Project description:Dietary collagen hydrolysate has been conjectured to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsic aged mice. Female 9-week-old hairless mice were fed a control diet, or a collagen hydrolysate-containing diet, for 12 weeks. The stratum corneum water content and skin elasticity were sequentially decreased by chronological aging in control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we comprehensively analyzed gene expression in the skin of mouse, which had been administered collagen hydrolysate, using DNA microarray. Twelve weeks after start of collagen intake, no significant differences appeared in gene expression profile compared to that of control group. However, 12 weeks after administration, 135 genes were up-regulated and 448 genes were down-regulated in collagen group compared to control group. It is indicate that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms, especially related to epidermal cell development, were signi?cantly enriched in up-regulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation and suppress dermal degradation. Thus, dietary collagen hydrolysate induced positive gene changes. In conclusion, our results suggest that alteration of gene expression at early stages after collagen administration affect skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of the skin tissue. Nine-week-old female Hos:HR-1 hairless mice (Japan SLC Inc., Shizuoka, Japan) were used in this study. All mice were housed in plastic cages (4 mice/cage) in a temperature and humidity controlled room (24 ± 1°C and 50 ± 10% humidity) under a 12 hour light-dark cycle. Mice were given an AIN-93G (Oriental Yeast Co., Ltd., Tokyo, Japan) diet and water. The present study was approved by the Animal Committee of Meiji Seika Kaisha Ltd., Food & Health R&D Laboratories, with the animals receiving care under the Guiding Principles for the Care and Use of Laboratory Animals of this committee. All surgery was performed under isoflurane anesthesia, and all efforts were made to minimize suffering. Sixteen female mice were randomly divided into two groups (n = 8 /group) according to their body weight, stratum corneum water content, and skin elasticity. During the experimental period for 12 weeks, the control group was fed a control diet (AIN-93G) and the collagen group was fed a collagen diet consisting of a mixture of 2.0 g of collagen hydrolysate and 100 g of the control diet. Fish scale collagen hydrolysate was purchased from Nitta Gelatin Inc. (Osaka, Japan). This amount of collagen hydrolysate is approximately equivalent to oral ingestion of 2.0 g collagen hydrolysate/kg body weight/day.

Project description:We have previously showed that whey protein hydrolysate (WPH) causes a greater increase in muscle protein synthesis than an identical composition of amino acids mixture does. The present study was conducted to investigate a comparative effect of WPH on gene expression. Male Sprague-Dawley rats subjected to a 2-h swimming exercise were administered either a carbohydrate-amino acid diet or a carbohydrate-WPH diet immediately after exercise. One hour after exercise, epitrochlearis muscle mRNA was sampled and subjected to DNA microarray analysis. As a result, ingestion of WPH altered 189 genes in considering the false discovery rate. Among the upregulated genes, 8 Gene Ontology (GO) terms were enriched, which included key elements in muscle repair after exercise such as Cd24, Ccl2, Ccl7 and Cxcl1. On the other hand, 9 GO terms were enriched in the gene sets downregulated by ingestion of WPH and these GO terms fell into 2 clusters, 'regulation of ATPase activity' and 'immune response'. Furthermore, we found that WPH activate the 2 upstream proteins, extracellular signal-regulated kinase 1/2 (ERK1/2) and hypoxia-inducible factor-1a (HIF-1a), which may act as key factors for regulation of gene expression. These results suggest that ingestion of WPH, compared to an identical composition of amino acid mixture, induces greater changes in the after-exercise gene expression profile via activation of the proteins, ERK1/2 and HIF-1a. Male Sprague-Dawley rats (5-week-old) with body weights of approximately 150 g each (CLEA Japan, Inc., Tokyo, Japan) were used in this study. Rats were maintained at 23 +/- 2C, with lights on from 8:00 to 20:00 and off from 20:00 to 8:00. Rats had free access to food (protein 23.6%, fat 5.3%, carbohydrate 54.4%, ash 6.1%, fiber 2.9%, moisture 7.7%, MF, Oriental Yeast Co., Ltd., Osaka, Japan) and water. After 2- or 3-day acclimation, the rats were pre-trained to swimming exercise for 3 days. One day before the experiment, they were fed 5 g of a restricted diet (MF, Oriental Yeast Co., Ltd., Osaka, Japan). On the day of the experiment, rats swam for 2 hours, with 4 rats swimming simultaneously in a barrel filled with water to a depth of 50 cm, allowing an average surface area of 400 cm2 for each animal. The water temperature was maintained at a constant of 35C. Immediately following exercise, rats were given one of two isoenergetic test solutions by gavage. These solutions contained 44 kJ in a four-test dose that represented about 15% of daily energy needs and included either a mixed meal containing carbohydrate and amino acid mixture (AAM) or a mixed meal containing carbohydrate and whey protein hydrolysate (WPH; Meiji Co., Ltd., Japan). This study was approved by the Animal Committee of Food Science Research Lab., Meiji Co., Ltd., with the animals receiving care according to the guidelines laid down by this committee.

