scholarly journals Over-Activated Proteasome Mediates Neuroinflammation on Acute Intracerebral Hemorrhage in Rats

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1326 ◽  
Author(s):  
Hock-Kean Liew ◽  
Wei-Fen Hu ◽  
Peter Bor-Chian Lin ◽  
Po-Kai Wang ◽  
Andy Po-Yi Tsai ◽  
...  

Background: Neuroinflammation is a hallmark in intracerebral hemorrhage (ICH) that induces secondary brain injury, leading to neuronal cell death. ER stress-triggered apoptosis and proteostasis disruption caused neuroinflammation to play an important role in various neurological disorders. The consequences of ER stress and proteostasis disruption have rarely been studied during the course of ICH development. Methods: ICH was induced by collagenase VII-S intrastriatal infusion. Animals were sacrificed at 0, 3, 6, 24, and 72 h post-ICH. Rats were determined for body weight changes, hematoma volume, and neurological deficits. Brain tissues were harvested for molecular signaling analysis either for ELISA, immunoblotting, immunoprecipitation, RT-qPCR, protein aggregation, or for histological examination. A non-selective proteasome inhibitor, MG132, was administered into the right striatum three hours prior to ICH induction. Results: ICH-induced acute proteasome over-activation caused the early degradation of the endoplasmic reticulum (ER) chaperone GRP78 and IκB protein. These exacerbations were accompanied by the elevation of pro-apoptotic CCAAT-enhancer-binding protein homologous protein (CHOP) and pro-inflammatory cytokines expression via nuclear factor-kappa B (NF-κB) signal activation. Pre-treatment with proteasome inhibitor MG132 significantly ameliorated the ICH-induced ER stress/proteostasis disruption, pro-inflammatory cytokines, neuronal cells apoptosis, and neurological deficits. Conclusions: ICH induced rapid proteasome over-activation, leading to an exaggeration of the ER stress/proteostasis disruption, and neuroinflammation might be a critical event in acute ICH pathology.

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Liyan Zhang ◽  
Xiurong Zhao ◽  
Guanghua Sun ◽  
Jaroslaw Aronowski

Background: After intracerebral hemorrhage (ICH), the red blood cells (RBC) and their hemolytic products within brain hematoma trigger adverse biochemical events, leading to secondary brain injury and neurological deficits. Thus, efficient removal of hematoma components is essential for achieving inflammation resolution and functional recovery. The inducible heme-oxygenase (HO-1) is a key rate-limiting enzyme that catabolizes heme into iron, CO, and biliverdin. The present study investigated the role of HO-1 in microglia/macrophages (MΦ)-mediated phagocytosis of RBC; and also assessed the spatial and temporal expression of HO-1 in ICH-affected brain, as well as its possible role in the clearance of hematoma components following ICH modeled in rodents. Methods and Results: First, we employed the rat brain MΦ. Upon exposing to RBC, MΦ phagocytize RBC; and HO-1 was induced during this process. Co-incubating tin-protoporphyrin IX (SnPP, a competitive HO-1 inhibitor) with RBC significantly delayed RBC internalization by MΦ. Removal of SnPP from the culture medium led to a rapid recovery of MΦ’s phagocytic function, suggesting that SnPP-induced inhibition is a reversible process. Subjecting neuron-microglia co-cultures to RBC plus sublethal dose of oxygen-deprivation (an ICH-like insult) triggered neuronal injury, as assessed using neurofilament degradation assay and loss of NeuN-positive cells; and addition of SnPP further aggravated the neuronal injury. Additional studies showed that after ICH, HO-1 is up-regulated in hematoma-affected rat brain tissues starting from 6h, reaching the maximum level at 3-7days, and persisting for at least 10 days after ICH. Double immunohistochemistry of HO-1 and brain cell markers shows that the most HO-1-positive cells are Iba1-positive MΦ. Administration of SnPP for 7 days, (7.5 mg/kg, ip, twice a day) delayed hematoma clearance by 27.8% and significantly impaired the functional recovery, as measured 7 days after ICH. Histological analyses showed that there are more TUNEL-positive neurons in the hematoma-affected brain tissue in SnPP-treated mouse brains. Conclusion: Our study suggests that HO-1 is essential for phagocytosis of RBC by MΦ, which is critical for endogenous clearance of hematoma after ICH.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Min Cai ◽  
Zhonghai Yu ◽  
Wen Zhang ◽  
Li Yang ◽  
Jun Xiang ◽  
...  

Objects. Sheng-Di-Da-Huang Decoction was used as an effective hemostatic agent in ancient China. However, its therapeutic mechanism is still not clear. Inflammatory injury plays a critical role in ICH-induced secondary brain injury. After hemolysis, hematoma components are released, inducing microglial activation via TLR4, which initiates the activation of transcription factors (such as NF-κB) to regulate expression of proinflammatory cytokine genes. This study aimed to verify the anti-inflammatory effects of Sheng-Di-Da-Huang Decoction on ICH rats. Materials and Methods. Intracerebral hemorrhage was induced by injection of bacterial collagenase (0.2 U) in rats. Neurological deficits, brain water content, Evans blue extravasation, expression of TLR4, NF-κB, Iba-1 positive cells (activated microglia), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were examined 1, 3, 7, and 14 days after collagenase injection. MR images were also studied. Results. Sheng-Di-Da-Huang Decoction remarkably improved neurological function, reduced brain water content as well as Evans blue extravasation, downregulated expression of TLR4, NF-κB, TNF-α, and IL-1β, and inhibited microglial activation. Conclusions. Sheng-Di-Da-Huang Decoction reduced inflammation reaction after ICH through inhibited inflammation expressed in microglia.


2018 ◽  
Vol 96 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Qichao Wu ◽  
Yanjun Zhao ◽  
Xiangyuan Chen ◽  
Minmin Zhu ◽  
Changhong Miao

Activated microglia, involved in the occurrence and improvement of sepsis-associated encephalopathy, can induce the expression of pro-inflammatory cytokines and pro-inflammatory enzymes, resulting in inflammation-mediated neuronal cell death. It was reported that propofol could inhibit lipopolysaccharide (LPS) induced pro-inflammatory cytokine and pro-inflammatory enzyme expression in BV2 and primary microglial cells. However, the underlying mechanism is not well known. In the present study, we investigated whether and how propofol inhibited LPS-induced the expression of pro-inflammatory cytokines and pro-inflammatory enzymes in BV2 cells. LPS induced pro-inflammatory cytokine and pro-inflammatory enzyme expression, NF-κB, extracellular regulated kinase 1/2 (ERK), calcium (Ca2+)/calmodulin-dependent protein kinase II (CaMK II) phosphorylation, and BV2 cell Ca2+ accumulation. Propofol could reverse these effects induced by LPS. MK801, an inhibitor of the NMDA receptor, could attenuate LPS-induced Ca2+ accumulation, the expression of pro-inflammatory cytokines and pro-inflammatory enzymes, and phosphorylation of NF-κB, ERK, and CaMK II, which was similar to propofol. Moreover, these effects of propofol could be counteracted by rapastinel, an activator of the NMDA receptor. The present study suggested that propofol, via inhibiting the NMDA receptor, attenuating Ca2+ accumulation, and inhibiting CaMK II, ERK1/2, and NF-κB phosphorylation, down-regulated LPS-induced pro-inflammatory cytokine and pro-inflammatory enzyme expression.


2021 ◽  
Author(s):  
Shuwen Deng ◽  
Qing Hu ◽  
Qiang He ◽  
Xiqian Chen ◽  
Wei Lu

Abstract Blood–brain barrier (BBB) impairment after intracerebral hemorrhage (ICH) can lead to secondary brain injury and aggravate neurological deficits. Currently, there are no effective methods for its prevention or treatment partly because of to our lack of understanding of the mechanism of ICH injury to the BBB. Here, we explored the role of Golgi apparatus protein GM130 in the BBB and neurological function after ICH. The levels of the tight junction-associated proteins ZO-1 and occludin decreased, whereas those of LC3-II, an autophagosome marker, increased in hemin-treated Bend.3 cells (p < 0.05). Additionally, GM130 overexpression increased ZO-1 and occludin levels, while decreasing LC3-II levels (p < 0.05). GM130 silencing reversed these effects and mimicked the effect of hemin treatment (p < 0.05). Moreover, tight junctions were disrupted after hemin treatment or GM130 silencing and repaired by GM130 overexpression. GM130 silencing in Bend.3 cells increased autophagic flux, whereas GM130 overexpression downregulated this activity. Furthermore, GM130 silencing-induced tight junction disruption was partially restored by 3-methyladenine (an autophagy inhibitor) administration. Similarly, an in vivo ICH rat model showed elevated perihematomal ZO-1 and occludin expression and decreased LC3-II expression (p < 0.05); these results were reversed following GM130 silencing (p < 0.05). Perihematomal Evans Blue staining and brain water content were elevated in GM130-silenced ICH rats relative to control ICH rats. GM130 overexpression can protect BBB integrity from brain injury, inhibit excessive autophagy flux in ICH, and improve neurobehavioral prognosis. Therefore, therapy targeting GM130 regulation might represent a potential treatment for acute brain injury after ICH.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Na Li ◽  
Yan Fang Liu ◽  
Li Ma ◽  
Hans Worthmann ◽  
Peter Raab ◽  
...  

Background and Purpose: Perihematomal edema (PHE) contributes to secondary brain injury in intracerebral hemorrhage (ICH). Increase of matrix metalloproteinases (MMPs) and growth factors (GFs) is considerably involved in blood-brain barrier disruption and neuronal cell death in ICH models. We therefore hypothesized that increased levels of these molecular markers are associated with PHE and clinical outcome in ICH patients. Methods: Fifty-nine patients with spontaneous ICH admitted within 24 hours of symptom onset were prospectively investigated. Noncontrast CT was performed on admission for diagnosis of ICH and quantification of initial hematoma volume. MRI was performed on day 3 in order to evaluate PHE. Concentrations of MMP-3, MMP-9, as well as vascular endothelial growth factor (VEGF) and Angiopoietin-1(Ang-1) on admission were determined by enzyme-linked immunosorbent assays. Clinical outcome was assessed by modified Rankin Scale (mRS) at 90days. Results: Increased MMP-3 levels were independently associated with PHE volume (P<0.05). Cytotoxic edema (CE) surrounding the hematoma was seen in 36 (61%) cases on 3-day MRI. CE did not correlate with the level of any of the biomarkers studied. Levels of MMP-3 ≥12.4 ng/ml and MMP-9 ≥192.4 ng/ml but not VEGF and Ang-1 predicted poor clinical outcome at 90 days (mRS>3) independent of stroke severity and hematoma volume at baseline (OR 25.3, P=0.035; OR 68.9, P=0.023; respectively). Conclusion: Metalloproteinases 3 and 9 seem to be significantly involved in secondary brain injury and outcome after primary ICH in humans and thus should be further evaluated as targets for therapeutic strategies in this devastating disorder.


2020 ◽  
Author(s):  
Alan C-Y. Hsu ◽  
Guoqiang Wang ◽  
Andrew T. Reid ◽  
Punnam Chander Veerati ◽  
Prabuddha S. Pathinayake ◽  
...  

SummarySARS-CoV-2 infection causes an inflammatory cytokine storm and acute lung injury. Currently there are no effective antiviral and/or anti-inflammatory therapies. Here we demonstrate that 2019 SARS-CoV-2 spike protein subunit 1 (CoV2-S1) induces high levels of NF-κB activations, production of pro-inflammatory cytokines and mild epithelial damage, in human bronchial epithelial cells. CoV2-S1-induced NF-κB activation requires S1 interaction with human ACE2 receptor and early activation of endoplasmic reticulum (ER) stress, and associated unfolded protein response (UPR), and MAP kinase signalling pathways. We developed an antagonistic peptide that inhibits S1-ACE2 interaction and CoV2-S1-induced productions of pro-inflammatory cytokines. The existing FDA-approved ER stress inhibitor, 4-phenylburic acid (4-PBA), and MAP kinase inhibitors, trametinib and ulixertinib, ameliorated CoV2-S1-induced inflammation and epithelial damage. These novel data highlight the potentials of peptide-based antivirals for novel ACE2-utilising CoVs, while repurposing existing drugs may be used as treatments to dampen elevated inflammation and lung injury mediated by SARS-CoV-2.


2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Xu Wang ◽  
Guang-Jian Li ◽  
Hai-Xia Hu ◽  
Chi Ma ◽  
Di-Hui Ma ◽  
...  

AbstractAs a part of Alzheimer’s disease (AD) development the mammalian target of rapamycin (mTOR) has been reported to play a crucial role in regulating cognition and can be used as a neuronal marker. Neuro-inflammation is also a cause of the pathophysiological process in AD. Thus, we examined the protein expression levels of mTOR and its downstream pathways as well as pro-inflammatory cytokines (PICs) in the brain of AD rats. We further examined the effects of blocking mTOR on PICs, namely IL-1β, IL-6 and TNF-α. Our results showed that the protein expression of p-mTOR, mTOR-mediated phosphorylation of 4E-binding protein 4 (4E-BP1) and p70 ribosomal S6 protein kinase 1 (S6K1) pathways were amplified in the hippocampus of AD rats compared with controls. Blocking mTOR by using rapamycin selectively enhanced activities of IL-6 and TNF-α signaling pathways, which was accompanied with an increase of Caspase-3, indicating cellular apoptosis and worsened learning performance. In conclusion, our data for the first time revealed specific signaling pathways engaged in the development of AD, including a regulatory role by the activation of mTOR in PIC mechanisms. Stimulation of mTOR is likely to play a beneficial role in modulating neurological deficits in AD.Targeting one or more of these signaling molecules may present with new opportunities for treatment and clinical management of AD


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Xuan Wu ◽  
Siming Fu ◽  
Yun Liu ◽  
Hansheng Luo ◽  
Feng Li ◽  
...  

Abstract Background Neuroinflammation and blood-brain barrier (BBB) disruption are two vital mechanisms of secondary brain injury following intracerebral hemorrhage (ICH). Recently, melanocortin-1 receptor (Mc1r) activation by Nle4-D-Phe7-α-MSH (NDP-MSH) was shown to play a neuroprotective role in an experimental autoimmune encephalomyelitis (EAE) mouse model. This study aimed to investigate whether NDP-MSH could alleviate neuroinflammation and BBB disruption after experimental ICH, as well as the potential mechanisms of its neuroprotective roles. Methods Two hundred and eighteen male C57BL/6 mice were subjected to autologous blood-injection ICH model. NDP-MSH, an agonist of Mc1r, was administered intraperitoneally injected at 1 h after ICH insult. To further explore the related protective mechanisms, Mc1r small interfering RNA (Mc1r siRNA) and nuclear receptor subfamily 4 group A member 1 (Nr4a1) siRNA were administered via intracerebroventricular (i.c.v) injection before ICH induction. Neurological test, BBB permeability, brain water content, immunofluorescence staining, and Western blot analysis were implemented. Results The Expression of Mc1r was significantly increased after ICH. Mc1r was mainly expressed in microglia, astrocytes, and endothelial cells following ICH. Treatment with NDP-MSH remarkably improved neurological function and reduced BBB disruption, brain water content, and the number of microglia in the peri-hematoma tissue after ICH. Meanwhile, the administration of NDP-MSH significantly reduced the expression of p-NF-κB p65, IL-1β, TNF-α, and MMP-9 and increased the expression of p-CREB, Nr4a1, ZO-1, occludin, and Lama5. Inversely, the knockdown of Mc1r or Nr4a1 abolished the neuroprotective effects of NDP-MSH. Conclusions Taken together, NDP-MSH binding Mc1r attenuated neuroinflammation and BBB disruption and improved neurological deficits, at least in part through CREB/Nr4a1/NF-κB pathway after ICH.


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