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OBJECTIVE To study the repair effect of ephedrine on lipopolysaccharide （LPS）-induced microglia function injury and its mechanism. METHODS Human microglia cells （HMC3） were used as research objects to investigate the effects of different concentrations of ephedrine （75， 150， 300， 600 μg/mL） on the viability and apoptosis of HMC3 cells. HMC3 cells were divided into control group （without drug intervention）， LPS group （1 μg/mL）， ephedrine group （1 μg/mL LPS+300 μg/mL ephedrine）， BAY11-7082 group [1 μg/mL LPS+5 μmol/L nuclear factor-κB （NF-κB） pathway inhibitor BAY11-7082]， inhibitor group （1 μg/mL LPS+300 μg/mL ephedrine+5 μmol/L BAY11-7082） and activator group （1 μg/mL LPS+300 μg/mL ephedrine+1 μmol/L NF-κB pathway activator Prostratin）. After 24 hours of drug treatment， cell migration， the levels of soluble interleukin-6（sIL-6）， interleukin-10（IL-10）， superoxide dismutase（SOD）and malondialdehyde（MDA）， and the expressions of NF-κB pathway-related proteins were all detected. RESULTS The viability of HMC3 cells could be increased significantly by 300 μg/mL ephedrine， while the apoptotic rate was decreased significantly （P＜0.05）. Compared with the control group， the number of migrating cells was increased significantly in the LPS group； the levels of sIL-6 and MDA， the phosphorylation of NF-κB protein were increased significantly， while the levels of IL-10 and SOD were decreased significantly （P＜0.05）. Compared with the LPS group， the above indexes were reversed significantly in the ephedrine group and BAY11-7082 group （P＜0.05）. Compared with the ephedrine group， the number of migrating cells was decreased significantly in the inhibitor group； the levels of sIL-6 and MDA， the phosphorylation of NF-κB protein were decreased significantly， while the levels of IL-10 and SOD were increased significantly （P＜0.05）. The above indexes were reversed significantly in the activator group （P＜0.05）can repair cell injury by inhibiting LPS induced apoptosis， migration， inflammation and oxidant stress of HMC3 cells， the mechanism of which may be associated with inhibiting the activity of the NF-κB signaling pathway.
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Objective:To study the role of a novel brain-derived peptide hypoxic-ischemic brain damage associated peptide (HIBDAP) in regulating pyroptosis of oxygen-glucose deprived (OGD) microglia.Methods:The sequence of HIBDAP was coupled with the sequence of cell-penetrating peptide transactivator of transcription (TAT) to form TAT-HIBDAP. Fluorescein isothiocyanate (FITC) labeled TAT-HIBDAP was added to microglia cells and observed under fluorescence microscope. Microglia cells were treated with different concentrations of TAT-HIBDAP (1, 5, 10, 20 μmol/L) and then OGD process. Cell pyroptosis was analyzed using lactate dehydrogenase (LDH) assay. The concentration of TAT-HIBDAP with the most prominent inhibiting effects was determined and selected for subsequent experiments. The pyroptosis morphology of the control group, the OGD group and the HIBDAP group (5 μmol/L TAT-HIBDAP+OGD) was observed using transmission electron microscope. The mRNA and protein expression of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes were examined using real-time quantitative PCR and Western Blot analysis.Results:Fluorescence microscope showed FITC-labeled TAT-HIBDAP could successfully enter microglia cells. Compared with the OGD group, low concentrations of TAT-HIBDAP (1, 5, 10 μmol/L) could significantly reduce microglia pyroptosis and the concentration of 5 μmol/L showed the most prominent effects. Compared with the control group, OGD group showed typical pyroptosis morphology and HIBDAP group showed significantly improved morphology. The mRNA and protein expression of NLRP3 inflammasomes in the OGD group were significantly higher than the control group and also the HIBDAP group.Conclusions:The novel brain-derived peptide HIBDAP may reduce the expression of NLRP3 inflammasomes and inhibit the pyroptosis of OGD microglia.
