Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists first to see trafficking of immune cells in beating heart

12.07.2012
Blood flow to the heart often is interrupted during a heart attack or cardiac surgery. But when blood flow resumes, the heart may still falter. That's because collateral damage can occur as blood re-enters the heart, potentially slowing recovery and causing future cardiac troubles.

Researchers investigating this type of secondary heart damage have been stymied by the inability to see in real time how restoring blood flow leads to inflammation that can cause further injury.


Working in mice, scientists at Washington University School of Medicine in St. Louis have used two-photon imaging to capture the first images of a beating heart at a resolution so detailed they can track individual immune cells swarming into the heart, causing inflammation. These immune cells, shown in green, are moving from the blood vessels in the heart into the heart muscle. Credit: Washington University in St. Louis

Now, working in mice, surgeons and scientists at Washington University School of Medicine in St. Louis, have captured the first images of a beating heart at a resolution so detailed they can track individual immune cells swarming into the heart muscle, causing inflammation.

The achievement is detailed in the July issue of the Journal of Clinical Investigation.

The researchers say that the imaging technique, called intravital two-photon imaging, is a powerful tool for understanding the inflammation that occurs when blood flow to the heart is temporarily stopped and later restarted.

"Inflammation is quite common after a heart attack, open-heart surgery, heart transplants and in atherosclerosis, and it can severely hamper recovery and lead to death," says senior author Daniel Kreisel, MD, PhD, a Washington University cardiothoracic surgeon who operates at Barnes-Jewish Hospital. "But little is known about how inflammation ramps up in the heart. Now that we have the ability to see all the cellular players involved, we can begin to think about new therapeutic targets for treatment."

Two-photon imaging has been used to image other organs in living mice but never the heart. Scientists had assumed that the flutter of the beating heart, which pulses about 500 times a minute in a mouse, would blur any images of individual cells.

"No one thought we could get clear images of cells inside the beating heart," says Wenjun Li, MD, research instructor of surgery and co-lead author with Ruben Nava, MD, and Alejandro Bribriesco, MD, both surgical residents at Barnes-Jewish Hospital. "But the images we captured are incredibly rich in detail, right down to the level of single cells. We think the principles underlying inflammation in the mouse heart will be applicable to humans."

One advantage of two-photon microscopy is the ability to penetrate deep into tissue, allowing scientists to image cells in the heart tissue.

Using the technique in mice that had undergone heart transplants or had a blood flow to the heart temporarily interrupted, the researchers saw that within minutes of restoring blood flow, specialized white blood cells, called neutrophils, rushed into the heart. (To see a video of neutrophils, shown in green, swarming into the beating heart of a mouse after a heart transplant, click here.)

Neutrophils are known to be a key driver of inflammation but scientists had never seen the trafficking of immune cells as they move from the circulation into the heart muscle, where the cells formed large clusters that cause tissue damage.

In addition, by blocking neutrophils from blood vessel walls, the researchers could markedly reduce the movement of these cells into the heart, preventing further injury.

Kreisel, Li and their colleagues collaborated with co-senior author Mark Miller, PhD, an assistant professor of pathology and immunology, who pioneered the use of two-photon microscopy for studying the trafficking of white blood cells in living mice. Together, they developed a way to stabilize the beating heart so they could obtain high-quality images of immune cell trafficking.

The same team also has used the technique to image immune cells in mouse lungs, which also move as the mice breathe but not to the same extent as the heart. And other scientists have used two-photon imaging to watch neutrophils travel into the skin, liver and other organs. Surprisingly, the researchers are finding that the trafficking of neutrophils differs from one organ to the next.

"Each organ seems to have its own requirements for signaling and attracting inflammatory cells," says Kreisel, who also is an associate professor of surgery. "It is as if each organ has its own zip code. Now, we have the ability to identify all the cells and signaling molecules that play a part in heart inflammation and can block particular pathways to see if we can prevent organ damage."

Li W, Nava RG, Bribriesco AC, Zinselmeyer BH, Spahn JH, Gelman AE, Krupnick AS, Miller MJ, Kreisel D. Intravital 2-photon imaging of leukocyte trafficking in beating heart. Journal of Clinical Investigation. July 2012.

The research is supported by the National Heart Lung and Blood Institute (1R01HL094601) and the National Institute of Allergy and Infectious Diseases (AI077600).

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.

Caroline Arbanas | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht Inselspital: Fewer CT scans needed after cerebral bleeding
20.03.2019 | Universitätsspital Bern

nachricht Building blocks for new medications: the University of Graz is seeking a technology partner
19.03.2019 | Karl-Franzens-Universität Graz

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>