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(-)-Epigallocatechin gallate amplifies interleukin-1-stimulated interleukin-6 synthesis in osteoblast-like MC3T3-E1 cells. Biochimie 2013; 95:1933-8. [DOI: 10.1016/j.biochi.2013.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 07/02/2013] [Indexed: 11/19/2022]
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2
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Kondo A, Otsuka T, Matsushima-Nishiwaki R, Kuroyanagi G, Mizutani J, Wada I, Kozawa O, Tokuda H. Inhibition of SAPK/JNK leads to enhanced IL-1-induced IL-6 synthesis in osteoblasts. Arch Biochem Biophys 2013; 535:227-33. [PMID: 23624146 DOI: 10.1016/j.abb.2013.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/07/2013] [Accepted: 04/01/2013] [Indexed: 10/26/2022]
Abstract
Stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK)(1) which belongs to the MAP kinase superfamily regulates many cellular events. We previously reported that interleukin 1 (IL-1) stimulates the synthesis of interleukin 6 (IL-6) through activation of ERK and p38 MAP kinase in osteoblast-like MC3T3-E1 cells, and that AMP-activated protein kinase (AMPK) negatively regulates the IL-1-induced IL-6 synthesis through IκB/NF-κB pathway. In the present study, we investigated the role of SAPK/JNK in the IL-1-stimulated IL-6 synthesis in these cells. IL-1 induced the phosphorylation of SAPK/JNK. SP600125, an inhibitor of SAPK/JNK, increased the release and the mRNA expression levels of IL-6 induced by IL-1. IL-1-stimulated IL-6 release was significantly up-regulated in SAPK/JNK-knocked down cells. SP600125 remarkably suppressed the IL-1-induced phosphorylation of both IκB and NF-κB, whereas SP600125 failed to affect the IL-1-induced phosphorylation of AMPK, STAT3 or Src. Compound C, an AMPK inhibitor, attenuated the IL-1-induced phosphorylation of SAPK/JNK. SP600125 enhanced IL-1-stimulated IL-6 release also in normal human osteoblasts. These results strongly suggest that SAPK/JNK negatively regulates IL-1-stimulated IL-6 synthesis and acts at the point between AMPK and IκB/NF-κB in osteoblasts.
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Affiliation(s)
- Akira Kondo
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan
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3
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Kato K, Tokuda H, Matsushima-Nishiwaki R, Natsume H, Kondo A, Ito Y, Kozawa O, Otsuka T. AMPK limits IL-1-stimulated IL-6 synthesis in osteoblasts: involvement of IκB/NF-κB pathway. Cell Signal 2012; 24:1706-12. [PMID: 22560875 DOI: 10.1016/j.cellsig.2012.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/09/2012] [Accepted: 04/18/2012] [Indexed: 01/20/2023]
Abstract
AMP-activated protein kinase (AMPK) is currently known to act as a key regulator of metabolic homeostasis. Several biosynthetic enzymes for fatty acid or glycogen are recognized as the targets of AMPK. In the present study, we investigated the role of AMPK in the interleukin-1 (IL-1)-stimulated IL-6 synthesis in osteoblast-like MC3T3-E1 cells. IL-1 induced phosphorylation of AMPK-α (Thr-172), which regulates AMPK activities, and acetyl-CoA carboxylase, a direct substrate of AMPK. Compound C, an inhibitor of AMPK, which suppressed the IL-1-induced phosphorylation of acetyl-CoA carboxylase, increased the release and the mRNA level of IL-6 stimulated by IL-1. Transfection of AMPK siRNA-α also amplified the IL-1-stimulated IL-6 release compared to the control cells. On the other hand, IL-1 elicited the phosphorylation of IκB, which caused subsequent decrease of total level of IκB. Wedelolactone, an inhibitor of IκB kinase, which reduced the phosphorylation both of IκB and NF-κB, significantly enhanced the IL-1-stimulated IL-6 synthesis. Compound C remarkably suppressed the IL-1-induced phosphorylation of IκB. These results strongly suggest that AMPK negatively regulates IL-1-stimulated IL-6 synthesis through the IκB/NF-κB pathway in osteoblasts.
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Affiliation(s)
- Kenji Kato
- Department of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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4
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Lin FH, Chang JB, Brigman BE. Role of mitogen-activated protein kinase in osteoblast differentiation. J Orthop Res 2011; 29:204-10. [PMID: 20806320 DOI: 10.1002/jor.21222] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Accepted: 06/18/2010] [Indexed: 02/04/2023]
Abstract
Local control of osteoblast differentiation and bone formation is not well understood. We have previously seen biphasic effects on cell differentiation in response to the short- and long-term exposure to IL-1β in rat calvarial osteoblasts. To characterize the signaling pathway mechanisms regulating IL-1β biphasic effects, we examined the contribution of mitogen-activated protein kinase (MAPK) family. Cells were pretreated with specific inhibitors to extracellular signal-regulated kinase (ERK, PD98059), p38 (SB203580), and c-JUN N-terminal kinase (JNK, SP600125), then co-cultured with IL-1β for 2, 4, and 6 days. Cell differentiation was determined by measuring bone nodules after 10 days of culture. These inhibitors did not alter biphasic effects of IL-1β on cell differentiation. However, PD98059 and U2016, another inhibitor of ERK activation robustly increased osteoblast differentiation compared to vehicle-treated control in a time- and dose-dependent manner. PD98059 appears to stimulate alkaline phosphatase (ALP) activity to promote cell differentiation, where IL-1β appears to suppress it. Interestingly, continuous ERK inhibition with PD98059, after 2 and 4 days of IL-1β treatment, enhanced the IL-1β anabolic effect by increasing bone nodules formed. These observations provide a potential mechanism involving ERK pathway in osteoblasts differentiation and suggest that MAPK family may not directly regulate IL-1β biphasic effects.
