植入微囊化hANP cDNA转染细胞治疗大鼠高血压的观察

Study on Treatment of Hypertension in Rats by Implantation of Encapsulated hANP cDNA Transfected Cells

目的研究植入微囊化的人类心房肽(hANP)cDNA转染细胞对高血压大鼠的治疗效果,为临床应用基因工程细胞治疗高血压提供新方法。方法将转染有hANPcDNA的CHO细胞包被在具有免疫隔离作用的聚己内酯(PCL)管内形成微囊化基因转染细胞,其后移植至二肾一夹(2K1C)高血压大鼠腹腔内,检测微囊植入对高血压大鼠的血压及多项生理生化指标的影响,并用放射免疫分析法(RIA)检测血浆hANP水平,用免疫组化结合图像分析法半定量检测肾脏心房肽A型受体(NPRA)的表达。结果微囊化的hANPcDNA转染细胞移植10d后,血浆hANP水平显著升高;移植30d后高血压大鼠的血压明显降低,而尿量、尿钠排出量(USO)和尿cGMP明显增加;移植45d后肾小球滤过率(GFR)和肾血流量(RBF)明显增加,同时高血压大鼠肾脏NPRA的表达下调被抑制。结论植入的微囊化hANPcDNA转染细胞能产生和向囊外排出hANP,引起明显的利尿利钠和降血压效应;本研究结果为高血压的心房肽基因治疗提供了新途径。

Objective To study the therapeutic effects of implanting encapsulated human atrial natriuretic peptide (hANP) gene transfected cells on hypertensive rats so as to provide a new approach to hypertension. Method hANP cDNA transfected Chinese hamster ovary (CHO) cells were encapsulated in non-antigenic biocompatible polycaprolactone (PCL) tubes and the PCL tubes were implanted into two-kidney, one-clip (2K1C) hypertensive rats intraperitoneally. The effects of implanting encapsulated hANP gene transfected cells on some physiological and chemical parameters were observed. The concentration of plasma hANP was measured by radioimmunoassay (RIA) and the expression of renal A-type natriuretic peptide receptor (NPR-A) was detected by immunohistochemical method combined with image analysis semi-quantitatively. Result The level of hANP in plasma was significantly elevated 10 d after implantation of encapsulated hANP cDNA transfected cells. Blood pressure decreased significantly, whereas urine volume, urinary sodium output (USO)and urinary cGMP content increased significantly 30 d after implantation in CHO-hANP group hypertensive rats as compared with those in CHO-group hypertensive rats. Both glomerular filtration rate(GFR) and renal blood flow(RBF) increased significantly 45 d after implantation. Meanwhile, the down-regulation of renal NPR-A in 2K1C rats was suppressed. Conclusion Diuresis, natriuresis and reduction of blood pressure are found due to hANP produced and secreted by the implanted gene transfected cells. It provides a new and practicable gene therapeutic approach to hypertension.