title: Metabolic and cytoprotective effects of in vivo peri-patellar hyaluronic acid injections in cultured tenocytes.
abstract: The purpose of this study was to investigate tenocyte mechanobiology after sudden-detraining and to examine the hypothesis that repeated peri-patellar injections of hyaluronic acid (HA) on detrained patellar tendon (PT) may reduce and limit detrained-associated damage in tenocytes. Twenty-four male Sprague-Dawley rats were divided into three groups: Untrained, Trained and Detrained. In the Detrained rats, the left tendon was untreated while the right tendon received repeated peri-patellar injections of either HA or saline (NaCl). Tenocyte morphology, metabolism and synthesis of C-terminal-propeptide of type I collagen, collagen-III, fibronectin, aggrecan, tenascin-c, interleukin-1β, matrix-metalloproteinase-1 and-3 were evaluated after 1, 3, 7 and 10 days of culture. Transmission-electronic-microscopy showed a significant increase in mitochondria and rough endoplasmic reticulum in cultured tenocytes from Detrained-HA with respect to those from Detrained-NaCl. Additionally, Detrained-HA cultures showed a significantly higher proliferation rate and viability, and increased synthesis of C-terminal-Propeptide of type I collagen, fibronectin, aggrecan, tenascin-c and matrix-metalloproteinase-3 with respect to Detrained-NaCl ones, whereas synthesis of matrix-metalloproteinase-1 and interleukin-1β was decreased. Our study demonstrates that discontinuing training activity in the short-term alters tenocyte synthetic and metabolic activity and that repeated peri-patellar infiltrations of HA during detraining allow the maintenance of tenocyte anabolic activity.
authors.affiliation: Laboratory of Biocompatibility, Technological Innovation and Advanced Therapy, Rizzoli RIT, Rizzoli Orthopedic Institute , Bologna , Italy .
authors.forename: F
authors.initials: F
authors.lastname: Salamanna
authors.forename: A
authors.initials: A
authors.lastname: Frizziero
authors.forename: S
authors.initials: S
authors.lastname: Pagani
authors.forename: G
authors.initials: G
authors.lastname: Giavaresi
authors.forename: D
authors.initials: D
authors.lastname: Curzi
authors.forename: E
authors.initials: E
authors.lastname: Falcieri
authors.forename: M
authors.initials: M
authors.lastname: Marini
authors.forename: P M
authors.initials: PM
authors.lastname: Abruzzo
authors.forename: L
authors.initials: L
authors.lastname: Martini
authors.forename: M
authors.initials: M
authors.lastname: Fini
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D019610:Cytoprotection / Q000187:drug effects*; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D018836:Inflammation Mediators / Q000378:metabolism; D007267:Injections; D008297:Male; D010329:Patella / Q000187:drug effects*; D014176:Protein Biosynthesis / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology; D019063:Tenascin; D013710:Tendons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D019063:Tenascin; D012965:Sodium Chloride; D006820:Hyaluronic Acid
keywords: Detraining; hyaluronic acid; patellar tendon; rats; tenocytes