Impact of Serum Chemerin Levels on Liver Functional Reserves and Platelet Counts in Patients with Hepatocellular Carcinoma

Obesity-related metabolic abnormalities, including adipokine imbalance and chronic inflammation, are involved in liver carcinogenesis. Chemerin, a novel adipokine, plays a critical role in adipogenesis, energy metabolism, and inflammation. We evaluated the impact of serum chemerin levels on liver functional reserves in hepatocellular carcinoma (HCC) patients and on the recurrence and prognosis of HCC. This study included 44 patients with any stage of HCC who underwent curative treatment at Gifu Municipal Hospital (Gifu, Japan) between 2006 and 2007. Recurrence-free survival and overall survival were estimated using the Kaplan-Meier method. Serum albumin levels (Pearson’s correlation coefficient; r = 0.3110, p = 0.0399), platelet counts (r = 0.4159, p = 0.0050), and prothrombin times (r = 0.3775, p = 0.0115) were significantly correlated with serum chemerin levels in patients with HCC, and they were inversely correlated with Child-Pugh scores (r = −0.3732, p = 0.0126), serum alanine aminotransferase levels (r = −0.3864, p = 0.0105), and total bilirubin levels (r = −0.4023, p = 0.0068). Among these variables, a multiple comparison test identified that platelet counts and total bilirubin levels were associated with serum chemerin levels (p < 0.0083). No significant correlation was found between serum chemerin levels and recurrence-free survival (p = 0.3691) or overall survival (p = 0.7916). In HCC patients, serum chemerin concentrations were correlated with liver functional reserves and platelet counts, but not with recurrence or prognosis.     

Nicotinic Acid Increases Adiponectin Secretion from Differentiated Bovine Preadipocytes through G-Protein Coupled Receptor Signaling

The transition period in dairy cows (3 weeks prepartum until 3 weeks postpartum) is associated with substantial mobilization of energy stores, which is often associated with metabolic diseases. Nicotinic acid (NA) is an antilipolytic and lipid-lowering compound used to treat dyslipidaemia in humans, and it also reduces non-esterified fatty acids in cattle. In mice the G-protein coupled receptor 109A (GPR109A) ligand NA positively affects the secretion of adiponectin, an important modulator of glucose and fat metabolism. In cattle, the corresponding data linking NA to adiponectin are missing. Our objective was to examine the effects of NA on adiponectin and AMPK protein abundance and the expression of mRNAs of related genes such as chemerin, an adipokine that enhances adiponectin secretion in vitro. Differentiated bovine adipocytes were incubated with pertussis toxin (PTX) to verify the involvement of GPR signaling, and treated with 10 or 15 µM NA for 12 or 24 h. NA increased adiponectin concentrations (p ≤ 0.001) and the mRNA abundances of GPR109A (p ≤ 0.05) and chemerin (p ≤ 0.01). Pre-incubation with PTX reduced the adiponectin response to NA (p ≤ 0.001). The NA-stimulated secretion of adiponectin and the mRNA expression of chemerin in the bovine adipocytes were suggestive of GPR signaling-dependent improved insulin sensitivity and/or adipocyte metabolism in dairy cows.     

Effect of Thyrotropin on Osteopontin,Integrin αvβ3, and VCAM-1 in the Endothelium via Activation of Akt

Numerous epidemiological studies have shown that subclinical hypothyroidism (SCH) can impair endothelial function and cause dyslipidemia. Studies have evaluated the effects of thyroid stimulating hormone (TSH) on endothelial cells, but the mechanism underlying the proatherosclerotic effect of increased TSH levels remains unclear. In the present study, SCH rat models were established in thyroidectomized Wistar rats that were given l-T₄ daily. The results showed that in vivo, the expression of osteopontin (OPN) vascular cell adhesion molecule (VCAM-1), and levels of integrin α_vβ₃ in the aortic tissue in SCH and Hypothyroidism (CH) groups was higher than in the control group. However, the effect in the SCH group was higher than in the CH group. In vitro, results showed that different concentration and time gradients of TSH stimulation could increase the expression of OPN, VCAM-1, and integrin α_vβ₃, and this was accompanied by extracellular signal regulated kinase 1/2 (Erk1/2) and Akt activation in human umbilical vein endothelial cells (HUVECs). TSH induced elevation of these proatherosclerotic factors was partially suppressed by a specific Akt inhibitor but not by a specific Erk inhibitor. Findings suggested that the endothelial dysfunction caused by SCH was related to increased proatherosclerotic factors induced by TSH via Akt activation.     

