Cells move as concentration shifts

Sheets of biological cells move along the organs they cover by altering the external concentrations of specific molecules

2013-07-29

(Press-News.org) What do wound healing, cancer metastasis, and bacteria colonies have in common? They all involve the collective displacement of biological cells. New research sheds some new light on the physical mechanisms provoking the displacement of a sheet of cell, known as an epithelium. It typically covers our organs including the stomach and intestine, as well as our epidermis. In a paper about to appear in EPJ E, Martine Ben Amar from Pierre and Marie Curie University in Paris explains the importance of understanding the displacement of the epithelium as a means of influencing the biological process involved in healing. And, ultimately, of helping to minimise scars.

In this study, Ben Amar aims at developing a predictive theoretical physics model based on calculations designed to account for experimental observations.

Her model focuses on particular types of displacement, which are due to molecules— referred to as morphogens—that the cells can feel. In fact, cells are sensitive to their concentration and are therefore attracted in their direction in a process called chemotaxis. Cells can also absorb these molecules at their surface as a means of modifying their concentration and therefore their displacement. In addition, the model takes into account physical parameters such as the substrate friction and the cohesion of the overall tissue.

Ben Amar found that her theory could be applied to better understand the irregularities found at the boundaries of the sheets, which are a signature of the collective behaviour of these cells, previously observed in recent in vitro biophysics experiments. Such irregularities could influence the quality of the future scar. This is important for the quality of vision in the case of cornea scars, and for a possible improvement in the bio-engineering of artificial tissues.

### Reference M. Ben Amar (2013), Chemotaxis migration and morphogenesis of living colonies, European Physical Journal E 36: 64, DOI 10.1140/epje/i2013-13064-5 For more information visit: http://www.epj.org

The full-text article is available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

New coating may help joint replacements bond better with bone

2013-07-29

COLUMBUS, Ohio—Broken bones and joint replacements may someday heal faster, thanks to an unusual coating for medical implants under development at The Ohio State University. Researchers here have found that bone cells grow and reproduce faster on a textured surface than they do on a smooth one—and they grow best when they can cling to a microscopic shag carpet made of tiny metal oxide wires. In tests, the wires boosted cell growth by nearly 80 percent compared to other surfaces, which suggests that the coating would help healthy bone form a strong bond with an implant ...

Cell phones could increase cancer risk

2013-07-29

Scientists have long been worried about the possible harmful effects of regular cellular phone use, but so far no study has managed to produce clear results. Currently, cell phones are classified as carcinogenic category 2b – potentially carcinogenic to humans – by the International Agency for Research on Cancer (IARC). A new Tel Aviv University study, though, may bring bad news. To further explore the relationship between cancer rates and cell phone use, Dr. Yaniv Hamzany of Tel Aviv University's Sackler Faculty of Medicine at Tel Aviv University and the Otolaryngology ...

Ice-free Arctic winters could explain amplified warming during Pliocene

2013-07-29

Year-round ice-free conditions across the surface of the Arctic Ocean could explain why the Earth was substantially warmer during the Pliocene Epoch than it is today, despite similar concentrations of carbon dioxide in the atmosphere, according to new research carried out at the University of Colorado Boulder. In early May, instruments at the Mauna Loa Observatory in Hawaii marked a new record: The concentration of carbon dioxide climbed to 400 parts per million for the first time in modern history. The last time researchers believe the carbon dioxide concentration ...

PTSD after traumatic events: Which teens are at risk?

2013-07-29

Boston, MA, July 29, 2013 -- While most children cannot be shielded from emotionally traumatic events, clinicians can target those who are most vulnerable to developing post-traumatic stress disorder (PTSD), according to a large study from Boston Children's Hospital. Findings appear online in the August issue of the Journal of the American Academy of Child & Adolescent Psychiatry, accompanied by an editorial. Researchers led by Katie McLaughlin, PhD, of the Departments of Pediatrics and Psychiatry at Boston Children's, analyzed data on 6,483 teen–parent pairs from the ...

