Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Bioeng Transl Med ; 9(3): e10639, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38818122

RESUMO

Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) is an effective tumor treatment capable of eliciting an antitumor immune response. Motivated by the ability of PBNP-PTT to potentiate endogenous immune responses, we recently demonstrated that PBNP-PTT could be used ex vivo to generate tumor-specific T cells against glioblastoma (GBM) cell lines as an adoptive T cell therapy (ATCT). In this study, we further developed this promising T cell development platform. First, we assessed the phenotype and function of T cells generated using PBNP-PTT. We observed that PBNP-PTT facilitated CD8+ T cell expansion from healthy donor PBMCs that secreted IFNγ and TNFα and upregulated CD107a in response to engagement with target U87 cells, suggesting specific antitumor T cell activation and degranulation. Further, CD8+ effector and effector memory T cell populations significantly expanded after co-culture with U87 cells, consistent with tumor-specific effector responses. In orthotopically implanted U87 GBM tumors in vivo, PBNP-PTT-derived T cells effectively reduced U87 tumor growth and generated long-term survival in >80% of tumor-bearing mice by Day 100, compared to 0% of mice treated with PBS, non-specific T cells, or T cells expanded from lysed U87 cells, demonstrating an enhanced antitumor efficacy of this ATCT platform. Finally, we tested the generalizability of our approach by generating T cells targeting medulloblastoma (D556), breast cancer (MDA-MB-231), neuroblastoma (SH-SY5Y), and acute monocytic leukemia (THP-1) cell lines. The resulting T cells secreted IFNγ and exerted increased tumor-specific cytolytic function relative to controls, demonstrating the versatility of PBNP-PTT in generating tumor-specific T cells for ATCT.

2.
Front Cell Dev Biol ; 11: 1141738, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38089885

RESUMO

Plastin-3 (PLS3) is a calcium-sensitive actin-bundling protein that has recently been linked to the development of childhood-onset osteoporosis. Clinical data suggest that PLS3 mutations lead to a defect in osteoblast function, however the underlying mechanism remains elusive. To investigate the role of PLS3 in bone mineralization, we generated MC3T3-E1 preosteoblast cells that are stably depleted of PLS3. Analysis of osteogenic differentiation of control and PLS3 knockdown (PLS3 KD) cells showed that depletion of PLS3 does not alter the first stage of osteoblast mineralization in which a collagen matrix is deposited, but severely affects the subsequent mineralization of that matrix. During this phase, osteoblasts heavily rely on mechanosensitive signaling pathways to sustain mineral deposition in response to increasing stiffness of the extracellular matrix (ECM). PLS3 prominently localizes to focal adhesions (FAs), which are intricately linked to mechanosensation. In line with this, we observed that depletion of PLS3 rendered osteoblasts unresponsive to changes in ECM stiffness and showed the same cell size, FA lengths and number of FAs when plated on soft (6 kPa) versus stiff (100 kPa) substrates in contrast to control cells, which showed an increased in each of these parameters when plated on 100 kPa substrates. Defective cell spreading of PLS3 KD cells on stiff substrates could be rescued by expression of wildtype PLS3, but not by expression of three PLS3 mutations that were identified in patients with early onset osteoporosis and that have aberrant actin-bundling activity. Altogether, our results show that actin-bundling by PLS3 is part of the mechanosensitive mechanism that promotes osteoblast mineralization and thus begins to elucidate how PLS3 contributes to the development of bone defects such as osteoporosis.

