RESUMO
The hsp70 and hsp90 expression patterns and catalase (CAT) activity in the freshwater planaria Dugesia japonica exposed to cadmium (Cd) under laboratory conditions were investigated. Planaria were exposed to a range of Cd concentrations (0-150 µg Cd/L) for 24 h. The expression levels of hsp70 and hsp90 were determined by relative quantitative real-time polymerase chain reaction. Within the overall dose range in the experiment, the expression level of hsp70 and the activity of CAT in D. japonica were altered significantly. Hsp70 was induced in D. japonica upon Cd exposure concentrations as low as 9.375 µg Cd/L. No significant effect on the expression level of hsp90 was observed. Our findings demonstrated that stress gene hsp70, but not hsp90, was responsive to Cd contamination in D. japonica CAT activity was significantly induced at concentrations of 18.75, 37.5, and 75 µg Cd/L after 24-h exposure. We recommend that the use of hsp70 as a biomarker should be complemented by evidence of changes in other parameters, such as CAT activity, in D. japonica.
Assuntos
Cádmio/toxicidade , Catalase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Helminto/metabolismo , Planárias/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Catalase/química , China , Proteínas de Choque Térmico HSP70/agonistas , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Helminto/agonistas , Proteínas de Helminto/genética , Concentração Osmolar , Estresse Oxidativo/efeitos dos fármacos , Planárias/enzimologia , Planárias/isolamento & purificação , Planárias/metabolismo , RNA de Helmintos/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVES: To isolate the cardiogenic fraction, which can enhance cardiogenic differentiation of bone marrow-derived mesenchymal stem cells (MSC) from Geum japonicum. The therapeutic effect of the isolated cardiogenic fraction was further tested in a rat myocardial infarction (MI) model. METHOD: Bioassay guided fractionation method was used for the isolation of the cardiogenic fraction, named as heart repair fraction (HRF). MI was induced by a permanent ligation of left anterior descending coronary artery. The rats exhibiting similarly decreased values of left ventricle ejection fraction (LVEF) and fraction shortening (LVFS) were used. The rats in test group (n = 10) were subject to HRF treatment (20 mg×kg(-1)×d(-1)) through gastric gavage daily for 4 weeks. Water alone (2 ml/d) was given through gastric gavage to rats in the control group (n = 10). The cardiac function was assessed by echocardiography at different time points. Masson trichrome staining was used for evaluation of the infarct size. Morphological and immunohistochemical studies were performed to investigate the HRF mediated myocardial regeneration. RESULTS: LVEF (66.2% ± 6.9%) and LVFS (46.8% ± 5.8%) were significantly increased two weeks post HRF treatment compared with the values (LVEF: 55.7% ± 6.0% and LVFS: 36.4% ± 5.2%) in control rats (all P < 0.01). The improved heart function was further restored 4 weeks post HRF treatment (P < 0.01). Furthermore, the treatment of acute MI with this HRF significantly reduced the infarct size (19.0% ± 6.1%) compared with that (31.1% ± 8.6%) in control rats (P < 0.01). Substantial regeneration of cardiomyocytes in infarcted region of the HRF treated heart was also observed that replaced a considerable part of the infarcted heart tissues resulting in remarkable reduction of the infarct size. CONCLUSION: The properties of this HRF isolated from Geum japonicum in stimulating substantial regeneration of myocardium in infarct region with consequently improved cardiac function appear to be new and represent a new approach for the treatment of MI.
