Skin biomarkers predict the development of food allergy in early life

BACKGROUND

Food allergy (FA) often occurs in early childhood with and without atopic dermatitis (AD). FA can be severe and even fatal. For primary prevention, it is important to find early biomarkers to predict the future onset of FA before any clinical manifestations.

OBJECTIVE

Our aim was to find early predictors of future onset of FA in the stratum corneum (SC).

METHODS

Skin tape strips were collected from the forearm of newborns (n = 129) at age 2 months, before any signs of clinical FA or AD. Children were clinically monitored until they reached age 2 years to confirm the presence or absence of FA and AD. Skin tape strips were subjected to lipidomic analyses by liquid chromatography-tandem mass spectrometry and cytokine determination by Meso Scale Discovery U-Plex assay.

RESULTS

Overall, 9 of 129 infants (7.0%) developed FA alone and 9 of 129 infants (7.0%) developed FA concomitantly with AD. In the stratum corneum of children with future FA and concomitant AD and FA, absolute amounts of unsaturated (N24:1)(C18-sphingosine)ceramide and (N26:1)(C18-sphingosine)ceramide and their relative percentages within the molecular group were increased compared with the amounts and percentages in healthy children, with P values ranging from less than .01 to less than .05 according to ANOVA. The children with future AD had normal levels of these molecules. IL-33 level was upregulated in those infants with future FA but not in those with future AD, whereas thymic stromal lymphopoietin was upregulated in those with future AD but not in those with future FA. Logistic regression analysis revealed strong FA predicting power for the combination of dysregulated lipids and cytokines, with an odds ratio reaching 101.4 (95% CI = 5.4-1910.6).

CONCLUSION

Noninvasive skin tape strip analysis at age 2 months can identify infants at risk of FA in the future.

Advanced fructo-oligosaccharides improve itching and aberrant epidermal lipid composition in children with atopic dermatitis

Introduction

The effects of fructo-oligosaccharides (FOS) on atopic dermatitis (AD) have not been determined.

Methods

In a randomized, double-blind, placebo-controlled trial, children with AD aged 24 months to 17 years received either advanced FOS containing 4.25 g of 1-kestose or a placebo (maltose) for 12 weeks.

Results

The SCORAD and itching scores were reduced in patients treated with both FOS (all p < 0.01) and maltose (p < 0.05 and p < 0.01). Sleep disturbance was improved only in the FOS group (p < 0.01). The FOS group revealed a decreased proportion of linoleic acid (18:2) esterified omega-hydroxy-ceramides (EOS-CERs) with amide-linked shorter chain fatty acids (C28 and C30, all p < 0.05), along with an increased proportion of EOS-CERs with longer chain fatty acids (C32, p < 0.01).

Discussion

FOS may be beneficial in alleviating itching and sleep disturbance, as well as improving skin barrier function in children with AD.

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

The impact of temperature on the skin barrier and atopic dermatitis

Climate change is a global threat to public health and causes or worsens various diseases including atopic dermatitis (AD), allergic, infectious, cardiovascular diseases, physical injuries, and mental disorders. The incidence of allergy, such as AD, has increased over the past several decades, and environmental factors such as climate change have been implicated as a potential mechanism. A substantial amount of literature has been published on the impact of climate factors, including cold and hot temperatures, on the skin barrier and AD. Studies in several countries have found a greater incidence of AD in children born in the colder seasons of fall and winter. The effect of cold and warm temperatures on itch, skin flares, increased outpatient visits, skin barrier dysfunction, development of AD, and asthma exacerbations have been reported. Understanding mechanisms by which changes in temperature influence allergies is critical to the development of measures for the prevention and treatment of allergic disorders, such as AD and asthma. Low and high temperatures induce the production of proinflammatory cytokines and lipid mediators such as interleukin-1β, thymic stromal lymphopoietin, and prostaglandin E2, and cause itch and flares by activation of TRPVs such as TRPV1, TRPV3, and TRPV4. TRPV antagonists may attenuate temperature-mediated itch, skin barrier dysfunction, and exacerbation of AD.

Alterations of Epidermal Lipid Profiles and Skin Microbiome in Children With Atopic Dermatitis

PURPOSE

We aimed to investigate epidermal lipid profiles and their association with skin microbiome compositions in children with atopic dermatitis (AD).

METHODS

Specimens were obtained by skin tape stripping from 27 children with AD and 18 healthy subjects matched for age and sex. Proteins and lipids of stratum corneum samples from nonlesional and lesional skin of AD patients and normal subjects were quantified by liquid chromatography tandem mass spectrometry. Skin microbiome profiles were analyzed using bacterial 16S rRNA sequencing.

RESULTS

Ceramides with nonhydroxy fatty acids (FAs) and C18 sphingosine as their sphingoid base (C18-NS-CERs) N-acylated with C16, C18 and C22 FAs, sphingomyelin (SM) N-acylated with C18 FAs, and lysophosphatidylcholine (LPC) with C16 FAs were increased in AD lesional skin compared to those in AD nonlesional skin and that of control subjects (all P < 0.01). SMs N-acylated with C16 FAs were increased in AD lesional skin compared to control subjects (P < 0.05). The ratio of NS-CERs with long-chain fatty acids (LCFAs) to short-chain fatty acids (SCFAs) (C24-32:C14-22), the ratio of LPC with LCFAs to SCFAs (C24-30:C16-22) as well as the ratio of total esterified omega-hydroxy ceramides to total NS-CERs were negatively correlated with transepidermal water loss (rho coefficients = -0.738, -0.528, and -0.489, respectively; all P < 0.001). The proportions of Firmicutes and Staphylococcus were positively correlated to SCFAs including NS ceramides (C14-22), SMs (C17-18), and LPCs (C16), while the proportions of Actinobacteria, Proteobacteria, Bacteroidetes, Corynebacterium, Enhydrobacteria, and Micrococcus were negatively correlated to these SCFAs.

CONCLUSIONS

Our results suggest that pediatric AD skin shows aberrant lipid profiles, and these alterations are associated with skin microbial dysbiosis and cutaneous barrier dysfunction.

Stratum corneum lipid and cytokine biomarkers at age 2 months predict the future onset of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) commonly occurs in children and can progress into severe phenotypes or atopic march, causing significant impairment in quality of life. It is important to find early biomarkers of future onset of AD before any clinical manifestations.

OBJECTIVE

We sought to find early predictors of future onset of AD in skin stratum corneum (SC).

METHODS

Skin tape strips were collected from the forearm of newborns (n = 111) with and without family history of atopic diseases at the age of 2 months before any signs of clinical AD. Children were clinically monitored until they reached age 2 years to ensure the presence or absence of AD. Skin tape strips were subjected to lipidomic analyses by the liquid chromatography electrospray ionization tandem mass spectrometry and cytokine determination by Meso Scale Discovery U-Plex assay.

