(Press-News.org) New research has found one of the smallest entities in the human genome, micro-RNA, could increase the risk of limb amputation in diabetic patients who have poor blood flow.
The study by Dr Andrea Caporali and colleagues in Professor Costanza Emanueli's research group in the Regenerative Medicine Section of the School of Clinical Sciences at the University of Bristol was funded by the Medical Research Council and is published online in Circulation: Journal of the American Heart Association.
The research group have shown in an experimental cell study that conditions mimicking diabetes and a lack of blood supply to a tissue increased a particular miRNA (miRNA-503) and impaired the ability of endothelial cells, which line the interior surface of blood vessels. Micro-RNAs (miRNAs) are small sections of ribonucleic acid (RNA) that can inhibit many genes.
Alternatively, slowing down miRNA-503 improved the capability of endothelial cells to duplicate and form into networks of small blood vessels. The researchers showed that microRNA-503 reduces cell growth and prevents the formation of blood vessels by direct binding and inhibition of cyclin E1 and Cdc25 mRNA.
Costanza Emanueli, Professorial Research Fellow in Vascular Pathology & Regeneration, said: "Because each miRNA can regulate many genes, they represent an exciting new target to correct diseases that have complex underlying mechanisms, like diabetes, rather than trying to target one specific gene. Our study is the first to provide evidence for a role of miRNAs in diabetes-induced defects in reparative angiogenesis."
The team subsequently investigated miR-503 and target gene expression in muscular specimens from the amputated ischaemic legs of diabetic patients. As controls, calf biopsies of non-diabetic and non-ischemic patients undergoing saphenous vein stripping were used. In diabetic muscles, miR-503 expression was remarkably higher, and plasma miR-503 levels were also elevated in the diabetic subjects.
Finally, using mouse models of diabetes and limb ischaemia, the researchers found that inhibition of the miRNA-503 (using a "decoy miRNA") could restore-post-ischaemic blood flow recovery. The findings of this study highlight important clinical implications of miR-503 in diabetes-associated vascular complications.
In early diabetes, high blood glucose levels damage blood vessels leading to lack of blood flow (ischaemia). Such ischaemic complications are the leading cause of disease and death in diabetic patients. In limbs, lack of blood flow can result in non-healing ulcers and, in diabetic patients, the ischaemic disease follows an unalterable course and limb amputation is too often the eventual remedy.
Tissues can recover from lack of blood flow by new blood vessel growth (angiogenesis), which restores blood supply to the tissue (reperfusion). However, diabetes harms the restoration of the flow of blood to a previously ischemic tissue, by mechanisms that are not fully understood, and so a better understanding of the molecular mechanisms underpinning diabetes-associated vascular complications is urgently needed to improve therapeutic options.
INFORMATION:
Paper: Deregulation of microRNA-503 contributes to diabetes-induced impairment of endothelial function and reparative angiogenesis after limb ischemia, Andrea Caporali, Marco Meloni, Christine Völlenkle, Desiree Bonci, Graciela B Sala-Newby, Roberta Addis, Gaia Spinetti, Sergio Losa, Rachel Masson, Andrew H Baker, Reuven Agami, Carlos le Sage, Gianluigi Condorelli, Paolo Madeddu, Fabio Martelli, Costanza Emanueli, Circulation, published online January 10, 2011.
MicroRNAs could increase the risk of amputation in diabetics
2011-01-13
ELSE PRESS RELEASES FROM THIS DATE:
Some school social workers don't feel prepared to manage cyberbullying, study finds
2011-01-13
ATHENS, Ohio (Jan. 12, 2011) – Some school social workers report that they don't feel equipped to handle incidents of cyberbullying among teens.
A new Ohio University-led survey of 399 members of the 11-state Midwest School Social Work Council found that while nearly all agreed that cyberbullying can cause psychological harm— including suicide—and deserved more attention from schools, just more than half felt empowered to deal with the issue. In contrast, other research on traditional bullying suggests that 86 percent of school staff members are confident in their ability ...
Hold the Red Bull: Energy drinks don't blunt effects of alcohol, study finds
2011-01-13
Marketing efforts that encourage mixing caffeinated "energy" drinks with alcohol often try to sway young people to believe that caffeine will offset the sedating effects of alcohol and increase alertness and stamina.
But a new study led by researchers from the Boston University School of Public Health [BUSPH] and the Center for Alcohol and Addiction Studies at Brown University has found that the addition of caffeine to alcohol -- mixing Red Bull with vodka, for example -- has no effect on enhancing performance on a driving test or improving sustained attention or reaction ...
