Involvement of miR-214-3p/FOXM1 Axis During the Progression of Psoriasis

Multi-Omics Approach to Improved Diagnosis and Treatment of Atopic Dermatitis and Psoriasis

Psoriasis and atopic dermatitis fall within the category of cutaneous immune-mediated inflammatory diseases (IMIDs). The prevalence of IMIDs is increasing in industrialized societies, influenced by both environmental changes and a genetic predisposition. However, the exact immune factors driving these chronic, progressive diseases are not fully understood. By using multi-omics techniques in cutaneous IMIDs, it is expected to advance the understanding of skin biology, uncover the underlying mechanisms of skin conditions, and potentially devise precise and personalized approaches to diagnosis and treatment. We provide a narrative review of the current knowledge in genomics, epigenomics, and proteomics of atopic dermatitis and psoriasis. A literature search was performed for articles published until 30 November 2023. Although there is still much to uncover, recent evidence has already provided valuable insights, such as proteomic profiles that permit differentiating psoriasis from mycosis fungoides and β-defensin 2 correlation to PASI and its drop due to secukinumab first injection, among others.

The role of microRNA in psoriasis: A review

Psoriasis is a chronic immune-mediated inflammatory skin disease that involves a complex interplay between infiltrated immune cells and keratinocytes. Great progress has been made in the research on the molecular mechanism of coding and non-coding genes, which has helped in clinical treatment. However, our understanding of this complex disease is far from clear. MicroRNAs (miRNAs) are small non-coding RNA molecules that are involved in post-transcriptional regulation, characterised by their role in mediating gene silencing. Recent studies on miRNAs have revealed their important role in the pathogenesis of psoriasis. We reviewed the current advances in the study of miRNAs in psoriasis; the existing research has found that dysregulated miRNAs in psoriasis notably affect keratinocyte proliferation and/or differentiation processes, as well as inflammation progress. In addition, miRNAs also influence the function of immune cells in psoriasis, including CD4+ T cells, dendritic cells, Langerhans cells and so on. In addition, we discuss possible miRNA-based therapy for psoriasis, such as the topical delivery of exogenous miRNAs, miRNA antagonists and miRNA mimics. Our review highlights the potential role of miRNAs in the pathogenesis of psoriasis, and we expect more research progress with miRNAs in the future, which will help us understand this complex skin disease more accurately.

Genetic and Epigenetic Mechanisms of Psoriasis

Psoriasis is a disease involving the innate and adaptative components of the immune system, and it is triggered by environmental factors in genetically susceptible individuals. However, its physiopathology is not fully understood yet. Recent technological advances, especially in genome and epigenome-wide studies, have provided a better understanding of the genetic and epigenetic mechanisms to determine the physiopathology of psoriasis and facilitate the development of new drugs. This review intends to summarize the current evidence on genetic and epigenetic mechanisms of psoriasis.

Emerging roles of non-coding RNAs in psoriasis pathogenesis

Psoriasis is a complex genetic skin disorder typically manifested by red, scaly, and itchy plaques most commonly over the scalp, trunk, elbows, and knees. Histopathological features include thickening of the epidermal layer due to hyper-proliferation and abnormal differentiation of epidermal keratinocytes along with infiltration of immune cells in the psoriatic skin. It is a chronic inflammatory relapsing disease, and there is currently no permanent cure for psoriasis. Proper medications can reduce the severity of the disease and improve the quality of life of the patients. While the genetic components of psoriasis pathogenesis are well explored, the full understanding of its epigenetic component remains elusive. Non-coding RNAs (ncRNAs) are documented to regulate various epigenetic processes that lead to the pathogenesis of different diseases including psoriasis. In this review, we have discussed the molecular interplay of different ncRNAs in psoriasis pathogenesis. The roles of microRNAs (miRNAs) in psoriasis are pretty well studied, whereas the roles of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are emerging. This review provides ideas covering some of the latest findings of different modes of functions played by those different ncRNAs documented in the literature. As an ever-evolving topic, some works are still ongoing as well as there are several fields that need rigorous scientific ventures. We have proposed the areas which claim more explorations to better understand the roles played by the ncRNAs in psoriasis pathogenesis.

Long Non-Coding RNA-GDA-1 Promotes Keratinocyte Proliferation and Psoriasis Inflammation by Regulating the STAT3/NF-κB Signaling Pathway via Forkhead Box M1

Psoriasis is a chronic inflammatory skin disease associated with multiple comorbidities and complex pathogenesis. Long non-coding RNAs (lncRNAs) play an important regulatory role in many diseases, including psoriasis. In this study, We aimed to investigate the role and mechanism of lncRNA GDA-1 (GDA) in M5-treated psoriatic keratinocytes. GDA expression was significantly upregulated in psoriatic tissues and M5-treated keratinocytes. By silencing and overexpressing GDA in NHEKs and Ker-CT cells, we showed that GDA regulated proliferation and cell cycle and increased secretion of interleukin-1β (IL-1β), IL-6, and chemokine ligands 2 and 20 (CCL2 and CCL20). RNA sequencing after GDA silencing led to the identification of a close regulatory relationship between GDA and Forkhead Box M1 (FOXM1). GDA significantly influenced FOXM1 expression at both mRNA and protein levels and activated STAT3/NF-κB signaling pathways. STAT3 and NF-κB inhibition abrogated GDA effects on keratinocyte proliferation and inflammation. In conclusion, our study is the first to report that Lnc-GDA-1 distinctly regulates FOXM1 expression and mediates proliferation and inflammation of psoriatic keratinocytes through the STAT3/NF-κB signaling pathway, which may be a potent target for psoriasis treatment.

