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1.
J Cancer Res Clin Oncol ; 149(17): 15573-15588, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37648810

RESUMO

OBJECTIVE: Although the use of osimertinib can significantly improve the survival time of lung adenocarcinoma (LUAD) patients with epithelial growth factor receptor mutation, eventually drug resistance will limit the survival benefit of most patients. This study aimed to develop a novel prognostic predictive signature based on genes associated with osimertinib resistance. METHODS: The differentially expressed genes (DEGs) associated with osimertinib resistance in LUAD were screened from Gene Expression Omnibus datasets and The Cancer Genome Atlas datasets. Multivariate cox regression was used to establish a prognostic signature, and then a nomogram was developed to predict the survival probability of LUAD patients. We used ROC curve and DCA curve to evaluate its clinical prediction accuracy and net benefit. In addition, the differentially expressed genes significantly associated with prognosis were selected for immune infiltration analysis and drug sensitivity analysis, and their roles in the progression of lung adenocarcinoma were verified by in vitro experiments. RESULTS: Our evaluation results indicated that the new nomogram had higher clinical prediction accuracy and net benefit value than the TN nomogram. Further analysis showed that patients with low STRIP2 expression had a higher level of immune response, and may be more likely to benefit from immune checkpoint inhibitors and conventional antitumor drugs. This may help to select more precise and appropriate therapy for LUAD patients with osimertinib resistance. Furthermore, in vitro experiments showed that STRIP2 promoted the LUAD cells proliferation, migration and invasion. This further demonstrates the importance of this gene signature for prognostic prediction. CONCLUSION: We developed a reliable prognostic model based on DEGs associated with osimertinib resistance and screened for biomarker that can predict the immune response in LUAD patients, which may help in the selection of treatment regimens after osimertinib resistance.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Prognóstico , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Acrilamidas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética
2.
Transl Cancer Res ; 11(6): 1472-1482, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35836506

RESUMO

Background: Bevacizumab (Avastin®), a monoclonal antibody targeting vascular endothelial growth factor (VEGF)-A, is widely used in treating a variety of malignant tumors. Several biosimilars of bevacizumab have been developed and marketed with the expiration of bevacizumab's patent. The objective of this study was to collate available data from head-to-head randomized controlled trials (RCTs) and evaluate the efficacy and safety of biosimilar bevacizumab compared with the bevacizumab (Avastin®) in patients with non-squamous non-small cell lung cancer (NSCLC). Methods: Literature search of Web of Science, PubMed, Cochrane Library, EMBASE, and ClinicalTrials.gov was performed from inception until October 15, 2021. The efficacy outcome indicators were objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). The occurrence of adverse events (AEs) was evaluated for safety outcome. Results: Ten RCTs recruiting 6,416 patients with non-squamous NSCLC were included. All RCTs studies included the biosimilar bevacizumab group as the experimental group and the original bevacizumab group as the control group. The patients in the experimental group and control group received the same dose and duration of chemotherapy combined with carboplatin and paclitaxel. The results of meta-analysis showed that there were no significant differences in ORR [risk ratio (RR): 0.97, 95% confidence interval (95% CI): 0.93-1.02. P=0.841, I2=0], PFS (RR: 1.04, 95% CI: 0.98-1.10, P=0.235, I2=0) and OS (RR: 1.05, 95% CI: 1.00-1.10, P=0.692, I2=0) between the biomarker and original groups. The P values of ORR, PFS and OS were 0.533, 0.970 and 0.916 respectively as shown by Egger's test, suggesting that there was no publication bias. Subgroup analysis showed no significant differences in ORR, PFS, and OS between the Chinese and multicenter trials. The pooled incidence rate of AEs between two groups was similar, and there was also no significant difference between the two groups. Discussion: This is the first study to independently report biosimilar bevacizumab in a meta-analysis on NSCLC treatment. The results showed that biosimilar bevacizumab had similar efficacy and safety compared with the original bevacizumab. Trial Registration: PROSPERO registration No. CRD42021276991.

3.
BMC Anesthesiol ; 22(1): 190, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725376

RESUMO

BACKGROUND: Self-efficacy, as the vital determinant of behavior, influencing clinicians' situation awareness, work performance, and medical decision-making, might affect the incidence of anesthesia-related adverse events (ARAEs). This study was employed to evaluate the association between perceived self-efficacy level and ARAEs. METHODS: A cross-sectional study was performed in the form of an online self-completion questionnaire-based survey. Self-efficacy was evaluated via validated 4-point Likert scales. Internal reliability and validity of both scales were also estimated via Cronbach's alpha and validity analysis. According to the total self-efficacy score, respondents were divided into two groups: normal level group and high level group. Propensity score matching and multivariable logistic regression were employed to identify the relationship between self-efficacy level and ARAEs. RESULTS: The response rate of this study was 34%. Of the 1011 qualified respondents, 38% were women. The mean (SD) age was 35.30 (8.19) years. The Cronbach's alpha of self-efficacy was 0.92. The KMO (KMO and Bartlett's test) value of the scale was 0.92. ARAEs occurred in 178 (33.0%) of normal level self-efficacy group and 118 (25.0%) of high level self-efficacy group. Before adjustment, high level self-efficacy was associated with a decreased incidence of ARAEs (RR [relative risk], 0.76; 95% CI [confidence interval], 0.62-0.92). After adjustment, high level self-efficacy was also associated with a decreased incidence of ARAEs (aRR [adjusted relative risk], 0.63, 95% CI, 0.51-0.77). In multivariable logistic regression, when other covariates including years of experience, drinking, and the hospital ranking were controlled, self-efficacy level (OR [odds ratio], 0.62; 95% CI, 0.46-0.82; P = 0.001) was significantly correlated with ARAEs. CONCLUSIONS: Our results found a clinically meaningful and statistically significant correlation between self-efficacy and ARAEs. These findings partly support medical educators and governors in enhancing self-efficacy construction in clinical practice and training.


Assuntos
Anestesia , Anestesiologistas , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Autoeficácia , Inquéritos e Questionários
4.
Front Oncol ; 12: 862337, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35402261

RESUMO

Gastric cancer (GC) is a kind of malignant tumor disease that poses a serious threat to human health. The GC immune microenvironment (TIME) is a very complex tumor microenvironment, mainly composed of infiltrating immune cells, extracellular matrix, tumor-associated fibroblasts, cytokines and chemokines, all of which play a key role in inhibiting or promoting tumor development and affecting tumor prognosis. Long non-coding RNA (lncRNA) is a non-coding RNA with a transcript length is more than 200 nucleotides. LncRNAs are expressed in various infiltrating immune cells in TIME and are involved in innate and adaptive immune regulation, which is closely related to immune escape, migration and invasion of tumor cells. LncRNA-targeted therapeutic effect prediction for GC immunotherapy provides a new approach for clinical research on the disease.

6.
Front Neurosci ; 13: 636, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31297044

RESUMO

Isoflurane (ISO) post-conditioning attenuates cerebral ischemia/reperfusion (I/R) injury, but the underlying mechanism is incompletely elucidated. Transforming growth factor beta (TGF-ß) and hedgehog (Hh) signaling pathways govern a wide range of mechanisms in the central nervous system. We aimed to investigate the effect of the TGF-ß2/Smad3 and sonic hedgehog (Shh)/Glioblastoma (Gli) signaling pathway and their crosstalk in the hippocampus of rats with ISO post-conditioning after cerebral I/R injury. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), 1.5 h occlusion and 24 h reperfusion (MCAO/R). To assess the effect of ISO after I/R injury, various approaches were used, including neurobehavioral tests, TTC staining, HE staining, Nissl staining, TUNEL staining, immunofluorescence (IF), qRT-PCR (quantitative real-time polymerase chain reaction) and Western blot. The ISO post-conditioning group (ISO group) received 1 h ISO post-conditioning when reperfusion was initiated, leading to lower infarct volumes and neurologic deficit scores, more surviving neurons, and less damaged and apoptotic neurons. IF staining, qRT-PCR and Western blot showed high expression levels of TGF-ß2, Shh and Gli1 in the hippocampal CA1 of the ISO group. Phosphorylated Smad3 (p-Smad3), Patched (Ptch), and Smoothed (Smo) were also increased at protein level in the ISO group, whereas total Smad3 expression did not change in all groups. When TGF-ß2 inhibitor, pirfenidone, or Smad3 inhibitor, SIS3 HCl, were administered, the expression levels of p-Smad3 and Gli1 were reduced, and surviving pyramidal neurons decreased. By contrast, the expression levels of TGF-ß2 and p-Smad3 did not change significantly after pre-injection of Smo inhibitor cyclopamine, but reduced the expression levels of Shh, Ptch, and Gli1. Moreover, Gli showed the lowest expression levels with pirfenidone combined with cyclopamine. These findings indicate that the TGF-ß and hedgehog signaling pathways mediate the neuroprotection of ISO post-conditioning after cerebral I/R injury, and crosstalk between two pathways at the Gli1 level.

