinflammatory responses as a bystander effect of SARS-CoV-2 ORF3a in human lung epithelial cells. We observed upregulation of hsa-miR-155-5p in SARS-CoV-2 ORF3a transfected human lung epithelial cells, which led to the reduced expression of SHIP1. This resulted in phosphorylation of AKT and NF-κB, which further led to the increased expression of the proinflammatory cytokines IL-6 and TNF-α. Additionally, overexpression and knockdown studies of hsa-miR-155-5p were performed to confirm the role of hsa-miR-155-5p in the regulation of the SHIP1. We demonstrated that hsa-miR-155-5p modulates the proinflammatory response by activating the PI3K/AKT pathway through the inhibition of SHIP1 in SARS-CoV-2 ORF3a transfected human lung epithelial cells.


Assuntos
COVID-19 , Células Epiteliais , Pulmão , MicroRNAs , Fosfatidilinositol 3-Quinases , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Proteínas Proto-Oncogênicas c-akt , SARS-CoV-2 , Transdução de Sinais , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/genética , Fosfatidilinositol 3-Quinases/metabolismo , COVID-19/genética , COVID-19/virologia , COVID-19/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Pulmão/virologia , Pulmão/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , NF-kappa B/metabolismo , Interleucina-6/metabolismo , Interleucina-6/genética , Células A549
2.
Parasite Immunol ; 45(5): e12978, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37073092

RESUMO

A sensitive and specific diagnostic kit is crucial for the detection of human lymphatic filariasis at the early stage of infection as the existing diagnostic tools are inefficient and expensive. In the present study, we have cloned and expressed Brugia malayi HSP70 (BmHSP70) protein and characterized it as a potential antigen for diagnosis of the asymptomatic microfilariae stage of Wuchereria. bancrofti infection using ELISA, western blot, and bioinformatics tools. The antigenic efficacy of BmHSP70 was also compared with ScHSP70. The BmHSP70 and ScHSP70 peptide showed highly antigenic in nature and they showed immunogenic cross-reactivity endemic normal (EN) < chronic (CH) < microfilaraemic (MF) in IgG, IgG1, and IgG4 ELISA. IgG4-specific immunoblotting of BmHSP70 with MF sera further explicated its stage-specific antigenic cross-reactivity. These antigens (ScHSP70 and BmHSP70) showed a positive immunogenic correlation with the number of MF in blood samples. Thus, proposing BmHSP70 as a potential immunodiagnostic antigen against lymphatic filariasis. A triplet of GGMP tetrapeptide specific to the filarial HSP70 was also identified which was absent in human HSP70. In terms of sensitivity and specificity of antigens, these results suggest that recombinant BmHSP70 is a good antigen and could be used to diagnose early-stage of microfilariae infection.


Assuntos
Brugia Malayi , Filariose Linfática , Animais , Humanos , Filariose Linfática/diagnóstico , Wuchereria bancrofti , Antígenos de Helmintos , Microfilárias , Imunoglobulina G , Proteínas de Choque Térmico HSP70 , Anticorpos Anti-Helmínticos , Imunidade
3.
Drug Dev Res ; 83(8): 1867-1878, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36219508

RESUMO

The available antifilarial medications are effective only against the larval stage of the filarial parasite. As a result, there is a pressing need for an adulticidal drug. The development of drugs requires the identification of molecular targets that are critical for parasite life. In this study, we observed the effect of 17-N-allyl-17-demethoxygeldanamycin on the survival of adult filarial parasites. The 17-N-allyl-17-demethoxygeldanamycin (17-AAG) is a derivative of geldanamycin (GA), which is an inhibitor of heat shock protein (HSP)90. It is less toxic as compared to geldanamycin. The motility and viability of the adult filarial parasite Setaria cervi were decreased on exposure to 17-AAG at 2.5 and 5.0 µM/ml concentrations. The 17-AAG treated parasites showed induction of oxidative stress as evidenced by decreased activity of various antioxidant enzymes like glutathione s-transferase, glutathione reductase, thioredoxin reductase, and an increase in ROS production in comparison to control. Oxidative stress may lead to altered calcium homeostasis. Indeed, in 17-AAG treated worms, there was a rise in calcium in the cytosol and mitochondria, as well as a decrease in the ER. We also observed enhanced activity of phospholipase C in the treated parasite, suggesting the opening of calcium channels located on the ER membrane. ER stress is marked by a reduced level of protein disulfide isomerase. Further, 17-AAG treated worms showed an increase in apoptotic marker enzyme activities like calpain, cyt-c, and caspase-3. The 2D-gel electrophoresis technique showed 142 protein spots in the control and 112 spots in the 17-AAG treated parasite. Thus, 17-AAG induced oxidative stress, and altered calcium, and proteostasis of parasites, which led to apoptosis.


