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1.
Diabetes Care ; 47(6): 1056-1064, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639997

RESUMO

OBJECTIVE: We evaluated baseline characteristics of participants with early-onset type 2 diabetes (T2D) from the SURPASS program and tirzepatide's effects on glycemic control, body weight (BW), and cardiometabolic markers. RESEARCH DESIGN AND METHODS: This post hoc analysis compared baseline characteristics and changes in mean HbA1c, BW, waist circumference (WC), lipids, and blood pressure (BP) in 3,792 participants with early-onset versus later-onset T2D at week 40 (A Study of Tirzepatide [LY3298176] in Participants With Type 2 Diabetes Not Controlled With Diet and Exercise Alone [SURPASS-1] and A Study of Tirzepatide [LY3298176] Versus Semaglutide Once Weekly as Add-on Therapy to Metformin in Participants With Type 2 Diabetes [SURPASS-2]) or week 52 (A Study of Tirzepatide [LY3298176] Versus Insulin Degludec in Participants With Type 2 Diabetes [SURPASS-3]). Analyses were performed by study on data from participants while on assigned treatment without rescue medication in case of persistent hyperglycemia. RESULTS: At baseline in SURPASS-2, participants with early-onset versus later-onset T2D were younger with longer diabetes duration (9 vs. 7 years, P < 0.001) higher glycemic levels (8.5% vs. 8.2%, P < 0.001), higher BW (97 vs. 93 kg, P < 0.001) and BMI (35 vs. 34 kg/m2, P < 0.001), and a similarly abnormal lipid profile (e.g., triglycerides 167 vs. 156 mg/dL). At week 40, similar improvements in HbA1c (-2.6% vs. -2.4%), BW (-14 vs. -13 kg), WC (-10 vs. -10 cm), triglycerides (-26% vs. -24%), HDL (7% vs. 7%), and systolic BP (-6 vs. -7 mmHg) were observed in both subgroups with tirzepatide. CONCLUSIONS: Despite younger age, participants with early-onset T2D from the SURPASS program had higher glycemic levels and worse overall metabolic health at baseline versus those with later-onset T2D. In this post hoc analysis, similar improvements in HbA1c, BW, and cardiometabolic markers were observed with tirzepatide, irrespective of age at T2D diagnosis. Future studies are needed to determine long-term outcomes of tirzepatide in early-onset T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Hipoglicemiantes , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Hipoglicemiantes/uso terapêutico , Adulto , Hemoglobinas Glicadas/metabolismo , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Receptor do Peptídeo Semelhante ao Glucagon 2 , Polipeptídeo Inibidor Gástrico
3.
J Endocr Soc ; 7(5): bvad056, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-37153701

RESUMO

Context: Tirzepatide is a glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist approved for treatment of type 2 diabetes (T2D). SURPASS-1, a phase 3 trial of tirzepatide monotherapy in people with early T2D, enables evaluating effects of tirzepatide on pancreatic beta-cell function and insulin sensitivity (IS) without other background antihyperglycemic medications. Objective: Explore changes in biomarkers of beta-cell function and IS with tirzepatide monotherapy. Design: Post hoc analyses of fasting biomarkers with analysis of variance and mixed model repeated measures. Setting: Forty-seven sites in 4 countries. Patients: Four hundred seventy-eight T2D participants. Intervention: Tirzepatide (5, 10, 15 mg), placebo. Main Outcome Measures: Analyze biomarkers of beta-cell function and IS at 40 weeks. Results: At 40 weeks, markers of beta-cell function improved with tirzepatide monotherapy vs placebo with reductions from baseline in fasting proinsulin levels (49-55% vs -0.6%) and in intact proinsulin/C-peptide ratios (47-49% vs -0.1%) (P < .001, all doses vs placebo). Increases from baseline in homeostatic model assessment for beta-cell function (computed with C-peptide) (77-92% vs -1.4%) and decreases in glucose-adjusted glucagon levels (37-44% vs +4.8%) were observed with tirzepatide vs placebo (P < .001, all doses vs placebo). IS improved as indicated by reductions from baseline in homeostatic model assessment for insulin resistance (9-23% vs +14.7%) and fasting insulin levels (2-12% vs +15%), and increases in total adiponectin (16-23% vs -0.2%) and insulin-like growth factor binding protein 2 (38-70% vs +4.1%) with tirzepatide vs placebo at 40 weeks (P ≤ .031, all doses vs placebo, except for fasting insulin levels with tirzepatide 10 mg). Conclusions: As monotherapy for early T2D, tirzepatide achieved significant improvements in biomarkers of both pancreatic beta-cell function and IS.

