Protein-rich diet may help soothe inflamed gut

Immune cells patrol the gut to ensure that harmful microbes hidden in the food we eat don't sneak into the body. Cells that are capable of triggering inflammation are balanced by cells that promote tolerance, protecting the body without damaging sensitive tissues. When the balance tilts too far toward inflammation, inflammatory bowel disease can result.

Now, researchers at Washington University School of Medicine in St. Louis have found that a kind of tolerance-promoting immune cell appears in mice that carry a specific bacterium in their guts. Further, the bacterium needs tryptophan - one of the building blocks of proteins - to trigger the cells' appearance.

"We established a link between one bacterial species - Lactobacillus reuteri - that is a normal part of the gut microbiome, and the development of a population of cells that promote tolerance," said Marco Colonna, MD, the Robert Rock Belliveau MD Professor of Pathology and the study's senior author. "The more tryptophan the mice had in their diet, the more of these immune cells they had."

If such findings hold true for people, it would suggest that the combination of L. reuteri and a tryptophan-rich diet may foster a more tolerant, less inflammatory gut environment, which could mean relief for the million or more Americans living with the abdominal pain and diarrhea of inflammatory bowel disease.

A representation of the 3D structure of the protein myoglobin showing turquoise α-helices. By AzaToth (self made based on PDB entry) [Public domain], via Wikimedia Commons

Postdoctoral researcher Luisa Cervantes-Barragan, PhD, was studying a kind of immune cell that promotes tolerance when she discovered that one group of study mice had such cells, while a second group of study mice that were the same strain of mice but were housed far apart from the first group did not have such cells.

The mice were genetically identical but had been born and raised separately, indicating that an environmental factor influenced whether the immune cells developed.

She suspected the difference had to do with the mice's gut microbiomes - the community of bacteria, viruses and fungi that normally live within the gastrointestinal tract.

Cervantes-Barragan collaborated with Chyi-Song Hsieh, MD, PhD, the Alan A. and Edith L. Wolff Distinguished Professor of Medicine, to sequence DNA from the intestines of the two groups of mice. They found six bacterial species present in the mice with the immune cells but absent from the mice without them.

With the help of Jeffrey I. Gordon, MD, the Dr. Robert J. Glaser Distinguished University Professor, the researchers turned to mice that had lived under sterile conditions since birth to identify which of the six species was involved in inducing the immune cells. Such mice lack a gut microbiome and do not develop this kind of immune cell. When L. reuteri was introduced to the germ-free mice, the immune cells arose.

To understand how the bacteria affected the immune system, the researchers grew L. reuteri in liquid and then transferred small amounts of the liquid - without bacteria - to immature immune cells isolated from mice. The immune cells developed into the tolerance-promoting cells. When the active component was purified from the liquid, it turned out to be a byproduct of tryptophan metabolism known as indole-3-lactic acid.

Tryptophan - commonly associated with turkey - is a normal part of the mouse and the human diet. Protein-rich foods contain appreciable amounts: nuts, eggs, seeds, beans, poultry, yogurt, cheese, even chocolate.

When the researchers doubled the amount of tryptophan in the mice's feed, the number of such cells rose by about 50 percent. When tryptophan levels were halved, the number of cells dropped by half.

People have the same tolerance-promoting cells as mice, and most of us shelter L. reuteri in our gastrointestinal tracts. It is not known whether tryptophan byproducts from L. reuteri induce the cells to develop in people as they do in mice, but defects in genes related to tryptophan have been found in people with inflammatory bowel disease.

"The development of these cells is probably something we want to encourage since these cells control inflammation on the inner surface of the intestines," Cervantes-Barragan said. "Potentially, high levels of tryptophan in the presence of L. reuteri may induce expansion of this population."

For more information visit:-

https://www.sciencedaily.com/releases/2017/08/170803141045.htm

https://en.wikipedia.org/wiki/Protein

http://www.prlabs.co.uk/lab-supplies.php?N=300l-msia-darts-protein-a&Id=19590

Simple fats, amino acids to explain how life began

Life is a process that originated 3.5 billion years ago. It emerged when the basic components of the cells that we know today, in other words, inanimate chemical molecules, gradually joined, merged, assembled themselves and interacted. At a given moment they became alive, or what amounts to the same thing, they turned into autonomous systems. As the years passed they gradually evolved until achieving their current complexity and diversity. A piece of research by the UPV/EHU is working on the start of this trajectory by studying how the chemical molecules assembled themselves so that life could begin.

