Selective induction of Rab9-dependent alternative mitophagy using a synthetic derivative of isoquinoline alleviates mitochondrial dysfunction and cognitive deficits in Alzheimer's disease models.

Rationale: Promotion of mitophagy is considered a promising strategy for the treatment of neurodegenerative diseases including Alzheimer's disease (AD). The development of mitophagy-specific inducers with low toxicity and defined molecular mechanisms is essential for the clinical application of mitophagy-based therapy. The aim of this study was to investigate the potential of a novel small-molecule mitophagy inducer, ALT001, as a treatment for AD. Methods: ALT001 was developed through chemical optimization of an isoquinolium scaffold, which was identified from a chemical library screening using a mitophagy reporter system. In vitro and in vivo experiments were conducted to evaluate the potential of ALT001 as a mitophagy-targeting therapeutic agent and to investigate the molecular mechanisms underlying ALT001-induced mitophagy. The therapeutic effect of ALT001 was assessed in SH-SY5Y cells expressing mutant APP and mouse models of AD (5×FAD and PS2APP) by analyzing mitochondrial dysfunction and cognitive defects. Results: ALT001 specifically induces mitophagy both in vitro and in vivo but is nontoxic to mitochondria. Interestingly, we found that ALT001 induces mitophagy through the ULK1-Rab9-dependent alternative mitophagy pathway independent of canonical mitophagy pathway regulators such as ATG7 and PINK1. Importantly, ALT001 reverses mitochondrial dysfunction in SH-SY5Y cells expressing mutant APP in a mitophagy-dependent manner. ALT001 induces alternative mitophagy in mice and restores the decreased mitophagy level in a 5×FAD AD model mouse. In addition, ALT001 reverses mitochondrial dysfunction and cognitive defects in the PS2APP and 5×FAD AD mouse models. AAV-mediated silencing of Rab9 in the hippocampus further confirmed that ALT001 exerts its therapeutic effect through alternative mitophagy. Conclusion: Our results highlight the therapeutic potential of ALT001 for AD via alleviation of mitochondrial dysfunction and indicate the usefulness of the ULK1-Rab9 alternative mitophagy pathway as a therapeutic target.

Oligonol ameliorates liver function and brain function in the 5 × FAD mouse model: transcriptional and cellular analysis.

Alzheimer's disease (AD) is a common neurodegenerative disease worldwide and is accompanied by memory deficits, personality changes, anxiety, depression, and social difficulties. For treatment of AD, many researchers have attempted to find medicinal resources with high effectiveness and without side effects. Oligonol is a low molecular weight polypeptide derived from lychee fruit extract. We investigated the effects of oligonol in 5 × FAD transgenic AD mice, which developed severe amyloid pathology, through behavioral tests (Barnes maze, marble burying, and nestle shredding) and molecular experiments. Oligonol treatment attenuated blood glucose levels and increased the antioxidant response in the livers of 5 × FAD mice. Moreover, the behavioral score data showed improvements in anxiety, depressive behavior, and cognitive impairment following a 2-month course of orally administered oligonol. Oligonol treatment not only altered the circulating levels of cytokines and adipokines in 5 × FAD mice, but also significantly enhanced the mRNA and protein levels of antioxidant enzymes and synaptic plasticity in the brain cortex and hippocampus. Therefore, we highlight the therapeutic potential of oligonol to attenuate neuropsychiatric problems and improve memory deficits in the early stage of AD.

Bifunctional G-Quadruplex Aptamer Targeting Nucleolin and Topoisomerase 1: Antiproliferative Activity and Synergistic Effect of Conjugated Drugs.

