1-磷酸鞘氨醇促进间充质干细胞向心肌分化

为研究1-磷酸鞘氨醇 (Sphingosine-1-phosphate,S1P) 对脐带间充质干细胞 (Umbilical cord mesenchymal stem cells,UC-MSCs) 和脂肪间充质干细胞 (Adipose derived mesenchymal stem cells,AD-MSCs) 向心肌分化的影响,探索其适宜的作用时间和浓度,将UC-MSCs和AD-MSCs接种到培养板,用添加不同浓度S1P的心肌细胞培养液诱导两种干细胞向心肌分化,诱导时间分为7 d、14 d和28 d。采用免疫荧光染色检测心肌特异性蛋白,α-肌动蛋白 (α-actin)、缝隙连接蛋白 (Connexin-43) 以及肌球蛋白重链 (MYH-6) 的表达,并通过共聚焦显微镜和荧光显微镜进行观察;采用MTT分析细胞的活性;膜片钳检测分化细胞的钙瞬变 (此为心肌细胞的功能性指标)。结果表明,S1P与心肌细胞培养液协同作用,能够促进UC-MSCs和AD-MSCs向心肌细胞的分化。并且,随着S1P浓度的增加,促分化作用增强,但细胞活性降低。S1P在心肌细胞培养液中的适宜作用时间为14 d,适宜作用浓度为0.5 μmol/L。而且联合心肌细胞培养液可以使UC-MSCs和AD-MSCs的心肌分化细胞产生钙瞬变,具有类似心肌细胞的功能性。S1P能够与心肌细胞培养液协同作用,促进UC-MSCs和AD-MSCs的心肌功能性分化。     

人脐带间充质干细胞抑制卵巢癌的初步研究

目的:从足月剖腹产分娩新生儿脐带中分离出人脐带间充质干细胞(UC-MSCs),探讨其在体外促进SKOV3卵巢癌细胞凋亡,抑制其增殖的作用。方法:新鲜人脐带洗净后剥离动静脉及脐带外膜,得到脐带Wharton's胶。采用组织块贴壁法分离、纯化得到UC-MSCs细胞,光镜下观察UC-MSCs细胞的形态及贴壁生长情况。收集UC-MSCs细胞培养上清,加入SKOV3细胞共培养后,观察不同作用时间(12 h,24 h,36 h,48 h,60 h,72 h)其体外促进SKOV3卵巢癌细胞凋亡,抑制其增殖的作用。结果:光镜下UC-MSCs细胞成长梭状,单核,并成放射或漩涡状排列。PI染色提示,随着UC-MSCs细胞培养上清对SKOV3卵巢癌细胞作用时间的增加,其发生凋亡的细胞数量增多,且具有统计学意义(P0.05)。MTT实验提示SKOV3细胞增殖活力随UC-MSCs细胞培养上清作用时间的增加而显著下降(P0.05),共培养24 h,48 h,72 h的抑制率分别为17.08%,35.36%,46.83%。结论:UC-MSCs在体外具有明显促进SKOV3卵巢癌细胞凋亡,抑制其增殖的作用。     

脐带间充质干细胞——组织工程的新视角

目的 从脐带中分离培养脐带间充质干细胞(mesenchymal stem cell, MSC) 并进行鉴定,阐明其多向分化的潜在作用.方法 收集健康胎儿脐带,分离培养脐带中的间充质干细胞,以流式细胞仪对培养的间充质干细胞进行细胞表面标志检测,多种成分联合诱导其向脂肪、成骨方向分化,细胞化学染色检测诱导后的细胞变化.结果 脐带中分离培养的间充质干细胞不表达造血细胞系的标志CD34、CD45、HLA-DR,强表达CD105、CD44、CD90,在适当的诱导条件下可向脂肪及成骨方向分化.结论 脐带中存在具有多向分化潜能的间充质干细胞.     

