Genome-wide analyses in Lyme borreliosis: identification of a genetic variant associated with disease susceptibility and its immunological implications.

BACKGROUND: Genetic variation underly inter-individual variation in host immune responses to infectious diseases, and may affect susceptibility or the course of signs and symptoms. METHODS: We performed genome-wide association studies in a prospective cohort of 1138 patients with physician-confirmed Lyme borreliosis (LB), the most common tick-borne disease in the Northern hemisphere caused by the bacterium Borrelia burgdorferi sensu lato. Genome-wide variants in LB patients-divided into a discovery and validation cohort-were compared to two healthy cohorts. Additionally, ex vivo monocyte-derived cytokine responses of peripheral blood mononuclear cells to several stimuli including Borrelia burgdorferi were performed in both LB patient and healthy control samples, as were stimulation experiments using mechanistic/mammalian target of rapamycin (mTOR) inhibitors. In addition, for LB patients, anti-Borrelia antibody responses were measured. Finally, in a subset of LB patients, gene expression was analysed using RNA-sequencing data from the ex vivo stimulation experiments. RESULTS: We identified a previously unknown genetic variant, rs1061632, that was associated with enhanced LB susceptibility. This polymorphism was an eQTL for KCTD20 and ETV7 genes, and its major risk allele was associated with upregulation of the mTOR pathway and cytokine responses, and lower anti-Borrelia antibody production. In addition, we replicated the recently reported SCGB1D2 locus that was suggested to have a protective effect on B. burgdorferi infection, and associated this locus with higher Borrelia burgdorferi antibody indexes and lower IL-10 responses. CONCLUSIONS: Susceptibility for LB was associated with higher anti-inflammatory responses and reduced anti-Borrelia antibody production, which in turn may negatively impact bacterial clearance. These findings provide important insights into the immunogenetic susceptibility for LB and may guide future studies on development of preventive or therapeutic measures. TRIAL REGISTRATION: The LymeProspect study was registered with the International Clinical Trials Registry Platform (NTR4998, registration date 2015-02-13).

Secretoglobin 3A2 protects lung from developing cigarette smoke-induced pulmonary emphysema.

Secretoglobin (SCGB) 3A2 is a bioactive molecule exhibiting various functions such as improving allergic airway inflammation and pulmonary fibrosis and promoting bronchial branching and proliferation during lung development. To determine if and how SCGB3A2 is involved in chronic obstructive pulmonary disease (COPD), a multifactorial disease with both airway and emphysematous lesions, a COPD mouse model was created by exposing Scgb3a2-deficient (KO), Scgb3a2-lung-specific overexpressing (TG), and wild type (WT) mice to cigarette smoke (CS) for 6 months. The KO mice showed loss of lung structure under control condition, and CS exposure resulted in more expansion of airspace and destruction of alveolar wall than WT mouse lungs. In contrast, TG mouse lungs showed no significant changes after CS exposure. SCGB3A2 increased the expression and phosphorylation of signal transducers and activators of transcription (STAT)1 and STAT3, and the expression of α1-antitrypsin (A1AT) in mouse lung fibroblast-derived MLg cells and mouse lung epithelial-derived MLE-15 cells. In MLg cells, A1AT expression was decreased in Stat3-knockdown cells, and increased upon Stat3 overexpression. STAT3 formed a homodimer when cells were stimulated with SCGB3A2. Chromatin immunoprecipitation and reporter assays demonstrated that STAT3 binds to specific binding sites on the Serpina1a gene encoding A1AT and upregulates its transcription in lung tissues of mice. Furthermore, nuclear localization of phosphorylated STAT3 upon SCGB3A2 stimulation was detected by immunocytochemistry. These findings demonstrate that SCGB3A2 protects the lungs from the development of CS-induced emphysema by regulating A1AT expression through STAT3 signaling.

