Endothelial Conditional Knockdown of NMMHC IIA (Nonmuscle Myosin Heavy Chain IIA) Attenuates Blood-Brain Barrier Damage During Ischemia-Reperfusion Injury

Neferine inhibits BMECs pyroptosis and maintains blood-brain barrier integrity in ischemic stroke by triggering a cascade reaction of PGC-1α

Blood-brain barrier disruption is a critical pathological event in the progression of ischemic stroke (IS). Most studies regarding the therapeutic potential of neferine (Nef) on IS have focused on neuroprotective effect. However, whether Nef attenuates BBB disruption during IS is unclear. We here used mice underwent transient middle cerebral artery occlusion (tMCAO) in vivo and bEnd.3 cells exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro to simulate cerebral ischemia. We showed that Nef reduced neurobehavioral dysfunction and protected brain microvascular endothelial cells and BBB integrity. Molecular docking, short interfering (Si) RNA and plasmid transfection results showed us that PGC-1α was the most binding affinity of biological activity protein for Nef. And verification experiments were showed that Nef upregulated PGC-1α expression to reduce mitochondrial oxidative stress and promote TJ proteins expression, further improves the integrity of BBB in mice. Intriguingly, our study showed that neferine is a natural PGC-1α activator and illustrated the mechanism of specific binding site. Furthermore, we have demonstrated Nef reduced mitochondria oxidative damage and ameliorates endothelial inflammation by inhibiting pyroptosis to improve BBB permeability through triggering a cascade reaction of PGC-1α via regulation of PGC-1α/NLRP3/GSDMD signaling pathway to maintain the integrity of BBB in ischemia/reperfusion injury.

Trilobatin attenuates cerebral ischaemia/reperfusion-induced blood-brain barrier dysfunction by targeting matrix metalloproteinase 9: The legend of a food additive

BACKGROUND AND PURPOSE

Blood-brain barrier (BBB) breakdown is one of the crucial pathological changes of cerebral ischaemia-reperfusion (I/R) injury. Trilobatin (TLB), a naturally occurring food additive, exerts neuroprotective effects against cerebral I/R injury as demonstrated in our previous study. This study was designed to investigate the effect of TLB on BBB disruption after cerebral I/R injury.

EXPERIMENTAL APPROACH

Rats with focal cerebral ischaemia caused by transient middle cerebral artery occlusion were studied along with brain microvascular endothelial cells and human astrocytes to mimic BBB injury caused by oxygen and glucose deprivation/reoxygenation (OGD/R).

KEY RESULTS

The results showed that TLB effectively maintained BBB integrity and inhibited neuronal loss following cerebral I/R challenge. Furthermore, TLB increased tight junction proteins including ZO-1, Occludin and Claudin 5, and decreased the levels of apolipoprotein E (APOE) 4, cyclophilin A (CypA) and phosphorylated nuclear factor kappa B (NF-κB), thereby reducing proinflammatory cytokines. TLB also decreased the Bax/Bcl-2 ratio and cleaved-caspase 3 levels along with a reduced number of apoptotic neurons. Molecular docking and transcriptomics predicted MMP9 as a prominent gene evoked by TLB treatment. The protective effects of TLB on cerebral I/R-induced BBB breakdown was largely abolished by overexpression of MMP9, and the beneficial effects of TLB on OGD/R-induced loss of BBB integrity in human brain microvascular endothelial cells and astrocyte co-cultures was markedly reinforced by knockdown of MMP9.

CONCLUSIONS AND IMPLICATIONS

Our findings reveal a novel property of TLB: preventing BBB disruption following cerebral I/R via targeting MMP9 and inhibiting APOE4/CypA/NF-κB axis.

Suppression of cerebral ischemia injury induced blood brain barrier breakdown by dexmedetomidine via promoting CCN1

BACKGROUND

Blood-brain barrier (BBB) could aggravate cerebral ischemia injury. Dexmedetomidine (Dex) has been believed to play a protective role in cerebral ischemia injury-induced BBB injury.

