Simultaneous ischemic regions targeting and BBB crossing strategy to harness extracellular vesicles for therapeutic delivery in ischemic stroke.

Extracellular vesicles (EVs) derived from adipose-derived stem cells (ADSC-EVs) hold great promise for ischemic stroke treatment, but their therapeutic efficacy is greatly limited due to insufficient targeting ability. Previous reports focused on single ischemic targeting or blood-brain barrier (BBB) penetration, precise delivery to the brain parenchyma has not been fully considered. This study leveraged the targeting ability of RGD peptide and the cell penetrating ability of Angiopep-2 peptide to deliver ADSC-EVs precisely to the impaired brain parenchyma. We found that dual-modified EVs (RA-EVs) significantly enhanced the transcellular permeability across BBB in vitro, and not only targeted ischemic blood vessels but also achieved rapid accumulation in the ischemic lesion area after intravenous administration in vivo. RA-EVs further decreased the infarct volume, apoptosis, BBB disruption, and neurobehavioral deficits. RNA sequencing revealed the molecular regulation mechanism after administration. These findings demonstrate that dual-modification optimizes brain parenchymal targeting and highlights the significance of recruitment and penetration as a previously unidentified strategy for harnessing EVs for therapeutic delivery in ischemic stroke.

Altered resting-state effective connectivity of trigeminal vascular system in migraine without aura: A spectral dynamic causal modeling study.

BACKGROUND: The trigeminal vascular system is an important part of the anatomical and physiological basis of migraine. The effective connectivity (EC) among the regions of interest (ROIs) in the trigeminal vascular system involved in migraine without aura (MWoA) remains unclear. METHODS: In this cross-sectional study, 48 patients (mean [SD] age 38.06 [10.35] years; male, 14/48 [29%]) with MWoA during the interictal phase and 48 healthy controls of similar age and sex (mean [SD] age 38.96 [10.96] years; male, 14/48 [29%]) underwent resting-state functional magnetic resonance imaging (fMRI). Dynamic causal modeling analysis was conducted to investigate directional EC among ROIs in the trigeminal vascular system including the bilateral brainstem, the primary somatosensory cortex (S1), the thalamus, and the insula. RESULTS: Compared with the healthy control group, MWoA represented significantly reduced EC from the left brainstem (Brainstem.L) to the left insula (MWoA: mean [SD] -0.16 [0.36]; healthy controls: mean [SD] 0.11 [0.41]; Pcorrected = 0.021), reduced EC from the Brainstem.L to the right insula (MWoA: mean [SD] -0.15 [0.39]; healthy controls: mean [SD] 0.03 [0.35]; Pcorrected = 0.021), and decreased EC from the left thalamus (Thalamus.L) to the Brainstem.L (MWoA: mean [SD] -0.13 [0.56]; healthy controls: mean [SD] 0.10 [0.45]; Pcorrected = 0.021). Altered EC parameters were not significantly correlated with MWoA clinical data. CONCLUSION: These results further provide increasing evidence that disturbed homeostasis of the trigeminovascular nociceptive pathway is involved in the pathophysiological mechanisms of migraine. Patients with MWoA exhibited a regional interaction distinct from healthy controls in the neural pathway of the Bilateral Insula-Brainstem.L-Thalamus.L, which may shed light on the future understanding of brain mechanisms for MWoA. Future brain-based interventions are suggested to consider the dysregulation in the Bilateral Insula-Brainstem.L-Thalamus.L circuits.

Microstructural Differences of the Cerebellum-Thalamus-Basal Ganglia-Limbic Cortex in Patients with Somatic Symptom Disorders: a Diffusion Kurtosis Imaging Study.

