Exacerbating factors and disease burden in patients with atopic dermatitis

Defining disease severity in atopic dermatitis and psoriasis for the application to biomarker research: an interdisciplinary perspective

More severe atopic dermatitis and psoriasis are associated with a higher cumulative impact on quality of life, multimorbidity and healthcare costs. Proactive, early intervention in those most at risk of severe disease may reduce this cumulative burden and modify the disease trajectory to limit progression. The lack of reliable biomarkers for this at-risk group represents a barrier to such a paradigm shift in practice. To expedite discovery and validation, the BIOMarkers in Atopic Dermatitis and Psoriasis (BIOMAP) consortium (a large-scale European, interdisciplinary research initiative) has curated clinical and molecular data across diverse study designs and sources including cross-sectional and cohort studies (small-scale studies through to large multicentre registries), clinical trials, electronic health records and large-scale population-based biobanks. We map all dataset disease severity instruments and measures to three key domains (symptoms, inflammatory activity and disease course), and describe important codependencies and relationships across variables and domains. We prioritize definitions for more severe disease with reference to international consensus, reference standards and/or expert opinion. Key factors to consider when analysing datasets across these diverse study types include explicit early consideration of biomarker purpose and clinical context, candidate biomarkers associated with disease severity at a particular point in time and over time and how they are related, taking the stage of biomarker development into account when selecting disease severity measures for analyses, and validating biomarker associations with disease severity outcomes using both physician- and patient-reported measures and across domains. The outputs from this exercise will ensure coherence and focus across the BIOMAP consortium so that mechanistic insights and biomarkers are clinically relevant, patient-centric and more generalizable to current and future research efforts.

Prevalence and coexistence of type 2 inflammatory diseases

BACKGROUND

Type 2 inflammation has been described as a pathophysiological basis common to some diseases, such as atopic dermatitis (AD), chronic rhinosinusitis with nasal polyps, and asthma (CRSwNP).

OBJECTIVE

The present study used population-based prevalence in Catalonia to analyse the coexistence of type 2 inflammatory diseases in patients primarily diagnosed with the above mentioned conditions.

RESULTS

We found a high degree of coexistence of type 2 inflammatory diseases among these patients, with the prevalence being higher in the severe forms, except for AD. For the severe forms of primary diseases, the proportion of patients with coexisting type 2 inflammatory diseases (severe or non-severe) was 16.2% for AD, 19.8% for asthma, and a striking 62.4% for CRSwNP. This patient population has the highest proportion of coexisting type 2 inflammatory diseases, both severe (48.9%) and non-severe (13.5%).

CONCLUSION

Our findings have significant implications for the management of patients with AD, asthma, and CRSwNP.

(S)-(-)-blebbistatin O-benzoate has the potential to improve atopic dermatitis symptoms in NC/Nga mice by upregulating epidermal barrier function and inhibiting type 2 alarmin cytokine induction

Atopic dermatitis is a multi-pathogenic disease characterized by chronic skin inflammation and barrier dysfunction. Therefore, improving the skin's ability to form an epidermal barrier and suppressing the production of cytokines that induce type 2 inflammatory responses are important for controlling atopic dermatitis symptoms. (-)-Blebbistatin, a non-muscle myosin II inhibitor, has been suggested to improve pulmonary endothelial barrier function and control inflammation by suppressing immune cell migration; however, its efficacy in atopic dermatitis is unknown. In this study, we investigated whether (S)-(-)-blebbistatin O-benzoate, a derivative of (-)-blebbistatin, improves dermatitis symptoms in a mite antigen-induced atopic dermatitis model using NC/Nga mice. The efficacy of the compound was confirmed using dermatitis scores, ear thickness measurements, serum IgE levels, histological analysis of lesions, and filaggrin expression analysis, which is important for barrier function. (S)-(-)-Blebbistatin O-benzoate treatment significantly reduced the dermatitis score and serum IgE levels compared to those in the vehicle group (p < 0.05). Furthermore, the histological analysis revealed enhanced filaggrin production and a decreased number of mast cells (p < 0.05), indicating that (S)-(-)-blebbistatin O-benzoate improved atopic dermatitis symptoms in a pathological model. In vitro analysis using cultured keratinocytes revealed increased expression of filaggrin, loricrin, involucrin, and ceramide production pathway-related genes, suggesting that (S)-(-)-blebbistatin O-benzoate promotes epidermal barrier formation. Furthermore, the effect of (S)-(-)-blebbistatin O-benzoate on type 2 alarmin cytokines, which are secreted from epidermal cells upon scratching or allergen stimulation and are involved in the pathogenesis of atopic dermatitis, was evaluated using antigens derived from mite feces. The results showed that (S)-(-)-blebbistatin O-benzoate inhibited the upregulation of these cytokines. Based on the above, (S)-(-)-blebbistatin O-benzoate has the potential to be developed as an atopic dermatitis treatment option that controls dermatitis symptoms by suppressing inflammation and improving barrier function by acting on multiple aspects of the pathogenesis of atopic dermatitis.

