Mechanism of Traditional Chinese Medicine in Treatment of Neurodegenerative Diseases by Regulating Polarization Balance of Microglia： A Review / 中国实验方剂学杂志

Neuroinflammation is a common pathological feature of neurodegenerative diseases （NDs）. Microglia （MG）， a resident macrophage in the brain with a unique developmental origin， is the core driver of neuroinflammation. It can participate in the occurrence and development of NDs through different polarization states and play a key role in regulating neurogenesis and synapse shaping and maintaining homeostasis. MG can be divided into M1 pro-inflammatory phenotype and M2 anti-inflammatory phenotype according to its function. The inflammatory mediators released by the M1 phenotype can lead to nerve degeneration and myelin sheath damage， while the activation of the M2 phenotype is required to inhibit the inflammatory response and promote tissue repair. With the advantages of multi-pathway， multi-target， and bidirectional regulation， traditional Chinese medicine can regulate the polarization balance of MG and has dual effects on NDs such as Alzheimer's disease， Parkinson's disease， and multiple sclerosis. The active components of traditional Chinese medicine and its compound can inhibit the activation of MG by regulating phosphatidylinositol-3-kinases/protein kinase B（PI3K/Akt）， NOD-like receptor thermal protein domain associated protein 3（NLRP3）， signal transducer and activator of transcription factor1（STAT1）， nuclear transcription factor kappa B（NF-κB）， and other pathways， promote the polarization of M1 phenotype to M2 phenotype， reduce the expression of interleukin（IL）-6， tumor necrosis factor-α（TNF-α）， and other pro-inflammatory factors， and increase the secretion of IL-10， arginase-1（Arg-1）， and other anti-inflammatory factors. It can also reduce β-amyloid deposition and tau protein expression in Alzheimer's disease， alleviate dopaminergic neuronal damage in Parkinson's disease， and relieve demyelination， inflammatory cell infiltration， and related clinical symptoms of multiple sclerosis. The bidirectional regulation of the M1/M2 polarization balance of MG by traditional Chinese medicine is a potential strategy for the treatment of NDs. This paper focused on the targets of the regulation of MG polarization balance by traditional Chinese medicine monomer and its compound in the treatment of NDs， so as to further study and summarize the existing research results and provide ideas and basis for the future treatment of NDs.

Repair effect of ephedrine on lipopolysaccharide-induced microglia function injury and its mechanism / 中国药房

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.

Chaihu Longgu Mulitang Relieves Generalized Anxiety Disorder in Rats via p38 MAPK/NF-κB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo study whether Chaihu Longgu Mulitang can inhibit hypothalamic inflammation， mitigate anxiety-like behavior， and alleviate anxiety symptoms by regulating the p38 mitogen-activated protein kinase/nuclear factor-κB （p38 MAPK/NF-κB） signaling pathway in the rat model of generalized anxiety disorder （GAD）. MethodTwelve out of 74 Wistar rats were randomly selected as the blank group， and the remaining rats were subjected to chronic restraint stress for the modeling of GAD. The open field test （OFT） and elevated Porteus maze test （PMT） were conducted 14 days after modeling to detect the anxiety-like behaviors. Sixty successfully modeled rats were selected and randomized into model， low-， medium-， and high-dose （6， 12， and 24 g·kg-1， respectively） Chaihu Longgu Mulitang， and diazepam （1 mg·kg-1） groups （n=12） and administrated with corresponding drugs for 14 consecutive days. OFT and PMT were then carried out to examine the anxiety-like behaviors of the rats. The levels of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， and interleukin-1β （IL-1β） in the hypothalamus and serum of rats were determined by the enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）was conducted to determine the mRNA levels of p38 MAPK， NF-κB p65， nuclear factor κB inhibitor α （IκBα）， and ionized calcium binding adaptor molecule 1 （Iba-1）. The protein levels of p38 MAPK， phosphorylated （p）-p38 MAPK， NF-κB p65， p-NF-κB p65， and IκBα in the hypothalamus of rats were determined by Western blot. The expression of Iba-1 in the hypothalamic microglia was detected by immunofluorescence assay. ResultCompared with the blank group， the model group had decreased body weight， scattered dark yellow fur， increased irritability， and preference to hibernation in the corner. In addition， the modeled rats showed increased edge movement distance and time in OFT （P<0.01） and decreased movement distance and time and the number of entries in the open arm in PMT （P<0.01）. The modeling increased the fluorescence intensity of Iba-1 in paraventricular nucleus of hypothalamus （P<0.01）， elevated the levels of IL-1β， IL-6， and TNF-α in the serum and hypothalamus （P<0.01）， up-regulated the protein and mRNA levels of p38 MAPK， NF-κB p65， p-p38 MAPK， p-NF-κB p65， and Iba-1 （P<0.05， P<0.01）， and down-regulated the protein and mRNA levels of IκBα （P<0.01） in the hypothalamus. Compared with the model group， medium- and high-dose Chaihu Longgu Mulitang and diazepam increased the body weight， improved the fur and behaviors， decreased the edge movement distance and time in OFT （P<0.05， P<0.01）， and increased the movement distance and time in the open arm in PMT （P<0.05， P<0.01）. Furthermore， they decreased the fluorescence intensity of Iba-1 in hypothalamic microglia （P<0.05， P<0.01）， lowered the levels of IL-1β， IL-6， and TNF-α in the serum and hypothalamic tissue （P<0.05， P<0.01）， down-regulated the mRNA and protein levels of p38 MAPK， NF-κB p65， p-p38 MAPK， p-NF-κB p65， and Iba-1 （P<0.05， P<0.01）， and up-regulated the mRNA and protein levels of IκBα （P<0.05， P<0.01） in the hypothalamus. ConclusionChaihu Longgu Mulitang can mitigate anxiety-like behaviors and relieve anxiety in GAD rats by inhibiting the p38 MAPK/NF-κB signaling pathway and reducing the activation of microglia and the levels of pro-inflammatory cytokines in the hypothalamus.

