Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Int J Mol Sci ; 25(4)2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38396946

RESUMO

Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are gradually becoming a burden to society. The adverse effects and mortality/morbidity rates associated with these NDDs are a cause of many healthcare concerns. The pathologic alterations of NDDs are related to mitochondrial dysfunction, oxidative stress, and inflammation, which further stimulate the progression of NDDs. Recently, long non-coding RNAs (lncRNAs) have attracted ample attention as critical mediators in the pathology of NDDs. However, there is a significant gap in understanding the biological function, molecular mechanisms, and potential importance of lncRNAs in NDDs. This review documents the current research on lncRNAs and their implications in NDDs. We further summarize the potential implication of lncRNAs to serve as novel therapeutic targets and biomarkers for patients with NDDs.


Assuntos
Doença de Alzheimer , Esclerose Lateral Amiotrófica , Doenças Neurodegenerativas , Doença de Parkinson , RNA Longo não Codificante , Humanos , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , RNA Longo não Codificante/genética , Doença de Parkinson/genética , Esclerose Lateral Amiotrófica/genética
2.
Int J Mol Sci ; 22(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067896

RESUMO

Exosomes are nanoscale vesicles generated by cells for intercellular communication. Due to their composition, significant research has been conducted to transform these particles into specific delivery systems for various disease states. In this review, we discuss the common isolation and loading methods of exosomes, some of the major roles of exosomes in the tumor microenvironment, as well as discuss recent applications of exosomes as drug delivery vessels and the resulting clinical implications.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Exossomos/metabolismo , Neoplasias/terapia , Exossomos/patologia , Exossomos/fisiologia , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/fisiologia
3.
Bioorg Chem ; 82: 211-223, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30326403

RESUMO

Based on the quantitative structure-activity relationship (QSAR), some novel p-aminobenzoic acid derivatives as promising cholinesterase enzyme inhibitors were designed, synthesized, characterized and evaluated to enhance learning and memory. The in vitro enzyme kinetic study of the synthesized compounds revealed the type of inhibition on the respective acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The in vivo studies of the synthesized compounds exhibited significant reversal of cognitive deficits in the animal models of amnesia as compared to standard drug donepezil. Further, the ex vivo studies in the specific brain regions like the hippocampus, hypothalamus, and prefrontal cortex regions also exhibited AChE inhibition comparable to standard donepezil. The in silico molecular docking and dynamics simulations studies of the most potent compound 22 revealed the consensual interactions at the active site pocket of the AChE.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/uso terapêutico , Nootrópicos/uso terapêutico , para-Aminobenzoatos/uso terapêutico , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Encéfalo/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/toxicidade , Desenho de Fármacos , Feminino , Cinética , Masculino , Memória/efeitos dos fármacos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Nootrópicos/síntese química , Nootrópicos/química , Nootrópicos/toxicidade , Relação Quantitativa Estrutura-Atividade , Ratos , Semicarbazonas/síntese química , Semicarbazonas/química , Semicarbazonas/uso terapêutico , Semicarbazonas/toxicidade , para-Aminobenzoatos/síntese química , para-Aminobenzoatos/química , para-Aminobenzoatos/toxicidade
4.
Br J Cancer ; 118(4): 587-599, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29465084

RESUMO

BACKGROUND: Cancer progression and metastasis is profoundly influenced by protein kinase D1 (PKD1) and metastasis-associated protein 1 (MTA1) in addition to other pathways. However, the nature of regulatory relationship between the PKD1 and MTA1, and its resulting impact on cancer metastasis remains unknown. Here we present evidence to establish that PKD1 is an upstream regulatory kinase of MTA1. METHODS: Protein and mRNA expression of MTA1 in PKD1-overexpressing cells were determined using western blotting and reverse-transcription quantitative real-time PCR. Immunoprecipitation and proximity ligation assay (PLA) were used to determine the interaction between PKD1 and MTA1. PKD1-mediated nucleo-cytoplasmic export and polyubiquitin-dependent proteosomal degradation was determined using immunostaining. The correlation between PKD1 and MTA1 was determined using intra-tibial, subcutaneous xenograft, PTEN-knockout (PTEN-KO) and transgenic adenocarcinoma of mouse prostate (TRAMP) mouse models, as well as human cancer tissues. RESULTS: We found that MTA1 is a PKD1-interacting substrate, and that PKD1 phosphorylates MTA1, supports its nucleus-to-cytoplasmic redistribution and utilises its N-terminal and kinase domains to effectively inhibit the levels of MTA1 via polyubiquitin-dependent proteosomal degradation. PKD1-mediated downregulation of MTA1 was accompanied by a significant suppression of prostate cancer progression and metastasis in physiologically relevant spontaneous tumour models. Accordingly, progression of human prostate tumours to increased invasiveness was also accompanied by decreased and increased levels of PKD1 and MTA1, respectively. CONCLUSIONS: Overall, this study, for the first time, establishes that PKD1 is an upstream regulatory kinase of MTA1 status and its associated metastatic activity, and that the PKD1-MTA1 axis could be targeted for anti-cancer strategies.


