Association between Gut Microbiota and Body Composition in Japanese General Population: A Focus on Gut Microbiota and Skeletal Muscle.

This study aimed to investigate the gut microbial genera associated with skeletal muscle mass, using a large-scale survey from the standpoint of preventing sarcopenia. A total of 848 participants were included in the analysis. The mean (SD) ages of men (n = 353) and women (n = 495) were 50.0 (12.9) years and 50.8 (12.8) years, respectively. Body composition was assessed using appendicular skeletal muscle mass/body weight (ASM/BW), ASM, and BW. Additionally, the relationship between gut microbial genera and body composition was analyzed. The means (SD) of ASM/BW were 34.9 (2.4) % in men and 29.4 (2.9) % in women. Blautia and Bifidobacterium were positively associated with ASM/BW only in men (Blautia: ß = 0.0003, Bifidobacterium: ß = 0.0001). However, Blautia was negatively associated with BW (ß = -0.0017). Eisenbergiella was positively associated with ASM/BW (ß = 0.0209) and negatively associated with BW (ß = -0.0769) only in women. Our results indicate that Blautia, Bifidobacterium and Eisenbergiella, which are positively associated with ASM/BW, might help increase skeletal muscle mass. ASM/BW may clarify the relationship between gut microbiota and skeletal muscle mass without being affected by obesity or excess body fat mass.

[The Analgesic Effect of Aspirin on Inflammatory Pain in Rats Is Affected by Pain Intensity and Administration Timing].

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely known as painkillers. The analgesic action of NSAIDs is attributable to the inhibition of prostaglandin synthesis that occurs in response to blocking cyclooxygenase activity. The effective dose of NSAIDs can vary depending on pain intensity and administration timing; however, there are few studies on this. This study aimed to elucidate whether the analgesic effect of NSAIDs changes depending on the situation in which they are taken and we focused on the NSAID, aspirin (ASP). In a rat model of brewer's yeast-induced inflammation, pain caused by 20% (w/v) brewer's yeast-treatment was defined as "strong pain" and that caused by 2.5% (w/v) was defined as "weak pain". The analgesic effect of ASP (low-dose; 44 mg/kg or high-dose; 66 mg/kg) against strong pain was dose-dependent, but that against weak pain was the same. Furthermore, we defined drug administration after 3 h of brewer's yeast-treatment as "late administration" and that after 20 min as "early administration". In the case of strong pain, the analgesic effect of "late ASP administration" was dose-dependent, but that of "early ASP administration" was the same. These results suggest that low-dose NSAIDs have an analgesic effect against weak pain or when taken early.

Oral administration of Japanese sake yeast (Saccharomyces cerevisiae sake) promotes non-rapid eye movement sleep in mice via adenosine A2A receptors.

We have demonstrated previously that Japanese sake yeast improves sleep quality in humans. In the present study, we examined the molecular mechanisms of sake yeast to induce sleep by monitoring locomotor activity, electromyogram and electroencephalogram in mice. Oral administration of Japanese sake yeast (100, 200, and 300 mg kg-1 ) decreased the locomotor activity by 18, 46 and 59% and increased the amount of non-rapid eye movement (NREM) sleep by 1.5-, 2.3- and 2.4-fold (to 37 ± 6, 57 ± 8, and 60 ± 4 min from 25 ± 6 min in the vehicle-administered group, respectively) in a dose-dependent manner for 4 h after oral administration. However, Japanese sake yeast did not change the amount of rapid eye movement (REM) sleep, the electroencephalogram power density during NREM sleep or show any adverse effects, such as rebound of insomnia, during 24 h postadministration and on the next day. An intraperitoneal pretreatment with an adenosine A2A receptor-selective antagonist, ZM241385 (15 mg kg-1 ), reduced the amount of NREM sleep of sake yeast-administered mice to the basal level, without changing basal amount of sleep. Conversely, an A1 receptor-selective antagonist, 8-cyclopentyltheophylline (10 mg kg-1 ), did not affect the sleep-promoting effect of Japanese sake yeast. Thus, Japanese sake yeast promotes NREM sleep via activation of adenosine A2A but not A1 receptors.

Japanese sake yeast supplementation improves the quality of sleep: a double-blind randomised controlled clinical trial.

