CD8+ T cells contribute to macrophage accumulation and airspace enlargement following repeated irritant exposure

BACKGROUND: Persistent macrophage accumulation and alveolar enlargement are hallmark features of chronic obstructive pulmonary disease (COPD). A role for CD8(+) lymphocytes in the development of COPD is suggested based on observations that this T cell subset is increased in the airways and parenchyma of smokers that develop COPD with airflow limitation. In this study, we utilize a mouse model of COPD to examine the contributions of CD8(+) T cells in the persistent macrophage accumulation and airspace enlargement resulting from chronic irritant exposure. METHODS: We analyzed pulmonary inflammation and alveolar destruction in wild-type and Cd8-deficient mice chronically exposed to acrolein, a potent respiratory tract irritant. We further examined cytokine mRNA expression levels by RNase protection assay, matrix metalloproteinase (MMP) activity by gelatin zymography, and epithelial cell apoptosis by active caspase3 immunohistochemistry in wild-type and Cd8-deficient mice exposed chronically to acrolein. RESULTS: These studies demonstrate that CD8(+) T cells are important mediators of macrophage accumulation in the lung and the progressive airspace enlargement in response to chronic acrolein exposures. The expression of several inflammatory cytokines (IP-10, IFN-gamma, IL-12, RANTES, and MCP-1), MMP2 and MMP9 gelatinase activity, and caspase3 immunoreactivity in pulmonary epithelial cells were attenuated in the Cd8-deficient mice compared to wild-type. CONCLUSIONS: These results indicate that CD8(+) T cells actively contribute to macrophage accumulation and the development of irritant-induced airspace enlargement.     

Intracerebroventricular administration of an endothelin ETB receptor agonist increases expression of tissue inhibitor of matrix metalloproteinase-1 and -3 in rat brain

Production of tissue inhibitors of matrix metalloproteinases (TIMPs), a family of secreted proteins with inhibitory actions on matrix metalloproteinases (MMPs), is up-regulated following nerve injuries and is suggested to have protective effects against MMP-mediated tissue damages. To clarify the extracellular signals involved in TIMP production in the brain, the effects of endothelins (ETs), a family of vasoconstricting peptides, were examined. I.c.v. administration of 500 pmol/day Ala(1,3,11,15)-ET-1, an ET(B) receptor agonist, increased the level of TIMP-1 mRNA in rat hippocampus, caudate-putamen and cerebrum. Ala(1,3,11,15)-ET-1 increased the level of TIMP-3 mRNA in the cerebrum, but not in the hippocampus or caudate-putamen. TIMP-2 mRNA was not affected in these brain regions. Ala(1,3,11,15)-ET-1 also stimulated the production of TIMP-1 and TIMP-3 proteins in the cerebrum. Immunohistochemical observations in the hippocampi of Ala(1,3,11,15)-ET-1-infused rats showed that NeuN-positive neurons and glial fibrillary acidic protein-positive astrocytes were immunoreactive for TIMP-1. In the cerebrum, astrocytes had TIMP-1 and TIMP3 reactivity, but neurons did not. In rat cultured astrocytes, both 100 nM Ala(1,3,11,15)-ET-1 and ET-1 increased the mRNA levels and protein release of TIMP-1 and TIMP-3 mRNAs. The effects of ET-1 on astrocytic TIMP-1 and TIMP-3 mRNAs were inhibited by BQ788, an ET(B) antagonist. These findings indicate that activation of brain ET(B) receptors causes production of TIMP-1 and TIMP-3, and suggest the involvement of astrocytes in ET-induced TIMP production.     

Impaired migration of trophoblast cells caused by simvastatin is associated with decreased membrane IGF-I receptor, MMP2 activity and HSP27 expression

BACKGROUND: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme-A reductase, the rate-limiting enzyme of the mevalonate pathway, and are used successfully in the treatment of hypercholesterolaemia. Statins are contraindicated during pregnancy. Lately, we have shown that simvastatin has adverse affects on human first trimester placental explants' proliferation and migration. The objective of the present study was to investigate the molecules involved in mediating simvastatin's effect on trophoblast cell migration. We hypothesized that simvastatin attenuates insuline-like growth factor-I (IGF-I) receptor expression (involved in trophoblast motility), matrix metalloproteinase (MMP) activities, and heat shock protein 27 (HSP27) levels (whose mRNA is actively transcribed during trophoblast differentiation) in trophoblast cells thus consequently effecting their migration. METHODS: Human placental explants were cultured above a matrigel with/without simvastatin (10 microM) for 5 days. In this model, trophoblast migrates from the villi into the matrigel. Western-blot and immunohistochemistry served for analysing HSP27 expression. Immunohistochemistry was used for assessing IGF-I receptor localization. MMPs activity was assayed by gel zymography. RESULTS: Simvastatin reduced IGF-I receptor membranal expression, MMP2 activity and HSP27 expression in trophoblast cells (P < 0.05). CONCLUSIONS: The inhibitory effect of simvastatin on trophoblast cell migration is associated with a significant decrease in the tested molecules, which probably contributes to the impaired migration.     

