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1.
Nat Commun ; 10(1): 3213, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324785

RESUMO

Ribonucleotide reductase (RNR) catalyzes the de novo synthesis of deoxyribonucleoside diphosphates (dNDPs) to provide dNTP precursors for DNA synthesis. Here, we report that acetylation and deacetylation of the RRM2 subunit of RNR acts as a molecular switch that impacts RNR activity, dNTP synthesis, and DNA replication fork progression. Acetylation of RRM2 at K95 abrogates RNR activity by disrupting its homodimer assembly. RRM2 is directly acetylated by KAT7, and deacetylated by Sirt2, respectively. Sirt2, which level peak in S phase, sustains RNR activity at or above a threshold level required for dNTPs synthesis. We also find that radiation or camptothecin-induced DNA damage promotes RRM2 deacetylation by enhancing Sirt2-RRM2 interaction. Acetylation of RRM2 at K95 results in the reduction of the dNTP pool, DNA replication fork stalling, and the suppression of tumor cell growth in vitro and in vivo. This study therefore identifies acetylation as a regulatory mechanism governing RNR activity.

2.
Curr Med Sci ; 39(4): 663-669, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31347006

RESUMO

This study aimed to evaluate the satisfaction of village doctors to essential medicines list (EML) and accessibility of essential medicines (EMs) distribution to improve the implementation of EML in village clinics. A total of 422 village doctors from five counties in three provinces of China were surveyed by questionnaires. Logistic regression analysis was conducted to identify the main factors associated with village doctors' evaluation of EML. The results showed that village doctors had a negative evaluation in satisfaction level of EML to village-based care and accessibility of EM distribution. The government should adjust EML regularly based on the actual health status of local villagers in China and focus on adding appropriate drugs that meet the needs of villagers with chronic disease. The local government should also attach importance to the distribution of EMs and maintain their supply in village clinics.

3.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1882-1888, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342717

RESUMO

The thrombus is a deposit that is formed on the surface of the endovascular or at the site of repair,and known as the main complication of cardiovascular disease and the cause of death. At the same time,thrombus is mainly treated by the following three ways: anticoagulation,anti-platelet aggregation and thrombolysis. In this study,the chemical constituents of seven traditional Chinese medicines in the Xixian Tongshuan Preparation were collected to construct a component database. Subsequently,the pharmacophore were used to screen out the component database,and molecular docking was used to screen out the results of pharmacophore for explaining the material basis and mechanism that Xixian Tongshuan Preparation exerts anti-thrombotic activity by inhibiting platelet aggregation. First of all,P2 Y12,GPⅡb/Ⅲa and PAR1 were selected as study vectors,the optimal models of inhibitors were obtained respectively through verification and evaluation of the pharmacophore models. Afterwards,the component database was screened out by the optimal pharmacophore models of PAR1,P2 Y12 and GP Ⅱ b/Ⅲ a,and the molecular docking method was used to further refine the screening results. The screening results indicated that the anti-platelet aggregation effect of Xixian Tongshuan Preparation was correlated with the inhibition of P2 Y12,PAR1 and GPⅡb/Ⅲa expressions with saffower yellower,hirudin and candidin and notoginseng triterpenes,folinic acid,respectively. The material basis and mechanism of anti-platelet aggregation of Xixian Tongshuan Preparation provided a theoretical basis for the clinical use of the preparation and the lead compounds for the development of anti-platelet aggregation drugs.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Inibidores da Agregação de Plaquetas/farmacologia , Agregação Plaquetária , Trombose , Bases de Dados de Produtos Farmacêuticos , Humanos , Simulação de Acoplamento Molecular
4.
Zhongguo Zhong Yao Za Zhi ; 44(12): 2572-2579, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359726

