AMP-activated protein kinase is involved in COX-2 expression in response to ultrasound in cultured osteoblasts
| Autor: | Tzu-Wei Tan, Chun-Han Hou, Chih-Hsin Tang |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
p38 mitogen-activated protein kinases
Gene Expression AMP-Activated Protein Kinases Protein Serine-Threonine Kinases Biology Transfection Models Biological p38 Mitogen-Activated Protein Kinases Cell Line AMP-Activated Protein Kinase Kinases NF-KappaB Inhibitor alpha AMP-activated protein kinase Multienzyme Complexes Humans Ultrasonics Phosphorylation RNA Small Interfering Kinase activity Protein kinase A Osteoblasts Base Sequence NF-kappa B AMPK Cell Biology I-kappa B Kinase Cell biology Cytosol Cyclooxygenase 2 biology.protein I-kappa B Proteins Signal transduction Signal Transduction |
| Zdroj: | Cellular Signalling. 20:978-988 |
| ISSN: | 0898-6568 |
| DOI: | 10.1016/j.cellsig.2008.01.013 |
| Popis: | It has been shown that ultrasound (US) stimulation accelerates fracture healing in the animal models and in clinical studies. Cyclooxygenase-2 (COX-2) is a crucial mediator in mechanically induced bone formation. AMP-activated protein kinase (AMPK) has reported to sense and regulate the cellular energy status in various cell types. Here we found that US-mediated COX-2 expression was attenuated by LKB1 and AMPKalpha1 small interference RNA (siRNA) in human osteoblasts. Pretreatment of osteoblasts with AMPK inhibitor (araA and compound C), p38 inhibitor (SB203580), NF-kappaB inhibitor (PDTC), IkappaB protease inhibitor (TPCK) and NF-kappaB inhibitor peptide also inhibited the potentiating action of US. US increased the kinase activity and phosphorylation of LKB1, AMPK and p38. Stimulation of osteoblasts with US activated IkappaB kinase alpha/beta (IKKalpha/beta), IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 phosphorylation at Ser(276), p65 and p50 translocation from the cytosol to the nucleus, and kappaB-luciferase activity. US-mediated an increase of IKKalpha/beta activity, kappaB-luciferase activity and p65 and p50 binding to the NF-kappaB element was inhibited by araA, SB203580 and LKB1 siRNA. Our results suggest that US increased COX-2 expression in osteoblasts via the LKB1/AMPKalpha1/p38/IKKalphabeta and NF-kappaB signaling pathway. |
| Databáze: | OpenAIRE |
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