Multiple Functions of the New Cytokine-Based Antimicrobial Peptide Thymic Stromal Lymphopoietin (TSLP)

Roles of NOC3L and DDX17 in acquired immunodeficiency complicated with viral myocarditis and osteoporosis

Acquired immunodeficiency syndrome is a systemic infectious disease caused by human immunodeficiency virus infection, which could attack the bones and heart. However, the relationship between Nuclear Complex Associated 3 Homolog (NOC3L) and DEAD box helicase 17 (DDX17) and acquired immunodeficiency complicated with viral myocarditis and osteoporosis is unclear. The acquired immune deficiency dataset GSE140713, GSE147162 and the osteoporosis dataset (GSE230665), and viral myocarditis dataset (GSE150392) configuration files were generated from gene expression omnibus. The differentially expressed genes (DEGs) were screened and performed weighted gene co-expression network analysis. Construction and analysis of protein-protein interaction network. Functional enrichment analysis, gene set enrichment analysis, immune infiltration analysis, gene expression heatmap, and comparative toxicogenomics database analysis were performed. TargetScan screens miRNAs of DEGs. Thousand three hundred thirty-five DEGs were identified. According to gene ontology, they are mainly concentrated in the regulation of RNA biosynthesis, cytoplasmic ribosome, and the DNA binding transcription factor activity. In Kyoto Encyclopedia of Genes and Genomes analysis, they are mainly concentrated in TGF-β signal pathway, Notch signaling pathway, cAMP signaling pathway, and Apelin signaling pathway. Gene set enrichment analysis shows that DEGs are mainly enriched in cytoplasmic ribosome, transcriptional regulator activity, DNA binding transcription factor activity, TGF-β signal pathway, and Notch signal pathway. In the enrichment project of Metascape, tyrosine kinase receptor signaling, growth regulation, and enzyme-linked receptor protein signaling pathways can be seen in the gene ontology enrichment project. Four core genes (NOC3L, WDR46, SDAD1, and DDX17) were obtained. Core genes (NOC3L, WDR46, SDAD1, and DDX17) were low expressed in both acquired immunodeficiency and osteoporosis samples. Comparative toxicogenomics database analysis showed that core genes (NOC3L, WDR46, SDAD1, and DDX17) were associated with inflammation necrosis. The expressions of NOC3L and DDX17 are low in acquired immunodeficiency combined with viral myocarditis and osteoporosis.

Short-form thymic stromal lymphopoietin (sfTSLP) restricts herpes simplex virus infection of human primary keratinocytes

Eczema herpeticum (EH) is a disseminated severe herpes simplex virus type 1 (HSV-1) infection that mainly occurs in a subset of patients suffering from atopic dermatitis (AD). EH is complex and multifaceted, involving immunological changes, environmental influences, and genetic aberrations. Certain genetic variants of the thymic stromal lymphopoietin (TSLP) may predispose to develop severe HSV-1-induced eczema. Therefore, we investigated the impact of TSLP on HSV-1 infection. TSLP encodes for two distinct forms: a long-form (lfTSLP), primarily associated with type 2 immunity, and a short-form (sfTSLP) with anti-inflammatory and antimicrobial properties. While sfTSLP reduced HSV-1 infectibility in human primary keratinocytes (HPK), lfTSLP did not. In HPK treated with sfTSLP, HSV-1 gene expression, and replication decreased, while virion binding to cells and targeting of incoming capsids to the nucleus were not diminished compared to untreated cells. sfTSLP caused only minor changes in the expression of innate immunity cytokines, and its inhibition of HSV-1 infection did not require de novo protein synthesis. Time window experiments indicated a different antiviral mechanism than LL-37. sfTSLP showed the strongest antiviral effect when administered to HPK before or after inoculation with HSV-1, and outperformed the inhibitory potential of LL-37 under these conditions. Our data show that sfTSLP has antiviral functions and promotes repression of the HSV-1 infection in HPK.