A section of DNA. Zephyris at the English language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

DNA, RNA, proteins, membranes, sugars, …cells are made up of all kinds of components. In biology, and in the studies dealing with the origin of life specifically, it is very common to focus on one of these molecules and put forward hypotheses on how life originated by analysing the specific mechanisms related to it. "Basically, these studies are looking for the 'molecule of life', in other words, they set out to establish which was the most important molecule in making this milestone happen," said Kepa Ruiz-Mirazo, researcher in the Biophysics Unit and of the UPV/EHU's Department of Logic and Philosophy of Science. However, bearing in mind that "life involves activity among a huge variety of molecules and components, a change of approach has been taking place in recent years and research that takes into account various molecules at the same time is gaining strength," he added.

Besides emerging in favour of this fresh approach, Ruiz-Mirazo's group, in collaboration with the University of Montpellier, through an internship of the UPV/EHU PhD student Sara Murillo-Sánchez, has been able to show that interaction exists between some molecules and others. "Our group has expertise in research into membranes that are created in prebiotic environments, in other words, in the study of the dynamics that fatty acids, the precursors of current lipids, may have had. 

The Montpellier group for its part specialises in the synthesis of the first peptides. So when the knowledge of each group is put together, and when we experimentally blended the fatty acids and the amino acids, we could see that there was a strong synergy between them."

As they were able to see, the catalysis of the reaction took place when the fatty acids formed compartments. As they are in an aqueous medium, and due to the hydrophobic nature of lipids, they tend to join with each other and form closed compartments; in other words, they take on the function of a membrane; "at that time the membranes obviously weren't biological but chemical ones," explained Ruiz-Mirazo. In their experiments they were able to see that the conditions offered by these membranes are favourable for amino acids. "The Montpellier group had the prebiotic reactions of the formation of dipeptides very well characterised, so they were able to see that this reaction took place more efficiently in the presence of fatty acids," he added.

Besides demonstrating the synergy between fatty acids and amino acids, Ruiz-Mirazo believes it is very important to have conducted the study using basic chemical components, in other words, molecular precursors. "Life emerged out of these basic molecules; therefore, to study its origin we cannot start from the complex phospholipids that are found in today's membranes. We have demonstrated the formation of the first coming together and formation of chains on the basis of molecular precursors. Or to put it another way, we have demonstrated that it is possible to achieve diversity and complexity in biology by starting from chemistry."

In his studies, in addition to the experimental work, Ruiz-Mirazo is working in another two spheres so in the end he is studying the origin of life from three pillars or perspectives: "firstly, we have the experimental field; another is based on theoretical models and computational simulations, which we use to analyse the results obtained in the experiments, and the third is a little broader, because we are studying from the philosophical viewpoint what life is, the influence that the conception held about life exerts on the experimental field, since each conception leads you to carry out a specific type of experiment," he explained. "These three methodologies mutually feed each other: an idea that may emerge in the philosophical analysis leads you to carry out a new simulation, and the results of the simulations mark out the path for designing the experiments. Or the other way round. Most likely we will never manage to find the answer to how life began, but we are working on it: all of us living beings on Earth have the same origin and we want to know how it happened."

For more information visit:-

https://www.sciencedaily.com/releases/2017/01/170112083719.htm

http://www.prlabs.co.uk/lab-supplies.php?N=300l-msia-darts-protein-ag&Id=19593

Tiny protein 'compasses' found in fruit flies - and potentially humans

Tiny biological compasses made from clumps of protein may help scores of animals, and potentially even humans, to find their way around, researchers say.

Scientists discovered the minuscule magnetic field sensors in fruit flies, but found that the same protein structures appeared in retinal cells in pigeons’ eyes. They can also form in butterfly, rat, whale and human cells.

The rod-like compasses align themselves with Earth’s geomagnetic field lines, leading researchers to propose that when they move, they act on neighbouring cell structures that feed information into the nervous system to create a broader direction-sensing system.

Professor Can Xie, who led the work at Peking University, said the compass might serve as a “universal mechanism for animal magnetoreception,” referring to the ability of a range of animals from butterflies and lobsters to bats and birds, to navigate with help from Earth’s magnetic field.

Whether the compasses have any bearing on human navigation is unknown, but the Peking team is investigating the possibility. “Human sense of direction is complicated,” said Xie. “However, I believe that magnetic sense plays a key role in explaining why some people have a good sense of direction.”

