Aparna Khanna

A panel of tests to standardize the characterization of human embryonic stem cells

Human embryonic stem cells offer a renewable source of a wide range of cell types for use in research and cell-based therapies. Characterizing these cells provides important information about their current state and affords relevant details for subsequent downstream manipulation. Prior to considering therapeutic applications, it is crucial that the cells are surveyed at a genetic and proteomic level during the extensive propagation, expansion and differentiation. Hence, a set of characterization tests to measure stem cell stability and identity--genomic, epigenomic and mitochondrial markers, as well as functional measures of utility, need to be developed. Thus, we outline a plan of standard assays that can be afforded by multiple laboratories to unambiguously test the quality of human embryonic stem cells. In this manuscript, we describe a comprehensive characterization of ReliCell hES1, the only human embryonic stem cell line reported from the Indian subcontinent. Our study employs gene expression analysis using quantitative reverse transcription-polymerase chain reaction and microarray, mitochondrial DNA sequencing, microRNA analysis, immunophenotyping and teratoma formation, in addition to demonstrating its capacity to propagate under feeder-free conditions.

Stem cells for the treatment of neurological disorders.

Embryonic stem cells (ESC) are a source of renewable cells, which possess a phenomenal potential to differentiate into a myriad of cell types. Thus, ESCs offer a potentially unlimited supply of cells, which can be deployed in developing cell-based therapies. The in vitro differentiation capacity of ESC into derivatives of the neuronal lineage has been demonstrated and the functionality of the ESC derived neuroprogenitors, upon transplantation into in vivo models has been substantiated. In this review, we discuss various approaches to directing ESC towards neural lineages and protocols for sorting and selection of differentiated progenies. We examine in particular in vitro differentiation of ESC to mid-brain dopaminergic (DA) neurons and glial cells and the potential issues related to the transition to the clinic.

Generation and Transplantation of Dopaminergic Neurons Derived from Embryonic Stem Cells

Human embryonic stem cells (hESCs) can be propagated as undifferentiated cells over multiple passages and thus offer a renewable source of a wide range of cell types for use in research and cell-based therapies. Because of the important roles of dopaminergic (DA) neurons in modulating motor control, and in particular that the selective degeneration of DA neurons in midbrain cause the neurodegenerative disorder Parkinsons disease (PD), there has been significant interest in using hESC-derived DA neurons as a source of cells for drug screening, discovery and transplant purposes. Different strategies have evolved to generate appropriately mature DA neurons that have been purified and/or enriched by one of several selection techniques. In this manuscript we discuss recent results, review the remarkable progress that has been made in the field, and compare these results with those obtained from mouse ESCs (mESCs).