3.
Contemp Clin Trials ; 131: 107273, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37380021

RESUMO

BACKGROUND: Oxaliplatin is a key chemotherapeutic agent in the treatment of local and metastatic gastrointestinal (GI) malignancies. Dose density and treatment adherence can be limited by chemotherapy-induced peripheral neuropathy (CIPN). Early research suggests CIPN incidence and severity may be mitigated by acupuncture, but rigorous data in GI oncology patients is limited. Here, we describe the protocol of a randomized, waitlist-controlled pilot study testing the use of preemptive of acupuncture plus acupressure to decrease CIPN and chemotherapy-related toxicities. METHODS: Patients with a GI malignancy (n = 56) with planned 5-fluorouracil (5-FU) and oxaliplatin IV (FOLFOX, FOLFIRINOX) every 2 weeks are being recruited. Additional concurrent anti-neoplastic agents may be used. Enrolled patients are randomized 1:1 to a 3-month intervention of Arm A: acupuncture with acupressure and standard-of-care treatment, or Arm B: standard-of-care alone. In Arm A, on days 1 and 3 of each chemotherapy cycle a standardized acupuncture protocol is administered and patients are taught self-acupressure to perform daily between chemotherapy treatments. Patients in both arms are given standard-of-care oral and peripheral (hands/feet) ice chip cryotherapy during oxaliplatin administration. CIPN and other symptoms are assessed at baseline, 6 weeks, and 3 months from registration. The primary endpoint is CIPN severity at 3 months (EORTC-CIPN 20). Additional endpoints evaluate CIPN incidence (CTCAE, Neuropen, tuning fork); incidence of pain, fatigue, nausea, oral dysesthesia, and anxiety; and feasibility (recruitment, retention, adherence, acceptability). If warranted, trial results will inform the design of a multi-center trial to expand testing of the intervention to a larger patient cohort.


Assuntos
Acupressão , Terapia por Acupuntura , Antineoplásicos , Neoplasias Gastrointestinais , Neoplasias Pancreáticas , Doenças do Sistema Nervoso Periférico , Humanos , Oxaliplatina/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Estudos de Viabilidade , Antineoplásicos/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/prevenção & controle , Terapia por Acupuntura/efeitos adversos , Terapia por Acupuntura/métodos , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/etiologia , Crioterapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
4.
Cytotherapy ; 25(7): 718-727, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37278683

RESUMO

BACKGROUND: Adoptive T cell therapy (ATCT) has been successful in treating hematological malignancies and is currently under investigation for solid-tumor therapy. In contrast to existing chimeric antigen receptor (CAR) T cell and/or antigen-specific T cell approaches, which require known targets, and responsive to the need for targeting a broad repertoire of antigens in solid tumors, we describe the first use of immunostimulatory photothermal nanoparticles to generate tumor-specific T cells. METHODS: Specifically, we subject whole tumor cells to Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) before culturing with dendritic cells (DCs), and subsequent stimulation of T cells. This strategy differs from previous approaches using tumor cell lysates because we use nanoparticles to mediate thermal and immunogenic cell death in tumor cells, rendering them enhanced antigen sources. RESULTS: In proof-of-concept studies using two glioblastoma (GBM) tumor cell lines, we first demonstrated that when PBNP-PTT was administered at a "thermal dose" targeted to induce the immunogenicity of U87 GBM cells, we effectively expanded U87-specific T cells. Further, we found that DCs cultured ex vivo with PBNP-PTT-treated U87 cells enabled 9- to 30-fold expansion of CD4+ and CD8+ T cells. Upon co-culture with target U87 cells, these T cells secreted interferon-É£ in a tumor-specific and dose-dependent manner (up to 647-fold over controls). Furthermore, T cells manufactured using PBNP-PTT ex vivo expansion elicited specific cytolytic activity against target U87 cells (donor-dependent 32-93% killing at an effector to target cell (E:T) ratio of 20:1) while sparing normal human astrocytes and peripheral blood mononuclear cells from the same donors. In contrast, T cells generated using U87 cell lysates expanded only 6- to 24-fold and killed 2- to 3-fold less U87 target cells at matched E:T ratios compared with T cell products expanded using the PBNP-PTT approach. These results were reproducible even when a different GBM cell line (SNB19) was used, wherein the PBNP-PTT-mediated approach resulted in a 7- to 39-fold expansion of T cells, which elicited 25-66% killing of the SNB19 cells at an E:T ratio of 20:1, depending on the donor. CONCLUSIONS: These findings provide proof-of-concept data supporting the use of PBNP-PTT to stimulate and expand tumor-specific T cells ex vivo for potential use as an adoptive T cell therapy approach for the treatment of patients with solid tumors.