Colonic Tuft Cells: The Less-Recognized Therapeutic Targets in Inflammatory Bowel Disease and Colorectal Cancer

Tuft cells are more than guardian chemosensory elements of the digestive tract. They produce a variety of immunological effector molecules in response to stimulation; moreover, they are essential for defense against protozoa and nematodes. Beyond the description of their characteristics, this review aims to elucidate the potential pathogenic and therapeutic roles of colonic tuft cells in inflammatory bowel disease and colorectal cancer, focusing on their primarily immunomodulatory action. Regarding inflammatory bowel disease, tuft cells are implicated in both maintaining the integrity of the intestinal epithelial barrier and in tissue repair and regeneration processes. In addition to maintaining intestinal homeostasis, they display complex immune-regulatory functions. During the development of colorectal cancer, tuft cells can promote the epithelial-to-mesenchymal transition, alter the gastrointestinal microenvironment, and modulate both the anti-tumor immune response and the tumor microenvironment. A wide variety of their biological functions can be targeted for anti-inflammatory or anti-tumor therapies; however, the adverse side effects of immunomodulatory actions must be strictly considered.

Thymic Stromal Lymphopoietin (TSLP), Its Isoforms and the Interplay with the Epithelium in Allergy and Asthma

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that has emerged as a critical player in the development and progression of allergy and asthma. It is primarily produced by epithelial cells and functions as a potent immune system activator. TSLP acts through interaction with its receptor complex, composed of the TSLP receptor (TSLPR) and interleukin-7 receptor alpha chain (IL-7Rα), activating downstream complex signalling pathways. The TSLP major isoform, known as long-form TSLP (lfTSLP), is upregulated in the airway epithelium of patients with allergic diseases. More research is warranted to explore the precise mechanisms by which short-form TSLP (sfTSLP) regulates immune responses. Understanding the dynamic interplay between TSLP and the dysfunctional epithelium provides insights into the mechanisms underlying allergy and asthma pathogenesis. Targeting TSLP represents an important therapeutic strategy, as it may upstream disrupt the inflammatory cascade and alleviate symptoms associated with allergic inflammation.

Eosinophilic gastroenteritis: Pathogenesis, diagnosis, and treatment

ABSTRACT

Eosinophilic gastroenteritis (EGE) is a gastrointestinal disorder of unclear etiology that is characterized by eosinophilic infiltration of the stomach and small intestine, and consists of mucosal, muscular, and serosal subtypes. Eosinophilic infiltration of the gastrointestinal tract is a fundamental histopathological characteristic of EGE and is driven by several T-helper type 2 (Th2)-dependent cytokines and induced by food allergy. Due to the lack of a diagnostic gold standard, EGE has a high rate of delayed diagnosis or misdiagnosis. However, several new diagnostic strategies have been developed, such as novel genetic biomarkers and imaging tests. Although dietary therapy and corticosteroids remain the common choices for EGE treatment, recent decades have seen the emergence of novel treatment alternatives, such as biologics that target particular molecules involved in the pathogenic process. Preliminary investigations and clinical trials have demonstrated the efficacy of biologics and provided additional insights for the era of refractory or corticosteroid-dependent EGE biologics.

Pruritogenic Mediators and New Antipruritic Drugs in Atopic Dermatitis

Atopic dermatitis (AD) is a common highly pruritic chronic inflammatory skin disorder affecting 5-20% of children worldwide, while the prevalence in adults varies from 7 to 10%. Patients with AD experience intense pruritus that could lead to sleep disturbance and impaired quality of life. Here, we analyze the pathophysiology of itchiness in AD. We extensively review the histamine-dependent and histamine-independent pruritogens. Several receptors, substance P, secreted molecules, chemokines, and cytokines are involved as mediators in chronic itch. We also, summarize the new emerging antipruritic drugs in atopic dermatitis.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Therapeutic Potential of MRGPRX2 Inhibitors on Mast Cells

