Restoration of Cellular Proliferation and Characteristics of Human Tenocytes by Vitamin D

• Published in: Journal of orthopaedic research Vol. 37; no. 10; pp. 2241 - 2248
• Main Authors: Min, Kyunghoon, Lee, Ji Min, Kim, Mi Jin, Jung, Sang Youn, Kim, Kyung‐Soo, Lee, Soonchul, Choi, Yong‐Soo
• Format: Journal Article
• Language: English
• Published: United States 01.10.2019
• Subjects: 1‐α‐hydroxylase; Bone Density Conservation Agents - therapeutic use; Cell Proliferation - drug effects; Cells, Cultured; dexamethasone; Dexamethasone - adverse effects; Drug Evaluation, Preclinical; Glucocorticoids - adverse effects; Humans; MAP Kinase Signaling System - drug effects; Receptors, Calcitriol - metabolism; Steroid Hydroxylases - metabolism; tenocyte; Tenocytes - drug effects; Tenocytes - metabolism; vitamin D; Vitamin D - therapeutic use; vitamin D receptor; dexamethasone; vitamin D receptor; tenocyte; 1-α-hydroxylase; vitamin D
• ISSN: 0736-0266; 1554-527X; 1554-527X
• DOI: 10.1002/jor.24352

ABSTRACT Vitamin D (Vit D) increases calcium absorption in the intestine after binding to the Vit D receptor (VDR). The VDR has also been identified in muscle cells. Vit D supplementation resulted in improved muscle strength. However, there is a paucity of studies of the role of Vit D on tenocytes. We investigated the effects of Vit D on damaged tenocytes. Human tenocytes were treated with dexamethasone (Dex) to induce cell injury. Expression of the tenocyte‐related markers tenomodulin (Tnmd), tenascin C (Tnc), scleraxis (Scx), mohawk (Mkx), and collagen (Col) 1 and 3 were measured. Then, tenocytes were cotreated with Vit D. 1‐α‐Hydroxylase and VDR were explored in tenocytes. With 10 μM Dex, the growth of tenocytes was significantly inhibited, and the gene expression of Tnmd, Tnc, Scx, Mkx, Col 1 and 3 also decreased. When tenocytes were cotreated with Vit D, cell proliferation recovered in a dose‐dependent manner, and the expression of TNMD and Col 1 improved. When studying the mechanisms of the effects of Vit D on tenocytes, reactive oxygen species produced by Dex decreased with Vit D, and the phosphorylation of extracellular signal–regulated kinase and p38 was stimulated by Vit D cotreatment. 1‐α‐Hydroxylase and VDR were found in tenocytes, indicating that the cells have the ability to use an inactive form of Vit D and interact with it. Vit D is known to perform diverse actions and its protective effects on tenocytes suggest its beneficial role in tendon in addition to muscle and bone. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2241–2248, 2019