何奕倫2006-07-262018-07-112006-07-262018-07-112005http://ntur.lib.ntu.edu.tw//handle/246246/23707Background – Mutations of cardiac troponin C (cTnC) can cause dilated cardiomyopathy in humans. We attempted to generate a zebrafish transgenic line that enables us to produce the antinsense RNA strand of cTnC after induction as a new animal model for studying dilated cardiomyopathy. Methods and Results – We constructed plasmids that the reverse tetracycline–controlled transactivator (rtTA) was driven by the cardiac myosin light chain 2 promoter. This heart-specific rtTA bound another bidirectional promoter to express the green fluorescence protein (GFP) reporter gene and to transcribe the antisense RNA of cTnC in the presence of doxycycline (Dox). After microinjection of these constructs into one-cell fertilized eggs, we cultured, screened, and generated a transgenic line of zebrafish (CA17) which enabled us to express GFP and to conditionally produce the antisense RNA of cTnC in heart after induction. When 12-h postfertilization (hpf) embryos of F2 derived from CA17 were given Dox (10 µg/ml), the expression of endogenous cTnC mRNA was not affected until 6 days postfertilization (dpf). The heart rates of the embryos in CA17 were significantly slower than those of embryos in the control T03 transgenic line (only expressing the heart-specific GFP) at 6 dpf (150±10 vs. 194±11 beats/min, p < 0.01) and 12 dpf (128±12 vs. 168±8 beats/min, p < 0.01). Moreover, the various values of cardiac chambers measured in the induced F2 embryos from CA17 were significantly greater than those of T03 embryos; while the ventricular ejection fraction of CA17 was lower than that of the T03 both at 6 dpf (44%±4% vs. 50%±3%, p < 0.01) and at 12 dpf (39%±5% vs. 52%±4%, p <0.01). In addition, asynchronized atrial and ventricular contractions were noted in a few (1.3%) F2 embryos from the induced CA17 transgenic fish. The mortality rate of F2 adult fish of the CA17 group was significantly higher (30% vs. 0%, p < 0.001) than that of F2 adults of the T03 group after Dox induction. Conclusions – Using conditional expression of antisense RNA of zebrafish cTnC, we have created a new animal model with phenotypes simulating dilated cardiomyopathy.application/pdf134410 bytesapplication/pdfzh-TW國立臺灣大學醫學院內科ZebrafishCardiac troponin CAntisense RNADilated cardiomyopathy[SDGs]SDG3reporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/23707/1/932314B002219.pdf