Vaccarin,a flavonoid glycoside isolated from Vaccaria segetalis,is non-toxic to 3T3-L1 cells up to concentrations of 200μM.Accordingly,we investigated the effects of this natural product on adipogenesis and lipolysis...Vaccarin,a flavonoid glycoside isolated from Vaccaria segetalis,is non-toxic to 3T3-L1 cells up to concentrations of 200μM.Accordingly,we investigated the effects of this natural product on adipogenesis and lipolysis in 3T3-L1 adipocytes.Our results revealed that vaccarin significantly inhibited lipid accumulation by suppressing the adipogenesis-related transcription factors peroxisome proliferator-activated receptorγ(PPARγ)and the CCAAT/enhancer-binding proteinα(C/EBPα).Specifically,lipid accumulation decreased by up to 27.7±2.7%when 3T3-L1 adipocytes were treated with a 10μM concentration of vaccarin.Mechanistic studies showed that the compound inhibited adipogenesis through activation of the Hedgehog(Hh)signaling pathway and so restoring Smo and Gli1 expression at an early stage of differentiation.In mature 3T3-L1 cells,vaccarin significantly increased the secretion of glycerol into the surrounding medium and thus indicating that it accelerated the degradation of triglycerides.In addition,vaccarin,was shown to enhance lipolysis through stimulation of the transcription levels of lipoprotein lipase,monoglycerides lipase,adipose triacylglyceride lipase,hormone-sensitive lipase and adipose differentiated-related protein.All told,vaccarin suppressed lipid accumulation and enhanced lipolysis during adipocyte differentiation by restoring Hh signaling.As such,it is a phytochemical capable of halting adipocyte hyperplasia and,thereby,ameliorating the effects of obesity.展开更多
Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegen...Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet ( 1.5% DHA ethyl ester/kg diet) for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.展开更多
Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughou...Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughout the transition period is lipolysis from adipose tissue depots. During this time, plasma fatty acids serve as a source of calories mitigating the negative energy balance prompted by copious milk synthesis and limited dry matter intake.Past research has demonstrated that lipolysis in the adipose organ is a complex process that includes not only the activation of lipolytic pathways in response to neural, hormonal, or paracrine stimuli, but also important changes in the structure and cellular distribution of the tissue in a process known as adipose tissue remodeling. This process involves an inflammatory response with immune cell migration, proliferation of the cellular components of the stromal vascular fraction, and changes in the extracellular matrix. This review summarizes current knowledge on lipolysis in dairy cattle, expands on the new field of adipose tissue remodeling, and discusses how these biological processes affect transition cow health and productivity.展开更多
The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were stu...The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were studied.The degree of protein oxidation increased during the processes in two groups sausages,while the content of phospholipids decreased,neutral lipids and free fatty acids increased.The degree of protein oxidation,lipid oxidation and lipolysis in 4%NaCl content group was higher than those in 2%NaCl content group,while 4%NaCl content group has higher lipase activity.In conclusion,4%NaCl may facilitate the protein oxidation,lipid hydrolysis and oxidation in Chinese dry sausage,and the protein oxidation had strong correlation with lipid oxidation and lipolysis.The results could provide a basis for improving the technology of industrial production.展开更多
Lipid-based nanocarriers have staged a remarkable comeback in the oral delivery of proteins and peptides, but delivery efficiency is compromised by lipolysis. β-Lactoglobulin(β-lg) stabilized lipid nanoparticles, in...Lipid-based nanocarriers have staged a remarkable comeback in the oral delivery of proteins and peptides, but delivery efficiency is compromised by lipolysis. β-Lactoglobulin(β-lg) stabilized lipid nanoparticles, including nanoemulsions(NE@β-lg) and nanocapsules(NC@β-lg), were developed to enhance the oral absorption of insulin by slowing down lipolysis due to the protection from β-lg. Cremophor EL stabilized nanoemulsions(NE@Cre-EL) were prepared and set as a control. The lipid nanoparticles produced mild and sustained hypoglycemic effects, amounting to oral bioavailability of 3.0% ± 0.3%, 7.0% ± 1.1%, and7.7% ± 0.8% for NE@Cre-EL, NE@β-lg, and NC@β-lg, respectively. Aggregation-caused quenching(ACQ)probes enabled the identification of intact nanoparticles, which were used to investigate the in vivo and intracellular fates of the lipid nanoparticles. In vitro digestion/lipolysis and ex vivo imaging confirmed delayed lipolysis from β-lg stabilized lipid nanoparticles. NC@β-lg was more resistant to intestinal lipolysis than NE@β-lg due to the Ca^(2+)-induced crosslinking. Live imaging revealed the transepithelial transport of intact nanoparticles and their accumulation in the liver. Cellular studies confirmed the uptake of intact nanoparticles. Slowing down lipolysis via food proteins represents a good strategy to enhance the oral absorption of lipid nanoparticles and thus co-formulated biomacromolecules.展开更多
Docosahexaenoic acid(DHA)is a biologically active fatty acid that reduces the accumulation of lipids.However,the molecular mechanism underlying this process,particularly in fish,is not well understood.Recent studies s...Docosahexaenoic acid(DHA)is a biologically active fatty acid that reduces the accumulation of lipids.However,the molecular mechanism underlying this process,particularly in fish,is not well understood.Recent studies show that endoplasmic reticulum(ER)stress triggers the activation of the unfolded protein response,which has been revealed to play an essential role in lipid metabolism.In this study,we explored the effect of DHA on ER stress and investigated the potential molecular mechanisms underlying DHA-induced adipocyte lipolysis in grass carp(Ctenopharyngodon idella)both in vivo and in vitro.We found that DHA remarkably reduced the triglyceride content,increased the secretion of glycerol,pro-moted lipolysis in adipocytes and evoked ER stress,whereas inhibiting ER stress using 4-phenyl butyric acid(4-PBA)inhibited the effects of DHA(P<0.05).These results implied that ER stress potentially participates in DHA-induced adipocyte lipolysis.Additionally,STF-083010,a specific inositol-requiring enzyme 1a(IRE1a)-inhibitor,attenuated the effects of DHA on lipolysis,demonstrating that IRE1a and X-box binding protein 1 potentially participate in DHA-induced lipolysis.DHA also activated the cyclic adenosine monophosphate(cAMP)-dependent protein kinase A(PKA)pathway by increasing the level of cAMP and activating the PKA enzyme(P<0.05).Nevertheless,H89,a PKA inhibitor,weakened DHA-induced lipolysis by inhibiting the cAMP/PKA signaling pathway.Furthermore,inhibiting ER stress us-ing 4-PBA also inhibited lipolysis and alleviated DHA-induced activation of the cAMP/PKA signaling pathway,suggesting that ER stress may participate in DHA-induced lipolysis through the activation of the cAMP/PKA signaling pathway.Our data illustrate that DHA supplementation can be a promising nutritional strategy for ameliorating lipid accumulation in grass carp.The present study elucidated the molecular mechanism for DHA-induced lipolysis in grass carp adipocytes and emphasized the impor-tance of ER stress and the cAMP/PKA pathway in DHA-induced lipolysis.These results deepen our un-derstanding of ameliorating lipids deposition in freshwater fish by targeting DHA.展开更多
