Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
J Org Chem ; 89(8): 5401-5408, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38546539

RESUMO

A synthetically useful approach to functionalized triazoles is described via the reaction of ß-carbonyl phosphonates and azides. 1,4- and 1,5-disubstituted and 1,4,5-trisubstituted triazoles can be regio- and chemoselectively accessed under mild conditions in good to excellent yields (31 examples, up to 99%). A mechanism is proposed that rationalizes the avoidance of the 4-phosphonate byproducts, which is aligned with crystallographic and experimental evidence.

2.
Mol Biol Rep ; 51(1): 562, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644407

RESUMO

BACKGROUND: Obesity is associated with a wide variety of metabolic disorders that impose significant burdens on patients and society. The "browning" phenomenon in white adipose tissue (WAT) has emerged as a promising therapeutic strategy to combat metabolic disturbances. However, though the anti-diabetic drug dapagliflozin (DAPA) is thought to promote "browning," the specific mechanism of this was previously unclear. METHODS: In this study, C57BL/6 J male mice were used to establish an obesity model by high-fat diet feeding, and 3T3-L1 cells were used to induce mature adipocytes and to explore the role and mechanism of DAPA in "browning" through a combination of in vitro and in vivo experiments. RESULTS: The results show that DAPA promotes WAT "browning" and improves metabolic disorders. Furthermore, we discovered that DAPA activated "browning" through the fibroblast growth factor receptors 1-liver kinase B1-adenosine monophosphate-activated protein kinase signaling pathway. CONCLUSION: These findings provide a rational basis for the use of DAPA in treating obesity by promoting the browning of white adipose tissue.


Assuntos
Tecido Adiposo Branco , Compostos Benzidrílicos , Glucosídeos , Proteínas Serina-Treonina Quinases , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Transdução de Sinais , Animais , Masculino , Camundongos , Células 3T3-L1 , Adipócitos/metabolismo , Adipócitos/efeitos dos fármacos , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Compostos Benzidrílicos/farmacologia , Dieta Hiperlipídica , Glucosídeos/farmacologia , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/tratamento farmacológico , Proteínas Serina-Treonina Quinases/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais/efeitos dos fármacos
3.
J Med Internet Res ; 26: e48748, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38190237

RESUMO

BACKGROUND: The prevalence of atrial fibrillation (AF) continues to increase in modern aging society. Patients with AF are at high risk for multiple adverse cardiovascular events, including heart failure, stroke, and mortality. Improved medical care is needed for patients with AF to enhance their quality of life and limit their medical resource utilization. With advances in the internet and technology, telehealth programs are now widely used in medical care. A fourth-generation telehealth program offers synchronous and continuous medical attention in response to physiological parameters measured at home. Although we have previously shown the benefits of this telehealth program for some patients with a high risk of cardiovascular disease, its benefits for patients with AF remains uncertain. OBJECTIVE: This study aims to investigate the benefits of participating in a fourth-generation telehealth program for patients with AF in relation to cardiovascular outcomes. METHODS: This was a retrospective cohort study. We retrospectively searched the medical records database of a tertiary medical center in Northern Taiwan between January 2007 and December 2017. We screened 5062 patients with cardiovascular disease and enrolled 537 patients with AF, of which 279 participated in the telehealth program and 258 did not. Bias was reduced using the inverse probability of treatment weighting adjustment based on the propensity score. Outcomes were collected and analyzed, including all-cause readmission, admission for heart failure, acute coronary syndrome, ischemic stroke, systemic embolism, bleeding events, all-cause mortality, and cardiovascular death within the follow-up period. Total medical expenses and medical costs in different departments were also compared. Subgroup analyses were conducted on ischemic stroke stratified by several subgroup variables. RESULTS: The mean follow-up period was 3.0 (SD 1.7) years for the telehealth group and 3.4 (SD 1.9) years for the control group. After inverse probability of treatment weighting adjustment, the patients in the telehealth program had significantly fewer ischemic strokes (2.0 vs 4.5 events per 100 person-years; subdistribution hazard ratio [SHR] 0.45, 95% CI 0.22-0.92) and cardiovascular deaths (2.5 vs 5.9 events per 100 person-years; SHR 0.43, 95% CI 0.18-0.99) at the follow-up. The telehealth program particularly benefited patients comorbid with vascular disease (SHR 0.11, 95% CI 0.02-0.53 vs SHR 1.16, 95% CI 0.44-3.09; P=.01 for interaction). The total medical expenses during follow-up were similar in the telehealth and control groups. CONCLUSIONS: This study demonstrated the benefits of participating in the fourth-generation telehealth program for patients with AF by significantly reducing their ischemic stroke risk while spending the same amount on medical expenses.


