Gene expression

This Is What Happens to Your Body When You Exercise

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Story at-a-glance

  • One of the key health benefits of exercise is that it helps normalize your glucose, insulin, and leptin levels by optimizing insulin/leptin receptor sensitivity
  • Exercise-improved insulin/leptin receptor sensitivity is perhaps the most important factor for optimizing your overall health and preventing chronic disease
  • Exercise also encourages your brain to work at optimum capacity by causing your nerve cells to multiply, strengthening their interconnections, and protecting them from damage
  • Unexpected side effects of exercise include improved sexual function, changes in gene expression, clearer skin, and improved mood and sleep
  • Research shows that the “secret” to increased productivity and happiness on any given day is a long-term investment in regular exercise, and a little each day appears to go further than a lot once or twice a week.

One of the key health benefits of exercise is that it helps normalize your glucose, insulin, and leptin levels by optimizing insulin/leptin receptor sensitivity. This is perhaps the most important factor for optimizing your overall health and preventing chronic disease.

exercise-benefits

But exercise affects your body in countless other ways as well—both directly and indirectly. Here, however, even the most unexpected side effects are almost universally beneficial. For example, as illustrated in the featured article,1 side effects of exercise include but are not limited to:

What Happens in Your Body When You Exercise?

The featured article in Huffington Post2 highlights a number of biological effects that occur, from head to toe, when you exercise. This includes changes in your:

    • Muscles, which use glucose and ATP for contraction and movement. To create more ATP, your body needs extra oxygen, so breathing increases and your heart starts pumping more blood to your muscles.

Without sufficient oxygen, lactic acid will form instead. Tiny tears in your muscles make them grow bigger and stronger as they heal.

    • Lungs. As your muscles call for more oxygen (as much as 15 times more oxygen than when you’re at rest), your breathing rate increases. Once the muscles surrounding your lungs cannot move any faster, you’ve reached what’s called your VO2 max—your maximum capacity of oxygen use. The higher your VO2 max, the fitter you are.
    • Heart. As mentioned, your heart rate increases with physical activity to supply more oxygenated blood to your muscles. The fitter you are, the more efficiently your heart can do this, allowing you to work out longer and harder. As a side effect, this increased efficiency will also reduce your resting heart rate. Your blood pressure will also decrease as a result of new blood vessels forming.
    • Brain. The increased blood flow also benefits your brain, allowing it to almost immediately function better. As a result, you tend to feel more focused after a workout. Furthermore, exercising regularly will promote the growth of new brain cells. In your hippocampus, these new brain cells help boost memory and learning. As stated in the featured article:

“When you work out regularly, your brain gets used to this frequent surge of blood and adapts by turning certain genes on or off. Many of these changes boost brain cell function and protect from diseases such as Alzheimer’s, Parkinson’s or even stroke, and ward off age-related decline.”

A number of neurotransmitters are also triggered, such as endorphins, serotonin, dopamine, glutamate, and GABA. Some of these are well-known for their role in mood control. Exercise, in fact, is one of the most effective prevention and treatment strategies for depression.

    • Joints and bones, as exercise can place as much as five or six times more than your body weight on them. Peak bone mass is achieved in adulthood and then begins a slow decline, but exercise can help you to maintain healthy bone mass as you get older.

Weight-bearing exercise is actually one of the most effective remedies against osteoporosis, as your bones are very porous and soft, and as you get older your bones can easily become less dense and hence, more brittle — especially if you are inactive.

Your Brain Health Is Directly Related to Exercise

A related article published by Lifehacker.com3 focuses exclusively on brain-related changes that occur when you exercise. While I just mentioned that neurotransmitters, chemical messengers in your brain, such as mood-boosting serotonin, are released during a bout of exercise, that doesn’t account for all the benefits your brain reaps.

“If you start exercising, your brain recognizes this as a moment of stress. As your heart pressure increases, the brain thinks you are either fighting the enemy or fleeing from it. To protect yourself and your brain from stress, you release a protein called BDNF (Brain-Derived Neurotrophic Factor). This BDNF has a protective and also reparative element to your memory neurons and acts as a reset switch. That’s why we often feel so at ease and like things are clear after exercising,” Leo Widrich writes.