Assuntos
Glioblastoma , Nanopartículas , Humanos , Leucócitos Mononucleares , Imunoterapia Adotiva/métodos , Linfócitos T CD8-Positivos , Glioblastoma/terapia , Linhagem Celular Tumoral
5.
Artigo em Inglês | MEDLINE | ID: mdl-37107735

RESUMO

BACKGROUND: During quit attempts, smokers must overcome smoking urges triggered by environmental cues and nicotine withdrawal symptoms. This study investigates the psychometric properties of the 12-item Tobacco Urge Management Scale (TUMS), a new measure of smoking urge management behaviors. METHODS: We analyzed secondary data (n = 327) from a behavioral smoking cessation intervention trial, Kids Safe and Smokefree (KiSS). RESULTS: Confirmatory factor analysis of the TUMS indicated that a one-factor model and a correlated two-factor model had similar model fit indices, and a Chi-square difference test supported the one-factor model. Further study of the parsimonious one-factor scale provided evidence of reliability and construct validity. Known group validity was evidenced by significantly higher TUMS scores in the KiSS intervention arm receiving urge management skills training than in the control arm (p < 0.001). Concurrent validity was evidenced by TUMS's inverse association with cigarettes smoked per day and positive associations with nonsmoking days, 7-day abstinence, and self-efficacy to control smoking behaviors (p's < 0.05). CONCLUSION: The TUMS is a reliable, valid measure of smoking urge management behaviors. The measure can support theory-driven research on smoking-specific coping mechanisms, inform clinical practice by identifying coping strategies that might be under-utilized in treatment-seeking smokers, and function as a measure of treatment adherence in cessation trials that target urge management behaviors.


Assuntos
Abandono do Hábito de Fumar , Psicometria , Reprodutibilidade dos Testes , Fumar
6.
J Biol Chem ; 298(11): 102518, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36152749

RESUMO

The great diversity in actin network architectures and dynamics is exploited by cells to drive fundamental biological processes, including cell migration, endocytosis, and cell division. While it is known that this versatility is the result of the many actin-remodeling activities of actin-binding proteins, such as Arp2/3 and cofilin, recent work also implicates posttranslational acetylation or arginylation of the actin N terminus itself as an equally important regulatory mechanism. However, the molecular mechanisms by which acetylation and arginylation alter the properties of actin are not well understood. Here, we directly compare how processing and modification of the N terminus of actin affects its intrinsic polymerization dynamics and its remodeling by actin-binding proteins that are essential for cell migration. We find that in comparison to acetylated actin, arginylated actin reduces intrinsic as well as formin-mediated elongation and Arp2/3-mediated nucleation. By contrast, there are no significant differences in cofilin-mediated severing. Taken together, these results suggest that cells can employ these differently modified actins to regulate actin dynamics. In addition, unprocessed actin with an N-terminal methionine residue shows very different effects on formin-mediated elongation, Arp2/3-mediated nucleation, and severing by cofilin. Altogether, this study shows that the nature of the N terminus of actin can promote distinct actin network dynamics, which can be differentially used by cells to locally finetune actin dynamics at distinct cellular locations, such as at the leading edge.


Assuntos
Fatores de Despolimerização de Actina , Actinas , Actinas/metabolismo , Forminas , Acetilação , Fatores de Despolimerização de Actina/metabolismo , Proteínas dos Microfilamentos/metabolismo , Citoesqueleto de Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo
7.
J Med Microbiol ; 71(4)2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35452382