Down‐regulation of KIF2A inhibits gastric cancer cell invasion via suppressing MT1‐MMP

Gastric cancer accounts for a sizeable proportion of global cancer mortality with high morbidity and poor prognosis. Kinesin superfamily proteins (KIFs) are microtubule‐dependent motor proteins that function as oncogenes in cancer cells, it has been discovered in recent years. Kinesin family member 2a (KIF2A), a member of the KIFs, has received attention for its role in carcinogenesis and its prognostic value in several human cancers such as breast cancer, colorectal cancer, and squamous cell carcinoma. However, the role of KIF2A in human gastric cancer remains unknown. In this study we aimed to explore the expression and biological functions of KIF2A in human gastric cancer cells, as well as to reveal its potential action mechanism. First, we found that KIF2A was markedly increased in gastric cancer cells (MKN‐28, MKN‐45, NCI‐N87 and SGC‐7901) compared to normal gastric mucosa epithelial cells (GES‐1). Then KIF2A was successfully silenced in MKN‐45 and SGC‐7901 cells to facilitate further research into its function. We discovered that KIF2A silencing can significantly inhibit the growth and invasion of MKN‐45 and SGC‐7901 cells in a time‐independent manner, accompanying a decreased expression of Membrane type 1‐matrix metalloproteinase (MT1‐MMP). When MT1‐MMP was reintroduced into MKN‐45 and SGC‐7901 cells in the KIF2A‐siRNA group, only invasion inhibition effects on MKN‐45 and SGC‐7901 cells induced by KIF2A silencing can be reversed. In conclusion, our study reveals that down‐regulation of KIF2A can inhibit gastric cancer cell invasion by suppressing MT1‐MMP.     

微创术对脑出血后脑水肿患者血浆明胶酶B的影响

目的探讨高血压性脑出血微创术对清除血肿后脑水肿患者血浆明胶酶B(MMP-9)的影响。方法127例脑出血患者随即分为内科治疗组60例、微创术血肿抽吸引流组67例;采用酶联免疫法(ELISA)测定脑出血后第3天、第7天和第21天血浆MMP-9含量。结果微创组和内科治疗组血浆中MMP-9含量均升高;两组治疗后第3、7天的含量与治疗前(发病24h内)比较,差异有统计学意义(P<0.05);两组治疗后不同时间点血浆中MMP-9含量比较,差异有统计学意义(P<0.05)。结论微创组能减少患者血浆MMP-9含量的增加。     

MTA1、MMP-9和TIMP-1蛋白与神经母细胞瘤侵袭转移相关性研究

目的探讨MTA1、MMP-9和TIMP-1蛋白与小儿神经母细胞瘤生物学行为之间的关系。方法运用免疫组化S—P法检测56例神经母细胞瘤组织中MTA1、MMP-9、TIMP—1蛋白的表达。结果56例神经母细胞瘤组织中37例MTA1阳性表达,阳性率为66．1％,MTA1高表达与神经母细胞瘤临床分期和转移关系密切（P〈0．05）;39例MMP-9蛋白阳性表达,阳性率为69．6％,MMP-9高表达与神经母细胞瘤临床分期和转移关系密切（P〈0．05）;27例TIMP—1蛋白阳性表达,阳性率为48．2％,TIMP-1低表达与神经母细胞瘤临床分期和转移关系密切（P〈0．05）;神经母细胞瘤组织中MMP-9,TIMP-1蛋白表达呈负相关（P〈0．05）。结论MTA1、MMP-9和TIMP-1蛋白表达与神经母细胞瘤恶性程度、转移和预后关系密切,可作为判断预后的指标,并有望为肿瘤靶向治疗提供理论依据。     

Association of MMP‐1 ‐1607 1G/2G (rs1799750) polymorphism with primary knee osteoarthritis in the Greek population

Osteoarthritis is the most common form of arthritis with still unknown pathogenic etiology and considerable contribution of genetic factors. One of the mechanisms of cartilage degradation in osteoarthritis is enzymatic proteolysis of the extracellular matrix by metalloproteinases. MMP‐1, produced by chondrocytes and synovial cells, is a major proteinase of the MMPs family. The present study aims at evaluating the association of MMP1 gene ‐1607 1G/2G (rs1799750) polymorphism with primary knee osteoarthritis in the Greek population. One hundred fifty five patients with primary symptomatic knee osteoarthritis participated in the study along with 139 controls. Genotypes were determined using PCR—RLFP technique. Allelic and genotypic frequencies were compared between both study groups. There was no significant association between MMP1 ‐1607 1G/2G polymorphism and knee osteoarthritis, in crude analysis; however, after multiple logistic regression analysis, 1G/2G was associated with reduced odds of knee osteoarthritis by 75% in males, compared to genotypes 1G/1G + 2G/2G, adjusting for age and BMI (adjusted OR: 0.25, 95% CI: 0.069, 0.910, p = 0.035). The present study shows that MMP1 ‐1607 1G/2G (rs1799750) polymorphism might be a risk factor for knee osteoarthritis susceptibility in the Greek population. Further investigations are needed to confirm this association in the pathogenesis of osteoarthritis. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1155–1160, 2014.

