Phytoceramide and sphingoid bases derived from brewer's yeast Saccharomyces pastorianus activate peroxisome proliferator-activated receptors

<p>Abstract</p> <p>Background</p> <p>Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that regulate lipid and glucose metabolism. PPARα is highly expressed in the liver and controls genes involved in lipid catabolism. We previously reported that synthetic sphingolipid analogs, part of which contains shorter-length fatty acid chains than natural sphingolipids, stimulated the transcriptional activities of PPARs. Sphingosine and dihydrosphingosine (DHS) are abundant sphingoid bases, and ceramide and dihydroceramide are major ceramide species in mammals. In contrast, phytosphingosine (PHS) and DHS are the main sphingoid bases in fungi. PHS and phytoceramide exist in particular tissues such as the epidermis in mammals, and involvement of ceramide species in PPARβ activation in cultured keratinocytes has been reported. The purpose of the present study is to investigate whether natural sphingolipids with C18 fatty acid and yeast-derived sphingoid bases activate PPARs as PPAR agonists.</p> <p>Method</p> <p>Lipids of brewer's yeast contain PHS- and DHS-based sphingolipids. To obtain the sphingoid bases, lipids were extracted from brewer's yeast and acid-hydrolyzed. The sphingoid base fraction was purified and quantified. To assess the effects of sphingolipids on PPAR activation, luciferase reporter assay was carried out. NIH/3T3 and human hepatoma (HepG2) cells were transfected with expression vectors for PPARs and retinoid × receptors, and PPAR responsive element reporter vector. When indicated, the PPAR/Gal4 chimera system was performed to enhance the credibility of experiments. Sphingolipids were added to the cells and the dual luciferase reporter assay was performed to determine the transcriptional activity of PPARs.</p> <p>Results</p> <p>We observed that phytoceramide increased the transcriptional activities of PPARs significantly, whereas ceramide and dihydroceramide did not change PPAR activities. Phytoceramide also increased transactivation of PPAR/Gal4 chimera receptors. Yeast-derived sphingoid base fraction, which contained PHS and DHS, or authentic PHS or DHS increased PPAR-dependent transcription. Additionally, phytoceramide stimulated PPARα activity in HepG2 hepatocytes, suggesting that phytoceramide activates genes regulated by PPARα.</p> <p>Conclusions</p> <p>Phytoceramide and yeast-derived sphingoid bases activate PPARs, whereas ceramide and dihydroceramide do not change the PPAR activity. The present findings suggest that phytoceramide acts as a PPAR ligand that would regulate PPAR-targeted genes.</p

Feasibility pilot study of a Japanese teaching kitchen program

BackgroundThis pilot study examined the feasibility of a new lifestyle modification program involving a “Teaching Kitchen” in Japan. Our goal was to explore (1) feasibility of the program; (2) acceptability for class frequency (weekly vs. bi-weekly); and (3) changes in biometrics, dietary intakes, and lifestyle factors.MethodsA total of 24 employees with obesity in a Japanese company were recruited. Participants were randomly divided into two groups (weekly or bi-weekly group), each attending the program consisting of four two-hour classes (lectures on nutrition, exercise, mindfulness, and culinary instructions). Participants were observed for changes in dietary intakes, biometrics, and health related quality of life over the subsequent 3 months. We tested the between-group differences in changes using linear mixed-effect models.ResultsThe program completion rates were 83.3% in total (91.7% for weekly group and 75.0% for bi-weekly group). From baseline to post-intervention, significant decreases were observed in weight (p &lt; 0.001), body mass index (p &lt; 0.001), diastolic blood pressure (p = 0.03), body fat mass (p &lt; 0.001), and dietary intakes in total fat (p = 0.03) and sodium (p = 0.008) among 17 participants who were available for measurements. Improvements in biometrics remained significant 1 month after the intervention (all p ≤ 0.03 in 14 participants). Participants' health related quality of life was significantly improved in bodily pain, general health, vitality, and mental component score (all p ≤ 0.047).ConclusionsThe new Japanese Teaching Kitchen program is feasible with high program completion rates in Japanese office workers with obesity. While this was a small feasibility study, significant multiple improvements in dietary intakes, biometrics, and health related quality of life suggest that this line of inquiry warrants further exploration to address obesity and obesity-related diseases in Japan

Probiotic-Derived Polyphosphate Enhances the Epithelial Barrier Function and Maintains Intestinal Homeostasis through Integrin–p38 MAPK Pathway

Probiotics exhibit beneficial effects on human health, particularly in the maintenance of intestinal homeostasis in a complex manner notwithstanding the diversity of an intestinal flora between individuals. Thus, it is highly probable that some common molecules secreted by probiotic and/or commensal bacteria contribute to the maintenance of intestinal homeostasis and protect the intestinal epithelium from injurious stimuli. To address this question, we aimed to isolate the cytoprotective compound from a lactobacillus strain, Lactobacillus brevis SBC8803 which possess the ability to induce cytoprotective heat shock proteins in mouse small intestine. L. brevis was incubated in MRS broth and the supernatant was passed through with a 0.2-µm filter. Caco2/bbe cells were treated with the culture supernatant, and HSP27 expression was evaluated by Western blotting. HSP27-inducible components were separated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P), a simple repeated structure of phosphates, which is a common product of lactobacilli and other bacteria associated with intestinal microflora without any definitive physiological functions. Then, poly P was synthesized by poly P-synthesizing enzyme polyphosphate kinase. The synthesized poly P significantly induced HSP27 from Caco2/BBE cells. In addition, Poly P suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of poly P (10 µg) improved the inflammation grade and survival rate in 4% sodium dextran sulfate-administered mice. This study, for the first time, demonstrated that poly P is the molecule responsible for maintaining intestinal barrier actions which are mediated through the intestinal integrin β1-p38 MAPK

Xanthohumol prevents atherosclerosis by reducing arterial cholesterol content via CETP and apolipoprotein E in CETP-transgenic mice.