人脐带间充质干细胞作为维持人胚胎干细胞生长饲养层细胞的研究

目的寻找可以维持人胚胎干细胞未分化生长的人源性细胞作为饲养层细胞,从而解决使用鼠源性细胞作为饲养层带来的安全问题。方法尝试以人脐带间充质干细胞作为饲养层细胞来培养人胚胎干细胞,检验其是否可以维持人胚胎干细胞的未分化生长状态。用胶原酶消化法分离人脐带间充质干细胞,光镜下观察细胞形态;流式细胞仪检测其表面标志;诱导人脐带间充质干细胞向成骨细胞和脂肪细胞进行分化。将人胚胎干细胞系H1接种于丝裂霉素C灭活后的人脐带间充质干细胞上,每隔5d进行一次传代。培养20代后,对人胚胎干细胞特性进行相关检测,包括细胞形态、碱性磷酸酶染色、相关多能性基因的表达、分化能力。结果从人脐带中分离出的间充质干细胞为梭形,呈平行排列生长或漩涡状生长;细胞高表达CD44、CD29、CD73、CD105、CD90、CD86、CD147、CD117,不表达CD14、CD38、CD133、CD34、CD45、HLA-DR;具有分化成脂肪细胞和成骨细胞的潜能。人胚胎干细胞在人脐带间充质干细胞饲养层上培养20代后,继续保持人胚胎干细胞的典型形态,碱性磷酸酶染色为阳性,免疫荧光染色显示OCT4、Nanog、SSEA4、TRA-1-81、TRA-1-60的表达为阳性,SSEA1表达为阴性,体外悬浮培养可以形成拟胚体。结论人脐带间充质干细胞可以作为人胚胎干细胞的饲养层细胞,支持其生长,并维持其未分化生长状态。     

人脐带间充质干细胞在组织工程中的研究进展

人脐带间充质干细胞是一类具有自我更新、增殖和多向分化潜能的干细胞,具有来源广泛、易于采集、保存和运输、无异体排斥、避免伦理争议等诸多优点.流式细胞仪分析发现人脐带间充质干细胞高表达间质细胞标志(CD44、CD105)、整合素受体(CD29、CD49b、CD49c、CD51),不表达造血系标志(CD34、CD45)人白细胞抗原HLA-DR和内皮细胞标志CD31.人脐带间充质干细胞在体内外可以分化为骨细胞、软骨细胞、肝细胞、心肌细胞、骨骼肌细胞以及神经元细胞等.目前人脐带间充质干细胞在组织工程骨、人工血管以及基因治疗等临床应用研究中已逐渐深入,并已显示出广阔的应用前景.本文就人脐带间充质干细胞的生物学特性及其在组织工程中的研究作一综述.     

人脐带间充质干细胞神经向分化与去分化基因表达谱分析

目的用生物信息学方法从公共基因芯片数据库(GEO)中初步筛选出与人脐带间充质干细胞(h UC-MSCs)神经向分化和去分化相关的生物学功能和对应的信号通路,分析蛋白互作关系,为进一步开展h UC-MSCs神经向分化和去分化的实验研究提供指导信息。方法在公共基因芯片数据库GEO中搜寻h UC-MSCs神经向分化与去分化的基因芯片数据,用R和Bioconductor软件包进行统计学分析,筛选差异基因;用Gene Analytics在线分析工具进行GO分析和通路分析;用STRING数据库进行差异表达基因对应的蛋白互作关系分析。结果共筛选得到影响神经向分化和去分化过程的670个上调基因和1 458个下调基因;进一步对这些差异基因进行功能富集分析,发现上调过程的功能集中表现为促血管生成和细胞黏附,下调的生物学过程则主要和代谢相关;上调通路主要有与细胞增殖、分化、凋亡有关的ERK、血管生成和Akt等通路,下调通路主要有与细胞代谢和生物合成相关的萜类化合物骨架生物合成、Cholesterot Biosynthesis II和磷酸肌醇代谢等通路,其中特别的是,维持胚胎干细胞多能性的Nanog通路出现在下调通路中;蛋白互作网络分析发现,与血管生成、细胞黏附相关的蛋白VEGFA、IL-6、FGF2、MMP和IL-8有较高的degree值。结论影响h UC-MSCs神经向分化和去分化的因素很多,其中,促进血管生成、细胞黏附及细胞繁殖相关的基因、生物反应过程、信号通路及相关蛋白起着重要作用。上述基于生物信息学的筛查分析结果为进一步开展h UC-MSCs神经向分化与去分化实验研究提供了一定的参考信息。     

