Elevated cerebrospinal fluid levels of thrombospondin-1 correlate with adverse clinical outcome in patients with aneurysmal subarachnoid hemorrhage

Intra- and Early Post-Operative Factors Affecting Spinal Cord Ischemia in Patients Undergoing Fenestrated and Branched Endovascular Aortic Repair

Background: Spinal cord ischemia (SCI) is a severe complication after fenestrated/branched endovascular repair (f/bEVAR). The underlying causes of SCI are still under investigation. This study aimed to evaluate intra- and early post-operative parameters that may affect SCI evolution. Methods: A single-center retrospective analysis was conducted including SCI patients with complete anesthesiologic records (1 January 2011 to 31 December 2023). Values of intra-operative glucose, hemoglobin, lactate, activated clotting time (ACT), and the need for transfusion were collected. The cohort was compared to a matched cohort of non-SCI patients. Results: Fifty-one patients with SCI and complete anesthesiologic records were included (mean age: 69.8 ± 6.2 years; 39.2% male). Intra-operative glucose value < 110 mg/dL (AUC: 0.73; sensitivity 91%, specificity of 83%) and hemoglobin value > 8.5 mg/dL (AUC: 0.61; sensitivity 83%, specificity 78%) were protective for Grade 3 SCI. Twenty-three patients with SCI were matched to 23 patients without SCI. SCI patients presented significantly higher glucose levels intra-operatively (glucose mean value: SCI 150 ± 46 mg/dL vs. non-SCI: 122 ± 30 mg/dL, p = 0.005). ACT (SCI 259 ± 31 svs. non-SCI 288 ± 28 s, p = 0.001), volume input (SCI 4030 ± 1430 mL vs. non-SCI 3020 ± 113 mL, p = 0.009), and need for transfusion (SCI: 52.5% vs. 4.3%, p < 0.001) were related to SCI. Higher glucose levels were detected among patients with SCI, at 24 (SCI: 142 ± 30 mg/dL vs. non-SCI: 118 ± 26 mg/dL, p=0.004) and 48 h (SCI: 140 ± 29 mg/dL vs. non-SCI: 112 ± 20 mg/dL, p < 0.001) post-operatively. Conclusions: SCI is a multifactorial complication after f/bEVAR. Intra-operative and early post-operative glucose levels may be related to SCI evolution. Targeted glucose < 110 mg/dL may be protective for Grade 3 SCI.

DNA methylation and stroke prognosis: an epigenome-wide association study

BACKGROUND AND AIMS

Stroke is the leading cause of adult-onset disability. Although clinical factors influence stroke outcome, there is a significant variability among individuals that may be attributed to genetics and epigenetics, including DNA methylation (DNAm). We aimed to study the association between DNAm and stroke prognosis.

METHODS AND RESULTS

To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N = 316] and St. Pau [replication, N = 92]). Functional outcome was assessed using the modified Rankin Scale (mRS) at three months after stroke, being poor outcome defined as mRS > 2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the first 24 h. We searched for differentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value < 10-5 were subsequently tested in the replication cohort. We then meta-analyzed DMP results from both cohorts and used them to identify differentially methylated regions (DMRs). After doing the epigenome-wide association study, we found 29 DMPs at p-value < 10-5 and one of them was replicated: cg24391982, annotated to thrombospondin-2 (THBS2) gene (p-valuediscovery = 1.54·10-6; p-valuereplication = 9.17·10-4; p-valuemeta-analysis = 6.39·10-9). Besides, four DMRs were identified in patients with poor outcome annotated to zinc finger protein 57 homolog (ZFP57), Arachidonate 12-Lipoxygenase 12S Type (ALOX12), ABI Family Member 3 (ABI3) and Allantoicase (ALLC) genes (p-value < 1·10-9 in all cases).

DISCUSSION

Patients with poor outcome showed a DMP at THBS2 and four DMRs annotated to ZFP57, ALOX12, ABI3 and ALLC genes. This suggests an association between stroke outcome and DNAm, which may help identify new stroke recovery mechanisms.

The extracellular matrix as modifier of neuroinflammation and recovery in ischemic stroke and intracerebral hemorrhage

Stroke is the second leading cause of death worldwide and has two major subtypes: ischemic stroke and hemorrhagic stroke. Neuroinflammation is a pathological hallmark of ischemic stroke and intracerebral hemorrhage (ICH), contributing to the extent of brain injury but also in its repair. Neuroinflammation is intricately linked to the extracellular matrix (ECM), which is profoundly altered after brain injury and in aging. In the early stages after ischemic stroke and ICH, immune cells are involved in the deposition and remodeling of the ECM thereby affecting processes such as blood-brain barrier and cellular integrity. ECM components regulate leukocyte infiltration into the central nervous system, activate a variety of immune cells, and induce the elevation of matrix metalloproteinases (MMPs) after stroke. In turn, excessive MMPs may degrade ECM into components that are pro-inflammatory and injurious. Conversely, in the later stages after stroke, several ECM molecules may contribute to tissue recovery. For example, thrombospondin-1 and biglycan may promote activity of regulatory T cells, inhibit the synthesis of proinflammatory cytokines, and aid regenerative processes. We highlight these roles of the ECM in ischemic stroke and ICH and discuss their potential cellular and molecular mechanisms. Finally, we discuss therapeutics that could be considered to normalize the ECM in stroke. Our goal is to spur research on the ECM in order to improve the prognosis of ischemic stroke and ICH.

Biomarkers in aneurysmal subarachnoid hemorrhage: A short review

Poor outcomes of aneurysmal subarachnoid hemorrhage (aSAH) can be the result of the initial catastrophic event or the many acute or delayed neurological complications. Recent evidence suggests that some molecules play a critical role in both events, through some unknown pathways involved. Understanding the role of these molecules in these events could allow to improve diagnostic accuracy, guide management, and prevent long-term disability in aSAH. Here we present the studies on aSAH biomarkers present in current medical literature, highlighting their roles and main results.

Elevated MFG-E8 in CSF in the Early Stage Indicates Rapid Recovery of Mild Aneurysmal SAH Patients

Background

Aneurysmal subarachnoid hemorrhage (aSAH) can impair blood perfusion in brain tissue and cause adverse effects. Microglia, which are the inherent immune cells of the brain, significantly activate and play a role in phagocytosis, anti-inflammatory, proinflammatory, and damage repair in this process. Milk fat globule epidermal growth factor 8 (MFG-E8) is the bridging molecule of this process and mediates the activation and biological effects of microglia.

Methods

We obtained cerebrospinal fluid (CSF) from patients with aSAH at various times (the third day, seventh day, and ninth day) as well as from patients in the control cohort. MFG-E8 protein levels in CSF were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we evaluated the GCS and GOS of aSAH patients on admission and on the third day, seventh day, ninth day, and at discharge. Then, we analyzed the association between the levels of MFG-E8 and the changes in GCS and GOS.

Results

MFG-E8 expression rose in the early stage on the third day and reached equilibrium around day 7 and day 9. The levels of MFG-E8 on the third day were associated with the change in GOS on the seventh day (r = 0.644, p = 0.018) and ninth day (r = 0.572, p = 0.041) compared with admission but were not correlated with the change on day 3 or at discharge. The levels of MFG-E8 were not correlated with any change in GCS.

Conclusions

We found that aSAH resulted in an upregulation of MFG-E8 in CSF. Moreover, high MFG-E8 levels in the early stage indicated a rapid recovery of mild aSAH patients.

Proteomics-Based Identification of Diagnostic Biomarkers Related to Risk Factors and Pathogenesis of Ischemic Stroke

Ischemic stroke is caused by blood clot formation and consequent vessel blockage. Proteomic approaches provide a cost-effective alternative to current diagnostic methods, including computerized tomography (CT) scans and magnetic resonance imaging (MRI). To identify diagnostic biomarkers associated with ischemic stroke risk factors, we performed individual proteomic analysis of serum taken from 20 healthy controls and 20 ischemic stroke patients. We then performed SWATH analysis, a data-independent method, to assess quantitative changes in protein expression between the two experimental conditions. Our analysis identified several candidate protein biomarkers, 11 of which were validated by multiple reaction monitoring (MRM) analysis as novel diagnostic biomarkers associated with ischemic stroke risk factors. Our study identifies new biomarkers associated with the risk factors and pathogenesis of ischemic stroke which, to the best of our knowledge, were previously unknown. These markers may be effective in not only the diagnosis but also the prevention and management of ischemic stroke.

Crosstalk between soluble PDGF-BB and PDGFRβ promotes astrocytic activation and synaptic recovery in the hippocampus after subarachnoid hemorrhage

Platelet-derived growth factor receptor β (PDGFRβ) dynamically changes after brain injury, possibly mediating the neuroprotective role of soluble homodimers of the platelet-derived growth factor β subunit (PDGF-BB) that is secreted by microcirculation cells. The aim of this study was to determine whether binding of PDGF-BB to astrocytic PDGFRβ enhanced crosstalk among the various components of the neurovascular unit, leading to synaptic recovery after subarachnoid hemorrhage (SAH). The soluble PDGF-BB from the cerebrospinal fluid (CSF) of patients with SAH was measured. The relationship between PDGF-BB treatment and astrocytic PDGFRβ signaling was further explored in vivo and in vitro in experimental SAH models. Compared with the levels in the control samples, the PDGF-BB protein levels in the CSF of patients with SAH were significantly increased. After the generation of experimental SAH, astrocyte activation markers were markedly induced by the binding of PDGF-BB to astrocytic PDGFRβ, accompanied by improved levels of synaptic recovery and cognitive function. Soluble PDGF-BB and astrocytic PDGFRβ signaling are essential for the neuroprotective effect in the hippocampus and the coculture system in vitro after SAH that otherwise leads to cognitive dysfunction and neuronal damage.-Zhou, X., Wu, Q., Lu, Y., Zhang, X., Lv, S., Shao, J., Zhou, Y., Chen, J., Hou, L., Huang, C., Zhang, X. Crosstalk between soluble PDGF-BB and PDGFRβ promotes astrocytic activation and synaptic recovery in the hippocampus after subarachnoid hemorrhage.

Matricellular protein thrombospondin-1 in pulmonary hypertension: multiple pathways to disease

Matricellular proteins are secreted molecules that have affinities for both extracellular matrix and cell surface receptors. Through interaction with structural proteins and the cells that maintain the matrix these proteins can alter matrix strength. Matricellular proteins exert control on cell activity primarily through engagement of membrane receptors that mediate outside-in signaling. An example of this group is thrombospondin-1 (TSP1), first identified as a component of the secreted product of activated platelets. As a result, TSP1 was initially studied in relation to coagulation, growth factor signaling and angiogenesis. More recently, TSP1 has been found to alter the effects of the gaseous transmitter nitric oxide (NO). This latter capacity has provided motivation to study TSP1 in diseases associated with loss of NO signaling as observed in cardiovascular disease and pulmonary hypertension (PH). PH is characterized by progressive changes in the pulmonary vasculature leading to increased resistance to blood flow and subsequent right heart failure. Studies have linked TSP1 to pre-clinical animal models of PH and more recently to clinical PH. This review will provide analysis of the vascular and non-vascular effects of TSP1 that contribute to PH, the experimental and translational studies that support a role for TSP1 in disease promotion and frame the relevance of these findings to therapeutic strategies.

