Low-density lipoprotein receptor-related protein 2(LRP2)is required for lipid export in the midgut of the migratory locust,Locusta migratoria

Low-density lipoprotein receptor-related protein 2(LRP2)is a multifunctional endocytic receptor expressed in epithelial cells.In mammals,it acts as an endocytic receptor that mediates the cellular uptake of cholesterol-containing apolipoproteins to maintain lipid homeostasis.However,little is known about the role of LRP2 in lipid homeostasis in insects.In the present study,we investigated the function of LRP2 in the migratory locust Locusta migratoria(LmLRP2).The mRNA of LmLRP2 is widely distributed in various tissues,including integument,wing pads,foregut,midgut,hindgut,Malpighian tubules and fat body,and the amounts of LmLRP2 transcripts decreased gradually in the early stages and then increased in the late stages before ecdysis during the nymphal developmental stage.Fluorescence immunohistochemistry revealed that the LmLRP2 protein is mainly located in cellular membranes of the midgut and hindgut.Using RNAi to silence LmLRP2 caused molting defects in nymphs(more than 60%),and the neutral lipid was found to accumulate in the midgut and surface of the integument,but not in the fat body,of dsLmLRP2-treated nymphs.The results of a lipidomics analysis showed that the main components of lipids(diglyceride and triglyceride)were significantly increased in the midgut,but decreased in the fat body and hemolymph.Furthermore,the content of total triglyceride was significantly increased in the midgut,but markedly decreased in the fat body and hemolymph in dsLmLRP2-injected nymphs.Our results indicate that LmLRP2 is located in the cellular membranes of midgut cells,and is required for lipid export from the midgut to the hemolymphand fat body in locusts.

Overexpression of low-density lipoprotein receptor prevents neurotoxic polarization of astrocytes via inhibiting NLRP3 inflammasome activation in experimental ischemic stroke

Neurotoxic astrocytes are a promising therapeutic target for the attenuation of cerebral ischemia/reperfusion injury.Low-density lipoprotein receptor,a classic cholesterol regulatory receptor,has been found to inhibit NLR family pyrin domain containing protein 3(NLRP3)inflammasome activation in neurons following ischemic stroke and to suppress the activation of microglia and astrocytes in individuals with Alzheimer’s disease.However,little is known about the effects of low-density lipoprotein receptor on astrocytic activation in ischemic stroke.To address this issue in the present study,we examined the mechanisms by which low-density lipoprotein receptor regulates astrocytic polarization in ischemic stroke models.First,we examined low-density lipoprotein receptor expression in astrocytes via immunofluorescence staining and western blotting analysis.We observed significant downregulation of low-density lipoprotein receptor following middle cerebral artery occlusion reperfusion and oxygen-glucose deprivation/reoxygenation.Second,we induced the astrocyte-specific overexpression of low-density lipoprotein receptor using astrocyte-specific adeno-associated virus.Low-density lipoprotein receptor overexpression in astrocytes improved neurological outcomes in middle cerebral artery occlusion mice and reversed neurotoxic astrocytes to create a neuroprotective phenotype.Finally,we found that the overexpression of low-density lipoprotein receptor inhibited NLRP3 inflammasome activation in oxygen-glucose deprivation/reoxygenation injured astrocytes and that the addition of nigericin,an NLRP3 agonist,restored the neurotoxic astrocyte phenotype.These findings suggest that low-density lipoprotein receptor could inhibit the NLRP3-meidiated neurotoxic polarization of astrocytes and that increasing low-density lipoprotein receptor in astrocytes might represent a novel strategy for treating cerebral ischemic stroke.

Nε-(carboxymethyl)lysine promotes lipid uptake of macrophage via cluster of differentiation 36 and receptor for advanced glycation end products

BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.

Effects of Ovariectomy and 17β-Estradiol Replacement on the Activity of Dopamine D2 Receptors in the Selection of Macronutrients Carbohydrates, Lipids and Proteins in Females Rats

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.

