Acitretin modulates HaCaT cells proliferation through STAT1- and STAT3-dependent signaling

Targeted siRNA Therapy for Psoriasis: Translating Preclinical Potential into Clinical Treatments

Psoriasis is a chronic inflammatory skin disease characterized by the excessive proliferation of keratinocytes and heightened immune activation. Targeting pathogenic genes through small interfering RNA (siRNA) therapy represents a promising strategy for the treatment of psoriasis. This mini-review provides a comprehensive summary of siRNA research targeting the pathogenesis of psoriasis, covering aspects such as keratinocyte function, inflammatory cell roles, preclinical animal studies, and siRNA delivery mechanisms. It details recent advancements in RNA interference that modulate key factors including keratinocyte proliferation (Fibroblast Growth Factor Receptor 2, FGFR2), apoptosis (Interferon Alpha Inducible Protein 6, G1P3), differentiation (Grainyhead Like Transcription Factor 2, GRHL2), and angiogenesis (Vascular Endothelial Growth Factor, VEGF); immune cell infiltration and inflammation (Tumor Necrosis Factor-Alpha, TNF-α; Interleukin-17, IL-17); and signaling pathways (JAK-STAT, Nuclear Factor Kappa B, NF-κB) that govern immunopathology. Despite significant advances in siRNA-targeted treatments for psoriasis, several challenges persist. Continued scientific developments promise the creation of more effective and safer siRNA medications, potentially enhancing the quality of life for psoriasis patients and revolutionizing treatments for other diseases. This article focuses on the most recent research advancements in targeting the pathogenesis of psoriasis with siRNA and explores its future therapeutic prospects.

Anti-Photodamage Effect of Agaricus blazei Murill Polysaccharide on UVB-Damaged HaCaT Cells

UVB radiation is known to induce photodamage to the skin, disrupt the skin barrier, elicit cutaneous inflammation, and accelerate the aging process. Agaricus blazei Murill (ABM) is an edible medicinal and nutritional fungus. One of its constituents, Agaricus blazei Murill polysaccharide (ABP), has been reported to exhibit antioxidant, anti-inflammatory, anti-tumor, and immunomodulatory effects, which suggests potential effects that protect against photodamage. In this study, a UVB-induced photodamage HaCaT model was established to investigate the potential reparative effects of ABP and its two constituents (A1 and A2). Firstly, two purified polysaccharides, A1 and A2, were obtained by DEAE-52 cellulose column chromatography, and their physical properties and chemical structures were studied. A1 and A2 exhibited a network-like microstructure, with molecular weights of 1.5 × 104 Da and 6.5 × 104 Da, respectively. The effects of A1 and A2 on cell proliferation, the mitochondrial membrane potential, and inflammatory factors were also explored. The results show that A1 and A2 significantly promoted cell proliferation, enhanced the mitochondrial membrane potential, suppressed the expression of inflammatory factors interleukin-1β (IL-1β), interleukin-8 (IL-8), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), and increased the relative content of filaggrin (FLG) and aquaporin-3 (AQP3). The down-regulated JAK-STAT signaling pathway was found to play a role in the response to photodamage. These findings underscore the potential of ABP to ameliorate UVB-induced skin damage.

A Review of the Research Applications of Centipeda minima

Centipeda minima is a traditional Chinese medicine with wide applications and diverse pharmacological effects. Scholars have conducted extensive studies on its relevant clinical applications, especially its remarkable efficacy in cancer treatment. This paper thoroughly investigates the chemical composition and identification, pharmacological effects, and toxicity, along with the safety of Centipeda minima, so as to lay the foundation for corresponding clinical applications and product development. Furthermore, as global scholars have conducted extensive research on such clinical applications and made significant progress, the future development and utilization of Centipeda minima's active ingredients to create novel drugs are of great clinical significance.