Assuntos
Fibrilação Atrial , Insuficiência Cardíaca , AVC Isquêmico , Telemedicina , Humanos , Fibrilação Atrial/terapia , Estudos Retrospectivos , Qualidade de Vida , Insuficiência Cardíaca/terapia
4.
BMC Pediatr ; 23(1): 169, 2023 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-37046233

RESUMO

BACKGROUND: This study examined the associations of diet quality assessed by Healthy Eating Index 2015 (HEI-2015), Alternative Healthy Eating Index 2010 (AHEI-2010), Mediterranean Diet (MedDiet) and overweight/obesity in children and adolescents. METHODS: This cross-sectional study used data of participants aged 2-19 years from National Health and Nutrition Examination Survey (NHANES) 2005-2018. The weighted logistic regression model was adopted to explore the association between diet quality scores and overweight, obesity in children and adolescents. Subgroup analysis was also performed based on sex. RESULTS: A total of 9,724 participants were included in children group (2-11 years old), and 5,934 were adolescent group (12-19 years old). All participants were divided into based on the BMI-for-age: underweight and normal, overweight and obesity groups. After adjusting for age, race, poverty-income ratio, maternal smoking during pregnancy and total energy, HEI-2015 and MedDiet scores were related to the risk of overweight in children, and only MedDiet scores remained associated with a decreased risk of obesity in children. MedDiet scores were associated with a decreased risk of overweight, obesity in adolescents, respectively, after adjusting age, sex, race, poverty-income ratio, cotinine, total energy and physical activity. The similar results in male participants were also found. CONCLUSION: Higher MedDiet scores were associated with lower the risk of overweight and obesity, respectively, particularly for male children and adolescents. The higher HEI-2015 scores were also related to the risk of overweight in children.


Assuntos
Sobrepeso , Obesidade Infantil , Criança , Feminino , Gravidez , Adolescente , Masculino , Humanos , Pré-Escolar , Adulto Jovem , Adulto , Sobrepeso/epidemiologia , Sobrepeso/etiologia , Obesidade Infantil/epidemiologia , Obesidade Infantil/etiologia , Inquéritos Nutricionais , Estudos Transversais , Dieta
5.
J Med Internet Res ; 25: e47947, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37751276

RESUMO

BACKGROUND: Mitral regurgitation (MR) and tricuspid regurgitation (TR) are common cardiac conditions with high mortality risks, which can be improved through early intervention. Telehealth services, which allow for remote monitoring of patient conditions, have been proven to improve the health management of chronic diseases, but the effects on MR and TR progression are unknown. OBJECTIVE: This study aimed to explore whether patients receiving telehealth services have less MR and TR progression compared with a control group. We also aimed to identify the determinants of MR and TR progression. METHODS: This single-center retrospective study conducted at the National Taiwan University Hospital compared MR and TR progression (defined as either progression to moderate or greater MR and TR or MR and TR progression by ≥2 grades during the study period) between the telehealth and control groups. Patients had a minimum of 2 transthoracic echocardiograms at least 6 months apart; baseline mild-moderate MR and TR or lower; and no prior surgeries on the mitral or tricuspid valve. Telehealth patients were defined as those who received telehealth services for at least 28 days within 3 months of baseline. Basic demographics, baseline blood pressure measurements, prescribed medication, and Charlson Comorbidity Index components were obtained for all patients. RESULTS: A total of 1081 patients (n=226 in the telehealth group and n=855 in the control group) were included in the study analyses. The telehealth group showed significantly lower baseline systolic blood pressure (P<.001), higher Charlson Comorbidity Index (P=.02), higher prevalence of prior myocardial infarction (P=.01) and heart failure (P<.001), higher beta-blocker (P=.03) and diuretic (P=.04) use, and lower nitrate use (P=.04). Both groups showed similar cardiac remodeling conditions at baseline. Telehealth was found to be neutral for both MR (hazard ratio 1.10, 95% CI 0.80-1.52; P=.52) and TR (hazard ratio 1.27, 95% CI 0.92-1.74; P=.14) progression. Determinants for moderate or greater MR progression included older age, female sex, diuretic use, larger left atrial dimension, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, and lower left ventricular ejection fraction. Determinants of moderate or greater TR progression included older age, female sex, diuretic use, presence of atrial fibrillation, LA dimension, left ventricular end-systolic dimension, and lower left ventricular ejection fraction; statin use was found to be protective. CONCLUSIONS: This is the first study to assess the association between telehealth services and the progression of MR and TR. Telehealth patients, who had more comorbidities, displayed similar MR and TR progression versus control patients, indicating that telehealth may slow MR and TR progression. Determinants of MR and TR progression included easy-to-measure traditional echo parameters of cardiac function, older age, female sex, and atrial fibrillation, which can be incorporated into a telehealth platform and advanced alert system, improving patient outcomes through personalized care.


Assuntos
Fibrilação Atrial , Insuficiência da Valva Tricúspide , Humanos , Feminino , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/terapia , Estudos Retrospectivos , Volume Sistólico , Função Ventricular Esquerda , Diuréticos
7.
New Phytol ; 236(5): 1779-1795, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36093737

RESUMO

The mediator complex is highly conserved in eukgaryotes and is integral for transcriptional responses. Mediator subunits associate with signal-responsive transcription factors (TF) to activate expression of specific signal-responsive genes. As the key TF of Arabidopsis thaliana senescence, ORESARA1 (ORE1) is required for nitrogen deficiency (-N) induced senescence; however, the mediator subunit that associates with ORE1 remains unknown. Here, we show that Arabidopsis MED19a associates with ORE1 to activate -N senescence-responsive genes. Disordered MED19a forms inducible nuclear condensates under -N that is regulated by decreasing MED19a lysine acetylation. MED19a carboxyl terminus (cMED19a) harbors a mixed-charged intrinsically disordered region (MC-IDR) required for ORE1 interaction and liquid-liquid phase separation (LLPS). Plant and human cMED19 are sufficient to form heterotypic condensates with ORE1. Human cMED19 MC-IDR, but not yeast cMED19 IDR, partially complements med19a suggesting functional conservation in evolutionarily distant eukaryotes. Phylogenetic analysis of eukaryotic cMED19 revealed that the MC-IDR could arise through convergent evolution. Our result of MED19 MC-IDR suggests that plant MED19 is regulated by phase separation during stress responses.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Complexo Mediador , Humanos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Complexo Mediador/genética , Complexo Mediador/metabolismo , Nutrientes , Filogenia , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Bioorg Chem ; 127: 106008, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35868106

RESUMO

As the traditional conservative remedy for endometrial carcinoma (EC), progesterone has great limitations due to its poor performance, and a new strategy is urgently needed. Our previous work revealed that the antipsychotic drug chlorpromazine (CPZ) has stronger antitumor activity on EC than progesterone does, which may provide a promising conservative alternative for EC patients. Unfortunately, the severe extrapyramidal symptoms (EPSs) at concentrations (>5 mg/kg) that are required for anticarcinoma activity limited its repurposing. Therefore, a series of novel CPZ derivatives were designed and synthesized to avoid EPS and retain its antitumor activity. Among them, 11·2HCl and 18 displayed greater inhibitory activity by modulating SOS1. Notably, even at a dose of 100 mg/kg, 11·2HCl/18 had little effect on the extrapyramidal system. In conclusion, 11·2HCl and 18 greatly repressed the malignant features of endometrial carcinoma and decreased extrapyramidal side effects compared with the original drug CPZ.


Assuntos
Antipsicóticos , Carcinoma , Antipsicóticos/farmacologia , Antipsicóticos/uso terapêutico , Carcinoma/tratamento farmacológico , Clorpromazina/efeitos adversos , Humanos , Progesterona
9.
Endocr J ; 69(4): 385-397, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-34719526

