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Background Paraquat (PQ) is one of the environmental factors that can cause sporadic Parkinson's disease (PD). Microglia-mediated neuroinflammation plays an important role in the occurrence and development of PD. Our previous studies have found that low doses of PQ can activate BV-2 microglia to the M1 phenotype and exert pro-inflammatory effects, but the associated mechanism is not clear yet. Objective To explore the role of c-Jun N-terminal kinase (JNK)/activator protein 1 (AP-1) signaling pathway in PQ-induced activation of the NOD-like receptor thermal protein domain associated protoin 3 (NLRP3) inflammasome in microglia. Methods An in vitro microglia model was established. The cells were treated with 0, 0.03, 0.06,and 0.12 μmol·L−1 PQ for 24 h, the whole cell protein was extracted. The relative expression levels of JNK, AP-1 constituent proteins (c-Jun, c-Fos), NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspasse-1 precursor (pro caspase-1), interleukin-18 (IL-18), and interleukin-1β (IL-1β) were evaluated by Western blotting, to observe the effects of PQ exposure on JNK/AP-1 signaling pathway and NLRP3 inflammasome. After the treatment of 20 μmol·L−1 JNK inhibitor SP600125, the above proteins were detected again, to explore the driving effect of JNK/AP-1 signaling pathway on NLRP3 inflammasome activation. Results After PQ exposure, the relative expression levels of key proteins of JNK, c-Jun, and c-Fos, NLRP3, ASC, and pro caspase-1 in the 0.06 μmol·L−1 PQ group and the 0.12 μmol·L−1 PQ group were higher than those in the 0 μmol·L−1 PQ group (P＜0.05), and the relative expression levels of IL-18 and IL-1β increased with higher exposure (P＜0.05). After the treatment of JNK inhibitor SP600125, the relative expression levels of key proteins of JNK/AP-1 signaling pathway (JNK, c-Jun, and c-Fos), NLRP3 inflammasome (NLRP3, ASC, and Pro caspase-1), and inflammatory factors (IL-18 and IL-1β) in the control group, the 20 μmol·L−1 SP600125 group, and the 20 μmol·L−1 SP600125+0.06 μmol·L−1 PQ group were lower than those in the 0.06 μmol·L−1 PQ group (P＜0.05). Conclusion PQ exposure can activate the JNK/AP-1 signaling pathway and subsequently drive the activation of NLRP3 inflammasome in BV-2 microglia to mediate neuroinflammatory responses..
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Objective:To establish the fingerprints of Plantaginis Herba.Methods:The fingerprints were determined by UPLC. The peak areas of fingerprints of different parts and origins were analyzed by variance analysis and independent sample t-test. PCA, HCA, PLS-DA and other chemical patterns were analyzed by Simca14.1. The index weight was calculated by CRITIC, and the quality of plantain evaluation was combined with grey correlation degree.Results:The fingerprints of grass, stem, leaf and spike of Plantago depressa Willd. calibrated for 24, 16, 23 and 22 common peaks. The fingerprints of grass, stem, leaf and spike of Plantaginis Herba calibrated for 22, 10, 16 and 22 common peaks, and the fingerprints of commercial mixed plantain calibrated for 23 common peaks. 10 peaks were identified. The analysis of variance showed that there were differences in chromatographic peak areas between different parts of Plantago asiatica L. and Plantago depressa Willd.. And combinedede with PLS-DA, it showed that there were 16 important characteristic indexes in the classification, and the importance ranking was peak 3, 8, 28, 12, 14, 7, 5, 17, 6, 19, 23, 11, 22, 27, 9, 16. The quality evaluation results of critical method combined with grey correlation degree showed that among Plantago depressa Willd., Plantago asiatica L. and commercial mixed plantain herbs, the quality of Plantago asiatica L. was the best. Conclusion:The mixture of plantain exists in the market. The fingerprints established in this study can be used for the identification and quality evaluation of Plantaginis Herba from different sources.