Cold Physical Plasma-Mediated Fenretinide Prodrug Activation Confers Additive Cytotoxicity in Epithelial Cells

Cold physical plasma is a partially ionized gas operated at body temperature and utilized for heat-sensitive technical and medical purposes. Physical plasma is a multi-component system consisting of, e.g., reactive species, ions and electrons, electric fields, and UV light. Therefore, cold plasma technology is an interesting tool for introducing biomolecule oxidative modifications. This concept can be extended to anticancer drugs, including prodrugs, which could be activated in situ to enhance local anticancer effects. To this end, we performed a proof-of-concept study on the oxidative prodrug activation of a tailor-made boronic pinacol ester fenretinide treated with the atmospheric pressure argon plasma jet kINPen operated with either argon, argon-hydrogen, or argon-oxygen feed gas. Fenretinide release from the prodrug was triggered via Baeyer-Villiger-type oxidation of the boron-carbon bond based on hydrogen peroxide and peroxynitrite, which were generated by plasma processes and chemical addition using mass spectrometry. Fenretinide activation led to additive cytotoxic effects in three epithelial cell lines in vitro compared to the effects of cold plasma treatment alone regarding metabolic activity reduction and an increase in terminal cell death, suggesting that cold physical plasma-mediated prodrug activation is a new direction for combination cancer treatment studies.

Genetic and Epigenetic Host-Virus Network to Investigate Pathogenesis and Identify Biomarkers for Drug Repurposing of Human Respiratory Syncytial Virus via Real-World Two-Side RNA-Seq Data: Systems Biology and Deep-Learning Approach

Human respiratory syncytial virus (hRSV) affects more than 33 million people each year, but there are currently no effective drugs or vaccines approved. In this study, we first constructed a candidate host-pathogen interspecies genome-wide genetic and epigenetic network (HPI-GWGEN) via big-data mining. Then, we employed reversed dynamic methods via two-side host-pathogen RNA-seq time-profile data to prune false positives in candidate HPI-GWGEN to obtain the real HPI-GWGEN. With the aid of principal-network projection and the annotation of KEGG pathways, we can extract core signaling pathways during hRSV infection to investigate the pathogenic mechanism of hRSV infection and select the corresponding significant biomarkers as drug targets, i.e., TRAF6, STAT3, IRF3, TYK2, and MAVS. Finally, in order to discover potential molecular drugs, we trained a DNN-based DTI model by drug-target interaction databases to predict candidate molecular drugs for these drug targets. After screening these candidate molecular drugs by three drug design specifications simultaneously, i.e., regulation ability, sensitivity, and toxicity. We finally selected acitretin, RS-67333, and phenformin to combine as a potential multimolecule drug for the therapeutic treatment of hRSV infection.

Transcriptome Analysis of the Immortal Human Keratinocyte HaCaT Cell Line Damaged by Tritiated Water

Radioactive elements, such as tritium, have been released into the ocean in large quantities as a result of the reactor leakage accident. In this study, an MTT assay demonstrated that the viability of HacaT cells decreased after tritiated water treatment. Bioinformatics analysis was used to analyze gene changes in the HacaT cells. The sequencing results showed 267 significantly differentially expressed genes (DEGs), and GO enrichment analysis showed that the DEGs were mainly divided into three parts. The KEGG pathway analysis showed that the up-regulated DEGs were involved in Wnt and other pathways, while the down-regulated DEGs were involved in Jak–STAT and others. A Western blot assay was used to verify the parts of the sequencing results. This study was the first to explore the mechanism of tritiated water on HacaT cells using Transcriptome analysis. The results will provide a theoretical basis for the study of tritiated water hazard mechanisms.

