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1.
Psychol Trauma ; 16(3): 382-389, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37824259

RESUMO

OBJECTIVE: Black pregnant individuals are at disproportionate risk for posttraumatic stress disorder (PTSD) compared to other groups. A wealth of literature suggests racial stress contributes to this inequity, but cultural and structural mechanisms, such as perceived barriers to mental health treatment, underlying the relationship between racial stress and PTSD symptoms remain understudied. Negative evaluations of psychotherapy and stigma represent potential mechanisms, though no previous studies have examined these associations. To address this gap, we tested an indirect effect of racial stress on PTSD symptoms through perceived barriers to mental health treatment in pregnant Black individuals. METHOD: Mediation analyses were used to assess an indirect relationship between racial stress and PTSD symptoms through perceived barriers to mental health treatment. RESULTS: At the bivariate level, racial stress was significantly associated with PTSD symptoms (r = .20, p = .03) and negative evaluations of therapy (r = .22, p = .02), but not with stigma (r = .140, p = .147). Negative evaluations of therapy were also associated with PTSD symptoms (r = .43, p < .001). There was an indirect effect of racial stress on PTSD symptoms through a negative evaluation of therapy, ß = .08, SE = 0.04, CI [0.01, 0.18]. More specifically, racial stress was associated with a more negative evaluation of therapy, which was in turn associated with more PTSD symptoms. CONCLUSIONS: Results highlight the need for accessible and culturally competent mental health care for pregnant Black individuals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Gestantes , Racismo , Transtornos de Estresse Pós-Traumáticos , Feminino , Humanos , Gravidez , Negro ou Afro-Americano , Psicoterapia , Grupos Raciais , Transtornos de Estresse Pós-Traumáticos/psicologia , Racismo/psicologia , Gestantes/psicologia
2.
Front Med (Lausanne) ; 10: 1204274, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37396888

RESUMO

Background: A growing body of literature has revealed that many medical students and doctors do not seek professional help for their mental health due to fear of stigma (both public- and self-stigma) and questioning of their clinical competency. The aim of this systematic review was to identify and evaluate direct and indirect interventions that address mental health stigma in medical students and/or doctors. We focused explicitly on studies that measured the impact on self-stigma outcomes. Method: A systematic search of the following electronic databases was undertaken from inception to 13 July 2022: PubMed, Embase, PsycINFO, and CINAHL, together with manual searching of reference lists. Screening of titles, abstracts, and full texts of eligible studies, plus quality appraisal using the Mixed Methods Appraisal Tool, were independently conducted by multiple reviewers with disagreements resolved via discussion. Results: From 4,018 citations, five publications met the inclusion criteria. None of the studies explicitly aimed to reduce self-stigmatisation, with the majority focusing on medical students. Most of the identified interventions focused on reducing professional stigma (i.e., stigma toward patients with mental illness) and measurement of self-stigma was incidentally collected via a subscale of the general stigma measure selected. Three studies found significant reductions in self-stigma following the delivered intervention. These studies were of moderate quality, had medical student samples, employed combined education and contact interventions, and used the same outcome measure. Discussion: Intentional development and evaluation of interventions specifically designed to decrease self-stigma among doctors and medical students are needed, with further research required on the optimal components, format, length, and delivery of such interventions. Researchers delivering public/professional stigma reduction interventions should strongly consider measuring the impact of such interventions on self-stigma outcomes, using fit-for-purpose, psychometrically sound instruments.

