LIF2010 Sigma-AldrichLeukemia Inhibitory Factor from mouse

The pluripotency and high proliferative capacity of embryonic stem (ES) cells (1-3) makes them an attractive source of different cell types for biomedical research and cell replacement therapies. A major prerequisite for these applications is the availability of a homogeneous population of the desired cell type. However, ES cell-derived material contains, for example, undifferentiated cells, which can cause tumor formation after transplantation into the brain (4). To avoid such unwanted side effects, effective purification of distinct types of cells needs to be developed. Here, we describe an immunoisolation procedure to purify neurons from in vitro differentiated mouse ES cells using an antibody against the neuronal cell adhesion molecule L1 (5, 6). Our procedure yields a pure population of differentiated neurons, which are electrically excitable and form excitatory, glutamatergic, and inhibitory GABAergic synapses. The ability to highly purify ES cell-derived neurons will boost their molecular characterization and the further exploration of their therapeutic potential.

Using in situ hybridization histochemistry, we characterized the spatiotemporal gene expression patterns of leukemia inhibitory factor (LIF) and glial cell line-derived neurotrophic factor (GDNF), and their receptor components (LIFR, GFR-alpha1, RET) induced in muscle cells, intramuscular nerves, and motoneurons in the regeneration processes of both muscle cells and nerves following muscle contusion. Muscle contusion induced upregulation of GDNF and GFR-alpha1 mRNAs in Schwann cell-like cells in the intramuscular nerves and of LIFR mRNA in damaged muscle cells. LIFR, GFR-alpha1, and RET mRNA expressions in motoneurons were upregulated following muscle contusion. Muscle contusion also induced more rapid, prominent transactivations of GFR-alpha1 and RET genes in motoneurons than did sciatic nerve axotomy. These findings suggest that rapid and prominent upregulation of the receptor components for LIF and GDNF in motoneurons is important for the regeneration of intramuscular motor nerves damaged by muscle contusion.

The isolation and expansion of human neural progenitor cells have important potential clinical applications, because these cells may be used as graft material in cell therapies to regenerate tissue and/or function in patients with central nervous system (CNS) disorders. This paper describes a continuously dividing multipotent population of progenitor cells in the human embryonic forebrain that can be propagated in vitro. These cells can be maintained and expanded using a serum-free defined medium containing basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF), and epidermal growth factor (EGF). Using these three factors, the cell cultures expand and remain multipotent for at least 1 year in vitro. This period of expansion results in a 10(7)-fold increase of this heterogeneous population of cells. Upon differentiation, they form neurons, astrocytes, and oligodendrocytes, the three main phenotypes in the CNS. Moreover, GABA-immunoreactive and tyrosine hydroxylase-immunoreactive neurons can be identified. These results demonstrate the feasibility of long-term in vitro expansion of human neural progenitor cells. The advantages of such a population of neural precursors for allogeneic transplantation include the ability to provide an expandable, well-characterized, defined cell source which can form specific neuronal or glial subtypes.