An Overview on Atopic Dermatitis, Oxidative Stress, and Psychological Stress: Possible Role of Nutraceuticals as an Additional Therapeutic Strategy

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a considerable impact on patients' quality of life. Its etiology is multifactorial and, among the predisposing factors, a role is played by oxidative stress. Pollution, recurrent infections, and psychological stress contribute to oxidative stress, amplifying the production of proinflammatory cytokines and worsening barrier damage. There are various oxidative stress mechanisms involved in the pathogenesis of AD. Moreover, AD often appears to be associated with psychological disorders such as alexithymia, depression, and anxiety due to severe itching and related insomnia, as well as social distress and isolation. The increasing incidence of AD requires the evaluation of additional therapeutic approaches in order to reduce the psychological burden of this condition. Our review aims to evaluate the role of some nutraceuticals in AD treatment and its related psychological comorbidities. The combination of some natural compounds (flavonoids, alkaloids, terpenes, isothiocyanates) with traditional AD treatments might be useful in improving the effectiveness of therapy, by reducing chronic inflammation and preventing flare-ups, and in promoting corticosteroid sparing. In addition, some of these nutraceuticals also appear to have a role in the treatment of psychological disorders, although the underlying oxidative stress mechanisms are different from those already known for AD.

Supercritical CO2 fluid extract from Stellariae Radix ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis by inhibit M1 macrophages polarization via AMPK activation

Yin chai hu (Radix Stellariae) is a root medicine that is frequently used in Chinese traditional medicine to treat fever and malnutrition. In modern medicine, it has been discovered to have anti-inflammatory, anti-allergic, and anticancer properties. In a previous study, we were able to extract lipids from Stellariae Radix using supercritical CO2 extraction (SRE), and these sterol lipids accounted for up to 88.29% of the extract. However, the impact of SRE on the development of atopic dermatitis (AD) has not yet been investigated. This study investigates the inhibitory effects of SRE on AD development using a 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model. Treatment with SRE significantly reduced the dermatitis score and histopathological changes compared with the DNCB group. The study found that treatment with SRE resulted in a decrease of pro-inflammatory cytokines TNF-α, CXC-10, IL-12, and IL-1β in skin lesions. Additionally, immunohistochemical analysis revealed that SRE effectively suppressed M1 macrophage infiltration into the AD lesion. Furthermore, the anti-inflammatory effect of SRE was evaluated in LPS + INF-γ induced bone marrow-derived macrophages (BMDMs) M1 polarization, SRE inhibited the production of TNF-α, CXC-10, IL-12, and IL-1β and decreased the expression of NLRP3. Additionally, SRE was found to increase p-AMPKT172, but had no effect on total AMPK expression, after administration of the AMPK inhibitor Compound C, the inhibitory effect of SRE on M1 macrophages was partially reversed. The results indicate that SRE has an inhibitory effect on AD, making it a potential therapeutic agent for this atopic disorder.

