Dual targeting of mTOR/IL-17A and autophagy by fisetin alleviates psoriasis-like skin inflammation

Effect of anti-inflammatory molecules from food on organoids derived from adenomatous polyps of FAP subjects

INTRODUCTION

Individuals with Familial Adenomatous Polyposis (FAP) or APC-associated polyposis, an autosomal dominant inherited condition, develop multiple adenomatous polyps and have an increased colorectal cancer (CRC) risk. A change in diet can help reduce cancer risk, and several dietary components have an antitumor effect. We aimed to evaluate the potential of the anti-inflammatory and anticancer substances quercetin (QER), epigallocatechin gallate (EGG) and fisetin (FIS) in decreasing the risk of CRC by reducing the growth of polyps in an organoid model.

METHODS

Patient-derived organoid (PDO) lines were generated from polyps obtained from patients with FAP undergoing prophylactic colectomy. PDOs were treated with QER, EGG, or FIS to determine their effect on cell growth. Changes in caspase 3/7 activity and expression of inflammation and apoptosis mediators were assessed by luminescent and colorimetric assays.

RESULTS

Three PDO lines with different inactivating pathogenic variants in the APC gene were developed using a combinatorial approach. FIS was the most active of the three substances tested, presenting the lowest IC50 in all PDO lines (range: 42.6-9.2 uM). The IC50 was defined as the concentration required to halve the number of cells after 72 hours. All molecules tested induced apoptosis through activation of caspases 3/7.

CONCLUSIONS

QER, EGG, and FIS can be easily taken from foods or dietary supplements, show toxicity on PDOs derived from adenomatous polyps, while they are known to be harmless on normal cells. Diets enriched with these substances could be potential supplemental treatments to reduce the risk of CRC in individuals with FAP.

Unveiling ferroptosis: a new frontier in skin disease research

Ferroptosis, a form of regulated cell death distinct from apoptosis, necrosis, and autophagy, is increasingly recognized for its role in skin disease pathology. Characterized by iron accumulation and lipid peroxidation, ferroptosis has been implicated in the progression of various skin conditions, including psoriasis, photosensitive dermatitis, and melanoma. This review provides an in-depth analysis of the molecular mechanisms underlying ferroptosis and compares its cellular effects with other forms of cell death in the context of skin health and disease. We systematically examine the role of ferroptosis in five specific skin diseases, including ichthyosis, psoriasis, polymorphous light eruption (PMLE), vitiligo, and melanoma, detailing its influence on disease pathogenesis and progression. Moreover, we explore the current clinical landscape of ferroptosis-targeted therapies, discussing their potential in managing and treating skin diseases. Our aim is to shed light on the therapeutic potential of modulating ferroptosis in skin disease research and practice.

Unlocking milk thistle's anti-psoriatic potential in mice: Targeting PI3K/AKT/mTOR and KEAP1/NRF2/NF-κB pathways to modulate inflammation and oxidative stress

Silybum marianum, known as milk thistle (MT), is traditionally used to manage liver diseases. This study aimed to investigate the role of MT extract topical application as a potential treatment for imiquimod (IMQ)-induced psoriatic lesions in mice with particular emphasis on phosphoinositol-3 Kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) and Kelch-like ECH-associated protein 1 (KEAP1)/ nuclear factor erythroid-2-related factor (NRF2)/ nuclear factor-kappa B (NF-κB) molecular cascades involvement. To address this aim, forty male Swiss albino mice were subdivided into four groups (n = 10 mice/group): control, IMQ model, standard group where mice were treated topically with IMQ, then the anti-psoriatic mometasone cream, and MT extract-treated group where mice were treated topically with IMQ followed by MT extract. In most measured parameters, MT extract, rich in silymarin, exhibited potent anti-psoriatic activity comparable to the standard cortisone treatment. MT extract mitigated dorsal skin erythema, scaling, and epidermal thickening, reflected by lowering the Psoriasis Area Severity Index (PASI) score. Moreover, it alleviated IMQ-induced splenomegaly. Mechanistically, the PI3K/AKT/mTOR pathway was the main functional pathway behind such improvements, where it was significantly inhibited by MT extract application. This led to NRF2 activation via KEAP1 downregulation with subsequent anti-inflammatory effect proven by reducing NF-κB, interleukin (IL)-23, and IL-17A and antioxidant ability proven by boosting the antioxidant glutathione and heme oxygenase-1. Such improvements were confirmed by alleviating the histopathological alteration. Thus, MT extract could be a promising therapeutic agent for psoriasis treatment by inhibiting PI3K/AKT/mTOR cascade, along with NRF2 signaling activation.

