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1.
Parkinsonism Relat Disord ; 124: 107014, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38823169

RESUMO

BACKGROUND: Task-specific dystonia (TSFD) is a disabling movement disorder. Effective treatment options are currently limited. Zolpidem was reported to improve primary focal and generalized dystonia in a proportion of patients. The mechanisms underlying its therapeutic effects have not yet been investigated. METHODS: We conducted a randomized, double-blind, placebo-controlled, crossover trial of single-dose zolpidem in 24 patients with TSFD. Patients were clinically assessed using Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS), Writers' Cramp Rating Scale (WCRS), and Visual Analogue Scale (VAS), before and after receiving placebo and zolpidem. Transcranial magnetic stimulation was conducted on placebo and zolpidem to compare corticospinal excitability - active and resting motor thresholds (AMT and RMT), resting and active input/output curves and intracortical excitability - cortical silent period (CSP), short-interval intracortical inhibition curve (SICI), long-interval intracortical inhibition (LICI) and intracortical facilitation (ICF). Eight patients underwent brain FDG-PET imaging on zolpidem and placebo. RESULTS: Zolpidem treatment improved TSFD. Zolpidem compared to placebo flattened rest and active input/output curves, reduced ICF and was associated with hypometabolism in the right cerebellum and hypermetabolism in the left inferior parietal lobule and left cingulum. Correlations were found between changes in dystonia severity on WCRS and changes in active input/output curve and in brain metabolism, respectively. Patients with lower RMT, and higher rest and active input/output curves exhibited better response to zolpidem compared to placebo. CONCLUSIONS: Zolpidem improved TSFD by reducing corticomotor output and influencing crucial nodes in higher-order sensory and motor networks.

2.
Commun Biol ; 6(1): 538, 2023 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-37202533

RESUMO

During cancer development, tumor cells acquire changes that enable them to invade surrounding tissues and seed metastasis at distant sites. These changes contribute to the aggressiveness of metastatic cancer and interfere with success of therapy. Our comprehensive analysis of "matched" pairs of HNSCC lines derived from primary tumors and corresponding metastatic sites identified several components of Notch3 signaling that are differentially expressed and/or altered in metastatic lines and confer a dependency on this pathway. These components were also shown to be differentially expressed between early and late stages of tumors in a TMA constructed from over 200 HNSCC patients. Finally, we show that suppression of Notch3 improves survival in mice in both subcutaneous and orthotopic models of metastatic HNSCC. Novel treatments targeting components of this pathway may prove effective in targeting metastatic HNSCC cells alone or in combination with conventional therapies.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Animais , Camundongos , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Humanos
3.
Cancer Res Commun ; 2(5): 293-306, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-36875717

RESUMO

Drug repurposing is an attractive option for oncology drug development. Itraconazole is an antifungal ergosterol synthesis inhibitor that has pleiotropic actions including cholesterol antagonism, inhibition of Hedgehog and mTOR pathways. We tested a panel of 28 epithelial ovarian cancer (EOC) cell lines with itraconazole to define its spectrum of activity. To identify synthetic lethality in combination with itraconazole, a whole-genome drop-out genome-scale clustered regularly interspaced short palindromic repeats sensitivity screen in two cell lines (TOV1946 and OVCAR5) was performed. On this basis, we conducted a phase I dose-escalation study assessing the combination of itraconazole and hydroxychloroquine in patients with platinum refractory EOC (NCT03081702). We identified a wide spectrum of sensitivity to itraconazole across the EOC cell lines. Pathway analysis showed significant involvement of lysosomal compartments, the trans-golgi network and late endosomes/lysosomes; similar pathways are phenocopied by the autophagy inhibitor, chloroquine. We then demonstrated that the combination of itraconazole and chloroquine displayed Bliss defined synergy in EOC cancer cell lines. Furthermore, there was an association of cytotoxic synergy with the ability to induce functional lysosome dysfunction, by chloroquine. Within the clinical trial, 11 patients received at least one cycle of itraconazole and hydroxychloroquine. Treatment was safe and feasible with the recommended phase II dose of 300 and 600 mg twice daily, respectively. No objective responses were detected. Pharmacodynamic measurements on serial biopsies demonstrated limited pharmacodynamic impact. In vitro, itraconazole and chloroquine have synergistic activity and exert a potent antitumor effect by affecting lysosomal function. The drug combination had no clinical antitumor activity in dose escalation. Significance: The combination of the antifungal drug itraconazole with antimalarial drug hydroxychloroquine leads to a cytotoxic lysosomal dysfunction, supporting the rational for further research on lysosomal targeting in ovarian cancer.