RESUMO

Inflammatory response is caused by exogenous and endogenous stimuli,resulting in a non-specific resistance reaction.After acute ischemic cerebral infarction,inflammatory factors gather and adhere in the ischemic area of leukocyte infiltration,and the released inflammatory factors causes the injury cascade,aggravate the brain tissue damage and the symptoms of neurological deficits,and hinder the repair of brain neurons and the recovery of nerve function. In this paper,the key targets in the arachidonic acid metabolic pathway were studied. The Hiphop pharmacophore model of s PLA2-ⅡA and COX-2 inhibitors was built. According tothe two previously constructed 5-LOX and LTA4 H target inhibitors,the pharmacophore model was used to initially screen out the composition database of all of 13 traditional Chinese medicines in Xixian Tongshuan Preparation. The molecular matching study was carried out by selecting the matching value greater than 0. 6,and the component with the CDOCKER score greater than 80% of the original ligand score was used as the potential active inhibitor of the target. Considering the pharmacophore matching value,the molecular docking score and the interaction between the components and the target,one Chuanxiong component and one safflower component were selected as potential inhibitors of s PLA2-ⅡA; two Chuanxiong components,two Panax notoginseng,one safflower component,one angelica component,one valerian component were taken as a potential inhibitor of COX-2; two Gentiana components,one safflower component,one valerian component,one P. notoginseng component and one Angelica component were taken as potential inhibitors of 5-LOX; and two Gentiana components,two Chuanxiong components,and two safflower components were taken as potential inhibitors of LTA4 H. This study screened out the potential inhibitors of the four targets in a high-efficiency and low-cost manner,and explained that Xixian Tongshuan Preparation showed an effect in the treatment of inflammatory responses caused by ischemic stroke by acting both LOX pathway and COX pathway in the metabolic pathway.


Assuntos
Anti-Inflamatórios/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Simulação de Acoplamento Molecular , Ligantes , Medicina Tradicional Chinesa
5.
Zhongguo Zhong Yao Za Zhi ; 44(11): 2353-2358, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31359663

RESUMO

In this paper, Xixian Tongshuan Preparation was used as the research object, and all the chemical components of the 13 traditional Chinese medicines were collected. The target finding technique was used to obtain the key targets of the neuroprotective effect of Xixian Tongshuan Preparation, including 5 glutamate receptors, TGFR-1 and VEGFR-2. Molecular docking technology was used to screen out the potential active components of the above targets and to analyze their mechanism of action. It was found that single component, such as neo-complanatoside and neo-carthamin, in Xixian Tongshuan Preparation could simultaneously act on different targets. The chemical constituents in Ligusticum chuanxiong, Angelica sinensis, Carthamus tinctorius, and Panax pseudo-ginseng could simultaneously act on different neuroprotective-related targets, which reflected the application of multi-components to multi-targets. Point and multiple sites played a key role in protecting neurons against cerebral ischemic injury. This study explains the multi-target mechanism of anti-cerebral ischemic injury in neuroprotection at the molecular level, and provides a certain direction for the clinical application and experimental research of Xixian Tongshuan Preparation.


Assuntos
Isquemia Encefálica , Infarto Cerebral , Medicamentos de Ervas Chinesas/farmacologia , Fármacos Neuroprotetores/farmacologia , Compostos Fitoquímicos/farmacologia , Humanos , Simulação de Acoplamento Molecular
6.
Curr Protein Pept Sci ; 20(8): 789-798, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31060483

RESUMO

Intracranial aneurysms (IA) are a huge threat to human health, with a global incidence rate of 0.65-8.4%. Although the microsurgical and interventional techniques have made profound progression in treating IA, the relatively high rate of complications and recurrence are still not satisfactory. Thus, there is a need to elucidate its molecular mechanism. Numerous studies have identified the close relationship between hemodynamic-induced inflammation and development of IA. Indeed, the dysfunction of endothelial cells, smooth muscle cells, macrophages and lymphocytes, as well as their secreted cytokines, collectively contribute to the formation, growth and rupture of IA. Furthermore, the immune system has also been identified to participate in the development of IA. This review will explore the mechanisms of various inflammatory cells and significant cytokines, providing a new perspective in the clinical treatment of IA.


