Induced Pluripotent Stem Cells Stem Cells and Neurological Disorders (iPSCs) Pluripotent cells make all types of cells Multipotent cells make some types of cells unipotent cells make just one type of cells -Embryonic cells are the most potent but have ethical &rejection problems -The best days to take the embryo cells are from 4-5 days Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Induced Pluripotent Stem Cells (iPSCs): (By a Japanese scientist and took the Nobel prize after 5 years of the discovery) = Retro-differentiation = Re-programming Producing stem cells from differentiated cells !!! Pluripotent embryonic like stem cells are produced Reversal of normal process Does Not require human embryos No donor…..No rejection Less expensive No Ethical issues Induced means that not naturally exist and we make it Pluripotent=acts like embryonic cell In this procedure we format the cell and make it forget its function and back it to its native home which is the embryonic cells Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Main Key Genes: iPSCs are derived from adult somatic cells by inducing expression of certain Stemness genes: (usually by viral vectors: risk !!!) - eg: Master transcriptional regulators: Oct-4 Sox2 Nonog - other genes: c-Myc (oncogene: cancer risk !!!!) In each cells there are many genes but there are just a fraction of them are active depending on the type of the cell,so the heart and liver cells have the same genes but in each of them some genes have been activated and the rest are sleepy These master transcription factor can activate any type of genes but they are inactivated in differentiated cells so we put an external master transcription gene by a viral vector and this master key can activate all genes so the cell becomes a pluripotent cells and the scientists even can make more earlier cells (Totipotent) !! So from this induced stem cell now we can make any type of cells we want Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Pluripotency: Believed to be identical to embryonic stem (ES) cells in many respects: - expression of certain stemness genes - chromatin methylation patterns - doubling time - embryoid body formation - teratoma formation - viable chimera formation - potency and differentiability Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Generation of induced pluripotent stem (iPS) cells Isolate and culture donor cells. (2) Transfect stemness genes into cells by viral vectors. Red cells express those genes (3) Harvest and culture the cells according to ES cell culture, on feeder cells (light gray) (4) A subset of the transfected cells become iPS cells and generate ES-like colonies    Stem Cells and Neurological Disorders

Neurogenesis of iPS Pluripotent Neuronal Stem Cells derived from Adult Leukocytes

Stem Cells and Neurological Disorders Potential target disorders for Stem Cell Therapy: Leukemia Heart damage Anemia Cornea damage Retinal damage Parkinson’s Alzhimer’s Diabetes Spinal Cord Injury Kidney Failure Skin grafts Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders leukemia Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Injecting a stem cells to the damaged myocardium and will return to its work Heart damage Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Diabetes Stem Cells and Neurological Disorders

Regenerative Medicine Stem Cells and Neurological Disorders Tissue Engineering & Regenerative Medicine Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Bone Repair Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Skin graft grown from stem cells Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Cornea Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders trachea from stem cells In the Trachea and the ear we need a scaffold to put the stem cells in and then cells will take the shape of the scaffold Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders A grown ear seeded with cartilage cells The scaffold is from a biodegradable matter so when the ear cells finish replication and take their final form we remove the scaffold Stem Cells and Neurological Disorders

Neurological Disorders Stem Cells and Neurological Disorders & Neurological Disorders This is one of the most important aspects of regenerative medicine because the neurons are postmitotic and cannot regenerate themselves rather than other tissues Stem Cells and Neurological Disorders

Which Stem Cell: Delivery Strategy: Graft type: HSC : Hematopoietic stem cells MSC : Mesencymal stem cells Which Stem Cell: 1. Neural stem cells 2. Other Adult SC (HSCs & MSCs)(Plastisity) 3. Cord Blood SC 3. Embryonic SC(Ethical problem) 4. iPSCs Delivery Strategy: Injection into brain Into Blood stream (Homing + immobilization by cytokines) Graft type: Stem cells + Biomaterial (a scaffold that will dissolve) Stem Cells + Gene therapy (I play with the genes of the stem cells so a certain chemical will be released more to treat the problem) All have been shown to generate neural tissue (Adult SCs are the mostly used in clinical trials) Homing means that the cells know where to go Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Comparison: Stem Cell  (Disadvantage) Embryonic Pluirpotent Ethics Fetal Pluripotent Ethics Cord Blood Potent Rejection Available Adult Neural / Autologus Self low Numbers Same tissue Isolation Adult (HSCs, MSCs,…) Easy isolation rejection (if allo.) Easy culture Plasticity ?!! iPCs Pluripotent vector safety Self From the same person Stem Cells and Neurological Disorders

