Osteoarthritis is recognised to be an interactive pathological process involving the cartilage, subchondral bone and synovium. The signals from the synovium play an important role in cartilage metabolism, but little is known regarding the influence of the signalling from bone. Additionally, the collagenases and stromelysin-1 are involved in cartilage catabolism through mitogen-activated protein kinase (MAPK) signalling, but the role of the gelatinases has not been elucidated. Here, we studied the influence of osteoclastic signals on chondrocytes by characterising the expression of interleukin-1β (IL-1β)-induced gelatinases through MAPK signalling. We found that osteoclast-conditioned media attenuated the gelatinase activity in chondrocytes. However, IL-1β induced increased levels of gelatinase activity in the conditioned media group relative to the mono-cultured chondrocyte group. More specifically, IL-1β restored high levels of gelatinase activity in c-Jun N-terminal kinase inhibitor-pretreated chondrocytes in the conditioned media group and led to lower levels of gelatinase activity in extracellular signal-regulated kinase or p38 inhibitor-pretreated chondrocytes. Gene expression generally correlated with protein expression. Taken together, these results show for the first time that signals from osteoclasts can influence gelatinase activity in chondrocytes. Furthermore, these data show that IL-1β restores gelatinase activity through MAPK inhibitors; this information can help to increase the understanding of the gelatinase modulation in articular cartilage.
3T3 Cells ; Animals ; Cartilage, Articular ; cytology ; Cell Survival ; physiology ; Cells, Cultured ; Chondrocytes ; drug effects ; enzymology ; Coculture Techniques ; Culture Media, Conditioned ; Gelatinases ; drug effects ; Interleukin-1beta ; pharmacology ; JNK Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; MAP Kinase Signaling System ; physiology ; Matrix Metalloproteinase 2 ; drug effects ; Matrix Metalloproteinase 9 ; drug effects ; Mice ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; drug effects ; Monocytes ; cytology ; NF-kappa B ; antagonists & inhibitors ; Osteoclasts ; physiology ; Protease Inhibitors ; analysis ; Tissue Inhibitor of Metalloproteinase-1 ; drug effects ; Tissue Inhibitor of Metalloproteinase-2 ; drug effects ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors

This study investigated effects of Ginsenoside Ro (Ro) on interleukin-1β (IL-1β)-induced apoptosis and inflammation in rat chondrocytes. The rat chondrocytes were co-treated with IL-1β (10 ng·kg(-1)) and Ro (50, 100 and 200 μmol·L(-1)) for 48 h. Chondrocytes viability was detected by the MTT assay and Annexin V-FITC/PI dual staining assay. Caspase 3 activity was measured by using caspase 3 colorimetric assay kit. Apoptosis related proteins Bax, Bad, Bcl-xL, PCNA, p53 and phospho-p53, along with inflammation related protein MMP 3, MMP 9 and COX-2, and the expression of phospho-NF-κB p65 were assayed by western blotting analyses. Ro could improve IL-1β-induced chondrocytes viability. Ro could suppress IL-1β-induced apoptosis by inhibiting levels of Bax and Bad, decreasing p53 phosphorylation and promoting the expression of Bcl-xL and PCNA. Ro inhibited caspase 3 activity. IL-1β-induced inflammation and matrix degration were also alleviated by Ro with down-regulating the expression of MMP 3, MMP 9 and COX-2. Moreover, Ro inhibited NF-κB p65 phosphorylation induced by IL-1β. In conclusion, these results suggested Ro exerted anti-apoptosis and anti-inflammation in IL-1β-induced rat chondrocytes, which might be related to NF-κB signal pathway. Therefore, we propose that Ro might be a potential novel drug for the treatment of osteoarthritis.
Animals ; Anti-Inflammatory Agents ; pharmacology ; Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; drug effects ; metabolism ; Caspase 3 ; metabolism ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; Cyclooxygenase 2 ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Drug Evaluation, Preclinical ; Ginsenosides ; pharmacology ; Inflammation ; chemically induced ; drug therapy ; Interleukin-1beta ; antagonists & inhibitors ; pharmacology ; Matrix Metalloproteinase 3 ; drug effects ; metabolism ; Matrix Metalloproteinase 9 ; drug effects ; NF-kappa B ; antagonists & inhibitors ; drug effects ; metabolism ; Phosphorylation ; drug effects ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

