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Scientists have created a new treatment for traumatic brain injury (TBI) that shrank brain lesions by 56% and significantly reduced local inflammation levels in pigs. The new approach leverages macrophages, a type of white blood cell that can dial inflammation up or down in the body in response to infection and injury. The team created disc-shaped microparticles called “backpacks” containing anti-inflammatory molecules, then attached them directly to the macrophages. These molecules kept the cells in an anti-inflammatory state when they arrived at the injury site in the brain, enabling them to reduce local inflammation and mitigate the damage caused. The research is reported in PNAS Nexus.
“Every year, millions of people suffer from a TBI, but there is currently no treatment beyond managing symptoms. We have applied our cellular backpack technology — which we previously used to improve macrophages’ inflammatory response to cancerous tumors — to deliver localized anti-inflammatory treatment in the brain, which helps mitigate the cascade of runaway inflammation that causes tissue damage and death in a human-relevant model,” said senior author Samir Mitragotri, Ph.D., in whose lab the research was performed. Mitragotri is a Core Faculty member of the Wyss Institute at Harvard University and the Hiller Professor of Bioengineering and Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS).
Stopping a runaway inflammation train
More than a million people in the US suffer from a traumatic brain injury (TBI) every year, about 230,000 of them are hospitalized, and almost 70,000 die from TBI-related causes. There is currently no treatment for the damage caused to brain tissue during a TBI, beyond managing a patient’s symptoms. One of the main drivers of TBI-caused damage is a runaway inflammatory cascade in the brain.
As cells die from the impact, they release a cocktail of pro-inflammatory cytokine molecules that attract immune cells to clean up the damage. But the same cytokine molecules can also disrupt the blood-brain barrier, which causes blood to leak into the brain. Blood accumulation in the brain causes swelling, impaired oxygen delivery, and increased inflammation, and creates a vicious cycle of bleeding and damage that drives even more cell death.
The Mitragotri lab saw an opportunity in this problem.
“It’s generally believed anti-inflammatory therapies can be effective for treating TBI, but so far, none of them have proven effective clinically. Our previous work with macrophages has shown us that we can use our backpack technology to effectively steer their behavior when they arrive at the injury site. Since these cells are already active players in the body’s natural immune response to a TBI, we had a hunch we could augment that preexisting biology to reduce the initial damage,” said co-first author Rick Liao, Ph.D., a Postdoctoral Fellow at the Wyss Institute and SEAS.

“Body, heal thyself”…with backpacks
Macrophages are very malleable cells and can “switch” between pro-inflammatory and anti-inflammatory states. While the team’s previous work in cancer had been focused on keeping macrophages in a pro-inflammatory state when they arrive at the inflammation-reducing microenvironment of a tumor, this new project would be trying to do the opposite: keep the macrophages “calm” in the inflammation-riddled setting of a brain injury.
To do so, they used a disc-shaped “backpack” they had previously designed to treat multiple sclerosis that contained layers of two anti-inflammatory molecules: dexamethasone, a steroid, and interleukin-4, a cytokine that encourages macrophages to adopt an anti-inflammatory state. They then incubated these microparticles with both human and pig macrophages in vitro and saw that the backpacks stably stuck to the cells without causing any negative effect. They also observed that application of their backpacks decreased the expression of pro-inflammatory biomarkers and increased the expression of anti-inflammatory biomarkers, retaining the pig macrophages in a healing state.
But to prove that this shift would work in the body, they had to test the backpack-bearing macrophages in vivo. They chose pigs as their model organism because their brains’ structures and responses to injury more closely mimic those of humans than mice.
“Probably our biggest challenge in this project was scaling up production to match what we needed to run the experiments. Our previous studies were done in rodents, which required about two million macrophages and four million backpacks administered per subject. For the porcine study, we needed 100 million macrophages and 200 million backpacks per subject — on the scale of what would be administered in humans — and lots of helping hands,” said co-first author Neha Kapate, Ph.D., a Postdoctoral Fellow at the Wyss Institute and SEAS. The final team consisted of over 20 members from across the Wyss Institute, Harvard, MIT, and Mass General Hospital (MGH).
Once they had generated enough backpack-wearing porcine macrophages, they infused them into the pigs’ bloodstreams four hours after a TBI. Seven days later, they analyzed the animals’ brains. Pigs that had received the macrophage treatment showed a high concentration of the cells in the area immediately surrounding the injury site, their lesions were 56% smaller, and there was significantly less hemorrhaging than in untreated animals.

