Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34479991

RESUMO

COVID-19 induces a robust, extended inflammatory "cytokine storm" that contributes to an increased morbidity and mortality, particularly in patients with type 2 diabetes (T2D). Macrophages are a key innate immune cell population responsible for the cytokine storm that has been shown, in T2D, to promote excess inflammation in response to infection. Using peripheral monocytes and sera from human patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a murine hepatitis coronavirus (MHV-A59) (an established murine model of SARS), we identified that coronavirus induces an increased Mφ-mediated inflammatory response due to a coronavirus-induced decrease in the histone methyltransferase, SETDB2. This decrease in SETDB2 upon coronavirus infection results in a decrease of the repressive trimethylation of histone 3 lysine 9 (H3K9me3) at NFkB binding sites on inflammatory gene promoters, effectively increasing inflammation. Mφs isolated from mice with a myeloid-specific deletion of SETDB2 displayed increased pathologic inflammation following coronavirus infection. Further, IFNß directly regulates SETDB2 in Mφs via JaK1/STAT3 signaling, as blockade of this pathway altered SETDB2 and the inflammatory response to coronavirus infection. Importantly, we also found that loss of SETDB2 mediates an increased inflammatory response in diabetic Mϕs in response to coronavirus infection. Treatment of coronavirus-infected diabetic Mφs with IFNß reversed the inflammatory cytokine production via up-regulation of SETDB2/H3K9me3 on inflammatory gene promoters. Together, these results describe a potential mechanism for the increased Mφ-mediated cytokine storm in patients with T2D in response to COVID-19 and suggest that therapeutic targeting of the IFNß/SETDB2 axis in T2D patients may decrease pathologic inflammation associated with COVID-19.


Assuntos
Coronavirus/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Mediadores da Inflamação/metabolismo , Inflamação/virologia , Macrófagos/metabolismo , Animais , COVID-19/imunologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Síndrome da Liberação de Citocina , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , SARS-CoV-2/metabolismo , Transdução de Sinais
2.
Eur J Immunol ; 50(12): 1929-1940, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32662520

RESUMO

Chronic macrophage inflammation is a hallmark of type 2 diabetes (T2D) and linked to the development of secondary diabetic complications. T2D is characterized by excess concentrations of saturated fatty acids (SFA) that activate innate immune inflammatory responses, however, mechanism(s) by which SFAs control inflammation is unknown. Using monocyte-macrophages isolated from human blood and murine models, we demonstrate that palmitate (C16:0), the most abundant circulating SFA in T2D, increases expression of the histone demethylase, Jmjd3. Upregulation of Jmjd3 results in removal of the repressive histone methylation (H3K27me3) mark on NFκB-mediated inflammatory gene promoters driving macrophage-mediated inflammation. We identify that the effects of palmitate are fatty acid specific, as laurate (C12:0) does not regulate Jmjd3 and the associated inflammatory profile. Further, palmitate-induced Jmjd3 expression is controlled via TLR4/MyD88-dependent signaling mechanism, where genetic depletion of TLR4 (Tlr4-/- ) or MyD88 (MyD88-/- ) negated the palmitate-induced changes in Jmjd3 and downstream NFκB-induced inflammation. Pharmacological inhibition of Jmjd3 using a small molecule inhibitor (GSK-J4) reduced macrophage inflammation and improved diabetic wound healing. Together, we conclude that palmitate contributes to the chronic Jmjd3-mediated activation of macrophages in diabetic peripheral tissue and a histone demethylase inhibitor-based therapy may represent a novel treatment for nonhealing diabetic wounds.


