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1.
FEBS J ; 291(2): 376-391, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37845743

RESUMO

Platelet activation and related cardiovascular complications are the hallmarks of type 2 diabetes (T2D). We investigated the mechanism of platelet activation in T2D using MS-based identification of differentially expressed platelet proteins with a focus on glycosylated forms. Glycosylation is considered one of the common post-translational modifications in T2D, and N/O-linked glycosylation of glycoproteins (GPs)/integrins is known to play crucial roles in platelet activation. Our platelet proteome data revealed elevated levels of GPs GPIbα, GPIIbIIIa, GPIV (CD36), GPV and integrins in T2D patients. T2D platelets had elevated N-linked glycosylation of CD36 at asparagine (Asn)408,417 . Enrichment analysis revealed a close association of glycosylated CD36 with thrombospondin-1, fibrinogen and SERPINA1 in T2D platelets. The glycosylation of CD36 has previously been reported to increase cellular uptake of long-chain fatty acids. Our in silico molecular docking data also showed a favorable binding of cholesterol with glycosylated Asn417 CD36 compared to the non-glycosylated form. We further investigated the CD36:LDL cholesterol axis in T2D. Elevated levels of oxidized-low density lipoprotein (oxLDL) were found to cause significant platelet activation via CD36-mediated stimulation of Lyn-JNK signaling. Sulfo-N-succinimidyl oleate, an inhibitor of CD36, effectively inhibited oxLDL-mediated platelet activation and adhesion in vitro. Our study suggests increased glycosylation of CD36 in T2D platelets as a potential route for oxLDL-mediated platelet activation. The oxLDL:CD36 axis may thus be exploited as a prospective target to develop therapeutics against thrombosis in T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Glicosilação , Simulação de Acoplamento Molecular , Ativação Plaquetária/fisiologia , Lipoproteínas LDL/farmacologia , Fatores de Risco , Integrinas/metabolismo
2.
J Thromb Haemost ; 22(3): 818-833, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38029855

RESUMO

BACKGROUND: Activated platelets secrete platelet factor 4 (PF4), which contributes to viral pathogenesis. Recently, we reported the proviral role of PF4 in replication of closely related flaviviruses, Japanese encephalitis virus (JEV) and dengue virus (DENV). OBJECTIVES: This study aimed to investigate the detailed mechanism of PF4-mediated virus replication. METHODS: PF4-/- or wild-type (WT) mice were infected with JEV, and host defense mechanisms, including autophagic/interferon (IFN) responses, were assessed. WT mice were pretreated with the CXCR3 antagonist AMG487 that inhibits PF4:CXCR3 pathway. This pathway was tested in PF4-/- monocytes infected with DENV or in monocytes isolated from patients with DENV infection. RESULTS: PF4-/- mice infected with JEV showed reduced viral load and improved brain inflammation and survival. PF4-/- mice synthesized more IFN-α/ß with higher expression of phosphorylated IRF3 in the brain. PF4 treatment decreased IRF-3/7/9 and IFN-α/ß expression and suppressed autophagic LC3-II flux and lysosomal degradation of viral proteins in JEV-infected cells. PF4 increased the expression of P-mTOR, P-p38, and P-ULK1Ser757 and decreased expression of LC3-II. Decreased autophagosome-lysosome fusion in turn promoted DENV2 replication. The above processes were reversed by AMG487. Uninfected PF4-/- monocytes showed elevated LC3-II and autophagosome-lysosome fusion. Microglia of JEV-infected PF4-/- mice exhibited elevated LC3-II inversely related to viral load. Similarly, monocytes from PF4-/- mice showed reduced infection by DENV2. In patients with DENV infection, higher plasma PF4 and viral load were inversely correlated with LC3-II, LAMP-1, and lysosomal degradation of DENV-NS1 in monocytes during the febrile phase. CONCLUSION: These studies suggest that PF4 deficiency or inhibition of the PF4:CXCR3 pathway prevents JEV and DENV infection. The studies also highlight the PF4:CXCR3 axis as a potential target to develop treatment regimens against flaviviruses.


