SARS-CoV-2 Variants – (in mice)

Pre-print therefore not peer reviewed. No, I don’t hang out on Twitter all day long. Yes, the study is somewhat geeky. BUT here’s the money sentence:

This abrogation of the species barrier raises the possibility of wild rodent secondary reservoirs and provides new experimental models to study disease pathophysiology and countermeasures.

The B1.351 and P.1 variants extend SARS-CoV-2 host range to mice — https://www.biorxiv.org/content/10.1101/2021.03.18.436013v1

Now I can’t stop thinking about “secondary reservoirs”.

ACE2-interacting domain of SARS-CoV-2

In a study published in the Journal of Neuroimmune Pharmacology, mouse models with COVID-19 showed positive results when a small peptide was introduced nasally. The peptide proved effective in reducing fever, protecting the lungs, improving heart function and reversing cytokine storm — a condition in which an infection triggers the immune system to flood the bloodstream with inflammatory proteins. The researchers also report success in preventing the disease from progression.

Rush University Medical Center. “Potential COVID-19 drug is successful in lab study: Peptide reduced COVID-19 symptoms in mice.” ScienceDaily. http://www.sciencedaily.com/releases/2021/01/210119194322.htm (accessed January 20, 2021).

Journal Reference – Ramesh K. Paidi, Malabendu Jana, Rama K. Mishra, Debashis Dutta, Sumita Raha, Kalipada Pahan. ACE-2-interacting Domain of SARS-CoV-2 (AIDS) Peptide Suppresses Inflammation to Reduce Fever and Protect Lungs and Heart in Mice: Implications for COVID-19 Therapy. Journal of Neuroimmune Pharmacology, 2021; DOI: 10.1007/s11481-020-09979-8

Our neighbor Dr. Arlan Richardson at https://nathanshockcenters.org/oklahoma part of the University of Oklahoma Health Sciences Center knows a lot about mice. I’ll have to ask him what he thinks of the potential of this peptide for human use.

N501Y mutation in SARS-CoV-2 virus causes increased infectivity, disease severity in mice — Science Chronicle

Chinese researchers found N501Y mutation in a mouse-adapted SARS-CoV-2 virus strain. In the mouse model, the N501Y mutation was found to increase the binding affinity of the virus with the mouse ACE2 receptor. The mutation in the mouse-adapted strain also caused increased virulence. In a preliminary report posted on December 19, Dr. Andrew Rambaut from […]

N501Y mutation in SARS-CoV-2 virus causes increased infectivity, disease severity in mice — Science Chronicle

Interesting article and the last paragraphs must be emphasized.

Dr. Gagandeep Kang, Professor of Microbiology at CMC Vellore, however, cautions that emergence of N501Y mutation has been seen on other occasions. According to her, the N501Y mutation in a strain that has been adapted to infect a mouse model cannot be compared with the N501Y mutation seen in the new variant infecting humans. And the severity of diseases caused by the mutation in the mouse model has no relevance to humans, she says.

“At this time, one can only say the mutation increases binding affinity in humans and hence increased transmissibility. Nothing can be said about disease severity,” says Dr. Kang.  

Visceral fat delivers signal to the brain that hurts cognition

“We have identified a specific signal that is generated in visceral fat, released into the blood that gets through the blood brain barrier and into the brain where it activates microglia and impairs cognition.”

Visceral fat delivers signal to the brain that hurts cognition

Quote and article link presented without the usual sarcasm.

Molecule found in oranges could reduce obesity and prevent heart disease and diabetes

In mice, so don’t start gorging on oranges.

Sorry, sarcasm restriction didn’t last long.

Early studies on the diet suggested red wine was a major contributor to the health benefits of the Mediterranean diet because it contains a compound called resveratrol, which activated a certain pathway in cells known to increase lifespan and prevent aging-related diseases. However, work in Mashek’s lab suggests that it is the fat in olive oil, another component of the Mediterranean diet, that is actually activating this pathway.

Olive oil in the diet may also help mitigate aging-related diseases

 

High-protein diets boost artery-clogging plaque

High-protein diets boost artery-clogging plaque, mouse study shows

In mice.

The mice on the high-fat, high-protein diet developed worse atherosclerosis — about 30% more plaque in the arteries — than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.

“This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques,” Razani said. “In other words, our study shows how and why dietary protein leads to the development of unstable plaques.”

Longer daily fasting times improve health and longevity (in mice)

The scientists randomly divided 292 male mice into two diet groups. One group received a naturally sourced diet that was lower in purified sugars and fat, and higher in protein and fiber than the other diet. The mice in each diet group were then divided into three sub-groups based on how often they had access to food. The first group of mice had access to food around the clock. A second group of mice was fed 30 percent less calories per day than the first group. The third group was meal fed, getting a single meal that added up to the exact number of calories as the round-the-clock group. Both the meal-fed and calorie-restricted mice learned to eat quickly when food was available, resulting in longer daily fasting periods for both groups.

The scientists tracked the mice’s metabolic health through their lifespans until their natural deaths and examined them post-mortem. Meal-fed and calorie-restricted mice showed improvements in overall health, as evidenced by delays in common age-related damage to the liver and other organs, and extended longevity. The calorie-restricted mice also showed significant improvement in fasting glucose and insulin levels compared to the other groups. Interestingly, the researchers found that diet composition had no significant impact on lifespan in the meal fed and calorie restricted groups.

Source article here.

One of my neighbors is a mouse researcher.  I bet he’s really excited this weekend.

The NIH webpage on caloric restriction and fasting diets is here.

Binge-eating mice reveal obesity clues

For example, when offered chocolate for just one hour per day, the animals will compulsively ‘binge’, consuming as much chocolate in one hour as they would over a whole day if it was continually available. They also showed inflexible behaviours, similar to those seen in addiction, choosing to wait for chocolate while ignoring freely available standard chow. Yet, at the same time, the chocolate did not seem to satiate hunger as well as regular food.

The team found that animals on the high fat or chocolate diet also changed their daily routines. They were more likely to eat during the daytime — mice are usually nocturnal and feed at night — and they ate shorter more frequent ‘snacks’ rather than larger, longer-spaced meals.

We had friends over for dinner on Saturday.  While at the store shopping for provisions I saw some gelato on sale for 99 cents.

$0.99!  The only flavor on sale was chocolate.  I bought some.

The next night I had to have some chocolate gelato.  Because it was there!

The mice have proven what I already know.

Read the source article here.

Diet Soda May Alter Our Gut Microbes And Raise The Risk Of Diabetes : The Salt : NPR

Now, a new study published in the journal Nature introduces a new idea: Diet sodas may alter our gut microbes in a way that increases the risk of metabolic diseases such as Type 2 diabetes — at least in some of us.

In the paper, researchers at the Weizmann Institute of Science in Israel describe what happened when they fed zero-calorie sweeteners, including saccharin, aspartame and sucralose, to mice.

“To our surprise, [the mice] developed glucose intolerance,” Weizmann researcher Eran Elinav tells us.

Artificial sweeteners induce glucose intolerance by altering the gut microbiota : Nature : Nature Publishing Group.

Diet Soda May Alter Our Gut Microbes And Raise The Risk Of Diabetes : The Salt : NPR.