Researchers have, for the first time, successfully converted adult human skin cells into neurons of the type that regulate appetite, providing a patient-specific model for studying the neurophysiology of weight control and testing new therapies for obesity. To make the neurons, human skin cells were first genetically reprogrammed to become induced pluripotent stem (iPS) cells.
Scientists have discovered that the human brain can produce new neurons, but exactly how those...
After using optical tweezers to squeeze a tiny bead attached to the outside of a human stem cell...
A stem cell capable of regenerating both bone and cartilage has been identified in bone marrow of mice. The cells, called osteochondroreticular (OCR) stem cells, were discovered by tracking a protein expressed by the cells. Using this marker, the researchers found that OCR cells self-renew and generate key bone and cartilage cells, including osteoblasts and chondrocytes.
Electroporation is a powerful technique in molecular biology. By using an electrical pulse to create a temporary nanopore in a cell membrane, researchers can deliver chemicals, drugs and DNA directly into a single cell. But existing electroporation methods require high electric field strengths and for cells to be suspended in solution, which disrupts cellular pathways and creates a harsh environment for sensitive primary cells.
The immune system is a complex network of many different cells working together to defend against invaders. Successfully fighting off an infection depends on the interactions between these cells. A new device developed by Massachusetts Institute of Technology engineers offers a much more detailed picture of that cellular communication.
Univ. of California, Irvine scientists studying the role of circadian rhythms in skin stem cells found that this clock plays a key role in coordinating daily metabolic cycles and cell division. Their research, which appears in Cell Reports, shows, for the first time, how the body’s intrinsic day-night cycles protect and nurture stem cell differentiation.
In a recent study, Univ. of California, Los Angeles scientists have shown that two genes not previously known to be involved with the immune system play a crucial role in how progenitor stem cells are activated to fight infection. This discovery lays the groundwork for a better understanding of the role progenitor cells can play in immune system response and could lead to the development of more effective therapies for diseases.
New research from Rice Univ. and the Univ. of Texas MD Anderson Cancer Center shows how ovarian tumors co-opt a specific type of adult stem cell from abdominal tissues to fuel their growth. The research, published online in Cancer Research, suggests a new way to target aggressive ovarian cancers by disrupting the metabolic processes that allow them to thrive.
After more than six years of intensive effort, and repeated failures that made the quest at times seem futile, Harvard Stem Cell Institute researchers at Boston Children’s Hospital and Harvard’s Dept. of Stem Cell and Regenerative Biology have successfully converted mouse and human skin cells into pain-sensing neurons that respond to a number of stimuli that cause acute and inflammatory pain.
Harvard Stem Cell Institute (HSCI) researchers at Massachusetts General (MGH) and Boston Children’s hospitals (BCH) for the first time have used a relatively new gene-editing technique to create what could prove to be an effective technique for blocking HIV from invading and destroying patients’ immune systems.
In the first study of its kind, Rice Univ. researchers have mapped how information flows through the genetic circuits that cause cancer cells to become metastatic. The research reveals a common pattern in the decision-making that allows cancer cells to both migrate and form new tumors.
When most animals begin life, cells immediately begin accepting assignments to become a head, tail or a vital organ. However, mammalian cells become the protective placenta or to commit to forming the baby. It’s during this critical first step that research from Michigan State Univ. has revealed key discoveries. The results provide insights into where stem cells come from, and could advance research in regenerative medicine.
While megakaryocytes are best known for producing platelets that heal wounds, these "mega" cells found in bone marrow also play a critical role in regulating stem cells according to new research from the Stowers Institute for Medical Research. The study is the first to show that hematopoietic stem cells (the parent cells) can be directly controlled by their own progeny (megakaryocytes).
Within our fat lives a variety of cells with the potential to become bone, cartilage or more fat if properly prompted. This makes adipose tissue, in theory, a readily available reservoir for regenerative therapies such as bone healing if doctors can get enough of those cells and compel them to produce bone. In a new study, scientists demonstrate a new method for extracting a wide variety of potential bone-producing cells from human fat.
