Genetic association analyses of atopic illness and proinflammatory cytokine genes with type 1 diabetes

Overexpression of ORMDL3 confers sexual dimorphism in diet-induced non-alcoholic steatohepatitis

OBJECTIVE

The bioactive sphingolipid metabolites ceramide and sphingosine-1-phosphate (S1P) accumulate with overnutrition and have been implicated in non-alcoholic steatohepatitis (NASH) development. ORMDL3, a negative regulator of the rate-limiting step in ceramide biosynthesis, has been identified as an obesity-related gene. Therefore, we assessed the role of ORMDL3 in diet-induced obesity and development of NASH.

METHODS

Globally overexpressing Ormdl3-Flag transgenic mice (ORMDL3TG) were fed a western high-fat, carbohydrate and cholesterol enriched diet, with high fructose-glucose drinking water. Physiological, biochemical and sphingolipidomic analyses were employed to measure the effect of ORMDL3 overexpression on NASH development.

RESULTS

ORMDL3TG male but not female mice fed a western high-fat diet and sugar water had exacerbated adipocyte hypertrophy together with increased severity of white adipose inflammation and fibrosis. Hepatic steatosis, dyslipidemia, impaired glucose homeostasis, hyperinsulinemia, and insulin resistance were significantly more severe only in obese ORMDL3TG male mice that accompanied dramatic liver fibrosis, inflammation, and formation of hepatic crown-like structures, which are unique features of human and murine NASH. Obesogenic diet induces ORMDL expression in male mice but reduces it in females. Mechanistically, overexpression of Ormdl3 lowered the levels of S1P and ceramides only in obese female mice and antithetically increased them in tissues of obese males. ORMDL3TG male mice exhibited a much greater induction of the UPR, propagating ER stress that contributed to their early development of NASH.

CONCLUSIONS

This study uncovered a previously unrecognized role for ORMDL3 in sexual dimorphism important for the development and progression of NASH.

GSDMA3 deficiency reprograms cellular metabolism and modulates BCR signaling in murine B cells

Metabolism plays a crucial role in B cell differentiation and function. GSDMA3 is related to mitochondrial metabolism and is involved in immune responses. Here, we used Gsdma3 KO mice to examine the effect of GSDMA3 on B cells. The results demonstrated that GSDMA3 deficiency reprogrammed B cell metabolism, evidenced by upregulating PI3K-Akt-mTOR signaling, along with elevated ROS reproduction and reduced maximal oxygen consumption rate in mitochondria. Moreover, the BCR signaling in the KO B cells was impaired. The reduced BCR signaling was associated with decreased BCR clustering, caused by inhibited activation of WASP. However, GSDMA3 deficiency had no effects on B cell development and functions in humoral immunity, which might be associated with the compensation of upregulated GSDMA2 expression and the fine balance between PI3K signaling and BCR signals interaction. Our observations reveal a previously unknown influence of GSDMA3 on B cells under physiological and immunized states.

Juvenile idiopathic arthritis-associated genetic loci exhibit spatially constrained gene regulatory effects across multiple tissues and immune cell types

Juvenile idiopathic arthritis (JIA) is an autoimmune, inflammatory joint disease with complex genetic etiology. Previous GWAS have found many genetic loci associated with JIA. However, the biological mechanism behind JIA remains unknown mainly because most risk loci are located in non-coding genetic regions. Interestingly, increasing evidence has found that regulatory elements in the non-coding regions can regulate the expression of distant target genes through spatial (physical) interactions. Here, we used information on the 3D genome organization (Hi-C data) to identify target genes that physically interact with SNPs within JIA risk loci. Subsequent analysis of these SNP-gene pairs using data from tissue and immune cell type-specific expression quantitative trait loci (eQTL) databases allowed the identification of risk loci that regulate the expression of their target genes. In total, we identified 59 JIA-risk loci that regulate the expression of 210 target genes across diverse tissues and immune cell types. Functional annotation of spatial eQTLs within JIA risk loci identified significant overlap with gene regulatory elements (i.e., enhancers and transcription factor binding sites). We found target genes involved in immune-related pathways such as antigen processing and presentation (e.g., ERAP2, HLA class I and II), the release of pro-inflammatory cytokines (e.g., LTBR, TYK2), proliferation and differentiation of specific immune cell types (e.g., AURKA in Th17 cells), and genes involved in physiological mechanisms related to pathological joint inflammation (e.g., LRG1 in arteries). Notably, many of the tissues where JIA-risk loci act as spatial eQTLs are not classically considered central to JIA pathology. Overall, our findings highlight the potential tissue and immune cell type-specific regulatory changes contributing to JIA pathogenesis. Future integration of our data with clinical studies can contribute to the development of improved JIA therapy.

Regulation of gasdermins in pyroptosis and cytokine release

Gasdermins are effectors of pyroptosis downstream of diverse signaling pathways. Emerging evidence suggests that a number of post-translational modifications regulate the function of gasdermins in pyroptosis, a highly inflammatory form of cell death, and lytic or non-lytic secretion of intracellular contents. These include processing by different caspases and other proteases that may activate or suppress pyroptosis, ubiquitination by a bacterial E3 ligase that suppresses pyroptosis as an immune evasion mechanism, modifications at Cys residues in mammalian or microbial gasdermins that promote or inhibit pyroptosis, and potential phosphorylation that represses pyroptosis. Such diverse regulatory mechanisms by host and microbial proteases, ubiquitin ligases, acyltransferases, kinases and phosphatases may underlie the divergent physiological and pathological functions of gasdermins, and furnish opportunities for therapeutic targeting of gasdermins in infectious diseases and inflammatory disorders.

Insights into the GSDMB-mediated cellular lysis and its targeting by IpaH7.8

The multifunctional GSDMB protein is an important molecule in human immunity. The pyroptotic and bactericidal activity of GSDMB is a host response to infection by the bacterial pathogen Shigella flexneri, which employs the virulence effector IpaH7.8 to ubiquitinate and target GSDMB for proteasome-dependent degradation. Furthermore, IpaH7.8 selectively targets human but not mouse GSDMD, suggesting a non-canonical mechanism of substrate selection. Here, we report the crystal structure of GSDMB in complex with IpaH7.8. Together with biochemical and functional studies, we identify the potential membrane engagement sites of GSDMB, revealing general and unique features of gasdermin proteins in membrane recognition. We further illuminate how IpaH7.8 interacts with GSDMB, and delineate the mechanism by which IpaH7.8 ubiquitinates and suppresses GSDMB. Notably, guided by our structural model, we demonstrate that two residues in the α1-α2 loop make the mouse GSDMD invulnerable to IpaH7.8-mediated degradation. These findings provide insights into the versatile functions of GSDMB, which could open new avenues for therapeutic interventions for diseases, including cancers and bacterial infections.

