Inflammation

Posted on Arthritis

New approach against chronic inflammation

Graphics


ASC specks – shown here in different colors – are large complexes of many copies of the ASC protein. They can cause immense damage in the tissue. CREDIT © Franklin Lab / University of Bonn

Not only the villas of the rich and famous have a direct line to the police. The cells in our body also have a sophisticated alarm system, the inflammasome. Its central component is the so-called ASC protein. In the event of danger, such as an attack by a pathogen, many of these molecules join together to form a large complex, the ASC speck. This ensures two things: First, its activity causes the cell to accumulate large quantities of messenger substances, which can be used to summon the help of the immune system. And secondly, numerous pores are formed in the cell membrane through which these alarm molecules can reach the outside and fulfill their task.

Last cry for help from the dying cell

These holes ultimately lead to the demise of the cell: “At some point, the cell basically explodes and empties its entire contents into the tissue,” explains Prof. Dr. Bernardo Franklin of the Institute of Innate Immunity at the University Hospital Bonn. “The messenger substances that are now abruptly released then act like a last great cry for help. This triggers the immune system to mount a strong inflammatory response that contains the infection.” That is why this mechanism of innate immune defense is hugely important.

However, in this process, ASC specks also accumulate in the tissue and may persist there for a long time. “We have now been able to show in mice that their activity activates the immune system even after the threat has been averted,” Franklin says. “This can result in chronic inflammation, which severely damages the tissue.” Together with researchers from the University of Sao Paulo, Franklin’s team has succeeded in preventing this undesirable effect. They used so-called nanobodies for this purpose.

These agents are antibody fragments with a very simple structure. “In collaboration with Prof. Dr. Florian Schmidt from the Institute of Innate Immunity, we generated nanobodies that specifically target ASC and can dissolve the specks,” explains Franklin’s collaborator Dr. Damien Bertheloot. The researchers got help from an alpaca: They injected the animal with the ASC protein so that it developed matching antibodies. Some of the alpaca antibodies have a very simple structure. This makes it possible to produce and test fragments of these antibodies as so-called nanobodies.

Rheumatism and gout symptoms alleviated in mice

The researchers were able to obtain the genetic information for the ASC nanobodies from blood samples of the animal using a complex technique. “We then incorporated this genetic makeup into bacteria so that we could have them produce the nanobody in large quantities,” Bertheloot explains. The team demonstrated that the compound can dissolve ASC specks using human cell cultures as well as mice. “The mice in our experiments have rheumatoid and gout-like symptoms,” Bertheloot explains. “After administration of the nanobody, the inflammation and also the general health of the rodents improved significantly.”

Nanobodies are very small compared to normal antibodies. They are therefore excellent for breaking up such molecular complexes. This is because they can still reach sites that would be too cramped for large agents. Moreover, normal antibodies provide additional stimulation to the immune system and can therefore exacerbate inflammation – a property that nanobodies lack.

The results are also interesting for another reason: Studies indicate that ASC specks can also cause significant damage to the brain. There, they seem to serve as a kind of “crystallization nucleus” for the Aß protein. In the brains of Alzheimer’s patients, Aß clumps together to form large protein complexes called plaques. Presumably, ASC specks can trigger this clumping. “So perhaps it’s possible to slow down this process with the help of our nanobodies,” Franklin hopes. “We now plan to investigate this possibility in a follow-up study.” Bernardo Franklin is a member of the ImmunoSensation2 Cluster of Excellence at the University of Bonn.

At the same time, however, he warns against overly high expectations: Even in the ideal case, it will be years before the results might translate into new drugs.

Posted on Multiple Sclerosis, Rheumatoid arthritis

Large genetic study uncovers potential new treatments for inflammatory diseases

Tie One on for Multiple Sclerosis


Researchers from the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku, Finland, have studied over ten million DNA variations and found new links between the human genome and inflammation tracers. The study uncovered new possibilities for treatment of diseases such as multiple sclerosis, Crohn’s disease and coeliac disease.

Cytokines and growth factors, which circulate in the bloodstream, are important proteins for regulating inflammation reactions. Changes in their mode of operation have been linked with many inflammatory diseases, such as Crohn’s disease, multiple sclerosis, atherosclerosis, ulcerative colitis and many types of cancer.

In this latest study, based on population data and coordinated by the University of Turku’s Research Centre of Applied and Preventive Cardiovascular Medicine, an investigation was made of the links between 41 different cytokines and growth factors and 10.7 million DNA variations.

? We wanted to find out the molecular-level processes that lead to an increased risk of developing inflammatory diseases. Understanding these processes will enable more effective treatment of diseases, explains Professor Olli Raitakari, Director of the Research Centre.

