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1.
Zhonghua Yi Xue Za Zhi ; 100(12): 928-932, 2020 Mar 31.
Artigo em Chinês | MEDLINE | ID: mdl-32234168

RESUMO

Objective: To analyze the influencing factors of acute kidney injury (AKI) in patients after cardiac surgery using levosimendan or dobutamine, and explore the effect of positive inotropic drugs on AKI. Methods: The clinical data of 417 patients undergoing cardiac surgery from January to June 2018 in Beijing Anzhen Hospital and treated with levosimendan or dobutamine during perioperative period were retrospectively reviewed and collected. Patients were divided into AKI group and non-AKI group according to whether AKI occurred. Univariate logistic regression analysis was used to analyze the factors related to the occurrence of AKI. The statistically significant factors (P<0.05) were further included in the multivariate logistic regression analysis. Results: Totally, 417 patients were enrolled in the study, with a mean age of (58.2±10.4) years old and a male rate of 65.0% (n=271), and the AKI incidence rate was 25.2% (105/417). Univariate logistic regression analysis showed that male, chronic kidney disease, high serum creatinine level in preoperative period, aortic obstruction time ≥ 120 minutes and extracorporeal circulation time ≥ 120 minutes were risk factors for AKI (all P<0.05). Vasodilator and levosimendan treatment during perioperative period were protective factors (P<0.05). Multivariate logistic regression analysis showed that chronic kidney disease (OR=17.291, 95%CI: 4.335-68.960, P<0.001) and high serum creatinine level (OR=1.097, 95%CI: 1.074-1.121, P<0.001) in preoperative period were independent risk factors for AKI. Perioperative application of levosimendan (OR=0.533, 95%CI: 0.288-0.984, P=0.044) was an independent protective factor. Conclusions: Risk factors for AKI after cardiac surgery include chronic kidney disease and high serum creatinine level in preoperative period. The use of levosimendan during preoperative period has the potential effect to protect against AKI.


Assuntos
Injúria Renal Aguda , Procedimentos Cirúrgicos Cardíacos , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Período Pós-Operatório , Estudos Retrospectivos , Fatores de Risco
2.
Zhonghua Bing Li Xue Za Zhi ; 46(3): 166-169, 2017 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-28297756

RESUMO

Objective: To observe the histopathological changes and immunohistochemical expression of IgG4 in Riedle thyroiditis (RT) and to study the relationship between RT and IgG4-related diseases (IgG4-RD). Methods: A total of 5 RT patients were collected from the Department of Pathology, Peking Union Medical College Hospital during April 2012 to August 2014. The clinical and immunohistochemical features were analyzed in the 5 patients. Histopathologic analysis was performed on hematoxylin and eosin-stained sections. Results: There were one male and four female patients, aged 52 to 78 years (median 59 years). Five cases were characterized by multiple nodules of thyroid, which increased year by year. All patients were found to have surrounding tissue compression symptoms and signs. Two female patients were found to have hypothyroidism. The serum concentration of IgG was elevated in 2 cases, and the serum concentration of IgG was not tested before operation in the remaining patients. By ultrasound, all presented as low echo or medium low echo. Strong echo occasionally appeared in hypoechoic nodules. Microscopically, fibrous tissue hyperplasia was infiltrated with varying numbers of lymphocytes and plasma cells. The occlusion of phlebitis was found in 4 cases and eosinophils were found in 3 cases. IgG4 counts and IgG4/IgG ratios in 5 cases were 20/HPF, 16%; 60/HPF, 82%; 22/HPF, 28%; 400/HPF, 266% and 33/HPF, 71%, respectively. Conclusions: With the similar pathological manifestations between RT and IgG4-RD, immunohistochemical staining shows that the number of IgG4 positive plasma cells and IgG4/IgG ratio of RT are increased in varying degrees. Some cases meet the diagnostic criteria of IgG4-RD, and speculate that some cases of RT belong to IgG4-RD.