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Affiliation(s)
- Fu-Hsiung Lin
- Division of Orthopaedic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
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5
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Zídek Z, Anzenbacher P, Kmonícková E. Current status and challenges of cytokine pharmacology. Br J Pharmacol 2009; 157:342-61. [PMID: 19371342 PMCID: PMC2707982 DOI: 10.1111/j.1476-5381.2009.00206.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 01/13/2009] [Accepted: 01/19/2009] [Indexed: 12/12/2022] Open
Abstract
The major concern of pharmacology about cytokines has originated from plentiful data showing association between gross changes in their production and pathophysiological processes. Despite the enigmatic role of cytokines in diseases, a number of them have become a subject of cytokine and anti-cytokine immunotherapies. Production of cytokines can be influenced by many endogenous and exogenous stimuli including drugs. Cells of the immune system, such as macrophages and lymphocytes, are richly endowed with receptors for the mediators of physiological functions, such as biogenic amines, adenosine, prostanoids, steroids, etc. Drugs, agonists or antagonists of these receptors can directly or indirectly up- and down-regulate secretion of cytokines and expression of cytokine receptors. Vice versa, cytokines interfere with drug pharmacokinetics and pharmacodynamics through the interactions with cytochrome P450 and multiple drug resistance proteins. The aim of the review is to encourage more intensive studies in these fields of cytokine pharmacology. It also outlines major areas of searching promising candidates for immunotherapeutic interventions.
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Affiliation(s)
- Z Zídek
- Department of Pharmacology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, v.v.i., Vídenská 1083, 142 20 Prague 4, Czech Republic.
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6
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Ishino H, Kawahito Y, Tsubouchi Y, Kohno M, Wada M, Yamamoto A, Hamaguchi M, Kadoya M, Tokunaga D, Hojo T, Matsuyama M, Yoshimura R, Yoshikawa T. Feedback Control of the Arachidonate Cascade in Osteoblastic Cells by 15-deoxy-Delta-Prostaglandin J(2). J Clin Biochem Nutr 2008; 42:64-9. [PMID: 18231633 PMCID: PMC2212349 DOI: 10.3164/jcbn.2008011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 08/13/2007] [Indexed: 11/22/2022] Open
Abstract
15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and an anti-diabetic thiazolidinedione, troglitazone (TRO) are peroxisome proliferator-activated receptor (PPAR)-γ ligands, which regulate immuno-inflammatory reactions as well as adipocyte differentiation. We previously reported that 15d-PGJ2 can suppress interleukin (IL)-1β-induced prostaglandin E2 (PGE2) synthesis in synoviocytes of rheumatoid arthritis (RA). IL-1 also stimulates PGE2 synthesis in osteoblasts by regulation of cyclooxygenase (COX)-2 and regulates osteoclastic bone resorption in various diseases such as RA and osteoporosis. In this study, we investigated the feedback mechanism of the arachidonate cascade in mouse osteoblastic cells, MC3T3-E1 cells, which differentiate into mature osteoblasts. Treatment with 15d-PGJ2 led to a significant increase in IL-1α-induced COX-2 expression and PGE2 production in a dose dependent manner. The effect of 15d-PGJ2 was stronger than that of TRO. However, it did not affect the expression of COX-1. In addition, cell viability of MC3T3-E1 cells was not changed in the condition we established. This means that 15d-PGJ2 exerts a positive feedback regulation of the arachidonate cascade of PGE2 in osteoblastic cells. These results may provide important information about the pathogenesis and treatment of bone resorption in a variety of diseases such as RA and osteoporosis.
