THE ROLE OF IRON CHELATION IN PULMONARY INFLAMMATION
Abstract
Iron plays a critical role in the human body, e.g., in hemoglobin and DNA synthesis, but
it is also important in the regulation of the immune response. Iron’s role in the immune
system is closely related to the catalysis of reactive oxygen species (ROS). ROS are
needed to fight pathogens, but overproduction of ROS can kill healthy cells. Therefore,
therapeutic iron chelation is a potential pharmacological approach to limit ROS formation
and pro-inflammatory mediator release. The present research has been designed to study
the impact of iron chelation by a novel, highly specific, synthetic iron chelator DIBI in an
experimental model of lung inflammation in C57Bl/6 mice. First, we established a rodent
lung inflammation model using intranasal instillation of LPS from Pseudomonas
aeruginosa at different observation time points. The lung immune response was
evaluated by histological analysis of lung tissue, NF-kB activation, and measurement of
inflammatory cytokines and chemokines levels in plasma and lung tissues. Second, to
assess the anti-inflammatory properties of DIBI, we administered DIBI intraperitoneally
in the early and later stages of lung inflammation. We found that lung tissues showed
significant histological injury and increased NF-𝜅B P65 activation, 4 hours post LPS
administration at a sublethal dosage (5 mg/kg). We also measured a significant elevation
of LIX, CXCL2, CCL5, CXCL10, IL-1𝛽, IL-6, and CXCL1 in the lung and CXCL2,
CCL5, CXCL10, IL-6 and CXCL1 in the plasma relative to their respective control
groups. Mice treated with DIBI (80 mg/kg) intraperitoneally in early stages (0 and 2
hours) after LPS-induced lung inflammation demonstrated a significant reduction of
histopathological signs, reduced NF-𝜅B P65 activation, and reduced levels of
inflammatory mediators. Our data support the conclusion that LIX, CXCL2 (MIP-2),
CCL5, CXCL10 (IP-10), IL-1𝛽, IL-6, and CXCL1 (KC) play essential roles in our LPSinduced
lung inflammation model. Moreover, we can conclude that DIBI administration
represents a potential alternative treatment for pulmonary inflammation.