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Archive - Sep 5, 2018

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Exosomes Carry Dopamine into Brains of Mice in Parkinson’s Study

According to an article written by Alice Melao and published on September 5, 2018 in Parkinson’s Disease Today, tiny fatty vesicles that naturally circulate in the blood can effectively carry medications into the central nervous system, including into the brain, an early study in mice suggests. These blood vesicles, called exosomes, were able to successfully deliver dopamine directly to specific areas of the brain affected by Parkinson’s disease. The research study, “Dopamine-Loaded Blood Exosomes Targeted to Brain for Better Treatment of Parkinson’s Disease,” was published in the October 10, 2018 issue of Journal of Controlled Release. Parkinson’s disease is characterized by the progressive degeneration and death of nerve cells in the brain that produce dopamine (called dopaminergic neurons). Dopamine is a critical signaling molecule that regulates brain cell activity and function. Melao noted that, given the disease’s progressive nature researchers have focused on finding ways to prevent the death of dopaminergic neurons or to restore brain levels of dopamine. But a major challenge has been getting potential therapeutic agents across the blood-brain barrier — a semi-permeable membrane that protects the brain — and reach targeted areas. Researchers at Sichuan University in China explored the possibility of using exosomes as a vehicle for dopamine transport. The team isolated and purified exosomes from blood of mice, and labeled them with a green fluorescent tag to be able to track them easily. When researchers used these exosomes in mouse brain cells grown in the laboratory, they confirmed that the vesicles merged with cell membranes, and their content was released inside the cell, turning it green.

Protein Aggregates Appear to Be Driving Force in Development of ALS (Lou Gehrig’s Disease)

A mechanism for how the disease ALS (amyotrophic lateral sclerosis, also called Lou Gehrig’s disease) evolves has been illuminated at Umeå University, Sweden. This was reported in a September 4, 2018 release from Umeå University, Sweden. The discovery concerns how proteins with a defective structure spread the deformation to other proteins. This according to results in a new thesis. The findings can open up for novel pharmaceutical developments in the future. "We've been able to identify two different types of protein aggregates with different structures and propagation abilities. One type gave rise to a more aggressive disease progression, which shows that these aggregates are the driving force in the development of ALS," says Johan Bergh, MD, doctoral student at the Department of Medical Biosciences at Umeå University, Sweden. Together with the ALS group at Umeå University, Bergh has developed a method of investigating protein aggregates formed in ALS. With this new method, it has then been possible to identify the particular protein aggregates that are driving in the emergence of ALS. The protein that has been targeted is superoxide dismutase-1 (SOD1). It has long been known that mutations in that protein can cause ALS. The goal of the research team was to investigate the way in which the protein contributes to the disease. In several diseases afflicting the nervous system, such as in Alzheimer's and Parkinson's Disease, new studies show that some proteins assume an aberrant structure. Misfolded proteins aggregate and provoke other proteins of the same kind to assume the same structure. In this way, the disease spreads step by step into the nervous system. "Using the new method, we have shown and confirmed through animal models that the development of ALS follows the same principle as for other severe nervous disorders.

Neutrophil Nanosponges Soak Up Proteins That Promote Rheumatoid Arthritis

Engineers at the University of California San Diego have developed neutrophil "nanosponges" that can safely absorb and neutralize a variety of proteins that play a role in the progression of rheumatoid arthritis. Injections of these nanosponges effectively treated severe rheumatoid arthritis in two mouse models. Administering the nanosponges early on also prevented the disease from developing. The work was published online on September 3, 2018 in Nature Nanotechnology. The article is titled “Neutrophil Membrane-Coated Nanoparticles Inhibit Synovial Inflammation and Alleviate Joint Damage in Inflammatory Arthritis.” "Nanosponges are a new paradigm of treatment to block pathological molecules from triggering disease in the body," said senior author Dr. Liangfang Zhang, a nanoengineering professor at the UC San Diego Jacobs School of Engineering. "Rather than creating treatments to block a few specific types of pathological molecules, we are developing a platform that can block a broad spectrum of them, and this way we can treat and prevent disease more effectively and efficiently." This work is one of the latest examples of therapeutic nanosponges developed by Dr. Zhang's lab. Dr. Zhang, who is affiliated with the Institute of Engineering in Medicine and Moores Cancer Center at UC San Diego, and his team previously developed red blood cell nanosponges (http://jacobsschool.ucsd.edu/news/news_releases/release.sfe?id=1350) to combat and prevent MRSA (methicillin-resistant Staphylococcus aureus) infections and macrophage nanosponges (http://jacobsschool.ucsd.edu/news/news_releases/release.sfe?id=2400) to treat and manage sepsis. The new nanosponges are nanoparticles of biodegradable polymer coated with the cell membranes of neutrophils, a type of white blood cell.