Assessment of Leukocyte-Platelet Aggregates in Animal Models of Stroke

Ischemic stroke and reperfusion are associated with an inflammatory response characterized in part by the formation of leukocyte-platelet aggregates (LPAs). Aggregate formation may enhance the immune and hemostatic functions of both cell types, thereby exacerbating reperfusion injury after ischemic stroke. The formation of LPAs in peripheral blood may also serve as a biomarker of injury severity. Using in vivo fluorescence microscopy in an animal model of focal ischemic stroke, researchers directly observed LPAs adhering to the cerebral microcirculation in response to systemic blood activation or ischemic events. LPA formation may be a useful biomarker and potential therapeutic target after ischemic stroke and reperfusion.

Fig. 1. Methods to investigate leukocyte-platelet-aggregate formation. (Finsterbusch et al., 2018)

Our LPA Assessment Service in Animal Models of Stroke

Ace Therapeutics can measure LPAs in animal stroke models in different (pathologic) physiological settings. Our professional staff provides comprehensive assistance in experimental design, animal study protocols, animal handling, in vivo imaging, and data analysis.

We offer a range of tools to monitor leukocyte and platelet adhesion after ischemia and reperfusion. Here you can obtain information on the location of LPAs within brain tissue, the dynamics of their interactions and/or dynamic changes in leukocyte and platelet behavior.

Flow Cytometry-Based LPA Assessment

We can quantify circulating LPAs in the blood of stroke animals and investigate the expression of related molecules by conventional flow cytometry (CFC).

Sample	Small amount (~ 5 μL) of whole blood
Advantages and Features	Rapid measurement, high sensitivity, high assay precision, one-step assay Allows quantification of LPAs and their subsets In vitro analysis
Markers	CD45 (pan-leukocyte marker), Ly6G (neutrophil marker), CD11b (marker for cells other than lymphocytes), and CD41 (pan-platelet marker).
Display of Results	The amounts of LPAs can be displayed as the percentage of leukocytes (or their subsets) bound to platelets or as the percentage of platelet aggregates containing leukocytes.

We also offer imaging flow cytometry (IFC) to determine LPAs. LPAs allow for a more efficient differentiation between platelets and leukocytes in close proximity than CFC. More importantly, IFC enables higher throughput without significantly over-detecting LPAs.

Light Microscopy-Based LPA Assessment

We use light microscopy to assess LPAs quantitatively and qualitatively in brain tissues of stroke animals.

Samples	Brain tissue sections
Advantages and Features	2D or 3D analysis Ex vivo analysis Showing the location of LPAs in the tissue

Intravital Microscopy-Based LPA Assessment

We offer stroke researchers the opportunity to perform high-resolution imaging of the real-time dynamics of platelet-leukocyte interactions in live animal models. Our state-of-the-art microscopy facilities and microscopes are accessible to the region of interest.

Samples	Live animals
Advantages and Features	Real-time analysis in 2D or 3D In vitro analysis LPAs within brain's superficial regions

Applications of LPA Assessment Service in Animal Models of Stroke

Investigate the impact of platelet-leukocyte interactions
Analyze the potential of LPAs as therapeutic targets for stroke treatment

LPAs are particularly sensitive parameters reflecting the process of thrombosis and inflammation after stroke. Ace Therapeutics's LPA measurement service can provide an attractive and easy-to-use prognostic and/or diagnostic tool for preclinical stroke research. If you are interested in our services, please do not hesitate to contact us!

Reference

Finsterbusch, M., et al. (2018). Measuring and interpreting platelet-leukocyte aggregates. Platelets, 29(7), 677-685.

All of our services are intended for preclinical research use only and cannot be used to diagnose, treat or manage patients.