胎鼠中脑多巴胺细胞混合培养方法探索

目的 探索一种新的胚胎大鼠腹侧中脑黑质细胞的混合培养方法,以获得具有高比例多巴胺神经元的原代细胞体系,有利于在体外条件下进行帕金森病(Parkinson's disease,PD)的发病机制和防治的研究.方法 分离E15 (Embryonic Day 15)SD胎鼠中脑黑质区域组织,分散为单细胞后,分别用DMEM/F12+ 10％FBS含血清培养基和Neurobasal+ N1无血清培养基设置不同组别进行培养,通过免疫组织化学方法检测在不同培养条件下细胞的生长状态及多巴胺能神经元的比例.结果 DMEM/F12+ 10％ FBS与Neurobasal+ N1先后一周交替换液的的培养体系中获得的TH阳性神经元占神经元的比例可达31％左右,明显高于单独使用DMEM/F12+ 10％ FBS培养组(约10％).结论 DMEM/F12+ 10％ FBS与Neurobasal +N1先后一周交替换液是一种黑质神经元和胶质细胞混合培养并能获得高比例多巴胺神经元的有效培养方法.     

SD大鼠乳鼠皮层神经元细胞原代培养模型的建立及鉴定

摘要 目的：探讨SD大鼠乳鼠皮层神经元细胞原代培养方法,并鉴定其培养效果,以期建立一种生物学功能良好的体外细胞实验模型。方法：取出生24 h的SD大鼠乳鼠,分离出大脑皮层,在胰酶消化之前先进行离心,然后将胰酶消化后多次离心得到的细胞悬液接种于L-多聚赖氨酸包被的培养皿和共聚焦皿中,以加B27的Neurobasal-A培养基进行神经元细胞的原代培养,倒置显微镜下观察培养细胞的生长状态;通过免疫荧光组化的方法采用神经元标记物MAP-2进行神经元纯度的鉴定;在导入Fluo4-AM的原代神经元细胞,观察电刺激后胞内钙离子信号的变化,以验证神经元细胞的生理状态。结果：采用此方法培养的神经元细胞紧密贴壁、分散均匀、状态良好,神经元细胞周围突起相互连接形成网络;经MAP-2免疫荧光组化技术鉴定神经元的纯度达到95%以上;胞内钙离子信号的变化提示所培养的神经元具有良好的生物学功能。结论：该方法能获得纯度较高并且生物学功能良好的原代培养的SD大鼠乳鼠皮层神经元细胞。     

改良法分离培养SD新生乳鼠原代心肌细胞*

目的:建立一种稳定、快速的SD新生乳鼠原代心肌细胞分离培养改良方法。 方法:取SD新生乳鼠心室,0.12%Ⅱ型胶原酶消化,Percoll密度梯度离心结合5-溴脱氧尿嘧啶(5-BrdU)化学抑制法纯化心肌细胞,体外培养于含5%马血清的改良DMEM/F12中,次日更换为普通含10%胎牛血清的高糖DMEM继续培养,并比较此改良方法与传统差速贴壁法的差异。 结果:改良法获得的心肌细胞生长良好,接种24 h 后几乎全部贴壁生长,细胞呈三角形、梭形或不规则形,个别细胞出现自主搏动,频率为10～30 beats/min不等。48 h后心肌细胞变长伸出伪足,部分细胞呈现同步搏动, 频率接近50～80 beats/min。72 h后心肌细胞成菊花样交织成网,自发搏动趋于同步,频率加快至80～100 beats/min;96 h后细胞聚集成簇,呈岛屿样,同步搏动频率在100～120 beats/min左右,一周内细胞状态良好。改良法纯化原代心肌细胞的得率((1.17±0.15)×10⁶ vs (1.21±0.22)×10⁶,P＞0.05)和存活率与传统差速贴壁法相当(93.3%±1.4% vs 92.2%±0.7%, P＞0.05 ),但是改良方法获得的原代心肌细胞纯度更高 (94.7%±2.1% vs 89.5%±1.3%, P＜0.05),且用时较短((3.1±0.4)h vs (4.3±0.3)h, P＜0.01)。 结论:改良法获得心肌细胞耗时短、纯度高、结构功能保存完整,且实验重复和稳定性好,是一种理想且简单易行的的原代心肌细胞分离培养方法。     

