In-Jin Cho1, Kyoung Hee Choi1, Chi Hyuk Oh1, You Cheol Hwang1, In-Kyung Jeong1, Kyu Jeung Ahn1, Ho-Yeon Chung2. 1. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Republic of Korea. 2. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Republic of Korea. Electronic address: chunghoyeon@khu.ac.kr.
Abstract
AIMS: Inflammatory processes are involved in bone remodeling. C-reactive protein (CRP) is an acute phase reactant that reflects different degrees of inflammation. Accumulating evidence suggests that CRP is an inflammatory marker and a direct cause of disease. Therefore, we examined the direct effects of CRP on bone cells. MAIN METHODS: We used RAW 264.7 cells to evaluate the direct effects of CRP on osteoclast differentiation. We carried out alkaline phosphatase (ALP) and bone nodule formation assays using MC3T3-E1 cells to evaluate osteoblast differentiation. Expression of osteoclast-specific and osteoblast-specific genes and effects on cell signaling pathways associated with cell differentiation were analyzed by reverse transcription polymerase chain reaction and Western blotting. KEY FINDINGS: CRP significantly and dose-dependently inhibited TRAP-positive multinucleated cell formation in RANKL-induced RAW 264.7 cell cultures. We observed suppression of p38, ERK and AKT mitogen-activated protein kinases induced by RANKL in Western blots after CRP treatment of RAW 264.7 cells. CRP also suppressed ALP activity and mineralization by Alizarin red S staining of MC3T3-E1 cell cultures. CRP suppressed osteoclast-specific and osteoblast-specific genes. Furthermore, CRP increased interferon beta (IFN-β) mRNA expression and protein levels in RAW 264.7 and MC3T3-E1 cells, and these effects were suppressed by oxPAPC, an inhibitor of Toll-like receptor (TLR) signaling. SIGNIFICANCE: These data indicated that CRP may have a direct role on osteoclast and osteoblast differentiation via TLR signaling pathways.
AIMS: Inflammatory processes are involved in bone remodeling. C-reactive protein (CRP) is an acute phase reactant that reflects different degrees of inflammation. Accumulating evidence suggests that CRP is an inflammatory marker and a direct cause of disease. Therefore, we examined the direct effects of CRP on bone cells. MAIN METHODS: We used RAW 264.7 cells to evaluate the direct effects of CRP on osteoclast differentiation. We carried out alkaline phosphatase (ALP) and bone nodule formation assays using MC3T3-E1 cells to evaluate osteoblast differentiation. Expression of osteoclast-specific and osteoblast-specific genes and effects on cell signaling pathways associated with cell differentiation were analyzed by reverse transcription polymerase chain reaction and Western blotting. KEY FINDINGS:CRP significantly and dose-dependently inhibited TRAP-positive multinucleated cell formation in RANKL-induced RAW 264.7 cell cultures. We observed suppression of p38, ERK and AKT mitogen-activated protein kinases induced by RANKL in Western blots after CRP treatment of RAW 264.7 cells. CRP also suppressed ALP activity and mineralization by Alizarin red S staining of MC3T3-E1 cell cultures. CRP suppressed osteoclast-specific and osteoblast-specific genes. Furthermore, CRP increased interferon beta (IFN-β) mRNA expression and protein levels in RAW 264.7 and MC3T3-E1 cells, and these effects were suppressed by oxPAPC, an inhibitor of Toll-like receptor (TLR) signaling. SIGNIFICANCE: These data indicated that CRP may have a direct role on osteoclast and osteoblast differentiation via TLR signaling pathways.
Authors: Mathias Haarhaus; Giuseppe Cianciolo; Simona Barbuto; Gaetano La Manna; Lorenzo Gasperoni; Giovanni Tripepi; Mario Plebani; Maria Fusaro; Per Magnusson Journal: Nutrients Date: 2022-05-19 Impact factor: 6.706
Authors: Moayad Mustafa Hejazi; Ala Osman Bacha; Mohammed Kaleemuddin; Fahad A Al-Abassi; Abdulbasit I Al-Alsieni; Imran Kazmi; Firoz Anwar Journal: Mol Cell Biochem Date: 2017-12-16 Impact factor: 3.396