Aberrant differentiation of epithelial progenitors is accompanied by a hypoxic microenvironment in the paraquat-injured human lung

Sensing of mitochondrial DNA by ZBP1 promotes RIPK3-mediated necroptosis and ferroptosis in response to diquat poisoning

Diquat (DQ) poisoning is a severe medical condition associated with life-threatening implications and multiorgan dysfunction. Despite its clinical significance, the precise underlying mechanism remains inadequately understood. This study elucidates that DQ induces instability in the mitochondrial genome of endothelial cells, resulting in the accumulation of Z-form DNA. This process activates Z-DNA binding protein 1 (ZBP1), which then interacts with receptor-interacting protein kinase 3 (RIPK3), ultimately leading to RIPK3-dependent necroptotic and ferroptotic signaling cascades. Specific deletion of either Zbp1 or Ripk3 in endothelial cells simultaneously inhibits both necroptosis and ferroptosis. This dual inhibition significantly reduces organ damage and lowers mortality rate. Notably, our investigation reveals that RIPK3 has a dual role. It not only phosphorylates MLKL to induce necroptosis but also phosphorylates FSP1 to inhibit its enzymatic activity, promoting ferroptosis. The study further shows that deletion of mixed lineage kinase domain-like (Mlkl) and the augmentation of ferroptosis suppressor protein 1 (FSP1)-dependent non-canonical vitamin K cycling can provide partial protection against DQ-induced organ damage. Combining Mlkl deletion with vitamin K treatment demonstrates a heightened efficacy in ameliorating multiorgan damage and lethality induced by DQ. Taken together, this study identifies ZBP1 as a crucial sensor for DQ-induced mitochondrial Z-form DNA, initiating RIPK3-dependent necroptosis and ferroptosis. These findings suggest that targeting the ZBP1/RIPK3-dependent necroptotic and ferroptotic pathways could be a promising approach for drug interventions aimed at mitigating the adverse consequences of DQ poisoning.

Utilizing symmetrical tetramethyl cucurbit[6]uril-based supramolecular fluorescence probe for detection of paraquat in water

A supramolecular fluorescence probe has been developed using a symmetrical tetramethyl cucurbit[6]uril (TMeQ[6]) and a styryl derivative (SPy) with a host-guest ratio of 2:1. The introduction of paraquat (PQ) competes with SPy for the TMeQ[6] cavity, resulting in fluorescent quenching. The addition of 17 common herbicides and ions had negligible effects on the fluorescence quenching, indicating that the 2TMeQ[6]/SPy complex exhibits excellent selectivity in detecting PQ. The detection limit was found to be 4.62 × 10-7 M. More importantly, the probe was engineered to detect paraquat in river water by examining post-treatment samples and noting alterations in fluorescence color. The red to blue (R/B) intensity ratio is subsequently calculated to ascertain the PQ concentration. Experimental trials conducted on river water samples yielded recovery rates between 98.21 % and 108 %, with a relative standard deviation of less than 5 %. By pairing this with a smartphone-based colorimetric analysis application, we can facilitate portable PQ detection, enabling efficient and convenient monitoring across various locations.