Stem cells and its application
- 1. Stem cell types and their Application Suprabha panda Asst.prof. of Zoology
- 2. Stem Cell • Stem cell, an undifferentiated cell that can divide to produce some offspring cells that continue as stem cells and some cells that are destined to differentiate (become specialized). Stem cells are an ongoing source of the differentiated cells that make up the tissues and organs of animals and plants. • They have potential in the development of therapies for replacing defective or damaged cells resulting from a variety of disorders and injuries, such as Parkinson disease, heart disease, and diabetes. • There are two major types of stem cells: Embryonic stem cells and Adult stem cells, which are also called tissue stem cells.
- 4. Embryonic stem cell • Embryonic stem cells (often referred to as ES cells) are stem cells that are derived from the inner cell mass of a mammalian embryo at a very early stage of development, when it is composed of a hollow sphere of dividing cells (a blastocyst). • Embryonic stem cells are pluripotent, self-renewing cells that can be derived from both mouse or human blastocysts, they are taken from the very early stages of embryo development after 4-5 days after fertilization . • Embryonic stem cells from human embryos and from embryos of certain other mammalian species can be grown in tissue culture. • They can be stored in culture as undifferentiated cell lines and can be stimulated to differentiate into any cell line. • They can differentiate into endoderm, mesoderm, and ectoderm embryonic germ layers, and also any type of somatic cells. • Applicable in tissue regeneration therapy.
- 6. Embryonic Germ Stem Cells • Embryonic Germ (EG) cells are taken from the later stages of the embryo development cells. They are derived from Primordial Germline Cells (PGCs) in the early development. • They are mainly isolated from the fetal tissue in narrow-window timing . • The PGC-derived cells were pluripotent.
- 7. Fetal stem cells • Fetal stem cells are primal cell types found in the organs of the fetuses. • They are able to differentiate into two types of stem cells: pluripotent stem cells and hematopoietic stem cells. • Neural crest stem cells, fetal hematopoietic stem cells and pancreatic islet cells have been isolated in the fetuses. • Human fetal stem cells have been used by many people, children and adults that are suffering from many of mankind’s most devastating diseases .
- 8. Infant stem cell • Umbilical cord stem cells: Umbilical cord blood contains prevalent stem cells which differ from those of bone marrow and adult peripheral blood . Cord blood stem cells have shown to be multipotent as it being able to differentiate into neurons and liver cells. • Wharton’s jelly: Wharton’s jelly, which is the umbilical cord matrix, is considered to be a source of mesenchymal stem cells. These cells express typical stem cell markers, can be propagated for long times and can be induced to differentiate in vitro into neurons.
- 9. Adult stem cell • Adult stem cells are any stem cells taken from mature tissue; they are found in the tissues of a fully developed child (whole embryo) or adult and can only produce a limited number of cell types. • They have limited potential as compared to the stem cells that derived from embryos and fetuses because of the stage of development of these cells. • They play a vital role in tissue repair, regeneration; and they are referred to their tissue origin . • Bone marrow is an abundant source of adult stem cells. • The adult stem cell can be differentiated into various types basing on their origin. They are…….
- 10. 1. Mesenchymal stem cells: Mesenchymal Stem Cells (MSCs) are a different population of cells with the potential to differentiate into various somatic lineages. They were at first described as adherent cells with a fibroblast-like appearance that can differentiate into osteocytes, chondrocytes, adipocytes, tenocytes(tendon cells) and myocytes (muscle cells). • MSCs can be isolated from the bone marrow and readily discreted from the hematopoietic stem cells due to their plastic adherence. They are used in tissue engineering and regenerative medicine . They are character by long-storage without major loss of their potency .
- 11. Hematopoietic stem cells: Hematopoietic stem cells are cells having the self- renewing potential and the capacity to give rise to differentiated cells of all hematopoietic lineages. Therefore, they transplanted for complete healing of hematologic disorders and after high dose chemotherapy against malignant diseases.
- 13. 3. Neural Stem Cells: Neural stem cells are multipotent and self-replication cells, they are established in specialized molecular microenvironments in the adult mammalian brain. They can display the potential role in cellular therapy of the brain.
- 14. 4. Gastrointestinal stem cells: The stem cells of the gastrointestinal tract reside in a “niche” in the intestinal crypts and gastric glands. The mechanism and the direction of the diffusion of this converted clone in the gastrointestinal mucosa are hotly disputed, and the central to this case is the position and nature of the gastrointestinal stem cells.
- 15. 5. Epidermal stem cells: The mammalian epidermis is a rapidly rejuvenating tissue that consists of three types of keratinocytes with varying differentiation potential: epidermal stem cells, Transiently Amplified Cells (TA cells) and terminally differentiated cells. • The epidermal stem cells have free self-renewal power. They are establishing in the basal layer and remarkable in maintaining homeostasis and cellular regeneration of normal skin; wound healing and neoplasm formation. • Whereas TA cells, progeny of the epidermal stem cells, undergo terminal differentiation after 3–5 divisions. After division, TA cells leave the basal layer and move through the suprabasal layers to the tissue surface, where they are periodically shed as squames .
- 16. 6. Hepatic stem cells: The liver has a strong regenerative capacity, utilizing different modes of regeneration according to the type and extent of the injury. • Mature liver cells can propagate to replace the damaged tissue permit the recovery of the parenchymal function . • Chronic liver injury gives rise to a potential stem cell compartment which is located in the smallest branches of the intrahepatic biliary tree being activated, which is called oval cell ductular reaction. • These oval cells are derived from the canal of Hering, which amplifies this biliary populations prior to these cells differentiate into hepatocytes. • In the human liver, the organization of the biliary tree is different, with the canal of hering extending to the proximate third of the lobule and so apparently requiring a name change from oval cells to hepatic progenitor cells.
- 17. Diagram showing the regenerative cells of liver
- 18. • 7. Pancreatic stem cells: Insulin-producing cells previously generated from pluripotent stem cells. The generation of these cells would provide a novel cell source for drug discovery and cell transplantation therapy in people suffering from diabetes. • Insulin-producing beta-cells turnover every 40-50 days by processes of apoptosis and the propagation and differentiation of the newly islet cells from progenitor epithelial cells, which are located in the pancreatic ducts.
- 19. Types of stem cells according to their differentiation • Stem cells can be classified according to their differentiation potential as a totipotent, pluripotent, multipotent, unipotent and oligopotent . • Totipotent stem cells: Totipotency means that it has the total potential to give rise to all types of cells. Totipotent is the capacity of a single cell to divide and differentiate into all cell types in an organism and produce fertile offspring. Oocytes and sperm are the best differentiated cells in our body and they are capable of forming any tissue in the body. • Pluripotent stem cells: Pluripotency is the ability of the cells to produce any type of cells in the organism. They have been derived from the mouse embryo. All are capable of differentiating into cells representative of a variety of adult tissue types in various assays, including embryonic body, teratoma, and some can contribute to mouse development in chimeras. There are many differences being recognized among pluripotent stem cell types, such as their morphology, gene expression profiles and growth factor requirements
- 20. • Multipotent stem cells: Multipotency means to those cells that can only give rise to cells of the tissue from which they are isolated. Adult stem cell are multipotent cells. • Unipotent stem cell: Adult stem cells are found in the tissues of the adults they produce a limited number of cell types and can repair damaged tissue by replacing specialized cells. Because of their restricted lineage, they were thought to be either multipotent, with the ability to differentiate into a limited range of cells or unipotent, with the ability to produce only one cell type. • Oligopotent stem cells: Oligopotency means to those cells that can differentiate into only a few cell types, like lymphoid or myeloid stem cells.
- 21. Applications Stem cells have already been applied successfully for: • Hematopoietic disorders – Acute and chronic leukemia (AML/ALL or CML/CLL) – Myelodysplastic syndrome – Lymphomas (Hodgkin lymphoma, non-Hodgkin lymphoma) – Aplastic anemia – Sickle cell anemia – Beta thalassemia • Immunodeficiency – SCID – Whiskott Aldrich syndrome • Metabolic disorders – Mucopolysaccharidosis • Cancer - Multiple myeloma - Neuroblastoma
- 22. In clinical studies and treatment attempts, stem cell therapies are tested with the following indications: • Autoimmune diseases – Diabetes mellitus type 1 – Rheumatoid arthritis – Lupus – Crohn’s disease • Graft-versus-host disease (GvHD) • Impairments of the brain – Dementia, in particular Alzheimer’s disease – Stroke – Brain injuries due to accidents or cancer – Infantile brain damage (cerebral paresis) • Cardiovascular diseases – Cardiac infarction • Multiple sclerosis • Amyotrophic lateral sclerosis • Autism • Hearing loss • HIV • Cirrhosis of the liver • Epidermolysis bullosa (“butterfly children”)
- 23. Stem cell therapy • We take two examples for explaining stem cell therapy, they are diabetes and parkinson’s disease. diabetes mellitus: • Stem cells have generated incredible interest for repairing failing tissues and organs. • Stem cell therapy has become a tantalizing idea to provide glucose- responsive insulin-producing cells to Type 1 diabetic patients as an alternative to islet transplantation. • Mesenchymal stem cells will grow and differentiate according to their environment. When MSCs injected into the pancreas in vivo, it is expected that MSCs will differentiate into pancreatic cells that have both exocrine and endocrine functions. Thus, transplantation of MSCs from bone marrow stem cells can repair the pancreas in its role to provide paracrine effects and other cell differentiation effects.
- 25. Parkinson’s disease: • Parkinson’s disease (PD) is a widespread neurodegenerative disease that characterized by bradykinesia, rigidity, and tremor. • The pathological causes of PD are due to the Decrease of Nigrostriatal Dopamine (DA) neurons, but neuronal degeneration also occurs in non-DA-ergic systems. • MSCs are capable of differentiating into tyrosine hydroxylase-positive neurons and can ameliorate motor performance in mice Parkinson’s disease model. Moreover, it has been demonstrated that cells with DA-ergic can be produced from both rat and human MSCs, and that transplantation of these cells showed an improvement of motor function in an animal model of PD.