Modelling pathogenesis and treatment of familial dysautonomia using patient-specific iPSCs

Abstract

SUMMARYThe isolation of human induced pluripotent stem cells (iPSCs)1-3 offers a novel strategy for modeling human disease. Recent studies have reported the derivation and differentiation of disease-specific human iPSCs4-7. However, a key challenge in the field is the demonstration of disease-related phenotypes and the ability to model pathogenesis and treatment of disease in iPSCs. Familial dysautonomia (FD) is a rare but fatal peripheral neuropathy caused by a point mutation in IKBKAP8 involved in transcriptional elongation9. The disease is characterized by the depletion of autonomic and sensory neurons. The specificity to the peripheral nervous system and the mechanism of neuron loss in FD are poorly understood due to the lack of an appropriate model system.Here we report the derivation of patient specific FD-iPSCs and the directed differentiation into cells of all three germ layers including peripheral neurons. Gene expression analysis in purified FD-iPSC derived lineages demonstrates tissue specific mis-splicing of IKBKAP in vitro. Patient-specific neural crest precursors express particularly low levels of normal IKBKAP transcript suggesting a mechanism for disease specificity. FD pathogenesis is further characterized by transcriptome analysis and cell based assays revealing marked defects in neurogenic differentiation and migration behavior. Finally, we use FD-iPSCs for validating the potency of candidate drugs in reversing aberrant splicing and ameliorating neuronal differentiation and migration. Our study illustrates the promise of iPSC technology for gaining novel insights into human disease pathogenesis and treatment.

Specification of functional neurons and glia from human pluripotent stem cells

“…In spite of the ethical concerns of hESCs and the current sub-optimized reprogramming methods of iPSCs, these categories of cells are likely more appropriate for industrial production and standardization, thus represent an important source of cells that hold great promise in regenerative medicine. Human iPSCs, in addition, allow for personalized cell therapy through correction of disease gene prior to or following reprogramming patients' cells (Dimos et al, 2008;Ebert et al, 2009;Lee et al, 2009). In any case, a key step toward using these cells for cell replacement therapy is to convert these pluripotent stem cells into functionally specialized cells, such as neurons and glia of the nervous system.…”

Neural stem cells: mechanisms and modeling

“…Disease modeling based on ESC culture is also limited for the same reason (Yamashita et al, 2006;Schneider et al, 2007;Crews et al, 2008). Strikingly, since Yamanaka's and Thomson's exciting experiments on iPSCs in 2007 (Takahashi et al, 2007;Yu et al, 2007), the successful reprogramming of fibroblasts has been accomplished for a variety of neurodegenerative and neurodevelopmental diseases, such as amyotrophic lateral sclerosis (ALS), PD (Dimos et al, 2008;Park et al, 2008;Soldner et al, 2009) Lee et al, 2009), and AD (Israel et al, 2012). The reprogramming of patient fibroblasts to human iPSCs, followed by iPSC differentiation into neurons, produces a near limitless source of live human neurons that are genetically identical to those present in patients, with which the disorder can be extensively studied.…”

“…The SMN gene encodes a 20 kb survival motor neuron protein that plays a role in RNA processing (Bü rglen et al, 1996;Lorson et al, , 1999, and mutations in the SMA protein usually lead to rapid degeneration of motor neurons. FD, which is also an autosomal recessive disease and causes degeneration of sensory and autonomic neurons, not only has been successfully modeled but is also the first neuronal disease that was used for iPSC-based drug screening (Slaugenhaupt et al, 2001;Lee et al, 2009).…”

A novel xeno-free and feeder-cell-free system for human pluripotent stem cell culture

“…Human induced pluripotent stem cells (hiPSCs) not only have the capacity to differentiate into the cell lineages of the three germ layers, but also allow for the generation of disease-specific and patient-specific hiPSCs. Many gene-deficient diseasespecific iPSCs have been derived (Park et al, 2008;Lee et al, 2009;Ghodsizadeh et al, 2010;Somers et al, 2010), and disease phenotypes can be greatly ameliorated by transplantation of gene-corrected iPSC-differentiated cells (Hanna et al, 2007;Wernig et al, 2008;Xu et al, 2009), providing proof of concept for future iPSC-based therapies (Li and Zhou, 2010;Zhang and Gao, 2010). Patient-specific iPSCs should allow the production of genetically-identical cell populations free of immunological rejection when applied in future cell transplantation therapies.…”