Biochemical Technologies, Science and Technology Division, Corning Inc., Corning, New York, United States of America.
PLoS One. 2011 Apr 26;6(4):e19282. doi: 10.1371/journal.pone.0019282.
The β(2)-adrenergic receptor (β(2)AR) agonists with reduced tachyphylaxis may offer new therapeutic agents with improved tolerance profile. However, receptor desensitization assays are often inferred at the single signaling molecule level, thus ligand-directed desensitization is poorly understood. Here we report a label-free biosensor whole cell assay with microfluidics to determine ligand-directed desensitization of the β(2)AR. Together with mechanistic deconvolution using small molecule inhibitors, the receptor desensitization and resensitization patterns under the short-term agonist exposure manifested the long-acting agonism of salmeterol, and differentiated the mechanisms of agonist-directed desensitization between a full agonist epinephrine and a partial agonist pindolol. This study reveals the cellular mechanisms of agonist-selective β(2)AR desensitization at the whole cell level.
β(2)-肾上腺素能受体 (β(2)AR) 激动剂具有较低的快速脱敏作用，可能提供具有改善耐受性特征的新型治疗药物。然而，受体脱敏测定通常在单个信号分子水平上推断，因此配体定向脱敏作用尚不清楚。在这里，我们报告了一种无标记的生物传感器全细胞测定法，该测定法与微流控技术相结合，可确定β(2)AR 的配体定向脱敏作用。通过使用小分子抑制剂进行机制分解，在短期激动剂暴露下，受体脱敏和再敏化模式表现出沙美特罗的长效激动作用，并区分了完全激动剂肾上腺素和部分激动剂吲哚洛尔之间激动剂定向脱敏的机制。这项研究揭示了在全细胞水平上激动剂选择性β(2)AR 脱敏的细胞机制。
