17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body wei...17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.展开更多
To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificia...To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificial fertilization to the end of yolk absorption including 2 h, 12 h and 30 h after fertilization and newly hatched larvae including 1 and 3 days after hatching. The composition of lipid, fatty acids, protein and amino acids were analyzed. The content of total protein exhibited a decreasing trend during embryogenesis and larval development, and a significant reduction was detected after hatching(P < 0.05). The total lipid content remained relative stable. A significant reduction was detected in almost all amino acids after hatching except for glycine(P <0.05), while a significant decrease was found in the content of cysteine, proline, tyrosine, valine, isoleucine, leucine and phenylalanine during the yolk-sac phase(P < 0.05). On the other hand, all the groups of fatty acids remained stable during the period of embryogenesis. But after hatching, a significant decrease was found in the content of C18:2n-6, C18:3n-6, SFA and ratio of EPA/ARA(P < 0.05), while a significant increase was found in the content of C18:3n-3, C20:4n-6, C22:6n-3 and ratio of n-3/n-6(P < 0.05). In conclusion, the combined data suggested that American shad utilizes the protein content as preferential energy substrates during embryonic and early larval developments with some specificity in the consumption of different amino acids.展开更多
An 8-week feeding trial was conducted to determine the optimal dietary protein-to-lipid ratio for juvenile Nibea albiflora with an initial weight of(11.76 ± 0.20) g.Nine experimental diets containing different co...An 8-week feeding trial was conducted to determine the optimal dietary protein-to-lipid ratio for juvenile Nibea albiflora with an initial weight of(11.76 ± 0.20) g.Nine experimental diets containing different concentrations of protein(40%,47%,or 54%) and lipids(5%,9%,or 13%) in a 3 × 3 factorial experimental design were tested in triplicate groups of fish,while the protein-to-energy(P/E) ratios of the diets varied in the range of 19.74–28.32 mg k J^(-1).Results showed that fish fed diets containing 9% or 13% lipids with 54% protein exhibited significantly higher weight gains and specific growth rates than those fed other diets.The feed conversion rate of fish fed the diet with 40% protein and 5% lipids was significantly poorer than that of fish fed other diets.The protein efficiency rate of fish fed diets with 5% lipids was significantly lower than that of fish fed 9% or 13% lipid diets.Carcass lipid and energy contents were positively correlated with dietary lipid level regardless of protein level.Fish fed a 54% protein diet showed the highest trypsin activity.The intestinal lipase activity of fish fed the diet containing 13% lipids was significantly higher than that of fish fed 5% or 9% lipid diets.These results demonstrate the high protein dietary requirements of N.albiflora.A diet containing 54% protein and 9%–13% lipids with a P/E ratio of 26.2–27.81 mg protein k J^(-1) can be considered optimal for juvenile N.albiflora.展开更多
The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal...The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.展开更多
Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and...Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and biotic or abiotic stress response. With the completion of the barley genome sequence, a genome-wide analysis of nsLTPs in barley(Hordeum vulgare L.)(HvLTPs) will be helpful for understanding the function of nsLTPs in plants. We performed a genome-wide analysis of the nsLTP gene family in barley and identified 70 nsLTP genes,which can be divided into five types(1, 2, C, D, and G). Each type of nsLTPs shares similar exon and intron gene structures. Expression analysis showed that barley nsLTPs have diverse expression patterns, revealing their various roles. Our results shed light on the phylogenetic relationships and potential functions of barley nsLTPs and will be useful for future studies of barley development and molecular breeding.展开更多
Abnormal intracellular accumulation or transport of lipids contributes greatly to the pathogenesis of human diseases. In the liver, excess accumulation of triacylglycerol （TG） leads to fatty liver disease encompassi...Abnormal intracellular accumulation or transport of lipids contributes greatly to the pathogenesis of human diseases. In the liver, excess accumulation of triacylglycerol （TG） leads to fatty liver disease encompassing steatosis, steatohepatitis and fibrosis. This places individuals at risk of developing cirrhosis, hepatocellular carcinoma or hepatic decompensation and also contributes to the emergence of insulin resistance and dyslipidemias affecting many other organs. Excessive accumulation of TG in adipose tissue contributes to insulin resistance as well as to the release of cytokines attracting leucocytes leading to a pro-inflammatory