GENETIC DELETION OF TRANSLOCATOR PROTEIN EXACERBATES POST-SEPSIS SYNDROME WITH ACTIVATION OF THE C1Q PATHWAY IN SEPTIC MOUSE MODEL

Shock. 2023 Jan 1;59(1):82-90. doi: 10.1097/SHK.0000000000002030. Epub 2022 Nov 3.

Abstract

Significant numbers of patients who survive sepsis exhibit psychiatric and cognitive impairments, termed post-sepsis syndrome. Understanding the underlying pathophysiology is essential to develop effective therapies. Translocator protein 18 kDa (TSPO) is a multifaceted mitochondrial protein implicated in inflammation, oxidative stress, and steroidogenesis in the central nervous system. Despite accumulated evidence demonstrating TSPO is a biomarker in psychiatric and neurodegenerative disorders, the role of this protein in post-sepsis syndrome remains elusive. The aim of this study was to investigate the role of TSPO in the long-term impairment of mouse behavior associated with psychiatric and cognitive impairments following sepsis induced by cecal ligation and puncture (CLP) surgery. Animals were divided into three groups: (i) wild type (WT) + sham, (ii) WT + CLP, and (iii) TSPO knock out + CLP. Survival rate and body weight change were assessed up to 17 days after surgeries. Then, we also assessed anxiety-like behavior, depression-like behavior, cognitive function, locomotor activity, and forelimb muscle strength in surviving mice by elevated plus maze, tail suspension test, y-maze, open field test, and grip strength test, respectively. Deletion of the TSPO gene led to high mortality and prolonged weight loss and exacerbated anxiety-like and depressive-like behavior with cognitive impairment 17 days after, but not before, CLP surgery. RNA-seq analysis of the hippocampus revealed the upregulation of genes (C1qb, C1qc, and Tyrobp) in C1q complement pathways correlated significantly with anxiety-like behavior that appeared long after CLP surgery. The expressions of these genes predicted other behavioral traits, including depressive-like behavior in the tail suspension test and grip power impairment, supporting the role of the C1q pathway in post-sepsis syndrome. Because the C1q pathway has recently attracted interest as a tag for pathological synaptic elimination, the current study suggests the C1q pathway is involved in the psychiatric and cognitive impairments observed in post-sepsis syndrome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anxiety / genetics
  • Cognitive Dysfunction* / genetics
  • Complement C1q*
  • Inflammation / etiology
  • Mice
  • Receptors, GABA* / genetics
  • Sepsis* / complications
  • Sepsis* / genetics
  • Sepsis* / metabolism

Substances

  • Complement C1q
  • Bzrp protein, mouse
  • Receptors, GABA