Variation in alpha-L-fucosidase properties among 28 inbred mouse strains: Six strains have high enzyme activity and heat-stabile enzyme with a variant pH-activity curve; twenty-two strains have low activity and heat-labile enzyme

Alpha-L-fucosidase in tissues of 28 inbred mouse strains varied with respect to three properties: high or low heat stability, a pH-activity curve with high or low relative activity at pH 2.8, and high or low activity. Alpha-L-fucosidase from six strains (A/J, BDP/J, LP/J, P/J, SEA/GNJ, and 129/J) had high heat stability, high pH 2.8 relative activity, and high activity, whereas the other 22 strains all had low heat stability, low pH 2.8 relative activity, and low activity. The heat-stability difference was seen in all organs tested (brain, liver, kidney, spleen, heart, skeletal muscle, lung, and testis) for two heat-stabile strains (P/J and 129/J) and four heat-labile strains (C57 BL/6J, C3H/HeJ, DBA/2J, and BALB/cJ) studied in detail. The findings suggested that two structural variants of alpha-L-fucosidase, probably genetically determined, exist in these 28 inbred mouse strains, although the presence of linkage disequilibrium between alleles of tightly linked structural and regulatory genes could not be excluded.This work was supported by grants from the National Institutes of Health (NS-15281 and NS-11766), the Muscular Dystrophy Association (H. Houston Merritt Clinical Center for Muscular Dystrophy and Related Diseases), the March of Dimes Birth Defects Foundation, and a generous gift from the Alexander Rapaport Foundation.     

Different Sensitivity of Complement to Salmonella typhimurium Accounts for the Difference in Natural Resistance to Murine Typhoid between A/J and C57BL/6 Mice

The difference in natural resistance to Salmonella typhimurium between S. typhimurium-resistant A/J mice and S. typhimurium-susceptible C57BL/6 mice was analyzed. In both strains, the growth of S. typhimurium was controlled in the spleen until 48 hr of infection, while serum C3b levels were increased in A/J mice immediately after infection but not in C57BL/6 mice. Incubation of A/J mouse serum with S. typhimurium or its lipopolysaccharide (LPS) generated sufficient amounts of C3b, but that of C57BL/6 mouse serum with them did not. A/J macrophages had higher intracellular killing activity in vitro than did C57BL/6 cells against S. typhimurium pre-opsonized with each corresponding fresh serum. However, the cells from both mice exhibited a similar level of killing activity against S. typhimurium pre-opsonized with fresh A/J serum or rabbit complement. The resistance of C57BL/6 mice was significantly increased by opsonizing S. typhimurium with fresh A/J serum or rabbit complement before inoculation. The serum level of interferon-γ (IFN-γ) in A/J mice was 2.7 times as high as in C57BL/6 mice at 48 hr post-infection. Recombinant murine IFN-γ enhanced the intracellular killing activity of macrophages from both mice when S. typhimurium was pre-opsonized with fresh A/J serum but not with fresh C57BL/6 serum. These findings suggest that A/J macrophages exhibit maximal killing activity against A/J serum-opsonized S. typhimurium in vivo when the cells are activated with IFN-γ. Therefore, the rapid and sufficient activation of complement by Salmonella LPS may render A/J mice more resistant against murine typhoid.     

Reciprocal Hemizygosity Analysis of Mouse Hepatic Lipase Reveals Influence on Obesity

Objectives: We previously demonstrated coincident quantitative trait loci (QTLs) for percentage body fat, plasma hepatic lipase (HL) activity, and plasma cholesterol on mouse chromosome 7. In the present study, we investigated whether hepatic lipase (Lipc) is an obesity gene, whether Lipc interacts with an unknown gene on chromosome 7, and how HL activity is linked to the chromosome 7 locus. Research Methods and Procedures: BSB mice are a model of complex obesity due to interactions among genes from C57BL/6J and Mus spretus (SPRET) in (C57BL/6J × SPRET) × C57BL/6J backcross mice. Five crosses tested the impact on obesity of combinations of inactive (knockout) and wild‐type Lipc alleles from C57BL/6J or SPRET in a reciprocal hemizygosity analysis. Results: The combined data from this allelic series suggest that Lipc alleles, and not alleles from a gene linked to Lipc, influence obesity. No interaction between Lipc and chromosome 7 was demonstrated. We confirmed the chromosome 7 QTLs for obesity, HL activity, and cholesterol. Because obesity and HL activity are not consistently associated in the BSB model, linkage of HL activity to chromosome 7 is not secondary to obesity per se. We also report, for the first time to our knowledge, a QTL in mammals for food intake. Discussion: This use of reciprocal hemizygosity analysis in mammals, which, to our knowledge, is the first reported, reveals its power to detect previously unknown effects of Lipc on obesity.     

Heterogeneity in the biochemical characteristics of red blood cell hypoxanthine-guanine phosphoribosyl transferase from two unrelated patients with the lesch-nyhan syndrome

HGPRT from patient M. Y. (enzyme level 0.1% normal) retained a normal apparent K _m both for PRPP and for hypoxanthine and was inhibited by its product. The enzyme was, however, unstable at 50 C (43% of activity remaining after 1 hr) when compared with normal controls (81% of activity retained). The enzyme from patient J.D. (enzyme level 0.005% normal) was also unstable (32% of activity retained). Unlike for M.Y., however, all the other characteristics studied were also altered. The enzyme activity was enhanced rather than inhibited by its product (IMP), and the apparent K _m (hypoxanthine) could not be calculated due to the sigmoid nature of the curve. Obviously, there is marked heterogeneity in the nature of the biochemical lesion responsible for the Lesch-Nyhan syndrome in these patients, and this is discussed.This research was supported by the Medical Research Council of Canada (a Postdoctoral Fellowship to B.J.R. and Grant No. MA-4061 to J.L.H.) and by the Children's Hospital Research Foundation.     

Control of liver tyrosine aminotransferase expression: Enzyme regulatory studies on inbred strains and mutant mice

Studies on the genetic mechanisms in control of mouse liver tyrosine aminotransferase expression were of three general types: (1) studies on strain variance in endogenous enzyme activity and of various factors affecting the basal enzyme level, (2) purification of the enzyme and studies of its properties, and (3) studies of strain variance in enzyme regulation dealing primarily with glucocorticoid induction and with the starvation-induced enzyme adaptation. Tyrosine aminotransferase (l-tyrosine: 2-oxoglutarate aminotransferase, E.C. 2.6.1.5) was purified 400 to 600-fold from livers of C57BL/6J and DBA/2J inbred mice. Several of the properties of the mouse liver enzyme were similar to those known for the rat liver enzyme although the apparent K _m (l-tyrosine) was lower, calculated at 6.25×10^–4 M. Disc gel electrophoresis of the enzyme from 105,000 g supernatant fluid after induction by hydrocortisone indicated three bands of enzyme activity with strain variance in electrophoretic mobility between the C57BL/6J and DBA/2J mice. The administration of glucose to fasting C57BL/6J mice repressed the starvation-induced increase in enzyme activity, but did not prevent the hydrocortisone induction of enzyme activity. DEAE-cellulose chromatography of purified enzyme from fasting DBA/2J and C57BL/6J mice which had been labeled in vivo with C ¹⁴ -l-leucine revealed strain differences in the elution patterns for both enzyme activity and radioactivity. Two peaks of enzyme activity were detected in the enzyme preparations from fasting mice. The marked strain variance in the enzyme activity and the quantity of radioactivity associated with the first enzyme peak may indicate differential rates of protein turnover for different isozymic forms of tyrosine aminotransferase. Flumethasone, a potent difluoro synthetic glucocorticoid, was used in studies on the hormonal regulation of tyrosine aminotransferase in obese mutant mice of the C57BL/6J-ob strain. The obese mice are relatively insensitive to the action of adrenal glucocorticoids to cause liver enzyme induction.This paper was presented at a symposium entitled Genetic Control of Mammalian Metabolism held at The Jackson Laboratory, Bar Harbor, Maine, June 30–July 2, 1969. The symposium was supported in part by an allocation from NIH General Research Support Grant FR 05545 from the Division of Research Resources to The Jackson Laboratory.This investigation was supported in part by an allocation from the NIH General Research Support Grant FR 05545 from the Division of Research Resources to The Jackson Laboratory and in part by Institutional Grant IN-19 from the American Cancer Society to The Jackson Laboratory.     