RESULTS

Overall, 22 of 74 (29.7%) and 5 of 37 (13.5%) infants developed AD in the risk group and the control group, respectively. In the SC of future AD children, protein-bound ceramides were decreased (P < .001), whereas unsaturated sphingomyelin species (P < .0001) and "short-chain" nonhydroxy fatty acid sphingosine and alpha-hydroxy fatty acid sphingosine ceramides were elevated (P < .01 and .05, respectively) as compared with healthy children. Thymic stromal lymphopoietin and IL-13 levels were increased in the SC of future AD subjects (by 74.5% and 78.3%, P = .0022 and P < .0001, respectively). Multivariable logistic regression analysis revealed strong AD predicting power of the combination of family history, type 2 cytokines, and dysregulated lipids, with an odds ratio reaching 54.0 (95% CI, 9.2-317.5).

CONCLUSIONS

Noninvasive skin tape strip analysis at age 2 months can identify asymptomatic children at risk of future AD development with a high probability.

Staphylococcus aureus causes aberrant epidermal lipid composition and skin barrier dysfunction

BACKGROUND

Staphylococcus (S) aureus colonization is known to cause skin barrier disruption in atopic dermatitis (AD) patients. However, it has not been studied how S. aureus induces aberrant epidermal lipid composition and skin barrier dysfunction.

METHODS

Skin tape strips (STS) and swabs were obtained from 24 children with AD (6.0 ± 4.4 years) and 16 healthy children (7.0 ± 4.5 years). Lipidomic analysis of STS samples was performed by mass spectrometry. Skin levels of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) were evaluated. The effects of MSSA and MRSA were evaluated in primary human keratinocytes (HEKs) and organotypic skin cultures.

RESULTS

AD and organotypic skin colonized with MRSA significantly increased the proportion of lipid species with nonhydroxy fatty acid sphingosine ceramide with palmitic acid ([N-16:0 NS-CER], sphingomyelins [16:0-18:0 SM]), and lysophosphatidylcholines [16:0-18:0 LPC], but significantly reduced the proportion of corresponding very long-chain fatty acids (VLCFAs) species (C22-28) compared to the skin without S. aureus colonization. Significantly increased transepidermal water loss (TEWL) was found in MRSA-colonized AD skin. S. aureus indirectly through interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, and IL-33 inhibited expression of fatty acid elongase enzymes (ELOVL3 and ELOVL4) in HEKs. ELOVL inhibition was more pronounced by MRSA and resulted in TEWL increase in organotypic skin.

CONCLUSION

Aberrant skin lipid profiles and barrier dysfunction are associated with S. aureus colonization in AD patients. These effects are attributed to the inhibition of ELOVLs by S. aureus-induced IL-1β, TNF-α, IL-6, and IL-33 seen in keratinocyte models and are more prominent in MRSA than MSSA.

Prior activation of social work team process by pre-admission one-click automatic referral system

Background

Coronary artery disease (CAD) is the leading global cause of mortality. Coronary angiography (CAG) is often performed for CAD patients, and the mean length of stay (LoS) is 4 d. Requests to the social work team (SWT) are often delayed until just before discharge, causing unnecessarily prolonged LoS and reduced chances of obtaining financial support. If the SWT’s support system is activated beforehand for scheduled CAGs, the LoS would be shorter and patients would be relieved of emotional and financial burdens.

Methods

Collaborating with the cardiology and medical informatics departments, a one-click automatic referral system (OARS) was set up (January-May 2021). When cardiologists scheduled a CAG in the outpatient department, an OARS cue popped automatically for the medical aid recipients. The cardiologists could also activate the pre-admission OARS for other patients when necessary. Subsequently, the SWT responded on that day to discuss initiating the financial support process with the candidates. The rate of cardiologists’ pre-admission referral to SWT, decision-making time on financial support provision, and proportion of patients receiving financial support were compared before and after initiating OARS.

Results

After initiating pre-admission OARS, the rate of cardiologists’ pre-admission referral to SWT increased from 17.8% (18/101: mean age, 64.6±12.0 y; 32 females; January-December 2020) to 59.1% (55/93: mean age, 64.0±11.8 y; 29 females; June-December 2021) (p &lt; 0.001). Although the decision-making time to provide financial support did not change significantly (8.4±11.1 vs. 4.7±11.6 d; p = 0.96), the proportion of patients receiving financial support increased (45.5% [46/101] vs. 60.2% [56/93]; p = 0.045).

Conclusions

By enhancing the cardiologists’ pre-admission referral to SWT and success rate of receiving financial support, the proactive strategy of pre-admission OARS benefits CAD patients scheduled for CAG.

Key messages

• By building a proactive referral strategy of pre-admission OARS, more CAD patients scheduled for CAG could obtain timely financial support and be relieved both emotionally and financially by the SWT.

• This pre-admission OARS might be incorporated for more disease entities for patients in need.

Transient Receptor Potential Vanilloid 1 Plays a Major Role in Low Temperature-Mediated Skin Barrier Dysfunction

BACKGROUND

Children born in the fall and winter are at increased risk for developing atopic dermatitis (AD) and food allergy (FA). Since these seasons are associated with low temperature, we hypothesized that low temperature exposure may compromise keratinocyte differentiation and contribute to skin barrier dysfunction.

OBJECTIVE

To examine whether low temperature causes skin barrier dysfunction.

METHODS

Primary human epidermal keratinocytes (HEKs) were differentiated in 1.3mM CaCl₂ media and cultured at different temperatures. The cells were transfected with transient receptor potential cation channel subfamily V member 1 (TRPV1) or signal transducer and activator of transcription (STAT) 3 small-interfering RNA (siRNA) to examine the effects of these gene targets in HEKs exposed to low temperature. Gene expression of TRPV1, epidermal barrier proteins, and keratinocyte-derived cytokines were evaluated. Organotypic skin equivalents were generated using HEKs transfected with control or TRPV1 siRNA and grown at 25^oC or 37^oC. Transepidermal water loss (TEWL) and levels of epidermal barrier proteins were evaluated.

RESULTS

Filaggrin (FLG) and loricrin (LOR) expression, but not keratin (KRT)-1 and KRT-10 expression, was downregulated in HEKs incubated at 25^oC while TRPV1 silencing increased intracellular Ca²⁺ influx (keratinocyte differentiation signal) and enhanced the expression of epidermal differentiation proteins. Interleukin (IL)-1β and thymic stromal lymphopoietin (TSLP) induced by low temperature inhibited FLG expression in keratinocytes through the TRPV1/STAT3 pathway. Moreover, low temperature-mediated inhibition of FLG and LOR was recovered, and TEWL was decreased in organotypic skin transfected with TRPV1 siRNA.

