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

Protective effect and regulatory mechanism of salidroside on skin inflammation induced by imiquimod in psoriasis mice

Salidroside (SAL) is a glucoside of tyrosol commonly existing in the roots of Rhodiola rosea. This study unveils the protective effect of SAL on skin inflammation in imiquimod (IMQ)-induced psoriasis. The mouse model of psoriasis was established by local application of IMQ, and SAL efficacy was evaluated through PASI scoring, H&E staining, and skin tissue pathology observation. The HaCaT cell model was established by interferon (IFN)-γ induction, followed by MTT assay detection of cell viability, detection of ROS, SOD, MDA, and CAT levels in skin tissues and cells using reagent kits, ELISA detection of inflammatory factors (TNF-α, IL-6, IL-1β), and qRT-PCR detection of psoriasis-related genes (S100a9, Cxcl1, Cxcl2) as well as miR-369-3p and SMAD2 expressions. The binding relationship between miR-369-3p and SMAD2 was validated using dual-luciferase reporter assay. SAL treatment reduced PASI scores and alleviated psoriasis symptoms of IMQ-induced mice, and also augmented the viability and subsided the oxidative stress and inflammation of IFN-γ-treated HaCaT cells. SAL treatment restrained miR-369-3p expression but elevated SMAD2 expression. Mechanistically, miR-369-3p targeted SMAD2 expression. miR-369-3p overexpression or SMAD2 inhibition partially offset the alleviating effect of SAL on psoriasis skin inflammation. In conclusion, SAL alleviates skin inflammation in IMQ-induced psoriasis mice via the miR-369-3p/SMAD2 axis.

HOMER3 promotes liver hepatocellular carcinoma cancer progression by -upregulating EZH2 and mediating miR-361/GPNMB axis

Liver hepatocellular carcinoma (LIHC) is among the most lethal human cancers. Studies have shown that Homer scaffold protein 3 (HOMER3) plays important roles in various diseases and cancers, but its biological function and molecular mechanism in LIHC have never been investigated. Our study discovered the aberrantly high expression of HOMER3 and its promising diagnostic and prognostic significance in LIHC. Functionally, HOMER3 knockdown inhibited the proliferative and migrative abilities of LIHC cells and tumor growth in vivo. Mechanically, HOMER3 mediated the aggressiveness of LIHC cells via GPNMB. Meanwhile, miR-361 directly targeted GPNMB and attenuated LIHC progression by suppressing GPNMB expression. The regulatory effect of HOMER3 during LIHC progression was exerted through the miR-361/GPNMB axis. Furthermore, EZH2 supplementation or miR-361 depletion effectively abated the tumor-suppressive effect of HOMER3 knockdown on LIHC progression. In conclusion, HOMER3 mediated LIHC progression through the EZH2/miR-361/GPNMB axis.

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 Mechanism of Astragaloside IV in NOD-like Receptor Family Pyrin Domain Containing 3 Inflammasome-mediated Pyroptosis after Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is one of the most common subtypes of stroke.

OBJECTIVES

This study aimed to investigate the mechanism of Astragaloside IV (AS-IV) on inflammatory injury after ICH.

METHODS

The ICH model was established by the injection of collagenase and treated with ASIV (20 mg/kg or 40 mg/kg). The neurological function, water content of the bilateral cerebral hemisphere and cerebellum, and pathological changes in brain tissue were assessed. The levels of interleukin-1 beta (IL-1β), IL-18, tumor necrosis factor-alpha, interferon-gamma, and IL-10 were detected by enzyme-linked immunosorbent assay. The levels of Kruppel-like factor 2 (KLF2), NOD-like receptor family pyrin domain containing 3 (NLRP3), GSDMD-N, and cleaved-caspase-1 were detected by reverse transcription-quantitative polymerase chain reaction and Western blot assay. The binding relationship between KLF2 and NLRP3 was verified by chromatin-immunoprecipitation and dual-luciferase assays. KLF2 inhibition or NLRP3 overexpression was achieved in mice to observe pathological changes.

RESULTS

The decreased neurological function, increased water content, severe pathological damage, and inflammatory response were observed in mice after ICH, with increased levels of NLRP3/GSDMD-N/cleaved-caspase-1/IL-1β/IL-18 and poorly-expressed KLF2 in brain tissue. After AS-IV treatment, the neurological dysfunction, high brain water content, inflammatory response, and pyroptosis were alleviated, while KLF2 expression was increased. KLF2 bonded to the NLRP3 promoter region and inhibited its transcription. Down-regulation of KLF2 or upregulation of NLRP3 reversed the effect of AS-IV on inhibiting pyroptosis and reducing inflammatory injury in mice after ICH.

CONCLUSION

AS-IV inhibited NLRP3-mediated pyroptosis by promoting KLF2 expression and alleviated inflammatory injury in mice after ICH.

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.

