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1.
QUAN Zijiao HAN Lingshu CAO Yue GAO Pingping LIU Xiaoyu CHANG Yaqing DING Jun 《中国海洋大学学报(英文版)》2021,20(2)
Peroxisome proliferators-activated receptor gamma(PPARγ) plays important regulatory roles in adipocyte differentiation. In this study, we cloned the full-length sequence of the PPARγ gene and analyzed its expression profile in different developmental stages and tissues of Strongylocentrotus intermedius. The full-length cDNA of PPARγ contains 2286 base pairs(bp) with a putative open reading frame of 1755 bp, and the gene encodes encoding a polypeptide of 584 amino acid residues. The predicted molecular mass of the protein is 67.27 kDa, and its theoretical isoelectric point(pI) is 10.07. The protein contains conserved motifs, including an RRM(RNA recognition motif) domain. PPARγ expression with the highest level was observed in the gonad, and the lowest was observed in the tube feet of S. intermedius. Time-course expression measurements at different developmental stages showed that the highest expression level of PPARγ is in the eggs and its weakest expression level is in the 32-cells stage. Knock-down of PPARγ by specific siRNA revealed that UCP2 expression is significantly decreased in the gonads and intestines 48 h post-transfection, indicating that the UCP2 is a downstream target gene of PPARγ.This finding suggests that PPARγ and UCP2 have positive regulatory effects in regulating adipocyte differentiation. Changes in fatty acid levels in the gonads before and after PPARγ interference were assessed, and decreased C18:2(trans, n-6) and C20:3(n-6) levels were observed 48 h after siRNA transfection. The results showed the function of PPARγ in fatty acid anabolism, The data are helpful to improve the current understanding of the fatty acid synthesis pathways and regulatory mechanisms in S. intermedius. They also provide an experimental basis for improving fatty acid synthesis in sea urchins, which is important for cultivating sea urchins with high nutritional value. 相似文献
2.
Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies. a-Glucosidase and a-amylase are the crucial factors in regulating starch digestion and glucose absorption, making them key targets for many studies to treat postprandial hyperglycemia. We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinal a-glucosidase and pancreatic a-amylase along with the antidiabetic effect to induce differentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining. Fucoxanthin displayed strong hindrance activities toward a-amylase in a concentration-dependent manner, with an IC_(50) value of 0.68 mmol/L, whereas weak inhibitory activity against a-glucosidase, with an IC_(50) value of 4.75 mmol/L. Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-LI cells by 31.3% at 5 μmol/L. During adipocyte differentiation, fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20 μmol/L. However, fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase. These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement. 相似文献
3.
As molecular weight controls the biological activities of polysaccharides, screening the optimal molecular weight of polysaccharides is important in drug research and application. In this study, hydrogen peroxide was employed as oxidant, and temperature, reaction time, and concentration of polysaccharides and hydrogen peroxide were examined for their effects on the preparation of polysaccharides in different molecular weights from Ulva pertusa. Our experiment suggested that the optimal degradation concentrations for polysaccharides and hydrogen peroxide were 2.5% (w/v) and 8.0% (v/v), respectively. The range of degradation measured by relative viscosity was mainly controlled by temperature and time. Results revealed that 35℃ was the optimal temperature for obtaining low-degradation samples, and 50℃ was the most favorable temperature to accelerate the reaction to yield highly-degraded samples. Four samples in different molecular weights A, B, C and D were finally prepared. The controllability was evaluated by the relative standard deviation (RSD) of relative viscosity, and the peak molecular weights and the polydispersity indexes (Mw/Mn) of molecular weights were measured by high performance gel permeation chromatography (HPGPC). 相似文献
4.
Mackerel(Pneumatophorus japonicus) proteins were hydrolyzed by five proteases:trypsin,papain,neutrase,acid protease,and flavourzyme.The hydrolysate treated by neutrase exhibited the highest antioxidant activity.Response surface methodology(RSM) was employed to optimize the hydrolysis conditions in an effort to obtain a mackerel protein hydrolysate(MPH) with the highest DPPH radical scavenging activity.The MPH was fractioned using a series of ultrafiltration membranes and five fractions,namely,MPH-Ⅰ(10kDa),MPH-Ⅱ(10-2.5 kDa),MPH-Ⅲ(1-2.5 kDa),MPH-Ⅳ(0.4-1 kDa),and MPH-V(below 0.4 kDa),were obtained.DPPH radical scavenging activity,reducing power,hydroxyl radical scavenging activity,and the lipid peroxidation inhibition capability of these fractions were evaluated.The fractions in molecular weights 2.5 kDa(MPH-Ⅲ,MPH-Ⅳ,and MPH-Ⅴ),which occupied 93.4%of the total fractions,showed the strongest antioxidant activity;and the antioxidant activities of the three fractions are similar to each other.Using SP Sephadex C-25 and Sephadex G-25 columns,eight fractions were obtained from the MPH(2.5 kDa).The isolated peptide I(1 664 kDa) displayed the highest DPPH radical scavenging activity.Therefore,MPH is a potential source of antioxidant peptides. 相似文献
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6.
