Research Roundup: New Abnormal Tau Protein IDed in Alzheimer’s Disease and More
Every week there are numerous scientific studies published. Here’s a look at some of the more interesting ones.
New Tau Protein is Abnormal in Very Early Alzheimer’s Disease
Investigators with the University of Gothenburg identified new forms of tau protein that become abnormal in the very early stages of Alzheimer’s disease, even before the development of cognitive problems. They created new assays that can detect these subtle changes and validated their results in human samples. They conducted the research with colleagues at the Barcelona Beta Research Centre in Spain, the University Medical Centre in Ljubljana, Slovenia, and the University of Paris. They published their research in the journal Alzheimer’s & Dementia.
“The remarkable findings reported in these publications show that the new highly sensitive tools capture the earliest Alzheimer disease changes in the brain in clinically normal people,” said Thomas Karikari, assistant professor at the University of Gothenburg, who led the study. “These tools, therefore, have the potential to advance population screening and clinical trials.”
Two abnormal proteins are associated with Alzheimer’s disease, tau and beta-amyloid. Both form aggregates that progressively accumulate in the brain. The tau aggregate into finely-ordered fibrillar structures helped along by phosphorylation. Beta-amyloid typically accumulates years earlier than abnormal tau. However, the researchers found there are specific types of p-tau that undergo tiny increases in cerebrospinal fluid and blood in people with emerging Alzheimer’s pathology. In a study of people with brain evidence of Alzheimer’s but no cognitive problems, they were able to correctly identify the p-tau abnormalities emerging in spinal fluid and blood samples.
How SARS-CoV-2 Damages Human Lung Cells
Scientists with Boston University School of Medicine identified host proteins and pathways in lung cells whose levels changed during COVID-19. This is the first map of the molecular responses of human lung cells to infection by SARS-CoV-2. A specific protein modification, phosphorylation, becomes abnormal in the infected lung cells. The phosphorylation of proteins has a major role in regulating protein function inside cells—these processes are typically highly controlled in normal, healthy cells. But the SARS-CoV-2 creates havoc, causing abnormal protein amounts and frequency of protein phosphorylation. The changes help the virus to multiply and eventually destroy the cells. This insight may potentially lead to new drug targets.
Kidney Disease Leading Risk Factor for COVID-related Hospitalization
Investigators analyzed Geisinger Health System’s electronic health records and found that chronic kidney disease is the leading risk factor for COVID-19 hospitalization. They analyzed the health records of 12,971 people tested for COVID-19 with the Geisinger system from March 7 to May 19. Of them, 1,604 were COVID-positive and 354 required hospitalization. In analyzing the records for associations with specific clinical conditions, they found chronic kidney disease was most heavily associated with hospitalization, and COVID-19 patients with end-stage renal disease were 11 times more likely to be hospitalized than COVID-19 patients without kidney disease. Why this is the case isn’t completely clear, although they believe the physiological stress caused by an excessive inflammatory response to COVID-19 infection may destabilize organs already weakened by chronic disease. They also note that the kidney and heart are the tissues with the highest expression of ACE2, a SARS-CoV-2 receptor.
How Does Long-Term Memory Work?
Scientists at the University of Basel (Switzerland) identified a molecular mechanism that plays a key role in intact long-term memory. It is also a factor in physiological memory loss in old age. By studying roundworms (Caenorhabditis elegans) that lacked the mps-2 gene, with learning and memory modifications, found that the modified worms’ short-term memory was just as good as unmodified worms. But as the experiments went on longer, the genetically modified worms were less able to retain what they learned. In short, without mps-2, their long-term memory was reduced. They were able to prove that the lack of the mps-2 gene resulted in decreased MPS-2 protein, which is an actively regulated process. Another protein, NHR-66, regulated the deficiency by actively curbing the reading of the mps-2 gene and, as a result, production of the MPS-2 protein in old age. By artificially inducing MPS-2 protein in older worms, or turning off their NHR-66, they created older worms with memory as good as younger worms.
Chemicals Found in Certain Foods Inhibit a Key SARS-CoV-2 Enzyme
Researchers with North Carolina State University found that certain chemical compounds found in foods or beverages like green tea, muscadine grapes and dark chocolate can bind to and block a particular enzyme in the SARS-CoV-2 virus, which causes COVID-19. They analyzed how certain proteases in the virus reacted when exposed to different plant chemical compounds that were already linked to anti-inflammatory and antioxidant properties. Their computer simulations showed compounds from green tea, two varieties of muscadine grapes, cacao powder and dark chocolate bound to different portions of Mpro, which the virus requires for replication.
Smell Training to Recover Sense of Smell After COVID-19
One peculiar aspect of COVID-19, exhibited in about 80% of patients, is a loss of smell. In some cases, this affects the sense of smell (and taste) long-term, well after the infection is gone. It can also result in smell distortions, such as lemon smelling like gasoline, for example. Researchers at the University of East Anglia have found that “smell training” could help regain the normal sense of smell.
“Some degree of smell loss is thought to affect up to one-quarter of the general population,” said Carl Philpott, of the UAE’s Norwich Medical School. “Smell loss is also a prominent symptom of COVID-19, and we know that the pandemic is leaving many people with long-term smell loss, or smell distortions such as parosmia—this may now be as many as 90,000 people in the UK.”
Smell training involves sniffing at least four different odors twice a day every day for several months. It appears to be a simple and side-effect free treatment for various causes of smell loss. They published their research in the journal The Laryngoscope.