Anderson, United States
Anderson, United States

Time filter

Source Type

News Article | April 25, 2017
Site: www.sciencedaily.com

Antidepressants treat symptoms of depression by increasing levels of brain signaling molecules (neurotransmitters) such as serotonin, as with the most widely used type of antidepressant, selective serotonin reuptake inhibitors (SSRIs). However, many of the 350 million people worldwide thought to be affected with depression do not respond to SSRI treatment. Now, researchers in the Department of Neuroscience and Cell Biology at Osaka University have found that an activator of the serotonin type 3 receptor (5HT3R) produces antidepressant effects in mice and increases nerve cell growth in the part of the brain responsible for memory and spatial navigation (the hippocampus). They also showed that it functions using a different mechanism than the commonly used SSRI fluoxetine, and therefore may be suitable for patients with depression who do not respond favorably to current medication. The team of researchers used mice lacking part of 5HT3R to explore the function of the 5HT3R activator. The activator had antidepressant effects and initiated nerve cell growth in the hippocampus in control mice but not in those lacking part of the receptor. In contrast, fluoxetine showed similar antidepressant actions and nerve cell growth in both control and knockout mice because it requires the type 1A rather than 5HT3R for its actions. To explore the 5HT3R activator mode of action, hippocampal nerve cells expressing the receptor were chemically stained to investigate protein expression. The same cells were shown to express both the receptor and the growth factor IGF1. "Treatment of control mice with the receptor activator led to increases in IGF1 secretion," study coauthor Shoichi Shimada says. "However, the activator had no effect in mice lacking part of the receptor." In addition, protein signaling involving IGF1 in the hippocampus was found to be necessary for nerve cell growth that was dependent on 5HT3R. Fluoxetine must be given to patients for long periods to have any antidepressant effect, but just 3 days of 5HT3R activator treatment produced notable responses in mice. "IGF1 combined with the activator produced characteristic changes in nerve cell growth that were not seen following fluoxetine administration," corresponding author Makoto Kondo says. "This may explain why the response times are so different." Another difference is that the type 1A and 5HT3R are expressed in different cell types of the hippocampus which adds support to their use of distinct mechanisms of antidepressant action.


Researchers at Baylor College of Medicine have uncovered a new mechanism showing how microbes can alter the physiology of the organisms in which they live. In a paper published in Nature Cell Biology, the researchers reveal how microbes living inside the laboratory worm C. elegans respond to environmental changes and generate signals to the worm that alter the way it stores lipids.


News Article | April 11, 2017
Site: www.medicalnewstoday.com

St. Jude Children's Research Hospital study examines origin of blood stem cells during development and offers clues for making "donor blood" in the laboratory for therapeutic use. Like private investigators on a stake out, St. Jude Children's Research Hospital scientists used patience and video surveillance-like tools to identify cells that trigger blood cell development. The findings offer clues for making blood-forming stem cells in the laboratory that may ultimately help improve access to bone marrow transplantation. "The research will likely open new avenues of investigation in stem cell biology and blood development and provide insight to aid efforts to make transplantable hematopoietic stem cells in the lab," said corresponding author Wilson Clements, Ph.D., an assistant member of the St. Jude Department of Hematology. The research appears in the journal Nature Cell Biology. Blood-forming stem cells are capable of making any type of blood cell in the body. They are also used in transplant therapies for cancers like leukemia or other blood diseases like sickle cell. They are starting to be used to deliver gene therapy. However, a shortage of suitable donors limits access to treatment, and efforts to produce blood from pluripotent stem cells in the laboratory have been unsuccessful. Pluripotent stem cells are the master cells capable of making any cell in the body. All blood-forming stem cells normally arise before birth from certain endothelial cells found in the interior blood vessel lining of the developing aorta. This process - including how endothelial cells are set on the path to becoming blood stem cells - is not completely understood. Clements and first author Erich Damm, Ph.D., a St. Jude postdoctoral fellow, have identified trunk neural crest cells as key orchestrators of the conversion of endothelial cells to blood stem cells. Trunk neural crest cells are made in the developing spinal cord and migrate throughout the embryo. They eventually give rise to a variety of adult cells, including neurons and glial cells in the sympathetic and parasympathetic nervous system, which control feeding, fighting, fleeing and procreating. Using time-lapse video, the researchers tracked the migration of neural crest cells in the transparent embryos of zebrafish. Zebrafish and humans share nearly identical blood systems, as well as the programming that makes them during development. After about 20 hours, the neural crest cells had reached the developing aorta. After hour 24, the migrating cells had cozied up to the endothelial cells in the aorta, which then turned on genes, such as runx1, indicating their conversion to blood stem cells. The investigators used a variety of methods to show that disrupting the normal migration of neural crest cells or otherwise blocking their contact with the aorta endothelial cells prevented the "birth" of blood stem cells. Meanwhile, other aspects of zebrafish development were unaffected. "Researchers have speculated that the endothelial cells that give rise to blood-forming stem cells are surrounded by a support 'niche' of other cells whose identity and origins were unknown," Damm said. "Our results support the existence of a niche, and identify trunk neural crest cells as an occupant." Adult bone marrow includes niches that support normal function and notably feature cells derived from trunk neural crest cells. The findings also suggest that trunk neural crest cells use a signal or signals to launch blood stem cell production during development. The researchers have eliminated adrenaline and noradrenaline as the signaling molecules, but work continues to identify the signaling proteins or small molecules involved. The research was supported in part by a grant (R00HL097) from the National Heart, Lung and Blood Institute of the National Institutes of Health; the March of Dimes; and ALSAC, the fundraising arm of St. Jude.


