Dendrobine alleviates lung injury in septic mice by inhibiting mitochondrial-endoplasmic reticulum crosstalk-mediated NLRP3 inflammasome activation.

Sepsis, a life-threatening disorder driven by a dysregulated host response to infection, is frequently accompanied by acute lung injury (ALI), worsening disease severity, and mortality. Excessive macrophage-mediated inflammation is central to its pathogenesis. Given emerging evidence that mitochondria-endoplasmic reticulum (ER) crosstalk drives inflammatory injury, we investigated whether modulating this interaction could mitigate sepsis-induced damage. Using LPS-stimulated THP-1 macrophages and a murine model of LPS-induced sepsis, we evaluated the anti-inflammatory and organ-protective effects of dendrobine, a bioactive alkaloid from Dendrobium nobile Lindl. Dendrobine suppressed glycolysis-induced mitochondria-ER crosstalk, thereby reducing macrophage-driven inflammation and tissue injury. In vivo, dendrobine lowered circulating interleukin (IL)-1β and IL-18 levels and alleviated ALI. Mechanistically, dendrobine decreased reactive oxygen species production and mitochondrial DNA (mtDNA) release, leading to downregulation of NLRP3 and cleaved caspase-1. These effects stemmed from inhibition of hypoxia-inducible factor-1α (HIF-1α) and hexokinase 2 (HK2)-mediated glycolysis, preventing HK2 dissociation from voltage-dependent anion channel 1 (VDAC1) and disrupting IP3R-GRP75-VDAC1 complex formation. Collectively, these findings demonstrate that dendrobine protects against sepsis-induced organ injury by targeting the IP3R-GRP75-VDAC1-HK2 axis in macrophages, highlighting its therapeutic potential for sepsis.