Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 155
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Org Lett ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32037834

RESUMO

A photoredox catalyst free, visible-light-induced aerobic oxidative [2 + 3] cycloaddition reaction between glycine derivatives and styrene oxides has been disclosed that provides an efficient approach for the rapid synthesis of 1,3-oxazolidines under mild conditions. This photoinduced process is enabled by the formation of an electron donor-acceptor complex between glycine derivatives and benzyl iodides.

2.
J Biomol Struct Dyn ; : 1-14, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32056499

RESUMO

Laccases are multi-copper oxidases (MCOs) that catalyze the oxidation of various organic and inorganic compounds with concomitant reduction of dioxygen to water, and are considered to be green catalysts. Previous studies revealed that in MCOs, the structure of substrate-binding pocket was closely related to the substrate specificity. The amino acids on the pocket-constructing loops were involved in the identification of substrate and affected the catalytic properties of the enzyme. In the Thermus thermophilus SG0.5JP17-16 laccase (lacTT), the Lys428 residue is on pocket-constructing loops, to explore the role of the K428 residue and obtain mutants with enhanced catalytic activity, it was mutated to leucine, glutamic acid, arginine and methionine by site-directed mutagenesis. Structural data revealed that the K428 residue identified the conformation of the substrate by the steric hindrance and interactions with the substrate. Kinetic data indicated that the replacement of K428 by methionine resulted in a mutant with enhanced catalytic activity. The K428M mutant could decolorize the synthetic dyes more efficiently than the wild type enzyme. Altogether, this study provided a strategy to find the mutant with the enhanced catalytic activity.

3.
Artigo em Inglês | MEDLINE | ID: mdl-32067135

RESUMO

The laccase has the ability to oxidize substituted phenols and the water is the sole byproduct, thus it has been employed to remove and/or modify the lignin in lignocellulosic material. A putative laccase gene, LacSM, from Sordaria macrospora k-hell was screened by a genome mining approach. Then, it was cloned and highly expressed in Escherichia coli. The molecular weight of recombinant LacSM was ~ 67 kDa. The optimal pH values for the LacSM oxidation of guaiacol, syringaldazine, 2,6-dimethoxyphenol, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were 6, 7, 5, and 5, respectively. The optimal activity of laccase was observed at 60, 55, 55, and 50 °C for four respective substrates. LacSM remained stable at pH 5-8 and thermostable at 60 °C with guaiacol as the substrate. 1 mM K+, Na+, or Mn2+ ions slightly stimulated laccase activity. In addition, LacSM was moderately tolerant to the Cl- ion and showed an ability to remove and/or modify lignin. Thus, LacSM was a potential candidate for industrial applications, such as lignin degradation of lignocellulosic biomass.

4.
Toxicol Lett ; 322: 66-76, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31945382

RESUMO

Silent Information Regulator 1 (SIRT1), an NAD+-dependent deacetylase, contributes to the neuroprotective effect. However, intracellular signaling pathways that affect SIRT1 function remain unknown. It is well known that N-methyl-D-aspartate (NMDA) receptor activation induces calcium influx which then activates PKC, and SIRT1 is a mRNA target for HuR protein. We hypothesize that Ca2+-PKC-HuR-SIRT1 pathway modulates SIRT1 function. The present study is to investigate the potential pathway of SIRT1 in the SH-SY5Y cell line as an in vitro model of NMDA-induced neurotoxicity. The results showed that: (1) SIRT1 levels were downregulated in NMDA model; (2) NMDA induced an increase in serine phosphorylation of HuR, while inhibition of serine phosphorylation of HuR increased SIRT1 levels, promoting cell survival; (3) PKC inhibitor (Gö 6976) reversed NMDA insults and also suppressed serine phosphorylation of HuR; (4) 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM), an intracellular calcium chelator, fully reversed NMDA insults and also inhibited PKC activity evoked by NMDA. These results indicate that intracellular elevated Ca2+ activates PKC, which phosphorylates HuR and then promotes SIRT1 mRNA decay and subsequent neuronal death in NMDA model. Therefore, the study suggests that inhibition of Ca2+-PKC-HuR-SIRT1 pathway could be an effective strategy for preventing certain neurological diseases related to NMDA excitotoxicity.