Gasdermins in Innate Host Defense Against Entamoeba histolytica and Other Protozoan Parasites

Gasdermins (GSDMs) are a group of proteins that are cleaved by inflammatory caspases to induce pore formation in the plasma membrane to cause membrane permeabilization and lytic cell death or pyroptosis. All GSDMs share a conserved structure, containing a cytotoxic N-terminal (NT) pore-forming domain and a C-terminal (CT) repressor domain. Entamoeba histolytica (Eh) in contact with macrophages, triggers outside-in signaling to activate inflammatory caspase-4/1 via the noncanonical and canonical pathway to promote cleavage of gasdermin D (GSDMD). Cleavage of GSDMD removes the auto-inhibition that masks the active pore-forming NT domain in the full-length protein by interactions with GSDM-CT. The cleaved NT-GSDMD monomers then oligomerize to form pores in the plasma membrane to facilitate the release of IL-1β and IL-18 with a measured amount of pyroptosis. Pyroptosis is an effective way to counteract intracellular parasites, which exploit replicative niche to avoid killing. To date, most GSDMs have been verified to perform pore-forming activity and GSDMD-induced pyroptosis is rapidly emerging as a mechanism of anti-microbial host defence. Here, we review our comprehensive and current knowledge on the expression, activation, biological functions, and regulation of GSDMD cleavage with emphases on physiological scenario and related dysfunctions of each GSDM member as executioner of cell death, cytokine secretion and inflammation against Eh and other protozoan parasitic infections.

Role of Pyroptosis in Inflammatory Bowel Disease (IBD): From Gasdermins to DAMPs

Pyroptosis is a pro-inflammatory cell death executed by gasdermin family proteins that involve the formation of pores on cells, recognition of danger signals, and release of pro-inflammatory cytokines IL-1β and IL-18. Pyroptosis modulates mucosal innate immunity and enteropathogenic bacterial infection. Similarly, the gasdermin family has been reported to be involved in the defense of the intestinal epithelium against bacterial infection and in the regulation of intestinal inflammation. Pyroptosis initiates damage signals that activate multiple pathways to cause inflammation, which may be a potential cause of chronic intestinal inflammation. In this review, we discuss the impact of pyroptosis on inflammatory bowel disease (IBD), with a focus on the executive proteins of pyroptosis (GSDMB, GADMD, and GSDME) and IBD-related endogenous damage-associated molecular patterns (DAMPs) produced by pyroptosis.

Ablation of ORMDL3 impairs adipose tissue thermogenesis and insulin sensitivity by increasing ceramide generation

Objective

Genome-wide association studies identified ORMDL3 as an obesity-related gene, and its expression was negatively correlated with body mass index. However, the precise biological roles of ORMDL3 in obesity and lipid metabolism remain uncharacterized. Here, we investigate the function of ORMDL3 in adipose tissue thermogenesis and high fat diet (HFD)-induced insulin resistance.

Methods

Ormdl3-deficient (Ormdl3^−/−) mice were employed to delineate the function of ORMDL3 in brown adipose tissue (BAT) thermogenesis and white adipose tissue (WAT) browning. Glucose and lipid homeostasis in Ormdl3^−/− mice fed a HFD were assessed. The lipid composition in adipose tissue was evaluated by mass spectrometry. Primary adipocytes in culture were used to determine the mechanism by which ORMDL3 regulates white adipose browning.

Results

BAT thermogenesis and WAT browning were significantly impaired in Ormdl3^−/− mice upon cold exposure or administration with the β3 adrenergic agonist. In addition, compared to WT mice, Ormdl3^−/− mice displayed increased weight gain and insulin resistance in response to HFD. The induction of uncoupling protein 1 (UCP1), a marker of thermogenesis, was attenuated in primary adipocytes derived from Ormdl3^−/− mice. Importantly, ceramide levels were elevated in the adipose tissue of Ormdl3^−/− mice. In addition, the reduction in thermogenesis and increase in body weight caused by Ormdl3 deficiency could be rescued by inhibiting the production of ceramides.

Conclusion

Our findings suggest that ORMDL3 contributes to the regulation of BAT thermogenesis, WAT browning, and insulin resistance.

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ORMDL3 is downregulated in WAT of obese mice and humans and upregulated in response to cold exposure.

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Loss of Ormdl3 in mice exacerbates the overall metabolic phenotypes caused by HFD-induced obesity.

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Ormdl3 ablation impairs BAT thermogenesis and WAT browning.

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Ormdl3 deficiency is sufficient for negatively regulating ceramide levels.

Pyroptosis, metabolism, and tumor immune microenvironment

In response to a wide range of stimulations, host cells activate pyroptosis, a kind of inflammatory cell death which is provoked by the cytosolic sensing of danger signals and pathogen infection. In manipulating the cleavage of gasdermins (GSDMs), researchers have found that GSDM proteins serve as the real executors and the deterministic players in fate decisions of pyroptotic cells. Whether inflammatory characteristics induced by pyroptosis could cause damage the host or improve immune activity is largely dependent on the context, timing, and response degree. Here, we systematically review current points involved in regulatory mechanisms and the multidimensional roles of pyroptosis in several metabolic diseases and the tumor microenvironment. Targeting pyroptosis may reveal potential therapeutic avenues.

Association between Gasdermin A, Gasdermin B Polymorphisms and Allergic Rhinitis Amongst Jordanians

BACKGROUND

Gasdermin A (GSDMA) and Gasdermin B (GSDMB) have been associated with childhood and to a lesser extent with adult asthma in many populations. In this study, we investigate whether there is an association between GSDMA (rs7212938, T/G) and GSDMB (rs7216389, T/C) at locus 17q21.2 and risk of Allergic Rhinitis among Jordanians. Also, we aimed to determine if there is an association between such polymorphisms and the IgE level.

METHODS

The study included 112 rhinitis patients and 111 Healthy controls. Gasdermin A (GSDMA) (rs7212938, T/G) and Gasdermin B (rs7216389, T/C) polymorphisms were genotyped using the PCRRFLP method.

RESULTS

On the genotype level, three analysis models were applied namely co-dominant, dominant and recessive genotypes. GSDMB CC genotype was found to have a significant protective effect against allergic Rhinitis (< 0.05). cc genotype was also significantly associated with higher IgE level among the studied population.

CONCLUSION

The GSDMB CC of homozygous minor genotype showed a protective effect against Allergic rhinitis. It also was found to be significantly associated with lower IgE level among the studied population. No association was found between GSDMA with the risk of allergic Rhinitis.

The Cross-Talk Between Atopic Dermatitis and Diabetes Mellitus: A Meta-Analysis

INTRODUCTION

Atopic dermatitis (AD) is associated with various systemic diseases. However, its association with diabetes mellitus (DM) was discussed controversially. Few researchers reviewed the association of these two common morbid disorders. This meta-analysis aimed to assess the relationship between AD and DM.

METHODS

We systematically searched PubMed including Epub and ahead of print (198 articles identified) and Cochrane (13 articles) databases. The searching engine was set to include case-control, prospective and retrospective cohorts, and cross-sectional studies from the first published up to February 12, 2021. Two hundred and eleven were identified, eighteen full texts were screened; of them, six were included in the final meta-analysis. The keywords used were AD, diabetes mellitus, type 1 diabetes, and type 2 diabetes. A datasheet was used to record the author's name, year of publication, country and type of the studies, number of events, and total number in the two arms (patients and controls).

RESULTS

Out of the 211 references identified, six studies were pooled to test the association between diabetes mellitus and AD. The studies showed that AD is lower among patients with DM, odds ratio, 0.69, 95% CI, and 0.67-0.72. No heterogeneity was observed (Chi-Square, 4.12, degree of freedom (df.)= 5, and I² = 0%, P-value), 0.53 and P-value for overall effect, <0.001. The included studies were published in Europe (five) and Canada (one study) and included 162,882 patients and 12,164 events, four of the studied articles were case-control studies, one retrospective, and one cross-sectional.

CONCLUSION

AD was lower among patients with DM compared to their counterparts without the disease. Further studies focusing on the genetic and environmental factors linking AD and diabetes are needed.

Identification and analysis of splicing quantitative trait loci across multiple tissues in the human genome

Alternative splicing (AS) is a fundamental step in eukaryotic mRNA biogenesis. Here, we develop an efficient and reproducible pipeline for the discovery of genetic variants that affect AS (splicing QTLs, sQTLs). We use it to analyze the GTEx dataset, generating a comprehensive catalog of sQTLs in the human genome. Downstream analysis of this catalog provides insight into the mechanisms underlying splicing regulation. We report that a core set of sQTLs is shared across multiple tissues. sQTLs often target the global splicing pattern of genes, rather than individual splicing events. Many also affect the expression of the same or other genes, uncovering regulatory loci that act through different mechanisms. sQTLs tend to be located in post-transcriptionally spliced introns, which would function as hotspots for splicing regulation. While many variants affect splicing patterns by altering the sequence of splice sites, many more modify the binding sites of RNA-binding proteins. Genetic variants affecting splicing can have a stronger phenotypic impact than those affecting gene expression.

Genetic Regulation of Immunoglobulin G Glycosylation

Defining the genetic components that control glycosylation of the human immunoglobulin G (IgG) is an ongoing effort, which has so far been addressed by means of heritability, linkage and genome-wide association studies (GWAS). Unlike the synthesis of proteins, N-glycosylation biosynthesis is not a template-driven process, but rather a complex process regulated by both genetic and environmental factors. Current heritability studies have shown that while up to 75% of the variation in levels of some IgG glycan traits can be explained by genetics, some glycan traits are completely defined by environmental influences. Advances in both high-throughput genotyping and glycan quantification methods have enabled genome-wide association studies that are increasingly used to estimate associations of millions of single-nucleotide polymorphisms and glycosylation traits. Using this method, 18 genomic regions have so far been robustly associated with IgG N-glycosylation, discovering associations with genes encoding glycosyltransferases, but also transcription factors, co-factors, membrane transporters and other genes with no apparent role in IgG glycosylation. Further computational analyses have shown that IgG glycosylation is likely to be regulated through the expression of glycosyltransferases, but have also for the first time suggested which transcription factors are involved in the process. Moreover, it was also shown that IgG glycosylation and inflammatory diseases share common underlying causal genetic variants, suggesting that studying genetic regulation of IgG glycosylation helps not only to better understand this complex process but can also contribute to understanding why glycans are changed in disease. However, further studies are needed to unravel whether changes in IgG glycosylation are causing these diseases or the changes in the glycome are caused by the disease.

The association of genetic variants IL2RA rs2104286, IFI30 rs11554159 and IKZF3 rs12946510 with multiple sclerosis onset and severity in patients from Serbia

An algorithm Probabilistic Identification of Causal SNPs, identified 434 causal variants for multiple sclerosis (MS) including IL2RA rs2104286, IFI30 rs11554159 and IKZF3 rs12946510. Analysis of individual and combined effects of these variants in the Serbian population identified that Il2RA rs2104286 G allele carriers had a lower risk for developing MS (gender adjusted OR = 0.63, p = .003). With regard to the IFI30 rs11554159 recessive genetic model, among HLA-DRB1*15:01 positive patients, the AA homozygote had a significantly higher MSSS compared to the G allele carriers (p = .003). This study confirms role of IL2RA rs2104286 in MS and suggest the role of IFI30 rs11554159 in disease severity, which needs validation.

GSDMB promotes non-canonical pyroptosis by enhancing caspase-4 activity

Gasdermin B (GSDMB) has been reported to be associated with immune diseases in humans, but the detailed molecular mechanisms remain unsolved. The N-terminus of GSDMB by itself, unlike other gasdermin family proteins, does not induce cell death. Here, we show that GSDMB is highly expressed in the leukocytes of septic shock patients, which is associated with increased release of the gasdermin D (GSDMD) N-terminus. GSDMB expression and the accumulation of the N-terminal fragment of GSDMD are induced by the activation of the non-canonical pyroptosis pathway in a human monocyte cell line. The downregulation of GSDMB alleviates the cleavage of GSDMD and cell death. Consistently, the overexpression of GSDMB promotes GSDMD cleavage, accompanied by increased LDH release. We further found that GSDMB promotes caspase-4 activity, which is required for the cleavage of GSDMD in non-canonical pyroptosis, by directly binding to the CARD domain of caspase-4. Our study reveals a GSDMB-mediated novel regulatory mechanism for non-canonical pyroptosis and suggests a potential new strategy for the treatment of inflammatory diseases.

Treatment of Allergic Asthma with Fenretinide Formulation (LAU-7b) Downregulates ORMDL Sphingolipid Biosynthesis Regulator 3 (Ormdl3) Expression and Normalizes Ceramide Imbalance

Zona pellucida binding protein 2 (Zpbp2) and ORMDL sphingolipid biosynthesis regulator 3 (Ormdl3), mapped downstream of Zpbp2, were identified as two genes associated with airway hyper-responsiveness (AHR). Ormdl3 gene product has been shown to regulate the biosynthesis of ceramides. Allergic asthma was shown to be associated with an imbalance between very-long-chain ceramides (VLCCs) and long-chain ceramides (LCCs). We hypothesized that Fenretinide can prevent the allergic asthma-induced augmentation of Ormdl3 gene expression, normalize aberrant levels of VLCCs and LCCs, and treat allergic asthma symptoms. We induced allergic asthma by house dust mite (HDM) in A/J WT mice and Zpbp2 KO mice expressing lower levels of Ormdl3 mRNA than WT. We investigated the effect of a novel formulation of Fenretinide, LAU-7b, on the AHR, inflammatory cell infiltration, mucus production, IgE levels, and ceramide levels. Although lower Ormdl3 expression, which was observed in Zpbp2 KO mice, was associated with lower AHR, allergic Zpbp2 KO mice were not protected from inflammatory cell infiltration, mucus accumulation, or aberrant levels of VLCCs and LCCs induced by HDM. LAU-7b treatment protects both the Zpbp2 KO and WT mice. The treatment significantly lowers the gene expression of Ormdl3, normalizes the VLCCs and LCCs, and corrects all the other phenotypes associated with allergic asthma after HDM challenge, except the elevated levels of IgE. LAU-7b treatment prevents the augmentation of Ormdl3 expression and ceramide imbalance induced by HDM challenge and protects both WT and Zpbp2 KO mice against allergic asthma symptoms. SIGNIFICANCE STATEMENT: Compared with A/J WT mice, KO mice with Zpbp2 gene deletion have lower AHR and lower levels of Ormdl3 expression. The novel oral clinical formulation of Fenretinide (LAU-7b) effectively lowers the AHR and protects against inflammatory cell infiltration and mucus accumulation induced by house dust mite in both Zpbp2 KO and WT A/J mice. LAU-7b prevents Ormdl3 overexpression in WT allergic mice and corrects the aberrant levels of very-long-chain and long-chain ceramides in both WT and Zpbp2 KO allergic mice.

Familial Coaggregation of Asthma and Type 1 Diabetes in Children

IMPORTANCE

The association between atopic and autoimmune disease, particularly asthma and type 1 diabetes, has been debated. Further understanding of the underlying factors associated with the comorbidity in children is warranted.

OBJECTIVES

To assess the bidirectional association between asthma and type 1 diabetes and examine the possibility of a shared risk for the diseases by studying their pattern of familial coaggregation.

DESIGN, SETTING, AND PARTICIPANTS

A birth cohort study of children born from January 1, 2001, and followed up until December 31, 2015, was performed. Population data were obtained from multiple national Swedish registers. A total of 1 347 901 singleton children, live-born in Sweden between January 1, 2001, and December 31, 2013, were identified, and children with incomplete data were excluded. The remaining 1 284 748 children were linked to their biological full siblings, maternal and paternal half-siblings, cousins, and half-cousins. Data analysis was conducted from April 1, 2019, to January 17, 2020.

MAIN OUTCOMES AND MEASURES

Cases of asthma and type 1 diabetes were defined using a combination of diagnoses and medication prescriptions found in the registers.

RESULTS

In the cohort of 1 284 748 children, 660 738 children (51.4%) were boys; 121 809 children (9.5%) had asthma, 3812 children (0.3%) had type 1 diabetes, and 494 children had both asthma and type 1 diabetes, representing 0.4% of all asthma or 13% of all type 1 diabetes. Mean (SD) age at diagnosis was 3.0 (2.8) years for children with asthma, and 5.9 (3.3) years for those with type 1 diabetes. Asthma and type 1 diabetes were associated within individuals (odds ratio, 1.15; 95% CI, 1.05-1.27). Children with asthma had an increased risk of subsequent type 1 diabetes (hazard ratio, 1.16; 95% CI, 1.06-1.27); however, subsequent asthma risk did not differ substantially among children with type 1 diabetes (hazard ratio, 0.92; 95% CI, 0.75-1.12). Siblings of individuals with asthma were at an increased risk of type 1 diabetes (odds ratio, 1.27; 95% CI, 1.13-1.42) and vice versa. The results remained positive after controlling for the direct association of one disease with the other.

CONCLUSIONS AND RELEVANCE

This study appears to provide evidence for co-occurrence, importance of sequential appearance, and coaggregation of asthma and type 1 diabetes in children and their siblings. The findings may suggest shared familial factors contributing to the associations. Knowledge of the nature of the association could be of importance in future clinical practice.

Bacteroidetes and Firmicutes levels in gut microbiota and effects of hosts TLR2/TLR4 gene expression levels in adult type 1 diabetes patients in Istanbul, Turkey

AIM

The aim of this study was to determine and compare the levels of both Bacteroidetes and Firmicutes in the gut microbiota and TLR2/TLR4 gene expression in the blood of patients with type 1 diabetes mellitus (T1DM) and healthy individuals. These results may serve as a preliminary assessment to guide future research.

METHOD

Between January and October 2014, stool and blood samples were collected from 53 adult T1DM patients and 53 age- and gender-matched healthy individuals. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and TLR2 and TLR4 expression levels were analyzed via qPCR using RNA from EDTA blood samples from both patients and healthy controls.

RESULTS

The amounts of Bacteroidetes and Firmicutes were statistically significantly higher and lower, respectively, in the T1DM group than in the healthy control group (p < 0.001 and p < 0.001, respectively). In addition, the Firmicutes/Bacteroidetes ratios in patients with T1DM were significantly lower than in healthy controls. The TLR4 and TLR2 gene expression levels in T1DM patients were significantly upregulated and downregulated, respectively, compared to those in the control group.

CONCLUSION

Our data are the first to show a relationship between T1DM and gut microbiota in our country. In addition, our results provide information about the connections between T1DM, gut microbiota, and TLR2 and TLR4 expression. We believe that Bacteroidetes and Firmicutes in the gut microbiota may play a role in the autoimmune process of T1DM and that these findings should be further investigated in the future.

What did we learn from multiple omics studies in asthma?

More than a decade has passed since the finalization of the Human Genome Project. Omics technologies made a huge leap from trendy and very expensive to routinely executed and relatively cheap assays. Simultaneously, we understood that omics is not a panacea for every problem in the area of human health and personalized medicine. Whilst in some areas of research omics showed immediate results, in other fields, including asthma, it only allowed us to identify the incredibly complicated molecular processes. Along with their possibilities, omics technologies also bring many issues connected to sample collection, analyses and interpretation. It is often impossible to separate the intrinsic imperfection of omics from asthma heterogeneity. Still, many insights and directions from applied omics were acquired-presumable phenotypic clusters of patients, plausible biomarkers and potential pathways involved. Omics technologies develop rapidly, bringing improvements also to asthma research. These improvements, together with our growing understanding of asthma subphenotypes and underlying cellular processes, will likely play a role in asthma management strategies.

Novel interconnections of HOG signaling revealed by combined use of two proteomic software packages

Modern quantitative mass spectrometry (MS)-based proteomics enables researchers to unravel signaling networks by monitoring proteome-wide cellular responses to different stimuli. MS-based analysis of signaling systems usually requires an integration of multiple quantitative MS experiments, which remains challenging, given that the overlap between these datasets is not necessarily comprehensive. In a previous study we analyzed the impact of the yeast mitogen-activated protein kinase (MAPK) Hog1 on the hyperosmotic stress-affected phosphorylome. Using a combination of a series of hyperosmotic stress and kinase inhibition experiments, we identified a broad range of direct and indirect substrates of the MAPK. Here we re-evaluate this extensive MS dataset and demonstrate that a combined analysis based on two software packages, MaxQuant and Proteome Discoverer, increases the coverage of Hog1-target proteins by 30%. Using protein-protein proximity assays we show that the majority of new targets gained by this analysis are indeed Hog1-interactors. Additionally, kinetic profiles indicate differential trends of Hog1-dependent versus Hog1-independent phosphorylation sites. Our findings highlight a previously unrecognized interconnection between Hog1 signaling and the RAM signaling network, as well as sphingolipid homeostasis.

Functional SNPs in the Human Autoimmunity-Associated Locus 17q12-21

Genome-wide association studies (GWASes) revealed several single-nucleotide polymorphisms (SNPs) in the human 17q12-21 locus associated with autoimmune diseases. However, follow-up studies are still needed to identify causative SNPs directly mediating autoimmune risk in the locus. We have chosen six SNPs in high linkage disequilibrium with the GWAS hits that showed the strongest evidence of causality according to association pattern and epigenetic data and assessed their functionality in a local genomic context using luciferase reporter system. We found that rs12946510, rs4795397, rs12709365, and rs8067378 influenced the reporter expression level in leukocytic cell lines. The strongest effect visible in three distinct cell types was observed for rs12946510 that is predicted to alter MEF2A/C and FOXO1 binding sites.

Development of atopic sensitization in Finnish and Estonian children: A latent class analysis in a multicenter cohort

BACKGROUND

The prevalence of atopy is associated with a Western lifestyle, as shown by studies comparing neighboring regions with different socioeconomic backgrounds. Atopy might reflect various conditions differing in their susceptibility to environmental factors.

OBJECTIVE

We sought to define phenotypes of atopic sensitization in early childhood and examine their association with allergic diseases and hereditary background in Finland and Estonia.

METHODS

The analysis included 1603 Finnish and 1657 Estonian children from the DIABIMMUNE multicenter young children cohort. Specific IgE levels were measured at age 3, 4, and 5 years, respectively, and categorized into 3 CAP classes. Latent class analysis was performed with the statistical software package poLCA in R software.

RESULTS

Both populations differed in terms of socioeconomic status and environmental determinants, such as pet ownership, farm-related exposure, time spent playing outdoors, and prevalence of allergic diseases (all P < .001). Nevertheless, we found similar latent classes in both populations: an unsensitized class, a food class, 2 inhalant classes differentiating between seasonal and perennial aeroallergens, and a severe atopy class. The latter was characterized by high total and specific IgE levels and strongly associated with wheeze (odds ratio [OR], 5.64 [95% CI, 3.07-10.52] and 4.56 [95% CI, 2.35-8.52]), allergic rhinitis (OR, 22.4 [95% CI, 11.67-44.54] and 13.97 [95% CI, 7.33-26.4]), and atopic eczema (OR, 9.39 [95% CI, 4.9-19.3] and 9.5 [95% CI, 5.2-17.5] for Finland and Estonia, respectively). Environmental differences were reflected in the larger seasonal inhalant atopy class in Finland, although composition of classes was comparable between countries.

CONCLUSION

Despite profound differences in environmental exposures, there might exist genuine patterns of atopic sensitization. The distribution of these patterns might determine the contribution of atopic sensitization to disease onset.

Deficiency of selenoprotein S, an endoplasmic reticulum resident oxidoreductase, impairs the contractile function of fast-twitch hindlimb muscles

Selenoprotein S (Seps1) is an endoplasmic reticulum (ER) resident antioxidant implicated in ER stress and inflammation. In human vastus lateralis and mouse hindlimb muscles, Seps1 localization and expression were fiber-type specific. In male Seps1^+/- heterozygous mice, spontaneous physical activity was reduced compared with wild-type littermates ( d = 1.10, P = 0.029). A similar trend was also observed in Seps1^-/- knockout mice ( d = 1.12, P = 0.051). Whole body metabolism, body composition, extensor digitorum longus (EDL), and soleus mass and myofiber diameter were unaffected by genotype. However, in isolated fast EDL muscles from Seps1^-/- knockout mice, the force frequency curve (FFC; 1-120 Hz) was shifted downward versus EDL muscles from wild-type littermates ( d = 0.55, P = 0.002), suggestive of reduced strength. During 4 min of intermittent, submaximal (60 Hz) stimulation, the genetic deletion or reduction of Seps1 decreased EDL force production ( d = 0.52, P < 0.001). Furthermore, at the start of the intermittent stimulation protocol, when compared with the 60-Hz stimulation of the FFC, EDL muscles from Seps1^-/- knockout or Seps1^+/- heterozygous mice produced 10% less force than those from wild-type littermates ( d = 0.31, P < 0.001 and d = 0.39, P = 0.015). This functional impairment was associated with reduced mRNA transcript abundance of thioredoxin-1 ( Trx1), thioredoxin interacting protein ( Txnip), and the ER stress markers Chop and Grp94, whereas, in slow soleus muscles, Seps1 deletion did not compromise contractile function and Trx1 ( d = 1.38, P = 0.012) and Txnip ( d = 1.27, P = 0.025) gene expression was increased. Seps1 is a novel regulator of contractile function and cellular stress responses in fast-twitch muscles.

Target highlights from the first post-PSI CASP experiment (CASP12, May-August 2016)

The functional and biological significance of the selected CASP12 targets are described by the authors of the structures. The crystallographers discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP12 experiment.

A decade of research on the 17q12-21 asthma locus: Piecing together the puzzle

Chromosome 17q12–21 remains the most highly replicated and significant asthma locus. Genotypes in the core region defined by the first genome-wide association study correlate with expression of 2 genes, ORM1-like 3 (ORMDL3) and gasdermin B (GSDMB), making these prime candidate asthma genes, although recent studies have implicated gasdermin A (GSDMA) distal to and post-GPI attachment to proteins 3 (PGAP3) proximal to the core region as independent loci. We review 10 years of studies on the 17q12–21 locus and suggest that genotype-specific risks for asthma at the proximal and distal loci are not specific to early-onset asthma and mediated by PGAP3, ORMDL3, and/or GSDMA expression. We propose that the weak and inconsistent associations of 17q single nucleotide polymorphisms with asthma in African Americans is due to the high frequency of some 17q alleles, the breakdown of linkage disequilibrium on African-derived chromosomes, and possibly different early-life asthma endotypes in these children. Finally, the inconsistent association between asthma and gene expression levels in blood or lung cells from older children and adults suggests that genotype effects may mediate asthma risk or protection during critical developmental windows and/or in response to relevant exposures in early life. Thus studies of young children and ethnically diverse populations are required to fully understand the relationship between genotype and asthma phenotype and the gene regulatory architecture at this locus. (J Allergy Clin Immunol 2018;142:749–64.)

ORMDL3 Facilitates the Survival of Splenic B Cells via an ATF6α-Endoplasmic Reticulum Stress-Beclin1 Autophagy Regulatory Pathway

The genetic association of orosomucoid-like 3 (ORMDL3) with an array of immunoinflammatory disorders has been recently unraveled in multiple ethnic groups, and functional exploration has received attention of the particular relevance of this gene in endoplasmic reticulum stress, lipid metabolism, and inflammatory response. In this study, we demonstrated the upregulation of ORMDL3 in both patients with systemic lupus erythematosus and lupus mice compared with controls. By establishing ORMDL3 knockout mice (Ormdl3^-/-), we showed that silencing Ormdl3 in vivo significantly decreased the proportions of mature B lymphocytes and transitional 2B cells in spleen and B1a cells from abdominal cavity perfusion fluid, the secretion of IgG and IgM, and the expression of Baff. Additionally, knockdown of Ormdl3 augmented the apoptosis of total splenic cells and splenic CD19⁺ B cells but did not affect B cell proliferation and cell cycle. Subsequently, we in vitro and in vivo demonstrated that ORMDL3 potentially mediates the autophagy via the ATF 6-Beclin1 autophagy pathway, and it facilitates the survival of splenic B cells via promoting autophagy and suppressing apoptosis. Taken together, we uncovered a role of ORMDL3 in fine-tuning B cell development and survival, besides highlighting a potential mechanism by which ORMDL3 regulates autophagy via ATF6 pathway.

Chromosome 17q21 Genes ORMDL3 and GSDMB in Asthma and Immune Diseases

Chromosome 17q21 contains a cluster of genes including ORMDL3 and GSDMB, which have been highly linked to asthma in genome-wide association studies. ORMDL3 is localized to the endoplasmic reticulum and regulates downstream pathways including sphingolipids, metalloproteases, remodeling genes, and chemokines. ORMDL3 inhibits serine palmitoyl-CoA transferase, the rate-limiting enzyme for sphingolipid biosynthesis. In addition, ORMDL3 activates the ATF6α branch of the unfolded protein response which regulates SERCA2b and IL-6, pathways of potential importance to asthma. The SNP-linking chromosome 17q21 to asthma is associated with increased ORMDL3 and GSDMB expression. Mice expressing either increased levels of human ORMDL3, or human GSDMB, have an asthma phenotype characterized by increased airway responsiveness and increased airway remodeling (increased smooth muscle and fibrosis) in the absence of airway inflammation. GSDMB regulates expression of 5-LO and TGF-β1 which are known pathways involved in the pathogenesis of asthma. GSDMB is one of four members of the GSDM family (GSDMA, GSDMB, GSDMC, and GSDMD). GSDMD (located on chromosome 8q24 and not linked to asthma) has emerged as a key mediator of pyroptosis. GSDMD is a key component of the NLPR3 inflammasome and is required for its activation. GSDMD undergoes proteolytic cleavage by caspase-1 to release its N-terminal fragment, which in turn mediates pyroptosis and IL-1β secretion. Chromosome 17q21 has not only been linked to asthma but also to type 1 diabetes, inflammatory bowel disease, and primary biliary cirrhosis suggesting that future insights into the biology of genes located in this region will increase our understanding of these diseases.

Gene polymorphism linked to increased asthma and IBD risk alters gasdermin-B structure, a sulfatide and phosphoinositide binding protein

The exact function of human gasdermin-B (GSDMB), which regulates differentiation and growth of epithelial cells, is yet to be elucidated. In human epidermal growth factor receptor 2 (HER2)-positive breast cancer, GSDMB gene amplification and protein overexpression indicate a poor response to HER2-targeted therapy. Genome-wide association studies revealed a correlation between GSDMB SNPs and an increased susceptibility to Crohn's disease, ulcerative colitis, and asthma. The N- and C-terminal domains of all gasdermins possess lipid-binding and regulatory activities, respectively. Inflammatory caspases cleave gasdermin-D in the interdomain linker but not GSDMB. The cleaved N-terminal domain binds phosphoinositides and cardiolipin, forms membrane-disrupting pores, and executes pyroptosis. We show that both full-length GSDMB and the N-terminal domain bind to nitrocellulose membranes immobilized with phosphoinositides or sulfatide, but not with cardiolipin. In addition, the GSDMB N-terminal domain binds liposomes containing sulfatide. The crystal structure of the GSDMB C-terminal domain reveals the structural impact of the amino acids encoded by SNPs that are linked to asthma and inflammatory bowel disease (IBD). A loop that carries the polymorphism amino acids corresponding to healthy individuals (Gly299:Pro306) exhibits high conformational flexibility, whereas the loop carrying amino acids found in individuals with increased disease risk (Arg299:Ser306) exhibits a well-defined conformation and higher positive surface charge. Apoptotic executioner caspase-3, -6, and -7, but not the inflammatory caspases, cleave GSDMB at 88DNVD91 within the N-terminal domain. Selective sulfatide binding may indicate possible function for GSDMB in the cellular sulfatide transport.

The role of ORMDL proteins, guardians of cellular sphingolipids, in asthma

A family of widely expressed ORM-like (ORMDL) proteins has been recently linked to asthma in genomewide association studies in humans and extensively explored in in vivo studies in mice. ORMDL proteins are key regulators of serine palmitoyltransferase, an enzyme catalyzing the initial step of sphingolipid biosynthesis. Sphingolipids play prominent roles in cell signaling and response to stress, and they affect the mechanistic properties of cellular membranes. Deregulation of sphingolipid biosynthesis and their recycling has been proven to support and even cause several diseases including allergy, inflammation, and asthma. ORMDL3, the most extensively studied member of the ORMDL family, has been shown to be important for endoplasmic reticulum homeostasis by regulating the unfolded protein response and calcium response. In immune cells, ORMDL3 is involved in migration and in the production of proinflammatory cytokines. Furthermore, changes in the expression level of ORMDL3 are important in allergen-induced asthma pathologies. This review focuses on functional aspects of the ORMDL family proteins, which may serve as new therapeutic targets for the treatment of asthma and some other life-threatening diseases.

Association Between Gasdermin A and Gasdermin B Polymorphisms and Susceptibility to Adult and Childhood Asthma Among Jordanians

INTRODUCTION

Gasdermin A (GSDMA) and gasdermin B (GSDMB) have been associated with childhood, and to a lesser extent with adult, asthma in many populations.

AIMS

In this study, we investigated the association between GSDMA and GSDMB variants and the incidence of adult and childhood asthma among Jordanians.

METHODS

Subjects were divided into two groups: adults and children. Within the adult group there were 129 asthma patients and 111 healthy controls. In the pediatric group there were 98 asthma patients and 112 healthy children. Gasdermin A (GSDMA) (rs7212938, T/G) and Gasdermin B (rs7216389, T/C) polymorphisms were genotyped using the PCR-RFLP method. Three analysis models were applied to the genotype data: co-dominant, dominant and recessive.

RESULTS

An association between the GSDMB T/C single nucleotide polymorphism (SNP) genotype and the incidence of childhood asthma was found (< 0.05). GSDMB T/C SNP in children also showed a very high tendency toward significance with p = 0.0532 in the single locus analysis. In adults, no significant differences in the allelic frequencies of any of the SNPs analyzed were found between the case and control populations. At the haplotype level, GC haplotype was found to be associated with the risk of asthma in children while none of the tested haplotypes were found to be associated with asthma risk in adults.

CONCLUSIONS

The findings of this study confirm the previously reported association between the GSDMB gene and the risk of childhood asthma.

Loss of conserved Gsdma3 self-regulation causes autophagy and cell death

Gasdermin A3 (Gsdma3) was originally identified in association with hair-loss phenotype in mouse mutants. Our previous study found that AE mutant mice, with a Y344H substitution at the C-terminal domain of Gsdma3, display inflammation-dependent alopecia and excoriation [Zhou et al. (2012) Am. J. Pathol. 180, 763-774]. Interestingly, we found that the newly-generated null mutant of Gsdma3 mice did not display the skin dysmorphology, indicating that Gsdma3 is not essential for differentiation of epidermal cells and maintenance of the hair cycle in normal physiological conditions. Consistently, human embryonic kidney (HEK)293 and HaCaT cells transfected with wild-type (WT) Gsdma3 did not show abnormal morphology. However, Gsdma3 Y344H mutation induced autophagy. Gsdma3 N-terminal domain, but not the C-terminal domain, also displayed the similar pro-autophagic activity. The Gsdma3 Y344H mutant protein and N-terminal domain-induced autophagy was associated with mitochondria and ROS generation. Co-expression of C-terminal domain reversed the cell autophagy induced by N-terminal domain. Moreover, C-terminal domain could be co-precipitated with N-terminal domain. These data indicated that the potential pro-autophagic activity of WT Gsdma3 protein is suppressed through an intramolecular inhibition mechanism. Studies on other members of the GSDM family suggested this mechanism is conserved in several sub-families.

IL-18 in inflammatory and autoimmune disease

Inflammation serves as the first line of defense in response to tissue injury, guiding the immune system to ensure preservation of the host. The inflammatory response can be divided into a quick initial phase mediated mainly by innate immune cells including neutrophils and macrophages, followed by a late phase that is dominated by lymphocytes. Early in the new millennium, a key component of the inflammatory reaction was discovered with the identification of a number of cytosolic sensor proteins (Nod-like receptors) that assembled into a common structure, the 'inflammasome'. This structure includes an enzyme, caspase-1, which upon activation cleaves pro-forms of cytokines leading to subsequent release of active IL-1 and IL-18. This review focuses on the role of IL-18 in inflammatory responses with emphasis on autoimmune diseases.

The non-obese diabetic mouse sequence, annotation and variation resource: an aid for investigating type 1 diabetes

Model organisms are becoming increasingly important for the study of complex diseases such as type 1 diabetes (T1D). The non-obese diabetic (NOD) mouse is an experimental model for T1D having been bred to develop the disease spontaneously in a process that is similar to humans. Genetic analysis of the NOD mouse has identified around 50 disease loci, which have the nomenclature Idd for insulin-dependent diabetes, distributed across at least 11 different chromosomes. In total, 21 Idd regions across 6 chromosomes, that are major contributors to T1D susceptibility or resistance, were selected for finished sequencing and annotation at the Wellcome Trust Sanger Institute. Here we describe the generation of 40.4 mega base-pairs of finished sequence from 289 bacterial artificial chromosomes for the NOD mouse. Manual annotation has identified 738 genes in the diabetes sensitive NOD mouse and 765 genes in homologous regions of the diabetes resistant C57BL/6J reference mouse across 19 candidate Idd regions. This has allowed us to call variation consequences between homologous exonic sequences for all annotated regions in the two mouse strains. We demonstrate the importance of this resource further by illustrating the technical difficulties that regions of inter-strain structural variation between the NOD mouse and the C57BL/6J reference mouse can cause for current next generation sequencing and assembly techniques. Furthermore, we have established that the variation rate in the Idd regions is 2.3 times higher than the mean found for the whole genome assembly for the NOD/ShiLtJ genome, which we suggest reflects the fact that positive selection for functional variation in immune genes is beneficial in regard to host defence. In summary, we provide an important resource, which aids the analysis of potential causative genes involved in T1D susceptibility.