Ozonated Sunflower Oil (OSO) Alleviates Inflammatory Responses in Oxazolone-Induced Atopic Dermatitis (AD)-Like Mice and LPS-Treated RAW 264.7 Cells

Ozone, a highly reactive oxidant molecule, is widely used as a complementary therapy for various skin diseases, including wound healing, pressure ulcers, diabetic foot, and infections. However, there is limited research on the effectiveness of ozone for atopic dermatitis (AD). Ozonated sunflower oil (OSO) is an active ingredient obtained from partially ozonated sunflower oil (SO). OSO markedly reduced the LPS-induced increase in IL-1β and nitric oxide (NO) levels in RAW 264.7 mouse macrophage cells. Oxazolone (OXZ) was applied to hairless mice to induce AD-like skin symptoms and immune response. OSO significantly alleviated the OXZ-induced increases in the number of infiltrating mast cells, epidermal thickness, AD symptoms, thymic stromal lymphopoietin (TSLP), and filaggrin, as well as the serum levels of NO, IgE, IL-1β, and TNF-α. Furthermore, OSO inhibited the IL-4/STAT3/MAPK pathway and the expression of NF-κB. Our results suggest that OSO treatment could relieve AD-mediated skin damage through its anti-inflammatory and antioxidant activities. Therefore, it can be used as a therapeutic agent against AD-related skin diseases.

Similarities and differences in peripheral itch and pain pathways in atopic dermatitis

Atopic dermatitis (AD) is predominantly characterized by intense itching, but concomitant skin pain is experienced by more than 40% of patients. Patients with AD display considerable somatosensory aberrations, including increased nerve sensitivity to itch stimuli (hyperknesis), perception of itch from innocuous stimuli (alloknesis), or perception of pain from innocuous stimuli (allodynia). This review summarizes the current understanding of the similarities and differences in the peripheral mechanisms underlying itch and pain in AD. These distinct yet reciprocal sensations share many similarities in the peripheral nervous system, including common mediators (such as serotonin, endothelin-1, IL-33, and thymic stromal lymphopoietin), receptors (such as members of the G protein-coupled receptor family and Toll-like receptors), and ion channels for signal transduction (such as certain members of the transient receptor potential [TRP] cation channels). Itch-responding neurons are also sensitive to pain stimuli. However, there are distinct differences between itch and pain signaling. For example, specific immune responses are associated with pain (type 1 and/or type 3 cytokines and certain chemokine C-C [CCL2, CCL5] and C-X-C [CXCL] motif ligands) and itch (type 2 cytokines, including IL-31, and periostin). The TRP melastatin channels TRPM2 and TRPM3 have a role in pain but no known role in itch. Activation of μ-opioid receptors is known to alleviate pain but exacerbate itch. Understanding the connection between itch and pain mechanisms may offer new insights into the treatment of chronic pain and itch in AD.

A Review of Dupilumab in the Treatment of Atopic Dermatitis in Infants and Children

Atopic dermatitis (AD), a common pruritic and chronic inflammatory skin disease, has a major impact on a patient's quality of life. It is characterized by dry, itchy, and eczema-like rashes. AD is more prevalent in young children and has been linked to a variety of other allergy disorders. Traditional drug therapy has certain limitations for treating young children with AD. However, biologics have good clinical application prospects in the medical treatment of young patients. Dupilumab, a fully human monoclonal antibody, specifically binds to the IL-4 Rα subunit, inhibiting IL-4 and IL-13 signaling and blocking the occurrence of type 2 inflammatory response. It has a good effect on treating infants and children with moderate-to-severe AD. This review explores the safety and efficacy of dupilumab in the treatment of AD in infants and children and the impact of early intervention on AD progression, with the aim of informing clinical practice in the use of dupilumab for the treatment of young patients with AD.

