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1.
BMC Pulm Med ; 24(1): 348, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39026320

RESUMO

BACKGROUND: Outcomes for individuals with cystic fibrosis (CF) have improved due to highly effective modulator therapy (HEMT). However, lung transplant (LTx) remains an important treatment for people with advanced lung disease. This study assessed attitudes and knowledge about LTx in the HEMT era. METHODS: All patients from the University of Washington CF clinic were surveyed March 25-May 30, 2020. Questions addressed self-rated LTx preparedness and knowledge, as well as barriers and facilitators to discussing LTx. Demographic and clinical data were extracted from the electronic health record. RESULTS: There were 159/224 (71%) responses. Respondents had a median forced expiratory volume in one second (FEV1) of 70%, and 142 (89%) were on modulatory therapy. One hundred thirteen (71%) respondents felt that it was moderately or very important to be prepared to make decisions about LTx, though only 56 (35%) felt moderately or very prepared. Only 83 (30%) and 47 (52%) participants correctly answered questions about life expectancy and improved quality of life after LTx, respectively. Respondents with Medicaid insurance less frequently answered questions correctly. The most common barriers to discussing LTx were fear of being a burden on loved ones for 58 respondents (36%) and cost of LTx for 46 (29%). Most participants (94%) trusted their CF doctor, and 75% of participants selected trust as a facilitator for LTx discussions. CONCLUSIONS: Many individuals with CF, especially those with lower socioeconomic status, lacked knowledge and did not feel very prepared for decisions about LTx. Earlier education and discussions about LTx represent an area for improvement in CF care.


Assuntos
Fibrose Cística , Conhecimentos, Atitudes e Prática em Saúde , Transplante de Pulmão , Humanos , Fibrose Cística/cirurgia , Fibrose Cística/psicologia , Masculino , Feminino , Adulto , Inquéritos e Questionários , Qualidade de Vida , Pessoa de Meia-Idade , Adulto Jovem
3.
J Am Geriatr Soc ; 72(8): 2500-2507, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38593240

RESUMO

BACKGROUND: Documenting goals of care in the electronic health record is meant to relay patient preferences to other clinicians. Evaluating the content and documentation of nurse and social worker led goals of care conversations can inform future goals of care initiative efforts. METHODS: As part of the ADvancing symptom Alleviation with Palliative Treatment trial, this study analyzed goals of care conversations led by nurses and social workers and documented in the electronic health record. Informed by a goals of care communication guide, we identified five goals of care components: illness understanding, goals and values, end of life planning, surrogate, and advance directives. Forty conversation transcripts underwent content analysis. Through an iterative team process, we defined documentation accuracy as four categories: (1) Complete-comprehensive accurate documentation of the conversation, (2) Incomplete-partial documentation of the conversation, (3) Missing-discussed and not documented, and (4) Incorrect-misrepresented in documentation. We also defined-Not Discussed-for communication guide questions that were not discussed nor documented. A constant comparative approach was used to determine the presence or absence of conversation content in the documentation. RESULTS: All five goals of care components were discussed in 67% (27/40) of conversation transcripts. Compared to the transcripts, surrogate (37/40, 93%) and advance directives (36/40, 90%) were often documented completely. Almost 40% of goals and values (15/40, 38%) and half of end of life planning (19/40, 48%) were incomplete. Illness understanding was missing (13/40, 33%), not discussed (13/40, 33%), or incorrect (2/40, 5%). CONCLUSION: Nurse and social worker led goals of care conversations discussed and documented most components of the goals of care communication guide. Further research may guide how best to determine the relative importance of accuracy, especially in the broad setting of incomplete, missing, and incorrect EHR documentation.


