Ontology highlight
ABSTRACT: Background
Many brain disorders, including alcohol use disorder (AUD), are associated with induction of multiple proinflammatory genes. One aspect of proinflammatory signaling is progressive increases in expression across cells and induction of other innate immune genes. High-mobility group box 1 (HMGB1) heteromers contribute to amplification by potentiating multiple proinflammatory responses, including Toll-like receptors (TLRs). TLR signaling recruits coupling proteins linked to nuclear transcription factors that induce proinflammatory cytokines and chemokines and their respective receptors. We tested the hypothesis that AUD induction of TLR expression increases levels of proinflammatory genes and cellular signaling cascades in association with neurodegeneration in the orbitofrontal cortex (OFC).Methods
Postmortem human OFC tissue samples (n = 10) from males diagnosed with AUD were compared to age-matched moderate drinking controls (CON). Neuroimmune signaling molecules were assessed using immunohistochemistry for protein and reverse transcription polymerase chain reaction for messenger RNA (mRNA).Results
In the AUD OFC, we report induction of the endogenous TLR agonist HMGB1 as well as all TLRs assessed (i.e., TLR2-TLR9) except TLR1. This was accompanied by increased expression of the TLR adaptor protein myeloid differentiation primary response 88 (MyD88), activation of the proinflammatory nuclear transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and downstream induction of proinflammatory cytokines, chemokines, and their corresponding receptors. Several of these proinflammatory signaling markers are expressed in glia and neurons. The induction of HMGB1-TLR-MyD88-NFκB proinflammatory signaling pathways correlates with neurodegeneration (i.e., Fluoro-Jade B), lifetime alcohol consumption, and age of drinking onset.Conclusion
These data implicate the induction of HMGB1-TLR-MyD88-NFκB cascades through coordinated glial and neuronal signaling as contributors to the neurodegeneration seen in the postmortem human OFC of individuals with AUD.
SUBMITTER: Vetreno RP
PROVIDER: S-EPMC8526379 | biostudies-literature | 2021 Sep
REPOSITORIES: biostudies-literature
Alcoholism, clinical and experimental research 20210820 9
<h4>Background</h4>Many brain disorders, including alcohol use disorder (AUD), are associated with induction of multiple proinflammatory genes. One aspect of proinflammatory signaling is progressive increases in expression across cells and induction of other innate immune genes. High-mobility group box 1 (HMGB1) heteromers contribute to amplification by potentiating multiple proinflammatory responses, including Toll-like receptors (TLRs). TLR signaling recruits coupling proteins linked to nuclea ...[more]