As a counterpart to antibody-drug conjugates (ADCs), aptamer-drug conjugates (ApDCs) have been considered a promising strategy for targeted therapy due to the various benefits of aptamers. However, an aptamer merely serves as a targeting ligand in ApDCs, whereas the antibody enables the unexpected therapeutic efficacy of ADCs through antibody-dependent cellular cytotoxicity (ADCC). In this study, we developed a tumor-specific aptamer with an effector function and used it to confirm the feasibility of more potent ApDCs. First, we designed a nucleolin (NCL)-binding G-quadruplex (GQ) library based on the ability of NCL to bind to telomeric sequences. We then identified a bifunctional GQ aptamer (BGA) inhibiting the catalytic activity of topoisomerase 1 (TOP1) by forming an irreversible cleavage complex. Our BGA specifically targeted NCL-positive MCF-7 cells, exhibiting antiproliferative activity, and this suggested that tumor-specific therapeutic aptamers can be developed by using a biased library to screen aptamer candidates for functional targets. Finally, we utilized DM1, which has a synergistic interaction with TOP1 inhibitors, as a conjugated drug. BGA-DM1 exerted an anticancer effect 20-fold stronger than free DM1 and even 10-fold stronger than AS1411 (NCL aptamer)-DM1, highlighting our approach to develop synergistic ApDCs. Therefore, we anticipate that our library might be utilized for the identification of aptamers with effector functions. Furthermore, by employing such aptamers and appropriate drugs, synergistic ApDCs can be developed for targeted cancer therapy in a manner distinct from how ADCs exhibit additional therapeutic efficacy.

Oat Extract Avenanthramide-C Reverses Hippocampal Long-Term Potentiation Decline in Tg2576 Mice.

Memory deterioration in Alzheimer's disease (AD) is thought to be underpinned by aberrant amyloid ß (Aß) accumulation, which contributes to synaptic plasticity impairment. Avenanthramide-C (Avn-C), a polyphenol compound found predominantly in oats, has a range of biological properties. Herein, we performed methanolic extraction of the Avns-rich fraction (Fr. 2) from germinated oats using column chromatography, and examined the effects of Avn-C on synaptic correlates of memory in a mouse model of AD. Avn-C was identified in Fr. 2 based on 1H-NMR analysis. Electrophysiological recordings were performed to examine the effects of Avn-C on the hippocampal long-term potentiation (LTP) in a Tg2576 mouse model of AD. Avn-C from germinated oats restored impaired LTP in Tg2576 mouse hippocampal slices. Furthermore, Avn-C-facilitated LTP was associated with changes in the protein levels of phospho-glycogen synthase kinase-3ß (p-GSK3ß-S9) and cleaved caspase 3, which are involved in Aß-induced synaptic impairment. Our findings suggest that the Avn-C extract from germinated oats may be beneficial for AD-related synaptic plasticity impairment and memory decline.

Chemical Use and Associated Health Concerns in the Semiconductor Manufacturing Industry.

BACKGROUND: Research on the status of many chemicals used in the semiconductor industry is needed. The purpose of this study was to describe the overall status of chemical use in the semiconductor industry in Korea and to examine it from a health perspective. METHODS: Data on the status of chemical use and safety data sheets at 11 of 12 major semiconductor workplaces in Korea were collected. The number of chemical products and chemical constituents, quantities of chemicals, and trade secret ingredients used, as well as the health hazards were examined. RESULTS: On average, 210 chemical products and 135 chemical constituents were used at the surveyed workplaces. Among all chemical products, 33% (range: 16-56%) contained at least one trade secret ingredient. Most of the trade secret ingredients were used in the photolithography process. Several carcinogens, including sulfuric acid, chromic acid, ethylene oxide, crystalline silica, potassium dichromate, and formaldehyde were also used. Only 29% (39 of 135) of the chemical constituents had occupational exposure limits, and more than 60% had no National Fire Protection Association health, safety, and reactivity ratings. Based on the aforementioned results, this study revealed the following. First, many chemical products and constituents are being used in the semiconductor industry and many products contained trade secret ingredients. Second, many products contained significant amounts of carcinogenic, mutagenic, and reproductive toxicant materials. CONCLUSION: We conclude that protecting workers in the semiconductor industry against harm from chemical substances will be difficult, due to widespread use of trade secret ingredients and a lack of hazard information. The findings of the status of chemical use and the health and safety risks in semiconductor industry will contribute to epidemiological studies, safe workplace, and worker health protection.