Assuntos
Agonistas de Aminoácidos Excitatórios/toxicidade , N-Metilaspartato/toxicidade , Neurônios/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Sirtuína 1/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação para Baixo , Proteína Semelhante a ELAV 1/metabolismo , Humanos , Neurônios/enzimologia , Neurônios/patologia , Síndromes Neurotóxicas/enzimologia , Síndromes Neurotóxicas/patologia , Fosforilação , Proteína Quinase C/metabolismo , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Serina , Sirtuína 1/genética
5.
Am J Epidemiol ; 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31899792

RESUMO

Previous findings concerning gastric atrophy as a potential risk factor for esophageal squamous cell carcinoma (ESCC) have been inconsistent. Our aim was to test whether gastric atrophy, and further its interaction with poor oral health, elevate the risk for ESCC in a high-risk region of China. Our population-based case-control study in Taixing, China from 2010-2014, recruited cases from local hospitals and the local cancer registry. Controls were selected randomly from the local population registry. Ultimately, 1210 cases and 1978 controls answered questionnaire and provided blood samples for assay of pepsinogens. Unconditional logistic regression models were utilized to estimate odds ratios (ORs) and 95% confidence intervals (CI). Gastric atrophy (defined as a serum level of pepsinogen I <55 µg/L) was associated with an increased risk for ESCC (OR 1.61; 95%CI 1.33-1.96), even after full adjustment for potential confounding factors. In addition, suggestion of an additive interaction between gastric atrophy and poor oral health was observed (relative excess risk due to interaction 1.28, 95% CI 0.39-2.18). We conclude that gastric atrophy appears to be a risk factor for ESCC in a high-risk region of China and there is a suggested additive interaction with poor oral health that increases this risk even further.

6.
Chemosphere ; 238: 124602, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545211

RESUMO

Polybrominated diphenyl ethers (PBDEs) have been known to exhibit neurotoxicity in rats; however, the underlying mechanism remains unknown and there is no available intervention. In this study, we aimed to investigate the role of oxidative and nitrosative stress in the neurotoxicity in the cerebral cortex and primary neurons in rats following the BDE-153 treatment. Compared to the untreated group, BDE-153 treatment significantly induced the neurotoxic effects in rats, as manifested by the increased lactate dehydrogenase (LDH) activities and cell apoptosis rates, and the decreased neurotrophic factor contents and cholinergic enzyme activities in rats' cerebral cortices and primary neurons. When compared to the untreated group, the oxidative and nitrosative stress had occurred in the cerebral cortex or primary neurons in rats following the BDE-153 treatment, as manifested by the increments in levels of reactive oxygenspecies (ROS), malondialdehyde (MDA), nitric oxide (NO), and neuronal nitric oxide synthase (nNOS) mRNA and protein expressions, along with the decline in levels of superoxide dismutase (SOD) activity, glutathione (GSH) content, and peroxiredoxin I (Prx I) and Prx II mRNA and protein expressions. In addition, the ROS scavenger N-acetyl-l-cysteine (NAC) or NO scavenger NG-Nitro-l-arginine (L-NNA) significantly rescued the LDH leakage and cell survival, reversed the neurotrophin contents and cholinergic enzymes, mainly via regaining balance between oxidation/nitrosation and antioxidation. Overall, our findings suggested that oxidative and nitrosative stresses are involved in the neurotoxicity induced by BDE-153, and that the antioxidation is a potential targeted intervention.


