Single-cell Transcriptomic Analysis Reveals the Cellular Heterogeneity of Mesenchymal Stem Cells

Area of Science:

• Cell Biology
• Immunology
• Stem Cell Research

Background:

• Mesenchymal stem cells (MSCs) are known to be heterogeneous, with varying capacities.
• The precise characteristics and functional distinctions within MSC populations remain largely undefined.

Purpose of the Study:

• To characterize the heterogeneity of ex vivo-expanded MSCs using single-cell RNA sequencing.
• To identify distinct MSC subpopulations and map their developmental trajectories and functional roles.

Main Methods:

• Single-cell RNA sequencing was performed on 61,296 MSCs from bone marrow and Wharton's jelly.
• Developmental trajectories were mapped to reveal differentiation pathways.
• Functional assays were conducted to assess immunomodulatory capacity.

Main Results:

• Five distinct MSC subpopulations were identified, including stem-like active proliferative cells (APCs) and prechondrocytes.
• APCs showed strong proliferation and stemness signatures, expressing perivascular mesodermal progenitor markers.
• Prechondrocytes expressed immunomodulatory genes and suppressed T cell proliferation in vitro.

Conclusions:

• MSC heterogeneity comprises distinct subpopulations with specialized functions.
• Two key subpopulations were identified: one for self-renewal (APCs) and another for immunoregulation (prechondrocytes).
• Purifying these functional subpopulations could lead to more specific and effective MSC-based therapies.