The objective of the study is to evaluate efficiency
of in vitro isolation and myogenic differentiation of
mesenchymal stem cells (MSCs) derived from adipose connective
tissue (AD-MSCs), bone marrow (BM-MSCs), and
skeletal muscle tissue (MC-MSCs). MSCs were isolated
from adipose connective tissue, bone marrow, and skeletal
muscle tissue of two adult 6-wk-old rats. Cultured MSCs
were treated with 5-azacytidine (AZA) to induce myogenic
differentiation. Isolated MSCs and differentiated cells were
evaluated by immunocytochemistry (ICC), fluorescenceactivated
cell sorting (FACS), PCR, and RT-PCR. ADMSCs
showed the highest proliferation rate while BMMSCs
had the lowest one. In ICC, isolated MSCs had strong
CD90- and CD44-positive expression and negative expression
of CD45, CD31, and CD34, while AZA-treated MSCs
had strong positive desmin expression. In FACS analysis,
AD-MSCs had the highest percentage of CD90- and CD44-
positive-expressing cells (99% and 96%) followed by BMMSCs
(97% and 94%) and MC-MSCs (92% and 91%).At
1 wk after incubation with AZA treatment, the peak of
myogenin expression reached 93% in differentiated MCMSCs,
83.3% in BM-MSCs, and 77% in AD-MSCs. MSCs
isolated from adipose connective tissue, bone marrow, and
skeletal muscle tissue have the same morphology and phenotype,
but AD-MSCs were the most easily accessible and
had the highest rate of growth on cultivation and the highest
percentage of stem cell marker expression. Moreover, although
MC-MSCs showed the highest rate of myogenic
differentiation potential and expression of myoblast
markers, AD-MSCs and BM-MSCs still can be valuable
alternatives. The differentiated myoblastic cells could be an
available new choice for myoblastic auto-transplantation in
regeneration medicine.