The in vitro digestion models mimicking the gastrointestinal(GI)tract of general population and lipid indigestion patients(with lower levels of bile salts or pancreatic lipase)were selected to investigate whether diac...The in vitro digestion models mimicking the gastrointestinal(GI)tract of general population and lipid indigestion patients(with lower levels of bile salts or pancreatic lipase)were selected to investigate whether diacylglycerols(DAGs)are potential good lipid sources for these patients.Linseed oil-based DAG(LD)and linseed oil(LT)were selected.LD-based emulsion((83.74±1.23)%)had higher lipolysis degree than LT-based emulsion((74.47±1.16)%)when monitoring the GI tract of normal population as previously reported.Indigestion conditions seriously decreased the digestive degree of LT-based emulsion((40.23±2.48)%-(66.50±3.70)%)while showed less influence on LD-based emulsion((64.18±2.41)%-(81.85±3.45)%).As opposed to LT-based emulsion,LD-based emulsion exhibited preference for releasing unsaturated fatty acids(especially oleic acid andα-linolenic acid)due to their different glycerolipid compositions.LD-based emulsion showed potential for providing lipids and nutrients(including essential fatty acids)for lipid indigestion patients.展开更多
Self-microemulsifying drug delivery systems(SMEDDSs)have recently returned to the limelight of academia and industry due to their enormous potential in oral delivery of biomacromolecules.However,information on gastroi...Self-microemulsifying drug delivery systems(SMEDDSs)have recently returned to the limelight of academia and industry due to their enormous potential in oral delivery of biomacromolecules.However,information on gastrointestinal lipolysis and trans-epithelial transport of SMEDDS is rare.Aggregation-caused quenching(ACQ)fuorescent probes are utilized to visualize the in vivo behaviors of SMEDDSs,because the released probes during lipolysis are quenched upon contacting water.Two SMEDDSs composed of medium chain triglyceride and different ratios of Tween-80 and PEG-400 are set as models,meanwhile Neoral?was used as a control.The SMEDDS droplets reside in the digestive tract for as long as 24 h and obey frst order kinetic law of lipolysis.The increased chain length of the triglyceride decreases the lipolysis of the SMEDDSs.Ex vivo imaging of main tissues and histological examination confrm the trans-epithelial transportation of the SMEDDS droplets.Approximately 2%-4%of the given SMEDDSs are transported via the lymph route following epithelial uptake,while liver is the main termination.Caco-2 cell lines confrm the cellular uptake and trans-epithelial transport.In conclusion,a fraction of SMEDDSs can survive the lipolysis in the gastrointestinal tract,permeate across the epithelia,translocate via the lymph,and accumulate mainly in the liver.展开更多
Whey protein isolate coated astaxanthin-loaded liposomes were prepared in this work.The gastrointestinal digestive fate of whey protein isolate coated astaxanthin-loaded liposomes was evaluated in terms of particle si...Whey protein isolate coated astaxanthin-loaded liposomes were prepared in this work.The gastrointestinal digestive fate of whey protein isolate coated astaxanthin-loaded liposomes was evaluated in terms of particle size,size distribution,zeta potential,and morphology during in vitro digestion as a function of time.Analysis on the particle size and morphology of whey protein isolate coated astaxanthin-loaded liposomes showed that the majority of particles maintained spherical shape with a progressive increase of particle size after passage through the digestion.The zeta potential on whey protein isolate coated astaxanthin-loaded liposomes became highly negative after digestion.As compared in uncoated liposomes,the astaxanthin release in whey protein isolate coated liposomes was slower in simulated gastric fluid digestion,while was faster in simulated intestinal fluid digestion.Through in vitro digestion,the bioaccessibility of astaxanthin was improved significantly after whey protein isolate coating.It was also found that the whey protein isolate coating could protect liposomes against destruction and suppress the lateral mobility of pyrene,resulting in lower micropolarity and fluidity of liposomal membrane during the digestion.These findings may guide the potential application of whey protein isolate coated liposomes for improving the bioaccessibility and stability of astaxanthin in nutraceuticals and pharmaceutics.展开更多
Simiao Wan(SMW)is a traditional Chinese formula,including Atractylodis Rhizoma,Achyranthis Bidentatae Radix,Phellodendri Chinensis Cortex and Coicis Semen at the ratio of 1:1:2:2.It can be used to the treatment of dia...Simiao Wan(SMW)is a traditional Chinese formula,including Atractylodis Rhizoma,Achyranthis Bidentatae Radix,Phellodendri Chinensis Cortex and Coicis Semen at the ratio of 1:1:2:2.It can be used to the treatment of diabetes.However,its bioactive compounds and underlying mechanism are unclear.This study was designed to screen the antilipolytic fraction from SMW and investigate its therapeutic mechanisms on hepatic insulin resistance.Different fractions of SMW were prepared by membrane separation combined with macroporous resin and their antilipolytic activity was screened in fasted mice.The effects of 60%ethanol elution(ESMW)on lipolysis were investigated in 3T3-L1 adipocytes stimulated by palmitic acid(PA)and high fat diet(HFD)-fed mice.In our study,ESMW was the bioactive fraction responsible for the antilipolytic activity of SMW and 13 compounds were characterized from ESMW by UHPLC-QTOF-MS/MS.ESMW suppressed protein kinase A(PKA)-hormone-sensitive lipase(HSL)related lipolysis and increased AMP-activated protein kinase(AMPK)phosphorylation in PA challenged 3T3-L1 adipocytes.AMPKa knockdown abolished the inhibitory effects of ESMW on IL-6 and HSL pSer-660,revealing that the antilipolytic and anti-inflammatory activities of ESMW are AMPK dependent.Furthermore,ESMW ameliorated insulin resistance and suppressed lipolysis in HFD-fed mice.It inhibited diacylglycerol accumulation in the liver and inhibited hepatic gluconeogenesis.Conditional medium collected from ESMW-treated 3T3-L1 cells ameliorated insulin action on hepatic gluconeogenesis in liver cells,demonstrating that the antilipolytic activity contributed to ESMW beneficial effects on hepatic glucose production.In conclusion,ESMW,as the antilipolytic fraction of SMW,inhibited PKA-HSL related lipolysis by activating AMPK,inhibiting diacylglycerol(DAG)accumulation in the liver and thereby improving insulin resistance and hepatic gluconeogenesis.展开更多
