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.

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.

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.

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.

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.

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.

Fine-needle aspiration cytology of mammary analog secretory carcinoma masquerading as low-grade mucoepidermoid carcinoma: case report with a review of the literature.

BACKGROUND/AIM: The primary role of fine-needle aspiration cytology (FNAC) of salivary gland masses is to determine the underlying process and guide further management. The objective of our study is to provide a comprehensive review of cytologic features and ancillary studies of mammary analog secretory carcinoma (MASC), discuss differential diagnosis and review recent advances in the understanding of its biologic behavior. CASE: A 23-year-old female underwent ultrasound-guided FNA of a slowly enlarging parotid mass. Smears displayed branching clusters of bland vacuolated polygonal cells in a secretory proteinaceous background. Eosinophilic cells with eccentric nuclei and inconspicuous nucleoli were also noted. Based on positive intracellular mucin staining and the lack of extracellular-matrix material, the cytologic diagnosis rendered was 'suspicious for low grade mucoepidermoid carcinoma'. Superficial parotidectomy revealed an MASC confirmed by fluorescence in situ hybridization (FISH) studies for ETV6 translocation. CONCLUSION: MASC should be included in the differential diagnosis of mucinous salivary lesions with cystic changes on FNA. Immunohistochemistry for mammaglobin and S-100 helps in excluding morphologic mimics. FISH helps to confirm the diagnosis. Age alone should not be a deterrent in diagnosing a carcinoma.

Mammalian airborne allergens.

Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of house dust extract is briefly discussed in the historical context of two other proposed sources of house dust allergenic activity: mites and Maillard-type lysine-sugar conjugates. Mammalian proteins involved in allergic reactions to airborne dust are largely found in only 2 protein families: lipocalins and secretoglobins (Fel d 1-like proteins), with a relatively minor contribution of serum albumins, cystatins and latherins. Both the lipocalin and the secretoglobin family are very complex. In some instances this results in a blurred separation between important and less important allergenic family members. The past 50 years have provided us with much detailed information on the genomic organization and protein structure of many of these allergens. However, the complex family relations, combined with the wide range of post-translational enzymatic and non-enzymatic modifications, make a proper qualitative and quantitative description of the important mammalian indoor airborne allergens still a significant proteomic challenge.

Differential expression of secretoglobins in normal ovary and in ovarian carcinoma--overexpression of mammaglobin-1 is linked to tumor progression.

Secretoglobins (SCGB), such as mammaglobin 1 (MGB1, SCGB2A2), mammaglobin 2 (MGB2, SCGB2A1) and lipophilin B (LIPB, SCGB1D2), have been related to carcinogenesis. We profiled expression of MGB1, MGB2 and LIPB in human tissues and ovarian carcinoma and explored the impact of SCGB overexpression on cell proliferation. MGB1, MGB2 and LIPB mRNA are expressed at variable levels in most human tissues and we observed significant bilateral correlations between the different secretoglobins. Concerted overexpression of MGB1 and LIPB resulted in significant increase in cell proliferation. In clinical specimens of ovarian carcinoma we measured elevated concentrations of secretoglobin mRNA and for MGB1 this up-regulation was confirmed on the protein level. Overexpression of MGB1 positively correlated with the FIGO stage, the tumor grade and the mitotic index suggesting a patho-physiological role of the protein. Our data indicate that MGB1, MGB2 and LIPB mRNAs are expressed at low levels in human tissues but basal expression is upregulated in ovarian cancer. The in vivo correlation between nuclear MGB1 localization and the mitotic rate in ovarian cancer as well as the increased cell proliferation induced by secretoglobin overexpression in ovarian cancer cell lines suggest a pathophysiological role of these proteins in ovarian cancer.

Cytological features of mammary analogue secretory carcinoma of salivary gland: fine-needle aspiration of seven cases.

Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland neoplasm that is defined by ETV6-NTRK3 gene fusion. There have been few case reports on the cytopathologic features of MASC to date. We examined the clinicopathological and cytological features of seven cases of MASC defined by RT-PCR analysis of the ETV6-NTRK3 fusion gene. The cases occurred in three men and four women aged between 39 and 68 years, with a mean of 51.6 years. In five of these seven cases, the tumor involved the parotid gland. Histologically, all cases displayed predominantly microcystic patterns, often a mixture of follicular and papillary-cystic structures. All tumors were immunoreactive for mammaglobin, S-100 protein, and vimentin. Available fine-needle aspiration cytology smears were cellular and exhibited many loosely cohesive syncytial clusters or isolated cells. Many histiocytes, some of which contained hemosiderin pigments, and variously shaped mucinous material were evident in the background or within the epithelial clusters. The majority of cases showed small to medium-sized follicular structures with secreted materials. Papillary clusters were occasionally found. Tumor cells exhibited small to medium-sized round to oval nuclei, with a smooth contour and indistinct or small nucleoli, and vacuolated cytoplasm. No tumor cells had obvious intracytoplasmic zymogen granules. It appeared that clusters of small to medium-sized follicular and papillary configurations consisting of bland tumor cells with vacuolated cytoplasm, but lack of intracytoplasmic zymogen granules, in a mucinous or hemosiderin-laden histiocyte-rich background, were a characteristic cytological feature highly suggestive of MASC.

Neonatal hyperoxic exposure persistently alters lung secretoglobins and annexin A1.

Altered functions of the lung epithelial surface likely contribute to the respiratory morbidities in infants with bronchopulmonary dysplasia (BPD). Infants with BPD exhibit decreased expressions of secretoglobins (SCGBs), including Clara cell secretory protein (CCSP). Expression of lung SCGB and annexin A1 (ANXA1) is persistently altered in CCSP knockout mice suggesting that CCSP indirectly influences innate immune responses. The present studies tested the hypothesis that neonatal hyperoxic exposure induces deficits in CCSP expression that are associated with persistent alterations in lung SCGB and ANXA1 expression. Newborn C3H/HeN mice were exposed to room air (RA) or 85% O2 from birth and were sacrificed at 14 d or returned to RA for 14 d. Neonatal hyperoxia followed by RA recovery was associated with decreased lung CCSP and SCGB3A1 protein but not mRNA expression. Hyperoxia-induced alterations in the charge characteristics of ANXA1 were unchanged by RA recovery and were associated with elevated lung macrophage numbers. These findings support a model in which hyperoxia-induced alterations in Clara cell function influence lung innate immune function through effects on immunomodulatory proteins. Studies to determine the mechanism(s) by which CCSP alterations affect SCGBs, ANXA1, and innate immune responses in BPD are warranted.

Update of the human secretoglobin (SCGB) gene superfamily and an example of 'evolutionary bloom' of androgen-binding protein genes within the mouse Scgb gene superfamily.

The secretoglobins (SCGBs) comprise a family of small, secreted proteins found in animals exclusively of mammalian lineage. There are 11 human SCGB genes and five pseudogenes. Interestingly, mice have 68 Scgb genes, four of which are highly orthologous to human SCGB genes; the remainder represent an 'evolutionary bloom' and make up a large gene family represented by only six counterparts in humans. SCGBs are found in high concentrations in many mammalian secretions, including fluids of the lung, lacrimal gland, salivary gland, prostate and uterus. Whereas the biological activities of most individual SCGBs have not been fully characterised, what already has been discovered suggests that this family has an important role in the modulation of inflammation, tissue repair and tumorigenesis. In mice, the large Scgb1b and Scgb2b gene families encode the androgen-binding proteins, which have been shown to play a role in mate selection. Although much has been learned about SCGBs in recent years, clearly more research remains to be done to allow a better understanding of the roles of these proteins in human health and disease. Such information is predicted to reveal valuable novel drug targets for the treatment of inflammation, as well as designing biomarkers that might identify tissue damage or cancer.