Research progress on the mechanisms of microglia in retinal angiogenesis / 国际眼科杂志(Guoji Yanke Zazhi)

As resident immune cells of the retina, retinal microglia constantly monitor the changes of their surroundings and maintain homeostasis through signal transduction with other retinal cells. Retinal microglia play a crucial role not only in the development and physiological processes of the retinal vascular system, but also in pathological neovascularization. In certain retinopathies, activated microglia can stimulate abnormal angiogenesis through neurovascular coupling, leading to irreversible damage. However, the exact mechanisms underlying this process are still unclear. In this review, a brief overview of the relationship between microglia and retinal neovascularization was provided, and the involved cellular and molecular signaling mechanisms were reviewed, aiming to offer new and effective strategies for the prevention and treatment of retinal neovascularization diseases.

Modified Xiaoyaosan Alleviates Depression-like Behaviors by Regulating Activation of Hippocampal Microglia Cells in Rat Model of Juvenile Depression / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of Baihuan Xiaoyao Decoction （Xiaoyaosan added with Lilii Bulbus and Albiziae Cortex） in alleviating depression-like behaviors of juvenile rats by regulating the polarization of microglia. MethodSixty juvenile SD rats were randomized into normal control， model， fluoxetine， and low-， medium-， and high-dose （5.36， 10.71， 21.42 g·kg-1， respectively） Baihuan Xiaoyao decoction groups. The rat model of juvenile depression was established by chronic unpredictable mild stress （CUMS）. The sucrose preference test （SPT） was carried out to examine the sucrose preference of rats. Forced swimming test （FST） was carried out to measure the immobility time of rats. The open field test （OFT） was conducted to measure the total distance， the central distance， the number of horizontal crossings， and the frequency of rearing. Morris water maze （MWM） was used to measure the escape latency and the number of crossing the platform. The immunofluorescence assay was employed to detect the expression of inducible nitric oxide synthase （iNOS， the polarization marker of M1 microglia） and CD206 （the polarization marker of M2 microglia）. Real-time polymerase chain reaction was employed to determine the mRNA levels of iNOS， CD206， pro-inflammatory cytokines ［tumor necrosis factor （TNF）-α， interleukin （IL）-1β， and IL-6］ and anti-inflammatory cytokines （IL-4 and IL-10） in the hippocampus. Western blotting was employed to determine the protein levels of iNOS and CD206 in the hippocampus. The levels of IL-4 and IL-6 in the hippocampus were detected by enzyme-linked immunosorbent assay. ResultCompared with the normal control group， the model rats showed a reduction in sucrose preference （P<0.05）， an increase in immobility time （P<0.05）， decreased motor and exploratory behaviors （P<0.05）， and weakened learning and spatial memory （P<0.05）. In addition， the model rats showed up-regulated mRNA and protein levels of iNOS and mRNA levels of IL-1β， IL-6， and TNF-α （P<0.05）. Compared with the model group， Baihuan Xiaoyao decoction increased the sucrose preference value （P<0.05）， shortened the immobility time （P<0.01）， increased the motor and exploratory behaviors （P<0.05）， and improved the learning and spatial memory （P<0.01）. Furthermore， the decoction down-regulated the positive expression and protein level of iNOS， lowered the levels of TNF-α， IL-1β， and IL-6 （P<0.01）， promoted the positive expression of CD206， and elevated the levels of IL-4 and IL-10 （P<0.01） in the hippocampus of the high dose group. Moreover， the high-dose Baihuan Xiaoyao decoction group had higher sucrose preference value （P<0.01）， shorter immobility time （P<0.01）， longer central distance （P<0.01）， stronger learning and spatial memory （P<0.01）， higher positive expression and protein level of iNOS （P<0.01）， lower levels of TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01）， lower positive expression and mRNA level of iNOS （P<0.05）， and higher levels of IL-4 and IL-10 （P<0.05， P<0.01） than the fluoxetine group. ConclusionBaihuan Xiaoyao decoction can improve the depression-like behavior of juvenile rats by inhibiting the M1 polarization and promoting the M2 polarization of microglia in the hippocampus.