新生SD大鼠皮质神经元的体外培养和鉴定

目的：建立高纯度的新生SD大鼠皮质神经元原代培养方法。方法：取24h内的新生SD大鼠皮质,用木瓜酶和DNaseⅠ共同消化,5％胎牛血清终止消化,吹打分离组织获得单细胞悬液,进行细胞计数,用无血清DMEM／F12种植培养,4h后换成用无血清Neurobasal配制的维持培养液继续培养,尼氏小体染色和免疫荧光法鉴定神经元的纯度。结果：培养第10d,神经元胞体饱满,结构清晰完整,光晕明显,折光性强,可见粗长的树突和轴突,相邻细胞形成紧密网状联系,神经元纯度达到96％以上。结论：经改良和优化,无须添加阿糖胞苷抑制胶质细胞的生长即能够获得生长状态良好、高纯度的神经元。     

阿糖胞苷对大鼠海马神经元原代培养的影响

目的：探讨在大鼠海马神经元原代培养过程中,阿糖胞苷对培养神经元的影响。方法：将新生24 h大鼠,分离出海马组织,进行原代海马神经元培养,再将细胞分为阿糖胞苷组和对照组,阿糖胞苷组加入1μmol/L阿糖胞苷,通过检测神经元特异性标志物微管相关蛋白-2（Map-2）计算培养神经元的数量,通过台盼蓝染色法观察细胞的存活率。结果：培养第7天,阿糖胞苷组神经元数量为（11±3）个,对照组为（10±4）个,两组无明显差异;阿糖胞苷组神经元细胞在培养第14天时存活率为74%,培养第21天时存活率为49%,而对照组神经元14天时存活率为96%,21天存活率为88%,两组神经元存活率差异明显。结论：原代培养海马神经元时,阿糖胞苷对神经元产量及形态影响不明显,但是由于阿糖胞苷的毒性作用,明显缩短神经元的存活时间,影响长期培养神经元的存活率。     

大鼠大脑皮质神经元原代培养不同培养体系及纯化方法的比较研究

目的:比较两种大鼠大脑皮质神经元的培养及纯化方法不同组合的优劣,探讨科学可靠的神经元培养纯化方法。方法:采用DMEM/F12+血清的有血清培养体系和神经基础培养基(Neurobasal)+B27的无血清培养体系培养原代神经元。在接种3天后分别采用加入阿糖胞苷和5-氟脱氧尿嘧啶两种方法进行神经元的纯化。在1天、3天、7天采用形态学及7天时免疫荧光化学法鉴定神经元的纯度及生长状态。结果:1天、3天时,有血清培养体系和无血清体系中的神经元的形态结构和密度无明显差别,在分别加入阿糖胞苷和5-氟脱氧尿嘧啶后,7天时无血清体系中加阿糖胞苷组细胞密度明显低于其他三组细胞密度。通过免疫荧光化学法鉴定可见无血清体系中的神经元纯度明显高于有血清体系。结论:有血清体系的神经元纯度较差,阿糖胞苷和5-氟脱氧尿嘧啶不能显著抑制胶质细胞等杂细胞的生长。无血清培养体系加阿糖胞苷的神经元细胞受损较多,无血清培养体系加5-氟脱氧尿嘧啶纯化培养的大鼠大脑皮质神经元,纯度较高,细胞数量合适,是体外研究神经系统相关理论的良好模型。     

美洲大蠊中枢DUM神经元的分离和电压门控Na+电流的记录

【目的】建立美洲大蠊Periplaneta americana中枢神经系统背侧不成对中间神经元（dorsal unpaired median neurons, DUM neurons）的分离方法和DUM神经元电生理实验模型。【方法】IA型胶原酶法消化美洲大蠊末端腹神经节, 机械吹打得到DUM神经元细胞, 运用膜片钳技术记录DUM神经元细胞电压门控Na+电流。【结果】分离得到的DUM神经元细胞状态良好, 具有DUN神经元典型的梨状形态和表面特征。以膜片钳全细胞方式记录到的Na+电流符合钠通道电流特征。【结论】IA型胶原酶消化得到美洲大蠊DUM神经元细胞的方法可靠, 能稳定地记录到Na+电流。本文描述的方法为昆虫神经细胞的电生理机制研究提供一个可用的实验模型。     

