scholarly journals Loss of Gucy1a3 Causes Poor Post-Stroke Recovery by Reducing Angiogenesis Via the HIF-1α/VEGFA Signaling Pathway in Mice

Author(s):  
Man Luo ◽  
Dongcan Mo ◽  
LiuYu Liu ◽  
Jianli Li ◽  
Jing Lin ◽  
...  

Abstract Ischemic stroke is a common and debilitating disease that can cause permanent neurological damage. Gucy1a3, which encodes the α1 subunit of soluble guanylyl cyclase, has been reported to be associated with functional recovery after ischemic stroke. However, the mechanism is still not well understood. In the present study, we investigated the effects of Gucy1a3 on (i) post-stroke recovery; (ii) vascular endothelial growth factor A (VEGFA) and hypoxia inducible factor 1 alpha (HIF-1α) expression; and (iii) angiogenesis after ischemic stroke. A permanent middle cerebral artery occlusion (pMCAO) model was established using wild-type and Gucy1a3 knockout C57BL/6J male mice. Neurological deficits, infarct volume, microvascular density, and VEGFA and HIF-1α expression levels of mice were evaluated. Our results suggest that loss of Gucy1a3 increased the infarct volume and aggravated neurological deficits after pMCAO. In addition, the Gucy1a3 knockout brains exhibited significantly lower microvessel densities and VEGFA and HIF-1α expression levels than the wild-type brains at 96 hours post-pMCAO. The study shows that the expression of GUCY1A3 after ischemic stroke may play a substantial role in neurological function recovery and is related to angiogenesis in the peri-infarct region. The beneficial effects of GUCY1A3 might be mediated through the HIF-1α/VEGFA signaling pathway.

2021 ◽  
Vol 15 ◽  
Author(s):  
Yuhualei Pan ◽  
Dan Tian ◽  
Huan Wang ◽  
Yushang Zhao ◽  
Chengjie Zhang ◽  
...  

Perforin-mediated cytotoxicity plays a crucial role in microbial defense, tumor surveillance, and primary autoimmune disorders. However, the contribution of the cytolytic protein perforin to ischemia-induced secondary tissue damage in the brain has not been fully investigated. Here, we examined the kinetics and subpopulations of perforin-positive cells and then evaluated the direct effects of perforin-mediated cytotoxicity on outcomes after ischemic stroke. Using flow cytometry, we showed that perforin+CD45+ immune cells could be detected at 12 h and that the percentage of these cells increased largely until on day 3 and then significantly declined on day 7. Surprisingly, the percentage of Perforin+CD45+ cells also unexpectedly increased from day 7 to day 14 after ischemic stroke in Perforin1-EGFP transgenic mice. Our results suggested that Perforin+CD45+ cells play vital roles in the ischemic brain at early and late stages and further suggested that Perforin+CD45+ cells are a heterogeneous population. Surprisingly, in addition to CD8+ T cells, NK cells, and NKT cells, central nervous system (CNS)-resident immune microglia, which are first triggered and activated within minutes after ischemic stroke in mice, also secreted perforin during ischemic brain injury. In our study, the percentage of perforin+ microglia increased from 12 h after ischemic stroke, increased largely until on day 3 after ischemic stroke, and then moderately declined from days 3 to 7. Intriguingly, the percentage of perforin+ microglia also dramatically increased from days 7 to 14 after ischemic stroke. Furthermore, compared with wild-type littermates, Perforin 1–/– mice exhibited significant increases in the cerebral infarct volume, neurological deficits, and neurogenesis and inhibition of neurotoxic astrogliosis. Interestingly, the number of CD45+CD3+ T cells was significantly decreased in Perforin 1–/– mice compared with their wild-type littermates, especially the number of γδ T cells. In addition, Perforin 1–/– mice had lower levels of IL-17 than their wild-type littermates. Our results identified a critical function of perforin-mediated neurotoxicity in the ischemic brain, suggesting that targeting perforin-mediated neurotoxicity in brain-resident microglia and invading perforin+CD45+ immune cells may be a potential strategy for the treatment of ischemic stroke.


Author(s):  
Ri Yu ◽  
Nam-Suk Kim ◽  
Yan Li ◽  
Jin-Young Jeong ◽  
Sang-Joon Park ◽  
...  

