Plasticizer di(2-ethylhexyl)phthalate interferes with osteoblastogenesis and adipogenesis in a mouse model

Chen-Yuan Chiu; Shih-Chun Sun; Chih-Kang Chiang; Ching-Chia Wang; Ding-Cheng Chan; Huang-Jen Chen; Shing-Hwa Liu; Rong-Sen Yang

doi:10.1002/jor.23740

Plasticizer di(2-ethylhexyl)phthalate interferes with osteoblastogenesis and adipogenesis in a mouse model

J Orthop Res. 2018 Apr;36(4):1124-1134. doi: 10.1002/jor.23740. Epub 2017 Oct 9.

Authors

Chen-Yuan Chiu^{1

2}, Shih-Chun Sun¹, Chih-Kang Chiang^{1

3}, Ching-Chia Wang⁴, Ding-Cheng Chan⁵, Huang-Jen Chen¹, Shing-Hwa Liu^{1

4

6}, Rong-Sen Yang⁷

Affiliations

¹ Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
² Department of Cell and Tissue Engineering, Changhua Christian Hospital, Changhua, Taiwan.
³ Departments of Integrated Diagnostics and Therapeutics and Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁴ Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁵ Department of Geriatrics and Gerontology, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁶ Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.
⁷ Department of Orthopaedics, College of Medicine, National Taiwan University, Taipei, Taiwan.

PMID: 28921615
DOI: 10.1002/jor.23740

Abstract

Plasticizer di(2-ethylhexyl)phthalate (DEHP) can leach from medical devices such as blood storage bags and the tubing. Recently, epidemiological studies showed that phthalate metabolites levels in the urine are associated with low bone mineral density (BMD) in older women. The detailed effect and mechanism of DEHP on osteoblastogenesis and adipogenesis, and bone loss remain to be clarified. Here, we investigated the effect and mechanism of DEHP and its active metabolite mono(2-ethylhexyl)phthalate (MEHP) on osteoblastogenesis and adipogenesis. The in vitro study showed that osteoblast differentiation of bone marrow stromal cells (BMSCs) was significantly and dose-dependently decreased by DEHP and MEHP (10-100 µM) without cytotoxicity to BMSCs. The mRNA expressions of alkaline phosphatase, Runx2, osteocalcin (OCN), Wnt1, and β-catenin were significantly decreased in DEHP- and MEHP-treated BMSCs during differentiation. MEHP, but not DEHP, significantly increased the adipocyte differentiation of BMSCs and PPARγ mRNA expression. Both DEHP and MEHP significantly increased the ratios of phosphorylated β-catenin/β-catenin and inhibited osteoblastogenesis, which could be reversed by Wnt activator lithium chloride and PPARγ inhibitor T0070907. Moreover, exposure of mice to DEHP (1, 10, and 100 mg/kg) for 8 weeks altered BMD and microstructure. In BMSCs isolated from DEHP-treated mice, osteoblastogenesis and Runx2, Wnt1, and β-catenin expression were decreased, but adipogenesis and PPARγ expression were increased. These findings suggest that DEHP and its metabolite MEHP exposure may inhibit osteoblastogenesis and promote adipogenesis of BMSCs through the Wnt/β-catenin-regulated and thus triggering bone loss. PPARγ signaling may play an important role in MEHP- and DEHP-induced suppression of osteogenesis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1124-1134, 2018.

Keywords: adipogenesis; bone marrow stromal cells; bone mineral density; di(2-ethylhexyl)phthalate; osteoblastogenesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adipogenesis / drug effects*
Animals
Cell Survival / drug effects
Diethylhexyl Phthalate / adverse effects*
Diethylhexyl Phthalate / analogs & derivatives
Gene Expression / drug effects
Male
Mesenchymal Stem Cells / drug effects
Mice, Inbred ICR
Osteoblasts / drug effects*
Osteogenesis / drug effects*
PPAR gamma / metabolism
Plasticizers / adverse effects*
Wnt Signaling Pathway

Substances

PPAR gamma
Plasticizers
Diethylhexyl Phthalate
mono-(2-ethylhexyl)phthalate