Calcitriol, an Active Form of Vitamin D3, Mitigates Skin Barrier Dysfunction in Atopic Dermatitis NC/Nga Mice.

Atopic dermatitis and psoriasis are prevalent chronic inflammatory skin diseases that are characterized by dysfunctional skin barriers and substantially impact patients' quality of life. Vitamin D3 regulates immune responses and keratinocyte differentiation and improves psoriasis symptoms; however, its effects on atopic dermatitis remain unclear. Here, we investigated the effects of calcitriol, an active form of vitamin D3, on an NC/Nga mouse model of atopic dermatitis. We observed that the topical application of calcitriol decreased the dermatitis scores and epidermal thickness of NC/Nga mice with atopic dermatitis compared to untreated mice. In addition, both stratum corneum barrier function as assessed by the measurement of transepidermal water loss and tight junction barrier function as evaluated by biotin tracer permeability assay were improved following calcitriol treatment. Moreover, calcitriol treatment reversed the decrease in the expression of skin barrier-related proteins and decreased the expression of inflammatory cytokines such as interleukin (IL)-13 and IL-33 in mice with atopic dermatitis. These findings suggest that the topical application of calcitriol might improve the symptoms of atopic dermatitis by repairing the dysfunctional epidermal and tight junction barriers. Our results suggest that calcitriol might be a viable therapeutic agent for the treatment of atopic dermatitis in addition to psoriasis.

The Antimicrobial Peptide AMP-IBP5 Suppresses Dermatitis-like Lesions in a Mouse Model of Atopic Dermatitis through the Low-Density Lipoprotein Receptor-Related Protein-1 Receptor.

The antimicrobial peptide derived from insulin-like growth factor-binding protein 5 (AMP-IBP5) exhibits antimicrobial activities and immunomodulatory functions in keratinocytes and fibroblasts. However, its role in regulating skin barrier function remains unclear. Here, we investigated the effects of AMP-IBP5 on the skin barrier and its role in the pathogenesis of atopic dermatitis (AD). 2,4-Dinitrochlorobenzene was used to induce AD-like skin inflammation. Transepithelial electrical resistance and permeability assays were used to investigate tight junction (TJ) barrier function in normal human epidermal keratinocytes and mice. AMP-IBP5 increased the expression of TJ-related proteins and their distribution along the intercellular borders. AMP-IBP5 also improved TJ barrier function through activation of the atypical protein kinase C and Rac1 pathways. In AD mice, AMP-IBP5 ameliorated dermatitis-like symptoms restored the expression of TJ-related proteins, suppressed the expression of inflammatory and pruritic cytokines, and improved skin barrier function. Interestingly, the ability of AMP-IBP5 to alleviate inflammation and improve skin barrier function in AD mice was abolished in mice treated with an antagonist of the low-density lipoprotein receptor-related protein-1 (LRP1) receptor. Collectively, these findings indicate that AMP-IBP5 may ameliorate AD-like inflammation and enhance skin barrier function through LRP1, suggesting a possible role for AMP-IBP5 in the treatment of AD.

Cathelicidin LL-37 Activates Human Keratinocyte Autophagy through the P2X7, Mechanistic Target of Rapamycin, and MAPK Pathways.

Human cathelicidin LL-37 is a multifunctional antimicrobial peptide that exhibits antimicrobial and immunomodulatory activities. LL-37 regulates skin barrier function and was recently reported to activate autophagy in macrophages. Because autophagy deficiency is associated with skin diseases characterized by a dysfunctional epidermal barrier, we hypothesized that LL-37 might regulate the skin barrier through autophagy modulation. We showed that LL-37 activated autophagy in human keratinocytes and three-dimensional skin equivalent models as indicated by increases in LC3 puncta formation, decreases in p62, and autophagosome and autolysosome formation. LL-37‒induced autophagy was suppressed by P2X7 receptor, adenosine monophosphate‒activated protein kinase, and unc-51-like kinase 1 inhibitors, suggesting that the P2X7, adenosine monophosphate‒activated protein kinase, and unc-51-like kinase 1 pathways are involved. Moreover, LL-37 enhanced the phosphorylation of adenosine monophosphate‒activated protein kinase and unc-51-like kinase 1. In addition, LL-37‒mediated autophagy involves the mechanistic target of rapamycin and MAPK pathways. Interestingly, the LL-37‒induced distribution of tight junction proteins and improvement in the tight junction barrier were inhibited in autophagy-deficient keratinocytes and keratinocytes and skin models treated with autophagy inhibitors, indicating that the LL-37‒mediated tight junction barrier is associated with autophagy activation. Collectively, these findings suggest that LL-37 is a potential therapeutic target for skin diseases characterized by dysfunctional autophagy and skin barriers.

