Monocyte Chemotactic Protein-1-Interleukin-6-Osteopontin Pathway of Intra-Aneurysmal Tissue Healing

Identification of Urine Metabolic Markers of Stroke Risk Using Untargeted Nuclear Magnetic Resonance Analysis

Stroke remains the second leading cause of mortality worldwide, and the third leading cause of death and morbidity combined, affecting more than 12 million people every year. Stroke pathophysiology results from complex interactions of several risk factors related to age, family history, gender, lifestyle, and the presence of cardiovascular and metabolic diseases. Despite all the evidence, it is not possible to fully prevent stroke onset. In recent years, there has been an exploration of innovative methodologies for metabolite analysis aimed at identifying novel stroke biomarkers. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopy, we investigated small molecule variations in urine across different stages of stroke risk. The Framingham Stroke Risk Score was used in people over 63 years of age living in long-term care facilities (LTCFs) to calculate the probability of suffering a stroke: low stroke risk (LSR, control), moderate stroke risk (MSR), and high stroke risk (HSR). Univariate statistical analysis showed that urinary 4-hydroxyphenylacetate levels increased while glycolate levels decreased across the different stroke risk groups, from the LSR to the HSR groups. Trimethylamine N-oxide (TMAO) had average concentration values that were significantly higher in elderly people in the HSR group, while trigonelline levels were significantly lower in the MSR group. These metabolic markers can be used for early detection and to differentiate stages of stroke risk more efficiently.

The landscape of angiogenesis and inflammatory factors in eyes with myopic choroidal neovascularization before and after anti-VEGF injection

INTRODUCTION

To investigate the levels of angiogenesis and inflammatory cytokines in individuals with myopic choroidal neovascularization (mCNV) and the changes in these factors following intravitreal anti-VEGF injection.

METHODS

Aqueous humor samples were gathered from eyes with mCNV, those with single macular bleeding (SMB) without mCNV in highly myopic eyes, and those with age-related cataracts. Using a multiplex bead immunoassay, we analyzed 28 angiogenesis and inflammatory factors in the aqueous humor. Furthermore, clinical data were documented for correlation analysis.

RESULTS

In this study, the levels of vascular endothelial growth factor A (VEGF-A), interleukin 8 (IL-8), and fibroblast growth factors 1 (FGF-1) were significantly elevated in mCNV compared to SMB eyes (p < 0.05). Their odds ratios for mCNV occurrence were 1.05, 3.45, and 2.64, respectively. Hepatocyte growth factor (HGF) and VEGF-C were notably higher in mCNV than in cataract patients (p < 0.05), and VEGF-C correlated to the degree of myopic atrophic maculopathy (p = 0.024). Axial length exhibited a negative correlation with VEGF-A and positive correlations with VEGF-C, HGF, and MCP-1 (p < 0.01). Following anti-VEGF treatment, a reduction in VEGF-A, endothelin-1, and FGF-2 was noted in mCNV patients (p < 0.05), but MCP-1 levels increased.

CONCLUSION

Our findings highlight the predominant role of angiogenesis and inflammation factors in mCNV pathogenesis. VEGF-C's correlation with axial length and atrophy suggests its involvement in the process of myopic atrophic maculopathy.

Inactivation of a non-canonical gp130 signaling arm attenuates chronic systemic inflammation and multimorbidity induced by a high-fat diet

Interleukin-6 (IL-6) is a major pro-inflammatory cytokine for which the levels in plasma demonstrate a robust correlation with age and body mass index (BMI) as part of the senescence-associated secretory phenotype. IL-6 cytokines also play a crucial role in metabolic homeostasis and regenerative processes, primarily via the canonical STAT3 pathway. Thus, selective modulation of IL-6 signaling may offer a unique opportunity for therapeutic interventions. Recently, we discovered that a non-canonical signaling pathway downstream of tyrosine (Y) 814 within the intracellular domain of gp130, the IL-6 co-receptor, is responsible for the recruitment and activation of SRC family of kinases (SFK). Mice with constitutive genetic inactivation of gp130 Y814 (F814 mice) show accelerated resolution of inflammatory response and superior regenerative outcomes in skin wound healing and posttraumatic models of osteoarthritis. The current study was designed to explore if selective genetic or pharmacological inhibition of the non-canonical gp130-Y814/SFK signaling reduces systemic chronic inflammation and multimorbidity in a high-fat diet (HFD)-induced model of accelerated aging. F814 mice showed significantly reduced inflammatory response to HFD in adipose and liver tissue, with significantly reduced levels of systemic inflammation compared to wild type mice. F814 mice were also protected from HFD-induced bone loss and cartilage degeneration. Pharmacological inhibition of gp130-Y814/SFK in mice on HFD mirrored the effects observed in F814 mice on HFD; furthermore, this pharmacological treatment also demonstrated a marked increase in physical activity levels and protective effects against inflammation-associated suppression of neurogenesis in the brain tissue compared to the control group. These findings suggest that selective inhibition of SFK signaling downstream of gp130 receptor represents a promising strategy to alleviate systemic chronic inflammation. Increased degenerative changes and tissue senescence are inevitable in obese and aged organisms, but we demonstrated that the systemic response and inflammation-associated multi-morbidity can be therapeutically mitigated.