OBJECTIVE: Traditional Korean Chungtaejeon (CTJ) tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to i...OBJECTIVE: Traditional Korean Chungtaejeon (CTJ) tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to investigate the effect and mechanism of CTJ tea extract on body weight gain using C57BL/6J-Lep ob/ob mice and 3T3-L1 adipocytes, respectively. METHODS: The effects of CTJ on cell viability, lipid accumulation, and expression of protein and mRNA were measured in 3T3-L1 adipocytes by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, oil red O staining, Western blotting, and reverse transcriptase-polymerase chain reaction analyses. C57BL6J-Lep ob/ob mice were administered with CTJ (200 or 400 mg/kg body weight) for ten weeks. Then, body weight, food intake, total cholesterol, and triglyceride were measured in ob/ob mice. RESULTS: CTJ tea extract treated at 250 wg/mL (CTJ250) significantly suppressed lipid accumulation in the differentiated 3T3-L1 adipocytes. Likewise, CTJ250 significantly decreased the protein expression of peroxisome proliferator-activated receptor Y (PPARy), CCJ^u~,T/enhancer-binding protein a, and adipocyte lipid- binding protein, and regulated the mRNA expression of PPART, sterol regulatory element-binding protein- lc gene, fatty acid synthase, adipocyte lipid-binding protein, hormone-sensitive lipase, carnitine palmitoyl transferase 1, cluster of differentiation 36, and acetyl-CoA carboxylase in the differentiated 3T3-L1 adipocytes. Mice administered with CTJ showed dose-dependent decrease in body weight gain, starting from week 4 of the experiment. CTJ tea extract administered at 400 mg/kg body weight significantly decreased fat mass, food efficacy ratio, and levels of plasma triglyceride and total cholesterol. CONCLUSION: CTJ attenuated weight gain in ob/ob mice and regulated the activity of the molecules involved in adipogenesis and lipolysis in 3T3-L1 adipocytes. CTJ is a potentially valuable herbal therapy for the prevention of obesity and/or obesity-related disorders.展开更多
With many advantages such as non-invasive,safe and quick effect,focused ultrasound lipolysis stands out among many fat-removing methods.However,during the whole process,the doctor needs to hold the ultrasound transduc...With many advantages such as non-invasive,safe and quick effect,focused ultrasound lipolysis stands out among many fat-removing methods.However,during the whole process,the doctor needs to hold the ultrasound transducer and press it on the patient’s skin with a large pressure for a long time;thus the probability of muscle and bone damage for doctors is greatly increased.To reduce the occurrence of doctors’occupational diseases,a depth camera-based ultrasonic lipolysis robot system is proposed to realize robot-assisted automatic ultrasonic lipolysis operation.The system is composed of RealSense depth camera,KUKA LBR Med seven-axis robotic arm,PC host,and ultrasonic lipolysis instrument.The whole operation includes two parts:preoperative planning and intraoperative operation.In preoperative planning,the treatment area is selected in the camera image by the doctor;then the system automatically plans uniformly distributed treatment points in the treatment area.At the same time,the skin normal vector is calculated to determine the end posture of the robot,so that the ultrasound transducer can be pressed down in the normal direction of skin.During the intraoperative operation,the robot is controlled to arrive at the treatment point in turn.Meanwhile,the patient’s movement can be detected by the depth camera,and the path of robot is adjusted in real time so that the robot can track the movement of patient,thereby ensuring the accuracy of the ultrasonic lipolysis operation.Finally,the human body model experiment is conducted.The results show that the maximum error of the robot operation is within 5mm,average error is 3.1mm,and the treatment points of the robot operation are more uniform than those of manual operation.Therefore,the system can replace the doctor and achieve autonomous ultrasonic lipolysis to reduce the doctor’s labor intensity.展开更多
Zinc alpha 2 glycoprotein(ZAG)is a 41 KDa secretory soluble glycoprotein found in different body fluids like the serum,saliva,sweat,breast milk,and urine.It is also found in tissues like the testis,epididymis,kidney,s...Zinc alpha 2 glycoprotein(ZAG)is a 41 KDa secretory soluble glycoprotein found in different body fluids like the serum,saliva,sweat,breast milk,and urine.It is also found in tissues like the testis,epididymis,kidney,spleen,liver,lungs,heart,and brain.ZAG is an adipokine with multiple roles,including lipid mobilization,modulating glucose metabolisms,improving insulin sensitivity,inhibiting tumor proliferation through RNAse activity,and suppressing inflammation.Low levels of zinc and ZAG are linked to metabolic syndrome and are also reported as potential biomarkers for diabetic nephropathy.Interestingly zinc has been found to regulate the binding of ZAG to fatty acids.Based on very few reports on the vitreous ZAG and based on its known functions,we speculate that ZAG has a potential role in diabetic retinopathy.In this article,we discuss the structural component of the protein,its secretion from various tissues,and its distribution in multiple tissues in normal and disease conditions,especially in diabetes and its complications.展开更多
Alcoholic liver disease(ALD) remains an important health problem worldwide. The disease spectrum is featured by early steatosis, steatohepatitis(steatosis with inflammatory cells infiltration and necrosis), with some ...Alcoholic liver disease(ALD) remains an important health problem worldwide. The disease spectrum is featured by early steatosis, steatohepatitis(steatosis with inflammatory cells infiltration and necrosis), with some individuals ultimately progressing to fibrosis/cirrhosis. Although the disease progression is well characterized, no effective therapies are currently available for the treatment in humans. The mechanisms underlying the initiation and progression of ALD are multifactorial and complex. Emerging evidence supports that adipose tissue dysfunction contributes to the pathogenesis of ALD. In the first part of this review, we discuss the mechanisms whereby chronic alcohol exposure contributed to adipose tissue dysfunction, including cell death, inflammation and insulin resistance. It has been long known that aberrant hepatic methionine metabolism is a major metabolic abnormality induced by chronic alcohol exposure and plays an etiological role in the pathogenesis of ALD. The recent studies in our group documented the similar metabolic effect of chronic alcohol drinking on methionine in adipose tissue. In the second part of this review, we also briefly discuss the recent research progress in the field with a focus on how abnormal methionine metabolism in adipose tissue contributes to adipose tissue dysfunction and liver damage.展开更多
It is widely known that branched chain amino acids(BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA(isoleucine, le...It is widely known that branched chain amino acids(BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA(isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including:(1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis.(2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.(3)Supplementation of leucine in the diet enhances meat quality in finishing pigs.(4) BCAA are beneficial for mammary health, milk quality and embryo growth.(5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.(6) BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood(decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.展开更多