Assuntos
Dengue , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Pirimidinonas , Animais , Humanos , Camundongos , Acetamidas , Dengue/tratamento farmacológico , Dengue/metabolismo , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/tratamento farmacológico , Fatores Imunológicos , Fator Plaquetário 4 , Receptores CXCR3
3.
IUBMB Life ; 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38063433

RESUMO

Diabetes, a chronic metabolic disorder disrupting blood sugar regulation, has emerged as a prominent silent pandemic. Uncontrolled diabetes predisposes an individual to develop fatal complications like cardiovascular disorders, kidney damage, and neuropathies and aggravates the severity of treatable infections. Escalating cases of Type 1 and Type 2 diabetes correlate with a global upswing in diabetes-linked mortality. As a growing global concern with limited preventive interventions, diabetes necessitates extensive research to mitigate its healthcare burden and assist ailing patients. An altered immune system exacerbated by chronic hyperinflammation heightens the susceptibility of diabetic individuals to microbial infections, including notable viruses like SARS-CoV-2, dengue, and influenza. Given such a scenario, we scrutinized the literature and compiled molecular pathways and signaling cascades related to immune compartments in diabetics that escalate the severity associated with the above-mentioned viral infections in them as compared to healthy individuals. The pathogenesis of these viral infections that trigger diabetes compromises both innate and adaptive immune functions and pre-existing diabetes also leads to heightened disease severity. Lastly, this review succinctly outlines available treatments for diabetics, which may hold promise as preventive or supportive measures to effectively combat these viral infections in the former.

4.
mBio ; : e0182323, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37982662

RESUMO

IMPORTANCE: Severe dengue manifestations caused by the dengue virus are a global health problem. Studies suggest that severe dengue disease depends on uncontrolled immune cell activation, and excessive inflammation adds to the pathogenesis of severe dengue disease. Therefore, it is important to understand the process that triggers the uncontrolled activation of the immune cells. The change in immune response in mild to severe dengue may be due to direct virus-to-cell interaction or it could be a contact-independent process through the extracellular vesicles (EVs) released from infected cells. The importance of circulating EVs in the context of dengue virus infection and pathogenesis remains unexplored. Therefore, understanding the possible biological function of circulating EVs may help to delineate the role of EVs in the progression of disease. Our present study highlights that EVs from plasma of severe dengue patients can have immunosuppressive properties on CD4+ T cells which may contribute to T cell suppression and may contribute to dengue disease progression.

5.
Cytokine ; 172: 156380, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37812996

RESUMO

The endoplasmic reticulum (ER) is crucial for maintaining cellular homeostasis, and synthesis and folding of proteins and lipids. The ER is sensitive to stresses including viral infection that perturb the intracellular energy level and redox state, and accumulating unfolded/misfolded proteins. Viruses including Japanese encephalitis virus (JEV) activates unfolded protein response (UPR) causing ER stress in host immune cells and promotes inflammation and apoptotic cell death. The chemokine receptor CXCR3 has been reported to play important role in the accumulation of inflammatory immune cells and neuronal cell death in several disease conditions. Recently we described the involvement of CXCR3 in regulating inflammation and JEV infection in mice brain. Supplementation with a CXCR3 antagonist AMG487 significantly reduced JEV infection in the mice brain in conjunction with the downregulation of UPR pathway via PERK:eIF2α:CHOP, and decreased mitochondrial ROS generation, inflammation and apoptotic cell death. Alongside, AMG487 treatment improved interferon (IFN)-α/ß synthesis in JEV-infected mice brain. Thus, suggesting a potential therapeutic role of CXCR3 antagonist against JEV infection.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Animais , Camundongos , Encefalite Japonesa/metabolismo , Estresse do Retículo Endoplasmático , Inflamação/tratamento farmacológico , Encéfalo/metabolismo
6.
Clin Exp Immunol ; 214(2): 197-208, 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-37498307

