多发性脑梗死性痴呆相关因素和P_(300)的研究

目的 探讨多发性脑梗死性痴呆（ＭＩＤ）的相关因素及Ｐ３００对ＭＩＤ的诊断意义。方法 对３８ 例ＭＩＤ和３２ 例无痴呆脑梗死患者的受教育程度、既往史、梗死部位进行对比分析，并用听觉Ｏｄｄ－ｂａｌｌ序列测试Ｐ３００。结果 ＭＩＤ组受教育程度低、高血压史、糖尿病史、≥２ 次卒中史、皮质梗死、皮质合并皮质下梗死、多发性梗死、双侧梗死者与对照组相比均有显著差异（Ｐ＜ ０．０５～０．０１）。ＭＩＤ组Ｐ３００潜伏期明显延长，波幅显著降低。结论 文化水平低、高血压、糖尿病、反复卒中是ＭＩＤ的危险因素。皮质梗死、皮质合并皮质下梗死、多发性梗死、双侧梗死与ＭＩＤ的发生有关。对ＭＩＤ认知功能损害的判断，Ｐ３００ 是一种客观的、有实用价值的电生理学指标。

正常人年龄、性别与听觉P_(300)的关系

目的 探讨正常人年龄、性别因素对听觉事件相关电位中P3 0 0 的影响。方法 对 6 0名不同年龄组正常人进行听觉P3 0 0 测试 ,记录其潜伏期 (PL)和波幅 (Amp) ,并对数据进行统计学处理。结果 <5 9岁的两组正常人分别与≥ 6 0岁组正常人相比 ,P3 0 0 潜伏期和波幅的差异均有显著性。直线相关分析提示 :全年龄组内P3 0 0 的潜伏期和波幅分别与年龄呈正、负相关关系。 6 0名正常人中P3 0 0 各成分在性别上的差异无显著性。结论 年龄对P3 0 0 的潜伏期及波幅均有影响 ,随着年龄的增加 ,PL延长 ,Amp降低 ;但性别对P3 0 0

Roles of CREB-binding protein (CBP)/p300 in respiratory epithelium tumorigenesis

CREB-binding protein （CBP） and its homologue p300 are transcriptional co-activators of various sequence-specific transcription factors that are involved in a wide array of cellular activities, such as DNA repair, cell growth, differentia- tion and apoptosis. Several studies have suggested that CBP and p300 might be considered as tumour suppressors, with their prominent role being the cross-coupling of distinct gene expression patterns in response to various stimuli. They exert their actions mainly via acetylation of histones and other regulatory proteins （e.g. p53）. A major paradox in CBP/ p300 function is that they seem capable of contributing to various opposed cellular processes. Respiratory epithelium tumorigenesis represents a complex process of multi-step accumulations of a gamut of genetic and epigenetic aberrations. Transcription modulation through the alternate formation of activating and repressive complexes is the ultimate converging point of these derangements, and CBP/p300 represents key participants in this interplay. Thus, illumination of their molecular actions and interactions could reveal new potential targets for pharmacological interventions in respiratory epithelium carcinogenesis.

The gene expression patterns of BMPR2,EP300,TGFβ2,and TNFAIP3 in B-Lymphoma cells

Objective: The results of a previous study showed that a clear dysregulation was evident in the global gene expression of the BCL11A-suppressed B-lymphoma cells. In this study, the bone morphogenetic protein receptor, type II(BMPR2), E1 A binding protein p300(EP300), transforming growth factor-β2(TGFβ2), and tumor necrosis factor, and alpha-induced protein 3(TNFAIP3) gene expression patterns in B-cell malignancies were studied. Methods: The relative expression levels of BMPR2, EP300, TGFβ2, and TNFAIP3 mRNA in B-lymphoma cell lines, myeloid cell lines, as well as in cells from healthy volunteers, were determined by real-time quantitative reverse transcriptpolymerase chain reaction(qRT-PCR) with SYBR Green Dye. Glyceraldehyde-3-phosphate dehydrogenase(GAPDH) was used as reference. Results: The expression level of TGFβ2 mRNA in B-lymphoma cell lines was significantly higher than those in the cells from the healthy control(P<0.05). However, the expression level of TNFAIP3 mRNA in B-malignant cells was significantly lower than that of the healthy control(P<0.05). The expression levels of BMPR2 and EP300 mRNA showed no significant difference between B-malignant cell lines and the healthy group(P>0.05). In B-lymphoma cell lines, correlation analyses revealed that the expression of BMPR2 and TNFAIP3(r=0.882, P=0.04) had significant positive relation. The expression levels of BMPR2, EP300, and TNFAIP3 mRNA in cell lines from myeloid leukemia were significantly lower than those in the cells from the healthy control(P<0.05). The expression levels of TGFβ2 mRNA showed no significant difference between myeloid leukemia cell lines and the healthy control or B-malignant cell lines(P>0.05). The expression levels of BMPR2, EP300, and TNFAIP3 mRNA in B-lymphoma cells were significantly higher than those of the myeloid leukemia cells(P<0.05).Conclusion: Different expression patterns of BMPR2, EP300, TGFβ2, and TNFAIP3 genes in B-lymphoma cells exist.