state. Pathological accumulation of cholesteryl ester （CE） in macrophages in the arterial wall is the progenitor of atherosclerotic plaques and heart disease. Overconsumption of dietary fat, cholesterol and carbohydrates explains why these diseases are on the increase yet offers few clues for how to prevent or treat individuals. Dietary regimes have proven futile and barfing surgery, no realistic alternatives are at hand as effective drugs are few and not without side effects. Overweight and obesity-related diseases are no longer restricted to the developed world and as such, constitute a global problem. Development of new drugs and treatment strategies are a priority yet requires as a first step, elucidation of the molecular pathophysiology underlying each associated disease state. The lipid droplet （LD）, an up to now over- looked intracellular organelle, appears at the heart of each pathophysiology linking key regulatory and metabolic processes as well as constituting the site of storage of both TGs and CEs. As the molecular machinery and mechanisms of LDs of each cell type are being elucidated, regulatory proteins used to control various cellular processes are emerging. Of these and the subject of this review, small GTPases belonging to the Rab protein family appear as important molecular switches used in the regulation of the intracellular trafficking and storage of lipids.展开更多
This study was to investigate the regulation of monoclonal antibodies against adipocyte membrane proteins （McAb） on lipid metabolism in pigs. Forty Landrace x Saba pigs were randomly divided into eight groups; the c...This study was to investigate the regulation of monoclonal antibodies against adipocyte membrane proteins （McAb） on lipid metabolism in pigs. Forty Landrace x Saba pigs were randomly divided into eight groups; the control group was given 10 mL saline and the treat groups were given monoclonal antibody against adipocyte-specific membrane protein with 0.1, 0.5, and 1.0 mg kg-I body weight at 15 and 60 kg body weight, respectively, by intraperitoneal injection. The results showed that McAb could increase, significantly, serum lipoprotein lipase activity and reduce serum nonesterified fatty acid （NEFA） content. Meanwhile, McAb increased content of serum lipid, triglyceride （TG）, cholesterol （CHO）, high density lipoprotein （HDL）, and low density lipoprotein （LDL） both at 15 and 60 kg body weight. However, McAb affected more significantly the lipid metabolism at 15 kg body weight than at 60 kg body weight. Moreover, this effect of McAb on lipid metabolism exhibited dose-dependent effect. These results suggested that this monoclonal antibody increased lipase activity, promoted lipolysis, and utilization of lipid so that McAb could be applied to restrain excessive fat deposition in porcine production through the regulation of fat metabolism.展开更多
Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles...Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles. During this study, identification of lipid microinclusions having the form of such lipid-protein structural microformations as lipid-protein microdomains, vesicles and membrane tubular structures (cytoplasmic transvacuolar strands and nanotubes) located in organelle membranes or bound up with them was conducted. Such membrane probes as laurdan, DPH, ANS and bis-ANS were used. Comparison of fluorescence intensity of these membrane probes was conducted. This investigation of the morphological properties of lipid-protein structural microformations was accompanied with analysis of 1) the phase state and 2) dynamics of microviscosity variations in the membrane elements of isolated plant cell organelles. Distributions of laurdan fluorescence generalized polarization (GP) values for the membrane on the whole and for the intensively fluorescing membrane segments were obtained. It was discovered that the microviscosity of intensively fluorescing membrane segments essentially differed from the microviscosity of the rest part of the membrane. In conclusion, some results of the study of peculiar properties of lipid-protein structural microformations related to the structure of organelle membranes and the discoveries made in this investigation are discussed.展开更多
Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules...Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules. Despite extensive research on nsLTP in different plant species, mostly angiosperm, and the great diversity of physiological processes in which they seem to be involved, their exact functions still remain unclear. Also, very limited experimental data are available on nsLTP in gymnosperm. In this study, we report for the first time on the molecular cloning of nsLTP, from Pinus sylvestris L.(PsLTP1, GenBank accession JN980402.1) and the expression pattern of PsLTP1 during ontogenesis and in response to environmental stress conditions. Total RNA from roots of 7-day old pine seedlings was used to isolate the cDNA clone, corresponding to Scots pine lipid transfer protein. The open reading frame of PsLTP1 consists of 372 bp encoding a protein of 123 amino acids. Amino acid sequence alignment revealed that mature PsLTP1 shares high level of similarity with nsLTP from other conifers and with well-studied nsLTPs from angiosperms. The PsLTP1 contains a 27-amino-acid N-terminal signal sequence and presents all the features of a plant nsLTP. Amino acid comparison analysis and 3D structure prediction showed that PsLTP1 is a type 1 nsLTP. The results of the expression analysis of Scots pine PsLTP1 gene revealed that its transcripts accumulate in actively growing tissues. Furthermore, transcription of PsLTP1 was upregulated in response to cold and salt treatments, and downregulated during acidic, osmotic and water stresses.展开更多
During the past 20 years there has been a remarkable growth in the use of fluorescence in the biological sciences. Fluorescence is now a dominant methodology used extensively in biochemistry, biophysics, biotechnology...During the past 20 years there has been a remarkable growth in the use of fluorescence in the biological sciences. Fluorescence is now a dominant methodology used extensively in biochemistry, biophysics, biotechnology, medical diagnostics, flow cytometry, DNA sequencing and genetic analysis to name a few. It is one of the most powerful methods to study protein folding, dynamics, assembly and interactions as well as membrane structure. α-Synuclein belongs to the class of intrinsically disordered proteins lacking of a well-folded structure under physiological conditions. The conversion of α-synuclein from a soluble monomer to an insoluble fibril may underlie the neurodegeneration associated with Parkinson’s disease (PD). Although the exact mechanism of α-synuclein toxicity is still unknown, it has been proposed that disturbs membrane structure, leading to increased membrane permeability and eventual cell death. This review highlights the significant role played by fluorescence techniques in unraveling the nature of interactions between α-synuclein and membranes and its implications in PD.展开更多
Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing conditio...Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing condition and about 180 × 103u under non-reducing condition. The protein molecules were reconstituted into artificial membranes composed of different ratios of phospholipids (PL)/cholesterol (Ch). Circular dichroism analysis demonstrated that there was a decrease of the beta-laminar structure and an increase of alpha-helica and random coils when the Ch content of the artificial membranes DMPC/Ch or DOPC/Ch was increased. Tryptophan fluorescence spectrum also demonstrated that along with the changes of the lipid constituents of the artificial membrane,the spatial conformation of CD71 protein underwent corresponding changes.展开更多
Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanis...Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanisole） was used as a positive control. Lipid oxidation in patties during storage was analyzed by measuring the TBARS and protein carbonyl content. The results showed that bone protein hydrolysates possessed significant antioxidant activity, and antioxidant activity increased with the increasing hydrolysates concentration. Sensory evaluation indicated that bone protein hydrolysates improved the color and decreased lipid oxidation flavor of pork patties. The 2% bone hydrolysates possessed the highest antioxidant activity and better sensory quality, and its effect was closed to 0.02% BHA.展开更多
Background: The effects of whey protein intake on the transcriptional expression of genes related to lipid metabolism in mice were investigated herein. Methods: For 4 weeks, mice were fed AIN-93G composed of either ca...Background: The effects of whey protein intake on the transcriptional expression of genes related to lipid metabolism in mice were investigated herein. Methods: For 4 weeks, mice were fed AIN-93G composed of either casein or whey protein as the protein source. Then the gastrocnemius muscle, liver, and epididymal adipose tissue were excised. Expression levels of the transcription factors, PPARα, PPARγ, and SREBP1c, and those of the enzymes modulated by these factors, HSL, LPL, ACCα, and FAS, were measured by real-time PCR. The effects of whey protein were compared to those of the case in control. Results: The mRNA expression of PPARα was enhanced in the gastrocnemius muscle, while that of PPARγ was increased in the liver and epididymal adipose tissue. The expression of HSL and LPL was increased in the epididymal adipose tissue and gastrocnemius muscle, respectively. The mRNA expression of SREBP1c was suppressed in all of the three tissues. The expression of ACCα was suppressed in the gastrocnemius muscle and liver, while that of FAS was suppressed in all of the three tissues. Conclusions: These results indicate that whey protein intakes transcriptionally modulate PPARs and SREBP1c directing lipid metabolism toward the enhancement of triglyceride breakdown and suppression of fatty acid synthesis.展开更多