Assuntos
Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Neoplasias da Próstata/patologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Canais de Cátion TRPP/genética , Canais de Cátion TRPP/metabolismo , Animais , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Técnicas de Inativação de Genes , Humanos , Células MCF-7 , Masculino , Camundongos , Metástase Neoplásica , Transplante de Neoplasias , PTEN Fosfo-Hidrolase/genética , Fosforilação , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Transativadores
5.
Nature ; 465(7300): 956-60, 2010 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-20559389

RESUMO

Transcription of eukaryotic messenger RNA (mRNA) encoding genes by RNA polymerase II (Pol II) is triggered by the binding of transactivating proteins to enhancer DNA, which stimulates the recruitment of general transcription factors (TFIIA, B, D, E, F, H) and Pol II on the cis-linked promoter, leading to pre-initiation complex formation and transcription. In TFIID-dependent activation pathways, this general transcription factor containing TATA-box-binding protein is first recruited on the promoter through interaction with activators and cooperates with TFIIA to form a committed pre-initiation complex. However, neither the mechanisms by which activation signals are communicated between these factors nor the structural organization of the activated pre-initiation complex are known. Here we used cryo-electron microscopy to determine the architecture of nucleoprotein complexes composed of TFIID, TFIIA, the transcriptional activator Rap1 and yeast enhancer-promoter DNA. These structures revealed the mode of binding of Rap1 and TFIIA to TFIID, as well as a reorganization of TFIIA induced by its interaction with Rap1. We propose that this change in position increases the exposure of TATA-box-binding protein within TFIID, consequently enhancing its ability to interact with the promoter. A large Rap1-dependent DNA loop forms between the activator-binding site and the proximal promoter region. This loop is topologically locked by a TFIIA-Rap1 protein bridge that folds over the DNA. These results highlight the role of TFIIA in transcriptional activation, define a molecular mechanism for enhancer-promoter communication and provide structural insights into the pathways of intramolecular communication that convey transcription activation signals through the TFIID complex.


Assuntos
Modelos Moleculares , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ligação a Telômeros/metabolismo , Fator de Transcrição TFIIA/metabolismo , Fator de Transcrição TFIID/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional , Microscopia Crioeletrônica , Nucleoproteínas/química , Nucleoproteínas/ultraestrutura , Estrutura Terciária de Proteína , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/ultraestrutura , Complexo Shelterina , Proteínas de Ligação a Telômeros/química , Proteínas de Ligação a Telômeros/ultraestrutura , Fator de Transcrição TFIIA/química , Fator de Transcrição TFIID/química , Fatores de Transcrição/química , Fatores de Transcrição/ultraestrutura
6.
J Environ Pathol Toxicol Oncol ; 43(2): 43-55, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505912

