EXPRESSION OF INTERLEUKIN-3 AND TUMOR NECROSIS FACTOR-BETA MESSENGER-RNAS IN CULTURED MICROGLIA
EXPRESSION OF INTERLEUKIN-3 AND TUMOR NECROSIS FACTOR-BETA MESSENGER-RNAS IN CULTURED MICROGLIA
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DOI：
10.1016/0165-5728(95)00057-9
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发表时间：
1995-07-01
影响因子：
3.3
通讯作者：
GEBICKEHAERTER, PJ
中科院分区：
文献类型：
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作者：
APPEL, K;HONEGGER, P;GEBICKEHAERTER, PJ
白细胞介素-3（或多脑脊液）在造血系统中的作用已被详细研究。虽然其对脑小胶质细胞的促生长作用在体外和体内均已得到证实，但其在大脑甚至培养的脑细胞中的存在却一再受到质疑。我们最近发现，离体大鼠小胶质细胞能够表达mRNA（IL-3）并合成IL-3多肽。通过PCR方法显示，mRNA（IL-3）也存在于C6胶质母细胞瘤、大鼠聚集培养物以及新生和成年大鼠大脑中。扩增的cDNA（IL-3）通过非竞争性RT-PCR使用延长的内标进行定量。IL-3信使RNA在体内几乎检测不到，在（无血清）聚集培养中也很低。在分离的小胶质细胞中，mRNA（IL-3）在LPS、PHA、细胞因子IL-1或tnf - α、视黄酸、dbcAMP或酚酯TPA处理后升高。地塞米松抑制LPS的作用，而糖皮质激素本身对基础IL-3表达无影响。脂多糖增加mRNA(IL-3)？以浓度依赖的方式从10pg /ml开始，在10ng /ml达到平台水平。LPS也增加了tnf - α和tnf - β的mrna。在未治疗的小胶质细胞中已经检测到tnf - α mRNA，并且lps水平升高持续了几天。相比之下，tnf - β mRNA仅在LPS孵育4至16小时之间观察到。在不含脂多糖的小胶质细胞中，以及在脂多糖处理24小时或更晚的时间内，它都不存在。tnf - β在小胶质细胞中的表达是一项新发现，为这种细胞类型增加了淋巴细胞的另一个典型特征。由此可见，炎症刺激对培养的小胶质细胞中IL-3和tnf - β的转录率有影响。
The function of interleukin-3 (or multi-CSF) in the hemopoietic system has been studied in great detail. Although its growth promoting activity on brain microglial cells has been confirmed both in vitro and in vivo, its presence in the brain and even in cultured brain cells has repeatedly been questioned. We have shown recently that isolated rat microglia express mRNA(IL-3) and synthesize IL-3 polypeptide. It is shown here by use of the PCR method, that mRNA(IL-3) is found also in C6 glioblastoma, in rat aggregate cultures, and in newborn and adult rat brain. Quantitation of amplified cDNA(IL-3) was achieved by non-competitive RT-PCR using an elongated internal standard. IL-3 messenger RNA was almost undetectable in vivo and low in (serum-free) aggregate cultures. In isolated microglia, mRNA(IL-3) was increased upon treatment with LPS, PHA, with the cytokines IL-1 or TNF-alpha, with retinoic acid, dbcAMP or the phorbol ester TPA. Effects of LPS were inhibited by dexamethasone, while the glucocorticoid by itself had no effect on basal IL-3 expression. LPS increased mRNA(IL-3)? in a concentration-dependent manner beginning with 10 pg/ml and reaching plateau levels at 10 ng/ml. LPS also increased mRNAs of TNF-alpha and TNF-beta. TNF-alpha mRNA was already detectable in untreated microglia and LPS-increased levels were sustained for a few days. In contrast, TNF-beta mRNA was observed only between 4 and 16 h of LPS incubation. It was absent in LPS-free microglia, and after 24 h of LPS-treatment or later. TNF-beta expression in microglia is a new finding and adds another feature typical of lymphocytes to this cell type. It is concluded that transcriptional rates of IL-3 and TNF-beta are influenced by inflammatory stimuli in cultured microglia.