施万细胞条件培养基对大鼠骨髓间质细胞的诱导分化作用

目的　探讨施万细胞条件培养基对大鼠骨髓间质细胞的诱导分化作用。方法　从大鼠骨髓中分离培养间质细胞并传至第 6代 ,诱导前 2 4h加 1μg·L-1碱性成纤维生长因子 (bFGF)入培养液中以促分裂 ,再以施万细胞条件培养基作诱导剂 ,观察细胞形态的变化 ,并采用免疫组织化学法对诱导后一周的细胞进行Map 2及NSE、GFAP表达的检测。结果　诱导后 48小时间质细胞在形态上表现为神经元样 ,神经元样细胞呈Map 2及NSE阳性 ,而GFAP显阴性。结论　施万细胞的上清液能诱导骨髓间质细胞分化为神经元样细胞。     

麻黄碱对支气管平滑肌细胞增殖的影响

在前人工作的基础上,采用一种更简省的方法分离培养支气管平滑肌细胞;并且利用显微镜观察和MTT的方法,研究了麻黄碱对支气管平滑肌细胞形态和增殖的影响.结果表明:麻黄碱对支气管平滑肌细胞的形态没有明显影响,但是对平滑肌细胞的增殖有一定的抑制作用,并进一步阐述了麻黄碱治疗哮喘等呼吸系统疾病的作用机理.     

sGLP-1对Ⅱ型糖尿病大鼠治疗效果的研究

目的 研究人工合成胰高血糖素样截短肽(sGLP-1)对Ⅱ型糖尿病大鼠的治疗效果.方法 Ⅱ型糖尿病GK大鼠随机分为三组,以合成的GLP-1为阳性对照,观察sGLP-1对Ⅱ型糖尿病GK大鼠血糖水平、胰岛素分泌以及糖耐量的影响,通过MTT法测定sGLP-1对胰岛β细胞系β-TC3增殖作用.结果 与GLP-1相比sGLP-1能够长效控制的血糖水平,明显改善糖尿病大鼠的糖耐量(P<0.01).同时sGLP-1能促进胰岛素分泌和胰岛β-TC3细胞的增殖,使得胰岛体积增大,数量增多.结论 sGLP-1控制血糖的长效能力优于GLP-1,可能从刺激胰岛素分泌和促进胰岛β细胞增殖两个方面对Ⅱ型糖尿病具有治疗作用.     

夜香树提取物体外抗肿瘤作用的实验研究

为探讨夜香树(CN)不同提取物体对体外培养的肿瘤细胞的作用,采用系统溶剂法提取CN皂苷和多糖,采用MTT法、细胞集落形成法、生长曲线法观察CN皂苷和多糖对宫颈癌细胞株Hela、人胃癌细胞株SGC7901、人肝癌细胞株Bele7404的生长抑制情况,结果发现CN皂苷和多糖对人胃癌细胞株SGC7901、宫颈癌细胞株Hela、肝癌细胞株Bele7404、等3种肿瘤细胞均有明显的抑制作用:在终浓度为62.5 μg/mL范围,CN皂苷和多糖对上述3种肿瘤细胞的抑制率均大于80%,细胞抑制率均有明显的剂量依赖性,IC50均小于20 μg/mL.CN皂苷和多糖对宫顶癌细胞株Hela、人胃癌细胞株SGC7901、人肝癌细胞株Bele7404细胞有显著的抗增殖作用,其抗增殖作用呈明显的剂量依赖关系.     

纳米氧化铜对大鼠海马神经元Ik和PC12细胞活性的影响

用全细胞膜片钳方法研究纳米氧化铜(nanoCuO)颗粒对大鼠海马CA1区急性分离神经元延迟整流钾通道电流(Ik)的影响,并用MTT方法研究其对神经生长因子(NGF)诱导分化的PC12细胞活性的影响.结果显示5×10-5g/mL nanoCuO能够显著抑制海马CA1区神经元的Ik,使其失活曲线和对照组相比向左偏移,但对其激活过程无明显影响.MTT方法的实验结果显示不同浓度的nanoCuO(5×10-4、5×10-5、5×10-6g/mL)对NGF诱导分化的PC12细胞均有损伤作用,随着浓度的增加,损伤更加明显,呈量效和时效依赖关系.     