Dietary supplementation with sea cucumber saponins(SCS)and exercise have been confirmed to be effective in pre-venting the development of obesity and its related diseases.However,the combined effectiveness of these in...Dietary supplementation with sea cucumber saponins(SCS)and exercise have been confirmed to be effective in pre-venting the development of obesity and its related diseases.However,the combined effectiveness of these interventions has not been explored.Here,we studied whether the beneficial influences of exercise could be further enhanced by dietary supplementation with SCS in high-fat diet-fed KM(Kunming)mice.Mice were randomly divided into four groups,including the high-fat diet group(HF),the SCS group(HF-S),the exercise group(HF-E),and the combination of dietary SCS and exercise group(HF-S+E).There were eight mice in every group.The results demonstrated that the combination of dietary SCS and exercise could synergistically reduce fat accumulation.In particular,white adipose tissue decreased by 63%in the HF-S+E group compared with that in the HF group.SCS supplementation with exercise also improved peripheral markers,such as serum parameters and hepatic TG levels.Further mechani-cal testing indicated that the combined effects of dietary SCS and exercise on inhibiting fat accumulation might be attributed to the inhibition of lipid synthesis in the liver and the activation of lipolysis in white adipose tissue to increase energy consumption.展开更多
Background: Persistent lactation,as the result of mammary cellular anabolism and secreting function,is dependent on substantial mobilization or catabolism of body reserves under nutritional deficiency.However,little i...Background: Persistent lactation,as the result of mammary cellular anabolism and secreting function,is dependent on substantial mobilization or catabolism of body reserves under nutritional deficiency.However,little is known about the biochemical mechanisms for nutrition-restricted lactating animals to simultaneously maintain the anabolism of mammary cells while catabolism of body reserves.In present study,lactating sows with restricted feed allowance(RFA)(n = 6),24% feed restriction compared with the control(CON) group(n = 6),were used as the nutrition-restricted model.Microdialysis and mammary venous cannulas methods were used to monitor postprandial dynamic changes of metabolites in adipose and mammary tissues.Results: At lactation d 28,the RFA group showed higher(P < 0.05) loss of body weight and backfat than the CON group.Compared with the CON group,the adipose tissue of the RFA group had higher(P < 0.05) extracellular glutamate and insulin levels,increased(P < 0.05) lipolysis related genes(HSL and ATGL) expression,and decreased(P < 0.05) glucose transport and metabolism related genes(VAMP8,PKLR and LDHB) expression.These results indicated that under nutritional restriction,reduced insulin-mediated glucose uptake and metabolism and increased lipolysis in adipose tissues was related to extracellular high glutamate concentration.As for mammary glands,compared with the CON group,the RFA group had up-regulated(P < 0.05) expression of Notch signaling ligand(DLL3) and receptors(NOTCH2 and NOTCH4),higher(P < 0.05) extracellular glutamate concentration,while expression of cell proliferation related genes and concentrations of most metabolites in mammary veins were not different(P > 0.05) between groups.Accordingly,piglet performance and milk yield did not differ(P > 0.05) between groups.It would appear that activation of Notch signaling and adequate supply of glutamate might assist mammogenesis.Conclusions: Mammary cell proliferation and catabolism of adipose tissues in nutrition-restricted lactating sows were associated with extracellular high glutamate levels.展开更多
To sustain the nutrient demands of rapid fetal growth,parturition,and milk synthesis,periparturient dairy cows mobilize adipose tissue fatty acid stores through lipolysis.This process induces an inflammatory response ...To sustain the nutrient demands of rapid fetal growth,parturition,and milk synthesis,periparturient dairy cows mobilize adipose tissue fatty acid stores through lipolysis.This process induces an inflammatory response within AT that is resolved as lactation progresses;however,excessive and protracted lipolysis compounds the risk for metabolic and inflammatory diseases.The suppression of lipolytic action and inflammation,along with amplification of adipogenesis and lipogenesis,serve as prospective therapeutic targets for improving the health of periparturient dairy cows.Generally,the activation of cannabinoid receptors by endocannabinoids enhances adipogenesis and lipogenesis,suppresses lipolysis,and increases appetite in mammals.These biological effects of activating the endocannabinoid system open the possibility of harnessing the endocannabinoid system through nutritional intervention in dairy herds as a potential tool to improve dairy cows’health,although much is still to be revealed in this context.This review summarizes the current knowledge surrounding the components of the endocannabinoid system,elaborates on the metabolic effects of its activation,and explores the potential to modulate its activity in periparturient dairy cows.展开更多
AIM To study complete dose-dependent effects of obestatin on lipolytic and glucose transport activities in human adipocyte preparations highly responsive to insulin.METHODS Adipocytes were prepared by liberase digesti...AIM To study complete dose-dependent effects of obestatin on lipolytic and glucose transport activities in human adipocyte preparations highly responsive to insulin.METHODS Adipocytes were prepared by liberase digestion from subcutaneous abdominal adipose tissue obtained from overweight subjects undergoing plastic surgery. The index of lipolytic activity was the glycerol released in the incubation medium, while glucose transport was assessed by [~3H]-2-deoxyglucose uptake assay.RESULTS When tested from 0.1 nmol/L to 1 μmol/L, obestatin did not stimulate glycerol release; it did not inhibit the lipolytic effect of isoprenaline and did not alter the insulin antilipolytic effect. Obestatin hardly activated glucose transport at 1 μmol/L only. Moreover, the obestatin stimulation effect was clearly lower than the threefold increase induced by insulin 100 nmol/L.CONCLUSION Low doses of obestatin cannot directly influence lipolysis and glucose uptake in human fat cells.展开更多
Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a...Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a bulk milk from the mixed herd of Saanen, Alpine, and Nubian goat breeds. LF cheeses were made using LF milk after cream separation. FFAs of all cheeses were extracted in diisoprophyl ether using polypropylene chromatography column, and FFA concentrations were quantified using a gas chromatograph equipped with a fused silica capillary column. Moisture, fat, protein contents (%) and pH of fresh LF and FF cheeses were: 55.1, 52.3;1.30, 25.6;35.7, 22.5;5.40, 5.42, respectively. The FFA contents (mg/g cheese) of fresh FF and LF cheeses prior to storage treatments for C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C18:1, and C18:2 were: 0.020, 0.072;0.070, 0.035;0.061, 0.055;0.181, 0.167;0.073, 0.047;0.174, 0.112;0.579, 0.152;0.308, 0.202;0.521, 0.174;and 0.057, 0.026, respectively. The respective FFA to total fatty acid ratios for 0, 1 and 3 months aged FF and LF cheeses were 8.44, 12.4;6.31, 16.91;12.03, 14.19. The LF cheeses generated more FFA than FF cheeses, while actual FFA content in FF cheese was significantly higher than in LF cheese. The FFA contents of LF cheese at 0, 1 and 3 months storage were 48.0, 96.8 and 36.4% of those of FF cheese, respectively. It was concluded LF cheese generated higher amount of FFA than FF cheese, although total FFA content was significantly (P<0.05) lower in LF cheese than in FF cheese.展开更多
基金This work was graciously supported by the Chinese National Natural Science Foundation(Grant 31901725 and 32201933)the Science and Technology Projects in Guangzhou(Grant 202201010170).
