As many of us know from hard experience, tearing a muscle while exercising can be a real pain. The good news is that injured muscle will usually heal quickly for many of us with the help of satellite cells. Never heard of them? They are the adult stem cells in our skeletal muscles long recognized for their capacity to make new muscle fibers called myotubes.
This striking image shows what happens when satellite cells from mice are cultured in a lab dish. With small adjustments to the lab dish’s growth media, those cells fuse to form myotubes. Here, you see the striated myotubes (red) with multiple cell nuclei (blue) characteristic of mature muscle fibers. The researchers also used a virus to genetically engineer some of the muscle to express a fluorescent protein (green).
Whether by snail mail, email, or social media, it’s the time of year for catching up with family and friends. As NIH Director, I’m also fortunate to hear from some of the amazing people who’ve been helped by NIH research. Among the greetings to arrive in my inbox this holiday season is this incredible video from a 15-year-old named Aaron, who is fortunate enough to count two states—Alabama and Colorado—as his home.
As a young boy, Aaron was naturally athletic, speeding around the baseball diamond and competing on the ski slopes in freestyle mogul. But around the age of 10, Aaron noticed something strange. He couldn’t move as fast as usual. Aaron pushed himself to get back up to speed, but his muscles grew progressively weaker.
Tags: anti-HMGCR myopathy, antibodies, autoimmunity, childhood diseases, clinical research, clinical trials, immunology, intravenous immunoglobulins, IVIG, muscle, muscle diseases, muscular dystrophy, myopathy, statins
Twice a week, I do an hour of weight training to maintain muscle strength and tone. Millions of Americans do the same, and there’s always a lot of attention paid to those upper arm muscles—the biceps and triceps. Less appreciated is another arm muscle that pumps right along during workouts: the brachialis. This muscle—located under the biceps—helps your elbow flex when you are doing all kinds of things, whether curling a 50-pound barbell or just grabbing a bag of groceries or your luggage out of the car.
Now, scientific studies of the triceps and brachialis are providing important clues about how the body’s 40 different types of limb muscles assume their distinct identities during development . In these images from the NIH-supported lab of Gabrielle Kardon at the University of Utah, Salt Lake City, you see the developing forelimb of a healthy mouse strain (top) compared to that of a mutant mouse strain with a stiff, abnormal gait (bottom).
Tags: brachialis, connective tissue, development, FluoRender, forelimb muscles, genetics, genomics, lateral triceps, limb muscles, limbs, mouse, mouse genetics, muscle, musculoskeletal disorder, rare disease, Tbx3, transcription factor, triceps, ulnar-mammary syndrome, UMS, University of Utah’s 2016 Research as Art
The image above shows a small section of the trachea, or windpipe, of a developing mouse. Although it’s only about the diameter of a pinhead at this stage of development, the mouse trachea has a lot in common structurally with the much wider and longer human trachea. Both develop from a precisely engineered balance between the flexibility of smooth muscle and the supportive strength and durability of cartilage.
Here you can catch a glimpse of this balance. C-rings of cartilage (red) wrap around the back of the trachea, providing the support needed to keep its tube open during breathing. Attached to the ends of the rings are dark shadowy bands of smooth muscles, which are connected to a web of nerves (green). The tension supplied by the muscle cells is essential for proper development of those neatly organized cartilage rings.
Tags: airways, cartilage, cartilage rings, congenital tracheomalacia, development, FASEB Bioart 2016, mineralized tissue, muscle, pulmonary disease, rare disease, respiratory system, smooth muscle, trachea, trachea development, upper airway, windpipe