Ginsenoside Rg1 protects against H2O2‑induced neuronal damage due to inhibition of the NLRP1 inflammasome signalling pathway in hippocampal neurons in vitro
- Authors:
- Published online on: November 30, 2018 https://doi.org/10.3892/ijmm.2018.4005
- Pages: 717-726
-
Copyright: © Xu et al. This is an open access article distributed under the terms of Creative Commons Attribution License.
Abstract
Introduction
Brain ageing is a progressive and gradual accumulation of harmful changes in the brain tissue with age, including oxidative stress injury and neuronal inflammation, which increase the risk of age-related learning and memory impairment (1,2). At present, the oxidative stress theory is recognised as the most feasible hypothesis to explain the ageing process, particularly age-related neuronal degeneration (3-5). Increasing evidence has suggested that reactive oxygen species (ROS) may cause neuronal oxidative stress, inflammation, and neurodegeneration with age (3,6-7). There are several enzymes that can generate intracellular ROS. NADPH oxidase (NOX) is a major source of ROS generation (4,5). It has been found that NOX2 (gp91phox) is constitutively expressed in neurons and significantly increased in the brain of ageing mice (4). The expression of NOX2 subunits p47phox and p67phox are also increased in the cortex of patients with mild cognitive disorders (5). Inflammasomes are NOD-like receptor (NLR) family multiprotein complexes that are responsible for the formation of pro-inflammatory molecules. Neuroinflammation mediated by inflammasomes is important in several age-related neurodegenerative diseases (8,9). NOD-like receptor protein 1 (NLRP1) was the first reported inflammasome (10). The NLRP1 inflammasome is widely expressed in the body and is the main inflammasome in neurons. An increasing number of studies have shown that the NLRP1 inflammasome is associated with age-related neuronal damage and cognitive impairment (8,11). NADPH oxidase-derived ROS accumulation is one of the main pathways for NLRP3 inflammasome activation (12,13). However, whether NOX2-derived ROS can activate the NLRP1 inflammasome, and whether it is involved in neuronal senescence and damage, remain to be elucidated.
Ginsenoside Rg1 (Rg1) is one of the active ingredients of ginseng, which has been used to improve health conditions and delay senescence in China (14,15). It has been reported that Rg1 has significant antioxidant, anti-ageing and neuroprotective effects (16), and Rg1 can improve learning and memory impairment in ageing mice (17,18). Our previous studies showed that Rg1 significantly decreased ROS generation and attenuated the neuronal oxidative stress damage induced by chronic restrain stress in mice (19), and Rg1 protected against neuroinflammation and neuronal injury induced by chronic glucocorticoid exposure (20). These data suggest that Rg1 has a protective effect on neuronal damage due to decreasing ROS generation. Therefore, it was hypothesised that Rg1 may downregulate NOX2 and reduce the production of ROS, thereby inhibiting activation of the NLRP1 inflammasome in hippocampal neurons and protecting against age-related neuronal damage.
In the present study, primary cultured hippocampal neurons were treated with H2O2 (200 µM) for 24 h to mimic age-related neuronal damage. The study evaluated the protective effects of ROS scavenger tempol and Rg1 on H2O2-induced neuronal damage and assessed whether Rg1 regulated the activation of the NLRP1 inflammasome via the inhibition of NOX2 in hippocampal neurons.
Materials and methods
Culture and treatment of hippocampal neurons
Primary hippocampal neurons were prepared from postnatal Sprague-Dawley rats (within 24 h; 6-8 neonates/experiment) obtained from the Center of Laboratory Animals of Anhui Medical University (Hefei, China) and placed in plates coated with poly-L-lysine (10 µg/ml). Neurobasal medium with B-27 supplement (Thermo Fisher Scientific, Inc., Waltham, MA, USA) was used to culture the neurons at 37°C with 5% CO2 as described previously (21). The neurons were cultured for 7 days and divided into six groups: Control group, H2O2 (200 µM) group, H2O2 (200 µM) + tempol (100 µM) group, and H2O2 (200 µM) + Rg1 (1, 5 and 10 µM) groups. With the exception of the control group, the neurons in the groups were treated with H2O2 (200 µM) and tempol (100 µM) or Rg1 (1, 5 or 10 µM) for 24 h. Tempol (Santa Cruz Technology, Inc., Dallas, TX, USA) and Rg1 (content of Rg1 >98%; Chengdu Desite Biotechnology Co., Chengdu, China) were dissolved in distilled water and stored at −80°C. All experimental procedures were performed in accordance with the approved protocol of the Ethics Committee of Anhui Medical University (Anhui, China).
