SGLT1 activity in lung alveolar cells of diabetic rats modulates airway surface liquid glucose concentration and bacterial proliferation

• Published in: Scientific reports 2016-02, Vol.6 (1), p.21752-21752, Article 21752
• Main Authors: Oliveira, Tales Lyra, Candeia-Medeiros, Návylla, Cavalcante-Araújo, Polliane M., Melo, Igor Santana, Fávaro-Pípi, Elaine, Fátima, Luciana Alves, Rocha, Antônio Augusto, Goulart, Luiz Ricardo, Machado, Ubiratan Fabres, Campos, Ruy R., Sabino-Silva, Robinson
• Format: Article
• Language: English
• Subjects: 14/1; 631/326/2522; 631/443/1784; 631/80/304; 631/80/313/2380; 82/51; 82/80; 96/95; Alloxan; Alveolar Epithelial Cells - drug effects; Alveolar Epithelial Cells - metabolism; Alveolar Epithelial Cells - microbiology; Alveoli; Animals; Bacteria; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - microbiology; Bronchodilator Agents - pharmacology; Bronchus; Colony Count, Microbial; Diabetes; Diabetes mellitus; Diabetes Mellitus, Experimental - chemically induced; Diabetes Mellitus, Experimental - complications; Diabetes Mellitus, Experimental - genetics; Diabetes Mellitus, Experimental - metabolism; Drug resistance; Gene Expression Regulation; Glucose; Glucose - metabolism; Health risks; Humanities and Social Sciences; Immunohistochemistry; Isoproterenol; Isoproterenol - pharmacology; Lung - drug effects; Lung - metabolism; Lung - microbiology; Lung - pathology; Lungs; Male; Methicillin; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - growth & development; multidisciplinary; Phlorhizin - pharmacology; Pneumonia, Bacterial - complications; Pneumonia, Bacterial - genetics; Pneumonia, Bacterial - metabolism; Pneumonia, Bacterial - pathology; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Pseudomonas Infections - complications; Pseudomonas Infections - genetics; Pseudomonas Infections - metabolism; Pseudomonas Infections - pathology; Rats; Rats, Wistar; Respiratory tract; Rodents; Science; Science (multidisciplinary); Sodium-Glucose Transporter 1 - agonists; Sodium-Glucose Transporter 1 - antagonists & inhibitors; Sodium-Glucose Transporter 1 - genetics; Sodium-Glucose Transporter 1 - metabolism; Staphylococcal Infections - complications; Staphylococcal Infections - genetics; Staphylococcal Infections - metabolism; Staphylococcal Infections - pathology; Staphylococcus aureus
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep21752

High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase SGLT1 activity) or phlorizin (to decrease SGLT1 activity); 2 hours later, glucose concentration and bacterial proliferation (methicillin-resistant Sthaphylococcus aureus , MRSA and Pseudomonas aeruginosa, P. aeruginosa ) were analyzed in bronchoalveolar lavage (BAL); and alveolar SGLT1 was analyzed by immunohistochemistry. BAL glucose concentration and bacterial proliferation increased in diabetic animals: isoproterenol stimulated SGLT1 migration to luminal membrane, and reduced (50%) the BAL glucose concentration; whereas phlorizin increased the BAL glucose concentration (100%). These regulations were accompanied by parallel changes of in vitro MRSA and P. aeruginosa proliferation in BAL (r = 0.9651 and r = 0.9613, respectively, Pearson correlation). The same regulations were observed in in vivo P. aeruginosa proliferation. In summary, the results indicate a relationship among SGLT1 activity, ASL glucose concentration and pulmonary bacterial proliferation. Besides, the study highlights that, in situations of pulmonary infection risk, such as in diabetic subjects, increased SGLT1 activity may prevent bacterial proliferation whereas decreased SGLT1 activity can exacerbate it.