CONCLUSION

TRPV1 is critical in low temperature-mediated skin barrier dysfunction. Low temperature exposure induced TSLP, an alarmin implicated in epicutaneous allergen sensitization.

CLINICAL IMPLICATIONS

Low temperature causes skin barrier dysfunction through TRPV1 and TSLP, which may explain the pathways involved in promoting allergic sensitization through the skin.

Origin of Allergy From In Utero Exposures to the Postnatal Environment

As the incidence of atopic conditions continues to increase, emphasis has been placed on understanding the origin of allergy with hope that prevention measures can be achieved. The perinatal environment is important for this understanding, given that both the immune system and microbiome start forming prenatally. Maternal exposure can greatly impact on fetal health. Additionally, the dysfunctional epithelial barrier is influential in allowing allergens and irritants to penetrate the skin or mucosa, leading to the release of proinflammatory cytokines and mediators to drive type 2 tissue inflammation and the onset of allergy. There are numerous factors related to skin, airway, and gut epithelial barriers dysfunction, and genetic predispositions are also present. Comprehensive birth cohort studies and further mechanistic studies will be keys to understanding the origin of allergy.

Bifidobacterium longum and Galactooligosaccharide Improve Skin Barrier Dysfunction and Atopic Dermatitis-like Skin

Purpose

The beneficial effects of a combination therapy using Bifidobacterium longum and galactooligosaccharide (GOS) for the treatment of atopic dermatitis (AD) have not been elucidated.

Methods

Gene expressions of interleukin (IL)-4 and IL-13 from peripheral blood mononuclear cells and fecal abundance of B. longum from 12-month-old infants were evaluated. Human primary epidermal keratinocytes (HEKs) and hairless mice were treated with B. longum, GOS, B. longum-derived extracellular vesicles (BLEVs), dinitrochlorobenzene (DNCB), or a synbiotic mixture of B. longum and GOS. Expression of epidermal barrier proteins and cytokines as well as serum immunoglobulin E (IgE) levels were analyzed in HEKs and mice. Dermatitis scores, transepidermal water loss (TEWL), epidermal thickness, and fecal B. longum abundance were evaluated in mice.

Results

Fecal abundance of B. longum was negatively correlated with blood IL-13 expression in infants. B. longum or BLEVs increased expression of filaggrin (FLG) and loricrin (LOR) in HEKs. B. longum increased the efficacy of GOS to upregulate FLG and LOR expressions in HEKs. Oral administration of GOS increased fecal abundance of B. longum in mice. Oral administration of B. longum attenuated DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, and deficiency of epidermal barrier proteins. Moreover, the combination of B. longum and GOS showed greater effects to improve DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, serum IgE levels, IL-4 over-expression, and the deficiency of epidermal barrier proteins than the administration of B. longum alone.

Conclusions

B. longum and GOS improve DNCB-induced skin barrier dysfunction and AD-like skin.

Particulate matter causes skin barrier dysfunction

The molecular mechanisms that underlie the detrimental effects of particulate matter (PM) on skin barrier function are poorly understood. In this study, the effects of PM_2.5 on filaggrin (FLG) and skin barrier function were investigated in vitro and in vivo. The levels of FLG degradation products, including pyrrolidone carboxylic acid, urocanic acid (UCA), and cis/trans-UCA, were significantly decreased in skin tape stripping samples of study subjects when they moved from Denver, an area with low PM_2.5, to Seoul, an area with high PM_2.5 count. Experimentally, PM_2.5 collected in Seoul inhibited FLG, loricrin, keratin-1, desmocollin-1, and corneodesmosin but did not modulate involucrin or claudin-1 in keratinocyte cultures. Moreover, FLG protein expression was inhibited in human skin equivalents and murine skin treated with PM_2.5. We demonstrate that this process was mediated by PM_2.5-induced TNF-α and was aryl hydrocarbon receptor dependent. PM_2.5 exposure compromised skin barrier function, resulting in increased transepidermal water loss, and enhanced the penetration of FITC-dextran in organotypic and mouse skin. PM_2.5-induced TNF-α caused FLG deficiency in the skin and subsequently induced skin barrier dysfunction. Compromised skin barrier due to PM_2.5 exposure may contribute to the development and the exacerbation of allergic diseases such as atopic dermatitis.

Recent advances in atopic dermatitis

The prevalence and disease burden of atopic dermatitis (AD) is substantial. AD causes significant impairment in quality of life. It is also associated with mental disorders as well as cardiovascular diseases. Many factors including race, environment, skin barrier dysfunction, immune regulatory abnormalities, and microbiome have been reported to affect the pathophysiology of AD. A variety of cell types including Th2, Th17, Th22, and type 2 innate lymphoid cells contribute to AD. Cytokines from these immune cells cause abnormal epidermal differentiation and skin barrier dysfunction. Moreover, microbial dysbiosis and deficiency of antimicrobial peptides result in Staphylococcus aureus infection. Recently, new drugs have been successfully launched to target polarized immune pathways that lead to moderate-to-severe AD.

Side-by-Side Comparison of Skin Biopsies and Skin Tape Stripping Highlights Abnormal Stratum Corneum in Atopic Dermatitis

Skin biopsies are commonly used for the assessment of skin pathology in various skin diseases, including atopic dermatitis (AD). However, because of the invasive nature of skin biopsies, many patients, particularly children, decline participation. This can lead to potential subject sampling bias as data could be skewed toward more severe, older patients who are willing to have biopsies. Recently, researchers have begun studying the skin with a minimal, noninvasive technique using skin tape stripping (STS) to profile the epidermal transcriptome, proteins, and lipids in the skin. However, side-by-side comparisons of skin biopsies with STS have not been done to assess epidermal penetration. Therefore, 20 STS were collected from the volar surface of forearms from healthy nonatopic subjects and patients with AD, following this skin biopsies were collected from adjacent nontaped and taped areas of the skin. Using hematoxylin and eosin staining and immunostaining, we demonstrated that 20 STS reached the upper granular layer of the epidermis. Additionally, we found that the expression of terminal differentiation markers in samples from STS procedure positively correlated with the expression level of these markers in matching skin biopsies. Therefore, STS is a noninvasive and reliable approach to evaluate the expression of skin terminal differentiation markers, which are defective in AD skin.

[Dynamics of brain CD68+ and stabilin-1+ macrophage infiltration in patients with myocardial infarction]

Te aim of the study was to evaluate the temporal dynamics of brain CD68+ and stabilin-1+ macrophage infltration in patients with fatal myocardial infarction (MI) type 1.

