 |
|
Weizmann Institute scientists discover a key player in embryonic muscle development
April 12, 2007Finding may help design new methods for healing muscle tissue using stem cells
Muscle fibers are large cells that contain many nuclei. They begin, like all animal cells, as naive embryonic cells. These cells differentiate, producing intermediate cells called myoblasts that are now destined to become muscle. New myoblasts then seek out other myoblasts, and when they find each other, they stick together like best friends. In the final stage of muscle fiber development, the cell membranes of attached myoblasts open up and fuse together, forming one large, unified cell.
How myoblasts identify other myoblasts and how they cling together had been established, but the way that the cell membranes fuse into one has remained a mystery. Now, a study by Weizmann Institute scientists has shed light on this mystery. The study was carried out by research student Rada Massarwa and lab technician Shari Carmon under the guidance of Dr. Eyal Schejter and Prof. Ben-Zion Shilo of the Institute's Molecular Genetics Department, with help from Dr. Vera Shinder of the Electron Microscopy Unit. The cells' system for identifying other myoblasts and sticking to them consists of protein molecules that poke through the outer cell membrane - one end pointing out and the other extending into the body of the cell. These recognition proteins anchor the cells together, but what makes myoblasts open their doors to each other and merge into one cell?
The scientists discovered that a protein called WIP, which attaches to the internal part of the myoblast recognition protein, plays a key role in muscle cell fusion. WIP communicates between the recognition protein and the cell's internal skeleton, which is made of tough, elastic fibers composed of a protein called actin. The skeletal actin applies force to the abutting cell membranes, opening and enlarging holes that allow the cells to merge. The Weizmann Institute team found that the WIP protein is activated by an external signal once myoblasts identify and attach to each other. Only when it receives this signal does WIP hook the actin fibers in the skeleton up to the myoblast recognition protein, allowing cell fusion to proceed.
The WIP protein has been conserved evolutionarily. In other words, versions of it exist in all animals, from microorganisms such as yeast, through worms and flies, and up to humans. This means that the protein fulfills a function necessary for life but also, say the scientists, because of this conservation, studies conducted on this protein in fruit flies can teach us quite a bit about how it works in humans.
To further examine the role of WIP, the scientists knocked out the gene responsible for producing it in fruit flies. In flies that did not make the protein, normal muscle fibers were not produced. WIP-deficient myoblasts continued to identify and cozy up to one another, but fusion between cell membranes did not take place, and multi-nucleated muscle fibers failed to form. An article describing these findings appears in the April 2007 issue of the journal Developmental Cell.
This study, which improves our understanding of the process of muscle formation, may assist in the future, in devising new and advanced methods for healing muscle. Specifically, these might include ways of fusing stem cells with injured or degenerated muscle fibers.
Fusion between cell membranes plays a key role in development of different kinds of bone cells, placental cells, and immune system cells, as well as in fertilization and in the penetration of viruses into living cells. Understanding how membrane fusion takes place may one day lead to the development of ways to encourage the process when it's needed or hinder it when it's likely to cause harm.
American Committee for the Weizmann Institute of Science
The scientists discovered that a protein called WIP, which attaches to the internal part of the myoblast recognition protein, plays a key role in muscle cell fusion. WIP communicates between the recognition protein and the cell's internal skeleton, which is made of tough, elastic fibers composed of a protein called actin. The skeletal actin applies force to the abutting cell membranes, opening and enlarging holes that allow the cells to merge. The Weizmann Institute team found that the WIP protein is activated by an external signal once myoblasts identify and attach to each other. Only when it receives this signal does WIP hook the actin fibers in the skeleton up to the myoblast recognition protein, allowing cell fusion to proceed.
The WIP protein has been conserved evolutionarily. In other words, versions of it exist in all animals, from microorganisms such as yeast, through worms and flies, and up to humans. This means that the protein fulfills a function necessary for life but also, say the scientists, because of this conservation, studies conducted on this protein in fruit flies can teach us quite a bit about how it works in humans.
To further examine the role of WIP, the scientists knocked out the gene responsible for producing it in fruit flies. In flies that did not make the protein, normal muscle fibers were not produced. WIP-deficient myoblasts continued to identify and cozy up to one another, but fusion between cell membranes did not take place, and multi-nucleated muscle fibers failed to form. An article describing these findings appears in the April 2007 issue of the journal Developmental Cell.
This study, which improves our understanding of the process of muscle formation, may assist in the future, in devising new and advanced methods for healing muscle. Specifically, these might include ways of fusing stem cells with injured or degenerated muscle fibers.
Fusion between cell membranes plays a key role in development of different kinds of bone cells, placental cells, and immune system cells, as well as in fertilization and in the penetration of viruses into living cells. Understanding how membrane fusion takes place may one day lead to the development of ways to encourage the process when it's needed or hinder it when it's likely to cause harm.
American Committee for the Weizmann Institute of Science
Muscle Development News and Current Muscle Development Events RSSLack of time on tummy shown to hinder achievement
The American Physical Therapy Association (APTA) is urging parents and caregivers to ensure that babies get enough "tummy time" throughout the day while they are awake and supervised, in light of a recent survey of therapists who say they've noticed an increase in motor delays in infants who spend too much time on their backs while awake.
Gladstone scientists identify role of tiny RNAs in controlling stem cell fate
Researchers at the Gladstone Institute of Cardiovascular Disease (GICD) and the University of California, San Francisco have identified for the first time how tiny genetic factors called microRNAs may influence the differentiation of pluripotent embryonic stem (ES) cells into cardiac muscle.
Don't move a muscle: Evolutionary insight into myogenesis
In a paper released online ahead of its scheduled December 15th publication date, Dr. Michael Krause (NIH) and colleagues detail the transcription network that drives muscle development in the roundworm C. elegans, and make a strong argument for an evolutionarily conserved program of myogenesis in all animals.
Scientists Show Drug Can Counteract Muscular Dystrophy in Mice
Scientists at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and other institutions have demonstrated for the first time that a single drug can rebuild damaged muscle in two strains of mice that develop diseases comparable to two human forms of muscular dystrophy.
U of MN researchers develop mouse model for muscle disease
Researchers from the University of Minnesota have identified the importance of a gene critical to normal muscle function, resulting in a new mouse model for a poorly understood muscle disease in humans.
Masterminding muscle development
Dr. Lizi Wu (Dana Farber Cancer Institute) and colleagues report on a critical role for one of the three mammalian mastermind genes (Maml1) in myogenesis - assigning that first biological function to the mammalian MAML Notch co-activators.
Stanford/Packard scientist's data-mining technique strikes genetic gold
A new method to mine existing scientific data may provide a wealth of information about the interactions among genes, the environment and biological processes.
Study finds genes that 'fine-tune' muscle development process
Scientists at the University of North Carolina at Chapel Hill have found two genes that are essential for the proper development of muscle.
Discovery of T-cell 'traffic control' boosts new drug promise
Scientists have begun to clarify how one of the body's molecules controls the trafficking of T cells through the blood, lymph nodes and on to tissues to fight infection - a crucial response that sometimes goes awry, attacking the body's own tissues and causing autoimmune diseases.
PE improves self-esteem in schoolchildren
Children at specialist sports colleges may develop significantly higher physical self-esteem compared to those at traditional state schools, according to a new report. The Northumbria University study has revealed that after just one academic year, sports college pupils' confidence had grown about their sporting ability, their physical strength and condition and their physique compared to those at a regular comprehensive school. The findings are especially relevant at a time when the Government is urging schools to set higher targets for physical activity to help fight against obesity. The research also revealed that the effect was considerably more noticeable in males than females, with mal
More Muscle Development News Articles
 | Anatomy for Strength and Fitness Training by Mark Vella Learn how your muscles work before you work your muscles Perfect for beginning and advanced fitness practitioners alike, this is an in-depth look into the most magnificent machine ever created--the human body. Using detailed anatomical illustrations, Anatomy for Strength and Fitness Training provides you visual insight into what happens to this organic machine during exercise--muscles and... |
 | Women's Guide to Strength and Anatomy Training by Mark Vella See How Your Muscles Work Before You Work Your Muscles! Anatomy for Strength and Fitness Training for Women provides magnificent visual insight into what happens to your muscles when you exercise. You'll be able to isolate specific muscle groups and design the most targeted program possible. Anatomy for Strength and Fitness Training for Women gives you: 100+ muscle-by-muscle... |
 | KineBody: Functional Strength Development for Men and Women by Edgardo Aponte WANT TO WORK OUT ANYWHERE, ANYTIME, WITH NO EQUIPMENT? NOW YOU CAN WITH KINEBODY! Are you turned off by going to a noisy gym? Hate working out in large groups? Do you want results without the expense? KineBody is the answer! In this concise, easy-to-follow book, Ed Aponte's revolutionary fitness program KineBody (pronounced kin-ay-body) concentrates on functional strength... |
 | Finding Keepers: The Monster Guide to Hiring and Holding the World's Best Employees by Steve Pogorzelski, Jesse Harriott Keepers. They are your best employees. They have the best ideas, execute business plans flawlessly, create a strong culture, and provide the highest value to your company. Keepers are by definition a rare breed-difficult to find and even harder to hold on to. Here, for the first time, Monster-the global leader in talent acquisition-reveals its proven program for recruiting and retaining high... |
 | Massive muscles in 10 weeks by Ellington Darden |
 | Skeletal Muscle Plasticity in Health and Disease: From Genes to Whole Muscle (Advances in Muscle Research) The ability of striated muscle tissue to adapt to changes in activity or in working conditions is extremely high. In some ways it is comparable to the ability of the brain to learn. The interest in muscle adaptation is increasing in relation to the idea that physical fitness helps in the prevention of disease, may counteract the loss of physical performance and generally improves wellbeing.... |
 | Structure and Development of Meat Animals and Poultry by H. J. Swatland An updated (and re-titled) edition of a major text, Structure and Development of Meat Animals and Poultry serves the information needs of meat science and animal production professionals and meat industry personnel. The book is well illustrated with more than 250 line drawings and photographs. Additionally, it is well organized for study and reference. Throughout the presentation, the basics of... |
 | Human Osteology: Comprising A Description Of The Bones With Delineations Of The Attachments Of The Muscles, The General And Microscopic Structure Of Bone And Its Development (1885) by Luther Holden |
 | Muscle Development and Growth (A Volume in the Fish Physiology Series) (Fish Physiology) With the advent of zebrafish as a model system, the development and growth of muscle in fish has become an ever more important process. This volume, in the continuing Fish Physiology series, focuses attention on muscle from the genetics of muscle development to application of muscle growth patterns to aquacultural... |
 | Health Series: Strength Training for Muscle Development (Health) by Mark Hatfield It's like having a personal trainer who's there all the time: here are precise muscle- and strength-building exercises that will work beautifully for both men and women, and inspire anyone trying to increase endurance and improve mobility and posture. From push-ups to squats, from flies with free weights to crunches, these are simply the best routines to get quick results. And there's information... |
| © 2008 BrightSurf.com |