Sex-specific effects of alcohol on neurobehavioral performance and endoplasmic reticulum stress: an analysis using neuron-specific MANF deficient mice.

Excessive alcohol exposure can cause neurobehavioral deficits and structural alterations in the brain. Emerging research evidence suggests that endoplasmic reticulum (ER) stress plays an important role in alcohol-induced neurotoxicity. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress inducible protein and is responsible to maintain ER homeostasis. MANF is highly expressed in both the developing and mature brain. We have previously shown that MANF deficiency exacerbated alcohol induced neurodegeneration and ER stress in the developing brain. However, little is known regarding the role of MANF in alcohol induced neuronal damage in the adult brain. In this study, we used a neuron-specific MANF knockout (KO) mouse model to investigate the effect of MANF deficiency on acute binge alcohol exposure-induced neurobehavioral deficits and ER stress. Adult male and female MANF KO mice and littermate controls received daily alcohol gavage (5 g/kg) for 10 days and then subjected to a battery of neurobehavioral tests including rotarods, balance beam, DigiGait, open field, elevated plus maze, Barnes maze, and three-chamber sociability task. Female MANF KO animals were more susceptible to alcohol-induced body weight loss. Alcohol exposure did not affect motor function, however female but not male MANF KO mice exhibited an increased locomotor activity in open field test. Learning and memory was not significantly impaired, but it was altered by MANF deficiency in females while it was affected by alcohol treatment in males. Both alcohol-exposed male and female MANF KO mice displayed increased sociability. Alcohol induced the expression of ER chaperones GRP78 and GRP94 and altered the levels of several unfolded protein response (UPR) and neuroinflammation markers in MANF KO mice in a sex-specific manner. The expression of MANF interacting proteins neuroplastin, PDIA1, and PDIA6 was increased in MANF KO mice, and was further induced by alcohol. In conclusion, alcohol exposure and neuronal MANF deficiency interacted to alter neurobehavioral outcomes, ER homeostasis and neuroinflammation in a sex-specific manner.

A Predictive Model of the Progression to Alzheimer's Disease in Patients with Mild Cognitive Impairment Based on the MRI Enlarged Perivascular Spaces.

Background: Mild cognitive impairment (MCI) is a heterogeneous condition that can precede various forms of dementia, including Alzheimer's disease (AD). Identifying MCI subjects who are at high risk of progressing to AD is of major clinical relevance. Enlarged perivascular spaces (EPVS) on MRI are linked to cognitive decline, but their predictive value for MCI to AD progression is unclear. Objective: This study aims to assess the predictive value of EPVS for MCI to AD progression and develop a predictive model combining EPVS grading with clinical and laboratory data to estimate conversion risk. Methods: We analyzed 358 patients with MCI from the ADNI database, consisting of 177 MCI-AD converters and 181 non-converters. The data collected included demographic information, imaging data (including perivascular spaces grade), clinical assessments, and laboratory test results. Variable selection was conducted using the Least Absolute Shrinkage and Selection Operator (LASSO) method, followed by logistic regression to develop predictive model. Results: In the univariate logistic regression analysis, both moderate (OR = 5.54, 95% CI [3.04-10.18]) and severe (OR = 25.04, 95% CI [10.07-62.23]) enlargements of the centrum semiovale perivascular space (CSO-PVS) were found to be strong predictors of disease progression. LASSO analyses yielded 12 variables, refined to six in the final model: APOE4 genotype, ADAS11 score, CSO-PVS grade, and volumes of entorhinal, fusiform, and midtemporal regions, with an AUC of 0.956 in the training and 0.912 in the validation cohort. Conclusions: Our predictive model, emphasizing EPVS assessment, provides clinicians with a practical tool for early detection and management of AD risk in MCI patients.

TLR4/Rac1/NLRP3 Pathway Mediates Amyloid-ß-Induced Neuroinflammation in Alzheimer's Disease.

