Association between BMI and asthma in adults over 45 years of age: analysis of Global Burden of Disease 2021, China Health and Retirement Longitudinal Study, and National Health and Nutrition Examination Survey data

Background

Asthma is a major global health concern, and body mass index (BMI) is a key risk factor. This study aims to investigate the potential nonlinear relationship between BMI and asthma risk in populations over 45 years of age using large-scale, cross-national data.

Methods

This cross-sectional study utilised three databases: GBD 2021, China Health and Retirement Longitudinal Study (CHARLS; cross-sectional data from baseline survey, January 01, 2011 to December 31, 2011), and National Health and Nutrition Examination Survey (NHANES; cross-sectional data from 2011 to 2012 cycle). Participants aged ≥45 years after excluding those with missing data on BMI, asthma history, smoking history, age, sex, and BMI outside 10-80 kg/m2 were included. Asthma was defined by self-report in CHARLS and by physician diagnosis plus recent symptoms in NHANES. Smooth curve fitting was performed to visualise the BMI-asthma relationship, adjusting for multiple confounders. We applied segmented regression models to identify potential threshold effects, used likelihood ratio tests to compare linear and non-linear models, and employed bootstrap resampling for confidence intervals.

Findings

High BMI was the primary risk factor for asthma-related DALYs globally (14.93% in 2021). From CHARLS, we included 13,393 participants, comprising 6267 males (46.79%) and 7126 females (53.21%). From NHANES, we included 2925 participants, comprising 46.6% males and 53.4% females. CHARLS data revealed a U-shaped relationship between BMI and asthma risk, with critical points at 19.9 kg/m2 and 29.9 kg/m2. For BMI < 19.9 kg/m2, asthma risk increased by 28% with each unit decrease in BMI (OR = 1.28, 95% CI: 1.15-1.43). For BMI ≥ 29.9 kg/m2, asthma risk increased by 25% with each unit increase in BMI (OR = 1.25, 95% CI: 1.05-1.49). NHANES data showed a non-linear relationship with a turning point at 21.6 kg/m2. For BMI ≥ 21.6 kg/m2, asthma risk increased by 5% with each unit increase in BMI (OR = 1.05, 95% CI: 1.03-1.06).

Interpretation

This study elucidates a significant non-linear relationship between BMI and asthma risk in populations aged 45 years and older, providing insights for tailored asthma prevention strategies, although the cross-sectional design limits causal inference. Future studies should focus on collecting and stratifying longitudinal data and adjusting for asthma diagnosis timing to obtain more accurate results.

Funding

National Nature Science Foundation of China.

Evaluating the Impact of Omega-3 Fatty Acids and Genetic Susceptibility on Atopic Dermatitis in Adults

Fatty acids (FAs) involvement in atopic dermatitis (AD) prevention is inconclusive, and the modification effect by genetic risk profiles remains unknown. The aim of this study is to explore the association between circulating FAs, genetic risk factors, and AD in adults. Utilizing the UK Biobank dataset, we evaluated the impacts of FAs on the risk of elderly-onset AD and explored the combined effects of FA levels and genetic susceptibility. Plasma omega-3 levels exhibited an inverse correlation with AD risk (hazard ratio [HR]: 0.93; 95% confidence interval [CI]: 0.89-0.98), regardless of genetic predisposition. Individuals with low genetic risk and high omega-3 levels had the lowest AD risk, a 38% reduction compared to the reference category. Additionally, individuals with GA/AA on rs1692120 exhibited a significantly elevated AD risk, whereas those with more A alleles for rs174448 demonstrated a significantly diminished AD risk (both p trends <0.05). These findings suggest that increasing omega-3 intake could be a preventive strategy against AD, and tailoring prevention strategies based on genetic predispositions may enhance intervention efficacy.

Cardiac-Focused Multi-Organ Chips: Advanced Disease Modeling, Drug Testing, and Inter-Organ Communication

Heart disease remains a leading cause of mortality worldwide, posing a significant challenge to global healthcare systems. Traditional animal models and cell culture techniques are instrumental in advancing the understanding of cardiac pathophysiology. However, these methods are limited in their ability to fully replicate the heart's intricate functions. This underscores the need for a deeper investigation into the fundamental mechanisms of heart disease. Notably, cardiac pathology is often influenced by systemic factors, with conditions in other organs contributing to disease onset and progression. Cardiac-focused multi-organ chip technology has emerged to better elucidate these complex inter-organ communications and address the limitations of current in vitro models. This technology offers a novel approach by recreating the cardiac microenvironment and integrating it with other organ systems, thereby enabling more precise disease modeling and drug toxicity assessment. This review provides a comprehensive overview of the heart's structure and function, explores the advancements in cardiac organ chip development, and highlights the applications of cardiac-focused multi-organ chips in medical research. Finally, the future potential of this technology in enhancing disease modeling and therapeutic evaluation is discussed.

Rome Foundation Working Team Report on overlap in disorders of gut-brain interaction

In patients with disorders of gut-brain interaction (DGBI), overlapping non-gastrointestinal conditions such as fibromyalgia, headaches, gynaecological and urological conditions, sleep disturbances and fatigue are common, as is overlap among DGBI in different regions of the gastrointestinal tract. These overlaps strongly influence patient management and outcome. Shared pathophysiology could explain this scenario, but details are not fully understood. This overlap has been shown to be of great relevance for DGBI. In addition, symptoms considered to be caused by a DGBI could have a detectable organic cause, and in patients with a diagnosed organic gastrointestinal disease, symptoms not clearly explained by the pathology defining this organic disease are common. Thus, the aims of this Rome Foundation Working Team Report were to review the literature on overlapping conditions among patients with paediatric and adult DGBI and, based on the available epidemiological and clinical evidence, make recommendations for the current diagnostic and therapeutic approach, and for future research. Specifically, we focused on other DGBI in the same or different gastrointestinal anatomical region(s), DGBI overlap with organic bowel diseases in remission, and DGBI overlap with non-gastrointestinal, non-structural conditions.

G Protein-Coupled Receptors in Skin Aging

Skin aging is a complex biological process affected by a plethora of intrinsic and extrinsic factors that alter cutaneous functions through the modulations of signaling pathways and responses. Expressed in various cell types and skin tissue layers, G protein-coupled receptors (GPCRs) play a vital role in regulating skin aging. We have cataloged 156 GPCRs expressed in the skin and reviewed their roles in skin aging, such as pigmentation, loss of elasticity, wrinkles, rough texture, and aging-associated skin disorders. By exploring the GPCRs found in the skin, it may be possible to develop new treatment regimens for aging-associated skin conditions using GPCR ligands.

Promoting Prevention and Targeting Remission of Asthma: A EUFOREA Consensus Statement on Raising the Bar in Asthma Care

Asthma is a common, multifaceted respiratory disease with a major impact on quality of life. Despite increased insights into mechanisms underlying various asthma phenotypes and endotypes and the availability of targeted biologic treatment options, the disease remains uncontrolled in a substantial proportion of patients with risk of exacerbations, requiring systemic corticosteroids, and with progressive disease. Current international guidelines advocate for a personalized management approach to patients with uncontrolled severe asthma. The European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) asthma expert panel was convened to discuss strategies to optimize asthma care and to prevent systemic corticosteroid overuse and disease progression. In this meeting report, we summarize current concepts and recommendations and provide a rationale to implement personalized asthma management at earlier stages of the disease. The ultimate goal is to move away from the current one-size-fits-most concept, which focuses on a symptom-driven treatment strategy, and shift toward a phenotype- and endotype-targeted approach aimed at curbing the disease course by improving clinical outcomes and preserving health-related quality of life. Herein, we provide a consensus view on asthma care that advocates a holistic approach and highlight some unmet needs to be addressed in future clinical trials and population studies.

Signaling pathways in skin cancers and the protective functions of melatonin

Melatonin, a hormone primarily synthesized in the pineal gland, has an essential role in the regulation of various physiological processes, such as the sleep-wake cycle, immune function, and antioxidative responses. Emerging evidence suggests that melatonin also exerts significant protective effects against skin cancers, particularly melanoma and non-melanoma skin cancers. This review aims to provide a comprehensive overview of melatonin's multifaceted mechanisms of action in preventing and treating skin cancers, focusing on its antioxidant, photoprotective, and radioprotective properties. Melatonin's capability to modulate skin cancer's related key signaling pathways underscores its complex yet potent anticancer mechanisms. Furthermore, synergistic effects between melatonin and conventional oncology treatments, such as radiotherapy, chemotherapy, and targeted therapies, hold promise for improving treatment outcomes while mitigating adverse effects. However, while melatonin shows great potential as an adjunct in oncology treatment regimens, further research is needed to optimize its clinical applications and fully understand its safety profile and potential side effects. Overall, elucidating melatonin's role in skin cancer prevention and treatment represents a promising avenue for advancing cancer therapeutics and improving patient outcomes.

