Bad breath plays good role in stem cell research: Dark clouds do have silver linings. In this case, the dark cloud is bad breath, and the silver lining is … stem cell research.
While bad breath remains a scourge for millions the world over, Japanese scientists have recently found a way to make use of it. Or at least, the compound that causes bad breath and ‘farting’ or flatulence, that noxious gas that smells of rotten eggs.
A team from Nippon Dental University in Tokyo found that the major cause of halitosis — hydrogen sulphide (H2S) — could help speed the transformation of stem cells from dental pulp into a type that can be used in valuable treatments for people suffering from chronic liver diseases like cirrhosis of the liver or chronic hepatitis.
The Japanese researchers used the H2S gas to boost the growth of stem cells from one body part to another. In this case, they converted dental pulp — the tooth’s middle part made of tissue and cells — into liver stem cells.
First, the researchers collected stem cells from the pulp of patients undergoing routine extractions. Then, they separated them into two groups: a group incubated in an H2S chamber and a control group.
The dental stem cells were then analyzed after three, six and nine days, to see if they changed into liver stem cells. Researchers tested the new stem cells for how effectively they undertook the functions of liver stem cells:
• the ability to store glycogen that is converted to glucose when the body needs energy
• the ability to collect urea, the by-product of protein metabolism that is transferred by the kidneys from blood to urine.
The researchers claim their study is the first to produce high quality liver stem cells in high numbers and in a safe manner. The findings are published in the Journal of Breath Research.
“High purity means there are less ‘wrong cells’ that are being differentiated to other tissues, or remaining as stem cells,” says lead author Dr. Ken Yaegaki.
“Moreover, these facts suggest that patients undergoing transplantation with the hepatic (liver) cells may have almost no possibility of developing teratomas (tumors) or cancers.”
“Until now, nobody has produced the protocol to regenerate such a huge number of hepatic cells for human transplantation,” they say.
According to Dr. Yaegaki, “compared to the traditional method of using fetal bovine serum to produce the cells, our method is productive and, most importantly, safe.”
The Japanese scientists are hoping their findings would mean that stem cells derived from tooth pulp could be converted to liver stem cells that can help repair damaged liver cells in people with liver diseases. Using stem cell for liver disease would have to wait in the future though.
Power of stem cells
The ability of stem cells to produce new cells of specific types — called their pluripotency — make them a potentially powerful medical tools that could be used to repair or replace diseased or injured tissues or organs in humans.
Research has been done with stem cells from mice or from human adults, as well as human embryos — but the study or use of stem cells derived from these embryos has led to controversy.
Bone marrow transplants are now a standard therapy for certain cancers, such as leukemia and lymphoma, and for other diseases of the blood and bone. Other stem cell therapies in current use involve blood stem cells isolated from drawn blood and taken from umbilical cords.
But there isn’t any proven stem cell treatment for liver disease.
Alternative treatment for liver diseases?
The liver is a robust organ and can tolerate and recover from a certain amount of abuse, for as long as the damage is not too advanced. Usually, though, there are no warning signals until it’s too late.
Unlike the kidney that can be hooked up to a dialysis machine when it’s damaged, there’s no equivalent machine for liver disorders. Patients with chronic liver disease are eventually left with two bleak outcomes — organ transplantation or death.
A transplant operation poses danger to life and the body can even end up rejecting the transplanted organ. Worse, patients don’t even get offered that choice as much as they need: only a few will be deemed suitable for transplant. Worldwide, for every donor organ there are 10 patients on the waiting list.
This is why stem cell treatments for liver diseases are in urgent need.
Skirting the controversy over the use of human embryonic stem cells, an important advance in stem cell research has been the genetic reprogramming of ordinary differentiated cells to act like embryonic stem cells.
In work first published in 2007, viruses were used to insert genetic instructions into human skin cells that made the cells as pluripotent as embryonic stem cells. Using a patient’s own cells to create the reprogrammed equivalents of stem cells would avoid problems with immune system rejection.
But using viruses carries the risk of tumors or cancer — and new method developed by the Japanese scientists of using H2S seems to be a safer way.
Commenting on the research, Dr. Anthony Hollander, head of cellular and molecular medicine at the UK’s Bristol University says: “This is interesting work in a new direction but there’s a long way to go to see if it’s usable therapeutically.”
The real test of a liver cell was whether it could metabolize specific toxins and that would require experiments on enzyme function, The Guardian also quoted him as saying.
This isn’t the first time that health benefits have been found for hydrogen sulphide gas. In 2008, scientists from the John Hopkins University found that small amounts of H2S relaxes blood vessels and lowers blood pressure.