RESUMO

Introduction. Evidence has linked exogenous and endogenous sex hormones with the human microbiome.Hypothesis/Gap statement. The longitudinal effects of oral contraceptives (OC) on the human gut microbiome have not previously been studied.Aim. We sought to examine the longitudinal impact of OC use on the taxonomic composition and metabolic functions of the gut microbiota and endogenous sex steroid hormones after initiation of OC use.Methodology. We recruited ten healthy women who provided blood and stool samples prior to OC use, 1 month and 6 months after starting OC. We measured serum levels of sex hormones, including estradiol, progesterone, sex hormone-binding globulin (SHBG), and total testosterone. Shotgun metagenomic sequencing was performed on DNA extracted from faecal samples. Species and metabolic pathway abundances were determined using MetaPhlAn2 and HUMAnN2. Multivariate association with linear models was used to identify microbial species and metabolic pathways associated with OC use and endogenous levels of sex hormones.Results. The percentage variance of the microbial community explained by individual factors ranged from 9.9 % for age to 2.7 % for time since initiation of OC use. We observed no changes in the diversity or composition of the gut microbiome following OC initiation. However, the relative abundance of the biosynthesis pathways of peptidoglycan, amino acids (lysine, threonine, methionine, and tryptophan), and the NAD salvage pathway increased after OC initiation. In addition, serum levels of estradiol and SHBG were positively associated with Eubacterium ramulus, a flavonoid-degrading bacterium. Similarly, microbes involving biosynthesis of l-lysine, l-threonine, and l-methionine were significantly associated with lower estradiol, SHBG, and higher levels of total testosterone.Conclusion. Our study provides the first piece of evidence supporting the association between exogenous and endogenous sex hormones and gut microbiome composition and function.


Assuntos
Microbioma Gastrointestinal , Pré-Escolar , Anticoncepcionais Orais/farmacologia , Estradiol , Feminino , Hormônios Esteroides Gonadais , Humanos , Testosterona
8.
Cell Rep ; 32(3): 107893, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32697999

RESUMO

Sarcomeres, the fundamental contractile units of muscles, are conserved structures composed of actin thin filaments and myosin thick filaments. How sarcomeres are formed and maintained is not well understood. Here, we show that knockdown of Drosophila cofilin (DmCFL), an actin depolymerizing factor, disrupts both sarcomere structure and muscle function. The loss of DmCFL also results in the formation of sarcomeric protein aggregates and impairs sarcomere addition during growth. The activation of the proteasome delays muscle deterioration in our model. Furthermore, we investigate how a point mutation in CFL2 that causes nemaline myopathy (NM) in humans affects CFL function and leads to the muscle phenotypes observed in vivo. Our data provide significant insights to the role of CFLs during sarcomere formation, as well as mechanistic implications for disease progression in NM patients.


Assuntos
Fatores de Despolimerização de Actina/metabolismo , Drosophila melanogaster/metabolismo , Desenvolvimento Muscular , Debilidade Muscular/metabolismo , Músculos/metabolismo , Músculos/patologia , Organogênese , Sarcômeros/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Sequência de Aminoácidos , Animais , Cofilina 2/química , Cofilina 2/genética , Técnicas de Silenciamento de Genes , Humanos , Miopatias da Nemalina/genética , Fenótipo , Mutação Puntual , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos , Tropomodulina/metabolismo , Troponina/metabolismo
9.
Cancer Prev Res (Phila) ; 13(10): 877-888, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32718943