Local immune cells also displayed a lower amount of a pro-inflammatory activation marker called CD80, indicating that the macrophages had accomplished their damage control by reducing inflammation in the brain. Corroborating that data, the levels of two soluble biomarkers for inflammation in the blood and cerebrospinal fluid were lower in treated animals than in untreated animals. The macrophage treatment also did not cause any negative effects.
The team plans to conduct future studies that focus on elucidating exactly how their anti-inflammatory macrophage therapy affects the blood-brain barrier’s integrity to prevent bleeding, which could also hold promise for treating other conditions like hemorrhagic strokes.
“Macrophages’ susceptibility to their local environment has historically prevented scientists from taking full advantage of their immune-modulating capabilities. This impressive study describes a truly novel and potentially powerful macrophage-based therapy for treating the inflammation that is the root cause of so many human afflictions in an effective and non-invasive way that works with biology rather than against it,” said Wyss Founding Director Donald Ingber, M.D., Ph.D. Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, and the Hansjörg Wyss Professor of Bioinspired Engineering at SEAS.
Additional authors of the study include Luke Sodemann, Tawny Stinson, Bryan Golemb, Alexander Hone, and Andrea Slate from MGH; Supriya Prakash, Ninad Kumbhojkar, Vineeth Chandran Suja, Suyog Shaha, Kyung Soo Park, Michael Dunne, and Kolade Adebowale from the Wyss Institute and SEAS; Lily Li-Wen Wang and Morgan James from the Wyss Institute, Harvard SEAS, and MIT; Mikayla Flanz, Rohan Rajeev, Dania Villafuerte, and John Clegg from Harvard SEAS; Declan McGuone from Yale School of Medicine, and Beth Costine-Bartell from MGH and Harvard Medical School.
This research was supported by the US Department of Defense under Grant No. W81XWH-19-2-0011, the National Science Foundation Graduate Research Fellowship under Grant Nos. 1122374 and 1745302, National Institute of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development under Grant No. R01 HD099397, the Wyss Institute at Harvard University, and Harvard SEAS.

For over 40 years, he and his organization, the Health Research Group, held government and manufacturers to account for unsafe medication.Sidney M. Wolfe, a physician and consumer advocate who for more than 40 years hounded the pharmaceutical industry and the Food and Drug Administration over high prices, dangerous side effects and overlooked health hazards, bringing a new level of transparency and accountability to the world of medical care, died on Monday at his home in Washington. He was 86.His wife, Suzanne Goldberg, said the cause was a brain tumor.Along with the consumer advocate Ralph Nader, Dr. Wolfe founded the Health Research Group in 1971, and over the next four decades used it as a base for his relentless campaigns on behalf of health care users. At the door to his office, on the seventh floor of a dingy building near Dupont Circle in Washington, he hung a sign that read “Populus iamdudum defutatus est” — Latin for, roughly, “The people have been screwed long enough.”His strategy, built around what he called “research-based advocacy,” was to flood the zone with information: news releases, congressional testimonies and interviews in the news media. A visitor to his office would invariably come away with a stack of reports recently issued by the Health Research Group.Dr. Wolfe’s first effort, a few months before officially founding the group, was to write a letter with Mr. Nader to the F.D.A. about contamination in bags of intravenous fluid manufactured by Abbott Laboratories — and then to release the letter to the news media. Within two days, some two million bags had been recalled.Dr. Wolfe, partly obscured at center, appeared with his fellow consumer advocate Ralph Nader, right, in a news conference in Philadelphia in 1971. They were joined by Anthony Mazzocchi, a labor leader.Associated PressThe IV case “led me to think that there were an awful lot of problems that had been well documented, but no one had done anything about them,” he told The Washington Post in 1989.Soon after their success with Abbott, Dr. Wolfe and Mr. Nader found themselves flooded with tips and leaks from doctors and researchers in the government and industry. In response they created the Health Research Group, an offshoot of Mr. Nader’s organization, Public Citizen.Over his long tenure at the group Dr. Wolfe managed to get more than a dozen drugs removed from the market, and warning labels affixed to dozens of others. He took on more than just drugs — among his targets were contact lenses, pacemakers, tampons, cigarettes and toothpaste, anything that might touch on health and health care.He wrote a monthly newsletter in which he included a regular column called “Outrage of the Month.” In 1980, he self-published a book, “Worst Pills, Best Pills: A Consumer’s Guide to Avoiding Drug-Induced Death or Illness.” It became a New York Times best seller and has sold more than 2.2 million copies over multiple editions.His critics — and they were legion — called Dr. Wolfe a “gadfly” and a “zealot,” and even his admirers acknowledged that he could be demanding and impatient. For his 75th birthday, one of his daughters and a son-in-law gave him a doll, made to look like him, with a button that when pressed said, “It’s an outrage!”He laughed off the jabs, but also insisted that he took a more measured approach than his critics said. He did not go after emergency or lifesaving drugs, like those aimed at cancer or AIDS, he said, because he felt their benefits outweighed virtually any side effect. He also pointed out that most of what he published was not outrage but information — for example, a regular series in his newsletter about how to read a drug label.But he never apologized for taking a tough stand against the health care industry.“Somebody has to look out for people who are being manipulated by the hospitals, doctors, insurance and drug companies,” he told The Progressive magazine in 1993.Sidney Manuel Wolfe was born on June 12, 1937, in Cleveland, the son of Fred and Sophia (Marks) Wolfe. His mother was an English teacher, his father an inspector for the U.S. Labor Department.His first career aspiration was chemical engineering, which he studied at Cornell University. But he decided to find a new path after spending a summer working in a factory that made hydrofluoric acid, where regular contact with chemicals meant that “every day I’d go home with first-degree burns,” he told The Washington Post in 1978.He transferred to Western Reserve University (today Case Western Reserve University), from which he graduated in 1959, and continued on into medical school. There he studied under Dr. Benjamin Spock, the pediatrician and peace activist, and spent time working with drug-overdose cases — two experiences that would shape his career.Dr. Wolfe in an undated photo. His consumer advocacy organization, the Health Research Group, was an offshoot of Mr. Nader’s organization Public Citizen.Beverly Orr/Public CitizenAfter receiving his medical degree in 1965, Dr. Wolfe served in the Public Health Service, then moved to the National Institutes of Health, where he researched addiction. He also worked with the Medical Committee for Human Rights, a group of health care professionals active in the civil rights movement.Late one night he called a friend and fellow doctor to ask him to provide care for a sick woman associated with the Black Panthers.“He said, ‘Get your ass out of bed,’” recalled the doctor, Anthony Fauci, later the head of the National Institute of Allergy and Infectious Diseases, in a 1992 interview with The Wall Street Journal. “That’s vintage Sid.”Dr. Wolfe’s first marriage, to Ava Albert, ended in divorce. He married Dr. Goldberg, a psychologist and artist, in 1978. Along with her, he is survived by four children from his first marriage, Hannah, Leah, Rachel and Sarah Wolfe; two stepsons, Nadav and Stefan Savio; five grandchildren; and his sister, Janet, also a psychologist.Dr. Wolfe received a MacArthur Fellowship, also known as a “genius grant,” in 1990. From 2008 to 2012 he served on the Drug Safety and Risk Management Advisory Committee, a part of the F.D.A. He retired from running the Health Research Group in 2013.He remained active at Public Citizen, though he insisted that he had significantly cut back his time commitment, from 60 or more hours a week to a mere 40 to 45.