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Objective To study the effects of TYRO protein kinase-binding protein (TYROBP) deficiency on learning behavior, glia activation and pro-inflammatory cycokines, and Tau phosphorylation of a new Alzheimer's disease (AD) mouse model carrying a PSEN1 p.G378E mutation.Methods A new AD mouse model carrying PSEN1 p.G378E mutation was built based on our previously found AD family which might be ascribed to the PSEN1 mutation, and then crossed with TYROBP deficient mice to produce the heterozygous hybrid mice (PSEN1G378E/WT; Tyrobp+/-) and the homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/-). Water maze test was used to detect spatial learning and memory ability of mice. After the mice were sacrificed, the hippocampus was excised for further analysis. Immunofluorescence was used to identify the cell that expresses TYROBP and the number of microglia and astrocyte. Western blot was used to detect the expression levels of Tau and phosphorylated Tau (p-Tau), and ELISA to measure the levels of pro-inflammatory cytokines. Results Our results showed that TYROBP specifically expressed in the microglia of mouse hippocampus. Absence of TYROBP in PSEN1G378E mutation mouse model prevented the deterioration of learning behavior, decreased the numbers of microglia and astrocytes, and the levels of interleukin-6, interleukin-1β and tumor necrosis factor-α in the hippocampus (all P < 0.05). The ratios of AT8/Tau5, PHF1/Tau5, pT181/Tau5, pT231/Tau5 and p-ERK/ERK were all higher in homozygous hybrid mice (PSEN1G378E/G378E; Tyrobp-/- mice) compared with PSEN1G378E/G378E mice (all P < 0.05). Conclusions TYROBP deficiency might play a protective role in the modulation of neuroinflammation of AD. However, the relationship between neuroinflammation processes involving microglia and astrocyte activation, and release of pro-inflammatory cytokines, and p-Tau pathology needs further study.
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Mice , Animals , Alzheimer Disease/genetics , Neuroinflammatory Diseases , Hippocampus/pathology , Mutation , Cytokines/pharmacology , Disease Models, Animal , tau Proteins/pharmacology , Amyloid beta-Peptides/metabolism , Adaptor Proteins, Signal Transducing/pharmacologyABSTRACT
Objective:To investigate the effect of Xiaoyaosan on depressive behavioral phenotype in mice with vascular dementia （VaD） mice and its possible mechanism. Method:Sixty three-month-old male C57/BL6 mice were divided into the normal control group， model group， positive control group， as well as low-， medium-， and high-dose Xiaoyaosan groups. Mice in all groups except for the normal control group underwent bilateral carotid artery stenosis. Two weeks later， they were subjected to chronic restraint stress， 6 h per day， for inducing VaD complicated with depression. Mice in the low-， medium-， and high-dose Xiaoyaosan groups were treatment with intragastric administration of Xiaoyaosan decoction （5， 10， 20 g·kg<sup>-1</sup>）， the ones in the positive control group with fluoxetine （10 mg·kg<sup>-1</sup>）， and those in the normal control group and model group with an equal volume of normal saline for four weeks， during which the restraint stress was maintained. The depressive behavioral phenotype of mice was observed in sugar water preference test and tail suspension test. The fluorescence expression of myelin basic protein （MBP） in ventral hippocampus （vHIP） was detected by fluorescence immunoassay. The ultrastructure of myelin sheath in vHIP was observed by transmission electron microscopy. The protein expression levels of MBP， myelin oligodendrocyte glycoprotein （MOG）， myelin-associated glycoprotein （MAG）， triggering receptor expressed on myeloid cells-2 （TREM2）， inducible nitric oxide synthase （iNOS）， arginase 1 （Arg1）， interleukin-I<italic>β</italic> （IL-1<italic>β</italic>）， tumor necrosis factor-<italic>α</italic> （TNF-<italic>α</italic>）， interleukin-4 （IL-4）， and interleukin-10 （IL-10） were assayed by Western blot. Result:As revealed