Assuntos
Antineoplásicos , Neoplasias Ovarianas , Humanos , Feminino , Itraconazol/farmacologia , Hidroxicloroquina/farmacologia , Antifúngicos/metabolismo , Carcinoma Epitelial do Ovário/tratamento farmacológico , Reposicionamento de Medicamentos , Antineoplásicos/farmacologia , Cloroquina/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Lisossomos , Homeostase
4.
Clin Cancer Res ; 27(8): 2340-2351, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33542074

RESUMO

PURPOSE: Although enzalutamide (ENZ) has been widely used to treat de novo or castration-resistant metastatic prostate cancer, resistance develops and disease progression is ultimately inevitable. There are currently no approved targeted drugs to specifically delay or overcome ENZ resistance. EXPERIMENTAL DESIGN: We selected several ENZ-resistant cell lines that replicated clinical characteristics of the majority of patients with ENZ-resistant disease. A high-throughput pharmacologic screen was utilized to identify compounds with greater cytotoxic effect for ENZ-resistant cell lines, compared with parental ENZ-sensitive cells. We validated the potential hits in vitro and in vivo, and used knockdown and overexpression assays to study the dependencies in ENZ-resistant prostate cancer. RESULTS: ABT199 (BCL-2 inhibitor) and IMD0354 (IKKB inhibitor) were identified as potent and selective inhibitors of cell viability in ENZ-resistant cell lines in vitro and in vivo which were further validated using loss-of-function assays of BCL-2 and IKKB. Notably, we observed that overexpression of BCL-2 and IKKB in ENZ-sensitive cell lines was sufficient for the emergence of ENZ resistance. In addition, we confirmed that BCL-2 or IKKB inhibitors suppressed the development of ENZ resistance in xenografts. However, validation of both BCL-2 and IKKB in matched castration-sensitive/resistant clinical samples showed that, concurrent with the development of ENZ/abiraterone resistance in patients, only the protein levels of IKKB were increased. CONCLUSIONS: Our findings identify BCL-2 and IKKB dependencies in clinically relevant ENZ-resistant prostate cancer cells in vitro and in vivo, but indicate that IKKB upregulation appears to have greater relevance to the progression of human castrate-resistant prostate cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Benzamidas/farmacologia , Quinase I-kappa B/metabolismo , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Neoplasias de Próstata Resistentes à Castração/terapia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzamidas/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Quinase I-kappa B/antagonistas & inibidores , Quinase I-kappa B/genética , Masculino , Nitrilas/uso terapêutico , Feniltioidantoína/uso terapêutico , Próstata/patologia , Próstata/cirurgia , Prostatectomia , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/cirurgia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Papillomavirus Res ; 9: 100198, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32416283

RESUMO

Primary HPV testing and triage of HPV-positive women is an effective cervical cancer screening strategy. Such a multi-visit screening algorithm is also promising for community-based screening in resource-poor communities, provided a robust tracking system is in place. A cervical cancer screening campaign was conducted in a rural community in Ethiopia. All women aged 25-65 years were offered genital self-sampling using the Evalyn Brush®. Samples were HPV-DNA-tested at a central laboratory. Key indicators were captured on tablet computers and linked by a cloud-based information system. HPV-positive women were examined at the local clinic using portable colposcopy, p16/Ki-67 dual stain cytology and biopsy examination. CIN2+ women were referred for LEEP to the referral hospital. Of 749 enumerated age-eligible women 634 (85%, (95% CI 82-88)) consented to screening, 429 samples were adequate for HPV testing, giving a total testing coverage of 57% (95% CI 53-62). The hrHPV prevalence was 14% (95% CI 5-22), 72% (95% CI 60-84) attended the clinic for a triage examination. Home-based HPV-DNA self-sampling and clinic-based triage assisted by cloud-based information technology is feasible in rural Ethiopia. Key components of such strategy are broad community awareness, high competency of community workers, and establishment of an adequate self-sampling and HPV-DNA testing platform.