The Minnesota woman said the dental work, performed in one day in July 2020, caused her “pain and suffering, embarrassment, emotional distress and disfigurement.”A Minnesota woman who said that she received four root canals, eight dental crowns and 20 fillings in a single visit to a dentist’s office has sued him for negligence, claiming that he caused her disfigurement.The patient, Kathleen Wilson, of Hennepin County, Minn., filed the lawsuit on Dec. 21 in District Court against Dr. Kevin Molldrem of Molldrem Family Dentistry in Eden Prairie, Minn., over the July 2020 visit that she said caused her significant injuries.Ms. Wilson said in the legal complaint that she lost income because of the dental work and that she had endured “pain and suffering, embarrassment, emotional distress and disfigurement” as a result. It is not clear from the lawsuit what Ms. Wilson’s occupation is.A lawyer for Ms. Wilson did not respond to an inquiry for further comment. Dr. Molldrem, who is listed as representing himself in the case, according to the complaint, did not respond to a request for comment.On his website, Dr. Molldrem said he opened his practice in Eden Prairie, Minn., “to provide the type of dental care for others as I would want for my own family.”According to the suit, Ms. Wilson received dental care from Dr. Molldrem from July 7 to July 21, 2020.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? 

An atomic-level investigation of how Eastern equine encephalitis virus binds to a key receptor and gets inside of cells also has enabled the discovery of a decoy molecule that protects against the potentially deadly brain infection, in mice.
The study, from researchers at Washington University School of Medicine in St. Louis, is published Jan. 3 in the journal Cell. By advancing understanding of the complex molecular interactions between viral proteins and their receptors on animal cells, the findings lay a foundation for treatments and vaccines for viral infections.
“Understanding how viruses engage with the cells they infect is a critical part of preventing and treating viral disease,” said co-senior author Michael S. Diamond, MD, PhD, the Herbert S. Gasser Professor at Washington University. “Once you understand that, you have the foundation for developing vaccines and drugs to block it. In this study, it took us a long time to sort out the complexity associated with the particular receptor-virus interaction, but once we acquired this knowledge, we were able to design a decoy molecule that turned out to be very effective at neutralizing the virus and protecting mice from disease.”
Though infections of Eastern equine encephalitis virus in people are rare — with only a few cases reported worldwide each year — about one-third of those with the infection die, and many survivors suffer lasting neurological problems. Further, scientists predict that as the planet warms and climate change lengthens mosquito populations’ seasons and geographical reach, risk of infection will grow. At present, there are no approved vaccines against the virus or specific medications to treat it.
As a first step to finding ways to treat or prevent the deadly virus, Diamond and co-senior author Daved H. Fremont, PhD, a professor of pathology & immunology, set about investigating how the virus attaches to one of its key receptors — a molecule called VLDLR, or very low density lipoprotein receptor. The molecule is found on the surface of cells in the brain and other parts of the body. Co-first author Lucas Adams, an MD/PhD student in the Fremont and Diamond laboratories, used cryo-electron microscopy to reconstruct the virus binding to the receptor in atomic-level detail.
The results turned out to be unexpectedly complex. The molecule is composed of eight repeated segments, called domains, strung together like beads on a chain. Usually, a viral protein and its receptor fit together in one very specific way. In this case, however, two or three different spots on the viral surface proteins were capable of attaching to any of five of the molecule’s eight domains.
“What’s really striking is that we find multiple binding sites, but the chemistry of each of the binding sites is very similar and also similar to the chemistry of binding sites for other viruses that interact with related receptors,” said Fremont, who is also a professor of biochemistry & molecular biophysics and of molecular microbiology. “The chemistry just works out well for the way viruses want to attach to cell membranes.”
The domains that make up this molecule also are found in several related cell-surface proteins. Similar domains are found in proteins from across the animal kingdom.