Project description:VAAM stands for an amino acid mixture simulating the composition of Vespa, a hornet larval saliva. We conducted a comparative study on metabolism-regulatory roles of VAAM, casein-simulating amino acid mixture (CAAM), and pure water on murine hepatic and adipose tissue transcriptomes. Mice were orally fed VAAM solution ( 0.675 g/ kg BW = 2% of food-derived amino acids = 0.38% of total food energy/ day), CAAM solution ( 0.675 g / kg BW/ day) or water under ad libitum for five days. Hepatic transcriptome comparison of VAAM, CAAM and water-treated groups revealed a VAAM-specific regulation of the metabolic pathway, i.e., the down-regulation of glycolysis and fatty acid oxidation, and up-regulation of poly unsaturated fatty acid synthesis and glycogenic amino acids utilization in TCA cycle. Similar transcriptomic analysis of white and brown adipose tissues (WAT and BAT) suggested the up-regulation of phospholipid synthesis in WAT and the negative regulation of cellular processes in BAT. Because these coordinated regulations of tissue transcriptomes implicated the presence of upstream signaling common to these tissues, we conducted Ingenuity Pathways Analysis of these transcriptomes with the results that estrogenic and glucagon signals seemed to be activated in liver and WAT as well as beta-adrenergic signaling did in the three tissues by administration of VAAM. Our data provide a clue to understanding the role of VAAM in metabolic regulation of multiple tissues. Mice were divided randomly into three groups, VAAM, CAAM or water administered group. VAAM, CAAM or water was orally administrated five times once a day using feeding tube. The dosage of 1.8%VAAM, 1.8%CAAM or water was 37.5 microliter per gram of body weight. On day of last administration, food was removed and mice were moved to clean cages at 8:00. The last administrations started at 10:00. At 4 hours later after last administration, mice were sacrificed by cervical dislocation to collect blood, liver, white adipose tissue (WAT) and brown adipose tissue (BAT). Small hepatic pieces were immersed into RNAlater. WAT and BAT were frozen immediately after extraction using liquid nitrogen. All samples were extracted total RNA and hybridized on Affymetrix microarrays.

Project description:The mechanism by which phosphorus levels are maintained in the body was investigated by analyzing changes in gene expression in the rat kidney following administration of a high-phosphorus diet. Male Wistar rats were fed a high phosphorous (HP) diet containing 1.2% phosphorous, or 0.3% HP as a control, for 24 days. Phosphorous retention was not significantly increased in HP rats, but fractional excretion of phosphorus was significantly increased in the HP group compared to controls, with an excessive amount of the ingested phosphorus being passed through the body. DNA microarray analysis of kidney tissue from both groups revealed changes in gene expression profile induced by a HP diet. Among the genes that were upregulated, gene ontology (GO) terms related to ossification, collagen fibril organization, and inflammation and immune response were significantly enriched. In particular, there was significant upregulation of type IIb sodium-dependent phosphate transporter (NaPi-IIb) in the HP rat kidney compared to control rats. This upregulation was confirmed by in situ hybridization. Discreet signals for NaPi-IIb in both the cortex and medulla of the kidney were apparent in the HP group, while the corresponding signals were much weaker in the control group. Immunohistochemical analysis showed that NaPi-IIb localized to the basolateral side of kidney epithelial cells surrounding the urinary duct in HP rats but not in control animals. These data suggest that NaPi-IIb is upregulated in the kidney in response to the active excretion of phosphate in HP diet-fed rats. Male Wistar rats (4 weeks old) were purchased from Japan SLC Co. (Hamamatsu, Japan) and individually housed in metabolic cages under controlled conditions of 22Â±1Â°C and a 12-hour light/dark cycle (lights on from 08:00 to 20:00 daily). Two different diets containing 0.3% phosphorous (control diet) and 1.2% phosphorous (HP diet) were prepared based on the AIN-93G diet (Table 1). All rats were fed the control diet for a 7-day acclimatization period. After acclimatization, rats were divided into two groups of similar mean body weight (n = 5 each) and then fed either the control or the HP diet for 24 days. The animals were allowed to eat ad libitum and had free access to water (MilliQ water).The protocol for the animal experiments was approved by the Animal Use Committee of the Faculty of Agriculture at The University of Tokyo.

Dataset Information

Gene expression profiles in dorsal skin of hairless mice orally administrated collagen hydrolysate

Publications

Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.

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