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1.
Autophagy ; 19(5): 1601-1603, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36170592

RESUMO

Mitochondria rely on efficient protein import across their membranes for optimal function. We have shown that numerous mitochondrial stressors all converge on a common pathway disrupting this import efficiency. We identified a novel pathway involving NLRX1 and RRBP1 that responds to this import stress, resulting in LC3 lipidation, mitochondrial targeting and ultimate degradation. Furthermore, we demonstrated the relevance of this mitophagy axis in murine skeletal muscle following acute exercise. We propose that mitochondrial protein import stress is an underlying, common trigger for mitophagy, offering a novel avenue for therapeutic exploration and mechanistic insight.


Assuntos
Autofagia , Mitofagia , Animais , Camundongos , Mitofagia/fisiologia , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo , Proteínas Mitocondriais/metabolismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-36034951

RESUMO

The effect of Chaihu Shugan pills (CHSG) on the pharmacokinetics of duloxetine and its metabolite 4-hydroxyduloxetine in beagle dogs was investigated by establishing an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to simultaneously measure the concentrations of duloxetine and 4-hydroxyduloxetine in beagle dog plasma. Duloxetine and 4-hydroxyduloxetine were separated on the UPLC-C18 column after acetonitrile precipitation and detected by mass spectrometry with multireaction detection mode (MRM). Six adult healthy beagle dogs (weighing 7-9 kg, male and female) were randomly selected and examined for a single-dose administration of duloxetine hydrochloride (2 mg/kg, control group) and oral administration of CHSG (0.3 g/kg) twice daily for 15 consecutive days followed by a single-dose administration of duloxetine hydrochloride (2 mg/kg, experimental group) using the self-control method. All plasma samples were treated in the same way, and then the concentrations of duloxetine and 4-hydroxyduloxetine were determined using the established UPLC-MS/MS method. The obtained data were subjected to DAS 2.0 software to calculate the pharmacokinetic parameters, and SPSS 20.0 software was used to compare the differences between the two groups. Duloxetine and 4-hydroxyduloxetine had a good linear relationship in the ranges of 1-1000 ng/ml and 0.1-100 ng/ml, and the lower limits of quantification (LLOQ) were 1 ng/mL and 0.1 ng/ml, respectively. The precision, accuracy, extraction recovery, matrix effect, and stability meet the requirements of the guiding principles. After combination with CHSG, C max and AUC0⟶t of duloxetine decreased by 49.33% and 13.08%, respectively, and t 1/2 was shortened to 10.17 h; C max and AUC0⟶t of 4-hydroxyduloxetine decreased by 71.47% and 48.78%, respectively, and t 1/2 was shortened to 7.97 h. The UPLC-MS/MS method was fully developed to simultaneously measure the plasma concentration of duloxetine and its metabolite 4-hydroxyduloxetine in beagle dogs. CHSG could slow down the absorption of duloxetine, induce the metabolism of duloxetine and 4-hydroxyduloxetine in beagle dogs, and reduce plasma exposure.

3.
Mol Cell ; 82(15): 2815-2831.e5, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35752171

RESUMO

Protein import into mitochondria is a highly regulated process, yet how cells clear mitochondria undergoing dysfunctional protein import remains poorly characterized. Here we showed that mitochondrial protein import stress (MPIS) triggers localized LC3 lipidation. This arm of the mitophagy pathway occurs through the Nod-like receptor (NLR) protein NLRX1 while, surprisingly, without the engagement of the canonical mitophagy protein PINK1. Mitochondrial depolarization, which itself induces MPIS, also required NLRX1 for LC3 lipidation. While normally targeted to the mitochondrial matrix, cytosol-retained NLRX1 recruited RRBP1, a ribosome-binding transmembrane protein of the endoplasmic reticulum, which relocated to the mitochondrial vicinity during MPIS, and the NLRX1/RRBP1 complex in turn controlled the recruitment and lipidation of LC3. Furthermore, NLRX1 controlled skeletal muscle mitophagy in vivo and regulated endurance capacity during exercise. Thus, localization and lipidation of LC3 at the site of mitophagosome formation is a regulated step of mitophagy controlled by NLRX1/RRBP1 in response to MPIS.