4.
Diabetes Obes Metab ; 25(9): 2553-2560, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37246796

RESUMO

AIM: To assess the relationship between HbA1c and body weight reductions with tirzepatide treatment (5, 10 or 15 mg). MATERIALS AND METHODS: HbA1c and body weight data at 40 weeks (SURPASS-1, -2 and -5) and 52 weeks (SURPASS-3 and -4) were analysed by trial. RESULTS: Across the SURPASS clinical trials, HbA1c reductions from baseline were observed in 96%-99%, 98%-99% and 94%-99% of participants treated with tirzepatide 5, 10 and 15 mg, respectively. Moreover, 87%-94%, 88%-95% and 88%-97% of participants, respectively, experienced weight loss associated with HbA1c reductions. Statistically significant associations (correlation coefficients ranging from 0.1438 to 0.3130 across studies; P ≤ .038) between HbA1c and body weight changes were observed with tirzepatide in SURPASS-2, -3, -4 (all doses) and -5 (tirzepatide 5 mg only). CONCLUSIONS: In this post hoc analysis, consistent reductions in both HbA1c and body weight were observed in most participants treated with tirzepatide at doses of 5, 10 or 15 mg. A statistically significant but modest association between HbA1c and body weight change was observed in SURPASS-2, SURPASS-3 and SURPASS-4, suggesting that both weight-independent and weight-dependent mechanisms are responsible for the tirzepatide-induced improvement in glycaemic control.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas , Glicemia , Controle Glicêmico , Polipeptídeo Inibidor Gástrico/uso terapêutico , Redução de Peso , Hipoglicemiantes/uso terapêutico , Peso Corporal
5.
Diabetes Obes Metab ; 25(4): 965-974, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36514843

RESUMO

AIM: To assess composite endpoints combining glycaemic control (HbA1c < 7.0%, ≤ 6.5% or < 5.7%) with weight loss (≥ 5%, ≥ 10% or ≥ 15%) and without hypoglycaemia with tirzepatide in type 2 diabetes (T2D). MATERIALS AND METHODS: Data from the phase 3 SURPASS programme were evaluated post hoc by trial. Participants with T2D were randomized to tirzepatide (5, 10 and 15 mg), placebo (SURPASS-1,5), semaglutide 1 mg (SURPASS-2) or titrated basal insulin (SURPASS-3,4). The proportions of participants achieving the composite endpoints were compared between tirzepatide and the respective comparator groups at week 40/52. RESULTS: The proportions of participants achieving an HbA1c value of less than 7.0% with 5% or more weight loss and without hypoglycaemia ranged from 43% to 82% with tirzepatide across the SURPASS-1 to -5 trials versus 4%-5% with placebo, 51% with semaglutide 1 mg and 5% with basal insulin (P < .001 vs. all comparators). The proportions of participants achieving an HbA1c value of less than 7.0% with 10% or more, or 15% or more weight loss and without hypoglycaemia were significantly higher with all tirzepatide doses versus comparators across trials (P < .001 or P < .05). Similar results were observed for all other combinations of endpoints with an HbA1c value of 6.5% or less, or less than 5.7%, with more tirzepatide-treated participants achieving these endpoints versus those in the comparator groups, including semaglutide. CONCLUSIONS: Across the SURPASS-1 to -5 clinical trials, more tirzepatide-treated participants with T2D achieved clinically meaningful composite endpoints, which included reaching glycaemic targets with various degrees of weight loss and without hypoglycaemia, than those in the comparator groups.