Centipeda minima Extract Inhibits Inflammation and Cell Proliferation by Regulating JAK/STAT Signaling in Macrophages and Keratinocytes

Psoriasis, a chronic inflammation-mediated skin disease, affects 2-3% of the global population. It is characterized by keratinocyte hyperproliferation and immune cell infiltration. The JAK/STAT3 and JAK/STAT1 signaling pathways play an important role in the development of psoriasis when triggered by IL-6 and IFN-γ, which are produced by dendritic cells and T-lymphocytes. Thus, blocking JAK/STAT signaling may be a potential strategy for treating psoriasis. Therefore, we examined the effects of CMX, an extract of Centipeda minima enriched in Brevilin A, Arnicolide D, Arnicolide C, and Microhelenin C, on macrophages and keratinocytes. We established an in vitro model of psoriasis, based on an inflammation-associated keratinocyte proliferation model, and used macrophages and keratinocytes treated with LPS, IL-6, or IFN-γ to evaluate the effect of CMX. We found that CMX reduced pro-inflammatory cytokine production, by inhibiting lipopolysaccharide (LPS)-induced JAK1/2 and STAT1/3 phosphorylation in macrophages. Moreover, CMX-downregulated chemokine expression and cell proliferation compared with components in HaCaT cells, induced by rh-IL-6 and rh-IFN-γ, respectively. Consistently, we demonstrated that the reduction in chemokine expression and hyperproliferation was mediated by the regulation of IFN-γ-activated JAK/STAT1 and IL-6-activated JAK/STAT3 signaling. In conclusion, CMX inhibited JAK/STAT-mediated inflammatory responses and cell proliferation in macrophages and keratinocytes. Consequently, CMX may have potential uses as a therapeutic agent for treating psoriasis.

The Use of Retinoids for the Prevention and Treatment of Skin Cancers: An Updated Review

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.

Drug repositioning: Progress and challenges in drug discovery for various diseases

Compared with traditional de novo drug discovery, drug repurposing has become an attractive drug discovery strategy due to its low-cost and high efficiency. Through a comprehensive analysis of the candidates that have been identified with drug repositioning potentials, it is found that although some drugs do not show obvious advantages in the original indications, they may exert more obvious effects in other diseases. In addition, some drugs have a synergistic effect to exert better clinical efficacy if used in combination. Particularly, it has been confirmed that drug repositioning has benefits and values on the current public health emergency such as the COVID-19 pandemic, which proved the great potential of drug repositioning. In this review, we systematically reviewed a series of representative drugs that have been repositioned for different diseases and illustrated successful cases in each disease. Especially, the mechanism of action for the representative drugs in new indications were explicitly explored for each disease, we hope this review can provide important insights for follow-up research.

Acitretin-Conjugated Dextran Nanoparticles Ameliorate Psoriasis-like Skin Disease at Low Dosages

Psoriasis is a common chronic inflammatory skin disease mainly characterized by keratinocyte hyperproliferation and massive infiltration of inflammatory immune cells. Acitretin (ACT), an FDA-approved first-line systemic drug for psoriasis treatment, could suppress the proliferation of keratinocytes and downregulate the expression of inflammatory cytokines by modulating signal transducer and activator of transcription (STAT) signaling pathways. However, dose-dependent side effects of ACT limit its long-term administration in the clinic. Therefore, improving the therapeutic efficacy of ACT to reduce clinical dosage will benefit the patients. Here, we develop ACT-conjugated dextran nanoparticles (ACT-Dex NPs) and evaluated the potential for psoriasis treatment. Our results indicate that ACT-Dex NPs ameliorate psoriasis-like skin disease significantly at a low dosage which does not cause side effects, while neat ACT drugs at an equivalent dosage provide much less benefit. Moreover, we demonstrate that ACT-Dex NPs suppress keratinocyte proliferation more efficiently than neat ACT by enhancing the inhibitory effect on STAT3 phosphorylation. Thus, the proposed ACT-Dex NPs provide an effective and safe option for psoriasis treatment.

Reductive Effect of Acitretin on Blood Glucose Levels in Chinese Patients With Psoriasis

Background: Psoriasis is a skin condition associated with increased risks of developing metabolic diseases, such as diabetes and hyperlipidaemia. Retinoid drugs, including acitretin, are commonly used to treat psoriasis due to its low cost and tolerable side effects.

Objective: This study aimed to explore the influence of acitretin on patients' metabolism levels, especially lipid and glucose.