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Affiliation(s)
- Hidetaka Ishino
- Inflammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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7
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Mbalaviele G, Monahan JB. Mechanisms of the joint-protective effects of p38 MAPK inhibitors in rodent arthritis. Expert Opin Drug Discov 2008; 3:163-72. [DOI: 10.1517/17460441.3.2.163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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8
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Sun YH, Liu MN, Li H, Shi S, Zhao YJ, Wang R, Xu CQ. Calcium-sensing receptor induces rat neonatal ventricular cardiomyocyte apoptosis. Biochem Biophys Res Commun 2006; 350:942-8. [PMID: 17046714 DOI: 10.1016/j.bbrc.2006.09.142] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 09/25/2006] [Indexed: 11/29/2022]
Abstract
The calcium-sensing receptor (CaSR) exists in many tissues, and its expression has been identified in rat cardiac tissue. However, the physiological importance and pathophysiological involvement of CaSR in homeostatic regulation of cardiac function are unclear. To investigate the relation of CaSR and apoptosis in cardiomyocytes, we examined the role of the CaSR activator gadolinium chloride (GdCl(3)) in rat neonatal ventricular cardiomyocytes. Expression of the CaSR protein was observed by Western blot. The apoptotic ratio of rat neonatal ventricular cardiomyocytes was measured with flow cytometry and immunofluorescence techniques. A laser scan confocal microscope was used to detect the intracellular concentration of calcium ([Ca(2+)](i)) in rat neonatal ventricular cardiomyocytes using the acetoxymethyl ester of fluo-3 (fluo-3/(AM)) as a fluorescent dye. The results showed that GdCl(3) increased the phosphorylation of extracellular signal-regulated protein kinase (ERK), c-Jun NH(2)-terminal protein kinases (JNK), and p38. GdCl(3) also activated caspase 9 and increased apoptosis in myocyte by increasing [Ca(2+)](i). In conclusion, these results suggest that CaSR promotes cardiomyocyte apoptosis in rat neonatal ventricular cardiomyocytes through activation of mitogen-activated protein kinases and caspase 9 signaling pathways.
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Affiliation(s)
- Yi-hua Sun
- Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
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9
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Tokuda H, Kanno Y, Ishisaki A, Takenaka M, Harada A, Kozawa O. Interleukin (IL)-17 enhances tumor necrosis factor-alpha-stimulated IL-6 synthesis via p38 mitogen-activated protein kinase in osteoblasts. J Cell Biochem 2005; 91:1053-61. [PMID: 15034939 DOI: 10.1002/jcb.20004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Inflammatory cytokines are well known to play crucial roles in the pathogenesis of rheumatoid arthritis. Among them, interleukin (IL)-17 is a cytokine that is mainly synthesized by activated T cells and its receptors are present in osteoblasts. The synthesis of IL-6, known to stimulate osteoclastic bone resorption, is reportedly responded to bone resorptive agents such as tumor necrosis factor-alpha (TNF-alpha) in osteoblasts. It has been reported that IL-17 enhances TNF-alpha-stimulated IL-6 synthesis in osteoblast-like MC3T3-E1 cells. We previously showed that sphingosine 1-phosphate (S1-P) mediates TNF-alpha-stimulated IL-6 synthesis in these cells. In the present study, we investigated the mechanism of IL-17 underlying enhancement of IL-6 synthesis in MC3T3-E1 cells. IL-17 induced phosphorylation of p38 mitogen-activated protein (MAP) kinase. SB203580 and PD169316, specific inhibitors of p38 MAP kinase, significantly reduced the enhancement by IL-17 of TNF-alpha-stimulated IL-6 synthesis. IL-17 also amplified S1-P-stimulated IL-6 synthesis, and the amplification by IL-17 was suppressed by SB203580. Anisomycin, an activator of p38 MAP kinase, which alone had no effect on IL-6 level, enhanced the IL-6 synthesis stimulated by TNF-alpha. SB203580 and PD169316 inhibited the amplification by anisomycin of the TNF-alpha-induced IL-6 synthesis. Taken together, our results strongly suggest that IL-17 enhances TNF-alpha-stimulated IL-6 synthesis via p38 MAP kinase activation in osteoblasts.
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Affiliation(s)
- Haruhiko Tokuda
- Department of Internal Medicine, Chubu National Hospital, National Institute for Longevity Sciences, Obu, Japan
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10
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Qian D, Lin HY, Wang HM, Zhang X, Liu DL, Li QL, Zhu C. Normoxic induction of the hypoxic-inducible factor-1 alpha by interleukin-1 beta involves the extracellular signal-regulated kinase 1/2 pathway in normal human cytotrophoblast cells. Biol Reprod 2004; 70:1822-7. [PMID: 14960485 DOI: 10.1095/biolreprod.103.025031] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
During early pregnancy, an environment of relative low oxygen tension is essential for normal embryonic and placental vasculature. In low-oxygen conditions, the hypoxic-inducible factor-1 (HIF-1), composed of alpha and beta subunits, controls the expression of a number of genes such as vascular endothelial growth factor (VEGF), a key angiogenic factor. The recent studies in some tumor cells have found that the labile component, HIF-1 alpha, is not only activated by hypoxia but also by peptides such as interleukin-1 (IL-1) in normoxia. In this article, we demonstrated that exposure of normal human cytotrophoblast cells to IL-1 beta stimulated the expression of HIF-1 alpha protein. Meanwhile, IL-1 beta also induced the secretion of VEGF in normal human cytotrophoblast cells. Our data indicated that IL-1 beta induced extracellular signal-regulated kinase (ERK) 1/2 phosphorylation. Moreover, treatment of cells with PD98059, an inhibitor of ERK1/2 signaling, inhibited the stimulation of HIF-1 alpha protein expression and VEGF secretion by IL-1 beta. These data indicate that, in normal human cytotrophoblast cells, IL-1 beta induces HIF- 1 alpha-mediated VEGF secretion and that IL-1 beta-stimulated ERK1/2 activation may be involved in this process.