Background: Neuroinflammation plays a crucial part in the initial onset and progression of Alzheimer's disease (AD). NLRP3 inflammasome was demonstrated to get involved in amyloid-ß (Aß)-induced neuroinflammation. However, the mechanism of Aß-triggered activation of NLRP3 inflammasome remains poorly understood. Objective: Based on our previous data, the study aimed to identify the downstream signals that bridge the activation of TLR4 and NLRP3 inflammasome associated with Aß. Methods: BV-2 cells were transfected with TLR4siRNA or pretreated with a CLI-095 or NSC23766, followed by Aß1-42 treatment. APP/PS1 mice were injected intraperitoneally with CLI-095 or NSC23766. NLRP3 inflammasome and microglia activation was detected with immunostaining and western blot. G-LISA and Rac1 pull-down activation test were performed to investigate the activation of Rac1. Real-time PCR and ELISA were used to detect the inflammatory cytokines. Aß plaques were assessed by western blotting and immunofluorescence staining. Morris water maze test was conducted to determine the spatial memory in mice. Results: Rac1 and NLRP3 inflammasome were activated by Aß in both in vitro and in vivo experiments. Inhibition of TLR4 reduced the activity of Rac1 and NLRP3 inflammasome induced by Aß1-42. Furthermore, inhibition of Rac1 blocked NLRP3 inflammasome activation mediated by TLR4. Blocking the pathway by CLI095 or NSC23766 suppressed Aß1-42-triggered activation of microglia, reduced the expression of pro-inflammatory mediators and ameliorated the cognition deficits in APP/PS1 mice. Conclusions: Our study demonstrated that TLR4/Rac1/NLRP3 pathway mediated Aß-induced neuroinflammation, which unveiled a novel pathway and key contributors underlying the pathogenic mechanism of Aß.

DMT1 ubiquitination by Nedd4 protects against ferroptosis after intracerebral hemorrhage.

OBJECTIVE: Neuronal precursor cells expressed developmentally down-regulated 4 (Nedd4) are believed to play a critical role in promoting the degradation of substrate proteins and are involved in numerous biological processes. However, the role of Nedd4 in intracerebral hemorrhage (ICH) remains unknown. This study aims to investigate the regulatory role of Nedd4 in the ICH model. METHODS: Male C57BL/6J mice were induced with ICH. Subsequently, the levels of glutathione peroxidase 4 (GPX4), malondialdehyde (MDA) concentration, iron content, mitochondrial morphology, as well as the expression of divalent metal transporter 1 (DMT1) and Nedd4 were assessed after ICH. Furthermore, the impact of Nedd4 overexpression was evaluated through analyses of hematoma area, ferroptosis, and neurobehavioral function. The mechanism underlying Nedd4-mediated degradation of DMT1 was elecidated using immunoprecipitation (IP) after ICH. RESULTS: Upon ICH, the level of DMT1 in the brain increased, but decreased when Nedd4 was overexpressed using Lentivirus, suggesting a negative correlation between Nedd4 and DMT1. Additionally, the degradation of DMT1 was inhibited after ICH. Furthermore, it was found that Nedd4 can interact with and ubiquitinate DMT1 at lysine residues 6, 69, and 277, facilitating the degradation of DMT1. Functional analysis indicated that overexpression of Nedd4 can alleviate ferroptosis and promote recovery following ICH. CONCLUSION: The results demonstrated that ferroptosis occurs via the Nedd4/DMT1 pathway during ICH, suggesting it potential as a valuable target to inhibit ferroptosis for the treatment of ICH.

Circular RNA PTP4A2 regulates microglial polarization through STAT3 to promote neuroinflammation in ischemic stroke.