Peripheral macrophages in the development and progression of structural cerebrovascular pathologies

The human cerebrovascular system is responsible for maintaining neural function through oxygenation, nutrient supply, filtration of toxins, and additional specialized tasks. While the cerebrovascular system has resilience imparted by elaborate redundant collateral circulation from supportive tertiary structures, it is not infallible, and is susceptible to developing structural vascular abnormalities. The causes of this class of structural cerebrovascular diseases can be broadly categorized as 1) intrinsic developmental diseases resulting from genetic or other underlying aberrations (arteriovenous malformations and cavernous malformations) or 2) extrinsic acquired diseases that cause compensatory mechanisms to drive vascular remodeling (aneurysms and arteriovenous fistulae). Cerebrovascular diseases of both types pose significant risks to patients, in some cases leading to death or disability. The drivers of such diseases are extensive, yet inflammation is intimately tied to all of their progressions. Central to this inflammatory hypothesis is the role of peripheral macrophages; targeting this critical cell type may lead to diagnostic and therapeutic advancement in this area. Here, we comprehensively review the role that peripheral macrophages play in cerebrovascular pathogenesis, provide a schema through which macrophage behavior can be understood in cerebrovascular pathologies, and describe emerging diagnostic and therapeutic avenues in this area.

Topographic distribution of inflammation factors in a healing aneurysm

BACKGROUND

Healing of intracranial aneurysms following endovascular treatment relies on the organization of early thrombus into mature scar tissue and neointima formation. Activation and deactivation of the inflammation cascade plays an important role in this process. In addition to timely evolution, its topographic distribution is hypothesized to be crucial for successful aneurysm healing.

METHODS

Decellularized saccular sidewall aneurysms were created in Lewis rats and coiled. At follow-up (after 3 days (n = 16); 7 days (n = 19); 21 days (n = 8)), aneurysms were harvested and assessed for healing status. In situ hybridization was performed for soluble inflammatory markers (IL6, MMP2, MMP9, TNF-α, FGF23, VEGF), and immunohistochemical analysis to visualize inflammatory cells (CD45, CD3, CD20, CD31, CD163, HLA-DR). These markers were specifically documented for five regions of interest: aneurysm neck, dome, neointima, thrombus, and adjacent vessel wall.

RESULTS

Coiled aneurysms showed enhanced patterns of thrombus organization and neointima formation, whereas those without treatment demonstrated heterogeneous patterns of thrombosis, thrombus recanalization, and aneurysm growth (p = 0.02). In coiled aneurysms, inflammation markers tended to accumulate inside the thrombus and in the neointima (p < 0.001). Endothelial cells accumulated directly in the neointima (p < 0.0001), and their presence was associated with complete aneurysm healing.

CONCLUSION

The presence of proinflammatory cells plays a crucial role in aneurysm remodeling after coiling. Whereas thrombus organization is hallmarked by a pronounced intra-thrombotic inflammatory reaction, neointima maturation is characterized by direct invasion of endothelial cells. Knowledge concerning topographic distribution of regenerative inflammatory processes may pave the way for future treatment modalities which enhance aneurysm healing after endovascular therapy.

A review of technological innovations leading to modern endovascular brain aneurysm treatment

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

Animal model contributes to the development of intracranial aneurysm: A bibliometric analysis

Introduction

Studies on intracranial aneurysms (IAs) using animal models have evolved for decades. This study aimed to analyze major contributors and trends in IA-related animal research using bibliometric analysis.

Methods

IA-related animal studies were retrieved from the Web of Science database. Microsoft Excel 2010, GraphPad Prism 6, VOSviewer, and CiteSpace were used to collect and analyze the characteristics of this field.

Results

A total of 273 publications were retrieved. All publications were published between 1976 and 2021, and the peak publication year is 2019. Rat model were used in most of the publications, followed by mice and rabbits. Japan (35.5%), the United States (30.0%), and China (20.1%) were the top three most prolific countries. Although China ranks third in the number of publications, it still lacks high-quality articles and influential institutions. Stroke was the most prolific journal that accepted publications related to IA research using animal models. Circulation has the highest impact factor with IA-related animal studies. Hashimoto N contributed the largest number of articles. Meng hui journal published the first and second highest cited publications. The keywords “subarachnoid hemorrhage,” “macrophage,” “rupture,” “mice,” “elastase,” “gene,” “protein,” “proliferation,” and “risk factors” might be a new trend for studying IA-related animal research.

Conclusions

Japan and the Unites States contributed the most to IA–related animal studies, in terms of both researchers and institutions. Although China ranks third in terms of the number of publications, it should strengthen the quality of its publications. Researchers should pay attention to the latest progress of Stroke, Journal of Neurosurgery, Neurosurgery, and Circulation for their high-quality IA-related animal studies. Using animal IA models, especially mice, to investigate the molecular mechanisms of IA may be the frontier topic now and in future.

Combination release of chemokines from coated coils to target aneurysm healing

BACKGROUND

Monocyte chemoattractant protein 1 (MCP-1) and osteopontin (OPN) have been identified separately as key mediators of the aneurysm healing process following coil embolization in the rodent model. The ability of protein coated coils to accelerate this process is currently unknown.To create coils coated with both MCP-1 and OPN to target aneurysm healing.

METHODS

We uses a polymer (poly(glycolide-co-caprolactone)) (Rao pharmaceuticals) (CG910) to test whether coils could be dual coated with active proteins with sequential reliable release. Coils were coated with poly-DL-lactic glycolic acid (PLGA), CG910, and subsequently dipped with protein OPN (inner layer for delayed release) and MCP-1 (outer layer for initial release). Release assays were used to measure protein elution from coils over time. To test in vivo feasibility, coated coils were implanted into carotid aneurysms to determine the effect on aneurysm healing.

RESULTS

The in vitro protein release assay demonstrated, a significant amount of OPN and MCP-1 release within 2 days. Using a 200 µg/µL solution of MCP-1 in phosphate-buffered saline, we showed that CG910 coated coils provide effective release of MCP over time. In the carotid aneurysm model, MCP-1 and OPN coated coils significantly increased tissue ingrowth (74% and 80%) compared with PLGA and CG910 coated coils alone (58% and 53%). To determine synergistic impact of dual coating, we measured ingrowth for MCP-1/OPN coils (63%) as well as overlap coefficients for NOX4 and NFκB with CD31.

CONCLUSIONS

This study demonstrates that MCP-1 and OPN coated coils are viable and may promote early aneurysm healing. Dual coated coils may have synergistic benefit given different location of protein interaction measured in vivo. Further work is warranted.

Potential Protein Blood-Based Biomarkers in Different Types of Dementia: A Therapeutic Overview

Abstract:

Biomarkers capable of identifying and distinguishing types of dementia such as Alzheimer's disease (AD), Parkinson's disease dementia (PDD), Lewy body dementia (LBD), and frontotemporal dementia (FTD) have been become increasingly relentless. Studies of possible biomarker proteins in the blood that can help formulate new diagnostic proposals and therapeutic visions of different types of dementia are needed. However, due to several limitations of these biomarkers, especially in discerning dementia, their clinical applications are still undetermined. Thus, the updating of biomarker blood proteins that can help in the diagnosis and discrimination of these main dementia conditions is essential to enable new pharmacological and clinical management strategies, with specificities for each type of dementia. To review the literature concerning protein blood-based AD and non-AD biomarkers as new pharmacological targets and/or therapeutic strategies. Recent findings for protein-based AD, PDD, LBD, and FTD biomarkers are focused on in this review. Protein biomarkers were classified according to the pathophysiology of the dementia types. The diagnosis and distinction of dementia through protein biomarkers is still a challenge. The lack of exclusive biomarkers for each type of dementia highlights the need for further studies in this field. Only after this, blood biomarkers may have a valid use in clinical practice as they are promising to help in diagnosis and in the differentiation of diseases.

Macrophage activation in response to shape memory polymer foam-coated aneurysm occlusion devices

Brain aneurysms can be treated with embolic coils using minimally invasive approaches. It is advantageous to modulate the biologic response of platinum embolic coils. Our previous studies demonstrated that shape memory polymer (SMP) foam coated embolization coils (FCC) devices demonstrate enhanced healing responses in animal models compared with standard bare platinum coil (BPC) devices. Macrophages are the most prevalent immune cell type that coordinate the greater immune response to implanted materials. Hence, we hypothesized that the highly porous SMP foam coatings on embolic coils activate a pro-regenerative healing phenotype. To test this hypothesis, we analyzed the number and type of infiltrating macrophages in FCC or BPC devices implanted in a rabbit elastase aneurysm model. FCC devices elicited a great number of infiltration macrophages, skewed significantly to a pro-regenerative M2-like phenotype 90 days following implantation. We devised an in vitro assay, where monocyte-derived macrophages were placed in close association with FCC or BPC devices for 6-72 h. Macrophages encountering SMP FCC-devices demonstrated highly mixed activation phenotypes at 6 h, heavily skewing toward an M2-like phenotype by 72 h, compared with macrophages encountering BPC devices. Macrophage activation was evaluated using gene expression analysis, and secreted cytokine evaluation. Together, our results demonstrate that FCC devices promoted a pro-regenerative macrophage activation phenotype, compared with BPC devices. Our in vitro findings corroborate with in vivo observations that SMP-based modification of embolic coils can promote better healing of the aneurysm site, by sustaining a pro-healing macrophage phenotype.

The Evolution of Endovascular Therapy for Intracranial Aneurysms: Historical Perspective and Next Frontiers

The history of cerebral aneurysm treatment has a rich and storied past with multiple notable luminaries contributing insights. The modern era has transitioned from primarily clip ligation to increasing use of endovascular therapy. Even more recently, the use of intrasaccular flow diverters has been introduced for the treatment of wide necked aneurysms. The field is continuing to transform, and bioactive coils and stents have resurfaced as promising adjuvants to promote aneurysm healing. Advanced imaging modalities are being developed that could further advance the endovascular arsenal and allow for porous memory polymer devices to enter the field. This focused review highlights notable historic contributions and advances to the point of futuristic technology that is actively being developed.

RIPK3-Dependent Necroptosis Activates MCP-1-Mediated Inflammation in Mice after Intracerebral Hemorrhage

BACKGROUND

Recent studies have reported that receptor-interacting protein kinase 3 (RIPK3)-dependent necroptosis is related to the pathological process of intracerebral hemorrhage (ICH). Some studies support the view that inhibiting necroptosis is a key mechanism preventing inflammation. Inflammation is a crucial factor contributing to neurological injuries and unfavorable outcomes after ICH. The aim of this study was to clarify the association between necroptosis and monocyte chemoattractant protein-1 (MCP-1)-mediated inflammation and identify a new target for the treatment of ICH.

METHODS

An ICH model was established in C57BL/6 mice by injecting collagenase IV into the right basal ganglia. The RIPK3 inhibitor GSK872 was administered through intraventricular injection. Then, we assessed brain edema and neurobehavioral function. Western blotting was employed to detect changes in RIPK3, phospho-mixed lineage kinase domain-like protein (p-MLKL), MCP-1, phospho-c-Jun N-terminal kinase (p-JNK) and interleukin 6 (IL-6) levels in the brain tissue. The localization of RIPK3 and MCP-1 was observed using immunofluorescence staining. Co-immunoprecipitation was performed to determine the interaction between RIPK3 and MCP-1.

RESULTS

Compared with the sham group, the levels of RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 were increased post-ICH. GSK872 pretreatment significantly reduced RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 expression, accompanied by mitigated cerebral edema and neurobehavioral defects. RIPK3 and MCP-1 colocalized in the perinuclear region after ICH. We detected the formation of the RIPK3-MCP-1 complex in ICH brain tissue.

CONCLUSIONS

There exerted an association between RIPK3 and MCP-1. The inhibition of RIPK3 alleviated MCP-1-mediated inflammation following ICH.

Inflammatory cytokines levels in aqueous humour and surgical outcomes of trabeculectomy in patients with prior acute primary angle closure

PURPOSE

To quantify the levels of three inflammatory cytokines in the aqueous humour of patients with prior acute primary angle closure (APAC) and investigate their correlation with surgical outcomes of trabeculectomy.

METHODS

In this prospective cohort study, aqueous humour samples were collected from 44 prior APAC eyes. Analyte concentrations of monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) were measured using multiplexed immunoassay kits. Intraocular pressure was measured using Goldmann application tonometry.

RESULTS

Forty-four prior APAC eyes were followed up for 24 months after trabeculectomy and divided into success and failure groups according to surgical outcomes. Monocyte chemoattractant protein-1 (MCP-1) levels in the aqueous humour were significantly higher in the failure group (p = 0.0118). Univariate and multivariate analyses showed that MCP-1 level was a significant risk factor for trabeculectomy outcomes (univariate analysis: p = 0.016, odds ratio = 14.538; multivariate analysis: p = 0.023, odds ratio = 13.718). When prior APAC eyes were divided according to MCP-1 levels, the overall success rate was significantly higher in eyes with low MCP-1 levels than eyes with high MCP-1 levels (p = 0.0249).

CONCLUSION

In prior APAC patients, the MCP-1 level in the aqueous humour predicts trabeculectomy results. Therefore, modulation of MCP-1 expression may have potential clinical applications after filtration surgery.

Epigenetic landscapes of intracranial aneurysm risk haplotypes implicate enhancer function of endothelial cells and fibroblasts in dysregulated gene expression

BACKGROUND

Genome-wide association studies have identified many single nucleotide polymorphisms (SNPs) associated with increased risk for intracranial aneurysm (IA). However, how such variants affect gene expression within IA is poorly understood. We used publicly-available ChIP-Seq data to study chromatin landscapes surrounding risk loci to determine whether IA-associated SNPs affect functional elements that regulate gene expression in cell types comprising IA tissue.

METHODS

We mapped 16 significant IA-associated SNPs to linkage disequilibrium (LD) blocks within human genome. Using ChIP-Seq data, we examined these regions for presence of H3K4me1, H3K27ac, and H3K9ac histone marks (typically associated with latent/active enhancers). This analysis was conducted in several cell types that are present in IA tissue (endothelial cells, smooth muscle cells, fibroblasts, macrophages, monocytes, neutrophils, T cells, B cells, NK cells). In cell types with significant histone enrichment, we used HiC data to investigate topologically associated domains (TADs) encompassing the LD blocks to identify genes that may be affected by IA-associated variants. Bioinformatics were performed to determine the biological significance of these genes. Genes within HiC-defined TADs were also compared to differentially expressed genes from RNA-seq/microarray studies of IA tissues.

RESULTS

We found that endothelial cells and fibroblasts, rather than smooth muscle or immune cells, have significant enrichment for enhancer marks on IA risk haplotypes (p < 0.05). Bioinformatics demonstrated that genes within TADs subsuming these regions are associated with structural extracellular matrix components and enzymatic activity. The majority of histone marked TADs (83% fibroblasts [IMR90], 77% HUVEC) encompassed at least one differentially expressed gene from IA tissue studies.

CONCLUSIONS

These findings provide evidence that genetic variants associated with IA risk act on endothelial cells and fibroblasts. There is strong circumstantial evidence that this may be mediated through altered enhancer function, as genes in TADs encompassing enhancer marks have also been shown to be differentially expressed in IA tissue. These genes are largely related to organization and regulation of the extracellular matrix. This study builds upon our previous (Poppenberg et al., BMC Med Genomics, 2019) by including a more diverse set of data from additional cell types and by identifying potential affected genes (i.e. those in TADs).

Interleukin 6 and Aneurysmal Subarachnoid Hemorrhage. A Narrative Review

Interleukin 6 (IL-6) is a prominent proinflammatory cytokine. Neuroinflammation in general, and IL-6 signaling in particular, appear to play a major role in the pathobiology and pathophysiology of aneurysm formation and aneurysmal subarachnoid hemorrhage (SAH). Most importantly, elevated IL-6 CSF (rather than serum) levels appear to correlate with delayed cerebral ischemia (DCI, “vasospasm”) and secondary (“vasospastic”) infarctions. IL-6 CSF levels may also reflect other forms of injury to the brain following SAH, i.e., early brain damage and septic complications of SAH and aneurysm treatment. This would explain why many researchers have found an association between IL-6 levels and patient outcomes. These findings clearly suggest CSF IL-6 as a candidate biomarker in SAH patients. However, at this point, discrepant findings in variable study settings, as well as timing and other issues, e.g., defining proper clinical endpoints (i.e., secondary clinical deterioration vs. angiographic vasospasm vs. secondary vasospastic infarct) do not allow for its routine use. It is also tempting to speculate about potential therapeutic measures targeting elevated IL-6 CSF levels and neuroinflammation in SAH patients. Corticosteroids and anti-platelet drugs are indeed used in many SAH cases (not necessarily with the intention to interfere with detrimental inflammatory signaling), however, no convincing benefit has been demonstrated yet. The lack of a robust clinical perspective against the background of a relatively large body of data linking IL-6 and neuroinflammation with the pathophysiology of SAH is somewhat disappointing. One underlying reason might be that most relevant studies only report correlative data. The specific molecular pathways behind elevated IL-6 levels in SAH patients and their various interactions still remain to be delineated. We are optimistic that future research in this field will result in a better understanding of the role of neuroinflammation in the pathophysiology of SAH, which in turn, will translate into the identification of suitable biomarkers and even potential therapeutic targets.

Plasma osteopontin as a biomarker of Alzheimer's disease and vascular cognitive impairment

Cerebrovascular disease (CeVD) and neurodegenerative dementia such as Alzheimer’s disease (AD) are frequently associated comorbidities in the elderly, sharing common risk factors and pathophysiological mechanisms including neuroinflammation. Osteopontin (OPN) is an inflammatory marker found upregulated in vascular diseases as well as in AD. However, its involvement in vascular dementia (VaD) and pre-dementia stages, namely cognitive impairment no dementia (CIND), both of which fall under the spectrum of vascular cognitive impairment (VCI), has yet to be examined. Its correlations with inflammatory cytokines in cognitive impairment also await investigation. 80 subjects with no cognitive impairment (NCI), 160 with CIND and 144 with dementia were included in a cross-sectional study on a Singapore-based memory clinic cohort. All subjects underwent comprehensive clinical, neuropsychological and brain neuroimaging assessments, together with clinical diagnoses based on established criteria. Blood samples were collected and OPN as well as inflammatory cytokines interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF) were measured using immunoassays. Multivariate regression analyses showed significant associations between increased OPN and VCI groups, namely CIND with CeVD, AD with CeVD and VaD. Interestingly, higher OPN was also significantly associated with AD even in the absence of CeVD. We further showed that increased OPN significantly associated with neuroimaging markers of CeVD and neurodegeneration, including cortical infarcts, lacunes, white matter hyperintensities and brain atrophy. OPN also correlated with elevated levels of IL-6, IL-8 and TNF. Our findings suggest that OPN may play a role in both VCI and neurodegenerative dementias. Further longitudinal analyses are needed to assess the prognostic utility of OPN in disease prediction and monitoring.

Secreted Phosphoprotein 1 Expression in Retinal Mononuclear Phagocytes Links Murine to Human Choroidal Neovascularization

Age-related macular degeneration (AMD) represents the most common cause of blindness in the elderly in the Western world. An impairment of the outer blood-retina barrier and a localized inflammatory microenvironment cause sprouting of choroidal neovascular membranes (CNV) in neovascular AMD that are in intimate contact with surrounding myeloid cells, such as retinal microglia, and ultimately lead to visual impairment. The discovery of novel target molecules to interfere with angiogenesis and inflammation is vital for future treatment approaches in AMD patients. To explore the transcriptional profile and the function of retinal microglia at sites of CNV, we performed a comprehensive RNA-seq analysis of retinal microglia in the mouse model of laser-induced choroidal neovascularization (mCNV). Here, we identified the angiogenic factor Osteopontin (Opn), also known as "secreted phosphoprotein 1" (Spp1), as one of the most highly expressed genes in retinal microglia in the course of CNV formation. We confirmed the presence of SPP1 at the lesion site in recruited retinal microglia in Cx3cr1 ^CreER:Rosa26-tdTomato reporter mice by confocal microscopy and in whole retinal tissue lysates by ELISA highlighting a massive local production of SPP1. Inhibition of SPP1 by intravitreal injection of an anti-SPP1 antibody significantly increased the lesion size compared to IgG-treated control eyes. In line with our results in rodents, we found an increased SPP1 mRNA expression in surgically extracted human choroidal neovascular (hCNV) membranes by the quantitative RNA-seq approach of massive analysis of cDNA ends (MACE). Numerous IBA1⁺SPP1⁺ myeloid cells were detected in human CNV membranes. Taken together, these results highlight the importance of SPP1 in the formation of CNV and potentially offer new opportunities for therapeutic intervention by modulating the SPP1 pathway.