AbstractPost-stroke vascular remodeling, including angiogenesis, facilitates functional recovery. Proper vascular repair is important for efficient post-stroke recovery; however, the underlying mechanisms coordinating the diverse signaling pathways involved in vascular remodeling remain largely unknown. Recently, axon guidance molecules were revealed as key players in injured vessel remodeling. One such molecule, Semaphorin 3E (Sema3E), and its receptor, Plexin-D1, control vascular development by regulating vascular endothelial growth factor (VEGF) signaling. In this study, using a mouse model of transient brain infarction, we aimed to investigate whether Sema3E-Plexin-D1 signaling was involved in cerebrovascular remodeling after ischemic injury. We found that ischemic damage rapidly induced Sema3e expression in the neurons of peri-infarct regions, followed by Plexin-D1 upregulation in remodeling vessels. Interestingly, Plexin-D1 reemergence was concurrent with brain vessels entering an active angiogenic process. In line with this, Plxnd1 ablation worsened neurological deficits, infarct volume, neuronal survival rate, and blood flow recovery. Furthermore, reduced and abnormal vascular morphogenesis was caused by aberrantly increased VEGF signaling. In Plxnd1 knockout mice, we observed significant extravasation of intravenously administered tracers in the brain parenchyma, junctional protein downregulation, and mislocalization in regenerating vessels. This suggested that the absence of Sema3E-Plexin-D1 signaling is associated with blood–brain barrier (BBB) impairment. Finally, the abnormal behavioral performance, aberrant vascular phenotype, and BBB breakdown defects in Plxnd1 knockout mice were restored following the inhibition of VEGF signaling during vascular remodeling. These findings demonstrate that Sema3E-Plexin-D1 signaling can promote functional recovery by downregulating VEGF signaling in the injured adult brain.


2022 ◽  
Vol 23 (2) ◽  
pp. 706
Author(s):  
Constanze Schanbacher ◽  
Michael Bieber ◽  
Yvonne Reinders ◽  
Deya Cherpokova ◽  
Christina Teichert ◽  
...  

Ischemic disorders are the leading cause of death worldwide. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) are thought to affect the outcome of ischemic stroke. However, it is under debate whether activation or inhibition of ERK1/2 is beneficial. In this study, we report that the ubiquitous overexpression of wild-type ERK2 in mice (ERK2wt) is detrimental after transient occlusion of the middle cerebral artery (tMCAO), as it led to a massive increase in infarct volume and neurological deficits by increasing blood–brain barrier (BBB) leakiness, inflammation, and the number of apoptotic neurons. To compare ERK1/2 activation and inhibition side-by-side, we also used mice with ubiquitous overexpression of the Raf-kinase inhibitor protein (RKIPwt) and its phosphorylation-deficient mutant RKIPS153A, known inhibitors of the ERK1/2 signaling cascade. RKIPwt and RKIPS153A attenuated ischemia-induced damages, in particular via anti-inflammatory signaling. Taken together, our data suggest that stimulation of the Raf/MEK/ERK1/2-cascade is severely detrimental and its inhibition is rather protective. Thus, a tight control of the ERK1/2 signaling is essential for the outcome in response to ischemic stroke.


2021 ◽  
Author(s):  
Yi-Hsin Wang ◽  
Jiuan-Miaw Liao ◽  
Ke-Min Chen ◽  
Hsing-Hui Su ◽  
Pei-Hsun Liu ◽  
...  

Abstract Background Ischemic stroke is characterized by the loss of cerebral blood flow, which frequently leads to neurological deficits. Therefore, minimizing post-stroke functional disability is an important research topic. The fibrinogen-depleting agent lumbrokinase has been used to improve myocardial perfusion in symptomatic stable angina and to prevent secondary ischemic stroke. In this study, we aimed to clarify the neuroprotection of lumbrokinase on ischemic stroke and whether improve neurological dysfunction. We explored the neuroprotection and the underlying mechanisms of lumbrokinase in C57BL/6 mice subjected to permanent middle cerebral artery occlusion. Results Lumbrokinase at 1 mg/kg significantly attenuated the infarct volume and improved the neurological dysfunction. Lumbrokinase dramatically decreased the expressions of the endoplasmic reticulum (ER) transmembrane receptor protein inositol-requiring enzyme-1 (IRE1) and its downstream transcription factor, X-box binding protein-1, caspase-12, and nuclear factor kappa B activity. Moreover, lumbrokinase significantly inhibited apoptosis and autophagy and decreased the expression levels of the NOD-like receptor 3 inflammasome, caspase-1, and interleukin-1β compared with the vehicle treatment. Conclusions We suggest that post-stroke treatment with lumbrokinase protects against ischemic stroke by regulating ER stress through the IRE1 signaling pathways to inhibit apoptosis, autophagy, and inflammatory responses.


2020 ◽  
Vol 26 (26) ◽  
pp. 3115-3121
Author(s):  
Jun Yang ◽  
Jingjing Zhao ◽  
Xu Liu ◽  
Ruixia Zhu

LncRNAs (long non-coding RNAs) are endogenous molecules, involved in complicated biological processes. Increasing evidence has shown that lncRNAs play a vital role in the post-stroke pathophysiology. Furthermore, several lncRNAs were reported to mediate ischemia cascade processes include apoptosis, bloodbrain barier breakdown, angiogenesis, microglial activation induced neuroinflammation which can cause neuron injury and influence neuron recovery after ischemic stroke. In our study, we first summarize current development about lncRNAs and post-stroke, focus on the regulatory roles of lncRNAs on pathophysiology after stroke. We also reviewed genetic variation in lncRNA associated with functional outcome after ischemic stroke. Additionally, lncRNA-based therapeutics offer promising strategies to decrease brain damage and promote neurological recovery following ischemic stroke. We believe that lncRNAs will become promising for the frontier strategies for IS and can open up a new path for the treatment of IS in the future.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Douglas M Bennion ◽  
Lauren Donnangelo ◽  
David Pioquinto ◽  
Robert Regenhardt ◽  
Mohan K Raizada ◽  
...  

Background: Toward discovering novel stroke therapies, recent research has shown that activation of the newly-discovered angiotensin converting enzyme 2/angiotensin-(1-7)/mas (ACE2/Ang-(1-7)/Mas) pathway, a counter-regulatory axis of the brain renin-angiotensin system, is neuroprotective in ischemic stroke in rats. Specifically, intraventricular administration of the novel ACE2 activator diminazine aceturate (DIZE) before and during an ischemic stroke decreases cerebral infarct and neurologic deficits. Efficacy must now be demonstrated using minimally-invasive methods if this therapy is to be translated to the care of human patients. In this study, we assessed the hypothesis that systemic administration of DIZE post ischemic stroke would be neuroprotective. Methods: Adult male Sprague-Dawley rats underwent ischemic stroke by endothelin-1 induced middle cerebral artery occlusion and were randomly divided into 2 groups (n=9-10/set): 1) intraperitoneal (IP) administrations of DIZE (7.5 mg/kg) at 4, 24, and 48 h after stroke; 2) IP administrations of 0.9% saline vehicle at the same time points. At 24 and 72 h after stroke, rats underwent blinded neurologic assessments. Immediately following the 72 h tests, animals were sacrificed, cerebral infarct volumes assessed by TTC staining, and IL-1β expression in the stroke region analyzed by rt-PCR. Data are expressed as mean ± SEM with significance inferred at p<0.05. Results: Mean infarct volume was significantly decreased by IP injections of DIZE (9.4% ± 4.35) as compared to control (22.8%±3.6, p=0.039). At 24 h post stroke, neurologic deficits (Garcia Scale) were significantly improved in the DIZE treated group (16.7±0.40) versus the saline group (15.22±0.57, p=0.037). Although DIZE tended to improve neurologic deficits 72 h post stroke, this trend was not significant. Finally, DIZE treatment significantly reduced mRNA expression of IL-1β (0.43 ± 0.14) in the cerebral cortical stroke region as compared to saline treatment (1.47±0.08, p=0.001). Conclusions: Our findings suggest that targeting the ACE2/Ang-(1-7)/Mas axis post stroke can improve function, decrease inflammation, and reduce infarct volume - a significant translational step in brain renin-angiotensin system research.


2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Xiao Hu ◽  
Shirong Li ◽  
Desislava Met Doycheva ◽  
Lei Huang ◽  
Cameron Lenahan ◽  
...  