The Antimicrobial Peptides Human ß-Defensins Induce the Secretion of Angiogenin in Human Dermal Fibroblasts.

The skin produces a plethora of antimicrobial peptides that not only show antimicrobial activities against pathogens but also exhibit various immunomodulatory functions. Human ß-defensins (hBDs) are the most well-characterized skin-derived antimicrobial peptides and contribute to diverse biological processes, including cytokine production and the migration, proliferation, and differentiation of host cells. Additionally, hBD-3 was recently reported to promote wound healing and angiogenesis, by inducing the expression of various angiogenic factors and the migration and proliferation of fibroblasts. Angiogenin is one of the most potent angiogenic factors; however, the effects of hBDs on angiogenin production in fibroblasts remain unclear. Here, we investigated the effects of hBDs on the secretion of angiogenin by human dermal fibroblasts. Both in vitro and ex vivo studies demonstrated that hBD-1, hBD-2, hBD-3, and hBD-4 dose-dependently increased angiogenin production by fibroblasts. hBD-mediated angiogenin secretion involved the epidermal growth factor receptor (EGFR), Src family kinase, c-Jun N-terminal kinase (JNK), p38, and nuclear factor-kappa B (NF-κB) pathways, as evidenced by the inhibitory effects of specific inhibitors for these pathways. Indeed, we confirmed that hBDs induced the activation of the EGFR, Src, JNK, p38, and NF-κB pathways. This study identified a novel role of hBDs in angiogenesis, through the production of angiogenin, in addition to their antimicrobial activities and other immunomodulatory properties.

Human ß-defensin-3 attenuates atopic dermatitis-like inflammation through autophagy activation and the aryl hydrocarbon receptor signaling pathway.

Human ß-defensin-3 (hBD-3) exhibits antimicrobial and immunomodulatory activities; however, its contribution to autophagy regulation remains unclear, and the role of autophagy in the regulation of the epidermal barrier in atopic dermatitis (AD) is poorly understood. Here, keratinocyte autophagy was restrained in the skin lesions of patients with AD and murine models of AD. Interestingly, hBD-3 alleviated the IL-4- and IL-13-mediated impairment of the tight junction (TJ) barrier through keratinocyte autophagy activation, which involved aryl hydrocarbon receptor (AhR) signaling. While autophagy deficiency impaired the epidermal barrier and exacerbated inflammation, hBD-3 attenuated skin inflammation and enhanced the TJ barrier in AD. Importantly, hBD-3-mediated improvement of the TJ barrier was abolished in autophagy-deficient AD mice and in AhR-suppressed AD mice, suggesting a role for hBD-3-mediated autophagy in the regulation of the epidermal barrier and inflammation in AD. Thus, autophagy contributes to the pathogenesis of AD, and hBD-3 could be used for therapeutic purposes.

Antimicrobial peptide derived from insulin-like growth factor-binding protein 5 improves diabetic wound healing.

