In vitro culture and characterization of gene targeted mouse endothelium

Endothelial cells play a crucial role in maintaining cardiovascular homeostasis. Although many cardiovascular disorders involve endothelial cell dysfunction, the specific cellular and molecular mechanisms involved are not well known. We sought to establish a reproducible method of endothelial cell isolation from gene targeted mice to specifically examine endothelial pathophysiological mechanisms. Primary aortic endothelial cell cultures were established from wild type and intercellular adhesion molecule‐1 (ICAM‐1) deficient mice. Isolation of mouse aortic endothelial cells (MAEC) by fluorescent activated cell sorting routinely resulted in pure, homogenous, primary cultures. Wild type and ICAM‐1 deficient endothelial cell morphology was similar, with both cultures showing cobblestone morphology and DiI‐Ac‐LDL staining. Monocyte adhesion to ICAM‐1 deficient aortic endothelial cells was decreased by 86% as compared with wild type MAEC. Monocyte adhesion was also determined using YN‐1, an ICAM‐1 blocking antibody. YN‐1 decreased monocyte adhesion to wild type aortic endothelial cells by 25%, whereas YN‐1 did not further decrease monocyte adhesion to ICAM‐1 deficient MAEC. These data demonstrate that gene targeted endothelial cell cultures are an effective means of identifying specific cellular and molecular mechanisms involved in endothelial cell physiology and dysfunction.     

In vitro culture and characterization of gene targeted mouse endothelium.

Endothelial cells play a crucial role in maintaining cardiovascular homeostasis. Although many cardiovascular disorders involve endothelial cell dysfunction, the specific cellular and molecular mechanisms involved are not well known. We sought to establish a reproducible method of endothelial cell isolation from gene targeted mice to specifically examine endothelial pathophysiological mechanisms. Primary aortic endothelial cell cultures were established from wild type and intercellular adhesion molecule-1 (ICAM-1) deficient mice. Isolation of mouse aortic endothelial cells (MAEC) by fluorescent activated cell sorting routinely resulted in pure, homogenous, primary cultures. Wild type and ICAM-1 deficient endothelial cell morphology was similar, with both cultures showing cobblestone morphology and DiI-Ac-LDL staining. Monocyte adhesion to ICAM-1 deficient aortic endothelial cells was decreased by 86% as compared with wild type MAEC. Monocyte adhesion was also determined using YN-1, an ICAM-1 blocking antibody. YN-1 decreased monocyte adhesion to wild type aortic endothelial cells by 25%, whereas YN-1 did not further decrease monocyte adhesion to ICAM-1 deficient MAEC. These data demonstrate that gene targeted endothelial cell cultures are an effective means of identifying specific cellular and molecular mechanisms involved in endothelial cell physiology and dysfunction.     

In vitro culture of microdissected rat nasal airway tissues.

The surface epithelium lining the nasal airways is a potential target for inhaled contaminants such as ozone, endotoxin, formaldehyde, tobacco smoke, and organic dusts. The epithelial response to injury may depend on the toxicant, the type of epithelium, the severity of the injury, and the presence of inflammatory cells and their secreted products. To study mechanisms of toxicant-induced epithelial injury and repair, in the absence of cellular inflammation or other systemic effects, we have developed a culture system to maintain morphologically distinct nasal airway epithelium in vitro. Microdissected maxilloturbinates and proximal nasal septa of male F344/N rats were cultured at an air-liquid interface for up to 14 d in supplemented serum-free medium. Maxilloturbinates are lined by nonciliated cuboidal nasal transitional epithelium (NTE) with few or no mucous cells. The proximal nasal septum is lined by a mucociliary respiratory epithelium (RE) that normally contains numerous mucous cells. Preservation of the normal RE and NTE phenotype in culture was assessed by light and electron microscopy, and analysis of an airway mucin gene (rMuc-5AC) messenger RNA (mRNA). Both RE and NTE retained normal cell morphology for 14 d in culture (DIC). After 14 DIC there were 20% fewer RE cells in the septa (equal loss of ciliated and mucous cells) and 25% more NTE cells in the maxilloturbinates (increased number of basal cells). Compared with the RE, the NTE expressed consistently low levels of rMuc-5AC mRNA and had little to no histochemically detectable intraepithelial mucosubstances (IM) after 0, 3, 7, or 14 DIC. The amount of stored IM and the steady-state levels of rMuc-5AC mRNA in the RE decreased with time in culture. In summary, this culture system can maintain fully differentiated secretory and nonsecretory rat airway epithelia in vitro for up to 14 d. This study was an essential first step in developing a system to study the pathogenesis of toxicant-induced airway epithelial injury and mechanisms of cellular repair and adaptation in the absence of cellular inflammation and other systemic influences.     