The Pigmentation of Blue Light Is Mediated by Both Melanogenesis Activation and Autophagy Inhibition through OPN3-TRPV1

Blue light, a high-energy radiation in the visible light spectrum, was recently reported to induce skin pigmentation. In this study, we investigated the involvement of TRPV1-mediated signaling along with OPN3 in blue light-induced melanogenesis as well as its signaling pathway. Operating downstream target of OPN3 in blue light-induced melanogenesis, blue light activated TRPV1 and upregulated its expression, resulting in calcium influx. Calcium ion induced the activation of calcium/calmodulin-dependent protein kinase II and MAPK. It also downregulated clusterin expression, leading to the nuclear translocation of PAX3, ultimately affecting melanin synthesis. In addition, blue light interfered with autophagy-mediated regulation of melanosomes by decreasing not only the interaction between clusterin and LC3B but the expression of activating transcription factor family. These findings demonstrate that the pigmenting effects of blue light are mediated by calcium/calmodulin-dependent protein kinase II- and MAPK-mediated signaling as well as clusterin-dependent inhibition of autophagy through OPN3-TRPV1-calcium influx, suggesting, to our knowledge, a previously unreported signaling pathway through which blue light regulates melanocyte biology. Furthermore, these results suggest that TRPV1 and clusterin could be potential therapeutic targets for blue light-induced pigmentation due to prolonged exposure to blue light.

OPN3-mediated positive regulation of angiogenesis in HUVECs through VEGFR2 interaction

Many rhodopsin-like G-protein-coupled receptors (Rh-GPCRs) are known to either promote or inhibit angiogenesis. Among these, Opsin 4 and Opsin 5 are specifically involved in vascular development within the eye. Opsin 3 (OPN3), another member of Rh-GPCRs, performs a variety of light-dependent and light-independent functions in extraocular tissue. However, its role in endothelial cells and angiogenesis remains unclear. Here, we found that OPN3 knockdown or knockout in zebrafish impairs embryonic angiogenesis and vascular development. Similarly, silencing OPN3 in human umbilical vein endothelial cells (HUVECs) inhibits cellular proliferation, migration, sprouting, and tube formation, while OPN3 overexpression promotes these cellular processes. Moreover, OPN3 regulates angiogenesis in HUVECs through the VEGFR2-AKT pathway, with OPN3 and VEGFR2 co-localizing at the plasma membrane and forming a physical complex. These findings provide new insights into the non-light-dependent functions of OPN3 in angiogenesis, expanding our understanding of its physiological roles and offering potential therapeutic strategies for angiogenesis-related diseases.

Correction: Möller et al. Melanogenesis Is Directly Affected by Metabolites of Melatonin in Human Melanoma Cells. Int. J. Mol. Sci. 2023, 24, 14947

In the original publication [...].

Characterization of Gut Microbiota in Patients with Active Spreading Vitiligo Based on Whole-Genome Shotgun Sequencing

Vitiligo is an autoimmune skin disease with a significant psychological burden and complex pathogenesis. While genetic factors contribute approximately 30% to its development, recent evidence suggests a crucial role of the gut microbiome in autoimmune diseases. This study investigated differences in gut microbiome composition and metabolic pathways between active spreading vitiligo patients and healthy controls using shotgun whole-genome sequencing in a Korean cohort. Taxonomic profiling reveals distinct characteristics in microbial community structure, with vitiligo patients showing an imbalanced proportion dominated by Actinomycetota and Bacteroidota. The vitiligo group exhibited significantly reduced abundance of specific species including Faecalibacterium prausnitzii, Faecalibacteriumduncaniae, and Meamonas funiformis, and increased Bifidobacterium bifidum compared to healthy controls. Metabolic pathway analysis identified significant enrichment in O-glycan biosynthesis pathways in vitiligo patients, while healthy controls showed enrichment in riboflavin metabolism and bacterial chemotaxis pathways. These findings provide new insights into the gut-skin axis in vitiligo pathogenesis and suggest potential therapeutic targets through microbiota modulation.

Alpha-synuclein knockout impairs melanoma development and alters DNA damage repair in the TG3 mouse model in a sex-dependent manner

Introduction

Strong evidence suggests links between Parkinson's Disease (PD) and melanoma, as studies have found that people with PD are at an increased risk of developing melanoma and those with melanoma are at increased risk of developing PD. Although these clinical associations are well-established, the cellular and molecular pathways linking these diseases are poorly understood. Recent studies have found a previously unrecognized role for the neurodegeneration-associated protein alpha-synuclein (αSyn) in melanoma; the overexpression of αSyn promotes melanoma cell proliferation and metastasis. However, to our knowledge, no studies have investigated the role of αSyn in in vivo melanoma models outside of a xenograft paradigm.

Methods

Our study created and characterized Snca knockout in the spontaneously developing melanoma TG3 mouse line, TG3+/+Snca-/-.

Results

We show that αSyn loss-of-function significantly delays melanoma onset and slows tumor growth in vivo in males. Furthermore, decreased tumor volume is correlated with a decreased DNA damage signature and increased apoptotic markers, indicating a role for αSyn in modulating the DNA damage response (DDR) pathway.

Discussion

Overall, our study may suggest that targeting αSyn and its role in modulating the DDR and melanomagenesis could serve as a promising new therapeutic target.

Compositional and Functional Profile of Gut Microbiota in a Cohort of Adult Spanish Patients with Atopic Dermatitis Using Metagenomics: A Cross-Sectional Study

Background: The role of gut dysbiosis in the pathophysiology of atopic dermatitis (AD) through immune system (IS) imbalance is a novel line of investigation currently under discussion. This study aimed to characterize compare the composition and functional profile of the gut microbiota (GM) between adults with AD and healthy individuals. Methods: Observational cross-sectional study, where fecal samples from 70 adults (38 patients and 32 controls) were analyzed using metagenomics and bioinformatics. Results: Differences between the GM of patients with AD and healthy individuals were demonstrated. Reduced microbial diversity was found in subjects with AD. Bacterial species with lower abundance primarily belonged to the families Ruminococcaceae, Akkermansiaceae, and Methanobacteriaceae. Several microbial metabolic pathways were found to be decreased in patients with AD, including amino acid biosynthesis, vitamin biosynthesis, fatty acids and lipids biosynthesis, and energy metabolism. Conclusion: Adults with AD exhibited a distinct GM compared to healthy individuals. Changes were demonstrated both compositionally and functionally. Further investigation is mandatory to elucidate the potential link and causal relationship between gut dysbiosis and AD, which may be crucial for a deeper understanding of the disease's pathophysiology and the development of novel therapeutic approaches.

Implication of Immunobiological Function of Melanocytes in Dermatology

Melanocytes are essential for regulating pigmentation and providing photoprotection in human skin. Originating from neural crest cells, these cells migrate to the basal layer of the epidermis and hair follicles during embryogenesis. Melanosomes, the specialized, membrane-bound organelles are essential for melanin synthesis. Beyond their role in pigmentation, melanocytes exhibit complex immune functions, expressing a variety of immune-related markers and receptors, such as pattern recognition receptors (PRRs), major histocompatibility complex class II (MHC-II) molecules, CD40, intercellular adhesion molecule 1 (ICAM-1), and programmed death-ligand 1 (PD-L1). These receptors allow melanocytes to detect environmental signals and engage in the innate immune response. Furthermore, melanocytes release various immunomodulatory substances, including proinflammatory cytokines, chemokines, and damage-associated molecular patterns (DAMPs), contributing to immune regulation. The immune functions of melanocytes are significantly influenced by external factors such as ultraviolet radiation (UVR), the microbiome, and oxidative stress. In different skin diseases, these immune functions may vary. For example, vitiligo, a common hypopigmentary disorder, is primarily driven by an autoimmune response targeting melanocytes, giving rise to depigmentation and the appearance of white patches. In contrast, melanoma, a form of skin cancer that arises from melanocytes, is closely linked to UV exposure. This review highlights the diverse immunobiological functions of melanocytes and their implications in dermatology.

Eosinophil-airway epithelial cell crosstalk reveals the eosinophil-mediated DUOX1 upregulation in a murine allergic inflammation setting

Blood and airway eosinophilia represent markers for the endotype-driven treatment of allergic asthma. Little is known on mechanisms that link eosinophils and airway epithelial cells before and after these cells are infiltrated by eosinophils during allergic response. Given that innate immune mechanisms, mainly mediated by epithelial-derived cytokines (interleukin [IL]-33, IL-25, TSLP [thymic stromal lymphopoietin]), induce eosinophil-maturing/attractive substances, we thought to evaluate the crosstalk between eosinophils and airway epithelial cells in the context of IL-33-mediated allergic inflammation. DUOX1 was previously described in clinically relevant aspects of allergic inflammation in a HDM -induced allergic asthma mice model, and in patients with chronic sinusitis or allergic asthma. Thus, we evaluated the involvement of HDM and eosinophils in the regulation of DUOX1 in airway epithelial cells. To recapitulate the lung environment present at the allergen challenge time in acute asthma, we set up an in vitro model based on murine bone marrow-derived eosinophils differentiated with IL-5 and then activated with IL-33 (EOs33) and TC1 or C57 airway epithelial cells. We found that treatment of epithelial cells with HDM induced an eosinophil-attractive environment and increased DUOX1 expression. Importantly, we found that the coculture of airway epithelial cells with EOs33 or with conditioned medium from EOs33 enhanced the expression of DUOX1, which was further increased by combined stimulation (HDM plus EOs33). Our results suggest that lung recruited eosinophils once activated by IL-33 could be involved in a crosstalk loop with airway epithelial cells by DUOX1-mediated IL-33 secretion.

Exploring Causal Relationships Between Gut Microbiota, Inflammatory Cytokines, and Inflammatory Dermatoses: A Mendelian Randomization Study

Background

Some studies have established a link between gut microbiota, inflammatory proteins, and inflammatory dermatoses. However, the mediating role of inflammatory proteins in the gut-skin axis remains unclear.

Methods

Data on inflammatory proteins and gut microbiota were drawn from the GWAS catalog and MiBioGen consortium, with inflammatory skin disease data provided by the FinnGen consortium. Using genome-wide association studies (GWAS), we performed linkage disequilibrium score regression (LDSC) to assess genetic correlations and conducted a two-step Mendelian Randomization (MR) analysis to investigate circulating inflammatory proteins as potential mediators between gut microbiota and inflammatory dermatoses.

Results

MR analysis identified 38 gut microbiota and 23 inflammatory proteins associated with inflammatory skin diseases. After false discovery rate (FDR) correction, four gut microbiota taxa-Eubacterium fissicatena, Bacteroidaceae, Allisonella, and Bacteroides, remained statistically significant (OR = 1.32, 95% CI: 1.16-1.50, adjusted P = 0.007; OR = 2.25, 95% CI: 1.48-3.42, adjusted P = 0.026; OR = 1.42, 95% CI: 1.18-1.70, adjusted P = 0.014; OR = 2.25, 95% CI: 1.48-3.42, adjusted P = 0.013), with only IL-18R1 significantly associated with eczema (OR = 1.05, 95% CI: 1.03-1.08, adjusted P = 0.017). Further mediation analysis showed that IL-15RA mediated 11% of the pathway between Veillonellaceae and eczema, while FGF19 mediated 6% of the pathway between genus LachnospiraceaeUCG001 and psoriatic arthritis.

Conclusion

These findings provide potential targets for therapeutic interventions in inflammatory skin diseases.

Investigating the link between toll-like receptor 9 gene variants and vitiligo susceptibility - A cross-sectional comparative study

Background The Toll-like receptor (TLR) family, which recognises diverse molecular patterns on immune cells, has been implicated in several autoimmune diseases, including vitiligo. Objectives This study will investigate the potential association between the TLR9 gene polymorphism rs187084 and clinical features in Egyptian vitiligo patients, employing the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for TLR9 genotyping. Methods Genomic DNA was extracted from the peripheral blood of 30 vitiligo patients and 20 healthy controls using a DNA isolation kit. TLR9 rs187084 gene polymorphisms were assessed using PCR-RFLP techniques. Genotype distributions and allele frequencies were compared between vitiligo patients and controls. Additionally, the associations between TLR9 single nucleotide polymorphism (SNP) genotypes and clinical features including demographic characteristics, family history, disease onset, activity, duration, and hair involvement in vitiligo patients were statistically analysed. Results The CC genotype of rs187084, which is considered protective, was found to be more prevalent in the control group compared to the vitiligo group. However, no significant associations were identified between TLR9 SNP genotypes and demographic or clinical parameters, including family history, disease onset, activity, duration, and hair involvement (leukotrichia) in vitiligo patients. Limitation The limitations of this study include a small sample size and the methodological constraints of PCR-RFLP, necessitating further research to confirm our findings and elucidate underlying mechanisms. Conclusions The significant difference in the distribution of the TLR9 rs187084 polymorphism between vitiligo patients and controls highlights the potential role of innate immunity in the susceptibility to vitiligo. Despite the absence of significant associations with clinical parameters in this study, these findings underscore the importance of genetic factors in the pathogenesis of vitiligo.

Ganoderic Acid Ameliorates Ulcerative Colitis by Improving Intestinal Barrier Function via Gut Microbiota Modulation

Ulcerative colitis (UC) is a chronic and recurrent gastrointestinal disease that affects millions of humans worldwide and imposes a huge social and economic burden. It is necessary to find safe and efficient drugs for preventing and treating UC. The aim of this study was to determine whether ganoderic acid (GA), the main bioactive components of Ganoderma lucidum, has preventive and therapeutic effect on UC in a dextran sulfate sodium (DSS)-induced UC mouse model. Our experimental results showed that GA significantly ameliorated the body weight loss and disease activity index (DAI) of UC mice. GA significantly restored 11% of the colon length and 69% of the spleen index compared to UC mice. GA significantly decreased the intestinal inflammatory response and improved the barrier function of the intestine by upregulating the tight junction proteins Zonula occludens-1 (ZO-1), occludin and claudin-1. A co-housing experiment showed that gut microbiota accounted for the therapeutic activity of GA on UC, which was confirmed by fecal microbiota transplantation from GA-treated mice to the UC mice. Furthermore, 16S rDNA high-throughput sequencing of fecal bacteria showed that GA significantly enriched the abundance of Lactobacillus, Oscillospira, Odoribacter and Ruminococcus, which were positively correlated with colon length. Furthermore, this study found the functional metabolites, including Indole-3-acetaldehyde (IAAld), Glutamine (Gln) and Glutathione (GSH), reduced barrier damage in the Caco-2 cell model. In conclusion, this study suggests that GA could ameliorate UC by improving intestinal barrier function via modulating gut microbiota and associated metabolites.

Aspergillus in Children and Young People with Cystic Fibrosis: A Narrative Review

Cystic fibrosis is a severe, inherited, life-limiting disorder, and over half of those living with CF are children. Persistent airway infection and inflammation, resulting in progressive lung function decline, is the hallmark of this disorder. Aspergillus colonization and infection is a well-known complication in people with CF and can evolve in a range of Aspergillus disease phenotypes, including Aspergillus bronchitis, fungal sensitization, and allergic bronchopulmonary aspergillosis (ABPA). Management strategies for children with CF are primarily aimed at preventing lung damage and lung function decline caused by bacterial infections. The role of Aspergillus infections is less understood, especially during childhood, and therefore evidence-based diagnostic and treatment guidelines are lacking. This narrative review summarizes our current understanding of the impact of Aspergillus on the airways of children and young people with CF.

Identification and Experimental Validation of Biomarkers Related to MiR-125a-5p in Chronic Obstructive Pulmonary Disease

Purpose

The miR-125a-5p has been reported influence the development of lung cancer, however, the link between it and chronic obstructive pulmonary disease (COPD) is still not well understood. Hence, this study was designed to investigate the molecular pathway by which miR-125a-5p related biomarkers were involved in COPD.

