MiR-129-5p靶向抑制高迁移率族蛋白B1表达增加甲状腺髓样细胞MZ-CRC-1放射敏感性的实验研究

目的 探讨miR-129-5p靶向抑制高迁移率族蛋白B1（HMGB1）对甲状腺髓样细胞MZ-CRC-1放射敏感性的影响机制。方法 建立抗辐射细胞株MZ-CRC-1/R;克隆形成实验分析细胞存活分数;qRT-qPCR检测miR-129-5p在MZ-CRC-1和MZ-CRC-1/R细胞中的表达;噻唑蓝（MTT）法检测细胞活力;流式细胞术检测细胞凋亡;双荧光酶报告基因实验验证miR-129-5p与高迁移率族蛋白B1（HMGB1）之间的靶向关系;Western blot检测HMGB1和p-AKt的蛋白表达。结果 与MZ-CRC-1细胞相比,MZ-CRC-1/R细胞的细胞存活分数显著提高（t=3.038、4.330、4.885、4.568,P<0.05）;细胞活力增加（t=3.637、7.734、11.896、14.522,P<0.05）;与MZ-CRC-1细胞（1.00±0.06）相比,miR-129-5p在MZ-CRC-1/R细胞中的表达（0.26±0.03）显著降低（t=19.107,P<0.05）;与miR-NC-inhibitor组细胞相比,miR-129-5p-inhibitor组细胞的细胞活力显著增加（t=5.156、6.005、9.649,P<0.05）,细胞凋亡率降低（t=8.659,P<0.05）。与miR-NC组细胞相比,miR-129-5p mimic组细胞的细胞活力显著降低（t=3.118、5.034、6.005、7.488,P<0.05）,细胞凋亡率升高（t=6.362,P<0.05）;过表达miR-129-5p可抑制HMGB1及p-AKt信号通路的表达（t=9.325、10.614,P<0.05）;与miR-129-5p inhibitor组细胞相比,miR-129-5p inhibitor+si-HMGB1组细胞的细胞凋亡率显著升高（t=6.700,P<0.05）;与miR-129-5p mimic组细胞相比,miR-129-5p mimic+si-HMGB1组细胞的细胞凋亡率显著降低（t=7.073,P<0.05）。结论 miR-129-5p可靶向抑制HMGB1增加甲状腺髓样细胞MZ-CRC-1的放射敏感性。     

In vitro amplification and detection of variant Creutzfeldt-Jakob disease PrPSc

Variant Creutzfeldt-Jakob disease (vCJD) poses a serious risk of secondary transmission and the need to detect infectivity in asymptomatic individuals is therefore of major importance. Following infection, it is assumed that minute amounts of disease-associated prion protein (PrP(Sc)) replicate by conversion of the host cellular prion protein (PrP(C)). Therefore, methods of rapidly reproducing this conversion process in vitro would be valuable tools in the development of such tests. We show that one such technique, protein misfolding cyclic amplification (PMCA), can amplify vCJD PrP(Sc) from human brain tissue, and that the degree of amplification is dependent upon the substrate PRNP codon 129 polymorphism. Both human platelets and transgenic mouse brain are shown to be suitable alternative substrate sources, and amplified PrP(Sc) can be detected using a conformation-dependent immunoassay (CDI), allowing the detection of putative proteinase K sensitive forms of PrP(Sc).     

MiR-129-5p通过靶定胸苷酸合成酶调节结肠癌细胞对5-氟尿嘧啶的敏感性

目的 研究miR-129-5p通过靶定胸苷酸合成酶（TYMS）调控结肠癌细胞对5-氟尿嘧啶（5-Fu）敏感性的分子机制.方法 构建结肠癌耐药细胞株LoVo/5-Fu,并用实时荧光定量聚合酶链反应（PCR）检测miR-129-5p的表达水平.流式细胞术和MTT毒性实验检测过表达miR-129-5p对LoVo/5-Fu凋亡和半数致死剂量（IC50）的影响.构建TYMS 3＇UTR区荧光素酶报告载体,验证miR-129-5p对TYMS的靶向调控作用.Western Blot检测转染miR-129-5p后LoVo/5-Fu细胞中TYMS的蛋白表达.在LoVo/5-Fu内转染miR-129-5P siRNA,抑制其表达,检测LoVo/5-Fu细胞的IC50和凋亡.结果 过表达miR-129-5p后,LoVo/5-Fu细胞用5-Fu处理后凋亡增加,IC50降低.荧光素酶活性检测表明miR-129-5p能够抑制TYMS的荧光素酶活性.在LoVo/5-Fu细胞中miR-129-5p与TYMS的表达呈负相关.敲减TYMS后,LoVo/5-Fu细胞用5-Fu处理后凋亡增加,IC50降低.结论 MiR-129-5p能够通过靶定TYMS而增加结肠癌细胞对5-Fu的敏感性.     

Simultaneous assessment of both lung morphometry and gas exchange function within a single breath‐hold by hyperpolarized 129Xe MRI

During the measurement of hyperpolarized ¹²⁹Xe magnetic resonance imaging (MRI), the diffusion‐weighted imaging (DWI) technique provides valuable information for the assessment of lung morphometry at the alveolar level, whereas the chemical shift saturation recovery (CSSR) technique can evaluate the gas exchange function of the lungs. To date, the two techniques have only been performed during separate breaths. However, the request for multiple breaths increases the cost and scanning time, limiting clinical application. Moreover, acquisition during separate breath‐holds will increase the measurement error, because of the inconsistent physiological status of the lungs. Here, we present a new method, referred to as diffusion‐weighted chemical shift saturation recovery (DWCSSR), in order to perform both DWI and CSSR within a single breath‐hold. Compared with sequential single‐breath schemes (namely the ‘CSSR + DWI’ scheme and the ‘DWI + CSSR’ scheme), the DWCSSR scheme is able to significantly shorten the breath‐hold time, as well as to obtain high signal‐to‐noise ratio (SNR) signals in both DWI and CSSR data. This scheme enables comprehensive information on lung morphometry and function to be obtained within a single breath‐hold. In vivo experimental results demonstrate that DWCSSR has great potential for the evaluation and diagnosis of pulmonary diseases.