Encephalitis ; metabolism ; pathology ; Microglia ; metabolism ; pathology ; Receptors, Leukotriene ; metabolism ; physiology

Alzheimer Disease/pathology* ; Animals ; C9orf72 Protein/metabolism* ; Mice ; Microglia/pathology* ; Neuronal Plasticity ; Neurons/pathology* ; Synapses/pathology*

Parkinson's disease (PD), a progressive neurodegenerative disorder, is pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the presence of deposits of aggregated α-synuclein in intracellular inclusions known as Lewy bodies (LB). A highly localized inflammatory response mediated by reactive microglia is prominent in PD brains, but the mechanisms underlying the microglial activation are poorly understood. Recently some lines of evidences have shown that monomeric, or aggregated α-synuclein can activate microglia, the toxic factors released from activated microglia may lead to the cell death of dopaminergic neurons. This review is to summarize the recent progress on the role of α-synuclein induced microglia activation on the PD pathogenesis and progression, and to discuss the possible mechanisms involved.
Humans ; Microglia ; pathology ; Parkinson Disease ; etiology ; metabolism ; pathology ; alpha-Synuclein ; chemistry ; metabolism ; physiology

OBJECTIVE: To explore the distribution of inflammatory cells and positive expression of P-se- lectin glycoprotein ligand-1 (PSGL-1) in infant brainstem tissue from hand-foot-mouth disease related fatal brainstem encephalitis. METHODS: Twenty brainstem samples from infants suffered from brainstem en- cephalitis were collected as the experimental group. Ten brainstem samples from infants died of non- brain diseases and injuries were collected as the control group. The distribution of inflammatory cells and the expression of PSGL-1 in the two groups were examined by immunohistochemical method. The characteristics of the positive cells were observed. RESULTS: In brainstem tissue of the experimental group, there were sleeve infiltrations of inflammatory cells around the vessels and in the glial nodule. Microglia was the most and following was neutrophils around the vessels and in the glial nodule. There was a significant statistical difference among microglias, neutrophils and lymphocytes (P < 0.05). There was no sleeve infiltration in the control group. PSGL-1 protein was expressed widely in inflammatory cells in the experimental group, especially in the inflammatory cells around the vessels and in the glial nodule. But PSGL-1 positive staining could be observed significantly less in the control group comparing with the experimental group (P < 0.05). CONCLUSION Microglia is the main type of inflammatory cells involved in the progress of the fatal disease. Moreover, PSGL-1 could participate in the pathogenesis of hand-foot-mouth disease related fatal brainstem encephalitis.
Brain Stem/pathology* ; Encephalitis/pathology* ; Hand, Foot and Mouth Disease/pathology* ; Humans ; Infant ; Membrane Glycoproteins/metabolism* ; Microglia/pathology* ; Neutrophils/pathology*

Glioma is the most common and lethal intrinsic primary tumor of the brain. Its controversial origins may contribute to its heterogeneity, creating challenges and difficulties in the development of therapies. Among the components constituting tumors, glioma stem cells are highly plastic subpopulations that are thought to be the site of tumor initiation. Neural stem cells/progenitor cells and oligodendrocyte progenitor cells are possible lineage groups populating the bulk of the tumor, in which gene mutations related to cell-cycle or metabolic enzymes dramatically affect this transformation. Novel approaches have revealed the tumor-promoting properties of distinct tumor cell states, glial, neural, and immune cell populations in the tumor microenvironment. Communication between tumor cells and other normal cells manipulate tumor progression and influence sensitivity to therapy. Here, we discuss the heterogeneity and relevant functions of tumor cell state, microglia, monocyte-derived macrophages, and neurons in glioma, highlighting their bilateral effects on tumors. Finally, we describe potential therapeutic approaches and targets beyond standard treatments.
Humans ; Glioma/metabolism* ; Neuroglia/metabolism* ; Carcinogenesis/pathology* ; Neural Stem Cells/metabolism* ; Microglia/metabolism* ; Brain Neoplasms/metabolism* ; Tumor Microenvironment

OBJECTIVETo explore the effect of low-concentration lipopolysaccharide (LPS) pretreatment on hyperoxia-induced immature brain injury in neonatal mice and explore and the related mechanisms.