Curcumin Improves Keratinocyte Proliferation, Inflammation, and Oxidative Stress through Mediating the SPAG5/FOXM1 Axis in an In Vitro Model of Actinic Dermatitis by Ultraviolet

Background

Chronic actinic dermatitis (CAD) is an abnormally proliferating photoallergic skin disease. Dysregulated inflammation and oxidative stress are the immediate factors in the abnormal proliferation of keratinocytes. This study aimed to investigate the effect of curcumin on the aberrant proliferation of keratinocytes in an in vitro (actinic dermatitis) AD model and the possible molecular mechanisms.

Methods

The keratinocytes were irradiated with ultraviolet (UV) to construct an in vitro AD model and then processed with different concentrations of curcumin. Cell viability, oxidative stress markers (SOD, GSH-PX, and MDA), activated oxygen species (ROS), and inflammation markers (IL-1β, IL-6, IL-18, and TNFα) were determined, respectively. Western blot was applied to assay the profiles of apoptosis-related proteins (Bax, Bcl-xL, Caspase3, Caspase8, and Caspase9), oxidative stress proteins (Keap1, Nrf2, HO-1, COX2, and iNOS), and inflammatory proteins (NF-κB, MMP1, and MMP9) and SPAG5/FOXM1. Functionally, SPAG5 or FOXM1 overexpression and knockdown models were constructed in keratinocytes to characterize their influence on UV irradiation-mediated keratinocyte dysfunction.

Results

Curcumin weakened UV-mediated inflammation, proliferation, and oxidative stress and impaired apoptosis in keratinocytes. UV boosted SPAG5/FOXM1 expression in cells, while curcumin concentration-dependently retarded SPAG5/FOXM1 expression. Overexpression of SPAG5/FOXM1 fostered UV-mediated inflammation, proliferation, oxidative stress, and intensified apoptosis, whereas curcumin mostly reversed the SPAG5/FOXM1-mediated effects. In addition, knocking down SPAG5/FOXM1 ameliorated UV-mediated keratinocyte dysfunction, whereas curcumin failed to exert further protective effects in cells with knockdown of SPAG5/FOXM1.

Conclusion

Curcumin modulated proliferation, inflammation, oxidative stress, and apoptosis of keratinocytes by restraining the SPAG5/FOXM1 axis.

Contribution of the Environment, Epigenetic Mechanisms and Non-Coding RNAs in Psoriasis

Despite the increasing research and clinical interest in the predisposition of psoriasis, a chronic inflammatory skin disease, the multitude of genetic and environmental factors involved in its pathogenesis remain unclear. This complexity is further exacerbated by the several cell types that are implicated in Psoriasis’s progression, including keratinocytes, melanocytes and various immune cell types. The observed interactions between the genetic substrate and the environment lead to epigenetic alterations that directly or indirectly affect gene expression. Changes in DNA methylation and histone modifications that alter DNA-binding site accessibility, as well as non-coding RNAs implicated in the post-transcriptional regulation, are mechanisms of gene transcriptional activity modification and therefore affect the pathways involved in the pathogenesis of Psoriasis. In this review, we summarize the research conducted on the environmental factors contributing to the disease onset, epigenetic modifications and non-coding RNAs exhibiting deregulation in Psoriasis, and we further categorize them based on the under-study cell types. We also assess the recent literature considering therapeutic applications targeting molecules that compromise the epigenome, as a way to suppress the inflammatory cutaneous cascade.

Anti-Inflammatory microRNAs for Treating Inflammatory Skin Diseases

Skin inflammation occurs due to immune dysregulation because of internal disorders, infections, and allergic reactions. The inflammation of the skin is a major sign of chronic autoimmune inflammatory diseases, such as psoriasis, atopic dermatitis (AD), and lupus erythematosus. Although there are many therapies for treating these cutaneous inflammation diseases, their recurrence rates are high due to incomplete resolution. MicroRNA (miRNA) plays a critical role in skin inflammation by regulating the expression of protein-coding genes at the posttranscriptional level during pathogenesis and homeostasis maintenance. Some miRNAs possess anti-inflammatory features, which are beneficial for mitigating the inflammatory response. miRNAs that are reduced in inflammatory skin diseases can be supplied transiently using miRNA mimics and agomir. miRNA-based therapies that can target multiple genes in a given pathway are potential candidates for the treatment of skin inflammation. This review article offers an overview of the function of miRNA in skin inflammation regulation, with a focus on psoriasis, AD, and cutaneous wounds. Some bioactive molecules can target and modulate miRNAs to achieve the objective of inflammation suppression. This review also reports the anti-inflammatory efficacy of these molecules through modulating miRNA expression. The main limitations of miRNA-based therapies are rapid biodegradation and poor skin and cell penetration. Consideration was given to improving these drawbacks using the approaches of cell-penetrating peptides (CPPs), nanocarriers, exosomes, and low-frequency ultrasound. A formulation design for successful miRNA delivery into skin and target cells is also described in this review. The possible use of miRNAs as biomarkers and therapeutic modalities could open a novel opportunity for the diagnosis and treatment of inflammation-associated skin diseases.