[Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases]

OBJECTIVE

To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.

METHODS

In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.

RESULTS

All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).

CONCLUSION

For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

Investigation of Proteus vulgaris and Elizabethkingia meningoseptica invasion on muscle oxidative stress and autophagy in Chinese soft-shelled turtle (Pelodiscus sinensis)

Muscle is an important structural tissue in aquatic animals and it is susceptible to bacterial and fungal infection, which could affect flesh quality and health. In this study, Chinese soft-shelled turtles were artificially infected with two pathogens, Proteus vulgaris and Elizabethkingia meningoseptica and the effects on muscle nutritional characteristics, oxidative stress and autophagy were assayed. Upon infection, the muscle nutritional composition and muscle fiber structure were notably influenced. Meanwhile, the mRNA expression of Nrf2 was down-regulated and Keap1 up-regulated, thus resulting in a decrease in antioxidant capacity and oxidative stress. However, with N-acetylcysteine treatment, the level of oxidative stress was decreased, accompanied by significant increases in antioxidant enzyme activities and the mRNA levels of SOD, CAT, GSTCD, and GSTO1. Interestingly, there was a significant increase in autophagy in the muscle tissue after the pathogen infection, but this increase could be reduced by N-acetylcysteine treatment. Our findings suggest that muscle nutritional characteristics were dramatically changed after pathogen infection, and oxidative stress and autophagy were induced by pathogen infection. However, N-acetylcysteine treatment could compromise the process perhaps by decreasing the ROS level and regulating Nrf2-antioxidant signaling pathways.

SREBP-1 and LXRα pathways mediated Cu-induced hepatic lipid metabolism in zebrafish Danio rerio

The present study was performed to explore the underlying molecular mechanism of Cu-induced disorder of lipid metabolism in fish. To this end, adult zebrafish were exposed to three waterborne Cu concentrations (0 (control), 8 and 16 μg Cu/L, respectively) for 60 days. Hepatic Cu content and hepatosomatic index increased after waterborne Cu exposure. H&E and oil red O stainings showed extensive steatosis in the liver of Cu-exposed fish. Cu exposure up-regulated lipogenic enzymes activities of ME, ICDH, 6PGD, G6PD and FAS, but down-regulated CPTI activities. Transcriptomic analysis indicated that lipid metabolism related pathways were significantly enriched in both low-dose and high-dose Cu exposure group. Genes involved in lipogenic process from fatty acid biosynthesis, fatty acid elongation, fatty acid desaturation to glycerolipid biosynthesis were up-regulated by Cu. To elucidate the mechanism, LXRα inhibitor SR9243 and SREBP1 inhibitor fatostatin were used to verify the role of LXRα and SREBP1 in Cu-induced disorder of lipid metabolism. Both SR9243 and fatostatin significantly attenuated the Cu-induced increase of TG accumulation of hepatocytes. Meanwhile, SR9243 significantly attenuated the Cu-induced up-regulation of expression of lipogenic genes (acaca, fas, icdh, dgat1, moat2 and moat3), and fatostatin significantly attenuated the up-regulation of expression of acaca, fas, g6pd, dgat1 and moat2. Enzymes analysis showed both SR9243 and fatostatin blocked the Cu-induced increase of lipogenic enzymes activities. Taken together, our findings highlight the importance of LXRα and SREBP1 in Cu-induced hepatic lipid deposition, which proposed a novel mechanism for elucidating metal element exposure inducing the disorder of lipid metabolism in aquatic vertebrates.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Upstream regulators of apoptosis mediates methionine-induced changes of lipid metabolism

Although the role of methionine (Met), as precursor for l-carnitine synthesis, in the regulation of lipid metabolism has been explored. Met seems to have tissue- and species-specific regulatory effect on lipid metabolism, implying that the mechanisms in Met regulation of lipid metabolism is complex and may involve the upstream regulatory pathway of lipid metabolism. The present study was performed to determine the mechanism of apoptosis signaling pathways mediating Met-induced changes of hepatic lipid deposition and metabolism in fish, and compare the differences of the mechanisms between the fish and mammals. By iTRAQ-based quantitative proteome analyses, we found that both dietary Met deficiency and excess evoked apoptosis signaling pathways, increased hepatic lipid deposition and caused aberrant hepatic lipid metabolism of yellow catfish Pelteobagrus fulvidraco. Using primary hepatocytes from P. fulvidraco, inhibition of caspase by Z-VAD-FMK blocked the apoptotic signaling pathways with a concomitant reversal of Met deficiency- and excess-induced increase of lipid deposition, indicating that apoptosis involved the Met-mediated changes of hepatic lipid metabolism. Moreover, we explored the roles of three upstream apoptotic signaling pathways (PI3K/AKT-TOR pathway, cAMP/PKA/CREB pathway and LKB1/AMPK-FOXO pathway) influencing hepatic lipid metabolism of P. fulvidraco. The three upstream pathways participated in apoptosis mediating Met-induced changes of lipid metabolism in P. fulvidraco. At last, HepG2 cell line was used to compare the similarities of mechanisms in apoptosis mediating Met-induced changes of lipid metabolism between fish and mammals. Although several slight differences existed, apoptosis mediated the Met-induced changes of lipid metabolism between fish and mammals. The present study reveals novel apoptosis-relevant signal transduction axis which mediates the Met-induced changes of lipid metabolism, which will help understand the mechanistic link between apoptosis and lipid metabolism, and highlight the importance of the evolutionary conservative apoptosis signaling axis in regulating Met-induced changes of hepatic lipid metabolism.

Zinc reduces hepatic lipid deposition and activates lipophagy via Zn2+/MTF-1/PPARα and Ca2+/CaMKKβ/AMPK pathways

