title: Expression of Glucagon-Like Peptide 1 Receptor during Osteogenic Differentiation of Adipose-Derived Stem Cells.
abstract: BACKGROUND
  Glucagon-like peptide 1 (GLP-1), an incretin hormone well known for its glucose-lowering effect, was recently reported to exert an anabolic effect on bone. Although the exact mechanism is not known, it likely involves the GLP-1 receptor (GLP-1R), which is expressed in some osteoblastic cell lines. Adipose-derived stem cells (ADSCs) have mesenchymal stem cell-specific characteristics, including osteoblastic differentiation potential. We evaluated the expression of GLP-1R during osteogenic differentiation of ADSCs.
  
  
  METHODS
  ADSCs were isolated from subcutaneous adipose tissue obtained from three male donors during plastic surgery and were subjected to osteogenic induction. Mineralization was assessed by Alizarin Red staining on day 21. Expression of alkaline phosphatase (ALP), osteocalcin (OC), and GLP-1R was measured by real-time polymerase chain reaction in triplicate for each patient on days 0, 7, 14, and 21. Target mRNA expression levels were normalized to that of β-actin.
  
  
  RESULTS
  ADSCs were fibroblast-like in morphology, adhered to plastic, and had multipotent differentiation potential, as assessed using specific antigen markers. The osteogenic markers ALP and OC were notably upregulated at 21 days. Osteogenic differentiation resulted in a time-dependent increase in the expression of GLP-1R (P=0.013).
  
  
  CONCLUSIONS
  We demonstrated upregulation of GLP-1R gene expression during osteogenic differentiation of ADSCs. This finding suggests that GLP-1 may induce osteogenic differentiation in bone tissue.
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Korea.; Biomedical Research Institute, Pusan National University, Korea.
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Jeon
authors.affiliation: Kim Yong Ki Internal Medicine Clinic, Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Bae
authors.affiliation: Biomedical Research Institute, Pusan National University, Korea.
authors.forename: Ju In
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Kim Yong Ki Internal Medicine Clinic, Korea.; Department of Plastic and Reconstructive Surgery, Pusan National University Hospital, Korea.
authors.forename: Joo Hyoung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Kim Yong Ki Internal Medicine Clinic, Korea.; Department of Plastic and Reconstructive Surgery, Pusan National University Hospital, Korea.
authors.forename: Soo Jong
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kosin University College of Medicine, Korea.
authors.forename: Su Kyoung
authors.initials: SK
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Good Moonhwa Hospital, Busan, Korea.
authors.forename: Joon Hyop
authors.initials: JH
authors.lastname: An
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Korea.; Biomedical Research Institute, Pusan National University, Korea.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Korea.; Biomedical Research Institute, Pusan National University, Korea.
authors.forename: Bo Hyun
authors.initials: BH
authors.lastname: Kim
authors.affiliation: Kim Yong Ki Internal Medicine Clinic, Korea.
authors.forename: Yong Ki
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Pusan National University School of Medicine, Korea.; Biomedical Research Institute, Pusan National University, Korea. injkim@pusan.ac.kr.
authors.forename: In Joo
authors.initials: IJ
authors.lastname: Kim
keywords: Adipose-derived stem cell; Glucagon-like peptide 1; Glucagon-like peptide 1 receptor; Osteogenesis