文摘Vaccarin,a flavonoid glycoside isolated from Vaccaria segetalis,is non-toxic to 3T3-L1 cells up to concentrations of 200μM.Accordingly,we investigated the effects of this natural product on adipogenesis and lipolysis in 3T3-L1 adipocytes.Our results revealed that vaccarin significantly inhibited lipid accumulation by suppressing the adipogenesis-related transcription factors peroxisome proliferator-activated receptorγ(PPARγ)and the CCAAT/enhancer-binding proteinα(C/EBPα).Specifically,lipid accumulation decreased by up to 27.7±2.7%when 3T3-L1 adipocytes were treated with a 10μM concentration of vaccarin.Mechanistic studies showed that the compound inhibited adipogenesis through activation of the Hedgehog(Hh)signaling pathway and so restoring Smo and Gli1 expression at an early stage of differentiation.In mature 3T3-L1 cells,vaccarin significantly increased the secretion of glycerol into the surrounding medium and thus indicating that it accelerated the degradation of triglycerides.In addition,vaccarin,was shown to enhance lipolysis through stimulation of the transcription levels of lipoprotein lipase,monoglycerides lipase,adipose triacylglyceride lipase,hormone-sensitive lipase and adipose differentiated-related protein.All told,vaccarin suppressed lipid accumulation and enhanced lipolysis during adipocyte differentiation by restoring Hh signaling.As such,it is a phytochemical capable of halting adipocyte hyperplasia and,thereby,ameliorating the effects of obesity.
文摘Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet ( 1.5% DHA ethyl ester/kg diet) for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.
基金supported in part by USDA-NIFA(Washington,DC)grants 2014-68004-21972 and 2015-67015-23207Department of Large Animal Clinical Sciences(East Lansing,MI)+2 种基金the Michigan State University Elwood Kirkpatrick Dairy Science Research Endowment(East Lansing,MI)Michigan Alliance for Animal Agriculture(East Lansing,Michigan)Michigan Animal Health Foundation
文摘Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughout the transition period is lipolysis from adipose tissue depots. During this time, plasma fatty acids serve as a source of calories mitigating the negative energy balance prompted by copious milk synthesis and limited dry matter intake.Past research has demonstrated that lipolysis in the adipose organ is a complex process that includes not only the activation of lipolytic pathways in response to neural, hormonal, or paracrine stimuli, but also important changes in the structure and cellular distribution of the tissue in a process known as adipose tissue remodeling. This process involves an inflammatory response with immune cell migration, proliferation of the cellular components of the stromal vascular fraction, and changes in the extracellular matrix. This review summarizes current knowledge on lipolysis in dairy cattle, expands on the new field of adipose tissue remodeling, and discusses how these biological processes affect transition cow health and productivity.
基金This study was financially supported by National Key R&D Program of China(grant No.2017YFD0400105)Natural Science Foundation of Beijing Municipality(grant No.6192009)Fengtai science and technology new star(grant No.KJXX201902).
文摘The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were studied.The degree of protein oxidation increased during the processes in two groups sausages,while the content of phospholipids decreased,neutral lipids and free fatty acids increased.The degree of protein oxidation,lipid oxidation and lipolysis in 4%NaCl content group was higher than those in 2%NaCl content group,while 4%NaCl content group has higher lipase activity.In conclusion,4%NaCl may facilitate the protein oxidation,lipid hydrolysis and oxidation in Chinese dry sausage,and the protein oxidation had strong correlation with lipid oxidation and lipolysis.The results could provide a basis for improving the technology of industrial production.
基金funded by the Science and Technology Committee of Shanghai Municipality (Nos.19430741400, 23S11901500,23ZR1413100, and 21430760800)the National Natural Science Foundation of China (Nos.81973247 and 82030107)。
文摘Lipid-based nanocarriers have staged a remarkable comeback in the oral delivery of proteins and peptides, but delivery efficiency is compromised by lipolysis. β-Lactoglobulin(β-lg) stabilized lipid nanoparticles, including nanoemulsions(NE@β-lg) and nanocapsules(NC@β-lg), were developed to enhance the oral absorption of insulin by slowing down lipolysis due to the protection from β-lg. Cremophor EL stabilized nanoemulsions(NE@Cre-EL) were prepared and set as a control. The lipid nanoparticles produced mild and sustained hypoglycemic effects, amounting to oral bioavailability of 3.0% ± 0.3%, 7.0% ± 1.1%, and7.7% ± 0.8% for NE@Cre-EL, NE@β-lg, and NC@β-lg, respectively. Aggregation-caused quenching(ACQ)probes enabled the identification of intact nanoparticles, which were used to investigate the in vivo and intracellular fates of the lipid nanoparticles. In vitro digestion/lipolysis and ex vivo imaging confirmed delayed lipolysis from β-lg stabilized lipid nanoparticles. NC@β-lg was more resistant to intestinal lipolysis than NE@β-lg due to the Ca^(2+)-induced crosslinking. Live imaging revealed the transepithelial transport of intact nanoparticles and their accumulation in the liver. Cellular studies confirmed the uptake of intact nanoparticles. Slowing down lipolysis via food proteins represents a good strategy to enhance the oral absorption of lipid nanoparticles and thus co-formulated biomacromolecules.
基金supported by the National Nature Science Foundation of China(NSFC,Grant Number:31772863,32072989).
文摘Docosahexaenoic acid(DHA)is a biologically active fatty acid that reduces the accumulation of lipids.However,the molecular mechanism underlying this process,particularly in fish,is not well understood.Recent studies show that endoplasmic reticulum(ER)stress triggers the activation of the unfolded protein response,which has been revealed to play an essential role in lipid metabolism.In this study,we explored the effect of DHA on ER stress and investigated the potential molecular mechanisms underlying DHA-induced adipocyte lipolysis in grass carp(Ctenopharyngodon idella)both in vivo and in vitro.We found that DHA remarkably reduced the triglyceride content,increased the secretion of glycerol,pro-moted lipolysis in adipocytes and evoked ER stress,whereas inhibiting ER stress using 4-phenyl butyric acid(4-PBA)inhibited the effects of DHA(P<0.05).These results implied that ER stress potentially participates in DHA-induced adipocyte lipolysis.Additionally,STF-083010,a specific inositol-requiring enzyme 1a(IRE1a)-inhibitor,attenuated the effects of DHA on lipolysis,demonstrating that IRE1a and X-box binding protein 1 potentially participate in DHA-induced lipolysis.DHA also activated the cyclic adenosine monophosphate(cAMP)-dependent protein kinase A(PKA)pathway by increasing the level of cAMP and activating the PKA enzyme(P<0.05).Nevertheless,H89,a PKA inhibitor,weakened DHA-induced lipolysis by inhibiting the cAMP/PKA signaling pathway.Furthermore,inhibiting ER stress us-ing 4-PBA also inhibited lipolysis and alleviated DHA-induced activation of the cAMP/PKA signaling pathway,suggesting that ER stress may participate in DHA-induced lipolysis through the activation of the cAMP/PKA signaling pathway.Our data illustrate that DHA supplementation can be a promising nutritional strategy for ameliorating lipid accumulation in grass carp.The present study elucidated the molecular mechanism for DHA-induced lipolysis in grass carp adipocytes and emphasized the impor-tance of ER stress and the cAMP/PKA pathway in DHA-induced lipolysis.These results deepen our un-derstanding of ameliorating lipids deposition in freshwater fish by targeting DHA.
基金National Key R&D Program of China(2022YFC2805100)National Science Fund for Key Program of National Natural Science Foundation of China(31930084)+3 种基金National Science Fund for Distinguished Young Scholars of China(31725022)China Agriculture Research System(CARS-18-ZJ0503)Guangdong Provincial Key R&D Programme(2022B0202010002)Science and Technology Innovation Project of Foshan City(FS0AAKJ919-4402-0013)。
文摘The in vitro digestion models mimicking the gastrointestinal(GI)tract of general population and lipid indigestion patients(with lower levels of bile salts or pancreatic lipase)were selected to investigate whether diacylglycerols(DAGs)are potential good lipid sources for these patients.Linseed oil-based DAG(LD)and linseed oil(LT)were selected.LD-based emulsion((83.74±1.23)%)had higher lipolysis degree than LT-based emulsion((74.47±1.16)%)when monitoring the GI tract of normal population as previously reported.Indigestion conditions seriously decreased the digestive degree of LT-based emulsion((40.23±2.48)%-(66.50±3.70)%)while showed less influence on LD-based emulsion((64.18±2.41)%-(81.85±3.45)%).As opposed to LT-based emulsion,LD-based emulsion exhibited preference for releasing unsaturated fatty acids(especially oleic acid andα-linolenic acid)due to their different glycerolipid compositions.LD-based emulsion showed potential for providing lipids and nutrients(including essential fatty acids)for lipid indigestion patients.
基金supported by the National Natural Science Foundation of China(Nos.82030107,81973247,81872815,81872826,and 81690263)Science and Technology Commission of Shanghai Municipality(Nos.19XD1400300,19430741400,and 19410761200,China)。
文摘Self-microemulsifying drug delivery systems(SMEDDSs)have recently returned to the limelight of academia and industry due to their enormous potential in oral delivery of biomacromolecules.However,information on gastrointestinal lipolysis and trans-epithelial transport of SMEDDS is rare.Aggregation-caused quenching(ACQ)fuorescent probes are utilized to visualize the in vivo behaviors of SMEDDSs,because the released probes during lipolysis are quenched upon contacting water.Two SMEDDSs composed of medium chain triglyceride and different ratios of Tween-80 and PEG-400 are set as models,meanwhile Neoral?was used as a control.The SMEDDS droplets reside in the digestive tract for as long as 24 h and obey frst order kinetic law of lipolysis.The increased chain length of the triglyceride decreases the lipolysis of the SMEDDSs.Ex vivo imaging of main tissues and histological examination confrm the trans-epithelial transportation of the SMEDDS droplets.Approximately 2%-4%of the given SMEDDSs are transported via the lymph route following epithelial uptake,while liver is the main termination.Caco-2 cell lines confrm the cellular uptake and trans-epithelial transport.In conclusion,a fraction of SMEDDSs can survive the lipolysis in the gastrointestinal tract,permeate across the epithelia,translocate via the lymph,and accumulate mainly in the liver.
基金financially supported by National Natural Science Foundation of China(32001738)the Key Scientific Research Projects of Higher Education Institutions of Henan Province in China(21A550006)+3 种基金Natural Science Innovation Fund Support Plan of Henan University of Technology(2020ZKCJ13)Young Backbone Teacher Cultivation Program of Henan University of Technology,High-level Talents Fund of Henan University of Technology(2018BS049)Key Scientific and Technological Project of Henan Province(202102310006)National Innovation and Entrepreneurship Training Program for College Students(202010463003).
文摘Whey protein isolate coated astaxanthin-loaded liposomes were prepared in this work.The gastrointestinal digestive fate of whey protein isolate coated astaxanthin-loaded liposomes was evaluated in terms of particle size,size distribution,zeta potential,and morphology during in vitro digestion as a function of time.Analysis on the particle size and morphology of whey protein isolate coated astaxanthin-loaded liposomes showed that the majority of particles maintained spherical shape with a progressive increase of particle size after passage through the digestion.The zeta potential on whey protein isolate coated astaxanthin-loaded liposomes became highly negative after digestion.As compared in uncoated liposomes,the astaxanthin release in whey protein isolate coated liposomes was slower in simulated gastric fluid digestion,while was faster in simulated intestinal fluid digestion.Through in vitro digestion,the bioaccessibility of astaxanthin was improved significantly after whey protein isolate coating.It was also found that the whey protein isolate coating could protect liposomes against destruction and suppress the lateral mobility of pyrene,resulting in lower micropolarity and fluidity of liposomal membrane during the digestion.These findings may guide the potential application of whey protein isolate coated liposomes for improving the bioaccessibility and stability of astaxanthin in nutraceuticals and pharmaceutics.
基金supported by the National Key R&D Program of China(Nos.2018YFC1704500 and 2018YFC 1704503)the National Natural Science Foundation of China(Nos.82074080 and 81773877)the Natural Science Foundation of Jiangsu Province(No.BK20181328).
文摘Simiao Wan(SMW)is a traditional Chinese formula,including Atractylodis Rhizoma,Achyranthis Bidentatae Radix,Phellodendri Chinensis Cortex and Coicis Semen at the ratio of 1:1:2:2.It can be used to the treatment of diabetes.However,its bioactive compounds and underlying mechanism are unclear.This study was designed to screen the antilipolytic fraction from SMW and investigate its therapeutic mechanisms on hepatic insulin resistance.Different fractions of SMW were prepared by membrane separation combined with macroporous resin and their antilipolytic activity was screened in fasted mice.The effects of 60%ethanol elution(ESMW)on lipolysis were investigated in 3T3-L1 adipocytes stimulated by palmitic acid(PA)and high fat diet(HFD)-fed mice.In our study,ESMW was the bioactive fraction responsible for the antilipolytic activity of SMW and 13 compounds were characterized from ESMW by UHPLC-QTOF-MS/MS.ESMW suppressed protein kinase A(PKA)-hormone-sensitive lipase(HSL)related lipolysis and increased AMP-activated protein kinase(AMPK)phosphorylation in PA challenged 3T3-L1 adipocytes.AMPKa knockdown abolished the inhibitory effects of ESMW on IL-6 and HSL pSer-660,revealing that the antilipolytic and anti-inflammatory activities of ESMW are AMPK dependent.Furthermore,ESMW ameliorated insulin resistance and suppressed lipolysis in HFD-fed mice.It inhibited diacylglycerol accumulation in the liver and inhibited hepatic gluconeogenesis.Conditional medium collected from ESMW-treated 3T3-L1 cells ameliorated insulin action on hepatic gluconeogenesis in liver cells,demonstrating that the antilipolytic activity contributed to ESMW beneficial effects on hepatic glucose production.In conclusion,ESMW,as the antilipolytic fraction of SMW,inhibited PKA-HSL related lipolysis by activating AMPK,inhibiting diacylglycerol(DAG)accumulation in the liver and thereby improving insulin resistance and hepatic gluconeogenesis.
