Characterization of integrin expression in the mouse ovary.
Integrin alpha:beta heterodimers mediate cell contacts to the extracellular matrix and initiate intracellular signaling cascades in response to a variety of factors. Integrins interact with many determinants of cellular phenotypes and play roles in controlling the development, structural integrity, and function of every type of tissue. Despite their importance, little is known about the regulation of integrin subunits in the mammalian ovary and how they function in folliculogenesis. To determine their relevance to ovarian physiology, we have studied the expression of integrin subunit mRNAs by Northern blot analysis and in situ hybridization in ovaries of wild-type, growth differentiation factor 9 (Gdf 9) knockout, FSHbeta (Fshb) knockout, and inhibin alpha (Inha) knockout mice. Integrin alpha6 mRNA is expressed in oocytes and granulosa cells of single-layer follicles and in oocytes and theca cells of multilayer follicles. Integrin alpha6 is highly expressed in Gdf 9 knockout ovaries, which are enriched in oocytes and primary (single layer) follicles because of a block at this stage of follicular development. Integrin alpha(v) mRNA is most highly expressed in the granulosa cells of multilayer growing follicles, and therefore only low levels of expression are detectable in the Gdf 9 knockout ovaries. Integrin beta1 mRNA exhibits a broad expression pattern in ovaries, including oocytes, granulosa cells, theca cells, and corpora lutea. Integrin beta3 mRNA is expressed in theca and interstitial cells and is upregulated in corpora lutea. It is nearly undetectable in ovaries of Fshb knockout mice, which develop preantral follicles but have no luteal cells. Integrin beta5 mRNA is predominantly expressed in granulosa cells of multilayer follicles. It is expressed at high levels in the Fshb knockout mice and in a compartmentalized manner in the granulosa cell/Sertoli cell tumors that develop in the Inha knockout mice. Specific integrins are associated with ovarian cellular phenotypes in mice, which raises intriguing possibilities as to integrin functions in oocyte competence, follicular development, luteinization, and granulosa cell proliferation.
Burns
Kathleen H
KH
Department of Pathology, Baylor College of Medicine, Houston, Texas 77030, USA.
Owens
Gabe E
GE
Fernandez
Julianna M
JM
Nilson
John H
JH
Matzuk
Martin M
MM
D000818:Animals; D015152:Blotting, Northern; D055430:Bone Morphogenetic Protein 15; D005260:Female; D037201:Follicle Stimulating Hormone, beta Subunit / Q000172:deficiency / Q000235:genetics; D015870:Gene Expression; D055429:Growth Differentiation Factor 9; D017403:In Situ Hybridization; D039503:Integrin alpha6 / Q000235:genetics; D039564:Integrin alphaV / Q000235:genetics; D039641:Integrin beta Chains / Q000235:genetics; D019012:Integrin beta1 / Q000235:genetics; D039661:Integrin beta3 / Q000235:genetics; D016023:Integrins / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010053:Ovary / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
C525902:Bmp15 protein, mouse; D055430:Bone Morphogenetic Protein 15; D037201:Follicle Stimulating Hormone, beta Subunit; C525898:Gdf9 protein, mouse; D055429:Growth Differentiation Factor 9; D039503:Integrin alpha6; D039564:Integrin alphaV; D039641:Integrin beta Chains; D019012:Integrin beta1; D039661:Integrin beta3; D016023:Integrins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C084344:integrin beta5