scholarly journals Nrf2 Regulates Microglia-Mediated Phagocytosis and Neuroinflammation Following Intracerebral Hemorrhage

Author(s):  
Lirong Liu ◽  
Shuangjin Bao ◽  
Zhenjia Yao ◽  
Qinqin Bai ◽  
Chuntian Liang ◽  
...  

Abstract Background To explore the effect of microglial functional transformation in hematoma clearance following intracerebral hemorrhage (ICH), and investigate whether Nuclear factor erythroid 2-related factor 2 (Nrf2) -mediated microglial phagocytosis and inflammatory response is beneficial for hematoma clearance and functional recovery in vitro and in vivo experiments after ICH. Methods In vitro experiments, BV-2 cells were cultured and randomly divided into 4 groups: normal control, microglia + Nrf2-siRNA (100 nmol/L), microglia + monascin (15 µM), microglia + Xuezhikang (200 µg/mL). In vivo experiments, 42 mice were divided into sham, ICH+vehicle, ICH+Nrf2-/-, ICH+monascin (10mg/kg/day, twice) and ICH+Xuezhikang (0.2g/kg/day, twice). Neurologic scores, hemoglobin levels, microglial phagocytosis, brain expression of CD80 /Trem1/TNF-α (pro-inflammatory cytokines) as well as CD206/Trem2/BDNF (anti-inflammatory cytokines) were analyzed at 72 hours after surgery. Results The results showed that Nrf2 agonists improved neurological deficits and decreased hemoglobin levels after ICH. The administration of Nrf2 agonist- monascin/ Xuezhikang enhanced microglia-mediated phagocytosis of erythrocytes and bioparticles by up-regulating Nrf2. Alternatively, monascin/Xuezhikang promoted the expressions of Triggering receptor II expressed on myeloid cells (Trem2), CD206 and BDNF, while inhibited the expressions of Trem1,CD80 and TNF-αexpressed in microglia. Conversely, Nrf2 inhibition (Nrf2 siRNA or Nrf2-/-) showed the opposite results following ICH. Conclusions Microglial functional transformation are involved in hematoma clearance following ICH. Nrf2 activation contributes to microglial functional transformation and phagocytic responses then exerts its neuroprotection after ICH. Nrf2 activator (Monascin/Xuezhikang) enhances hematoma clearance and alleviates neuroinflammation via the regulation of microglial functional alteration following ICH.

2021 ◽  
Vol 22 (8) ◽  
pp. 3995
Author(s):  
Cheong-Yong Yun ◽  
Nahyun Choi ◽  
Jae Un Lee ◽  
Eun Jung Lee ◽  
Ji Young Kim ◽  
...  

Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.


2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Anna K Gazha ◽  
Lyudmila A. Ivanushko ◽  
Eleonora V. Levina ◽  
Sergey N. Fedorov ◽  
Tatyana S. Zaporozets ◽  
...  

The action of seven polyhydroxylated sterol mono- and disulfates (1-7), isolated from ophiuroids, on innate and adaptive immunity was examined in in vitro and in vivo experiments. At least, three of them (1, 2 and 4) increased the functional activities of neutrophils, including levels of oxygen-dependent metabolism, adhesive and phagocytic properties, and induced the expression of pro-inflammatory cytokines TNF-α and IL-8. Compound 4 was the most active for enhancing the production of antibody forming cells in the mouse spleen.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Hailong Yu ◽  
Xiang Cao ◽  
Wei Li ◽  
Pinyi Liu ◽  
Yuanyuan Zhao ◽  
...  