Oxidative stress (OS) and neuronal apoptosis are major pathological processes after hypoxic-ischemic encephalopathy (HIE). Colony stimulating factor 1 (CSF1), binding to CSF1 receptor (CSF1R), has been shown to reduce neuronal loss after hypoxic-ischemia- (HI-) induced brain injury. In the present study, we hypothesized that CSF1 could alleviate OS-induced neuronal degeneration and apoptosis through the CSF1R/PLCG2/PKA/UCP2 signaling pathway in a rat model of HI. A total of 127 ten-day old Sprague Dawley rat pups were used. HI was induced by right common carotid artery ligation with subsequent exposure to hypoxia for 2.5 h. Exogenous recombinant human CSF1 (rh-CSF1) was administered intranasally at 1 h and 24 h after HI. The CSF1R inhibitor, BLZ945, or phospholipase C-gamma 2 (PLCG2) inhibitor, U73122, was injected intraperitoneally at 1 h before HI induction. Brain infarct volume measurement, cliff avoidance test, righting reflex test, double immunofluorescence staining, western blot assessment, 8-OHdG and MitoSOX staining, Fluoro-Jade C staining, and TUNEL staining were used. Our results indicated that the expressions of endogenous CSF1, CSF1R, p-CSF1R, p-PLCG2, p-PKA, and uncoupling protein2 (UCP2) were increased after HI. CSF1 and CSF1R were expressed in neurons and astrocytes. Rh-CSF1 treatment significantly attenuated neurological deficits, infarct volume, OS, neuronal apoptosis, and degeneration at 48 h after HI. Moreover, activation of CSF1R by rh-CSF1 significantly increased the brain tissue expressions of p-PLCG2, p-PKA, UCP2, and Bcl2/Bax ratio, but reduced the expression of cleaved caspase-3. The neuroprotective effects of rh-CSF1 were abolished by BLZ945 or U73122. These results suggested that rh-CSF1 treatment attenuated OS-induced neuronal degeneration and apoptosis after HI, at least in part, through the CSF1R/PLCG2/PKA/UCP2 signaling pathway. Rh-CSF1 may serve as therapeutic strategy against brain damage in patients with HIE.


2018 ◽  
Vol 48 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Qingqing Wang ◽  
Chengmei Lv ◽  
Yongxin Sun ◽  
Xu Han ◽  
Shan Wang ◽  
...  

Background/Aims: Ischemic stroke results in increased cerebral infarction, neurological deficits and neuroinflammation. The underlying mechanisms involving the anti-inflammatory and neuroprotective properties of α-Lipoic acid (α-LA) remain poorly understood. Herein, we investigated the potential role of α-LA in a middle cerebral artery occlusion (MCAO) rat model and an in vitro lipopolysaccharide (LPS)-induced microglia inflammation model. Methods: In the in vivo study, infarct volume was examined by TTC staining and Garcia score was used to evaluate neurologic recovery. The cytokines were evaluated by enzyme-linked immunosorbent assay, and protein expression of microglia phenotype and NF-κB were measured using western blot. In the in vitro study, the expressions of microglia M1/M2 phenotype were evaluated using qRT-PCR, and immunofluorescence staining was used to assess the nuclear translocation of NF-κB. Results: Both 20 mg/kg and 40 mg/kg of α-LA alleviated infarct size, brain edema, and neurological deficits. Furthermore, α-LA induced the polarization of microglia to the M2 phenotype, modulated the expression of IL-1β, IL-6, TNF-α and IL-10, and attenuated the activation of NF-κB after MCAO. α-LA inhibited the expression of M1 markers, increased activation of the M2 markers, and suppressed the nuclear translocation of NF-κB in LPS-stimulated BV2 microglia. Conclusions: α-LA improved neurological outcome in experimental stroke via modulating microglia M1/M2 polarization. The potential mechanism of α-LA might be mediated by inhibition of NF-κB activation via regulating phosphorylation and nuclear translocation of p65.


2019 ◽  
Vol 97 (6) ◽  
pp. 702-708 ◽  
Author(s):  
Ting Wang ◽  
Yu-Mei Duan ◽  
Qiao Fu ◽  
Tao Liu ◽  
Jin-Cheng Yu ◽  
...  

Hemorrhagic transformation (HT) is a devastating complication for patients with acute ischemic stroke (AIS) who are treated with tissue plasminogen activator (tPA). HT is associated with high morbidity and mortality, but no effective treatments are currently available to reduce the risk of HT. Therefore, methods to prevent HT are urgently needed. In this study, we used IM-12, an inhibitor of glycogen synthase kinase 3β (GSK-3β), to evaluate the role of the Wnt–β-catenin signaling pathway in recombinant tPA (rtPA)-induced HT. Sprague–Dawley rats were subjected to a middle cerebral artery occlusion (MCAO) model of ischemic stroke, and then were either administered rtPA, rtPA combined with IM-12, or the vehicle at 4 h after stroke was induced. Our results indicate that rats subjected to HT had more severe neurological deficits, brain edema, and blood–brain barrier (BBB) breakdown, and had a greater infarction volume than the control group. Rats treated with IM-12 had improved outcomes compared with those of rats treated with rtPA alone. Moreover, IM-12 increased the protein expression of β-catenin and downstream proteins while suppressing the expression of GSK-3β. These results suggest that IM-12 reduces rtPA-induced HT and attenuates BBB disruption, possibly through activation of the Wnt–β-catenin signaling pathway, and provides a potential therapeutic strategy for preventing tPA-induced HT after AIS.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 330-330
Author(s):  
Anil Chauhan ◽  
Mohammad M Khan ◽  
Chintan Gandhi ◽  
Neelam Chauhan ◽  
Asgar Zaheer ◽  
...  