Development of Aging-Related Emphysematous and Lymphoma-Like Lesions is Enhanced by the Lack of Secretoglobin 3A2 in Mouse Lungs.

Background: Secretoglobin (SCGB) 3A2 is a novel bioactive molecule with anti-inflammatory and anti-fibrotic activities. SCGB3A2 also promotes the maturation of bronchial divergence and the lungs during embryonic development. However, much remains unknown concerning the roles of SCGB3A2 in diseases associated with aging. Methods: The lungs of Scgb3a2-knockout (KO) mice and their wild-type (WT) littermates were subjected to histological analysis, Victoria blue staining to evaluate of elastic fibers, and lung morphometric analysis during the postnatal period (birth to 8 weeks) and during aging (8 weeks to 2 years). Their spleens were also histologically evaluated. The expression of lung surfactant protein (SP) mRNAs was examined by quantitative reverse transcriptase-polymerase chain reaction. RNA sequencing (RNAseq) analysis was performed on 3-month-old KO and WT mouse lungs. Results: The alveolar spaces of KO mice continuously expanded between 0.5 and 2 years of age, accompanied by increases of the mean linear intercept and destructive index. KO mouse lungs displayed inflammation associated with lymphocyte aggregate starting at 1 year of age, and the inflammation was worse than that of WT mouse lungs. A high number of lymphoma-like cells were presented in 2-year-old KO mouse lungs. White pulp fusion was detected in the spleens of both WT and KO mice older than 0.5 years; however, the fusion was more severe in KO mice than in WT mice. The expression of surfactant protein (SP)-A, SP-B, SP-C, and SP-D mRNAs in KO mouse lungs decreased with age, and after 1 year of age, the expression of most SPs was significantly lower in KO mice than in WT mice. RNAseq demonstrated that the expression of immune system-related genes was highly altered in KO mouse lungs. Conclusion: SCGB3A2 may be required for maintaining homeostasis and immune activity in the lungs during aging. SCGB3A2 deficiency might increase the risk of emphysema of the lung.

Emerging role of an immunomodulatory protein secretoglobin 3A2 in human diseases.

Secretoglobin (SCGB) 3A2 was first identified in 2001 as a protein exhibiting similarities in amino acid sequence and gene structure to SCGB1A1, a multi-functional cytokine-like molecule highly expressed in airway epithelial Club cells that was the first identified and extensively studied member of the SCGB gene superfamily. SCGB3A2 is a small secretory protein of ~10 kDa that forms a dimer and a tetramer. SCGB3A2 is predominantly expressed in airway epithelial Club cells, and has anti-inflammatory, growth factor, anti-fibrotic, and anti-cancer activities that influence various lung diseases. This review summarizes the current understanding of SCGB3A2 biological functions and its role in human diseases with emphasis on its mechanisms of actions and signaling pathway.

Dysregulation of club cell biology in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic fibrotic lung disease with an irreversible decline of lung function. "Bronchiolization", characterized by ectopic appearance of airway epithelial cells in the alveolar regions, is one of the characteristic features in the IPF lung. Based on the knowledge that club cells are the major epithelial secretory cells in human small airways, and their major secretory product uteroglobin (SCGB1A1) is significantly increased in both serum and epithelial lining fluid of IPF lung, we hypothesize that human airway club cells contribute to the pathogenesis of IPF. By assessing the transcriptomes of the single cells from human lung of control donors and IPF patients, we identified two SCGB1A1+ club cell subpopulations, highly expressing MUC5B, a significant genetic risk factor strongly associated with IPF, and SCGB3A2, a marker heterogeneously expressed in the club cells, respectively. Interestingly, the cellular proportion of SCGB1A1+MUC5B+ club cells was significantly increased in IPF patients, and this club cell subpopulation highly expressed genes related to mucous production and immune cell chemotaxis. In contrast, though the cellular proportion did not change, the molecular phenotype of the SCGB1A1+SCGB3A2high club cell subpopulation was significantly altered in IPF lung, with increased expression of mucins, cytokine and extracellular matrix genes. The single cell transcriptomic analysis reveals the cellular and molecular heterogeneity of club cells, and provide novel insights into the biological functions of club cells in the pathogenesis of IPF.

