Biomedicines (Dec 2022)

Analysis of Cerebral Small Vessel Changes in AD Model Mice

  • Abu Zaffar Shibly,
  • Abdullah Md. Sheikh,
  • Makoto Michikawa,
  • Shatera Tabassum,
  • Abul Kalam Azad,
  • Xiaojing Zhou,
  • Yuchi Zhang,
  • Shozo Yano,
  • Atsushi Nagai

DOI
https://doi.org/10.3390/biomedicines11010050
Journal volume & issue
Vol. 11, no. 1
p. 50

Abstract

Read online

Amyloid β (Aβ) peptide is deposited in the brains of sporadic Alzheimer’s disease (AD) due to impaired vessel-dependent clearance. To understand the mechanisms, we investigated time-dependent cerebrovascular changes in AD model mice. Cerebrovascular and other pathological changes were analyzed in AD model mice (J20 strain) aging from 2 to 9 months by immunostaining. At 2 months, Aβ was only intraneuronal, whereas vessels were positive from 3 months in J20 mice. Compared to wild-type (WT), vessel density was increased at 2 months but decreased at 9 months in J20 mice, claudin-5 levels were decreased, and vascular endothelial growth factor (VEGF) levels were increased in the cortex and hippocampus of J20 mice brain at all time points. Albumin extravasation was evident from 3 months in J20 brains. Collagen 4 was increased at 2 and 3 months. Aquaporin 4 was spread beyond the vessels starting from 3 months in J20, which was restricted around the vessel in wild-type mice. In conclusion, the study showed that an early decrease in claudin-5 was associated with VEGF expression, indicating dysfunction of the blood–brain barrier. Decreased claudin-5 might cause the leakage of blood constituents into the parenchyma that alters astrocyte polarity and its functions.

Keywords