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

PURPOSETo investigate the effects of estrogen G protein-coupled receptor 30 (GPR30) agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury (TBI).

METHODSMale SD rats were randomly divided into sham group, TBI + vehicle group, TBI + G1 group. Experimental moderate TBI was induced using Feeney's weigh-drop method. G1 (100μg/kg) or vehicle was intravenously injected from femoral vein at 30 min post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. M1 type microglia markers (iNOS and IL-1β) and M2 type markers (Arg1 and IL-4) were examined by immunoblotting or ELISA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting.

RESULTSG1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1β production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt.

CONCLUSIONSGPR30 agonist G1 inhibited neuronal apoptosis and favored microglia polarization to M2 type.

Animals ; Apoptosis ; drug effects ; Brain Injuries, Traumatic ; drug therapy ; pathology ; Cell Polarity ; Hippocampus ; drug effects ; Interleukin-1beta ; biosynthesis ; Male ; Microglia ; drug effects ; Neurons ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; agonists

The possible role of minocycline in microglial activation and neuronal death after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in mice was investigated in this study. The mice were given potassium chloride to stop the heart beating for 8 min to achieve CA, and they were subsequently resuscitated with epinephrine and chest compressions. Forty adult C57BL/6 male mice were divided into 4 groups (n=10 each): sham-operated group, CA/CPR group, CA/CPR+minocycline group, and CA/CPR+vehicle group. Animals in the latter two groups were intraperitoneally injected with minocycline (50 mg/kg) or vehicle (normal saline) 30 min after recovery of spontaneous circulation (ROSC). Twenty-four h after CA/CPR, the brains were removed for histological evaluation of the hippocampus. Microglial activation was evaluated by detecting the expression of ionized calcium-binding adapter molecule-1 (Iba1) by immunohistochemistry. Neuronal death was analyzed by hematoxylin and eosin (H&E) staining and the levels of tumor necrosis factor-alpha (TNF-α) in the hippocampus were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that the neuronal death was aggravated, most microglia were activated and TNF-α levels were enhanced in the hippocampus CA1 region of mice subjected to CA/CPR as compared with those in the sham-operated group (P<0.05). Administration with minocycline 30 min after ROSC could significantly decrease the microglial response, TNF-α levels and neuronal death (P<0.05). It was concluded that early administration with minocycline has a strong therapeutic potential for CA/CPR-induced brain injury.
Animals ; Cardiopulmonary Resuscitation ; Cell Death ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Heart Arrest ; pathology ; Hippocampus ; cytology ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Microglia ; cytology ; drug effects ; Minocycline ; pharmacology ; Neurons ; drug effects ; 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

Aggregation and accumulation of beta-amyloid peptide (Abeta) in brain tissues contribute to the pathogenesis of Alzheimer's disease. Therefore, the promotion of Abeta clearance is one of the key targets for preventing and treatment Alzheimer's disease. Studies proved that some traditional Chinese medicine (TCM) compounds and extracts could impact the activity of degrading enzyme in amyloid peptide, the transport of hemato encephalic barrier and the phagocytosis of microglial cells, promote Abeta clearance, and improve learning and memory of animal models with Alzheimer's disease. In this review, we made an summary for the relations between Abeta and Alzheimer's disease, the Abeta clearance mechanism and the clearance effect of traditional Chinese medicines.
Alzheimer Disease ; drug therapy ; metabolism ; pathology ; Amyloid beta-Peptides ; chemistry ; metabolism ; Animals ; Blood-Brain Barrier ; drug effects ; metabolism ; Humans ; Medicine, Chinese Traditional ; methods ; Microglia ; drug effects ; metabolism ; Protein Multimerization ; drug effects

