Memory dysfunction and anxiety-like behavior in a mouse model of chronic sleep disorders.

Sleep disturbances can contribute to cognitive decline and neuropsychiatric disorders. However, the underlying mechanisms of these processes are poorly understood. The present study evaluated the effects of a chronic sleep disorder (CSD) on long-term memory formation and anxiety-like behavior in our originally established mouse model of psychophysiological stress-induced CSD characterized by disrupted circadian rhythms of wheel-running activity and sleep-wake cycles. Model mice are continuously exposed to mild stress imposed by perpetually staying on a running-wheel to avoid water. The findings of novel object recognition (NORT) and open field (OFT) tests showed that CSD impaired recognition memory and elicited anxiety-like behavior, respectively. These results suggested that the CSD impaired cognitive function and emotional status. Thus, this CSD model could be useful for studying the underlying mechanisms of neurobehavioral difficulties caused by sleep disorders. We then examined the hippocampal mRNA expression of genes associated with learning and memory, and anxiety and depression. The CSD increased the mRNA expression of Crhr1, Ngf and Phlpp1, and suppressed that of Ace, Egr2 and Slc6a4. Based on the functions of these genes, we inferred that the increase in Crhr1 mRNA was associated with the pathogenesis of psychiatric conditions, whereas mRNA levels of the other five genes were directed towards symptom relief. Upregulating hippocampal Crhr1 expression might contribute in part to the activation of corticotropin-releasing hormone (CRH)-CRH receptor1 signaling that mediates CSD-evoked mental disorders.

Involvement of the luteinizing hormone surge in the regulation of ovary and oviduct clock gene expression in mice.

Circadian dysfunction perturbs the female reproductive cycle. In particular, mice lacking the clock gene Bmal1 show severe infertility, implying that BMAL1 plays roles in ovulation and luteinization. Here, we examined temporal changes in clock gene expression in the ovary and oviduct before and during gonadotropin-induced follicular growth, ovulation, and luteinization in sexually immature mice. While the oviduct did not show a drastic change in clock gene expression, Bmal1 expression in the ovary was higher than that in control mice during the period from 4 to 16 hr after human chorionic gonadotropin (hCG) administration. Bmal1 expression reached a maximum at 16 hr after hCG administration, when follicle luteinization occurred. In an interesting manner, administration of hCG to ex vivo-cultured oviduct triggered a shorter circadian period and inevitably resulted in phase advance. Together, our present data suggest that LH surge induces continuous expression of BMAL1 in the mouse ovary and modulates circadian phase in the mouse oviduct.

Novel and Stable Dual-Color IL-6 and IL-10 Reporters Derived from RAW 264.7 for Anti-Inflammation Screening of Natural Products.

Our previous study suggested that the interleukin (IL)-6 and IL-10 could serve as good biomarkers for chronic inflammatory disease. We previously established an IL-6 and IL-10 reporters assay that could examine reporter activity along with the reference gene in LPS-induced RAW 264.7 cells. In this study, we described new and stable RAW 264.7 derived dual-color IL-6/gapdh and IL-10/gapdh reporters. This assay allowed us to easily determine relative IL-6 and IL-10 levels with 96-well plate within one step. We evaluated the relative IL-6 and IL-10 levels in the LPS-induced stable cells testing 52 natural products by real-time bioluminescence monitoring and time-point determination using a microplate luminometer. The relative IL-6 and IL-6/IL-10 values decreased by the crude ethanol extracts from nutmeg and by 1'S-1'-acetoxychavicol from greater galangal using real-time bioluminescence monitoring. At the same time, the relative IL-10 was induced. The relative IL-6 and IL-6/IL-10 decreased by crude ethanol extracts from nutmeg and 1'S-1'-acetoxychavicol acetate at 6 h. Only crude ethanol extract from nutmeg induced IL-10 at 6 h. We suggested that the use of these stable cells by real-time monitoring could serve as a screening assay for anti-inflammatory activity and may be used to discover new drugs against chronic inflammatory disease.