Simultaneously, your brain releases endorphins, another stress-related chemical. According to researcher MK McGovern, the endorphins minimize the physical pain and discomfort associated with exercise. They’re also responsible for the feeling of euphoria that many people report when exercising regularly.

Scientists have been linking the benefits of physical exercise to brain health for many years, but recent research4, 5 has made it clear that the two aren’t just simply related; rather, it is THE relationship. The evidence shows that physical exercise helps you build a brain that not only resists shrinkage, but increases cognitive abilities. Exercise encourages your brain to work at optimum capacity by causing your nerve cells to multiply, strengthening their interconnections, and protecting them from damage. There are multiple mechanisms at play here, but some are becoming more well-understood than others.

The rejuvenating role of BDNF is one of them. BDNF activates brain stem cells to convert into new neurons. It also triggers numerous other chemicals that promote neural health. Further, exercise provides protective effects to your brain through:

  • The production of nerve-protecting compounds
  • Improved development and survival of neurons
  • Decreased risk of heart and blood vessel diseases
  • Altering the way damaging proteins reside inside your brain, which appears to slow the development of Alzheimer’s disease

Both Fasting and Exercise Trigger Brain Rejuvenation

Growing evidence indicates that both fasting and exercise trigger genes and growth factors that recycle and rejuvenate your brain and muscle tissues. These growth factors include BDNF, as just mentioned, and muscle regulatory factors, or MRFs.

These growth factors signal brain stem cells and muscle satellite cells to convert into new neurons and new muscle cells respectively. Interestingly enough, BDNF also expresses itself in the neuro-muscular system where it protects neuro-motors from degradation. (The neuromotor is the most critical element in your muscle. Without the neuromotor, your muscle is like an engine without ignition. Neuro-motor degradation is part of the process that explains age-related muscle atrophy.)

So BDNF is actively involved in both your muscles and your brain, and this cross-connection, if you will, appears to be a major part of the explanation for why a physical workout can have such a beneficial impact on your brain tissue. It, quite literally, helps prevent, and even reverse, brain decay as much as it prevents and reverses age-related muscle decay.

This also helps explain why exercise while fasting can help keep your brain, neuro-motors, and muscle fibers biologically young. For more information on how to incorporate intermittent fasting into your exercise routine for maximum benefits, please see this previous article. Sugar suppresses BDNF, which also helps explain why a low-sugar diet in combination with regular exercise is so effective for protecting memory and staving off depression.

This Is Your Brain on Exercise

BDNF and endorphins are two of the factors triggered by exercise that help boost your mood, make you feel good, and sharpen your cognition. As mentioned by Lifehacker, they’re similar to morphine and heroin in their action and addictiveness—but without any of the harmful side effects. Quite the contrary! So, how much do you have to exercise in order to maintain a sunnier disposition and better memory long-term?

According to a 2012 study6 published in the journal Neuroscience, the “secret” to increased productivity and happiness on any given day is a long-term investment in regular exercise. And a little each day appears to go further than a lot once or twice a week.

“Those who had exercised during the preceding month but not on the day of testing generally did better on the memory test than those who had been sedentary, but did not perform nearly as well as those who had worked out that morning,” the authors note.

The reasons for this can perhaps be best perceived visually. Take a look at these images, showing the dramatic increase in brain activity after a 20 minute walk, compared to sitting quietly for the same amount of time.

There is a minor caveat, however. The researchers also discovered that exercise does not affect the brains of all people in exactly the same way. Some people, about 30 percent of people of European Caucasian descent, have a BDNF gene variant that hinders post-exercise BDNF production. The people with this BDNF variant did not improve their memory scores, even when exercising regularly, as significantly as those without this variant. Still, the research clearly suggests that—with individual variations as to the degree—regular exercise will cumulatively enhance your memory and other brain functions.

