In order to obtain the nuclear extracts of NF-B, the nuclear proteins were prepared using a nuclear protein extraction kit (Beyotime Institute of Institute of Biotechnology, Haimen, China, p0027) according to the manufacturer’s protocol

In order to obtain the nuclear extracts of NF-B, the nuclear proteins were prepared using a nuclear protein extraction kit (Beyotime Institute of Institute of Biotechnology, Haimen, China, p0027) according to the manufacturer’s protocol. in TNF–treated RAW264.7 cells may be, at least in part, through suppression of NF-B activation and the MAPK pathway. These findings support the notion that aspirin has therapeutic potential application in the prevention and treatment of atherosclerosis disease. also proved that increased expression of MMP-9 induced by TNF- was reduced by the specific inhibitors of MAPK signaling pathway in human keratinocytes (22). Nuclear factor-B (NF-B) binds to the proximal promoter region of the MMP-9 gene and regulates MMP-9 transcription in response to distinct extracellular stimulation of TNF- (23,24), which is one of the strongest physiological inducers of MMP-9 expression (25). Aspirin, a conventional nonselective non-steroidal anti-inflammation drug, is widely used in the primary prevention against cardiac-cerebral vascular diseases, such as myocardial infarction and stroke, and 20C25% of patients with various vascular diseases who were treated with aspirin presented decreased development of vascular events (26). The anti-platelet function of aspirin is known to contribute to the therapy of atherosclerotic cardiovascular disease. However, the anti-inflammatory effect of aspirin in atherosclerosis is not widely reported. Previous studies (3C5) have demonstrated that atherosclerosis is a complex vascular inflammation disease. A clinical study has shown that patients receiving treatment with aspirin exhibited lower macrophage density of the carotid atherosclerotic plaque, suggesting that aspirin is involved in the suppression of the vascular inflammation process (27). Hua (28) also reported that aspirin prevented against atherosclerotic plaque rupture by inhibiting MMP-9 expression by upregulating peroxisome proliferator-activated receptor / (PPAR/) expression in oxidized low-density lipoprotein-stimulated macrophages and by inducing TIMP metallopeptidase inhibitor 1 (TIMP1) and TIMP2 expression. However, whether aspirin inhibits the expression of MMP-9 via the MAPK and NF-B signaling pathways in TNF–stimulated RAW264.7 cells remains unknown. Therefore, the present study investigated the effects and mechanisms of aspirin on MMP-9 expression in TNF–stimulated RAW264.7 cells. Materials and methods Materials Antibodies against JNK (1:500 dilution, BS6448), p38 (1:500 dilution, BS3566), ERK (1:1,000 dilution, AP0485), phospho-JNK (1:500 dilution, BS4763), phospho-p38 (1:500 dilution, BS4635) and phospho-ERK (1:1,000 dilution, BS4759) were purchased from Bioworld Technology (Beijing, China). SB203580 (p38MAPK inhibitor, 5633S), SP600125 (JNK inhibitor, 8177S) and PD98059 (ERK1/2 inhibitor, 9900S) and PDTC (NF-B inhibitor) were purchased from Cell Signaling Technology, Inc. (Danvers, MA, USA). An antibody against the p65 subunit of NF-B was also purchased from Cell Signaling Technology, Inc. (1:500 dilution, 8242). An antibody against MMP-9 was purchased from EMD Millipore (Chemicon; Billerica, MA, USA, 1:500 dilution, AB19016). Recombinant murine TNF- was purchased from Thermo Fisher Scientific, Inc. (Biosource; MA, USA), and aspirin was purchased from Langtze Biomedical Technology (Nanjing, China). Cell cultures Murine macrophage RAW264.7 cells, purchased from the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China), were cultured in plastic dishes containing Dulbecco’s modified Eagle’s medium (DMEM; Sigma-Aldrich, St. Louis, MO, USA) supplemented with 10% fetal bovine serum (Sigma-Aldrich), 100 U/ml penicillin and 100 g/ml streptomycin at 37C and 5% CO2. For all experiments, cells were grown to 60C80% confluence in culture flasks. Then, the SirReal2 medium was replaced with fresh DMEM and cells were transferred into multiple flasks for further expansion. The control groups were treated with medium only. In order to study the expression of MMP-9, TNF- (10 ng/ml) was added in the presence or absence of aspirin (75, 150, 300 and 600 M) for 24 h. For the inhibitory study, PDTC, an inhibitor of NF-B, can significantly inhibit NF-B activity, and further reduce the production of inflammatory cytokines, alleviating the systemic inflammatory response (29). In order to determine the effect of PDTC on TNF–induced expression of MMP-9 in RAW264.7 cells, the cells were divided into six groups