Muscles – BioQuakes

Have you ever felt sore after a workout? Maybe your muscles ache and you wonder why this is so? This soreness you are feeling is the result of the tearing of muscles fibers in your body. But the muscle repairing process isn’t as simple as “rebuilding muscles fibers.” It is a part of a chain of reactions and processes that our body triggers in perhaps the most fantastic biological response.

After an intense workout, your muscles are covered in microscopic tears. The easiest and most simple explanation for muscle growth is when you tear these fibers, they grow back stronger leading to stronger muscles. However, a newer study found the presence of scars surrounding the torn muscle fibers. I was totally shocked to learn that after we workout, we get mini scars on our muscles and not just fiber tears. As it turns out, bunches of nuclei go to the scars and begin to heal them. They trigger the release of mRNA which reads the DNA to make new proteins. Who knew that nuclei had something to do with the regeneration of muscles. However, the process of re building a torn muscle fiber is much more extensive than nuclei creating new proteins.

When we dive deeper we can see that there are many different levels to this process. The primary area of rupture after a workout are to the skeletal muscles. Skeletal muscles are laid out in sheets and are connected to bones by tendons. This type of muscle is responsible for a process called protein synthesis. When your body is undergoing an exercise, your muscles are constantly fed protein in order for the cells within your muscles to continue functioning properly and at a proper pace. When your workout concludes, it is vital to consume protein since protein stimulates and accelerates muscle repair and growth. For example, I consume a protein filled meal generally very soon after I workout, making sure I am getting the proper nutrients I need to help my muscles strengthen and prosper. The process of protein synthesis is imperative to muscle recovery and stamina, but if we look even closer into the recovery process we can see a couple of cellular organelles performing some impressive things.

According to the new study, two of the most important organelles in animal cells that is necessary for muscle regeneration is the mitochondria and the nuclei. The mitochondria’s function within a cell is to perform cellular respiration. Cellular respiration is the process where sugars are broken up into useful energy that can be used by the cell and eventually by the body. As we learned in biology class, the mitochondria ultimately converts the sugar glucose into ATP (Adenosine Triphosphate). ATP is essential for muscle regeneration post workout and during a workout because it is responsible for muscle contraction and movement. Just recently, we have learned that the nuclei also comes to the rescue for torn muscle fibers. Nuclei will arrive at the tear and then increase production for more myofilaments, the basis of myofibers. Traditionally, myofibers are the building blocks for muscle growth and rejuvenation. These myofilaments are consisted of small proteins that stimulate muscle movements. All in all, the addition of nuclei to the muscle rejuvenation process highlights the amount of energy needed by the body to perform these functions, which comes from the mitochondria and ATP.

Within the skeletal muscles are areas of high activity that consist of two main organelles doing most of the work: nuclei and mitochondria. The traditional forms of muscle rejuvenation with the mitochondria go hand in hand with the newest discovery of nuclei. In order for the muscle to rebuild it needs proteins and ATP. With the help of these two organelles, this accelerated process can successfully go through. The next time you get sore after a workout, take a second and admire that your body is hard at work with a task that is nothing short of mesmerizing.

Muscle Regeneration and the Rebuilding of Tissue

By rokhsarscov2

On October 22, 2021

In Student Post

Using a combination of molecular compounds that are commonly used in stem-cell research called Yamanaka factors, researchers found the regeneration of muscle tissue was prevalent among mice. Yamanaka factors are a group of proteins which play a vital role in the creation of induced pluripotent stem cells (cells that have the ability to become any cell in the body), often called iPSCs. They control how DNA is copied for translation into other proteins and are used to convert specialized cells, like skin cells, into more stem-cell-like cells that are pluripotent.

Myogenic progenitor cells, also known as satellite cells or myoblasts, possess the ability to differentiate into large multinucleated myotubes (muscle fibers) to provide a cell culture model of mature skeletal myofibers. “Loss of these progenitors has been connected to age-related muscle degeneration,” says Salk Professor.

The primary role of these progenitor cells is to replace dead or damaged cells. In this way, progenitor cells are necessary for repair after injury and as part of ongoing tissue maintenance. Using the combination of Yamanaka factors to create these special muscle building tissues will allow for muscle repair to be quicker, easier, and available to everyone. This will allow any cell to be turned into a muscle repair cell.

In the study, researchers found that adding the Yamanaka factors accelerated muscle regeneration in mice by also reducing the levels of a protein called Wnt4, which then activated the satellite cells to be turned into muscle repair cells. We could potentially use this technology to either directly reduce Wnt4 levels in skeletal muscle or to block the communication between Wnt4 and muscle stem cells.

In our class, we have learned about the different jobs of proteins and how some some of these functions are positive (such as the creation of collagen) and negative to cells. WNT4 in this case researchers analyzed are bad for muscle development in creating structure of muscles but can be stopped with the help of Yamanaka factors. Similar to chaperonins, Yamanaka factors allow for the replication of proteins to be easier by controlling how DNA is copied in these myogenic progenitor cells.

Does long-term endurance training impact muscle epigenetics?

By mitokahndria

On March 8, 2015

In Student Post

Epigenetics translates to “above” or “on top of” genetics. To be more specific, Epigenetics is the study of how modification of gene expression can cause changes in many organisms.

A new study from Karolinska Institutet in Sweden explores the theory that long-term endurance training alters the epigenetic pattern in the human skeletal muscle. The team that conducted the research also explored strong links between these altered epigenetic patterns and the activity in genes controlling improved metabolism and inflammation.

The study was conducted using 23 young and healthy men and women. The men and woman would perform one-legged cycling – where the untrained leg would be the control of the experiment. Four times a week and over the course of three months, the volunteers would participate in a 45 minute training session. Though skeletal muscle biopsies, supervisors would measure their markers for skeletal muscle metabolism, methylation status of 480,000 sites in the genome, and activity of over 20,000 genes.

At the end of the study, the researchers concluded that there was a strong relationship between epigenetic methylation and the change in activity of 4000 genes in total. Epigenetic methylation is defined as the “addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. ” Moreover, it was determined that methylation levels increased when involved in skeletal muscle adaptation and the metabolism of carbohydrates. However, methylation levels decreased in regions associated to inflammation.

Furthermore, Carl Johan Sundberg found that “endurance training in a coordinated fashion affects thousands of DNA methylation sites and genes associated to improvement in muscle function and health.” He believes that this determination could be vital to understanding the treatment of diabetes and cardiovascular disease as well as how to properly maintain good muscle function throughout life.

This article relates very much to our work in class as we learn the Molecular Genetics Unit. It connects because we are learning what happens when mutations occur in one’s genome and the impacts those mutations have on someone. For example, cancer is one of the most researched and explored topics in regard to how modification of gene expression alters organisms. Oncogenes and Tumor suppressor genes have vital impacts on cellular division, changes to cellular function, and the growth of tumors.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Muscles

Muscle Regeneration: More Than Just “Tearing Muscle Fibers”

Muscle Regeneration and the Rebuilding of Tissue

Does long-term endurance training impact muscle epigenetics?

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