title: Human osteopenic bone-derived osteoblasts: essential amino acids treatment effects.
abstract: The development of in vitro cell culture methods has made it possible to study bone cell metabolism and growth and obtain a deeper insight into the pathophysiology of common orthopedic diseases such as osteoporosis. After analyzing the effect of two essential amino acids, L-arginine (Arg) and L-lysine (Lys), in previous in vitro and in vivo studies, the present authors investigated the administration of Arg and Lys in osteoblasts derived from human osteopenic bone. After isolation, osteoblasts were cultured in DMEM supplemented with either Arg (0.625 mg/ml/day, Arg Group) or Lys (0.587 mg/ml/day, Lys Group), or both of them (Arg-Lys Group), whereas the Control Group was sham-treated. After 7 days the following parameters were tested in all groups: MTT proliferation test, Alkaline Phosphatase (ALP), Nitric Oxide (NO), Calcium (Ca), Phosphorus (P), Osteocalcin (OC), C-Terminal Procollagen type I (PICP), Interleukin-6 (IL-6), Transforming Growth Factor-beta 1 (TGF-beta 1), Platelet Derived Growth Factor (PDGF) and Insulin-Like Growth Factor-I (IGF-I). Results were compared with those obtained from human healthy bone to verify the effect of the amino acids on osteoblasts derived from pathological tissue. In addition, a comparison was also made with the results obtained from rat osteopenic bone to assess reliability of the in vitro model. The current results support previous findings and indicate that Arg and Lys stimulation has a positive effect on osteoblast proliferation, activation and differentiation. Therefore, administration of these amino acids may be useful in clinical treatment and prevention of osteoporosis.
authors.affiliation: Experimental Surgery Department, Research Institute Codivilla-Putti, Rizzoli Orthopedic Institute, Bologna, Italy. paola.torricelli@ior.it
authors.forename: Paola
authors.initials: P
authors.lastname: Torricelli
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giavaresi
authors.forename: Roberto
authors.initials: R
authors.lastname: Giardino
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000601:Amino Acids, Essential / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology; D015415:Biomarkers / Q000032:analysis; D001851:Bone Diseases, Metabolic / Q000188:drug therapy / Q000473:pathology*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D005260:Female; D005270:Femur Head; D006801:Humans; D008239:Lysine / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects* / Q000473:pathology; D010024:Osteoporosis / Q000517:prevention & control
chemical_list: D000601:Amino Acids, Essential; D015415:Biomarkers; D001120:Arginine; D008239:Lysine