Cardiovascular scaling between humans and mice during postnatal development

Area of Science:

• Cardiovascular Biology
• Developmental Biology
• Translational Medicine

Background:

• Accurate age matching between human and mouse models is crucial for translating research findings, especially in developmental studies.
• Tissue-specific variations in developmental timelines across species complicate age equivalence, particularly before maturity.

Purpose of the Study:

• To develop a cardiovascular-specific age equivalence mapping between humans and mice.
• To establish a framework for selecting appropriate mouse ages in studies of normal cardiovascular development and pediatric cardiovascular diseases.

Main Methods:

• Compiled and mathematically modeled cardiovascular anatomical, functional, and biomechanical data from postnatal development studies.
• Determined optimal age scale factors to align human and mouse developmental time courses for various cardiovascular variables.

Main Results:

• An overall optimal age scale factor of 0.69 mouse weeks per human year was identified, with individual optima ranging from 0.4 to 1.3 wk/yr.
• No single universal scaling factor can fully align all developmental timelines due to species-specific variations.
• Some cardiovascular variables, like heart rate and aortic wall shear stress, show qualitatively different time courses and cannot be aligned by scaling.

Conclusions:

• Variable-specific age scaling factors are recommended for studies focusing on particular tissues and loading conditions.
• The identified age scale factors enhance the translational relevance and interpretation of findings from mouse models of cardiovascular development.
• Limitations exist, as not all developmental trajectories can be perfectly aligned, necessitating careful consideration of the chosen scaling factors.