Diesel exhaust particle exposure exacerbates ciliary and epithelial barrier dysfunction in the multiciliated bronchial epithelium models.

Airway epithelium, the first defense barrier of the respiratory system, facilitates mucociliary clearance against inflammatory stimuli, such as pathogens and particulates inhaled into the airway and lung. Inhaled particulate matter 2.5 (PM2.5) can penetrate the alveolar region of the lung, and it can develop and exacerbate respiratory diseases. Although the pathophysiological effects of PM2.5 in the respiratory system are well known, its impact on mucociliary clearance of airway epithelium has yet to be clearly defined. In this study, we used two different 3D in vitro airway models, namely the EpiAirway-full-thickness (FT) model and a normal human bronchial epithelial cell (NHBE)-based air-liquid interface (ALI) system, to investigate the effect of diesel exhaust particles (DEPs) belonging to PM2.5 on mucociliary clearance. RNA-sequencing (RNA-Seq) analyses of EpiAirway-FT exposed to DEPs indicated that DEP-induced differentially expressed genes (DEGs) are related to ciliary and microtubule function and inflammatory-related pathways. The exposure to DEPs significantly decreased the number of ciliated cells and shortened ciliary length. It reduced the expression of cilium-related genes such as acetylated α-tubulin, ARL13B, DNAH5, and DNAL1 in the NHBEs cultured in the ALI system. Furthermore, DEPs significantly increased the expression of MUC5AC, whereas they decreased the expression of epithelial junction proteins, namely, ZO1, Occludin, and E-cadherin. Impairment of mucociliary clearance by DEPs significantly improved the release of epithelial-derived inflammatory and fibrotic mediators such as IL-1ß, IL-6, IL-8, GM-CSF, MMP-1, VEGF, and S100A9. Taken together, it can be speculated that DEPs can cause ciliary dysfunction, hyperplasia of goblet cells, and the disruption of the epithelial barrier, resulting in the hyperproduction of lung injury mediators. Our data strongly suggest that PM2.5 exposure is directly associated with ciliary and epithelial barrier dysfunction and may exacerbate lung injury.

Mumefural Improves Recognition Memory and Alters ERK-CREB-BDNF Signaling in a Mouse Model of Chronic Cerebral Hypoperfusion.

Cognitive impairment resulting from chronic cerebral hypoperfusion (CCH) is known as vascular dementia (VaD) and is associated with cerebral atrophy and cholinergic deficiencies. Mumefural (MF), a bioactive compound found in a heated fruit of Prunus mume Sieb. et Zucc, was recently found to improve cognitive impairment in a rat CCH model. However, additional evidence is necessary to validate the efficacy of MF administration for treating VaD. Therefore, we evaluated MF effects in a mouse CCH model using unilateral common carotid artery occlusion (UCCAO). Mice were subjected to UCCAO or sham surgery and orally treated with MF daily for 8 weeks. Behavioral tests were used to investigate cognitive function and locomotor activity. Changes in body and brain weights were measured, and levels of hippocampal proteins (brain-derived neurotrophic factor (BDNF), extracellular signal-regulated kinase (ERK), cyclic AMP-response element-binding protein (CREB), and acetylcholinesterase (AChE)) were assessed. Additionally, proteomic analysis was conducted to examine the alterations in protein profiles induced by MF treatment. Our study showed that MF administration significantly improved cognitive deficits. Brain atrophy was attenuated and MF treatment reversed the increase in AChE levels. Furthermore, MF significantly upregulated p-ERK/ERK, p-CREB/CREB, and BDNF levels after UCCAO. Thus, MF treatment ameliorates CCH-induced cognitive impairment by regulating ERK/CREB/BDNF signaling, suggesting that MF is a therapeutic candidate for treating CCH.

A time-dependently regulated gene network reveals that Aspergillus protease affects mitochondrial metabolism and airway epithelial cell barrier function via mitochondrial oxidants.