Assuntos
Córtex Cerebral/patologia , Éteres Difenil Halogenados/toxicidade , Síndromes Neurotóxicas/patologia , Estresse Nitrosativo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Bifenil Polibromatos/toxicidade , Acetilcisteína/farmacologia , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Glutationa/metabolismo , Éteres Difenil Halogenados/metabolismo , Masculino , Malondialdeído/metabolismo , Fatores de Crescimento Neural/metabolismo , Neurônios/efeitos dos fármacos , Neurotrofina 3/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Estresse Nitrosativo/fisiologia , Estresse Oxidativo/fisiologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
7.
Emerg Infect Dis ; 25(12): 2274-2277, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31742514

RESUMO

During 2013-2017, a total of 211 cases of listeriosis were reported by 64 sentinel hospitals in China to a national foodborne disease surveillance network. The average case-fatality rate was 31.2% for perinatal cases and 16.4% for nonperinatal cases. Sequence types 87 and 8 were the most prevalent types.

8.
Med Sci Monit ; 25: 9042-9047, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31777403

RESUMO

BACKGROUND The study aimed to investigate the expression of brain natriuretic peptide (BNP) and natriuretic peptide receptor A (NPR-A) in L6-S1 dorsal root ganglia (DRG) in a rat model of chronic nonbacterial prostatitis (CNP). MATERIAL AND METHODS One hundred specific pathogen-free (SPF) male Sprague-Dawley rats were randomly divided into a control group (N=50) and a study group (N=50). The control group underwent prostatic injection of 0.1 ml of normal saline on days 3, 7, 10, 14, and 28. The study group, or rat model of CNP, underwent prostatic injection of 0.1 ml of complete Freund's adjuvant on days 3, 7, 10, 14, and 28. At the end of the study, the rats were euthanized, and the prostate tissues and L6-S1 DRG were removed. Histology was performed on the prostate tissue from the rats in the study group and control group. Real-time fluorescence-based quantitative polymerase chain reaction (PCR) and Western blot were used to study the expression of BNP and NPR-A mRNA and protein in the DRG from the rats in the study group and control group. RESULTS In the rat model of CNP, the expression of BNP and NPR-A were significantly increased in L6-S1 DRG compared with the controls. CONCLUSIONS In a rat model of CNP, the increased expression of BNP and NPR-A in L6-S1 DRG may have a role in pain signaling pathways associated with chronic prostatitis.

9.
Cancer Epidemiol Biomarkers Prev ; 28(12): 2014-2021, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31562207

RESUMO

BACKGROUND: To explore the relationship between family history of esophageal cancer, SNPs, and the risk of esophageal squamous cell carcinoma (ESCC), we performed a population-based case-control study and developed a genetic family history-related risk (GFR) score and non-family history-related risk (GnFR) score to quantify the cumulative number of risk genotypes carried by each individual. METHODS: We used data of 700 patients with nonfamilial ESCC, 341 patients with familial ESCC, 1,445 controls without a family history of esophageal cancer, and 319 controls with a family history. We genotyped 87 genetic variants associated with the risk for ESCC, and constructed GFR and GnFR scores for cases and controls. RESULTS: Our results show that ESCC risk increased with higher GFR score (P trend = 0.0096). Among the familial subgroup, we observed a nearly 7-fold [95% confidence interval (CI), 1.92-24.77] higher risk of ESCC in the highest GFR score group. The corresponding estimate was only 2-fold (95% CI, 1.41-3.93) higher risk of ESCC, in the stratum without a reported family history of esophageal cancer. Certain cell signaling pathways and immune-related pathways were enriched, specifically in familial ESCC. Results from a reconstructed cohort analysis demonstrated that cumulative risk to get esophageal cancer by age 75 years was 13.3%, 10.2%, 8.2%, and 5.1%, respectively, in four subgroups as defined by first-degree relatives of cases or controls with high or low genetic risk score. In particular, the cohort of relatives of ESCC cases with low genetic risk score exhibit a higher cumulative risk than the cohort of relatives of controls with high genetic risk score. It demonstrates that environmental factors play a major role in esophageal cancer. CONCLUSIONS: Further studies are warranted to dissect the mechanisms of shared environmental and genetic susceptibility affecting the risk of getting ESCC. IMPACT: Our study highlights that the need of preventive strategies to screen certain genetic polymorphisms, especially in individuals whose relatives had ESCC.