Assuntos
Proteínas Mitocondriais , Mitofagia , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Transporte Proteico
4.
Immunol Lett ; 170: 88-94, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26349055

RESUMO

The receptor for advanced glycation end products (RAGE) and its proinflammatory ligands are critically implicated in the pathological progression of ulcerative colitis (UC). Functional polymorphisms in the regulatory elements and/or ligand-binding regions of the RAGE gene affect the expression and function of RAGE and thus may increase susceptibility to UC. In this study, a total of 266 unrelated UC patients and 247 control subjects were analyzed for 3 RAGE single nucleotide polymorphisms (SNPs) (-429 T/C, -374 T/A, and G82S) using an improved small-amplicon high resolution melting curve (HRM) analysis assay. Serum levels of soluble RAGE (sRAGE) were determined by a double sandwich ELISA system. The genotypes, alleles and haplotypes were analyzed and compared between UC patients and control subjects. Three pairs of genotyping primers for three RAGE polymorphism loci (-429 T/C, -374 T/A, and G82S) were developed based on HRM. Significant differences in the allele distribution of the G82S polymorphism was found among UC cases and controls from a Chinese population. Carriers of the RAGE G82S variant genotype were at higher risk of UC (OR=2.594, 95% CI: 1.778-3.784, P<0.001) than homozygous wild-type individuals. Further analyses revealed that the 82 (GS+SS) variant genotype was associated with patients who have extended UC (OR=1.924, 95% CI: 1.163-3.181, P=0.010), and a family history of inflammatory bowel disease (IBD) (OR=1.923, 95% CI: 1.049-3.521, P=0.032). The polymorphisms -374 T/A and -429 T/C did not demonstrate any association with UC, but an association was found between the -374(TA+AA) variant genotypes and the serum sRAGE level (P=0.002). Moreover, haplotypes T/A/A and T/A/G showed significantly different frequencies between UC patients and controls (OR=3.337, 95% CI: 1.892-6.091, P=0.026; OR=0.530, 95% CI: 0.351-0.801, P=0.002). The present study developed novel primers based on HRM to provide preliminary evidence in a Chinese population that the RAGE polymorphism is involved in genetic susceptibility to UC and that the 82(GS+SS) genotype of G82S is a risk factor for UC. Furthermore, RAGE polymorphisms may be related to the location of UC as well as a family history of IBD in a Chinese population.


Assuntos
Povo Asiático/genética , Colite Ulcerativa/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Receptor para Produtos Finais de Glicação Avançada/genética , Adulto , Alelos , Biomarcadores , Estudos de Casos e Controles , China , Colite Ulcerativa/sangue , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Receptor para Produtos Finais de Glicação Avançada/sangue , Risco
5.
Peptides ; 59: 70-4, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25073070

RESUMO

Copeptin can reflect individual's stress state and are correlated with poor outcome of critical illness. The occurrence of postoperative delirium (POD) and cognitive dysfunction (POCD) is associated with worse outcome after coronary artery bypass graft (CABG) surgery. The present study aimed to investigate the ability of postoperative plasma copeptin level to predict POD and POCD in patients undergoing CABG surgery. Postoperative plasma copeptin levels of 108 patients were measured by an enzyme-linked immunosorbent assay. It was demonstrated that plasma copeptin levels were substantially higher in patients with POD than without POD (1.8±0.6 ng/mL vs. 1.1±0.3 ng/mL; P<0.001) and in patients with POCD than without POCD (1.9±0.6 ng/mL vs. 1.1±0.4 ng/mL; P<0.001). Plasma copeptin level and age were identified as independent predictors for POD [odds ratio (OR), 67.386; 95% confidence interval (CI), 12.031-377.426; P<0.001 and OR, 1.202; 95% CI, 1.075-1.345; P=0.001] and POCD (OR, 28.814; 95% CI, 7.131-116.425; P<0.001 and OR, 1.151; 95% CI, 1.030-1.285; P=0.003) using a multivariate analysis. For prediction of POD, the area under receiver operating characteristic curve (AUC) of the copeptin concentration (AUC, 0.883; 95% CI, 0.807-0.937) was markedly higher than that of age (AUC, 0.746; 95% CI, 0.653-0.825; P=0.020). For prediction of POCD, the AUC of the copeptin concentration (AUC, 0.870; 95% CI, 0.792-0.927) was markedly higher than that of age (AUC, 0.735; 95% CI, 0.641-0.815; P=0.043). Thus, postoperative plasma copeptin level may be a useful, complementary tool to predict POD and POCD in patients undergoing CABG surgery.


