Bei Mu Gua Lou San facilitates mucus expectoration by increasing surface area and hydration levels of airway mucus in an air-liquid-interface cell culture model of the respiratory epithelium.

BACKGROUND: Bei Mu Gua Lou San (BMGLS) is an ancient formulation known for its moisturizing and expectorant properties, but the underlying mechanisms remain unknown. We investigated concentration-dependent effects of BMGLS on its rehydrating and mucus-modulating properties using an air-liquid-interface (ALI) cell culture model of the Calu-3 human bronchial epithelial cell line and primary normal human bronchial epithelial cells (NHBE), and specifically focused on quantity and composition of the two major mucosal proteins MUC5AC and MUC5B. METHODS: ALI cultures were treated with BMGLS at different concentrations over three weeks and evaluated by means of histology, immunostaining and electron microscopy. MUC5AC and MUC5B mRNA levels were assessed and quantified on protein level using an automated image-based approach. Additionally, expression levels of the major mucus-stimulating enzyme 15-lipoxygenase (ALOX15) were evaluated. RESULTS: BMGLS induced concentration-dependent morphological changes in NHBE but not Calu-3 ALI cultures that resulted in increased surface area via the formation of herein termed intra-epithelial structures (IES). While cellular rates of proliferation, apoptosis or degeneration remained unaffected, BMGLS caused swelling of mucosal granules, increased the area of secreted mucus, decreased muco-glycoprotein density, and dispensed MUC5AC. Additionally, BMGLS reduced expression levels of MUC5AC, MUC5B and the mucus-stimulating enzyme 15-lipoxygenase (ALOX15). CONCLUSIONS: Our studies suggest that BMGLS rehydrates airway mucus while stimulating mucus secretion by increasing surface areas and regulating goblet cell differentiation through modulating major mucus-stimulating pathways.

Quantification of increased MUC5AC expression in airway mucus of smoker using an automated image-based approach.

Microscopic analysis of mucus quantity and composition is crucial in research and diagnostics on muco-obstructive diseases. Currently used image-based methods are unable to extract concrete numeric values of mucosal proteins, especially on the expression of the key mucosal proteins MUC5AC and MUC5B. Since their levels increase under pathologic conditions such as extensive exposure to cigarette smoke, it is imperative to quantify them to improve treatment strategies of pulmonary diseases. This study presents a simple, image-based, and high-processing computational method that allows determining the ratio of MUC5AC and MUC5B within the overall airway mucus while providing information on their spatial distribution. The presented pipeline was optimized for automated downstream analysis using a combination of bright field and immunofluorescence imaging suitable for tracheal and bronchial tissue samples, and air-liquid interface (ALI) cell cultures. To validate our approach, we compared tracheal tissue and ALI cell cultures of isolated primary normal human bronchial epithelial cells derived from smokers and nonsmokers. Our data indicated 18-fold higher levels of MUC5AC in submucosal glands of smokers covering about 8% of mucosal areas compared to <1% in nonsmoking individuals, confirming results of previous studies. We further identified a subpopulation of nonsmokers with slightly elevated glandular MUC5AC levels suggesting moderate exposure to second-hand smoke or fine particulate air pollution. Overall, this study demonstrates a novel, user-friendly and freely available tool for digital pathology and the analysis of therapeutic interventions tested in ALI cell cultures.

Histological processing of un-/cellularized thermosensitive electrospun scaffolds.

Histological processing of thermosensitive electrospun poly(ε-caprolactone)/poly(L-lactide) (PCL/PLA) scaffolds fails, as poly(ε-caprolactone) (PCL) is characterized by its low-melting temperature (Tm = 60 °C). Here, we present an optimized low-temperature preparation method for the histological processing of un-/cellularized thermosensitive PCL/PLA scaffolds.Our study is aimed at the establishment of an optimized dehydration and low-melting-point paraffin-embedding method of electrospun PCL/PLA scaffolds (un-/cellularized). Furthermore, we compared this method with (a) automatized dehydration and standard paraffin embedding, (b) gelatin embedding followed by automatized dehydration and standard paraffin embedding, (c) cryofixation, and (d) acrylic resin embedding methods. We investigated pepsin and proteinase K antigen retrieval for their efficiency in epitope demasking at low temperatures and evaluated protocols for immunohistochemistry and immunofluorescence for cytokeratin 7 (CK7) and in situ padlock probe technology for beta actin (ACTB). Optimized dehydration and low-melting-point paraffin embedding preserved the PCL/PLA scaffold, as the diameter and structure of its fibers were unchanged. Cells attached to the PCL/PLA scaffolds showed limited alterations in size and morphology compared to control. Epitope demasking by enzymatic pepsin digestion and immunostaining of CK7 displayed an invasion of attached cells into the scaffold. Expression of ACTB and CK7 was shown by a combination of mRNA-based in situ padlock probe technology and immunofluorescence. In contrast, gelatin stabilization followed by standard paraffin embedding led to an overall shrinkage and melting of fibers, and therefore, no further analysis was possible. Acrylic resin embedding and cyrofixation caused fiber structures that were nearly unchanged in size and diameter. However, acrylic resin-embedded scaffolds are limited to 3 µm sections, whereas cyrofixation led to a reduction of the cell size by 14% compared to low-melting paraffin embedding. The combination of low-melting-point paraffin embedding and pepsin digestion as an antigen retrieval method offers a successful opportunity for histological investigations in thermosensitive specimens.