Assuntos
Diabetes Mellitus Tipo 2 , Hipoglicemia , Insulinas , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hemoglobinas Glicadas , Redução de Peso , Hipoglicemia/tratamento farmacológico , Polipeptídeo Inibidor Gástrico/uso terapêutico , Glucose/uso terapêutico
6.
Lancet ; 398(10295): 143-155, 2021 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-34186022

RESUMO

BACKGROUND: Despite advancements in care, many people with type 2 diabetes do not meet treatment goals; thus, development of new therapies is needed. We aimed to assess efficacy, safety, and tolerability of novel dual glucose-dependent insulinotropic polypeptide and GLP-1 receptor agonist tirzepatide monotherapy versus placebo in people with type 2 diabetes inadequately controlled by diet and exercise alone. METHODS: We did a 40-week, double-blind, randomised, placebo-controlled, phase 3 trial (SURPASS-1), at 52 medical research centres and hospitals in India, Japan, Mexico, and the USA. Adult participants (≥18 years) were included if they had type 2 diabetes inadequately controlled by diet and exercise alone and if they were naive to injectable diabetes therapy. Participants were randomly assigned (1:1:1:1) via computer-generated random sequence to once a week tirzepatide (5, 10, or 15 mg), or placebo. All participants, investigators, and the sponsor were masked to treatment assignment. The primary endpoint was the mean change in glycated haemoglobin (HbA1c) from baseline at 40 weeks. This study is registered with ClinicalTrials.gov, NCT03954834. FINDINGS: From June 3, 2019, to Oct 28, 2020, of 705 individuals assessed for eligibility, 478 (mean baseline HbA1c 7·9% [63 mmol/mol], age 54·1 years [SD 11·9], 231 [48%] women, diabetes duration 4·7 years, and body-mass index 31·9 kg/m2) were randomly assigned to tirzepatide 5 mg (n=121 [25%]), tirzepatide 10 mg (n=121 [25%]), tirzepatide 15 mg (n=121 [25%]), or placebo (n=115 [24%]). 66 (14%) participants discontinued the study drug and 50 (10%) discontinued the study prematurely. At 40 weeks, all tirzepatide doses were superior to placebo for changes from baseline in HbA1c, fasting serum glucose, bodyweight, and HbA1c targets of less than 7·0% (<53 mmol/mol) and less than 5·7% (<39 mmol/mol). Mean HbA1c decreased from baseline by 1·87% (20 mmol/mol) with tirzepatide 5 mg, 1·89% (21 mmol/mol) with tirzepatide 10 mg, and 2·07% (23 mmol/mol) with tirzepatide 15 mg versus +0·04% with placebo (+0·4 mmol/mol), resulting in estimated treatment differences versus placebo of -1·91% (-21 mmol/mol) with tirzepatide 5 mg, -1·93% (-21 mmol/mol) with tirzepatide 10 mg, and -2·11% (-23 mmol/mol) with tirzepatide 15 mg (all p<0·0001). More participants on tirzepatide than on placebo met HbA1c targets of less than 7·0% (<53 mmol/mol; 87-92% vs 20%) and 6·5% or less (≤48 mmol/mol; 81-86% vs 10%) and 31-52% of patients on tirzepatide versus 1% on placebo reached an HbA1c of less than 5·7% (<39 mmol/mol). Tirzepatide induced a dose-dependent bodyweight loss ranging from 7·0 to 9·5 kg. The most frequent adverse events with tirzepatide were mild to moderate and transient gastrointestinal events, including nausea (12-18% vs 6%), diarrhoea (12-14% vs 8%), and vomiting (2-6% vs 2%). No clinically significant (<54 mg/dL [<3 mmol/L]) or severe hypoglycaemia were reported with tirzepatide. One death occurred in the placebo group. INTERPRETATION: Tirzepatide showed robust improvements in glycaemic control and bodyweight, without increased risk of hypoglycaemia. The safety profile was consistent with GLP-1 receptor agonists, indicating a potential monotherapy use of tirzepatide for type 2 diabetes treatment. FUNDING: Eli Lilly and Company.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Método Duplo-Cego , Polipeptídeo Inibidor Gástrico/uso terapêutico , Hipoglicemiantes/uso terapêutico , Peso Corporal/efeitos dos fármacos , Feminino , Hemoglobinas Glicadas/análise , Humanos , Índia , Japão , Masculino , Pessoa de Meia-Idade , América do Norte , Resultado do Tratamento
7.
Diabetes Obes Metab ; 20(8): 2023-2028, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29603872