RESUMO

Gastrointestinal (GI) cancers comprise of cancers that affect the digestive system and its accessory organs. The late detection and poor prognosis of GI cancer emphasizes the importance of identifying reliable and precise biomarkers for early diagnosis and prediction of prognosis. The membrane-bound glycoprotein dipeptidyl-peptidase 4 (DPP4), also known as CD26, is ubiquitously expressed and has a wide spectrum of biological roles. The role of DPP4/CD26 in tumor progression in different types of cancers remains elusive. However, the link between DPP4 and tumor-infiltrating cells, as well as its prognostic significance in malignancies, still require further investigation. This study was intended to elucidate the correlation of DPP4 expression and survival along with prognosis, followed by its associated enriched molecular pathways and immune cell marker levels in upper GI cancers. Results demonstrated a strong correlation between increased DPP4 expression and a worse prognosis in esophageal and gastric cancer and the co-expressed common genes with DPP4 were associated with crucial molecular pathways involved in tumorigenesis. Additionally, DPP4 was shown to be significantly linked to several immune infiltrating cell marker genes, including Macrophages (M1, M2 and Tumor Associated Macrophages), neutrophils, Treg, T-cell exhaustion, Th1 and Th2. Overall, our findings suggest that DPP4 may serve as a substantial prognostic biomarker, a possible therapeutic target, as well as it can play a critical role in the regulation of immune cell invasion in patients with gastroesophageal (esophageal, gastroesophageal junction and gastric) cancer. KEY WORDS: DPP4, integrated analysis, GI cancer, gastroesophageal cancer, gastroesophageal junction, prognosis.


Assuntos
Neoplasias Esofágicas , Neoplasias Gástricas , Humanos , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidase 4/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Macrófagos/metabolismo
7.
Nanotheranostics ; 8(2): 247-269, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38444741

RESUMO

The post-pandemic era following the global spread of the SARS-CoV-2 virus has brought about persistent concerns regarding recurring coinfections. While significant strides in genome mapping, diagnostics, and vaccine development have controlled the pandemic and reduced fatalities, ongoing virus mutations necessitate a deeper exploration of the interplay between SARS-CoV-2 mutations and the host's immune response. Various vaccines, including RNA-based ones like Pfizer and Moderna, viral vector vaccines like Johnson & Johnson and AstraZeneca, and protein subunit vaccines like Novavax, have played critical roles in mitigating the impact of COVID-19. Understanding their strengths and limitations is crucial for tailoring future vaccines to specific variants and individual needs. The intricate relationship between SARS-CoV-2 mutations and the immune response remains a focus of intense research, providing insights into personalized treatment strategies and long-term effects like long-COVID. This article offers an overview of the post-pandemic landscape, highlighting emerging variants, summarizing vaccine platforms, and delving into immunological responses and the phenomenon of long-COVID. By presenting clinical findings, it aims to contribute to the ongoing understanding of COVID-19's progression in the aftermath of the pandemic.


Assuntos
COVID-19 , Coinfecção , Humanos , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda , Pandemias , Vacinas de Subunidades Proteicas
8.
J Biomol Struct Dyn ; 42(5): 2570-2585, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37116195

RESUMO

Malaria is among the top-ranked parasitic diseases that pose a threat to the existence of the human race. This study evaluated the antimalarial effect of the rhizome of Zingiber officinale in infected mice, performed secondary metabolite profiling and detailed computational antimalarial evaluation through molecular docking, molecular dynamics (MD) simulation and density functional theory methods. The antimalarial potential of Z. officinale was performed using the in vivo chemosuppressive model; secondary metabolite profiling was carried out using liquid chromatography-mass spectrometry (LC-MS). Molecular docking was performed with Autodock Vina while the MD simulation was performed with Schrodinger desmond suite for 100 ns and DFT calculations with B3LYP (6-31G) basis set. The extract showed 64% parasitaemia suppression, with a dose-dependent increase in activity up to 200 mg/kg. The chemical profiling of the extract tentatively identified eight phytochemicals. The molecular docking studies with plasmepsin II and Plasmodium falciparum dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) identified gingerenone A as the hit molecule, and MMGBSA values corroborate the binding energies obtained. The electronic parameters of gingerenone A revealed its significant antimalarial potential. The antimalarial activity elicited by the extract of Z. officinale and the bioactive chemical constituent supports its usage in ethnomedicine.Communicated by Ramaswamy H. Sarma.