基金supported by the Technology Development Program for Agriculture and Forestry, Ministry for Agriculture, Forestiy and Fisheries, Republic of Korea
文摘OBJECTIVE: Traditional Korean Chungtaejeon (CTJ) tea is a type of fermented tea, which has received increasing attention in recent years because of its purported health benefits. The present study was designed to investigate the effect and mechanism of CTJ tea extract on body weight gain using C57BL/6J-Lep ob/ob mice and 3T3-L1 adipocytes, respectively. METHODS: The effects of CTJ on cell viability, lipid accumulation, and expression of protein and mRNA were measured in 3T3-L1 adipocytes by using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, oil red O staining, Western blotting, and reverse transcriptase-polymerase chain reaction analyses. C57BL6J-Lep ob/ob mice were administered with CTJ (200 or 400 mg/kg body weight) for ten weeks. Then, body weight, food intake, total cholesterol, and triglyceride were measured in ob/ob mice. RESULTS: CTJ tea extract treated at 250 wg/mL (CTJ250) significantly suppressed lipid accumulation in the differentiated 3T3-L1 adipocytes. Likewise, CTJ250 significantly decreased the protein expression of peroxisome proliferator-activated receptor Y (PPARy), CCJ^u~,T/enhancer-binding protein a, and adipocyte lipid- binding protein, and regulated the mRNA expression of PPART, sterol regulatory element-binding protein- lc gene, fatty acid synthase, adipocyte lipid-binding protein, hormone-sensitive lipase, carnitine palmitoyl transferase 1, cluster of differentiation 36, and acetyl-CoA carboxylase in the differentiated 3T3-L1 adipocytes. Mice administered with CTJ showed dose-dependent decrease in body weight gain, starting from week 4 of the experiment. CTJ tea extract administered at 400 mg/kg body weight significantly decreased fat mass, food efficacy ratio, and levels of plasma triglyceride and total cholesterol. CONCLUSION: CTJ attenuated weight gain in ob/ob mice and regulated the activity of the molecules involved in adipogenesis and lipolysis in 3T3-L1 adipocytes. CTJ is a potentially valuable herbal therapy for the prevention of obesity and/or obesity-related disorders.
基金the National Natural Science Foundation of China(Nos.61973211,51911540479 and M-0221)the Research Project of Institute of Medical Robotics of Shanghai Jiao Tong Universitythe Project of Science and Technology Commission of Shanghai Municipality(No.20DZ2220400)。
文摘With many advantages such as non-invasive,safe and quick effect,focused ultrasound lipolysis stands out among many fat-removing methods.However,during the whole process,the doctor needs to hold the ultrasound transducer and press it on the patient’s skin with a large pressure for a long time;thus the probability of muscle and bone damage for doctors is greatly increased.To reduce the occurrence of doctors’occupational diseases,a depth camera-based ultrasonic lipolysis robot system is proposed to realize robot-assisted automatic ultrasonic lipolysis operation.The system is composed of RealSense depth camera,KUKA LBR Med seven-axis robotic arm,PC host,and ultrasonic lipolysis instrument.The whole operation includes two parts:preoperative planning and intraoperative operation.In preoperative planning,the treatment area is selected in the camera image by the doctor;then the system automatically plans uniformly distributed treatment points in the treatment area.At the same time,the skin normal vector is calculated to determine the end posture of the robot,so that the ultrasound transducer can be pressed down in the normal direction of skin.During the intraoperative operation,the robot is controlled to arrive at the treatment point in turn.Meanwhile,the patient’s movement can be detected by the depth camera,and the path of robot is adjusted in real time so that the robot can track the movement of patient,thereby ensuring the accuracy of the ultrasonic lipolysis operation.Finally,the human body model experiment is conducted.The results show that the maximum error of the robot operation is within 5mm,average error is 3.1mm,and the treatment points of the robot operation are more uniform than those of manual operation.Therefore,the system can replace the doctor and achieve autonomous ultrasonic lipolysis to reduce the doctor’s labor intensity.
基金the Indian Council of Medical Research(ICMR—(5/4/6/1/OPH/2020-NCD-II)).
文摘Zinc alpha 2 glycoprotein(ZAG)is a 41 KDa secretory soluble glycoprotein found in different body fluids like the serum,saliva,sweat,breast milk,and urine.It is also found in tissues like the testis,epididymis,kidney,spleen,liver,lungs,heart,and brain.ZAG is an adipokine with multiple roles,including lipid mobilization,modulating glucose metabolisms,improving insulin sensitivity,inhibiting tumor proliferation through RNAse activity,and suppressing inflammation.Low levels of zinc and ZAG are linked to metabolic syndrome and are also reported as potential biomarkers for diabetic nephropathy.Interestingly zinc has been found to regulate the binding of ZAG to fatty acids.Based on very few reports on the vitreous ZAG and based on its known functions,we speculate that ZAG has a potential role in diabetic retinopathy.In this article,we discuss the structural component of the protein,its secretion from various tissues,and its distribution in multiple tissues in normal and disease conditions,especially in diabetes and its complications.
基金Supported by National Institutes of Health NIAAA,No.R01AA017442
文摘Alcoholic liver disease(ALD) remains an important health problem worldwide. The disease spectrum is featured by early steatosis, steatohepatitis(steatosis with inflammatory cells infiltration and necrosis), with some individuals ultimately progressing to fibrosis/cirrhosis. Although the disease progression is well characterized, no effective therapies are currently available for the treatment in humans. The mechanisms underlying the initiation and progression of ALD are multifactorial and complex. Emerging evidence supports that adipose tissue dysfunction contributes to the pathogenesis of ALD. In the first part of this review, we discuss the mechanisms whereby chronic alcohol exposure contributed to adipose tissue dysfunction, including cell death, inflammation and insulin resistance. It has been long known that aberrant hepatic methionine metabolism is a major metabolic abnormality induced by chronic alcohol exposure and plays an etiological role in the pathogenesis of ALD. The recent studies in our group documented the similar metabolic effect of chronic alcohol drinking on methionine in adipose tissue. In the second part of this review, we also briefly discuss the recent research progress in the field with a focus on how abnormal methionine metabolism in adipose tissue contributes to adipose tissue dysfunction and liver damage.
基金supported by the National Key Basic Research Program(S.Y.Q.,Grant Number 2012CB124704)
文摘It is widely known that branched chain amino acids(BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA(isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including:(1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis.(2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.(3)Supplementation of leucine in the diet enhances meat quality in finishing pigs.(4) BCAA are beneficial for mammary health, milk quality and embryo growth.(5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.(6) BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood(decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.
基金This work was supported by the National Key R&D Pro-gram of China(No.2018YFD0901103)National Natural Science Foundation of China(Nos.31901688 and 31571771).
文摘Dietary supplementation with sea cucumber saponins(SCS)and exercise have been confirmed to be effective in pre-venting the development of obesity and its related diseases.However,the combined effectiveness of these interventions has not been explored.Here,we studied whether the beneficial influences of exercise could be further enhanced by dietary supplementation with SCS in high-fat diet-fed KM(Kunming)mice.Mice were randomly divided into four groups,including the high-fat diet group(HF),the SCS group(HF-S),the exercise group(HF-E),and the combination of dietary SCS and exercise group(HF-S+E).There were eight mice in every group.The results demonstrated that the combination of dietary SCS and exercise could synergistically reduce fat accumulation.In particular,white adipose tissue decreased by 63%in the HF-S+E group compared with that in the HF group.SCS supplementation with exercise also improved peripheral markers,such as serum parameters and hepatic TG levels.Further mechani-cal testing indicated that the combined effects of dietary SCS and exercise on inhibiting fat accumulation might be attributed to the inhibition of lipid synthesis in the liver and the activation of lipolysis in white adipose tissue to increase energy consumption.
基金support from the National Natural Science Fundation of China(31472109)
文摘Background: Persistent lactation,as the result of mammary cellular anabolism and secreting function,is dependent on substantial mobilization or catabolism of body reserves under nutritional deficiency.However,little is known about the biochemical mechanisms for nutrition-restricted lactating animals to simultaneously maintain the anabolism of mammary cells while catabolism of body reserves.In present study,lactating sows with restricted feed allowance(RFA)(n = 6),24% feed restriction compared with the control(CON) group(n = 6),were used as the nutrition-restricted model.Microdialysis and mammary venous cannulas methods were used to monitor postprandial dynamic changes of metabolites in adipose and mammary tissues.Results: At lactation d 28,the RFA group showed higher(P < 0.05) loss of body weight and backfat than the CON group.Compared with the CON group,the adipose tissue of the RFA group had higher(P < 0.05) extracellular glutamate and insulin levels,increased(P < 0.05) lipolysis related genes(HSL and ATGL) expression,and decreased(P < 0.05) glucose transport and metabolism related genes(VAMP8,PKLR and LDHB) expression.These results indicated that under nutritional restriction,reduced insulin-mediated glucose uptake and metabolism and increased lipolysis in adipose tissues was related to extracellular high glutamate concentration.As for mammary glands,compared with the CON group,the RFA group had up-regulated(P < 0.05) expression of Notch signaling ligand(DLL3) and receptors(NOTCH2 and NOTCH4),higher(P < 0.05) extracellular glutamate concentration,while expression of cell proliferation related genes and concentrations of most metabolites in mammary veins were not different(P > 0.05) between groups.Accordingly,piglet performance and milk yield did not differ(P > 0.05) between groups.It would appear that activation of Notch signaling and adequate supply of glutamate might assist mammogenesis.Conclusions: Mammary cell proliferation and catabolism of adipose tissues in nutrition-restricted lactating sows were associated with extracellular high glutamate levels.
基金This project was funded by the US-Israel Binational Agricultural Research and Development Fund(Grant IS-5167-19)MNS was supported in part by the USDA National Institute for Food and Agriculture(Washington,DC,USA)competitive project 2019-67015-29443.
文摘To sustain the nutrient demands of rapid fetal growth,parturition,and milk synthesis,periparturient dairy cows mobilize adipose tissue fatty acid stores through lipolysis.This process induces an inflammatory response within AT that is resolved as lactation progresses;however,excessive and protracted lipolysis compounds the risk for metabolic and inflammatory diseases.The suppression of lipolytic action and inflammation,along with amplification of adipogenesis and lipogenesis,serve as prospective therapeutic targets for improving the health of periparturient dairy cows.Generally,the activation of cannabinoid receptors by endocannabinoids enhances adipogenesis and lipogenesis,suppresses lipolysis,and increases appetite in mammals.These biological effects of activating the endocannabinoid system open the possibility of harnessing the endocannabinoid system through nutritional intervention in dairy herds as a potential tool to improve dairy cows’health,although much is still to be revealed in this context.This review summarizes the current knowledge surrounding the components of the endocannabinoid system,elaborates on the metabolic effects of its activation,and explores the potential to modulate its activity in periparturient dairy cows.
文摘AIM To study complete dose-dependent effects of obestatin on lipolytic and glucose transport activities in human adipocyte preparations highly responsive to insulin.METHODS Adipocytes were prepared by liberase digestion from subcutaneous abdominal adipose tissue obtained from overweight subjects undergoing plastic surgery. The index of lipolytic activity was the glycerol released in the incubation medium, while glucose transport was assessed by [~3H]-2-deoxyglucose uptake assay.RESULTS When tested from 0.1 nmol/L to 1 μmol/L, obestatin did not stimulate glycerol release; it did not inhibit the lipolytic effect of isoprenaline and did not alter the insulin antilipolytic effect. Obestatin hardly activated glucose transport at 1 μmol/L only. Moreover, the obestatin stimulation effect was clearly lower than the threefold increase induced by insulin 100 nmol/L.CONCLUSION Low doses of obestatin cannot directly influence lipolysis and glucose uptake in human fat cells.
文摘Differences in free fatty acid (FFA) compositions between low-fat (LF) and full-fat (FF: whole milk) goat cheeses were evaluated during 3 months at 4oC refrigeration. The two types of cheeses were manufactured using a bulk milk from the mixed herd of Saanen, Alpine, and Nubian goat breeds. LF cheeses were made using LF milk after cream separation. FFAs of all cheeses were extracted in diisoprophyl ether using polypropylene chromatography column, and FFA concentrations were quantified using a gas chromatograph equipped with a fused silica capillary column. Moisture, fat, protein contents (%) and pH of fresh LF and FF cheeses were: 55.1, 52.3;1.30, 25.6;35.7, 22.5;5.40, 5.42, respectively. The FFA contents (mg/g cheese) of fresh FF and LF cheeses prior to storage treatments for C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C18:1, and C18:2 were: 0.020, 0.072;0.070, 0.035;0.061, 0.055;0.181, 0.167;0.073, 0.047;0.174, 0.112;0.579, 0.152;0.308, 0.202;0.521, 0.174;and 0.057, 0.026, respectively. The respective FFA to total fatty acid ratios for 0, 1 and 3 months aged FF and LF cheeses were 8.44, 12.4;6.31, 16.91;12.03, 14.19. The LF cheeses generated more FFA than FF cheeses, while actual FFA content in FF cheese was significantly higher than in LF cheese. The FFA contents of LF cheese at 0, 1 and 3 months storage were 48.0, 96.8 and 36.4% of those of FF cheese, respectively. It was concluded LF cheese generated higher amount of FFA than FF cheese, although total FFA content was significantly (P<0.05) lower in LF cheese than in FF cheese.