Omega-3 polyunsaturated fatty acids supplementation attenuates microglia-induced inflammation after traumatic brain injury in rats
10.3760/cma.j.issn.1674-635X.2016.06.009
- VernacularTitle:ω-3多不饱和脂肪酸抑制大鼠创伤性脑损伤后小胶质细胞介导的炎症反应
- Author:
Xiangrong CHEN
;
Baoyuan XIE
;
Shukai WU
;
Zhihui TANG
;
Weipeng HU
- Keywords:
Craniocerebral trauma;
Fatty acids,omega-3;
Microglia;
Inflammatory response;
JNK signaling pathway
- From:
Chinese Journal of Clinical Nutrition
2016;24(6):369-375
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFA) supplementation on neuron apoptosis,brain edema,activation of microglia,inflammatory response and neural function after traumatic brain injury (TBI) in rats,so as to understand the protection of ω-3 PUFA in rats following TBI and its mechanism.Methods TBI model was established using Feeney's method.Ninety SD rats were randomly divided into 5 groups:sham operation group (sham group),TBI group,TBI + selective activator of c-Jun N-terminal kinase (JNK) anisomycin group (TBI + Aniso group),TBI + ω-3 PUFA supplementation group (TBI + ω-3 group),and TBI + ω-3 PUFA supplementation + JNK activation group (TBI + ω-3 + Aniso group).We measured rat behavioral outcomes by modified neurological severity score (mNSS) on day 1,3,and 7 after TBI.Brain water content was measured with wet-dry weight method.The neuron apoptosis and microglial activation (identified by specific marker IBA-1) in TBI cerebral cortex were determined by TUNEL staining and immunofluorescence.Inflammatory cytokines [tumor necrosis factor-α (TNF-α),interleukin (IL)-1α,IL-1β,and IL-6] and the JNK signaling pathway (JNK,pJNK) were tested with reverse transcription-polymerase chain reaction and Western blot,respectively.Results Compared with the sham group,the levels of brain cell apoptosis,brain edema,neuron apoptosis,and inflammatory-relatived factors (TNF-α,IL-1 α,IL-1β,and IL-6) were significantly increased in the other four groups (P ＜ 0.05).Compared with the TBl group,ω-3 PUFA supplementation reduced brain water content following TBI,especially on day 3 after TBI [(78.14 ± 0.57) ％ vs.(82.31 ± 0.81) ％,P ＜ 0.01],and improved neurological function score (P ＜ 0.05).Meanwhile,ω-3 PUFA supplementation suppressed neuron apoptosis,the activation of microglia,and the mRNA and protein expressions of inflammatory cytokines (TNF-α,IL-1α,IL-1 β,IL-6).The activation of JNK signaling pathway was also inhibited by ω-3 PUFA.Conclusion ω-3 PUFA supplementation may markedly reduce brain edema,suppress neuron apoptosis,and improve neurological outcomes after TBI in rats,possibly mediated by inhibiting JNK signaling pathway and microglial activation,reducing microglia-induced cerebral inflammatory responses,demonstrated as down-regulated expression of TNF-α,IL-1α,IL-1β,and IL-6.
