Surfactant protein-A (SP-A) plays an important role in the clearance of surfactant from the lung alveolar space and in the regulation of surfactant secretion and uptake by type II pneumocytes in culture. Two pathways are important for the endocytosis of surfactant by type II cells and the intact lung, a receptor-mediated clathrin-dependent pathway and a non-clathrin, actin-mediated pathway. The critical role of the clathrin/receptor-mediated pathway in normal mice is supported by the finding that SP-A gene-targeted mice use the actin-dependent pathway to maintain normal clearance of surfactant. Addition of SP-A to the surfactant of the SP-A null mice "rescued" the phenotype, further emphasizing the essential role of the SP-A/receptor-mediated process in surfactant turnover. This review presents an overview of the structure of SP-A and its function in surfactant turnover. The evidence that the interaction of SP-A with type II cells is a receptor-mediated process is presented. A newly identified receptor for SP-A, P63/CKAP4, is described in detail, with elucidation of the specific structural features of this 63 kDa, nonglycosylated, highly coiled, transmembrane protein. The compelling evidence that P63 functions as a receptor for SP-A on type II cells is summarized. Regulation of P63 receptor density on the surface of pneumocytes may be a novel approach for the regulation of surfactant homeostasis by the lung.
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http://dx.doi.org/10.1159/000272062 | DOI Listing |
Front Immunol
January 2025
Department Integrative Agriculture, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain, United Arab Emirates.
Surfactant protein D (SP-D) is a C-type lectin that was originally discovered as a lung surfactant associated phospholipid recognising protein. It was originally shown to be of great importance in surfactant turnover and homeostasis in conjunction with another hydrophilic surfactant protein i.e.
View Article and Find Full Text PDFPLoS One
December 2024
Division of Biology, Chemistry, and Materials Science, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration (FDA), Silver Spring, MD, United States of America.
During the SARS-CoV-2 pandemic, a need for methods to decontaminate and reuse personal protective equipment (PPE) and medical plastics became a priority. In this investigation we aimed to develop a contamination evaluation protocol for laboratory pipette tips, after decontamination. Decontamination methods tested in this study included cleaning with a common laboratory detergent (2.
View Article and Find Full Text PDFERJ Open Res
November 2024
National Heart and Lung Institute, Imperial College London, London, UK.
Background: Biomarkers that change in response to nintedanib in subjects with idiopathic pulmonary fibrosis (IPF) would be valuable. We investigated the effects of nintedanib on circulating biomarkers in subjects with IPF in the INMARK trial.
Methods: Subjects with IPF were randomised 1:2 to receive nintedanib 150 mg twice daily or placebo for 12 weeks, after which all patients received open-label nintedanib for 40 weeks.
J Colloid Interface Sci
March 2025
Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China. Electronic address:
The full utilization of lignocellulose involves two distinct catalytic routes: i) oxidative depolymerization of lignin and ii) acid/alkaline hydrolysis of hemicellulose and cellulose. To improve efficiency and reduce costs, constructing a single-cluster catalyst represents a desirable yet challenging strategy. Herein, triple-functional molecular polyoxometalates (POMs), NLLHVMoO (n = 1-6) were fabricated using N-lauroyl-l-lysine (NLL) and HVMoO as precursors.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
Despite advancements in nanomedicine for drug delivery, many drug-loaded nanoparticles reduce tumor sizes but often fail to prevent metastasis. Mesoporous silica nanoparticles (MSNs) have attracted attention as promising nanocarriers. Here, we demonstrated that MSN-PEG/TA 25, with proper surface modifications, exhibited unique antimetastatic properties.
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