This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chapman, L. Articles by Christian, H. C. Search for Related Content PubMed PubMed Citation Articles by Chapman, L. Articles by Christian, H. C.

Externalization of Annexin I from A Folliculo-Stellate-Like Cell Line

Department of Human Anatomy and Genetics (L.C., A.N., J.F.M., H.C.C.), University of Oxford, Oxford OX1 3QX, United Kingdom; and Department of Neuroendocrinology (J.C.B.), Division of Neuroscience and Psychological Medicine, Faculty of Medicine, Imperial College of Science Technology and Medicine, Hammersmith Hospital Campus, London W12 0NN, United Kingdom

Address all correspondence and requests for reprints to: Dr. H. C. Christian, Department of Human Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom. E-mail: helen.christian{at}anat.ox.ac.uk.

Our recent studies on rat pituitary tissue suggest that the annexin I-dependent inhibitory actions of glucocorticoids may not be exerted directly on endocrine cells but indirectly via folliculo-stellate (FS) cells. FS cells contain glucocorticoid receptors and abundant annexin I. We have studied the localization of annexin I in FS cells and the ability of dexamethasone to induce annexin I secretion by an FS (TtT/GF) cell line, using Western blotting and immunofluorescence microscopy. Exposure of TtT/GF cells to dexamethasone (0.1 µM, 3 h) caused an increase in the amount of annexin I protein in the intracellular compartment and attached to the surface of the cells. In nonpermeabilized cells, immunofluorescence labeling revealed that annexin I immunoreactivity was associated with the cell surface and concentrated in focal patches on the ends of cytoplasmic processes; dexamethasone (0.1 µM, 3 h) increased both the number and intensity of these foci. Immunogold electron microscopy confirmed in anterior pituitary tissue the presence of immunoreactive-annexin at the surface of FS cell processes contacting endocrine cells. These data support our hypothesis that annexin I is released by FS cells in response to glucocorticoids to mediate glucocorticoid inhibitory actions on pituitary hormone release via a juxtacrine mechanism.

This article has been cited by other articles:

				C. D. John, V. Sahni, D. Mehet, J. F. Morris, H. C. Christian, M. Perretti, R. J. Flower, E. Solito, and J. C. Buckingham Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides FASEB J, April 1, 2007; 21(4): 1037 - 1046. [Abstract] [Full Text] [PDF]

				E. Davies, S. Omer, J. C. Buckingham, J. F. Morris, and H. C. Christian Expression and Externalization of Annexin 1 in the Adrenal Gland: Structure and Function of the Adrenal Gland in Annexin 1-Null Mutant Mice Endocrinology, March 1, 2007; 148(3): 1030 - 1038. [Abstract] [Full Text] [PDF]

				E. Davies, S. Omer, J. F Morris, and H. C Christian The influence of 17{beta}-estradiol on annexin 1 expression in the anterior pituitary of the female rat and in a folliculo-stellate cell line J. Endocrinol., February 1, 2007; 192(2): 429 - 442. [Abstract] [Full Text] [PDF]

				S. Omer, D. Meredith, J. F. Morris, and H. C. Christian Evidence for the Role of Adenosine 5'-Triphosphate-Binding Cassette (ABC)-A1 in the Externalization of Annexin 1 from Pituitary Folliculostellate Cells and ABCA1-Transfected Cell Models Endocrinology, July 1, 2006; 147(7): 3219 - 3227. [Abstract] [Full Text] [PDF]

				E. Solito, H. C. Christian, M. Festa, A. Mulla, T. Tierney, R. J. Flower, and J. C. Buckingham Post-translational modification plays an essential role in the translocation of annexin A1 from the cytoplasm to the cell surface FASEB J, July 1, 2006; 20(9): 1498 - 1500. [Abstract] [Full Text] [PDF]

				E. Theogaraj, C. D. John, H. C. Christian, J. F. Morris, S. F. Smith, and J. C. Buckingham Perinatal Glucocorticoid Treatment Produces Molecular, Functional, and Morphological Changes in the Anterior Pituitary Gland of the Adult Male Rat Endocrinology, November 1, 2005; 146(11): 4804 - 4813. [Abstract] [Full Text] [PDF]

				L. P. Chapman, M. J. Epton, J. C. Buckingham, J. F. Morris, and H. C. Christian Evidence for a Role of the Adenosine 5'-Triphosphate-Binding Cassette Transporter A1 in the Externalization of Annexin I from Pituitary Folliculo-Stellate Cells Endocrinology, March 1, 2003; 144(3): 1062 - 1073. [Abstract] [Full Text] [PDF]