Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mouse model reveals potential way to reduce cardiac deaths in kidney patients

31.03.2005


Scientists have identified an important link between kidney damage and cardiac problems, creating new possibilities for treating the primary cause of death in kidney disease patients.



Researchers tracked a chain reaction that leads from kidney damage to weakening of the skeleton to increased phosphorous in the blood. They showed that higher phosphorous levels were directly linked to vascular calcification, a stiffening of the smooth muscle cells that line blood vessels. Vascular calcification leads to enlargement of one of the heart’s four chambers, increased risk of congestive heart failure, heart attack and several other cardiac problems.

Mice treated with an experimental medication that alleviates the skeletal weakening brought on by kidney damage had normal phosphorous levels and decreased signs of vascular calcification.


"We already have treatments available that can control phosphorous levels in the blood, and those should be very helpful for kidney patients," says senior investigator Keith A. Hruska, M.D., the Ira M. Lang Professor of Nephrology and professor of pediatrics and of cell biology and physiology at Washington University School of Medicine in St. Louis. "The drug we used in the mice and other similar agents can treat both the phosphorous levels and skeletal weakening, and those drugs are just entering initial clinical trials."

The study will appear in the April issue of the Journal of the American Society of Nephrology.

Hruska, who is director of nephrology at St. Louis Children’s Hospital, has long been interested in the connections between kidney damage and bone weakening. He and other researchers have uncovered a complex network of links between the skeleton and the kidney. Hormones made in the kidney regulate activity in the skeleton and vice-versa.

Last year, Hruska showed that injections of bone morphogenetic protein-7 (BMP-7) could prevent bone weakening in mice whose kidneys had been damaged or removed.

For the new study, researchers worked with a mouse model of metabolic syndrome, a condition common among patients with chronic kidney disease that includes symptoms such as obesity, high blood pressure and insulin resistance. The condition, which is rapidly increasing in both adults and children, is also associated with higher risks of diabetes and heart disease.

The mice develop metabolic syndrome as a result of both a genetic modification and a high-fat, high-cholesterol diet. To simulate chronic kidney disease, scientists damaged or removed part of the kidney. This led to a shutdown of cells that regularly dismantle and rebuild bones, causing vascular calcification.

The body normally takes minerals like calcium and phosphorous circulating in the bloodstream and deposits them in the bones during bone reconstruction. With those processes shut down, scientists theorized, the bloodstream levels of minerals increase, raising pressure to deposit them elsewhere.

Hruska and his colleagues first showed that injection of BMP-7, previously shown to stop the bone disorder, also stopped vascular calcification. In another group of experimental mice, injections of a substance that binds to compounds with phosphorous but has no effect on the skeleton also stopped vascular calcification, proving that phosphorous was the key link.

"Serum phosphorous is a direct stimulus to the smooth muscle cells that line blood vessels, causing them to take on characteristics very similar to osteoblasts, the cells that form bone," Hruska explains.

The changed smooth muscle cells can deposit minerals outside their membranes, dramatically decreasing the flexibility of blood vessels and increasing the work the heart has to do to create a pulse.

"Vascular stiffness happens to patients with end-stage kidney failure when they go on dialysis, and it leads to many dangerous cardiovascular complications," Hruska says. "This study shows us that by treating the skeleton or otherwise decreasing phosphorous levels, we have the potential to produce a decrease in vascular calcification and marked improvements in cardiovascular outcome."

To follow up, Hruska plans a more direct study of the effects of BMP-7 on vascular calcification and further investigation of the skeleton-kidney links that lead to bone weakening in patients with kidney damage.

Michael C. Purdy | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>