Belleau Joseph T, Gandhi Radha K, McPherson Holly M, Lew D Betty
Department of Pediatrics, Children's Foundation Research Center at the Le Bonheur Children's Medical Center, University of Tennessee Health Science Center, 50 North Dunlap Street, Rm401, WPT, Memphis, TN 38103, USA.
Clin Mol Allergy. 2005 May 20;3:6. doi: 10.1186/1476-7961-3-6.
Airway smooth muscle cells play a key role in remodeling that contributes to airway hyperreactivity. Airway smooth muscle remodeling includes hypertrophy and hyperplasia. It has been previously shown that the expression of CD23 on ASMC in rabbits can be induced by the IgE component of the atopic serum. We examined if other components of atopic serum are capable of inducing CD23 expression independent of IgE.
Serum starved huASMC were stimulated with either IL-4, GM-CSF, IL-13, IL-5, PGD2, LTD4, tryptase or a combination of IL-4, IL-5, IL-13 each with GM-CSF for a period of 24 h. CD23 expression was analyzed by flow cytometry, western blot, and indirect immunofluorescence.
The CD23 protein expression was upregulated in huASMC in response to IL-4, GM-CSF, and IL-4/GM-CSF. The percentage of cells with increased fluorescence intensity above the control was 25.1 +/- 4.2% (IL-4), 15.6 +/- 2.7% (GM-CSF) and 32.9 +/- 13.9% (IL-4/GMCSF combination)(n = 3). The protein content of IL-4/GMCSF stimulated cells was significantly elevated. Expression of CD23 in response to IL-4, GM-CSF, IL-4/GM-CSF was accompanied by changes in cell morphology including depolymerization of isoactin fibers, cell spreading, and membrane ruffling. Western blot revealed abundant expression of the IL-4Ralpha and a low level expression of IL-2Rgammac in huASMC. Stimulation with IL-4 resulted in the phosphorylation of STAT-6 and an increase in the expression of the IL-2Rgammac.
CD23 on huASMC is upregulated by IL-4, GM-CSF, and IL-4/GM-CSF. The expression of CD23 is accompanied by an increase in cell volume and an increase in protein content per cell, suggesting hypertrophy. Upregulation of CD23 by IL-4/GM-CSF results in phenotypic changes in huASMC that could play a role in cell migration or a change in the synthetic function of the cells. Upregulation of CD23 in huASMC by IL-4 and GM-CSF can contribute to changes in huASMC and may provide an avenue for new therapeutic options in asthma targeting ASMC.
气道平滑肌细胞在导致气道高反应性的重塑过程中起关键作用。气道平滑肌重塑包括肥大和增生。先前已表明，特应性血清中的IgE成分可诱导兔气道平滑肌细胞上CD23的表达。我们研究了特应性血清的其他成分是否能够独立于IgE诱导CD23表达。
用IL-4、GM-CSF、IL-13、IL-5、PGD2、LTD4、类胰蛋白酶或IL-4、IL-5、IL-13分别与GM-CSF的组合刺激血清饥饿的人气道平滑肌细胞24小时。通过流式细胞术、蛋白质印迹法和间接免疫荧光分析CD23表达。
人气道平滑肌细胞中CD23蛋白表达因IL-4、GM-CSF和IL-4/GM-CSF而上调。荧光强度高于对照的细胞百分比分别为25.1±4.2%（IL-4）、15.6±2.7%（GM-CSF）和32.9±13.9%（IL-4/GM-CSF组合）（n = 3）。IL-4/GM-CSF刺激的细胞中蛋白质含量显著升高。因IL-4、GM-CSF、IL-4/GM-CSF导致的CD23表达伴随着细胞形态的变化，包括等长肌动蛋白纤维解聚、细胞铺展和膜皱褶。蛋白质印迹显示人气道平滑肌细胞中IL-4Rα表达丰富而IL-2Rγc表达水平低。用IL-4刺激导致STAT-6磷酸化以及IL-2Rγc表达增加。
人气道平滑肌细胞上的CD23因IL-4、GM-CSF和IL-4/GM-CSF而上调。CD23的表达伴随着细胞体积增加和每细胞蛋白质含量增加，提示肥大。IL-4/GM-CSF导致的CD23上调导致人气道平滑肌细胞表型改变，这可能在细胞迁移或细胞合成功能变化中起作用。IL-4和GM-CSF导致的人气道平滑肌细胞中CD23上调可促使其发生变化，并可能为针对气道平滑肌细胞的哮喘新治疗选择提供途径。