Selection of a Noninvasive Source of Human DNA Envisaging Genotyping Assays in Epidemiological Studies: Urine or Saliva?

Genetic epidemiology requires an appropriate approach to measure genetic variation within the population. The aim of this study was to evaluate the characteristics and genotyping results of DNA extracted from 2 human DNA sources, selected for their rapid and noninvasive sampling, and the use of simple and standardized protocols that are essential for large-scale epidemiologic studies. Saliva and urine samples were collected at the same day from 20 subjects aged 9-10 yr. Genomic DNA was extracted using commercial kits. Quantitative and qualitative evaluation was done by assessing the yield, the purity, and integrity of the extracted DNA. As a proof-of-concept, genotyping was performed targeting CC16 A38G and uteroglobin-related protein 1 (UGRP1)-112G/A. Saliva was found to provide the highest yield and concentration of total DNA extracted. Salivary DNA showed higher purity and a significantly less degraded state compared to urinary DNA. Consequently, the salivary DNA gave better genotyping results than urinary DNA. Therefore, if the choice exists, saliva is the preferred noninvasive matrix for genotyping purposes in large-scale genetic epidemiologic studies. Only in particular cases using urine could nevertheless be considered useful, although specific limitations need to be taken into account.

Uterus globulin associated protein 1 (UGRP1) is a potential marker of progression of Graves' disease into hypothyroidism.

Approximately 20% of Graves' disease (GD) patients may result eventually in hypothyroidism in their natural course. Uterus globulin-associated protein 1 (UGRP1) was associated with GD in our previous study. Here we investigated the role of UGRP1 in the development of autoimmune thyroid disease (AITD). The results showed that UGRP1 was expressed in the thyrocytes of most Hashimoto's thyroiditis (HT) patients and a proportion of GD patients (293 HT and 198 GD). The pathologic features of UGRP1-positive thyrocytes resembled "Hürthle cells", and were surrounded by infiltrated leukocytes. The positivity rate of TPOAb in UGRP1-positive GD patients was much higher than that in -negative GD patients. Moreover, UGRP1 was co-expressed with Fas and HLA-DR in the thyrocytes of AITD patients. We also found IL-1ß but not Th1 or Th2 cytokines was able to upregulate the expression of UGRP1. Our findings indicated that UGRP1 may be a novel marker in thyrocytes to predict GD patients who develop hypothyroidism.

Spatiotemporal Expression of Three Secretoglobin Proteins, SCGB1A1, SCGB3A1, and SCGB3A2, in Mouse Airway Epithelia.

Secretoglobins (SCGBs) are cytokine-like small molecular weight secreted proteins with largely unknown biological functions. Three SCGB proteins, SCGB1A1, SCGB3A1, and SCGB3A2, are predominantly expressed in lung airways. To gain insight into the possible functional relationships among the SCGBs, their protein and mRNA expression patterns were examined in lungs during gestation and in adult mice, using Scgb3a1-null and Scgb3a2-null mice as negative controls, by immunohistochemistry and by qRT-PCR analysis, respectively. The three SCGBs exhibited unique spatiotemporal expression patterns during embryogenesis. The lack of Scgb3a1 or Scgb3a2 did not affect expression of the other Scgb genes as determined by mRNA measurements. Moreover, the lack of Scgb3a1 or Scgb3a2 did not affect development of the pulmonary neuroepithelial bodies during embryogenesis, while the lack of Scgb3a2 may have resulted in slightly fewer ciliated cells than in the wild-type. These results suggest that SCGB1A1, SCGB3A1, and SCGB3A2 each may possess its own unique biological function.

A novel pathway of LPS uptake through syndecan-1 leading to pyroptotic cell death.

