Household laundry detergents disrupt barrier integrity and induce inflammation in mouse and human skin

Virucidal activity of household laundry detergents and additives in simulated wash cycles

AIMS

In this study, we evaluated the antiviral performance of domestic laundry detergents and additives to provide information for selecting a suitable product for reducing viruses on textiles during viral infections at home.

METHODS AND RESULTS

Three laundry heavy-duty detergents (HDDs)-universal solid, regular liquid, and compact single-dose liquid-and a laundry additive (hygiene rinser) were tested for their efficacy using a suspension test and lab-scale laundering against two viruses: enveloped modified vaccinia virus Ankara (MVA) and nonenveloped murine norovirus (MNV). All HDD detergents effectively inactivated MVA at 30°C (titers reduced below quantification limit), whereas the hygiene rinser at 20°C exhibited lower efficacy, with 2.19 log10 reduction after 30 min. Notably, at low temperatures, HDD solid effectively reduced the MNV titer (5 log10 reduction after 30 min).

CONCLUSIONS

Laundry detergents, including HDD liquid detergents, can inactivate MVA at 30°C. However, for complete inactivation of nonenveloped viruses like norovirus, detergents containing bleach, like the universal solid, are required.

EAACI Guidelines on Environmental Science for Allergy and Asthma-Recommendations on the Impact of Indoor Air Pollutants on the Risk of New-Onset Asthma and on Asthma-Related Outcomes

The EAACI Guidelines used the GRADE approach to evaluate the impact of major indoor air pollutants (dampness and mould, cleaning agents, volatile organic compounds and pesticides) on the risk of new-onset asthma and on asthma-related outcomes. The guideline also acknowledges the synergies among indoor air pollutants and other components of the indoor exposome (allergens, viruses, endotoxins). Very low to low certainty of evidence was found for the association between exposure to indoor pollutants and increased risk of new-onset asthma and asthma worsening. Only for mould exposure there was moderate certainty of evidence for new-onset asthma. Due to the quality of evidence, conditional recommendations were formulated on the risk of exposure to all indoor pollutants. Recommendations are provided for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management. For policymakers and regulators this evidence-informed guideline supports setting legally binding standards and goals for indoor air quality at international, national and local levels. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but community and governmental measures for improved indoor air quality are needed to achieve significant impact.

Type 2 immunity in allergic diseases

Significant advancements have been made in understanding the cellular and molecular mechanisms of type 2 immunity in allergic diseases such as asthma, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis (EoE), food and drug allergies, and atopic dermatitis (AD). Type 2 immunity has evolved to protect against parasitic diseases and toxins, plays a role in the expulsion of parasites and larvae from inner tissues to the lumen and outside the body, maintains microbe-rich skin and mucosal epithelial barriers and counterbalances the type 1 immune response and its destructive effects. During the development of a type 2 immune response, an innate immune response initiates starting from epithelial cells and innate lymphoid cells (ILCs), including dendritic cells and macrophages, and translates to adaptive T and B-cell immunity, particularly IgE antibody production. Eosinophils, mast cells and basophils have effects on effector functions. Cytokines from ILC2s and CD4+ helper type 2 (Th2) cells, CD8 + T cells, and NK-T cells, along with myeloid cells, including IL-4, IL-5, IL-9, and IL-13, initiate and sustain allergic inflammation via T cell cells, eosinophils, and ILC2s; promote IgE class switching; and open the epithelial barrier. Epithelial cell activation, alarmin release and barrier dysfunction are key in the development of not only allergic diseases but also many other systemic diseases. Recent biologics targeting the pathways and effector functions of IL4/IL13, IL-5, and IgE have shown promising results for almost all ages, although some patients with severe allergic diseases do not respond to these therapies, highlighting the unmet need for a more detailed and personalized approach.

Meteorin-like protein/METRNL/Interleukin-41 ameliorates atopic dermatitis-like inflammation

BACKGROUND

Meteorin-like protein (METRNL)/Interleukin-41 (IL-41) is a novel immune-secreted cytokine/myokine involved in several inflammatory diseases. However, how METRNL exerts its regulatory properties on skin inflammation remains elusive. This study aims to elucidate the functionality and regulatory mechanism of METRNL in atopic dermatitis (AD).