Rice Husk Silica Liquid Enhances Autophagy and Reduces Overactive Immune Responses via TLR-7 Signaling in Lupus-Prone Models

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by widespread inflammation and multi-organ damage. Toll-like receptor 7 (TLR-7) and autophagy have been implicated in SLE pathogenesis. Rice husk silica liquid (RHSL) has shown potential for modulating inflammatory responses, but its effects on SLE have not been thoroughly investigated. This study aims to evaluate the impact of RHSL on immune responses and autophagy in cell culture experiments, focusing on its effects on TLR-7 signaling, cytokine production, and autophagy modulation. RAW264.7 cells and human peripheral blood mononuclear cells (PBMCs) from healthy donors and SLE patients were used. Cells were stimulated with LPS or TLR-7 agonists and treated with RHSL. Cell viability was assessed, and cytokine levels (TNF-α and IL-6) were measured by ELISA. Autophagy-related proteins (LC3II, ATG5-ATG12) were analyzed by Western blotting. The effect of autophagy inhibition was studied using 3-methyladenine (3-MA). A concentration of 100 μg/mL RHSL did not affect cell viability but significantly reduced the TNF-α production in TLR-7 agonist-stimulated RAW264.7 cells (compared to TLR-7 alone, 3.41 ± 0.54 vs. 6.72 ± 0.07 folds) and PBMCs (compared to TLR-7 alone, 0.97 ± 0.19 vs. 1.40 ± 0.33 folds). RHSL enhanced autophagy, as evidenced by increased LC3II (4.35 ± 1.08 folds) and ATG5-ATG12 (7.07 ± 1.30 folds) conjugation in both RAW264.7 cells and SLE patient-derived PBMCs. The reduction in TNF-α production by RHSL was attenuated by 3-MA, indicating that autophagy plays a role in this process. RHSL also inhibited the translocation of phosphorylated NF-κB into the nucleus, suggesting a mechanism for its anti-inflammatory effects. RHSL exhibits potential as an immunomodulatory agent in SLE by enhancing autophagy and modulating TLR-7 signaling pathways. These findings suggest that RHSL could offer therapeutic benefits for managing inflammatory responses in SLE and warrant further investigation into its clinical applications.

Exploring the role of autophagy in psoriasis pathogenesis: Insights into sustained inflammation and dysfunctional keratinocyte differentiation

Psoriasis is a common and prevalent chronic papulosquamous cutaneous disorder characterized by sustained inflammation, uncontrolled keratinocyte proliferation, dysfunctional differentiation, and angiogenesis. Autophagy, an intracellular catabolic process, can be induced in response to nutrient stress. It entails the degradation of cellular constituents through the lysosomal machinery, and its association with psoriasis has been well-documented. Nevertheless, there remains a notable dearth of research concerning the involvement of autophagy in the pathogenesis of psoriasis within human skin. This review provides a comprehensive overview of autophagy in psoriasis pathogenesis, focusing on its involvement in two key pathological manifestations: sustained inflammation and uncontrolled keratinocyte proliferation and differentiation. Additionally, it discusses potential avenues for disease management.

