Immortalized stem cell, compositions, preparations and uses thereof
The purpose of the present invention is to provide immortalized stem cells, which produce a growth factor capable of regenerating various kinds of tissues that have been damaged by a variety of causes, and a method for producing the aforesaid immortalized stem cells. Another purpose is to provide a medicinal composition and a medicinal preparation for restoring damaged tissues, and a method for the percutaneous absorption of a culture supernatant. Provided are immortalized stem cells that are obtained by isolating stem cells selected from the group consisting of mammalian mesenchymal cells, an embryo at the early stage of the development and somatic cells, first culturing the cells to give first stage culture cells, transferring four kinds of genes into the first stage culture cells to give transgenic cells, and selecting the desired immortalized stem cells from among the transgenic cells using the expression of STRO-1 as an index.
1. An isolated population of genetically modified STRO-1 positive mammalian stem cells originated from dental pulp and produced by the method comprising:
isolating a mammalian dental pulp cell from dental pulp tissue;
performing a primary culture of said mammalian dental pulp cells to obtain primary cultured cells of exfoliated dens deciduous dental pulp stem cells (SHED);
transducing 4 genes, hTERT, bmi-1, E6, and E7, into said primarily cultured cells of SHED to produce gene-transduced cells SHED (SHED-P); and
selecting isolated transduced SHED-P,
wherein the isolated transduced SHED-P are characterized in that: (a) at least 40% of the isolated SHED-P are STRO-1 expression cells having increased neonatal bone quality production relative to non-transduced SHED at the population doubling time of 20, and (b) isolated transduced SHED-P expressing STRO-1 may divide at least 200 times and have telomere repairing ability.
2. The isolated population of genetically modified STRO-1 positive mammalian stem cells according to claim 1 , wherein said mammal is selected from the group consisting of human, swine, equine and monkey.
3. The isolated population of genetically modified STRO-1 positive mammalian stem cells according to claim 2 , wherein said population of genetically modified STRO-1 positive mammalian stem cells secretes at least IGF-1, VEGF, TGF-β1 and HGF into a culture supernatant.