Factor XIIIa as a nerve-associated transglutaminase

Area of Science:

• Neuroscience
• Hematology
• Biochemistry

Background:

• Nerve recovery traditionally overlooked the role of blood-derived factors.
• Injured tissues, including nerves, require blood-derived cells and factors for optimal healing.
• Factor XIIIa (FXIIIa) is known for its role in stabilizing fibrin clots during blood coagulation.

Purpose of the Study:

• To investigate the presence and role of FXIIIa in nervous tissue healing.
• To explore the potential link between blood coagulation and nerve regeneration.
• To compare FXIIIa activity and expression in different species and nervous system compartments.

Main Methods:

• Immunological cross-reactivity assays to identify transglutaminase forms.
• Enzyme activity assays in plasma from fish and mammals.
• Analysis of FXIIIa expression in mammalian neural tissues post-injury.
• Comparative analysis of FXIIIa behavior in regenerating peripheral and central nervous systems.

Main Results:

• A 55 kDa transglutaminase, cross-reactive with mammalian FXIIIa's a-subunit, was found in fish plasma, macrophages, and nerves.
• Unlike mammalian FXIIIa, the fish plasma enzyme was active, suggesting species-specific coagulation control.
• Mammalian peripheral nerves showed higher FXIIIa levels than central nervous system nerves post-injury.
• FXIIIa exhibited similar post-injury behavior in regenerating mammalian peripheral nerves and fish central nervous system.

Conclusions:

• FXIIIa is present and active in the nervous system, suggesting a role beyond blood coagulation.
• The level of FXIIIa post-nerve injury may correlate with the tissue's regenerative capacity.
• FXIIIa may represent a molecular link between blood coagulation processes and nerve healing mechanisms.