Silenced DMBT1 promotes nasal mucosa epithelial cell growth

DMBT1 Alleviates Nasal Airway Inflammatory Response in the LPS-Induced Nasal Polyp Model

INTRODUCTION

The aim of this study was to investigate the effects and mechanism of deleted in malignant brain tumors 1 (DMBT1) protein on the mouse model of nasal polyps.

METHODS

The mouse model of nasal polyps was induced by intranasal drip intervention of lipopolysaccharide (LPS) 3 times a week for 12 weeks. A total of 42 mice were randomly divided into blank group, LPS group, and LPS+DMBT1 group. DMBT1 protein was applied by intranasal drip intervention in each nostril after LPS. After 12 weeks, 5 mice in each group were randomly picked for the mouse olfactory disorder experiment, 3 mice were randomly picked for histopathological observation of nasal mucosa, 3 mice for olfactory marker protein (OMP) immunofluorescence analysis and the last 3 mice were grabbed for nasal lavage, and the levels of cytokines interleukin (IL)-4, IL-5, IL-13, and phosphatidylinositide 3-kinases (PI3K) in the nasal lavage fluid were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the blank group, mice in LPS group had olfactory dysfunction, the level of OMP was significantly reduced, the nasal mucosa was swollen, discontinuous, and contained a large number of inflammatory cells. The levels of IL-4, IL-5, IL-13, and PI3K in the nasal lavage fluid were significantly increased in LPS group (p < 0.01). Compared with the LPS group, the number of mice with olfactory dysfunction in the LPS+DMBT1 group was less, the infiltration of inflammatory cells was reduced, the OMP-positive cells were significantly increased, and the IL-4, IL-5, IL-13, and PI3K in the nasal lavage fluid were significantly increased, p < 0.01.

CONCLUSIONS

DMBT1 protein alleviates the nasal airway inflammatory response in the mouse nasal polyp model, and the mechanism may be through the PI3K-AKT signaling pathway.

Adiponectin is associated with inflammaging and age-related salivary gland lipid accumulation

Dry mouth is frequently observed in the elderly, and enhanced lipid accumulation plays a critical role in cellular senescence in the salivary gland (SG). We investigated the mechanisms that mediate lipogenesis-associated SG senescence. Adult (28.6 ± 6.6 y.o. and 43.3 ± 1.5 y.o.) and aged (82.0 ± 4.3 y.o. and 88.0 ± 4.3 y.o.) human parotid and submandibular glands were compared with respect to histologic findings, 8-OHdG (8-hydroxy 2 deoxyguanosine) expression patterns, TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) and SA-β-gal (senescence-associated β-galactosidase) assay results. Also, microarray analysis was performed on RNA extracted from adult and aged SG to identify DEGs (differentially expressed genes). The effects of silencing ADIPOQ (Adiponectin) were evaluated by quantifying cell proliferation, immunohistochemical staining for cellular senescence and inflammation-associated proteins, SA-β-gal assays, RT-PCR, and western blot. Histological findings demonstrated the presence of more lipocytes, chronic inflammation, fibrosis, and lymphocytic infiltration in old SG. In addition, old tissues demonstrated higher expressions of SA-β-gal, more apoptotic cells in TUNEL assays, and higher oxidative stress by 8-OHdG immunostaining. Microarray analysis showed lipogenesis was significantly upregulated in old tissues. Silencing of ADIPOQ (a lipogenesis-related gene) reduced inflammation and SA-β-gal levels and increased cell proliferation and the expressions of amylase and aquaporin 5 in human SG epithelial cells. The study shows ADIPOQ is a potential target molecule for the modulation of lipogenesis associated with SG senescence.

Evaluation of CSTB and DMBT1 expression in saliva of gastric cancer patients and controls

Background

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer deaths globally, with late diagnosis, low survival rate, and poor prognosis. This case-control study aimed to evaluate the expression of cystatin B (CSTB) and deleted in malignant brain tumor 1 (DMBT1) in the saliva of GC patients with healthy individuals to construct diagnostic algorithms using statistical analysis and machine learning methods.

Methods

Demographic data, clinical characteristics, and food intake habits of the case and control group were gathered through a standard checklist. Unstimulated whole saliva samples were taken from 31 healthy individuals and 31 GC patients. Through ELISA test and statistical analysis, the expression of salivary CSTB and DMBT1 proteins was evaluated. To construct diagnostic algorithms, we used the machine learning method.

Results

The mean salivary expression of CSTB in GC patients was significantly lower (115.55 ± 7.06, p = 0.001), and the mean salivary expression of DMBT1 in GC patients was significantly higher (171.88 ± 39.67, p = 0.002) than the control.

Multiple linear regression analysis demonstrated that GC was significantly correlated with high levels of DMBT1 after controlling the effects of age of participants (R² = 0.20, p < 0.001).

Considering salivary CSTB greater than 119.06 ng/mL as an optimal cut-off value, the sensitivity and specificity of CSTB in the diagnosis of GC were 83.87 and 70.97%, respectively. The area under the ROC curve was calculated as 0.728. The optimal cut-off value of DMBT1 for differentiating GC patients from controls was greater than 146.33 ng/mL (sensitivity = 80.65% and specificity = 64.52%). The area under the ROC curve was up to 0.741.

As a result of the machine learning method, the area under the receiver-operating characteristic curve for the diagnostic ability of CSTB, DMBT1, demographic data, clinical characteristics, and food intake habits was 0.95. The machine learning model’s sensitivity, specificity, and accuracy were 100, 70.8, and 80.5%, respectively.