RESUMO

Promoting white adipose tissue (WAT) "browning" and brown adipose tissue (BAT) activation could contribute to increasing energy expenditure. We explored the mechanisms by which the natural compound rutin induced adipose tissue differentiation and ameliorated obesity in vivo and in vitro. 3T3-L1 preadipocytes were cultured in adipogenic differentiation media with/out rutin. Male C57BL/6 mice (n = 6) were fed a high-fat diet (HFD) for 12 weeks with/out rutin. In HFD-fed mice, rutin treatment significantly inhibited weight gain, improved the metabolic profile of plasma samples, decreased the weights of epididymal WAT (eWAT), inguina WAT (iWAT), and liver, and adipocyte size. Furthermore, rutin also increased the expression of uncoupling protein 1 (Ucp-1) and other thermogenic markers in the WAT and BAT. In 3T3-L1 cells, rutin effectively reduced the formation of lipid droplets, stimulated the expression of thermogenic markers, and reduced the expression of adipogenic genes. Additionally, rutin markedly upregulated the AMP-activated protein kinase (AMPK) pathway, and these effects were diminished by treatment with the AMPK inhibitor compound C (CC). Pretreatment with the calmodulin-dependent protein kinase kinase ß (CaMKKß) inhibitor STO-609 blocked the induction of thermogenic markers in 3T3-L1 cells by rutin. Our results indicated that rutin increased energy consumption, induced WAT "browning" and BAT activation, and thus was a promising target for the development of new therapeutic approaches to improve adipose tissue energy metabolism.


Assuntos
Proteínas Quinases Ativadas por AMP , Tecido Adiposo Marrom , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/farmacologia , Dieta Hiperlipídica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Rutina/metabolismo , Rutina/farmacologia , Termogênese/genética , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
10.
J Biol Chem ; 295(24): 8302-8324, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32332101

RESUMO

Heat shock protein 70 (Hsp70) proteins are a family of ancient and conserved chaperones. Cysteine modifications have been widely detected among different Hsp70 family members in vivo, but their effects on Hsp70 structure and function are unclear. Here, we treated HeLa cells with diamide, which typically induces disulfide bond formation except in the presence of excess GSH, when glutathionylated cysteines predominate. We show that in these cells, HspA1A (hHsp70) undergoes reversible cysteine modifications, including glutathionylation, potentially at all five cysteine residues. In vitro experiments revealed that modification of cysteines in the nucleotide-binding domain of hHsp70 is prevented by nucleotide binding but that Cys-574 and Cys-603, located in the C-terminal α-helical lid of the substrate-binding domain, can undergo glutathionylation in both the presence and absence of nucleotide. We found that glutathionylation of these cysteine residues results in unfolding of the α-helical lid structure. The unfolded region mimics substrate by binding to and blocking the substrate-binding site, thereby promoting intrinsic ATPase activity and competing with binding of external substrates, including heat shock transcription factor 1 (Hsf1). Thus, post-translational modification can alter the structure and regulate the function of hHsp70.


Assuntos
Glutationa/metabolismo , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/metabolismo , Sítios de Ligação , Biotina/metabolismo , Cisteína/metabolismo , Proteínas de Choque Térmico HSP70/genética , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação/genética , Peptídeos/química , Peptídeos/metabolismo , Estabilidade Proteica , Estrutura Secundária de Proteína , Desdobramento de Proteína , Relação Estrutura-Atividade , Especificidade por Substrato
11.
J Med Internet Res ; 23(5): e24346, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34003132

RESUMO

BACKGROUND: Patients with peripheral artery disease (PAD) are at high risk for major cardiovascular events, including myocardial infarction, stroke, and hospitalization for heart failure. We have previously shown the clinical efficacy of a fourth-generation synchronous telehealth program for some patients, but the costs and cardiovascular benefits of the program for PAD patients remain unknown. OBJECTIVE: The telehealth program is now widely used by higher-risk cardiovascular patients to prevent further cardiovascular events. This study investigated whether patients with PAD would also have better cardiovascular outcomes after participating in the fourth-generation synchronous telehealth program. METHODS: This was a retrospective cohort study. We screened 5062 patients with cardiovascular diseases who were treated at National Taiwan University Hospital and then enrolled 391 patients with a diagnosis of PAD. Of these patients, 162 took part in the telehealth program, while 229 did not and thus served as control patients. Inverse probability of treatment weighting (IPTW) based on the propensity score was used to mitigate possible selection bias. Follow-up outcomes included heart failure hospitalization, acute coronary syndrome, stroke, and all-cause readmission during the 1-year follow-up period and through the last follow-up. RESULTS: The mean follow-up duration was 3.1 (SD 1.8) years for the patients who participated in the telehealth program and 3.2 (SD 1.8) for the control group. The telehealth program patients exhibited lower risk of ischemic stroke than did the control group in the first year after IPTW (0.9% vs 3.5%; hazard ratio [HR] 0.24; 95% CI 0.07-0.80). The 1-year composite endpoint of vascular accident, including acute coronary syndrome and stroke, was also significantly lower in the telehealth program group after IPTW (2.4% vs 5.2%; HR 0.46; 95% CI 0.21-0.997). At the end of the follow-up, the telehealth program group continued to exhibit a significantly lower rate of ischemic stroke than did the control group after IPTW (0.9% vs 3.5%; HR 0.52, 95% CI 0.28-0.93). Furthermore, the medical costs of the telehealth program patients were not higher than those of the control group, whether in terms of outpatient, emergency department, hospitalization, or total costs. CONCLUSIONS: The PAD patients who participated in the fourth-generation synchronous telehealth program exhibited lower risk of ischemic stroke events over both mid- and long-term follow-up periods. However, larger-scale and prospective randomized clinical trials are needed to confirm our findings.