Intracellular lipopolysaccharide (LPS) triggers the non-canonical inflammasome pathway, resulting in pyroptosis of innate immune cells. In addition to its well-known proinflammatory role, LPS can directly cause regression of some tumors, although the underlying mechanism has remained unknown. Here we show that secretoglobin(SCGB)3A2, a small protein predominantly secreted in airways, chaperones LPS to the cytosol through the cell surface receptor syndecan-1; this leads to pyroptotic cell death driven by caspase-11. SCGB3A2 and LPS co-treatment significantly induced pyroptosis of macrophage RAW264.7 cells and decreased cancer cell proliferation in vitro, while SCGB3A2 treatment resulted in reduced progression of xenograft tumors in mice. These data suggest a conserved function for SCGB3A2 in the innate immune system and cancer cells. These findings demonstrate a critical role for SCGB3A2 as an LPS delivery vehicle; they reveal one mechanism whereby LPS enters innate immune cells leading to pyroptosis, and they clarify the direct effect of LPS on cancer cells.

Differentially expressed Secretoglobin 1C1 gene in nasal polyposis.

Nasal polyps (NP) are the most common pathological change that occurs in the nasal mucosa and is characterized by mucosal inflammation. Although its etiology and pathogenesis have not been clearly explained, its pathophysiology is arranged by the balance between pro-inflammatory and anti-inflammatory cytokines. The Secretoglobin 1C1 gene synthesizes odor molecule binding proteins (OBPs) in the nasal mucosa and regulates some cytokines. The Secretoglobin 1C1 gene expression could be disrupted by polymorphisms that may act as a possible cause of a disruption in the regulation of the promotor of the gene. Therefore, the main aim of this study was to determine the effects of Secretoglobin 1C1 gene promotor polymorphisms on the gene expression in NP.  In this study, to determine the relationship between the Secretoglobin 1C1 gene promotor polymorphisms and the gene expression, the levels of 48 subjects were sequenced (24 patients with NP and 22 controls without sinonasal disease). The levels' expression of Secretoglobin 1C1 in the subjects' nasal mucosa was also detected using RT-PCR.  In this study, the level of Secretoglobin 1C1's expression increased in NP (P= 0.003). Three polymorphisms were detected in the Secretoglobin 1C1 gene's promotor. The rs113795008 and rs2280540 variations were significantly high in NP (P= 0.005, P= 0.045). The the rs113795008 homozygous mutant type genotype (G/G) was associated with a high mRNA expression level of Secretoglobin 1C1 in NP (P= 0.009). A correlation was found between a high level of Secretoglobin 1C1 expression and its promotor polymorphism, which thus might increase and/or contribute to the susceptibility of developing NP in the Turkish population. These findings suggested that promotor variations in the function of the Secretoglobin 1C1 gene can alter the gene expression biology in NP.

Association Between Secretoglobin Family 3A Member 2 (SCGB3A2) Gene Polymorphisms and Asthma in a Korean Population.

BACKGROUND Secretoglobin family 3A member 2 (SCGB3A2) plays an important role in secreting lung surfactant protein, which is a downstream target of thyroid transcription factor. MATERIAL AND METHODS We investigated whether single-nucleotide polymorphisms (SNPs) of SCGB3A2 gene contribute to susceptibility to asthma. To explore this possible association, 2 promoter SNPs (rs6882292, 659 G/A and rs1368408, -112 G/A) and missense SNP (rs151333009, stop codon) were tested in SCGB3A2 gene in 101 asthma patients and 377 healthy control subjects. SNPStats was used to obtain odds ratio (OR), 95% confidence intervals (CI), and P value adjusted for age and sex as covariables. Logistic regression method in each model (dominant, recessive, and log-additive) was applied to analyze genetic data. RESULTS rs151333009 SNP showed a monomorphic genotype. Two promoter SNPs (rs6882292, -659 G/A and rs1368408, -112 G/A) showed significant association with asthma (rs6882292, OR=2.66, 95% CI=1.42-5.01, p=0.0033 in dominant model, OR=2.45, 95% CI=1.33-4.54, p=0.0055 in log-additive model; rs1368408, OR=1.59, 95% CI=1.02-2.49, p=0.041 in dominant model, OR=3.02, 95% CI=1.15-7.90, p=0.03 in recessive model, OR=1.63, 95% CI=1.63, 95% CI=1.12-2.37, p=0.012 in log-additive model). CONCLUSIONS These results suggest that the promoter SNPs (rs6882292 and rs1368408) of SCGB3A2 gene may contribute to susceptibility to asthma in a Korean population.

Significant association between SCGB1D4 gene polymorphisms and susceptibility to adenoid hypertrophy in a pediatric population.

BACKGROUND/AIM: Adenoid hypertrophy (AH) is chronic enlargement of the adenoid tissue. The pathophysiology of the disease is unclear. We analyzed SCGB1D4 gene polymorphisms in order to determine the effect of the variants or their genetic combinations on AH. MATERIALS AND METHODS: We genotyped the SCGB1D4 (IIS) gene in 167 participants (95 children with AH and 72 controls) by performing DNA sequencing in blood samples. RESULTS: We genotyped three single nucleotide polymorphisms (SNPs). In the analysis, we found that in the presence of those SNPs and the minor alleles of individual SNPs four haplotypes were associated with an increased risk of AH. In addition, those SNPs were significantly associated with asthma, allergy, sleep-disordered breathing, AH grade +4, and a high level of IgE. As indicated on multifactor dimensionality reduction analysis, single-locus (rs35328961), two-locus (rs35328961_rs56196602), and three-locus models (rs200327820_rs35328961_rs56196602) had the highest synergistic interaction effect on AH. The three-factor model was also significantly associated with some genotypes of rs35328961 and allergic-asthmatic AH. CONCLUSION: SNPs of SCGB1D4 and their combinations are associated with an increased risk for developing AH. We highlighted the importance of genetic factors on AH and AH-related clinical phenotypes.

Secretoglobin Superfamily Protein SCGB3A2 Alleviates House Dust Mite-Induced Allergic Airway Inflammation in Mice.

BACKGROUND: Secretoglobin (SCGB) 3A2, a novel, lung-enriched, cytokine-like, secreted protein of small molecular weight, was demonstrated to exhibit various biological functions including anti-inflammatory, antifibrotic and growth-factor activities. Anti-inflammatory activity was uncovered using the ovalbumin-induced allergic airway inflammation model. However, further validation of this activity using knockout mice in a different allergic inflammation model is necessary in order to establish the antiallergic inflammatory role for this protein. METHODS: Scgb3a2-null (Scgb3a2-/-) mice were subjected to nasal inhalation of Dermatophagoides pteronyssinus extract for 5 days/week for 5 consecutive weeks; control mice received nasal inhalation of saline as a comparator. Airway inflammation was assessed by histological analysis, the number of inflammatory cells and various Th2-type cytokine levels in the lungs and bronchoalveolar lavage fluids by qRT-PCR and ELISA, respectively. RESULTS: Exacerbated inflammation was found in the airway of Scgb3a2-/- mice subjected to house dust mite (HDM)-induced allergic airway inflammation compared with saline-treated control groups. All the inflammation end points were increased in the Scgb3a2-/- mice. The Ccr4 and Ccl17 mRNA levels were higher in HDM-treated lungs of Scgb3a2-/- mice than wild-type mice or saline-treated Scgb3a2-/- mice, whereas no changes were observed for Ccr3 and Ccl11 mRNA levels. CONCLUSIONS: These results demonstrate that SCGB3A2 has an anti-inflammatory activity in the HDM-induced allergic airway inflammation model, in which SCGB3A2 may modulate the CCR4-CCL17 pathway. SCGB3A2 may provide a useful tool to treat allergic airway inflammation, and further studies on the levels and function of SCGB3A2 in asthmatic patients are warranted.

Breast cancer gene therapy using an adenovirus encoding human IL-2 under control of mammaglobin promoter/enhancer sequences.

Interleukin-2 (IL-2) has been used clinically for the treatment of some malignancies, but the toxicities associated with systemic IL-2 therapy are a major challenge. Here we have determined whether transcriptional targeting of IL-2 to breast cancer (BrCa) using an engineered human mammaglobin promoter/enhancer (MPE2) is a feasible option for reducing IL-2-associated toxicities while still achieving a meaningful antitumor effect. We have constructed nonreplicating adenovirus vectors encoding either a reporter gene (luciferase) or human IL-2 (hIL-2) complementary DNA under control of the MPE2 sequence, the murine cytomegalovirus immediate early (MCMV) promoter or the human telomerase reverse transcriptase (hTERT) promoter. Luciferase and hIL-2 complementary DNAs under the control of the MPE2 sequence in adenovirus vectors were expressed at high levels in BrCa cells and at lower levels in normal cells of human and murine origin. Cancer specificity of the hTERT promoter was found to be similar to that of the MPE2 promoter in cells of human origin, but reduced specificity in murine cells. The MPE2 regulatory sequence demonstrated excellent tissue specificity in a mouse tumor model. Whereas the MCMV promoter-controlled IL-2 vector generated high liver toxicity in mice, the MPE2-controlled IL-2 vector generated little or no liver toxicity. Both IL-2 vectors exerted significant tumor growth delay; however, attempts to further enhance antitumor activity of the IL-2 vectors by combining with the proapoptotic drug procaspase activating compound 1 (PAC1) were unsuccessful.

An exceptionally long CA-repeat in the core promoter of SCGB2B2 links with the evolution of apes and Old World monkeys.

We have recently reported a genome-scale catalog of human protein-coding genes that contain "exceptionally long" STRs (≥6-repeats) in their core promoter, which may be of selective advantage in this species. At the top of that list, SCGB2B2 (also known as SCGBL), contains one of the longest CA-repeat STRs identified in a human gene core promoter, at 25-repeats. In the study reported here, we analyzed the conservation status of this CA-STR across evolution. The functional implication of this STR to alter gene expression activity was also analyzed in the HEK-293 cell line. We report that the SCGB2B2 core promoter CA-repeat reaches exceptional lengths, ranging from 9- to 25-repeats, across Apes (Hominoids) and the Old World monkeys (CA>2-repeats were not detected in any other species). The longest CA-repeats and highest identity in the SCGB2B2 protein sequence were observed between human and bonobo. A trend for increased gene expression activity was observed from the shorter to the longer CA-repeats (p<0.009), and the CA-repeat increased gene expression activity, per se (p<0.02). We propose that the SCGB2B2 gene core promoter CA-repeat functions as an expression code for the evolution of Apes and the Old World monkeys.

Secretoglobin 3A2 Exhibits Anti-Fibrotic Activity in Bleomycin-Induced Pulmonary Fibrosis Model Mice.

OBJECTIVE: Secretoglobin (SCGB) 3A2 is a novel lung-enriched cytokine, previously shown to exhibit anti-inflammatory, growth factor, and anti-fibrotic activities. The latter activity was demonstrated using exogenously-administered recombinant SCGB3A2 in the bleomycin (BLM)-induced pulmonary fibrosis model. Whether SCGB3A2 exhibits anti-fibrotic activity in vivo is not known. METHODS: Mice null for the Scgb3a2 gene were subjected to the BLM-induced pulmonary fibrosis model, and the severity of pulmonary fibrosis determined using histological and biochemical methods. RESULTS: BLM treatment caused weight loss of both Scgb3a2-null and wild-type mice, however, the loss was far more pronounced in BLM-treated Scgb3a2-null than wild-type mice, and the weight of day 21 of BLM-treated Scgb3a2-null mice was about half of that of BLM-treated wild-type mice. Hematoxylin & Eosin, Masson Trichrome, and Sirius Red staining of lung sections, Ashcroft fibrosis scores, hydroxyproline contents, and the levels of mRNAs encoding various collagens demonstrated that BLM-treated Scgb3a2-null mouse lungs had more severe fibrosis than those of wild-type mouse lungs. Total and differential inflammatory cell numbers in bronchoalveolar lavage fluids, and levels of lung mRNAs including those encoding Th2 cytokines such as IL-4 and profibrotic cytokines such as TGFß were higher in BLM-treated Scgb3a2-null mouse lungs as compared to those of wild-type mouse lungs. In contrast, mRNAs encoding surfactant proteins A, B, C, and D, and SCGB1A1 did not differ between BLM-treated Scgb3a2-null and wild-type mouse lungs. CONCLUSION: The role of SCGB3A2 in fibrosis was revisited using Scgb3a2-null mice and littermate controls in the BLM-induced pulmonary fibrosis model. The pulmonary fibrosis in the Scgb3a2-null mice was more severe than the wild-type controls, thus establishing that SCGB3A2 has anti-fibrotic activity in vivo. Importantly, surfactant proteins and SCGB1A1 appear not to be involved in the susceptibility of Scgb3a2-null mice to BLM-induced pulmonary fibrosis.

Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease.

BACKGROUND: Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls. HYPOTHESIS/OBJECTIVES: Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD). ANIMALS: Recurrent airway obstruction-affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client-owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited. METHODS: Pulmonary function and BALF were evaluated from control and RAO-affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client-owned horses (RAO-affected horses, n = 17; IAD-affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots. RESULTS: Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO-affected horses than in IAD-affected and control horses. CONCLUSIONS AND CLINICAL IMPORTANCE: Secretoglobin and transferrin expression is decreased in BALF of RAO-affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease.

Transgenically-expressed secretoglobin 3A2 accelerates resolution of bleomycin-induced pulmonary fibrosis in mice.

BACKGROUND: Secretoglobin (SCGB) 3A2, a cytokine-like secretory protein of small molecular weight, is predominantly expressed in airway epithelial cells. While SCGB3A2 is known to have anti-inflammatory, growth factor, and anti-fibrotic activities, whether SCGB3A2 has any other roles, particularly in lung homeostasis and disease has not been demonstrated in vivo. The aim of this study was to address these questions in mice. METHODS: A transgenic mouse line that expresses SCGB3A2 in the lung using the human surfactant protein-C promoter was established. Detailed histological, immunohistochemical, physiological, and molecular characterization of the Scgb3a2-transgenic mouse lungs were carried out. Scgb3a2-transgenic and wild-type mice were subjected to bleomycin-induced pulmonary fibrosis model, and their lungs and bronchoalveolar lavage fluids were collected at various time points during 9 weeks post-bleomycin treatment for further analysis. RESULTS: Adult Scgb3a2-transgenic mouse lungs expressed approximately five-fold higher levels of SCGB3A2 protein in comparison to wild-type mice as determined by western blotting of lung tissues. Immunohistochemistry showed that expression was localized to alveolar type II cells in addition to airway epithelial cells, thus accurately reflecting the site of surfactant protein-C expression. Scgb3a2-transgenic mice showed normal lung development and histology, and no overt gross phenotypes. However, when subjected to a bleomycin-induced pulmonary fibrosis model, they initially exhibited exacerbated fibrosis at 3 weeks post-bleomycin administration that was more rapidly resolved by 6 weeks as compared with wild-type mice, as determined by lung histology, Masson Trichrome staining and hydroxyproline content, inflammatory cell numbers, expression of collagen genes, and proinflammatory cytokine levels. The decrease of fibrosis coincided with the increased expression of SCGB3A2 in Scgb3a2-transgenic lungs. CONCLUSIONS: These results demonstrate that SCGB3A2 is an anti-fibrotic agent, and suggest a possible therapeutic use of recombinant SCGB3A2 in the treatment of pulmonary fibrosis.

