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1.
Lancet Rheumatol ; 6(3): e168-e177, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301682

RESUMO

BACKGROUND: Mycophenolate mofetil is an immunosuppressant commonly used to treat systemic lupus erythematosus (SLE) and lupus nephritis. It is a known teratogen associated with significant toxicities, including an increased risk of infections and malignancies. Mycophenolate mofetil withdrawal is desirable once disease quiescence is reached, but the timing of when to do so and whether it provides a benefit has not been well-studied. We aimed to determine the effects of mycophenolate mofetil withdrawal on the risk of clinically significant disease reactivation in patients with quiescent SLE on long-term mycophenolate mofetil therapy. METHODS: This multicenter, open-label, randomised trial was conducted in 19 centres in the USA. Eligible patients were aged between 18 and 70 years old, met the American College of Rheumatology (ACR) 1997 SLE criteria, and had a clinical SLEDAI score of less than 4 at screening. Mycophenolate mofetil therapy was required to be stable or decreasing for 2 years or more if initiated for renal indications, or for 1 year or more for non-renal indications. Participants were randomly allocated in a 1:1 ratio to a withdrawal group, who tapered off mycophenolate mofetil over 12 weeks, or a maintenance group who maintained their baseline dose (1-3g per day) for 60 weeks. Adaptive random allocation ensured groups were balanced for study site, renal versus non-renal disease, and baseline mycophenolate mofetil dose (≥2 g per day vs <2 g per day). Clinically significant disease reactivation by week 60 following random allocation, requiring increased doses or new immunosuppressive therapy was the primary endpoint, in the modified intention-to-treat population (all randomly allocated participants who began study-provided mycophenolate mofetil). Non-inferiority was evaluated using an estimation-based approach. The trial was registered at ClinicalTrials.gov (NCT01946880) and is completed. FINDINGS: Between Nov 6, 2013, and April 27, 2018, 123 participants were screened, of whom 102 were randomly allocated to the maintenance group (n=50) or the withdrawal group (n=52). Of the 100 participants included in the modified intention-to-treat analysis (49 maintenance, 51 withdrawal), 84 (84%) were women, 16 (16%) were men, 40 (40%) were White, 41 (41%) were Black, and 76 (76%) had a history of lupus nephritis. The average age was 42 (SD 12·7). By week 60, nine (18%) of 51 participants in the withdrawal group had clinically significant disease reactivation, compared to five (10%) of 49 participants in the maintenance group. The risk of clinically significant disease reactivation was 11% (95% CI 5-24) in the maintenance group and 18% (10-32) in the withdrawal group. The estimated increase in the risk of clinically significant disease reactivation with mycophenolate mofetil withdrawal was 7% (one-sided upper 85% confidence limit 15%). Similar rates of adverse events were observed in the maintenance group (45 [90%] of 50 participants) and the withdrawal group (46 [88%] of 52 participants). Infections were more frequent in the mycophenolate mofetil maintenance group (32 [64%]) compared with the withdrawal group (24 [46%]). INTERPRETATIONS: Mycophenolate mofetil withdrawal is not significantly inferior to mycophenolate mofetil maintenance. Estimates for the rates of disease reactivation and increases in risk with withdrawal can assist clinicians in making informed decisions on withdrawing mycophenolate mofetil in patients with stable SLE. FUNDING: The National Institute of Allergy and Infectious Diseases and the National Institute of Arthritis and Musculoskeletal and Skin Diseases.


Assuntos
Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Masculino , Humanos , Feminino , Adulto , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso , Ácido Micofenólico/efeitos adversos , Nefrite Lúpica/tratamento farmacológico , Resultado do Tratamento , Imunossupressores/efeitos adversos , Lúpus Eritematoso Sistêmico/tratamento farmacológico
2.
JCI Insight ; 8(22)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37991020

RESUMO

Histone deacetylase (HDAC) inhibitors have garnered considerable interest for the treatment of adult and pediatric malignant brain tumors. However, owing to their broad-spectrum nature and inability to effectively penetrate the blood-brain barrier, HDAC inhibitors have failed to provide substantial clinical benefit to patients with glioblastoma (GBM) to date. Moreover, global inhibition of HDACs results in widespread toxicity, highlighting the need for selective isoform targeting. Although no isoform-specific HDAC inhibitors are currently available, the second-generation hydroxamic acid-based HDAC inhibitor quisinostat possesses subnanomolar specificity for class I HDAC isoforms, particularly HDAC1 and HDAC2. It has been shown that HDAC1 is the essential HDAC in GBM. This study analyzed the neuropharmacokinetic, pharmacodynamic, and radiation-sensitizing properties of quisinostat in preclinical models of GBM. It was found that quisinostat is a well-tolerated and brain-penetrant molecule that extended survival when administered in combination with radiation in vivo. The pharmacokinetic-pharmacodynamic-efficacy relationship was established by correlating free drug concentrations and evidence of target modulation in the brain with survival benefit. Together, these data provide a strong rationale for clinical development of quisinostat as a radiosensitizer for the treatment of GBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Adulto , Humanos , Criança , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/uso terapêutico , Histona Desacetilases/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Isoformas de Proteínas/metabolismo , Encéfalo/metabolismo
3.
Biomater Sci ; 10(3): 819-833, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34994746

RESUMO

Glioblastoma (GBM) brain tumors contain a subpopulation of self-renewing multipotent Glioblastoma stem-like cells (GSCs) that are believed to drive the near inevitable recurrence of GBM. We previously engineered temperature responsive scaffolds based on the polymer poly(N-isopropylacrylamide-co-Jeffamine M-1000 acrylamide) (PNJ) for the purpose of enriching GSCs in vitro from patient-derived samples. Here, we used PNJ scaffolds to study microenvironmental regulation of self-renewal and radiation response in patient-derived GSCs representing classical and proneural subtypes. GSC self-renewal was regulated by the composition of PNJ scaffolds and varied with cell type. PNJ scaffolds protected against radiation-induced cell death, particularly in conditions that also promoted GSC self-renewal. Additionally, cells cultured in PNJ scaffolds exhibited increased expression of the transcription factor HIF2α, which was not observed in neurosphere culture, providing a potential mechanistic basis for differences in radio-resistance. Differences in PNJ regulation of HIF2α in irradiated and untreated conditions also offered evidence of stem plasticity. These data show PNJ scaffolds provide a unique biomaterial for evaluating dynamic microenvironmental regulation of GSC self-renewal, radioresistance, and stem plasticity.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Linhagem Celular Tumoral , Humanos , Células-Tronco Neoplásicas
4.
JCI Insight ; 6(21)2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34747368

RESUMO

BackgroundIL-6 receptor (IL-6R) signaling drives development of T cell populations important to type 1 diabetes pathogenesis. We evaluated whether blockade of IL-6R with monoclonal antibody tocilizumab would slow loss of residual ß cell function in newly diagnosed type 1 diabetes patients.MethodsWe conducted a multicenter, randomized, placebo-controlled, double-blind trial with tocilizumab in new-onset type 1 diabetes. Participants were screened within 100 days of diagnosis. Eligible participants were randomized 2:1 to receive 7 monthly doses of tocilizumab or placebo. The primary outcome was the change from screening in the mean AUC of C-peptide collected during the first 2 hours of a mixed meal tolerance test at week 52 in pediatric participants (ages 6-17 years).ResultsThere was no statistical difference in the primary outcome between tocilizumab and placebo. Immunophenotyping showed reductions in downstream signaling of the IL-6R in T cells but no changes in CD4 memory subsets, Th17 cells, Tregs, or CD4+ T effector cell resistance to Treg suppression. A DC subset decreased during therapy but regressed to baseline once therapy stopped. Tocilizumab was well tolerated.ConclusionTocilizumab reduced T cell IL-6R signaling but did not modulate CD4+ T cell phenotypes or slow loss of residual ß cell function in newly diagnosed individuals with type 1 diabetes.Trial RegistrationClinicalTrials.gov NCT02293837.FundingNIH National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and National Institute of Allergy and Infectious Diseases (NIAID) UM1AI109565, UL1TR000004 from NIH/National Center for Research Resources (NCRR) Clinical and Translational Science Award (CTSA), NIH/NIDDK P30DK036836, NIH/NIDDK U01DK103266, NIH/NIDDK U01DK103266, 1UL1TR000064 from NIH/NCRR CTSA, NIH/National Center for Advancing Translational Sciences (NCATS) UL1TR001878, UL1TR002537 from NIH/CTSA; National Health and Medical Research Council Practitioner Fellowship (APP1136735), NIH/NIDDK U01-DK085476, NIH/CTSA UL1-TR002494, Indiana Clinical and Translational Science Institute Award UL1TR002529, Vanderbilt Institute for Clinical and Translational Research UL1TR000445. NIH/NCATS UL1TR003142, NIH/CTSA program UL1-TR002494, Veteran Affairs Administration, and 1R01AI132774.


Assuntos
Subpopulações de Linfócitos B/metabolismo , Diabetes Mellitus Tipo 1/genética , Receptores de Interleucina-6/antagonistas & inibidores , Adolescente , Criança , Diabetes Mellitus Tipo 1/patologia , Método Duplo-Cego , Feminino , Humanos , Masculino
5.
JAMA Dermatol ; 157(11): 1306-1315, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34643650

RESUMO

IMPORTANCE: Psoriasis relapse may involve compensatory T-cell activation pathways in the presence of CD28-CD80/CD86 blockade with abatacept. OBJECTIVE: To determine whether costimulatory signaling blockade with abatacept prevents psoriasis relapse after ustekinumab withdrawal. DESIGN, SETTING, AND PARTICIPANTS: Psoriasis Treatment with Abatacept and Ustekinumab: a Study of Efficacy (PAUSE), a parallel-design, double-blind, placebo-controlled randomized clinical trial, was conducted at 10 sites in the US and Canada. Participant enrollment opened on March 19, 2014, and concluded on April 11, 2016. Participants were adults with moderate to severe plaque psoriasis and received ustekinumab in a lead-in phase. Those who responded to ustekinumab at week 12 were randomized 1:1 to either the continued with ustekinumab group (ustekinumab group) or the switched to abatacept group (abatacept group). Treatment was discontinued at week 39, and participants were followed up for psoriasis relapse until week 88. Statistical analyses were performed in the intention-to-treat (ITT) and safety samples from May 3, 2018, to July 6, 2021. INTERVENTIONS: Participants received subcutaneous ustekinumab at weeks 0 and 4 (45 mg per dose for those ≤100 kg; 90 mg per dose for those >100 kg). Participants randomized to the abatacept group at week 12 received subcutaneous abatacept, 125 mg weekly, from weeks 12 to 39 and ustekinumab placebo at weeks 16 and 28. Participants randomized to the ustekinumab group received ustekinumab at weeks 16 and 28 and abatacept placebo weekly from weeks 12 to 39. MAIN OUTCOMES AND MEASURES: The primary end point was the proportion of participants with psoriasis relapse (loss of ≥50% of the initial Psoriasis Area and Severity Index improvement) between weeks 12 and 88. Secondary end points included time to psoriasis relapse, proportion of participants with psoriasis relapse between weeks 12 and 40, and adverse events. The psoriasis transcriptome and serum cytokines were evaluated. RESULTS: A total of 108 participants (mean [SD] age, 46.1 [12.1] years; 73 [67.6%] men) were treated with open-label ustekinumab; 91 were randomized to blinded treatment. Similar proportions of participants in the abatacept group and the ustekinumab group relapsed between weeks 12 and 88 (41 of 45 [91.1%] vs 40 of 46 [87.0%]; P = .41). Median time to relapse from the last dose of ustekinumab was similar between groups as well: 36 weeks (95% CI, 36-48 weeks) in the abatacept group vs 32 weeks (95% CI, 28-40 weeks) in the ustekinumab group. Similar numbers and rates of adverse events occurred. Abatacept did not maintain suppression of the pathogenic IL-23-mediated psoriasis molecular signature in lesions after ustekinumab withdrawal, and serum IL-19 levels increased. CONCLUSIONS AND RELEVANCE: This parallel-design, double-blind randomized clinical trial found that abatacept did not prevent psoriasis relapse that occurred after ustekinumab withdrawal because it did not completely block the pathogenic psoriasis molecular pathways that led to relapse. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01999868.


Assuntos
Psoríase , Ustekinumab , Abatacepte/efeitos adversos , Adulto , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Índice de Gravidade de Doença , Resultado do Tratamento , Ustekinumab/uso terapêutico
6.
JCI Insight ; 6(17)2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34494550

RESUMO

Glioblastoma (GBM) is characterized by an aberrant yet druggable epigenetic landscape. One major family of epigenetic regulators, the histone deacetylases (HDACs), are considered promising therapeutic targets for GBM due to their repressive influences on transcription. Although HDACs share redundant functions and common substrates, the unique isoform-specific roles of different HDACs in GBM remain unclear. In neural stem cells, HDAC2 is the indispensable deacetylase to ensure normal brain development and survival in the absence of HDAC1. Surprisingly, we find that HDAC1 is the essential class I deacetylase in glioma stem cells, and its loss is not compensated for by HDAC2. Using cell-based and biochemical assays, transcriptomic analyses, and patient-derived xenograft models, we find that knockdown of HDAC1 alone has profound effects on the glioma stem cell phenotype in a p53-dependent manner. We demonstrate marked suppression in tumor growth upon targeting of HDAC1 and identify compensatory pathways that provide insights into combination therapies for GBM. Our study highlights the importance of HDAC1 in GBM and the need to develop isoform-specific drugs.


Assuntos
DNA de Neoplasias/genética , Glioma/genética , Histona Desacetilase 1/genética , Mutação , Células-Tronco Neoplásicas/metabolismo , Apoptose , Perfilação da Expressão Gênica , Glioma/metabolismo , Glioma/patologia , Histona Desacetilase 1/metabolismo , Humanos , Isoformas de Proteínas/genética , Células Tumorais Cultivadas
7.
J Biol Chem ; 297(1): 100836, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34051236

RESUMO

Hypertrophic cardiomyopathy (HCM) is an inherited cardiovascular disorder primarily caused by mutations in the ß-myosin heavy-chain gene. The proximal subfragment 2 region (S2), 126 amino acids of myosin, binds with the C0-C2 region of cardiac myosin-binding protein-C to regulate cardiac muscle contractility in a manner dependent on PKA-mediated phosphorylation. However, it is unknown if HCM-associated mutations within S2 dysregulate actomyosin dynamics by disrupting its interaction with C0-C2, ultimately leading to HCM. Herein, we study three S2 mutations known to cause HCM: R870H, E924K, and E930Δ. First, experiments using recombinant proteins, solid-phase binding, and isothermal titrating calorimetry assays independently revealed that mutant S2 proteins displayed significantly reduced binding with C0-C2. In addition, CD revealed greater instability of the coiled-coil structure in mutant S2 proteins compared with S2Wt proteins. Second, mutant S2 exhibited 5-fold greater affinity for PKA-treated C0-C2 proteins. Third, skinned papillary muscle fibers treated with mutant S2 proteins showed no change in the rate of force redevelopment as a measure of actin-myosin cross-bridge kinetics, whereas S2Wt showed increased the rate of force redevelopment. In summary, S2 and C0-C2 interaction mediated by phosphorylation is altered by mutations in S2, which augment the speed and force of contraction observed in HCM. Modulating this interaction could be a potential strategy to treat HCM in the future.


