Stem Cell Therapy of neurodegeneration in ataxia oculomotor apraxia type 2 and cerebellar ataxia
Ataxia oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive cerebellar ataxia. Recent evidence suggests that the protein defective in this syndrome, senataxin (SETX), functions in RNA processing to protect the integrity of the genome.
To date, only patient-derived lymphoblastoid cells, fibroblasts and SETX knockdown cells were available to investigate AOA2. Recent disruption of the Setx gene did not lead to neurobehavioral defects or neurodegeneration, making it difficult to study the etiology of AOA2.
Ataxia treatment with stem cells
Stem cells thery are combined with specialized therapy for ataxia, which not only focuses on helping the patient to cope with their symptoms, but also treats the direct cause of the symptoms, contributing to the healing of traumatic brain injury. We believe that comprehensive approach to ataxia stem cell therapy gives patients a high chance of improvement, allowing them to improve their quality of life.
Stem cell treatment program can be applied to various types of ataxia, including SCA1, SCA2, SCA3, SCA6, AOA1,AOA2, Ataxia Frederick, which is caused by head injury, and much more.
What are the potential improvements in the stem cell treatment?
The goal of the treatment is to heal the brain injury caused by the disease, to restore the neurological function.
There are various types of improvement after our treatment and our past patients had the following *:
Improving balance and coordination
Improved function of the motor apparatus
Decreased neuropathic pain
Improved mental alertness
Agitated atrophy of the brain with MRI.
In recent years, stem cell therapy has become the treatment for such an access point diseases. Mesenchymal stem cells obtained easily by amplification in vitro can be a lot in the long run in vitro. The cultivation process to maintain its pluripotency under certain conditions may be able to differentiate in nerve cells and can secrete a variety of neurotrophic factors, to promote nerve repair of cells. In stem cell therapy, to overcome the acquisition of neural stem cells from adult brain tissues of danger and limitations, but also to avoid fetal brain transplantation in the presence of ethics, immune rejection, limited sources of problems, there is no acute or chronic toxicity and Tumorigenicity in the body can contribute to the repair of damaged nerves.
With the help of stem cell technology and rarely used in a clinical hospital.
Blood or fat tissues among the early autologous mesenchymal stem cells to treat spinal cord injuries and other neurological injuries and achieved positive results. Now investigators use an alternative cord umbilical cord, not only to obtain a sufficient number of mesenchymal stem cells can also be frozen, restoration of the pre-application, a short time to assemble a sufficient number of stem cells used in clinical therapy, even if the patient has removed the extraction of brain pain, but also shortens waiting time for cell culture.
And in clinical practice it proved its reliability and safety, and not an immune response. Clinical application can be obtained from autologous mesenchymal stem cells to treat the same effect.
Cases with cerebellar ataxia symptoms in patients with neurodegenerative diseases of mesenchymal stem cells among the umbilical subarachnoid injection therapy after treatment of patients with motion, balance, language, writing such as the ability to have different recovery levels, improving quality of life, significantly decreased after a large-scale International Ataxia and ADL treatment scores (P <0.05), and no adverse reactions.
More about stem cell therapy of Ataxia and scientific research
Ataxia oculomotor apraxia type 2 (AOA2) was first described 15 years ago and subsequently mapped to chromosome 9.
To develop a more relevant neuronal model to study neurodegeneration in AOA2, investigators derived neural progenitors from a patient with AOA2 and a control by induced pluripotent stem cell (iPSC) reprogramming cells. AOA2 iPSC and neural progenitors exhibit increased levels of oxidative damage, DNA double-strand breaks, increased DNA damage-induced cell death and R-loop accumulation. Genome-wide expression and weighted gene co-expression network analysis in these neural progenitors identified both previously reported and novel affected genes and cellular pathways associated with senataxin dysfunction and the pathophysiology of AOA2, providing further insight into the role of senataxin in regulating gene expression on a genome-wide scale. These data show that iPSCs can be generated from patients with the autosomal recessive ataxia, AOA2, differentiated into neurons, and that both cell types recapitulate the AOA2 cellular phenotype. This represents a novel and appropriate model system to investigate neurodegeneration in this syndrome.