You Don’t Need to Train Like an Athlete to Reap the Benefits of Exercise

If you are sedentary there is hope for you. In her book, The First 20 Minutes: Surprising Science Reveals How We Can Exercise Better, Train Smarter, Live Longer, New York Times bestselling author Gretchen Reynolds addresses the issue of exercise as a way to improve longevity and happiness as well.7

“The first 20 minutes of moving around, if someone has been really sedentary, provide most of the health benefits. You get prolonged life, reduced disease risk – all of those things come in in the first 20 minutes of being active,” she said in a 2012 interview8.

“Two-thirds of Americans get no exercise at all. If one of those people gets up and moves around for 20 minutes, they are going to get a huge number of health benefits, and everything beyond that 20 minutes is, to some degree, gravy. That doesn’t mean I’m suggesting people should not exercise more if they want to. You can always do more. But the science shows that if you just do anything, even stand in place 20 minutes, you will be healthier.”

Similarly, research9 published in 2008 found that those who exercised on work days experienced significantly improved mood on days that they exercised. Interestingly, while their mood remained fairly constant even on non-exercise work days, their sense of inner calm deteriorated on those days. According to the authors:10

“Critically, workers performed significantly better on exercise days and across all three areas we measured, known as mental-interpersonal, output and time demands.”

Key findings included:

  • 72 percent had improved time management on exercise days compared to non-exercise days
  • 79 percent reported improved mental and interpersonal performance in exercise days
  • 74 percent said they managed their workload better
  • Those who exercised regularly also reported feeling more than 40 percent more “motivated to work” and scored more than 20 percent higher for concentration and finishing work on time

But remember, it is FAR better to exercise regularly. I believe it is also vital to engage in regular movement if you have a sitting job like most of us do, including me. I typically sit in front of a computer for more than 12 hours a day. What I have recently appreciated is that standing up every 10 minutes (with the help of a timer) and engaging in some type of brief exercise, is an enormously powerful habit to minimize the damage of long term sitting.

Aim for a Well-Rounded Fitness Program

Ideally, to truly optimize your health, you’ll want to strive for a varied and well-rounded fitness program that incorporates a wide variety of exercises. As a general rule, as soon as an exercise becomes easy to complete, you need to increase the intensity and/or try another exercise to keep challenging your body.

Additionally, more recent research has really opened my eyes to the importance of non-exercise movement. Truly, the key to health is to remain as active as you can, all day long, but that doesn’t mean you train like an athlete for hours a day. It simply means, whenever you have a chance to move and stretch your body in the course of going about your day—do it!

And the more frequently, the better. Everything from standing up, to reaching for an item on a tall shelf, to weeding in your garden and walking from one room to another, and even doing dishes count. In short, it’s physical movement, period, that promotes health benefits by the interaction your body gets with gravity. To learn more about this important aspect of health, please see this previous article. That said, I recommend incorporating the following types of exercise into your program:

    • Interval (Anaerobic) Training: This is when you alternate short bursts of high-intensity exercise with gentle recovery periods.
    • Strength Training: Rounding out your exercise program with a 1-set strength training routine will ensure that you’re really optimizing the possible health benefits of a regular exercise program. You can also “up” the intensity by slowing it down. For more information about using super slow weight training as a form of high intensity interval exercise, please see my interview with Dr. Doug McGuff.
    • Stand Up Every 10 Minutes. This is not intuitively obvious, but emerging evidence clearly shows that even highly fit people who exceed the expert exercise recommendations are headed for premature death if they sit for long periods of time. My interview with NASA scientist Dr. Joan Vernikos goes into great detail why this is so, and what you can do about it. Personally, I usually set my timer for 10 minutes while sitting, and then stand up and do one legged squats, jump squats or lunges when the timer goes off. The key is that you need to be moving all day long, even in non-exercise activities.
    • Core Exercises: Your body has 29 core muscles located mostly in your back, abdomen and pelvis. This group of muscles provides the foundation for movement throughout your entire body, and strengthening them can help protect and support your back, make your spine and body less prone to injury and help you gain greater balance and stability.

Foundation Training, created by Dr. Eric Goodman, is an integral first step of a larger program he calls “Modern Moveology,” which consists of a catalog of exercises. Postural exercises such as those taught in Foundation Training are critical not just for properly supporting your frame during daily activities, they also retrain your body so you can safely perform high-intensity exercises without risking injury.

Exercise programs like Pilates and yoga are also great for strengthening your core muscles, as are specific exercises you can learn from a personal trainer.

  • Stretching: My favorite type of stretching is active isolated stretches developed by Aaron Mattes. With Active Isolated Stretching, you hold each stretch for only two seconds, which works with your body’s natural physiological makeup to improve circulation and increase the elasticity of muscle joints. This technique also allows your body to repair itself and prepare for daily activity. You can also use devices like the Power Plate to help you stretch.

A Small RNA That Promotes Lung Cancer.

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Gene expression in both healthy and cancerous tissues is controlled by a wide array of regulatory molecules including a group of small RNA molecules known as microRNAs. New research, performed by Ethan Dmitrovsky and colleagues, at Dartmouth Medical School, Hanover, now provides evidence that the microRNA miR-31 promotes lung cancer by repressing the expression of a number of tumor suppressor genes (i.e., genes that generate proteins that suppress the development of cancer).

The initial series of experiments conducted in the study indicated that miR-136, miR-376a, and miR-31 were all overexpressed in mouse and human malignant lung tissue compared with paired normal tissue. Importantly, knockdown of miR-31 expression repressed the in vitro growth of mouse and human lung cancer cell lines and reduced the in vivo tumorigenicity of mouse lung cancer cell lines.

Further analysis provided a potential mechanism by which modulation of miR-31 expression levels could affect lung cancer cell growth: miR-31 repressed expression of the tumor-suppressor genes LATS2 and PPP2R2A. As miR-31 and these target genes were inversely expressed in human lung cancers, the authors conclude that their data has clinical relevance and that miR-31 promotes lung cancer by repressing expression of specific tumor suppressors.

Source: http://www.sciencedaily.com

 

 

TIP30 Inhibits Lung Cancer Metastasis, Study Suggests. Researchers in Shanghai, China suggest that TIP30 prevents metastatic progression of lung cancer.

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Researchers in Shanghai, China suggest that TIP30 prevents metastatic progression of lung cancer.

They report these findings in the May 2009 issue of The American Journal of Pathology.

TIP30 is a putative tumor suppressor with decreased expression in numerous cancers including melanoma, breast cancer, and colon cancer. Lung cancer is the most common cancer worldwide, both in terms of incidence and of mortality.

To determine if TIP30 plays a role in lung cancer progression and metastasis, Tong et al examined TIP30 expression in paired cancerous and non-cancerous lung tissue. TIP30 expression was decreased in a third of non-small cell lung cancers compared with normal controls, and reduced TIP30 expression correlated with lymph node metastasis. In addition, inhibition of TIP30 expression promoted lung cancer metastasis and angiogenesis in mice,

Tong et al conclude that “TIP30 may function as a tumor suppressor gene and play important roles in suppressing the progression and metastasis of lung cancer.” These findings highlight TIP30 as a potential new therapeutic for metastatic lung cancer.

They report these findings in the May 2009 issue of The American Journal of Pathology.

TIP30 is a putative tumor suppressor with decreased expression in numerous cancers including melanoma, breast cancer, and colon cancer. Lung cancer is the most common cancer worldwide, both in terms of incidence and of mortality.

To determine if TIP30 plays a role in lung cancer progression and metastasis, Tong et al examined TIP30 expression in paired cancerous and non-cancerous lung tissue. TIP30 expression was decreased in a third of non-small cell lung cancers compared with normal controls, and reduced TIP30 expression correlated with lymph node metastasis. In addition, inhibition of TIP30 expression promoted lung cancer metastasis and angiogenesis in mice,

Tong et al conclude that “TIP30 may function as a tumor suppressor gene and play important roles in suppressing the progression and metastasis of lung cancer.” These findings highlight TIP30 as a potential new therapeutic for metastatic lung cancer.