MATERIALS AND METHODS

Te study included 31 patients with fatal MI type I. Te control group comprised 10 patients of 18-40 age group who died from injuries incompatible with life. Patients with MI were divided into two groups. Group 1 comprised patients who died during the frst 72 hours of MI, group 2 comprised patients who died on days 4‒28. Macrophage infltration in the brain was assessed by immunohistochemical analysis. We used CD68 as a marker for the cells of the macrophage lineage and stabilin-1 as an M2-like macrophage biomarker.

RESULTS

In group 1 the number of brain CD68+ macrophages was signifcantly higher than in the control group. In group 2 the intensity of brain CD68+ cells infltration was lower than in group 1 and higher than in the control group. Tere was a small amount of stabilin-1+ macrophages in the brain of healthy people, as well as of patients who died from MI. Tere were no signifcant differences in the number of stabilin-1+ cells between group 1 and group 2. Correlation analysis revealed the presence of positive correlation between the number of CD68 + macrophages in the infarct, peri-infarct, and non-infarct areas of the myocardium and the number of CD68+ macrophages in the brain in patients with MI. Tere were not correlations between the number of CD68 + and stabilin-1+ cells and the presence of diabetes mellitus, history of stroke, history of MI, and pre-infarction angina.

CONCLUSION

Te number of brain CD68+ macrophages signifcantly increased during the frst three days of MI. Te number of brain stabilin-1+ macrophages did not increase and did not differ from the control values. We observed a positive correlation between the number of CD68+ macrophages in the brain and myocardium.

Pathophysiology of atopic dermatitis: Clinical implications

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Genetic predisposition, epidermal barrier disruption, and dysregulation of the immune system are some of the critical components of AD. An impaired skin barrier may be the initial step in the development of the atopic march as well as AD, which leads to further skin inflammation and allergic sensitization. Type 2 cytokines as well as interleukin 17 and interleukin 22 contribute to skin barrier dysfunction and the development of AD. New insights into the pathophysiology of AD have focused on epidermal lipid profiles, neuroimmune interactions, and microbial dysbiosis. Newer therapeutic strategies focus on improving skin barrier function and targeting polarized immune pathways found in AD. Further understanding of AD pathophysiology will allow us to achieve a more precision medicine approach to the prevention and the treatment of AD.

Interactions Between Atopic Dermatitis and Staphylococcus aureus Infection: Clinical Implications

Staphylococcus aureus commonly colonizes the skin of atopic dermatitis (AD) patients and contributes to the development and exacerbation of AD. Multiple factors are associated with colonization of AD skin by S. aureus, including the strength of S. aureus-corneocyte adhesion, deficiency of antimicrobial peptides, decreased levels of filaggrin and filaggrin degradation products, overexpressed Th2/Th17 cytokines, microbial dysbiosis and altered lipid profiles. S. aureus colonization on AD skin causes skin barrier dysfunction through virulence factors such as superantigens (toxins), enzymes and other proteins. Furthermore, colonization of AD skin by S. aureus exacerbates AD and may contribute to microbial dysbiosis, allergen sensitization, Th2/Th17 polarization, development of atopic march and food allergy in AD patients. Skin colonization of S. aureus, particularly methicillin-resistant S. aureus (MRSA), is one of the major challenges commonly encountered in the management of AD. Bleach bath, and topical or systemic antibiotics could be used to control S. aureus infection on AD skin. However, careful use of antibiotics is required to control the occurence of MRSA. Recently, various strategies, including microbiome transplant, monoclonal antibodies against virulent toxins, vaccines and recombinant phage endolysin, have been studied to control S. aureus infection on AD skin. Further advances in our understanding of S. aureus could provide us with ways to manage S. aureus colonization more effectively in AD patients.

Expression and function of the ectopic olfactory receptor OR10G7 in patients with atopic dermatitis

BACKGROUND

Ectopic olfactory receptors (ORs) are found in the skin, but their expression and biological function in normal skin and skin form patients with atopic dermatitis (AD) are unknown.

OBJECTIVES

We sought to characterize the expression of ORs in the skin and assess OR-mediated biological responses of primary human keratinocytes in the presence of odorant ligands.

METHODS

OR expression was examined by using whole-transcriptome sequencing of skin tape strips collected from patients with AD and healthy control (HC) subjects. OR10G7 and filaggrin 1 (FLG-1) expression was analyzed by using RT-PCR and immunostaining in skin biopsy specimens and primary human keratinocytes from patients with AD and HC subjects. ATP and cyclic AMP production by control and OR10G7 small interfering RNA-transfected keratinocytes in response to odorant stimulation with acetophenone and eugenol was assessed.

RESULTS

A total of 381 OR gene transcripts were detected in the skin samples, with the greatest OR expression detected in the skin tape strips corresponding to the upper granular layer of the skin. OR10G7 expression was significantly increased in skin biopsy specimens from patients with AD compared with those from HC subjects (P = .01) and inversely correlated with FLG-1 expression (P = .009). OR10G7 expression was greatest in undifferentiated keratinocytes from patients with AD and was downregulated with progressive differentiation. Primary human keratinocytes produced ATP, an essential neurotransmitter in sensory pathways, in response to acetophenone and eugenol, odorants previously identified as potential ligands for this receptor. This response was abolished in OR10G7 small interfering RNA-transfected keratinocytes.

CONCLUSIONS

OR10G7 is expressed at significantly greater levels in undifferentiated keratinocytes from patients with AD compared with HC subjects. OR10G7 is likely involved in transmission of skin-induced chemosensory responses to odorant stimulation, which might modulate differential nociceptive responses in AD skin.

Significance of Skin Barrier Dysfunction in Atopic Dermatitis

The epidermis contains epithelial cells, immune cells, and microbes which provides a physical and functional barrier to the protection of human skin. It plays critical roles in preventing environmental allergen penetration into the human body and responsing to microbial pathogens. Atopic dermatitis (AD) is the most common, complex chronic inflammatory skin disease. Skin barrier dysfunction is the initial step in the development of AD. Multiple factors, including immune dysregulation, filaggrin mutations, deficiency of antimicrobial peptides, and skin dysbiosis contribute to skin barrier defects. In the initial phase of AD, treatment with moisturizers improves skin barrier function and prevents the development of AD. With the progression of AD, effective topical and systemic therapies are needed to reduce immune pathway activation and general inflammation. Targeted microbiome therapy is also being developed to correct skin dysbiosis associated with AD. Improved identification and characterization of AD phenotypes and endotypes are required to optimize the precision medicine approach to AD.

Minimally invasive skin tape strip RNA sequencing identifies novel characteristics of the type 2-high atopic dermatitis disease endotype

BACKGROUND

Expression profiling of skin biopsy specimens has established molecular features of the skin in patients with atopic dermatitis (AD). The invasiveness of biopsies has prevented their use in defining individual-level AD pathobiological mechanisms (endotypes) in large research studies.

OBJECTIVE

We sought to determine whether minimally invasive skin tape strip transcriptome analysis identifies gene expression dysregulation in AD and molecular disease endotypes.