METHODS

Middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD) models were established to simulate cerebral ischemia injury. Animal experiments included 4 groups, Sham, MCAO, MCAO+Dex, MCAO+Dex+sh-CCN1. Generally applicable gene set enrichment analysis was performed to analyze gene expression difference. Total collagen content and Evans blue staining were performed to measure infarct ratio and BBB breakdown, respectively. The cell apoptosis, mRNA and protein expression were measured through flow cytometry, PCR, and western blotting, respectively. The levels of IL-1β, TNF-α, and IL-6 in serum were measured with commercial ELISA kits.

RESULTS

Dex greatly promoted the expression level of CCN1. Dex suppressed cerebral ischemia injury, increased tight junction protein expression, improved the memory ability and neurological function of MCAO rats through targeting CCN1. The significant increase of inflammatory factors in the serum of MCAO rats were suppressed by Dex. Dex suppressed OGD induced increase of HRP permeability and promoting tight junction protein expression in vitro through regulating CCN1. The neurological function evaluation was performed with Neurological Severity Score (NSS) and Longa Score Scale.

CONCLUSIONS

Dex could remarkably alleviate cerebral ischemia injury by inhibiting BBB breakdown, inflammatory response, and promoting neurological function and tight junction protein expression via up-regulating CCN1. This study might provide a novel therapeutic target for the prevention and treatment of cerebral ischemia injury-induced BBB.

Erdr1 Drives Macrophage Programming via Dynamic Interplay with YAP1 and Mid1

Erythroid differentiation regulator 1 (Erdr1) is a stress-induced, widely expressed, highly conserved secreted factor found in both humans and mice. Erdr1 is linked with the Hippo-YAP1 signaling. Initially identified as an inducer of hemoglobin synthesis, Erdr1 emerged as a multifunctional protein, especially in immune cells. Although Erdr1 has been implicated in regulating T cells and NK cell function, its role in macrophage remains unclear. This study explored the function and mechanism of Erdr1 in macrophage inflammatory response. The data demonstrated that Erdr1 could promote anti-inflammatory cytokine production, a function that also has been reported by previous research. However, I found Erdr1 also could play a proinflammatory role. The function of Erdr1 in macrophages depends on its dose and cell density. I observed that Erdr1 expression was inhibited in M1 macrophages but was upregulated in M2 macrophages compared with unpolarized macrophages. I hypothesized that Erdr1 balances the inflammatory response by binding with distinct adaptors dependent on varying concentrations. Mechanistically, I demonstrated YAP1 and Mid1 as the two adaptor proteins of Erdr1. The Erdr1-YAP1 interaction promotes anti-inflammatory cytokine production when Erdr1 levels are elevated, whereas the Erdr1-Mid1 interaction induces proinflammatory cytokine production when Erdr1 levels are decreased. This study highlights the effects of Erdr1 on regulating cytokine production from polarized macrophages potentially by regulating YAP1 in the nonclassical Hippo pathway.

Erdr1 orchestrates macrophage polarization and determines cell fate via dynamic interplay with YAP1 and Mid1

Erythroid differentiation regulator 1 (Erdr1) is a stress-induced, widely distributed, extremely conserved secreted factor found in both humans and mice. Erdr1 is highly linked with the Hippo-YAP1 signaling. Initially identified as an inducer of hemoglobin synthesis, it has emerged as a multifunctional protein, especially in immune cells. Although Erdr1 has been implicated in T cells and NK cell function, its role in macrophage remains unclear. This study aims to explore the function and mechanism of Erdr1 in IL-1β production in macrophages. Data manifest Erdr1 could play an inhibition role in IL-1β production, which also has been reported by previous research. What significance is we discovered Erdr1 can promote IL-1β production which is associated with Erdr1 dose and cell density. We observed that Erdr1 was inhibited in pro-inflammatory (M1) macrophages but was upregulated in anti-inflammatory (M2) macrophages compared to naive macrophages. We hypothesized that Erdr1 dual drives and modulates IL-1β production by binding with distinct adaptors via concentration change. Mechanistically, we demonstrated that Erdr1 dual regulates IL-1β production by dynamic interaction with YAP1 and Mid1 by distinct domains. Erdr1-YAP1 interplay mediates macrophage M2 polarization by promoting an anti-inflammatory response, enhancing catabolic metabolism, and leading to sterile cell death. Whereas, Erdr1-Mid1 interplay mediates macrophage M1 polarization by initiating a pro-inflammatory response, facilitating anabolic metabolism, and causing inflammatory cell death. This study highlights Erdr1 orchestrates macrophage polarization and determines cell date by regulating YAP1 through non-classical Hippo pathway.