Methods: In this retrospective study, a total of 685 psoriatic patients and 395 age/sex matched controls were enrolled. The demographic and biochemical indexes of each participant were recorded. Acitretin (30 mg/d) combined with the topical ointment calcipotriol was used to treat the psoriatic patients, and the glucose and lipid profiles of patients before and after acitretin treatment were analyzed.

Results: The blood glucose levels of 685 psoriasis patients were significantly higher than that of the control group (P < 0.001), while the blood lipid levels showed no difference between psoriatic patients and the matched controls. Triglyceride and low-density lipoprotein levels were significantly increased in 247 patients (P < 0.05) after 8 weeks of treatment with acitretin. Interestingly, there was a remarkable downward trend in body mass index (BMI) and blood glucose levels (P < 0.05) after acitretin treatment. Additionally, expression of both GLUT1 and GLUT4 in HaCaT and HepG2 cells were significantly increased when treated with acitretin. Compared to acitretin-free cells, the uptake of 2-NBDG was significantly higher in HaCaT and HepG2 cells after incubation with 5000 ng/mL acitretin for 36 h.

Conclusion: Acitretin plays a significant role of reducing the blood glucose level in psoriasis patients. The mechanism of lowering blood glucose may be through increasing glucose intake by cells, thereby reducing glucose levels in the peripheral blood.

Anti-Inflammatory Effects of Metabolites from Antarctic Fungal Strain Pleosporales sp. SF-7343 in HaCaT Human Keratinocytes

Chemical investigation of the Antarctic fungi Pleosporales sp. SF-7343 revealed four known secondary fungal metabolites: alternate C (1), altenusin (2), alternariol (3), and altenuene (4). The compound structures were identified primarily by NMR and MS analyses. Atopic dermatitis, an inflammatory disease, is driven by the abnormal activation of T helper (Th) 2 cells and barrier dysfunction. We attempted to identify the anti-inflammatory components of SF-7343. Initial screening showed that compounds 1 and 3 inhibited the secretion of interleukin-8 and -6 in tumor necrosis factor-α/interferon-γ-treated HaCaT cells, and these compounds also showed inhibitory effects on CCL5 and CCL22. Compounds 1 and 3 also downregulated the protein expression levels of intercellular adhesion molecule-1 and upregulated the expression of filaggrin and involcurin. The mechanism study results showed that compounds 1 and 3 inhibited nuclear translocation of nuclear factor-kappa B p65 and the phosphorylation of STAT1 and STAT3. Compound 1, but not compound 3, significantly promoted the expression of heme oxygenase (HO)-1. The effects of compound 1 were partly reversed by co-treatment with a HO-1 inhibitor, tin protoporphyrin IX. Taken together, this study demonstrates the potential value of Antarctic fungal strain SF-7343 isolates as a bioresource for bioactive compounds to prevent skin inflammation.

Role and mechanism of matrine alone and combined with acitretin for HaCaT cells and psoriasis-like murine models

BACKGROUND

Acitretin and matrine have been used in the treatment of psoriasis in China. This study was designed to investigate the role and related mechanisms of matrine alone and in combination with acitretin in the treatment of psoriasis in vitro and in vivo.

METHODS

HaCaT cells were treated with matrine at different concentrations of 0 (blank control), 0.2, 0.4, 0.8, and 1.6 mg/mL for 24, 48, 72 h, respectively. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium cell viability assay was used to assess the growth and proliferation of HaCaT cells. Cell cycle and apoptosis were detected by flow cytometry. Expression of protein was detected by Western blotting. Autophagy was observed by transmission electron microscopy. Then HaCaT cells were assigned to normal saline (NS) control group, matrine (0.4 mg/mL) group, acitretin (10 μmol/L) group, and matrine plus acitretin group, and the above methods were repeated. In animal experiments, the cumulative score (erythema, scaling, thickening) as a measure of the severity of inflammation was used to measure the skin performance of mice after treated with matrine 50 mg/kg, acitretin 4.5 mg/kg or combination of the two drugs on the psoriasis-like mouse models, respectively. Pathological findings of the lesions were observed, and the protein expressions in the lesions were detected by immunohistochemistry.

