OBJECTIVETo investigate the occurrence of delayed neuronal degeneration, activation of microglia and nuclear factor-kappa B after rat intracerebral hemorrhage (ICH) and the possible role of iron.

METHODSICH model was induced by infusion of autologous whole blood into the right basal ganglia. To evaluate the possible role of iron on delayed neuron loss, an iron model by injection of FeCl(2) into hippocampus was also set up. Degeneration of neurons and the activation of microglia and NF-kappa B were detected.

RESULTBoth whole blood and iron caused neuron degeneration for at least 14 days were revealed by Fluoro-jade C staining. Consistently, activated microglia and NF-kappa B positive cells were also observed in the peri-hematoma area and the ipsilateral hippocampus.

CONCLUSIONThe iron may participate in the delayed neuron injury followed ICH; the activated microglia and NF-kappa B may be involved in the process of delayed neuronal injury.

Animals ; Cerebral Hemorrhage ; drug therapy ; pathology ; Ferrous Compounds ; administration & dosage ; Hippocampus ; pathology ; Male ; Microglia ; metabolism ; NF-kappa B ; metabolism ; Nerve Degeneration ; prevention & control ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo explore measures to prevent motor endplate degeneration and muscular atrophy after motor nerve injury.

METHODSThirty Sprague-Dawley rats were randomized into 3 equal groups. In two of the groups, the right common peroneal nerves of the rats were transected and immediately sutured with implantation of collagen gel carrier of acidic fibroblast growth factor (aFGF) or the empty carrier into the denervated tibialis anterior muscles. In the control group, the transected nerves were sutured without implantation. Six weeks after the operation, morphological and electrophysiological examinations were performed.

RESULTSIn the control rats and those with empty collagen gel carrier implantation, obvious motor endplate degeneration and muscular atrophy occurred, which were not obvious in rats receiving aFGF carrier implantation. The decrement of repetitive nerve stimulation was significantly greater in the former two groups than in the latter.

CONCLUSIONImplantation of collagen gel carrier of aFGF may prevent motor endplate degeneration and facilitate functional recovery of the neuromuscular junction after motor nerve injury.

Animals ; Electrophysiology ; Female ; Fibroblast Growth Factor 1 ; pharmacology ; therapeutic use ; Male ; Motor Endplate ; drug effects ; injuries ; physiopathology ; Muscle Denervation ; methods ; Muscular Atrophy ; pathology ; physiopathology ; prevention & control ; Nerve Degeneration ; physiopathology ; prevention & control ; Nerve Regeneration ; drug effects ; Peroneal Nerve ; drug effects ; injuries ; physiopathology ; Rats ; Rats, Sprague-Dawley

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

A degree of brain inflammation is required for repair of damaged tissue, but excessive inflammation causes neuronal cell death. Here, we observe that IL-10 is expressed in LPS-injected rat cerebral cortex, contributing to neuronal survival. Cells immunopositive for IL-10 were detected as early as 8 h post-injection and persisted for up to 3 d, in parallel with the expression of IL-1beta, TNF-alpha, and iNOS. Double immunofluorescence staining showed that IL-10 expression was localized mainly in activated microglia. Next, we examined the neuroprotective effects of IL-10 using IL-10 neutralizing antibody (IL-10NA). Blockade of IL-10 action caused a significant loss of neurons both 3 d and 7 d after LPS injection. Further, the induction of mRNA species encoding IL-1beta, TNF-alpha, and iNOS, reactive oxygen species (ROS) production, and NADPH oxidase activation, increased after co-injection of LPS and IL-10NA, compared to the levels seen after injection of LPS alone. Taken together, these results clearly suggest that LPS-induced endogenous expression of IL-10 in microglia contributes to neuronal survival by inhibiting brain inflammation.
Animals ; Cerebral Cortex/drug effects/*pathology ; Fluorescent Antibody Technique ; Interleukin-10/immunology/*physiology ; Lipopolysaccharides/*pharmacology ; Microglia/cytology/*metabolism ; Nerve Degeneration/pathology/*prevention & control ; Neurons/cytology/drug effects/*metabolism ; Nitric Oxide Synthase/genetics/metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/metabolism