Generation of human embryonic stem cell lines with clinically relevant mutations

Human embryonic stem (hES) cells can be isolated from early (4-8 day old) developing embryos which have been grown in the laboratory as part of, or surplus to some kinds of IVF treatment. Under certain conditions, these can be made to develop into different kinds of cells, such as nerve, or pancreatic cells which it is hoped in the future, may be useful in treating degenerative diseases such as Parkinson s disease and diabetes, or in spinal injuries by replacing the diseased or damaged cells with healthy hES cells which have been grown in the laboratory. However in addition to this potential use in therapy, the study of stem cells in the laboratory which contain clinically relevant genetic mutations - ?diseases in a dish? - may give us insights in to the early developmental mechanisms in certain genetic disorders.
With the Assisted Conception Unit (ACU) at Guy s we have been using surplus embryos donated by patients undergoing preimplantation genetic diagnosis treatment (PGD). PGD is offered to couples who carry a serious genetic disorder where the embryos are tested for the disorder prior to implantation in order to prevent transmission of diseases such as Huntington s disease, Duchenne muscular dystrophy, and spinal muscular atrophy. Embryos that are found to be free of disorder can be transferrred back to the patient s womb, or frozen for their later use. Those which will develop the genetic disorder or are of uncertain status and should not be placed back into the woman?s womb have been used to generate stem cell lines which contain the specific genetic mutation, and will be useful in understanding more about these diseases, and developing new treatments for them. All stem cell derivation from embryos is strictly monitored in the UK and requires a licence from the Human Fertilisation and Embryology Authority. It is a condition of licence that samples of any suitable stem cell lines developed must sent to the UK Stem Cell Bank from where they are made freely available to research scientists in the UK and abroad through the MRC Stem Cell Steering Committee.

The development and support of the UK stem cell bank at NIBSC is a clear signal of the UK?s commitment to support both local and international research on stem cells, and to the development of lines suitable for research and clinical use. Besides the need to generate human embryonic stem (hES) cell lines for therapeutic use, there is the opportunity to use hES cell lines as an in vitro alternative to animal experiments for studying cell-cell or developing organ interactions, and the effect of pharmacological agents. Such an approach is likely to be especially useful in lines generated from embryos shown to contain specific clinically relevant genetic mutations following PGD. This strategy is predicated on the assumption that disease-carrying hESCs will differentiate faithfully and reliably into relevant differentiated cells that are functionally competent. This application seeks to test the hypothesis that disease-carrying hESCs reliably express the disease phenotype in neuroprogenitors and muscle cells after hESC differentiation in vitro. Being the largest and most successful PGD unit in the UK, and the first internationally to establish and characterise a line carrying the common deltaF508 mutation, as well as two lines containing HD expansions, we are in a leadership position to both establish and characterise additional disease carrying hESCs. It is our intention, using morphological, immunological, and molecular markers, to explore the development of neurones in stem cells with HD expansions, cardiomyocyte development and physiology in Duchenne muscular dystrophy (DMD) and neurones and myocytes in spinal muscular atrophy (SMA), which are among our most common diagnostic requests. In addition to these, we are likely to be able to generate lines with other clinically relevant mutations, which will be an invaluable research resource to others investigators which we will make available internationally through the UK Stem Cell Bank (UKSCB).