Neuronal apoptosis assay (Hoechst 33258 staining)
Hoechst 33258 can stain the nucleus and is often used to assess the apoptotic rate of neurons (22). First, the neurons were fixed with 4% paraformaldehyde and incubated with Hoechst 33258 (5 µg/ml, Zhongshan Golden Bridge Biotechnology Co., Beijing, China) for 15 min. Following washing with PBS, the neurons were sealed onto slides with anti-fade mounting medium. Fluorescence microscopy was then used to examine the apoptosis of neurons (Olympus IX71; Olympus Corporation, Tokyo, Japan). Morphologically, the apoptotic neurons appeared smaller and bright blue, the nucleus was condensed and deeply stained (23). The apoptotic neurons were counted and the relative neuronal apoptotic rate was examined in each culture and compared with the control.
Examination of ROS production with dihydroethidium (DHE) staining
DHE is the most commonly used ROS fluorescent probe and is often used for labelling living cells to detect the production of ROS (24). For the ROS examination, DHE (10 µM) was added to the medium and incubated for 30 min at 37°C. The production of ROS was then detected using a fluorescence microscope (Olympus IX71, Olympus Corporation). The red mean optical density was performed using Image-Pro Plus 6.0 software (Media Cybernetics, Inc., Rockville, MD, USA), to indicate the ROS production in the hippocampal neurons.
Immunofluorescence
Caspase-3 is the common pathway and the executor of apoptosis (25). To confirm the effect of Rg1 on neuronal apoptosis in H2O2-damaged hippocampal neurons, the expression of caspase-3 was detected by immunofluorescence. First, the hippocampal neurons were fixed with 4% paraformaldehyde for 30 min and washed thoroughly with PBS. Following permeabilisation with Triton X-100 (0.25%) for 30 min, and blocking with 1% BSA (Sigma-Aldrich; Merck KGaA, Darmstadt, Germany) in PBS for 1 h, the neurons were incubated with caspase-3 primary antibody (cat. no. BS7003; lot no. CJ32131; 1:200; Bioworld Technology, Inc., St. Louis Park, MN, USA) overnight at 4°C. Subsequently, the neurons were incubated in secondary antibody conjugated to FITC (cat. no. ZF-0311; lot no. 127805; 1:200; ZSGB-BIO; OriGene Technologies, Inc., Beijing, China) for 1 h at room temperature. The slides were then mounted and examined with a fluorescence microscope (Olympus IX71; Olympus Corporation). The relative fluorescent intensity was quantified from three random fields per slide using the Image-Pro Plus 6.0 analysis system to indicate the expression of caspase-3.
Immunoblotting assay
Radioimmunoprecipitation assay lysis buffer (Beyotime Institute of Biotechnology, Haimen, China) were used to extract the total protein. The protein concentration was determined by BCA Protein Assay kit (Beyotime Institute of Biotechnology). Equal samples of protein (30 µg) were separated by 12% SDS-PAGE and transferred onto a PVDF membrane. The membrane was blocked with 5% skim milk for 1 h at room temperature. The membrane was then incubated with primary antibodies targeting β-galactosidase (β-Gal), NOX2, p22phox, p47phox, NLRP1, apoptosis-associated speck-like protein containing a carboxy-terminal CARD (ASC), caspase-1 and β-actin (1:1,000) overnight at 4°C. The primary antibodies for β-Gal (cat. no. ab9361; lot no. GR27325-12), NOX2 (cat. no. ab31092; lot no. GR91755-40), NLRP1 (cat. no. ab3683; lot no. GR281560-21) and caspase-1 (cat. no. ab1872; lot no. GR615230-38) were from Abcam (Cambridge, UK). The p22phox (cat. no. BS60290; lot no. CN21141) and p47phox (cat. no. BS4852; lot no. CN33161) antibodies were from Bioworld Technologies, Inc. ASC antibody (cat. no. SC-514414; lot no. G1916) was from Santa Cruz Biotechnology, Inc. (Dallas, TX, USA) The dilutions of β-Gal, NOX2, NLRP1 and p47phox were 1:1,000. The dilutions of ASC, caspase-1 and p22phox were 1:500. The membranes were then washed with TBS-Tween 20 and incubated with anti-rabbit IgG antibody conjugated to HRP (cat. no. ZF-2301; lot no. 128615; 1:10,000; ZSGB-BIO; OriGene Technologies, Inc.) at room temperature for 1 h. The protein bands were visualised by using a Chemi Q4800 mini imaging system (Shanghai Bioshine Technology, Shanghai, China). The protein bands were measured with ImageJ 1.44 software (National Institutes of Health, Bethesda, MD, USA) and normalised to the corresponding β-actin bands. The relative density of each target protein over the control was used to represent the changes in expression of target proteins.
