Peter J.
Hornsby,
Ph. D.
University of Texas Health Science Center - San Antonio
Cell Transplantation Models for Gene Action in Human Aging.
The overall aim of this grant is to provide new methods for the study of gene action in human aging, using cell transplantation techniques applied to human adrenocortical cells. Prior to beginning this grant, we had established methods for genetic modification of bovine adrenocortical cells and for examining the function of genetically modified cells after they have been introduced into scid mice. Normal human adrenocortical cells, and both normal and genetically modified bovine adrenocortical cells, may be transplanted in scid mice where they form a functional vascularized tissue structure. The ability to form tissues from genetically modified cells forms a new technique for the study of gene action in tissue aging. Genes that may be important in human aging can be altered and the effects can be monitored in the transplant tissues. Initially we proposed to inactivate genes by homologous recombination, but the recent advances in small interfering RNA (siRNA) technology in mammalian systems have provided an opportunity for the much more rapid production of functional knockouts of genes that are of interest. For this reason we have developed retroviruses encoding siRNAs that functionally inactivate the Werner gene, a gene thought to be of interest in human aging, as well as p53 as a control gene. Bovine adrenocortical cells that have been transduced with these retroviruses are being transplanted in scid mice to assess the tissue phenotypes conferred by these functional gene knockouts.