In this study, the Alaska pollock protein isolate(APPI) was hydrolyzed by Neutrase for 20, 40, 80, 120, 160, 200, and 240 min. Hydrolysates with different molecular weights were produced and they were named as H1–H7. Furthermore, the effects of hydrolysis on the average molecular weights, functional properties(solubility, oil-holding capacities, foaming activities, and emulsifying properties), and antioxidant activities(1, 1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl free radical-scavenging activities) were determined. It was found that when the degree of hydrolysis(DH) increased, the average molecular weights of the hydrolysates decreased significantly. The functional properties of APPI were also significantly improved. The hydrolysates of APPI exhibited better solubility, emulsifying activities, and foaming activities. Hydrolysates with low molecular weights(1 kDa) had better solubility, oil-holding capacities, and emulsifying activities, while hydrolysates with higher molecular weights(1 kDa) had better foaming activities. In addition, the hydrolysates exhibited excellent antioxidant properties, while the inhibition values of 1, 1-diphenyl-2-picryl hydroxyl(DPPH), superoxide, and hydroxyl free radical-scavenging activities, were 85.22%, 53.56%, and 75.00% respectively, when the concentration of the hydrolysates was 5.0 mg mL~(-1). The lower the average molecular weight was, the higher was the antioxidant activity. These results indicated that hydrolysis with Neutrase is an effective method for improving the functional and antioxidant properties of APPI. The hydrolysates of APPI displayed great potentials to be used as natural antioxidants in protein-rich aqueous foods such as nutrient supplements and sports beverages. 相似文献
7.
In most bacteria,plants and algae,fatty acid biosynthesis is catalyzed by a group of freely dissociable proteins known as the type II fatty acid synthase(FAS II) system.In the FAS II system,enoylacyl carrier protein reductase(ENR) acts as a determinant for completing the cycles of fatty acid elongation.In this study,the cDNA sequence of ENR,designated as IgENR,was isolated from the microalga Isochrysis galbana CCMM5001.RACE(rapid amplification of cDNA ends) was used to isolate the full-length cDNA of IgENR(1 503 bp),which contains an open reading frame(ORF) of 1 044 bp and encodes a protein of 347 amino acids.The genomic DNA sequence of IgENR is interrupted by four introns.The putative amino acid sequence is homologous to the ENRs of seed plants and algae,and they contain common coenzymebinding sites and active site motifs.Under different stress conditions,real-time quantitative polymerase chain reaction(RT-qPCR) showed the expression of IgENR was upregulated by high temperature(35℃),and downregulated by depleted nitrogen(0 mol/L).To clarify the mechanism of lipids accumulating lipids,other genes involved in lipids accumulation should be studied. 相似文献
8.
《中国海洋大学学报(英文版)》2010,(4)
This study was conducted to compare lipid and fatty acid composition of cod, haddock and halibut.Three groups of cod (276 g±61 g), haddock (538 g±83 g) and halibut (3704 g±221 g) were maintained with commercial feeds mainly based on fish meal and marine fish oil for 12 weeks prior to sampling.The fatty acid compositions of muscle and liver were determined by GC/FID after derivatization of extracted lipids into fatty acid methyl esters (FAME).Lipids were also fractionated into neutral and polar lipids using Waters silica Sep-Pak.The phospholipid fraction was further separated by high-performance thin-layer chromatography (HPTLC) and the FAME profile was obtained.Results of the present study showed that cod and haddock were lean fish and their total muscle lipid contents were 0.8% and 0.7%, respectively, with phospholipid constituting 83.6% and 87.5% of the total muscle lipid, respectively.Halibut was a medium-fat fish and its muscle lipid content was 8%, with 84% of the total muscle lipid being neutral lipid.Total liver lipid contents of cod, haddock and halibut were 36.9%, 67.2% and 30.7%, respectively, of which the neutral lipids accounted for the major fraction (88.1%-97.1%).Polyunsaturated fatty acids were the most abundant in cod and haddock muscle neutral lipid.Monounsaturated fatty acid level was the highest in halibut muscle neutral lipid.Fatty acid compositions of phospholipid were relatively constant.In summary, the liver of cod and haddock as lean fish was the main lipid reserve organ, and structural phospholipid is the major lipid form in flesh.However, as a medium-fat fish, halibut stored lipid in both their liver and muscle. 相似文献
9.
