scholarly journals FGF20 protected against BBB disruption after traumatic brain injury by activating the AKT/GSK3β pathway to upregulate junction protein expression and inhibiting JNK/NFκB-dependent neuroinflammation

2019 ◽  
Author(s):  
Jun Chen ◽  
Xue Wang ◽  
Jian Hu ◽  
Wenting Huang ◽  
Confidence Dordoe ◽  
...  

Abstract Background :Blood-brain barrier (BBB) disruption and the cerebral inflammatory response are two reciprocal mechanisms that work together to mediate the degree of brain edema, which is responsible for the majority of deaths after traumatic brain injury (TBI), and facilitate further brain damage, which leads to long-term TBI complications. Fibroblast growth factor 20 (FGF20), a neurotrophic factor, plays important roles in the development of dopaminergic neurons in Parkinson disease (PD). However, little is known about the role of FGF20 in TBI. The aim of the current study was to assess the protective effects of FGF20 in TBI through protecting the BBB. Methods: We explored the relationship between FGF20 and BBB function in controlled cortical impact (CCI)-induced TBI mice model and TNF-α-induced human brain microvascular endothelial cell (HBMEC) in vitro BBB disruption model. We also explored the mechanisms of these interactions and the signaling processes involved in BBB function and neuroinflammation. Results: In this study, we demonstrate that recombinant human FGF20 (rhFGF20) reduced neurofunctional deficits, brain edema and Evans Blue penetration in vivo after TBI. In an in vitro BBB disruption model of, rhFGF20 could reverse changes to TNF-α-induced HBMEC morphology, reduce Transwell permeability, and increase transendothelial electrical resistance (TEER). In both a TBI mouse model and in vitro , rhFGF20 upregulated the expression of BBB-associated tight junction (TJ) protein and adherens junction (AJ) protein via the AKT/GSK3β pathway. In addition, rhFGF20 inhibited the cerebral inflammatory response through regulating the JNK/NFκB pathway and further protected the function of the BBB. Conclusions : Our results contribute to a new treatment strategy in TBI research. FGF20 is a potential candidate to treat TBI as it protects the BBB via regulating the AKT/GSK3β and JNK/NFκB signaling pathways.

2021 ◽  
Vol 11 ◽  
Author(s):  
Jun Chen ◽  
Xue Wang ◽  
Jian Hu ◽  
Jingting Du ◽  
Confidence Dordoe ◽  
...  

Disruption of the blood-brain barrier (BBB) and the cerebral inflammatory response occurring after traumatic brain injury (TBI) facilitate further brain damage, which leads to long-term complications of TBI. Fibroblast growth factor 20 (FGF20), a neurotrophic factor, plays important roles in brain development and neuronal homeostasis. The aim of the current study was to assess the protective effects of FGF20 on TBI via BBB maintenance. In the present study, recombinant human FGF20 (rhFGF20) reduced neurofunctional deficits, brain edema, Evans blue extravasation and neuroinflammation in a TBI mouse model. In an in vitro TNF-α-induced human brain microvascular endothelial cell (HBMEC) model of BBB disruption, rhFGF20 reduced paracellular permeability and increased trans-endothelial electrical resistance (TEER). Both in the TBI mouse model and in vitro, rhFGF20 increased the expression of proteins composing in BBB-associated tight junctions (TJs) and adherens junctions (AJs), and decreased the inflammatory response, which protected the BBB integrity. Notably, rhFGF20 preserved BBB function by activating the AKT/GSK3β pathway and inhibited the inflammatory response by regulating the JNK/NFκB pathway. Thus, FGF20 is a potential candidate treatment for TBI that protects the BBB by upregulating junction protein expression and inhibiting the inflammatory response.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 478 ◽  
Author(s):  
Rasha Al-Rikabi ◽  
Hanady Al-Shmgani ◽  
Yaser Hassan Dewir ◽  
Salah El-Hendawy

