Expression of B Cell Activating Factor Pathway Genes in Mouse Mammary Gland

Abstract

In our previous study, overexpression of extracellular proteinase inhibitor (Expi) gene accelerated apoptosis of mammary epithelial cells, and induced expression of B cell activating factor (BAFF) gene. In this study, we found induction of BAFFreceptor (BAFF-R) gene expression in the Expi-transfected cells. A proliferation-inducing ligand (APRIL) gene is another TNF family member and the closest known relative of BAFF. We found induction of APRIL gene expression in the Expi-overexpressed apoptotic cells. NF-κB gene was also induced in the Expi-overexpressed cells. Expression patterns of BAFF and APRIL pathway-related genes were examined in in vivo mouse mammary gland at various reproductive stages. Expression levels of BAFF gene were very low at early pregnancy, increased from mid-pregnancy, and peaked at lactation, and thereafter decreased at involution stages of mammary gland. Expression of BAFF-R gene was highly induced in involution stages compared to lactation stages. Thus, expression patterns of BAFF-R gene were correlated to apoptotic status of mammary gland: active apoptosis of mammary epithelial cells occurs at involution stage of mammary gland. Expression levels of NF-κB gene were higher in involution stages compared to lactation stages. We analyzed mRNA levels of bcl-2 family genes from different stages of mammary development. Bcl-2 gene expression was relatively constant during lactation and involution stages. There was a slight increase in bcl-xL gene expression in involution stages compared to lactation state. Bax gene expression was highly induced in involution stage. Our results suggest that signaling pathways activated by both BAFF and ARRIL in mammary gland point towards NF-κB activation which causes upregulation of bax.

2, 4-Thiazolidindion Induced Plasticity of Myoblast (C2C12) and Satellite Cells (Porcine) - A Comparative Study

“…However, it has only recently been demonstrated that adult muscle satellite cells are capable of converting to non-myogenic lineages. Treatment of myogenic satellite cells with rosiglitazone or adipogenic inducers/ciglitizone converts these cells into osteogenic or adipogenic cells (Jin et al, 2006;Kook et al, 2006;Singh et al, 2006;Choi et al, 2007). Though, the differentiation of myoblasts and satellite cells to adipoblast for intramuscular adipogenesis have been reported in mammals (Van Barneveld, 2003;Schoonmaker et al, 2004) but the potential inter-relationship of these cells in differentiating to another lineage have not been put forth.…”