Similar characteristics have been identified in MSCs derived from adipose tissue and BM. For example, both cells have the capacity to differentiate into multiple cell types. They also release growth factors and cytokines, although not the same factors
[19]. MSCs circulate in or exist in tissue niches surrounded by low oxygen levels. Cell populations and characteristics also differ between adult and neonatal tissues
[20]. Adolfsson et al. compared MSCs derived from the BM with those derived from adipose tissue. They found that adipose-derived MSCs proliferated more than BM-derived MSCs, and adipose-derived MSCs had higher
angiopoetin 1 (
angpt1),
Leukemia inhibitory factor (
LIF), and
Transforming growth factor (
TGF)-β1 expression levels, but equal
VEGF-A and
HGF expression levels compared with BMSCs
[21]. Conditioned medium from adipose-derived stromal cells has also been studied because of its positive ameliorating effect on various damaged tissues, including the infarcted heart, which occurs through paracrine factors
[22]. Lu et al. fractionated conditioned media based on molecular weight and found that fractions over 50 kD protected the endothelium from barrier dysfunction caused by H
2O
2 and fractions less than 3 kD protected against apoptosis induced by tumor necrosis factor (TNF)-α
[23]. Lai et al. reported that exosomes from conditioned media from adipose-derived MSCs contained high levels of miR-221/222 and attenuated myocardial infarction in a mouse model. Knockout of miR-221/222 in mice increased apoptosis and fibrosis; however, treatment with conditioned medium from adipose-derived MSCs decreased apoptosis and fibrosis
[24]. Lee et al. found that intramuscular injection of conditioned media from adipose-derived MSCs attenuates ischemia in mice
[25]. Taken together, exosomes from adipose-derived stromal cells ameliorated ischemia through the action of miR-221/222.
Attempts have been made to differentiate adipose-derived stem and stromal cells into cardiomyocytes. Seheli et al. reported that 5-azacytidine, a DNA methyltransferase inhibitor, played a role in this differentiation
[26]. Darche et al. reported that adipose-derived stem/stromal cells can function as pacemaker cells
[27]. However, Stepniewski et al. compared the abilities of iPSC-CMs and adipose-derived stem/stromal cells (derived CMs) to cure myocardial infarction and demonstrated better outcomes with iPSC-CMs
[28].