Impaired keratinocyte functions are major factors that are responsible for delayed diabetic wound healing. In addition to its antimicrobial activity, the antimicrobial peptide derived from insulin-like growth factor-binding protein 5 (AMP-IBP5) activates mast cells and promotes keratinocyte and fibroblast proliferation and migration. However, its effects on diabetic wound healing remain unclear. Human keratinocytes were cultured in normal or high glucose milieus. The production of angiogenic growth factor and cell proliferation and migration were evaluated. Wounds in normal and streptozotocin-induced diabetic mice were monitored and histologically examined. We found that AMP-IBP5 rescued the high glucose-induced attenuation of proliferation and migration as well as the production of angiogenin and vascular endothelial growth factors in keratinocytes. The AMP-IBP5-induced activity was mediated by the epidermal growth factor receptor, signal transducer and activator of transcription 1 and 3, and mitogen-activated protein kinase pathways, as indicated by the inhibitory effects of pathway-specific inhibitors. In vivo, AMP-IBP5 markedly accelerated wound healing, increased the expression of angiogenic factors and promoted vessel formation in both normal and diabetic mice. Overall, the finding that AMP-IBP5 accelerated diabetic wound healing by protecting against glucotoxicity and promoting angiogenesis suggests that AMP-IBP5 might be a potential therapeutic target for treating chronic diabetic wounds.

The Antimicrobial Peptide Human ß-Defensin-3 Accelerates Wound Healing by Promoting Angiogenesis, Cell Migration, and Proliferation Through the FGFR/JAK2/STAT3 Signaling Pathway.

In addition to its antimicrobial activity, the skin-derived antimicrobial peptide human ß-defensin-3 (hBD-3) promotes keratinocyte proliferation and migration to initiate the wound healing process; however, its effects on fibroblasts, which are the major cell type responsible for wound healing, remain unclear. We investigated the role of hBD-3 in cell migration, proliferation and production of angiogenic growth factors in human fibroblasts and evaluated the in vivo effect of hBD-3 on promoting wound healing and angiogenesis. Following hBD-3 treatment, the mouse wounds healed faster and showed accumulation of neutrophils and macrophages in the early phase of wound healing and reduction of these phagocytes 4 days later. hBD-3-treated wounds also displayed an increased number of fibroblasts and newly formed vessels compared to those of the control mice. Furthermore, the expression of various angiogenic growth factors was increased in the hBD-3-treated wounds. Additionally, in vitro studies demonstrated that hBD-3 enhanced the secretion of angiogenic growth factors such as fibroblast growth factor, platelet-derived growth factor and vascular endothelial growth factor and induced the migration and proliferation of human fibroblasts. The hBD-3-mediated activation of fibroblasts involves the fibroblast growth factor receptor 1 (FGFR1)/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathways, as evidenced by the inhibitory effects of pathway-specific inhibitors. We indeed confirmed that hBD-3 enhanced the phosphorylation of FGFR1, JAK2 and STAT3. Collectively, the current study provides novel evidence that hBD-3 might be a potential candidate for the treatment of wounds through its ability to promote wound healing, angiogenesis and fibroblast activation.

Pertussis Infants Needing Mechanical Ventilation and Extracorporeal Membrane Oxygenation: Single-Center Retrospective Series in Vietnam.

OBJECTIVES: Pertussis is an infectious disease that causes epidemics and outbreaks and is associated with a high mortality rate, especially in infants, in both developed and developing countries. We aimed to characterize infants with pertussis with respiratory failure and shock and investigated the factors related to mortality. DESIGN: A retrospective, observational study conducted between January 2015 and October 2020. SETTING: This study was conducted at the Vietnam National Children's Hospital, which is a government hospital that serves as a tertiary care center in Hanoi, Vietnam. PATIENTS: Children who fulfilled the following inclusion criteria were included: 1) admitted to the PICU, 2) less than 16 years old, 3) pertussis confirmed by real-time polymerase chain reaction, and 4) treated with mechanical ventilation due to respiratory failure and shock. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Seventy-three mechanically ventilated children (40 boys; median age, 56 d), whereas 19 patients received extracorporeal membrane oxygenation support. Twenty-six patients (36%) died including 12 who received extracorporeal membrane oxygenation. Those who received extracorporeal membrane oxygenation support had higher leukocyte counts upon admission and were more frequently diagnosed with pulmonary hypertension and stage 3 acute kidney injury. Compared with survivors, nonsurvivors showed increased heart rates, leukocyte and neutrophil counts, and lower systolic and diastolic blood pressure at admission. Increased Vasoactive-Inotropic Score, stage 3 acute kidney injury, fluid overload, the use of renal replacement therapy, and extracorporeal membrane oxygenation use were prevalent among nonsurvivors. CONCLUSIONS: In this study, around one third of mechanically ventilated patients with pertussis died. Those who received extracorporeal membrane oxygenation had higher leukocyte counts, a higher prevalence of pulmonary hypertension, and advanced stages of acute kidney injury. Higher Vasoactive-Inotropic Score and advanced stages of acute kidney injury were associated with a greater risk of mortality.

Intractable Itch in Atopic Dermatitis: Causes and Treatments.

Itch or pruritus is the hallmark of atopic dermatitis and is defined as an unpleasant sensation that evokes the desire to scratch. It is also believed that itch is a signal of danger from various environmental factors or physiological abnormalities. Because histamine is a well-known substance inducing itch, H1-antihistamines are the most frequently used drugs to treat pruritus. However, H1-antihistamines are not fully effective against intractable itch in patients with atopic dermatitis. Given that intractable itch is a clinical problem that markedly decreases quality of life, its treatment in atopic dermatitis is of high importance. Histamine-independent itch may be elicited by various pruritogens, including proteases, cytokines, neuropeptides, lipids, and opioids, and their cognate receptors, such as protease-activated receptors, cytokine receptors, Mas-related G protein-coupled receptors, opioid receptors, and transient receptor potential channels. In addition, cutaneous hyperinnervation is partly involved in itch sensitization in the periphery. It is believed that dry skin is a key feature of intractable itch in atopic dermatitis. Treatment of the underlying conditions that cause itch is necessary to improve the quality of life of patients with atopic dermatitis. This review describes current insights into the pathophysiology of itch and its treatment in atopic dermatitis.

Exogenous factors in the pathogenesis of atopic dermatitis: Irritants and cutaneous infections.

Atopic dermatitis (AD) is a chronic relapsing inflammatory cutaneous disease that is often associated with other atopic symptoms, such as food allergy, allergic rhinitis and asthma, leading to significant morbidity and healthcare costs. The pathogenesis of AD is complicated and multifactorial. Although the aetiology of AD remains incompletely understood, recent studies have provided further insight into AD pathophysiology, demonstrating that the interaction among genetic predisposition, immune dysfunction and environmental provocation factors contributes to its development. However, the increasing prevalence of AD suggests that environmental factors such as irritation and cutaneous infection play a crucial role in triggering and/or aggravating the disease. Of note, AD skin is susceptible to bacterial, fungal and viral infections, and microorganisms may colonize the skin and aggravate AD symptoms. Overall, understanding the mechanisms by which these risk factors affect the cutaneous immunity of patients with AD is of great importance for developing a precision medicine approach for treatment. This review summarizes recent developments in exogenous factors involved in the pathogenesis of AD, with special emphasis on irritants and microbial infections.

Recycling of aquaculture wastewater and sediment for sustainable corn and water spinach production.

This study develops a method to reuse aquaculture wastewater and sediment from a catfish pond in order to increase agricultural productivity and protect the environment. Material flow analysis (MFA) is a central concept of this study that involves collecting catfish pond wastewater (CPW) and reusing it to irrigate five water spinach (Ipomoea aquatic) ponds before discharging it into a river. Typically, catfish pond sediment (CPS) was collected and composted to produce organic fertilizer for cornfields. The results revealed that pollutant removal efficiency of wastewater from CPW (by using water spinach) were total organic carbon (TOC) = 38.78%, nitrogen (N) = 27.07%, phosphorous (P) = 58.42%, and potassium (K) = 28.64%. By adding 20 tons of CPS compost per hectare of the cornfield, the corn yield boosted 15% compared to the control field. In addition, the water spinach grew and developed well in the medium of wastewater from the fish pond. Altogether, the results illustrate that catfish pond wastewater and sediment can act as organic fertilizers for crops meanwhile reduce environmental pollution from its reuse.

