miR‑125b‑mediated regulation of cell proliferation through the Jagged‑1/Notch signaling pathway by inhibiting BRD4 expression in 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.

MicroRNA-21 and MicroRNA-125b expression in skin tissue and serum as predictive biomarkers for psoriasis

BACKGROUND/OBJECTIVE

Psoriasis is a chronic, inflammatory, and hyperproliferative skin disease. We have investigated the role of miR-21 and miR-125b in the development of psoriasis and atopic eczema and their relation with the severity of the diseases.

METHODS

Participants included 40 psoriasis patients, 40 healthy controls, and 40 atopic eczema patients as a positive control group. In addition, analysis of mRNA expression of miR-125b and miR-21 was carried out utilizing quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) in serum samples and skin tissue.

RESULTS

Our results have demonstrated that miR-21 was significantly overexpressed in the psoriatic and atopic eczema skin tissue and serum samples compared to controls, whereas miR-125b was significantly down-expressed in psoriatic and atopic eczema skin tissues and serum samples. There was a statistically significant positive correlation between the psoriasis area and severity index (PASI) score and miR-21 among the studied groups in both serum and tissue samples. In contrast, there was a statistically significant negative association between the miR-125b and PASI score. On the other hand, there was no significant relation between the extent of body surface area (BSA), intensity, and subjective symptoms using visual analog scale (VAS) of atopic eczema disease and miRNA-21 and miRNA-125b in both tissue and serum.

CONCLUSION

In conclusion, miR-21 gene expression was significantly increased in psoriatic and atopic eczema skin samples and serum samples, whereas miR-125b was statistically lowered in psoriatic and atopic eczema patient samples. The miR-21 and miR-125b expression level has a possible predictive value as a marker for psoriasis severity but not for atopic eczema severity.

Signaling pathways and targeted therapies for psoriasis

Psoriasis is a common, chronic, and inflammatory skin disease with a high burden on individuals, health systems, and society worldwide. With the immunological pathologies and pathogenesis of psoriasis becoming gradually revealed, the therapeutic approaches for this disease have gained revolutionary progress. Nevertheless, the mechanisms of less common forms of psoriasis remain elusive. Furthermore, severe adverse effects and the recurrence of disease upon treatment cessation should be noted and addressed during the treatment, which, however, has been rarely explored with the integration of preliminary findings. Therefore, it is crucial to have a comprehensive understanding of the mechanisms behind psoriasis pathogenesis, which might offer new insights for research and lead to more substantive progress in therapeutic approaches and expand clinical options for psoriasis treatment. In this review, we looked to briefly introduce the epidemiology, clinical subtypes, pathophysiology, and comorbidities of psoriasis and systematically discuss the signaling pathways involving extracellular cytokines and intracellular transmission, as well as the cross-talk between them. In the discussion, we also paid more attention to the potential metabolic and epigenetic mechanisms of psoriasis and the molecular mechanistic cascades related to its comorbidities. This review also outlined current treatment for psoriasis, especially targeted therapies and novel therapeutic strategies, as well as the potential mechanism of disease recurrence.

A panel of blood-based circulatory miRNAs with diagnostic potential in patients with psoriasis

Psoriasis is a chronic inflammatory skin disease with keratinocyte hyperproliferation and T cells as key mediators of lesional and systemic inflammatory changes. To date, no suitable differential biomarkers are available for the disease diagnosis. More recently, microRNAs have been identified as critical regulators of lesional and systemic immune changes in psoriasis with diagnostic potential. We have performed expression profiling of T cell-specific miRNAs in 38 plasma samples from psoriasis vulgaris patients and an equal number of age- and gender-matched healthy subjects. Our findings have identified a panel of five blood-based circulatory miRNAs with a significant change in their expression levels, comprising miR-215, miR-148a, miR-125b-5p, miR-223, and miR-142-3p, which can differentiate psoriasis vulgaris patients from healthy individuals. The receiver operating characteristic (ROC) curves for all five miRNAs individually and in combination exhibited a significant disease discriminatory area under the curve with an AUC of 0.762 and a p < 0.0001 for all the miRNAs together. Statistically, all five miRNAs in combination depicted the best-fit model in relation to disease severity (PASI) compared with individual miRNAs, with the highest R2 value of 0.94 and the lowest AIC score of 131.8. Each of the miRNAs also exhibited a significant association with at least one of the other miRNAs in the panel. Importantly, the five miRNAs in the panel regulate one or more immune-inflammation pathways based on target prediction, pathway network analysis, and validated roles in the literature. The miRNA panel provides a rationalized combination of biomarkers that can be tested further on an expanded cohort of patients for their diagnostic value.

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.