Distribution of Lectin Binding Sites in Xenopus laevis Egg Jelly

Eggs from the anuran Xenopus laevis are surrounded by a thick jelly coat that is required during fertilization. The jelly coat contains three morphologically distinct layers, designated J1, J2, and J3. We examined the lectin binding properties of the individual jelly coat layers as a step in identifying jelly glycoproteins that may be essential in fertilization. The reactivity of 31 lectins with isolated jelly coat layers was examined with enzyme-linked lectin-assays (ELLAs). Using ELLA we found that most of the lectins tested showed some reactivity to all three jelly layers; however, two lectins showed jelly layer selectivity. The lectin Maackia amurensis (MAA) reacted only with J1 and J2, while the lectin Trichosanthes kirilowii (TKA) reacted only with J2 and J3. Some lectins were localized in the jelly coat using confocal microscopy, which revealed substantial heterogeneity in lectin binding site distribution among and within jelly coat layers. Wheat germ agglutinin (WGA) bound only to the outermost region of J3 and produced a thin, but very intense, band of fluorescence at the J1/J2 interface while the remainder of J2 stained lightly. The lectin MAA produced an intense fluorescence-staining pattern only at the J1/J2 interface. Several lectins were also tested for the ability to inhibit fertilization. WGA, MAA, and concanavalin A significantly inhibited fertilization and WGA was found to block fertilization by preventing sperm from penetrating the jelly. Using Western blotting, we identified high-molecular-weight components in J1 and J2 that may be important in fertilization.     

Linkage of Pgm-3 in the house mouse and homologies of three phosphoglucomutase loci in mouse and man

The discovery of a third phosphoglucomutase locus (Pgm-3) in the house mouse is reported. Three alleles are recognized on the basis of differences in electrophoretic mobility and enzymatic activity. Pgm-3 ^a (fast mobility and high activity) is present in inbred strain C57BL/10J and 24 other strains; Pgm-3 ^b (slow mobility and high activity) is present in LP/Pas and six other strains; and Pgm-3 ^c (no detectable activity in any tissue tested) is present in strain DBA/2J and 14 other strains. Seventy-four recombinant inbred strains derived from progenitors that differed at Pgm-3 were used to study genic linkage. Pgm-3 is on chromosome 9 and is linked to Sep-1, d, Mod-1, and Ltw-3. Gene order and recombination frequencies are estimated as d 3.8±1.8% Pgm-3 2.3±1.2% Mod-1. Substrate specificities and cofactor requirements show that mouse Pgm-1 is homologous with human Pgm-2, mouse Pgm-2 with human Pgm-1, and mouse Pgm-3 with human Pgm-3.This research was supported in part by NIH Research Grant GM18684 from the National Institute of General Medical Sciences to B.A.T. and by grants from NIH A105531-02 and the Volkswagon Foundation to Jan Klein. J.H.N. was a recipient of a Fellowship from the Max-Planck-Gesellschaft, Munich. G.S. and J.K. were supported by funds from the Deutsche Forschungsgemeinschaft.     

Suppressive effects of Lactobacillus casei cells,a bacterial immunostimulant,on the incidence of spontaneous thymic lymphoma in AKR mice

 The mean survival age of female AKR/J mice was significantly prolonged, the enlargement of thymus was markedly suppressed, and the proliferation of ecotropic and recombinant murine leukemia viruses (MuLV) was markedly inhibited when 8-week-old female AKR/J mice were injected intraperitoneally (i. p.) with heat-killed Lactobacillus casei cells twice weekly for 8 weeks. In contrast, such actions of heat-killed L. casei cells were not seen in 20-week-old female AKR/J mice. The leukemogenic activity of the cell-free extract of thymus from adult female AKR/J mice in newborn female AKR/J mice was drastically reduced by i. p. treatment with heat-killed L. casei cells. The difference in adjuvant effectiveness of heat-killed L. casei cells on 8- and 20-week-old animals may be dependent on the difference in the enhancing activity of the cell-mediated immune systems between the groups induced by heat-killed L. casei cells, and, as a result, on the difference in the degree of proliferation of ecotropic and recombinant MuLV in thymus, which consequently causes thymic lymphoma. Received: 13 February 1996 / Accepted: 18 April 1996     

Deciphering the ‘Elixir of Life’: Dynamic Perspectives into the Allosteric Modulation of Mitochondrial ATP Synthase by J147, a Novel Drug in the Treatment of Alzheimer's Disease

The discovery of J147 represented a significant milestone in the treatment of age‐related disorders, which was further augmented by the recent identification of mitochondrial ATP synthase as the therapeutic target. However, the underlying molecular events associated with the modulatory activity of J147 have remained unresolved till date. Herein, we present, for the first time, a dynamical approach to investigate the allosteric regulation of mATP synthase by J147, using a reliable human αγβ protein model. The highlight of our findings is the existence of the J147‐bound protein in distinct structural associations at different MD simulation periods coupled with concurrent open?close transitions of the β catalytic and α allosteric (ATP5A) sites as defined by Cα distances (d), TriCα (Θ) and dihedral (φ) angular parameters. Firstly, there was an initial pairing of the αγ subunits away from the β subunit followed by the formation of the ‘non‐catalytic’ αβ pair at a distance from the γ subunit. Interestingly, J147‐induced structural arrangements were accompanied by the systematic transition of the β catalytic site from a closed to an open state, while there was a concurrent transition of the allosteric site from an open α_E conformation to a closed state. Consequentially, J147 reduced the structural activity of the whole αγβ complex, while the unbound system exhibited high atomistic deviations and structural flexibility. Furthermore, J147 exhibited favorable binding at the allosteric site of mATP synthase with considerable electrostatic energy contributions from Gln215, Gly217, Thr219, Asp312, Asp313, Glu371 and Arg406. These findings provide details on the possible effects of J147 on mitochondrial bioenergetics, which could facilitate the structure‐based design of novel small‐molecule modulators of mATP synthase in the management of Alzheimer's disease and other neurodegenerative disorders.     

Comparative study on the gametophyte morphology and development of three paramo species of Jamesonia (Pteridaceae,Polypodiopsida)

The sexual phase of three species of Jamesonia (J. imbricata, J. rotundifolia and J. scammaniae) has been studied, from spore germination to gametangia formation, with special attention to the morphological development of prothalli. This is the first work to deal with gametophytes of species in this genus. All three species have trilete, tetrahedrical spores that germinate following the Vittaria type. The developmental pattern of J. imbricata and J. rotundifolia is intermediate between the Adiantum and Ceratopteris types, as the initial mitotic activity is assumed by an obconical apical cell, substituted later by a lateral meristem. In J. scammaniae, no apical cell or lateral meristem is formed, so the prothalli remain ameristic throughout the developmental process. Adult gametophytes are naked and variable in shape, in the same species ranging from typical cordate prothalli to irregularly lobed forms. Gametangia of normal shape and size was observed in both J. imbricata and J. rotundifolia, but not in J. scammaniae. Apogamy could be expected to occur in the genus, a phenomenon to be examined in the future. Comparisons are made with known species of related genera and results are discussed from an ecological perspective in the paramo environment.     