RESUMO

Glucagon-like peptide-1 receptor agonists lower blood glucose in type 2 diabetes (T2D) partially through glucose-dependent stimulation of insulin secretion. The aim of this study was to investigate whether beta-cell function (as measured by HOMA2-%B) at baseline affects the glycaemic response to dulaglutide. Dulaglutide-treated patients from AWARD-1, AWARD-3 and AWARD-6 clinical studies were categorised based on their homeostatic model assessment of beta-cell function (HOMA2-%B) tertiles. Changes in glycaemic measures in response to treatment with once-weekly dulaglutide were evaluated in each HOMA2-%B tertile. Patients with low HOMA2-%B had higher baseline glycated haemoglobin (HbA1c), fasting and postprandial blood glucose, and longer duration of diabetes (P < .001, all) (mean low, middle and high tertiles with dulaglutide 1.5 mg: HOMAB-2%B, 31%, 58%, 109%; HbA1c, 8.7%, 7.7%, 7.3%, respectively). At 26 weeks, the low tertile experienced larger reductions in HbA1c compared to the high tertile with dulaglutide 1.5 mg (mean; -1.55% vs. -0.98% [-16.94 vs. -10.71 mmol/mol]). Differences between low and high tertiles disappeared when adjusted for baseline HbA1c (LSM; -1.00 vs. -1.18% [-10.93 vs. -12.90 mmol/mol]). Greater decreases in fasting blood glucose and greater increases in fasting C-peptide were observed in the low tertile. Similar increases in HOMA2-%B were observed in all tertiles. Dulaglutide demonstrated clinically relevant HbA1c reduction irrespective of estimated baseline beta-cell function.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Hiperglicemia/prevenção & controle , Hipoglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Fragmentos Fc das Imunoglobulinas/administração & dosagem , Resistência à Insulina , Proteínas Recombinantes de Fusão/administração & dosagem , Idoso , Biomarcadores/sangue , Peptídeo C/sangue , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Progressão da Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada , Feminino , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Peptídeos Semelhantes ao Glucagon/administração & dosagem , Peptídeos Semelhantes ao Glucagon/uso terapêutico , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/uso terapêutico , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes de Fusão/uso terapêutico
8.
Postgrad Med ; 128(8): 810-821, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27488824

RESUMO

Approximately 90% of T2D patients in the US are diagnosed and treated in the primary care setting, and the majority of the burden of disease management falls to primary care providers. Here, we discuss the clinical data for once weekly dulaglutide, e.g. the results of seven completed Phase 3 trials, patient preference studies, patient reported outcomes (PRO), and clinical data surrounding the dulaglutide administration device. Dulaglutide 1.5 mg once weekly demonstrated superiority to placebo, metformin, sitagliptin, exenatide BID, and insulin glargine (in 2 trials), and non-inferiority to liraglutide in reduction of HbA1c from baseline, with an acceptable safety profile. Dulaglutide-treated patients achieved the composite endpoint of an HbA1c <7.0% with no hypoglycemia, no severe hypoglycemia, and no weight gain significantly more than metformin, sitagliptin, exenatide BID or insulin glargine treated patients. Dulaglutide consistently showed an early onset of glycemic control, lasting up to 104 weeks. Additionally, PRO and patient preference data support the benefit of once weekly dulaglutide for the treatment of T2D.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Hipoglicemiantes/uso terapêutico , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Atenção Primária à Saúde , Proteínas Recombinantes de Fusão/uso terapêutico , Glicemia , Peso Corporal/efeitos dos fármacos , Ensaios Clínicos Fase III como Assunto , Quimioterapia Combinada , Peptídeos Semelhantes ao Glucagon/administração & dosagem , Peptídeos Semelhantes ao Glucagon/efeitos adversos , Peptídeos Semelhantes ao Glucagon/uso terapêutico , Hemoglobinas Glicadas , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Fragmentos Fc das Imunoglobulinas/administração & dosagem , Fragmentos Fc das Imunoglobulinas/efeitos adversos , Injeções Subcutâneas/instrumentação , Medidas de Resultados Relatados pelo Paciente , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos
9.
Eur J Clin Pharmacol ; 66(2): 127-35, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19888568