Single-cell RNA sequencing unveils Lrg1's role in cerebral ischemia‒reperfusion injury by modulating various cells

BACKGROUND AND PURPOSE

Cerebral ischemia‒reperfusion injury causes significant harm to human health and is a major contributor to stroke-related deaths worldwide. Current treatments are limited, and new, more effective prevention and treatment strategies that target multiple cell components are urgently needed. Leucine-rich alpha-2 glycoprotein 1 (Lrg1) appears to be associated with the progression of cerebral ischemia‒reperfusion injury, but the exact mechanism of it is unknown.

METHODS

Wild-type (WT) and Lrg1 knockout (Lrg1-/-) mice were used to investigate the role of Lrg1 after cerebral ischemia‒reperfusion injury. The effects of Lrg1 knockout on brain infarct volume, blood‒brain barrier permeability, and neurological score (based on 2,3,5-triphenyl tetrazolium chloride, evans blue dye, hematoxylin, and eosin staining) were assessed. Single-cell RNA sequencing (scRNA-seq), immunofluorescence, and microvascular albumin leakage tests were utilized to investigate alterations in various cell components in brain tissue after Lrg1 knockout.

RESULTS

Lrg1 expression was increased in various cell types of brain tissue after cerebral ischemia‒reperfusion injury. Lrg1 knockout reduced cerebral edema and infarct size and improved neurological function after cerebral ischemia‒reperfusion injury. Single-cell RNA sequencing analysis of WT and Lrg1-/- mouse brain tissues after cerebral ischemia‒reperfusion injury revealed that Lrg1 knockout enhances blood‒brain barrier (BBB) by upregulating claudin 11, integrin β5, protocadherin 9, and annexin A2. Lrg1 knockout also promoted an anti-inflammatory and tissue-repairing phenotype in microglia and macrophages while reducing neuron and oligodendrocyte cell death.

CONCLUSIONS

Our results has shown that Lrg1 mediates numerous pathological processes involved in cerebral ischemia‒reperfusion injury by altering the functional states of various cell types, thereby rendering it a promising therapeutic target for cerebral ischemia‒reperfusion injury.

The blood-brain barrier, a key bridge to treat neurodegenerative diseases

As a highly selective and semi-permeable barrier that separates the circulating blood from the brain and central nervous system (CNS), the blood-brain barrier (BBB) plays a critical role in the onset and treatment of neurodegenerative diseases (NDs). To delay or reverse the NDs progression, the dysfunction of BBB should be improved to protect the brain from harmful substances. Simultaneously, a highly efficient drug delivery across the BBB is indispensable. Here, we summarized several methods to improve BBB dysfunction in NDs, including knocking out risk geneAPOE4, regulating circadian rhythms, restoring the gut microenvironment, and activating the Wnt/β-catenin signaling pathway. Then we discussed the advances in BBB penetration techniques, such as transient BBB opening, carrier-mediated drug delivery, and nasal administration, which facilitates drug delivery across the BBB. Furthermore, various in vivo and in vitro BBB models and research methods related to NDs are reviewed. Based on the current research progress, the treatment of NDs in the long term should prioritize the integrity of the BBB. However, a treatment approach that combines precise control of transient BBB permeability and non-invasive targeted BBB drug delivery holds profound significance in improving treatment effectiveness, safety, and clinical feasibility during drug therapy. This review involves the cross application of biology, materials science, imaging, engineering and other disciplines in the field of BBB, aiming to provide multi-dimensional research directions and clinical ideas for the treating NDs.

Ruscogenin Alleviates Myocardial Ischemia via Myosin IIA-Dependent Mitochondrial Fusion and Fission Balance

Ruscogenin (RUS), a major effective steroidal sapogenin derived from Ophiopogon japonicas, has been reported to alleviate myocardial ischemia (MI), but its cardioprotective mechanism is still not completely clear. In this study, we observed that RUS markedly reduced MI-induced myocardial injury, as evidenced by notable reductions in infarct size, improvement in biochemical markers, alleviation of cardiac pathology, amelioration of mitochondrial damage, and inhibition of myocardial apoptosis. Moreover, RUS notably suppressed oxygen-glucose deprivation (OGD)-triggered cell injury and apoptosis. Notably, RUS demonstrated a considerable decrease of the interaction between myosin IIA and F-actin, along with the restoration of mitochondrial fusion and fission balance. We further confirmed that the effects of RUS on MI were mediated by myosin IIA using siRNA and overexpression techniques. The inhibition of myosin IIA resulted in a significant improvement of mitochondrial fusion and fission imbalance, while simultaneously counteracting the beneficial effects of RUS. By contrast, overexpression of myosin IIA aggravated the imbalance between mitochondrial fusion and fission and partially weakened the protection of RUS. These findings suggest that myosin IIA is essential or even a key functional protein in the cardioprotection of RUS. Overall, our results have elucidated an undiscovered mechanism involving myosin IIA-dependent mitochondrial fusion and fission balance for treating MI. Furthermore, our study has uncovered a novel mechanism underlying the protective effects of RUS.

Identification of hypoxia-related genes and exploration of their relationship with immune cells in ischemic stroke

Ischemic stroke (IS) is a major threat to human health, and it is the second leading cause of long-term disability and death in the world. Impaired cerebral perfusion leads to acute hypoxia and glucose deficiency, which in turn induces a stroke cascade response that ultimately leads to cell death. Screening and identifying hypoxia-related genes (HRGs) and therapeutic targets is important for neuroprotection before and during brain recanalization to protect against injury and extend the time window to further improve functional outcomes before pharmacological and mechanical thrombolysis. First, we downloaded the GSE16561 and GSE58294 datasets from the NCBI GEO database. Bioinformatics analysis of the GSE16561 dataset using the limma package identified differentially expressed genes (DEGs) in ischemic stroke using adj. p. values < 0.05 and a fold change of 0.5 as thresholds. The Molecular Signature database and Genecards database were pooled to obtain hypoxia-related genes. 19 HRGs associated with ischemic stroke were obtained after taking the intersection. LASSO regression and multivariate logistic regression were applied to identify critical biomarkers with independent diagnostic values. ROC curves were constructed to validate their diagnostic efficacy. We used CIBERSORT to analyze the differences in the immune microenvironment between IS patients and controls. Finally, we investigated the correlation between HRGs and infiltrating immune cells to understand molecular immune mechanisms better. Our study analyzed the role of HRGs in ischemic stroke. Nineteen hypoxia-related genes were obtained. Enrichment analysis showed that 19 HRGs were involved in response to hypoxia, HIF-1 signaling pathway, autophagy, autophagy of mitochondrion, and AMPK signaling pathway. Because of the good diagnostic properties of SLC2A3, we further investigated the function of SLC2A3 and found that it is closely related to immunity. We have also explored the relevance of other critical genes to immune cells. Our findings suggest that hypoxia-related genes play a crucial role in the diversity and complexity of the IS immune microenvironment. Exploring the association between hypoxia-related critical genes and immune cells provides innovative insights into the therapeutic targets for ischemic stroke.

Silencing of ALOX15 reduces ferroptosis and inflammation induced by cerebral ischemia-reperfusion by regulating PHD2/HIF2α signaling pathway

OBJECTIVE

To investigate the potential mechanism of arachidonic acid deoxyribozyme 15 (ALOX15) in ferroptosis and inflammation induced by cerebral ischemia reperfusion injury.

METHODS

The mice and cell models of cerebral ischemia-reperfusion injury were constructed. Western Blot was used to detect the protein expression levels of ALOX15, glutathione peroxidase (GPX4), hypoxia-inducible factor-2α (HIF-2α), prolyl hydroxylase (PHD) and inflammatory factors (NLRP3, IL-1β, IL-18) in brain tissues and cells. Cell proliferation activity was detected by CCK-8 method. LDH assay was used to detect the release of lactate dehydrogenase. TTC staining was used to observe cerebral infarction.

RESULTS

In cerebral ischemia-reperfusion mice and cell models, the expression of ALOX15 protein was increased, the expression of GPX4, a key marker of ferroptosis was decreased, and silencing of ALOX15 down-regulated the GPX4 expression. HIF-2α expression was down-regulated in animal and cell models of cerebral ischemia reperfusion, and silencing of ALOX15 increased the HIF-2α expression by inhibiting PHD2 expression. Inhibition of ALOX15 expression reduced inflammatory factors levels (NLRP3, IL-1β, and IL-18) in cerebral ischemia. Inhibitor of PHD2 (IXOC-4) alleviating brain injury and cell death induced by cerebral ischemia reperfusion and stabilize HIF-2α expression in vivo.