Assuntos
Hemodinâmica , Aneurisma Intracraniano/metabolismo , Animais , Citocinas/metabolismo , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Aneurisma Intracraniano/imunologia , Aneurisma Intracraniano/patologia
7.
Zhongguo Zhong Yao Za Zhi ; 44(7): 1436-1441, 2019 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-31090302

RESUMO

Atherosclerosis is the main cause of stroke, and dyslipidemia is the most important risk factor for atherosclerosis. In this paper, pharmacophore and molecular docking models of eight key lipid-lowering targets, namely NPC1 L1, HMG-CoA reductase, SQS, MTP, CETP, PPARα, LXRα and LXRß, were used to screen out the small molecular database of traditional Chinese medicine(TCM), which was made up of ingredients of thirteen Chinese herbal medicines contained in Xixian Tongshuan Preparation. The screening results indicated that the preparation could showed an effect in regulating lipid on target NPC1 L1, HMG-CoA reductase, LXRß and SQS through four groups of potential active compounds, namely prupersin A in peach kernel and suffruticoside A in gastrodiaelata, limocitrin-ß-D-glucoside in Ligusticum chuanxiong, 2'-(2,3-dihydroxybenzoyl)-sweroside in Pinellia ternate and quercitrin in Panax notoginseng, 4-tert-butyl-2-[(5-tert-butyl-2-hydroxy-phenyl)methoxy-methyl]-6-(hydroxymethyl)phenol in Gastrodia elata. Moreover, the properties and extraction process of the most potentialactive compounds were consistent with the preparation process of Xixian Tongshuan Capsules, which indicated that the capsule had more advantages than the pill in the existing two dosage forms of Xixian Tongshuan Preparation. This study analyzed the pharmacodynamic basis and mechanism of Xixian Tongshuan Capsules in regulating lipid for treating stroke, and provided evidence for its further research and clinical application.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Metabolismo dos Lipídeos , Simulação de Acoplamento Molecular , Bases de Dados de Compostos Químicos , Lipídeos , Medicina Tradicional Chinesa
8.
Neurobiol Learn Mem ; 161: 37-45, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30735789

RESUMO

Repetitive anodal transcranial direct current stimulation (tDCS) in a rat model of Alzheimer's disease (AD) has been shown to have distinct neuroprotective effects. Moreover, the effects of anodal tDCS not only occur during the stimulation but also persist after the stimulation has ended (after-effects). Here, the duration of the after-effects induced by repetitive anodal tDCS was investigated based on our previous studies. Adult male Sprague-Dawley rats were divided into three groups: a sham group, a ß-amyloid (Aß) group (AD group) and a stimulation group (ATD group). Aß was injected into the bilateral hippocampi of the rats in the AD and ATD groups to produce the AD model. Rats in the ATD group underwent 10 sessions of anodal tDCS, and the after-effects of repetitive anodal tDCS were evaluated by behavioral and histological analyses. A Morris water maze (MWM) was utilized on a monthly basis to assess spatial learning and memory abilities. The ATD group showed shorter escape latencies and more platform region crossings than the AD group. Hippocampal choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) immunohistochemical analyses were carried out after the last MWM assessment. The immunohistochemistry results showed notable differences among the groups, particularly between the AD and ATD groups. This study reveals that repetitive anodal tDCS can not only improve cognitive function and memory performance but also has long-term after-effects that persist for 2 months.

9.
J Neurol Sci ; 396: 240-246, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529801

RESUMO

Ischemic stroke is one of the most common sources of mortality in the world. Researchers have been trying to find a complementary therapy to treat ischemic stroke in order to improve its prognosis and expand the therapeutic window for reperfusion treatment. For this reason, many experimental and clinical trials studying the effects of hydrogen against ischemic stroke have been published. Hydrogen gas has been found to eliminate hydroxyl free radical and peroxynitrite anions as well as producing therapeutic effect in patients with ischemic stroke. Many studies have been published illustrating its anti-oxidative, anti-inflammatory and anti-apoptotic effects. The purpose of this article is to review the literature concerning treatment of cerebral I/R injury or ischemic stroke with hydrogen therapy. Specifically, we will examine the appropriate laboratory methods, mechanisms of hydrogen therapy, and outcomes of relevant clinical trials. We conclude this review with a discussion on future investigations of hydrogen therapy to treat ischemic stroke.


Assuntos
Antioxidantes/uso terapêutico , Hidrogênio/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Isquemia Encefálica/complicações , Humanos , Acidente Vascular Cerebral/etiologia
10.
Bioorg Med Chem Lett ; 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30389289

RESUMO

A new series of novel cinnamic acyl sulfonamide derivatives were designed and synthesized and evaluated their anti-tubulin polymerization activities and anticancer activities. One of these compounds, compound 5a with a benzdioxan group, was observed to be an excellent tubulin inhibitor (IC50 = 0.88 µM) and display the best antiproliferative activity against MCF-7 with an IC50 value of 0.17 µg/mL. Docking simulation was performed to insert compound 5a into the crystal structure of tubulin at colchicine binding site to determine the probable binding model. 3D-QSAR model was also built to provide more pharmacophore understanding that could be used to design new agents with more potent anti-tubulin polymerization activity.

11.
Eur J Med Chem ; 162: 132-146, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30445263

RESUMO

Stroke is a central nervous system disease that seriously affects people's quality of life and has the second highest rate of morbidity and mortality in the world. At present, clinical treatment strategies for acute ischemic stroke are mainly thrombolytic and thrombectomy therapy. However, these strategies are not able to protect patients from ischemic injuries. Therefore, treatment should further focus on methods that improve the survival rate of neurons around the ischemic area and neurological function. This article reviews current research and developments regarding small molecular compounds, including natural products and newly synthesized compounds that have neuroprotective effects and potential molecular targets for the recovery of post-ischemic stroke neural function that have been identified through lab investigations conducted during the last five years. Although pre-clinical studies of these compounds may not be immediately successful, current findings suggest that these therapeutic targets and neuroprotective agents are promising.

12.
Artigo em Inglês | MEDLINE | ID: mdl-30152884

RESUMO

BACKGROUND: Primary immunodeficiency disorders (PID) is a group of heterogeneous diseases mainly characterized by severe and recurrent infections and an increased susceptibility to lymphoproliferative, atopic and autoimmune conditions. The clinical diagnosis should preferably be complemented by a genetic diagnosis. To date, PID-related reports from China seldom attempt to make a genetic test for their patients. METHODS: Our study aims to evaluate demographic data, clinical manifestations and molecular diagnosis of PID patients from southern China. Moreover, by comparison with previous reports, we provide a picture of the current status of PID in mainland China. A total number of 160 pediatric PID patients (106 males and 54 females) were enrolled and targeted next-generation sequencing was conducted using 269 PID related genes and subsequently confirmed by Sanger sequencing and familial segregation analysis. RESULT: The autoinflammatory disease group was the most common subcategory of PID (20%), followed by immune dysregulation (17.5%) and combined immunodeficiencies (16.2%). Antibody deficiency disorders were identified in only 11.9% of the cohort. The putative causative gene was identified in 70 patients (43.8%) and an X-linked pattern was found in 45.7% of the genetically diagnosed patients. CONCLUSION: The current study provides the first collective study of PID phenotypes and genotypes in south China, and provides a strong argument for the diagnostic application of targeted next generation sequencing panels in patients with suspected PID. This article is protected by copyright. All rights reserved.