Mast cells (MCs) act as primary effectors in inflammatory and allergic reactions by releasing intracellularly-stored inflammatory mediators in diseases. The two major pathways for MC activation are known to be immunoglobulin E (IgE)-dependent and -independent. Although IgE-dependent signaling is the main pathway to MC activation, IgE-independent pathways have also been found to serve pivotal roles in the pathophysiology of various inflammatory conditions. Recent studies have shown that human and mouse MCs express several regulatory receptors such as toll-like receptors (TLRs), CD48, C300a, and GPCRs, including mas-related GPCR-X2 (MRGPRX2). MRGPRX2 has been reported as a novel GPCR that is expressed in MCs activated by basic secretagogues, neurokinin peptides, host defense antimicrobial peptides, and small molecule compounds (e.g., neuromuscular blocking agents) and leads to MC degranulation and eicosanoids release under in vitro experimental condition. Functional analyses of MRGPRX2 and Mrgprb2 (mouse ortholog) indicate that MRGPRX2 is involved in MC hypersensitivity reactions causing neuroinflammation such as postoperative pain, type 2 inflammation, non-histaminergic itch, and drug-induced anaphylactic-like reactions. In this review, we discuss the roles in innate immunity through functional studies on MRGPRX2-mediated IgE-independent MC activation and also the therapeutic potential of MRGPRX2 inhibitors on allergic and inflammatory diseases.

The Implications of Pruritogens in the Pathogenesis of Atopic Dermatitis

Atopic dermatitis (AD) is a prototypic inflammatory disease that presents with intense itching. The pathophysiology of AD is multifactorial, involving environmental factors, genetic susceptibility, skin barrier function, and immune responses. A recent understanding of pruritus transmission provides more information about the role of pruritogens in the pathogenesis of AD. There is evidence that pruritogens are not only responsible for eliciting pruritus, but also interact with immune cells and act as inflammatory mediators, which exacerbate the severity of AD. In this review, we discuss the interaction between pruritogens and inflammatory molecules and summarize the targeted therapies for AD.

Potential Targets to Mitigate Trauma- or Sepsis-Induced Immune Suppression

In sepsis and trauma, pathogens and injured tissue provoke a systemic inflammatory reaction which can lead to overwhelming inflammation. Concurrent with the innate hyperinflammatory response is adaptive immune suppression that can become chronic. A current key issue today is that patients who undergo intensive medical care after sepsis or trauma have a high mortality rate after being discharged. This high mortality is thought to be associated with persistent immunosuppression. Knowledge about the pathophysiology leading to this state remains fragmented. Immunosuppressive cytokines play an essential role in mediating and upholding immunosuppression in these patients. Specifically, the cytokines Interleukin-10 (IL-10), Transforming Growth Factor-β (TGF-β) and Thymic stromal lymphopoietin (TSLP) are reported to have potent immunosuppressive capacities. Here, we review their ability to suppress inflammation, their dynamics in sepsis and trauma and what drives the pathologic release of these cytokines. They do exert paradoxical effects under certain conditions, which makes it necessary to evaluate their functions in the context of dynamic changes post-sepsis and trauma. Several drugs modulating their functions are currently in clinical trials in the treatment of other pathologies. We provide an overview of the current literature on the effects of IL-10, TGF-β and TSLP in sepsis and trauma and suggest therapeutic approaches for their modulation.

ISG15 Acts as a Mediator of Innate Immune Response to Pseudomonas aeruginosa Infection in C57BL/6J Mouse Corneas

Purpose

IFN-stimulated gene (ISG) 15 is a type 1 IFN-induced protein and known to modify target proteins in a manner similar to ubiquitylation (protein conjugation by ISG15 is termed ISGylation). We sought to determine the role of ISG15 and its underlying mechanisms in corneal innate immune defense against Pseudomonas aeruginosa keratitis.

Methods

ISG15 expression in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR and Western blot analysis. Gene knockout mice were used to define the role of ISG15 signaling in controlling the severity of P. aeruginosa keratitis, which was assessed with photographing, clinical scoring, bacterial counting, myeloperoxidase assay, and quantitative PCR determination of cytokine expression. Integrin LFA-1 inhibitor was used to assess its involvement of ISG15 signaling in P. aeruginosa-infected corneas.

Results

Heat-killed P. aeruginosa induced ISG15 expression in cultured HCECs and accumulation in the conditioned media. Isg15 deficiency accelerated keratitis progress, suppressed IFNγ and CXCL10, and promoted IL-1β while exhibiting no effects on IFNα expression. Moreover, exogenous ISG15 protected the corneas of wild-type mice from P. aeruginosa infection while markedly reducing the severity of P. aeruginosa keratitis in type 1 IFN-receptor knockout mice. Exogenous ISG15 increased bacteriostatic activity of B6 mouse corneal homogenates, and inhibition of LFA-1 exacerbated the severity of and abolished protective effects of ISG15 on P. aeruginosa keratitis.