Assuntos
Comunicação , Documentação , Registros Eletrônicos de Saúde , Planejamento de Assistência ao Paciente , Humanos , Documentação/normas , Documentação/métodos , Feminino , Masculino , Idoso , Diretivas Antecipadas , Cuidados Paliativos , Assistentes Sociais , Assistência Terminal/normas
4.
JAMA ; 331(3): 212-223, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38227034

RESUMO

Importance: Many patients with chronic obstructive pulmonary disease (COPD), heart failure (HF), and interstitial lung disease (ILD) endure poor quality of life despite conventional therapy. Palliative care approaches may benefit this population prior to end of life. Objective: Determine the effect of a nurse and social worker palliative telecare team on quality of life in outpatients with COPD, HF, or ILD compared with usual care. Design, Setting, and Participants: Single-blind, 2-group, multisite randomized clinical trial with accrual between October 27, 2016, and April 2, 2020, in 2 Veterans Administration health care systems (Colorado and Washington), and including community-based outpatient clinics. Outpatients with COPD, HF, or ILD at high risk of hospitalization or death who reported poor quality of life participated. Intervention: The intervention involved 6 phone calls with a nurse to help with symptom management and 6 phone calls with a social worker to provide psychosocial care. The nurse and social worker met weekly with a study primary care and palliative care physician and as needed, a pulmonologist, and cardiologist. Usual care included an educational handout developed for the study that outlined self-care for COPD, ILD, or HF. Patients in both groups received care at the discretion of their clinicians, which could include care from nurses and social workers, and specialists in cardiology, pulmonology, palliative care, and mental health. Main Outcomes and Measures: The primary outcome was difference in change in quality of life from baseline to 6 months between the intervention and usual care groups (FACT-G score range, 0-100, with higher scores indicating better quality of life, clinically meaningful change ≥4 points). Secondary quality-of-life outcomes at 6 months included disease-specific health status (Clinical COPD Questionnaire; Kansas City Cardiomyopathy Questionnaire-12), depression (Patient Health Questionnaire-8) and anxiety (Generalized Anxiety Disorder-7) symptoms. Results: Among 306 randomized patients (mean [SD] age, 68.9 [7.7] years; 276 male [90.2%], 30 female [9.8%]; 245 White [80.1%]), 177 (57.8%) had COPD, 67 (21.9%) HF, 49 (16%) both COPD and HF, and 13 (4.2%) ILD. Baseline FACT-G scores were similar (intervention, 52.9; usual care, 52.7). FACT-G completion was 76% (intervention, 117 of 154; usual care, 116 of 152) at 6 months for both groups. Mean (SD) length of intervention was 115.1 (33.4) days and included a mean of 10.4 (3.3) intervention calls per patient. In the intervention group, 112 of 154 (73%) patients received the intervention as randomized. At 6 months, mean FACT-G score improved 6.0 points in the intervention group and 1.4 points in the usual care group (difference, 4.6 points [95% CI, 1.8-7.4]; P = .001; standardized mean difference, 0.41). The intervention also improved COPD health status (standardized mean difference, 0.44; P = .04), HF health status (standardized mean difference, 0.41; P = .01), depression (standardized mean difference, -0.50; P < .001), and anxiety (standardized mean difference, -0.51; P < .001) at 6 months. Conclusions and Relevance: For adults with COPD, HF, or ILD who were at high risk of death and had poor quality of life, a nurse and social worker palliative telecare team produced clinically meaningful improvements in quality of life at 6 months compared with usual care. Trial Registration: ClinicalTrials.gov Identifier: NCT02713347.


Assuntos
Insuficiência Cardíaca , Pneumopatias , Cuidados Paliativos , Equipe de Assistência ao Paciente , Telemedicina , Adulto , Idoso , Feminino , Humanos , Masculino , Insuficiência Cardíaca/enfermagem , Insuficiência Cardíaca/terapia , Doenças Pulmonares Intersticiais/enfermagem , Doenças Pulmonares Intersticiais/terapia , Qualidade de Vida , Método Simples-Cego , Assistentes Sociais , Telemedicina/métodos , Papel do Profissional de Enfermagem , Cuidados Paliativos/métodos , Doença Pulmonar Obstrutiva Crônica/enfermagem , Doença Pulmonar Obstrutiva Crônica/terapia , Equipe de Assistência ao Paciente/organização & administração , Assistência Terminal/métodos , Assistência Ambulatorial/métodos , Serviços de Saúde para Veteranos Militares , Pneumopatias/enfermagem , Pneumopatias/terapia , Enfermeiras e Enfermeiros
5.
J Pain Symptom Manage ; 67(6): e891-e905, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38280439

