Molecular Analysis of Long-Term Cultured Cardiac Stem Cells for Cardiac Regeneration

Abstract

KeywordsCardiac stem cell • Myocyte • Regeneration • c-Kit • IGF-1 A c-Kit (CD117) is a well-known cell surface marker for adult somatic stem cells. We harvested c-Kit-positive cardiac stem cells (CSCs) from adult rat hearts by performing magnetic-activated cell sorting (MACS) and subjected them to longterm bulk culture more than 40 times. We made 11 attempts to obtain c-Kit-positive cells from adult (6-8-month-old) rats. Our initial expectation was of obtaining cells with homogenous cardiac phenotypes. However, each CSC bulk culture expressed varying degrees of the genes and cell surface markers belonging to cardiac and other mesenchymal lineages. The results suggested that these CSCs retained multiple developmental potential to some extent. Consequently, we investigated these CSCs in detail, hoping to establish the regeneration method by using c-Kit-positive cardiac cells [1][2][3][4][5][6][7][8][9][10][11][12].• CSC-21E maintained the cell shape, yielding spherical aggregates under a culture condition. The aggregate shape did not facilitate cell adherence to the dish surface. Interestingly, the proteomic analysis of these two morphological statuses revealed the drastic change of the protein profiles with the spherical aggregates showing protein profiles characteristic of stem cells and the flat cells

Cardiac regenerative therapy: Many paths to repair

“…Various studies demonstrating cardiac c-Kit expression and activity in non-stem cell populations [28,38,42,59] including myocytes, substantiate heterogeneity within the cardiac c-Kit + cell population and re-focus the discussion on what defines a stem cell beyond surface selection markers [110,111] . Indeed, recent studies demonstrating upregulation of c-Kit expression in "dedifferentiating" adult mammalian cardiomyocytes suggest a somewhat fluid relationship between stemness, post-mitotic commitment and stem cell marker expression [112][113][114][115] echoing but not equivalent to lower vertebrate or mammalian neonatal myocardial plasticity.…”

“…Increased recognition of the heterogeneity and plasticity of cardiac myocyte and non-myocyte populations [115] has prompted multiple studies using single cell analysis and individual cell profiling [118] . In the last two years, transcriptomic analysis has progressed from RNA-seq of bulk cardiac insterstitial populations [70] , to single cell transcriptional profiling of interstitial and primary cultures of cardiac origin [119,120] , and even single nucleus profiling of cardiomyocytes [74] .…”