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 Tamura, M. Articles by Nagataki, S. Search for Related Content PubMed PubMed Citation Articles by Tamura, M. Articles by Nagataki, S.

Role of Apoptosis of Thyrocytes in a Rat Model of Goiter. A Possible Involvement of Fas System¹

The First Department of Internal Medicine (M.T., H.K., T.T., K.A., T.Ki., N.Y., K.E., S.N.), Department of Histology and Cell Biology (T.Ko., P.K.N.), Nagasaki University School of Medicine; and School of Allied Medical Science (T.Y.), Nagasaki University, Nagasaki 852-8501, Japan

Address all correspondence and requests for reprints to: Katsumi Eguchi, M.D., Nagasaki University School of Medicine, First Department of Internal Medicine, 1-7-1, Sakamoto, Nagasaki 852-8501, Japan. E-mail: f1078{at}cc.nagasaki-u.ac.jp

Apoptosis, a physiological process of cell death, may modulate the mass of the thyroid gland. We investigated the role of apoptosis and the possible involvement of Fas/Fas ligand (FasL) system in apoptosis during goiter formation and involution in a rat model of goiter. Rats were fed a low iodine diet and a goitrogen, 6-propyl-2-thiouracil, to induce goiter. Rats with goiter were then fed a high iodine diet to study the phase of involution. We examined the presence of apoptosis by electron microscopy (EM) and terminal deoxy-UTP nick end labeling (TUNEL). We also investigated the association between Fas and FasL expression and thyrocyte apoptosis using immunohistochemistry and Western blotting. To evaluate the proliferation of thyrocytes, proliferating cell nuclear antigen was examined immunohistochemically. The number of apoptotic cells increased during goiter formation and the early stage of involution, which were also associated with increased number of Fas-positive thyrocytes, and some of these cells contained TUNEL-positive nuclei. However, the expression of FasL was almost constant throughout the experiment. Proliferating cell nuclear antigen/TUNEL ratio markedly increased during goiter formation but decreased particularly during the late stage of goiter involution. Our results indicate that apoptosis of thyrocytes is a main factor of cell loss during goiter formation and involution and suggest that the Fas/FasL system is involved in the induction of apoptosis of these cells. Moreover, the delicate balance between apoptosis and cell proliferation may play an important role in the control of thyroid gland mass.

This article has been cited by other articles:

				J. B. Laoag-Fernandez, H. Matsuo, H. Murakoshi, A. L. Hamada, B. K. Tsang, and T. Maruo 3,5,3'-Triiodothyronine Down-Regulates Fas and Fas Ligand Expression and Suppresses Caspase-3 and Poly (Adenosine 5'-Diphosphate-Ribose) Polymerase Cleavage and Apoptosis in Early Placental Extravillous Trophoblasts in Vitro J. Clin. Endocrinol. Metab., August 1, 2004; 89(8): 4069 - 4077. [Abstract] [Full Text] [PDF]

				E. Mezosi, H. Yamazaki, J. D. Bretz, S. H. Wang, P. L. Arscott, S. Utsugi, P. G. Gauger, N. W. Thompson, and J. R. Baker Jr. Aberrant Apoptosis in Thyroid Epithelial Cells from Goiter Nodules J. Clin. Endocrinol. Metab., September 1, 2002; 87(9): 4264 - 4272. [Abstract] [Full Text] [PDF]

				J.-D. Lin The role of apoptosis in autoimmune thyroid disorders and thyroid cancer BMJ, June 23, 2001; 322(7301): 1525 - 1527. [Full Text] [PDF]

				T. Koji, Y. Hishikawa, H. Ando, Y. Nakanishi, and N. Kobayashi Expression of Fas and Fas Ligand in Normal and Ischemia-Reperfusion Testes: Involvement of the Fas System in the Induction of Germ Cell Apoptosis in the Damaged Mouse Testis Biol Reprod, March 1, 2001; 64(3): 946 - 954. [Abstract] [Full Text]

				M. H Al-Maini, J. D Mountz, H. A Al-Mohri, E. M El-Ageb, B. M Al-Riyami, K. L G Svenson, T. Zhou, and E. R Richens Serum levels of soluble Fas correlate with indices of organ damage in systemic lupus erythematosus Lupus, February 1, 2000; 9(2): 132 - 139. [Abstract] [PDF]

				K. Ejima, T. Koji, D. Tsuruta, H. Nanri, M. Kashimura, and M. Ikeda Induction of Apoptosis in Placentas of Pregnant Mice Exposedto Lipopolysaccharides: Possible Involvement of Fas/Fas Ligand System Biol Reprod, January 1, 2000; 62(1): 178 - 185. [Abstract] [Full Text]

				J. D. Bretz, P. L. Arscott, A. Myc, and J. R. Baker Jr. Inflammatory Cytokine Regulation of Fas-mediated Apoptosis in Thyroid Follicular Cells J. Biol. Chem., September 3, 1999; 274(36): 25433 - 25438. [Abstract] [Full Text] [PDF]

				J. D. Bretz, M. Rymaszewski, P. L. Arscott, A. Myc, K. B. Ain, N. W. Thompson, and J. R. Baker Jr. TRAIL Death Pathway Expression and Induction in Thyroid Follicular Cells J. Biol. Chem., August 13, 1999; 274(33): 23627 - 23632. [Abstract] [Full Text] [PDF]