10.
ACS Omega ; 4(2): 3933-3945, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-31459602

RESUMO

Herein, we report a novel type of smart graphene oxide nanocomposites (MGO@PNB) with excellent magnetism and high thermosensitive ion-recognition selectivity of lead ions (Pb2+). The MGO@PNB are fabricated by immobilizing superparamagnetic Fe3O4 nanoparticles (NPs) and poly(N-isopropylacrylamide-co-benzo-18-crown-6 acrylamide) thermosensitive microgels (PNB) onto graphene oxide (GO) nanosheets using a simple one-step solvothermal method and mussel-inspired polydopamine chemistry. The PNB are composed of cross-linked poly(N-isopropylacrylamide) (PNIPAM) chains with numerous appended 18-crown-6 units. The 18-crown-6 units serve as hosts that can selectively recognize and capture Pb2+ from aqueous solution, and the PNIPAM chains act as a microenvironmental actuator for the inclusion constants of 18-crown-6/Pb2+ host-guest complexes. The loaded Fe3O4 NPs endow the MGO@PNB with convenient magnetic separability. The fabricated MGO@PNB demonstrate remarkably high ion-recognition selectivity of Pb2+ among the coexisting metal ions because of the formation of stable 18-crown-6/Pb2+ inclusion complexes. Most interestingly, the MGO@PNB show excellent thermosensitive adsorption ability toward Pb2+ due to the incorporation of PNIPAM functional chains on the GO. Further thermodynamic studies indicate that the adsorption of Pb2+ onto the MGO@PNB is a spontaneous and endothermic process. The adsorption kinetics and isotherm data can be well described by the pseudo-second-order kinetic model and the Langmuir isotherm model, respectively. Most importantly, the Pb2+-loaded MGO@PNB can be more easily regenerated by alternatively washing with hot/cold water than the commonly used regeneration methods. Such multifunctional graphene oxide nanocomposites could be used for specific recognition and removal of Pb2+ from water environment.

11.
Biochemistry ; 58(36): 3735-3743, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31424194

RESUMO

The conserved structural motif D is an important determinant of the speed and fidelity of viral RNA-dependent RNA polymerases (RdRps). Structural and computational studies have suggested that conformational changes in the motif-D loop that help to reposition the catalytic lysine represent critical steps in nucleotide selection and incorporation. Conformations of the motif-D loop in the poliovirus RdRp are likely controlled in part by noncovalent interactions involving the motif-D residue Glu364. This residue swivels between making interactions with Lys228 and Asn370 to stabilize the open and closed loop conformations, respectively. We show here that we can rationally control the motif-D loop conformation by breaking these interactions. The K228A variant favors a more active closed conformation, leading to increased nucleotide incorporation rates and decreased nucleotide selectivity, and the N370A variant favors a less active open conformation, leading to decreased nucleotide incorporation rates and increased nucleotide selectivity. Similar competing interactions likely control nucleotide incorporation rates and fidelity in other viral RdRps. Rational engineering of these interactions may be important in the generation of live, attenuated vaccine strains, considering the established relationships between RdRp function and viral pathogenesis.

