Comparison of high-resolution synchrotron-radiation-based phase-contrast imaging and absorption-contrast imaging for evaluating microstructure of vascular networks in rat brain: from 2D to 3D views

Exosomal Mir-3613-3p derived from oxygen-glucose deprivation-treated brain microvascular endothelial cell promotes microglial M1 polarization

BACKGROUND

Brain microvascular endothelial cell (BMEC) injury can affect neuronal survival by modulating immune responses through the microenvironment. Exosomes are important vehicles of transport between cells. However, the regulation of the subtypes of microglia by BMECs through the exosome transport of microRNAs (miRNAs) has not been established.

METHODS

In this study, exosomes from normal and oxygen-glucose deprivation (OGD)-cultured BMECs were collected, and differentially expressed miRNAs were analyzed. BMEC proliferation, migration, and tube formation were analyzed using MTS, transwell, and tube formation assays. M1 and M2 microglia and apoptosis were analyzed using flow cytometry. miRNA expression was analyzed using real-time polymerase chain reaction (RT-qPCR), and IL-1β, iNOS, IL-6, IL-10, and RC3H1 protein concentrations were analyzed using western blotting.

RESULTS

We found that miR-3613-3p was enriched in BMEC exosome by miRNA GeneChip assay and RT-qPCR analysis. miR-3613-3p knockdown enhanced cell survival, migration, and angiogenesis in the OGD-treated BMECs. In addition, BMECs secrete miR-3613-3p to transfer into microglia via exosomes, and miR-3613-3p binds to the RC3H1 3' untranslated region (UTR) to reduce RC3H1 protein levels in microglia. Exosomal miR-3613-3p promotes microglial M1 polarization by inhibiting RC3H1 protein levels. BMEC exosomal miR-3613-3p reduces neuronal survival by regulating microglial M1 polarization.

CONCLUSIONS

miR-3613-3p knockdown enhances BMEC functions under OGD conditions. Interfering with miR-3613-3p expression in BMSCs reduced the enrichment of miR-3613-3p in exosomes and enhanced M2 polarization of microglia, which contributed to reduced neuronal apoptosis.

Advanced high resolution three-dimensional imaging to visualize the cerebral neurovascular network in stroke

As an important method to accurately and timely diagnose stroke and study physiological characteristics and pathological mechanism in it, imaging technology has gone through more than a century of iteration. The interaction of cells densely packed in the brain is three-dimensional (3D), but the flat images brought by traditional visualization methods show only a few cells and ignore connections outside the slices. The increased resolution allows for a more microscopic and underlying view. Today's intuitive 3D imagings of micron or even nanometer scale are showing its essentiality in stroke. In recent years, 3D imaging technology has gained rapid development. With the overhaul of imaging mediums and the innovation of imaging mode, the resolution has been significantly improved, endowing researchers with the capability of holistic observation of a large volume, real-time monitoring of tiny voxels, and quantitative measurement of spatial parameters. In this review, we will summarize the current methods of high-resolution 3D imaging applied in stroke.

Difficulties and Countermeasures in Hospital Emergency Management for Fast-Lane Treatment of Acute Stroke During the COVID-19 Epidemic Prevention and Control

Background: Coronavirus disease 2019 (COVID-19) has a long incubation period and a high degree of infectivity. Patients may not show specific signs or symptoms of upper respiratory tract infection, and the age of onset is similar to that of stroke. Furthermore, an increase in neurological conditions, specifically acute cerebrovascular disease, has been detected. Providing emergency treatment for acute stroke in accordance with the strict epidemic control measures is currently one of the main challenges, as acute stroke is rapid onset and a major cause of death and disability globally. We aimed to evaluate the emergency treatment system for acute stroke during the epidemic control period to provide a reference and basis for informing government and medical institutions on improving patient treatment rates during this period. Methods: Difficulties faced in providing emergency treatment for stroke during an epidemic were investigated and combined with medical educational resources and clinical management experiences to construct an emergency treatment framework for acute stroke during the epidemic. Findings: Currently, emergency treatment measures for acute stroke during the epidemic control period are limited because the main focus is on identifying COVID-19 comorbidities during the critical period. Establishing standards for patients in the neurological outpatient consultation rooms and emergency observation and resuscitation zones; implementing a fast-lane system for the emergency treatment of patients with acute stroke, and strengthening ward management and medicine popularization, can improve the treatment efficiency for stroke patients during the epidemic and provide a reference for peers in clinical practice. Interpretation: Emergency treatment for acute stroke during COVID-19 epidemic control period requires a joint promotion of clinical, popularization, and teaching resources.