Small-molecule inhibitors that disrupt the MTDH-SND1 complex suppress breast cancer progression and metastasis.

Metastatic breast cancer is a leading health burden worldwide. Previous studies have shown that metadherin (MTDH) promotes breast cancer initiation, metastasis and therapy resistance; however, the therapeutic potential of targeting MTDH remains largely unexplored. Here, we used genetically modified mice and demonstrate that genetic ablation of Mtdh inhibits breast cancer development through disrupting the interaction with staphylococcal nuclease domain-containing 1 (SND1), which is required to sustain breast cancer progression in established tumors. We performed a small-molecule compound screening to identify a class of specific inhibitors that disrupts the protein-protein interaction (PPI) between MTDH and SND1 and show that our lead candidate compounds C26-A2 and C26-A6 suppressed tumor growth and metastasis and enhanced chemotherapy sensitivity in preclinical models of triple-negative breast cancer (TNBC). Our results demonstrate a significant therapeutic potential in targeting the MTDH-SND1 complex and identify a new class of therapeutic agents for metastatic breast cancer.

Pneumonia due to Schizophyllum commune in a Patient with Acute Myeloid Leukemia: Case Report and Literature Review.

Schizophyllum commune is a mold in phylum Basidiomycota and is an uncommon human pathogen. Sinusitis and allergic bronchopulmonary mycosis are the two major diseases caused by S. commune. Although there have been several reports of invasive fungal diseases, most of them were invasive sinusitis. We present a case of invasive fungal pneumonia due to S. commune, developed in a patient with acute myeloid leukemia presenting neutropenic fever. The diagnosis was made by characteristic macroscopic and microscopic findings of fungal isolate and was confirmed via sequencing of internal transcribed spacer region. The patient was improved after 8 weeks of antifungal therapy based on the susceptibility result. We propose that S. commune should be considered as an emerging pathogen of invasive fungal pneumonia when a patient is under immunocompromised state. We also reviewed global literatures focused on the invasive fungal diseases caused by S. commune.

SHMT2 inhibition disrupts the TCF3 transcriptional survival program in Burkitt lymphoma.

Burkitt lymphoma (BL) is an aggressive lymphoma type that is currently treated by intensive chemoimmunotherapy. Despite the favorable clinical outcome for most patients with BL, chemotherapy-related toxicity and disease relapse remain major clinical challenges, emphasizing the need for innovative therapies. Using genome-scale CRISPR-Cas9 screens, we identified B-cell receptor (BCR) signaling, specific transcriptional regulators, and one-carbon metabolism as vulnerabilities in BL. We focused on serine hydroxymethyltransferase 2 (SHMT2), a key enzyme in one-carbon metabolism. Inhibition of SHMT2 by either knockdown or pharmacological compounds induced anti-BL effects in vitro and in vivo. Mechanistically, SHMT2 inhibition led to a significant reduction of intracellular glycine and formate levels, which inhibited the mTOR pathway and thereby triggered autophagic degradation of the oncogenic transcription factor TCF3. Consequently, this led to a collapse of tonic BCR signaling, which is controlled by TCF3 and is essential for BL cell survival. In terms of clinical translation, we also identified drugs such as methotrexate that synergized with SHMT inhibitors. Overall, our study has uncovered the dependency landscape in BL, identified and validated SHMT2 as a drug target, and revealed a mechanistic link between SHMT2 and the transcriptional master regulator TCF3, opening up new perspectives for innovative therapies.

Contemporary use of guideline-based higher potency P2Y12 receptor inhibitor therapy in patients with moderate-to-high risk non-ST-segment elevation myocardial infarction: Results from the Canadian ACS reflective II cross-sectional study.

BACKGROUND: After myocardial infarction, guidelines recommend higher-potency P2Y12 receptor inhibitors, namely ticagrelor and prasugrel, over clopidogrel. HYPOTHESIS: We aimed to determine the contemporary use of higher-potency antiplatelet therapy in Canadian patients with non-ST-elevation myocardial infarction (NSTEMI). METHODS: A total of 684 moderate-to-high risk NSTEMI patients were enrolled in the prospective Canadian ACS Reflective II registry at 12 Canadian hospitals and three clinics in five provinces between July 2016 and May 2018. Multivariable logistic regression modeling was performed to assess factors independently associated with higher-potency P2Y12 receptor inhibitor use at discharge. RESULTS: At hospital discharge, 78.3% of patients were treated with a P2Y12 receptor inhibitor. Among patients discharged on a P2Y12 receptor inhibitor, use of higher-potency P2Y12 receptor inhibitor was 61.4%. After adjustment, treatment in-hospital with PCI (OR 4.48, 95%CI 3.34-6.03, p < .0001) was most strongly associated with higher use of higher-potency P2Y12 receptor inhibitor, while oral anticoagulant use at discharge (OR 0.03, 95%CI 0.01-0.12, p < .0001), and atrial fibrillation (OR 0.40, 95%CI 0.17-0.98, p = .046) were most strongly associated with lower use of higher-potency P2Y12 receptor inhibitor. Use of higher-potency P2Y12 receptor inhibitor varied across provinces (range, 21.6%-78.9%). DISCUSSION: In contemporary Canadian practice, approximately 60% of moderate-to-high risk NSTEMI patients discharged on a P2Y12 receptor inhibitor are treated with a higher-potency P2Y12 receptor inhibitor. In addition to factors that increase risk of bleeding, interprovincial differences in practice patterns were associated with use of higher-potency P2Y12 receptor inhibitor at discharge. Opportunities remain for further optimization of evidence-based, guideline-recommended antiplatelet therapy use.

Initial Findings From the North American COVID-19 Myocardial Infarction Registry.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has impacted many aspects of ST-segment elevation myocardial infarction (STEMI) care, including timely access to primary percutaneous coronary intervention (PPCI). OBJECTIVES: The goal of the NACMI (North American COVID-19 and STEMI) registry is to describe demographic characteristics, management strategies, and outcomes of COVID-19 patients with STEMI. METHODS: A prospective, ongoing observational registry was created under the guidance of 3 cardiology societies. STEMI patients with confirmed COVID+ (group 1) or suspected (person under investigation [PUI]) (group 2) COVID-19 infection were included. A group of age- and sex-matched STEMI patients (matched to COVID+ patients in a 2:1 ratio) treated in the pre-COVID era (2015 to 2019) serves as the control group for comparison of treatment strategies and outcomes (group 3). The primary outcome was a composite of in-hospital death, stroke, recurrent myocardial infarction, or repeat unplanned revascularization. RESULTS: As of December 6, 2020, 1,185 patients were included in the NACMI registry (230 COVID+ patients, 495 PUIs, and 460 control patients). COVID+ patients were more likely to have minority ethnicity (Hispanic 23%, Black 24%) and had a higher prevalence of diabetes mellitus (46%) (all p < 0.001 relative to PUIs). COVID+ patients were more likely to present with cardiogenic shock (18%) but were less likely to receive invasive angiography (78%) (all p < 0.001 relative to control patients). Among COVID+ patients who received angiography, 71% received PPCI and 20% received medical therapy (both p < 0.001 relative to control patients). The primary outcome occurred in 36% of COVID+ patients, 13% of PUIs, and 5% of control patients (p < 0.001 relative to control patients). CONCLUSIONS: COVID+ patients with STEMI represent a high-risk group of patients with unique demographic and clinical characteristics. PPCI is feasible and remains the predominant reperfusion strategy, supporting current recommendations.

Synergistic efficacy and diminished adverse effect profile of composite treatment of several ADHD medications.

Although attention-deficit/hyperactivity disorder (ADHD) is widely studied, problems regarding the adverse effect risks and non-responder problems still need to be addressed. Combination pharmacotherapy using standard dose regimens of existing medication is currently being practiced mainly to augment the therapeutic efficacy of each drug. The idea of combining different pharmacotherapies with different molecular targets to alleviate the symptoms of ADHD and its comorbidities requires scientific evidence, necessitating the investigation of their therapeutic efficacy and the mechanisms underlying the professed synergistic effects. Here, we injected male ICR mice with MK-801 to induce ADHD behavioral condition. We then modeled a "combined drug" using sub-optimal doses of methylphenidate, atomoxetine, and fluoxetine and investigated the combined treatment effects in MK-801-treated mice. No sub-optimal dose monotherapy alleviated ADHD behavioral condition in MK-801-treated mice. However, treatment with the combined drug attenuated the impaired behavior of MK-801-treated animals. Growth impediment, sleep disturbances, or risk of substance abuse were not observed in mice treated subchronically with the combined drugs. Finally, we observed that the combined ADHD drug rescued alterations in p-AKT and p-ERK1/2 levels in the prefrontal cortex and hippocampus, respectively, of MK-801-treated mice. Our results provide experimental evidence of a possible new pharmacotherapy option in ameliorating the ADHD behavioral condition without the expected adverse effects. The detailed mechanism of action underlying the synergistic therapeutic efficacy and reduced adverse reaction by combinatorial drug treatment should be investigated further in future studies.

SHMT inhibition is effective and synergizes with methotrexate in T-cell acute lymphoblastic leukemia.

Folate metabolism enables cell growth by providing one-carbon (1C) units for nucleotide biosynthesis. The 1C units are carried by tetrahydrofolate, whose production by the enzyme dihydrofolate reductase is targeted by the important anticancer drug methotrexate. 1C units come largely from serine catabolism by the enzyme serine hydroxymethyltransferase (SHMT), whose mitochondrial isoform is strongly upregulated in cancer. Here we report the SHMT inhibitor SHIN2 and demonstrate its in vivo target engagement with 13C-serine tracing. As methotrexate is standard treatment for T-cell acute lymphoblastic leukemia (T-ALL), we explored the utility of SHIN2 in this disease. SHIN2 increases survival in NOTCH1-driven mouse primary T-ALL in vivo. Low dose methotrexate sensitizes Molt4 human T-ALL cells to SHIN2, and cells rendered methotrexate resistant in vitro show enhanced sensitivity to SHIN2. Finally, SHIN2 and methotrexate synergize in mouse primary T-ALL and in a human patient-derived xenograft in vivo, increasing survival. Thus, SHMT inhibition offers a complementary strategy in the treatment of T-ALL.

Isocotoin suppresses hepatitis E virus replication through inhibition of heat shock protein 90.

Hepatitis E virus (HEV) causes 14 million infections and 60,000 deaths per year globally, with immunocompromised persons and pregnant women experiencing severe symptoms. Although ribavirin can be used to treat chronic hepatitis E, toxicity in pregnant patients and the emergence of resistant strains are major concerns. Therefore there is an imminent need for effective HEV antiviral agents. The aims of this study were to develop a drug screening platform and to discover novel approaches to targeting steps within the viral life cycle. We developed a screening platform for molecules inhibiting HEV replication and selected a candidate, isocotoin. Isocotoin inhibits HEV replication through interference with heat shock protein 90 (HSP90), a host factor not previously known to be involved in HEV replication. Additional work is required to understand the compound's translational potential, however this suggests that HSP90-modulating molecules, which are in clinical development as anti-cancer agents, may be promising therapies against HEV.

Characterization of Tauopathy in a Rat Model of Post-Stroke Dementia Combining Acute Infarct and Chronic Cerebral Hypoperfusion.

Post-stroke dementia (PSD) is a major neurodegenerative consequence of stroke. Tauopathy has been reported in diverse neurodegenerative diseases. We investigated the cognitive impairment and pathomechanism associated with tauopathy in a rat model of PSD by modeling acute ischemic stroke and underlying chronic cerebral hypoperfusion (CCH). We performed middle cerebral artery occlusion (MCAO) surgery in rats to mimic acute ischemic stroke, followed by bilateral common carotid artery occlusion (BCCAo) surgery to mimic CCH. We performed behavioral tests and focused on the characterization of tauopathy through histology. Parenchymal infiltration of cerebrospinal fluid (CSF) tracers after intracisternal injection was examined to evaluate glymphatic function. In an animal model of PSD, cognitive impairment was aggravated when BCCAo was combined with MCAO. Tauopathy, manifested by tau hyperphosphorylation, was prominent in the peri-infarct area when CCH was combined. Synergistic accentuation of tauopathy was evident in the white matter. Microtubules in the neuronal axon and myelin sheath showed partial colocalization with the hyperphosphorylated tau, whereas oligodendrocytes showed near-complete colocalization. Parenchymal infiltration of CSF tracers was attenuated in the PSD model. Our experimental results suggest a hypothesis that CCH may aggravate cognitive impairment and tau hyperphosphorylation in a rat model of PSD by interfering with tau clearance through the glymphatic system. Therapeutic strategies to improve the clearance of brain metabolic wastes, including tau, may be a promising approach to prevent PSD after stroke.

A small molecule G6PD inhibitor reveals immune dependence on pentose phosphate pathway.

Glucose is catabolized by two fundamental pathways, glycolysis to make ATP and the oxidative pentose phosphate pathway to make reduced nicotinamide adenine dinucleotide phosphate (NADPH). The first step of the oxidative pentose phosphate pathway is catalyzed by the enzyme glucose-6-phosphate dehydrogenase (G6PD). Here we develop metabolite reporter and deuterium tracer assays to monitor cellular G6PD activity. Using these, we show that the most widely cited G6PD antagonist, dehydroepiandosterone, does not robustly inhibit G6PD in cells. We then identify a small molecule (G6PDi-1) that more effectively inhibits G6PD. Across a range of cultured cells, G6PDi-1 depletes NADPH most strongly in lymphocytes. In T cells but not macrophages, G6PDi-1 markedly decreases inflammatory cytokine production. In neutrophils, it suppresses respiratory burst. Thus, we provide a cell-active small molecule tool for oxidative pentose phosphate pathway inhibition, and use it to identify G6PD as a pharmacological target for modulating immune response.

Medical Procedure-Related Transient Global Amnesia.

BACKGROUND: Transient global amnesia (TGA) is an interesting clinical syndrome characterized by sudden memory loss for recent events and an inability to retain new memories usually lasting several hours and recovering spontaneously. We conducted a literature search of medical procedure-related TGA and its predisposing conditions. METHODS: We performed PubMed searches using the keyword "transient global amnesia" combined with "procedure," "test," "therapy," or various other individual medical procedures. In addition, we described 2 cases of gastroscopy-related TGA. RESULTS: Eighty-nine patients with medical procedure-related TGA in 49 articles were summarized. The most common procedure was cerebral angiography (n = 45), followed by coronary angiography (n = 10) and general anesthesia (n = 9). After categorization, neurological procedures were most common (n = 46, 51.7%), followed by cardiac (n = 17, 19.1%), anesthetic (n = 11, 12.4%), gastrointestinal (n = 4, 4.5%), and pulmonary (n = 2, 2.2%) procedures. CONCLUSIONS: Diverse cases of medical procedure-related TGA have been reported in the literature. Valsalva-associated activities, emotional stress with anxiety, and acute pain were predisposing conditions. An understanding of medical procedure-related TGA may be important for clinicians who perform such medical procedures.

Tyrosine kinase Fyn regulates iNOS expression in LPS-stimulated astrocytes via modulation of ERK phosphorylation.

The high concentrations of nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) in activated glial cells in response to neuroinflammatory stimuli have neurotoxic effects on the brain. At basal levels, iNOS expression is low, and proinflammatory stimuli induce iNOS expression in astrocytes, microglia, and oligodendrocytes. Fyn, a non-receptor tyrosine kinase, regulates iNOS expression in several types of immune cells. However, its role in stimulated astrocytes is less clear. In this study, we investigated the role of Fyn in the regulation of lipopolysaccharide (LPS)-induced iNOS expression in astrocytes from mice and rats. Intracerebroventricular LPS injections in cortical regions enhanced iNOS mRNA and protein levels, which were increased in Fyn-deficient mice. Accordingly, LPS-induced nitrite production was enhanced in primary astrocytes cultured from Fyn-deficient mice or rats. Similar results were observed in cultured astrocytes after the siRNA-induced knockdown of Fyn expression. Finally, we observed increased LPS-induced extracellular signal-regulated protein kinase (ERK) activation in Fyn-deficient astrocytes. These results suggested that Fyn has a regulatory role in iNOS expression in astrocytes during neuroinflammatory responses.

Chronic cerebral hypoperfusion induces post-stroke dementia following acute ischemic stroke in rats.

BACKGROUND: Post-stroke dementia (PSD) is one of the major consequences after stroke. Chronic cerebral hypoperfusion (CCH) can induce vascular cognitive impairment and potentiate amyloid pathology. We investigated how CCH contributes to the development of PSD after stroke in the context of neuroinflammation and amyloid pathology. METHODS: We designed a unique animal model for PSD. We performed middle cerebral artery occlusion (MCAO) surgery in rats mimicking acute territorial infarct, which was followed by bilateral common carotid artery occlusion (BCCAo) surgery mimicking CCH. We performed behavioral tests including neurologic function test and water maze task and histological investigations including neuroinflammation, neuronal cell death, amyloid pathology, and aquaporin 4 (AQP4) distribution. RESULTS: Spatial memory was synergistically impaired when BCCAo was superimposed on MCAO. Neuroinflammation with astroglial or microglial activation and amyloid pathology were enhanced in the ipsilateral cortex, thalamus, and hippocampus when BCCAo was superimposed on MCAO. Glymphatic pathway-related AQP4 distribution changed from perivascular to parenchymal pattern. CONCLUSIONS: Our experimental results suggest that CCH may contribute to the development of PSD by interfering with amyloid clearance through the glymphatic pathway and concomitant neuroinflammation. Therapeutic strategy to clear brain metabolic waste through the glymphatic pathway may be a promising approach to prevent PSD after stroke.

Human SHMT inhibitors reveal defective glycine import as a targetable metabolic vulnerability of diffuse large B-cell lymphoma.

The enzyme serine hydroxymethyltransferse (SHMT) converts serine into glycine and a tetrahydrofolate-bound one-carbon unit. Folate one-carbon units support purine and thymidine synthesis, and thus cell growth. Mammals have both cytosolic SHMT1 and mitochondrial SHMT2, with the mitochondrial isozyme strongly up-regulated in cancer. Here we show genetically that dual SHMT1/2 knockout blocks HCT-116 colon cancer tumor xenograft formation. Building from a pyrazolopyran scaffold that inhibits plant SHMT, we identify small-molecule dual inhibitors of human SHMT1/2 (biochemical IC50 ∼ 10 nM). Metabolomics and isotope tracer studies demonstrate effective cellular target engagement. A cancer cell-line screen revealed that B-cell lines are particularly sensitive to SHMT inhibition. The one-carbon donor formate generally rescues cells from SHMT inhibition, but paradoxically increases the inhibitor's cytotoxicity in diffuse large B-cell lymphoma (DLBCL). We show that this effect is rooted in defective glycine uptake in DLBCL cell lines, rendering them uniquely dependent upon SHMT enzymatic activity to meet glycine demand. Thus, defective glycine import is a targetable metabolic deficiency of DLBCL.

Longitudinal treatment patterns with ADP receptor inhibitors after myocardial infarction: Insights from the Canadian Observational AntiPlatelet sTudy.

BACKGROUND: After myocardial infarction (MI) treated with percutaneous coronary intervention (PCI), guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and an ADP receptor inhibitor (ADPri) for at least 1year. However, whether real-world Canadian practice patterns reflect this recommendation is unknown. METHODS: We studied 2175 MI patients treated with PCI and discharged from 26 Canadian hospitals between 12/2011 and 05/2013 in the Canadian Observational Antiplatelet sTudy (COAPT). Hierarchical Cox proportional hazard regression modeling was used to determine baseline demographic and clinical factors associated with duration of ADPri therapy post-discharge. RESULTS: At index-hospitalization discharge, 1597 (73%) patients were treated with clopidogrel, 220 (10%) with prasugrel, and 358 (17%) with ticagrelor. ADPri was discontinued prior to 1year in 474 (21.8%) patients; discontinuation rates were lowest for patients discharged on prasugrel (17.7%), compared with clopidogrel (22.5%) or ticagrelor (21.0%), (log rank test, p=0.03). In addition to regional variability, factors associated with shorter ADPri duration included older age, low body weight, Killip III/IV heart failure, atrial fibrillation, ticagrelor on discharge, and bare metal stent use, while longer ADPri duration was associated with history of prior MI. CONCLUSIONS: One in five PCI-treated MI patients did not complete Canadian guideline-recommended 1-year course of ADPri treatment. Premature ADPri discontinuation was most strongly associated with factors that increase the risk of bleeding. Further study is required to assess the clinical implications of premature ADPri discontinuation on patient outcomes.

Role of neuronal NADPH oxidase 1 in the peri-infarct regions after stroke.

The molecular mechanism underlying the selective vulnerability of neurons to oxidative damage caused by ischemia-reperfusion (I/R) injury remains unknown. We sought to determine the role of NADPH oxidase 1 (Nox1) in cerebral I/R-induced brain injury and survival of newborn cells in the ischemic injured region. Male Wistar rats were subjected to 90 min middle cerebral artery occlusion (MCAO) followed by reperfusion. After reperfusion, infarction size, level of superoxide and 8-hydroxy-2'-deoxyguanosine (8-oxo-2dG), and Nox1 immunoreactivity were determined. RNAi-mediated knockdown of Nox1 was used to investigate the role of Nox1 in I/R-induced oxidative damage, neuronal death, motor function recovery, and ischemic neurogenesis. After I/R, Nox1 expression and 8-oxo-2dG immunoreactivity was increased in cortical neurons of the peri-infarct regions. Both infarction size and neuronal death in I/R injury were significantly reduced by adeno-associated virus (AAV)-mediated transduction of Nox1 short hairpin RNA (shRNA). AAV-mediated Nox1 knockdown enhanced functional recovery after MCAO. The level of survival and differentiation of newborn cells in the peri-infarct regions were increased by Nox1 inhibition. Our data suggest that Nox-1 may be responsible for oxidative damage to DNA, subsequent cortical neuronal degeneration, functional recovery, and regulation of ischemic neurogenesis in the peri-infarct regions after stroke.

The effect of cilostazol on carotid intima-media thickness progression in patients with symptomatic intracranial atherosclerotic stenosis.

BACKGROUND: The progression of carotid intima-media thickness (CIMT) is closely associated with ischemic stroke recurrence. However, the efficacy of cilostazol on preventing CIMT progression in stroke patients has never been investigated properly by a prospective trial. METHODS: This study is a part of "Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis-2." Six centers that are available to measure CIMT according to the protocol participated in this substudy. After 7 months of randomization, the changes of CIMT were compared between cilostazol group and clopidogrel group. CIMT was measured by a semiautomated software (Intimascope) and was presented as the mean of maximum (CIMT-max) and average (CIMT-ave) of both common carotid arteries. Linear logistic regression analysis and analysis of covariance were performed to verify the independent factors associated with CIMT progression. RESULTS: Among the 85 patients, 39 subjects were assigned to cilostazol group and 46 subjects to clopidogrel group. Follow-up CIMT significantly decreased in cilostazol group (CIMT-max: -.03 ± .11 and CIMT-ave: -.02 ± .08) compared with the increase in clopidogrel group (CIMT-max: .04 ± .20 and CIMT-ave: .04 ± .11; P = .05 and P = .04, respectively). Female, diabetes, and smoking were independently associated with the progression of CIMT, whereas the use of cilostazol was against CIMT progression from the results of linear regression analysis (P = .03 for both CIMT-max and CIMT-ave). The use of cilostazol also well predicted less progression of CIMT at follow-up after adjusting for baseline CIMT values and conventional risk factors (CIMT-max: P = .04 and CIMT-ave: P = .03). CONCLUSION: Cilostazol has a beneficial effect in preventing the progression of CIMT in ischemic stroke patients.

NADPH oxidase 1, a novel molecular source of ROS in hippocampal neuronal death in vascular dementia.

AIMS: Chronic cerebral hypoperfusion (CCH) is a common pathological factor that contributes to neurodegenerative diseases such as vascular dementia (VaD). Although oxidative stress has been strongly implicated in the pathogenesis of VaD, the molecular mechanism underlying the selective vulnerability of hippocampal neurons to oxidative damage remains unknown. We assessed whether the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) complex, a specialized superoxide generation system, plays a role in VaD by permanent ligation of bilateral common carotid arteries in rats. RESULTS: Male Wistar rats (10 weeks of age) were subjected to bilateral occlusion of the common carotid arteries (two-vessel occlusion [2VO]). Nox1 expression gradually increased in hippocampal neurons, starting at 1 week after 2VO and for approximately 15 weeks after 2VO. The levels of superoxide, DNA oxidation, and neuronal death in the CA1 subfield of the hippocampus, as well as consequential cognitive impairment, were increased in 2VO rats. Both inhibition of Nox by apocynin, a putative Nox inhibitor, and adeno-associated virus-mediated Nox1 knockdown significantly reduced 2VO-induced reactive oxygen species generation, oxidative DNA damage, hippocampal neuronal degeneration, and cognitive impairment. INNOVATION AND CONCLUSION: We provided evidence that neuronal Nox1 is activated in the hippocampus under CCH, causing oxidative stress and consequential hippocampal neuronal death and cognitive impairment. This evidence implies that Nox1-mediated oxidative stress plays an important role in neuronal cell death and cognitive dysfunction in VaD. Nox1 may serve as a potential therapeutic target for VaD.

Proteinase 3 induces oxidative stress-mediated neuronal death in rat primary cortical neuron.

The recruitment of neutrophils into the cerebral microcirculation occurs, especially, in acute brain diseases like a focal cerebral ischemia and plays important role in pathological processes. Proteinase 3 is one of the three major proteinases expressed in neutrophils but no reports are available whether proteinase 3 can modulate neuronal survival. In this study, treatment of cultured rat primary cortical neuron with proteinase 3 induced overt reactive oxygen species production and decreased total glutathione contents as well as disruption of mitochondrial transmembrane potential. Proteinase 3 induced neuronal cell death as evidenced by MTT analysis as well as propidium iodide staining, which was prevented by pretreatment with an antioxidant, N-acetyl cysteine. Proteinase 3 increased activation of procaspase-3 and altered expression level of apoptotic regulator proteins, such as Bcl-2, Bax, and Bcl-xL. Similar to in vitro data, a direct microinjection of proteinase 3 into striatum of rat brain induced neuronal death, which was mediated by reactive oxygen species. These results suggest that proteinase 3 is new essential regulator of neuronal cell death pathway in a condition of excess neutrophil encounter in neuroinflammatory conditions.

Multiple biological properties of macelignan and its pharmacological implications.

Macelignan found in the nutmeg mace of Myristica fragrans obtains increasing attention as a new avenue in treating various diseases. Macelignan has been shown to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anti-cancer, anti-diabetes, and hepatoprotective activities; recently, it has also been shown to have neuroprotective activities. This review summarizes the current research on the biological effects of macelignan derived from M. fragrans, with emphasis on the importance in understanding and treating complex diseases such as cancer and Alzheimer's disease.