Green tea (-)-epigallocatechin-3-gallate (EGCG) is known as to regulate obesity and fat cell activity. However, little information is known about the effects of EGCG on oxidative reactive oxygen species (ROS) of fat cells. Using 3T3-L1 preadipocytes and adipocytes, we found that EGCG increased ROS production in dose- and time-dependent manners. The concentration of EGCG that increased ROS levels by 180-500% was approximately 50 muM for a range of 8-16 h of treatment. In contrast, EGCG dose- and time-dependently decreased the amount of intracellular glutathione (GSH) levels. EGCG was more effective than (-)-epicatechin, (-)-epicatechin-3-gallate, and (-)-epigallocatechin in changing ROS and GSH levels. This suggests a catechin-specific effect. To further examine the relation of GSH to ROS as altered by EGCG, we observed that exposure of preadipocytes and adipocytes to N-acetyl-L-cysteine (a GSH precursor) blocked the EGCG-induced increases in ROS levels and decreases in GSH levels. These observations suggest a GSH-dependent effect of EGCG on ROS production. While EGCG was demonstrated to alter levels of ROS and GSH, its signaling was altered by an EGCG receptor (the so-called 67 kDa laminin receptor(67LR)) antiserum, but not by normal rabbit serum. These data suggest that EGCG mediates GSH and ROS levels via the 67LR pathway.
The qRT-PCR analysis of 139 clinical samples and analysis of 150 on-line database clinical samples indicated that AKT3 mRNA expression level was elevated in primary prostate tumors. Immunohistochemical staining of 65 clinical samples revealed that AKT3 protein expression was higher in prostate tumors of stage I, II, III as compared to nearby normal tissues. Plasmid overexpression of AKT3 promoted cell proliferation of LNCaP, PC-3, DU-145, and CA-HPV-10 human prostate cancer (PCa) cells, while knockdown of AKT3 by siRNA reduced cell proliferation. Overexpression of AKT3 increased the protein expression of total AKT, phospho-AKT S473, phospho-AKT T308, B-Raf, c-Myc, Skp2, cyclin E, GSK3β, phospho-GSK3β S9, phospho-mTOR S2448, and phospho-p70S6K T421/S424, but decreased TSC1 (tuberous sclerosis 1) and TSC2 (tuberous Sclerosis Complex 2) proteins in PC-3 PCa cells. Overexpression of AKT3 also increased protein abundance of phospho-AKT S473, phospho-AKT T308, and B-Raf but decreased expression of TSC1 and TSC2 proteins in LNCaP, DU-145, and CA-HPV-10 PCa cells. Oncomine datasets analysis suggested that AKT3 mRNA level was positively correlated to BRAF. Knockdown of AKT3 in DU-145 cells with siRNA increased the sensitivity of DU-145 cells to B-Raf inhibitor treatment. Knockdown of TSC1 or TSC2 promoted the proliferation of PCa cells. Our observations implied that AKT3 may be a potential therapeutic target for PCa treatment.
Galanin is a hormone 29 or 30 amino acids (aa) long that is widely distributed within the body and exerts numerous biological effects in vertebrates. To fully understand its physiological roles in reptiles, we analyzed preprogalanin cDNA structure and expression in the turtle pituitary. Using the Chinese soft-shell turtle (Pelodiscus sinensis order Testudines), we obtained a 672-base pair (bp) cDNA containing a 99-bp 5Ј-untranslated region, a 324-bp preprogalanin coding region, and a 249-bp 3Ј-untranslated region. The open-reading frame encoded a 108-aa preprogalanin protein with a putative 23-aa signal sequence at the NH 2 terminus. Based on the location of putative Lys-Arg dibasic cleavage sites and an amidation signal of Gly-Lys-Arg, we propose that turtle preprogalanin is processed to yield a 29-aa galanin peptide with Gly 1 and Thr 29 substitutions and a COOH-terminal amidation. Sequence comparison revealed that turtle preprogalanin and galanin-29 had 48 -81% and 76 -96% aa identities with those of other vertebrates, respectively, suggesting their conservative nature. Expression of the turtle galanin gene was detected in the pituitary, brain, hypothalamus, stomach, liver, pancreas, testes, ovaries, and intestines, but not in the adipose or muscle tissues, suggesting tissue-dependent differences. An in vitro study that used pituitary tissue culture indicated that treatment with 17-estradiol, testosterone, or gonadotropin-releasing hormone resulted in increased galanin mRNA expression with dose-or time-dependent differences, whereas leptin and neuropeptide Y reduced galanin mRNA levels. These results suggest a hormone-dependent effect on hypophyseal galanin mRNA expression.estrogen; androgen; gonadotropin-releasing hormone; neuropeptide Y; leptin GALANIN, a 29-amino acid (aa) hormone, was first isolated from porcine intestine and used to stimulate contractions of rat smooth muscle and to cause hyperglycemia in dogs (52). Since its discovery, galanin has also been found to exhibit numerous actions in vertebrates. For example, it induces feeding and the release of pituitary hormones [i.e., luteinizing hormone (LH) and growth hormone (GH)], decreases circulating levels of oxytocin, plays an antinociceptive role in the spinal cord, is involved in gastrointestinal motility and autonomic function, inhibits memory and learning, and promotes smooth muscle contractions (12). Moreover, clinical investigations have shown that galanin levels and galanin receptors are related to human disorders, such as Alzheimer disease and obesity (12). In reptiles, galanin can control gastrointestinal blood flow (24) and female oviposition (29). Although its mechanism of action in these reptilian physiological processes remains unknown, galanin in mammals reportedly operates via G i /G 0 -proteincoupled receptors involving effector systems such as K ϩ channels, Ca 2ϩ channels, and adenylate cyclase (3). In mice and humans, the galanin gene contains six exons and five introns (14, 26), and its mRNA consists of 398 -989 base pairs (bp),...
Sherman Alexie is an acclaimed Native American author who writes about growing up on the Spokane Indian reservation and the harsh realities of widespread poverty and alcoholism. This paper aims to examine his reconstruction of Native American identity in his young adult novel, The Absolutely True Diary of a Part-Time Indian. This book presents a Native American's education, culture, and wounds through the eyes of a teenage boy named Arnold. The phrase "absolutely true diary" hints at the semi-autobiographical nature of Alexie's novel; like Arnold, Alexie grew up on the Spokane Indian Reservation and transferred to the all-white high school in Reardon to escape the hopelessness of the rez. The words "part-time" signify Arnold's struggle to reconcile his disparate experiences in the white world and the Indian world. Caught between the two, he must reconstruct his Native American identity to find his own place in the world.
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