Background: Adenoviral vectors are widely used as gene-transfer vehicles in experimental and clinical studies. Since virus incorporation and transfection efficacy depend to a large extent on the concentration of the coxsackie-and-adenovirus (CAR) receptor on target cells the aim of this study was to quantify the CAR-receptor concentration in various human cardiomyopathies.
Methods: After RNA isolation from myocardial biopsies obtained during surgical procedures, cDNA was generated by reverse transcription. The relative RNA content was analyzed by quantitative PCR using glyceraldehydes-3-phosphate dehydrogenase (GAPDH) as a standard reference. The cardiomyopathies (CM) analyzed were categorized according to their etiology in dilated CM (DCM, n = 28), ischemic CM (ICM, n = 52), CM in mitral valve disease (MVCM, n = 32) and aortic valve disease (AVCM, n = 32). Data were related to non-cardiomyopathic tissue from donor hearts (non-CM, n = 64).
Results: Compared with non-CM hearts DCM showed a 34-fold (+/-5.4) increase in CAR mRNA concentration, in ICM CAR mRNA was elevated by a factor of 12 (+/-4.3), in MVCM by 27 (+/-7) and AVCM by factor 47 (+/-9.3) (ANOVA p < 0.001). Compared with the expression in rat hearts CAR levels were found to be similar to those in human ICM.
Conclusions: These results show that cardiomyopathies associated with heart failure transcribe substantially higher levels - on average by a factor of 30 - of CAR-mRNA than non-failing control hearts. Myocardial gene transfer using adenoviral vectors should therefore be facilitated in human cardiomyopathies and may present a promising approach for therapeutic interventions.
Copyright 2003 John Wiley & Sons, Ltd.