Avenanthramide-C Restores Impaired Plasticity and Cognition in Alzheimer's Disease Model Mice.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline and dementia with no effective treatment. Here, we investigated a novel compound from oats named avenanthramide-C (Avn-C), on AD-related memory impairment and behavioral deficits in transgenic mouse models. Acute hippocampal slices of wild-type or AD transgenic mice were treated with Avn-C in the presence or absence of oligomeric Aß42. LTP analyses and immunoblotting were performed to assess the effect of Avn-C on Aß-induced memory impairment. To further investigate the effect of Avn-C on impaired memory and Aß pathology, two different AD transgenic mice (Tg2576 and 5XFAD) models were orally treated with either Avn-C or vehicle for 2 weeks. They were then assessed for the effect of the treatment on neuropathologies and behavioral impairments. Avn-C reversed impaired LTP in both ex vivo- and in vivo-treated AD mice hippocampus. Oral administration (6 mg/kg per day) for 2 weeks in AD mice leads to improved recognition and spatial memory, reduced caspase-3 cleavage, reversed neuroinflammation, and to accelerated glycogen synthase kinase-3ß (pS9GSK-3ß) and interleukin (IL-10) levels. Avn-C exerts its beneficial effects by binding to α1A adrenergic receptors to stimulate adenosine monophosphate-activated kinase (AMPK). All of the beneficial effects of Avn-C on LTP retrieval could be blocked by prazosin hydrochloride, a specific inhibitor of α1A adrenergic receptors. Our findings provide evidence, for the first time, that oats' Avn-C reverses the AD-related memory and behavioral impairments, and establish it as a potential candidate for Alzheimer's disease drug development.

Prediction of the skin sensitization potential of didecyldimethylammonium chloride and 3,7-dimethyl-2,6-octadienal and mixtures of these compounds with the excipient ethylene glycol through the human Cell Line Activation Test and the Direct Peptide Reactivity Assay.

In commercial products such as household deodorants or biocides, didecyldimethylammonium chloride (DDAC) often serves as an antimicrobial agent, citral serves as a fragrance agent, and the excipient ethylene glycol (EG) is used to dissolve the active ingredients. The skin sensitization (SS) potentials of each of these substances are still being debated. Moreover, mixtures of DDAC or citral with EG have not been evaluated for SS potency. The in vitro alternative assay called human Cell Line Activation Test (h-CLAT) and Direct Peptide Reactivity Assay (DPRA) served to address these issues. On three independent runs of h-CLAT, DDAC and citral were predicted to be sensitizers while EG was predicted to be a non-sensitizer and also by the DPRA. Mixtures of DDAC or citral with EG at ratios of 7:3 and 1:4 w/v were all positive by the h-CLAT in terms of SS potential but SS potency was mitigated as the proportion of EG increased. Citral and its EG mixtures were all positive but DDAC and its EG mixtures were all negative by the DPRA, indicating that the DPRA method is not suitable for chemicals with pro-hapten characteristics. Since humans can be occupationally or environmentally exposed to mixtures of excipients with active ingredients, the present study may give insights into further investigations of the SS potentials of various chemical mixtures.

Nasal Cavity Administration of Melanin-Concentrating Hormone Improves Memory Impairment in Memory-Impaired and Alzheimer's Disease Mouse Models.

