Isolation and characterization of equine native MSC populations

Area of Science:

• Veterinary Regenerative Medicine
• Stem Cell Biology
• Equine Therapeutics

Background:

• Mesenchymal stem/stromal cells (MSCs) are used therapeutically in horses, a valuable preclinical model for humans.
• The origin of equine MSCs remains unestablished, hindering the isolation of defined cell populations.
• Human MSCs originate from perivascular CD146+ (pericytes) and CD34+ (adventitial) cells.

Purpose of the Study:

• To identify and characterize equine CD34+ and CD146+ perivascular cell populations.
• To compare the properties and differentiation potential of these isolated equine cell populations.
• To investigate the angiogenic capacity of equine CD146+ and CD34+ cells.

Main Methods:

• Immunohistochemistry to localize CD34+ and CD146+ cells in equine tissues.
• Fluorescence-activated cell sorting (FACS) to isolate CD34+ and CD146+ cell fractions from equine adipose tissue.
• Analysis of MSC marker expression, trilineage differentiation capacity, and in vivo angiogenic properties (CAM assay).

Main Results:

• Both CD34+ and CD146+ cells exhibited MSC characteristics, including adherence, clonal growth, marker expression, and trilineage differentiation.
• CD146+ cells demonstrated significantly higher angiogenic properties compared to CD34+ cells.
• Elevated VEGFA and ANGPT1 expression in CD146+ cells correlated with their enhanced angiogenic potential.

Conclusions:

• This study successfully isolated and cultured equine CD34+ and CD146+ cell populations for the first time.
• Both cell types possess MSC-like phenotypes, with CD146+ cells showing distinct angiogenic capabilities.
• Equine CD146+ cells represent a promising source for advanced regenerative therapies due to their angiogenic potential.