“Since they’re using a molecule that naturally has repetitive domains, some of the alphaviruses have evolved to use the same strategy of attachment with multiple different domains in the same receptor,” said Diamond, who is also a professor of medicine, of molecular microbiology, and of pathology & immunology. Alphaviruses include Eastern equine encephalitis virus and several other viruses that cause brain or joint disease. “There are sequence differences in the VLDLR receptor over evolution in different species, but since the virus has this flexibility in binding, it is able to infect a wide variety of species including mosquitoes, birds, rodents and humans.”
To block attachment, the researchers created a panel of decoy receptors by combining subsets of the eight domains. The idea was that the virus mistakenly would bind to the decoy instead of the receptor on cells, and the decoy with the virus attached could then be cleared away by immune cells.
Co-first author Saravanan Raju, MD, PhD, a postdoctoral researcher in the Diamond lab, evaluated the panel of decoys. First, he tested them on cells in dishes. Many neutralized the virus. Then, he turned to mice. Raju pretreated mice with a decoy or saline solution, as a control, six hours before injecting the virus under their skin, a mode of infection that mimics natural infection via mosquito bite. Three decoys were tested: one known to be unable to neutralize the virus; one made from the full-length molecule; and one made from just the first two domains.
All of the mice that received saline solution, the non-neutralizing decoy or the full-length decoy died within eight days of infection. All of the mice that received the decoy made from the first two domains survived without signs of illness.
Certain aspects of its biology give Eastern equine encephalitis virus the potential to be weaponized, making it particularly important to find a way to protect against it. In a subsequent experiment in which the mice were infected by inhalation — as would happen if the virus were aerosolized and used as a bioweapon — the decoy made from the first two domains was still effective, reducing the mice’s chance of death by 70%.
“Through a combination of the structural work and the domain deletion work, we were able to figure out which domains are the most critical and create a quite effective decoy receptor that can neutralize viral infection,” Fremont said. “This study broadens what we know about virus-receptor interactions and could lead to new approaches to preventing viral infections.”

A new study from researchers at the University of Colorado Anschutz Medical Campus finds that older adult drivers who are recently diagnosed with migraines are three times as likely to experience a motor vehicle crash. Older adult drivers who reported having ever had migraines in the past were no more likely to have a motor vehicle crash than those without migraines.
Additionally, study results, published in the Journal of the American Geriatrics Society, explored the relationships medications commonly prescribed for migraine management have with increased crash risk.
“Migraine headaches affect more than 7% of U.S. adults over the age of 60,” says Carolyn DiGuiseppi, MPH, PhD, MD, professor with the Colorado School of Public Health and study lead author. “The US population is aging, which means increasing numbers of older adult drivers could see their driving abilities affected by migraine symptoms previously not experienced. These symptoms include sleepiness, decreased concentration, dizziness, debilitating head pain and more.”
Researchers conducted a five-year longitudinal study of more than 2,500 active drivers aged 65-79 in five sites across the United States. Participants were categorized as having previously been diagnosed with migraine symptoms (12.5%), no previous diagnosis but experienced symptoms during the study timeframe (1.3%) or never migraine respondents. Results indicate those with previous diagnosis did not have a different likelihood of having crashes after baseline, while those with new onset migraines were three times as likely to experience a crash within one year of diagnosis. However, previously diagnosed drivers experienced more hard braking events compared to adults who had never experienced a migraine.
Additionally, researchers examined the role medications commonly prescribed for migraines have in motor vehicle events and found that there was no impact on the relationship between migraines and either crashes or driving habits. However, few participants in the study sample were using acute migraine medications.
“These results have potential implications for the safety of older patients that should be addressed,” says DiGuiseppi. “Patients with a new migraine diagnosis would benefit from talking with their clinicians about driving safety, including being extra careful about other risks, such as distracted driving, alcohol, pain medication and other factors that affect driving.”