Melanin-concentrating hormone (MCH) is a highly conserved neuropeptide known to exhibit important functions in the brain. Some studies have reported that MCH improves memory by promoting memory retention. However, the precise molecular mechanisms by which MCH enhances memory impairment have yet to be fully elucidated. In this study, MCH was administered to the scopolamine-induced memory-impaired mice via the nasal cavity to examine the acute effects of MCH and Alzheimer's disease (AD) mouse models to evaluate the chronic effects of MCH. MCH improved memory impairment in both models and reduced soluble amyloid beta in the cerebral cortex of APP/PS1 transgenic mice. In vitro assays also showed that MCH inhibits amyloid beta-induced cytotoxicity. Furthermore, MCH increased long-term potentiation (LTP) in the hippocampus of wild-type and 5XFAD AD mouse model. To further elucidate the mechanisms of the chronic effect of MCH, the levels of phosphorylated CREB and GSK3ß, and the expression of BDNF, TrkB and PSD95 were examined in the cerebral cortex and hippocampus. Our findings indicate that MCH might have neuroprotective effects via downstream pathways associated with the enhancement of neuronal synapses and LTP. This suggests a therapeutic potential of MCH for the treatment of neurodegenerative diseases such as AD.

Adiponectin improves long-term potentiation in the 5XFAD mouse brain.

Adiponectin is an adipokine that regulates apoptosis, glucose and lipid metabolism, and insulin sensitivity in metabolic diseases. As recent studies have associated changes in adipokines and other metabolites in the central nervous system with a risk for Alzheimer's disease (AD), we investigated the effects of adiponectin treatment on hippocampal cells in the 5XFAD mouse model of AD and neuronal SH-SY5Y cells under amyloid beta toxicity. Adiponectin treatment reduced levels of cleaved caspase 3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) apoptosis signalling and decreased glycogen synthase kinase 3 beta (GSK3ß) activation. Moreover, adiponectin treatment triggered long-term potentiation in the hippocampi of 5XFAD mice, which was associated with reduced expression of N-methyl-D-aspartate and its receptor as well as surface expression of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor. These findings suggest that adiponectin inhibits neuronal apoptosis and inflammatory mechanisms and promotes hippocampal long-term potentiation. Thus, adiponectin exhibits beneficial effect on hippocampal synaptic plasticity in Alzheimer's disease mouse model.

Conventionally used reference genes are not outstanding for normalization of gene expression in human cancer research.

BACKGROUND: The selection of reference genes is essential for quantifying gene expression. Theoretically they should be expressed stably and not regulated by experimental or pathological conditions. However, identification and validation of reference genes for human cancer research are still being regarded as a critical point, because cancerous tissues often represent genetic instability and heterogeneity. Recent pan-cancer studies have demonstrated the importance of the appropriate selection of reference genes for use as internal controls for the normalization of gene expression; however, no stably expressed, consensus reference genes valid for a range of different human cancers have yet been identified. RESULTS: In the present study, we used large-scale cancer gene expression datasets from The Cancer Genome Atlas (TCGA) database, which contains 10,028 (9,364 cancerous and 664 normal) samples from 32 different cancer types, to confirm that the expression of the most commonly used reference genes is not consistent across a range of cancer types. Furthermore, we identified 38 novel candidate reference genes for the normalization of gene expression, independent of cancer type. These genes were found to be highly expressed and highly connected to relevant gene networks, and to be enriched in transcription-translation regulation processes. The expression stability of the newly identified reference genes across 29 cancerous and matched normal tissues were validated via quantitative reverse transcription PCR (RT-qPCR). CONCLUSIONS: We reveal that most commonly used reference genes in current cancer studies cannot be appropriate to serve as representative control genes for quantifying cancer-related gene expression levels, and propose in this study three potential reference genes (HNRNPL, PCBP1, and RER1) to be the most stably expressed across various cancerous and normal human tissues.

Identification and sequencing of the gene encoding DNA methyltransferase 3 (DNMT3) from sea cucumber, Apostichopus japonicus.