OBJECTIVE: Microglial polarization plays a critical role in neuroinflammation and may be a potential therapeutic target for ischemic stroke. This study was to explore the role and underlying molecular mechanism of Circular RNA PTP4A2 (circPTP4A2) in microglial polarization after ischemic stroke. METHODS: C57BL/6J mice underwent transient middle cerebral artery occlusion (tMCAO), while primary mouse microglia and BV2 microglial cells experienced oxygen glucose deprivation/reperfusion (OGD/R) to mimic ischemic conditions. CircPTP4A2 shRNA lentivirus and Colivelin were used to knock down circPTP4A2 and upregulate signal transducer and activator of transcription 3 (STAT3) phosphorylation, respectively. Microglial polarization was assessed using immunofluorescence staining and Western blot. RNA pull-down and RNA binding protein immunoprecipitation (RIP) were applied to detect the binding between circPTP4A2 and STAT3. RESULTS: The levels of circPTP4A2 were significantly increased in plasma and peri-infarct cortex in tMCAO mice. CircPTP4A2 knockdown reduced infarct volume, increased cortical cerebral blood flow (CBF), and attenuated neurological deficits. It also decreased pro-inflammatory factors levels in peri-infarct cortex and plasma, and increased anti-inflammatory factors concentrations 24 h post-stroke. In addition, circPTP4A2 knockdown suppressed M1 microglial polarization and promoted M2 microglial polarization in both tMCAO mice and OGD/R-induced BV2 microglial cells. Moreover, circPTP4A2 knockdown inhibited the phosphorylation of STAT3 induced by oxygen-glucose deprivation. In contrast, increased phosphorylation of STAT3 partly counteracted the effects of circPTP4A2 knockdown. RNA pull-down and RIP assays further certified the binding between circPTP4A2 and STAT3. CONCLUSION: These results revealed regulatory mechanisms of circPTP4A2 that stimulated neuroinflammation by driving STAT3-dependent microglial polarization in ischemic brain injury. CircPTP4A2 knockdown reduced cerebral ischemic injury and promoted microglial M2 polarization, which could be a novel therapeutic target for ischemic stroke.

Remote limb ischemic postconditioning inhibits microglia pyroptosis by modulating HGF after acute ischemia stroke.

The repetitive inflation-deflation of a blood pressure cuff on a limb is known as remote limb ischemic postconditioning (RIPostC). It prevents brain damage induced by acute ischemia stroke (AIS). Pyroptosis, executed by the pore-forming protein gasdermin D (GSDMD), is a type of regulated cell death triggered by proinflammatory signals. It contributes to the pathogenesis of ischemic brain injury. However, the effects of RIPostC on pyroptosis following AIS remain largely unknown. In our study, linear correlation analysis confirmed that serum GSDMD levels in AIS patients upon admission were positively correlated with NIHSS scores. RIPostC treatment significantly reduced GSDMD level compared with patients without RIPostC at 3 days post-treatment. Besides, middle cerebral artery occlusion (MCAO) surgery was performed on C57BL/6 male mice and RIPostC was induced immediately after MCAO. We found that RIPostC suppressed the activation of NLRP3 inflammasome to reduce the maturation of GSDMD, leading to decreased pyroptosis in microglia after AIS. Hepatocyte growth factor (HGF) was identified using the high throughput screening. Importantly, HGF siRNA, exogenous HGF, and ISG15 siRNA were used to reveal that HGF/ISG15 is a possible mechanism of RIPostC regulation in vivo and in vitro.

Upregulation of mesencephalic astrocyte-derived neurotrophic factor (MANF) expression offers protection against alcohol neurotoxicity.

