scholarly journals CXCL-12 Attenuates Neuroinflammation via the CXCR4/PI3K/Akt Signaling Pathway in a Rat Model of SAH

Author(s):  
Gang Zuo ◽  
Ran Gu ◽  
Lu Wang ◽  
Cameron Lenahan ◽  
Hao Qu ◽  
...  

Abstract BackgroundSubarachnoid hemorrhage (SAH) is a cerebrovascular disease associated with high morbidity and mortality. CXCR4 provides a neuroprotective effect, which can alleviate brain injury and inflammation induced by stroke. The purpose of this study was to evaluate the anti-inflammatory effects and mechanisms of CXCR4 after SAH. Methods: SAH was induced via endovascular perforation. 185 male Sprague-Dawley rats were used. Recombinant human cysteine-X-cysteine chemokine ligand 12 (rh-CXCL-12) was administered intranasally at 1 h after SAH induction. To investigate the underlying mechanism, the inhibitors of CXCR4 and P13K, AMD3100 and LY294002, respectively, were administered intraperitoneally at 1 h before SAH. The short- and long-term neurobehavior were assessed, followed by performing western blot and immunofluorescence staining. ResultsWestern blotting suggested that the expressions of endogenous CXCL-12 and CXCR4 were increased, and peaked at 24 h following SAH. Immunofluorescence staining showed that CXCR4 was expressed on microglia. Rh-CXCL-12 treatment reduced the number of M1 macrophages and improved the short- and long-term neurological deficits after SAH. Meanwhile, rh-CXCL-12 treatment increased the levels of CXCL-12, CXCR4, PI3K, and p-Akt, and reduced the levels of IL-1β, IL-6, and TNF-α. Moreover, the administration of AMD3100 and LY294002 abolished the post-SAH neurobehavioral and neuroinflammatory improvements of CXCL-12 and its regulation of PI3K and p-Akt protein levels.ConclusionsThe CXCR4/PI3K/Akt signaling pathway may be involved in CXCL-12-mediated reduction of post-SAH neuroinflammation. Early administration of CXCL-12 may be a preventive and therapeutic strategy against delayed brain injury after SAH.

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ran Gu ◽  
Lu Wang ◽  
Hao Zhou ◽  
Xike Wang ◽  
Cameron Lenahan ◽  
...  

Subarachnoid hemorrhage (SAH) is a cerebrovascular disease associated with high morbidity and mortality. CXCR4 provides neuroprotective effects, which can alleviate brain injury and inflammation induced by stroke. Previous studies have suggested that CXCR4 reduces the pyroptosis of LPS-stimulated BV2 cells. The purpose of this study was to evaluate the antipyroptosis effects and mechanisms of CXCR4 after SAH. SAH animal model was induced via endovascular perforation. A total of 136 male Sprague-Dawley rats were used. Recombinant human cysteine-X-cysteine chemokine ligand 12 (rh-CXCL-12) was administered intranasally at 1 h after SAH induction. To investigate the underlying mechanism, the inhibitor of CXCR4, AMD3100, was administered intraperitoneally at 1 h before SAH. The neurobehavior tests were assessed, followed by performing Western blot and immunofluorescence staining. The Western blot results suggested that the expressions of endogenous CXCL-12, CXCR4, and NLRP1 were increased and peaked at 24 h following SAH. Immunofluorescence staining showed that CXCR4 was expressed on neurons, microglia, and astrocytes. Rh-CXCL-12 treatment improved the neurological deficits and reduced the number of FJC-positive cells, IL-18-positive neurons, and cleaved caspase-1(CC-1)-positive neurons after SAH. Meanwhile, rh-CXCL-12 treatment increased the levels of CXCL-12 and CXCR4, and reduced the levels of NLRP1, IL-18, IL-1β, and CC-1. Moreover, the administration of AMD3100 abolished antipyroptosis effects of CXCL-12 and its regulation of CXCR4 post-SAH. The CXCR4/NLRP1 signaling pathway may be involved in CXCL-12-mediated neuronal pyroptosis after SAH. Early administration of CXCL-12 may be a preventive and therapeutic strategy against brain injury after SAH.


Stroke ◽  
2021 ◽  
Author(s):  
Jun Yan ◽  
Weilin Xu ◽  
Cameron Lenahan ◽  
Lei Huang ◽  
Jing Wen ◽  
...  