The airway epithelium maintains tight barrier integrity to prevent penetration of pathogens; thus, impairment of the barrier function is an important and common histological feature in asthmatic patients. Proteolytic allergens from fungi, pollen, and house dust mites can disrupt epithelial barrier integrity, but the mechanism remains unclear. Aspergillus oryzae protease (AP)-induced mitochondrial reactive oxygen species (ROS) contribute to the epithelial inflammatory response. However, as mitochondrial ROS affect various cellular functions, such as metabolism, cell death, cell proliferation, and redox homeostasis through signal transduction, it is difficult to understand the detailed action mechanism of AP by measuring changes in a single gene or protein of a specific signaling pathway. Moreover, mitochondrial ROS can directly oxidize DNA to activate transcription, thereby affecting the expression of various genes at the transcriptional level. Therefore, we conducted whole-genome analysis and used a network-based approach to understand the effect of AP and AP-induced mitochondrial ROS in human primary airway epithelial cells and to evaluate the mechanistic basis for AP-mediated epithelial barrier dysfunction. Our results indicate that production of mitochondrial ROS following AP exposure induce mitochondrial dysfunction at an early stage. Over time, changes in genome expression were further expanded without remaining mitochondrial ROS. Specifically, genes involved in the apoptotic functions and intercellular junctions were affected, consequently impairing the cellular barrier integrity. This change was recovered by scavenging mitochondrial ROS at an early point after exposure to AP. In conclusion, our findings indicate that instantly increased mitochondrial ROS at the time of exposure to allergenic proteases consequently induces epithelial barrier dysfunction at a later time point, resulting in pathological changes. These data suggest that antioxidant therapy administered immediately after exposure to proteolytic antigens may be effective in maintaining epithelial barrier function.

Differential Transcriptional Regulation of Polymorphic p53 Codon 72 in Metabolic Pathways.

p53 is a transcription factor that is activated under DNA damage stress and regulates the expression of proapoptotic genes including the expression of growth arrest genes to subsequently determine the fate of cells. To investigate the functional differences of polymorphic p53 codon 72, we constructed isogenic lines encoding each polymorphic p53 codon 72 based on induced pluripotent stem cells, which can endogenously express each polymorphic p53 protein only, encoding either the arginine 72 (R72) variant or proline 72 (P72) variant, respectively. We found that there was no significant functional difference between P72 and R72 cells in growth arrest or apoptosis as a representative function of p53. In the comprehensive analysis, the expression pattern of the common p53 target genes, including cell cycle arrest or apoptosis, was also increased regardless of the polymorphic p53 codon 72 status, whereas the expression pattern involved in metabolism was decreased and more significant in R72 than in P72 cells. This study noted that polymorphic p53 codon 72 differentially regulated the functional categories of metabolism and not the pathways that determine cell fate, such as growth arrest and apoptosis in cells exposed to genotoxic stress.

Impaired Cognitive Flexibility Induced by Chronic Cerebral Hypoperfusion in the 5XFAD Transgenic Mouse Model of Mixed Dementia.

Cerebrovascular lesions are widely prevalent in patients with Alzheimer's disease (AD), but their relationship to the pathophysiology of AD remains poorly understood. An improved understanding of the interaction of cerebrovascular damage with AD is crucial for the development of therapeutic approaches. Herein, we investigated the effects of chronic cerebral hypoperfusion (CCH) in a 5XFAD transgenic (Tg) mouse model of AD. We established CCH conditions in both Tg and non-Tg mice by inducing unilateral common carotid artery occlusion (UCCAO). Cognitive performance in mice was evaluated, and their brain tissue was examined for amyloid-beta (Aß) pathology to elucidate possible mechanisms. We found that UCCAO-operated Tg mice showed impaired cognitive flexibility in the reversal phase of the hidden-platform water maze task compared to sham-operated Tg mice. Interestingly, UCCAO-operated Tg mice used fewer spatial cognitive strategies than sham-operated Tg mice during reversal learning. These cognitive deficits were accompanied by increased Aß plaque burden and Aß42 levels in the hippocampus and prefrontal cortex, 2 regions that play essential roles in the regulation of cognitive flexibility. Furthermore, changes in cognitive flexibility are strongly correlated with the expression levels of enzymes related to Aß clearance, such as neprilysin and insulin-degrading enzymes. These findings suggest that, in 5XFAD mice, impaired cognitive flexibility is related to CCH, and that Aß clearance might be involved in this process.

Elimination of Teratogenic Human Induced Pluripotent Stem Cells by Bee Venom via Calcium-Calpain Pathway.

Induced pluripotent stem cells (iPSCs) are regarded as a promising option for cell-based regenerative medicine. To obtain safe and efficient iPSC-based cell products, it is necessary to selectively eliminate the residual iPSCs prior to in vivo implantation due to the risk of teratoma formation. Bee venom (BV) has long been used in traditional Chinese medicine to treat inflammatory diseases and relieve pain, and has been shown to exhibit anti-cancer, anti-mutagenic, anti-nociceptive, and radioprotective activities. However, the potential benefits of BV in iPSC therapy, particularly its anti-teratoma activity, have not been examined. In this study, we found that BV selectively induced cell death in iPSCs, but not in iPSC-derived differentiated cells (iPSCs-Diff). BV rapidly disrupted cell membrane integrity and focal adhesions, followed by induction of apoptosis and necroptosis in iPSCs. We also found that BV remarkably enhanced intracellular calcium levels, calpain activation, and reactive oxygen speciesgeneration in iPSCs. BV treatment before in ovo grafting efficiently prevented iPSC-derived teratoma formation. In contrast, no DNA damage was observed in iPSCs-Diff following BV treatment, further demonstrating the safety of BV for use with iPSCs-Diff. Taken together, these findings show that BV has potent anti-teratoma activity by eliminating residual iPSCs, and can be used for the development of effective and safe iPSC-based cell therapies.

Similarity of therapeutic networks induced by a multi-component herbal remedy, Ukgansan, in neurovascular unit cells.

The neurovascular unit, which includes neurons, glial cells, and vascular cells, plays crucial roles in the onset and progression of Alzheimer's disease (AD). Therefore, effective drugs against AD should be able to target the multi-cellular neurovascular unit and the therapeutic relationships among neurovascular cells should be defined. Here, we examined the therapeutic effects of Ukgansan (UGS), an herbal remedy with multi-targeting capabilities, using in vitro neurovascular unit models and an in vivo model of AD. In addition, we compared the therapeutic networks induced by UGS and its components in different neurovascular cell types. We found that UGS and its components protected neurovascular cells against diverse damaging agents and improved the behavioral patterns of AD model mice. A comparison of UGS- or its components-induced therapeutic networks, constructed from high-throughput data on gene expression, pathway activity, and protein phosphorylation, revealed similarities among neurovascular cell types, especially between BV-2 microglia and HBVP (human brain vascular pericytes). These findings, together with the functional connections between neurovascular cells, can explain the therapeutic effects of UGS. Furthermore, they suggest underlying similarities in the therapeutic mechanisms in different neurovascular cell types.

Bakuchiol Suppresses Inflammatory Responses Via the Downregulation of the p38 MAPK/ERK Signaling Pathway.

The purpose of the present study was to evaluate the effects of bakuchiol on the inflammatory response and to identify the molecular mechanism of the inflammatory effects in a lipopolysaccharide (LPS)-stimulated BV-2 mouse microglial cell line and mice model. The production of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay. The mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6 was measured using reverse transcription-polymerase chain reaction analysis. Mitogen-activated protein kinase (MAPK) phosphorylation was determined by western blot analysis. In vitro experiments, bakuchiol significantly suppressed the production of PGE2 and IL-6 in LPS-stimulated BV-2 cells, without causing cytotoxicity. In parallel, bakuchiol significantly inhibited the LPS-stimulated expression of iNOS, COX-2, and IL-6 in BV-2 cells. However, bakuchiol had no effect on the LPS-stimulated production and mRNA expression of TNF-α or on LPS-stimulated c-Jun NH2-terminal kinase phosphorylation. In contrast, p38 MAPK and extracellular signal-regulated kinase (ERK) phosphorylation were inhibited by bakuchiol. In vivo experiments, Bakuchiol reduced microglial activation in the hippocampus and cortex tissue of LPS-injected mice. Bakuchiol significantly suppressed LPS-injected production of TNF-α and IL-6 in serum. These results indicate that the anti-neuroinflammatory effects of bakuchiol in activated microglia are mainly regulated by the inhibition of the p38 MAPK and ERK pathways. We suggest that bakuchiol may be beneficial for various neuroinflammatory diseases.

Annona atemoya Leaf Extract Improves Scopolamine-Induced Memory Impairment by Preventing Hippocampal Cholinergic Dysfunction and Neuronal Cell Death.

We explored the preventative effect of Annona atemoya leaf (AAL) extract on memory impairment in a scopolamine (SCO)-induced cognitive deficit mouse model. Fifty-eight mice were randomly divided into six groups and orally treated with AAL extract at (50, 100, or 200 mg/kg) or tacrine (TAC) for 21 days. Memory deficits were induced by a single injection of 1 mg/kg SCO (i.p.) and memory improvement was evaluated by using behavioral tests such as the passive avoidance task and Y-maze test. The levels of cholinergic functions, neuronal cell death, reactive oxygen species, and protein expression related to hippocampal neurogenesis were examined by immunohistochemical staining and western blotting. The administration of AAL extract improved memory impairment according to increased spontaneous alternation in the Y-maze and step-through latency in passive avoidance test. AAL extract treatment increased the acetylcholine content, choline acetyltransferase, and acetylcholinesterase activity in the hippocampus of SCO-stimulated mice. In addition, AAL extract attenuated oxidative stress-induced neuronal cell death of hippocampal tissue. In terms of the regulatory mechanisms, AAL extract treatment reversed the SCO-induced decreases in the expression of Akt, phosphorylation of cAMP response element binding protein, and brain-derived neurotrophic factor. Our findings demonstrate that AAL extract has the ability to alleviate memory impairment through preventative effect on cholinergic system dysfunction and oxidative stress-related neuronal cell death in a SCO-induced memory deficit animal model. Overall, AAL may be a promising plant resource for the managing memory dysfunction due to neurodegenerative diseases, such as Alzheimer's disease (AD).

Elaeagnus glabra f. oxyphylla Attenuates Scopolamine-Induced Learning and Memory Impairments in Mice by Improving Cholinergic Transmission via Activation of CREB/NGF Signaling.

We aimed to investigate the therapeutic effects of an Elaeagnus glabra f. oxyphylla (EGFO) ethanol extract in mice with scopolamine-induced memory dysfunction. Fifty male mice were randomly divided into a normal control group, a scopolamine-treated group, a scopolamine and EGFO extract-treated group, and a scopolamine and tacrine-treated group. EGFO (50 or 100 mg/kg/day) was received for 21 days. Step-through passive avoidance and Y-maze tests were performed to examine the effects of treatment on learning and memory impairments. Acetylcholine (Ach) levels and acetylcholinesterase (AchE) activity were measured via an enzyme-linked immunosorbent assay (ELISA). Levels of choline acetyltransferase (ChAT), nerve growth factor (NGF), cAMP response element-binding protein (CREB), and apoptosis-related protein expression were determined via Western blot analysis. EGFO pretreatment significantly attenuated scopolamine-induced memory impairments, relative to findings observed in the scopolamine-treated group. Levels of cholinergic factors in the brain tissues were markedly attenuated in the scopolamine-treated group. EGFO treatment also attenuated neural apoptosis in scopolamine-treated mice by decreasing the expression of apoptosis-related proteins such as Bax, Bcl2, cleaved caspase-3, and TUNEL staining. These results suggest that EGFO improves memory and cognition in a mouse model of memory impairment by restoring cholinergic and anti-apoptotic activity, possibly via activation of CREB/NGF signaling.

Comprehensive analysis of transcriptomic changes induced by low and high doses of bisphenol A in HepG2 spheroids in vitro and rat liver in vivo.