Alcohol exposure has detrimental effects on both the developing and mature brain. Endoplasmic reticulum (ER) stress is one of the mechanisms that contributes to alcohol-induced neuronal damages. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-responsive protein and is neuroprotective in multiple neuronal injury and neurodegenerative disease models. MANF deficiency has been shown to exacerbate alcohol-induced ER stress and neurodegeneration. However, it is unknown whether MANF supplement is sufficient to protect against alcohol neurotoxicity. Alcohol alters MANF expression in the brain, but the mechanisms underlying alcohol modulation of MANF expression remain unclear. This study was designed to determine how alcohol alters MANF expression in neuronal cells and whether exogeneous MANF can alleviate alcohol neurotoxicity. We showed that alcohol increased MANF transcription and secretion without affecting MANF mRNA stability and protein degradation. ER stress was necessary for alcohol-induced MANF upregulation, as pharmacological inhibition of ER stress by 4-PBA diminished alcohol-induced MANF expression. In addition, the presence of ER stress response element II (ERSE-II) was required for alcohol-stimulated MANF transcription. Mutations or deletion of this sequence abolished alcohol-regulated transcriptional activity. We generated MANF knockout (KO) neuronal cells using CRISPR/Cas9. MANF KO cells exhibited increased unfolded protein response (UPR) and were more susceptible to alcohol-induced cell death. On the other hand, MANF upregulation by the addition of recombinant MANF protein or adenovirus gene transduction protected neuronal cells against alcohol-induced cell death. Further studies using early postnatal mouse pups demonstrated that enhanced MANF expression in the brain by intracerebroventricular (ICV) injection of MANF adeno-associated viruses ameliorated alcohol-induced cell death. Thus, alcohol increased MANF expression through inducing ER stress, which could be a protective response. Exogenous MANF was able to protect against alcohol-induced neurodegeneration.

Increased plasma levels of circPTP4A2 and circTLK2 are associated with stroke injury.

OBJECTIVE: Accumulating studies have shown that circulating circular RNAs (circRNAs) represent novel biomarkers for many human diseases. We investigated whether plasma circPTP4A2 and circTLK2 levels are associated with stroke severity, infarct volume, stroke etiology, and functional outcome in acute ischemic stroke (AIS) patients. METHODS: We applied quantitative real-time PCR (qPCR) to measure plasma circPTP4A2 and circTLK2 levels of 236 AIS patients within 72 h of symptoms onset and 136 healthy controls. We further assessed the National Institutes of Health Stroke Scale (NIHSS), infarct size, the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification and the 90-day modified Rankin scale (mRS) for each patient. RESULTS: At admission, plasma circPTP4A2 and circTLK2 levels in patients with moderate to severe stroke were significantly higher compared to those with mild stroke. Logistic regression and receiver-operating characteristic (ROC) curve analyses indicated that they might function as predictive biomarkers for moderate to severe stroke. We also observed a medium positive correlation between these two circRNAs and NIHSS. Plasma circPTP4A2 and circTLK2 levels were slight positively correlated with cerebral infarct volume only in anterior circulation infarction (ACI) patients. Levels of both circPTP4A2 and circTLK2 were closely related with large artery atherosclerosis (LAA) stroke. Moreover, changes within 7 days after admission in circPTP4A2 and circTLK2 were able to predict unfavorable clinical outcome 90 days after AIS. INTERPRETATION: These results demonstrate that plasma circPTP4A2 and circTLK2 strongly correlated with severity, subtypes and prognosis of AIS, and they could serve as promising biomarkers.

Early activation of Toll-like receptor-3 reduces the pathological progression of Alzheimer's disease in APP/PS1 mouse.

BACKGROUND: Toll-like receptor 3 (TLR3) plays an important role in the immune/inflammatory response in the nervous system and is a main pathological feature of Alzheimer's disease (AD). This study investigates the role of early activation of TLR3 in the pathophysiological process of AD. METHODS: In the experiment, the agonist of TLR3, Poly(I:C), was intraperitoneally injected into the APP/PS1 mouse model of AD and wild-type control mice starting from the age of 4 to 9 months. At the age of 14 months, behavioral tests were conducted. Western blot and immunohistochemistry staining were used to evaluate the level of amyloid ß-protein (Aß), the activation of inflammatory cells, and neuron loss. In addition, the levels of inflammatory cytokines were measured using a quantitative polymerase chain reaction. RESULTS: The results demonstrated that the early activation of TLR3 attenuated neuronal loss and neurobehavioral dysfunction. Moreover, the early activation of TLR3 reduced Aß deposition, inhibited the activation of microglia and astrocytes, and decreased the transcription of pro-inflammatory factors in the hippocampus. CONCLUSIONS: The results indicated that the activation of TLR3 by Poly (I:C) in the early stage of development of AD in a mouse model attenuated neuron loss and improved neurobehavioral functions. The underlying mechanisms could be attributed to its role in Aß clearance, the inhibition of glial cells, and the regulation of neuroinflammation in the hippocampus.

