Multi-systemic melioidosis in a patient with type 2 diabetes in non-endemic areas: A case report and review of literature.

BACKGROUND: Melioidosis, an infectious disease caused by Burkholderia pseudomallei (B. pseudomallei), occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate. CASE SUMMARY: A 58-year-old woman presented with scattered erythema on the skin of her limbs, followed by fever and seizures. B. pseudomallei was isolated successively from the patient's urine, blood, and pus. Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region. Subsequently, abscess resection and drainage were performed. The patient showed no signs of relapse after 4 months of follow-up visits post-treatment. CONCLUSION: We present here a unique case of multi-systemic melioidosis that occurs in non-endemic regions in a patient who had no recent travel history. Hence, it is critical to enhance awareness of melioidosis in non-endemic regions.

Association of tirofiban with improvement of functional outcomes of direct thrombectomy for acute anterior circulation occlusion: a retrospective, nonrandomized, multicenter, real-world study.

OBJECTIVE: Although tirofiban and endovascular thrombectomy have been widely used in the treatment of acute ischemic stroke (AIS) patients, the effectiveness of their combined application remains a subject of debate. This study aimed to assess the efficacy and safety of tirofiban in direct thrombectomy for AIS with anterior circulation vessel occlusion. METHODS: A total of 204 patients undergoing direct thrombectomy between January 2020 and December 2021 for AIS with anterior circulation vessel occlusion from four hospitals were included in this study. Patients at high risk of reocclusion with severe atherosclerosis, those who achieved successful recanalization for ≥ 3 stent retriever passes, or those who underwent emergency stenting or balloon angioplasty for severe residual stenosis were treated with tirofiban. Following a low-dose intra-arterial bolus (0.25-1 mg) immediately after endovascular treatment, tirofiban was administered continuously through intravenous infusion (0.1 µg/kg/min) for 12-24 hours. The primary efficacy outcome was evaluated using the 90-day modified Rankin Scale score. The safety outcome was assessed using symptomatic intracerebral hemorrhage (sICH) and mortality rates. RESULTS: The tirofiban group and nontirofiban group each included 102 patients. The favorable outcome rate in the tirofiban group was significantly higher than that in the nontirofiban group (53.9% vs 35.3%, p = 0.007). However, the sICH and 90-day mortality rates were lower in the tirofiban group, despite a lack of statistical significance (sICH: 15.7% vs 16.7%, p = 0.849; 90-day mortality: 16.67% vs 24.51%, p = 0.166). Finally, it was found that older patients (> 72 years), male patients, patients with admission National Institutes of Health Stroke Scale scores > 14, patients with a time from onset to reperfusion > 327 minutes, and patients with a medical history of diabetes tend to benefit from tirofiban treatment. CONCLUSIONS: This study suggests that tirofiban combined with direct thrombectomy improves functional outcomes of AIS and reduces the 90-day mortality rate. Therefore, it could be considered as a suitable treatment option for AIS patients with anterior circulation vessel occlusion.

High-intensity interval training ameliorates chronic unpredictable mild stress-induced depressive behaviors via HDAC2-BDNF signaling in the ventral hippocampus.

Major depressive disorder (MDD) is a devastating psychiatric disease, and current therapies could not well meet the demand for MDD treatment. Exercise benefits mental illness, and notably, exercise has been recommended as an alternative option for MDD treatment in some countries. However, the paradigm and intensity of exercise for MDD treatment has yet to be determined. High-intensity interval training (HIIT) is a potent and time-efficient type of exercise training and has gained popularity in recent years. In this study, we exposed the mice to chronic unpredictable mild stress (CUMS) and found HIIT exerted substantial antidepressant effect. Moreover, HIIT further enhanced the antidepressant effect of fluoxetine, a classic antidepressant in the clinic, confirming the antidepressant role of HIIT. HIIT significantly reversed the CUMS-induced upregulations in HDAC2 mRNA and protein level in the ventral hippocampus. We also found HIIT rescued the CUMS-induced downregulation in the expression of brain-derived neurotrophic factor (BDNF) and HDAC2 overexpression counteracted the HIIT-induced increase in BDNF level. More importantly, both virus-mediated HDAC2 overexpression and microinfusion of TrkB-Fc, a BDNF scavenger, in the ventral hippocampus abolished the antidepressant effect of HIIT. Together, our results strongly demonstrate that HIIT attenuates depressive behaviors, probably via HDAC2-BDNF signaling pathway and reveal that HIIT may serve as an alternative option for MDD treatment.

