Article

Expression and Localization of Lung Surfactant Protein A in Human Tissues

Department of Immunology and Microbiology, Institute of Medical Biology, University of Southern Denmark, Winsløwparken 21.1, DK-5000 Odense C, Denmark.
American Journal of Respiratory Cell and Molecular Biology (Impact Factor: 3.99). 12/2003; 29(5):591-7. DOI: 10.1165/rcmb.2002-0274OC
Source: PubMed

ABSTRACT

Lung surfactant protein A (SP-A) is a collectin produced by alveolar type II cells and Clara cells. It binds to carbohydrate structures on microorganisms, initiating effector mechanisms of innate immunity and modulating the inflammatory response in the lung. Reverse transcriptase-polymerase chain reaction was performed on a panel of RNAs from human tissues for SP-A mRNA expression. The lung was the main site of synthesis, but transcripts were readily amplified from the trachea, prostate, pancreas, and thymus. Weak expression was observed in the colon and salivary gland. SP-A sequences derived from lung and thymus mRNA revealed the presence of both SP-A1 and SP-A2, whereas only SP-A2 expression was found in the trachea and prostate. Monoclonal antibodies were raised against SP-A and characterized. One of these (HYB 238-4) reacted in Western blotting with both reduced and unreduced SP-A, with N-deglycosylated and collagenase-treated SP-A, and with both recombinant SP-A1 and SP-A2. This antibody was used to demonstrate SP-A in immunohistochemistry of human tissues. Strong SP-A immunoreactivity was seen in alveolar type-II cells, Clara cells, and on and within alveolar macrophages, but no extrapulmonary SP-A immunoreactivity was observed. In contrast to lung surfactant protein D (SP-D), which is generally expressed on mucosal surfaces, SP-A seems to be restricted to the respiratory system.

0 Followers
 · 
3 Reads
  • Source
    • "In lungs, SP-A and SP-D are synthesized and secreted by alveolar type II and Clara cells at the air-liquid interface of the surfactant (Crouch et al., 1992; Voorhout et al., 1992). Expression of SP-A and SP-D has also been reported in extra pulmonary tissues such as brain, salivary glands, lachrymal glands, heart, trachea, kidney, pancreas , thymus, spleen, gall bladder, esophagus, small intestine, large intestine, testis, prostate and urinary tract (Madsen et al., 2003; Herías et al., 2007; Breuiller-Fouché et al., 2010; Nayak et al., 2012; Schicht et al., 2015). In addition, reproductive tissues have also been shown to express both SP-A and SP-D (Sati et al., 2009; Condon et al., 2004; Yadav et al., 2011). "

    Full-text · Dataset · Oct 2015
  • Source
    • "Please cite this article as: Kaisani, A., et al., Branching morphogenesis of immortalized human bronchial epithelial cells in threedimensional culture. Differentiation (2014), http://dx.doi.org/10.1016/j.diff.2014.02.003i which is expressed in both Type II pneumocytes and Clara cells (Madsen et al., 2003). Although SP-A is expressed in HBEC3 KTs in 2D culture, expression of SP-A in 3D is more representative of its expression and secretion in vivo. "
    [Show abstract] [Hide abstract]
    ABSTRACT: While mouse models have contributed in our understanding of lung development, repair and regeneration, inherent differences between the murine and human airways requires the development of new models using human airway epithelial cells. In this study, we describe a three-dimensional model system using human bronchial epithelial cells (HBECs) cultured on reconstituted basement membrane. HBECs form complex budding and branching structures on reconstituted basement membrane when co-cultured with human lung fetal fibroblasts. These structures are reminiscent of the branching epithelia during lung development. The HBECs also retain markers indicative of epithelial cell types from both the central and distal airways suggesting their multipotent potential. In addition, we illustrate how the model can be utilized to understand respiratory diseases such as lung cancer. The 3D novel cell culture system recapitulates stromal-epithelial interactions in vitro that can be utilized to understand important aspects of lung development and diseases.
    Full-text · Article · May 2014 · Differentiation
  • Source
    • "Please cite this article as: Kaisani, A., et al., Branching morphogenesis of immortalized human bronchial epithelial cells in threedimensional culture. Differentiation (2014), http://dx.doi.org/10.1016/j.diff.2014.02.003i which is expressed in both Type II pneumocytes and Clara cells (Madsen et al., 2003). Although SP-A is expressed in HBEC3 KTs in 2D culture, expression of SP-A in 3D is more representative of its expression and secretion in vivo. "

    Full-text · Article · Jan 2014 · Differentiation
Show more