Oxidized low-density lipoprotein receptor 1:a novel potential therapeutic target for intracerebral hemorrhage

Oxidized low-density lipoprotein receptor 1(OLR1)is upregulated in neurons and participates in hypertension-induced neuronal apoptosis.OLR1 deletion exerts protective effects on cerebral damage induced by hypertensive-induced stroke.Therefore,OLR1 is likely involved in the progress of intracerebral hemorrhage.In this study,we examined the potential role of OLR1 in intracerebral hemorrhage using a rat model.OLR1 small interfering RNA(10μL;50 pmol/μL)was injected into the right basal ganglia to knock down OLR1.Twenty-four hours later,0.5 U collagenase type VII was injected to induce intracerebral hemorrhage.We found that knockdown of OLR1 attenuated neurological behavior impairment in rats with intracerebral hemorrhage and reduced hematoma,neuron loss,inflammatory reaction,and oxidative stress in rat brain tissue.We also found that silencing of OLR1 suppressed ferroptosis induced by intracerebral hemorrhage and the p38 signaling pathway.Therefore,silencing OLR1 exhibits protective effects against secondary injury of intracerebral hemorrhage.These findings suggest that OLR1 may be a novel potential therapeutic target for intracerebral hemorrhage.

RARRES2's impact on lipid metabolism in triplenegative breast cancer:a pathway to brain metastasis

Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical Research investigated the role of retinoic acid receptor responder 2(RARRES2)in regulating lipid metabolism in BCBrM,highlighting the clinical relevance of alterations in lipid metabolites,such as phosphatidylcholine(PC)and triacylglycerols(TAGs),by RARRES2 through the modulation of phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway.This commentary aims to elaborate on the key findings and their relevance to the field.

牛羊毛发中3种β-受体激动剂药物残留测定的EMR-Lipid方法研究

旨在建立一种以牛羊毛发为靶标结合强化基质去除技术(EMR-Lipid)对3种β-受体激动剂药物(克伦特罗、莱克多巴胺、沙丁胺醇)残留量进行测定的方法。毛发样品经选取、清洗、干燥、研磨后,经酸水解和氨化乙腈提取后加入到Captiva EMR-Lipid净化柱,加入石墨化炭黑(GCB)进行净化,过滤后用高效液相色谱-串联质谱仪进行测定,采用正离子(ESI^(+))扫描,多反应监测(MRM)模式进行分析,内标法定量。结果显示:待测药物在0.1~100 ng/mL的浓度范围内具有良好的线性相关性,相关系数R2≥0.995;方法检测限(LOD)为0.2μg/kg,定量限(LOQ)为0.5μg/kg;药物在1、20、100μg/kg添加浓度下,平均回收率为70%~120%,相对标准偏差≤20%。该方法取样方便,前处理步骤少,灵敏度和精密度高,符合残留检测要求,为动物性产品中β-受体激动剂类药物残留量测定提供了参考。

Polymorphisms of the Vitamin D Receptor Gene and SexDifferential Associations with Lipid Profiles in Chinese Han Adults

Objective To explore the association of single nucleotide polymorphisms(SNPs)of the vitamin D receptor gene(VDR)with circulating lipids considering gender differences.Methods Of the Han Chinese adults recruited from a health examination center for inclusion in the study,the circulating lipids,25-hydroxyvitamin D(25OHD),and other parameters were measured.The VDR SNPs of Cdx2(rs11568820),Fok1(rs2228570),Apa1(rs7975232),and Taq1(rs731236)were genotyped with a qPCR test using blood DNA samples,and their associations with lipids were analyzed using logistic regression.Results In the female participants(n=236 with dyslipidemia and 888 without dyslipidemia),multiple genotype models of Fok1 indicated a positive correlation of B(not A)alleles with LDLC level(P<0.05).In the male participants(n=299 with dyslipidemia and 564 without dyslipidemia),the recessive model of Cdx2 and the additive and recessive models of Fok1 differed(P<0.05)between the HDLC-classified subgroups,respectively,and Fok1 BB and Cdx2 TT presented interactions with 25OHD in the negative associations with HDLC(P<0.05).Conclusion In the Chinese Han adults included in the study,the Fok1 B-allele of VDR was associated with higher LDLC in females,and the Fok1 B-allele and the Cdx2 T-allele of VDR were associated with lower HDLC in males.The interaction of VD and Fok1 BB or Cdx2 TT in males synergistically decreased HDLC levels.