斜生褐孔菌多糖诱导人肝癌HepG-2细胞凋亡的研究

研究了斜生褐孔菌多糖对人类肝癌HepG-2细胞凋亡的诱导作用。采用噻唑蓝法(MTT法)观察了斜生褐孔菌多糖对HepG-2细胞生长的影响,用透射电镜观察了细胞形态,用DNA Ladder检测了细胞凋亡,用流式细胞仪检测了细胞凋亡率;同时采用逆转录-聚合酶链反应法(RT-PCR法)研究了不同浓度斜生褐孔菌多糖作用后HepG-2细胞中Bax和Bcl-2基因mRNA转录水平的变化。结果表明斜生褐孔菌多糖能抑制HepG-2细胞增殖,并呈时间剂量依赖关系;电镜观察、DNALadder和流式细胞仪检测均证实了斜生褐孔菌多糖能够诱导HepG-2细胞凋亡;经斜生褐孔菌多糖处理后,HepG-2细胞中Bax基因mRNA转录水平增强,而Bcl-2基因mRNA无明显变化。证明了斜生褐孔菌多糖具有抑制HepG-2细胞生长及诱导HepG-2细胞凋亡的作用,这可能与调节Bcl-2和Bax基因表达水平有关。     

Interleukin 2 induction of antigen-nonspecific suppressor cells

Although Interleukin 2 (IL-2) is essential to the generation of immune responses it may also be important as a regulator of these same responses, as both primary and secondary anti-SRBC responses are greatly diminished when IL-2 is included in culture. IL-2 must be present within the first 24 hr of culture to affect maximum suppression. This inhibition is mediated by suppressor cells which are expanded by pulsing spleen cells with IL-2 for 48-72 hr. Their development is not antigen dependent and their action is antigen nonspecific. Suppressor cell activity can be generated from either naive or primed animals which are equally effective in inhibiting primary or secondary anti-SRBC responses. Suppressor cells can be propagated for long periods of time in T-cell growth factor-containing medium. These long-term cultured cells retain the ability to inhibit various immune responses such as mitogen- and alloantigen-induced proliferation, the generation of cytotoxic T lymphocytes and humoral responses. These cells suppress these responses by absorbing IL-2, as demonstrated by their ability to remove IL-2 upon incubation at 4 degrees C, and the reversal of suppression by the addition of supraoptimal amounts of IL-2.     

Nucleostemin siRNA对肝癌细胞HepG2增殖的影响

Nucleostemin(NS)作为核仁蛋白,在神经干细胞、胚胎干细胞以及某些肿瘤细胞中均高表达,在多种肿瘤细胞增殖和凋亡调控中具有重要作用.本文通过瞬时转染NS siRNA降低NS的表达,以探究NS对HepG2细胞增殖和凋亡的影响.结果显示,下调NS表达使HepG2细胞增殖加快,G₁期细胞减少,S期及G₂/M期细胞增加,凋亡减少. 激光共聚焦实验表明,NS与S期激酶相关蛋白2 (S-phase kinase associated protein 2,Skp2)在HepG2细胞中存在共定位现象; Co-IP实验证明,NS与Skp2能相互作用|NS下调后,Skp2出核仁的数量增加,p27和p53表达降低. 总之,下调NS可促进HepG2细胞中Skp2从核仁逸出,p27降解增强,同时p53表达下降,或由此促进HepG2细胞增殖,抑制其凋亡.     

根皮素对HepG2肝癌细胞增殖和凋亡影响的实验研究

目的：探讨根皮素对人肝癌HepG2细胞增殖和凋亡的影响。方法：MTT法检测不同浓度（30、40、50 ug/mL）根皮素对肝癌 HepG2 细胞增殖的抑制作用,流式细胞技术检测根皮素对HepG2细胞凋亡的影响,ELISA 法检测不同浓度根皮素干预后细胞中 Bcl-2 和Bax表达的变化,Western blot法检测30 ug/mL根皮素在8,16,24 小时后检测p-AKT 蛋白表达情况。结果：30、40 和50 ug/mL 的根皮素对肝癌HepG2 细胞的增殖均有抑制作用（P＜0.01）,同时,30、40 和50 ug/mL 的根皮素在24 小时后可诱导 HepG2 细胞发生早期凋亡,凋亡率分别为0.1321± 0.0224, 0.2607± 0.0457, 0.3712± 0.0884（P＜0.01）;另外,30、40 和50 ug/mL的 根皮素作用24 小时后细胞内Bcl-2 表达降低,Bax 表达增高（P＜0.01）;最后,30 ug/mL根皮素可以明显减少p-AKT 表达量,这 种作用呈现时间依赖性。结论：根皮素能够抑制肝癌HepG2 细胞的增殖和促进细胞凋亡。     

TLR2 stimulation of intrinsic renal cells in the induction of immune-mediated glomerulonephritis