by behavioral test， compared with the normal control group， the model group exhibited prolonged immobility time and decreased percentage of sugar water preference （<italic>P</italic><0.01）. Compared with the model group， Xiaoyaosan significantly shortened the immobility time of mice （<italic>P</italic><0.05） and increased the percentage of sugar water preference （<italic>P</italic><0.01）. Western blot results showed that the protein expression levels of MBP， MOG， and MAG in vHIP of the model group were remarkably decreased as compared with those of the normal control group （<italic>P</italic><0.01）. The protein expression levels of MBP， MOG， and MAG in vHIP of the low-dose Xiaoyaosan group were increased in contrast to those in the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）， while the protein expression of iNOS was decreased （<italic>P</italic><0.01）. The protein expression levels of MBP， MOG， MAG， TREM2， Arg1， IL-4， and IL-10 in the medium- and high-dose Xiaoyaosan groups were up-regulated （<italic>P</italic><0.05， <italic>P</italic><0.01）， whereas those of iNOS， IL-1<italic>β</italic>， and TNF-<italic>α</italic> were down-regulated （<italic>P</italic><0.01）. The immunofluorescence findings demonstrated that the mean fluorescence intensity of MBP in the model group declined in comparison with that in the normal control group （<italic>P</italic><0.01）， while the mean fluorescence intensities of MBP in the low-， medium-， and high-dose Xiaoyaosan groups were enhanced to different degrees （<italic>P</italic><0.01）. It was observed under the transmission electron microscope that the myelin structure of the model group was loosened and the dense layer was separated and irregularly arranged. Xiaoyaosan improved the structural integrity of myelin sheath and the looseness of lamellar structure. Conclusion:Xiaoyaosan ameliorates the depressive behavioral phenotype of VaD mice， which may be related to the up-regulation of TREM2， the induction of M2 polarization of microglia cells， the enhancement of their anti-inflammatory and phagocytic abilities， and the promotion of damaged myelin sheath regeneration.
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Objective: To observe the effect of sea tic nerve pulsed radiofrequency (PRF) on the activation levels of microglia cells and astrocytes in spinal dorsal horn in the chronic constriction injury (CCD rat models, and to explore the relationships between the analgesic mechanism of sciatic nerve PRF and the activation levels of microglia cells and astrocytes in the spinal dorsal horn- Methods: Forty male SD rats were randomly divided into CCI shamoperation+RPF sham group (SS group). CC1 sham-operation + RPF group (SP group). CCI+RPF sham group (CS group). CCI+ RPF group (CP group) ( n 10). PRF was applied on the sciatic nerve on the 4th day after CC1 operation for 120 s, with a maximum temperature of 42"C. The mechanical withdrawal thresholds (MWT) and thermal paw withdrawal latencies 0. 05). Conclusion- PRF on sciatic nerve can relieve the neuropathic pain (NT) of the CCI rat models: PRF on saatic nerve can inhibit activation of the microglia cells in the spinal dorsal horn. The analgeac mechanism of PRF on sciatic nerve may be associated with the inhibition of the activation of microglia cells in the spinal dorsal horn.
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Inflammation is an important mechanism and etiology of depression. In recent years, researchers have demonstrated that many depression patients are with inflammatory reactions in the corresponding brain regions, and simultaneously chemokines play an important role in depression and inflammation. Meanwhile , in the course of depression, chemokines and their receptors are involved in neuroplasticity, the decrease of monoamine neurotransmitters and neuroendocrine system. In this review, in order to further understand and find better treatment of depression, we summarize the recent studies of the relationship between chemokines and depression disorder.