Assuntos
Transtornos Cognitivos/sangue , Transtornos Cognitivos/diagnóstico , Ponte de Artéria Coronária , Delírio/sangue , Delírio/diagnóstico , Glicopeptídeos/sangue , Idoso , Transtornos Cognitivos/cirurgia , Delírio/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Chin Med J (Engl) ; 127(5): 810-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24571867

RESUMO

BACKGROUND: Protectin D1 (PD1), derived from docosahexaenoic acid, has been shown to control and resolve inflammation in some experimental models of inflammatory disorders. We investigated the protective roles of protectin D1 in pulmonary inflammation and lung injury induced by lipopolysaccharide (LPS). METHODS: Mice were randomly assigned to six groups (n = 6 per group): sham-vehicle group, sham-PD1 group, sham-zVAD-fmk group, LPS-vehicle group, LPS-PD1 group, and LPS-PD1-zVAD-fmk group. Mice were injected intratracheally with 3 mg/kg LPS or saline, followed 24 hours later by intravenous injection of 200 µg/mouse PD1 or vehicle. At the same time, some mice were also injected intraperitoneally with the pan-caspase inhibitor zVAD-fmk. Seventy-two hours after LPS challenge, samples of pulmonary tissue and bronchoalveolar lavage fluid were collected. Optical microscopy was used to examine pathological changes in lungs. Cellularity and protein concentration in bronchoalveolar lavage fluid were analyzed. Lung wet/dry ratios and myeloperoxidase activity were measured. Apoptosis of neutrophils in bronchoalveolar lavage fluid (BALF) was also evaluated by flow cytometry. RESULTS: Intratracheal instillation of LPS increased neutrophil counts, protein concentration in bronchoalveolar lavage fluid and myeloperoxidase activity, it induced lung histological injury and edema, and also suppressed apoptosis of neutrophils in BALF. Posttreatment with PD1 inhibited LPS-evoked changes in BALF neutrophil counts and protein concentration and lung myeloperoxidase activity, with the outcome of decreased pulmonary edema and histological injury. In addition, PD1 promoted apoptosis of neutrophils in BALF. The beneficial effects of PD1 were blocked by zVAD-fmk. CONCLUSION: Posttreatment with PD1 enhances resolution of lung inflammation during LPS-induced acute lung injury by enhancing apoptosis in emigrated neutrophils, which is, at least in part, caspase-dependent.


Assuntos
Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Ácidos Docosa-Hexaenoicos/uso terapêutico , Inflamação/tratamento farmacológico , Lipopolissacarídeos/toxicidade , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Lesão Pulmonar Aguda/imunologia , Animais , Apoptose/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo
7.
Biomed Res Int ; 2013: 760904, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24195079

RESUMO

During growth, C. botulinum is always exposed to different environmental changes, such as temperature increase, nutrient deprivation, and pH change; however, its corresponding global transcriptional profile is uncharacterized. This study is the first description of the genome-wide gene expression profile of C. botulinum in response to heat shock stress. Under heat stress (temperature shift from 37°C to 45°C over a period of 15 min), 176 C. botulinum ATCC 3502 genes were differentially expressed. The response included overexpression of heat shock protein genes (dnaK operon, groESL, hsp20, and htpG) and downregulation of aminoacyl-tRNA synthetase genes (valS, queA, tyrR, and gatAB) and ribosomal and cell division protein genes (ftsZ and ftsH). In parallel, several transcriptional regulators (marR, merR, and ompR families) were induced, suggesting their involvement in reshuffling of the gene expression profile. In addition, many ABC transporters (oligopeptide transport system), energy production and conversion related genes (glpA and hupL), cell wall and membrane biogenesis related genes (fabZ, fabF, and fabG), flagella-associated genes (flhA, flhM, flhJ, flhS, and motAB), and hypothetical genes also showed changed expression patterns, indicating that they may play important roles in survival under high temperatures.