Ongoing clinical Trials in US and the world 2012 Sanberg et al. February 2012

Stem Cells and Neurological Disorders Different strategies for stem cell delivery to repair degenerated tissue Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Neural stem cells: Generate new neural cells throughout the lifetime Can migrate and replace dying neurons Give rise to all types of neurons, astrocytes and oligodendrocytes, … Capable of only Minor repairs Their activity is up-regulated following injury - Found in: - Sub-ventricular zone of lateral ventricles (Most neurogenic area) - Dentate gyrus of Hippocampus (2nd) fewer in: - Cerebellum    - Spinal Cord Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Therapeutic Applications: Main target disorders: - Parkinson’s: localized degeneration (in substantia nigra) easier cell therapy Huntington’s: clear etiology, single gene disorders (Gene/Cell Therapy) Alzheimer : damage is less defined, widespread neuro-degeneration Spinal Cord injuries: very promising prospects Other: - Multiple Sclerosis (Siatskas and Bernard, 2009) Ischemia / stroke Epilepsy (Naegele et al., 2010) Amyotrophic Lateral Sclerosis (ALS) (Wolfson et al., 2009). Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Parkinson’s: Main Strategy: - Replacing degenerated neurons with dopamine-producing cells Site: - Substantia nigra: area were most degeneration occurs in PD - Source of SCs: - Pieces of fetal midbrain tissue (Mendez et al., 2005) - Autologous adult neural stem/progenitor cells (Michel et al., 2009) - Embryonic SCs (Friling et al. 2009) Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Huntington’s: Good Model: well characterized single gene disorder Main Strategy: Blocking neuronal cell death & replacing lost neurons in striatum - Source of SCs: - SCs of fetal striatal primordium into striatum of HD patients (Bachoud-Lévi et al., 2006) - Autologous adult neural stem/progenitor cells (Yu and Silva, 2008; Visnyei et al., 2006). Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Alzheimer’s: Neuro-genesis in hippocampus deteriorates in AD patients Example approaches: (Lunn et al., 2011) 1. Implanting Neural Stem Cells: - Replace lost neurons - Delay degeneration by producing Brain-Derived Neurotrophic Factor (BDNF) 2. Nerve growth factor (NGF) production: - Genetically engineered patient fibroblasts that produce NGF …!!! - Integration of NGF fibroblasts into a major cholinergic center of the basal forebrain provided some benefit to AD patients Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Spinal cord injuries: (Salewski et al., 2010; Hu et al., 2010, Mathai et al 2008). Stem cells can: 1. Replace neurons that died from injury 2. Generate supporting cells to re-form the myelin sheath & stimulate re- growth of damaged nerves 3. Protect cells at injury site from further damage, by releasing protective factors Stem cells under trials: - Embryonic SCs - Umbilical cord SCs - Adult neural SCs - Mesenchymal / bone marrow SCs - induced pluripotent Scs Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Christopher Reeve 1952 - 2004 Stem Cells and Neurological Disorders

Paralyzed Patients Walking Again Stem Cells and Neurological Disorders http://www.youtube.com/watch?v=KGUAyKQKmmY http://www.youtube.com/watch?v=-kygF2leZCE http://www.youtube.com/watch?v=ZgI4tm8Tr5M Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders Conclusion: Very promising clinical trial results in the last few years More research needed to optimize diff. SC replacement protocols: - Cell type - Route - No. of cells - Single or multiple cell doses Choice between ESCs / ASCs / iPSCs: yet to be resolved Ethics (ESCs and Fetal tissue): Each Country has to decide Stem Cells and Neurological Disorders

Stem Cells and Neurological Disorders THANK YOU Stem Cells and Neurological Disorders