(1) Background: Plant flavonoids are efficient in preventing and treating various diseases. This study aimed to evaluate the ability of hesperidin, a flavonoid found in citrus fruits, in inhibiting lipopolysaccharide (LPS) induced inflammation, which induced lethal toxicity in vivo, and to evaluate its importance as an antitumor agent in breast cancer. The in vivo experiments revealed the protective effects of hesperidin against the negative LPS effects on the liver and spleen of male mice. (2) Methods: In the liver, the antioxidant activity was measured by estimating the concentration of glutathione (GSH) and catalase (CAT), whereas in spleen, the concentration of cytokines including IL-33 and TNF-α was measured. The in vitro experiments including MTT assay, clonogenity test, and sulforhodamine 101 stain with DAPI (4′, 6-diamidino-2-phenylindole) were used to assess the morphological apoptosis in breast cancer cells. (3) Results: The results of this study revealed a significant increase in the IL-33 and TNF-α cytokine levels in LPS challenged mice along with a considerable elevation in glutathione (GSH); moreover, the catalase (CAT) level was higher compared to that of the control group. Cytotoxicity of the MCF-7 cell line revealed significant differences among the groups treated with different concentrations when compared to the control groups, in a concentration-dependent manner. Hesperidin significantly inhibited the colony formation of MCF7 cells when compared to that of control. Clear changes were observed in the cell shape, including cell shrinkage and chromatin condensation, which were associated with a later apoptotic stage. (4) Conclusion: The results indicate that hesperidin might be a potential candidate in preventing diseases.


2021 ◽  
Vol 8 ◽  
Author(s):  
Shengwei Chen ◽  
Yi Zhang ◽  
Xueting Niu ◽  
Sahar Ghulam Mohyuddin ◽  
Jiayin Wen ◽  
...  

Herein, we assessed the anti-inflammatory and intestinal barrier protective effects of butyrolactone-I (BTL-1), derived from the coral-derived endophytic fungus (Aspergillus terreus), using the LPS-induced IPEC-J2 inflammation model and the DSS-induced IBD model in mice. In IPEC-J2 cells, pretreatment with BTL-I significantly inhibited TLR4/NF-κB signaling pathway and JNK phosphorylation, resulting in the decrease of IL-1β and IL-6 expression. Interestingly, BTL-1 pretreatment activated the phosphorylation of ERK and P38, which significantly enhanced the expression of TNF-α. Meanwhile, BTL-1 pretreatment upregulated tight junction protein expression (ZO-1, occludin, and claudin-1) and maintained intestinal barrier and intestinal permeability integrity. In mice, BTL-1 significantly alleviated the intestinal inflammatory response induced by DSS, inhibited TLR4/NF-κB signaling pathway, and MAPK signaling pathway, thus reducing the production of IL-1, IL-6, and TNF-α. Further, the expression of tight junction proteins (ZO-1, occludin, and claudin-1) was upregulated in BTL-1 administrated mice. Therefore, it has been suggested that butyrolactone-I alleviates inflammatory responses in LPS-stimulated IPEC-J2 and DSS-induced murine colitis by TLR4/NF-κB and MAPK signal pathway. Thereby, BTL-1 might potentially be used as an ocean drug to prevent intestinal bowel disease.


2021 ◽  
Author(s):  
Emer Ryan ◽  
Lynne Kelly ◽  
Catherine Stacey ◽  
Dean Huggard ◽  
Eimear Duff ◽  
...  

Abstract Background: Paediatric traumatic brain injury (TBI) is recognised to have significant longer–term neurocognitive effects. Childhood is a time of high risk for head injury. Functional recovery is variable with a combination of any or all of physical, cognitive and emotional impairment. Immune activation and alteration in cytokine levels are present following TBI which may differ from adults. Methods: Pro and anti-inflammatory cytokines including Interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, IL-17A, Tumor Necrosis Factor (TNF)-α and Interferon (IFN)-γ were examined at baseline and following in vitro treatment with endotoxin of whole blood, in the following children: severe TBI (sTBI: initial Glasgow coma scale(GCS) £8), mild TBI (mTBI; GCS 14/15) at 0-4d and at 10-14d post-TBI and compared to healthy age-matched controls Results: The study enrolled 208 children including 110 with TBI cohort (n=104 mild; 6 severe) and controls (n=98). At baseline all children with TBI had increased IL-6. The mTBI group had significantly increased IFN-γ versus controls. In sTBI at baseline, IFN-γ was decreased compared to controls. At baseline IL-8, IL-10, IL-17A, and TNF-α were decreased in mTBI compared to controls. This persisted at two weeks post-mTBI. The AUC for detecting mTBI was 0.801 CI (0.73 – 086) using IL6/IL10 ratio. mTBI showed a greater fold change in IL-8 and TNF-α in response to endotoxin stimulation, a response that persisted at two weeks. Children with sTBI did not have a significant IL-6 response to endotoxin but did show an increase in IL-17A. Conclusion: Children with all TBI including mTBI show altered cytokine profiles and altered endotoxin responses. Although cytokines increased in sTBI especially in response to endotoxin, suppressed responses were found in mTBI coupled with persistent immune dysfunction post injury.