A 7-year-project to develop a barcoding and tracking system for tissue stem cells has revealed previously unrecognized features of normal blood production: New data from Harvard Stem Cell Institute scientists at Boston Children's Hospital suggests, surprisingly, that the billions of blood cells that we produce each day are made not by blood stem cells, but rather their less pluripotent descendants, called progenitor cells.
The liver provides critical functions, such as ridding the body of toxins, but its failure can be deadly, and there are few options for fixing it. A promising alternative in development is transplanting liver cells made using adult stem cells, but the only source identified until now has been bone marrow. Recently, scientists identified another, more convenient, source of adult stem cells that could be used for this purpose:tonsils.
Biochemists in California have developed a program that predicts the placement of chemical marks that control the activity of genes based on sequences of DNA. By comparing sequences with and without epigenomic modification, the researchers identified DNA patterns associated with the changes. They call this novel analysis pipeline Epigram and have made both the program and the DNA motifs they identified openly available to other scientists.
It’s one of the highest-profile cases of scientific fraud in memory: In 2005, South Korean researcher Woo-Suk Hwang and colleagues made international news by claiming that they had produced embryonic stem cells from a cloned human embryo using nuclear transfer. But within a year, the work had been debunked, soon followed by findings of fraud. South Korea put a moratorium on stem cell research funding.
The Japanese laboratory that retracted a paper reporting a potentially major breakthrough in stem cell research said Wednesday its researchers have not managed to replicate the results. Scientists at the government-affiliated RIKEN Center for Developmental Biology said they are still trying to match results reported in two papers published by Nature in January and then retracted in July.
Cytori Therapeutics said Tuesday it has halted trials of its experimental stem cell therapy for heart failure after three patients developed blood flow problems. The San Diego-based company said it placed the hold on two studies after the patients developed problems with blood flow to the brain. Two of the patients' symptoms resolved in a short period of time and a third was still recovering, the company said in a statement.
A new stem cell discovery might one day lead to a more streamlined process for obtaining stem cells, which in turn could be used in the development of replacement tissue for failing body parts, according to Univ. of California, San Francisco scientists who reported the findings in Cell.
In two papers published in January in the journal Nature, Japanese and American researchers said that they'd been able to transform ordinary mouse cells into versatile stem cells by exposing them to a mildly acidic environment. The scientists withdrew that claim Wednesday, admitting to "extensive" errors that meant they were “unable to say without a doubt" that the method works.
New research led by the Salk Institute shows, for the first time, that stem cells created using two different methods are far from identical. Their work reveals that stem cells created by moving genetic material from a skin cell into an empty egg cell, instead of activating genes to revert adult cells to their embryonic state, more closely resemble human embryonic stem cells, which are considered the gold standard in the field.
Mesenchymal stem cells have become attractive tools for bioengineers, but some scientists haven’t given up on their regenerative potential. A research team at Harvard Univ. recently found that transplanting mesenchymal stem cells along with blood vessel-forming cells naturally found in circulation improves results. This co-transplantation keeps the mesenchymal stem cells alive longer in mice after engraftment, up to weeks from just hours.
Researchers have developed new methods to trace the life history of individual cells back to their origins in the fertilized egg. By looking at the copy of the human genome present in healthy cells, and by looking at the numbers and types of mutations in a cell's DNA, biologists in the U.K. have been able to build a picture of each cell's development from the early embryo on its journey to become part of an adult organ.
New research suggests that scientists have only scratched the surface of understanding the nature, physiology and location of stem cells. Specifically, the report suggests that embryonic and induced pluripotent stem cells may not be the only source from which all three germ layers in the human body (nerves, liver or heart and blood vessels) can develop.
Scientists working to make gene therapy a reality have solved a major hurdle: how to bypass a blood stem cell’s natural defenses and efficiently insert disease-fighting genes into the cell’s genome. In a new study, a team of researchers report that the drug rapamycin, which is commonly used to slow cancer growth, enables delivery of a therapeutic dose of genes to blood stem cells while preserving stem cell function.
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