Stem Cell Therapy

With the ever-evolving diseases, there is also a need to have advancements in the health care sector with new tools and technology to tackle various serious health conditions. Considering today’s emerging technology, there are indeed great advancements in health care facilities, and Stem Cell Therapy is one of them.

Let’s first understand what are stem cells?

Stem cells are those specialized cells in the human body that can generate into new cells and eventually into an organ. Stem cells are like the raw materials that are used for the regeneration and repair of damaged and worn-out cells of our body. They give rise to specialized and specific cells like blood cells, brain cells, muscle cells, and bone cells.

For example: According to the study conducted, humans shed around 0.03g to 0.09g of dead skin every hour, and these are replaced by new skin through the process of regeneration by stem cells.

STEM CELLS

Location: Stems cells are ubiquitous in the body appearing in the heart, muscles, bones, brain, bone marrow, skin, liver tissues, etc

LOCATION OF STEM CELLS

Types of stem cells

Stem cells are broadly classified into two types:

1. Embryonic Stem Cells: These cells are derived from the inner mass of the blastocyst which is essentially formed after an egg is fertilized by a sperm. During normal development, these inner cells will grow into specialized cells that give rise to the entire body — all of the human tissues and organs and when these embryonic cells are extracted by the scientists and grown into special laboratory conditions they still retain their embryonic properties. Embryonic cells are pluripotent cells which means they can self-renew and develop into three primary germ cell layers, which develop into an early embryo followed by all the adult's cells but not into the placenta and umbilical cord.
2. Adult Stem Cells: Adult stem cells are the undifferentiated cells that can “differentiate” and form more specific cells of the body, they multiply by cell division to replenish and regenerate damaged cells and tissues of the body.

There are two main characteristic features of stem cells, the first being that they can divide or self-renew indefinitely (in case of damaged and worn-out cells) secondly their ability to regenerate all the cell types forming an entire organ.

Induced Pluripotent Stem Cells (iPSCs) are cells that are carefully engineered and reprogrammed under laboratory conditions and are converted to tissue-specific cells, such as skin cells, and behave much like embryonic stem cells. They serve to be a very helpful tool for scientists to develop and test new drug therapies and determine their potency and efficacy.

Stem Cell Therapy in Medicine:

1. Cancer: Cancer is a disease condition wherein there is a loss of normal growth regulation and normal body cell starts dividing indefinitely which leads to excessive cell growth which ultimately leads to tumor due to loss of a programmed cell death process called apoptosis. Chemotherapy is the widely used treatment procedure to curb the spread of cancer and there are certain adverse effects associated with this procedure. Highly energetic radiations destroy certain healthy cells like blood-forming cells and that’s where stem cells find their use. Stem cells are used to replace damaged blood cells and also bone marrow cells which are responsible for the production of blood cells. Patients affected with lymphoma and leukemia are benefitted the most from this therapy.
2. Diabetes: Diabetes is a condition where beta cells of the pancreas are unable to synthesize enough insulin and in some cases, islets cells are destroyed leading to the complete absence of insulin. In such cases, undifferentiated stem cells are used which are specialized to differentiate into a specific type of beta cells and can secrete insulin to regulate blood sugar levels, also they have the potential to replace damaged islet cells.
3. Burns: Burns is one of the most serious public health issues accounting for the highest morbidity and mortality worldwide. It’s a condition wherein the skin is completely damaged, affecting optimum blood circulation and angiogenesis in the affected area. Stem cell therapy aims to tackle some of these pathological complications. Various preclinical studies have been conducted on animals to assess the potential use of stem cells and the studies revealed that stem cells significantly promote wound healing, re-epithelialization, angiogenesis (formation of new blood vessels to supply sufficient blood to the wounded area), inhibition of apoptosis, and regeneration of new skin and appendages at the burned site together with the reduced infection rate has been demonstrated in the human studies.
4. Alzheimer’s Disease: Alzheimer’s is a progressive neurodegenerative disease prominently affecting the hippocampus and frontal lobe of the brain which significantly impairs memory, intelligence, judgment, and behavior. When the stem cells were grafted into the lesioned brain, they exhibited targeted migration to the damaged areas of the brain, where they engrafted, proliferated, and matured into functional cholinergic neurons. It is also observed through studies that when neural precursor cells are injected intravenously, they still migrate to the damaged brain portion and flourish into functional neurons essential for the neuronal conduction of prominent neurotransmitter acetylcholine. Few studies conducted on animal models led to the observation that serves as evidence that both transplanted stem cells or neural precursor cells have the potential to selectively migrate, survive, proliferate, and differentiate into cholinergic neurons, oligodendrocyte, and astrocyte, and ameliorate learning, memory, and other behavioral deficits. In addition to all these functions, they also downregulate pro-inflammatory cytokines (responsible for inflammation), apoptotic neuronal death, and enhance structural neuroplasticity in the brain.
5. Cardiovascular: The heart is one of the most principal organs which performs a complex task to ensure sufficient and continuous blood supply to every cell. Conditions like congestive heart failure (CHF), myocardial infarction (MI), angina pectoris (chest pain), arrhythmia (irregular heartbeat/rhythm), hypertension, etc affects the normal functioning of the heart. In addition to conventional drug therapy, stem cells are the emerging choice of treatment. Besides, the property of stem cells to differentiate into blood-forming cells and replace the damaged myocardial cells, newer studies also suggest that stem cells are also capable of releasing growth factors. Mononuclear cells and Mesenchymal stem cells are the larger groups of stem cells. MNCs are more likely to have regenerative and vascular proliferative properties, and MSCs are involved in triggering favorable forms of inflammation.

Drawbacks of Stem Cell therapy:

Every treatment comes with certain drawbacks and stem cell therapy is no miracle.

Considering the fact, that stem cells are still in the scrutiny phase, still, scientists have to investigate a lot more about the safe use and potential advantages of stem cells in medicine and there is a need to establish firm evidence regarding the effectiveness of stem cell therapy.

• The major drawback of SCT is host vs graft rejection which accounts for most of the incidences of SCT failure. Because, the transplanted cells are not part of the body and thus, the body treats these stem cells as foreign and elicits a strong immune response to protect the host from any harm which ultimately leads to the rejection of the transplanted stem cells and in turn the complete failure of the treatment procedure (Immunosuppressants are administered to prevent the rejection).
• There are high chances of transmission of any genetic disease from the donor’s stem cells to the host.
• Most of the time, induced pluripotent cells are used to induce the growth of healthy cells but they are not as potent as embryonic stem cells.
• Stem cells may emerge to be the reason for tumor growth due to their property to divide and multiply which can be responsible for the cancer sort of condition.

Ethical Concerns:

Human embryonic stem cells (hESCs) are the cells derived from the inner mass of the blastocyst i.e. the implanted embryo. To obtain these cells, a human embryo needs to be destroyed which means destroying a potential human life.

To surmount this issue, researchers introduced an alternative to ESCs to harvesting induced pluripotent stem cells (iPSCs) which are harvested under laboratory conditions mimicking the human body environment.

Future Prospects:

Stem cell therapy is indeed an emerging and promising branch of medicine with a few factors which need to be delved on. It finds its potential applications to be used for the study of new drugs’ effectiveness and potency for which we normally use animal models and as regenerative medicine for the treatment of various ailments. Researchers continue to investigate, explore and advance their knowledge about stem cells so that they can be the best alternative treatment in the future.