Allosteric targeting of the FFA2 receptor (GPR43) restores responsiveness of desensitized human neutrophils.
Allosteric targeting of the FFA2 receptor (GPR43) restores responsiveness of desensitized human neutrophils.
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DOI：
10.1002/jlb.2a0720-432r
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发表时间：
2021-04
影响因子：
5.5
通讯作者：
Grundmann M
中科院分区：
文献类型：
--
作者：
Frei R;Nordlohne J;Hüser U;Hild S;Schmidt J;Eitner F;Grundmann M
G蛋白偶联的游离脂肪酸受体2(FFA2R)在中性粒细胞上高度表达，并被认为调节中性粒细胞的激活。针对G蛋白偶联受体(GPCRs)的变构靶向越来越多地被探索，以创造与内源性正构配体相比独特的药理作用。然而，变构和正构FFA2R激活对中性粒细胞反应的影响目前还很难捉摸。在这里，不同的FFA2R脱敏的人中性粒细胞在变构或正构激活后的报告。通过一系列中性粒细胞功能测定，结合基于动态质量再分配的整体和无偏向全细胞传感，我们发现合成的正性变构调节剂激动剂4-CMTB在同源和异种受体脱敏后，有效地激活了中性粒细胞，同时改变了FFA2R对内源性正构体激动剂丙酸(C3)的反应性。用C3或层级较高的趋化因子受体激活剂IL-8刺激可导致FFA2R强烈脱敏，并使中性粒细胞对C3重复刺激无反应。相反，与正构体受体激活相比，变构4-CMTB的刺激涉及不同的信号通路组成，并能够激活分别与C3和IL-8同源和异源脱敏的中性粒细胞。此外，变构FFA2R的激活可以使FFA2在同源和异源脱敏后对内源性激动剂C3重新增敏。鉴于受体脱敏对中性粒细胞感知和适应当前环境至关重要，这些发现有望有助于发现新的药理机制来调节中性粒细胞的治疗反应。选择性的FFA2受体AGO-PAM 4-CMTB使人中性粒细胞对正构体FFA2的激活重新敏感。
The G protein‐coupled free fatty acid receptor 2 (FFA2R) is highly expressed on neutrophils and was previously described to regulate neutrophil activation. Allosteric targeting of G protein‐coupled receptors (GPCRs) is increasingly explored to create distinct pharmacology compared to endogenous, orthosteric ligands. The consequence of allosteric versus orthosteric FFA2R activation for neutrophil response, however, is currently largely elusive. Here, different FFA2R desensitization profiles in human neutrophils following allosteric or orthosteric activation are reported. Using a set of neutrophil functional assays to measure calcium flux, pERK1/2, chemotaxis, cellular degranulation, and oxidative burst together with holistic and pathway‐unbiased whole cell sensing based on dynamic mass redistribution, it is found that the synthetic positive allosteric modulator agonist 4‐CMTB potently activates neutrophils and simultaneously alters FFA2R responsiveness toward the endogenous, orthosteric agonist propionic acid (C3) after homologous and heterologous receptor desensitization. Stimulation with C3 or the hierarchically superior chemokine receptor activator IL‐8 led to strong FFA2R desensitization and rendered neutrophils unresponsive toward repeated stimulation with C3. In contrast, stimulation with allosteric 4‐CMTB engaged a distinct composition of signaling pathways as compared to orthosteric receptor activation and was able to activate neutrophils that underwent homologous and heterologous desensitization with C3 and IL‐8, respectively. Moreover, allosteric FFA2R activation could re‐sensitize FFA2 toward the endogenous agonist C3 after homologous and heterologous desensitization. Given the fact that receptor desensitization is critical in neutrophils to sense and adapt to their current environment, these findings are expected to be useful for the discovery of novel pharmacological mechanisms to modulate neutrophil responsiveness therapeutically. The selective FFA2 receptor ago‐PAM 4‐CMTB re‐sensitizes human neutrophils toward orthosteric FFA2 activation.