13.
Int J Mol Sci ; 19(6)2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29925792

RESUMO

The abnormal self-assembly of the amyloid-β peptide into toxic β-rich aggregates can cause Alzheimer’s disease. Recently, it has been shown that small gold nanoparticles (AuNPs) inhibit Aβ aggregation and fibrillation by slowing down the nucleation process in experimental studies. However, the effects of AuNPs on Aβ oligomeric structures are still unclear. In this study, we investigate the conformation of Aβ(16-22) tetramers/octamers in the absence and presence of AuNPs using extensive all-atom molecular-dynamics simulations in explicit solvent. Our studies demonstrate that the addition of AuNPs into Aβ(16-22) solution prevents β-sheet formation, and the inhibition depends on the concentration of Aβ(16-22) peptides. A detailed analysis of the Aβ(16-22)/Aβ(16-22)/water/AuNPs interactions reveals that AuNPs inhibit the β-sheet formation resulting from the same physical forces: hydrophobic interactions. Overall, our computational study provides evidence that AuNPs are likely to inhibit Aβ(16-22) and full-length Aβ fibrillation. Thus, this work provides theoretical insights into the development of inorganic nanoparticles as drug candidates for treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/química , Ouro/química , Nanopartículas Metálicas/química , Agregação Patológica de Proteínas/metabolismo , Relação Dose-Resposta a Droga , Ouro/uso terapêutico , Humanos , Interações Hidrofóbicas e Hidrofílicas , Simulação de Dinâmica Molecular , Água/química
14.
IUBMB Life ; 70(7): 642-648, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29707886

RESUMO

We aimed to investigate the role of telomerase reverse transcriptase (TERT) in hepatocellular cancer (HCC) cells. R software was used for differential expressed gene analysis. Western blot and quantitative real time polymerase chain reaction (qRT-PCR), respectively, were used to detect protein expression and mRNA level of TERT in tumor cell lines. Real-time quantitative telomeric repeat amplification protocol assay, MTT assay, colony formation assay, and flow cytometry (FCM) assay were used to analyze the telomerase activity, viability, proliferation, cell cycle progression and apoptosis of HCC cells. The proliferation ratio of HCC cells transfected with TERT-siRNA was significantly decreased compared with control group. Plate clone results suggested that the number of colonies also decreased in TERT-siRNA group. FCM results showed that more cells were arrested in G0/G1 phase and apoptosis rate increased in TERT-siRNA group compared with control group. TERT suppression inhibited cell proliferation but promoted cell cycle arrest and cell apoptosis. © 2018 IUBMB Life, 70(7):642-648, 2018.

15.
PLoS Negl Trop Dis ; 12(4): e0006417, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29668683

RESUMO

Zika virus (ZIKV) is primarily transmitted by Aedes mosquitoes in the subgenus Stegomyia but can also be transmitted sexually and vertically in humans. STAT1 is an important downstream factor that mediates type I and II interferon signaling. In the current study, we showed that mice with STAT1 knockout (Stat1-/-) were highly susceptible to ZIKV infection. As low as 5 plaque-forming units of ZIKV could cause viremia and death in Stat1-/- mice. ZIKV replication was initially detected in the spleen but subsequently spread to the brain with concomitant reduction of the virus in the spleen in the infected mice. Furthermore, ZIKV could be transmitted from mosquitoes to Stat1-/- mice back to mosquitoes and then to naïve Stat1-/- mice. The 50% mosquito infectious dose of viremic Stat1-/- mouse blood was close to 810 focus-forming units (ffu)/ml. Our further studies indicated that the activation of macrophages and conventional dendritic cells were likely critical for the resolution of ZIKV infection. The newly developed mouse and mosquito transmission models for ZIKV infection will be useful for the evaluation of antiviral drugs targeting the virus, vector, and host.


