Researchers in France have discovered that, though a tattoo may be forever, the skin cells that carry the tattoo pigment are not. Instead, the researchers say, the cells can pass on the pigment to new cells when they die. The study, which will be published March 6 in the Journal of Experimental Medicine, suggests ways to improve the ability of laser surgery to remove unwanted tattoos.
For many years, tattoos were thought to work by staining fibroblast cells in the dermal layer of the skin. More recently, however, researchers have suggested that macrophages--specialized immune cells that reside in the dermis--are attracted to the wound inflicted by the tattoo needle and gobble up the tattoo pigment just as they would normally engulf an invading pathogen or piece of a dying cell. In either case, it is assumed that the pigment-carrying cell lives forever, allowing the tattoo to be more or less permanent.
Green tattoo pigment is taken up by dermal macrophages (left). The pigment is released when these cells are killed (center) but, 90 days later, is taken back up into new macrophages that have replaced the old ones (right).
Credit: Baranska et al., 2018
Usage Restrictions: Reporters may freely use these materials in news coverage with the appropriate credit information.
A team of researchers led by Sandrine Henri and Bernard Malissen of the Centre d'Immunologie de Marseille-Luminy developed a genetically engineered mouse that allowed them to kill the macrophages that reside in the dermis and certain other tissues. Over the following few weeks, these cells are replaced by new macrophages derived from precursor cells known as monocytes.
The researchers found that dermal macrophages were the only cell type to take up pigment when they tattooed the mice's tails. Yet the tattoos' appearance did not change when the macrophages were killed off. The team determined that the dead macrophages release the pigment into their surroundings, where, over the following weeks, it is taken up by new, monocyte-derived macrophages before it can disperse.
This cycle of pigment capture, release, and recapture occurs continuously in tattooed skin, even when macrophages aren't killed off in a single burst. The researchers transferred a piece of tattooed skin from one mouse to another and found that, after six weeks, most of the pigment-carrying macrophages were derived from the recipient, rather than the donor, animal.
"We think that, when tattoo pigment-laden macrophages die during the course of adult life, neighboring macrophages recapture the released pigments and insure in a dynamic manner the stable appearance and long-term persistence of tattoos," Henri explains.
Tattoos can be removed by laser pulses that cause skin cells to die and release their pigment, which can then be transported away from the skin and into the body's lymphatic system.
"Tattoo removal can be likely improved by combining laser surgery with the transient ablation of the macrophages present in the tattoo area," says Malissen. "As a result, the fragmented pigment particles generated using laser pulses will not be immediately recaptured, a condition increasing the probability of having them drained away via the lymphatic vessels."
Baranska et al., 2018. J. Exp. Med. http://jem.
About the Journal of Experimental Medicine
The Journal of Experimental Medicine (JEM) features peer-reviewed research on immunology, cancer biology, stem cell biology, microbial pathogenesis, vascular biology, and neurobiology. All editorial decisions are made by research-active scientists in conjunction with in-house scientific editors. JEM provides free online access to many article types from the date of publication and to all archival content. Established in 1896, JEM is published by Rockefeller University Press. For more information, visit jem.org.
Visit our Newsroom, and sign up for a weekly preview of articles to be published. Embargoed media alerts are for journalists only.
Ben Short | EurekAlert!
The FiTS app now offering cooking videos as it expands its concept for long-term behavior modification
18.09.2018 | vitaliberty GmbH
The microbiota in the intestines fuels tumour growth
18.09.2018 | Technische Universität München
Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...
A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.
Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...
Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.
An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...
Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.
Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...
03.09.2018 | Event News
27.08.2018 | Event News
17.08.2018 | Event News
19.09.2018 | Life Sciences
19.09.2018 | Physics and Astronomy
19.09.2018 | Information Technology