Poster Presentation 29th Australian and New Zealand Bone and Mineral Society Annual Scientific Meeting 2019

Correlation between phosphorus concentration and autophagy. (#167)

Muneteru Sasaki 1 , Shinichiro Kuroshima 1 , Takashi Sawase 1
  1. Department of Applied Prosthodontics, Institute of Biomedical Sciences, Nagasaki University, Nagasaki, Japan

Purpose

Phosphorus is one of the essential mineral. It is requisite for homeostasis. Phosphorus has been thought to relate with human senescence. Bone density is decreased by Aging Consequently, the risk of bone fractures is increased. However, the effects of phosphorus on osteoblast senescence are unclear. Furthermore, autophagy is very important function about cell homeostasis. But effect of phosphorus concentration on autophagy are unclear. The aim of this study was to investigate the effects of phosphorus concentration on osteoblast senescence and autophagy.

Materials and Methods

C57B6L/6J mice (3-week-old) were used. Mice were divided into 3 groups. A low phosphorus diet (P; 0.2%, Ca; 0.6%) (LPD), normal phosphorus diet (P; 0.6%, Ca; 0.6%) (control), and high phosphorus diet (P; 1.73%, Ca; 0.58%) (HPD)were fed with each group (n=7 per each group). Euthanasia was performed after 1, 2, 3 and 4 weeks after the onset of phosphorus-controlled diet. Histomorphometric and immunohistochemical analyses were performed using long bones.

Results

Growth disturbance were noted in HPD vs. control and LPD. Thinner cortical bone was observed in HPD vs. control and LPD. Localization of P53 aging marker was changed in HPD vs. control and LPD. Moreover, altered distribution of autophagy marker was observed in HPD vs. control and LPD

Discussion

High concentration of phosphorus accelerated osteoblast senescence. Moreover, phosphorus concentration affected autophagy.