Wednesday, February 29, 2012

Why your mother was right about eating your broccoli

We all remember those days in our childhood when vegetables were oh-so-yucky. We'd push them around our plate and would be denied our dessert if we didn't finish them. One of my least favorites was broccoli and cauliflower, yet my mother insisted I needed to eat as many as my age. Well, she was right.
Broccoli and other cruciferous vegetables (such as cauliflower, cabbage, horseradish and turnip, among others) contain a compound known as sulforaphane that works through epigenetics to prevent cancer (Eat Your Broccoli: Another Mechanism Discovered by Which Sulforaphane Prevents Cancer). Epigenetics is the study of how genes are turned on/off or expressed beyond the obvious genetic code. DNA is effected by the addition of methyl and acetyl groups, as well as enzymes known as histone deacetylaces (HDACs). In terms of sulforaphane, it acts as a HDAC inhibitor, and it prevents the deactivation of tumor suppressor genes affected by HDAC.

However, a new mechanism for sulforaphane has been discovered, and it works in conjunction with HDAC inhibition, according to a new study by the Linus Pauling Institute at Oregon State University. Sulforaphane has been seen to provide DNA methylation.
DNA methylation turns off genes, thus it controls what genetic material gets transcribed when cell replicate, as well as the cellular components present inside the cell during cell to cell communication. When working in conjunction with HDAC inhibition, it helps prevent the perturbation of the cell cycle (A perturbation that cancer readily exploits). Disruption of DNA methylation also causes general havoc, such as neurodegenerative disease, cardiovascular disease, and even immune function. 

So mom was right. Eat your broccoli and help your DNA remain methylated and HDAC free!

Original Paper: Anna Hsu, Carmen P Wong, Zhen Yu, David E Williams, Roderick H Dashwood, Emily Ho. Promoter de-methylation of cyclin D2 by sulforaphane in prostate cancer cellsClinical Epigenetics, 2011; 3 (1): 3 

Friday, February 24, 2012

Know your blood type? Think again.

I have not abandoned you, dear readers! Nor has the amazing world of biology had any shortage of wonderful new discoveries! I have simply been away on a European holiday, and was too busy sight-seeing to sit down at my computer.

When I opened up my favorite science websites today, a story popped out at my in less then 20 seconds. Two new blood types, Langereis and Junior (+ or -), have been identified (Blood Mystery Solved: Two New Blood Types Identified). These blood types reside mainly in Japanese populations, as well as in certain European gypsies. As many of you know, the most common blood types are A, B, AB, and O. These refer to the specific proteins found on the surface of your blood cells.

The February issue of Nature Genetics presents a study by Helias et al that identifies two new proteins, ABC6 and ABCG2 (proteins responsible for Langereis and Junior blood types). This is significant as the last blood proteins were discovered ten years ago, and this brings the total surface protein number to 32.
While these two blood types are rare, the proteins have been found to carry cancer drug resistance. This may have large implications in how we prescribe cancer treatments.

You may be surprised to learn that beyond the typical blood types, there are 8 others, which have names such as Duffy, Diego, and Lutheran. Langereis and Junior now will join this list. Knowing the exact blood type is important for transfusions, as well as knowing the compatibility of a fetus with the mother. Rejection makes organ and tissue transplants difficult, as the immune system will attack the "non-self".

I cannot stress it enough how important it is that everyone know their blood type. Transfusions are as common as colds in medicine, especially if trauma is being treated. One does not need an auto-immune attack that could result in death on top of the injuries one is suffering. Please be as aware as you can about your own biology to avoid any unpleasant side effects.

Original Paper:
 Virginie Helias, Carole Saison, Bryan A Ballif, Thierry Peyrard, Junko Takahashi, Hideo Takahashi, Mitsunobu Tanaka, Jean-Charles Deybach, Hervé Puy, Maude Le Gall, Camille Sureau, Bach-Nga Pham, Pierre-Yves Le Pennec, Yoshihiko Tani, Jean-Pierre Cartron, Lionel Arnaud. ABCB6 is dispensable for erythropoiesis and specifies the new blood group system Langereis.