12.
Cancer Med ; 8(12): 5769-5778, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31369212

RESUMO

The relationship between risk of esophageal squamous cell carcinoma (ESCC) and adult height, changes in individual body mass index (BMI) and body shape is not established. We performed a large population-based case-control study, which enrolled a total of 1414 ESCC cases and 1989 controls in a high-incidence area in China. Using face-to-face interview with a structured questionnaire, information on participants' heights, weights, and perceived body shapes at 20 years of age was collected. Additionally, data on weight and perceived body shape among the same participants 10 years prior to ascertainment were collected using the same method. Odd ratios (ORs) of ESCC risk in relation to BMI and body shape were estimated using unconditional logistic regression models. The adjusted results indicated that ESCC risk in adults rapidly rose as height increased, plateauing at 170 cm among men and 157 cm among women. Among participants who were underweight, normal weight, or thinner than body shape 4, body weight loss was associated with increased risk of ESCC, and body weight gain was associated with decreased incidence of ESCC (ORs ranging from 0.40 to 0.76). Notably, however, changes in body weight did not significantly affect ESCC risk among participants who were overweight, obese, or larger than body shape 3. Maintaining a fit body shape and a reasonable BMI is advisable and of vital importance to reduce the risk of ESCC, especially in high-risk areas.

14.
Medicine (Baltimore) ; 98(27): e16309, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31277173

RESUMO

OBJECTIVE: To compare the prognosis of papillary and clear cell renal cell carcinoma (RCC) in order to determine the optimal follow-up and therapy for patients with RCC. METHODS: A systematic search of Web of Science, EMBASE, Cochrane Library, and PubMed databases was conducted for articles published through July 30, 2018, reporting on a comparison of the prognosis of papillary RCC and clear cell RCC using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. RESULTS: Of 1896 studies, 11 were considered for the evidence synthesis. A total of 35,832 patients were included. Of these patients, 6907 patients were diagnosed with papillary renal cell carcinoma, and 28,925 patients were diagnosed with clear cell renal cell carcinoma. The prognosis of papillary RCC was better than that of clear cell RCC (hazard ratio (HR) = 0.50; 95% confidence interval (CI) 0.45 to 0.56; P < .001; I = 91.9%). A subgroup analysis indicated that papillary RCC was associated with better outcomes (HR = 0.76, 95% CI 0.50-1.16), and a trend toward a higher risk of mortality was observed in patients with metastatic RCC presenting with papillary histology, but the difference was not statistically significant (HR = 1.12, 95% CI 0.71-1.76, P = .085). Pooled data suggested a lack of a significant difference between papillary RCC (p-RCC) type 1 and clear cell RCC (cc-RCC) (HR = 0.30, 95% CI 0.12-0.73, P = .085). The pooled HR for the prognosis of p-RCC type 2 compared to cc-RCC was 1.69 (95% CI 0.93-3.08; P = .032). CONCLUSION: Papillary RCC is associated with better outcomes than clear cell RCC in patients without metastases, but not in patients with metastases. Optimal follow-up or therapy for patients with RCC should be assigned according to the tumor stage and subtype.


Assuntos
Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Carcinoma de Células Renais/terapia , Humanos , Neoplasias Renais/terapia , Prognóstico
15.
Int J Mol Med ; 44(3): 1006-1014, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31257465

RESUMO

The aim of the present study was to compare the effects of adipose­derived mesenchymal stem cell (ADSC) and bone marrow mesenchymal stem cell (BMSC) transplantation into the corpora cavernosa of diabetic rats with erectile function. ADSCs and BMSCs were isolated and identified by flow cytometry. Rats with streptozocin­induced diabetes were screened using apomorphine to obtain a rat model of diabetic erectile dysfunction, followed by transplantation of ADSCs and BMSCs into the corpora cavernosa. Two weeks later, the rats were again injected with apomorphine, the intracavernous pressure (ICP) and mean arterial pressure (MAP) of the penile tissue were measured, and the corpus cavernosum tissues were harvested. Angiogenic endothelial nitric oxide synthase (eNOS) expression was detected by western blotting and immunofluorescence analysis. The blood vessels in the corpus cavernosum were observed following hematoxylin and eosin (H&E) staining, and the expression of collagen was detected by Sirius Red staining. The cellular ultrastructure was examined by transmission electron microscopy. Intracavernous injection of ADSCs significantly increased ICP and ICP/MAP. Western blotting and immunofluorescence results revealed that ADSC treatment improved the expression of eNOS in the penile tissue of diabetic rats. The H&E staining results demonstrated that ADSC treatment promoted revascularization of the corpus cavernosum, and the results of Sirius Red staining revealed that ADSC treatment reduced penile collagen in diabetic rats. Transmission electron microscopy examination revealed that the ultrastructure of the tissues in the ADSC­treated group was more complete compared with that in the untreated diabetic model group. In conclusion, ADSCs were found to be more effective compared with BMSCs in treating diabetes­related erectile dysfunction.


