Mechanical allodynia triggered by cold exposure in mice with the Scn11a p.R222S mutation: a novel model of drug therapy for neuropathic pain related to NaV1.9.

Mutations within the SCN11A gene which encodes the voltage-gated sodium channel NaV1.9 mainly expressed in small fiber sensory neurons have been associated with neuropathic disorders; however, suitable medications have not been fully investigated. To develop drug therapies against NaV1.9-related neuropathic pain, we aimed to establish a novel model using mice carrying the Scn11a p.R222S mutation initially identified in patients with familial episodic limb pain that is characterized by paroxysmal pain induced by fatigue or bad weather conditions. We investigated the influence of cold exposure (4 °C, overnight) on the behavioral and biochemical phenotypes of Scn11a p.R222S mutant (R222S) and wild type C57BL/6N (WT) mice. We also tested the effects of acetaminophen (125, 250 mg/kg, perorally, p.o.) and traditional Japanese medicine, goshajinkigan (0.5 or 1.0 g/kg, p.o.), which are analgesic drugs prescribed to patients with neuropathic pain, in this model of cold-induced mechanical allodynia in R222S mice.Cold-exposed R222S mice exhibited enhanced mechanical allodynia and thermal hypersensitivity compared with WT mice. The decrease of the mechanical withdrawal threshold in R222S mice was reversible 24 h after housing at room temperature. There was no significant change in the levels of interleukin-1ß, interleukin-6, tumor necrosis factor-α, or interferon-γ in the plasma or spinal cords of WT and R222S mice after cold exposure. Both acetaminophen (250 mg/kg) and goshajinkigan (1.0 g/kg) significantly attenuated mechanical allodynia in R222S mice. The model of cold-induced mechanical allodynia in mice with the Scn11a p.R222S mutation is novel and useful for evaluating analgesic drugs for intractable neuropathies related to NaV1.9.

Mutant KCNJ3 and KCNJ5 Potassium Channels as Novel Molecular Targets in Bradyarrhythmias and Atrial Fibrillation.

BACKGROUND: Bradyarrhythmia is a common clinical manifestation. Although the majority of cases are acquired, genetic analysis of families with bradyarrhythmia has identified a growing number of causative gene mutations. Because the only ultimate treatment for symptomatic bradyarrhythmia has been invasive surgical implantation of a pacemaker, the discovery of novel therapeutic molecular targets is necessary to improve prognosis and quality of life. METHODS: We investigated a family containing 7 individuals with autosomal dominant bradyarrhythmias of sinus node dysfunction, atrial fibrillation with slow ventricular response, and atrioventricular block. To identify the causative mutation, we conducted the family-based whole exome sequencing and genome-wide linkage analysis. We characterized the mutation-related mechanisms based on the pathophysiology in vitro. After generating a transgenic animal model to confirm the human phenotypes of bradyarrhythmia, we also evaluated the efficacy of a newly identified molecular-targeted compound to upregulate heart rate in bradyarrhythmias by using the animal model. RESULTS: We identified one heterozygous mutation, KCNJ3 c.247A>C, p.N83H, as a novel cause of hereditary bradyarrhythmias in this family. KCNJ3 encodes the inwardly rectifying potassium channel Kir3.1, which combines with Kir3.4 (encoded by KCNJ5) to form the acetylcholine-activated potassium channel ( IKACh channel) with specific expression in the atrium. An additional study using a genome cohort of 2185 patients with sporadic atrial fibrillation revealed another 5 rare mutations in KCNJ3 and KCNJ5, suggesting the relevance of both genes to these arrhythmias. Cellular electrophysiological studies revealed that the KCNJ3 p.N83H mutation caused a gain of IKACh channel function by increasing the basal current, even in the absence of m2 muscarinic receptor stimulation. We generated transgenic zebrafish expressing mutant human KCNJ3 in the atrium specifically. It is interesting to note that the selective IKACh channel blocker NIP-151 repressed the increased current and improved bradyarrhythmia phenotypes in the mutant zebrafish. CONCLUSIONS: The IKACh channel is associated with the pathophysiology of bradyarrhythmia and atrial fibrillation, and the mutant IKACh channel ( KCNJ3 p.N83H) can be effectively inhibited by NIP-151, a selective IKACh channel blocker. Thus, the IKACh channel might be considered to be a suitable pharmacological target for patients who have bradyarrhythmia with a gain-of-function mutation in the IKACh channel.

Short-chain chlorinated paraffins in cooking oil and related products from China.