OBJECTIVE: To observe the effect of Naoling decoction on the learning and memory behaviors and the expression of microglia and IL-6 in hippocampal CA3 region of rats with Alzheimer's disease (AD), and to elucidate the potential mechanism. METHODS: Thirty SD rats were randomly divided into 5 groups: a normal group, a sham-operation group, an AD group, a Naoling decoction group and a Naofukang group. The spatial learning and memory behaviors of the rats were investigated by water maze and Y-maze. The Alzheimer's disease model was established by injecting Aβ1-42 into the hippocamal of the rats. Expression of OX-42 (one of the microglia specific markers) and IL-6 in the CA3 region of hippocamal was measured by immunohistochemical stain. RESULTS: Morris water maze experiment showed that the escape latency of hidden platform in the AD group was significantly delayed (P<0.05) and the average times of passing was decreased (P<0.05). Y-maze test showed that the times needed to the learn how to evade the electrical stimulation in the AD group was most than in other groups (P<0.05). Compared with the AD group, the Morris water maze test and Y-maze test of the Naoling decoction group were significantly different (P<0.05). The expression of OX-42 and IL-6 in the CA3 region of hippocamal in the Naoling decoction group was decreased (P<0.05). CONCLUSION Naoling decoction can improve learning and memory, and weaken the expression of OX-42 and IL-6 in hippocampal CA3 of AD rats, which may partly be the therapeutic mechanism of Naoling decoction for AD.
Alzheimer Disease ; drug therapy ; metabolism ; Animals ; CA3 Region, Hippocampal ; metabolism ; pathology ; Disease Models, Animal ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Interleukin-6 ; genetics ; metabolism ; Learning ; drug effects ; Male ; Memory ; drug effects ; Microglia ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate whether analgesic effect of electroacupuncture (EA) is affected by p38 mitogen-activated protein kinase (p38 MAPK) on microglia.

METHODSThere were two experiments. The experiment 1: 40 male Sprague-Dawley (SD) rats were randomly divided into the normal, surgery, EA and sham EA groups, and the L5 spinal nerve ligation (SNL) on the right side was used to establish neuropathic pain model. EA was applied to bilateral Zusanli (ST36) and Kunlun (BL60) at 24, 48 and 72 h after SNL for 30 min, once per day. The paw withdrawal thresholds (PWTs) were measured before surgery (as base) and at 24, 25, 49 and 73 h after surgery. Phospho-p38 MAPK (p-p38 MAPK), oxycocin-42 (OX-42, marker of microglia), and glial fibrillary acidic protein (GFAP, marker of astrocyte) in bilateral spinal cord dorsal horn (SCDH) were detected by immunofluorescence, respectively. The experiment 2: 40 male SD rats were cannulated for SNL-induced neuropathic pain, and then were randomly divided into the dimethyl sulfoxide (DMSO), EA plus DMSO, 4-(4-fluorophenyl)-2-(4-methylsulfonylpheny)-5-(4-pyridyl)-1H-imidazole (SB203580) and EA plus SB203580 groups. SB203580 (30 nmol/L) was administered 5 min prior to EA treatment. The PWTs and OX-42 in bilateral SCDH were measured as mentioned above.

RESULTSSNL-induced neuropathic pain reduced PWTs and increased the expression of p-p38 MAPK and OX-42 in bilateral lumbar SCDH of rats (P<0.01). Spinal p-p38 MAPK was only co-localized with OX-42 in our study. EA treatment significantly alleviated SNL-mediated mechanical hyperalgesia, and suppressed the expression of p-p38 MAPK and OX-42 in lumbar SCDH (P<0.05 or P<0.01). Intrathecal injection of low dose SB203580 had no influence on PWTs (P>0.05), but significantly inhibited the expression of OX-42 positive cells in bilateral SCDH (P<0.01 or P<0.05). EA plus SB203580 synergistically increased PWTs, and reduced the expression of bilateral spinal OX-42 (P<0.01 or P<0.05).

CONCLUSIONSThe central mechanism of EA-induced anti-hyperalgesia may be partially associated with the reduced expression of p-p38 MAPK, and subsequently reducing the activation of OX-42 in neuropathic pain. Therefore, EA may be a new complementary and alternative therapy for neuropathic pain.