Conclusions

Type 1 INF-induced ISG15 regulates the innate immune response and greatly reduces the susceptibility of B6 mouse corneas to P. aeruginosa infection in an LFA-1-dependent manner.

Chinese medicine Yu-Ping-Feng-San attenuates allergic inflammation by regulating epithelial derived pro-allergic cytokines

This study aimed to investigate the mechanisms of Yu-Ping-Feng-San (YPFS) on attenuating allergic inflammation in the initial stage of atopic dermatitis (AD). AD mouse model was established with fluorescein isothiocyanate (FITC) sensitization and elicitation. Epithelial barrier structure was observed with transmission electron microscope. The populations of dendritic cells (DCs) and group 2 innate lymphoid cells (ILC2s) were detected by flow cytometry. Human immortalized keratinocyte (HaCaT) cells were stimulated with Poly(I:C)/TNF-α in vitro to assessthymic stromal lymphopoietin (TSLP), interleukin (IL)-33 and nuclear factor-κB (NF-κB) levels or expressions by immunofluorescence, enzyme linked immunosorbent assay (ELISA) and western blot. In the initial stage of AD, ear swelling and infiltration of inflammatory cells in ear tissues were markedly attenuated with YPFS treatments. The damaged structures of ear epithelium and the increased levels of Th2-cytokines induced by FITC were significantly rescued in YPFS-treated mice. The production of pro-allergic cytokines, TSLP and IL-33, as well as the cell populations of their target cells DCs and ILC2s were decreased in AD model, respectively. Likewise, the levels of TSLP and IL-33 in Poly(I:C)/TNF-α-stimulated HaCaT cells showed the same results. Lower levels of p-NF-κB were detected with YPFS treatment, and the expressions of TSLP and IL-33 could be further decreased with inhibiting of NF-κB. Therefore, YPFS attenuates allergic inflammation in the initial stage of AD probably through regulating NF-κB-TSLP/IL-33 pathway, which may provide a novel effective target for the prevention and treatment of allergic diseases.

Association between fine mapping thymic stromal lymphopoietin and atopic dermatitis onset and persistence

BACKGROUND

Atopic dermatitis (AD) is a common chronic relapsing skin disease. Genetic variants have been associated with skin barrier function and immune regulation. Thymic stromal lymphopoietin (TSLP), an immune regulator, has been previously associated with AD.

OBJECTIVE

To fine map TSLP and evaluate associations with the onset and persistence of AD.

METHODS

TSLP variation was determined using targeted massively parallel sequencing in a longitudinal cohort of children with AD. Evaluations included linkage disequilibrium and the persistence of AD for as many as 10 years of follow-up. The association between the presence of AD and rs1898671 variation was evaluated in a second independent cohort.

RESULTS

The minor variant frequency for rs1898671 was 23.5% (95% CI, 21.4%-25.8%). This variant was not in linkage disequilibrium with other TSLP variants in the longitudinal cohort (n = 741). White children with AD were less likely to have rs1898671 variant (odds ratio [OR], 1.41; 95% CI, 1.20-1.66) than Genome Aggregation Database controls. Children with AD and the rs1898671 variant during follow-up were more likely to have remission than children who were wild type for rs1898671 (OR, 1.56; 95% CI, 1.26-1.91). In the second cohort (n = 585), the rs1898671 variant was less prevalent in those with AD than those without. The protective effect was greater in rs1898671 heterozygotes (OR, 1.91; 95% CI, 1.34-2.75) than homozygotes (OR, 1.28; 95% CI, 0.61-2.70).

CONCLUSION

TSLP and specifically rs1898671 are important in the pathogenesis of AD and could represent a potential clinical target for the development of therapies to treat individuals with AD.

TSLP Protects Corneas From Pseudomonas aeruginosa Infection by Regulating Dendritic Cells and IL-23-IL-17 Pathway

Purpose

We sought to determine the role of epithelium-produced thymic stromal lymphopoietin (TSLP) and its underlying mechanisms in corneal innate immune defense against Pseudomonas (P.) aeruginosa keratitis.

