Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202409000-00033/figure1/v/2024-01-16T170235Z/r/image-tiff We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury. However, its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear. In this study, we first used an HT22 scratch injury model to mimic traumatic brain injury, then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p. We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress. Furthermore, luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α, while an IRE1α functional salvage experiment confirmed that miR-124-3p targeted IRE1α and reduced its expression, thereby inhibiting endoplasmic reticulum stress in injured neurons. Finally, we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced. These findings suggest that, after repetitive mild traumatic brain injury, miR-124-3 can be transferred from microglia-derived exosomes to injured neurons, where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress. Therefore, microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

Value of long non-coding RNA HAS2-AS1 as a diagnostic and prognostic marker of glioma

BACKGROUND

Glioma presents high incidence and poor prognosis, and therefore more effective treatments are needed. Studies have confirmed that long non-coding RNAs (lncRNAs) basically regulate various human diseases including glioma. It has been theorized that HAS2-AS1 serves as an lncRNA to exert an oncogenic role in varying cancers. This study aimed to assess the value of lncRNA HAS2-AS1 as a diagnostic and prognostic marker for glioma.

METHODS

The miRNA expression data and clinical data of glioma were downloaded from the TCGA database for differential analysis and survival analysis. In addition, pathological specimens and specimens of adjacent normal tissue from 80 patients with glioma were used to observe the expression of HAS2-AS1. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic ability and prognostic value of HAS2-AS1 in glioma. Meanwhile, a Kaplan-Meier survival curve was plotted to evaluate the survival of glioma patients with different HAS2-AS1 expression levels.

RESULTS

HAS2-AS1 was significantly upregulated in glioma tissues compared with normal tissue. The survival curves showed that overexpression of HAS2-AS1 was associated with poor overall survival (OS) and progression-free survival (PFS). Several clinicopathological factors of glioma patients, including tumor size and WHO grade, were significantly correlated with HAS2-AS1 expression in tissues. The ROC curve showed an area under the curve (AUC) value of 0.863, indicating that HAS2-AS1 had good diagnostic value. The ROC curve for the predicted OS showed an AUC of 0.906, while the ROC curve for predicted PFS showed an AUC of 0.88. Both suggested that overexpression of HAS2-AS1 was associated with poor prognosis.

CONCLUSIONS

Normal tissues could be clearly distinguished from glioma tissues based on HAS2-AS1 expression. Moreover, overexpression of HAS2-AS1 indicated poor prognosis in glioma patients. Therefore, HAS2-AS1 could be used as a diagnostic and prognostic marker for glioma.

Strictureplasty may lead to increased preference in the surgical management of Crohn's disease: a case-matched study

BACKGROUND

Resection and strictureplasty are the two surgical modalities used in the management of Crohn's disease (CD). The objective of this study was to compare morbidity and clinical recurrence between patients who underwent strictureplasty and patients who underwent resection.

METHODS

Patients with CD who underwent strictureplasty between January 2012 and December 2022 were enrolled. The patients were well matched with patients who underwent resection without strictureplasty. Patient- and disease-specific characteristics, postoperative morbidity, and clinical recurrence were also analyzed.

RESULTS

A total of 118 patients who underwent a total of 192 strictureplasties were well matched to 118 patients who underwent resection. The strictureplasty group exhibited significantly less blood loss (30 ml versus 50 ml, p < 0.001) and stoma creation (2.5% versus 16.9%, p < 0.001). No significant difference was found regarding postoperative complications or length of postoperative stay. At the end of the follow-up, the overall rate of clinical recurrence was 39.4%, and no difference was observed between the two groups. Postoperative prophylactic use of biologics (odds ratio = 0.2, p < 0.001) was the only protective factor against recurrence.

CONCLUSION

Strictureplasty does not increase the risk of complications or recurrence compared with resection. It represents a viable alternative to resection in selected patients, and as such, it should have a broader scope of indications and greater acceptance among surgeons.

Distinguishment between high-grade gliomas and solitary brain metastases in peritumoural oedema: quantitative analysis using synthetic MRI at 3 T

AIM

To investigate the efficacy of synthetic magnetic resonance imaging (MRI) in distinguishing high-grade gliomas (HGGs) from solitary brain metastases (SBMs) in peritumoural oedema.

MATERIALS AND METHODS

Thirty-five patients with HGGs and 25 patients with SBMs were recruited and scanned using synthetic MRI using a 3 T scanner. Two radiologists measured synthetic MRI-derived relaxation values independently (T1, T2, proton density [PD]) in the peritumoural oedema, which was used to generate quantitative metrics before (T1native, T2native, and PDnative) and after (T1post, T2post, and PDpost) contrast agent injection. Student's t-test or the Mann-Whitney U-test was performed to detect statistically significant differences in the aforementioned metrics in peritumoural oedema between HGGs and SBMs. The receiver operating characteristic (ROC) curves were plotted to evaluate the efficacy of each metric in distinguishing the two groups, and the areas under the curves (AUCs) were compared pairwise by performing the Delong test.

RESULTS

The mean T1native, T2native, and T1post values in the peritumoural oedema of HGGs were significantly lower compared with SBMs (all p<0.05). The T1post value had a higher AUC (0.843) in differentiating HGGs and SBMs than all other individual metrics (all p<0.05). The combined T1native, T2native, and T1post model had the best distinguishing performance with an AUC, sensitivity, and specificity of 0.987, 94.3%, and 100%, respectively.

CONCLUSIONS

Synthetic MRI may be a potential supplement to the preoperative diagnosis of HGGs and SBMs in clinical practice, as the synthetic MRI-derived tri-parametric model in the peritumoural oedema showed significantly improved diagnostic performance in distinguishing HGGs from SBMs.

IL-33/ST2 Axis: A Potential Therapeutic Target in Neurodegenerative Diseases

Interleukin 33 (IL-33) belongs to the IL-1 family and is localized in the nucleus. IL-33 is primarily composed of three distinct domains, namely the N-terminal domain responsible for nuclear localization, the intermediate sense protease domain, and the C-terminal cytokine domain. Its specific receptor is the suppression of tumorigenicity 2 (ST2), which is detected in serum-stimulated fibroblasts and oncogenes. While most other cytokines are actively produced in cells, IL-33 is passively produced in response to tissue damage or cell necrosis, thereby suggesting its role as an alarm following cell infection, stress, or trauma. IL-33 plays a crucial role in congenital and acquired immunity, which assists in the response to environmental stress and maintains tissue homeostasis. IL-33/ST2 interaction further produces many pro-inflammatory cytokines. Moreover, IL-33 is crucial for central nervous system (CNS) homeostasis and the pathogenic mechanisms underlying CNS degenerative disorders. The present work summarizes the structure of IL-33, its fundamental activities, and its role in immunoregulation and neurodegenerative diseases. Therefore, this work proposes that IL-33 may play a role in the pathogenic mechanism of diseases and can be used in the development of treatment strategies.