RESUMO

PURPOSE: Prasugrel is a novel thienopyridine prodrug metabolised to an active metabolite that binds irreversibly to the platelet P2Y(12) receptor and inhibits adenosine diphosphate (ADP)-induced platelet aggregation. We compared prasugrel pharmacokinetics, pharmacodynamics, and tolerability in healthy Chinese, Japanese, Korean and Caucasian subjects. METHODS: In an open-label, single-centre, parallel-design study, 89 healthy subjects (25 Chinese, 20 Japanese, 22 Korean and 22 Caucasian) aged 20-65 years were given a prasugrel 60-mg loading dose (LD) followed by daily 10-mg maintenance doses (MD) for 7 days and then 5-mg MD for 10 days. Plasma concentrations of prasugrel's active metabolite and inhibition of ADP-induced platelet aggregation (IPA) were determined. RESULTS: Mean exposure to prasugrel's active metabolite in all treatment regimens was higher in each of the Asian groups than in the Caucasian group, although there was considerable overlap between individual exposure estimates in Asians and Caucasians. The mean IPA was also higher in Asians than in Caucasians following a prasugrel 60-mg LD, although the difference did not consistently achieve statistical significance. Prasugrel 10-mg or 5-mg MD produced statistically significantly higher IPA in each Asian group compared with that in the Caucasians. Prasugrel was well tolerated during the LD and MD regimens by all groups. CONCLUSIONS: Mean exposure to the prasugrel active metabolite following prasugrel 60-mg LD and during daily 10-mg or 5-mg MD was higher in each of the Asian groups than in the Caucasian group, which resulted in greater platelet inhibition.


Assuntos
Piperazinas/farmacologia , Piperazinas/farmacocinética , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/farmacocinética , Pró-Fármacos/farmacologia , Pró-Fármacos/farmacocinética , Tiofenos/farmacologia , Tiofenos/farmacocinética , Difosfato de Adenosina/farmacologia , Adulto , Idoso , Povo Asiático , Índice de Massa Corporal , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Piperazinas/sangue , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/efeitos adversos , Cloridrato de Prasugrel , Pró-Fármacos/administração & dosagem , Pró-Fármacos/efeitos adversos , Estatística como Assunto , Tiofenos/administração & dosagem , Tiofenos/efeitos adversos , População Branca , Adulto Jovem
10.
Mol Cell Biol ; 28(2): 630-41, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17998336

RESUMO

Engagement of the T-cell antigen receptor (TCR) results in the proximal activation of the Src family tyrosine kinase Lck. The activation of Lck leads to the downstream activation of the Ras/Raf/MEK/ERK signaling pathway (where ERK is extracellular signal-related kinase). Under conditions of weak, but not strong, stimulation through the TCR, a version of Lck that contains a single point mutation in the SH3 (Src homology 3) domain (W97ALck) fails to support the activation of ERK, despite initiating signaling through the TCR, as demonstrated by the robust activation of ZAP-70, PLC-gamma, and Ras. We determined that the signaling lesion in W97ALck-expressing cells lies at the level of Raf-1 activation and is dependent on the presence of tyrosines 340/341 in the Raf-1 sequence. These data demonstrate a second function for Lck in TCR-mediated signaling to ERK. Additionally, we found that a significant fraction of Lck is localized to the Golgi apparatus and that, compared with wild-type Lck, W97ALck displays aberrant Golgi membrane localization. Our results support a model where under conditions of weak stimulation through the TCR, in addition to activated Ras, Golgi apparatus-localized Lck is needed for the full activation of Raf-1.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas Proto-Oncogênicas c-raf/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Complexo CD3/metabolismo , Ativação Enzimática , Regulação Enzimológica da Expressão Gênica , Complexo de Golgi/metabolismo , Humanos , Células Jurkat , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fosfolipase C gama/metabolismo , Fosforilação , Fosfosserina/metabolismo , Fosfotirosina/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-raf/genética , Especificidade por Substrato , Proteína-Tirosina Quinase ZAP-70/metabolismo , Domínios de Homologia de src
11.
J Immunol ; 177(10): 7203-10, 2006 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17082638