Like mail carriers who manage to deliver their parcels through snow, rain, heat and gloom, a critical group of mammalian proteins helps cells function properly even under less-than-ideal conditions.
Using state-of-the-art cell imaging and genome editing technology, University of Wisconsin-Madison scientists have begun to unravel how this collection of proteins performs its essential service. The discovery could eventually help researchers better understand and develop new treatments for diseases like cancer, diabetes and those that cause immune dysfunction.
Led by Anjon Audhya, a professor in the Department of Biomolecular Chemistry, the research team sought to better understand how the Coat Protein Complex II, or COPII, functions. COPII is an enormously important group of proteins responsible for transporting roughly a third of all proteins that function in mammalian cells.
COPII was a subject of the 2013 Nobel Prize in Physiology or Medicine, which was awarded to a trio of scientists for their work defining how proteins are sorted and transported around cells. This new research builds on some of those discoveries.
There are millions of proteins inside mammalian cells, and they perform a wide variety of duties. Cells must ensure that proteins are moved efficiently to their proper places, so they can perform their cellular roles — an intricate task requiring precision. Previous research identified COPII as an essential part of this process, but no one had recorded exactly how this set of proteins goes about packaging and transporting other proteins around cells.
To do so, Audhya and his colleagues used the CRISPR/Cas9 genome editing tool to add a tag, which could be chemically linked to a bright, fluorescent dye, to individual proteins involved in controlling the traffic flow within cells, including some that make up the COPII complex. With the tag, the scientists could follow the proteins as they moved about living cells.
Using a technique called lattice light-sheet imaging, the team tracked how COPII helps get cellular proteins, including molecules destined for other places, where they’re supposed to go — something that had never been done before.

The team described their advance in a paper recently published in the journal Nature Communications. Audhya described it in terms of the postal system. Researchers knew that COPII functions like postal workers who pick up and deliver parcels, but they had never tracked these workers as they sorted packages through the cell’s distribution and delivery systems.
“We can now see that envelope in the mailbox, see how the mail carrier comes to the mailbox to pick up the letter and then drive away,” says Audhya, who is the senior associate dean for basic research, biotechnology and graduate studies at the School of Medicine and Public Health.
The researchers discovered that, on average, this delivery process takes between 45 and 60 seconds under normal conditions. However, when cells receive subpar nutrition, as they sometimes do thanks to certain diseases and environmental conditions, this process slows down significantly, at least until cells can adapt over time.
Through a series of experiments, Audhya and his colleagues were able to identify a single protein named Sec23 that was capable of helping restore COPII’s trafficking system after disruption. When the scientists increased how much Sec23 was produced inside cells, they saw a change in the rate in which cells transported proteins, “something we never anticipated when we started this work,” Audhya says. “Sec23 seems to be the central player in regulating the function of the COPII complex.”
Identifying what triggers Sec23 to promote COPII function has potential implications for a number of diseases. For instance, cancer cells often grow prodigiously in nutrient-starved environments, in part by producing more of certain proteins that promote growth. Understanding the molecular mechanisms that underlie this property could identify new targets for therapies.
Beyond that, a more precise picture of the process by which cells correctly prepare and deliver proteins can help inform our basic understanding of proper cell function and what can go awry in diseases such as cancer, Type 2 diabetes, neurodegenerative conditions and immune disorders.
“Understanding these fundamental processes and the regulatory systems that exist in cells can ultimately pave the way to developing more rational approaches to disease intervention,” says Audhya.
This work was supported in part by National Institutes of Health grants GM134865 and GM008688, as well as shared resources available in the UWCCC Flow Cytometry Laboratory and the UW Optical Imaging Core.