7.
Behav Brain Res ; 370: 111952, 2019 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-31103751

RESUMO

Existing evidence from clinical and animal experiments all indicated that fluoxetine, selective serotonin-reuptake inhibitor (SSRI) and anti-depressant drug, has neuroprotection and improve functional outcomes after stroke. Endoplasmic reticulum stress (ERS) inducing apoptosis after cerebral ischemia reperfusion injury was demonstrated in our previous work. This trial was examined whether fluoxetine mitigates ERS-induced neuron apoptosis. Male sprague-dawley rats of cerebral ischemia reperfusion injury was produced via middle cerebral artery occlusion (MCAO) strategy, with ischemia for 90 min and reperfusion for 24 h. Experimental groups were divided into sham group, MCAO group, and fluoxetine group. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was used to evaluate cerebral infarct size. The expression of glucose-regulated protein 78 (GRP78), caspase-12, CHOP and caspase-3 were measured by Western blot and immunohistochemistry staining assays. Neurons apoptosis rate in the hippocampus was examined by the TUNEL assay. Neurobehavior examination was used to evaluate the motor function and passive avoidance test was used to assess cognition dysfunction. Fluoxetine treatment reduced the infarct size of rats after cerebral ischemia reperfusion injury. Furthermore, fluoxetine treatment decreased the expression of GRP-78, caspase-12, CHOP and caspase-3, and attenuated neurons apoptosis. Administration of fluoxetine promoted the damaged motor function. In the cognition test, after 4 days of fluoxetine treatment, cognition function of rats was improved. Fluoxetine treatment can mitigate cognition and neurobehavior impairment induced by cerebral ischemia reperfusion injury through inhibiting ERS-mediated neurons apoptosis in the hippocampus.


Assuntos
Cognição/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fluoxetina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Hipocampo/metabolismo , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Neurônios/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Lobo Temporal/metabolismo
8.
RSC Adv ; 9(21): 11614-11620, 2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35517023

RESUMO

To maximize the final lactic acid productivity and concentration, temperature control was optimized using a mathematical modelling approach. A kinetic model, including cell growth, product formation and substrate consumption equations, was proposed to describe the lactic acid production process by Escherichia coli AC-521 with glycerol as the substrate. By constructing four functions, the temperature effect was introduced on the fermentation process, where four parameters (X max, µ max, Y ps and ß) were observed to be significantly affected by the temperature. For the convenience of application, the temperature control strategies were simplified by dividing the whole fermentation process into several units. In each unit, the temperature was controlled constantly. Based on the model, the optimal temperature for each unit was determined to maximize the final lactate productivity. This temperature control strategy can be effectively applied in batch and fed-batch cultures, and the verified experimental evaluation showed a good correlation with the model data. Under improved temperature control conditions, a maximal lactic acid concentration of 90.4 g L-1 was obtained after 80 h of fed-batch fermentation, giving a productivity of 1.13 g L-1 h-1, which is 1.2 times more than that in the conventional constant temperature during the cultivation course.