Stem cells with mesenchymal origin are cells initially appearing in the early stages of intrauterine life as cells which differentiate into all other cells. They were also responsible for blood cell production at that early stage. Cells of the different functional systems formed during the fetal phase were stem cells before their transformation. Cells like chondrogenic cells, neurogenic cells, and osteogenic cells come to mind.
This disorder is characterized by progressive cerebellar atrophy, peripheral neuropathy, oculomotor apraxia in ∼50% of the patients and elevated α-fetoprotein levels with an age of onset between 10 and 20 years .
The gene defective in AOA2 was identified as SETX coding for senataxin, a 2667 amino acids protein that contains a highly conserved C-terminal seven-motif domain of the superfamily 1 of DNA/RNA helicases and an N-terminal domain important for protein–protein interactions .
Using lymphoblastoid cells and fibroblasts from AOA2 patients and SETX-RNAi-depleted cells as model systems, roles for senataxin have been uncovered that encompass (i) protection against DNA damage , (ii) transcription regulation including transcription termination, splicing efficiency of specific mRNAs and alternate splice site selection and R-loop resolution and (iii) localization at the interface of transcription and replication .
R-loops are RNA/DNA hybrids that form over transcription pause sites by interaction with an ssDNA template behind an elongating RNA Pol II complex, which are potentially harmful and can cause genomic instability if left unresolved. A role for senataxin in transcription elongation and termination is further supported by a report, showing that cells with senataxin knockdown display an increase in RNA readthrough and RNA Pol II density downstream of the Poly(A) site and also exhibit increased levels of R-loop formation . Senataxin was found to localize to distinct nuclear foci in S/G2 phase cells, and the number of these foci increased in response to impaired replication, suggesting that senataxin localizes to collision sites between the transcription apparatus and components of the replisome .
In addition, a SUMO-dependent interaction between senataxin and Rrp45, a core component of the exosome, was also shown to co-localize in nuclear foci corresponding to sites of R-loops, suggesting that senataxin connects transcription, DNA damage and RNA surveillance .
Generation and characterization of AOA2 iPSC stem cells
In order to optimize conditions and to reduce the risk of chromosomal instability, used early passage (P < 5) fibroblasts for reprogramming. Following transfection with pEP4EO2SCK2MEN2L and pEP4EO2SET2K episomal plasmids, stepwise adapted the cells to knockout serum replacement (KOSR) medium over the first 4–5 days of iPSC generation, as direct replacement with the KOSR medium was found to lead to extensive death of the AOA2 fibroblasts.
After 2 weeks, transduced AOA2 patient and matched control fibroblasts gave rise to colonies of small round cells with a high nucleus-to-cytoplasm ratio typical of pluripotent human stem cells
Although data show that it was possible to reprogram AOA2 fibroblasts, the efficiency was somewhat reduced compared with that of controls. Thirteen colonies from the AOA2 homozygote patient who expressed the TRA-1-60 stem cell surface marker
were expanded for further analysis. Two of these AOA2 clones, AOA2(C7) and AOA2(C8), were selected for further analysis as these clones displayed robust expression of the pluripotency markers TRA-1-60, TRA-1-81, Nanog and Oct4
Control clones were screened similarly as described earlier and conformed to the same criteria. The presence of the c.6109 A>G homozygous missense mutation in AOA2 iPSC was confirmed at the mRNA levels by sequencing , and a normal karyotype was observed for AOA2(C7) and AOA2(C8) iPS clones
OCT4, NANOG and SOX2 expression in the AOA2 iPSC was not derived from integrated or persistent reprogramming plasmids as (i) polymerase chain reaction (PCR) analysis of genomic DNA revealed no amplicons following 36 rounds of PCR using IRES-anchored primers designed to amplify the reprogramming genes OCT4, SOX2, LIN28, KLF4 and c-MYC (plasmids used as positive controls) and (ii) reverse transcriptase (RT)–PCR analysis of RNA isolated from the AOA2 and control iPSC showed an absence of transgene expression (human fibroblasts transiently transfected with the reprogramming plasmids used as a positive control)