title: Unique temporal and spatial expression patterns of IL-33 in ovaries during ovulation and estrous cycle are associated with ovarian tissue homeostasis.
abstract: Ovaries are among the most active organs. Frequently occurring events such as ovulation and ovarian atresia are accompanied with tissue destruction and repairing. Critical roles of immune cells or molecules in those events have been well recognized. IL-33 is a new member of the IL-1 cytokine gene family. Recent studies suggest its roles beyond immune responses. We systemically examined its expression in ovaries for its potential roles in ovarian functions. During ovulation, a high level of IL-33 was transiently expressed, making it the most significantly upregulated immune gene. During estrous cycle, IL-33 expression levels fluctuated along with numbers of ovarian macrophages and atresia wave. Cells with nuclear form of IL-33 (nIL-33(+) cells) were mostly endothelial cells of veins, either in the inner layer of theca of ovulating follicles during ovulation, or surrounding follicles during estrous cycle. Changes in number of nIL-33(+) cells showed a tendency similar to that in IL-33 mRNA level during estrous cycle. However, the cell number sharply declined before a rapid increase of macrophages and a surge of atresia. The decline in nIL-33(+) cell number was coincident with detection of higher level of the cytokine form of IL-33 by Western blot, suggesting a release of cytokine form of IL-33 before the surge of macrophage migration and atresia. However, IL-33 Ab, either by passive transfer or immunization, showed a limited effect on ovulation or atresia. It raises a possibility of IL-33's role in tissue homeostasis after ovarian events, instead of a direct involvement in ovarian functions.
authors.affiliation: Department of Diagnostic Sciences, University of Texas Health Science Center at Houston, Houston, TX 77054;
authors.forename: Colin I
authors.initials: CI
authors.lastname: Carlock
authors.affiliation: Department of Diagnostic Sciences, University of Texas Health Science Center at Houston, Houston, TX 77054;
authors.forename: Jean
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Diagnostic Sciences, University of Texas Health Science Center at Houston, Houston, TX 77054;
authors.forename: Cindy
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Department of Diagnostic Sciences, University of Texas Health Science Center at Houston, Houston, TX 77054;
authors.forename: Kiana
authors.initials: K
authors.lastname: Tatum
authors.affiliation: Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030; and.
authors.forename: Henry P
authors.initials: HP
authors.lastname: Adams
authors.affiliation: Department of Internal Medicine, University of Texas School of Medicine at Houston, Houston, TX 77030.
authors.forename: Filemon
authors.initials: F
authors.lastname: Tan
authors.affiliation: Department of Diagnostic Sciences, University of Texas Health Science Center at Houston, Houston, TX 77054; Yahuan.Lou@uth.tmc.edu.
authors.forename: Yahuan
authors.initials: Y
authors.lastname: Lou
mesh_terms: D000818:Animals; D030762:Estrous Cycle / Q000276:immunology*; D005260:Female; D005496:Follicular Atresia / Q000276:immunology; D005786:Gene Expression Regulation / Q000276:immunology*; D006706:Homeostasis / Q000276:immunology*; D000067596:Interleukin-33; D007378:Interleukins / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009687:Nuclear Proteins / Q000276:immunology*; D010053:Ovary / Q000276:immunology*; D010060:Ovulation / Q000276:immunology*; D012333:RNA, Messenger / Q000276:immunology
chemical_list: C506535:Il33 protein, mouse; D000067596:Interleukin-33; D007378:Interleukins; D009687:Nuclear Proteins; D012333:RNA, Messenger