Zinc (Zn) deficiency is the most consistently discovered nutritional manifestations of fatty liver disease. Although Zn is known to stimulate hepatic lipid oxidation, little is known about its underlying mechanism of action in lipolysis. Given the potential role of lipophagy in lipid metabolism, the purpose of this study was to test the hypothesis that Zn attenuates hepatic lipid accumulation by modulating lipophagy. The present study indicated that Zn is a potent promoter of lipophagy. Zn administration significantly alleviated hepatocellular lipid accumulation and increased the release of free fatty acids in association with enhanced fatty acid oxidation and inhibited lipogenesis, which was accompanied by activation of autophagy. Moreover, Zn reduced lipid accumulation and stimulated lipolysis by autophagy-mediated lipophagy. Zn-induced up-regulation of autophagy and lipid depletion is free Zn2+-dependent in the cytosols. Zn-induced autophagy and lipid turnover involved up-regulation of the calcium/calmodulin-dependent protein kinase kinase-β (Ca2+/CaMKKβ)/AMPK pathway. Meanwhile, Zn2+-activated autophagy and lipid depletion were via enhancing metal response element-binding transcription factor (MTF)-1 DNA binding at PPARα promoter region, which in turn induced transcriptional activation of the key genes related to autophagy and lipolysis. Zn activated the pathways of Zn2+/MTF-1/ Peroxisome proliferator-activated receptor (PPAR)α and Ca2+/CaMKKβ/AMPK, resulting in the up-regulation of lipophagy and accordingly reduced hepatic lipid accumulation. Our study, for the first time, provided innovative evidence of the direct relationship between metal elements (Zn) and lipid metabolism. The present study also indicated the novel mechanism for Zn-induced lipolysis by the activation of Zn2+/MTF-1/PPARα and Ca2+/CaMKKβ/AMPK pathways, which induced the occurrence of lipophagy. These results provide new insight into Zn nutrition and its potential beneficial effects on the prevention of fatty liver disease in vertebrates.-Wei, C.-C., Luo, Z., Hogstrand, C., Xu, Y.-H., Wu, L.-X., Chen, G.-H., Pan, Y.-X., Song, Y.-F. Zinc reduces hepatic lipid deposition and activates lipophagy via Zn2+/MTF-1/PPARα and Ca2+/CaMKKβ/AMPK pathways.

Oxidative stress and mitochondrial dysfunction mediated Cd-induced hepatic lipid accumulation in zebrafish Danio rerio

The present study was performed to determine the effect of waterborne CdCl₂ exposure influencing lipid deposition and metabolism, oxidative stress and mitochondrial dysfunction, and explore the underlying molecular mechanism of cadmium (Cd)-induced disorder of hepatic lipid metabolism in fish. To this end, adult zebrafish were exposed to three waterborne CdCl₂ concentrations (0(control), 5 and 25 μg Cd/l, respectively) for 30 days. Lipid accumulation, the activities of enzymes related to lipid metabolism and oxidative stress, as well as the expression level of genes involved in lipid metabolism and mitophagy were determined in the liver of zebrafish. Waterborne CdCl₂ exposure increased hepatic triglyceride (TG) and Cd accumulation, the activities of fatty acid synthase (FAS), 6-phosphogluconate dehydrogenase (6PGD), glucose 6-phosphate dehydrogenase (G6PD) and malic enzyme (ME), and the mRNA level of fatty acid synthase (fas), acetyl-CoA carboxylase alpha (acaca), glucose 6-phosphate dehydrogenase (g6pd) and malic enzyme (me), but reduced the mRNA level of carnitine palmitoyl transferase 1 (cpt1), hormone-sensitive lipase alpha (hsla), and adipose triacylglyceride lipase (atgl). The activities of superoxide dismutase (SOD), glutathoinine peroxidase (GPx) and cytochrome c oxidase (COX) and the ATP level were significantly reduced after CdCl₂ exposure. CdCl₂ exposure significantly increased the mRNA level of genes (microtubule-associated protein light chain 3 alpha (lc3a), PTEN-induced putative kinase 1 (pink1), NIP3-like protein X (nix) and PARKIN (parkin)) related to mitophagy. To elucidate the mechanism, reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) and the mitochondrial permeability transition (MPT) inhibitor cyclosporine A (CsA) were used to verify the role of ROS and mitochondrial dysfunction in Cd-induced disorder of lipid metabolism. NAC pretreatment reversed the Cd-induced up-regulation of TG accumulation and activities of lipogenic enzymes, and the Cd-induced down-regulation of mRNA levels of lipolytic genes. Meanwhile, NAC pretreatment also blocked the mitochondrial membrane potential (MMP) collapse and decreased the ATP level, suggesting that ROS played a crucial role in regulating the Cd-induced mitochondrial dysfunction. Taken together, our findings, for the first time, highlight the importance of the oxidative stress and mitochondrial dysfunction in Cd-induced disorder of hepatic lipid metabolism, which proposed a novel mechanism for elucidating metal element exposure inducing the disorder of lipid metabolism in vertebrates.

Endoplasmic reticulum (ER) stress and cAMP/PKA pathway mediated Zn-induced hepatic lipolysis

The present study was performed to determine the effect of Zn exposure influencing endoplasmic reticulum (ER) stress, explore the underlying molecular mechanism of Zn-induced hepatic lipolysis in a fish species of significance for aquaculture, yellow catfish Pelteobagrus fulvidraco. We found that waterborne Zn exposure evoked ER stress and unfolded protein response (UPR), and activated cAMP/PKA pathway, and up-regulated hepatic lipolysis. The increase in ER stress and lipolysis were associated with activation of cAMP/PKA signaling pathway. Zn also induced an increase in intracellular Ca²⁺ level, which could be partially prevented by dantrolene (RyR receptor inhibitor) and 2-APB (IP3 receptor inhibitor), demonstrating that the disturbed Ca²⁺ homeostasis in ER contributed to ER stress and dysregulation of lipolysis. Inhibition of ER stress by PBA attenuated UPR, inhibited the activation of cAMP/PKA pathway and resulted in down-regulation of lipolysis. Inhibition of protein kinase RNA-activated-like ER kinase (PERK) by GSK2656157 and inositol-requiring enzyme (IRE) by STF-083010 differentially influenced Zn-induced changes of lipid metabolism, indicating that PERK and IRE pathways played different regulatory roles in Zn-induced lipolysis. Inhibition of PKA by H89 blocked the Zn-induced activation of cAMP/PKA pathway with a concomitant inhibition of ER stress-mediated lipolysis. Taken together, our findings highlight the importance of the ER stress-cAMP/PKA axis in Zn-induced lipolysis, which provides new insights into Zn toxicology in fish and probably in other vertebrates.

Dijet imbalance measurements in Au+Au and pp collisions at sqrt[s_{NN}]=200 GeV at STAR

We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2  GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature-momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2.

