Clusterin/Apolipoprotein J up-regulation after zinc exposure, replicative senescence or differentiation of human haematopoietic cells

Clusterin/Apolipoprotein J (CLU) is a cellular senescence biomarker implicated in several physiological processes. In this work we have investigated CLU expression and function in human haematopoietic cells. We found that early passage human T cell clones (TCC) express minimal endogenous amounts of CLU, which are significantly elevated in late passage cells. Moreover, exposure of TCC to increased levels of the essential micronutrient zinc in culture resulted in intense induction of CLU. Because haematopoietic cells cease proliferation following induction of terminal differentiation, we also studied the expression profile of CLU in the leukemic progenitor cell lines K562 and HL-60. We found that, like TCC, both cell lines express minimal endogenous levels of CLU in their actively proliferating state. However, when induced to differentiate into their distinct cell types, CLU was found to be up-regulated specifically in those cells expressing the main differentiation markers. Enforced stable over-expression of CLU in K562 cells inhibited the expression of the CD14 differentiation marker and blocked differentiation to either monocytes/megacaryoblasts or to erythrocytes. Overall, our results suggest that CLU is actively involved in both replicative senescence and terminal differentiation in different types of human haematopoietic cells.Presented at the ZincAge Conference, Madrid, February 10–13, 2006.     

簇素在急性胰腺炎发病机制中的研究进展

簇素是一种普遍存在的异源二聚体硫酸化糖蛋白,目前研究推测簇素参与调节急性胰腺炎发病中胰腺细胞的凋亡、拮抗细胞坏死及抑制补体对细胞膜的攻击,进而减轻炎症反应,同时参与损伤胰腺细胞的再生和修复,最终保护胰腺组织。现认为,簇素在急性胰腺炎中是一种保护细胞的蛋白质。     

聚集素在前列腺癌中的表达及意义

目的　探讨抗细胞凋亡因子聚集素 (clusterin)在前列腺癌中的表达及意义。　方法　RT PCR方法检测聚集素在前列腺癌组织 (3例 )、癌细胞系 (1株 )及正常前列腺组织 (3例 )中的表达水平。　结果　 3例前列腺癌组织及 1例前列腺癌细胞株中聚集素与内参基因 β actin相比较的相对表达量明显高于 3例正常前列腺组织。　结论　聚集素在前列腺癌中高表达 ,提示聚集素可能通过抗凋亡机制在前列腺癌的生物特性中发挥作用。     

肝细胞癌组织中高尔基体糖蛋白73和分泌型聚集素的表达及其相关性分析

背景与目的：肝细胞癌(hepatocellular carcinoma,HCC)是一种具有高度侵袭、转移性的常见恶性肿瘤,预后极差。因此,研究肝癌侵袭的机制,寻找有效的干预靶点显得尤为重要。一些研究提示分泌型聚集素(secreted Clusterin,sCLU)和高尔基体糖蛋白73(Golgi glycoprotein 73,GP73)在肿瘤发生、发展及侵袭、转移过程中起重要作用,且两者具有结构和功能上的相似性。本研究旨在探讨GP73和sCLU在HCC中的表达及其与临床病理特征和预后之间的关系。方法：收集新疆医科大学第一附属医院75例HCC患者癌组织及癌旁正常肝组织标本,采用免疫组化(EnVision二步法)检测HCC组织中GP73、sCLU的表达水平;并与癌旁正常肝组织相比较;Spearman等级相关分析GP73和sCLU在肝癌中表达的关系;研究GP73和sCLU表达水平与HCC临床病理特征及预后的关系。结果：GP73和sCLU在HCC中阳性表达率分别为72%和88%,癌旁正常肝组织的阳性表达率均为4%。GP73在HCC和正常肝组织中阳性表达差异有统计学意义(χ²=73.60,P<0.05)。sCLU在HCC和正常肝组织中阳性表达差异有统计学意义(χ²=207.94,P<0.05);Spearman等级相关分析提示,HCC组织中,GP73和sCLU蛋白表达呈正相关(r=0.405,P<0.05);GP73和sCLU在HCC中表达水平与肿瘤的Edmondson病理分级、TNM分期及血管侵犯相关(P<0.05),而与患者的性别、年龄、HBsAg、合并肝硬化、AFP值、门静脉癌栓、肿瘤数目无相关性(P>0.05);GP73表达与患者生存期有关,而sCLU表达与患者生存期无关。结论：GP73和sCLU在肝癌中有较高的阳性率,且GP73和sCLU表达呈正相关,GP73和sCLU可能与HCC的侵袭性等生物行为密切相关,检测其表达将有助于评价患者预后。     

