Tag Archives: metabolism

Genes & Body Metabolism: How our Muscles Control Outcomes

The basic human body plan is fairly similar (most have eyes, arms, and legs) but how efficiently our bodies’ function is unique and depend heavily on our genes. Although our brains use a lot of the simple energy compounds (like glucose), our skeletal muscles use 70% of our body’s total energy production such as fats, sugars, and amino acids. All of this energy demand from our skeletal muscles means our body’s metabolism is highly regulated by our muscles. If you want a higher metabolism then you should work out more to gain muscle; this process of muscle formation or repair is a complicated sequence of events requiring hundreds of genes all working together at the right time to promote muscle development. However, if one or many genes do not function properly this sequence of events have inefficiencies that diminish our muscle production capability; for some this means more time at the gym but for others it could lead to diseases like diabetes.

Vera working with her mouse models to better understand how a body’s metabolism is controlled by their genes

Our guest this evening is Vera Lattier (Chih-Ning Chang) who is a PhD candidate in the Molecular and Cellular Biology Program focusing on one gene in particular that orchestrates the muscle formation process at various stages of life development. This PITX2 gene is implicated in regulating the activity of other genes as well as formation of the eyes, heart, limbs, and abdominal muscles during embryonic stages. During later stages of life the amount of skeletal muscle you have dictates your bodies metabolism, and if you are unable to build muscles you tend to have a lower metabolism that encourages excess food to be stored as fat. This is the first step towards obesity and is also a precursor to developing diabetes that affects nearly 26 million people in the United States. Although eating right and exercising can have a substantial impact to your health, if your genes are not functioning correctly poor health may ensue at no fault of the patients.

Vera’s research uses mice as models to better understand this complex interaction between our genes and our body’s metabolism. As part of a decade’s long research through Dr. Chrissa Kioussi’s research lab at Oregon State University they examined the role of this PITX2 gene in three main stages of muscle formation. By mutating the gene to affect it’s expression (effectively ‘turning off’ the gene) during early embryonic formation the mice bodies were unable to effectively create the physical structures for basic bodily functions and they were not viable embryos. When mutating the gene near the time of birth the mice were fully functional at the early stage of life and seemed normal. However, when they grew older they quickly became obese, in fact three times as heavy as the average mice, that lead to fatty liver disease, enlargement of the heart, obesity, and of course diabetes. Vera’s work continues to try and elucidate the mechanisms behind the connection of our genes and our body’s metabolism through structural muscle formation that could help us to identify these limitations earlier and help save lives.

Vera giving presentations to scientific conferences to help people understand the importance of muscle in body metabolism.

There is so much more to discuss with Vera on tonight’s show. You’ll hear about her first experience with a microscope at a young age and how she dreamed of one day becoming an evil scientist (luckily her parents changed her mind). Be sure to tune in for what is sure to be an enlightening discussion on Sunday April 8th at 7PM on KBVR Corvallis 88.7FM or by listening live.

 

Studying skeletal muscle physiology to better understand diseases such as type II diabetes

Harrison in the lab.

Our guest this week on Inspiration Dissemination, Harrison Stierwalt a PhD student in Kinesiology, studies the cellular mechanisms of skeletal muscle physiology. Harrison and other members of the Translational Metabolism Research Laboratory, research the cause of skeletal muscle insulin resistance and how exercise acts against insulin resistance. In particular, Harrison currently studies the activity of a protein called Ras-related C3 botulinum toxin substrate 1, or more commonly known as Rac1. Rac1 plays an important role in the regulation of blood sugar in response to insulin being released from the pancreas following a meal. Insulin is a hormone that triggers the uptake of sugar from the blood stream into skeletal muscle cells where it can be stored or metabolized into energy. In states of insulin resistance, individuals still produce insulin, but eventually insulin resistance leads to chronically increased blood sugar levels. Insulin resistance puts individuals at predisposition for cardiovascular disease, cancer, and type II diabetes. Previous research has demonstrated decreased Rac1 activity in states of insulin resistance but the cause for its decreased activity is unknown.

Harrison working with the oxygraph doing high resolution respirometry (used to measure mitochondrial respiration).

Studying Rac1

The activation of Rac1 causes reorganization of cell components creating “highways” that allow other proteins such as glucose transport 4 or GLUT4 to relocate to the cell membrane and allow sugar from blood to enter skeletal muscle cells for processing. Consequently, Rac1 shows increased activity in response to insulin and exercise promoting the metabolism and storage of sugar in skeletal muscle. Harrison suspects that the dysfunction of Rac1 may play a large role in  insulin resistance, and his lab is looking to better understand the dysfunction of skeletal muscle physiology that may contribute to insulin resistance. To study insulin resistance, Harrison is currently comparing Rac1 activity in skeletal muscle cells and skeletal muscle tissue of lean and obese mice. Learn more about Rac1, GO TO ARTICLE.

Harrison has always been drawn to human health, and is particularly intrigued by how adaptable the human body is. He completed his undergraduate degree and Master’s in Exercise Science at Florida State University. After, he worked as a strength and conditioning coach, testing physical performance. While this work was challenging, Harrison decided to pursue a PhD so that he could ask his own research questions about human health and investigate cellular mechanisms therein.

Harrison encouraging a participant during an exercise test.

With a growing interest in metabolism and physiology, Harrison began looking for Kinesiology PhD programs. He discovered the work of his co-advisors, Sean Newsom and Matt Robinson. For Harrison, Oregon State is a good fit that encapsulates his interested: exercise science, molecular cellular biology, and human health. Harrison is starting the second year of his PhD in the College of Public Health and Human Sciences.

If you are interested in participating in human health research, visit the Newsom-Robinson lab webpage.

Tune in this Sunday September 24 at 7 PM to learn more about Harrison and his research with insulin resistance and sugar metabolism. Not a local listener? No sweat! Stream the show live!

You can also download Harrison’s iTunes Podcast Episode!

Mountain biking at Black Rock in Falls City, Oregon.

Harrison at the peak of South Sister, 2017.