脐带间充质干细胞在糖尿病治疗中的研究进展

糖尿病是一种以高血糖为特征的代谢性疾病,胰岛β细胞功能衰竭和胰岛素抵抗是糖尿病的主要病因。然而,目前的治疗方法,如口服抗糖尿病药物及胰岛素注射,尚不能逆转胰岛β细胞功能衰竭,而胰腺移植又受到供体来源的限制。随着干细胞与再生医学的发展,脐带间充质干细胞(umbilical cord mesenchymal stem cells,UC-MSCs)由于来源丰富、免疫原性低、无伦理问题等,成为治疗糖尿病的理想细胞类型。现就UC-MSCs在糖尿病治疗中的研究进展进行综述,为UC-MSCs移植治疗糖尿病的临床应用研究提供参考。     

脐带间充质干细胞成脂分化的研究

目的:探讨脐带间充质干细胞向成脂细胞方向分化的潜能,为脂肪组织工程提供一种来源丰富的干细胞来源。方法:采用胰酶和胶原酶Ⅰ型联合消化法获得脐带间充质干细胞,通过免疫细胞化学法对其表面标志物进行鉴定,化学诱导方法诱导脐带间充质干细胞向成脂细胞方向分化,倒置显微镜观察其形态变化,油红O染色对诱导后的细胞进行染色。结果:胰酶和胶原酶Ⅰ联合消化法分离的细胞贴壁生长,呈现成纤维细胞形态,免疫细胞化学显示脐带间充质干细胞表达CD29、CD44和CD105,但不表达CD31、CD34和CD105,脐带间充质干细胞在成脂诱导培养基中细胞生长速度明显减慢,细胞形态转变为肥大、扁平、含有大量脂滴的脂肪细胞,油红O染色示胞浆充满了油滴空泡。结论:脐带间充质干细胞具有向成脂细胞方向分化的潜能,为脂肪组织工程提供了一种来源丰富、免疫力低和低分化的种子细胞。     

醋酸铅对脐带间质干细胞生物学特性的影响

探讨醋酸铅对脐带间质干细胞生物学特性的影响。用细胞计数法测定脐带间质干细胞活性,流式细胞仪检测醋酸铅对脐带间质干细胞凋亡的影响,用ALP组织染色分析成骨诱导的变化,并用RT-PCR和定量PCR分析醋酸铅作用前后的细胞因子表达情况。结果显示：脐带间质干细胞活力随醋酸铅浓度的升高而受抑,60μmol/L的醋酸铅可引起脐带间质干细胞凋亡率增加;成骨诱导分化后ALP表达率下降,TPO、SCF和VEGF等细胞因子表达也有所下降。因此,醋酸铅可以抑制脐带间质干细胞的增殖、促进其凋亡并影响其多向分化潜能。     

Nanog、Oct-4、Sox-2基因在3种间充质干细胞中的表达

本研究通过体外传代培养人胎盘(placenta mesenchymal stem cells, PA-MSCs)、脐带(umbilical cord mesenchymal stem cells, UC-MSCs)以及脂肪间充质干细胞(adipose derived mesenchymal stem cells, AD-MSCs),对3种细胞的细胞形态、生长能力、细胞周期及表面标志物进行了检测,同时检测了多能维持基因Nanog、Oct-4和Sox-2的基因表达水平,以探讨其表达量对3种间充质干细胞细胞干性维持能力的影响。结果表明:在3种细胞的传代过程中,PA-MSCs和UC-MSCs的增殖活性明显高于AD-MSCs;随着传代次数的增加,在PAMSCs中,Nanog和Sox-2表达较为稳定,而Oct-4的表达不稳定;在UC-MSCs及AD-MSCs中,3种基因表达水平均表现出较大的差异。因此,研究人员推测PA-MSCs多能性维持能力强于UC-MSCs及AD-MSCs。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418