Neural hyperactivation in carriers of the Alzheimer's risk variant on the clusterin gene

Recent GWAS identified a risk variant for Alzheimer's disease (AD) at a locus (rs11136000) of the clusterin gene (CLU). Here we use functional magnetic resonance imaging (fMRI) during working memory to probe the effect of the risk variant on brain activation in healthy individuals. Participants with the CLU risk genotype had higher activity than participants with the protective allele in frontal and posterior cingulate cortex and the hippocampus, particularly during high memory demand. These results inform pathophysiological models of the preclinical progression of AD.     

肥大细胞、Clusterin/apoJ和转化生长因子-β在不同时期血管瘤中的表达及相关性

目的探讨肥大细胞、Clusterin/apoJ和转化生长因子-β（TGF-β）在不同时期血管瘤发生、发展过程中的表达及相关性。方法采用免疫组织化学方法检测不同时期血管瘤中Clusterin/apoJ、TGF-β的表达水平以及采用甲苯胺蓝染色法对各期肥大细胞进行染色。结果增生晚期肥大细胞计数明显多于增生早、中期（P<0.01）,退化早期肥大细胞计数明显多于退化中、晚期（P<0.01）。Clusterin/apoJ和TGF-β在增生晚期的表达明显强于其在增生早、中期的表达（P<0.01）,在退化早期的表达明显强于其在退化中、晚期的表达（P<0.01）。不同时期中肥大细胞计数与Clusterin/apoJ和TGF-β表达的平均阳性面积率间具有显著正相关性（P<0.01）,不同时期中Clusterin/apoJ和TGF-β表达的平均阳性面积率间具有显著正相关性（P<0.01）。结论肥大细胞可能对血管瘤的消退进程起促进作用。Clusterin/apoJ和TGF-β可能具有促进血管内皮细胞凋亡,发挥促进血管瘤消退的作用;TGF-β可能通过正性调节Clusterin/apoJ的表达而发挥促进血管瘤自然消退的作用。     

聚集素抗LNCaP细胞凋亡作用的研究

目的研究聚集素抗LNCaP细胞凋亡的作用及聚集素反义寡核苷酸(AS-ODN)对肿瘤坏死因子-α(TNF-α)细胞毒性作用的影响。方法培养转染全长聚集素序列的LNCaP细胞(A)为实验组,野生型LNCaP细胞(L)及转染PIRES2-EGFP空载体的LNCaP细胞(M)为对照组,以20 ng/ml TNF-α进行诱导,MTT及ELISA法检测3组细胞增殖活性与凋亡程度；转染聚集素AS-ODN后A细胞分4组,①对照组：常规培养；②AS-ODN组：转染AS-ODN,培养液不含TNF-α；③TNF-α组：未转染AS-ODN,培养液含20ng/ml TNF-α；④TNF-α+AS-ODN组：转染AS-ODN,培养液含20ng/ml TNF-α,观察4组细胞增殖活性与凋亡程度的变化。结果L、M、A3组细胞增殖活性分别为0.84±0.03、0.85±0.04、0.95±0.03,L与M间差异无统计学意义(P＞0.05),L、M与A相比增殖活性显著降低(P值均＜0.01)。3组细胞ELISA吸光度值分别为0.59±0.04、0.62±0.03、0.33±0.04,L与M间差异无统计学意义(P＞0.05),但L、M与A相比凋亡程度显著增高(P值均＜0.01)。A细胞①～④组细胞增殖活性吸光度值分别为1.30±0.03,1.25±0.03,0.99±0.03,0.80±0.03,两两比较组间差异均有统计学意义(P值均＜0.05)；4组细胞凋亡程度吸光度值分别为0.02±0.00,0.21±0.02,0.63±0.07,1.16±0.04,两两比较组间差异均有统计学意义(P值均＜0.01)。结论转染并永久表达全长序列聚集素后,TNF-α对LNCaP细胞的细胞毒性作用显著降低,转染聚集素AS-ODN显著增强TNF-α的细胞毒性作用,聚集素具有抗LNCaP细胞凋亡的作用。     