Assuntos
Cardiomiopatia Hipertrófica/metabolismo , Proteínas de Transporte/metabolismo , Mutação/genética , Miosinas/genética , Animais , Bovinos , Humanos , Cinética , Camundongos Transgênicos , Proteínas Mutantes/metabolismo , Miosinas/metabolismo , Peptídeos/metabolismo , Fosforilação , Ligação Proteica , Reprodutibilidade dos Testes
8.
Proc Natl Acad Sci U S A ; 118(17)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33888578

RESUMO

Fast skeletal myosin-binding protein-C (fMyBP-C) is one of three MyBP-C paralogs and is predominantly expressed in fast skeletal muscle. Mutations in the gene that encodes fMyBP-C, MYBPC2, are associated with distal arthrogryposis, while loss of fMyBP-C protein is associated with diseased muscle. However, the functional and structural roles of fMyBP-C in skeletal muscle remain unclear. To address this gap, we generated a homozygous fMyBP-C knockout mouse (C2-/-) and characterized it both in vivo and in vitro compared to wild-type mice. Ablation of fMyBP-C was benign in terms of muscle weight, fiber type, cross-sectional area, and sarcomere ultrastructure. However, grip strength and plantar flexor muscle strength were significantly decreased in C2-/- mice. Peak isometric tetanic force and isotonic speed of contraction were significantly reduced in isolated extensor digitorum longus (EDL) from C2-/- mice. Small-angle X-ray diffraction of C2-/- EDL muscle showed significantly increased equatorial intensity ratio during contraction, indicating a greater shift of myosin heads toward actin, while MLL4 layer line intensity was decreased at rest, indicating less ordered myosin heads. Interfilament lattice spacing increased significantly in C2-/- EDL muscle. Consistent with these findings, we observed a significant reduction of steady-state isometric force during Ca2+-activation, decreased myofilament calcium sensitivity, and sinusoidal stiffness in skinned EDL muscle fibers from C2-/- mice. Finally, C2-/- muscles displayed disruption of inflammatory and regenerative pathways, along with increased muscle damage upon mechanical overload. Together, our data suggest that fMyBP-C is essential for maximal speed and force of contraction, sarcomere integrity, and calcium sensitivity in fast-twitch muscle.


Assuntos
Proteínas de Transporte/metabolismo , Contração Muscular/fisiologia , Fibras Musculares de Contração Rápida/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animais , Cálcio/metabolismo , Contração Isométrica/fisiologia , Camundongos , Força Muscular , Músculo Esquelético/metabolismo , Miofibrilas/metabolismo , Miosinas/metabolismo , Sarcômeros/metabolismo
9.
Dental press j. orthod. (Impr.) ; 25(5): 38-43, Sept.-Oct. 2020. tab, graf
Artigo em Inglês | LILACS, BBO | ID: biblio-1133687

RESUMO

ABSTRACT Objective: To evaluate a protocol for bonding metallic brackets after bleaching with hydrogen peroxide (HP). Methods: 60 extracted maxillary premolar were randomly divided into an unbleached control group and two groups bleached with a solution of 35% hydrogen peroxide prior to bonding. The teeth in one of the treated groups were bonded immediately after bleaching; while the other group was treated with 10% sodium ascorbate immediately after bleaching and before bonding. The teeth in all groups were stored in an artificial saliva solution for 7 days after bonding. The shear bond strength data was measured in megapascals (MPa) and the fail attempts were verified. The significance level was established at p< 0.05. Results: The unbleached group, in which brackets were bonded to untreated enamel, had the highest bond strength values (11.0 ± 5.7MPa) in comparison to the bleached group (7.14 ± 40MPa), in which brackets were bonded to recently bleached enamel. Slightly improved bond strength was observed in the antioxidant group (8.13 ± 5.4MPa), in which the teeth were bleached and then the antioxidant was applied to the teeth before bonding. Unbleached and bleached groups showed statistically significant difference for shear bond strength (p=0.03) and load strength (p=0.03); no significant differences were noted between unbleached and antioxidant groups (p=0.52). Conclusion: The antioxidant treatment applied immediately after bleaching was effective in reversing the reduction in shear bond strength of brackets after tooth bleaching.


RESUMO Objetivo: Avaliar um protocolo para colagem de braquetes metálicos após clareamento com peróxido de hidrogênio (PH). Método: Sessenta pré-molares superiores extraídos foram aleatoriamente divididos em um Grupo Controle (sem clareamento) e dois grupos que receberam clareamento, antes da colagem, com solução de peróxido de hidrogênio a 35%. Em um dos grupos tratados (Grupo Clareamento), os braquetes foram colados imediatamente após o clareamento, enquanto o outro (Grupo Antioxidante) foi tratado com ascorbato de sódio a 10%, imediatamente após o clareamento e antes da colagem. Os dentes, em todos os grupos, foram armazenados em saliva artificial por 7 dias após a colagem. As informações relativas à resistência da colagem foram registradas em megapascals (MPa) e as tentativas fracassadas foram verificadas. O nível de significância foi estabelecido em p < 0,05. Resultados: O Grupo Controle, no qual os braquetes foram colados ao esmalte não clareado, apresentou os valores mais altos de força de adesão (11,0 ± 5,7 MPa), em comparação ao Grupo Clareamento (7,14 ± 40 MPa), no qual os braquetes foram colados ao esmalte recém-clareado. Uma suave melhora na força de adesão foi observada no Grupo Antioxidante (8,13 ± 5,4 MPa), no qual, após os dentes serem clareados, foi aplicado antioxidante aos dentes, antes da colagem. Os Grupos Controle e Clareamento apresentaram uma diferença estatisticamente significativa para a resistência da colagem (p =0,03) e a resistência à carga (p= 0,03); porém, nenhuma diferença significativa foi notada entre os Grupos Controle e Antioxidante (p =0,52). Conclusão: O tratamento antioxidante aplicado imediatamente após o clareamento foi efetivo em reverter a diminuição da resistência da colagem dos braquetes após o clareamento dentário.