Source: http://www.sciencedaily.com

 

How to Regrow a Head.

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A single gene switch makes worms regenerate their whole bodies from their tails

Knocking out a single gene can switch on a worm’s ability to regenerate parts of its body, even enabling it to grow a new head. The fact that such a simple manipulation can restore healing abilities provides new insight into how the stem cells involved in this process are marshaled in animals.

how-to-regrow-a-head_1

Some animals, such as salamanders and newts, can regenerate entire body parts, and mice can regrow toes if left with enough nail (see ‘How nails regenerate lost fingertips’). Yet other species, including humans, merely produce scar tissue after an amputation. A trio of studies published on Nature’s website today offers new clues as to what is behind these differences.

All three studies looked at Wnt genes, which code for a series of enzymes that relay information from outside the cell to the nucleus, eventually producing proteins called β-catenins, which regulate gene expression. Wnt genes occur in all animals, but the studies looked at their roles in planarian flatworms. Some planarians can completely regenerate from small body parts such as their tails, whereas other flatworm species have more limited regenerative abilities.

Flatworm, heal thyself
Scientists already knew that the Wnt genes are expressed in a gradient along the worms’ bodies—from high at the tail to low at the head—and suspected that the genes were involved in directing stem cells during healing. In the latest studies, researchers wanted to find out if a lack of Wnt gene expression was responsible for the poorer regenerative abilities in particular worm species.

When these species are sliced apart at a point more than halfway to their tail ends, they can regenerate a tail from the head piece, but the tail section is unable to form a new head. However, if the wound is closer to the head—not more than about one-third of the way from it—then both parts will fully regenerate.

To explain the disparity, Jochen Rink, a molecular biologist at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, sliced a worm called Dendrocoelum lacteum at different positions along its body. He and his team then sequenced RNA from the various wounds. The researchers found that, in wounds that did regrow heads, genes coding for a series of enzymes involved in the Wnt pathway had their expression turned up. But in the pieces that couldn’t regrow, the Wnt genes “didn’t even twitch”, Rink says.

In the second study, developmental biologists Phillip Newmark of the University of Illinois at Urbana-Champaign and James Sikes (now at the University of San Francisco in California) found similar roles for Wnt genes in a different species of worm, called Procotyla fluviatilis.

But perhaps most surprisingly, both teams found that by suppressing a gene that regulated Wnt function in their flatworms, they could get chunks of the normally non-regenerative tissue to grow fully functional heads.

“This is a fantastic advert for our field,” says Aziz Aboobaker, a biologist who studies planarian worms at the University of Oxford, UK, but was not involved in any of the studies. “Here’s a scenario where these animals don’t regenerate a brain, and then by knocking out just one gene, it’s possible to rescue that.”

Heady stuff
In the third study Yoshihiko Umesono, now at the University of Tokushima in Japan, and colleagues found that in the flatworm Phagocata kawakatsui, another signaling cascade—the extracellular signal-related kinase (ERK) pathway—had apreviously unsuspected role in regeneration.

In an e-mail to Nature, Umesono suggests that the effects of ERK proteins and Wnt proteins counteract each other. If the Wnt pathway dominates then it signals tail growth, but if ERK suppresses its influence then heads can form.

Because Wnt and ERK proteins are present in all animals, Rink suggests that regenerative capacity could exist in many species, but might be in a latent state because it is silenced. Once the silencing is removed, regeneration could reappear, he thinks.

“Sure, that’s a possibility,” says Aboobaker. But he thinks that the implications are broader than just worms regrowing heads.

“What’s happening here is that cells are reading their position in the body and then rebuilding the requisite structures,” Aboobaker says. “That’s also what happens when cells from your liver or kidney replace themselves—if we can understand those processes better, that’s useful.”

Source: http://www.scientificamerican.com

Acid Suppression and Effectiveness of Ampicillin for Helicobacter Pylori.

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At a low pH, H. pylori bacteria stopped dividing, making ampicillin ineffective. More sustained acid suppression might be useful for refractory infections.

Standard therapy for treating Helicobacter pylori infection typically includes ampicillin, a second antibiotic, and a proton-pump inhibitor (PPI). However, the effectiveness of this regimen has been decreasing with increasing antibiotic resistance. Because ampicillin acts on bacterial cell walls and requires actively dividing bacteria to be effective, investigators examined whether H. pylori growth — and, consequently, ampicillin effectiveness — was affected by gastric pH level.

H. pylori were incubated in dialysis chambers with 5 mM urea and varying pH levels with or without ampicillin for 4, 8, or 16 hours. Changes in the expression of genes associated with bacterial growth, viability, and survival were determined.

Ampicillin was bactericidal at pH levels of 4.5 or 7.4, but at a pH level of 3.0, the bacteria seemed to become dormant, with decreased expression of a host of genes associated with cell envelope biosynthesis. In this environment, ampicillin did not affect bacterial viability or survival.

The authors suggest that PPIs are associated with nocturnal acid breakthrough that might reduce the pH level, rendering ampicillin ineffective, and that more persistent acid reduction could potentially improve the clinical effectiveness of amoxicillin therapy.

Comment: This paper provides a compelling argument for the importance of PPI therapy in antibiotic treatment of H. pylori. It further suggests that sustained acid reduction should be the goal to improve the effectiveness of ampicillin or other drugs that require bacterial growth. The frequency of nocturnal acid breakthrough is likely overstated, and the ability of PPI therapy to maintain a pH of 4.5 is likely better than the authors suggest. The decreasing eradication rate is associated with antibiotic resistance, often to the second antibiotic (e.g., clarithromycin). Knowing the patterns of antibiotic resistance in a population will allow for more effective therapy. In refractory cases, higher PPI doses to sustain a high pH might be a reasonable approach to optimizing the effectiveness of the antibiotic that requires active cell growth.

Source: Journal Watch Gastroenterology

Choline In Eggs And Meat May Influence Gene Expression From Infancy To Adulthood .

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Folic acid is perhaps the most well known B vitamin, and is especially important for pregnant women to avoid certain birth defects.

Now researchers have highlighted the importance of another member of the B vitamin complex – choline – which they say may one day be recommended for all pregnant women, the way folic acid is today.

What is Choline?

Choline is an essential nutrient your body makes in small amounts, however you must consume it through your diet to get enough. In adults, choline helps keep your cell membranes functioning properly, plays a role in nerve communications, prevents the buildup of homocysteine in your blood (elevated levels are linked to heart disease) and reduces chronic inflammation.

In pregnant women, choline plays an equally, if not more, important role, helping to prevent certain birth defects, such as spina bifida, and playing a role in brain development.

Prior research has concluded that choline intake during pregnancy “super-charged” the brain activity of animals in utero, indicating that it may boost cognitive function, improve learning and memory, and even diminish age-related memory decline and the brain’s vulnerability to toxins during childhood, as well as conferring protection later in life.1

It’s recommended that pregnant women consume 450 milligrams of choline a day, but the new study found this may not be enough…

Double the Recommended Amount of Choline During Pregnancy Protects Baby from Stress, Metabolic Disorders and More

The new research, published in The FASEB Journal,2 found the consumption of 930 mg of choline in the third trimester of pregnancy was linked to a 33 percent lower concentration of the stress hormone cortisol, compared to those who consumed 430 mg a day.

It’s known that babies exposed to high levels of cortisol in utero, such as might occur if a woman is under extreme stress, facing anxiety or suffering from depression, have an increased risk of stress-related and metabolic disorders. The researchers believe the beneficial impact of choline on lowering cortisol may protect the baby later in life from mental health conditions, high blood pressure and type 2 diabetes.

Interestingly, the higher choline intake led to changes in epigenetic markers in the fetus. Specifically, it affected markers that regulate the hypothalamic-pituitary-adrenal (HPA) axis, which controls hormone production and activity. The higher intake of choline contributed to a more stable HPA axis, which in turn meant lower cortisol levels in the fetus. The changes in fetal genetic expression will likely continue into adulthood, where they play a role in disease prevention.

Epigenetic Changes May Last for Generations

One of the most intriguing aspects of epigenetics is that these changes are often passed down through generations. This was first shown by the research of Francis M. Pottenger, Jr., M.D., who conducted studies on cats in the 1930s. He found that cats fed a healthy, raw-food diet thrived, while those fed on a primarily cooked-meat diet developed degenerative diseases – and those changes continued on through three generations.

Each generation of “junk-food” cats got progressively sicker, until they could no longer reproduce and eventually died off completely by the fourth generation.

Just this year, a study on rats showed those exposed to chemicals or foods that raise estrogen levels during pregnancy produce daughters that have a higher than normal risk for breast cancer – and that risk is passed on to the next two generations.3 It was not genetic mutations that were passed on, but rather epigenetic alterations that modulate the expression of your genes, similar to what was found in the FASEB Journal study.

You Have the Ability to Change Inherited Epigenetic Alterations

The good news about all of this is that even if you inherited a certain increased disease risk from your mother or grandmother (or you think you passed one on to your child), it is not set in stone. As you age, your genome does not change but your epigenome changes dramatically, especially during critical periods of life, such as adolescence. It is influenced by physical and emotional stresses, and lifestyle factors, which, depending on their effects, may either optimize your genetic expression for health or make it favor disease development.

There are literally new epigenetic discoveries being made every day, and it’s becoming quite clear that eating healthy foods is one of the most powerful steps you can take to optimize your genetic expression.

Certain foods, such as broccoli and other cruciferous vegetables, garlic, and onions contain substances that activate tumor suppressor genes and deactivate cancer-associated genes (oncogenes). And now we see that choline appears to influence cortisol production in utero. Your best bet is to take advantage of the many epigenetic influencers in your diet by eating a wide variety of whole foods…

For additional tips, I suggest you read through my comprehensive and recently revised nutrition plan, which will give tools for eating healthy, dealing with stress, and living a lifestyle that will support your epigenetic health.

What are the Best Dietary Sources of Choline?

If you’re currently pregnant, it seems prudent to make sure your diet contains plenty of choline-rich foods, as this will be your primary source of this essential nutrient (most prenatal vitamins do not contain choline). Unfortunately for many vegetarians, animal foods like eggs and meat are some of the best sources of choline, so if you’re a vegan or vegetarian who does not consume any animal foods, you may be at risk of deficiency.

The following chart shows some of the best choline sources to help you choose your foods wisely:4

Food Serving Total Choline (mg)
Beef liver, pan fried 3 ounces 355
Wheat germ, toasted 1 cup 172
Egg 1 large 126
Beef, trim cut, cooked 3 ounces 67
Brussel sprouts, cooked 1 cup 63
Broccoli, cooked 1 cup, chopped 62
Salmon 3 ounces 56
Milk, skim 8 fl oz. 38
Peanut butter, smooth 2 tablespoons 20

 

Source: Dr. Mercola

 

 

 

Turning Genes Up, Not On: A New View of the Myc Protein.

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Acting as an amplifier, the Myc protein may increase the expression of all active genes in a cell.

One of the best studied proteins in cancer research is also one of the most mysterious.

Myc helps control genes involved in cell growth and is associated with many cancers. But, after thousands of studies, researchers still do not know important details about how Myc operates in normal cells and in cancer cells.

Two new studies, however, cast this large body of work in a new light, providing some answers and raising new questions. Myc, the studies found, apparently boosts the expression of nearly all active genes in a cell, rather than activating specific genes.

“Whatever a cell is doing, it will do that more intensely under the influence of Myc,” said Dr. David Levens of NCI‘s Center for Cancer Research, who co-led one study with Dr. Keji Zhao of the National Heart, Lung, and Blood Institute. Both studies appeared in Cell last week.

A New Perspective

Dr. Levens and his colleagues tracked the activity of Myc in white blood cells using molecular “tags.” This approach revealed that Myc does not preferentially interact with any specific gene; instead, the protein is present at nearly every gene that is already expressed.

Using different methods and types of cells, Dr. Richard Young of the Whitehead Institute for Biomedical Research and his colleagues reached a similar conclusion in a second study. “We came to realize that the primary role of Myc is to go to all the genes that are active in a cell and act like a rheostat, turning up their expression,” said Dr. Young.

These are very well done studies, noted Dr. Chi Van Dang, director of the Abramson Cancer Center at the University of Pennsylvania and a Myc researcher who was not involved in the work. “They provide an additional view of how a relatively powerful cancer gene works when it is deregulated.”

We came to realize that the primary role of Myc is to go to all the genes that are active in a cell and act like a rheostat, turning up their expression.

—Dr. Richard Young

But the model, he added, does not account for some well-documented observations about Myc.

“We know, for instance, that Myc inhibits the differentiation of cells,” Dr. Dang said. “So that means that instead of only amplifying the expression of active genes, the protein has to inhibit something in cells. These studies acknowledge that not all active genes are turned up; in fact, up to one-third are repressed.”

Another important question, Dr. Dang noted, is how high levels of Myc might contribute to cancer. “If you crank up Myc to very high levels and it still behaves as an amplifier, does that cause the expression of genes to occur in an imbalanced way and alter  [RNA in a way] that could lead to cancer?” he asked.

These and similar questions could keep researchers busy for a long time, noted the authors of an accompanying editorial. These “seminal” studies provide a first “glimpse of a coherent and holistic view of Myc,” wrote Dr. Gerard Evan and two colleagues at the University of Cambridge in the United Kingdom in the editorial.

This view of Myc suggests there will never be a single transcriptional signature—a set of genes consistently activated by the protein. This is because the activity of Myc depends entirely on the type of cell and which state the cell is in when Myc is activated, according to the new model.

Implications for the Future

If the new results are confirmed, they could have implications for cancer researchers. Drug developers might want to disrupt the cellular machinery involved in the amplification effect of Myc rather than focusing on specific genes, noted Dr. Young.

“If Myc is amplifying all of the active genes in a cell, the idea of targeting just some of those genes appears unlikely to succeed,” he said. “Going after Myc may be more fruitful.” He predicted that the new results could “reinvigorate efforts to drug Myc itself,” though Myc, like other transcription factors, has proven to be an elusive target.

Researchers have been looking for a pathway through which Myc operates for many years. “Our results suggest that Myc will cooperate with any oncogenic process,” said Dr. Levens.

Before launching this study, Dr. Levens wondered whether he could add anything new to the large scientific literature on Myc. He now sees the new model as bringing together and explaining many puzzling and often contradictory observations about the biology of Myc.

“Our study is more integrative than it is novel,” he said. “It’s hard to say something really new about this protein.”

Source: NCI

 

Researchers create the first atlas of gene activity in the human brain.

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An international team of researchers has created a high-resolution, 3-dimensional map of gene expression in human brains, using donated, whole brains from two males and a single hemisphere from a third man’s brain, according to a new study published last week (September 19) in Nature.

The researchers, led by Michael Hawrylycz of the Allen Institute for Brain Science in Seattle, created the atlas by assembling transcription data—collected using DNA microarrays—from around 900 precisely cut brain pieces and overlaying them on MRI brain scans of the donated brains taken before dicing. The maps—freely available online—could help scientists test hypotheses of brain function, disease, and evolution.

“By themselves these data do not hold all of the answers for understanding how the brain works,” Ed Lein, a neuroscientist at the Allen Institute and co-author of the study, told LiveScience. “However, we hope they serve as a catalyst in human brain research for understanding the brain’s complex chemistry and cellular makeup.”

For example, scientists studying particular disorders could use imaging techniques, such functional MRI, to assess brain areas involved, then consult the new atlas to evaluate the genes expressed in those regions, which are displayed by a simple, color-coded guide to show the relative level of gene expression. Currently researchers rely on piecemeal studies of mouse brains for such expression information.

Coauthor Seth Grant of Edinburgh University told BBC News that for brain research to progress it is “essential to understand how it makes all of the genes and where they are expressed in the human brain.”

Source: http://the-scientist.com