METHODS

We sampled nonlesional and lesional skin tape strips and biopsy specimens from white adult patients with AD (18 male and 12 female patients; age [mean ± SE], 36.3 ± 2.2 years) and healthy control subjects (9 male and 16 female subjects; age [mean ± SE], 34.8 ± 2.2 years). AmpliSeq whole-transcriptome sequencing was performed on extracted RNA. Differential expression, clustering/pathway analyses, immunostaining of skin biopsy specimens, and clinical trait correlations were performed.

RESULTS

Skin tape expression profiles were distinct from skin biopsy profiles and better sampled epidermal differentiation complex genes. Skin tape expression of 29 immune and epidermis-related genes (false discovery rate < 5%) separated patients with AD from healthy subjects. Agnostic gene set analyses and clustering revealed 50% of patients with AD exhibited a type 2 inflammatory signature (type 2-high endotype) characterized by differential expression of 656 genes, including overexpression of IL13, IL4R, CCL22, CCR4 (log₂ fold change = 5.5, 2.0, 4.0, and 4.1, respectively) and at a pathway level by T_H2/dendritic cell activation. Both expression and immunostaining of skin biopsy specimens indicated this type 2-high group was enriched for inflammatory, type 2-skewed dendritic cells expressing FcεRI. The type 2-high endotype group exhibited more severe disease by using both the Eczema Area and Severity Index score and body surface area covered by lesions.

CONCLUSION

Minimally invasive expression profiling of nonlesional skin reveals stratification in AD molecular pathology by type 2 inflammation that correlates with disease severity.

Skin Wound Healing Is Accelerated by a Lipid Mixture Representing Major Lipid Components of Chamaecyparis obtusa Plant Extract

In chronic nonhealing wounds, the healing process is disrupted and wounds are often infected with bacteria. About 85% of lower extremity amputations in diabetes are attributed to deep infection of foot ulcers. Therefore, infection control is critical for wound care. In this study, we analyzed lipid composition of Chamaecyparis obtusa extract, and we describe the wound-healing properties of its combination of 10 major lipid components. A 10-lipid mixture up-regulated HBD-3 and LL-37 through the olfactory receptor 2AT4 and induced phosphorylation of extracellular signal-regulated kinases and p38 mitogen-activated protein kinases in primary human keratinocytes. In addition, the 10-lipid mixture had direct bactericidal effects against Staphylococcus aureus and Streptococcus pyogenes and protected against staphylococcal α-toxin-induced keratinocyte cell death. In an animal model, the 10-lipid mixture accelerated skin wound healing and was also effective in healing wounds superinfected with S. aureus. We suggest that the 10-lipid mixture, because of its wound-healing and antimicrobial properties, can be beneficial for wound treatment.

Increased epidermal filaggrin in chronic idiopathic urticaria is associated with severity of urticaria

BACKGROUND

Chronic idiopathic urticaria (CIU) and atopic dermatitis (AD) are common allergic skin diseases associated with severe pruritus. AD skin is characterized by filaggrin deficiency, but it has not been studied in CIU.

OBJECTIVE

To compare the expression of filaggrin in skin from patients with CIU, patients with AD, and normal controls and to investigate whether altered filaggrin expression is associated with CIU severity.

METHODS

Skin biopsies were obtained from 16 patients with CIU, 11 patients with AD, and 14 normal controls. Filaggrin expression was evaluated using real-time reverse transcriptase polymerase chain reaction and immunostaining. Urticaria activity score, transepidermal water loss, and skin pH were measured.

RESULTS

FLG gene expression was significantly greater in lesional CIU skin compared with lesional AD skin (P < .01). The staining intensity of filaggrin was significantly increased in lesional CIU skin compared with skin from normal controls (P < .01) and lesional AD skin (P < .001). A significant correlation was observed between filaggrin staining intensity and urticaria activity score in patients with CIU (r = 0.538, P < .05). Transepidermal water loss was significantly increased in lesional skin of patients with AD compared with skin from normal controls (P < .01) and lesional skin from patients with CIU (P < .01). Skin pH was significantly decreased in lesional skin from patients with CIU compared with skin from normal controls (P < .01) and patients with AD (P < .001).

CONCLUSION

Filaggrin is overexpressed in lesional CIU skin, and increased filaggrin expression is positively correlated with urticaria severity in CIU. Altered filaggrin expression has physiologic effects on transepidermal water loss and pH in the skin of patients with CIU, suggesting increased barrier function compared with skin from patients with AD.

IL-25 enhances HSV-1 replication by inhibiting filaggrin expression, and acts synergistically with Th2 cytokines to enhance HSV-1 replication

Atopic dermatitis (AD) is characterized by epidermal barrier defects and recurrent microbial skin infections. AD patients with a history of eczema herpeticum (ADEH+) have more severe skin disease and more highly T helper type 2 (Th2)-polarized immune responses as compared with uncomplicated AD (ADEH-). However, the mechanisms linking epidermal barrier defects and viral skin infection are not well understood. Recently, it has been reported that interleukin-25 may play a role in augmenting Th2 responses. We examined protein expression of IL-25 in the skin biopsies from normal subjects (n=10), ADEH- (n=18), ADEH+ (n=7), and psoriasis (n=9). IL-25 expression was increased in the skin from ADEH-, ADEH+, and psoriasis as compared with normal skin, and was significantly greater in lesional ADEH+ skin than in lesional ADEH- skin. Importantly, we demonstrated that IL-25 enhances herpes simplex virus (HSV)-1 and vaccinia virus replication by inhibiting filaggrin expression, and IL-25 acts synergistically with IL-4 and IL-13 to enhance HSV-1 replication in vitro. In contrast, IFN-γ inhibited HSV-1 replication in vitro. In addition, we demonstrate that filaggrin is a critical protein to inhibit HSV-1 replication because filaggrin small interfering RNA knockdown enhances HSV-1 replication in vitro. Filaggrin breakdown products, however, inhibited HSV-1 replication in vitro.

Filaggrin-dependent secretion of sphingomyelinase protects against staphylococcal α-toxin-induced keratinocyte death

BACKGROUND

The skin of patients with atopic dermatitis (AD) has defects in keratinocyte differentiation, particularly in expression of the epidermal barrier protein filaggrin. AD skin lesions are often exacerbated by Staphylococcus aureus-mediated secretion of the virulence factor α-toxin. It is unknown whether lack of keratinocyte differentiation predisposes to enhanced lethality from staphylococcal toxins.

OBJECTIVE

We investigated whether keratinocyte differentiation and filaggrin expression protect against cell death induced by staphylococcal α-toxin.