Real-time monitoring of IL-6 and IL-10 reporter expression for anti-inflammation activity in live RAW 264.7 cells.

In previous study, we suggested that the interleukin (IL)-6 and IL-10 could serve as a good biomarker for anti-inflammation that related to chronic inflammatory disease. Recently, we are finding new anti-inflammation compounds from natural products by screening of IL-6 and IL-10 levels. Although, we could measure IL-6 and IL-10 levels by several methods. However, all methods could not measure continuous kinetic of IL-6 and IL-10 levels. Most methods have multiple steps and take a long time. Therefore, there is no a suitable method for screening. To this end, we established IL-6 and IL-10 promoter assay which can monitor with reference gene as Glyceraldehyde 3-phosphate dehydrogenase (gapdh) promoter in living single cell. It could determine IL-6 and IL-10 levels continuously in real-time within two steps. We evaluated IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells with well-known anti-inflammatory compounds such as quercetin, xanthones, ß-D-glucan and dexamethasone. As the results, the expression of IL-6 and IL-10 reporters were strongly induced by LPS. The expression of IL-6 reporter was inhibited by all anti-inflammation compounds in LPS-induced RAW 264.7 cells. The expression of IL-10 reporter was inhibited by quercetin, xanthones and dexamethasone in LPS-induced RAW 264.7 cells. While, expression of IL-10 reporter was induced by ß-D-glucan. These results indicated that this assay could use for determination of IL-6 and IL-10 reporter expression in LPS-induced RAW 264.7 cells for anti-inflammation activity. Moreover, the results showed that natural compounds have an effect on the time course of IL-6 and IL-10 expressions. Therefore, real-time monitoring has a merit for natural compounds screening. We suggested that this assay could serve as a compound screening assay for anti-inflammation activity.

Disruption of behavioral circadian rhythms induced by psychophysiological stress affects plasma free amino acid profiles without affecting peripheral clock gene expression in mice.

Disordered circadian rhythms are associated with various psychiatric conditions and metabolic diseases. We recently established a mouse model of a psychophysiological stress-induced chronic sleep disorder (CSD) characterized by reduced amplitude of circadian wheel-running activity and sleep-wake cycles, sleep fragmentation and hyperphagia. Here, we evaluate day-night fluctuations in plasma concentrations of free amino acids (FAA), appetite hormones and prolactin as well as the hepatic expression of circadian clock-related genes in mice with CSD (CSD mice). Nocturnal increases in wheel-running activity and circadian rhythms of plasma prolactin concentrations were significantly disrupted in CSD mice. Hyperphagia with a decreased leptin/ghrelin ratio was found in CSD mice. Day-night fluctuations in plasma FAA contents were severely disrupted without affecting total FAA levels in CSD mice. Nocturnal increases in branched-chain amino acids such as Ile, Leu, and Val were further augmented in CSD mice, while daytime increases in Gly, Ala, Ser, Thr, Lys, Arg, His, Tyr, Met, Cys, Glu, and Asn were significantly attenuated. Importantly, the circadian expression of hepatic clock genes was completely unaffected in CSD mice. These findings suggest that circadian clock gene expression does not always reflect disordered behavior and sleep rhythms and that plasma FFA profiles could serve as a potential biomarker of circadian rhythm disorders.

Harmine lengthens circadian period of the mammalian molecular clock in the suprachiasmatic nucleus.

The circadian clock is a cell-autonomous endogenous system that generates circadian rhythms in the behavior and physiology of most organisms. We previously reported that the harmala alkaloid, harmine, lengthens the circadian period of Bmal1 transcription in NIH 3T3 fibroblasts. Clock protein dynamics were examined using real-time reporter assays of PER2::LUC to determine the effects of harmine on the central clock in the suprachiasmatic nucleus (SCN). Harmine significantly lengthened the period of PER2::LUC expression in embryonic fibroblasts, in neuronal cells differentiated from neuronal progenitor cells and in SCN slices obtained from PER2::LUC mice. Although harmine did not induce the transient mRNA expression of clock genes such as Per1, Per2 and Bmal1 in embryonic fibroblasts, it significantly extended the half-life of PER2::LUC protein in neuronal cells and SCN slices. Harmine might lengthen the circadian period of the molecular clock by increasing PER2 protein stability in the SCN.