Objectives In addition to its lipid-lowering properties, statin decreases the level of C-reactive protein （CRP） resulting in reduction of cardiovascular events. However, information about discontinuation of statin t...Objectives In addition to its lipid-lowering properties, statin decreases the level of C-reactive protein （CRP） resulting in reduction of cardiovascular events. However, information about discontinuation of statin therapy in stable cardiac patients is limited. This was a prospective cohort study to explore whether withdrawal of statin treatment could result in rebound of inflammation in patients with stable angina pectofis in a short-term course. Methods and Results 75 patients with stable angina pectoris were randomly divided into three groups： ① Pretreatment with Xuezhikang （XZK, an extract of cholestin） for 6 weeks and then replaced by placebo; ②Treatment with XZK throughout the study; ③ Placebo. Lipid levels, highly sensitive CRP （hs-CRP） and serum cardiac troponin T （cTnT） were assessed before receiving the XZK therapy, 1 day before discontinuation of XZK, and on day 1, 2, 3, 7 and 14 after discontinuation of XZK, respectively. At day 14 after discontinuation of XZK therapy, total cholesterol, LDL-C and triglyceride significantly increased, whereas HDL-C level significantly decreased. The median level of hs-CRP increased significantly from the second day after withdrawal of XZK therapy. There was a prominent rebound of hs-CRP concentration 3 days after discontinuation of XZK therapy. 7 to 14 days after discontinuation of XZK therapy, the hs-CRP concentration declined to a similar level as in the placebo group. Elevated eTnT level did not occur throughout the study course in either guroup Conclusios Short-term discontinuation of statin therapy could induce a rapid rebound phenomenon of inflammatory response independently of changes of lipid parameters. However, it was not enough to induce myocardial injury in this cohort of patients with stable angina peetoris.展开更多
文摘17β-estradiol modulates the activity of D2 receptors in the regulation of food intake and body weight. The functional lack of 17β-estradiol in postmenopausal women could create a dietary imbalance and cause body weight gain. This study aimed to better understand the interferences that could exist between 17β-estradiol, D2 receptors and the selection of carbohydrate, fat and protein consumption, as well as their consequences on body weight gain by using an animal model of the menopause. Ovariectomy exacerbates the consumption of foods rich in lipids. Thus confirming an inhibitory action of 17β-estradiol (E2) on the consumption of these types of foods. This consumption stimulates body weight gain, which is promoted by the high caloric content of these foods and not by the amount consumed. Our results showed a direct involvement of D2 receptors in food choice. This choice would be made according to the two (2) isoforms of the D2 receptors. The D2/BR isoform directs towards a high carbohydrate consumption, without causing a gain in body weight. While D2/SUL, promotes high fat food consumption, causing an increase in body weight. In women, 17β-estradiol modulates the activity ratio between these two D2 receptor isoforms to ensure energy and homeostatic balance, stabilizing food intake and body weight.
基金supported by the Jiangsu Province Technology Infrastructure Construction Project(No.BM201312)the Qingdao postdoctoral application research project(No.Q51201611)the State Level Commonweal Project of Research Institutes(No.20603022015005)
文摘To investigate the changes of the biochemical composition of American shad(Alosa sapidissima) eggs and larvae at embryonic and early larval stages, samples were collected at different development stages from artificial fertilization to the end of yolk absorption including 2 h, 12 h and 30 h after fertilization and newly hatched larvae including 1 and 3 days after hatching. The composition of lipid, fatty acids, protein and amino acids were analyzed. The content of total protein exhibited a decreasing trend during embryogenesis and larval development, and a significant reduction was detected after hatching(P < 0.05). The total lipid content remained relative stable. A significant reduction was detected in almost all amino acids after hatching except for glycine(P <0.05), while a significant decrease was found in the content of cysteine, proline, tyrosine, valine, isoleucine, leucine and phenylalanine during the yolk-sac phase(P < 0.05). On the other hand, all the groups of fatty acids remained stable during the period of embryogenesis. But after hatching, a significant decrease was found in the content of C18:2n-6, C18:3n-6, SFA and ratio of EPA/ARA(P < 0.05), while a significant increase was found in the content of C18:3n-3, C20:4n-6, C22:6n-3 and ratio of n-3/n-6(P < 0.05). In conclusion, the combined data suggested that American shad utilizes the protein content as preferential energy substrates during embryonic and early larval developments with some specificity in the consumption of different amino acids.