METHODS

Filaggrin-deficient primary keratinocytes were generated through small interfering RNA gene knockdown. RNA expression was determined by using real-time PCR. Cell death was determined by using the lactate dehydrogenase assay. Keratinocyte cell survival in filaggrin-deficient (ft/ft) mouse skin biopsies was determined based on Keratin 5 staining. α-Toxin heptamer formation and acid sphingomyelinase expression were determined by means of immunoblotting.

RESULTS

We found that filaggrin expression, occurring as the result of keratinocyte differentiation, significantly inhibits staphylococcal α-toxin-mediated pathogenicity. Furthermore, filaggrin plays a crucial role in protecting cells by mediating the secretion of sphingomyelinase, an enzyme that reduces the number of α-toxin binding sites on the keratinocyte surface. Finally, we determined that sphingomyelinase enzymatic activity directly prevents α-toxin binding and protects keratinocytes against α-toxin-induced cytotoxicity.

CONCLUSIONS

The current study introduces the novel concept that S aureus α-toxin preferentially targets and destroys filaggrin-deficient keratinocytes. It also provides a mechanism to explain the increased propensity for S aureus-mediated exacerbation of AD skin disease.

Staphylococcus aureus α-toxin modulates skin host response to viral infection

BACKGROUND

Patients with atopic dermatitis (AD) with a history of eczema herpeticum have increased staphylococcal colonization and infections. However, whether Staphylococcus aureus alters the outcome of skin viral infection has not been determined.

OBJECTIVE

We investigated whether S aureus toxins modulated host response to herpes simplex virus (HSV) 1 and vaccinia virus (VV) infections in normal human keratinocytes (NHKs) and in murine infection models.

METHODS

NHKs were treated with S aureus toxins before incubation of viruses. BALB/c mice were inoculated with S aureus 2 days before VV scarification. Viral loads of HSV-1 and VV were evaluated by using real-time PCR, a viral plaque-forming assay, and immunofluorescence staining. Small interfering RNA duplexes were used to knockdown the gene expression of the cellular receptor of α-toxin, a disintegrin and metalloprotease 10 (ADAM10). ADAM10 protein and α-toxin heptamers were detected by using Western blot assays.

RESULTS

We demonstrate that sublytic staphylococcal α-toxin increases viral loads of HSV-1 and VV in NHKs. Furthermore, we demonstrate in vivo that the VV load is significantly greater (P < .05) in murine skin inoculated with an α-toxin-producing S aureus strain compared with murine skin inoculated with the isogenic α-toxin-deleted strain. The viral enhancing effect of α-toxin is mediated by ADAM10 and is associated with its pore-forming property. Moreover, we demonstrate that α-toxin promotes viral entry in NHKs.

CONCLUSION

The current study introduces the novel concept that staphylococcal α-toxin promotes viral skin infection and provides a mechanism by which S aureus infection might predispose the host toward disseminated viral infections.

Epidermal barrier in atopic dermatitis

Atopic dermatitis (AD) is a complex disease that affects up to 20% of children and impacts the quality of patients and families in a significant manner. New insights into the pathophysiology of AD point to an important role of structural abnormalities in the epidermis combined with immune dysregulation. Filaggrin (FLG) is synthesized as a large precursor, profilaggrin, and is expressed in the upper layers of the epidermis. FLG plays a critical role in the epidermal barrier, and FLG mutations cause abnormal epidermal function. FLG mutations are strongly associated with early-onset, and persistent severe AD. In addition, FLG deficiency in the epidermis is related to allergic sensitization and asthma. The basic skin care including repair and protection of the skin barrier with proper hydration and topical anti-inflammatory therapy is important to control the severity of skin disease in patients with AD.

The signal transducer and activator of transcription 6 gene (STAT6) increases the propensity of patients with atopic dermatitis toward disseminated viral skin infections

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with increased susceptibility to recurrent skin infections.

OBJECTIVE

We sought to determine why a subset of patients with AD have an increased risk of disseminated viral skin infections.

METHODS

Human subjects with AD with a history of eczema herpeticum (EH) and various control groups were enrolled. Vaccinia virus (VV) expression was measured by means of PCR and immunofluorescent staining in skin biopsy specimens from each study group after incubation with VV. Transgenic mice with a constitutively active signal transducer and activator of transcription 6 gene (STAT6) were characterized for response to VV skin inoculation. Genotyping for 10 STAT6 single nucleotide polymorphisms (SNPs) was performed in a white patient sample (n = 444).

RESULTS

VV gene and protein expression were significantly increased in the skin of patients with EH compared with other subject groups after incubation with VV in vitro. Antibody neutralization of IL-4 and IL-13 resulted in lower VV replication in patients with a history of EH. Mice that expressed a constitutively active STAT6 gene compared with wild-type mice had increased mortality and satellite lesion formation after VV skin inoculation. Significant associations were observed between STAT6 SNPs and EH (rs3024975, rs841718, rs167769, and rs703817) and IFN-γ production. The strongest association was observed for a 2-SNP haplotype (patients with AD with a history of EH vs patients with AD without a history of EH, 24.9% vs 9.2%; P = 5.17 × 10(-6)).

CONCLUSION

The STAT6 gene increases viral replication in the skin of patients with AD with a history of EH. Further genetic association studies and functional investigations are warranted.

Specificity protein 1 is pivotal in the skin's antiviral response

BACKGROUND

Previous studies have found specificity protein (Sp) 1 transcription factor in the viral replication machinery and postulated that Sp1 was required for viral replication in host cells.

OBJECTIVES

We investigated the role of Sp1 in the skin's antiviral responses from the perspective of host defense and its biological relevance in patients with atopic dermatitis and a history of eczema herpeticum (ADEH(+)).

METHODS

Small interfering RNA duplexes were used to knock down Sp1 in keratinocytes. The expression of vaccinia virus (VV), herpes simplex virus 1, and other genes were evaluated by real-time PCR, or combined with Western blot and immunohistofluorescence staining. A total of 106 human subjects participated in this study.

RESULTS

Both VV and herpes simplex virus 1 replication were enhanced in Sp1 knocked-down keratinocytes. Sp1 gene expression was significantly decreased in ADEH(+) subjects compared with patients with atopic dermatitis without a history of eczema herpeticum and nonatopic subjects (P < .0001) and inversely correlated with VV DNA copy number in human skin explants incubated with VV in vitro (partial correlation r = -0.256; P = .009). Gene profiling revealed that the antiviral genes, double-stranded RNA-dependent protein kinase (PKR) and 2'5'-oligoadenylate synthetase 2 (OAS2), were significantly downregulated in Sp1-silenced keratinocytes. Gene expression of PKR and OAS2 was also significantly decreased in skin biopsies from ADEH(+) subjects compared with patients with atopic dermatitis without a history of eczema herpeticum and nonatopic subjects. IFN-γ augmented the antiviral capacity of Sp1-silenced keratinocytes.