Bai Hu Tang, Si Ni Tang, and Xue Bi Tang amplify pro-inflammatory activities and reduce apoptosis in endothelial cells in a cell culture model of sepsis.

ETHNOPHARMACOLOGICAL RELEVANCE: Sepsis is a systemic inflammatory response of the body to a severe infection or massive tissue injury. Despite intensive research, sepsis continues to have a high mortality rate and successful treatment options are strongly needed. Bai Hu Tang (BHT), Si Ni Tang (SNT), and Xue Bi Tang (XBT) are ancient traditional Chinese formulas derived from Chinese herbs that are used to treat Sepsis, but their mechanisms of activity are largely unknown. AIM OF THE STUDY: We aimed to examine dose-dependent effects of BHT, SNT, and XBT in a cell culture model of Sepsis, with special focus on endothelial cell apoptosis and the expression of monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)6, IL8, the surface adhesion molecule intercellular adhesion molecule-1 (ICAM-1) and endothelial-leukocyte adhesion molecule-1 (ELAM-1). MATERIAL AND METHODS: We stimulated THP1 monocytic cells with lipopolysaccharide (LPS, Escherichia coli (E. coli)) for 4 h and used the resulting culture medium to stimulate human umbilical vein endothelial cells (HUVECs). HUVECs were also simultaneously treated with hydrophilic concentrates of BHT, SNT or XBT. We evaluated the mRNA and protein expression levels of IL6, IL8, MCP-1, ICAM-1, and ELAM-1 and the activity of caspase 3/7, a marker of cell apoptosis, after stimulation and treatment. In addition, we stimulated cannulated veins from human umbilical cords for 24 h and treated them with BHT, SNT or XBT. Immunohistochemistry visualized expression of ICAM-1 and ELAM-1. RESULTS: The mRNA and protein levels of IL6, IL8, ICAM-1, and ELAM-1 were higher in stimulated HUVECs than in controls. Treating stimulated HUVECs with BHT, SNT or XBT induced an additional increase in IL6 (13- to 132-fold) and IL8 (17- to 32-fold) mRNA levels but did not influence their protein levels. In addition, BHT induced an additional increase in ICAM-1 mRNA (9-fold) expression, whereas XBT increased the mRNA and protein levels of ELAM-1 by 42-fold and 10-fold, respectively. Finally, caspase 3/7 levels, and therefore apoptosis, were up to 100% lower in cells treated with BHT than in the stimulated control (P < 0.001). CONCLUSION: The results of this study indicate that BHT, SNT, and XBT interfere in inflammatory pathways during septic processes by reducing the apoptotic effects of LPS and modifying the endothelial expression of pro-inflammatory cytokines and surface adhesion molecules.

A novel sandwich ELISA for alpha1 domain based detection of soluble HLA-G heavy chains.

The detection of soluble human leukocyte antigen G (HLA-G) has been a technically demanding task for several years now and various enzyme linked immunosorbent assay (ELISA) formats have been designed. However, no ELISA test has been described so far which is able to detect all possible kinds of soluble HLA-G (sHLA-G) molecules that might occur in bio fluids. Here we describe a new ELISA approach able to recognize soluble alpha1 domain containing heavy chains of all HLA-G isoforms. The detection limit is shown to be at about 150 pg soluble recombinant HLA-G1 heavy chain per milliliters. Detectable HLA-G fragments are shown to occur in the supernatants of different HLA-G transfected cell lines and appear to be particularly abundant in supernatant of trophoblast derived choriocarcinoma cell lines. The novel ELISA employs the well characterized HLA-G mAbs 4H84 and MEM-G1 which ensure high HLA-G specificity. A negative control ELISA format, designed against non-existing analytes, has been established to reveal non-specific signal interference.