Assuntos
Antineoplásicos , Parasitos , Animais , Cálcio , Apoptose , Antineoplásicos/farmacologia
4.
Protein J ; 41(6): 613-624, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36271977

RESUMO

Prolyl oligopeptidase (POP) plays a crucial role in the processing and degradation of neuropeptides and regulates inositol trisphosphate (IP3) signaling in mammals. We have reported that POP inhibition leads to IP3-mediated calcium efflux leading to mitochondrial-mediated apoptosis in the filarial parasite Setaria cervi. This study further elucidates the effect of altered calcium homeostasis on the proteome of filarial parasites. Adult parasites were treated with POP's specific inhibitor, Z-Pro-prolinal (ZPP), for 7 h. Cytosolic and mitochondrial proteome was analyzed using 2D gel electrophoresis coupled with MALDI-MS/MS. Phosphoproteins were also analyzed in the cytosolic fraction of the parasites. The phosphoprotein analysis revealed 7, and 9 spots in the cytosolic fraction of control and ZPP-treated parasites, respectively. The two identified protein spots in the treated set were found to be involved in G protein signaling. In cytosolic fraction, 109 and 112 protein spots were observed in control and treated parasites, respectively. Of these, 56 upregulated and 32 downregulated protein spots were observed in the treated set. On the other hand, 50 and 47 protein spots were detected in the mitochondrial fraction of control and treated parasites, respectively. Of these spots, 18 upregulated and 12 down-regulated protein spots were found in treated parasites. In silico analysis showed that the identified proteins were involved in energy metabolism, calcium signaling, stress response, and cytoskeleton organization. These findings correlate with our previous results suggesting the important regulatory role of POP in signaling and different metabolic pathways of filarial parasites.


Assuntos
Parasitos , Prolil Oligopeptidases , Animais , Proteômica , Espectrometria de Massas em Tandem , Proteoma , Cálcio , Mamíferos
5.
Artigo em Inglês | MEDLINE | ID: mdl-35985449

RESUMO

Lymphatic filariasis caused by filarial nematode is an important disease leading to considerable morbidity throughout tropical countries. Even after specific elimination programs, the disease continue to spread in endemic countries. Thus newer therapeutic interventions are urgently needed to control the spread. In the present study, we have seen the effect of andrographolide (andro), a diterpenoid lactone from the leaves of Andrographis paniculata on filarial parasite Setaria cervi. There was time and concentration dependent decrease in motility and viability leading to death of parasite after 6 h of the exposure of andro. Andro showed potential antifilarial activity with an IC50 value of 24.80 µM assessed through MTT assay. There was concentration dependent decrease in the antioxidant enzymes activity and increase in proapoptotic markers after 5 h exposure of andro. Further, molecular docking analysis revealed that andro binds with filarial glutathione-S-transferase at glutathione (GSH) binding site and inhibiting enzyme activity competitively. Andro induced oxidative stress mediated apoptosis in parasites as evidenced by increase in the intracellular reactive oxygen species (ROS) and apoptotic markers.Therefore this study suggested that andro could be further explored as a new antifilarial drug.


Assuntos
Diterpenos , Parasitos , Setaria (Nematoide) , Animais , Bovinos , Diterpenos/metabolismo , Diterpenos/farmacologia , Glutationa/metabolismo , Simulação de Acoplamento Molecular , Setaria (Nematoide)/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-34744019

RESUMO

GRP94, a member of HSP90 family, is involved in folding and degradation of endoplasmic reticulum proteins. The proteome analysis of Setaria cervi, a bovine filarial parasite showed that a 91 kDa protein was over expressed, after the parasites were maintained in glucose deprived medium. The MALDI- LC/MS analysis of the 91 kDa band confirmed it as endoplasmin precursor (GRP94). Amino acid sequence alignment of S.cervi GRP94 exhibited maximum similarity with human filarial parasite Wuchereria bancrofti, Brugia malayi and Loa loa GRP94. Tunicamycin treatment of S. cervi worms revealed that the expression of GRP94 is associated with ER stress. Transcription of S. cervi grp94 as well as igf is regulated by transcription factors ATF-6 and XBP-1S which was confirmed by Real Time PCR. Moreover, marked alteration in the expression of igf after 3 h and 6 h of drug treatment suggested propagation of survival pathway under ER stress. The activities of ER stress markers protein disulphide isomerase and glycosyltransferase were significantly reduced after 6 h of tunicamycin treatment. The present findings thus indicate that the expression of GRP94 and regulation of its expression is under ER stress in Setaria cervi. To our knowledge this is the first report of identification of GRP94, in any filarial parasite till date.


