Expression of SOLD1 in bovine trophoblast cell lines

抄録

Secreted protein of Ly-6 domain 1 (SOLD1) is a novel member of Ly-6 Superfamily was detected in the extracellular matrix of the mesenchyme in placental cotyledonary villi and was suggested to be involved in the construction of the placenta, however the physiological function of SOLD1 is still obscure. In the present study, the reverse transcription polymerase chain reaction (RT-PCR) analysis reflected that SOLD1 mRNA was strongly expressed in the fetal membranes on day 35 of gestation, while at the same time weakly expressed in the endometrial tissues. We further examined the expression of SOLD1 mRNA and protein using trophoblast cell lines; 13 trophoblast cell lines (BT-A∼ L and BT-1). Total RNA was extracted from all cell lines, then cDNA was synthesized for quantitative real time RT-PCR. The highest expression of SOLD1 was found in BT-E, while the lowest expression was in BT-C. These expression intensities were weak in comparison with fetal membranes. Immunocytochemical analysis was performed using anti-bSOLD1 antibody, SOLD1 protein positive cells were detected in BT-E. In Western blotting analysis, SOLD1 protein was detected in both cell lysate and conditioned medium in all cell lines. Progesterone and Estradiol treatment of BT-E was performed to detect the effect of steroid hormones on SOLD1 mRNA expression. Three different concentrations of progesterone (3 nM, 30 nM and 300 nM) and estradiol (3 pM, 30 pM and 300 pM) had no significant effect on SOLD1 expression. These data suggest that all BT cell lines produce SOLD1 but the regulatory mechanism for the protein expression during early placentation is still unclear; at least these steroid hormones may not be involved.