Psoriasis: Interplay between dysbiosis and host immune system

Advances in the mechanism of action of short-chain fatty acids in psoriasis

Psoriasis is a prevalent chronic inflammatory and immunological disorder. Its lesions are present as scaly erythema or plaques. Disruptions in the body's immune system play a significant role in developing psoriasis. Recent evidence suggests a potential role of the gut microbiome in autoimmune diseases. Short-chain fatty acids (SCFAs) are the primary metabolites created by gut microbes and play a crucial fuction in autoimmunity. SCFAs act on various cells by mediating signaling to participate in host physiological and pathological processes. These processes encompass body metabolism, maintenance of intestinal barrier function, and immune system modulation. SCFAs can regulate immune cells to enhance the body's immune function, potentially influencing the prevention and treatment of psoriasis. However, the mechanisms underlying the role of SCFAs in psoriasis remain incompletely understood. This paper examines the relationship between SCFAs and psoriasis, elucidating how SCFAs influence the immune system, inflammatory response, and gut barrier in psoriasis. According to the study, in psoriasis, SCFAs have been shown to regulate neutrophils, macrophages, and dendritic cells in the adaptive immune system, as well as T and B cells in the innate immune system. Additionally, we explore the role of SCFAs in psoriasis by maintaining intestinal barrier function, restoring intestinal ecological homeostasis, and investigating the potential therapeutic benefits of SCFAs for psoriasis.

The alleviative effects of canagliflozin on imiquimod-induced mouse model of psoriasis-like inflammation

Psoriasis is a life-long immune-mediated dermatosis with thickened, reddish, and flaky skin patches. Canagliflozin is a gliflozin antidiabetic with non-classical remarkable antioxidative, anti-inflammatory, anti-proliferative, and immune-modulating effects. The aim of this study is to examine the probable effects of topical canagliflozin on a mouse model of imiquimod-provoked psoriasis-like dermatitis. The study evaluated 20 Swiss white mice, sorted haphazardly into 4 groups of 5 animals each. Every mouse, with the exception of the control group, had imiquimod applied topically to their shaved backs for 7 days. The control group included healthy mice that were not given any treatment. Mice in the other three groups underwent topical treatment with vehicle (induction group), 0.05% clobetasol propionate ointment (clobetasol group), or 4% canagliflozin emulgel (canagliflozin 4% group) on exactly the same day as imiquimod cream was administered. Topical canagliflozin markedly lowered the intensity of imiquimod-provoked psoriasis eruptions, featuring redness, glossy-white scales, and acanthosis, while also correcting histopathological aberrations. Canagliflozin administration to imiquimod-exposed animals resulted in significantly decreased cutaneous concentrations of inflammatory mediators such as IL-8, IL-17, IL-23, and TNF-α, with raised levels of IL-10. Canagliflozin further lowered proliferative factors involving Ki-67 and PCNA, diminished oxidative indicators such as MDA and MPO, and augmented the activity of antioxidant markers, notably SOD and CAT. Canagliflozin might alleviate the imiquimod-induced animal model of psoriasis, probably thanks to its profound anti-inflammatory, antioxidant, antiangiogenic, and antiproliferative activities.

Gut microbiota and psoriasis: pathogenesis, targeted therapy, and future directions

Background

Psoriasis is one of the most common autoimmune skin diseases. Increasing evidence shows that alterations in the diversity and function of microbiota can participate in the pathogenesis of psoriasis through various pathways and mechanisms.

Objective

To review the connection between microbial changes and psoriasis, how microbial-targeted therapy can be used to treat psoriasis, as well as the potential of prebiotics, probiotics, synbiotics, fecal microbiota transplantation, diet, and Traditional Chinese Medicine as supplementary and adjunctive therapies.

Methods

Literature related to the relationship between psoriasis and gut microbiota was searched in PubMed and CNKI.

Results

Adjunct therapies such as dietary interventions, traditional Chinese medicine, and probiotics can enhance gut microbiota abundance and diversity in patients with psoriasis. These therapies stimulate immune mediators including IL-23, IL-17, IL-22, and modulate gamma interferon (IFN-γ) along with the NF-kB pathway, thereby suppressing the release of pro-inflammatory cytokines and ameliorating systemic inflammatory conditions.

Conclusion

This article discusses the direction of future research and clinical treatment of psoriasis from the perspective of intestinal microbiota and the mechanism of traditional Chinese medicine, so as to provide clinicians with more comprehensive diagnosis and treatment options and bring greater hope to patients with psoriasis.

Phenylalanine Butyramide: A Butyrate Derivative as a Novel Inhibitor of Tyrosinase

Metabolites resulting from the bacterial fermentation of dietary fibers, such as short-chain fatty acids, especially butyrate, play important roles in maintaining gut health and regulating various biological effects in the skin. However, butyrate is underutilized due to its unpleasant odor. To circumvent this organoleptic unfavorable property, phenylalanine butyramide (PBA), a butyrate precursor, has been synthesized and is currently available on the market. We evaluated the inhibition of mushroom tyrosinase by butyrate and PBA through in vitro assays, finding IC50 values of 34.7 mM and 120.3 mM, respectively. Docking calculations using a homology model of human tyrosinase identified a putative binding mode of PBA into the catalytic site. The anti-aging and anti-spot efficacy of topical PBA was evaluated in a randomized, double-blind, parallel-arm, placebo-controlled clinical trial involving 43 women affected by photo-damage. The results of this study showed that PBA significantly improved skin conditions compared to the placebo and was well tolerated. Specifically, PBA demonstrated strong skin depigmenting activity on both UV and brown spots (UV: -12.7% and -9.9%, Bs: -20.8% and -17.7% after 15 and 30 days, respectively, p < 0.001). Moreover, PBA brightened and lightened the skin (ITA°: +12% and 13% after 15 and 30 days, respectively, p < 0.001). Finally, PBA significantly improved skin elasticity (Ua/Uf: +12.4% and +32.3% after 15 and 30 days, respectively, p < 0.001) and firmness (Uf: -3.2% and -14.9% after 15 and 30 days, respectively, p < 0.01).

Atopic Dermatitis and Psoriasis: Similarities and Differences in Metabolism and Microbiome

Atopic dermatitis and psoriasis are common chronic inflammatory diseases of high incidence that share some clinical features, including symptoms of pruritus and pain, scaly lesions, and histologically, acanthosis and hyperkeratosis. Meanwhile, they are both commonly comorbid with metabolic disorders such as obesity and diabetes, indicating that both diseases may exist with significant metabolic disturbances. Metabolomics reveals that both atopic dermatitis and psoriasis have abnormalities in a variety of metabolites, including lipids, amino acids, and glucose. Meanwhile, recent studies have highlighted the importance of the microbiome and its metabolites in the pathogenesis of atopic dermatitis and psoriasis. Metabolic alterations and microbiome dysbiosis can also affect the immune, inflammatory, and epidermal barrier, thereby influencing the development of atopic dermatitis and psoriasis. Focusing on the metabolic and microbiome levels, this review is devoted to elaborating the similarities and differences between atopic dermatitis and psoriasis, thus providing insights into the intricate relationship between both conditions.

The Impact of Shared Assistance between Dermatology and Internal Medicine on Patients with Psoriasis

Background: The care of psoriatic patients requires a multidisciplinary approach that addresses not only skin involvement but also cardiovascular risk factors. Coordination between dermatology and internal medicine departments, with a specific focus on treatment and long-term follow-up, can substantially improve the course of a disease and its associated complications. Objective: to evaluate the effects of the holistic management of patients with psoriasis by a multidisciplinary team consisting of dermatology and internal medicine specialists. Methods: We conducted an observational, prospective, single-center case-control study between October 2016 and December 2019 in San Jorge University Hospital (Huesca, Spain). Cases included patients undergoing follow-up in the combined dermatology and internal medicine clinic. The control group consisted of an equivalent number of randomly selected, age- and sex-matched patients with moderate-to-severe psoriasis who were seen in the general dermatology department of the same hospital during the same time period. Main outcomes and measures: The primary outcome was the control of psoriatic disease and cardiovascular risk factors such as weight, blood pressure, waist circumference, body mass index (BMI), SCORE index (Systematic Coronary Risk Evaluation), and blood test parameters, as well as diet, physical exercise, and habits such as tobacco and alcohol consumption. To compare data collected over time, data were grouped into three time periods: baseline (t1), intermediate (t2), and final (t3). Results: The case group consisted of 27 patients, and the control group consisted of 25 patients. Multivariate analysis was used to evaluate the relationship between the 10-year risk of experiencing a cardiovascular event (SCORE) and the clinical characteristics and analytical variables of patients with psoriasis and controls (n = 52). The variables that were significantly associated with a higher 10-year risk of experiencing a cardiovascular event were age (OR, 1.33; CI95% 1.21-1.50; p < 0.001); smoking (OR, 5.05, CI95% 1.07-27.37; p = 0.047); PASI (OR, 7.98, CI95% 2.32-35.86; p = 0.003); BSA (OR, 1.22, CI95% 1.01-1.49; p = 0.044); and being a control patient (OR, 3.26; CI95% 0.84-13.56; p = 0.029). Conclusions: Pharmacological and behavioral interventions carried out as part of the procedure of the multidisciplinary clinic resulted in improvements in the following variables relative to the control group: PASI, BSA, DLQI, PSOLIFE, lipid profile, insulin and HOMA-IR GGT levels, vitamin D levels, and SCORE. These findings indicate the beneficial effect of the multidisciplinary clinic, which reduced the risk of cardiovascular events in psoriatic patients with metabolic comorbidities.