News Article | May 1, 2017
Site: www.biosciencetechnology.com

A team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue by printing stem cells using a 3D-bioprinter. The fact that the stem cells survived being printed in this manner is a success in itself. In addition, the research team was able to influence the cells to multiply and differentiate to form chondrocytes (cartilage cells) in the printed structure. The findings have been published in Nature's Scientific Reports. The research project is being conducted in collaboration with a team of researchers at the Chalmers University of Technology who are experts in the 3D printing of biological materials. Orthopedic researchers from Kungsbacka are also involved in the research collaboration. The team used cartilage cells harvested from patients who underwent knee surgery, and these cells were then manipulated in a laboratory, causing them to rejuvenate and revert into "pluripotent" stem cells, i.e. stem cells that have the potential to develop into many different types of cells. The stem cells were then expanded and encapsulated in a composition of nanofibrillated cellulose and printed into a structure using a 3D bioprinter. Following printing, the stem cells were treated with growth factors that caused them to differentiate correctly, so that they formed cartilage tissue. Tricked into thinking that they aren't alone The publication in Scientific Reports is the result of three years of hard work. "In nature, the differentiation of stem cells into cartilage is a simple process, but it's much more complicated to accomplish in a test tube. We're the first to succeed with it, and we did so without any animal testing whatsoever," said Stina Simonsson, Associate Professor of Cell Biology, who lead the research team's efforts. Most of the team's efforts had to do with finding a procedure so that the cells survive printing, multiply and a protocol that works that causes the cells to differentiate to form cartilage. "We investigated various methods and combined different growth factors. Each individual stem cell is encased in nanocellulose, which allows it to survive the process of being printed into a 3D structure. We also harvested mediums from other cells that contain the signals that stem cells use to communicate with each other so called conditioned medium. In layman's terms, our theory is that we managed to trick the cells into thinking that they aren't alone," clarified Stina Simonsson. Therefore the cells multiplied before we differentiated them. A key insight gained from the team's study is that it is necessary to use large amounts of live stem cells to form tissue in this manner. The cartilage formed by the stem cells in the 3D bioprinted structure is extremely similar to human cartilage. Experienced surgeons who examined the artificial cartilage saw no difference when they compared the bioprinted tissue to real cartilage, and have stated that the material has properties similar to their patients' natural cartilage. Just like normal cartilage, the lab-grown material contains Type II collagen , and under the microscope the cells appear to be perfectly formed, with structures similar to those observed in samples of human-harvested cartilage. Potential for use in osteoarthritis therapies The study represents a giant step forward in the ability to generate new, endogenous cartilage tissue. In the not too distant future, it should be possible to use 3D bioprinting to generate cartilage based on a patient's own, "backed-up" stem cells. This bioprinted tissue can be used to repair cartilage damage, or to treat osteoarthritis, in which joint cartilage degenerates and breaks down. The condition is very common -- one in four Swedes over the age of 45 suffer from some degree of osteoarthritis. In theory, this research has created the opportunity to generate large amounts of cartilage, but one major issue must be resolved before the findings can be used in practice to benefit patients. "The structure of the cellulose we used might not be optimal for use in the human body. Before we begin to explore the possibility of incorporating the use of 3D bioprinted cartilage into the surgical treatment of patients, we need to find another material that can be broken down and absorbed by the body so that only the endogenous cartilage remains, the most important thing for use in a clinical setting is safety" explained Stina Simonsson.


