Let’s talk about our body for a little while here, shall we?
Let’s talk about medical care and how we exist even as most of our body experiences degeneration at an average – and totally normal – rate of millions of cells every day. All this, while keeping the concept of simple cell division at bay.
So as to place things into perspective, cells are – as everyone would agree – the origin of life. Contextually and more specifically with respect to the human body, most cells only rob this accomplishment from the abundant stem cells present in every individual all the way since they were a more controversial form of being, i.e., an embryo.
Tracing cell lineages, the adult human body is formed as a result of specific role allotment to a bunch of cells that were produced as a result of division from the fused form of an egg and a sperm at the time of fertilization. This job placement procedure is termed as cell differentiation, and will be referred to as it for the rest of the discussion.
Through the various stages of development, the initially small number of cells undergo differentiation to form various kinds of cells that further constitute the nervous, digestive, respiratory, circulatory systems whereas the others (relatively short lived) constitute the placenta. The amazing ability for a cell that can develop both ways – i.e., exhibit the possibility of forming either the placenta or the embryo – is termed as totipotency. And like all living forms, these cells carry their own genetic material as well.
The cells that form the placenta serve a different function than those that form the embryo (called the inner cell mass) and therefore have a different genetic make-up. The former contains genes like CDX2 and the latter contains OCT3/4. These genes along with other intrinsic and environmental factors aid the differentiation process of cells. Ergo it would be legitimate to credit the functional human body’s existence to a bunch of embryonic cells that perform generalized functions before they begin displaying the quality of pluripotency, by the virtue of which they assume different morphological forms of existence with specific complementary functions.
However, it is important to note that once cells of the inner cell mass have undergone differentiation, they almost always lose the power of pluripotency. Which is why, a blood cell remains a blood cell throughout its lifetime.
So what are stem cells and where do they come into picture?
These are cells originating from the inner cell mass that continue to remain undifferentiated throughout the lifetime of the individual. However, they come into picture at 3 primary stages of life. First would be the embryonic stage, the second adult stage and the third would be induced pluripotency stage. Out of these three stages, the third one is conditional in nature and is only possible when an abandoned embryo intended to form a test tube baby is donated by the consent of the donor as a source of stem cells.
Contrary to popular belief, stem cell therapy is only a small portion of all the functions the variety of stem cells in our body perform. Their main function is to keep us ALIVE AND KICKING (certainly literally) through the natural course of regular degeneration of the body. So it would be fair to state that without stem cells, our lifetime would have cut short by several folds.
Except that, without these stem cells our origination from an embryo would have been entirely IMPOSSIBLE in the first place.
In order to aid the visualization of the concept better, picture embryonic stem cells as an entire clump of cells. And as the embryo develops into the well differentiated body of an adult, some of the stem cells developed from their parent embryonic stem cells are scattered across the various tissues of the body – including blood.
An important feature of these cells is their self-renewal capacity, that is, they can divide and make copies of themselves indefinitely. This enables them to expand their presence beyond the embryo and allows them to prevail in the adult human body just as well.
To place things into perspective, without their self-renewal capacity, we would last an average of four days AT THE BEST – since it is the adult stem cells that are responsible for replacement of the degenerated inner lining of the small intestine that takes place at the mentioned pace. Even worse news would have me bring in our blood cells. Haematopoietic stem cells (adult stem cell type) replace exhausted RBCs on a daily basis.
Sometimes, the very stem cells that are responsible for renewal are also harnessed for transplant of lost tissues or organs. This is in turn termed as stem cell therapy and forms the basis of a very important branch of futuristic medical care called regenerative therapy.
But why do we need to shift away from the traditional forms of medical care anyway?
Well that is because everyone has an individualistic body and requires very unique medical care even though the general protocol of treatment might appear to be the same. In order to personalize the care and treatment received during medical procedures, to use the body’s own cells as healing factors would find application. These healing factors are nothing but the body’s own stem cells.
For instance, consider administering stem cell therapy for treatment of leukaemia. Leukaemia is a degenerative disease of the bone marrow (site for synthesis of blood cells) where an uncontrollably dividing mass of cells (termed as proliferating tissue) eat into the space of healthy stem cells, causing a deficiency of them. These stem cells are actually required to differentiate into and form the blood cells we require to breathe and more importantly, survive. Therapy therefore involves transmitting or injecting the patient’s own stem cells from either of the 3 aforementioned sources into the site of deficiency, thereby treating/curing it.
This, I hope, has busted at least one of the several stereotypes and stigmas associated with stem cells being chemically and artificially developed in unnatural environments. They’re not evil, and they’re certainly not conditioned to propagate as a medium for transmission of unnatural ideals. They’re actually pretty cute. Give them a chance!
Author: Aastha Munjal (firstname.lastname@example.org) Date of Publishing: 24th Apr 2017 Artwork by University of Wisconsin-Madison