INTERACTIONS BETWEEN CEREBROVASCULAR ENDOTHELIAL CELLS AND BLOOD CELLS

中枢神经系统的疾病与改变有关 血脑屏障(BBB)通透性可能与 肾上腺素能输入的干扰。这项研究考察了 黏附分子表达的机制(S) 脑内皮细胞(EC)。其中一种机制是 具有免疫活性的炎性细胞可以进入 大脑通过细胞因子诱导的黏附分子表达 欧共体。最初的项目探索了肾上腺素能药物对 细胞间黏附分子-1的诱导表达 肿瘤坏死因子-α(TNF-α)。体外模型 -lt；95%纯脑微血管内皮细胞来源的系统 来自人脑(HBMEC)。细胞间黏附分子-1在体外培养细胞中的表达 用流式细胞仪检测HBMEC，用ELISA法测定HBMEC； 用放射免疫法测定cAMP含量。HBMEC的单层为 与不同浓度(1-20微米)的异丙肾上腺素孵育 单独或在心得安(10微米)存在的情况下。HBMEC是 孵化30分钟，然后加入10-200U/ml 肿瘤坏死因子-α。早期的时间进程实验显示了 在4-6h，24-48h达到最大表达 剂量依赖性上调HBMEC上ICAM-1的表达。 异丙肾上腺素与异丙肾上腺素联合治疗的剂量依赖性 下调肿瘤坏死因子-α诱导的ICAM-1的表达。 这一观察结果表明，肾上腺素能药物可能参与其中。 ICAM-1在血脑屏障部位的表达。心得安 (A1/A2-肾上腺素能拮抗剂)和丁胺(B2-肾上腺素能 拮抗剂)，但不逆转阿替洛尔(B-肾上腺素能拮抗剂) 异丙肾上腺素的抑制作用。除了……之外 定量表达ICAM-1，我们从以下方面探讨了其机制 异丙肾上腺素对肿瘤坏死因子-α诱导的细胞间黏附分子-1的影响 表情。异丙肾上腺素剂量依赖性刺激cAMP HBMEC制作。CAMP水平升高也出现在 肿瘤坏死因子-α的存在。心得安治疗HBMEC的临床研究 取消了这一效果。这些发现表明， B2-肾上腺素能受体/cAMP通路可能部分参与了 肿瘤坏死因子-α刺激ICAM-1的表达。这些结果支持了 肾上腺素能参与毛细血管功能和血脑屏障完整性。 进一步的研究将检查类似机制的存在 黏附分子在缺氧/缺血中的表达今年5月 更好地了解BBB在 中风等病理情况，可能会产生新的 治疗干预的可能性。

Diseases of the CNS are associated with alterations in blood-brain barrier (BBB) permeability which may be related to disturbances of adrenergic input. This research examined the mechanism(s) involved in the expression of adhesion molecules on brain endothelial cells (EC). One of the mechanisms by which immunologically competent inflammatory cells gain access to the brain is via cytokine-induced expression of adhesion molecules on EC. Initial projects explored the effect of adrenergic agents on the expression of intercellular adhesion molecule-1 (ICAM-1) induced by tumor necrosis factor-alpha (TNF-alpha). The in vitro model system consisted of <95% pure cerebral microvascular EC derived from human brain (HBMEC). ICAM-1 expression on cultured HBMEC was assesed by FACS analysis and quantitated by ELISA; cAMP was assayed by RIA. Monolayers of HBMEC were incubated with various concentrations (1-20 uM) of isoproterenol alone or in the presence of propanolol (10 uM). HBMEC were incubated for 30 min followed by the addition of 10-200 U/ml TNF-alpha. Early time course experiments demonstrated expression at 4-6 h with a maximal expression seen at 24-48 h. TNF-alpha dose-dependently up-regulated ICAM-1 expression on HBMEC. Concomitant treatment with isopreterenol dose-dependently down-regulated the TNF-alpha induced expression of ICAM-1. This observation indicated that adrenergic agents might be involved in ICAM-1 expression at the site of the BBB. Propanolol (a1/a2-adrenergic antagonists) and butoxamine (B2-adrenergic antagonist), but not atenolol (B- adrenergic antagonist) reversed the inhibitory effect induced by isoproterenol. In addition to quantitative ICAM-1 expression, we investigated the mechanism by which isoproterenol modulated the TNF-alpha-induced ICAM-1 expression. Isoproterenol dose-dependently stimulated cAMP production by HBMEC. Elevated levels of cAMP were also seen in the presence of TNF-alpha. Treatment of HBMEC with propanolol abolished this effect. These findings indicated that the B2-adrenergic receptor/cAMP pathway may be partly involved with TNF-alpha-stimulated ICAM-1 expression. The results support the adrenergic involvement in capillary function and BBB integrity. Further studies will examine the existence of similar mechanisms in the expression of adhesion molecules in hypoxia/ischemia. This may provide a better understanding of the involvement of BBB in pathological conditions such as stroke and may yield novel possibilities for therapeutic intervention.