Reversal of the Developmental Aging of Normal Human Cells

BioTime, Inc., a biotechnology company that develops and markets products in the field of stem cells and regenerative medicine, announced the publication of a scientific paper titled "Spontaneous Reversal of Developmental Aging in Normal Human Cells Following Transcriptional Reprogramming." The article was released online in the peer-reviewed journal Regenerative Medicine in advance of the print publication.

The demonstration that the aging of human cells can be reversed may have significant implications for the development of new classes of cell-based therapies targeting age-related degenerative disease. The on-line version of the article can be found at www.futuremedicine.com

In the article, BioTime and its collaborators demonstrate the successful reversal of the developmental aging of normal human cells. Using precise genetic modifications, normal human cells were induced to reverse both the "clock" of differentiation (the process by which an embryonic stem cell becomes the many specialized differentiated cell types of the body), and the "clock" of cellular aging (telomere length). As a result, aged differentiated cells became young stem cells capable of regeneration.

The paper sheds light on the recent controversy over the aged status of induced pluripotent stem (iPS) cells. iPS cell technology has excited the scientific community because it has been demonstrated to be a method of transforming adult human cells back to a state very similar to embryonic stem cells (reversing the process of development) without the use of human embryos. However, recent reports have suggested that iPS cells, though very similar to embryonic stem cells in many respects, may not have the normal replicative potential of embryonic stem cells (that is, the iPS cells may be prematurely old). This problem has been called "the Achilles heel of iPS cell technology." BioTime scientists and their collaborators show in this paper that many iPS cell lines currently being circulated in the scientific community have short telomeres, meaning that their clock of cellular aging is still set at the age of relatively old cells. However, among these prematurely old cells, other cells can be found with sufficient levels of telomerase (a protein that keeps reproductive cells young) that allow these cells to reverse cellular aging all the way back to the very beginning of the human life cycle.

The research reported in this paper is part of BioTime's broader research strategy to advance the capabilities of the company's proprietary ReCyte technology. ReCyte is being developed as a means of implementing iPS technology on an industrial scale. The study published intentionally used older viral-based means of introducing genes. Therefore, BioTime plans further studies of cellular aging reversal using its proprietary ReCyte technology. BioTime has filed new patent applications on methods used in the paper to reverse the developmental aging of cells and the use of transcriptional reprogramming to produce young cells of many types for use in regenerating tissues affected by aging.