lactoferrin and Pulmonary-Edema

Lactoferrin (LF) plays various anti-inflammatory roles in inflammation experimentally induced by lipopolysaccharides (LPS). But the protective effects of LF on LPS-induced acute lung injury (ALI) have not been elucidated. In this study, we aimed to study the effects of LF on ALI caused by LPS in mice. At 1h before or after LPS injection, an intraperitoneal injection of LF (5mg/body) was administered. Lung specimens and the bronchoalveolar lavage fluid (BALF) were isolated for histopathological examinations and biochemical analyses 12h after LPS exposure. We found that both prophylactic and therapeutic administration of LF significantly decreased the W/D ratio of the lung and protein concentration in the BALF. LF significantly reduced the pulmonary myeloperoxidase activity and the number of total cells in the BALF 12h after LPS challenge. LF treatment markedly attenuated lung edema, alveolar hemorrhage and inflammatory cells infiltration. Moreover, LF also decreased the production of TNF-α and increased interleukin-10 in the BALF. These results firstly indicate that LF may protect against LPS-induced ALI in mice.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Bronchoalveolar Lavage Fluid; Hemorrhage; Interleukin-10; Lactoferrin; Lipopolysaccharides; Lung; Male; Mice; Neutrophils; Peroxidase; Pulmonary Edema; Tumor Necrosis Factor-alpha

Bronchopulmonary dysplasia (BPD) is characterized by simplified alveolarization and arrested vascular development of the lung with associated evidence of endothelial dysfunction, inflammation, increased oxidative damage, and iron deposition. Heme oxygenase-1 (HO-1) has been reported to be protective in the pathogenesis of diseases of inflammatory and oxidative etiology. Because HO-1 is involved in the response to oxidative stress produced by hyperoxia and is critical for cellular heme and iron homeostasis, it could play a protective role in BPD. Therefore, we investigated the effect of HO-1 in hyperoxia-induced lung injury using a neonatal transgenic mouse model with constitutive lung-specific HO-1 overexpression. Hyperoxia triggered an increase in pulmonary inflammation, arterial remodeling, and right ventricular hypertrophy that was attenuated by HO-1 overexpression. In addition, hyperoxia led to pulmonary edema, hemosiderosis, and a decrease in blood vessel number, all of which were markedly improved in HO-1 overexpressing mice. The protective vascular response may be mediated at least in part by carbon monoxide, due to its anti-inflammatory, antiproliferative, and antiapoptotic properties. HO-1 overexpression, however, did not prevent alveolar simplification nor altered the levels of ferritin and lactoferrin, proteins involved in iron binding and transport. Thus the protective mechanisms elicited by HO-1 overexpression primarily preserve vascular growth and barrier function through iron-independent, antioxidant, and anti-inflammatory pathways.

Topics: Animals; Animals, Newborn; Bronchopulmonary Dysplasia; Disease Models, Animal; Ferritins; Heme Oxygenase-1; Hemosiderosis; Humans; Infant, Newborn; Iron; Lactoferrin; Lung; Mice; Mice, Transgenic; Oxygen; Pulmonary Edema