Self-sustained and entrainable circadian clock exists in the femur.

2014 Fiscal Year Final Research Report

• Project/Area Number: 25861335
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Orthopaedic surgery
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: MINAMI Yoichi 京都府立医科大学, 医学(系)研究科(研究院), 助教 (40415310)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 概日時計 / 発光イメージング / 軟骨 / 器官培養

Outline of Final Research Achievements

We identified that the circadian clock exists in the femur using PER2::Luc knock-in mice. The bioluminescence obtained from organ cultured femur showed clear about 24-hr rhythms over 5days. In continuous culture, the circadian rhythm of the bioluminescence was observed over 9months. High- or low-magnification real-time bioluminescence microscopic imaging revealed that the robust circadian rhythms emanated from the articular cartilage and the epiphyseal cartilage within the growth plate. By adding forskolin or dexamethasone, the circadian clock was phase shifted in a stimulation time-dependent manner. These data strongly suggest that tissue-autonomous and entrainable circadian clock exists in the femur.
Parathyroid hormone (PTH) is a peptide hormone which plays important roles in bone metabolism. We found that PTH reset the circadian clock of the organ cultured femur. The PTH induced phase shift was occurred both dose-dependent and stimulation time-dependent manner.

Free Research Field

時間生物学