Expression, localization, and functional model of cholesterol transporters in lactating and nonlactating mammary tissues of murine, bovine, and human origin.

Members of the ATP-binding cassette (ABC) transporters play a pivotal role in cellular lipid efflux. To identify candidate cholesterol transporters implicated in lipid homeostasis and mammary gland (MG) physiology, we compared expression and localization of ABCA1, ABCG1, and ABCA7 and their regulatory genes in mammary tissues of different species during the pregnancy-lactation cycle. Murine and bovine mammary glands (MGs) were investigated during different functional stages.

Lactoferrin (Lf): Retinoid interactions in the mammary glands of transgenic mice overexpressing human Lf.

Induction of protein expression in a tissue-specific manner by gene transfer over-expression techniques has been one means to define the function of a protein in a biological paradigm. Studies with retinoid reporter constructs transfected in mammary cell lines suggests that lactoferrin (Lf) affects retinoid signaling pathways and alters apoptosis. We tested the effects and interactions of over-expressed mammary-specific human lactoferrin (hLf) and dietary retinol palmitate on lactation and mammary gland development in mice.

Cloning and characterization of a novel zinc finger protein (rZFP96) in the rat corpus luteum.

The corpus luteum (CL) is a temporary organ involved in the maintenance of pregnancy. In the course of its life-cycle, the CL undergoes two distinct and consecutive processes for its inevitable removal through apoptosis: functional and structural luteolysis. We isolated a gene encoding for a novel rat zinc finger protein (ZFP), named rat ZFP96 (rZFP96) from an ovarian lambda cDNA library.

Expression and localization of secreted frizzled-related protein-4 in the rodent ovary: evidence for selective up-regulation in luteinized granulosa cells.

Secreted frizzled-related protein-4 (sFRP-4) belongs to a family of soluble proteins that have a Frizzled-like cysteine-rich domain and function as modulators of Wnt-Frizzled (Fz) signals. As several Wnts and Fz are expressed at defined stages of follicular development in rodent ovaries, these studies were undertaken to evaluate the hormone-regulated expression and localization of sFRP-4. In the mouse ovary, the expression of sFRP-4 mRNA was up-regulated in granulosa cells of large antral follicles after human chorionic gonadotropin administration and was also elevated in corpora lutea, as determined by RT-PCR and in situ hybridization analyses.

Regulated expression of inhibitor of apoptosis protein 3 in the rat corpus luteum.

We sought to investigate the role inhibitor of apoptosis proteins (IAPs) play in the life cycle of the corpus luteum (CL) of the rat. We isolated two clones with amino acid homology to rat IAP2 (BIRC 3) and three to rat IAP3 (rIAP3; BIRC 4). The expression of rIAP3 mRNA was examined in the rat CL during and after pregnancy, in Day 8 pregnant rats after 24-h treatment of gonadotropin-releasing hormone-agonist (GnRH-Ag), and in a CL organ culture model of spontaneous apoptosis in the absence of tropic support with and without superoxide dismutase.