Two items relevant to long COVID

One of the tricky issues in studying in long COVID is: how widely do researchers cast their net? Initial reports acknowledged that people who were hospitalized and in intensive care may take a while to get back on their feet. But the number of people who had SARS-CoV-2 infections and were NOT hospitalized, yet experienced lingering symptoms, may be greater. A recent report from the United Kingdom, published in PLOS Medicine, studied more than Read more

All your environmental chemicals belong in the exposome

Emory team wanted to develop a standard low-volume approach that would avoid multiple processing steps, which can lead to loss of material, variable recovery, and the potential for Read more

Signature of success for an HIV vaccine?

Efforts to produce a vaccine against HIV/AIDS have been sustained for more than a decade by a single, modest success: the RV144 clinical trial in Thailand, whose results were reported in 2009. Now Emory, Harvard and Case Western Reserve scientists have identified a gene activity signature that may explain why the vaccine regimen in the RV144 study was protective in some individuals, while other HIV vaccine studies were not successful. The researchers think that this signature, Read more

amyloid

Anti-TNF vs Alzheimer’s mouse model

An experimental anti-inflammatory drug has positive effects on neuron function and amyloid plaques in a mouse model of Alzheimer’s disease, Emory neuroscientists report. The findings are published in the journal Neurobiology of Disease.

Inflammation’s presence in Alzheimer’s is well established, but it is usually thought of as an accelerator, rather than an initiating cause. While everybody argues about the amyloid hypothesis, there’s a case to be made for intervening against the inflammation. Exactly how is an open question.

The drug tested, called XPro1595, targets the inflammatory signaling molecule tumor necrosis factor (TNF). Commercialized drugs such as etanercept and infliximab, used to treat autoimmune diseases, also block TNF. However, XPro1595 only interferes with the soluble form of TNF and is supposed to have less of an effect on overall immune function.

Senior author Malu Tansey (pictured) and her colleagues say that interfering with TNF could have direct effects on neurons, as well as indirect effects on the immune cells infiltrating the brain. They write that “the most promising finding in our study” is the ability of XPro1595 to restore long-term potentiation or LTP, which is impaired in the Alzheimer’s model mice. Read more

Posted on by Quinn Eastman in Immunology, Neuro Leave a comment

Provocative prions may protect yeast cells from stress

Prions have a notorious reputation. They cause neurodegenerative disease, namely mad cow/Creutzfeld-Jakob disease. And the way these protein particles propagate – getting other proteins to join the pile – can seem insidious.

Yet prion formation could represent a protective response to stress, research from Emory University School of Medicine and Georgia Tech suggests.

A yeast protein called Lsb2, which can trigger prion formation by other proteins, actually forms a “metastable” prion itself in response to elevated temperatures, the scientists report.

The results were published this week in Cell Reports.

Higher temperatures cause proteins to unfold; this is a major stress for yeast cells as well as animal cells, and triggers a “heat shock” response. Prion formation could be an attempt by cells to impose order upon an otherwise chaotic jumble of misfolded proteins, the scientists propose.

A glowing red clump can be detected in yeast cells containing a Lsb2 prion (left), because Lsb2 is hooked up to a red fluorescent protein. In other cells lacking prion activity (right), the Lsb2 fusion protein is diffuse.

“What we found suggests that Lsb2 could be the regulator of a broader prion-forming response to stress,” says Keith Wilkinson, PhD, professor of biochemistry at Emory University School of Medicine.

The scientists call the Lsb2 prion metastable because it is maintained in a fraction of cells after they return to normal conditions but is lost in other cells. Lsb2 is a short-lived, unstable protein, and mutations that keep it around longer increase the stability of the prions.

The Cell Reports paper was the result of collaboration between Wilkinson, Emory colleague Tatiana Chernova, PhD, assistant professor of biochemistry, and the laboratory of Yury Chernoff, PhD in Georgia Tech’s School of Biological Sciences.

“It’s fascinating that stress treatment may trigger a cascade of prion-like changes, and that the molecular memory of that stress can persist for a number of cell generations in a prion-like form,” Chernoff says.”Our further work is going to check if other proteins can respond to environmental stresses in a manner similar to Lsb2.” Read more

Posted on by Quinn Eastman in Uncategorized Leave a comment

BioArt: amyloid in the heart

What Abstract Expressionist artist painted this? Jackson Pollock?LewisW2013

Actually, the photo depicts amyloid plaques, a frequent topic in the context of Alzheimer’s disease. Pathologist William Lewis‘ photo reminds us that amyloid can also appear in the heart.

Amyloidosis of the heart is a set of complex diseases caused by the accumulation of cellular proteins that form an amyloid plaque. Although http://www.oakleyonorder.com/ amyloidosis was described more than 100 years ago, the causative proteins were not identified until recent chemical analyses were conducted. This image shows an amyloid plaque stained with Congo red stain and viewed through a polarized lens. The optical properties of the amyloid-forming protein cause it to appear green, while other matrix materials within the plaque appear as orange and blue.

The photo, which was one of the winners of the FASEB (Federation of American Societies for Experimental Biology) 2013 BioArt competition, was featured on NIH director Francis Collins’ blog this week.

Lewis, who studies the effects of antiretroviral drugs on the cardiovascular system in his laboratory, reports that he came across the amyloid tissue sample as part of his duties as director of cardiovascular pathology: “It was beautiful.”

Posted on by Quinn Eastman in Heart Leave a comment