Enzyme-linked immunosorbent assay (ELISA)
Following incubation with H2O2 and tempol or Rg1, the supernatants were collected from each group. ELISA kits were used to detect the levels of interleukin (IL)-1β and IL-18 (Cloud-Clone Corp., Houston, TX, USA). Briefly, the samples and the standards of IL-1β and IL-18 were placed into the assay plate and incubated for 1 h at 37°C. Following incubation for 1 h, the HRP-conjugated reagent (100 µl) was added to the wells and incubated for 1 h at 37°C. Subsequently, the chromogen solution (100 µl) was added to the wells. The plate was mixed and incubated for 15 min at 37°C. Stop solution (50 µl) was then added to the wells and the absorbance at 450 nm was detected with a microplate reader (Thermo Fisher Scientific, Inc.) within 15 min.
Statistical analysis
Data are presented as the mean ± standard deviation. Statistical differences were analysed by one-way analysis of variance and the between-group comparisons were subjected to the Bonferroni post hoc test using SPSS 17.0 software (SPSS, Inc., Chicago, IL, USA. P<0.05 was considered to indicate a statistically significant difference.
Results
Rg1 inhibits H2O2-induced neuronal apoptosis and the expression of caspase-3
The present study first examined the effects of Rg1 treatment on H2O2-induced neuronal apoptosis by staining with Hoechst 33258, which can bind to chromatin allowing the visualisation of normal and condensed chromosomes with a fluorescence microscope (22). The results showed that there were few apoptotic neurons in the control group. Compared with the control group, H2O2 exposure significantly increased neuronal apoptosis (Fig. 1A and B; P<0.05). Compared with the H2O2-treated group, Rg1 (5 and 10 µM) treatment significantly reduced neuronal apoptosis (Fig. 1A and B; P<0.05). Treatment with the ROS scavenger tempol (100 µM) significantly decreased the apoptosis of hippocampal neurons induced by H2O2 treatment (Fig. 1A and B; P<0.05).
To confirm the anti-apoptotic effect of Rg1, the effects of Rg1 (5 µM) on the expression of caspase-3 in H2O2-damaged hippocampal neurons was further examined by immunofluorescence. The results showed that, compared with the control group, H2O2 treatment significantly increased the expression of caspase-3. Compared with the H2O2-treated model group, tempol and Rg1 treatments significantly decreased the expression of caspase-3 in H2O2-treated hippocampal neurons (Fig. 2A and B; P<0.05).
Rg1 decreases the expression of senescence-associated β-gal in H2O2-treated hippocampal neurons
Senescent cells exhibit increased senescence-associated β-Gal activity (26). In order to observe the effect of Rg1 on H2O2-induced senescence in hippocampal neurons, the expression of β-Gal was detected by western blot analysis. The results showed that H2O2 (200 µM) treatment significantly increased the expression of β-Gal in the hippocampal neurons compared with the control group (Fig. 3A and B; P<0.01). Compared with the H2O2-treated group, tempol (100 µM) and Rg1 (5 and 10 µM) treatments significantly decreased the expression of β-Gal in the hippocampal neurons (Fig. 3A and B; P<0.05 and P<0.01, respectively).
Rg1 reduces ROS generation in H2O2-treated hippocampal neurons
H2O2 exposure induces cell redox balance disorder, which may cause neuronal senescence and damage. Therefore, ROS production was detected using DHE staining. Compared with the control group, H2O2 treatment significantly increased the production of ROS in the hippocampal neurons (Fig. 4A and B; P<0.01). Compared with the H2O2-treated group, tempol (100 µM) and ginsenoside Rg1 (1, 5 and 10 µM) treatments significantly reduced the production of ROS in hippocampal neurons (Fig. 4A and B; P<0.05).
Effects of Rg1 on the expression of NOX2, p22phox and p47phox in H2O2-treated hippocampal neurons
To confirm whether NADPH oxidase is involved in H2O2-induced neuronal senescence and damage in primary hippocampal neurons, the expression levels of NOX2, p22phox and p47phox in hippocampal neurons were measured by immunoblotting. The results showed that, compared with the control group, the expression levels of NOX2, p22phox and p47phox were significantly increased in the H2O2-treated group (Fig. 5A-C; P<0.05). Compared with the model group, Rg1 (5 and 10 µM) treatment significantly reduced the expression levels of NOX2 and p47phox in the H2O2-treated hippocampal neurons, whereas tempol (100 µM) treatment had no significant influence on their expression. The results showed that Rg1 had no significant influence on the expression of p22phox, whereas tempol treatment increased the expression of p22phox in the H2O2-treated hippocampal neurons (Fig. 5B; P<0.05).