Abstract Background In the central nervous system (CNS), connexin 43 (Cx43) is mainly expressed in astrocytes and regulates astrocytic network homeostasis. Similar to Cx43 overexpression, abnormal excessive opening of Cx43 hemichannels (Cx43Hcs) on reactive astrocytes aggravates the inflammatory response and cell death in CNS pathologies. However, the role of excessive Cx43Hc opening in intracerebral hemorrhage (ICH) injury is not clear. Methods Hemin stimulation in primary cells and collagenase IV injection in C57BL/6J (B6) mice were used as ICH models in vitro and in vivo. After ICH injury, the Cx43 mimetic peptide Gap19 was used for treatment. Ethidium bromide (EtBr) uptake assays were used to measure the opening of Cx43Hcs. Western blotting and immunofluorescence were used to measure protein expression. qRT-PCR and ELISA were used to determine the levels of cytokines. Coimmunoprecipitation (Co-IP) and the Duolink in situ proximity ligation assay (PLA) were applied to measure the association between proteins. Results In this study, Cx43 expression upregulation and excessive Cx43Hc opening was observed in mice after ICH injury. Delayed treatment with Gap19 significantly alleviated hematoma volume and neurological deficits after ICH injury. In addition, Gap19 decreased inflammatory cytokine levels in the tissue surrounding the hematoma and decreased reactive astrogliosis after ICH injury in vitro and in vivo. Intriguingly, Cx43 transcriptional activity and expression in astrocytes were significantly increased after hemin stimulation in culture. However, Gap19 treatment downregulated astrocytic Cx43 expression through the ubiquitin-proteasome pathway without affecting Cx43 transcription. Additionally, our data showed that Gap19 increased Yes-associated protein (YAP) nuclear translocation. This subsequently upregulated SOCS1 and SOCS3 expression and then inhibited the TLR4-NFκB and JAK2-STAT3 pathways in hemin-stimulated astrocytes. Finally, the YAP inhibitor, verteporfin (VP), reversed the anti-inflammatory effect of Gap19 in vitro and almost completely blocked its protective effects in vivo after ICH injury. Conclusions This study provides new insight into potential treatment strategies for ICH injury involving astroglial Cx43 and Cx43Hcs. Suppression of abnormal astroglial Cx43 expression and Cx43Hc opening by Gap19 has anti-inflammatory and neuroprotective effects after ICH injury.


Stroke ◽  
2020 ◽  
Vol 51 (2) ◽  
pp. 612-618 ◽  
Author(s):  
Che-Feng Chang ◽  
Jordan Massey ◽  
Artem Osherov ◽  
Luís Henrique Angenendt da Costa ◽  
Lauren H. Sansing

Background and Purpose— Enhancement of erythrophagocytosis by macrophages in a timely manner can limit the toxic effects of erythrocyte metabolites and promote brain recovery after intracerebral hemorrhage (ICH). In the current study, we investigated the therapeutic effect of retinoid X receptor agonist, bexarotene, in facilitating erythrophagocytosis and neurobehavioral recovery in 2 mouse models of ICH. Methods— Bone marrow-derived macrophages and fluorescently labeled erythrocytes were used to study erythrophagocytosis in vitro with phenotypic changes quantified by gene expression. ICH was modeled in vivo using intrastriatal autologous blood and collagenase injection in mice with and without bexarotene treatment beginning 3 hours after ICH. In vivo phagocytosis, ability and hematoma clearance were evaluated by erythrophagocytosis assays, flow cytometry, and histological analysis. Neurological deficits and functional recovery were also quantified. Results— Bexarotene increased macrophage expression of phagocytosis receptors and erythrophagocytosis and reduced macrophage TNF (tumor necrosis factor) production in vitro. In vivo, bexarotene treatment enhanced erythrophagocytosis, reduced hematoma volume, and ultimately improved neurological recovery after ICH in 2 distinct models of ICH. Conclusions— Bexarotene administration is beneficial for recovery after ICH by enhancing hemorrhage phagocytosis, modulating macrophage phenotype, and improving functional recovery.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhongmei Wen ◽  
Weichen Hou ◽  
Wei Wu ◽  
Yang Zhao ◽  
Xuechao Dong ◽  
...  

