Ghrelin participates in bone metabolism:the newest research progress / 中国组织工程研究

ABSTRACT

BACKGROUND:Ghrelin is a newly discovered brain-gut peptide from the stomach of human and rats. As an endogenous ligand for growth hormone secretagogue receptor (GHSR), ghrelin can notably stimulate the release of growth hormone. Although GHSR is expressed in many peripheral tissues, little is known about the influence of ghrelin on bone metabolism and GHSR expression in bone tissue. OBJECTIVE:To review the research progress of ghrelin in bone metabolism.METHODS:The first author retrieved CNKI, WanFang, PubMed, and Springerlink databases with the keywords ofGhrelin, bone metabolismin Chinese and English, respectively. The studies regarding ghrelin and its involvement in bone metabolism were included, and repetitive ones were excluded. A total of 53 eligible literatures were selected through skimming abstracts. RESULTS AND CONCLUSION:Ghrelin is a peptide composed of 28 amino acids discovered in gastric endocrine cells and hypothalamic arcuate nucleus in mice and human, which makes a great effect on digestive, nervous, immune and endocrine systems, and also plays a role in hormone secretion, glucose metabolism, immunity, cell proliferation, and inflammation. Serum ghrelin makes a certain influence on bone growth and development, and promotes the differentiation and proliferation of osteoblasts, and inhibits its apoptosis. Additionally, ghrelin suppresses the early osteogenic differentiation of C3H10T1/2 cells by upregulating the expression of Runx2 protein, and attenuates adipogenic differentiation by downregulating PPARγ2 expression, thus inducing osteogenic differentiation. However, few studies have addressed the expression of GHSR in bone tissue.