Besides its role as a
thrombolytic agent,
tissue plasminogen activator (tPA) triggers harmful effects in the brain parenchyma after
stroke, such as
inflammation, excitotoxicity and basal lamina degradation.
Neuroserpin, a natural inhibitor of tPA, has shown
neuroprotective effects in animal models of
brain infarct. However, the molecular mechanisms of
neuroserpin-mediated neuroprotection after
brain ischemia remain to be well characterized. Then, our aim was to investigate such mechanisms in primary mixed cortical cell cultures after
oxygen and
glucose deprivation (OGD). Primary rat mixed cortical cultures containing both astrocytes and neurons were subjected to OGD for 150min and subsequently treated with either tPA (5μg/mL),
neuroserpin (0.125, 0.25, 0.5 or 1μM), and tPA together with
neuroserpin at the mentioned doses. Twenty-four hours
after treatment, LDH release,
caspase-3 activity, MCP-1, MIP-2, active MMP-9, GRO/KC and COX-2 were measured. Statistical differences were analyzed using Student's t-test or one-way ANOVA as appropriate. Treatment with tPA after OGD increased LDH release, active MMP-9, MCP-1 and MIP-2 (all p≤0.05), but not
caspase-3, GRO/KC or COX-2 compared to control. Treatment with
neuroserpin after OGD decreased LDH release and active MMP-9 (all p≤0.05). It had no effect on
caspase-3 activity, or on MCP-1, MIP-2, GRO/KC or COX-2 expression compared to control. Administration of tPA together with
neuroserpin decreased LDH release, active MMP-9 and MIP-2 (all p≤0.05) and showed no effect on MCP-1, GRO/KC or COX-2 compared to control. Our results suggest that neuroprotective activity of
neuroserpin involves attenuation on tPA-mediated mechanisms of
inflammation and BBB disruption after
brain ischemia.