Project description:The quality control and export of mRNA by RNA-binding proteins are necessary for the survival of malaria parasites, which have complex life cycles. Malarial nuclear poly(A) binding protein 2 (NAB2), ALWAYS EARLY (ALY) and serine/arginine-rich (SR) proteins, such as nucleolar protein 3 (NPL3), G-strand binding protein 2 (GBP2) and SR1, are involved in nuclear mRNA export in malaria parasites. However, their functions and cellular localization are not fully understood. In this study, we found that NAB2 and SR1, but not ALY, NPL3 or GBP2, played essential roles in the asexual development of malaria parasites, while GBP2 was involved in gametocyte production. Moreover, GBP2 localized to both the nucleus and cytoplasm of malaria parasites and interacted with the proteins ALBA4, DOZI and CITH, which play roles in translational repression. Our findings suggest that malarial GBP2 may be involved in the recruitment of ALBA4, DOZI and CITH. Immunoprecipitation coupled to mass spectrometry (IP-MS) revealed that PHAX domain-containing protein, an adaptor protein for exportin-1, also interacted with GBP2, suggesting that mRNA export occurs via the PHAX domain-containing protein pathway in malaria parasites. Fluorescence live cell imaging revealed that malarial NAB2 localized at the nuclear periphery and co-localized with NUP205. Moreover, using IP-MS, we found that malarial NAB2 interacted with transportin. RNA immunoprecipitation coupled to RNA sequencing revealed that malarial NAB2 bound directly to 143 mRNAs, including those encoding 40S and 60S ribosomal proteins. This indicates that malarial NAB2 is involved in general mRNA assembly and is shuttled between the nucleus and cytoplasm. Our findings suggest that unique mRNA export and post-transcriptional gene regulation mediated by RNA-binding proteins occur in malaria parasites.
Project description:The functional balance between brown adipose tissue (BAT) and white adipose tissue (WAT) is important for metabolic homeostasis. We compared the effects of fasting on the gene expression profiles in BAT, WAT and liver, using DNA microarray analysis. Tissues were obtained from rats that had been fed or fasted for 24 h. Taking the false discovery rate (FDR) into account, we extracted the top 1,000 genes that were expressed differentially between fed and fasted rats. In all three tissues, Gene Ontology analysis revealed marked changes in the expression of âmetabolismâ category genes and a hypergeometric test demonstrated that within this category, lipid and protein biosynthesis-related genes were down-regulated. These findings indicate simultaneous down-regulation of genes involved in energy-consuming pathways in the BAT, WAT and liver of fasted rats. In the BAT of fasted rats, there was marked up-regulation of genes in the âprotein ubiquitinationâ category, suggesting that the ubiquitin-proteasome system is involved in saving energy as an adaptation to food shortage. Experiment Overall Design: Rats (7-week-old) were given a commercial diet between 10:00 and 16:00 for 7 days. At 10:00 on day 8, they were divided into two groups that comprised animals of similar body weights. One group continued to be fed as described above (fed group, n=4 for array analysis), whereas the other group were not fed (fasted group, n=4 for array analysis). Both groups received water ad libitum. At 16:00 on day 8, the liver, interscapular BAT and perinephrial WAT were excised, and analyzed for fasting effect.
Project description:The effects of the administration of molecular hydrogen-saturated drinking water (hydrogen water) on hepatic gene expression were investigated in rats. Using DNA microarrays, 548 upregulated and 695 downregulated genes were detected in the liver after a 4-week administration of hydrogen water. Gene Ontology analysis revealed that genes for oxidoreduction-related proteins, including hydroxymethylglutaryl CoA reductase, were significantly enriched in the upregulated genes. 4-week-old male Sprague-Dawley rats were acclimatized for 4 days in a room maintained at 24 ± 3°C with a relative humidity of 55 ± 15% with a 12-h light-dark cycle (lights on at 7:00, off at 19:00) and were fed ad libitum on a commercial diet (MF, Oriental Yeast Co., Yokohama, Japan). After acclimatization, the rats were divided into two groups (n = 8 per group) with similar mean body weights. During a period of 4 weeks, one group (control group) was supplied with sterilized distilled water and the other (HW group) with hydrogen water produced by MiZ Co. Ltd. (Fujisawa, Japan), which contains 0.7 mM dissolved hydrogen (pH 7.4). All the animals drank water ad libitum. After 4 weeks, each rat was anesthetized with diethyl ether and blood samples were collected from the abdominal aorta. The liver was then excised and analyzed the effect of hydrogen water extract administration on hepatic gene expression.