RESUMO

The interplay between platelets and leukocytes contributes to the pathogenesis of inflammation, thrombosis, and cardiovascular diseases (CVDs) in type 2 diabetes (T2D). Our recent studies described alpha-ketoglutarate (αKG), a Krebs cycle intermediate metabolite as an inhibitor to platelets and leukocytes activation by suppressing phosphorylated-Akt (pAkt) through augmentation of prolyl hydroxylase-2 (PHD2). Dietary supplementation with a pharmacological concentration of αKG significantly inhibited lung inflammation in mice with either SARS-CoV-2 infection or exposed to hypoxia treatment. We therefore investigated if αKG supplementation could suppress hyperactivation of these blood cells and reduce thromboinflammatory complications in T2D. Our study describes that dietary supplementation with αKG (8 mg/100 g body wt. daily) for 7 days significantly reduced the activation of platelets and leukocytes (neutrophils and monocytes), and accumulation of IL1ß, TNFα, and IL6 in peripheral blood of T2D mice. αKG also reduced the infiltration of platelets and leukocytes, and accumulation of inflammatory cytokines in lungs by suppressing pAkt and pP65 signaling. In a cross-sectional investigation, our study also described the elevated platelet-leukocyte aggregates and pro-inflammatory cytokines in circulation of T2D patients. T2D platelets and leukocytes showed an increased aggregation and thrombus formation in vitro. Interestingly, a pre-incubation of T2D blood samples with octyl αKG significantly suppressed the activation of these blood cells and ameliorated aggregate/thrombus formation in vitro. Thus, suggesting a potential therapeutic role of αKG against inflammation, thrombosis, and CVDs in T2D.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Trombose , Humanos , Camundongos , Animais , Ácidos Cetoglutáricos/metabolismo , Estudos Transversais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Ativação Plaquetária , Inflamação/metabolismo , Leucócitos/patologia , Plaquetas/patologia , Trombose/tratamento farmacológico , Trombose/etiologia , Doenças Cardiovasculares/patologia , Citocinas/metabolismo , Suplementos Nutricionais
7.
Biomater Adv ; 143: 213184, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36371969

RESUMO

Herein, we report redox responsive, colon cancer targeting poly(allylamine) (PA)/eudragit S-100 (EU) nanoparticles (PAEU NPs) (≈59 nm). These disulfide crosslinked PAEU NPs are developed via air oxidation of thiolated PA and thiolated EU, eliminating the need of any external crosslinking agent for dual drug delivery. PAEU NPs can effectively encapsulate both hydrophilic doxorubicin (DOX) and hydrophobic curcumin (Cur) drug with ≈85 % and ≈97 % encapsulation efficiency respectively. Here, the combination of drugs having different anticancer mechanism offers the possibility of developing nanosystem with enhanced anticancer efficacy. The developed PAEU NPs show good colloidal stability and low drug release under physiological conditions, while high DOX (≈98 %) and Cur (≈93 %) release is observed in reducing environment (10 mM GSH). Further, DOX and Cur loaded PAEU NPs exhibit higher cancer cell killing efficiency as compared to individual free drugs. In vivo biodistribution studies with Balb/C mice display the retention of PAEU NPs in the colon region up to 24 h presenting the developed approach as an efficient way for colorectal cancer therapy.


Assuntos
Alilamina , Neoplasias Colorretais , Curcumina , Nanopartículas , Camundongos , Animais , Distribuição Tecidual , Doxorrubicina/uso terapêutico , Oxirredução , Neoplasias Colorretais/tratamento farmacológico
9.
Biomater Adv ; 136: 212796, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35929295

RESUMO

Inflammatory Bowel (IBD) is an umbrella term which includes Crohn's Disease (CD) and Ulcerative Colitis (UC). At present, therapies available for management of the UC includes, corticosteroid, immuno-suppressants and antibiotics are used for mild to moderate UC conditions which can cause nephrotoxicity, hepatotoxicity and cardiotoxicity. Hence, a novel therapeutic candidate having potent anti-inflammatory effect is urgently warranted for the management of UC. Melatonin has emerged as a potent anti-inflammatory agent. However, poor solubility limits its therapeutic potential. Therefore, colon targeted Eudragit-S-100 coated chitosan nanoparticles have been demonstrated to improve melatonin therapeutic efficacy. It was found that melatonin loaded chitosan and colon targeted chitosan nanoparticles had promising anti-inflammatory efficacy in terms of NO scavenging activity in an in-vitro LPS challenged macrophages. Also, colon targeted oral chitosan nano-formulation exhibited remarkable protection in an in vivo UC mice model by improving gross pathological parameters, histo-architectural protection, goblet cell depletion, and immune cells infiltration which can be extrapolated to clinical studies.