Assuntos
Computação em Nuvem , Processamento Eletrônico de Dados/estatística & dados numéricos , Infecções por Papillomavirus/diagnóstico , Manejo de Espécimes/métodos , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Idoso , Detecção Precoce de Câncer/métodos , Processamento Eletrônico de Dados/métodos , Etiópia , Feminino , Promoção da Saúde/métodos , Humanos , Pessoa de Meia-Idade , Projetos Piloto , População Rural , Autoteste , Manejo de Espécimes/normas
6.
J Med Virol ; 92(1): 113-118, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31471920

RESUMO

Human papillomavirus (HPV) detection is used for screening of cervical cancer and genotype-specific persistence has shown to be mandatory for dysplasia development. Aim of this study was to evaluate the clinical performance of HPV DNA Array for cervical intraepithelial neoplasia 2+ (CIN2+) lesion detection. HPV DNA Array is a polymerase chain reaction-based assay that targets E1 sequences of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97). The clinical evaluation was performed against the reference assay, BS-GP5+/6+ multiplex genotyping (MPG)-Luminex, with 600 cervical smear samples of a referral population. HPV DNA Array detected CIN2+ lesions with a sensitivity of 90.2%, identical to that of MPG-Luminex. Detection of CIN3+ lesions was with a sensitivity of 90.3%, as compared with 88.7% of MPG-Luminex. It demonstrated very good agreement for HPV detection, irrespective of type, of 91.5% (κ = 0.832). HPV DNA Array is a simple and robust assay, with a short protocol of 4 hours hands-on time and automated readout by ELISpot AiDot software. It permits testing of up to 96 samples in one run and may be considered for use in organized screening programs and low resource settings.


Assuntos
Alphapapillomavirus/genética , Colo do Útero/virologia , Técnicas de Genotipagem/normas , Análise de Sequência com Séries de Oligonucleotídeos/normas , Papillomaviridae/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Colposcopia , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/normas , Feminino , Genótipo , Humanos , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia
7.
Intervirology ; 62(3-4): 124-133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487743

RESUMO

BACKGROUND: Cervical cancer is caused by a persistent infection of human papillomavirus (HPV). Therefore, tests which detect the carcinogenic virus can be used for cervical cancer screening. OBJECTIVE: This is the first evaluation of the HPV DNA Array (AID Diagnostika, Strassberg, Germany), an E1-based genotyping polymerase chain reaction (PCR) test for identification of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97). METHODS: Analytical performance of the assay was assessed with cervical cancer cell lines with known HPV status, and preselected clinical cervical scrapings genotyped by multiplexed genotyping (MPG) with a Luminex readout (validated in-house assay). Intra- and inter-laboratory reproducibility experiments were performed to ensure the reliability of the assay. RESULTS: HPV DNA Array identified the intrinsic HPV genotype in all cervical cancer cell lines and demonstrated a high sensitivity for HPV16 probe (1 cell per PCR reaction), as well as HPV18 and 45 probes (100 cells per PCR reaction). When compared with MPG, HPV DNA Array showed a good agreement of 92.2% for HPV detection irrespective of type (κ = 0.601), and demonstrated high agreement for HPV16 (80.7%, κ = 0.836) and HPV18 (86.7%, κ = 0.925). Furthermore, high intra-/inter-laboratory reproducibility was observed (90.9-100%). CONCLUSION: HPV DNA Array showed high sensitivity for correct HPV genotype detection in experimental and clinical samples with a good correlation to the reference test. Since HPV DNA Array is based on a simple multiplexed PCR followed by reverse hybridization in a 96-well format and automated visual readout by AID ELISpot reader, it is capable of high throughput in a time-effective manner. HPV DNA Array could be considered for extended HPV genotyping of cervical smears.


Assuntos
Genótipo , Técnicas de Genotipagem/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteínas Oncogênicas Virais/genética , Papillomaviridae/classificação , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Linhagem Celular Tumoral , Humanos , Papillomaviridae/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
Virol J ; 16(1): 92, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337408

RESUMO

BACKGROUND: HPV DNA Array is an E1-targeting PCR genotyping test, with capability of distinguishing 18 high-risk (16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 82) and 11 low-risk HPV types (6, 11, 40, 42, 44, 54, 67, 69, 70, 85, 97). HPV DNA Array uses multiplex PCR for E1-gene sequence amplification. The amplicons are detected and genotyped by reverse hybridization to immobilized DNA probes spotted as triplets in single 96 well-plate wells and read by AID ELISPOT reader. METHODS: Aim of the study was to evaluate the clinical performance of the assay against internationally accepted and FDA approved Cobas 4800 HPV test (Roche Diagnostics). Study population comprised of 500 cervical samples. RESULTS: HPV DNA Array demonstrated a very high sensitivity of 100% for CIN2+ and 100% for CIN3+ detection, same as Cobas 4800. HPV DNA Array showed greater sensitivity for CIN2+ detection than cytology (100% vs. 13.6%). The agreement to Cobas 4800 for HPV detection, irrespective of type, was 81.4% with κ = 0.613. The agreement for HPV 16 was 92.8% (κ = 0.929), and for HPV 18 54.2% (κ = 0.681). CONCLUSION: HPV DNA Array demonstrated good clinical performance for detection of high-grade lesions, and may be considered for usage in a screening setting.


