Category Archives: News

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Using Gut Enzymes to Transform Blood Type

In Canada, the average wait time to receive an organ transplant, like a kidney is almost five years. I have an uncle in Ontario who was diagnosed with kidney disease in 2008 and waited almost 8 years for a kidney transplant.  The delay in this procedure was mainly because he is O type blood, meaning that he could only receive a kidney from donors who also had O type blood. With a lack of organ donors and difficulties in blood type matching the wait for organ transplants could continue to increase.

This year, however, Steven Withers and his research group in the UBC Chemistry department have discovered gut enzymes that can transform any blood type into the universal donor, O type. Scientists have been researching methods to increase the number of blood matches since the 1980’s, especially with the growing population and increased frequency of natural disasters.  Almost half of Canada’s population has O type blood which can be received by all other blood types.  However, O type themselves can only receive blood transfusions from other O types which is exactly where the problem lies.

O Type Blood-Wikimedia Commons

Blood type is determined genetically by antigens, molecules made of protein and  sugars. In the case of blood typing, the antigens are specialized sugar structures attached to the surface of red blood cells. Different blood types have different antigens; for example, those with A type blood have the A type antigens, those with AB blood have both A and B antigens and O type has no antigens. For one to receive a blood transfusion, the blood type of the donor must match that of the acceptor or be O type.

ABO Blood Type-Wikimedia Commons

If the blood type does not match, the body’s immune system will fail to recognize the foreign antigens and attack the newly transfused blood cells which can be a life-threatening response. In emergencies, there is often not enough time to perform a blood test, therefore giving a patient O type blood is the safest and fastest method increasing the overall demand of O type. Converting any type of blood into O type is the key to saving more lives by making transfusions more accessible.

Withers strategy in transforming blood types to O type, was to find enzymes that consumed or cleaved sugars that were similar to the antigens present on red blood cells. To accomplish this he used metagenomics, a type of genetic analysis that samples DNA from millions of microorganisms finding similar environments to the desired enzyme. Withers eventually found enzymes housed in the mucosal lining of the gut that cleaved sugars similar to blood antigens. He cloned these enzymes assessing their efficiency and functionality on actual red blood cells, concluding that they were able to remove all antigens from the surface of the blood cells.

Previously, Withers and his research group isolated different enzymes that seemed to cleave the same sugars, but they were inefficient and inconsistent. Withers is now moving forward with the enzymes applying for patents and hopefully proceeding to clinical trials in the near future, they “hope that one day [they] can eventually render any type of donated blood, tissues or organs, safe for use by anyone regardless of their native blood type.”

While I  believe that this type of research is important, I also think a larger problem lies in the lack of people actually donating blood. In the United States alone, almost 38% of the population is eligible to give blood, but only about 10%  donate on a regular basis. In addition to Withers enzyme, more of the population needs to be aware of the importance of donating blood which I believe would increase the amount of overall donations a year.

-Priya Baichoo

 

Is BPA-Free Safe for Me?

I often find myself gravitating towards products that have labels such as “organic”, “cruelty-free”, “free-range”, etc. stuck to their packaging. It’s comforting to know I am opting for a product that is beneficial to either my health, the environment, or both. That’s why when I’m faced with the option to purchase a water bottle that is BPA-free, versus one that is not, 10 times out of 10 I buy the former. For years now I believed this choice was protecting me from the harmful effects of bisphenol A, a chemical known to disrupt reproduction in mice. Much to my surprise, this belief was shattered by a recent article in Current Biology that revealed that the replacement bisphenols are potentially just as harmful.

BPA-free plastic water bottles – photo from Pixabay

Patricia Hunt, a biologist at Washington State University who first discovered the damaging effects of BPA 20 years ago, has uncovered data that mirrors those findings. This new study shows that BPS, a replacement bisphenol, is causing abnormalities in the eggs and sperm of mice. Essentially, BPA-free plastics could still be causing the same adverse effects in humans that led us to ban BPA so many years ago.

The findings were uncovered much in the same way as the BPA discovery decades ago. While conducting unrelated research, Hunt noticed changes in the data collected from her lab mice. Specifically, she found abnormalities in their eggs and low sperm counts. “Given our previous experience with BPA leaching from polycarbonate cages and water bottles,” states Hunt, “damaged materials were an obvious suspect”.

Upon analysis of the plastic cages that the mice were being kept in, Hunt and her team discovered that the inner surfaces to which the mice were being exposed had traces of BPS. The compound, which has replaced BPA in many household items, was being released from the plastic from everyday wear and tear. Notice the similarities between the two chemicals in the images below.

Chemical structure of BPA – photo from Wikimedia Commons

Chemical structure of BPS – photo from Wikimedia Commons

To further investigate the issue, Hunt designed experimental studies in which mice were exposed to several replacement bisphenols. The effects were observed by looking at the number of DNA points where chromosomes had been reshuffled, known as MLH1 foci. This data was telling as MLH1 foci is indicative of the degree of abnormality. Females who were found to have high numbers of MLH1 foci were producing abnormal eggs. On the other hand, males who had low numbers experienced an increase in cell death during sperm creation.

The thought that plastic, a material that we use daily, could be affecting our reproductive health is extremely concerning. The results from Hunt’s most recent studies are remarkably similar to those seen years ago with BPA and raise the question if bisphenols as a class should be eliminated. I hope an alternative replacement in plastics will soon be discovered so that we can still enjoy the diverse benefits of this material.

Trimming the Fat: Is the Canadian Ban on Trans Fats Justified?

Canadian Minister of Health, Genitte Petitpas Taylor, announced one year ago that Canada would be banning the addition of trans fats in food, and that ban came in effect today. Officials predicted the ban would prevent 12000 deaths from heart disease over the next 20 years.

Heart disease is no laughing matter. According to the Canadian Ministry of Health, “About 1 in 12 (or 2.4 million) Canadian adults age 20 and over live with diagnosed heart disease” and “Every hour, about 12 Canadian adults age 20 and over with diagnosed heart disease die”. So, what can we do to beat heart disease? Exercising, drinking and smoking in moderation, and eating a healthy diet are what any doctor will suggest. When it comes to eating a healthy diet, trans fats are public enemy number 1, but why is that?

Heart plaque – Courtesy Wikipedia Commons

Trans fats contain cholesterol that is carried in the body by proteins. The most common are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). These two lipoproteins bind to cholesterol to make it soluble in water so that it can move around our body. Unfortunately, LDL is also responsible for the plaques in our heart and arteries that contribute to heart disease. Knowing this, it’s a no-brainer to reduce the amount of LDL cholesterol we eat. Trans fats have a high proportion of LDL to HDL cholesterol relative to other fats, so avoiding them is the obvious choice. If you’re worried that your favourite treats will soon be off the shelf, there’s no need to worry.

Krispy Kreme Bacon Cheddar Cheeseburger – Courtesy Clay Caviness of Flicker

Canada has joined a global initiative to reduce trans fats in food, alongside the United States of America and the European Union, and we’re a little late to the party. While our heel-dragging isn’t great for our health, we can at least rest easy knowing that food manufacturers in the USA and the EU have already had time to remove trans fats from their products, so we can keep buying them in Canada without interruption. While some alternatives to trans fats are a little more expensive, we can at least pay with our wallets rather than our health. I’ll raise a doughnut to that.