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Affiliation(s)
- Dong Qian
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
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11
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Kirkwood K, Martin T, Andreadis ST, Kim YJ. Chemically modified tetracyclines selectively inhibit IL-6 expression in osteoblasts by decreasing mRNA stability. Biochem Pharmacol 2003; 66:1809-19. [PMID: 14563491 DOI: 10.1016/s0006-2952(03)00450-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In bone biology, interleukin (IL)-6 is an autocrine/paracrine cytokine which can induce osteoclasts formation and activation to help mediate inflammatory bone destruction. Previous studies have shown that tetracycline and its derivatives have potentially beneficial therapeutic effects in the prevention and treatment of metabolic bone diseases by modulating osteoblast and osteoclast activities. Our previous studies indicated that non-antimicrobial chemically modified tetracyclines (CMTs) can dose-dependently inhibit IL-1 beta-induced IL-6 secretion in osteoblastic cells. In the present study, we explored the molecular mechanisms underlying the ability of doxycycline analogs CMT-8 and its non-chelating pyrazole derivative, CMT-5 to affect IL-6 gene expression in murine osteoblasts. Steady-state IL-6 mRNA was decreased with CMT-8 (ca. 50%) but not by CMT-5 when stimulated by IL-1 beta. CMT-8 regulation of IL-1 beta-induced IL-6 gene expression was further explored. CMT-8 did not affect IL-6 promoter activity in reporter gene assays. However, the IL-6 mRNA stability was decreased in the presence of CMT-8. These effects require de novo protein synthesis as they were inhibited by cycloheximide. Western blot analysis indicated that CMT-8 did not affect p38 mitogen-activated protein kinase, c-jun NH(2)-terminal kinases, or extracellular signal-regulated kinases (1 and 2) phosphorylation in response to IL-1 beta. These data suggest that CMT-8 can modulate inhibit IL-1 beta-induced IL-6 expression in MC3T3-E1 cells at the post-transcriptional level affecting IL-6 mRNA stability. These observations may offer a novel molecular basis for this treatment of metabolic bone diseases that are mediated by IL-6.
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Affiliation(s)
- Keith Kirkwood
- Department of Periodontics and Endodontics, State University of New York at Buffalo, 250 Squire Hall, 3435 Main Street, Buffalo, NY 14214-3008, USA.
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12
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Tokuda H, Hatakeyama D, Shibata T, Akamatsu S, Oiso Y, Kozawa O. p38 MAP kinase regulates BMP-4-stimulated VEGF synthesis via p70 S6 kinase in osteoblasts. Am J Physiol Endocrinol Metab 2003; 284:E1202-9. [PMID: 12637256 DOI: 10.1152/ajpendo.00300.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously reported that p70 S6 kinase takes part in bone morphogenetic protein-4 (BMP-4)-stimulated vascular endothelial growth factor (VEGF) synthesis in osteoblast-like MC3T3-E1 cells. Recently, we showed that BMP-4-induced osteocalcin synthesis is regulated by p44/p42 MAP kinase and p38 MAP kinase in these cells. In the present study, we investigated whether the MAP kinases are involved in the BMP-4-stimulated synthesis of VEGF in MC3T3-E1 cells. PD-98059 and U-0126, inhibitors of the upstream kinase of p44/p42 MAP kinase, failed to affect BMP-4-stimulated VEGF synthesis. SB-203580 and PD-169316, inhibitors of p38 MAP kinase, significantly reduced VEGF synthesis, whereas SB-202474, a negative control for p38 MAP kinase inhibitor, had little effect on VEGF synthesis. The BMP-4-stimulated phosphorylation of p38 MAP kinase was not affected by rapamycin, an inhibitor of p70 S6 kinase. On the contrary, SB-203580 and PD-169316 reduced the BMP-4-stimulated phosphorylation of p70 S6 kinase. In addition, anisomycin, an activator of p38 MAP kinase, phosphorylates p70 S6 kinase, and the phosphorylation was suppressed by SB-203580. LY-294002, an inhibitor of phosphatidylinositol 3-kinase, failed to suppress the phosphorylation of p38 MAP kinase induced by BMP-4. Not BMP-4 but anisomycin weakly induced the phosphorylation of phosphoinositide-dependent kinase-1. However, anisomycin had little effect on phosphorylation of either Akt or the mammalian target of rapamycin. Taken together, our results suggest that p38 MAP kinase functions in BMP-4-stimulated VEGF synthesis as a positive regulator at a point upstream from p70 S6 kinase in osteoblasts.
