Research progress of metabolism and physiological functions of the lacunar-canalicular system / 中国组织工程研究

ABSTRACT

BACKGROUND:Interstitial fluid flow around the osteocytes caused by a series of physiological activities plays an important role in the osteocyte metabolism and signal transduction. OBJECTIVE:To review and summarize the research progress of bone structures and physiological functions, then further il ustrate how the mechanical loads make an impact on bone tissue. METHODS:A computer-based search was conducted in PubMed database for articles related to the bone microstructure, metabolism and osteocyte signal transduction published from January 2009 to December 2015. The keywords were“osteocyte, mechanical load, permeability, lacunar-canalicular system, interstitial fluid flow, mechanotransduction, signaling pathways”in English. Data were screened firstly, dated articles or literatures with wrong research methods were excluded, and total y 40 eligible articles were enrol ed. RESULTS AND CONCLUSION:Bone tissue can quickly adapt to the change of mechanical environment to guarantee enough osteocytes in the functional bone area indicating that osteocytes regulate the bone absorption and formation by responding to stress, which is closely related to osteocyte physiological characters. Osteocytes exist in mineralized matrix, and the special microstructures make it possible to receive mechanical loads and transform the mechanical signals into chemical signals aimed at regulating the bone absorption or formation.So the interstitial fluid flow in the lacuna-canalicular system occures, namely load-induced fluid flow, when the mechanical load is distributed on the bone. This fluid flow affects the bone tissue through two mechanismsregulating osteocyte metabolism and participating in the mechanotransduction. In conclusion, the mechanical load plays a vital role in maintaining health bone and regulating bone adaptation.