ACBP: a poor-prognosis biomarker in sepsis and a target for disease mitigation [Lung]
Sepsis remains a major clinical challenge, with high mortality and long-term disability despite current interventions. Here, we identify the tissue hormone acyl-CoA–binding protein (ACBP), also known as diazepam-binding inhibitor (DBI), as a biomarker and driver of poor outcome in sepsis. ACBP/DBI was elevated in the plasma of septic patients and associated with organ dysfunction and increased mortality. In murine models of endotoxemia, Escherichia coli infection, and polymicrobial sepsis, genetic deletion or antibody-mediated neutralization of ACBP/DBI conferred robust protection by enhancing pathogen clearance, dampening cytokine storm, and preserving organ function. Notably, ACBP/DBI inhibition could be favorably combined with glucocorticoids, enhancing survival and reversing histopathological, transcriptional, or metabolic signatures of septic shock across heart, kidney, liver, lung, spleen, and plasma. These findings position ACBP/DBI as a mechanistic amplifier of sepsis pathophysiology and propose its neutralization, alone or in combination with corticosteroids, as a promising therapeutic strategy to interrupt the fatal trajectory of septic shock. Overall design: Eight-week-old male C57Bl/6J mice were randomly assigned to treatment groups and administered either a monoclonal antibody against ACBP/DBI (aDBI; 4h and 1h prior to surgery) or its isotype control (IgG), administered 1h before surgery. Sepsis was induced by cecal ligation and puncture (CLP) under isoflurane anesthesia. Briefly, the cecum was exteriorized, ligated at 75% of its length using non-absorbable 4-0 silk suture, and punctured once through-and-through with a 21-gauge needle. A small amount of fecal content was gently extruded, and the cecum was returned to the abdominal cavity. Sham-operated mice underwent the same procedure, including treatment injections, but without ligation or puncture. Mice that died within the first 24h post-surgery were considered to have succumbed to perioperative complications and were excluded from further analysis. For molecular analyses, organs were collected on the day of euthanasia (6h and 24h post-CLP) and immediately snap-frozen in liquid nitrogen. For RNA-sequencing library preparation, RNA was extracted from mouse lungs using RNA Plus Mini Kit (Qiagen) according to manufacturer's instructions. The concentration and integrity of total RNA was analysed using electrophoretic separation on microfabricated chips in Agilent 2100 Bioanalyzer System (Agilent, CA, USA). After, mRNA-sequencing library preparation (1.5 µg total RNA per sample) was carried out on NovaSeq 6000 PE150 instrument (2 x 150 bp, 40 million reads per sample). For RNA-sequencing data analysis, Fastq files were align on mm10, Mus musculus genome, by Hisat2, BAM files were count by HTSeq-count. The obtained raw count files were analyse with R package (R Foundation for Statistical Computing; https://www.R-project.org/) DESeq2. Our genes of interest were selected based on the thresholds abs (Fold Change) = 1.5 and a pvalue = 0.05. Heatmaps were performed with the R package ComplexHeatmap, Venn diagrams with ggVennDiagram, all other plots are realized with ggplot2. Gene ontology was realized with gprofilr, clusterProfiler and enrichplot.