The sea cucumber Apostichopus japonicus is well known as a traditional tonic food and as a commercially important cultured aquatic species. This species produces saponins, and has a high potential to cope with environmental stress, such as aestivation, organ regeneration, and wound healing. Recently, several studies have shown that cellular reprogramming and the physiological responses of the sea cucumber to environmental changes, including aestivation, are potentially mediated by epigenetic DNA methylation. The DNA methyltransferase (DNMT)1 and DNMT3 genes are independent participants in the maintenance and de novo methylation of specific sequences. Sea urchin (Strongylocentrotus purpuratus) and starfish (Asterina pectinifera), which belong to the same phylum as A. japonicus, have both DNMT1 and DNMT3 genes. However, it was previously reported that DNMT1 is present, but DNMT3 is absent, in A. japonicus. In the present study, we sequenced the full-length cDNA of the A. japonicus DNMT3 gene. The newly sequenced DNMT3 gene comprises three major conserved domains (Pro-Trp-Trp-Pro (PWWP), plant homeodomain (PHD), and S-adenosylmethionine-dependent methyltransferase (AdoMet-MTase)), indicating that the DNMT3 possibly has de novo DNA methylation catalytic activity. Gene structure and phylogenetic analysis showed that sea cucumber DNMT3 is evolutionarily conserved in the Echinodermata. Next, we demonstrated the conservation of DNMT3 gene expression in sea cucumber and starfish belong to same phylum, echinoderm. Using reverse transcription-polymerase chain reaction, sea cucumber DNMT3 mRNA was detected in testis tissue, but not in other tissues tested, including the respiratory tree, muscle, tentacle, intestine, and ovary. This is inconsistent with previous reports, which showed the expression of DNMT3 in ovary, but not in testis of the starfish A. pectinifera, indicating the tissue- and species-specific expression of DNMT3 gene. Although further studies are needed to clarify the epigenetic regulatory mechanisms of DNMT3 and its application to the aquaculture industry, our findings may provide insights into the sea cucumber biology.

Peroxidase-Mimicking Nanoassembly Mitigates Lipopolysaccharide-Induced Endotoxemia and Cognitive Damage in the Brain by Impeding Inflammatory Signaling in Macrophages.

Oxidative stress during sepsis pathogenesis remains the most-important factor creating imbalance and dysregulation in immune-cell function, usually observed following initial infection. Hydrogen peroxide (H2O2), a potentially toxic reactive oxygen species (ROS), is excessively produced by pro-inflammatory immune cells during the initial phases of sepsis and plays a dominant role in regulating the pathways associated with systemic inflammatory immune activation. In the present study, we constructed a peroxide scavenger mannosylated polymeric albumin manganese dioxide (mSPAM) nanoassembly to catalyze the decomposition of H2O2 responsible for the hyper-activation of pro-inflammatory immune cells. In a detailed manner, we investigated the role of mSPAM nanoassembly in modulating the expression and secretion of pro-inflammatory markers elevated in bacterial lipopolysaccharide (LPS)-mediated endotoxemia during sepsis. Through a facile one-step solution-phase approach, hydrophilic bovine serum albumin reduced manganese dioxide (BM) nanoparticles were synthesized and subsequently self-assembled with cationic mannosylated disulfide cross-linked polyethylenimine (mSP) to formulate mSPAM nanoassembly. In particular, we observed that the highly stable mSPAM nanoassembly suppressed HIF1α expression by scavenging H2O2 in LPS-induced macrophage cells. Initial investigation revealed that a significant reduction of free radicals by the treatment of mSPAM nanoassembly has reduced the infiltration of neutrophils and other leukocytes in a local endotoxemia animal model. Furthermore, therapeutic studies in a systemic endotoxemia model demonstrated that mSPAM treatment reduced TNF-α and IL-6 inflammatory cytokines in serum, in turn circumventing organ damage done by the inflammatory macrophages. Interestingly, we also observed that the reduction of these inflammatory cytokines by mSPAM nanoassembly further prevented IBA-1 immuno-positive microglial cell activation in the brain and consequently improved the cognitive function of the animals. Altogether, the administration of mSPAM nanoassembly scavenged H2O2 and suppressed HIF1α expression in LPS-stimulated macrophages and thereby inhibited the progression of local and systemic inflammation as well as neuroinflammation in an LPS-induced endotoxemia model. This mSPAM nanoassembly system could serve as a potent anti-inflammatory agent, and we further anticipate its successful application in treating various inflammation-related diseases.

