LDL and cAMP cooperate to regulate the functional expression of the LRP in rat ovarian granulosa cells
| Autor: | Allen D. Cooper, Eve Reaven, Salman Azhar, Loren G. Fong, Yoshio Fujioka, Wen-Jun Shen, Satyanarayana Medicherla |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: |
medicine.medical_specialty
Very low-density lipoprotein Ovarian Granulosa Cell Granulosa cell adenosine 3′ 5′-cyclic monophosphate QD415-436 Biology Biochemistry Article Rats Sprague-Dawley chemistry.chemical_compound Endocrinology Chylomicron remnant Internal medicine medicine Cyclic AMP Animals Humans alpha-Macroglobulins Scavenger receptor Receptor Cells Cultured Granulosa Cells Ovary Cell Biology Scavenger Receptors Class B Rats Lipoproteins LDL low density lipoprotein receptor-related protein chemistry Gene Expression Regulation Receptors LDL Low-density lipoprotein LDL receptor Female Steroids lipids (amino acids peptides and proteins) low density lipoprotein |
| Zdroj: | Journal of Lipid Research, Vol 47, Iss 11, Pp 2538-2550 (2006) |
| ISSN: | 0022-2275 |
| Popis: | Rat ovarian granulosa rely heavily on lipoprotein-derived cholesterol for steroidogenesis, which is principally supplied by the LDL receptor- and scavenger receptor class B type I (SR-BI)-mediated pathways. In this study, we characterized the hormonal and cholesterol regulation of another member of the LDL receptor superfamily, low density lipoprotein receptor-related protein (LRP), and its role in granulosa cell steroidogenesis. Coincubation of cultured granulosa cells with LDL and N6,O2'-dibutyryl adenosine 3',5'-cyclic monophosphate (Bt2cAMP) greatly increased the mRNA/protein levels of LRP. Bt2cAMP and Bt2cAMP plus human hLDL also enhanced SR-BI mRNA levels. However, there was no change in the expression of receptor-associated protein, a chaperone for LRP, or another lipoprotein receptor, LRP8/apoER2, in response to Bt2cAMP plus hLDL, whereas the mRNA expression of LDL receptor was reduced significantly. The induced LRP was fully functional, mediating increased uptake of its ligand, alpha2-macroglobulin. The level of binding of another LRP ligand, chylomicron remnants, did not increase, although the extent of remnant degradation that could be attributed to the LRP doubled in cells with increased levels of LRP. The addition of lipoprotein-type LRP ligands such as chylomicron remnants and VLDL to the incubation medium significantly increased the progestin production under both basal and stimulated conditions. In summary, our studies demonstrate a role for LRP in lipoprotein-supported ovarian granulosa cell steroidogenesis. |
| Databáze: | OpenAIRE |
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