scholarly journals Neuroprotective Effects of Hesperetin in Regulating Microglia Polarization after Ischemic Stroke by Inhibiting TLR4/NF-κB Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jiawen Zhang ◽  
Hao Jiang ◽  
Fang Wu ◽  
Xiaofei Chi ◽  
Yu Pang ◽  
...  

This study aimed to explore the influence of hesperidin on the polarization of microglia to clarify the key mechanism of regulating the polarization of M2 microglia. C57BL/6 mice were randomly divided into middle cerebral artery occlusion model group (MCAO group), MCAO + hesperidin treatment group (MCAO + hesperidin group), and sham group (sham operation group). The mice were assessed with neurological scores for their functional status. 2,3,5-Triphenyltetrazole chloride (TTC) was used to determine the volume of cerebral infarction. Hematoxylin and eosin (H&E) staining was performed to detect brain loss. The system with 1% O2, 5% CO2, and 92% N2 was applied to establish BV2 in vitro model induced by MCAO. TNF-α, IL-1β, TGF-β, and IL-10 levels of cytokines in the supernatant were detected by ELISA. RT-qPCR was used to detect mRNA levels of M1 iNOS, CD11b, CD32, and CD86, and mRNA levels of M2 CD206, Arg-1, and TGF-β. The Iba-1, iNOS, and Arg-1 of microglia and protein levels of TLR4 and p-NF-κB related to the pathway were detected by Western blot. After treatment with hesperidin, BV2 cells induced by MCAO in vitro can reduce the proinflammatory cytokines of TNF-α and IL-1β significantly, further upregulating anti-inflammatory cytokines of TGF-β, IL-10 while inhibiting TLR4 and p-NF-κB expression. The MCAO-induced BV2 cells treated by TLR-4 inhibitor TAK-242 and NF-κB inhibitor BAY 11-7082 had similar polarization effects to those treated with hesperidin. This study found that hesperetin gavage treatment can improve the neurological deficit and regulate the polarization of microglia in MCAO mice. In vitro experiments further verified that hesperidin plays a neuroprotective role by inhibiting the TLR4-NF-κB pathway, thus providing new targets and strategies for neuroprotection and nerve repair after ischemic stroke.