The high expression of TOP2A and MELK induces the occurrence of psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease. However, the influence of the TOP2A and MELK genes on psoriasis remains unclear.

METHODS

Psoriasis datasets GSE166388 and GSE181318 were downloaded from the Gene Expression Omnibus (GEO) database generated from GPL570 and GPL22120. Differential gene expression (DEGs) was identified. Functional enrichment analysis, gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and immune infiltration analysis were conducted. The protein-protein interaction (PPI) network was constructed and analyzed. Gene expression heat map was generated. The most relevant diseases associated with core genes were determined through comparison with the Comparative Toxicogenomics Database (CTD) website. TargetScan was used to select miRNAs regulating central DEGs.

RESULTS

A total of 773 DEGs were identified. According to Gene Ontology (GO) analysis, they were mainly enriched in mitochondrial gene expression, oxidative phosphorylation, mitochondrial envelope, mitochondria and ribosome. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that target cells were mainly enriched in metabolic pathways, proteasome, and oxidative phosphorylation. Seven core genes (TOP2A, NUF2, MELK, ASPM, DLGAP5, CCNA2, DEPDC1B) were obtained. The gene expression heatmap showed high expression of core genes (TOP2A, MELK) in psoriasis samples, while DEPDC1B, CCNA2, DLGAP5, NUF2, ASPM were lowly expressed in psoriasis samples. CTD analysis found that TOP2A and MELK were related to skin neoplasms, skin diseases, psoriasis, erythema, dermatitis, and infections.

CONCLUSION

TOP2A and MELK genes are highly expressed in psoriasis, and higher expression of TOP2A and MELK genes is associated with poorer prognosis.

The Use of Microbial Modifying Therapies to Prevent Psoriasis Exacerbation and Associated Cardiovascular Comorbidity

Psoriasis has emerged as a systemic disease characterized by skin and joint manifestations as well as systemic inflammation and cardiovascular comorbidities. Many progresses have been made in the comprehension of the immunological mechanisms involved in the exacerbation of psoriatic plaques, and initial studies have investigated the mechanisms that lead to extracutaneous disease manifestations, including endothelial disfunction and cardiovascular disease. In the past decade, the involvement of gut dysbiosis in the development of pathologies with inflammatory and autoimmune basis has clearly emerged. More recently, a major role for the skin microbiota in establishing the immunological tolerance in early life and as a source of antigens leading to cross-reactive responses towards self-antigens in adult life has also been evidenced. Gut microbiota can indeed be involved in shaping the immune and inflammatory response at systemic level and in fueling inflammation in the cutaneous and vascular compartments. Here, we summarized the microbiota-mediated mechanisms that, in the skin and gut, may promote and modulate local or systemic inflammation involved in psoriatic disease and endothelial dysfunction. We also analyze the emerging strategies for correcting dysbiosis or modulating skin and gut microbiota composition to integrate systemically existing pharmacological therapies for psoriatic disease. The possibility of merging systemic treatment and tailored microbial modifying therapies could increase the efficacy of the current treatments and potentially lower the effect on patient's life quality.

