Highly sensitive near-infrared SERS nanoprobes for in vivo imaging using gold-assembled silica nanoparticles with controllable nanogaps.

BACKGROUND: To take advantages, such as multiplex capacity, non-photobleaching property, and high sensitivity, of surface-enhanced Raman scattering (SERS)-based in vivo imaging, development of highly enhanced SERS nanoprobes in near-infrared (NIR) region is needed. A well-controlled morphology and biocompatibility are essential features of NIR SERS nanoprobes. Gold (Au)-assembled nanostructures with controllable nanogaps with highly enhanced SERS signals within multiple hotspots could be a breakthrough. RESULTS: Au-assembled silica (SiO2) nanoparticles (NPs) (SiO2@Au@Au NPs) as NIR SERS nanoprobes are synthesized using the seed-mediated growth method. SiO2@Au@Au NPs using six different sizes of Au NPs (SiO2@Au@Au50-SiO2@Au@Au500) were prepared by controlling the concentration of Au precursor in the growth step. The nanogaps between Au NPs on the SiO2 surface could be controlled from 4.16 to 0.98 nm by adjusting the concentration of Au precursor (hence increasing Au NP sizes), which resulted in the formation of effective SERS hotspots. SiO2@Au@Au500 NPs with a 0.98-nm gap showed a high SERS enhancement factor of approximately 3.8 × 106 under 785-nm photoexcitation. SiO2@Au@Au500 nanoprobes showed detectable in vivo SERS signals at a concentration of 16 µg/mL in animal tissue specimen at a depth of 7 mm. SiO2@Au@Au500 NPs with 14 different Raman label compounds exhibited distinct SERS signals upon subcutaneous injection into nude mice. CONCLUSIONS: SiO2@Au@Au NPs showed high potential for in vivo applications as multiplex nanoprobes with high SERS sensitivity in the NIR region.

Silver-Assembled Silica Nanoparticles in Lateral Flow Immunoassay for Visual Inspection of Prostate-Specific Antigen.

Prostate-specific antigen (PSA) is the best-known biomarker for early diagnosis of prostate cancer. For prostate cancer in particular, the threshold level of PSA <4.0 ng/mL in clinical samples is an important indicator. Quick and easy visual detection of the PSA level greatly helps in early detection and treatment of prostate cancer and reducing mortality. In this study, we developed optimized silica-coated silver-assembled silica nanoparticles (SiO2@Ag@SiO2 NPs) that were applied to a visual lateral flow immunoassay (LFIA) platform for PSA detection. During synthesis, the ratio of silica NPs to silver nitrate changed, and as the synthesized NPs exhibited distinct UV spectra and colors, most optimized SiO2@Ag@SiO2 NPs showed the potential for early prostate cancer diagnosis. The PSA detection limit of our LFIA platform was 1.1 ng/mL. By applying each SiO2@Ag@SiO2 NP to the visual LFIA platform, optimized SiO2@Ag@SiO2 NPs were selected in the test strip, and clinical samples from prostate cancer patients were successfully detected as the boundaries of non-specific binding were clearly seen and the level of PSA was <4 ng/mL, thus providing an avenue for quick prostate cancer diagnosis and early treatment.

Neuroprotective effect of lithium after pilocarpine-induced status epilepticus in mice.

Status epilepticus is the most common serious neurological condition triggered by abnormal electrical activity, leading to severe and widespread cell loss in the brain. Lithium has been one of the main drugs used for the treatment of bipolar disorder for decades, and its anticonvulsant and neuroprotective properties have been described in several neurological disease models. However, the therapeutic mechanisms underlying lithium's actions remain poorly understood. The muscarinic receptor agonist pilocarpine is used to induce status epilepticus, which is followed by hippocampal damage. The present study was designed to investigate the effects of lithium post-treatment on seizure susceptibility and hippocampal neuropathological changes following pilocarpine-induced status epilepticus. Status epilepticus was induced by administration of pilocarpine hydrochloride (320 mg/kg, i.p.) in C57BL/6 mice at 8 weeks of age. Lithium (80 mg/kg, i.p.) was administered 15 minutes after the pilocarpine injection. After the lithium injection, status epilepticus onset time and mortality were recorded. Lithium significantly delayed the onset time of status epilepticus and reduced mortality compared to the vehicle-treated group. Moreover, lithium effectively blocked pilocarpine-induced neuronal death in the hippocampus as estimated by cresyl violet and Fluoro-Jade B staining. However, lithium did not reduce glial activation following pilocarpine-induced status epilepticus. These results suggest that lithium has a neuroprotective effect and would be useful in the treatment of neurological disorders, in particular status epilepticus.

Mucosal and salivary microbiota associated with recurrent aphthous stomatitis.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder of unclear etiopathogenesis. Although recent studies of the oral microbiota by high-throughput sequencing of 16S rRNA genes have suggested that imbalances in the oral microbiota may contribute to the etiopathogenesis of RAS, no specific bacterial species associated with RAS have been identified. The present study aimed to characterize the microbiota in the oral mucosa and saliva of RAS patients in comparison with control subjects at the species level. RESULTS: The bacterial communities of the oral mucosa and saliva from RAS patients with active lesions (RAS, n = 18 for mucosa and n = 8 for saliva) and control subjects (n = 18 for mucosa and n = 7 for saliva) were analyzed by pyrosequencing of the 16S rRNA genes. There were no significant differences in the alpha diversity between the controls and the RAS, but the mucosal microbiota of the RAS patients showed increased inter-subject variability. A comparison of the relative abundance of each taxon revealed decreases in the members of healthy core microbiota but increases of rare species in the mucosal and salivary microbiota of RAS patients. Particularly, decreased Streptococcus salivarius and increased Acinetobacter johnsonii in the mucosa were associated with RAS risk. A dysbiosis index, which was developed using the relative abundance of A. johnsonii and S. salivarius and the regression coefficients, correctly predicted 83 % of the total cases for the absence or presence of RAS. Interestingly, A. johnsonii substantially inhibited the proliferation of gingival epithelial cells and showed greater cytotoxicity against the gingival epithelial cells than S. salivarius. CONCLUSION: RAS is associated with dysbiosis of the mucosal and salivary microbiota, and two species associated with RAS have been identified. This knowledge may provide a diagnostic tool and new targets for therapeutics for RAS.

The neuroprotective mechanism of ampicillin in a mouse model of transient forebrain ischemia.

Ampicillin, a ß-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ischemia, ampicillin (200 mg/kg, intraperitoneally [i.p.]) or penicillin G (6,000 U/kg or 20,000 U/kg, i.p.) was administered daily for 5 days. The pretreatment with ampicillin but not with penicillin G signifi cantly attenuated neuronal damage in the hippocampal CA1 subfield. Mechanistically, the increased activity of matrix metalloproteinases (MMPs) following forebrain ischemia was also attenuated by ampicillin treatment. In addition, the ampicillin treatment reversed increased immunoreactivities to glial fibrillary acidic protein and isolectin B4, markers of astrocytes and microglia, respectively. Furthermore, the ampicillin treatment significantly increased the level of glutamate transporter-1, and dihydrokainic acid (DHK, 10 mg/kg, i.p.), an inhibitor of glutamate transporter-1 (GLT-1), reversed the neuroprotective effect of ampicillin. Taken together, these data indicate that ampicillin provides neuroprotection against ischemia-reperfusion brain injury, possibly through inducing the GLT-1 protein and inhibiting the activity of MMP in the mouse hippocampus.

Neuroprotective effect of caffeic acid phenethyl ester in 3-nitropropionic acid-induced striatal neurotoxicity.

Caffeic acid phenethyl ester (CAPE), derived from honeybee hives, is a bioactive compound with strong antioxidant activity. This study was designed to test the neuroprotective effect of CAPE in 3-nitropropionic acid (3NP)-induced striatal neurotoxicity, a chemical model of Huntington's disease (HD). Initially, to test CAPE's antioxidant activity, a 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) antioxidant assay was employed, and CAPE showed a strong direct radical-scavenging eff ect. In addition, CAPE provided protection from 3NP-induced neuronal cell death in cultured striatal neurons. Based on these observations, the in vivo therapeutic potential of CAPE in 3NP-induced HD was tested. For this purpose, male C57BL/6 mice were repeatedly given 3NP to induce HD-like pathogenesis, and 30 mg/kg of CAPE or vehicle (5% dimethyl sulfoxide and 95% peanut oil) was administered daily. CAPE did not cause changes in body weight, but it reduced mortality by 29%. In addition, compared to the vehicle-treated group, robustly reduced striatal damage was observed in the CAPE-treated animals, and the 3NP-induced behavioral defi cits on the rotarod test were signifi cantly rescued after the CAPE treatment. Furthermore, immunohistochemical data showed that immunoreactivity to glial fibrillary acidic protein (GFAP) and CD45, markers for astrocyte and microglia activation, respectively, were strikingly reduced. Combined, these data unequivocally indicate that CAPE has a strong antioxidant eff ect and can be used as a potential therapeutic agent against HD.

The inhibitory effect of vitexin on the agonist-induced regulation of vascular contractility.

The present study was undertaken to investigate the influence of vitexin on vascular smooth muscle contractility and to determine the mechanism involved. Intact or denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Vitexin more significantly relaxed phorbol ester-induced vascular contraction than thromboxane A2 or fluoride-induced contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, vitexin significantly inhibited phorbol ester-induced increases in pERK1/2 levels. On the other hand, it did not significantly inhibit thromboxane A2-induced increases in pMYPT1 levels suggesting the mechanism involving the primarily inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of vitexin on agonist-induced vascular contraction regardless of endothelial function.

SERS detection of dopamine using metal-chelated Ag nanoshell.

As the concentrations of different neurotransmitters can indicate the presence of certain disorders affecting brain functions, quantitative analyses of neurotransmitters have attracted increasing attention in various fields. Surface-enhanced Raman scattering (SERS) spectroscopy is an outstanding spectroscopic analytical tool that enables detection at the single molecule level with high specificity. As local field enhancement of surface plasmon is effective within nanometers, active interaction between SERS-active noble metals (gold and silver) and analyte molecules enhances the molecular detection capacity of SERS. However, neurotransmitters and noble metal nanoparticles are often not affinitive, because neurotransmitters generally have a hydroxyl group rather than a thiol group. As a result, the interaction between the two typically remains inactive, which makes detection more difficult. To overcome this limitation, in the present work we utilized metal-chelation to attract dopamine, a neurotransmitter molecule, close to the surface of silver nanoparticles. AgNS was capped with poly(vinyl alcohol) (PVA) and sequentially integrated with copper ion to bind dopamine in the form of chelate bonding between dopamine and copper. The PVA linked AgNS and metal ions through a coordinate bond between hydroxyl groups and metal ions. This metal-chelation-functionalized nanoprobe allowed us to stably detect dopamine in aqueous solution at a concentration of less than 10-6 M. Therefore, this method provides a convenient and easy-to-prepare option for the effective detection of dopamine, thus meaning it has the potential to be applied to other neurotransmitters.

A periodontal pathogen Treponema denticola hijacks the Fusobacterium nucleatum-driven host response.

Periodontitis is a polymicrobial disease that arises from the dysbiosis of the plaque biofilm. To study polymicrobial interactions with gingival epithelial cells, the oral commensal Fusobacterium nucleatum and the periodontal pathogen Treponema denticola were chosen due to their opposing effects on the expression of human beta-defensins (HBDs) and interleukin (IL)-8 in gingival epithelial cells. Immortalized gingival epithelial HOK-16B cells were infected with either F. nucleatum or T. denticola alone or together, and the expression of HBDs and IL-8 was investigated. Coinfection with F. nucleatum and T. denticola neutralized the stimulatory and suppressive effects on the expression of HBD-2 and -3, but the suppressive effect of T. denticola on IL-8 expression remained. In CHO/CD14/TLR2 reporter cells, T. denticola attenuated F. nucleatum-induced activation of TLR2, a receptor that mediates HBD induction. Although F. nucleatum facilitated the invasion of T. denticola into host cells, T. denticola interfered with the fusion of internalized F. nucleatum with lysosomes, which may avert TLR9-dependent IL-8 induction. Furthermore, T. denticola suppressed the F. nucleatum-stimulated accumulation of intracellular reactive oxygen species (ROS), a group of essential signaling molecules for the TLR2 and TLR9 pathways. The elimination of ROS using N-acetyl cysteine completely blocked the inductions of HBD-3 and IL-8 and significantly reduced HBD-2 induction by F. nucleatum, confirming the importance of ROS in the host response. In sum, T. denticola incapacitates the F. nucleatum-induced expression of HBDs and IL-8 in gingival epithelial cells by interrupting endo-lysosomal maturation and ROS-dependent TLR activation. These results may provide new insights into polymicrobial interactions in the gingival sulcus.