RESUMO

Low-dose aspirin is recommended by the U.S. Preventive Services Task Force for primary prevention of colorectal cancer in certain individuals. However, broader implementation will require improved precision prevention approaches to identify those most likely to benefit. The major urinary metabolite of PGE2, 11α-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (PGE-M), is a biomarker for colorectal cancer risk, but it is unknown whether PGE-M is modifiable by aspirin in individuals at risk for colorectal cancer. Adults (N = 180) who recently underwent adenoma resection and did not regularly use aspirin or NSAIDs were recruited to a double-blind, placebo-controlled, randomized trial of aspirin at 81 or 325 mg/day for 8-12 weeks. The primary outcome was postintervention change in urinary PGE-M as measured by LC/MS. A total of 169 participants provided paired urine samples for analysis. Baseline PGE-M excretion was 15.9 ± 14.6 (mean ± S.D, ng/mg creatinine). Aspirin significantly reduced PGE-M excretion (-4.7 ± 14.8) compared with no decrease (0.8 ± 11.8) in the placebo group (P = 0.015; mean duration of treatment = 68.9 days). Aspirin significantly reduced PGE-M levels in participants receiving either 81 (-15%; P = 0.018) or 325 mg/day (-28%; P < 0.0001) compared with placebo. In 40% and 50% of the individuals randomized to 81 or 325 mg/day aspirin, respectively, PGE-M reduction reached a threshold expected to prevent recurrence in 10% of individuals. These results support that aspirin significantly reduces elevated levels of PGE-M in those at increased colorectal cancer risk to levels consistent with lower risk for recurrent neoplasia and underscore the potential utility of PGE-M as a precision chemoprevention biomarker. The ASPIRED trial is registered as NCT02394769.


Assuntos
Adenoma/patologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Neoplasias Colorretais/patologia , Dinoprostona/metabolismo , Adenoma/tratamento farmacológico , Adenoma/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Clin Gastroenterol Hepatol ; 18(4): 984-986, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31254673

RESUMO

The critical role of the gut microbiome in microscopic colitis (MC) is evident by the observation that fecal diversion is associated with resolution of mucosal inflammation while restoration of fecal stream is associated with recurrence of disease.1 Characterization of the composition and function of the gut microbiome in MC therefore could provide insights into disease pathogenesis.


Assuntos
Colite Microscópica , Colite , Microbioma Gastrointestinal , Colite Microscópica/diagnóstico , Disbiose , Fezes , Humanos
11.
Inflamm Bowel Dis ; 24(10): 2247-2257, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29788077

RESUMO

Background: Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized comorbidity in Crohn's disease (CD), but the mechanisms are poorly understood. Autophagy is a highly conserved process regulating innate immunity that contributes to CD susceptibility. Emerging data suggest that variants in the autophagy-governing IRGM gene may contribute to the accumulation of visceral adipose tissue (VAT) and hepatic fat. Our objective was to characterize the relationship between VAT, IRGM gene variants, and NAFLD risk in patients with CD. Methods: We included all CD patients in the Prospective Registry in Inflammatory Bowel Disease Study at Massachusetts General Hospital (PRISM) without history of alcohol abuse or liver disease. Hepatic fat was quantified by liver attenuation (LA) on computed tomography, with NAFLD defined by the validated liver:spleen (L:S) ratio. NAFLD severity was estimated by the FIB-4 Index and alanine aminotransferase (ALT). Using logistic regression modeling, we examined the relationship between VAT, autophagy gene variants, and NAFLD risk. Results: Among 462 patients, 52% had NAFLD. Increasing VAT quartile was associated with reduced LA (mean change, -7.43; 95% confidence interval [CI], -10.05 to -4.81; Ptrend < 0.0001). In the fully adjusted model, patients in the highest VAT quartile had a 2.2-fold increased NAFLD risk (95% CI, 1.21 to 4.14; Ptrend = 0.032) and a 4.2-fold increased risk of ALT>upper limit of normal (ULN) (95% CI, 1.19 to 14.76; Ptrend = 0.017). The relationship between VAT and NAFLD was modified by IRGM variants rs4958847 and rs13361189 (Pinteraction = 0.005 and Pinteraction < 0.001, respectively). Conclusions: In a large CD cohort, VAT was directly associated with prevalent NAFLD, and this relationship was augmented by functionally annotated IRGM variants associated with impaired autophagy.