The burden of dermatitis from 1990-2019 in the Middle East and North Africa region

BACKGROUND

There are several types of dermatitis, each capable of causing enduring changes that extend beyond physical discomfort. In severe cases, dermatitis can significantly affect mental health, social interactions, and the overall quality of life. This study reports the burden of dermatitis in the Middle East and North Africa (MENA) region from 1990 to 2019, according to sex, age category, and socio-demographic index (SDI).

METHODS

Publicly available data regarding the point prevalence, incidence, and years lived with disability (YLDs) were collected from the Global Burden of Disease 2019 study for both the MENA region and its constituent countries. The point prevalence, incidence, and YLDs of dermatitis were represented as counts and age-standardised rates with 95% uncertainty intervals (UIs).

RESULTS

In 2019, the age-standardised point prevalence of dermatitis was 2744.6 (2517.8-3003.1) per 100,000 population, which was 2.3% lower than in 1990. The YLD rate was 92.3 (55.6-143.4) per 100,000 population, which was 3.1% lower than in 1990. The largest point prevalence rates were observed among those aged 70-74, for both sexes. The 2019 MENA/Global DALY ratio was not above one in any age group for either sex. During the period 1990 to 2019, there was no clear correlation between the burden of dermatitis and the SDI level.

CONCLUSION

The dermatitis burden in the MENA region remained relatively stable from 1990 to 2019. Future prevention efforts should focus on improving healthcare access, health education, and workplace safety regulations.

Disease burden and treatment satisfaction in patients with prurigo nodularis in Japan

Prurigo nodularis (PN) is a chronic inflammatory skin disorder with a high disease burden. In this cross-sectional, web-based survey, Global Questions (GQ), the Numerical Rating Scales (NRS) for pruritus, burning sensation and sleep disturbance, the Short-Form-8 (SF-8) Health Survey, Dermatology Life Quality Index (DLQI), Patient Health Questionnaire 9 (PHQ-9), Work Productivity and Activity Impairment (WPAI), and Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9) scores were used to assess the current disease burden and treatment satisfaction among patients with PN in Japan. In total, 97 patients were included (55.7% male, median age 51 years, median duration of PN 36 months). Based on GQ scores, 35.1% of patients had mild disease, 50.5% moderate, and 14.4% severe disease. Disease burden increased as the severity of PN increased, as indicated by worsening of pruritus NRS scores and quality of life (DLQI, PHQ-9, WPAI presenteeism, work productivity loss, and activity impairment scores). Patients with comorbid atopic dermatitis (AD) also had more intense pruritus than those without AD. Mean ± standard deviation TSQM-9 scores for effectiveness, convenience, and global satisfaction were 54.7 ± 18.1%, 62.4 ± 15.2%, and 57.4 ± 15.9%, respectively. TSQM-9 scores were lowest in patients receiving the most intensive guideline-directed treatment (i.e., topical corticosteroids + systemic oral corticosteroids or cyclosporine), highlighting an unmet need for more effective treatment options for patients with PN. In summary, Japanese patients with PN reported increased disease burden and reduced treatment satisfaction with increased disease severity, despite the use of guideline-recommended therapies.

Cutaneous Components Leading to Pruritus, Pain, and Neurosensitivity in Atopic Dermatitis: A Narrative Review

Atopic dermatitis (AD) is a chronic, relapsing immunoinflammatory skin condition characterized by sensations such as pruritis, pain, and neuronal hypersensitivity. The mechanisms underlying these sensations are multifactorial and involve complex crosstalk among several cutaneous components. This review explores the role these components play in the pathophysiology of atopic dermatitis. In the skin intercellular spaces, sensory nerves interact with keratinocytes and immune cells via myriad mediators and receptors. These interactions generate action potentials that transmit pruritis and pain signals from the peripheral nervous system to the brain. Keratinocytes, the most abundant cell type in the epidermis, are key effector cells, triggering crosstalk with immune cells and sensory neurons to elicit pruritis, pain, and inflammation. Filaggrin expression by keratinocytes is reduced in atopic dermatitis, causing a weakened skin barrier and elevated skin pH. Fibroblasts are the main cell type in the dermis and, in atopic dermatitis, appear to reduce keratinocyte differentiation, further weakening the skin barrier. Fibroblasts and mast cells promote inflammation while dermal dendritic cells appear to attenuate inflammation. Inflammatory cytokines and chemokines play a major role in AD pathogenesis. Type 2 immune responses typically generate pruritis, and the type 1 and type 3 responses generate pain. Type 2 responses and increased skin pH contribute to barrier dysfunction and promote dysbiosis of the skin microbiome, causing the proliferation of Staphyloccocus aureus. In conclusion, understanding the dynamic interactions between cutaneous components in AD could drive the development of therapies to improve the quality of life for patients with AD.