     

c-Jun NH2-terminal kinase-induced proteasomal degradation of c-FLIPL/S and Bcl2 sensitize prostate cancer cells to Fas- and mitochondria-mediated apoptosis by tetrandrine

Tetrandrine, a constituent of Chinese herb Stephania tetrandra, causes cell death in prostate cancer, but the molecular mechanisms leading to apoptosis is not known. Here we demonstrated that tetrandrine selectively inhibits the growth of prostate cancer PC3 and DU145 cells compared to normal prostate epithelial PWR-1E cells. Tetrandrine-induced cell death in prostate cancer cells is caused by reactive oxygen species (ROS)-mediated activation of c-Jun NH₂-terminal kinase (JNK1/2). JNK1/2-mediated proteasomal degradation of c-FLIP_L/S and Bcl₂ proteins are key events in the sensitization of prostate cancer cells to Fas- and mitochondria-mediated apoptosis by tetrandrine. Tetrandrine-induced JNK1/2 activation caused the translocation of Bax to mitochondria by disrupting its association with Bcl₂ which was accompanied by collapse of mitochondrial membrane potential (MMP), cytosolic release of cytochrome c and Smac, and apoptotic cell death. Additionally, tetrandrine-induced JNK1/2 activation increased the phosphorylation of Bcl₂ at Ser70 and facilitated its degradation via the ubiquitin-mediated proteasomal pathway. In parallel, tetrandrine-mediated ROS generation also caused the induction of ligand-independent Fas-mediated apoptosis by activating procaspase-8 and Bid cleavage. Inhibition of procaspase-8 activation attenuated the cleavage of Bid, loss of MMP and caspase-3 activation suggest that tetrandrine-induced Fas-mediated apoptosis is associated with the mitochondrial pathway. Furthermore, most of the signaling effects of tetrandrine on apoptosis were significantly attenuated in the presence of antioxidant N-acetyl-l-cysteine, thereby confirming the involvement of ROS in these events. In conclusion, the results of the present study indicate that tetrandrine-induced apoptosis in prostate cancer cells is initiated by ROS generation and that both intrinsic and extrinsic pathway contributes to cell death.     

Salvianolic acid B protects human endothelial progenitor cells against oxidative stress-mediated dysfunction by modulating Akt/mTOR/4EBP1, p38 MAPK/ATF2, and ERK1/2 signaling pathways

The vascular endothelium is specifically sensitive to oxidative stress, and this is one of the mechanisms that causes widespread endothelial dysfunction in most cardiovascular diseases and disorders. Protection against reactive oxygen species (ROS)-mediated oxidative damage via antioxidant mechanisms is essential for tissue maintenance and shows therapeutic potential for patients suffering from cardiovascular and metabolic disorders. Salvianolic acid B (SalB), a natural bioactive component known from Traditional Chinese Medicine, has been reported to exert cellular protection in various types of cells. However, the underlying mechanisms involved are not fully understood. Here, we showed that SalB significantly promoted the migratory and tube formation abilities of human bone marrow derived-endothelial progenitor cells (BM-EPCs) in vitro, and substantially abrogated hydrogen peroxide (H₂O₂)-induced cell damage. SalB down-regulated Nox4 and eNOS, as well as nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase expression upon H₂O₂ induction that in turn prevents oxidative-induced endothelial dysfunction. Moreover, SalB suppressed the Bax/Bcl-xL ratio and caspase-3 activation after H₂O₂ induction. Furthermore, our results provide mechanistic evidence that activation of the mTOR/p70S6K/4EBP1 pathways is required for both SalB-mediated angiogenic and protective effects against oxidative stress-induced cell injury in BM-EPCs. Suppression of MKK3/6-p38 MAPK-ATF2 and ERK1/2 signaling pathways by SalB significantly protected BM-EPCs against cell injury caused by oxidative stress via reduction of intracellular ROS levels and apoptosis. Taken together, by providing a mechanistic insight into the modulation of redox states in BM-EPCs by SalB, we suggest that SalB has a strong potential of being a new proangiogenic and cytoprotective therapeutic agent with applications in the field of endothelial injury-mediated vascular diseases.