Assuntos
Clareamento Dental , Colagem Dentária , Braquetes Ortodônticos , Esmalte Dentário , Resistência ao Cisalhamento
10.
Rheumatology (Oxford) ; 59(4): 860-868, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31497844

RESUMO

OBJECTIVE: To address heterogeneity complicating primary SS (pSS) clinical trials, research and care by characterizing and clustering patients by their molecular phenotypes. METHODS: pSS patients met American-European Consensus Group classification criteria and had at least one systemic manifestation and stimulated salivary flow of ⩾0.1 ml/min. Correlated transcriptional modules were derived from gene expression microarray data from blood (n = 47 with appropriate samples). Patients were clustered based on this molecular information using an unbiased random forest modelling approach. In addition, multiplex, bead-based assays and ELISAs were used to assess 30 serum cytokines, chemokines and soluble receptors. Eleven autoantibodies, including anti-Ro/SSA and anti-La/SSB, were measured by Bio-Rad Bioplex 2200. RESULTS: Transcriptional modules distinguished three clusters of pSS patients. Cluster 1 showed no significant elevation of IFN or inflammation modules. Cluster 2 showed strong IFN and inflammation modular network signatures, as well as high plasma protein levels of IP-10/CXCL10, MIG/CXCL9, BLyS (BAFF) and LIGHT. Cluster 3 samples exhibited moderately elevated IFN modules, but with suppressed inflammatory modules, increased IP-10/CXCL10 and B cell-attracting chemokine 1/CXCL13 and trends toward increased MIG/CXCL9, IL-1α, and IL-21. Anti-Ro/SSA and anti-La/SSB were present in all three clusters. CONCLUSION: Molecular profiles encompassing IFN, inflammation and other signatures can be used to separate patients with pSS into distinct clusters. In the future, such profiles may inform patient selection for clinical trials and guide treatment decisions.


Assuntos
Expressão Gênica , Síndrome de Sjogren/genética , Adulto , Anticorpos Antinucleares/imunologia , Autoanticorpos/imunologia , Fator Ativador de Células B/genética , Fator Ativador de Células B/imunologia , Fator Ativador de Células B/metabolismo , Quimiocina CXCL10/genética , Quimiocina CXCL10/imunologia , Quimiocina CXCL10/metabolismo , Quimiocina CXCL13/genética , Quimiocina CXCL13/imunologia , Quimiocina CXCL13/metabolismo , Quimiocina CXCL9/genética , Quimiocina CXCL9/imunologia , Quimiocina CXCL9/metabolismo , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Redes Reguladoras de Genes , Humanos , Inflamação/genética , Inflamação/imunologia , Inflamação/metabolismo , Interferons/genética , Interferons/imunologia , Interferons/metabolismo , Interleucina-1alfa/genética , Interleucina-1alfa/imunologia , Interleucina-1alfa/metabolismo , Interleucinas/genética , Interleucinas/imunologia , Interleucinas/metabolismo , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fenótipo , Síndrome de Sjogren/classificação , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/metabolismo , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/imunologia , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo
11.
Proc Natl Acad Sci U S A ; 116(24): 11731-11736, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31142654

RESUMO

Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) accelerates cardiac contractility. However, the mechanisms by which cMyBP-C phosphorylation increases contractile kinetics have not been fully elucidated. In this study, we tested the hypothesis that phosphorylation of cMyBP-C releases myosin heads from the inhibited super-relaxed state (SRX), thereby determining the fraction of myosin available for contraction. Mice with various alanine (A) or aspartic acid (D) substitutions of the three main phosphorylatable serines of cMyBP-C (serines 273, 282, and 302) were used to address the association between cMyBP-C phosphorylation and SRX. Single-nucleotide turnover in skinned ventricular preparations demonstrated that phosphomimetic cMyBP-C destabilized SRX, whereas phospho-ablated cMyBP-C had a stabilizing effect on SRX. Strikingly, phosphorylation at serine 282 site was found to play a critical role in regulating the SRX. Treatment of WT preparations with protein kinase A (PKA) reduced the SRX, whereas, in nonphosphorylatable cMyBP-C preparations, PKA had no detectable effect. Mice with stable SRX exhibited reduced force production. Phosphomimetic cMyBP-C with reduced SRX exhibited increased rates of tension redevelopment and reduced binding to myosin. We also used recombinant myosin subfragment-2 to disrupt the endogenous interaction between cMyBP-C and myosin and observed a significant reduction in the population of SRX myosin. This peptide also increased force generation and rate of tension redevelopment in skinned fibers. Taken together, this study demonstrates that the phosphorylation-dependent interaction between cMyBP-C and myosin is a determinant of the fraction of myosin available for contraction. Furthermore, the binding between cMyBP-C and myosin may be targeted to improve contractile function.