Glucagon-like immunoreactivity in mouse and rat retina

Mouse and rat retinae were examined by the peroxidase-anti-peroxidase technique of immunocytochemistry using an antiserum against glucagon. The immunoreactivity was found in the cells of the ganglion cell layer and inner nuclear layer, including Müller cells. These observations may indicate that glucagon or a similar peptide is important in neuromodulation and/or metabolism of retinal cells.     

In vitro culture of rat neuromicrovascular endothelial cells on polymeric scaffolds

Polyphosphazenes are polymers possessing a skeleton composed of alternating phosphorous and nitrogen atoms, and two side-moieties linked to each phosphorous atom. Polyphosphazenes with amino acid esters as side-moieties are biocompatible and biodegradable polymers. Two polyphosphazenes, poly[bis(ethyl alanate) phosphazene] and poly[(ethyl phenylalanate)0.8(ethyl alanate)0.8(ethyl glycinate)0.4 phosphazene] (PPAGP) were synthesized, and processed to form small fibers. Their ability to support rat neuromicrovascular endothelial cell (EC) adhesion and growth has been studied, using poly(D,L-lactic acid) as reference compound. Scanning electron microscopy revealed that both poly[bis(ethyl alanate) phosphazene] and PPAGP fibers were thinner than poly(D,L-lactic acid) fibers, and possessed a more irregular and porous surface. All polymers increased EC adhesion, compared with polystyrene, but only polyphosphazenes were able to improve EC growth. The highest increase in EC proliferation was induced by PPAGP, which, as revealed by environmental scanning electron microscopy, was also able to induce ECs to arrange into tubular structures. The conclusion is drawn that PPAGP may provide the best scaffold for engineered blood vessels, because it promotes adhesion, growth, and organization of ECs into capillary-like structures.     

四种不同处理方法体外培养大鼠滑膜细胞*☆

背景：常用的原代滑膜细胞培养方法主要是组织块培养法、酶消化法、机械分散法等。 目的：用4种不同方法处理大鼠滑膜组织观察体外培养中滑膜细胞生长情况,探索大鼠膝关节滑膜细胞体外培养的最优方法。 方法：将大鼠滑膜细胞组织块组与剪碎组分别按4种不同的方法处理：①不加消化酶消化。②加Ⅱ型胶原酶消化。③加胰蛋白酶消化。④先加Ⅱ型胶原酶消化、再加胰蛋白酶消化。各组处理后分别进行自然沉壁和人工贴壁培养,利用倒置显微镜观察不同方法下滑膜细胞的生长状况。 结果与结论：培养9 d后,组织剪碎不加消化酶人工贴壁培养的细胞得数为2.03×106,是所有培养方法中细胞的数最多的,细胞活力为95%,细胞活力最强,优于自然贴壁。提示组织的形状、所加入酶的成分以及沉壁的方式均对细胞的生长有重要影响,大鼠膝关节滑膜细胞体外培养的最优方法为组织剪碎不加消化酶人工贴壁培养。     

成骨细胞的体外培养与鉴定

背景：成骨细胞的体外培养方法均存在一定的局限性。 目的：对体外培养成骨细胞的来源,成骨细胞的培养方法及培养条件,鉴定成骨细胞的标志进行总结。 方法：以“Osteoblast, cell culture, identification”为检索词,检索PubMed数据库(2000/2010),以“成骨细胞、细胞培养、鉴定”为检索词,检索万方数据库(2000/2010),文献检索语种限制为英文和中文。纳入与成骨细胞的体外培养及鉴定密切相关的研究,排除重复性研究和Meta分析后对文献进行综述。 结果与结论：随着体外细胞培养技术的发展,人们已经从许多动物的骨、骨膜、骨髓及骨外组织中成功培养了成骨细胞,经鉴定具有典型成骨细胞的特征及良好的生物学特性,目前体外培养成骨细胞为常用的体外实验模型,成为研究骨生理、病理及修复的重要手段,也成为研究成骨细胞生长代谢及骨组织工程的基础。     