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Aim To investigate the anti-inflammatory effect of salidroside on lipopolysaccharide (LPS)-induced BV2 microglia and its mechanism. Methods The model of LPS-induced injury in BV2 microglia was established. The expression of cytokines IL-6, IL-1β and TNF-α mRNA was detected by qPCR, and the expression of Akt, p-Akt, nuclear protein NF-κB p50 protein was dectected by Western blot with different concentrations of salidroside treatment. The model was sequentially treated with PI3K inhibitor LY294002 for 30 min, and after the treatment of salidroside, the expressions of Akt, p-Akt, nuclear protein NF-κB p50, IL-6, IL-1β, TNF-α and other indicators were dectected by Western blot. Results Compared with model, salidroside reduced the expression of IL-6, IL-1β and TNF-α mRNA in BV2 microglia, improved the expression of p-Akt protein, and reduced the nuclear protein NF-κB p50. After the treatment of LY294002, salidroside had no obvious effect on the expression of p-Akt, nuclear protein NF-κB p50, IL-6, IL-1β. Conclusions Salidroside can inhibit LPS-induced BV2 microglia inflammatory reaction by activating PI3K/Akt signaling pathway, promoting Akt phosphorylation, inhibiting NF-κB p50 nuclear transcription, and inhibiting cytokines.
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Objective:To observe the effect of sciatic nerve pulsed radiofrequency (PRF) on the activation levels of microglia cells and astrocytes in spinal dorsal horn in the chronic constriction injury (CCI) rat models, and to explore the relationships between the analgesic mechanism of sciatic nerve PRF and the activation levels of microglia cells and astrocytes in the spinal dorsal horn.Methods:Forty male SD rats were randomly divided into CCI shamoperation+RPF sham group (SS group) , CCI sham-operation+RPF group (SP group) , CCI+RPF sham group (CS group) , CCI+RPF group (CP group) (n=10) .PRF was applied on the sciatic nerve on the 4th day after CCI operation for 120s, with a maximum temperature of 42℃.The mechanical withdrawal thresholds (MWT) and thermal paw withdrawal latencies (TWL) were measured to evaluate mechanical hyperalgesia and thermal hyperalgesia 1dbefore operation (D0) and 1, 3, 5, 7dafter operation (D1, D3, D5, D7) .Western blotting method was used to detect the protein expression levels of ionized calcium binding adapter molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) in the ipsilateral spinal dorsal horn of L3-5after pain behavioral test (D7) .Results:Compared with SS group, the rats in CS group after CCI had the significant behavioral changes, such as hallux valgus, lameness, toe bending, and foot raising during walking;MWT and TWL were decreased significantly (P＜0.01) ;the expression levels of Iba-1and GFAP proteins in the ipsilateral spinal dorsal horn were increased significantly (P＜0.05) .Compared with CS group, the behavioral changes of the rats in CP group (D5, D7) such as hallux valgus, lameness, toe bending, and foot raising during walking were alleviated significantly;MWT and TWL were increased significantly (P＜0.01) ;the Iba-1protein expression level in spinal dorsal horn was downregulated significantly (P＜0.05) and the GFAP protein expression level did not change significantly (P＞0.05) .Conclusion:PRF on sciatic nerve can relieve the neuropathic pain (NP) of the CCI rat models;PRF on sciatic nerve can inhibit activation of the microglia cells in the spinal dorsal horn.The analgesic mechanism of PRF on sciatic nerve may be associated with the inhibition of the activation of microglia cells in the spinal dorsal horn.
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Toll-like receptors (TLRs) play crucial roles in the innate immune system by recognizing pathogen-associated molecular patterns derived from various microbes and self-derived molecules derived from damaged cells.TLRs can express in multiple cells in the retina, such as glia cells,retinal pigment epithelium (RPE) as well as photoreceptor ceils.When combined with special ligands,TLRs can initiate intracellular signal transduction pathways, induce specific gene expression, and upregulate the expression of costimulatory molecules as well as stimulate the secretion of inflammatory factors which take part in resisting to infection.Furthermore, these inflammatory factors may have an effect on retinal neovascular diseases via regulating angiogenic growth factors level.Microglia cells are the most important part in retinal innate immune system as they can participate in immune surveillance and tissue repair.Among the recognition receptors of microglia cells,TLRs play a significant role in regulating microglia cells which involved in retinal infection and inflammation as well as ischemic retinal diseases.In this review,we focused on the role of TLRs in microglia cells.
