[Differentially expressed transcription factors in the cardiac outflow tract tissue of connexin43 knockout mice].

OBJECTIVE:To investigate the changes in the expression of cardiac transcription factors in the cardiac outflow tract (OFT) tissues in the connexin43 knockout homozygotes (Cx43 KO), connexin43 heterozygotes, and connexin43 wild-type mice (Cx43 WT). METHODS:The cDNA was retrotranscribed from the RNA extracted from the OFT tissues of 6 Cx43 KO, 6 Cx43 WT, and 6 Cx43 heterozygotes genotyped by PCR method on the embryonic day (ED) 13.5 and ED 14.5. The biotin-labeled cRNA derived from the transcription of cDNA was fragmented as probes. The probes were hybridized with Affymetrix Mouse Genome 430 2.0 Array. Gene Array Scanner was used to screen the signals of hybridization and detect the expression of genes. The mRNA expression levels of 3 cardiac transcription factors: Sox11, Foxp1, and Tbx20 were measured by real time quantitative RT-PCR. RESULTS:The ratios of the expression of the 6 genes, all cardiac transcription factors: Gata4, Mef2C, Sox4, Sox11, Foxp1, and Tbx20 between the Cx43 KO and Cx43 WT groups were 1:1.41, 1:2.30, 1:3.25, 1:0.71, 1:0.66, and 1:0.54. The expression levels of Sox11 and Foxp1 on ED13.5 in the Cx43 K group were 4.76 +/- 0.19 and 5.08 +/- 0.28 respectively, both significantly lower than those of the Cx43 WT group (5.34 +/- 0.25 and 5.64 +/- 0.15 respectively, both P < 0.01), and expression level of Tbx20 on ED 13.5 in the Cx43 K group was 7.18 +/- 0.16, not significantly different from that of the Cx43 WT group (7.47 +/- 0.27, P > 0.05). The expression levels of the genes Sox11, Foxp1, Tbx20 on ED 14,5 were 4.71 +/- 0.27, 5.25 +/- 0.31, and 7.05 +/- 0.17 respectively, all significantly lower than those of the Cx43 WT group (5.00 +/- 0.19, 5.77 +/- 0.16,) and 7.43 +/- 0.25, all P < 0.05). The results of the expression of these genes by real time PCR analysis showed an excellent concordance with those indicated by the microarray analysis. CONCLUSION:The cardiac transcription factors such as Sox11, Foxp1, and Tbx20 that are differently expressed in the Cx43 KO OFT tissue may be involved in the pathogenesis of the OFT defects.