LLDT-8 protects against cerebral ischemia/reperfusion injury by suppressing post-stroke inflammation.
OBJECTIVE
(5R)-5-Hydroxytriptolide (LLDT-8), an analogue of triptolide, displays lower toxicity compared to triptolide and has comparable immunosuppressive effects. We investigated the anti-inflammatory and neuroprotective effects of LLDT-8 on cerebral ischemia/reperfusion injury.


METHODS
Nitric oxide production from microglia was assessed by measuring the nitrite concentration in the culture medium with Griess reagent. Microglial cells and ischemic brain tissues were examined for the expression of proinflammatory mediators by qPCR and western blot. Infarct volumes were assessed with TTC histology. The TLR4/NF-κB signaling pathway was analyzed with western blot and immunocytochemistry.


RESULTS
LLDT-8 significantly reduced infarct sizes and expression of pro-inflammatory cytokines in the ischemic cortex. LLDT-8 inhibited NO release and expression of TNF-α, IL-1β and iNOS in BV-2 microglia and primary microglia treated with LPS. In addition, LLDT-8 suppressed expression of TLR4, degradation of IκBα and nuclear translocation of NF-κB.


CONCLUSIONS
LLDT-8 exerted anti-inflammatory effects and protected against acute cerebral ischemia/reperfusion injury possibly by acting through the IκB/NF-κB cascade to suppress microglia-mediated neuroinflammation.
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China.
Yanke
Y
Chen
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China.
Li
L
Zhang
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China.
Jingshu
J
Ni
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China.
Xiaoyu
X
Wang
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, 215123, PR China.
Jian
J
Cheng
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Road Zu Chong Zhi, Zhangjiang Hi-Tech Park, Shanghai, 201203, PR China.
Yuanchao
Y
Li
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China.
Xuechu
X
Zhen
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China. Electronic address: tcao@suda.edu.cn.
Ting
T
Cao
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, PR China. Electronic address: jiajia@suda.edu.cn.
Jia
J
Jia
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004224:Diterpenes / Q000494:pharmacology / Q000627:therapeutic use*; D053583:Interleukin-1beta / Q000235:genetics; D008297:Male; D008813:Mice, Inbred ICR; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D020521:Stroke / Q000188:drug therapy* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
C509074:5-hydroxytriptolide; D000893:Anti-Inflammatory Agents; D004224:Diterpenes; D053583:Interleukin-1beta; D016328:NF-kappa B; D018696:Neuroprotective Agents; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse
Cerebral ischemia; LLDT-8; Microglia; Neuroinflammation