Glucose Ingestion Inhibits Endurance Exercise-Induced IL-6 Producing Macrophage Infiltration in Mice Muscle

BACKGROUND: Carbohydrate (CHO) supplementation during exercise attenuates exercise-induced increases in plasma Interleukin (IL)-6 concentration. However, the effects of CHO supplementation on muscle IL-6 production during endurance exercise is controversial. The purpose of this study was to investigate the effects of CHO supplementation on muscle IL-6 production during endurance exercise with a special focus on the IL-6 producing cells. METHODS: C57BL/6J mice were divided into three groups-sedentary with water ingestion group as the control (Con; n = 10), exercise with water ingestion group (Ex; n = 10), and exercise with 6% glucose ingestion group (Ex + glucose; n = 10). The Ex and Ex + glucose groups completed 3 h of treadmill running (24 m/min, 7% incline) and were sacrificed immediately after exercise. RESULTS: The exercise-induced increases of plasma IL-6 concentration and gastrocnemius IL-6 gene expression were attenuated by glucose ingestion. However, the increases of soleus IL-6 gene expression and gastrocnemius and soleus IL-6 protein expression were not attenuated by glucose ingestion. Furthermore, we observed that macrophages that infiltrated muscle produce IL-6 and glucose ingestion attenuated the infiltration of IL-6-producing macrophages. CONCLUSION: This study revealed that infiltrating macrophages may be one type of IL-6-producing cells during endurance exercise, and the infiltration of these cells in muscle was attenuated by glucose ingestion. However, the effects of glucose ingestion on muscle IL-6 production were limited

Post-Transcriptional Control of the Hypoxic Response by RNA-Binding Proteins and MicroRNAs

Mammalian gene expression patterns change profoundly in response to low oxygen levels. These changes in gene expression programs are strongly influenced by post-transcriptional mechanisms mediated by mRNA-binding factors: RNA-binding proteins (RBPs) and microRNAs (miRNAs). Here, we review the RBPs and miRNAs that modulate mRNA turnover and translation in response to hypoxic challenge. RBPs such as HuR (human antigen R), PTB (polypyrimidine tract-binding protein), heterogeneous nuclear ribonucleoproteins (hnRNPs), tristetraprolin, nucleolin, iron-response element-binding proteins (IRPs), and cytoplasmic polyadenylation-element-binding proteins (CPEBs), selectively bind to numerous hypoxia-regulated transcripts and play a major role in establishing hypoxic gene expression patterns. MiRNAs including miR-210, miR-373, and miR-21 associate with hypoxia-regulated transcripts and further modulate the levels of the encoded proteins to implement the hypoxic gene expression profile. We discuss the potent regulation of hypoxic gene expression by RBPs and miRNAs and their integrated actions in the cellular hypoxic response

NADPH oxidase-derived reactive oxygen species are essential for differentiation of a mouse macrophage cell line (RAW264.7) into osteoclasts

Reactive oxygen species (ROS) derived from NADPH oxidase (Nox) homologues have been suggested to regulate osteoclast differentiation. However, no bone abnormalities have been documented in Nox1 deficient, Nox2 deficient, or Nox3 mutant mice. During receptor activator of nuclear factor-κB ligand (RANKL)-stimulated differentiation of a mouse macrophage cell line (RAW264.7) into osteoclasts, mRNA levels of Nox enzymes (Nox1-4) and their adaptor proteins were monitored by real-time reverse transcriptase PCR. RAW264.7 cells constitutively expressed abundant Nox2 mRNA and small amounts of Nox1 and Nox3 transcripts. RANKL markedly attenuated Nox2 mRNA expression in association with reciprocal up-regulation of Nox1 and Nox3 transcripts. Introduction of small interference RNA targeting p67phox or p22phox into RAW264.7 cells effectively downregulated ROS generation and significantly suppressed the RANKL-stimulated differentiation, which was assessed by appearance of tartrate resistant acid phosphatase (TRAP)- positive, multinucleated cells having an ability to form resorption pits on calcium phosphate thin film-coated disks, and by expression of osteoclast marker genes (TRAP, cathepsin K, Atp6i, ClC-7, and NFATc1). Our results suggest that RANKL may stimulate switching between Nox homologues during osteoclast differentiation, and Nox-derived ROS may be crucial for RANKL-induced osteoclast differentiation

Gene expression profiling in peripheral blood leukocytes as a new approach for assessment of human stress response