Perioperative Serum Calcium and Phosphorus Levels are Associated with Hospital Costs and Length of Stay after Major Abdominal Surgery.

This study aimed to identify an association between serum calcium (Ca) and phosphate (P) levels, tested during the pre- and postoperative period, with hospital costs and length of hospital stay (LOS) of patients who underwent major abdominal surgery. This retrospective cohort study analyzed the medical records of patients who underwent major abdominal surgery. A total of 3893 patients were included in the analysis, and multivariable linear regression analysis was performed. For a 1 mg/dL increase in preoperative Ca, total hospital costs decreased by 3997.9 dollars (coefficient: -3997.9, 95% confidence interval (CI): -4900.5, -30,953; p-value < 0.01), and for a 1 mg/dL increase in postoperative P, total hospital costs decreased by 702.5 dollars (coefficient: -702.5, 95% CI: -1274.5, -67.3; p-value = 0.03). Furthermore, for a 1 mg/dL increase in preoperative Ca, LOS decreased by 2.9 days (coefficient: -2.9, 95% CI: -3.7, -2.1; p-value < 0.01). For a 1 mg/dL increase in postoperative P, LOS decreased by 3.4 days (coefficient: -3.4, 95% CI: -4.2, -2.6; p-value < 0.01). This study suggested preoperative Ca and postoperative P could be useful indicators for the reduction of hospital costs and decrease in LOS from the perspective of enhanced recovery after surgery.

ß-amyloid inhibits hippocampal LTP through TNFR/IKK/NF-κB pathway.

Objective The suppressive action of the acute application of oligomeric amyloid-ß (Aß) on hippocampal long-term potentiation (LTP) has been reported widely. Many mechanisms have been proposed for Aß inhibited LTP induction. The inflammatory cytokine tumor necrosis factor-α (TNF-α) has also been reported to play a key role in this LTP inhibition through Aß. However, the underlying molecular mechanisms are largely unknown. This study aimed to investigate the link between Aß- and TNF-α-mediated hippocampal LTP inhibition. Methods Acute hippocampal slices of male wildtype or Alzheimer's disease (AD) transgenic mouse models were treated with the inhibitors of either TNF-α, IκB Kinase (IKK) or Nuclear Factor-κB (NF-κB) in the presence or absence of oligomeric Aß42 (500 nM/2 h). The LTP was assessed using field excitatory post synaptic potential recordings (fEPSP), and immunoblotting was used to evaluate the expression of IKK and NF-κB. Results Acute treatment with Aß or TNF-α alone inhibited LTP and increased the phosphorylation of IKK and NF-κB in wild type mouse hippocampal slices. Pretreatment with TNF-α antagonist infliximab rescued the LTP impairment by Aß and also restored the levels of IKK and NF-κB to the control levels. In addition, pretreatment with IKK2 IV or JSH23 also restored the Aß-mediated LTP impairment. Furthermore, AD transgenic mouse hippocampal slices treated with infliximab or inhibitors of IKK or NF-κB showed improved LTP and reversed the activation of IKK and NF-κB. Conclusion In conclusion, our observations suggest that the IKK/NF-κB signaling pathway play an important role in Aß-mediated hippocampal LTP impairment. Aß might modulate IKK/NF-κB activity by binding or activating tumor necrosis factor receptor (TNFR).

Intraoperative Nefopam Reduces Acute Postoperative Pain after Laparoscopic Gastrectomy: a Prospective, Randomized Study.