Abstract Abstract 330 Background: Fibronectin (FN) is a dimeric glycoprotein that plays an important role in several cellular processes, such as embryogenesis, malignancy, hemostasis, wound healing and maintenance of tissue integrity. FN is a ligand for many members of the integrin family (e.g. αIIbβ3, α5β1, α4β1, α9β1, αvβ3 and αvβ5) and also binds to thrombosis-related proteins including heparin, collagen and fibrin. FN generates protein diversity as a consequence of alternative processing of a single primary transcript. Two forms of FN exist; soluble plasma FN (pFN), which lacks the alternatively-spliced Extra Domain A (EDA); and insoluble cellular FN (cFN), which contains EDA. FN containing EDA (EDA+FN) is normally absent in plasma of human and mouse but EDA+FN has been found in patients with vascular injury secondary to vasculitis, sepsis, acute major trauma or ischemic stroke. We tested the hypothesis that elevated levels of plasma EDA+FN increase brain injury in an experimental model of ischemic stroke in mice. Model and Method: We used two genetically modified mouse strains: EDA+/+ mice contain optimized spliced sites at both splicing junctions of the EDA exon and constitutively express only EDA+FN, whereas EDA-/- mice contain an EDA-null allele of the EDA exon and express only FN lacking EDA. Control EDAwt/wt mice contain the wild-type FN allele. Transient focal cerebral ischemia was induced by 60 minutes of occlusion of the right middle cerebral artery with a 7.0 siliconized filament in male mice (8-10 weeks in age). Mice were anesthetized with 1–1.5% isoflurane mixed with medical air. Body temperature was maintained at 37°C ± 1.0 using a heating pad. Laser Doppler flowmetry was used to confirm induction of ischemia and reperfusion. At 23 hours after MCAO, mice were evaluated for neurological deficits as a functional outcome and were sacrificed for quantification of infarct volume. For morphometric measurement eight 1 mm coronal sections were stained with 2% triphenyl-2, 3, 4-tetrazolium-chloride (TTC). Sections were digitalized and infarct areas were measured blindly using NIS elements. Result: In EDA+/+ mice the percentage of infarct volume (mean ± SEM: 37.25 ± 4.11, n= 12,) in the ipsilateral (ischemic) hemisphere was increased by approximately two-fold compared to EDA wt/wt mice (mean ± SEM: 22.33 ± 3.39, n=11; P< 0.05, ANOVA) or EDA-/- mice (mean ± SEM: 21.72 ± 2.94, n=9). Regional cerebral blood flow during ischemia was not different among groups as assessed by laser Doppler flowmetry. The percentage increase in infarct volume in the EDA+/+ mice correlated well with severe neurological deficits (motor-deficit assessed by a four-point neurological score scale) compared to EDA wt/wt or EDA-/- mice. Because both thrombosis and inflammation contributes to brain injury during ischemic stroke, we investigated the time to form an occlusive thrombus in ferric-chloride carotid artery injury model by intravital microscopy. EDA+/+ mice demonstrated significantly faster time to occlusion (mean ± SEM: 12.35 ± 1.51 n=12,) compared to EDAwt/wt (Mean ± SEM: 17.27 ± 1.72 min, n=13, P<0.05, ANOVA) or EDA-/- (Mean ± SEM: 15.61 ± 1.76, n=11) mice. Additionally, the inflammatory response in the ischemic region was increased by two fold in EDA+/+ mice compared to EDA wt/wt and EDA-/- mice as sensed by myeloperoxidase activity and immunohistochemical analysis of neutrophils. Conclusion: EDA-containing FN is pro-thrombotic and pro-inflammatory, and aggravates ischemic brain injury in an experimental model of stroke in mice. The presence of EDA+FN in plasma may be a risk factor for vascular injury secondary to ischemic stroke. Disclosures: No relevant conflicts of interest to declare.


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