Assuntos
Imunoglobulina G/metabolismo , Flebite/patologia , Plasmócitos/patologia , Tireoidite/patologia , Adulto , Idoso , Eosinófilos/patologia , Feminino , Humanos , Imunoglobulina G/sangue , Imuno-Histoquímica , Linfócitos/patologia , Masculino , Pessoa de Meia-Idade , Tireoidite/diagnóstico
4.
Osteoarthritis Cartilage ; 23(2): 210-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25433273

RESUMO

OBJECTIVE: To investigate the relationship between SEPS1 polymorphism and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in Kashin-Beck disease (KBD) and further explore the pathogenesis of KBD. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect SEPS1 -105G>A polymorphism in 232 cases and 331 controls. The protein expressions of PI3K/Akt signaling molecules in whole blood and chondrocytes were detected by Western blot. RESULTS: The frequencies of SEPS1 -105G>A genotype AA (21.1% vs 3.0%) and minor allele A (34.1% vs 16.0%) in KBD are significantly higher than those in controls (OR: 8.020, 95% confidence interval (95% CI) 6.341-10.290, P < 0.0001; OR: 2.470, 95% CI 2.001-4.463, P < 0.0001, respectively). SEPS1 AA genotype was an independent risk factor for KBD (adjusted OR: 9.345, 95% CI 4.254-20.529; P < 0.0001). The expression of Gßγ, PI3Kp110, pAkt and pGSK3ß in KBD group were higher than that in control group (all P < 0.05). Gßγ, pAkt and pGSK3ß protein expression of AA and GA increased than GG (all P < 0.05). Cell apoptosis was increasing and molecule expression of PI3K/Akt signaling pathway were up-regulated in the tert-Butyl hydroperoxide (tBHP)-injured group, the cell apoptosis and expression levels of PI3K/Akt in Na2SeO3 group were decreased. CONCLUSIONS: The SEPS1 -105G>A is associated with an increased risk of KBD and influences the expression of PI3K/Akt signaling pathway in KBD patients. Apoptosis induced by tBHP in chondrocyte might be mediated via up-regulation of PI3K/Akt, Na2SeO3 has an effect of anti-apoptosis by down-regulating of PI3K/Akt signaling pathway.


Assuntos
Doença de Kashin-Bek/etiologia , Proteínas de Membrana/genética , Fosfatidilinositol 3-Quinase/fisiologia , Polimorfismo Genético , Proteínas Proto-Oncogênicas c-akt/fisiologia , Selenoproteínas/genética , Transdução de Sinais , Estudos de Casos e Controles , Feminino , Humanos , Doença de Kashin-Bek/genética , Masculino , Pessoa de Meia-Idade
5.
Zhonghua Shao Shang Za Zhi ; 38(4): 378-384, 2022 Apr 20.
Artigo em Chinês | MEDLINE | ID: mdl-35462518

RESUMO

With the aging of population and the development of social economy, the incidence of chronic wounds is increasing day by day, while the incidence of burns and trauma remains at a high level, making wound repair an increasingly concerned area in clinical practice. Thymosin ß4 is a naturally occurring small molecule protein in vivo, which is widely distributed in a variety of body fluids and cells, especially in platelets. Thymosin ß4 has biological activities of promoting angiogenesis, anti-inflammation, anti-apoptosis, and anti-fibrosis, and has many important functions in wound repair. Thymosin ß4 has been observed to promote the healing of various wounds, such as burns, diabetic ulcers, pressure ulcers. This paper will review the molecular structure, mechanism of wound healing promotion, pharmacokinetics, and clinical application of thymosin ß4, aiming to introduce its potential in wound treatment and the shortcomings of current researches.