Assuntos
Quitosana , Colite Ulcerativa , Doenças Inflamatórias Intestinais , Melatonina , Animais , Anti-Inflamatórios/farmacologia , Quitosana/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Doenças Inflamatórias Intestinais/induzido quimicamente , Melatonina/farmacologia , Camundongos
10.
Front Cell Dev Biol ; 10: 834016, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35386203

RESUMO

Prion peptide (PrP) misfolds to infectious scrapie isoform, the ß pleat-rich insoluble fibrils responsible for neurodegeneration and fatal conformational diseases in humans. The amino acid sequence 106-126 from prion proteins, PrP(106-126), is highly amyloidogenic and implicated in prion-induced pathologies. Here, we report a novel interaction between PrP(106-126) and the thrombogenic plasma protein fibrinogen that can lead to mitigation of prion-mediated pro-thrombotic responses in human platelets as well as significant decline in neuronal toxicity. Thus, prior exposure to fibrinogen-restrained PrP-induced rise in cytosolic calcium, calpain activation, and shedding of extracellular vesicles in platelets while it, too, averted cytotoxicity of neuronal cells triggered by prion peptide. Interestingly, PrP was found to accelerate fibrin-rich clot formation, which was resistant to plasmin-mediated fibrinolysis, consistent with enhanced thrombus stability provoked by PrP. We propose that PrP-fibrinogen interaction can be clinically exploited further for prevention and management of infectious prion related disorders. Small molecules or peptides mimicking PrP-binding sites on fibrinogen can potentially mitigate PrP-induced cellular toxicity while also preventing the negative impact of PrP on fibrin clot formation and lysis.

11.
Blood Cells Mol Dis ; 94: 102653, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35180460

RESUMO

Abnormal coagulation dynamics, including disseminated intravascular coagulopathy, pulmonary embolism, venous thromboembolism and risk of thrombosis are often associated with the severity of COVID-19. However, very little is known about the contribution of platelets in above pathogenesis. In order to decipher the pathophysiology of thrombophilia in COVID-19, we recruited severely ill patients from ICU, based on the above symptoms and higher D-dimer levels, and compared these parameters with their asymptomatic counterparts. Elevated levels of platelet-derived microparticles and platelet-leukocyte aggregates suggested the hyperactivation of platelets in ICU patients. Strikingly, platelet transcriptome analysis showed a greater association of IL-6 and TNF signalling pathways in ICU patients along with higher plasma levels of IL-6 and TNFα. In addition, upregulation of pathways like blood coagulation and hemostasis, as well as inflammation coexisted in platelets of these patients. Further, the increment of necrotic pathway and ROS-metabolic processes in platelets was suggestive of its procoagulant phenotype in ICU patients. This study suggests that higher plasma IL-6 and TNFα may trigger platelet activation and coagulation, and in turn aggravate thrombosis and hypercoagulation in severe COVID-19 patients. Therefore, the elevated IL-6 and TNFα, may serve as potential risk factors for platelet activation and thrombophilia in these patients.


Assuntos
COVID-19 , Micropartículas Derivadas de Células , Trombofilia , Plaquetas/metabolismo , COVID-19/complicações , Micropartículas Derivadas de Células/metabolismo , Citocinas/metabolismo , Humanos , SARS-CoV-2 , Trombofilia/complicações , Regulação para Cima
12.
Virus Res ; 309: 198668, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34971702

RESUMO

Dengue virus (DENV) is most prevalent arthropod-borne human pathogen belongs to Flaviviridae family causes thousands of deaths annually. HMGB1 is highly conserved, ubiquitously expressed, non-histone nuclear protein which plays important role in diseases like metabolic disorders, cancer, and viral infections. However, the importance of HMGB1 in DENV infection is understudied. In this study, we observed that DENV-2 induces cytoplasmic translocation and secretion of HMGB1. Interestingly, inhibition of HMGB1 secretion by ethyl pyruvate (EP) enhanced viral propagation while silencing of HMGB1 resulted in abrogated viral replication in DENV-2 infected A549 cells. RNA-Electrophoretic mobility shift assay and immunoprecipitation showed that HMGB1 interacts with 5'-3' UTRs of DENV-2 genome. This interaction further stimulates production of proinflammatory cytokines like TNF-α, IL-6 and IL-1ß which have been implicated in pathogenesis of severe DENV disease. Together, our finding suggests that DENV-2 modulates HMGB1 translocation and HMGB1-DENV-2 UTRs RNA interaction further induces proinflammatory cytokines production in A549 cells. This study discloses HMGB1 as an important host factor contributing to disease pathogenesis and hence can be targeted as an alternative approach for antiviral development against DENV virus infection.