3.
Br J Cancer ; 128(9): 1765-1776, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36810910

RESUMO

BACKGROUND: Ovarian cancers are hallmarked by chromosomal instability. New therapies deliver improved patient outcomes in relevant phenotypes, however therapy resistance and poor long-term survival signal requirements for better patient preselection. An impaired DNA damage response (DDR) is a major chemosensitivity determinant. Comprising five pathways, DDR redundancy is complex and rarely studied alongside chemoresistance influence from mitochondrial dysfunction. We developed functional assays to monitor DDR and mitochondrial states and trialled this suite on patient explants. METHODS: We profiled DDR and mitochondrial signatures in cultures from 16 primary-setting ovarian cancer patients receiving platinum chemotherapy. Explant signature relationships to patient progression-free (PFS) and overall survival (OS) were assessed by multiple statistical and machine-learning methods. RESULTS: DR dysregulation was wide-ranging. Defective HR (HRD) and NHEJ were near-mutually exclusive. HRD patients (44%) had increased SSB abrogation. HR competence was associated with perturbed mitochondria (78% vs 57% HRD) while every relapse patient harboured dysfunctional mitochondria. DDR signatures classified explant platinum cytotoxicity and mitochondrial dysregulation. Importantly, explant signatures classified patient PFS and OS. CONCLUSIONS: Whilst individual pathway scores are mechanistically insufficient to describe resistance, holistic DDR and mitochondrial states accurately predict patient survival. Our assay suite demonstrates promise for translational chemosensitivity prediction.


Assuntos
Neoplasias Ovarianas , Platina , Humanos , Feminino , Platina/uso terapêutico , Dano ao DNA , Recidiva Local de Neoplasia , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Aprendizado de Máquina
4.
BMJ Open ; 11(11): e053616, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34725081

RESUMO

OBJECTIVES: Immersive technologies such as virtual (VR) and augmented reality (AR) can potentially help health professionals and trainees understand psychological symptoms and responsive behaviours associated with dementia within a safe and supportive learning environment. This integrative review sought to ascertain the types of VR and AR-based interventions used in dementia education and training and its efficacy to improve knowledge and attitudes of health professionals or trainees. DESIGN: The protocol was submitted to PROSPERO and literature published from 2000 onwards was searched in eight databases: CINAHL, MEDLINE, Web of Science, Cochrane, Embase, PsycINFO, ERIC and Scopus. A total of 19 articles were included and assessed with the Mixed Methods Appraisal Tool. Methodological quality varied across studies. RESULTS: VR rather than AR-based intervention are used in dementia education and training for health professional and trainees. Immersive virtual learning potentially enhance knowledge, attitudes, empathy and sensitivity of health professionals and trainees. CONCLUSIONS: While promising, there remains a lack of conclusive and robust evidence to fully recommend the introduction and inclusion of immersive virtual learning in dementia education and training. Additional rigorously designed research studies with larger sample sizes are needed to confirm the benefits on attitudes, empathy, sensitivity and knowledge. PROSPERO REGISTRATION NUMBER: CRD42020182083.


Assuntos
Realidade Aumentada , Demência , Realidade Virtual , Atitude , Demência/terapia , Educação em Saúde , Humanos
5.
J Minim Invasive Gynecol ; 28(9): 1633-1636, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33582377

RESUMO

STUDY OBJECTIVE: The risks to surgeons of carrying out aerosol-generating procedures during the coronavirus disease 2019 (COVID-19) pandemic are unknown. To start to define these risks, in a systematic manner, we investigated the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in the abdominal fluid and lower genital tract of patients undergoing surgery. DESIGN: Prospective cross-sectional observational study. SETTING: Single, large United Kingdom hospital. PATIENTS: Total of 113 patients undergoing abdominal surgery or instrumentation of the lower genital tract. INTERVENTIONS: We took COVID-19 swabs from the peritoneal cavity and from the vagina from all eligible patients. Results were stratified by preoperative COVID-19 status. MEASUREMENTS AND MAIN RESULTS: In patients who were presumed COVID-19 negative at the time of surgery, SARS-CoV-2 virus RNA was detected in 0 of 102 peritoneal samples and 0 of 98 vaginal samples. Both cohorts included 4 patients who were antibody positive but nasopharyngeal swab test negative at the time of surgery. Peritoneal and vaginal swabs were also negative in 1 patient who had a positive nasopharyngeal swab immediately before surgery. CONCLUSION: The presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract of presumed negative patients is nil or extremely low. These data will inform surgeons of the risks of restarting laparoscopic surgery at a time when COVID-19 is endemic in the population.