Annoying Psoriasis and Atopic Dermatitis: A Narrative Review

Skin is an important organ that mainly functions as a barrier. Skin diseases can damage a person's self-confidence and reduce their willingness to socialize, as well as their social behavior and willingness. When the skin appearance is abnormal, in addition to affecting the quality of life, it often leads to personal, social, and psychological dysfunction and even induces depression. Psoriasis and atopic dermatitis are common chronic skin diseases. Their prevalence in the world is 3-10%, and there is an increasing trend year by year. These congenital or acquired factors cause the dysfunction of the immune system and then destroy the barrier function of the skin. Because these patients are flooded with a variety of inflammatory mediators, this causes skin cells to be in chronic inflammation. Therefore, psoriasis and atopic dermatitis are also considered systemic chronic inflammatory diseases. In the healthcare systems of developed countries, it is unavoidable to spend high costs to relieve symptoms of psoriasis and atopic dermatitis patients, because psoriasis and atopic dermatitis have a great influence on individuals and society. Giving a lot of attention and developing effective treatment methods are the topics that the medical community must work on together. Therefore, we used a narrative review manuscript to discuss pathogenesis, clinical classification, incidence, and treatment options, including topical medication, systemic therapeutics, immunosuppressive medication for psoriasis, and atopic dermatitis, as well as also comparing the differences between these two diseases. We look forward to providing readers with comprehensive information on psoriasis and atopic dermatitis through this review article.

Peroxisome proliferator-activator receptor γ and psoriasis, molecular and cellular biochemistry

The pathophysiology of psoriasis is complex and has not been completely elucidated. Better understanding of the pathogenesis may contribute to further improvement of our therapeutic strategies controlling psoriasis. Emerging evidence points to a causative relationship between altered activity of peroxisome proliferator-activated receptor γ (PPARγ) and psoriasis. The present review focuses on deeper understanding of the possible role of PPARγ in the pathogenesis of psoriasis and the potential of PPARγ agonist to improve the treatment of psoriasis. PPARγ is decreased in psoriasis. PPARγ possibly has effects on the multiple aspects of the pathogenesis of psoriasis, including abnormal lipid metabolism, insulin resistance, immune cells, pro-inflammatory cytokines, keratinocytes, angiogenesis, oxidative stress, microRNAs and nuclear factor kappa B. As defective activation of PPARγ is involved in psoriasis development, PPARγ agonists may be promising agents for treatment of psoriasis. Pioglitazone appears an effective and safe option in the treatment of patients with psoriasis, but there are still concerns about its potential side effects. Research effort has recently been undertaken to explore the PPARγ-activating potential of natural products. Among them some have been studied clinically or preclinically for treatment of psoriasis with promising results.

Inhibition of BRD4 inhibits proliferation and promotes apoptosis of psoriatic keratinocytes

Background

Psoriasis is a common chronic recurrent inflammatory skin disease. The pathogenesis of psoriasis, such as other autoimmune diseases, is still unclear, which brings great difficulties to the treatment. This study aimed to investigate the role of bromine domain protein 4 (BRD4) in affecting the psoriatic keratinocytes.

Methods

Imiquimod-induced psoriasis mice model and TNF-α or IL-17A induced HaCAT cells, an experimental model in vitro for psoriasis, were constructed. The pathological skin changes at the back of mice were observed by hematoxylin and eosin (H&E) assay and evaluated by psoriasis area and severity index (PASI). KI67 expression and keratinocyte apoptosis at the skin tissues were, respectively, detected by Immunohistochemical analysis and TUNEL assay. The inflammatory factors in mice serum and culture supernatant were determined by ELISA assay. The related proteins expression of proliferation, apoptosis and MAPK pathway were detected by Western blot analysis.

Results

BRD4 expression was upregulated in injured skin on the back of imiquimod-induced mice and (+)-JQ1 relieved the skin injury by suppressing the inflammation and promoting apoptosis of keratinocytes. Consistently, BRD4 expression was also increased in TNF-α or IL-17A induced HaCAT cells. (+)-JQ1 suppressed the viability and inflammation, and promoted apoptosis of TNF-α or IL-17A induced HaCAT cells. In addition, the MAPK signaling pathway was inhibited by (+)-JQ1 whether in mice or HaCAT cells.

Conclusions

Inhibition of BRD4 inhibited proliferation and inflammation and promoted apoptosis of psoriatic keratinocytes.

The Genetic Variants of NOTCH3 (6746T>C) and PSMA6 (-8C>G) as Possible Risk Factors of Psoriasis Development

Advances in genotypic technologies enable identification of possible associations between genetic variants of certain genes and increased risk of developing plaque psoriasis or psoriatic arthritis. The aim of the study was to analyze the NOTCH3 (6746T>C) (rs1044009) and PSMA6 (-8C>G) (rs1048990) polymorphisms and their role in genetic susceptibility to psoriasis. The study included 158 psoriatic patients and 100 healthy controls. The frequencies of the NOTCH3 genotypes differed between the psoriatic patients and healthy controls (p = 0.050). No differences were found in the distribution of PSMA6 genotypes and alleles between the psoriatic patients and healthy controls. The studied psoriatic patients presented a higher frequency of the CC genotype of PSMA6 compared to the healthy controls (8.8% vs. 2%, respectively). Psoriatic arthritis was more frequent among patients with the CC genotype of PSMA6 (p = 0.059). CC homozygosity of NOTCH3 was more commonly observed in the studied psoriatic patients than in the healthy controls (OR = 4.76, p= 0.032). The obtained data suggest that genetic variants of NOTCH3 (6746T>C) and PSMA6 (-8C>G) genes may play significant roles in psoriatic patients. Further studies are necessary to unequivocally determine their role as genetic risk factors of psoriasis development.