Background and Purpose: Neuronal pyroptosis is a type of regulated cell death triggered by proinflammatory signals. CCR5 (C-C chemokine receptor 5)-mediated inflammation is involved in the pathology of various neurological diseases. This study investigated the impact of CCR5 activation on neuronal pyroptosis and the underlying mechanism involving cAMP-dependent PKA (protein kinase A)/CREB (cAMP response element binding)/NLRP1 (nucleotide-binding domain leucine-rich repeat pyrin domain containing 1) pathway after experimental intracerebral hemorrhage (ICH). Methods: A total of 194 adult male CD1 mice were used. ICH was induced by autologous whole blood injection. Maraviroc (MVC)—a selective antagonist of CCR5—was administered intranasally 1 hour after ICH. To elucidate the underlying mechanism, a specific CREB inhibitor, 666-15, was administered intracerebroventricularly before MVC administration in ICH mice. In a set of naive mice, rCCL5 (recombinant chemokine ligand 5) and selective PKA activator, 8-Bromo-cAMP, were administered intracerebroventricularly. Short- and long-term neurobehavioral assessments, Western blot, Fluoro-Jade C, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and immunofluorescence staining were performed. Results: The brain expression of CCL5 (chemokine ligand 5), CCR5, PKA-Cα (protein kinase A-Cα), p-CREB (phospho-cAMP response element binding), and NLRP1 was increased, peaking at 24 hours after ICH. CCR5 was expressed on neurons, microglia, and astrocytes. MVC improved the short- and long-term neurobehavioral deficits and decreased neuronal pyroptosis in ipsilateral brain tissues at 24 hours after ICH, which were accompanied by increased PKA-Cα and p-CREB expression, and decreased expression of NLRP1, ASC (apoptosis-associated speck-like protein containing a CARD), C-caspase-1, GSDMD (gasdermin D), and IL (interleukin)-1β/IL-18. Such effects of MVC were abolished by 666-15. At 24 hours after injection in naive mice, rCCL5 induced neurological deficits, decreased PKA-Cα and p-CREB expression in the brain, and upregulated NLRP1, ASC, C-caspase-1, N-GSDMD, and IL-1β/IL-18 expression. Those effects of rCCL5 were reversed by 8-Bromo-cAMP. Conclusions: CCR5 activation promoted neuronal pyroptosis and neurological deficits after ICH in mice, partially through the CCR5/PKA/CREB/NLRP1 signaling pathway. CCR5 inhibition with MVC may provide a promising therapeutic approach in managing patients with ICH.


2020 ◽  
Vol 19 (4) ◽  
pp. 727-737
Author(s):  
Fuchi Zhang ◽  
Kang Wu ◽  
Xiaolin Wu ◽  
Can Xin ◽  
Minghui Zhou ◽  
...  

Purpose: To investigate the effect of punicalagin, an ellagitannin present in pomegranates, on intracerebral haemorrhage (ICH)-induced inflammatory responses and oxidative stress, and also unravel the underlying mechanism(s) of action. Methods: Collagenase type IV (0.2 U) was used to induce ICH in adult male Sprague-Dawley rats. Punicalagin was given to the rats at doses of 25, 50, and 75 mg/kg body weight via oral gavage for 15 days before ICH induction. The animals were sacrificed 24h following induction of ICH, and their brains were excised immediately and used for analysis. Histological changes were determined with Haematoxylin and Eosin (H&E) staining. Permeability to blood-brain barrier (BBB) was determined by quantifying the extent of extravasation of Evan Blue (EB). Protein expressions of HO-1/Nrf-2/ARE and NF-κB signaling were assayed using immunoblotting and RT-PCR. Levels of reactive oxygen species (ROS) and serum levels of cytokines were also determined. Results: Punicalagin treatment reduced inflammatory cell infiltration and cell damage, improved brain tissue architecture and BBB integrity. The punicalagin treatment increased the activities of antioxidant enzymes, and enhanced antioxidant status via activation of Nrf-2/ARE/HO-1 signaling pathway (p < 0.05). The treatment upregulated the expressions of HO-1 to 174 %, relative to 127 % in ICH control rats. Furthermore, it enhanced NF-κB levels and reversed the ICH injury-induced upregulations of IL-6, IL-18 and IL-1β. Conclusion: These findings indicate that punicalagin exerts neuroprotective effect in rats after experimental ICH through regulation of theHO-1/Nrf-2/ARE signaling pathway. Thus, punicalagin has therapeutic potential for ICH. Keywords: Brain injury, Haemoxygenase-1, Intracerebral haemorrhage, Inflammatory responses, Nrf2/ARE signalling, Punicalagin


2021 ◽  
Author(s):  
Shengpeng Liu ◽  
Shuixiang Deng ◽  
Yan Ding ◽  
Jerry J. Flores ◽  
Xiaoli Zhang ◽  
...  

Abstract AimsGerminal matrix hemorrhage (GMH) is a disastrous clinical event for newborns. Neuroinflammation plays an important role in the development of neurological deficits after GMH. The purpose of this study is to investigate the anti-inflammatory role of secukinumab after GMH and its underlying mechanisms involving PKCβ/ERK/NF-κB signaling pathway.MethodsA total of 154 Sprague-Dawley P7 rat pups were used. GMH was induced by intraparenchymal injection of bacterial collagenase. Secukinumab was administered intranasally post-GMH. PKCβ activator PMA and p-ERK activator Ceramide C6 were administered intracerebroventricularly at 24h prior to GMH induction, respectively. Neurobehavioral tests, Western blot and immunohistochemistry were used to evaluate the efficacy of secukinumab in both short-term and long-term studies.ResultsEndogenous IL-17A, IL-17RA, PKCβ and p-ERK were increased after GMH. Secukinumab treatment improved short- and long-term neurological outcomes, reduced the expression of MPO and Iba-1 in the perihematoma area, and inhibited the expression of proinflammatory factors, such as NF-κB, IL-1β, TNF-α and IL-6. Additionally, PMA and ceramide C6 abolished the beneficial effects of secukinumab. ConclusionSecukinumab treatment suppressed neuroinflammation and attenuated neurological deficits after GMH, which was mediated through the downregulation of the PKCβ/ERK/NF-κB pathway. Secukinumab treatment may provide a promising therapeutic strategy for GMH patients.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Xu ◽  
Ya-min Zhang ◽  
Hua Sun ◽  
Su-hui Chen ◽  
Ying-kui Si

Background. While electroacupuncture (EA) in cerebral ischemia has been used to promote functional recovery, the underlying mechanism of its protective effect remains poorly understood.Objective. We investigated the effects of EA stimulation at GV20 and ST36 to observe the changes in erythropoietin- (EPO-) mediated Janus family tyrosine kinases 2 (JAK2) signal transducers and activators of the transcription 3 (STAT3) cell pathway.Methods. Thirty-six specific pathogen-free Sprague-Dawley (SD) male rats were randomly assigned to three groups: the sham-operated group (S group), the middle cerebral artery occlusion (MCAO) group (M group), and the EA group. Neurological deficits were assessed through the Ludmila Belayev 12-score test and 2,3,5-triphenyltetrazolium chloride (TTC) staining was shown. The protein and mRNA expression levels of EPO, the EPO receptor (EpoR), p-JAK2, JAK2, p-STAT3, and STAT3 were examined to explore the EA effect on rats with cerebral ischemic reperfusion injury (CIRI).Results. EA significantly decreased infarct size and improved neurological function. Furthermore, target EPO, EpoR, JAK2, and STAT3 mRNA and protein levels significantly increased in the EA group.Conclusions. EA exerts a neuroprotective effect, possibly via the regulation of the EPO-mediated JAK2/STAT3 cell pathway and downstream apoptotic pathways in a rat CIRI model.


2019 ◽  
Vol 28 (6) ◽  
pp. 756-766 ◽  
Author(s):  
Lianhua Zhao ◽  
John H. Zhang ◽  
Prativa Sherchan ◽  
Paul R. Krafft ◽  
Wei Zhao ◽  
...  

Targeting neuronal apoptosis after intracerebral hemorrhage (ICH) may be an important therapeutic strategy for ICH patients. Emerging evidence indicates that C1q/TNF-Related Protein 9 (CTRP9), a newly discovered adiponectin receptor agonist, exerts neuroprotection in cerebrovascular disease. The aim of this study was to investigate the anti-apoptotic role of CTRP9 after experimental ICH and to explore the underlying molecular mechanisms. ICH was induced in mice via intrastriatal injection of bacterial collagenase. Recombinant CTRP9 (rCTRP9) was administrated intranasally at 1 h after ICH. To elucidate the underlying mechanisms, adiponectin receptor1 small interfering ribonucleic acid (AdipoR1 siRNA) and selective PI3 K inhibitor LY294002 were administered prior to rCTRP9 treatment. Western blots, neurofunctional assessments, immunofluorescence staining, and Fluoro-Jade C (FJC) staining experiments were performed. Administration of rCTRP9 significantly improved both short- and long-term neurofunctional behavior after ICH. RCTRP9 treatment significantly increased the expression of AdipoR1, PI3 K, p-Akt, and Bcl-2, while at the same time was found to decrease the expression of Bax in the brain, which was reversed by inhibition of AdipoR1 and PI3 K. The neuroprotective effect of rCTRP9 after ICH was mediated by attenuation of neuronal apoptosis via the AdipoR1/PI3K/Akt signaling pathway; therefore, rCTRP9 should be further evaluated as a potential therapeutic agent for ICH patients.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Shufeng Yu ◽  
Desislava Met Doycheva ◽  
Marcin Gamdzyk ◽  
Yijun Yang ◽  
Cameron Lenahan ◽  
...  