Short-chain chlorinated paraffins (SCCPs) are emerging persistent organic pollutants. It has been found that dietary intakes of SCCPs in China have recently increased and are now higher than in Japan and Korea. The contribution of cooking oil to dietary exposure to SCCPs in China was evaluated by analyzing SCCPs in cooking oil, raw seeds used to produce cooking oil, and fried confectionery products collected in China in 2010 and 2012. Detectable amounts of SCCP homologs were found in 48 out of the 49 cooking oil samples analyzed, and the SCCP concentrations varied widely, from <9 to 7500 ng g(-1). Estimated dietary intakes of total SCCPs in cooking oil ranged from <0.78 to 38 µg d(-1). The estimated dietary intake of SCCPs was relatively high (mean 14.8 µg d(-1)) for residents of Beijing. Fried confectionery was found to contain SCCP concentrations of 11-1000 ng g(-1). Cooking oil might therefore be one of the sources of SCCPs to Chinese diets. SCCPs were also detected in raw seeds used to produce cooking oil, but the concentrations varied widely. The SCCP homolog patterns in the raw seed and cooking oil samples were different, implying that the seeds used to produce the oil (and therefore the soil on which the seeds were produced) were unlikely to be the sources of SCCPs in cooking oil. Further investigations are needed to determine the routes through which cooking oil becomes contaminated with SCCPs during the production and processing of the oil.

Levels of urinary isoflavones and lignan polyphenols in Japanese women.

OBJECTIVES: High consumption of soybean products has been associated with a reduced risk of hormone-sensitive tumors. Soybean products contain phytoestrogens, such as daidzein, and sesame seeds contain secoisolariciresinol. These compounds are further metabolized to equol, enterodiol, and enterolactone by intestinal bacteria. However, individual differences in the metabolizing potential remain unclear. The aim of this study was to evaluate the urinary daidzein, equol, enterodiol, and enterolactone concentrations in women from several different regions of Japan according to age group. METHODS: Five hundred urine samples collected from Japanese women living in Sapporo, Sendai, Kyoto, Kochi, and Naha were analyzed for daidzein, equol, enterodiol, and enterolactone concentration by gas chromatography-mass spectrometry. RESULTS: The urinary isoflavone and lignan polyphenol levels did not differ significantly among the sampling sites, except for daidzein, which was highest in urine collected at Naha. The prevalence of equol producers was 39 % in the total study cohort. In equol producers, a positive correlation was observed between the urinary daidzein and equol levels (r = 0.399, p < 0.001). However, there was no significant difference between daidzein concentrations in equol producers and non-producers. Moreover, the levels of enterodiol and enterolactone were higher in equol producers than in equol non-producers. In the multivariate logistic analyses, two factors, Sendai dwelling and current smoking, were found to be significant [equol producers to non-producers: odds ratio 2.15 (95 % confidence interval: 1.17-4.02) and odds ratio 0.32 (0.15-0.63), respectively]. CONCLUSIONS: Our data suggest that geographic factors and smoking status should be considered during the evaluation of equol in urine samples and that the same pathway may be responsible for the metabolism of both isoflavones and lignan polyphenols.

Coffee, green tea, black tea and oolong tea consumption and risk of mortality from cardiovascular disease in Japanese men and women.

BACKGROUND: The effects of coffee and green, black and oolong teas and caffeine intake on cardiovascular disease (CVD) mortality have not been well defined in Asian countries. METHODS: To examine the relationship between the consumption of these beverages and risk of mortality from CVD, 76,979 individuals aged 40-79 years free of stroke, coronary heart disease (CHD) and cancer at entry were prospectively followed. The daily consumption of beverages was assessed by questionnaires. RESULTS: 1362 deaths were documented from strokes and 650 deaths from CHD after 1,010,787 person-years of follow-up. Compared with non-drinkers of coffee, the multivariable HR and 95% CI for those drinking 1-6 cups/week, 1-2 cups/day and ≥ 3 cups/day were 0.78 (0.50 to 1.20), 0.67 (0.47 to 0.96) and 0.45 (0.17 to 0.87) for strokes among men (p = 0.009 for trend). Compared with non-drinkers of green tea, the multivariable HR for those drinking 1-6 cups/week, 1-2 cups/day, 3-5 cups/day and ≥ 6 cups/day were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85) and 0.42 (0.17-0.88) for CHD among women (p = 0.038 for trend). As for oolong tea, the multivariable HR of those drinking 1-6 cups/week and ≥ 1 cups/day were 1.00 (0.65-1.55) and 0.39 (0.17-0.88) for total CVD among men (p = 0.049 for trend). Risk reduction for total CVD across categories of caffeine intake was most prominently observed in the second highest quintile, with a 38% lower risk among men and 22% among women. CONCLUSIONS: Consumption of coffee, green tea and oolong tea and total caffeine intake was associated with a reduced risk of mortality from CVD.

Ablation of estrogen receptor alpha (ERalpha) prevents upregulation of POMC by leptin and insulin.

Diabetic Akita male mice are more hyperphagic because of downregulation of proopiomelanocortin (POMC) caused by hypoleptinemia. We investigated the role of estrogen receptor alpha (ERalpha) in the regulation of the hypothalamic POMC in females. ERaKOAkt mice consumed 30% greater food (g/3 weeks) than the Akita diabetic controls. Ovariectomized diabetic (AFO) and nondiabetic (B6FO) mice had significantly lower food intake and elevated serum leptin levels. ERaKOAkt and ERaKO mice also increased serum leptin concentrations, while hypoinsulinemia was observed in ERaKOAkt and hyperinsulinemia in ERaKO mice. RT-PCR showed a significant attenuation of POMC expression in both ERaKOAkt and ERaKO mice, irrespective of the elevated leptin serum levels or hyperinsulinemia, while elevated serum leptin levels in AFO and B6FO mice upregulated POMC gene expression. These results indicate that ERalpha plays an essential role in leptin- and insulin-stimulated upregulation of the POMC gene. This action of ERalpha is likely mediated in a ligand-independent manner.