Assuntos
Histona Desmetilases/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Macrófagos/metabolismo , Palmitatos/metabolismo , Receptor 4 Toll-Like/metabolismo , Cicatrização/fisiologia , Animais , Diabetes Mellitus Tipo 2 , Humanos , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
3.
Clin Genet ; 97(6): 815-826, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31957007

RESUMO

Abdominal aortic aneurysms (AAAs) are focal dilations of the aorta that develop from degenerative changes in the media and adventitia of the vessel. Ruptured AAAs have a mortality of up to 85%, thus it is important to identify patients with AAA at increased risk for rupture who would benefit from increased surveillance and/or surgical repair. Although the exact genetic and epigenetic mechanisms regulating AAA formation are not completely understood, Mendelian cases of AAA, which result from pathologic variants in a single gene, have helped provide a basic understanding of AAA pathophysiology. More recently, genome wide associated studies (GWAS) have identified additional variants, termed single nucleotide polymorphisms, in humans that may be associated with AAAs. While some variants may be associated with AAAs and play causal roles in aneurysm pathogenesis, it should be emphasized that the majority of SNPs do not actually cause disease. In addition to GWAS, other studies have uncovered epigenetic causes of disease that regulate expression of genes known to be important in AAA pathogenesis. This review describes many of these genetic and epigenetic contributors of AAAs, which altogether provide a deeper insight into AAA pathogenesis.


Assuntos
Aneurisma da Aorta Abdominal/genética , Epigênese Genética , Predisposição Genética para Doença , Aneurisma da Aorta Abdominal/patologia , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
4.
Small GTPases ; 11(3): 194-203, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-29099324

RESUMO

Vascular resistance is a major determinant of BP and is controlled, in large part, by RhoA-dependent smooth muscle cell (SMC) contraction within small peripheral arterioles and previous studies from our lab indicate that GRAF3 is a critical regulator of RhoA in vascular SMC. The elevated contractile responses we observed in GRAF3 deficient vessels coupled with the hypertensive phenotype provided a mechanistic link for the hypertensive locus recently identified within the GRAF3 gene. On the basis of our previous findings that the RhoA signaling axis also controls SMC contractile gene expression and that GRAF3 expression was itself controlled by this pathway, we postulated that GRAF3 serves as an important counter-regulator of SMC phenotype. Indeed, our new findings presented herein indicate that GRAF3 expression acts as a pressure-sensitive rheostat to control vessel tone by both reducing calcium sensitivity and restraining expression of the SMC-specific contractile proteins that support this function. Collectively, these studies highlight the potential therapeutic value of GRAF3 in the control of human hypertension.

5.
Am J Physiol Heart Circ Physiol ; 318(2): H413-H424, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31886719

RESUMO

We previously showed that ARHGAP42 is a smooth muscle cell (SMC)-selective, RhoA-specific GTPase activating protein that regulates blood pressure and that a minor allele single nucleotide variation within a DNAse hypersensitive regulatory element in intron1 (Int1DHS) increased ARHGAP42 expression by promoting serum response factor binding. The goal of the current study was to identify additional transcriptional and posttranscriptional mechanisms that control ARHGAP42 expression. Using deletion/mutation, gel shift, and chromatin immunoprecipitation experiments, we showed that recombination signal binding protein for immunoglobulin κ-J region (RBPJ) and TEA domain family member 1 (TEAD1) binding to a conserved core region was required for full IntDHS transcriptional activity. Importantly, overexpression of the notch intracellular domain (NICD) or plating SMCs on recombinant jagged-1 increased IntDHS activity and endogenous ARHGAP42 expression while siRNA-mediated knockdown of TEAD1 inhibited ARHGAP42 mRNA levels. Re-chromatin immunoprecipitation experiments indicated that RBPJ and TEAD1 were bound to the Int1DHS enhancer at the same time, and coimmunoprecipitation assays indicated that these factors interacted physically. Our results also suggest TEAD1 and RBPJ bound cooperatively to the Int1DHS and that the presence of TEAD1 promoted the recruitment of NICD by RBPJ. Finally, we showed that ARHGAP42 expression was inhibited by micro-RNA 505 (miR505) which interacted with the ARHGAP42 3'-untranslated region (UTR) to facilitate its degradation and by AK124326, a long noncoding RNA that overlaps with the ARHGAP42 transcription start site on the opposite DNA strand. Since siRNA-mediated depletion of AK124326 was associated with increased H3K9 acetylation and RNA Pol-II binding at the ARHGAP42 gene, it is likely that AK124326 inhibits ARHGAP42 transcription.NEW & NOTEWORTHY First, RBPJ and TEAD1 converge at an intronic enhancer to regulate ARHGAP42 expression in SMCs. Second, TEAD1 and RBPJ interact physically and bind cooperatively to the ARHGAP42 enhancer. Third, miR505 interacts with the ARHGAP42 3'-UTR to facilitate its degradation. Finally, LncRNA, AK124326, inhibits ARHGAP42 transcription.