Improvement of Depression-like Behavior of Depression Model Mice by Sinisan via Regulating GSK-3β/A20/C/EBPβ to Inhibit Activation of Microglia / 中国实验方剂学杂志

ObjectiveTo investigate the antidepressant effect of Sinisan （SNS） by regulating glycogen aynthase kinase-3β （GSK-3β）/tumor necrosis factor alpha-induced protein 3（A20）/CCAAT enhancer binding protein β（C/EBPβ） to inhibit the activation of microglia. MethodA total of 72 male C57/6J mice were randomly divided into the normal group， model group， fluoxetine group （5.0 mg·kg-1）， low-dose Sinisan group （4.9 g·kg-1）， medium-dose Sinisan group （9.8 g·kg-1）， and high-dose Sinisan group （19.6 g·kg-1）， with 12 mice in each group. After one week of adaptive feeding， chronic unpredictable mild stress （CUMS） was performed to establish the depression model. In the fifth week， drug treatment was conducted for four weeks. In the ninth week， behavioral tests were performed， including sucrose preference test （SPT）， open field test （OPT）， elevated plus maze （EPM） test， and forced swimming test （FST）. Western blot was used to detect the expression levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， nitric oxide synthase （iNOS）， GSK-3β， A20， and C/EBPβ in the cortex. The expression of M1-polarized ionized calcium-binding adapter molecule 1 （Iba1） and cluster of differentiation 68 （CD68） in microglia was detected by immunofluorescence. ResultAfter eight weeks of CUMS， compared with the normal group， the mice in the model group had a significantly reduced sucrose preference rate （P<0.01）， and the activity in the central area of the OPT was significantly reduced （P<0.01）. The activity in the open arm area of the EPM test was significantly reduced （P<0.05）， and the immobility time of FST was increased （P<0.01）. The expression levels of inflammatory proteins IL-1β， IL-6， and iNOS were increased （P<0.01）， and the fluorescence co-localization index of Iba1 and CD68 was increased （P<0.05）. The protein expression levels of GSK-3β and C/EBPβ were significantly increased （P<0.05， P<0.01）. After four weeks of SNS intervention， compared with the model group， the mice in the SNS group had significantly increased sucrose preference rate （P<0.01）， significantly increased activities in the central area and the open arm area in the OPT and the EPM test （P<0.05）， and significantly reduced immobility time in the FST （P< 0.01）. The protein expression levels of IL-1β， IL-6， and iNOS were significantly decreased （P<0.05）， and the fluorescence co-localization index of Iba1 and CD68 was decreased in the high-dose SNS group （P<0.05）. The protein expression levels of GSK-3β and C/EBPβ in the medium-dose and high-dose SNS groups were significantly decreased （P<0.01）， and that of A20 was significantly increased （P<0.01）. ConclusionThe antidepressant effect of SNS is related to the regulation of GSK-3β/A20/C/EBPβ protein expression and the inhibition of M1-type activation of microglia.

Effects of Siglec-E on parthenolide inhibiting microglia M1 polarization and targeting MAPK/NF-κB pathway / 陆军军医大学学报