Assuntos
Vírus da Dengue , Dengue , Proteína HMGB1 , Regiões 5' não Traduzidas , Vírus da Dengue/fisiologia , Genoma Viral , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Humanos , Replicação Viral
13.
EBioMedicine ; 73: 103672, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34740102

RESUMO

BACKGROUND: Phospho-Akt1 (pAkt1) undergoes prolyl hydroxylation at Pro125 and Pro313 by the prolyl hydroxylase-2 (PHD2) in a reaction decarboxylating α-ketoglutarate (αKG). We investigated whether the αKG supplementation could inhibit Akt-mediated activation of platelets and monocytes, in vitro as well as in vivo, by augmenting PHD2 activity. METHODS: We treated platelets or monocytes isolated from healthy individuals with αKG in presence of agonists in vitro and assessed the signalling molecules including pAkt1. We supplemented mice with dietary αKG and estimated the functional responses of platelets and monocytes ex vivo. Further, we investigated the impact of dietary αKG on inflammation and thrombosis in lungs of mice either treated with thrombosis-inducing agent carrageenan or infected with SARS-CoV-2. FINDINGS: Octyl αKG supplementation to platelets promoted PHD2 activity through elevated intracellular αKG to succinate ratio, and reduced aggregation in vitro by suppressing pAkt1(Thr308). Augmented PHD2 activity was confirmed by increased hydroxylated-proline and enhanced binding of PHD2 to pAkt in αKG-treated platelets. Contrastingly, inhibitors of PHD2 significantly increased pAkt1 in platelets. Octyl-αKG followed similar mechanism in monocytes to inhibit cytokine secretion in vitro. Our data also describe a suppressed pAkt1 and reduced activation of platelets and leukocytes ex vivo from mice supplemented with dietary αKG, unaccompanied by alteration in their number. Dietary αKG significantly reduced clot formation and leukocyte accumulation in various organs including lungs of mice treated with thrombosis-inducing agent carrageenan. Importantly, in SARS-CoV-2 infected hamsters, we observed a significant rescue effect of dietary αKG on inflamed lungs with significantly reduced leukocyte accumulation, clot formation and viral load alongside down-modulation of pAkt in the lung of the infected animals. INTERPRETATION: Our study suggests that dietary αKG supplementation prevents Akt-driven maladies such as thrombosis and inflammation and rescues pathology of COVID19-infected lungs. FUNDING: Study was funded by the Department of Biotechnology (DBT), Govt. of India (grants: BT/PR22881 and BT/PR22985); and the Science and Engineering Research Board, Govt. of India (CRG/000092).


Assuntos
Ácidos Cetoglutáricos/uso terapêutico , Prolil Hidroxilases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trombose/prevenção & controle , Animais , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , COVID-19/patologia , COVID-19/prevenção & controle , COVID-19/veterinária , COVID-19/virologia , Cricetinae , Suplementos Nutricionais , Regulação para Baixo/efeitos dos fármacos , Humanos , Ácidos Cetoglutáricos/farmacologia , Pulmão/metabolismo , Pulmão/patologia , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fosforilação , Agregação Plaquetária/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/fisiologia , Trombose/induzido quimicamente , Trombose/patologia , Trombose/veterinária
14.
Mol Aspects Med ; 81: 101000, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34294412

RESUMO

History of pandemics is dominated by viral infections and specifically respiratory viral diseases like influenza and COVID-19. Lower respiratory tract infection is the fourth leading cause of death worldwide. Crosstalk between resultant inflammation and hypoxic microenvironment may impair ventilatory response of lungs. This reduces arterial partial pressure of oxygen, termed as hypoxemia, which is observed in a section of patients with respiratory virus infections including SARS-CoV-2 (COVID-19). In this review, we describe the interplay between inflammation and hypoxic microenvironment in respiratory viral infection and its contribution to disease pathogenesis.


