Chronic kidney disease leads to microglial potassium efflux and inflammasome activation in the brain.

Cognitive impairment is common in extracerebral diseases such as chronic kidney disease (CKD). Kidney transplantation reverses cognitive impairment, indicating that cognitive impairment driven by CKD is therapeutically amendable. However, we lack mechanistic insights allowing development of targeted therapies. Using a combination of mouse models (including mice with neuron-specific IL-1R1 deficiency), single cell analyses (single-nuclei RNA-sequencing and single-cell thallium autometallography), human samples and in vitro experiments we demonstrate that microglia activation impairs neuronal potassium homeostasis and cognition in CKD. CKD disrupts the barrier of brain endothelial cells in vitro and the blood-brain barrier in vivo, establishing that the uremic state modifies vascular permeability in the brain. Exposure to uremic conditions impairs calcium homeostasis in microglia, enhances microglial potassium efflux via the calcium-dependent channel KCa3.1, and induces p38-MAPK associated IL-1ß maturation in microglia. Restoring potassium homeostasis in microglia using a KCa3.1-specific inhibitor (TRAM34) improves CKD-triggered cognitive impairment. Likewise, inhibition of the IL-1ß receptor 1 (IL-1R1) using anakinra or genetically abolishing neuronal IL-1R1 expression in neurons prevent CKD-mediated reduced neuronal potassium turnover and CKD-induced impaired cognition. Accordingly, in CKD mice, impaired cognition can be ameliorated by either preventing microglia activation or inhibiting IL-1R-signaling in neurons. Thus, our data suggest that potassium efflux from microglia triggers their activation, which promotes microglia IL-1ß release and IL-1R1-mediated neuronal dysfunction in CKD. Hence, our study provides new mechanistic insight into cognitive impairment in association with CKD and identifies possible new therapeutic approaches.

Variant Arterial Supply of the Descending Colon by the Coeliac Trunk: A Case Report.

Background and Objectives: Knowledge of arterial variations of the intestines is of great importance in visceral surgery and interventional radiology. Materials and Methods: An unusual variation in the blood supply of the descending colon was observed in a Caucasian female body donor. Results: In this case, the left colic artery that regularly derives from the inferior mesenteric artery supplying the descending colon was instead a branch of the common hepatic artery. Conclusions: Here, we describe the very rare case of an aberrant left colic artery arising from the common hepatic artery in a dissection study.