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A full-term female infant was admitted at 5 hours after birth due to heart malformations found during the fetal period and cyanosis once after birth. Mmultiple malformations of eyes, face, limbs, and heart were noted. The whole-exome sequencing revealed a pathogenic heterozygous mutation, c.2428C>T(p.Arg810*), in the BCOR gene. The infant was then diagnosed with oculo-facio-cardio-dental syndrome. He received assisted ventilation to improve oxygenation and nutritional support during hospitalization. Right ventricular double outlet correction was performed 1 month after birth. Ocular lesions were followed up and scheduled for elective surgery. The possibility of oculo-facio-cardio-dental syndrome should be considered for neonates with multiple malformations of eyes, face, and heart, and genetic testing should be performed as early as possible to confirm the diagnosis; meanwhile, active ophthalmic and cardiovascular symptomatic treatment should be given to improve the prognosis.

Analysis of Risk Factors for Cerebral Microbleeds and the Relationship between Cerebral Microbleeds and Cognitive Impairment.

(1) Background: Cerebral microbleeds (CMBs) are attracting increasing attention. Nevertheless, the risk factors for CMBs remain poorly identified, and the relationship between CMBs and cognitive impairment is still up for debate; (2) Objective: The present study analyzed the risk factors for CMBs and probed into the potential correlations between the presence, number, and location of CMBs and cognition; (3) Methods: This study enrolled 406 subjects who underwent both brain 3.0-T magnetic resonance imaging scans and cognitive testing. Spearman correlation was used to assess the relationship between the number of CMBs and cognition. Multiple linear regression was utilized to analyze the relationship between the regions of CMBs and each cognitive domain; (4) Results: Multivariate logistic regression analysis results showed that age (odds ratio (OR) = 1.045, 95% confidence interval (95%CI; 1.009, 1.082)), smoking (OR = 3.604, 95%CI (1.995, 6.509)), hypertension (OR = 3.607, 95%CI (2.204, 5.901)), total cholesterol (OR = 0.611, 95%CI (0.467, 0.799)), and Amyloid-ß1-42 (Aß1-42) (OR = 1.028, 95%CI (1.018, 1.037)) were the influencing factors of CMBs. Education years (OR = 0.959, 95%CI (0.930, 0.988)), white matter lesions (OR = 2.687, 95%CI (1.782, 4.051)), and CMBs (OR = 21.246, 95%CI (5.728, 21.576)) were the risk factors for cognitive impairment. Hypertension increased the probability of deep CMBs (OR = 12.54, 95%CI (2.21, 71.28)), while Aß1-42 elevated the probability of lobar CMBs (OR = 1.02, 95%CI (1.00, 1.03)). There was a linear correlation between the number of CMBs and Montreal Cognitive Assessment scores (r = −0.756, p < 0.001). However, CMBs in each region were not related to specific cognitive domains (p > 0.05), except CMBs in the mixed group that were negatively correlated with attention (OR = −0.669, 95%CI (−0.034, −5.270)); (5) Conclusions: Taken together, serum Aß1-42 levels are related to the presence of CMBs. Cognitive impairment is correlated with the number of CMBs rather than their region. These findings suggest that CMBs play a role in cognitive impairment and that CMBs mark the presence of diffuse vascular injury and neurodegenerative brain damage.

Functional MRI in Parkinson's disease with freezing of gait: a systematic review of the literature.

