Life begins in the nursery. Not the nursery of the hospital or the home. The nursery of the body. When the sperm of the father meets the egg of the mother, they form a single whole cell, the beginning of life for the new individual. This cell divides into two cells, exactly alike. These two cells divide into four cells and those four cells each divide to form eight cells.
In this embryonic “nursery,” all these cells are exactly alike. None of these cells is limited in what they can become. Each of these cells contains all the genetic DNA code to become a liver cell, a kidney cell, a retina cell in the eye, a muscle cell of the big toe, a heart cell, or a lung cell. These cells are called human embryonic stem cells.
As the original eight cells become sixteen, thirty-two, sixty-four, one hundred twenty-eight cells, they begin to differentiate into distinct cell types. Some genetic DNA directions, previously suppressed, are turned on in the “nursery” to form three specific “nurseries” of cell lines: outside layers of the body, middle layers of the body, and inner layers of the body. From these three basic layers, specific organ systems (vascular, neurological, urinary, muscular, endocrine) and their very complex parts form. Some switches are turned off and some switches are turned on in the DNA of these cells as the specialized functions of individual cells develop (beta-cells of the pancreas that produce insulin, rods of the retina of the eye that transmit night vision, automatic nerve cells of the heart that initiate each heart beat) – all from the “nursery” of those original stem cells.
During the growth of a child into adulthood, various specific cell line “nurseries” are busy creating more of themselves – bones grow, muscles grow, the heart grows, the bowel grows – but always with cells like themselves. In the adult human, some cells age and die rather rapidly – skin cells, blood cells, and sexual reproductive cells – and are constantly being replaced by new cells which come from Adult Stem Cell “nurseries” in the bone marrow, the skin, and the gonads which can produce a multitude of the different cell lines within their specific type. The bone marrow Adult Stem Cells can produce all the various types of blood cells – red blood cells, white blood cells, immune cells, megakaryocytes (which produce platelets for blood clotting).
The problem? Adult Stem Cell “nurseries” which create and replace lost cells in multiple body systems (bone marrow, skin, brain, liver, bone) can be damaged. Radiation, chemical exposure (drugs, occupational exposure), viral infections, environmental factors, and lifestyle habits can alter the DNA in these stem cells to produce human cells that don’t function properly leading to cancers (leukemias, glioblastomas), malfunctions (Type I diabetes, HLH, myasthenia gravis, and other auto-immune problems), and mistakes in the genetic code (PNH – rare, sickle cell anemia – common).
When the Adult Stem Cells in the bone marrow “nursery” create cancerous cells, malformed blood cells, or cells that that have missing “parts,” one of the treatments is to wipe out the entire bone marrow “nursery” with radiation or chemotherapy. All the Adult Stem Cell “nurseries” creating the problematic blood cells are gone. So are all the other “nurseries” that were creating other perfectly good blood cell types. This leaves the body with no red cell replacements for carrying oxygen, no white cell replacements for the “soldiers” that attack and destroy toxic invaders, no immune cells to flag and mark invaders for destruction, no cells that make platelets for blood clotting.
The answer? When the “bad nurseries” are all gone, bone marrow from a donor is transplanted into the recipient, placing donor Adult Stem Cell “nurseries” in the bone marrow, “nurseries” without the defect in the previous bone marrow. The new Adult Stem Cell “nurseries” now makes correct blood cells of all the various types. However, for four to six weeks, the person receiving the new bone marrow “nursery” must be protected from every kind of potential invader from the environment by being isolated in a sterile environment until the new “nursery” is up and running – a very risky time in the life of the recipient.
And – the recipient of the new “nursery” always has the potential of all transplant patients – rejection of the new body part by their own immune system. If the person giving the transplant material is a very, very good match genetically to the recipient, the likelihood of rejection decreases markedly.
To date, only stem cell therapy by bone marrow transplant is approved by the professional medical community and the ethics oversight groups as reasonably safe and effective. Other areas have had successful treatment in experimental programs with stem cells of various kinds – brain and spinal cord, muscle, bone, liver, heart, but the rates of tumor formation are higher, rejection rates are higher, and the potential for the new “nursery” to create the wrong kinds of cells is always possible. Caution: Be wary of “cures” promised by charlatans and non-professionals in this field.
The miracles of modern medicine continue to amaze us. We thank God that He has given us the ability to peek into His creation and discover how parts of it work and how we can gently intervene when things go awry – in the “nursery.”