Release of serotonin from mast cells contribute to airway hyperresposivness in asthma
2021-03-12
(Press-News.org) In asthma, the airways become hyperresponsive. Researchers from Uppsala University have found a new mechanism that contributes to, and explains, airway hyperresponsiveness. The results are published in the scientific journal Allergy.
Some 10 per cent of Sweden's population suffer from asthma. In asthmatics, the airways are hyperresponsive (overreactive) to various types of stimuli, such as cold air, physical exertion and chemicals. The airways become constricted, making breathing difficult.
To diagnose asthma, a "methacholine test" is commonly used to determine whether a person is showing signs of airway hyperresponsiveness. Methacholine binds to what are known as muscarinic receptors in the smooth muscle cells lining the inside of the trachea. These muscle cells then begin to contract, causing constriction of the trachea.
In the new study, the scientists show that the airway hyperresponsiveness induced by methacholine is due partly to the body's mast cells. The research was conducted using a mouse model of asthma, where the mice were made allergic to house dust mites.
Mast cells, which are immune cells of a specific type belonging to the innate immune system, are found mainly in tissues that are in contact with the external environment, such as the airways and the skin. Because of their location and the fact that they have numerous different receptors capable of recognising parts of foreign or pathogenic substances, they react quickly and become activated. In their cytoplasm, mast cells have storage capsules, known as granules, in which some substances are stored in their active form. When the mast cell is activated, these substances can be rapidly released and provoke a physiological reaction. This plays a major part in the body's defence against pathogens, but in asthma and other diseases where the body starts reacting against harmless substances in the environment, it becomes a problem.
In their study, the researchers were able to demonstrate that the mast cells contribute to airway hyperresponsiveness by having a receptor that recognises methacholine: muscarinic receptor-3 (M3). When methacholine binds M3, the mast cells release serotonin. This then acts on nerve cells, which in turn control the airways. Thereafter, the airways produce acetylcholine, which also acts on M3 in smooth muscle cells and makes the trachea contract even more. A vicious cycle is under way.
The scientists' discovery also means that drugs like tiotropium, which were previously thought to work solely by blocking M3 in smooth muscle, are probably also efficacious because they prevent activation through M3 in mast cells. Accordingly, the ability of mast cells to rapidly release serotonin in response to various stimuli, thereby contributing to airway hyperresponsiveness, has been underestimated.
INFORMATION:
ELSE PRESS RELEASES FROM THIS DATE:
2021-03-12
The researchers say this is a big step in tackling smouldering peat fires, which are the largest fires on Earth. They ignite very easily, are notoriously difficult to put out, and release up to 100 times more carbon into the atmosphere than flaming fires, contributing to climate change.
The fires, known as 'zombie fires' for their ability to hide and smoulder underground and then reanimate as new flames days or weeks after the wildfire had been extinguished, are prevalent in regions like Southeast Asia, North America, and Siberia.
They are driven by the burning of soils rich in organic content like peat, which is a large natural reservoir of carbon. Worldwide, peat fires account for millions of tonnes of carbon released into the atmosphere each year.
Firefighters currently use millions ...
2021-03-12
A new model of aging takes into account not only genetics and environmental exposures but also the tiny changes that randomly arise at the cellular level.
University Professor Caleb Finch introduced the "Tripartite Phenotype of Aging" as a new conceptual model that addresses why lifespan varies so much, even among human identical twins who share the same genes. Only about 10 to 35 percent of longevity can be traced to genes inherited from our parents, Finch mentioned.
Finch authored the paper introducing the model with one of his former graduate students, Amin Haghani, who received his PhD in the Biology of Aging from the USC ...
2021-03-12
Researchers at Lund University in Sweden can now show that a new examination method identifies high-risk plaques in the blood vessels surrounding the heart, that cannot be seen solely with traditional angiograms. This type of plaque, rich in fat, could potentially cause recurring heart attacks in patients with heart disease. The study is published in the The Lancet.
"We have been working on this study for ten years. This creates a unique opportunity to treat plaques before they cause a heart attack", says David Erlinge, professor of cardiology at Lund University and Consultant in ...