9.
Biomed Pharmacother ; 110: 420-430, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30530044

RESUMO

AIM: The Wnt/ß-catenin signaling pathway plays an important role in ischemia-reperfusion(I/R) injury, and the transforming growth factor(TGF)-ß/Smad signaling pathway participates in the neuroprotection effect induced by isoflurane(ISO) postconditioning. In this study, we aimed to explore the role of the Wnt/|[beta]|-catenin ß-catenin signaling pathway in the neuroprotection effect induced by ISO postconditioning, and investigate the interaction of Wnt/ß-catenin and TGF-ß/Smad signaling pathway in this neuroprotection effect. METHODS: Cerebral I/R injury was established in Sprague-Dawley rats by using the middle cerebral artery occlusion (MCAO) model for 90 min followed by 24 h reperfusion. Postconditioning by inhalation of ISO was performed for 60 min after ischemia at the onset of reperfusion. Neurological deficit scoring, 2,3,5-triphenyl tetrazolium chloride staining and Nissl staining were adopted to evaluate brain injury. Apoptosis of the hippocampus and cortex neurons was detected by TUNEL staining. The expression levels of Wnt3a, GSK-3ß, ß-catenin, Cyclin D1, VEGF, Caspase 3, TGF-ß1, Smad3 and p-Smad3 were determined by immunofluorescence (IF) staining, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Various targeted inhibitors were administered via intraperitoneal injection or lateral ventricle injection. RESULTS: In the cortex region, the neurological deficit score, infarct volumes and neuron apoptosis increased, and the expression level of the Wnt3a, GSK-3ß, ß-catenin, VEGF and Cyclin D1 decreased in the MCAO group compared with the Sham group. In the MCAO + ISO group, the neurological deficit score, infarct volumes and neuron apoptosis reduced significantly, the expression levels of Wnt3a, ß-catenin, VEGF and Cyclin D1 increased, while the expression level of GSK-3ß and Caspase 3 decreased relative to MCAO group. When Wnt inhibitor(DKK-1) was given in advance followed by ISO postconditioning, the neurological deficit score, infarct volumes, neuron apoptosis and the expression level of GSK-3ß and Caspase 3 increased. qRT-PCR and IF showed similar changes in the protein levels of all groups. However, the expression level of ß-catenin in nuclear and cytoplasm both decreased significantly after pre-injection with the TGF-ß1 inhibitor(LY2157299) and Smad3 inhibitor(SIS3), whereas the expression levels of TGF-ß1, Smad3 and p-Smad3 were almost unchanged. The expression levels of all the related proteins and morphological changes in the hippocampus region were consistent with that of the cortex. CONCLUSION: ISO postconditioning can reduce cerebral I/R injury by activating the Wnt/ß-catenin signaling pathway and may be related to the TGF-ß/Smad3 signaling pathway.


Assuntos
Isquemia Encefálica/metabolismo , Pós-Condicionamento Isquêmico/métodos , Isoflurano/uso terapêutico , Traumatismo por Reperfusão/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Via de Sinalização Wnt/fisiologia , Anestésicos Inalatórios/farmacologia , Anestésicos Inalatórios/uso terapêutico , Animais , Isquemia Encefálica/tratamento farmacológico , Isoflurano/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Via de Sinalização Wnt/efeitos dos fármacos
10.
Biomed Pharmacother ; 108: 1596-1606, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30372862

