Rapid detection of CSRP2 mRNA in mouse, rat, and human using LightCycler-based quantitative real-time polymerase chain reaction

Targeted disruption of the mouse Csrp2 gene encoding the cysteine- and glycine-rich LIM domain protein CRP2 result in subtle alteration of cardiac ultrastructure

Background

The cysteine and glycine rich protein 2 (CRP2) encoded by the Csrp2 gene is a LIM domain protein expressed in the vascular system, particularly in smooth muscle cells. It exhibits a bimodal subcellular distribution, accumulating at actin-based filaments in the cytosol and in the nucleus. In order to analyze the function of CRP2 in vivo, we disrupted the Csrp2 gene in mice and analysed the resulting phenotype.

Results

A ~17.3 kbp fragment of the murine Csrp2 gene containing exon 3 through 6 was isolated. Using this construct we confirmed the recently determined chromosomal localization (Chromosome 10, best fit location between markers D10Mit203 proximal and D10Mit150 central). A gene disruption cassette was cloned into exon 4 and a mouse strain lacking functional Csrp2 was generated. Mice lacking CRP2 are viable and fertile and have no obvious deficits in reproduction and survival. However, detailed histological and electron microscopic studies reveal that CRP2-deficient mice have subtle alterations in their cardiac ultrastructure. In these mice, the cardiomyocytes display a slight increase in their thickness, indicating moderate hypertrophy at the cellular level. Although the expression of several intercalated disc-associated proteins such as β-catenin, N-RAP and connexin-43 were not affected in these mice, the distribution of respective proteins was changed within heart tissue.

Conclusion

We conclude that the lack of CRP2 is associated with alterations in cardiomyocyte thickness and hypertrophy.

Caffeine suppresses the expression of the Bcl-2 mRNA in BeWo cell culture and rat placenta

Chronic caffeine exposure during pregnancy has an effect on fetal growth; however, the adverse effects of caffeine on embryogenesis are not well understood and controversial. We used cDNA microarray technology to determine whether caffeine alters gene expressions in a human cytotrophoblast-like cell line, BeWo. We found that the expression of the B-cell CLL/lymphoma 2 (Bcl-2) gene in BeWo cells was down-regulated by caffeine, suggesting that chronic exposure during the gestational period could exert an influence on embryogenesis. We then focused on the Bcl-2- and Bcl-2-associated X protein gene, Bax, to study the responsive gene expression in BeWo cells as well as placentas of pregnant rats fed a diet supplemented with caffeine (2 mg/100 g body weight) during gestation, and analyzed the gene expressions using LightCycler-based quantitative real-time polymerase chain reaction assays. We found a significantly decreased level of Bcl-2 mRNA expression, which demonstrated the influence of caffeine on placental function.