High oleic acid oil suppresses lung tumorigenesis in mice through the modulation of extracellular signal-regulated kinase cascade

This study was undertaken to estimate the effect of dietary high oleic acid oil (OA) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in mice. Diet containing 10% oil was fed to mice through experimental periods. On day 30 after NNK injection (100 mg/kg body weight, i.p.), the treatment increased the level of prostaglandin E₂ (PGE₂) as well as proliferating cell nuclear antigen, a marker of cell proliferation in a high linoleic acid oil (LA)-fed group but not in an OA-fed group. The NNK treatment also induced the activation of an extracellular signal-regulated kinase (Erk) cascade (Erk, Mek and Raf-1) in an LA-fed group. On the other hand, OA feeding abolished the NNK-induced activation of the Erk cascade. In conjugation with these events, OA feeding reduced lung tumor incidence and tumor multiplicity (percentage of mice with tumors) in mice compared with LA feeding at the 20th experimental week. These results suggest that OA suppresses lung tumorigenesis and that this suppression is correlated with the inhibition of PGE₂ production and inactivation of the Erk cascade.     

SP600125 Induces Src and Type I IGF Receptor Phosphorylation Independent of JNK

c-Jun N-terminal kinases (JNK) are members of the mitogen-activated protein kinase (MAPK) family that have important roles in signal transduction. The small molecule SP600125 is widely used in biochemical studies as a JNK inhibitor. However, recent studies indicate that SP600125 may also act independent of JNK. Here, we report that SP600125 can induce Src, type I insulin-like growth factor receptor (IGF-IR), Akt and Erk1/2 phosphorylation. Notably, these effects are independent of its inhibition of JNK. Inhibition of Src abrogates the stimulation of IGF-IR, Akt and Erk1/2 phosphorylation. IGF-IR knockdown blunts the induction of both Akt and Erk1/2 phosphorylation by SP600125. Moreover, combination of SP600125 and the Src inhibitor saracatinib synergistically inhibits cell proliferation. We conclude that SP600125 can activate Src-IGF-IR-Akt/Erk1/2 signaling pathways independent of JNK.     

Chemokine-like Receptor 1 in Brain of Spontaneously Hypertensive Rats Mediates Systemic Hypertension

Adipocytokine chemerin is a biologically active molecule secreted from adipose tissue. Chemerin elicits a variety of functions via chemokine-like receptor 1 (CMKLR1). The cardiovascular center in brain that regulates blood pressure (BP) is involved in pathophysiology of systemic hypertension. Thus, we explored the roles of brain chemerin/CMKLR1 on regulation of BP in spontaneously hypertensive rats (SHR). For this aim, we examined effects of intracerebroventricular (i.c.v.) injection of CMKLR1 small interfering (si)RNA on both systemic BP as measured by tail cuff system and protein expression in paraventricular nucleus (PVN) of SHR as determined by Western blotting. We also examined both central and peripheral protein expression of chemerin by Western blotting. Systolic BP of SHR but not normotensive Wistar Kyoto rats (WKY) was decreased by CMKLR1 siRNA. The decrease of BP by CMKLR1 siRNA persisted for 3 days. Protein expression of CMKLR1 in PVN of SHR tended to be increased compared with WKY, which was suppressed by CMKLR1 siRNA. Protein expression of chemerin in brain, peripheral plasma, and adipose tissue was not different between WKY and SHR. In summary, we for the first time revealed that the increased protein expression of CMKLR1 in PVN is at least partly responsible for systemic hypertension in SHR.     

Detection of the 15-acetate of prostaglandin E2 methyl ester as a prominent component of the prostaglandins in the gorgonian coral Plexaura homomalla

15R-Prostaglandin E₂ (PGE₂) methyl ester 15-acetate (1) was isolated from the R-variety of the Caribbean sea whip coral, Plexaura homomalla collected in the Florida Keys. It was present in coral samples from separate collections in 2–10% of the abundance of the major prostaglandin component, PGA₂ methyl ester 15-acetate. The structure of 1 was assigned based on one- and two-dimensional ¹H NMR, HPLC, and LC-MS analyses. A sample of the S-variety of P. homomalla was found to contain a similar abundance of the corresponding 15S product, prostaglandin E₂ methyl ester 15-acetate. The significance of PGE acetylation is discussed in relation to the proposed mechanism of PGA synthesis in the coral.     