MSK1 regulates environmental enrichment-induced hippocampal plasticity and cognitive enhancement.

Environmental enrichment (EE) has marked beneficial effects on cognitive capacity. Given the possibility that this form of neuronal plasticity could function via the actuation of the same cellular signaling pathways that underlie learning/memory formation, we examined whether the MAPK cascade effector, mitogen/stress-activated kinase 1 (MSK1), could play a role in this process. MSK1 functions as a key signaling intermediate that couples changes in neuronal activity into inducible gene expression, neuronal plasticity, and learning/memory. Here, we show that MSK1 is expressed in excitatory cell layers of the hippocampus, progenitor cells of the subgranular zone (SGZ), and adult-born immature neurons. MSK1(-/-) mice exhibit reduced spinogenesis and decreased dendritic branching complexity in hippocampal neurons, compared with WT mice. Further, in MSK1(-/-) mice, progenitor cell proliferation within the SGZ was significantly reduced and, correspondingly, the number of immature neurons within the dentate gyrus was significantly reduced. Consistent with prior work, MSK1(-/-) mice displayed deficits in both spatial and recognition memory tasks. Strikingly, cognitive enhancement resulting from a 40-d period of EE was markedly reduced in MSK1(-/-) animals. MSK1(-/-) mice exhibited reduced levels of EE-induced spinogenesis and SGZ progenitor proliferation. Taken together, these data reveal that MSK1 serves as a critical regulator of hippocampal physiology and function and that MSK1 serves as a key conduit by which enriching stimuli augment cellular plasticity and cognition.

Influence of aspirin on pilocarpine-induced epilepsy in mice.

Aspirin (acetylsalicylic acid) is one of the most widely used therapeutic agents based on its pharmacological actions, including anti-inflammatory, analgesic, anti-pyretic, and anti-thrombotic effects. In this study, we investigated the effects of aspirin on seizure susceptibility and hippocampal neuropathology following pilocarpine-induced status epilepticus (SE). SE was induced by pilocarpine hydrochloride (280 mg/kg, i.p.) administration in C57BL/6 mice (aged 8 weeks). Aspirin was administered daily (15 mg/kg or 150 mg/kg, i.p.) for 10 days starting 3 days before SE, continuing until 6 days after SE. After pilocarpine injection, SE onset time and mortality were recorded. Neuronal cell death was examined using cresyl violet and Fluoro-Jade staining, and glial responses were observed 7 days post SE using immunohistochemistry. In the aspirin-treated group, the onset time of SE was significantly shortened and mortality was markedly increased compared to the control group. However, in this study, aspirin treatment did not affect SE-induced neuronal cell death or astroglial and microglial responses in the hippocampus. In conclusion, these results suggest that the safety of aspirin should be reevaluated in some patients, especially with neurological disorders such as temporal lobe epilepsy.

Schisandrol A and gomisin N from Schisandra chinensis extract improve hypogonadism via anti-oxidative stress in TM3 Leydig cells.

BACKGROUND/OBJECTIVES: Male hypogonadism is a condition where the body does not produce enough testosterone and significantly impacts health. Age, obesity, genetics, and oxidative stress are some physiological factors that may contribute to testosterone deficiency. Previous studies have shown many pharmacological benefits of Schisandra chinensis (S. chinensis) Baillon as an anti-inflammatory and antioxidant. However, the molecular mechanism of attenuating hypogonadism is yet to be well established. This research was undertaken to study the effects of S. chinensis extract (SCE) on testosterone deficiency. MATERIALS/METHODS: S. chinensis fruit was pulverized and extracted using 60% aqueous ethanol. HPLC analysis was performed to analyze and quantify the lignans of the SCE. RESULTS: The 2,2-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging assays confirmed that the SCE and its major lignans (schisandrol A and gomisin N) inhibit oxidative stress. Effects of SCE analysis on the testosterone level under oxidative stress conditions revealed that both schisandrol A and gomisin N were able to recover the lowered testosterone levels. Through mRNA expression of TM3 Leydig cell, we observed that the SCE lignans were able to induce the enzymes involved in testosterone biosynthesis-related genes such as 3ß-HSD4 (P < 0.01 for SCE, and P < 0.001 for schisandrol A and gomisin N), 17ß-HSD3 (P < 0.001 for SCE, schisandrol A and gomisin N), and 17, 20-desmolase (P < 0.01 for schisandrol A, and P < 0.001 for SCE and gomisin N). CONCLUSIONS: These results support that SCE and its active components could be potential therapeutic agents for regulating and increasing testosterone production.

In vivo surface-enhanced Raman scattering nanosensor for the real-time monitoring of multiple stress signalling molecules in plants.

When under stress, plants release molecules to activate their defense system. Detecting these stress-related molecules offers the possibility to address stress conditions and prevent the development of diseases. However, detecting endogenous signalling molecules in living plants remains challenging due to low concentrations of these analytes and interference with other compounds; additionally, many methods currently used are invasive and labour-intensive. Here we show a non-destructive surface-enhanced Raman scattering (SERS)-based nanoprobe for the real-time detection of multiple stress-related endogenous molecules in living plants. The nanoprobe, which is placed in the intercellular space, is optically active in the near-infrared region (785 nm) to avoid interferences from plant autofluorescence. It consists of a Si nanosphere surrounded by a corrugated Ag shell modified by a water-soluble cationic polymer poly(diallyldimethylammonium chloride), which can interact with multiple plant signalling molecules. We measure a SERS enhancement factor of 2.9 × 107 and a signal-to-noise ratio of up to 64 with an acquisition time of ~100 ms. To show quantitative multiplex detection, we adopted a binding model to interpret the SERS intensities of two different analytes bound to the SERS hot spot of the nanoprobe. Under either abiotic or biotic stress, our optical nanosensors can successfully monitor salicylic acid, extracellular adenosine triphosphate, cruciferous phytoalexin and glutathione in Nasturtium officinale, Triticum aestivum L. and Hordeum vulgare L.-all stress-related molecules indicating the possible onset of a plant disease. We believe that plasmonic nanosensor platforms can enable the early diagnosis of stress, contributing to a timely disease management of plants.

Mitogen- and stress-activated kinases regulate progenitor cell proliferation and neuron development in the adult dentate gyrus.

The neurogenic niche within the subgranular zone (SGZ) of the dentate gyrus is a source of new neurons throughout life. Interestingly, SGZ proliferative capacity is regulated by both physiological and pathophysiological conditions. One outstanding question involves the molecular mechanisms that regulate both basal and inducible adult neurogenesis. Here, we examined the role of the MAPK-regulated kinases, mitogen- and stress-activated kinase (MSK)1 and MSK2. as regulators of dentate gyrus SGZ progenitor cell proliferation and neurogenesis. Under basal conditions, MSK1/2 null mice exhibited significantly reduced progenitor cell proliferation capacity and a corollary reduction in the number of doublecortin (DCX)-positive immature neurons. Strikingly, seizure-induced progenitor proliferation was totally blocked in MSK1/2 null mice. This blunting of cell proliferation in MSK1/2 null mice was partially reversed by forskolin infusion, indicating that the inducible proliferative capacity of the progenitor cell population was intact. Furthermore, in MSK1/2 null mice, DCX-positive immature neurons exhibited reduced neurite arborization. Together, these data reveal a critical role for MSK1/2 as regulators of both basal and activity-dependent progenitor cell proliferation and morphological maturation in the SGZ.

The Patient-Derived Cancer Organoids: Promises and Challenges as Platforms for Cancer Discovery.

The cancer burden is rapidly increasing in most countries, and thus, new anticancer drugs for effective cancer therapy must be developed. Cancer model systems that recapitulate the biological processes of human cancers are one of the cores of the drug development process. PDCO has emerged as a unique model that preserves the genetic, physiological, and histologic characteristics of original cancer, including inter- and intratumoral heterogeneities. Due to these advantages, the PCDO model is increasingly investigated for anticancer drug screening and efficacy testing, preclinical patient stratification, and precision medicine for selecting the most effective anticancer therapy for patients. Here, we review the prospects and limitations of PDCO compared to the conventional cancer models. With advances in culture success rates, co-culture systems with the tumor microenvironment, organoid-on-a-chip technology, and automation technology, PDCO will become the most promising model to develop anticancer drugs and precision medicine.

Segregation of expression of mPeriod gene homologs in neurons and glia: possible divergent roles of mPeriod1 and mPeriod2 in the brain.

The suprachiasmatic nuclei (SCN) of the mammalian hypothalamus function as the master circadian clock, coordinating the timing of diverse cell populations and organ systems. Dysregulation of clock timing is linked to a broad range of human conditions, including obesity, cardiovascular disease and a wide spectrum of neurological disorders. Aberrant regulation of expression of the PERIOD genes has been associated with improper cell division and human cancers, while the autosomal dominant disorder familial advanced sleep phase syndrome has been mapped to a single missense mutation within the critical clock gene hPERIOD2. An essential tool to begin to dissect the inherent molecular timing process is the clock gene reporter. Here, we functionally characterize two new mouse transgenic clock reporters, mPeriod1-Venus and mPeriod2-DsRED. Venus and DsRED are fluorescent proteins that can be used to monitor transcription in individual cells in real-time. Imaging of the SCN revealed oscillations, as well as light inducibility, in Venus and DsRED expression. Rhythmic Venus and DsRED expression was observed in distinct SCN cell populations, suggesting the existence of discrete cellular SCN clocks. Outside of the SCN, mPeriod1-Venus expression was broadly expressed in neuronal and non-neuronal populations. Conversely, mPeriod2-DsRED was expressed in glial populations and progenitor cells of the dentate gyrus; limited expression was detected in neurons. This distinct expression pattern of the two reporters reveals that the central nervous system possesses mechanistically distinct subpopulations of neuronal and non-neuronal cellular clocks. These novel mouse models will facilitate our understanding of clock timing and its role in human diseases.

Lateral Flow Immunoassay with Quantum-Dot-Embedded Silica Nanoparticles for Prostate-Specific Antigen Detection.

Prostate cancer can be detected early by testing the presence of prostate-specific antigen (PSA) in the blood. Lateral flow immunoassay (LFIA) has been used because it is cost effective and easy to use and also has a rapid sample-to-answer process. Quantum dots (QDs) with very bright fluorescence have been previously used to improve the detection sensitivity of LFIAs. In the current study, a highly sensitive LFIA kit was devised using QD-embedded silica nanoparticles. In the present study, only a smartphone and a computer software program, ImageJ, were used, because the developed system had high sensitivity by using very bright nanoprobes. The limit of PSA detection of the developed LFIA system was 0.138 ng/mL. The area under the curve of this system was calculated as 0.852. The system did not show any false-negative result when 47 human serum samples were analyzed; it only detected PSA and did not detect alpha-fetoprotein and newborn calf serum in the samples. Additionally, fluorescence was maintained on the strip for 10 d after the test. With its high sensitivity and convenience, the devised LFIA kit can be used for the diagnosis of prostate cancer.

Clinical outcomes of submucosal colorectal cancer diagnosed after endoscopic resection: a focus on the need for surgery.

