Reprod Biomed Online. 2006 Oct;13(4):562-72.
Potential clinical applications using stem cells derived from human umbilical cord blood.
· Ghen MJ,
· Roshan R,
· Roshan RO,
· Blyweiss DJ,
· Corso N,
· Khalili B,
· Zenga WT.
Eden Laboratories Ltd, Frederick House, Frederick Street, PO Box SS-19392, Nassau, The Bahamas. [email protected]
There is an abundance of clinical applications using human umbilical cord blood (HUCB) as a source for stem cell populations. Other than haematopoietic progenitors, there are mesenchymal, endothelial stem cells and neuronal precursors, in varying quantities, that are found in human umbilical cord blood. These may be useful in diseases such as immune deficiency and autoimmune disorders. Considering issues of safety, availability, transplant methodology, rejection and side effects, it is contended that a therapeutic stem cell transplant, utilizing stem cells from HUCB, provides a reliable repository of early precursor cells that can be useful in a great number of diverse conditions. Drawbacks of relatively smaller quantities of mononucleated cells in one unit of cord blood can be mitigated by in-vitro expansion procedures, improved in-vivo signalling, and augmentation of the cellular milieu, while simultaneously choosing the appropriate transplantation site and technique for introduction of the stem cell graft.
PMID: 17007681 [PubMed – indexed for MEDLINE]
Swiss Med Wkly. 2006 May 27;136(21-22):333-7.
Haematopoietic stem cells and mesenchymal stem cells as tools for present and future cellular therapies.
· Kindler V,
· Suva D,
· Soulas C,
· Chapuis B.
Haematology Service, Geneva University Hospital, 25 Micheli-du-Crest, CH-1211 Geneva 14, Switzerland. [email protected]
Postnatal stem cells are present in many adult tissues, and are thought to ensure homoeostasis by replacing functionally declining cells by newly differentiated ones. Postnatal stem cells used as such or after in vitro manipulation hold out strong hopes for reconstructive therapies. For instance, the grafting of native haematopoietic stem cells (HSC) restores haematopoiesis in genetically deficient individuals or in lethally conditioned leukaemic patients, and systemic injection of in vitro amplified mesenchymal stem cells (MSC) induces recovery of bone growth in patients with osteogenesis imperfecta. Moreover, cells differentiated in vitro from postnatal stem cells exhibiting a specific function can also be used for cell therapy. Myeloid dendritic cells (DC) derived from cultures of HSC may induce tumour-specific cytotoxic T lymphocytes to eradicate the tumour via antigen recognition. In addition, long-lived MSC has been engineered to secrete specific proteins coded by a transgene and used as a source of therapeutic molecules in vivo. All these approaches require large quantities of cells that cannot be obtained (with the exception of HSC) directly from the donor. In vitro procedures allowing the production of therapeutic cells from postnatal stem cells are needed and are at present under development. Below we discuss the rationale and methods currently available for generation of therapeutic cells derived from haematopoietic and mesenchymal stem cells.
PMID: 16826633 [PubMed – indexed for MEDLINE]
Crit Rev Eukaryot Gene Expr. 2006;16(3):211-32.
Mechanisms controlling embryonic stem cell self-renewal and differentiation.
· Sun Y,
· Li H,
· Yang H,
· Rao MS,
· Zhan M.
Bioinformatics Unit, Research Resources Branch, National Institute on Aging, NIH, Baltimore, MD 21224, USA.
Embryonic stem (ES) cells are pluripotent cells with indefinite replication potential and ability to differentiate into all types of cells. An understanding of the regulatory mechanisms responsible for pluripotency in ES cells is critical for realizing their potential in regenerative medicine and science. Cross-species studies on ES cells have identified pathways and networks that are either fundamental to or species-specific for self-renewal and differentiation. Although pluripotency as an essential function in multicellular organisms is conserved through evolution, mechanisms primed for differentiation contribute substantially to the differences among stem cells derived from different tissues or species. Transcriptome mapping analysis has determined the chromosomal domains of gene coexpression patterns specific to the ES state and demonstrated that regulation of ES cell development is operative at both the local chromosomal domain level and global level. Combinatorial signals from multiple pathways regulate the expression of key intrinsic factors critical for ES cell fate determination. The regulatory core formed by Oct4, Sox2, and Nanog, in particular, activates genes critical for self-renewal and represses genes initiating differentiation, controlling ES cell pluripotency. Here, we review recent findings on mechanisms controlling ES cell development. By integrating data from different sources, we present a global picture of how ES cells reach the decision of self-renewal or differentiation.
PMID: 17073552 [PubMed – in process]