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Yan Xu ◽  
Yue Zhang

Abstract Background and Aims Ischemia-reperfusion injury (IRI) is the outcome of an inflammatory process and tubular cell death that is triggered by undergoing a transient reduction or cessation of blood flow and following by reperfusion. Unresolved IRI can contribute to chronic kidney disease even death. Our aims is to investigate the protective effect of hyperin on ischemia-reperfusion renal injury (IRI) and its possible mechanism. Method ① The transcriptome chip data of multiple IRI models were selected from the NCBI GEO DateSets database and a number of key proteins that could participate in IRI were screened out (the fold increase was greater than 2 fold and was statistically significant). Network and transcript binding motif analysis was performed to determine the best binding protein. ② C57BL / 6J mice were selected and randomly divided into normal group, sham operation group, IRI group (bilateral renal pedicle clamping for 45min), hyperin + IRI group (50mg / kg.d per day, 7 days before surgery ), DMSO + IRI group (7 days before the operation, the same amount of DMSO was administered to the stomach every day, and the operation was the same as AKI), with 6 rats in each group. Renal tissue and blood were collected 24 hours after operation for testing. ③ In vitro experiments, human proximal tubule epithelial cells (HK-2) were selected and divided into hypoxia 3, 6, 9, 12, 24, 36, and 48h for reoxygenation of 1, 3, and 6h respectively. Relevant indicators for RT-PCR detection were determined Optimal hypoxia time. The drug safe concentration was selected according to 0, 5, 10, 25, 50, 100, 200, 400 μg / ml hyperin pre-treatment for 12 hours, and the CCK8 reagent was added for 2 hours to measure the absorbance at 450 nm. The cells were randomly divided into normal group, hypoxia group, hypoxia + DMSO group, hypoxia + hyperin group, and related indexes were detected by RT-PCR and Western Blot. ④ Obtain the tertiary structure of the protein and the three-dimensional structure of the hyperin molecule from the RCSB Protein Data Bank website and the PubChem compound database, and use molecular docking technology to determine the proteins that can bind to hyperin using autodock software and analyze their binding ability. Results Bioinformatics analysis suggested that STK40 protein is one of the key factors of IRI and may be a target for preventing and treating diseases. In vivo experiments showed that compared with the normal group and the sham operation group, the levels of serum creatinine, blood urea nitrogen, and kim-1 in rats were significantly increased after AKI, and HE staining of pathological sections showed an increase in renal tubular injury scores. Significantly decreased (P<0.05); RT-PCR results showed that kim-1, caspase-3, NF-κB, IL-6, TNF-α increased significantly after AKI, STK40, Bcl2 / BAX decreased, and the above after hyperin The indicators changed in opposite directions (P <0.05). In vitro experiments: The best time for hypoxia is 24h hypoxia + 1h reoxygenation; compared with the control group, the drug concentration is <100 μg / mL and the cell proliferation activity rate is> 90%, so the hyperin concentration was selected as 50 μg / mL (P < 0.05); RT-PCR results showed that Hif1-α, caspase-3, NF-κB, IL-6, TNF-α significantly increased, and STK40, Bcl2 / BAX decreased compared with the normal group. After administration of hyperin, the above indexes changed in opposite directions (P <0.05). Conclusion In this study, using molecular docking technology and constructing IRI mice model, it was confirmed that hyperin can reduce IRI and exert a protective effect on IRI by inhibiting STK40 expression.


2021 ◽  
Vol 118 (32) ◽  
pp. e2018850118
Author(s):  
Hiroo Takahashi ◽  
Ryo Asahina ◽  
Masayuki Fujioka ◽  
Takeshi K. Matsui ◽  
Shigeki Kato ◽  
...  

Ischemic stroke, which results in loss of neurological function, initiates a complex cascade of pathological events in the brain, largely driven by excitotoxic Ca2+ influx in neurons. This leads to cortical spreading depolarization, which induces expression of genes involved in both neuronal death and survival; yet, the functions of these genes remain poorly understood. Here, we profiled gene expression changes that are common to ischemia (modeled by middle cerebral artery occlusion [MCAO]) and to experience-dependent activation (modeled by exposure to an enriched environment [EE]), which also induces Ca2+ transients that trigger transcriptional programs. We found that the activity-dependent transcription factor Npas4 was up-regulated under MCAO and EE conditions and that transient activation of cortical neurons in the healthy brain by the EE decreased cell death after stroke. Furthermore, both MCAO in vivo and oxygen-glucose deprivation in vitro revealed that Npas4 is necessary and sufficient for neuroprotection. We also found that this protection involves the inhibition of L-type voltage-gated Ca2+ channels (VGCCs). Next, our systematic search for Npas4-downstream genes identified Gem, which encodes a Ras-related small GTPase that mediates neuroprotective effects of Npas4. Gem suppresses the membrane localization of L-type VGCCs to inhibit excess Ca2+ influx, thereby protecting neurons from excitotoxic death after in vitro and in vivo ischemia. Collectively, our findings indicate that Gem expression via Npas4 is necessary and sufficient to promote neuroprotection in the injured brain. Importantly, Gem is also induced in human cerebral organoids cultured under an ischemic condition, revealing Gem as a new target for drug discovery.


2020 ◽  
Author(s):  
Song Wenjun ◽  
Tiancheng Wang ◽  
Bei Shi ◽  
Zhijun Wu ◽  
Wenjie Wang ◽  
...  

