RESUMO
After injection of 20 mg/kg peroxiredoxin 6 to male Kv:SHK mice 15 min before X-ray irradiation in the range of lethal doses (7-10 Gy), the mice remained alive for 30 days, whereas the mortality of the control animals was 100%. In the irradiated animals, peroxiredoxin 6 decreased the severity of radiation-induced leucopenia, granulocytopenia, and thrombocytopenia, increased the number of blood corpuscles, and prevented the mass death of epithelial cells and the destruction of the small intestine. Thus, peroxiredoxin 6 can be regarded as a prophylactic radioprotective agent.
Assuntos
Peroxirredoxina VI/farmacologia , Lesões Experimentais por Radiação/tratamento farmacológico , Protetores contra Radiação/farmacologia , Animais , Injeções Intravenosas , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , Intestino Delgado/efeitos da radiação , Masculino , Camundongos , Lesões Experimentais por Radiação/patologia , Índice de Gravidade de Doença , Análise de Sobrevida , Raios XRESUMO
It is shown that endothelial cells from human umbilical vein have a reduced activity and gene expression of the "classic" antioxidant enzymes (Cu,Zn-superoxide dismutase, catalase, and Se-containing glutathione peroxidase). At the same time, a high expression level of peroxiredoxin genes was identified in the same endothelial cells, which obviously indicates the predominant involvement of these enzymes in protecting the endothelium from the damaging effect of free radical peroxidation.
Assuntos
Catalase/metabolismo , Células Endoteliais/enzimologia , Eritrócitos/enzimologia , Glutationa Peroxidase/metabolismo , Superóxido Dismutase-1/metabolismo , Veias Umbilicais/enzimologia , Células Cultivadas , Expressão Gênica , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Veias Umbilicais/citologiaRESUMO
BACKGROUND: Strong oxidative stress starting in the epithelium upon restoration of blood cell circulation is a major cause of necrosis of the intestinal epithelium in ischemia/reperfusion-induced damage. AIM: The purpose of this study was to investigate the tissue-protective effect of exogenous peroxiredoxin 6 (Prx6) in ischemia/reperfusion-induced damage of small intestine. METHODS: The research was carried out using a model of acute superior mesenteric artery occlusion in Wistar male rats. Exogenous Prx6 was administrated intravenously 15 min prior to small intestine ischemia. The distribution of endogenous Prx6 in the small intestine was determined by immunohistochemical analysis. The expression level of antioxidant enzymes was evaluated by RT-PCR in real time. RESULTS: Exogenous Prx6 injected to animals intravenously was detected in blood vessel lumens, and its diffuse distribution was subsequently confirmed in the intestinal epithelium. Expression analysis of genes coding for major antioxidant enzymes demonstrated a significant activation of SOD 1, SOD 3, Prx6, GPx2, GPx7 expression during I/R-induced damage of the small intestine. Injection of exogenous Prx6 prior to induced ischemia resulted in minimization of oxidative injury by reducing necrosis and apoptosis, by normalization of gene activity of antioxidant enzyme. It eventually led to a reduction of epithelium destruction in the small intestine. By contrast, administration of a purified mutant form of Prx6 (Prx6C47S) without peroxidase activity had no protective effect. CONCLUSION: The application of exogenous Prx6 enables normalization of the antioxidant status of the small intestine and reduction of cell destruction upon I/R-induced organ damage.
Assuntos
Intestino Delgado/patologia , Peroxirredoxina VI/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Antioxidantes/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Ensaio de Imunoadsorção Enzimática , Enzimas/genética , Enzimas/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Intestino Delgado/metabolismo , Masculino , Mutação , Estresse Oxidativo , Peroxirredoxina VI/administração & dosagem , Peroxirredoxina VI/farmacocinética , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio , Traumatismo por Reperfusão/metabolismoRESUMO
The content and distribution of myelin basic protein (MBP) isoforms (17 and 21.5 kDa) as well as 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase) were determined in mitochondrial fractions (myelin fraction, synaptic and nonsynaptic mitochondria) obtained after separation of brain mitochondria by Percoll density gradient. All the fractions could accumulate calcium, maintain membrane potential, and initiate the opening of the permeability transition pore (mPTP) in response to calcium overloading. Native mitochondria and structural contacts between membranes of myelin and mitochondria were found in the myelin fraction associated with brain mitochondria. Using Western blot, it was shown that addition of myelin fraction associated with brain mitochondria to the suspension of liver mitochondria can lead to binding of CNPase and MBP, present in the fraction with liver mitochondria under the conditions of both closed and opened mPTP. However, induction of mPTP opening in liver mitochondria was prevented in the presence of myelin fraction associated with brain mitochondria (Ca2+ release rate was decreased 1.5-fold, calcium retention time was doubled, and swelling amplitude was 2.8-fold reduced). These results indicate possible protective properties of MBP and CNPase.