Sphingosine kinase 1 (SphK1) plays critical roles in cell biological functions. Here we investigated the effects of SphK1 inhibitor SKI II on hepatoma HepG2 cell cycle progression and invasion. Cell survival was determined by SRB assay, cell cycle progression was assayed by flow cytometry, the ability of cell invasion was measured by Matrigel-Transwell assay and protein expression was detected by Western blotting. The results showed that SKI II markedly inhibited HepG2 cell survival in a dose-dependent manner, induced G1 phase arrest in HepG2 cell and inhibited cell invasion. SKI II markedly decreased the expressions of G1-phase-related proteins CDK2, CDK4 and Cdc2 and the levels of cell invasion-associated proteins MMP2 and MMP9. The results showed that SKI II inhibited cell cycle progression and cell invasion, implying SphK1 as a potential target for hepatoma treatment.
CDC2 Protein Kinase ; Cell Movement ; drug effects ; Cell Survival ; drug effects ; Cyclin-Dependent Kinase 2 ; metabolism ; Cyclin-Dependent Kinase 4 ; metabolism ; Cyclin-Dependent Kinases ; metabolism ; G1 Phase ; drug effects ; Hep G2 Cells ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Phosphotransferases (Alcohol Group Acceptor) ; antagonists & inhibitors ; Thiazoles ; pharmacology

OBJECTIVETo investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-κB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9).

METHODSAnnexin V-FITC/propidium iodide (PI) labeling and western blotting were used to observe and determine the apoptosis in TNFα-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants.

RESULTSIt was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFα for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated (from proMMP-9 to active MMP-9), and the physiologic calcium concentration (2.5 mmol/L) could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFα for 24 h. The stimulatory effect of TNFα just on proMMP-9 was counteracted significantly by CAPE.

CONCLUSIONNF-κB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFα (a pro-apoptotic factor). Therefore, therapeutic NF-κB inhibitor was a 'double-edged swords' to the apoptosis of chondrocytes and the secretion of MMP-9.

Aged ; Apoptosis ; drug effects ; Caffeic Acids ; pharmacology ; therapeutic use ; Calcium ; physiology ; Cells, Cultured ; Chondrocytes ; drug effects ; enzymology ; secretion ; Drug Evaluation, Preclinical ; Female ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; NF-kappa B ; antagonists & inhibitors ; Osteoarthritis ; drug therapy ; enzymology ; Phenylethyl Alcohol ; analogs & derivatives ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; pharmacology

Curcumin, as a main pharmacological component in the traditional Chinese medicine-turmeric, has shown anti-inflammatory, anti-oxidation, anti-tumor and anti-fibrotic effects. This study aimed to investigate the possible underlying signaling pathway which was involved in the inhibition of LDL-induced proliferation of mesangial cells and matrix by curcumin. Rat mesangial cells in vitro were incubated with low-density lipoprotein (LDL) and different concentrations of curcumin (0, 6.25, 12.5, 25.0 μmol/L) or p38 MAPK inhibitor, SB203580 (10 μmol/L). Under LDL incubation, mesangial cells proliferated, the expression of MMP-2 mRNA and protein was decreased, the expression of COX-2 mRNA and protein was increased, reactive oxygen species (ROS) generation was increased and p38 MAPK was activated significantly (P<0.05). When LDL-induced cells were treated with curcumin in the concentration of 12.5 or 25.0 μmol/L, LDL-induced proliferation of mesangial cells was suppressed, the expression of MMP-2 mRNA and protein increased, the expression of COX-2 mRNA and protein downregulated, the production of ROS inhibited and p38 MAPK inactivated (P<0.05). In conclusion, curcumin can inhibit the LDL-induced proliferation of mesangial cells and up-regulate the expression of MMP-2, which may be related with the inhibitory effect of curcumin on COX-2 expression, ROS production and p38 MAPK.
Animals ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; Blotting, Western ; Cell Proliferation ; drug effects ; Cells, Cultured ; Curcumin ; pharmacology ; Cyclooxygenase 2 ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Down-Regulation ; Enzyme Inhibitors ; pharmacology ; Extracellular Matrix ; drug effects ; metabolism ; Gene Expression ; drug effects ; Imidazoles ; pharmacology ; Lipoproteins, LDL ; pharmacology ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Mesangial Cells ; drug effects ; metabolism ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism

Cholesterol is one of major components of cell membrane and plays a role in vesicular trafficking and cellular signaling. We investigated the effects of cholesterol on matrix metalloproteinase-2 (MMP-2) activation in human dermal fibroblasts. We found that tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression and active form MMP-2 (64 kD) were dose-dependently increased by methyl-beta-cyclodextrin (MbetaCD), a cholesterol depletion agent. In contrast, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation were suppressed by cholesterol repletion. Then we investigated the regulatory mechanism of TIMP-2 expression by cholesterol depletion. We found that the phosphorylation of JNK as well as ERK was significantly increased by cholesterol depletion. Moreover, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation was significantly decreased by MEK inhibitor U0126, and JNK inhibitor SP600125, respectively. While a low dose of recombinant TIMP-2 (100 ng/ml) increased the level of active MMP-2 (64 kD), the high dose of TIMP-2 (> or = 200 ng/ml) decreased the level of active MMP-2 (64 kD). Taken together, we suggest that the induction of TIMP-2 by cholesterol depletion leads to the conversion of proMMP-2 (72 kD) into active MMP-2 (64 kD) in human dermal fibroblasts.
Anthracenes/pharmacology ; Butadienes/pharmacology ; Cells, Cultured ; Child ; Child, Preschool ; Cholesterol/metabolism/*physiology ; Cyclodextrins/pharmacology ; Enzyme Inhibitors/pharmacology ; Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors/physiology ; Fibroblasts/*drug effects/*metabolism/ultrastructure ; Humans ; Immunoblotting ; Immunoprecipitation ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/physiology ; Matrix Metalloproteinase 2/*metabolism ; Microscopy, Electron, Transmission ; Nitriles/pharmacology ; Tissue Inhibitor of Metalloproteinase-2/*metabolism

One of the 14-3-3 protein isoforms, 14-3-3epsilon, was previously shown to be increased during skin aging. We suggest here a possible role for the 14-3-3epsilon protein in skin aging by providing evidence that 14-3-3epsilon increases the expression of the matrix-metalloproteinase (MMP)-2 gene in NIH3T3 fibroblast cells. Expression of the 14-3-3epsilon gene in NIH3T3 cells primarily up-regulated the expression of the MMP-2 gene at the transcriptional level by inducing specific DNA binding proteins bound to an upstream region of the MMP-2 promoter from -1,629 to -1,612. Inhibition of endogenous 14-3-3epsilon gene expression by RNA interference also decreased endogenous MMP-2 gene expression. Furthermore, up-regulation of the MMP-2 gene by 14-3-3epsilon was suppressed by expression of a dominant-negative mutant of p38 MAP kinase. These findings strongly suggest that increased expression of 14-3-3epsilon contributes to remodeling of extracellular matrix in skin through increasing MMP-2 gene expression via p38 MAP kinase signaling.
14-3-3 Proteins/*physiology ; Animals ; Electrophoretic Mobility Shift Assay ; Gene Expression Regulation, Enzymologic/*physiology ; Matrix Metalloproteinase 2/antagonists & inhibitors/*genetics/metabolism ; Mice ; NIH 3T3 Cells ; Plasmids ; Promoter Regions, Genetic ; RNA, Messenger/genetics/metabolism ; RNA, Small Interfering/pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; *Signal Transduction ; Transfection ; p38 Mitogen-Activated Protein Kinases/*metabolism

OBJECTIVETo investigate P2Y purinergic receptor activated PI-3K/Akt signaling pathway in the regulation of growth and invasion of prostate cancer in vitro.

METHODSWestern blot was used to detect phosphorylation of Akt (a downstream target molecule of PI-3K) by P2Y receptor agonist in 1E8 cells (a highly metastatic subclone derived from PC-3 prostatic cancer cell line). Cell counts, flow cytometry, Matrigel invasion assay, wound healing assay and gelatin zymography were used to detect changes of biological behaviors of 1E8 cells after P2Y receptor activation.

RESULTSAMP-PNP, one non-hydrolysis ATP analogue and P2Y receptor agonist, induced significant phosphorylation of Akt in a time- and dose-dependent manner in IE8 cells. LY294002, a specific inhibitor of PI-3K, effectively blocked Akt phosphorylation induced by AMP-PNP. Continuous exposure to AMP-PNP induced significant growth inhibition of 1E8 cells (inhibition rate at 50.2% at the 8th day), and this inhibition was mainly due to an arrest at S phase of the cell cycle (the S phase fraction of AMP-PNP treated cells was 22.3% higher than that of the control). Application of LY294002 did not reverse the growth inhibition effect of AMP-PNP. Matrigel invasion assay showed that AMP-PNP stimulation increased invasive ability of 1E8 cells, and this effect was effectively blocked by LY294002. No significant changes in the activation of MMP-2 and MMP-9 were detected by gelatin zymography, although wound healing assay showed 21.2% increase in cell migration after AMP-PNP treatment.

