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Glycans in the SARS-CoV-2 spike protein play active role in infection

Glycans in the SARS-CoV-2 spike protein play active role in infection

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Credit: Adapted from ACS Central Science 2020, DOI: 10.1021/acscentsci.0c01056

As the COVID-19 pandemic rages on, researchers are working overtime to develop vaccines and therapies to thwart SARS-CoV-2, the virus responsible for the disease Many efforts focus on the coronavirus spike protein, which binds the angiotensin-converting enzyme 2 (ACE2) on human cells to allow viral entry. Now, researchers reporting in ACS Central Science have uncovered an active role for glycans — sugar molecules that can decorate proteins — in this process, suggesting targets for vaccines and therapies.

Before the SARS-CoV-2 spike protein can interact with ACE2 on a human cell, it changes shape to expose its receptor binding domain (RBD), the part of the protein that interacts with ACE2. Like many viral proteins, the SARS-CoV-2 spike protein has a thick coat of glycans on its surface. These glycans, which are attached at specific sites, help shield the viral proteins from the host immune system. Rommie Amaro and colleagues at University of California San Diego, Maynooth University (Ireland) and the University of Texas at Austin wondered whether certain glycans in the SARS-CoV-2 spike protein might also be active players in the process leading to infection.

To find out, the researchers used structural and glycomic data to build molecular dynamics simulations of the SARS-CoV-2 spike protein embedded in the viral membrane. The computer models, which presented a detailed snapshot of every atom in the spike glycoprotein, revealed that N-glycans linked to the spike protein at certain sites (N165 and N234) helped stabilize the shape change that exposes the RBD, which could help promote infection. The simulations also identified regions of the spike protein that weren’t coated by glycans and thus could be vulnerable to antibodies, especially after the shape change. In laboratory experiments using biolayer interferometry, the team showed that mutating the spike protein so that it no longer had glycans at N165 and N234 reduced binding to ACE2. These results lay the foundation for new strategies to fight the pandemic threat, the researchers say.

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The authors acknowledge funding from the National Institutes of Health, the National Science Foundation, the Research Corporation for Science Advancement, UC San Diego Moores Cancer Center, the Irish Research Council, and the Visible Molecular Cell Consortium.

The paper’s abstract will be available on September 23 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acscentsci.0c01056

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate…

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate iron levels in their blood due to a COVID-19 infection could be at greater risk of long COVID.

(Shutterstock)

A new study indicates that problems with iron levels in the bloodstream likely trigger chronic inflammation and other conditions associated with the post-COVID phenomenon. The findings, published on March 1 in Nature Immunology, could offer new ways to treat or prevent the condition.

Long COVID Patients Have Low Iron Levels

Researchers at the University of Cambridge pinpointed low iron as a potential link to long-COVID symptoms thanks to a study they initiated shortly after the start of the pandemic. They recruited people who tested positive for the virus to provide blood samples for analysis over a year, which allowed the researchers to look for post-infection changes in the blood. The researchers looked at 214 samples and found that 45 percent of patients reported symptoms of long COVID that lasted between three and 10 months.

In analyzing the blood samples, the research team noticed that people experiencing long COVID had low iron levels, contributing to anemia and low red blood cell production, just two weeks after they were diagnosed with COVID-19. This was true for patients regardless of age, sex, or the initial severity of their infection.

According to one of the study co-authors, the removal of iron from the bloodstream is a natural process and defense mechanism of the body.

But it can jeopardize a person’s recovery.

When the body has an infection, it responds by removing iron from the bloodstream. This protects us from potentially lethal bacteria that capture the iron in the bloodstream and grow rapidly. It’s an evolutionary response that redistributes iron in the body, and the blood plasma becomes an iron desert,” University of Oxford professor Hal Drakesmith said in a press release. “However, if this goes on for a long time, there is less iron for red blood cells, so oxygen is transported less efficiently affecting metabolism and energy production, and for white blood cells, which need iron to work properly. The protective mechanism ends up becoming a problem.”

The research team believes that consistently low iron levels could explain why individuals with long COVID continue to experience fatigue and difficulty exercising. As such, the researchers suggested iron supplementation to help regulate and prevent the often debilitating symptoms associated with long COVID.

