Recently, the applicant has conducted studies to explore the function of the plasma glycoproteins of the inter-alpha-inhibitor family (inter-alpha-inhibitor; (IalphaI) and pre-alpha-inhibitor (PalphaI) in the processes of cumulus expansion and ovulation. Briefly, the LH-nitric oxide-mediated grating of a blood-follicle barrier allows influx of IalphaI and PalphaI from the plasma into the follicle and their subsequent binding to newly synthesized hyaluronic acid (HA) and stabilization of the cumulus extracellular matrix (cECM). Then, catalyzed by a factor produced by membrana glanulosa cells, the light chain (bikunin)-chondroitin sulfate moieties of IalphaI and PalphaI are released and hyaluronic acid becomes covalently bound to the heavy chain(s). This apparent transesterification reaction results in an increase in COC viscosity and elasticity and thus, the """"""""superstabilization"""""""" of the cECM. Meanwhile some of the bikunin becomes incorporated into an, as yet unknown compartment of the COC. They have been keenly interested in the reproductive significance of these reactions and have reasoned that an understanding of these dramatic biochemical and physical transformation within the cECM may hold a key to the function of these molecules in reproductive functions of the COC including: (1) extrusion of the COC from the follicle; (2) integrity of the COC and its viability within the reproductive tract, and (3) fertilizability of the oocyte. Experiments in the present proposal are therefore designed to perturb biochemical and physical properties of COCs related to the synthesis of HA and the incorporation and reactions of IalphaI and PalphaI within the cECM. Experiments described in the following three specific aims are thus designed to analyze the following general hypothesis: Incorporation and covalent binding of IalphaI heavy chains into the cECM is required for function of the cumulus mass in ovulation, oocyte viability and fertilization. Effects of these perturbations will be carefully monitored and controlled by measurements of HA, IalphaI/PalphaI, heavy chain and bikunin levels within the CoC. In addition the elasticity and viscosity of the COC as well as qualities of the zona will be measured. These parameters will then be related to reproductive variables such as follicle rupture, extrusion of the COC from the follicle, integrity of the cumulus and viability and fertizability of the oocyte. The studies will establish fundamental conditions of cumulus expansion that may (1) reveal ovarian targets of diseases that affect female fertility, (2) enhance reproductive efficency in human or domestic animal IVF protocols or (3) provide a basis for targeted and reversible contraceptive strategies. (4) The studies may also elucidate aspects of IalphaI/PalphaI function relevant to functions of extracellular matrix in other tissues.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD029894-07
Application #
6351386
Study Section
Pathobiochemistry Study Section (PBC)
Program Officer
Parrott, Estella C
Project Start
1993-08-01
Project End
2003-01-31
Budget Start
2001-02-01
Budget End
2002-01-31
Support Year
7
Fiscal Year
2001
Total Cost
$257,438
Indirect Cost
Name
University of Cincinnati
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
City
Cincinnati
State
OH
Country
United States
Zip Code
45221
Nemade, Rashmi V; Carrette, Odile; Larsen, William J et al. (2002) Involvement of nitric oxide and the ovarian blood follicle barrier in murine follicular cyst development. Fertil Steril 78:1301-8
Jean, L; Mizon, C; Larsen, W J et al. (2001) Unmasking a hyaluronan-binding site of the BX(7)B type in the H3 heavy chain of the inter-alpha-inhibitor family. Eur J Biochem 268:544-53
Carrette, O; Nemade, R V; Day, A J et al. (2001) TSG-6 is concentrated in the extracellular matrix of mouse cumulus oocyte complexes through hyaluronan and inter-alpha-inhibitor binding. Biol Reprod 65:301-8
Mio, K; Carrette, O; Maibach, H I et al. (2000) Evidence that the serum inhibitor of hyaluronidase may be a member of the inter-alpha-inhibitor family. J Biol Chem 275:32413-21
Hess, K A; Chen, L; Larsen, W J (1999) Inter-alpha-inhibitor binding to hyaluronan in the cumulus extracellular matrix is required for optimal ovulation and development of mouse oocytes. Biol Reprod 61:436-43
Hess, K A; Chen, L; Larsen, W J (1998) The ovarian blood follicle barrier is both charge- and size-selective in mice. Biol Reprod 58:705-11
Larsen, W J; Chen, L; Powers, R et al. (1996) Cumulus expansion initiates physical and developmental autonomy of the oocyte. Zygote 4:335-41
Powers, R W; Chambers, C; Larsen, W J (1996) Diabetes-mediated decreases in ovarian superoxide dismutase activity are related to blood-follicle barrier and ovulation defects. Endocrinology 137:3101-10
Chen, L; Zhang, H; Powers, R W et al. (1996) Covalent linkage between proteins of the inter-alpha-inhibitor family and hyaluronic acid is mediated by a factor produced by granulosa cells. J Biol Chem 271:19409-14
Powers, R W; Chen, L; Russell, P T et al. (1995) Gonadotropin-stimulated regulation of blood-follicle barrier is mediated by nitric oxide. Am J Physiol 269:E290-8

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