Effect of Rg1 on the expression levels of NLRP-1, ASC and caspase-1 in H2O2-treated hippocampal neurons
To confirm whether Rg1 regulated NLRP1 inflammasome activation, the expression levels of NLRP1, ASC and caspase-1 in primary hippocampal neurons were detected by immunoblotting. The results showed that, compared with the control group, the expression levels of NLRP-1, ASC and caspase-1 were significantly increased in the H2O2-treated group. Compared with the model group, tempol (100 µM) and Rg1 (5 and 10 µM) treatments significantly decreased the expression levels of NLRP1, ASC and caspase-1 in the H2O2-treated hippocampal neurons (Fig. 6A-C; P<0.05).
Rg1 decreases the release of IL-1β and IL-18 in H2O2-treated hippocampal neurons
To confirm the effect of Rg1 on downregulation of the NLRP1 inflammasome, the levels of IL-1β and IL-18 released in supernatants were examined by ELISA. The results showed that, compared with the control group, the release of IL-1β and IL-18 was significantly increased in the H2O2-treated group (Fig. 7A and B; P<0.05). Compared with the model group, tempol (100 µM) and Rg1 (5 and 10 µM) treatments significantly reduced the release of IL-1β and IL-18 in supernatants from the H2O2-treated hippocampal neurons (Fig. 7A and B; P<0.05).
Discussion
It has been reported that oxidative stress and neuroinflammation are involved in neuronal senescence and neurodegenerative diseases, including Alzheimer’s disease (27). The effect of Rg1 is largely associated with its antioxidant and other scavenging properties, for example, inhibiting the expression of inducible nitric oxide synthase and the overgeneration of nitric oxide. However, whether Rg1 can alleviate H2O2-induced senescence and neuronal damage, and its mechanism, warrants further investigation. In the present study, it was demonstrated that H2O2 treatment significantly induced oxidative stress damage and apoptosis in primary hippocampal neurons, and the NOX2-NLRP1 inflammasome pathway was important in H2O2-induced neuronal senescence and damage. In addition, Rg1 significantly reduced the production of ROS and the expression of NOX2 and the NLRP1 inflammasome, and inhibited neuronal senescence and damage in the H2O2-treated hippocampal neurons.
Oxidative stress is caused by the imbalance of redox in the body, resulting in excessive ROS generation. The accumulation of ROS can induce neuronal oxidative stress damage and is involved in the development of ageing-related neurodegenerative diseases (28). In the process of ageing, excessive ROS can lead to destruction of neuronal structure and impairment of learning and memory (29,30). H2O2 treatment is often used to simulate ROS accumulation-induced neuronal damage (31). In the present study, the results showed that H2O2 treatment significantly increased the generation of ROS, promoted neuronal apoptosis and increased the expression of senescence-associated β-Gal in hippocampal neurons.
Ginseng has been used as an anti-ageing drug for thousands of years in China. Numerous studies have shown that Rg1, a main active ingredient in ginseng, has antioxidant and anti-ageing effects, in addition to promoting cognitive function and improving immunity (32,33). Rg1 protects against neuronal damage induced by various mechanisms, including oxidative stress and inflammatory responses (20,34). Tempol is an effective antioxidant and can attenuate the damage caused by excessive accumulation of ROS (35). In the present study, the results showed that both Rg1 and tempol significantly decreased ROS generation and inhibited the expression of β-Gal in H2O2-treated hippocampal neurons. In addition, the Hoechst 33258 staining showed that Rg1 (5 and 10 µM) had a significant effect on H2O2-induced hippocampal neuron apoptosis, whereas Rg1 (1 µM) had no effect on the neuronal apoptosis. Caspase-3 is the most important terminal shear enzyme in the process of apoptosis (33). To confirm the anti-apoptotic effect of Rg1, the effects of Rg1 (5 µM) on the expression of caspase-3 were examined by immunofluorescence. The results showed that Rg1 (5 µM) significantly decreased the expression of caspase-3 in H2O2-induced hippocampal neurons. These results indicate that Rg1 may decrease ROS generation and inhibit neuronal senescence and apoptosis. However, the mechanism underlying the effect of Rg1 on reducing the production of ROS remains to be fully elucidated.
