1994 Fiscal Year Final Research Report Summary
Stimulatory effects of interleukin-4 on bone formation and its relation to low-turnover osteoporosis
| Project/Area Number |
05671244
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Tokyo metropolitan institute of gerontology |
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Principal Investigator |
KARUBE Shunji Tokyo metropolitan institute of gerontology, Department of biosignal research, research fellow, 酵素生化学部門, 研究員 (80260280)
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| Co-Investigator(Kenkyū-buntansha) |
KOSHIHARA Yasuko Tokyo metropolitan institute of gerontology, Department of biosignal research, r, 生体情報部門, 主任研究員 (20073025)
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| Project Period (FY) |
1993 – 1994
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| Keywords | INTERLEUKIN-4 / BONE FORMATION / LOW TURN-OVER OSTEOPOROSIS / DIFFERENTIAL DISPLAY / TYPE VI COLLAGEN |
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| Research Abstract |
In basic research of bone metabolism, mechanisms of regulation of osteoblasts and osteoclasts by somatic hormones and local cytokines are getting clear more and more. Low-turnover osteoporosis is defined as skeletal condition of older people with low levels of bone formation and bone resorption, but its pathogenesis remains to be elucidated. We hypothesize that the mechanism of changing balance of bone remodeling is involved not only with aging of bone cells but with aging of immunological and hematological systems. In 1990, it was reported that interleukin-4 (IL-4) reduced bone resorption in an organ culture system with murine femur. Since then, the effects of IL-4 on bone metabolism has been investigated. Recently, we found that treatment with IL-4 increased the amount of hydroxyproline, osteocalcin and calcium in a monolayr of cultured osteoblast-like cells. This result shows the stimulatory and anabolic effects of IL-4 on bone formation. The function of T lymphocyte, which releases IL-4 when activated, is weakened in older people. Taken together, IL-4 seems to have some relation to the onset and development of low-turnover osteoporosis. Then we searched mRNAs to be induced by IL-4 treatment in cultured osteoblast-like cells by the method of differential display of mRNAs. As a result, it is found that IL-4 stimulates gene expression of type VI collagen. This collagen has a high affinity with many kinds of adhesion molecules and matrix proteins. And its amount in bone diminish with aging. So, type VI collagen possibly mediates the effects of IL-4 on low-turnover osteoporosis.
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