Adolescents are what they don't eat, too

2013-07-29

PITTSBURGH -- Diets lacking omega-3 fatty acids—found in foods like wild fish, eggs, and grass-fed livestock—can have worsened effects over consecutive generations, especially affecting teens, according to a University of Pittsburgh study. Published in Biological Psychiatry, the Pitt team found that in a rodent model second-generation deficiencies of omega-3s caused elevated states of anxiety and hyperactivity in adolescents and affected the teens' memory and cognition. "We have always assumed that stress at this age is the main environmental insult that contributes ...

Like water for batteries

2013-07-29

PITTSBURGH—Objects made from graphite—such as lithium-ion batteries—are "hydrophobic," meaning that they "dislike" water. For decades this lack of likeability has presented significant challenges in terms of building more durable technological devices made with graphite—until now. It appears that past samples of graphite were likely contaminated by air, causing the samples to appear hydrophobic, according to a University of Pittsburgh study. The Pitt team has demonstrated—for the first time—these materials are actually intrinsically attracted to water or "hydrophilic." ...

Premature aging of immune cells in joints of kids with chronic arthritis, Pitt team says

2013-07-29

PITTSBURGH -- The joints of children with the most common form of chronic inflammatory arthritis contain immune cells that resemble those of 90-year-olds, according to a new study led by researchers at Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh School of Medicine. The findings, published in the August issue of Arthritis and Rheumatism, suggest that innovative treatment approaches could aim to prevent premature aging of immune cells. Juvenile idiopathic arthritis, or JIA, is the most prevalent rheumatic condition in the world and affects ...

Parents don't fully understand biobank research, study finds

2013-07-29

Researchers who collect genetic samples from children for medical research need to explain the process more clearly to parents, according to a new study that suggests many parents don't fully understand the finer details about how these samples will be used and stored. The study was published in June in Genetics in Medicine. Kim McBride, MD, MS, principal investigator in the Center for Cardiovascular and Pulmonary Research in The Research Institute at Nationwide Children's Hospital, and colleagues followed up with families enrolled in a genetic biobank—a storage facility ...

New study finds increase in nonfatal food-related choking among children in the US

2013-07-29

Choking is a leading cause of injury among children, especially for children 4 years of age and younger. A new study by researchers at the Center for Injury Research and Policy of The Research Institute at Nationwide Children's Hospital and colleagues at the Centers for Disease Control and Prevention examined nonfatal food-related choking among children 14 years of age or younger from 2001through 2009. During the nine-year study period, more than 12,000 children were treated each year in U.S. emergency departments for injuries from choking on food, which equals 34 children ...

Rattlesnakes and ticks, competition and cannibalism, and Fungi's potential

2013-07-29

Viper tick removal service Human cases of Lyme disease continue to rise in the United States. The bacterial disease—which, if untreated can cause significant neurological problems—is transmitted to people by black-legged ticks, which pick up the pathogen by feeding on infected animals, primarily small mammals such as mice. Previous studies have shown that when fewer predators of small mammals are present, the abundance of ticks goes up, resulting in an increase of Lyme infections in people. Edward Kabay, at East Chapel Hill High School, together with Nicholas Caruso ...

LAST 30 PRESS RELEASES:

How rice plants tell head from toe during early growth

Scientists design solar-responsive biochar that accelerates environmental cleanup

Construction of a localized immune niche via supramolecular hydrogel vaccine to elicit durable and enhanced immunity against infectious diseases

Deep learning-based discovery of tetrahydrocarbazoles as broad-spectrum antitumor agents and click-activated strategy for targeted cancer therapy

DHL-11, a novel prieurianin-type limonoid isolated from Munronia henryi, targeting IMPDH2 to inhibit triple-negative breast cancer

Discovery of SARS-CoV-2 PLpro inhibitors and RIPK1 inhibitors with synergistic antiviral efficacy in a mouse COVID-19 model

Neg-entropy is the true drug target for chronic diseases

Oxygen-boosted dual-section microneedle patch for enhanced drug penetration and improved photodynamic and anti-inflammatory therapy in psoriasis

Around the world, children’s cooperative behaviors and norms converge toward community-specific norms in middle childhood, Boston College researchers report