In vitro differentiation of hESCs into corticospinal motor neurons

In vitro differentiation of hESCs into corticospinal motor neurons

Funding Type: 
SEED Grant
Grant Number: 
RS1-00170
Award Value: 
$465,624
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
Status: 
Closed
Public Abstract: 
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive, fatal neurological disease that leads to the degeneration of motor neurons in the brain and in the spinal cord. There are currently 20,000 ALS patients in the United States, and 5,000 new patients are diagnosed every year. Unfortunately no cure has been found for ALS. The only medication approved by the FDA to treat ALS can only slow the disease’s progression and prolong life by a few months in some patients. Thus it is critical to explore other therapeutic strategies for the treatment of ALS such as cell replacement strategy. Because of the ability to generate many different cell types, human embryonic stem cells (hESCs) may potentially serve as a renewable source of cells for replacing the damaged cells in diseases. However, transplanting ESCs directly may cause tumor growth in patients. To support cell transplants, it is important to develop methods to differentiate hESCs into the specific cell types affected by the disease. In this application, we propose to develop an effective method to differentiate hESCs into corticospinal motor neurons (CSMNs), the neurons in the cerebral cortex that degenerate in ALS. We will test whether these CSMNs generated from hESCs in culture conditions can form proper connections to the spinal cord when transplanted into mouse brains. To direct hESCs to become the CSMNs, it is critical to establish a reliable method to identify human CSMNs. Recent progress in developmental neuroscience have identified genes that are specifically expressed in the CSMNs in mice. However no information is available for identifying human CSMNs. We hypothesize that CSMN genes in mice will be reliable markers for human CSMNs. To test this hypothesis we will investigate whether mouse CSMN markers are specifically expressed in the human CSMNs. The therapeutic application of hESCs to replace damaged CSMNs in ALS depends on the ability to direct hESCs to develop into CSMNs. Currently a reliable condition to direct hESCs to differentiate into CSMNs has not been established. We will attempt to differentiate hESCs into CSMNs based on the knowledge gained from studying the development of nervous system. We will achieve this goal in two steps: first we will culture hESCs in a condition to make them become progenitors cells of the most anterior region of the brain; then we will culture these progenitors to become neurons of the cerebral cortex, particularly the CSMNs. We will study the identities of these neurons using the CSMN markers that we have proposed to identify. To apply the cell replacement strategy to treat ALS, it will be critical to test if human CSMNs generated from cultured hESCs can form proper connections in an animal model. We will transplant the CSMNs developed from hESCs into the brains of mice and test whether they can form connections to the spinal cord. When carried out, the proposed research will directly benefit cell replacement therapy for ALS.
Statement of Benefit to California: 
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive, fatal neurological disease that leads to the degeneration of motor neurons in the brain and in the spinal cord. There are currently 20,000 ALS patients in the United States, and 5,000 new patients are diagnosed every year. Unfortunately no cure has been found for ALS. The only medication approved by the FDA to treat ALS can only slow the disease’s progression and prolong life by a few months in some patients. Thus it is critical to explore other therapeutic strategies for the treatment of ALS such as cell replacement strategy. Because of the ability to generate many different types of cells, human embryonic stem cells (hESCs) may potentially serve as a renewable source of cells for replacing the damaged cells in diseases. However, transplanting ESCs directly may cause tumor growth in patients. To support cell transplants, it is important to develop methods to differentiate hESCs into the specific cell types affected by the disease. In this application, we propose to develop an effective method to differentiate hESCs into corticospinal motor neurons (CSMNs), the neurons in the cerebral cortex that degenerate in ALS. We will test whether these CSMNs generated from hESCs in culture conditions can form proper connections to the spinal cord when transplanted into mouse brains. Everyday, 15 people die from ALS. For patients diagnozied with ALS, time is running out very fast. It is critical to explore novel therapeutic strategies for this rapidly progressive and fatal disease. The research proposed in this application may provide the basis for a novel cell replacement therapy for ALS, thus it will greatly benefit the State of California and everyone in the State.
Progress Report: 

Year 1

Corticospinal motor neurons are affected in motor neuron diseases and damaged in spinal cord injuries. In this grant application, we proposed to induce human embryonic stem cells to generate corticospinal motor neurons. In this past grant period, we have generated neurons that express the corticospinal motor neuron genes. We are currently characterizing the cell types of theses neurons in detail. In the near future we will transplant them into the brains in mice to test whether they can form functional neural circuits.

Year 2

In the past grant period, we have been continuing to generate brain neurons from cultured human embryonic stems. We have been determining what types of neurons are generated using our protocol. We are testing the functions of these neurons.

© 2013 California Institute for Regenerative Medicine