scholarly journals Intranasal Delivery of RGD-Containing Osteopontin Heptamer Peptide Confers Neuroprotection in the Ischemic Brain and Augments Microglia M2 Polarization

2021 ◽  
Vol 22 (18) ◽  
pp. 9999
Author(s):  
Dashdulam Davaanyam ◽  
Il-Doo Kim ◽  
Ja-Kyeong Lee

Osteopontin (OPN), a phosphorylated glycoprotein, is induced in response to tissue damage and inflammation in various organs, including the brain. In our previous studies, we reported the robust neuroprotective effects of the icosamer OPN peptide OPNpt20, containing arginine-glycine-aspartic acid (RGD) and serine-leucine-alanine-tyrosine (SLAY) motifs, in an animal model of transient focal ischemia and demonstrated that its anti-inflammatory, pro-angiogenic, and phagocytosis inducing functions are responsible for the neuroprotective effects. In the present study, we truncated OPNpt20 to 13 or 7 amino acid peptides containing RGD (R) and/or SLAY (S) motifs (OPNpt13RS, OPNpt7R, OPNpt7RS, and OPNpt7S), and their neuroprotective efficacy was examined in a rat middle cerebral artery occlusion (MCAO) model. Intranasal administration of all four peptides significantly reduced infarct volume; OPNpt7R (VPNGRGD), the 7-amino-acid peptide containing an RGD motif, was determined to be the most potent, with efficacy comparable to that of OPNpt20. Additionally, sensory–motor functional deficits of OPNpt7R-administered MCAO animals were significantly improved, as indicated by the modified neurological severity scores and rotarod test. Notably, the expression of M1 markers was suppressed, whereas that of M2 markers (Arginase 1, CD206, and VEGF) was significantly enhanced in OPNpt7R-treated primary microglia cultures. Inflammation resolution by OPNpt7R was further confirmed in MCAO animals, in which upregulation of anti-inflammatory cytokines (Arg1, IL-10, IL-4, and CD36) and enhanced efferocytosis were detected. Moreover, studies using three mutant peptides (OPNpt7R-RAA or OPNpt7R-RAD, where RGD was replaced with RAA or RAD, respectively, and OPNpt7R-sc containing scrambled sequences) revealed that the RGD motif plays a vital role in conferring neuroprotection. In conclusion, the RGD-containing OPN heptamer OPNpt7R exhibits neuroprotective effects in the post-ischemic brain by suppressing M1 markers and augmenting M2 polarization of microglia and the RGD motif plays a critical role in these activities.

2021 ◽  
pp. 096452842110575
Author(s):  
Jing Zou ◽  
Guo-fu Huang ◽  
Qian Xia ◽  
Xing Li ◽  
Jing Shi ◽  
...  

Background: Neuroinflammation is the leading cause of neurological sequelae in ischemic stroke. Recently, we reported that the anti-inflammatory mediator annexin A1 (ANXA1) favored microglial M2 polarization in brain injury. The purpose of this study was to investigate electroacupuncture (EA) treatment and its potentially ANXA1-mediated anti-inflammatory effects in the middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model of stroke. Methods: Treatment with EA consisted of dense-sparse frequencies (alternating 4 Hz sparse waves for 1.5 s and 16 Hz dense waves for 1.5 s) at CV24 and GV26. Intracerebroventricular (ICV) injection of Boc-2 (5 µM) or short hairpin RNA (sh)ANXA1 (2 µL) 3 days before EA was performed to block the effects of ANXA1. Results: EA pretreatment enhanced expression of ANXA1 and its receptor, formyl peptide receptor (FPR), when compared to MCAO/R alone. EA treatment also rescued MCAO/R-induced deficits in neurological performance, and learning and memory, and reduced infarct volume. Double immunofluorescent labeling showed that EA prevented MCAO/R-induced changes in microglial activation and morphology. EA also reduced the release of pro-inflammatory cytokines, such as interleukin (IL)-1β, inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α, while increasing the release of anti-inflammatory cytokines, such as arginase-1 (Arg-1) and brain-derived neurotrophic factor (BDNF). All EA-induced effects were either partially or completely prevented by prior administration of FPR antagonist Boc-2 or shANXA1. Conclusion: The current study provides strong evidence that EA treatment has protective effects against ischemic stroke in the MCAO/R mouse model and that the mechanism likely involves the promotion of M2 polarization in microglia via ANXA1.