Assuntos
COVID-19 , SARS-CoV-2 , Estudos Transversais , Feminino , Humanos , Peritônio , Estudos Prospectivos , RNA Viral , Vagina
6.
Med Sci Educ ; 30(4): 1351-1352, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34457800

RESUMO

With the increasing volume of information for students to learn in a health sciences and medicine degree, tertiary educators need teaching resources that can maintain up-to-date information and educate effectively across a range of diseases and illnesses. Holograms may be the disruptive technology that can assist in this goal.

7.
BMC Cancer ; 18(1): 421, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29653561

RESUMO

BACKGROUND: Dysregulation of microRNA (miRNA) expression is associated with hallmarks of aggressive tumor phenotypes, e.g., enhanced cell growth, proliferation, invasion, and anchorage independent growth in prostate cancer (PCa). METHODS: Serum-based miRNA profiling involved 15 men diagnosed with non-metastatic (stage I, III) and metastatic (stage IV) PCa and five age-matched disease-free men using miRNA arrays with select targets confirmed by quantitative real-time PCR (qRT-PCR). The effect of miR-186-5p inhibition or ectopic expression on cellular behavior of PCa cells (i.e., PC-3, MDA-PCa-2b, and LNCaP) involved the use bromodeoxyuridine (BrdU) incorporation, invasion, and colony formation assays. Assessment of the impact of miR-186-5p inhibition or overexpression on selected targets entailed microarray analysis, qRT-PCR, and/or western blots. Statistical evaluation used the modified t-test and ANOVA analysis. RESULTS: MiR-186-5p was upregulated in serum from PCa patients and metastatic PCa cell lines (i.e., PC-3, MDA-PCa-2b, LNCaP) compared to serum from disease-free individuals or a normal prostate epithelial cell line (RWPE1), respectively. Inhibition of miR-186-5p reduced cell proliferation, invasion, and anchorage-independent growth of PC-3 and/or MDA-PCa-2b PCa cells. AKAP12, a tumor suppressor target of miR-186-5p, was upregulated in PC-3 and MDA-PCa-2b cells transfected with a miR-186-5p inhibitor. Conversely, ectopic miR-186-5p expression in HEK 293 T cells decreased AKAP12 expression by 30%. Both pAKT and ß-catenin levels were down-regulated in miR-186-5p inhibited PCa cells. CONCLUSIONS: Our findings suggest miR-186-5p plays an oncogenic role in PCa. Inhibition of miR-186-5p reduced PCa cell proliferation and invasion as well as increased AKAP12 expression. Future studies should explore whether miR-186-5p may serve as a candidate prognostic indicator and a therapeutic target for the treatment of aggressive prostate cancer.


Assuntos
MicroRNAs/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas de Ancoragem à Quinase A/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , MicroRNA Circulante , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/sangue , Invasividade Neoplásica , Metástase Neoplásica , Estadiamento de Neoplasias , Neoplasias da Próstata/sangue , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reprodutibilidade dos Testes , Transcriptoma , beta Catenina/genética
8.
Gene ; 636: 96-102, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28903065

RESUMO

African ancestry and obesity are associated with higher risk of prostate cancer (PC). In a pilot study, we explored interactions between obesity (as measured by waist to hip ratio (WHR)) and inflammatory SNPs in relation to PC risk among Jamaican men. This study evaluated 87 chemokine and cytokine associated SNPs in obese and normal weight cases (N=109) and controls (N=102) using a stepwise penalized logistic regression approach in multivariable analyses. Upon stratification by WHR (normal weight (WHR<0.90) or obese (WHR≥0.90)), inheritance of CCR6 rs2023305 AG+GG (OR=1.75, p=0.007), CCR9 rs7613548 AG+GG (OR=1.71, p=0.012) and IL10ra rs2229113 AG+GG (OR=1.45, p=0.01) genotypes was associated with increase in overall or low grade (Gleason score<7) PC risk among normal weight men. These odds were elevated among obese men who possessed the CCR5 rs1799987 AG+GG (OR=1.95, p=0.003) and RNASEL rs12135247 CT+TT genotypes (OR=1.59, p=0.05). CCR7 rs3136685 AG+GG (p=0.032) was associated with a 1.52-1.70 fold increase in the risk of high grade cancer (Gleason score≥7) among obese men. CCR7 variant emerged as an important factor associated with high grade PC risk among obese men in our analyses. Overall, genetic loci found significant in normal weight men were not significant in obese men and vice-versa, partially explaining the role of obesity on PC risk among black men. Also, older age was an important risk factor both in normal weight and obese men but only with regard to low grade PC. Associations of inflammatory SNPs with obesity are suggestive and require further validation in larger cohorts to help develop an understanding of PC risk among obese and non-obese men of African descent.


