Cytochemical localization of Na+-K+-ATPase in rat type II pneumocytes

1986 ◽  
Vol 60 (5) ◽  
pp. 1584-1589 ◽  
Author(s):  
E. E. Schneeberger ◽  
K. M. McCarthy

The distribution of sodium-potassium-activated adenosinetriphosphatase (Na+-K+-ATPase) in the alveolar portion of rat lungs was examined by indirect immunofluorescence with the use of a mouse monoclonal anti-rat Na+-K+-ATPase and by ultrastructural cytochemistry using p-nitrophenylphosphate as substrate. The reaction was inhibitable by 10 mM ouabain or by the omission of K+ from the reaction mixture. Cysteine or levamisole was used to inhibit alkaline phosphatase activity. By immunofluorescence, staining was confined to cuboidal cells in alveolar spaces. These were tentatively identified as type II pneumocytes. By ultrastructural cytochemistry reaction product was present on the cytoplasmic side of the basolateral membranes of type II pneumocytes. No reaction product was observed in type I pneumocytes or in endothelium. These results indicate that type II pneumocytes contain more Na+-K+-ATPase, an enzyme important in vectorial electrolyte transport, than type I pneumocytes or endothelial cells. More sensitive methods, however, are required to determine the amounts and distribution of this enzyme in type I pneumocytes and pulmonary vascular endothelial cells.

2003 ◽  
Vol 112 (10) ◽  
pp. 899-903 ◽  
Author(s):  
Seung Jun Oh ◽  
Yang-Gi Min ◽  
Seung-Ju Lee ◽  
Jeong-Whun Kim ◽  
Peter R. Jarin

Nitric oxide (NO), which is produced by nitric oxide synthase (NOS), has been recently identified as a multifunctional mediator. As for nasal tissue, however, the distribution and expression patterns of 3 isoforms of NOS, including neuronal NOS (nNOS, type I NOS), inducible NOS (iNOS, type II NOS), and endothelial NOS (eNOS, type III NOS), are still unclear. To evaluate the function of NO in the pathophysiology of nasal allergy, we investigated the distribution of NOSs in the nasal mucosa of C57BL/6 mice with allergic rhinitis to the house dust mite, Dermatophagoides farinae. Immunoreactivity to each isoform of NOS was immunohisto-chemically observed. In the allergic nasal mucosa, many eosinophils had infiltrated. Immunoreactivity to NOS types I and III was localized to the surface epithelial and vascular endothelial cells in both allergic and control groups without a statistically significant difference. In contrast, the type II NOS immunoreactivity was weak in normal mice and increased after allergic sensitization. The type II NOS expression of the surface epithelial and vascular endothelial cells was significantly elevated in the allergic group as compared with the control group. These findings suggest that a large amount of NO may be produced in the nasal mucosa of mice by type II NOS after allergic sensitization and that type II NOS may play an important role in the pathogenesis of allergic rhinitis.


2011 ◽  
Vol 34 (3) ◽  
pp. 138 ◽  
Author(s):  
Zhi Zhang ◽  
Guang Chu ◽  
Hong-Xian Wu ◽  
Ni Zou ◽  
Bao-Gui Sun ◽  
...  

Objective: The goal of this study was to investigate the crosstalk between vascular endothelial cells (ECs) and smooth muscle cells (SMCs) using a three-dimensional (3-D) co-culture model. In addition, the role of IL-8 in this crosstalk was investigated. Methods: A 3-D co-culture model was constructed using a Transwell chamber system and type I collagen gel. Human umbilical artery smooth muscle cells (HUASMCs) were suspended in the gel and added to the upper compartment of the Transwell. Human umbilical vein endothelial cells (HUVECs) were then grown on the surface of the gel. The growth of HUASMCs was tested with a CFDA SE cell proliferation kit. IL-8 and other bioactive substances were investigated by ELISA and real-time PCR. The alteration of p-ERK expression related to the change in IL-8 levels was also examined by Western blot analysis. Results: The proliferation rate of HUASMCs in the 3-D co-culture model was 0.679 ± 0.057. Secretion and transcription of VEGF, t-PA, NO and VCAM-1 in the 3-D co-culture model were different than in single (2-D) culture. When 3-D co-cultured, IL-8 released by HUVECs was significantly increased (2.35 ± 0.16 fold) (P﹤0.05) and the expression of VCAM-1 from HUASMCs was reduced accordingly (0.55±0.09 fold). In addition, increasing or decreasing the level of IL-8 changed the level of p-ERK and VCAM-1 expression. The reduction of VCAM-1, resulting from increased IL-8, could be blocked by the MEK inhibitor, PD98059. Conclusion: Crosstalk between HUVECs and HUASMCs occurred and was probably mediated by IL-8 in this 3-D co-culture model.


1998 ◽  
Vol 80 (12) ◽  
pp. 1008-1041 ◽  
Author(s):  
Matthias Kalbas ◽  
Antje Willuweit ◽  
Volker Henn ◽  
Richard Kroczek ◽  
Gert Müller-Berghaus ◽  
...  

SummaryCD40 is a type I member of the tumour necrosis factor (TNF) receptor superfamily of proteins, and is present on a wide variety of cells including vascular endothelial cells. Ligation of this receptor on endothelial cells is known to increase expression of inflammatory adhesion molecules. We have recently demonstrated that platelets express the ligand of CD40 (CD154) within seconds of exposure to agonist, and interact with endothelial cells to participate directly in the induction of an inflammatory response. Here we show that activated platelets induce tissue factor (TF) expression on endothelial cells in a CD40/CD154-dependent manner, and that the magnitude of this response can equal that induced by TNFα. Moreover, CD40 ligation on endothelial cells downregulates the expression of thrombomodulin. We also show that CD40-mediated TF expression is less sensitive to inhibition with the oxidative radical scavenger pyrrolidine dithiocarbamate than is that mediated by TNFα, indicating that CD40 has a distinct signalling pathway. Tissue factor is a cell membrane protein which functions as the main trigger of the extrinsic pathway of blood coagulation, and its expression on endothelial cells is implicated in wound healing and angiogenesis. Since platelets are among the first cells involved in haemostasis following tissue injury, our data showing that ligation of CD40 by CD154 induces a procoagulant phenotype on vascular endothelial cells suggests that platelets may play an important role in the induction of wound healing.


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