Fasting blood glucose-to-glycated hemoglobin ratio for evaluating clinical outcomes in patients with ischemic stroke.

Background: Stress hyperglycemia frequently occurs in patients with acute ischemic stroke (AIS). The influence of stress hyperglycemia on the outcomes of patients with AIS remains ambiguous. Methods: Data from our institution on patients with AIS between June 2020 and June 2021 were retrospectively analyzed. The severity of the stroke was assessed using the National Institutes of Health Stroke Scale (NIHSS) at admission, and the primary endpoint was functional outcomes. Stress hyperglycemia was measured by the glucose-to-HbA1c ratio. In the multivariable analysis, two models that retained or excluded the NIHSS were adopted to explore the relationship between stress hyperglycemia and outcomes. The receiver operating characteristic curve (ROC) was calculated to determine an optimized cutoff value. Results: The optimal cutoff value was 1.135. When all patients were included, model 1 did not find an association between the glucose-to-HbA1c ratio and functional outcomes. In model 2, the glucose-to-HbA1c ratio×10 (Glucose-to-HbA1c ratio ×10) was the independent predictor of functional outcomes (OR 1.19, 95% CI 1.07-1.33, p < 0.01). Separately, in patients without diabetes, the glucose-to-HbA1c ratio×10 was the independent predictor of functional outcomes in both model 1 (OR 1.37, 95% CI 1.08-1.73, p = 0.01) and model 2 (OR 1.48, 95% CI 1.22-1.79, p < 0.01), but not in patients with diabetes. In addition, the glucose-to-HbA1c ratio×10 was the independent predictor of stroke severity (OR 1.16, 95% CI 1.05-1.28, p < 0.01). Conclusion: The glucose-to-HbA1c ratio was associated with more severe AIS. Specifically, the glucose-to-HbA1c ratio was associated with the functional outcomes in patients without diabetes but not in patients with diabetes.

Ketone bodies promote stroke recovery via GAT-1-dependent cortical network remodeling.

Stroke is a leading cause of adult disability worldwide, and better drugs are needed to promote functional recovery after stroke. Growing evidence suggests the critical role of network excitability during the repair phase for stroke recovery. Here, we show that ß-hydroxybutyrate (ß-HB), an essential ketone body (KB) component, is positively correlated with improved outcomes in patients with stroke and promotes functional recovery in rodents with stroke during the repair phase. These beneficial effects of ß-HB depend on HDAC2/HDAC3-GABA transporter 1 (GAT-1) signaling-mediated enhancement of excitability and phasic GABA inhibition in the peri-infarct cortex and structural and functional plasticity in the ipsilateral cortex, the contralateral cortex, and the corticospinal tract. Together with available clinical approaches to elevate KB levels, our results offer a clinically translatable means to promote stroke recovery. Furthermore, GAT-1 can serve as a pharmacological target for developing drugs to promote functional recovery after stroke.

ROS-Scavenging Hydrogels Synergize with Neural Stem Cells to Enhance Spinal Cord Injury Repair via Regulating Microenvironment and Facilitating Nerve Regeneration.

Although stem cell-based therapy is recognized as a promising therapeutic strategy for spinal cord injury (SCI), its efficacy is greatly limited by local reactive oxygen species (ROS)-abundant and hyper-inflammatory microenvironments. It is still a challenge to develop bioactive scaffolds with outstanding antioxidant capacity for neural stem cells (NSCs) transplantation. In this study, albumin biomimetic cerium oxide nanoparticles (CeO2 @BSA nanoparticles, CeNPs) are prepared in a simple and efficient manner and dispersed in gelatin methacryloyl to obtain the ROS-scavenging hydrogel (CeNP-Gel). CeNP-Gel synergistically promotes neurogenesis via alleviating oxidative stress microenvironments and improving the viability of encapsulated NSCs. More interestingly, in the presence of CeNP-Gel, microglial polarization to anti-inflammatory M2 subtype are obviously facilitated, which is further verified to be associated with phosphoinositide 3-kinase/protein kinase B pathway activation. Additionally, the injectable ROS-scavenging hydrogel is confirmed to induce the integration and neural differentiation of transplanted NSCs. Compared with the blank-gel group, the survival rate of NSCs in CeNP-Gel group is about 3.5 times higher, and the neural differentiation efficiency is about 2.1 times higher. Therefore, the NSCs-laden ROS-scavenging hydrogel represents a comprehensive strategy with great application prospect for the treatment of SCI through comprehensively modulating the adverse microenvironment.