NOX is the most important enzyme system involved in the generation of ROS and has been shown to be important in various neurological diseases (28). NOX2 is a major source of ROS involved in the development of age-related cognitive dysfunction (28). The expression of NOX2 has been found to be increased in the brains of ageing mice (36). NOX2 consists of a membrane-bound catalytic core, including NOX2 (gp91phox) and p22phox), and several cytosolic subunits, including p40phox, p47phox, p67phox and rac1 (37). NOX2 is activated when the cytosolic subunits translocate to the membrane and combine with gp91phox (37,38). There is a linear relationship between the activity of NOX2 and cognitive decline in aged mice (39). In addition, NOX contributes to oxidative stress and neuronal apoptosis. NOX-deficient mice exhibit reduced injury following stroke (40). It is not entirely clear whether Rg1 can reduce NOX2 and, thus, reduce the production of ROS in H2O2-treated hippocampal neurons. In the present study, the results showed that the expression levels of NOX2, p22phox and p47phox were significantly increased in H2O2-treated hippocampal neurons. Rg1 treatment significantly reduced the expression levels of NOX2 and p47phox in H2O2-treated hippocampal neurons, whereas tempol (100 µM) treatment had no significant influence on their expression. The results also showed that Rg1 had no significant influence on the expression of p22phox, whereas tempol treatment increased the expression of p22phox in H2O2-treated hippocampal neurons. Therefore, Rg1 may protect against neuronal ageing and damage by scavenging ROS and inhibiting the formation of ROS derived from NOX2.
Neuroinflammation can accelerate brain ageing, causing neuronal damage and cognitive deficits (41). The chronic, progressive pro-inflammatory response is an important feature of the ageing process and the leading cause of neuronal apoptosis (42). Inflammasomes are multimeric proteins in the cytoplasm of a wide variety of cells (43). Among them, the NLRP1 inflammasome was the first characterised and is expressed widely in the body, particularly in neurons (44,45). The NLRP1 inflammasome consists mainly of NLRP1, caspase-1 and ASC proteins. NLRP1 can activate the key regulatory agent caspase-1 through its own oligomerization. Activated caspase-1 can further cleave pro-IL-18 and pro-IL-1β into active IL-18 and IL-1β, which in turn promote inflammatory responses and apoptosis (46). It has been reported that the NLRP3 inflammasome can be activated by excessive ROS production (47). Our previous study showed that Rg1 protected against chronic dexamethasone-induced neuronal degeneration by inhibiting NLRP-1 inflammasomes in mice (19). It has also been reported that Rg1 can protect against H2O2-induced neuronal apoptosis (33). These studies suggest that Rg1 has an anti-oxidative effect and can inhibit the NLRP1 inflammasome in hippocampal neurons. However, whether Rg1 can down-regulate the NOX2-mediated generation of ROS and thereby inhibit the NLRP1 inflammasome in H2O2-treated hippocampal neurons remained to be elucidated. The present study found that H2O2 treatment significantly increased the expression levels of NLRP-1, ASC and caspase-1 in hippocampal neurons and the levels of IL-1β and IL-18 released into the supernatant. These results suggest that the accumulation of ROS can activate the NLRP1 inflammasome, which may be involved in senescence and damage in hippocampal neurons. The results also showed that tempol and Rg1 treatments significantly decreased the expression levels of NLRP1, ASC and caspase-1, and reduced the levels of IL-1β and IL-18 released into the supernatant. A previous study showed that Rg1 attenuated H2O2-induced neuronal oxidative stress and apoptosis via the downregulation of caspase-3, Rho-associated kinase1 activation and myosin light chain (Ser-19) phosphorylation (33), whereas the present study suggested that Rg1 alleviated H2O2-induced neuronal oxidative stress and apoptosis via the inhibition of NOX2-derived ROS generation and downregulation of the NLRP1 inflammasome.
Overall, the present study demonstrated that Rg1 has antioxidant effects and can reduce the expression of NOX2 and the production of ROS, which in turn inhibits the activation of the NLRP1 inflammasome in H2O2-treated hippocampal neurons. These findings provide support for the hypothesis that Rg1 reduces NOX2-mediated ROS generation and inhibits NLRP1 inflammasome activation. However, whether the overexpression of NOX2 can activate the NLRP1 inflammasome and accelerate neuronal senescence remains to be fully elucidated. Other associated mechanisms of Rg1 on neuronal senescence associated with the NOX2-NLRP1 inflammasome signalling pathway warrant further investigation.
Funding
This study was supported by the National Natural Science Foundation of China (grant nos. 81671384 and 81371329) and the Natural Science Foundation of Anhui Province Education Department (grant no. KJ2016A357).
Availability of data and materials
The datasets used and analysed during the present study are available from the corresponding author on reasonable request.
Authors’ contributions
TZX analysed data, performed the experiments, and was a major contributor in writing the manuscript. XYS, LLS and YLC collated the data, BQZ contributed to the immunoblot analysis and interpretation of the results. DKH was mainly responsible for the immunofluorescence detection. WZL designed the study, critically revised the manuscript for intellectually important content, supervised the study and wrote the manuscript. All authors read and approved the final submitted manuscript.