Assuntos
COVID-19 , Humanos , Hipóxia , Inflamação , Pandemias , SARS-CoV-2
15.
EBioMedicine ; 68: 103418, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34102396

RESUMO

BACKGROUND: We have previously described an evolutionarily selected Tibetan prolyl hydroxylase-2 (PHD2D4E;C127S) variant that degrades the hypoxia-inducible factor (HIFα) more efficiently and protects these highlanders from hypoxia-triggered elevation in haemoglobin concentration. High altitude is known to cause acute mountain sickness (AMS) and high-altitude pulmonary edema (HAPE) in a section of rapidly ascending non-acclimatised lowlanders. These morbidities are often accompanied by inflammatory response and exposure to hypobaric hypoxia is presumed to be the principal causative agent. We have investigated whether PHD2D4E;C127S variant is associated with prevention of hypoxia-mediated inflammatory milieu in Tibetan highlanders and therefore identify a potential target to regulate inflammation. METHODS: We genotyped the Tibetans using DNA isolated from whole blood. Thereafter immunophenotying was performed on PBMCs from homozygous PHD2D4E;C127S and PHD2WT individuals using flow cytometry. RNA isolated from these individuals was used to evaluate the peripheral level of important transcripts associated with immune as well as hypoxia response employing the nCounter technology. The ex-vivo findings were validated by generating monocytic cell lines (U937 cell line) expressing PHD2D4E;C127S and PHD2WT variants post depletion of endogenous PHD2. We had also collected whole blood samples from healthy travellers and travellers afflicted with AMS and HAPE to evaluate the significance of our ex-vivo and in vitro findings. Hereafter, we also attempted to resolve hypoxia-triggered inflammation in vitro as well as in vivo by augmenting the function of PHD2 using alpha-ketoglutarate (αKG), a co-factor of PHD2. FINDINGS: We report that homozygous PHD2D4E;C127S highlanders harbour less inflammatory and patrolling monocytes in circulation as compared to Tibetan PHD2WT highlanders. In response to in vitro hypoxia, secretion of IL6 and IL1ß from PHD2D4E;C127S monocytes, and their chemotactic response compared to the PHD2WT are compromised, corresponding to the down-modulated expression of related signalling molecules RELA, JUN, STAT1, ATF2 and CXCR4. We verified these functional outcomes in monocytic U937 cell line engineered to express PHD2D4E;C127S and confirmed the down-modulation of the signalling molecules at protein level under hypoxia. In contrast, non-Tibetan sojourners with AMS and HAPE at high altitude (3,600 m above sea level) displayed significant increase in these inflammatory parameters. Our data henceforth underline the role of gain-of-function of PHD2 as the rate limiting factor to harness hyper-activation of monocytes in hypoxic environment. Therefore upon pre-treatment with αKG, we observed diminished inflammatory response of monocytes in vitro and reduction in leukocyte infiltration to the lungs in mice exposed to normobaric hypoxia. INTERPRETATION: Our report suggests that gain-of-function PHD2 D4E;C127S variant can therefore protect against inflammation elicited by hypobaric hypoxia. Augmentation of PHD2 activity therefore may be an important method to alleviate inflammatory response to inspired hypoxia. FUNDING: This study is supported by the Department of Biotechnology, Government of India.


Assuntos
Doença da Altitude/prevenção & controle , Mutação com Ganho de Função , Hipertensão Pulmonar/prevenção & controle , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Ácidos Cetoglutáricos/efeitos adversos , Adulto , Doença da Altitude/induzido quimicamente , Doença da Altitude/genética , Animais , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Humanos , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/genética , Imunofenotipagem , Masculino , Camundongos , Viagem , Células U937 , Adulto Jovem
16.
Virus Res ; 300: 198436, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33901593