Methods

The expression of TSLP and TSLPR in cultured human corneal epithelial cells (HCECs) and mouse corneas was determined by PCR, Western, and/or ELISA. Cellular localization of TSLP receptor (TSLPR) was determined by whole mount confocal microscopy. TSLP-TSLPR signaling was downregulated by neutralizing antibodies and/or small interfering (si)RNA; their effects on the severity of P. aeruginosa–keratitis and cytokine expression were assessed using clinical scoring, bacterial counting, PMN infiltration, and real-time PCR. The role of dendritic cells (DCs) in corneal innate immunity was determined by local DC depletion using CD11c-DTR mice.

Results

P. aeruginosa–infection induced the expression of TSLP and TSLPR in both cultured primary HCECs and in C57BL/6 mouse corneas. While TSLP was mostly expressed by epithelial cells, CD11c-positive cells were positive for TSLPR. Targeting TSLP or TSLPR with neutralizing antibodies or TSLPR with siRNA resulted in more severe keratitis, attributable to an increase in bacterial burden and PMN infiltration. TSLPR neutralization significantly suppressed infection-induced TSLP and interleukin (IL)-17C expression and augmented the expression of IL-23 and IL-17A. Local depletion of DCs markedly increased the severity of keratitis and exhibited no effects on TSLP and IL-23 expression while suppressing IL-17A and C expression in P. aeruginosa–infected corneas.

Conclusions

The epithelium-expressed TSLP plays a protective role in P. aeruginosa keratitis through targeting of DCs and in an IL-23/IL-17 signaling pathway-related manner.

Triintsin, a human pathogenic fungus-derived defensin with broad-spectrum antimicrobial activity

Since there is a symbiotic and competitive relationship between microorganisms in the same ecological niche, fungal defensins have been found to be important resources for antimicrobial peptides. Here, a fungal defensin, triintsin, was characterized in a clinical isolate of Trichophyton interdigitale from a patient with onychomycosis. The comparison of its genomic and mRNA sequences showed the gene organization and structure of three coding exons separated by two introns. The precursor peptide of triintsin contained 85 amino acid residues, which were composed of three parts including an N-terminal signal domain of 21 residues, a pro-peptide of 47 residues that ended at lysine-arginine and a mature peptide of 38 residues at the C-terminus. The 3D-structure established by homology modeling revealed that triintsin presented a representative typical cysteine-stabilized α-helical and β-sheet fold. The reductive linear peptide of triintsin was obtained by chemical synthesis. After cyclization to form three pairs of disulfide bonds, the oxidative-type peptide displayed broad-spectrum antimicrobial activity against both gram-positive and gram-negative bacteria but also showed anti-fungal activity. Moreover, triintsin can effectively inhibit the growth of clinical strains. Altogether, the peptide is a human pathogenic fungus-derived defensin with broad-spectrum antimicrobial activity.

Thymic Stromal Lymphopoietin Isoforms, Inflammatory Disorders, and Cancer

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine originally isolated from a murine thymic stromal cell line. TSLP exerts its biological effects by binding to a high-affinity heteromeric complex composed of thymic stromal lymphopoietin receptor chain and IL-7Rα. TSLP is primarily expressed by activated lung and intestinal epithelial cells, keratinocytes, and fibroblasts. However, dendritic cells (DCs), mast cells, and presumably other immune cells can also produce TSLP. Different groups of investigators have demonstrated the existence of two variants for TSLP in human tissues: the main isoform expressed in steady state is the short form (sf TSLP), which plays a homeostatic role, whereas the long form (lfTSLP) is upregulated in inflammatory conditions. In addition, there is evidence that in pathological conditions, TSLP can be cleaved by several endogenous proteases. Several cellular targets for TSLP have been identified, including immune (DCs, ILC2, T and B cells, NKT and Treg cells, eosinophils, neutrophils, basophils, monocytes, mast cells, and macrophages) and non-immune cells (platelets and sensory neurons). TSLP has been originally implicated in a variety of allergic diseases (e.g., atopic dermatitis, bronchial asthma, eosinophilic esophagitis). Emerging evidence indicates that TSLP is also involved in chronic inflammatory (i.e., chronic obstructive pulmonary disease and celiac disease) and autoimmune (e.g., psoriasis, rheumatoid arthritis) disorders and several cancers. These emerging observations greatly widen the role of TSLP in different human diseases. Most of these studies have not used tools to analyze the expression of the two TSLP isoforms. The broad pathophysiologic profile of TSLP has motivated therapeutic targeting of this cytokine. Tezepelumab is a first-in-class human monoclonal antibody (1) that binds to TSLP inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety and efficacy. Several clinical trials are evaluating the safety and the efficacy of tezepelumab in different inflammatory disorders. Monoclonal antibodies used to neutralize TSLP should not interact or hamper the homeostatic effects of sf TSLP.

