Insightful exploring of microRNAs in psoriasis and its targeted topical delivery

Upregulated miR-374a-5p drives psoriasis pathogenesis through WIF1 downregulation and Wnt5a/NF-κB activation

BACKGROUND

Psoriasis is a chronic, inflammatory skin disease. MicroRNAs (miRNAs) are an abundant class of non-coding RNA molecules. Recent studies have shown that multiple miRNAs are abnormally expressed in patients with psoriasis. The upregulation of miR-374a-5p has been associated with psoriasis severity. However, the specific role of miR-374a-5p in the pathogenesis of psoriasis remain unclear.

METHODS

qRT-PCR was employed to validate the expression of miR-374a-5p in psoriatic lesions and in a psoriasis-like cell model constructed using a mixture of M5 (IL-17A, IL-22, OSM, IL-1α, and TNF-α). HaCaT cells were transfected with miR-374a-5p mimic/inhibitor, and assays including EdU, CCK-8, and flow cytometry were conducted to evaluate the effect of miR-374a-5p on cell proliferation. The expression of inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α was verified by qRT-PCR. Bioinformatics analysis and dual-luciferase reporter gene assay were performed to detect the downstream target genes and upstream transcription factors of miR-374a-5p, followed by validation of their expression through qRT-PCR and Western blotting. A psoriasis-like mouse model was established using imiquimod cream topical application. The psoriasis area and severity index scoring, hematoxylin-eosin histology staining, and Ki67 immunohistochemistry were employed to validate the effect of miR-374a-5p on the psoriatic inflammation phenotype after intradermal injection of miR-374a-5p agomir/NC. Additionally, the expression of pathway-related molecules and inflammatory factors such as IL-1β, IL-17a, and TNF-α was verified by immunohistochemistry.

RESULTS

Upregulation of miR-374a-5p was observed in psoriatic lesions and the psoriasis-like cell model. In vitro experiments demonstrated that miR-374a-5p not only promoted the proliferation of HaCaT cells but also upregulated the expression of inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α. Furthermore, miR-374a-5p promoted skin inflammation and epidermal thickening in the Imiquimod-induced psoriasis-like mouse model. Mechanistic studies revealed that miR-374a-5p led to downregulation of WIF1, thereby activating the Wnt5a/NF-κB signaling pathway. The transcription factor p65 encoded by RELA, as a subunit of NF-κB, further upregulated the expression of miR-374a-5p upon activation. This positive feedback loop promoted keratinocyte proliferation and abnormal inflammation, thereby facilitating the development of psoriasis.

CONCLUSION

Our findings elucidate the role of miR-374a-5p upregulation in the pathogenesis of psoriasis through inhibition of WIF1 and activation of the Wnt5a/NF-κB pathway, providing new potential therapeutic targets for psoriasis.

Topical Delivery of microRNA-125b by Framework Nucleic Acids for Psoriasis Treatment

Purpose

Psoriasis is a chronic and recurrent inflammatory dermatitis characterized by T cell imbalance and abnormal keratinocyte proliferation. MicroRNAs (miRNAs) hold promise as therapeutic agents for this disease; however, their clinical application is hindered by poor stability and limited skin penetration. This study demonstrates the utilization of Framework Nucleic Acid (FNA) for the topical delivery of miRNAs in psoriasis treatment.

Methods

By utilizing miRNA-125b as the model drug, FNA-miR-125b was synthesized via self-assembly. The successful synthesis and stability of FNA-miR-125b in bovine fetal serum (FBS) were verified through gel electrophoresis. Subsequently, flow cytometry was employed to investigate the cell internalization on HaCaT cells, while qPCR determined the effects of FNA-miR-125b on cellular functions. Additionally, the skin penetration ability of FNA-miR-125b was assessed. Finally, a topical administration study involving FNA-miR-125b cream on imiquimod (IMQ)-induced psoriasis mice was conducted to evaluate its therapeutic efficacy.

Results

The FNA-miR-125b exhibited excellent stability, efficient cellular internalization, and potent inhibition of keratinocyte proliferation. In the psoriasis mouse model, FNA-miR-125b effectively penetrated the skin tissue, resulting in reduced epidermal thickness and PASI score, as well as decreased levels of inflammatory cytokines.

New and Emerging Oral/Topical Small-Molecule Treatments for Psoriasis

The introduction of biologic therapies has led to dramatic improvements in the management of moderate-to-severe psoriasis. Even though the efficacy and safety of the newer biologic agents are difficult to match, oral administration is considered an important advantage by many patients. Current research is focused on the development of oral therapies with improved efficacy and safety compared with available alternatives, as exemplified by deucravacitinib, the first oral allosteric Tyk2 inhibitor approved for the treatment of moderate to severe psoriasis in adults. Recent advances in our knowledge of psoriasis pathogenesis have also led to the development of targeted topical molecules, mostly focused on intracellular signaling pathways such as AhR, PDE-4, and Jak-STAT. Tapinarof (an AhR modulator) and roflumilast (a PDE-4 inhibitor) have exhibited favorable efficacy and safety outcomes and have been approved by the FDA for the topical treatment of plaque psoriasis. This revision focuses on the most recent oral and topical therapies available for psoriasis, especially those that are currently under evaluation and development for the treatment of psoriasis.