Assuntos
Tecido Adiposo/citologia , Complicações do Diabetes , Disfunção Erétil/etiologia , Disfunção Erétil/fisiopatologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Biomarcadores , Colágeno/metabolismo , Disfunção Erétil/terapia , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Ereção Peniana , Ratos
16.
Int Urol Nephrol ; 51(9): 1517-1526, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31190295

RESUMO

BACKGROUND: To investigate the role of Minichromosome maintenance protein 5 (MCM5) in the clinical prognosis and biological function of renal cell carcinoma (RCC). METHODS: The Oncomine database was analysed to determine the differential expression of MCMs in RCC. A total of 50 RCC tissues were evaluated by immunohistochemistry (IHC), and the association between MCM5 and clinicopathologic features was determined. Kaplan-Meier curves and the log-rank test were applied for survival analysis. MCM5 expression in RCC tissues and cell lines was examined further by Western blotting. To explore the biological function of MCM5 in RCC, RCC cell lines (786-0, 769p) were transfected with shRNA-MCM5 or MCM5. Cell proliferation was assessed using MTT and colony-formation assays. Tumour xenografts were generated in nude mice to confirm the effects of MCM5 on tumour growth. RESULTS: MCM5 was significantly overexpressed in RCC tissues; this outcome was confirmed by the Oncomine database, IHC and Western blotting. IHC and LinkedOmics analysis demonstrated that the MCM5 expression was significantly associated with pathological stage, lymph node status, distant metastasis, and TNM stage (p < 0.05) but not with sex, age, position, or tumour size (p > 0.05). Furthermore, high MCM5 levels correlated with unfavourable clinical outcomes in RCC (p < 0.05). Additionally, MCM5 silencing inhibited RCC cell line proliferation and reduced 786-0 xenograft tumour growth; in contrast, MCM5 upregulation promoted cell proliferation. CONCLUSION: MCM5 overexpression is associated with malignant status and poor prognosis in RCC. Additionally, MCM5 plays an important role in proliferation and may be a potential prognostic marker and novel therapeutic target for RCC.

18.
Toxicol Lett ; 311: 37-48, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31029751

RESUMO

Polybrominated diphenyl ether-153 (BDE-153) has been demonstrated to induce neuronal apoptosis in rat cerebral cortex and primary neurons, however, the roles of mitochondria and endoplasmic reticulum (ER) remain unclear in the BDE-153-induced neuronal apoptosis. To this purpose, we observed the mitochondria and ER ultrastructure changes in the neuronal apoptosis in rats following BDE-153 treatment, detected the mitochondrial membrane potential (MMP), Ca2+-Mg2+-ATP enzyme activity, and the changes of mitochondria and ER apoptosis related molecules in rat cerebral cortex and in primary neurons following BDE-153 treatment. Results showed that compared to the control group, neuronal apoptosis was significantly increased in a dose-dependent manner in rat cerebral cortex and in primary neurons following BDE-153 treatment. In comparison with control, BDE-153 treatment induced remarkable ultrastructural changes in ER rather than in mitochondria, and the severity of ER damage was worse with the increasing BDE-153 dose. Meanwhile, ER apoptosis related molecules including caspase-12 (at mRNA level), cleaved caspase-12 (at protein level), and Tmem132a (at mRNA and protein levels) were significantly increased in the cerebral cortex in rats following BDE-153 treatment, while procaspase-12 protein was significantly decreased, comparing with control. In contrast, mitochondria apoptosis related molecules (MMP, Ca2+-Mg2+-ATP enzyme activity, cyt-C protein, caspase-3, 8, 9 mRNA, caspase-8, 9 enzyme activities) did not significantly changed in the cerebral cortex of rats or in primary neurons following BDE-153 treatment, except for the elevated caspase-3 mRNA and enzyme activity. Therefore, we conclude that BDE-153 induced neuronal apoptosis was dependent on p53, and mediated more by ER than mitochondria in the cerebral cortex of rats and in primary neurons. The findings suggest that ER is a potential sensitive target of BDE-153 neurotoxicity, providing a scientific evidence for the mechanism and intervention study on PBDE's neurotoxicity.


