Biology subjects

Uranga, I.

Publications and source records attributed to Uranga, I..

2 recordsLinked to original sources

bioRxiv2022

Cleavage of cFLIP restrains cell death during viral infection and tissue injury and favors tissue repair

Cell death coordinates repair programs following pathogen attack and tissue injury. However, aberrant cell death can interfere with such programs and cause organ failure. cFLIP is a crucial regulator of cell death and a substrate of Caspase-8. Yet, the physiological role of cFLIP cleavage by Caspase-8 remains elusive. Here, we discovered an essential role for cFLIP cleavage in restraining cell death in different pathophysiological scenarios. Mice expressing a cleavage-resistant cFLIP mutant, CflipD377A, exhibited increased sensitivity to SARS-CoV-induced lethality, impaired skin wound healing and increased tissue damage caused by Sharpin deficiency. In vitro, abrogation of cFLIP cleavage sensitizes cells to TNF-induced necroptosis and apoptosis by favoring complex-II formation. Mechanistically, the cell death-sensitizing effect of the D377A mutation depends on Gln(Q)469. These results reveal a crucial role for cFLIP cleavage in controlling the amplitude of cell death responses occurring upon tissue stress, to ensure the execution of repair programs.

cell biology↗

bioRxiv2020

Granzyme A inhibition reduces inflammation and increases survival during abdominal sepsis.

Sepsis is a serious syndrome characterised by a dysregulated systemic inflammatory response. Here we have analysed the role and the therapeutic potential of Granzyme A (GzmA) in the pathogenesis of peritoneal sepsis using the Cecal Ligation and Puncture (CLP) polymicrobial sepsis model and samples from humans undergoing abdominal sepsis. Elevated GzmA was observed in serum from patients with abdominal sepsis suggesting that GzmA plays an important role in this pathology. In the CLP model GzmA deficient mice, or WT mice treated with an extracellular GzmA inhibitor, showed increased survival, which correlated with a reduction in proinflammatory markers in both serum and peritoneal lavage fluid. GzmA deficiency did not influence bacterial load in blood and spleen indicating that GzmA has no role in bacterial control. Mechanistically, we found that extracellular active GzmA acts as a proinflammatory mediator in macrophages by inducing the TLR4-dependent expression of IL-6 and TNF. Our findings implicate GzmA as a key regulator of the inflammatory response during abdominal sepsis, and suggest that it could be targeted for treatment of this severe pathology.

immunology↗