Assuntos
Estresse do Retículo Endoplasmático , Proteínas de Choque Térmico HSP70/genética , Proteínas de Helminto/genética , Proteínas de Membrana/genética , Setaria (Nematoide) , Animais , Setaria (Nematoide)/genética
7.
PLoS One ; 16(6): e0253269, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34138962

RESUMO

AMP-activated protein kinase (AMPK) is an evolutionarily conserved energy sensor. Activation of AMPK leads to a number of metabolic benefits, including improved mitochondrial function in skeletal muscle and lowering of serum glucose levels in type-2 diabetes models. However, direct activation of AMPK leads to cardiac enlargement, and an alternative strategy that activates AMPK without affecting the heart is needed. Inhibition of phosphodiesterase 4 (PDE4), which is poorly expressed in the human heart, activates AMPK in other tissues. In a screen to identify novel PDE4 inhibitors, we discovered compound CBU91, which is 5-10 fold more potent than rolipram, the best characterized PDE4 inhibitor. CBU91, like rolipram, is able to activate AMPK and Sirt1 and increase mitochondrial function in myotubes. These findings suggest that activation of AMPK in myotubes is a general property of PDE4 inhibition and that PDE4 inhibition may activate AMPK in metabolically relevant tissues without affecting the heart.


Assuntos
Adenilato Quinase/metabolismo , Mitocôndrias Musculares/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo , Animais , AMP Cíclico/metabolismo , Camundongos , Mitocôndrias Musculares/metabolismo , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Biogênese de Organelas , Rolipram/farmacologia
8.
Vet Parasitol ; 290: 109357, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33516120

RESUMO

In this ex vivo study, S. cervi parasitoses were treated with Ivermectin (50 µM), Albendazole (200 µM) alone and Ivermectin + Albendazole (50 + 200 µM) at 37°C for 8 h and the motility and viability of the parasitoses were evaluated. Individually both drugs Ivermectin (Iver) and Albendazole (Alb) are reported to affect the function and integrity of ER, however till date, no reports are available on the functional changes in ER due to a combined Iver and Alb treatment of bovine helminth parasitosis. Here, we report the lethal effect of a combination treatment of Iver and Alb against adult bovine filarial parasitosis Setaria cervi. The underlying mechanism of drug action was elucidated by performing a systematic biochemical, molecular and proteomics based study. Altered calcium homeostasis in drug treated parasitoses lead to reduction in levels of total Endoplasmic Reticulum (ER) calcium by 50 % and 61 % and elevation by 50 % and 63 % in cytosol in Iver alone and Iver + Alb treated parasitoses respectively. Further, it was found that upregulated expression of ER localized GRP94, galactosyltransferase and glycosyltransferase activity in addition to reduction in activity of PDI indicated ER stress mechanisms being operative under combined drug treatment. Marked rise of 79 % reactive oxygen species and reduced antioxidant levels induced oxidative stress in drug treated parasitosis. The collective effect of both ER and oxidative stress might have triggered apoptosis, as evidenced by the elevated calpain activity, reduction of 67 % in cytochrome c oxidase and 83 % rise in caspase-3 activity in the Iver + Alb treated parasitoses respectively. The ER proteome analysis by 2D gel electrophoresis revealed 76 spots in the control and 56 spots in the treated proteome. A MALDI-MS/MS analysis of some of the differentially expressed spots of the combination drug treated parasitoses identified glucuronosyltransferase as a major upregulated protein with a fold change of 1.81. Trafficking protein, acyl transferase, MATH involved in protein folding were also found to be downregulated. Thus, this study based on biochemical and proteomic approaches indicates that a combination of anti-filarial drugs Iver and Alb can alter calcium homeostasis in bovine filarial parasitosis leading to induction of ER stress culminating into apoptosis.