Abstract Background and aim: Ischemic stroke is one of the main causes of death worldwide and permanent global disability. On the basis of existing literature data, we carried out studies in an effort to explore how miR-140-5p affects ischemic stroke and whether the mechanism relates to toll-like receptor-4 (TLR4) and nuclear factor-kappa B (NF-κB).Methods: Middle cerebral artery occlusion (MCAO) was employed to establish a mouse model of ischemic stroke in vivo, while primary neurons were exposed to oxygen-glucose deprivation (OGD) to set up an ischemic stroke model in vitro. RT-qPCR was performed to detect the miR-140-5p expression and Western blot was employed to detect the expression TLR4, NF-κB, and apoptosis-related factors. Then, based gain-function of experiments using miR-140-5p mimic and TLR4 overexpression plasmid, neurological function score, TTC staining, TUNEL staining, as well as flow cytometry were carried out to evaluate the effects of miR-140-5p and TLR4 on MCAO mice and OGD neurons. Meanwhile, dual-luciferase reporter assay was used to validate the relationship between miR-140-5p and TLR4.Results: miR-140-5p expressed at a low level and TLR4 at a high level in ischemic stroke. It was verified that miR-140-5p targeted TLR4 and downregulated its expression. miR-140-5p overexpression was observed to inhibit the apoptosis of neurons under OGD exposure and restrain the progression of ischemic stroke, while TLR4 overexpression promoted the apoptosis and disease progression. Besides, miR-140-5p overexpression led to a decrease in NF-κB protein level, which was increased by TLR4 overexpression. Conclusion: In conclusion, from our data we conclude that miR-140-5p overexpression may be instrumental for the therapeutic targeting of ischemic stroke by alleviating neuron injury with the involvement of TLR4/NF-κB axis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ni Wang ◽  
Changyi Fei ◽  
Furui Chu ◽  
Shi Huang ◽  
Lingyu Pan ◽  
...  

Cell necrosis and neuroinflammation play an important role in brain injury induced by ischemic stroke. Previous studies reported that Taohong Siwu decoction (THSWD)can reduce heart muscle cell necrosis and has anti-inflammatory properties. In this study, we investigated the effects of THSWD on cell necrosis and neuroinflammation in a rat model of middle cerebral artery occlusion (MCAO). Thirty-six male Sprague-Dawley (SD) rats were randomly divided into three groups with 12 rats in each group. They were the sham operation group, MCAO model group, and MCAO + THSWD group. We used ELISA to determine the levels of TNF-α, Mcp-1, and IL-1β inflammatory factors in rat serum, qRT‐PCR to detect the expression of TNF‐α, Mcp‐1 and IL‐1β mRNA in rat brain, and immunohistochemistry to detect the number of microglia and neutrophils in rat brain. qRT-PCR and Western blot were used to detect the mRNA and protein expression levels of IBA-1 and MPO inflammatory factors and the TNF-α/RIP1/RIP3/MLKL pathway in the rat brain and protein expression levels. Compared with the sham operation group, the expression of MCP-1, IL-1β, IBA-1, and MPO inflammatory factors and the TNF-α/RIP1/RIP3/MLKL pathway were significantly upregulated in the MCAO group. Compared with the MCAO group, the expressions of MCP-1, IL-1β, IBA-1, and MPO inflammatory factors and the TNF-α/RIP1/RIP3/MLKL pathway were significantly downregulated in the MCAO + THSWD group. THSWD can reduce the expression levels of MCP-1, IL-1β, IBA-1, and MPO inflammatory factors as well as the TNF-α/RIP1/RIP3/MLKL pathway. Meanwhile, it can reduce the necrosis and inflammation of brain cells after cerebral ischemia, so as to protect the brain tissue of rats.


2009 ◽  
Vol 78 (3) ◽  
pp. 1012-1021 ◽  
Author(s):  
Rosane M. B. Teles ◽  
Rose B. Teles ◽  
Thais P. Amadeu ◽  
Danielle F. Moura ◽  
Leila Mendonça-Lima ◽  
...  