Seminal level of clusterin in infertile men as a significant biomarker reflecting spermatogenesis

The objective of this study was to assess the impact of seminal clusterin level on spermatogenesis in infertile men. This study included 89 men who visited our clinic due to infertility, consisting of 28, 33, and 28 diagnosed with normospermia, oligozoospermia and nonobstructive azoospermia (NOA) respectively. The seminal clusterin concentrations measured by enzyme‐linked immunosorbent assay were 47.9, 28.2 and 18.4 ng ml^?1 in men with normospermia, oligozoospermia and NOA, respectively, with significant differences among these three groups (P < 0.01). Microdissection testicular sperm extraction (MD‐TESE) was performed in the 28 men with NOA, and spermatozoon was successfully retrieved from 9. There was a significant correlation between seminal clusterin level and testicular clusterin protein expression evaluated by immunohistochemical staining in these men with NOA (P = 0.026). Of several parameters available before MD‐TESE, the univariate analysis identified serum follicle‐stimulating hormone (FSH) level <10 IU ml^?1 and seminal clusterin level ≥18 ng ml^?1 as significant predictors of sperm retrieval, and of these, only serum FSH level <10 IU ml^?1 was shown to be independently associated with sperm retrieval in the multivariate analysis. Accordingly, it might be worthy to further evaluate the significance of seminal clusterin level as a biomarker for the assessment of spermatogenic status in infertile men.     

Neuronal intranuclear inclusion disease in a horse

Neuronal intranuclear inclusion disease (NIID) is reported in a 16-year-old Pure Spanish breed female horse suffering from progressive ataxia and motor deficiencies. The neuropathological study revealed NIIs throughout the central nervous system, although mainly in the brain stem and spinal cord. This distribution did not correlate with neuron loss, which was marked in the hippocampus and moderate in the neocortex, particularly in the occipital cortex. As in humans, NIIs in the horse were hyaline autofluorescent inclusions composed of non-membrane-bound aggregates of filaments and fine granules. NIIs were stained with anti-ubiquitin and anti-clusterin antibodies. In addition, NIIs were stained with antibodies raised against subunits of the 19S and PA28, but not of the 20S, components of the proteasome. These observations indicate similarities between NIID in humans and horses, and suggest that clusterin and abnormal ubiquitin-proteasomal expression participate in NII formation.     

Involvement of clusterin expression in the refractory response of pancreatic cancer cells to a MEK inhibitor

Constitutive activation of the mitogen-activated protein kinase (MAPK) signaling pathway is essential for tumorigenesis of pancreatic ductal adenocarcinoma (PDAC). To date, however, almost all clinical trials of inhibitor targeting this pathway have failed to improve the outcome of patients with PDAC. We found that implanted MIA Paca2, a human PDAC cell line sensitive to a MAPK inhibitor, PD0325901, became refractory within a week after treatment. By comparing the expression profiles of MIA Paca2 before and after acquisition of the refractoriness to PD0325901, we identified clusterin (CLU) as a candidate gene involved. CLU was shown to be induced immediately after treatment with PD0325901 or expressed primarily in more than half of PDAC cell lines, enhancing cell viability by escaping from apoptosis. A combination of PD0325901 and CLU downregulation was found to synergistically or additively reduce the proliferation of PDAC cells. In surgically resected PDAC tissues, overexpression of CLU in cancer cells was observed immunohistochemically in approximately half of the cases studied. Collectively, our findings highlight the mechanisms responsible for the rapid refractory response to MEK inhibitor in PDAC cells, suggesting a novel therapeutic strategy that could be applicable to patients with PDAC using inhibitor targeting the MAPK signaling pathway and CLU.