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Arroyo, A. B.

Publications and source records attributed to Arroyo, A. B..

2 recordsLinked to original sources

Peds1 deficiency in zebrafish results in myeloid cell apoptosis and exacerbated inflammation

Plasmalogens are glycerophospholipids with a vinyl ether bond that confers unique properties. Recent identification of the gene encoding PEDS1, the desaturase generating the vinyl ether bond, enables evaluation of the role of plasmalogens in health and disease. Here, we report that Peds1-deficient zebrafish larvae display delayed development, increased basal inflammation, normal hematopoietic stem and progenitor cell emergence, and cell-autonomous myeloid cell apoptosis. In a sterile acute inflammation model, Peds1-deficient larvae exhibited impaired inflammation resolution and tissue regeneration, increased interleukin-1{beta} and NF-{kappa}B activities, and elevated ROS levels at the wound site. Abnormal immune cell recruitment, neutrophil persistence, and fewer but predominantly pro-inflammatory macrophages was observed. Chronic skin inflammation worsened in Peds1-deficient larvae but was mitigated by exogenous plasmalogen, which also alleviated hyper-susceptibility to bacterial infection, as did pharmacological inhibition of caspase-3 and colony-stimulating factor 3-induced myelopoiesis. Overall, our results highlight an important role for plasmalogens in myeloid cell biology and inflammation. KeypointsO_LIPlasmalogens are crucial for cell autonomous survival, recruitment and activation of neutrophils and macrophages. C_LIO_LIPlasmalogen production aids inflammation resolution, while supplementation reduces inflammation and boosts bacterial clearance. C_LI

immunology↗

A zebrafish model of COVID-19-associated cytokine storm syndrome reveals differential proinflammatory activities of Spike proteins of SARS-CoV-2 variants of concern.

The sudden and unexpected appearance of the COVID-19 pandemic turned the whole world upside down in a very short time. One of the main challenges faced has been to understand COVID-19 patient heterogeneity, as a minority develop life-threatening hyperinflammation, the so-called cytokine storm syndrome (CSS). Using the unique advantages of the zebrafish model we report here the proinflammatory role of Spike (S) proteins from different SARS-CoV-2 variants of concern after injection into the hindbrain ventricle, a cavity filled with cerebrospinal fluid to which immune cells can be easily recruited and that mimics the alveolar environment of the human lung. We found that wild type/Wuhan variant S1 (S1WT) protein promoted neutrophil and macrophage recruitment, local and systemic hyperinflammation, emergency myelopoiesis, and hemorrhages. In addition, S1{gamma} protein was more proinflammatory and S1{delta} was less proinflammatory than S1WT and, strikingly, S1{beta} promoted delayed and long-lasting inflammation. Pharmacological inhibition of the canonical inflammasome robustly alleviated S1 protein-induced inflammation and emergency myelopoiesis. In contrast, genetic inhibition of angiotensin-converting enzyme 2 strengthened the proinflammatory activity of S1, and the administration of angiopoietin (1-7) fully rescued S1-induced hyperinflammation and hemorrhages. These results shed light into the mechanisms orchestrating the COVID-19-associated CSS and the host immune response to different SARS-CoV-2 S protein variants. HighlightsO_LIS proteins of SARS-CoV-2 promote hyperinflammation, neutrophilia, monocytosis and hemorrhages in zebrafish. C_LIO_LIS protein effects in zebrafish are mediated via the canonical inflammasome and the Ace2/Angiopoietin (1-7) axis. C_LIO_LIDelta S1 is less proinflammatory than wild type S1 and fails to induce emergency myelopoiesis in zebrafish. C_LIO_LINaive and primed human white blood cells are unable to respond to S proteins. C_LI

immunology↗