Patients and Methods

The differentially expressed genes (DEGs) and module genes related to COPD in GSE100153 were screened out by differential analysis and weighted gene co-expression network analysis, respectively. Then, the target genes of miR-125a-5p obtained from miRWalk database were intersected with DEGs and module genes, followed by identification of biomarkers through SVM-RFE algorithms. Moreover, the gene set enrichment analysis, immune infiltration analysis, construction of regulatory network, single-cell analysis and Mendelian randomization (MR) analysis were performed. At last, the expression levels of the biomarkers were further validated in GSE100153 and GSE146560 as well as in qRT-PCR.

Results

A total of 10 genes were acquired by intersecting the 126 DEGs, the 3989 module genes, and 2329 target genes, of which PITHD1, CNTNAP2 and GUCD1 were identified as biomarkers. Enrichment analysis showed their roles in various cellular functions. In addition, significant associations were identified between 9 distinct cells and biomarkers. Subsequently, 5 TFs and 63 therapeutic agents were predicted as biomarkers. Moreover, GUCD1 and PITHD1 were significantly different between case and control in T cells and Alveolar cells. In COPD, GUCD1 and PITHD1 were significantly down-regulated in GSE100153 and GSE146560 datasets and confirmed by qRT-PCR.

Conclusion

In our study, PITHD1, CNTNAP2, and GUCD1 were recognized as biomarkers related to miR-125a-5p-related genes in COPD, providing new references for treatment of COPD.

Gut microbiome in dermatology - A narrative review

The gut microbiome and human body have co-evolved in a synergistic host-microbial relationship. The ideal composition of human gut microbiota is an elusive concept, but every individual has a unique gut microbiota profile with regional differences. Newer diagnostic techniques have helped identify different bacteria and their roles in health and disease. The gut microbiome composition is affected by various factors like age, diet, immune system, environmental factors, exercise, and drugs. The microbiome has varied roles in metabolism, immune response, immune tolerance and antimicrobial protection. Diet plays an important role in maintaining the gut microbial diversity. Loss of homoeostasis in the microbiome results in dysbiosis. Dysbiosis plays a role in many dermatological diseases like atopic dermatitis, psoriasis, acne, rosacea, hidradenitis suppurativa, connective tissue disorders and many other systemic conditions like obesity, diabetes, neurological disease and malignancy. Reconstitution of the gut microbiome ecology in the form of bacteriotherapy with the reintegration of certain strains of microbiota has a beneficial role in many of these disorders.

Why Symptoms Linger in Quiescent Crohn's Disease: Investigating the Impact of Sulfidogenic Microbes and Sulfur Metabolic Pathways

INTRODUCTION

Even in the absence of inflammation, persistent symptoms in patients with Crohn's disease (CD) are prevalent and worsen quality of life. We previously demonstrated enrichment in sulfidogenic microbes in quiescent Crohn's disease patients with (qCD + S) vs without persistent GI symptoms (qCD-S). Thus, we hypothesized that sulfur metabolic pathways would be enriched in stool while differentially abundant microbes would be associated with important sulfur metabolic pathways in qCD + S.

METHODS

We performed a multicenter observational study nested within SPARC IBD. Quiescent inflammation was defined by fecal calprotectin level < 150 mcg/g. Persistent symptoms were defined by CD-PRO2. Active CD (aCD) and non-IBD diarrhea-predominant irritable bowel syndrome (IBS-D) were included as controls.

RESULTS

Thirty-nine patients with qCD + S, 274 qCD-S, 21 aCD, and 40 IBS-D underwent paired shotgun metagenomic sequencing and untargeted metabolomic profiling. The fecal metabolome in qCD + S was significantly different relative to qCD-S and IBS-D but not aCD. Patients with qCD + S were enriched in sulfur-containing amino acid pathways, including cysteine and methionine, as well as serine, glycine, and threonine. Glutathione and nicotinate/nicotinamide pathways were also enriched in qCD + S relative to qCD-S, suggestive of mitochondrial dysfunction, a downstream target of H2S signaling. Multi-omic integration demonstrated that enriched microbes in qCD + S were associated with important sulfur metabolic pathways. Bacterial sulfur metabolic genes, including CTH, isfD, sarD, and asrC, were dysregulated in qCD + S. Finally, sulfur metabolites with and without sulfidogenic microbes showed good accuracy in predicting the presence of qCD + S.

DISCUSSION

Microbial-derived sulfur pathways and downstream mitochondrial function are perturbed in qCD + S, which implicate H2S signaling in the pathogenesis of this condition. Future studies will determine whether targeting H2S pathways results in improved quality of life in qCD + S.

Emerging Concepts in Cytokine Regulation of Airway Remodeling in Asthma

Asthma, a chronic respiratory condition that has seen a dramatic rise in prevalence over the past few decades, now affects more than 300 million people globally and imposes a significant burden on healthcare systems. The key pathological features of asthma include inflammation, airway hyperresponsiveness, mucus cell metaplasia, smooth muscle hypertrophy, and subepithelial fibrosis. Cytokines released by lung epithelial cells, stromal cells, and immune cells during asthma are critical to pathological tissue remodeling in asthma. Over the past few decades, researchers have made great strides in understanding key cells involved in asthma and the cytokines that they produce. Epithelial cells as well as many adaptive and innate immune cells are activated by environmental signals to produce cytokines, namely, type 2 cytokines (IL-4, IL-5, IL-13), IFN-γ, IL-17, TGF-β, and multiple IL-6 family members. However, the precise mechanisms through which these cytokines contribute to airway remodeling remain elusive. Additionally, multiple cell types can produce the same cytokines, making it challenging to decipher how specific cell types and cytokines uniquely contribute to asthma pathogenesis. This review highlights recent advances and provides a comprehensive overview of the key cells involved in the production of cytokines and how these cytokines modulate airway remodeling in asthma.

Daily egg intake may reduce sensitisation to common allergenic foods among six- to nine-month-old south African infants: A randomized controlled trial

BACKGROUND

This study aimed to investigate sensitization to eggs and other common allergenic foods, allergic symptoms, and fatty acid status among infants after introducing daily eggs as a complementary food for 6 months.

METHODS

This secondary analysis used data from a randomized controlled trial of 500 infants aged 6-9 months in Jouberton, South Africa, who were randomly assigned to receive one egg daily, n = 250 (treatment) or no egg, n = 250 (control) for 6 months. Clinical allergy symptoms were assessed with the Childhood Allergy and Immunology Research questionnaire. Infants were tested with a skin prick test for egg sensitization at baseline and at the end of the study for additional food allergens. The fatty acid composition was analyzed in whole blood at the endpoint.

RESULTS

At the endpoint, egg sensitization was 1.9% in the egg intervention group and 2.0% in the control group (aOR 0.936 [95% CI 0.229, 3.822]; p = .926) and all foods sensitization was 7.5% in the egg intervention group and 12.9% in the control group (aOR 0.515 [0.264, 1.005]; p = .052). There were no reported acute egg-related allergy symptoms at baseline and midpoint in the two groups. The incidence of allergic disease during the study was 7.5% in the egg intervention group and 13.4% in the control group (aOR = 0.545 [95% CI: 0.283, 1.048]; p = .069). The total and long-chain polyunsaturated fatty acid omega-6/omega-3 ratios were higher in the intervention group (β = .173 [0.291, 2.898], p = .021 and β = .198 [0.149, 0.902], p = .007) with no effect on omega-3 fatty acid composition.

CONCLUSION

Complementary feeding with daily eggs may reduce overall allergic sensitization to common allergenic foods.

Targeting MELK in tumor cells and tumor microenvironment: from function and mechanism to therapeutic application

Maternal embryonic leucine zipper kinase (MELK), a member of the adenosine monophosphate-activated protein kinase (AMPK) protein family, has been reported to be involved in the regulation of many cellular events. The aberrant expression of MELK is associated with tumorigenesis and malignant progression of various tumors. Moreover, MELK plays an essential role in the regulation of tumor microenvironment (TME), which affects the function of immune cells and the responsiveness to immunotherapy. Currently, small molecule inhibitors targeting MELK have been developed and evaluated in clinical trials. A comprehensive understanding of MELK may provide clues and confidence for subsequent basic research and scientific transformation. In this review, we provide a comprehensive overview of the structural features, molecular biological functions, and critical roles of MELK in tumors and TME, as well as the targeted agents under development for the treatment of tumors and discuss the perspective for MELK-targeted therapies for tumors.