Nursing Interventions for Children with Atopic Dermatitis and Their Families: A Scoping Review

PURPOSE

The purpose of this scoping review was to summarize and synthesis studies about nursing interventions for children and adolescents with atopic dermatitis and their families.

METHODS

A scoping review was conducted and described as per PRISMA-ScR via four electronic databases, PubMed, Web of science, Scopus, and EBSCOhost, evaluating research on nursing interventions for children diagnosed with atopic dermatitis and their families.

RESULTS

Eleven articles were included in the review. Nursing interventions were conducted for children, parents, or both and primarily focused on education, consultation, and management of complications. Outcomes of the interventions showed improvements in atopic dermatitis severity for children and enhanced quality of life for children and their families.

CLINICAL IMPLICATIONS

Nursing interventions targeting children and parents have been found to be effective in alleviating the severity of atopic dermatitis in children and improving their quality of life. Despite the increasing prevalence of atopic dermatitis in children, studies on nursing interventions are insufficient and outdated. Future research should focus on providing comprehensive and age-appropriate interventions for children with atopic dermatitis and their families to improve their well-being and overall quality of life.

Link between obesity and atopic dermatitis: Does obesity predispose to atopic dermatitis, or vice versa?

Two serious health conditions, obesity and atopic dermatitis (AD), share some pathological features such as insulin resistance, leptin resistance and inflammation, and a growing body of evidence suggests a link between obesity and AD. Obesity predisposes an individual to and/or worsens AD, whereas AD increases the risk of obesity. Obesity and AD's interactions are mediated by cytokines, chemokines and immune cells. Obese individuals with AD are more resistant to anti-inflammatory therapy, while weight loss can alleviate AD. In this review, we summarize the evidence linking AD and obesity. We also discuss the pathogenic role of obesity in AD, and vice versa. Because of the connection between these two conditions, mitigation of one could possibly prevent the development of or alleviate the other condition. Effective management of AD and weight loss can enhance the wellness of individuals with both of these conditions. However, proper clinical studies are warranted to validate this speculation.

Once-Daily Crisaborole Ointment, 2%, as a Long-Term Maintenance Treatment in Patients Aged ≥ 3 Months with Mild-to-Moderate Atopic Dermatitis: A 52-Week Clinical Study

BACKGROUND

Topical treatments for atopic dermatitis (AD) used reactively often fail to achieve lasting disease control; many of these therapies are associated with safety concerns that limit long-term use. Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate AD that has potential as a long-term maintenance therapy.

OBJECTIVE

The aim was to evaluate the long-term efficacy and safety of crisaborole once daily (QD) compared to vehicle QD as a maintenance therapy to reduce the incidence of flares in patients with AD who previously responded to crisaborole twice daily (BID).

