Biology subjects

Guijarro, A.

Publications and source records attributed to Guijarro, A..

3 recordsLinked to original sources

bioRxiv2025

The inflammasome adaptor protein ASC triggers immunometabolic dysregulation induced by dysbiosis during obesity

The inflammasomes are a component of the innate immune system that induce inflammation after activation by danger and pathogen signals, this process is of extreme importance in the gut, where high-saturated fat diets modulate inflammasome activity resulting in dysbiosis and inflammation. In this work, we found that the common inflammasome adaptor protein, apoptosis speck-like protein with a caspase activation domain (ASC), is essential for the development of metabolic dysregulation during high fat diet. ASC-deficient mice (Pycard-/-) presented lower weight gain and improved glucose tolerance, enhancing metabolism, and reducing inflammation in both intestine and liver. The extracellular administration of ASC oligomers to Pycard-/- mice partially rescued dysbiosis, intestinal metabolism and inflammation. Therefore, ASC presents intracellular functions activating the inflammasome, as well as extracellular function as an oligomer during metabolic dysregulation, emerging ASC as a potential drug target beneficial to treat obesity and metabolism-associated liver diseases.

immunology↗

bioRxiv2024

Gasdermin D mediates a fast transient release of ATP after NLRP3 inflammasome activation before ninjurin 1-induced lytic cell death

Pyroptosis is a lytic cell death triggered by the cleavage of gasdermin (GSDM) proteins and subsequent pore formation by the N-terminal domain oligomerization in the plasma membrane. GSDMD is cleaved by caspase-1/-4/-5/-11 upon inflammasome activation and mediates IL-1{beta} and IL-18 release. GSDMD pores favors ninjurin-1 (NINJ1) induced plasma membrane rupture and cell death. Here, we demonstrate that GSDMD mediates early ATP release upon NLRP3 inflammasome activation independently of NINJ1, occurring before IL-1{beta} release and cell death and constituting an early danger signal. The release of ATP is a transient signal terminated before the cells continue to permeabilize and die. The different N-terminal of GSDMA to E are also able to release ATP and induce monocyte migration towards pyroptotic cells. This study reveals ATP release as an early, and transient danger signal depending on GSDMD plasma membrane permeabilization, independently of the late stages of lytic cell death.

immunology↗

bioRxiv2019

MYC-associated factor MAX is an essential regulator of the clock core network

The circadian transcriptional network is based on a competition between transcriptional activator and repressor complexes regulating the rhythmic expression of clock-controlled genes. We show here that the MYC-Associated factor X, MAX, plays a repressive role in this network and operates through its MYC-independent binding to E-box-containing regulatory regions within the promoters of circadian BMAL1 targets. This clock function of MAX is essential for maintaining a proper circadian rhythm but separated by the role of MAX as a partner of MYC in controlling cell proliferation. We also identified MAX Network Transcriptional repressor, MNT, as a fundamental partner of MAX-mediated circadian regulation. Collectively, our data indicate that MAX is an integral part of the core molecular clock and keeps the balance between positive and negative elements of the molecular clock machinery. Accordingly, alteration of MAX transcriptional complexes may contribute to circadian dysfunction in pathological contexts.

molecular biology↗