Angioedema and Hemorrhage After 4.5-Hour tPA (Tissue-Type Plasminogen Activator) Thrombolysis Ameliorated by T541 via Restoring Brain Microvascular Integrity

The relationship between ischemic penumbra progression and the oxygen content of cortex microcirculation in acute ischemic stroke

The precise oxygen content thresholds of ischemic deep parenchymal (OCIDP) and that in cortical microcirculation (OCCM), which leads to ischemic penumbra converting into the infarcted core, remain uncertain. This study employed an invasive fiber-optic oxygen meter and a newly developed oxygen-responsive probe called RuA3-Cy5-rtPA (RC-rtPA) based on recombinant tissue-type plasminogen activator (rtPA) to examine the oxygen content thresholds. A mouse model of middle cerebral artery occlusion was generated and animals were randomly divided into a sham, 24-h reperfusion after 3-h ischemia (IR 3-h), and IR 6-h groups, all of which were sacrificed following reperfusion. Stroke severity was evaluated based on the infarction area, neurological symptoms, microcirculation perfusion, and microemboli in microcirculation. OCIDP was characterized based on its extent and distribution, whereas OCCM was measured using RC-rtPA. During ischemia, stroke severity escalation manifested as increasing infarction area, severe neurologic symptoms, and poorer microcirculation perfusion with more microthrombi depositions. OCIDP presented rapid decline following artery occlusion along with a gradual increase in the hypoxic area. Within 3 ​h following ischemia induction, the ischemic tissue that experienced hypoxia could be rescued, and this reversibility would disappear after 6 ​h. Within 6 ​h, OCCM continued to decrease. A significant decrease in oxygen content in cortical venules and cortical parenchyma was observed. These findings assist in establishing the extent of the ischemic penumbra at the microcirculation level and offer a foundation for assessing the ischemic penumbra that could respond positively to reperfusion therapy beyond the typical time window.

Endothelial PDGF-D contributes to neurovascular protection after ischemic stroke by rescuing pericyte functions

Ischemic stroke induces neovascularization of the injured tissue as an attempt to promote structural repair and neurological recovery. Angiogenesis is regulated by pericytes that potently react to ischemic stroke stressors, ranging from death to dysfunction. Platelet-derived growth factor (PDGF) receptor (PDGFR)β controls pericyte survival, migration, and interaction with brain endothelial cells. PDGF-D a specific ligand of PDGFRβ is expressed in the brain, yet its regulation and role in ischemic stroke pathobiology remains unexplored. Using experimental ischemic stroke mouse model, we found that PDGF-D is transiently induced in brain endothelial cells at the injury site in the subacute phase. To investigate the biological significance of PDGF-D post-ischemic stroke regulation, its subacute expression was either downregulated using siRNA or upregulated using an active recombinant form. Attenuation of PDGF-D subacute induction exacerbates neuronal loss, impairs microvascular density, alters vascular permeability, and increases microvascular stalling. Increasing PDGF-D subacute bioavailability rescues neuronal survival and improves neurological recovery. PDGF-D subacute enhanced bioavailability promotes stable neovascularization of the injured tissue and improves brain perfusion. Notably, PDGF-D enhanced bioavailability improves pericyte association with brain endothelial cells. Cell-based assays using human brain pericyte and brain endothelial cells exposed to ischemia-like conditions were applied to investigate the underlying mechanisms. PDGF-D stimulation attenuates pericyte loss and fibrotic transition, while increasing the secretion of pro-angiogenic and vascular protective factors. Moreover, PDGF-D stimulates pericyte migration required for optimal endothelial coverage and promotes angiogenesis. Our study unravels new insights into PDGF-D contribution to neurovascular protection after ischemic stroke by rescuing the functions of pericytes.

Targeting blood-brain barrier for sepsis-associated encephalopathy: Regulation of immune cells and ncRNAs

Sepsis causes significant morbidity and mortality worldwide, most surviving patients show acute or chronic mental disorders, which are known as sepsis-associated encephalopathy (SAE). SAE involves many pathological processes, including the blood-brain barrier (BBB) damage. The BBB is located at the interface between the central nervous system and the surrounding environment, which protects the central nervous system (CNS) from the invasion of exogenous molecules, harmful substances or microorganisms in the blood. Recently, a growing number of studies have indicated that the BBB destruction was involved in SAE and played an important role in SAE-induced brain injury. In the present review, we firstly reveal the pathological processes of SAE such as the neurotransmitter disorders, oxidative stress, immune dysfunction and BBB destruction. Moreover, we introduce the structure of BBB, and describe the immune cells including microglia and astrocytes that participate in the BBB destruction after SAE. Furthermore, in view of the current research on non-coding RNAs (ncRNAs), we explain the regulatory mechanism of ncRNAs including long noncoding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) on BBB in the processes of SAE. Finally, we propose some challenges and perspectives of regulating BBB functions in SAE. Hence, on the basis of these effects, both immune cells and ncRNAs may be developed as therapeutic targets to protect BBB for SAE patients.

GPR55 Inactivation Diminishes Splenic Responses and Improves Neurological Outcomes in the Mouse Ischemia/Reperfusion Stroke Model

Although strokes are frequent and severe, treatment options are scarce. Plasminogen activators, the only FDA-approved agents for clot treatment (tissue plasminogen activators (tPAs)), are used in a limited patient group. Moreover, there are few approaches for handling the brain's inflammatory reactions to a stroke. The orphan G protein-coupled receptor 55 (GPR55)'s connection to inflammatory processes has been recently reported; however, its role in stroke remains to be discovered. Post-stroke neuroinflammation involves the central nervous system (CNS)'s resident microglia activation and the infiltration of leukocytes from circulation into the brain. Additionally, splenic responses have been shown to be detrimental to stroke recovery. While lymphocytes enter the brain in small numbers, they regularly emerge as a very influential leukocyte subset that causes secondary inflammatory cerebral damage. However, an understanding of how this limited lymphocyte presence profoundly impacts stroke outcomes remains largely unclear. In this study, a mouse model for transient middle cerebral artery occlusion (tMCAO) was used to mimic ischemia followed by a reperfusion (IS/R) stroke. GPR55 inactivation, with a potent GPR55-specific antagonist, ML-193, starting 6 h after tMCAO or the absence of the GPR55 in mice (GPR55 knock out (GPR55ko)) resulted in a reduced infarction volume, improved neurological outcomes, and decreased splenic responses. The inhibition of GPR55 with ML-193 diminished CD4+T-cell spleen egress and attenuated CD4+T-cell brain infiltration. Additionally, ML-193 treatment resulted in an augmented number of regulatory T cells (Tregs) in the brain post-tMCAO. Our report offers documentation and the functional evaluation of GPR55 in the brain-spleen axis and lays the foundation for refining therapeutics for patients after ischemic attacks.