[Application of synthetic MRI in predicting isocitrate dehydrogenase 1 genotypes in gliomas]

This study analyzed the clinical and imaging data of 81 glioma patients who underwent brain synthetic MRI and diffusion weighted imaging (DWI) examination in the General Hospital of Ningxia Medical University from August 2020 to September 2021 to explore the value of synthetic MRI relaxation quantitative value in predicting the genotype of isocitrate dehydrogenase 1 (IDH1) in gliomas. There were 44 males and 37 females, those patients with an aged 50.0 (36.5, 59.0) years. The tumor pre-T1, pre-T2, pre-PD, post-T1 and ADC values were obtained by outlining the region of interest (ROI). Univariate analysis was used to compare the differences of parameter values between groups, and the receiver operating characteristic was used to evaluate the diagnostic efficacy of each parameter value in predicting glioma IDH1 genotype. The results showed that the pre-T1 and pre-PD values [M (Q1, Q3)] of IDH1m glioma were lower than those of IDH1w glioma [1 462.75 (1 306.41, 1 567.75) ms vs 1 532.83 (1 434.67, 1 617.67) ms, 84.18 (82.28, 86.41) pu vs 85.85 (84.65, 86.90) pu] (all P<0.05). The post-T1 and ADC values of IDH1m glioma were higher than those of IDH1w glioma [1 054.50 (631.92, 1 262.63) ms vs 669.67 (535.17, 823.33) ms, 1.20 (0.86, 1.35) ×10-3 mm2/s vs 0.80 (0.76, 0.93) ×10-3 mm2/s] (all P<0.05). The AUC of the combined model (pre-T1+pre-PD+post-T1+ADC+Age) is 0.828 (95%CI:0.729-0.903). Synthetic MRI relaxation quantitative values are helpful to distinguish IDH1 genotypes in glioma. The diagnostic efficacy of the multi-parameter combined model based on pre-T1, pre-PD, post-T1, ADC, and age is better than that of the single parameter, and it can be used as an effective strategy to improve the differential diagnosis ability of gliomas molecular markers.

[Single-cell RNA sequencing deciphers transcriptional profiles of hepatocytes in mouse with hepatic alveolar echinococcosis]

OBJECTIVE

To investigate the cell composition and the transcriptional characteristics in microenvironments of hepatic tissues in mice at late stage of Echinococcus multilocularis infection at a single-cell level.

METHODS

Peri-lesion and paired distal hepatic specimens were collected from two BALB/c mice (6 to 8 weeks old) infected with E. multilocularis for single-cell RNA sequencing. The Seurat package in the R software was employed for quality control of data, multi-sample integration and correction of batch effects, and uniform manifold approximation and projection (UMAP) algorithm was used for cell clustering. Cell types were annotated using classical marker genes. Differentially expressed genes were screened in each cell type through differential gene expression analysis, and the biological roles of cells were predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses.

RESULTS

A total of 43 710 cells from peri-lesion and distal hepatic tissues of E. multilocularis-infected mice were analyzed, and were classified into 11 cell types, including neutrophils, T cells, macrophages, granulocyte-monocyte progenitor cells, B cells, plasma cells, basophils, hepatic stellate cells, endothelial cells, hepatocytes, and platelets. T cells were the largest population of immune cells in the microenvironment of hepatic tissues, including five CD4⁺ T cell subsets, two CD8⁺ T cell subsets and phosphoantigen-reactive γδT cells. The proportions of CD4⁺ helper T cells and cytotoxic CD4⁺ T cells decreased and the proportion of T helper 2 (Th2) cells increased in peri-lesion tissues relative to distal hepatic tissues. In addition, the differentially expressed genes in Th2 cells were associated with negative regulation of the immune system, and the highly expressed genes in cytotoxic CD4⁺ T cells correlated with activation of the immune system.

CONCLUSIONS

Single-cell RNA sequencing deciphers the cell composition and distribution in microenvironments of hepatic tissues from mice infected with E. multilocularis, and the increased proportion of Th2 cells in peri-lesion hepatic tissues may be associated with formation of immunosuppressive microenvironments.

Intranasal Delivery of Gene-Edited Microglial Exosomes Improves Neurological Outcomes after Intracerebral Hemorrhage by Regulating Neuroinflammation

Neural inflammatory response is a crucial pathological change in intracerebral hemorrhage (ICH) which accelerates the formation of perihematomal edema and aggravates neural cell death. Although surgical and drug treatments for ICH have advanced rapidly in recent years, therapeutic strategies that target and control neuroinflammation are still limited. Exosomes are important carriers for information transfer among cells. They have also been regarded as a promising therapeutic tool in translational medicine, with low immunogenicity, high penetration through the blood-brain barrier, and ease of modification. In our previous research, we have found that exogenous administration of miRNA-124-overexpressed microglial exosomes (Exo-124) are effective in improving post-injury cognitive impairment. From this, we evaluated the potential therapeutic effects of miRNA-124-enriched microglial exosomes on the ICH mice in the present study. We found that the gene-edited exosomes could attenuate neuro-deficits and brain edema, improve blood-brain barrier integrity, and reduce neural cell death. Moreover, the protective effect of Exo-124 was abolished in mice depleted of Gr-1⁺ myeloid cells. It suggested that the exosomes exerted their functions by limiting the infiltration of leukocyte into the brain, thus controlling neuroinflammation following the onset of ICH. In conclusion, our findings provided a promising therapeutic strategy for improving neuroinflammation in ICH. It also opens a new avenue for intranasal delivery of exosome therapy using miRNA-edited microglial exosomes.

Functional network properties derived from wide-field calcium imaging differ with wakefulness and across cell type

To improve 'bench-to-bedside' translation, it is integral that knowledge flows bidirectionally-from animal models to humans, and vice versa. This requires common analytical frameworks, as well as open software and data sharing practices. We share a new pipeline (and test dataset) for the preprocessing of wide-field optical fluorescence imaging data-an emerging mode applicable in animal models-as well as results from a functional connectivity and graph theory analysis inspired by recent work in the human neuroimaging field. The approach is demonstrated using a dataset comprised of two test-cases: (1) data from animals imaged during awake and anesthetized conditions with excitatory neurons labeled, and (2) data from awake animals with different genetically encoded fluorescent labels that target either excitatory neurons or inhibitory interneuron subtypes. Both seed-based connectivity and graph theory measures (global efficiency, transitivity, modularity, and characteristic path-length) are shown to be useful in quantifying differences between wakefulness states and cell populations. Wakefulness state and cell type show widespread effects on canonical network connectivity with variable frequency band dependence. Differences between excitatory neurons and inhibitory interneurons are observed, with somatostatin expressing inhibitory interneurons emerging as notably dissimilar from parvalbumin and vasoactive polypeptide expressing cells. In sum, we demonstrate that our pipeline can be used to examine brain state and cell-type differences in mesoscale imaging data, aiding translational neuroscience efforts. In line with open science practices, we freely release the pipeline and data to encourage other efforts in the community.