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Affiliation(s)
- Haruhiko Tokuda
- Department of Internal Medicine, Chubu National Hospital, National Institute for Longevity Sciences, Obu, Aichi 474-8511, Japan
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13
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Kozawa O, Hatakeyama D, Tokuda H, Oiso Y, Matsuno H, Uematsu T. Sphingomyelinase amplifies BMP-4-induced osteocalcin synthesis in osteoblasts: role of ceramide. Cell Signal 2002; 14:999-1004. [PMID: 12359305 DOI: 10.1016/s0898-6568(02)00033-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We previously reported that extracellular sphingomyelinase induces sphingomyelin hydrolysis in osteoblast-like MC3T3-E1 cells and that mitogen-activated protein (MAP) kinases are involved in bone morphogenetic protein (BMP)-4-stimulated osteocalcin synthesis in these cells. In the present study, we investigated whether sphingomyelinase affects BMP-4-stimulated synthesis of osteocalcin in osteoblast-like MC3T3-E1 cells. Sphingomyelinase significantly enhanced the BMP-4-stimulated osteocalcin synthesis. Among sphingomyelin metabolites, C(2)-ceramide enhanced the BMP-4-stimulated osteocalcin synthesis while sphingosine and sphingosine 1-phosphate had little effect on the synthesis. D-erythro-MAPP, an inhibitor of ceramidase, amplified the sphingomyelinase-effect on the osteocalcin synthesis. C(2)-ceramide suppressed the BMP-4-induced phosphorylation of p44/p42 MAP kinase, while having little effect on the phosphorylation of Smad1 and p38 MAP kinase. Taken together, our results strongly suggest that extracellular sphingomyelinase enhances the BMP-stimulated osteocalcin synthesis via ceramide in osteoblasts and that the effect of ceramide is exerted at a point upstream from p44/p42 MAP kinase.
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Affiliation(s)
- Osamu Kozawa
- Department of Pharmacology, Gifu University School of Medicine, Gifu 500-8705, Japan.
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14
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Nozawa Y, Nishihara K, Peek RM, Nakano M, Uji T, Ajioka H, Matsuura N, Miyake H. Identification of a signaling cascade for interleukin-8 production by Helicobacter pylori in human gastric epithelial cells. Biochem Pharmacol 2002; 64:21-30. [PMID: 12106602 DOI: 10.1016/s0006-2952(02)01030-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Infecting gastric epithelial cells with Helicobacter pylori (H. pylori) has been shown to induce interleukin-8 (IL-8) production, but the signal transduction mechanism leading to IL-8 production is not defined clearly. In the present study, we investigated the molecular mechanism responsible for H. pylori-induced IL-8 release in human gastric epithelial cells. IL-8 levels in culture supernatants were determined by an enzyme linked-immunosorbent assay. Extracellular signal-regulated kinase (ERK) activity was tested using an in vitro kinase assay, which measured the incorporation of [gamma-33P]ATP into a synthetic peptide that is a specific ERK substrate. ERK phosphorylation and IkappaBalpha degradation by H. pylori infection were assessed by western blotting. In MKN45 cells, H. pylori-induced IL-8 release in a time-dependent manner. This IL-8 release was abolished by treatment with intracellular Ca2+ chelators (BAPTA-AM and TMB-8) but not by EGTA or nifedipine. The Ca2+ ionophore A23187 also induced IL-8 release to an extent similar to that of H. pylori infection. Calmodulin inhibitors (W7 and calmidazolium) and tyrosine kinase inhibitors (genistein and ST638) completely blocked IL-8 release by H. pylori and A23187. PD98059, an ERK pathway inhibitor, completely abolished H. pylori-induced IL-8 release. Moreover, BAPTA-AM, calmidazolium, and genistein, but not nifedipine, suppressed the ERK activation induced by H. pylori infection. PD98059 as well as MG132, an NF-kappaB pathway inhibitor, blocked both IL-8 production and degradation of IkappaBalpha induced by H. pylori infection, whereas only PD98059 inhibited ERK activity in response to H. pylori. There was no significant difference between IL-8 production induced by the cagA positive wild-type strain and the cagA negative isogenic mutant strain of H. pylori; therefore, CagA is not involved in the IL-8 production pathway. H. pylori-induced IL-8 production is dominantly regulated by Ca2+/calmodulin signaling, and ERK plays an important role in signal transmission for the efficient activation of H. pylori-induced NF-kappaB activity, resulting in IL-8 production.
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Affiliation(s)
- Yoshihisa Nozawa
- Pharmacology Research Laboratory, Taiho Pharmaceutical Co., Ltd., 224-2 Ebisuno, Hiraishi, Kawauchi-cho, Tokushima, Japan.
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15
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Kozawa O, Otsuka T, Uematsu T. Leukemia inhibitory factor enhances bFGF-induced IL-6 synthesis in osteoblasts: involvement of JAK2/STAT3. Cell Signal 2002; 14:311-5. [PMID: 11858938 DOI: 10.1016/s0898-6568(01)00248-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We previously showed that basic fibroblast growth factor (bFGF) stimulates release of vascular endothelial growth factor (VEGF) and synthesis of interleukin-6 (IL-6) in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the effects of leukemia inhibitory factor (LIF) on the release of VEGF and IL-6 in these cells. LIF did not affect the bFGF-stimulated VEGF release. On the contrary, LIF, which alone had little effect on IL-6 release, significantly enhanced the bFGF-stimulated IL-6 release. The amplifying effect of LIF on the IL-6 release was dose dependent in the range between 0.01 and 10 ng/ml. AG490, an inhibitor of JAK2, suppressed the amplifying effect of LIF. LIF induced the phosphorylation of STAT3. AG490 inhibited the LIF-induced STAT3 phosphorylation. Taken together, our results strongly suggest that LIF enhances bFGF-stimulated IL-6 synthesis via JAK2/STAT3 pathway in osteoblasts.