Identification of Pyroptosis-Relevant Signature in Tumor Immune Microenvironment and Prognosis in Skin Cutaneous Melanoma Using Network Analysis.

Background: Pyroptosis is closely related to the programmed death of cancer cells as well as the tumor immune microenvironment (TIME) via the host-tumor crosstalk. However, the role of pyroptosis-related genes as prognosis and TIME-related biomarkers in skin cutaneous melanoma (SKCM) patients remains unknown. Methods: We evaluated the expression profiles, copy number variations, and somatic mutations (CNVs) of 27 genes obtained from MSigDB database regulating pyroptosis among TCGA-SKCM patients. Thereafter, we conducted single-sample gene set enrichment analysis (ssGSEA) for evaluating pyroptosis-associated expression patterns among cases and for exploring the associations with clinicopathological factors and prognostic outcome. In addition, a prognostic pyroptosis-related signature (PPRS) model was constructed by performing Cox regression, weighted gene coexpression network analysis (WGCNA), and least absolute shrinkage and selection operator (LASSO) analysis to score SKCM patients. On the other hand, we plotted the ROC and survival curves for model evaluation and verified the robustness of the model through external test sets (GSE22153, GSE54467, and GSE65904). Meanwhile, we examined the relations of clinical characteristics, oncogene mutations, biological processes (BPs), tumor stemness, immune infiltration degrees, immune checkpoints (ICs), and treatment response with PPRS via multiple methods, including immunophenoscore (IPS) analysis, gene set variation analysis (GSVA), ESTIMATE, and CIBERSORT. Finally, we constructed a nomogram incorporating PPRS and clinical characteristics to improve risk evaluation of SKCM. Results: Many pyroptosis-regulated genes showed abnormal expression within SKCM. TP53, TP63, IL1B, IL18, IRF2, CASP5, CHMP4C, CHMP7, CASP1, and GSDME were detected with somatic mutations, among which, a majority displayed CNVs at high frequencies. Pyroptosis-associated profiles established based on pyroptosis-regulated genes showed markedly negative relation to low stage and superior prognostic outcome. Blue module was found to be highly positively correlated with pyroptosis. Later, this study established PPRS based on the expression of 8 PAGs (namely, GBP2, HPDL, FCGR2A, IFITM1, HAPLN3, CCL8, TRIM34, and GRIPAP1), which was highly associated with OS, oncogene mutations, tumor stemness, immune infiltration degrees, IC levels, treatment responses, and multiple biological processes (including cell cycle and immunoinflammatory response) in training and test set samples. Conclusions: Based on our observations, analyzing modification patterns associated with pyroptosis among diverse cancer samples via PPRS is important, which can provide more insights into TIME infiltration features and facilitate immunotherapeutic development as well as prognosis prediction.

A Presurgical Unfavorable Prediction Scale of Endovascular Treatment for Acute Ischemic Stroke.

