Safety and efficacy of human embryonic stem cell-derived astrocytes following intrathecal transplantation in SOD1G93A and NSG animal models

Abstract

BackgroundAmyotrophic lateral sclerosis (ALS) is a motor neuron (MN) disease characterized by the loss of MNs in the central nervous system. As MNs die, patients progressively lose their ability to control voluntary movements, become paralyzed and eventually die from respiratory/deglutition failure. Despite the selective MN death in ALS, there is growing evidence that malfunctional astrocytes play a crucial role in disease progression. Thus, transplantation of healthy astrocytes may compensate for the diseased astrocytes.MethodsWe developed a good manufacturing practice-grade protocol for generation of astrocytes from human embryonic stem cells (hESCs). The first stage of our protocol is derivation of astrocyte progenitor cells (APCs) from hESCs. These APCs can be expanded in large quantities and stored frozen as cell banks. Further differentiation of the APCs yields an enriched population of astrocytes with more than 90% GFAP expression (hES-AS). hES-AS were injected intrathecally into hSOD1G93A transgenic mice and rats to evaluate their therapeutic potential. The safety and biodistribution of hES-AS were evaluated in a 9-month study conducted in immunodeficient NSG mice under good laboratory practice conditions.ResultsIn vitro, hES-AS possess the activities of functional healthy astrocytes, including glutamate uptake, promotion of axon outgrowth and protection of MNs from oxidative stress. A secretome analysis shows that these hES-AS also secrete several inhibitors of metalloproteases as well as a variety of neuroprotective factors (e.g. TIMP-1, TIMP-2, OPN, MIF and Midkine). Intrathecal injections of the hES-AS into transgenic hSOD1G93A mice and rats significantly delayed disease onset and improved motor performance compared to sham-injected animals. A safety study in immunodeficient mice showed that intrathecal transplantation of hES-AS is safe. Transplanted hES-AS attached to the meninges along the neuroaxis and survived for the entire duration of the study without formation of tumors or teratomas. Cell-injected mice gained similar body weight to the sham-injected group and did not exhibit clinical signs that could be related to the treatment. No differences from the vehicle control were observed in hematological parameters or blood chemistry.ConclusionOur findings demonstrate the safety and potential therapeutic benefits of intrathecal injection of hES-AS for the treatment of ALS.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0890-5) contains supplementary material, which is available to authorized users.

Astrocytes in Pathogenesis of Multiple Sclerosis and Potential Translation into Clinic

“…The diverse modes of action of astrocytes may be more effective in treating MS compared to a single pathway-based drug. Transplantation of healthy astrocytes was proven effective in other neurodegenerative diseases such as ALS [137,138]. In ALS animal model, it was shown that intrathecal injections of human astrocytes significantly delayed disease onset and improved motor performance compared to sham-injected animals.…”

“…In ALS animal model, it was shown that intrathecal injections of human astrocytes significantly delayed disease onset and improved motor performance compared to sham-injected animals. In this study, the astrocytes were found to secrete various neurotrophic factors and decrease glutamate neurotoxicity [138]. In spinal cord injury (SCI) model, it was demonstrated that transplantation of human astrocytes promotes functional recovery [139][140][141].…”

Stem Cell Therapy in Motor Neuron Disease

“…A wide variety of preclinical studies show that stem cells migrate to and restore lost function of damaged tissue in ALS/MND. Rodent studies have investigated different cell types such as mouse ES cells differentiated to neurons expressing green fluorescent protein (GFP) under the promoter of the motor neuron (MN)specific gene hb9, mesenchymal stem cells (MSCs), human bone marrow mesenchymal stem cells (hMSCs) obtained from an ALS patient (ALS-hMSCs), human neural stem cells (hNSCs), human cord blood stem cells (HuCB-MNCs), human embryonic stem cell-derived motor neuron progenitors (hMNPs), bone marrow cells (BMCs), mesenchymal stromal (stem) cells (MSCs), human umbilical cord blood (MNC-hUCB), human fetal spinal neural stem cells (hNSCs), human iPSCderived neural progenitors (hiPSNPs), HB1.F3.Olig2 cell (stable immortalized hNSCs encoding the OLIG2 gene)-derived motor neurons, human amniotic mesenchymal stem cells (hAMSCs), glial-rich neural progenitors derived from human iPSCs, enriched population of embryonic stem cell-derived astrocytes (hES-AS), and neural progenitor cells secreting GDNF (hNPC GDNF ) [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79].…”

“…Stem cells also confer neuroprotection by migrating, efficiently engrafting into target tissue, reducing astrogliosis, and differentiating into neuroglial cell types. Further, they improve motor performance as measured on rotarod (test measuring rodent balance, grip strength, endurance, and motor coordination), delay disease pathology, and safely extend survival in ALS rodent models (see Appendix) [20,[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79].…”

Astrocyte-based cell therapy: new hope for amyotrophic lateral sclerosis patients?

“…Izrael and collaborators [ 8 ] developed an original and promising cell therapy approach to ALS using human embryonic stem cell (hESC)-derived astrocytes (hES-AS) [ 8 ]. They show that, after intrathecal transplantation of “young” astrocytes into a murine NSG model, the cells distribute throughout the neural axis and survive for a long time attached to Pia mater, in close proximity to central nervous system parenchyma without penetrating the cellular microenvironment of the grey or white matter.…”