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1.
N Engl J Med ; 388(5): 406-417, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-36577095

RESUMEN

BACKGROUND: Nirmatrelvir-ritonavir has been authorized for emergency use by many countries for the treatment of coronavirus disease 2019 (Covid-19). However, the supply falls short of the global demand, which creates a need for more options. VV116 is an oral antiviral agent with potent activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We conducted a phase 3, noninferiority, observer-blinded, randomized trial during the outbreak caused by the B.1.1.529 (omicron) variant of SARS-CoV-2. Symptomatic adults with mild-to-moderate Covid-19 with a high risk of progression were assigned to receive a 5-day course of either VV116 or nirmatrelvir-ritonavir. The primary end point was the time to sustained clinical recovery through day 28. Sustained clinical recovery was defined as the alleviation of all Covid-19-related target symptoms to a total score of 0 or 1 for the sum of each symptom (on a scale from 0 to 3, with higher scores indicating greater severity; total scores on the 11-item scale range from 0 to 33) for 2 consecutive days. A lower boundary of the two-sided 95% confidence interval for the hazard ratio of more than 0.8 was considered to indicate noninferiority (with a hazard ratio of >1 indicating a shorter time to sustained clinical recovery with VV116 than with nirmatrelvir-ritonavir). RESULTS: A total of 822 participants underwent randomization, and 771 received VV116 (384 participants) or nirmatrelvir-ritonavir (387 participants). The noninferiority of VV116 to nirmatrelvir-ritonavir with respect to the time to sustained clinical recovery was established in the primary analysis (hazard ratio, 1.17; 95% confidence interval [CI], 1.01 to 1.35) and was maintained in the final analysis (median, 4 days with VV116 and 5 days with nirmatrelvir-ritonavir; hazard ratio, 1.17; 95% CI, 1.02 to 1.36). In the final analysis, the time to sustained symptom resolution (score of 0 for each of the 11 Covid-19-related target symptoms for 2 consecutive days) and to a first negative SARS-CoV-2 test did not differ substantially between the two groups. No participants in either group had died or had had progression to severe Covid-19 by day 28. The incidence of adverse events was lower in the VV116 group than in the nirmatrelvir-ritonavir group (67.4% vs. 77.3%). CONCLUSIONS: Among adults with mild-to-moderate Covid-19 who were at risk for progression, VV116 was noninferior to nirmatrelvir-ritonavir with respect to the time to sustained clinical recovery, with fewer safety concerns. (Funded by Vigonvita Life Sciences and others; ClinicalTrials.gov number, NCT05341609; Chinese Clinical Trial Registry number, ChiCTR2200057856.).


Asunto(s)
Antivirales , Tratamiento Farmacológico de COVID-19 , COVID-19 , Adulto , Humanos , Antivirales/administración & dosificación , Antivirales/efectos adversos , Antivirales/uso terapéutico , COVID-19/virología , Tratamiento Farmacológico de COVID-19/métodos , Ritonavir/administración & dosificación , Ritonavir/efectos adversos , Ritonavir/uso terapéutico , SARS-CoV-2 , Administración Oral , Método Simple Ciego , Progresión de la Enfermedad
2.
Int J Clin Pract ; 75(6): e13939, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33336480

RESUMEN

OBJECTIVE: Serum sodium overcorrection and hypernatremia are significant health risks. We conducted a systematic review and meta-analysis to evaluate the risks of vaptans in hypernatremia and serum sodium overcorrection. METHODS: We searched PubMed, Embase, and CENTRAL for randomised controlled trials. We included studies comparing vaptans and placebo with data on hypernatremia and serum sodium overcorrection. The study quality was assessed using the Cochrane Collaboration's risk-of-bias assessment tool. Fixed-effect model meta-analysis was used to pool the data. Different analyses were performed to ensure the accuracy of the results. RESULTS: Twenty-eight studies were included in the meta-analysis of hypernatremia incidence. Treatment with vaptans resulted in a higher risk of hypernatremia than placebo (3.8% vs 1.0%, odds ratio [OR] 2.69; 95% confidence interval [CI] 1.97-3.68). The subgroup with baseline hyponatremia had a lower risk of hypernatremia incidence; however, the use of loop diuretics increased the risk. Fourteen studies were included in the analysis of the incidence of serum sodium overcorrection. A higher risk of serum sodium overcorrection was found in using vaptans vs placebo (4.4% vs 1.4%; OR 2.26; 95% CI 1.32-3.86). CONCLUSION: Vaptans showed higher risks in the incidence of hypernatremia and serum sodium overcorrection than placebo. In addition, combination with loop diuretics increased the risk of hypernatremia. The risk of serum sodium overcorrection should be concerned in patients with hyponatremia and normal serum sodium equally. Using a low dose of vaptans can reduce both risks.