Supplementation with Eurycoma longifolia Extract Modulates Diurnal Body Temperature Fluctuation and Sleep Rhythm in Mice.

Eurycoma longifolia (Tongkat Ali; TA) is a traditional medicinal herb, commonly known as Malaysian ginseng. The root tea has been traditionally applied to treat fevers, aches, sexual dysfunction and other ailments. We evaluated the effects of TA extract supplementation on diurnal core body temperature (BT) and sleep architecture in model mice. Dietary supplementation with TA extract for 4 wk resulted in significantly and moderately reduced BT during the rest and active phases, respectively. A high dose delayed the onset of BT elevation at the start of the active phase, indicating that the effect was dose-dependent. Electroencephalography findings revealed that dietary supplementation with TA extract changed sleep rhythms and delta power during the inactive phase of NREM sleep, indicating improved sleep quality. Our findings suggested that dietary TA extract could be a promising natural aid that alleviates sleep problems via thermoregulation.

Anti-Inflammatory Effects of Heliangin from Jerusalem Artichoke (Helianthus tuberosus) Leaves Might Prevent Atherosclerosis.

Atherosclerosis is considered the major cause of cardiovascular and cerebrovascular diseases, which are the leading causes of death worldwide. Excessive nitric oxide production and inflammation result in dysfunctional vascular endothelial cells, which are critically involved in the initiation and progression of atherosclerosis. The present study aimed to identify a bioactive compound from Jerusalem artichoke leaves with anti-inflammatory activity that might prevent atherosclerosis. We isolated bioactive heliangin that inhibited NO production in LPS-induced macrophage-like RAW 264.7 cells. Heliangin suppressed ICAM-1, VCAM-1, E-selectin, and MCP-1 expression, as well as NF-κB and IκBα phosphorylation, in vascular endothelial cells stimulated with TNF-α. These results suggested that heliangin suppresses inflammation by inhibiting excessive NO production in macrophages and the expression of the factors leading to the development of atherosclerosis via the NF-κB signaling pathway in vascular endothelial cells. Therefore, heliangin in Jerusalem artichoke leaves could function in the prevention of atherosclerosis that is associated with heart attacks and strokes.

Polymer-based chemical-nose systems for optical-pattern recognition of gut microbiota.

Gut-microbiota analysis has been recognized as crucial in health management and disease treatment. Metagenomics, a current standard examination method for the gut microbiome, is effective but requires both expertise and significant amounts of general resources. Here, we show highly accessible sensing systems based on the so-called chemical-nose strategy to transduce the characteristics of microbiota into fluorescence patterns. The fluorescence patterns, generated by twelve block copolymers with aggregation-induced emission (AIE) units, were analyzed using pattern-recognition algorithms, which identified 16 intestinal bacterial strains in a way that correlates with their genome-based taxonomic classification. Importantly, the chemical noses classified artificial models of obesity-associated gut microbiota, and further succeeded in detecting sleep disorder in mice through comparative analysis of normal and abnormal mouse gut microbiota. Our techniques thus allow analyzing complex bacterial samples far more quickly, simply, and inexpensively than common metagenome-based methods, which offers a powerful and complementary tool for the practical analysis of the gut microbiome.

Hydroxy-ß-sanshool isolated from Zanthoxylum piperitum (Japanese pepper) shortens the period of the circadian clock.

