The c-Abl expression in uterine epithelium during the mouse estrus cycle

The epithelial cells of the mouse endometrium comprises the recurring physiologic changes such as proliferation and apoptosis induced by the reproductive hormones throughout the estrus cycle. The c-Abl is a protein tyrosine kinase, localized in the different cellular compartments such as nucleus, cytoplasm, mitochondria, and endoplasmic reticulum, interacts with different cellular proteins, including signaling adaptors, kinases, phosphatases, cell-cycle regulators, transcription factors and cytoskeletal proteins. Our hypothesis is that the c-Abl expression in the mouse uterine epithelium shows cyclic changes during the estrus cycle that is involved in regulation of the endometrial epithelial cells. The regulation of c-Abl gene and protein expression in the uterus of intact animals in the different cycle phases was investigated using immunohistochemistry, western blot and semi-quantitative RT-PCR. The immunohistochemistry results revealed that the luminal and the glandular epithelium (LE) and (GE), respectively, showed gradually increase in the expression of c-Abl from the proestrus (P) to the metestrus and followed by a decrease in the diestrus (D). c-Abl immunoreactivity was detected in the both LE and GE cells, especially the LE showed diminished the c-Abl protein expression on the D phase and the minimal value was detected on the P day. The c-Abl protein level in the LE was increased during the M, presenting a high correlation with the hormonal level of this cell type. The result of c-Abl RT-PCR analysis was compatible with pattern of c-Abl protein expression. In conclusion, the stage-specific protein pattern of the mammalian c-Abl tyrosine kinase presented a good correlation with the mouse estrus cycle and may have a regulative function during the uterine remodeling.