Pulmonary surfactant-associated protein B regulates prostaglandin-endoperoxide synthase-2 and inflammation in chronic obstructive pulmonary disease

Optimization of resting tension for wire myography in male rat pulmonary arteries

Wire myography to test vasomotor functions of blood vessels ex-vivo are well-established for the systemic circulation, however, there is no consensus on protocols for pulmonary arteries. We created a standardized wire myography protocol for healthy rat PAs and validated this in a pulmonary hypertension (PH) model. Vessels stretched to higher initial tensions (5.0, 7.5 and 10.0 mN) exhibited a uniform response to phenylephrine, a larger dynamic range, and lower EC50 values. The endothelium-mediated relaxation showed that moderate tensions (7.5 and 10.0 mN) produced robust responses with higher maximum relaxation and lower EC50 values. For endothelium independent responses, the higher initial tension groups had lower and more consistent EC50 values than the lower initial tension groups. Pulmonary arteries from rats with PH were more responsive to vasoactive drugs when subjected to a higher initial tension. Notably, vessels in the PH group subjected to 15.0 mN exhibited high dynamic ranges in contractile and relaxation responses without tearing. Lastly, we observed attenuated cholinergic responses in these vessels-consistent with endothelial dysfunction in PH. Therefore, a moderate initial tension of 7.5-10.0 mN is optimal for healthy rat pulmonary arteries and a higher initial tension of 15.0 mN is optimal for pulmonary arteries from animals with PH.

Molecular Impact of Conventional and Electronic Cigarettes on Pulmonary Surfactant

The alveolar epithelium is covered by a non-cellular layer consisting of an aqueous hypophase topped by pulmonary surfactant, a lipo-protein mixture with surface-active properties. Exposure to cigarette smoke (CS) affects lung physiology and is linked to the development of several diseases. The macroscopic effects of CS are determined by several types of cell and molecular dysfunction, which, among other consequences, lead to surfactant alterations. The purpose of this review is to summarize the published studies aimed at uncovering the effects of CS on both the lipid and protein constituents of surfactant, discussing the molecular mechanisms involved in surfactant homeostasis that are altered by CS. Although surfactant homeostasis has been the topic of several studies and some molecular pathways can be deduced from an analysis of the literature, it remains evident that many aspects of the mechanisms of action of CS on surfactant homeostasis deserve further investigation.

LncRNA MEG3 ameliorates NiO nanoparticles-induced pulmonary inflammatory damage via suppressing the p38 mitogen activated protein kinases pathway

The lung inflammatory damage could result from the nickel oxide nanoparticles (NiO NPs), in which the underlying mechanism is still unclear. This article explored the roles of long noncoding RNA maternally expressed gene 3 (lncRNA MEG3) and p38 mitogen activated protein kinases (p38 MAPK) pathway in pulmonary inflammatory injury induced by NiO NPs. Wistar rats were treated with NiO NPs suspensions (0.015, 0.06, and 0.24 mg/kg) by intratracheal instillation twice-weekly for 9 weeks. Meanwhile, A549 cells were treated with NiO NPs suspensions (25, 50, and 100 μg/ml) for 24 h. It can be concluded that the NiO NPs did trigger pulmonary inflammatory damage, which was confirmed by the histopathological examination, abnormal changes of inflammatory cells and inflammatory cytokines (IL-1β, IL-6, TGF-β1, TNF-α, IFN-γ, IL-10, CXCL-1 and CXCL-2) in bronchoalveolar lavage fluid (BALF), pulmonary tissue and cell culture supernatant. Furthermore, NiO NPs activated the p38 MAPK pathway and downregulated MEG3 in vivo and in vitro. However, p38 MAPK pathway inhibitor (10 μM SB203580) reversed the alterations in the expression levels of inflammatory cytokines induced by NiO NPs. Meanwhile, over-expressed MEG3 significantly suppressed NiO NPs-induced p38 MAPK pathway activation and inflammatory cytokines changes. Overall, the above results proved that over-expression of lncRNA MEG3 reduced NiO NPs-induced inflammatory damage by preventing the activation of p38 MAPK pathway.