Asunto(s)
Hipernatremia , Hiponatremia , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Sodio
3.
Epidemiol Infect ; 148: e205, 2020 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-32838815

RESUMEN

Sentinel surveillance system plays a key role in screening and monitoring emerging and acute infectious diseases in order to identify the suspected cases in time. During SARS period in 2003, fever clinics emerged in many cities in mainland China with the purpose to screen the suspected SARS patients and to transfer the confirmed cases to designated hospitals for professional management. Shanghai city has reserved the fever clinics and the designated hospitals since then. Hence, clinicians in the front line are able to respond quickly to the emerging COVID-19 outbreak with their accumulated knowledge and experiences from the past. One hundred seventeen fever clinics distributed in various district areas in Shanghai have played a vital 'sentinel' role to fight against the COVID-19 epidemic. Most of suspected patients were identified in fever clinics and thereafter among these suspected patients the COVID-19 cases were confirmed and were isolated quickly to avoid the spread. We would like to share the sentinel roadmap for screening and diagnosis of COVID-19 to medical healthcare workers around the world, especially countries who are facing great challenges to cope with COVID-19 and meanwhile with limited medical resources. These sentinel surveillance strategies will certainly provide insight into the early detection and timely isolation of suspected cases from the others.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , COVID-19 , Diagnóstico Precoz , Humanos , Pandemias , SARS-CoV-2
4.
JAMA Netw Open ; 7(3): e241765, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38477921

RESUMEN

Importance: With the widespread use of anti-SARS-CoV-2 drugs, accumulating data have revealed potential viral load rebound after treatment. Objective: To compare COVID-19 rebound after a standard 5-day course of antiviral treatment with VV116 vs nirmatrelvir-ritonavir. Design, Setting, and Participants: This is a single-center, investigator-blinded, randomized clinical trial conducted in Shanghai, China. Adult patients with mild-to-moderate COVID-19 and within 5 days of SARS-CoV-2 infection were enrolled between December 20, 2022, and January 19, 2023, and randomly allocated to receive either VV116 or nirmatrelvir-ritonavir. Interventions: Participants in the VV116 treatment group received oral 600-mg VV116 tablets every 12 hours on day 1 and 300 mg every 12 hours on days 2 through 5. Participants in the nirmatrelvir-ritonavir treatment group received oral nirmatrelvir-ritonavir tablets with 300 mg of nirmatrelvir plus 100 mg of ritonavir every 12 hours for 5 days. Participants were followed up every other day until day 28 and every week until day 60. Main Outcomes and Measures: The primary outcome was viral load rebound (VLR), defined as a half-log increase in viral RNA copies per milliliter compared with treatment completion. Secondary outcomes included a reduction in the cycle threshold value of 1.5 or more, time until VLR, and symptom rebound, defined as an increase of more than 2 points in symptom score compared with treatment completion. The primary outcome and secondary outcomes were analyzed using the full analysis set. Sensitivity analyses were conducted using the per protocol set. Adverse events were analyzed using the safety analysis set. Results: The full analysis set included 345 participants (mean [SD] age, 53.2 [16.8] years; 175 [50.7%] were men) who received VV116 (n = 165) or nirmatrelvir-ritonavir (n = 180). Viral load rebound occurred in 33 patients (20.0%) in the VV116 group and 39 patients (21.7%) in the nirmatrelvir-ritonavir group (P = .70). Symptom rebound occurred in 41 of 160 patients (25.6%) in the VV116 group and 40 of 163 patients (24.5%) in the nirmatrelvir-ritonavir group (P = .82). Viral whole-genome sequencing of 24 rebound cases revealed the same lineage at baseline and at viral load rebound in each case. Conclusions and Relevance: In this randomized clinical trial of patients with mild-to-moderate COVID-19, viral load rebound and symptom rebound were both common after a standard 5-day course of treatment with either VV116 or nirmatrelvir-ritonavir. Prolongation of treatment duration might be investigated to reduce COVID-19 rebound. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2200066811.