Assuntos
Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Proteínas Ativadoras de GTPase/genética , Regulação da Expressão Gênica/genética , Miócitos de Músculo Liso/metabolismo , Processamento de Proteína Pós-Traducional/genética , Regiões 3' não Traduzidas/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas Ativadoras de GTPase/biossíntese , Deleção de Genes , Técnicas de Silenciamento de Genes , Humanos , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , MicroRNAs/genética , Mutação , Proteínas Nucleares/genética , RNA Longo não Codificante/genética , RNA Interferente Pequeno , Fatores de Transcrição/genética
6.
Turk J Anaesthesiol Reanim ; 47(1): 35-40, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31276109

RESUMO

Objective: Colloid preloading diminishes post-spinal hypotension. However, whether colloid preloading is superior to crystalloid co-loading is uncertain. In this retrospective study, we compared the effects of a colloid preload versus a crystalloid co-load on vasopressor requirements and maternal haemodynamics among women undergoing elective caesarean delivery (CD) with spinal anaesthesia. Methods: We extracted data from the medical records of 160 healthy women who underwent elective CD with spinal anaesthesia at an academic obstetric centre before and after an institutional fluid-loading protocol change. Patients received a 500 mL 6% hydroxyethyl starch preload or a 1000 mL crystalloid co-load. The primary outcome was the total phenylephrine dose administered from spinal block placement to delivery. Results: Our cohort comprised 79 women in the colloid group and 77 women in the crystalloid group. The mean phenylephrine use was significantly lower in the colloid group than in the crystalloid group (489±403 µg vs. 647±464 µg, respectively, p=0.02). The maximal drop in systolic blood pressure was greater in the colloid group than in the crystalloid group (36±20 mmHg vs. 29±16 mmHg, respectively, p=0.02). There were no clinically significant differences between the groups in heart rate, blood loss, temperature and Apgar scores. Conclusion: Vasopressor use was lower in colloid preloading than in crystalloid co-loading. However, differences in all outcome measures were minimal and likely clinically insignificant, suggesting that both fluid-loading techniques are appropriate to use for the prevention of spinal hypotension in women undergoing CD.

7.
Eur J Med Genet ; 62(4): 282-285, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30118858

RESUMO

The authors report for the first time a novel mutation in the FLNC gene associated with cardiac arrhythmias in two half-siblings. The FLNC gene on chromosome 7q32 encodes filamin C, which stabilizes the actin network within the cardiomyocyte. The proband is an 8-year-old asymptomatic patient with frequent premature ventricular contractions noted on serial monitoring. Interestingly, the proband and his half-brother harbored a heterozygous 13 base pair deletion that resulted in a frameshift mutation and introduction of a premature stop codon. Notably, the proband also had a very tragic family history of sudden death in young individuals involving three generations and five family members. Because of their concerning family history and arrhythmias, both siblings underwent off-label implantable cardiac device placement for primary prevention of sudden cardiac death. Whether or not the FLNC mutation is associated with sudden cardiac death requires additional investigation and is beyond the scope of this manuscript. While previous studies have identified several mutations in the FLNC gene associated with dilated and hypertrophic cardiomyopathies, the goal of this study was to report a novel mutation in the FLNC gene that is associated with cardiac arrhythmias. The current study indicates that this mutation may help identify patients at risk for cardiac arrhythmias who would benefit from further cardiac evaluation.