Objective To explore the impact of the sialic acid binding lectin-E(Siglec-E)on the inhibitory properties of parthenolide(PTL)against lipopolysaccharide(LPS)-induced M1 polarization of microglia(BV2).Methods ①Single cell sequencing data of Siglece related mouse brain tissue was obtained from Gene Expression Omnibus(GEO)database and divided into the WT group(n=3)and the Siglece-/-group(n=4).The microglia cells were screened,and the enrichment analysis was performed to analyze related differential genes and pathways.BV2 cells were constructed by the shRNA interference technique and were divided into NC-shRNA and Siglece-shRNA to detect the expression level of Siglec-E(Siglece).② NC-shRNA and Siglece-shRNA cells were respectively divided into the Control group,LPS group,PTL group and PTL+LPS group(n=3).The mRNA levels of markers of M1 polarization in microglia,iNOS,IL-1 β and IL-6,were detected by RT-qPCR.Siglecefl/fl and Cx3cr1cre mice were mated to obtain microglia-specific Siglece deletion(Siglecefl/fl×Cx3cr1cre)mice,and LPS-induced neuroinflammation model was established.③ Nine WT and Siglecefl/fl×Cx3cr1cre male mice were assigned to the Control group,LPS group and PTL+LPS group(n=3).RT-qPCR,immunofluorescence assay and Western blotting were used to verify the knock-out effect and polarization-related pathways,and to investigate the mechanism of Siglec-E affecting PTL inhibition of M1 polarization of microglia.Results Compared with the NC-shRNA group,the expression of Siglec-E in the Siglece-shRNA group was significantly decreased(P<0.01),indicating that the Siglec-E knock-down cell model was successfully established.With the stimulation of LPS,mRNA levels ofiNOS,IL-1 β and IL-6 were significantly up-regulated compared with the Control group both in shRNA cells and Siglece-shRNA cells(P<0.01).With the influence of PTL and LPS,the markers of M1 polarization in NC-shRNA cells mentioned before were significantly decreased(P<0.05),while for Siglice-shRNA cells,there were no significant changes in the markers of M1 polarization.PTL inhibited the phosphorylation of JNK and IκB protein(P<0.01)and the nuclear translocation of NF-κB in BV2 cells,down-regulated Siglec-E,and weakened the inhibitory effect.Compared with mice in the WT group,the expression of Siglec-E in microglia of Siglecefl/fl×Cx3cr1cre mice was decreased significantly(P<0.01),and the inhibitory effect of PTL on the phosphorylation of NF-κB in microglia of Siglecefl/fl×Cx3cr1cre mice was also decreased.Conclusion The absence of Siglec-E in microglia attenuates the inhibition of M1 polarization by the MAPK/NF-κB pathway targeted by PTL.

Expression and role of triggering receptor expressed on myeloid cells 2 in high glucose-treated microglia / 基础医学与临床

Objective To explore the expression of triggering receptor expressed on myeloid cells 2(TREM2)in high-glucose microglia and to investigate the role of TREM2 in the proliferation,migration and phagocytosis of high-glucose microglia.Methods Microglia cells were divided into control group and high-glucose treatment group(67.5 mmol/L glucose,24 h).The microglia cells were counted and the expression of Iba1 and TREM2 was de-tected.TREM2 siRNA was transfected to detect the proliferation and migration of microglia.The amyloid β-peptide(Aβ)with a fluorescent tag was added to observe the phagocytosis of Aβ by microglia.Results Compared to normal microglia,the number of microglia significantly decreased after high-glucose treatment(P＜0.001),while the ex-pression of TREM2 and Iba1 markedly increased(P＜0.001).High glucose and TREM2 did not affect the prolifer-ation of microglia.Compared to the normal group,the migration of microglia significantly decreased after high-glu-cose treatment(P＜0.05)and TREM2 did not affect the migration ability of high-glucose microglia.Compared to the normal group,the phagocytosis of Aβ by microglia significantly decreased in the high-glucose treated group(P＜0.001).Furthermore,TREM2 knockdown further decreased the phagocytosis of Aβ by high-glucose microglia(P＜0.001).Conclusions The expression of TREM2 in microglia significantly increases after high-glucose treat-ment,which significantly affects phagocytosis of Aβ by microglia.

Scutellarin inhibitting BV-2 microglia-mediated neuroinflammation via the cyclic GMP-AMP synthase-stimulator of interferon gene pathway / 解剖学报

Objective To explore the effect of scutellarin on lipopolysaccharide(LPS)induced neuroinflammation in BV-2 microglia cells.Methods BV-2 microglia were cultured and randomly divided into 6 groups:control group(Ctrl),cyclic GMP-AMP synthetase(cGAS)inhibitor RU320521 group(RU.521 group),LPS group,LPS+RU.521 group,LPS+scutellarin pretreatment group(LPS+S)and LPS+S+RU.521 group.The expressions of cGAS,stimulator of interferon gene(STING),nuclear factor kappa B(NF-κB),phosphorylated NF-κB(p-NF-κB),neuroinflammatory factors PYD domains-containing protein 3(NLRP3)and tumor necrosis factor α(TNF-α)in BV-2 microglia were detected by Western blotting and immunofluorescent double staining(n= 3).Results Western blotting and immunofluorescent double staining showed that compared with the control group,the expression of cGAS,STING,p-NF-κB,NLRP3 and TNF-α in BV-2 microglia increased significantly after LPS induction(P<0.05),while the expression of cGAS,STING,p-NF-κB,NLRP3 and TNF-α in LPS+S group were significantly lower than those in LPS group(P<0.05).Treatment with cGAS pathway inhibitor RU.521 showed similar effects as the pre-treatment group with scutellarin.In addition,the change of NF-κB in each group was not statistically significant(P>0.05).Conclusion Scutellarin inhibits the neuroinflammation mediated by BV-2 microglia cells,which may be related to cGAS-STING signaling pathway.