Assuntos
Miosinas Cardíacas/metabolismo , Proteínas de Transporte/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Fosforilação/fisiologia , Animais , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas do Citoesqueleto/metabolismo , Cinética , Camundongos , Camundongos Transgênicos , Contração Miocárdica/fisiologia , Subfragmentos de Miosina/metabolismo , Sarcômeros/metabolismo
12.
Sci Transl Med ; 11(476)2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30674652

RESUMO

The mechanisms by which truncating mutations in MYBPC3 (encoding cardiac myosin-binding protein C; cMyBPC) or myosin missense mutations cause hypercontractility and poor relaxation in hypertrophic cardiomyopathy (HCM) are incompletely understood. Using genetic and biochemical approaches, we explored how depletion of cMyBPC altered sarcomere function. We demonstrated that stepwise loss of cMyBPC resulted in reciprocal augmentation of myosin contractility. Direct attenuation of myosin function, via a damaging missense variant (F764L) that causes dilated cardiomyopathy (DCM), normalized the increased contractility from cMyBPC depletion. Depletion of cMyBPC also altered dynamic myosin conformations during relaxation, enhancing the myosin state that enables ATP hydrolysis and thin filament interactions while reducing the super relaxed conformation associated with energy conservation. MYK-461, a pharmacologic inhibitor of myosin ATPase, rescued relaxation deficits and restored normal contractility in mouse and human cardiomyocytes with MYBPC3 mutations. These data define dosage-dependent effects of cMyBPC on myosin that occur across the cardiac cycle as the pathophysiologic mechanisms by which MYBPC3 truncations cause HCM. Therapeutic strategies to attenuate cMyBPC activity may rescue depressed cardiac contractility in patients with DCM, whereas inhibiting myosin by MYK-461 should benefit the substantial proportion of patients with HCM with MYBPC3 mutations.


Assuntos
Cardiomiopatia Hipertrófica/genética , Proteínas de Transporte/genética , Mutação/genética , Miosinas/metabolismo , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/metabolismo , Animais , Cardiomiopatia Hipertrófica/fisiopatologia , Modelos Animais de Doenças , Haploinsuficiência , Humanos , Camundongos , Contração Miocárdica , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Fenótipo , ortoaminobenzoatos/metabolismo
13.
Arthritis Rheumatol ; 71(3): 431-440, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30277008

RESUMO

OBJECTIVE: Adoptive Treg cell therapy has great potential to treat autoimmune disease. Currently, very little is known about how these cells impact inflamed tissues. This study was undertaken to elucidate how autologous Treg cell therapy influences tissue inflammation in human autoimmune disease. METHODS: We describe a systemic lupus erythematosus (SLE) patient with active skin disease who received adoptive Treg therapy. We comprehensively quantified Treg cells and immune activation in peripheral blood and skin, with data obtained at multiple time points posttreatment. RESULTS: Deuterium tracking of infused Treg cells revealed the transient presence of cells in peripheral blood, accompanied by increased percentages of highly activated Treg cells in diseased skin. Flow cytometric analysis and whole transcriptome RNA sequencing revealed that Treg cell accumulation in skin was associated with a marked attenuation of the interferon-γ pathway and a reciprocal augmentation of the interleukin-17 (IL-17) pathway. This phenomenon was more pronounced in skin relative to peripheral blood. To validate these findings, we investigated Treg cell adoptive transfer of skin inflammation in a murine model and found that it also resulted in a pronounced skewing away from Th1 immunity and toward IL-17 production. CONCLUSION: We report the first case of a patient with SLE treated with autologous adoptive Treg cell therapy. Taken together, our results suggest that this treatment leads to increased activated Treg cells in inflamed skin, with a dynamic shift from Th1 to Th17 responses.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Imunoterapia Adotiva/métodos , Lúpus Eritematoso Sistêmico/terapia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Pessoa de Meia-Idade , Linfócitos T Reguladores/imunologia
14.
Arch Biochem Biophys ; 660: 121-128, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30339776

RESUMO

The Myosin Binding Protein-C (MyBP-C) family is a group of sarcomeric proteins important for striated muscle structure and function. Comprising approximately 2% of the myofilament mass, MyBP-C has important roles in both contraction and relaxation. Three paralogs of MyBP-C are encoded by separate genes with distinct expression profiles in striated muscle. In mammals, cardiac MyBP-C is limited to the heart, and it is the most extensively studied owing to its involvement in cardiomyopathies. However, the roles of two skeletal paralogs, slow and fast, in muscle biology remain poorly characterized. Nonetheless, both have been recently implicated in the development of skeletal myopathies. This calls for a better understanding of their function in the pathophysiology of distal arthrogryposis. This review characterizes MyBP-C as a whole and points out knowledge gaps that still remain with respect to skeletal MyBP-C.


Assuntos
Proteínas de Transporte/metabolismo , Músculo Estriado/fisiologia , Actinas/metabolismo , Animais , Regulação da Expressão Gênica , Humanos , Músculo Estriado/metabolismo , Miosinas/metabolismo , Fosforilação
15.
Orthod Craniofac Res ; 21(4): 248-257, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30253035