Role of Antimicrobial Peptides in Skin Barrier Repair in Individuals with Atopic Dermatitis.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that exhibits a complex interplay of skin barrier disruption and immune dysregulation. Patients with AD are susceptible to cutaneous infections that may progress to complications, including staphylococcal septicemia. Although most studies have focused on filaggrin mutations, the physical barrier and antimicrobial barrier also play critical roles in the pathogenesis of AD. Within the physical barrier, the stratum corneum and tight junctions play the most important roles. The tight junction barrier is involved in the pathogenesis of AD, as structural and functional defects in tight junctions not only disrupt the physical barrier but also contribute to immunological impairments. Furthermore, antimicrobial peptides, such as LL-37, human b-defensins, and S100A7, improve tight junction barrier function. Recent studies elucidating the pathogenesis of AD have led to the development of barrier repair therapy for skin barrier defects in patients with this disease. This review analyzes the association between skin barrier disruption in patients with AD and antimicrobial peptides to determine the effect of these peptides on skin barrier repair and to consider employing antimicrobial peptides in barrier repair strategies as an additional approach for AD management.

The Supporting Adolescent Adherence in Vietnam (SAAV) study: study protocol for a randomized controlled trial assessing an mHealth approach to improving adherence for adolescents living with HIV in Vietnam.

BACKGROUND: The overall goal of the Supporting Adolescent Adherence in Vietnam (SAAV) study is to improve understanding of an adherence feedback mHealth intervention designed to help adolescents living with HIV (ALHIV) maintain high adherence to antiretroviral therapy (ART), critical to effective treatment. Specifically, we aim to: (1) conduct formative research with Vietnamese ALHIV and their caregivers to better understand adherence challenges and refine the personalized mHealth intervention package; and (2) assess the feasibility, acceptability, and efficacy of the intervention to improve ART adherence by implementing a randomized controlled trial (RCT). METHODS: The study will utilize mixed methods. The formative phase will include 40 in-depth interviews (IDIs) with 20 adolescent (12-17 years)/caregiver dyads and eight focus group discussions with adolescents, caregivers, and clinicians at the National Hospital for Pediatrics (NHP) in Hanoi, Vietnam. We will also conduct 20 IDIs with older adolescents (18-21 years) who have transitioned to adult care at outpatient clinics in Hanoi. We will then implement a seven-month RCT at NHP. We will recruit 80 adolescents on ART, monitor their adherence for one month to establish baseline adherence using a wireless pill container (WPC), and then randomize participants to intervention versus control within optimal (≥ 95% on-time doses) versus suboptimal (< 95% on-time doses) baseline adherence strata. Intervention participants will receive a reminder of their choice (cellphone text message/call or bottle-based flash/alarm), triggered when they miss a dose, and engage in monthly counseling informed by their adherence data. Comparison participants will receive usual care and offer of counseling at routine monthly clinic visits. After six months, we will compare ART adherence, CD4 count, and HIV viral suppression between arms, in addition to acceptability and feasibility of the intervention. DISCUSSION: Findings will contribute valuable information on perceived barriers and facilitators affecting adolescents' ART adherence, mHealth approaches as adherence support tools for ALHIV, and factors affecting adolescents' ART adherence. This information will be useful to researchers, medical personnel, and policy-makers as they develop and implement adherence programs for ALHIV, with potential relevance to other chronic diseases during transition from adolescent to adult care. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03031197 . Registered on 21 January 2017.

Three novel mutations in the ATP7B gene of unrelated Vietnamese patients with Wilson disease.

