Investigators are exploring stem cell therapy to treat myriad diseases. Two major areas of focus at Cedars-Sinai are a form of blindness and amyotrophic lateral sclerosis (ALS), a neurological disease. 

Both courses of study are supported by the California Institute for Regenerative Medicine (CIRM), the state-funded stem cell research institute. Collectively, the two promising projects have been awarded more than $20 million.

Retinitis pigmentosa is an inherited eye disease with no known cure. Cedars-Sinai investigators are investigating the use of stem cell technology as a potential treatment for the condition. The work follows many years of favorable preclinical research on the disease.

Retinitis pigmentosa gradually destroys the photoreceptor cells of the retina—the structure in the back of the eye that detects light. The disease, believed to affect more than 80,000 people in the U.S., typically manifests as poor night vision early in life and progresses to legal blindness.

The clinical trial involves injecting a cortical progenitor cell product known as CNS10-NPC into the eye. Progenitor cells, descendants of the body’s stem cells, can make cell types relevant to the eye and brain. In an animal model, these injected cells migrated and provided an environment of protective cells for the diseased photoreceptor cells. These new cells slowed degeneration of the retina and preserved vision.

"In humans, we are looking at safety," says Clive Svendsen, PhD, executive director of the Cedars-Sinai Board of Governors Regenerative Medicine Institute (RMI). "We want to make sure the injections do not have unwanted side effects, such as surgical complications or an immune reaction."

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ALS, or Lou Gehrig's disease, is a progressive neurodegenerative disease that damages cells called motor neurons in the brain and spinal cord that control voluntary muscle movement. It affects an estimated 16,000 people in the U.S. and is usually fatal within five years of diagnosis. As with retinitis pigmentosa, there is no cure, and only limited treatments that may slow progression in some patients. 

Clive's latest ALS project is designed to transplant neural progenitor cells secreting a powerful growth factor (termed GDNF) into the brain cortex of ALS patients. The initial study of 16 patients aims to demonstrate safety and assess preliminary efficacy of using these cells to slow progression of ALS.

"Motor neurons that die in ALS don't exist in a vacuum—they have support cells that enable the motor neurons to live and operate," says Clive.

The neural progenitor cells for the trial can turn into astrocytes, a protective cell type found in the brain, and have been programmed to release GDNF. Astrocytes and GDNF both promote survival of diseased motor neurons. 

In ALS patients, astrocytes may become sick and provide less support to motor neurons, which then die gradually, leading to paralysis. Clive hypothesizes that delivering astrocytes and GDNF locally to the cortex will keep the motor neurons healthy and ultimately slow the progression of ALS. 

The trial builds on many years of research that demonstrates a similar technique that delayed disease progression and extended survival in a rodent model of ALS. The investigators are also analyzing data from a recently completed clinical trial that delivered these same cells into the spinal cords of ALS patients.

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