Assuntos
Aedes/virologia , Modelos Animais de Doenças , Mosquitos Vetores/virologia , Fator de Transcrição STAT1/genética , Infecção por Zika virus/transmissão , Zika virus/fisiologia , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Viremia , Infecção por Zika virus/virologia
16.
Oncotarget ; 8(49): 86515-86526, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-29156812

RESUMO

Schizophrenia is a complex, severe, chronic psychiatric disorder, and the associated deficit syndrome is widely regarded as an important clinical aspect of schizophrenia. This study analyzed the relationship of deficit syndrome severity with the mRNA levels of members of signaling pathways that associate with the pathophysiology of schizophrenia, including the dopamine D2 receptor (DRD2), protein kinase B (AKT1), and phosphoinositide-3 kinase (PI3KCB), in peripheral blood leukocytes (PBLs) of 20 healthy controls and 19 chronic schizophrenia patients with long-term clozapine treatment. The DRD2 expression levels in chronic schizophrenia group were statistically higher than those in controls (t=2.168, p=0.037). Moreover, in chronic schizophrenia group, correlations were observed between the expression levels of DRD2 and PI3KCB (r=0.771, p<0.001), DRD2 and AKT1 (r=0.592, p=0.008), and PI3KCB and AKT1 (r=0.562, p=0.012) and between the DRD2 mRNA levels and the Proxy for the Deficit Syndrome score (r=0.511, p=0.025). In control group, the correlation between PI3KCB expression levels and DRD2 expression levels was only observed (r=0.782, p<0.001). In conclusion, a correlation was observed between increased deficit syndrome severity and elevated expression levels of DRD2 in PBLs of chronic schizophrenia patients receiving long-term clozapine treatment.

17.
J Econ Entomol ; 110(6): 2371-2380, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29045637

RESUMO

Bradysia odoriphaga Yang et Zhang, the Chinese chive root maggot, is a devastating pest of agricultural plants causing significant losses in vegetable crops, edible mushrooms, and humus. To determine the effects of feeding on different host plants and diets on the life parameters of B. odoriphaga and its tolerance to stressful conditions, we analyzed the life-table data of B. odoriphaga reared on Chinese chive (Allium hookeri), Welsh onion (Allium fistulosum), garlic (Allium sativum), oyster mushroom (Pleurotus ostreatus), and humus and assayed its tolerance to heat and insecticides. Furthermore, we assayed the physiological responses of B. odoriphaga reared on different hosts. Development from egg to adult was successfully completed on five hosts. Life table indicated that when reared on Chinese chive and oyster mushroom, B. odoriphaga showed better life parameters (shorter development time, higher survival rate, and fecundity) than on humus and garlic. However, B. odoriphaga larvae fed on humus and garlic better tolerated heat and insecticides than those that were fed Chinese chive and oyster mushroom; larvae survived longer at 38 and 40°C heat shock and at higher insecticide doses. Activities of antioxidant and detoxification enzymes varied significantly in larvae fed on different hosts. Catalase, superoxide dismutase, glutathione S-transferase, and carboxylesterase activities were higher in larva reared on garlic and humus than on Chinese chive and oyster mushroom. These findings indicated that B. odoriphaga preferred liliaceous vegetables and mushroom, and their tolerance against stress increased when reared on humus and garlic. Such basic information can promote targeted pest management in different agricultural fields and allow better understanding of the acclimatization strategy of B. odoriphaga.


Assuntos
Dieta , Dípteros/fisiologia , Resistência a Inseticidas , Termotolerância , Animais , Dípteros/crescimento & desenvolvimento , Feminino , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Óvulo/fisiologia , Pupa/crescimento & desenvolvimento
18.
Anal Biochem ; 539: 60-69, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-28987934