CONCLUSION

Specificity protein 1 knockdown enhances viral replication in keratinocytes by downregulating gene expression of PKR and OAS2. Sp1 deficiency in ADEH(+) patients may contribute to their increased propensity to disseminated skin viral infections. IFN-γ augmentation may be a potential treatment for ADEH(+) patients.

Cytokine modulation of atopic dermatitis filaggrin skin expression

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD.

OBJECTIVE

We investigated whether reduced filaggrin expression was found in patients with AD who were not carriers of known filaggrin mutations and whether filaggrin expression was modulated by the atopic inflammatory response.

METHODS

Filaggrin expression was measured in skin biopsies and cultured keratinocytes using real-time RT-PCR and immunohistochemistry. Filaggrin loss-of-function mutations were screened in a total of 69 subjects.

RESULTS

Compared with normal skin, filaggrin expression was significantly reduced (P < .05) in acute AD skin, with further reduction seen in acute lesions from 3 European American subjects with AD who were heterozygous for the 2282del4 mutation. This was confirmed by using immunohistochemistry. AD skin is characterized by the overexpression of IL-4 and IL-13. Keratinocytes differentiated in the presence of IL-4 and IL-13 exhibited significantly reduced filaggrin gene expression (0.04 +/- 0.01 ng filaggrin/ng glyceraldehyde 3-phosphate dehydrogenase; P < .05) compared with media alone (0.16 +/- 0.03).

CONCLUSION

Patients with AD have an acquired defect in filaggrin expression that can be modulated by the atopic inflammatory response.

CLINICAL IMPLICATIONS

The atopic immune response contributes to the skin barrier defect in AD; therefore, neutralization of IL-4 and IL-13 could improve skin barrier integrity.

Th2 cytokines act on S100/A11 to downregulate keratinocyte differentiation

Atopic dermatitis (AD) is an inflammatory skin disease associated with frequent skin infection and impaired skin barrier function. Recent studies indicate that increased Th2 cytokine expression contributes to reduction in antimicrobial peptides and reduced filaggrin (FLG) expression, however, the mechanisms leading to this effect is unknown. Using proteomics, we found the S100 calcium-binding protein A11 (S100/A11) to be significantly downregulated in the presence of IL-4 and IL-13. Culturing keratinocytes with increased calcium concentrations significantly induced S100/A11 expression. This corresponded with an increase in human beta-defensin (HBD)-3 and FLG expression. Interference of S100/A11 expression, by siRNA, inhibited induction of HBD-3 and FLG. Furthermore p21, a cyclin-dependent kinase inhibitor downstream of S100/A11, was required for calcium-mediated induction of HBD-3 and FLG. Importantly, transduction of p21-recombinant protein into keratinocytes prevented IL-4/IL-13-mediated inhibition of FLG and HBD-3 expression. S100/A11 and p21 gene expression was also found to be significantly lower in acute and chronic AD skin. This study demonstrates an important role for S100/A11 and p21 in regulating skin barrier integrity and the innate immune response.

Loricrin and involucrin expression is down-regulated by Th2 cytokines through STAT-6

Atopic dermatitis (AD) is characterized by a defective skin barrier which allows increased allergen and pathogen penetration. Loricrin (LOR) and involucrin (IVL) are proteins important for skin barrier formation and integrity. In this study, we demonstrate that the gene and protein expression of LOR and IVL is significantly decreased in involved (LOR: p<0.001; IVL: p<0.001) and uninvolved (LOR: p<0.001; IVL: p<0.001) skin of AD subjects, as compared to skin from healthy subjects. Using primary keratinocytes, we further demonstrate the down-regulatory effect of IL-4 and IL-13--which are over-expressed in the skin of AD patients--on LOR and IVL expression in keratinocytes. Additionally, skin biopsies from signal transducer and activator of transcription (STAT)-6 transgenic mice were deficient in the expression and production of LOR and IVL. This study suggests that Th2 cytokines inhibit expression of LOR and IVL through a STAT-6 dependent mechanism.

Cytokine modulation of atopic dermatitis filaggrin skin expression

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD.

OBJECTIVE

We investigated whether reduced filaggrin expression was found in patients with AD who were not carriers of known filaggrin mutations and whether filaggrin expression was modulated by the atopic inflammatory response.

METHODS

Filaggrin expression was measured in skin biopsies and cultured keratinocytes using real-time RT-PCR and immunohistochemistry. Filaggrin loss-of-function mutations were screened in a total of 69 subjects.

RESULTS

Compared with normal skin, filaggrin expression was significantly reduced (P < .05) in acute AD skin, with further reduction seen in acute lesions from 3 European American subjects with AD who were heterozygous for the 2282del4 mutation. This was confirmed by using immunohistochemistry. AD skin is characterized by the overexpression of IL-4 and IL-13. Keratinocytes differentiated in the presence of IL-4 and IL-13 exhibited significantly reduced filaggrin gene expression (0.04 +/- 0.01 ng filaggrin/ng glyceraldehyde 3-phosphate dehydrogenase; P < .05) compared with media alone (0.16 +/- 0.03).

CONCLUSION

Patients with AD have an acquired defect in filaggrin expression that can be modulated by the atopic inflammatory response.

CLINICAL IMPLICATIONS

The atopic immune response contributes to the skin barrier defect in AD; therefore, neutralization of IL-4 and IL-13 could improve skin barrier integrity.

Macrophage inflammatory protein 3alpha deficiency in atopic dermatitis skin and role in innate immune response to vaccinia virus

BACKGROUND

Patients with atopic dermatitis (AD) are prone to disseminated viral skin infections and therefore are not vaccinated against smallpox because of potential complications. Macrophage inflammatory protein 3alpha (MIP-3alpha) is a C-C chemokine expressed by keratinocytes that exhibits antimicrobial activity against bacteria and fungi; however, its role in antiviral innate immunity is unknown.

OBJECTIVE

Evaluate the level of MIP-3alpha in AD skin and its role in the innate immune response to vaccinia virus (VV).

METHODS

Macrophage inflammatory protein 3alpha levels were evaluated using real-time RT-PCR, immunodot-blot, and immunohistochemistry. The antiviral activity of MIP-3alpha was determined using a standard viral plaque assay.

RESULTS

Macrophage inflammatory protein 3alpha gene expression was significantly (P < .01) decreased in AD skin (0.21 +/- 0.05 ng MIP-3alpha/ng glyceraldehyde-3-phosphate dehydrogenase) compared with psoriasis skin (0.67 +/- 0.13). This was confirmed at the protein level using immunohistochemistry. We further demonstrate that T(H)2 cytokines downregulate MIP-3alpha expression. The importance of MIP-3alpha in the innate immune response against VV was established by first demonstrating that MIP-3alpha exhibits activity against VV. Second, VV replication was significantly increased (P < .01) in keratinocytes treated with an antibody to neutralize MIP-3alpha.

