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Archive - Nov 2, 2019


Researchers Engineer Insulin-Producing Cells Activated by Light for Diabetes

Tufts University researchers have transplanted engineered pancreatic beta cells into diabetic mice, then caused the cells to produce more than two to three times the typical level of insulin by exposing them to light. The light-switchable cells are designed to compensate for the lower insulin production or reduced insulin response found in diabetic individuals. The study, published online on Septembr 13, 2019 in ACS Synthetic Biology, shows that glucose levels can be controlled in a mouse model of diabetes without pharmacological intervention. The article is titled “Amelioration of Diabetes in a Murine Model Upon Transplantation of Pancreatic Β-Cells with Optogenetic Control of Cyclic AMP.” Insulin is a hormone that plays a central role in precisely controlling levels of circulating glucose - the essential fuel used by cells -. Diabetes affects more than 30 million Americans according to the Centers for Disease Control and Prevention (CDC). In type II diabetes - the most common form of the disease - the cells of the body become inefficient at responding to insulin and as a consequence, glucose in circulation can become dangerously high (hyperglycemia) while the pancreas cannot produce enough insulin to compensate. In type I diabetes, the beta cells, which are the only cells in the body that produce insulin, are destroyed by the immune system resulting in complete lack of the hormone. Current treatments include the administration of drugs that enhance the production of insulin by pancreatic beta cells, or direct injection of insulin to supplement the naturally produced supply. In both cases, regulation of blood glucose becomes a manual process, with drug or insulin intervention conducted after periodic readings of glucose levels, often leading to spikes and valleys that can have harmful long-term effects.

Lymphatic System Found to Play Key Role in Hair Regeneration

Given the amount of wear and tear it's subjected to on a daily basis, the skin has a phenomenal ability to replenish itself. Spread throughout it are small reservoirs of stem cells, nested within supportive microenvironments called niches, which keep a tight rein on this repair process. Too much tissue might cause problems like cancer, while too little might accelerate aging. Until now, scientists were uncertain whether the stem cells themselves could instruct other stem cells to form new skin by reshaping their niche. But new research in Science, led by Elaine Fuchs, PhD, the Rebecca C. Lancefield Professor at the Rockefeller University, indicates that stem cells can indeed influence tissue regeneration. The open-access article, published online on October 31, 2019, is titled “Stem Cell–Driven Lymphatic Remodeling Coordinates Tissue Regeneration.” The study identifies a molecular coordination tool used by stem cells to signal across niches. The researchers also discovered a new component of the niche: a specialized type of vessel called lymphatic capillaries, which transport immune cells and drain excess fluids and toxins from tissues. These capillaries form an intimate network around the stem cell niche within each hair follicle, the study showed, thereby interconnecting all its niches. "By turning the skin completely transparent," says postdoctoral fellow Shiri Gur-Cohen, PhD, "we were able to reveal the complex architecture of this network of tubes." Hair-follicle stem cells control the behavior of lymphatic capillaries by secreting molecules that act as an on-off switch for drainage, the scientists found, enabling them to control the composition of fluids and cells in the surrounding locale and ultimately synchronize regeneration across the tissue.