Assuntos
Tamanho Corporal , Obesidade/complicações , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , População Negra/genética , Estudos de Casos e Controles , Quimiocinas/genética , Citocinas/genética , Interação Gene-Ambiente , Humanos , Mediadores da Inflamação , Jamaica , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Neoplasias da Próstata/etiologia , Fatores de Risco
9.
Vaccine ; 35(24): 3232-3238, 2017 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-28479180

RESUMO

Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in infected mosquitoes, is a lead transmission-blocking vaccine candidate against falciparum malaria. To enhance immunogenicity, recombinant Pfs25 was chemically conjugated to recombinant nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA) in conformance with current good manufacturing practices (cGMP), and formulated with the alum adjuvant Alhydrogel. In order to meet the regulatory requirements for a phase 1 human clinical trial, the vaccine product was extensively evaluated for stability at an initial time point and through the clinical trial period annually. Because basic quality control methods to characterize alum-based vaccines remain unavailable, a thermal forced degradation study was performed prior to the initial evaluation to identify the methods suitable to detect the quality of vaccine formulations. Our results show that the vaccine product Pfs25-EPA formulated on Alhydrogel is in conformance with regulatory guidelines and suitable for human trials.


Assuntos
Hidróxido de Alumínio/imunologia , Vacinas Antimaláricas/imunologia , Proteínas de Protozoários/imunologia , Potência de Vacina , Adjuvantes Imunológicos , Alumínio/análise , Hidróxido de Alumínio/química , Animais , Ensaios Clínicos Fase I como Assunto , Composição de Medicamentos , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/química , Malária Falciparum/prevenção & controle , Camundongos , Plasmodium falciparum/imunologia , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/genética , Proteínas Recombinantes/imunologia , Temperatura
10.
BMC Urol ; 17(1): 18, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28320379

RESUMO

Prostate cancer is the most common malignancy among men in the US. Though considerable improvement in the diagnosis of prostate cancer has been achieved in the past decade, predicting disease outcome remains a major clinical challenge. Recent expression profiling studies in prostate cancer suggest microRNAs (miRNAs) may serve as potential biomarkers for prostate cancer risk and disease progression. miRNAs comprise a large family of about 22-nucleotide-long non-protein coding RNAs, regulate gene expression post-transcriptionally and participate in the regulation of numerous cellular processes. In this review, we discuss the current status of miRNA in studies evaluating the disease progression of prostate cancer. The discussion highlights key findings from previous studies, which reported the role of miRNAs in risk and progression of prostate cancer, providing an understanding of the influence of miRNA on prostate cancer. Our review indicates that somewhat consistent results exist between these studies and reports on several prostate cancer related miRNAs. Present promising candidates are miR-1, -21, 106b, 141, -145, -205, -221, and -375, which are the most frequently studied and seem to be the most promising for diagnosis and prognosis for prostate cancer. Nevertheless, the findings from previous studies suggest miRNAs may play an important role in the risk and progression of prostate cancer as promising biomarkers.