AKTs/PKBs: molecular characterization, tissue expression and transcriptional responses to insulin and/or wortmannin in yellow catfish Pelteobagrus fulvidraco

In the present study, four AKT isoforms termed AKT1, AKT2, AKT3a and AKT3b were isolated and characterized from yellow catfish. Their molecular characterizations, tissue expressions and transcriptional responses to insulin and/or wortmannin were determined. The validated complementary DNA (cDNA) of yellow catfish AKT1, AKT2, AKT3a and AKT3b were 1422, 1431, 1389 and 1440 bp in length, encoding the peptide of 472, 475, 462 and 479 amino acid residues, respectively. The amino acid sequences of yellow catfish AKTs possessed all the characteristics of AKTs in other species. AKT1, AKT2 and AKT3b contained a conserved domain structure including a specific PH domain, a central catalytic domain and a C-terminal regulatory domain, while AKT3a lacked the C-terminal regulatory domain. All mRNAs of AKTs were expressed at the highest levels in the ovary. Among other tissues, the messenger RNA (mRNA) of AKT1 was widely distributed in all tested tissues, and AKT2 mRNA was more abundant in the muscle, liver and fat and lowest in other tested tissues, while AKT3a mRNA was predominant in the brain and showed no significant difference among other tested tissues, and AKT3b mRNA was highly expressed in the ovary, followed by the brain, muscle and fat and was relatively low in other tissues. Intraperitoneal insulin injection and incubation increased the mRNA expression of AKT1 and AKT2, but not that of AKT3a and AKT3b in the liver and hepatocytes of yellow catfish. Wortmannin reduced the mRNA level of all AKT isoforms and also alleviated the insulin-induced changes of AKT2 expression. The present study cloned full-length cDNA sequences of four AKTs in fish and determined their tissue expression profiles and studied their transcriptional responses to insulin and/or wortmannin, which serves to increase our understanding of their physiological function in lipid metabolism in fish.

Identification of autophagy related genes LC3 and ATG4 from yellow catfish Pelteobagrus fulvidraco and their transcriptional responses to waterborne and dietborne zinc exposure

Autophagy mediates the regulation of lipid metabolism. Moreover, our recent study indicated that waterborne and dietborne zinc (Zn) exposure differentially influenced lipid metabolism in a fish species of significance for aquaculture, yellow catfish Pelteobagrus fulvidraco, but further mechanism remained unknown. The hypothesis of the present study is that autophagy mediated the Zn-induced changes of lipid metabolism of yellow catfish subjected to different exposure pathways. To this end, we cloned key genes involved in autophagy in yellow catfish, explored their mRNA expressions in responses to different Zn exposure pathways. Full-length cDNA sequences of two LC3 subtypes and six ATG4 isoforms were isolated from yellow catfish. More ATG4 members were firstly identified in fish that might have arisen by teleost-specific whole genome duplication events. All of these members shared similar domain structure to their orthologous genes of vertebrates. Their mRNAs were widely expressed in various tissues, but at variable levels. Extra Zn addition in water or diets induced (P < 0.05) mRNA expression of ATG4Da, ATG4Db and LC3B. Considering their important roles of these genes in lipid metabolism, ATG4Da, ATG4Db and LC3B may mediate the changes of Zn-induced hepatic lipid metabolism of yellow catfish under different Zn exposure pathways. For the first time, we characterized the full-length cDNA sequences of six ATG4 isoforms and two LC3 subtypes, determined their tissue expression profiles and transcriptional responses to different Zn exposure pathways, which would contribute to our understanding of the molecular basis of autophagy, and also provide new insights into physiological responses to different Zn exposure pathways.

[Clinical characteristics and prognosis of cultured negative pyogenic spondylitis]

OBJECTIVE

There are limited data describing the clinical characteristics and prognosis of culture negative pyogenic spondylitis. The aim of this study was to investigate the treatment, prognosis and clinical characteristics of culture negative pyogenic spondylitis.

METHODS

A retrospective study reviewed 74 patients who were diagnosed with spondylitis in Peking University First Hospital from January 2010 to December 2015. A total of 27 patients suffered from pyogenic spondylitis. According to the pathogenic culture results, the patients were divided into two groups: culture negative group and culture positive group. The clinical characteristics and treatment outcomes between the two groups were compared.

RESULTS

The elder were more vulnerable to pyogenic spondylitis, and of the 27 patients, 12 patients were female and 15 male. All patients had no history of administration of antibiotics prior to obtaining culture samples. A causative germ was identified in 14/27 patients (51.9%) with Staphylococcus aureus being the most common pathogen. There was no significant difference between the two groups in the patient's age, gender, visual analogue score (VAS), predisposing factor, clinical symptom, sign and spinal segment (P>0.05). Erythrocyte sedimentation rate (ESR) (P=0.056) and C-reactive protein (CRP) (P=0.040) of culture negative group were lower in contrast to culture positive group. The incidence of vertebral abscess in culture negative group was higher than in culture positive group (P=0.046). After treatment, ESR dropped almost equally in both groups, and CRP dropped faster in the culture positive group (P=0.192). At last, there was no significant difference between the two groups in hospital stay, pain relief, open debridement operation rate, and recurrence rate of infection.

CONCLUSION

ESR and CRP of the culture negative patient were lower than those of the culture positive patient, and the incidence rate of paravertebral abscess was higher than that of the culture positive patient. After administration of antibiotics, there was no significant difference between the two groups in duration of antibiotics, open debridement operation rate and recurrence rate of infection. So, culture negative may not necessarily be a negative prognostic factor for pyogenic spondylitis. However, we should watch out for the drug resistant bacteria or double infection, due to the long term use of wide-spectrum antibiotic in culture negative patients.

IRS1 and IRS2: molecular characterization, tissue expression and transcriptional regulation by insulin in yellow catfish Pelteobagrus fulvidraco

The insulin receptor substrate (IRS) proteins, in particular, IRS1 and IRS2, are the key downstream players of insulin signaling pathway and the regulation of lipid metabolism. In the present study, two genes of IRS (IRS1 and IRS2) were isolated and characterized from yellow catfish Pelteobagrus fulvidraco. Their molecular characterizations, tissue expressions, and transcriptional levels by insulin both in vivo and in vitro were determined. The validated complementary DNAs encoding for IRS1 and IRS2 were 3693 and 3177 bp in length, encoding proteins of 1230 and 1058 amino acid residues, respectively. Similarly to mammals, amino acid sequence alignment revealed that IRSs contained an N-terminal pleckstrin homology (PH) domain, a phosphotyrosine-binding (PTB) domain, and several C-terminal multiple sites of tyrosine phosphorylation. Both IRS1 and IRS2 were widely expressed across the ten tissues (liver, white muscle, spleen, brain, gill, mesenteric fat, anterior intestine, heart, mid-kidney, and ovary), but at the variable levels. Insulin injection at 1 μg/g in vivo significantly stimulated the messenger RNA (mRNA) expression of IRS2, but not IRS1 mRNA expression levels in the liver of yellow catfish after 48 h. In hepatocytes of yellow catfish, insulin incubation significantly stimulated the IRS1 (at a 1000 nM insulin group) and IRS2 (at both 100 and 1000 nM insulin groups) mRNA expressions, which indicated that IRS2 was more sensitive than IRS1 to insulin stimulation in the liver of yellow catfish, and IRS2 played a more important role in mediating insulin's effects on the liver metabolism. The present study serves to increase our understanding into the function of IRS in fish.

