Quantitative detection of thrombin activity in an ischemic stroke model

Area of Science:

• Neuroscience
• Biochemistry
• Cardiovascular Research

Background:

• Thrombin plays a key role in thrombogenesis and impacts brain cells via protease-activated receptors.
• While low thrombin activity is neuroprotective, higher levels are detrimental to brain tissue.

Purpose of the Study:

• To develop and validate a novel method for the direct quantitative measurement of thrombin activity in brain slices following ischemic stroke.
• To investigate the correlation between thrombin activity and infarct volume in a stroke model.

Main Methods:

• Quantitative measurement of thrombin activity using a fluorescent substrate on fresh coronal brain slices.
• Specific inhibition of prolyl endopeptidase and aminopeptidases to ensure assay specificity for thrombin.
• Assessment of infarct volume using 2,3,5-triphenyltetrazolium chloride (TTC) staining.

Main Results:

• Significantly higher thrombin activity was observed in the ischemic hemisphere compared to the contralateral hemisphere (p < 0.05).
• Thrombin levels in both hemispheres of stroke mice were elevated compared to healthy controls and exceeded protective ranges.
• A significant positive correlation was found between thrombin activity in the ischemic hemisphere and the resulting infarct volume.

Conclusions:

• The developed method allows for specific and quantitative measurement of thrombin activity in brain slices post-stroke.
• Elevated thrombin activity in the ischemic brain region is associated with stroke severity and infarct size.
• These findings support the potential for developing thrombin-targeted therapies for stroke treatment.