Expression and Regulation of Thymic Stromal Lymphopoietin and Thymic Stromal Lymphopoietin Receptor Heterocomplex in the Innate-Adaptive Immunity of Pediatric Asthma

Asthma is a chronic inflammatory disease affecting the airway, and it is characterized by a wheezing breathing sound, variable airflow obstruction and the presence of inflammatory cells in the submucosa of the bronchi. Viral infection, pollutants and sensitivity to aeroallergens damage the epithelium from childhood, which causes asthma. The pathogenesis of asthma includes pathways of innate stimulation by environmental microbes and irritant pathogens. Damaged epithelial cells produce thymic stromal lymphopoietin (TSLP) and stimulate myeloid dendritic cell maturation through the thymic stromal lymphopoietin receptor (TSLPR) heterocomplex. TSLP-activated myeloid dendritic cells promote naive CD4⁺ T cells to differentiate into T helper type 2 (Th2) phenotype CD4⁺ T cells. Re-exposure to allergens or environmental stimuli causes an adaptive immune response. TSLP-activated dendritic cells expressing the OX40 ligand (OX40L; CD252) trigger naive CD4⁺ T cells to differentiate into inflammatory Th2 effector cells secreting the cytokines interleukin-4, 5, 9, and 13 (IL-4, IL-5, IL-9 and IL-13), and the dendritic cells (DCs) promote the proliferation of allergen-specific Th2 memory cells. Allergen presentation by Th2 cells through its interaction with their receptors in the presence of major histocompatibility complex (MHC) class II on B cells and through costimulation involving CD40 and CD40L interactions results in immunoglobulin class switching from IgM to IgE. DCs and other blood cell subsets express the TSLPR heterocomplex. The regulatory mechanism of the TSLPR heterocomplex on these different cell subsets remains unclear. The TSLPR heterocomplex is composed of the IL-7Rα chain and TSLPR chain. Moreover, two isoforms of TSLP, short isoform TSLP (sfTSLP) and long isoform TSLP (lfTSLP), have roles in atopic and allergic development. Identifying and clarifying the regulation of TSLPR and IL-7Rα in pediatric asthma are still difficult, because the type of blood cell and the expression for each blood cell in different stages of atopic diseases are poorly understood. We believe that further integrated assessments of the regulation mechanism of the TSLP–TSLPR heterocomplex axis in vitro and in vivo can provide a faster and earlier diagnosis of pediatric asthma and promote the development of more effective preventive strategies at the onset of allergies.

High-Throughput Identification of Antimicrobial Peptides from Amphibious Mudskippers

Widespread existence of antimicrobial peptides (AMPs) has been reported in various animals with comprehensive biological activities, which is consistent with the important roles of AMPs as the first line of host defense system. However, no big-data-based analysis on AMPs from any fish species is available. In this study, we identified 507 AMP transcripts on the basis of our previously reported genomes and transcriptomes of two representative amphibious mudskippers, Boleophthalmus pectinirostris (BP) and Periophthalmus magnuspinnatus (PM). The former is predominantly aquatic with less time out of water, while the latter is primarily terrestrial with extended periods of time on land. Within these identified AMPs, 449 sequences are novel; 15 were reported in BP previously; 48 are identically overlapped between BP and PM; 94 were validated by mass spectrometry. Moreover, most AMPs presented differential tissue transcription patterns in the two mudskippers. Interestingly, we discovered two AMPs, hemoglobin β1 and amylin, with high inhibitions on Micrococcus luteus. In conclusion, our high-throughput screening strategy based on genomic and transcriptomic data opens an efficient pathway to discover new antimicrobial peptides for ongoing development of marine drugs.