Navigating the landscape of psoriasis therapy: novel targeted pathways and emerging trends

INTRODUCTION

Psoriasis is a chronic, inflammatory, non-communicable skin disorder that affects a patient's social and emotional well-being. It is characterized by hyperproliferation of keratinocytes, irregular shedding of skin cells, and abnormal invasion of inflammatory mediators. The treatment strategy is designed based on the severity of the disease condition starting from topical, phototherapy, systemic, and biologics. In recent years, extensive research into the underlying mechanisms of psoriasis has led to significant advancement in treatment options from small molecules to biologics.

AREA COVERED

This review focuses on intracellular and molecular mechanisms such as AhR, A3AR, RIP1, CGRP, and S1P that serve as novel pharmacological targets for psoriasis. Moreover, new molecules are approved or are under clinical investigation to interfere with these target mechanisms.

EXPERT OPINION

A detailed understanding of signaling pathways provides potential targets and molecular mechanisms for the inflammatory cascade in psoriasis. This has led to the development of small molecules targeting specific pathways. Further, the combination of nanotechnology can assist in dose reduction leading to reduced adverse effects in the management of psoriasis.

Circ_0082476 targets miR-138-5p to promote proliferation, invasion, migration and inflammation in IL-22-treated human keratinocytes by upregulating BRD4

BACKGROUND

Circular RNAs (circRNAs) are implicated in the disease progression via acting as sponges of microRNAs (miRNAs) to regulate gene expression. The purpose of this study was to analyze the involvement of circ_0082476 in Interleukin-22 (IL-22)-induced psoriasis.

METHODS

Expression detection for circ_0082476, microRNA-424-5p (miR-138-5p) or toll-like receptor (BRD4) was completed using reverse transcription-quantitative polymerase chain reaction assay. Cell Counting Kit-8 assay and EdU assay were used for analysis of cell viability and proliferation, respectively. Cell invasion and migration abilities were assessed through transwell assay and wound healing assay. The protein expression was examined via western blot. Inflammatory reaction was determined via Enzyme-linked immunosorbent assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted for target binding research.

RESULTS

Circ_0082476 was significantly elevated in psoriasis patients and IL-22-treated keratinocytes (HaCaT). Knockdown of circ_0082476 reduced cell proliferation, invasion and migration in IL-22-treated HaCaT cells. Circ_0082476 induced sponge effect on miR-138-5p. Circ_0082476 regulated IL-22-induced cell injury through targeting miR-138-5p. BRD4 was confirmed as a target of miR-138-5p, and miR-138-5p relieved IL-22-induced cell dysfunction by the direct downregulation of BRD4. BRD4 was positively regulated by circ_0082476 via sponging miR-138-5p.

CONCLUSION

These findings disclosed that circ_0082476 facilitated the IL22-induced epidermis cell injury in psoriasis through the upregulation of BRD4 via binding to miR-138-5p.

Nanoscale Topical Pharmacotherapy in Management of Psoriasis: Contemporary Research and Scope

Psoriasis is a typical dermal condition that has been anticipated since prehistoric times when it was mistakenly implicit in being a variant of leprosy. It is an atypical organ-specific autoimmune disorder, which is triggered by the activation of T-cells and/or B-cells. Until now, the pathophysiology of this disease is not completely explicated and still, many research investigations are ongoing. Different approaches have been investigated to treat this dreadful skin disease using various anti-psoriatic drugs of different modes of action through smart drug-delivery systems. Nevertheless, there is no ideal therapy for a complete cure of psoriasis owing to the dearth of an ideal drug-delivery system for anti-psoriatic drugs. The conventional pharmacotherapy approaches for the treatment of psoriasis demand various classes of anti-psoriatic drugs with optimum benefit/risk ratio and insignificant untoward effects. The advancement in nanoscale drug delivery had a great impact on the establishment of a nanomedicine-based therapy for better management of psoriasis in recent times. Nanodrug carriers are exploited to design and develop nanomedicine-based therapy for psoriasis. It has a promising future in the improvement of the therapeutic efficacy of conventional anti-psoriatic drugs. The present manuscript aims to discuss the pathophysiology, conventional pharmacotherapy, and contemporary research in the area of nanoscale topical drug delivery systems for better management of psoriasis including the significance of targeted pharmacotherapy in psoriasis.