RESUMO

OBJECTIVES: To compare the three-dimensional maxillary dentoskeletal effects of a modified alternate rapid maxillary expansion and constriction facemask protocol (Alt-RAMEC/FM) with the traditional rapid maxillary expansion facemask protocol (RME/FM) performed in deciduous or early mixed dentition Class III patients. SETTING AND SAMPLE POPULATION: Orthodontic Clinic of the Section of Dentistry of the Department of Surgery and Translational Medicine of the University of Florence. Thirty-four Class III patients were enrolled and allocated by alternating assignment to either Alt-RAMEC/FM or RME/FM therapy. MATERIALS AND METHODS: Prior to treatment, all patients were evaluated, and a cone beam computed tomography (CBCT) scan was acquired. After completion of the orthopaedic therapy (average interval 1.2 years), a follow-up CBCT scan was obtained. Anatomic landmark identification on the CBCTs and subsequent quantification of the changes were performed. The primary outcome variable was the anteroposterior displacement of the anterior nasal spine (ANS AP). The treatment groups were compared with independent samples t tests. RESULTS: The patients in the two treatment groups showed a similar degree of compliance. No statistically significant differences were recorded for any variable when comparing the Alt-RAMEC/FM and RME/FM groups. In particular, the between-group difference for ANS AP was 0.0 mm (95%CI: -0.6;0.7, P = 0.933). CONCLUSIONS: Both Alt-RAMEC/FM and RME/FM produced favourable orthopaedic changes in Class III growing patients. Neither protocol was superior to the other in terms of maxillary protraction effectiveness.


Assuntos
Imageamento Tridimensional/métodos , Má Oclusão Classe III de Angle/terapia , Maxila/diagnóstico por imagem , Ortopedia/normas , Pontos de Referência Anatômicos , Criança , Pré-Escolar , Tomografia Computadorizada de Feixe Cônico/métodos , Aparelhos de Tração Extrabucal , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Maxila/anatomia & histologia , Desenho de Aparelho Ortodôntico , Técnica de Expansão Palatina , Estudos Prospectivos , Técnicas de Movimentação Dentária/métodos
16.
Arthritis Rheumatol ; 70(9): 1470-1480, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29604186

RESUMO

OBJECTIVE: To evaluate the clinical efficacy and safety of baminercept, a lymphotoxin ß receptor IgG fusion protein (LTßR-Ig), for the treatment of primary Sjögren's syndrome (SS), and to explore the possible mechanisms of action of this treatment. METHODS: In this multicenter trial, 52 patients with primary SS were randomized in a 2:1 ratio to receive subcutaneous injections of 100 mg of baminercept every week for 24 weeks or matching placebo. The primary end point was the change between screening and week 24 in the stimulated whole salivary flow (SWSF) rate. Secondary end points included the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI), as well as measurements of select chemokines and cytokines and enumeration of peripheral blood B and T cell subsets. RESULTS: The change from baseline to week 24 in the SWSF rate was not significantly different between the baminercept and placebo treatment groups (baseline-adjusted mean change -0.01 versus 0.07 ml/minute; P = 0.332). The change in the ESSDAI during treatment was also not significantly different between the treatment groups (baseline-adjusted mean change -1.23 versus -0.15; P = 0.104). Although the incidence of adverse events was similar between the treatment groups, baminercept therapy was associated with a higher incidence of liver toxicity, including 2 serious adverse events. Baminercept also produced a significant decrease in plasma levels of CXCL13 and significant changes in the number of circulating B and T cells, consistent with its known inhibitory effects on LTßR signaling. CONCLUSION: In this trial, treatment with baminercept failed to significantly improve glandular and extraglandular disease in patients with primary SS, despite evidence from mechanistic studies showing that it blocks LTßR signaling.


Assuntos
Proteínas Recombinantes de Fusão/uso terapêutico , Síndrome de Sjogren/tratamento farmacológico , Adulto , Idoso , Linfócitos B/efeitos dos fármacos , Quimiocina CXCL13/sangue , Método Duplo-Cego , Feminino , Humanos , Receptor beta de Linfotoxina/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes de Fusão/imunologia , Síndrome de Sjogren/sangue , Síndrome de Sjogren/imunologia , Linfócitos T/efeitos dos fármacos , Resultado do Tratamento
17.
Mol Ther Nucleic Acids ; 8: 542-557, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28918054

RESUMO

A challenge for circulating tumor cell (CTC)-based diagnostics is the development of simple and inexpensive methods that reliably detect the diverse cells that make up CTCs. CTC-derived nucleases are one category of proteins that could be exploited to meet this challenge. Advantages of nucleases as CTC biomarkers include: (1) their elevated expression in many cancer cells, including cells implicated in metastasis that have undergone epithelial-to-mesenchymal transition; and (2) their enzymatic activity, which can be exploited for signal amplification in detection methods. Here, we describe a diagnostic assay based on quenched fluorescent nucleic acid probes that detect breast cancer CTCs via their nuclease activity. This assay exhibited robust performance in distinguishing breast cancer patients from healthy controls, and it is rapid, inexpensive, and easy to implement in most clinical labs. Given its broad applicability, this technology has the potential to have a substantive impact on the diagnosis and treatment of many cancers.

