Our long-term objective is to understand the mechanisms that regulate the permeability of epithelia of the female reproductive tract. We have discovered that estrogen modulates the Resistance of the Lateral Intercellular Space (R-LIS) of human normal ectocervical-vaginal epithelial cells (ECVE), and decreases the paracellular resistance. The geometry of the lateral intercellular space (and the R-LIS) is determined by the shape of epithelial cells that define this space, and depends on the rigidity of the cytoskeleton. Based on novel preliminary results we advance our Maior Hypothesis that estrogen decreases the rigidity of the cytoskeleton by remodeling the cortical acto-myosin frame. The study has four Specific Aims: (1) To understand how estrogen remodels the cytoskeletal cortical acto-myosin frame. Our Hypothesis-A is that formation of a rigid cortical frame depends on the interaction of nonmuscle myosin IIB with cortical actin. We propose that estrogen remodels the cytoskeleton into a flexible structure by inducing disassembly of nonmusele myosin lIB from the cortical actin ring. (2) To understand the structural basis of the cortical acto-myosin cytoskeletal ring in epithelial cells. Our Hypothesis-B is that in epithelial cells the stability of the cortical myosin-actin ring depends on the interaction of actin with homodimerized nonmuscle myosin IIB filaments. We propose that dedimerization of nonmuscle myosin IIB heavy chains inhibits myosin MgATPase activity, and leads to disassociation of nonmuscle myosin IIB from the cortical acto-myosin frame. (3) To understand the mechanism by which phosphorylation of nonmuscle myosin IIB heavy chains regulates MgATPase activity. Our Hypothesis-C is that that phosphorylation of nonmuscle myosin IIB heavy chains inhibits homodimerization of myosin filaments and blocks myosin MgATPase. The alternative hypothesis is that MgATPase can be regulated independent of dimerization, by phosphorylation of nonmuscle myosin lIB heavy chains directly at the motor domain. (4) To understand the signaling pathway of the estrogen-induced phosphorylation of nonmuscle myosin IIB heavy chains. Our Hypothesis-D is that the effect of estrogen is initiated by activation of the EGFR-MAPK pathway, and it involves casein kinase II (CKII) as the terminal kinase. The extended hypothesis postulates involvement of multimolecular complexes, including Rho-kinase and an unidentified phosphatase, as modulators of CKII-induced phosphorylation of nonmuscle myosin IIB heavy chains. Experiments will utilize tissues of human ectocervix and vagina obtained from women undergoing surgery, and cultures of human ECVE cells grown on filters. Health relatedness of the project: The results of the study may provide novel data about estrogen regulation of the permeability of the female reproductive tract epithelia, and improve our understanding of the physiology of reproduction: the pathophysiology of inflammatory and infectious disease in the genital tract; and for improving woman's health. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG015955-07
Application #
6891326
Study Section
Reproductive Endocrinology Study Section (REN)
Program Officer
Bellino, Francis
Project Start
1999-06-01
Project End
2008-05-31
Budget Start
2005-06-01
Budget End
2006-05-31
Support Year
7
Fiscal Year
2005
Total Cost
$377,500
Indirect Cost
Name
Case Western Reserve University
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Fu, Wen; McCormick, Tom; Qi, Xiaoping et al. (2009) Activation of P2X(7)-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice. BMC Cancer 9:114
Li, Xin; Qi, Xiaoping; Zhou, Lingyin et al. (2009) P2X(7) receptor expression is decreased in epithelial cancer cells of ectodermal, uro-genital sinus, and distal paramesonephric duct origin. Purinergic Signal 5:351-68
Li, Xin; Qi, Xiaoping; Zhou, Lingyin et al. (2007) Decreased expression of P2X7 in endometrial epithelial pre-cancerous and cancer cells. Gynecol Oncol 106:233-43
Gorodeski, George I (2007) Estrogen decrease in tight junctional resistance involves matrix-metalloproteinase-7-mediated remodeling of occludin. Endocrinology 148:218-31
Gorodeski, George I (2007) Estrogen modulation of epithelial permeability in cervical-vaginal cells of premenopausal and postmenopausal women. Menopause 14:1012-9
Gorodeski, George I (2007) Estrogen modulation of MgATPase activity of nonmuscle myosin-II-B filaments. Endocrinology 148:279-92
Feng, Ying-Hong; Li, Xin; Wang, Liqin et al. (2006) A truncated P2X7 receptor variant (P2X7-j) endogenously expressed in cervical cancer cells antagonizes the full-length P2X7 receptor through hetero-oligomerization. J Biol Chem 281:17228-37
Zhu, Ling; Li, Xin; Zeng, Robin et al. (2006) Changes in tight junctional resistance of the cervical epithelium are associated with modulation of content and phosphorylation of occludin 65-kilodalton and 50-kilodalton forms. Endocrinology 147:977-89
Li, Xin; Zhou, Lingying; Feng, Ying-Hong et al. (2006) The P2X7 receptor: a novel biomarker of uterine epithelial cancers. Cancer Epidemiol Biomarkers Prev 15:1906-13
Li, Xin; Zhou, Lingying; Gorodeski, George I (2006) Estrogen regulates epithelial cell deformability by modulation of cortical actomyosin through phosphorylation of nonmuscle myosin heavy-chain II-B filaments. Endocrinology 147:5236-48

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