ABSTRACT Gelatinases A and B (matrix metalloproteinase 2 [MMP-2] and MMP-9, respectively) can induce basal membrane breakdown and leukocyte migration, but their role in leprosy skin inflammation remains unclear. In this study, we analyzed clinical specimens from leprosy patients taken from stable, untreated skin lesions and during reactional episodes (reversal reaction [RR] and erythema nodosum leprosum [ENL]). The participation of MMPs in disease was suggested by (i) increased MMP mRNA expression levels in skin biopsy specimens correlating with the expression of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), (ii) the detection of the MMP protein and enzymatic activity within the inflammatory infiltrate, (iii) increased MMP levels in patient sera, and (iv) the in vitro induction of MMP-9 by Mycobacterium leprae and/or TNF-α. It was observed that IFN-γ, TNF-α, MMP-2, and MMP-9 mRNA levels were higher in tuberculoid than lepromatous lesions. In contrast, interleukin-10 and tissue inhibitor of MMP (TIMP-1) message were not differentially modulated. These data correlated with the detection of the MMP protein evidenced by immunohistochemistry and confocal microscopy. When RR and ENL lesions were analyzed, an increase in TNF-α, MMP-2, and MMP-9, but not TIMP-1, mRNA levels was observed together with stronger MMP activity (zymography/in situ zymography). Moreover, following in vitro stimulation of peripheral blood cells, M. leprae induced the expression of MMP-9 (mRNA and protein) in cultured cells. Overall, the present data demonstrate an enhanced MMP/TIMP-1 ratio in the inflammatory states of leprosy and point to potential mechanisms for tissue damage. These results pave the way toward the application of new therapeutic interventions for leprosy reactions.


2021 ◽  
Author(s):  
Maximilian Wilmes ◽  
Carolina Pinto Espinoza ◽  
Peter Ludewig ◽  
Arthur Liesz ◽  
Annette Nicke ◽  
...  

Abstract BackgroundPrevious studies have demonstrated that purinergic receptors could be therapeutic targets to modulate the inflammatory response in multiple brain disease models. However, tools for the selective and efficient targeting of these receptors are scarce. The new development of P2X7-specific nanobodies (nbs) enables us to effectively block the P2X7-channel.MethodsTemporary middle cerebral artery occlusion (tMCAO) in wildtype and P2X7-transgenic mice was used as a model for ischemic stroke. ATP release was assessed in transgenic ATP sensor mice. Stroke size was measured without treatment and after injection of P2X7-specific nbs i.v. and i.c.v. directly before tMCAO-surgery. P2X7-GFP expressing transgenic mice were used to show immunhistochemically P2X7 distribution in the brain. In vitro cultured microglia were used to investigate calcium-influx, pore-formation via DAPI uptake, caspase 1 activation and IL-1b release after incubation with P2X7-specific nbs. ResultsATP sensor mice showed an increase of ATP-release in the ischemic hemisphere compared to the contralateral hemisphere or sham mice up to 24 h after stroke. We could further verify the role of the ATP-P2X7 axis in P2X7-overexpressing mice, which showed significantly greater stroke volumes after 24 h. In vitro experiments with primary microglia cells showed that P2X7-specific nanobodies were capable of dampening the ATP-trigged calcium-influx and formation of membrane pores measured by Fluo4 fluorescence or DAPI uptake. We found a lower caspase 1 activity and a subsequently lower IL-1b release. However, the intravenous (i.v.) injection of P2X7-specific nanobodies compared to isotype controls before the tMCAO-surgery did not result in smaller stroke size compared to isotype controls. As demonstrated by FACS, nbs had only reached brain infiltrating macrophages but not microglia. To reach microglia, we injected the P2X7-spezific nbs or the isotype directly intraventricularly (icv). 30 mg of P2X7-specific nbs proved efficient for microglial targeting, reducing post-stroke microglia activation and stroke size significantly.ConclusionHere, we demonstrate the importance of locally produced ATP for the tissue damage observed in ischemic stroke and we show the potential of icv injected P2X7-specific nbs to reduce ischemic tissue damage.