C-X3-C motif chemokine ligand 1/C-X3-C motif chemokine receptor 1 pathway in the recovery of memory function in hemorrhagic shock/resuscitation rats / 解剖学报

Objective To investigate the effect of microglia activation regulated by C-X3-C motif chemokine ligand 1(CX3CL1)-C-X3-C motif chemokine receptor 1(CX3CR1)pathway on memory function in hemorrhagic shock/resuscitation rats.Methods The experiment was divided into two parts.In the first part,the rats were randomly divided into sham group,model-0.5 hour group,model-1.5 hour group,model-3 hour group,10 rats in each group.There were differences in the time of hemorrhagic shock among each group.In the second part,rats were randomly divided into control group and CX3CL1 group,10 rats in each group.The rats in CX3CL1 group were treated with CX3CL1 protein factor(intraventricular injection),and the rats in control group were treated with saline.All rats were trained in Morris water maze experiments before model construction,and tests of Morris water maze experiments were carried out after 4 days of model construction.After completion,the whole brains were taken for HE staining and immunohistochemical staining.Cerebrospinal fluid was taken for detection of inflammatory cytokines,and hippocampus tissues were taken for Real-time PCR detection and Western blotting detection.Results Compared with the sham group,the escape latency of rats in model group increased,the number of platform crossings and the resident time in the third quadrant decreased.The neuronal state was impaired in HE staining in model group.In addition,compared with the sham group,the expression of ionized calcium binding adaptor molecule-1(Iba1)in the brain of the rats in model group increased,the contents of tumor necrosis factor-α(TNF-α)and interleukin(IL)-6 in the cerebrospinal fluid increased,and the M1-type microglia markers CD16,TNF-α,IL-1β and inducible nitric oxide synthase(iNOS)mRNA content increased.At the same time,compared with the sham group,the expressions of CX3CL1 and CX3CR1 in the brain of model group decreased,and the expressions of phosphorylated nuclear factor-κB(p-NF-κB)and nucleotide binding oligomerization domain(NOD)-like receptor protein 3(NLRP3)increased.However,compared with the control group,rats in CX3CL1 group had reduced escape latency,increased platform crossing times and quadrantⅢresident time,and recovered neuronal states.In addition,the expression of Iba1 in the brain of CX3CL1 group decreased,the contents of TNF-α and IL-6 in the cerebrospinal fluid decreased,the mRNA contents of M1-type microglia markers like CD16,TNF-α,IL-1β and iNOS decreased,and the mRNA contents of markers of M2-type microglia glial like CD206,transforming growth factor-β(TGF-β),arginase-1(Arg1),Chitinase 3-like protein 1(Ym 1)increased.Conclusion CX3CL1 can help inhibit the excessive activation of microglia,induce the polarization of microglia to M2 type,inhibit the polarization of M1 type,reduce the release of inflammatory cytokines,and alleviate the memory function damage induced by hemorrhagic shock/resuscitation.

Activation of astrocytes in distal segments of the spinal cord mediating widespread pain induced by peripheral nerve injury / 解剖学报

Objective To discuss the relationship between activated glia cells in distal segment of the spinal cord and widespread pain.Methods Fifty female rats were randomly divided into sham group,the chronic constriction injury of the infraorbital nerve(CCI-ION)group,CCI-ION+minocycline(Mino)group,CCI-ION+L-2-aminoadipic acid(LAA)group,and CCI-ION+normal saline(NS)group,n=10 for each group.CCI-ION model was established and Mino,LAA,and normal saline were delivered intrathecally to CCI-ION rats.Immunofluorescence staining was used to detect activated astrocytes and microglia in the medulla oblongata,cervical,thoracic,and lumbar spinal cord segments.On the 7th,14th,21st,28th day,von Frey filaments were used to evaluate the mechanical withdrawal threshold of vibrissa pad,and electronic von Frey tactile pain meter was used to measure the mechanical withdrawal threshold of front paw,chest and hind paw.The radiant thermal stimulator was used to measure the thermal withdrawal threshold of hind paw.Results After intrathecal injection of Mino to inhibit microglia,the activated microglia in each spinal cord segment decreased.Moreover,inhibiting astrocytes by using LAA significantly reduced activated astrocytes in spinal dorsal horn from distal segments.Behavioral assay showed that after intrathecal injection of Mino and LAA,the mechanical allodynia of vibrissa pad in CCI-ION rats was relieved.However,there was no significant difference(P>0.05)in the thermal and mechanical withdrawal thresholds in the hind paw of CCI-ION rats after intrathecal injection of Mino,while intrathecal injection of LAA significantly increased the thermal and mechanical withdrawal thresholds in the hind paw,indicating the relief of widespread pain induced by CCI-ION.Conclusion The activated astrocytes in distal segments of the spinal cord mediated CCI-ION-induced widespread pain.