Assuntos
Timosina , Cicatrização , Queimaduras/tratamento farmacológico , Humanos , Úlcera por Pressão , Timosina/química , Timosina/metabolismo , Timosina/farmacologia , Timosina/uso terapêutico , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
6.
J Int Med Res ; 36(1): 178-86, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18304418

RESUMO

Effectiveness and mechanism of action of andrographolide on the recovery of Pseudomonas aeruginosa susceptibility to antibiotics was investigated. In the presence of andrographolide, the Mueller-Hinton broth dilution method measured minimal inhibitory concentrations (MIC) of ceftazidine, cefpirome, chloramphenicol, L-ofloxacin, kanamycin, imipenem and meropenem. Real-time fluorescence quantitative polymerase chain reaction was used to determine mexB mRNA expressions in P. aeruginosa PAO1 strain and MexAB-OprM overexpressing strain. Relative mexB mRNA expression was detected in both strains incubated for 3 and 9 h. When andrographolide-treated groups were compared with controls, the MIC of ceftazidine, cefpirome, L-ofloxacin and meropenem for both strains decreased, and the relative mexB mRNA expression was significantly lower, although between andrographolide groups there were no significant differences. Compared with the inactivated quorum-sensing system, relative amounts of mexB mRNA in the PAO1 strain and MexAB-OprM overexpressing strain in the activated quorum-sensing system increased 10- and 30-fold, respectively. Andrographolide recovered P. aeruginosa susceptibility to antibiotics and reduced the MexAB-OprM efflux pump expression level.


Assuntos
Antibacterianos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Diterpenos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Relação Dose-Resposta a Droga , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , RNA Bacteriano/análise , RNA Mensageiro/metabolismo
7.
J Mol Biol ; 216(2): 275-87, 1990 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-2254929

RESUMO

A series of deletion mutants of the wild-type Escherichia coli lactose promoter, with endpoints at +25, +19, +14, +1 and -6 (relative to the start of transcription at +1), was constructed and the deleted DNA replaced with non-lac DNA. These mutants were used to show that no specific DNA sequences downstream from -6 are required for efficient promoter utilization in vitro. In all cases transcription is dependent on the presence of the catabolite activator protein (CAP) and cAMP, and begins at +1 at a level indistinguishable from that at the wild-type promoter. A set of lac DNA fragments deleted to -6 was constructed, having an A, C, G or T residue at +1 and heterologous DNA downstream. These synthetic promoters allow systematic testing of the effect of the initiating nucleotide on the transcription process. Again, transcription occurs mainly from +1, at a level similar to the normal wild-type level. No substantial differences between these promoters are observed in the rates of formation of stable complexes, in the degree of complex formation, in the rate at which polymerase "escapes" from the complex or in abortive transcription products. Equivalent results are seen with a related set of constructs based on the CAP-insensitive lac UV5 promoter. Thus, lac promoter sequences including consensus hexamers at -10 and -35, plus the spacer region between them, provide specificity and efficiency both in initiation of transcription by RNA polymerase and in CAP-polymerase interactions. A question as to whether there is a third RNA polymerase binding site at lac, in addition to the known overlapping P1 and P2 regions, was not unambiguously answered. However, if a "P3" site does exist, it must lie between P1 and P2. Alternatively, the variety of polymerase interactions at wild-type lac may reflect different structural states of the enzyme. The results presented here indicate that DNA downstream from -6 plays little part in determining the conformation of the enzyme at the lactose promoter.


Assuntos
Escherichia coli/genética , Genes Bacterianos , Lactose/metabolismo , Regiões Promotoras Genéticas , Transcrição Gênica , Sequência de Bases , Deleção Cromossômica , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Cinética , Dados de Sequência Molecular , Mutação , Mapeamento por Restrição
8.
Neuroscience ; 284: 546-554, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25453775