Somatic symp tom disorders (SSDs) are a group of psychiatric disorders characterized by persistent disproportionate concern and obsessive behaviors regarding physical conditions. Currently, SSDs lack effective treatments and their pathophysiology is unclear. In this paper, we aimed to examine microstructural abnormalities in the brains of patients with SSD using diffusion kurtosis imaging (DKI) and to investigate the correlation between these abnormalities and clinical indicators. Diffusion kurtosis images were acquired from 30 patients with SSD and 30 healthy controls (HCs). Whole-brain maps of multiple diffusion measures, including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), mean kurtosis (MK), radial kurtosis (RK), and axial kurtosis (AK), were calculated. To analyze differences between the two groups, nonparametric permutation testing with 10,000 randomized permutations and threshold-free cluster enhancement was used with family-wise error-corrected p values < 0.05 as the threshold for statistical significance. Then, the correlations between significant changes in these diffusion measures and clinical factors were examined. Compared to HCs, patients with SSD had significantly higher FA, MK, and RK and significantly lower MD and RD in the cerebellum, thalamus, basal ganglia, and limbic cortex. The FA in the left caudate and the pontine crossing tract were negatively correlated with disease duration; the MD and the RD in the genu of the corpus callosum were positively correlated with disease duration. Our findings highlight the role of the cerebellum-thalamus-basal ganglia-limbic cortex pathway, especially the cerebellum, in SSDs and enhance our understanding of the pathogenesis of SSDs.

MicroRNA-140-5p exacerbates vascular cognitive impairment by inhibiting neurogenesis in the adult mouse hippocampus after global cerebral ischemia.

Vascular cognitive impairment (VCI) is the most common type of dementia after Alzheimer's disease (AD). Effective treatments for VCI are currently lacking. MicroRNA (miR)- 140-5p is associated with cerebral ischemia and poststroke depression, but its relationship with VCI remains unknown. A VCI model was established by bilateral common carotid artery occlusion (BCCAO) for 17 min in mice. Neurogenesis was evaluated by immunostaining for Nestin/bromodeoxyuridine (BrdU), NeuN/BrdU, and doublecortin (DCX)/BrdU. Neuroplasticity was assessed by quantifying synapsin-I and postsynaptic density protein 95 (PSD-95) protein levels. Predicted target genes were screened and verified using the dual luciferase reporter gene system. MiR-140-5p was upregulated in the hippocampus of the BCCAO mice 2 weeks following ischemia. Compared with control groups, the AAV-miR-140-5p group exhibited poorer cognitive performance alongside lower numbers of DCX/BrdU and NeuN/BrdU and less synapsin-I and PSD-95 in the dentate gyrus (P < 0.05). MiR-140-5p overexpression decreased the predicted target gene Prox1. Dual luciferase reporter system confirmed that Prox1 was a direct target site for miR-140-5p. In conclusion, our results suggest that miR-140-5p inhibits neurogenesis and neuroplasticity via downregulation of Prox1 and aggravates VCI. Our findings highlight that miR-140-5p is involved in the pathological process of VCI and provides information for the development of new treatments, which may need further inhibition tests to verify.

Significant Structural Alterations and Functional Connectivity Alterations of Cerebellar Gray Matter in Patients With Somatic Symptom Disorder.

Objective: Recent studies have revealed a strong association between the cerebellum and psychiatric disorders. However, the structural changes in the cerebellar regions and functional connectivity (FC) patterns in patients with somatic symptom disorder (SSD) have not been elucidated. Methods: Thirty-seven patients with SSD (29 drug-naive and 8 medicated patients) and 37 sex- and age-matched healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging scans. The spatially unbiased infratentorial (SUIT) cerebellar atlas-based voxel-based morphometry was used to investigate the changes in cerebellar regional gray matter (GM). Seed-based FC was further computed to explore the pattern of abnormal FC across the whole brain. Correlations were calculated to investigate the relationship between cerebellar structural (and FC) changes and clinical characteristics. Results: After controlling for age, sex, total intracranial volume, medication, and mean FD covariates, all patients with SSD had increased mean GM volume (GMV) in the posterior lobules of the cerebellum bilaterally when compared with HCs, specifically, in the bilateral cerebellar crura I and II. Patients with SSD showed significantly stronger FC between the right crura I and II and bilateral precuneus inferior parietal region, and postcentral gyrus, extending to the superior parietal lobe, cingulate gyrus, and the white matter subgyral. In addition to the two clusters, right lingual gyrus was also a surviving cluster with significantly higher FC. Partial correlation analysis revealed that the degree of regional GMV increases in the two significant clusters and the Hamilton Depression Scale (HAMD) score was negatively correlated. Moreover, the FC of right crura I and II with the left parietal lobe and right lingual gyrus were also negatively associated with the HAMD score. Conclusions: SSD exhibited significant microstructural changes and changes in FC pattern in the posterior cerebellar lobe. These results shed new light on the psychological and neural substrates of SSD and may serve as a potential treatment target for SSD based on the cerebellar area.

