Yamaguchi Atomu, Maeshige Noriaki, Ma Xiaoqi, Uemura Mikiko, Noguchi Hikari, Matsuda Mami, Nishimura Yuya, Hasunuma Tomohisa, Kondo Hiroyo, Fujino Hidemi
Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan.
Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.
J Inflamm Res. 2022 Apr 13;15:2387-2395. doi: 10.2147/JIR.S361609. eCollection 2022.
Itaconate is a key metabolite in the innate immune system and exerts strong anti-inflammatory effects in macrophages. For the production of itaconate in macrophages, immune-responsive gene 1 (IRG1) is an imperative enzyme, and activating the IRG1-itaconate pathway is reported to alleviate inflammatory diseases by upregulating nuclear factor-erythroid 2-related factor 2 (NRF2). However, there are very few reports on strategies to increase itaconate production. Ultrasound therapy is a widely used intervention for anti-inflammatory and soft-tissue regeneration purposes. Here we show the effect of ultrasound irradiation on the production of itaconate in macrophages.
Murine bone marrow-derived macrophages (BMDMs) were exposed to pulsed ultrasound (3.0 W/cm) for 5 minutes. Three hours after irradiation, the intracellular levels of metabolites and mRNA expression levels of and were measured using CE/MS and qPCR, respectively. To evaluate macrophage inflammation status, 3 h after irradiation, the cells were stimulated with 100 ng/mL lipopolysaccharide (LPS) for 1.5 h and the mRNA expression levels of pro-inflammatory factors (, and ) were measured. Student's -test, one-way ANOVA and Tukey's multiple comparison test were used for statistical processing, and the significance level was set to less than 5%.
Ultrasound irradiation significantly increased the intracellular itaconate level and the expression levels of and in BMDMs. Upregulation of , and by LPS was significantly suppressed in BMDMs treated with ultrasound. Ultrasound irradiation did not affect cell viability and apoptosis.
Ultrasound irradiation induces the production of itaconate by upregulating expression and attenuates inflammatory responses in macrophages via . These results suggest that ultrasound is a potentially useful method to increase itaconate production in macrophages.
衣康酸是先天性免疫系统中的关键代谢产物，在巨噬细胞中发挥强大的抗炎作用。对于巨噬细胞中衣康酸的产生，免疫反应基因1（IRG1）是一种必不可少的酶，据报道激活IRG1-衣康酸途径可通过上调核因子红细胞2相关因子2（NRF2）来减轻炎症性疾病。然而，关于增加衣康酸产量的策略的报道非常少。超声治疗是一种广泛用于抗炎和软组织再生目的的干预措施。在此，我们展示了超声照射对巨噬细胞中衣康酸产生的影响。
将小鼠骨髓来源的巨噬细胞（BMDM）暴露于脉冲超声（3.0 W/cm）下5分钟。照射3小时后，分别使用CE/MS和qPCR测量细胞内代谢产物水平和IRG1及NRF2的mRNA表达水平。为了评估巨噬细胞的炎症状态，照射3小时后用100 ng/mL脂多糖（LPS）刺激细胞1.5小时，并测量促炎因子（肿瘤坏死因子α、白细胞介素1β和白细胞介素6）的mRNA表达水平。采用学生t检验、单因素方差分析和Tukey多重比较检验进行统计处理，显著性水平设定为小于5%。
超声照射显著提高了BMDM中细胞内衣康酸水平以及IRG1和NRF2的表达水平。在接受超声治疗的BMDM中，LPS对肿瘤坏死因子α、白细胞介素1β和白细胞介素6的上调作用被显著抑制。超声照射不影响细胞活力和凋亡。
超声照射通过上调IRG1表达诱导衣康酸的产生，并通过NRF2减轻巨噬细胞中的炎症反应。这些结果表明，超声是一种在巨噬细胞中增加衣康酸产量的潜在有用方法。