6′-O-galloylpaeoniflorin (GPF), a galloylated derivative of paeoniflorin isolated from peony root, has been proven to possess antioxidant potential. In this present study, we revealed that GPF treatment exerted significant neuroprotection of PC12 cells following OGD, as evidenced by a reduction of oxidative stress, inflammatory response, cellular injury, and apoptosis in vitro. Furthermore, treatment with GPF increased the levels of phosphorylated Akt (p-Akt) and nuclear factor-erythroid 2-related factor 2 (Nrf2), as well as promoted Nrf2 translocation in PC12 cells, which could be inhibited by Ly294002, an inhibitor of phosphoinositide 3-kinase (PI3K). In addition, Nrf2 knockdown or Ly294002 treatment significantly attenuated the antioxidant, anti-inflammatory, and antiapoptotic activities of GPF in vitro. In vivo studies indicated that GPF treatment significantly reduced infarct volume and improved neurological deficits in rats subjected to CIRI, as well as decreased oxidative stress, inflammation, and apoptosis, which could be inhibited by administration of Ly294002. In conclusion, these results revealed that GPF possesses neuroprotective effects against oxidative stress, inflammation, and apoptosis after ischemia-reperfusion insult via activation of the PI3K/Akt/Nrf2 pathway.


2020 ◽  
Author(s):  
Hailong Yu ◽  
Xiang Cao ◽  
Wei Li ◽  
Pinyi Liu ◽  
Yuanyuan Zhao ◽  
...  

Abstract Background: In the central nervous system(CNS),Connexin43 (Cx43) is mainly expressed in astrocytes and regulates astrocytic network homeostasis. Like Cx43 overexpression,abnormal excessive opening of Cx43 hemichannels (Cx43Hcs) on reactive astrocytes aggravates the inflammatory response and cell death in CNS pathologies.However, the role of excessive Cx43Hc opening in intracerebral hemorrhage (ICH) injury is not clear.Methods: Hemin stimulation in primary cells and collagenase IV injection in C57BL/6J (B6) mice were used as ICH modals in vitro and vivo.Cx43 mimetic peptide Gap19 was treated after ICH injury. Ethidium bromide (EtBr) uptake assays was used to measure the opening of Hcs. Western blot and immunofluorescence were used to measure the expression of protein. qRT-PCR and ELISA were used to determine the level of cytokines. Co-immunoprecipitation(Co-IP) and Duolink in situ proximity ligation assay (PLA) were applied to measure the association between proteins.Results: In this study,Cx43 expression was upregulated, and excessive Cx43Hc opening was observed in mice after ICH injury. Delayed treatment with Gap19significantly alleviated hematoma volume and neurological deficits after ICH injury. In addition,Gap19 decreased inflammatory cytokine levels in the tissue surrounding the hematoma and decreased reactive astrogliosis after ICH injury in vitro and in vivo, as determined by GFAP staining. Intriguingly, Cx43 transcriptional activity and expression in astrocytes were significantly increased after hemin stimulation in culture.However,Gap19 treatment downregulated astrocytic Cx43 expression through the ubiquitin-proteasome pathway without affecting Cx43 transcription. Additionally, our data showed that Gap19 increased YAP nuclear translocation, which upregulated SOCS1 and SOCS3 expression, and then inhibited the TLR4-NFκB and JAK2-STAT3 pathways in hemin-stimulated astrocytes. Finally, the YAP inhibitor verteporfin (VP) reversed the anti-inflammatory effect of Gap19 in vitro and almost completely blocked its protective effects in vivo after ICH injury.Conclusions: This study provides new insight into potential treatment strategies for ICH injury involving astroglial Cx43 and Cx43Hcs.Suppression of abnormal astroglial Cx43 expression and Cx43Hc opening by Gap19 plays anti-inflammatory and neuroprotective roles after ICH injury.


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 411
Author(s):  
Nader Kameli ◽  
Anya Dragojlovic-Kerkache ◽  
Paul Savelkoul ◽  
Frank R. Stassen

In recent years, plant-derived extracellular vesicles (PDEVs) have gained the interest of many experts in fields such as microbiology and immunology, and research in this field has exponentially increased. These nano-sized particles have provided researchers with a number of interesting findings, making their application in human health and disease very promising. Both in vitro and in vivo experiments have shown that PDEVs can exhibit a multitude of effects, suggesting that these vesicles may have many potential future applications, including therapeutics and nano-delivery of compounds. While the preliminary results are promising, there are still some challenges to face, such as a lack of protocol standardization, as well as knowledge gaps that need to be filled. This review aims to discuss various aspects of PDEV knowledge, including their preliminary findings, challenges, and future uses, giving insight into the complexity of conducting research in this field.


2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.


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