Pathological and Therapeutical Implications of Pyroptosis in Psoriasis and Hidradenitis Suppurativa: A Narrative Review

This manuscript explores the role of pyroptosis, an inflammatory programmed cell death, in the pathogenesis of two chronic dermatoses, psoriasis and hidradenitis suppurativa (HS). The diseases, though clinically diverse, share common pathogenetic pathways involving the unbalanced interaction between the adaptive and innate immune systems. This review focuses on the molecular changes in psoriatic and HS skin, emphasizing the activation of dendritic cells, secretion of interleukins (IL-17, IL-22, and TNF-α), and the involvement of inflammasomes, particularly NLRP3. This manuscript discusses the role of caspases, especially caspase-1, in driving pyroptosis and highlights the family of gasdermins (GSDMs) as key players in the formation of pores leading to cell rupture and the release of proinflammatory signals. This study delves into the potential therapeutic implications of targeting pyroptosis in psoriasis and HS, examining existing medications like biologics and Janus kinase inhibitors. It also reviews the current limitations and challenges in developing therapies that selectively target pyroptosis. Additionally, the manuscript explores the role of pyroptosis in various inflammatory disorders associated with psoriasis and HS, such as inflammatory bowel disease, diabetes mellitus, and cardiovascular disorders. The review concludes by emphasizing the need for further research to fully elucidate the pathomechanisms of these dermatoses and develop effective, targeted therapies.

Human metabolism and body composition: prospects for novel studies

CONTEXT

Most articles on gut microbiota argue the importance of body composition assessment in patients; however, body composition assessments are fragile (ie, with methodological limitations) in the most recent studies.

OBJECTIVE

To present two suggestions for further research using the human body composition assessment.

METHODS

The methods used in this study are based on a Pinto et al article published in Nutrition Reviews.

DATA EXTRACTION

On the basis of data.

obtained from the PubMed, SCOPUS, LILACS, and Web of Science databases, Pinto et al provided a current survey of intermittent fasting protocols and an understanding of the outcomes to date in terms of the profile of the intestinal microbiota in obese organisms.

DATA ANALYSIS

Of the 82 original articles identified from the databases, 35 were eliminated because of duplication and 32 were excluded for not meeting the inclusion criteria. Two additional articles found in a new search were added, yielding a total of 17 studies to be included in this review. Among the protocols, alternate-day fasting and time-restricted feeding were the most common, and they were shown to have different mechanisms of metabolic signaling. Time-restricted feeding influences body mass control and biochemical parameters by regulating the circadian system and improving satiety control systems by acting on leptin secretion. In contrast, alternate-day fasting leads to a reduction of ±75% of all energy consumption regardless of dietary composition, in addition to promoting hormonal adjustments that promote body mass control. Furthermore, both protocols could remodel the intestinal microbiota by changing the Firmicutes to Bacteroidetes ratio and increasing the abundance of strains such as Lactobacillus spp. and Akkermansia that have a protective effect on metabolism against the effects of body mass gain.

CONCLUSION

Changes in adipose tissue (eg, body mass loss, control, gain) should be interpreted via the sum of skinfolds in absolute values, waist perimeter, and patients' body proportionality, because fat is just a fraction of the adipocyte (lipid).

Metatranscriptomic insight into the possible role of clay microbiome in skin disease management

Even though the scientific documentation is limited, microbiome of healing clay is gradually gaining attention of the scientific community, as a therapeutic force playing an indispensable role in skin disease management. The present study explores the metatranscriptome profile of the Chamliyal clay, widely known for its efficacy in managing various skin problems, using Illumina NextSeq sequencing technology. The gene expression profile of the clay microbial community was analyzed through SEED subsystems of the MG-RAST server. Due to the unavailability of metatranscriptomic data on other therapeutic clays, Chamliyal's profile was compared to non-therapeutic soils, as well as healthy and diseased human skin microbiomes. The study identified Firmicutes, Proteobacteria, and Actinobacteria as the primary active microbial phyla in Chamliyal clay. These resemble those abundant in a healthy human skin microbiome. This is significant as lower levels of these phyla in the skin are linked to inflammatory skin conditions like psoriasis. Interestingly, pathogenic microbes actively metabolizing in the clay were absent. Importantly, 6% of the transcripts annotated to sulfur and iron metabolism, which are known to play a major role in skin disease management. This study provides the most comprehensive and a novel overview of the metatranscriptome of any of the healing clay available worldwide. The findings offer valuable insights into the clay microbiome's potential in managing skin disorders, inspiring future endeavors to harness these insights for medical applications.

The role of nutrition, food allergies, and gut dysbiosis in immune-mediated inflammatory skin disease: a narrative review

PURPOSE OF REVIEW

This review focuses on the emerging roles of nutrition, food allergies, and gut dysbiosis, and their influence on pediatric skin conditions such as psoriasis, hidradenitis suppurativa, and alopecia areata. As the prevalence of these conditions increases, understanding the underlying mechanisms and potential therapeutic targets is crucial for clinical practice and research.

RECENT FINDINGS

The review covers 32 recent articles that highlight the significance of the gut microbiome, nutrition, and gut dysbiosis in the pathogenesis and progression of inflammatory and immune-related pediatric skin conditions. The data suggest that food allergies and gut dysbiosis play a crucial role in disease pathogenesis.

SUMMARY

This review emphasizes the need for larger-scale studies to determine the effectiveness of dietary changes in preventing or treating inflammatory and immune-related skin conditions. Clinicians must maintain a balanced approach when implementing dietary changes in children with skin diseases like atopic dermatitis to avoid potential nutritional deficiencies and growth impairments. Further research into the complex interplay between environmental and genetic factors is warranted to develop tailored therapeutic strategies for these skin conditions in children.

Probiotics Mechanism of Action on Immune Cells and Beneficial Effects on Human Health

Immune cells and commensal microbes in the human intestine constantly communicate with and react to each other in a stable environment in order to maintain healthy immune activities. Immune system-microbiota cross-talk relies on a complex network of pathways that sustain the balance between immune tolerance and immunogenicity. Probiotic bacteria can interact and stimulate intestinal immune cells and commensal microflora to modulate specific immune functions and immune homeostasis. Growing evidence shows that probiotic bacteria present important health-promoting and immunomodulatory properties. Thus, the use of probiotics might represent a promising approach for improving immune system activities. So far, few studies have been reported on the beneficial immune modulatory effect of probiotics. However, many others, which are mainly focused on their metabolic/nutritional properties, have been published. Therefore, the mechanisms behind the interaction between host immune cells and probiotics have only been partially described. The present review aims to collect and summarize the most recent scientific results and the resulting implications of how probiotic bacteria and immune cells interact to improve immune functions. Hence, a description of the currently known immunomodulatory mechanisms of probiotic bacteria in improving the host immune system is provided.

LARP7 alleviates psoriasis symptoms in mice by regulating the SIRT1/NF-κB signaling pathway

OBJECTIVE

To unravel the role of La ribonucleoprotein 7 (LARP7), a transcriptional regulator, in the progression of psoriasis and the underlying molecular mechanisms.

METHODS

The psoriasis-like mice model was created by daily administering of imiquimod on shaved skin. The histological analysis and skin damage were evaluated in each group. The inflammation and oxidative stress response were assessed by enzyme-linked-immunosorbent serologic and immunoblot assays. The involvement of silent information regulator 1 (member of the Sirtuin family; SIRT1/nuclear factor kappa B (NF-κB) signaling pathway in LARP7-mediated psoriasis progression was also detected by immunoblot assay.

RESULTS

LARP7 relieved psoriasis symptoms in the mice model. LARP7 inhibited the expression of inflammatory cytokines as well as chemokines in psoriasis-like skin tissues. Additionally, LARP7 suppressed oxidative stress in the psoriasis-like skin tissues of mice. LARP7 inhibited the activation of the SIRT1/NF-κB signaling pathway, and therefore affected the progression of psoriasis.

CONCLUSION

LARP7 relieved psoriasis symptoms in mice by regulating the SIRT1/NF-κB signaling pathway.

Crosstalk between microbiome, regulatory T cells and HCA2 orchestrates the inflammatory response in a murine psoriasis model

The organ-specific microbiome plays a crucial role in tissue homeostasis, among other things by inducing regulatory T cells (Treg). This applies also to the skin and in this setting short chain fatty acids (SCFA) are relevant. It was demonstrated that topical application of SCFA controls the inflammatory response in the psoriasis-like imiquimod (IMQ)-induced murine skin inflammation model. Since SCFA signal via HCA2, a G-protein coupled receptor, and HCA2 expression is reduced in human lesional psoriatic skin, we studied the effect of HCA2 in this model. HCA2 knock-out (HCA2-KO) mice reacted to IMQ with stronger inflammation, presumably due to an impaired function of Treg. Surprisingly, injection of Treg from HCA2-KO mice even enhanced the IMQ reaction, suggesting that in the absence of HCA2 Treg switch from a suppressive into a proinflammatory type. HCA2-KO mice differed in the composition of the skin microbiome from wild type mice. Co-housing reversed the exaggerated response to IMQ and prevented the alteration of Treg, implying that the microbiome dictates the outcome of the inflammatory reaction. The switch of Treg into a proinflammatory type in HCA2-KO mice could be a downstream phenomenon. This opens the opportunity to reduce the inflammatory tendency in psoriasis by altering the skin microbiome.