RESUMO

EphB receptors and their ephrinB ligands are implicated in modulating of spinal nociceptive information processing. Here, we investigated whether protein kinase A (PKA), acts as a downstream effector, participates in the modulation spinal nociceptive information related to ephrinB-EphB signaling. Intrathecal injection of ephrinB2-Fc caused thermal hyperalgesia and mechanical allodynia, which were accompanied by increased expression of spinal PKA catalytic subunit (PKAca) and phosphorylated cAMP-response element-binding protein (p-CREB). Pre-treatment with H89, a PKA inhibitor, prevented the activation of CREB by ephrinB2-Fc. Inhibition of spinal PKA signaling prevented and reversed pain behaviors induced by the intrathecal injection of ephrinB2-Fc. Furthermore, blockade of the EphB receptors by intrathecal injection of EphB2-Fc reduced formalin-induced inflammatory, chronic constrictive injury (CCI)-induced neuropathic, and tibia bone cavity tumor cell implantation (TCI)-induced bone cancer pain behaviors, which were accompanied by decreased expression of spinal PKAca and p-CREB. Overall, these results confirmed the important involvement of PKA in the modulation of spinal nociceptive information related to ephrinBs-EphBs signaling. This finding may have important implications for exploring the roles and mechanisms of ephrinB-EphB signaling in physiologic and pathologic pain.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Efrina-B2/metabolismo , Nociceptividade/fisiologia , Receptores da Família Eph/metabolismo , Medula Espinal/metabolismo , Animais , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/fisiopatologia , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Modelos Animais de Doenças , Efrina-B2/administração & dosagem , Hiperalgesia/tratamento farmacológico , Hiperalgesia/fisiopatologia , Inflamação/tratamento farmacológico , Inflamação/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neuralgia/tratamento farmacológico , Neuralgia/fisiopatologia , Nociceptividade/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Receptores da Família Eph/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos
9.
Eur J Pain ; 19(9): 1277-87, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25919495

RESUMO

BACKGROUND: EphB receptors and their ephrinB ligands are implicated in modulating spinal nociceptive information processing. Here, we investigated whether cyclooxygenase-2 (COX-2), acts as a downstream effector, participates in the modulation of spinal nociceptive information related to ephrinB/EphB signalling. METHODS: Thermal hyperalgesia and mechanical allodynia were measured by using radiant heat and von Frey filaments test, respectively. Real-time PCR (RT-PCR) was used to detect the expression of spinal COX-2 mRNA. Spinal COX-2 and extracellular signal-regulated kinase (ERK) protein were determined by Western blot analysis. RESULTS: Intrathecal injection of ephrinB2-Fc caused thermal hyperalgesia and mechanical allodynia, which were accompanied by increased expression of spinal COX-2 mRNA and protein. Inhibition of spinal COX-2 prevented and reversed pain behaviours induced by the intrathecal injection of ephrinB2-Fc. Blockade of EphB receptors by intrathecal injection of EphB2-Fc reduced complete Freund's adjuvant (CFA)-induced inflammatory pain behaviours, which were accompanied by decreased expression of spinal COX-2 mRNA and protein. Furthermore, treatment with U0126, a mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor, suppressed spinal ERK activation and COX-2 mRNA and protein expression induced by intrathecal injection of ephrinB1-Fc. CONCLUSIONS: These results confirmed the important involvement of COX-2 in the modulation of spinal nociceptive information related to ephrinBs-EphBs signalling.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Efrina-B2/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hiperalgesia/metabolismo , Nociceptividade/fisiologia , Receptores da Família Eph/metabolismo , Transdução de Sinais/fisiologia , Medula Espinal/metabolismo , Animais , Modelos Animais de Doenças , Efrina-B2/administração & dosagem , Hiperalgesia/induzido quimicamente , Hiperalgesia/diagnóstico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo , Receptores da Família Eph/efeitos dos fármacos
10.
Neuroscience ; 307: 64-72, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26318332

RESUMO

Spinal ephrinB-EphB signaling is involved in the modulation of pain processing. The aim of the present study was to investigate whether protein kinase C-γ (PKCγ) acts as a downstream effector in regulating spinal pain processing associated with ephrinB-EphB signaling in mice. The intrathecal injection of ephrinB2-Fc, an EphB receptor activator, caused thermal hyperalgesia and mechanical allodynia, as well as increased activation of spinal PKCγ. Knockdown of spinal PKCγ prevented the pain behaviors induced by ephrinB2-Fc. Furthermore, the intrathecal injection of EphB2-Fc, an EphB receptor blocker, suppressed formalin-induced inflammatory, chronic constriction injury (CCI)-induced neuropathic, and tibia bone cavity tumor cell implantation (TCI)-induced bone cancer pain behaviors, in addition to reducing the activation of spinal PKCγ. Finally, the intrathecal injection of MK801, an N-methyl-D-aspartate (NMDA) receptor blocker, prevented the pain behaviors and spinal PKCγ activation induced by ephrinB2-Fc. Overall, the results confirm the important role of PKCγ in the regulation of spinal pain processing associated with ephrinB-EphB signaling.


