Breaking News
August 16, 2018 - Study shows link between use of benzodiazepines and increased risk of Alzheimer’s disease
August 16, 2018 - Can manipulating gut microbes improve cardiac function in patients with heart failure?
August 16, 2018 - Hearts of newborn piglets can completely heal after heart attacks
August 16, 2018 - Ablating the mutant p53 gene in mice with colorectal cancer inhibits tumor growth
August 16, 2018 - Higher BMI in people with prediabetes related to evening preference and lack of sufficient sleep
August 16, 2018 - Using peripheral nerve blocks to treat facial pain may produce long-term pain relief
August 16, 2018 - Neural stem cells are the key to tail regeneration
August 16, 2018 - Study compares genetic and neural contributions to ADHD in children with or without TBI
August 16, 2018 - Adding energy drinks to alcohol may exacerbate negative effects of binge drinking
August 16, 2018 - Eye Examination Can Help Detect Abuse in Children
August 16, 2018 - Know the Difference: Rheumatoid Arthritis or Osteoarthritis?
August 16, 2018 - From ‘sea of mutations,’ two possible cancer links rise to the surface
August 16, 2018 - Does medical school take too long?
August 16, 2018 - Brown University researchers reveal key physical properties of ‘giant’ cancer cells
August 16, 2018 - Regular resistance training improves exercise motivation
August 16, 2018 - Feds urge states to encourage cheaper plans off the exchanges
August 16, 2018 - Seven activities that prevent you from getting quality sleep during summer
August 16, 2018 - Five ways to tell if your baby is getting enough milk from breastfeeding
August 16, 2018 - From Pigs to Peacocks, What’s Up With Those ‘Emotional-Support Animals’?
August 16, 2018 - Breast cancers enlist the help of normal cells to help them spread and survive
August 16, 2018 - Engaging with “high-need” patients outside the clinic
August 16, 2018 - Research illuminates how online forum may offer suicide prevention support for males
August 16, 2018 - Researchers identify way to grow immune cells at large scale for preventing cancer reoccurrence
August 15, 2018 - Keck Medicine of USC’s hospitals ranked among nation’s best for the 10th consecutive year
August 15, 2018 - Researchers compare existing approaches for automating diagnostic procedures of skin lesions
August 15, 2018 - Autism risk determined by health of mom’s gut, research reveals
August 15, 2018 - WELL for Life challenges you to explore the great outdoors
August 15, 2018 - ‘Zombie’ gene protects elephants from cancer, study finds
August 15, 2018 - Ebola outbreak in Congo spreads to active combat zone
August 15, 2018 - Study highlights pollution exposure of babies in prams
August 15, 2018 - Study provides insight into link between sleep apnea and lipid metabolism
August 15, 2018 - New study focuses on promise of gene therapy for Amish nemaline myopathy
August 15, 2018 - Researchers discover new approach to alleviate chronic itch
August 15, 2018 - Uncovering the Mysteries of MS: Medical Imaging Helps NIH Researchers Understand the Tricky Disease
August 15, 2018 - Autistic people at greater risk of becoming homeless – new research
August 15, 2018 - New imaging technique can spot tuberculosis infection in an hour
August 15, 2018 - Scientists study effects of eating breakfast versus fasting overnight before exercise
August 15, 2018 - Talking with children about suicide could save lives
August 15, 2018 - Grip strength of children predicts future cardiometabolic health
August 15, 2018 - New polyclonal immunotherapy successfully neutralizes Ebola virus
August 15, 2018 - Innovative oncofertility program launched by RMA of New York and Mount Sinai Health System