CONCLUSION

The current study demonstrates that MIP-3alpha exhibits antiviral activity against VV and demonstrates the importance of MIP-3alpha in the innate immune response against VV. In addition, AD skin is deficient in MIP-3alpha, in part because of the overexpression of T(H)2 cytokines in AD skin.

CLINICAL IMPLICATIONS

MIP-3alpha deficiency in AD skin contributes to patients' increased propensity toward eczema vaccinatum. Increasing MIP-3alpha or neutralizing T(H)2 cytokines could prevent adverse reactions in patients with AD after smallpox vaccination.

Human metapneumovirus infection in hospitalized children with acute respiratory disease in Korea

Human metapneumovirus (hMPV) is a recently isolated virus, mostly associated with acute lower respiratory infection in children, of which symptoms are similar to those of respiratory syncytial virus (RSV) infection. The aim of our study was to determine the frequency of hMPV in hospitalized children with acute respiratory tract disease in Korea. Nasal aspirates from hospitalized children with respiratory infections under 15 yr old between December 2003 and February 2005 were included in the study. Each sample was analyzed for RSV, adenovirus, influenza virus A and B, and parainfluenza virus by indirect fluorescent assay (IFA). F-gene sequences were used for PCR for the detection and sequencing of hMPV. In total 381 samples, negative samples in which any viral pathogen could not be identified by IFA were 231 cases. hMPV was detected using reverse transcriptase-PCR (RT-PCR) in 28 of 231 (12.1%) children who were not infected with another respiratory viruses. The hMPV-infected children were diagnosed as having pneumonia, bronchiolitis, bronchial asthma exacerbation, croup, and upper respiratory tract infection. Most of the RT-PCR positive samples for hMPV were collected in winter season. These results suggest that hMPV may be a responsible pathogen causing acute respiratory tract infection in Korean children.

Activation of caspase-8 in 3-deazaadenosine-induced apoptosis of U-937 cells occurs downstream of caspase-3 and caspase-9 without Fas receptor-ligand interaction

3-Deazaadenosine (DZA), a cellular methylation blocker was reported to induce the caspase-3-like activities-dependent apoptosis in U-937 cells. In this study, we analyzed the activation pathway of the caspase cascade involved in the DZA-induced apoptosis using specific inhibitors of caspases. In the U-937 cells treated with DZA, cytochrome c release from mitochondria and subsequent activation of caspase-9, -8 and -3 were observed before the induction of apoptosis. zDEVD-Fmk, a specific inhibitor of caspase-3, and zLEHD-Fmk, a specific inhibitor of caspase-9, prevented the activation of caspase-8 but neither caspase-3 nor caspase-9, indicating that caspase-8 is downstream of both caspase-3 and caspase-9, which are activated by independent pathways. zVAD-Fmk, a universal inhibitor of caspases, kept the caspase-3 from being activated but not caspase-9. Moreover, ZB4, an antagonistic Fas-antibody, exerted no effect on the activation of caspase-8 and induction of apoptosis by DZA. In addition, zVAD-Fmk and mitochondrial permeability transition pore (MPTP) inhibitors such as cyclosporin A (CsA) and bongkrekic acid (BA) did not block the release of cytochrome c from mitochondria. Taken together, these results suggest that in the DZA-induced apoptosis, caspase-8 may serve as an executioner caspase and be activated downstream of both caspase-3 and caspase-9, independently of Fas receptor-ligand interaction. And caspase-3 seems to be activated by other caspses including IETDase-like enzyme and caspse-9 seems to be activated by cytochrome c released from mitochondria without the involvement of caspases and CsA- and BA- inhibitory MPTP.

Induction of apoptosis in human leukemia cells by 3-deazaadenosine is mediated by caspase-3-like activity

3-Deazaadenosine (DZA), one of the potent inhibitors of S-adenosylhomocysteine hydrolase, is known to possess several biological properties including an induction of apoptosis. To evaluate a possibility that DZA may be utilized for the treatment of human leukemia, we studied molecular events of cell death induced by DZA in human leukemia HL-60 and U-937 cells. DZA induced a specific cleavage of poly ADP-ribose polymerase (PARP) and an activation of the cysteine protease caspase-3/CPP32 which is known to cleave PARP. DZA-mediated nuclear DNA-fragmentation was completely blocked in the presence of a universal inhibitor of caspases (z-VAD-fmk) or the specific inhibitor of caspase-3 (z-DEVD-fmk) unlike of cycloheximide (CHX). DNA fragmentation was preceded by the lowering of c-myc mRNA in the DZA treated cells. In addition, DZA-induced apoptosis was blocked by pretreatment with adenosine transporter inhibitors such as nitrobenzylthioinosine (NBTI) and dipyridamole (DPD). Taken together, these results demonstrate that DZA-induced apoptosis initiated through an active transport of DZA into human leukemia cells, is dependent on the caspase-3-like activity without de novo synthesis of proteins and possibly involves c-myc down-regulation.

[A study of the effects of health contracts on the performance level for activities of daily living in the hemiplegic patients]

The purpose of this study was to test the effects of health contract on the performance level for activity of daily living (ADL) in the hemiplegic patients. A quasi-experimental research for health contract, which was approved as an effective method of nursing intervention, was attempted to increase the performance of the hemiplegic patients' ADL. As a purpose sample, 69 hemiplegic patients hospitalized at Oriental medicine hospital of K university were taken and divided into the experimental group and the control group by means of random assignment. After Contracting with the experimental group, they were reinforced everyday for 20 minutes. The experimental group and the control group were observed and interviewed for five times at the interval of 3-4 days by the trained nurses for this research. The data Collected through above mentioned methods were compute analyzed by t-test and ANOVA according to the purpose of this study. The data collected through above mentioned methods were computer analyzed by t-test and ANOVA according to the purpose of this study. Strate increased the performance level for ADL than the Control group" was supported (t = 2.96, df = 52.76, p = .004). Sub Hypothesis 1,2,4,5: "The hypothesis that the experimental group with health contract will demonstrate increased the performance level for eating (t = 2.29, df = 42.70, p = .027), personal hygiene and grooming (t = 4.04, df = 43.10, p = .000), dressing (t = 3.32, df = 67, p = .001) and undressing (t = 3.47, df = 48.44, p = .001) than the control group" was supported. Sub Hypothesis 3.6: "The hypothesis that the experimental group with health contract will demonstrate increased the performance level for toiletting (t = .19, df = 67, p = .849) and mobilization (t = .30, df = 67, p = .765) than the control group" was not supported. The conclusion can be that the positive relationship between the nurse and the patient results in the desired performance level for ADL in the hemiplegic patients.