title: Effect of Prolonged Iodine Overdose on Type 2 Iodothyronine Deiodinase Ubiquitination-Related Enzymes in the Rat Pituitary.
abstract: The purpose of this study is to determine the effect of prolonged iodine overdose on type 2 iodothyronine deiodinase (D2) ubiquitination-related enzymes. Male Wistar rats were fed different doses of iodine and were then euthanized at the 4, 8, 12, or 24 weeks (4w, 8w, 12w, or 24w) after iodine administration. Urinary iodine concentration (UIC), thyroid-stimulating hormone (TSH), total thyroxine (TT4), and total triiodothyronine (TT3) were determined. Real-time quantitative RT-PCR and Western blot were used to measure mRNA and protein expression levels of pituitary D2 as well as two D2-specific ubiquitin ligases [WD repeat and SOCS box-containing protein 1 (WSB-1), membrane-associated ring finger (C3HC4) 6 (MARCH6 or TEB4)] and two D2-specific deubiquitinating enzymes [ubiquitin-specific peptidase 20 (USP20) and ubiquitin-specific peptidase 33 (USP33)]. The mRNA and protein expression levels of USP19, a TEB4-specific deubiquitinating enzyme, were also measured. Prolonged high iodine intake significantly increased TSH expression. At 12w, TSH was 1.57-, 1.44-, and 2.11-fold of NI group in 6HI, 10HI, and 50HI groups, respectively. At 24w, TSH had increased to 2.11-fold in the 50HI group. The pituitary D2 protein level decreased at 12w and 24w; though the mRNA level did not change. Prolonged iodine intake increased mRNA and protein expression levels of pituitary WSB-1 and TEB4. High iodine intake had no discernible effects on USP20. Temporary increases in USP33 and USP19 mRNA levels were observed. The enzymes related to D2 ubiquitination change with prolonged high iodine intake. Increased D2 ubiquitination suppresses the activity of D2, causing a decrease in negative feedback of the hypothalamic-pituitary-thyroid axis.
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Zhang
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Yaqiu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Han
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Xie
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Han
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Chenling
authors.initials: C
authors.lastname: Fan
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Shuangning
authors.initials: S
authors.lastname: Ding
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China.
authors.forename: Zhongyan
authors.initials: Z
authors.lastname: Shan
authors.affiliation: The Endocrine Institute and the Liaoning Provincial Key Laboratory of Endocrine Diseases, Department of Endocrinology and Metabolism, The First Hospital of China Medical University, No.155, North Nanjing Street, Heping District, Shenyang, China. twp@vip.163.com.
authors.forename: Weiping
authors.initials: W
authors.lastname: Teng
mesh_terms: D000818:Animals; D062787:Drug Overdose / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D007030:Hypothalamo-Hypophyseal System / Q000201:enzymology*; D007453:Iodide Peroxidase / Q000378:metabolism; D007455:Iodine / Q000009:adverse effects* / Q000494:pharmacology; D008297:Male; D010902:Pituitary Gland / Q000201:enzymology*; D010913:Pituitary-Adrenal System / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D043222:Ubiquitin Thiolesterase / Q000096:biosynthesis*; D044767:Ubiquitin-Protein Ligases / Q000096:biosynthesis*; D000097564:Iodothyronine Deiodinase Type II
chemical_list: D007453:Iodide Peroxidase; D007455:Iodine; D043222:Ubiquitin Thiolesterase; D044767:Ubiquitin-Protein Ligases; D000097564:Iodothyronine Deiodinase Type II; C543895:Marchf6 protein, rat
keywords: Iodine; Thyroid-stimulating hormone (TSH); Type 2 iodothyronine deiodinase (D2); Ubiquitination