Assuntos
Arritmias Cardíacas/genética , Filaminas/genética , Mutação da Fase de Leitura , Arritmias Cardíacas/patologia , Criança , Códon de Terminação , Morte Súbita Cardíaca , Humanos , Masculino , Linhagem
8.
Pharmacol Ther ; 193: 121-134, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30189292

RESUMO

The prevalence of high blood pressure (also known as hypertension) has steadily increased over the last few decades. Known as a silent killer, hypertension increases the risk for cardiovascular disease and can lead to stroke, heart attack, kidney failure and associated sequela. While numerous hypertensive therapies are currently available, it is estimated that only half of medicated patients exhibit blood pressure control. This signifies the need for a better understanding of the underlying cause of disease and for more effective therapies. While blood pressure homeostasis is very complex and involves the integrated control of multiple body systems, smooth muscle contractility and arterial resistance are important contributors. Strong evidence from pre-clinical animal models and genome-wide association studies indicate that smooth muscle contraction and BP homeostasis are governed by the small GTPase RhoA and its downstream target, Rho kinase. In this review, we summarize the signaling pathways and regulators that impart tight spatial-temporal control of RhoA activity in smooth muscle cells and discuss current therapeutic strategies to target these RhoA pathway components. We also discuss known allelic variations in the RhoA pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations.


Assuntos
Pressão Sanguínea , Proteína rhoA de Ligação ao GTP/fisiologia , Animais , Proteínas Ativadoras de GTPase/fisiologia , Humanos , Transdução de Sinais
9.
J Clin Invest ; 127(2): 670-680, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28112683

RESUMO

We recently demonstrated that selective expression of the Rho GTPase-activating protein ARHGAP42 in smooth muscle cells (SMCs) controls blood pressure by inhibiting RhoA-dependent contractility, providing a mechanism for the blood pressure-associated locus within the ARHGAP42 gene. The goals of the current study were to identify polymorphisms that affect ARHGAP42 expression and to better assess ARHGAP42's role in the development of hypertension. Using DNase I hypersensitivity methods and ENCODE data, we have identified a regulatory element encompassing the ARHGAP42 SNP rs604723 that exhibits strong SMC-selective, allele-specific activity. Importantly, CRISPR/Cas9-mediated deletion of this element in cultured human SMCs markedly reduced endogenous ARHGAP42 expression. DNA binding and transcription assays demonstrated that the minor T allele variation at rs604723 increased the activity of this fragment by promoting serum response transcription factor binding to a cryptic cis-element. ARHGAP42 expression was increased by cell stretch and sphingosine 1-phosphate in a RhoA-dependent manner, and deletion of ARHGAP42 enhanced the progression of hypertension in mice treated with DOCA-salt. Our analysis of a well-characterized cohort of untreated borderline hypertensive patients suggested that ARHGAP42 genotype has important implications in regard to hypertension risk. Taken together, our data add insight into the genetic mechanisms that control blood pressure and provide a potential target for individualized antihypertensive therapies.


Assuntos
Pressão Sanguínea , Proteínas Ativadoras de GTPase/metabolismo , Regulação da Expressão Gênica , Hipertensão/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Polimorfismo de Nucleotídeo Único , Fator de Resposta Sérica/metabolismo , Animais , Sistemas CRISPR-Cas , Proteínas Ativadoras de GTPase/genética , Humanos , Hipertensão/induzido quimicamente , Hipertensão/genética , Hipertensão/fisiopatologia , Camundongos , Camundongos Transgênicos , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/patologia , Fator de Resposta Sérica/genética , Cloreto de Sódio na Dieta/efeitos adversos , Cloreto de Sódio na Dieta/farmacologia , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo
10.
Am J Physiol Heart Circ Physiol ; 307(3): H379-90, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24906914