CITED2 and the modulation of the hypoxic response in cancer

CITED2(CBP/p300-interacting transactivator with Glu/Asp-rich C-terminal domain,2)is a ubiquitously expressed protein exhibiting a high affinity for the CH1 domain of the transcriptional co-activators CBP/p300,for which it competes with hypoxia-inducible factors(HIFs).CITED2 is particularly efficient in the inhibition of HIF-1α-dependent transcription in different contexts,ranging from organ development and metabolic homeostasis to tissue regeneration and immunity,being also potentially involved in various other physiological processes.In addition,CITED2 plays an important role in inhibiting HIF in some diseases,including kidney and heart diseases and type 2-diabetes.In the particular case of cancer,CITED2 either functions by promoting or suppressing cancer development depending on the context and type of tumors.For instance,CITED2 overexpression promotes breast and prostate cancers,as well as acute myeloid leukemia,while its expression is downregulated to sustain colorectal cancer and hepatocellular carcinoma.In addition,the role of CITED2 in the maintenance of cancer stem cells reveals its potential as a target in non-small cell lung carcinoma and acute myeloid leukemia,for example.But besides the wide body of evidence linking both CITED2 and HIF signaling to carcinogenesis,little data is available regarding CITED2 role as a negative regulator of HIF-1αspecifically in cancer.Therefore,comprehensive studies exploring further the interactions of these two important mediators in cancer-specific models are sorely needed and this can potentially lead to the development of novel targeted therapies.

Role of Acetylated p53 in Regulating the Expression of map2 in Retinoic Acid-induced P19 Cells

Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods Neuronal differentiation of P19 cells was initiated with 4-day RA treatment.Immunofluorescence,real-time reverse transcription-polymerase chain reaction(RT-PCR) assay,and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells.Real-time PCR-based chromatin immunoprecipitation assay(ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter.Results The expression of MAP2 was markedly increased in RA-induced P19 cells.The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment,compared with the cells without RA treatment(control).p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity.p300/CBP associated factor(PCAF) was found induced in RA-treated cells and enriched in the nucleus,which might contribute to the acetylation of p53 in the regulation of map2 gene.Conclusions Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells.PCAF is possibly involved in this process by mediating the acetylation of p53.

Relationships among Event-Related Potentials, Memory, and Schizophrenic Symptoms in College Students with Schizotypal-Traits

The present study investigated the relationships among event-related potentials (ERPs), memory, and schizophrenic symptoms in college students with schizotypal-traits. Scores on the Schizotypal Personality Questionnaire (SPQ) were used to categorize the participants into schizotypal-trait (n = 30) and normal control (n = 37) groups. ERPs were assessed using an auditory oddball paradigm, in which a series of standard tones (1000 Hz) and target tones (1500 Hz) were presented;participants were asked to count the number of presented target tones. The verbal memory and visual memory of the participants were evaluated using the Korean version of the California Verbal Learning Test (K-CVLT) and the Rey-Osterrieth Complex Figure Test (RCFT), respectively. The schizotypal-trait and control groups did not differ in terms of age, educational level, IQ score, accuracy on the auditory oddball task, or performance on the K-CVLT and RCFT measures. However, the schizotypal-trait group exhibited significantly smaller P300 amplitudes than the control group. Additionally, the P300 amplitudes measured at Cz and Pz were negatively correlated with the cognitive-perceptual factor scores on the SPQ. Thus, the present results indicate that reduced P300 amplitudes may represent a biological marker of schizophrenia.