Database URLs:http://www.sanger.ac.uk/resources/mouse/nod/; http://vega-previous.sanger.ac.uk/info/data/mouse_regions.html

Promoter characterization and role of cAMP/PKA/CREB in the basal transcription of the mouse ORMDL3 gene

Orosomucoid 1-like 3 (ORMDL3) gene was strongly linked with the development of asthma in genetic association studies, and its expression could be significantly induced by allergen in airway epithelial cells of mice. However, the expression mechanism of ORMDL3 was still unclear. Here we have identified and characterized the mouse ORMDL3 gene promoter. Deletion constructs of the 5' flanking region were fused to a luciferase reporter gene. After transient transfection in mouse fibroblast cell line NIH3T3, a CRE (-27/-20) binding CREB was identified in the core promoter region. Deletion or mutation of the CRE consensus sequence resulted in a significant loss of the promoter activity. EMSA and ChIP assays demonstrated the binding of CREB to the core promoter. Knocking down endogenous CREB led to a reduction in ORMDL3 expression. Conversely, overexpression of CREB up-regulated ORMDL3 expression. Moreover, forskolin, a PKA activator, could facilitate the phosphorylation of CREB, which in turn heightens ORMDL3 expression. H-89, a PKA-specific inhibitor, could significantly inhibit ORMDL3 expression. This study delineates the characterization of mouse ORMDL3 gene promoter and shows signaling pathway cAMP/PKA/CREB plays an important role in regulating ORMDL3 expression, which will be helpful for future animal model studies regarding the regulation or function of ORMDL3 gene.

Signal transducer and activator of transcription 6 directly regulates human ORMDL3 expression

Orosomucoid-like 3 (ORMDL3) has been associated with asthma and a series of autoimmune disorders, and is involved in endoplasmic reticulum-mediated inflammatory responses. However, its clinical significance and the molecular mechanism underlying its expression are still largely unclear. To elucidate the mechanisms of human ORMDL3 transcriptional regulation, we cloned a 1.5 kb genomic DNA fragment containing the putative promoter region and evaluated its transcriptional activity in a luciferase reporter system by deletion analysis. We identified a 68 bp region that functions as a minimal promoter. Bioinformatics analysis predicted that the -64 to -56 bp region contained a signal transducer and activator of transcription 6 (STAT6) binding site. Electrophoretic mobility shift assay and chromatin immunoprecipitation demonstrated that STAT6 bound to its binding site within the ORMDL3 promoter. STAT6 over-expression or knockdown trans-activated or trans-inhibited, respectively, the ORMDL3 promoter containing the STAT6-binding motif. Treatment with interleukins 4 or 13 increased ORMDL3 promoter activity as well as endogenous ORMDL3 expression. Immunoprecipitation and ChIP/Re-ChIP assays revealed that STAT6 and p300 exist in the same protein complex that binds to the ORMDL3 promoter. Our study confirmed that STAT6 plays important roles in regulating the expression of human ORMDL3 by directly binding to the promoter region, which may shed light on a possible role in various human diseases.

Functional analysis of the impact of ORMDL3 expression on inflammation and activation of the unfolded protein response in human airway epithelial cells

Background

The gene ORMDL3 was shown to be associated with early-onset asthma susceptibility in multiple independent genome-wide and candidate-gene association studies. Asthmatic patients have elevated expression levels of this gene. ORMDL3 encodes a transmembrane protein localized in the endoplasmic reticulum (ER) that may be involved in ER stress and inflammation. It is essential to validate the genetic associations linking ORMDL3 with asthma through functional studies that confirm the biological relevance of this gene in disease. We investigated the effects of manipulating ORMDL3 expression levels in vitro in airway cells on innate immune inflammatory responses, ER stress and activation of the unfolded protein response (UPR).

Methods

ORMDL3 expression levels were manipulated in airway cells using an overexpression plasmid and siRNA technologies. Successful modulation of ORMDL3 was confirmed at both the gene and protein level. The functional impact of modulation of ORMDL3 expression levels on inflammatory responses and activation of the UPR were quantified using complementary cellular and molecular immunology techniques.

Results

Cells with altered ORMDL3 levels responded equally well to innate immune stimuli and produced similar levels of pro-inflammatory cytokines compared to wild-type cells. Treatment with ER stress inducers, thapsigargin and tunicamycin, resulted in activation of the unfolded protein response (UPR). However, we observed no difference in UPR activation in cells with ORMDL3 knockdown compared to cells with normal ORMDL3 levels.

Conclusions

Our results suggest that ORMDL3 variation in the airway epithelium is unlikely to play a significant role in modulating innate immune responses and the UPR in the lung.

Mechanisms elevating ORMDL3 expression in recurrent wheeze patients: role of Ets-1, p300 and CREB

The first genetic factor identified for childhood asthma by genome-wide association study (GWAS) is the locus on chromosome 17q21, harboring the Orosomucoid 1-like 3 (ORMDL3) gene. ORMDL3 is implicated in facilitation of endoplasmic reticulum-mediated inflammatory responses, believed to underlie its association with asthma. In the present study, we demonstrated that mRNA expression of ORMDL3 is significantly increased in the peripheral blood of recurrent wheeze patients compared with normal control subjects by real-time RT-PCR. To elucidate the molecular mechanisms involved in human ORMDL3 regulation, we cloned and characterized the promoter region of ORMDL3. Applying 5'-rapid amplification of cDNA end analysis (RACE), we revealed that ORMDL3 gene used multiple transcriptional start sites (TSSs). Using a series of 5' deletion promoter plasmids in luciferase reporter assays, we identified that the proximal minimal promoter of ORMDL3 was located within the region -84/+58 relative to the TSS. Mutational analysis, RNA interference experiments and sequential chromatin immunoprecipitation (ChIP) assay demonstrated that transcriptional activity of the ORMDL3 gene was cooperatively regulated by multiple transcription factors, including Ets-1, p300 and CREB. The expression levels of Ets-1, p300 and CREB were increased in the peripheral blood of recurrent wheeze patients compared with normal control subjects and showed a strong linear correlation with the expression of ORMDL3. Our findings indicate that Ets-1, p300 and CREB binding to the promoter region drive the ORMDL3 transcription.