Objective: To develop a prognostic prediction model of endovascular treatment (EVT) for acute ischemic stroke (AIS) induced by large-vessel occlusion (LVO), this study applied machine learning classification model light gradient boosting machine (LightGBM) to construct a unique prediction model. Methods: A total of 973 patients were enrolled, primary outcome was assessed with modified Rankin scale (mRS) at 90 days, and favorable outcome was defined using mRS 0-2 scores. Besides, LightGBM algorithm and logistic regression (LR) were used to construct a prediction model. Then, a prediction scale was further established and verified by both internal data and other external data. Results: A total of 20 presurgical variables were analyzed using LR and LightGBM. The results of LightGBM algorithm indicated that the accuracy and precision of the prediction model were 73.77 and 73.16%, respectively. The area under the curve (AUC) was 0.824. Furthermore, the top 5 variables suggesting unfavorable outcomes were namely admitting blood glucose levels, age, onset to EVT time, onset to hospital time, and National Institutes of Health Stroke Scale (NIHSS) scores (importance = 130.9, 102.6, 96.5, 89.5 and 84.4, respectively). According to AUC, we established the key cutoff points and constructed prediction scale based on their respective weightings. Then, the established prediction scale was verified in raw and external data and the sensitivity was 80.4 and 83.5%, respectively. Finally, scores >3 demonstrated better accuracy in predicting unfavorable outcomes. Conclusion: Presurgical prediction scale is feasible and accurate in identifying unfavorable outcomes of AIS after EVT.

Atorvastatin ameliorates depressive behaviors via regulation of α7nAChR expression by PI3K/Akt-BDNF pathway in mice.

Some of the statins have been shown to have antidepressant effects, but whether atorvastatin (AV) has antidepressant effects is unknown. This study was to investigate the effect of AV treatment on depressive behaviors. Herein, we show that AV treatment had antidepressant-like effect in physiological conditions and antidepressant effect in depressive state which depended on α7 nicotinic acetylcholine receptor (α7nAChR) expression in the ventral hippocampus (vHPC), but not α4ß2 nicotinic acetylcholine receptor (α4ß2nAchR) expression in vHPC, nor the α7nAChR and α4ß2nAchR expression in dorsal hippocampus (dHPC). By using MLA, a selective α7nAChR antagonist, we investigated the role of α7nAChR in AV treatment. Behavior tests demonstrated that MLA abolished the antidepressant effect of AV. Besides, our data showed that AV treatment increased Akt phosphorylation, brain-derived neurotrophic factor (BDNF), synaptic related protein synapsin and spinophilin expression. The phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 reversed AV-induced increase of BDNF expression, newborn neurons and antidepressant behavior effects. Our study suggests that AV plays an antidepressant role by regulating synaptic plasticity of vHPC through PI3K/Akt-BDNF signaling pathway, which may be a good choice for depression treatment.

Mesencephalic astrocyte-derived neurotrophic factor restores blood-brain barrier integrity of aged mice after ischaemic stroke/reperfusion through anti-inflammation via TLR4/MyD88/NF-κB pathway.

Ischaemic stroke remains a leading cause of disability and mortality worldwide and ageing-associated inflammation for the aged patients specifically leads to worse post-stroke blood-brain barrier (BBB) disruption than young subjects. Accordingly, suppression of excessive inflammation can alleviate BBB injury, which provides potential therapeutic treatment for ischaemic stroke of the aged. Prior studies revealed that mesencephalic astrocyte-derived neurotrophic factor (MANF) regulated inflammatory response and alleviated liver injury in ageing. However, it is unclear whether MANF confer similar benefit to BBB of aged mice suffered from ischaemic stroke. Transient cerebral ischaemia induced by middle cerebral artery occlusion (MCAO) was conducted in aged mice (18-20 months old). MANF was injected into the right lateral ventricle 2 h after MCAO. BBB integrity, tight junctional proteins, ultrastructure of microvessels, infarct volume, neurological scores, brain water content, pro-inflammatory cytokines and neutrophil infiltration rate were determined 72 h after MCAO. H2O2-induced senescent bEnd.3 cells were applied in the in vitro study to investigate the possible mechanism. First, we confirmed that ischaemic stroke/reperfusion in senescent condition promoted the over-expression of MANF on brain endothelial cells. Then, MANF supplement could suppress the pro-inflammatory factor production, restore BBB integrity and then alleviate infarct volume, neurological scores, brain water content and neutrophil infiltration rate. In addition, MANF maintained BBB integrity after ischaemic stroke of aged condition dependent on TLR4/MyD88/NF-κB pathway via intervention of pro-inflammatory factors production. In summary, the recognition of MANF in the process of BBB breakdown at aged condition may offer novel therapeutic approaches for ischaemic stroke.

Environmental enrichment implies GAT-1 as a potential therapeutic target for stroke recovery.

