Liverfailure and liver diseases are major health problems worldwide leading to high mortality and also one of the high healthcare costs. Millions of patients die due to liver pathologies and liver diseases every year throughout the world. It’s been now proved that the liver disease can be cured by using stem cells in most of the condition. Scientific literature reveals the role of stem cells in treatment and cure of various diseases like Liver Cirrhosis, End Stage liver Failure, genetic liver disease and also the Livercancer.
The stem cells have the capacity and the ability to renew by them or it can possess special characteristics of regenerating themselves. Because of their ability stem cells can differentiate into any tissue type, they have huge potential in various disease therapies and injuries. Since the stem cell therapy has the immense potential in management of liver failure it can be considered as an alternative for liver transplant. Stem cell therapy can be mediated by either embryonic, induced pluripotent or adult stem cells or by promotion of endogenous regenerative processes with bone marrow-derived stem cells. Ethical issues and concerns make reduce the use of embryonic stem cells as a source to cure liver diseases when compared to adult stem cells
Liver failure is a growing health problem and one of the main causes of death worldwide. Hundreds of millions of patients worldwide are affected with liver pathologies. Liver failure and hepatocellular damage may also leads to death of many patients who are waiting for liver transplantation . Scientists have paid their attention to the field of stem cells, which has helped to understand the pathogenesis of liver disease, and thereby expanding the drug discovery processes, which could be used as an alternative therapy. Liver like cells derived from bone marrow and embryonic stem cells, results in better understanding of the biochemical compounds that are essential in liver development . The most common causes of hepatopathy are alcoholism, chronic hepatitis C and B, nonalcoholic fatty liver disease, autoimmune, and drug-induced hepatic disorders . Accumulation of Cadmium in higher quantity may also leads to liver damage.
Many of these diseased conditions can be prevented or treated either by using precautions and drugs but if they are not treated at proper time, they can lead to liver injury, liver fibrosis and ultimately cirrhosis, portal hypertension, liver failure, and, in some cases, it may also leads to cancer.Disturbance in normal function of liver which leads to illness is known as liver disease. The liver is responsible for many of the critical functions in the body and loss of those functions may leads to damage of the body. Liver is considered to the main metabolizing organ in the body as various kinds of metabolic reactions takes place inside it, Liver disease is also referred to as hepatic disease. The liver is the only organ in the body which easily replace the damaged cells, but if the required cells are lost, the liver may not be able to meet the needs of the body.
Role of Stem cells in Liver Repair
Stem cells are considered as Master cells of the body and they are biological cells found in all multicellular organisms, that can divide (through mitotic cell division) and differentiate into diverse range of specialized cell types and can self-renew to produce more stem cells. There are mainly two types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues . Stem cells can be taken from a variety of sources, including umbilical cord blood, bone marrow etc. Stem cells possess two special properties like:
- The ability of stem cells to go through numerous cycles of cell division while maintaining the undifferentiated state
- The capacity of stem cells to differentiate into specialized cell types.
- These cells responsible for normal tissue turnover.
- these Cells that give rise to regeneration after partial hepatectomy.
- these Cells responsible for progenitor-dependent regeneration.
- these Cells that produce hepatocyte and bile duct epithelial phenotypes in vitro.
- these are transplantable liver-repopulating cells. This review will consider liver stem cells in the context of each definition.
Embryonic stem cells (ESCs) and adult somatic cells can be differentiated into hepatocyte-like cells with potential use in drug testing, bio-artificial livers and transplantation.
Human induced pluripotent stem cells hold great promise for advancements in cell therapy. Researchers have found a way to produce millions of the cells that can be injected into the organ to help regenerate it. The technique involves extraction of cells from skin and blood again converting them back to their original stem cell state and then into liver cells. These cells were then injected into a liver with cirrhosis. The stem cells taken from skin or blood are known as “induced Pluripotent stem cells”.“iPSC” derived liver cells not only can be generated in large amounts, but also can be tailored to each patient, preventing immune-rejection problems which are associated with liver transplants from unmatched donors or embryonic stem cells.
By producing a certain protein, the researchers targeted a gene that protects against inflammation in the liver. The protein gets trapped in the liver, in patients with a gene mutation, and leads to liver cirrhosis and lung emphysema. Making use of “molecular scissors” the scientists were able to cut away the mutated section of DNA from a stem cell and replace it with a corrected version. The stem cells went on to generate liver cells, which contained normal protein levels, indicating that the previously faulty gene was now working normally.
Stem cell therapies for liver disease
Various Therapies and technologies were used to treat liver and also other diseases like neural disorders. Researchers are working more precisely, in order to understand how the liver stem cells could be used to treat patients. To produce new hepatocytes in the laboratory. embryonic stem cells or induced pluripotent stem cells might be used for those patients whose liver has lost the capacity to regenerate. Stem cells are used for transplantation purpose Bone Marrow transplantation is very useful to treat disorders.
Embryonic stem cells and fetal liver stem cells used to treat liver disease: Embryonic Stem Cells and their derivatives might constitute an easily available source to obtain a large number of transplantable cells for regenerative treatments. In contrast to adult liver, Embryonic Stem Cells and fetal liver Stem Cells are thought to be highly proliferative, less immunogenic and more resistant to cryopreservation. the Embryonic stem cells have the Ethical issues and concerns like Embryo destruction and fetal injury to extract the embryonic stem cells as a source to generate new cells in the laboratory
Induced pluripotent stem cells used to treat liver disease: Induced pluripotent stem cells (iPSCs) are embryonic like Stem Cells derived from somatic cells. Theoretically, iPSCs could be obtained from the same patient and used for tissue replacement or gene therapy. Human induced pluripotent stem cells (iPSCs) are a potential source of hepatocytes for liver transplantation to treat end-stage liver disease
Placental and Umbilical cord blood stem cells used to treat liver disease: Placental cells and Umbilical cord blood cells have higher proliferation and differentiation potential than Adipose derived Stem Cells. Several studies indicated that umbilical cord and umbilical cord blood, placenta and amniotic fluid are an easily accessible source of pluripotent Stem Cells, which may be readily available for transplantation. These cells can be extensively expanded without loss of potency and have a broad differentiation potential, since they can generate progenies of all three germ layers. These pluripotent stem cells are capable of liver repopulation in vivo, upon transplantation in animal models.
Adult stem cells are used to treat many other diseases.