scholarly journals High-Density Lipoprotein Therapy in Stroke: Evaluation of Endothelial SR-BI-Dependent Neuroprotective Effects

2020 ◽  
Vol 22 (1) ◽  
pp. 106
Author(s):  
Alexy Tran-Dinh ◽  
Angélique Levoye ◽  
David Couret ◽  
Lauriane Galle-Treger ◽  
Martine Moreau ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Infarct Volume ◽  
High Density ◽  
High Density Lipoproteins ◽  
Protective Effects ◽  
Neuroprotective Effects

High-density lipoproteins (HDLs) display endothelial protective effects. We tested the role of SR-BI, an HDL receptor expressed by endothelial cells, in the neuroprotective effects of HDLs using an experimental model of acute ischemic stroke. After transient intraluminal middle cerebral artery occlusion (tMCAO), control and endothelial SR-BI deficient mice were intravenously injected by HDLs or saline. Infarct volume and blood-brain barrier (BBB) breakdown were assessed 24 h post tMCAO. The potential of HDLs and the role of SR-BI to maintain the BBB integrity was assessed by using a human cellular model of BBB (hCMEC/D3 cell line) subjected to oxygen-glucose deprivation (OGD). HDL therapy limited the infarct volume and the BBB leakage in control mice relative to saline injection. Interestingly, these neuroprotective effects were thwarted by the deletion of SR-BI in endothelial cells and preserved in mice deficient for SR-BI in myeloid cells. In vitro studies revealed that HDLs can preserve the integrity of the BBB in OGD conditions, and that this effect was reduced by the SR-BI inhibitor, BLT-1. The protection of BBB integrity plays a pivotal role in HDL therapy of acute ischemic stroke. Our results show that this effect is partially mediated by the HDL receptor, SR-BI expressed by endothelial cells.

scholarly journals Sirtuin 3 Mediates Neuroprotection of Ketones against Ischemic Stroke

2015 ◽  
Vol 35 (11) ◽  
pp. 1783-1789 ◽  
Author(s):  
Junxiang Yin ◽  
Pengcheng Han ◽  
Zhiwei Tang ◽  
Qingwei Liu ◽  
Jiong Shi
Keyword(s):  
Ischemic Stroke ◽  
Ketone Bodies ◽  
Infarct Volume ◽  
Field Tests ◽  
Underlying Mechanism ◽  
Sirtuin 3 ◽  
Neuroprotective Effects ◽  
Beneficial Effects ◽  
Beta Hydroxybutyrate

Stroke is one of the leading causes of death. Growing evidence indicates that ketone bodies have beneficial effects in treating stroke, but their underlying mechanism remains unclear. Our previous study showed ketone bodies reduced reactive oxygen species by using NADH as an electron donor, thus increasing the NAD+/NADH ratio. In this study, we investigated whether mitochondrial NAD+-dependent Sirtuin 3 (SIRT3) could mediate the neuroprotective effects of ketone bodies after ischemic stroke. We injected mice with either normal saline or ketones (beta-hydroxybutyrate and acetoacetate) at 30 minutes after ischemia induced by transient middle cerebral artery (MCA) occlusion. We found that ketone treatment enhanced mitochondria function, reduced oxidative stress, and therefore reduced infarct volume. This led to improved neurologic function after ischemia, including the neurologic score and the performance in Rotarod and open field tests. We further showed that ketones' effects were achieved by upregulating NAD+-dependent SIRT3 and its downstream substrates forkhead box O3a (FoxO3a) and superoxide dismutase 2 (SOD2) in the penumbra region since knocking down SIRT3 in vitro diminished ketones' beneficial effects. These results provide us a foundation to develop novel therapeutics targeting this SIRT3-FoxO3a-SOD2 pathway.

scholarly journals Evidence for the role of high density lipoproteins in mediating the antioxidant effect of estrogens

2000 ◽  
pp. 79-83 ◽  
Author(s):  
W Abplanalp ◽  
MD Scheiber ◽  
K Moon ◽  
B Kessel ◽  
JH Liu ◽  
...  
Keyword(s):  
Density Lipoprotein ◽  
Antioxidant Effect ◽  
High Density ◽  
In Vivo Studies ◽  
Ldl Oxidation ◽  
High Density Lipoproteins ◽  
Oh Groups

