多聚嘧啶序列结合蛋白相关剪接因子对缺氧诱导人视网膜微血管内皮细胞功能的影响

目的观察多聚嘧啶序列结合蛋白相关剪接因子(PSF)对缺氧诱导的人视网膜微血管内皮细胞(hRMECs)功能的影响。方法采用三质粒系统构建慢病毒颗粒(LV)-PSF。LV-PSF体外感染hRMECs后通过流式细胞计数法测定其感染效率。应用实时定量PCR(RT-PCR)检测经LV-PSF感染的hRMECs中PSF mRNA表达水平。将实验分为体内和体外两部分。体内实验:7日龄健康C57B/L6小鼠20只,采用随机数字表法分为正常组、氧诱导视网膜病变(OIR)组、OIR+LV-空载体(Vec)组和OIR+LV-PSF组,每组5只。除正常组外,其余3组构建OIR模型。OIR组除缺氧刺激外,不做其余处理。OIR+LV-Vec组和OIR+LV-PSF组小鼠分别玻璃体腔注射LV-Vec或LV-PSF。观察LV-PSF对视网膜新生血管(RNV)形成的影响。体外实验:将hRMECs分为正常组、缺氧组、空载组、PSF高表达组。正常组为正常体外培养的hRMECs;缺氧组为缺氧刺激3 h恢复正常培养条件24 h的hRMECs;空载组、PSF高表达组分别为用LV-Vec、LV-PSF感染48 h,再用缺氧刺激3 h恢复正常培养条件24 h的hRMECs。采用MTT比色法观察PSF对细胞增生能力的影响。采用细胞划痕实验和Transwell迁移实验观察PSF对缺氧刺激下细胞迁移能力的影响。采用RT-PCR观察各组细胞中HIF-1α、VEGF及PSF的mRNA表达。结果成功构建可稳定高表达PSF的LV-PSF,流式细胞仪测定其感染效率为97%,RT-PCR测得经LV-PSF感染的hRMECs中PSF mRNA水平明显上调。体内实验:OIR组、OIR+LV-Vec组小鼠RNV面积较正常组明显增加(t=18.31、43.71),OIR+LV-PSF组小鼠RNV面积较OIR组(t=11.30)、OIR+LV-Vec组(t=15.47)明显减小,差异均有统计学意义(P<0.05)。体外实验:MTT比色法检测结果显示,缺氧组hRMECs增生能力较正常组明显增强(t=2.57),PSF高表达组hRMECs增生能力较正常组、缺氧组、空载组明显降低(t=5.26、5.46、3.73),差异均有统计学意义(P<0.05)。细胞划痕实验结果显示,缺氧刺激3 h恢复正常条件24 h或48 h均可刺激缺氧组与空载组细胞明显迁移(t=8.35、13.84,P<0.05);而与缺氧组与空载组比较,PSF高表达组细胞迁移不明显(t=10.99、18.27、9.75、8.93、26.94、7.01,P<0.05)。Transwell小室实验结果显示,正常组和空载组微孔膜上染色的细胞数较多,而PSF高表达组微孔膜上染色的细胞数明显减少(t=9.33、6.15,P<0.05)。RT-PCR检测结果显示,与正常组比较,缺氧组、空载组hRMECs中HIF-1α、VEGF的mRNA表达明显增加(t=15.23、21.09,P<0.05),PSF mRNA表达无明显变化(t=0.12、2.15,P<0.05);与缺氧组、空载组比较,PSF高表达组hRMECs中HIF-1α、VEGF的mRNA表达明显下降(t=10.18、13.10,P<0.05),PSF mRNA表达明显增加(t=65.00、85.79,P<0.05)。结论PSF可减少OIR模型小鼠RNV面积。PSF可能通过HIF-1α/VEGF信号通路抑制缺氧诱导的hRMECs增生和迁移。     

Oxidative stress differentially induces tau dissociation from neuronal microtubules in neurites of neurons cultured from different regions of the embryonic Gallus domesticus brain

