Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New mechanical insights into wound healing and scar tissue formation

18.12.2007
Cellular “Popeyes” respond to stress and transform into muscle-bound wound-healers

New research published today in the Journal of Cell Biology illuminates the mechanical factors that play a critical role in the differentiation and function of fibroblasts, connective tissue cells that play a role in wound healing and scar tissue formation.

When we are injured, the body launches a complex rescue operation. Specialized cells called fibroblasts lurking just beneath the surface of the skin jump into action, enter the provisional wound matrix (the clot) and start secreting collagen to close the wound as fast as possible. This matrix is initially soft and loaded with growth factors. The fibroblasts “crawl” around the matrix, pulling and reorganizing the fibers. The matrix grows stiffer, and at a certain point, the fibroblasts stop migrating and, like Popeye, change into powerful contractile cells, anchoring themselves to the matrix and pulling the edges of the wound together.

The research reported today reveals for the first time that a mechanical mechanism is crucial for this switch from migrating to contractile cells. To make this change, the fibroblasts need to get at their “spinach” – the growth factor sitting in the matrix which, once liberated, stimulates the production of smooth-muscle proteins. Previously, researchers postulated that the fibroblasts did this by digesting the matrix. But EPFL scientist Boris Hinz, doctoral student Pierre-Jean Wipff and their colleagues have discovered that the cells unlock the growth factor via a purely mechanical process. With experiments using novel cell culture substrates of varying rigidity, they found that at a certain point, the matrix is sufficiently rigid that cell-exerted force allows the growth factor to pop out, like candy from a wrapper. Once the growth factor is available, the fibroblast expresses the contractile proteins, sticks more firmly to the matrix and starts to contract, pulling the matrix tightly together. In the process it liberates yet more growth factor that in turn stimulates other fibroblasts to become contractile. The mechanical nature of the switch ensures that the contraction only develops when the matrix is “ready.”

... more about:
»Fibroblast »Matrix »SCAR »contractile »function »mechanical

Although this process will heal a wound quickly, if left unchecked, it can also lead to a buildup of fibrous tissue. Following trauma to vital organs such as the heart, lung, liver and kidney, overzealous fibroblasts can continue to build fibrous strands, leading to scar tissue buildup that can impair the organ’s function. This condition, called “fibrosis”, can be fatal. Fibroblasts are also the culprits in problems caused by implants – if the implant is too smooth, it never becomes properly incorporated into the connective tissue. But if it is too rough, scar tissue develops around it and it won’t function properly. Occasionally, following plastic surgery, unsightly excessive scar tissue can develop in the skin as well. The process can also cause problems in mesenchymal stem cell cultures – if the culture’s substrate is stiff, considerable efforts have to be made to prevent the stem cells from turning prematurely into fibroblasts instead of the desired cell type. Controlling the rigidity of the cell culture is therefore critical.

This new understanding of the mechanical nature of fibroblast activation could be used to reduce or prevent fibrosis from occurring, says Hinz, without inhibiting the growth factor, which serves many other vital functions in the body. There are several possibilities: “You could interfere with the way the cells grab onto the growth factor complex, you could interfere with their attachment points on the matrix, and you could interfere with their contractile forces so that the matrix never gets stiff enough to liberate the growth factor,” he suggests.

Mary Parlange | alfa
Further information:
http://www.epfl.ch

Further reports about: Fibroblast Matrix SCAR contractile function mechanical

More articles from Life Sciences:

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>