We showed that an ethanol extract from Zanthoxylum piperitum can shorten the circadian rhythm at the cellular level and that this activity was due to hydroxy-ß-sanshool, a secondary metabolite in this plant. An ethanol extract of Z. piperitum was repeatedly fractionated using solid phase extraction and reverse-phase HPLC, then the circadian rhythms of cells to which the fractions were loaded were monitored using real-time reporter gene assays. We purified one HPLC peak and identified it as hydroxy-ß-sanshool using liquid chromatography (LC)-precision-mass spectrometry (MS). This compound shortened the period of Bmal1 and Per2 at the cellular level. Incubation cells for 24 h with hydroxy-ß-sanshool resulted in upregulated Per2 promoter activity. Hydroxy-ß-sanshool also dose-dependently upregulated expression of the clock genes Bmal1, Per1, Per2 and Cry1 and the clock-controlled oxidative stress responsive genes Gpx1and Sod2.

Conserved amino acid residues in C-terminus of PERIOD 2 are involved in interaction with CRYPTOCHROME 1.

We investigated the amino acid sequences of rat PERIOD2 (rPER2) that are required for interaction with CRYPTOCHROME1 (CRY1) to understand the molecular mechanism of the circadian clock. Co-immunoprecipitation assays using various C-terminal fragments of rPER2 with internal deletions revealed that amino acid residues 1179-1198 are necessary for interaction with CRY1. To identify precisely which amino acid residues are responsible for the interaction, we substituted alanine for residues conserved among PER isoforms and species. We found that more than three mutations of conserved PER2 residues impaired not only binding to CRY1 but also subsequent nuclear translocation, although mutations of non-conserved residues did not affect interaction with CRY1. Thus, the conserved amino acid residues of 1179-1198 in PER2 are apparently responsible for binding to CRY1.

Circadian Clock genes Per2 and clock regulate steroid production, cell proliferation, and luteinizing hormone receptor transcription in ovarian granulosa cells.

Circadian Clock genes are associated with the estrous cycle in female animals. Treatment with Per2 and Clock siRNAs decreased the number of granulosa cells and LHr expression in follicle-stimulating hormone FSH-treated granulosa cells. Per2 siRNA treatment did not stimulate the production of estradiol and expression of P450arom, whereas Clock siRNA treatment inhibited the production of estradiol and expression of P450arom mRNA. Per2 and Clock siRNA treatment increased and unchanged, respectively, progesterone production in FSH-treated granulosa cells. Similarly, expression of StAR mRNA was increased by Per2 siRNA and unchanged by Clock siRNA. Our data provide a new insight that Per2 and Clock have different action on ovarian granulosa cell functions.

Tumor growth suppression in vivo by overexpression of the circadian component, PER2.

Some reports have indicated that the core clock gene, Per2 regulates the cell cycle, immune system and neural functions. To understand the effects of PER2 on tumor growth in vivo, stable transformants of murine sarcoma 180 (S-180) cell lines expressing different levels of PER2 were established. The growth of stable PER2 transformants in vivo was significantly and dose-dependently suppressed according to the amount of PER2 expressed, indicating that PER2 plays a role in the growth suppression of sarcoma cells. The anchorage-dependent and -independent growth in vitro and expression of the clock controlled cell-cycle related genes, wee1, myc, and VEGF were not altered in stable PER2 transformants. In contrast, susceptibility to murine natural killer (NK) cell cytolytic activity was enhanced in PER2 transformants. Furthermore, PER2 transformants suppressed cell motility and reduced fibronectin expression, but the expression of integrin receptors was not affected. These results suggest that sarcoma cells overexpressing PER2 suppress tumors in vivo by changing the nature of tumor cell adhesion.

Molecular characterization of Mybbp1a as a co-repressor on the Period2 promoter.