BACKGROUND: Xanthohumol is expected to be a potent anti-atherosclerotic agent due to its inhibition of cholesteryl ester transfer protein (CETP). In this study, we hypothesized that xanthohumol prevents atherosclerosis in vivo and used CETP-transgenic mice (CETP-Tg mice) to evaluate xanthohumol as a functional agent. METHODOLOGY/PRINCIPAL FINDINGS: Two strains of mice, CETP-Tg and C57BL/6N (wild-type), were fed a high cholesterol diet with or without 0.05% (w/w) xanthohumol ad libitum for 18 weeks. In CETP-Tg mice, xanthohumol significantly decreased accumulated cholesterol in the aortic arch and increased HDL cholesterol (HDL-C) when compared to the control group (without xanthohumol). Xanthohumol had no significant effect in wild-type mice. CETP activity was significantly decreased after xanthohumol addition in CETP-Tg mice compared with the control group and it inversely correlated with HDL-C (%) (P<0.05). Furthermore, apolipoprotein E (apoE) was enriched in serum and the HDL-fraction in CETP-Tg mice after xanthohumol addition, suggesting that xanthohumol ameliorates reverse cholesterol transport via apoE-rich HDL resulting from CETP inhibition. CONCLUSIONS: Our results suggest xanthohumol prevents cholesterol accumulation in atherogenic regions by HDL-C metabolism via CETP inhibition leading to apoE enhancement

Xanthohumol increased apoE protein expression in CETP-Tg mice after 18 weeks.

<p>(A) Serum (upper) and HDL-fraction (lower), and (B) liver tissue. Data are represented as relative expression: the CETP-Tg mice control group was set at 1.0. (N = 8; CETP-Tg mice control, N = 8; CETP-Tg mice xanthohumol, N = 3; CETP-Tg mice Chow, N = 6; wild-type mice control, N = 7; wild-type mice xanthohumol) Means±SEM. *<i>P</i><0.05, **<i>P</i><0.01.</p

Expression analyses in mice liver and ab. aorta.

<p>(A) SR-B1 and (B) LCAT protein expression in liver. Data was standardized for β-actin expression. (N = 15; CETP-Tg mice control, N = 18; CETP-Tg mice xanthohumol, N = 11; CETP-Tg mice Chow, N = 6; wild-type mice control, N = 8; wild-type mice xanthohumol) (C, D) Transcript analyses of liver (upper) and ab. aorta (lower) in CETP-Tg mice (C) and wild-type mice (D). (N = 12; CETP-Tg mice control, N = 13; CETP-Tg mice xanthohumol, N = 9 to 10; CETP-Tg mice Chow, N = 5; wild-type mice control, N = 7 to 8; wild-type mice xanthohumol) All data were standardized for GAPDH expression. Expression levels of control group (without xanthohumol) were set at 1.0. Means±SEM. *<i>P</i><0.05, **<i>P</i><0.01.</p

Effect of xanthohumol on serum cholesterol and CETP activity.

<p>Serum HDL-C concentration in the control group (closed circle), xanthohumol group (opened circle) and Chow group (closed triangle) of CETP-Tg mice (A), and in the control group (closed square) and xanthohumol group (opened square) of wild-type mice (B) over time. (C) Serum CETP activity after 18 weeks of treatment. (D) Correlation of serum CETP activity and HDL-C/T-Cho (%) in CETP-Tg mice fed HCD after 18 weeks. CE content of serum (E) and HDL-fraction (F) after 18 weeks. (N = 15; CETP-Tg mice control, N = 16; CETP-Tg mice xanthohumol, N = 10; CETP-Tg mice Chow, N = 3; wild-type mice control, N = 8; wild-type mice xanthohumol) Means±SEM. *<i>P</i><0.05, **<i>P</i><0.01.</p

Changes in cholesterol accumulation over 18 weeks.

<p>Data are presented as cholesterol amount in the aortic arch (A) and liver (B). (N = 15; CETP-Tg mice control, N = 18; CETP-Tg mice xanthohumol, N = 12; CETP-Tg mice Chow, N = 10; wild-type mice control, N = 7; wild-type mice xanthohumol) Means±SEM. *<i>P</i><0.05, **<i>P</i><0.01.</p

Enzymatically synthesized poly P induced HSP27 from Caco2/BBE cells through the activation of p38 MAPK pathway.

<p>(A) HPLC chromatogram of poly P synthesized by PPK. (B) Western blot analysis of HSP27 induction in Caco2/BBE cells by poly P synthesized by PPK (0–100 µg/mL), (n = 3). (C) Poly P degradation by PPK treatment with 10 µM ADP led to an inability to induce HSP27 from Caco2/BBE cells (n = 3). (D) Poly P content in the culture supernatant of <i>L. brevis</i> 8803 at 8, 24 and 24 h from bacterial culture (n = 3). * Significantly different from corresponding control group at <i>P</i><0.05.</p

Anti-apoptopic property of HSP27-inducible fraction.

<p>Time course of inactive full-length caspase-3 and -9 degradation in Caco2/BBE induced by 1 µM staurosporine treatment in the presence or absence of HSP27-inducible fraction.</p