MSCs from different sources may display some differences in the expression of surface markers. However, in general, the phenotypes of these cells are very similar and in the absence of an individual specific marker, MSCs are commonly buy Topotecan defined by a panel of cell surface markers that include CD73, CD90 (Thy-1), CD105 (endoglin) and MHC class I, as well as the adhesion molecules CD44, CD29, CD54 (ICAM-1; intercellular adhesion molecule 1), CD106 (VCAM-1; vascular cell adhesion molecule) and CD166[11]. MSCs do not express hematopoietic markers such as CD34, CD45, CD14 and CD11 or co-stimulatory molecules like CD80, CD86 and CD40[11]. According to the minimal criteria

of the International Society of Cellular Therapy (ISCT, 2006), the required functional and phenotypic features for defining MSCs include: (1) plastic adherence of the isolated cells under standard culture conditions; (2) positive expression of CD105, CD90 and CD73 markers in at least 95% of a cell population and lack of expression of CD34, CD45, CD11b, CD14, CD19 or CD79a and HLA-DR markers in greater than 95% of the culture, as measured by flow cytometry; and (3) trilineage differentiation potential into osteoblasts, adipocytes and chondroblasts in in vitro culture with

specific stimuli[12]. Besides this, trilineage multipotency experimental data have demonstrated that MSCs can also differentiate into other mesodermal lineages, such as skeletal myocytes[13,14], cardiomyocytes[15], tenocytes[16,17] and endothelial cells[18,19]. Moreover, it has been reported that under appropriate conditions, MSCs have the capacity to differentiate into types of cells of endodermal and ectodermal lineages, including hepatocytes[20,21], neuronal cells with neuron-like functions[22-24], insulin-producing cells[25,26], photoreceptor cells[27], renal tubular epithelial cells[28], epidermal and sebaceous duct cells[29]. In addition to their

comprehensive differentiation potential, MSCs have the ability to migrate and engraft at sites of inflammation and injury in response to cytokines, chemokines and growth factors[30,31]. At a wound site, they can exert local reparative effects through transdifferentiation into tissue-specific cell types or via the paracrine secretion Anacetrapib of soluble factors with anti-inflammatory and wound healing activities[32-34]. Another aspect that makes MSCs of particular clinical interest is the finding that they exert a wide range of immunomodulatory activities affecting both cell-mediated and humoral immune response. A search in the PubMed data base reveals 149 papers, while the ScienceDirect data base contains 495 papers in peer-reviewed journals describing animal models developed to study various aspects of the immunomodulatory effects of MSCs in the period of 2001-2014.