Rationale: Stroke is a leading cause of adult disability worldwide, but no drug provides functional recovery during the repair phase. Accumulating evidence demonstrates that environmental enrichment (EE) promotes stroke recovery by enhancing network excitability. However, the complexities of utilizing EE in a clinical setting limit its translation. Methods: We used multifaceted approaches combining electrophysiology, chemogenetics, optogenetics, and floxed mice in a mouse photothrombotic stroke model to reveal the key target of EE-mediated stroke recovery. Results: EE reduced tonic gamma-aminobutyric acid (GABA) inhibition and facilitated phasic GABA inhibition in the peri-infarct cortex, thereby promoting network excitability and stroke recovery. These beneficial effects depended on GAT-1, a GABA transporter regulating both tonic and phasic GABA signaling, as EE positively regulated GAT-1 expression, trafficking, and function. Furthermore, GAT-1 was necessary for EE-induced network plasticity, including structural neuroplasticity, input synaptic strengthening in the peri-infarct cortex, output synaptic strengthening in the corticospinal tract, and sprouting of uninjured corticospinal axons across the midline into the territory of denervated spinal cord, and functional recovery from stroke. Moreover, restoration of GAT-1 function in the peri-infarct cortex by its overexpression showed similar beneficial effects on stroke recovery as EE exposure. Conclusion: GAT-1 is a key molecular substrate of the effects of EE on network excitability and consequent stroke recovery and can serve as a novel therapeutic target for stroke treatment during the repair phase.

HDAC2 (Histone deacetylase 2): A critical factor in environmental enrichment-mediated stroke recovery.

Environmental enrichment (EE) is a generally accepted strategy to promote stroke recovery and its beneficial effect is positively correlated with neuroplasticity. However, the mechanisms underlying it remain elusive. Histone deacetylase 2 (HDAC2), a negative regulator of neuroplasticity, is up-regulated after stroke. Thus, we hypothesized that HDAC2 may participate in EE-mediated stroke recovery. In this study, focal stroke was induced by photothrombosis in male mice exposing to EE or standard housing (SH) conditions. Recombinant virus vectors, including Ad-HDAC2-Flag, AAV-CAG-EGFP-Cre, LV-shHDAC2, or their controls were microinjected into the motor cortex at 3 days before stroke. Grid-walking and cylinder tasks were conducted to assess motor function. Western blot and immunostaining were used to uncover the mechanisms underlying EE-mediated stroke recovery. We found that EE exposure reversed stroke-induced HDAC2 up-regulation, implicating HDAC2 in EE-mediated functional recovery. Importantly, EE-dependent stroke recovery was counteracted by over-expressing HDAC2, and HDAC2 knockdown promoted functional recovery from stroke to the similar extent as EE exposure. Moreover, the knockdown of HDAC2 epigenetically enhanced expressions of neurotrophins and neuroplasticity-related proteins, with similar effects as EE, and consequently, whole brain and corticospinal tract (CST) rewiring. Together, our findings indicate that HDAC2 is critical for EE-dependent functional restoration. Precisely targeting HDAC2 may mimic EE and serve as a novel therapeutic strategy for stroke recovery.

Dissociating nNOS (Neuronal NO Synthase)-CAPON (Carboxy-Terminal Postsynaptic Density-95/Discs Large/Zona Occludens-1 Ligand of nNOS) Interaction Promotes Functional Recovery After Stroke via Enhanced Structural Neuroplasticity.