METHODS

CrisADe CONTROL was a randomized, double-blind, vehicle-controlled, 52-week, phase III study of patients aged ≥ 3 months with mild-to-moderate AD involving ≥ 5% treatable body surface area. Eligible patients received crisaborole BID during an open-label run-in period of up to 8 weeks. Responders were randomly assigned in the double-blind maintenance period to receive either crisaborole QD or vehicle QD. Responders were defined as patients who achieved Investigator's Static Global Assessment (ISGA) success (ISGA score of 0 [clear] or 1 [almost clear] with a ≥ 2-grade improvement) and ≥ 50% improvement in Eczema Area and Severity Index total score (EASI-50) from baseline. Patients who experienced a flare (ISGA score ≥ 2) during the double-blind maintenance period switched to crisaborole BID for up to 12 weeks. During this period, patients were assessed every 4 weeks; if the flare resolved (ISGA score ≤ 1), patients resumed their assigned treatment. The primary endpoint was flare-free maintenance until onset of the first flare. Key secondary endpoints were number of flare-free days, number of flares, and maintenance of pruritus response until onset of the first flare. The incidence of treatment-emergent adverse events was also analyzed.

RESULTS

Overall, 497 patients entered the open-label run-in period with crisaborole BID, of which 270 patients were randomized into the 52-week double-blind maintenance period of the study. Of the 270 patients, 135 were randomly assigned to the crisaborole QD group and 135 were randomly assigned to the vehicle QD group. Median time of flare-free maintenance was longer for patients who received crisaborole versus vehicle (111 vs 30 days, respectively; p = 0.0034). The mean number of flare-free days was higher for patients who received crisaborole versus vehicle (234.0 vs 199.4 days, respectively; p = 0.0346). The mean number of flares was lower for patients who received crisaborole versus vehicle (0.95 vs 1.36, respectively; p = 0.0042). No clear trend was observed in maintenance of pruritus response between crisaborole- and vehicle-treated patients. Crisaborole was well tolerated, with no new or unexpected safety findings when used as maintenance treatment.

CONCLUSIONS

Crisaborole QD was effective and well tolerated for long-term maintenance treatment and flare reduction in adult and pediatric patients with mild-to-moderate AD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04040192, 31 July 2019.

Chronic corticosterone exposure evokes itch hypersensitivity and sexual dysfunction in male rats: relationship between the two distinct gastrin-releasing peptide systems in the spinal cord

In today's society, people are subjected to many social stressors, and excessive chronic stress causes functional disruption of the neuroendocrine system and many diseases. Although the exacerbation of atopic dermatitis with symptoms of itching and erectile dysfunction is induced by chronic stress, the details of the mechanisms are unknown. Here, we examined the effects of chronic stress on itch sensation and male sexual function at the behavioral and molecular levels, focusing on two distinct gastrin-releasing peptide (GRP) systems that independently regulate itch transmission, i.e., the somatosensory GRP system, and male sexual function, i.e., the lumbosacral autonomic GRP system, in the spinal cord. In a rat model of chronic stress induced by chronic corticosterone (CORT) administration, we observed increased plasma CORT concentrations, decreased body weight, and increased anxiety-like behavior, similar to that observed in humans. Chronic CORT exposure induced hypersensitivity to itch and increased the Grp mRNA level in the spinal somatosensory system, but there was no change in pain or tactile sensitivity. Antagonists of the somatosensory GRP receptor, an itch-specific mediator, suppressed itch hypersensitivity induced by chronic CORT exposure. In contrast, chronic CORT exposure decreased male sexual behavior, ejaculated semen volume, vesicular gland weight, and plasma testosterone levels. However, there were no effects on the expression of Grp mRNA or protein in the lumbosacral autonomic GRP system, which regulates male sexual function. In summary, chronic stress model rats showed itch hypersensitivity and impaired sexual function in males, and the involvement of the spinal GRP systems was apparent in itch hypersensitivity.