The circadian clock comprises transcriptional feedback loops of clock genes. Cryptochromes are essential components of the negative feedback loop in mammals as they inhibit CLOCK-BMAL1-mediated transcription. We purified mouse CRY1 (mCRY1) protein complexes from Sarcoma 180 cells to determine their roles in circadian gene expression and discovered that Myb-binding protein 1a (Mybbp1a) interacts with mCRY1. Mybbp1a regulates various transcription factors, but its role in circadian gene expression is unknown. We found that Mybbp1a functions as a co-repressor of Per2 expression and repressed Per2 promoter activity in reporter assays. Chromatin immunoprecipitation (ChIP) assays revealed endogenous Mybbp1a binding to the Per2 promoter that temporally matched that of mCRY1. Furthermore, Mybbp1a binding to the Per2 promoter correlated with the start of the down-regulation of Per2 expression and with the dimethylation of histone H3 Lys9, to which it could also bind. These findings suggest that Mybbp1a and mCRY1 can form complexes on the Per2 promoter that function as negative regulators of Per2 expression.

Purified Gymnemic Acids from Gymnema inodorum Tea Inhibit 3T3-L1 Cell Differentiation into Adipocytes.

Gymnema inodorum (GI) is an indigenous medicinal plant and functional food in Thailand that has recently helped to reduce plasma glucose levels in healthy humans. It is renowned for the medicinal properties of gymnemic acid and its ability to suppress glucose absorption. However, the effects of gymnemic acids on adipogenesis that contribute to the accumulation of adipose tissues associated with obesity remain unknown. The present study aimed to determine the effects of gymnemic acids derived from GI tea on adipogenesis. We purified and identified GiA-7 and stephanosides C and B from GI tea that inhibited adipocyte differentiation in 3T3-L1 cells. These compounds also suppressed the expression of peroxisome proliferator-activated receptor gamma (Pparγ)-dependent genes, indicating that they inhibit lipid accumulation and the early stage of 3T3-L1 preadipocyte differentiation. Only GiA-7 induced the expression of uncoupling protein 1 (Ucp1) and pparγ coactivator 1 alpha (Pgc1α), suggesting that GiA-7 induces mitochondrial activity and beige-like adipocytes. This is the first finding of stephanosides C and B in Gymnema inodorum. Our results suggested that GiA-7 and stephanosides C and B from GI tea could help to prevent obesity.

PERIOD2 is a circadian negative regulator of PAI-1 gene expression in mice.

An increased level of obesity-induced plasma plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular disease. To determine whether the circadian clock component PERIOD2 (PER2) is involved in the regulation of PAI-1 gene expression, we performed transient transfection assays in vitro, and generated transgenic (Tg) mice overexpressing PER2. We then compared PAI-1 expression in Tg and wild-type (WT) mice with or without obesity induced by a high-fat/high-sucrose diet. PER2 suppressed CLOCK:BMAL1- and CLOCK:BMAL2-dependent transactivation of the PAI-1 promoter in vitro. Furthermore, nuclear translocation is dispensable for PER2 to suppress CLOCK:BMAL1-dependent transactivation of the PAI-1 promoter, because functional loss of the nuclear localization domain did not affect either the interaction with BMAL1 or the suppressive role of PER2. The diurnal expression of clock and clock-controlled genes was disrupted in a gene-specific manner, whereas that of PAI-1 mRNA was significantly damped in the hearts of PER2 Tg mice fed with a normal diet. Obesity-induced plasma PAI-1 increase was significantly suppressed in Tg mice in accordance with cardiac PAI-1 mRNA levels, whereas body weight gain and changes in metabolic parameters were identical between WT and Tg mice. Endogenous PAI-1 gene expression induced by transforming growth factor-beta1 was significantly attenuated in embryonic fibroblasts derived from Tg mice compared with those from WT mice. Our results demonstrated that PER2 represses PAI-1 gene transcription in a BMAL1/2-dependent manner. The present findings also suggest that PER2 attenuates obesity-induced hypofibrinolysis by downregulating PAI-1 expression independently of metabolic disorders.

Dietary Heat-Killed Lactobacillus brevis SBC8803 Attenuates Chronic Sleep Disorders Induced by Psychophysiological Stress in Mice.