August 15, 2018 - Study shows efficacy, safety of AAV5-based gene therapy to treat sheep model of achromatopsia
August 15, 2018 - Simple score helps predict which hospitalized heart attack patients are at high risk of readmissions
August 15, 2018 - New discoveries show how protein droplets do more than keep cells’ interiors tidy
August 15, 2018 - Study shows impact of optimizing airport flight patterns on human health
August 15, 2018 - Life experiences of feeling unwanted or unplanned associated with attachment insecurity
August 15, 2018 - ACS Briefing Discusses Use of Lessons From Combat Care
August 15, 2018 - Study identifies distinct origin of ADHD in children with history of brain injury
August 15, 2018 - IgG3 antibody stops B cells from fighting pathogens in HIV patients
August 15, 2018 - Scientists discover key vulnerability of mixed lineage leukemia
August 15, 2018 - College students may experience pressures from secondary exposure to opioid abuse
August 15, 2018 - Powerful new microscope reveals inner workings of human cells with unprecedented clarity
August 15, 2018 - Married people who fight nastily more likely to suffer from leaky guts, study suggests
August 15, 2018 - Working Out After Baby – Drugs.com MedNews
August 15, 2018 - Rheumatoid Factor (RF) Test: MedlinePlus Lab Test Information
August 15, 2018 - ADHD linked to an increased risk of injury in children, study finds
August 15, 2018 - UIC researchers receive NIH funding to develop a better way to regenerate bone or tissues
August 15, 2018 - Study reveals how immune cells in the brain influence sexual behavior
August 15, 2018 - Researchers move closer to finding potential soft spot in drug-resistant tuberculosis
August 15, 2018 - Real-time dynamic monitoring of cell’s nucleus for effective cancer screening
August 15, 2018 - Lower rates of Medicare preventive care visits found in racial, ethnic minority older adults
August 15, 2018 - Scientists identify stress hormone as key factor in failure of immune system to inhibit leukemia
August 15, 2018 - Cytoplan introduces three new nutritional supplements
August 15, 2018 - Effective hemorrhage control critical for survival after motorsport accidents
August 15, 2018 - Sygnature Discovery announces ambitious expansion plan with addition of Alderley Park facility
August 15, 2018 - Dietary carbohydrates could lead to osteoarthritis, new study finds
August 15, 2018 - Male tobacco smokers have decreased number of cannabinoid CB1 receptors, study reveals
August 15, 2018 - Scientists explore ways for drug therapies to reach deadly brain tumors
August 15, 2018 - Rethinking fundamental rule of stroke care: ‘Time is brain!’
August 15, 2018 - Scientists reveal role of ‘junk DNA’ in cancer dissemination
August 15, 2018 - Google’s DeepMind AI could soon be diagnosing eye conditions
August 15, 2018 - Scientists trick the brain to embody the prosthetic limb
August 15, 2018 - Researchers focus on uncoupling obesity from diabetes
August 15, 2018 - Clinical study shows how EarlySense system effectively detects opioid-induced respiratory depression
August 15, 2018 - A class of proteins shown to be effective in reducing drug-seeking behaviors
August 15, 2018 - FundamentalVR launches first-of-its-kind SaaS software platform for surgical simulation
August 15, 2018 - Gemphire Announces Termination of Phase 2a Clinical Trial of Gemcabene in Pediatric NAFLD
August 15, 2018 - Rheumatoid arthritis in pregnancy associated with low birth weight and premature birth
August 15, 2018 - Study may help increase effectiveness of antibiotics against drug-resistant bacteria
August 15, 2018 - Analyzing resident-to-resident incidents in dementia may hold the key to reducing future fatalities
New studies on fat cell filling, history of biochemistry, and ketogenic diet