Assuntos
Antimaláricos , Diarileptanoides , Antagonistas do Ácido Fólico , Zingiber officinale , Humanos , Animais , Camundongos , Antimaláricos/química , Simulação de Acoplamento Molecular , Espectrometria de Massa com Cromatografia Líquida , Cromatografia Líquida , Espectrometria de Massas em Tandem , Antagonistas do Ácido Fólico/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Plasmodium falciparum
9.
J Biol Chem ; 287(18): 14480-93, 2012 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-22408251

RESUMO

Translocases of mitochondrial inner membrane (TIMs) are multiprotein complexes. The only Tim component so far characterized in kinetoplastid parasites such as Trypanosoma brucei is Tim17 (TbTim17), which is essential for cell survival and mitochondrial protein import. Here, we report that TbTim17 is present in a protein complex of about 1,100 kDa, which is much larger than the TIM complexes found in fungi and mammals. Depletion of TbTim17 in T. brucei impairs the mitochondrial import of cytochrome oxidase subunit IV, an N-terminal signal-containing protein. Pretreatment of isolated mitoplasts with the anti-TbTim17 antibody inhibited import of cytochrome oxidase subunit IV, indicating a direct involvement of the TbTim17 in the import process. Purification of the TbTim17-containing protein complex from the mitochondrial membrane of T. brucei by tandem affinity chromatography revealed that TbTim17 associates with seven unique as well as a few known T. brucei mitochondrial proteins. Depletion of three of these novel proteins, i.e. TbTim47, TbTim54, and TbTim62, significantly decreased mitochondrial protein import in vitro. In vivo targeting of a newly synthesized mitochondrial matrix protein, MRP2, was also inhibited due to depletion of TbTim17, TbTim54, and TbTim62. Co-precipitation analysis confirmed the interaction of TbTim54 and TbTim62 with TbTim17 in vivo. Overall, our data reveal that TbTim17, the single homolog of Tim17/22/23 family proteins, is present in a unique TIM complex consisting of novel proteins in T. brucei and is critical for mitochondrial protein import.


Assuntos
Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo , Proteínas Mitocondriais/genética , Transporte Proteico/fisiologia , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/genética
10.
Life Sci Alliance ; 6(12)2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37793774

RESUMO

Anchorage-independent survival after intravasation of cancer cells from the primary tumor site represents a critical step in metastasis. Here, we reveal new insights into how MUC13-mediated anoikis resistance, coupled with survival of colorectal tumor cells, leads to distant metastasis. We found that MUC13 targets a potent transcriptional coactivator, YAP1, and drives its nuclear translocation via forming a novel survival complex, which in turn augments the levels of pro-survival and metastasis-associated genes. High expression of MUC13 is correlated well with extensive macrometastasis of colon cancer cells with elevated nuclear YAP1 in physiologically relevant whole animal model systems. Interestingly, a positive correlation of MUC13 and YAP1 expression was observed in human colorectal cancer tissues. In brief, the results presented here broaden the significance of MCU13 in cancer metastasis via targeting YAP1 for the first time and provide new avenues for developing novel strategies for targeting cancer metastasis.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Animais , Humanos , Neoplasias Colorretais/metabolismo , Fatores de Transcrição/genética , Mucinas/metabolismo
11.
Vaccines (Basel) ; 10(7)2022 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35891236

RESUMO

Background: The whole of humanity has suffered dire consequences related to the novel coronavirus disease 2019 (COVID-19). Vaccination of the world base population is considered the most promising and challenging approach to achieving herd immunity. As healthcare organizations took on the extensive task of vaccinating the entire U.S. population, digital health companies expanded their automated health platforms in order to help ease the administrative burdens of mass inoculation. Although some software companies offer free applications to large organizations, there are prohibitive costs for small clinics such as the Good Health Associates Clinic (GHAC) for integrating and implementing new self-scheduling software into our e-Clinical Works (ECW) Electronic Health Record (EHR). These cost burdens resulted in a search that extended beyond existing technology, and in investing in new solutions to make it easier, more efficient, more cost-effective, and more scalable. Objective: In comparison to commercial entities, primary care clinics (PCCs) have the advantage of engaging the population for vaccination through personalized continuity of clinical care due to good rapport between their patients and the PCC team. In order to support the overall national campaign to prevent COVID-19 infections and restore public health, the GHAC wanted to make COVID-19 vaccination accessible to its patients and to the communities it serves. We aimed to achieve a coordinated COVID-19 vaccination drive in our community through our small primary care clinic by developing and using an easily implementable, cost-effective self-registration and scheduling web-based mobile platform, using the principle of "C.D.S. Five Rights". Results: Overall, the Moderna vaccination drive using our developed self-registration and scheduling web portal and SMS messaging mobile platform improved vaccination uptake (51%) compared to overall vaccination uptake in our town, county (36%), and state (39%) during April-July 2021. Conclusions: Based on our experience during this COVID-19 vaccination drive, we conclude that PCCs have significant leverage as "invaluable warriors", along with government and media education available, to engage patients for vaccination uptake; this leads to national preventive health spread in our population, and reduces expenses related to acute illness and hospitalization. In terms of cost-effectiveness, small PCCs are worthy of government-sponsored funding and incentives, including mandating EHR vendors to provide free (or minimal fee) software for patient self-registration and scheduling, in order to improve vaccination drive access. Hence, improved access to personalized informative continuity of clinical care in the PCC setting is a "critical link" in accelerating similar cost-effective campaigns in patient vaccine uptake.