Enhancing Effect of Calix[4]arene Amide Derivatives on Lipase Performance in Enantioselective Hydrolysis of Racemic Arylpropionic Acid Methyl Esters

Calix[4]arene amide derivatives were employed as new additives within the sol-gel encapsulation of lipase from Candida rugosa (CRL) to improve its catalytic properties. Evaluation of catalytic activity of the encapsulated lipases was acheived by enantioselective hydrolysis of both racemates, Naproxen methyl ester and 2-phenoxypropionic acid methyl ester, in aqueous buffer solution/isooctane reaction system. Results show that enantioselectivity was improved by using calix[4]arene amide derivatives-based encapsulated lipases. The reaction of naproxen methyl ester resulted in 47.6% conversion (x) in 24 h with 88.9% enantiomeric excess of substrate (ee_s), analogous to an enantioselectivity (E) value of 297 (E = 137 for the encapsulated free enzyme). The conversion of 2-phenoxypropionic acid methyl ester, obtained was 48.4% with E value of 327, enantiomeric excess of substrate (ee_s) of 92% for the reaction time of 1 h (E = 211 for the encapsulated free enzyme).     

The Two Classic Pb2+-Selective DNAzymes Are Related: Rational Evolution for Understanding Metal Selectivity

In 1994, the first DNAzyme named GR5 was reported, which specifically requires Pb²⁺ for its RNA cleavage activity. Three years later, the 8-17 DNAzyme was isolated. The 8-17 DNAzyme and the related 17E DNAzyme are also most active with Pb²⁺, although other divalent metals can work as well. GR5 and 17E have the same substrate sequence, and their catalytic loops in the enzyme strands also have a few similar and conserved nucleotides. Considering these, we hypothesized that 17E might be a special form of GR5. To test this hypothesis, we performed systematic rational evolution experiments to gradually mutate GR5 toward 17E. By using the activity ratio in the presence of Pb²⁺ and Mg²⁺ for defining these two DNAzymes, the critical nucleotide was identified to be T₁₂ in 17E for metal specificity. In addition, G₉ in GR5 is a position not found in most 17E or 8-17 DNAzymes, and G₉ needs to be added to rescue GR5 activity if T₁₂ becomes a cytosine. This study highlights the links between these two classic and widely used DNAzymes, and offers new insight into the sequence–activity relationship related to metal selectivity.     

Human Adipose Tissue Conditioned Media from Lean Subjects Is Protective against H2O2 Induced Neurotoxicity in Human SH-SY5Y Neuronal Cells

Adipose tissue secretes numerous hormone-like factors, which are known as adipokines. Adipokine receptors have been identified in the central nervous system but the potential role of adipokine signaling in neuroprotection is unclear. The aim of this study is to determine (1) Whether adipokines secreted from cultured adipose tissue of lean humans is protective against oxidative stress-induced neurotoxicity in human SH-SY5Y neuronal cells; and (2) To explore potential signaling pathways involved in these processes. Adipose tissue conditioned media (ATCM) from healthy lean subjects completely prevented H₂O₂ induced neurotoxicity, while this effect is lost after heating ATCM. ATCM activated the phosphorylation of ERK1/2, JNK and Akt at serine 308 in SH-SY5Y cells. PD98059 (25 µM), SP600125 (5 µM) and LY29400 (20 µM) partially blocked the protective effects of ATCM against H₂O₂ induced neurotoxicity. Findings demonstrate that heat-sensitive factors secreted from human adipose tissue of lean subjects are protective against H₂O₂ induced neurotoxicity and ERK1/2, JNK, and PI3K signaling pathways are involved in these processes. In conclusion, this study demonstrates preliminary but encouraging data to further support that adipose tissue secreted factors from lean human subjects might possess neuroprotective properties and unravel the specific roles of ERK1/2, JNK and PI3K in these processes.     

Enzymatically-mediated uranium accumulation and uranium recovery using a Citrobacter sp. Immobilised as a biofilm within a plug-flow reactor

Biofilm-immobilised Citrobacter sp. removed uranyl ion from flows supplemented with glycerol 2-phosphate. The metal uptake mechanism was mediated by the activity of a cell-surface bound phosphatase that precipitated liberated inorganic phosphate with uranyl ion as HUO₂PO₄·4H₂O at the bacterial surface. A modified integrated form of the Michaelis–Menten equation is proposed to describe the removal of metal ion by a columnar bioreactor, where the efficiency of metal removal is semi-quantitatively related to the input flow rate, the total enzyme loading (E₀) and the bioreactor activity. With biofilm-immobilised bacteria, E₀ was further divisible (split) into subparameters of phosphatase titre per bacterium and total biomass surface area. Varying the split E₀ and the reaction temperature modified the bioreactor performance. The immobilised bacteria retained high metal loads without loss in steady-state activity. Accumulated metal was recovered as a concentrated solution.     

