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How Pufferfish Developed Its Unusual Spines

Pufferfish are known for their strange and extreme skin ornaments, but how they came to possess the spiky skin structures known as spines has largely remained a mystery. Now, researchers have identified the genes responsible for the evolution and development of pufferfish spines in a study published online on July 25, 2019 in iScience. The open-access article is titled “Evolution and Developmental Diversity of Skin Spines in Pufferfishes.” It turns out that the process is pretty similar to how other vertebrates get their hair or feathers--and might have allowed the pufferfish to fill unique ecological niches. "Pufferfish are some of the strangest fish in the ocean, particularly because they have a reduced skeleton, beak-like dentition and they form spines instead of scales--not everywhere, but just in certain patches around the body," says corresponding author Gareth Fraser (@garethjfraser), PhD, an Assistant Professor at the University of Florida. Dr. Fraser and his team followed the development of pufferfish spines in embryos. While the scientists had initially hypothesized that the spines formed from scales--that the pufferfish lost its scale component but retained the spine--they found that the spines are developmentally unique from scales. They also found that the development of pufferfish spines relies on the same network of genes that are commonly expressed within feathers and hairs of other vertebrate animals. "It just blows me away that regardless of how evolutionarily-different skin structures in animals are, they still use the same collection of genes during development," Dr. Fraser says.

Vitamin D Supplementation May Slow Diabetes Progression, New Study Suggests

Vitamin D supplementation may slow the progression of type 2 diabetes in newly diagnosed patients and those with prediabetes, according to a study published online on July 1, 2019 in the European Journal of Endocrinology. The open-access article is titled “Effects of 6-Month Vitamin D Supplementation on Insulin Sensitivity and Secretion: A Randomized, Placebo-Controlled Trial.” The study findings suggest that high-dose supplementation of vitamin D can improve glucose metabolism to help prevent the development and progression of diabetes. Type 2 diabetes is an increasingly prevalent disease that places a huge burden on patients and society and can lead to serious health problems including nerve damage, blindness, and kidney failure. People at high risk of developing type 2 diabetes (prediabetics) can be identified by several risk factors, including obesity or a family history of the disease. Although low vitamin D levels have previously been associated with an increased risk of developing type 2 diabetes, some studies have reported no improvement in metabolic function. However, these studies often had a low number of participants or included individuals with normal vitamin D levels at the start who were metabolically healthy, or who had long-standing type 2 diabetes. Whether vitamin D supplementation has any beneficial effect in patients with prediabetes or with newly diagnosed diabetes, especially in those who have low vitamin D levels, has remained uncertain. In this study, Dr. Claudia Gagnon, and colleagues from Université Laval in Quebec, examined the effect of vitamin D supplementation on glucose metabolism in patients newly diagnosed with type 2 diabetes or identified as at high risk of developing the condition.

Chemists Find Simplest Organic Molecules Can Self-Assemble to Give Cell-Like Structures Under Early Earth Conditions

Before life began on Earth, the environment likely contained a massive number of chemicals that reacted with each other more or less randomly, and it is unclear how things as complex as cells could have emerged from such chemical chaos. Now, a team led by Tony Z. Jia, PhD, of the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology and Kuhan Chandru, PhD, of the National University of Malaysia, has shown that simple α-hydroxy acids, like glycolic and lactic acid (which is used in common store-bought facial peels), spontaneously polymerize and self-assemble into polyester microdroplets when dried at moderate temperatures followed by rehydration, as might have happened along primitive beaches and river banks or in drying puddles. These form a new type of cell-like compartment which can trap and concentrate biomolecules like nucleic acids and proteins. These droplets, unlike most modern cells, are able to easily merge and reform and thus could have hosted versatile early genetic and metabolic systems potentially critical for the origins of life. The new work was published online on July 22, 2019 in PNAS in an article titled “Membraneless Polyester Microdroplets As Primordial Compartments at the Origins of Life.” Scientists from around the world are actively working to understand how life began. All modern Earth life, from bacteria to humans, is made up of cells. Cells are comprised of lipids, proteins, and nucleic acids, with the lipid forming the cell membrane, an enclosure that keeps the other components together and interfaces with the environment, exchanging food and waste. How molecular assemblages as complex as cells originally formed remains a mystery.

Molecular Sensor Scouts DNA Damage and Supervises Repair; Xeroderma Pigmentosa Connection