Allergen-Specific Immunotherapy and Trained Immunity

The high prevalence of allergic diseases reached over the last years is attributed to the complex interplay of genetic factors, lifestyle changes, and environmental exposome. Allergen-specific immunotherapy (AIT) is the single therapeutic strategy for allergic diseases with the potential capacity to modify the course of the disease. Our knowledge of the mechanisms involved in allergy and successful AIT has significantly improved. Recent findings indicate that long-term allergen tolerance upon AIT discontinuation not only relies on the generation of proper adaptive immune responses by the generation of allergen-specific regulatory T and B cells enabling the induction of different isotypes of blocking antibodies but also relies on the restoration of proper innate immune responses. Trained immunity (TRIM) is the process by which innate immune cells acquire memory by mechanisms depending on metabolic and epigenetic reprogramming, thus conferring the host with increased broad protection against infection. This concept was initially explored for infectious diseases, as well as for vaccination against infections, but compelling experimental evidence suggests that TRIM might also play a role in allergy and AIT. Hyperinflammatory innate immune responses in early life, likely due to TRIM maladaptations, lead to aberrant type 2 inflammation-enhancing allergy. However, exposure to farming environments and specific microbes prevents recurrent infections and allergy development, likely due to mechanisms partially depending on TRIM. TRIM-based vaccines and next-generation AIT vaccines inducing metabolic and epigenetic reprogramming in innate immune cells and their precursors have shown protective antiallergic effects. A better understanding of the factors involved in early-life TRIM mechanisms in the context of allergy and the identification and characterization of novel tolerance inducers might well enable the design of alternative TRIM-based allergen vaccines for allergic diseases.

[Vitiligo-update on pathogenesis, diagnostics and therapy]

Vitiligo is a common skin disease leading to depigmentation that is associated with progressive destruction of melanocytes. The main subtype, nonsegmental vitiligo (NSV), is considered a chronic autoimmune disease leading to activation of melanocyte-specific CD8+ lymphocytes and development of a cutaneous immune memory. Vitiligo can result in significant impairment of quality of life and is associated with a number of comorbidities. Despite the existence of national guidelines and international treatment recommendations, there is a strong need for improved health care for patients with vitiligo. The options in the treatment algorithm for vitiligo are similar and consisted until recently of only topical and systemic corticosteroids, topical calcineurin inhibitors, phototherapy, and surgical interventions. New insights into the pathobiological role of the interferon signature in vitiligo have most recently contributed to the approval of the first vitiligo-specific therapy with the topical Janus kinase 1/2 inhibitor ruxolitinib for patients with NSV.

Single-cell RNA sequencing of chronic idiopathic erythroderma defines disease-specific markers

BACKGROUND

Chronic erythroderma is a potentially life-threatening condition that can be caused by various diseases, but approximately 30% of cases remain idiopathic, often with insufficient treatment options.

OBJECTIVE

We sought to establish a molecular disease map of chronic idiopathic erythroderma (CIE).

METHODS

We performed single-cell RNA sequencing combined with T-cell receptor sequencing of blood and skin from 5 patients with CIE and compared results with 8 cases of erythrodermic cutaneous T-cell lymphoma (eCTCL), 15 cases of moderate to severe atopic dermatitis, 10 cases of psoriasis, and 20 healthy control individuals.

RESULTS

In eCTCL, we found strong expansion of CD4+ malignant clones with a CCR7+SELL+ central memory phenotype. In contrast, CIE exhibited a pattern of low-level, but consistent, expansion of CD8A+KLRK1+ T-cell clones, both in blood and in skin. KLRK1 was also expressed by CCR10+FUT7+ skin-homing CIE blood T cells that had increased proliferation rates and were absent in all other conditions. While patients with CIE and eCTCL lacked the strong type 2 or type 17 immune skewing typically found in atopic dermatitis or psoriasis, respectively, they were characterized by upregulation of MHC II genes (HLA-DRB1, HLA-DRA, and CD74) in keratinocytes and fibroblasts, most likely in an IFN-γ-dependent fashion. Overall, we found the strongest upregulation of type 1 immune mediators in CIE samples, both in the expanded CD8A+ clones and in the tissue microenvironment.

CONCLUSIONS

Despite the notion that CIE might be a mere bundle of various yet uncharacterized disease processes, we found specific pathogenic signatures in these patients, which were different from other forms of erythroderma. These data might help to improve our pathogenic understanding of the blood and skin compartments of CIE, aiding in discovery of future treatment targets.

Cytosolic mtDNA-cGAS-STING axis mediates melanocytes pyroptosis to promote CD8+ T-cell activation in vitiligo

BACKGROUND

The cGAS-STING axis, a DNA sensor pathway, has recently emerged as a key hub in sensing stress signals and initiating the immune cascade in several diseases. However, its role in the pathogenesis of vitiligo remains unclear.

OBJECTIVE

To explore the pathogenic role of the cGAS-STING axis in linking oxidative stress and CD8+ T-cell-mediated anti-melanocytic immunity in vitiligo.

METHODS

The expression status of the cGAS-STING axis and cytosolic mtDNA were evaluated in the oxidatively stressed epidermal cells and vitiligo perilesional skin, respectively. Then, we investigated the activation of cGAS-STING axis in mtDNA-treated melanocytes, and the influence of cGAS or STING silencing on mtDNA-induced melanocytes pyroptosis. Finally, the paracrine effects of melanocytes pyroptosis on CD8+ T cell activation were explored.

RESULTS

We initially demonstrated that the cGAS-STING axis in melanocytes was highly susceptible to oxidative stress and activated in the vitiliginous melanocytes of perilesional skin, accompanied by enhanced cytosolic mtDNA accumulation. Our mechanistic in vitro experiments confirmed that oxidative stress-induced mitochondrial damage in epidermal cells led to cytosolic mtDNA accumulation, which served as a trigger in activating the cGAS-STING axis in melanocytes. Furthermore, the cytosolic mtDNA-cGAS-STING axis was verified to mediate melanocytes pyroptosis. More importantly, we found that IL-1β and IL-18 produced by pyroptotic melanocytes promoted the activation of CD8+ T cells from patients with vitiligo.

CONCLUSION

The present study confirmed that the cytosolic mtDNA-cGAS-STING axis of melanocytes played an important role in oxidative stress-triggered CD8+ T-cell response, providing novel insights into mechanisms underlying vitiligo onset.

The glycoprotein GPNMB protects against oxidative stress through enhanced PI3K/AKT signaling in epidermal keratinocytes

Vitiligo, an autoimmune disease caused by environmental and genetic factors, is characterized by the specific loss of epidermal melanocytes (MCs). IFN-γ, predominantly derived from MC-targeting CD8+ T cells, plays a key role in vitiligo pathogenesis. Previously, we found that glycoprotein nonmetastatic melanoma protein B (GPNMB) is specifically lost in the basal epidermal layer of vitiligo lesions and downregulated by IFN-γ in normal human epidermal keratinocytes (KCs) (NHEKs). This study aimed to determine the role of KC GPNMB in normal and vitiligo epidermis and demonstrated that GPNMB plays a protective role against H2O2-induced oxidative stress due to its extracellular domain. In contrast, the NRF2/KEEP1 system was not involved in the anti-oxidative response in NHEKs but was active in MCs. GPNMB knockdown reduced the phosphorylation levels of AKTT308 and AKTS473 after H2O2 treatment, accompanied by reduced Dickkopf-1 (DKK1) mRNA and protein production and decreased FOXM1 mRNA expression. These results suggested that GPNMB protects KCs from H2O2-induced cell death through enhanced PI3K/AKT signaling, and WNT/β-catenin/FOXM1 and DKK1/CKAP4/AKT pathways. Furthermore, a significant increase in thioredoxin-interacting protein (TXNIP) following GPNMB knockdown was observed, indicating the enhanced phosphorylation of JNK and p38 and suppression of WNT/β-catenin signaling. These results suggest that the decreased expression of epidermal GPNMB in vitiligo lesions triggers increased sensitivity to H2O2-induced oxidative stress and decreased WNT/β-catenin signaling, consistent with the pathological features of the vitiligo epidermis. These findings may enhance our understanding of vitiligo pathogenesis, provide insights into the reduced risk of epidermal cancers, and highlight novel targets for treatment.