RESUMO

Dengue fever is a significant mosquito-borne viral disease that affects millions of people every year. As a co-existing mechanism, DENV has evolved to evade elimination by the host antiviral immune system. DENV is reported to modulate host interferon response either by attenuating the factors that mediate interferon response like STAT1 and STAT2 or inhibiting the activation of STAT1 or by STAT2 degradation. Through this study we aim to understand how DENV modulates STAT3 mediated interferon response to its own advantage. We employed various techniques like Western blot, Confocal microscopy, RT-PCR to show that STAT3 acts as a pro-viral factor for DV-2 propagation. As per result of the present study STAT3 is upregulated as well as activated by phosphorylation in DV-2 infected A549 cells. Additionally, STAT3 knockdown led to a significant decrease in expression of viral proteins as well as viral replication. We show that DV-2 strategically tweaks STAT3 which is a negative regulator of Type I IFN signaling, in order to evade host Type I and Type III interferon response by upregulating its expression and activation. Our results demonstrate the proviral role of STAT3 for DV-2 propagation which is correlated to activation by tyrosine phosphorylation. Furthermore, since STAT3 is critical factor for DV-2 propagation, its modulation can facilitate targeted development of antivirals against Dengue.


Assuntos
Vírus da Dengue , Dengue , Fator de Transcrição STAT3 , Animais , Antivirais/farmacologia , Dengue/genética , Vírus da Dengue/fisiologia , Humanos , Interferons/metabolismo , Provírus/fisiologia , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT2/genética , Fator de Transcrição STAT3/genética
17.
Front Cell Infect Microbiol ; 10: 561366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33102253

RESUMO

Platelets are anucleated blood cells derived from bone marrow megakaryocytes and play a crucial role in hemostasis and thrombosis. Platelets contain specialized storage organelles, called alpha-granules, contents of which are rich in cytokines such as C-X-C Motif Chemokine Ligand (CXCL) 1/4/7, (C-C motif) ligand (CCL) 5/3, CXCL8 (also called as interleukin 8, IL-8), and transforming growth factor ß (TGF-ß). Activation of platelets lead to degranulation and release of contents into the plasma. Platelet activation is a common event in many viral infections including human immunodeficiency virus (HIV), H1N1 influenza, Hepatitis C virus (HCV), Ebola virus (EBV), and Dengue virus (DENV). The cytokines CXCL8, CCL5 (also known as Regulated on Activation, Normal T Expressed and Secreted, RANTES), tumor necrosis factor α (TNF-α), CXCL1/5 and CCL3 released, promote development of a pro-inflammatory state along with the recruitment of other immune cells to the site of infection. Platelets also interact with Monocytes and Neutrophils and facilitate their activation to release different cytokines which further enhances inflammation. Upon activation, platelets also secrete factors such as CXCL4 (also known as platelet factor, PF4), CCL5 and fibrinopeptides which are critical regulators of replication and propagation of several viruses in the host. Studies suggest that CXCL4 can both inhibit as well as enhance HIV1 infection. Data from our lab show that CXCL4 inhibits interferon (IFN) pathway and promotes DENV replication in monocytes in vitro and in patients significantly. Inhibition of CXCL4 mediated signaling results in increased IFN production and suppressed DENV and JEV replication in monocytes. In this review, we discuss the role of platelets in viral disease progression with a focus on dengue infection.


Assuntos
Vírus da Dengue , Dengue , Vírus da Influenza A Subtipo H1N1 , Plaquetas , Citocinas , Humanos
18.
J Biomed Nanotechnol ; 16(4): 481-491, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32970980

RESUMO

There is continued interest in Nano Carbon Materials (NCMs) and two of these, Fullerene C60 and Graphene have received Nobel prizes. Low solubility in most solvents has been a stumbling block in their industrial use. We report here the successful synthesis of a new water soluble tri-adduct of Fullerene C60 using a two-step procedure to obtain the water soluble s-Tri-(1-aziridino-2, 3-dimethoxy-benzene-5-carboxylato-6-carboxylic acid)-H-Fullerene C60-Manganese (II) Complex ( III ). Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) and Electron Paramagnetic Resonance (EPR) studies critically helped recognize the presence of an atom of Manganese in the complex. The new complex was also characterized by Ultra violet-Visible (UV-Vis.). Fourier Transform-Infra Red (FT-IR) spectroscopy, Energy Dispersive X-ray analysis (EDAX), Scanning Electron Microscopy (SEM), Thermal Gravimetric Analysis (TGA), and powder X-ray diffraction. The new compound has been shown to possess anti-cancer activity comparable to Doxorubicin, currently the most used anti-cancer drug. This new water soluble Fullerene C60-Manganese (II) tri-adduct complex ( III ) thus holds much promise for the fields of biology, biochemistry, medicine, and materials science.