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Affiliation(s)
- Osamu Kozawa
- Department of Pharmacology, Gifu University School of Medicine, 500-8705, Gifu, Japan.
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16
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Hatakeyama D, Kozawa O, Niwa M, Matsuno H, Ito H, Kato K, Tatematsu N, Shibata T, Uematsu T. Upregulation by retinoic acid of transforming growth factor-beta-stimulated heat shock protein 27 induction in osteoblasts: involvement of mitogen-activated protein kinases. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1589:15-30. [PMID: 11909638 DOI: 10.1016/s0167-4889(01)00183-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We investigated whether transforming growth factor-beta (TGF-beta) stimulates the induction of heat shock protein (HSP) 27 and HSP70 in osteoblast-like MC3T3-E1 cells and the mechanism underlying the induction. TGF-beta increased the level of HSP27 but had no effect on the HSP70 level. TGF-beta stimulated the accumulation of HSP27 dose-dependently, and induced an increase in the level of mRNA for HSP27. TGF-beta induced the phosphorylation of p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase. The HSP27 accumulation induced by TGF-beta was significantly suppressed by PD98059, an inhibitor of the upstream kinase of p44/p42 MAP kinase, or SB203580, an inhibitor of p38 MAP kinase. PD98059 and SB203580 suppressed the TGF-beta-stimulated increase in the level of mRNA for HSP27. Retinoic acid, a vitamin A (retinol) metabolite, which alone had little effect on the HSP27 level, markedly enhanced the HSP27 accumulation stimulated by TGF-beta. Retinoic acid enhanced the TGF-beta-induced increase of mRNA for HSP27. The amplification of TGF-beta-stimulated HSP27 accumulation by retinoic acid was reduced by PD98059 or SB203580. Retinoic acid failed to affect the TGF-beta-induced phosphorylation of p44/p42 MAP kinase or p38 MAP kinase. These results strongly suggest that p44/p42 MAP kinase and p38 MAP kinase take part in the pathways of the TGF-beta-stimulated HSP27 induction in osteoblasts, and that retinoic acid upregulates the TGF-beta-stimulated HSP27 induction at a point downstream from p44/p42 MAP kinase and p38 MAP kinase.
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Affiliation(s)
- Daijiro Hatakeyama
- Department of Pharmacology, Gifu University School of Medicine, Gifu, Japan
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Kozawa O, Hatakeyama D, Uematsu T. Divergent regulation by p44/p42 MAP kinase and p38 MAP kinase of bone morphogenetic protein-4-stimulated osteocalcin synthesis in osteoblasts. J Cell Biochem 2002. [DOI: 10.1002/jcb.10056] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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18
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Webb SJ, McPherson JR, Pahan K, Koka S. Regulation of TNF-alpha-induced IL-6 production in MG-63 human osteoblast-like cells. J Dent Res 2002; 81:17-22. [PMID: 11820362 DOI: 10.1177/002203450208100105] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha) stimulates osteoblast production of interleukin-6 (IL-6), an inflammatory cytokine implicated in osteoclastic bone resorption. Therefore, we tested the hypothesis that TNF-alpha-induced IL-6 production in MG-63 osteosarcoma cells occurs via the p38 mitogen-activated protein kinase (MAPK) pathway. TNF-alpha activated p38 MAPK and stimulated IL-6 secretion by MG-63 cells, and pre-incubation of cells with the p38 MAPK inhibitor abrogated TNF-alpha-dependent IL-6 secretion. Transfection of IL-6 full-length and 5-deletion gene promoter reporter constructs indicated that p38 MAPK activation by TNF-alpha enhanced IL-6 gene expression, and that the p38 MAPK-responsive region resided in the proximal 260-bp segment. Transfection of NFkappaB and C/EBPbeta-sensitive reporter promoter constructs demonstrated that NFkappaB activity was enhanced and that constitutive C/EBPbeta was inhibited by TNF-alpha, with both effects being p38 MAPK-dependent. In conclusion, although p38 MAPK activation by TNF-alpha stimulates IL-6 secretion by MG-63 cells, it has opposing effects on c/EBPbeta and NFkappaB activity.