Asunto(s)
Adenosina , COVID-19 , Recurrencia , Adulto , Masculino , Humanos , Persona de Mediana Edad , Femenino , Tratamiento Farmacológico de COVID-19 , China , Ritonavir , SARS-CoV-2 , Adenosina/análogos & derivados
5.
Front Psychol ; 13: 944043, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36312119

RESUMEN

With the increasing number of online charity donations, research on the influencing factors of individual donation behavior has become an important topic. Social interaction information in crowdfunding has become an essential basis for potential backers to make decisions. It provides new research space for charity crowdfunding and social capital theory. The primary purpose of this study is to explore the influence of social capital, social recommendation, and other signals on charity crowdfunding performance. We obtain 4,780 project information on the charity crowdfunding of Sina MicroBlog through data collection procedures. Our research found that both external social capital and internal capital can significantly improve the fundraising performance of crowdfunding projects. Projects with more social recommendations are more likely to obtain financial support. In the case of Medical aid crowdfunding projects, the positive promotion effect of social recommendations on project fundraising ability is enhanced. To get more effective support for crowdfunding projects, it is necessary to pay attention to the construction of social capital and the cultivation of its reputation to obtain the recognition of potential backers.

6.
Cell Calcium ; 43(5): 444-56, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-17854888

RESUMEN

Calmodulin (CaM) is the primary Ca(2+)-sensor that regulates a wide variety of cellular processes in eukaryotes. Although many Ca(2+)/CaM-binding proteins have been identified, very few such proteins could be found from the genome-wide protein-protein interaction maps of Caenorhabditis elegans constructed by yeast two-hybrid screening. Using a genotype-phenotype conjugation method called mRNA-display, we performed a selection for Ca(2+)/CaM-binding proteins from a proteome library of C. elegans. The method allowed the identification of 9 known and 47 previously uncharacterized Ca(2+)-dependent CaM-binding proteins from the adult worm proteome. The Ca(2+)/CaM-binding properties of these proteins were characterized and their binding motifs were identified. The availability of such information could facilitate our understanding of the signaling pathways mediated by Ca(2+)/CaM in C. elegans. Due to its simplicity and efficiency, the method could be readily applied to examine the Ca(2+)-dependent binding partners of numerous other Ca(2+)-binding proteins, which may play important roles in many signaling pathways in C. elegans.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Unión a Calmodulina/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/aislamiento & purificación , Calcio/metabolismo , Calmodulina/metabolismo , Proteínas de Unión a Calmodulina/química , Proteínas de Unión a Calmodulina/aislamiento & purificación , Línea Celular , Humanos , Datos de Secuencia Molecular , Proteoma/metabolismo , Proteómica , Homología de Secuencia de Aminoácido
7.
J Diabetes Investig ; 7(2): 212-8, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-27042273

RESUMEN

AIMS/INTRODUCTION: Chemokine ligand 5 (CCL5) is a member of the CC-chemokine family expressed in various organs. It contributes to the migration of monocytes/macrophages into injured vascular walls by binding with its receptor chemokine receptor 5 (CCR5). Many studies have accessed the association between CCL5/CCR5 gene promoter polymorphisms and diabetic microvascular complications (DMI). However, the results are conflicting and inconclusive. The aim of the present study was to evaluate the association more precisely. MATERIALS AND METHODS: Trials were retrieved through PubMed, Embase, Medline, China National Knowledge Infrastructure, Web of Science and Cochrane database without restrictions on language. The pooled odds ratio (OR) and 95% confidence interval (CI) were used to describe the strength of association with DMI. RESULTS: Data were obtained from 11 case-control studies that included 2,737 DMI patients and 2,435 diabetic control subjects. In the overall analysis, the CCL5-403 G/A and CCL5-28 C/G gene polymorphisms were not significantly associated with the risk of DMI. However, CCR5-59029 G/A was an independent risk factor of DMI in a dominant model (OR 1.77, 95% CI 1.06-2.97). Subgroup analysis showed that the risk of the CCR5 59029A-positive genotype was significant in Asians (OR 2.08, 95% CI 1.68-2.57). In addition, the CCR5 59029A-positive genotype was associated with increased risk of albuminuria. CONCLUSIONS: There were no associations of CCL5 gene promoter polymorphism with the risk of DMI. However, the 59029A polymorphism in CCR5 might affect individual susceptibility for DMI.