Bisphenol A (BPA), a synthetic monomer commonly included in the daily products, has a structure similar to the estrogen receptor agonist. Therefore BPA has been anticipated to interfere with the hormone metabolisms and cause diverse pathological conditions. But the effects of BPA on the genetic landscapes of liver or hepatic cells have not been fully established. Gene expressional changes induced by low- or high-dose of BPA were evaluated in 3D cultured human hepatoma cells (HepG2 spheroids) in vitro at 0, 0.5, 5 and 200 µM and liver of rats exposed to BPA at 0, 0.5 and 250 mg/kg for 90 days in vivo. Functional enrichment analysis, pathway activity measurement and network analysis were performed using BPA-responsive genes. Treatment with BPA changed a lot of gene expressions in both HepG2 spheroids and rat livers depending on doses of BPA. Functional enrichment and pathway analysis show that lipid or steroid metabolism-related functions were altered by BPA in both HepG2 spheroids and livers of rats. Lipid metabolism-related functions altered by BPA formed a large cluster encompassing lipid biosynthesis, steroid metabolic process and cholesterol regulation process. It was also observed that distribution of pathway activities was correlated between HepG2 spheroids and rat livers at low-dose of BPA. Distance distribution in protein-protein interaction network also evidenced the closeness of BPA-responsive genes to metabolism pathways which include lipid metabolism. Collectively, we demonstrated that BPA greatly influenced overall gene expression and biological functions in both human hepatoma spheroids and rat liver, in which lipid- or steroid metabolism-associated genes were significantly altered by the exposure to BPA.

Hwangryunhaedok-Tang Exerts Neuropreventive Effect on Memory Impairment by Reducing Cholinergic System Dysfunction and Inflammatory Response in a Vascular Dementia Rat Model.

Hwangryunhaedok-tang (HRT) is a traditional oriental herbal formula used in Asian countries for treating inflammatory diseases and controlling fever. Our present study aimed to determine whether HRT has therapeutic effects for patients with vascular dementia (VaD) using a bilateral common carotid artery occlusion (BCCAO) rat model and assessing spatial memory impairment and activation of neuroinflammation. BCCAO was performed in male Sprague Dawley rats to induce VaD, and oral HRT was administered daily for 30 d. Our data showed that HRT ameliorated BCCAO-induced memory and cognitive impairment in behavioral tests. In addition, HRT reversed cholinergic dysfunction and neuronal damage in the hippocampus of BCCAO rats. Furthermore, HRT attenuated microglial activation and reduced the phosphorylation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase (JNK) induced by BCCAO. Simultaneous high-performance liquid chromatography analysis of HRT using index compounds from the herbal composition revealed that both HRT ethanol extract and commercial HRT granules primarily comprise geniposide, baicalin, and berberine. Our study showed that HRT administration resulted in the prevention of neuronal injury induced by BCCAO through improvement of cholinergic dysfunction and inhibition of neuroinflammatory responses, suggesting that HRT may have potential as a treatment for VaD.

K120R mutation inactivates p53 by creating an aberrant splice site leading to nonsense-mediated mRNA decay.

The point mutation that substitutes lysine with arginine at position 120 of human p53 has been characterized as a missense mutation. The K120R mutation renders the p53 protein disabled for acetylation and, as a result, defective for apoptotic function, which provides a mechanistic link between the missense mutation and tumorigenesis. However, we noticed the failures of tumorigenesis in mice with the mutation, and of the related studies to notice that it has arbitrarily reflected in amino acid change through a sequence modification (AGA) of the original tumor mutation (AGG) by codon degeneracy. Unlike this modified version, we also discovered a novel splicing site the original mutation, TP53 c.359A>G, may induce. Using a human induced pluripotent stem cell line that was engineered to be homozygous for the original mutation, we here identified that the accidental splicing site generates a defective transcript variant with a frame-shifted premature termination codon which is subjected to nonsense-mediated mRNA decay. The authentic splicing still occurs but in extremely low amounts. Taken together, this mutation causes depletion of cellular p53 via defective mRNA, suggesting a new link to tumorigenesis.

Bojungikgi-Tang, a Traditional Herbal Formula, Exerts Neuroprotective Effects and Ameliorates Memory Impairments in Alzheimer's Disease-Like Experimental Models.

Bojungikgi-tang (BJIGT; Bu Zhong Yi Qi Tang in China, Hochuekkito in Japan) is a traditional Oriental herbal formula comprised of eight medicinal herbs that has long been used for the treatment of digestive disorders. A recent clinical study from South Korea reported that BJIGT-gamibang administration may be effective in treating dementia. We aimed to establish scientific evidence for the anti-dementia effects of BJIGT using in vitro and in vivo experimental models. We measured amyloid- ß (Aß) aggregation, ß-secretase (BACE), and antioxidant activity in a cell free system. Neuroprotective effects were assessed using CCK-8. Imprinting control region (ICR) mice were divided into the following six groups: Normal control, Aß-injected, Aß-injection + oral BJIGT gavage (200, 400, or 800 mg/kg/day), and Aß-injection + oral morin administration (10 mg/kg/day). Subsequently, behavioral evaluations were conducted and brain samples were collected from all the animals and assessed. BJIGT enhanced inhibition of Aß aggregation and BACE activity in vivo, as well as antioxidant activity in in vitro, cell-free systems. BJIGT also exerted neuroprotective effects in a hydroperoxide (H2O2)-induced damaged HT22 hippocampal cell line model. In addition, BJIGT administration significantly ameliorated cognitive impairments in Aß-injected mice, as assessed by the passive avoidance and Y-maze tests. Furthermore, BJIGT treatment suppressed Aß aggregation and expression, as well as expression of Aß, NeuN, and brain-derived neurotrophic factor (BDNF) in the hippocampi of Aß-injected mice. Overall, our results demonstrate that, with further testing in clinical populations, BJIGT may have great utility for the treatment of dementia and especially Alzheimer's disease.

Simultaneous Determination of the Traditional Herbal Formula Ukgansan and the In Vitro Antioxidant Activity of Ferulic Acid as an Active Compound.

Ukgansan (UGS), a traditional herbal formula composing seven medicinal herbal plants, has been applied in Asian countries for treating neurosis, insomnia, and irritability. Here, the current study performed a simultaneous determination of the seven marker compounds (liquiritin apioside, liquiritin, ferulic acid, glycyrrhizin, decursin, decursinol angelate, and atractylenolide I) using high-performance liquid chromatography (HPLC), to establish quality control of UGS. A 70% ethanol extract of UGS and a mixture of the seven compounds were separated using a C-18 analytical column on a gradient solvent system of 1.0% (v/v) aqueous acetic acid and acetonitrile. Data were recorded at a UV wavelength of 250 nm for glycyrrhizin; 276 nm for liquiritin apioside, liquiritin, and atractylenolide I; and 325 nm for ferulic acid, decursin, and decursinol angelate. The results exhibited high linearity (correlation coefficient (r²) ≥ 0.9998) and proper precision (0.38⁻3.36%), accuracy (95.12⁻105.12%), and recovery (95.99⁻104.94%) for the seven marker compounds. The amount of the seven marker compounds at the concentrations from 0.190 to 16.431 mg/g. In addition, the current study evaluated the antioxidant effects of UGS by measuring their scavenging activities against the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radicals using in vitro cell-free systems and observed its antioxidant activity. Among the seven components of the UGS extract, ferulic acid dramatically enhanced the scavenging of ABTS and DPPH radicals compared with other compounds. The concentrations of ferulic acid required for a 50% reduction (RC50) in ABTS and DPPH radicals were 16.22 µM and 41.21 µM, respectively. Furthermore, UGS extract exerted the neuroprotective effect and blocked the inflammatory response in neuronal hippocampal cells and microglia, respectively. Overall, the established method of HPLC will be valuable for improving the quality control of UGS extract, and ferulic acid may be useful as a potential antioxidant agent.

The Anti-neuroinflammatory Activity of Tectorigenin Pretreatment via Downregulated NF-κB and ERK/JNK Pathways in BV-2 Microglial and Microglia Inactivation in Mice With Lipopolysaccharide.