Potential blood biomarkers for chronic traumatic encephalopathy: The multi-omics landscape of an observational cohort

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts, which is susceptible in elderly people with declined mobility, athletes of full contact sports, military personnel and victims of domestic violence. It has been pathologically diagnosed in brain donors with a history of repetitive mild traumatic brain injury (rmTBI), but cannot be clinically diagnosed for a long time. By the continuous efforts by neuropathologists, neurologists and neuroscientists in recent 10 years, an expert consensus for the diagnostic framework of CTE was proposed in 2021 funded by the National Institute of Neurological Disorders and Stroke. The new consensus contributes to facilitating research in the field. However, it still needs to incorporate in vivo biomarkers to further refine and validate the clinical diagnostic criteria. From this, a single-center, observational cohort study has been being conducted by Tianjin Medical University General Hospital since 2021. As a pilot study of this clinical trial, the present research recruited 12 pairs of gender- and age-matched rmTBI patients with healthy subjects. Their blood samples were collected for exosome isolation, and multi-omics screening to explore potential diagnostic biomarkers in blood and its exosomes. The expression level of CHL1 protein, KIF2A mRNA, LIN7C mRNA, miR-297, and miR-1183 in serum and exosomes were found to be differentially expressed between groups. Besides, serum and exosomal CHL1, KIF2A, and miR-1183, as well as exosomal miR-297 were further verified as potential biomarkers for CTE by low-throughput assays. They are expected to contribute to establishing a novel set of CTE diagnostic signatures with classic neurodegenerative indicators in our future study, thereby updating the consensus diagnostic criteria for CTE by incorporating new evidence of the in vivo biomarkers.

Test of a multi-gigawatt, 800 ns high power microwave driver based on Marx generator and metal-oxide varistors

High power microwave (HPM) sources usually require a well-defined rectangular pulse waveform, which is especially true for the case of long pulse (>100 ns), stable, and high efficiency operation. Most long pulse HPM drivers are realized with pulse forming networks. This paper presents a long pulse driver composed of a conventional Marx generator and metal-oxide varistors (MOVs), utilizing the MOV's nonlinear V-I characteristic. This method is easy to implement, and it has an additional benefit that the voltage can be stabilized even if the load's impedance changes slightly. A low inductance zig-zag folding structure of the MOV is designed to decrease its size and self-inductance. An LC filter is used to reduce the energy loss in the MOV. In the experiment, a 400 kV, 800 ns long pulse is achieved at a foil-less electron diode, and longer than 300 ns HPM generation is obtained.

Mesenchymal stromal cell treatment attenuates repetitive mild traumatic brain injury-induced persistent cognitive deficits via suppressing ferroptosis

The incidence of repetitive mild traumatic brain injury (rmTBI), one of the main risk factors for predicting neurodegenerative disorders, is increasing; however, its underlying mechanism remains unclear. As suggested by several studies, ferroptosis is possibly related to TBI pathophysiology, but its effect on rmTBI is rarely studied. Mesenchymal stromal cells (MSCs), the most studied experimental cells in stem cell therapy, exert many beneficial effects on diseases of the central nervous system, yet evidence regarding the role of MSCs in ferroptosis and post-rmTBI neurodegeneration is unavailable. Our study showed that rmTBI resulted in time-dependent alterations in ferroptosis-related biomarker levels, such as abnormal iron metabolism, glutathione peroxidase (GPx) inactivation, decrease in GPx4 levels, and increase in lipid peroxidation. Furthermore, MSC treatment markedly decreased the aforementioned rmTBI-mediated alterations, neuronal damage, pathological protein deposition, and improved cognitive function compared with vehicle control. Similarly, liproxstatin-1, a ferroptosis inhibitor, showed similar effects. Collectively, based on the above observations, MSCs ameliorate cognitive impairment following rmTBI, partially via suppressing ferroptosis, which could be a therapeutic target for rmTBI.

RNA sequencing and iTRAQ proteomic data from an experiment examining the influence of conceptus presence and preovulatory estradiol on endometrial gene transcripts and proteins around maternal recognition of pregnancy in beef cattle

RNA sequencing reads and isobaric tags for a relative and absolute quantification (iTRAQ)-Based Proteomic Data were used to determine the impact of conceptus presence and preovulatory estradiol concentration on function of the d16 uterus in beef cattle. Conceptuses and endometrial biopsies were collected from the uterine horn ipsilateral to the corpus luteum. Total cellular RNA was extracted from endometrium for RNA sequencing across two lanes of a NovaSeq S2, 2 × 50-bp run. Two independent uterine luminal fluid pools (ULF) were made for each group: highE2/conceptus, highE2/noconceptus, lowE2/conceptus, and lowE2/noconceptus. Peptides were labeled with iTRAQ reagents and analyzed using 2-dimensional liquid chromatography mass spectrometry. Transcript abundances were determined using DESeq2 (FDR <0.05, FC>2). Scaffold Q+ was used to quantitate peptide and protein identifications in ULF. Datasets include uterine transcript and protein abundances among highE2/conceptus vs highE2/noconceptus and lowE2/conceptus vs lowE2/noconceptus groups. This information can be useful for further investigating the role of specific transcripts and proteins in the maintenance of early pregnancy in beef cattle. This dataset is related to the article ‘Influence of conceptus presence and preovulatory estradiol exposure on uterine gene transcripts and proteins around maternal recognition of pregnancy in beef cattle’ by E.J. Northrop-Albrecht, J.J.J. Rich, R.A. Cushman, R. Yao, X. Ge, G.A. Perry. Molecular and Cellular Endocrinology.