It isn’t necessarily the case that individuals don’t have enough iron in their body, it’s just that it’s trapped in the wrong place,” Aimee Hanson, a postdoctoral researcher at the University of Cambridge who worked on the study, said in the press release. “What we need is a way to remobilize the iron and pull it back into the bloodstream, where it becomes more useful to the red blood cells.”

The research team pointed out that iron supplementation isn’t always straightforward. Achieving the right level of iron varies from person to person. Too much iron can cause stomach issues, ranging from constipation, nausea, and abdominal pain to gastritis and gastric lesions.

1 in 5 Still Affected by Long COVID

COVID-19 has affected nearly 40 percent of Americans, with one in five of those still suffering from symptoms of long COVID, according to the U.S. Centers for Disease Control and Prevention (CDC). Long COVID is marked by health issues that continue at least four weeks after an individual was initially diagnosed with COVID-19. Symptoms can last for days, weeks, months, or years and may include fatigue, cough or chest pain, headache, brain fog, depression or anxiety, digestive issues, and joint or muscle pain.

Tyler Durden Sat, 03/09/2024 - 12:50

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Walmart joins Costco in sharing key pricing news

The massive retailers have both shared information that some retailers keep very close to the vest.

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As we head toward a presidential election, the presumed candidates for both parties will look for issues that rally undecided voters. 

The economy will be a key issue, with Democrats pointing to job creation and lowering prices while Republicans will cite the layoffs at Big Tech companies, high housing prices, and of course, sticky inflation.

The covid pandemic created a perfect storm for inflation and higher prices. It became harder to get many items because people getting sick slowed down, or even stopped, production at some factories.

Related: Popular mall retailer shuts down abruptly after bankruptcy filing

It was also a period where demand increased while shipping, trucking and delivery systems were all strained or thrown out of whack. The combination led to product shortages and higher prices.

You might have gone to the grocery store and not been able to buy your favorite paper towel brand or find toilet paper at all. That happened partly because of the supply chain and partly due to increased demand, but at the end of the day, it led to higher prices, which some consumers blamed on President Joe Biden's administration.

Biden, of course, was blamed for the price increases, but as inflation has dropped and grocery prices have fallen, few companies have been up front about it. That's probably not a political choice in most cases. Instead, some companies have chosen to lower prices more slowly than they raised them.

However, two major retailers, Walmart (WMT) and Costco, have been very honest about inflation. Walmart Chief Executive Doug McMillon's most recent comments validate what Biden's administration has been saying about the state of the economy. And they contrast with the economic picture being painted by Republicans who support their presumptive nominee, Donald Trump.

Walmart has seen inflation drop in many key areas.

Image source: Joe Raedle/Getty Images

Walmart sees lower prices

McMillon does not talk about lower prices to make a political statement. He's communicating with customers and potential customers through the analysts who cover the company's quarterly-earnings calls.

During Walmart's fiscal-fourth-quarter-earnings call, McMillon was clear that prices are going down.

"I'm excited about the omnichannel net promoter score trends the team is driving. Across countries, we continue to see a customer that's resilient but looking for value. As always, we're working hard to deliver that for them, including through our rollbacks on food pricing in Walmart U.S. Those were up significantly in Q4 versus last year, following a big increase in Q3," he said.

He was specific about where the chain has seen prices go down.

"Our general merchandise prices are lower than a year ago and even two years ago in some categories, which means our customers are finding value in areas like apparel and hard lines," he said. "In food, prices are lower than a year ago in places like eggs, apples, and deli snacks, but higher in other places like asparagus and blackberries."

McMillon said that in other areas prices were still up but have been falling.

"Dry grocery and consumables categories like paper goods and cleaning supplies are up mid-single digits versus last year and high teens versus two years ago. Private-brand penetration is up in many of the countries where we operate, including the United States," he said.

Costco sees almost no inflation impact

McMillon avoided the word inflation in his comments. Costco  (COST)  Chief Financial Officer Richard Galanti, who steps down on March 15, has been very transparent on the topic.

