title: Interleukin-6 is not essential for bone turnover in hypothyroid mice.
abstract: Interleukin-6 (IL-6) has been shown to be involved in the pathogenesis of several bone diseases characterized by an imbalance between bone resorption and formation. The aim of the study was to estimate serum markers of bone turnover: osteoclast-derived tartrate-resistant acid phosphatase form 5a (TRACP 5b) and osteocalcin in IL-6-deficient mice to assess the role of IL-6 in bone metabolism in hypothyroidism in mice. C57BL/6J (wild-type; WT) and C57BL/6J(IL6-/-Kopf) (IL-6 knock-out; IL6KO) mice randomly divided into 4 groups with 10 in each one: 1/ WT mice in hypothyroidism (WT-ht), 2/ WT controls, 3/ IL6KO mice with hypothyroidism (IL6KO-ht) and 4/ IL6KO controls. Experimental model of hypothyroidism was induced by intraperitoneal injection of propylthiouracyl. The serum levels of TRACP 5b and osteocalcin were determined by ELISA. Serum concentrations of TRACP 5b (median and interquartile ranges) were significantly decreased in both groups of mice with hypothyroidism: WT (3.2 (2.5-4.7) U/l) and IL6KO (2.6 (1.8-3.5) U/l) as compared to the respective controls. Similarly, serum osteocalcin levels were significantly reduced in both groups of mice in experimental hypothyroidism: WT (25.8 (23.0-28.2) ng/ml) and IL6KO (21.5(19.0-24.6) ng/ml) in comparison to the respective controls. There were no significant differences in bone turnover markers between IL6KO and WT mice both in hypothyroid and control animals. The results of the present study suggest that IL-6 does not play an important role in bone turnover in both euthyroid and hypothyroid mice.
authors.affiliation: Department of Endocrinology, Diabetology and Internal Diseases, Medical University of Bialystok, Bialystok, Poland. mysjan@poczta.onet.pl
authors.forename: Janusz
authors.initials: J
authors.lastname: Mysliwiec
authors.forename: Robert
authors.initials: R
authors.lastname: Zbucki
authors.forename: Maria
authors.initials: M
authors.lastname: Winnicka
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Sawicki
authors.forename: Agnieszkar
authors.initials: A
authors.lastname: Nikolajuk
authors.forename: Karol
authors.initials: K
authors.lastname: Kaminski
authors.forename: Piotr
authors.initials: P
authors.lastname: Mysliwiec
authors.forename: Wlodzimierz
authors.initials: W
authors.lastname: Musial
authors.forename: Zofia
authors.initials: Z
authors.lastname: Bondyra
authors.forename: Jerzy
authors.initials: J
authors.lastname: Walecki
authors.forename: Maria
authors.initials: M
authors.lastname: Gorska
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D000818:Animals; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D003720:Densitometry; D005260:Female; D005838:Genotype; D007037:Hypothyroidism / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D007527:Isoenzymes / Q000097:blood; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015675:Osteocalcin / Q000097:blood; D000071681:Tartrate-Resistant Acid Phosphatase; D013961:Thyroid Gland / Q000473:pathology
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D007527:Isoenzymes; D015675:Osteocalcin; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase