NADPH氧化酶(Nox)酶家族的成员是活性氧(ROS)的重要来源,并且已知在响应各种刺激(包括紫外线照射)时参与几种生理功能。UVB诱导的ROS与炎症有关,细胞毒性,细胞死亡,或人类角质形成细胞中的DNA损伤。然而,UVB诱导的ROS的来源和作用尚不明确。这里,我们显示Nox1参与UVB诱导的p38/MAPK激活和通过ROS在角质形成细胞中产生的细胞毒性。Nox1敲低或抑制剂降低了人角质形成细胞中UVB诱导的ROS产生。Nox1敲低受损UVB诱导的p38激活,伴随IL-6水平降低和细胞毒性减弱。用N-乙酰-L-半胱氨酸(NAC)处理细胞,一种有效的ROS清除剂,抑制p38激活以及随后的IL-6产生和细胞毒性,以响应UVB暴露。p38抑制剂还抑制UVB诱导的IL-6产生和细胞毒性。此外,IL-6中和抗体阻断IL-6的产生降低了UVB诱导的细胞毒性。使用野生型小鼠的体内试验,从UVB照射的对照细胞皮内注射裂解物,但不是来自UVB照射的Nox1敲低细胞,在耳朵皮肤中诱导炎症肿胀和IL-6的产生。此外,Nox1抑制剂的施用抑制了UVB诱导的小鼠皮肤中IL-6mRNA表达的增加。总的来说,这些数据表明,Nox1介导的ROS的产生是UVB诱导的细胞毒性和炎症通过p38激活和炎症细胞因子的产生所必需的,例如IL-6。因此,我们的研究结果表明,Nox1可作为UVB暴露引起的细胞毒性和炎症的治疗靶点.
Members of NADPH oxidase (Nox) enzyme family are important sources of reactive oxygen species (ROS) and are known to be involved in several physiological functions in response to various stimuli including UV irradiation. UVB-induced ROS have been associated with inflammation, cytotoxicity, cell death, or DNA damage in human keratinocytes. However, the source and the role of UVB-induced ROS remain undefined. Here, we show that Nox1 is involved in UVB-induced p38/MAPK activation and cytotoxicity via ROS generation in keratinocytes. Nox1 knockdown or inhibitor decreased UVB-induced ROS production in human keratinocytes. Nox1 knockdown impaired UVB-induced p38 activation, accompanied by reduced IL-6 levels and attenuated cell toxicity. Treatment of cells with N-acetyl-L-cysteine (NAC), a potent ROS scavenger, suppressed p38 activation as well as consequent IL-6 production and cytotoxicity in response to UVB exposure. p38 inhibitor also suppressed UVB-induced IL-6 production and cytotoxicity. Furthermore, the blockade of IL-6 production by IL-6 neutralizing antibody reduced UVB-induced cell toxicity. In vivo assay using wild-type mice, the intradermal injection of lysates from UVB-irradiated control cells, but not from UVB-irradiated Nox1 knockdown cells, induced inflammatory swelling and IL-6 production in the skin of ears. Moreover, administration of Nox1 inhibitor suppressed UVB-induced increase in IL-6 mRNA expression in mice skin. Collectively, these data suggest that Nox1-mediated ROS production is required for UVB-induced cytotoxicity and inflammation through p38 activation and inflammatory cytokine production, such as IL-6. Thus, our findings suggest Nox1 as a therapeutic target for cytotoxicity and inflammation in response to UVB exposure.