Evaluation of angiogenesis and microvascular remodeling in the subventricular zone of the brain of mice with experimental Alzheimer’s disease

Abstract

BACKGROUND: Under the influence of external factors (learning), processes of microvasculature remodeling occur in the neurogenic niche to meet the metabolic needs of activated cells. However, it remains unclear how these mechanisms of brain plasticity are disrupted during neurodegeneration.
 AIM: To study the expression features of markers of angiogenesis and microvascular remodeling in the subventricular zone of the brain during training of animals, including against the background of the development of Alzheimer’s-type neurodegeneration in them.
 MATERIAL AND METHODS: The studies were carried out on C57BL/6 mice at the age of 8 months. Modeling of Alzheimer’s disease was carried out by intrahippocampal injection of 2 μl of a 1 mM solution of β-amyloid Aβ25-35. To assess cognitive deficits, a conditioned passive avoidance test using an aversive stimulus was used. The expression of LC3B, ZO1, VEGFR2, VEGFR3, CD146, ICAM2, Dll4, Tie2 in the subventricular zone per 100 DAPI-positive cells was assessed. The test results were processed using one-way ANOVA and Fisher's test, the Mann–Whitney U test, the results were considered significant at p 0.05.
 RESULTS: On the 9th day after the administration of β-amyloid, before the application of the aversive stimulus, an increase in the expression level of LC3 (7.95±5.83%, p=0.045), CD146 (18.35±0.01%, p=0.045) was recorded, as well as VEGFR3 (17.13±5.05%, p=0.045), which continued to increase after the presentation of the stimulus (26.61±0.01%, p=0.045). By the beginning of registration of cognitive impairment (38th day of the experiment), the expression level of VEGFR2 (20.61±2.8%, p=0.045) and ICAM2 (126.61±41.28%, p=0.045) increased, the content of Dll4 (29.66±8.72%, p=0.045) and Tie2 (36.39±7.8%, p=0.045) decreased in animals with experimental Alzheimer’s disease.
 CONCLUSION: An aversive stimulus stimulates microvascular remodeling mechanisms in the subventricular zone of the animal’s brain, but when exposed to β-amyloid, these processes are significantly disrupted.