Research progress of microglia polarization involved in chronic pain / 临床麻醉学杂志

Chronic pain has been a prominent public health issue in China for years,affecting over 30%of the population.The mechanism of chronic pain has always been a controversial and difficult topic of pain medicine research.The polarization of microglia inherent in the central nervous system when the external microenvironment changes and the subsequent neuroinflammatory response are critical in chronic pain.Microglia can polarize into pro-inflammatory M1 or anti-inflammatory M2 phenotypes during neuroin-flammatory reactions,exerting neurotoxic or neuroprotective effects in the nervous system,respectively.The aim of the article is proposed to provide an overview of the main mechanisms of microglial polarization and-how it might contribute to chronic pain.

Research progress on the regulation of cognitive decline by microglia in aging / 临床神经病学杂志

The incidence of dementia increased significantly in the context of an aging population,imposing a significant burden on the economy and society.Therefore,finding the specific mechanism underlying cognitive decline in aging is of paramount significance.Recently,the role of microglia in the initiation and progression of cognitive decline in aging has become a research hotspot.Microglia,the resident immune cells of CNS,play important roles in immunosurveillance,synaptic pruning,damage repair and maintaining immune homeostasis.However,microglia undergo a variety of changes in cell morphology,gene expression and functional status with aging.This article review the impact of normal aging on microglia and the role of microglia in the pathogenesis of cognitive decline in aging,to provide a novel strategy for slowing or preventing the onset of dementia.

The effects of gastrodin on TLR4 expression in microglia induced by ischemia and hypoxia / 神经解剖学杂志

Objective:To determine the effect of gastrodin(GAS)on toll-like receptor 4(TLR4)expression in mi-croglia after hypoxic-ischemic brain damage.Methods:Hypoxia-ischemic brain damage(HIBD)model was established in neonatal rat in vivo.Thirty 3 d SD rats of were randomly divided into there groups:Sham group,HIBD model group,HIBD model+gastrodin intervention group(HIBD+G).Oxygen glucose deprivation(OGD)model was established in BV2 cells in vitro,Control group(Control),oxygen glucose deprivation group(OGD),OGD+gastrodin intervention group(OGD+G)were randomly set in vitro.Both Western Blot and immunofluorescence staining techniques were used to detect the expression of TLR4 in cells of each group in vitro and in the left corpus callosum region in vivo.Results:The expression of TLR4 was significantly increased in OGD-induced microglia.After gastrodin intervention,TLR4 expression was decreased significantly(P＜0.05).Conclusion:GAS can inhibit the expression of TLR4 in activated microglia and thus play a neuroprotective role in HIBD.

Mito-TEMPO inhibits the activation of BV2 microglia induced by lead exposure by reducing mitochondrial damage / 神经解剖学杂志

Objective:To explore the mechanism of Mito-TEMPO inhibiting the activation of BV2 microglia induced by lead(Pb)exposure.Methods:Mouse microglia BV2 were cultured in vitro.The effects of different concentrations of lead exposure on the viability of BV2 cells were determined by MTT colorimetric method,and a model of lead expo-sure was developed and intervened with Mito-TEMPO antioxidant.Immunofluorescence staining was used to detect the expression of M1 activation marker CD86 protein.Enzyme-linked immunosorbent assay was used to detect the expression of pro-inflammatory factors interleukin-1 β(IL-1β),tumor necrosis factor α(TNF-α),interleukin-6(IL-6).Mito-chondrial superoxide indicator(MitoSOX)staining was used to detect the level of mitochondrial oxidative stress.JC-1 staining was used to detect mitochondrial membrane potential.The respiratory ability of mitochondria was detected by cell energy metabolism analysis system(O2k).Results:Compared with the control group,the expression of CD86 protein,the levels of pro-inflammatory cytokines IL-1β,TNF-α and IL-6 in BV2 cells increased significantly,the level of oxidative stress in mitochondria increased significantly,and the mitochondrial membrane potential and respiratory ability decreased significantly in lead exposed group.Mito-TEMPO treatment significantly reduced the oxidative stress and functional damage of mitochondria in BV2 cells,and significantly inhibited the M1 activation level of BV2 cells.Conclusion:The results show that Mito-TEMPO treatment can reverse the M1 activation of BV2 cells induced by lead exposure,and the specific mechanism may be related to the reduction of mitochondrial oxidative stress and dysfunction by Mito-TEMPO.

