Neurocoagulation from a Mechanistic Point of View in the Central Nervous System

Association between coagulation activity and clinical and imaging outcomes in acute ischemic stroke patients - A sub-study of the MR CLEAN NO-IV trial

BACKGROUND

The MR CLEAN NO-IV trial showed neither superiority nor noninferiority of endovascular treatment (EVT) alone compared to intravenous thrombolysis (IVT; Alteplase) before EVT in acute ischemic stroke (AIS) patients with large vessel occlusion of the anterior circulation. Although the treatment effect is largely attributable to EVT, IVT may affect hypercoagulability during AIS.

AIMS

To investigate the association between activated coagulation and final infarct volume and clinical outcomes (modified Rankin Scale 3-6 and mortality 90 days post-EVT), and whether this effect is modified by IVT administration.

METHODS

Enzyme-linked immunosorbent assays were used to quantify activated coagulation markers (activated coagulation factor (F) XIIa-C1 esterase inhibitor (C1inh); FXIIa-antithrombin (AT), FXIa-C1inh, FXIa-AT, FIXa-AT, FXa-AT, T-AT, FVIIa-AT) in plasma samples obtained on admission (T0), 1 h post-EVT (T1) and 24 h post-EVT (T2). Multivariable regressions were performed to investigate the associations and effect modification.

RESULTS

In the total cohort of 116 patients, a significant increase at T1 was seen in FIXa-AT (p = .001), FXa-AT (p < .001), T-AT (p < .001), and FVIIa-AT (p = .012), while there was a significant increase at T2 in FXIIa-C1inh (p < .001). Similar results were seen in the IVT+EVT subgroup. The EVT alone subgroup showed a significant temporary increase at T1 in FXa-AT (p < .001) and T-AT (p = .014). Neither the enzyme:inhibitor complexes nor the interaction with IVT were significantly associated with the outcome measures.

CONCLUSION

Despite temporary significant increases in enzyme:inhibitor complexes in the IVT+EVT group, but not in the EVT alone group, there were no significant associations with final infarct volume and clinical outcomes.

Single-cell transcriptomic analysis of glioblastoma reveals pericytes contributing to the blood-brain-tumor barrier and tumor progression

The blood-brain barrier is often altered in glioblastoma (GBM) creating a blood-brain-tumor barrier (BBTB) composed of pericytes. The BBTB affects chemotherapy efficacy. However, the expression signatures of BBTB-associated pericytes remain unclear. We aimed to identify BBTB-associated pericytes in single-cell RNA sequencing data of GBM using pericyte markers, a normal brain pericyte expression signature, and functional enrichment. We identified parathyroid hormone receptor-1 (PTH1R) as a potential marker of pericytes associated with BBTB function. These pericytes interact with other cells in GBM mainly through extracellular matrix-integrin signaling pathways. Compared with normal pericytes, pericytes in GBM exhibited upregulation of several ECM genes (including collagen IV and FN1), and high expression levels of these genes were associated with a poor prognosis. Cell line experiments showed that PTH1R knockdown in pericytes increased collagen IV and FN1 expression levels. In mice models, the expression levels of PTH1R, collagen IV, and FN1 were consistent with these trends. Evans Blue leakage and IgG detection in the brain tissue suggested a negative correlation between PTH1R expression levels and blood-brain barrier function. Further, a risk model based on differentially expressed genes in PTH1R+ pericytes had predictive value for GBM, as validated using independent and in-house cohorts.

Endothelial NMMHC IIA dissociation from PAR1 activates the CREB3/ARF4 signaling in thrombin-mediated intracerebral hemorrhage

INTRODUCTION

There is an urgent need for cerebroprotective interventions to improve the suboptimal outcomes with intracerebral hemorrhage (ICH). Despite the important role of nonmuscle myosin heavy chain IIA (NMMHC IIA) in the blood-brain barrier (BBB), its function in ICH remains unclear.

OBJECTIVES

The objective of this study is to explore how NMMHC IIA functions in ICH and to evaluate the effectiveness of targeting NMMHC IIA as a treatment for ICH.

METHODS

We firstly examined the protein expression of NMMHC IIA in clinical patients and animal models with ICH. The function of NNMMHC IIA was then corroborated by using overexpress or knockdown NMMHC IIA specifically in ECs mice and pBMECs. In addition, we explored protein interacts with NMMHC IIA and signaling pathways after ICH by LC-MS/MS and transcriptomics analysis with an emphasis on the function of PAR1 and the CREB3/ARF4 signaling pathway, and validated them in three kind of animal models. To support the clinical translation of our results, we targeted NMMHC IIA to bicalutamide selected from a library of marketed drugs and examined to validate its ameliorative effect on ICH.

RESULTS

We observed an upregulation of endothelial NMMHC IIA in the brain following the onset of ICH in both patients and mice, while inhibited NMMHC ⅡA improved ICH induced by thrombin, warfarin or tissue plasminogen activator (tPA) after ischemic stroke. Mechanistically, the head domain of NMMHC IIA interacted with protease-activated receptor 1 (PAR1) at the 380-430 aa region and subsequently dissociated and activated the CREB3/ARF4 signaling pathway. We found that bicalutamide and blebbistatin could bind to NMMHC IIA and effectively protect mice from thrombin-mediated ICH.

CONCLUSION

The findings indicated that NMMHC IIA dissociated from PAR1 and activated CREB3/ARF4 pathway, which aggravated BBB damage induced by thrombin. This suggested that NMMHC IIA was a novel potential therapeutic target for BBB-related diseases.

Guanxinning Tablet Alleviates Post-Ischemic Stroke Injury Via Regulating Complement and Coagulation Cascades Pathway and Inflammatory Network Mobilization

Background

Currently, ischemic stroke (IS) continues to significantly contribute to functional deterioration and reduced life quality. Regrettably, the choice of neuro-rehabilitation interventions to enhance post-IS outcomes is limited. Guanxinning tablet (GXNT), a multi-component medicine composed of Danshen and Chuanxiong, has demonstrated neuroprotective potential against ischemic brain injury and diabetic encephalopathy. However, the therapeutic impact of GXNT on post-IS functional outcomes and pathological injury, as well as the underlying molecular mechanisms and anti-IS active substances, remain unclear.

Methods

To answer the above questions, neurological and behavioral assessment, cerebral lesions, and blood-brain barrier (BBB) integrity were combined to comprehensively investigate GXNT's pharmacodynamic effects against post-IS injury. The possible molecular mechanisms were revealed through transcriptome sequencing coupled with experimental verification. Furthermore, the brain tissue distribution of main components in GXNT, behavioral changes of IS zebrafish, and molecular docking were integrated to identify the anti-IS active compounds.

Results

Treatment with GXNT significantly mitigated the functional deficits, cerebral cortex lesions, and BBB disruption following IS. Transcriptome sequencing and bioinformatics analysis suggested that complement and coagulation cascades as well as inflammation might play crucial roles in the GXNT's therapeutic effects. Molecular biology experiments indicated that GXNT administration effectively normalized the abnormal expression of mRNA and protein levels of key targets related to complement and coagulation cascades (eg C3 and F7) and inflammation (eg MMP3 and MMP9) in the impaired cortical samples of IS mice. The locomotor promotion in IS zebrafish as well as favorable affinity with key proteins (C3, F7, and MMP9) highlighted anti-IS activities of brain-permeating constituents (senkyunolide I and protocatechuic acid) of GXNT.

Conclusion

Taken together, these intriguing findings indicate that GXNT intervention exerts a beneficial effect against post-IS injury via regulating the complement and coagulation cascades pathway and mobilizing inflammatory network. Senkyunolide I and protocatechuic acid show promise as anti-IS active compounds.

Direct neuronal protection by the protease-activated receptor PAR4 antagonist ML354 after experimental stroke in mice

BACKGROUND AND PURPOSE

Thrombo-inflammation is a key feature of stroke pathophysiology and provides multiple candidate drug targets. Thrombin exerts coagulation-independent actions via protease-activated receptors (PAR), of which PAR1 has been implicated in stroke-associated neuroinflammation. The role of PAR4 in this context is less clear. This study examined if the selective PAR4 antagonist ML354 provides neuroprotection in experimental stroke and explored the underlying mechanisms.

EXPERIMENTAL APPROACH

Mouse primary cortical neurons were exposed to oxygen-glucose deprivation (OGD) and simulated reperfusion ± ML354. For comparison, functional Ca2+-imaging was performed upon acute stimulation with a PAR4 activating peptide or glutamate. Male mice underwent sham operation or transient middle cerebral artery occlusion (tMCAO), with ML354 or vehicle treatment beginning at recanalization. A subset of mice received a platelet-depleting antibody. Stroke size and functional outcomes were assessed. Abundance of target genes, proteins, and cell markers was determined in cultured cells and tissues by qPCR, immunoblotting, and immunofluorescence.

KEY RESULTS

Stroke up-regulated PAR4 expression in cortical neurons in vitro and in vivo. OGD augments spontaneous and PAR4-mediated neuronal activity; ML354 suppresses OGD-induced neuronal excitotoxicity and apoptosis. ML354 applied in vivo after tMCAO reduced infarct size, apoptotic markers, macrophage accumulation, and interleukin-1β expression. Platelet depletion did not affect infarct size in mice with tMCAO ± ML354.

CONCLUSIONS AND IMPLICATIONS

Selective PAR4 inhibition during reperfusion improves infarct size and neurological function after experimental stroke by blunting neuronal excitability, apoptosis, and local inflammation. PAR4 antagonists may provide additional neuroprotective benefits in patients with acute stroke beyond their canonical antiplatelet action.

The predictive value of serum F-actin on the severity and early neurological deterioration of acute ischemic stroke: Predictive value of F-actin in stroke

BACKGROUND

F-actin is involved in the progression of ischemic stroke and is associated with the disruption of the blood-brain barrier. In this article, we evaluated serum F-actin as a biomarker in stroke severity and early neurological deterioration (END) in acute ischemic stroke.

METHODS

In this study, serum F-actin was measured in consecutively collected 140 AIS patients and 144 healthy controls matched in gender and age by ELISA. Early neurological deterioration (END) was defined as the deterioration of neurological dysfunction within 72 hours of admission, with an increase of ≥ 4 points in the NIHSS score. Severe stroke was defined as a NIHSS score>8 at admission.

RESULTS

The serum F-actin level in AIS was significantly higher than healthy controls (p = 0.041). In large-artery atherosclerosis stroke and cardioembolic stroke, serum F-actin were significantly higher than that in small artery occlusion stroke (padjust = 0.019, padjust < 0.001, respectively).F-actin level above the critical value (>1.37 µg/L) was significantly associated with severe stroke (OR, 3.015; 95 %CI, 1.014-8.963; p = 0.047) . In addition, elevated level of F-actin was significantly associated with END (OR, 1.323; 95 % CI, 1.001-1.747, p = 0.049). When the level of F-actin was above the critical value (>2.17 µg/L), its association with END remained significant (OR, 6.303; 95 %CI, 2.160-18.394; p < 0.001) .

CONCLUSION

F-actin is an important blood biomarker in the early stage of AIS, and high levels of F-actin are valuable in determining the severity of stroke and predicting early neurological deterioration.

Exploring the "gene-metabolite" network of ischemic stroke with blood stasis and toxin syndrome by integrated transcriptomics and metabolomics strategy

A research model combining a disease and syndrome can provide new ideas for the treatment of ischemic stroke. In the field of traditional Chinese medicine, blood stasis and toxin (BST) syndrome is considered an important syndrome seen in patients with ischemic stroke (IS). However, the biological basis of IS-BST syndrome is currently not well understood. Therefore, this study aimed to explore the biological mechanism of IS-BST syndrome. This study is divided into two parts: (1) establishment of an animal model of ischemic stroke disease and an animal model of BST syndrome in ischemic stroke; (2) use of omics methods to identify differentially expressed genes and metabolites in the models. We used middle cerebral artery occlusion (MCAO) surgery to establish the disease model, and utilized carrageenan combined with active dry yeast and MCAO surgery to construct the IS-BST syndrome model. Next, we used transcriptomics and metabolomics methods to explore the differential genes and metabolites in the disease model and IS-BST syndrome model. It is found that the IS-BST syndrome model exhibited more prominent characteristics of IS disease and syndrome features. Both the disease model and the IS-BST syndrome model share some common biological processes, such as thrombus formation, inflammatory response, purine metabolism, sphingolipid metabolism, and so on. Results of the "gene-metabolite" network revealed that the IS-BST syndrome model exhibited more pronounced features of complement-coagulation cascade reactions and amino acid metabolism disorders. Additionally, the "F2 (thrombin)-NMDAR/glutamate" pathway was coupled with the formation process of the blood stasis and toxin syndrome. This study reveals the intricate mechanism of IS-BST syndrome, offering a successful model for investigating the combination of disease and syndrome.

Sustainable inflammatory activation following spinal cord injury is driven by thrombin-mediated dynamic expression of astrocytic chemokines

Acute spinal cord injury (SCI) always results in sustainable recruitment of inflammatory cells driven by sequentially generated chemokines, thereby eliciting excessive neuroinflammation. However, the underlying mechanism of temporally produced chemokines remains elusive. Reactive astrocytes are known to be the main sources of chemokines at the lesion site, which can be immediately activated by thrombin following SCI. In the present study, SCI was shown to induce a sequential production of chemokines CCL2 and CCL5 from astrocytes, which were associated with a persistent infiltration of macrophages/microglia. The rapidly induced CCL2 and later induced CCL5 from astrocytes were regulated by thrombin at the damaged tissues. Investigation of the regulatory mechanism revealed that thrombin facilitated astrocytic CCL2 production through activation of ERK/JNK/NFκB pathway, whereas promoted CCL5 production through PLCβ3/NFκB and ERK/JNK/NFκB signal pathway. Inhibition of thrombin activity significantly decreased production of astrocytic CCL2 and CCL5, and reduced the accumulation of macrophages/microglia at the lesion site. Accordingly, the locomotor function of rats was remarkably improved. The present study has provided a new regulatory mechanism on thrombin-mediated sequential production of astrocytic chemokines, which might be beneficial for clinical therapy of CNS neuroinflammation.

DIA-based technology explores hub pathways and biomarkers of neurological recovery in ischemic stroke after rehabilitation

Objective

Ischemic stroke (IS) is a common disease that causes severe and long-term neurological disability in people worldwide. Although rehabilitation is indispensable to promote neurological recovery in ischemic stroke, it is limited to providing a timely and efficient reference for developing and adjusting treatment strategies because neurological assessment after stroke treatment is mostly performed using scales and imaging. Therefore, there is an urgent need to find biomarkers that can help us evaluate and optimize the treatment plan.

Methods

We used data-independent acquisition (DIA) technology to screen differentially expressed proteins (DEPs) before and after ischemic stroke rehabilitation treatment, and then performed Gene Ontology (GO) and pathway enrichment analysis of DEPs using bioinformatics tools such as KEGG pathway and Reactome. In addition, the protein-protein interaction (PPI) network and modularity analysis of DEPs were integrated to identify the hub proteins (genes) and hub signaling pathways for neurological recovery in ischemic stroke. PRM-targeted proteomics was also used to validate some of the screened proteins of interest.

Results

Analyzing the serum protein expression profiles before and after rehabilitation, we identified 22 DEPs that were upregulated and downregulated each. Through GO and pathway enrichment analysis and subsequent PPI network analysis constructed using STRING data and subsequent Cytoscape MCODE analysis, we identified that complement-related pathways, lipoprotein-related functions and effects, thrombosis and hemostasis, coronavirus disease (COVID-19), and inflammatory and immune pathways are the major pathways involved in the improvement of neurological function after stroke rehabilitation.

Conclusion

Complement-related pathways, lipoprotein-related functions and effects, thrombosis and hemostasis, coronavirus disease (COVID-19), and inflammation and immunity pathways are not only key pathways in the pathogenesis of ischemic stroke but also the main pathways of action of rehabilitation therapy. In addition, IGHA1, LRG1, IGHV3-64D, and CP are upregulated in patients with ischemic stroke and downregulated after rehabilitation, which may be used as biomarkers to monitor neurological impairment and recovery after stroke.

Understanding COVID-19-associated coagulopathy

COVID-19-associated coagulopathy (CAC) is a life-threatening complication of SARS-CoV-2 infection. However, the underlying cellular and molecular mechanisms driving this condition are unclear. Evidence supports the concept that CAC involves complex interactions between the innate immune response, the coagulation and fibrinolytic pathways, and the vascular endothelium, resulting in a procoagulant condition. Understanding of the pathogenesis of this condition at the genomic, molecular and cellular levels is needed in order to mitigate thrombosis formation in at-risk patients. In this Perspective, we categorize our current understanding of CAC into three main pathological mechanisms: first, vascular endothelial cell dysfunction; second, a hyper-inflammatory immune response; and last, hypercoagulability. Furthermore, we pose key questions and identify research gaps that need to be addressed to better understand CAC, facilitate improved diagnostics and aid in therapeutic development. Finally, we consider the suitability of different animal models to study CAC.