Climate disasters: New Baylor study explores how people respond
2011-01-13
New results from a Baylor University study show that different behaviors and strategies lead some families to cope better and emerge stronger after a weather-related event.
Dr. Sara Alexander, an applied social anthropologist at Baylor who conducts much of her research in Central America, studied different households in several coastal communities in Belize. While climate change has been an emerging topic of interest to the world community, little scientific data exists on exactly how people respond to different climate-related "shocks" and events such as more intense ...
Toronto astronomers among those announcing first scientific results of Planck satellite mission
2011-01-13
University of Toronto astronomers are in Paris this week as part of an international conference announcing the first scientific results of the Plank space telescope mission.
Launched in May 2009, the telescope has nearly completed three of its four planned surveys of the entire sky, providing astronomers a glimpse of conditions near the beginning of the Universe and providing data that will help answer the big questions: How was the Universe formed? How has it evolved to its present form? And what shape will it take in future?
"Planck has worked flawlessly to give us ...
New Baylor study explores how partners perceive each other's emotion during a relationship fight
2011-01-13
Some of the most intense emotions people feel occur during a conflict in a romantic relationship. Now, new research from Baylor University psychologists shows that how each person perceives the other partner's emotion during a conflict greatly influences different types of thoughts, feelings and reactions in themselves.
Dr. Keith Sanford, a clinical psychologist and an associate professor of psychology and neuroscience at Baylor, College of Arts and Sciences, and his research team studied 105 college students in romantic relationships as they communicated through different ...
New responsive click-track software lets drummers set their own pace
2011-01-13
New software has been developed at Queen Mary, University of London's Centre for Digital Music, giving drummers the freedom to speed up or slow down the pace of any pre-programmed music, the material following their lead.
It means that drummers will no longer have to keep time with a click track and the set beat of pre-recorded tracks that are used during many live performances and studio sessions.
The software has been developed by Dr Andrew Robertson from Queen Mary, University of London's School of Electronic Engineering and Computer Science. Dr Robertson's work ...
Musical chills: Why they give us thrills
2011-01-13
Scientists have found that the pleasurable experience of listening to music releases dopamine, a neurotransmitter in the brain important for more tangible pleasures associated with rewards such as food, drugs and sex. The new study from The Montreal Neurological Institute and Hospital – The Neuro at McGill University also reveals that even the anticipation of pleasurable music induces dopamine release [as is the case with food, drug, and sex cues]. Published in the prestigious journal Nature Neuroscience, the results suggest why music, which has no obvious survival value, ...
Some heart attack rates declining and survival improving
2011-01-13
New York, NY, January 12, 2011 – Coronary syndromes vary in severity, ranging from unstable angina, non-ST segment elevation myocardial infarction (NSTEMI), to ST-segment elevation myocardial infarction (STEMI), the most severe diagnosis. Little data exist about changing trends in acute myocardial infarction and whether death rates are increasing or decreasing. In a study published in the January 2011 issue of The American Journal of Medicine, investigators found that STEMI rates decreased and one-year post-discharge death rates decreased in NSTEMI and STEMI patients.
"The ...
'Thirdhand smoke' may be bigger health hazard than previously believed
2011-01-13
Scientists are reporting that so-called "thirdhand smoke" — the invisible remains of cigarette smoke that deposits on carpeting, clothing, furniture and other surfaces — may be even more of a health hazard than previously believed. The study, published in ACS' journal, Environmental Science & Technology, extends the known health risks of tobacco among people who do not smoke but encounter the smoke exhaled by smokers or released by smoldering cigarette butts.
Yael Dubowski and colleagues note that thirdhand smoke is a newly recognized contributor to the health risks of ...
Scientific evidence supports effectiveness of Chinese drug for cataracts
2011-01-13
Scientists are reporting a scientific basis for the long-standing belief that a widely used non-prescription drug in China and certain other countries can prevent and treat cataracts, a clouding of the lens of the eye that is a leading cause of vision loss worldwide. Their study appears in Inorganic Chemistry, an ACS journal.
In the study, Tzu-Hua Wu, Fu-Yung Huang, Shih-Hsiung Wu and colleagues note that eye drops containing pirenoxine, or PRX, have been reputed as a cataract remedy for almost 60 years. Currently, the only treatment for cataracts in Western medicine ...