We previously reported that dietary heat-killed Lactobacillus brevis SBC8803 affects sleep in mice and humans. The present study examined whether SBC8803 improves psychophysiological stress-induced chronic sleep disorders (CSD) using a mouse model characterized by disrupted circadian rhythms of wheel-running activity and sleep-wake cycles. Mice were fed with a diet supplemented with 0.5% heat-killed SBC8803 for 6 wk and imposed stress-induced CSD for last 2 wk. Dietary SBC8803 suppressed the reduction in wheel-running activity induced by CSD. Electroencephalography (EEG) revealed that SBC8803 significantly restored wakefulness and increased non-rapid eye movement (NREM) sleep during the second half of the active phase during CSD. The CSD-induced reduction in EEG slow wave activity, a marker of NREM sleep intensity, during the beginning of the inactive phase was significantly improved by SBC8803 supplementation. These findings suggest that dietary heat-killed SBC8803 confers beneficial effects on insomnia and circadian sleep disorders induced by psychophysiological stress.

Effect of lipopolysaccharide on circadian clock genes Per2 and Bmal1 in mouse ovary.

In mammals, circadian rhythms are associated with multiple physiological events. The aim of the present study was to examine the effect of lipopolysaccharide (LPS) on circadian systems in the ovary. Immature female mice were received an intra-peritoneal injection of equine chorionic gonadotropin (eCG) and LPS. Total RNA was collected from the ovary at 6-h intervals throughout a 48 h of experimental period. The expression of the circadian genes period 2 (Per2) and brain and muscle ARNT-like 1 (Bmal1) such as circadian genes was measured by quantitative PCR. Although expression of Per2 and Bmal1 in the ovary did not display clear diurnal oscillation, LPS suppressed the amplitude of Per2 expression. Additionally, LPS inhibited the expression of cytochrome P450 aromatase (CYP19) and luteinizing hormone receptor (LHr) genes in the ovary of eCG-treated mice. Our data suggest that Per2 may be associated with the inhibition of CYP19 and LHr expression by LPS in the ovaries of immature mice.

The anti-inflammatory effect of Agaricus brasiliensis is partly due to its linoleic acid content.

For hundreds of years mushrooms have been used as functional food for health. The basidiomycete Agaricus brasiliensis (A. brasiliensis) is famous for the medicinal properties of its beta glucans and of its antioxidants. Most researchers have studied polysaccharides from A. brasiliensis for their anti-inflammatory activity. However, active compounds from this mushroom have not yet been studied for the inactivation of NO inhibitory activity. The present study aimed to find the active compounds from A. brasiliensis for their NO inhibitory activity related inflammatory activity. This study found that linoleic acid isolated from A. brasiliensis inhibited NO production and suppressed the expression of pro-inflammatory cytokines including TNF-α, IL-6, IL-1ß, and NOS2 in RAW 264.7 cells. Linoleic acid also suppressed the expression of NF-κB subunit p50 and restored PPARα. This leads to the conclusion that linoleic acid from A. brasiliensis could reduce NO production and inflammatory activity in RAW 264.7 cells by the inhibition of p50 and via the activation of PPARα. This study suggests that linoleic acid present in A. brasiliensis could play a role in the prevention of inflammatory diseases for which this edible mushroom is already known.

Chronic sleep fragmentation exacerbates amyloid ß deposition in Alzheimer's disease model mice.

Sleep fragmentation due to intermittent nocturnal arousal resulting in a reduction of total sleep time and sleep efficiency is a common symptom among people with Alzheimer's disease (AD) and elderly people with normal cognitive function. Although epidemiological studies have indicated an association between sleep fragmentation and elevated risk of AD, a relevant disease model to elucidate the underlying mechanisms was lacking owing to technical limitations. Here we successfully induced chronic sleep fragmentation in AD model mice using a recently developed running-wheel-based device and demonstrate that chronic sleep fragmentation increases amyloid ß deposition. Notably, the severity of amyloid ß deposition exhibited a significant positive correlation with the extent of sleep fragmentation. These findings provide a useful contribution to the development of novel treatments that decelerate the disease course of AD in the patients, or decrease the risk of developing AD in healthy elderly people through the improvement of sleep quality.