RESUMO

CONTEXT: Use of palliative care interventions in chronic obstructive pulmonary disease (COPD) has increased in recent years and inclusion criteria used to identify patients with COPD appropriate for palliative care vary widely. We evaluated the inclusion criteria to identify ways to improve enrollment opportunities for patients with COPD. OBJECTIVES: To determine inclusion criteria used to select patients with COPD for palliative care trials. METHODS: A systematic review was conducted to determine criteria used to select patients with COPD for palliative care randomized controlled trials. A narrative synthesis was conducted for all trials. RESULTS: Inclusion criteria were highly heterogeneous. Most studies (n = 11, 79%) used a combination of criteria to identify patients with COPD. Commonly used criteria included hospitalization for an acute exacerbation of COPD (n = 8, 57%), home supplemental oxygen use (n = 8, 57%), and spirometry values confirming COPD (n = 6, 43%). Three studies (21.4%) used Modified Medical Research Council score and two studies (21%) used physician prognosis or a performance scale. CONCLUSION: The most common criteria, a hospitalization for acute exacerbation of COPD or supplemental oxygen use at home, both have the benefit of selecting patients who have a higher symptom burden or higher healthcare utilization who might therefore benefit more from palliative care. By describing the landscape and variability of previously used inclusion criteria, this article serves as a resource for clinicians and researchers. Developing a consistent set of inclusion criteria in the future would help generate generalizable results that can be translated into clinical practice to improve the lives of patients with COPD. PROSPERO REGISTRATION NUMBER: CRD42022306752.


Assuntos
Cuidados Paliativos , Seleção de Pacientes , Doença Pulmonar Obstrutiva Crônica , Ensaios Clínicos Controlados Aleatórios como Assunto , Doença Pulmonar Obstrutiva Crônica/terapia , Cuidados Paliativos/métodos , Humanos
6.
J Pain Symptom Manage ; 65(3): e181-e187, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36423798

RESUMO

BACKGROUND: Providing palliative care to patients with chronic obstructive pulmonary disease (COPD) is a priority. Spirometry demonstrating airflow limitation is a diagnostic test for COPD and a common inclusion criterion for palliative care research. However, requiring spirometry with airflow limitation may exclude appropriate patients unable to complete spirometry, or patients with preserved-ratio impaired spirometry and symptoms or imaging consistent with COPD. MEASURES: To determine differences in quality of life (QOL) and symptoms between patients with COPD identified based on International Classification of Diseases (ICD) codes and spirometry with airflow limitation compared to ICD codes only. INTERVENTION: Patients with COPD enrolled in a palliative care trial were included. Patients were at high risk of hospitalization and death and reported poor QOL. Baseline measures of QOL (Functional Assessment of Cancer Therapy-General (FACT-G), the Clinical COPD Questionnaire, and Quality of Life at the End of Life), and symptoms (Patient Health Questionnaire-8, Generalized Anxiety Disorder-7, fatigue, Insomnia Severity Index) were compared. OUTCOMES: Two hundred eight patients with COPD were predominantly male, White, and average age was 68.4. Between patients with ICD codes and spirometry with airflow limitation compared to patients with ICD codes only, there were no significant differences in FACT-G (59.0 vs. 55.0, P = 0.33), other measures of QOL, or symptoms between groups. CONCLUSION: These results imply that spirometry may not need to be a requirement for inclusion into palliative care research or clinical care for patients with poor quality of life and at high risk for adverse outcomes.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , Humanos , Masculino , Idoso , Feminino , Cuidados Paliativos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Hospitalização , Espirometria
7.
J Palliat Med ; 23(12): 1606-1612, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32380886