Assuntos
Doença Arterial Periférica , Acidente Vascular Cerebral , Telemedicina , Humanos , Doença Arterial Periférica/terapia , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controle
12.
Bioorg Med Chem Lett ; 30(14): 127239, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32527541

RESUMO

Endometrial cancer (EC) is one of the most common and fatal gynecological cancers worldwide, but there is no effective treatment for the EC patients of progesterone resistance. Repurposing of existing drugs is a good strategy to discover new candidate drugs. In this text, perphenazine (PPZ), approved for psychosis therapy, was identified as a potential agent for the treatment of both progesterone sensitive and resistant endometrial cancer for the first time. Specifically, perphenazine exhibited good cell proliferation inhibition in Ishikawa (ISK) and KLE cell lines according to the CCK-8 assay and colony formation assay. It also reduced the cell migration of ISK and KLE cell lines in the light of the transwell migration assay. Annexin-V/PI double staining assay suggested that perphenazine could effectively induce ISK and KLE cell apoptosis. Moreover, results of western blot assay indicated perphenazine obviously inhibited the phosphorylation of Akt. Delightedly, PPZ also could significantly attenuate xenograft tumor growth at both 3 mg/kg and 15 mg/kg in mice without influencing the body weights.


Assuntos
Antineoplásicos/farmacologia , Antipsicóticos/farmacologia , Reposicionamento de Medicamentos , Neoplasias do Endométrio/tratamento farmacológico , Perfenazina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antipsicóticos/síntese química , Antipsicóticos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Neoplasias do Endométrio/patologia , Feminino , Humanos , Estrutura Molecular , Perfenazina/síntese química , Perfenazina/química , Relação Estrutura-Atividade
13.
J Biol Chem ; 293(46): 17663-17675, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30228181

RESUMO

The allosteric coupling of the highly conserved nucleotide- and substrate-binding domains of Hsp70 has been studied intensively. In contrast, the role of the disordered, highly variable C-terminal region of Hsp70 remains unclear. In many eukaryotic Hsp70s, the extreme C-terminal EEVD motif binds to the tetratricopeptide-repeat domains of Hsp70 co-chaperones. Here, we discovered that the TVEEVD sequence of Saccharomyces cerevisiae cytoplasmic Hsp70 (Ssa1) functions as a SUMO-interacting motif. A second C-terminal motif of ∼15 amino acids between the α-helical lid and the extreme C terminus, previously identified in bacterial and eukaryotic organellar Hsp70s, is known to enhance chaperone function by transiently interacting with folding clients. Using structural analysis, interaction studies, fibril formation assays, and in vivo functional assays, we investigated the individual contributions of the α-helical bundle and the C-terminal disordered region of Ssa1 in the inhibition of fibril formation of the prion protein Ure2. Our results revealed that although the α-helical bundle of the Ssa1 substrate-binding domain (SBDα) does not directly bind to Ure2, the SBDα enhances the ability of Hsp70 to inhibit fibril formation. We found that a 20-residue C-terminal motif in Ssa1, containing GGAP and GGAP-like tetrapeptide repeats, can directly bind to Ure2, the Hsp40 co-chaperone Ydj1, and α-synuclein, but not to the SUMO-like protein SMT3 or BSA. Deletion or substitution of the Ssa1 GGAP motif impaired yeast cell tolerance to temperature and cell-wall damage stress. This study highlights that the C-terminal GGAP motif of Hsp70 is important for substrate recognition and mediation of the heat shock response.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Resposta ao Choque Térmico/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/química , Adenosina Trifosfatases/química , Motivos de Aminoácidos , Amiloide/metabolismo , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/química , Príons/metabolismo , Ligação Proteica , Domínios Proteicos , Multimerização Proteica , Proteínas de Saccharomyces cerevisiae/química , alfa-Sinucleína/metabolismo
14.
Cell Mol Life Sci ; 75(8): 1445-1459, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29124308

