• 한국유가공학회:학술대회논문집
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• 한국유가공기술과힉회 2007년도 추계학술발표대회
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• pp.39-47
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• 2007

골은 지속적으로 재형성이 일어나며, 오래된 골을 흡수하는 파골세포와 새로운 골을 생성하는 조골세포의 균형에 의하여 항상성이 유지된다. 골대사의 건전성을 측정하기 위한 골흡수 표시자에는 tartrate resistant acid phosphatase, pyridinium 연결부위, 콜라겐 telopeptide 등이 있으며, 골 형성 표시자로는 골 유래 alkaline phosphatase, osteocalcin, procollagen I extension peptide를 사용할 수 있다. 골밀도를 증진하기 위한 기능성 소재로는 milk basic protein, lactoferrin 등이 있으며, 우유의 유산균 발효과정에 의하여 생산되는 생리활성 펩타이드도 골밀도의 증진에 기여할 수 있다. Lactobacillus casei ATCC 393을 이용하여 생산한 발효분해물은 다양한 조골세포의 생화학적 지표 평가와 동물실험 결과를 근거로 할 때 조골세포의 증식과 분화를 촉진하고 파골세포의 활성을 억제시킴으로써 골대사를 개선할 수 있는 것으로 나타났다.

• International Journal of Oral Biology
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• 제36권4호
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• pp.173-178
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• 2011

Tumor necrosis factor alpha ($TNF{\alpha}$) is a multifunctional cytokine that is elevated in inflammatory diseases such as atherosclerosis, diabetes and rheumatoid arthritis. Recent evidence has suggested that ${\beta}2$ adrenergic receptor (${\beta}2AR$) activation in osteoblasts suppresses osteogenic activity. In the present study, we explored whether $TNF{\alpha}$ modulates ${\beta}AR$ expression in osteoblastic cells and whether this regulation is associated with the inhibition of osteoblast differentiation by $TNF{\alpha}$. In the experiments, we used C2C12 cells, MC3T3-E1 cells and primary cultured mouse bone marrow stromal cells. Among the three subtypes of ${\beta}AR$, ${\beta}2$ and ${\beta}3AR$ were found in our analysis to be upregulated by $TNF{\alpha}$. Moreover, isoproterenol-induced cAMP production was observed to be significantly enhanced in $TNF{\alpha}$-primed C2C12 cells, indicating that $TNF{\alpha}$ enhances ${\beta}2AR$ signaling in osteoblasts. $TNF{\alpha}$ was further found in C2C12 cells to suppress bone morphogenetic protein 2-induced alkaline phosphatase (ALP) activity and the expression of osteogenic marker genes including Runx2, ALP and osteocalcin. Propranolol, a ${\beta}2AR$ antagonist, attenuated this $TNF{\alpha}$ suppression of osteogenic differentiation. $TNF{\alpha}$ increased the expression of receptor activator of NF-${\kappa}B$ ligand (RANKL), an essential osteoclastogenic factor, in C2C12 cells which was again blocked by propranolol. In summary, our data show that $TNF{\alpha}$ increases ${\beta}2AR$ expression in osteoblasts and that a blockade of ${\beta}2AR$ attenuates the suppression of osteogenic differentiation and stimulation of RANKL expression by $TNF{\alpha}$. These findings imply that a crosstalk between $TNF{\alpha}$ and ${\beta}2AR$ signaling pathways might occur in osteoblasts to modulate their function.