The Expression of the Short Isoform of Thymic Stromal Lymphopoietin in the Colon Is Regulated by the Nuclear Receptor Peroxisome Proliferator Activated Receptor-Gamma and Is Impaired during Ulcerative Colitis

The etiology of inflammatory bowel diseases remains largely unknown. We previously demonstrated that the expression of the peroxisome proliferator activated receptor-gamma (PPARγ) is downregulated in colonic epithelial cells of patients with ulcerative colitis (UC). PPARγ is a nuclear receptor that modulates inflammation. We hypothesized that its deficiency may play a role in the loss of intestinal homeostasis through the control of immunomodulatory factors. We found that thymic stromal lymphopoietin (TSLP), an epithelial cytokine with pleiotropic functions, is regulated by PPARγ. While this cytokine possesses two isoforms, only the short form (sfTSLP) was regulated by PPARγ. sfTSLP mRNA expression was decreased both in PPARγ knock-down Caco2 cells and cells treated with PPARγ antagonist, whereas PPARγ agonists induced the expression of sfTSLP in Caco2 and T-84 cells. The response element activated by PPARγ was identified in the promoter of the sfTSLP gene by chromatin immunoprecipitation and gene reporter assays. The expression of sfTSLP was significantly decreased in the colonic mucosa of UC patients compared to controls and was correlated with PPARγ expression. Our results identified sfTSLP as a new PPARγ-target gene and support the hypothesis that, in UC, PPARγ deficiency in colonic mucosa could play a role in the loss of intestinal tolerance through an impaired sfTSLP expression.

Phenotypic and genetic aspects of epithelial barrier function in asthmatic patients

The bronchial epithelium is continuously exposed to a multitude of noxious challenges in inhaled air. Cellular contact with most damaging agents is reduced by the action of the mucociliary apparatus and by formation of a physical barrier that controls passage of ions and macromolecules. In conjunction with these defensive barrier functions, immunomodulatory cross-talk between the bronchial epithelium and tissue-resident immune cells controls the tissue microenvironment and barrier homeostasis. This is achieved by expression of an array of sensors that detect a wide variety of viral, bacterial, and nonmicrobial (toxins and irritants) agents, resulting in production of many different soluble and cell-surface molecules that signal to cells of the immune system. The ability of the bronchial epithelium to control the balance of inhibitory and activating signals is essential for orchestrating appropriate inflammatory and immune responses and for temporally modulating these responses to limit tissue injury and control the resolution of inflammation during tissue repair. In asthmatic patients abnormalities in many aspects of epithelial barrier function have been identified. We postulate that such abnormalities play a causal role in immune dysregulation in the airways by translating gene-environment interactions that underpin disease pathogenesis and exacerbation.

The etiopathogenesis of atopic dermatitis: barrier disruption, immunological derangement, and pruritus

Atopic dermatitis (AD) is a common chronic skin inflammatory disorder characterized by recurrent eczema accompanied by an intractable itch that leads to an impaired quality of life. Extensive recent studies have shed light on the multifaceted pathogenesis of the disease. The complex interplay among skin barrier deficiency, immunological derangement, and pruritus contributes to the development, progression, and chronicity of the disease. Abnormalities in filaggrin, other stratum corneum constituents, and tight junctions induce and/or promote skin inflammation. This inflammation, in turn, can further deteriorate the barrier function by downregulating a myriad of essential barrier-maintaining molecules. Pruritus in AD, which may be due to hyperinnervation of the epidermis, increases pruritogens, and central sensitization compromises the skin integrity and promotes inflammation. There are unmet needs in the treatment of AD. Based on the detailed evidence available to date, certain disease mechanisms can be chosen as treatment targets. Numerous clinical trials of biological agents are currently being conducted and are expected to provide treatments for patients suffering from AD in the future. This review summarizes the etiopathogenesis of the disease and provides a rationale for choosing the novel targeted therapy that will be available in the future.