基金supported by grants from the Na-tional Natural Science Foundation of China(No.41476127)the Science and Technology Planning Project of Zhejiang Province(No.2016F50038)+1 种基金the Science and Technology Planning Project of ZhouShan City(No.2015C31010)the Scientific Research Foundation of Zhejiang Ocean Universtiy(No.2014Q1434)
文摘An 8-week feeding trial was conducted to determine the optimal dietary protein-to-lipid ratio for juvenile Nibea albiflora with an initial weight of(11.76 ± 0.20) g.Nine experimental diets containing different concentrations of protein(40%,47%,or 54%) and lipids(5%,9%,or 13%) in a 3 × 3 factorial experimental design were tested in triplicate groups of fish,while the protein-to-energy(P/E) ratios of the diets varied in the range of 19.74–28.32 mg k J^(-1).Results showed that fish fed diets containing 9% or 13% lipids with 54% protein exhibited significantly higher weight gains and specific growth rates than those fed other diets.The feed conversion rate of fish fed the diet with 40% protein and 5% lipids was significantly poorer than that of fish fed other diets.The protein efficiency rate of fish fed diets with 5% lipids was significantly lower than that of fish fed 9% or 13% lipid diets.Carcass lipid and energy contents were positively correlated with dietary lipid level regardless of protein level.Fish fed a 54% protein diet showed the highest trypsin activity.The intestinal lipase activity of fish fed the diet containing 13% lipids was significantly higher than that of fish fed 5% or 9% lipid diets.These results demonstrate the high protein dietary requirements of N.albiflora.A diet containing 54% protein and 9%–13% lipids with a P/E ratio of 26.2–27.81 mg protein k J^(-1) can be considered optimal for juvenile N.albiflora.
文摘The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.
基金supported by funds from the National Key Research and Development Program of China (2016YFD0100903)
文摘Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and biotic or abiotic stress response. With the completion of the barley genome sequence, a genome-wide analysis of nsLTPs in barley(Hordeum vulgare L.)(HvLTPs) will be helpful for understanding the function of nsLTPs in plants. We performed a genome-wide analysis of the nsLTP gene family in barley and identified 70 nsLTP genes,which can be divided into five types(1, 2, C, D, and G). Each type of nsLTPs shares similar exon and intron gene structures. Expression analysis showed that barley nsLTPs have diverse expression patterns, revealing their various roles. Our results shed light on the phylogenetic relationships and potential functions of barley nsLTPs and will be useful for future studies of barley development and molecular breeding.
文摘Abnormal intracellular accumulation or transport of lipids contributes greatly to the pathogenesis of human diseases. In the liver, excess accumulation of triacylglycerol （TG） leads to fatty liver disease encompassing steatosis, steatohepatitis and fibrosis. This places individuals at risk of developing cirrhosis, hepatocellular carcinoma or hepatic decompensation and also contributes to the emergence of insulin resistance and dyslipidemias affecting many other organs. Excessive accumulation of TG in adipose tissue contributes to insulin resistance as well as to the release of cytokines attracting leucocytes leading to a pro-inflammatory state. Pathological accumulation of cholesteryl ester （CE） in macrophages in the arterial wall is the progenitor of atherosclerotic plaques and heart disease. Overconsumption of dietary fat, cholesterol and carbohydrates explains why these diseases are on the increase yet offers few clues for how to prevent or treat individuals. Dietary regimes have proven futile and barfing surgery, no realistic alternatives are at hand as effective drugs are few and not without side effects. Overweight and obesity-related diseases are no longer restricted to the developed world and as such, constitute a global problem. Development of new drugs and treatment strategies are a priority yet requires as a first step, elucidation of the molecular pathophysiology underlying each associated disease state. The lipid droplet （LD）, an up to now over- looked intracellular organelle, appears at the heart of each pathophysiology linking key regulatory and metabolic processes as well as constituting the site of storage of both TGs and CEs. As the molecular machinery and mechanisms of LDs of each cell type are being elucidated, regulatory proteins used to control various cellular processes are emerging. Of these and the subject of this review, small GTPases belonging to the Rab protein family appear as important molecular switches used in the regulation of the intracellular trafficking and storage of lipids.
基金This work is supported by the grants from the Natural Science Foundation Key Project of Yunnan Province,China(2000C005Z)the National Natural Science Foundation of China(30260079).