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Objective To study the effects of systemic inflammation on the damage of blood brain barrier (BBB) , innate immune cell activation and neuronal degeneration in basal ganglia of diabetic mice and the related mechanisms. Methods Diabetic mouse model was established by-Sltrla|
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Objective To study the type variation of microglial activation in spinal dorsal horn of rats after sciatic nerve injury.Methods Healthy adult male Sprague-Dawley rats were randomly divided into the control and experimental groups, 24 rats in each group.The experimental group underwent ligation of sciatic nerve trunk to generate nerve injury in the rats.The pain behavior in the rats was measured at the 1th, 7th and 14th postoperative days, and the changes of microglial activation in the rat lumbar spinal cord dorsal horn was detected by immunofluorescence staining.qRT-PCR assay was used to validate the activation trends of M1 and M2 types of microglia cells.Results No significant changes were found in the microglial cells in the spinal cord dorsal horn of rats in the sham-operation group during 14 days after operation.In the sciatic nerve ligation group at 1 day after operation, no significant change was observed in the number of microglial cells, but the expression of marker of M1 microglia was significantly increased.At 7 and 14 days after operation, the number of microglial cells and the expression of M1 microglia marker in the spinal cord dorsal horn were increased significantly.Conclusions Microglia activation in the spinal dorsal horn starts at the first day after sciatic nerve injury, and lasts at least for two weeks after the operation.M1 microglia activation dominates during this period.
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Objective: To observe the protection of neuron nutrition active peptide (NNAP) on the Parkinson's disease (PD) rats and its effect on the microglias. Methods: 6-Hydroxydopamine (6-OHDA) was used to prepare the PD rat model. Further, the effects of NNAP on the rotation behavior and the immunoreactivity of substantial nigra dopaminergic (DA) neurons and microglia cells were observed by behavior test and immunocytochemistry. Results: The results show that PD rats treated with NNAP [0.05 mg/ (kg·d), ip] for 7 d behaved the decreased rotation times compared to PD group obviously (P<0.01). Furthermore, in the lesion side of 6-OHDA rat, compared with the model group, the therapeutic rats revealed the obvious increased number and the optical density of DA neurons in 20 000 μm2 measure area (P<0.01); The obvious decreased number and the optical density of the microglia cells compared to PD group in the midbrain (P<0.01). Conclusion: The results suggest that NNAP could inhibit the immunoreactivity of microglia cells, which may involve in the protection function in PD rats.
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Objective To explore the inhibitory effects of Tanshinone Ⅱ A on the radiationinduced microglia activation and the possible mechanism.Methods Microglia cells BV-2 were irradiated with 2,4,8,16,and 32 Gy doses or sham-irradiated in presence or absence of 1.0 μg/ml Tanshinone Ⅱ A for 12 h,respectively.The effects of Tanshinone Ⅱ A on radiation-induced pro-inflammatory cytokines were evaluated using real-time PCR.The expression level of NF-κB p65 in cytoplasm and nucleus was measured by using Western blot.Immunofluorescence staining and confocal microscopy analysis were applied to detect the expression of γ-H2AX and p65 post-irradiation.Results The microglia cells were activated at 16,32 Gy post-irradiation.Radiation-induced release of the pro-inflammatory cytokines in BV-2 cells was detectable after irradiation.Tanshinone Ⅱ A decreased radiation-induced release of proinflammatory cytokines(t=5.56,P ＜ 0.05).Furthermore,western blotting showed that Tanshinone Ⅱ A could attenuate the nuclear translocation of NF-κB p65 submit post-irradiation.Immunofluorescence staining showed that γ-H2AX foci formation while p65 translocation into nucleus post-irradiation.Conclusions Tanshinone Ⅱ A exerts anti-inflammatory properties by suppressing the transcription of proinflammatory cytokine genes that might be associated with NF-κB signaling pathway.It is postulated that irradiation causes immediate cellular reaction and DSB triggers the molecular response which leads to NFκB pathway activation.