Researchers noticed that the medicine daclizumab, previously used for treating organ rejection reactions, could possibly also be used in the treatment of multiple sclerosis and Crohn’s disease. In addition, an increase in the activity of MIP1b-cytokine could also serve as a method of treatment against coeliac disease and Behcet disease. Further clinical studies are required to confirm the observations.

Evidence from human genetics speeds up medical development

Technological development has enabled the practice of genome-wide association studies since the turn of the century.

? In these kinds of studies, millions of DNA variations are examined and their impact is assessed for each property being studied. The studies carried out so far have succeeded in uncovering, for example, over one hundred genomic loci which have an impact on the risk of developing Crohn’s disease or ulcerous colitis.

In studies of connections between genetic variations and disease risks, the precise molecular process causing the increased risk often remains unclear. In order to uncover this molecular process, genome-wide association studies use as response variables molecules that mediate disease-risk through the bloodstream, such as cytokines and growth factors, instead of using the diseases themselves.

Posted on Patient Talk

Structure of central inflammation switch elucidated

PhD student Inga Hochheiser and Prof. Dr. Matthias Geyer,


director of the Institute of Structural Biology at the University Hospital Bonn (UKB), looking at a cryo-electron microscopy carrier. Photo: Johann F. Saba/UKB

Researchers at the Universities of Bonn and Regensburg have elucidated the structure of a central cellular inflammatory switch. Their work shows which site of the giant protein called NLRP3 inhibitors can bind to. This opens the way to develop new pharmaceuticals that could target inflammatory diseases such as gout, type 2 diabetes or even Alzheimer’s disease. The results are published in the journal Nature. 

In their study, the researchers investigated a protein molecule with the cryptic abbreviation NLRP3. This is a kind of danger sensor in the cell: It sounds the alarm when the cell is under stress, such as from a bacterial infection or toxins.

NLRP3 then induces the formation of pores within the cellular membrane, which ultimately results in the cell’s death. Before that, however, the sensor molecule stimulates the formation of inflammatory messenger substances that are released through the perforated membrane. These so-called cytokines recruit more immune cells to the site and ensure that cells in the surrounding area commit suicide – thereby preventing a bacterium or virus from further spreading.

“The result is a massive inflammatory response,” explains study leader Prof. Dr. Matthias Geyer from the Institute of Structural Biology at the University of Bonn. “This is certainly very useful for the defense against pathogens. But if this response is overdosed or triggered by even harmless cues, it can lead to chronic inflammatory diseases – such as type II diabetes, gout, Crohn’s disease, or even dementias like Alzheimer’s.”

Targeted containment of inflammation

Researchers around the globe are therefore seeking for ways to target inflammatory processes without disrupting the entire mechanism of the immune response. As early as 20 years ago, the US pharmaceutical company Pfizer published an interesting finding in this regard: Certain active substances prevent the release of cytokines, the most important inflammatory messengers. How these CRIDs (Cytokine Release Inhibitory Drugs) do this, however, was unknown until now.

It has been known for several years that CRIDs somehow prevent cellular danger sensors from sounding the alarm. “We have now discovered the way in which they exert this effect,” explains Geyer’s colleague Inga Hochheiser. This involved isolating large amounts of NLRP3 from cells, purifying it, and adding the inhibitor CRID3. Hochheiser dropped minute portions of this mixture onto a carrier and then froze them rapidly.

This method creates a thin film of ice containing millions of NLRP3 molecules to which CRID3 is bound. These can be observed with an electron microscope. Since the molecules fall differently as they drop, different sides of them can be seen under the microscope. “These views can be combined to create a three-dimensional image,” Hochheiser explains.

The cryo-EM images allow a detailed insight into the structure of the hazard sensor inactivated by CRID3. They reveal that NLRP3 in its inactive form assembles into a mega-molecule. It consists of ten NLRP3 units that together form a kind of cage. “The most exciting result of our work, however, is that we were able to identify the CRID3 molecule docked into its binding site,” Geyer is pleased to report. “That was a tough nut that many groups worldwide have been trying to crack.”

Inhibitor prevents the activation of the giant molecule

The binding sites (structural biologists also speak of “pockets”) are located inside the cage. Each of the ten NLRP3 units has one of these pockets. When occupied by CRID3, the inhibitor blocks a flap mechanism required for NLRP3 activation. Similar to a blooming rose, which can only be visited by a bee in this state, certain parts of the NLRP3 protein reach the surface of the cage when the flap is turned over and thus become accessible.

