The animal study, led by Matthias Tschöp, MD, professor in the University of Cincinnati (UC) endocrinology division, appears online ahead of print Sunday, June 6, 2010, in Nature Neuroscience.
"We have long thought that cholesterol is exclusively regulated through dietary absorption or synthesis and secretion by the liver," says Tschöp. "Our study shows for the first time that cholesterol is also under direct 'remote control' by specific neurocircuitry in the central nervous system."
The hormone ghrelin inhibits the melanocortin 4 receptor (MC4R) in the hypothalamus and is important for the regulation of food intake and energy expenditure. Tschöp and his team found that increased levels of ghrelin in mice caused the animals to develop increased levels of blood-circulating cholesterol. This, the authors say, is due to a reduction in the uptake of cholesterol by the liver.
The research team next tested the effects of genetically deleting or chemically blocking MC4R in the central nervous system. This test also yielded increased levels of cholesterol, suggesting that MC4R was the central element of the "remote control."
"We were stunned to see that by switching MC4R off in the brain, we could even make injected cholesterol remain in the blood much longer," says Tschöp, a researcher at UC's Metabolic Diseases Institute.
Cholesterol is a type of naturally occurring fat needed by the body, but too much cholesterol can lead to atherosclerosis, a buildup of plaque in the arteries. There are two types of cholesterol in humans―HDL (high-density lipoprotein) and LDL (low-density lipoprotein). LDL is considered the "bad" kind of cholesterol responsible for plaque buildup. HDL is the "good" kind that, in high levels, can prevent atherosclerosis.
Atherosclerosis can lead to heart attack. The American Heart Association estimates that a heart attack occurs every 34 seconds in the United States.
Due to the differences in the make-up of mice and human cholesterol, Tschöp and his team say more work is needed before their studies could be directly applied to humans, but they say their finding adds to a growing body of evidence for the central nervous system's direct control over essential metabolic processes.
This study was supported by a grant from the National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases.
Co-authors include Stephen Benoit, Joshua Bashford, William Davidson, Norm Granholm, Erin Grant, Susanna Hofmann, David Hui, Ruben Nogueiras, Diego Perez-Tilve, Paul Pfluger, Hilary Wilson-Perez and Stephen Woods, all from the University of Cincinnati; Myrtha Arnold from the Institute of Animal Science in Schwerzenbach, Switzerland; Andrew Butler and James Trevaskis from Pennington Biomedical Research Center in Louisiana; James Patterson and Mark Sleeman from Regeneron Pharmaceuticals; and Richard DiMarchi from Indiana University.
UC's Metabolic Diseases Institute, named in 2009, is located on UC's Reading Campus, formerly the Genome Research Institute, and is home to a team of researchers who focus on the genetic, molecular and cellular mechanisms of metabolic disorders, cancer and cardiovascular disease.
Dama Kimmon | EurekAlert!
Scientists learn more about how gene linked to autism affects brain
19.06.2018 | Cincinnati Children's Hospital Medical Center
Overdosing on Calcium
19.06.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
19.06.2018 | Physics and Astronomy
19.06.2018 | Life Sciences
19.06.2018 | Physics and Astronomy