Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Vitamin D prevents clogged arteries in diabetics

14.11.2012
People with diabetes often develop clogged arteries that cause heart disease, and new research at Washington University School of Medicine in St. Louis suggests that low vitamin D levels are to blame.

In a study published Nov. 9 in the Journal of Biological Chemistry, the researchers report that blood vessels are less like to clog in people with diabetes who get adequate vitamin D. But in patients with insufficient vitamin D, immune cells bind to blood vessels near the heart, then trap cholesterol to block those blood vessels.


Bernal-Mizrachi lab

Low levels of vitamin D in people with diabetes appear to encourage cholesterol to build up in arteries, eventually blocking the flow of blood. In mice, immune cells adhering to the wall of a major blood vessel near the heart are loaded with cholesterol (shown in red).

“About 26 million Americans now have type 2 diabetes,” says principal investigator Carlos Bernal-Mizrachi, MD. “And as obesity rates rise, we expect even more people will develop diabetes. Those patients are more likely to experience heart problems due to an increase in vascular inflammation, so we have been investigating why this occurs.”

In earlier research, Bernal-Mizrachi, an assistant professor of medicine and of cell biology and physiology, and his colleagues found that vitamin D appears to play a key role in heart disease. This new study takes their work a step further, suggesting that when vitamin D levels are low, a particular class of white blood cell is more likely to adhere to cells in the walls of blood vessels.

Vitamin D conspires with immune cells called macrophages either to keep arteries clear or to clog them. The macrophages begin their existence as white blood cells called monocytes that circulate in the bloodstream. But when monocytes encounter inflammation, they are transformed into macrophages, which no longer circulate.

In the new study, researchers looked at vitamin D levels in 43 people with type 2 diabetes and in 25 others who were similar in age, sex and body weight but didn’t have diabetes.

They found that in diabetes patients with low vitamin D — less than 30 nanograms per milliliter of blood — the macrophage cells were more likely to adhere to the walls of blood vessels, which triggers cells to get loaded with cholesterol, eventually causing the vessels to stiffen and block blood flow.

“We took everything into account,” says first author Amy E. Riek, MD, instructor in medicine. “We looked at blood pressure, cholesterol, diabetes control, body weight and race. But only vitamin D levels correlated to whether these cells stuck to the blood vessel wall.”

Riek and Bernal-Mizrachi say what’s not yet clear is whether giving vitamin D to people with diabetes will reverse their risk of developing clogged arteries, a condition called atherosclerosis. They now are treating mice with vitamin D to see whether it can prevent monocytes from adhering to the walls of blood vessels near the heart, and they also are conducting two clinical trials in patients.

In one of those studies, the researchers are giving vitamin D to people with diabetes and hypertension to see whether the treatment may lower blood pressure. In the second study, African Americans with type 2 diabetes are getting vitamin D along with their other daily medications, and the research team is evaluating whether vitamin D supplements can slow or reverse the progression of heart disease.

Sometime in the next several months, the scientists hope to determine whether vitamin D treatment can reverse some of the risk factors associated with cardiovascular disease.

“In the future, we hope to generate medications, potentially even vitamin D itself, that help prevent the deposit of cholesterol in the blood vessels,” Bernal-Mizrachi explains. “Previous studies have linked vitamin D deficiency in these patients to increases in cardiovascular disease and in mortality. Other work has suggested that vitamin D may improve insulin release from the pancreas and insulin sensitivity. Our ultimate goal is to intervene in people with diabetes and to see whether vitamin D might decrease inflammation, reduce blood pressure and lessen the likelihood that they will develop atherosclerosis or other vascular complications.”

For more information on the current clinical studies involving vitamin D in people with diabetes, call study coordinator Robin Bruchas at (314) 362-0934.

Riek AE, Sprague JE, Timpson A, de las Fuentes L, Bernal-Mizrachi L, Schechtman KB, Bernal-Mizrachi C. Vitamin D suppression of endoplasmic reticulum stress promotes an anti-atherogenic monocyte/macrophage phenotype in type 2 diabetic patients. Journal of Biological Chemistry vol. 287 (46), pp. 38482-38494. Nov. 9, 2012

http://www.jbc.org/cgi/doi/10.1074/jbc.M112.386912

Funding for this research comes from the National Heart, Lung and Blood Institute (NHLBI), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Center for Research Resources (NCRR), National Center for Advancing Translational Sciences (NCATS), and NIH Roadmap for Medical Research of the National Institutes of Health (NIH). Support also comes from the American Diabetes Association, the Endocrine Society, the Endocrine Fellows Foundation and the Ruth L. Kirchstein National Research Service Award 2. NIH grant numbers are RO1 HO094818-0, P30DK079333, T32 HD043010, and UL1TRR000448/Sub-Award KL2TR000450.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.

Jim Dryden | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Life Sciences:

nachricht Moth takes advantage of defensive compounds in Physalis fruits
26.08.2016 | Max-Planck-Institut für chemische Ökologie

nachricht Designing ultrasound tools with Lego-like proteins
26.08.2016 | California Institute of Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Flexibel statt starr

Gezielter und effizienter Transport zellulärer Frachten durch physikalischen Mechanismus

Damit Zellen richtig funktionieren können, müssen Frachten innerhalb der Zelle ständig von einem Ort zum anderen transportiert werden, wobei es ähnlich zugeht...

Im Focus: Elektronen am Tempolimit

Elektronische Bauteile werden seit Jahren immer schneller und machen damit leistungsfähige Computer und andere Technologien möglich. Wie schnell sich Elektronen mit elektrischen Feldern letztendlich kontrollieren lassen, haben jetzt Forscher an der ETH Zürich untersucht. Ihre Erkenntnisse sind wichtig für die Petahertz-Elektronik der Zukunft.

Geschwindigkeit mag keine Hexerei sein, doch sie ist die Grundlage für Technologien, die nicht selten wie Magie anmuten. Moderne Computer etwa sind so...

Im Focus: Forscher beobachten, wie Chaperone defekte Proteine erkennen

Proteine, auch Eiweiße genannt, erfüllen in unserem Körper lebenswichtige Funktionen: Sie transportieren Stoffe, bekämpfen Krankheitserreger oder fungieren als Katalysatoren. Damit diese Prozesse zuverlässig funktionieren, müssen die Proteine eine definierte dreidimensionale Struktur annehmen. Molekulare Faltungshelfer, die sogenannten Chaperone, kontrollieren den Strukturierungsprozess. Ein Forscherteam unter der Beteiligung der Technischen Universität München (TUM) konnte nun herausfinden, wie Chaperone besonders gefährliche Fehler in diesem Strukturierungsprozess erkennen. Die Ergebnisse wurden im Fachmagazin "Molecular Cell" veröffentlicht.

Chaperone sind sozusagen die TÜV-Prüfer der Zelle. Es handelt sich um Proteine, die wiederum andere Proteine auf Qualitätsmängel untersuchen, bevor diese die...

Im Focus: Mikroskopieren mit einzelnen Ionen

Neuartiges Ionenmikroskop nutzt einzelne Ionen, um Abbildungen mit einer Auflösung im Nanometerbereich zu erzeugen

Wissenschaftler um Georg Jacob von der Johannes Gutenberg-Universität Mainz haben ein Ionenmikroskop entwickelt, das nur mit exakt einem Ion pro Bildpixel...

Im Focus: Streamlining accelerated computing for industry

PyFR code combines high accuracy with flexibility to resolve unsteady turbulence problems

Scientists and engineers striving to create the next machine-age marvel--whether it be a more aerodynamic rocket, a faster race car, or a higher-efficiency jet...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

VDE und IEEE veranstalten Weltkongress der Consumer-Elektronik auf der IFA

26.08.2016 | Veranstaltungen

IT-Sicherheit – Wettlauf gegen die Zeit

26.08.2016 | Veranstaltungen

Neue Ideen für die Schifffahrt

24.08.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Geothermieforschung: Bund fördert Projekt am Drilling Simulator Celle mit 3,8 Millionen Euro

26.08.2016 | Förderungen Preise

VDE und IEEE veranstalten Weltkongress der Consumer-Elektronik auf der IFA

26.08.2016 | Veranstaltungsnachrichten

Körperwärme als Stromquelle

26.08.2016 | Materialwissenschaften