Endometriosis is a disease that causes debilitating pain and loss of fertility in women. Despite these devastating effects, the mechanism by which this enigmatic disease exerts these pathogenicities is unknown. Although histologically similar to uterine endometrium, endometriotic tissue is biochemically different from its uterine counterpart in a variety of fashions. The altered biochemical characteristics of the endometriotic tissue may be involved with anomalies of the immune system, ovulation, fertilization, and implantation which have all been implicated as causes of endometriosis-associated infertility. Using a rat model for endometriosis, two previously unknown endometriosis-associated proteins have been identified. A progesterone- induced uterine protein, PUP-1, may play a role in normal reproductive processes including implantation. Curiously, synthesis and/or secretion of PUP-1 by the endometriotic implant is 24 hours out of phase with that of the uterine endometrium. A second protein, EP-1, is synthesized by endometriotic but not endometrial tissue. EP-1 may be a useful marker of endometriosis and have a role in the pathophysiology of the disease. PUP-1 and EP-1 have recently been identified in culture media from purified rat and human endometrial and endometriotic implant stromal cells, respectively. The goal of this proposal is to purify and characterize both rat and human PUP-1 and EP-1 in order to obtain insight into the structure, mode of expression and physiological function of these proteins.
The specific aims of this project are to: 1) develop a purification scheme for PUP-1 and EP-1; 2) generate a) antisera, b) radioimmunoassays and c) limited protein sequence data for PUP-1 and EP-1; and 3) molecularly clone cDNA representing PUP-1 and EP-1 and obtain nucleotide sequence data. Protein purification will employ cell culture and chromatographic techniques. the antisera, radioimmunoassays and protein sequence data derived from the purified proteins will be used to detect and monitor the distribution of PUP-1 and EP-1 in various tissues and in sera throughout the reproductive cycle, during early pregnancy and following steroid treatment as well as to obtain DNA sequence data for PUP-1 and EP-1. The nucleic acid sequence data will be compared to other sequence information in data banks to provide further insight into the identity and possible function of the proteins. These studies will support long term goals which include determining the role of PUP-1 and EP-1 in reproductive function and the pathophysiology of endometriosis. The characterization of PUP-1 and EP-1 may also lead to the development of non-invasive serum markers for progesterone- dependent endometrial function and the disease endometriosis. Ultimately, these studies may lead to improved diagnostic, prognostic and therapeutic methods for the management of endometriosis.