Assuntos
Albendazol/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ivermectina/farmacologia , Setaria (Nematoide)/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Albendazol/administração & dosagem , Animais , Antiparasitários/administração & dosagem , Antiparasitários/farmacologia , Biomarcadores , Quimioterapia Combinada , Feminino , Ivermectina/administração & dosagem , Atividade Motora/efeitos dos fármacos , Estresse Oxidativo
9.
Parasite Immunol ; 42(11): e12777, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32681576

RESUMO

AIM: Identification of a 29 kDa heat stress protein in filarial parasite Setaria cervi and evaluation of its diagnostic potential against lymphatic filariasis. METHODS AND RESULTS: The Heat shock proteins (HSPs) were induced in filarial parasite S cervi by incubated at 42°C for 2 hours. The 10% SDS-PAGE of cytosolic extract showed several over-expressed bands. The MALDI-LC/MS analysis of 29 kDa band showed 100% similarity with Bm14-3-3 like protein 2. Multiple sequence alignment of Bm14-3-3 like protein 2 sequence with W bancrofti, Caenorhabditis elegans; Loa loa and Homo sapiens showed 100%, 86%, 83% and 78%, sequence similarity respectively. The antigenic efficacy of Sc14-3-3 protein was evaluated with different filarial sera using ELISA which showed cross-reactivity in order to Endemic Normal (EN) < Microfilaraemic (MF) < Chronic(CH) with IgG1 and EN < CH < MF in IgG4 ELISA. IgG1- and IgG4-specific immunoblotting with CH and MF sera further explicated its specific antigenic cross-reactivity. CONCLUSION: A 29 kDa heat shock protein of S cervi was identified as 14-3-3 protein having 100% homology to human filarial parasite B malayi. It showed strong reactivity with IgG1 and IgG4 subclass antibodies of W bancrofti-infected human sera suggesting that 14-3-3 protein could be used as a vaccine/ diagnostic marker.


Assuntos
Anticorpos Anti-Helmínticos/imunologia , Filariose Linfática/diagnóstico , Proteínas de Choque Térmico/imunologia , Imunoglobulina G/imunologia , Setaria (Nematoide)/imunologia , Wuchereria bancrofti/imunologia , Sequência de Aminoácidos , Animais , Biomarcadores/análise , Reações Cruzadas , Filariose Linfática/imunologia , Filariose Linfática/parasitologia , Feminino , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Proteínas de Helminto/metabolismo , Humanos , Alinhamento de Sequência , Setaria (Nematoide)/genética
10.
Biochimie ; 165: 258-266, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446011

RESUMO

Phosphoglycerate kinase (PGK) is a key enzyme of glycolysis which also acts as a mediator of DNA replication and repair in the nucleus. We have cloned and expressed PGK in Brugia malayi. The rBmPGK was found to be 415 amino acid residues long having 45 kDa subunit molecular weight. This enzyme was also identified in different life stages of bovine filarial parasite Setaria cervi. The enzyme activity was highest in microfilarial stage followed by adult female and male as also shown by real time PCR in the present study. Further using BmPGK primers the cDNA prepared from S. cervi was amplified and sequenced which showed 100% homology with Brugia malayi PGK. B. malayi and S. cervi, PGK consists of conserved calmodulin binding domain (CaMBD) having 21 amino acids. In the present study we have shown the CaMBD binds to calcium-calmodulin and regulates its activity. The binding of calmodulin (CaM) with CaMBD was confirmed using calmodulin agarose binding pull down assay, which showed that the rBmPGK binds to CaM agarose-calcium dependent manner. The effect of CaM-Ca2+on the activity of rBmPGK was studied at different concentration of CaM (0.01-5.0 µM) and calcium chloride (0.01-100 µM). The rBmPGK was activated up to 85% in the presence of CaM at 1 µM and 10 µM concentration of CaCl2. Interestingly this activation was abrogated by metal chelator EDTA. Similar results were shown in case of Setaria cervi PGK. A significant increase (90 ±â€¯10) % in ScPGK activity was observed in the presence of CaM and CaCl2 at 1.0 µM and 1.0 mM respectively, further increase in the conc. of CaCl2, the activity of ScPGK was found to be decreased like rBmPGK. Bioinformatics studies have also confirmed the interaction between CaMBD and CaM which showed CaM interacted to Phe 206, Gln 220, Arg 223 and Asn 224 of rBmPGK CaM binding domain. On the basis of these findings, it has been suggested that the activity of filarial PGK could be regulated in cells by Ca2+-CaM depending upon the concentration of calcium. To the best of our knowledge this is first report in filarial parasite.