Estrogens possess strong antioxidant effects in vitro, but in vivo studies in humans have yielded conflicting results. Little is known regarding factors that mediate the antioxidant effect of estrogens in vivo. In this study the potential role of high density lipoprotein (HDL) was examined. The antioxidant effect of estradiol-17beta (E2) added to low density lipoprotein (LDL) was lost after dialysis. In contrast, the antioxidant effect of E2 added to HDL was conserved after dialysis, suggesting that E2 was bound to HDL. Binding of E2 to LDL increased after esterification (especially to long chain fatty acids). In the presence of HDL, an increased amount of E2 was transferred to LDL. E2-17 ester was as potent as E2 in preventing LDL oxidation in vitro, but 3,17-diesters were not as effective (E2=E2-17 ester>E2-3 ester>E2-3,17 diester). This was also supported by experiments which showed that estrogens with masked 3-OH groups were not effective as antioxidants. These studies provide evidence that HDL could facilitate the antioxidant effect of E2 through initial association, esterification and eventual transfer of E2 esters to LDL. Therefore it is critical that HDL peroxidation parameters be evaluated in subjects receiving estrogen replacement therapy.

scholarly journals The Role of Alpha-Lipoic Acid in the Pathomechanism of Acute Ischemic Stroke

2018 ◽  
Vol 48 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Qingqing Wang ◽  
Chengmei Lv ◽  
Yongxin Sun ◽  
Xu Han ◽  
Shan Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Lipoic Acid ◽  
Nuclear Translocation ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Enzyme Linked Immunosorbent Assay ◽  
M2 Phenotype

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.

scholarly journals Vepoloxamer Enhances Fibrinolysis of tPA (Tissue-Type Plasminogen Activator) on Acute Ischemic Stroke

Stroke ◽  
2019 ◽  
Vol 50 (12) ◽  
pp. 3600-3608 ◽  
Author(s):  
Chunyang Wang ◽  
Rui Huang ◽  
Chao Li ◽  
Mei Lu ◽  
Martin Emanuele ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Plasminogen Activator ◽  
Combination Treatment ◽  
Infarct Volume ◽  
Brain Perfusion ◽  
Artery Occlusion ◽  
Tissue Type ◽  
Pai 1

Background and Purpose— Thrombolytic treatment of acute ischemic stroke with tPA (tissue-type plasminogen activator) is hampered by its narrow therapeutic window and potential hemorrhagic complication. Vepoloxamer is a nonionic surfactant that exerts potent hemorheologic and antithrombotic properties in various thrombotic diseases. The current study investigated the effect of vepoloxamer on tPA treatment in a rat model of embolic stroke. Methods— Male Wistar rats subjected to embolic middle cerebral artery occlusion were treated with the combination of vepoloxamer and tPA, vepoloxamer alone, tPA alone, or saline initiated 4 hours after middle cerebral artery occlusion. Results— Monotherapy with tPA did not reduce infarct volume, and adversely potentiated microvascular thrombosis and vascular leakage compared with the saline treatment. Vepoloxamer monotherapy reduced infarct volume by 25% and improved brain perfusion. However, the combination treatment with vepoloxamer and tPA significantly reduced infarct volume by 32% and improved neurological function, without increasing the incidence of gross hemorrhage. Compared with vepoloxamer alone, the combination treatment with vepoloxamer and tPA robustly reduced secondary thrombosis and tPA-augmented microvascular leakage and further improved brain perfusion, which was associated with substantial reductions of serum active PAI-1 (plasminogen activator inhibitor-1) level and tPA-upregulated PAI-1 in the ischemic brain. Mechanistically, exosomes derived from platelets of ischemic rats treated with tPA-augmented cerebral endothelial barrier permeability and elevated protein levels of PAI-1 and TF (tissue factor) in the endothelial cells, whereas exosomes derived from platelets of rats subjected to the combination treatment with vepoloxamer and tPA diminished endothelial permeability augmented by tPA and fibrin and reduced PAI-1 and TF levels in the endothelial cells. Conclusions— The combination treatment with vepoloxamer and tPA exerts potent thrombolytic effects in rats subjected to acute ischemic stroke. Vepoloxamer reduces tPA-aggravated prothrombotic effect of platelet-derived exosomes on cerebral endothelial cells, which may contribute to the therapeutic effect of the combination treatment.