Stroke ◽  
2020 ◽  
Vol 51 (10) ◽  
pp. 3138-3141
Author(s):  
Bharath Chelluboina ◽  
Taehee Kim ◽  
Suresh L. Mehta ◽  
Joo-Yong Kim ◽  
Saivenkateshkomal Bathula ◽  
...  

Background and Purpose: Increased expression of α-Syn (α-Synuclein) is known to mediate secondary brain damage after stroke. We presently studied if α-Syn knockdown can protect ischemic brain irrespective of sex and age. Methods: Adult and aged male and female mice were subjected to transient middle cerebral artery occlusion. α-Syn small interfering RNA (siRNA) was administered intravenous at 30 minutes or 3 hour reperfusion. Poststroke motor deficits were evaluated between day 1 and 7 and infarct volume was measured at day 7 of reperfusion. Results: α-Syn knockdown significantly decreased poststroke brain damage and improved poststroke motor function recovery in adult and aged mice of both sexes. However, the window of therapeutic opportunity for α-Syn siRNA is very limited. Conclusions: α-Syn plays a critical role in ischemic brain damage and preventing α-Syn protein expression early after stroke minimizes poststroke brain damage leading to better functional outcomes irrespective of age and sex.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xubin Bao ◽  
Cai Chen ◽  
Liyong Yuan

Triptolide (T10) is a common anti-inflammatory and analgesic drug. However, the activation of microglia and elimination of the corresponding inflammatory response are new targets for the treatment of neuropathic pain. Chemokine CCL (CCL2) is a key mediator for activating microglia. In this study, the effects of triptolide on the activation and polarization of microglia cells and CCL2 and its corresponding receptor, chemokine receptor 2 (CCR2), were mainly discussed. Microglia were stimulated with 1 μg/mL lipopolysaccharide (LPS) and pretreated with 10, 20, and 40 nM T10 and CCR2 antagonist (RS102895), respectively. The quantitative polymerase chain reaction (QPCR) and western blot results showed that T10 could obviously inhibit the upregulation of CCL2 and CCR2 induced by LPS stimulation in microglia cells, inhibit the fluorescence intensity of glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) antibody immunostaining in cells, and upregulate the fluorescence intensity of arginase 1 antibody in cells. The expression of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) was inhibited in a dose-dependent manner. RS102895 can significantly reverse the activation and M2 polarization of microglia pretreated with 40 nM T10 and weaken the anti-inflammatory effect of T10. The addition of CCL2 did not extremely affect the function of RS102895. T10 may inhibit microglia activation and M1 polarization by inhibiting the expression of CCL2 and CCR2, promoting M2 polarization, reducing the level of inflammatory factors in cells, and exerting its analgesic effect, which is worthy of clinical promotion as a drug for neuropathic pain.


2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Weinan Yang ◽  
Lincheng Zhang ◽  
Simiao Chen ◽  
Qigu Yao ◽  
Haihong Chen ◽  
...  

Stroke is the leading cause of death in the elderly. Traditional Chinese medicine provides an exciting strategy for treating stroke. Previous reports indicated that Longshengzhi capsules (LSZ), a modified Chinese formula, reduced formed thrombi and oxidative stress and were promising in the clinical treatment of ischemic stroke. However, the specific therapeutic effect and mechanism of LSZ are still ambiguous. This study aimed to define the effects of LSZ on proinflammatory mediators and neuroprotective effects on middle cerebral artery occlusion and refusion (MCAO/R) rats. Rats were treated with different doses of LSZ (0.54, 1.62, and 4.32 g/(kg·d)) in a week after model building. LSZ could improve the survival rate, ischemic stroke outcome, and infarct volume. In addition, significant decrease was observed in reactive oxygen species (ROS) levels and inflammatory factor levels in LSZ-treated groups, concomitant with increase in activities of superoxide dismutase (SOD), neurosynaptic remodeling, and decrease in brain edema. It is proposed that LSZ has anti-inflammatory and neuroprotective effects resulting in downregulating matrix metalloproteinase 2/9 (MMP-2/9) and vascular endothelial growth factor (VEGF) and nuclear factor kappa-B (NF-κB) and upregulating microtubule-associated protein-2 (Map-2) and growth-associated protein-43 (GAP-43) via p38 MAPK and HIF-1α signaling pathways in MCAO/R rats. This study provides potential evidences that p38 MAPK and HIF-1α/VEGF signaling pathways play significant roles in the anti-inflammatory and neuroprotective effects of LSZ.


2020 ◽  
Author(s):  
Lvkeng Luo ◽  
Shuling Wu ◽  
Ruiqi Chen ◽  
Hongyu Rao ◽  
Wei Peng ◽  
...  

Abstract Background: Naoshuantong capsule (NSTC) is an oral Chinese medicine formula composed of Typhae Pollen, Radix Paeoniae Rubra Curcumae Radix Gastrodiae Rhizoma and Radix Rhapontici. It has been widely used at the acute and recovery stage of ischemic stroke since 2001. Comparing with its wide clinical application, there are only few studies emphasize on investigating its pharmacological effects. Methods:To more generally elucidate the underlying mechanisms in this study, we identified active ingredients in NSTC by a network pharmacology approach based on transcriptomics analysis and pharmacological experiments. Modified neurological severity scores and morphometric analysis using Nissl staining were employed to evaluate the neuroprotective effects of NSTC on ischemia stroke in mice. Results: The results showed that NSTC had preventive and protective effects on ischemia stroke, featuring repair of brain tissue during the sub-acute stage of stroke. This may attribute to the underlying mechanisms including anti-inflammatory, antioxidant, and anti-apoptotic activities, as well as an attenuation of excitatory amino acids (EAAs) toxicity of the active ingredients, especially the most active apigenin, from NSTC. Specifically, naringenin, calycosin, gastrodin, caffeic acid, paeoniflorin, and β -elemene seem to be also pharmacological active substances responsible for the anti-inflammatory effects. Meanwhile, 13-hydroxygemone, gastrodin, and p-hydroxybenzyl alcohol contributed to the attenuation of EAAs toxicity Furthermore, apigenin, naringenin, calycosin, gastrodin, and β-elemene accelerated the repair of brain ischemic tissue by up-regulating the expression of TGF-β1 levels.Conclusions: The present study identifies the active ingredients of NSTC and illustrates the underlying mechanism using a combination of network pharmacology, transcriptomics analysis, and pharmacological experiments.


2018 ◽  
Vol 27 (12) ◽  
pp. 1744-1752 ◽  
Author(s):  
Poornima Venkat ◽  
Tao Yan ◽  
Michael Chopp ◽  
Alex Zacharek ◽  
Ruizhuo Ning ◽  
...  

Angiopoietin-1 (Ang1) mediates vascular maturation and immune response. Diabetes decreases Ang1 expression and disrupts Ang1/Tie2 signaling activity. Vasculotide is an Ang1 mimetic peptide, and has anti-inflammatory effects. In this study, we test the hypothesis that vasculotide treatment induces neuroprotection and decreases inflammation after stroke in type 1 diabetic (T1DM) rats. T1DM rats were subjected to embolic middle cerebral artery occlusion (MCAo) and treated with: 1) phosphate buffered saline (PBS); 2) vasculotide (3µg/kg, i.p. injection) administered half an hour prior to MCAo and at 8 and 24 hours after MCAo. Rats were sacrificed at 48 h after MCAo. Neurological function, infarct volume, hemorrhage, blood brain barrier (BBB) permeability and neuroinflammation were measured. Vasculotide treatment of T1DM-MCAo rats significantly improves functional outcome, decreases infarct volume and BBB permeability, but does not decrease brain hemorrhagic transformation compared with PBS-treated T1DM-MCAo rats. In the ischemic brain, Vasculotide treatment significantly decreases apoptosis, number of cleaved-caspase-3 positive cells, the expression of monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor (TNF-α). Western blot analysis shows that vasculotide significantly decreases expression of receptor for advanced glycation end products (RAGE), MCP-1 and TNF-α in the ischemic brain compared with T1DM-MCAo rats. Vasculotide treatment in cultured primary cortical neurons (PCN) significantly decreases TLR4 expression compared with control. Decreased neuroinflammation and reduced BBB leakage may contribute, at least in part, to vasculotide-induced neuroprotective effects after stroke in T1DM rats.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Changjun Yang ◽  
Brian D Sanz ◽  
Kelly M DeMars ◽  
Andrew A Butler ◽  
Eduardo Candelario-Jalil

Adropin is an endogenous peptide highly expressed in the brain and is encoded by the energy homeostasis-associated gene, Enho . We recently found that treatment with synthetic adropin peptide reduces infarct volume in ischemic stroke. This protection by exogenous adropin is associated with a significant increase in endothelial nitric oxide synthase (eNOS) phosphorylation (Ser 1176 ) and reduction of blood-brain barrier (BBB) permeability. However, it is not known whether endogenous adropin modulates ischemic brain damage. We hypothesize that lack of brain adropin increases stroke damage by exacerbating neurovascular dysfunction, while overexpression of this peptide decreases ischemic brain injury. We measured infarct size and BBB damage in male and female adropin overexpressing transgenics (AdrTg), adropin knockout ( Enho -/- ), and corresponding wild-type (WT) control mice subjected to permanent middle cerebral artery occlusion (pMCAO). At 48h after stroke, infarct volume was significantly smaller in AdrTg mice of both sexes compared to WT controls, while stroke resulted in a much larger infarction in both male and female Enho -/- compared to Enho +/+ mice. Brain levels of IgG and albumin, two sensitive markers of BBB disruption, were significantly reduced in AdrTg mice compared to the WT group, while the levels of these two plasma proteins in the ischemic brain of Enho -/- mice were dramatically increased compared to Enho +/+ animals after stroke. Latex vessel casting showed no differences in cerebrovascular anatomy or the diameter of the main brain arteries between Enho -/- , AdrTg and their respective WT controls. In AdrTg mice, we found a positive correlation between brain adropin levels and eNOS phosphorylation. These data suggest that increased eNOS phosphorylation by adropin is a potential mechanism underlying its protective effects in stroke. Consistent with this hypothesis, the protective effects of adropin were completely abolished in eNOS knockout (eNOS -/- ) mice subjected to pMCAO. Taken together, our findings show for the first time that endogenous adropin is a neuroprotective peptide in ischemic stroke. Understanding adropin signaling and function could offer a novel therapeutic strategy for the treatment of ischemic brain damage.


2009 ◽  
Vol 37 (03) ◽  
pp. 547-555 ◽  
Author(s):  
Jae-Hyeon Cho ◽  
Jin-Hee Sung ◽  
Eun-Hae Cho ◽  
Chung-Kil Won ◽  
Hyo-Jong Lee ◽  
...  

EGb 761 is a standardized extract of Gingko biloba that exerts protective effects against ischemic brain injury. This study investigated whether EGb 761 modulates the neuroprotective effects through Akt and its downstream targets, Bad and FKHR. Adult male rats were treated with EGb 761 (100 mg/kg) or vehicle prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 hours after MCAO and infarct volumes were analyzed. EGb 761 significantly reduced infarct volume. Potential activation was mearsured by phosphorylation of Akt at Ser473, Bad at Ser136, and FKHR at Ser256 using Western blot analysis. EGb 761 prevented the injury-induced decrease of pAkt and its down stream targets, pBad and pFKHR. Furthermore, EGb 761 prevented the injury-induced increase of cleaved caspase-3 levels. In conclusion, this study suggests that EGb 761 prevents cell death due to brain injury and that EGb 761 protection is affected by preventing the injury-induce decrease of Akt phosphorylation.


