目的 ·探究炎症信号通路对 G蛋白偶联受体 C型家族 5A（G protein-coupled receptor class C group 5 member A，GPRC5A）表达的调控作用。方法 ·给予核因子 κB（NF-κB）启动子驱动荧光酶转基因小鼠腹腔注射细菌内毒素脂多糖（ LPS），诱导肺组织炎症，活体动物可见光成像系统下观察小鼠肺部 NF-κB信号通路激活情况。在 C57BL/6J小鼠，腹腔注射 LPS，Western blotting检测肺组织 GPRC5A表达情况。体外实验中，对人肺癌细胞 Calu-1、H322，人胚胎肾细胞 HEK293T给予肿瘤坏死因子 α（TNF-α）或转染 p65表达质粒，而后用 Western blotting、RT-PCR、荧光素酶报告基因实验、免疫荧光等方法检测分析炎症对 GPRC5A表达的影响。结果 ·小鼠腹腔注射 LPS可以诱导 NF-κB炎症信号通路激活，并抑制肺组织中 GPRC5A的表达。炎症因子 TNF-α可明显抑制 Calu-1细胞 GPRC5A的蛋白和 mRNA表达。在 HEK293T细胞，转染 p65表达质粒后，可以抑制 GPRC5A启动子驱动的荧光素酶报告质粒的表达。被转染并表达绿色荧光蛋白 -p65的 H322细胞中几乎没有 GPRC5A的表达。结论 · NF-κB信号通路可以抑制 GPRC5A启动子的转录活性，抑制其 mRNA和蛋白的表达。

Objective · To investigate the regulatory effects of inflammatory signaling pathway on the of G protein-coupled receptor class C group 5 member A (GPRC5A). Methods · Nuclear factor κB (NF-κB)-driven luciferase mice were intraperitoneally injected with lipopolysaccharide (LPS) to evaluate the activation of NF-κB in lungs. GPRC5A in lungs was assessedWestern blotting in the C57BL/6J mice injected with LPS. In vitro tests, human lung tumor cell lines Calu-1 and H322, and human embryonic kidney cell line HEK293T were administered with tumor necrosis factor α (TNF-α) or transfected with p65 plasmid; Western blotting, RT-PCR, luciferase reporter gene experiment and immunofluorescence assay were used to analyze the effect of inflammation on GPRC5A . Results · Intraperitoneal injection of LPS induced activation of NF-κB pathway in lung tissues, which suppressed the of GPRC5A in mice lungs. In Calu-1 cells, TNF-α treatment greatly suppressed the of GPRC5A protein and mRNA. In HEK293T cells, transfection of p65 subunit of NF-κB suppressed the of GPRC5A promoter-driven luciferase reporter. The H322 cells transfected with green fluorescent protein-p65 almost did not express GPRC5A. Conclusion · NF-κB pathway acts at the promoter of GPRC5A and suppresses its mRNA and protein .