In the time it takes you to read this sentence, every cell in your body suffers some form of DNA damage. Without vigilant repair, cancer would run rampant, and now scientists at the University of Pittsburgh have gotten a glimpse of how one protein in particular keeps DNA damage in check. According to a study published online on July 22, 2019 in Nature Structural & Molecular Biology, a protein called UV-DDB--which stands for ultraviolet-damaged DNA-binding--is useful beyond safeguarding against the sun. This new evidence points to UV-DDB being a scout for general DNA damage and an overseer of the molecular repair crew that fixes it. The article is titled “Damage Sensor Role of UV-DDB During Base Excision Repair.” "If you're going to fix a pothole, you have to find it first. That's what UV-DDB does. It identifies DNA damage so that another crew can come in and patch and seal it," said study senior author Bennett Van Houten, PhD, Professor of Pharmacology and Chemical Biology at the Pitt School of Medicine and UPMC Hillman Cancer Center. Surveying 3 billion base pairs, packed into a nucleus just a few microns wide, is a tall order, Dr. Van Houten said. Not only is it a lot of material to search through, but it's wound up so tightly that many molecules can't access it. Keeping with the pothole analogy, one possible search strategy is to walk along the road, waiting to step in a hole. Another option is to fly around in a helicopter, but because molecules can't "see," this approach would require frequently landing to look for rough patches. To get around these shortcomings, UV-DDB combines both search strategies. "UV-DDB is like a helicopter that can land and then roll for a couple blocks," Dr. Van Houten said.

Exosomes May Have “Huge Relevance” to Treating & Diagnosing Developmental Brain Disorders; New Work at Scripps Suggests Cellular Cargo Transporters Play Profound Role in Creating Brain Cells & Circuits

Like overpacked suitcases unloaded from the underbelly of a jet, molecular satchels called exosomes are continuously deployed from all cells in the body—many brimming with an assortment of contents that another cell may unpack and use. By sending off these biological parcels, cells communicate with each other via shared proteins and genetic material. Once simply thought to be microscopic sacks of cellular “garbage,” exosomes are now understood to hold immense importance for our health. An outflowing of research in recent years has even shown they can transport molecules that are linked to the spread of cancer and neurodegenerative disorders such as Alzheimer’s. Yet, until recently, their role in brain development has remained a mystery. In new research published online on July 22, 2019 in PNAS, Hollis Cline (photo), PhD, and her colleagues at Scripps Research begin to close that knowledge gap by showing that exosomes are not only integral to the development of neurons and neural circuits, but they can restore health to brain cells affected by developmental disease. The open-access PNAS article is titled “Exosomes Regulate Neurogenesis and Circuit Assembly.” “During different stages of brain development, signaling between cells is absolutely essential,” says Dr. Cline, Co-Chair of the Department of Neuroscience at Scripps Research and Director of the Dorris Neuroscience Center at Scripps. “We found that exosomes are one of the ways cells communicate these signals.” Our bodies use spherical containers called “vesicles” to traffic different materials within and among cells. Exosomes are a type of vesicle tasked specifically with transporting various biological cargo—lipids, proteins, RNA,—from one cell to another. Dr.

Nunavik Inuit in Canada’s Arctic Are Genetically Unique & Share Variants That May Correlate with Brain Aneurysms, Among Distinct Genetic Signatures In Pathways Involving Lipid Metabolism & Cell Adhesion, Possibly Adaptive to High-Fat Diets & Extreme Cold

A new study has found that an Inuit population in Canada's Arctic are genetically distinct from any known group, and certain genetic variants in the population are correlated with brain aneurysm. Geographically isolated populations often develop unique genetic traits that result from their successful adaptation to specific environments. Unfortunately, these adaptations sometimes predispose them to certain health issues if the environment is changed. The genetic background of these populations are often poorly understood because they live far from scientific research centres. Canada's Inuit have a higher prevalence of cardiovascular disorders, as well as increased incidence of brain aneurysms, relative to the the general population. To learn about the possible genetic origin of these disorders, researchers at The Neuro (Montreal Neurological Institute and Hospital) of McGill University analyzed the genetic characteristics of 170 Inuit volunteers from Nunavik, a region of northern Quebec. This was done with approval from the Nunavik Nutrition and Health Committee in Kuujjuaq, Nunavik. Using exome sequencing and genome-wide genotyping, the researchers found several interesting traits among the Nunavik Inuit. They are a distinct genetic population, whose closest relatives are the Paleo-Eskimos, a people that inhabited the Arctic before the Inuit. The Nunavik Inuit have distinct genetic signatures in pathways involving lipid metabolism and cell adhesion. These may be adaptations to adjust to the high-fat diet and extreme cold of the Canadian north. One of these unique genetic variants correlates with a higher risk of brain aneurysm, also known as intracranial aneurysm, a weakening in the wall of a cerebral artery that causes ballooning of the artery.

New Study Explains Molecular Mechanism for Therapeutic Anti-Convulsive Effects of Cilantro

Herbs, including cilantro, have a long history of use as folk medicine anticonvulsants. Until now, many of the underlying mechanisms of how the herbs worked remained unknown. In a new study, researchers have uncovered the molecular action that enables cilantro to effectively delay certain seizures common in epilepsy and other diseases. The study, published online on July 16, 2019 in The FASEB Journal, explains the molecular action of cilantro (Coriandrum sativum) as a highly potent KCNQ channel activator This new understanding may lead to improvements in therapeutics and the development of more efficacious drugs. The article is titled “Cilantro Leaf Harbors A Potent Potassium Channel–Activating Anticonvulsant.” "We discovered that cilantro, which has been used as a traditional anticonvulsant medicine, activates a class of potassium channels in the brain to reduce seizure activity," said Geoff Abbott, PhD, Professor of Physiology and Biophysics at the UC-Irvine School of Medicine and principal investigator on the study. "Specifically, we found one component of cilantro, called dodecenal, binds to a specific part of the potassium channels to open them, reducing cellular excitability. This specific discovery is important as it may lead to more effective use of cilantro as an anticonvulsant, or to modifications of dodecenal to develop safer and more effective anticonvulsant drugs." Researchers screened cilantro leaf metabolites, revealing that one - the long-chain fatty aldehyde (E)-2-dodecenal - activates multiple potassium channels including the predominant neuronal isoform and the predominant cardiac isoform, which are responsible for regulating electrical activity in the brain and heart.