乳鼠成骨细胞体外培养

目的建立乳鼠成骨细胞体外培养方法,探讨该方法的可行性和应用价值。方法用出生1~3 d乳鼠颅骨,采用多次胶原酶消化法进行细胞体外培养。倒置显微镜观察细胞形态,对其碱性磷酸酶(ALP)活性及矿化能力进行鉴定,并测定细胞生长曲线。结果原代培养24 h后,大量细胞贴壁生长,细胞呈圆形,48 h后,贴壁细胞呈长梭形、三角形或不规则多边形,并且贴壁细胞伸出2~3个突起,胞质透亮、饱满,7 d后细胞铺满整个平皿底面。经鉴定,培养细胞具有体内成骨细胞的生物学特性。细胞接种后第1与第2个24 h为细胞的潜伏适应期,第3与第7个24 h生长曲线基本为线性曲线,是细胞的对数生长期。结论采用胶原酶消化法分离培养成骨细胞的方法切实可行。     

小鼠小脑颗粒神经元的原代培养与鉴定

本研究通过体外分离培养及鉴定原代小鼠小脑颗粒神经元(cerebellar granule neurons,CGNs),为神经科学研究提供原代神经元细胞模型。取生后第7天的ICR乳鼠小脑,在解剖体视镜下剥离脑膜及血管,经刀片切碎、0.25%胰酶消化、移液器吹打、70μm尼龙滤网制备单细胞悬液,差速贴壁后接种于新鲜配置的培养基。倒置相差显微镜观察不同时间CGNs的形态变化。采用神经元的标记蛋白微管相关蛋白-2(microtubule associated protein 2,MAP2),星形胶质细胞的标记蛋白胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP),小胶质细胞的标记蛋白(type 3 complement receptor,CR3/CD11b)进行免疫荧光检测培养的原代CGNs纯度。原代培养CGNs接种20 min后即贴壁良好,培养24 h后细胞伸出突起,培养第7天神经元成熟,形成丰富的轴突,树突和胞间突触连接。经免疫荧光鉴定,CGNs纯度可达95%以上。成功体外分离培养出高纯度的原代CGNs,可应用于CGNs的体外研究。     

以支持细胞为饲养层培养小鼠精原干细胞

为探索精原干细胞(Spermatogonialstemcells,SSCs)体外自增殖的条件以及SSCs体外快速扩增的方法,以6-8日龄昆明乳鼠为材料,分离小鼠睾丸细胞,采用Percoll梯度离心法富集SSCs;以经丝裂霉素C处理的Sertoli细胞作饲养层,以DMEM为基本培养基,加入5%胎牛血清和103u/ml的白血病抑制因子(Leukemiainhibitoryfactor,LIF),体外培养SSCs;运用免疫荧光技术,以SSCs特异性表面分子Thy1为标志,对原代培养20d和传代培养14d的细胞进行鉴定。该培养体系下,SSCs贴壁时间为6h-9h,48h后可见细胞分裂,迅速增殖出现在接种12d以后。接种后第20d形成数十至上百个细胞的细胞团,细胞总数比接种时增加了45-245倍,100倍显微镜下观察可见,单位视野内细胞团数为26±4个。传代后细胞增殖较快。原代培养20d和传代培养14d的细胞均为Thy1阳性;而传代20d后,细胞周缘不整,有伪足出现,呈现出死亡迹象。该培养条比较适合SSCs短期快速增殖。     

Characterization of Hair Follicle Development in Engineered Skin Substitutes

Generation of skin appendages in engineered skin substitutes has been limited by lack of trichogenic potency in cultured postnatal cells. To investigate the feasibility and the limitation of hair regeneration, engineered skin substitutes were prepared with chimeric populations of cultured human keratinocytes from neonatal foreskins and cultured murine dermal papilla cells from adult GFP transgenic mice and grafted orthotopically to full-thickness wounds on athymic mice. Non-cultured dissociated neonatal murine-only skin cells, or cultured human-only skin keratinocytes and fibroblasts without dermal papilla cells served as positive and negative controls respectively. In this study, neonatal murine-only skin substitutes formed external hairs and sebaceous glands, chimeric skin substitutes formed pigmented hairs without sebaceous glands, and human-only skin substitutes formed no follicles or glands. Although chimeric hair cannot erupt readily, removal of upper skin layer exposed keratinized hair shafts at the skin surface. Development of incomplete pilosebaceous units in chimeric hair corresponded with upregulation of hair-related genes, LEF1 and WNT10B, and downregulation of a marker of sebaceous glands, Steroyl-CoA desaturase. Transepidermal water loss was normal in all conditions. This study demonstrated that while sebaceous glands may be involved in hair eruption, they are not required for hair development in engineered skin substitutes.     