scholarly journals High-Density Lipoproteins Limit Neutrophil-Induced Damage to the Blood–Brain Barrier in Vitro

2013 ◽  
Vol 33 (4) ◽  
pp. 575-582 ◽  
Author(s):  
Quoc Bao Dang ◽  
Bertrand Lapergue ◽  
Alexy Tran-Dinh ◽  
Devy Diallo ◽  
Juan-Antonio Moreno ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Blood Brain Barrier ◽  
Extracellular Matrix Proteins ◽  
High Density ◽  
Matrix Proteins ◽  
Brain Barrier ◽  
High Density Lipoproteins ◽  
Blood Brain

Breakdown of the blood–brain barrier (BBB) is a key step associated with ischemic stroke and its increased permeability causes extravasation of plasma proteins and circulating leukocytes. Polymorphonuclear neutrophil (PMN) proteases may participate in BBB breakdown. We investigated the role of PMNs in ischemic conditions by testing their effects on a model of BBB in vitro, under oxygen-glucose deprivation (OGD) to mimic ischemia, supplemented or not with high-density lipoproteins (HDLs) to assess their potential protective effects. Human cerebral endothelial cells cultured on transwells were incubated for 4 hours under OGD conditions with or without PMNs and supplemented or not with HDLs or alpha-1 antitrypsin (AAT, an elastase inhibitor). The integrity of the BBB was then assessed and the effect of HDLs on PMN-induced proteolysis of extracellular matrix proteins was evaluated. The release of myeloperoxidase and matrix metalloproteinase 9 (MMP-9) by PMNs was quantified. Polymorphonuclear neutrophils significantly increased BBB permeability under OGD conditions via proteolysis of extracellular matrix proteins. This was associated with PMN degranulation. Addition of HDLs or AAT limited the proteolysis and associated increased permeability by inhibiting PMN activation. Our results suggest a deleterious, elastase-mediated role of activated PMNs under OGD conditions leading to BBB disruption that could be inhibited by HDLs.

scholarly journals The Neuroprotective Effects of Insulin-Like Growth Factor 1 via the Hippo/YAP Signaling Pathway is Mediated by the PI3K/AKT Pathway Following Cerebral Ischemia-Reperfusion Injury

2021 ◽  
Author(s):  
Pian Gong ◽  
Yichun Zou ◽  
Wei Zhang ◽  
Qi Tian ◽  
Shoumeng Han ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Growth Factor ◽  
Signaling Pathway ◽  
Neuronal Death ◽  
Infarct Volume ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Neuroprotective Effects

Abstract Insulin-like growth factor 1 (IGF-1) exhibits neuroprotective properties, such as vasodilatory and anti-inflammatory effects following ischemic stroke. However, the specific molecular mechanisms of action of IGF-1 following ischemic stroke remain elusive. We wanted to explore whether IGF-1 regulates Hippo/YAP signaling pathway, potentially via activation of the PI3K/AKT signaling pathway to exert its neuroprotective effects following ischemic stroke. In the in vitro study, we used oxygen–glucose deprivation to injure cultured PC12 and SH-5YSY cells, and cortical primary neurons. Cell viability was measured using CCK-8 assay. For the in vivo analyses, Sprague–Dawley rats were subjected to middle cerebral artery occlusion; neurological function was assessed using the neurological deficit score; infarct volume was measured using triphenyltetrazolium chloride staining, and neuronal death and apoptosis was evaluated by TUNEL staining, H&E staining and Nissl staining. Western blot was used to measure the levels of YAP/TAZ, PI3K and phosphorylated AKT (p-AKT) both in vitro and in vivo. We found that IGF-1 induced activation of YAP/TAZ, which resulted in improved cell viability in vitro, and decreased neurological deficits, neuronal death and apoptosis, and cerebral infarct volume in vivo. Notably, the neuroprotective effects of IGF-1 were reversed by an inhibitor of the PI3K/AKT signaling pathway, LY294002, which not only reduced expressions of PI3K and p-AKT, but also down-regulated expression of YAP/TAZ, leading to aggravation of neurological dysfunction. These findings indicate that neuroprotective effect of IGF-1 is partly realized by up-regulation of YAP/TAZ, which is mediated by activation of the PI3K/AKT signaling pathway following cerebral ischemic stroke.