METHODSForty-eight neonatal mice on postnatal day 3 (PND3) were randomized into normal control group, LPS (0.3 mg/kg) group, hyperoxia group (hyperoxia exposure for 24 h), and hyperoxia+LPS group (hyperoxia exposure for 24 h 30 min after 0.3 mg/kg LPS treatment). At PND5, all the neonatal mice were sacrificed to examine the morphological changes of microglia in the periventricular white matter using Tomato lectin staining, measure malondialdehyde (MDA) content in the immature brain, detect mRNA expression of tumor necrosis factor-α (TNF-α) using real-time PCR, and determine caspase-3 protein expression with Western blotting.

RESULTSCompared with the control group, exposures to LPS, hyperoxia, and both all resulted in microglia activation in the periventricular white matter. The number of activated microglia, MDA content, TNF-α mRNA expression and caspase-3 protein expression in the immature brain were significantly higher in hyperoxia group than in the control group and LPS group (P<0.05). LPS pretreatment significantly enhanced hyperoxia-induced microglia activation in the immature brain (P<0.05).

CONCLUSIONHyperoxia causes immature brain injury mediated by microglia activation, and LPS pretreatment can enhance such brain injury in neonatal mice.

Animals ; Animals, Newborn ; Brain ; metabolism ; pathology ; Caspase 3 ; metabolism ; Hyperoxia ; Lipopolysaccharides ; adverse effects ; Malondialdehyde ; metabolism ; Mice ; Mice, Inbred C57BL ; Microglia ; metabolism ; pathology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the effect of the iron chelator deferoxamine (DFA) in suppressing microglia activation and protecting against secondary neural injury in a rat model of intracerebral hemorrhage (ICH).

METHODSSD rats were randomly divided into sham-operated group, ICH group and DFA treatment group. ICH model was established by infusion of type IV collagenase into the right basal ganglia, and starting from 1 h after the operation, the rats received intraperitoneal DFA injections every 12 h for 7 days. The iron content in the perihematoma brain tissue was determined at different time points after DFA administration, and OX42 immunohistochemistry was used to observe the changes in the microglia. The contents of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the brain tissue were detected by ELISA. The neural death and neurological deficiency were measured using Nissl staining and neurological scores, respectively.

RESULTSThe iron content in the brain tissues around the hematoma was significantly increased 3 days after ICH and maintained a high level till 28 days, accompanied by a marked increase of microglial cells as compared to the sham-operated group. DFA injection caused significantly decreased iron content in the brain tissue, reduced number of microglial cells, and lowered levels of IL-1β and TNF-α. Neuronal loss around the hematoma was obviously reversed after DFA injections, which resulted in improved neurological deficiency.

CONCLUSIONDFA can suppress microglia activation by removing iron overload from the perihematoma brain tissue, thus reducing secondary neuronal death and neurological deficiency in rats with ICH.

Animals ; Cerebral Hemorrhage ; metabolism ; pathology ; Deferoxamine ; pharmacology ; Interleukin-1beta ; metabolism ; Iron ; metabolism ; Male ; Microglia ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo prepare and identify a polyclonal antibody (pAb) against (mouse) cysteinyl leukotriene receptor 1 (CysLT(1)) and to investigate the changes of CysLT(1) receptor expression in BV2 microglial cells after rotenone treatment.

METHODSRabbits were immunized with KLH-coupled CysLT(1) peptide to prepare the pAb. The titer of the pAb in rabbit plasma was detected by ELISA method, and the specificity of the pAb was tested by antigen blockade. After BV2 cells were treated with rotenone (0.01-1 μmol/L) for 24 h, the expression of CysLT(1) was determined by immunostaining, Western blotting and RT-PCR.

RESULTThe pAb showed a titer of 1/32728, and was not cross-reacted with antigens of CysLT(2) receptor and GPR17. Immunostaining, Western blotting and RT-PCR analysis showed the expression of CysLT(1) receptor in BV2 microglia. Rotenone at 1μmol/L significantly induced an increased expression of CysLT(1) receptor.

CONCLUSIONThe prepared CysLT(1) receptor polyclonal antibody has a high titer and high specificity to meet testing requirements of Western blotting and immunostaining; CysLT(1) is associated with rotenone-induced injury of BV2 microglial cells.