In vitro culture on Matrigel favors the long-term maintenance of rat zona glomerulosa-cell differentiated phenotype

Zona glomerulosa (ZG) cells cultured on plastic within few days dedifferentiate losing their capacity to secrete aldosterone (ALDO) in appreciable amounts. Evidence indicates that extracellular matrix modulates the secretory behavior of adrenocortical cells cultured in vitro. Hence, we compared the morphology and function of rat ZG cells grown on plastic and Matrigel basement membrane matrix (hereinafter Matrigel) for up to 12 days. At day 3, no significant differences were observed between cells cultured on plastic and Matrigel. Starting from day 6, ZG cells cultured on plastic lost their ultrastructural differentiated features (mitochondria with tubular cristae, smooth endoplasmic reticulum cisternae and lipid droplets), exhibiting a fibroblast-like appearance. The mRNA expression of the main steroidogenic enzymes, as evaluated by real-time polymerase chain reaction, the baseline secretion of ALDO and other post-pregnenolone hormones, as evaluated by high pressure liquid chromatography, and the secretory response to ACTH, angiotensin-II and K(+), as evaluated by radioimmunoassay, displayed a time-dependent decrease. Matrigel was found to maintain unchanged both the ultrastructure and the expresion of steroidogenic enzymes of ZG cells until day 12 of culture. Baseline and agonist-stimulated steroid-hormone secretion decreased with the duration of culture on Matrigel, but was always higher than that of ZG cells grown on plastic. Hence, our study clearly indicates that the culture on Matrigel favors the maintenance of rat ZG-cell differentiated phenotype, allowing the conclusion that this technique is suitable for long-term in vitro investigations.     

多次胶原酶消化法培养小鼠椎间盘髓核细胞

背景：椎间盘为无血运组织,椎间盘髓核细胞为分化终末细胞,细胞增殖能力较差,体外培养难度较大。 目的：探索小鼠椎间盘髓核细胞体外分离培养的方法。 方法：取小鼠椎间盘髓核组织,使用多次胶原酶消化的方法,分离培养髓核组织细胞,接种,传代,取第2代细胞,分别采用免疫细胞化学和RT-PCR方法检测椎间盘髓核细胞特征性分泌物Ⅱ型胶原和聚合蛋白的分泌量及mRNA的表达,并与软骨细胞,成骨细胞及成纤维细胞进行比较。 结果与结论：椎间盘髓核细胞贴壁后呈现软骨细胞的形态;Ⅱ型胶原和聚合蛋白染色均为阳性;Ⅱ型胶原和聚合蛋白mRNA表达与软骨细胞相同,与成纤维细胞和成骨细胞存在明显差别。说明多次胶原酶消化的方法可以获得大量纯净的椎间盘髓核细胞,性状稳定。     

In vitro spermatogenesis by three-dimensional culture of rat testicular cells in collagen gel matrix

In an effort to improve in vitro spermatogenesis by potentiating the interactions between developing germ cells, somatic cells, and the extracellular matrix (ECM), the efficiency of the germ cell-somatic cell coculture in a three-dimensional (3D) collagen gel matrix was examined. Cells isolated from rat seminiferous tubules 18 days after birth were cultured for 22 days in a monolayer without ECM, collagen gel (CG), or collagen+Matrigel (CGM). After culture, the viabilities of the cultured cells in the monolayer, CG, and CGM culture were 42.8%, 70.7% and 76.1%, respectively. Occludin-positive cells in a cyst-like structure were found in the ECM gel matrix together with 3beta hydroxysteroid dehydrogenase-positive cells, suggesting the presence of functional Sertoli cells and Leydig cells, respectively. Flow cytometric analysis of DNA content revealed a significant increase in the haploid cell population in the CG and CGM compared to the monolayer culture. Transition protein 2 (TP2) and protamine 2-positive cells were found together with a significant increase in TP2 mRNA levels in cells cultured in CG and CGM over those in monolayer culture, suggesting the occurrence of the post-meiotic differentiation of spermatogenetic cells. Taken together, a 3D in vitro culture system for testicular cells using a collagen gel matrix could enhance viability, meiosis, and post-meiotic differentiation of germ cells to presumptive differentiating spermatids.     