CONCLUSIONSPI-3K/Akt signaling pathway participates in P2Y receptor-stimulated prostate cancer invasion by enhancing cell motility, rather than up-regulating MMP-2 and MMP-9 activities. PI-3K signaling pathway plays an important role in prostate cancer proliferation, but is not involved in P2Y receptor mediated growth inhibition.

Adenylyl Imidodiphosphate ; pharmacology ; Animals ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Chromones ; pharmacology ; Humans ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Mice ; Mice, Nude ; Morpholines ; pharmacology ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; metabolism ; Phosphorylation ; Prostatic Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins c-akt ; metabolism ; Purinergic P2 Receptor Agonists ; S Phase ; drug effects ; Signal Transduction ; drug effects

OBJECTIVETo investigate the effect and mechanism of blockade of STAT3 signaling pathway by JAK specific inhibitor-AG490 on invasion and metastasis of human highly metastatic pancreatic cancer line SW1990 in vitro.

METHODSAG490 was added into the culture media for SW1990 cells. The invasion ability of SW1990 cells was determined by cell invasion assay kit. Western blot was performed to detect the protein expression of the STAT3, phosphorylated STAT3 (p-STAT3), MMP-2 and VEGF. RT-PCR was performed to detect the mRNA expression of the MMP-2 and VEGF.

RESULTS20 micromol/L AG490 significantly inhibited the invasion ability of SW1990 cells and the inhibitory rate of invasion ability was (77.67 +/- 7.79) %. The use of AG490 not only markedly reduced the protein expression of p-STAT3, MMP-2 and VEGF, but also greatly reduced the mRNA expression of MMP-2 and VEGF.

CONCLUSIONBlocking STAT3 activation with AG490 can inhibit the invasion and metastasis ability of pancreatic cancer cells in vitro through down-regulation of MMP-2 and VEGF expression. Blocking STAT3 signaling pathway may provide a novel strategy in prevention of invasion and metastasis of pancreatic cancer.

Antineoplastic Agents ; pharmacology ; Blotting, Western ; Cell Line, Tumor ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Janus Kinases ; antagonists & inhibitors ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Pancreatic Neoplasms ; genetics ; metabolism ; pathology ; Phosphorylation ; drug effects ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; drug effects ; Tyrphostins ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVETo investigate the role of TGF-beta(1)/MAPK signaling pathways in the expression of type I collagen and activity of MMP-2, 9 in human lung fibroblasts.

METHODSHuman lung fibroblasts cell line (HLF-02) was cultured and and then stimulated with 10 ng/ml TGF-beta(1) for different time; SB203580 or PD98059 was added into culture medium to block p38 or ERK kinase pathway before incubated with TGF-beta(1); the expression of type I collagen was detected by Western blotting and RT-PCR; zymogram analysis was used to analyze the activity of MMP-2 and MMP-9.

RESULTS(1) In the process of stimulation by TGF-beta(1), the type I collagen mRNA level of 24 h, 48 h and 72 h group was: 1.33 +/- 0.07, 2.46 +/- 0.09 and 2.39 +/- 0.08 respectively; and the type I collagen protein level of 24 h, 48 h and 72 h group was: 114.89 +/- 8.95, 208.16 +/- 6.75 and 211.46 +/- 8.05 respectively; and the activity of MMP-2 of 24 h, 48 h and 72 h group was: 190.33 +/- 5.86, 214.33 +/- 8.39 and 212.67 +/- 11.59 respectively. (2) SB203580 significantly inhibited the TGF-beta(1)-induced expression of type I collagen mRNA, protein and MMP-2 activity (inhibition ratio: 51%, 24% and 20%); (3) PD98059 also significantly attenuated the TGF-beta(1)-induced expression of type I collagen mRNA, protein and MMP-2 activity (inhibition ratio: 42%, 13% and 16%).

CONCLUSIONTGF-beta(1) is capable of inducing the expression of type I collagen mRNA and protein and up-regulating MMP-2 activity in HLF-02 cells. p38 and ERK kinase signaling pathways play important role in regulation and control for this process.

Blotting, Western ; Cell Line ; Collagen Type I ; biosynthesis ; genetics ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; physiology ; Fibroblasts ; drug effects ; metabolism ; Flavonoids ; pharmacology ; Humans ; Imidazoles ; pharmacology ; Lung ; cytology ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Pyridines ; pharmacology ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; physiology ; Transforming Growth Factor beta1 ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; physiology