Copper homeostasis and pregnancy complications: a comprehensive review

Pregnancy complications pose challenges for both pregnant women and obstetricians globally, with the pathogenesis of many remaining poorly understood. Recently coined as a mode of cell death, cuproptosis has been proposed but remains largely unexplored. This process involves copper overload, resulting in the accumulation of fatty acylated proteins and subsequent loss of iron-sulfur cluster proteins. This cascade induces proteotoxic stress, leading to cell death. In recent years, studies have indicated a connection between abnormal copper metabolism and several pregnancy-related diseases, including maternal placental dysplasia, gestational diabetes mellitus (GDM), gestational hypertension (PIH), preterm birth or abortion, as well as conditions in offspring such as intrauterine growth restriction (IUGR), allergic disease, Menkes disease, and Wilson's disease. Investigating the mechanism of cuproptosis and abnormal copper metabolism in these pregnancy-related diseases emerges as a critical research area. This article provides a concise review of cuproptosis mechanisms and emphasizes the association between abnormal copper metabolism and pregnancy-related diseases. Nevertheless, the doubtful viewpoints were also discussed.

Vitamin D and its analogs in immune system regulation

Vitamin D was discovered as the cure for nutritional rickets, a disease of bone growth arising from inadequate intestinal calcium absorption, and for much of the 20th century, it was studied for its critical role in calcium homeostasis. However, we now recognize that the vitamin D receptor and vitamin D metabolic enzymes are expressed in numerous tissues unrelated to calcium homeostasis. Notably, vitamin D signaling can induce cellular differentiation and cell cycle arrest. Moreover, the vitamin D receptor and the enzyme CYP27B1, which produces the hormonal form of vitamin D, 1,25-dihydroxyvitamin D (1,25D), are expressed throughout the immune system. In addition, CYP27B1 expression in immune cells is regulated by physiological inputs independent of those controlling its expression in calcium homeostatic tissues. These observations have driven the development of 1,25D-like secosteroidal analogs and nonsecosteroidal analogs to separate the effects of vitamin D on cell differentiation and function from its calcemic activities. Notably, some of these analogs have had considerable success in the clinic in the treatment of inflammatory and immune-related disorders. In this review, we described in detail the mechanisms of vitamin D signaling and the physiological signals controlling 1,25D synthesis and catabolism, with a focus on the immune system. We also surveyed the effects of 1,25D and its analogs on the regulation of immune system function and their implications for human immune-related disorders. Finally, we described the potential of vitamin D analogs as anticancer therapeutics, in particular, their use as adjuncts to cancer immunotherapy. SIGNIFICANCE STATEMENT: Vitamin D signaling is active in both the innate and adaptive arms of the immune system. Numerous vitamin D analogs, developed primarily to minimize the dose-limiting hypercalcemia of the active form of vitamin D, have been used widely in preclinical and clinical studies of immune system regulation. This review presents a description of the mechanisms of action of vitamin D signaling, an overview of analog development, and an in-depth discussion of the immunoregulatory roles of vitamin D analogs.

Segmental vitiligo: autoimmune pathogenesis, neuronal mechanisms, and somatic mosaicism

Vitiligo is a common depigmentation disorder classified into nonsegmental vitiligo (NSV) and segmental vitiligo (SV). SV accounts for 5-27.9% of patients with vitiligo. The primary pathogenesis of NSV involves the autoimmune-mediated destruction of melanocytes. Recently, an autoimmune pathogenesis of SV was identified. High levels of melanocyte antigen-specific CD8+ T cells are found in early SV lesional skin infiltrating around melanocytes along the basal layer. Mixed vitiligo suggests an overlap in pathogenesis between SV and NSV. In active SV, serum innate immune cytokines, and CD8+ T cell cytokines are increased. Oxidative stress in SV may activate autoimmune responses. SV pathogenesis is associated with a local cytotoxic response targeting epidermal melanocytes. Theories have been put forward to explain the segmental pattern in SV. The previous basis of the neurogenic theory that SV results from dermatomes is no longer accepted. However, there are still research reports supporting this theory. Evaluating the distribution pattern of SV lesions has provided clues to the mosaicism detection of suspected melanocytic defects at the site of SV lesions, supporting this theory. Evidence points to a cytotoxic response targeting mosaic melanocytes. Understanding SV's autoimmune pathogenesis prompts a reevaluation of immunosuppressive medical treatments for SV. The excellent results of autologous melanocyte transplantation in SV lesions compared with the moderate to limited results in patients with NSV support the mosaicism theory.

Escherichia Abundance and Metabolism Align with Vitiligo Disease Activity

Vitiligo is a cutaneous autoimmune disorder characterized by progressive depigmentation due to melanocyte destruction by cytotoxic T cells. Genetic factors predispose patients to the disease and are supported by environmental factors that often initiate new disease episodes. We investigated whether disease outcomes were partially defined by pathogenic microbes that drive nutrient deficiency and inflammation. Our study presents the results of research on the diet and gut microbiome composition of patients with vitiligo and healthy controls from Kazakhstan and the United States. Dietary nutrient intake was assessed using the National Institutes of Health-generated Diet History Questionnaire. Patients with active vitiligo exhibit a limited intake of specific fatty acids, amino acids, fiber, and zinc. Disease activity was further characterized by the abundance of Odoribacter and Escherichia in the gut. Metabolic pathway analysis supported the role of the Escherichia genus in disease activity by limiting energy metabolism and amino acid biosynthetic pathways. Disease activity also aligned with elevated circulating pro-inflammatory cytokines. These findings suggest that nutritional limitations are not compensated by metabolites from the gut microbiome in active disease, potentially leaving room for inflammation and exacerbating vitiligo. The intricate relationship among diet, gut microbiome composition, and disease progression in vitiligo highlights potential avenues for targeted interventions to reduce autoimmune activity and improve patient outcomes.

Toll-like receptors in atopic dermatitis: pathogenesis and therapeutic implications

Toll-like receptors (TLR), the key players of the innate immune system, contribute to the pathogenesis of atopic dermatitis (AD) through multiple pathways. TLRs play a crucial role in delaying barrier repair, promoting Th2-mediated dermatitis, shifting the response toward Th1 in the chronic phase, and contributing to the establishment of the itch-scratch cycle, as well as mediating the effects of UV radiation. The dysregulation of proinflammatory and immunomodulatory effects of TLRs can be attributed to their ligand structures, receptor heterodimerization, the relative frequency of each TLR, interactions with other receptors/signalling pathways, cytokine milieu, and genetic polymorphisms. Current AD treatments like vitamin-D analogs, tacrolimus, and cyclosporine partially work through TLR modulation. Direct TLR stimulation using different compounds has shown therapeutic benefits in preclinical studies. However, significant challenges exist, including off-target effects due to ubiquitous TLR expression and complex roles in immune responses. Future directions include CRISPR-based gene editing to understand TLR functions, development of specific TLR modulators for targeted therapy, and machine learning applications to predict drug responses and identify novel ligands. Patient heterogeneity, including the presence or absence of polymorphisms, variations in TLR expression levels, and differences in immune responses, underscores the need for personalized therapeutic approaches.

An Updated Review on the Use of Noninvasive Respiratory Supports in the Management of Severe Asthma Exacerbations

Asthma is a reversible clinical condition characterized by airway obstruction due to bronchial smooth muscle contraction, inflammation and a hypersecretive state. Severe asthma exacerbations (SAE) may be a part of the natural history of this condition. Patients presenting with SAE are at higher risk of recurrent attacks, often nonresponsive to medical therapy and eventually requiring invasive mechanical ventilation (MV). The use of noninvasive respiratory supports (NRSs) may be beneficial in patients with SAE who are at risk of developing acute respiratory failure (ARF). However, their application is insufficiently supported by the evidence, as reports on their application in asthmatic patients are scarce and only a few retrospective studies with a limited number of participants have been published to date. This review discusses the potentialities of NRS in the treatment of SAE, with reference to the pathophysiological background and future perspectives on their use in asthma management.