Project description:Previously, we constructed a coculture model to analyze the effect of macrophages on intestinal epithelial cells, and found that TNF-a secreted from human macrophage-like THP-1 cells induced cell damage to intestinal epithelial Caco-2 cells (Exp.Cell.Res. 2006, 312(19):3909-19). In this study, we present activation of NF-kB in Caco-2 cells within 15 min after coculturing. To reveal how TNF-a secreted from THP-1 cells affects Caco-2 cells in an early stage of coculture, we exhaustively analyzed the changes of gene expression in Caco-2 cells cocultured with THP-1 cells over the time periods of 0, 1, 3, 6, 24, and 48 h by using a DNA microarray. Differentially expressed genes extracted with maSigPro demonstrated that IEX-1 was the lowest p-value gene, that is, the most significantly changed gene among the up-regulated genes. The genes expressed in a similar pattern to IEX-1 involved immunity, apoptosis, and protein kinase cascade. These findings suggest that the stimuli of TNF-a from THP-1 cells activates NF-kB, leading induction of various gene expression. This pattern of gene expression indicates that not only early defense response but also cell death occurs at the same time, causing inflammatory condition. Caco-2 cells were cultured for 14 days on a semi-permeable support, and THP-1 cells were differentiated with phorbol myristate acetate (PMA) for 4 days in 12-well plates. Then, the semi-permeable support membrane in which Caco-2 cells had been cultured was placed on the 12-well plates on which THP-1 has been cultured.
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:Persimmon (Diospyros kaki L. f.) is a most popular fruit in Asian countries but its peels are totally wasted despite of containing a plenty of antioxidants such as carotenoids and polyphenols. We prepared a fat-soluble extract from a persimmon peel (PP) fraction and fed type 2 diabetic Goto-Kakizaki (GK) rats with a PP extract-containing AIN-93G diet (PP diet) for 12 weeks. Compared with the control AIN-93G diet, the feeding of the PP diet reduced the plasma glutamic-pyruvate transaminase activity significantly, with accumulation of M-NM-2-cryptoxanthin in the liver. A DNA microarray analysis revealed that the PP diet altered the hepatic gene expression profiles. In particular, insulin signaling pathway-related genes were significantly enriched in differentially expressed gene sets. Moreover, Western blotting analysis actually showed the promotion of IRM-NM-2 tyrosine phosphorylation. All these data suggest that the PP extract administration to the GK rats improves their insulin resistance. Male GK rats (90M-bM-^@M-^S107 g), aged 5 weeks, were purchased from Japan SLC Co. (Hamamatsu, Japan). The rats were maintained in a room at 22 M-BM-1 1M-BM-0C under a 12-h light-dark cycle (lights on at 0800) and administered a commercial diet (AIN-93G, Research Diets, Inc., New Brunswick, NJ, USA) for a week. The rats were allowed free access to diet and water. After one week, they were divided into two groups with similar average body weights. The control group rats (n = 4) were fed on the commercial diet, and the PP group rats (n = 4) on the same diet containing the PP extract. After the 12-week-feeding the liver was excised and analyzed the effect of PP extract administration on hepatic gene expression.
Project description:This study was aimed at examining the effects of long-term of heat-stress on the gene expression of skeletal muscle hypertrophy. Heat- and stream-generating (HSG) sheets were placed on thigh laterally. The HSG sheets (heat-stress) were applied 8-hrs/day, once a day, 4 days/weeks, for 10 weeks. A muscle biopsy was taken from the vastus lateralis muscle (2 cm depth) of the treated leg before and after the experiment. Oligonucleotide microarray revealed that genes related to ATP-synthesis, protein synthesis and the molecular chaperonic activity were increased by heat stress. These results suggest that heat-stress might be a useful countermeasure for muscular atrophy during aging. Overall design: Five subjects were applied by heat- and stream-generating (HSG) sheets for 10 weeks. Total RNAs obtained from the skeletal muscle before and after the experiment were used for the analysis.
Project description:Interaction between the host and invading pathogen determines the fate of both organisms during the infectious state. The host is equipped with a battery of immune reactions, while the pathogen displays a variety of mechanisms to compromise host immunity. Although bacteria alter their pattern of gene expression when they enter host organisms, studies to elucidate the mechanism behind this are only in their infancy. In the present study, we examined the possibility that host immune proteins directly participate in the change of gene expression in bacteria. To this end, Escherichia coli was treated with a mixture of the extracellular region of membrane-bound peptidoglycan recognition protein LC (PGRP-LC) and the antimicrobial peptide attacin of Drosophila, and subsequently subjected to DNA microarray analysis for the repertoire of mRNA. We identified nearly 200 genes whose mRNA increased after the treatment, and at least four of them were induced in response to PGRP-LC. One such gene, lipoprotein-encoding nlpI, showed a transient increase of its mRNA level in adult flies depending on PGRP-LC, and NlpI-lacking E. coli had a smaller pathogenic effect with lowered growth/viability than the parental strain in adult flies. These results suggest that a host immune receptor triggers a change of gene expression in bacteria simultaneously to their recognition of the invader and induction of immune responses. The E. coli strain BW25113 (2 x 10^9) suspended with insect saline (0.13 M NaCl, 4.7 mM KCl, 1.9 mM CaCl2), was incubated with a mixture of GST-attacin (0.125 μM), GST-PGRP-LCa (0.5 μM), GST-PGRP-LCx (1 μM), and GST-PGRP-LCy (0.5 μM) for 10 min at room temperature. As a negative control, incubation of E. coli was done in the presence of GST alone (3 μM).
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 22±1°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.