Abstract 202: Sex Differences In Ischemic Stroke: The Role Of Genetic Sex

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
BHARTI MANWANI ◽  
Venugopal Reddy Venna ◽  
Arthur P Arnold ◽  
Sami Tarabishy ◽  
Louise D McCullough
Keyword(s):  
Sex Differences ◽  
Ischemic Stroke ◽  
Sex Chromosome ◽  
Cresyl Violet ◽  
Specific Cell ◽  
Protective Effects ◽  
Sry Gene ◽  
Neuroprotective Effects ◽  
Stroke Incidence

Background/Purpose— Ischemic stroke is now recognized as a sexually dimorphic disease with women enjoying lower stroke incidence relative to men until an advanced age. This has largely been attributed to the neuroprotective effects of estrogen in females. However, recent failure of estrogen supplementation clinical trials and in vitro studies showing differences in ischemic sensitivity in sex steroid depleted media, suggest that factors other than hormones may shape this dichotomy. Since the sex chromosomal complement differs in men (XY) and women (XX), this may contribute to the underlying etiology of sex differences. The objective of this study was to investigate the genetic sex contributions to the etiology of sex differences in cerebral ischemia. Since it is extremely difficult to dissect the effects of sex chromosomes from hormones, we used a four core genotype (FCG) mouse model in this study where, Sry, the testis determining gene is deleted from the Y chromosome and inserted on an autosome in XY - SryMale(XYM). The four different genotypes, XXM(XX male), XYM(XY male), XXF(XX female) and XYF(XY female) derived by a cross between XXF and XYM can be compared to study the influence of sex chromosome(XX/XY) or sex(Sry/hormones) in stroke sensitivity. Methods— Stroke was induced by 90 minutes MCAO in FCG mice. Histological assessment was performed at 24 and 72 hours after stroke using cresyl violet staining. Sry PCR was done on brain samples from these mice. Results— At 24 hrs after MCAO, XXF’s(18.7±1.6%) and XYF’s(15.6±4%) had significantly smaller total hemispheric infarcts compared to either XYM’s(35±6.8%) or XXM’s(28±6.5%). ANOVA revealed a main effect of sex, F(1,12)=4.9,p<0.05. Hemispheric infarcts at 72 hours post stroke show a similar trend, with XXF’s(22±3.2%) and XYF’s(21±1%) having smaller hemispheric infarcts vs. XYM’s(35±7%) or XXM’s(30±2%). Sry mRNA expression was seen in brains of XXM’s and XYM’s. Conclusions- We found a sex effect in this study as all mice with Sry gene(XXM, XYM) had higher injury. It remains possible that these effects were secondary to the protective effects of estrogen (in XXF and XYF). However, this is unlikely as our preliminary studies have shown that XYF’s have very low estrogen levels (equivalent to males). Thus, we conclude that these differences may be due to the detrimental effects of Sry gene in the male brain. It is speculated that Sry may be the missing piece of puzzle that mediates sex specific cell death after stroke. Studies in gonadectomized FCG mice to further dissociate hormonal effects from direct effects of Sry are ongoing.

scholarly journals HMGB1-triggered inflammation inhibition of notoginseng leaf triterpenes against cerebral ischemia and reperfusion injury via MAPK and NF-κB signaling pathways

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 512 ◽  
Author(s):  
Xie ◽  
Zhu ◽  
Dong ◽  
Nan ◽  
Meng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Infarct Volume ◽  
Neuronal Loss ◽  
Ischemia And Reperfusion ◽  
Protective Effects ◽  
Ischemia And Reperfusion Injury ◽  
Neuroprotective Effects ◽  
Cerebral Ischemia And Reperfusion