Abnormal phosphorylation of microtubule-associated proteins such as tau has been shown to play a role in neurodegenerative disorders. It is hypothesized that oxidative stress-induced aggregates of hyperphosphorylated tau could lead to the microtubule network degradation commonly associated with neurodegeneration. We investigated whether oxidative stress induced tau hyperphosphorylation and focused on neurite degradation using cultured neurons isolated from the embryonic chick brain as a model system. Cells were isolated from the cerebrum, cerebellum, and tectum of 14-day-old chicks, grown separately in culture, and treated with tert-Butyl hydroperoxide (to simulate oxidative stress) for 48 hr. Relative expression and localization of tau or phospho-tau and β-tubulin III in neurites were determined using quantitative immunocytochemistry and confocal microscopy. In untreated cells, tau was tightly colocalized with β-tubulin III. Increasing levels of oxidative stress induced an increase in overall tau expression in neurites of cerebral and tectal but not the cerebellar neurons, coupled with a decrease in phospho-tau expression in tectal but not the cerebral or cerebellar neurons. In addition, oxidative stress induced the degeneration of the distal ends of the neurites and redistribution of phospho-tau toward the neuronal soma in the cerebral but not the tectal and cerebellar neurons. These results suggest that oxidative stress induces changes in tau protein that precede cytoskeletal degradation and neurite retraction. Additionally, there is a differential susceptibility of neuronal subpopulations to oxidative stress, which may offer potential avenues for investigation of the cellular mechanisms underlying the differential manifestations of neurodegenerative disorders in different regions of the brain.     

大鼠骨髓间充质干细胞的培养及鉴定

目的:分离培养和鉴定大鼠骨髓间充质干细胞.方法:分离SD青年大鼠股骨,L-DMEM冲洗骨髓腔,制备细胞悬液接种培养,消化传代纯化细胞.传代的骨髓间充质干细胞进行增殖曲线、克隆形成能力测定,用免疫组化检测增殖细胞vimentin、laminin的表达.结果:传代的细胞在培养第1～2天为潜伏期,第3～6天是细胞快速增殖期,第6天达高峰,第 9天后速度减慢,进入平台期,并且随传代次数的增加,细胞增殖速度逐渐下降.随传代次数增多,克隆形成能力逐渐下降.第5代以后细胞基本纯化为骨髓间充质干细胞,细胞呈长梭形.免疫组化检测增殖细胞vimentin表达阳性、laminin表达阴性.结论:本实验方法能有效扩增大鼠骨髓间充质干细胞,而且简单易行.     

IL—1,IL—6,TNF对人TMJ滑膜细胞蛋白合成的影响

目的：研究人ＴＭＪ滑膜细胞（ＳＭＣ）蛋白质合成能力，与其它组织细胞的差异，及细胞因子对这方面的影响。方法：采用体外培养的ＳＭＣ、ＴＧＣ、ＮＭＣ３种细胞及无血清培养液，应用紫外分光光度仪在２８０ｎｍ波长处，对培养上清中的蛋白含量进行测定，并与加用ＩＬ－１、ＩＬ－６、ＴＮＦ后蛋白质合成的量进行对比观察。结果：正常状态下，ＴＧＣ蛋白合成量最高，ＯＤ值达０．１４，而ＳＭＣ最低，为０．０７９。在加用细胞因子作用４８ｈ后，ＳＭＣ蛋白含量达到０．１１７，提高３０％，而ＴＧＣ、ＮＭＣ却下降１０％～３０％。结论：正常状态下ＳＭＣ合成蛋白质成份较其它细胞少，而细胞因子可刺激ＳＭＣ蛋白质合成增加，这些蛋白成份中可能具有影响关节炎症的物质。     

氟对体外培养人牙乳头细胞分泌I型胶原的影响

目的　了解氟对体外培养人牙乳头细胞分泌I型胶原的影响。方法　对人牙乳头细胞体外培养 ,分别给予 0 .0 g/L、0 .2× 10 -6g/L、1.0× 10 6g/L、5 .0× 10 6g/L、2 5 .0× 10 -6g/L氟处理 ,采用Westernblot方法分析氟对细胞培养外I型胶原的影响。结果　体外培养的人牙乳头细胞合成Ⅰ型胶原可以分泌Ⅰ型胶原。 0 .0g/L、0 .2× 10 -6g/L、1.0× 10 6g/L、5 .0× 10 6g/L氟对细胞外Ⅰ型胶原量无显著差异 (P >0 .0 5 ) ;2 5 .0× 10 -6g/L氟处理组细胞外I型胶原量较其它组高 (P <0 .0 5 )。结论　过量氟可能抑制细胞外I型胶原降解     

Mitochondria as a Platform for Dictating the Cell Fate of Cultured Human Corneal Endothelial Cells