Activation of adenosine A2a receptors in cerebral neurons induces sleep in various mammals. It was previously found that Japanese sake yeast enriched in adenosine analogues activates A2a receptors in vitro and induces sleep in mice. Here it is reported that sake yeast activated A2a receptors in a cultured human cell line and improved human sleep quality in a clinical trial. Sake yeast activated A2a receptors in HEK cells in a dose-dependent manner with an EC50 of 40 µg mL(-1), and the activation was attenuated almost completely by the A2a receptor antagonist ZM241385 with an IC50 of 73 nm. In a double-blind placebo-controlled crossover clinical study, 68 healthy participants ingested tablets containing either 500 mg of sake yeast powder or a placebo (cellulose) 1 h before sleep for 4 days. Electroencephalograms were recorded during sleep at home with a portable device for 4 week days. Electroencephalogram analyses revealed that sake yeast supplementation significantly (P = 0.03) increased delta power during the first cycle of slow-wave sleep by 110%, without changing other sleep parameters. Sake yeast supplementation also significantly increased growth hormone secretion in the urine on awakening by 137% from 3.17 ± 0.41 (placebo) to 4.33 ± 0.62 (sake yeast) pg mg(-1) creatinine (P = 0.03). Subjective sleepiness (P = 0.02) and fatigue (P = 0.06) in the morning were improved by sake yeast. Given these benefits and the absence of adverse effects during the study period, it was concluded that sake yeast supplementation is an effective and safe way to support daily high-quality, deep sleep.

Lipid peroxides induce early onset of catagen phase in murine hair cycles.

The precise mechanisms of alopecia, a pathophysiological disorder with negative psychological implications, are unknown. Androgen and hereditary predisposition are major causes, but the condition is also affected by stress, an irregular diet and high levels of sebum secretion. We focused on oxidative stress and analyzed the effect of the lipid peroxides on hair follicles. Our first observation was that the topical application of linolein hydroperoxides, one of the lipid peroxides, lead to the early onset of the catagen phase in murine hair cycles. Furthermore, by using TUNEL staining we found that lipid peroxides induced apoptosis of hair follicle cells. They also induced apoptosis in human epidermal keratinocytes by up-regulating apoptosis-related genes. These results indicated that lipid peroxides, which can cause free radicals, induce the apoptosis of hair follicle cells, and this is followed by early onset of the catagen phase. These observations may provide insight into the mechanisms underlying the development of alopecia in humans.

Ephrin-A3 not only increases the density of hair follicles but also accelerates anagen development in neonatal mice.

BACKGROUND: Ephrins are cell-membrane-bound ligands for Eph receptor tyrosine kinases (Eph). Although ephrins are known to regulate a variety of developmental processes, little is known of their role in hair development. Previously, we studied the gene expression of dermal papilla cells from androgenetic alopecia and found that ephrin-A3 was significantly down-regulated. OBJECTIVE: To characterize the expression of ephrin-A3 in the hair cycle and evaluate the effect of ephrin-A3 on hair growth. METHODS: We investigated gene expression and protein expression of each ephrin-As and EphAs in the skin of neonatal mice through the first and second hair cycle using quantitative PCR and immunohistochemical analysis, respectively. We also injected ephrin-A3 protein into the skin of neonatal mice and demonstrated the effect of ephrin-A3 on hair follicle development. RESULTS: Expression of ephrin-A3 revealed a rapid increase at the beginning of the anagen phase, a peak during the mid-anagen, and a rapid fading during the telogen phase. In addition, we found ephrin-A3 protein was expressed in the developing hair follicles with a characteristic spatiotemporal localization. Furthermore, injection of ephrin-A3 into the skin of neonatal mice markedly accelerated the differentiation process of hair follicles. In addition, injection of ephrin-A3 unexpectedly increased the number of hair follicles. CONCLUSION: These findings demonstrated that ephrin-A3 not only accelerates anagen development but also increases the density of hair follicles, and also suggested that an ephrin-A-EphA signal pathway is closely involved in hair follicle development.

Different gene expression profile observed in dermal papilla cells related to androgenic alopecia by DNA macroarray analysis.

BACKGROUND: Androgenic alopecia (AGA) is the most common type of baldness in men. Although etiological studies have proved that androgen is one of the causes of this symptom, the defined molecular mechanism underlying androgen-related actions remains largely unknown. OBJECTIVES: To clarify the difference in the gene expression profile of dermal papilla cells (DPCs) in skin affected by baldness. METHODS: DNA macroarray study was carried out on cultured DPCs from AGA skin comparing with DPCs from skin that is not affected by baldness. RESULTS: From DNA macroarray analysis, we observed that 107 of the 1185 analyzed genes had differing expression levels. A marked difference was observed in the decreased gene expression of BMP2 and ephrin A3 and up-regulated in NT-4 gene. In order to clarify the roles of BMP2 and ephrin A3 in the hair follicles, we examined the proliferation of hair follicle keratinocyte and expression of a hair acidic keratin gene. Both BMP2 and ephrin A3 raised the proliferation rate of the outer root sheath cells (ORSCs) and induced gene expression in acidic hair keratin 3-II. CONCLUSION: These results lead us to the hypothesis that both BMP2 and ephrin A3 function as hair growth promoting factors in the hair cycle.