The effects of minocycline on neuroinflammation in rats with post-traumatic stress disorder / 神经解剖学杂志

Objective:To investigate the effect of minocycline on neuroinflammation of rats with post-traumatic stress disorder(PTSD).Methods:The rat model of PTSD was prepared by a single prolonged stress(SPS)method,and the rats were treated with minocycline(PTSD+Mino group)or normal saline(PTSD group)by gavage.The behavioral changes of rats were detected by light-dark box test.The expression of ionized calcium-binding adapter molecule 1(Iba-1)in hippocampus was detected by immunohistochemical staining.The contents of IL-1β and TNF-α in hippocampus were detected by ELISA,and the expression levels of IL-1β and TNF-α mRNA in hippocampus were detected by real-time RT-PCR(qRT-PCR).Results:After 3 days of SPS stimulation,the anxiety-like behavior of rats was obvious,the expression of Iba-1 in hippocampus was increased,and the contents of IL-1β and TNF-α in hippocampus were in-creased.Minocycline treatment significantly reduced anxiety-like behavior and decreased the expression of Iba-1 in the hippocampus of PTSD rats.Meanwhile,minocycline treatment also decreased the levels of IL-1β and TNF-α mRNA and protein in the hippocampus.Conclusion:Minocycline can improve the anxiety-like behavior of PTSD rats by inhibiting the activation of microglia.

Effect of NLRP3 Knockdown on LPS-induced Inflammatory Response in BV2 Microglia / 华中科技大学学报(医学版)

Objective To evaluate the impact and clinical significance of NOD-like receptor pyrin domain-containing protein 3(NLRP3)in the activation of lipopolysaccharide(LPS)-induced BV2 microglia cells.Methods shRNA plasmids were devised for BV2 microglia transfection,and the most effective transfection segment was identified via RT-PCR and Western blot assays.NLRP3 expression in the cell line was detected by Western blotting,while light microscopy was used to observe morpho-logical alterations in BV2 cells transfected with NLRP3-shRNA.Furthermore,enzyme-linked immunosorbent assay(ELISA)was used to quantify levels of inflammatory cytokines IL-18,IL-1β,TNF-α and NO in cell supernatants.Immunofluorescence staining was used to observe the expression and localization of microglial activation markers iNOS,Arg-1,Iba1,and NLRP3.Results NLRP3 was highly expressed in LPS-induced BV2 cells.The Western blot result showed that the mRNA expression level was the lowest and transfection was the least effective in NLRP3-mus-727 group.Microscopic examination revealed a round or short spindle-shaped morphology in BV2 cells transfected with shNLRP3,which was akin to resting state cells in the blank control group.ELISA showed that pro-inflammatory mediators IL-18,IL-1β,TNF-α and NO levels were decreased in BV2 cells trans-fected with shNLRP3(all P＜0.05).Immunofluorescence staining indicated a relative decrease in iNOS and Iba1 expression,with an upregulation of Arg-1 in BV2 cells transfected with shNLRP3.Conclusion NLRP3 is highly expressed in LPS-induced BV2 cells.Inhibition of NLRP3 expression can suppress the inflammatory response of BV2 cells induced by LPS,promoting their polarization towards the M2 phenotype.

Study on the Effects of Corilagin on Microglia Activation in the Spinal Cord of Morphine-tolerant Rats / 华中科技大学学报(医学版)

Objective This study was designed to investigate the effects of corilagin on morphine-tolerant rats and discuss the reaction mechanism.Methods A rat model of chronic morphine analgesia tolerance was established.The tail-flick latency of rats was detected by using the water bath tail-flick method.The positive cell rate of ionized calcium binding adapter molecule-1(Iba-1)was detected by using immunofluorescence assay.The protein expressions of Iba-1 and mitogen-activated protein kinase(MAPK)pathway-related proteins were detected by Western blotting.The release of interleukin-6(IL-6),tumor necrosis factor alpha(TNF-α)and interleukin-1 beta(IL-1β)was detected by using enzyme-linked immunosorbent assay(ELISA).The mRNA levels of IL-6,TNF-α and IL-1β were detected by using quantitative reverse transcriptase polymerase chain reaction(qRT-PCR).Results Compared with the morphine(Mor)group,the analgesic effect of morphine in morphine+corilagin(Mor+Cor)group was strengthened with the increase of corilagin concentration.Compared with the Control group,the positive cell rate of Iba-1,Iba-1 protein expression level,levels of inflammatory factors IL-6,TNF-α,IL-1β,and the phosphorylated expression levels of MAPK signaling pathway-related proteins extracellular regulated protein kinases(ERK),c-Jun N-terminal kinase(JNK)and p38 were significantly increased in the Mor group,which were then decreased in Mor+Cor group with the increase of corilagin con-centration.Morphine and corilagin treatment(alone or in combination)had no significant effects on the expression levels of ERK,JNK and p38.Conclusion Corilagin reduces morphine tolerance in rats by inhibiting MAPK pathway.

