Developmental expression patterns for angiotensin receptors in mouse skin and brain

Area of Science:

• Cardiovascular Physiology
• Developmental Biology
• Molecular Endocrinology

Background:

• Angiotensin II (Ang II) effects are mediated by G-protein-coupled receptors, primarily AT1R and AT2R.
• Conventional understanding posits AT2R is abundant in fetuses and scarce in adults.
• Recent studies challenge this notion, suggesting a developmental increase in AT2R in various organs.

Purpose of the Study:

• To investigate the developmental expression profile of AT1R and AT2R in mouse skin and brainstem.
• To test the hypothesis that skin exhibits an inverse AT2R ontogeny compared to other organs.

Main Methods:

• Western blot analysis to quantify AT1R and AT2R protein levels in fetal and adult mouse skin and brainstem.
• Immunofluorescence to confirm protein expression patterns.
• Real-time RT-PCR to assess AT1R and AT2R mRNA levels in skin and brainstem.

Main Results:

• Brainstem showed lower AT2R and higher AT1R in fetuses compared to adults.
• Skin exhibited higher AT2R and lower AT1R in fetuses compared to adults.
• mRNA analysis corroborated protein findings, with skin showing higher AT2R and lower AT1R mRNA in fetuses.

Conclusions:

• The developmental expression of angiotensin receptors differs significantly between skin and other organs like the brainstem.
• Adults generally express higher AT2R protein than fetuses in organs outside the skin.
• The traditional view of AT2R maturation is likely only applicable to skin.