2021 ◽  
Vol 15 ◽  
Author(s):  
Han Liu ◽  
Junchi He ◽  
Yue Wu ◽  
Yang Du ◽  
Yinghua Jiang ◽  
...  

Background and TargetFollowing brain trauma, blood–brain barrier (BBB) disruption and inflammatory response are critical pathological steps contributing to secondary injury, leading to high mortality and morbidity. Both pathologies are closely associated with endothelial remodeling. In the present study, we concentrated on annexin A1 (ANXA1) as a novel regulator of endothelial function after traumatic brain injury.MethodsAfter establishing controlled cortical impact (CCI) model in male mice, human recombinant ANXA1 (rANXA1) was administered intravenously, followed by assessments of BBB integrity, brain edema, inflammatory response, and neurological deficits.ResultAnimals treated with rANXA1 (1 μg/kg) at 1 h after CCI exhibited optimal BBB protection including alleviated BBB disruption and brain edema, as well as endothelial junction proteins loss. The infiltrated neutrophils and inflammatory cytokines were suppressed by rANXA1, consistent with decreased adhesive and transmigrating molecules from isolated microvessels. Moreover, rANXA1 attenuated the neurological deficits induced by CCI. We further found that the Ras homolog gene family member A (RhoA) inhibition has similar effect as rANXA1 in ameliorating brain injuries after CCI, whereas rANXA1 suppressed CCI-induced RhoA activation.ConclusionOur findings suggest that the endothelial remodeling by exogenous rANXA1 corrects BBB disruption and inflammatory response through RhoA inhibition, hence improving functional outcomes in CCI mice.


2021 ◽  
Vol 11 (6) ◽  
pp. 1037-1045
Author(s):  
Bin Li ◽  
Honggang Yuan ◽  
Huibing Li ◽  
Baochang Luo ◽  
Xiaoping Yu ◽  
...  

Here, we aimed to clarify the anti-inflammatory function of Astragalus Polysaccharides (APS), a chemical compound derived from Astragalus membranaceus, and the action of AQP4 on brain injury. We hypothesized that APS could improve the traumatic brain injury (TBI) outcome via inhibiting expression of AQP4 in astrocytes. The present study elucidated that AQP4 was up-regulated and was effectively blocked by APS in mice with severe controlled cortical impact (CCI). Pre-treatment with APS effectively inhibited the up-regulation of AQP4 and diminished the neurological deficits in mice. Additionally, primary astrocytes treated with mechanically-injured astrocyte supernatant, to mimic TBI in vitro, showed a significant up-regulation in swelling. We confirmed various signal molecules (NF-ĸB, MAPKs, and ERK) to have a role in astrocyte swelling, after activation in trauma, and to be involved in the up-regulation of AQP4. These signal molecules also significantly decreased with APS treatment. In conclusion, our study suggests that APS attenuated neurological deficits and brain edema by decreasing AQP4 up-regulation in astrocytes following TBI in mice, via reducing NF-ĸB, MAPKs, and the ERK signal molecules.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ping Li ◽  
Tingting Shen ◽  
Xue Luo ◽  
Ju Yang ◽  
Zhen Luo ◽  
...  