The CFO commented on inflation during his company's fiscal-first-quarter-earnings call.

"Most recently, in the last fourth-quarter discussion, we had estimated that year-over-year inflation was in the 1% to 2% range. Our estimate for the quarter just ended, that inflation was in the 0% to 1% range," he said.

Galanti made clear that inflation (and even deflation) varied by category.

"A bigger deflation in some big and bulky items like furniture sets due to lower freight costs year over year, as well as on things like domestics, bulky lower-priced items, again, where the freight cost is significant. Some deflationary items were as much as 20% to 30% and, again, mostly freight-related," he added.

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Walmart has really good news for shoppers (and Joe Biden)

The giant retailer joins Costco in making a statement that has political overtones, even if that’s not the intent.

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As we head toward a presidential election, the presumed candidates for both parties will look for issues that rally undecided voters. 

The economy will be a key issue, with Democrats pointing to job creation and lowering prices while Republicans will cite the layoffs at Big Tech companies, high housing prices, and of course, sticky inflation.

The covid pandemic created a perfect storm for inflation and higher prices. It became harder to get many items because people getting sick slowed down, or even stopped, production at some factories.

Related: Popular mall retailer shuts down abruptly after bankruptcy filing

It was also a period where demand increased while shipping, trucking and delivery systems were all strained or thrown out of whack. The combination led to product shortages and higher prices.

You might have gone to the grocery store and not been able to buy your favorite paper towel brand or find toilet paper at all. That happened partly because of the supply chain and partly due to increased demand, but at the end of the day, it led to higher prices, which some consumers blamed on President Joe Biden's administration.

Biden, of course, was blamed for the price increases, but as inflation has dropped and grocery prices have fallen, few companies have been up front about it. That's probably not a political choice in most cases. Instead, some companies have chosen to lower prices more slowly than they raised them.

However, two major retailers, Walmart (WMT) and Costco, have been very honest about inflation. Walmart Chief Executive Doug McMillon's most recent comments validate what Biden's administration has been saying about the state of the economy. And they contrast with the economic picture being painted by Republicans who support their presumptive nominee, Donald Trump.

Walmart has seen inflation drop in many key areas.

Image source: Joe Raedle/Getty Images

Walmart sees lower prices

McMillon does not talk about lower prices to make a political statement. He's communicating with customers and potential customers through the analysts who cover the company's quarterly-earnings calls.

During Walmart's fiscal-fourth-quarter-earnings call, McMillon was clear that prices are going down.

"I'm excited about the omnichannel net promoter score trends the team is driving. Across countries, we continue to see a customer that's resilient but looking for value. As always, we're working hard to deliver that for them, including through our rollbacks on food pricing in Walmart U.S. Those were up significantly in Q4 versus last year, following a big increase in Q3," he said.

He was specific about where the chain has seen prices go down.

"Our general merchandise prices are lower than a year ago and even two years ago in some categories, which means our customers are finding value in areas like apparel and hard lines," he said. "In food, prices are lower than a year ago in places like eggs, apples, and deli snacks, but higher in other places like asparagus and blackberries."

McMillon said that in other areas prices were still up but have been falling.

"Dry grocery and consumables categories like paper goods and cleaning supplies are up mid-single digits versus last year and high teens versus two years ago. Private-brand penetration is up in many of the countries where we operate, including the United States," he said.

Costco sees almost no inflation impact

McMillon avoided the word inflation in his comments. Costco  (COST)  Chief Financial Officer Richard Galanti, who steps down on March 15, has been very transparent on the topic.

The CFO commented on inflation during his company's fiscal-first-quarter-earnings call.

"Most recently, in the last fourth-quarter discussion, we had estimated that year-over-year inflation was in the 1% to 2% range. Our estimate for the quarter just ended, that inflation was in the 0% to 1% range," he said.

Galanti made clear that inflation (and even deflation) varied by category.

"A bigger deflation in some big and bulky items like furniture sets due to lower freight costs year over year, as well as on things like domestics, bulky lower-priced items, again, where the freight cost is significant. Some deflationary items were as much as 20% to 30% and, again, mostly freight-related," he added.

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