文摘This study was to investigate the regulation of monoclonal antibodies against adipocyte membrane proteins （McAb） on lipid metabolism in pigs. Forty Landrace x Saba pigs were randomly divided into eight groups; the control group was given 10 mL saline and the treat groups were given monoclonal antibody against adipocyte-specific membrane protein with 0.1, 0.5, and 1.0 mg kg-I body weight at 15 and 60 kg body weight, respectively, by intraperitoneal injection. The results showed that McAb could increase, significantly, serum lipoprotein lipase activity and reduce serum nonesterified fatty acid （NEFA） content. Meanwhile, McAb increased content of serum lipid, triglyceride （TG）, cholesterol （CHO）, high density lipoprotein （HDL）, and low density lipoprotein （LDL） both at 15 and 60 kg body weight. However, McAb affected more significantly the lipid metabolism at 15 kg body weight than at 60 kg body weight. Moreover, this effect of McAb on lipid metabolism exhibited dose-dependent effect. These results suggested that this monoclonal antibody increased lipase activity, promoted lipolysis, and utilization of lipid so that McAb could be applied to restrain excessive fat deposition in porcine production through the regulation of fat metabolism.
文摘Peculiar properties of morphological structures of organelle membranes were studied by fluorescent confocal microscopy. The list of objects in our experiments was represented by mitochondria, chloroplasts and vacuoles. During this study, identification of lipid microinclusions having the form of such lipid-protein structural microformations as lipid-protein microdomains, vesicles and membrane tubular structures (cytoplasmic transvacuolar strands and nanotubes) located in organelle membranes or bound up with them was conducted. Such membrane probes as laurdan, DPH, ANS and bis-ANS were used. Comparison of fluorescence intensity of these membrane probes was conducted. This investigation of the morphological properties of lipid-protein structural microformations was accompanied with analysis of 1) the phase state and 2) dynamics of microviscosity variations in the membrane elements of isolated plant cell organelles. Distributions of laurdan fluorescence generalized polarization (GP) values for the membrane on the whole and for the intensively fluorescing membrane segments were obtained. It was discovered that the microviscosity of intensively fluorescing membrane segments essentially differed from the microviscosity of the rest part of the membrane. In conclusion, some results of the study of peculiar properties of lipid-protein structural microformations related to the structure of organelle membranes and the discoveries made in this investigation are discussed.
基金supported by grants from the Ministry of Education and Science of Ukraine(0116U003593)grant from cieA3(Campus de Excelencia Internacional Agroalimentario)-UCO,Spain
文摘Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules. Despite extensive research on nsLTP in different plant species, mostly angiosperm, and the great diversity of physiological processes in which they seem to be involved, their exact functions still remain unclear. Also, very limited experimental data are available on nsLTP in gymnosperm. In this study, we report for the first time on the molecular cloning of nsLTP, from Pinus sylvestris L.(PsLTP1, GenBank accession JN980402.1) and the expression pattern of PsLTP1 during ontogenesis and in response to environmental stress conditions. Total RNA from roots of 7-day old pine seedlings was used to isolate the cDNA clone, corresponding to Scots pine lipid transfer protein. The open reading frame of PsLTP1 consists of 372 bp encoding a protein of 123 amino acids. Amino acid sequence alignment revealed that mature PsLTP1 shares high level of similarity with nsLTP from other conifers and with well-studied nsLTPs from angiosperms. The PsLTP1 contains a 27-amino-acid N-terminal signal sequence and presents all the features of a plant nsLTP. Amino acid comparison analysis and 3D structure prediction showed that PsLTP1 is a type 1 nsLTP. The results of the expression analysis of Scots pine PsLTP1 gene revealed that its transcripts accumulate in actively growing tissues. Furthermore, transcription of PsLTP1 was upregulated in response to cold and salt treatments, and downregulated during acidic, osmotic and water stresses.
文摘During the past 20 years there has been a remarkable growth in the use of fluorescence in the biological sciences. Fluorescence is now a dominant methodology used extensively in biochemistry, biophysics, biotechnology, medical diagnostics, flow cytometry, DNA sequencing and genetic analysis to name a few. It is one of the most powerful methods to study protein folding, dynamics, assembly and interactions as well as membrane structure. α-Synuclein belongs to the class of intrinsically disordered proteins lacking of a well-folded structure under physiological conditions. The conversion of α-synuclein from a soluble monomer to an insoluble fibril may underlie the neurodegeneration associated with Parkinson’s disease (PD). Although the exact mechanism of α-synuclein toxicity is still unknown, it has been proposed that disturbs membrane structure, leading to increased membrane permeability and eventual cell death. This review highlights the significant role played by fluorescence techniques in unraveling the nature of interactions between α-synuclein and membranes and its implications in PD.