PurposeAiming to clarify the role of mitochondria in cell fate decision of cultured human corneal endothelial cell (cHCEC) subpopulations.MethodsThe mitochondrial respiratory ability were examined with Mito stress and Mito fuel flex test assays using an extracellular flux analyzer (XFe24; Agilent Technologies; Santa Clara, CA) for human corneal endothelium tissues, mature cHCECs and a variety of cell state transitioned cHCECs. Tricarboxylic acid cycle and acetyl-coenzyme A–related enzymes was analyzed by proteomics for cell lysates using liquid chromatography–tandem mass spectrometry for cHCEC subpopulations.ResultsThe maximum oxygen consumption rate was found to become stable depending on the maturation of cHCECs. In the Mito stress tests, culture supplements, epidermal growth factor, SB203580, and SB431543 significantly repressed oxygen consumption rate, whereas a Rho-associated protein kinase inhibitor Y-27632 increased. Tricarboxylic acid cycle and mitochondria acetyl-coenzyme A–related enzymes were selectively upregulated in mature cHCECs, but not in cell state transitioned cHCECs. The maximum oxygen consumption rate was found to be higher in healthy human corneal endothelium tissues than those with deeply reduced cell density. An upregulated tricarboxylic acid cycle was linked with metabolic rewiring converting cHCECs to acquire the mitochondria-dependent oxidative phenotype.ConclusionsMitochondrial metabolic intermediates and energy metabolism are tightly linked to the endothelial cell fate and function. These findings will help us to standardize a protocol for endothelial cell injection.     

大鼠胎脑神经细胞与胶原复合体移植对脑损伤的修复

目的:评价胶原蛋白(Collagen)的细胞相容性;研究胶原蛋白(C)与大鼠胎脑神经细胞(FBN)复合体(C-FBN)脑内移植对脑损伤的修复作用。方法:将大鼠FBN与胶原蛋白联合体外培养,进行光镜、扫描电镜观察。并将体外联合培养3～5d的C-FBN(移植前48h培养液中加入BrdU)移植到大脑皮质损伤模型的大鼠脑损伤部位,术后3,6,10,15及30d光镜、BrdU免疫细胞化学染色(ICC)、透射电镜观察脑组织对移植物的反应、移植细胞生长状态及载体在体内的降解情况等。结果:胶原蛋白对FBN生长无不良影响;脑组织对移植物无明显的免疫排斥反应;胶原蛋白与周围脑组织整合好,有血管长入移植物中;载体内有大量存活神经细胞,而且术后各时段都检出BrdU阳性细胞;移植区有突触形成;胶原蛋白海绵吸收、降解快,可诱导组织再生。结论:胶原具有良好的细胞相容性和组织相容性,是神经组织工程的一种较为理想的生物载体材料;生物材料与胎脑神经细胞联合培养移植是治疗脑损伤较有前途的新方法。     

兔骨髓间充质干细胞的体外分离培养、低温冻存及复苏研究

目的寻求体外培养、冻存、复苏兔骨髓间充质十细胞（bone marrow mesenehymal stein cell,BMMSC）的方法,观察体外培养BMMSC的形态及生长特性,研究低温冻存对兔BMMSC生长的影响,为兔BMMSC进一步的实验研究打下基础。方法取新西兰白兔胫骨穿刺获取骨髓液,密度梯度离心法联合贴壁培养法体外纯化扩增,并行液氮冻存3个月。通过倒置显微镜观察其生物学表现,并进行细胞增殖活性分析．绘制生长曲线。结果兔BMMSC为贴壁生长,形态为均匀成纤维细胞样,增殖能力强,传代及冻存后细胞仍然保持其生物学特性。结论兔BMMSC可采取密度梯度离心法联合贴壁培养法进行较好地纯化和扩增,并町长期保存于液氮中,在一定的条件下可复苏存活,冻存不影响细胞的增殖能力。     

Functional mRNA analysis reveals aberrant splicing caused by novel intronic mutation in WDR45 in NBIA patient

WDR45 gene‐associated neurodegeneration with brain iron accumulation (NBIA), referred to as beta‐propeller protein‐associated neurodegeneration (BPAN), is a rare disorder that presents with a very nonspecific clinical phenotype in children constituting global developmental delay. This case report illustrates the power of a combination of trio exome sequencing, in silico splicing analysis, and mRNA analysis to provide sufficient evidence for pathogenicity of a relatively intronic variant in WDR45, and in so doing, find a genetic diagnosis for a 6‐year‐old patient with developmental delay and seizures, a diagnosis which may otherwise have only been found once the characteristic MRI patterns of the disease became more obvious in young adulthood.