Ischemic stroke is a clinically common cerebrovascular disease whose main risks include necrosis, apoptosis and cerebral infarction, all caused by cerebral ischemia and reperfusion (I/R) injury. This process has particular significance for the treatment of stroke patients. Notoginseng leaf triterpenes (PNGL), as a valuable medicine, have been discovered to have neuroprotective effects. However, it was not confirmed that whether PNGL may possess neuroprotective effects against cerebral I/R injury. To explore the neuroprotective effects of PNGL and their underlying mechanisms, a middle cerebral artery occlusion/reperfusion (MCAO/R) model was established. In vivo results suggested that in MCAO/R model rats, PNGL pretreatment (73.0, 146, 292 mg/kg) remarkably decreased infarct volume, reduced brain water content, and improved neurological functions; moreover, PNGL (73.0, 146, 292 mg/kg) significantly alleviated blood-brain barrier (BBB) disruption and inhibited neuronal apoptosis and neuronal loss caused by cerebral I/R injury, while PNGL with a different concertation (146, 292 mg/kg) significantly reduced the concentrations of IL-6, TNF-α, IL-1 β, and HMGB1 in serums in a dose-dependent way, which indicated that inflammation inhibition could be involved in the neuroprotective effects of PNGL. The immunofluorescence and western blot analysis showed PNGL decreased HMGB1 expression, suppressed the HMGB1-triggered inflammation, and inhibited microglia activation (IBA1) in hippocampus and cortex, thus dose-dependently downregulating inflammatory cytokines including VCAM-1, MMP-9, MMP-2, and ICAM-1 concentrations in ischemic brains. Interestingly, PNGL administration (146 mg/kg) significantly downregulated the levels of p-P44/42, p-JNK1/2 and p-P38 MAPK, and also inhibited expressions of the total NF-κB and phosphorylated NF-κB in ischemic brains, which was the downstream pathway triggered by HMGB1. All of these results indicated that the protective effects of PNGL against cerebral I/R injury could be associated with inhibiting HMGB1-triggered inflammation, suppressing the activation of MAPKs and NF-κB, and thus improved cerebral I/R-induced neuropathological changes. This study may offer insight into discovering new active compounds for the treatment of ischemic stroke.

scholarly journals Neuroprotective Effects of Guanosine in Ischemic Stroke—Small Steps towards Effective Therapy

2021 ◽  
Vol 22 (13) ◽  
pp. 6898
Author(s):  
Karol Chojnowski ◽  
Mikolaj Opielka ◽  
Wojciech Nazar ◽  
Przemyslaw Kowianski ◽  
Ryszard T. Smolenski
Keyword(s):  
Ischemic Stroke ◽  
Brain Ischemia ◽  
Excitatory Amino Acid ◽  
Infarct Volume ◽  
In Vivo Studies ◽  
Amino Acid Transporters ◽  
Tissue Slices ◽  
Neuroprotective Effects

Guanosine (Guo) is a nucleotide metabolite that acts as a potent neuromodulator with neurotrophic and regenerative properties in neurological disorders. Under brain ischemia or trauma, Guo is released to the extracellular milieu and its concentration substantially raises. In vitro studies on brain tissue slices or cell lines subjected to ischemic conditions demonstrated that Guo counteracts destructive events that occur during ischemic conditions, e.g., glutaminergic excitotoxicity, reactive oxygen and nitrogen species production. Moreover, Guo mitigates neuroinflammation and regulates post-translational processing. Guo asserts its neuroprotective effects via interplay with adenosine receptors, potassium channels, and excitatory amino acid transporters. Subsequently, guanosine activates several prosurvival molecular pathways including PI3K/Akt (PI3K) and MEK/ERK. Due to systemic degradation, the half-life of exogenous Guo is relatively low, thus creating difficulty regarding adequate exogenous Guo distribution. Nevertheless, in vivo studies performed on ischemic stroke rodent models provide promising results presenting a sustained decrease in infarct volume, improved neurological outcome, decrease in proinflammatory events, and stimulation of neuroregeneration through the release of neurotrophic factors. In this comprehensive review, we discuss molecular signaling related to Guo protection against brain ischemia. We present recent advances, limitations, and prospects in exogenous guanosine therapy in the context of ischemic stroke.

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