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Affiliation(s)
- S J Webb
- Dept. of Oral Biology, UNMC, Lincoln, NE 68583, USA
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19
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Schupp P, Steube K, Meyer C, Proksch P. Anti-proliferative effects of new staurosporine derivatives isolated from a marine ascidian and its predatory flatworm. Cancer Lett 2001; 174:165-72. [PMID: 11689292 DOI: 10.1016/s0304-3835(01)00694-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nine indolocarbazole alkaloids of the staurosporine type, including three new derivatives, were evaluated for their potential as inhibitors of cell proliferation and macromolecule synthesis. Four derivatives were tested as inhibitors of cell proliferation with twelve human leukemia cell lines and demonstrated powerful antiproliferative activities, with 3-hydroxystaurosporine being the most potent. IC(50) values were determined using the cell line MONO-MAC-6 and with an IC(50) of 13 ng/ml, 3-hydroxystaurosporine turned out to be one of the most active staurosporine-type inhibitors described so far. All derivatives, except 3-hydroxy-3'-demethoxy-3'-hydroxystaurosporine and 4'-N-methylstaurosporine very strongly reduced RNA and DNA synthesis with 3-hydroxystaurosporine again being the strongest inhibitor. Analysis of structure-activity relationships demonstrated that hydroxylation of staurosporine at position 3 of the indolocarbazole moiety caused an increase in anti-proliferative activity, while hydroxylation at carbon 11 resulted in a decrease in activity. Our results suggest that not only the presence or absence of hydrophilic substitutions, but also the position of the alteration within the molecule, is important in the antiproliferative properties of the various staurosporine analogues.
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Affiliation(s)
- P Schupp
- Center for Marine Biofouling and Bio-Innovation, University of New South Wales, Sydney, 2052, Australia.
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Yosimichi G, Nakanishi T, Nishida T, Hattori T, Takano-Yamamoto T, Takigawa M. CTGF/Hcs24 induces chondrocyte differentiation through a p38 mitogen-activated protein kinase (p38MAPK), and proliferation through a p44/42 MAPK/extracellular-signal regulated kinase (ERK). EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:6058-65. [PMID: 11732999 DOI: 10.1046/j.0014-2956.2001.02553.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Connective tissue growth factor/hypertrophic chondrocyte specific gene product 24 (CTGF/Hcs24) promotes proliferation and differentiation of chondrocytes in culture. We investigated the roles of two major types of mitogen activated protein kinase (MAPK) in the promotion of proliferation and differentiation by CTGF/Hcs24. Here we report the effects of the MAPKK/MEK 1/2 inhibitor, PD098059, and p38 MAPK inhibitor, SB203580, in a human chondrosarcoma-derived chondrocytic cell line (HCS-2/8) and rabbit growth cartilage (RGC) cells treated with CTGF/Hcs24. In the proliferation phase, CTGF/Hcs24 induced a approximately fivefold increase in the phosphorylation of p44/42 MAPK/ERK and a approximately twofold increase in that of p38 MAPK in an in vivo kinase assay. These inhibitors of MAPKK and MAPK suppressed phosphorylation of ets-like gene-1 (Elk-1) and nuclear activating transcription factor-2 (Atf-2) induced by CTGF/Hcs24 in a dose-dependent manner, respectively. Western blot analysis showed that phosphorylation of ERK was induced from 30 to 60 min and phosphorylation of p38 MAPK from 10 to 15 min after the addition of CTGF/Hcs24 in confluence HCS-2/8 cells. PD098059 suppressed the DNA synthesis of HCS-2/8 cells and RGC cells, while SB203580 did not. On the other hand, the p38 MAPK inhibitor, SB203580, completely inhibited the CTGF/Hcs24-induced synthesis of proteoglycans in HCS-2/8 cells and RGC cells but the MEK1/2 inhibitor, PD098059, did not. These results suggest that ERK mediates the CTGF/Hcs24-induced proliferation of chondrocytes, and that p38 MAPK mediates the CTGF/Hcs24-induced differentiation of chondrocytes.
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Affiliation(s)
- G Yosimichi
- Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan
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Kozawa O, Matsuno H, Uematsu T. Involvement of p70 S6 kinase in bone morphogenetic protein signaling: vascular endothelial growth factor synthesis by bone morphogenetic protein-4 in osteoblasts. J Cell Biochem 2001; 81:430-6. [PMID: 11255225 DOI: 10.1002/1097-4644(20010601)81:3<430::aid-jcb1056>3.0.co;2-g] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In the present study, we investigated the effect of bone morphogenetic protein (BMP)-4 on the synthesis of vascular endothelial growth factor (VEGF) in osteoblast-like MC3T3-E1 cells. BMP-4 significantly stimulated VEGF synthesis time-dependently up to 48 h. The stimulatory effect was dose-dependent in the range between 1 and 100 ng/ml. BMP-4 time-dependently phosphorylated p70 S6 kinase. Rapamycin, an inhibitor of p70 S6 kinase, suppressed the BMP-4-stimulated VEGF synthesis as well as the phosphorylation of p70 S6 kinase. The VEGF synthesis by BMP-4 was suppressed by wortmannin and LY294002, inhibitors of phosphatidylinositol 3-kinase. Both wortmannin and LY294002 inhibited the BMP-4-stimulated phosphorylation of p70 S6 kinase. BMP-4 did not affect the phosphorylation of Akt/protein kinase B. Taken together, our results strongly suggest that p70 S6 kinase takes part in BMP-4-stimulated VEGF synthesis as a positive regulator in osteoblasts and that phosphatidylinositol 3-kinase acts at a point upstream from p70 S6 kinase.