Human expression patterns: qualitative and quantitative analysis of thrombospondin-1 under physiological and pathological conditions

Thrombospondin-1 (TSP-1), a matricellular protein and one of the first endogenous anti-angiogenic molecules identified, has long been considered a potent modulator of human diseases. While the therapeutic effect of TSP-1 to suppress cancer was investigated in both research and clinical settings, the mechanisms of how TSP-1 is regulated in cancer remain elusive, and the scientific answers to the question of whether TSP-1 expressions can be utilized as diagnostic or prognostic marker for patients with cancer are largely inconsistent. Moreover, TSP-1 plays crucial functions in angiogenesis, inflammation and tissue remodelling, which are essential biological processes in the progression of many cardiovascular diseases, and therefore, its dysregulated expressions in such conditions may have therapeutic significance. Herein, we critically analysed the literature pertaining to TSP-1 expression in circulating blood and pathological tissues in various types of cancer as well as cardiovascular and inflammation-related diseases in humans. We compare the secretion rates of TSP-1 by different cancer and non-cancer cells and discuss the potential connection between the expression changes of TSP-1 and vascular endothelial growth factor (VEGF) observed in patients with cancer. Moreover, the pattern and emerging significance of TSP-1 profiles in cardiovascular disease, such as peripheral arterial disease, diabetes and other related non-cancer disorders, are highlighted. The analysis of published TSP-1 data presented in this review may have implications for the future exploration of novel TSP-1-based treatment strategies for cancer and cardiovascular-related diseases.

Levels of Interleukin-1β, Interleukin-18, and Tumor Necrosis Factor-α in Cerebrospinal Fluid of Aneurysmal Subarachnoid Hemorrhage Patients May Be Predictors of Early Brain Injury and Clinical Prognosis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe cerebrovascular accident with high morbidity and mortality. The aim of this study is to investigate the relationship between level of inflammatory cytokines in cerebrospinal fluid (CSF) of aSAH patients, the severity of aSAH, and the outcome of aSAH patients.

METHODS

aSAH patients were prospectively included and followed-up for 6 months. CSF samples were collected at 1-3, 4-6, and 7-9 days after aSAH onset. Levels of interleukin (IL)-1β, IL-18, and tumor necrosis factor-α (TNF-α) in the CSF of aSAH patients were measured by enzyme-linked immunosorbent assay.

RESULTS

Eighty-one aSAH patients were enrolled. The levels of IL-1β, IL-18 and TNF-α in the CSF were especially higher in the group of aSAH patients with cerebral edema, cerebral vasospasm, and a high grade on Hunt-Hess scale, the high World Federation of Neurological Surgeons grades, and Fisher grade (P < 0.01). Higher levels of plasma C-reactive protein in the blood were correlated with poor outcome. The areas under the receiver operating characteristic curves for the levels of inflammatory cytokines in CSF were 0.85, 0.84, and 0.95, respectively. Clinical features (age, Hunt-Hess grade, etc.) were positively correlated with poor outcomes (P < 0.05).

CONCLUSIONS

The levels of IL-1β, IL-18, and TNF-α in CSF were elevated in aSAH patients and were positively associated with cerebral edema and acute hydrocephalus. Our findings suggest that CSF inflammatory cytokines might be biomarkers to assess severity and predict outcomes.

The Roles of Thrombospondins in Hemorrhagic Stroke

Hemorrhagic stroke is a devastating cerebrovascular disease with significant morbidity and mortality worldwide. Thrombospondins (TSPs), as matricellular proteins, belong to the TSP family which is comprised of five members. All TSPs modulate a variety of cellular functions by binding to various receptors. Recently, TSPs gained attention in the area of hemorrhagic stroke, especially TSP-1. TSP-1 participates in angiogenesis, the inflammatory response, apoptosis, and fibrosis after hemorrhagic stroke through binding to various molecules including but not limited to CD36, CD47, and TGF-β. In this review, we will discuss the roles of TSPs in hemorrhagic stroke and focus primarily on TSP-1.