AbstractNo FDA approved pharmacological therapy is available to reduce neuroinflammation following heatstroke. Previous studies have indicated that dexmedetomidine (DEX) could protect against inflammation and brain injury in various inflammation-associated diseases. However, no one has tested whether DEX has neuro-protective effects in heatstroke. In this study, we focused on microglial phenotypic modulation to investigate the mechanisms underlying the anti-inflammatory effects of DEX in vivo and in vitro. We found that DEX treatment reduced the expression of CD68, iNOS, TNF-α, and IL-1β, and increased the expression of CD206, Arg1, IL-10 and TGF-β in microglia, ameliorating heatstroke induced neuroinflammation and brain injury in mice. TREM2, whose neuro-protective function has been validated by genetic studies in Alzheimer’s disease and Nasu-Hakola disease, was significantly promoted by DEX in the microglia. TREM2 esiRNA reversed the DEX-induced activation of PI3K/Akt signalling. Overall these findings indicated that DEX may serve, as a potential therapeutic approach to ameliorate heatstroke induced neuroinflammation and brain injury via TREM2 by activating PI3K/Akt signalling.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tao Chen ◽  
Xiao Qian ◽  
Jie Zhu ◽  
Li-Kun Yang ◽  
Yu-Hai Wang

Decompressive craniectomy is an effective strategy to reduce intracranial hypertension after traumatic brain injury (TBI), but it is related to many postoperative complications, such as delayed intracranial hematoma and diffuse brain swelling. Our previous studies have demonstrated that controlled decompression (CDC) surgery attenuates brain injury and reduces the rate of complications after TBI. Here, we investigated the potential molecular mechanisms of CDC in experimental models. The in vitro experiments were performed in a traumatic neuronal injury (TNI) model following compression treatment in primary cultured cortical neurons. We found that compression aggravates TNI-induced neuronal injury, which was significantly attenuated by CDC for 2 h or 3 h. The results of immunocytochemistry showed that CDC reduced neuronal necroptosis and activation of RIP3 induced by TNI and compression, with no effect on RIP1 activity. These protective effects were associated with decreased levels of inflammatory cytokines and preserved intracellular Ca2+ homeostasis. In addition, the expression of the two-pore domain K+ channel TREK-1 and its activity was increased by compression and prolonged by CDC. Treatment with the TREK-1 blockers, spadin or SID1900, could partially prevent the effects of CDC on intracellular Ca2+ metabolism, necroptosis, and neuronal injury following TNI and compression. Using a traumatic intracranial hypertension model in rats, we found that CDC for 20 min or 30 min was effective in alleviating brain edema and locomotor impairment in vivo. CDC significantly inhibited neuronal necroptosis and neuroinflammation and increased TREK-1 activation, and the CDC-induced protection in vivo was attenuated by spadin and SID1900. In summary, CDC is effective in alleviating compressive neuronal injury both in vitro and in vivo, which is associated with the TREK-1-mediated attenuation of intracellular Ca2+ overload, neuronal necroptosis, and neuroinflammation.


2020 ◽  
Vol 12 (1) ◽  
pp. 001-008
Author(s):  
Ting Liu ◽  
Xing-Zhi Liao ◽  
Mai-Tao Zhou

Abstract Background Brain edema is one of the major causes of fatality and disability associated with injury and neurosurgical procedures. The goal of this study was to evaluate the effect of ulinastatin (UTI), a protease inhibitor, on astrocytes in a rat model of traumatic brain injury (TBI). Methodology A rat model of TBI was established. Animals were randomly divided into 2 groups – one group was treated with normal saline and the second group was treated with UTI (50,000 U/kg). The brain water content and permeability of the blood–brain barrier were assessed in the two groups along with a sham group (no TBI). Expression of the glial fibrillary acidic protein, endthelin-1 (ET-1), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) were measured by immunohistochemistry and western blot. Effect of UTI on ERK and PI3K/AKT signaling pathways was measured by western blot. Results UTI significantly decreased the brain water content and extravasation of the Evans blue dye. This attenuation was associated with decreased activation of the astrocytes and ET-1. UTI treatment decreased ERK and Akt activation and inhibited the expression of pro-inflammatory VEGF and MMP-9. Conclusion UTI can alleviate brain edema resulting from TBI by inhibiting astrocyte activation and ET-1 production.


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