Animals ; Cells, Cultured ; Male ; Mice ; Microglia ; drug effects ; metabolism ; pathology ; Rabbits ; Receptors, Leukotriene ; immunology ; metabolism ; Rotenone ; pharmacology

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. The finding that cellular microparticles (MPs) generated by injured cells profoundly impact on pathological courses of TBI has paved the way for new diagnostic and therapeutic strategies. MPs are subcellular fragments or organelles that serve as carriers of lipids, adhesive receptors, cytokines, nucleic acids, and tissue-degrading enzymes that are unique to the parental cells. Their sub-micron sizes allow MPs to travel to areas that parental cells are unable to reach to exercise diverse biological functions. In this review, we summarize recent developments in identifying a casual role of MPs in the pathologies of TBI and suggest that MPs serve as a new class of therapeutic targets for the prevention and treatment of TBI and associated systemic complications.
Animals ; Astrocytes ; metabolism ; pathology ; Biological Transport ; Blood Coagulation Factors ; genetics ; metabolism ; Brain ; metabolism ; pathology ; physiopathology ; Brain Injuries, Traumatic ; genetics ; metabolism ; pathology ; physiopathology ; Cell-Derived Microparticles ; chemistry ; metabolism ; pathology ; Cytokines ; blood ; genetics ; Disease Models, Animal ; Disseminated Intravascular Coagulation ; genetics ; metabolism ; pathology ; physiopathology ; Gene Expression Regulation ; Humans ; Microglia ; metabolism ; pathology ; Neurons ; metabolism ; pathology ; Signal Transduction

Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. In particular, increasing evidence has showed that astrocyte-mediated neuroinflammation is involved in the pathogenesis of PD. As a precious traditional Chinese medicine, bear bile powder (BBP) has a long history of use in clinical practice. It has numerous activities, such as clearing heat, calming the liver wind and anti-inflammation, and also exhibits good therapeutic effect on convulsive epilepsy. However, whether BBP can prevent the development of PD has not been elucidated. Hence, this study was designed to explore the effect and mechanism of BBP on suppressing astrocyte-mediated neuroinflammation in a mouse model of PD. PD-like behavior was induced in the mice by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (30 mg·kg^-1) for five days, followed by BBP (50, 100, and 200 mg·kg^-1) treatment daily for ten days. LPS stimulated rat C6 astrocytic cells were used as a cell model of neuroinflammation. THe results indicated that BBP treatment significantly ameliorated dyskinesia, increased the levels of tyrosine hydroxylase (TH) and inhibited astrocyte hyperactivation in the substantia nigra (SN) of PD mice. Furthermore, BBP decreased the protein levels of glial fibrillary acidic protein (GFAP), cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS), and up-regulated the protein levels of takeda G protein-coupled receptor 5 (TGR5) in the SN. Moreover, BBP significantly activated TGR5 in a dose-dependent manner, and decreased the protein levels of GFAP, iNOS and COX2, as well as the mRNA levels of GFAP, iNOS, COX2, interleukin (IL) -1β, IL-6 and tumor necrosis factor-α (TNF-α) in LPS-stimulated C6 cells. Notably, BBP suppressed the phosphorylation of protein kinase B (AKT), inhibitor of NF-κB (IκBα) and nuclear factor-κB (NF-κB) proteins in vivo and in vitro. We also observed that TGR5 inhibitor triamterene attenuated the anti-neuroinflammatory effect of BBP on LPS-stimulated C6 cells. Taken together, BBP alleviates the progression of PD mice by suppressing astrocyte-mediated inflammation via TGR5.
Humans ; Mice ; Rats ; Animals ; Aged ; Middle Aged ; Parkinson Disease/pathology* ; Astrocytes/pathology* ; Powders/therapeutic use* ; Ursidae/metabolism* ; NF-kappa B/metabolism* ; Neuroinflammatory Diseases ; Neurodegenerative Diseases/metabolism* ; Cyclooxygenase 2/metabolism* ; Lipopolysaccharides/pharmacology* ; Bile ; Mice, Inbred C57BL ; Microglia ; Disease Models, Animal