Assuntos
Apoptose/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Degeneração Neural , Neurônios/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Bifenil Polibromatos/toxicidade , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Células Cultivadas , Córtex Cerebral/metabolismo , Córtex Cerebral/ultraestrutura , Relação Dose-Resposta a Droga , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Neurônios/metabolismo , Neurônios/ultraestrutura , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Ratos Sprague-Dawley , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
19.
FEBS Open Bio ; 9(5): 986-995, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30964606

RESUMO

Laccase is a multi-copper oxidase which oxidizes substrate at the type 1 copper site, simultaneously coupling the reduction of dioxygen to water at the trinuclear copper center. In this study, we used site-directed mutagenesis to study the effect of axial bonds between the metal and amino acid residue side chains in lacTT. Our kinetic and spectral data showed that the replacement of the axial residue with non-coordinating residues resulted in higher efficiency (kcat /Km ) and a lower Cu2+ population at the type 1 copper site, while substitution with strongly coordinating residues resulted in lower efficiency and a higher Cu2+ population, as compared with the wild-type. The redox potentials of mutants with hydrophobic axial residues (Ala and Phe) were higher than that of the wild-type. In conclusion, these insights into the catalytic mechanism of laccase may be of use in protein engineering to fine-tune its enzymatic properties for industrial application.


Assuntos
Proteínas de Bactérias/química , Lacase/química , Thermus thermophilus/enzimologia , Proteínas de Bactérias/metabolismo , Catálise , Cinética , Lacase/metabolismo , Conformação Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica
20.
Oncol Lett ; 17(3): 3173-3180, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30867747

RESUMO

Long non-coding RNAs (lncRNAs) have been demonstrated to serve vital roles in renal cell carcinoma (RCC) development. Gastric carcinoma high expressed transcript 1 (GHET1) regulates numerous biological processes in cancer cells. However, the biological role of GHET1 in RCC has not yet been identified. This study aimed to investigate the role of GHET1 in RCC. In the present study, the expression of GHET1 in RCC tissues and the 786-O, A498 and 293 cell lines was assessed by reverse transcription-quantitative polymerase chain reaction. Cell Counting Kit-8, colony formation and cell scratch assays were used to determine the effects of GHET1 on tumorigenesis. Western blotting was performed to examine the effect of GHET1 on epithelial-mesenchymal transition (EMT) in RCC cells. GHET1 expression was significantly increased in the RCC samples in comparison with adjacent tissues. High expression levels of GHET1 were associated with distant metastasis and clinical stage severity, thus, high GHET1 expression may serve as a predictor for a poor prognosis. In addition, RCC cells presented higher GHET1 mRNA and protein expression levels compared with in 293 cells. Furthermore, silencing GHET1 suppressed cell growth, weakened cell migration and inhibited EMT of RCC cells in vitro. In conclusion, the present study suggested that GHET1 may be considered a therapeutic target for the treatment or prevention of RCC.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA