Bioinformatic identification and experiment validation reveal 6 hub genes, promising diagnostic and therapeutic targets for Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease that can cause dementia. We aim to screen out the hub genes involved in AD based on microarray datasets. METHODS: Gene expression profiles GSE5281 and GSE28146 were retrieved from Gene Expression Omnibus database to acquire differentially expressed genes (DEGs). Gene Ontology and pathway enrichment were conducted using DAVID online tool. The STRING database and Cytoscape tools were employed to analyze protein-protein interactions and identify hub genes. The predictive value of hub genes was assessed by principal component analysis and receiver operating characteristic curves. AD mice model was constructed, and histology was then observed by hematoxylin-eosin staining. Gene expression levels were finally determined by real-time quantitative PCR. RESULTS: We obtained 197 overlapping DEGs from GSE5281 and GSE28146 datasets. After constructing protein-protein interaction network, three highly interconnected clusters were identified and 6 hub genes (RBL1, BUB1, HDAC7, KAT5, SIRT2, and ITGB1) were selected. The hub genes could be used as basis to predict AD. Histological abnormalities of brain were observed, suggesting successful AD model was constructed. Compared with the control group, the mRNA expression levels of RBL1, BUB1, HDAC7, KAT5 and SIRT2 were significantly increased, while the mRNA expression level of ITGB1 was significantly decreased in AD groups. CONCLUSION: RBL1, BUB1, HDAC7, KAT5, SIRT2 and ITGB1 are promising gene signatures for diagnosis and therapy of AD.

Factors Influencing Mental Health Among Chinese Medical and Non-medical Students in the Early Stage of the COVID-19 Pandemic.

Background: The 2019 coronavirus disease (COVID-19) pandemic is a public health emergency of international concern. This study aimed to assess the psychological outcomes and their influencing factors among medical and non-medical University students during the COVID-19 pandemic in China. Methods: A cross-sectional online survey using structured questionnaires was conducted from February 20 to March 20, 2020. Psychological outcomes were assessed according to the Depression, Anxiety, and Stress Scale (DASS-21). Influencing factors were assessed by COVID-19 knowledge, mindful coping scale, and sense of control scale. Results: Our sample is comprised of 563 University students (male = 172, mean age = 21.52). Among them, 382 are medical students. Among the participants, 12.26, 18.47, and 8.53% have moderate to severe levels of depression, anxiety, and stress symptoms, respectively. Compared with the non-medical students, the medical students had a higher knowledge level of COVID-19, a higher sense of awareness, and fewer mental health symptoms. After controlling the covariance, perceived constraints of sense of control were negatively associated with depression, anxiety, and stress among both medical and non-medical students. Prevention of negative emotions by mindful coping was negatively associated with depression and anxiety among non-medical students. Knowledge of COVID-19 is not associated with mental distress among medical and non-medical students. Conclusions: During the COVID-19 pandemic in China, the mental health of University students was affected. Our findings suggested that a sense of control is a protective factor for both medical and non-medical students, while mindful coping is a protective factor for only non-medical students.

Conversion of Reactive Astrocytes to Induced Neurons Enhances Neuronal Repair and Functional Recovery After Ischemic Stroke.

The master neuronal transcription factor NeuroD1 can directly reprogram astrocytes into induced neurons (iNeurons) after stroke. Using viral vectors to drive ectopic ND1 expression in gliotic astrocytes after brain injury presents an autologous form of cell therapy for neurodegenerative disease. Cultured astrocytes transfected with ND1 exhibited reduced proliferation and adopted neuronal morphology within 2-3 weeks later, expressed neuronal/synaptic markers, and extended processes. Whole-cell recordings detected the firing of evoked action potentials in converted iNeurons. Focal ischemic stroke was induced in adult GFAP-Cre-Rosa-YFP mice that then received ND1 lentivirus injections into the peri-infarct region 7 days after stroke. Reprogrammed cells did not express stemness genes, while 2-6 weeks later converted cells were co-labeled with YFP (constitutively activated in astrocytes), mCherry (ND1 infection marker), and NeuN (mature neuronal marker). Approximately 66% of infected cells became NeuN-positive neurons. The majority (~80%) of converted cells expressed the vascular glutamate transporter (vGLUT) of glutamatergic neurons. ND1 treatment reduced astrogliosis, and some iNeurons located/survived inside of the savaged ischemic core. Western blotting detected higher levels of BDNF, FGF, and PSD-95 in ND1-treated mice. MultiElectrode Array (MEA) recordings in brain slices revealed that the ND1-induced reprogramming restored interrupted cortical circuits and synaptic plasticity. Furthermore, ND1 treatment significantly improved locomotor, sensorimotor, and psychological functions. Thus, conversion of endogenous astrocytes to neurons represents a plausible, on-site regenerative therapy for stroke.

Predictive Values of Serum Biochemical Markers and Apparent Diffusion Coefficient on Delayed Encephalopathy After Acute Carbon Monoxide Poisoning.

AIM: To explore the predictive values of serum biochemical markers and apparent diffusion coefficient (ADC) on delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). MATERIAL AND METHODS: Seventy-nine patients were divided into two groups based on the onset of DEACMP 60 days after with acute carbon monoxide poisoning. The baseline data of ACMP patients were collected. Serum levels of cardiac troponin I (cTNI), lactic acid (Lac), carboxyhemoglobin (COHb), creatine kinase (CK), creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH), C-reactive protein (CRP), and neuron-specific enolase (NSE) were measured within 24 hours of ACMP onset. The ADC of globus pallidum, centrum semiovale, and periventricular white matter were recorded by diffusion-weighted magnetic resonance imaging (DW-MRI) within 48 hours of admission. Logistic regression analysis was performed to determine the risk factors for DEACMP. RESULTS: The incidence of coma and duration of poisoning in the DEACMP group were significantly higher than those in the non-DEACMP group. The levels of Lac, CK, CK-MB, LDH, CRP and NSE in the DEACMP group were higher than those in the non- DEACMP group. The ADC value of globus pallidus in the DEACMP group was significantly higher than that in non-DEACMP group. The duration of poisoning, coma degree, CK, LDH, NES, and CRP were closely associated with the occurrence of DEACMP. CONCLUSION: The duration of poisoning, coma degree, and serum levels of CK, LDH, CRP, and NSE were independent risk factors for DEACMP.

Chemical Constituents from Tabernaemontana bufalina Lour.

Investigation of the branches and leaves of Tabernaemontana bufalina Lour. led to afford an undescribed monoterpenoid indole alkaloid, namely (3R,7S,14R,19S,20R)-19-hydroxypseudovincadifformine (1), and nine known metabolites (2-10). Their structures were determined by analysis of their NMR and ESI-MS spectra, and modified Mosher's and calculated electronic circular dichroism (ECD) methods were used for establishing the absolute configuration of compound 1. Their cytotoxic activities were assayed using two cancer cell lines. As the results, cytotoxic activities on MDA-MB-231 and B16 cells showed IC50 values of 8.9 and 0.13 µm for 6, and of 20.3 and 11.7 µm for 9, respectively.

Chemical Constituents from Chloranthus anhuiensis and Their Cytotoxic Activities.

Three hiherto unknown phenylpropanoid compounds, namely (7S,8R)-1-(1-ethoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (1), (7S,8S)-1-(1-ethoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (2), and (7S,8R)-1-(1-methoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (3), along with 12 known compounds (4 - 15) were obtained from the extract of whole plant of Chloranthus anhuiensis. Among them, 7 and 13 were obtained from nature for the first time. The structures of these natural compounds were characterized by extensive spectroscopic analysis and calculated electronic circular dichroism (ECD) data. Furthermore, their cytotoxic and neuroprotective activities were evaluated using MDA-MB-231, 4T1, HepG2, and PC12 cell lines. Compounds 8 and 13 exhibited moderate cytotoxic activities against MDA-MB-231 cell line with the IC50 values of 39.7 and 25.8 µm, respectively. And all the isolated compounds have no neuroprotective activities.

Carotid Atherosclerotic Plaque Features in Patients with Acute Ischemic Stroke.

OBJECTIVE: To investigate the carotid atherosclerotic plaque features in patients with acute ischemic stroke. METHODS: A total of 288 patients meeting the included criteria were enrolled and divided into an ulcerated plaque group (n = 139) and a nonulcerated plaque group (n = 149). Patients in the ulcerated plaque group were further subdivided into <50% and ≥50% stenosis groups. Carotid plaque component characteristics including luminal stenosis, carotid plaque volume, hypoechoic plaque volume, and hyperechoic plaque volume were analyzed by color Doppler ultrasound measurement. Associations between ulcerated plaque and carotid plaque features were also evaluated. The relationships among the levels of MMP-9, hs-CRP, and carotid stenosis rate were detected by enzyme-linked immunosorbent assay. RESULTS: The plaque volume, hypoechoic plaque volume, and luminal stenosis in the ulcerated plaque group were higher than that of the nonulcerated plaque group (P < 0.05). Ulcerated plaque was positively associated with luminal stenosis, plaque volume, and hypoechoic plaque volume after adjusting for sex and age. The result remained similar after adjusting for age, sex, and carotid luminal stenosis. The levels of MMP-9 and hs-CRP in the ulcerated plaque group were significantly higher than those of the nonulcerated plaque group (P < 0.01). For the ulcerated plaque group, the higher the carotid stenosis rate, the higher the level of MMP-9 and hs-CRP. CONCLUSIONS: Higher carotid atherosclerosis plaque volume, hypoechoic plaque volume, and luminal carotid stenosis may be symptoms of ulcerated plaque. Increased MMP-9 and hs-CRP levels could be used as adjunctive therapies of carotid stenosis at the molecular level.

Downregulation of miR­146a promotes proliferation and migration of AOB­treated embryoid body via PDGFRA induction.

Antioxidant of bamboo leaves (AOB) has been proven to have antioxidant activity and an inhibitory effect on free radicals that induce deterioration of macromolecules. The multi­target regulation of microRNAs (miRs) in the complicated process of vasculogenesis and angiogenesis lead to the use of miRNA therapy in vascular development. In the present study, the role of miRNAs on early embryo vascular development upon AOB stimulation was investigated. For this purpose, mouse embryonic stem cells were spontaneously differentiated as embryoid bodies (EBs) and were examined by phase contrast microscopy. miR­146a mimic and scramble control were transfected into EBs and potential targets of miR­146a were predicted. Cell proliferation and migration were detected by cell viability and wound­healing and migration assays, respectively. Angiogenesis was determined by the Spheroid sprouting assay. It was demonstrated that EBs transfected with miR­146a mimic had an increased growth rate compared with the control cells. miR­146a­transfected cells were very susceptible to AOB treatment. Furthermore, among the predicted miR­146a targets, platelet­derived growth factor receptor alpha (PDGFRA) was identified as a bona fide target of miR­146a. In conclusion, PDGFRA was demonstrated to participate in the modulation of cell migration and proliferation of mouse EBs. The present study expanded the current understanding of AOB biology and elucidated the mechanisms underlying early embryo vascular development upon AOB stimulation.

Macrophage related cytokine expressions in depression mouse model induced by chronic unpredictable mild stress.

Depression is characterized by mental retardation, interest blank, hypoactivity, anxiety, appetite loss, sexual dysfunction, sleep disorders and other symptoms. The incidence of depressed patients has demonstrated an upward trend in recent years. Antidepressant drugs are commonly used in modern medicine, but they have the side effect of drug resistance. This study aims to explore the effect of acupuncture stimulation on expressions of macrophage-related cytokines in mice with depression induced by chronic unpredictable mild stress (CUMS), and to explore the underlying immunological mechanism. The CUMS model was successfully developed. The secretion of nuclear transcription factor-kB (NF-kB) and interleukin (IL)-8 increased significantly in the modeling group compared with the blank control group (P<0.05). However, no significant difference of tumor necrosis factor-α (TNF-α) concentration was found (P>0.05). After acupuncture treatment, the behavior indicator was improved and meanwhile, the levels of TNF-α, NF-κB, IL-8 decreased significantly compared with the sham group (P<0.05). Depression mice were given treatment of acupuncture, and the effect of behavior change was observed and the content of macrophage cytokine production was measured, respectively. These findings suggested that inflammatory cytokines secreted by peritoneal macrophages increased significantly in mild depression mice, which can be improved by stimulation with acupuncture.

Optogenetic stimulation of glutamatergic neuronal activity in the striatum enhances neurogenesis in the subventricular zone of normal and stroke mice.

Neurogenesis in the subventricular zone (SVZ) of the adult brain may contribute to tissue repair after brain injuries. Whether SVZ neurogenesis can be upregulated by specific neuronal activity in vivo and promote functional recovery after stroke is largely unknown. Using the spatial and cell type specific optogenetic technique combined with multiple approaches of in vitro, ex vivo and in vivo examinations, we tested the hypothesis that glutamatergic activation in the striatum could upregulate SVZ neurogenesis in the normal and ischemic brain. In transgenic mice expressing the light-gated channelrhodopsin-2 (ChR2) channel in glutamatergic neurons, optogenetic stimulation of the glutamatergic activity in the striatum triggered glutamate release into SVZ region, evoked membrane currents, Ca2+ influx and increased proliferation of SVZ neuroblasts, mediated by AMPA receptor activation. In ChR2 transgenic mice subjected to focal ischemic stroke, optogenetic stimuli to the striatum started 5days after stroke for 8days not only promoted cell proliferation but also the migration of SVZ neuroblasts into the peri-infarct cortex with increased neuronal differentiation and improved long-term functional recovery. These data provide the first morphological and functional evidence showing a unique striatum-SVZ neuronal regulation via a semi-phasic synaptic mechanism that can boost neurogenic cascades and stroke recovery. The benefits from stimulating endogenous glutamatergic activity suggest a novel regenerative strategy after ischemic stroke and other brain injuries.

Long-term survival and regeneration of neuronal and vasculature cells inside the core region after ischemic stroke in adult mice.

Focal cerebral ischemia results in an ischemic core surrounded by the peri-infarct region (penumbra). Most research attention has been focused on penumbra while the pattern of cell fates inside the ischemic core is poorly defined. In the present investigation, we tested the hypothesis that, inside the ischemic core, some neuronal and vascular cells could survive the initial ischemic insult while regenerative niches might exist many days after stroke in the adult brain. Adult mice were subjected to focal cerebral ischemia induced by permanent occlusion of distal branches of the middle cerebral artery (MCA) plus transient ligations of bilateral common carotid artery (CCA). The ischemic insult uniformly reduced the local cerebral blood flow (LCBF) by 90%. Massive cell death occurred due to multiple mechanisms and a significant infarction was cultivated in the ischemic cortex 24 h later. Nevertheless, normal or even higher levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) persistently remained in the core tissue, some NeuN-positive and Glut-1/College IV-positive cells with intact ultrastructural features resided in the core 7-14 days post stroke. BrdU-positive but TUNEL-negative neuronal and endothelial cells were detected in the core where extensive extracellular matrix infrastructure developed. Meanwhile, GFAP-positive astrocytes accumulated in the penumbra and Iba-1-positive microglial/macrophages invaded the core several days after stroke. The long term survival of neuronal and vascular cells inside the ischemic core was also seen after a severe ischemic stroke induced by permanent embolic occlusion of the MCA. We demonstrate that a therapeutic intervention of pharmacological hypothermia could save neurons/endothelial cells inside the core. These data suggest that the ischemic core is an actively regulated brain region with residual and newly formed viable neuronal and vascular cells acutely and chronically after at least some types of ischemic strokes.

Regulation of therapeutic hypothermia on inflammatory cytokines, microglia polarization, migration and functional recovery after ischemic stroke in mice.

Stroke is a leading threat to human life and health in the US and around the globe, while very few effective treatments are available for stroke patients. Preclinical and clinical studies have shown that therapeutic hypothermia (TH) is a potential treatment for stroke. Using novel neurotensin receptor 1 (NTR1) agonists, we have demonstrated pharmacologically induced hypothermia and protective effects against brain damages after ischemic stroke, hemorrhage stroke, and traumatic brain injury (TBI) in rodent models. To further characterize the mechanism of TH-induced brain protection, we examined the effect of TH (at ±33°C for 6h) induced by the NTR1 agonist HPI-201 or physical (ice/cold air) cooling on inflammatory responses after ischemic stroke in mice and oxygen glucose deprivation (OGD) in cortical neuronal cultures. Seven days after focal cortical ischemia, microglia activation in the penumbra reached a peak level, which was significantly attenuated by TH treatments commenced 30min after stroke. The TH treatment decreased the expression of M1 type reactive factors including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-12, IL-23, and inducible nitric oxide synthase (iNOS) measured by RT-PCR and Western blot analyses. Meanwhile, TH treatments increased the expression of M2 type reactive factors including IL-10, Fizz1, Ym1, and arginase-1. In the ischemic brain and in cortical neuronal/BV2 microglia cultures subjected to OGD, TH attenuated the expression of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α), two key chemokines in the regulation of microglia activation and infiltration. Consistently, physical cooling during OGD significantly decreased microglia migration 16h after OGD. Finally, TH improved functional recovery at 1, 3, and 7days after stroke. This study reveals the first evidence for hypothermia mediated regulation on inflammatory factor expression, microglia polarization, migration and indicates that the anti-inflammatory effect is an important mechanism underlying the brain protective effects of a TH therapy.

BmCREC is an endoplasmic reticulum (ER) resident protein and required for ER/Golgi morphology.

Silkworm posterior silkgland is a model for studying intracellular trafficking. Here, using this model, we identify several potential cargo proteins of BmKinesin-1 and focus on one candidate, BmCREC. BmCREC (also known as Bombyx mori DNA supercoiling factor, BmSCF) was previously proposed to supercoil DNA in the nucleus. However, we show here that BmCREC is localized in the ER lumen. Its C-terminal tetrapeptide HDEF is recognized by the KDEL receptor, and subsequently it is retrogradely transported by coat protein I (COPI) vesicles to the ER. Lacking the HDEF tetrapeptide of BmCREC or knocking down COPI subunits results in decreased ER retention and simultaneously increased secretion of BmCREC. Furthermore, we find that BmCREC knockdown markedly disrupts the morphology of the ER and Golgi apparatus and leads to a defect of posterior silkgland tube expansion. Together, our results clarify the ER retention mechanism of BmCREC and reveal that BmCREC is indispensable for maintaining ER/Golgi morphology.

SCG10 promotes non-amyloidogenic processing of amyloid precursor protein by facilitating its trafficking to the cell surface.

The processing of amyloid precursor protein (APP) is a key event in the pathogenesis of Alzheimer's disease. As certain cleavage pathways tend to occur in particular subcellular compartments, the processing of APP is greatly influenced by factors that regulate its trafficking. Here we report that SCG10 directly interacts with the KFFEQ motif of the APP intracellular domain and promotes the non-amyloidogenic processing of the APP. Knockdown of SCG10 led to decreases in α cleavage products, sAPPα and CTFα, while increases of both Aß1-40 and Aß1-42. Elevation of SCG10 induced APP accumulation in post-Golgi vesicles and on the cell surface by facilitating its secretory pathway. In addition, the APP processing was dependent on the palmitoylation-mediated membrane-anchoring of SCG10. Furthermore, elevation of SCG10 reduced Aß accumulation and amyloid plaque formation in the hippocampus of APPswe/PS1dE9 mice. Taken together, these results show that SCG10 has a potential role in preventing and treating Alzheimer's disease.

Identification of genes required for nonhost resistance to Xanthomonas oryzae pv. oryzae reveals novel signaling components.

BACKGROUND: Nonhost resistance is a generalized, durable, broad-spectrum resistance exhibited by plant species to a wide variety of microbial pathogens. Although nonhost resistance is an attractive breeding strategy, the molecular basis of this form of resistance remains unclear for many plant-microbe pathosystems, including interactions with the bacterial pathogen of rice, Xanthomonas oryzae pv. oryzae (Xoo). METHODS AND FINDINGS: Virus-induced gene silencing (VIGS) and an assay to detect the hypersensitive response (HR) were used to screen for genes required for nonhost resistance to Xoo in N. benthamiana. When infiltrated with Xoo strain YN-1, N. benthamiana plants exhibited a strong necrosis within 24 h and produced a large amount of H(2)O(2) in the infiltrated area. Expression of HR- and defense-related genes was induced, whereas bacterial numbers dramatically decreased during necrosis. VIGS of 45 ACE (Avr/Cf-elicited) genes revealed identified seven genes required for nonhost resistance to Xoo in N. benthamiana. The seven genes encoded a calreticulin protein (ACE35), an ERF transcriptional factor (ACE43), a novel Solanaceous protein (ACE80), a hydrolase (ACE117), a peroxidase (ACE175) and two proteins with unknown function (ACE95 and ACE112). The results indicate that oxidative burst and calcium-dependent signaling pathways play an important role in nonhost resistance to Xoo. VIGS analysis further revealed that ACE35, ACE80, ACE95 and ACE175, but not the other three ACE genes, interfered with the Cf-4/Avr4-dependent HR. CONCLUSIONS/SIGNIFICANCE: N. benthamiana plants inoculated with Xoo respond by rapidly eliciting an HR and nonhost resistance. The oxidative burst and other signaling pathways are pivotal in Xoo-N. benthamiana nonhost resistance, and genes involved in this response partially overlap with those involved in Cf/Avr4-dependent HR. The seven genes required for N. benthamiana-mediated resistance to Xoo provide a basis for further dissecting the molecular mechanism of nonhost resistance.