Assuntos
Efrina-B2/metabolismo , Neuralgia/metabolismo , Proteína Quinase C/metabolismo , Receptores da Família Eph/metabolismo , Transdução de Sinais/fisiologia , Análise de Variância , Animais , Neoplasias Ósseas/complicações , Modelos Animais de Doenças , Efrina-B2/química , Efrina-B2/toxicidade , Formaldeído/toxicidade , Hiperalgesia/fisiopatologia , Injeções Espinhais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuralgia/induzido quimicamente , Neuralgia/etiologia , Proteína Quinase C/genética , RNA Interferente Pequeno/farmacologia , Receptores da Família Eph/toxicidade , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
11.
Sheng Li Xue Bao ; 52(3): 235-8, 2000 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-11956571

RESUMO

Fos immunocytochemistry, NADPH-d histochemistry and Fos/NADPH-d double-labeling method were used to study the changes in formalin-induced Fos, NADPH-d positive and Fos/NADPH-d double-labeled neurons in the spinal cord of morphine-tolerant rats. Formalin-induced Fos-like immunoreactivity (Fos-LI) was located in the superficial laminae and neck of ipsilateral spinal cord. Acute administration of morphine decreased the expression of Fos-LI in non-tolerant rats, while the expression of Fos-LI was significantly increased in morphine-tolerant rats. Fos-LI was distributed not only in the whole laminae of the ipsilateral spinal cord but also in the contralateral spinal cord. Acute administration of morphine was ineffective in decreasing the expression of Fos-LI in morphine-tolerant rats. Morphine tolerance increased the expression of formalin-induced NADPH-d positive neurons in the superficial laminae of spinal dorsal horn. A few formalin-induced Fos/NADPH-d double-labeled neurons were detected in the superficial laminae of spinal dorsal horn of non-tolerant rats. In morphine-tolerant rats, on the other hand, formalin-induced Fos/NADPH-d double-labeled neurons were increased and distributed in the whole laminae of the ipsilateral spinal cord and the contralateral superficial spinal cord. It is suggested that NO is involved in the increase of formalin-induced Fos-LI in the spinal cord of morphine-tolerant rats and may play an important role in the development of morphine tolerance.


Assuntos
Tolerância a Medicamentos , Morfina , Dor/fisiopatologia , Proteínas Proto-Oncogênicas c-fos/biossíntese , Medula Espinal/metabolismo , Animais , Formaldeído , Masculino , Morfina/farmacologia , NADPH Desidrogenase/biossíntese , NADPH Desidrogenase/genética , Neurônios/fisiologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo I , Dor/induzido quimicamente , Proteínas Proto-Oncogênicas c-fos/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Medula Espinal/fisiologia
12.
Sheng Li Xue Bao ; 53(1): 27-31, 2001 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-11354793

RESUMO

Methods of reverse transcription polymerase chain reaction (RT-PCR), intrathecal injection and antisense drugs were used to study the effects of nitric oxide (NO) on the scores of morphine-withdrawal syndrome and the expression of NMDA1AR mRNA in rat spinal cord and brainstem. Intrathecal injection of NOS antisense oligonucleotides (AS-ONs) significantly decreased the scores of morphine-withdrawal symptoms. The effect of nNOS AS-ONs was greater than that of eNOS AS-ONs. The expression of NMDA1AR mRNA in the spinal cord and brainstem increased in morphine-dependent rats and increased to a greater extent in morphine-withdrawal rats. Intrathecal injection of nNOS AS-ONs significantly inhibited the increased expression of NMDA1AR mRNA in the spinal cord and brainstem of morphine-withdrawal rats. Intrathecal injection of eNOS antisense oligonucleotides inhibited the expression of NMDA1AR mRNA in the spinal cord of morphine-withdrawal rats, but did not in the brainstem. It is suggested that NO mediates morphine-withdrawal reaction and participates in modulating the expression of NMDA1AR mRNA in morphine-withdrawal rats.


