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AP-1 stimulates the cathepsin K promoter in RAW 264.7 cells.
Gene. 2007 Nov 15; 403(1-2):151-8.GENE

Abstract

Cathepsin K (CTSK) is a secreted protease that plays an essential role in osteoclastic bone resorption, and CTSK levels increase with osteoclast differentiation and activation, a process that is controlled by a complex physiological network of hormones and cytokines. A critical regulator of this process is receptor activator of NF-kappaB ligand (RANKL), a member of the tumor necrosis factor (TNF) superfamily of cytokines that can act via the TNF receptor activating factor (TRAF6)/AP-1 signaling pathway. However, the mechanism whereby RANKL modulates CTSK expression is not fully understood. Therefore, we investigated the regulation of CTSK expression and promoter activity in RAW 264.7 osteoclast precursor cells, which can be readily differentiated to osteoclasts upon RANKL stimulation. Western blot analysis, real-time RT-PCR and luciferase reporter gene assays revealed that RANKL stimulated CTSK expression and promoter activity in a dose- and time-dependent manner and that this activation was inhibited by either dominant negative (DN) TRAF6 or DN-c-fos. TRAF6 stimulated the basal activity of a truncated CTSK promoter, and DN-c-fos blocked this stimulation. JunB alone also stimulated basal CTSK promoter activity, whereas c-jun, JunD or c-fos alone did not. However, co-transfection of any of these jun-family members with c-fos (AP-1) significantly increased CTSK promoter expression. siRNA targeted against c-jun or junB suppressed RANKL-mediated CTSK expression. Therefore, both TRAF6 and AP-1 help regulate the basal and RANKL-mediated stimulation of CTSK gene expression in RAW 264.7 cells.

Authors+Show Affiliations

Geriatrics Research, Education and Clinical Center & Research Service, Miami Veterans Affairs Medical Center, Miami FL 33125, United States.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

17897792

Citation

Pang, Manhui, et al. "AP-1 Stimulates the Cathepsin K Promoter in RAW 264.7 Cells." Gene, vol. 403, no. 1-2, 2007, pp. 151-8.
Pang M, Martinez AF, Fernandez I, et al. AP-1 stimulates the cathepsin K promoter in RAW 264.7 cells. Gene. 2007;403(1-2):151-8.
Pang, M., Martinez, A. F., Fernandez, I., Balkan, W., & Troen, B. R. (2007). AP-1 stimulates the cathepsin K promoter in RAW 264.7 cells. Gene, 403(1-2), 151-8.
Pang M, et al. AP-1 Stimulates the Cathepsin K Promoter in RAW 264.7 Cells. Gene. 2007 Nov 15;403(1-2):151-8. PubMed PMID: 17897792.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - AP-1 stimulates the cathepsin K promoter in RAW 264.7 cells. AU - Pang,Manhui, AU - Martinez,Ariel F, AU - Fernandez,Isabel, AU - Balkan,Wayne, AU - Troen,Bruce R, Y1 - 2007/08/25/ PY - 2007/03/08/received PY - 2007/07/03/revised PY - 2007/08/10/accepted PY - 2007/9/28/pubmed PY - 2007/12/6/medline PY - 2007/9/28/entrez SP - 151 EP - 8 JF - Gene JO - Gene VL - 403 IS - 1-2 N2 - Cathepsin K (CTSK) is a secreted protease that plays an essential role in osteoclastic bone resorption, and CTSK levels increase with osteoclast differentiation and activation, a process that is controlled by a complex physiological network of hormones and cytokines. A critical regulator of this process is receptor activator of NF-kappaB ligand (RANKL), a member of the tumor necrosis factor (TNF) superfamily of cytokines that can act via the TNF receptor activating factor (TRAF6)/AP-1 signaling pathway. However, the mechanism whereby RANKL modulates CTSK expression is not fully understood. Therefore, we investigated the regulation of CTSK expression and promoter activity in RAW 264.7 osteoclast precursor cells, which can be readily differentiated to osteoclasts upon RANKL stimulation. Western blot analysis, real-time RT-PCR and luciferase reporter gene assays revealed that RANKL stimulated CTSK expression and promoter activity in a dose- and time-dependent manner and that this activation was inhibited by either dominant negative (DN) TRAF6 or DN-c-fos. TRAF6 stimulated the basal activity of a truncated CTSK promoter, and DN-c-fos blocked this stimulation. JunB alone also stimulated basal CTSK promoter activity, whereas c-jun, JunD or c-fos alone did not. However, co-transfection of any of these jun-family members with c-fos (AP-1) significantly increased CTSK promoter expression. siRNA targeted against c-jun or junB suppressed RANKL-mediated CTSK expression. Therefore, both TRAF6 and AP-1 help regulate the basal and RANKL-mediated stimulation of CTSK gene expression in RAW 264.7 cells. SN - 0378-1119 UR - https://www.unboundmedicine.com/medline/citation/17897792/AP_1_stimulates_the_cathepsin_K_promoter_in_RAW_264_7_cells_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0378-1119(07)00435-0 DB - PRIME DP - Unbound Medicine ER -