BACKGROUND: Freezing of gait (FOG), a common and disabling symptom of Parkinson's disease (PD), is characterized by an episodic inability to generate effective stepping. Functional MRI (fMRI) has been used to evaluate abnormal brain connectivity patterns at rest and brain activation patterns during specific tasks in patients with PD-FOG. This review has examined the existing functional neuroimaging literature in PD-FOG, including those with treatment. Summarizing these articles provides an opportunity for a better understanding of the underlying pathophysiology in PD-FOG. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a literature review of studies using fMRI to investigate the underlying pathophysiological mechanisms of PD-FOG. RESULTS: We initially identified 201 documents. After excluding the duplicates, reviews, and other irrelevant articles, 39 articles were finally identified, including 18 task-based fMRI studies and 21 resting-state fMRI studies. CONCLUSIONS: Studies using fMRI techniques to evaluate PD-FOG have found dysfunctional connectivity in widespread cortical and subcortical regions. Standardized imaging protocols and detailed subtypes of PD-FOG are furthered required to elucidate current findings.

Toll-like receptor-2 gene knockout results in neurobehavioral dysfunctions and multiple brain structural and functional abnormalities in mice.

OBJECTIVE: Toll-like receptor-2 (TLR2), a member of TLR family, plays an important role in the induction and regulation of immune/inflammation. TLR2 gene knockout (TLR2KO) mice have been widely used for animal models of neurological diseases. Since there is close relationship between immune system and neurobehavioral functions, it is important to clarify the exact role of TLR2 defect itself in neurobehavioral functions. The present study aimed to investigate the effect of TLR2KO on neurobehavioral functions in mice and the mechanisms underlying the observed changes. METHODS: Male TLR2KO and wild type (WT) mice aged 3, 7, and 12 months were used for neurobehavioral testing and detection of protein expression by Western blot. Brain magnetic resonance imaging (MRI), electrophysiological recording, and Evans blue (EB) assay were applied to evaluate regional cerebral blood flow (rCBF), synaptic function, and blood-brain barrier (BBB) integrity in 12-month-old TLR2KO and age-matched WT mice. RESULTS: Compared to WT mice, TLR2KO mice showed decreased cognitive function and locomotor activity, as well as increased anxiety, which developed from middle age (before 7-month-old) to old age. In addition, significantly reduced regional cerebral blood flow (rCBF), inhibited long-term potentiation (LTP), and increased blood-brain barrier (BBB) permeability were observed in 12-month-old TLR2KO mice. Furthermore, compared with age-matched WT mice, significant reduction in protein levels of tight junction proteins (ZO-1, Occludin, and Claudin-5) and increased neurofilament protein (SMI32) were observed in 7 and 12-month-old TLR2KO mice, and that myelin basic protein (MBP) decreased in 12-month-old TLR2KO mice. CONCLUSION: Our data demonstrated that TLR2 defect resulted in significantly observable neurobehavioral dysfunctions in mice starting from middle age, as well as multiple abnormalities in brain structure, function, and molecular metabolism.

Beta-amyloid activates NLRP3 inflammasome via TLR4 in mouse microglia.