《中国海洋湖沼学报》2016,(6)
Flavobacterium columnare causes columnaris disease in freshwater fi sh. In the present study, the antigenic regions of fi ve outer membrane proteins(OMPs), including zinc metalloprotease, prolyl oligopeptidase, thermolysin, collagenase and chondroitin AC lyase, were bioinformatically analyzed, fused together, and then expressed as a recombinant fusion protein in Escherichia coli. The expressed protein of 95.6 k Da, as estimated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was consistent with the molecular weight deduced from the amino acid sequence. The purifi ed recombinant protein was used to vaccinate the grass carp, C tenopharyngodon idella. Following vaccination of the fi sh their Ig M antibody levels were examined, as was the expression of I g M, Ig D and Ig Z immunoglobulin genes and other genes such as MHC Iα and MHC I I β, which are also involved in adaptive immunity. Interleukin genes( IL), including I L- 1β, IL- 8 and I L- 10, and type I and type II interferon(I FN) genes were also examined. At 3 and 4 weeks post-vaccination(wpv), signifi cant increases in Ig M antibody levels were observed in the fi sh vaccinated with the recombinant fusion protein, and an increase in the expression levels of I g M, Ig D and Ig Z genes was also detected following the vaccinations, thus indicating that an adaptive immune response was induced by the vaccinations. Early increases in the expression levels of IL and IFN genes were also observed in the vaccinated fi sh. At four wpv, the fi sh were challenged with F. column a re, and the vaccinated fi sh showed a good level of protection against this pathogen, with 39% relative percent survival(RPS) compared with the control group. It can be concluded, therefore, that the fi ve OMPs, in the form of a recombinant fusion protein vaccine, induced an immune response in fi sh and protection against F. columnare. 相似文献
10.
The inadequate nutrient content of pellet feeds widely used in recent years in China for grass carp forming led to lipid liver degeneration in the fish. The present studies show that the pathological features of lipid liver disease are anaemia and hepatic ceroidosis. Other clinical features are: the ratio of liver to body weight exceeds 3% and lipid content exceeds 5%. Extreme infiltration of hepaiocytes by lipid results in the following deteriorative effects: swelling of the liver cells, increase of lipid droplets in the cytoplasm and dislocation of the nucleus, loss of cytoplasm staining affinity, and increased activities of GOT and GPT in serum. Lipid liver degeneration of grass carp can be divided into three stages: 1) deposition of liver lipid; 2) lipid infiltration of hepatic parenchyma; 3) atrophy of liver nucleus. The causes of lipid liver degeneration are complicated, but the main cause is assumed to be an imbalance of nutrients in daily feed and the lack of some lipotropic substances. 相似文献
11.
Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics. 相似文献
12.
Illuminating conditions are crucial factors affecting the microalgal growth and biosynthesis.The effects of illuminating spectral quality on the growth and bio-component production of Nannochloris oculata were investigated.The results indicated that a high proportion of Red-light enhanced the pigments and carbohydrate production but reduced those of the biomass and lipid.Mono-chromatic Blue-light has advantageous effects on lipid production compared with Red-and White-light.The optimal light spectrum for the protein production was the combination of Red-and Blue-light at a ratio of 4:3 or 5:2.Among the seven fatty acids identified from N.oculata,the contents of C16:0,C18:0,and C18:3(n-3)in the lipid were inhibited by the increased proportion of Red-light while those of C18:2(n-9),C16:2(n-6),and C20:0 were inhibited by Blue-light.Monochromatic Red-and Blue-light and their com-binations were proposed as a promising illuminating strategy for the large-scale cultivation aiming for various bio-components. 相似文献
13.
《中国海洋湖沼学报》2021,(2)
Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could re spond to environmental changes with minimum energy.Therefore,slight fluctuations in water environment may have a great impact on physiological processes such as feeding and metabolism.Large-scale mortality often occurs during the intermediate rearing processes,and high temperatures in summer are considered the leading cause of mortality.To understand the physiological and molecular response patterns of A.broughtonii at high temperatures and to estimate the appropriate metabolism temperature for A.broughtonii,the effects of temperature on the respiratory metabolism and food intake at different growth stages were studied.The response patterns of heat shock protein genes to heat stress and post-stress recovery were also explored.Results show that the temperature and growth stage of A.broughtonii were two important factors affecting metabolism and feeding.The optimum temperature for feeding and physiological activities in each shelllength group was 24℃.The temperature at which the peak metabolic rate occurred in each shell-length group increased with the increase in shell length.With the increase in heat stress,the expression of three heat shock protein genes(Abhsp60,Abhsp70,and Abhsp90) in the tissues of two size groups of A.broughtonii increased significantly when temperature was above 24℃ and reached a peak at 30℃.After heat shock at30℃ for 2 h,the expression of the three heat shock protein genes rapidly increased,peaked at 2 h after the heat shock,and then gradually decreased to the level of the control group at 48 h after the heat shock.The three heat shock protein genes respond rapidly to heat stress and can be used as indicators to the cellular stre ss response in A.broughtonii under an environmental stre ss. 相似文献
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15.
