Controlled hypertension induces cerebrovascular and gene alterations in Cyp1a1-Ren2 transgenic rats

Area of Science:

• Neuroscience
• Cardiovascular Science
• Pathology

Background:

• Hypertension is a key risk factor for cerebrovascular diseases, including dementia.
• The precise mechanisms linking hypertension to small vessel disease remain incompletely understood.

Purpose of the Study:

• To investigate cerebrovascular changes in response to controlled hypertension of varying durations (4 or 6 months).
• To utilize an inducible transgenic rat model (Cyp1a1-Ren2) for controlled hypertension studies.

Main Methods:

• Inducible transgenic rats (Cyp1a1-Ren2) were subjected to controlled hypertension for 4 or 6 months.
• Normotensive littermate controls were used for comparison.
• Vascular dimensions, protein levels (claudin-5, eNOS), microglial activation, and global gene expression (microarray) were analyzed.

Main Results:

• Six months of hypertension led to reduced vascular width and increased claudin-5 protein levels.
• Hypertension was associated with increased microglial activation, preceded by elevated eNOS expression.
• Microarray analysis revealed alterations in genes related to growth factors.

Conclusions:

• Modest, sustained hypertension is sufficient to induce significant cerebrovascular alterations.
• Endothelial dysfunction and neuroinflammation are key consequences of sustained hypertension.
• Altered growth factor expression suggests a potential mechanistic role in hypertension-induced vascular changes.