Endotoxin concentration and persistent eczema in early childhood

Although endotoxin concentration in the environment is negatively associated with atopic dermatitis (AD) onset in early childhood, the association between endotoxin concentration in the environment and eczema resolution in children with preexisting eczema is unclear. The aim of this study was to evaluate the association between endotoxin concentration in house dust and eczema persistence in young children. The authors used data from children participating in JECS (Japan Environment and Children's Study). In children who had AD or AD-like lesions at the age of 1 year, the authors investigated the association between the prevalence of eczema at the age of 3 years and endotoxin concentration (categorized by quartiles) in the dust on children's mattresses at the ages of 1.5 and 3 years. This study included 605 children. Eczema was significantly less prevalent among children whose mattresses were in the second and third quartiles of endotoxin concentration when they were 18 months old than among children whose mattresses were in the first quartile (adjusted odds ratio, 0.57 [95% confidence interval, 0.35-0.93] and adjusted odds ratio, 0.49 [95% confidence interval, 0.29-0.83], respectively). Moreover, of the children with eczema at age 3 years, those whose mattresses had endotoxin concentrations in the first quartile had significantly worse sleep disturbance caused by itchy rash (>1 time per week) than did those whose mattresses were in the third and fourth quartiles (20.0% vs 3.3% and 3.7%, both p values < 0.01). The findings indicate that low endotoxin exposure is associated with a higher prevalence of persistent eczema during early childhood.

Identification of novel candidate genes and predicted miRNAs in atopic dermatitis patients by bioinformatic methods

Atopic dermatitis (AD) is a common, chronic inflammatory dermatosis with relapsing eruptions. Our study used bioinformatics to find novel candidate differentially expressed genes (DEGs) and predicted miRNAs between AD patients and healthy controls. The Mesh term "atopic dermatitis" was retrieved to obtain DEGs in GEO datasets. DEGs between AD patients and healthy controls were analyzed using GEO2R. Overlapping DEGs between different datasets were obtained with use of Draw Venn software. GO and KEGG enrichment analyses were conducted by the use of DAVID. STRING and miRWalk were used to individually analyze PPI networks, interactions of candidate genes and predicted miRNAs. A total of 571 skin samples, as retrieved from 9 databases were assessed. There were 225 overlapping DEGs between lesioned skin samples of AD patients and that of healthy controls. Nineteen nodes and 160 edges were found in the largest PPI cluster, consisting of 17 up-regulated and 2 down-regulated nodes. Two KEGG pathways were identified, including the cell cycle (CCNB1, CHEK1, BUB1B, MCM5) and p53 (CCNB1, CHEK1, GTSE1) pathways. There were 56 nodes and 100 edges obtained in the miRNA-target gene network, with has-miR-17-5p targeted to 4 genes and has-miR-106b-5p targeted to 3 genes. While these findings will require further verification as achieved with experiments involving in vivo and in vitro modles, these results provided some initial insights into dysfunctional inflammatory and immune responses associated with AD. Such information offers the potential to develop novel therapeutic targets for use in preventing and treating AD.

Different molecular weight hyaluronic acid alleviates inflammation response in DNFB-induced mice atopic dermatitis and LPS-induced RAW 264.7 cells

AIMS

Atopic dermatitis (AD) is an inflammatory chronic disease which severely interferes the life of patients. Hence, there is a great need for new therapies. Hyaluronic acid (HA) is an effective potential inflammation modifier; however, there is limited information about their implementation in inflammation therapies. This study aimed to evaluate the anti-inflammatory activities of HA and the influence of its molecular weight.

MAIN METHODS

Male C57BL/6 J mice were stimulated by 2,4-dinitrofluorobenzene to induce AD-like symptoms and immune response. The skin lesions and histopathological change, as well as levels of inflammatory factors were evaluated. RAW 264.7 mouse macrophages were treated with lipopolysaccharides (LPS) to induce inflammation. NO, IL-6, and TNF-α levels were detected through ELISA kits.

KEY FINDINGS

DNFB challenge induced mice AD symptoms including epidermal thickening, mast cell infiltration, Th2/Th1 immune response, skin lesions IL-4 and IFN-γ, and serum IgE elevation. HA treatment ameliorated such symptoms through the inhibition of PI3K/Akt signaling pathway. LPS induction stimulated the secretion of NO, IL-6, and TNF-α in RAW 264.7 cells, while HA pre-treatment reduced the concentration of the cytokines in cell supernatants.

SIGNIFICANCE

These findings give clear insight into the interaction between HA and inflammatory response, which can help guiding the utilization of HA in the AD therapies.