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OBJECTIVE To study the protective effects of Dachengqi decoction （DCQD） on intestinal septic mice， and to explore the possible mechanisms from the Toll-like receptor 4（TLR4）/myeloid differentiation factor 88（MyD88） signaling pathway. METHODS The SPF male C57BL/6J mice were randomly divided into Sham group， Sham+DCQD-H group， model （CLP） group， DCQD-L group， DCQD-H group and Positive group. The model of intestinal sepsis was established by cecal ligation and puncture in CLP group， DCQD-L group， DCQD-H group and Positive group. Three days before the operation and seven days after the operation， DCQD-L group and DCQD-H group were given DCQD intragastrically at 4， 8 g/kg （calculated by crude drug）， respectively. Positive group was given ulinastatin intraperitoneally 2 h before operation and 7 d after the operation （at 50 000 U/kg）. In Sham group and Sham+DCQD-H group， only cecum of mice was exposed without ligation and puncture. Sham+DCQD- H group was given DCQD intragastrically （8 g/kg，calculated by crude drug） 3 days before the operation and 7 days after the operation. Both the Sham group and CLP group were given normal saline 0.2 mL intragstrically and intraperitoneally each day， for 10 consecutive days. After the operation， the severity of sepsis was assessed， and the 7 d survival rate of mice was assessed. One hour after the last medication， the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in serum and ileum of mice were determined； the pathological and morphological changes of mice’s liver， lung， kidney and ileum were observed； mRNA expressions of the TLR4 and MyD88 in ileum were tested. RESULTS Compared with CLP group， sepsis score， the levels of TNF-α and IL-6 in serum and ileum （except for IL-6 in ileum of DCQD-L group）， damage score of the liver， lung， kidney and ileum， mRNA expressions of TLR4 and MyD88 in ileum were all decreased significantly in DCQD-L group and DCQD-H group （P＜0.05 or P＜0.01）， while 7 d survival rate （except for DCQD-L group） was increased significantly （P＜0.05）. The damage to liver tissue in mice was significantly improved， and inflammation infiltration and apoptosis were reduced； lung tissue damage had been alleviated， with varying degrees of improvement in alveolar atrophy， bleeding and edema； the renal tissue damage was improved and weakened dilation of renal tubular lumen was weakened； the damage and edema of ileal tissue were significantly improved. CONCLUSIONS DCQD may exert a protective role on intestinal septic model mice. The mechanism may be related to the inhibition of systemic inflammation， the reduction of multiple organ damage， and down-regulation of TLR4/MyD88 signaling pathway.
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OBJECTIVE Neuroinflammation plays a critical role in neurodegenerative disorders, although the inflammation may not the initiating factor. Parkinson disease (PD) is characterized patho?logically by the accumulation of alpha synuclein (α-syn) and the loss of the dopamine (DA) neurons in the substantia nigra (SN), which has been reported to be induced by the stereotaxic injection of lipopolysaccharide (LPS) to the SN region in rodents. This study is to investigate the therapeutic benefit of the inhibition of miR-873 in PD. METHODS Rats received the right-unilaterally injection with concentrated LV-sponge or LV-EGFP 3 d before LPS treatment, 7 or 14 d after LPS treatment. The animals were tested for rotational behavior with the dopaminergic agonist apomorphine dissolved in sterile saline at 21 d after LPS injection. The regulation of miR-873 on the genes related with cholesterol transport and inflammation was assayed in SH-SY5Y cells and U251 cells. RESULTS TLR4-MyD88 signaling pathway was involved the regulation of miR-873 by LPS. The luciferase assay showed that HMGCR, ABCA1 and A20 were down- stream genes of miR- 873. The transfection of miR- 873 decreased the cholesterol levels in cell membrane, but increased in lysosome in SH-SY5Y cells. Compared with the control SH-SY5Y cells, cholesterol levels were higher in lysosome with α-synuclein overexpression or LPS treatment. The transfection of miR-873 increased the α-syn levels in lysosome in cells with α-synuclein overexpression. The loss of dopaminergic neuorns induced by LPS was significantly respectively decreased by 22.8%, 35.6% and 57% after the inhibition of miR-873 at 3 d before LPS treatment, 7 or 14 d after LPS treatment. Compared with LPS-treated group, the number of the rotation of rats was decreased by 60.4%, 33.5% and 13.2% after the inhibition of miR-873 at 3 d before LPS treatment, 7 or 14 d after LPS treatment. The inhibition of miR-873 significantly decreased accumulation of α-syn. The mRNA levels of HMGCR, ABCA1 and A20 in SN were decreased by LPS treatment, which was attenuated by the injection of LV- sponge. CONCLUSION The selective regulation of miR- 873 can protect the dopaminergic neurons from the LPS-induced damage. The inhibition of miR-873 can attenuate the relocation of cholesterol in lysosome and the accumulation of α-syn in neurons induced by LPS via the regulation of HMGCR, ABCA1 and A20.
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Objective To investigate the effect of isoflurane preconditioning on Toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88) signaling pathway in ischemic penumbra following focal cerebral ischemia-reperfusion (I/R) in rats.Methods Fifty-four healthy male SD rats,aged 3 months,weighing 250-280 g,were randomly divided into 3 groups (n =18 each):sham operation group (group S),I/R group and isoflurane preconditioning group (group IP).Focal cerebral I/R was induced by middle cerebral artery occlusion.In groups I/R and IP,a nylon thread with rounded tip was inserted into the right internal jugular vein and threaded cranially until resistance was met.The middle cerebral artery was occluded for 2 h,followed by 24 h reperfusion.In group IP,the animals inhaled 2.0％ isoflurane for 2 h,and middle cerebral artery occlusion was performed at 24 h after the end of preconditioning.Neurological deficit was scored at 24 h of reperfusion and then the rats were sacrificed.Five rats in each group were chosen and the brains removed for measurement of the cerebral infarct volume.The right cerebral ischemic penumbra was removed for detection of the expression of HSP60,TLR4,MyD88 protein and mRNA by Western blot analysis and real time-PCR.Apoptosis was detected in the ischemic penumbra in the left 3 rats in each group using TUNEL.Apoptosis index (AI) was calculated.Results Neurological deficit scores and AI were significantly increased,the cerebral infarct volume was significantly enlarged,and the expression of HSP60,TLR4,MyD88 protein and mRNA was up-regulated in groups I/R and IP as compared with group S ( P ＜ 0.05).Isoflurane preconditioning significantly reduced the cerebral infarct volume and decreased neurological deficit scores and AI,and down-regulated the expression of HSP60,TLR4,MyD88 protein and mRNA (P ＜ 0.05).Conclusion The mechanisn by which isoflurane preconditioning protects ischenic penumbra following focal cerebral I/R may be related to inhibition of TLR4-MyD88 signaling pathway.