Aquaporin-4 protein expression in normal canine brains

Area of Science:

• Neuroscience
• Veterinary Pathology
• Molecular Biology

Background:

• Aquaporin-4 (AQP4) is recognized for its role in cancer progression and therapy.
• No prior data existed on AQP4 expression in healthy canine brains.

Purpose of the Study:

• To confirm and characterize AQP4 presence and distribution in non-pathological canine brains using immunohistochemistry.
• To correlate AQP4 expression with astrocytes and investigate developmental influences.

Main Methods:

• Immunohistochemistry was performed on formalin-fixed, paraffin-embedded normal canine brain tissues (n=12).
• Glial fibrillary acidic protein (GFAP) was used to identify astrocytes and co-localize with AQP4.
• Expression patterns were analyzed across different brain regions, ages, and breeds.

Main Results:

• AQP4 was consistently found in astrocyte foot processes at subpial, perivascular, and periventricular surfaces.
• Most canine brains (9/12) showed AQP4 predominantly in white matter tracts.
• Younger dogs (≤3 months) exhibited diffuse AQP4 labeling in both grey and white matter, suggesting developmental influence.

Conclusions:

• This is the first study detailing AQP4 immunohistochemical distribution in normal canine brains.
• Canine AQP4 expression patterns are broadly similar to those observed in other species.
• Further research with larger cohorts is recommended to clarify the impact of breed and aging on AQP4 distribution.