and incubated with either TNF- or TNF- plus PDTC, PDTC and aspirin, aspirin or PDTC only group,.The gels were subsequently incubated in zymogen development buffer [50 mM Tris-HCl (pH 7.5), 150 mM NaCl, 10 mM CaCl2, 0.02% NaN3, Nos1 SirReal2 and 1 M ZnCl2] at 37C for 24C48 h. separately. It was also observed that aspirin has a suppressive effect on the activation of nuclear factor (NF)-B and inhibits the phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases 1/2, p38 and c-Jun N-terminal kinase. Furthermore, subsequent to inhibition of the MAPK pathway by specific inhibitors (PD98059, SB203580 and SP600125), the expression of MMP-9 was reduced, indicating that the inhibitory effect of aspirin on MMP-9 in TNF–treated RAW264.7 cells may be, at least in part, through suppression of NF-B activation and the MAPK pathway. These findings support the notion that aspirin has therapeutic potential application in the prevention and treatment of atherosclerosis disease. also proved that increased expression of MMP-9 induced by TNF- was reduced by the specific inhibitors of MAPK signaling SirReal2 pathway in human keratinocytes (22). Nuclear factor-B (NF-B) binds to the proximal promoter region of the MMP-9 gene and regulates MMP-9 transcription in response to distinct extracellular stimulation of TNF- (23,24), which is one of the strongest physiological inducers of MMP-9 expression (25). Aspirin, a conventional nonselective non-steroidal anti-inflammation drug, is widely used in the primary prevention against cardiac-cerebral vascular diseases, such as myocardial infarction and stroke, and 20C25% of patients with various vascular diseases who were treated with aspirin presented decreased development of vascular events (26). The anti-platelet function of aspirin is known to contribute to the therapy of atherosclerotic cardiovascular disease. However, the anti-inflammatory effect of aspirin in atherosclerosis is not widely reported. Previous studies (3C5) have demonstrated that atherosclerosis is a complex vascular inflammation disease. A clinical study has shown that patients receiving treatment with aspirin exhibited lower macrophage density of the carotid atherosclerotic plaque, suggesting that aspirin is involved in the suppression of the vascular inflammation process (27). Hua (28) also reported that aspirin prevented against atherosclerotic plaque rupture by inhibiting MMP-9 expression by upregulating peroxisome proliferator-activated receptor / (PPAR/) expression in oxidized low-density lipoprotein-stimulated macrophages and by inducing TIMP metallopeptidase inhibitor 1 (TIMP1) and TIMP2 expression. However, whether aspirin inhibits the expression of MMP-9 via the MAPK and NF-B signaling pathways in TNF–stimulated RAW264.7 cells remains unknown. Therefore, the present study investigated the effects and mechanisms of aspirin on MMP-9 expression in TNF–stimulated RAW264.7 cells. Materials and methods Materials Antibodies against JNK (1:500 dilution, BS6448), p38 (1:500 dilution, BS3566), ERK (1:1,000 dilution, AP0485), phospho-JNK (1:500 dilution, BS4763), phospho-p38 (1:500 dilution, BS4635) and phospho-ERK (1:1,000 dilution, BS4759) were purchased from Bioworld Technology (Beijing, China). SB203580 (p38MAPK inhibitor, 5633S), SP600125 (JNK inhibitor, 8177S) and PD98059 (ERK1/2 inhibitor, 9900S) and PDTC (NF-B inhibitor) were purchased from Cell Signaling Technology, Inc. (Danvers, MA, USA). An antibody against the p65 subunit of NF-B was also purchased from Cell Signaling Technology, Inc. (1:500 dilution, 8242). An antibody against MMP-9 was purchased from EMD Millipore (Chemicon; Billerica, MA, USA, 1:500 dilution, Abdominal19016). Recombinant murine TNF- was purchased from Thermo Fisher Scientific, Inc. (Biosource; MA, USA), and aspirin was purchased from Langtze Biomedical Technology (Nanjing, China). Cell ethnicities Murine macrophage Natural264.7 cells, purchased from the Type Culture Collection of the Chinese Academy of Sciences (Shanghai, China), were cultured in plastic dishes comprising Dulbecco’s modified Eagle’s medium (DMEM; Sigma-Aldrich, St. Louis, MO, USA) supplemented with 10% fetal bovine serum (Sigma-Aldrich), 100 U/ml penicillin and 100 g/ml streptomycin at 37C and 5% CO2. For those experiments, cells were cultivated to 60C80% confluence in tradition flasks. Then, the medium was replaced with new DMEM and cells were transferred into multiple flasks for further development. The control organizations were treated with medium only. In order to study the manifestation of MMP-9, TNF- (10 ng/ml) was added in the presence or absence of aspirin (75, 150, 300 and 600 M) for 24 h. For the inhibitory study, PDTC, an inhibitor of NF-B,.