title: Conditional deletion of insulin receptor in thyrocytes does not affect thyroid structure and function.
abstract: Thyroid-stimulating hormone (TSH) is the primary regulator of thyroid growth and function acting via cyclic AMP signaling cascades.  In cultured thyrocytes, insulin and/or insulin-like growth factor-1 (IGF-1) are required for mediating thyrocyte proliferation in concert with TSH.  To determine the role of insulin signaling in thyroid, growth in vivo, mice with thyrocyte-selective ablation of the insulin receptor (IR) were generated by crossing mice homozygous for a floxed IR allele with transgenic mice in which thyrocyte-specific expression of Cre recombinase was driven by the human thyroid peroxidase (TPO) gene promoter.  Immunohistochemistry and Western blot analysis confirmed near complete loss of IR expression in the thyroid of thyrocyte IR knockout mice.  These mice are viable and have no obvious thyroid dysfunction and macro- and microscopic thyroid morphology was normal.  Thus, insulin signaling in thyrocytes does not play an essential role in the architecture and function of the thyroid in vivo.
authors: Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Chung-Ang University, Seoul, Korea.
authors: Sangmi
authors: S
authors: Ock
authors: Seok Hong
authors: SH
authors: Lee
authors: Jihyun
authors: J
authors: Ahn
authors: Tae Jin
authors: TJ
authors: Lee
authors: Chung-Hyun
authors: CH
authors: Cho
authors: E Dale
authors: ED
authors: Abel
authors: Shioko
authors: S
authors: Kimura
authors: Jaetaek
authors: J
authors: Kim
mesh_terms: D000818:Animals; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000502:physiology; D019426:Integrases / Q000235:genetics / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D012313:RNA / Q000737:chemistry / Q000235:genetics; D011972:Receptor, Insulin / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013047:Specific Pathogen-Free Organisms; D013961:Thyroid Gland / Q000166:cytology / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D012313:RNA; D007334:Insulin-Like Growth Factor I; D013972:Thyrotropin; D011972:Receptor, Insulin; C045073:Cre recombinase; D019426:Integrases; D013974:Thyroxine