p38MAPK基因对胶质瘤细胞C6生长周期的影响

目的 研究p38MAPK基因对大鼠胶质瘤细胞C6生长周期的影响。方法 利用脂质体将p38MAPK基因导入C6细胞中，用免疫细胞化学染色检测其在转染前后的表达，用HE染色、流式细胞仪、TUNEL等研究其对细胞形态、粘着状况和生长周期的影响。结果 pCMV5-p38MAPK组P38MAPK蛋白表达阳性，细胞形态发生变化，贴壁性降低，G1期百分比增加，而S期和G2期百分比减低，并出现凋亡峰。结论 p38MAPK基因可影响C6细胞的生长周期，并诱导C6细胞凋亡。     

P38MAPK信号转导通路在大蒜素诱导THP-1细胞凋亡中的作用

目的:探讨大蒜素诱导THP-1细胞凋亡中P38MAPK及Fas基因表达的变化.方法:采用四甲基偶氮唑蓝(MTT)法测定不同浓度大蒜素对THP-1细胞增殖抑制率;Annexin V-FITC/PI双染法流式细胞术(FCM)检测凋亡率的变化;免疫细胞化学法观察大蒜素处理后细胞内磷酸化P38MAPK(P-p38MAPK)表达及分布变化;Western blot检测大蒜素处理前后细胞内P-p38MAPK和Fas蛋白表达量的变化.结果:MTT显示大蒜素能抑制THP-1细胞增殖,并呈时间-剂量依赖性.其72h中效浓度(IC_(50))为12.8 mg·L~(-1).Annexin V-FITC/PI检测凋亡率随大蒜素浓度增加而增加.免疫细胞化学法检测药物处理后P-p38MAPK表达增加,主要分布于细胞核与细胞浆,而阴性对照组仅弱表达.Western blot结果分析P-p38MAPK,Fas蛋白表达量随大蒜素浓度的增加而增加,呈剂量依赖性.其阴性组、72 h的1/2 IC_(50)组、IC_(50)组P-p38MAPK蛋白表达水平(相对灰度值)分别为0.259 8±0.013 2,0.361 2±0.008 3,0.505 6±0.005 5;Fas蛋白表达水平分别为0.287 4±0.008 9,0.426 8±0.007 9和0.597 1±0.010 9,差别均有显著性意义(P<0.01).结论:大蒜素可诱导THP-1细胞凋亡,其诱导凋亡机制可能是通过激活P-p38MAPK/Fas途径实现.     

Costello syndrome: Clinical phenotype,genotype, and management guidelines

Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence‐based guidelines due to the lack of data for this rare condition.     

Differential regulation of cytokine genes in gingival epithelial cells challenged by Fusobacterium nucleatum and Porphyromonas gingivalis

IL-8 mRNA in human gingival epithelial cells (HGECs) is up-regulated by Fusobacterium nucleatum, and up-/down-regulated by Porphyromonas gingivalis in a complex interaction in the early stages (< or = 4 h) after infection. The mechanisms involved in this regulation in response to F. nucleatum and/or P. gingivalis infection, and identification of co-regulated cytokine genes, are the focus of this investigation. Heat, formalin or protease treatment of F. nucleatum cells attenuated the IL-8 mRNA up-regulation. NF-kappaB, mitogen-activated protein kinase (MAPK) p38 and MAPK kinase/extracellular signal-regulated kinase (MEK/ERK) pathways were involved in IL-8 mRNA induction by F. nucleatum. Pretreatment of P. gingivalis with heat, formalin or protease enhanced IL-8 mRNA induction. NF-kappaB, MARK p38, and MEK/ERK pathways were also involved in this induction. In contrast, down-regulation of IL-8 mRNA by P. gingivalis involved MEK/ERK, but not NF-kappaB or MAPK p38 pathways. cDNA arrays analysis revealed that mRNA down-regulation by P. gingivalis is a specific reaction that only a number of genes, e.g. IL-1beta, IL-8, macrophage inflammatory protein-2alpha, and migration inhibitory factor-related protein-14, are affected based on examination of 278 cytokine/receptor genes. These data indicate that F. nucleatum and P. gingivalis trigger specific and differential gene regulation pathways in HGECs.     