RESUMO

Background: The optimal timing to introduce palliative care (PC) and end-of-life (EOL) conversations into the lives of people with cystic fibrosis (CF) has not been established. Objective: Compare EOL care practices for people with CF who died without a lung transplant (LT), are living without an LT, and those who received an LT. Design: Retrospective chart review. Setting/Subjects: People with CF who received care from 2012 to 2017 at the University of Texas Southwestern Medical Center. Measurements: Primary outcomes were (1) EOL discussion with a pulmonologist, (2) time of EOL discussion before death or LT, (3) evaluation by PC, and (4) documentation of advanced directive or medical power of attorney. Results: Twenty-three patients died without LT, 40 patients received an LT, and 222 were living without an LT. Among LT recipients, 10% had EOL conversations compared with 74% of deceased patients and 5% of living patients without LT (p = 0.001). Among deceased patients, 39% had EOL conversations more than six months before death, while 5% of transplanted patients had EOL conversation more than six months before LT (p < 0.001). Deceased patients were more likely to have seen PC (57%) than either patients who received LT (2%) or those living without LT (3%, p = 0.0001). Conclusions: Patients who died without LT were more likely to have seen PC and had an EOL conversation than patients who received LT or who are living without LT. Further research should explore the optimal timing to discuss EOL care and the best timing to involve PC.


Assuntos
Fibrose Cística , Cuidados Paliativos na Terminalidade da Vida , Transplante de Pulmão , Assistência Terminal , Fibrose Cística/cirurgia , Humanos , Estudos Retrospectivos
8.
BMJ Case Rep ; 20182018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30061130

RESUMO

We describe a case of an adult with dermatomyositis (DM) who presents with a rash, high fevers, tachycardia and hypotension, initially concerning for an infectious aetiology or a DM flare. She was found to have cytomegalovirus viraemia which improved after starting valganciclovir. After extensive workup and lack of improvement with broad-spectrum antimicrobial therapy, intravenous immunoglobulin and steroids, the patient was diagnosed with macrophage activation syndrome after bone marrow biopsy and levels of soluble CD25 (soluble interleukin (IL)-2 receptor) and IL2 were obtained. Unfortunately, despite therapy with dexamethasone, anakinra and etoposide, the patient decompensated and the patient's family opted for comfort care. The patient subsequently expired in the intensive care unit.


Assuntos
Infecções por Citomegalovirus/fisiopatologia , Dermatomiosite/fisiopatologia , Ganciclovir/análogos & derivados , Imunoglobulinas Intravenosas/uso terapêutico , Síndrome de Ativação Macrofágica/diagnóstico , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/tratamento farmacológico , Dermatomiosite/sangue , Dermatomiosite/tratamento farmacológico , Dermatomiosite/virologia , Evolução Fatal , Feminino , Ganciclovir/uso terapêutico , Humanos , Síndrome de Ativação Macrofágica/fisiopatologia , Síndrome de Ativação Macrofágica/virologia , Pessoa de Meia-Idade , Valganciclovir , Viremia
9.
Cancers (Basel) ; 10(4)2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29617282

RESUMO

Gene rearrangements resulting in the aberrant activity of tyrosine kinases have been identified as drivers of oncogenesis in a variety of cancers. The tropomyosin receptor kinase (TRK) family of tyrosine receptor kinases is emerging as an important target for cancer therapeutics. The TRK family contains three members, TRKA, TRKB, and TRKC, and these proteins are encoded by the genes NTRK1, NTRK2, and NTRK3, respectively. To activate TRK receptors, neurotrophins bind to the extracellular region stimulating dimerization, phosphorylation, and activation of downstream signaling pathways. Major known downstream pathways include RAS/MAPK/ERK, PLCγ, and PI3K/Akt. While being rare in most cancers, TRK fusions with other proteins have been well-established as oncogenic events in specific malignancies, including glioblastoma, papillary thyroid carcinoma, and secretory breast carcinomas. TRK protein amplification as well as alternative splicing events have also been described as contributors to cancer pathogenesis. For patients harboring alterations in TRK expression or activity, TRK inhibition emerges as an important therapeutic target. To date, multiple trials testing TRK-inhibiting compounds in various cancers are underway. In this review, we will summarize the current therapeutic trials for neoplasms involving NTKR gene alterations, as well as the promises and setbacks that are associated with targeting gene fusions.

