Leukemia inhibitory factor (LIF) plays important roles in varieties of biological processes. This factor is highly conserved in mammalian animals and only one heterozygous LIF mutation was reported to cause the infertility of women. A LIF mutation was generated and the evidences were provided that the mutation of mature LIF at the 29th amino acid totally abolished its functions, including stimulation of STAT activation assayed by Luciferase reporter gene expression and EMSA experiments. In addition, the mutated LIF failed to inhibit the proliferation of M1 cells. The data indicated that the mutation of LIF did not have a dominant negative effect but lost the biological functions, suggesting that the 29th amino acid is critical for maintaining the activities of LIF.

Stem cells hold great promise for regenerative medicine because of their ability to self-renew and to differentiate into various cell types. Although embryonic stem cells (BSC) have greater differentiation potential than adult stem cells, the former is lagging in reaching clinical applications because of ethical concerns and governmental restrictions. Bone marrow stem cells (BMSC) are the best-studied adult stem cells (ASC) and have the potential to treat a wide variety of diseases, including erectile dysfunction (ED) and male infertility. More recently discovered adipose tissue-derived stem cells (ADSC) are virtually identical to bone marrow stem cells in differentiation and therapeutic potential, but are easier and safer to obtain, can be harvested in larger quantities, and have the associated benefit of reducing obesity. Therefore, ADSC appear to be a better choice for future clinical applications. We have previously shown that ESC could restore the erectile function of neurogenic ED in rats, and we now have evidence that ADSC could do so as well. We are also investigating whether ADSC can differentiate into Leydig, Sertoli and male germ cells. The eventual goal is to use ADSC to treat male infertility and testosterone deficiency.
Adult Stem Cells ; Animals ; Cell Transplantation ; Embryonic Stem Cells ; Erectile Dysfunction ; therapy ; Humans ; Infertility, Male ; therapy ; Male ; Research