Assuntos
Brugia Malayi/enzimologia , Calmodulina/metabolismo , Fosfoglicerato Quinase/química , Setaria (Nematoide)/enzimologia , Animais , Cálcio/metabolismo , Bovinos , Ligação Proteica , Domínios Proteicos
11.
J Mol Cell Cardiol ; 132: 60-70, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31051182

RESUMO

Phosphodiesterase type 3 (PDE3) inhibitors block the cAMP hydrolyzing activity of both PDE3 isoforms, PDE3A and PDE3B, which have distinct roles in the heart. Although PDE3 inhibitors improve cardiac function in heart disease patients, they also increase mortality. Nevertheless, PDE3 inhibitors can provide benefit to non-ischemic heart disease patients and are used extensively to treat heart failure in dogs. Since the isoform-dependence of the complex cardiac actions of PDE3 inhibition in diseased hearts remains unknown, we assessed the effects of PDE3 inhibitors as well as gene ablation of PDE3A or PDEB in mice following the induction of non-ischemic heart disease by pressure-overload with transverse-aortic constriction (TAC). As expected, after 6 weeks of TAC, mice exhibited left ventricular contractile dysfunction, dilation, hypertrophy and interstitial fibrosis, in association with increased macrophage numbers, activation of p38 MAPK and elevated PDE3 activity. Chronic PDE3 inhibition with milrinone (MIL), at doses that did not affect either cardiac contractility or arterial blood pressure, profoundly attenuated the adverse ventricular remodeling, reduced macrophage number and diminished p38-MAPK activation induced by TAC. Surprisingly, whole-body ablation of PDE3A, but not PDE3B, provided similar protection against TAC-induced adverse ventricular remodeling, and the addition of MIL to mice lacking PDE3A provided no further protection. Our results support the conclusion that PDE3A plays an important role in adverse cardiac remodeling induced by chronic pressure overload in mice, although the underlying biochemical mechanisms remain to be fully elucidated. The implications of this conclusion on the clinical use of PDE3 inhibitors are discussed.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/fisiologia , Cardiopatias/patologia , Estresse Mecânico , Remodelação Ventricular , Animais , Cardiopatias/etiologia , Cardiopatias/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
12.
J Cardiovasc Dev Dis ; 5(1)2018 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29415428

RESUMO

Isoforms in the PDE3 family of cyclic nucleotide phosphodiesterases have important roles in cyclic nucleotide-mediated signalling in cardiac myocytes. These enzymes are targeted by inhibitors used to increase contractility in patients with heart failure, with a combination of beneficial and adverse effects on clinical outcomes. This review covers relevant aspects of the molecular biology of the isoforms that have been identified in cardiac myocytes; the roles of these enzymes in modulating cAMP-mediated signalling and the processes mediated thereby; and the potential for targeting these enzymes to improve the profile of clinical responses.

13.
J Clin Diagn Res ; 11(9): EC01-EC04, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29207712

RESUMO

INTRODUCTION: In light of literature and controversy that exists in various cervical lesions, this prospective study was designed to explore the expression of Human Epidermal Growth Factor Receptor-2 (HER-2/neu) in the cervical lesions and its correlation with the histopathological grade and type of tumour. Immunohistochemistry (IHC) was performed to evaluate HER-2/neu expression as it is the most reliable method of detecting overexpression of HER-2/neu. AIM: To assess the role of HER-2/neu expression in premalignant and malignant lesions of uterine cervix. MATERIALS AND METHODS: Seventy cases of premalignant and malignant cervical lesions received in our department from January 2015 to December 2016, were included in study and Polyclonal Rabbit Anti-Human c-erbB-2 oncoprotein from DAKO was used. Standard streptovidin-biotin peroxidase method of IHC was followed. A golden brown membrane and cytoplasmic staining was taken as a positive reaction and intensity of expression was graded according to the 2014 ASCO/CAP guidelines for HER-2/neu reporting. RESULTS: Out of total 70 cases, HER-2/neu expression scores were 0 in 64.3% {23 cases of Cervical Intraepithelial Neoplasia (CIN) and 22 of Squamous Cell Carcinoma (SCC)}, +1 in 22.9%, (04 cases of CIN and 12 of SCC) +2 in 10% (06 cases of SCC and 01 of adenosquamous carcinoma) and +3 in 2.9% (02 cases of adenocarcinoma) cases. HER-2/neu overexpression rate was significantly higher in malignant (48.8%) as compared to pre malignant (14.8%) cases (p=0.004) and expression scores were higher (+2 and +3) in 20.9% of malignant cases as compared to none of pre malignant cases (p=0.020). Significant higher HER-2/neu scores are seen (+2 and +3) in all the adenocarcinoma cases as compared to 15% cases of SCC (p<0.001). Among malignant cases, HER-2/neu expression was statistically significantly higher in {Moderately Differentiated (MD) + Poorly Differentiated (PD)} 59.09% as compared to {Well Differentiated (WD)} 38.09% cases (p=0.090). CONCLUSION: Study shows that expression of HER-2/neu is relatively lower in cervical lesions. However, the results of our study show that with shift from well to poorly differentiated lesions; the HER-2/neu expression rate shows an incremental trend.