BACKGROUND: Wilson disease (OMIM # 277900) is a autosomal recessive disorder characterized by accumulation of copper in liver and brain. The accumulation of copper resulting in oxidative stress and eventually cell death. The disease has an onset in a childhood and result in a significant neurological impairment or require lifelong treatment. Another serious consequence of the disease is the development of liver damage and acute liver failure leading to liver transplant. The disorder is caused by mutations in the ATP7B gene, encoding a P-type copper transporting ATPase. CASE PRESENTATION: We performed genetic analysis of three unrelated patients from three different Vietnamese families. These patients had clinical features such as numbness of hands and feet, vomiting, insomnia, palsy, liver failure and Kayser-Fleischer (K-F) rings and were diagnosed with Wilson disease in the Human Genetics Department, Vietnam National Children's Hospital. The entire coding region and adjacent splice sites of ATP7B gene were amplified and sequenced by Sanger method. Sequencing data were analyzed and compared with the ATP7B gene sequence published in Ensembl (ENSG00000123191) by using BioEdit software to detect mutations. CONCLUSIONS: In this study, five mutations in the ATP7B gene were found. Among of these, three mutations were novel: c.750_751insG (p.His251Alafs*19) in exon 2, c.2604delC (p.Pro868Profs*5) in exon 11, and c.3077 T > A (p.Phe1026Tyr) in exon 14. Our results of the mutations associated with Wilson disease might facilitate the development of effective treatment plans.

Adenovirus Type 7 Pneumonia in Children Who Died from Measles-Associated Pneumonia, Hanoi, Vietnam, 2014.

During a 2014 measles outbreak in Vietnam, postmortem pathologic examination of hospitalized children who died showed that adenovirus type 7 pneumonia was a contributory cause of death in children with measles-associated immune suppression. Adenovirus type 7 pneumonia should be recognized as a major cause of secondary infection after measles.

English-based Pediatric Emergency Medicine Software Improves Physician Test Performance on Common Pediatric Emergencies: A Multicenter Study in Vietnam.

INTRODUCTION: Global health agencies and the Vietnam Ministry of Health have identified pediatric emergency care and health information technology as high priority goals. Clinical decision support (CDS) software provides physicians with access to current literature to answer clinical queries, but there is limited impact data in developing countries. We hypothesized that Vietnamese physicians will demonstrate improved test performance on common pediatric emergencies using CDS technologies despite being in English. METHODS: This multicenter, prospective, pretest-posttest study was conducted in 11 Vietnamese hospitals enrolled a convenience sample of physicians who attended an 80-minute software training on a pediatric CDS software (PEMSoft). Two multiple-choice exams (A, B) were administered before and after the session. Participants, who received Test A as a pretest, received Test B as a posttest, and vice versa. Participants used the CDS software for the posttest. The primary outcome measure was the mean percentage difference in physician scores between the pretest and posttest, as calculated by a paired, two-tailed t-test. RESULTS: For the 203 participants, the mean pretest, posttest, and improvement scores were 37% (95% CI: 35-38%), 70% (95% CI: 68-72%), and 33% (95% CI: 30-36%), respectively, with p<0.0001. This represents an 89% improvement over baseline. Subgroup analysis of practice setting, clinical experience, and comfort level with written English and computers showed that all subgroups equivalently improved their test scores. CONCLUSION: After brief training, Vietnamese physicians can effectively use an English-based CDS software based on improved performance on a written clinical exam. Given this rapid improvement, CDS technologies may serve as a transformative tool in resource-poor environments.

Fatal respiratory infections associated with rhinovirus outbreak, Vietnam.

During an outbreak of severe acute respiratory infections in 2 orphanages, Vietnam, 7/12 hospitalized children died. All hospitalized children and 26/43 children from outbreak orphanages tested positive for rhinovirus versus 9/40 control children (p = 0.0005). Outbreak rhinoviruses formed a distinct genetic cluster. Human rhinovirus is an underappreciated cause of severe pneumonia in vulnerable groups.

Prevalence of antibodies against avian influenza A (H5N1) virus among Cullers and poultry workers in Ho Chi Minh City, 2005.

BACKGROUND: Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005. METHODOLOGY/PRINCIPAL FINDINGS: Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood. All sera tested negative using microneutralization tests. Three samples showed a 1ratio80 titer in the hemagglutination inhibition assay. CONCLUSIONS/SIGNIFICANCE: This study provides additional support for the low transmissibility of clade 1 H5N1 to humans, but limited transmission to highly exposed persons cannot be excluded given the presence of low antibody titers in some individuals.