News Article | April 28, 2017
Site: www.eurekalert.org

A team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue by printing stem cells using a 3D-bioprinter. The fact that the stem cells survived being printed in this manner is a success in itself. In addition, the research team was able to influence the cells to multiply and differentiate to form chondrocytes (cartilage cells) in the printed structure. The findings have been published in Nature's Scientific Reports magazine. The research project is being conducted in collaboration with a team of researchers at the Chalmers University of Technology who are experts in the 3D printing of biological materials. Orthopedic researchers from Kungsbacka are also involved in the research collaboration. The team used cartilage cells harvested from patients who underwent knee surgery, and these cells were then manipulated in a laboratory, causing them to rejuvenate and revert into "pluripotent" stem cells, i.e. stem cells that have the potential to develop into many different types of cells. The stem cells were then expanded and encapsulated in a composition of nanofibrillated cellulose and printed into a structure using a 3D bioprinter. Following printing, the stem cells were treated with growth factors that caused them to differentiate correctly, so that they formed cartilage tissue. Tricked into thinking that they aren't alone The publication in Scientific Reports is the result of three years of hard work. "In nature, the differentiation of stem cells into cartilage is a simple process, but it's much more complicated to accomplish in a test tube. We're the first to succeed with it, and we did so without any animal testing whatsoever," says Stina Simonsson, Associate Professor of Cell Biology, who lead the research team's efforts. Most of the team's efforts had to do with finding a procedure so that the cells survive printing, multiply and a protocol that works that causes the cells to differentiate to form cartilage. "We investigated various methods and combined different growth factors. Each individual stem cell is encased in nanocellulose, which allows it to survive the process of being printed into a 3D structure. We also harvested mediums from other cells that contain the signals that stem cells use to communicate with each other so called conditioned medium. In layman's terms, our theory is that we managed to trick the cells into thinking that they aren't alone," clarifies Stina Simonsson. Therefore the cells multiplied before we differentiated them. A key insight gained from the team's study is that it is necessary to use large amounts of live stem cells to form tissue in this manner. The cartilage formed by the stem cells in the 3D bioprinted structure is extremely similar to human cartilage. Experienced surgeons who examined the artificial cartilage saw no difference when they compared the bioprinted tissue to real cartilage, and have stated that the material has properties similar to their patients' natural cartilage. Just like normal cartilage, the lab-grown material contains Type II collagen , and under the microscope the cells appear to be perfectly formed, with structures similar to those observed in samples of human-harvested cartilage. Potential for use in osteoarthritis therapies The study represents a giant step forward in the ability to generate new, endogenous cartilage tissue. In the not too distant future, it should be possible to use 3D bioprinting to generate cartilage based on a patient's own, "backed-up" stem cells. This bioprinted tissue can be used to repair cartilage damage, or to treat osteoarthritis, in which joint cartilage degenerates and breaks down. The condition is very common -- one in four Swedes over the age of 45 suffer from some degree of osteoarthritis. In theory, this research has created the opportunity to generate large amounts of cartilage, but one major issue must be resolved before the findings can be used in practice to benefit patients. "The structure of the cellulose we used might not be optimal for use in the human body. Before we begin to explore the possibility of incorporating the use of 3D bioprinted cartilage into the surgical treatment of patients, we need to find another material that can be broken down and absorbed by the body so that only the endogenous cartilage remains, the most important thing for use in a clinical setting is safety" explains Stina Simonsson.