Charge-Dependent Directed Flow in Cu+Au Collisions at sqrt[s_{NN}]=200 GeV

We present the first measurement of charge-dependent directed flow in Cu+Au collisions at sqrt[s_{NN}]=200  GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, i.e., quarks and antiquarks, have not yet been created during the lifetime of the strong electric field, which is of the order of, or less than, 1  fm/c.

Effects and mechanisms of waterborne copper exposure influencing ovary development and related hormones secretion in yellow catfish Pelteobagrus fulvidraco

The present study was conducted to determine the effects and mechanism of waterborne copper (Cu) exposure influencing ovary development and related hormones secretion in yellow catfish Pelteobagrus fulvidraco. To this end, two experiments were conducted. In Exp. 1, the partial cDNA sequences of three steroidogenesis-related genes (androgen receptor (ar), steroidogenic factor 1 (sf-1) and steroidogenic acute regulatory protein (star)) were firstly characterized from P. fulvidraco. The predicted amino acid sequences for the P. fulvidraco ar, sf-1 and star contained the main structural features characteristic in other species. In Exp. 2, P. fulvidraco were exposed to three waterborne Cu concentrations (control, 30μg/l and 60μg/l, respectively) for 56days. Sampling occurred on day 28 and day 56, respectively. On day 28, the levels of serum sex-steroid hormones (FSH and LH) and the mRNA levels of steroidogenesis-related genes (3β-hsd, cyp11a1, cyp17, cyp19a, sf-1 and star) were significantly increased in ovary of P. fulvidraco exposed to 30μg Cu/l. The immunohistochemical analysis showed the positive reaction of ER, VTG and aromatase in low dose exposure group. These indicated that in low dose and relative short-term exposure, Cu was beneficial. In contrast, 60μg Cu/l exposure significantly reduced the levels of serum FSH, LH, E2 and P, and the mRNA levels of ovarian 20β-hsd, cyp19a and erα in P. fulvidraco. On day 56, waterborne Cu concentration exposure reduced the levels of serum gonadotropins and sex hormones, and down-regulated the mRNA levels of steroidogenesis-related genes, indicating long-term Cu exposure had toxic effect on the secretion of sex-steroid hormone in P. fulvidraco. For the first time, our study cloned cDNA sequences of ar, sf-1 and star in P. fulvidraco, and demonstrated the effects and mechanism of waterborne Cu exposure influencing hormones secretion and synthesis in dose- and time-dependent manner in P. fulvidraco, which will help to understand the Cu-induced reproductive toxicity at both protein and transcriptional levels in fish.

Effects of waterborne Cu exposure on intestinal copper transport and lipid metabolism of Synechogobius hasta

The present study was conducted to explore the effects of waterborne Cu exposure on intestinal Cu transport and lipid metabolism of Synechogobius hasta. S. hasta were exposed to 0, 0.4721 and 0.9442μM Cu, respectively. Sampling occurred on days 0, 21 and 42, respectively. Growth performance, intestinal lipid deposition, Cu content, and activities and mRNA expression of enzymes and genes involved in Cu transport and lipid metabolism were analyzed. Cu exposure decreased WG and SGR on days 21 and 42. Cu exposure increased intestinal Cu and lipid contents. Increased Cu accumulation was attributable to increased enzymatic activities (Cu-ATPase and Cu, Zn-SOD) and genes' (CTR1, CTR2, DMT1, ATP7a, ATP7b, MT1 and MT2) expression involved in Cu transport. Waterborne Cu exposure also increased activities of lipogenic enzymes (6PGD and ICDH on both days 21 and 42, ME on day 42), up-regulated mRNA levels of lipogenic genes (G6PD, 6PGD, ME, ICDH, FAS and ACCa), lipolytic genes (ACCb, CPT I and HSLa) and genes involved in intestinal fatty acid uptake (IFABP and FATP4) on both days 21 and 42. The up-regulation of lipolysis may result from the increased metabolic expenditure for detoxification and maintenance of the normal body functions in a response to Cu exposure. Meantime, Cu exposure increased lipogenesis and fatty acid uptake, leading to net lipid accumulation in the intestine despite increased lipolysis. To our knowledge, this is the first report involved in intestinal lipid metabolism in combination with intestinal Cu absorption following waterborne Cu exposure, which provides new insights and evidence into Cu toxicity in fish.

Five metal elements homeostasis-related genes in Synechogobius hasta: Molecular characterization, tissue expression and transcriptional response to Cu and Fe exposure

Two isoforms of Cu transporter (CTR1 and CTR2) and metallothionein (MT1 and MT2), and divalent metal ion transporter 1 (DMT1) were cloned and characterized in Synechogobius hasta, respectively. The protein sequences of S. hasta CTRs possessed two methionine-rich regions (MxM and MxxxM) and three transmembrane regions. At the C-terminus, CTR1 contained a sequence of conserved cysteine and histidine residues (HCH), while CTR2 did not contain the conserved sequence. The protein sequence of S. hasta DMT1 possessed all the characteristic features of DMT1, including twelve conserved hydrophobic cores of transmembrane domains. The protein sequences of S. hasta MTs were highly conserved in the total number of cysteine residues and their locations. mRNA of the five genes were expressed in a wide range of tissues but the levels were relatively higher in the liver. Cu exposure tended to up-regulate the mRNA expressions of CTR2, DMT1, MT1 and MT2. However, Fe down-regulated the Cu-induced increase of CTR2 and DMT1 mRNA levels. For the first time, our study cloned and characterized CTR1, CTR2, DMT1, MT1 and MT2 genes in S. hasta and determined their tissue-specific expression, and also the transcriptional change by Cu and Fe exposure, which shed new light on the CuFe relationship and help to understand the basic mechanisms of Cu and Fe homeostasis in fish.