Stress is the coordinated physiological processes to maintain a dynamic equilibrium under stressful conditions. The equilibrium is threatened by certain physiological and psychological stressors. Stressors trigger physiological, behavioural, and metabolic responses that are aimed at reinstating homeostasis. The hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system play an essential role in the stress response. Excessive, prolonged, or inadequate response that is termed as “allostasis” or “allostatic load” leads to pathological outcomes. Dysregulation of the HPA axis activity is involved in the pathogenesis of stress related disorders including major depression. The complex brain-immune-endocrine network regulates the HPA axis, and hereditary predisposition as well as environmental factors such as traumatic experiences in early life also modifies the capacity of an individual to cope. Therefore, it is difficult to correctly assess the complex stress response. We have developed a microarray carrying 1,467 cDNAs that were selected to specifically measure stress response in peripheral blood leukocytes. Using this tool, we have succeeded to objectively assess individual response to acute psychological stress and to detect unique expression profiles in patients with depression. Gene expression profile in peripheral blood leukocytes may be a potentially useful for the detection of disease-associated, abnormal stress responses

Screening for Oral Cancer Using Electrochemical Telomerase Assay

Electrochemical telomerase assay (ECTA) developed by our group was evaluated in an oral cancer screening using exfoliated oral cells and tissues obtained from patients of oral cancer, mucosa associated disease, or healthy volunteers. Telomerase activity from ECTA is correlated with hTERT mRNA expression level using a real‐time PCR and was increasing in the following order: healthy volunteer group<mucosa associated disease group<oral cancer group. Sensitivity and specificity of ECTA were 88% and 72%, respectively when used 17% of the threshold value based on the receiver operating characteristic curve in ECTA data

Electrochemical telomerase assay for screening for oral cancer

Telomerase has long been known to be a marker for cancer. We have developed a new method of detecting it: the electrochemical telomerase assay (ECTA). We have previously confirmed that the assay is easier to do and more precise than the conventional telomeric repeat amplification protocol, which is currently the most widely used. Here we describe a pilot study made to establish a screening system for oral cancer using ECTA. We evaluated three types of clinical samples obtained from 44 patients with oral cancer and 26 healthy volunteers: exfoliated cells from the whole oral cavity, exfoliated cells from local lesions, and tissue from the lesion itself. The current increase ratio (Δi) obtained by ECTA was significantly higher in the oral cancer group for each type of sampling used. The threshold value for Δi was 19% when calculated by analysis of receiver-operating characteristic curves. Sensitivity and specificity values were 86% and 85% for cells from the oral cavity, 82% and 85% in cells from local lesions, and 95% and 92% in cells from the tumour itself, respectively. There were also no significant differences in sensitivity and specificity associated with age, size of tumour, site of lesion, or degree of malignancy. ECTA therefore seems to be a promising assay for screening for oral cancer

Enhanced translation by Nucleolin via G-rich elements in coding and non-coding regions of target mRNAs

RNA-binding proteins (RBPs) regulate gene expression at many post-transcriptional levels, including mRNA stability and translation. The RBP nucleolin, with four RNA-recognition motifs, has been implicated in cell proliferation, carcinogenesis and viral infection. However, the subset of nucleolin target mRNAs and the influence of nucleolin on their expression had not been studied at a transcriptome-wide level. Here, we globally identified nucleolin target transcripts, many of which encoded cell growth- and cancer-related proteins, and used them to find a signature motif on nucleolin target mRNAs. Surprisingly, this motif was very rich in G residues and was not only found in the 3′-untranslated region (UTR), but also in the coding region (CR) and 5′-UTR. Nucleolin enhanced the translation of mRNAs bearing the G-rich motif, since silencing nucleolin did not change target mRNA stability, but decreased the size of polysomes forming on target transcripts and lowered the abundance of the encoded proteins. In summary, nucleolin binds G-rich sequences in the CR and UTRs of target mRNAs, many of which encode cancer proteins, and enhances their translation

Analysis of Expressed Sequence Tags from the Fungus Aspergillus oryzae Cultured Under Different Conditions

We performed random sequencing of cDNAs from nine biologically or industrially important cultures of the industrially valuable fungus Aspergillus oryzae to obtain expressed sequence tags (ESTs). Consequently, 21 446 raw ESTs were accumulated and subsequently assembled to 7589 non-redundant consensus sequences (contigs). Among all contigs, 5491 (72.4%) were derived from only a particular culture. These included 4735 (62.4%) singletons, i.e. lone ESTs overlapping with no others. These data showed that consideration of culture grown under various conditions as cDNA sources enabled efficient collection of ESTs. BLAST searches against the public databases showed that 2953 (38.9%) of the EST contigs showed significant similarities to deposited sequences with known functions, 793 (10.5%) were similar to hypothetical proteins, and the remaining 3843 (50.6%) showed no significant similarity to sequences in the databases. Culture-specific contigs were extracted on the basis of the EST frequency normalized by the total number for each culture condition. In addition, contig sequences were compared with sequence sets in eukaryotic orthologous groups (KOGs), and classified into the KOG functional categories