Ethics approval and consent to participate
All experiments involving animals were approved by the Ethics Committee of Laboratory Animals of Anhui Medical University.
Patient consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Acknowledgments
The authors would like to thank Mr. Bao Li (Synthetic Laboratory of Basic Medicine College, Anhui Medical University) for their technical assistance.
References
|
Floyd RA and Hensley K: Oxidative stress in brain aging. Implications for therapeutics of neurodegenerative diseases. Neurobiol Aging. 23:795–807. 2002. View Article : Google Scholar : PubMed/NCBI | |
|
Joseph JA, Shukitt-Hale B, Casadesus G and Fisher D: Oxidative stress and inflammation in brain aging: Nutritional considerations. Neurochem Res. 30:927–935. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Calabrese V, Cornelius C, Mancuso C, Lentile R, Stella AM and Butterfield DA: Redox homeostasis and cellular stress response in aging and neurodegeneration. Methods Mol Biol. 610:285–308. 2010. View Article : Google Scholar | |
|
Fan LM, Cahill-Smith S, Geng L, Du J, Brooks G and Li JM: Aging-associated metabolic disorder induces Nox2 activation and oxidative damage of endothelial function. Free Radic Biol Med. 108:940–951. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Ansari MA and Scheff SW: NADPH-oxidase activation and cognition in Alzheimer disease progression. Free Radic Biol Med. 51:171–178. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Rehman SU, Shah SA, Ali T, Chung JI and Kim MO: Anthocyanins reversed d-galactose-induced oxidative stress and neuroinflammation mediated cognitive impairment in adult rats. Mol Neurobiol. 54:255–271. 2017. View Article : Google Scholar | |
|
Zotova E, Bharambe V, Cheaveau M, Morgan W, Holmes C, Harris S, Neal JW, Love S, Nicoll JA and Boche D: Inflammatory components in human Alzheimer’s disease and after active amyloid-β42 immunization. Brain. 136:2677–2696. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Kaushal V, Dye R, Pakavathkumar P, Foveau B, Flores J, Hyman B, Ghetti B, Koller BH and LeBlanc AC: Neuronal NLRP1 inflammasome activation of Caspase-1 coordinately regulates inflammatory interleukin-1-beta production and axonal degeneration-associated Caspase-6 activation. Cell Death Differ. 22:1676–1686. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang B, Zhang Y, Xu T, Yin Y, Huang R, Wang Y, Zhang J, Huang D and Li W: Chronic dexamethasone treatment results in hippocampal neurons injury due to activate NLRP1 inflam-masome in vitro. Int Immunopharmacol. 49:222–230. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Faustin B, Lartigue L, Bruey JM, Luciano F, Sergienko E, Bailly-Maitre B, Volkmann N, Hanein D, Rouiller I and Reed JC: Reconstituted NALP1 inflammasome reveals two-step mechanism of caspase-1 activation. Mol Cell. 25:713–724. 2007. View Article : Google Scholar : PubMed/NCBI | |
|
Mawhinney LJ, de Rivero Vaccari JP, Dale GA, Keane RW and Bramlett HM: Heightened inflammasome activation is linked to age-related cognitive impairment in fischer 344 rats. BMC Neurosci. 12:1232011. View Article : Google Scholar : PubMed/NCBI | |
|
Choi AJ and Ryter SW: Inflammasomes: Molecular regulation and implications for metabolic and cognitive diseases. Mol Cells. 37:441–448. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Moon JS, Nakahira K, Chung KP, DeNicola GM, Koo MJ, Pabón MA, Rooney KT, Yoon JH, Ryter SW, Stout-Delgado H and Choi AM: NOX4-dependent fatty acid oxidation promotes NLRP3 inflammasome activation in macrophages. Nat Med. 22:1002–1012. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Yang L, Zhang J, Zheng K, Shen H and Chen X: Long-term ginsenoside Rg1 supplementation improves age-related cognitive decline by promoting synaptic plasticity associated protein expression in C57BL/6J mice. J Gerontol A Biol Sci Med Sci. 69:282–294. 2014. View Article : Google Scholar | |
|
