Department of Chemical Defense Medicine, School of Military Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing, China.
Institute of Toxicology, School of Military Preventive Medicine, Third Military Medical University (Army Medical University), Chongqing, China.
Clin Transl Med. 2021 Feb;11(2):e312. doi: 10.1002/ctm2.312.
Nitrogen mustard (NM) causes severe skin injury with an obvious inflammatory response, which is lack of effective and targeted therapies. Vitamin D3 (VD3) has excellent anti-inflammatory properties and is considered as a potential candidate for the treatment of NM-induced dermal toxicity; however, the underlying mechanisms are currently unclear. Cyclooxygenase-2 (COX2; a widely used marker of skin inflammation) plays a key role in NM-induced cutaneous inflammation. Herein, we initially confirmed that NM markedly promoted COX2 expression in vitro and in vivo. NM also increased NOD-like receptor family pyrin domain containing 3 (NLRP3) expression, caspase-1 activity, and interleukin-1β (IL-1β) release. Notably, treatment with a caspase-1 inhibitor (zYVAD-fmk), NLRP3 inhibitor (MCC950), and NLRP3 or caspase-1 siRNA attenuated NM-induced NLRP3 inflammasome activation, with subsequent suppression of COX2 expression and IL-1β release in keratinocytes. Meanwhile, NM increased mitochondrial reactive oxygen species (mtROS) and decreased manganese superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) activities. Mito-TEMPO (a mtROS scavenger) ameliorated NM-caused NLRP3 inflammasome activation in keratinocytes. Moreover, VD3 improved SIRT3 and SOD2 activities, decreased mtROS contents, inactivated the NLRP3 inflammasome, and attenuated cutaneous inflammation induced by NM in vitro and in vivo. The beneficial activity of VD3 against NM-triggered cutaneous inflammation was enhanced by the inhibitors of IL-1, mtROS, NLRP3, caspase-1, and NLRP3 or caspase-1 siRNAs, which was abolished in SIRT3 inhibitor or SIRT3 siRNA-treated keratinocytes and skins from SIRT3 mice. In conclusion, VD3 ameliorated NM-induced cutaneous inflammation by inactivating the NLRP3 inflammasome, which was partially mediated through the SIRT3-SOD2-mtROS signaling pathway.
氮芥（NM）可导致严重的皮肤损伤，并伴有明显的炎症反应，而目前针对这种皮肤损伤缺乏有效且有针对性的治疗方法。维生素 D3（VD3）具有出色的抗炎特性，被认为是治疗 NM 诱导的皮肤毒性的潜在候选药物；然而，其作用机制目前尚不清楚。环氧化酶-2（COX2；一种广泛用于标记皮肤炎症的标志物）在 NM 诱导的皮肤炎症中起着关键作用。在此，我们首先证实 NM 可显著促进体外和体内 COX2 的表达。NM 还增加了 NOD 样受体家族含 pyrin 结构域蛋白 3（NLRP3）的表达、半胱天冬酶-1 的活性和白细胞介素-1β（IL-1β）的释放。值得注意的是，用半胱天冬酶-1 抑制剂（zYVAD-fmk）、NLRP3 抑制剂（MCC950）、NLRP3 或半胱天冬酶-1 siRNA 处理可减弱 NM 诱导的 NLRP3 炎性小体激活，随后抑制角质形成细胞中 COX2 的表达和 IL-1β 的释放。同时，NM 增加了线粒体活性氧（mtROS）的含量，降低了锰超氧化物歧化酶 2（SOD2）和沉默信息调节因子 3（SIRT3）的活性。线粒体 TEMPO（mtROS 清除剂）改善了 NM 引起的角质形成细胞中 NLRP3 炎性小体的激活。此外，VD3 提高了 SIRT3 和 SOD2 的活性，降低了 mtROS 的含量，使 NLRP3 炎性小体失活，并减轻了 NM 对体外和体内皮肤炎症的影响。通过抑制白细胞介素 1、mtROS、NLRP3、半胱天冬酶-1、NLRP3 或半胱天冬酶-1 siRNA，VD3 对 NM 触发的皮肤炎症的有益作用得到了增强，而在 SIRT3 抑制剂或 SIRT3 siRNA 处理的角质形成细胞和 SIRT3 小鼠的皮肤中，这种作用被消除。总之，VD3 通过使 NLRP3 炎性小体失活来改善 NM 诱导的皮肤炎症，而这部分是通过 SIRT3-SOD2-mtROS 信号通路介导的。
