title: Mesenchymal stem cells: molecular targets for tissue engineering.
abstract: Mesenchymal stem cells (MSCs) represent an adherent, fibroblast-like population present not only in the bone marrow, but in a number of tissues, including blood, adipose tissue, muscle, and dermis. Their extensive proliferation and transdifferentiation potential makes them best suited for tissue engineering applications. Identification of growth factors and signaling pathways involved in self-renewal and differentiation is important for designing strategies to overcome replicative senescence and attain directed differentiation. Wnt, bone morphogenetic protein (BMP), and Notch pathways have been implicated to play key roles in self-renewal and differentiation of hematopoietic, intestinal, and epidermal stem cells. They are also involved in regulating MSC differentiation. However, MSC self-renewal has not received much attention, with Nucleostemin being the only recently identified proliferation molecule. Although immortalization using viral oncogenes and telomerase has been achieved, transformation in long-term cultures is a potential risk. Understanding of the mechanisms governing osteogenic differentiation of MSCs is expanding with the recent identification of two major transcription factors, Osterix and Runx2. Enhanced expansion as well as osteogenic differentiation of MSCs can be attained using a combinatorial approach involving co-expression of proliferation and differentiation genes. However, a thorough understanding of the molecular mechanism is necessary for enhancing the self-renewal ability and osteogenic potential in vitro.
authors.affiliation: Stem Cell Gene Therapy Research Group, Institute of Nuclear Medicine & Allied Sciences, Timarpur, Delhi, India.
authors.forename: Neeraj Kumar
authors.initials: NK
authors.lastname: Satija
authors.forename: G U
authors.initials: GU
authors.lastname: Gurudutta
authors.forename: Shilpa
authors.initials: S
authors.lastname: Sharma
authors.forename: Farhat
authors.initials: F
authors.lastname: Afrin
authors.forename: Pallavi
authors.initials: P
authors.lastname: Gupta
authors.forename: Yogesh Kumar
authors.initials: YK
authors.lastname: Verma
authors.forename: Vimal Kishor
authors.initials: VK
authors.lastname: Singh
authors.forename: R P
authors.initials: RP
authors.lastname: Tripathi
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D016922:Cellular Senescence; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D010012:Osteogenesis; D015398:Signal Transduction; D023822:Tissue Engineering / Q000379:methods*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D014157:Transcription Factors