Expression and function of a scavenger lipoprotein pathway in porcine luteal cells

• Published in: Biology of reproduction 1997-01, Vol.56 (1), p.221-228
• Main Author: Brannian, J.D. (University of South Dakota Health Sciences Center, Sioux Falls, SD.)
• Format: Article
• Language: English
• Subjects: Acetylation; Animals; Biological and medical sciences; Cells, Cultured; CELLULE; CELULAS; CERDO; CHIMIORECEPTEUR; CICLO ESTRAL; CORPS JAUNE; Corpus Luteum - metabolism; CUERPO LUTEO; CULTIVO DE CELULAS; CULTURE DE CELLULE; CYCLE OESTRAL; Female; Flow Cytometry; Fluorescent Dyes; Free Radical Scavengers; Fundamental and applied biological sciences. Psychology; Gene Expression; Lipid Peroxidation; LIPOPROTEINAS; LIPOPROTEINE; Lipoproteins, LDL - metabolism; Mammalian female genital system; METABOLISME DES STEROIDES; METABOLISMO DE ESTEROIDES; Morphology. Physiology; PORCIN; PROGESTERONA; PROGESTERONE; Progesterone - biosynthesis; QUIMIORECEPTORES; Swine; Vertebrates: reproduction
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod56.1.221

A pathway(s) for uptake of modified (e.g., acetylated, oxidized) low-density lipoprotein (LDL) moieties has been recently discovered on luteal cells of certain species. The expression and function of this pathway during the life span of the corpus luteum (CL) have not been investigated. Aims of the present study were the following: 1) to determine whether porcine small and large luteal cells take up modified LDL; if so, 2) to compare uptake of native and modified LDL by luteal cell subpopulations during the luteal life span and 3) to compare effects of native and modified LDL on luteal steroidogenesis during the estrous cycle. Collagenase-dispersed luteal cells were prepared from porcine ovaries at various stages of the estrous cycle: early (E, Days 4-6), mid (M, Days 8-10), mid-late (ML, Day 13-14), or late (L, Day 16-17) (estrus = Day 0). Cells were incubated with fluorescent-tagged LDL (Dil-LDL; 0-10 micrograms/ml) or acetylated LDL (Dil-AC-LDL; 0-10 micrograms/ml). Fluorescence was analyzed by multiparameter flow cytometry in each of three subpopulations of cells: small (SLC) and large (LLC) luteal cells and nonsteroidogenic cells. The percentage of LLC taking up Dil-LDL remained relatively constant (65-75%) from E to ML cycle and then declined (13.3 +/- 4.1%; p 0.05); these findings were consistent with previous data. In contrast, the percentage of LLC taking up Dil-AC-LDL gradually increased from E (29.8 +/- 8.5%) to ML (68.3 +/- 5.9%) stage and then declined (17.1 +/- 2.3%, p 0.05). Similarly, Dil-LDL uptake by SLC was relatively constant (15-20%) from E to M cycle, declining to 2.9 +/- 0.5% at L cycle. Dil-AC-LDL uptake by SLC progressively increased from E (5.4 +/- 2.6%) to ML (24.3 +/- 6.9%) and then fell somewhat (12.9 +/- 6.7%) in L cycle. Few ( 2%) nonsteroidogenic cells labeled for Dil-LDL at all stages, whereas Dil-AC-LDL uptake by nonsteroidogenic cells was similar to that by SLC