Extracellular vesicles (EVs) are small membrane-bound particles that are loaded with various proteins, RNA, DNA, and lipids, and secreted by cells. Interest in these vesicles has grown in recent years with mounting evidence that EVs act as intercellular communication systems, transferring their selected cargo to other cells to confer specific effects on target cell biology. However, the processes that direct specific RNAs and proteins into these specialized vesicles remain largely unknown. In the April 25th, 2022 edition of Developmental Cell, Alissa Weaver, M.D., Ph.D. and her research team at the Vanderbilt Center for Extracellular Vesicle Research have uncovered subcellular hubs of EV formation that selectively assemble RNA-containing EVs. These hubs are located at membrane contact sites (MCS) where the endoplasmic reticulum (ER) interacts with EV biogenesis membranes, including late endosomal multivesicular bodies (MVBs) (ER-MVB MCS). Shedding much needed mechanistic light, the group further pinpointed the ER MCS membrane tether protein VAP-A and its binding partner ceramide transfer protein (CERT) as key drivers in this process.

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This blog originated as a press release from the Swiss National Centre of Competence in Research SYNAPSY. Thanks to them for allowing us to repost it here.

A research team from Synapsy has shown that the severity of the clinical symptoms of schizophrenia is strongly linked to blood biomarkers related to the deregulation of neuronal mitochondria.

Psychotic symptoms are a characteristic clinical manifestation of schizophrenia. They go hand-in-hand with an increase in oxidative stress, which results in damage to a particular type of neurons called parvalbumin neurons. This deterioration leads to dysfunction in the activity of the prefrontal cortex, a region of the brain that is involved in cognition. A study conducted at the Centre for Psychiatric Neuroscience of the Lausanne University (UNIL) and the Lausanne University Hospital (CHUV), and supported by the National Centre of Competences in Research Synapsy (Synapsy), has shown, in an animal model, that the cellular mechanism for recycling mitochondria is deficient in parvalbumin neurons. The study – published in the journal Molecular Psychiatry – investigated the underlying biochemical mechanisms, pinpointing two key molecules, miR-137 and COX6A2, that can be detected in blood. When used as biomarkers in patients diagnosed with psychosis, they unveil two distinct clinical sub-groups with different severity of symptoms, cognitive deficits, and functioning in everyday life. This discovery represents a major breakthrough for stratifying individuals suffering from schizophrenia, whose heterogeneity of symptoms currently restricts diagnosis and treatment.

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This blog originated as a press release from the UCSD Jacobs School of Engineering. Thanks to them for allowing us to repost it here.

Nanoengineers at the University of California San Diego have developed a new and potentially more effective way to deliver messenger RNA (mRNA) into cells. Their approach involves packing mRNA inside nanoparticles that mimic the flu virus –– a naturally efficient vehicle for delivering genetic material such as RNA into cells.

The new mRNA delivery nanoparticles are described in a paper published recently in the journal Angewandte Chemie International Edition.

The work addresses a major challenge in the field of drug delivery: getting large biological drug molecules safely into cells and protecting them from organelles called endosomes. These tiny acid-filled bubbles inside the cell serve as barriers that trap and digest large molecules that try to enter. In order for biological therapeutics to do their job once they are inside the cell, they need a way to escape the endosomes.

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This blog originated as a press release from the German Center for Neurodegenerative Diseases. Thanks to them for allowing us to repost it here.

Researchers at the German Center for Neurodegenerative Diseases (DZNE) and the University Medical Center Göttingen (UMG) have identified molecules in the blood that can indicate impending dementia. Their findings, which are presented in the scientific journal EMBO Molecular Medicine, are based on human studies and laboratory experiments. Various university hospitals across Germany were also involved in the investigations. The biomarker described by the team led by Prof. André Fischer is based on measuring levels of so-called microRNAs. The technique is not yet suitable for practical use; the scientists therefore aim to develop a simple blood test that can be applied in routine medical care to assess dementia risk. According to the study data, microRNAs could potentially also be targets for dementia therapy.

“When symptoms of dementia manifest, the brain has already been massively damaged. Presently, diagnosis happens far too late to even have a chance for effective treatment. If dementia is detected early, the odds of positively influencing the course of the disease increase,” says André Fischer, research group leader and spokesperson at the DZNE site in Göttingen and professor at the Department of Psychiatry and Psychotherapy at UMG. “We need tests that ideally respond before the onset of dementia and reliably estimate the risk of later disease. In other words, tests that give an early warning. We are confident that our current study results pave the way for such tests.”

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This blog originated as a press release from MIT News. Thanks to them for allowing us to repost it here.

A new RNA-based control switch could be used to trigger production of therapeutic proteins to treat cancer or other diseases.

Researchers at MIT and Harvard University have designed a way to selectively turn on gene therapies in target cells, including human cells. Their technology can detect specific messenger RNA sequences in cells, and that detection then triggers production of a specific protein from a transgene, or artificial gene.

Because transgenes can have negative and even dangerous effects when expressed in the wrong cells, the researchers wanted to find a way to reduce off-target effects from gene therapies. One way of distinguishing different types of cells is by reading the RNA sequences inside them, which differ from tissue to tissue.

By finding a way to produce transgene only after “reading” specific RNA sequences inside cells, the researchers developed a technology that could fine-tune gene therapies in applications ranging from regenerative medicine to cancer treatment. For example, researchers could potentially create new therapies to destroy tumors by designing their system to identify cancer cells and produce a toxic protein just inside those cells, killing them in the process.

“This brings new control circuitry to the emerging field of RNA therapeutics, opening up the next generation of RNA therapeutics that could be designed to only turn on in a cell-specific or tissue-specific way,” says James Collins, the Termeer Professor of Medical Engineering and Science in MIT’s Institute for Medical Engineering and Science (IMES) and Department of Biological Engineering and the senior author of the study.

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This blog originated as a press release from the Max Planck Institute for Medical Research in Heidelberg. Thanks to them for allowing us to repost it here.

Scientists create synthetic exosomes with natural functionalities and present their therapeutic application.

Scientists from the Max Planck Institute for Medical Research in Heidelberg and colleagues at the DWI Leibniz Institute for Interactive Materials in Aachen have engineered synthetic exosomes that regulate cellular signaling during wound closure. The synthetic structures are built to resemble naturally occurring extracellular vesicles (EV) that play a fundamental role in communication between cells during various processes in our bodies. The scientists uncovered key mechanisms in the regulation of wound healing and the formation of new blood vessels. They designed and built programmable fully-synthetic EVs from scratch rather than isolating natural EVs from cells. Inspired by the roles of the natural counterparts, the scientists demonstrate for the first time that fully synthetic exosomes with therapeutic functions can be constructed.

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This blog originated as a press release from the Technical University of Denmark (DTU). Thanks to them for allowing us to repost it here.

DTU Health Tech researchers have developed a method for detection of SARS-CoV-2 RNA that can be adapted to detect other diseases.

Current SARS-CoV-2 RNA detection methods recommended by the World Health Organization profoundly rely on the roles of biological enzymes. High cost, stringent transportation and storage conditions, as well as a global supply shortage of enzymes, limit large-scale testing. The result is that most countries have to prioritize testing on vulnerable cases, which creates delay in diagnostics and identification of positive cases, which again can hamper pandemic mitigation and suppression.

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) is still the gold standard for whole genome detection and has been playing a key role in controlling the COVID-19 pandemic. However, the sample-to-result time for qRT-PCR is several hours, and the method requires a complex thermocycler instrument to raise and lower the temperature of the reaction in discrete steps.

Simpler and less expensive

Non-enzymatic isothermal amplification methods, being simpler and faster, have shown promising potential to substitute for qRT-PCR. Although these methods perform very well when the target gene is short, they are yet to function efficiently for detection of whole viral genomes (long DNA or RNA targets).

During the COVID-19 pandemic, the Euro area alone experienced a 3.8% drop in GDP within the first quarter of 2020 (Eurostat 2020). Thus, developing a lower-cost methodology for pathogen detection would be highly beneficial for both patients and the healthcare systems aiming to battle future pandemics.

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