Assuntos
Tronco Encefálico/metabolismo , Morfina/efeitos adversos , Óxido Nítrico Sintase , Oligonucleotídeos Antissenso/farmacologia , Receptores de N-Metil-D-Aspartato/biossíntese , Medula Espinal/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Injeções Espinhais , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/genética , Síndrome de Abstinência a Substâncias/tratamento farmacológico
13.
Sheng Li Xue Bao ; 53(1): 75-8, 2001 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-11354804

RESUMO

The effects of nitric oxide (NO) on the activation of spinal cord neurons were studied using immunocytochemistry, intrathecal injection and antisense oligonucleotides (AS-ONs) techniques in morphine-withdrawal rats. Acute administration of naloxone and chronic administration of morphine changed neither the expression of Fos-LI and NADPH-d positive neurons nor the expression of Fos/NADPH-d double-labeled neurons in the spinal cord of rats. Fos-LI, NADPH-d positive and Fos/NADPH-d double-labeled neurons were increased significantly in number in morphine-withdrawal rats and they were observed in all the laminae of the spinal cord. Intrathecal injection of L-NA, nNOS antisense oligonucleotides significantly inhibited the expression of Fos-LI in the spinal cord and decreased the scores for morphine-withdrawal symptoms in morphine-withdrawal rats, but not in nNOS-S group. The results suggest that NO mediates the spinal neurons sensitization in morphine-withdrawal rats.


Assuntos
Morfina/efeitos adversos , Óxido Nítrico/fisiologia , Medula Espinal/fisiopatologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Medula Espinal/patologia
14.
Biochemistry ; 30(10): 2642-50, 1991 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-1848093

RESUMO

To begin to assess the independent structural and functional characteristics of the mitochondrially encoded subunits of mammalian cytochrome c oxidase, we have converted the cloned mitochondrial gene for rat subunit II (coxII) into its universal codon equivalent (ucoxII) by oligonucleotide-directed, site-specific mutagenesis. This involved synthesizing 12 oligodeoxynucleotides to achieve the 13 ATA to ATG and the 5 TGA to TGG changes needed. To express ucoxII in Escherichia coli, we used a number of different expression vectors in which the promoters and ribosome-binding sequences of the messenger RNA were varied. While ucoxII alone was expressed at a low level, a striking increase in the level of expression resulted when the ucoxII gene was fused to other E. coli genes. The COXII peptide was identified by proteolytic digestion, partial sequencing, and reaction with specific antisera. A cro-beta-galactosidase-COXII fusion protein has been purified, characterized, and used to produce polyclonal antibodies to the COXII peptide. The ucoxII gene was also expressed in a cell-free translation system and in Xenopus oocytes, yielding a nondenatured, membrane-associated peptide with the same apparent molecular weight as authentic subunit II. In oocytes and in a reticulocyte lysate in vitro system supplemented with microsomal membranes, the protein is glycosylated and coisolates with the washed membrane fraction. In both cases, the COXII peptide is soluble under mild conditions in a nonionic detergent and is precipitable by antibodies to subunit II. The production of subunit II in the in vitro translation system is stimulated as strongly by addition of soybean phospholipid vesicles as by microsomal membranes, providing further evidence of membrane insertion and stabilization.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Mitocôndrias Hepáticas/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Códon , DNA Mitocondrial/genética , Eletroforese em Gel de Poliacrilamida , Feminino , Regulação Enzimológica da Expressão Gênica , Mamíferos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Plasmídeos , Testes de Precipitina , Biossíntese de Proteínas , Coelhos , Ratos , Espectrometria de Fluorescência , Xenopus laevis
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