Infection may exacerbate organ-specific autoimmune disease such as glomerulonephritis. This may occur in the absence of a measurable effect on the adaptive immune response, and the mechanisms responsible are not fully understood. To investigate this, we have studied the effect of TLR2 ligation by the synthetic ligand Pam(3)CysSK(4) on the development of glomerulonephritis in mice. We demonstrated that glomerular inflammation induced by passive administration of nephrotoxic Ab does not occur in the absence of TLR2 stimulation, with a strong synergy when Ab deposition and TLR2 stimulation occur together. Parameters of glomerular inflammation were neutrophil influx, thrombosis, and albuminuria. To investigate the relative contribution of TLR2 on bone marrow-derived cells and intrinsic renal cells, we constructed bone marrow chimeras. Nephrotoxic Ab and TLR2 ligation caused a neutrophil influx in both types of chimera above [corrected] that seen in sham chimeras totally TLR2 deficient [corrected] Albuminuria was seen in both types of chimera above that seen in sham chimeras that were totally TLR2 deficient. This was greater in chimeras with TLR2 present on bone marrow-derived cells. To find a potential mechanism by which intrinsic renal cells may contribute toward disease exacerbation, mesangial cells were studied and shown to express TLR2 and MyD88. Wild-type but not TLR2-deficient mesangial cells produced CXC chemokines in response to stimulation with Pam(3)CysSK(4). These results demonstrate that TLR2 stimulation on both bone marrow-derived and resident tissue cells plays a role in amplifying the inflammatory effects of Ab deposition in the glomerulus.     

Proliferation of unilocular fat cells in the primary culture

Mature white fat cells (unilocular fat cells) have generally been considered to be in terminal differentiation and, hence, to have no proliferative ability. A new method, referred to as "ceiling culture," has been devised in our laboratory to culture unilocular fat cells in vitro. Under such culture conditions, the fat cells continue to exhibit specific functions of lipid metabolism and proliferate extensively. Intracytoplasmic lipid droplets did not inhibit division of the cells. There were two modes of proliferation of unilocular fat cells: "loculus-dividing" cell division, in which the single loculus of fat in the dividing cell was broken down into multiple droplets and distributed evenly between the daughter cells, and "loculus-preserving" cell division, in which the loculus in the dividing cell was minimally broken down and inherited with its shape preserved by one of the daughter cells with the other getting only a small number of fine lipid droplets. Such findings suggest that unilocular fat cells in mature fat tissue in vivo are probably capable of proliferation in such modes under some conditions.     

Effect of lectins on induction of apoptosis in the populations of mammalian cells in vitro

The cytotoxic action of lectins different in origin and carboxyl specificity has been studied. It has been shown that all types of lectins at high concentrations (20 mkg/ml) were able to induce apoptosis in the in vitro populations of Chinese hamster cells two days after the treatment. In the case of Persa fluviatilis lectin this effect was detected immediately after the treatment and two days later as well. It was shown that Sambucus nigra lectin did not influence the frequency of apoptosis in the culture of human cells in contrast to the Lens culinaris and P. fluviatilis lectins. The tendency of stimulation of human cell proliferation under exposure to P. fluviatilis lectin at low concentration (0.2 microg/ml) has been registered.     

Presenilin 2 expression in neuronal cells: induction during differentiation of embryonic carcinoma cells

Mutations in the presenilin 1 and 2 (PS1 and PS2) genes cause most cases of early onset Alzheimer's disease. The genes encode two homologous multipass membrane proteins. Since the endogenous expression of PS2 has been poorly analyzed to date, we studied PS2 expression and localization in cultured human neuroblastoma cells and mouse neuronal cells. PS2 was mainly detected as a full-length protein of about 52 kDa in these cells and in brain, in contrast to PS1 that is mainly detected as endoproteolytic N-terminal and C-terminal fragments. Using immunofluorescence we found that like PS1, PS2 colocalized with markers of the endoplasmic reticulum-Golgi intermediate compartment, ERGIC-53 and beta-COP. Double labeling for PS1 and PS2 indicated that both proteins are colocalized in neuroblastoma SH-SY5Y cells. To study PS2 expression during differentiation, mouse embryonic carcinoma P19 cells were treated with retinoic acid. We found minimal PS2 expression in undifferentiated cells, an increase from day 2, and a maximum at day 8 after treatment. PS1 expression remained constant during this period. The differential expression of PS1 and PS2 within the P19 cells following retinoic acid treatment indicates different utilization or temporal requirements for these proteins during neuronal differentiation.