RESUMO

Hsp70 is a highly conserved chaperone that in addition to providing essential cellular functions and aiding in cell survival following exposure to a variety of stresses is also a key modulator of prion propagation. Hsp70 is composed of a nucleotide-binding domain (NBD) and substrate-binding domain (SBD). The key functions of Hsp70 are tightly regulated through an allosteric communication network that coordinates ATPase activity with substrate-binding activity. How Hsp70 conformational changes relate to functional change that results in heat shock and prion-related phenotypes is poorly understood. Here, we utilised the yeast [PSI +] system, coupled with SBD-targeted mutagenesis, to investigate how allosteric changes within key structural regions of the Hsp70 SBD result in functional changes in the protein that translate to phenotypic defects in prion propagation and ability to grow at elevated temperatures. We find that variants mutated within the ß6 and ß7 region of the SBD are defective in prion propagation and heat-shock phenotypes, due to conformational changes within the SBD. Structural analysis of the mutants identifies a potential NBD:SBD interface and key residues that may play important roles in signal transduction between domains. As a consequence of disrupting the ß6/ß7 region and the SBD overall, Hsp70 exhibits a variety of functional changes including dysregulation of ATPase activity, reduction in ability to refold proteins and changes to interaction affinity with specific co-chaperones and protein substrates. Our findings relate specific structural changes in Hsp70 to specific changes in functional properties that underpin important phenotypic changes in vivo. A thorough understanding of the molecular mechanisms of Hsp70 regulation and how specific modifications result in phenotypic change is essential for the development of new drugs targeting Hsp70 for therapeutic purposes.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Resposta ao Choque Térmico/fisiologia , Príons/metabolismo , Adenosina Trifosfatases/metabolismo , Regulação Alostérica/fisiologia , Sítios de Ligação/fisiologia , Chaperonas Moleculares/metabolismo , Ligação Proteica/fisiologia , Domínios Proteicos/fisiologia , Leveduras/metabolismo
15.
J Med Internet Res ; 21(3): e12369, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30829574

RESUMO

BACKGROUND: Decreased ambient temperature significantly increases office blood pressure, but few studies have evaluated the effect of ambient temperature on home blood pressure. OBJECTIVE: We aimed to investigate the relationship between short-term ambient temperature exposure and home blood pressure. METHODS: We recruited patients with chronic cardiovascular diseases from a telehealth care program at a university-affiliated hospital. Blood pressure was measured at home by patients or their caregivers. We obtained hourly meteorological data for Taipei (temperature, relative humidity, and wind speed) for the same time period from the Central Weather Bureau, Taiwan. RESULTS: From 2009 to 2013, we enrolled a total of 253 patients. Mean patient age was 70.28 (SD 13.79) years, and 66.0% (167/253) of patients were male. We collected a total of 110,715 home blood pressure measurements. Ambient temperature had a negative linear effect on all 3 home blood pressure parameters after adjusting for demographic and clinical factors and antihypertensive agents. A 1°C decrease was associated with a 0.5492-mm Hg increase in mean blood pressure, a 0.6841-mm Hg increase in systolic blood pressure, and a 0.2709-mm Hg increase in diastolic blood pressure. This temperature effect on home blood pressure was less prominent in patients with diabetes or hypertension. Antihypertensive agents modified this negative effect of temperature on home blood pressure to some extent, and angiotensin receptor blockers had the most favorable results. CONCLUSIONS: Short-term exposure to low ambient temperature significantly increased home blood pressure in patients with chronic cardiovascular diseases. Antihypertensive agents may modify this effect.


Assuntos
Anti-Hipertensivos/uso terapêutico , Determinação da Pressão Arterial/métodos , Hipertensão/tratamento farmacológico , Telemedicina/métodos , Temperatura , Idoso , Anti-Hipertensivos/farmacologia , Feminino , Humanos , Internet , Masculino , Estudos Retrospectivos
16.
Biochemistry ; 57(6): 935-944, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29334217

RESUMO

Cancer-suppressing transcription factor p53 is regulated by a wide variety of cellular factors, including many chaperones. The DNA-binding domain (DBD) of p53 is known to interact with the chaperone Hsp90, but the role of other members of the chaperone network, including co-chaperones such as p23, is unknown. Using a combination of nuclear magnetic resonance (NMR) titration, isothermal titration calorimetry, fluorescence anisotropy, and native agarose gel electrophoresis, we have identified a direct interaction between the p53 DBD and Hsp90 co-chaperone p23 that occurs in the absence of Hsp90. The affinity is relatively weak and largely determined by electrostatic interactions between the acidic C-terminal disordered tail of p23 and the two DNA-binding regions of the p53 DBD. We show by NMR and native agarose gel electrophoresis that a p53-specific double-stranded DNA sequence competes successfully with p23 for binding to the p53 DBD. The Hsp90 independence of the interaction between p23 and p53 DBD, together with the competition of p23 versus DNA for p53, raises the intriguing possibility that p23, like other small charged proteins, may affect p53 in hitherto unknown ways.


Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Prostaglandina-E Sintases/metabolismo , Mapas de Interação de Proteínas , Proteína Supressora de Tumor p53/metabolismo , Sítios de Ligação , DNA/metabolismo , Humanos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Proteína Supressora de Tumor p53/química
17.
Mol Plant Microbe Interact ; 31(1): 86-100, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29090655

RESUMO

The viral infection process is a battle between host defense response and pathogen antagonizing action. Several studies have established a tight link between the viral RNA silencing suppressor (RSS) and the repression of salicylic acid (SA)-mediated defense responses, nonetheless host factors directly linking an RSS and the SA pathway remains unidentified. From yeast two-hybrid analysis, we identified an interaction between the potyviral RSS helper-component proteinase (HCPro) and SA-binding protein SABP3. Co-localization and bimolecular fluorescence complementation analyses validated the direct in vivo interaction between Turnip mosaic virus (TuMV) HCPro and the Arabidopsis homologue of SABP3, AtCA1. Additionally, transient expression of TuMV HCPro demonstrated its ability to act as a negative regulator of AtCA1. When the plants of the AtCA1 knockout mutant line were inoculated with TuMV, our results indicated that AtCA1 is essential to restrict viral spreading and accumulation, induce SA accumulation, and trigger the SA pathway. Unexpectedly, the AtCA1 overexpression line also displayed a similar phenotype, suggesting that the constitutive expression of AtCA1 antagonizes the SA pathway. Taken together, our results depict AtCA1 as an essential regulator of SA defense responses. Moreover, the interaction of potyviral HCPro with this regulator compromises the SA pathway to weaken host defense responses and facilitate viral infection.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/virologia , Anidrases Carbônicas/metabolismo , Cisteína Endopeptidases/metabolismo , Inativação Gênica , Potyvirus/metabolismo , Ácido Salicílico/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Arabidopsis/metabolismo , Cisteína Endopeptidases/química , Fluorescência , Técnicas de Inativação de Genes , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas , Ligação Proteica , Proteínas Virais/química
18.
New Phytol ; 219(4): 1480-1491, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29862530

RESUMO

Dispersed H3K27 trimethylation (H3K27me3) of the AGAMOUS (AG) genomic locus is mediated by CURLY LEAF (CLF), a component of the Polycomb Repressive Complex (PRC) 2. Previous reports have shown that the AG second intron, which confers AG tissue-specific expression, harbors sequences targeted by several positive and negative regulators. Using RACE reverse transcription polymerase chain reaction, we found that the AG intron 2 encodes several noncoding RNAs. RNAi experiment showed that incRNA4 is needed for CLF repressive activity. AG-incRNA4RNAi lines showed increased leaf AG mRNA levels associated with a decrease of H3K27me3 levels; these plants displayed AG overexpression phenotypes. Genetic and biochemical analyses demonstrated that the AG-incRNA4 can associate with CLF to repress AG expression in leaf tissues through H3K27me3-mediated repression and to autoregulate its own expression level. The mechanism of AG-incRNA4-mediated repression may be relevant to investigations on tissue-specific expression of Arabidopsis MADS-box genes.


