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 Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg

nachricht Bio-fabrication of Artificial Blood Vessels with Laser Light
28.08.2015 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Meeresinseln als Heimat einmaliger Pflanzenarten

Warum leben in manchen Ökosystemen auffallend viele, in anderen Ökosystemen nur wenige Pflanzenarten? Wie kommt es, dass einige Arten jeweils nur in einer bestimmten, klar abgrenzbaren Region der Erde zuhause sind? Mit diesen Fragen hat sich Dr. Manuel Steinbauer in einer Reihe wissenschaftlicher Studien an der Universität Bayreuth befasst. Für seine Forschungsarbeiten wird der Bayreuther Ökologe, der zurzeit als Postdoc an der dänischen Universität Aarhus forscht, mit dem diesjährigen Wilhelm Pfeffer-Preis der Deutschen Botanischen Gesellschaft (DBG) ausgezeichnet. Der Preis ist mit 2.500 Euro dotiert.

Wenn es darum geht, den Gründen für die Verbreitung pflanzlicher Arten auf die Spur zu kommen und theoretische Erklärungsansätze zu überprüfen, sind...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: Optische Schalter - Lernen mit Licht

Einem deutsch-französischen Team ist es gelungen, einen lichtempfindlichen Schalter für Nervenzellen zu entwickeln. Dies ermöglicht neue Einblicke in die Funktionsweise von Gedächtnis und Lernen, aber auch in die Entstehung von Krankheiten.

Lernen ist nur möglich, weil die Verknüpfungen zwischen den Nervenzellen im Gehirn fortwährend umgebaut werden: Je häufiger bestimmte Reizübertragungswege...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Membranprotein in Bern erstmals entschlüsselt

Dreidimensionale (3D) Atommodelle von Proteinen sind wichtig, um deren Funktion zu verstehen. Dies ermöglicht unter anderem die Entwicklung neuer Therapieansätze für Krankheiten. Berner Strukturbiologen ist es nun gelungen, die Struktur eines wichtigen Membranproteins zu entschlüsseln – dies gelingt relativ selten und ist eine Premiere in Bern.

Membranproteine befinden sich in den Wänden der Zellen, den Zellmembranen, und nehmen im menschlichen Körper lebenswichtige Funktionen wahr. Zu ihnen gehören...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Fehlermeldungen des Gehirns auf der Spur

31.08.2015 | Veranstaltungen

Risiken für die psychische Entwicklung im Fokus

31.08.2015 | Veranstaltungen

Erforschung von Sauerstoffminimumzonen: Internationales Expertenteam erarbeitet Weißbuch

31.08.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Forschungsschwerpunkt Medienkonvergenz untersucht Rolle des Internets für Entwicklung Jugendlicher

31.08.2015 | Studien Analysen

Meeresinseln als Heimat einmaliger Pflanzenarten

31.08.2015 | Biowissenschaften Chemie

Fehlermeldungen des Gehirns auf der Spur

31.08.2015 | Veranstaltungsnachrichten