2020 ◽  
Author(s):  
Lvkeng Luo ◽  
Shuling Wu ◽  
Ruiqi Chen ◽  
Hongyu Rao ◽  
Wei Peng ◽  
...  

Abstract Background: Naoshuantong capsule (NSTC) is an oral Chinese medicine formula composed of Typhae Pollen, Radix Paeoniae Rubra, Curcumae Radix, Gastrodiae Rhizoma and Radix Rhapontici. It has been widely used at the acute and recovery stage of ischemic stroke since 2001. Comparing with its wide clinical application, there are only few studies emphasize on investigating its pharmacological effects.Methods:To more generally elucidate the underlying mechanisms in this study, we identified active ingredients in NSTC by a network pharmacology approach based on transcriptomics analysis and pharmacological experiments. Modified neurological severity scores and morphometric analysis using Nissl staining were employed to evaluate the neuroprotective effects of NSTC on ischemia stroke in mice.Results: The results showed that NSTC had preventive and protective effects on ischemia stroke, featuring repair of brain tissue during the sub-acute stage of stroke. This may attribute to the underlying mechanisms including anti-inflammatory, antioxidant, and anti-apoptotic activities, as well as an attenuation of excitatory amino acids (EAAs) toxicity of the active ingredients, especially the most active apigenin, from NSTC. Specifically, naringenin, calycosin, gastrodin, caffeic acid, paeoniflorin, and β -elemene seem to be also pharmacological active substances responsible for the anti-inflammatory effects. Meanwhile, 13-hydroxygemone, gastrodin, and p-hydroxybenzyl alcohol contributed to the attenuation of EAAs toxicity Furthermore, apigenin, naringenin, calycosin, gastrodin, and β-elemene accelerated the repair of brain ischemic tissue by up-regulating the expression of TGF-β1 levels.Conclusions: The present study identifies the active ingredients of NSTC and illustrates the underlying mechanism using a combination of network pharmacology, transcriptomics analysis, and pharmacological experiments.


2020 ◽  
Author(s):  
Lvkeng Luo ◽  
Shuling Wu ◽  
Ruiqi Chen ◽  
Hongyu Rao ◽  
Wei Peng ◽  
...  

Abstract Background Naoshuantong capsule (NSTC) is an oral Chinese medicine formula composed of Typhae Pollen (TP), Radix Paeoniae Rubra (PR), Curcumae Radix (CR), Gastrodiae Rhizoma (GR) and Radix Rhapontici (RR). It has been widely used at the acute and recovery stage of ischemic stroke since 2001. Comparing with its wide clinical application, there are only few studies emphasize on investigating its pharmacological effects. Methods To more generally elucidate the underlying mechanisms in this study, we identified active ingredients in NSTC by a network pharmacology approach based on transcriptomics analysis and pharmacological experiments. Modified neurological severity scores (mNSS) and morphometric analysis using Nissl staining were employed to evaluate the neuroprotective effects of NSTC on ischemia stroke in mice. Results The results showed that NSTC had preventive and protective effects on ischemia stroke, featuring repair of brain tissue during the sub-acute stage of stroke. This may attribute to the underlying mechanisms including anti-inflammatory, antioxidant, and anti-apoptotic activities, as well as an attenuation of excitatory amino acids (EAAs) toxicity of the active ingredients, especially the most active apigenin, from NSTC. Specifically, naringenin, calycosin, gastrodin, caffeic acid, paeoniflorin, and β -elemene seem to be also pharmacological active substances responsible for the anti-inflammatory effects. Meanwhile, 13-hydroxygemone, gastrodin, and p-hydroxybenzyl alcohol contributed to the attenuation of EAAs toxicity Furthermore, apigenin, naringenin, calycosin, gastrodin, and β-elemene accelerated the repair of brain ischemic tissue by up-regulating the expression of TGF-β1 levels. Conclusions The present study identifies the active ingredients of NSTC and illustrates the underlying mechanism using a combination of network pharmacology, transcriptomics analysis, and pharmacological experiments.


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