Effect of waterborne zinc exposure on lipid deposition and metabolism in hepatopancreas and muscle of grass carp Ctenopharyngodon idella

The aim of the present study was to explore the effect of waterborne zinc (control, 0.85, 2.20, 3.10 mg/l, respectively) exposure on lipid deposition and metabolism in the hepatopancreas and muscle of grass carp Ctenopharyngodon idella. The lipid content, Zn accumulation, and the activities and expression levels of several enzymes involved in lipid metabolism were determined in hepatopancreas and muscle. Waterborne Zn exposure reduced growth performance and increased Zn accumulation in both tested tissues. In hepatopancreas, Zn exposure increased lipid content, the activities of lipogenic enzymes, such as 6PGD, G6PD, ME, ICDH and FAS, as well as the mRNA expression level of G6PD, 6PGD, ICDH, FAS and SREBP-1. But the activity of CPT I and the mRNA expression of HSL, CPT Iα1a, CPT Iα2a and PPARα were down-regulated by Zn exposure. In contrast, in muscle, waterborne Zn exposure decreased lipid deposition, activities of 6GPD, ICDH and ME, as well as the mRNA expression level of G6PD, ICDH, ME, FAS and SREBP-1. However, the activity of CPT I as well as the mRNA expression level of PPARα, HSL, CPT Iα2a, CPT Iα1b and CPT Iβ were up-regulated by Zn exposure. Our results indicate that waterborne Zn increases lipid content by up-regulating lipogenesis and down-regulating lipolysis in hepatopancreas. But, in muscle, waterborne Zn reduces lipid accumulation by up-regulating lipolysis and down-regulating lipogenesis. Differential patterns of lipid deposition, enzymatic activities and genes' expression indicate the tissue-specific regulatory mechanism in fish.

Endoplasmic reticulum stress and dysregulation of calcium homeostasis mediate Cu-induced alteration in hepatic lipid metabolism of javelin goby Synechogobius hasta

The present study was conducted to investigate the effect of Cu exposure on endoplasmic reticulum (ER) stress and Ca(2+) homeostasis, and also explore the underlying mechanism of the ER stress and Ca(2+) homeostasis in the Cu-induced change of hepatic lipid metabolism in javelin goby Synechogobius hasta. To this end, four experiments were conducted. In experiment 1, the full-length cDNA sequences of two ER molecular chaperones [glucose-regulated protein 78 (GRP78) and calreticulin (CRT)] and three ER stress sensors [PKR-like ER kinase (PERK), inositol requiring enzyme (IRE)-1α, and activating transcription factor (ATF)-6α] cDNAs were firstly characterized from S. hasta. The predicted amino acid sequences for the S. hasta GRP78, CRT, PERK, IRE-1α and ATF-6α revealed that the proteins contained all of the structural features characteristic in other species. mRNAs of the five genes were expressed in various tissues, but their mRNA levels varied among tissues. In experiment 2, S. hasta were exposed to four waterborne Cu concentrations (control, 19μg/l, 38μg/l, and 57μg/l, respectively) for 60days. Cu exposure evoked ER stress in liver of S. hasta in a time- and concentration-course change. In experiment 3, specific inhibitors, 2-aminoethyldiphenyl borate (2-APB) and dantrolene, were used to explore whether Ca(2+) release from ER was involved in the Cu-induced ER stress change. Dantrolene and 2-APB prevented Cu-induced intracellular Ca(2+) elevation, which demonstrated the release of Ca(2+) from the ER was mediated by both RyR and IP3R. In experiment 4, a chemical chaperone, 4-phenyl butyric acid (4-PBA), was used to demonstrate whether Cu-induced alteration in lipid metabolism was suppressed through the attenuation of ER stress. Cu exposure evoked ER stress and sterol-regulator element-binding protein-1c (SREBP-1c) activation in hepatocytes of S. hasta, resulting in dysregulation of hepatic lipid metabolism. 4-PBA attenuated the Cu-induced elevation of mRNA expression of ER stress-related genes. For the first time, our study cloned GRP78, CRT, PERK, IRE-1α and ATF-6α genes in S. hasta and demonstrated their differential expression among tissues. Moreover, the study demonstrated the molecular mechanism by which ER stress might underlie the change of lipid metabolism induced by Cu in S. hasta.

De novo characterization of the liver transcriptome of javelin goby Synechogobius hasta and analysis of its transcriptomic profile following waterborne copper exposure

Previous studies have investigated the physiological responses to chronic copper (Cu) exposure in the liver of Synechogobius hasta; however, little information is available on the underlying molecular mechanisms. In an effort to better understand the mechanisms of Cu toxicity and to illuminate global gene expression patterns modulated by Cu exposure, we obtained the liver transcriptome information of S. hasta by RNA sequencing (RNA-seq) technology and also investigated the differential expression of genes following waterborne Cu exposure. Using the Illumina sequencing platform, as many as 60,217 unigenes were generated, with 815 bp of average length and 1298 bp of unigene N50 after filtering and assembly. For functional annotation analysis, 34,860, 31,526, 31,576, 25,808, 11,542, and 21,721 unigenes were annotated to the NR, NT, Swiss-Prot, KEGG, COG, and GO databases, respectively, and total annotation unigenes were 37,764. After 30 days of exposure to 55 μg Cu/l, a total of 292 and 1076 genes were significantly up- and down-regulated, respectively. By KEGG analysis, 660 had a specific pathway annotation. Subsequent bioinformatics analysis revealed that the differentially expressed genes were mainly related to lipid metabolism, immune system, apoptosis, and signal transduction, suggesting that these signaling pathways may be regulated by Cu exposure. The present study provides comprehensive sequence information for subsequent gene expression studies regarding S. hasta, and the transcriptome profiling after Cu exposure is also expected to improve our understanding of the molecular toxicology of Cu.

Fe reduced hepatic lipid deposition in Synechogobius hasta exposed to waterborne Cu

Recent evidences suggested that Fe influenced Cu metabolism in vertebrates. The present study was conducted to test the hypothesis that Fe could alleviate Cu-induced change of lipid deposition in the fish species. Synechogobius hasta were exposed to 0, 0.606 and 1.212μM Cu, in combination with 0 and 1.128μM Fe, respectively. Sampling occurred on day 28 and day 56, respectively. Growth performance, hepatic lipid deposition, Fe and Cu level, and activities and mRNA expression of enzymes and genes involved in lipid metabolism were analyzed. Fe addition in water improved survival in S. hasta exposed to the highest waterborne Cu concentration on day 56. Fe addition also increased hepatic Fe content both at day 28 and day 56, and reduced hepatic Cu content. Fe exposure tended to reduce the activities and mRNA expressions of lipogenic enzymes and genes (G6PD and FAS), and up-regulated the mRNA expression of ATGL. With the same Cu concentration, Fe addition tended to down-regulate mRNA levels of SREBP-1 and PPARγ, and up-regulate PPARα mRNA level on day 28. However, on day 56, the mRNA levels of SREBP-1, PPARγ and PPARα are very variable and not related with waterborne Fe addition. Some correlative relationship was observed between the mRNA of transcriptional factors, and the activities of enzymes and the mRNA expression of genes encoding them, implying their transcription regulation of these enzymatic genes by transcriptional factors after Fe addition. Overall, Fe addition mitigated Cu-induced changes of lipid deposition in fish by down-regulation of lipogenesis and up-regulation of lipolysis. Different response patterns of these enzyme activities and gene expressions in the liver of S. hasta following waterborne Fe exposure indicated that Fe effects on Cu-induced change of lipid metabolism are time-dependent.