Assuntos
DNA Viral/genética , Técnicas de Genotipagem/métodos , Papillomaviridae/genética , Infecções por Papillomavirus/diagnóstico , Adulto , Idoso , Colo do Útero/patologia , Colo do Útero/virologia , Técnicas Citológicas , Detecção Precoce de Câncer , Feminino , Genótipo , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Humanos , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Infecções por Papillomavirus/virologia , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Adulto Jovem , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia
9.
PLoS One ; 14(6): e0218762, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31246997

RESUMO

INTRODUCTION: This population-based study aimed to fill the knowledge gap on Human Papillomavirus (HPV) prevalence and associated sociodemographic risk factors of the general population in the North Tongu District, Ghana. These results are needed to guide cervical cancer prevention efforts, as the leading type of female cancers. METHODS: A cross-sectional study including 2002 women in the North Tongu District, Ghana investigated HPV prevalence and associated sociodemographic risk factors. Women were recruited by geographical distribution through the local community-based health system and samples collected using a self-sampling device. For HPV genotyping BSGP5+/6+-PCR with Luminex-MPG readout was used. Multivariate logistic regression analyzed sociodemographic risk factors for HPV positivity. RESULTS: Of 2002 self-collected samples, 1943 were eligible, contained sufficient DNA and provided valid HPV genotyping results. Prevalence of single high risk HPV types was 32.3% and of multiple high risk types 9.7%. The five most common detected HPV types were HPV16 (7.4%; 95%CI: 6.3-8.7), HPV52 (7.2%; 95%CI: 6.1-8.5), HPV35 (4.8%; 95%CI: 3.9-5.8), HPV59 (4.7%; 95%CI: 3.8-5.8), HPV56 (3.9%; 95%CI: 3.1-4.8). Highest prevalence was observed among women aged 18-24 years, while age 25-54 years was inversely associated with high risk HPV positivity in multivariate analysis. Sociodemographic risk factors identified were i) having any sexual partner, ii) more partners increased the odds for high risk HPV positivity, iii) independently from this marital status, in particular not being married. DISCUSSION & CONCLUSION: Most importantly, the high risk HPV prevalence detected from this study is higher than estimates reported for Western Africa. This needs be considered, when deciding on the cervical cancer screening algorithms introduced on a wider scale. Follow-up and triage, depending on the methods chosen, can easily overburden the health system. Self-sampling worked well and provided adequate samples for HPV-based screening. Women with increasing number of sexual partners and not being married were found to have higher odds of being high risk HPV positive, therefore could be a higher prioritized screening target group.


Assuntos
Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Genótipo , Gana/epidemiologia , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Papillomaviridae/classificação , Papillomaviridae/genética , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Adulto Jovem
10.
Support Care Cancer ; 25(2): 549-558, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27747478

RESUMO

PURPOSE: The capture of adequate treatment outcomes and quality of life (QOL) of advanced breast cancer patients in clinical routine represents a great challenge. Patient-reported outcomes (PROs) are data elements directly reported by patients about experiences with care, including symptoms, functional status, or quality of life. There is growing interest in the medical community for the evaluation and implementation of PROs of adverse events (PRO-AEs). Recent interest in PROs in health care has evolved in the context of patient centeredness. Our primary objective was to identify trials that had implemented PRO-AEs in the breast cancer treatment setting, thereby demonstrating its feasibility. We aimed to identify published studies that used patient reports to assess AEs during and after breast cancer treatment, to identify clinician underreported and modifiable AEs that are important to patients, and to analyze the feasibility and usefulness of PRO instrument implementation in everyday oncological practice with special attention given to electronic-based PRO instruments. METHODS: We conducted a systematic search of PubMed for studies that used PRO instruments to assess AEs of breast cancer treatment in the metastatic and adjuvant settings. Two authors independently reviewed the search results and decided which studies fully met the predefined inclusion criteria. RESULTS: The search yielded 606 publications. The two reviewers found that 9 studies met the inclusion criteria. Three AEs were identified as important to patients but inadequately reported by health care providers, namely hot flushes, vaginal dryness, and weight gain. CONCLUSIONS: PROs and PRO-AEs are the consequence of contemporary concepts of patient-centered medicine and the growing feasibility, utility, and implications of collecting data using modern technology. Furthermore, the willingness of patients to utilize innovative applications for their own health has been increasing in parallel to the enhanced impact of the World Wide Web. Especially, the coverage of the metastatic situation promises numerous findings on the structure and quality of health care, enabling implementation of individually tailored interventions. Remote electronic self-reporting (i.e., home reporting) is feasible and is associated with high compliance levels.