YangXueQingNaoWan attenuated blood brain barrier disruption after thrombolysis with tissue plasminogen activator in ischemia stroke

ETHNOPHARMACOLOGICAL RELEVANT

YangXueQingNaoWan (YXQNW), a compound Chinese medicine, has been widely used for dizziness, irritability, insomnia, and dreaminess caused by blood deficiency and liver hyperactivity in China. However, whether YXQNW can inhibit cerebral microvascular exudation and cerebral hemorrhage (CH) caused by blood brain barrier (BBB) damage after tissue plasminogen activator (tPA) still unknown.

AIM OF THE RESEARCH

To observe the effect of YXQNW on cerebral microvascular exudation and CH after tPA and investigate its mechanism in protecting BBB.

MATERIALS AND METHODS

Male C57BL/6 N mice suffered from ischemia stroke by mechanical detachment of carotid artery thrombi with the stimulation of ferric chloride. Then mice were treated with tPA (10 mg/kg) and/or YXQNW (0.72 g/kg) at 4.5 h. Cerebral blood flow (CBF), infarct size, survival rate, neurological scores, gait analysis, Evans blue extravasation, cerebral water content, fluorescein isothiocyanate-labeled albumin leakage, hemorrhage, junction and basement membrane proteins expression, leukocyte adhesion and matrix metalloproteinases (MMPs) expression were evaluated 24 h after tPA. Proteomics was used to identify target proteins.

RESULTS

YXQNW inhibited cerebral infarction, neurobehavioral deficits, decreased survival, Evans blue leakage, albumin leakage, cerebral water content and CH after tPA thrombolysis; improved CBF, low-expression and degradation of junction proteins, basement membrane proteins, Arhgap21 and its downstream α-catenin and β-catenin proteins expression; and suppressed the increase of adherent leukocytes and the release of MMP-9 derived from macrophage.

CONCLUSION

YXQNW relieved BBB damage and attenuated cerebral microvascular exudation and CH after tPA thrombolysis. The effect of YXQNW on cerebral microvascular exudation was associated with the inhibition of the low-expression of junction proteins, especially AJs mediated by Rho GTPase-activating protein 21 (Arhgap21), while the effect on CH was associated with the inhibition of leukocyte adhesion, the release of MMP-9 derived from macrophage, and low-expression and degradation of collagen IV and laminin in the vascular basement membrane.

Biomimetic oxygen-boosted hybrid membrane nanovesicles as the treatment strategy for ischemic stroke with the concept of the neurovascular unit

The pathogenesis of ischemic cerebrovascular disease has revealed that ischemic stroke often leads to deprivation of oxygen, blood-brain barrier (BBB) damage and enhanced inflammatory activation, eventually causing severe brain tissue damage. Herein, we prepared hybrid membrane nanovesicles (YC-1@[RBC-PL] NVs) composed of red blood cell (RBC) membrane and platelet (PL) membrane encapsulating hypoxia inducible factor-1α (HIF-1α) inhibitor YC-1 for contributing to the protection of the neurovascular unit (NVU) in ischemic stroke. YC-1@[RBC-PL] NVs targeted the ischemic brain by the thrombus targeting properties of PL membrane and relieved the hypoxia inside ischemic brain in the presence of YC-1 and catalase in YC-1@[RBC-PL] NVs. Finally, YC-1@[RBC-PL] NVs attenuated ischemic injury to NVU by reducing infarct volume, preserving BBB integrity, and blocking activation of astrocyte and microglia in a middle cerebral artery occlusion/reperfusion (MCAO/R) model.

Mitochondrial oxidative stress in brain microvascular endothelial cells: Triggering blood-brain barrier disruption

Blood-brain barrier disruption plays an important role in central nervous system diseases. This review provides information on the role of mitochondrial oxidative stress in brain microvascular endothelial cells in cellular dysfunction, the disruption of intercellular junctions, transporter dysfunction, abnormal angiogenesis, neurovascular decoupling, and the involvement and aggravation of vascular inflammation and illustrates related molecular mechanisms. In addition, recent drug and nondrug therapies targeting cerebral vascular endothelial cell mitochondria to repair the blood-brain barrier are discussed. This review shows that mitochondrial oxidative stress disorder in brain microvascular endothelial cells plays a key role in the occurrence and development of blood-brain barrier damage and may be critical in various pathological mechanisms of blood-brain barrier damage. These new findings suggest a potential new strategy for the treatment of central nervous system diseases through mitochondrial modulation of cerebral vascular endothelial cells.

Ferrostatin-1 alleviates cerebral ischemia/reperfusion injury through activation of the AKT/GSK3β signaling pathway

Ischemic stroke is the major cause of disability and death worldwide, but post-stroke neuronal death and related mechanisms remain unclear. Ferroptosis, a newly identified type of regulated cell death, has been shown to be associated with neurological disorders, yet the exact relationship between ferroptosis and ischemic stroke has not been elucidated. The purpose of this study is to investigate the effects of ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) on neuronal injury after cerebral ischemia/reperfusion (I/R) and the underlying mechanism. In this study, we demonstrated that ferroptosis does occur in the stroke model. We found that Fer-1 reduced the levels of iron and malondialdehyde, and increased the content of glutathione and the expression of solute carrier family 7 member 11 and glutathione peroxidase 4 in cerebral I/R models. Additionally, Fer-1 significantly reduced the infarct volume and improved neurobehavioral outcomes. Moreover, we found that Fer-1 increased the levels of phosphorylated AKT and GSK3β following cerebral I/R. To further investigate the functional role of the AKT in the neuroprotective effects of Fer-1, MCAO models and oxygen-glucose deprivation-induced HT22 cells were pretreated with the AKT inhibitor MK-2206 before treatment with Fer-1 and the protective effects of Fer-1 were reversed. In conclusion, Fer-1 has protective effects on cerebral I/R injury by activating the AKT/GSK3β pathway, indicating that ferroptosis may become a novel target in the treatment of ischemic stroke.

A modified mouse model of haemorrhagic transformation associated with tPA administration after thromboembolic stroke

Objective

To establish a new mouse model of haemorrhagic transformation associated with delayed tissue-type plasminogen activator (tPA) treatment to provide a novel tool to study therapeutic strategies for haemorrhagic transformation.

Methods

Male C57BL/6 mice were subjected to carotid artery thrombosis stimulated with ferric chloride. The thrombus was then mechanically detached to induce migration toward the intracranial circulation. To induce haemorrhagic transformation, mice were intravenously injected with 10 mg/kg tPA 4.5 h after the onset of ischaemia and were sacrificed 24 h after tPA treatment.

Results

In this new model, administration of tPA 4.5 h after stroke exacerbated the risk of intracerebral haemorrhage. Thrombolysis with tPA also exacerbated cerebral infarction, brain oedema, blood-brain barrier breakdown, and neurological deficits. However, cerebral blood flow was not significantly affected.

Conclusion

The present model is reproducible, easy to perform, and mimics the clinical situation of haemorrhagic transformation after tPA treatment in humans. This modified model can be used as a new tool to test experimental drugs for haemorrhagic transformation associated with delayed tPA administration after an ischaemic stroke.

The role of traditional herbal medicine for ischemic stroke: from bench to clinic-A critical review

BACKGROUND

Ischemic stroke (IS) is a leading cause of death and severe long-term disability worldwide. Over the past few decades, considerable progress has been made in anti-ischemic therapies. However, IS remains a tremendous challenge, with favourable clinical outcomes being generally difficult to achieve from candidate drugs in preclinical phase testing. Traditional herbal medicine (THM) has been used to treat stroke for over 2,000 years in China. In modern times, THM as an alternative and complementary therapy have been prescribed in other Asian countries and have gained increasing attention for their therapeutic effects. These millennia of clinical experience allow THM to be a promising avenue for improving clinical efficacy and accelerating drug discovery.

PURPOSE

To summarise the clinical evidence and potential mechanisms of THMs in IS.

METHODS

A comprehensive literature search was conducted in seven electronic databases, including PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the Chinese National Knowledge Infrastructure, the VIP Information Database, the Chinese Biomedical Literature Database, and the Wanfang Database, from inception to 17 June 2022 to examine the efficacy and safety of THM for IS, and to investigate experimental studies regarding potential mechanisms.

RESULTS

THM is widely prescribed for IS alone or as adjuvant therapy. In clinical trials, THM is generally administered within 72 h of stroke onset and are continuously prescribed for over 3 months. Compared with Western medicine (WM), THM combined with routine WM can significantly improve neurological function defect scores, promote clinical total effective rate, and accelerate the recovery time of stroke with fewer adverse effects (AEs). These effects can be attributed to multiple mechanisms, mainly anti-inflammation, antioxidative stress, anti-apoptosis, brain blood barrier (BBB) modulation, inhibition of platelet activation and thrombus formation, and promotion of neurogenesis and angiogenesis.

CONCLUSIONS

THM may be a promising candidate for IS management to guide clinical applications and as a reference for drug development.

Neuroprotective, Anti-inflammatory Effect of Furanochrome, Visnagin Against Middle Cerebral Ischemia-Induced Rat Model

In recent years, the medical field had significantly progressed to a greater extent which was evidenced with increased life expectancy and decreased mortality rate. Due to the growth of medical field, numerous communicable diseases are prevented and eradicated, whereas the non-communicable disease incidence has been increased globally. One such non-communicable disease which threatens the global population is stroke. Stroke tends to be the second leading cause of death and disability in older population. In lower- and middle-income countries, increased incidence rate of stroke was also evidenced in younger population which is alarming. Lifestyle changes, poor physical activity, stress, consumption of alcohol, oral contraception, and smoking tend to be the causative agents of stroke. Since thrombus formation is the major pathology of stroke, drugs were targeted to thrombolysis. Currently thrombolytic, antiplatelet, and anticoagulant therapies were given for the stroke patients. But the recovery rate of stroke patients with available drugs is very slow. Hence, it is a need of today to discover a drug with increased recovery rate and decreased or nil side effects. Phytochemicals are the best options to treat such non-communicable chronic diseases. Visnagin is one such compound which is used to regulate blood pressure, treat kidney stones, tumors of bile duct, renal colic, and whooping cough. It possesses anti-inflammatory, neuroprotective, and cardioprotective properties; it was also proven to treat epileptic seizures. In this study, the anti-ischemic effect of a furanochrome visnagin was assessed in in vivo rat model. Middle cerebral ischemic/reperfusion was induced in healthy male Sprague Dawley rats and treated with different concentrations of visnagin. The neuroprotective effect of visnagin against cerebral ischemia-induced rats was assessed by analyzing the neurological score, brain edema, infract volume, and Evans blue leakage. The anti-inflammatory property of visnagin was assessed by quantifying proinflammatory cytokines in serum and brain tissues of cerebral ischemia-induced rats. Prostaglandin E-2, COX-2, and NFκ-β were estimated to assess the anti-ischemic effect of visnagin. Histopathological analysis with H&E staining was performed to confirm the neuroprotective effect of visnagin against cerebral ischemia. Our results authentically confirm that visnagin has prevented the inflammation in brain region of cerebral ischemia-induced rats. The neurological scoring and the quantification of PGE-2, COX-2, and NFκ-β prove the anti-ischemic effect of visnagin. Furthermore, the histopathological analysis of hippocampal region provides evidence to the neuroprotective effect of visnagin against cerebral ischemia. Overall, our study confirms visnagin as a potent alternative drug to treat stroke.

Role of Rph3A in brain injury induced by experimental cerebral ischemia-reperfusion model in rats

Aim

The aim was to study the role of Rph3A in neuronal injury induced by cerebral ischemia‐reperfusion.

Methods

The protein and mRNA levels of Rph3A in penumbra were detected by Western blot. The localization of Rph3A in different cell types in penumbra was detected by immunofluorescence. Apoptosis in the brain was detected by TUNEL staining. We tested neurobehavioral evaluation using rotarod test, adhesive‐removal test, and Morris Water maze test. We examined the expression and localization of Rph3A in cultured neurons and astrocytes in vitro by Western blot and ELISA, respectively.

Results

The mRNA and protein levels of Rph3A had significantly increased in brain penumbra of the rat MCAO/R model. Rph3A was mainly distributed in neurons and astrocytes and was significantly increased by MCAO/R. We downregulated Rph3A and found that it further worsened the cerebral infarct, neuronal death and behavioral, cognitive, and memory impairments in rats after MCAO/R. We also found that ischemia‐reperfusion upregulated the in vitro protein level and secretion of Rph3A in astrocytes but led to a decrease in the protein level of Rph3A in neurons.

Conclusion

The increase in Rph3A in the brain penumbra may be an endogenous protective mechanism against ischemia‐reperfusion injury, which is mainly dominated by astrocytes.

Efficacy of Chinese herbal medicine for tPA thrombolysis in experimental stroke: A systematic review and meta-analysis

BACKGROUND

Tissue-type plasminogen activator (tPA) remains the sole FDA approved thrombolytic drug for ischemic stroke. But delayed thrombolytic therapy with tPA may increase the risk of hemorrhagic transformation. Many Chinese herbal medicines have been used as tPA helpers to enhance the capacity of tPA and minimize the risk of hemorrhagic transformation. The efficacy of Chinese herbal medicines on tPA thrombolysis is not systematically analyzed.

METHODS

We searched the following three databases up to January 2022: Web of Science, PubMed, and Scopus. Studies that reported the efficacy and safety of Chinese herbal medicines on tPA thrombolysis in experimental stroke were included. The efficacy outcomes were neurological score and infarct volume, the safety outcomes were cerebral hemorrhage and blood brain barrier (BBB) damage. We used the checklist of CAMARADES to assess the quality of included studies. Standardized mean difference (SMD) with 95% confidence intervals were used to assess all the outcomes. Subgroup analyses were performed to explore the sources of heterogeneity. Trim and fill method and Egger's test were used to assess the potential publication bias. Sensitivity analyses were used to identify the stability of the results.

RESULTS

A total of nine studies including 11 Chinese herbal medicines fulfilled the inclusion criteria and were subsequently analyzed. The pooled data demonstrated that Chinese herbal medicines improved neurological score (2.23 SMD, 1.42-3.04), infarct volume (1.08 SMD, 0.62-1.54), attenuated cerebral hemorrhage (1.87 SMD, 1.34-2.4), and BBB dysfunction (1.9 SMD, 1.35-2.45) following tPA thrombolysis in experimental stroke. Subgroup analysis indicated that the route of drug delivery, dosage of tPA, and stroke model used may be factors inducing heterogeneity and influencing the efficacy.

CONCLUSION

Treatment with Chinese herbal medicines significantly improved neurological score and infarct volume, reduced cerebral hemorrhage and BBB damage after tPA thrombolysis. This study supports Chinese herbal medicine as an adjuvant therapy in reducing the side effects of tPA thrombolysis after acute ischemic stroke. The results should be interpreted with more caution since this article was based on animal studies.

QiShenYiQi Inhibits Tissue Plasminogen Activator-Induced Brain Edema and Hemorrhage after Ischemic Stroke in Mice

Background: Thrombolysis with tissue plasminogen activator (tPA) remains the only approved drug therapy for acute ischemic stroke. However, delayed tPA treatment is associated with an increased risk of brain hemorrhage. In this study, we assessed whether QiShenYiQi (QSYQ), a compound Chinese medicine, can attenuate tPA-induced brain edema and hemorrhage in an experimental stroke model. Methods: Male mice were subjected to ferric chloride-induced carotid artery thrombosis followed by mechanical detachment of thrombi. Then mice were treated with QSYQ at 2.5 h followed by administration of tPA (10 mg/kg) at 4.5 h. Hemorrhage, infarct size, neurological score, cerebral blood flow, Evans blue extravasation, FITC-labeled albumin leakage, tight and adherens junction proteins expression, basement membrane proteins expression, matrix metalloproteinases (MMPs) expression, leukocyte adhesion, and leukocyte infiltration were assessed 24 h after tPA administration. Results: Compared with tPA alone treatments, the combination therapy of QSYQ and tPA significantly reduced hemorrhage, infarction, brain edema, Evans blue extravasation, albumin leakage, leukocyte adhesion, MMP-9 expression, and leukocyte infiltration at 28.5 h after stroke. The combination also significantly improved the survival rate, cerebral blood flow, tight and adherens junction proteins (occludin, claudin-5, junctional adhesion molecule-1, zonula occludens-1, VE-cadherin, α-catenin, β-catenin) expression, and basement membrane proteins (collagen IV, laminin) expression. Addition of QSYQ protected the downregulated ATP 5D and upregulated p-Src and Caveolin-1 after tPA treatment. Conclusion: Our results show that QSYQ inhibits tPA-induced brain edema and hemorrhage by protecting the blood-brain barrier integrity, which was partly attributable to restoration of energy metabolism, protection of inflammation and Src/Caveolin signaling activation. The present study supports QSYQ as an effective adjunctive therapy to increase the safety of delayed tPA thrombolysis for ischemic stroke.

The natural (poly)phenols as modulators of microglia polarization via TLR4/NF-κB pathway exert anti-inflammatory activity in ischemic stroke

Increasing evidences suggest that inflammation plays a key role in the pathogenesis of stroke, a devastating disease second only to cardiac ischemia as a cause of death worldwide. Microglia are the first non-neuronal cells on the scene during the innate immune response to acute ischemic stroke. Microglia respond to acute brain injury by activating and developing classic M1-like (pro-inflammatory) or alternative M2-like (anti-inflammatory) phenotypes. M1 microglia produce pro-inflammatory cytokines to exacerbate neural death, astrocyte apoptosis, and blood brain barrier (BBB) disruption, while M2 microglia play the opposite role. NF-κB, a central regulator of the inflammatory response, was responsible for microglia M1 and M2 polarization. NF-κB p65 and p50 form a heterodimer to initiate a pro-inflammatory cytokine response, which enhances M1 activation and impair M2 response of microglia. TLR4, expressed on the surface of microglia, plays an important role in activating NF-κB, ultimately causing the M1 response of microglia. Therefore, modulation of microglial phenotypes via TLR4/NF-κB signaling pathway may be a promising therapeutic approach for ischemic stroke. Dietary (poly)phenols are present in various foods, which have shown promising protective effects on ischemic stroke. In vivo studies strongly suggest that many (poly)phenols have a pronounced impact on ischemic stroke, as demonstrated by lower neuroinflammation. Thus, this review focuses on the anti-inflammatory properties of dietary (poly)phenols and discusses their effects on the polarization of microglia through modulating TLR4/NF-κB signaling pathway in the ischemic stroke.

Mitochondrial Transplantation Attenuates Cerebral Ischemia-Reperfusion Injury: Possible Involvement of Mitochondrial Component Separation

Background

Mitochondrial dysfunctions play a pivotal role in cerebral ischemia-reperfusion (I/R) injury. Although mitochondrial transplantation has been recently explored for the treatment of cerebral I/R injury, the underlying mechanisms and fate of transplanted mitochondria are still poorly understood.

Methods

Mitochondrial morphology and function were assessed by fluorescent staining, electron microscopy, JC-1, PCR, mitochondrial stress testing, and metabolomics. Therapeutic effects of mitochondria were evaluated by cell viability, reactive oxygen species (ROS), and apoptosis levels in a cellular hypoxia-reoxygenation model. Rat middle cerebral artery occlusion model was applied to assess the mitochondrial therapy in vivo. Transcriptomics was performed to explore the underlying mechanisms. Mitochondrial fate tracking was implemented by a variety of fluorescent labeling methods.

Results

Neuro-2a (N2a) cell-derived mitochondria had higher mitochondrial membrane potential, more active oxidative respiration capacity, and less mitochondrial DNA copy number. Exogenous mitochondrial transplantation increased cellular viability in an oxygen-dependent manner, decreased ROS and apoptosis levels, improved neurobehavioral deficits, and reduced infarct size. Transcriptomic data showed that the differential gene enrichment pathways are associated with metabolism, especially lipid metabolism. Mitochondrial tracking indicated specific parts of the exogenous mitochondria fused with the mitochondria of the host cell, and others were incorporated into lysosomes. This process occurred at the beginning of internalization and its efficiency is related to intercellular connection.

Conclusions

Mitochondrial transplantation may attenuate cerebral I/R injury. The mechanism may be related to mitochondrial component separation, altering cellular metabolism, reducing ROS, and apoptosis in an oxygen-dependent manner. The way of isolated mitochondrial transfer into the cell may be related to intercellular connection.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

Proteomics and transcriptome reveal the key transcription factors mediating the protection of Panax notoginseng saponins (PNS) against cerebral ischemia/reperfusion injury

BACKGROUND AND PURPOSE

Transcription factors (TFs) play a critical role in the cerebral ischemia/reperfusion injury (IRI). Panax notoginseng saponins (PNS) are extensively used in the treatment of acute cerebral ischemia in China, but the mechanism of their effects, especially at the TF level, remains unclear. In this study, a combination of transcriptomics, proteomics and network pharmacology analysis was used to identify the key TFs involved in the protection of PNS against middle cerebral artery occlusion (MCAO)-induced IRI.

METHODS AND RESULTS

Sprague-Dawley rats which were subjected to 1.5 hours of MCAO-induced occlusionand then followed by reperfusion, were treated with PNS at a concentration of 36 mg/kg or 72 mg/kg daily for 7 days. PNS significantly decreased neurological deficient scores and infarction rate; prevented cerebral tissue damage; and reduced CASP3 activity, levels of TNF, IL1B and CCL2 after IRI. Through a combination of transcriptomics and proteomics, 9 critical TFs were identified, including Excision repair cross-complementing group 2 (ERCC2), Nuclear receptor subfamily 4 group A member 3 (NR4A3) and 7 other TFs. The targets of ERCC2 and NR4A3, such as Ubxn11, Ush2a, Numr2, Oxt, Ubxn11, Scrt2, Ttc34 and Lrrc23, were verified by using real-time PCR analysis. RNA-seq analyses indicated that PNS regulated nerve system development and inflammation, and the majority of the identified TFs were also involved in these processes. By using network pharmacology analysis, 73 chemical components in PNS were predicted to affect ERCC2, NR4A3 and 3 other identified TFs.

CONCLUSION

ERCC2, NR4A3 and 7 other TFs were of importance in the protection of PNS against IRI. This study promoted the understanding of protective mechanism of PNS against cerebral IRI and facilitated the identification of possible targets of PNS.

Serum of limb remote ischemic postconditioning inhibits fMLP-triggered activation and reactive oxygen species releasing of rat neutrophils

Objectives

The study explores the protective role of the peripheral serum of limb remote ischemic postconditioning (LRIP) in reducing the reactive oxygen species (ROS) levels and neutrophil activation, which are responsible for the deleterious reperfusion injury.

Methods

LRIP was induced in Sprague–Dawley rats by three cycles of 5 min occlusion /5 min reperfusion on the left hind limb. The blood samples were collected before LRIP or 0 and 1 h after LRIP (named Serum_Sham, Serum_LRIP0, Serum_LRIP1, respectively). The effects of LRIP serum on ROS level and neutrophils activation were determined. The expression of MyD88-TRAF6-MAPKs and PI3K/AKT pathways in neutrophils were examined.

Results

When compared with Serum_Sham, Serum_LRIP0 and Serum_LRIP1 significantly reduced the ROS released from neutrophils activated by fMLP. Meanwhile, the mRNA expression levels of NADPH oxidase subunit p22^phox and multiple ROS-producing related key proteins, such as NADPH oxidase subunit p47^phox ser 304, ser 345. MyD88, p-ERK, p-JNK and p-P38 expression of neutrophils were downregulated by Serum_LRIP0 and Serum_LRIP1. Serum_LRIP1 also downregulated p47^phox mRNA expression and tumor necrosis factor receptor-associated factor 6 (TRAF6) protein expression.

Conclusion

LRIP serum protects against ROS level and neutrophils activation involving the MyD88-TRAF6-MAPKs. This finding provides new insight into the understanding of LRIP mechanisms.

Challenges and Improvements of Novel Therapies for Ischemic Stroke

Stroke is the third most common disease all over the world, which is regarded as a hotspot in medical research because of its high mortality and morbidity. Stroke, especially ischemic stroke, causes severe neural cell death, and no effective therapy is currently available for neuroregeneration after stroke. Although many therapies have been shown to be effective in preclinical studies of ischemic stroke, almost none of them passed clinical trials, and the reasons for most failures have not been well identified. In this review, we focus on several novel methods, such as traditional Chinese medicine, stem cell therapy, and exosomes that have not been used for ischemic stroke till recent decades. We summarize the proposed basic mechanisms underlying these therapies and related clinical results, discussing advantages and current limitations for each therapy emphatically. Based on the limitations such as side effects, narrow therapeutic window, and less accumulation at the injury region, structure transformation and drug combination are subsequently applied, providing a deep understanding to develop effective treatment strategies for ischemic stroke in the near future.

Protocatechudehyde improves mitochondrial energy metabolism through the HIF1α/PDK1 signaling pathway to mitigate ischemic stroke-elicited internal capsule injury

ETHNOPHARMACOLOGICAL RELEVANCE

The internal capsule is vulnerable to ischemia, and mild ischemic stroke often results in lesion of the internal capsule, manifested as contralateral hemiplegia. Protocatechudehyde (PCA), a potential neuroprotective agent, has shown therapeutic effects in the study of a variety of nervous system diseases, including ischemic stroke.

AIM OF THE STUDY

The aim of this study was to evaluate the effects of PCA on cerebral ischemia reperfusion (CI/R)-elicited internal capsule injury and to elucidate the role of mitochondrial energy metabolism in the underlying mechanism of neuroprotective effects on ischemic stroke.

MATERIALS AND METHODS

A rat tMCAO model was established to investigate the therapeutic effects of intravenous PCA (20, 40, and 80 mg/kg, once per day, continued for 7 days) on CI/R-induced internal capsule injury and the regulation of PCA on molecules related to mitochondrial energy metabolism. In vitro, an OGD/R model of PC12 cells was established to further verify the therapeutic mechanism of PCA.

RESULTS

Results showed that PCA dose-dependently attenuated neurological deficit, reduced cerebral infarction, alleviated histopathological damage, and improved mitochondrial ultrastructure of the internal capsule after CI/R. Moreover, PCA reversed the upregulation of HIF1α, PDK1 and pPDHA1 expression induced by CI/R and significantly increased the content of acetyl-CoA, ATP, and the activity of ATP synthase. In vitro, PCA treatment promoted cell survival, inhibited apoptosis, attenuated the dissipation of mitochondrial membrane potential in OGD/R-treated PC12 cells, and these therapeutic effects were reversed by the combination of cobalt chloride (CoCl₂), a specific pharmacological inducer of HIF1a expression.

CONCLUSIONS

These results indicate that PCA exerts a protective effect against CI/R-induced internal capsule injury and improves mitochondrial energy metabolism in the internal capsule, and the mechanism is associated with the inhibition of HIF1α/PDK1 signaling pathway.

Notoginsenoside R1 intervenes degradation and redistribution of tight junctions to ameliorate blood-brain barrier permeability by Caveolin-1/MMP2/9 pathway after acute ischemic stroke

BACKGROUND

The leakage of blood-brain barrier (BBB) is main pathophysiological change in acute stage of ischemic stroke, which not only deteriorates neurological function, but also increases the risk of hemorrhagic transformation after thrombolysis.

PURPOSE/STUDY DESIGN

This article investigates the efficacy of Notoginsenoside R1, an active ingredient of Panax notoginseng, on BBB permeability and explores related mechanisms after acute ischemic stroke.

METHODS

In vivo, male Sprague-Dawley rats (260-280 g) were selected and randomly divided into 6 groups: sham group, model group, low, middle and high doses of Notoginsenoside R1 groups and positive drug Dl-3-n-Butylphthalide group. Except for sham group, rats were performed with permanent middle cerebral artery occlusion model in each group. Twelve hours later, rats were evaluated for Bederson neurological function, and BBB integrity by Evans blue leak imaging; Triphenyltetrazolium chloride staining was used to detect the volume of cerebral infarction. Frozen sections of rats' brain tissue were prepared for detection of MMPs activity in situ zymography. Peripheral tissue of cerebral infarction was collected and tested the expression of MMP2, 9 and tight junction proteins (zo1, claudin5, occludin) by western blot. In vitro, transwell endothelial barrier model was established by bEnd.3 cells. Oxygen glucose deprivation (OGD) was chosen to simulate the hypoxic environment. Suitable OGD stimulation time as well as Notoginsenoside R1 and Dl-3-n-Butylphthalide optimal dose concentrations were determined through transwell leakage and CCK8 assay. Furthermore, endothelial subcellular component proteins were extracted. The change of zo1, claudin5, occludin and caveolin1 was detected by western blot.

RESULTS

Notoginsenoside R1 treatment significantly reduced BBB leakage and cerebral infarction volume, weakened neurological deficits in post-stroke rats. Moreover, it inhibited the activity of MMPs in infarcted cortex and striatum, down-regulated MMP2, 9 and up-regulated zo1 and claudin5 expressions in penumbra. In vitro, Notoginsenoside R1 treatment decreased OGD-induced endothelial barrier permeability, restored expressions of zo1, claudin5 on cellular membrane and cytoplasm, as well as mediated membrane redistribution of occludin and caveolin1 from actin cytoskeletal fraction.

CONCLUSIONS

Notoginsenoside R1 treatment attenuates BBB permeability, cerebral infarction volume and neurological impairments in rats with acute cerebral ischemia. The mechanisms might be related to intervening degradation and redistribution of zo1, caludin5 and occludin by caveolin1/ MMP2/9 pathway. More effects and mechanisms of Notoginsenoside R1 on rehabilitation of stroke are worthy to be explored in the future.

Influence of Early Enteral Nutrition on Clinical Outcomes in Neurocritical Care Patients With Intracerebral Hemorrhage

Objective: Early enteral nutrition (EEN) represents the current standard of care for patients treated in general intensive care units (ICU). Specific nutritional recommendations for patients receiving dedicated neurocritical care are not established. This study investigated associations of EEN with clinical outcomes for patients suffering from intracerebral hemorrhage treated at a neurological ICU (NICU).

Methods: This retrospective cohort study included patients admitted to the NICU with atraumatic ICH over a 4-year period. Nutritional data, demographic, clinical, radiological, and laboratory characteristics were assessed. EEN was defined as any enteral nutrition within 48 hours after admission. Comparisons were undertaken for patients with EEN vs. those without, further propensity score (PS) matching (caliper 0.2; one: many) was used to account for baseline imbalances. Primary outcome was the modified Rankin Scale (0–3 = favorable, 4–6 = unfavorable) at 12 months, secondary outcomes comprised perihemorrhagic edema (PHE) volume, infectious complications during the hospital stay, and mRS at 3 months, as well as mortality rates at 3 and 12 months.

Results: Of 166 ICH-patients treated at the NICU, 51 (30.7%) patients received EEN, and 115 (69.3%) patients received no EEN (nEEN). After propensity score matching, calories delivered from enteral nutrition (EEN 161.4 [106.4–192.3] kcal/day vs. nEEN 0.0 [0.0–0.0], P < 0.001) and the total calories (EEN 190.0 [126.0–357.0] kcal/day vs. nEEN 33.6 [0.0–190.0] kcal/day, P < 0.001) were significantly different during the first 48 h admitted in NICU. Functional outcome at 12 months (mRS 4–6, EEN 33/43 [76.7%] vs. nEEN, 49/64 [76. 6%]; P = 1.00) was similar in the two groups. There were neither differences in mRS at 3 months, nor in mortality rates at 3 and 12 months between the two groups. EEN did not affect incidence of infective complications or gastrointestinal adverse events during the hospital stay; however, EEN was associated with significantly less extent of PHE evolution [maximum absolute PHE (OR 0.822, 95% CI 0.706–0.957, P = 0.012); maximum relative PHE (OR 0.784, 95% CI 0.646–0.952, P = 0.014)].

Conclusion: In our study, EEN was associated with reduced PHE in ICH-patients treated at a NICU. However, this observation did not translate into improved survival or functional outcome at 3 and 12 months.

Hemorrhagic Transformation After Tissue Plasminogen Activator Treatment in Acute Ischemic Stroke

Hemorrhagic transformation (HT) is a common complication after thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) in ischemic stroke. In this article, recent research progress of HT in vivo and in vitro studies was reviewed. We have discussed new potential mechanisms and possible experimental models of HT development, as well as possible biomarkers and treatment methods. Meanwhile, we compared and analyzed rodent models, large animal models and in vitro BBB models of HT, and the limitations of these models were discussed. The molecular mechanism of HT was investigated in terms of BBB disruption, rt-PA neurotoxicity and the effect of neuroinflammation, matrix metalloproteinases, reactive oxygen species. The clinical features to predict HT were represented including blood biomarkers and clinical factors. Recent progress in neuroprotective strategies to improve HT after stroke treated with rt-PA is outlined. Further efforts need to be made to reduce the risk of HT after rt-PA therapy and improve the clinical prognosis of patients with ischemic stroke.

Curcumin-laden exosomes target ischemic brain tissue and alleviate cerebral ischemia-reperfusion injury by inhibiting ROS-mediated mitochondrial apoptosis

The pathogenesis of ischemic cerebrovascular disease has revealed that ischemia-reperfusion (I/R) injury often leads to aggravation of metabolic oxidative stress and blood-brain barrier (BBB) destruction, eventually causing secondary brain tissue damage. Accumulated reactive oxygen species (ROS) in focal ischemia activate mitochondria-mediated apoptosis and damage the BBB by degrading tight junction proteins (TJPs). Herein, we report macrophage-derived exosomes (Ex) loaded with curcumin (cur) as a multifunctional biomimetic delivery vehicle (Ex-cur) for targeting ischemic brain tissue and alleviating cerebral I/R injury by inhibiting ROS-mediated mitochondrial apoptosis in a transient cerebral ischemia rat model. The design principle relies on unique features of macrophage-derived exosomes and the natural ingredient cur. Specifically, cur can be entrapped within exosomes when incubated with murine macrophage RAW264.7 cells, and its stability is subsequently significantly improved. The resultant Ex-cur can target ischemic regions by leveraging the targeting migration capability of Ex driven by inflammation. Accumulated Ex-cur in ischemic regions is experimentally proven to be highly effective at reducing ROS accumulation by virtue of the antioxidant properties of cur. Using Ex-cur to down-regulate ROS accumulation in lesions, we alleviate BBB damage and suppress mitochondria-mediated neuronal apoptosis, which is confirmed by a series of relevant protein analysis. These findings demonstrate good therapeutic efficacy of Ex-cur for treating I/R injury, providing experimental evidence for the potential clinical benefits of Ex-cur for other modes of neuroprotection.

Let-7g* and miR-98 Reduce Stroke-Induced Production of Proinflammatory Cytokines in Mouse Brain

Stroke is a debilitating illness facing healthcare today, affecting over 800,000 people and causing over 140,000 deaths each year in the United States. Despite being the third-leading cause of death, very few treatments currently exist for stroke. Often, during an ischemic attack, the blood-brain barrier (BBB) is significantly damaged, which can lead to altered interactions with the immune system, and greatly worsen the damage from a stroke. The impaired, BBB promotes the infiltration of peripheral inflammatory cells into the brain, secreting deleterious mediators (cytokines/chemokines) and resulting in permanent barrier injury. let-7 microRNAs (miRs) are critical for regulating immune responses within the BBB, particularly after ischemic stroke. We have previously shown how transient stroke decreases expression of multiple let-7 miRs, and that restoration of expression confers significant neuroprotection, reduction in brain infiltration by neutrophils, monocytes and T cells. However, the specific mechanisms of action of let-7 miRs remain unexplored, though emerging evidence implicates a range of impacts on cytokines. In the current study, we evaluate the impacts of miR-98 and let-7g* on targeting of cytokine mRNAs, cytokine release following ischemic stroke, and cell-specific changes to the neurovascular space. We determined that miR-98 specifically targets IP-10, while let-7g* specifically aims IL-8, and attenuates their levels. Both produce strong impacts on CCL2 and CCL5. Further, let-7g* strongly improves neurovascular perfusion following ischemic stroke. Together, the results of the study indicate that let-7 miRs are critical for mediating endothelial-immune reactions and improving recovery following ischemic stroke.

Schisandrin B improves cerebral ischemia and reduces reperfusion injury in rats through TLR4/NF-κB signaling pathway inhibition

It has been established that poor outcomes in ischemic stroke patients are associated with the post-reperfusion inflammatory response and up-regulation of TLR4. Therefore, suppression of the TLR4 signaling pathway constitutes a potential neuroprotective therapeutic strategy. Schisandrin B, a compound extracted from Schisandra chinensis, has been shown to possess anti-inflammatory and neuroprotective properties. However, the mechanism remains unclear. In the present study, the therapeutic effect of schisandrin B was assessed following cerebral ischemia and reperfusion (I/R) injury in a model of middle cerebral artery occlusion and reperfusion (MCAO/R) in rats. The effects of schisandrin B were investigated with particular emphasis on TLR4 signal transduction and on the inflammatory response. Schisandrin B treatment conferred significant protection against MCAO/R injury, as evidenced by decreases in infarct volume, neurological score, and the number of apoptotic neurons and inflammatory signaling molecules.

ABBREVIATIONS

I/R: schemia/reperfusion; IL: interleukin; MCAO/R: middle cerebral artery occlusion and reperfusion; NF-κB: nuclear; TLR4: Toll-like receptor 4; TNF-α: tumor necrosis factor-α.

let-7g counteracts endothelial dysfunction and ameliorating neurological functions in mouse ischemia/reperfusion stroke model

Stroke is a debilitating disease, accounting for almost 20% of all hospital visits, and 8% of all fatalities in the United States in 2017. Following an ischemic attack, inflammatory processes originating from endothelial cells within the brain microvasculature can induce many toxic effects into the impacted area, from both sides of the blood brain barrier (BBB). In addition to increased BBB permeability, impacted brain microvascular endothelial cells can recruit macrophages and other immune cells from the periphery and can also trigger the activation of microglia and astrocytes within the brain. We have identified a key microRNA, let-7g, which levels were drastically diminished as consequence of transient middle cerebral artery occlusion (tMCAO) in vivo and oxygen-glucose deprivation (OGD) in vitro ischemia/reperfusion conditions, respectively. We have observed that let-7g* liposome-based delivery is capable of attenuating inflammation after stroke, reducing BBB permeability, limiting brain infiltration by CD3+CD4+ T-cells and Ly6G+ neutrophils, lessening microglia activation and neuronal death. These effects consequently improved clinical outcomes, shown by mitigating post-stroke gait asymmetry and extremity motor function. Due to the role of the endothelium in propagating the effects of stroke and other inflammation, treatments which can reduce endothelial inflammation and limit ischemic damage and improving recovery after a stroke are required. Our findings demonstrate a critical link between the CNS inflammation and the immune system reaction and lay important groundwork for future stroke pharmacotherapies.

Protection against acute cerebral ischemia/reperfusion injury by QiShenYiQi via neuroinflammatory network mobilization

Cerebral ischemia/reperfusion injury (CI/RI) is a common feature of ischemic stroke, involving a period of impaired blood supply to the brain, followed by the restoration of cerebral perfusion through medical intervention. Although ischemia and reperfusion brain damage is a complex pathological process with an unclear physiological mechanism, more attention is currently focused on the neuroinflammatory response of an ischemia/reperfusion origin, and anti-inflammatory appears to be a potential therapeutic strategy following ischemic stroke. QiShenYiQi (QSYQ), a component-based Chinese medicine with Qi-tonifying and blood-activating property, has pharmacological actions of anti-inflammatory, antioxidant, mitochondrial protectant, anti-apoptosis, and antiplatelet aggregation. We have previously reported that the cardioprotective effect of QSYQ against ischemia/reperfusion injury is via improvement of mitochondrial functional integrity. In this research work, we aimed to investigate the possible mechanism involved in the neuroprotection of QSYQ in mice model of cerebral ischemia/reperfusion injury based on the inflammatory pathway. The cerebral protection was evaluated in the stroke mice after 24 h reperfusion by assessing the neurological deficit, cerebral infarction, brain edema, BBB functionality, and via histopathological assessment. TCM-based network pharmacology method was performed to establish and analyze compound-target-disease & function-pathway network so as to find the possible mechanism linking to the role of QSYQ in CI/RI. In addition, RT-qPCR was used to verify the accuracy of predicted signaling gene expression. As a result, improvement of neurological outcome, reduction of infarct volume and brain edema, a decrease in BBB disruption, and amelioration of histopathological alteration were observed in mice pretreated with QSYQ after experimental stroke surgery. Network pharmacology analysis revealed neuroinflammatory response was associated with the action of QSYQ in CI/RI. RT-qPCR data showed that the mice pretreated with QSYQ could significantly decrease IFNG-γ, IL-6, TNF-α, NF-κB p65, and TLR-4 mRNA levels and increase TGF-β1 mRNA level in the brain compared to the untreated mice after CI/RI (p < 0.05). In conclusion, our study indicated the cerebral protective effect of pretreatment with QSYQ against CI/RI, which may be partly related to its potential to the reduction of neuroinflammatory response in a stroke subject.