Sun XC, Ren XF, Chen L, Gao XQ, Xie JX and Chen WF: Glucocorticoid receptor is involved in the neuroprotective effect of ginsenoside Rg1 against inflammation-induced dopaminergic neuronal degeneration in substantia nigra. J Steroid Biochem Mol Biol. 155:94–103. 2016. View Article : Google Scholar | |
|
Attele AS, Wu JA and Yuan CS: Ginseng pharmacology: Multiple constituents and multiple actions. Biochem Pharmacol. 58:1685–1693. 1999. View Article : Google Scholar : PubMed/NCBI | |
|
Zhu J, Mu X, Zeng J, Xu C, Liu J, Zhang M, Li C, Chen J, Li T and Wang Y: Ginsenoside Rg1 prevents cognitive impairment and hippocampus senescence in a rat model of D-galactose-induced aging. PLoS One. 9:e1012912014. View Article : Google Scholar : PubMed/NCBI | |
|
Zhu G, Wang Y, Li J and Wang J: Chronic treatment with ginsenoside Rg1 promotes memory and hippocampal long-term potentiation in middle-aged mice. Neuroscience. 292:81–89. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Wang Y, Kan H, Yin Y, Wu W, Hu W, Wang M and Li W and Li W: Protective effects of ginsenoside Rg1 on chronic restraint stress induced learning and memory impairments in male mice. Pharmacol Biochem Behav. 120:73–81. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang Y, Hu W, Zhang B, Yin Y, Zhang J, Huang D, Huang R and Li W and Li W: Ginsenoside Rg1 protects against neuronal degeneration induced by chronic dexamethasone treatment by inhibiting NLRP-1 inflammasomes in mice. Int J Mol Med. 40:1134–1142. 2017. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang B, Zhang Y, Wu W, Xu T, Yin Y, Zhang J, Huang D and Li W: Chronic glucocorticoid exposure activates BK-NLRP1 signal involving in hippocampal neuron damage. J Neuroinflammation. 14:1392017. View Article : Google Scholar : PubMed/NCBI | |
|
Cao G, Xiao M, Sun F, Xiao X, Pei W, Li J, Graham SH, Simon RP and Chen J: Cloning of a novel Apaf-1-interacting protein: A potent suppressor of apoptosis and ischemic neuronal cell death. J Neurosci. 24:6189–6201. 2004. View Article : Google Scholar : PubMed/NCBI | |
|
Hu W, Zhang Y, Wu W, Yin Y, Huang D, Wang Y and Li W and Li W: Chronic glucocorticoids exposure enhances neurodegeneration in the frontal cortex and hippocampus via NLRP-1 inflammasome activation in male mice. Brain Behav Immun. 52:58–70. 2016. View Article : Google Scholar | |
|
Kazama K, Anrather J, Zhou P, Girouard H, Frys K, Milner TA and Iadecola C: Angiotensin II impairs neurovascular coupling in neocortex through NADPH oxidase-derived radicals. Circ Res. 95:1019–1026. 2004. View Article : Google Scholar : PubMed/NCBI | |
|
Cheng XL and Zhang JJ: Effect of edaravone on apoptosis of hippocampus neuron in seizures rats kindled by pentylenetetrazole. Eur Rev Med Pharmacol Sci. 18:769–774. 2014.PubMed/NCBI | |
|
Dong W, Cheng S, Huang F, Fan W, Chen Y, Shi H and He H: Mitochondrial dysfunction in long-term neuronal cultures mimics changes with aging. Med Sci Monit. 17:BR91–BR96. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Quintanilla RA, Orellana JA and von Bernhardi R: Understanding risk factors for Alzheimer’s disease: Interplay of neuroinflammation, connexin-based communication and oxidative stress. Arch Med Res. 43:632–644. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Cahill-Smith S and Li JM: Oxidative stress, redox signalling and endothelial dysfunction in ageing-related neurodegenerative diseases: A role of NADPH oxidase 2. Br J Clin Pharmacol. 78:441–453. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Lee KW, Woo JM, Im JY, Park ES, He L, Ichijo H, Junn E and Mouradian MM: Apoptosis signal-regulating kinase 1 modulates the phenotype of α-synuclein transgenic mice. Neurobiol Aging. 36:519–526. 2015. View Article : Google Scholar | |
|
Verri M, Pastoris O, Dossena M, Aquilani R, Guerriero F, Cuzzoni G, Venturini L, Ricevuti G and Bongiorno AI: Mitochondrial alterations, oxidative stress and neuroinflammation in Alzheimer’s disease. Int J Immunopathol Pharmacol. 25:345–353. 2012. View Article : Google Scholar : PubMed/NCBI | |
|