Abstract Background Microglia-mediated neuroinflammation plays a crucial role in the pathogenesis of hypoxic-ischemic (HI)-induced brain injury. Activation of melanocortin-1 receptor (MC1R) has been shown to exert anti-inflammatory and neuroprotective effects in several neurological diseases. In the present study, we have explored the role of MC1R activation on neuroinflammation and the potential underlying mechanisms after neonatal hypoxic-ischemic brain injury in rats. Methods A total of 169 post-natal day 10 unsexed rat pups were used. HI was induced by right common carotid artery ligation followed by 2.5 h of hypoxia. BMS-470539, a specific selective MC1R agonist, was administered intranasally at 1 h after HI induction. To elucidate the potential underlying mechanism, MC1R CRISPR KO plasmid or Nurr1 CRISPR KO plasmid was administered via intracerebroventricular injection at 48 h before HI induction. Percent brain infarct area, short- and long-term neurobehavioral tests, Nissl staining, immunofluorescence staining, and Western blot were conducted. Results The expression levels of MC1R and Nurr1 increased over time post-HI. MC1R and Nurr1 were expressed on microglia at 48 h post-HI. Activation of MC1R with BMS-470539 significantly reduced the percent infarct area, brain atrophy, and inflammation, and improved short- and long-term neurological deficits at 48 h and 28 days post-HI. MC1R activation increased the expression of CD206 (a microglial M2 marker) and reduced the expression of MPO. Moreover, activation of MC1R with BMS-470539 significantly increased the expression levels of MC1R, cAMP, p-PKA, and Nurr1, while downregulating the expression of pro-inflammatory cytokines (TNFα, IL-6, and IL-1β) at 48 h post-HI. However, knockout of MC1R or Nurr1 by specific CRISPR reversed the neuroprotective effects of MC1R activation post-HI. Conclusions Our study demonstrated that activation of MC1R with BMS-470539 attenuated neuroinflammation, and improved neurological deficits after neonatal hypoxic-ischemic brain injury in rats. Such anti-inflammatory and neuroprotective effects were mediated, at least in part, via the cAMP/PKA/Nurr1 signaling pathway. Therefore, MC1R activation might be a promising therapeutic target for infants with hypoxic-ischemic encephalopathy (HIE).


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Christopher Sy ◽  
Xiaokun Geng ◽  
Paul Fu ◽  
Changya Peng ◽  
Vance Fredrickson ◽  
...  

Objectives: Normobaric oxygenation (NBO) has been reported to be neuroprotective against acute cerebral ischemia. Recently, a clinical trial was terminated because beneficial outcomes were not definitive. Our recent study ( Stroke. 2012 43(1):205-10 ) demonstrated a strong neuroprotective effect induced by acute administration of ethanol (EtOH) at 1.5g/kg. In this study, we assessed the therapeutic influence of EtOH in combination with NBO. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 2h. Ischemic animals received either an intraperitoneal injection of EtOH (1.0g/kg), a course of NBO (100% for 2h), or a combination of both immediately prior to reperfusion onset. Brain injury was determined by infarct volume and behavioral outcomes at 48h post-reperfusion. Metabolic dysfunction was investigated by assessing ADP/ATP ratios, reactive oxygen species (ROS) levels, NADPH oxidase (NOX) activity, and protein expression of NOX subunits (p47 phox , gp91 phox , and p67 phox ), as well as the protein expression and enzyme activity of pyruvate dehydrogenase (PDH), at both 3h and 24h after reperfusion. Results: Combination therapy led to a significant decrease in infarct volumes (Saline: 48±4%, EtOH: 38±3%, NBO: 37±4%, Combination: 19±3% ) and in neurological deficits (Belayev Scale 0-12, Saline: 8.4±0.7; EtOH: 6.5±0.7; NBO: 6.4±0.6; Combination: 4.4±0.3 ). At 3h and 24h post-reperfusion the decrease in ADP/ATP ratio was significantly enhanced, reflecting a preservation of cellular energy. A greater decrease in NOX activity and protein expression was observed, in association with decreased ROS levels, suggesting that improved glycolysis may contribute to neuroprotection. PDH activity and protein expression was dramatically increased, making the facilitation of aerobic metabolism a probable mechanism for preserving cellular ATP. Conclusions: Our findings demonstrate that a synergistic relationship exists between EtOH and NBO. Both are promising neuroprotective agents when used together, even at low doses. Moreover, both are inexpensive, widely available, easy to administer, and have little side effects. Thus, combination therapy could be an effective and efficient approach to future stroke treatments.


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