Pivotal Role of mTOR in Non-Skin Manifestations of Psoriasis

Psoriasis is a chronic inflammatory condition affecting 2% of the Western population. It includes diverse manifestations influenced by genetic predisposition, environmental factors, and immune status. The sustained activation of mTOR is a key element in psoriasis pathogenesis, leading to an uncontrolled proliferation of cytokines. Furthermore, mTOR activation has been linked with the transition from psoriasis to non-skin manifestations such as psoriatic arthritis and cardiovascular events. While therapies targeting pro-inflammatory cytokines have shown efficacy, additional pathways may offer therapeutic potential. The PI3K/Akt/mTOR pathway, known for its role in cell growth, proliferation, and metabolism, has emerged as a potential therapeutic target in psoriasis. This review explores the relevance of mTOR in psoriasis pathophysiology, focusing on its involvement in cutaneous and atheromatous plaque proliferation, psoriatic arthritis, and cardiovascular disease. The activation of mTOR promotes keratinocyte and synovial cell proliferation, contributing to plaque formation and joint inflammation. Moreover, mTOR activation may exacerbate the cardiovascular risk by promoting pro-inflammatory cytokine production and dysregulation lipid and glucose metabolism. The inhibition of mTOR has shown promise in preclinical studies, reducing skin inflammation and plaque proliferation. Furthermore, mTOR inhibition may mitigate cardiovascular risk by modulating cholesterol metabolism and attenuating atherosclerosis progression. Understanding the role of mTOR in psoriasis, psoriatic arthritis, and cardiovascular disease provides insight into the potential treatment avenues and sheds light on the complex interplay of the immune and metabolic pathways in these conditions.

The link between autophagy and psoriasis

Autophagy is a lysosome-dependent, self-renewal mechanism that degrades and recycles cellular components in eukaryotic cells to maintain the homeostasis of the intracellular environment. Psoriasis is featured by increased inflammatory response, epidermal hyperproliferation and abnormal differentiation, infiltration of immune cells and increased expression levels of both endothelial adhesion molecules and angiogenic mediators. Evidence indicates that autophagy has important roles in many different types of cells, such as lymphocytes, keratinocytes, monocytes and mesenchymal stem cells (MSCs). This paper will review the role of autophagy in the pathogenesis of psoriasis and strategies for therapeutic modulation. Key Message Autophagy regulates the functions of cutaneous cells (MSCs, KCs, T cells and endothelial cells). Since reduced autophagy contributes in part to the pathogenesis of psoriasis, enhancement of autophagy can be an alternative approach to mitigate psoriasis.

Daturataturin A Ameliorates Psoriasis by Regulating PPAR Pathway

Psoriasis is a kind of severe immune-mediated systemic skin disorder, becoming a worldwide public health concern. Daturataturin A (DTA), a withanolide compound, exerts excellent anti-inflammatory and anti-proliferative properties. The objective of this study is to elucidate the effect of DTA on psoriasis and its potential mechanism. We established psoriasis-like keratinocytes model by stimulating HaCaT cells with M5 cocktail cytokines including Interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α), followed by intervention with DTA. The potential effects and mechanisms of DTA on psoriasis were evaluated in vitro. DTA was found to be able to inhibit hyperproliferation, promote apoptosis, decrease the release of pro-inflammatory cytokines, downregulate keratin expression, and improve lipid metabolism via regulating the peroxisome proliferator-activated receptor (PPAR) signaling pathway by M5 cocktail cytokines stimulation in HaCaT cells. DTA ameliorated lipid metabolism of psoriasis and exerted the potential anti-psoriasis effects by regulating PPAR pathway in vitro, suggesting that DTA may act as a new therapeutic agent for psoriasis.

