Serum Levels of Aryl Hydrocarbon Receptor, Cytochromes P450 1A1 and 1B1 in Patients with Exacerbated Psoriasis Vulgaris

Bergapten Ameliorates Psoriatic Skin Lesions and IL-17A-Induced Activation of the NF-κB Signaling Pathway via the Downregulation of CYP1B1

Bergapten (BP) is a plant-derived furocoumarin that has a wide range of pharmacological effects. BP serves as a candidate amplifier in phototherapy against skin inflammation, such as psoriasis and atopic dermatitis. However, the anti-inflammatory role of BP remains elusive. We utilized IL-17A-stimulated keratinocyte line and imiquimod-challenged BALB/c mice to imitate psoriasis-like inflammation. Inflammatory phenotypes were determined by expressions of inflammatory genes and cytokines, histopathological changes and activities of nuclear factor-κB (NF-κB) pathway. An RNA-seq analysis of rodent skin was performed to explore possible mechanism lying behind. SiRNAs and antagonist (TMS) against cytochrome P450 family 1 subfamily B member 1 (CYP1B1) were subsequently used to determine the role of CYP1B1 in psoriasis pathogenesis in vitro and in vivo. Overexpression of CYP1B1 with lentivirus further validate therapeutic effect of BP. BP significantly suppressed activation of the NF-κB pathway by inhibiting p65 phosphorylation and improved the inflammatory phenotype both in vitro and in vivo. We revealed the key role of CYP1B1 in regulating the activation of the NF-κB signaling pathway. Knock-down with siRNAs significantly reduce the expression of inflammatory genes and cytokines. An intraperitoneal injection of TMS partially remediated IMQ-induced inflammation, mainly in terms of skin thickness. Overexpression of Cyp1b1 led to increased expression of the CYP1B1 protein and rescued the therapeutic effect of BP in vitro. This study revealed that BP suppressed expression of Cyp1b1 in keratinocytes and inhibited the activation of NF-κB signaling pathway by blocking the phosphorylation of p65.

The Role of Aryl Hydrocarbon Receptor in the Pathogenesis and Treatment of Psoriasis

The pathogenesis of psoriasis is complex. Aryl hydrocarbon receptor (AhR) is a transcription factor that can be bound and activated by structurally diverse ligands and plays an important role in a range of biological processes and in the pathogenesis of different diseases. Recently, the role of AhR in psoriasis has attracted attention. AhR has toxicological functions and physiological functions. The overexpression and activation of AhR induced by the environmental pollutant and exogenous AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can drive the development of psoriasis. This TCDD-mediated toxicological response disrupts the physiological functions of AhR resulting in skin barrier disorders and the release of inflammatory cytokines, 2 of the pivotal factors of psoriasis. In addition, highly upregulated kynureninase in psoriasis decreases endogenous AhR agonists, thereby weakening the physiological functions of AhR. Activating AhR physiological signalling should be useful in the treatment of psoriasis. Studies have demonstrated that physiological activation of AhR can dampen the severity of psoriasis. The oldest and effective treatment for psoriasis coal tar works by activating AhR, and both new anti-psoriasis drugs tapinarof and benvitimod are formulations of AhR agonist, supporting that activation of AhR can be used as a new strategy for the treatment of psoriasis. Preclinical and preliminary clinical studies have revealed the anti-psoriasis effects of a number of AhR agonists, providing potential candidates for the development of new drugs for the treatment of psoriasis.