RESULTS

Cell proliferation inhibition was seen in HaCaT cells with treatment of matrine in a dose- and time-dependent manner (P < 0.01, respectively). Cell cycle G0/G1 phase arrest was observed in a dose-dependent way (P < 0.01). The expression of p21 (P < 0.05), LC3II/I (P < 0.01), and Beclin 1 (P < 0.01) increased and the expression of cyclin D1 (P < 0.05) decreased with increasing doses of matrine. Compared with the blank control, more autophagosomes were seen in HaCaT cells treated with matrine at 0.4 mg/mL by transmission electron microscopy (2.667 ± 1.202 vs. 21.33 ± 1.453, t = 9.899, P < 0.01). Cell proliferation inhibition and degree of the G0/G1 phase arrest was significantly higher in matrine plus acitretin group than those in matrine, acitretin, or the NS control group (P < 0.01, respectively). Compared with matrine or acitretin group, the expression of p21 (P < 0.05, P < 0.05) and LC3II/I (P < 0.01, P < 0.05) in matrine plus acitretin group increased significantly and the expression of cyclin D1 (P < 0.01, P < 0.05) and p62 (P < 0.05, P < 0.05) was reduced significantly. Compared with matrine or acitretin, matrine plus acitretin significantly down-regulated the phosphorylation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway (P < 0.05) and its downstream p-p70S6K (P < 0.05). In addition, the cumulative score of mice in the matrine plus acitretin group was significantly better than that in the matrine or acitretin group (1.480 ± 0.230 vs. 2.370 ± 0.241, P < 0.01; 1.480 ± 0.230 vs. 2.888 ± 0.341, P < 0.01). The expression of LC3 protein in the matrine plus acitretin group was also higher than that in the matrine, acitretin, or the NS control group (P < 0.05, respectively).

CONCLUSIONS

Matrine has therapeutic potentials for psoriasis. Matrine and acitretin show synergistic effect via cell cycle arrest and autophagy induction by PI3K/Akt/mTOR pathway.

The third-generation retinoid adapalene triggered DNA damage to induce S-phase arrest in HaCat cells

Epidermal proliferative diseases consisted of a series of common skin diseases, most of which were recurrent chronic skin diseases, and had greatly negative influence on the life quality of patient. Retinoids exhibited vital roles in the treatment of many skin diseases. Our recent study demonstrated that adapalene significantly inhibited the growth of HaCat cells, and the inhibitory activity was stronger than other retinoids, such as all-trans-retinoic acid, acitretin, isotretinoin, tazarotene, and bexarotene. Further study showed that adapalene suppressed the colony formation of HaCat cells, and it dramatically triggered S-phase arrest and apoptosis, rather than G1 phase arrest which was reported in other retinoids in several studies. Additionally, adapalene treatment greatly upregulated the protein expression of DNA damage marker γ-H2AX, which was in accord with the results of the elongation of tail moment by comet electrophoresis analysis. Moreover, DNA damage was triggered and DNA repair was suppressed synchronously with adapalene treatment, which accounted for the mechanism of S-phase arrest induced by adapalene. In summary, our recent work demonstrated that adapalene showed strong anti-proliferation activity in HaCat cells and could be an alternative agent for the epidermal proliferative disease.

IL-33 contributes to disease severity in Psoriasis-like models of mouse

Immune cells infiltrating the psoriatic skin secrete high amounts of pro-inflammatory cytokines IL-17, TNF-α, IL-21 and IL-36 resulting in chronic inflammation. However, the exact cellular and molecular mechanisms have not been fully understood. We report here elevation of IL-33 expression in psoriatic lesions. Studies in imiquimod (IMQ)-induced mice with psoriatic inflammation confirmed a critical role for IL-33 in driving the disease. IL-33 reduces the CD4⁺ and CD8⁺ cells, inhibits autophagy in IMQ-treated mouse skin, and promoted tyrosyl phosphorylation of STAT3. Thus, IL-33 appears to be a major risk factor for severity of psoriasis-like skin inflammation. Our findings may open new perspectives for understanding the mechanisms and developing a therapeutic strategy for psoriasis.