Asunto(s)
Quimiocina CCL5/genética , Angiopatías Diabéticas/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Receptores CCR5/genética , Estudios de Casos y Controles , Humanos , Microvasos/patología , Oportunidad Relativa , Factores de Riesgo
8.
Int J Environ Res Public Health ; 12(7): 8023-33, 2015 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-26184271

RESUMEN

BACKGROUND: Many studies have evaluated the association between matrix metalloproteinase 9 (MMP9) gene promoter polymorphism and diabetic microvascular complications. However, the results are conflicting and inconclusive. The aim of this meta-analysis was to evaluate the association more precisely. MATERIALS AND METHODS: Studies were retrieved from the PubMed, Embase, Medline, China National Knowledge Infrastructure, Web of Science, and Cochrane databases. All statistical analyses were performed using Review Manager 5.2. RESULTS: Data were abstracted from four case-control studies that included 446 patients with diabetic microvascular complications and 496 diabetic control subjects. The MMP9-1562 C/T genotype was significantly associated with the risk of diabetic nephropathy after stratification by specific type of microvascular complication (CT + TT vs. CC: OR = 0.42, 95% CI = 0.26-0.69, p = 0.0006; TT vs. CC + CT: OR = 0.37, 95% CI = 0.19-0.76, p = 0.006). CONCLUSIONS: This study adds to the evidence that MMP9-1562 T gene mutation might reduce the risk of diabetic nephropathy.


Asunto(s)
Angiopatías Diabéticas/prevención & control , Metaloproteinasa 9 de la Matriz/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Adulto , Anciano , Estudios de Casos y Controles , China , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Mutación , Riesgo
9.
Mol Cancer ; 3: 14, 2004 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-15125777

RESUMEN

BACKGROUND: CHK2 kinase is a tumor suppressor that plays important role in DNA damage signaling, cell cycle regulation and DNA damage induced apoptosis. CHK2 kinase expression was known to be ubiquitous in mammalian cells. CHK2-/- cells were remarkably resistant to DNA damage induced apoptosis, mimicking the clinical behavior of non-small cell lung cancer to conventional chemo and radiation therapy. RESULT: We reported that the CHK2 expression is diminished or absent in both non-small cell lung cancer (NSCLC) cell lines and clinical lung cancer tumor specimens. The absent CHK2 expression in NSCLC was due to hypermethylation of the CHK2 gene promoter, preventing from binding of a transcriptional factor, leading to silence of the CHK2 gene transcription. CONCLUSION: Since the CHK2 null mice showed a remarkable radioresistance, which bear significant similarity to clinical behavior of NSCLC, down-regulation of CHK2 kinase expression by CHK2 gene silencing and methylation in non-small cell lung cancer suggest a critical role of CHK2 kinase in DNA damage induced apoptosis and a novel mechanism of the resistance of NSCLC to DNA damage based therapy.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/enzimología , Metilación de ADN , Regulación Enzimológica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias Pulmonares/enzimología , Regiones Promotoras Genéticas/fisiología , Proteínas Serina-Treonina Quinasas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Quinasa de Punto de Control 2 , Cisplatino/administración & dosificación , Cisplatino/metabolismo , Daño del ADN/genética , ADN de Neoplasias/genética , ADN de Neoplasias/metabolismo , Femenino , Silenciador del Gen , Humanos , Inmunohistoquímica/métodos , Concentración 50 Inhibidora , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Neoplasias Ováricas/enzimología , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Regiones Promotoras Genéticas/genética , Unión Proteica/genética , Proteínas Serina-Treonina Quinasas/inmunología , ARN Mensajero/metabolismo , ARN Neoplásico/metabolismo , Factores de Transcripción/metabolismo
10.
J Med Chem ; 47(9): 2208-18, 2004 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-15084119