Cellular events in tolerance. VI. Neonatal vs adult B cell tolerance: differences in antigen-binding cell patterns and lipopolysaccharide stimulation.

The numbers and fate of antigen-binding cells (ABC) in neonatal and adult mice rendered tolerant to fluorescein (FL)-labeled heterologous gamma-globulins were studied. Similar numbers of FL-ABC were observed 1 day after tolerogen in both adult and neonatal mouse spleens: by 7 days after tolerization, no FL-ABC were observed in either case. Reinjection with FL-tolerogen at 7 days led to the detection of normal numbers of ABC in adult mice but significantly reduced numbers in neonates. This suggests that neonatal ABC either have been deleted or have failed to resynthesize surface receptors. Two weeks after tolerance induction, spleen cells from these tolerant mice were cultured with Escherichia coli lipopolysaccharide (LPS), a polyclonal B cell mitogen, or with specific antigen. Tolerant adult spleen cells made an equivalent anti-FL response to that of the uninjected controls when stimulated with LPS, but were unresponsive to specific antigenic triggering. In contrast, spleen cells from neonatally tolerized mice were unresponsive to either specific or nonspecific (LPS) stimulation. Thus, these neonatally tolerized spleen cells lose sensitivity to polyclonal-stimulating agents (along with their receptors), or more simply, are deleted.     

MONOLAYER CULTURES DERIVED FROM NEONATAL HAMSTER PANCREAS : Light and Electron Microscopy

Cells derived by trypsinization of neonatal golden hamster pancreas were cultured in modified Eagle's medium for 120 h in the presence of glucose (0.8 mg/ml) and for an additional 48 h in medium containing glucose (0.8 or 3.1 mg/ml) or tolbutamide (1,000 µg/ml) plus glucose (0.8 mg/ml). At day 7, cultures were stained differentially for light microscopy or examined by electron microscopy. Immunoreactive insulin (IRI) and immunoreactive glucagon (IRG) in the culture medium were measured by standard immunoassay procedures. Staining properties and ultrastructural appearance of cultured cells were comparable to those of the intact neonatal hamster pancreas. Cultures consisted predominantly of cells possessing aldehyde fuchsin positive (AF⁺) cytoplasmic granules resembling ultrastructurally those of the intact neonatal pancreatic beta cells and additionally, those of fibroblastoid, acinar, acino-insular, and aldehyde fuchsin negative (AF^-) argyrophilic cells. IRI release rate by the cultured cells was increased in the presence of elevated glucose or tolbutamide which paralleled the loss of AF⁺ granulation, but IRG release rate was suppressed by elevated glucose concentration. These findings indicate that these monolayer cultures consist of most of the cell types occurring in the neonatal pancreas, including endocrinologically competent islet cells.     

Delayed inflammatory response to Pneumocystis carinii infection in neonatal mice is due to an inadequate lung environment

Challenge of neonatal mice with an intranasal inoculation of Pneumocystis carinii results in a subclinical infection that takes 6 wk to resolve, whereas adult mice resolve a comparable challenge within 3 wk. This delayed clearance is due to a delayed inflammatory response in neonatal mice; however, the reason for this delay has been unknown. To determine whether the neonatal lung environment is sufficient to attract immunocompetent lymphocytes into the lungs, an adoptive transfer strategy was employed in which splenocytes from adult BALB/c mice were transferred into P. carinii-infected neonatal or adult SCID mice. All adults, but no pups, resolved their infections by day 37 postreconstitution. Despite reconstitution with adult splenocytes, pups had a negligible lung inflammatory response until day 24, whereas adult mice had activated CD4(+) and CD8(+) cells in the lung by day 13. The delay in neonates corresponded to delayed kinetics of expression of lung cytokines TNF-alpha and IFN-gamma mRNA and chemokines lymphotactin, RANTES, and macrophage inflammatory protein-1ss mRNA. Phagocytic cells from neonatal mice were significantly less efficient than adult cells at migrating to the draining lymph nodes after phagocytosing fluorescent beads. There were fewer dendritic cells and Ia(+) myeloid cells in the lungs of P. carinii-infected neonatal mice compared with adults. These data indicate that the lung environment of neonatal mice is insufficient for migration of T cells, due at least in part to inefficient phagocytosis and migration of APCs to the lymph nodes as well as delayed chemokine and TNF-alpha mRNA expression.     

