You’re More Like Your Mother Than You Know

May 22, 2015

By Medical Discovery News

Photo of mother and child

While the benefits of breast feeding have been well-documented, scientists were surprised to learn of another one: breast milk contains a mother’s stem cells that become a part of different organs of the baby’s body.

Breast feeding protects infants against infections early in life and reduces their risk of juvenile diabetes, heart disease, and cancer as children. It also helps mothers lose weight after giving birth and lowers their risk of osteoporosis and uterine and ovarian cancer.

In addition, seven years ago scientists discovered the presence of mammary stem cells in breast milk. The mammary gland is unique in its ability to go through different stages in anticipation of producing milk, then a period of milk secretion followed by a return to the non-lactating state. All of this can occur as many times as necessary. This massive restructuring of the breast suggested the presence of stem cells.

Human breast milk contains about 14,000 cells in each milliliter. Most of these are the epithelial cells that are abundant in the breast and cells of the immune system. Some of the cells in breast milk had a molecule called nestin on the surface, which in adults is a marker for multipotent stem cells that can develop into many different types of cells, like those in the brain, pancreas, liver, skin, and bone marrow. When scientists transplanted a single nestin-positive stem cells into the fat pad of a grown mouse, it reconstituted a functional mammary gland. Scientists wondered if such cells were serving the same function in humans.

However, further research revealed quite a surprise. First, they genetically modified mice to produce a protein that makes the cells glow red under fluorescent light. Mothers with this new feature were given normal pups to nurse. When they were examined as adult mice, they had cells that glowed red like the mice they had nursed from in their blood, brain, thymus, pancreas, spleen, and kidneys. These cells became functional cells within these organs, so the ones in the brain behaved like neurons and those in the liver made albumin. Based on this experiment, breast milk stem cells travel into the baby’s blood and become functional parts of various organs, at least in mice.

In the laboratory, these stem cells have also shown the ability to differentiate into breast cells that produce milk in a petri dish, as well as bone cells, joint cells, brain cells, heart cells, liver cells, and pancreatic cells that synthesize insulin. In addition, this study may have also discovered a non-invasive, ethical, and sustainable source of multipotent stems.

We don’t yet fully understand the role of these cells in offspring, whether they maintain a tolerance for the mother’s milk, play a role in normal growth and development, or both. Until then, know that your mother is more a part of you than you ever realized.

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Life-Saving Printers

Sept. 27, 2013

By Medical Discovery News

3-D printers have proven capable of creating guns that actually fire bullets, pizza (although there’s no assurance of its taste), and now, livers. 3-D printing technology or stereolithography  has been used to create miniature human livers, the first step toward producing livers and eliminating the long wait for a liver transplant.

3-D printing originated with the invention of the ink jet printer in 1976, which was then adapted to print with materials other than inks in 1984. The first machine to print in 3-D was created in 1992 to make objects by applying layer after layer of material governed by computer. By 2002, engineers and scientists developed methods to print biomaterials and make functional miniature kidneys. Since then, 3-D printers have been used to make cars, robotic aircrafts, blood vessels, jewelry, and even prosthetics.

The miniature livers produced thus far are only one-half of a millimeter thick and four millimeters long. To create them the printer lays down about 20 layers of liver cells called hepatocytes and stellate cells. Hepatocytes are the most prevalent type of cell in the liver and stellate cells are vital in liver regeneration and other functions. The printing also includes cells that line blood vessels in order to create a meshwork of small channels to provide oxygen and nutrients, thereby extending the life of these printed livers. The printer used by Organovo was able to place the cells in precise spatial patterns that resemble the natural liver.

These printed livers function like healthy, natural livers. They produced albumin, which is a protein that helps move many small molecules through the blood, including bilirubin, calcium, progesterone, and medications. It also plays an important role in keeping the fluid in the blood from leaking out into the tissues. They also synthesized cholesterol and detoxified key enzymes called cytochrome P450s that metabolize drugs and toxins to protect the body.

The goal of this research is to eventually print full-sized livers that could be transplanted into those who need them. Currently, over 15,000 people are waiting for a liver, and last year, 1,550 died while waiting for a liver transplant. Liver transplants can be the only option for people whose livers are damaged by alcoholism, infections like hepatitis, clots that block blood flow, autoimmune liver diseases, cancer, birth defects, and genetic disorders. Liver failure causes many health problems including malnutrition, blood clotting, bleeding from the gastrointestinal tract, and jaundice. Because the human body needs a functioning liver, a person experiencing liver failure will die without a transplant.

One of the major challenges to printing full-sized human livers is developing a way to print larger branched networks of blood vessels, as these are absolutely essential to the survival of the printed organ. But medical uses for 3-D printing, such as using it to model facsimiles of patients’ organs in preparation for surgeries, show that this technology has the potential to save lives.  

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