University of California, Irvine researchers have developed an innovative new stem cell-based therapy that has reversed the symptoms of multiple sclerosis in mice.
While promising stem cell treatments for autoimmune and neurodegenerative disorders have been developed, many have failed during clinical trials or have produced mixed results. One of the problems is too little is known about how the treatments actually work.
UCI researchers conducted a study to investigate the therapeutic mechanisms of transplanted stem cells and the potential for the use of stem cell exosomes for treating autoimmune and neurodegenerative disorders.
Exosomes are tiny extracellular vesicles which contain a range of different molecules that mediate biological functions through gene regulation. They contain anti-inflammatory molecules, neuroprotective RNA, and various protein molecules. Since they are tiny, they are capable of crossing the blood-spinal cord barrier. Exosomes are released from stem cells and can modify the function of receptor cells and tissues, and as such, have considerable therapeutic potential.
One of the problems with using stem cells is they can get trapped in filter organs and fail to reach their targets. Stem cell treatment have potential to result in abnormal differentiation and can even lead to the formation of tumors.
The UCI researchers used exosomes extracted from stem cells and injected them into mice with multiple sclerosis. The researchers found that in rodents with MS, the exosomes decreased nerve damage caused by multiple sclerosis and helped to rejuvenate lost motor skills and normalized the immune system.
Several studies have highlighted the potential benefits of exosomes in regenerative medicine and the UCI study confirms that, in rodents at least, exosomes could be used to get around the problems associated with stem cells. In humans, they could be used as a treatment to reduce the symptoms of autoimmune and neurodegenerative disorders and slow the progression of the diseases.
“These results not only shed light on stem cell therapeutic mechanisms but also provide evidence that [mesenchymal stem cell]-derived exosomes can potentially serve as cell-free therapies in creating a tolerogenic immune response to treat autoimmune and central nervous system disorders,” wrote the researchers.
The researchers are now preparing for clinical trials and will first test the exosome treatment on patients with type 1 diabetes in 2020. Pending the results of that study, further studies on other autoimmune diseases such as multiple sclerosis may follow.
Further information can be found in the paper – Stem Cell-Derived Exosomes as Nanotherapeutics for Autoimmune and Neurodegenerative Disorders – which was recently published in the journal ACS Nano. DOI: 10.1021/acsnano.9b01004