Assuntos
Proteínas de Bactérias/biossíntese , Clostridium botulinum/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Resposta ao Choque Térmico/fisiologia , Viabilidade Microbiana , Proteínas de Bactérias/genética , Clostridium botulinum/genética , Perfilação da Expressão Gênica , Genes Bacterianos/fisiologia , Temperatura Alta
8.
Zhonghua Yi Xue Za Zhi ; 91(26): 1825-9, 2011 Jul 12.
Artigo em Chinês | MEDLINE | ID: mdl-22093783

RESUMO

OBJECTIVE: To investigate the association of interleukin 8 (IL-8) gene polymorphisms with the risks of inflammatory bowel disease (IBD). METHODS: Single nucleotide polymorphisms (SNPs) of IL-8 gene at -845 T/C, -738 T/A, -353 A/T, -251 T/A and +678 T/C were analyzed in 183 IBD patients. They included Crohn's disease (CD, n = 41), ulcerative colitis (UC, n = 142) and healthy controls (n = 160). The methods of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and polymerase chain reaction-sequence specific primers (PCR-SSP) were employed. RESULTS: No association was observed between any of these five SNPs in IL-8 gene with the occurrence of IBD. A specific haplotype AAT (-353 A/T, -251 T/A & +678 T/C) was over-represented in UC cases when compared with controls (31.0% vs 23.7%, P = 0.046). But the distributions of this haplotype did not show significant difference between CD cases and controls. CONCLUSION: Our data support a significant but modest association between the AAT haplotype of IL-8 gene and UC (OR = 1.441, 95%CI 1.007 - 2.063).


Assuntos
Doenças Inflamatórias Intestinais/genética , Interleucina-8/genética , Polimorfismo de Nucleotídeo Único , Adulto , Povo Asiático/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença/epidemiologia , Genótipo , Humanos , Doenças Inflamatórias Intestinais/epidemiologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição , Adulto Jovem
9.
PLoS One ; 6(10): e25777, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22022447

RESUMO

Streptococcus thermophilus, a gram-positive facultative anaerobe, is one of the most important lactic acid bacteria widely used in the dairy fermentation industry. In this study, we have analyzed the global transcriptional profiling of S. thermophilus upon temperature change. During a temperature shift from 42°C to 50°C, it is found that 196 (10.4%) genes show differential expression with 102 up-regulated and 94 down-regulated at 50°C. In particular, 1) Heat shock genes, such as DnaK, GroESL and clpL, are identified to be elevated at 50°C; 2) Transcriptional regulators, such as HrcA, CtsR, Fur, MarR and MerR family, are differentially expressed, indicating the complex molecular mechanisms of S. thermophilus adapting to heat shock; 3) Genes associated with signal transduction, cell wall genes, iron homeostasis, ABC transporters and restriction-modification system were induced; 4) A large number of the differentially expressed genes are hypothetical genes of unknown function, indicating that much remains to be investigated about the heat shock response of S. thermophilus. Experimental investigation of selected heat shock gene ClpL shows that it plays an important role in the physiology of S. thermophilus at high temperature and meanwhile we confirmed ClpL as a member of the CtsR regulon. Overall, this study has contributed to the underlying adaptive molecular mechanisms of S. thermophilus upon temperature change and provides a basis for future in-depth functional studies.


Assuntos
Adaptação Fisiológica/genética , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Resposta ao Choque Térmico/genética , Streptococcus thermophilus/genética , Transcriptoma , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Bases de Dados Genéticas , Genes Bacterianos/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Família Multigênica/genética , Análise de Sequência com Séries de Oligonucleotídeos , Reprodutibilidade dos Testes , Transdução de Sinais/genética , Temperatura , Transcrição Gênica
10.
Zhonghua Yi Xue Za Zhi ; 91(18): 1250-3, 2011 May 17.
Artigo em Chinês | MEDLINE | ID: mdl-21756796