A Novel Blood Inflammatory Indicator for Predicting Deterioration Risk of Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) has a relatively higher incidence in aging people due to walking problems. Cranial computed tomography and magnetic resonance imaging provide the standard diagnostic tool to identify intracranial complications in patients with mTBI. However, it is still necessary to further explore blood biomarkers for evaluating the deterioration risk at the early stage of mTBI to improve medical decision-making in the emergency department. The activation of the inflammatory response is one of the main pathological mechanisms leading to unfavorable outcomes of mTBI. As complete blood count (CBC) analysis is the most extensively used laboratory test in practice, we extracted clinical data of 994 patients with mTBI from two large clinical cohorts (MIMIC-IV and eICU-CRD) and selected inflammation-related indicators from CBC analysis to investigate their relationship with the deterioration after mTBI. The combinatorial indices neutrophil-to-lymphocyte ratio (NLR), red cell distribution width-to-platelet ratio (RPR), and NLR times RPR (NLTRP) were supposed to be potential risk predictors, and the data from the above cohorts were integratively analyzed using our previously reported method named MeDICS. We found that NLR, RPR, and NLTRP levels were higher among deteriorated patients than non-deteriorated patients with mTBI. Besides, high NLTRP was associated with increased deterioration risk, with the odds ratio increasing from NLTRP of 1–2 (2.69, 1.48–4.89) to &gt; 2 (4.44, 1.51–13.08), using NLTRP of 0–1 as the reference. NLTRP had a moderately good prognostic performance with an area under the ROC curve of 0.7554 and a higher prediction value than both NLR and RPR, indicated by the integrated discrimination improvement index. The decision curve analysis also showed greater clinical benefits of NLTRP than NLR and RPR in a large range of threshold probabilities. Subgroup analysis further suggested that NLTRP is an independent risk factor for the deterioration after mTBI. In addition, in vivo experiments confirmed the association between NLTRP and neural/systemic inflammatory response after mTBI, which emphasized the importance of controlling inflammation in clinical treatment. Consequently, NLTRP is a promising biomarker for the deterioration risk of mTBI. It can be used in resource-limited settings, thus being proposed as a routinely available tool at all levels of the medical system.

Modafinil Reduces Neuronal Pyroptosis and Cognitive Decline After Sleep Deprivation

Sleep deprivation (SD) induces systemic inflammation that promotes neuronal pyroptosis. The purpose of this study was to investigate the effect of an antioxidant modafinil on neuronal pyroptosis and cognitive decline following SD. Using a mouse model of SD, we found that modafinil improved learning and memory, reduced proinflammatory factor (IL-1β, TNF-α, and IL-6) production, and increased the expression of anti-inflammatory factors (IL-10). Modafinil treatment attenuated inflammasome activity and reduced neuronal pyroptosis involving the NLRP3/NLRP1/NLRC4-caspase-1-IL-1β pathway. In addition, modafinil induced an upregulation of brain-derived neurotrophic factor (BDNF) and synaptic activity. These results suggest that modafinil reduces neuronal pyroptosis and cognitive decline following SD. These effects should be further investigated in future studies to benefit patients with sleep disorders.

[A case of communicating oncocytic carcinoma of the naso-orbit]

A patient with a left eyelid mass for more than 1 year was admitted. One year ago, the patient underwent left sinus mass resection in another hospital, and the postoperative histopathology showed oncocytic carcinoma. Imaging examination in our hospital revealed lesions in the left eyelid and inner canthus, involving the canalis nasolacrimalis and orbit. The orbital mass was removed under general anesthesia. The histopathological diagnosis was oncocytic carcinoma.

Relationship Between Amyloid-β Deposition and Blood-Brain Barrier Dysfunction in Alzheimer's Disease

Amyloid-β (Aβ) is the predominant pathologic protein in Alzheimer's disease (AD). The production and deposition of Aβ are important factors affecting AD progression and prognosis. The deposition of neurotoxic Aβ contributes to damage of the blood-brain barrier. However, the BBB is also crucial in maintaining the normal metabolism of Aβ, and dysfunction of the BBB aggravates Aβ deposition. This review characterizes Aβ deposition and BBB damage in AD, summarizes their interactions, and details their respective mechanisms.

EGFR tyrosine kinase inhibitor Almonertinib induces apoptosis and autophagy mediated by reactive oxygen species in non-small cell lung cancer cells

Almonertinib, a new third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is highly selective to EGFR T790M-mutant non-small cell lung cancer (NSCLC). However, there is no available information on the form and molecular mechanism of Almonertinib-induced death in NSCLC cells. Herein, CCK-8 and colony formation assays, flow cytometry, electron microscopy, and western blots assay showed that Almonertinib inhibited NSCLC cells growth and proliferation by inducing apoptosis and autophagy which can be inhibited by a broad spectrum of caspase inhibitor Z-VAD-fmk or autophagy inhibitor chloroquine. Importantly, Almonertinib-induced autophagy was cytoprotective in NSCLC cells, and the blockade of autophagy improved cell apoptosis. In addition, Almonertinib increased reactive oxygen species (ROS) generation and clearance of ROS through pretreatment with N-acetyl-L-cysteine (NAC) inhibited the decrease of cell viability, apoptosis and increase of LC3-II induced by Almonertinib. The results of Western blot showed that both EGFR activity and downstream signaling pathways were inhibited by Almonertinib. Taken together, these findings indicated that Almonertinib induced apoptosis and autophagy by promoting ROS production in NSCLC cells.

POS0788 CIRCULATING EXOSOMES PROMOTE LUPUS NEPHRITIS IN MRL-LPR MICE

Background:

Systemic Lupus Erythematosus (SLE) is a prototypic autoimmune disease that characterized by the loss of self-tolerance and the production of autoantibodies (autoAbs) [1, 2]. Lupus nephritis (LN), the severe organ-threatening manifestations of SLE, could cause massive damage to patients[3, 4]. Currently, some exosomal microRNAs (miRNAs) are considered as potential biomarkers in SLE. However, the role of exosomal miRNAs in Lupus Nephritis (LN) remains unclear.

Objectives:

The purpose of this study was to investigate molecular mechanism of plasma exosomal miRNAs in the development of Lupus Nephritis.

Methods:

Circulating exosomes were isolated from plasma of patients with LN, SLE without LN (NLN). Plasma exosomes were authenticated by Western Blot, Nanosight Tracking Analysis (NTA) and transmission electron microscopy (TEM). Fluorescence microscopy of co-cultured plasma exosomes and podocytes demonstrated that exosomes were uptaken into podocytes. Moreover, cell apoptosis and the inflammation factors was assessed using Western Blot. We analyzed the expression profiles of miRNAs in LN and NLN exosomes and the expression profiles of mRNAs of podocytes stimulated with LN and NLN exosomes with the help of next generation sequencing (NGS).

Results:

We demonstrate that exosomes derived from LN plasma could be taken by neighboring podocytes and promote the apoptosis of podocytes and the expression of inflammation factors. In addition, the sequencing found that miRNAs were differentially expressed in LN and NLN exosomes and mRNAs were differentially expressed in podocytes stimulated with LN and NLN exosomes.