News Article | April 28, 2017
Site: www.chromatographytechniques.com

A team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue by printing stem cells using a 3D-bioprinter. The fact that the stem cells survived being printed in this manner is a success in itself. In addition, the research team was able to influence the cells to multiply and differentiate to form chondrocytes (cartilage cells) in the printed structure. The findings have been published in Nature’s Scientific Reports magazine. The research project is being conducted in collaboration with a team of researchers at the Chalmers University of Technology who are experts in the 3D printing of biological materials. Orthopedic researchers from Kungsbacka are also involved in the research collaboration. The team used cartilage cells harvested from patients who underwent knee surgery, and these cells were then manipulated in a laboratory, causing them to rejuvenate and revert into “pluripotent” stem cells, i.e. stem cells that have the potential to develop into many different types of cells. The stem cells were then expanded and encapsulated in a composition of nanofibrillated cellulose and printed into a structure using a 3D bioprinter. Following printing, the stem cells were treated with growth factors that caused them to differentiate correctly, so that they formed cartilage tissue. The publication is the result of three years of hard work. “In nature, the differentiation of stem cells into cartilage is a simple process, but it’s much more complicated to accomplish in a test tube. We’re the first to succeed with it, and we did so without any animal testing whatsoever," says Stina Simonsson, Associate Professor of Cell Biology, who lead the research team’s efforts. Most of the team’s efforts had to do with finding a procedure so that the cells survive printing, multiply and a protocol that works that causes the cells to differentiate to form cartilage. "We investigated various methods and combined different growth factors. Each individual stem cell is encased in nanocellulose, which allows it to survive the process of being printed into a 3D structure. We also harvested mediums from other cells that contain the signals that stem cells use to communicate with each other so called conditioned medium. In layman’s terms, our theory is that we managed to trick the cells into thinking that they aren’t alone,” clarifies Simonsson. "Therefore, the cells multiplied before we differentiated them." A key insight gained from the team’s study is that it is necessary to use large amounts of live stem cells to form tissue in this manner. The cartilage formed by the stem cells in the 3D bioprinted structure is extremely similar to human cartilage. Experienced surgeons who examined the artificial cartilage saw no difference when they compared the bioprinted tissue to real cartilage, and have stated that the material has properties similar to their patients’ natural cartilage. Just like normal cartilage, the lab-grown material contains Type II collagen , and under the microscope the cells appear to be perfectly formed, with structures similar to those observed in samples of human-harvested cartilage. The study represents a giant step forward in the ability to generate new, endogenous cartilage tissue. In the not too distant future, it should be possible to use 3D bioprinting to generate cartilage based on a patient’s own, “backed-up” stem cells. This bioprinted tissue can be used to repair cartilage damage, or to treat osteoarthritis, in which joint cartilage degenerates and breaks down. The condition is very common – one in four Swedes over the age of 45 suffer from some degree of osteoarthritis. In theory, this research has created the opportunity to generate large amounts of cartilage, but one major issue must be resolved before the findings can be used in practice to benefit patients. “The structure of the cellulose we used might not be optimal for use in the human body. Before we begin to explore the possibility of incorporating the use of 3D bioprinted cartilage into the surgical treatment of patients, we need to find another material that can be broken down and absorbed by the body so that only the endogenous cartilage remains, the most important thing for use in a clinical setting is safety” explains Simonsson.


News Article | April 24, 2017
Site: phys.org

Two years ago, the Zika virus drew attention to microcephaly, a developmental disorder in which the brain and skull display inhibited growth. But there are other causes of microcephaly, such as congenital genetic diseases. Much is still unknown about brain development, but researchers at Utrecht University, in collaboration with their colleagues in Switzerland, have now new shed light on the molecules involved. The results of their research will be published in Nature Cell Biology.


News Article | April 24, 2017
Site: www.eurekalert.org

Two years ago, the Zika virus drew attention to microcephaly, a developmental disorder in which the brain and skull display inhibited growth. But there are other causes of microcephaly, such as congenital genetic diseases. Much is still unknown about brain development, but researchers at Utrecht University, in collaboration with their colleagues in Switzerland, have now new shed light on the molecules involved. The results of their research will be published in Nature Cell Biology.


News Article | April 19, 2017
Site: www.eurekalert.org

Neurons are the main cells in the nervous system. They process information by sending, receiving, and combining signals from around the brain and the body. All neurons have a cell body where molecules vital for its functioning and maintenance are produced. The axon, a long and slender extension that can reach one metre in length in humans, sends information from the nerve cell to other nerve cells. Neuronal survival is highly dependent on the transport of vital molecules within this axon. Research has shown that defects in the transport function in the axons play a key role in degenerative brain diseases such as Alzheimer. "Previous research examined transport processes in small areas of the axon, such as the very beginning or the very end. This left it unclear how the movement of molecules through the axon was regulated over long distances. In our study, we provide the first comprehensive map of transport in mammalian axons", says Casper Hoogenraad, Professor of Cell Biology at Utrecht University, explaining the relevance of this study. In most neurons, an area between the cell body and the axon called the 'axon initial segment' serves as a checkpoint: only some molecules can pass through it. This area has stumped scientists for more than a decade. Why should one type of molecule be able to pass through this area, while others cannot? The answer is to be found in the traffic regulator, a protein called MAP2. "With this discovery, we have answered a fundamental question about the unique functioning of nerve cells that has occupied scientists for a long time", lead author of the study Dr Laura Gumy says. The cell biologists from Utrecht first discovered that larger quantities of MAP2 accumulate between the cell body and the axon. When they removed MAP2 from the neuron, the normal pattern of molecule movement changed. Certain molecules suddenly ceased to enter the axon, whereas others accumulated in the axon instead of passing through to the cell body. This abnormal transport indicates that MAP2 is the driving force behind transport within the axon. The cell biologists from Utrecht University went on to make another very important discovery. Since axons are so long, transport in the neurons is carried out by sets of proteins - known as 'motor proteins' - that carry packages of other proteins on their back. As it turns out, MAP2 is able to switch a specific 'motor protein' on or off, like a car key. This means that MAP2 actually controls which packages of molecules may enter the axon and which may not. Targeting the activity of the transport engine allowed the researchers to make another interesting discovery: MAP2 is also able to control the delivery of molecules at specific points along the axon. "Transport within axons has been shown to fail in Alzheimer, Parkinson's disease and Huntington's disease, as well as in many other diseases. When the neuron is no longer able to control where molecules go, or is unable to get molecules to where they need to be, it cannot do its job. By understanding how transport works, we have laid the foundation for considering new targets and potential therapies for various neurodegenerative disorders", Casper Hoogenraad concludes.