Regenerating gene 4 promotes chemoresistance of colorectal cancer by affecting lipid droplet synthesis and assembly

BACKGROUND Regenerating gene 4(REG4)has been proved to be carcinogenic in some cancers,but its manifestation and possible carcinogenic mechanisms in colorectal cancer(CRC)have not yet been elucidated.Our previous study found that the drug resistance of CRC cells may be closely linked to their fat metabolism.AIM To explore the role of REG4 in CRC and its association with lipid droplet formation and chemoresistance.METHODS We conducted a meta-analysis and bioinformatics and pathological analyses of REG4 expression in CRC.The effects of REG4 on the phenotypes and related protein expression were also investigated in CRC cells.We detected the impacts of REG4 on the chemoresistance and lipid droplet formation in CRC cells.Finally,we analyzed how REG4 regulated the transcription and proteasomal degradation of lipogenic enzymes in CRC cells.RESULTS Compared to normal mucosa,REG4 mRNA expression was high in CRC(P<0.05)but protein expression was low.An inverse correlation existed between lymph node and distant metastases,tumor-node-metastasis staging or short overall survival and REG4 mRNA overexpression(P<0.05),but vice versa for REG4 protein expression.REG4-related genes included:Chemokine activity;taste receptors;protein-DNA and DNA packing complexes;nucleosomes and chromatin;generation of second messenger molecules;programmed cell death signals;epigenetic regulation and DNA methylation;transcription repression and activation by DNA binding;insulin signaling pathway;sugar metabolism and transfer;and neurotransmitter receptors(P<0.05).REG4 exposure or overexpression promoted proliferation,antiapoptosis,migration,and invasion of DLD-1 cells in an autocrine or paracrine manner by activating the epidermal growth factor receptor-phosphoinositide 3-kinase-Akt-nuclear factor-κB pathway.REG4 was involved in chemoresistance not through de novo lipogenesis,but lipid droplet assembly.REG4 inhibited the transcription of acetyl-CoA carboxylase 1(ACC1)and ATP-citrate lyase(ACLY)by disassociating the complex formation of anti-acetyl(AC)-acetyl-histone 3-AC-histone 4-inhibitor of growth protein-5-si histone deacetylase;-sterol-regulatory element binding protein 1 in their promoters and induced proteasomal degradation of ACC1 or ACLY.CONCLUSION REG4 may be involved in chemoresistance through lipid droplet assembly.REG4 reduces expression of de novo lipid synthesis key enzymes by inhibiting transcription and promoting ubiquitination-mediated proteasomal degradation.

"Smart fats", healthy brain and function of lipid-sensing NMDA receptors

NMDA receptor channels play a significant role in learning and memory and their dysfunction can cause neuronal cell death leading to dementia. Research had shown that lipids change the risk for dementia, especially some omega-3 lipids appear to lower Alz-heimer’s risk, yet only limited research exists on the modulation of NMDA receptor channels by lipids. Here we review recent literature concerning molecular determinants that influence the NMDA receptor channel gating via membrane lipids and fatty acids with profound significance for understanding how altered NMDA signalling leads to neuronal cell death linked to age-related dementia’s. Future discovery of lipid-like modulators of NMDA receptor function offer the potential for the development of new bioceu-ticals and affordable nutritional supplements to combat neuronal degeneration as well as to promote well being and healthy aging.

Relationship between the low density lipoprotein receptor gene polymorphism and serum lipid levels in the Guangxi Bai Ku Yao population