Assuntos
Doença de Crohn/fisiopatologia , Proteínas de Ligação ao GTP/genética , Gordura Intra-Abdominal/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Polimorfismo de Nucleotídeo Único , Adulto , Feminino , Seguimentos , Predisposição Genética para Doença , Humanos , Masculino , Massachusetts/epidemiologia , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Prevalência , Prognóstico , Estudos Prospectivos
12.
Int J Colorectal Dis ; 33(3): 305-310, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29330765

RESUMO

PURPOSE: Pudendal nerve terminal motor latency (PNTML) testing is a standard recommendation for the evaluation of fecal incontinence. Its role in guiding therapy for fecal incontinence has been previously questioned. The aim of this study was to evaluate the relationship between PNTML testing and anorectal dysfunction. METHODS: This was a retrospective analysis of data collected prospectively from patients who presented to a pelvic floor disorder center from 2007 to 2015. The relationship between PNTML (normal versus delayed) and anorectal manometry, fecal incontinence severity, and fecal incontinence-related quality of life scores was assessed using the Wilcoxon-Mann-Whitney test. RESULTS: Two hundred sixty-nine patients underwent PNTML testing, and 91.1% were female (N = 245) (median age 62.2 years). Normal PNTML was seen in 234 (87.0%) patients. Among 268 patients who underwent anorectal manometry, delayed PNTML was only significantly associated with median maximum anal squeeze pressure (P = 0.04). Delayed PNTML was not associated with a decrease in median fecal incontinence severity or fecal incontinence-related quality of life scores (N = 99). CONCLUSIONS: PNTML was only associated with median maximum anal squeeze pressure, and it was not associated with patient-reported severity of symptoms of fecal incontinence, changes in quality of life attributable to fecal incontinence, median mean resting anal pressure, or median maximum resting anal pressure. PNTML testing may not be relevant to current therapeutic algorithms for fecal incontinence and its routine use should be questioned.


Assuntos
Incontinência Fecal/fisiopatologia , Incontinência Fecal/terapia , Atividade Motora , Nervo Pudendo/fisiopatologia , Tempo de Reação , Canal Anal/fisiopatologia , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Qualidade de Vida , Reto/fisiopatologia , Inquéritos e Questionários
14.
Inflamm Bowel Dis ; 23(11): 2035-2041, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28922252

RESUMO

BACKGROUND: A proportion of patients with initial presentation of ulcerative proctitis (UP) progress to more extensive colitis. We sought to characterize the natural history and identify clinical predictors of extension in UP. METHODS: We performed a retrospective cohort study of participants with a new diagnosis of UP from January 2000 to December 2015. We used Cox proportional hazard modeling to identify predictors of disease extension. RESULTS: We identified 169 new cases of UP with a median age of diagnosis of 40 years (range: 16-91 yr) and a median follow-up of 4.3 years (range: 3.3-15.1 yr). Fifty-three (31%) patients developed extension over the follow-up time. Compared with nonextenders, the need for immunosuppressive or biologic therapy was significantly higher among extenders (34% versus 2.6%, P < 0.001). In multivariable analyses, compared with UP cases with body mass index <25, the adjusted hazard ratios of extension were 1.75 (95% confidence interval [CI], 0.95-3.23) and 2.77 (95% CI, 1.07-7.14) among overweight and obese patients, respectively (Ptrend = 0.03). Similarly, patients with a history of appendectomy or endoscopic finding of moderate to severe disease had a higher risk of extension (adjusted hazard ratio = 2.74, 95% CI, 1.07-7.01 and 1.96, 95% CI, 1.05-3.67, respectively). CONCLUSIONS: In a retrospective cohort study, we show that appendectomy, body mass index, and endoscopic activity at the time of diagnosis of proctitis are associated with an increased risk of extension. In addition, our data suggest that extenders are more likely to require immunosuppressive or biologic therapy.


Assuntos
Colite Ulcerativa/tratamento farmacológico , Progressão da Doença , Imunossupressores/uso terapêutico , Proctite/tratamento farmacológico , Proctite/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Apendicectomia/efeitos adversos , Terapia Biológica , Índice de Massa Corporal , Endoscopia Gastrointestinal , Feminino , Seguimentos , Humanos , Masculino , Massachusetts , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
15.
Trials ; 18(1): 50, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28143522

RESUMO

BACKGROUND: Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties. METHODS/DESIGN: ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function. DISCUSSION: Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers. TRIAL REGISTRATION: This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769 . Registered on 16 March 2015.


