Elucidation of the functional roles of Ca2+-activated potassium channels in osteoclastic bone resorption

2015 Fiscal Year Final Research Report

• Project/Area Number: 25462907
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional basic dentistry
• Research Institution: Fukuoka Dental College
• Principal Investigator: OKAMOTO FUJIO 福岡歯科大学, 歯学部, 講師 (60153938)
• Co-Investigator(Kenkyū-buntansha): KAJIYA Hiroshi 福岡歯科大学, 口腔歯学部, 講師 (80177378) ; OKABE Koji 福岡歯科大学, 口腔歯学部, 教授 (80224046)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 骨代謝 / 破骨細胞 / カルシウム活性化カリウムチャネル / ＴＲＰチャネル / 骨吸収

Outline of Final Research Achievements

We investigated the functional role of Ca2+-activated K+ channels (Kca) in osteoclastic bone resorption. Mature osteoclasts derived from mouse bone marrow cells abundantly expressed Kca 3.1. Pharmacological inhibition of Kca 3.1 led to rapid disappearance of ring-like actin conformation (actin-ring) and reduced bone resorption activity. Other Kca blockers had no effect on both the actin-ring conformation and the bone resorption activity. Mature osteoclasts also expressed non-selective cation channels including TRPM7. Inhibition of these cation channels also reduced the bone resorption activity. These results suggest that Kca 3.1 expressed in mature osteoclasts serves as a regulator of Ca2+ influx through the non-selective cation channels, which contribute to the formation of actin-ring, an essential process for the bone resorption.

Free Research Field

口腔生理学