Conclusion:

LN plasma exosomes have a potency to stimulate the apoptosis of podocytes and the expression of inflammation factors. Moreover, differentially expressed miRNAs in exosomes play a potential role in the development of LN.

References:

[1]T. Colasanti, A. Maselli, F. Conti, M. Sanchez, C. Alessandri, C. Barbati, D. Vacirca, A. Tinari, F. Chiarotti, A. Giovannetti, F. Franconi, G. Valesini, W. Malorni, M. Pierdominici, E. Ortona, Autoantibodies to estrogen receptor α interfere with T lymphocyte homeostasis and are associated with disease activity in systemic lupus erythematosus, Arthritis and rheumatism, 64 (2012) 778-787.

[2]H.A. Al-Shobaili, A.A. Al Robaee, A.A. Alzolibani, Z. Rasheed, Antibodies against 4-hydroxy-2-nonenal modified epitopes recognized chromatin and its oxidized forms: role of chromatin, oxidized forms of chromatin and 4-hydroxy-2-nonenal modified epitopes in the etiopathogenesis of SLE, Disease markers, 33 (2012) 19-34.

[3]A. Kaul, C. Gordon, M.K. Crow, Z. Touma, M.B. Urowitz, R. van Vollenhoven, G. Ruiz-Irastorza, G. Hughes, Systemic lupus erythematosus, Nat Rev Dis Primers, 2 (2016) 16039.

[4]M.G. Tektonidou, A. Dasgupta, M.M. Ward, Risk of End-Stage Renal Disease in Patients With Lupus Nephritis, 1971-2015: A Systematic Review and Bayesian Meta-Analysis, Arthritis & rheumatology (Hoboken, N.J.), 68 (2016) 1432-1441.

Disclosure of Interests:

None declared

POS0401 THE APPLICATION OF MTX-LOADING DNA TETRAHEDRON IN TREATING COLLAGEN-INDUCED ARTHRITIS MICE VIA REGULATING MACROPHAGE

Background:

Rheumatoid arthritis (RA) is a systemic autoimmune disease which mainly affect joints. [1]. Macrophages often infiltrate in the inflammatory joints. Activated macrophages release TNF-α, IL-1β to accelerate tissue damage, is one of the most important targets for RA intervention. The traditional drugs currently used commonly have some disadvantages cannot be bypassed[2], while DNA nanostructure is a new type of drugs have precise design, and likewise takes biological effect together[3]. We synthesized a DNA tetrahedron loaded with MTX and conjugated with HA which targeted to macrophage.

Objectives:

To verify whether MTX-loading DNA tetrahedron can regulate the apoptosis and polarization of macrophage and finally improve the condition of CIA model mice by while decrease the side effect of MTX.

Methods:

DNA TET was synthesized by mixing signal strand DNA in TM buffer and heated to 95 °C for 10 min, then cooling to 4 °C. Electrophoresis was applied to confirm the formation of TET. The absorbance of MTX solution was detected by microplate reader to analyze the loading efficiency of MTX into TET. Fluorescence microscope was used to observe the intake of TET into cells. CCK8 experiment was applied to measure the vitality of cells. Flow cytometry was used to detect the apoptosis and polarization. CIA model was established based on DBA/1 mice. Mice were randomly divided into five groups: normal group injected with NS; after established CIA model, CIA group injected with NS, MTX group injected with MTX solution, MTX-TET group injected with MTX-TET NP.

Results:

We synthesized DNA tetrahedron(A) and used 8% PAGE electrophoresis to confirmed the successfully synthesis(B). Then We found that when TET concentration fixed, the loading MTX concentration gradually increased and saturated at 190μM(C). While completely loading needed at least 4 hours(D). Fluorescence showed that single DNA strand cannot be taken by RAW, while TET can be easily taken by RAW(E). CCK8 showed that empty TET had no obvious effect on cells, while MTX and MTX-TET with equivalent concentration can obviously suppress the vitality(F). Similarly, the apoptosis trial showed that TET can slightly decrease the apoptosis of RAW, MTX and MTX-TET can significantly promote the apoptosis(G). Flow cytometry showed that the MTX-TET can decrease the expression of M1 marker CD80 (H).

At last, we treat mice with NS, TET, MTX and MTX-TET once a week after CIA model established, and found that TET have no significantly effect on mice, while MTX and MTX-TET can alleviate the inflammation symptom of paws(I).

Conclusion:

Conclusions: We synthesized MTX-loading DNA tetrahedron conjugated with HA, and found that the MTX-TET NP have the excellent ability of promote RAW apoptosis and relieve proinflammatory M1 polarization. while also can alleviate the symptom of CIA mice.

References:

[1]Aletaha D, Smolen JS: Diagnosis and Management of Rheumatoid Arthritis: A Review. JAMA 2018, 320(13):1360-1372.

[2]Smolen JS, Aletaha D, McInnes IB: Rheumatoid arthritis. Lancet 2016, 388(10055):2023-2038.

[3]Hu Q, Li H, Wang L, Gu H, Fan C: DNA Nanotechnology-Enabled Drug Delivery Systems. Chem Rev 2019, 119(10):6459-6506.

Figure 1.

Disclosure of Interests:

None declared

OP0016 IDENTIFICATION OF FUNCTIONAL VARIANTS IN THE RHEUMATOID ARTHRITIS ASSOCIATED JAZF1 LOCUS IN SYNOVIAL FIBROBLASTS

Background:

Over the past decade, genome wide association studies (GWAS) have identified the JAZF1 locus as a risk locus for several autoimmune diseases, including rheumatoid arthritis (RA)1. However, the exact causal variants in the JAZF1 locus and their underlying regulatory events contributing to RA are still not known. Here, we focus on the effect of these variants on gene expression in synovial fibroblasts (SF).

Objectives:

To characterize the functional consequences of RA-causal variants in the JAZF1 locus in SF.

Methods:

Genetic fine-mapping of RA loci was conducted by computing sets of credible variants driving GWAS signals. These credible variant sets were integrated with DNA architecture (ChIP-seq), 3D chromatin interactions (3C, HiC and capture HiC), DNA accessibility (ATAC-seq) and gene expression (RNA-seq and CAGE-seq) datasets to select putative RA-causal variants in SF. Selected variants in the JAZF1 locus were tested for regulatory function by luciferase reporter assays and electrophoretic mobility shift assays (EMSA) in the fibrosarcoma cell line HT1080. The JASPAR2020 database was used to identify putative transcription factors (TF) binding to the selected variants. The expression of HOTTIP was measured by quantitative PCR in hand SF (n=23). Genotyping was done by pyrosequencing.