Background and Purpose- Stroke is a major public health concern worldwide. Although clinical treatments have improved in the acute period after stroke, long-term therapeutics remain limited to physical rehabilitation in the delayed phase. This study is aimed to determine whether nNOS (neuronal NO synthase)-CAPON (carboxy-terminal postsynaptic density-95/discs large/zona occludens-1 ligand of nNOS) interaction may serve as a new therapeutic target in the delayed phase for stroke recovery. Methods- Photothrombotic stroke and transient middle cerebral artery occlusion were induced in mice. Adeno-associated virus (AAV)-cytomegalovirus (CMV)-CAPON-125C-GFP (green fluorescent protein)-3Flag and the other 2 drugs (Tat-CAPON-12C and ZLc-002) were microinjected into the peri-infarct cortex immediately and 4 to 10 days after photothrombotic stroke, respectively. ZLc-002 was also systemically injected 4 to 10 days after transient middle cerebral artery occlusion. Grid-walking task and cylinder task were conducted to assess motor function. Western blotting, immunohistochemistry, Golgi staining, and electrophysiology recordings were performed to uncover the mechanisms. Results- Stroke increased nNOS-CAPON association in the peri-infarct cortex in the delayed period. Inhibiting the ischemia-induced nNOS-CAPON association substantially decreased the number of foot faults in the grid-walking task and forelimb asymmetry in the cylinder task, suggesting the promotion of functional recovery from stroke. Moreover, dissociating nNOS-CAPON significantly facilitated dendritic remodeling and synaptic transmission, indicated by increased dendritic spine density, dendritic branching, and length and miniature excitatory postsynaptic current frequency but did not affect stroke-elicited neuronal loss, infarct size, or cerebral edema, suggesting that nNOS-CAPON interaction may function via regulating structural neuroplasticity, rather than neuroprotection. Furthermore, ZLc-002 reversed the transient middle cerebral artery occlusion-induced impairment of motor function. Conclusions- Our results reveal that nNOS-CAPON coupling can serve as a novel pharmacological target for functional restoration after stroke.

2-Methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine, an edaravone analog, exerts neuroprotective effects against acute ischemic injury via inhibiting oxidative stress.

Oxidative stress plays an indispensable role in the pathogenesis of cerebral ischemia. Inhibiting oxidative stress has been considered as an effective approach for stroke treatment. Edaravone, a free radical scavenger, has been shown to prevent cerebral ischemic injury. However, the clinical efficacy of edaravone is limited because it has a low scavenging activity for superoxide anions (O2·-). Here, we report that 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine, a novel small-molecule compound structurally related to edaravone, showed a stronger inhibitory effect on oxidative stress in vitro. In vivo, 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine reversed transient middle cerebral artery occlusion-induced dysfunctions of superoxide dismutases and malondialdehyde, two proteins crucial for oxidative stress, suggesting a strengthened antioxidant system. Moreover, 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased blood brain barrier permeability. Then, we found that 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine had a stronger neuroprotective effect than edaravone. More importantly, 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine decreased not only infarct size and neurological deficits in the acute phase but also modified neurological severity score and escape latency in Morris water maze task in the delayed period, indicating enhanced neuroprotection, sensorimotor function and spatial memory. Together, these findings suggest that 2-methyl-5H-benzo[d]pyrazolo[5,1-b][1,3]oxazin-5-imine could be a preferable option for stroke treatment.

Hippocampal nuclear factor kappa B accounts for stress-induced anxiety behaviors via enhancing neuronal nitric oxide synthase (nNOS)-carboxy-terminal PDZ ligand of nNOS-Dexras1 coupling.

Anxiety disorders are associated with a high social burden worldwide. Recently, increasing evidence suggests that nuclear factor kappa B (NF-κB) has significant implications for psychiatric diseases, including anxiety and depressive disorders. However, the molecular mechanisms underlying the role of NF-κB in stress-induced anxiety behaviors are poorly understood. In this study, we show that chronic mild stress (CMS) and glucocorticoids dramatically increased the expression of NF-κB subunits p50 and p65, phosphorylation and acetylation of p65, and the level of nuclear p65 in vivo and in vitro, implicating activation of NF-κB signaling in chronic stress-induced pathological processes. Using the novelty-suppressed feeding (NSF) and elevated-plus maze (EPM) tests, we found that treatment with pyrrolidine dithiocarbamate (PDTC; intra-hippocampal infusion), an inhibitor of NF-κB, rescued the CMS- or glucocorticoid-induced anxiogenic behaviors in mice. Microinjection of PDTC into the hippocampus reversed CMS-induced up-regulation of neuronal nitric oxide synthase (nNOS), carboxy-terminal PDZ ligand of nNOS (CAPON), and dexamethasone-induced ras protein 1 (Dexras1) and dendritic spine loss of dentate gyrus (DG) granule cells. Moreover, over-expression of CAPON by infusing LV-CAPON-L-GFP into the hippocampus induced nNOS-Dexras1 interaction and anxiety-like behaviors, and inhibition of NF-κB by PDTC reduced the LV-CAPON-L-GFP-induced increases in nNOS-Dexras1 complex and anxiogenic-like effects in mice. These findings indicate that hippocampal NF-κB mediates anxiogenic behaviors, probably via regulating the association of nNOS-CAPON-Dexras1, and uncover a novel approach to the treatment of anxiety disorders.

nNOS-CAPON interaction mediates amyloid-ß-induced neurotoxicity, especially in the early stages.

