5.2. Mesenchymal stem cells

The lineage of mesenchymal stem cells (MSCs) is characterized with self-renewal capacity and multipotent stem cells-like abilities. They were originally isolated from the bone marrow [61, 62] and have been reported to differentiate into several cell types [63–68]. The MSCs have also been shown to transdifferentiate into variety of neuronal cells in different animal models [69– 72]. The MSCs that qualify transplantational procedure are known as multipotent mesenchymal stromal cells [73], which are having several subtypes that are being therapeutically evaluated for SCIs in different clinical trials. After their transplantation into lesion site, they are thought to be regulated by secretion of trophic factor, which stimulates new vessels formation and anti-inflammatory factors [74]. Moreover, MSCs are being reported to secrete different cytokines and associated growth promoting factors that exhibit both paracrine and autocrine characteristics. These biologically active secreted factors have been shown to suppress the intrinsic immunological repsonse, prevent apoptosis and formation of glial scars, improve angiogenesis and stimulate cell cycle to enhance regenerative activities [75].
