Tanshinone IIA prevents platelet activation and down-regulates CD36 and MKK4/JNK2 signaling pathway.

BACKGROUND: Tanshinone IIA (TS IIA), a multi-pharmaceutical compound from traditional Chinese herb, is effective for treatment of atherothrombosis. However, the underlying mechanisms of TS IIA-mediated anti-platelet activation effect are still poorly understood. As shown in our previous study, platelet-derived microvesicles (PMVs) generated in response to oxidant insult could activate CD36/mitogen-activated protein kinase kinase 4/Jun N-terminal kinase 2 (CD36/MKK4/JNK2) signals and lead to platelet activation. The present study aims to investigate the effect of TS IIA on platelet activation and the possible mechanisms. METHODS: The production of PMVs induced by Interleukin 6 (IL-6) was detected by flow cytometry. We performed activating studies of platelets with PMVs derived from IL-6-treated platelets (IL-6-PMVs) in vitro. Sometimes, platelet suspensions were incubated with serial concentrations of TS IIA for 15 min before being stimulated with IL-6-PMVs. Expression of platelet integrin αIIbß3 and CD36 was detected by flow cytometry. Phosphorylation of MKK4 and JNK were detected by immunoblotting. RESULTS: Here we demonstrated firstly that TS IIA could prevent platelet activation induced by PMVs and down-regulates CD36 and MKK4/JNK2 signaling pathway. CD36 may be the target of atherosclerosis (AS)-related thrombosis. CONCLUSIONS: This study showed the possible mechanisms of TS IIA-mediated anti-platelet activation and may provide a new strategy for the treatment of AS-related thrombosis by targeting platelet CD36.

CD4+ T cells and TGFß1/MAPK signal pathway involved in the valvular hyperblastosis and fibrosis in patients with rheumatic heart disease.

The aim of this study was to investigate the roles of CD4+ T cells and transforming growth factor beta (TGFß1) in the pathological process of valvular hyperblastosis and fibrosis of patients with rheumatic heart disease (RHD). A total of 151 patients were enrolled, among whom, 78 patients were with RHD, and 73 were age and gender matched RHD negative patients. Blood samples and valve specimens were collected for analysis. Pathological changes and collagen fibers contents of valves were analyzed using HE and Masson staining. Percentage of peripheral blood CD4+ T cells was tested through flow cytometry. TGFß1 level in serum were identified by ELISA. CD4+ T cells infiltration and expression of TGFß1, p-p38, p-JNK, p-ERK in valves were detected by immunohistochemistry. The mRNA and protein levels of p38, JNK, ERK, TGFß1, I-collagen and α-SMA were detected by qRT-PCR and western blotting, respectively. The heart valve tissues of RHD patients showed higher degrees of fibrosis, calcification and lymphocytes infiltration, which were mainly CD4+ T cells. In addition, compared with control group, RHD patients had more total CD4+ T cells in peripheral blood and valve tissues. Expression of TGFß1, phosphorylation of JNK and p38, and synthesis of I-collagen in valve tissues of RHD patients were also significantly increased. Furthermore, we found a strong positive correlation between TGFß1 expression and phosphorylation of JNK and p38. CD4+ T cells, and fibrogenic cytokine TGFß1, which activate the intracellular MAPK signaling pathway may participate in the fibrosis of heart valve in RHD patients.

Curcumin Attenuates Inflammation in a Severe Acute Pancreatitis Animal Model by Regulating TRAF1/ASK1 Signaling.

BACKGROUND Inflammation plays an important role in initiation and development of severe acute pancreatitis (SAP). Curcumin exerts potent anti-inflammatory effects in many diseases, including acute pancreatitis. However, the specific molecular mechanisms are not clear. MATERIAL AND METHODS Intra-biliopancreatic duct injection of taurocholate was used to establish an animal model of SAP. Curcumin was administrated to animals as pre-treatments. Concentrations of cytokines in serum and ascites were measured by enzyme-linked immunosorbent assay (ELISA). A colorimetric method was used to determine the amylase activity. Western blotting was used to examine the expression levels and phosphorylation levels of proteins. Immunoprecipitation was used to assess the molecular association between apoptosis signal- regulating kinase 1 (ASK1) and thioredoxin (Trx). RESULTS Pre-treatment with curcumin reduced the concentrations of interleukin (IL6) and tumor necrosis factor (TNFα) in serum and ascites, as well as the ascites volume and amylase activity in SAP rats. Pre-treatment with curcumin reduced the expression level of TNF receptor-associated factor 1 (TRAF1), IL6, and TNFa in pancreas in SAP rats. Moreover, the phosphorylation levels of mitogen-activated protein kinase (MAPK) kinase 4 (MKK4), MKK7, and c-Jun NH(2)-terminal protein kinase (JNK) were reduced by curcumin pre-treatment. The molecular association between ASK1 and Trx was recovered by curcumin pre-treatment. As a result, the nuclear translocation of nuclear factor kappa B (NF-κB) was suppressed in pancreases from SAP rats. CONCLUSIONS Activation of the TRAF1/ASK1/JNK/NF-κB signaling pathway is involved in the inflammation of SAP. Curcumin exerts anti-inflammatory effects by suppressing this proinflammatory pathway.

Plasma protein biomarkers of Alzheimer's disease endophenotypes in asymptomatic older twins: early cognitive decline and regional brain volumes.

