Application of Stem Cell Therapy in Spinal Cord Injuries

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Abstract

Adult mesenchymal stem cells are multipotent cells isolated from bone marrow and have the capacity to differentiate into various cell types such as Chondrocytes, Adipocytes, Osteocytes and Cardiomyocytes. The prime function of these bone marrow stem cells in adult tissue is to repair and regenerate the tissues that have been damaged. Stem cells find its major application in the treatment of spinal cord injury, cardiac disorder and in diseases such as cancer and Parkinson’s Syndrome.The clinical data of the patients who have undergone stem cell therapy for spinal cord injury were recorded.

Stem cells were isolated from bone marrow using FACS (Fluorescence- Activated Cell Sorter) which employs specific markers such as CD34+, CD45+ and CD133+. These isolated cells were rejuvenated, concentrated and then injected into the patient intrathecally by Lumbar puncture. The patients were then monitored for improvements by neurological tests such as SSEP (Somato sensory evoked potential) and Urodynamic Study.The thus obtained data were analyzed based on the following parameters: a) Age of the patient b) Level of injury and c) Duration of injury. From the above analysis, it was inferred that younger patients showed better improvement. Similarly, patients with lower level, fresh injuries showed better progression.

Stem cells have the potential to develop into mature cells that have characteristic shapes and specialized functions, such as heart cells, skin cells, or nerve cells. Research in human stem cell field grew finding by Canadian scientists Ernest A.McCulloch and James E. Till in the 1960’s. The implementation of stem cell therapy for curing various diseases was a major technological accomplishment. This therapy is not only a remarkable effective life saving method, but this technology opened the way for the succession of other important therapy for dangerous diseases.

Stem cells are smart cells of the human body. Thus they can normally differentiate into other organ cells. They are normally present in the bone marrow, with small quantities in the blood, crown of tooth, eye. They also move towards injured areas of the body. They are a great value in the regeneration of damaged organs. Stem cells are harvested from the bone marrow or by drawing patients own blood and hence known as Autologous. Stem cells are different from adult body cells having a capacity to change themselves into any type of body tissues like bone, heart muscles, nerve tissues, liver cells, blood vessels, etc. This property is known as Pluripotency or Plasticity.

Applications of Stem Cells

The use of stem cells to generate replacement tissues for treating neurological diseases is a major focus of research. Spinal cord injury, multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease are among those diseases for which the concept of replacing destroyed or dysfunctional cells in the brain or spinal cord is a practical goal. Future uses of human pluripotent cell lines might include the exploration of the effects of chromosomal abnormalities in early development. This might include the ability to monitor the development of early childhood tumors, many of which are embryonic in origin. Another future use of human stem cells and their derivatives include the testing of candidate therapeutic drugs. Although animal model testing is a mainstay of pharmaceutical research, it cannot always predict the effects that a developmental drug may have on human cells. Stem cells will likely be used to develop specialized liver cells to evaluate drug detoxifying capabilities and represents a new type of early warning system to prevent adverse reactions in patients. The coupling of stem cells with the information learned from the human genome project will also likely have many unanticipated benefits in the future.

Types of Stem Cells

• Adult stem cell, which are found in adult tissues.

• Embryonic stem cell, Derived from Blastocysts.

• Cord blood Stem cells, which are found in the umbilical cord.

Stem cells are one of the most fascinating areas of biology today. Stem cells have the remarkable potential to develop into many different cell types in the body as illustrated in the figure 3. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell. They are unspecialized cells that renew themselves for long periods through cell division. Under certain physiologic or experimental conditions, they can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas.

Stem Cells in the Bone Marrow and Blood

The notion that the bone marrow contains stem cells is not new. One population of bone marrow cells, the hematopoietic stem cells (HSCs), is responsible for forming all of the types of blood cells in the body. HSCs were recognized as stem cells more than 40 years ago. Bone marrow stromal cells - a mixed cell population that generates bone, cartilage, fat, fibrous connective tissue, and the reticular network that supports blood cell formation—were described shortly after the discovery of HSCs. The mesenchymal stem cells of the bone marrow also give rise to these tissues, and may constitute the same population of cells as the bone marrow stromal cells . Recently, a population of progenitor cells that differentiates into endothelial cells, a type of cell that lines the blood vessels, was isolated from circulating blood and identified as originating in bone marrow. Whether these endothelial progenitor cells, which resemble the angioblasts that give rise to blood vessels during embryonic development, represent a bona fide population of adult bone marrow stem cells remains uncertain. Thus, the bone marrow appears to contain three stem cell populations—hematopoietic stem cells, stromal cells, and (possibly) endothelial progenitor cells (Hematopoietic and Stromal Stem Cell Differentiation shown in figure 6). Two more apparent stem cell types have been reported in circulating blood, but have not been shown to originate from the bone marrow. One population, called pericytes, may be closely related to bone marrow stromal cells, although their origin remains elusive

Conclusion

The study was carried out on spinal cord injured patients, who underwent autologous stem cell therapy. Adult stem cells (ASC) were isolated from bone marrow using Ficoll paque method and Lyse wash method. A layer of mononuclear cells (MNC’s) were obtained. These separated MNC were sorted in FACS using CD34 and CD45 as markers (CD34- hematopoietic stem cell marker; CD45-White blood cell marker). As a result of this sorting process, a rich population of adult stem cells was obtained, which was injected back into the patient through lumbar puncture. Comparative studies were made on 50 spinal cord injured patients based on three parameters (1) age of injury, (2) age of the patients and (3) level of injury. Analytical methods such as SSEP and Urodynamic studies were performed to support these studies. It was concluded that younger patients, patients with lower level of injury and patients with fresh injury showed better progression and improvement. It was also analysed that besides these conditions, the overall recovery rate also depends upon the patient’s body condition. When compared to neurological surgeries, Stem cell therapy has shown great promise in the treatment of spinal cord injury.

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