The findings are published in the Feb. 24 online edition of The FASEB Journal, a publication of the Federation of American Societies of Experimental Biology.
Corresponding study author, Jane J. Kim is an assistant professor in the UCSD Department of Pediatrics and a member of the Pediatric Diabetes Research Center and Rady Children's Hospital-San Diego, a research and teaching affiliate of the UCSD School of Medicine. Kim said the findings represent the first documented evidence linking the sugar production to insulin and glucose metabolism problems associated with diabetes.
"It opens up a new perspective in understanding the causes of diabetes," said Kim. "Given the global epidemic of obesity and diabetes, we think that these findings suggest that evolutionary changes may have influenced our metabolism and perhaps increased our risk of the disease."
Type 2 diabetes is caused by both genetic and environmental factors, such as a fatty diet and lack of exercise, that result in progressively dysfunctional pancreatic beta cells, elevated blood sugar levels due to insulin resistance and eventual health complications, sometimes fatally so. Diabetes is an expanding problem, nationally and globally. In the United States, more than 25 million adults and children – almost nine percent of the population – have diabetes, according to the American Diabetes Association. Another 79 million Americans are estimated to be prediabetic. Worldwide, roughly 285 million people are believed to have the disease.
Sialic acids are sugar molecules found on the surfaces of all animal cells, where they act as vital contact points for interaction with other cells and with their surrounding environment. Virtually all mammals produce two types: N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc).
Humans are the exception. For reasons lost in the mists of evolution, a mutation in a gene called CMAH occurred 2 to 3 million years ago, inactivating an enzyme in humans that catalyzes production of Neu5Gc by adding a single oxygen atom to Neu5Ac.
Researchers compared two groups of mice: one with a functional CMAH gene, the other with an altered CMAH gene similar to the human mutation. Both groups of mice were fed a high-fat diet. Mice in both groups became obese and developed insulin resistance. However, only mice with the CMAH gene mutation experienced pancreatic beta cell failure – the cells that make and release insulin, a hormone that controls blood sugar levels.
Kim said the findings help refine understanding of why obese humans appear to be particularly vulnerable to type 2 diabetes, and also suggest that current animal models used to study diabetes may not accurately mirror the human condition. In clinical terms, she said further research to determine how sialic acid composition affects pancreatic beta cell function may reveal new strategies to preserve the cells, improve insulin production and prevent diabetes.
Co-authors of the study are Sarah Kavaler and Alice Jih, UCSD Department of Pediatrics and Rady Children's Hospital-San Diego; Hidetaka Morinaga and WuQuiang Fan, UCSD Department of Medicine; Maria Hedlund and Ajit Varki, UCSD departments of Medicine, Cellular and Molecular Medicine and UCSD Glycobiology Research and Training Center.
Funding support was provided by the National Institutes of Health.
Scott LaFee | EurekAlert!
NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)
High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses