Navigation Links
New mechanical insights into wound healing and scar tissue formation
Date:12/17/2007

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."

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.


'/>"/>

Contact: Mary Parlange
mary.parlange@epfl.ch
41-216-937-022
Ecole Polytechnique Fdrale de Lausanne  
Source:Eurekalert

Related biology news :

1. Improving detection of nuclear smuggling goal of computer model of mechanical engineer
2. Stomach stem cell discovery could bring cancer insights
3. KGI professor contributes new insights on jumping genes
4. Study involving more than 100 scientists provides new insights on green algae
5. New insights into how lasers cut flesh
6. Tumor genome analysis unveils new insights into lung cancer
7. New insights into the fate of antiparasitics in manure and manured soils
8. Hinode: new insights on the origin of solar wind
9. Sea cucumbers fast track organ regrowth by healing their wounds
10. A step toward tissue-engineered heart structures for children
11. Researchers create system to build transplant tissue
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New mechanical insights into wound healing and scar tissue formation
(Date:1/20/2016)... , Jan. 20, 2016  Synaptics Incorporated ... human interface solutions, today announced sampling of S1423, ... for wearables and small screen applications including smartwatches, ... printers. Supporting round and rectangular shapes, as well ... excellent performance with moisture on screen, while wearing ...
(Date:1/15/2016)... , Jan. 15, 2016 Recent publicized breaches ... to find new ways to ensure data security and ... iOS and Android that ties a ... transforming it into a hardware authorization token. Customer service ... their fingerprint on their KodeKey enabled device to verify ...
(Date:1/13/2016)... 13, 2016 ... of the  "India Biometrics Authentication & ... (2015-2020)"  report to their offering.  ... announced the addition of the  "India ... Estimation & Forecast (2015-2020)"  report ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... , Febr. 10, 2016 /PRNewswire/ - BioAmber Inc. (NYSE: ... pleased to announce that Mitsui & Co. Ltd., its ... succinic acid plant, is investing an additional CDN$25 million ... increasing its stake from 30% to 40%.  Mitsui will ... bio-succinic acid produced in Sarnia , ...
(Date:2/10/2016)... Md. , Feb. 10, 2016  The Maryland ... Busch , has announced that University of Maryland School ... PhD, MBA and University of Maryland Medical System President ... of the "Speaker,s Medallion," the highest honor given to ... of Delegates. Dean Reece and Mr. ...
(Date:2/10/2016)... ASAE is introducing a hybrid membership model which will ... of joining or renewing through an organizational purchasing model. ... every employee in any size association or AMC office ... member benefits.   John H. Graham, IV ... allow organizations of any size and their employees to ...
(Date:2/10/2016)... RICHLAND, Wash., Feb. 10, 2016  IsoRay, Inc. (NYSE ... seed brachytherapy and medical radioisotope applications for the treatment ... cancers, today announced its financial results for the second ... December 31, 2015. --> ... second quarter of fiscal 2016, which ended December 31, ...
Breaking Biology Technology: