Breaking News
November 21, 2018 - Many people underestimate the impact of sprains, say foot scientists
November 21, 2018 - Lower levels of protein make squamous carcinoma cells more invasive
November 21, 2018 - Study highlights a new predictor of type 2 diabetes
November 21, 2018 - New low-cost injectable hydrogel could help wounds heal faster
November 21, 2018 - Merck Announces Winners of 2018 Life Science Awards
November 21, 2018 - Amount of weight regain after bariatric surgery helps predict health risks
November 21, 2018 - Heart failure patients with stronger hearts have more depressive symptoms, lower quality of life
November 21, 2018 - Women can be as resilient as men in undertaking arduous physical activity
November 21, 2018 - Receptor structure could be key to developing new osteoporosis drugs
November 21, 2018 - Researchers identify human white matter pathway associated with individual variability in human stereoacuity
November 21, 2018 - Vitamin D critical to early development of vertebrates, study suggests
November 21, 2018 - Myriad biological, societal factors that impact CKD severity for children of African descent
November 21, 2018 - Isofol Announces Initiation of a Pivotal Phase 3 Clinical Trial of arfolitixorin for the Treatment of Metastatic Colorectal Cancer
November 21, 2018 - Experts offer more clarity on managing common ankle fractures
November 21, 2018 - About 300 million bits of DNA are missing from basic reference genome, report scientists
November 21, 2018 - Study explores how the moving brain processes visual information
November 21, 2018 - Biomedical engineers stop cancer cells from moving and spreading
November 21, 2018 - Gut protein mutations protect against spikes in blood glucose levels
November 21, 2018 - First probabilistic atlas of thalamus nuclei to better understand the brain
November 21, 2018 - Peanut allergies could soon have a drug treatment
November 21, 2018 - Vanderbilt researchers isolate antibody that can neutralize West Nile virus
November 21, 2018 - KHN’s ‘What the Health?’ Health nerd books for the holidays
November 21, 2018 - MDMA could help gain trust but does not make one naive find researchers
November 21, 2018 - Study uncovers new mechanism controlling the master cancer regulator
November 21, 2018 - Online communication technologies could stave off depression among seniors, shows study
November 21, 2018 - FDA Approves Gamifant (emapalumab-lzsg) for Primary Hemophagocytic Lymphohistiocytosis
November 21, 2018 - Artificial intelligence predicts treatment effectiveness
November 21, 2018 - A bicyclist’s road to recovery after traumatic brain injury
November 21, 2018 - New research project to combat obesity, type 2 diabetes receives NIH funding
November 21, 2018 - Humans play key role in distribution and transmission of Bartonella bacteria
November 21, 2018 - First modeling system developed for testing age-specific human immune responses to vaccines
November 21, 2018 - FDA Alert: Gilenya (fingolimod): Drug Safety Communication
November 21, 2018 - Uric Acid Test: MedlinePlus Lab Test Information
November 21, 2018 - Researchers use genetics to predict response to antipsychotic medications
November 21, 2018 - Proposal to include the price of drugs in television ads is flawed, Stanford scholar writes
November 21, 2018 - Disrupting reproduction strategy of disease-causing parasites could help fight malaria
November 20, 2018 - ACAAI: Almost 2 Percent of Children Have Milk Allergy
November 20, 2018 - Congenital anomalies of kidney and urinary tract – Genetics Home Reference
November 20, 2018 - Can video games improve the health of older adults with schizophrenia?
November 20, 2018 - Can flicking a molecular switch restore the aging immune system’s competence?
November 20, 2018 - Restek launches new Oregon cannabis pesticide standards
November 20, 2018 - Health sector coalition urges Government to safeguard patients in future UK-EU relationship
November 20, 2018 - Study evaluates second-hand marijuana smoke exposure among children
November 20, 2018 - Scientists identify three genes responsible for recurrent molar pregnancies
November 20, 2018 - Researchers identify multisystem disorder caused by bi-allelic variants in CCDC47 gene
November 20, 2018 - Dining Out With Allergies Is Tough, But These Steps Can Help
November 20, 2018 - Breastfeeding protects infants from antibiotic-resistant bacteria
November 20, 2018 - AI matched, outperformed radiologists in screening X-rays for certain diseases | News Center
November 20, 2018 - Adolescents increasingly choose marijuana over cigarettes, alcohol
November 20, 2018 - World’s first medical imaging scanner produces diagnostic scan of the whole human body
November 20, 2018 - Cytocybernetics receives NIMH award to move into neuronal drug development
November 20, 2018 - Researchers discover new information on pathological mechanisms of Alzheimer’s disease
November 20, 2018 - ‘Unknown’ enzyme may be key to new treatment for inflammatory diseases
November 20, 2018 - Recreational drug may help people regain trust in others
November 20, 2018 - Researchers identify gene vital for post-stroke recovery
November 20, 2018 - Scientists identify novel target for neuron regeneration, functional recovery in spinal cord injury
November 20, 2018 - Potential new therapeutic approach developed for synovial sarcoma
November 20, 2018 - Skeletal imitation reveals how bones grow atom-by-atom
November 20, 2018 - Autism behaviors show unique brain network fingerprints in infants
November 20, 2018 - Location matters for inflammation clearance
November 20, 2018 - Towards finding a druggable cancer target
November 20, 2018 - Ultragenyx Announces Intent to Submit New Drug Application to U.S. FDA for UX007 for the Treatment of Long-chain Fatty Acid Oxidation Disorders in Mid-2019
November 20, 2018 - Cooling ‘brains on fire’ to treat Parkinson’s
November 20, 2018 - Less pollution could increase the average lifespan of Copenhageners by an entire year in 2040
November 20, 2018 - Abramson Cancer Center becomes the 28th member institution of National Comprehensive Cancer Network
November 20, 2018 - The plug and play time-resolved spectrometer from PicoQuant
November 20, 2018 - Breakthrough technology offers new hope to people with glaucoma, retinitis and macular degeneration
November 20, 2018 - New report highlights key focus areas to help cancer screening realize its full potential
November 20, 2018 - International experts to discuss strategies to maintain spatial orientation in old age
November 20, 2018 - Low-protein, high-carb diet may promote healthy brain ageing
November 20, 2018 - Scientists discover new inhibitor that decreases lung inflammation
November 20, 2018 - Participation project calls for relaxing research ban on germline interventions
November 20, 2018 - Karyopharm’s Selinexor Receives Fast Track Designation from FDA for the Treatment of Patients with Relapsed or Refractory Diffuse Large B-cell Lymphoma
November 20, 2018 - Arthritis by the Numbers: Book of Trusted Facts & Figures
November 20, 2018 - Drug homing method helps rethink Parkinson’s
November 20, 2018 - AHF commends the passage of global AIDS funding in the House, calls for swift approval
November 20, 2018 - The search for new psychiatric disorder treatments
November 20, 2018 - New research offers hope for simpler way to diagnose and treat cancer
November 20, 2018 - Study sheds light on the infection mechanism of influenza virus
November 20, 2018 - Storage failures of eggs and embryos gain a new perspective
Biochemist, physicist team to see antibacterial TCS deform mitochondria