Single-Nucleotide Polymorphisms on the RYD5 Gene in Nasal Polyposis.

Nasal polyposis (NP) is a chronic inflammatory disease. Several genes play major roles in the pathophysiology of the disease. We analyzed RYD5 gene polymorphisms to determine the effect of these variants or their genetic combinations on NP. We genotyped the RYD5 gene in 434 participants (196 patients with NP and 238 controls). Data were analyzed with SPSS, SNPStats, and multifactor dimensionality reduction (MDR) software. We genotyped 10 single-nucleotide polymorphisms (SNPs) in the RYD5 gene. RYD5 (+152G>T) (p.Gly51Va) has not been reported previously. The PolyPhen and PROVEAN predicted the missense mutation as deleterious, but sorting intolerant from tolerant (SIFT) did not. In the genotype analysis, we found that four SNPs (RYD5 [-264A>G], [-103G>A], [+57-14C>T], and [+66A>G]) were significantly associated with NP. The individuals with combined genotypes of six risk alleles (RYD5-264G, -103A, +13C, +57-14T, +66G, and +279T) had significantly higher risks for NP compared with the ones with one or four risk alleles. Haplotype analysis revealed that the two haplotypes were associated with risk of NP. As indicated by MDR analysis, RYD5 (-264A>G and -103G>A) and RYD5 (-264A>G, -177C>A, and -103G>A) were the best predictive combinations and they had the highest synergistic interaction on NP. In addition, RYD5 (+13C>T) was significantly associated with increased risk of both NP with asthma and NP with allergy and asthma. Some SNPs and their combinations in the RYD5 gene are associated with increased probability for developing NP. We emphasize the importance of genetic factors on NP and NP-related clinical phenotypes.

Gene expression abnormalities in histologically normal breast epithelium from patients with luminal type of breast cancer.

The gene expression profile of breast cancer has been described as a great breakthrough on the way to comprehend differences in cancer origin, behavior and therapy. However, gene expression profile in histologically normal epithelium (HNEpi) which could harbor genetic abnormalities predisposing breast tissue to develop malignancy was minor scope for scientists in the past. Thus, we aimed to analyze gene expressions in HNEpi and breast cancer tissue (BCTis) in order to establish its value as potential diagnostic marker for cancer development. We evaluated a panel of disease-specific genes in luminal type (A/B) of breast cancer and tumor surrounding HNEpi by qRT-PCR Array in 32 microdissected samples. There was 20.2 and 2.4% deregulation rate in genes with at least 2-fold or 5-fold over-expression between luminal (A/B) type breast carcinomas and tumor surrounding HNEpi, respectively. The high-grade luminal carcinomas showed higher number of deregulated genes compared to low-grade cases (50.6 vs. 23.8% with at least 2-fold deregulation rate). The main overexpressed genes in HNEpi were KLK5, SCGB1D2, GSN, EGFR and NGFR. The significant differences in gene expression between BCTis and HNEpi samples were revealed for BAG1, C3, CCNA2, CD44, FGF1, FOSL1, ID2, IL6R, NGFB, NGFR, PAPPA, PLAU, SERPINB5, THBS1 and TP53 gene (p < 0.05) and BCL2L2, CTSB, ITGB4, JUN, KIT, KLF5, SCGB1D2, SCGB2A1, SERPINE1 (p < 0.01), and EGFR, GABRP, GSN, MAP2K7 and THBS2 (p < 0.001), and GSN, KLK5 (p < 0.0001). The ontological gene analyses revealed high deregulations in gene group directly associated with breast cancer prognosis and origin.