Research progress of RNA m6A methylation in post-stroke cognitive impairment / 天津医药

Post-stroke cognitive impairment(PSCI)is mainly manifested as learning and memory disorders.Highly enriched RNA m6A methylation modification in mammalian brain is involved in glial cell-mediated neuroinflammation.Given that neuroinflammation is the main mechanism for neural damage and spatial and memory impairment of PSCI,it is speculated that RNA m6A methylation modification can regulate the inflammatory response of glial cells after stroke to improve PSCI.This review summarizes and analyzes the role of RNA m6A methylation modification in the development of PSCI and analyzes its detailed mechanism of regulating glial cell-mediated inflammation,which will provide reference for researchers in this field.

Efficient strategies for microglia replacement in spinal cord injury models / 中国组织工程研究

BACKGROUND:As the incidence of spinal cord injury increases with the years and axon regeneration after spinal cord injury was very difficult.How to promote the recovery from spinal cord injury and improve the transplantation efficiency of stem cells and other therapeutic cells after spinal cord injury has been the focus of clinical and scientific research. OBJECTIVE:To establish the efficient transplantation and replacement of mouse spinal cord microglia in the spinal cord injury model. METHODS:CX3CR1 creER-/+::LSL-BDNF-/+-tdTomato mice,CX3CR1+/GFP mice,β-actin GFP mice and C57 BL/6J wild-type mice at 8-10 weeks of age were selected.According to the requirements of the experiment,they were randomly divided into six groups.(1)Sham operation group:eight C57 BL/6J wild-type mice were used when only the lamina was removed without injury.(2)Spinal cord contusion injury group:eight C57 BL/6J wild-type mice were used.(3)Spinal cord crush injury group:eight C57 BL/6J wild-type mice were used.(4)Conjoined symbiotic spinal cord strike injury group:β-actin GFP mice with green fluorescent blood were surgically stitched together with C57 BL/6J wild-type mice,using eight β-actin GFP mice and eight C57 BL/6J wild-type mice.(5)Mr BMT-X Ray group(using PLX5622 to eliminate the spinal microglia and bone marrow transplantation with X-ray radiation):Bone marrow cells from four CX3CR1 creER-/+::LSL-BDNF-/+-tdTomato mice were extracted and transplanted into eight C57 BL/6J wild-type mice for spinal cord injury modeling.(6)Mr BMT-Busulfan group(using PLX5622 to eliminate the spinal microglia and bone marrow transplantation with Busulfan):Bone marrow cells from four CX3CR1+/GFP mice were transplanted into eight C57 BL/6J wild-type mice.The percentage of cell transplantation replacement in this group was observed,and the spinal cord injury model was not established in this group.The sham operation group,spinal cord contusion injury group and spinal cord crush injury group were sampled by perfusion on day 14 after spinal cord injury.The conjoined symbiotic spinal cord strike injury group was sampled by perfusion on day 7 after spinal cord injury.Mr BMT-X Ray group was sampled by perfusion on day 28 after spinal cord injury.Mr BMT-Busulfan group was sampled by perfusion on day 28 after transplantation.The sampling site was a 1.2 cm long spinal cord with the T10 segment as the center.In the Mr BMT-X Ray group and Mr BMT-Busulfan group,additional mouse brain tissue was retained to see if it would lead to brain transplantation and replacement.The number and proportion of transplanted and replaced cells in the damaged area were measured using transgenic mice,symbiosis and immunofluorescence. RESULTS AND CONCLUSION:Compared with the traditional peripheral blood transplantation(9.8%)of mice in the conjoined symbiotic spinal cord strike injury group,the new transplantation methods,Mr BMT-X Ray and Mr BMT-Busulfan,could greatly improve the proportion of spinal microglia transplantation and replacement,which could reach 84.8%and 95.6%,respectively.The difference was significant(P<0.05).The results showed that Mr BMT-X Ray and Mr BMT-Busulfan could achieve efficient replacement of spinal microglia cells,and could improve the problems of low cell transplantation efficiency,few survival numbers and unclear differentiation of the traditional cell transplantation methods.In addition,Mr BMT-X Ray can only replace the microglia in the spinal cord,while Mr BMT-Busulfan could avoid brain inflammation and injury caused by X-ray radiation transplantation.