12.
Commun Biol ; 5(1): 1181, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333531

RESUMO

There is increasing evidence suggesting the role of microbiome alterations in relation to pancreatic adenocarcinoma and tumor immune functionality. However, molecular mechanisms of the interplay between microbiome signatures and/or their metabolites in pancreatic tumor immunosurveillance are not well understood. We have identified that a probiotic strain (Lactobacillus casei) derived siderophore (ferrichrome) efficiently reprograms tumor-associated macrophages (TAMs) and increases CD8 + T cell infiltration into tumors that paralleled a marked reduction in tumor burden in a syngeneic mouse model of pancreatic cancer. Interestingly, this altered immune response improved anti-PD-L1 therapy that suggests promise of a novel combination (ferrichrome and immune checkpoint inhibitors) therapy for pancreatic cancer treatment. Mechanistically, ferrichrome induced TAMs polarization via activation of the TLR4 pathway that represses the expression of iron export protein ferroportin (FPN1) in macrophages. This study describes a novel probiotic based molecular mechanism that can effectively induce anti-tumor immunosurveillance and improve immune checkpoint inhibitors therapy response in pancreatic cancer.


Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Probióticos , Camundongos , Animais , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/metabolismo , Adenocarcinoma/metabolismo , Sideróforos , Microambiente Tumoral , Ferricromo/uso terapêutico , Monitorização Imunológica , Inibidores de Checkpoint Imunológico , Probióticos/farmacologia , Neoplasias Pancreáticas
13.
Structure ; 17(3): 363-73, 2009 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-19278651

RESUMO

The general transcription factor TFIID is a large multisubunit complex required for the transcription of most protein-encoding genes by RNA polymerase II. Taking advantage of a TFIID preparation partially depleted in the initiator-binding Taf2p subunit, we determined the conformational and biochemical variations of the complex by electron tomography and cryo-electron microscopy of single molecules. Image analysis revealed the extent of conformational flexibility of the complex and the selection of the most homogeneous TFIID subpopulation allowed us to determine an improved structural model at 23 Angstroms resolution. This study also identified two subpopulations of Taf2p-containing and Taf2p-depleted TFIID molecules. By comparing these two TFIID species we could infer the position of Taf2p, which was confirmed by immunolabeling using a subunit-specific antibody. Mapping the position of this crucial subunit in the vicinity of Taf1p and of TBP sheds new light on its role in promoter recognition.


Assuntos
Subunidades Proteicas/química , Proteínas de Saccharomyces cerevisiae/química , Fatores Associados à Proteína de Ligação a TATA/química , Fator de Transcrição TFIID/química , Sequência de Aminoácidos , Sítios de Ligação , Microscopia Crioeletrônica , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Subunidades Proteicas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/metabolismo
14.
Biomedicines ; 9(10)2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34680499

