The quantification of ADAMTS4 and 8 expression and selection of reference genes for quantitative real-time PCR analysis in myocardial infarction

IntroductionADAMTS4 and ADAMTS8 are proteases involved in ECM proteolysis and antiangiogenesis, but little is known about their expression and function in myocardial infarction (MI). We examined ADAMTS4 and ADAMTS8 expression in a rat MI model by quantitative real-time polymerase chain reaction (qPCR) and enzyme linked immunosorbent assay (ELISA). The expressions of glyseraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin (ACTB), acidic ribosomal phosphoprotein P0 (ARBP), and ribosomal protein L13A (RPL13A) were examined in order to validate the appropriate housekeeping genes after MI.MethodsMale Wistar rats were subjected to MI, and infarcted myocardial tissue was collected at 3, 6, 12, 24 h, 3, 7, 14 and 21 days after MI. ADAMTS4, ADAMTS8, and the four housekeeping genes were quantified using qPCR and the expression stability of the four housekeeping genes was investigated using GeNorm software. The protein levels of ADAMTS4 were detected using ELISA kits.ResultsThe M values of GAPDH, ACTB, ARBP and RPL13A were 0.721, 1.2, 0.812 and 0.812 respectively. GAPDH and ARBP were ranked the most stable genes. ADAMTS4 mRNA increased at 3 h after MI, peaked at 6 h, then decreased rapidly. ADAMTS8 mRNA increased at 6 h, peaked at 24 h, remained high at 3 d, then decreased gradually. The protein levels of ADAMTS4 were significantly increased at 6 h, 12 h, 24 h and 3 d after MI.ConclusionThe results suggest that GAPDH and ARBP are two appropriate housekeeping genes for the rat MI model. Both ADAMTS4 and ADAMTS8 mRNA levels and ADAMTS4 protein level increased, but they exhibited different expression profiles.