Assuntos
Neoplasias da Mama/complicações , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida/psicologia , Feminino , Humanos , Metástase Neoplásica , Autorrelato , Resultado do Tratamento
11.
Vascul Pharmacol ; 44(3): 131-42, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16427812

RESUMO

Long-lasting Ca(2+) (Ca(L)) channels of the Ca(v)1.2 gene family are heteromultimeric structures that are minimally composed of a pore-forming alpha(1C) subunit and regulatory beta and alpha(2)delta subunits in vascular smooth muscle cells. The Ca(L) channels are the primary pathways for voltage-gated Ca(2+) influx that trigger excitation-contraction coupling in small resistance vessels. Notably, vascular smooth muscle cells of hypertensive rats show an increased expression of Ca(L) channel alpha(1C) subunits, which is associated with elevated Ca(2+) influx and the development of abnormal arterial tone. Indeed, blood pressure per se appears to promote Ca(L) channel expression in small arteries, and even short-term rises in pressure may alter channel expression. Membrane depolarization has been shown to be one stimulus associated with elevated blood pressure that promotes Ca(L) channel expression at the plasma membrane. Future studies to define the molecular processes that regulate Ca(L) channel expression in vascular smooth muscle cells will provide a rational basis for designing antihypertensive therapies to normalize Ca(L) channel expression and the development of anomalous vascular tone in hypertensive pathologies.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Hipertensão/metabolismo , Músculo Liso Vascular/fisiologia , Animais , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Canais de Cálcio Tipo L/química , Canais de Cálcio Tipo L/genética , Regulação da Expressão Gênica , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Ativação do Canal Iônico , Potenciais da Membrana , Músculo Liso Vascular/efeitos dos fármacos , Conformação Proteica
12.
Circ Res ; 94(10): e97-104, 2004 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-15131006

RESUMO

Long-lasting Ca2+ (Ca(L)) channels of the Ca(v)1.2 gene family contribute to the pathogenesis of abnormal arterial tone in hypertension. The physiological stimulus that enhances Ca(L) channel current in the vascular smooth muscle cells (VSMCs) remains unknown. The present study investigated if high blood pressure triggers an upregulation of vascular Ca(L) channel protein. Rat aortae were banded between the origins of the left renal (LR) and right renal (RR) arteries to selectively elevate blood pressure in the proximal RR arteries. After 2 days, the immunoreactivity on Western blots corresponding to the pore-forming alpha1C subunit of the Ca(L) channel was increased 3.25-fold in RR compared with LR arteries. This finding persisted at 28 days and was associated with abnormal Ca2+-dependent tone and higher Ca(L) currents in the VSMCs exposed to high pressure. Based on microelectrode studies indicating that RR arteries were depolarized compared with LR arteries, further studies examined if membrane depolarization, an inherent response of VSMCs to high blood pressure, increased alpha1C expression. Isolated rat renal arteries were cultured for 2 days in low K+ (4 mmol/L) or depolarizing high K+ (30 mmol/L) media. Arteries preconditioned in high K+ showed a 5.47-fold increase in alpha1C expression, enhanced Ca(L) channel current, and elevated Ca2+-dependent tone. These findings provide the first direct evidence that high blood pressure upregulates the Ca(L) channel alpha1C subunit in VSMCs in vivo and suggest that membrane depolarization is a potential signal involved in this interaction that may contribute to the development of abnormal vascular tone.


Assuntos
Artérias/fisiologia , Pressão Sanguínea , Canais de Cálcio Tipo L/metabolismo , Animais , Técnicas de Cultura , Hipertensão/etiologia , Potenciais da Membrana , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Regulação para Cima
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