新生昆明小鼠胰腺干细胞体外分离、培养及自然分化的潜能**

背景：关于胰腺干细胞在胰腺组织中的分布情况,以及如何有效的将其分离、体外优化培养,目前仍有一定的困难。 目的：从新生昆明小鼠胰腺组织中分离出胰腺干细胞,在体外条件下培养观察其形态学和生物学特征,并进行初步鉴定。 方法：取新生SPF级昆明小鼠的胰腺组织,使用Ⅴ型胶原酶消化,采用Percoll不连续密度梯度离心,使胰腺组织内、外分泌部细胞分离,分布在3个不同的密度界面;收集各界面的细胞,以无血清、添加碱性成纤维细胞生长因子和表皮细胞生长因子的DMEM培养基培养。 结果与结论：通过细胞形态学和细胞生长特性的观察,结合双硫腙染色证实：采用Percoll不连续密度梯度离心,第一、二密度界面的细胞来源于胰腺内分泌部;第三密度界面细胞来源于胰腺外分泌部。分别从胰腺内、外分泌部获取胰腺组织细胞,在体外培养观察发现均存在一类大、圆、单个核的细胞,呈集落样附壁生长,具有较活跃的分裂增殖能力,碱性磷酸酶染色阳性,表达胰腺干细胞的特异性标志巢蛋白,即为胰腺干细胞;随着体外培养时间的延长,分别表达PDX-1和CK-19,呈现向胰腺内分泌部细胞和外分泌部细胞分化的趋势。     

Microencapsulation and culture in vitro of rat pinealocytes

BACKGROUND: Melatonin is a powerful anti-aging reagent for scavenging free radicals. However, the effect of exogenous melatonin on age-dependent diseases is uncertain. Immune rejection has limited xenotransplantation or allotransplantation of the pineal gland. The aim of this study was to assess cell viability and the function of rat pinealocytes encapsulated in APA capsules and offer experimental suggestions for pineal microencapsulation grafting to resist aging. METHODS: The pineal glands of neonatal rats were removed. Pinealocytes were isolated and encapsulated in APA microencapsulation and cultured. Morphological appearance of the microencapsulation was observed. Trypan blue staining and 5-HT immunocytochemical assay were used to detect cell viability and identify pinealocytes. The expression of AA-NAT mRNA was confirmed by RT-PCR. Melatonin release was measured and compared by HPLC. RESULTS: Both control and encapsulated pinealocyte cultures survived well. The majority of the encapsulated pinealocytes as well as unencapsulated cells remained 5-HT positive. No significant difference in melatonin secretion and the expression level of AA-NAT mRNA between encapsulated and unencapsulated pinealocytes was found. CONCLUSIONS: Pinealocytes survive and remain functionally competent in vitro at least 2 weeks after microencapsulation.     

快速诱导大鼠骨髓间充质干细胞成脂分化的培养体系

背景：目前常用的成脂刺激剂主要由胰岛素、地塞米松、IBMX和吲哚美辛组成,该体系涉及处理因素多、诱导周期长且对细胞毒性大,不利于脂肪形成抑制效应的研究。 目的：建立快速诱导大鼠骨髓间充质干细胞成脂分化的培养体系。 方法：大鼠全骨髓细胞原代培养,胰酶消化传代,富集形态均质的间充质干细胞,利用过氧化物酶体增殖物活化受体γ激动剂噻唑烷二酮类药物罗格列酮和吡咯列酮体外单独诱导大鼠骨髓间充质干细胞成脂分化,设立无糖、低糖和高糖DMEM三种基础培养体系,以经典的成脂刺激剂作为阳性对照,在诱导的不同时间点对分化细胞进行形态学观察和油红O染色。 结果与结论：与经典成脂刺激剂相比,罗格列酮或吡咯列酮单独均能诱导大鼠骨髓间充质干细胞向脂肪细胞分化,吡咯列酮诱导48 h和罗格列酮诱导72 h均可观察到富含脂滴或脂泡以及油红O染色的阳性细胞,吡咯列酮与罗格列酮的最佳诱导浓度分别为0.125 mmol/L和10 μmol/L,而高糖环境利于大鼠骨髓间充质干细胞成脂分化。说明基于高糖培养环境的以吡咯列酮或罗格列酮做为成脂刺激剂的培养体系可快速诱导大鼠骨髓间充质干细胞向脂肪细胞分化。     