18.
Biomaterials ; 143: 149-158, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28802102

RESUMO

Glioblastoma (GBM) is the most common adult primary brain tumor, and the 5-year survival rate is less than 5%. GBM malignancy is driven in part by a population of GBM stem-like cells (GSCs) that exhibit indefinite self-renewal capacity, multipotent differentiation, expression of neural stem cell markers, and resistance to conventional treatments. GSCs are enriched in specialized niche microenvironments that regulate stem phenotypes and support GSC radioresistance. Therefore, identifying GSC-niche interactions that regulate stem phenotypes may present a unique target for disrupting the maintenance and persistence of this treatment resistant population. In this work, we engineered 3D scaffolds from temperature responsive poly(N-isopropylacrylamide-co-Jeffamine M-1000® acrylamide), or PNJ copolymers, as a platform for enriching stem-specific phenotypes in two molecularly distinct human patient-derived GSC cell lines. Notably, we observed that, compared to conventional neurosphere cultures, PNJ cultured GSCs maintained multipotency and exhibited enhanced self-renewal capacity. Concurrent increases in expression of proteins known to regulate self-renewal, invasion, and stem maintenance in GSCs (NESTIN, EGFR, CD44) suggest that PNJ scaffolds effectively enrich the GSC population. We further observed that PNJ cultured GSCs exhibited increased resistance to radiation treatment compared to GSCs cultured in standard neurosphere conditions. GSC radioresistance is supported in vivo by niche microenvironments, and this remains a significant barrier to effectively treating these highly tumorigenic cells. Taken in sum, these data indicate that the microenvironment created by synthetic PNJ scaffolds models niche enrichment of GSCs in patient-derived GBM cell lines, and presents tissue engineering opportunities for studying clinically important behaviors such as radioresistance in vitro.


Assuntos
Resinas Acrílicas/química , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Células-Tronco Neoplásicas/patologia , Alicerces Teciduais/química , Microambiente Tumoral , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Linhagem Celular Tumoral , Autorrenovação Celular , Humanos , Células Tumorais Cultivadas
19.
PLoS One ; 12(6): e0180064, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28658286

RESUMO

The "super-relaxed state" (SRX) of myosin represents a 'reserve' of motors in the heart. Myosin heads in the SRX are bound to the thick filament and have a very low ATPase rate. Changes in the SRX are likely to modulate cardiac contractility. We previously demonstrated that the SRX is significantly reduced in mouse cardiomyocytes lacking cardiac myosin binding protein-C (cMyBP-C). Here, we report the effect of mutations in the cMyBP-C gene (MYBPC3) using samples from human patients with hypertrophic cardiomyopathy (HCM). Left ventricular (LV) samples from 11 HCM patients were obtained following myectomy surgery to relieve LV outflow tract obstruction. HCM samples were genotyped as either MYBPC3 mutation positive (MYBPC3mut) or negative (HCMsmn) and were compared to eight non-failing donor hearts. Compared to donors, only MYBPC3mut samples display a significantly diminished SRX, characterised by a decrease in both the number of myosin heads in the SRX and the lifetime of ATP turnover. These changes were not observed in HCMsmn samples. There was a positive correlation (p < 0.01) between the expression of cMyBP-C and the proportion of myosin heads in the SRX state, suggesting cMyBP-C modulates and maintains the SRX. Phosphorylation of the myosin regulatory light chain in MYBPC3mut samples was significantly decreased compared to the other groups, suggesting a potential mechanism to compensate for the diminished SRX. We conclude that by altering both contractility and sarcomeric energy requirements, a reduced SRX may be an important disease mechanism in patients with MYBPC3 mutations.


Assuntos
Cardiomiopatia Hipertrófica/genética , Proteínas de Transporte/genética , Adolescente , Adulto , Proteínas de Transporte/fisiologia , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Relaxamento Muscular/genética , Relaxamento Muscular/fisiologia , Mutação/genética , Contração Miocárdica/genética , Contração Miocárdica/fisiologia , Miócitos Cardíacos/fisiologia , Miosinas/metabolismo , Miosinas/fisiologia , Adulto Jovem
20.
Clin Cancer Res ; 19(5): 1054-62, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23460536

RESUMO

The paucity of costimulation at the tumor site compromises the ability of tumor-specific T cells to eliminate the tumor. The recent U.S. Food and Drug Administration approval of ipilumimab, an antibody that blocks the inhibitory action of CTLA-4, and clinical trials targeting 4-1BB and PD-1 or PD-L1, have underscored the therapeutic potential of using immunomodulatory antibodies to stimulate protective immunity in human patients. Nonetheless, systemic administration of immunomodulatory antibodies has been associated with dose-limiting autoimmune pathologies, conceivably reflecting also the activation of resident autoreactive T cells. Arguably, targeting immunomodulatory ligands to the disseminated tumor lesions of the patient would reduce such drug-associated toxicities. We have recently developed a new class of inhibitory (CTLA-4) and agonistic (4-1BB and OX-40) ligands composed of short oligonucleotide (ODN) aptamers that exhibited bioactivities comparable or superior to that of antibodies. To reduce toxicity, the immunomodulatory aptamers were targeted to the tumor by conjugation to a second aptamer that bound to a product expressed on the surface of the tumor cell, the targeting aptamer, generating a bispecific aptamer conjugate analogous to bispecific antibodies. In a proof-of-concept study in mice, we have shown that an agonistic 4-1BB-binding aptamer conjugated to a prostate-specific membrane antigen (PSMA)-binding aptamer led to the inhibition of PSMA-expressing tumors, was more effective than, and synergized with, vaccination, and exhibited a superior therapeutic index compared with nontargeted costimulation with 4-1BB antibodies or 4-1BB aptamers. The cell-free chemically synthesized ODN aptamers offer significant advantages over antibodies in terms of synthesis, cost, as well as conjugation chemistry needed to generate bispecific ligand fusions.


Assuntos
Aptâmeros de Nucleotídeos/farmacologia , Fatores Imunológicos/imunologia , Neoplasias/imunologia , Receptores Imunológicos/imunologia , Animais , Humanos , Camundongos , Neoplasias/metabolismo , Neoplasias/terapia , Receptores Imunológicos/metabolismo
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