C24 Ceramide Lipid Nanoparticles for Skin Wound Healing

Background/Objectives: C24 ceramide plays a crucial role in skin regeneration and wound healing; however, its hydrophobic nature limits its application in therapeutic formulations. This study aims to enhance the bioavailability and efficacy of C24 ceramide by developing ceramide-based lipid nanoparticles (C24-LNP) and evaluate their impact on skin regeneration and wound healing. Methods: C24-LNP was synthesized and characterized for aqueous stability and bioavailability. In vitro experiments were conducted to assess its effects on keratinocyte proliferation and migration. Molecular biological analysis examined key signaling pathways, including AKT and ERK1/2 phosphorylation. Additionally, an in vivo mouse wound model was utilized to evaluate wound healing efficacy, with histological analysis performed to assess epidermal and dermal regeneration. Results: C24-LNP exhibited improved aqueous stability and bioavailability compared to free C24 ceramide. In vitro studies demonstrated that C24-LNP significantly promoted keratinocyte proliferation and migration. Molecular analysis revealed activation of the AKT and ERK1/2 signaling pathways, which are critical for cell growth and skin regeneration. In vivo wound healing experiments showed that C24-LNP accelerated wound closure compared to the control group. Histological analysis confirmed enhanced epidermal and dermal regeneration, leading to improved structural and functional skin repair. Conclusion: The lipid nanoparticle formulation of C24 ceramide effectively increases its bioavailability and enhances its therapeutic efficacy in skin regeneration and wound healing. C24-LNP presents a scalable and cost-effective alternative to traditional growth factor-based therapies, offering significant potential for clinical applications in wound care and dermatological treatments.

Allergens in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex relationship to allergens. While AD itself is not an allergic reaction and does not necessarily involve allergen sensitization, AD patients show higher rates of sensitization to food and inhalant allergens compared to the general population. Recent evidence refining the "dual allergen exposure hypothesis" demonstrates that early oral exposure to allergens through an intact gastrointestinal barrier typically promotes tolerance, while exposure through compromised skin or respiratory barriers often leads to sensitization. Therefore, the impaired skin barrier function in AD patients increases the risk of transcutaneous sensitization and may interfere with oral tolerance development. Interestingly, AD patients' sensitivity to contact allergens (such as metals and fragrances) is not necessarily higher than that of the general population, which may be related to the inherent properties of these allergens. Personalized allergen testing can help guide appropriate allergen avoidance and reintroduction strategies in AD management. The insights into optimal allergen exposure conditions have also expanded the potential applications of allergen-specific immunotherapy in preventing AD onset in high-risk populations and halting the atopic march.

Radiotherapy plus a self-gelation powder encapsulating tRF5-GlyGCC inhibitor potentiates natural kill cell immunity to prevent hepatocellular carcinoma recurrence

Hepatocellular carcinoma (HCC) recurrence postresection represents a thorny problem in clinical practice, of which impaired natural killer (NK) cell cytotoxicity represents one of crucial causes. Apart from recurrence, hepatectomy-induced abdominal adhesion also poses huge clinical challenges such as abdominal pain, intestinal obstruction, and perforation. Evidence demonstrates that radiotherapy can upregulate NK group 2D ligand expression on tumor cells to enhance NK cell cytotoxicity, indicating its great potential of curbing HCC recurrence. Nevertheless, radiotherapy has also been disclosed to incur suppression on NK antitumor cell immunity. Herein, we reveal that glycocholic acid (GCA)/tRNA-derived fragment 5 (tRF5)-GlyGCC signaling axis is activated in mouse HCC model after radiotherapy, which dampens NK cell antitumor immunity to limit therapeutic efficacy. Mechanistically, tRF5-GlyGCC can interact with KDM6B to epigenetically upregulate Runx2 and then transcriptionally activate ITGBL1 and S100A9 expression in HCC cells, which further reduces NK cell cytotoxicity directly and attracts myeloid-derived suppressor cell (MDSC) to inhibit NK cell function indirectly, respectively. Therefore, radiotherapy plus targeting tRF5-GlyGCC may be an optimized postoperative adjuvant therapy against HCC recurrence. Then, a nanocomposite powder is designed for liver-localized delivery of tRF5-GlyGCC inhibitor. After sprayed to liver resection margin of mouse HCC model, this powder can rapidly form an in-situ Janus-adhesive hydrogel, which allows for sustained delivery of tRF5-GlyGCC inhibitor. Importantly, it can synergize with radiotherapy to potentiate NK cell antitumor immunity and prevent HCC recurrence postresection. Moreover, its application to surgical bed also effectively mitigates abdominal adhesion in a rat hepatectomy model. Altogether, our work develops a tRF5-GlyGCC-targeting nanocomposite power for sensitizing radiotherapy to thwart HCC recurrence and preventing abdominal adhesion.

IFN alpha signaling drives hematopoietic stem cells malfunction under acute inflammation

Inflammation stimulation regulates the activity of hematopoietic stem cells (HSCs) through direct-sensing and cytokine-mediation. It is known that HSCs directly sense lipopolysaccharide (LPS), a classical infection-related inflammatory signal, via toll like receptor 4 (TLR4) and subsequently become active. However, the mechanism underlying the activity change of HSCs induced by LPS remains incompletely disclosed. Here we explored that under LPS stimulation, the activation of interferon alpha (IFNα) signal pathway resulted in the activation and exhaustion of HSCs in vitro, indicating HSCs directly responded to LPS through the downstream IFNα signal pathway. We also discovered the increased production of IFNα in mice bone marrow and expression of interferon-α/β receptor (IFNAR) on mice HSCs after LPS stimulation. Creatine, an IFNα inhibitor, could reverse the activation and prevent the exhaustion of HSCs caused by LPS by suppressing the expressions of genes associated with the IFNα signal pathway both in vitro and in vivo. Furthermore, we found that the IFNAR deficiency in mice effectively protected HSCs from activation, elevated apoptosis and impaired reconstitution ability under LPS stimulation in vivo. This finding further supports the notion that LPS activates and injures HSCs indirectly via promoting IFNα secretion in the bone marrow environment. Overall, our findings reveal that LPS causes the injury to HSCs either through direct or cytokine-mediated indirect activation of the IFNα signal pathway.

Candidate approaches for predicting vitiligo recurrence: an effective model and biomarkers

Background

Vitiligo is a challenging chronic condition with unpredictable disease course and high propensity for relapse post-treatment. Recent studies have reported the biomarkers for disease activity, severity, and therapeutic response of vitiligo, yet very few have investigated cytokines as predictive biomarkers for disease recurrence in vitiligo. This study aims to explore cytokines that serve as biomarkers for disease recurrence and extend research on factors related to the disease's activity.

Methods

92 patients and 40 healthy controls were recruited at the Air Force Medical Center from September 20, 2023, to November 30, 2023. Ultrasensitive multiplex cytokine array was used to measure plasma concentrations of cytokines, including IFN-γ, CXCL9, CXCL10, CXCL11, IL-6, and IL-15.

Results

IFN-γ, CXCL9, CXCL10, CXCL11, IL-6, and IL-15 were expressed at higher levels in the circulation of patients with both segmental and non-segmental vitiligo compared to healthy controls (p < 0.001). There were no significant differences in these cytokine levels between the two types of vitiligo. CXCL9 was associated with the activity of vitiligo (p = 0.027). Correlation analysis showed a positive relationship between IFN-γ, CXCL9, CXCL10, CXCL11, IL-6, and IL-15 in the plasma of patients with recurrent vitiligo. The expression of IFN-γ, CXCL9, CXCL10, CXCL11, and IL-6 was significantly higher in recurrent vitiligo than in cases of persistent stable vitiligo (p = 0.001, p = 0.003, p < 0.001, p = 0.002, p = 0.026, respectively), with ROC analysis demonstrating their predictive capability for vitiligo recurrence, with AUC values of 0.806, 0.773, 0.896, 0.785, and 0.709, respectively. Multivariate logistic regression model showed IFN-γ is an independent predictor for vitiligo recurrence [OR (95%CI) =1.051 (1.012~1.116)], with a prediction accuracy of 90.5% (38/42) on the training dataset and 88.9% (16/18) on the testing dataset.

Conclusion

Plasma IFN-γ, CXCL9, CXCL10, CXCL11 and IL-6 might be potential biomarkers for vitiligo recurrence, with CXCL9 also associated with disease activity. Additionally, multivariate logistic regression model demonstrated that IFN-γ is an independent predictor of vitiligo recurrence and the model could be a candidate approach for predicting vitiligo recurrence.

Age-related changes in DNA methylation in a sample of elderly Brazilians

BACKGROUND

Age-related changes in DNA methylation (DNAm) play a critical role in regulating gene expression. However, most epigenome-wide association studies have predominantly focused on individuals of European descent. This study aims to characterize longitudinal changes in DNAm patterns in a cohort of elderly Brazilian participants.