The idea that animals could sense Earth’s magnetic field was once widely dismissed, but the ability is now well established, at least among some species. The greatest mystery that remains is how the sensing is done.

One type of molecular compass, proposed by the biologist Klaus Schulten, senses geomagnetic field information through the bizarre quantum behaviour of electrons that are produced when light falls on retinal proteins called cryptochromes. But Xie argues that a compass based on cryptochromes alone is not enough to navigate.

By screening the fruit fly genome, the Chinese team discovered a protein they named MagR, which forms rod-like clumps with cryptochrome proteins. This MagR-cryptochrome cluster behaves like a sophisticated magnetic sensor that in principle can sense the direction, intensity or inclination of Earth’s magnetic field.

“The nanoscale biocompass has the tendency to align itself along geomagnetic field lines and to obtain navigation cues from a geomagnetic field,” said Xie. “We propose that any disturbance in this alignment may be captured by connected cellular machinery, which would channel information to the downstream neural system, forming the animal’s magnetic sense.”

In a series of follow-up experiments, the scientists show that MagR-cryptochrome compass can form in a range of species, including monarch butterflies, pigeons, more rats, minke whales and humans. Details are reported in the journal Nature Materials.

Xie said the discovery could go beyond understanding how animals navigate, and lead to new technologies that allow scientists to control cell processes and influence animal behaviour with magnetic fields.

Simon Benjamin, who studies quantum materials at Oxford University, said that evolution seemed to have found a number of ways to sense magnetic fields. “It seems plausible that the structure discovered in this paper is key to the fruit fly’s compass, and perhaps other species as well.”

He added that the finding was exciting even if the MagR-cryptochrome cluster was not one of nature’s biocompasses, because it could be used to develop new technologies. “There is a continual drive for cheaper, smaller, more robust, or more sensitive field sensors. They’re needed to enable a vast range of applications from mining survey systems to map navigation with mobile phones.”

“It has been well documented that cryptochromes, which are crucial to the compass proposed in this new paper, may harness significant quantum effects to convert the Earth’s weak magnetic field into a signal in the animal’s brain. 

This is a tantalising possibility since the new UK quantum technology hubs are focusing about a quarter of their £150M on sensor systems. It would be remarkable if we can learn some tricks from Mother Nature in this highly-advanced field of physics,” he added.

For more information visit:-

http://www.theguardian.com/science/2015/nov/16/tiny-protein-compasses-found-in-fruit-flies-and-potentially-humans

http://www.prlabs.co.uk/lab-supplies.php?N=protein-a-ceramic-hyperd-f&Id=44559

Stain Removal - How Does it Work?

We’ve all struggled to get stains out of clothes – but do you understand the science behind this? Most stains are removed by dissolving them with a solvent. But which one do you use? Two factors should help you to decide this:

• The agent that is causing the stain
• The material that has been stained

Different solvents will dissolve different stains, however some solvents not only dissolve the stain, but also dissolve the material that is stained as well – something that you don’t want to happen! 

Click to enlarge

Stains can be roughly grouped into a few categories:

Enzymatic stains, such as blood, human sweat and grass stains, are mainly made up of proteins and can therefore be combatted by enzymes in stain remover formulations, such as proteases, lipases and amylases.

Oxidisable stains, like tea, coffee and red wine, which can be broken down by bleaching agents, like hydrogen peroxide.

Greasy stains, which can be attacked by lipase enzymes and surfactants. Compound Chemicals describes these as most commonly being "‘long carbon chain compounds with a charged water-soluble ‘head’ and an oil-soluble ‘tail’ (which) remove oil and grease by forming structures called ‘micelles’ around them.”

Particulate stains, such as soil stains, can be removed by ‘builders’ compounds, which remove positive metal ions from the water and help soften it, in turn removing calcium ions which often bind stains to fabrics.

So, next time you regret that wine spillage or try to take that grass stain out of a football shirt, you’ll know what’s going on behind that brightly coloured stain remover – the science of stains! 

For more information visit:-

http://www.prlabs.co.uk/lab-supplies.php?N=hydrogen-peroxide-6-wv-gpr-rectapur&Id=59163

http://www.compoundchem.com/2015/06/18/stain-removal/

https://en.wikipedia.org/wiki/Stain_removal

http://www.prlabs.co.uk/lab-supplies.php?N=ob-protease-solution&Id=62099