Disrupted White Matter Functional Connectivity With the Cerebral Cortex in Migraine Patients.

Background: In attempts to understand the migraine patients' overall brain functional architecture, blood oxygenation level-dependent (BOLD) signals in the white matter (WM) and gray matter (GM) were considered in the current study. Migraine, a severe and multiphasic brain condition, is characterized by recurrent attacks of headaches. BOLD fluctuations in a resting state exhibit similar temporal and spectral profiles in both WM and GM. It is feasible to explore the functional interactions between WM tracts and GM regions in migraine. Methods: Forty-eight migraineurs without aura (MWoA) and 48 healthy controls underwent resting-state functional magnetic resonance imaging. Pearson's correlations between the mean time courses of 48 white matter (WM) bundles and 82 gray matter (GM) regions were computed for each subject. Two-sample t-tests were performed on the Pearson's correlation coefficients (CC) to compare the differences between the MWoA and healthy controls in the GM-averaged CC of each bundle and the WM-averaged CC of each GM region. Results: The MWoAs exhibited an overall decreased average temporal CC between BOLD signals in 82 GM regions and 48 WM bundles compared with healthy controls, while little was increased. In particular, WM bundles such as left anterior corona radiata, left external capsule and bilateral superior longitudinal fasciculus had significantly decreased mean CCs with GM in MWoA. On the other hand, 16 GM regions had significantly decreased mean CCs with WM in MWoA, including some areas that are parts of the somatosensory regions, auditory cortex, temporal areas, frontal areas, cingulate cortex, and parietal cortex. Conclusion: Decreased functional connections between WM bundles and GM regions might contribute to disrupted functional connectivity between the parts of the pain processing pathway in MWoAs, which indicated that functional and connectivity abnormalities in cortical regions may not be limited to GM regions but are instead associated with functional abnormalities in WM tracts.

MicroRNA-210-3p Targets RGMA to Enhance the Angiogenic Functions of Endothelial Progenitor Cells Under Hypoxic Conditions.

Endothelial progenitor cells (EPCs) are multipotential stem cells considered to have immense clinical value for revascularization. However, the clinical application of EPCs has been hampered by their clinical potency in ischemic anoxic environments. This study aimed to explore the effect of microRNA-210 (miR-210) on EPCs under oxygen-glucose deprivation (OGD) conditions. We generated a model of EPCs cultured under OGD conditions to simulate ischemia and explore the expression of miR-210 in vitro. With longer exposure to hypoxia, we found that miR-210-3p expression was highly upregulated in OGD groups compared to that in controls from 4 to 24 h, but not miR-210-5p. We then transfected a miR-210-3p mimic and inhibitor into EPCs, and after 24 h, we exposed them to OGD conditions for 4 h to simulate ischemia. We detected miR-210 by real-time polymerase chain reaction (RT-PCR) and tested the proliferation, migration, and tube formation of normal EPCs and OGD-treated EPCs by CCK-8, transwell chamber, and Matrigel assays, respectively. The direct targets of miR-210-3p were predicted using miRWalk. Compared to that in normal EPCs, higher miR-210-3p expression was found in OGD-treated EPCs (p < 0.05). Moreover, upregulation of miR-210-3p was found to promote proliferation, migration, and tube formation in EPCs under normal and OGD conditions (p < 0.05), whereas down-regulation inhibited these abilities in OGD-treated EPCs (p < 0.05). Repulsive guidance molecule A (RGMA), a negative regulator of angiogenesis, was predicted to be a target of miR-210-3p. Accordingly, upregulation of miR-210-3p was found to inhibit its expression at the protein level in OGD-treated EPCs, whereas downregulation of miR-210-3p inhibited its expression (p < 0.05). A dual-luciferase reporter system confirmed that RGMA is a direct target of miR-210-3p. MicroRNA-210-3p overexpression enhances the angiogenic properties of OGD-treated EPCs by inhibiting RGMA.

L-glutamine protects mouse brain from ischemic injury via up-regulating heat shock protein 70.

INTRODUCTION: L-glutamine is an antioxidant that plays a role in a variety of biochemical processes. Given that oxidative stress is a key component of stroke pathology, the potential of L-glutamine in the treatment of ischemic stroke is worth exploring. AIMS: In this study, we investigated the effect and mechanisms of action of L-glutamine after cerebral ischemic injury. RESULTS: L-glutamine reduced brain infarct volume and promoted neurobehavioral recovery in mice. L-glutamine administration increased the expression of heat-shock protein 70 (HSP70) in astrocytes and endothelial cells. Such effects were abolished by the coadministration of Apoptozole, an inhibitor of the ATPase activity of HSP70. L-glutamine also reduced oxidative stress and neuronal apoptosis, and increased the level of superoxide dismutase, glutathione, and brain-derived neurotrophic factor. Cotreatment with Apoptozole abolished these effects. Cell culture study further revealed that the conditioned medium from astrocytes cultured with L-glutamine reduced the apoptosis of neurons after oxygen-glucose deprivation. CONCLUSION: L-glutamine attenuated ischemic brain injury and promoted functional recovery via HSP70, suggesting its potential in ischemic stroke therapy.

MicroRNA-140-5p: A novel circulating biomarker for early warning of late-onset post-stroke depression.

We aimed to explore the circulating microRNAs biomarkers in the acute stage following cerebral ischemia to earlier warn late-onset post-stroke depression (PSD). A total of 251 consecutive patients with acute ischemic stroke were recruited. They were divided into three groups depending on whether PSD had occurred at 2 weeks or 3 months since stroke: early-onset PSD, late-onset PSD, and non-depressed group. Microarray assay was conducted to identify the different expression profiles of plasma miRNAs. Comprehensive bioinformatics analysis for their integrating putative target genes was performed. The key miRNA was validated in a larger cohort and its function was further studied in ischemic mice brain. We screened three differentially expressed miRNAs in the late-onset PSD individuals, miR-140-5p and miR-221-3p were significantly upregulated while miR-1246 was downregulated. The bioinformatics analysis demonstrated that their predicted target genes were mainly enriched in axon development and Ras signaling pathway. Logistic regression analysis revealed that miR-140-5p was an independent risk factor for late-onset PSD (P = 0.017, OR = 2.313, 95%CI 1.158 to 4.617). The miR-140-5p expression on admission was significantly positively correlated with HDRS scores assessed at 3 months after stroke (P = 0.0007). The predictive value of miR-140-5p for late-onset PSD is 83.3% sensitivity and 72.6% specificity (AUC = 0.8127, P < 0.0001). AAV-mediated overexpression of miR-140-5p decreased the protein level of IL1rap, IL1rapl1, VEGF, and MEGF10 in the ischemic mouse hippocampus and inhibited neurogenesis and capillary density. MiR-140-5p might be involved in the pathogenesis of late-onset PSD and used as a novel early warning biomarker.

Blood microRNA-15a Correlates with IL-6, IGF-1 and Acute Cerebral Ischemia.

OBJECTIVE: This study aims to explore the function of blood microRNA-15a (miR-15a) in the pathogenesis of acute cerebral ischemia (AIS). METHODS: Blood samples were collected from healthy control and AIS patients within 72 h after onset. A model of ischemia in human umbilical vein endothelial cells (HUVECs) was established through oxygen and glucose deprivation (OGD). MiR-15a in patients and in cells was measured using real-time quantitative polymerase chain reaction (qPCR). The predicted target of miR-15a such as interleukin-6 (IL-6) and insulin-like growth factors-1 (IGF-1) in plasma was detected by enzyme-linked immunosorbent assay (ELISA). The relations between blood miR-15a and stroke severity, stroke etiology, infarct location, stroke prognosis, predicted targets were analyzed by Statistical Product and Service Solutions (SPSS) software respectively. RESULTS: Higher miR-15a levels were found in AIS patients and ischemic cells within 72 h, compared to control (p < 0.05). Receiver Operating Characteristic (ROC) analysis showed that blood miR-15a predicted stroke onset with 98.67% specificity. Blood miR-15a had a negative correlation with National Institutes of Health Stroke Scale (NIHSS) scores (r = -0.3695, p < 0.01). The AIS patients with increased miR-15a levels had a better prognosis. MiR-15a was up-regulated in anterior circulation infarction and small-artery atherosclerosis stroke. Plasma levels of IL-6 and IGF-1 were associated with blood miR-15a (r = -0.6051, 0.3231, p < 0.05, respectively). CONCLUSION: Blood miR-15a associates with IL-6, IGF-1 and acute cerebral ischemia. It could serve as a potential diagnostic biomarker and therapeutic target for stroke.

Age-Related Frontal Periventricular White Matter Hyperintensities and miR-92a-3p Are Associated with Early-Onset Post-Stroke Depression.

Objective: To explore the correlationship among white matter hyperintensities (WMHs), miR-92a-3p and early-onset post-stroke depression (PSD). Methods: We recruited consecutively 238 patients with acute cerebral infarction and MRI examination in the Department of neurology, Ruijin hospital, Shanghai Jiaotong University School of Medicine. The diagnosis of early-onset PSD was made in accordance with DSM-IV criteria for depression in 2 weeks after stroke. Clinical information and assessments of stroke severity were recorded on admission. The analysis of plasma miR-92a-3p was performed using quantitative PCR at the same time. WMHs were evaluated by the Fazekas and Scheltens visual rating scales. The relationship among WMHs, miR-92a-3p and PSD were analyzed by SPSS 22.0 software. Results: Logistic regression demonstrated that periventricular WMHs (PVWMHs) in frontal caps was an independent risk factor with early-onset PSD (OR = 1.579, 95% CI: 1.040-2.397, p = 0.032). The age and numbers of lacunes were related to frontal PVWMHs. Plasma miR-92a-3p in the PSD group was higher compared with the non-depressed group. Receiver operating curve analysis revealed that miR-92a-3p could predict early-onset PSD with 90% sensitivity and 90% specificity. The higher miR-92a-3p trended toward association with greater frontal PVWMHs. Conclusion: Acute ischemic stroke patients with frontal PVWMHs or a high plasma miR-92a-3p at baseline were more likely to develop early-onset PSD. MiR-92a-3p might be involved in the white matter impairment and post-stroke depression.

Diabetes mellitus is associated with late-onset post-stroke depression.

OBJECTIVE: To explore the associated factors of late-onset post-stroke depression (PSD). METHODS: A total of 251 patients with acute ischemic stroke were recruited. The evaluation of depression was performed 2 weeks after ischemia. 206 patients showing no depression in 2 weeks were followed up. They were divided into late-onset PSD group and non-depressed group by clinical interview with Hamilton depression scale score 3 months after stroke. On the first day following hospitalization, the clinical data including age, gender, educational level and vascular risk factors were recorded. The severity, etiological subtype and location of stroke were evaluated. The inflammatory mediators, glucose and lipid levels were recorded on the day of admission. The association between clinical factors and late-onset PSD was explored by logistic regression analysis. The ROC analysis was performed to evaluate the predicting power of the clinical factors. RESULTS: 187 of 206 patients completed the assessment 3 months after stroke. 19 (10.16%) patients were diagnosed as late onset PSD. Diabetes mellitus was an independent risk factor for late-onset PSD (OR 2.675, p = 0.047). ROC analysis demonstrated that glucose and HbA1C could predict late-onset PSD with specificity of 84.4%. LIMITATIONS: The sample of our study was small. The results should be further confirmed in a larger cohort of patients with acute ischemic stroke. CONCLUSIONS: The acute ischemic stroke patients with diabetes mellitus were more tendered to suffer late-onset PSD.