BACKGROUND: We assessed whether intraoperative nefopam would reduce opioid consumption and relieve postoperative pain in patients undergoing laparoscopic gastrectomy. METHODS: The 60 enrolled patients were randomly assigned to the control (n = 32) or nefopam (n = 28) group. All patients were blinded to their group assignment. We administered 100 ml of normal saline only (control group) or 20 mg of nefopam mixed in 100 ml normal saline (nefopam group) after anesthesia induction and at the end of surgery. The cumulative amount of fentanyl via intravenous patient-controlled analgesia (PCA), incidence of rescue analgesic medication, and numerical rating scale (NRS) for postoperative pain were evaluated along with the total remifentanil consumption. RESULTS: The mean infusion rate of remifentanil was significantly lower in the nefopam group (0.08 ± 0.05 µg/kg/min) than in the control group (0.13 ± 0.06 µg/kg/min) (P < 0.001). Patients in the nefopam group required less fentanyl via intravenous PCA than those in the control group during the first 6 h after surgery (323.8 ± 119.3 µg vs. 421.2 ± 151.6 µg, P = 0.009). Additionally, fewer patients in the nefopam group than in the control group received a rescue analgesic during the initial 6 h postoperatively (78.6 vs. 96.9%, P = 0.028). The NRS measured while patients were in the post-anesthetic care unit was significantly lower in the nefopam group than in the control group (3.8 ± 1.1 vs. 4.8 ± 1.4, P = 0.012). The subsequent NRS obtained after patients had been transferred to the general ward was comparable between the two groups during the following postoperative period. CONCLUSIONS: Intraoperative nefopam decreased postoperative pain and opioid consumption in the acute postoperative period after laparoscopic gastrectomy. Hence, nefopam may be considered as a component of multimodal analgesia after laparoscopic gastrectomy.

The reemergence of long-term potentiation in aged Alzheimer's disease mouse model.

Mouse models of Alzheimer's disease (AD) have been developed to study the pathophysiology of amyloid ß protein (Aß) toxicity, which is thought to cause severe clinical symptoms such as memory impairment in AD patients. However, inconsistencies exist between studies using these animal models, specifically in terms of the effects on synaptic plasticity, a major cellular model of learning and memory. Whereas some studies find impairments in plasticity in these models, others do not. We show that long-term potentiation (LTP), in the CA1 region of hippocampal slices from this mouse, is impared at Tg2576 adult 6-7 months old. However, LTP is inducible again in slices taken from Tg2576 aged 14-19 months old. In the aged Tg2576, we found that the percentage of parvalbumin (PV)-expressing interneurons in hippocampal CA1-3 region is significantly decreased, and LTP inhibition or reversal mediated by NRG1/ErbB signaling, which requires ErbB4 receptors in PV interneurons, is impaired. Inhibition of ErbB receptor kinase in adult Tg2576 restores LTP but impairs depotentiation as shown in aged Tg2576. Our study suggests that hippocampal LTP reemerges in aged Tg2576. However, this reemerged LTP is an insuppressible form due to impaired NRG1/ErbB signaling, possibly through the loss of PV interneurons.

Infliximab ameliorates AD-associated object recognition memory impairment.

Dysfunctions in the perirhinal cortex (PRh) are associated with visual recognition memory deficit, which is frequently detected in the early stage of Alzheimer's disease. Muscarinic acetylcholine receptor-dependent long-term depression (mAChR-LTD) of synaptic transmission is known as a key pathway in eliciting this type of memory, and Tg2576 mice expressing enhanced levels of Aß oligomers are found to have impaired mAChR-LTD in this brain area at as early as 3 months of age. We found that the administration of Aß oligomers in young normal mice also induced visual recognition memory impairment and perturbed mAChR-LTD in mouse PRh slices. In addition, when mice were treated with infliximab, a monoclonal antibody against TNF-α, visual recognition memory impaired by pre-administered Aß oligomers dramatically improved and the detrimental Aß effect on mAChR-LTD was annulled. Taken together, these findings suggest that Aß-induced inflammation is mediated through TNF-α signaling cascades, disturbing synaptic transmission in the PRh, and leading to visual recognition memory deficits.

Intracellular oligomeric amyloid-beta rapidly regulates GluA1 subunit of AMPA receptor in the hippocampus.

