Pbx1, Meis1, and Runx1 Expression Is Decreased in the Diaphragmatic and Pulmonary Mesenchyme of Rats with Nitrofen-Induced Congenital Diaphragmatic Hernia

Author(s):  
Toshiaki Takahashi ◽  
Florian Friedmacher ◽  
Julia Zimmer ◽  
Prem Puri

Abstract Introduction Congenital diaphragmatic hernia (CDH) and associated pulmonary hypoplasia (PH) are thought to originate from mesenchymal defects in pleuroperitoneal folds (PPFs) and primordial lungs. Pre-B-cell leukemia homeobox 1 (Pbx1), its binding partner myeloid ecotropic integration site 1 (Meis1), and runt-related transcription factor 1 (Runx1) are expressed in diaphragmatic and lung mesenchyme, functioning as transcription cofactors that modulate mesenchymal cell proliferation. Furthermore, Pbx1 −/− mice develop diaphragmatic defects and PH similar to human CDH. We hypothesized that diaphragmatic and pulmonary Pbx1, Meis1, and Runx1 expression is decreased in the nitrofen-induced CDH model. Materials and Methods Time-mated rats were exposed to nitrofen or vehicle on gestational day 9 (D9). Fetal diaphragms (n = 72) and lungs (n = 48) were microdissected on D13, D15, and D18, and were divided into control and nitrofen-exposed specimens. Diaphragmatic and pulmonary gene expression levels of Pbx1, Meis1, and Runx1 were analyzed by quantitative real-time polymerase chain reaction. Immunofluorescence-double-staining for Pbx1, Meis1, and Runx1 was combined with mesenchymal/myogenic markers Gata4 and myogenin to evaluate protein expression. Results Relative mRNA expression of Pbx1, Meis1, and Runx1 was significantly decreased in PPFs (D13), developing diaphragms/lungs (D15), and muscularized diaphragms/differentiated lungs (D18) of nitrofen-exposed fetuses compared with controls. Confocal-laser-scanning-microscopy revealed markedly diminished Pbx1, Meis1, and Runx1 immunofluorescence in diaphragmatic and pulmonary mesenchyme, associated with less proliferating mesenchymal cells in nitrofen-exposed fetuses on D13, D15, and D18 compared with controls. Conclusion Decreased Pbx1, Meis1, and Runx1 expression during diaphragmatic development and lung branching morphogenesis may reduce mesenchymal cell proliferation, causing malformed PPFs and disrupted airway branching, thus leading to diaphragmatic defects and PH in the nitrofen-induced CDH model.

2018 ◽  
Vol 29 (01) ◽  
pp. 113-119
Author(s):  
Toshiaki Takahashi ◽  
Florian Friedmacher ◽  
Julia Zimmer ◽  
Prem Puri

Introduction Congenital diaphragmatic hernia (CDH) is assumed to originate from a malformation of the amuscular mesenchymal component of the primordial diaphragm. Mutations in ephrin-B1, a membrane protein that is expressed by mesenchymal cells, have been found in newborn infants with CDH and associated pulmonary hypoplasia (PH), highlighting its important role during diaphragmatic and airway development. Ephrin-B1, -B2, and -B4 are expressed in fetal rat lungs and have been identified as key players during lung branching morphogenesis. We hypothesized that diaphragmatic and pulmonary expression of ephrin-B1, -B2, and -B4 is decreased in the nitrofen-induced CDH model. Materials and Methods Time-mated rats received nitrofen or vehicle on day 9 (D9). Fetal diaphragms (n = 72) and lungs (n = 72) were harvested on D13, D15, and D18, and divided into control and nitrofen-exposed specimens. Ephrin-B1, -B2, and -B4 gene expression was analyzed by quantitative real-time polymerase chain reaction. Immunofluorescence double staining for ephrin-B1, -B2, and -B4 was combined with mesenchymal and epithelial markers (Gata-4/Fgf-10 and calcitonin gene-related peptide) to evaluate protein expression/localization. Results Ephrin-B1, -B2, and -B4 gene expression was significantly reduced in pleuroperitoneal folds/primordial lungs (D13), developing diaphragms/lungs (D15), and fully muscularized diaphragms/differentiated lungs (D18) of nitrofen-exposed fetuses compared with controls. Confocal laser scanning microscopy demonstrated markedly diminished ephrin-B1 immunofluorescence in diaphragmatic and pulmonary mesenchyme of nitrofen-exposed fetuses on D13, D15, and D18 compared with controls, whereas ephrin-B2 and -B4 expression was mainly decreased in distal airway epithelium. Conclusion Decreased ephrin-B1, -B2, and -B4 expression may disrupt diaphragmatic development and lung branching morphogenesis by interfering with epithelial–mesenchymal interactions, thus causing diaphragmatic defects and PH.


2008 ◽  
Vol 75 (3) ◽  
pp. 848-852 ◽  
Author(s):  
Joseph C. Brown ◽  
Guohui Huang ◽  
Vivian Haley-Zitlin ◽  
Xiuping Jiang

ABSTRACT Anti-Helicobacter pylori activities were determined by agar dilution, confocal laser scanning microscopy, and cell proliferation assays following treatment with various grape extracts. Muscadine grape skin possessed the strongest activity, followed by grape synergy (skin and seed) and seed, suggesting that higher phenolic levels do not necessarily determine overall anti-H. pylori efficacy.


2018 ◽  
Vol 46 (8) ◽  
pp. 3285-3295 ◽  
Author(s):  
Jie Sheng ◽  
Li-Bin Sun ◽  
Shu-Fen Zhao ◽  
Wei-Wei Qi ◽  
Jing Lv ◽  
...  

Objective To investigate the effect of acidity on gastric cancer SGC7901 cells in terms of autophagy and provide a new strategy for therapeutically targeting gastric cancer autophagy in an acidic environment. Methods Transmission electron microscopy (TEM) and confocal laser scanning microscopy were used to examine the effect of an acidic environment on autophagosome formation. Light chain 3 (LC3) and p62 levels in SGC7901 cells exposed to acidic conditions were measured using Western blot analysis. To explore changes in autophagy flux, the cells were treated with an inhibitor of autophagy bafilomycin A1. The CCK-8 assay was performed to determine if inhibiting acid-induced autophagy affected cell proliferation. Results Increased autophagosome formation was observed by TEM. Punctate LC3 structures were observed in cells cultured under acidic conditions, whereas untreated cells exhibited diffuse and weak staining for punctate LC3 structures. Cytoplasmic LC3-I translocated to the autophagic membrane (LC3-II) levels increased under acidic conditions, whereas p62 levels decreased. The bafilomycin A1-induced inhibition of autophagy caused by the acidic environment inhibited cell proliferation. Conclusion The acidic environment upregulates autophagy in SGC7901 cells. In long-term culture, a stable and high level of autophagy is maintained in an acidic environment, which has a protective effect on cells.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 832
Author(s):  
Li-Yu Chen ◽  
Gurunath Apte ◽  
Annerose Lindenbauer ◽  
Marion Frant ◽  
Thi-Huong Nguyen

Cancer cells circulating in blood vessels activate platelets, forming a cancer cell encircling platelet cloak which facilitates cancer metastasis. Heparin (H) is frequently used as an anticoagulant in cancer patients but up to 5% of patients have a side effect, heparin-induced thrombocytopenia (HIT) that can be life-threatening. HIT is developed due to a complex interaction among multiple components including heparin, platelet factor 4 (PF4), HIT antibodies, and platelets. However, available information regarding the effect of HIT components on cancers is limited. Here, we investigated the effect of these materials on the mechanical property of breast cancer cells using atomic force microscopy (AFM) while cell spreading was quantified by confocal laser scanning microscopy (CLSM), and cell proliferation rate was determined. Over time, we found a clear effect of each component on cell elasticity and cell spreading. In the absence of platelets, HIT antibodies inhibited cell proliferation but they promoted cell proliferation in the presence of platelets. Our results indicate that HIT complexes influenced the development of breast cancer cells.


2021 ◽  
Author(s):  
Elanna Bester ◽  
Gideon M. Wolfaardt ◽  
Nahid B. Aznaveh ◽  
Jesse Greener

The detachment of single cells from biofilms is an intrinsic part of this surface-associated mode of bacterial existence. Pseudomonas sp. strain CT07gfp biofilms, cultivated in microfluidic channels under continuous flow conditions, were subjected to a range of liquid shear stresses (9.42 mPa to 320 mPa). The number of detached planktonic cells was quantified from the effluent at 24-h intervals, while average biofilm thickness and biofilm surface area were determined by confocal laser scanning microscopy and image analysis. Biofilm accumulation proceeded at the highest applied shear stress, while similar rates of planktonic cell detachment was maintained for biofilms of the same age subjected to the range of average shear rates. The conventional view of liquid-mediated shear leading to the passive erosion of single cells from the biofilm surface, disregards the active contribution of attached cell metabolism and growth to the observed detachment rates. As a complement to the conventional conceptual biofilm models, the existence of a biofilm surface-associated zone of planktonic cell proliferation is proposed to highlight the need to expand the traditional perception of biofilms as promoting microbial survival, to include the potential of biofilms to contribute to microbial proliferation.


2017 ◽  
Vol 28 (01) ◽  
pp. 109-114 ◽  
Author(s):  
Toshiaki Takahashi ◽  
Florian Friedmacher ◽  
Julia Zimmer ◽  
Prem Puri

Introduction Pulmonary hypoplasia (PH), characterized by smaller lung size and reduced airway branching, remains a major cause of neonatal mortality in newborns with congenital diaphragmatic hernia (CDH). Integrin-mediated cell–matrix interactions play an essential role in the fetal lung mesenchyme by stimulating branching morphogenesis. Mice lacking integrin subunits α3 (Itga3) and α6 (Itga6) exhibit severe PH. Furthermore, Itga8-knockout mice show defective airway branching, suggesting that Itga3, Itga6, and Itga8 are crucial for fetal lung development. We hypothesized that expression of Itga3, Itga6, and Itga8 is decreased in the branching airway mesenchyme of hypoplastic rat lungs in the nitrofen-induced CDH model. Materials and Methods Time-mated rats received nitrofen or vehicle on gestational day 9 (D9). Fetuses were sacrificed on D15, D18, and D21, and dissected lungs were divided into control and nitrofen-exposed specimens (n = 12 per time-point and group, respectively). Pulmonary gene expression of Itga3, Itga6, and Itga8 was analyzed by quantitative real-time polymerase chain reaction. Immunofluorescence double-staining for Itga3, Itga6, and Itga8 was combined with the mesenchymal marker Fgf10 to evaluate protein expression and localization in branching airway tissue. Results Relative mRNA expression of Itga3, Itga6, and Itga8 was significantly decreased in lungs of nitrofen-exposed fetuses on D15, D18, and D21 compared with controls. Confocal laser scanning microscopy showed markedly diminished immunofluorescence of Itga3, Itga6, and Itga8 mainly in mesenchymal cells surrounding branching airways of nitrofen-exposed fetuses on D15, D18, and D21 compared with controls. Conclusion Decreased expression of Itga3, Itga6, and Itga8 in the pulmonary mesenchyme may lead to disruptions in airway branching morphogenesis, thus contributing to PH in the nitrofen-induced CDH model.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yingzhen Lai ◽  
Zhiqiang Xu ◽  
Jiang Chen ◽  
Renbin Zhou ◽  
Jumei Tian ◽  
...  

Objectives. To investigate the physical properties of the modified microgroove (MG) and antibacterial nanocoated surfaces. In addition, the biological interactions of the modified surfaces with human gingival fibroblasts (HGFs) and the antibacterial activity of the surfaces against Porphyromonas gingivalis were studied. Methods. The titanium nitride (TiN) and silver (Ag) coatings were deposited onto the smooth and MG surfaces using magnetron sputtering. A smooth titanium surface (Ti-S) was used as the control. The physicochemical properties including surface morphology, roughness, and hydrophilicity were characterized using scanning electron microscopy, atomic force microscopy, and an optical contact angle analyzer. The “contact guidance” morphology was assessed using confocal laser scanning microscopy. Cell proliferation was analyzed using the Cell Counting Kit-8 assay. The expression level of the main focal adhesion-related structural protein vinculin was compared using quantitative reverse transcription PCR and Western blotting. The antibacterial activity against P. gingivalis was evaluated using the LIVE/DEAD BacLight™ Bacterial Viability Kit. Results. The Ag and TiN antibacterial nanocoatings were successfully deposited onto the smooth and MG surfaces using magnetron sputtering technology. TiN coating on a grooved surface (TiN-MG) resulted in less nanoroughness and greater surface hydrophilicity than Ag coating on a smooth surface (Ag-S), which was more hydrophobic. Cell proliferation and expression of vinculin were higher on the TiN-MG surface than on the Ag-coated surfaces. Ag-coated surfaces showed the strongest antibacterial activity, followed by TiN-coated surfaces. Conclusion. Nano-Ag coating resulted in good antimicrobial activity; however, the biocompatibility was questionable. TiN nanocoating on an MG surface showed antibacterial properties with an optimal biocompatibility and maintained the “contact guidance” effects for HGFs.


2021 ◽  
Author(s):  
Elanna Bester ◽  
Gideon M. Wolfaardt ◽  
Nahid B. Aznaveh ◽  
Jesse Greener

The detachment of single cells from biofilms is an intrinsic part of this surface-associated mode of bacterial existence. Pseudomonas sp. strain CT07gfp biofilms, cultivated in microfluidic channels under continuous flow conditions, were subjected to a range of liquid shear stresses (9.42 mPa to 320 mPa). The number of detached planktonic cells was quantified from the effluent at 24-h intervals, while average biofilm thickness and biofilm surface area were determined by confocal laser scanning microscopy and image analysis. Biofilm accumulation proceeded at the highest applied shear stress, while similar rates of planktonic cell detachment was maintained for biofilms of the same age subjected to the range of average shear rates. The conventional view of liquid-mediated shear leading to the passive erosion of single cells from the biofilm surface, disregards the active contribution of attached cell metabolism and growth to the observed detachment rates. As a complement to the conventional conceptual biofilm models, the existence of a biofilm surface-associated zone of planktonic cell proliferation is proposed to highlight the need to expand the traditional perception of biofilms as promoting microbial survival, to include the potential of biofilms to contribute to microbial proliferation.


Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.


Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.


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