RESUMO

OBJECTIVE: To investigate whether the macrophage inflammatory protein 1 alpha (MIP-1α) and apolipoprotein E (ApoE) gene polymorphisms, either alone or in combination, affect the susceptibility to inflammatory bowel disease (IBD). METHODS: Genomic DNA of IBD patients with Crohn's disease (CD, n = 41) and with ulcerative colitis (UC, n = 142) and healthy controls (n = 160) was extracted and genotyped for the MIP-1α and ApoE gene polymorphisms by restriction fragment length polymorphism assay. RESULTS: MIP-1α -906(TA)(6)/(TA)(6) homozygotes had a significantly elevated risk of UC (OR = 1.909, 95%CI = 1.204 - 3.028). The carriers of APOE4ε4 were at a significantly higher risk for UC with OR of 2.379 (95% CI = 1.451 - 3.896). And a combination of these two loci, MIP-1α -906(TA)(6)/(TA)(6)/APOE4ε4 were strongly associated with a higher risk of UC (OR = 3.288; 95%CI = 1.777 - 6.084). CONCLUSION: The polymorphisms of MIP-1α -906 (TA)(6)/(TA)(6) and ApoE are probably independent genetic risk factors for UC. And the coexistence of both may exert an additive effect on the UC risks.


Assuntos
Apolipoproteínas E/genética , Quimiocina CCL3/genética , Colite Ulcerativa/genética , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Adulto , Estudos de Casos e Controles , Doença de Crohn/genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Acta Pharmacol Sin ; 28(2): 202-10, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17241522

RESUMO

AIM: To demonstrate the hypothesis that dexamethasone (Dex) could improve chronic heart failure (CHF) by inhibiting the downstream signaling transduction of leptin but had no influence on the upregulation of leptin and its receptor in myocardium. METHODS: CHF was induced by left coronary artery ligation for 6 weeks. CHF rats were treated with Dex 50 mg.kg/d. Hemodynamics, histology, reactive oxygen species (ROS)-related parameters, and leptin concentrations in serum were measured. The mRNA expression of matrix metalloproteinases (MMP)2/9, tissue inhibitor of metalloproteinases (TIMP)1/2, tumor necrosis factor (TNF)-alpha, and OB-Rb were measured by RT-PCR. RESULTS: In the CHF rats, hemodynamic functions were deteriorated, which was accompanied with myocardium remodeling and histological changes. CHF rats showed hyperleptinemia and excessive ROS in the serum, and the upregulation of MMP-2/9, TNF-alpha, and leptin receptor mRNA and downregulation of TIMP-1/2 mRNA in the myocardium compared with the sham operation group. Dex treatment significantly ameliorated CHF in association with the reversion of the abnormalities of MMP-2/9, TIMP-1/2, TNF-alpha, and ROS. But Dex had no influence on the hyperleptinemia and the upregulated leptin and its receptor in the myocardium during CHF. CONCLUSION: Dex improves CHF by inhibiting TNF-alpha, MMP-2, MMP-9, and ROS. Dex had no effects on upregulated leptin and its receptor expression and hyperleptinemia induced by CHF.


Assuntos
Dexametasona/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Leptina/sangue , Animais , Doença Crônica , Dexametasona/uso terapêutico , Regulação para Baixo , Insuficiência Cardíaca/sangue , Masculino , Metaloproteinases da Matriz/genética , Estresse Oxidativo , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Receptores para Leptina/sangue , Fatores de Transcrição STAT/fisiologia , Inibidores Teciduais de Metaloproteinases/genética , Fator de Necrose Tumoral alfa/genética , Remodelação Ventricular/efeitos dos fármacos
12.
Fa Yi Xue Za Zhi ; 20(3): 160-1, 2004.
Artigo em Chinês | MEDLINE | ID: mdl-15495810

RESUMO

OBJECTIVE: To study genetic polymorphism of D7S2846, D19S400 and D18S535 in Han population in Wenzhou. METHODS: DNA was extracted with chelex-100 method from EDTA-blood samples of 194 unrelated individuals in Wenzhou and amplified with PCR technique. The PCR products were analyzed by PAG vertical electrophoresis and silver-stain. RESULTS: 6 alleles and 15 genotypes of D7S2846, 10 alleles and 36 genotypes of D19S400, 8 alleles and 26 genotypes of D18S535 was observed. The heterozygosities of the three loci are 0.644, 0.724 and 0.772; The power of discriminating are 0.854, 0.940 and 0.938. CONCLUSION: The heterozygosities of the three loci are high and the frequencies was in accordance with Hardy-Weinberg equilibrium (P>0.05), so the three loci can be used in forensic medicine and in other genetic researches.