CONCLUSION

The expression of ALOX15 was up-regulated in cerebral ischemia-reperfusion animals and cells model. Inhibition of ALOX15 up-regulated the GPX4 expression, and promoted HIF-2α expression by inhibiting PHD2, thus alleviating ferroptosis and inflammation caused by cerebral ischemia-reperfusion injury.

Lycium Barbarum polysaccharides ameliorates hyperglycemia-exacerbated cerebral ischemia/reperfusion injury via protecting blood-brain barrier

BACKGROUND

Hyperglycemia exacerbates brain damage in cerebral ischemia/reperfusion injury. Previous study found that Lycium barbarum polysaccharides (LBP) has a neuroprotective effect on hyperglycemia-aggravated ischemic brain injury, which raising the possibility for treatment of neurodegenerative diseases. However, the underlying mechanism of LBP-induced protection by ameliorating hyperglycemia-aggravated ischemia/reperfusion injury needs to be tested. This study aimed to investigate the effects of LBP on blood-brain barrier (BBB) integrity with a hyperglycemia-aggravated cerebral ischemia/reperfusion injury model.

METHODS

Sprague-Dawley male rats were randomly divided into three groups: normoglycemic (NG), hyperglycemic (HG), and LBP-pretreated hyperglycemic (HG + LBP). Animals underwent middle cerebral artery occlusion (MCAO) for 30 min, followed by 1-, 3-, and 7-day of reperfusion.

RESULTS

Our results showed that the neurological deficit, infarct volume, cell apoptosis, and IgG leakage in the HG group significantly increased separately, compared with that of the NG group, (p < 0.05). Pre-treatment with LBP reversed these injury indicators (p < 0.05). And much more severe degree of swelling endothelium, swollen astrocyte, and decreased tight junctions in the micro-vessel were detected in the HG group comparing to that of the NG group. In addition, increased degree of basement membrane degradation, dissociation between the astrocyte endfeet and basement membrane, and tight junction's protein degradation was found in the HG group compared with the NG group (p < 0.05). However, when exposure to LBP therapy could reverse the above alterations (p < 0.05).

CONCLUSIONS

These results demonstrated that LBP could ameliorate hyperglycemia-exacerbated cerebral ischemia/reperfusion injury via protecting the blood-brain barrier.

Proteomic characterization of spontaneously regrowing spinal cord following injury in the teleost fish Apteronotus leptorhynchus, a regeneration-competent vertebrate

In adult mammals, spontaneous repair after spinal cord injury (SCI) is severely limited. By contrast, teleost fish successfully regenerate injured axons and produce new neurons from adult neural stem cells after SCI. The molecular mechanisms underlying this high regenerative capacity are largely unknown. The present study addresses this gap by examining the temporal dynamics of proteome changes in response to SCI in the brown ghost knifefish (Apteronotus leptorhynchus). Two-dimensional difference gel electrophoresis (2D DIGE) was combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tandem mass spectrometry (MS/MS) to collect data during early (1 day), mid (10 days), and late (30 days) phases of regeneration following caudal amputation SCI. Forty-two unique proteins with significant differences in abundance between injured and intact control samples were identified. Correlation analysis uncovered six clusters of spots with similar expression patterns over time and strong conditional dependences, typically within functional families or between isoforms. Significantly regulated proteins were associated with axon development and regeneration; proliferation and morphogenesis; neuronal differentiation and re-establishment of neural connections; promotion of neuroprotection, redox homeostasis, and membrane repair; and metabolism or energy supply. Notably, at all three time points examined, significant regulation of proteins involved in inflammatory responses was absent.

Oviductal Glycoprotein 1 Promotes Hypertension by Inducing Vascular Remodeling Through an Interaction With MYH9

BACKGROUND

Hypertension is a common cardiovascular disease that is related to genetic and environmental factors, but its mechanisms remain unclear. DNA methylation, a classic epigenetic modification, not only regulates gene expression but is also susceptible to environmental factors, linking environmental factors to genetic modification. Therefore, globally screening differential genomic DNA methylation in patients with hypertension is important for investigating hypertension mechanisms.