10.
Oncogene ; 37(19): 2502-2514, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29449694

RESUMO

Signal transducer and activator of transcription 3 (STAT3), glioma oncogene homolog 1 (GLI1), and truncated GLI1 (tGLI1) are oncogenic transcription factors playing important roles in breast cancer. tGLI1 is a gain-of-function GLI1 isoform. Whether STAT3 physically and/or functionally interacts with GLI1/tGLI1 has not been explored. To address this knowledge gap, we analyzed 47 node-positive breast cancer specimens using immunohistochemical staining and found that phosphorylated-STAT3 (Y705), GLI1, and tGLI1 are co-overexpressed in the majority of triple-negative breast carcinomas (64%) and HER2-enriched (68%) breast carcinomas, and in lymph node metastases (65%). Using gene set enrichment analysis, we analyzed 710 breast tumors and found that STAT3 activation and GLI1/tGLI1 activation signatures are co-enriched in triple-negative subtypes of breast cancers and HER2-enriched subtypes of breast cancers, but not in luminal subtypes of breast cancers. Patients with high levels of STAT3 and GLI1/tGLI1 co-activation in their breast tumors had worse metastasis-free survival compared to those with low levels. Since these proteins co-overexpress in breast tumors, we examined whether they form complexes and observed that STAT3 interacted with both GLI1 and tGLI1. We further found that the STAT3-GLI1 and STAT3-tGLI1 complexes bind to both consensus GLI1-binding and STAT3-binding sites using chromatin immunoprecipitation (ChIP) assay, and that the co-overexpression markedly activated a promoter controlled by GLI1-binding sites. To identify genes that can be directly co-activated by STAT3 and GLI1/tGLI1, we analyzed three ChIP-seq datasets and identified 34 potential target genes. Following validations using reverse transcription polymerase chain reaction and survival analysis, we identified three genes as novel transcriptional targets of STAT3 and GLI1/tGLI1, R-Ras2, Cep70, and UPF3A. Finally, we observed that co-overexpression of STAT3 with GLI1/tGLI1 promoted the ability of breast cancer cells to form mammospheres and that STAT3 only cooperates with tGLI1 in immortalized mammary epithelial cells. In summary, our study identified novel physical and functional cooperation between two families of oncogenic transcription factors, and the interaction contributes to aggressiveness of breast cancer cells and poor prognosis of triple-negative breast cancers and HER2-enriched breast cancers.


Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundário , Receptor ErbB-2/metabolismo , Fator de Transcrição STAT3/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Proteína GLI1 em Dedos de Zinco/metabolismo , Animais , Neoplasias Encefálicas/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Transplante de Neoplasias , Fosforilação , Prognóstico , Proteínas de Ligação a RNA/genética , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Análise de Sobrevida , Neoplasias de Mama Triplo Negativas/genética , Regulação para Cima
11.
Mol Pharm ; 14(4): 1107-1119, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-28264565

RESUMO

Many atypical antipsychotic drugs currently prescribed for the treatment of schizophrenia have limited brain penetration due to the efflux activity of ATP-binding cassette (ABC) transporters at the blood-brain barrier (BBB), including P-glycoprotein (P-gp) and ABCG2. Herein, we describe the design and synthesis of the first class of homodimeric prodrug dual inhibitors of P-gp and ABCG2. These inhibitors are based on the structure of the atypical antipsychotic drug paliperidone (Pal), a transport substrate for both transporters. We synthesized and characterized a small library of homodimeric bivalent Pal inhibitors that contain a variety of tethers joining the two monomers via ester linkages. The majority of our compounds were low micromolar to sub-micromolar inhibitors of both P-gp and ABCG2 in cells overexpressing these transporters and in immortalized human hCMEC/D3 cells that are derived from the BBB. Our most potent dual inhibitor also contained an internal disulfide bond in the tether (Pal-8SS) that allowed for rapid reversion to monomer in the presence of reducing agents or plasma esterases. To increase stability against these esterases, we further engineered Pal-8SS to contain two hindering methyl groups alpha to the carbonyl of the ester moiety within the tether. The resulting dimer, Pal-8SSMe, was also a potent dual inhibitor that remained susceptible to reducing conditions but was more resistant to breakdown in human plasma. Importantly, Pal-8SSMe both accumulated and subsequently reverted to the therapeutic Pal monomer in the reducing environment of BBB cells. Thus, these molecules serve two purposes, acting as both inhibitors of P-gp and ABCG2 at the BBB and as prodrugs, effectively delivering therapies to the brain that would otherwise be precluded.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Antipsicóticos/farmacologia , Barreira Hematoencefálica/metabolismo , Proteínas de Neoplasias/metabolismo , Palmitato de Paliperidona/farmacologia , Pró-Fármacos/farmacologia , Transporte Biológico/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular Tumoral , Humanos , Células MCF-7
12.
Psychol Addict Behav ; 29(2): 329-37, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26076097

RESUMO

Understanding behavioral resilience among at-risk adolescents may guide public policy decisions and future programs. We examined factors predicting behavioral resilience following intrauterine substance exposure in a prospective longitudinal birth-cohort study of 136 early adolescents (ages 12.4-15.9 years) at risk for poor behavioral outcomes. We defined behavioral resilience as a composite measure of lack of early substance use initiation (before age 14), lack of risky sexual behavior, or lack of delinquency. Intrauterine substance exposures included in this analysis were cocaine, tobacco, alcohol, and marijuana. We recruited participants from Boston Medical Center as mother-infant dyads between 1990 and 1993. The majority of the sample was African American/Caribbean (88%) and 49% female. In bivariate analyses, none and lower intrauterine cocaine exposure level predicted resilience compared with higher cocaine exposure, but this effect was not found in an adjusted model. Instead, strict caregiver supervision (adjusted odds ratio [AOR] = 6.02, 95% confidence interval (CI) [1.90, 19.00], p = .002), lower violence exposure (AOR = 4.07, 95% CI [1.77, 9.38], p < .001), and absence of intrauterine tobacco exposure (AOR = 3.71, 95% CI [1.28, 10.74], p = .02) predicted behavioral resilience. In conclusion, caregiver supervision in early adolescence, lower violence exposure in childhood, and lack of intrauterine tobacco exposure predicted behavioral resilience among a cohort of early adolescents with significant social and environmental risk. Future interventions should work to enhance parental supervision as a way to mitigate the effects of adversity on high-risk groups of adolescents. (PsycINFO Database Record


Assuntos
Comportamento do Adolescente/fisiologia , Cannabis/efeitos adversos , Cocaína/efeitos adversos , Etanol/efeitos adversos , Nicotiana/efeitos adversos , Poder Familiar/psicologia , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Resiliência Psicológica , Violência/psicologia , Adolescente , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Gravidez , Resiliência Psicológica/efeitos dos fármacos
13.
Mol Endocrinol ; 28(4): 458-76, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24506535