Assuntos
Proteína AGAMOUS de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Íntrons/genética , Folhas de Planta/genética , RNA não Traduzido/genética , Transcrição Gênica , Proteína AGAMOUS de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Correpressoras/metabolismo , Flores/genética , Glucuronidase/metabolismo , Histonas/metabolismo , Proteínas de Homeodomínio/genética , Especificidade de Órgãos/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA não Traduzido/metabolismo , Plântula/genética
19.
J Neurol Neurosurg Psychiatry ; 89(6): 618-626, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29326294

RESUMO

OBJECTIVES: The clinical and epidemiological profiles of Guillain-Barré syndrome (GBS) in southern China have yet to be fully recognised. We aimed to investigate the subtypes of GBS in southern China, compare the clinical features of demyelinating form with that of axonal form and test whether preceding infections and age have influence on the clinical phenotype, disease course and severity of GBS. METHODS: Medical records of patients with a diagnosis of GBS admitted to 31 tertiary hospitals, located in 14 provinces in southern China, from 1 January 2013 to 30 September 2016, were collected and retrospectively reviewed. RESULTS: Finally. 1056 patients, including 887 classic GBS and 169 variants, were enrolled. The 661 classic patients with available electromyographic data were grouped as having acute inflammatory demyelinating polyneuropathy (AIDP, 49.0%), acute motor axonal neuropathy (AMAN, 18.8%), inexcitable (0.9%) and equivocal (31.3%). In contrast to AIDP, patients with AMAN were characterised by earlier nadir (P=0.000), higher Hughes score at nadir (P=0.003) and at discharge (P=0.000). Preceding upper respiratory infections were identified in 369 (34.9%) patients, who were more inclined to develop AIDP (P=0.000) and Miller-Fisher syndrome (P=0.027), whereas gastrointestinal infection were found in 89 (8.4%) patients, who were more prone to develop AMAN (P=0.000), with more severe illness (P=0.001) and longer hospital stay (P=0.009). Children (≤15 years) and the elderly (≥56 years) were more severe at nadir, the elderly had the longest hospital stay (P=0.023). CONCLUSION: AIDP is the predominant form in southern China, which is different from data of northern China. The different subtypes, preceding infection and age of onset can partially determine the disease progression, severity and short-term recovery speed of GBS. CLINICAL TRIAL REGISTRATION: ChiCTR-RRC-17014152.


Assuntos
Síndrome de Guillain-Barré/complicações , Síndrome de Guillain-Barré/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China , Feminino , Síndrome de Guillain-Barré/fisiopatologia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
20.
J Med Internet Res ; 20(1): e23, 2018 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-29367185

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is prevalent in Taiwan and it is associated with high all-cause mortality. We have shown in a previous paper that a fourth-generation telehealth program is associated with lower all-cause mortality compared to usual care with a hazard ratio of 0.866 (95% CI 0.837-0.896). OBJECTIVE: This study aimed to evaluate the effect of renal function status on hospitalization among patients receiving this program and to evaluate the relationship between contract compliance rate to the program and risk of hospitalization in patients with CKD. METHODS: We retrospectively analyzed 715 patients receiving the telehealth care program. Contract compliance rate was defined as the percentage of days covered by the telehealth service before hospitalization. Patients were stratified into three groups according to renal function status: (1) normal renal function, (2) CKD, or (3) end-stage renal disease (ESRD) and on maintenance dialysis. The outcome measurements were first cardiovascular and all-cause hospitalizations. The association between contract compliance rate, renal function status, and hospitalization risk was analyzed with a Cox proportional hazards model with time-dependent covariates. RESULTS: The median follow-up duration was 694 days (IQR 338-1163). Contract compliance rate had a triphasic relationship with cardiovascular and all-cause hospitalizations. Patients with low or very high contract compliance rates were associated with a higher risk of hospitalization. Patients with CKD or ESRD were also associated with a higher risk of hospitalization. Moreover, we observed a significant interaction between the effects of renal function status and contract compliance rate on the risk of hospitalization: patients with ESRD, who were on dialysis, had an increased risk of hospitalization at a lower contract compliance rate, compared with patients with normal renal function or CKD. CONCLUSIONS: Our study showed that there was a triphasic relationship between contract compliance rate to the telehealth program and risk of hospitalization. Renal function status was associated with risk of hospitalization among these patients, and there was a significant interaction with contract compliance rate.


Assuntos
Hospitalização/estatística & dados numéricos , Cooperação do Paciente/estatística & dados numéricos , Insuficiência Renal Crônica/terapia , Telemedicina/métodos , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA