The role of caveolin-1 in pulmonary matrix remodeling and mechanical properties
AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY
Authors: Le Saux, O.; Teeters, K.; Miyasato, S.; Choi, J.; Nakamatsu, G.; Richardson, J. A.; Starcher, B.; Davis, E. C.; Tam, E. K.; Saux, C. Jourdan-Le
Caveolin-1 (cav1) is a 22-kDa membrane protein essential to the formation of small invaginations in the plasma membrane, called caveolae. The cav1 gene is expressed primarily in adherent cells such as endothelial and smooth muscle cells and fibroblasts. Caveolae contain a variety of signaling receptors, and cav1 notably downregulates transforming growth factor (TGF)-beta signal transduction. In pulmonary pathologies such as interstitial fibrosis or emphysema, altered mechanical properties of the lungs are often associated with abnormal ECM deposition. In this study, we examined the physiological functions and the deposition of ECM in cav1(-/-) mice at various ages (1-12 mo). Cav1(-/-) mice lack caveolae and by 3 mo of age have significant reduced lung compliance and increased elastance and airway resistance. Pulmonary extravasation of fluid, as part of the cav1(-/-) mouse phenotype, probably contributed to the alteration of compliance, which was compounded by a progressive increase in deposition of collagen fibrils in airways and parenchyma. We also found that the increased elastance was caused by abundant elastic fiber deposition primarily around airways in cav1(-/-) mice at least 3 mo old. These observed changes in the ECM composition probably also contribute to the increased airway resistance. The higher deposition of collagen and elastic fibers was associated with increased tropoelastin and col1 alpha 2 and col3 alpha 1 gene expression in lung tissues, which correlated tightly with increased TGF-beta/Smad signal transduction. Our study illustrates that perturbation of cav1 function may contribute to several pulmonary pathologies as the result of the important role played by cav1, as part of the TGF-beta signaling pathway, in the regulation of the pulmonary ECM.
Cobalt oxide nanoparticles by solid-state thermal decomposition: Synthesis and characterization
EURASIAN CHEMICAL COMMUNICATION
Authors: Khalaji, Aliakbar Dehno
In this study, mononuclear octahedral cobalt(III) Schiff base complex [CoL3], L =(5-bromo-2-hydroxybenzyl-2-furylmethyl)imine was synthesized from the reaction of Co(NO3)(2)center dot 6H(2)O and the Schiff base ligand L in methanol as solvent and characterized by elemental analyes (CHN) and FT-IR spectroscopy. It was used as a new precursor to prepare spinel type cobalt oxide nanoparticles by a facile solid-state thermal decomposition. Controlling the temperature and time, Co3O4 nanoparticles were obtained in air at 550 degrees C within 3.5 h. The Co3O4 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results confirm that the resulting cobalt oxide were prepared during pure single-phases. Using the present method, Co3O4 nanoparticles can be produced without using expensive organic solvent and complicated equipment. TEM result showed that the products are almost flat with the size of about 10-50 nm. It has potential to be applied as a general method for preparation of other transition metal oxide nanoparticles.