Assuntos
Progressão da Doença , MicroRNAs , Neoplasias da Próstata/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/metabolismo
11.
Biochem Pharmacol ; 89(3): 399-412, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24721462

RESUMO

Obesity is a complex metabolic disorder that is more prevalent among women. Until now, the only relevant rodent models of diet-induced obesity were via the use of ovariectomized ("postmenopausal") females. However, recent reports suggest that the xenobiotic nuclear receptor pregnane X receptor (PXR) may contribute to obesity. Therefore, we compared the roles of mouse and human PXRs in diet-induced obesity between wild type (WT) and PXR-humanized (hPXR) transgenic female mice fed either control or high-fat diets (HFD) for 16 weeks. HFD-fed hPXR mice gained weight more rapidly than controls, exhibited hyperinsulinemia, and impaired glucose tolerance. Fundamental differences were observed between control-fed hPXR and WT females: hPXR mice possessed reduced estrogen receptor α (ERα) but enhanced uncoupling protein 1 (UCP1) protein expression in white adipose tissue (WAT); increased protein expression of the hepatic cytochrome P450 3A11 (CYP3A11) and key gluconeogenic enzymes phosphoenolpyruvate carboxykinase and glucose 6-phosphatase, and increased total cholesterol. Interestingly, HFD ingestion induced both UCP1 and glucokinase protein expression in WT mice, but inhibited these enzymes in hPXR females. Unlike WT mice, CYP3A11 protein, serum 17ß-estradiol levels, and WAT ERα expression were unaffected by HFD in hPXR females. Together, these studies indicate that the hPXR gene promotes obesity and metabolic syndrome by dysregulating lipid and glucose homeostasis while inhibiting UCP1 expression. Furthermore, our studies indicate that the human PXR suppresses the protective role of estrogen in metabolic disorders. Finally, these data identify PXR-humanized mice as a promising in vivo research model for studying obesity and diabetes in women.


Assuntos
Gorduras na Dieta/efeitos adversos , Obesidade/tratamento farmacológico , Receptores de Esteroides/metabolismo , Tecido Adiposo Branco , Animais , Glicemia , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Feminino , Regulação da Expressão Gênica , Intolerância à Glucose , Humanos , Canais Iônicos/genética , Canais Iônicos/metabolismo , Fígado , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Obesidade/etiologia , Receptor de Pregnano X , Receptores de Esteroides/genética , Proteína Desacopladora 1
12.
Hered Cancer Clin Pract ; 11(1): 19, 2013 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-24359571

RESUMO

PURPOSE: Although case-control studies have evaluated the role of variant inflammatory-related loci in prostate cancer, their impact is virtually unknown among men of African descent. To address this, we evaluated the impact of inflammatory cytokine single nucleotide polymorphisms (SNPs) on prostate cancer risk for men of African descent. METHODS: Forty-four SNPs in inflammatory cytokine-associated genes were evaluated among 814 African-American and Jamaican men (279 prostate cancer cases and 535 controls) using Illumina's Golden gate genotyping system. Individual SNP effects were evaluated using logistic regression analysis. RESULTS: Four SNPs were modestly associated with prostate cancer after adjusting for age. In the total population, inheritance of the IL1R2 rs11886877 AA, IL8RB rs11574752 AA, TNF rs1800629 GA + AA, and TNF rs673 GA genotypes modestly increased prostate cancer risk by 1.45 to 11.7-fold relative to the referent genotype. Among U.S. men, age-adjusted dominant, recessive and additive genetic models for the IL1R2 rs11886877 locus were linked to an increase in prostate cancer susceptibility. However, these main effects did not persist after adjusting for multiple hypothesis testing. CONCLUSION: Our preliminary data does not strongly support the hypothesis that inflammatory-related sequence variants influence prostate cancer risk among men of African descent. However, further evaluation is needed to assess whether other variant inflammatory-related genes may contribute to prostate cancer risk and disease progression in larger and ethnically diverse multi-center studies.

13.
Artigo em Inglês | MEDLINE | ID: mdl-24648757

RESUMO

Mounting evidence indicates that anomalies in the inflammatory and immune response pathways are essential to tumorigenesis. However, tumor-based innate immunity initiated by transformed breast epithelia tissues has received much less attention. This review summarizes published reports on the role of the toll-like receptor signaling pathway on breast cancer risk, disease progression, survival, and disease recurrence. Specifically, we discuss the underlying biological mechanisms that contribute to the tumorigenic and/or anti-tumorigenic properties of toll-like receptors and their associated agonists in relation to breast tumorigenesis and cancer treatment. Further, we use results from preclinical, clinical, and population-based studies as prompts for the exploration of new and more effective breast cancer therapies. As the knowledge base of innate immunity's involvement in breast cancer progression increases, current and new immune-modifying strategies will be refined to effectively treat breast cancer.