Monocyte Transmodulation: The Next Novel Therapeutic Approach in Overcoming Ischemic Stroke?

The immune response following neuroinflammation is a vital element of ischemic stroke pathophysiology. After the onset of ischemic stroke, a specialized vasculature system that effectively protects central nervous system tissues from the invasion of blood cells and other macromolecules is broken down within minutes, thereby triggering the inflammation cascade, including the infiltration of peripheral blood leukocytes. In this series of processes, blood-derived monocytes have a significant effect on the outcome of ischemic stroke through neuroinflammatory responses. As neuroinflammation is a necessary and pivotal component of the reparative process after ischemic stroke, understanding the role of infiltrating monocytes in the modulation of inflammatory responses may offer a great opportunity to explore new therapies for ischemic stroke. In this review, we discuss and highlight the function and involvement of monocytes in the brain after ischemic injury, as well as their impact on tissue damage and repair.

Assessment of Serum Cytokines and Oxidative Stress Markers in Elite Athletes Reveals Unique Profiles Associated With Different Sport Disciplines

Objectives

Circulating cytokines and oxidative stress markers vary in response to different exercise regimens. This study aims to compare the immune-inflammatory and oxidative stress profiles of elite athletes from different sport disciplines as potential biomarkers of muscle damage, and cardiovascular demand.

Methods

Serum samples from 88 consented elite male athletes from different sports disciplines (aquatics, n = 11, athletics, n = 22, cycling, n = 19, football, n = 28 and weightlifting, n = 8) collected at the anti-doping lab in Italy were screened for 38 cytokines and oxidative stress markers. Comparisons were made between different level of power, cardiovascular demand (CD) and endurance, as well as among the sport types.

Results

The anti-inflammatory interleukin (IL)-10 was higher (p = 0.04) in moderate power compared with the high power group. Conversely, superoxide dismutase (SOD; p = 0.001) and malondialdehyde (MDA; p = 0.007) levels were greater in the higher power groups compared with the lower power counterpart. Among athletes who belong to different CD ranks, IL-1β and monocyte chemoattractant protein-1(MCP1) levels were higher (p = 0.03) in the low CD-rank group compared with high CD counterpart, whereas, SOD levels were higher (p = 0.001) in high and moderate CD-rank groups compared to low counterpart. For endurance groups, IL-10 and macrophage inflammatory protein (MIP)-1beta were increased (p = 0.03) in low/moderate endurance compared with the high endurance group. Finally, MIP1-beta, SOD and catalase varied significantly among the sports groups.

Conclusion

Specific markers of inflammation and oxidative stress are associated with different sports disciplines and could be utilized as potential biomarkers of athletes' health, performance, and recovery from injury.

Preclinical Intracranial Aneurysm Models: A Systematic Review

Intracranial aneurysms (IA) are characterized by weakened cerebral vessel walls that may lead to rupture and subarachnoid hemorrhage. The mechanisms behind their formation and progression are yet unclear and warrant preclinical studies. This systematic review aims to provide a comprehensive, systematic overview of available animal models for the study of IA pathobiology. We conducted a systematic literature search using the PubMed database to identify preclinical studies employing IA animal models. Suitable articles were selected based on predefined eligibility criteria following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies were reviewed and categorized according to the experimental animal and aneurysm model. Of 4266 returned results, 3930 articles were excluded based on the title and/or abstract and further articles after screening the full text, leaving 123 studies for detailed analysis. A total of 20 different models were found in rats (nine), mice (five), rabbits (four), and dogs (two). Rat models constituted the most frequently employed intracranial experimental aneurysm model (79 studies), followed by mice (31 studies), rabbits (12 studies), and two studies in dogs. The most common techniques to induce cerebral aneurysms were surgical ligation of the common carotid artery with subsequent induction of hypertension by ligation of the renal arteries, followed by elastase-induced creation of IAs in combination with corticosterone- or angiotensin-induced hypertension. This review provides a comprehensive summary of the multitude of available IA models to study various aspects of aneurysm formation, growth, and rupture. It will serve as a useful reference for researchers by facilitating the selection of the most appropriate model and technique to answer their scientific question.

The role of IL-1β in aortic aneurysm

Interleukin-1β (IL-1β) is a vital cytokine that plays an important role in regulating immune responses to infectious challenges and sterile insults. In addition, two endogenous inhibitors of functional receptor binding, IL-1 receptor antagonist (IL-1Ra), complete the family. To gain biological activity, IL-1β requires processing by the protease caspase-1 and activation of inflammasomes. Numerous clinical association studies and experimental approaches have implicated members of the IL-1 family, their receptors, or components of the processing machinery in the underlying processes of cardiovascular diseases. Here, we summarize the current state of knowledge regarding the pro-inflammatory and disease-modulating role of the IL-1 family in aneurysm. We discuss clinical evidence, signalling pathway, and mechanism of action and last, lend a perspective on currently developing therapeutic strategies involving IL-1β in aneurysm.

The Link between Regional Tidal Stretch and Lung Injury during Mechanical Ventilation

The aim of this study was to assess the association between regional tidal volume (Vt), regional functional residual capacity (FRC), and the expression of genes linked with ventilator-induced lung injury. Two groups of BALB/c mice (n = 8 per group) were ventilated for 2 hours using a protective or injurious ventilation strategy, with free-breathing mice used as control animals. Regional Vt and FRC of the ventilated mice was determined by analysis of high-resolution four-dimensional computed tomographic images taken at baseline and after 2 hours of ventilation and corrected for the volume of the region (i.e., specific [s]Vt and specific [s]FRC). RNA concentrations of 21 genes in 10 different lung regions were quantified using a quantitative PCR array. sFRC at baseline varied regionally, independent of ventilation strategy, whereas sVt varied regionally depending on ventilation strategy. The expression of IL-6 (P = 0.04), Ccl2 (P < 0.01), and Ang-2 (P < 0.05) was associated with sVt but not sFRC. The expression of seven other genes varied regionally (IL-1β and RAGE [receptor for advanced glycation end products]) or depended on ventilation strategy (Nfe2l2 [nuclear factor erythroid-derived 2 factor 2], c-fos, and Wnt1) or both (TNF-α and Cxcl2), but it was not associated with regional sFRC or sVt. These observations suggest that regional inflammatory responses to mechanical ventilation are driven primarily by tidal stretch.

TLR4 (Toll-Like Receptor 4) Mediates the Development of Intracranial Aneurysm Rupture

Inflammation is emerging as a critical factor in the pathophysiology of intracranial aneurysm. TLR4 (toll-like receptor 4) contributes not only to the innate immune responses but also to the inflammatory processes associated with vascular disease. Therefore, we examined the contribution of the TLR4 pathway to the development of the rupture of intracranial aneurysm. We used a mouse model of intracranial aneurysm. TLR4 inhibition significantly reduced the development of aneurysmal rupture. In addition, the rupture rate and levels of proinflammatory cytokines were lower in TLR4 knockout mice than the control littermates. Macrophage/monocyte-specific TLR4 knockout mice had a lower rupture rate than the control littermate mice. Moreover, the deficiency of MyD88 (myeloid differentiation primary-response protein 88), a key mediator of TLR4, reduced the rupture rate. These findings suggest that the TLR4 pathway promotes the development of intracranial aneurysmal rupture by accelerating inflammation in aneurysmal walls. Inhibition of the TLR4 pathway in inflammatory cells may be a promising approach for the prevention of aneurysmal rupture and subsequent subarachnoid hemorrhage.

Localized Intra-Arterial Gene Delivery Using AAV

In vivo gene therapy is a tremendous tool for a wide variety of genetic modifications. However, often a specific and precise local administration of the viral vector is necessary to deliver the genetic payload in vivo. For many animal studies using viral vectors, such as those investigating neurological disorders, the vector is targeted directly into the tissue/organ of interest. On the other hand, in vascular disease research, viral vectors are administered systemically, either via a tail vein injection or through catheter-mediated infusion, which results in off-target transduction of cells and tissues. Targeting cells in the vascular wall without off-target activity, however, requires localized delivery in order to efficiently target cells of the internal vasculature. Here we describe a novel murine in vivo targeted intra-arterial viral vector delivery method, which has been developed in order to be able to perform more intricate studies in cardiovascular disease.

Inflammatory cytokine profiles in eyes with primary angle-closure glaucoma

Acute primary angle-closure (APAC) eyes show an early 'acute inflammatory' condition, while the inflammation condition has not been fully elucidated in the development of primary angle-closure glaucoma (PACG). To evaluate the roles of inflammatory cytokines in the pathogenesis of PACG, this cross-sectional study involved 40 eyes of 32 PACG patients who required trabeculectomy and 24 eyes of 24 patients who required cataract surgery. The aqueous humor samples were collected at the time of surgery. Fifteen inflammatory cytokines were detected using the multiplex bead immunoassay technique, and the clinical information was recorded for the correlation analysis. Eight of the 15 cytokines were all detectable in both groups, including granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-6, IL-8, monocyte chemotactic protein (MCP)-1, MCP-3, macrophage-derived chemokine (MDC), macrophage inflammatory protein (MIP)-1β, and vascular endothelial growth factor (VEGF). When compared with the cataract patients, the MCP-3, MDC, and VEGF levels were elevated in the PACG patients, while the MCP-1 and MIP-1β levels were decreased. However, the G-CSF, IL-6, and IL-8 levels were similar between the two groups. The MCP-1 concentration was elevated accordingly as the disease progressed in the PACG patients. Our results suggest the PACG eyes retained a 'mild inflammation' condition in the aqueous humor, and MCP-1 may play an important role in the progression of this disease.

Upregulation of osteopontin expression via the interaction of macrophages and fibroblasts under IL-1b stimulation

BACKGROUND

Fibrosis is attributed to dysregulation of tissue-remodeling. In remodeling areas, fibroblasts and macrophages actively make contact with each other. Osteopontin (OPN) is a pro-fibrotic molecule, whose expression is upregulated by interleukin (IL)-1β via secretion of its downstream cytokines, such as IL-6. Here, we investigated the effect of interaction between fibroblasts and macrophages under IL-1β stimulation on the expression of OPN.

