Bone marrow mesenchymal stem cells

Abstract

Following the identification of bone marrow multipotent cells that could adhere to plastic and differentiate along numerous mesenchymal lineages in vitro, a considerable effort has been invested in characterizing and expanding these cells, which are now called "mesenchymal stem cells" (MSCs), in vitro. Over the years, numerous lines of evidence have been provided in support of their plasticity, their extraordinary immunomodulatory properties, their potential use for tissue engineering purposes, as well as their ability to be recruited to sites of injury, where they might contribute a "natural in vivo system for tissue repair." Moreover, some studies have attempted the characterization of their cell-surface specific antigens and of their anatomical location in vivo. Lastly, it has been shown that similar cells could be also isolated from organs other than the bone marrow. Despite this impressive body of investigations, numerous questions related to the developmental origin of these cells, their proposed pluripotency, and their role in bone modeling and remodeling and tissue repair in vivo are still largely unanswered. In addition, both a systematic phenotypic in vivo characterization of the MSC population and the development of a reproducible and faithful in vivo assay that would test the ability of MSCs to self-renew, proliferate, and differentiate in vivo are just beginning. This brief review summarizes the current knowledge in the field of study of MSCs and the outstanding questions.

Mesenchymal stem cells express serine protease inhibitor to evade the host immune response

“…25,26 FACS results also showed negative expression for the costimulatory molecules CD80 and CD86 as reported previously (data not shown). 27,28 Both MSC types shared similar characteristic morphology, with large, clear nuclei ( Figure 1B). Cultured MSCs at passages 5 and 6 were stimulated to differentiate, respectively, either into chondrocytes, osteocytes, or adipocytes ( Figure 1B), as described previously.…”

IL-12p40 impairs mesenchymal stem cell-mediated bone regeneration via CD4+ T cells

“…Although most heal normally, 5-20% of fractures result in delayed or impaired healing requiring therapeutic intervention. 1 Bone marrow mesenchymal stem cell (BMMSC)-based therapy is an attractive option for augmenting the fracture repair process and BMMSCs have been used for the treatment of fracture non-union in clinical studies, 2,3 because of their fast and easy purification, amplification, multipotent differentiation ability, and low immunogenicity. 4,5 However, 10-18% of fractures stayed non-union after stem cell therapy in early clinical reports.…”

Bone marrow-derived mesenchymal stem cells (MSCs) stimulate neurite outgrowth from differentiating adult hippocampal progenitor cells

“…A growing body of literature indicates that MSCs possess phenotypic plasticity and are able to generate myoblasts, tendon/ ligament fibroblasts, adipocytes, osteocytes, and chondrocytes [5]. Karaoz et al, [31] demonstrated endogenous expression of osteo-, myo-, and neuro-genic markers, which supports the plasticity of rat MSCs to differentiate into various cell types.…”

“…Gaining a better understanding of how MSCs mediate neural repair will benefit the development of novel therapeutic strategies [1][2][3][4]. Multipotent bone marrow-derived MSCs can be readily isolated due to their characteristic adherence to tissue culture polystyrene surfaces and have the ability to self-renew and can differentiate into various mesodermal lineages such as bone, cartilage, and fat cells [5]. Importantly, bone marrow-MSCs are a potential candidate for autologous transplantation, thus avoiding an immune response in the host.…”