Characterization of chromatin accessibility in psoriasis

FLI1 Induces Plaque Psoriasis and Its Inhibition Attenuates Disease Progression

Plaque Psoriasis

Plaque psoriasis is an inflammatory skin disorder affecting nearly 2% of the world population. Despite recent advances in psoriasis treatment, there is still a need for more effective therapies. The ETS transcription factor FLI1 plays critical roles in hematopoiesis, angiogenesis, immunity, and cancer. Emerging evidence suggests that FLI1 is intricately involved in inflammatory processes underlying psoriasis pathogenesis.

Methods

RNAseq and bioinformatic analysis were used to identify the correlation between FLI1 levels and the expression of inflammatory genes associated with psoriasis. Over-expression of FLI1 in skin cells determined FLI1's role in inducing transcription of psoriasis-related inflammatory genes, including IL6, IL1A, IL1B, IL23, and TNFα. Inhibitors such as chelerythrine (CLT) were tested for their suppressive effects on these genes. Mouse models of plaque psoriasis were employed to assess the therapeutic potential of CLT and tacrolimus (TAC).

Results

Over-expression of FLI1 in skin cells upregulated 24 psoriasis-associated genes, which were identified through RNAseq. Inhibitors of FLI1, such as CLT, suppressed these inflammatory genes in skin cells. In mouse models of plaque psoriasis induced by imiquimod (IMQ) or phorbol ester (TPA), treatment with the anti-FLI1 inhibitor CLT, administered either peritoneally or topically, significantly downregulated inflammatory genes and alleviated psoriasis symptoms. Similarly, TAC, a common immunosuppressive agent, effectively attenuated IMQ-induced psoriasis by acting as a potent anti-FLI1 compound.

Conclusion

These findings demonstrate that FLI1 plays a central role in psoriasis development and highlight it as a potential therapeutic target for this skin disorder.

Nature vs. nurture: FOXP3, genetics, and tissue environment shape Treg function

The importance of regulatory T cells (Tregs) in preventing autoimmunity has been well established; however, the precise alterations in Treg function in autoimmune individuals and how underlying genetic associations impact the development and function of Tregs is still not well understood. Polygenetic susceptibly is a key driving factor in the development of autoimmunity, and many of the pathways implicated in genetic association studies point to a potential alteration or defect in regulatory T cell function. In this review transcriptomic control of Treg development and function is highlighted with a focus on how these pathways are altered during autoimmunity. In combination, observations from autoimmune mouse models and human patients now provide insights into epigenetic control of Treg function and stability. How tissue microenvironment influences Treg function, lineage stability, and functional plasticity is also explored. In conclusion, the current efficacy and future direction of Treg-based therapies for Type 1 Diabetes and other autoimmune diseases is discussed. In total, this review examines Treg function with focuses on genetic, epigenetic, and environmental mechanisms and how Treg functions are altered within the context of autoimmunity.