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has disrupted social and economic life globally. The global pandemic COVID-19 caused by this novel SARS-CoV-2 shows variable clinical manifestations, complicated further by cytokine storm, co-infections, and coagulopathy, leading to severe cases and death. Thrombotic complications arise due to complex and unique interplay between coronaviruses and host cells, inflammatory response, and the coagulation system. Heparin and derivatives are World Health Organization (WHO) recommended anticoagulants for moderate and severe Corona Virus Disease 19 (COVID-19), that can also inhibit viral adhesion to the cell membrane by interfering with heparan sulfate-dependent binding to angiotensin-converting enzyme 2 (ACE2) receptor. Heparin also possesses anti-inflammatory, immunomodulatory, antiviral, and anti-complement activity, which offers a benefit in limiting viral and microbial infectivity and anticoagulation from the immune-thrombosis system. Here we present a case study of the pathophysiology of unexpected COVID-19 coagulopathy of an obese African American patient. While being on therapeutic warfarin since admission, he had a dismal outcome due to cardio-pulmonary arrest after the sudden rise in D-dimer value from 1.1 to >20. This indicates that for such patients on chronic warfarin anticoagulation with "moderate COVID 19 syndromes", warfarin anticoagulation may not be suitable compared to heparin and its derivatives. Further research should be done to understand the beneficial role of heparin and its derivatives compared to warfarin for COVID-19 inflicted patients.

15.
Biomed J Sci Tech Res ; 37(3): 29427-29431, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35071996

RESUMO

The well-defined and characterized 3D crystal structure of a protein is important to explore the topological and physiological features of the protein. The distinguished topography of a protein helps medical chemists design drugs on the basis of the pharmacophoric features of the protein. Structure-based drug discovery, specifically for pathological proteins that cause a higher risk of disease, takes advantage of this fact. Current tools for studying drug-protein interactions include physical, chromatographic, and electrophoretic methods. These techniques can be separated into either non-spectroscopic (equilibrium dialysis, ultrafiltration, ultracentrifugation, etc.) or spectroscopic (Fluorescence spectroscopy, NMR, X-ray diffraction, etc.) methods. These methods, however, can be time-consuming and expensive. On the other hand, in silico methods of analyzing protein-drug interactions, such as docking, molecular simulations, and High-Throughput Virtual Screenings (HTVS), are heavily underutilized by core drug discovery laboratories. These kinds of approaches have a great potential for the mass screening of potential small drugs molecules. Studying protein-drug interactions is of particular importance for understanding how the structural conformation of protein elements affect overall ligand binding affinity. By taking a bioinformatics approach to analyzing drug-protein interactions, the speed with which we identify potential drugs for genetic targets can be greatly increased.

16.
Biomedicines ; 9(12)2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34944630

RESUMO

Pancreatic cancer has the worst prognosis and lowest survival rate among all cancers. Pancreatic cancer cells are highly metabolically active and typically reprogrammed for aberrant glucose metabolism; thus they respond poorly to therapeutic modalities. It is highly imperative to understand mechanisms that are responsible for high glucose metabolism and identify natural/synthetic agents that can repress glucose metabolic machinery in pancreatic cancer cells, to improve the therapeutic outcomes/management of pancreatic cancer patients. We have identified a glycoside, steviol that effectively represses glucose consumption in pancreatic cancer cells via the inhibition of the translation initiation machinery of the molecular components. Herein, we report that steviol effectively inhibits the glucose uptake and lactate production in pancreatic cancer cells (AsPC1 and HPAF-II). The growth, colonization, and invasion characteristics of pancreatic cancer cells were also determined by in vitro functional assay. Steviol treatment also inhibited the tumorigenic and metastatic potential of human pancreatic cancer cells by inducing apoptosis and cell cycle arrest in the G1/M phase. The metabolic shift by steviol was mediated through the repression of the phosphorylation of mTOR and translation initiation proteins (4E-BP1, eIF4e, eIF4B, and eIF4G). Overall, the results of this study suggest that steviol can effectively suppress the glucose metabolism and translation initiation in pancreatic cancer cells to mitigate their aggressiveness. This study might help in the design of newer combination therapeutic strategies for pancreatic cancer treatment.