RESUMO

State functions (e.g., ΔG) are path independent and quantitatively describe the equilibrium states of a thermodynamic system. Isothermal chemical denaturation (ICD) is often used to extrapolate state function parameters for protein unfolding in native buffer conditions. The approach is prudent when the unfolding/refolding processes are path independent and reversible, but may lead to erroneous results if the processes are not reversible. The reversibility was demonstrated in several early studies for smaller proteins, but was assumed in some reports for large proteins with complex structures. In this work, the unfolding/refolding of several proteins were systematically studied using an automated ICD instrument. It is shown that: (i) the apparent unfolding mechanism and conformational stability of large proteins can be denaturant-dependent, (ii) equilibration times for large proteins are non-trivial and may introduce significant error into calculations of ΔG, (iii) fluorescence emission spectroscopy may not correspond to other methods, such as circular dichroism, when used to measure protein unfolding, and (iv) irreversible unfolding and hysteresis can occur in the absence of aggregation. These results suggest that thorough confirmation of the state functions by, for example, performing refolding experiments or using additional denaturants, is needed when quantitatively studying the thermodynamics of protein unfolding using ICD.


Assuntos
Proteínas/química , Espectrometria de Fluorescência , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Bovinos , Guanidina/química , Desnaturação Proteica , Redobramento de Proteína , Proteínas/metabolismo , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Termodinâmica , Ureia/química
19.
J Leukoc Biol ; 102(6): 1333-1345, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28986385

RESUMO

Fibrosis, which can be defined as an abnormal or excessive accumulation of extracellular matrix (ECM), particularly fibrillar collagens, is a key driver of progressive organ dysfunction in many inflammatory and metabolic diseases, including idiopathic pulmonary fibrosis (IPF), cirrhosis, nephropathy, and oral submucous fibrosis (OSF). It has been estimated to contribute to ∼45% of deaths in the developed world. Therefore, agents that target specific fibrotic pathways, with the consequence of slowing, arresting, or even reversing the progression of tissue fibrogenesis, are urgently needed. 7-Bromo-6-chloro-3-[3-(3-hydroxy-2-piperidinyl)-2-oxopropyl]-4(3H)-quinazolinone (halofuginone), an analog of febrifugine, which specifically targets the pathogenesis of ECM proteins, inhibits tissue fibrosis and regeneration and even affects the development of tumors in various tissues. Four modes of actions of halofuginone against fibrosis have been presented: 1) Inhibition of mothers against decapentaplegic homolog 3 (Smad3) phosphorylation downstream of the TGF-ß signaling pathway, 2) reduction of collagen amounts, 3) decreases in ECM protein, and 4) selective prevention of Th17 cell differentiation. In this review, we will mainly focus on the rationale for halofuginone against fibrosis.


Assuntos
Piperidinas/uso terapêutico , Quinazolinonas/uso terapêutico , Animais , Colágeno/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Fibrose , Humanos , Modelos Biológicos , Piperidinas/química , Piperidinas/farmacologia , Quinazolinonas/química , Quinazolinonas/farmacologia , Células Th17/imunologia
20.
Sci Rep ; 7(1): 13381, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-29042590

RESUMO

Bradysia odoriphaga and Bradysia difformis are devastating pests of vegetable, ornamental crops and edible mushrooms causing significant losses. Temperature may be an important factor restricting their population abundance in the summer. To determine the effects of short-term heat shock on adults, their survival, longevity and fecundity data were collected, and antioxidant responses and heat shock protein expression levels were examined. Our results indicated that the survival rates of Bradysia adults decreased rapidly after heat shock ≥36 °C, and the longevity and reproductive capacities were significantly inhibited, indicating that short-term heat shock had lethal and sub-lethal effects. Moreover, the lipid peroxidation levels of B. difformis and B. odoriphaga increased dramatically at 36 °C and 38 °C, respectively. Four antioxidant enzymes activities of B. odoriphaga were greater than those of B. difformis at 38 °C. Additionally, hsp70 and hsp90 expression levels significantly increased after heat stress, and higher expression levels of B. difformis and B. odoriphaga were discovered at 36 and 38 °C respectively, indicating their different heat tolerance levels. Overall, short-term heat shock (≥36 °C) caused significantly adverse effects on Bradysia adults, indicating that it could be applied in pest control, and antioxidant system and hsp genes played important roles in their heat tolerance levels.

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