14.
Hered Cancer Clin Pract ; 10(1): 16, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23168091

RESUMO

BACKGROUND: Chemokine and chemokine receptors play an essential role in tumorigenesis. Although chemokine-associated single nucleotide polymorphisms (SNPs) are associated with various cancers, their impact on prostate cancer (PCA) among men of African descent is unknown. Consequently, this study evaluated 43 chemokine-associated SNPs in relation to PCA risk. We hypothesized inheritance of variant chemokine-associated alleles may lead to alterations in PCA susceptibility, presumably due to variations in antitumor immune responses. METHODS: Sequence variants were evaluated in germ-line DNA samples from 814 African-American and Jamaican men (279 PCA cases and 535 controls) using Illumina's Goldengate genotyping system. RESULTS: Inheritance of CCL5 rs2107538 (AA, GA+AA) and rs3817655 (AA, AG, AG+AA) genotypes were linked with a 34-48% reduction in PCA risk. Additionally, the recessive and dominant models for CCR5 rs1799988 and CCR7 rs3136685 were associated with a 1.52-1.73 fold increase in PCA risk. Upon stratification, only CCL5 rs3817655 and CCR7 rs3136685 remained significant for the Jamaican and U.S. subgroups, respectively. CONCLUSIONS: In summary, CCL5 (rs2107538, rs3817655) and CCR5 (rs1799988) sequence variants significantly modified PCA susceptibility among men of African descent, even after adjusting for age and multiple comparisons. Our findings are only suggestive and require further evaluation and validation in relation to prostate cancer risk and ultimately disease progression, biochemical/disease recurrence and mortality in larger high-risk subgroups. Such efforts will help to identify genetic markers capable of explaining disproportionately high prostate cancer incidence, mortality, and morbidity rates among men of African descent.

15.
Eukaryot Cell ; 11(5): 615-25, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22467743

RESUMO

Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium falciparum proteins containing TSR domains play crucial roles in parasite development. In particular, the preerythrocytic P. falciparum circumsporozoite protein is involved in hepatocyte invasion. The importance of these domains in two other malaria proteins, the merozoite-specific thrombospondin-related anonymous protein (MTRAP) and the thrombospondin-related apical membrane protein (PTRAMP), were assessed using near-full-length recombinant proteins composed of the extracellular domains produced in Escherichia coli. MTRAP is thought to be released from invasive organelles identified as micronemes during merozoite invasion to mediate motility and host cell invasion through an interaction with aldolase, an actin binding protein involved in the moving junction. PTRAMP function remains unknown. In this study, the conformation of recombinant MTRAP (rMTRAP) appeared to be a highly extended protein (2 nm by 33 nm, width by length, respectively), whereas rPTRAMP had a less extended structure. Using an erythrocyte binding assay, rMTRAP but not rPTRAMP bound human erythrocytes; rMTRAP binding was mediated through the TSR domain. MTRAP- and in general PTRAMP-specific antibodies failed to inhibit P. falciparum development in vitro. Altogether, MTRAP is a highly extended bifunctional protein that binds to an erythrocyte receptor and the merozoite motor.


Assuntos
Genes de Protozoários , Proteínas de Membrana/química , Plasmodium falciparum/química , Proteínas de Protozoários/química , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Anticorpos Antiprotozoários/imunologia , Fenômenos Biofísicos , Cromatografia Líquida de Alta Pressão/métodos , Biologia Computacional , Eritrócitos/imunologia , Eritrócitos/parasitologia , Escherichia coli/química , Frutose-Bifosfato Aldolase/química , Humanos , Glicoproteínas de Membrana/química , Proteínas de Membrana/imunologia , Microscopia de Força Atômica , Pessoa de Meia-Idade , Dados de Sequência Molecular , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/imunologia , Ligação Proteica , Redobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas de Protozoários/imunologia , Ratos , Receptores Imunológicos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Ultracentrifugação , Adulto Jovem
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