METHODS

We used human lung fibroblasts and THP-1 macrophages differentiated from THP-1 cells using phorbol 12-myristate 13-acetate. These cells were either cultured alone or co-cultured under IL-1β stimulation. Secretion of OPN and IL-6 were examined by enzyme-linked immunosorbent assay, and mRNA expression was assessed by quantitative real-time PCR. The effects of siRNA against IL-6 or OPN on OPN expression were evaluated.

RESULTS

OPN expression increased when fibroblasts and THP-1 macrophages were co-cultured under IL-1β stimulation. The siRNA against IL-6 in fibroblasts suppressed the upregulation of OPN expression during co-culture, whereas siRNA against IL-6 in THP-1 macrophages did not. The upregulation of expression of OPN mRNA in fibroblasts or THP-1 macrophages when co-cultured under IL-1β stimulation was mediated by IL-6 from fibroblasts. OPN from THP-1 macrophages was involved in the increase of OPN expression in fibroblasts.

CONCLUSIONS

The present study revealed the crosstalk between fibroblasts and THP-1 macrophages under IL-1β stimulation, where IL-6 from fibroblasts, stimulated by IL-1β, upregulated OPN expression in fibroblasts themselves via increase in OPN from THP-1 macrophages. The fibroblasts/macrophages network may induce activation or qualitative changes in both cells, which contributes to inflammation-associated fibrosis.

Local Delivery Is Critical for Monocyte Chemotactic Protein-1 Mediated Site-Specific Murine Aneurysm Healing

Background

Local delivery of monocyte chemotactic protein-1 (MCP-1/CCL2) via our drug-eluting coil has been shown to promote intrasaccular aneurysm healing via an inflammatory pathway.

Objective

In this study, we validate the importance of local MCP-1 in murine aneurysm healing. Whether systemic, rather than local, delivery of MCP-1 can direct site-specific aneurysm healing has significant translational implications. If systemic MCP-1 is effective, then MCP-1 could be administered as a pill rather than by endovascular procedure. Furthermore, we confirm that MCP-1 is the primary effector in our MCP-1 eluting coil-mediated murine aneurysm healing model.

Methods

We compare aneurysm healing with repeated intraperitoneal MCP-1 versus vehicle injection, in animals with control poly(lactic-co-glycolic) acid (PLGA)-coated coils. We demonstrate elimination of the MCP-1-associated tissue-healing response by knockout of MCP-1 or CCR2 (MCP-1 receptor) and by selectively inhibiting MCP-1 or CCR2. Using immunofluorescent probing, we explore the cell populations found in healed aneurysm tissue following each intervention.

Results

Systemically administered MCP-1 with PLGA coil control does not produce comparable aneurysm healing, as seen with MCP-1 eluting coils. MCP-1-directed aneurysm healing is eliminated by selective inhibition of MCP-1 or CCR2 and in MCP-1-deficient or CCR2-deficient mice. No difference was detected in M2 macrophage and myofibroblast/smooth muscle cell staining with systemic MCP-1 versus vehicle in aneurysm wall, but a significant increase in these cell types was observed with MCP-1 eluting coil implant and attenuated by MCP-1/CCR2 blockade or deficiency.

Conclusion

We show that systemic MCP-1 concurrent with PLGA-coated platinum coil implant is not sufficient to produce site-specific aneurysm healing. MCP-1 is a critical, not merely complementary, actor in the aneurysm healing pathway.

Temporal cascade of inflammatory cytokines and cell-type populations in monocyte chemotactic protein-1 (MCP-1)-mediated aneurysm healing

BACKGROUND

We have previously shown that monocyte chemotactic protein-1 (MCP-1) promotes aneurysm healing.

OBJECTIVE

To determine the temporal cascade and durability of aneurysm healing.

METHODS

Murine carotid aneurysms were treated with MCP-1-releasing or poly(lactic-co-glycolic) acid (PLGA)-only coils. Aneurysm healing was assessed by quantitative measurements of intraluminal tissue ingrowth on 5 μm sections by blinded observers.

RESULTS

Aneurysm healing occurred in stages characteristic of normal wound healing. The 1st stage (day 3) was characterized by a spike in neutrophils and T cells. The 2nd stage (week 1) was characterized by an influx of macrophages and CD45+ cells significantly greater with MCP-1 than with PLGA (p<0.05). The third stage (week 2-3) was characterized by proliferation of smooth muscle cells and fibroblasts (greater with MCP-1 than with PLGA, p<0.05). The fourth stage (3-6 months) was characterized by leveling off of smooth muscle cells and fibroblasts. M1 macrophages were greater at week 1, whereas M2 macrophages were greater at weeks 2 and 3 with MCP-1 than with PLGA. Interleukin 6 was present early and increased through week 2 (p<0.05 compared with PLGA) then decreased and leveled off through 6 months. Tumour necrosis factor α was present early and remained constant through 6 months. MCP-1 and PLGA treatment had similar rates of tissue ingrowth at early time points, but MCP-1 had a significantly greater tissue ingrowth at week 3 (p<0.05), which persisted for 6 months.

CONCLUSIONS

The sequential cascade is consistent with an inflammatory model of injury, repair, and remodeling.