Beta-amyloid(Aß)-induced inflammation plays a critical role in the pathogenesis of Alzheimer's disease (AD). Nod-like receptor nucleotide-binding domain leucine rich repeat containing protein 3 (NLRP3) inflammasome is involved in the Aß-induced inflammation. However, the mechanisms by which extracellular Aß activates cytoplasmic NLRP3 inflammasome are poorly understood. Toll-like receptor 4(TLR4) acts as a sensor of Aß and performs a key role in neuroinflammation. TLR4 is involved in activating the NLRP3 inflammasome in several diseases. In this study, the interaction between TLR4 and NLRP3 inflammasome in Aß1-42-induced neuroinflammation was investigated. BV-2 microglia and primary microglia were primed with lipopolysaccharide (LPS) and then pretreated with TLR4 inhibitor CLI-095, followed by stimulation with Aß1-42. The protein expression of NLRP3, the adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC), and caspase-1 p 10 was detected by western blotting and immunostaining. The mRNA expression of inflammatory factors was measured by real-time PCR. The protein level of pro IL-1ß and IL-1ß was examined by ELISA. Activated microglia were examined by immunofluorescence staining for ionized calcium-binding adapter molecule-1 (Iba-1). Conditioned medium of BV-2 cells was collected to challenge HT-22 neurons. Cell viability was assessed with MTT assay. Assessment of HT-22 cell apoptosis was performed by Annexin V/PI staining and western blotting to detect the protein level of cleaved caspase 3. The results showed that Aß1-42 activated and up-regulated the expression of NLRP3 inflammasome in BV-2 microglia, as indicated by increased activation of caspase-1 and secretion of IL-1ß. Pharmacological inhibition of TLR4 by CLI-095 abolished Aß1-42-induced NLRP3 inflammasome activation, which curbed the development of inflammation and exerted protective effect on HT-22 neurons. Furthermore, the inhibitory effects of CLI-095 on Aß1-42-induced inflammation were reversed by NLRP3 activator ATP. Overall, our findings suggested TLR4 mediated Aß1-42-induced NLRP3 inflammasome activation in mouse microglia. TLR4/NLRP3 pathway plays a critical role in Aß1-42-induced neuroinflammation.

Inhibition of NK1R attenuates LPS-induced microglial inflammation and consequent death of PC12 cells.

Microglia, the resident immune cells in the central nervous system, play a critical role under physiological conditions, but they may be activated and exaggerate the pathological development of Parkinson's disease (PD). Recent reports have suggested that neurokinin 1 receptor (NK1R) is involved in various inflammatory diseases, including PD. However, whether neurokinin 1 (NK1) is involved in the activation of microglial cells remains unclear. In the present study, we found that (1) NK1R is located in microglial cells and upregulated in lipopolysaccharide (LPS)-activated BV2 microglia. Application of CP-99994, a selective antagonist of NK1R, inhibited the production of inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1ß), IL-6, inducible macrophage-type nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in activated BV2 cells. (2) NK1R antagonist suppressed the morphological changes in LPS-stimulated BV2. (3) Microglial inactivation by NK1R antagonist resulted in decreased microglial migration. (4) NK1R antagonist reduced nuclear translocation of nuclear factor kappa-B (NF-κB) and attenuated phosphorylation of mitogen-activated protein kinases (MAPKs) in LPS-stimulated BV2. (5) The cell death of PC12 induced by microglia-mediated neuroinflammation was reversed in a Transwell co-culture system by NK1R antagonist. Collectively, these results showed that inhibition of NK1R attenuates LPS-induced microglial inflammatory response and dopaminergic neurotoxicity, which may be due to the decreased MAPK/NF-κB signal pathway. Thus, NK1R may be a therapeutic target in neuroinflammation, especially in PD.

An analysis of the clinical and imaging features of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).

Objective: To investigate the clinical features and imaging characteristics of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).Methods: Seventeen patients with MELAS diagnosed in the Affiliated Hospital of Xuzhou Medical University from July 2014 to August 2018 were enrolled in this study and their clinical manifestations, imaging and histopathological features were retrospectively analysed. We also discussed and summarised the related literature.Results: All of the 12 patients had seizures; stroke-like episodes in 12 cases; audio-visual impairment in 12 cases; headache in six cases; dysplasia in four cases; mental retardation in three cases; ataxia in two cases. On cranial magnetic resonance (MR) scans, the most common manifestations were in temporal-occipital-parietal lobe, cortical or subcortical areas as well as frontal lobe, thalamus, and basal ganglia showing long or equal T1 signals, long T2 signals, and hyperintense or iso-intense diffusion-weighted imaging (DWI) signals accompanied by ventricular enlargement and brain atrophy. MR spectroscopy showed that lactic acid peaks could be found in lesion sites, normal brain tissues, and cerebrospinal fluid. Muscle biopsy and genetic testing are the gold standard for diagnosing MELAS, muscle biopsy revealed COX-negative muscle fibres and SDH-stained red ragged fibres (RRF) under the sarcolemma. Mutations of mtDNA A3243G locus were common on gene testing. Improvement of mitochondrial function was observed after symptomatic and supportive treatment.Conclusion: MELAS should be considered for patients with epileptic seizures, headache, stroke-like episodes, extraocular palsy, cognitive decline and other clinical manifestations with the lesion located in the temporal-occipital-parietal lobe regardless of the distribution of blood vessels, and further examinations including muscle biopsy and gene testing should be performed to confirm the diagnosis.

Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice.

BACKGROUND: Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer's disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model. METHODS: Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl's and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention. RESULTS: Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction. CONCLUSION: Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

A Rare Case of Bilateral Vertebral Artery Dissection Associated with Essential Thrombocythemia.

A young patient presented to our hospital with ischemic stroke. She underwent a routine blood test, head computed tomography (CT), brain magnetic resonance imaging, a bone marrow biopsy, and CT angiography. Her diagnosis was a bilateral vertebral artery dissection associated with essential thrombocythemia (ET). She was treated with antiplatelet therapy and a stent implantation. The association of bilateral vertebral artery dissection with ET is rare. An early diagnosis and timely management is key to the best outcome.

Genomic deletion of TLR2 induces aggravated white matter damage and deteriorated neurobehavioral functions in mouse models of Alzheimer's disease.

Toll-like receptor-2 (TLR2), a member of the TLR family, plays an important role in the initiation and regulation of immune/inflammation response, which is a critical mechanism underlying Alzheimer's disease (AD). To clarify the role of TLR2 in the pathological process of AD, in the present study, TLR2 knockout plus APPswe/PSEN1dE9 transgenic mice (AD-TLR2KO) were generated. Neurobehavioral tests and brain MRI scan were conducted on mice at the age of 12 months. Additionally, neuron loss was evaluated using NeuN staining. Amyloid ß protein (Aß), glial fibrillary acidic protein (GFAP), endogenous ligands for TLR2, and the activation of downstream signaling of TLR2 in mouse brains were detected by immunohistochemistry and Western blots. The results demonstrated that TLR2 deficit induced learning disabilities, decreased spontaneous activity, increased anxiety and depression, and led to white matter damage (WMD), brain atrophy, loss of neurons, and glial activation. Moreover, TLR2 deficit aggravated impaired neurobehavioral functions and WMD in AD mice, but did not affect the Aß deposition in mouse brains. Our data indicate that the genomic deletion of TLR2 impairs neurobehavioral functions, induces WMD and brain atrophy, and increases the activation of astrocytes, which in turn aggravate the symptoms of AD through a non-Aß mechanism.

Superficial siderosis of central nervous system with unknown cause: report of 2 cases and review of the literature.

Objective: To report 2 cases of superficial siderosis of central nervous system (SS-CNS) and a review of the literature. Methods: We have analyzed the clinical data and relevant features of two patients with SS-CNS who were presented with ataxia and slurred speech. Both patients undertook blood tests, lumbar puncture, head CT (computer tomography) scans, and brain and spinal cord magnetic resonance (MR) scans. In addition, the first patient also undewent enhanced susceptibility-weighted angiography (ESWAN) and the second patient undertook susceptibility weighted imaging (SWI) scan. We searched PubMed with the keywords superficial siderosis and superficial siderosis of central nervous system, and selected publications that seemed appropriate. Results: A neurological examination revealed bilateral sensorineural hearing impairment in both the patients. Their past history was not significant to identify hemorrhage. Brain MR scans demonstrated typical hypointensity rimming at the brain surface on T2 weighted images. The patients were diagnosed with SS-CNS. Conclusion: SS-CNS should be highly suspected in patients with progressive sensorineural hearing loss, ataxia, and signs of pyramidal tracts, and MR scans of brain and whole spinal cord should be undertaken to confirm the diagnosis. Advanced MRI techniques such as SWI and ESWAN are helpful in making the diagnosis of SS-CNS. The cause of hemorrhage is not identified in most cases.