Results:

Genetic fine mapping revealed 47 variants in the JAZF1 locus. Integration of these variants with the chromatin datasets prioritized rs2158624, rs57585717 and rs186735625 as the top candidates (posterior probability of causality >0.1) in the JAZF1 locus. We found that rs2158624 and rs186735625 are located in the vicinity of enhancer elements in SF as determined by ATAC-seq. In addition, the region of rs2158624 exhibited strong chromatin interactions with the genomic region of HOTTIP and HOXA13. Both these transcripts were previously shown to be specifically expressed in SF isolated from hands and feet2. Based on this, we selected rs2158624 as the most promising candidate in the JAZF1 locus. We found that the rs2158624-C allele (risk) is associated with lower expression of HOTTIP, but not HOXA13, in hand SF compared to the rs2158624-T allele (non-risk) (p=0.02). Luciferase assays in HT1080 cells demonstrated enhancer activity with both the rs2158624-C allele (p=0.006) and T allele (p=0.04), with no significant difference in enhancer activity between the rs2158624-C and T allele. EMSAs identified stronger specific binding of HT1080-cell nuclear extract for the rs2158624-T allele than for the C allele (risk). Based on the JASPAR2020 database, we identified NFAT5 as a potential TF that can bind to rs2158624 and may regulate the expression of HOTTIP.

Conclusion:

We were able to substantially narrow down the potential functional variants in the JAZF1 locus using our data integration approach and functional assays. We suggest that the risk allele of rs2158624 influences the binding of TFs controlling the expression of the long non-coding RNA HOTTIP in SF, which might confer specific risk to develop RA in hands.

References:

[1]Okada Y et al. Genetic of rheumatoid arthritis contributes to biology and drug discovery. Nature 2014;506:376.

[2]Frank-Bertoncelj M et al. Epigenetically-driven anatomical diversity of synovial fibroblasts guides joint-specific fibroblast functions. Nat Commun 2017;8:14852.

Disclosure of Interests:

Miranda Houtman: None declared, Xiangyu Ge: None declared, Amanda McGovern: None declared, Kerstin Klein: None declared, Gisela Orozco: None declared, Mojca Frank Bertoncelj: None declared, Miriam Marks: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, iQone, Medscape, MSD, Novartis, Pfizer and Roche, Consultant of: Abbvie, Acceleron Pharma, Amgen, AnaMar, Arxx Therapeutics, Bayer, Baecon Discovery, Boehringer, CSL Behring, ChemomAb, Corbus Pharmaceuticals, Galapagos NV, GSK, Glenmark Pharmaceuticals, Horizon Pharmaceuticals, Inventiva, Italfarmaco, iQvia, Kymera, Lilly, Medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Pfizer, Roche, Roivant Sciences, Sanofi and UCB, Grant/research support from: Kymera Therapeutics and Mitsubishi Tanabe, Paul Martin: None declared, Stephen Eyre: None declared, Caroline Ospelt: None declared

Red Cell Distribution Width to Platelet Count Ratio: A Promising Routinely Available Indicator of Mortality for Acute Traumatic Brain Injury

Prognosis evaluation is crucial for the effective management of patients with acute traumatic brain injury (TBI). However, there is still a lack of routinely available blood indicators for mortality risk in clinical practice. To investigate whether blood red cell distribution width to platelet count ratio (RPR) correlates with hospital mortality of TBI, clinical data of 2220 patients with TBI were extracted from two large intensive care unit cohorts (MIMIC-III and eICU Database), and were integratively analyzed using our developed method named MeDICS. We found that higher RPR can be observed among non-survivors than survivors of TBI (p < 0.001). It had a moderately good prognostic performance for mortality with an area under receiver-operating characteristic curve (AUC) of 0.7367, which was greater than that of Glasgow Coma Scale (GCS; AUC = 0.6022). Besides, the nomogram consisting of RPR, GCS, and other risk factors was developed, where 10-fold cross-validation was performed to protect it against overfitting. A Harrell's C-index of 0.8523 was determined, suggesting an improved prognostic value based on RPR. The in vivo experiments further confirmed the association between RPR and neuro-outcome after TBI. It indicated that the continuous change in RPR post-injury is attributed to the development of inflammation, which emphasized the importance of controlling inflammatory response in clinical treatment. Taken together, RPR is a promising routinely available predictor of mortality for acute TBI. The nomogram generated from it can be used in resource-limited settings, thus be proposed as a prognosis evaluation aid for patients with TBI in all levels of medical system.

[Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway]

OBJECTIVE

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD).

OBJECTIVE

Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice.

OBJECTIVE

In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups.

OBJECTIVE

CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

Dl-3-n-butylphthalide regulates cholinergic dysfunction in chronic cerebral hypoperfusion rats

Objectives

To investigate whether dl-3-n-butylphthalide (NBP) affects cholinergic system function and ameliorates cognitive decline in a rat model of vascular dementia (VaD).

Methods

The VaD rat model was established by bilateral common carotid artery ligation (two-vessel occlusion, 2VO). Rats were divided into five groups: control, sham, 2VO, 2VO+NBP (80 mg/kg; intragastric), and 2VO+donepezil (1 mg/kg; intragastric). Treatments were administered once daily for 2 weeks from day 21 post-surgery. Spatial learning and memory were evaluated by Morris water maze performance. Hippocampal choline acetyltransferase (ChAT), acetylcholinesterase (AChE), vesicular acetylcholine transporter (VAChT), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) expressions were detected using immunohistochemistry, immunofluorescence, and real-time polymerase chain reaction methods.

Results

The daily escape latency was significantly longer in 2VO rats than in the sham or control groups, while the time spent in the target quadrant was significantly shorter. The daily escape latency of the 2VO+NBP group was significantly shorter compared with the 2VO group. Following NBP treatment, ChAT, AChE, VAChT, and BDNF expressions were significantly upregulated in the hippocampus.

Conclusions

Central cholinergic dysfunction may be involved in VaD pathogenesis. NBP treatment significantly improved spatial learning and memory in VaD rats, and may enhance cholinergic system function via BDNF-mediated neuroprotection.

Enhanced removal of Congo red dye from aqueous solution by surface modified activated carbon with bacteria

AIMS

The adsorption behaviour and mechanisms of the surface modified activated carbon with bacteria was evaluated.

METHODS AND RESULTS

16S rRNA was employed to identify the hydrocarbon-degrading bacteria. The bacteria was characterized by TEM and electron microscope. The surface modified activated carbon with bacteria was characterized by SEM. The adsorption behaviour was tested by static adsorption and dynamic adsorption.