The activation of microglia is decisively involved with the neurodegeneration observed in many neuroinflammatory pathologies, such as multiple sclerosis, Parkinson's disease, and Alzheimer's disease. Tectorigenin (TEC) is an isoflavone isolated from various medicinal plants, such as Pueraria thunbergiana Benth, Belamcanda chinensis, and Iris unguicularis. In the present study, the neuroinflammatory effects of TEC were evaluated in both lipopolysaccharide (LPS)-treated BV-2 microglial and mouse models. TEC remarkably inhibited reactive oxygen species (ROS) generation. TEC also inhibits the production and expression of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in LPS-stimulated BV-2 cells. In addition, TEC suppressed the LPS-induced activation of nuclear factor-κB (NF-κB), phosphorylation of extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) to regulate the inflammatory mediators, such as inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6. These results indicate that TEC may inhibit neuronal inflammation through the downregulation of inflammatory mediators, including iNOS, COX-2, TNF-α, and IL-6 by suppressing NF-κB/ERK/JNK-related signaling pathways. Furthermore, cotreatment with TEC and ERK inhibitor SCH772984 or JNK inhibitor SP600125 suppressed the overproduction of LPS-induced NO production in BV-2 cells. Consistent with the results of in vitro experiments, an LPS-induced brain inflammation mouse model, administration of TEC effectively decrease the levels of malondialdehyde, iNOS in hippocampus, and prevented increases in the levels of TNF-α and IL-6 in the serum. TEC showed marked attenuation of microglial activation. Finally, TEC inhibited protein expression of toll-like receptor 4 and myeloid differentiation factor 88 in LPS-activated BV-2 microglia and mouse models. Taken altogether, the cumulative findings suggested that TEC holds the potential to develop as a neuroprotective drug for the intervention of neuroinflammatory disorders.

Evaluation of Animal Models by Comparison with Human Late-Onset Alzheimer's Disease.

Despite many efforts to alleviate the pathological conditions of Alzheimer's disease (AD), effective therapeutic drugs have not been developed, mainly because of the lack of molecular information about AD and animal models. We observed the reciprocal regulation of AD-associated genes (AD genes) and their related functions. Upregulated AD genes were positioned in central regions in the protein-protein interaction network and were involved in inflammation and DNA repair pathways. Downregulated AD genes positioned in the periphery of the network were associated with metabolic pathways. Using these features of AD genes, we found that 5×FAD, amyloid ß-injected mice, and rats in the initial phases after bilateral common carotid artery occlusion (BCCAO) exhibited patterns that were most similar to those of AD. In contrast, using differentially expressed genes from animal models, we observed that 3×Tg and animals in late phases of BCCAO were positioned close to AD genes.

Phytochemical allylguaiacol exerts a neuroprotective effect on hippocampal cells and ameliorates scopolamine-induced memory impairment in mice.

Allylguaiacol is a phytochemical occurring in various plants such as cloves, cinnamon, basil, and nutmeg. Pharmacological effects of allylguaiacol include antimicrobial, anti-inflammatory, anticancer, antioxidant, and neuroprotective activity. Although allylguaiacol is considered to have neuroprotective effects, there is no report on its regulatory mechanisms at the molecular level. In the present study, we investigated the mechanisms of allylguaiacol as an antioxidant and neuroprotective agent using hydrogen peroxide (H2O2)-treated HT22 hippocampal cells. Allylguaiacol increased the scavenging activities of free radicals 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), and enhanced the expression of antioxidant enzymes manganese superoxide dismutase (MnSOD) and catalase. In addition, allylguaiacol inhibited H2O2-induced damage of HT22 with increasing production of brain-derived neurotrophic factor (BDNF), phosphorylation of phosphoinositide 3-kinase (PI3K), and cyclic AMP response element-binding protein (CREB). Furthermore, antibody microarray data revealed that phospho-regulation of nuclear factor kappa B (NF-κB) p65 and death domain-associated protein (DAXX) is involved in protection against neuronal cell damage. In a mouse model of short-term memory impairment, allylguaiacol (2.5 or 5mg/kg) significantly ameliorated scopolamine-mediated cognitive impairment in a passive avoidance task. In addition, allylguaiacol significantly increased the expression of TrkA and B in the hippocampus from scopolamine-treated mice. Taken together, our findings suggest that allylguaiacol exerts a neuroprotective effect through the antioxidant activation and protein regulation of NF-κB p65 and DAXX-related signaling. The ameliorating effect of allylguaiacol may be useful for treatment of memory impairment in Alzheimer's and its related diseases.