Saturday, February 11, 2012

Some advice for Valentine's day: Save the Best for Last and Always Protect Yourself

Well my dear readers, Valentine's Day is just around the corner. But before you run out the door for flowers and chocolate and sweep your sweetie off their feet, I have some scientific advice from the biological world. You follow these, and I am sure your valentine's day will be awesome.

First piece of advice: Save the best for last.
We all have heard that saying. The best thing should be last. Humans experience pleasure from things that are last, such as the graduation ceremony, the dessert after dinner, or a goodbye hug. A recent study done by University of Michigan psychologist Ed O'Brian was aimed at seeing if this phrase has some psychological truth (What kind of chocolate is best?). And how exactly did he test this? By having participants eat chocolate and rate which one is best (I wish I was in this study!). Participants drew out 5 different flavors of chocolate from a bag. Some participants were told "Here is the next one" until the last piece was drawn. Once the last piece was obtained,  some participants were told "Here is the last one". Participants were then asked to rate which one was the best. Those who were told there was a "last piece" marked it as being the best 65% of the time over those who weren't told there was a last (who marked the last piece as being the best only 22% of the time). So for valentine's day, if you have several surprises/gifts/activities planned, SAVE THE BEST ONE FOR LAST! Have I said it enough?

Second Piece of Advice: Always Protect Yourself
Everyone should be aware of the serious nature of STDs. In July 2011, the CDC released a report of a a strain of gonerrhea that is resistant to cephalosporins, the antibiotic currently being used to treat it. Recently, the New England Journal of Medicine has called for action to prevent this strain from spreading further (Scientists sound alarm over threat of untreatable gonerrhea). According to this article, gonerrhea is the second most communicable disease in the US. The bacterium, Neisseria gonerrhoeae, is already resistant to penicillin, tetracycline, sulfanilamides, and fluorquinolones. SO this Valentine's Day, don't become a victim.  Be smart and protect yourself.
Don't Let Gonerrhea Ruin Your Life

Enjoy your Valentine's Day!
Original Papers:
E. O'Brien, P. C. Ellsworth. Saving the Last for Best: A Positivity Bias for End ExperiencesPsychological Science, 2012; 23 (2)

Gail A. Bolan, P. Frederick Sparling, Judith N. Wasserheit.The Emerging Threat of Untreatable Gonococcal InfectionNew England Journal of Medicine, 2012

Wednesday, February 8, 2012

Getting close to Real Life Skele-Gro? Harry Potter was onto something...

Fans of the Harry Potter books know that in the second book, The Chamber of Secrets, Harry Potter loses his bones when his bumbling professor tries to repair his fracture on the Quidditch field. The school nurse had to use the magic potion, Skele-grow to regrow his bones. This scenario would be great in real life, as bones from severe breaks could be repaired effortlessly.

Skele-gro is a great fiction solution, however, scientists have now developed a "fracture putty" that allows bones to repair themselves faster. A study conducted by Steve Stice through the University of Georgia is aiming at studying the regenerative capacity of large animals (Discovery Uses 'Fracture Putty' to Repair Broken Bone in Days). A major challenge of healing large bone fracture is the ability to both stabilize the defects and induce high levels of proliferation to replace the damaged tissue. Stice's previous study helped answer this challenge by formulating mesenchymal stem cell that were able to survive in the bone environment long enough to initiate proliferation.

To make the "fracture putty", the team used adult stem cells to produce a protein involved in bone regeneration, which was then placed in a gel-like substance. The putty was subsequently injected into rat hind leg fractures. Two weeks later, the rats were observed running and standing on their hind legs (with all the damage healed)! The putty is being tested in pigs and sheep as well. The next steps would be testing it in larger animal models. In terms of human applications, this putty would be very useful in battlefield situations, where a lot of amputations occur because a fracture is too complex or will take a long time to heal.

Ever thought Skele-gro was a stretch? Perhaps, but now it's been replaced with the realities of "fracture putty!" How maddening!


Sunday, February 5, 2012

Here's an excuse to visit your massage therapist!

While we all love the seldom occasion of a great back rub, few of the people I know utilize or go to get a professional massage. Many say it's too expensive, or they can't find time to get to one. Those are some excuses not to go. However, today I have a pretty good reason for you all to head to your favorite massage therapist ASAP.

A new study has revealed that massage regulate DNA expression, particularly down regulating genes associated with inflammation and up regulating healing genes (Massage's Mystery Mechanism Unmasked). Massage has long been thought to squeeze out lactic acid and other cellular waste products, but this study by Mark Tarnolpolsky at McMaster University in Hamilton, Canada contradicts this claim. Tarnolpolsky and colleagues tested the effects of massage by having 11 volunteers perform a grueling cycling session followed by a massage on one leg. Tissue samples were collected before the workout, ten minutes after the massage, and three hours after the workout and their genetic profiles where compared.

There was a clear difference between the massaged legs and unmanaged legs. The massaged legs at a 30% increased expression of PGC1-alpha, a gene that helps cells increase the number of present mitochondria (the energy center of the cell). They also expressed 3 times less NFkB, a gene that turns on the inflammation response. The study found no evidence of removal of lactic acid in the muscles.

This is exciting! This first study legitimizes massage therapy as a scientific treatment, not just a feel good activity. No wonder one feels so good when one gets a full body massage! So today's piece of biology advice: Get to your massage therapist and go often!

Original Paper:
Massage Therapy Attenuates Inflammatory Signaling After Exercise-Induced Muscle Damage

  • Justin D. Crane
  • Daniel I. Ogborn
  • Colleen Cupido
  • Simon Melov
  • Alan Hubbard,
  • Jacqueline M. Bourgeois
  • and Mark A. Tarnopolsky 
  • Sci Transl Med 1 February 2012 4:119ra13

    Thursday, February 2, 2012

    The Lowdown on Mad Cow

    There are several diseases which strike concern in the human population, particularly diseases that are obtained by eating contaminated food (such as Salmonella poisoning) or  that can cross species (such as the flu). They are feared because of their ability to affect a wide number of people. One such disease is Mad Cow (or as my favorite microbiology professor would say, bovine spongiform encephalopathy), a disease that is caused my malformed proteins called prions. This disease can cross species, and a prime example is humans consuming infected cow meat. (To read up on Mad Cow, refer to this link: Mad Cow Disease)

    Prions are malformed versions of the protein PrP. They not only are themselves deformed, but encourage other PrP proteins to malform. The main location of this perturbation is in the brain, with symptoms being observed often when it is to late.  Vincent Béringue from the French National Institute for Agricultural Research is challenging this view. His study has found that prions not only lurk in the brain, but are also found to hide in the lymphatic system (Prions enter stealth mode in the spleen, causing silent infections). In particular, the study has found that the spleen is a gateway organ for species transfer of prions. 

    Species transfer mechanisms have been disputed, as species transfer is rare. It is rare because it is difficult for prions of one species to effectively convert PrP of another species. Béringue's study genetically engineered mice to express sheep prions, then exposed them to prions that cause chronic wasting disease in deer. The mice showed no or little symptoms of disease in the brain, but the spleen was found to have a very high prion content. Béringue also engineered the mice to express human prions and exposed them to the strain that causes bovine spongiform encephalopathy, as this would enable the study of animal to human transition. The results were the same as before, with the spleen containing a high amount of prions while the brain was relatively clean. Signs of disease was non existent, and only 10% of the mice had prions in the brain. 

    This is a very interesting result, as Mad Cow disease could be diagnosed earlier than when symptoms manifest. Once the symptoms are present, often there is nothing that can be done to treat the patient. It shows that the spleen is the gateway organ, and hides within the body. What a "maddening" discovery!

    Original Paper: Béringue, Herzog, Jaumain, Reine, Sibille, Le Dur, Vilotte & Laude. 2011. Facilitated Cross-Species Transmission of Prions in Extraneural Tissue. Science