Assuntos
Fulerenos/química , Doxorrubicina/farmacologia , Manganês , Espectroscopia de Infravermelho com Transformada de Fourier , Água
19.
ACS Omega ; 5(16): 9585-9597, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32363311

RESUMO

Inositol hexakisphosphate (InsP6; phytic acid) is considered as the second messenger and plays a very important role in plants, animals, and human beings. It is the principal storage form of phosphorus in many plant tissues, especially in dry fruits, bran, and seeds. The resulting anion is a colorless species that plays a critical role in nutrition and is believed to cure many diseases. A fluoresceinated aminohexanol tethered inositol hexakisphosphate (III) had been synthesized earlier involving many complicated steps. We describe here a simple two-step synthesis of (III) and its characterization using different techniques such as matrix-assisted laser desorption ionization mass spectrometry, tandem mass spectrometry, and Fourier transform infrared, ultraviolet-visible, ultraviolet-fluorescence, 1H nuclear magnetic resonance (NMR), and two-dimensional NMR spectroscopies. The effect of (III) has been investigated in the model systems, Arabidopsis thaliana and Drosophila melanogaster. Using Schrodinger software, computational studies on the binding of (III) with the protein 2P1M (Auxin-receptor TIR1-adaptor ASK1 complex) has revealed strong binding propensity with this compound. These studies on the fluoresceinated tethered phytic acid could have far reaching implications on its efficacy for human health and treatment of diseases (cancer/tumor and glioblastoma) and for understanding phosphorous recycling in the environment, especially for plant systems.

20.
ACS Biomater Sci Eng ; 6(5): 3139-3153, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33463265

RESUMO

Epigenetically regulated therapeutic intervention of cancer is an emerging era of research in the development of a promising therapy. Epigenetic changes are intrinsically reversible and providing the driving force to drug resistance in colorectal cancer (CRC). The regulation of polycomb group (PcG) proteins, BMI1 and EZH2, and the associated CRC progression hold promises for a novel treatment regime. The present study enlightens targeted photodynamic therapy (PDT) with potential photosensitizer hypericin nanocomposite in the development of epigenetic-based CRC therapy. We have synthesized hypericin-loaded transferrin nanoformulations (HTfNPs) overcoming the compromised hydrophobicity and poor bioavailability of the placebo drug. Targeted PDT with hypericin nanocomposite-induced BMI1 degradation assisted CRC retardation. In the present study, transferrin nanoparticles were reported to control the premature release of hypericin and improve its availability with better targeting at the disease site. Targeted intracellular internalization to colon cancer cells having a differential expression of transferrin receptors, in vivo biodistribution, stability, and pharmacokinetics provide promising applications in the nanodelivery system. Indeed, in vitro anticancer efficiency, cell cycle arrest at the G0/G1 phase, and elevated reactive oxygen species (ROS) generation confirm the anticancer effect of nanoformulation. In the exploration of mechanism, nanotherapeutic intervention by activation of PP2A, Caspase3 and inhibition of BMI1, EZH2, 3Pk, NFκB was evident. An exciting outcome of this study uncovered the camouflaged role of PP2A in the regulation of BMI1. PP2A mediates the ubiquitination/degradation of BMI1, which is revealed by changes in the physical interaction of PP2A and BMI1. Our study confirms the anticancer effect of HTfNP-assisted PDT by inducing PP2A-mediated BMI1 ubiquitination/degradation demonstrating an epigenetic-driven nanotherapeutic approach in CRC treatment.


Assuntos
Neoplasias Colorretais , Nanopartículas , Fotoquimioterapia , Antracenos , Neoplasias Colorretais/tratamento farmacológico , Humanos , Perileno/análogos & derivados , Distribuição Tecidual , Transferrina
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