Diagnostic value of serum neutrophil gelatinase-associated lipocalin,interleukin-6 and anti-citrullinated alpha-enolase peptide 1 for lower respiratory tract infections

ObjectivesThe aim of this study was to explore the auxiliary diagnostic value of neutrophil gelatinase-associated lipocalin (NGAL) and anti-citrullinated alpha-enolase peptide 1 (CEP-1) in lower respiratory tract infections (LRTIs).MethodsBlood samples were collected from 99 in-patients with LRTIs [62 community-acquired pneumonia (CAP), 14 acute exacerbated chronic obstructive pulmonary diseases (AECOPD), 23 other diseases] and 50 healthy subjects. NGAL, CEP-1 and IL-6 were measured and compared. IL-6 was tested by electrochemiluminescence assay kit on Roche E601 immunology analyzer, CEP-1 was assessed with enzyme-linked immunosorbent assay kit, and NGAL was detected by latex immunoturbidimetric assay kit on Beckman Coulter AU2700.ResultsCompared with healthy controls, NGAL and IL-6 levels were significantly increased in the patients with LRTIs, the area under the curves (AUC) was 0.97 and 0.88 respectively (P < 0.01). The sensitivity and specificity of NGAL at a cut-off of 86 ng/ml were 93.0% and 96.0%, respectively, in which the sensitivity was consistent with IL-6 (P = 0.21) and the specificity was better than IL-6 (P < 0.01). CEP-1 slightly increases in the patient group, however the difference was not significant (P = 0.41). The levels of NGAL and IL-6 was no differences in different diseases, the P-value was 0.50 and 0.29, respectively. LRTIs with and without underlying diseases have similar NGAL and IL-6 values.ConclusionsNGAL, rather than CEP-1, may be appealing adjuncts for diagnosis of LRTIs. NGAL proved to be a better biomarker than IL-6.     

抗内皮细胞抗体介导的内皮细胞损伤机制

目的探讨抗内皮细胞抗体（antiendothelial cell antibody，AECA）对内皮细胞凋亡的影响及重组α-烯醇化酶对内皮细胞凋亡的阻断作用。方法以EA．hy926细胞（内皮细胞永生细胞）提取物蛋白为抗原，采用免疫印迹法检测并筛选47000-AECA阳性患者血清，用蛋白G亲和层析法纯化IgG，在体外诱导内皮细胞凋亡，观察重组α-烯醇化酶对凋亡的阻断作用。结果含47000-AECA IgG在体外可诱导内皮细胞凋亡，荧光染色可见明显的核形态变化及典型的凋亡小体；含47000-AECA系统性红斑狼疮患者的IgG作用于EA．hy926细胞24、48和72小时后，凋亡率均明显高于相同剂量正常人kG作用EA．hy926细胞的凋亡率；而经重组α-烯醇化酶预处理后EA．hy926细胞凋亡率则明显降低。含47000-AECA IgG作用于EA．hy926细胞8小时后，AnnexinV^＋细胞数明显增加，并随IgG作用时间和浓度的增加而升高；而经重组α-烯醇化酶预处理的含47000-AECA IgG作用于EA．hy926细胞后，AnnexinV^＋细胞有所减少。结论AECA在体外可诱导内皮细胞凋亡，引起内皮细胞损伤；重组α-烯醇化酶可部分阻断47000-AECA体外诱导内皮细胞凋亡的作用，α-烯醇化酶是AECA识别的自身抗原之一。     

Alpha-烯醇化酶与疾病的相关性

alpha-烯醇化酶(α-enolase, ENO1)是原核及真核细胞内糖酵解过程中的限速酶,参与纤溶酶原的激活和纤溶酶活化过程,促进肌生成和肌肉再生,调控细胞增殖与凋亡等过程,其在细胞内外表达量的变化与疾病的发生发展过程密切相关,如阿尔兹海默病、类风湿关节炎、肿瘤、心血管疾病等。     

Identification of chemoresistant factors by protein expression analysis with iTRAQ for head and neck carcinoma

Background:

Cisplatin and other anticancer drugs are important in the treatment of head and neck squamous cell carcinoma; however, some tumours develop drug resistance. If chemoresistance could be determined before treatment, unnecessary drug administration would be avoided. Here, we investigated chemoresistance factors by comprehensive analyses at the protein level.

Methods:

Four human carcinoma cell lines were used: cisplatin-sensitive UM-SCC-23, UM-SCC-23-CDDPR with acquired cisplatin resistance, naturally cisplatin-resistant UM-SCC-81B, and UM-SCC-23/WR with acquired 5-fluorouracil resistance. Extracted proteins were labelled with iTRAQ and analysed by tandem mass spectrometry to identify resistance. Protein expression was confirmed by western blotting and functional analysis was carried out using siRNA.

Results:

Thirteen multiple-drug resistance proteins were identified, as well as seven proteins with specific resistance to cisplatin, including α-enolase. Differential expression of these proteins in cisplatin-resistant and -sensitive cell lines was confirmed by western blotting. Functional analysis for α-enolase by siRNA showed that cisplatin sensitivity significantly was increased in UM-SCC-81B and slightly in UM-SCC-23-CDDPR but not in UM-SCC-23/WR cells.

Conclusions:

We identified proteins thought to mediate anticancer drug resistance using recent proteome technology and identified α-enolase as a true cisplatin chemoresistance factor. Such proteins could be used as biomarkers for anticancer agent resistance and as targets of cancer therapy.