17.
Mol Cancer ; 9: 50, 2010 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-20202217

RESUMO

BACKGROUND: BRCA2 gene expression is tightly regulated during the cell cycle in human breast cells. The expression of BRCA2 gene is silenced at the G0/G1 phase of cell growth and is de-silenced at the S/G2 phase. While studying the activity of BRCA2 gene promoter in breast cancer cells, we discovered that this promoter has bi-directional activity and the product of the reverse activity (a ZAR1-like protein, we named ZAR2) silences the forward promoter at the G0/G1 phase of the cell. Standard techniques like cell synchronization by serum starvation, flow cytometry, N-terminal or C-terminal FLAG epitope-tagged protein expression, immunofluorescence confocal microscopy, dual luciferase assay for promoter evaluation, and chromatin immunoprecipitation assay were employed during this study. RESULTS: Human BRCA2 gene promoter is active in both the forward and the reverse orientations. This promoter is 8-20 fold more active in the reverse orientation than in the forward orientation when the cells are in the non-dividing stage (G0/G1). When the cells are in the dividing state (S/G2), the forward activity of the promoter is 5-8 folds higher than the reverse activity. The reverse activity transcribes the ZAR2 mRNA with 966 nt coding sequence which codes for a 321 amino acid protein. ZAR2 has two C4 type zinc fingers at the carboxyl terminus. In the G0/G1 growth phase ZAR2 is predominantly located inside the nucleus of the breast cells, binds to the BRCA2 promoter and inhibits the expression of BRCA2. In the dividing cells, ZAR2 is trapped in the cytoplasm. CONCLUSIONS: BRCA2 gene promoter has bi-directional activity, expressing BRCA2 and a novel C4-type zinc finger containing transcription factor ZAR2. Subcellular location of ZAR2 and its expression from the reverse promoter of the BRCA2 gene are stringently regulated in a cell cycle dependent manner. ZAR2 binds to BRCA2/ZAR2 bi-directional promoter in vivo and is responsible, at least in part, for the silencing of BRCA2 gene expression in the G0/G1 phase in human breast cells.


Assuntos
Proteína BRCA2/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ciclo Celular/genética , Regulação Neoplásica da Expressão Gênica , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Regiões 5' não Traduzidas/genética , Animais , Proteína BRCA2/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Códon/genética , Sequência Conservada , Citosol/metabolismo , Éxons/genética , Feminino , Fase G1 , Técnicas de Silenciamento de Genes , Rearranjo Gênico/genética , Humanos , Íntrons/genética , Transporte Proteico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fase de Repouso do Ciclo Celular , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/metabolismo , Vertebrados/genética
18.
Mol Cell Biol ; 27(1): 297-311, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17074814

RESUMO

In vivo studies have previously shown that Saccharomyces cerevisiae ribosomal protein (RP) gene expression is controlled by the transcription factor repressor activator protein 1 (Rap1p) in a TFIID-dependent fashion. Here we have tested the hypothesis that yeast TFIID serves as a coactivator for RP gene transcription by directly interacting with Rap1p. We have found that purified recombinant Rap1p specifically interacts with purified TFIID in pull-down assays, and we have mapped the domains of Rap1p and subunits of TFIID responsible. In vitro transcription of a UAS(RAP1) enhancer-driven reporter gene requires both Rap1p and TFIID and is independent of the Fhl1p-Ifh1p coregulator. UAS(RAP1) enhancer-driven transactivation in extracts depleted of both Rap1p and TFIID is efficiently rescued by addition of physiological amounts of these two purified factors but not TATA-binding protein. We conclude that Rap1p and TFIID directly interact and that this interaction contributes importantly to RP gene transcription.


Assuntos
Regulação Fúngica da Expressão Gênica , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/genética , Proteínas de Ligação a Telômeros/fisiologia , Fator de Transcrição TFIID/química , Fatores de Transcrição/fisiologia , Ligação Competitiva , Proteínas de Ligação a DNA/química , Elementos Facilitadores Genéticos , Ligação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Complexo Shelterina , Proteína de Ligação a TATA-Box/química , Proteínas de Ligação a Telômeros/química , Proteínas de Ligação a Telômeros/metabolismo , Fator de Transcrição TFIID/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Transcrição Gênica , Ativação Transcricional
19.
ACS Appl Mater Interfaces ; 11(42): 38537-38554, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31553876