Growth factor-dependent activation of the MAPK pathway in human pancreatic cancer: MEK/ERK and p38 MAP kinase interaction in uPA synthesis

Increased expression of the hepatocyte growth factor (HGF) receptor (c-met) and urokinase type plasminogen (uPA) correlated with the development and metastasis of cancers. To investigate the role of HGF/c-met signaling on metastasis in cancer cells stimulated with HGF, we examined the effects of a specific MEK1 inhibitor (PD98059) and a p38 MAP kinase inhibitor (SB203580) on HGF-induced uPA expression in pancreatic cancer cell lines, L3.6PL and IMIM-PC2. Pretreatment of PD98059 decreased HGF-mediated phosphorylation of extracellular receptor kinase (ERK), uPA secretion and expression of matrix metalloproteinases (MMP-2 and MMP-9) in a dose-dependent manner. In contrast, SB203580 pretreatment increased HGF-stimulated ERK phosphorylation, uPA secretion and expression of MMPs. SB203580 also reversed the inhibition of HGF-mediated ERK activation and uPA secretion in the PD98059-pretreated cells. These results suggest that ERK activation by HGF might play important roles in the metastasis of pancreatic cancer and the p38 MAPK pathway also involved in the HGF-mediated uPA secretion and metastasis by regulation of ERK pathway. This revised version was published online in July 2006 with corrections to the Cover Date.     

p38γMAPK蛋白在结肠癌组织中的表达及临床意义

目的探讨人结肠癌中p38γMAPK蛋白的表达及其临床意义。方法应用免疫组织化学法检测54例结肠癌组织、近癌旁组织、癌周正常组织和15例腺瘤息肉组织中p38γ蛋白的表达情况。结果p38γ蛋白的表达主要定位于胞质中,仅少量在胞核中表达。p38γ蛋白在结肠癌组织、癌旁组织、癌周正常组织中的高表达率分别为75.93%、51.85%、37.04%,在结肠腺瘤息肉组织中高表达率为33.33%。p38γ蛋白在结肠癌中的表达明显高于癌旁组织、癌周正常组织和腺瘤息肉组织,有统计学意义（P〈0.01）。p38γ的表达与Duke分期,组织分化程度及有无淋巴结转移有显著差异（P〈0.01）,p38γ的表达与年龄、性别、肿瘤大小、肿瘤位置无明显相关（P〉0.05）。结论结肠癌组织中p38γ蛋白处于过度表达状态,与结肠癌的发生、发展和转移密切相关。     

Role of caspases in dexamethasone-induced apoptosis and activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase in human eosinophils

Eosinophils are the principal effector cells for the pathogenesis of allergic inflammation. Glucocorticoids such as dexamethasone have long been used therapeutically for eosinophilia in allergic inflammation by inducing eosinophil apoptosis, but little is known about the intracellular mechanisms mediating dexamethasone-induced apoptosis. In the present study, we investigated the effect of dexamethasone on three mitogen-activated protein kinases (MAPK) involved in the intracellular signalling pathway: c-Jun NH2-terminal kinase (JNK), p38 MAPK and extracellular signal-regulated kinase (ERK). We found that dexamethasone could activate JNK and p38 MAPK in a time-dependent manner but not ERK. Further, SB 203580, a specific p38 MAPK inhibitor, was additive with dexamethasone in inducing eosinophil apoptosis, while JNK1/2 antisense phosphorothioate oligodeoxynucleotides did not show any significant effect. These suggest that dexamethasone-induced JNK1/2 and p38 MAPK activation are not crucial to the induction of apoptosis. Pretreatment of eosinophils with benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD.FMK), a broad-spectrum caspase inhibitor, could inhibit dexamethasone-induced apoptosis in eosinophils dose-dependently. Moreover, Z-VAD.FMK partially inhibited dexamethasone-activated JNK and p38 MAPK activities. However, dexamethasone treatment did not activate specific caspase-3, -8 activity in eosinophils compared with spontaneous apoptosis. We therefore conclude that dexamethasone-induced apoptosis and activation of JNK and p38 MAPK activity in eosinophils are regulated by caspases but not through the common apoptosis-related caspase-3, -8 as in other cell types. Elucidation of the important role of caspases in eosinophil apoptosis may facilitate the development of more specific and effective treatment for allergic inflammation.     

Fibronectin activates matrix metalloproteinase-9 secretion via the MEK1-MAPK and the PI3K-Akt pathways in ovarian cancer cells

Cell adhesion to the extracellular matrix appears to trigger a cascade of intracellular signalings. We have previously shown that treatment of ovarian cancer cells, NOM1, with fibronectin (FN) stimulated matrix metalloproteinase (MMP)-9 secretion and thereby activated the invasiveness of cells via the FAK/Ras signaling pathway. By use of chemical inhibitors, we investigated the downstream effectors critical for FN-dependent secretion of MMP-9. Treatment of cells with MEK1 inhibitors, U0126 and PD98059, dramatically suppressed the secretion of MMP-9 activated by FN. Similarly, PI-3 kinase inhibitors, Wortmannin and LY294002, strongly suppressed the FN-dependent secretion of MMP-9 together with the inhibition of Akt activation. In contrast, a specific PKC inhibitor (GF109203X) showed no inhibitory effect on the FN-dependent MMP-9 secretion. Moreover, we found that both the MEK1 inhibitor and the PI3-K inhibitor, but not the PKC inhibitor, strongly suppressed the invasiveness of NOM1 cells. Taken together, our results suggest that activation of dual signaling pathways, MEK1-MAPK and PI3K-Akt, is required for the FN-dependent activation of MMP-9 secretion. Our results suggest the importance of these signaling molecules as a chemotherapeutic target for cancer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cooperation between IL-7 and the pre-B cell receptor: a key to B cell selection

Hematopoiesis is regulated by a variety of signals that either originate within a developing cell or are supplied by the surrounding environment in secreted- or contact-dependent forms. This review discusses the effects of one secreted factor, interleukin-7, on the development of B lymphocytes. We describe a molecular mechanism for a crucial checkpoint during B lineage maturation, based on the integration of signals mediated by the pre-B cell receptor, the interleukin-7 receptor, and the environment in which these signals are received.     

Bradykinin differentiates human lung fibroblasts to a myofibroblast phenotype via the B2 receptor

BACKGROUND: The identification of factors mediating the transition of lung fibroblasts into myofibroblasts is considered fundamental in the comprehension of abnormal reparative processes. Bradykinin, a mediator known for its proinflammatory action, is able to induce cytokine production and contractility in fibroblast cultures. OBJECTIVES: In this study the ability of bradykinin to drive fibroblast into a myofibroblast phenotype at the cellular and molecular level was evaluated. METHODS: alpha-Smooth muscle actin (alpha-SMA) expression and TGF-beta in bradykinin stimulated fibroblasts were tested by means of flow cytometry, Western blot, and RT-PCR. Cell proliferation and collagen production were evaluated by the colorimetric methylthiazol tetrazolium assay and sirius red assay, respectively. Which bradykinin receptor mediates the expression of alpha-SMA was evaluated using selective B1 and B2 blocking agents. Furthermore, the effect of bradykinin on extracellular signal-regulated kinase 1/2 phosphorylation was explored. RESULTS: Bradykinin caused in lung fibroblasts a significant increase in alpha-SMA at the cellular and molecular level. The B2 receptor was held responsible for this effect because a specific receptor antagonist had entirely blocked this effect. Bradykinin was able to induce fibroblast proliferation and collagen production. Bradykinin significantly activated mitogen-activated protein kinase pathway by phosphorylating extracellular signal-regulated kinase 1/2, whereas PD98059, a specific inhibitor, was able to block myofibroblast induction. Although bradykinin induced an increase of TGF-beta on fibroblasts, the blockage of this cytokine did not alter alpha-SMA expression. CONCLUSION: The data support the hypothesis that bradykinin may be involved in bronchial remodeling and lung fibrosis beyond its well recognized proinflammatory activity, also suggesting a new potential therapeutic strategy to control altered reparatory processes.