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Affiliation(s)
- O Kozawa
- Department of Pharmacology, Gifu University School of Medicine, Gifu 500-8705, Japan
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Kifor O, MacLeod RJ, Diaz R, Bai M, Yamaguchi T, Yao T, Kifor I, Brown EM. Regulation of MAP kinase by calcium-sensing receptor in bovine parathyroid and CaR-transfected HEK293 cells. Am J Physiol Renal Physiol 2001; 280:F291-302. [PMID: 11208605 DOI: 10.1152/ajprenal.2001.280.2.f291] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Regulation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway by the extracellular calcium (Ca2+o)-sensing receptor (CaR) was investigated in bovine parathyroid and CaR-transfected human embryonic kidney (HEKCaR) cells. Elevating Ca2+o or adding the selective CaR activator NPS R-467 elicited rapid, dose-dependent phosphorylation of ERK1/2. These phosphorylations were attenuated by pretreatment with pertussis toxin (PTX) or by treatment with the phosphotyrosine kinase (PTK) inhibitors genistein and herbimycin, the phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitor U-73122, or the protein kinase C (PKC) inhibitor GF109203X and were enhanced by the PKC activator phorbol 12-myristate 13-acetate. Combined treatment with PTX and inhibitors of both PKC and PTK nearly abolished high Ca2+o-evoked ERK1/2 activation in HEKCaR cells, demonstrating CaR-mediated coupling via both Gq and G(i). High Ca2+o increased serine phosphorylation of the 85-kDa cytosolic phospholipase A2 (cPLA2) in both parathyroid and HEKCaR cells. The selective mitogen-activated protein kinase (MAPK) inhibitor PD98059 abolished high-Ca2+o)-induced ERK1/2 activation and reduced cPLA2 phosphorylation in both cell types, documenting MAPK's role in cPLA2 activation. Thus our data suggest that the CaR activates MAPK through PKC, presumably through Gq/11-mediated activation of PI-PLC, as well as through G(i)- and PTK-dependent pathway(s) in bovine parathyroid and HEKCaR cells and indicate the importance of MAPK in cPLA2 activation.
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Affiliation(s)
- O Kifor
- Endocrine-Hypertension Division and Membrane Biology Program, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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Schwartz Z, Lohmann CH, Vocke AK, Sylvia VL, Cochran DL, Dean DD, Boyan BD. Osteoblast response to titanium surface roughness and 1?,25-(OH)2D3 is mediated through the mitogen-activated protein kinase (MAPK) pathway. ACTA ACUST UNITED AC 2001; 56:417-26. [PMID: 11372060 DOI: 10.1002/1097-4636(20010905)56:3<417::aid-jbm1111>3.0.co;2-k] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
When osteoblasts are cultured on surfaces of increasing microroughness, they exhibit decreases in proliferation, increases in differentiation and local factor production, and enhanced response to 1alpha,25(OH)(2)D(3). The cells interact with surfaces through integrins, which signal by the same pathways used by 1alpha,25(OH)(2)D(3), including protein kinase C via phospholipase C and protein kinase A via phospholipase A(2). This provides opportunities for crosstalk that may contribute to the synergistic effects of surface roughness and the vitamin D metabolite. Because these pathways converge at mitogen-activated protein kinase (MAPK), we tested the hypothesis that the extracellular signal-regulated kinase (ERK1/2) subclass of MAPKs mediates the effects of surface roughness and 1alpha,25(OH)(2)D(3). MG63 osteoblast-like osteosarcoma cells were cultured on commercially pure Ti disks with various surface roughnesses: pretreatment (PT; 0.6 microm average roughness [Ra]), coarse grit-blasted and acid-etched (SLA; 4 microm RA), and titanium plasma-sprayed (TPS; 5.2-microm R(a)). At confluence, cells were treated for 24 h with control media or media containing 10(-7) M 1alpha,25(OH)(2)D(3). One-half of the cultures received 1 microm or 10 microm PD98059, a specific inhibitor of the ERK family of MAPKs. PD98059 alone did not affect proliferation, osteocalcin production, or production of transforming growth factor-beta1 or nitric oxide, regardless of the surface roughness. Alkaline phosphatase was reduced by the inhibition of the ERK family kinases on all surfaces to a comparable extent. However, when PD98059 was added to the cultures with 1alpha,25(OH)(2)D(3), the effects of the seco-steroid were blocked, including the synergistic increases seen in MG63 cells cultured on SLA or TPS. These results indicate that ERK1/2 MAPK is required for the maintenance of alkaline phosphatase at control levels and that the effects of 1alpha,25(OH)(2)D(3) are mediated by ERK1/2. However, the effects of surface roughness are not due to the ERK family of MAPKs. This suggests that alternative pathways may be used, including those mediated by other MAPK subclasses.
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Affiliation(s)
- Z Schwartz
- Department of Orthopaedics, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
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