Biochemist, physicist team to see antibacterial TCS deform mitochondria

image_pdfDownload PDFimage_print
Credit: University of Maine

Grocery shopping can be an illuminating chore for a toxicologist.

Julie Gosse, a University of Maine associate professor of molecular and biomedical sciences, has scanned the supermarket aisles for products that contain triclosan (TCS), a synthetic antibacterial agent.

Since the ’90s, TCS has been in a slew of consumer products, including facial cleansers, toothpaste, mouthwash and hand sanitizers.

For years, Gosse has studied TCS, which for decades also has been used as a hospital scrub to reduce risk of infection.

She became interested in examining triclosan when listening to a talk by Environmental Protection Agency scientist Susan Richardson and noting that the molecular structure of TCS resembles the molecular structure of dioxins, which are toxic environmental pollutants.

In 2016, the Food and Drug Administration banned triclosan from consumer bar soaps, liquid soaps and body washes. At that time, the FDA challenged manufacturers to either prove TCS was more effective at killing germs than plain soap, or to remove it from their soap product within a year.

The antimicrobial agent, which is readily absorbed into the skin and the lining of the mouth, has recently been found to have detrimental effects on human fertility, development, thyroid function and immunology, and has been associated with increased occurrence of asthma.

Then, about six months ago, the FDA also announced a ban on products such as hand washes and antiseptic rubs containing TCS that are used in medical settings.

There’s no such ban on Colgate Total, the popular toothpaste that contains TCS. That’s because it’s been found to be more effective at treating gingivitis than toothpaste without it.

Gingivitis is an important health concern as it can lead to tooth loss. And research has indicated the bacteria that causes periodontitis can enter a person’s bloodstream and harm the heart and lungs.

Gosse understands why people with gingivitis would use Colgate Total; she just wants millions of people without gingivitis who also use the product to be aware of possible risks.