RESUMO

We have previously shown that RhoA-mediated actin polymerization stimulates smooth muscle cell (SMC)-specific transcription by regulating the nuclear localization of the myocardin-related transcription factors (MRTFs). On the basis of the recent demonstration that nuclear G-actin regulates MRTF nuclear export and observations from our laboratory and others that the RhoA effector, mDia2, shuttles between the nucleus and cytoplasm, we investigated whether nuclear RhoA signaling plays a role in regulating MRTF activity. We identified sequences that control mDia2 nuclear-cytoplasmic shuttling and used mDia2 variants to demonstrate that the ability of mDia2 to fully stimulate MRTF nuclear accumulation and SMC-specific gene transcription was dependent on its localization to the nucleus. To test whether RhoA signaling promotes nuclear actin polymerization, we established a fluorescence recovery after photobleaching (FRAP)-based assay to measure green fluorescent protein-actin diffusion in the nuclear compartment. Nuclear actin FRAP was delayed in cells expressing nuclear-targeted constitutively active mDia1 and mDia2 variants and in cells treated with the polymerization inducer, jasplakinolide. In contrast, FRAP was enhanced in cells expressing a nuclear-targeted variant of mDia that inhibits both mDia1 and mDia2. Treatment of 10T1/2 cells with sphingosine 1-phosphate induced RhoA activity in the nucleus and forced nuclear localization of RhoA or the Rho-specific guanine nucleotide exchange factor (GEF), leukemia-associated RhoGEF, enhanced the ability of these proteins to stimulate MRTF activity. Taken together, these data support the emerging idea that RhoA-dependent nuclear actin polymerization has important effects on transcription and nuclear structure.


Assuntos
Núcleo Celular/enzimologia , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/enzimologia , Transdução de Sinais , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética , Proteínas rho de Ligação ao GTP/metabolismo , Actinas/genética , Actinas/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Aorta Torácica/enzimologia , Células COS , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Diferenciação Celular , Chlorocebus aethiops , Recuperação de Fluorescência Após Fotodegradação , Forminas , Regulação da Expressão Gênica , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , NADPH Desidrogenase/genética , NADPH Desidrogenase/metabolismo , Interferência de RNA , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo , Fatores de Tempo , Transativadores/genética , Fatores de Transcrição/genética , Transfecção , Proteína rhoA de Ligação ao GTP
11.
J Manipulative Physiol Ther ; 35(3): 235-43, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22341795

RESUMO

OBJECTIVE: Spinal manipulative therapy (SMT) has been reported to successfully treat hypertension (HTN). The purpose of this study was to perform a qualitative literature review on the efficacy of SMT for treating HTN. METHODS: The literature was systematically searched in PubMed, Medline, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature, and Index of Chiropractic Literature. Included articles were rated for bias using the Cochrane Collaboration's tool for assessing risk of bias. Studies reporting differing methodologies, types of SMT, frequency of treatment, and time of follow-up were considered too dissimilar for meta-analysis. RESULTS: Of 208 articles identified, 10 were selected as relevant and were assessed. Risk of bias scores revealed 2 studies with low risk, 3 studies with unclear risk, and 5 studies with high risk. The maximum improvement observed in any SMT group, in low risk of bias studies was -9.7 (95% confidence interval [CI], -21.1 to 1.8) systolic improvement and -9.0 (95% CI, -16.8 to -1.2) diastolic; and in unclear risk of bias studies, it was -17.2 (95% CI, -20.7 to -13.7) systolic and -13.0 (95% CI, -15.4 to -10.6) diastolic. Statistically significant decreases in blood pressure were not observed in clinical trials with low bias when SMT was compared with effleurage massage and a 5-minute wait. The studies with more risk of bias showed a greater treatment effect. CONCLUSION: There is currently a lack of low bias evidence to support the use of SMT as a therapy for the treatment of HTN. Future investigations may clarify if SMT is effective for treating HTN, either by itself or as an adjunctive therapy, and by which physiologic mechanism this occurs.


Assuntos
Hipertensão/diagnóstico , Hipertensão/terapia , Manipulação da Coluna/métodos , Determinação da Pressão Arterial , California , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...