RESUMO

We investigated the role of Cav1.2 in pancreatic ß-cell function by expressing a Cav1.2 II-III loop/green fluorescent protein fusion in INS-1 cells (Cav1.2/II-III cells) to disrupt channel-protein interactions. Neither block of KATP channels nor stimulation of membrane depolarization by tolbutamide was different in INS-1 cells compared with Cav1.2/II-III cells, but whole-cell Cav current density was significantly increased in Cav1.2/II-III cells. Tolbutamide (200 µM) stimulated insulin secretion and Ca(2+) transients in INS-1 cells, and Cav1.2/II-III cells were completely blocked by nicardipine (2 µM), but thapsigargin (1 µM) blocked tolbutamide-stimulated secretion and Ca(2+) transients only in INS-1 cells. Tolbutamide-stimulated endoplasmic reticulum [Ca(2+)] decrease was reduced in Cav1.2/II-III cells compared with INS-1 cells. However, Ca(2+) transients in both INS-1 cells and Cav1.2/II-III cells were significantly potentiated by 8-pCPT-2'-O-Me-cAMP (5 µM), FPL-64176 (0.5 µM), or replacement of extracellular Ca(2+) with Sr(2+). Glucose (10 mM) + glucagon-like peptide-1 (10 nM) stimulated discrete spikes in [Ca(2+)]i in the presence of verapamil at a higher frequency in INS-1 cells than in Cav1.2/II-II cells. Glucose (18 mM) stimulated more frequent action potentials in Cav1.2/II-III cells and primary rat ß-cells expressing the Cav1.2/II-II loop than in control cells. Further, apamin (1 µM) increased glucose-stimulated action potential frequency in INS-1 cells, but not Cav1.2/II-III cells, suggesting that SK channels were not activated under these conditions in Cav1.2/II-III loop-expressing cells. We propose the II-III loop of Cav1.2 as a key molecular determinant that couples the channel to Ca(2+)-induced Ca(2+) release and activation of SK channels in pancreatic ß-cells.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Cálcio/metabolismo , Cálcio/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Canais de Cálcio Tipo L/química , Fracionamento Celular , Centrifugação com Gradiente de Concentração , AMP Cíclico/análogos & derivados , Endocitose/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Fator de Iniciação 3 em Eucariotos/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glucose/farmacologia , Imunoprecipitação , Insulina/metabolismo , Secreção de Insulina , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Estrutura Secundária de Proteína , Ratos , Ratos Wistar , Tolbutamida/farmacologia , Verapamil/farmacologia , Proteínas Ativadoras de ras GTPase/metabolismo
14.
Mol Pharmacol ; 83(1): 191-205, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23071106

RESUMO

Tolbutamide and gliclazide block the K(ATP) channel K(ir)6.2/Sur1, causing membrane depolarization and stimulating insulin secretion in pancreatic beta cells. We examined the ability of the EPAC-selective cAMP analog 8-pCPT-2'-O-Me-cAMP-AM to potentiate the action of these drugs and the mechanism that might account for it. Insulin secretion stimulated by both 200 µM tolbutamide and 20 µM gliclazide, concentrations that had equivalent effects on membrane potential, was inhibited by thapsigargin (1 µM) or the L-type Ca(2+) channel blocker nicardipine (2 µM) and was potentiated by 8-pCPT-2'-O-Me-cAMP-AM at concentrations ≥2 µM in INS-1 cells. Ca(2+) transients stimulated by either tolbutamide or gliclazide were inhibited by thapsigargin or nicardipine and were significantly potentiated by 8-pCPT-2'-O-Me-cAMP-AM at 5 µM but not 1 µM. Both tolbutamide and gliclazide stimulated phospholipase C activity; however, only gliclazide did so independently of its activity at K(ATP) channels, and this activity was partially inhibited by pertussis toxin. 8-pCPT-2'-O-Me-cAMP-AM alone (5 µM) did not stimulate insulin secretion, but did increase intracellular Ca(2+) concentration significantly, and this activity was inhibited by 25 µM 2-aminoethoxydiphenylborate (2-APB) or the removal of extracellular Ca(2+). 8-pCPT-2'-O-Me-cAMP-AM potentiation of insulin secretion stimulated by tolbutamide was markedly inhibited by 2-APB (25 µM) and enhanced by the PKC inhibitor bisindolylmaleimide I (1 µM). Our data demonstrate that the actions of both tolbutamide and gliclazide are strongly potentiated by 8-pCPT-2'-O-Me-cAMP-AM, that gliclazide can stimulate phospholipase C activity via a partially pertussis toxin-sensitive mechanism, and that 8-pCPT-2'-O-Me-cAMP-AM potentiation of tolbutamide action may involve activation of a 2-APB-sensitive Ca(2+) influx.


Assuntos
Compostos de Boro/farmacologia , AMP Cíclico/análogos & derivados , Gliclazida/farmacologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Hipoglicemiantes/farmacologia , Tolbutamida/farmacologia , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/fisiologia , Linhagem Celular Tumoral , AMP Cíclico/farmacologia , Sinergismo Farmacológico , Ativação Enzimática , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Indóis/farmacologia , Insulina/metabolismo , Secreção de Insulina , Espaço Intracelular/metabolismo , Canais KATP/fisiologia , Maleimidas/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/metabolismo
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