Assuntos
Alelos , Polimorfismo Genético , Sequências de Repetição em Tandem , China/etnologia , DNA/isolamento & purificação , Frequência do Gene , Genótipo , Humanos , Reação em Cadeia da Polimerase
13.
Fa Yi Xue Za Zhi ; 20(2): 85-7, 2004.
Artigo em Chinês | MEDLINE | ID: mdl-15311521

RESUMO

OBJECTIVE: To investigate the polymorphism and forensic efficiency values of STR loci D12S391/D18S865 METHODS: Population studies on D12S391 and D18S865 were carried out in a sample of 454 unrelated Wenzhou Han individuals using PCR followed by PAGE and silver stain detection. RESULTS: 11/7 alleles and 50/21 genotypes of D12S391/D18S865 were respectively observed among the 454 unrelated individuals. The genotype frequency matched the Hardy-Weinberg equilibrium, The heterozygotes (H) in D12S391/D18S865 were 0.7974/0.7379, Power of Exclusion were 0.9566/0.9077, polymorphism information content (PIC) were 0.8260/0.7279 respectively. CONCLUSION: D12S391 and D18S865 were high polymorphic loci and the frequencies were in accordance with Hardy-Weinberg equilibrium (P>0.5), so the two loci can be used in forensic medicine and in other genetic research areas.


Assuntos
Alelos , Polimorfismo Genético , Sequências de Repetição em Tandem , China/etnologia , DNA/sangue , DNA/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Medicina Legal , Frequência do Gene , Genótipo , Humanos , Reação em Cadeia da Polimerase
14.
Zhonghua Nei Ke Za Zhi ; 42(9): 628-31, 2003 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-14514391

RESUMO

OBJECTIVE: To investigate the mRNA and protein expressions of soluble guanylate cyclase (sGC) and its enzyme activity in pulmonary hypertension rat model which was reproduced by hypoxia and hypercapnia. METHODS: Male Sprague-Dawley rats were randomly divided into hypoxic and hypercapnic group (HH group) and control group (C group). The protein expressions of sGC alpha(1) and sGC beta(1) subunits in medial and small pulmonary arteries was measured by immunohistochemistry method with a polycolonal antibody. The mRNA expression of sGC alpha(1) subunit of lung tissue was detected by in situ hybridization using sGC oligonuclear probe. Basal sGC enzyme activity and sodium nitroprusside (SNP)-stimulated sGC activity in lung homogenates were assayed with enzyme kinetic analysis. RESULTS: The mean pulmonary artery pressure (mPAP), the ratio of right ventricle/left ventricle + septum [RV/(LV + S)] and the ratio of right ventricle/body weight (RV/BW) were significantly higher in HH group than those in C group. The protein expressions of sGC alpha(1) and sGC beta(1) subunits and mRNA expressions of sGC alpha(1) subunit were significantly decreased in the small and medium pulmonary arteries in HH group as compared with those in C group (P < 0.01). Basal sGC enzyme activity in HH group (32.03 +/- 7.17 pmol cGMP synthesized.mg protein(-1).min(-1)) was significantly lower than that in C group (114.76 +/- 18.37 pmol cGMP synthesized.mg protein(-1).min(-1), P < 0.01). The SNP significantly increased the sGC enzyme activity but the SNP-stimulated sGC enzyme activity of lung homogenates in HH group was significantly lower than that in C group (P < 0.01). CONCLUSIONS: The mRNA and protein expressions of sGC subunits and their enzyme activities in lung tissue of pulmonary hypertension rat model were reduced.


Assuntos
Guanilato Ciclase/análise , Hipercapnia/enzimologia , Hipertensão Pulmonar/enzimologia , Hipóxia/enzimologia , Animais , Guanilato Ciclase/genética , Imuno-Histoquímica , Masculino , Óxido Nítrico/fisiologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
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