Measurement of the Transverse Single-Spin Asymmetry in p^{↑}+p→W^{±}/Z^{0} at RHIC

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at sqrt[s]=500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.

Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200 GeV

We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

Antisense expression of Gossypium hirsutum UDP-glucuronate decarboxylase in Arabidopsis leads to changes in cell wall components

UDP-glucuronate decarboxylase (UDP-xylose synthase; UXS, EC 4.1.1.35) is an essential enzyme of the non-cellulosic polysaccharide biosynthetic pathway. In the present study, using transient expression of fluorescently labeled Gossypium hirsutum UXS (GhUXS3) protein in onion epidermal cells, we observed that this protein was distributed in the cytoplasm. The GhUXS3 cDNA of cotton was expressed in an antisense orientation in Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. Homozygous plants showing down-regulation of UXS were analyzed with northern blots. Compared to the untransformed control, transgenic plant showed shorter roots, earlier blossom formation, and delayed senescence. Biochemical analysis indicated that levels of rhamnose, mannose, galactose, glucose, xylose, and cellulose were reduced in some of the down-regulated antisense plants. These results suggest that GhUXS3 regulates the conversion of non-cellulosic polysaccharides and modulates their composition in plant cell walls. We also discuss a possible cellular function for GhUXS in determining the quality of cotton fibers.

Endoplasmic reticulum stress and disturbed calcium homeostasis are involved in copper-induced alteration in hepatic lipid metabolism in yellow catfish Pelteobagrus fulvidraco

The present study was conducted to investigate the effect of Cu exposure on ER stress and Ca(2+) homeostasis, and explore the underlying mechanism of the ER stress and disturbed Ca(2+) homeostasis in the regulation of hepatic lipid metabolism in yellow catfish Pelteobagrus fulvidraco. To this end, three experiments were conducted. In experiment 1, P. fulvidraco were exposed to three waterborne Cu concentrations for 56 days. Waterborne Cu exposure evoked ER stress and SREBP-1c activation and resulted in dysregulation of hepatic lipid metabolism in liver of P. fulvidraco in a time-dependent manner. In experiment 2, specific inhibitors 2-APB (IP3 receptor inhibitor) and dantrolene (RyR receptor inhibitor) were used to explore whether Ca(2+) release from ER was involved in the Cu-induced ER stress change. Dantrolene and 2-APB prevented Cu-induced intracellular Ca(2+) elevation, demonstrating that the release of Ca(2+) from the ER, mediated by both RyR and IP3R, contributed to dysregulation of lipid metabolism. In experiment 3, a chemical chaperone (PBA) was used to demonstrate whether Cu-induced alteration in lipid metabolism was suppressed through the attenuation of ER stress. PBA attenuated the Cu-induced elevation of mRNA expression of SREBP-1c, SCAP, ACC, FAS, GRP78/BiP, GRP94, CRT, eIF2α and XBP-1, and alleviated the Cu-induced downregulation of Insig-1. Based on these observations, these results reveal a link between ER stress and the change of lipid metabolism induced by Cu, which will help to understand the Cu-induced toxicity on cellular and molecular level, and provide some novel insights into the regulation of lipid metabolism in fish.

JAK and STAT members of yellow catfish Pelteobagrus fulvidraco and their roles in leptin affecting lipid metabolism

The present study clones and characterizes the full-length cDNA sequences of members in JAK-STAT pathway, explores their mRNA tissue expression and the biological role in leptin influencing lipid metabolism in yellow catfish Pelteobagrus fulvidraco. Full-length cDNA sequences of five JAKs and seven STAT members, including some splicing variants, were obtained from yellow catfish. Compared to mammals, more members of the JAKs and STATs family were found in yellow catfish, which provided evidence that the JAK and STAT family members had arisen by the whole genome duplications during vertebrate evolution. All of these members were widely expressed across the eleven tissues (liver, white muscle, spleen, brain, gill, mesenteric fat, anterior intestine, heart, mid-kidney, testis and ovary) but at the variable levels. Intraperitoneal injection in vivo and incubation in vitro of recombinant human leptin changed triglyceride content and mRNA expression of several JAKs and STATs members, and genes involved in lipid metabolism. AG490, a specific inhibitor of JAK2-STAT pathway, partially reversed leptin-induced effects, indicating that the JAK2a/b-STAT3 pathway exerts main regulating actions of leptin on lipid metabolism at transcriptional level. Meanwhile, the different splicing variants were differentially regulated by leptin incubation. Thus, our data suggest that leptin activated the JAK/STAT pathway and increases the expression of target genes, which partially accounts for the leptin-induced changes in lipid metabolism in yellow catfish.

Cloning, mRNA expression and transcriptional regulation of five retinoid X receptor subtypes in yellow catfish Pelteobagrus fulvidraco by insulin

Retinoid X receptors (RXRs) are members of the nuclear receptor superfamily and mediate development, reproduction, homeostasis and cell differentiation processes in vertebrates. In this study, full-length cDNA sequences of five rxr subtypes from yellow catfish Pelteobagrus fulvidraco were cloned. Their mRNA expression patterns in different tissues and transcriptional regulation by insulin were determined. Five P. fulvidraco rxr (Pf-rxr) subtypes differed in the length of cDNA sequence and the open reading frame, but shared the similar domain structures as in typical nuclear receptors. Phylogenetic analysis revealed that the five Pf-rxr subtypes were paralogous genes, and that Pf-rxrβa and Pf-rxrβb had arisen during a teleost-specific genome duplication event. Five subtypes of Pf-rxr were detected in all the tested tissues. Overlapping and distinct expression patterns were found for different Pf-rxr subtypes, suggesting functional redundancy and divergence of these duplicates. Intraperitoneal insulin injection and incubation reduced the mRNA expression of Pf-rxrgb, but not other subtypes, in the liver and hepatocytes of P. fulvidraco, respectively, suggesting that Pf-rxrgb is the dominant rxr subtype involved in the insulin signaling pathway in P. fulvidraco.

Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in p^{↑}+p at sqrt[s]=200 GeV

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in p^{↑}+p collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of 5 standard deviations at high transverse momenta, at high pseudorapidities η>0.5, and for pair masses around the mass of the ρ meson. This is the first direct transversity measurement in p+p collisions.

Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC

Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200 GeV

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

Effects of insulin and its related signaling pathways on lipid metabolism in the yellow catfish Pelteobagrus fulvidraco

The influence of insulin on hepatic metabolism in fish is not well understood. The present study was therefore conducted to investigate the effects of insulin on lipid metabolism, and the related signaling pathways, in the yellow catfish Pelteobagrus fulvidraco. Hepatic lipid and intracellular triglyceride (TG) content, the activity and expression levels of several enzymes and the mRNA expression of transcription factors (PPARα and PPARγ) involved in lipid metabolism were determined. Troglitazone, GW6471, fenofibrate and wortmannin were used to explore the signaling pathways by which insulin influences lipid metabolism. Insulin tended to increase hepatic lipid accumulation, the activity of lipogenic enzymes (6PGD, G6PD, ME, ICDH and FAS) and mRNA levels of FAS, G6PD, 6PGD, CPT IA and PPARγ, but down-regulated PPARα mRNA level. The insulin-induced effect could be stimulated by the specific PPARγ activator troglitazone or reversed by the PI3 kinase/Akt inhibitor wortmannin, demonstrating that signaling pathways of PPARγ and PI3 kinase/Akt were involved in the insulin-induced alteration of lipid metabolism. The specific PPARα pathway activator fenofibrate reduced insulin-induced TG accumulation, down-regulated the mRNA levels of FAS, G6PD and 6PGD, and up-regulated mRNA levels of CPT IA, PPARα and PPARγ. The specific PPARα pathway inhibitor GW6471 reduced insulin-induced changes in the expression of all the tested genes, indicating that PPARα mediated the insulin-induced changes of lipid metabolism. The present results contribute new knowledge on the regulatory role of insulin in hepatic metabolism in fish.

Different effect of dietborne and waterborne Zn exposure on lipid deposition and metabolism in juvenile yellow catfish Pelteobagrus fulvidraco

Juvenile yellow catfish Pelteobagrus fulvidraco were exposed to 0.04 or 0.35 mg l(-1) waterborne Zn, 27.25 or 213.84 mg kg(-1) dietary Zn, singly or in combination for 42 days. Growth and lipid metabolism in juvenile yellow catfish were investigated. Growth and survival were significantly inhibited by single waterborne Zn exposure but not by dietary Zn exposure. Dietary Zn addition reduced but waterborne Zn exposure increased hepatic lipid content. In contrast, muscle lipid content was reduced by waterborne Zn exposure but not by dietborne Zn exposure. The single exposure also affected several lipogenic enzymatic activities and expression of genes (in this article gene expression is taken synonymous to mRNA expression) related to lipogenesis and lipolysis. Pearson correlations among lipid content, enzymatic activities and mRNA expression levels were also observed, suggesting that changes at molecular and enzymatic levels may underlie the patterns of lipid metabolism and accordingly affect lipid deposition. For the first time, our study demonstrates the differential effect of different Zn exposure pathways on lipid metabolism at the molecular level in fish, indicating that the exposure route is critical to lipid deposition and metabolism.

Peroxisome proliferator-activated receptor gamma (PPARγ) in yellow catfish Pelteobagrus fulvidraco: molecular characterization, mRNA expression and transcriptional regulation by insulin in vivo and in vitro

Peroxisome proliferator-activated receptor gamma (PPARγ) is ligand-inducible transcription factor and has important roles in lipid metabolism, cell proliferation and inflammation. In the present study, yellow catfish Pelteobagrus fulvidraco PPARγ cDNA was isolated from liver by RT-PCR and RACE, and its molecular characterization and transcriptional regulation by insulin in vivo and in vitro were determined. The generation of PPARγ1 and PPARγ2 was due to alternative promoter of PPARγ gene. PPARγ1 and PPARγ2 mRNA covered 2426 bp and 2537 bp, respectively, with an open reading frame (ORF) of 1584 bp encoding 527 amino acid residues. Yellow catfish PPARγ gene was organized in a manner similar to that of their mammalian homologs, implying a modular organization of the protein's domains. A comparison between the yellow catfish PPARγ amino acid sequence and the correspondent sequences of several other species revealed the identity of 55-76.2%. Two PPARγ transcripts (PPARγ1 and PPARγ2) mRNAs were expressed in a wide range of tissues, but the abundance of each PPARγ mRNA showed the tissue- and developmental stage-dependent expression patterns. Intraperitoneal injection of insulin in vivo significantly stimulated the mRNA expression of total PPARγ and PPARγ1, but not PPARγ2 in the liver of yellow catfish. In contrast, incubation of hepatocytes with insulin in vitro increased the mRNA levels of PPARγ1, PPARγ2 and total PPARγ. To our knowledge, for the first time, the present study provides evidence that PPARγ1 and PPARγ2 are differentially expressed with and among tissues during different developmental stages and also regulated by insulin both in vivo and in vitro, which serves to increase our understanding on PPARγ physiological function in fish.

Effects of recombinant human leptin administration on hepatic lipid metabolism in yellow catfish Pelteobagrus fulvidraco: in vivo and in vitro studies

The present study was conducted to investigate the effects and mechanism of leptin influencing lipid metabolism in yellow catfish Pelteobagrus fulvidraco. To this end, hepatic lipid (in vivo experiment) and intracellular triglyceride (TG) (in vitro experiment) content, the activities and/or expression level of several enzymes (CPT-1, 6PGD, G6PD, FAS, ME and ICDH) as well as the mRNA expression of transcription factors (PPARα, PPARγ and SREBP-1) involved in lipid metabolism were determined. Using the primary hepatocytes of yellow catfish, specific inhibitors AG490 (JAK-STAT inhibitor) and wortmannin (IRS-PI3K inhibitor) were used to explore the signaling pathways of leptin effects on lipid metabolism. Intraperitoneal injection of recombinant human leptin (rt-hLEP) significantly reduced hepatic lipid content, activities of lipogenic enzymes (6PGD, G6PD, ME, ICDH and FAS) as well as mRNA levels of 6PGD, G6PD, FAS, PPARγ and SREBP-1 genes, but up-regulated activity and mRNA level of CPT-1 and PPARα. Using primary hepatocytes, rt-hLEP incubation also reduced intracellular TG content, mRNA levels of G6PD and PPARγ genes, but enhanced mRNA levels of PPARα, CPT-1 and SREBP-1. Leptin-induced effects could partially be reversed by specific inhibitors AG490, suggesting that JAK-STAT signaling pathways played important roles in the process of leptin-induced changes in lipid metabolism. Wortmannin significantly suppressed the decrease of TG content induced by leptin, reflecting that IRS-PI3K was involved in the leptin-mediate changes as well. To our knowledge, the present study provides, for the first time, evidence that rt-hLEP can increase lipolysis and reduce lipogenesis at the both enzymatic and molecular levels in fish with the combination of in vivo with in vitro studies, which serves to increase our understanding into the roles and mechanisms of leptin regulating lipid metabolism in fish.