2016 ◽  
Vol 38 (3) ◽  
pp. 1245-1256 ◽  
Author(s):  
Shuo Chen ◽  
Lei Zhang ◽  
Ruonan Xu ◽  
Yunfan Ti ◽  
Yunlong Zhao ◽  
...  

Background/Aims: The bradykinin B2 receptor (BDKRB2) +9/-9 gene polymorphisms have been shown to be associated with the susceptibility and severity of osteoarthritis (OA); however, the underlying mechanisms are unclear. In this study, we investigated the correlation between the BDKRB2 +9/-9 polymorphisms and pro-inflammatory cytokine levels in OA and the molecular mechanisms involved. Methods: A total of 156 patients with primary knee OA and 121 healthy controls were enrolled. The BDKRB2 +9/-9 polymorphisms were genotyped. The tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 levels were determined using Enzyme-linked immunosorbent assay (ELISA). The toll-like receptor (TLR)-2 and TLR-4 mRNA levels were determined by quantitative real-time PCR. The basal and bradykinin-stimulated pro-inflammatory cytokine secretion in human OA synoviocytes and the involvement of TLR-2 and mitogen-activated protein kinases (MAPKs) were investigated. Results: The presence of -9 bp genotype is associated with higher TNF-α, IL-6, and IL-8 levels and higher TLR-2 expression in OA patients. The basal and bradykinin-induced TLR-2 expressions in human OA synoviocytes were significantly reduced by specific inhibitors of p38, JNK1/2, and ERK1/2. Both the B2 receptor antagonist MEN16132 and TLR-2 silencing inhibited IL-6 and IL-8 secretion in human OA synoviocytes. Conclusion: The data suggested that the BDKRB2 +9/-9 polymorphisms influence pro-inflammatory cytokine levels in knee osteoarthritis by altering TLR-2 expression.


2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.


2020 ◽  
Author(s):  
Junyuan Wu ◽  
Zhiwei Li ◽  
Wei Yuan ◽  
Qiang Zhang ◽  
Yong Liang ◽  
...  

Abstract Background: The aim of this study was to clarify effects of Shenfu infusion (SFI) on cerebral microcirculation and brain injury after hemorrhagic shock (HS).Methods: Twenty-one domestic male Beijing Landrace pigs were randomly divided into three groups: SFI group (SFI, n=8), saline group (SA, n=8) or sham operation group (SO, n=5). In the SFI group, animals were induced to HS by rapid bleeding to a mean arterial pressure of 40 mmHg within 10 minutes and maintained at 40 ± 3 mmHg for 60 minutes. Volume resuscitation (shed blood and crystalloid) and SFI were given after 1 hour of HS. In the SA group, animals received the same dose of saline instead of SFI. In the SO group, the same surgical procedure was performed but without inducing HS and volume resuscitation. The cerebral microvascular flow index (MFI), nitric oxide synthase (NOS) expression, aquaporin-4 expression, interleukin 6, tumor necrosis factor-α (TNF-α) and ultrastructural of microvascular endothelia were measured.Results: Compared with the SA group, SFI significantly improved cerebral MFI after HS. SFI up regulated cerebral endothelial NOS expression, but down regulated interleukin 6, TNF-α, inducible NOS and aquaporin-4 expression compared with the SA group. The cerebral microvascular endothelial injury and interstitial edema in the SFI group were lighter than those in the SA group.Conclusions: Combined application of SFI with volume resuscitation after HS can improve cerebral microcirculation and reduce brain injury.


2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Jintao Gao ◽  
Fangru Chen ◽  
Huanan Fang ◽  
Jing Mi ◽  
Qi Qi ◽  
...  

Abstract Background Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms. Methods HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR. Results Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice. Conclusions Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.


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