New studies on fat cell filling, history of biochemistry, and ketogenic diet

image_pdfDownload PDFimage_print

Brown tissue whitening causes cell death, inflammation

There’s more than one type of fat cell. Besides the white fat that stores triglycerides in lipid droplets in preparation for lean times later, mammals also have heat-generating brown fat, which acts more like a radiator than a storage closet. Brown fat cells are smaller, with more abundant mitochondria than white fat cells, and they hold a lot fewer lipids. In many models of obesity, brown adipose tissue converts to white tissue, with changes in the morphology and function of the cells.

In a recent paper in the Journal of Lipid Research, Petra Kotzbeck, Antonio Giordano and colleagues investigated what happens to brown fat cells after whitening. The researchers, based at the University of Graz, Austria, and the University of Ancona, Italy, found that whitened brown adipocytes enlarged by addition of lipids were more likely to die than white adipocytes of a comparable size. Whitened adipose tissue also had more macrophages, presumably there to clean up the dead cells, and more inflammation under way. The vulnerability of whitened brown adipocytes may explain why gaining fat in the abdomen, where most whitened brown fat is located, is worse for your health than gaining subcutaneous fat.
DOI: 10.1194/jlr.M079665

Syntaxin 17 promotes lipid droplet formation

Cells store energy in lipid droplets, and many such droplets are made in the liver, which plays an important role in coordinating fat metabolism. As new lipid droplets form within the endoplasmic reticulum, acyl coA synthetase 3, or ACSL3, is indispensable for helping them mature. ACSL3 turns free fatty acids into the neutral lipids that fill the lipid droplet.

In a recent article in the Journal of Lipid Research, Hana Kimura and colleagues studying droplet synthesis at Tokyo University of Pharmacy and Life Sciences in Japan report that the binding and scaffolding protein Stx17 is required to move ACSL3 to the nascent lipid droplet at mitochondria-associated membranes within the ER. This new role may explain why Stx17 is abundantly expressed in the liver and adipocytes.
DOI: 10.1194/jlr.M081679

Diet regulates a metabolite, but not in the brain

Ketogenic diets, which reduce carbohydrate intake and prompt the body to rely on fat-derived ketone bodies instead, are a popular treatment for epilepsy and thought to have neuroprotective effects on some other diseases. Mild caloric restriction is also believed to protect neurons. Researchers aren’t sure of the exact molecular mechanism of these diets, but Svenja Heischmann and colleagues at the University of Colorado in Denver have taken a step toward characterizing their effect on the brain.

In a study reported in the Journal of Lipid Research, researchers conducted a metabolomics analysis of both the plasma and brain tissue of mice eating normal or ketogenic chow. They subdivided each diet group into mice eating their fill or eating a restricted amount of chow. The researchers found that, in the bloodstream, kynurenine metabolism changed dramatically. Kynurenine, made from the amino acid tryptophan, can be converted into vitamin B3 or several other metabolites with effects on neurons. However, in the brain, the level of kynurenine changed relatively little.

The research suggests that, while tryptophan degradation is a target of the ketogenic diet, changes in plasma metabolism may not always cross the blood-brain barrier. The researchers intend to explore other metabolic changes in future publications.
DOI: 10.1194/jlr.M079251

Series brings the history of lipid science to light

Since 2013, the Journal of Lipid Research has been running a series of thematic reviews about what organizer Alfred H. Merrill Jr. originally dubbed the “Living History of Lipids.”

In his introduction to the series, Merrill described his motivation for starting the collection this way: “Much of what we know about lipids, and might be inclined to assume was easy to discover, arose from incredibly hard work, cleverly designed experiments, astonishing coincidences, and, sometimes, colossal accidents. This series of thematic reviews is intended to give glimpses into these stories. The authors will try to present the events and personalities as living histories where, when possible, readers will have a sense of stepping back in time.”

Thus far, the series has covered the lipid hypothesis of atherosclerosis, eight decades of bile acid chemistry, the discovery of essential fatty acids, what ApoE knockout and -in mice have taught us about atherogenesis, and early studies of arachidonic acid.

The latest installment, the sixth in the series, by Jean E. Vance of the University of Alberta, was published this spring. It is about the discovery, chemistry and biochemistry of two ubiquitous phosphoglycerolipids — phosphatidylserine and phosphatidylethanolamine.

PS and PE, as they’re known for short, captured Vance’s interest back when she was a postdoctoral researcher at the University of California, San Diego, working in the lab of Daniel Steinberg. (Steinberg, by the way, wrote the first installment of the “Living History” series.).

“My interest in what I felt were the rather neglected phospholipids, PS and PE, arose from some of my preliminary data suggesting that phospholipids could be compartmentalized into distinct pools in cells, perhaps due to specific inter-organelle lipid trafficking events,” Vance recalled. “(M)y research evolved into studying the biosynthesis, cell biology and functions of PS and PE in mammalian cells. Consequently, a major focus of my research was to understand the mechanism by which PS is transported from its site of synthesis in an ER domain — mitochondria-associated membranes, or MAM — to mitochondria for decarboxylation to PE.

Tagged with:

About author

Related Articles