14.
EBioMedicine ; 18: 128-138, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28396013

RESUMO

The specific Sirt1 activator SRT1720 increases mitochondrial function in skeletal muscle, presumably by activating Sirt1. However, Sirt1 gain of function does not increase mitochondrial function, which raises a question about the central role of Sirt1 in SRT1720 action. Moreover, it is believed that the metabolic effects of SRT1720 occur independently of AMP-activated protein kinase (AMPK), an important metabolic regulator that increases mitochondrial function. Here, we show that SRT1720 activates AMPK in a Sirt1-independent manner and SRT1720 activates AMPK by inhibiting a cAMP degrading phosphodiesterase (PDE) in a competitive manner. Inhibiting the cAMP effector protein Epac prevents SRT1720 from activating AMPK or Sirt1 in myotubes. Moreover, SRT1720 does not increase mitochondrial function or improve glucose tolerance in AMPKα2 knockout mice. Interestingly, weight loss induced by SRT1720 is not sufficient to improve glucose tolerance. Therefore, contrary to current belief, the metabolic effects produced by SRT1720 require AMPK, which can be activated independently of Sirt1.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glucose/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Mitocôndrias/efeitos dos fármacos , Sirtuína 1/metabolismo , Proteínas Quinases Ativadas por AMP/química , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/genética , Animais , Linhagem Celular , AMP Cíclico/metabolismo , Intolerância à Glucose , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Mutagênese Sítio-Dirigida , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Diester Fosfórico Hidrolases/química , Diester Fosfórico Hidrolases/metabolismo , Fosforilação/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/química , Sirtuína 1/genética
15.
Sci Rep ; 7: 40445, 2017 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-28084425

RESUMO

Understanding mechanisms by which a population of beige adipocytes is increased in white adipose tissue (WAT) reflects a potential strategy in the fight against obesity and diabetes. Cyclic adenosine monophosphate (cAMP) is very important in the development of the beige phenotype and activation of its thermogenic program. To study effects of cyclic nucleotides on energy homeostatic mechanisms, mice were generated by targeted inactivation of cyclic nucleotide phosphodiesterase 3b (Pde3b) gene, which encodes PDE3B, an enzyme that catalyzes hydrolysis of cAMP and cGMP and is highly expressed in tissues that regulate energy homeostasis, including adipose tissue, liver, and pancreas. In epididymal white adipose tissue (eWAT) of PDE3B KO mice on a SvJ129 background, cAMP/protein kinase A (PKA) and AMP-activated protein kinase (AMPK) signaling pathways are activated, resulting in "browning" phenotype, with a smaller increases in body weight under high-fat diet, smaller fat deposits, increased ß-oxidation of fatty acids (FAO) and oxygen consumption. Results reported here suggest that PDE3B and/or its downstream signaling partners might be important regulators of energy metabolism in adipose tissue, and potential therapeutic targets for treating obesity, diabetes and their associated metabolic disorders.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Branco/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/deficiência , Transdução de Sinais , Células 3T3-L1 , Adipócitos/metabolismo , Animais , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Metabolismo Energético , Ativação Enzimática , Epididimo/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Masculino , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Obesidade/metabolismo , Obesidade/prevenção & controle , Biogênese de Organelas , Fenótipo , Termogênese , Aumento de Peso
16.
Biochem J ; 473(22): 4205-4225, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27647936

RESUMO

Oxidative stress plays a pivotal role in pathogenesis of cardiovascular diseases and diabetes; however, the roles of protein kinase A (PKA) and human phosphodiesterase 3A (hPDE3A) remain unknown. Here, we show that yeast expressing wild-type (WT) hPDE3A or K13R hPDE3A (putative ubiquitinylation site mutant) exhibited resistance or sensitivity to exogenous hydrogen peroxide (H2O2), respectively. H2O2-stimulated ROS production was markedly increased in yeast expressing K13R hPDE3A (Oxidative stress Sensitive 1, OxiS1), compared with yeast expressing WT hPDE3A (Oxidative stress Resistant 1, OxiR1). In OxiR1, YAP1 and YAP1-dependent antioxidant genes were up-regulated, accompanied by a reduction in thioredoxin peroxidase. In OxiS1, expression of YAP1 and YAP1-dependent genes was impaired, and the thioredoxin system malfunctioned. H2O2 increased cyclic adenosine monophosphate (cAMP)-hydrolyzing activity of WT hPDE3A, but not K13R hPDE3A, through PKA-dependent phosphorylation of hPDE3A, which was correlated with its ubiquitinylation. The changes in antioxidant gene expression did not directly correlate with differences in cAMP-PKA signaling. Despite differences in their capacities to hydrolyze cAMP, total cAMP levels among OxiR1, OxiS1, and mock were similar; PKA activity, however, was lower in OxiS1 than in OxiR1 or mock. During exposure to H2O2, however, Sch9p activity, a target of Rapamycin complex 1-regulated Rps6 kinase and negative-regulator of PKA, was rapidly reduced in OxiR1, and Tpk1p, a PKA catalytic subunit, was diffusely spread throughout the cytosol, with PKA activation. In OxiS1, Sch9p activity was unchanged during exposure to H2O2, consistent with reduced activation of PKA. These results suggest that, during oxidative stress, TOR-Sch9 signaling might regulate PKA activity, and that post-translational modifications of hPDE3A are critical in its regulation of cellular recovery from oxidative stress.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Saccharomyces cerevisiae/enzimologia , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/genética , Ativação Enzimática/efeitos dos fármacos , Citometria de Fluxo , Humanos , Peróxido de Hidrogênio/farmacologia , Imunoprecipitação , Microscopia de Fluorescência , Modelos Biológicos , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
17.
Sci Rep ; 6: 28056, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27321128