RESUMO

Bruton's tyrosine kinase (Btk) is a critical signaling mediator downstream of the B cell Ag receptor. X-linked agammaglobulinemia is caused by mutations in Btk resulting in multiple defects in B cell development and function, and recurrent bacterial infections. Recent evidence has also supported a role for Btk in TLR signaling. We demonstrate that Btk is activated by TLR4 in primary macrophages and is required for normal TLR-induced IL-10 production in multiple macrophage populations. Btk-deficient bone marrow-derived macrophages secrete decreased levels of IL-10 in response to multiple TLR ligands, compared with wild-type (WT) cells. Similarly, Btk-deficient peritoneal and splenic macrophages secrete decreased IL-10 levels compared with WT cultures. This phenotype correlates with Btk-dependent induction of NF-kappaB and AP-1 DNA binding activity, and altered commensal bacteria populations. Decreased IL-10 production may be responsible for increased IL-6 because blocking IL-10 in WT cultures increased IL-6 production, and supplementation of IL-10 to Btk-deficient cultures decreased IL-6 production. Similarly, injection of IL-10 in vivo with LPS decreases the elevated IL-6 serum levels during endotoxemia in Btk-deficient mice. These data further support a role for Btk in regulating TLR-induced cytokine production from APCs and provide downstream targets for analysis of Btk function.


Assuntos
Interleucina-10/biossíntese , Proteínas Tirosina Quinases/fisiologia , Receptores Toll-Like/fisiologia , Tirosina Quinase da Agamaglobulinemia , Animais , Bactérias Aeróbias/crescimento & desenvolvimento , Bactérias Aeróbias/imunologia , Células da Medula Óssea/enzimologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Regulação para Baixo/genética , Regulação para Baixo/imunologia , Homeostase/genética , Homeostase/imunologia , Interleucina-10/antagonistas & inibidores , Interleucina-10/metabolismo , Interleucina-6/biossíntese , Macrófagos/enzimologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Tirosina Quinases/deficiência , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Baço/citologia , Baço/enzimologia , Baço/imunologia , Receptor 4 Toll-Like/fisiologia , Receptores Toll-Like/antagonistas & inibidores , Receptores Toll-Like/metabolismo , Regulação para Cima/genética , Regulação para Cima/imunologia
12.
Immunity ; 22(6): 693-703, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15963784

RESUMO

Primary T helper 2 cells are heterogeneous, expressing subsets of cytokines at varying levels. Mechanisms controlling this spectrum of phenotypes are still unclear. The ETS family transcription factor PU.1 is expressed in Th2 but not Th1 cells. Th2 cytokine production is decreased in cultures transduced with a PU.1-expressing retrovirus and increased in Th2 cells following RNAi that decreases PU.1 expression. In primary cultures, PU.1 expression is restricted to a subpopulation of Th2 cells that express CCL22 and a subset of Th2 cytokines. PU.1 regulates the Th2 phenotype by interfering with GATA-3 DNA binding without altering GATA-3 protein levels. Thus, the expression of PU.1 in subsets of Th2 cells establishes a defined cytokine profile and contributes towards establishing the spectrum of cytokine production observed in Th2 populations.


Assuntos
Citocinas/biossíntese , Proteínas Proto-Oncogênicas/metabolismo , Células Th2/imunologia , Transativadores/metabolismo , Animais , Northern Blotting , Western Blotting , Células Cultivadas , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Citometria de Fluxo , Fator de Transcrição GATA3 , Imunoprecipitação , Camundongos , Camundongos Endogâmicos BALB C , Fenótipo , Proteínas Proto-Oncogênicas/imunologia , Interferência de RNA , Retroviridae , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Th1/imunologia , Células Th1/metabolismo , Células Th2/metabolismo , Transativadores/imunologia
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