Bone marrow is a sponge tissue in most of human bones. It produces red blood cells and immune cells to help fight infections and heal wounds. According to a new study published online in the August 27 issue of Nature Neuroscience, the researchers found a tiny channel in the skull bone marrow to the inner wall of the brain that may respond to immune cells' damage to stroke and other brain diseases. Provides a quick and direct path. "We have always believed that the immune cells of the extremities need to pass through the blood into the damaged brain tissue, and the study suggests that immune cells may not be so, but copied quickly to the inflammatory area." NIH Institute of Neurological Disorders and Stroke (NINDS) Program Director Dr. Francesca Bosetti said, “Inflammation plays an important role in many brain diseases. This new discovery channel may be important in many cases, which opens the way for discovering new research approaches. †Dr. Matthias Nahrendorf, a professor at Harvard Medical School and Massachusetts General Hospital, and colleagues used advanced tools and mouse cell-specific dyes to distinguish whether immune cells arriving at damaged brain tissue are from the skull bone or the tibia, in this study. The researchers selected neutrophils as a subject of observation. Neutrophils are a special type of immune cell that first reaches the site of injury. The results show that during stroke in mice, the skull is more likely to provide neutrophils to the damaged tissue than the tibia, and at the heart far from both, the skull and the tibia provide a similar amount to the heart after the onset of the disease. The neutrophils, Dr. Nahrendorf's team also observed that after 6 hours of stroke, the neutrophils in the bone marrow of the skull were less than the neutrophils in the bone marrow of the tibia, indicating that the bone marrow of the skull was released to the injured site. More cells. Newly discovered channels in the skull provide a shortcut for immune cells to enter damaged tissue Credit: Nahrendorf Lab These findings suggest that systemic bone marrow does not uniformly provide immune cells to injured or infected tissues, and studies suggest that there may be some form of "communication" between the damaged brain and the skull bone marrow, resulting in direct access to adjacent white blood cells. reaction. The team found that differences in bone marrow activity during inflammation may be caused by stromal cell-derived factor-1 (SDF-1), a molecule that preserves immune cells in the bone marrow. When SDF-1 levels are lowered, neutrophils are released from the bone marrow. The researchers observed that after 6 hours of stroke, the level of SDF-1 decreased, but only in the skull bone marrow rather than the tibia. Therefore, a decrease in SDF-1 levels may be a response and alert to local tissue damage and activate only the bone marrow closest to the site of inflammation. Next, the team wanted to know how neutrophils reached the injured tissue. “We started examining the skull very carefully, looking at it from all angles, trying to figure out how neutrophils enter the brain,†Dr. Nahrendorf said. “Unexpectedly, we found some tiny channels that are directly Connected to the outer layer of the bone marrow and brain." With advanced imaging techniques, the researchers observed the movement of neutrophils in the channel. The blood usually flows from the channel inside the skull to the bone marrow, but after the stroke, the neutrophils move in the opposite direction and enter the damaged tissue. . Dr. Nahrendorf's team examined the entire skull and tibia, and detailed imaging of human skull samples obtained by surgery revealed the presence of these channels. Compared to those found in mice, the diameter of the passage in the human skull is five times larger, and in the skulls of humans and mice, channels are found in both the inner and outer layers of the bone. Next, the researchers plan to identify other types of cells that pass through these channels and the role these structures play in human health and disease. Pickled Beefsteak,Frozen Pickled Beefsteak,Seasoned Pickled Beef Cubes,Fillet Steak ZHOUSHAN JING YUAN FOOD CO.,LTD , https://www.genho-food.com