METHODS

Differential genomic DNA methylation in patients with hypertension, individuals with prehypertension, and healthy control individuals was screened using Illumina 450K BeadChip and verified by pyrosequencing. Plasma OVGP1 (oviduct glycoprotein 1) levels were determined using an enzyme-linked immunosorbent assay. Ovgp1 transgenic and knockout mice were generated to analyze the function of OVGP1. The blood pressure levels of the mouse models were measured using the tail-cuff system and radiotelemetry methods. The role of OVGP1 in vascular remodeling was determined by vascular relaxation studies. Protein-protein interactions were investigated using a pull-down/mass spectrometry assay and verified with coimmunoprecipitation and pull-down assays.

RESULTS

We found a hypomethylated site at cg20823859 in the promoter region of OVGP1 and plasma OVGP1 levels were significantly increased in patients with hypertension. This finding indicates that OVGP1 is associated with hypertension. In Ovgp1 transgenic mice, OVGP1 overexpression caused an increase in blood pressure, dysfunctional vasoconstriction and vasodilation, remodeling of arterial walls, and increased vascular superoxide stress and inflammation, and these phenomena were exacerbated by angiotensin II infusion. In contrast, OVGP1 deficiency attenuated angiotensin II-induced vascular oxidase stress, inflammation, and collagen deposition. These findings indicate that OVGP1 is a prohypertensive factor that directly promotes vascular remodeling. Pull-down and coimmunoprecipitation assays showed that MYH9 (nonmuscle myosin heavy chain IIA) interacted with OVGP1, whereas inhibition of MYH9 attenuated OVGP1-induced hypertension and vascular remodeling.

CONCLUSIONS

Hypomethylation at cg20823859 in the promoter region of OVGP1 is associated with hypertension and induces upregulation of OVGP1. The interaction between OVGP1 and MYH9 contributes to vascular remodeling and dysfunction. Therefore, OVGP1 is a prohypertensive factor that promotes vascular remodeling by binding with MYH9.

Tight Junctions, the Key Factor in Virus-Related Disease

Tight junctions (TJs) are highly specialized membrane structural domains that hold cells together and form a continuous intercellular barrier in epithelial cells. TJs regulate paracellular permeability and participate in various cellular signaling pathways. As physical barriers, TJs can block viral entry into host cells; however, viruses use a variety of strategies to circumvent this barrier to facilitate their infection. This paper summarizes how viruses evade various barriers during infection by regulating the expression of TJs to facilitate their own entry into the organism causing infection, which will help to develop drugs targeting TJs to contain virus-related disease.

Defective VWF secretion due to the expression of MYH9-RD E1841K mutant in endothelial cells disrupts hemostasis

Mutations in MYH9, the gene encoding the heavy chain of non-muscle myosin IIa (NMII-A), cause MYH9-related disease (MYH9-RD) that is an autosomal-dominant thrombocytopenia with bleeding tendency. Previously, we showed that NMII-A in endothelial cells (ECs) is critical for hemostasis via regulating von Willebrand factor (VWF) release from Weibel-Palade bodies (WPBs). The aim of this study was to determine the role of the expression of MYH9 mutants in ECs in the pathogenesis of the MYH9-RD bleeding symptom. First, we expressed the 5 most common NMII-A mutants in ECs, and found that E1841K mutant-expressing ECs secreted less VWF than the controls in response to a cAMP signaling agonist. Then, we generated 2 knockin mouse lines, one with Myh9 E1841K in ECs and the other in megakaryocytes. Endothelium-specific E1841K mice exhibited impaired cAMP-induced VWF release and a prolonged bleeding time with normal platelets, while megakaryocyte-specific E1841K mice exhibited macrothrombocytopenia and a prolonged bleeding time with normal VWF release. Finally, we present mechanistic findings that E1841K mutation not only interferes with S1943 phosphorylation and impairs the peripheral distribution of Rab27a positive WPBs in ECs under quiescent condition, but also interferes with S1916 phosphorylation by disrupting the interaction with zyxin and CKIIα, and reduces actin framework formation around WPBs and subsequent VWF secretion under the stimulation by a cAMP agonist. Altogether, our results suggest that impaired cAMP-induced endothelial VWF secretion by E1841K mutant expression may contribute to the MYH9-RD bleeding phenotype.