There is great interest in blood-based markers of Alzheimer's disease (AD), especially in its pre-symptomatic stages. Therefore, we aimed to identify plasma proteins whose levels associate with potential markers of pre-symptomatic AD. We also aimed to characterise confounding by genetics and the effect of genetics on blood proteins in general. Panel-based proteomics was performed using SOMAscan on plasma samples from TwinsUK subjects who are asymptomatic for AD, measuring the level of 1129 proteins. Protein levels were compared with 10-year change in CANTAB-paired associates learning (PAL; n = 195), and regional brain volumes (n = 34). Replication of proteins associated with regional brain volumes was performed in 254 individuals from the AddNeuroMed cohort. Across all the proteins measured, genetic factors were found to explain ~26% of the variability in blood protein levels on average. The plasma level of the mitogen-activated protein kinase (MAPK) MAPKAPK5 protein was found to positively associate with the 10-year change in CANTAB-PAL in both the individual and twin difference context. The plasma level of protein MAP2K4 was found to suggestively associate negatively (Q < 0.1) with the volume of the left entorhinal cortex. Future studies will be needed to assess the specificity of MAPKAPK5 and MAP2K4 to eventual conversion to AD.

Carbonylated plasma proteins as potential biomarkers of obesity induced type 2 diabetes mellitus.

Protein carbonylation is a common nonenzymatic oxidative post-translational modification, which is often considered as biomarker of oxidative stress. Recent evidence links protein carbonylation also to obesity and type 2 diabetes mellitus (T2DM), though the protein targets of carbonylation in human plasma have not been identified. In this study, we profiled carbonylated proteins in plasma samples obtained from lean individuals and obese patients with or without T2DM. The plasma samples were digested with trypsin, carbonyl groups were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine, enriched by avidin affinity chromatography, and analyzed by RPC-MS/MS. Signals of potentially modified peptides were targeted in a second LC-MS/MS analysis to retrieve the peptide sequence and the modified residues. A total of 158 unique carbonylated proteins were identified, of which 52 were detected in plasma samples of all three groups. Interestingly, 36 carbonylated proteins were detected only in obese patients with T2DM, whereas 18 were detected in both nondiabetic groups. The carbonylated proteins originated mostly from liver, plasma, platelet, and endothelium. Functionally, they were mainly involved in cell adhesion, signaling, angiogenesis, and cytoskeletal remodeling. Among the identified carbonylated proteins were several candidates, such as VEGFR-2, MMP-1, argin, MKK4, and compliment C5, already connected before to diabetes, obesity and metabolic diseases.

Role of the functional MKK4 promoter variant (-1304T>G) in a decreased risk of prostate cancer: case-control study and meta-analysis.

PURPOSE: MKK4 has been suggested as a tumor suppressor. The functional variant (-1304T>G) in the MKK4 promoter has been implicated as a risk factor for many types of cancer. However, its role in prostate cancer (PCa) is unclear. To determine whether this SNP constitutes a risk factor for PCa susceptibility and to derive a more precise estimation of the associations between this SNP and cancer risk, we performed a case-control study and then a meta-analysis covering previous case-control studies. METHODS: In this study, 222 male patients with PCa and 244 cancer-free controls were evaluated MKK4-1304T>G genotype. The transcriptional activity of MKK4 gene was measured by luciferase assay, and MKK4 serum expression was measured by ELISA. RESULTS: As a whole, we found that compared to the most common -1304TT genotype, carriers of -1304G variant genotypes had a decreased risk of PCa (OR = 0.670; 95 % CI = 0.452-0.993, P = 0.046 for TG, and OR = 0.647; 95 % CI = 0.441-0.948, P = 0.025 for TG + GG). We found that carriers of the -1304G variant genotypes had greater transcriptional activity and serum expression of MKK4 than carriers of the -1304T allele. Our meta-analysis also suggested that the -1304G variant contributes to decreased risk of various cancers. CONCLUSION: Our results suggest that the functional -1304G variant in the MKK4 promoter decreases the risk of PCa by increasing the promoter activity. In the future, prospective researches on patients from many parts of the world may validate our findings.

Increased ERK and JNK activities correlate with disease activity in patients with systemic lupus erythematosus.

BACKGROUND: Aberrant signalling along the p21ras/MAP kinase pathway has been demonstrated in systemic lupus erythematosus (SLE). OBJECTIVE: To determine whether expression and activity of the MAP kinases ERK and JNK reflect disease activity in patients with SLE. METHODS: Blood samples of 42 outpatients with SLE were prospectively collected during four consecutive visits. The control group included 20 healthy subjects. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Expression of total ERK and JNK kinases and their active forms (pERK and pJNK) was determined in whole protein lysates of peripheral blood mononuclear cells. RESULTS: The mean levels of the active kinases pERK and pJNK were significantly increased in patients with active disease (SLEDAI 4-20) as compared with patients with inactive disease (SLEDAI 0-3), p = 0.04, as well as with healthy controls, p = 0.03 and p = 0.003 for pERK and pJNK, respectively. The percentage of activated forms of ERK and JNK of the total expression of these MAP kinases was also gradually increased, reaching 50% for pERK and >40% for pJNK in patients with SLE with moderate-to-severe disease (SLEDAI 7-20), p = 0.005, p = 0.005 and p = 0.02, p = 0.05 as compared with controls and inactive patients, respectively. A decrease of more than three SLEDAI points was associated with a significant reduction in the expression of both total and activated forms of ERK and JNK, p = 0.03, p = 0.01, respectively. CONCLUSIONS: The results show that ERK and JNK activity reflects disease activity in patients with SLE. These MAP kinases may serve as additional tools for the evaluation of disease activity and management of these patients.