ABSTRACT
OBJECTIVE@#To investigate whether electroacupuncture (EA) alleviates cognitive impairment by suppressing the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway, which triggers immune-inflammatory responses in the hippocampus of rats with vascular dementia (VaD).@*METHODS@#The experiments were conducted in 3 parts and in total the Sprague-Dawley rats were randomly divided into 8 groups by a random number table, including sham, four-vessel occlusion (4-VO), 4-VO+EA, 4-VO+non-EA, sham+EA, 4-VO+lipopolysaccharide (LPS), 4-VO+LPS+EA, and 4-VO+TAK-242 groups. The VaD model was established by the 4-VO method. Seven days later, rats were treated with EA at 5 acupoints of Baihui (DV 20), Danzhong (RN 17), Geshu (BL 17), Qihai (RN 6) and Sanyinjiao (SP 6), once per day for 3 consecutive weeks. Lymphocyte subsets, lymphocyte transformation rates, and inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α(TNF-α) were measured to assess immune function and inflammation in VaD rats. Transmission electron microscopy was used to observe the ultrastructure of nerve cells in the hippocampus. The levels of TLR4, MyD88, IL-6, and TNF-α were detected after EA treatment. TLR4/MyD88 signaling and cognitive function were also assessed after intracerebroventricular injection of TLR4 antagonist TAK-242 or TLR4 agonist LPS with or without EA.@*RESULTS@#Compared with the 4-VO group, EA notably improved immune function of rats in the 4-VO+EA group, inhibited the protein and mRNA expressions of TLR4 and MyD88 in the hippocampus of rats, reduced the expressions of serum IL-6 and TNF-α (all P0.05).@*CONCLUSIONS@#EA attenuated cognitive impairment associated with immune inflammation by inhibition of the TLR4/MyD88 signaling pathway. Thus, EA may be a promising alternative therapy for the treatment of VaD.
Subject(s)
Animals , Rats , Dementia, Vascular/therapy , Electroacupuncture , Hippocampus/metabolism , Immunity , Myeloid Differentiation Factor 88 , Rats, Sprague-Dawley , Signal Transduction , Toll-Like Receptor 4/metabolismABSTRACT
<p><b>OBJECTIVE</b>To study the influence of hepatocyte growth factor (HGF) antibody on the lung expression level of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1).</p><p><b>METHODS</b>Thirty male Wistar rats were randomly divided into 3 groups: control group, model group, and intervention group. Endotoxin was intratracheally infused in the model and intervention groups. HGF antibody was injected in the rats of the intervention group from day 1 to day 14, while the same volume of saline was injected in the control group. The rats were sacrificed on day 28 after endotoxin treatment. The amounts of MMP-9 mRNA and TIMP-1 mRNA were measured by reverse transcription-polymerase chain reaction, and protein expression levels of MMP-9 and TIMP-1 were measured by immunohistochemistry.</p><p><b>RESULTS</b>In the model group, both mRNA and protein expression levels of TIMP-1 were significantly increased, the same as MMP-9. In the intervention group, the increase of TIMP-1 was remarkably reduced compared with the model group, while the mRNA and protein expression levels of MMP-9 were still increased.</p><p><b>CONCLUSION</b>HGF activity may accelerate the repair of lung injury through contrary regulating the expression levels of TIMP-1 and MMP-9.</p>