The myosin II inhibitor, blebbistatin, ameliorates pulmonary endothelial barrier dysfunction in acute lung injury inducedB19 by LPS via NMMHC IIA/Wnt5a/β-catenin pathway

Acute lung injury (ALI) or its most advanced form, acute respiratory distress syndrome (ARDS), is a severe inflammatory pulmonary process triggered by varieties of pathophysiological factors, among which endothelial barrier disruption plays a critical role in the progression of ALI/ARDS. As an inhibitor of myosin II, blebbistatin inhibits endothelial barrier damage. This study aimed to investigate the effect of blebbistatin on lung endothelial barrier dysfunction in LPS induced acute lung injury and its potential mechanism. Mice were challenged with LPS (5 mg/kg) by intratracheal instillation for 6 h to disrupt the pulmonary endothelial barrier in the model group. Blebbistatin (5 mg/kg, ip) was administrated 1 h before LPS challenge. The results showed that blebbistatin could significantly attenuate LPS-induced lung injury and pulmonary endothelial barrier dysfunction. And we observed that blebbistatin inhibited the activation of NMMHC IIA/Wnt5a/β-catenin pathway in pulmonary endothelium after LPS treatment. In murine lung vascular endothelial cells (MLECs) and human umbilical vein endothelial cells (HUVECs), we further confirmed that Blebbistatin (1 μmol/L) markedly ameliorated endothelial barrier dysfunction in MLECs and HUVECs by modulating NMMHC IIA/Wnt5a/β-catenin pathway. Our data demonstrated that blebbistatin could inhibit the development of pulmonary endothelial barrier dysfunction and ALI via NMMHC IIA/Wnt5a/β-catenin signaling pathway.

Advances in brain barriers and brain fluids research in 2021: great progress in a time of adversity

This editorial highlights advances in brain barrier and brain fluid research in 2021. It covers research on components of the blood–brain barrier, neurovascular unit and brain fluid systems; how brain barriers and brain fluid systems are impacted by neurological disorders and their role in disease progression; and advances in strategies for treating such disorders.

YiQiFuMai lyophilized injection attenuates cerebral ischemic injury with inhibition of neuronal autophagy through intervention in the NMMHC IIA-actin-ATG9A interaction

BACKGROUND

YiQiFuMai lyophilized injection (YQFM) is derived from a traditional Chinese medicine prescription termed Shengmai San.YQFM is clinically applied to the treatment of cardiovascular and cerebrovascular diseases. It has been found that critical components of YQFM affect non-muscle myosin heavy chain IIA (NMMHC IIA), but its regulation in the excessive autophagy and the underlying mechanism has yet to be clarified.

PURPOSE

To evaluate whether YQFM has neuroprotective effects on cerebral ischemia/reperfusion-induced injury by inhibiting NMMHC IIA-actin-ATG9A interaction for autophagosome formation.

METHODS

The neuroprotective effects of YQFM were investigated in vivo in mice with middle cerebral artery occlusion/reperfusion (MCAO/R) (n = 6) by detecting neurological deficits, infarct volume, and histopathological changes. The NMMHC IIA-actin-ATG9A interaction was determined using immunofluorescence co-localization, co-immunoprecipitation, and proximity ligation assay. Rat pheochromocytoma (PC12) cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) were used to mimic neurons in in vitro experiments.

RESULTS

In MCAO/R model mice, YQFM (1.342 g/kg) attenuated brain ischemia/reperfusion-induced injury by regulating NMMHC IIA-actin-mediated ATG9A trafficking. YQFM (400 μg/ml) also exerted similar effects on OGD/R-induced PC12 cells. Furthermore, RNAi of NMMHC IIA weakened the NMMHC IIA-F-actin-dependent ATG9A trafficking and, therefore, attenuated the neuroprotective activities of YQFM in vitro.

CONCLUSION

These findings demonstrated that YQFM exerted neuroprotective effects by regulating the NMMHC IIA-actin-ATG9A interaction for autophagosome formation. This evidence sheds new light on the potential mechanism of YQFM in the treatment of cerebral ischemia/reperfusion.