Screening of antagonistic bacterial strains against Meloidogyne incognita using protease activity

Twenty-six bacterial strains that had demonstrated antagonism to some fungal and bacterial pathogens were evaluated for their ability to inhibit Meloidogyne incognita Kofoid & White. The inhibition rates of egg-hatching and second-stage juveniles (J2) mortality of M. incognita by these strains ranged from ?16.5 to 87.4% and from 1.3 to 77.8%, respectively. The 12 strains causing J2 mortality over 40% were chosen for greenhouse experiments in which their biocontrol efficacy reached 33.3–65.6%. On the other hand, among the 26 strains, 20 demonstrated in vitro protease activity and 14 revealed chitinase activity. Significantly, strains Bacillus sp. AR156 and GJ24 in greenhouse tests showed the strongest protease activities. The analyses of the relationships of the efficacy of the 12 strains with their protease and chitinase activities, respectively, indicated that biocontrol efficacy was highly correlated with protease activity (r=0.92, P<0.001) but barely correlated with chitinase activity. The strong positive correlation between protease activity and efficacy suggests that in vitro protease activity could be used as a parameter for selecting biological control agents (BCAs) against root-knot nematodes. Consistently, the biocontrol efficacy of AR156, GJ24, abamectin reached 74.3, 73.4, and 40.9% in the field in Huai-an, Jiangsu; and 71, 69.9, and 37% in Zao-zhuang, Shandong, respectively. The fact that the strains with high protease activities also had significantly higher biocontrol efficacy than abamectin in the field implies that in vitro protease activity may be adopted as a reliable new parameter for speeding up the process of screening the biological control agents (BCAs).     

Tyrosinase inhibitory flavonoid from Juniperus communis fruits

The fruits of Juniperus communis have been traditionally used in the treatment of skin diseases. In our preliminary experiment, the MeOH extract of J. communis effectively suppressed mushroom tyrosinase activity. Three monoflavonoids and five biflavonoids were isolated from J. communis by bioassay-guided isolation and their inhibitory effect against tyrosinase was evaluated. According to the results of all isolates, hypolaetin 7-O-β-xylopyranoside isolated from J. communis exhibited most potent effect of decreasing mushroom tyrosinase activity with an IC₅₀ value of 45.15 μM. Further study provided direct experimental evidence for hypolaetin 7-O-β-D-xylopyranoside-attenuated tyrosinase activity in α-MSH-stimulated B16F10 murine melanoma cell. Hypolaetin 7-O-β-D-xylopyranoside from the EtOAc fraction of J. communis was also effective at suppressing α-MSH-induced melanin synthesis. This is the first report of the enzyme tyrosinase inhibition by J. communis and its constituent. Therapeutic attempts with J. communis and its active component, hypolaetin 7-O-β-D-xylopyranoside, might be useful in treating melanin pigmentary disorders.     

Extracellular complex of chitinolytic enzymes of <Emphasis Type="Italic">Clostridium paraputrificum</Emphasis> strain J4 separated by membrane ultrafiltration

Membrane diafiltration was used for separation of the extracellular complex of chitinolytic enzymes of C. paraputrificum J4 free from contaminants with molar mass higher than 100 kDa and lower than 30 kDa. The enzyme complex containing β-N-acetylglucosaminidase (NAGase) and six endochitinases was concentrated on a membrane with cut-off 30 kDa. In this retentate, the NAGase/endochitinase specific activity was 13.5/6.5-times higher than in the initial culture filtrate. The proportion (in %) of endochitinases: 23 (90 kDa), 42 (86 kDa), 8 (72 kDa), 16 (68 kDa) and 8 (60 kDa) was calculated from their peak areas (determined by densitometry) in images of zymograms. NAGase (38 kDa) was less active and stable at pH lower than 4 and higher than 8 but it was more temperature-stable than endochitinases, especially at 40–60 °C. In contrast to endochitinases, the pH optimum of NAGase activity was shifted by ca. 0.7 pH units to the alkaline region. Extracellular NAGase together with six endochitinases secreted by C. paraputrificum J4 were separated by membrane diafiltration and characterized by molar mass, stability and activity in dependence on pH and temperature. The knowledge of composition of chitinolytic enzymes, their pH and temperature stability is useful for optimization of the separation process.     