CONCLUSION

The adsorption efficiency of the modified activated carbon was high when pH was weak acidic, and the adsorption capacity increased with the increase of temperature ranging from 20 to 35°C. The adsorption capacity peaked at 234·6 mg g^-1 at 25°C, which was sixfold higher than that of activated carbon. The pseudo-first-order kinetic can more accurately assess Congo red adsorption on the two adsorbents. The adsorption of Congo red by bacteria surface modified activated carbon fitted well with the Langmuir's model. The adsorption process was endothermic, and the biological floccules were formed during the adsorption. The physical adsorption is the main driving force.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results indicate that the bacteria surface-modified activated carbon can be used effectively as an adsorbent to eliminate Congo red from aqueous solutions.

A comparison between raltitrexed plus cisplatin and docetaxel plus cisplatin in concurrent chemoradiation for non-surgical esophageal squamous cell carcinoma

PURPOSE

Chemoradiotherapy (CRT) is considered as a standard treatment for unresectable and inoperable esophageal cancer (EC) patients. However, no consensus has been reached regarding the optimal synchronous chemotherapy regimen and the best combination of radiotherapy and chemotherapy. The aim of this study was to evaluate the efficacy and toxicity of raltitrexed plus cisplatin and docetaxel plus cisplatin to find a safe and effective concurrent chemotherapy schedule.

PATIENTS AND METHODS

Our retrospective study included 151 EC patients treated with raltitrexed and cisplatin (RP) (n=90) or docetaxel and cisplatin (DP) (n=61) from 2011 till 2018. Survival outcomes and treatment related toxicity were analyzed between the two groups.

RESULTS

PFS and OS were 18 and 34 months in the RP group, while 13 and 20 months in the DP group (P=0.118 and P=0.270). The 1-, 2-, 3-year survival rates of the RP group were 71.1, 55.4 and 46.4%. For the DP group, these were 63.9, 44.3 and 37.6%, respectively. Compared with DP group, RP group received a superior CR rate (68.9% versus 52.5%, P=0.041). There was a trend that the total number of toxic reactions in RP group was lower than that in DP group (P=0.058).

CONCLUSIONS

Even RP and DP groups have the similar survival outcomes and toxicity, raltitrexed/cisplatin get a higher complete response rate. Our study suggests that raltitrexed combined with cisplatin is a safe and effective concurrent chemotherapy regimen and it might be used as an alternative for cisplatin/5-FU and cisplatin/docetaxel in CCRT for EC patients.

Plasminogen improves lung lesions and hypoxemia in patients with COVID-19

BACKGROUND

Lungs from patients with coronavirus disease 2019 (COVID-19) have shown typical signs of acute respiratory distress syndrome (ARDS), formation of hyaline membrane mainly composed of fibrin and 'ground-glass' opacity. Previously, we showed plasminogen itself is a key regulator in fibrin degradation, wound healing and infection.

AIM

We aimed to investigate whether plasminogen can improve lung lesions and hypoxemia of COVID-19.

DESIGN

Thirteen clinically moderate, severe or critical COVID-19 patients were treated with atomization inhalation of freeze-dried plasminogen.

METHODS

Levels of their lung lesions, oxygen saturation and heart rates were compared before and after treatment by computed tomography scanning images and patient monitor.

RESULTS

After plasminogen inhalation, conditions of lung lesions in five clinically moderate patients have quickly improved, shown as the decreased range and density of 'ground glass' opacity. Improvements of oxygen saturation were observed in six clinically severe patients. In the two patients with critical conditions, the oxygen levels have significantly increased from 79-82% to 91% just about 1 h after the first inhalation. In 8 of 13 patients, the heart rates had slowed down. For the five clinically moderate patients, the difference is even statistically significant. Furthermore, a general relief of chest tightness was observed.

CONCLUSION

Whereas it is reported that plasminogen is dramatically increased in adults with ARDS, this study suggests that additional plasminogen may be effective and efficient in treating lung lesions and hypoxemia during COVID-19 infections. Although further studies are needed, this study highlights a possible hope of efficiently combating this rapid epidemic emergency.

Hydrogen improves cell viability partly through inhibition of autophagy and activation of PI3K/Akt/GSK3β signal pathway in a microvascular endothelial cell model of traumatic brain injury

Objective：Traumatic brain injury (TBI) is one of the most serious public health problems in the world. Hydrogen (H₂), a flammable, colorless, and odorless gas, has been observed to have preventive and therapeutic effects on brain trauma and other neurological disorders, but its exact mechanism has not been fully clarified.Methods: To further study the mechanism underlying the role of hydrogen gas in alleviating BBB damage after TBI, we performed the scratch injury model on cultured brain microvascular endothelial cells (bEnd.3), which formed the microvascular endothelial barrier - an integral part of the highly specialized BBB.Results: In the case of TBI, hydrogen was able to improve the decline of cell viability induced by TBI. More importantly, inhibition of PI3 K/Akt/GSK3β signal pathway or activation of autophagy reduced the protective effect of hydrogen on cell viability, indicating that such protective effect was regulated by PI3 K/Akt/GSK3β signal pathway and was related to the inhibition of autophagy.Conclusion: So we concluded that hydrogen improved the cell viability in a microvascular endothelial cell model of TBI partly through inhibition of autophagy, and inhibitory effect of hydrogen on autophagy was exerted by activating PI3 K/Akt/GSK3β signal pathway. These findings enriched our knowledge about the mechanism of hydrogen therapy against TBI.

Effect of reference region size on strain measurements using geometrical phase analysis

Geometrical phase analysis (GPA) is typically a powerful tool to investigate the deformation in high resolution transmission electron microscopy images and has been used in various fields. During GPA, strain components are calculated relative to an undistorted reference region. In the present work, the effect of reference region size on strain measurements has been investigated. Experimental measurements on a locally distorted gold nanoparticle exhibited that a small reference region below the GPA spatial resolution can introduce an inaccuracy in the measured displacement field, which appears as a significant increase in measured strains and severe fluctuation in phase images. The inaccuracy may be ascribed to an error of insufficient sampling. Our results suggest that a small reference region below the GPA spatial resolution should be avoided during GPA. This prerequisite should be paid more attention to during strain measurement on nanoparticles.