RESUMO

AIM: Endoplasmic reticulum stress (ERS) is vital in inducing apoptosis via caspase-12 and C/EBP homologous protein (CHOP) apoptotic pathway in the hippocampus after ischemia-reperfusion injury. The study aimed to estimate the efficacy of estrogen and propofol combination therapy against ERS-induced apoptosis after cerebral ischemia-reperfusion injury and oxygen-glucose deprivation (OGD) injury in the hippocampus in vivo and in vitro. METHODS: Rat model of cerebral ischemia-reperfusion injury was generated by middle cerebral artery occlusion (MCAO) strategy with ischemic intervention for 90 min and reperfusion for 24 h. Propofol processing ischemia-reperfusion group (Propofol group) infused 50 mg/kg/h of propofol via the femoral vein at the onset of reperfusion for 30 min. Estrogen processing ischemia-reperfusion group (estrogen group) received 0.0125 mg/kg of estrogen via tail vein at 30 min prior to MCAO. Combination therapy for ischemia-reperfusion group (combination group) received simultaneous processing with propofol and estrogen. In vitro, brain slices were randomly exposed to dimethylsulfoxide (DSMO), 10 µm of propofol, 10 nm of estrogen, or propofol and estrogen. Changes in the orthodromic population spike (OPS) at the end of reoxygenation were recorded. Neurological deficit examination, Nissl staining, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were employed to evaluate the level of cerebral ischemia-reperfusion injury. The expression of caspase-3, caspase-12, glucose-regulated protein 78 (GRP78), and CHOP were investigated by Western blot and immunofluorescence staining assays. Neural apoptotic rate in hippocampus was detected by the flow cytometry trial. RESULTS: Neurological deficit score, infarct volume, the expression of caspase-3 (P < 0.05), caspase-12, GRP78, CHOP, and neural apoptotic rate of I/R group increased markedly (P < 0.01). When obtaining drug treatment, neurological deficit score (P < 0.05), infarct volume, the expression levels of caspase-12 and GRP78, and neural apoptotic rate of the propofol group decreased significantly (P < 0.01). Furthermore, neurological deficit score, infarct volume, expression levels of caspase-3, caspase-12, GRP78, and CHOP (P < 0.05), and neural apoptotic rate decreased in the estrogen group (P < 0.01) and especially in the combination group (P < 0.01). Compared with the propofol group, the neurological deficit score (P < 0.05), infarct volume, caspase-3, caspase-12, GRP78, CHOP, and neural apoptotic rate of the combination group decreased (P < 0.01). Compared with the estrogen group, the infarct volume, caspase-3 (P < 0.05), GRP78, CHOP, and neural apoptotic rate (P < 0.05) of the combination group decreased (P < 0.01). Compared with the propofol group, the infarct volume, caspase-3, caspase-12 (P < 0.05), and GRP78 (P < 0.05) of the estrogen group decreased (P < 0.01). Propofol and estrogen treatment can delay the abolishing time of OPS and increase the recovery rate and amplitude of OPS, compared with OGD group (P < 0.01), especially in the combination therapy (P < 0.01). CONCLUSION: The neuroprotection of propofol and estrogen combination therapy inhibited excessive ERS-induced apoptosis against cerebral ischemia-reperfusion injury and OGD injury in the hippocampus of rats. Furthermore, the outcomes demonstrated that combination therapy yielded synergistic effects.


Assuntos
Isquemia Encefálica/prevenção & controle , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estrogênios/administração & dosagem , Glucose/deficiência , Hipocampo/efeitos dos fármacos , Propofol/administração & dosagem , Traumatismo por Reperfusão/prevenção & controle , Animais , Isquemia Encefálica/metabolismo , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Quimioterapia Combinada , Estresse do Retículo Endoplasmático/fisiologia , Hipocampo/metabolismo , Hipnóticos e Sedativos/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo
11.
Biomed Pharmacother ; 97: 429-438, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29091893

RESUMO

AIM: Aquaporins (AQPs) are water-channels that play important roles in brain water homeostasis and cerebral edema induced by brain injury. This study aimed to investigate the relationship between AQP4, bone morphogenetic protein 4 (BMP4)/Smad1/5/8 signaling pathway and isoflurane post-conditiong, which has effects on brain edema in rats with cerebral ischemia/reperfusion (I/R) injury. METHODS: Cerebral I/R injury was induced in rats by using the middle cerebral artery occlusion (MCAO) model for 90min, followed by 24h of reperfusion. Isoflurane post-conditioning (ISO) group received 90min ischemia and underwent 1.5% isoflurane post-conditioning for 60min after initiating reperfusion. Neurobehavior, brain water content, thionine staining and 2, 3, 5-triphenyl tetrazolium chloride staining were evaluated to measure levels of brain edema and damage. Expressions of AQP4, BMP4, Smad1/5/8 and phosphorylated Smad1/5/8 were detected by using Western blot, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence (IF) staining. RESULTS: Compared with the Sham group, neurological behavior score, brain infarct volume and water content of MCAO model rats increased with reperfusion injury. However, in the ISO group, cell edema and damage of brain was significantly ameliorated (P<0.01). qRT-PCR showed less AQP4 mRNA expression in the hippocampal tissue of the ISO group than in the I/R group (P<0.01). Western blot and immunofluorescence results showed similar changes in protein levels of both groups. Related protein expressions showed expressions of BMP4 and Smad1/5/8 increased in the ISO group (P<0.01), whereas total Smad1/5/8 expression didn't change in all groups. When BMP4 inhibitor (LDN193189) was injected, expression levels of AQP4 increased and neuronal density decreased (P<0.05). By contrast, expression levels of BMP4 did not change significantly after pre-injection of AQP4 inhibitor (TGN020) (P>0.05), but neuronal density increased (P<0.05). CONCLUSION: Isoflurane post-conditioning may inhibit occurrence of brain edema and reduce cerebral I/R injury through down-regulating expression of AQP4, This process may be related to the activation of BMP4/Smad1/5/8 signaling pathway.


