| First Author | Gárate I | Year | 2013 |
| Journal | Biol Psychiatry | Volume | 73 |
| Issue | 1 | Pages | 32-43 |
| PubMed ID | 22906518 | Mgi Jnum | J:315480 |
| Mgi Id | MGI:6829040 | Doi | 10.1016/j.biopsych.2012.07.005 |
| Citation | Garate I, et al. (2013) Stress-induced neuroinflammation: role of the Toll-like receptor-4 pathway. Biol Psychiatry 73(1):32-43 |
| abstractText | BACKGROUND: Stressful challenges are associated with variations in immune parameters, including increased innate immunity/inflammation. Among possible mechanisms through which brain monitors peripheral immune responses, toll-like receptors (TLRs) recently emerged as the first line of defense against invading microorganisms. Their expression is modulated in response to pathogens and other environmental stresses. METHODS: Taking into account this background, the present study aimed to elucidate whether the toll-like receptor-4 (TLR-4) signaling pathway is activated after repeated restraint/acoustic stress exposure in mice prefrontal cortex (PFC), the potential regulatory mechanism implicated (i.e., bacterial translocation), and its role in conditions of stress-induced neuroinflammation, using a genetic strategy: C3H/HeJ mice with a defective response to lipopolysaccharide stimulation of TLR-4. RESULTS: Stress exposure upregulates TLR-4 pathway in mice PFC. Stress-induced inflammatory nuclear factor kappaB activation, upregulation of the proinflammatory enzymes nitric oxide synthase and cyclooxygenase type 2, and cellular oxidative/nitrosative damage are reduced when the TLR-4 pathway is defective. Conversely, TLR-4 deficient mice presented higher levels of the anti-inflammatory nuclear factor peroxisome proliferator activated receptor-gamma after stress exposure than control mice. The series of experiments using antibiotic intestinal decontamination also suggest a role for bacterial translocation on TLR-4 activation in PFC after stress exposure. CONCLUSIONS: Taken together, all the data presented here suggest a bifunctional role of TLR-4 signaling pathway after stress exposure by triggering neuroinflammation at PFC level and regulating gut barrier function/permeability. Furthermore, our data suggest a possible protective role of antibiotic decontamination in stress-related pathologies presenting increased intestinal permeability (leaky gut) such as depression, showing a potential therapeutic target that deserves further consideration. |