ΛΛ Correlation function in Au+Au collisions at √[S(NN)]=200 GeV

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Observation of D0 meson nuclear modifications in Au+Au collisions at sqrt[s(NN)] = 200 GeV

We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

Time-dependent effects of waterborne copper exposure influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta and their mechanism

The present study was conducted to determine the time-course of waterborne chronic copper (Cu) exposure effects influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta and their mechanisms. S. hasta were exposed to four waterborne Cu concentrations (2 (control), 18, 38 and 55 μg Cu/l) for 60 days. Sampling occurred on day 30 and day 60, respectively. Survival decreased and hepatic Cu content increased with increasing Cu levels. On day 30, Cu exposure increased hepatic lipid content, viscerosomatic index (VSI) and hepatosomatic index (HSI), and activities of lipogenic enzymes (6PGD, G6PD, ME, ICDH and FAS) as well as the mRNA levels of 6PGD, G6PD, ME, FAS, ACCα, LPL, PPARγ and SREBP-1 in the liver. However, the mRNA levels of ATGL, HSL and PPARα declined following Cu exposure. On day 60, Cu exposure reduced hepatic lipid content, HSI, VSI, activities of G6PD, ME, ICDH and FAS, and the mRNA expression of 6PGD, G6PD, ME, FAS and SREBP-1, but increased mRNA expression of CPT 1, HSL and PPARα. The differential Pearson correlation between transcriptional changes of genes encoding transcription factors (PPARα, PPARγ and SREBP-1), and the activities and mRNA expression of enzymes involved in lipogenesis and lipolysis were observed on day 30 and day 60, respectively. Cu exposure for 30 days induced hepatic lipid accumulation by stimulating lipogenesis and inhibiting lipolysis. However, 60-day Cu exposure reduced hepatic lipid content by inhibiting lipogenesis and stimulating lipolysis. To our knowledge, for the first time, the present study provided experimental evidence that waterborne chronic Cu exposure differentially influenced genes involved in lipogenic and lipolytic metabolic pathway and the enzymes encoded in a duration-dependent manner in fish, and provided new insight into the relationship between metal toxicity and lipid metabolism.

Hormone-sensitive lipase in yellow catfish Pelteobagrus fulvidraco: molecular characterization, mRNA tissue expression and transcriptional regulation by leptin in vivo and in vitro

Hormone-sensitive lipase (hsl) plays a pivotal role in regulation of lipolysis in mammals, but information is very scarce about its gene structure and function in fish. In this study, two distinct hsl cDNAs, designated hsl1 and hsl2, were firstly isolated and characterized from yellow catfish Pelteobagrus fulvidraco. The validated cDNAs encoding for hsl1 and hsl2 were 2739 and 2629bp in length, encoding peptides of 679 and 813 amino acid residues, respectively, and shared 57.7% amino acid identity. The phylogenetic analysis revealed that hsl1 and hsl2 derived from paralogous genes that might have arisen during a teleost-specific genome duplication event. Both hsl mRNAs were expressed in a wide range of tissues, but the abundance of each hsl mRNA showed the tissue- and developmental stage-dependent expression patterns. Intraperitoneal injection in vivo and incubation in vitro of recombinant human leptin (rb-hLEP) stimulated the mRNA expression of hsl2, but not hsl1, in the liver and hepatocytes of P. fulvidraco, respectively, suggesting that two hsl isoforms might serve different roles in lipid metabolism. To our knowledge, for the first time, the present study provides evidence that two hsl mRNAs are differentially expressed with and among tissues during different developmental stages and also differentially regulated by leptin both in vivo and in vitro, which serves to increase our understanding on hsl physiological function in fish.

Beam energy dependence of moments of the net-charge multiplicity distributions in Au+Au collisions at RHIC

We report the first measurements of the moments--mean (M), variance (σ(2)), skewness (S), and kurtosis (κ)--of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from sqrt[sNN]=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ(2)/M, Sσ, and κσ(2), with the expectations from Poisson and negative binomial distributions (NBDs). The Sσ values deviate from the Poisson baseline and are close to the NBD baseline, while the κσ(2) values tend to lie between the two. Within the present uncertainties, our data do not show nonmonotonic behavior as a function of collision energy. These measurements provide a valuable tool to extract the freeze-out parameters in heavy-ion collisions by comparing with theoretical models.

Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<x<0.2.

Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

Effects of copper and cadmium on lipogenic metabolism and metal element composition in the javelin goby (Synechogobius hasta) after single and combined exposure

The present study was performed to determine the effects of single and combined exposure of copper (Cu) and cadmium (Cd) on lipogenic metabolism and metal element composition of javelin goby Synechogobius hasta. Two hundred and forty uniform-sized S. hasta (initial mean weight 20.3 ± 0.3 g [mean ± SEM throughout]; initial body length 15.2 ± 0.2 cm) were randomly assigned to 12 fiberglass tanks (water volume 300 l) with 20 fish/tank. The fish were exposed to four treatments with different Cu and Cd concentration for 30 days, respectively: (1) control (without extra Cu and Cd addition), (2) Cu (nominal concentrations of 77 μg/l), (3) Cd (79 μg/l), and (4) Cu + Cd (Cu/Cd coexposure). Growth decreased, but hepatosomatic index, viscerosomatic index, and lipid content increased after metal exposure. Staining with Oil Red O and haematoxylin and eosin showed extensive alterations in liver of metals-exposed fish. Metal exposure influenced the accumulation of metal elements (Cu, Cd, iron, zinc, and manganese) in several tissues (muscle, gill, intestine, liver, and spleen) and increased hepatic 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, malic enzyme, isocitrate dehydrogenase, and fatty acid synthase activities. The results of the present study indicated that the changes in lipogenic metabolism and metal element compositions of fish under Cu and Cd coexposure could not be explained by synergism of the addition of the effects observed in singly Cu- or Cd-exposed fish. To our knowledge the present study, for the first time, investigated the effects of Cu and Cd coexposure on hepatic lipogenic metabolism and metal element compositions in a wide range of tissues and organs in fish, which provided new evidence for Cu and Cd interactions in fish.

Dielectron mass spectra from Au+Au collisions at √[s(NN)]=200 GeV

We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|<1) in Au+Au collisions at √[s(NN)]=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like)   GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.