Assuntos
Adenoma/tratamento farmacológico , Anticarcinógenos/administração & dosagem , Aspirina/administração & dosagem , Carcinoma/prevenção & controle , Neoplasias Colorretais/tratamento farmacológico , Adenoma/metabolismo , Adenoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticarcinógenos/efeitos adversos , Aspirina/efeitos adversos , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/urina , Boston , Carcinoma/metabolismo , Carcinoma/patologia , Protocolos Clínicos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Citocinas/sangue , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Prostaglandinas/urina , Fatores de Proteção , Projetos de Pesquisa , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
17.
J Mol Biol ; 428(8): 1604-16, 2016 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-26996939

RESUMO

Dynamic remodeling and turnover of cellular actin networks requires actin filament severing by actin-depolymerizing factor (ADF)/Cofilin proteins. Mammals express three different ADF/Cofilins (Cof1, Cof2, and ADF), and genetic studies suggest that in vivo they perform both overlapping and unique functions. To gain mechanistic insights into their different roles, we directly compared their G-actin and F-actin binding affinities, and quantified the actin filament severing activities of human Cof1, Cof2, and ADF using in vitro total internal reflection fluorescence microscopy. All three ADF/Cofilins had similar affinities for G-actin and F-actin. However, Cof2 and ADF severed filaments much more efficiently than Cof1 at both lower and higher concentrations and using either muscle or platelet actin. Furthermore, Cof2 and ADF were more effective than Cof1 in promoting "enhanced disassembly" when combined with actin disassembly co-factors Coronin-1B and actin-interacting protein 1 (AIP1), and these differences were observed on both preformed and actively growing filaments. To probe the mechanism underlying these differences, we used multi-wavelength total internal reflection fluorescence microscopy to directly observe Cy3-Cof1 and Cy3-Cof2 interacting with actin filaments in real time during severing. Cof1 and Cof2 each bound to filaments with similar kinetics, yet Cof2 induced severing much more rapidly than Cof1, decreasing the time interval between initial binding on a filament and severing at the same location. These differences in ADF/Cofilin activities and mechanisms may be used in cells to tune filament turnover rates, which can vary widely for different actin structures.


Assuntos
Citoesqueleto de Actina/química , Cofilina 1/química , Cofilina 2/química , Destrina/química , Microscopia/métodos , Fatores de Despolimerização de Actina/metabolismo , Actinas/química , Animais , Relação Dose-Resposta a Droga , Escherichia coli/metabolismo , Humanos , Nucleotídeos/química , Plasmídeos/metabolismo , Ligação Proteica , Coelhos
18.
Nat Commun ; 6: 7202, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25995115

RESUMO

The mechanisms by which cells destabilize and rapidly disassemble filamentous actin networks have remained elusive; however, Coronin, Cofilin and AIP1 have been implicated in this process. Here using multi-wavelength single-molecule fluorescence imaging, we show that mammalian Cor1B, Cof1 and AIP1 work in concert through a temporally ordered pathway to induce highly efficient severing and disassembly of actin filaments. Cor1B binds to filaments first, and dramatically accelerates the subsequent binding of Cof1, leading to heavily decorated, stabilized filaments. Cof1 in turn recruits AIP1, which rapidly triggers severing and remains bound to the newly generated barbed ends. New growth at barbed ends generated by severing was blocked specifically in the presence of all three proteins. This activity enabled us to reconstitute and directly visualize single actin filaments being rapidly polymerized by formins at their barbed ends while simultanteously being stochastically severed and capped along their lengths, and disassembled from their pointed ends.


Assuntos
Citoesqueleto de Actina/metabolismo , Cofilina 1/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo , Animais , Escherichia coli , Humanos , Camundongos , Microscopia de Fluorescência/métodos , Coelhos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA