背景:角质形成细胞的Ferropating与银屑病皮肤炎症的放大密切相关。这项研究的重点是解锁咖啡酸(CA)的作用,多酚化合物,在角质形成细胞铁性凋亡和理解潜在的机制基础。
方法:通过生物信息学预测早期生长反应蛋白1(EGR1)和chac谷胱甘肽特异性γ-谷氨酰环基转移酶1(CHAC1)之间的相互作用,并通过染色质免疫沉淀和双荧光素酶报道的测定进行验证。通过转染EGR1/CHAC1过表达或敲低质粒,改变了它们在人表皮角质形成细胞中的表达,然后对角质形成细胞进行CA处理和Erastin(铁凋亡诱导物)。通过CCK-8测定确定角质形成细胞的活力,并使用比色法和流式细胞术评估铁的作用。通过ELISA检测角质形成细胞的促炎细胞因子分泌。通过qRT-PCR或Westernblot分析角质形成细胞中EGR1和CHAC1的表达。
结果:在用Erastin处理的角质形成细胞中检测到EGR1和CHAC1的表达增加。CA(100μM)拮抗Erastin(10μM)诱导的活力降低,EGR1和CHAC1表达式增加,MDA的上调,ROS,和Fe2+,GSH和SOD的下调,和从角质形成细胞分泌促炎细胞因子。EGR1过表达增强了Erastin诱导的作用。此外,EGR1过表达和CA相互抵消了它们对Erastin诱导的角质形成细胞的影响。EGR1转录激活并正调节CHAC1。上述Erastin诱导的作用被EGR1敲低中和,但被CHAC1过表达增强。此外,EGR1敲低和CHAC1过表达可逆转彼此的作用。
结论:CA通过抑制EGR1诱导的CHAC1活化来减轻银屑病中角质形成细胞的炎症,从而降低了铁凋亡。本研究为银屑病的临床治疗提供了新的化合物和候选靶点。
BACKGROUND: Ferroptosis of keratinocytes is closely associated with amplification of skin inflammation in psoriasis. This study focuses on unlocking the role of caffeic acid (CA), a polyphenol compound, in keratinocyte ferroptosis and understanding the underlying mechanistic basis.
METHODS: The interaction between early growth response protein 1 (EGR1) and chac glutathione specific γ‑glutamylcyclotransferase 1 (CHAC1) was predicted by bioinformatics and validated via chromatin immunoprecipitation and dual-luciferase reported assays. Their expressions in primary human epidermal keratinocytes were altered by transfection of EGR1/CHAC1 overexpression or knockdown plasmids, and then keratinocytes were followed by CA treatment and Erastin (ferroptosis inducer). Keratinocyte viability was determined by CCK-8 assay, and the ferroptotic effect was evaluated using colorimetric assay and flow cytometry. Proinflammatory cytokine secretion by keratinocytes was detected via ELISA. Expressions of EGR1 and CHAC1 in keratinocytes were analyzed by qRT-PCR or Western blot.
RESULTS: Increased expressions of EGR1 and CHAC1 were detected in keratinocytes with Erastin treatment. CA (100 μM) antagonized Erastin (10 μM)-induced decrease in viability, increases in EGR1 and CHAC1 expressions, upregulation of MDA, ROS, and Fe2+, downregulation of GSH and SOD, and secretion of proinflammatory cytokines from keratinocytes. EGR1 overexpression potentiated Erastin-induced effects. Moreover, EGR1 overexpression and CA mutually counteracted their effects on Erastin-induced keratinocytes. EGR1 transcriptionally activated and positively regulated CHAC1. The above Erastin-induced effects were neutralized by EGR1 knockdown but potentiated by CHAC1 overexpression. Moreover, EGR1 knockdown and CHAC1 overexpression reversed each other\'s effects.
CONCLUSIONS: CA reduces ferroptosis by inhibiting EGR1-induced activation of CHAC1 to dampen inflammation of keratinocytes in psoriasis. This study providing new compounds and candidate targets for the clinical treatment of psoriasis.