A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs): An Achievement of Significant Morphological, Numerical and Functional Recovery
Fig 1
Fluorescence activated cell sorting (FACS) analysis of human Sk-SCs before and after expansion culture, and sorting of human Sk-34 and Sk-DN cells.
(A) Characteristics of human Sk-SCs just after thawing, in a putative freshly isolated state. First, CD45+ cells were discarded as hematopoietic cells, and the remaining cells were analyzed further. Based on the results in (A), possible markers for cell sorting were CD29, CD34, CD73, and p75 (CD271). (B) We then selected CD29 and CD34, and sorted three types of cell: Sk-34/29- (CD34+/45-/29-), Sk-34/29+ (CD34+/45-/29+), and Sk-DN/29+ (CD34-/45-/29+). We also confirmed the concentration of p75+ cells (see panels P6, P7, and P8). (C) Characteristics of the three types of cell after 2 weeks of expansion culture. Basically, three types of cell showed similar characteristics, while a lower distribution of p75+ cells was seen in Sk-34/29- cells than in the initial state (see P6 in B). Note that the patterns of Sk-34/29+ and Sk-DN/29+ are similar, but that they showed quite different behaviors after in vivo transplantation (see Fig 1). Therefore, in our cells, FACS characteristics after expansion culture did not reflect in vivo differentiation capacity after transplantation. The validity of using CD29 in the detection of human cells (see Fig 2) is also evident (C), because of their whole positivity. Standard cell sorting was performed on all samples, and detailed FACS analysis was performed using 3 males and 1 female (ages: 17, 27, 60, and 79; muscles: soleus, gastrocnemius, and tibialis anterior).