YangXue QingNao Wan, a Compound Chinese Medicine, Attenuates Cerebrovascular Hyperpermeability and Neuron Injury in Spontaneously Hypertensive Rat: Effect and Mechanism

Objective

The purpose of the study was to explore the effect of YangXue QingNao Wan (YXQNW), a compound Chinese medicine, on cerebrovascular hyperpermeability, neuronal injury, and related mechanisms in spontaneously hypertensive rat (SHR).

Methods

Fourteen-week-old male SHR were used, with Wistar Kyoto (WKY) rats as control. YXQNW (0.5 g/kg/day), enalapril (EN, 8 mg/kg/day), and nifedipine (NF, 7.1 mg/kg/day) were administrated orally for 4 weeks. To assess the effects of the YXQNW on blood pressure, the systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) were measured. After administering the drugs for 4 weeks, the cerebral blood flow (CBF), albumin leakage from microvessels in middle cerebral artery (MCA)-dominated area, and the number and morphology of microvessels were assessed in the hippocampus area and cortex. Neuronal damage and apoptosis were assessed by Nissl staining and TUNEL staining. To assess the mechanisms of cerebrovascular hyperpermeability, we performed immunofluorescence and Western blot to assess the expression and integrity of cerebral microvascular tight junction (TJ) and caveolin-1 (Cav-1) in cortex. Energy metabolism and Src-MLC-MLCK pathway in cortex were assessed then for elucidating the underlying mechanism of the observed effect of YXQNW.

Results

Spontaneously hypertensive rat exhibited higher blood pressure, Evans blue (EB) extravasation, albumin leakage, increased brain water content, decreased CBF, perivascular edema, and neuronal apoptosis in the hippocampus and cortex, all of which were attenuated by YXQNW treatment. YXQNW inhibited the downregulation of TJ proteins, mitochondrial Complex I, Complex II, and Complex V, and upregulation of caveolin-1, inhibiting Src/MLCK/MLC signaling in SHR. YXQNW combined with EN + NF revealed a better effect for some outcomes compared with either YXQNW or EN + NF alone.

Conclusion

The overall result shows the potential of YXQNW to attenuate blood–brain barrier (BBB) breakdown in SHR, which involves regulation of energy metabolism and Src/MLCK/MLC signaling. This result provides evidence supporting the application of YXQNW as an adjuvant management for hypertensive patients to prevent hypertensive encephalopathy.

Yiqifumai injection and its main ingredients attenuate lipopolysaccharide-induced cerebrovascular hyperpermeability through a multi-pathway mode

OBJECTIVE

Yiqifumai injection is a compound Chinese medicine used to treat microcirculatory disturbance-related diseases clinically. Our previous study proved that Yiqifumai injection pretreatment inhibited lipopolysaccharide-induced venular albumin leakage in rat mesentery. This study aimed to investigate whether Yiqifumai injection attenuated cerebral microvascular hyperpermeability and corresponding contribution of its main ingredients.

METHODS

Rats were challenged by lipopolysaccharide infusion (5 mg/kg/h) for 90 minutes. Yiqifumai injection (160 mg/kg/h), Rb1 (5 mg/kg/h), Sch (2.5 mg/kg/h), and Rb1 (5 mg/kg/h) + Sch (2.5 mg/kg/h) were infused 30 minutes before (pretreatment) or after (post-treatment) lipopolysaccharide administration.

RESULTS

Both pretreatment and post-treatment with Yiqifumai injection attenuated cerebral venular albumin leakage during lipopolysaccharide infusion and cerebrovascular hyperpermeability at 72 hours after lipopolysaccharide infusion. Yiqifumai injection restrained the decreased junction protein expression, adenosine triphosphate content, and mitochondria complex I, II, IV, and V activities. Moreover, Yiqifumai injection inhibited toll-like receptor-4 expression, Src phosphorylation, and caveolin-1 expression. Its main ingredients Rb1 and Sch alone worked differently, with Rb1 being more effective for enhancing energy metabolism, while Sch attenuating toll-like receptor-4 expression and Src activation.

CONCLUSION

Yiqifumai injection exerts a protective and ameliorated effect on cerebral microvascular hyperpermeability, which is more effective than any of its ingredients, possibly due to the interaction of its main ingredients through a multi-pathway mode.

Network Pharmacology-Guided Development of a Novel Integrative Regimen to Prevent Acute Graft-vs.-Host Disease

Lapses in the graft-vs.-host disease (GVHD) prophylaxis and side effects of current standard care following allogeneic hematopoietic stem cell transplantation (allo-HSCT) call for novel regimens. Traditional approaches targeting T cells showed limited success in preventing acute GVHD (aGVHD). System medicine showed promising results treating complex diseases such as sepsis and multi-organ dysfunction syndrome (MODS). Adapting established network pharmacology analysis methods, we aimed to develop novel integrative regimens to prevent aGVHD. Our network pharmacology analysis predicted that Xuebijing injection (XBJ) targets a series of key node proteins in aGVHD network. It also unveiled that Salviae miltiorrhizae (Danshen), an herb in Xuebijing formula, which prevented aGVHD in rats, shares five out of six key GVHD node proteins targeted by XBJ. Interestingly, network pharmacology analysis indicated Xuebijing may share multiple aGVHD targets with Cyclosporin A (CsA), a first-line drug for preventing aGVHD in the clinic. Based on current information, we hypothesized that combination of XBJ and CsA may yield superior results in aGVHD prevention than either drug alone. We performed in vitro and in vivo assays to validate the predictions by the network pharmacology analysis. In vitro assays revealed XBJ prevented platelet aggregation and NF-κB nuclear translocation in macrophages. XBJ also promoted angiogenesis in tube-formation assay. Importantly, the combination of CsA and XBJ was effective in rescuing mice subjected to lethal GVHD. XBJ contributed to the rescue through preventing NF-κB nuclear translocation, attenuating inflammation and maintaining viability of macrophages. Overall, network pharmacology is a powerful tool to develop novel integrative regimens. Combination of XBJ and CsA may shed light on preventing aGVHD.