The ubiquitous environmental pollutant perfluorooctanoicacid inhibits feeding behavior via peroxisome proliferator-activated receptor-alpha.

Perfluorinated compounds (PFCs) have been employed as surface treatment agents in a variety of products. Perfluorooctanoic acid (PFOA), a PFC that is found globally in the environment and in human tissues, has been increasing significantly in serum levels over the past 50 years. Here, we demonstrated that PFOA inhibits feeding behavior as potently as the endogenous peroxisome proliferator-activated receptor (PPAR)-alpha ligand, oleoylethanolamide (OEA), via the activation of PPAR-alpha, the vagal nerve and hypothalamic neuropeptides. Peripherally administered PFOA decreased food intake as potently as OEA. PFOA decreased gastric emptying and increased the expression level of the gene encoding urocortin 1 in the hypothalamus and the immunoreaction for urocortin 1 in the paraventricular nucleus. Vagotomy attenuated the inhibitory effects of PFOA on feeding. The inhibition of food intake and body-weight gain by PFOA was completely mitigated in PPAR-alpha-/-mice. Our studies demonstrated that the ubiquitous environmental pollutant PFOA works as an imitator of OEA mimicking its action in the feeding regulatory system, providing a new mode of action as represented by environmental 'anorexigens'.

Roles of neuropeptides in O,O,S-trimethylphosphorothioate (OOS-TMP)-induced anorexia in mice.

O,O,S-Trimethylphosphorothioate (OOS-TMP), an impurity present in various organophosphorus insecticides, has previously been shown to induce hypophagia. The major goal of this study was to investigate its mechanism of action. Both intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) injection transiently induced hypophagia at a dose of 5mg/kg within 6h, without causing lung injury. Hypophagia was accompanied by up-regulation of corticotropin releasing factor (CRF) (2.92+/-0.45 vs. 1.7+/-0.5, at 2h after i.c.v., 3.40+/-1.38 vs. 1.76+/-0.41 at 6h after i.p., P<0.05) in the hypothalamus. After i.c.v. injection, hypophagia recovered by 6h after dosing. At doses higher than 5mg/kg, i.c.v. injection induced continuous hypophagia from 20min to 72h after dosing, accompanied by hypothermia and lung injury. OOS-TMP was considered to induce hypophagia through enhancing expression of CRF.

Perfluorooctane sulfonate influences feeding behavior and gut motility via the hypothalamus.

Perfluorinated compounds (PFCs) have been employed as surface treatment agents in a variety of products. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the two most commonly found PFCs in the environment and human blood. We investigated the effects of PFOS and PFOA on feeding behavior. PFOS or PFOA was administered intracerebroventricularly in mice or rats. Following administration, food intake, gastroduodenal motility, gastric emptying, gene expression of hypothalamic neuropeptides, and c-Fos expression along with immunoreaction for urocortin 2 in the paraventricular nucleus (PVN) were determined. Centrally administered PFOS and PFOA decreased food intake. Administration of PFOS decreased gastric emptying and disrupted the fasted motor activity in the antrum and duodenum. The gene expression of urocortin 2 in the hypothalamus and c-Fos expression and immunoreaction for urocortin 2 in the PVN were increased by the action of PFOS. A centrally administered corticotropin-releasing factor type 2 receptor (CRFR2) antagonist blocked PFOS-induced anorexia. These findings indicate that PFOS and PFOA influence feeding behavior. This effect is mediated via the activation of hypothalamic urocortin 2 and CRFR2, and the suppression of gastroduodenal motor activity. These observations indicate that PFCs may act centrally to influence behavior and physiological functions in humans.

Dimorphic gene expression patterns of anorexigenic and orexigenic peptides in hypothalamus account male and female hyperphagia in Akita type 1 diabetic mice.

Progression of the diabetic trait is usually more rapid in males than females. The major aim of the present study is to explore sexual dimorphism in the hypothalamus in Akita mice. Akita male mice develop hyperphagia, reducing anorexigenic proopiomelanocortin (POMC), and increasing orexigenic neuropeptide Y (NPY) mRNA levels compared with wt males. Serum leptin level was suppressed in Akita males, though castration improved these levels leading to reductions of hyperphagia and blood glucose levels. While Akita female mice also developed hyperphagia, there was no difference in POMC, NPY and leptin levels between Akita and wt females. Anorexigenic Cocaine- and amphetamine-regulated transcript (CART) and corticotrophin-releasing factor (CRF) mRNA levels in Akita females were decreased against wt females. Gonadectomy did not have any effect on the regulation of these neuropeptides. These data suggested that there is sexual dimorphism of neuronal regulation in hyperphagia in Akita mice.