Activatory effect of regucalcin on hepatic plasma membrane (Ca2+-Mg2+)-ATPase is impaired by liver injury with carbon tetrachloride administration in rats

Human thymus poly(A) polymerase (EC 2.7.7.19) activity has been investigated using poly(A) and oligo(A) as initiators. All obtained fractions reveal more than one polypeptide as detected by immunoblotting after SDS-PAGE. In addition to the homogeneously purified (Tsiapalis et al., J Biol Chem 250: 4486–1496, 1975 and Wahle, J Biol Chem 266: 3131–3139, 1991), about 60 kDa polypeptide, a larger polypeptide, about 80 kDa, that comigrates in the region of poly(A) polymerase activity was detected, enriched and partially characterized; it appears having similar size with bovine poly(A) polymerase cloned in E. coli. Polyclonal antiserum produced against recombinant bovine poly(A) polymerase reacts more efficiently with the about 80 kDa polypeptide upon immunoblotting, and can precipitate the poly(A) polymerase activity. This enzyme form, from human tissue, is novel in terms of size and may reflect intact or physiological form of poly(A) polymerase in human thymus, and supports and substantiates recent reports on the enzyme from other sources.     

States of high conductance in a large-scale model of the visual cortex

This paper reports on the consequences of large, activity dependent, synaptic conductances for neurons in a large-scale neuronal network model of the input layer 4C of the Macaque primary visual cortex (Area V1). This high conductance state accounts for experimental observations about orientation selectivity, dynamics, and response magnitude (D. McLaughlin et al. (2000) Proc. Natl. Acad. Sci. USA 97: 8087–8092), and the linear dependence of Simple cells on visual stimuli (J. Wielaard et al. (2001) J. Neuroscience 21: 5203–5211). The source of large conductances in the model can be traced to inhibitory corticocortical synapses, and the model's predictions of large conductance changes are consistent with recent intracellular measurements (L. Borg-Graham et al. (1998) Nature 393: 369–373; J. Hirsch et al. (1998) J. Neuroscience 15: 9517–9528; J.S. Anderson et al. (2000) J. Neurophysiol. 84: 909–926). During visual stimulation, these conductances are large enough that their associated time-scales become the shortest in the model cortex, even below that of synaptic interactions. One consequence of this activity driven separation of time-scales is that a neuron responds very quickly to temporal changes in its synaptic drive, with its intracellular membrane potential tracking closely an effective reversal potential composed of the instantaneous synaptic inputs. From the effective potential and large synaptic conductance, the spiking activity of a cell can be expressed in an interesting and simplified manner, with the result suggesting how accurate and smoothly graded responses are achieved in the model network. Further, since neurons in this high-conductance state respond quickly, they are also good candidates as coincidence detectors and burst transmitters.     

α‐Glucosidase Inhibitory Xanthones from the Roots of Garcinia fusca

Two new compounds, fuscaxanthones J ( 1 ) and K ( 2 ), together with eight known xanthones ( 3 – 10 ) were isolated from an ethyl acetate extract of the roots of Garcinia fusca. Their structures were determined using spectroscopic methods, mainly 1D‐ and 2D‐NMR. α‐Glucosidase inhibitory activity of the isolated compounds was evaluated and fuscaxanthone J ( 1 ) showed the most significant effect with an IC₅₀ value of 8.3 ± 1.8 μm (compared with acarbose, IC₅₀ = 214.5 ± 2.3 μm ).     

Chemical Composition and Antioxidant Activity of Essential Oils and Methanol Extracts of Different Parts from Juniperus rigida Siebold & Zucc.

The chemical composition and antioxidant activity of essential oils and MeOH extracts of stems, needles, and berries from Juniperus rigida were studied. The results indicated that the yield of essential oil from stems (2.5%) was higher than from needles (0.8%) and berries (1.0%). The gas chromatography/mass spectrometer (GC/MS) analysis indicated that 21, 17, and 14 compounds were identified from stems, needles, and berries essential oils, respectively. Caryophyllene, α‐caryophyllene, and caryophyllene oxide were primary compounds in both stems and needles essential oils. However, α‐pinene and β‐myrcene mainly existed in berries essential oils and α‐ionone only in needles essential oils. The high‐performance liquid chromatography (HPLC) analysis indicated that the phenolic profiles of three parts exhibited significant differences. Needles extracts had the highest content of chlorogenic acid, catechin, podophyllotoxin, and amentoflavone, and for berries extracts, the content of those compounds was the lowest. Meanwhile, three in vitro methods (DPPH, ABTS, and FRAP) were used to evaluate antioxidant activity. Stems essential oil and needles extracts exhibited the powerful antioxidant activity than other parts. This is the first comprehensive study on the different parts of J. rigida. The results suggested that stems and needles of J. rigida are useful supplements for healthy products as new resources.     

土壤与大气Cu处理下迎春的耐性和富集特征研究

作为北京市常见园林灌木树种之一，迎春(Jasminum nudiflorum)因其在早春独特的观赏性而深受市民喜爱。Cu污染是北京市较为严重的重金属污染类型之一。为探讨迎春对城市Cu污染的修复作用，该文通过模拟北京市土壤和大气Cu污染条件，采用盆栽试验，设置9种不同浓度的土壤和大气Cu处理，以验证迎春Cu富集能力及生理生长特性。结果表明：(1)土壤和大气沉降处理均能显著增加迎春根、茎、叶中的Cu含量，其中土壤贡献率为63.48%～96.99%。各处理中Cu含量均表现为根>茎>叶。(2)大气处理下光化学转化效率(F_v/F_m)和相对叶绿素含量(SPAD值)提高，初始荧光(F₀)降低，光合能力增强，而土壤处理及土壤和大气双重处理则对迎春的光合作用产生抑制影响。(3)与大气处理相比，土壤处理及土壤和大气双重处理导致活性氧(ROS)积累增多，膜脂过氧化作用加剧，丙二醛(MDA)含量大幅升高，抗氧化酶活性与脯氨酸(PRO)含量逐渐下降，造成生物膜系统损伤。(4)低浓度Cu处理对迎春生长有促进作用，而高浓度Cu处理(SHA...     

Immunostimulatory effect of spinach aqueous extract on mouse macrophage-like J774.1 cells and mouse primary peritoneal macrophages

We herein report the immunostimulatory effect of spinach aqueous extract (SAE) on mouse macrophage-like J774.1 cells and mouse primary peritoneal macrophages. SAE significantly enhanced the production of interleukin (IL)-6 and tumor necrosis factor-α by both J774.1 cells and peritoneal macrophages by enhancing the expression levels of these cytokine genes. In addition, the phagocytosis activity of J774.1 cells was facilitated by SAE. Immunoblot analysis revealed that SAE activates mitogen-activated protein kinase and nuclear factor-κB cascades. It was found that SAE activates macrophages through not only TLR4, but also other receptors. The production of IL-6 was significantly enhanced by peritoneal macrophages from SAE-administered BALB/c mice, suggesting that SAE has a potential to stimulate macrophage activity in vivo. Taken together, these data indicate that SAE would be a beneficial functional food with immunostimulatory effects on macrophages.