Effect of RNA Interference Targeting STAT3 Gene Combined with Ultrasonic Irradiation and SonoVue Microbubbles on Proliferation and Apoptosis in Keratinocytes of Psoriatic Lesions

Background

Signal transducer and activator of transcription 3 (STAT3) was strongly expressed and activated in psoriatic keratinocytes (KCs) and correlated with the severity of psoriasis. The study aimed to investigate the effects of STAT3 small interfering RNA (siRNA) combined with ultrasonic irradiation and SonoVue microbubbles on the proliferation and apoptosis in KCs of psoriatic lesions and the relative mechanisms.

Methods

Psoriatic KCs were transfected under four experimental conditions: (1) STAT3 siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (LUS group); (2) STAT3 siRNA only carried by Lipofectamine 3000 (L group); (3) the negative control of siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (siRNA-NC); (4) not treated as Blank. Cell Counting Kit-8 assay was used to evaluate the cell proliferation. Cell cycle analysis was detected with cycle test Plus DNA reagent kit associated with flow cytometer. FITC Annexin V apoptosis detection kit associated with flow cytometer was applied for apoptosis analysis. Fluo calcium indicator associated with flow cytometer was used to analyze intracellular free calcium concentration ([Ca²⁺]_i). The expressions of cyclin D1 and Bcl-xL were detected both at the mRNA level by real-time reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level by Western blotting. The obtained data were statistically evaluated by two-way analysis of variance.

Results

STAT3 siRNA inhibited the growth of KCs in a time-dependent manner showing the highest proliferation inhibition in LUS group with proliferation ratio of 45.38% ± 5.85% at 72h (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced an altered cell cycle distribution of KCs showing the highest increases in G2/M-phase population up to 18.06% ± 0.36% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced late apoptosis of KCs with the highest late apoptosis percentage of 22.87% ± 1.28% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the elevation of [Ca²⁺]_iof KCs with the highest calcium fluorescence intensity mean of 1213.67 ± 60.51 in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the downregulation of cyclin D1 and Bcl-xL expressions of KCs at mRNA and protein levels with the lowest expressions in LUS group with cyclin D1 expression of 51.81% ± 9.58% and 70.17% ± 4.22% at mRNA level and at protein level, respectively, and with Bcl-xL expression of 37.58% ± 4.92% and 64.06% ± 7.78% at mRNA level and at protein level, respectively (P < 0.05 vs. L group, siRNA-NC, or Blank).

Conclusions

STAT3 siRNA inhibited the growth and induced the apoptosis in psoriatic KCs likely partly through altering cell cycle distribution, elevating [Ca²⁺]_i, and downregulating cyclin D1 and Bcl-xL expressions. Silencing the target gene STAT3 in psoriatic KCs with siRNA combined with ultrasonic irradiation and microbubbles would contribute to a significant innovation as a new clinical therapy for psoriasis.

Pharmacokinetics of tazarotene and acitretin in psoriasis

INTRODUCTION

Psoriasis is a prevalent cutaneous condition with severe physical and psychological manifestations. Since the advent of biologics, clinical outcomes in psoriasis have improved. However, retinoids are useful in the correct clinical context. Tazarotene and acitretin are currently the only US Food and Drug Administration approved retinoids for treatment of psoriasis. Both topical tazarotene and oral acitretin act on retinoic acid receptors and retinoid-X-receptors, resulting in altered gene expression of inflammatory cytokines and inhibition of keratinocyte proliferation. Areas covered: This article provides an in-depth pharmacologic and clinical review on the use of tazarotene and acitretin in psoriasis. The PubMed database was searched using combinations of keywords: acitretin, bioavailability, dosing, efficacy, etretinate, interactions, mechanism, pharmacodynamics, pharmacokinetics, pharmacogenetics, psoriasis, safety, tazarotene, tolerability, and toxicity. Expert opinion: Tazarotene and acitretin are effective treatments for psoriasis. Benefits include lack of immunosuppression and success treating inflammatory psoriasis. When combined with other topical and systemic agents, both retinoids improve clinical efficacy while lowering the treatment threshold. However, topical adherence and bothersome side effects can limit retinoid use. Acitretin and tazarotene both improve outcomes through a unique mechanism that especially benefits subsets of patients, despite side effects and limitations.