Insights into Nutritional Strategies in Psoriasis

Psoriasis, an autoimmune chronic inflammatory skin condition, has a high incidence in the general population, reaching 2-4%. Its pathogenesis involves an interplay of genetic factors, immune disturbances, and environmental factors. Within the environmental factors that aid the appearance of this autoimmune skin disease, the Western lifestyle and overall diet play important roles in the steady growth in psoriasis prevalence. Furthermore, psoriasis is associated with comorbidities such as psoriatic arthritis, cardiovascular disease, metabolic syndrome, and obesity. Accumulating evidence suggests that obesity is an important risk factor for psoriasis. Moreover, obesity aggravates established psoriasis, and a reduction in the body mass index can improve the clinical outcomes of psoriasis and increase the efficacy of standard psoriasis therapies. The possible connection between this autoimmune disease and obesity relies on the fact that white adipose tissue is an essential endocrine organ that secretes an array of immune mediators and inflammatory and metabolic factors with pro-inflammatory action. Thus, immune-mediated mechanisms in both psoriasis and obesity conditions are common factors. This paper describes the factors that link obesity with skin autoimmune disease and highlights the importance of the stimulatory or regulatory effects of nutrients and food in psoriasis and the possible improvement of psoriasis through nutritional strategies.

Vitamin D receptor-deficient keratinocytes-derived exosomal miR-4505 promotes the macrophage polarization towards the M1 phenotype

BACKGROUND

The vitamin D receptor (VDR) has a low level of expression in the keratinocytes of patients with psoriasis and plays a role in the development of the disease. Furthermore, the crosstalk between macrophages and psoriatic keratinocytes-derived exosomes is critical for psoriasis progression. However, the effects of VDR-deficient keratinocytes-derived exosomes (Exos-shVDR) on macrophages and their underlying mechanisms remain largely unknown.

METHODS

VDR-deficient keratinocytes were constructed by infecting HaCaT cells with a VDR-targeting lentivirus, mimicking the VDR-deficient state observed in psoriatic keratinocytes. Exosomes were characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blot. The effect of Exos-shVDR on macrophage proliferation, apoptosis, and M1/M2 polarization was assessed using cell counting kit-8 assay (CCK-8), flow cytometer, real-time quantitative polymerasechain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The mechanism underlying the effect of Exos-shVDR on macrophage function was elucidated through data mining, bioinformatics, RT-qPCR, and rescue experiments.

RESULTS

Our results revealed that both Exos-shVDR and Exos-shNC exhibited typical exosome characteristics, including a hemispheroid shape with a concave side and particle size ranging from 50 to 100 nm. The levels of expression of VDR were significantly lower in Exos-shVDR than in Exos-shNC. Functional experiments demonstrated that Exos-shVDR significantly promoted macrophage proliferation and polarization towards the M1 phenotype while inhibiting macrophage apoptosis. Moreover, miR-4505 was highly expressed in the skin tissue of patients with psoriasis. Its overexpression significantly increased macrophage proliferation and polarization towards M1 and inhibited apoptosis. Furthermore, the effects of Exos-shVDR on macrophage function occur through miR-4505.

CONCLUSIONS

Exos-shVDR exacerbates macrophage proliferation, promotes polarization towards the M1 phenotype, and inhibits macrophage apoptosis by increasing the levels of miR-4505. These results indicate that modulation of macrophage function is a potential strategy for developing new drugs for the treatment 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.

Gene set enrichment analysis and ingenuity pathway analysis to verify the impact of Wnt signaling in psoriasis treated with Taodan granules

BACKGROUND

Taodan granules (TDGs), traditional Chinese herbals, have effectiveness in relieving skin erythema, scales, and other symptoms of psoriasis. Yet mechanisms of TDGs remain indistinct.

OBJECTIVE

To indicate the molecular mechanisms of TDGs in treating psoriasis.

MATERIALS AND METHODS

Primarily, transcriptional profiling was applied to identify differentially expressed genes (DEGs), proceeding with Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) analysis were used for functional enrichment analysis. Subsequently, levels of selected genes were validated by RT-PCR and western blotting.

RESULTS

The GSEA results revealed TDGs could down-regulate the Wnt signaling pathway to ameliorate skin lesions of imiquimod (IMQ)-induced psoriatic models mice. IPA core network associated with Wnt signaling pathways in TDGs for psoriasis was established. Thereinto zeste homolog 2 (EZH2), CTNNB1, tumor protein p63 (TP63), and WD repeat domain 5 (WDR5) were considered as upstream genes in the Wnt signaling pathway. Experimental verification indicated TDGs could down-regulate EZH2, CTNNB1, and WDR5 at the mRNA and protein levels, along with up-regulate TP63 levels. Moreover, TDGs were confirmed to reduce RAC2 and WNT5A at mRNA and protein levels of the Wnt signaling pathway.

CONCLUSIONS

TDGs may improve psoriasis through the regulation for upstream genes (down-regulating levels of EZH2, CTNNB1, and WDR5; up-regulating TP63 levels) of Wnt signaling pathway, thus reducing levels of RAC2 and WNT5A in the Wnt signaling pathway.

Mouse Models of Psoriasis: A Comprehensive Review

The use of preclinical animal models of psoriasis has significantly increased over the last three decades, with each model having unique strengths and limitations. Some models translate better to human disease, and many have provided unique insight into psoriasis disease pathogenesis. In this comprehensive review, we present a comparative description and discussion of genetic mouse models, xenograft approaches, and elicited methods using cytokine injections into and topical imiquimod onto mice. We provide an inclusive list of genetically modified animals that have had imiquimod applied to or cytokines injected into their skin and describe the outcomes of these manipulations. This review will provide a valuable resource for those interested in working with psoriasis animal models.