Sensory cells in the vagus nerve can detect and locate food in the esophagus. Their signals help transport the food onward to the stomach. Signal failure leads to swallowing disorders, say a team led by Carmen Birchmeier at the Max Delbrück Center.
Sensory cells in the vagus nerve can detect and locate food in the esophagus. Their signals help transport the food onward to the stomach. Signal failure leads to swallowing disorders, say a team led by Carmen Birchmeier at the Max Delbrück Center. They have published their findings in “Neuron.”
Proteins play crucial role in muscle growth
When a muscle grows, because its owner is still growing too or has started exercising regularly, some of the stem cells in this muscle develop into new muscle cells.
The same thing happens when an injured muscle starts to heal. At the same time, however, the muscle stem cells must produce further stem cells - i.e., renew themselves - as their supply would otherwise be depleted very quickly. This requires that the cells involved in muscle growth communicate with each other.
Muscle growth is regulated by the Notch signaling pathway
Two years ago, a team of researchers led by Professor Carmen Birchmeier, head of the Developmental Biology/Signal Transduction Lab at the Berlin-based Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), showed that the development of stem cells into muscle cells is regulated with the help of two proteins, Hes1 and MyoD, which are produced in the progenitor cells in an oscillatory man
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IMAGE: Immunofluorescence analysis of a group of proliferating stem cells associated with a muscle fiber (grey). The stem cells produce Dll1 (red) and MyoD (green). Two of the cells produces MyoG. view more
Credit: Birchmeier Lab, MDC
When a muscle grows, because its owner is still growing too or has started exercising regularly, some of the stem cells in this muscle develop into new muscle cells. The same thing happens when an injured muscle starts to heal. At the same time, however, the muscle stem cells must produce further stem cells - i.e., renew themselves - as their supply would otherwise be depleted very quickly. This requires that the cells involved in muscle growth communicate with each other.
Study unlocks some muscle cell secrets
A muscle fiber consists of just one cell, but many nuclei. A team at the MDC led by Professor Carmen Birchmeier has now shown just how varied these nuclei are. The study, which has been published in
Nature Communications, can help us better understand muscle diseases such as Duchenne muscular dystrophy.
Usually, each cell has exactly one nucleus. But the cells of our skeletal muscles are different: These long, fibrous cells have a comparatively large cytoplasm that contains hundreds of nuclei. But up to now, we have known very little about the extent to which the nuclei of a single muscle fiber differ from each other in terms of their gene activity, and what effect this has on the function of the muscle.