ABSTRACT
Objective:To explore the effect of rapamycin on 1-methyl-4-phenylpyridinium iodide (MPP+ )-induced activation of Nod-like receptor protein 3 (NLRP3) inflammasome in microglia.Methods:The BV2 microglia cells were divided into control group, model group and rapamycin group.The model group and rapamycin group were treated by MPP+ to activate NLRP3 inflammasome, and rapamycin group was pretreated with rapamycin.Quantitative real-time PCR (RT-qPCR) was used to detect the mRNA levels of NLRP3, apoptosis-associated speck-like protein (ASC) and caspase-1.Immunofluorescence was used to detect the protein expression of NLRP3 and interleukin-1β (IL-1β). Western blot was carried out to assess the protein expression of NLRP3, ASC, caspase-1, beclin1 and microtubule-associated protein 1 light chain 3 (LC3).Results:The mRNA levels of NLRP3, ASC and caspase-1 in model group were higher than those in control group ( t=4.825, 3.015, 5.853, all P<0.05). The mRNA levels of NLRP3 and caspase-1 in rapamycin group were lower than those in model group ( t=2.75, 2.89, both P<0.05). In model group, the protein expressions of NLRP3 (1.54±0.22), ASC (1.02±0.13) and caspase-1 (1.42±0.30) were higher than NLRP3 (0.66±0.15), ASC (0.41±0.14) and caspase-1 (0.70±0.10) in control group ( t=5.653, 5.602, 3.964, all P<0.01), while the protein expression of beclin1 (0.28±0.09) and LC3II/LC3I ratio(0.69±0.14) were lower than beclin1 (0.60±0.11) and LC3II/LC3I (1.29±0.23) in control group ( t=4.010, 3.982, both P<0.01). The protein expressions of NLRP3 (0.80±0.18) and ASC (0.68±0.14) in rapamycin group were lower than those in model group ( t=4.413, 3.077, both P<0.05), while the protein expression of beclin1 (0.65±0.20) and LC3II/LC3I ratio(1.42±0.36) were higher than those in model group ( t=2.965, 3.278, both P<0.05). Conclusion:MPP+ activates NLRP3 inflammasome and impairs autophagic function in microglia.Rapamycin inhibits MPP+ -induced activation of NLRP3 inflammasome by restoring autophagic impairment in microglia.
ABSTRACT
Objective To examine neuroinflammation,oxidative damage and neuron loss in the contralateral parie-tal lobecortex of TBI model mice, and to investigate effects of berberine chloride on such secondary damage.Methods TBI model was established by a weight-drop hitting device and mice in berberine group were administered intragastrically with berberine chloride (50mg/kg.day) for 21 days.Immunofluorescence staining was used to assess activity of microglia and astrocyte.Immunohistochemistry was used to assess DNA oxidative damage, neuron loss and expression of COX-2 and iN-OS.Results Activation of microglia and astrocyte, expressions of COX-2 and iNOS and DNA oxidative damage were ob-viously increased by TBI,(19.82 ±1.88)and(16.96 ±1.69)、(13.79 ±4.32)and(8.67 ±0.96)、(27.86 ±5.38) and (16.00 ±7.59)、(31.92 ±6.57)and(24.79 ±2.78)respectively (P0.05). Conclusions TBI can cause neuroinflammation and oxidative damage but not neuron loss in the contralateral parietal lobe cortex.Berberine chloride can significantly suppress neuroinflammtion in the contralateral parietal lobe cortex after TBI.