The acute neurotoxicity of oligomeric forms of amyloid-ß 1-42 (Aß) is implicated in the pathogenesis of Alzheimer's disease (AD). However, how these oligomers might first impair neuronal function at the onset of pathology is poorly understood. Here we have examined the underlying toxic effects caused by an increase in levels of intracellular Aß, an event that could be important during the early stages of the disease. We show that oligomerised Aß induces a rapid enhancement of AMPA receptor-mediated synaptic transmission (EPSC(A)) when applied intracellularly. This effect is dependent on postsynaptic Ca(2+) and PKA. Knockdown of GluA1, but not GluA2, prevents the effect, as does expression of a S845-phosphomutant of GluA1. Significantly, an inhibitor of Ca(2+)-permeable AMPARs (CP-AMPARs), IEM 1460, reverses the increase in the amplitude of EPSC(A). These results suggest that a primary neuronal response to intracellular Aß oligomers is the rapid synaptic insertion of CP-AMPARs.

Formulation of glutathione responsive anti-proliferative nanoparticles from thiolated Akt1 siRNA and disulfide-crosslinked PEI for efficient anti-cancer gene therapy.

In this study, thiol-modified siRNA (SH-siRNA) was delivered by bioreducible polyethylenimine (ssPEI), to enhance physicochemical properties of polyplexes and function of siRNA through disulfide bonding between SH-siRNA and ssPEI. The ssPEI was utilized to deliver Akt1 SH-siRNA for suppression of Akt1 mRNA and blockage of Akt1 protein translation, resulting in reduced cellular proliferation and the induction of apoptosis. Disulfide bondings between the ssPEI and SH-siRNA through thiol groups in both were confirmed by DTT treatment. Complexation between ssPEI and Akt1SH-siRNA was enhanced and reduced surface charge of ssPEI/Akt1SH-siRNA complexes with smaller average particle sizes even at lower N/P ratios was obtained compared with PEI/Akt1siRNA ones. Cellular uptake of ssPEI/Akt1SH-siRNA complexes in CT-26 mouse colon cancer cells was also enhanced. The ssPEI/Akt1SH-siRNA complexes reduced proliferation and increased apoptosis of mouse colon cancer cells in vitro. In an in vivo mouse tumor model, the complexes reduced tumor proliferation and downregulation of Akt1 compared to controls.

Stepwise, non-adherent differentiation of human pluripotent stem cells to generate basal forebrain cholinergic neurons via hedgehog signaling.

Basal forebrain cholinergic neurons (bfCNs) which provide innervation to the hippocampus and cortex, are required for memory and learning, and are primarily affected in Alzheimer's Disease (AD), resulting in related cognitive decline. Therefore generation of a source of bfCNs from human pluripotent stem cells (hPSCs) is crucial for in vitro disease modeling and development of novel AD therapies. In addition, for the advancement of regenerative approaches there is a requirement for an accurate developmental model to study the neurogenesis and survival of this population. Here we demonstrate the efficient production of bfCNs, using a novel embryoid body (EB) based non-adherent differentiation (NAdD) protocol. We establish a specific basal forebrain neural stem cell (NSC) phenotype via expression of the basal forebrain transcription factors NKX2.1 and LHX8, as well as the general forebrain marker FOXG1. We present evidence that this lineage is achieved via recapitulation of embryonic events, with induction of intrinsic hedgehog signaling, through the use of a 3D non-adherent differentiation system. This is the first example of hPSC-derived basal forebrain-like NSCs, which are scalable via self-renewal in prolonged culture. Furthermore upon terminal differentiation these basal forebrain-like NSCs generate high numbers of cholinergic neurons expressing the specific markers ChAT, VACht and ISL1. These hPSC-derived bfCNs possess characteristics that are crucial in a model to study AD related cholinergic neuronal loss in the basal forebrain. Examples are expression of the therapeutic target p75(NTR), the release of acetylcholine, and demonstration of a mature, and functional electrophysiological profile. In conclusion, this work provides a renewable source of human functional bfCNs applicable for studying AD specifically in the cholinergic system, and also provides a model of the key embryonic events in human bfCN development.