RESUMEN

This study evaluated (18)F-labeled IMPY [6-iodo-2-(4'-N,N-dimethylamino)phenylimidazo[1,2-a]pyridine] derivatives as agents for imaging beta-amyloid plaque with positron emission tomography (PET). The precursor for radiolabeling and reference compounds was synthesized in up to five steps from commercially accessible starting materials. One of the two N-methyl groups of IMPY was substituted with either a 3-fluoropropyl (FPM-IMPY) or a 2-fluoroethyl (FEM-IMPY) group. FPM-IMPY and FEM-IMPY were found to have moderate affinity for Abeta-aggregates with K(i) = 27 +/- 8 and 40 +/- 5 nM, respectively. A "one-pot" method for (18)F-2-fluoroethylation and (18)F-3-fluoropropylation of the precursor was developed. The overall decay-corrected radiochemical yields were 26-51%. In PET experiments with normal mouse, high uptake of activity was obtained in the brain after iv injection of each probe: 6.4% ID/g for [(18)F]FEM-IMPY at 1.2 min, and 5.7% ID/g for [(18)F]FPM-IMPY at 0.8 min. These values were similar to those of [(123)I/(125)I]IMPY (7.2% ID/g at 2 min). Polar and nonpolar radioactive metabolites were observed in both plasma and brain homogenates after injection of [(18)F]FEM or [(18)F]FPM-IMPY. In contrast to the single-exponential washout of [(123)I/(125)I]IMPY, the washouts of brain activity for the two fluorinated analogues were biphasic, with an initial rapid phase over 20 min and a subsequent much slower phase. Residual brain activity at 2 h, which may represent polar metabolites trapped in the brain, was 4.5% ID/g for [(18)F]FEM-IMPY and 2.1% ID/g for [(18)F]FPM-IMPY. Substantial skull uptake of [(18)F]fluoride was also clearly observed. With a view to slow the metabolism of [(18)F]FEM-IMPY, an analogue was prepared with deuteriums substituted for the four ethyl hydrogens. However, D(4)-[(18)F]FEM-IMPY showed the same brain uptake and clearance as the protio analogue. Metabolism of the [(18)F]FEM-IMPY was appreciably slower in rhesus monkey than in mouse. Autoradiography of postmortem brain sections of human Alzheimer's disease patients with [(18)F]FEM-IMPY showed high displaceable uptake in gray matter and low nonspecific binding in the white matter. This study demonstrates that the IMPY derivatives have favorable in vivo brain pharmacokinetics and a moderate affinity for imaging beta-amyloid plaques; however, further improvements are needed to reduce radioactive metabolites, increase binding affinity, and reduce lipophilicity.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides/metabolismo , Imidazoles/síntesis química , Piridinas/síntesis química , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/química , Animales , Autorradiografía , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Cromatografía Liquida , Femenino , Radioisótopos de Flúor , Humanos , Imidazoles/metabolismo , Técnicas In Vitro , Marcaje Isotópico , Ligandos , Macaca mulatta , Masculino , Ratones , Persona de Mediana Edad , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Piridinas/metabolismo , Espectrometría de Masa por Ionización de Electrospray , Distribución Tisular , Tomografía Computarizada de Emisión
11.
Chin Med J (Engl) ; 125(23): 4296-300, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23217403

