Transcriptomic Analysis of Adult Mouse Cardiac Stromal Cells Using Single-Cell qRT-PCR.

Area of Science:

• Cardiovascular Biology
• Stem Cell Biology
• Regenerative Medicine

Background:

• Adult mammalian hearts were once considered post-mitotic, but studies suggest limited cardiomyocyte renewal.
• Cardiac stromal cells are explored for regenerative potential via paracrine signaling, though their identity is unclear.
• Existing methods for isolating cardiac stromal cells present challenges in yield and expansion time.

Purpose of the Study:

• To clarify the transcriptional identity and heterogeneity of adult mouse cardiac stromal cells.
• To develop and evaluate a novel collagenase-trypsin protocol for isolating cardiac stromal cells.
• To compare the novel protocol with the established cardiosphere-derived cell (CDC) isolation method.

Main Methods:

• Development of a novel cardiac collagenase-trypsin (CT) isolation protocol.
• Comparison of CT cells with cardiosphere-derived cells (CDCs) and cardiac fibroblasts (CFs).
• Single-cell quantitative reverse transcription PCR (qRT-PCR) for gene expression analysis.

Main Results:

• The CT protocol yielded higher cell numbers and required shorter expansion times.
• CT cells demonstrated superior survival under serum starvation compared to commercial CFs.
• CT cells and CDCs shared similar gene expression profiles, distinct from CFs, with CTs showing Tcf21 enrichment and lower Tbx5 expression.

Conclusions:

• CT cells closely resemble CDCs but are generated more rapidly.
• The novel CT protocol provides a robust and efficient source of paracrine-active cardiac stromal cells.
• Findings offer insights into the complex identity and heterogeneity of cardiac stromal cells.