In neurons, increased protein-protein interactions between neuronal nitric oxide synthase (nNOS) and its carboxy-terminal PDZ ligand (CAPON) contribute to excitotoxicity and abnormal dendritic spine development, both of which are involved in the development of Alzheimer's disease. In models of Alzheimer's disease, increased nNOS-CAPON interaction was detected after treatment with amyloid-ß in vitro, and a similar change was found in the hippocampus of APP/PS1 mice (a transgenic mouse model of Alzheimer's disease), compared with age-matched background mice in vivo. After blocking the nNOS-CAPON interaction, memory was rescued in 4-month-old APP/PS1 mice, and dendritic impairments were ameliorated both in vivo and in vitro. Furthermore, we demonstrated that S-nitrosylation of Dexras1 and inhibition of the ERK-CREB-BDNF pathway might be downstream of the nNOS-CAPON interaction.

Dissociation of nNOS from PSD-95 promotes functional recovery after cerebral ischaemia in mice through reducing excessive tonic GABA release from reactive astrocytes.

Mechanisms underlying functional recovery after stroke are little known, and effective drug intervention during the delayed stage is desirable. One potential drug target, the protein-protein interaction between neuronal nitric oxide synthase (nNOS) and postsynaptic density protein 95 (PSD-95), is critical to acute ischaemic damage and neurogenesis. We show that nNOS-PSD-95 dissociation induced by microinjection of a recombinant fusion protein, Tat-nNOS-N1-133 , or systemic administration of a small-molecule, ZL006, from day 4 to day 10 after photothrombotic ischaemia in mice reduced excessive tonic inhibition in the peri-infarct cortex and ameliorated motor functional outcome. We also demonstrated improved neuroplasticity including increased dendrite spine density and synaptogenesis after reducing excessive tonic inhibition by nNOS-PSD-95 dissociation. Levels of gamma-aminobutyric acid (GABA) and GABA transporter-3/4 (GAT-3/4) are increased in the reactive astrocytes in the peri-infarct cortex. The GAT-3/4-selective antagonist SNAP-5114 reduced tonic inhibition and promoted function recovery, suggesting that increased tonic inhibition in the peri-infarct cortex was due to GABA release from reversed GAT-3/4 in reactive astrocytes. Treatments with Tat-nNOS-N1-133 or ZL006 after ischaemia inhibited astrocyte activation and GABA production, prevented the reversal of GAT-3/4, and consequently decreased excessive tonic inhibition and ameliorated functional outcome. The underlying molecular mechanisms were associated with epigenetic inhibition of glutamic acid decarboxylase 67 and monoamine oxidase B expression through reduced NO production. The nNOS-PSD-95 interaction is thus a potential target for functional restoration after stroke and ZL006, a small molecule inhibitor of this interaction, is a promising pharmacological lead compound. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

(+)-Borneol suppresses conditioned fear recall and anxiety-like behaviors in mice.

Fear- and anxiety-related psychiatric disorders have been one of the major chronic diseases afflicting patients for decades, and new compounds for treating such disorders remain to be developed. (+)-Borneol, a bicyclic monoterpene found in several species of Artemisia and Dipterocarpaceae, is widely used for anxiety, pain and anesthesia in Chinese medicine. Meanwhile, it can potentiate GABA (γ-aminobutyric acid) activity directly in recombinant GABAA receptors. The present study was to investigate the effects of (+)-Borneol on both contextual and cued fear recall. Interestingly, microinjection of (+)-Borneol into the dorsal hippocampus inhibited 24 h and 7 d contextual fear, whereas its infusion into ventral hippocampus only reduced 24 h cued fear responses. Moreover, microinjection of (+)-Borneol into dorsal but not ventral hippocampus suppressed anxiety-like behaviors in the open field test, light/dark exploration and the elevated plus maze test. As selective GABAA receptor antagonist bicuculline reversed the effect of (+)-Borneol on contextual fear paradigm and the drug potentiated GABA-evoked currents in acute hippocampus slices, modulation of the GABAergic neurotransmission may explain the effects of (+)-Borneol. Our findings suggest that (+)-Borneol can serve as a new therapeutic in fear- and anxiety-related disorders.