Animals ; Biomarkers ; metabolism ; CD11b Antigen ; metabolism ; Electroacupuncture ; Fluorescent Antibody Technique ; Hyperalgesia ; pathology ; therapy ; Imidazoles ; pharmacology ; Ligation ; Male ; Microglia ; drug effects ; enzymology ; pathology ; Neuroglia ; drug effects ; metabolism ; Phosphorylation ; drug effects ; Posterior Horn Cells ; drug effects ; enzymology ; pathology ; Pyridines ; pharmacology ; Rats, Sprague-Dawley ; Spinal Nerves ; drug effects ; pathology ; p38 Mitogen-Activated Protein Kinases ; metabolism

As one of trials on neuroprotection after spinal cord injury, we used pregabalin. After spinal cord injury (SCI) in rats using contusion model, we observed the effect of pregabalin compared to that of the control and the methylprednisolone treated rats. We observed locomotor improvement of paralyzed hindlimb and body weight changes for clinical evaluation and caspase-3, bcl-2, and p38 MAPK expressions using western blotting. On histopathological analysis, we also evaluated reactive proliferation of glial cells. We were able to observe pregabalin's effectiveness as a neuroprotector after SCI in terms of the clinical indicators and the laboratory findings. The caspase-3 and phosphorylated p38 MAPK expressions of the pregabalin group were lower than those of the control group (statistically significant with caspase-3). Bcl-2 showed no significant difference between the control group and the treated groups. On the histopathological analysis, pregabalin treatment demonstrated less proliferation of the microglia and astrocytes. With this animal study, we were able to demonstrate reproducible results of pregabalin's neuroprotection effect. Diminished production of caspase-3 and phosphorylated p38 MAPK and as well as decreased proliferation of astrocytes were seen with the administration of pregabalin. This influence on spinal cord injury might be a possible approach for achieving neuroprotection following central nervous system trauma including spinal cord injury.
Animals ; Apoptosis/drug effects ; Astrocytes/drug effects/pathology ; Blotting, Western ; Body Weight/drug effects ; Caspase 3/genetics ; Cell Proliferation ; Fluorescent Antibody Technique ; Gene Expression ; Hindlimb/drug effects/pathology/physiopathology ; Inflammation ; Male ; Methylprednisolone/therapeutic use ; Microglia/drug effects/pathology ; Motor Activity/drug effects ; Neuroglia/*drug effects/pathology ; Neuroprotective Agents/*therapeutic use ; Paralysis/drug therapy ; Proto-Oncogene Proteins c-bcl-2/genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries/*drug therapy/pathology ; gamma-Aminobutyric Acid/*analogs & derivatives/therapeutic use ; p38 Mitogen-Activated Protein Kinases/genetics

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Animals ; Female ; MPTP Poisoning ; drug therapy ; pathology ; physiopathology ; Male ; Materia Medica ; therapeutic use ; Mice ; Mice, Inbred C57BL ; Microglia ; drug effects ; pathology ; Parkinson Disease, Secondary ; chemically induced ; drug therapy ; physiopathology ; Scorpion Venoms ; chemistry

OBJECTIVETo identify the protective effect of lipopolysaccharide (LPS) preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms.

METHODSAfter cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations (0, 1, 3, 6 or 10 ng/mL) of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was determined by measurement of the activity of lactic acid dehydrogenase (LDH). Tyrosine hydroxylase-immunoreactive (TH-IR) neurons and CD11b/c equivalent-immunoreactive (OX-42-IR) microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-alpha (TNF-alpha) levels in the culture media were detected by enzyme-linked immunosorbent assays (ELISA).

RESULTSIn the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191+/-12 in the control slices to 46+/-4, and the LDH activity elevated obviously (P < 0.01), along with remarkably increased number of OX-42-IR cells and production of TNF-alpha (P < 0.01). Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss (the number of TH-IR neurons increased to 126+/-12 and 180+/-13, respectively) and markedly reduced LDH levels (P < 0.05), accompanied by significant decreases of OX-42-IR microglia activation and TNF-alpha production (P < 0.05).

CONCLUSIONLow-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-alpha production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson's disease.

Animals ; CD11 Antigens ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Immunohistochemistry ; Inflammation ; chemically induced ; pathology ; L-Lactate Dehydrogenase ; metabolism ; Lipopolysaccharides ; administration & dosage ; toxicity ; Mesencephalon ; drug effects ; immunology ; pathology ; Microglia ; drug effects ; immunology ; pathology ; Nerve Degeneration ; metabolism ; pathology ; prevention & control ; Neurons ; drug effects ; immunology ; pathology ; Organ Culture Techniques ; Rats ; Tumor Necrosis Factor-alpha ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism