Pertussis toxin–induced inflammatory response exacerbates intracerebral haemorrhage and ischaemic stroke in mice

BackgroundStroke is a devastating disease, including intracerebral haemorrhage (ICH) and ischaemic stroke. Emerging evidences indicate that systemic inflammatory cascades after stroke contribute to brain damage. However, the direct effects and features of systemic inflammation on brain injury, especially comparing between ischaemic and haemorrhagic stroke, are still obscure.MethodsPertussis toxin (PT) was used to build a pro-inflammatory milieu after ICH and ischaemic stroke in mouse model. The neurodeficits, stroke lesion, immune response and blood–brain barrier (BBB) destruction were assessed.ResultsIn ICH mouse model, PT-induced systemic inflammation exacerbated neurological deficits, and enlarged haemorrhage lesion and perihaematomal oedema. We also found promoted leucocyte infiltration and inflammatory cytokine release into the brain after PT treatment. Moreover, the integrity of the BBB was further disrupted after receiving PT. Furthermore, we demonstrated that PT enhanced brain inflammation and aggravated stroke severity in middle cerebral artery occlusion mouse model.ConclusionsOur results suggest that PT increases inflammatory response that exacerbates brain injury after ICH or ischaemic stroke in mouse model.

Download Full-text

Pertussis Toxin Induced Inflammatory Response Exacerbates Intracerebral Hemorrhage and Ischemic Stroke in Mice

10.21203/rs.3.rs-126762/v1 ◽

2020 ◽

Author(s):

Ming Zou ◽

Yan Li ◽

Hui Zhao ◽

Yan Feng ◽

Ying Zhang ◽

...

Keyword(s):

Ischemic Stroke ◽

Inflammatory Response ◽

Mouse Model ◽

Intracerebral Hemorrhage ◽

Blood Brain Barrier ◽

Pertussis Toxin ◽

Brain Inflammation ◽

Brain Barrier ◽

Stroke Severity ◽

Blood Brain

Abstract Background: Stroke is a devastating and debilitating disease and is a leading cause of death worldwide, including intracerebral hemorrhage (ICH) and ischemic stroke. Emerging evidence indicates that inflammatory cascades after hemorrhagic or ischemic stroke makes a great contribution to brain damage, mainly are involved in neuronal cell death, blood-brain-barrier (BBB) destruction and development of vasogenic edema. However, the features and direct effect of brain inflammation following stroke is still unknown. Methods: We adopted the ICH model by injection of collagenase and used a mouse model of transient cerebral ischemia and reperfusion. And pertussis toxin was used to create a pro-inflammatory milieu. Neurodeficits, lesion volume, production of reactive oxygen species (ROS) and inflammatory factors, brain-infiltrating leukocytes and blood-brain-barrier (BBB) destruction were assessed in mice model treated with pertussis toxin or vehicle.Results: Adopting collagenase induced intracerebral hemorrhage mouse model, we show that pertussis toxin-induced systemic inflammation exacerbated neurological deficits, enlarged lesion size and brain perihematomal edema after intracerebral hemorrhage. Pertussis toxin promoted leukocyte infiltration and inflammatory cytokine release in the brain. Moreover, the integrity of the BBB was further disrupted after receiving pertussis toxin in ICH mice. Furthermore, we demonstrated that pertussis toxin increased stroke severity and enhanced brain inflammation in middle cerebral artery occlusion (MCAO) mouse model. Conclusion: Our results suggest that pertussis toxin increases inflammatory response that exacerbates brain injury after intracerebral hemorrhage or ischemic stroke in mouse model.

Download Full-text

Annexin A2 Deficiency Exacerbates Neuroinflammation and Long-Term Neurological Deficits after Traumatic Brain Injury in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms20246125 ◽

2019 ◽

Vol 20 (24) ◽

pp. 6125 ◽

Cited By ~ 5

Author(s):

Ning Liu ◽

Yinghua Jiang ◽

Joon Yong Chung ◽

Yadan Li ◽

Zhanyang Yu ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Inflammatory Response ◽

Neurovascular Unit ◽

Annexin A2 ◽

Tissue Loss ◽

Neurological Deficits ◽

Endogenous Factors ◽

The Brain

Our laboratory and others previously showed that Annexin A2 knockout (A2KO) mice had impaired blood–brain barrier (BBB) development and elevated pro-inflammatory response in macrophages, implying that Annexin A2 (AnxA2) might be one of the key endogenous factors for maintaining homeostasis of the neurovascular unit in the brain. Traumatic brain injury (TBI) is an important cause of disability and mortality worldwide, and neurovascular inflammation plays an important role in the TBI pathophysiology. In the present study, we aimed to test the hypothesis that A2KO promotes pro-inflammatory response in the brain and worsens neurobehavioral outcomes after TBI. TBI was conducted by a controlled cortical impact (CCI) device in mice. Our experimental results showed AnxA2 expression was significantly up-regulated in response to TBI at day three post-TBI. We also found more production of pro-inflammatory cytokines in the A2KO mouse brain, while there was a significant increase of inflammatory adhesion molecules mRNA expression in isolated cerebral micro-vessels of A2KO mice compared with wild-type (WT) mice. Consistently, the A2KO mice brains had a significant increase in leukocyte brain infiltration at two days after TBI. Importantly, A2KO mice had significantly worse sensorimotor and cognitive function deficits up to 28 days after TBI and significantly larger brain tissue loss. Therefore, these results suggested that AnxA2 deficiency results in exacerbated early neurovascular pro-inflammation, which leads to a worse long-term neurologic outcome after TBI.

Download Full-text

17β-Estradiol Attenuates Intracerebral Hemorrhage-Induced Blood–Brain Barrier Injury and Oxidative Stress Through SRC3-Mediated PI3K/Akt Signaling Pathway in a Mouse Model

ASN NEURO ◽

10.1177/17590914211038443 ◽

2021 ◽

Vol 13 ◽

pp. 175909142110384

Author(s):

Han Xiao ◽

Jianyang Liu ◽

Jialin He ◽

Ziwei Lan ◽

Mingyang Deng ◽

...

Keyword(s):

Oxidative Stress ◽

Brain Injury ◽

Mouse Model ◽

Intracerebral Hemorrhage ◽

Signaling Pathway ◽

Brain Edema ◽

Akt Signaling ◽

Neurological Deficits ◽

Akt Signaling Pathway ◽

And Oxidative Stress

Estrogen is neuroprotective in brain injury models, and steroid receptor cofactor 3 (SRC3) mediates estrogen signaling. We aimed to investigate whether and how SRC3 is involved in the neuroprotective effects of 17ß-estradiol (E2) in a mouse model of intracerebral hemorrhage (ICH). Ovariectomized female mice were treated with E2 after autologous blood injection-induced ICH. Brain damage was assessed by neurological deficit score, brain water content, and oxidative stress levels. Blood–brain barrier (BBB) integrity was evaluated by Evan's blue extravasation and claudin-5, ZO-1, and occludin levels. SRC3 expression and PI3K/Akt signaling pathway were examined in ICH mice treated with E2. The effect of SRC3 on E2-mediated neuroprotection was determined by examining neurological outcomes in SRC3-deficient mice undergone ICH and E2 treatment. We found that E2 alleviated ICH-induced brain edema and neurological deficits, protected BBB integrity, and suppressed oxidative stress. E2 enhanced SRC3 expression and PI3K-/Akt signaling pathway. SRC3 deficiency abolished the protective effects of E2 on ICH-induced neurological deficits, brain edema, and BBB integrity. Our results suggest that E2 suppresses ICH-induced brain injury and SRC3 plays a critical role in E2-mediated neuroprotection.

Download Full-text

Astrocyte-derived exosomes enriched with miR-873a-5p inhibit neuroinflammation via microglia phenotype modulation after traumatic brain injury

10.21203/rs.2.17543/v2 ◽

2020 ◽

Author(s):

xiaobing long ◽

Xiaolong Yao ◽

Qian Jiang ◽

Yiping Yang ◽

Xuejun He ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mouse Model ◽

Vital Role ◽

Neurological Deficits ◽

Inflammatory Factors ◽

Protective Mechanism ◽

Vitro Model ◽

Phenotype Transformation

Abstract Background: The interaction between astrocytes and microglia plays a vital role in the damage and repair of brain lesions due to traumatic brain injury (TBI). Recent studies have shown that exosomes act as potent mediators involved in intercellular communication. Methods: In the current study, the expression of inflammatory factors and miR-873a-5p in the lesion area and edema area was evaluated in 15 patients with traumatic brain injury. Exosomes secreted by astrocytes were detected by immunofluorescence, Western blot, and electron microscopy. A mouse model of TBI and an in vitro model of lps-induced primary microglia were established to study the protective mechanism of exosomes from miR-873a-5p-overexpressing in TBI-induced nerve injury.Results: We discovered that exosomes derived from activated astrocytes promote microglial M2 phenotype transformation following TBI. More than 100 miRNAs were detected in these astrocyte-derived exosomes. miR-873a-5p is a major component that was highly expressed in human traumatic brain tissue. Moreover, miR-873a-5p significantly inhibited LPS-induced microglial M1 phenotype transformation and the subsequent inflammation through decreased phosphorylation of ERK and NF-κB p65. This effect also greatly improved the mNSS score and attenuated brain injury in a strictly controlled cortical impact mouse model. Conclusions: Taken together, our research indicates that miRNAs in the exosomes derived from activated astrocytes play a key role in the astrocyte-microglia interaction. miR-873a-5p, as one of the main components of these astrocyte-derived exosomes, attenuated microglia-mediated neuroinflammation and improved neurological deficits following TBI by inhibiting the NF-kB signalling pathway. These findings suggest a potential role for miR-873a-5p in treating traumatic brain injury.

Download Full-text

Isoquercetin Improves Inflammatory Response in Rats Following Ischemic Stroke

Frontiers in Neuroscience ◽

10.3389/fnins.2021.555543 ◽

2021 ◽

Vol 15 ◽

Author(s):

Yunwei Shi ◽

Xinyi Chen ◽

Jiaxing Liu ◽

Xingjuan Fan ◽

Ying Jin ◽

...

Keyword(s):

Ischemic Stroke ◽

Brain Injury ◽

Inflammatory Response ◽

Signaling Pathway ◽

Neurological Deficits ◽

Cell Recovery ◽

C5a Receptor ◽

Neuroprotective Agent

Inflammatory response contributes to brain injury after ischemia and reperfusion (I/R). Our previous literature has shown isoquercetin plays an important role in protecting against cerebral I/R injury. The present study was conducted to further investigate the effect of isoquercetin on inflammation-induced neuronal injury in I/R rats with the involvement of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and inhibitor of NF-κB (I-κB)/nuclear factor-kappa B (NF-κB) signaling pathway mediated by Toll-like receptor 4 (TLR4) and C5a receptor 1 (C5aR1). In vivo middle cerebral artery occlusion and reperfusion (MCAO/R) rat model and in vitro oxygen-glucose deprivation and reperfusion (OGD/R) neuron model were used. MCAO/R induced neurological deficits, cell apoptosis, and release of cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in ischemic brain in rats. Simultaneously, the expression of TLR4 and C5aR1 was significantly up-regulated in both MCAO/R rats and OGD/R neurons, accompanied with the inhibition of cAMP/PKA signaling and activation of I-κB/NF-κB signaling in the cortex of MCAO/R rats. Over-expression of C5aR1 in neurons induced decrease of cell viability, exerting similar effects with OGD/R injury. Isoquercetin acted as a neuroprotective agent against I/R brain injury to suppress inflammatory response and improve cell recovery by inhibiting TLR4 and C5aR1 expression, promoting cAMP/PKA activation, and inhibiting I-κB/NF-κB activation and Caspase 3 expression. TLR4 and C5aR1 contributed to inflammation and apoptosis via activating cAMP/PKA/I-κB/NF-κB signaling during cerebral I/R, suggesting that this signaling pathway may be a potent therapeutic target in ischemic stroke. Isoquercetin was identified as a neuroprotective agent, which maybe a promising therapeutic agent used for the treatment of ischemic stroke and related diseases.

Download Full-text

Systemic inflammation in hemorrhagic strokes – A novel neurological sign and therapeutic target?

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x19841443 ◽

2019 ◽

Vol 39 (6) ◽

pp. 959-988 ◽

Cited By ~ 9

Author(s):

Aisha R Saand ◽

Fang Yu ◽

Jun Chen ◽

Sherry H-Y Chou

Keyword(s):

Brain Injury ◽

Inflammatory Response ◽

Immune Responses ◽

Systemic Inflammation ◽

Systemic Disease ◽

Systemic Inflammatory Response ◽

Organ Systems ◽

Novel Therapeutic Strategies ◽

The Impact ◽

The Brain

Growing evidences suggest that stroke is a systemic disease affecting many organ systems beyond the brain. Stroke-related systemic inflammatory response and immune dysregulations may play an important role in brain injury, recovery, and stroke outcome. The two main phenomena in stroke-related peripheral immune dysregulations are systemic inflammation and post-stroke immunosuppression. There is emerging evidence suggesting that the spleen contracts following ischemic stroke, activates peripheral immune response and this may further potentiate brain injury. Whether similar brain–immune crosstalk occurs in hemorrhagic strokes such as intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) is not established. In this review, we systematically examined animal and human evidence to date on peripheral immune responses associated with hemorrhagic strokes. Specifically, we reviewed the impact of clinical systemic inflammatory response syndrome (SIRS), inflammation- and immune-associated biomarkers, the brain–spleen interaction, and cellular mediators of peripheral immune responses to ICH and SAH including regulatory T cells (Tregs). While there is growing data suggesting that peripheral immune dysregulation following hemorrhagic strokes may be important in brain injury pathogenesis and outcome, details of this brain-immune system cross-talk remain insufficiently understood. This is an important unmet scientific need that may lead to novel therapeutic strategies in this highly morbid condition.

Download Full-text

Systemic Inflammation Alters the Neuroinflammatory Response: A Prospective Clinical Trial in Traumatic Brain Injury.

10.21203/rs.3.rs-345717/v1 ◽

2021 ◽

Author(s):

Philipp Lassarén ◽

Caroline Lindblad ◽

Arvid Frostell ◽

Keri LH Carpenter ◽

Mathew R Guilfoyle ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Inflammatory Response ◽

Information Content ◽

Systemic Inflammation ◽

Clinical Infection ◽

Mixed Effect ◽

Markers Of Inflammation ◽

Arterial Blood ◽

Cytokine Levels

Abstract Background: Neuroinflammation following traumatic brain injury (TBI) has been shown to be associated with secondary injury development, however how systemic inflammatory mediators affect this is not fully understood. The aim of this study was to see how systemic inflammation affects markers of neuroinflammation, if this inflammatory response had a temporal correlation between compartments and how different compartments differ in cytokine composition.Methods: TBI patients recruited to a previous randomized controlled trial studying the effects of the drug anakinra (Kineret®), a human recombinant interleukin-1 receptor antagonist (rhIL1ra), were used (n=10 treatment arm, n=10 control arm). Cytokine concentrations were measured in arterial and venous samples twice a day, as well as in microdialysis-extracted brain extracellular fluid (ECF) following pooling every 6 hours. C-reactive protein level (CRP), white blood cell count (WBC), temperature and confirmed systemic clinical infection were used as systemic markers of inflammation. Principal component analyses, linear mixed-effect models, cross-correlations and multiple factor analyses were used.Results: The development of a systemic clinical infection results in an altered brain-ECF cytokine response (e.g. increase in G-CSF and decrease in PDGF-ABBB, p<0.05 respectively), even if adjusting for injury severity and demographic factors. rhIL1ra administration had a strong effect on the inflammatory response, independently altering different blood (n=6) and brain cytokine (n=3) levels. No substantial delayed temporal association between blood and brain compartments could be detected. Jugular and arterial blood held similar cytokine information content, but brain-ECF was markedly different. No clear arterial to jugular gradient could be seen.Conclusions: Systemic inflammation, and infection in particular, alters cerebral cytokine levels, and rhIL1ra administration potently affects both systemic and cerebral cytokine levels. Cerebral inflammatory monitoring provides independent information from arterial and jugular samples, which both demonstrate similar information content. These findings could present potential new treatment options in severe TBI patients, and stresses the need of adequate monitoring of inflammatory markers.

Download Full-text

Glia Maturation Factor (GMF) Regulates Microglial Expression Phenotypes and the Associated Neurological Deficits in a Mouse Model of Traumatic Brain Injury

Molecular Neurobiology ◽

10.1007/s12035-020-02040-y ◽

2020 ◽

Vol 57 (11) ◽

pp. 4438-4450 ◽

Cited By ~ 1

Author(s):

Mohammad Ejaz Ahmed ◽

Govindhasamy Pushpavathi Selvakumar ◽

Duraisamy Kempuraj ◽

Sudhanshu P. Raikwar ◽

Ramasamy Thangavel ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mouse Model ◽

Neurological Deficits ◽

Glia Maturation Factor ◽

Maturation Factor

Download Full-text

Pretreatment with Shuanghe-Tang Extract Attenuates Postischemic Brain Injury and Edema in a Mouse Model of Stroke: An Analysis of Medicinal Herbs Listed in Dongui Bogam

Oxidative Medicine and Cellular Longevity ◽

10.1155/2018/2479602 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

Min Jae Kim ◽

Seo-Yeon Lee ◽

Ji Young Hwang ◽

Hyunha Kim ◽

Ki-Tae Ha ◽

...

Keyword(s):

Brain Injury ◽

Cerebral Ischemia ◽

Mouse Model ◽

Focal Cerebral Ischemia ◽

Infarct Volume ◽

Immunohistochemical Analysis ◽

Medicinal Herbs ◽

Neurological Deficits ◽

Dependent Manner

Aim. Although stroke is among the leading causes of death and long-term disability, there are few effective treatments for limiting the severity of neurological sequelae. We evaluated the effects of 29 medicinal herbs listed in the Pung chapter of the 17th century Korean medical text Dongui Bogam on stroke symptoms in a mouse model of cerebral ischemia. Methods. Focal cerebral ischemia was induced via photothrombosis. Infarct volume, brain edema, and neurological deficits were evaluated. Immunofluorescence staining for tight junction proteins and aquaporin 4 (AQP4) was performed following ischemic injury. Results. Based on our initial findings, we examined the effects of two prescriptions in which the candidate herbs comprised more than 60% of the total formula: Shuanghe-tang and Zengsunsiwu-tang. Pretreatment with Shuanghe-tang significantly reduced infarct volume, decreased blood-brain barrier (BBB) breakdown, attenuated edema, and improved neurological and motor functions in a dose-dependent manner (30, 100, and 300 mg/kg), while no such effects were observed in mice pretreated with Zengsunsiwu-tang. Immunohistochemical analysis revealed significant increases in ipsilateral occludin and zonula occludens 1 (ZO-1) expression in Shuanghe-tang-pretreated mice, as well as increased AQP4 immunofluorescence. Conclusions. These results indicate that Shuanghe-tang may protect against brain injury and promote recovery of neurological function following ischemia.

Download Full-text

Astrocyte-derived exosomes enriched with miR-873a-5p inhibit neuroinflammation via microglia phenotype modulation after traumatic brain injury

10.21203/rs.2.17543/v1 ◽

2019 ◽

Author(s):

xiaobing long ◽

Xiaolong Yao ◽

Qian Jiang ◽

Yiping Yang ◽

Xuejun He ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mouse Model ◽

Vital Role ◽

Neurological Deficits ◽

Inflammatory Factors ◽

Protective Mechanism ◽

Vitro Model ◽

Phenotype Transformation

Abstract Background: The interaction between astrocytes and microglia plays a vital role in the damage and repair of brain lesions due to traumatic brain injury (TBI). Recent studies have shown that exosomes act as potent mediators involved in intercellular communication. Methods: In the current study, the expression of inflammatory factors and miR-873a-5p in the lesion area and edema area was evaluated in 15 patients with traumatic brain injury. Exosomes secreted by astrocytes were detected by immunofluorescence, Western blot, and electron microscopy. A mouse model of TBI and an in vitro model of lps-induced primary microglia were established to study the protective mechanism of exosomes from miR-873a-5p-overexpressing in TBI-induced nerve injury. Results: We discovered that exosomes derived from activated astrocytes promote microglial M2 phenotype transformation following TBI. More than 100 miRNAs were detected in these astrocyte-derived exosomes. miR-873a-5p is a major component that was highly expressed in human traumatic brain tissue. Moreover, miR-873a-5p significantly inhibited LPS-induced microglial M1 phenotype transformation and the subsequent inflammation through decreased phosphorylation of ERK and NF-κB p65. This effect also greatly improved the mNSS score and attenuated brain injury in a strictly controlled cortical impact mouse model. Conclusions: Taken together, our research indicates that miRNAs in the exosomes derived from activated astrocytes play a key role in the astrocyte-microglia interaction. miR-873a-5p, as one of the main components of these astrocyte-derived exosomes, attenuated microglia-mediated neuroinflammation and improved neurological deficits following TBI by inhibiting the NF-kB signalling pathway. These findings suggest a potential role for miR-873a-5p in treating traumatic brain injury.

Download Full-text