Anti-Inflammatory Effects of the Iron Chelator, DIBI, in Experimental Acute Lung Injury.

Iron plays a critical role in the immune response to inflammation and infection due to its role in the catalysis of reactive oxygen species (ROS) through the Haber-Weiss and Fenton reactions. However, ROS overproduction can be harmful and damage healthy cells. Therefore, iron chelation represents an innovative pharmacological approach to limit excess ROS formation and the related pro-inflammatory mediator cascades. The present study was designed to investigate the impact of the iron chelator, DIBI, in an experimental model of LPS-induced acute lung injury (ALI). DIBI was administered intraperitoneally in the early and later stages of lung inflammation as determined by histopathological evaluation. We found that lung tissues showed significant injury, as well as increased NF-κB p65 activation and significantly elevated levels of various inflammatory mediators (LIX, CXCL2, CCL5, CXCL10, IL-1𝛽, IL-6) 4 h post ALI induction by LPS. Mice treated with DIBI (80 mg/kg) in the early stages (0 to 2 h) after LPS administration demonstrated a significant reduction of the histopathological damage score, reduced levels of NF-κB p65 activation, and reduced levels of inflammatory mediators. Intravital microscopy of the pulmonary microcirculation also showed a reduced number of adhering leukocytes and improved capillary perfusion with DIBI administration. Our findings support the conclusion that the iron chelator, DIBI, has beneficial anti-inflammatory effects in experimental ALI.

Intravital Imaging of Pulmonary Immune Response in Inflammation and Infection.

Intravital microscopy (IVM) is a unique imaging method providing insights in cellular functions and interactions in real-time, without the need for tissue extraction from the body. IVM of the lungs has specific challenges such as restricted organ accessibility, respiratory movements, and limited penetration depth. Various surgical approaches and microscopic setups have been adapted in order to overcome these challenges. Among others, these include the development of suction stabilized lung windows and the use of more advanced optical techniques. Consequently, lung IVM has uncovered mechanisms of leukocyte recruitment and function in several models of pulmonary inflammation and infection. This review focuses on bacterial pneumonia, aspiration pneumonia, sepsis-induced acute lung Injury, and cystic fibrosis, as examples of lung inflammation and infection. In addition, critical details of intravital imaging techniques of the lungs are discussed.

Atorvastatin protected from paraquat-induced cytotoxicity in alveolar macrophages via down-regulation of TLR-4.

The current study designed to clarify the mechanism of paraquat-induced cytotoxicity and protective effects of Atorvastatin on freshly isolated alveolar macrophages (AMs). AMs were collected via bronchoalveolar lavage and exposed to various concentrations of paraquat in the presence and absence of atorvastatin for 24h. Cell viability, myeloperoxidase activity; nitric oxide generation and total antioxidant capacity were assessed. Expression of TLR-4 at mRNA and protein levels were studied by using PCR and western blot methods Atorvastatin enhanced the paraquat-reduced cell viability and reduced the paraquat-induced myeloperoxidase activity and nitric oxide production. Moreover, atorvastatin down-regulated by 60% the paraquat up-regulated expression of TLR-4 at protein and mRNA level. Our results suggest that, AMs in vitro model could be a novel cytological tool for studies on paraquat poisoning and therapy regimens. Additionally, atorvastatin cytoprotective effects on paraquat-induced cytotoxicity partly attribute to its anti-myeloperoxidase, antioxidant properties, which might be regulated via TLR-4 expression.

The role of sera from equine grass sickness on apoptosis induction in PC12 Tet-off p53 cell line.

The pathogenesis of equine grass sickness (EGS) has not fully understood. A better understanding of the exact pathogenesis of diseases can help to make an accurate diagnosis. Previous studies reported some pathological damage of neuronal cells in EGS patients. In this study, primarily cytotoxicity of serum from three clinically EGS-diagnosed horses on PC12 Tet-off (PTO) cells was assessed. Subsequently, the apoptotic tests including cytochrome C release, caspase-3/7 activity measurement and DNA fragmentation assay were conducted to clarify the apoptotic effect of serum from EGS patients. Addition of serum from EGS patients at concentrations higher than 25% on PTO cells resulted in a significant cytotoxicity in Alamar blue reduction assay compared with serum from healthy horses. All three apoptotic endpoints showed that the serum from EGS patients does have capability to induce apoptosis. A remarkable up regulation of cytochrome C release accompanied with concentration- and time-dependent augmentation in caspase-3/7 activity and ultimately DNA fragmentation were observed. Our data suggest that serum from EGS patients might have potentially neurotoxic compounds, which exerts cytotoxic and apoptotic effects on neuronal cells. Moreover, the EGS serum-induced apoptosis attributes to augmentation of cytochrome C release and caspase-3/7 activity.