Resistin - A Plausible Therapeutic Target in the Pathogenesis of Psoriasis

Resistin, a cytokine hormone predominantly secreted by adipose tissue, is elevated in various metabolic disorders such as obesity, type 2 diabetes, and cardiovascular disease. In addition to its involvement in metabolic regulation, resistin has been implicated in the pathogenesis of psoriasis, a chronic inflammatory skin disorder. Numerous studies have reported increased resistin levels in psoriatic skin lesions, suggesting a possible association between resistin and psoriasis. Recent studies have suggested the potential involvement of resistin in the development and progression of certain cancers. Resistin is overexpressed in breast, colorectal, and gastric cancers. This suggests that it may play a role in the development of these cancers, possibly by inducing inflammation and cell growth. The link between resistin and cancer raises the possibility of shared underlying mechanisms driving the pathogenesis of psoriasis. Chronic inflammation, one such mechanism, is a hallmark of psoriasis and cancer. Further research is needed to fully understand the relationship between resistin and psoriasis. Identifying potential therapeutic targets is crucial for effective management of psoriasis. By doing so, we may be able to develop more effective treatment options for individuals living with psoriasis and ultimately improve their quality of life. Ultimately, a more comprehensive understanding of the mechanisms underlying the impact of resistin on psoriasis is essential for advancing our knowledge and finding new ways to treat and manage this challenging condition.

IL-17A Orchestrates Reactive Oxygen Species/HIF1α-Mediated Metabolic Reprogramming in Psoriasis

Immune cell-derived IL-17A is one of the key pathogenic cytokines in psoriasis, an immunometabolic disorder. Although IL-17A is an established regulator of cutaneous immune cell biology, its functional and metabolic effects on nonimmune cells of the skin, particularly keratinocytes, have not been comprehensively explored. Using multiomics profiling and systems biology-based approaches, we systematically uncover significant roles for IL-17A in the metabolic reprogramming of human primary keratinocytes (HPKs). High-throughput liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance spectroscopy revealed IL-17A-dependent regulation of multiple HPK proteins and metabolites of carbohydrate and lipid metabolism. Systems-level MitoCore modeling using flux-balance analysis identified IL-17A-mediated increases in HPK glycolysis, glutaminolysis, and lipid uptake, which were validated using biochemical cell-based assays and stable isotope-resolved metabolomics. IL-17A treatment triggered downstream mitochondrial reactive oxygen species and HIF1α expression and resultant HPK proliferation, consistent with the observed elevation of these downstream effectors in the epidermis of patients with psoriasis. Pharmacological inhibition of HIF1α or reactive oxygen species reversed IL-17A-mediated glycolysis, glutaminolysis, lipid uptake, and HPK hyperproliferation. These results identify keratinocytes as important target cells of IL-17A and reveal its involvement in multiple downstream metabolic reprogramming pathways in human skin.

Galgravin Isolated from Piper kadsura Ameliorates Lipopolysaccharide (LPS)-Induced Endotoxemia in Mice

Sepsis results from uncontrolled inflammation, characterized by cytokine storm and immunoparalysis. To assess whether galgravin, a natural lignan isolated from Piper kadsura, can be used to treat sepsis, models of bacterial lipopolysaccharide (LPS)-activated macrophages and LPS-induced endotoxemia mice were used. Galgravin suppressed NF-κB activation in LPS-activated RAW 264.7 macrophages without causing significant cytotoxicity, in which proinflammatory molecules like TNF-α, IL-6, iNOS, and COX-2 were downregulated. In addition, the expression of TNF-α and IL-6 was also suppressed by galgravin in LPS-activated murine bone marrow-derived macrophages. Moreover, galgravin significantly downregulated the mRNA expression of TNF-α, IL-6, and iNOS in the lungs and decreased TNF-α and IL-6 in the serum and IL-6 in the bronchoalveolar lavage fluid of LPS-challenged mice. The COX-2 expression in tissues, including the lung, liver, and kidney, as well as the lung alveolar hemorrhage, was also reduced by galgravin. The present study reveals the anti-inflammatory effects of galgravin in mouse models and implies its potential application in inflammation diseases.