Heavy metals, including cadmium(Cd), are widespread pollutants of great environmental concern because of their accumulation and toxicity. Environmental conditions can affect the accumulation and elimination of Cd in organisms. The aim of this study is to understand the respective responses of metallothioneins(MTs), P-glycoprotein(P-gp), and heat shock protein 70(hsp70) genes in the mantle and digestive gland of the oyster Crassostrea gigas exposed to 10 μg L-1 Cd for 28 days, followed by a depuration period of 35 days under different feeding strategies. The MT expression in the digestive gland was higher than in mantle, and was induced in a fluctuating pattern throughout the time of the whole experiment when the oyster was exposed to Cd. The results indicated an enhanced MT activity is required for Cd detoxification. Expression levels of P-gp in the mantle of Cd-exposed oysters fed with algae increased in the first two weeks of the accumulation phase. Then the induction weakened, but the expression still increased significantly compared with the control group fed without algae. The P-gp levels in the digestive gland were under-regulated during both the contamination and decontamination periods except in the group fed with Dicrateria inornata at day 0.083. The induction of P-gp is possibly related to the important role of pumping Cd out of the cell, while a major implication of P-gp expression inhibition would be a disruption of the protein synthesis. Hsp70 expression exhibited an overall decreasing trend. The highest relative hsp70 inhibition occurred during day 42 to day 63, with approximately 4-fold and 10-fold lower hsp70 levels as compared to the C.gigas feeding with no algae in the mantle and digestive gland, respectively. The induction of hsp70 may be explained by the refolding of protein in presence of Cd, followed by the inhibition of hsp70 when the protein synthesis was disrupted. 相似文献
16.
Antiviral active peptide from oyster 总被引：1，自引：0，他引：1
An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster （Crassostrea gigas） and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight （〉10 kDa, 10-5 kDa, 5-1 kDa and 〈1 kDa） using ultrafiltration membranes and dialysis. The fraction of 10-5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram （HPLC） by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect （CPE）. The result shows that the peptide has high inhibitory activity on herpetic virus. 相似文献
17.
The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization (SSH) to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COΙ. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and COΙ so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster. 相似文献
18.
Tissue-specific bioaccumulation and oxidative stress responses in juvenile Japanese flounder (Paralichthys olivaceus) exposed to mercury 总被引：1，自引：0，他引：1
To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 μg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder. 相似文献
19.
From March 2004 to February 2005,seasonal variations in lipid content and fatty acid composition of gonad of the cockle Fulvia mutica(Reeve) were studied on the eastern coast of China in relation to the reproductive cycle and environment conditions(e.g.,temperature and food availability).Histological analysis as well as lipid and fatty acid analyses were performed on neutral and polar lipids of the gonad.Results showed that gametogenesis occurred in winter and spring at the expense of lipids previously accumulated in summer and autumn,whereas spawning occurred in summer(20.4-24.6℃).The seasonal variation in lipid content was similar to that of the mean oocyte diameter.In both neutral and polar lipids,the 20:5n-3 and 22:6n-3 levels were relatively higher than saturated fatty acids,and polyunsaturated fatty acids were abundant,with series n-3 as the predominant component.Seasonal variations in the 20:5n-3 and 22:6n-3 levels and the principal n-3 fatty acids were clearly related to the reproductive cycle.The ∑(n-3) and ∑(n-6) values were relatively high during January-May,and the associated unsaturation index was significantly higher than that in other months.The results suggest that fatty acids play an important role in the gametogenesis of F.mutica. 相似文献
20.
《中国海洋湖沼学报》2017,(4)
Calanus sinicus,the dominant copepod in the Yellow Sea,develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass(YSCWM).The lipid accumulation mechanism for the initiation of over-summering is unknown.Here,we cultured C3 copepodites at four constant temperatures(10,13,16,and 19℃) and at three temperature regimes that mimicked the temperature variations experienced during diurnal vertical migration(10-13℃,10-16℃,and 10-19℃) for 18 days to explore the effects of temperature differences on copepod development and lipid accumulation.C.sinicus stored more lipid at low than at high temperatures.A diurnal temperature difference(10-16℃ and 10-19℃)promoted greater lipid accumulation(1.9-2.1 times) than a constant temperature of either 16℃ or 19℃,by reducing the energy cost at colder temperatures and lengthening copepodite development.Thereafter,the lipid reserve supported gonad development after final molting.Only one male developed in these experiments.This highly female-skewed sex ratio may have been the result of the monotonous microalgae diet fed to the copepodites.This study provides the first evidence that diurnal temperature differences may promote lipid accumulation in C.sinicus,and provides a foundation for future investigations into the mechanisms involved in over-summering in the YSCWM. 相似文献