NLRP3 is a representative of an entire family of similar proteins. Each of them presumably performs its very specific task in different inflammatory processes. “Based on our research, we believe that the pockets of all these NLRPs are different,” Geyer says. “A specific inhibitor can therefore probably be found for each of them.” This gives researchers a whole arsenal of potential new weapons against diverse, inflammatory diseases.

For example, the current work allows a targeted search for more effective alternatives to CRID3 that also have fewer side effects. But that is just the beginning, says Geyer, who is also a member of the ImmunoSensation2 Cluster of Excellence at the University of Bonn. “I am convinced that our study opens up a fruitful new field of research that will keep researchers busy for decades to come.”

Posted on Pain Management

Scientists reveal mechanism for colon pain and inflammation

PAR2 in normal and inflamed tissue


In normal tissue, PAR2—seen here in fluorescent green—is found on the surface of cells, but in inflamed tissue, it moves from the surface of cells to compartments within cells called endosomes. CREDIT Bunnett Lab, NYU Dentistry

Researchers at the NYU Pain Research Center have identified a mechanism that underlies inflammation and pain in the colon, and demonstrated that blocking a key receptor from entering colon cells can inhibit inflammation and pain, uncovering a potential target for treating pain in inflammatory bowel disease. 

Their study, published in the Proceedings of the National Academy of Sciences (PNAS), was conducted in mice with colitis, an inflammatory disease marked by chronic and sometimes painful inflammation of the large intestine.

The digestive tract is home to a large number of proteases, or enzymes that break down proteins. These proteases come from a variety of sources, including the microbiota, inflammatory cells, or digestive enzymes in the intestine.

While proteases are important for digestion and help to degrade proteins in the gut, many also signal cells by activating specific G protein-coupled receptors (GCPRs). GCPRs are a large family of receptors that regulate many processes in the body and are the target of one third of clinically used drugs. When proteases activate one such GCPR—protease-activated receptor-2, or PAR2—on nerve cells, it causes the release of mediators that produce pain.

Studies show that protease activation of PAR2 is involved in gastrointestinal diseases that can be associated with pain, including inflammatory bowel disease, irritable bowel syndrome, and cancer. But until now, scientists have not fully understood the receptor’s signaling mechanism and how it induces pain.

To pinpoint PAR2’s location in the gut, the researchers created a mouse model in which the gene for PAR2 is fused to a green fluorescent protein. When a cell expresses PAR2, it lights up green, allowing the researchers to precisely see where the receptor is positioned. They found that PAR2 was very highly expressed on the surface or membrane of the epithelial cells that line the small and large intestines, and to a lesser extent in nerve fibers in these areas.

The researchers then discovered a key difference in the location and behavior of PAR2 in healthy mice versus mice with colitis. In healthy mice, PAR2 was found on the membrane of colonic epithelial cells, but in mice with colitis, it shifted from the surface of cells to compartments within cells called endosomes. When the receptor moved into endosomes, it generated signals that cause inflammation and pain by disrupting the normal protective function of cells lining the colon. 

“We identified not only where this receptor is in the digestive tract, but also how it signals inflammation and pain in the colon,” said Nigel Bunnett, PhD, professor and chair of the Department of Molecular Pathobiology at NYU College of Dentistry and the study’s senior author. “This more complete understanding of PAR2 and its signaling mechanism could ultimately help us to better treat inflammatory and painful diseases of the colon.”

Additional studies using human colon tissue confirmed that activating PAR2 induces inflammation in the colon.

If PAR2 moving from the surface of cells into endosomes leads to inflammation and pain, could blocking the receptor from entering cells limit inflammation and pain? To test this idea, the researchers prevented the movement of PAR2 into cells by knocking down the expression of a protein called dynamin-2. Keeping the receptor out of cells did, in fact, inhibit signaling and significantly reduced pain and inflammation.

The findings suggest that PAR2—and specifically, PAR2 in endosomes—may be a useful target in treating pain in inflammatory bowel disease.

“This could be achieved through blocking PAR2 from entering cells, as we did in this study by inhibiting dynamin-2,” said Bunnett. “It could also mean getting drugs that activate PAR2 not just to the surface of cells, but into the interior of cells using nanoparticles to reach the receptorin endosomes.”

Posted on Arthritis

Please read if you have pain and/or inflammation- Turmeric (Curcumin) | New Research Is Game Changing!

Turmeric (Curcumin) | New Research Is Game Changing! - YouTube


Curcumin, which is the active ingredient from turmeric, has been used for 1000s of years and is heralded as a powerful anti-oxidant and anti-inflammatory. So what do the human clinical trials show? The data has convinced me to consider using curcumin for patients with osteoarthritis.