Abstract
Purpose:Myeloperoxidase(MPO) has been found to be the mediator in various
inflammatory diseases. Bacterial infection of the intestine and hypoxia
can both lead to inflammatory responses, but the effects of MPO in these
phenomena are still unclear.
Methods: By building the MPO-/- mice
,we examined relevant inflammatory factors and tissue damage in mice
with intestinal Citrobacter rodentium infection and hypoxia. The
body weight and excreted microorganisms were monitored. Intestinal
tissues were collected 7 days after bacterial infection under hypoxia to
undergo HE staining and assess the degree of pathological damage. The
levels of TNF-α, IFN-γ, IL-6 and IL-1β inflammatory factors in the serum
were quantified using ELISA. PCR, WB and IF assays to determine the
expression of chemokines MCP1, MIP2 and KC in the colon and spleen. .
Results: Citrobacter rodentium infection and
hypoxia caused weight loss , intestinal colitis and splenic inflammatory
cells active proliferation in wild type mice and this phenomena was
alleviative in MPO-/- mice. Also,the capability of
clearing bacteria in MPO-/- mice significantly
declined. The level of TNF-α in the serum and spleen was both lower in
MPO-/- hypoxia C. rodentium -infected mice than
that in wild type mice. The chemokines expression levels of MIP2, KC and
MCP1 in the spleen and colon of each bacterial infected group were
significantly increased (P <0.05), while in hypoxia, the
factors in the spleen and colon were decreased
(P <0.05). Meanwhile, The levels of these chemokines in
the MPO-/- mice were found to be lower than those observed in the wild
type mice.
Conclusion: MPO plays an important role of the
inflammatory responses in infectious enteritis and hypoxia in mice. Loss
of MPO may greatly reduces the body’s inflammatory responses to fight
deseases.
Keywords: Hypoxia, Colitis, Inflammatory responses , MPO