Activation Of P38 MAPK Signaling Pathways Research Articles

Antiproliferative Effects of CC-8062 and CC-8075 in Pancreatic Cancer Cells

Pancreatic cancer is one of the leading causes of cancer related deaths in the western world. It is also resistant to most chemotherapeutic modalities. Phosphodiesterase-4 inhibitors (PDE4is) have found applications in the treatment of respiratory diseases. The aim of this study is to investigate the cytotoxic effect of 2 novel PDE4is, the CC-8075 and CC-8062 compounds in pancreatic cancer cells. Cell proliferation was measured using the sulforhodamine B protein dye. Induction of apoptosis was detected using enzyme-linked immunosorbent assay. Regulation of proteins and posttranslational modifications were determined using immunoblotting. Treatment of pancreatic cancer cells with CC-8075 and CC-8062 reduces their proliferation and increases apoptosis that is caspase dependent in T3M4 cells. Furthermore, PDE4is increase phosphorylation of p38MAPK, mitogen-activated protein kinase (MAPK) kinase 3/6,MAPKYactivated protein kinase 2, Atf2, and Hsp27. The use of thep38MAPK-specific inhibitors SB202190 and SB203580 results in a modest reduction in PDE4i-induced apoptosis in T3M4 cells. Also, retinoids enhance apoptosis induced by CC-8075 and CC-8062 in GER cells. These results highlight the antiproliferative effects of the phosphodiesterase inhibitors CC-8075 and CC-8062 in pancreatic cancer cells and suggest that activation of p38MAPK signaling pathway may be associated with this process.

Neointimal formation is reduced after arterial injury in human crp transgenic mice

Objectives/Methods Elevated CRP levels predict increased incidence of cardiovascular events and poor outcomes following interventions. There is the suggestion that CRP is also a mediator of vascular injury. Transgenic mice carrying the human CRP gene (CRPtg) are predisposed to arterial thrombosis post-injury. We examined whether CRP similarly modulates the proliferative and hyperplastic phases of vascular repair in CRPtg when thrombosis is controlled with daily aspirin and heparin at the time of trans-femoral arterial wire-injury. Results Complete thrombotic arterial occlusion at 28 days was comparable for wild-type and CRPtg mice (14 and 19%, respectively). Neointimal area at 28d was 2.5 fold lower in CRPtg (4190 ± 3134 μm 2, n = 12) compared to wild-types (10,157 ± 8890 μm 2, n = 11, p < 0.05). Likewise, neointimal/media area ratio was 1.10 ± 0.87 in wild-types and 0.45 ± 0.24 in CRPtg ( p < 0.05). Seven days post-injury, cellular proliferation and apoptotic cell number in the intima were both less pronounced in CRPtg than wild-type. No differences were seen in leukocyte infiltration or endothelial coverage. CRPtg mice had significantly reduced p38 MAPK signaling pathway activation following injury. Conclusions The pro-thrombotic phenotype of CRPtg mice was suppressed by aspirin/heparin, revealing CRP's influence on neointimal growth after trans-femoral arterial wire-injury. Signaling pathway activation, cellular proliferation, and neointimal formation were all reduced in CRPtg following vascular injury. Increasingly we are aware of CRP multipotent effects. Once considered only a risk factor, and recently a harmful agent, CRP is a far more complex regulator of vascular biology.

Effects of aldose reductase on the transforming growth factor-beta1-induced expression of fibronectin and collagen IV: experiment with cultured rat mesangial cells

To study the effects of aldose reductase (AR) on the transforming growth factor (TGF)-beta1-induced expression of fibronectin (FN) and collagen IV. Restriction endonucleases digestion and ligation were used to reconstruct the eukaryotic expression plasmid pCDNA3-AR. Rat mesangial cells (MsCs) were isolated, cultured, and transfected with pCDNA3-AR, or blank vector. The AR expression in the MsCs was examined by immunofluorescence analysis. RT-PCR was performed to detect the mRNA expression of AR in the MsCs and Western blotting was used to detect the protein expression of AR. AR inhibitors (ARIs), Sorbinil and Zopolrestat were added and co-incubated, then TGF)-beta1 was added and Western blotting was used to analyze the protein expression of FN, collagen IV (Col IV), and mitogen-activated protein kinases (MAPKs) in the MsCs. Immunofluorescence analysis showed stronger expression of AR in the MsCs transfected with AR then in the normal MsCs and the MsCs transfected with blank vector. In comparison with the normal MsCs and those transfected with blank vector, the MsCs transfected with AR showed stronger protein expression of FN and Col IV (all P < 0.05). After incubation of ARIs the protein expression of FN and Col IV decreased by 1.8 and 2.0 times respectively in the MsCs transfected with AR (all P < 0.05). After stimulation of TGF-beta1, the protein expression of FN and Col IV increased in both the normal MsCs and those transfected with AR (P < 0.05 for the latter). After preincubation with ARIs the protein expression of FN and Col IV in the MsCs transfected decreased significantly (both P < 0.05). After stimulation of TGF-beta1, the normal MsCs showed increased expression of phospho-ERK, phospho-JNK, and phospho-p38; the MsCs preincubated with ARIs showed reduced expression of phospho-JNK and phospho-p38; and the MsCs transfected with AR showed increased expression of phosphor-JNK (P < 0.05). AR can regulates the expression of FN and Col IV with the stimulation of TGF-beta1 as AR gene is one of the responsive genes of TGF-beta1, which may have relations with the activation of JNK-MAPK and p38-MAPK signaling pathways induced by TGF-beta1. AR may play a role in the pathogenesis of glomerulosclerosis.

Oxidative stress induced HSP27 expression in human lens epithelial cells is regulated by P38 map kinase

To investigate the role of P38MAPK signaling pathway in hydrogen peroxide (H2O2) induced the expression of heat shock protein 27 in human lens epithelial cell line HLE-B3. Human lens epithelial cell line HLE-B3 was cultured and then co-incubated with H2O2 (100 micromol/L, 200 micromol/L) for different time with or without pretreatment with Specific P38MAPK inhibitor SB 203580. RT-PCR and Western blotting were used to detect HSP(27) mRNA and protein expressions at different time points after H2O2 stimulation in human lens epithelial cells. Western blotting was used to detect the expression of phosphorylated P38MAPK. The expression of HSP(27) mRNA and protein was increased significantly after the H2O2 stimulation. The activity of stress-activated protein kinase was increased at 30 minutes after treatment with H2O2 and decreased to base level at 6 hours (P < 0.01). The expression of phosphorylation of P38MAPK was increased after treatment of H2O2 and reached the highest level at 15 minutes after stimulation and then decreased. The expression of HSP(27) was down-regulated with the pretreatment of SB 203580 compared with that in the H2O2 group (P < 0.01). H2O2 induces the expression of heat shock protein 27 in human lens epithelial cell line. The effects are mediated, at least in part, through the activation of P38MAPK signaling pathway.