Assuntos
Aquaporina 4/biossíntese , Proteína Morfogenética Óssea 4/biossíntese , Isquemia Encefálica/metabolismo , Pós-Condicionamento Isquêmico/métodos , Isoflurano/administração & dosagem , Traumatismo por Reperfusão/metabolismo , Proteínas Smad Reguladas por Receptor/biossíntese , Animais , Aquaporina 4/antagonistas & inibidores , Aquaporina 4/genética , Proteína Morfogenética Óssea 4/genética , Isquemia Encefálica/terapia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Expressão Gênica , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/terapia , Masculino , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/terapia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Proteínas Smad Reguladas por Receptor/genética , Proteína Smad1/biossíntese , Proteína Smad1/genética , Proteína Smad5/biossíntese , Proteína Smad5/genética , Proteína Smad8/biossíntese , Proteína Smad8/genética
12.
Yi Chuan Xue Bao ; 31(10): 1157-66, 2004 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-15552053

RESUMO

The cloning vectors pMD-DCA1 and pMD-CA containing the promoters of duplicated carbonic anhydrase 1 (DCA1) and carbonic anhydrase (CA) genes, respectively, from Dunaliella salina, and expression vector pDM307 containing bar-NOS polyA fragment were digested with EcoR I. The bar-NOS polyA fragment was fused, respectively, to the fragments of the vectors pMD-DCA1 and pMD-CA to form transgenic D. salina expression vectors pMDDC-B and pMDC-B. The micro-shots were prepared by coating two constructs (pMDDC-B and pMDC-B) with gold particle. Each sample was bombarded once, twice, and thrice, respectively, with micro-projectile gun at a rupture pressure of 690 kPa in helium gas. The screening culture of the bombarded alga cells was performed in PKS liquid and solid medium containing 3 mg/L phosphinothricin (PPT) to develop the transformed cells of D. salina. Analyses of the transformed cells were carried out through PCR, Southern blotting, and Northern blotting. The results of screening culture showed that the expression of the external bar gene of vectors pMDDC-B and pMDC-B was stable and transient, respectively, in the transformed D. salina cells. In the meantime, the transformed efficiency of particle bombardment twice was higher than that of once or thrice particle bombardment at a rupture pressure of 690 kPa in helium gas. PCR and Southern blotting analyses indicated that the external bar gene was integrated into the genome of the cells. Northern analysis indicated that expression efficiency of the bar gene driven by DCA1 promoter was regulated by the gradient concentration of sodium chloride, and the positive blotting signal intensity of the bar mRNA was highest in the medium containing 2 mol/L of sodium chloride. The findings of the present study suggest that promoter of the DCA1 gene may be an inducible promoter following a hyperosmotic shock with high activity and safety in the research of transgenic D. salina. The tandem GT sequences of the promoter region of DCA1 and CA genes may be related to the molecular mechanisms of the extreme halo-toleration of the unicellular green alga, D. salina.


Assuntos
Anidrases Carbônicas/genética , Clorófitas/genética , Regiões Promotoras Genéticas , Southern Blotting , Clorófitas/enzimologia , Clonagem Molecular , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/fisiologia
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