Scientists at the University of Cambridge have succeeded in growing miniature functional models of the lining of the womb (uterus) in culture. These organoids, as they are known, could provide new insights into the early stages of pregnancy and conditions such as endometriosis, a painful condition that affects as many as two million women in the UK. CAMBRIDGE, 18-Apr-2017 — /EuropaWire/ — The mucosal lining inside the uterus is called the endometrium. Over the course of the menstrual cycle, its composition changes, becoming thicker and rich with blood vessels in preparation for pregnancy, but if the woman does not conceive, the uterus sheds this tissue, causing the woman’s period. A team from the Centre for Trophoblast Research, which this year celebrates its tenth anniversary, was able to grow the organoids in culture from cells derived from endometrial tissue and maintain the organoids in culture for several months, faithfully reproducing the genetic signature of the endometrium – in other words, the pattern of activity of genes in the lining of the uterus. They also demonstrated that the organoids respond to female sex hormones and early pregnancy signals, secreting what are collectively known as ‘uterine milk’ proteins that nourish the embryo during the first months of pregnancy. The findings of the study, funded by the Medical Research Council, the Wellcome Trust and the Centre for Trophoblast Research, are published today in the journal Nature Cell Biology. “These organoids provide a major step forward in investigating the changes that occur during the menstrual cycle and events during early pregnancy when the placenta is established,” says Dr Margherita Turco, the study’s first author. “These events are impossible to capture in a woman, so until now we have had to rely on animal studies.” “Events in early pregnancy lay the foundations for a successful birth, and our new technique should provide a window into this events,” adds Professor Graham Burton, Director of the Centre for Trophoblast Research, and joint senior author with Ashley Moffett of the study. “There’s increasing evidence that complications of pregnancy, such as restricted growth of the fetus, stillbirth and pre-eclampsia – which appear later in pregnancy – have their origins around the time of implantation, when the placenta begins to develop.” Research in animal species such as mice and sheep has shown that factors secreted by the endometrial glands are critical for enabling a developing fertilised egg (known as the ‘conceptus’) to implant into the wall of the uterus. There is also strong evidence that the conceptus sends signals to the endometrial glands that then stimulate the development of the placenta. In this way, the conceptus is able to stimulate its own development through a ‘dialogue’ with the mother; if it fails, the result is loss of the pregnancy or severe growth restriction of the fetus. Professor Burton and colleagues believe that using the organoids will allow them to investigate in greater detail how the conceptus communicates with the glands, identifying the full repertoire of factors released in response and testing their effects on placental tissues. His team will be collaborating with the Bourn Hall Clinic – a fertility clinic near Cambridge – to investigate whether parts of this circuitry are impaired or deficient in women experiencing difficulty in conceiving, and if so to devise potential new treatments. The technique also enables the researchers to grow organoids from endometrial cancer cells. As proof-of-principle, this will allow them to model and understand diseases of the endometrium, including cancer of the uterus and endometriosis. Organoid cultures have proven to be powerful tools for investigating the behaviour of other organ systems. Members of the Centre for Trophoblast Research are confident that their new advance will provide a much-needed window on events during the earliest stages of pregnancy, when the conceptus and mother first physically interact. Reference Turco, MY et al. Long-term, hormone-responsive organoid cultures of human endometrium in a chemically defined medium. Nature Cell Biology; 10 April 2017; DOI: 10.1038/ncb3516

Loading Cell Biology collaborators
Loading Cell Biology collaborators