绿色荧光蛋白转基因小鼠来源肌卫星细胞的体外培养及体内示踪

目的:从绿色荧光蛋白转基因小鼠中分离培养肌卫星细胞(MSCs)并进行体内示踪.方法:利用差速贴壁结合克隆分选方法,分离了MSCs,并于体外进行培养传代、鉴定及分化.检测所获MSCs的生长曲线及细胞周期并与来源于野生型鼠的同代MSCs进行比较.将绿色荧光蛋白标记的MSCs注射到裸鼠胫前肌,于注射后当时、注射后1周、2周、3周和4周利用二维荧光成像平台进行体内示踪.结果:MSCs被成功分离、传代及鉴定.来源于绿色荧光蛋白(GFP)标记或未标记小鼠MSCs的生长曲线、细胞周期及肌原性分化等无差别.MSCs注射后4周内可以动态观察到注射部位的绿色荧光信号并获得组织学证实.结论:来源于GFP转基因小鼠的MSCs在生长和增殖特性上与未转基因来源的MSCs相似,在体内可以通过二维荧光成像平台进行可靠的、无创性的示踪.     

In situ hybridization analysis of substance P receptor in the rat retina

Substance P receptor is known to provide a principal interface between tachykinin peptides and tachykinin-sensitive cells in retinal circuitry and to produce several physiological functions such as excitation of ganglion cells. We reported results of in situ hybridization analysis of substance P receptor in rat retina using digoxigenin-labeled RNA probes to yield discrete cell labeling. Distinct hybridization signal was present in a great majority of ganglion cells that provide retinal fibers to a central target. It was also present in a subpopulation of amacrine cells. Following optic nerve crush, ganglion cells lost their hybridization signal in a time-dependent manner, while hybridization-positive amacrine cells were persistently seen. From the results, we identified the hybridization message as distinctly localized to two systems, output cells and intrinsic cells in retinal circuitry.     

小鼠胚胎体外培养方法的改良

目的改进胚胎培养系统以进一步提高胚胎质量与发育潜能。方法采用内径0.21mm、外径0.28mm的塑料毛细管培养胚胎,将吸有胚胎的毛细管浸在盛有蒸馏水的烧杯内,再将烧杯放置在培养箱里的磁力搅拌器上,允许胚胎在微小的空间内发育并伴随着水的旋转而摆动,更好地模拟了胚胎在输卵管中的运动环境。结果分别对85枚、82枚2-细胞胚胎进行毛细管及微滴培养,其中毛细管培养胚胎的囊胚率以及胚胎细胞数(85.4%,57.0)显著高于微滴培养(36.5%,20.6),囊胚率差异显著(P0.05)。且接种在Matrigel基底膜上形成的内细胞团集落显著增大。结论小鼠胚胎体外培养方法的改良——毛细管培养,促进小鼠植入前胚胎的体外发育。     

In vitro potassium transport in the mouse small intestine

Ingested K+ is believed to be absorbed mainly in the small intestine by passive diffusion through the paracellular pathway. To further clarify K+ absorption in the small intestine, we determined the unidirectional flux values of Rb+ in vitro by atomic absorption spectroscopy in the mouse ileum mounted in Ussing chambers under short-circuit conditions. The mucosal-to-serosal Rb+ flux (J(ms)) was larger than the serosal-to-mucosal Rb+ flux (J(sm)), resulting in positive net Rb+ absorption (J(net)). The effect of changing the transmucosal potential (V(t)) showed that J(ms) was composed of both a V(t)-dependent diffusion component and a V(t)-independent non-diffusion component, while J(sm) was composed mainly of a V(t)-dependent component. A forskolin treatment eliminated J(net) mainly due to the increase in J(sm). When animals were fed a low-Na diet, J(net) was mainly eliminated as a result of the increase in J(sm). These findings suggest that K+ is absorbed not only by passive diffusion through the paracellular pathway, but also by an active transport mechanism operating through the cellular pathway. In addition, cAMP and aldosterone may be involved in regulating intestinal K+ transport.