Zhou X, Su CF, Zhang Z, Wang CY, Luo JQ, Zhou XW, Cai L, Yan L, Zhang W and Luo HM: Neuroprotective effects of methyl 3,4-dihydroxybenzoate against H(2)O(2)-induced apoptosis in RGC-5 cells. J Pharmacol Sci. 125:51–58. 2014. View Article : Google Scholar | |
|
Ong WY, Farooqui T, Koh HL, Farooqui AA and Ling EA: Protective effects of ginseng on neurological disorders. Front Aging Neurosci. 7:1292015. View Article : Google Scholar : PubMed/NCBI | |
|
Wang Y, Liu Q, Xu Y, Zhang Y, Lv Y, Tan Y, Jiang N, Cao G, Ma X, Wang J, et al: Ginsenoside rg1 protects against oxidative stress-induced neuronal apoptosis through myosin IIA-actin related cytoskeletal reorganization. Int J Biol Sci. 12:1341–1356. 2016. View Article : Google Scholar : PubMed/NCBI | |
|
Liu Q, Kou JP and Yu BY: Ginsenoside Rg1 protects against hydrogen peroxide-induced cell death in PC12 cells via inhibiting NF-kB activation. Neurochem Int. 58:119–125. 2011. View Article : Google Scholar | |
|
Aksu U, Yanar K, Terzioglu D, Erkol T, Ece E, Aydin S, Uslu E and Çakatay U: Effect of tempol on redox homeostasis and stress tolerance in mimetically aged drosophila. Arch Insect Biochem Physiol. 87:13–25. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Dugan LL, Ali SS, Shekhtman G, Roberts AJ, Lucero J, Quick KL and Behrens MM: IL-6 mediated degeneration of forebrain GABAergic interneurons and cognitive impairment in aged mice through activation of neuronal NADPH oxidase. PLoS One. 4:e55182009. View Article : Google Scholar : PubMed/NCBI | |
|
Tammariello SP, Quinn MT and Estus S: NADPH oxidase contributes directly to oxidative stress and apoptosis in nerve growth factor-deprived sympathetic neurons. J Neurosci. 20:RC532000. View Article : Google Scholar : PubMed/NCBI | |
|
DeLeo FR and Quinn MT: Assembly of the phagocyte NADPH oxidase: Molecular interaction of oxidase proteins. J Leukoc Biol. 60:677–691. 1996. View Article : Google Scholar : PubMed/NCBI | |
|
Ali SS, Young JW, Wallace CK, Gresack J, Jeste DV, Geyer MA, Dugan LL and Risbrough VB: Initial evidence linking synaptic superoxide production with poor short-term memory in aged mice. Brain Res. 1368:65–70. 2011. View Article : Google Scholar : | |
|
Walder CE, Green SP, Darbonne WC, Mathias J, Rae J, Dinauer MC, Curnutte JT and Thomas GR: Ischemic stroke injury is reduced in mice lacking a functional NADPH oxidase. Stroke. 28:2252–2258. 1997. View Article : Google Scholar : PubMed/NCBI | |
|
Xu YZ, Nygard M, Kristensson K and Bentivoglio M: Regulation of cytokine signaling and T-cell recruitment in the aging mouse brain in response to central inflammatory challenge. Brain Behav Immun. 24:138–152. 2010. View Article : Google Scholar | |
|
Glass CK, Saijo K, Winner B, Marchetto MC and Gage FH: Mechanisms underlying inflammation in neurodegeneration. Cell. 140:918–934. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Zou P, Liu X, Li G and Wang Y: Resveratrol pretreatment attenuates traumatic brain injury in rats by suppressing NLRP3 inflammasome activation via SIRT1. Mol Med Rep. 17:3212–3217. 2018. | |
|
Yin Y, Yan Y, Jiang X, Mai J, Chen NC, Wang H and Yang XF: Inflammasomes are differentially expressed in cardiovascular and other tissues. Int J Immunopathol Pharmacol. 22:311–322. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Tan CC, Zhang JG, Tan MS, Chen H, Meng DW, Jiang T, Meng XF, Li Y, Sun Z, Li MM, et al: NLRP1 inflammasome is activated in patients with medial temporal lobe epilepsy and contributes to neuronal pyroptosis in amygdala kindling-induced rat model. J Neuroinflammation. 12:182015. View Article : Google Scholar : PubMed/NCBI | |
|
Fann DY, Lee SY, Manzanero S, Tang SC, Gelderblom M, Chunduri P, Bernreuther C, Glatzel M, Cheng YL, Thundyil J, et al: Intravenous immunoglobulin suppresses NLRP1 and NLRP3 inflammasome-mediated neuronal death in ischemic stroke. Cell Death Dis. 4:e7902013. View Article : Google Scholar : PubMed/NCBI | |
|
Aminzadeh M, Roghani M, Sarfallah A and Riazi GH: TRPM2 dependence of ROS-induced NLRP3 activation in Alzheimer’s disease. Int Immunopharmacol. 54:78–85. 2018. View Article : Google Scholar |