METHODS

DNAm profiles were collected approximately nine years apart from 23 elderly Brazilian individuals using the Illumina Infinium MethyationEPIC BeadChip. Using mixed-effects models, we examined changes in DNAm patterns using both quantitative age and binary timepoint (e.g., baseline vs. follow-up) as predictors of interest to identify differentially methylated positions (DMPs). Significant DMPs were compared with a list of previously identified age-related DMPs. Differentially methylated regions (DMRs) were also identified using DMRcate. Gene ontology (GO) pathway enrichment analyses were performed to explore the functional significance of identified DMPs and DMRs.

RESULTS

Of the 586,229 autosomal probes included in the differential methylation analyses, 2768 significant (FDR < 0.05) age-associated DMPs (aDMPs) and 2757 significant (FDR < 0.05) timepoint-associated DMPs (tpDMPs) were identified. Of the 2768 aDMPs, 1471 were replicated from previous studies. Of the 1297 non-replicated CpGs, 77.4% were exclusive to the EPIC array. The DMR analyses identified 305 age-associated DMRs (aDMRs) and 372 timepoint-associated DMRs (tpDMRs). Both aDMPs and aDMRs exhibited age-related hypermethylation within CpG islands and promoter regions of the genome, whereas hypomethylation predominantly occurred in interCGI and intergenic regions and introns. The GO enrichment analyses identified several neurological and cognition-related pathways enriched for hypermethylated CpG islands, many of which were mapped near transcription start sites and first exon regions.

CONCLUSIONS

This longitudinal study identified age-associated and timepoint-associated DMPs and DMRs in a sample of elderly Brazilians. Most of the non-replicated CpGs were found to be on the new EPIC array, suggesting that more age-related studies using the EPIC array are required to validate these CpGs. The GO pathway enrichment analyses identified age-related enrichment of several gene sets related to cognitive and physical decline in elderly populations. The enrichment of these sites could provide evidence for age-related neurodegeneration and cognitive decline in elderly populations.

Identification of disease-specific gut microbial markers in vitiligo

There is a potential correlation between vitiligo and gut microbiota, although research in this area is currently limited. The research employed high-throughput sequencing of 16S rRNA to examine the gut microbiome in the stool samples of 49 individuals with vitiligo and 49 without the condition. The study encompassed four comparison groups: (1) DI (disease) group vs. HC (healthy control) group; (2) DI_m group (disease group of minors) vs. HC_m group (healthy control group of minors); (3) DI_a group (adult disease group) vs. HC_a group (adult healthy control group); (4) DI_m group vs. DI_a group. Research findings have indicated the presence of spatial heterogeneity in the gut microbiota composition between individuals with vitiligo and healthy controls. A significant reduction in gut microbiota diversity has been observed in vitiligo patients across both minors and adult groups. However, variations have been noted in the composition of disease-related differential microbial markers among different age groups. Specifically, Bacteroides and Parabacteroides have been identified as specific markers of the intestinal microbiota of vitiligo patients in both minor and adult groups. Correlative analyses have revealed a positive correlation of these two genera with the Vitiligo Area Scoring Index (VASI) and disease duration. It is noteworthy that there are no significant differences in diversity between the DI_m group and the DI_a group, with similarities in microbiota composition and functional characteristics. Nevertheless, correlative analyses suggest a declining trend in Bacteroides and Parabacteroides with increasing age. Individuals with vitiligo exhibit distinct features in their gut microbiome when contrasted with those in the healthy control group. Additionally, the microbial marker genera that show variances between patients and healthy controls vary among different age groups. Disease-specific microbial marker genera (Bacteroides and Parabacteroides) are associated with VASI, duration of the condition, and age. These findings are essential for improving early diagnosis and developing potential treatment strategies for individuals with vitiligo.

Sunscreens in pigmentary disorders: time to revise the message

Current sunscreen messaging centres around skin cancer prevention, with an emphasis on mitigating the damaging effects of ultraviolet B (UVB) radiation. Darker skin is believed to be better protected against UVB owing to its higher melanin content, and therefore, this messaging has been largely targeted at people with lighter skin tones. This is reflected by low sunscreen use by people of darker skin types. However, visible light (VL) is now being appreciated as a culprit behind exacerbation of disorders of hyperpigmentation such as melasma and post-inflammatory hyperpigmentation (PIH) which is known to significantly impair quality of life (QoL) of those affected. The role of VL in melanogenesis is not well known to patients nor to dermatologists and is a missed opportunity in the management of pigmentary disorders. We propose that changing the terminology from 'sunscreen' to 'light protection' acknowledges the central role of VL in melanogenesis, underlining the importance of VL protection and making the messaging more inclusive for people of all skin colours.

Aging, brain-derived neurotrophic factor, and allergen-induced pulmonary responses in mice

Asthma in the elderly is being recognized as more severe, resistant to standard therapies, and having greater morbidity. Therefore, it becomes important to understand the impact of aging-associated airway structure and functional changes toward pathogenesis of asthma in the elderly. Here, airway smooth muscle plays important roles in airway hyperreactivity and structural remodeling. The role of smooth muscle in asthma can be modulated by growth factors [including neurotrophins such as brain-derived neurotrophic factor (BDNF)] and proinflammatory senescence factors. In this study, we investigated aging effects on airway hyperreactivity, structural remodeling, inflammation, and senescence in a mouse model of allergic asthma. C57BL/6J wild-type mice or smooth muscle-specific BDNF knockout mice at 4, 18, and 24 mo of age were intranasally exposed to mixed allergens (MAs, ovalbumin, Aspergillus, Alternaria, and house dust mite) over 4 wk. Assessing lung function by flexiVent, we found that compared with 4-mo-old mice, 18- and 24-mo-old C57BL/6J mice showed decreased airway resistance and increased airway compliance after PBS or MA treatment. Deletion of smooth muscle BDNF blunted airway hyperreactivity in aged mice. Lung histology analysis revealed that aging increased bronchial airway thickness and decreased lung inflammation. Multiplex assays showed that aging largely reduced allergen-induced lung expression of proinflammatory chemokines and cytokines. By immunohistochemistry staining, we found that aging increased bronchial airway expression of senescence markers, including p21, phospho-p53, and phospho-γH2A.X. Our data suggest that aging-associated increase of airway senescence in the context of allergen exposure may contribute to asthma pathology in the elderly.NEW & NOTEWORTHY The pathogenesis of asthma in elderly is not well understood. Using a mouse model of asthma, we show that aging results in decreased lung function and less responsiveness to allergen exposure, impacted by locally produced brain-derived neurotrophic factor. Aging also decreases allergen-induced inflammation but increases airway remodeling and senescence. Our results suggest that senescence pathways may contribute to asthma pathogenesis in elderly.

Sunscreen Formula of FeO(OH)·H2O/TiO2 With Spectral Selectivity to Enhance Collagen Biosynthesis via Fibroblast Test

OBJECTIVE

To develop a sunscreen formula with spectral selectivity that filters harmful light (280-550 nm) while allowing beneficial light (550-760 nm) to permeate and thus to boost collagen generation.

METHODS

A variety of sunscreen filters and their combinations were tested for transmittance spectrum. The spectral selectivity was quantified by Selection Index (SI), and the optimal formula was identified. Then, human dermal fibroblasts (HDFs) were subjected to simulated sunlight exposure with the application of this formula. The cell viability and collagen levels were measured post-exposure.

RESULTS

The combination of TiO2 and FeO(OH)·H2O displays spectral selectivity and reaches the optimal SI value at the mixing ratio of 64:36. This mixture, when formulated with traditional UV filters, significantly elevates the level of Collagen I.

CONCLUSION

This work uncovers the influence of spectral selectivity on the enhancement of sunscreen performance and proposes a filter combination with spectral selectivity. This formula, when integrated with conventional UV sunscreens, allows for the beneficial effects of sunlight to be more pronounced. This discovery may provide fresh insights for the design of future sunscreen products.

Deciphering the role of skin aging in pigmentary disorders

Skin aging is a complex biological process involving intrinsic and extrinsic factors. Skin aging contains alterations at the tissue, cellular, and molecular levels. Currently, there is increasing evidence that skin aging occurs not only in time-dependent chronological aging but also plays a role in skin pigmentary disorders. This review provides an in-depth analysis of the impact of skin aging on different types of pigmentary disorders, including both hyperpigmentation disorders such as melasma and senile lentigo and hypopigmentation disorders such as vitiligo, idiopathic guttate hypomelanosis and graying of hair. In addition, we explore the mechanisms of skin aging on pigmentation regulation and suggest several potential therapeutic approaches for skin aging and aging-related pigmentary disorders.