BACKGROUND/AIMS: We aimed to investigate the proportion of and risk factors for residual cancer and/or lymph node metastasis after surgery was performed because of high-risk pathological features in endoscopic resection specimen of suspected superficial submucosal colorectal cancer (SSMC). METHODS: We reviewed medical records of 497 patients (58.8 ± 9.8 years, 331 males) undergoing endoscopic resection of suspected SSMC. High-risk pathological features included: deep submucosal cancer invasion ≥ 1,000 µm; positive lymphovascular and/or perineural invasion; poorly differentiated adenocarcinoma; and positive resection margin. We investigated the occurrence of additional surgery and residual cancer and/or lymph node involvement in the surgical specimen. RESULTS: En bloc resection was performed in 447 patients (89.9%). High-risk pathological features were detected in 372 patients (74.8%). Additional surgery was performed in 336 of 372 patients with high-risk pathological features. Of these, 47 surgical specimens (14.0%) showed residual cancer and/or lymph node metastasis. Piecemeal resection was more common in those with residual cancer and/or lymph node involvement than those without (9/47 [19.1%] vs. 24/289 [8.3%], P= 0.032). Positive resection margin was also significantly associated with positive residual cancer and/or lymph node involvement. As the number of high-risk pathological features increased, the risk of regional lymph node metastasis increased proportionally (P= 0.002). CONCLUSIONS: High-risk pathological features were frequently detected after endoscopic resection of suspected SSMC while residual cancer and/or lymph node metastasis were not commonly present in the additional surgical specimen. Further optimized strategy for proper endoscopic management of suspected SSMC is necessary.

The CREB/CRE transcriptional pathway: protection against oxidative stress-mediated neuronal cell death.

Formation of reactive oxygen and nitrogen species is a precipitating event in an array of neuropathological conditions. In response to excessive reactive oxygen species (ROS) levels, transcriptionally dependent mechanisms drive the up-regulation of ROS scavenging proteins which, in turn, limit the extent of brain damage. Here, we employed a transgenic approach in which cAMP-response element binding protein (CREB)-mediated transcription is repressed (via A-CREB) to examine the contribution of the CREB/cAMP response element pathway to neuroprotection and its potential role in limiting ROS toxicity. Using the pilocarpine-evoked repetitive seizure model, we detected a marked enhancement of cell death in A-CREB transgenic mice. Paralleling this, there was a dramatic increase in tyrosine nitration (a marker of reactive species formation) in A-CREB transgenic mice. In addition, inducible expression of peroxisome proliferator-activated receptor gamma coactivator-1alpha was diminished in A-CREB transgenic mice, as was activity of complex I of the mitochondrial electron transport chain. Finally, the neuroprotective effect of brain-derived neurotrophic factor (BDNF) against ROS-mediated cell death was abrogated by disruption of CREB-mediated transcription. Together, these data both extend our understanding of CREB functionality and provide in vivo validation for a model in which CREB functions as a pivotal upstream integrator of neuroprotective signaling against ROS-mediated cell death.

CREB is a key regulator of striatal vulnerability in chemical and genetic models of Huntington's disease.

Evidence of dysregulation of the CREB/CRE transcriptional pathway in animal models of Huntington's disease (HD) suggests that strategies designed to augment CRE-mediated transcription may be of therapeutic value. Here, we investigated the consequences of CREB activation and repression in chemical and transgenic mouse models of HD. In the 3-nitropropionic acid (3-NP) model, CREB phospho-activation in the striatum was potently repressed within the neurotoxic "core" region prior to cell death. Conversely, marked expression of phospho-CREB, as well the CREB-regulated cytoprotective gene Bcl-2, was detected in the "penumbral" region. To examine potential contributory roles for the CREB/CRE transcriptional pathway in striatal degeneration, we used both CREB loss- (A-CREB) and gain- (VP16-CREB) of-function transgenic mouse strains. 3-NP-induced striatal lesion size and motor dysfunction were significantly increased in A-CREB mice compared to controls. Conversely, striatal damage and motor deficits were diminished in VP16-CREB mice. Furthermore, transgenic A-CREB significantly accelerated motor impairment in the YAC128 mouse model of HD. Together, these results indicate that CREB functionality is lost during the early stages of striatal cell stress and that the repression of CREB-mediated transcription contributes to the pathogenic process.