2021-03-12
During 1995-2015, fullerene derivatives had been the dominating electron acceptors in organic solar cells (OSCs) owing to their performance superior to other acceptors. However, the drawbacks of fullerenes, such as weak visible absorption, limited tunability of electronic properties and morphological instability, restrict further development of OSCs toward higher efficiencies and practical applications. Therefore, the development of new acceptors beyond fullerenes is urgent in the field of OSCs.
Professor Zhan Xiaowei from the College of Engineering at Peking University is one of the pioneers engaging in development of nonfullerene acceptors in the world. ...
2021-03-12
University of Otago researchers have discovered one of the reasons why more than 50 per cent of people with type 2 diabetes die from heart disease.
And perhaps more significantly, they have found how to treat it.
Associate Professor Rajesh Katare, of the Department of Physiology, says it has been known that stem cells in the heart of diabetic patients are impaired. While stem cell therapy has proved effective in treating heart disease, it is not the case in diabetic hearts.
It has not been known why; until now.
It comes down to tiny molecules called microRNA which control gene expression.
"Based on the results of laboratory testing, ...
2021-03-12
New bioarchaeological research shows malaria has threatened human communities for more than 7000 years, earlier than when the onset of farming was thought to have sparked its devastating arrival.
Lead author Dr Melandri Vlok from the Department of Anatomy, University of Otago, says this ground-breaking research, published today in Scientific Reports, changes the entire understanding of the relationship humans have had with malaria, still one of the deadliest diseases in the world.
"Until now we've believed malaria became a global threat to humans when we turned to farming, but our research shows in at least Southeast Asia this disease was a threat to human groups well before that.
"This research providing a new cornerstone of malaria's evolution with humans is a great achievement ...
2021-03-12
When people think of sea level rise, they usually think of coastal erosion. However, recent computer modeling studies indicate that coastal wastewater infrastructure, which includes sewer lines and cesspools, is likely to flood with groundwater as sea-level rises.
A new study, published by University of Hawai'i (UH) at Mānoa earth scientists, is the first to provide direct evidence that tidally-driven groundwater inundation of wastewater infrastructure is occurring today in urban Honolulu, Hawai'i. The study shows that higher ocean water levels ...
2021-03-12
Light-emitting diodes (LEDs) have revolutionized the displays industry. LEDs use electric current to produce visible light without the excess heat found in traditional light bulbs, a glow called electroluminescence. This breakthrough led to the eye-popping, high-definition viewing experience we've come to expect from our screens. Now, a group of physicists and chemists have developed a new type of LED that utilizes spintronics without needing a magnetic field, magnetic materials or cryogenic temperatures; a "quantum leap" that could take displays to the next level.
"The companies that make LEDs or TV and computer displays don't want to deal with magnetic fields and magnetic materials. It's heavy ...
2021-03-12
TOKYO - Toshiba Corporation (TOKYO: 6502), the industry leader in solutions for large-scale optimization problems, today announced a scale-out technology that minimizes hardware limitations, an evolution of its optimization computer, the Simulation Bifurcation Machine (SBM), that supports continued increases in computing speed and scale. Toshiba expects the new SBM to be a game changer for real-world problems that require large-scale, high-speed and low-latency, such as simultaneous financial transactions involving large numbers of stock, and complex control of multiple robots. The research results were published in Nature Electronics*1 on March 1.
Speed and scale are keys to success in industrial sectors ...
2021-03-12
Waste cooking oil, sulfur and wool offcuts have been put to good use by green chemists at Flinders University to produce a sustainable new kind of housing insulation material.
The latest environmentally friendly building product from experts at the Flinders Chalker Lab and colleagues at Deakin and Liverpool University, has been described in a new paper published in Chemistry Europe ahead of Global Recycling Day (18 March 2021)
The insulating composite was made from the sustainable building blocks of wool fires, sulfur, and canola oil to produce a promising new model for next-generation insulation - not only capitalising on wool's natural low flammability but also to make significant energy savings for property owners and tenants.
The new composite is one of several exciting ...
LAST 30 PRESS RELEASES:
[Press-News.org] Release of serotonin from mast cells contribute to airway hyperresposivness in asthma