Conclusion

Salivary levels of DMBT1 and CSTB may be accurate in diagnosing GCs. Machine learning analyses using salivary biomarkers, demographic, clinical, and nutrition habits data simultaneously could provide affordability models with acceptable accuracy for differentiation of GC by a cost-effective and non-invasive method.

Quercetin attenuates lipopolysaccharide-mediated inflammatory injury in human nasal epithelial cells via regulating miR-21/DMBT1/NF-κB axis

BACKGROUND

Quercetin (Qu) belongs to a flavonoid polyphenolic compound present in fruits and vegetables which has been confirmed to exert anti-inflammatory properties. Our study aimed to explore the impacts of quercetin on lipopolysaccharide (LPS)-induced inflammatory injury and signal transduction of miR-21/DMBT1/NF-κB axis in human nasal epithelial cells (HNEpC).

METHODS

HNEpCs were cultured and treated with 1 μg/mL of LPS and a gradient concentration (10, 100, and 200 μM) of quercetin for 24 h. Cell viability, apoptosis, and cytokines were detected to assess the inflammatory injury in LPS-exposed HNEpCs. The expressions of miR-21, DMBT1, and NF-κB mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of DMBT1 and NF-κB protein were measured by western blotting.

RESULTS

LPS treatment reduced cell viability, promoted cell apoptosis and inflammatory response, down-regulated miR-21 expression and up-regulated DMBT1, and NF-κB in HNEpC cells. Quercetin exerted the opposite effects to attenuate LPS-induced inflammatory injury in HNEpC cells at a concentration-dependent way. Additionally, miR-21 directly targeted DMBT1 to reduce its expression and further inducing cell viability via inhibiting cell apoptosis and inflammatory response. MiR-21 inhibition or DMBT1 over-expression weakened the protective effects of quercetin against LPS-induced inflammatory injury in HNEpC cells.

CONCLUSIONS

Quercetin could protect HNEpC cells against LPS-induced inflammatory injury via inducing miR-21/DMBT1/NF-κB axis. Therefore, quercetin could be utilized as a potential compound to treat for allergic rhinitis.

Proteomic analysis of nasal mucus samples of healthy patients and patients with chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) has a complex and multifactorial pathogenesis with a heterogeneous inflammatory profile. Proteomic analysis of nasal mucus may enable further understanding of protein abundances and biologic processes present in CRS and its endotypes compared with in healthy patients.

OBJECTIVE

Our aim was to determine differences in the nasal mucus proteome of healthy patients and patients with CRS.

METHODS

Nasal mucus was obtained from healthy patients, patients with CRS without nasal polyps (CRSsNP), and patients with CRS with nasal polyps (CRSwNP) before surgery. Gel electrophoresis was performed to fractionate the complex protein extracts before mass spectrometry analysis. Gene set enrichment analysis was performed on differentially expressed proteins.

RESULTS

A total of 33 patients were included in this study (12 healthy, 10 with CRSsNP, and 11 with CRSwNP). In all, 1142 proteins were identified in mucus samples from healthy patients, 761 in mucus samples from patients with CRSsNP, and 998 in mucus samples from patients with CRSwNP. Dysfunction in immunologic pathways, reduced cellular signaling, and increased cellular metabolism with associated tissue remodeling pathways were present in patients with CRS compared with in healthy patients.

CONCLUSION

Significant downregulation of mucosal immunity and antioxidant pathways with increased tissue modeling processes may account for the clinical manifestations of CRS. Ultimately, the differing proteome and biologic processes provide further insight into CRS pathogenesis and its endotypes.

Postnatal Gut Immunity and Microbiota Development Is Minimally Affected by Prenatal Inflammation in Preterm Pigs

Chorioamnionitis (CA), resulting from intra-amniotic inflammation, is a frequent cause of preterm birth and exposes the immature intestine to bacterial toxins and/or inflammatory mediators before birth via fetal swallowing. This may affect intestinal immune development, interacting with the effects of enteral feeding and gut microbiota colonization just after birth. Using preterm pigs as model for preterm infants, we hypothesized that prenatal exposure to gram-negative endotoxin influences postnatal bacterial colonization and gut immune development. Pig fetuses were given intra-amniotic lipopolysaccharide (LPS) 3 days before preterm delivery by cesarean section and were compared with littermate controls (CON) at birth and after 5 days of formula feeding and spontaneous bacterial colonization. Amniotic fluid was collected for analysis of leukocyte counts and cytokines, and the distal small intestine was analyzed for endotoxin level, morphology, and immune cell counts. Intestinal gene expression and microbiota were analyzed by transcriptomics and metagenomics, respectively. At birth, LPS-exposed pigs showed higher intestinal endotoxin, neutrophil/macrophage density, and shorter villi. About 1.0% of intestinal genes were affected at birth, and DMBT1, a regulator of mucosal immune defense, was identified as the hub gene in the co-expression network. Genes related to innate immune response (TLR2, LBP, CD14, C3, SFTPD), neutrophil chemotaxis (C5AR1, CSF3R, CCL5), and antigen processing (MHC II genes and CD4) were also affected, and expression levels correlated with intestinal neutrophil/macrophage density and amniotic fluid cytokine levels. On day 5, LPS and CON pigs showed similar sensitivity to necrotizing enterocolitis, endotoxin levels, morphology, immune cell counts, gene expressions, and microbiota composition (except for difference in some low-abundant species). Our results show that CA markedly affects intestinal genes at preterm birth, including genes related to immune cell infiltration. However, a few days later, following the physiological adaptations to preterm birth, CA had limited effects on intestinal structure, function, gene expression, bacterial colonization, and necrotizing enterocolitis sensitivity. We conclude that short-term, prenatal intra-amniotic inflammation is unlikely to exert marked effects on intestinal immune development in preterm neonates beyond the immediate neonatal period.