The Role of Epigenetic Factors in Psoriasis

Psoriasis is a chronic, systemic, immune-mediated disease with an incidence of approximately 2%. The pathogenesis of the disease is complex and not yet fully understood. Genetic factors play a significant role in the pathogenesis of the disease. In predisposed individuals, multiple trigger factors may contribute to disease onset and exacerbations of symptoms. Environmental factors (stress, infections, certain medications, nicotinism, alcohol, obesity) play a significant role in the pathogenesis of psoriasis. In addition, epigenetic mechanisms are considered result in modulation of individual gene expression and an increased likelihood of the disease. Studies highlight the significant role of epigenetic factors in the etiology and pathogenesis of psoriasis. Epigenetic mechanisms in psoriasis include DNA methylation, histone modifications and non-coding RNAs. Epigenetic mechanisms induce gene expression changes under the influence of chemical modifications of DNA and histones, which alter chromatin structure and activate transcription factors of selected genes, thus leading to translation of new mRNA without affecting the DNA sequence. Epigenetic factors can regulate gene expression at the transcriptional (via histone modification, DNA methylation) and posttranscriptional levels (via microRNAs and long non-coding RNAs). This study aims to present and discuss the different epigenetic mechanisms in psoriasis based on a review of the available literature.

miRNAs Flowing Up and Down: The Concerto of Psoriasis

Psoriasis is a chronic immune-mediated skin disease, whose hallmarks include keratinocyte hyperproliferation and CD4⁺ T cell subsets imbalance. Dysregulated microRNAs (miRNAs) identified in psoriasis have been shown to affect keratinocyte and T cell functions, with studies on the molecular mechanisms and intrinsic relationships of the miRNAs on the way. Here, we focus on the dysregulated miRNAs that contribute to the two hallmarks of psoriasis with the miRNA target genes confirmed. We review a network, in which, upregulated miR-31/miR-203/miR-155/miR-21 and downregulated miR-99a/miR-125b facilitate the excessive proliferation and abnormal differentiation of psoriatic keratinocytes; upregulated miR-210 and downregulated miR-138 work in concert to distort CD4⁺ T cell subsets balance in psoriasis. The miRNAs exert their functions through regulating key psoriasis-associated transcription factors including NF-κB and STAT3. Whether flowing up or down, these miRNAs collaborate to promote the development and maintenance of psoriasis.

The Role of MicroRNAs in Epidermal Barrier

MicroRNAs (miRNAs), which mostly cause target gene silencing via transcriptional repression and degradation of target mRNAs, regulate a plethora of cellular activities, such as cell growth, differentiation, development, and apoptosis. In the case of skin keratinocytes, the role of miRNA in epidermal barrier integrity has been identified. Based on the impact of key genetic and environmental factors on the integrity and maintenance of skin barrier, the association of miRNAs within epidermal cell differentiation and proliferation, cell-cell adhesion, and skin lipids is reviewed. The critical role of miRNAs in the epidermal barrier extends the use of miRNAs for control of relevant skin diseases such as atopic dermatitis, ichthyoses, and psoriasis via miRNA-based technologies. Most of the relevant miRNAs have been associated with keratinocyte differentiation and proliferation. Few studies have investigated the association of miRNAs with structural proteins of corneocytes and cornified envelopes, cell-cell adhesion, and skin lipids. Further studies investigating the association between regulatory and structural components of epidermal barrier and miRNAs are needed to elucidate the role of miRNAs in epidermal barrier integrity and their clinical implications.

The eminent roles of ncRNAs in the pathogenesis of psoriasis

Psoriasis is a chronic immune-related disorder in which both genetic and environmental parameters are involved. Recent studies have demonstrated dysregulation of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the peripheral blood or skin lesions of patients with psoriasis. While a number of lncRNAs such as MEG3, AL162231.4 and NONHSAT044111 have been down-regulated in the course of psoriasis, others including PRINS, MIR31HG, RP6‐65G23.1, MSX2P1, SLC6A14-1:1, NR_003062 have been up-regulated. Moreover, expressions of several miRNAs have been dysregulated in this disorder. Among dysregulated miRNAs are miR-126, miR-143, miR-19a and miR-155 whose diagnostic roles in the psoriasis have also been assessed. Dysregulated non-coding RNAs in this disorder participate in the regulation of chemokine signaling pathway and immune response, control of epidermal development and skin barrier as well as modulation of function of certain subsets of T cells. Besides, these transcripts possibly regulate activity of NF-κΒ, mTOR, MAPK and JAK-STAT signaling pathways. Besides, expression levels of circRNAs have been decreased in the psoriasis lesions. Massive alterations in the levels of lncRNAs and miRNAs in the psoriasis lesions or peripheral blood of affected individuals show participation of these transcripts in the pathogenesis of this disorder.