RESUMEN

BACKGROUND: Amputation-free survival (AFS) has been recommended as the gold standard for evaluating No-Option Critical Limb Ischemia (NO-CLI) therapy. Early-phase clinical trials suggest that autologous bone-marrow derived cells (BMCs) transplantation may have a positive effect on patients with NO-CLI, especially decreasing the incidence of amputation. However, the BMCs therapeutic efficacy remains controversial and whether BMCs therapy is suitable for all CLI patients is unclear. METHODS: We conducted a meta-analysis using data from randomized controlled trials (RCTs) by comparing autologous BMCs therapy with controls in patients with critical limb ischemia, and the primary endpoint is the incidence of amputation. Pubmed, EBSCO and the Cochrane Central Register of Controlled Trials (to approximately July 25, 2012) were searched. RESULTS: Seven RCTs with 373 patients were enrolled in the meta-analysis. Because serious disease was the main reason leading to amputation in one trial, six studies with 333 patients were finally included in the meta-analysis. Pooling the data of the final six studies, we found that BMCs therapy significantly decreased the incidence of amputation in patients with CLI (odds ratio (OR), 0.37; 95% confidence interval (CI), 0.22 to 0.62; P = 0.0002), and the efficacy had not significantly declined within 6 months after BMCs were transplanted; OR, 0.33; 95%CI, 0.16 to 0.70; P = 0.004 within 6 months and OR, 0.30; 95%CI, 0.11 to 0.79; P = 0.01 within 3 months. The rate of AFS after BMCs therapy was significantly increased in patients with Rutherford class 5 CLI (OR 3.28; 95%CI, 1.12 to 9.65; P = 0.03), while there was no significant improvement in patients with Rutherford class 4 (OR 0.35; 95%CI, 0.05 to 2.33; P = 0.28) compared with controls. The BMCs therapy also improved ulcer healing (OR, 5.83; 95%CI, 2.37 to 14.29; P = 0.0001). CONCLUSIONS: Our analysis suggests that autologous BMCs therapy has a beneficial effect in decreasing the incidence of amputation and the efficacy does not decrease significantly within 6 months after BMCs transplantation. Patients with Rutherford class 5 are suitable for BMCs therapy, while the efficiency in patients with Rutherford 4 needs further evaluation.


Asunto(s)
Trasplante de Médula Ósea/métodos , Isquemia/terapia , Extremidad Inferior/patología , Trasplante Autólogo/métodos , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
12.
Proc Natl Acad Sci U S A ; 104(36): 14294-9, 2007 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-17728405

RESUMEN

Caspases are proteolytic enzymes that are essential for apoptosis. Understanding the many discrete and interacting signaling pathways mediated by caspases requires the identification of the natural substrate repertoire for each caspase of interest. Using an amplification-based protein selection technique called mRNA display, we developed a high-throughput screen platform for caspase family member specific substrates on a proteome-wide scale. A large number of both known and previously uncharacterized caspase-3 substrates were identified from the human proteome. The proteolytic features of these selected substrates, including their cleavage sites and specificities, were characterized. Substrates that were cleaved only by caspase-8 or granzyme B but not by caspase-3, were readily selected. The method can be widely applied for efficient and systematic identification of the family member specific natural substrate repertoire of any caspase in an organism of interest, in addition to that of numerous other proteases with high specificity.


Asunto(s)
Caspasas/metabolismo , Proteoma/metabolismo , Secuencia de Aminoácidos , Animales , Apoptosis/efectos de los fármacos , Camptotecina/farmacología , Línea Celular , Cricetinae , Granzimas/metabolismo , Humanos , Proteoma/clasificación , ARN Mensajero/genética , Especificidad por Sustrato
13.
Biochem Biophys Res Commun ; 328(2): 567-72, 2005 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-15694385

RESUMEN

Checkpoint kinase 2 (Chk2) is one of the critical kinases governing the cell cycle checkpoint, DNA damage repair, and cell apoptosis in response to DNA damaging signals. In the present report, we demonstrate that Chk2 kinase is degraded at the protein level in response to cisplatin through ubiquitin-proteasome pathway. This degradation was independent of the Thr68 phosphorylation, ATM kinase, and BRCA1 tumor suppressor. Examination of Chk2 protein revealed a decreased expression of Chk2 protein in cisplatin-resistant ovarian cancer cell lines, suggesting that degradation or decreased expression of Chk2 is partially responsible for chemo-resistance. Site-directed mutation of the putative destruction box in the Chk2 protein did not affect the Chk2 degradation induced by cisplatin. Therefore, these results are the first to indicate a novel mechanism of regulating Chk2 in cisplatin-induced resistance of cancer cells.


Asunto(s)
Cisplatino/administración & dosificación , Daño del ADN , Resistencia a Antineoplásicos/efectos de los fármacos , Neoplasias Ováricas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Línea Celular Tumoral , Quinasa de Punto de Control 2 , Activación Enzimática , Femenino , Humanos , Mutagénesis Sitio-Dirigida , Neoplasias Ováricas/tratamiento farmacológico , Proteínas Serina-Treonina Quinasas/genética
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