RESUMO

Cellular senescence is one of the prevailing issues in cancer therapeutics that promotes cancer relapse, chemoresistance, and recurrence. Patients undergoing persistent chemotherapy often develop drug-induced senescence. Docetaxel, an FDA-approved treatment for prostate cancer, is known to induce cellular senescence which often limits the overall survival of patients. Strategic therapies that counter the cellular and drug-induced senescence are an unmet clinical need. Towards this an effort was made to develop a novel therapeutic strategy that targets and removes senescent cells from the tumors, we developed a nanoformulation of tannic acid-docetaxel self-assemblies (DSAs). The construction of DSAs was confirmed through particle size measurements, spectroscopy, thermal, and biocompatibility studies. This formulation exhibited enhanced in vitro therapeutic activity in various biological functional assays with respect to native docetaxel treatments. Microarray and immunoblot analysis results demonstrated that DSAs exposure selectively deregulated senescence associated TGFßR1/FOXO1/p21 signaling. Decrease in ß-galactosidase staining further suggested reversion of drug-induced senescence after DSAs exposure. Additionally, DSAs induced profound cell death by activation of apoptotic signaling through bypassing senescence. Furthermore, in vivo and ex vivo imaging analysis demonstrated the tumor targeting behavior of DSAs in mice bearing PC-3 xenograft tumors. The antisenescence and anticancer activity of DSAs was further shown in vivo by inhibiting TGFßR1 proteins and regressing tumor growth through apoptotic induction in the PC-3 xenograft mouse model. Overall, DSAs exhibited such advanced features due to a natural compound in the formulation as a matrix/binder for docetaxel. Overall, DSAs showed superior tumor targeting and improved cellular internalization, promoting docetaxel efficacy. These findings may have great implications in prostate cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Senescência Celular/efeitos dos fármacos , Docetaxel/química , Nanoestruturas/química , Polifenóis/química , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Docetaxel/farmacologia , Docetaxel/uso terapêutico , Proteína Forkhead Box O1/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Receptor do Fator de Crescimento Transformador beta Tipo I/metabolismo , Transdução de Sinais/efeitos dos fármacos , Taninos/química , Transplante Heterólogo
20.
J Colloid Interface Sci ; 535: 133-148, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30292104

RESUMO

Paclitaxel (PTX) is a gold standard chemotherapeutic agent for breast, ovarian, pancreatic and non-small cell lung carcinoma. However, in clinical use PTX can have adverse side effects or inadequate pharmacodynamic parameters, limiting its use. Nanotechnology is often employed to reduce the therapeutic dosage required for effective therapy, while also minimizing the systemic side effects of chemotherapy drugs. However, there is no nanoformulation of paclitaxel with chemosensitization motifs built in. With this objective, we screened eleven pharmaceutical excipients to develop an alternative paclitaxel nanoformulation using a self-assembly method. Based on the screening results, we observed tannic acid possesses unique properties to produce a paclitaxel nanoparticle formulation, i.e., tannic acid-paclitaxel nanoparticles. This stable TAP nanoformulation, referred to as TAP nanoparticles (TAP NPs), showed a spherical shape of ~ 102 nm and negative zeta potential of ~ -8.85. The presence of PTX in TAP NPs was confirmed by Fourier Transform Infrared (FTIR) spectra, thermogravimetric analyzer (TGA), and X-ray diffraction (XRD). Encapsulation efficiency of PTX in TAP NPs was determined to be ≥96%. Intracellular drug uptake of plain drug PTX on breast cancer cells (MDA-MB-231) shows more or less constant drug levels in 2 to 6 h, suggesting drug efflux by the P-gp transporters, over TAP NPs, in which PTX uptake was more than 95.52 ±â€¯11.01% in 6 h, as analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Various biological assays such as proliferation, clonogenic formation, invasion, and migration confirm superior anticancer effects of TAP NPs over plain PTX at all tested concentrations. P-gp expression, beta-tubulin stabilization, Western blot, and microarray analysis further confirm the improved therapeutic potential of TAP NPs. These results suggest that the TAP nanoformulation provides an important reference for developing a therapeutic nanoformulation affording pronounced, enhanced effects in breast cancer therapy.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Nanopartículas/química , Paclitaxel/farmacologia , Taninos/química , Antineoplásicos Fitogênicos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células MCF-7 , Paclitaxel/química , Tamanho da Partícula , Propriedades de Superfície , Espectrometria de Massas em Tandem , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa