Systemic inflammation–induced adipose tissue remodeling drives psoriasis exacerbation in obesity through epigenetic and immunometabolic dysregulation

Obesity is a risk factor for psoriasis and negatively influences the severity, treatment responsiveness, and systemic comorbidities of psoriasis. This study aimed to investigate comprehensive inflammatory changes in obesity-associated psoriasis using an obese mouse model of psoriasis induced by topical application of imiquimod or dermal injection of interleukin (IL)-23. Obese mice exhibited aggravated psoriatic dermatitis with pronounced systemic inflammatory responses when exposed to imiquimod. Notably, imiquimod-induced psoriatic dermatitis in obese mice significantly reduced fat mass. Further, pronounced monocyte–macrophage infiltration of perigonadal adipose tissue, increased expression of genes linked to inflammation, and upregulation of cell death-associated molecules were evident in obese mice treated with imiquimod compared with their lean counterparts. In contrast, IL-23 injection could induce similar features of psoriatic inflammation in obese and lean mice, without causing adipose tissue destruction or a systemic increase in inflammatory mediators. Obese adipose tissue of mice with imiquimod-induced psoriatic inflammation features genetic and epigenetic changes in adipocytes and shifts in macrophage compartments toward disturbed homeostasis using multiomic single-nucleus sequencing targeting RNA and accessible chromatin. Therefore, systemic manifestations of psoriasis, coupled with obesity-induced changes in adipose tissue, synergistically exacerbate psoriasis by disrupting the homeostatic microenvironments of adipose tissue.