Intrauterine Malnutrition Reduced Long Leptin Receptor Isoform Expression and Proinflammatory Cytokine Production in Male Rat Pulmonary Endothelial Cells Stimulated by Lipopolysaccharide

Abstract

Background/Aims We have previously shown that low birth weight (LBW) rats exposed to intrauterine malnutrition have an impaired lung inflammatory response and reduced levels of inflammatory mediators; however, circulating leptin levels were not increased. We evaluated long leptin receptor isoform (ObRb) expression in lung endothelial cells from low birth weight rats and examined its role in the production of lipid mediators and cytokines. Methods Lung endothelial cells were obtained from normal birth weight (NBW) rats or LBW rats subjected to intrauterine malnutrition. These cells were stimulated with leptin (10 ng/mL), LPS (lipopolysaccharide, 1 μg/mL), or leptin plus LPS. Six hours after stimulation, the production of inflammatory mediators (PGE2, LTB4, IL-1β, and IL-6) was evaluated using commercial ELISA kits, and Western blotting was performed to investigate p38MAPK, NF-κB, and ObRb expression. Results Leptin increased IL-1β levels in only cells from the NBW group, whereas LPS increased PGE2 and LTB4 levels in cells from both groups; leptin addition potentiated lipid mediator production induced by LPS in the NBW group. LPS enhanced the production of IL-1β and IL-6 in only endothelial cells from NBW rats. Leptin receptor expression was decreased (63%) in endothelial cells from LBW rats. None of the stimuli increased NF-κB or p38 signaling pathway expression in cells from LBW rats. Conclusion These results suggest that intrauterine malnutrition compromises leptin receptor expression and cytokine production in pulmonary endothelial cells stimulated by LPS; these effects seem to involve the NF-κB and p38MAPK signaling pathways.

Nitric Oxide Balance in Health and Diseases: Implications for New Treatment Strategies

“…The lung is composed of numerous cell types, such as macrophages, epithelial cells, endothelial cells, vascular smooth muscle cells, bronchial smooth muscle cells, neurons, and pneumocytes [47]. Each cell type produces NO through one or more isoforms of NOS [48].…”

“…Hence, it is reasonable to claim that NOS isoforms expression and the NO effects are dependent on enzyme compartmentalization, cell localization in the organ, and also the developmental timing of enzyme expression. An example of changes from different NOS compartmentalization is that a change in the hepatic blood circulation during endotoxic shock has been found to be anti-parallel to those observed in the lungs [47].…”