New Topical Therapies for Psoriasis

Psoriasis is a chronic immune-mediated skin disease with a significant impact on patients' quality of life. Mild-to-moderate forms of the disease usually require long-term topical treatment, but prolonged use of corticosteroids and vitamin D analogues is limited by adverse effects. With further understanding of psoriasis pathogenesis, new molecules are emerging aiming to fulfil these clinical needs. Tapinarof, an aryl hydrocarbon receptor modulator, has completed a phase III study and demonstrated good efficacy results, even in long treatment courses, with a favourable safety profile. It additionally appears to have a promising remitting effect as patients presented with an average relapsing time of over 3 months. Roflumilast, a phosphodiesterase type 4 inhibitor, also underwent a phase III study with significant lesion improvement and notable pruritus management, and with no reported side effects. Roflumilast was evaluated as an option for intertriginous areas with good outcomes in a small sample, but larger trials are required. The Janus kinase-signal transducer and activator of transcription pathway has been targeted in recent clinical investigations with promising options, currently with brepocitinib pending phase IIb results. Ongoing preclinical studies involving interleukin-2 inhibition, RNA modulators and amygdalin analogues may lead to forthcoming clinical trials. New topical drugs are successfully emerging and future research comparing them to classical options will dictate their clinical role in the treatment of psoriasis.

miR-489-3p inhibits TLR4/NF-κB signaling to prevent inflammation in psoriasis

Psoriasis is a chronic inflammatory skin disease whose etiology has not yet been determined. MicroRNAs (miRs) regulate the early stages of psoriasis and are targets for therapeutic intervention. The present study aimed to investigate the functional role of miR-489-3p in psoriasis. The present study first assessed the expression levels of miR-489-3p and Toll-like receptor (TLR)4 mRNA using reverse transcription-quantitative PCR, and also detected the protein expression levels of TLR4 and NF-κB via western blot analysis. TargetScan and miRDB target gene prediction tools were used to confirm the regulation of Toll-like receptor (TLR)4 by miR-489-3p. Moreover, a Cell Counting Kit (CCK)-8 assay was conducted to evaluate cell viability, while cell cycle and colony formation assays were performed to evaluate cell proliferation. Human keratinocytes (HaCaT) were co-transfected with TLR4-small interfering RNA and miR-489-3p-inhibitor plasmids, and analysis of cell proliferation and inflammatory cytokine secretion was performed using CCK-8 assay and ELISA. It was found that miR-489-3p expression was downregulated in patients with psoriasis. Bioinformatics analysis identified that TLR4 was a direct target of miR-489-3p. This was confirmed via luciferase reporter assays in HaCaT cells. The overexpression of miR-489-3p inhibited the TLR4/NF-κB signaling pathway and reduced cell proliferation. TLR4 silencing alleviated the effects of miR-489-3p, and enhanced cell proliferation and inflammatory cytokine secretion. Taken together, these data suggested that miR-489-3p may be a key effector of psoriasis, which promotes inflammatory responses by direct targeting of TLR4. miR-489-3p therefore represents a promising prognostic biomarker and therapeutic target for psoriasis treatment.

EZH2 is involved in psoriasis progression by impairing miR-125a-5p inhibition of SFMBT1 and leading to inhibition of the TGFβ/SMAD pathway

Aims:

In this study, we aimed to decipher the impact of enhancer of zeste homolog 2 (EZH2) in psoriasis as well as the underlying mechanism.

Methods:

A mouse model of psoriasis was developed by means of imiquimod induction, with the expression of EZH2, microRNA-125a-5p (miR-125a-5p), and SFMBT1 determined. The role of EZH2, miR-125a-5p, and SFMBT1 in malignant phenotypes of HaCaT cells and the development of psoriasis in vivo was subsequently investigated through gain- and loss-of-function experiments. Chromatin immunoprecipitation assay and dual-luciferase reporter assay were conducted to explore the relationship between EZH2 or SFMBT1 and miR-125a-5p. Finally, the effects of EZH2 and miR-125a-5p on the transforming growth factor β (TGFβ)/SMAD pathway were analyzed.

Results:

Overexpressed SFMBT1 and EZH2 was detected while miR-125a-5p were downregulated in psoriasis tissues and human keratinocyte (HaCaT) cells. EZH2 increased the levels of IL-17A-induced cytokines and promoted the malignant phenotypes of HaCaT cells. Functionally, EZH2 reduced miR-125a-5p expression while miR-125a-5p targeted SFMBT1 to activate the TGFβ/SMAD pathway in vitro. Knockdown of EZH2 or up-regulation of miR-125a-5p inhibited cell proliferation and the levels of IL-17A-induced cytokines, but increased the expression of TGFβ1 and the extent of smad2 and smad3 phosphorylation in HaCaT cells. Notably, EZH2 contributed to the development of psoriasis in vivo by inhibiting the TGFβ/SMAD pathway via impairment of miR-125a-5p-mediated SFMBT1 inhibition.

Conclusion:

Taken together, the results of the current study highlight the ability of EZH2 to potentially inactivate the TGFβ/SMAD pathway via upregulation of miR-125a-5p-dependent SFMBT1during the progression of psoriatic lesions.