Inhibiting Histone Deacetylase 2 (HDAC2) Promotes Functional Recovery From Stroke.

BACKGROUND: Stroke is a leading cause of long-term disability worldwide. However, current therapies that promote functional recovery from stroke are limited to physical rehabilitation. No pharmacological therapy is available. Thus, understanding the role of histone deacetylase 2 (HDAC2) in the pathophysiological process of stroke-induced functional loss may provide a novel strategy for stroke recovery. METHODS AND RESULTS: Focal stroke was induced by photothrombosis. LV-HDAC2-shRNA-GFP, LV-GFP, Ad-HDAC2-Flag, or Ad-inactive-HDAC2-Flag was microinjected into the peri-infarct area immediately after stroke. HDAC inhibitors were microinjected into the peri-infarct area 4 to 10 days after stroke. Grid-walking task and cylinder task were conducted to assess motor function. Golgi-Cox staining, chromatin immunoprecipitation, and electrophysiology were used to reveal the mechanisms underlying stroke recovery. Knockdown or knockout of HDAC2 promoted stroke recovery, whereas overexpression of HDAC2 worsened stroke-induced functional impairment. More importantly, trichostatin A, a pan-HDAC inhibitor, promoted functional recovery from stroke in WT mice when used in the delayed phase, but it was ineffective in Hdac2 conditional knockout (Hdac2 CKO) mice. Treatment with suberoylanilide hydroxamic acid, a selective HDAC1 and HDAC2 inhibitor, in the delayed phase of stroke produced sustained functional recovery in mice via epigenetically enhancing neuroplasticity of surviving neurons in the peri-infarct zone. CONCLUSIONS: Our novel findings provide evidence that HDAC2 is a crucial target for functional recovery from stroke. As there are clinically available HDAC inhibitors, our findings could be directly translated into clinical research of stroke.

MGE-derived nNOS+ interneurons promote fear acquisition in nNOS-/- mice.

Neuronal nitric oxide synthase (nNOS) 1, mainly responsible for NO release in central nervous system (CNS) 2, plays a significant role in multiple physiological functions. However, the function of nNOS+ interneurons in fear learning has not been much explored. Here we focused on the medial ganglionic eminences (MGE) 3-derived nNOS+ interneurons in fear learning. To determine the origin of nNOS+ interneurons, we cultured neurons in vitro from MGE, cortex, lateral ganglionic eminence (LGE) 4, caudal ganglionic eminences (CGE) 5 and preoptic area (POA) 6. The results showed that MGE contained the most abundant precursors of nNOS+ interneurons. Moreover, donor cells from E12.5 embryos demonstrated the highest positive rate of nNOS+ interneurons compared with other embryonic periods (E11.5, E12, E13, E13.5 and E14). Additionally, these cells from E12.5 embryos showed long axonal and abundant dendritic arbors after 10 days culture, indicating the capability to disperse and integrate in host neural circuits after transplantation. To investigate the role of MGE-derived nNOS+ interneurons in fear learning, donor MGE cells were transplanted into dentate gyrus (DG) 7 of nNOS knock-out (nNOS-/-) or wild-type mice. Results showed that the transplantation of MGE cells promoted the acquisition of nNOS-/- but not the wild-type mice, suggesting the importance of nNOS+ neurons in fear acquisition. Moreover, we transplanted MGE cells from nNOS-/- mice or wild-type mice into DG of the nNOS-/- mice and found that only MGE cells from wild-type mice but not the nNOS-/- mice rescued the deficit in acquisition of the nNOS-/- mice, further confirming the positive role of nNOS+ neurons in fear learning.