Real time imaging of human progenitor neurogenesis.

Human neural progenitors are increasingly being employed in drug screens and emerging cell therapies targeted towards neurological disorders where neurogenesis is thought to play a key role including developmental disorders, Alzheimer's disease, and depression. Key to the success of these applications is understanding the mechanisms by which neurons arise. Our understanding of development can provide some guidance but since little is known about the specifics of human neural development and the requirement that cultures be expanded in vitro prior to use, it is unclear whether neural progenitors obey the same developmental mechanisms that exist in vivo.

Functional assessment of human dendritic cells labeled for in vivo (19)F magnetic resonance imaging cell tracking.

Background Aims: Dendritic cells (DC) are increasingly being used as cellular vaccines to treat cancer and infectious diseases. While there have been some promising results in early clinical trials using DC-based vaccines, the inability to visualize non-invasively the location, migration and fate of cells once adoptively transferred into patients is often cited as a limiting factor in the advancement of these therapies. A novel perflouropolyether (PFPE) tracer agent was used to label human DC ex vivo for the purpose of tracking the cells in vivo by (19)F magnetic resonance imaging (MRI).

A high concentration of epidermal growth factor increases the growth and survival of neurogenic radial glial cells within human neurosphere cultures.

Human neural progenitor cells (hNPC) isolated from the fetal cortex can be expanded as aggregates of cells termed neurospheres. Traditional methods have used 20 ng/ml epidermal growth factor (EGF) to drive the proliferation of these cells. Here, we show that 100 ng/ml EGF can significantly increase growth rates of hNPC at later passages.

Low concentrations of extracellular FGF-2 are sufficient but not essential for neurogenesis from human neural progenitor cells.

Secreted soluble growth factors have long been implicated in regulating or modulating cortical neurogenesis through stimulation of neurogenic progenitors. How a cortical progenitor cell interprets the growth factor signal may determine the progeny produced by the progenitor through a critical final round of cell division prior to terminal differentiation. Given that low concentrations of fibroblast growth factor 2 (FGF-2) have previously been shown to stimulate cortically derived rodent progenitors to produce neuroblasts, we hypothesized that low levels of FGF-2 may also promote neurogenesis from human neural progenitor cells (hNPC).

Glutamate enhances proliferation and neurogenesis in human neural progenitor cell cultures derived from the fetal cortex.

Excitatory amino acids such as glutamate play important roles in the central nervous system. We previously demonstrated that a neurosteroid, dehydroepiandrosterone (DHEA), has powerful effects on the cell proliferation of human neural progenitor cells (hNPC) derived from the fetal cortex, and this effect is modulated through NMDA receptor signaling. Here, we show that glutamate can significantly increase the proliferation rates of hNPC.

Human retinal progenitor cells grown as neurospheres demonstrate time-dependent changes in neuronal and glial cell fate potential.

The spatiotemporal birth order of the seven major classes of retinal cells is highly conserved among vertebrates. During retinal development, long projection neurons (ganglion cells) are produced first from resident progenitors, followed by the appearance of retinal interneurons, photoreceptors, and Muller glia. This sequence is maintained through the complex orchestration of cell-intrinsic and cell-extrinsic events and factors, including local influences between neighboring cells.