Stem cells are effective in Parkinson's patients.
2020-06-03
Recently, the United States Daily Health News (HealthDay News) reported a case of "Parkinson's patients improved after receiving the first stem cell treatment." For the first time, scientists use Parkinson's patients' own skin cells to treat this disease, transforming skin cells into key brain cells, and the key role in this is induced pluripotent stem cell technology.
Scientists used the patient's own skin cells to generate induced pluripotent stem cells (iPSC) in vitro, and then differentiated the induced pluripotent stem cells into midbrain dopaminergic precursor cells. After testing, patient-specific dopaminergic precursor cells have the phenotypic characteristics of substantia nigra neurons, and experiments with humanized mouse models have shown that these cells lack immunogenicity.
Subsequently, these cells were implanted into the Parkinson's patient at two-month intervals of 6 months. The transplantation sites were the left and right hemisphere putamen, and the patient did not receive immunosuppressive treatment. Positron emission tomography showed that the graft survived steadily in the patient. After 18-24 months of transplantation treatment, this patient's Parkinson's clinical symptoms tended to stabilize or improve. This study was published in the form of a briefing in the authoritative medical journal "New England Medical Journal" [1].
The patient’s attending doctor said, “It has been two years since the stem cell transplantation treatment, and the patient has not experienced serious side effects. Parkinson’s clinical symptoms have stabilized or even improved.”
"Although the improvement of the condition is moderate, the patient's condition deteriorated quickly before receiving the stem cell transplant, and his condition no longer deteriorated after receiving the treatment." Kim Kwang-soo is a molecular neurobiology at McLean Hospital affiliated to Harvard in Belmont, Massachusetts Director of the Science Laboratory, senior researcher, and one of the principals of this research. "We plan to use this method to treat other patients to verify their effectiveness."
This case gives great encouragement to Parkinson's patients, proving the feasibility and safety of stem cell transplantation.
However, this treatment still needs a long time to explore before it is widely promoted. First of all, it is difficult to popularize this therapy on a large scale, induce the induction of pluripotent stem cells, and differentiate into dopaminergic progenitor cells, which requires very high production routes. Secondly, how to benefit patients by transplantation still needs more practice. In the case, the 69-year-old patient reported that the quality of life indicators improved rapidly shortly after the operation. It does not rule out the possibility of other effects, or the mechanism of how stem cells improve the quality of life of Parkinson's patients in a short period of time needs further exploration.
In addition to iPSC, mesenchymal stem cells can also treat Parkinson's
The pathological feature of Parkinson's disease is the massive death of midbrain dopamine neurons, resulting in a significant decrease in the dopamine content in the striatum, which eventually manifests as motor symptoms such as resting tremor, bradykinesia, muscle rigidity, and posture and gait disorders, sleep deprivation, and dementia. And other mental symptoms. Parkinson's incidence is second only to Alzheimer's disease, and it is the second largest neurodegenerative disease, with an incidence of more than 2% in people over 65 years of age. There are more than 10 million Parkinson's patients in the world, including as many as 3 million in my country, and there are 100,000 new cases every year, and the disease burden is extremely heavy [2].
At present, Parkinson's treatment is mainly to relieve symptoms, there is no cure, and cell transplantation is the most promising treatment for Parkinson's disease. The principle is to increase the level of dopamine by transplanting cells into the striatum or midbrain substantia nigra of Parkinson's patients to achieve the purpose of improving exercise.
In addition to the induced pluripotent stem cells in the above case, the most widely used in clinical studies are mesenchymal stem cells. Mesenchymal stem cells have the advantages of convenient material extraction, easy separation and culture, and autoimmunity without immunogenicity. Preclinical experiments have shown that mesenchymal stem cells have the potential to treat Parkinson's disease, or a potential drug for Parkinson's disease.
Animal studies have found that mesenchymal stem cell transplantation can increase the dopaminergic neurons in Parkinson's model animals and improve the animal's pathological behavior [3]. Mesenchymal stem cells have immunoregulatory functions, can inhibit the activation of microglia, reduce the levels of pro-inflammatory cytokines, promote the autophagy clearance of α-synuclein, reduce the oxidative stress of cells, this anti-inflammatory effect can Effectively protects dopaminergic neurons damaged by inflammation.
According to literature reports, 26 cases of Parkinson's disease were included in the clinical research carried out by the Department of Neurological Intervention at the 208th Hospital of the Chinese People's Liberation Army. Autologous mesenchymal stem cell suspension was transplanted into the posterior cerebral artery and the superior cerebellar artery through a catheter. The unified Parkinson's disease score scale was used to observe the laboratory indicators, clinical symptoms and adverse reactions. It was found that the disease score decreased significantly after transplantation, without adverse effects on liver and kidney function, and no adverse reactions such as fever. This clinical study shows that autologous mesenchymal stem cell transplantation for Parkinson's disease can significantly improve patients' daily activities and motor functions, without side effects, safe and reliable [4].
Outlook
Stem cell transplantation has the potential to treat Parkinson's disease, and the New England Journal case shows that iPSCs transplantation treatment is feasible and safe, and can even block the progression of the disease and improve clinical conditions. The report of this case undoubtedly brought hope to the majority of patients with Parkinson's disease. In recent years, more and more studies have confirmed that Parkinson's stem cell therapy, including mesenchymal stem cells, has clinical application prospects, which shows that the prospect of stem cell therapy for Parkinson's disease is very promising.
