News Release

UCR study says second-hand smoke affects healing

Findings suggests second-hand smoke also promotes scarring

Peer-Reviewed Publication

University of California - Riverside

Researchers at the University of California, Riverside have found that breathing "second-hand" smoke reduces the speed at which wounds heal, leading to greater levels of scarring.

The study published in the journal BMC Cell Biology this week may begin to explain why. According to the findings, when cells are exposed to smoke, their ability to move toward the site of damage is compromised.

The study, led by Professor Manuela Martins-Green, of the Department of Cell Biology and Neuroscience and her student Lina Wong, examined the effects of second-hand smoke on fibroblasts, cells that play a major role in wound healing. The UC Riverside research team also included graduate student Jo Ellen Feugate, undergraduate researcher Harry Miguel Green of Dr. Martins-Green's group, Professor Eugene A Nothnagel and Staff Research Associate Madhav Yadav of the Department of Botany and Plant Sciences.

In second-hand smoke, many components are more concentrated than in first-hand smoke. For example, the concentrations of nicotine, tar, nitric oxide and carbon monoxide levels are at least twice as high as those the smoker inhales.

Among the findings, they discovered that exposure to smoke altered the arrangement of the cells' cytoskeleton - increasing the cells' adhesive properties and thus reducing their mobility.

The research team bubbled smoke from the lit end of cigarettes through cell culture media to form a solution containing the major components of second-hand smoke. They then diluted the 'smoky media' until the smoke components reached the levels found in the tissues of passive smokers.

When they added this media to fibroblast cells cultured in vitro, the researchers saw that the cells became more elongated and that they separated from one another. By studying components of the cytoskeleton in more detail, the researchers saw that exposure to smoke increased the level of one particular cytoskeletal component, actin, inside the cell. It also increased the number of points at which the cell stuck to the Petri dish.

In the paper, titled "Effects of 'second-hand' smoke on structure and function of fibroblasts - cells that are critical for tissue repair and remodelling," the researchers wrote: "These effects can contribute to abnormal healing and may explain why people who are consistently exposed to 'second-hand' smoke suffer from slow healing and excessive scarring of wounds, much like smokers themselves."

During normal wound healing, fibroblasts migrate into the area of damaged tissue and secrete growth factors, cytokines and extra-cellular matrix components. If the cells are unable to migrate, they will remain concentrated at the edge of the wound, preventing the wound from closing properly. If, in addition, the fibroblasts deposit excess extra-cellular matrix components at the edge of the wound, abnormal scars are likely to form.

"These findings have led us to further our studies in a system that more closely mimics the in vivo environment. We are currently using a mouse model system and special chambers, where the mice smoke, to attempt to correlate our in vitro findings with in vivo results," wrote the researchers.

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Online Resources

The entire article is available free of charge according to BMC Cell Biology's Open Access policy via http://www.biomedcentral.com/bmccellbiol

The full text of this article is available at: http://www.biomedcentral.com/imedia/1095991185292039_manuscript.pdf

Manuela Martins-Green's Web site in the Department of Cell Biology and Neurosceince at UC Riverside is at: http://cbns.ucr.edu/index.php?content=people/faculty/martins-green/martins-green.html

For further information about this research contact Professor Manuela Martins-Green by email at mmgreen@urac1.ucr.edu or by phone on 909 787 2585

Alternatively, or for further information about BMC Cell Biology or Open Access publishing, contact Gemma Bradley, by phone on +44 (0)20 7323 0323 or email at press@biomedcentral.com.

The University of California, Riverside is a major research institution and a national center for the humanities. Key areas of research include nanotechnology, genomics, environmental studies, digital arts and sustainable growth and development. With a current undergraduate and graduate enrollment of more than 17,000, the campus is projected to grow to 21,000 students by 2010. Located in the heart of inland Southern California, the nearly 1,200-acre, park-like campus is at the center of the region's economic development. Visit www.ucr.edu or call 909-787-5185 for more information. Media sources are available at http://www.mediasources.ucr.edu/.

BMC Cell Biology (http://www.biomedcentral.com/bmccellbiol) is published by BioMed Central (http://www.biomedcentral.com), an independent online publishing house committed to providing Open Access to peer-reviewed biological and medical research. This commitment is based on the view that immediate free access to research and the ability to freely archive and reuse published information is essential to the rapid and efficient communication of science. BioMed Central currently publishes over 100 journals across biology and medicine. In addition to open-access original research, BioMed Central also publishes reviews, commentaries and other non-original-research content. Depending on the policies of the individual journal, this content may be open access or provided only to subscribers.


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