Credit: Martha Sexton/public domain A type of mouse widely used to assess how the human immune system responds to transplanted stem cells does not reflect what is likely to occur in patients, according to a study by researchers at the Stanford University School of Medicine. The researchers urge further optimization of this animal model before making decisions about whether and when to begin wide-scale stem cell transplants in humans. Known as "humanized" mice, the animals have been engineered to have a human, rather than a murine, immune system. Researchers have relied upon the animals for decades to study, among other things, the immune response to the transplantation of pancreatic islet cells for diabetes and skin grafts for burn victims. However, the Stanford researchers found that, unlike what would occur in a human patient, the humanized mice are unable to robustly reject the transplantation of genetically mismatched human stem cells. As a result, they can't be used to study the immunosuppressive drugs that patients will likely require after transplant. The researchers conclude that the humanized mouse model is not suitable for studying the human immune response to transplanted stem cells or cells derived from them. "In an ideal situation, these humanized … Continue reading →

Two new studies look at using stem cells from lungs to combat fibrosis and other lung-related diseases. Stem cell treatments for lung diseases may have taken a big step forward according to a pair of studies published earlier this month. In one animal study, researchers did transbronchial biopsies, sending miniscule tweezers down the throats of rats in order to obtain lung cells. The researchers were able to culture tens of millions of cells and inject them into rats that had a condition similar to idiopathic pulmonary fibrosis. Rats that received the injected cells showed less lung inflammation and overall healthier lung cells than those that didnt receive the cells. Both studies, published in the journals Respiratory Research and Stem Cells Translational Medicine, built upon research into stem cell therapies for heart diseases, and less successful work on lung diseases like emphysema. Both offer new hope for fibrosis patients, whose current treatment options are medications to reduce symptoms, or a lung transplant. The new research raises the possibility of reversing the impacts of fibrosis and similar diseases that cause lung inflammation, which gradually damages lung tissue and makes internal organs less able to transfer oxygen to the blood. Its also the … Continue reading →

Not much is known about stem cell metabolism, but a new study from the Childrens Medical Center Research Institute at UT Southwestern (CRI) has found that stem cells take up unusually high levels of vitamin C, which then regulates their function and suppresses the development of leukemia. We have known for a while that people with lower levels of ascorbate (vitamin C) are at increased cancer risk, but we havent fully understood why. Our research provides part of the explanation, at least for the blood-forming system, said Dr. Sean Morrison, the Director of CRI. The metabolism of stem cells has historically been difficult to study because a large number of cells are required for metabolic analysis, while stem cells in each tissue of the body are rare. Techniques developed during the study, which was published in Nature, have allowed researchers to routinely measure metabolite levels in rare cell populations such as stem cells. The techniques led researchers to discover that every type of blood-forming cell in the bone marrow had distinct metabolic signatures taking up and using nutrients in their own individual way. One of the main metabolic features of stem cells is that they soak up unusually high levels … Continue reading →

Dr. Michalis Agathocleous (left) and Dr. Sean Morrison. Credit: UT Southwestern Not much is known about stem cell metabolism, but a new study from the Children's Medical Center Research Institute at UT Southwestern (CRI) has found that stem cells take up unusually high levels of vitamin C, which then regulates their function and suppresses the development of leukemia. "We have known for a while that people with lower levels of ascorbate (vitamin C) are at increased cancer risk, but we haven't fully understood why. Our research provides part of the explanation, at least for the blood-forming system," said Dr. Sean Morrison, the Director of CRI. The metabolism of stem cells has historically been difficult to study because a large number of cells are required for metabolic analysis, while stem cells in each tissue of the body are rare. Techniques developed during the study, which was published in Nature, have allowed researchers to routinely measure metabolite levels in rare cell populations such as stem cells. The techniques led researchers to discover that every type of blood-forming cell in the bone marrow had distinct metabolic signatures - taking up and using nutrients in their own individual way. One of the main metabolic … Continue reading →

CALIFORNIA HAS never been reluctant to take the lead on critical issues facing the nation. When federal funding was cut off for embryonic stem cell research, it created its own state program. It adopted standards for vehicle emissions and fuel efficiency that have been emulated by other states, and it has doubled down on a commitment to climate change policy in the face of disinterest, if not outright hostility, from the Trump administration. But perhaps nothing is more welcome than Californias decision to advance the science of gun-violence prevention with the establishment of the countrys first publicly funded research center. The Firearm Violence Research Center, launched last month at the University of California at Davis with a $5 million appropriation from the state, aims to find effective ways to prevent firearm violence through scientific investigation and understanding. Located at the universitys Sacramento campus, the research institute will augment the work of Garen Wintemute, an emergency-room physician and nationally recognized expert on the epidemiology of firearm violence who serves as its director. Californias decision to be at the forefront of research on gun violence as a public-health issue stands in contrast to the dismal abdication of the federal government. Legislation passed … Continue reading →