What do we need to know to become stem cell literate?

AND THE VALUE OF HUMAN LIFE The challenge of stem cell research….. MAINTAIN A COMMITMENT TO BOTH THE ADVANCEMENT OF SCIENCE FOR THE BETTERMENT OF MANKIND AND TO THE DEFENSE OF HUMAN FREEDOM, DIGNITY AND THE VALUE OF HUMAN LIFE

Two Characteristics of Stem Cells Able to make more them of themselves (self-renewal) through cell division. Under experimental conditions can become committed to a specific organ or tissue (differentiation).

FUNCTIONAL DEFINITION OF A STEM CELL Cell Divided Differentiation Stem Cell: A cell that can both renew itself and produce new cells that will form a tissue.

What type of stem cells exist? 1 – Multipotent stem cell: give rise to a SMALL NUMBER of cell types found in a mature tissue that can only yield specialized cell types (dental stem cell) 2 - Pluripotent stem cell: give rise to ANY cell types found in the body (embryonic or induced pluripotent stem cell)

MULTIPOTENT “ADULT” (post-birth) STEM CELLS CAN MAKE MULTIPLE CELL TYPES, BUT NOT ALL CELL TYPES IN PEOPLE LIKE US

Human pluripotent stem cells hold Great promise for medical therapy… PLURIPOTENT- Can develop (differentiate) into ALL cell types and specialized tissues in the body EXPANDABLE - Ability to be grown for a long time in laboratory culture without losing “self-renewal” capacity SELF RENEWAL – can produce cells that become all cell types AND a cell that remains PLURIPOTENT

Where do embryonic stem cells come from?

EMBRYONIC STEM CELLS AND “POTENCY”

An “ethical threshold” is driving stem cell science PROBLEM: Human embryonic stem cells can not presently be obtained without destroying human embryos. CHALLENGE: Is there a way for scientists to “harvest” pluripotent stem cells without creating, destroying of harming human embryos. Are there other ways to make sources of such stem cells?

Finding ethically-uncontroversial ways to advance human embryonic stem cell research Somatic cell nuclear transfer (SCNT) provides donor-specific stem cells (Hello Dolly!!) THIS IS HUMAN CLONING…… 11

SOMATIC CELL NUCLEAR TRANSFER OR CLONING CAN WE FIND NEW SOURCES OF EMBRYONIC STEM CELLS – SOMATIC CELL NUCLEAR TRANSFER OR CLONING Remove nucleus from adult donor cell and inject into an egg Nucleus undergoes reprogramming to behave like pluripotent stem cell

Somatic Cell Nuclear Transfer Problems with Somatic Cell Nuclear Transfer Ethical obligations to manipulating and sourcing donor eggs (donor abuse) Very expensive Inefficient – problems with embryo survival Cloning of an identical human being.

What is the risk of human cloning?? Asexual reproduction to produce an organism identical to a previously existing, human 1 - THERAPEUTIC CLONING - human cloning to derive cells for therapy 2 - REPRODUCTIVE CLONING – human cloning for purpose of reproducing another human

NOBEL PRIZE FOR CREATING PLURIPOTENT STEM CELLS…. UNCONTROVERSIAL PLURIPOTENT STEM CELLS?

HOW REPROGRAMMING MAY CHANGE THE WORLD Alzheimer Parkinson Diabetes ALS SMA … Rodolfa and Eggan 16

Questions Are hESCs still necessary? Can we decide if iPSC can and should replace hESC? Would using iPSC resolve all ethical dilemmas about pluripotent stem cell research? Are these ethically-relevant differences between iPSC vs. hESC?

Safety And Effectiveness Of Future Therapies Safety And Effectiveness Of Future Therapies? Safety Standards For Cells Science Issue: Both iPSC and hESC are defined by making tumors in animals. Ethical Problem: First clinical iPSC trial halted for safety reasons. Solution: no clear conclusions on safety or value of iPSC vs hESC for human therapy.

Mitochondrial Disease The mitochondria are cells in the cytoplasm— sometimes hundreds. Each cell has 37 genes compared to 20-30,000 in the cell’s nucleus.

Gene Therapy Gene Therapy Somatic Cell Germ Line Gene Therapy Gene Therapy MORAL BOUNDARY

Options for prospective mother with mt disease Obtain donor egg with partner’s sperm Have prenatal genetic diagnosis on intending mother’s eggs to determine the eggs with least mt mutations. adopt a child Go through ooplasmic transfer; MST, or PNT

CRISPR/Cas9 System Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins

Genome Editing Technologies (CRISPR) And Human Germline Genetic Modification Possible to insert, delete, or modify DNA with greatly increased specificity and efficiency. Use to correct genetic defects or introduce other potentially therapeutic changes. The potential for modification of the human germline. Concern that genome editing technologies might be used to modify embryos before there are data sufficient to support use.

What is it? derived from a natural process found in bacteria to protect themselves from pathogens targets genes for editing and regulating Can modify genes in embryos that can cross the “germ line” Horizon Licenses Harvard University Gene-Editing Technology. (2013). Drug Discovery & Development.

To initiate gene modification, sgRNA (single guide RNA) Cas9 complex Cas9 nuclease

Protospacer Adjacent Motif (PAM) Target Sequence Gene of Interest

Needed Basic Scientific Research or CRISPR- Much To Be Learned Research to understand and improve the technique of genome editing itself. How to best use genome editing as a tool to address fundamental research questions. Research to generate preliminary data for the development of human somatic (non-germline) applications. Research to inform the plausibility of developing safe human reproductive applications.

What Should We Do With CRISPR? Basic research? Clinical application? Public engagement? Governance? Clinical reproductive purposes?