Immunohistochemical and autoradiographic findings suggest that minoxidil is not localized in specific cells of vibrissa,pelage, or scalp follicles

Summary Immunohistochemistry with a minoxidil antibody suggested that minoxidil-immunoreactivity is associated with the root sheaths, laterally orientated differentiating matrix cells, and dividing epithelial cells of cultured vibrissa follicles of pigmented and albino neonatal mice. The dermal papilla and connective tissue sheath were devoid of minoxidil-immunoreactivity. To verify that minoxodil-immunoreactivity in the follicles was specific, immunostaining was conducted with dissected whisker pads, formalin-fixed dead follicles, and sections of spleen, liver and kidney (non-haired organs) cultured with minoxidil. Microscopic examination revealed minoxidil-immunoreactivity in all of these tissues. Follicles and whisker pads cultured with minoxidil, then washed for one h in media were devoid of minoxidil-immunoreactivity. These data suggest that minoxidil-immunoreactivity in cultured vibrissa follicles is probably non-specific. Sections of skin from C3H and CF1 mice which were topically dosed with minoxidil (in vivo) phy demonstrated that tritiated minoxidil was bound in vivo and in vitro only to melanin granules in pigmented follicles of rodent and human tissue. This is probably non-specific binding since melanin is known to accumulate several chemically and pharmacologically unrelated drugs. It is reasonable to conclude that, under the conditions of these experiments, minoxidil is not specifically localized in any cells of whisker, pelage or, scalp follicles.     

The suppressive effect of Mekabu fucoidan on an attachment of Cryptosporidium parvum oocysts to the intestinal epithelial cells in neonatal mice

The present study was done to investigate the effects of fucoidan and de-sulfated fucoidan isolated from the sporophyll of Undaria pinnatifida on the C. parvum adhesion to the cultured human intestinal cells and on the C. parvum infection in neonatal mice. The C. parvum adhesion to human Intestinal 407 cells was significantly suppressed by a low dose (1 micro g/ml) of Mekabu fucoidan (1 micro g/ml) (approx. 20.5 oocysts, p<0.0001), but not by de-sulfated fucoidan (approx. 138.2 oocysts), as compared with that (approx. 121.0 oocysts) of phosphate-buffered saline (PBS). The in vivo experiments presented here revealed that C. parvum oocysts in the fucoidan-treated mice was reduced nearly one fifth (approx. 5.4x10(4) oocysts, p<0.02) of the total number of oocysts (approx. 3.0x10(5)) in mice treated with PBS, but no significant effect of de-sulfated fucoidan was observed. These results show that (i) fucoidan effectively inhibits the growth of C. parvum in mice; and (ii) the ester sulfate of fucoidan is an active site to prevent the adhesion of C. parvum to the intestinal epithelial cells. Finally, we concluded that fucoidan might inhibit cryptosporidiosis through the direct binding of fucoidan to the C. parvum-derived functional mediators in the intestinal epithelial cells in neonatal mice.     

Characterization of a continuous lymphocyte cell line derived from BALB/c mice inoculated with a recombinant Moloney murine leukemia virus-TB.

Neonatal BALB/c mice were inoculated (ip) with a recombinant Moloney murine leukemia virus-TB. Majority of the inoculated mice developed lymphoma within 5-7 months post infection. The cells from splenic lymphomas were cultured and 3 continuous cell lines (GP1, GP2 and GP3) developed. GP1 was single cell cloned and characterized. Based on Thy 1.2 (98.4%) phenotypic marker, the cell line was categorized as T cell line. The percent positivity for different cell surface markers on analysis with FACS was 98.4, 4.8, 5.5, 2.2, 1.8, 1.2 and 9.5 for Thy 1.2, mu, L3T4, Lyt2, Ia, IL2R and PNA receptor, respectively. A total of 16.5% GP1 cells was also positive for Moloney murine leukemia virus envelope protein (gp 70). Incomplete retrovirus like particles were demonstrated in the cytoplasm of GP1 cells by electron microscopy. The cell line on inoculation(ip) in neonatal BALB/c mice produced lymphomic lesions in almost all the vital organs of the mice.