METHODS

METRNL levels were determined in skin and serum samples from patients with AD and subsequently verified in the vitamin D3 analogue MC903-induced AD-like mice model. The cellular target of METRNL activity was identified by multiplex immunostaining, single-cell RNA-seq and RNA-seq.

RESULTS

METRNL was significantly upregulated in lesions and serum of patients with dermatitis compared to healthy controls (p <.05). Following repeated MC903 exposure, AD model mice displayed elevated levels of METRNL in both ears and serum. Administration of recombinant murine METRNL protein (rmMETRNL) ameliorated allergic skin inflammation and hallmarks of AD in mice, whereas blocking of METRNL signaling led to the opposite. METRNL enhanced β-Catenin activation, limited the expression of Th2-related molecules that attract the accumulation of Arginase-1 (Arg1)hi macrophages, dendritic cells, and activated mast cells.

CONCLUSIONS

METRNL can bind to KIT receptor and subsequently alleviate the allergic inflammation of AD by inhibiting the expansion of immune cells, and downregulating inflammatory gene expression by regulating the level of active WNT pathway molecule β-Catenin.

Epithelial barrier dysfunction, type 2 immune response, and the development of chronic inflammatory diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, humans have been increasingly exposed to substances toxic for epithelial cells, including air pollutants, laundry and dishwashers, household chemicals, toothpaste, food additives, microplastics, and nanoparticles, introduced into our daily lives as part of industrialization, urbanization, and modernization. These substances disrupt the epithelial barriers and lead to microbial dysbiosis and cause immune response to allergens, opportunistic pathogens, bacterial toxins, and autoantigens followed by chronic inflammation due to epigenetic mechanisms. Recent evidence from studies on the mechanisms of epithelial barrier damage has demonstrated that even trace amounts of toxic substances can damage epithelial barriers and induce tissue inflammation. Further research in this field is essential for our understanding of the causal substances and molecular mechanisms involved in the initiation of leaky epithelial barriers that cascade into chronic inflammatory diseases.

Multimodal profiling of biostabilized human skin modules reveals a coordinated ecosystem response to injected mRNA-1273 COVID-19 vaccine

BACKGROUND

The field of drug development is witnessing a remarkable surge in the development of innovative strategies. There is a need to develop technological platforms capable of generating human data prior to progressing to clinical trials.

METHODS

Here we introduce a new flexible solution designed for the comprehensive monitoring of the natural human skin ecosystem's response to immunogenic drugs over time. Based on unique bioengineering to preserve surgical resections in a long survival state, it allows for the first time a comprehensive analysis of resident immune cells response at both organ and single-cell levels.

RESULTS

Upon injection of the mRNA-1273 COVID-19 vaccine, we characterized precise sequential molecular events triggered upon detection of the exogenous substance. The vaccine consistently targets DC/macrophages and mast cells, regardless of the administration route, while promoting specific cell-cell communications in surrounding immune cell subsets.

CONCLUSION

Given its direct translational relevance, this approach provides a multiscale vision of genuine human tissue immunity that could pave the way toward the development of new vaccination and drug development strategies.

Environmental and behavioral mitigation strategies for patients with atopic dermatitis

Objective

Herein, we aimed to summarize the evidence-base for these interventions with a focus on the role of specific chemicals in driving AD.

Methods

A narrative review of nonprescription mitigation strategies in AD was conducted.

Results

We identified avoidance strategies for the various routes of exposure such as air pollution, water contamination, or inclusion in home goods, skin care products, and cleansers. Evidence for and against dietary modification and emollient use as primary prevention were also elucidated. To remember these interventions we propose a mnemonic, HELPSS AD: Home decor, Emollients, Laundering, Probiotics, Soaks, Social support, Air quality, and Diet.

Limitations

Each of these categories presents nuanced molecular differences that must be considered. For example, probiotic responses vary by the specific species while home products and pollution must be analyzed by the specific toxins.

Conclusion

Although the interventions discussed lack the level of evidence required for inclusion into formal guidelines, awareness of these approaches may offer aid to, and build trust with, patients and caregivers.

