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Objective To screen cardiac-specific short-acting peptides on live myocardial slices using phage display technology,so as to improve the targeted delivery efficiency of drugs in myocardium and provide effective candidates for the targeted therapy of Duchenne muscular dystrophy (DMD) and other cardiomyopathies.Methods Myocardial tissue slices were prepared and cultured in vitro.The protein activities of the tissues were examined by immunohistochemistry.The in vitro cultured myocardial tissue slices were co-incubated with phage library (1×1012 pfu),and the phages that bound to the myocardium were recovered and amplified.The cardiac-specific targeting phages were identified by five rounds of in vitro phage biopanning.The candidate phage-related insertion sequence was sequenced,and the in vivo tissue distribution of the highly enriched phages was verified.Results A platform for in vitro culturing of live myocardial slices was established.Myocardial slices with good biological activity were obtained.After 48 hours of culturing,the normal expression and localization of Dystrophin protein were detected.Using phage library,candidate phages were screened after five rounds of phage biopanning.The results of the sequencing analyses and in vivo tissue distribution verification indicated that the selected candidate phages showed significant enrichment in myocardium and skeletal muscle,and showed low levels in liver and kidney tissues.Conclusions The candidate phages showed higher binding efficiency in both myocardium and skeletal muscle,indicating that the candidate peptides had myocardial targeting property,and that can provide a new method for myocardial targeting therapy of DMD.
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Objective To explore effects of heroin and ephedrine on the histological structure and ChAT activity of hypothalamus and hippocampus of filial mice. Expression of Bcl-2 associated X protein(Bax protein) and keratinocyte growth factor(KGF) of hypothalamus and hippocampus were measured. Methods One hundred and eight filial mice were given intraperitoneal injection of heroin and ephedrine by gradually increase of doses, apoptosis and expression of Bax protein and KGF of hypothalamus and hippocampus were observed by Giemsa staining and immunohistochemistry, and the ChAT activity was detected by colorimetry. Results After administration of heroin and ephedrine at 5,10,15,20 days, the number of apoptotic cells and expression of Bax protein and KGF of hypothalamus and hippocampus were significantly increased and ChAT activity was lower than those of the control group(P<0.05 or P<0.01). There were differences between heroin group and the ephedrine group in the above-mentioned four indexes (P<0.05 or P<0.01). The number of apoptotic cells and Bax protein and KGF immunopositive neurons of hypothalamus and hippocampus increased by the increase in dose of heroin and ephedrine. Conclusions Heroin and ephedrine had great effect on the histological structure and ChAT activity of hypothalamus and hippocampus of filial mice, and this effects would be related to the cell apoptosis of hypothalamus and hippocampus.