Polystyrene microplastic‐induced endoplasmic reticulum stress contributes to growth plate endochondral ossification disorder in young rat

作者：Qingqing Zhang, Yuanyuan Lang, Xiaomin Tang, Wenshu Cheng, Zugen Cheng, Mohammad Rizwan, Lixin Xie, Yanling Liu, Yanling Liu, Hengyi Xu, Yang Liu, Yang Liu · 发表于：Environmental Toxicology · 年份：2024 · DOI：10.1002/tox.24182 · 被引用次数：25 · 研究领域：Microplastics and Plastic Pollution、biodegradable polymer synthesis and properties、Effects and risks of endocrine disrupting chemicals

BACKGROUND: Previous studies on the effects of microplastics (MPs) on bone in early development are limited. This study aimed to investigate the adverse effects of MPs on bone in young rats and the potential mechanism. METHODS: Three-week-old female rats were orally administered MPs for 28 days, and endoplasmic reticulum (ER) stress inhibitor salubrinal (SAL) and ER stress agonist tunicamycin (TM) were added to evaluate the effect of ER stress on toxicity of MPs. The indicators of growth and plasma markers of bone turnover were evaluated. Tibias were analyzed using micro-computed tomography (micro-CT). Histomorphological staining of growth plates was performed, and related gene expression of growth plate chondrocytes was tested. RESULTS: After exposure of MPs, the rats had decreased growth, shortened tibial length, and altered blood calcium and phosphorus metabolism. Trabecular bone was sparse according to micro-CT inspection. In the growth plate, the thickness of proliferative zone substantial reduced while the thickness of hypertrophic zone increased significantly, and the chondrocytes were scarce and irregularly arranged according to tibial histological staining. The transcription of the ER stress-related genes BIP, PERK, ATF4, and CHOP dramatically increased, and the transcription factors involved in chondrocyte proliferation, differentiation, apoptosis, and matrix secretion were aberrant according to RT-qPCR and western blotting. Moreover, the addition of TM showed highe...