Regulation of the cell fate by DNA damage and hypoxia

In order to provide the means for the design of novel rational anti-cancer drug therapies research efforts are concentrated on unravelling the molecular circuits which induce programmed cell death and block proliferation of cancer cells.Modern therapeutic strategies are based on the understanding of the complexity of physiological functions such as differentiation,development,immune responses,cell-cycle arrest,DNA damage repair,apoptosis,autophagy,energy metabolism,and senescence.It has become evident that this knowledge will provide the means to target the components of the pathways involved in these processes in a specific and selective manner thus paving the way for the development of effective and personalised anti-cancer therapies.Transcription is a crucial cellular process that regulates a multitude of physiological functions,which are essential in disease progression and cellular response to therapy.Transcription factors such as the p53 tumor suppressor and the hypoxia-inducible factor-α(HIF-α) are key players in carcinogenesis and cellular response to cancer therapies.Both of these transcription factors regulate gene expression of genes involved in cell death and proliferation,in some cases cooperating towards producing the same outcome and in some others mediating opposing effects.It is thus apparent that fine tuning of the activity of these transcription factors is essential to determine the cellular response to therapeutic regimens,in other words whether tumor cells will commit to apoptosis or evade engagement with the anti-proliferative effects of drugs leading to drug resistance.Our observations support the notion that the functional crosstalk between HIF-1α and p53 pathways and thus the fine tuning of their transcriptional activity is mediated by cofactors shared between the two transcription factors such as components of the p300 co-activator multiprotein complex.In particular,there is evidence to suggest that differential composition of the co-modulatory protein complexes associated with p53 and HIF-la under diverse types of stress conditions differentially regulate the expression of distinct subsets of p53 and HIF-la target genes involved in processes such as cell cycle arrest,apoptosis,chronic inflammation,and cellular energy metabolism thereby determining the cellular fate under particular types of microenvironmental stress.

P300/CBP-associated factor(PCAF)-mediated acetylation of Fascin at lysine 471 inhibits its actin-bundling activity and tumor metastasis in esophageal cancer

Background:Fascin is crucial for cancer cell filopodium formation and tumor metastasis,and is functionally regulated by post-translational modifications.However,whether and how Fascin is regulated by acetylation remains unclear.This study explored the regulation of Fascin acetylation and its corresponding roles in filopodium formation and tumor metastasis.Methods:Immunoprecipitation and glutathione-S-transferase pull-down assays were performed to examine the interaction between Fascin and acetyltransferase P300/CBP-associated factor(PCAF),and immunofluorescence was used to investigate their colocalization.An in vitro acetylation assay was performed to identify Fascin acetylation sites by using mass spectrometry.A specific antibody against acetylated Fascin was generated and used to detect the PCAF-mediated Fascin acetylation in esophageal squamous cell carcinoma(ESCC)cells using Western blotting by overexpressing and knocking down PCAF expression.An in vitro cell migration assay was performed,and a xenograft model was established to study in vivo tumor metastasis.Live-cell imaging and fluorescence recovery after photobleaching were used to evaluate the function and dynamics of acetylated Fascin in filopodium formation.The clinical significance of acetylated Fascin and PCAF in ESCC was evaluated using immunohistochemistry.Results:Fascin directly interacted and colocalized with PCAF in the cytoplasm and was acetylated at lysine 471(K471)by PCAF.Using the specific antiAcK471-Fascin antibody,Fascin was found to be acetylated in ESCC cells,and the acetylation level was consequently increased after PCAF overexpression and decreased after PCAF knockdown.Functionally,Fascin-K471 acetylation markedly suppressed in vitro ESCC cell migration and in vivo tumor metastasis,whereas Fascin-K471 deacetylation exhibited a potent oncogenic function.Moreover,Fascin-K471 acetylation reduced filopodial length and density,and lifespan of ESCC cells,while its deacetylation produced the opposite effect.In the filipodium shaft,K471-acetylated Fascin displayed rapid dynamic exchange,suggesting that it remained in its monomeric form owing to its weakened actinbundling activity.Clinically,high levels of AcK471-Fascin in ESCC tissues were strongly associated with prolonged overall survival and disease-free survival of ESCC patients.Conclusions:Fascin interacts directly with PCAF and is acetylated at lysine 471 in ESCC cells.Fascin-K471 acetylation suppressed ESCC cell migration and tumor metastasis by reducing filopodium formation through the impairment of its actin-bundling activity.

Reversible acetylation regulates vascular endothelial growth factor receptor-2 activity

The tyrosine kinase receptor vascular endothelial growth factor receptor 2 （VEG FR2） is a key regulator of angiogenesis. Here we show that VEGFR2 is acetylated in endothelial cells both at four lysine residues forming a dense cluster in the kinase insert domain and at a single lysine located in the receptor activation loop. These modifications are under dynamic control of the acetyltransferase p300 and two deacetyiases HDAC5 and HDAC6. We demonstrate that VEGFR2 acetylation essentially regulates receptor phosphorylation. In par- ticular, VEGFR2 acetylation significantly alters the kinetics of receptor phosphorylation after ligand binding, allowing receptor phos- phoryiation and intraceUular signaling upon proLonged stimulation with VEGF. Molecular dynamics simulations indicate that acetylation of the lysine in the activation loop contributes to the transition to an open active state, in which tyrosine phosphorylation is favored by better exposure of the kinase target residues. These findings indicate that post-translational modification by acetyiation is a critical mechanism that directLy affects VEGFR2 function.