Insect sex pheromones: Evaporation rates of alcohols and acetates from natural rubber septa

The half-lives (t _1/2) of alcohol sex pheromones, 1-alkanols, acetate sex pheromones, and an epoxide (disparlure) were determined on natural rubber septa. Thet _1/2 values for the homologous alcohols from decanol to heptadecanol increased regularly from 2.2 to 1117 days, but thet _1/2 of octadecanol was 609 days. Thet _1/2 values of (Z)7-, (E)7-, and (Z)9-tetradecen-1-ol acetates were 154, 168, and 199 days, respectively, whereas those of five other tested 14-carbon acetates ranged from 310 to 350 days. The dependence oft _1/2 values on chain length and double-bond position is consistent with the hypothesis that molecular size is an important variable affectingt _1/2 values. Also, in accordance with the hypothesis, when aZ-alkenyl compound has a much shortert _1/2 than the corresponding saturated compound, thet _1/2 values of theZ compound and itsE isomer may be quite different. Thus, (E)-9-tetradecen-l-ol acetate had at _1/2 of 331 days. Thet _1/2 of disparlure was 180 days. The effect of thecis-7,8 epoxide group is apparently similar to that of the olefin group in lowering thet _1/2 below the value that would be expected solely on the basis of chain length.This paper reports the results of research only. Mention of a commercial product in this paper does not constitute a recommendation by the U.S. Department of Agriculture.     

介孔二氧化钛固载γ-谷氨酰转肽酶的制备及性质

γ-谷氨酰转肽酶（GGT）在临床诊断和生物催化方面具有重要的应用价值。本文以介孔氧化钛晶须为载体进行GGT的固定化,考察了载体结构特性、吸附时间和给酶量对固定化效果的影响,并对固定化酶的催化特性及其稳定性进行了研究。结果显示,以最可几孔径为30 nm的介孔TiO₂为载体,载体载酶量可达5.07mg·g^-1。在给酶量为18.99 U·g^-1时,经室温吸附2.5 h,固定化酶活性回收率可达73.05%。固定化酶的pH稳定性和热稳定性均显著优于游离酶,在4℃下保温贮藏60 d、转化22个批次后,固定化酶活力仍可保持初始值的71.30%。经测定,游离酶和固定化酶的米氏常数K_m分别为0.79 mmol·L^-1和1.05 mmol·L^-1,酰基化反应活化能分别为13.59 kJ·mol^-1和15.42 kJ·mol^-1;固定化GGT的失活反应活化能E_d为92.80 kJ·mol-1,相比于游离酶（49.61 kJ·mol^-1）有明显的增加。     

Prostaglandin and acyl chain effects on glutamate dehydrogenase activity

Prostaglandins A₁ (PGA₁), A₂, B₁, B₂, E₁, E₂, F_1α, F_2α, and 19 esterified natural fatty acids were tested as effectors of beef liver glutamate dehydrogenase (L-glutamate: NAD(P)⁺, oxidoreductase [deaminating], EC 1.4.1.3). All prostaglandins tested are found to activate the enzyme initially, but only PGA₂>PGB₂≥PGA₁ cause a subsequent time-dependent loss (not inhibition) of NADH oxidation activity. Both PGA₁ and PGA₂ desensitize glutamate dehydrogenase to allosteric activation by ADP, whereas PGA₂ and PGB₂ desensitize to allosteric inactivation by GTP. Preincubation of enzyme with diethylstilbestrol prevents the initial activation by the PG. Of the methyl esters, only prostaglandin precursors inactivated the enzyme. Simultaneous desensitization to the ADP and GTP allosteric effects resulted. Multiple esterification to glycerol or phospholipids enhanced the action of linoleoyl and diminished the action of linolenoyl chains. Preincubation of the PGA with glutathione or cysteine prevents the inactivation; i.e., the sulfhydryl binding region of the prostaglandin must be free for enzyme to be inactivated. Sulfhydryl reagents also protect the enzyme from the effects of the unsaturated acyl chains, and pHMB mimics acyl protection against GTP allosteric inactivation. Where the lipid effector is active against sulfhydryl groups, the desensitizations to the ADP and GTP allosteric effectors are reciprocal. The initial activation, subsequent inactivation and desensitization to ADP and GTP are all characteristic of binding in the estrogen-specific effector site, suggesting this site as the target for PG and acyl action. In the PGA₂ activation, the effect is found to be amplified by the cooperativity of the enzyme at 1 PG molecule/6 molecules of GDH. We conclude from the action of the PG and structural analogs that the initial activation of glutamate dehydrogenase is caused by α,β-unsaturated monoketo cyclopental structures. GTP inhibition is blocked primarily by diketo structures which eventually inactivate the enzyme. ADP activation is blocked by sulfhydryl binding of the unsaturated cyclopental keto structure of the PG. Appearance of a 270 nm absorbance simultaneous to the acyl effects on the enzyme suggests that conjugated unsaturations are responsible for the precursor's qualitatively similar action to that of the PG.     

A SAXS study of the structure of gels formed by mixtures of polyoxyalkylene triblock copolymers

Small‐angle X‐ray scattering was used to characterise aqueous micellar gels of triblock copolymers E₁₃₇S₁₈E₁₃₇, E₈₂S₉E₈₂, E₇₆S₅E₇₆, E₆₂P₃₉E₆₂, and of two mixtures: E₁₃₇S₁₈E₁₃₇ and E₆₂P₃₉E₆₂ (Mix 1) and E₈₂S₉E₈₂ and E₆₂P₃₉E₆₂ (Mix 2), each 50/50 wt%. E = oxyethylene, CH₂CH₂O; S = oxyphenylethylene, OCH₂CH(C₆H₅); and P = oxypropylene, OCH₂CH(CH₃). Within the concentration and temperature ranges investigated (30–40 wt% copolymer, 20–80 °C), spherical micelles of copolymers E₁₃₇S₁₈E₁₃₇, E₈₂S₉E₈₂ and E₆₂P₃₉E₆₂ packed into body‐centred cubic (BCC) structures. Gels of E₇₆S₅E₇₆ were stable only at high concentrations and low temperatures, and a 70 wt% copolymer solution at T = 30 °C formed a hexagonal gel consistent with cylindrical micelles. It is likely that the mixed copolymers would form two distributions of micelles, and more complex structures were expected. However, gels of Mix 2 had well‐ordered BCC structures, while the less ordered gels of Mix 1 were also best characterised as BCC. Copyright © 2006 Society of Chemical Industry     

StAR Overexpression Decreases Serum and Tissue Lipids in Apolipoprotein E-deficient Mice

Cholesterol metabolism as initiated by mitochondrial sterol 27-hydroxylase (CYP27A1) is a ubiquitous pathway capable of synthesizing multiple key regulatory oxysterols involved in lipid homeostasis. Previously we have shown that the regulation of its activities within hepatocytes is highly controlled by the rate of mitochondrial cholesterol delivery. In the present study, we hypothesized that increasing expression of the mitochondrial cholesterol delivery protein, steroidogenic acute regulatory protein (StAR), is able to lower lipid accumulation in liver, aortic wall, as well as in serum in a well-documented animal model, apolipoprotein E-deficient (apoE^−/−) mice. ApoE^−/− mice, characterized by increased serum, liver, and endothelial cholesterol and triglyceride levels by 3 months of age, were infected with recombinant cytomegalovirus (CMV)-StAR adenovirus to increase StAR protein expression. Six days following infection, serum total cholesterol and triglycerides had decreased 19 and 30% (P < 0.01), respectively, with a compensatory 40% (P < 0.01) increase in serum HDL-cholesterol in increased StAR expressing mice as compared to controls (no or control virus). Histologic and biochemical analysis of the liver demonstrated not only a dramatic decrease in cholesterol (↓25%; P < 0.01), but an even more marked decrease in triglyceride (↓56%; P < 0.01) content. En bloc Sudan IV staining of the aorta revealed a >80% (P < 0.01) decrease in neutral lipid staining. This study demonstrates for the first time a possible therapeutic role of the CYP27A1-initiated pathway in the treatment of dyslipidemias.     

Stable Binding of Full-Length Chemerin Is Driven by Negative Charges in the CMKLR1 N Terminus

The adipokine chemerin is the endogenous ligand of the chemokine-like receptor 1 (CMKLR1), a member of the family of G protein-coupled receptors (GPCRs). This protein ligand plays an important role in obesity and inflammatory processes. Stable receptor–ligand interactions are highly relevant for its different physiological effects such as the migration of immune cells towards sites of inflammation. Here, we demonstrate that negative charges in the CMKLR1 N terminus are involved in the formation of strong contacts with a specific positively charged patch at the surface of full-length chemerin, which is absent in the short nonapeptide agonist chemerin-9, thus explaining its reduced affinity. Using receptor chimera of G protein-coupled receptor 1 (GPR1) and CMKLR1, we were able to identify the residues of this interaction and its relevance for stable full-length chemerin binding. This could help to develop more potent ligands for the treatment of inflammation-related diseases.