Evidence of Structural Protein Damage and Membrane Lipid Remodeling in Red Blood Cells from COVID-19 Patients, 2020, Thomas et al

[Jim001]

Both red blood cells damage and kynurine identified in LongCovid research

https://news.cuanschutz.edu/news-st...1b-VxUN-n6F55E6dMVcMwGkMR-huuW-wbi8mEvqTNJt-s

"The virus didn’t affect the cells’ hemoglobin, which allow the cells to pick up oxygen, but it did damage membrane proteins responsible for blood cell structure, a characteristic that allows these cells to indirectly regulate red cell capacity to release oxygen and, most importantly, to squeeze through narrow capillaries in the periphery of the bloodstream."

"researchers discovered they can measure kynurenine and predict future severity of a disease case"

 

[rvallee]

 

[Hutan]

This is the red blood cell paper referred to in the article:

Evidence of Structural Protein Damage and Membrane Lipid Remodeling in Red Blood Cells from COVID-19 Patients
https://pubs.acs.org/doi/10.1021/acs.jproteome.0c00606

Abstract

The SARS-CoV-2 beta coronavirus is the etiological driver of COVID-19 disease, which is primarily characterized by shortness of breath, persistent dry cough, and fever. Because they transport oxygen, red blood cells (RBCs) may play a role in the severity of hypoxemia in COVID-19 patients. The present study combines state-of-the-art metabolomics, proteomics, and lipidomics approaches to investigate the impact of COVID-19 on RBCs from 23 healthy subjects and 29 molecularly diagnosed COVID-19 patients.

RBCs from COVID-19 patients had increased levels of glycolytic intermediates, accompanied by oxidation and fragmentation of ankyrin, spectrin beta, and the N-terminal cytosolic domain of band 3 (AE1). Significantly altered lipid metabolism was also observed, in particular, short- and medium-chain saturated fatty acids, acyl-carnitines, and sphingolipids. Nonetheless, there were no alterations of clinical hematological parameters, such as RBC count, hematocrit, or mean corpuscular hemoglobin concentration, with only minor increases in mean corpuscular volume.

Taken together, these results suggest a significant impact of SARS-CoV-2 infection on RBC structural membrane homeostasis at the protein and lipid levels. Increases in RBC glycolytic metabolites are consistent with a theoretically improved capacity of hemoglobin to off-load oxygen as a function of allosteric modulation by high-energy phosphate compounds, perhaps to counteract COVID-19-induced hypoxia.

Conversely, because the N-terminus of AE1 stabilizes deoxyhemoglobin and finely tunes oxygen off-loading and metabolic rewiring toward the hexose monophosphate shunt, RBCs from COVID-19 patients may be less capable of responding to environmental variations in hemoglobin oxygen saturation/oxidant stress when traveling from the lungs to peripheral capillaries and vice versa.

 

[Hutan]

The article is readable and interesting.

It's not exactly clear that the researcher mentioned in the article has yet recovered, although he is attributing his ongoing effects first to damage to his red blood cells (which should be corrected when there are new red blood cells) and now inflammation in the lungs, rather than ME/CFS. He'd be a handy researcher to have working on ME/CFS.

SARS-CoV-2 left D’Alessandro, an associate professor, Boettcher investigator and metabolomics researcher, quite ill for a couple weeks in March. It lingered in his upper respiratory tract and re-flared in early fall in combination with the wildfire smoke.
D’Alessandro, director of the Metabolomics Core of the University of Colorado School of Medicine’s Department of Biochemistry and Molecular Genetics and CU Cancer Center member, is young, 36,

This explains why D’Alessandro, who jumped back into training for a late-summer marathon, noticed that more than a month after his initial COVID bout – two subsequent tests came out negative – he felt extremely tired just 20 minutes into a run.

It took D’Alessandro two full months before he felt 100% again. He returned to marathon training in May. But COVID-19 wasn’t done with him, especially in combination with the historic wildfires and subsequent air-particulate clouds in early fall. “Unfortunately, with my personal case, COVID can leave you with some long-term effects, like issues with the respiratory tract above the lungs,” he said. “You can have some inflammation of your airways. I’ve been dealing with that on and off in September and October … when we had the fires. I had two terrible months. I’m finally getting better now.”

Kynurine is mentioned in relation to a forthcoming study:

A forthcoming study from the group focuses on the inflammatory response to viruses called the kynurenine response. Because the molecule correlates to disease severity, researchers discovered they can measure kynurenine and predict future severity of a disease case – SARS-CoV-2, for instance – and whether a patient will develop severe thrombolic complications, such as dangerous blood clots.