“Our job is to do the best science we can do and make people aware,” she says. “As scientists, we communicate our findings, and the public or companies or government decides what they should do.”

Triclosan also remains in certain “antibacterial” products not under the FDA’s control—such as cutting boards and baby products.

In various studies, Gosse and colleagues have made multiple discoveries about TCS. In conducting their research, they’ve used TCS dosages that correspond to doses people are exposed to when brushing their teeth or showering with products that contain the antimicrobial.

One discovery is that TCS is a mitochondrial uncoupler. That is, it’s toxic to mitochondria, which are the energy powerhouses of cells. When mitochondria are deformed or shut down, they can’t make the energy that cells need to perform functions—including immune defense.

One study outside of UMaine found increased TCS levels in mothers of babies with birth defects. Another study, also outside of UMaine, indicated mitochondrial dysfunction was linked to cognitive decline in monkeys.

Gosse determined TCS is 30 to 60 times more toxic than 2,4-dinitrophenol, another uncoupler once used in diet drugs (and to make explosives) that was banned in the late 1930s because it resulted in death or severe side effects.

In UMaine’s most recent study, the team sought to determine the mechanisms underlying TCS disruption of mitochondrial function and mast cell signaling.

To do so, Gosse and her doctoral student Lisa Weatherly teamed with professor of physics Sam Hess and his doctoral student Andrew Nelson.

Hess invented a fluorescence photoactivation localization microscopy (FPALM) technique that allows researchers to witness triclosan’s deformation of live cells’ mitochondria, in real time.

Mitochondria are generally an elongated oval shape. TCS either deforms mitochondria from an oval to a doughnut shape or breaks up the energy powerhouses, within minutes.

Gosse has pored through conference proceedings and publications and believes the UMaine team is the first to use super-resolution microscopy work in the field of toxicology.

Following up on the microscope findings, Gosse and her team determined the biochemical mechanisms that underlie triclosan’s fission of mitochondria—including generation of damaging reactive oxygen species.

TCS, says Gosse, also inhibits cellular cytoskeletons, which are microscopic networks of protein filaments and tubules in the cytoplasm of living cells. Cytoskeletons help the cell move, transport cargo, and carry out many other tasks essential for health.

When TCS inhibits cytoskeletons, it inhibits mast cell function. Mast cells are part of the immune and nervous systems that, when stimulated, release chemicals that play many roles in the body, including antimicrobial defense, cancer and even emotional regulation.

Mast cells are in most human tissues, including the lining of the mouth and in skin—both of which absorb TCS. So, when mast cells are inhibited, problems may arise.

The Gosse lab also found that, of several cell types tested, primary human skin cells were the cells most harmed by TCS.

The UMaine team’s most recent findings were published in April in the article “Antimicrobial agent triclosan disrupts mitochondrial structure, revealed by super-resolution microscopy, and inhibits mast cell signaling via calcium modulation” in Toxicology and Applied Pharmacology.

In addition to Gosse, Hess, Weatherly and Nelson, UMaine researchers participating in the study included graduate students Juyoung Shim and Andrew Hart and undergraduates Erik Gerson and Abigail Riitano; as well as Timothy Ryan and Jaime de Juan-Sanz of Weill Cornell Medicine; and Roger Sher of Stony Brook University.

Funding was provided by an R15 Academic Research Enhancement Award which supports meritorious research and exposes undergraduate and graduate students to hands-on research—from the National Institutes of Health. Graduate School of Biomedical Science and Engineering student Weatherly was supported by UMaine’s Chase Distinguished Research Assistantship and Michael J. Eckardt Dissertation Fellowship.

Thanks to research conducted by Gosse and other scientists, consequences of exposure to triclosan are becoming better understood and known.

And thanks to Hess’ FPALM technique, the field of toxicology has a powerful new tool for understanding chemical effects on human health.

Triclosan, though, is one of about 80,000 synthetic chemicals that people are regularly exposed to, says Gosse. And many of their long-term effects have not been studied.


Explore further:
Common antimicrobial inhibits immune cell function

More information:
Lisa M. Weatherly et al. Antimicrobial agent triclosan disrupts mitochondrial structure, revealed by super-resolution microscopy, and inhibits mast cell signaling via calcium modulation, Toxicology and Applied Pharmacology (2018). DOI: 10.1016/j.taap.2018.04.005

Journal reference:
Toxicology and Applied Pharmacology

Provided by:
University of Maine

Tagged with:

About author

Related Articles