文摘Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing condition and about 180 × 103u under non-reducing condition. The protein molecules were reconstituted into artificial membranes composed of different ratios of phospholipids (PL)/cholesterol (Ch). Circular dichroism analysis demonstrated that there was a decrease of the beta-laminar structure and an increase of alpha-helica and random coils when the Ch content of the artificial membranes DMPC/Ch or DOPC/Ch was increased. Tryptophan fluorescence spectrum also demonstrated that along with the changes of the lipid constituents of the artificial membrane,the spatial conformation of CD71 protein underwent corresponding changes.
基金Supported by Foundation of Science and Technology of 11th Five-Year Plan of Heilongjiang (GB06B403)
文摘Bone protein hydrolysates were prepared by limited alcalase hydrolysis （5 h）. The hydrolysates were formulated （0-3%, w/w） into pork patties to determine the antioxidant efficacy. 0.02% BHA （butylated hydroxyanisole） was used as a positive control. Lipid oxidation in patties during storage was analyzed by measuring the TBARS and protein carbonyl content. The results showed that bone protein hydrolysates possessed significant antioxidant activity, and antioxidant activity increased with the increasing hydrolysates concentration. Sensory evaluation indicated that bone protein hydrolysates improved the color and decreased lipid oxidation flavor of pork patties. The 2% bone hydrolysates possessed the highest antioxidant activity and better sensory quality, and its effect was closed to 0.02% BHA.
文摘Background: The effects of whey protein intake on the transcriptional expression of genes related to lipid metabolism in mice were investigated herein. Methods: For 4 weeks, mice were fed AIN-93G composed of either casein or whey protein as the protein source. Then the gastrocnemius muscle, liver, and epididymal adipose tissue were excised. Expression levels of the transcription factors, PPARα, PPARγ, and SREBP1c, and those of the enzymes modulated by these factors, HSL, LPL, ACCα, and FAS, were measured by real-time PCR. The effects of whey protein were compared to those of the case in control. Results: The mRNA expression of PPARα was enhanced in the gastrocnemius muscle, while that of PPARγ was increased in the liver and epididymal adipose tissue. The expression of HSL and LPL was increased in the epididymal adipose tissue and gastrocnemius muscle, respectively. The mRNA expression of SREBP1c was suppressed in all of the three tissues. The expression of ACCα was suppressed in the gastrocnemius muscle and liver, while that of FAS was suppressed in all of the three tissues. Conclusions: These results indicate that whey protein intakes transcriptionally modulate PPARs and SREBP1c directing lipid metabolism toward the enhancement of triglyceride breakdown and suppression of fatty acid synthesis.
文摘Objectives In addition to its lipid-lowering properties, statin decreases the level of C-reactive protein （CRP） resulting in reduction of cardiovascular events. However, information about discontinuation of statin therapy in stable cardiac patients is limited. This was a prospective cohort study to explore whether withdrawal of statin treatment could result in rebound of inflammation in patients with stable angina pectofis in a short-term course. Methods and Results 75 patients with stable angina pectoris were randomly divided into three groups： ① Pretreatment with Xuezhikang （XZK, an extract of cholestin） for 6 weeks and then replaced by placebo; ②Treatment with XZK throughout the study; ③ Placebo. Lipid levels, highly sensitive CRP （hs-CRP） and serum cardiac troponin T （cTnT） were assessed before receiving the XZK therapy, 1 day before discontinuation of XZK, and on day 1, 2, 3, 7 and 14 after discontinuation of XZK, respectively. At day 14 after discontinuation of XZK therapy, total cholesterol, LDL-C and triglyceride significantly increased, whereas HDL-C level significantly decreased. The median level of hs-CRP increased significantly from the second day after withdrawal of XZK therapy. There was a prominent rebound of hs-CRP concentration 3 days after discontinuation of XZK therapy. 7 to 14 days after discontinuation of XZK therapy, the hs-CRP concentration declined to a similar level as in the placebo group. Elevated eTnT level did not occur throughout the study course in either guroup Conclusios Short-term discontinuation of statin therapy could induce a rapid rebound phenomenon of inflammatory response independently of changes of lipid parameters. However, it was not enough to induce myocardial injury in this cohort of patients with stable angina peetoris.