RESUMO

Activation of inflammation in white adipose tissue (WAT), includes infiltration/expansion of WAT macrophages, contributes pathogenesis of obesity, insulin resistance, and metabolic syndrome. The inflammasome comprises an intracellular sensor (NLR), caspase-1 and the adaptor ASC. Inflammasome activation leads to maturation of caspase-1 and processing of IL1ß, contributing to many metabolic disorders and directing adipocytes to a more insulin-resistant phenotype. Ablation of PDE3B in WAT prevents inflammasome activation by reducing expression of NLRP3, caspase-1, ASC, AIM2, TNFα, IL1ß and proinflammatory genes. Following IP injection of lipopolysaccharide (LPS), serum levels of IL1ß and TNFα were reduced in PDE3B(-/-)mice compared to WT. Activation of signaling cascades, which mediate inflammasome responses, were modulated in PDE3B(-/-)mice WAT, including smad, NFAT, NFkB, and MAP kinases. Moreover, expression of chemokine CCL2, MCP-1 and its receptor CCR2, which play an important role in macrophage chemotaxis, were reduced in WAT of PDE3B(-/-)mice. In addition, atherosclerotic plaque formation was significantly reduced in the aorta of apoE(-/-)/PDE3B(-/-)and LDL-R(-/-)/PDE3B(-/-)mice compared to apoE(-/-)and LDL-R(-/-)mice, respectively. Obesity-induced changes in serum-cholesterol were blocked in PDE3B(-/-)mice. Collectively, these data establish a role for PDE3B in modulating inflammatory response, which may contribute to a reduced inflammatory state in adipose tissue.


Assuntos
Tecido Adiposo Branco/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Aorta/metabolismo , Aorta/patologia , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Caspase 1/genética , Caspase 1/metabolismo , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/deficiência , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo/efeitos dos fármacos , Insulina/metabolismo , Interleucina-1beta/sangue , Interleucina-1beta/metabolismo , Macrófagos/citologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Receptores CCR2/genética , Receptores CCR2/metabolismo , Receptores de LDL/deficiência , Receptores de LDL/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/metabolismo
18.
J Clin Diagn Res ; 9(5): EC01-3, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26155480

RESUMO

BACKGROUND: Abdominal tuberculosis (TB) is the sixth most common form of extra-pulmonary site of infection after lymphatic, genitourinary, bone and joint, miliary and meningeal TB with a rising incidence in recent years. TB can affect any part of the gastro-intestinal (GI) tract including anus, peritoneum and hepato-biliary system. The clinical manifestations of abdominal tuberculosis are non-specific and mimic various GI disorders and cause delay in diagnosis and management. AIM: To evaluate the various clinical, radiological and microbiological findings of abdominal tuberculosis and to define the role of histopathological examination in establishing the diagnosis in resource poor settings and to analyze the compliance and response to anti-tubercular treatment. MATERIALS AND METHODS: A five year retrospective study (January 2010 to December 2014) was done in a tertiary teaching hospital in Northern India and all the cases diagnosed as abdominal tuberculosis during the study period, were included. The relevant clinical informations, laboratory results, microbiological and radiological investigations were recorded. Histopathological examination of all the resected / excised specimens was done and Ziehl-Neelsen (ZN) staining to detect the tubercular bacilli and Periodic acid-Schiff (PAS) stain to rule out fungal infection was done in all the cases. RESULTS: Out of 48 cases with abdominal tuberculosis, the average age of presentation was 27.4 years with a slight male predominance (Male:Female=1.4:1). Abdominal pain (100%) was the most common presenting symptom followed by anorexia (98%), fever (88%) and intestinal obstruction (88%). The ileum was the most common site of involvement. All the 45 resected / excised tissue specimens (34 cases of intestinal resection and 11 cases of intesinal, omental and lymph nodes biopsies) showed epithelioid granulomas along with necrosis (in 38 cases) and Langhans giant cells (in 42 cases). Acid Fast Bacilli (AFB) positivity was seen in 5 tissue specimens only. All patients were put on anti-tubercular treatment and majority showed good response to therapy. CONCLUSION: Abdominal tuberculosis should be considered as a differential diagnosis in patients with vague GI symptoms. Study of histopathological findings can aid in the diagnosis in the settings where advanced molecular methods of diagnosis are not available, leading to early diagnosis and management.