Many bacterial pathogens use small injection apparatuses to manipulate the cells of their hosts, such as humans, so that they can spread throughout the body. To do this, they need to fill their syringes with the relevant injection agent. A technique that tracks the individual movement of proteins revealed how bacteria accomplish this challenging task.
Disease-causing bacteria of the genus Salmonella or Yersinia can use tiny injection apparatuses to inject harmful proteins into host cells, much to the discomfort of the infected person. However, it is not only with a view to controlling disease that researchers are investigating the injection mechanism of these so-called type III secretion systems, also known as “injectisomes.”
If the structure and function of the injectisome were fully understood, researchers would be able to hijack it to deliver specific drugs into cells, such as cancer cells. In fact, the structure of the injectisome has already been elucidated. However, it remained unclear how the bacteria load their syringes so that the right proteins are injected at the right time.
Mobile components of the injectisome search for proteins
A team of scientists led by Andreas Diepold from the Max Planck Institute for Terrestrial Microbiology in Marburg and Ulrike Endesfelder from the University of Bonn has now been able to answer this question: mobile components of the injectisome comb through the bacterial cell in search of the proteins to be injected, so-called effectors. When they encounter an effector, they transport it like a shuttle bus to the gate of the injection needle.
“How proteins of the sorting platform in the cytosol bind to effectors and deliver the cargo to the export gate of the membrane-bound injectisome is comparable to the processes at a freight terminal,” explains Stephan Wimmi, first author of the study as a postdoctoral researcher in Andreas Diepold’s laboratory. “We think that this shuttle mechanism helps to make the injection efficient and specific at the same time — after all, the bacteria have to inject the right proteins quickly to avoid being recognized and eliminated by the immune system, for example.”
To gain this insight into the important loading mechanism of the injectisome, the researchers had to apply new techniques. “Conventional methods, which are normally used to detect that proteins bind to each other, did not work to answer this question — possibly because the effectors are only bound for a short time and then immediately injected,” explains Andreas Diepold, research group leader at the Max Planck Institute and co-leader of the study. “That’s why we had to analyse this binding in situ in the living bacteria.”
“To measure these transient interactions we made use of two novel approaches that work in living cells, proximity labeling and single-particle tracking,” adds Ulrike Endesfelder, whose group worked on the study in three different locations — the Max Planck Institute in Marburg, Carnogie Mellon University in Pittsburgh, PA, USA, and at the University in Bonn. Proximity labeling, in which a protein marks its immediate neighbors like a paintbrush, enabled them to show that the effectors in the bacterium bind to the mobile injectisome components. This binding was examined in more detail using single particle tracking, a high-resolution microscopy method that can follow individual proteins in cells. These methods, which the team refers to as “in situ biochemistry,” i.e. biochemical investigations on site, made the breakthrough possible.
The researchers next want to use their method to investigate other mechanisms that bacteria use to cause infections. “The more we know about how bacteria use these systems during an infection, the better we can understand how we can influence them — be it to prevent infections or to modify the systems in order to use them in the fields of medicine or biotechnology,” says Andreas Diepold.

Mutations of the tumor suppressor p53 not only have a growth-promoting effect on the cancer cells themselves, but also influence the cells in the tumor’s microenvironment. Scientists at the German Cancer Research Center (DKFZ) and the Weizmann Institute in Israel have now shown that p53-mutated mouse breast cancer cells reprogram fat cells. The manipulated fat cells create an inflammatory microenvironment, impairing the immune response against the tumor and thus promoting cancer growth.
No other gene is mutated as frequently in human tumors as the gene for the tumor suppressor p53. In around 30 percent of all cases of breast cancer, the cancer cells show mutations or losses in the p53 gene. These mutations restrict the ability of p53 to acta as a “cancer brake” p53 and to prevent the development and progression of cancer.
The effects of p53 mutations in the cancer cells themselves have already been intensively researched. However, the understanding that p53 mutations in cancer cells can also affect cells in the tumor’s microenvironment — and thus additionally drive cancer growth — is only slowly growing.
A team of researchers led by Almut Schulze from the DKZF and Moshe Oren from the Weizmann Institute in Israel investigated the effects of p53 mutations in breast cancer cells on fat cells, known as adipocytes. During the progression of breast cancer, adipocytes, one of the main cell types in breast tissue, undergo a transformation. Research results indicate that this increases the aggressiveness and resistance to therapy of the surrounding breast cancer cells.
Schulze and Oren’s team have now demonstrated this in adipocytes from mouse breast tissue: The cancer-promoting properties of adipocytes are potentiated when the breast cancer cells carry p53 mutations.
The researchers treated immature adipocytes with culture medium in which breast cancer cells with or without p53 mutations had previously grown. This treatment triggered profound changes in metabolism and gene activity in the adipocytes and increased the production of pro-inflammatory messengers. The maturation of the adipocytes was prevented, while mature fat cells were returned to an immature stage. These effects were only mild after treatment with cell culture media from breast cancer cells with functioning p53, but were very clear in the case of medium from cancer cells with mutated p53.
The researchers then transferred breast cancer cells with mutated or functional p53 together with pre-treated fat cells to mice and compared the resulting tumors. If p53 was mutated in the cancer cells, the number of immunosuppressive myeloid cells in the tumor increased. The migrated immune cells carried more PD-L1 on their surface, which acts as a potent brake on the immune defense of tumors.
A particularly surprising result was that breast cancer cells with certain p53 mutations were able to reprogram neighboring precursor fat cells — directly or indirectly — to be even more pro-inflammatory than breast cancer cells that had completely lost the tumor suppressor p53.
“p53 defects in breast cancer cells appear to be the central driver of tumor-promoting reprogramming of fat cells,” summarizes Almut Schulze, who led the study together with Moshe Oren. “Fat cells are an essential component of breast tissue and can therefore have a massive influence on tumor progression. A detailed understanding of the interaction between p53-mutated cancer cells and adipocytes could therefore provide new clues as to how the progression of breast cancer can be halted.”

Diffuse gliomas are malignant brain tumors that cannot be optimally examined by means of conventional MRI imaging. So-called amino acid PET scans are better able to image the activity and spread of gliomas. An international team of researchers (RANO Working Group), led by scientists from LMU and the Medical University of Vienna, has now drawn up the first ever international criteria for the standardized imaging of gliomas using amino acid PET. It has published its results in the journal The Lancet Oncology.

Under the joint leadership of nuclear physician Nathalie Albert from LMU and oncologist Professor Matthias Preusser from the Medical University of Vienna, the RANO group has developed new criteria for assessing the success of therapies for diffuse gliomas. These malignant brain tumors develop out of glial cells in the brain. Tumors of this kind are generally aggressive and difficult to treat. The RANO group has developed criteria that permit evaluation of the success of treatment using positron emission tomography (PET). Called PET RANO 1.0, these PET-based criteria open up new possibilities for the standardized assessment of diffuse gliomas.
Comparable criteria now available for interpreting PET images
PET is an imaging technique that uses a radioactive tracer to measure metabolic processes in the body. Amino acid PET is used in the diagnosis of diffuse gliomas, with tracers that work on a protein basis (amino acids) and accumulate in brain tumors. Nathalie Albert explains: “PET imaging with radioactively labeled amino acids has proven extremely valuable in neuro-oncology and permits reliable representation of the activity and extension of gliomas. Although amino acid PET has been used for years, it had not been evaluated in a structured manner before now. In contrast to MRI-based diagnostics, there have been no criteria for interpreting these PET images.” According to the researchers, the new criteria allow PET to be used in clinical studies and everyday clinical practice and create a foundation for future research and the comparison of treatments for improved therapies.
The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary consortium founded to develop standardized new response criteria for clinical studies relating to brain tumors. Comprising experts from various fields, the group has been developing criteria to serve as standard references for assessing various clinically relevant aspects for more than a decade.
Research team draws up criteria for PET-based examinations of malignant brain tumors
Diffuse gliomas are malignant brain tumors that cannot be optimally examined by means of conventional MRI imaging. So-called amino acid PET scans are better able to image the activity and spread of gliomas. An international team of researchers (RANO Working Group), led by scientists from LMU and the Medical University of Vienna, has now drawn up the first ever international criteria for the standardized imaging of gliomas using amino acid PET.
Under the joint leadership of nuclear physician Nathalie Albert from LMU and oncologist Professor Matthias Preusser from the Medical University of Vienna, the RANO group has developed new criteria for assessing the success of therapies for diffuse gliomas. These malignant brain tumors develop out of glial cells in the brain. Tumors of this kind are generally aggressive and difficult to treat. The RANO group has developed criteria that permit evaluation of the success of treatment using positron emission tomography (PET). Called PET RANO 1.0, these PET-based criteria open up new possibilities for the standardized assessment of diffuse gliomas.
Comparable criteria now available for interpreting PET images
PET is an imaging technique that uses a radioactive tracer to measure metabolic processes in the body. Amino acid PET is used in the diagnosis of diffuse gliomas, with tracers that work on a protein basis (amino acids) and accumulate in brain tumors. Nathalie Albert explains: “PET imaging with radioactively labeled amino acids has proven extremely valuable in neuro-oncology and permits reliable representation of the activity and extension of gliomas. Although amino acid PET has been used for years, it had not been evaluated in a structured manner before now. In contrast to MRI-based diagnostics, there have been no criteria for interpreting these PET images.” According to the researchers, the new criteria allow PET to be used in clinical studies and everyday clinical practice and create a foundation for future research and the comparison of treatments for improved therapies.
The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary consortium founded to develop standardized new response criteria for clinical studies relating to brain tumors. Comprising experts from various fields, the group has been developing criteria to serve as standard references for assessing various clinically relevant aspects for more than a decade.

A UC Riverside study to motivate your new year’s resolutions: it demonstrates that high-fat diets affect genes linked not only to obesity, colon cancer and irritable bowels, but also to the immune system, brain function, and potentially COVID-19 risk.
While other studies have examined the effects of a high-fat diet, this one is unusual in its scope. UCR researchers fed mice three different diets over the course of 24 weeks where at least 40% of the calories came from fat. Then, they looked not only at the microbiome, but also at genetic changes in all four parts of the intestines.
One group of mice ate a diet based on saturated fat from coconut oil, another got a monounsaturated, modified soybean oil, a third got an unmodified soybean oil high in polyunsaturated fat. Compared to a low-fat control diet, all three groups experienced concerning changes in gene expression, the process that turns genetic information into a functional product, such as a protein.
“Word on the street is that plant-based diets are better for you, and in many cases that’s true. However, a diet high in fat, even from a plant, is one case where it’s just not true,” said Frances Sladek, a UCR cell biology professor and senior author of the new study.
A new Scientific Reports paper about the study documents the many impacts of high-fat diets. Some of the intestinal changes did not surprise the researchers, such as major changes in genes related to fat metabolism and the composition of gut bacteria. For example, they observed an increase in pathogenic E. coli and a suppression of Bacteroides, which helps protect the body against pathogens.
Other observations were more surprising, such as changes in genes regulating susceptibility to infectious diseases. “We saw pattern recognition genes, ones that recognize infectious bacteria, take a hit. We saw cytokine signaling genes take a hit, which help the body control inflammation,” Sladek said. ‘So, it’s a double whammy. These diets impair immune system genes in the host, and they also create an environment in which harmful gut bacteria can thrive.”
The team’s previous work with soybean oil documents its link to obesity and diabetes, both major risk factors for COVID. This paper now shows that all three high-fat diets increase the expression of ACE2 and other host proteins that are used by COVID spike proteins to enter the body.

Additionally, the team observed that high-fat food increased signs of stem cells in the colon. “You’d think that would be a good thing, but actually they can be precursors to cancer,” Sladek said.
In terms of effects on gene expression, coconut oil showed the greatest number of changes, followed by the unmodified soybean oil. Differences between the two soybean oils suggest that polyunsaturated fatty acids in unmodified soybean oil, primarily linoleic acid, play a role in altering gene expression.
Negative changes to the microbiome in this study were more pronounced in mice fed the soybean oil diet. This was unsurprising, as the same research team previously documented other negative health effects of high soybean oil consumption.
In 2015, the team found that soybean oil induces obesity, diabetes, insulin resistance, and fatty liver in mice. In 2020, the researchers team demonstrated the oil could also affect genes in the brain related to conditions like autism, Alzheimer’s disease, anxiety, and depression.
Interestingly, in their current work they also found the expression of several neurotransmitter genes were changed by the high fat diets, reinforcing the notion of a gut-brain axis that can be impacted by diet.
The researchers have noted that these findings only apply to soybean oil, and not to other soy products, tofu, or soybeans themselves. “There are some really good things about soybeans. But too much of that oil is just not good for you,” said UCR microbiologist Poonamjot Deol, who was co-first author of the current study along with UCR postdoctoral researcher Jose Martinez-Lomeli.

Also, the studies were conducted using mice, and mouse studies do not always translate to the same results in humans. However, humans and mice share 97.5% of their working DNA. Therefore, the findings are concerning, as soybean oil is the most commonly consumed oil in the United States, and is increasingly being used in other countries, including Brazil, China, and India.
By some estimates, Americans tend to get nearly 40% of their calories from fat, which mirrors what the mice were fed in this study. “Some fat is necessary in the diet, perhaps 10 to 15%. Most people though, at least in this country, are getting at least three times the amount that they need,” Deol said.
Readers should not panic about a single meal. It is the long-term high-fat habit that caused the observed changes. Recall that the mice were fed these diets for 24 weeks. “In human terms, that is like starting from childhood and continuing until middle age. One night of indulgence is not what these mice ate. It’s more like a lifetime of the food,” Deol said.
That said, the researchers hope the study will cause people to closely examine their eating habits.
“Some people think, ‘Oh, I’ll just exercise more and be okay. But regularly eating this way could be impacting your immune system and how your brain functions,” Deol said. “You may not be able to just exercise away these effects.”