T helper 17 cell/regulatory T-cell imbalance in hidradenitis suppurativa/acne inversa: the link to hair follicle dissection, obesity, smoking and autoimmune comorbidities

BACKGROUND

Disintegration of the infundibula of terminal hair follicles (HFs) in intertriginous skin areas exhibits the histological hallmark of hidradenitis suppurativa (HS)/acne inversa, featuring a dissecting terminal hair folliculitis. Elevated serum levels of interleukin (IL)-17 and local increase in the ratio of proinflammatory T helper (Th)17 cells and anti-inflammatory regulatory T cells (Tregs) have been reported. Perifollicular Tregs play a key role in HF stem cell homeostasis and infundibular integrity.

OBJECTIVES

In this review, we evaluate the Th17/Treg ratio in HS, its aggravating conditions and associated comorbidities. Furthermore, we intended to clarify whether drugs with reported beneficial effects in the treatment of HS readjust the deviated Th17/Treg axis.

METHODS

PubMed-listed, peer-reviewed original research articles characterizing Th17/Treg regulation in HS/acne inversa and associated comorbidities were selected for this review.

RESULTS

This review presents HS as a disease that exhibits an increased Th17/Treg ratio. Perifollicular deficiencies in Treg numbers or function may disturb HF stem cell homeostasis, initiating infundibular dissection of terminal HFs and perifollicular inflammation. The Th17/Treg imbalance is aggravated by obesity, smoking and decreased Notch signalling. In addition, HS-associated autoimmune diseases exhibit a disturbed Th17/Treg axis resulting in a Th17-dominant state. All drugs that have beneficial effects in the treatment of HS normalize the Th17/Treg ratio.

CONCLUSIONS

HS immunopathogenesis is closely related to deviations of the Th17/Treg balance, which may negatively affect Treg-controlled HF stem cell homeostasis and infundibular integrity. Pharmacological intervention should not only attenuate Th17/IL-17 signalling, but should also improve Treg function in order to stabilize HF stem cell homeostasis and infundibular integrity.

Combined Transcriptomic Analysis Revealed AKR1B10 Played an Important Role in Psoriasis through the Dysregulated Lipid Pathway and Overproliferation of Keratinocyte

RNA-seq has enabled in-depth analysis of the pathogenesis of psoriasis on the transcriptomic level, and many biomarkers have been discovered to be related to the immune response, lipid metabolism, and keratinocyte proliferation. However, few studies have combined analysis from various datasets. In this study, we integrated different psoriasis RNA-seq datasets to reveal the pathogenesis of psoriasis through the analysis of differentially expressed genes (DEGs), pathway analysis, and functional annotation. The revealed biomarkers were further validated through proliferation phenotypes. The results showed that DEGs were functionally related to lipid metabolism and keratinocyte differentiation dysregulation. The results also showed new biomarkers, such as AKR1B10 and PLA2G gene families, as well as pathways that include the PPAR signaling pathway, cytokine-cytokine receptor interaction, alpha-linoleic acid metabolism, and glycosphingolipid biosynthesis. Using siRNA knockdown assays, we further validated the role that the AKR1B10 gene plays in proliferation. Our study demonstrated not only the dysfunction of the AKR1B10 gene in lipid metabolizing but also its important role in the overproliferation and migration of keratinocyte, which provided evidence for further therapeutic uses for psoriasis.