19.
Mol Cell Biol ; 35(16): 2752-60, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26031333

RESUMO

Inhibition of adipocyte lipolysis by insulin is important for whole-body energy homeostasis; its disruption has been implicated as contributing to the development of insulin resistance and type 2 diabetes mellitus. The main target of the antilipolytic action of insulin is believed to be phosphodiesterase 3B (PDE3B), whose phosphorylation by Akt leads to accelerated degradation of the prolipolytic second messenger cyclic AMP (cAMP). To test this hypothesis genetically, brown adipocytes lacking PDE3B were examined for their regulation of lipolysis. In Pde3b knockout (KO) adipocytes, insulin was unable to suppress ß-adrenergic receptor-stimulated glycerol release. Reexpressing wild-type PDE3B in KO adipocytes fully rescued the action of insulin against lipolysis. Surprisingly, a mutant form of PDE3B that ablates the major Akt phosphorylation site, murine S273, also restored the ability of insulin to suppress lipolysis. Taken together, these data suggest that phosphorylation of PDE3B by Akt is not required for insulin to suppress adipocyte lipolysis.


Assuntos
Adipócitos Marrons/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Insulina/metabolismo , Lipólise , Células 3T3-L1 , Animais , Células Cultivadas , AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/genética , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Técnicas de Inativação de Genes , Glicerol/metabolismo , Homeostase , Resistência à Insulina , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo
20.
Proc Natl Acad Sci U S A ; 112(17): E2253-62, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25877153

RESUMO

Although inhibition of cyclic nucleotide phosphodiesterase type 3 (PDE3) has been reported to protect rodent heart against ischemia/reperfusion (I/R) injury, neither the specific PDE3 isoform involved nor the underlying mechanisms have been identified. Targeted disruption of PDE3 subfamily B (PDE3B), but not of PDE3 subfamily A (PDE3A), protected mouse heart from I/R injury in vivo and in vitro, with reduced infarct size and improved cardiac function. The cardioprotective effect in PDE3B(-/-) heart was reversed by blocking cAMP-dependent PKA and by paxilline, an inhibitor of mitochondrial calcium-activated K channels, the opening of which is potentiated by cAMP/PKA signaling. Compared with WT mitochondria, PDE3B(-/-) mitochondria were enriched in antiapoptotic Bcl-2, produced less reactive oxygen species, and more frequently contacted transverse tubules where PDE3B was localized with caveolin-3. Moreover, a PDE3B(-/-) mitochondrial fraction containing connexin-43 and caveolin-3 was more resistant to Ca(2+)-induced opening of the mitochondrial permeability transition pore. Proteomics analyses indicated that PDE3B(-/-) heart mitochondria fractions were enriched in buoyant ischemia-induced caveolin-3-enriched fractions (ICEFs) containing cardioprotective proteins. Accumulation of proteins into ICEFs was PKA dependent and was achieved by ischemic preconditioning or treatment of WT heart with the PDE3 inhibitor cilostamide. Taken together, these findings indicate that PDE3B deletion confers cardioprotective effects because of cAMP/PKA-induced preconditioning, which is associated with the accumulation of proteins with cardioprotective function in ICEFs. To our knowledge, our study is the first to define a role for PDE3B in cardioprotection against I/R injury and suggests PDE3B as a target for cardiovascular therapies.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/deficiência , Traumatismo por Reperfusão Miocárdica , Miocárdio/enzimologia , Animais , Caveolina 3/genética , Caveolina 3/metabolismo , Conexina 43/genética , Conexina 43/metabolismo , AMP Cíclico/genética , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias Cardíacas/genética , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/farmacologia , Poro de Transição de Permeabilidade Mitocondrial , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/enzimologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/patologia , Inibidores de Fosfodiesterase/farmacologia , Quinolonas/farmacologia
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