The epithelial barrier theory and its associated diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Epithelial barrier dysfunction and associated diseases in companion animals: Differences and similarities between humans and animals and research needs

Since the 1960s, more than 350,000 new chemicals have been introduced into the lives of humans and domestic animals. Many of them have become part of modern life and some are affecting nature as pollutants. Yet, our comprehension of their potential health risks for both humans and animals remains partial. The "epithelial barrier theory" suggests that genetic predisposition and exposure to diverse factors damaging the epithelial barriers contribute to the emergence of allergic and autoimmune conditions. Impaired epithelial barriers, microbial dysbiosis, and tissue inflammation have been observed in a high number of mucosal inflammatory, autoimmune and neuropsychiatric diseases, many of which showed increased prevalence in the last decades. Pets, especially cats and dogs, share living spaces with humans and are exposed to household cleaners, personal care products, air pollutants, and microplastics. The utilisation of cosmetic products and food additives for pets is on the rise, unfortunately, accompanied by less rigorous safety regulations than those governing human products. In this review, we explore the implications of disruptions in epithelial barriers on the well-being of companion animals, drawing comparisons with humans, and endeavour to elucidate the spectrum of diseases that afflict them. In addition, future research areas with the interconnectedness of human, animal, and environmental well-being are highlighted in line with the "One Health" concept.

The potential of orally exposed risk factors and constituents aggravating food allergy: Possible mechanism and target cells

Food allergy is a significant concern for the health of humans worldwide. In addition to dietary exposure of food allergens, genetic and environmental factors also play an important role in the development of food allergy. However, only the tip of the iceberg of risk factors in food allergy has been identified. The importance of food allergy caused by orally exposed risk factors and constituents, including veterinary drugs, pesticides, processed foods/derivatives, nanoparticles, microplastics, pathogens, toxins, food additives, dietary intake of salt/sugar/total fat, vitamin D, and therapeutic drugs, are highlighted and discussed in this review. Moreover, the epithelial barrier hypothesis, which is closely associated with the occurrence of food allergy, is also introduced. Additionally, several orally exposed risk factors and constituents that have been reported to disrupt the epithelial barrier are elucidated. Finally, the possible mechanisms and key immune cells of orally exposed risk factors and constituents in aggravating food allergy are overviewed. Further work should be conducted to define the specific mechanism by which these risk factors and constituents are driving food allergy, which will be of central importance to the targeted therapy of food allergy.

Alternative splicing of CARM1 regulated by LincGET-guided paraspeckles biases the first cell fate in mammalian early embryos

The heterogeneity of CARM1 controls first cell fate bias during early mouse development. However, how this heterogeneity is established is unknown. Here, we show that Carm1 mRNA is of a variety of specific exon-skipping splicing (ESS) isoforms in mouse two-cell to four-cell embryos that contribute to CARM1 heterogeneity. Disruption of paraspeckles promotes the ESS of Carm1 precursor mRNAs (pre-mRNAs). LincGET, but not Neat1, is required for paraspeckle assembly and inhibits the ESS of Carm1 pre-mRNAs in mouse two-cell to four-cell embryos. We further find that LincGET recruits paraspeckles to the Carm1 gene locus through HNRNPU. Interestingly, PCBP1 binds the Carm1 pre-mRNAs and promotes its ESS in the absence of LincGET. Finally, we find that the ESS seen in mouse two-cell to four-cell embryos decreases CARM1 protein levels and leads to trophectoderm fate bias. Our findings demonstrate that alternative splicing of CARM1 has an important role in first cell fate determination.

Lifestyle Changes and Industrialization in the Development of Allergic Diseases

PURPOSE OF REVIEW

Modernization and Westernization in industrialized and developing nations is associated with a substantial increase in chronic noncommunicable diseases. This transformation has far-reaching effects on lifestyles, impacting areas such as economics, politics, social life, and culture, all of which, in turn, have diverse influences on public health. Loss of contact with nature, alternations in the microbiota, processed food consumption, exposure to environmental pollutants including chemicals, increased stress and decreased physical activity jointly result in increases in the frequency of inflammatory disorders including allergies and many autoimmune and neuropsychiatric diseases. This review aims to investigate the relationship between Western lifestyle and inflammatory disorders.

RECENT FINDINGS

Several hypotheses have been put forth trying to explain the observed increases in these diseases, such as 'Hygiene Hypothesis', 'Old Friends', and 'Biodiversity and Dysbiosis'. The recently introduced 'Epithelial Barrier Theory' incorporates these former hypotheses and suggests that toxic substances in cleaning agents, laundry and dishwasher detergents, shampoos, toothpastes, as well as microplastic, packaged food and air pollution damage the epithelium of our skin, lungs and gastrointestinal system. Epithelial barrier disruption leads to decreased biodiversity of the microbiome and the development of opportunistic pathogen colonization, which upon interaction with the immune system, initiates local and systemic inflammation. Gaining a deeper comprehension of the interplay between the environment, microbiome and the immune system provides the data to assist with legally regulating the usage of toxic substances, to enable nontoxic alternatives and to mitigate these environmental challenges essential for fostering a harmonious and healthy global environment.

Skin, gut, and lung barrier: Physiological interface and target of intervention for preventing and treating allergic diseases

The epithelial barriers of the skin, gut, and respiratory tract are critical interfaces between the environment and the host, and they orchestrate both homeostatic and pathogenic immune responses. The mechanisms underlying epithelial barrier dysfunction in allergic and inflammatory conditions, such as atopic dermatitis, food allergy, eosinophilic oesophagitis, allergic rhinitis, chronic rhinosinusitis, and asthma, are complex and influenced by the exposome, microbiome, individual genetics, and epigenetics. Here, we review the role of the epithelial barriers of the skin, digestive tract, and airways in maintaining homeostasis, how they influence the occurrence and progression of allergic and inflammatory conditions, how current treatments target the epithelium to improve symptoms of these disorders, and what the unmet needs are in the identification and treatment of epithelial disorders.

Skin Barrier Function Assessment: Electrical Impedance Spectroscopy Is Less Influenced by Daily Routine Activities Than Transepidermal Water Loss

BACKGROUND

Skin barrier function assessment is commonly done by measuring transepidermal water loss (TEWL). An important limitation of this method is the influence of intrinsic and extrinsic factors. Electrical impedance spectroscopy (EIS) is a lesser-established method for skin barrier function assessment. Some influential factors have been described, but no guidelines exist regarding the standardization of these measurements.

OBJECTIVE

To evaluate the effect size of daily routine activities on TEWL and EIS, as well as their correlation with age and anatomical differences.

METHODS

Healthy participants (n=31) were stratified into three age groups (18-29, 30-49, and ≥50 years). In a climate-controlled room, EIS and TEWL measurements were performed on the left and right volar forearm and abdomen.

RESULTS

Body cream application decreased TEWL and EIS values after 15 and 90 minutes. Skin washing decreased TEWL for 15 minutes and EIS values for at least 90 minutes. TEWL was increased 5 minutes after moderate to intense exercise. Coffee intake increased TEWL on the abdomen after 60 minutes. TEWL and EIS values did not correlate with participants' age and no anatomical differences were observed. No correlation was observed between TEWL and EIS.

CONCLUSION

Body cream application and skin washing should be avoided at least 90 minutes prior to measurements of TEWL and EIS. Exercise and coffee intake should also be avoided prior to TEWL measurements. EIS may be a promising tool for skin barrier function assessment as it is less affected by daily routine activities than TEWL.

[Global environmental changes and the epithelial barrier hypothesis]

BACKGROUND

The global burden of noncommunicable diseases (NCD) has seen a strong increase in recent decades and attributable to the influence of environmental factors. For a multitude of diseases an association with epithelial barrier damage has been reported.

OBJECTIVE

This article provides an overview of the health effects of environmental pollution in the context of the epithelial barrier hypothesis of Cezmi Akdis. Additionally, exemplary mechanisms of a barrier damage are described. Finally, possible preventive and therapeutic consequences are discussed.

MATERIAL AND METHODS

The PubMed database was searched for the relevant topics and selected literature was reviewed.

RESULTS

A wide variety of substances can damage the epithelial barriers of the skin, lungs and gastrointestinal tract. The rise in the prevalences of atopic diseases could (partly) be due to an increased exposure to barrier-damaging substances, such as particulate matter and laundry detergents. A possible pathogenetic mechanism is the initiation and maintenance of an immune response by subepithelial penetration of microorganisms through damaged epithelia.

CONCLUSION

Based on the epithelial barrier hypothesis new therapeutic and prevention strategies can be developed. The regulation of hazardous chemicals and the fight against environmental pollution and climate change are necessary to reduce the burden of disease.