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Objective:To compare the differences of chemical components between single decoction and mixed decoction with different compatibility ratio of Inulae Flos- Haematitum medicinal pair. Methods:UPLC method was used to determine the contents of 5-caffeoylquinic acid, chlorogenic acid, 4-dicaffeoylquinic acid, caffeic acid, isoquercitrin, isochlorogenic acid B, 1,5- dicaffeoyl quinic acid, isochlorogenic acid C and the fingerprints of the single decoctions and mixed decoctions of Inulae Flos- Haematitum medicinal pair in four groups of proportions. The "peak area/sample weight" value of each common peak in the fingerprints was calculated, and the SPSS 26.0 was used for independent-sample t-test analysis. Results:There are significant differences in the "peak area/weight" values of peak 1, peak 2, peak 4, peak 6 , peak 9, peak 10, peak 12, peak 13, peak 15 between mixed decoction and single decoction of Inulae Flos - Haematitum medicinal pair with different compatibility ratios ( P<0.05), with statistical significance; when the compatibility ratio of Inulae Flos- Haematitum medicinal pair was 3:1, the difference of fingerprints and index components content between single decoction and combined decoction was the largest. Except for peak 7 and peak 14, the difference of "peak area/sample weight" value of other characteristic peaks was statistically significant ( P<0.05), and the content difference of 8 index components was statistically significant ( P<0.05). Conclusion:There are differences in the chemical components of Inulae Flos - Haematitum medicinal pair for single decoction and mixed decoction.
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Background Paraquat (PQ), one of the environmental poisons associated with sporadic Parkinson's disease (PD), can cause abnormal aggregation of alpha-synuclein (α-syn), but the research on its conformational changes and subcellular localization is limited. Objective To investigate the effect of PQ on α-syn conformation and subcellular localization in dopaminergic neurons. Methods Forty-eight SPF C57BL/6 male mice were selected and randomly divided into a control group and a model group. The model group was intraperitoneally injected with PQ (15 mg·kg−1), and the control group was intraperitoneally injected with 0.9% normal saline, twice a week for eight weeks to construct a PD-like mouse model. The changes of neurobehavior (by open field test and pole climbing test) were observed to evaluate motor ability of mice. Immunohistochemical staining (IHC) was used to detect the expression levels of tyrosine hydroxylase (TH) and α-syn in the midbrain. Western blotting (WB) was used to measure the protein expression levels of TH and α-syn in midbrain. Human neuroblastoma SH-SY5Y cells were used as dopaminergic neuron in vitro models. After the cells were treated with PQ (100 μmol·L−1) for 0, 12, 24, 36 and 48 h, the expressions of α-syn in whole cell, cytoplasm, and nucleus were detected by WB; the expression level of extracellular α-syn was detected by enzyme-linked immunosorbent assay (ELISA); the change of α-syn location was observed by immunofluorescence assay (IFA). Results The neurobehavioral tests' results showed that compared with the control group, the residence time in peripheral area of mice in the PQ model group increased with the increase of exposure time (P<0.05), the residence time and moving distance in the central region decreased (P<0.05), and the pole climbing time increased (P<0.05). The mouse IHC results showed that compared with the control group, the number of TH positive cells in the midbrain decreased in the model group at week 6 and 8 (P<0.05), while the expression level of α-syn increased at week 4, 6, and 8 (P<0.05). The WB results of mouse showed that the relative expression of TH decreased significantly after 6 and 8 weeks of PQ exposure (P<0.05), and the relative expression of oligomer α-syn increased after 4, 6, and 8 weeks of PQ exposure (P<0.05). The WB of in vitro models results showed that the relative expression of α-syn in cells increased with time (R2=0.7440, P<0.05); the relative expression of α-syn in cytoplasm increased firstly and then decreased with time (P<0.05); the relative expression of α-syn in nucleus increased with time (R2=0.7913, P<0.05). The IFA results of in vitro models showed that the expression of oligomerized α-syn increased and translocated to the nucleus (P<0.05). The ELISA results of in vitro models showed that α-syn increased with the increase of PQ exposure time (P<0.05). Conclusion PQ can increase the expression of α-syn in dopaminergic neurons, induce oligomerization and translocation to the nucleus.