Research Roundup: How Tau Proteins Spread in Alzheimer’s and More
Every week there are numerous scientific studies published. Here’s a look at some of the more interesting ones.
Toxic Tau Proteins Spread in Alzheimer’s Patients Via Connected Neurons
Two abnormal proteins are associated with Alzheimer’s disease, beta-amyloid and tau. A study out of Lund University in Sweden and McGill University in Canada showed how toxic tau in the human brain in elderly individuals spreads by way of connected neurons. They also found that beta-amyloid facilitates the spread of toxic tau. The research was published in the journal Nature Communications.
“Our research suggests that toxic tau may spread across different brain regions through direct neuronal connections, much like infectious diseases may spread to different cities through different transportation pathways,” said lead author Jacob Vogel from McGill. “The spread is restricted during normal aging, but in Alzheimer’s disease the spread may be facilitated by beta-amyloid, and likely leads to widespread neuronal death and eventually dementia.”
Beta-amyloid forms plaques in the brain and tau forms tangles within brain cells. Toxic tau, in particular, has been linked to brain degeneration and cognitive symptoms. In general, beta-amyloid appears earlier in the disease with tau appearing later.
“Our findings have implications for understanding the disease, but more importantly for the development of therapies against Alzheimer’s, which are directed against either beta-amyloid or tau,” said Oskar Hansson, co-lead investigator of the study and professor of neurology at Lund. “Specifically, the results suggest that therapies that limit uptake of tau into the neurons or transportation or excretion of tau, could limit disease progression.”
Improving on Gene Therapy by Decreasing Immune Response to AAV
Biotech company Spark Therapeutics published research in the journal Nature Medicine showing that treatment with immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS0 caused fast and transient decrease of neutralizing anti-adeno-associated virus (AAV) antibodies and restored gene therapy efficacy in laboratory animals. The study was conducted by Spark, Genethon, the Centre de Recherche des Cordeliers (Inserm, Sorbonne Universite, Universite de Paris) and the National Centre for Scientific Research (CNRS) in France.
Biggest Risk Factors for Severe COVID-19 in UK
In a large cohort study published in The BMJ of COVID-19 patients in the UK, the biggest risk factors for severe disease or death were found to be age over 50, being male, obese, or having underlying heart, lung, liver and kidney disease. The study, which is still ongoing, recruited over 43,000 patients. The study essentially looked at data from a third of all COVID-19 patients admitted to hospitals in the UK between February 6 and April 19, 2020. Overall, the data confirms studies conducted in China, although obesity was not highlighted in the China data. The researchers believe that reduced lung function or obesity-related inflammation are the factors involved in increased disease severity or mortality in obese patients.
Warmer Temperatures Slow COVID-19—A Little Bit
Researchers at Mount Auburn Hospital evaluated the impact of temperature, precipitation and UV index on COVID-19 cases in the U.S. during the spring of 2020. They found that while the rate of COVID-19 incidence decreases with warmer temperatures up to 52 degrees F, anything warmer than that does not decrease disease transmission all that much. Precipitation doesn’t seem to have any effect and UV index helps a little bit. The bottom line, they say, is that their research supports what the Centers for Disease Control and Prevention (CDC) is saying, which is that although the pandemic might abate a little bit in the summer, it is expected to be worse in the fall and winter.
Antibodies Against Alzheimer’s Toxic Particles
Investigators at the University of Cambridge have identified a method to design an antibody that can seek out and attack the toxic particles that destroy healthy brain cells, such as in Alzheimer’s disease. These antibodies recognize amyloid-beta oligomers. They believe this could lead to new diagnostics or possible treatments for Alzheimer’s and other types of dementia.
“Oligomers are difficult to detect, isolate, and study,” said Francesco Aprile, the study’s lead author. “Our method allows the generation of antibody molecules able to target oligomers despite their heterogeneity, and we hope it could be a significant step towards new diagnostic approaches.”
Physical Distancing, Masks and Eye Protection Help Prevent COVID-19
As has been suggested all along, the use of physical distancing, face masks and eye protection does appear, in a systematic review of the literature by researchers at McMaster University, to help prevent the transmission of COVID-19. The two meters (about six feet) physical distancing seems to prevent person-to-person transmission and face masks and eye protect decrease the risk of infection.
“Although the direct evidence is limited, the use of masks in the community provides protection, and possibly N95 or similar respirators worn by health care workers suggest greater protection than other face masks,” said Holger Schunemann, professor of the departments of health research methods, evidence, and impact, and medicine at McMaster. “Availability and feasibility and other contextual factors will probably influence recommendations that organizations develop about their use. Eye protection may provide additional benefits.”
The review was led by McMaster researchers, but also included a large, international collaboration of researchers, front-line and specialist clinicians, epidemiologists, patients, public health and health policy experts of published and unpublished studies in any language. They also evaluated direct evidence on COVID-19 and indirect evidence on other coronaviruses, such as the ones that cause SARS and MERS. Although there were no randomized control trials addressing the three coronaviruses (SARS, MERS and COVID-19), they found 44 relevant comparative studies in health care and community settings across 16 countries and six continents from inception to early May 2020. The study was published in The Lancet.