Diabetes-Associated Heart Failure Risk, High in General, Is Much Higher in Women Than in Men, New Global Study Shows

A global study of 12 million people has found that diabetes increases the risk of heart failure and this increase is greater for women than men. Researchers from The George Institute for Global Health headquartered in Australia determined that this differential was greater in type 1 than type 2 diabetes. Type 1 diabetes is associated with a 47% excess risk of heart failure in women compared to men, while type 2 diabetes has a 9% higher excess risk of heart failure for women than men. The findings published on online on July 18, 2019 (see article link below) and in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) highlights the need for further sex-specific research into diabetes and how the condition can potentially contribute to heart complications. The article is titled “Diabetes As a Risk Factor for Heart Failure in Women and Men: A Systematic Review and Meta-Analysis of 47 Cohorts Including 12 Million Individuals.” According to the International Diabetes Federation (IDF), currently 415 million adults world-wide live with diabetes - with approximately 199 million of them being women. The IDF expects by the year 2040 approximately 313 million women will be suffering from the disease. Diabetes is the ninth leading cause of death in women and claims 2.1 million female lives every year, more so than men. The number one leading cause of death for women is heart disease. "It is already known that diabetes puts you at greater risk of developing heart failure, but what our study shows, for the first time, is that women are at far greater risk - for both type 1 and type 2 diabetes," said lead author and research fellow Dr Toshiaki Ohkuma from The George Institute.

Scientists ID Cellular Connetion Between Diabetes and Blood Vessel Narrowing; Further Study Could Confirm Molecular Target for Possible Reduction of Blood Vessel Complications of Diabetes

A team of University of Calfornia (UC)-Davis Health scientists and physicians has identified a cellular connection between diabetes and one of its major complications -- blood vessel narrowing that increases risks of several serious health conditions, including heart disease and stroke. The authors hope their work leads to diabetes treatments -- beyond blood sugar monitoring and insulin therapy -- that target the molecular source of the disease’s damaging effects on the vascular system. The same team previously found that high blood glucose, the hallmark symptom of diabetes, activates an enzyme known as protein kinase A (PKA), which increases calcium channel activity and constricts blood vessels. "This was a surprise, because PKA is typically associated with blood vessel widening and wasn't really on our radar," said senior author Manuel Navedo, PhD, Professor of Pharmacology at UC Davis Health. "We wanted to understand the molecular processes that created this opposite reaction." For the new study, published online on June 4, 2019, in The Journal of Clinical Investigation, the Navedo lab team conducted a series of experiments on the effects of high glucose on cerebral blood vessels and arterial cells that control blood flow. The tests were conducted on a unique genetically modified mouse and two mouse models of diabetes that were developed at UC Davis for studies of cardiovascular health. The open-access article is titled “Adenylyl Cyclase 5-Generated cAMP Controls Cerebral Vascular ReactivityDuring Diabetic Hyperglycemia.”

Pioneering Study Shows Decrease in One Type of Dopapime Receptor in Wild Songbirds Under Captivity Stress

Dopamine is a chemical in the brain that is important for learning and memory. Louisiana State University (LSU) Department of Biological Sciences Assistant Professor Christine Lattin, PhD, and colleagues conducted this study of wild songbirds showing that dopamine is important in responding to chronic stressors, which can help wildlife conservation efforts in response to environmental stressors such as habitat destruction, natural disasters, extreme weather events and increases in predation. Dr. Lattin, who is the lead author on the study published online on July 18, 2019 in Nature Scientific Reports, applied a biomedical imaging technology called Positron Emission Tomography (PET) scans, that are used commonly on humans but rarely on wild animals, to quantify dopamine receptors in house sparrows. The open-access article is titled “In Vivo Imaging of D2 Receptors and Corticosteroids Predict Behavioural Responses to Captivity Stress in a Wild Bird.”"This Study Is Exciting Because It Is The first time PET scans have been used in wildlife to quantify dopamine receptors in the brain. Developing this technique has opened the door to being able to scan animals and release them back into the wild," she said. "We need to know how these wild birds are coping with stressors and responding to changes to the environment so we can understand how to best protect them." In addition to the biomedical imaging, Dr. Lattin and colleagues tracked changes in the birds' body mass and hormone levels, and observed their behavior using a remotely operated video camera to study wild house sparrows' response to captivity over four weeks. The birds were scanned after being brought in to the lab and then again four weeks later. By using PET scans, the scientists were able to study how the stress of captivity affected the birds over time.

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