Subdural haematomas drain into the extracranial lymphatic system through the meningeal lymphatic vessels

Subdural haematomas (SDHs) are characterized by rapidly or gradually accumulated haematomas between the arachnoid and dura mater. The mechanism of haematoma clearance has not been clearly elucidated until now. The meningeal lymphatic vessel (mLV) drainage pathway is a novel system that takes part in the clearance of waste products in the central nervous system (CNS). This study aimed to explore the roles of the mLV drainage pathway in SDH clearance and its impacting factors. We injected FITC-500D, A488-fibrinogen and autologous blood into the subdural space of mice/rats and found that these substances drained into deep cervical lymph nodes (dCLNs). FITC-500D was also observed in the lymphatic vessels (LYVE+) of the meninges and the dCLNs in mice. The SDH clearance rate in SDH rats that received deep cervical lymph vessel (dCLV) ligation surgery was significantly lower than that in the control group, as evaluated by haemoglobin quantification and MRI scanning. The drainage rate of mLVs was significantly slower after the SDH model was established, and the expression of lymphangiogenesis-related proteins, including LYVE1, FOXC2 and VEGF-C, in meninges was downregulated. In summary, our findings proved that SDH was absorbed through the mLV drainage pathway and that haematomas could inhibit the function of mLVs.

Neuron-derived exosomes with high miR-21-5p expression promoted polarization of M1 microglia in culture

BACKGROUND

Neuroinflammation is a characteristic pathological change of acute neurological deficit and chronic traumatic encephalopathy (CTE) after traumatic brain injury (TBI). Microglia are the key cell involved in neuroinflammation and neuronal injury. The type of microglia polarization determines the direction of neuroinflammation. MiR-21-5p elevated in neurons and microglia after TBI in our previous research. In this study, we explore the influence of miR-21-5p for neuroinflammation by regulating microglia polarization.

METHODS

In this study, PC12 and BV2 used to instead of neuron and microglia respectively. The co-cultured transwell system used to simulate interaction of PC12 and BV2 cells in vivo environment.

RESULTS

We found that PC12-derived exosomes with containing miR-21-5p were phagocytosed by microglia and induced microglia polarization, meanwhile, the expression of miR-21-5p was increased in M1 microglia cells. Polarization of M1 microglia aggravated the release of neuroinflammation factors, inhibited the neurite outgrowth, increased accumulation of P-tau and promoted the apoptosis of PC12 cells, which formed a model of cyclic cumulative damage. Simultaneously, we also got similar results in vivo experiments.

CONCLUSIONS

PC12-derived exosomes with containing miR-21-5p is the essential of this cyclic cumulative damage model. Therefore, regulating the expression of miR-21-5p or the secretion of exosomes may be an important novel strategy for the treatment of neuroinflammation after TBI.

Increased Microglial Exosomal miR-124-3p Alleviates Neurodegeneration and Improves Cognitive Outcome after rmTBI

Repetitive mild traumatic brain injury (rmTBI) is considered to be an important risk factor for long-term neurodegenerative disorders such as Alzheimer's disease, which is characterized by β-amyloid abnormalities and impaired cognitive function. Microglial exosomes have been reported to be involved in the transportation, distribution, and clearance of β-amyloid in Alzheimer's disease. However, their impacts on the development of neurodegeneration after rmTBI are not yet known. The role of miRNAs in microglial exosomes on regulating post-traumatic neurodegeneration was investigated in the present study. We demonstrated that miR-124-3p level in microglial exosomes from injured brain was significantly altered in the acute, sub-acute, and chronic phases after rmTBI. In in vitro experiments, microglial exosomes with upregulated miR-124-3p (EXO-124) alleviated neurodegeneration in repetitive scratch-injured neurons. The effects were exerted by miR-124-3p targeting Rela, an inhibitory transcription factor of ApoE that promotes the β-amyloid proteolytic breakdown, thereby inhibiting β-amyloid abnormalities. In mice with rmTBI, the intravenously injected microglial exosomes were taken up by neurons in injured brain. Besides, miR-124-3p in the exosomes was transferred into hippocampal neurons and alleviated neurodegeneration by targeting the Rela/ApoE signaling pathway. Consequently, EXO-124 treatments improved the cognitive outcome after rmTBI, suggesting a promising therapeutic strategy for future clinical translation.

Integrated impedance bridge for absolute capacitance measurements at cryogenic temperatures and finite magnetic fields

We developed an impedance bridge that operates at cryogenic temperatures (down to 60 mK) and in perpendicular magnetic fields up to at least 12 T. This is achieved by mounting a GaAs HEMT amplifier perpendicular to a printed circuit board containing the device under test and thereby parallel to the magnetic field. The measured amplitude and phase of the output signal allows for the separation of the total impedance into an absolute capacitance and a resistance. Through a detailed noise characterization, we find that the best resolution is obtained when operating the HEMT amplifier at the highest gain. We obtained a resolution in the absolute capacitance of 6.4 aF/Hz at 77 K on a comb-drive actuator while maintaining a small excitation amplitude of 15 k_BT/e. We show the magnetic field functionality of our impedance bridge by measuring the quantum Hall plateaus of a top-gated hBN/graphene/hBN heterostructure at 60 mK with a probe signal of 12.8 k_BT/e.

Association of Fractional Flow on 3D-TOF-MRA with Cerebral Perfusion in Patients with MCA Stenosis

BACKGROUND AND PURPOSE

Fractional flow measured on 3D-TOF-MRA was proposed to quantify cerebral hemodynamic changes in patients with artery stenosis. We investigated the association between fractional flow and cerebral perfusion changes in patients with symptomatic MCA stenosis.

MATERIALS AND METHODS

This prospective study was approved by the institutional review board, and all participants provided written informed consent. From June 2015 to May 2018, four hundred twenty-nine patients with symptomatic intracranial arterial stenosis were consecutively recruited and underwent conventional brain MR imaging, 3D-TOF-MRA, and brain CTP. A total of 91 patients with unilateral M1 segment stenosis of the MCA and a stenosis degree of 50%∼99% were included in the analysis. Fractional flow was measured by comparing distal and proximal signal intensity changes across the stenosis on 3D-TOF-MRA. The cutoff value for fractional flow for discriminating between normal perfusion and hypoperfusion was obtained from the receiver operating characteristic curve. Associations between fractional flow and hypoperfusion were assessed using univariate and multivariate analyses.

RESULTS

The receiver operating characteristic curve showed a significant fractional flow threshold value at 0.90 (sensitivity, 70.1%; 95% CI, 55.9%-81.2%; specificity, 69.6%; 95% CI, 47.6%-84.1%). Participants with a fractional flow of ≤0.90 were independently associated with cerebral hypoperfusion downstream from the stenosis site (adjusted OR, 3.68; 95% CI, 1.63-11.62; P = .027).

CONCLUSIONS

Fractional flow measured on 3D-TOF-MRA may serve as a noninvasive and practical tool for determining the cerebral hypoperfusion in patents with symptomatic MCA stenosis.