Objectives Bai Ku Yao(White-trousers Yaos)is a special branch of Yao minority in China.They are now living in both Lihu and Baxu villages,Nandan County, Guangxi,China.The population size is about 30,000.The special customs and culture of Bai Ku Yao,including their special clothing,intra-ethnic marriages and alcohol intake are still completely conserved to the present day.In previous epidemiologic studies,we found that the serum lipid levels and the prevalence of hyperlipidaemia were lower in Bai Ku Yao than in Han Chinese from the same region.This ethnic difference in serum lipid profiles is still not well known.We hypothesized that there may be significant differences in some genetic polymorphismsssociation of low density lipoprotein receptor (LDL-R) genepolymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.Methods A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were stud- ied by a stratified randomized cluster sampling.Epidemiological survey was carried out using internationally standardized methods.Information on demographics,socioeconomic status, and lifestyle factors was collected with standardized questionnaires. The height,weight,waist circumference,blood pressure, and serum total cholesterol(TC),triglyceride(TG), high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),apolipoprotein(Apo) A1, and ApoB were measured.Body massindex(BMI,kg/m2) was calculated.Genotyping of the LDL-RAvaⅡwas performed by polymerse chain reaction and restriction fragment length polymorphism combined with gel electrophoresis,and then confirmed by direct sequencing.Results(l)The height,weight,serum TC,HDL-C,LDL-C,ApoAl levels and the ratio of ApoAl to ApoB were lower in Bai Ku Yao than in Han Chinese(P【0.01 for all),whereas the percentage of subjects who consumed alcohol or smoked cigarettes was higher in Bai Ku Yao than in Han Chinese(P【0.01 for each).(2) The frequency of A+ allele in Bai Ku Yao was 34.5%,and the frequencies of A-A-,A-A+ and A+A + genotypes were 42.6%,45.9%and 11.5%;respectively. The frequency of A+ allele in Han Chinese was 19.3%(P【0.001),and the frequencies of A-A-,A-A + and A+A+ genotypes were 64.9%,31.6%and 3.5%(P【0.001);respectively. The frequencies of A-A-,A-A+ and A+A+ genotypes in Bai Ku Yao were significant difference between males and females,between normal TC and high TC subgroup, and between normal LDL-C and high LDL-C subgroup (P【0.05 for all),whereas the frequencies of A- and A+ ? alleles in Han Chinese were significant difference between males and females(P【0.05).(3) Serum LDL-C levels in Bai Ku Yao were significant difference among the A-A-, A-A+ and A+A+ genotypes(P【0.05),the A+ carriers had higher serum LDL-C levels.Serum HDL-C levels in Han Chiese were significant difference among the A-A-,A-A + and A+A+ genotypes(P【0.01),the A+ carriers had higher serum HDL-C levels.(4) After adjusting other factors,the prevalence of LDL-C abnormality was still higher in Han Chiese than in Bai Ku Yao.The prevalence of TC abnormality in Han Chinese was almost twice high as in Bai Ku Yao. The age and diet were common risk factor for TC abnormality. No effect of AvaⅡgenotype or alcohol consumption on the TC abnormality was found,but the combination of geno-type and alcohol consumption can increase the prevalence of TC abnormality[Exp(B) =(1.154)].Age was negatively cor- related with TG level.Conclusions Serum TC and LDL-C levels were lower in Bai Ku Yao than in Han Chinese.There were significant differences in the AvaⅡallele and genotype frequencies between the he A+ carriers in Bai Ku Yao had higher serum LDL-C levels,whereas the A+ carriers in Han had higher serum HDL-C levels.Interactions between alcohol consumption or cigarette smoking and the LDL-R AvaⅡgenotype were also observed.The differences in the serum lipid profiles between the two ethnic groups might partly result from different genotypic frequency of LDL-R AvaⅡpolymorphism or differentgene-enviromental interactions.Bai Ku Yao and Han population,the frequency of A + allele was higher in Bai Ku Yao than in Han.T between the two ethnic groups.Therefore,the aim of the present study was to detect the

Peroxisome proliferator-activated receptor delta+294T>C polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Objectives The association of peroxisome prolif-erator -activated receptor delta(PPARD) +294T】C polymorphism and serum lipid levels is inconsistent in several previous studies.Bai Ku Yao is an isolated association of PPARD +294T】C(rs2016520) polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.Methods A total of 609 subjects of Bai Ku Yao and 573 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples.Genotyping of the PPARD +294T】C polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.Results The levels of serum total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),apolipoprotein(Apo) AI and ApoB were lower in Bai Ku Yao than in Han(P【0.001 for all).The frequency of T and C alleles was 77.50%and 22.50%in Bai Ku Yao,and 72.43%and 27.57%in Han (P【0.01);respectively.The frequency of TT,TC and CC genotypes was 60.59%,33.83%and 5.53%in Bai Ku Yao, and 52.18%,40.50%and 7.32%in Han(P【0.05);respectively. The levels of LDL-C,ApoB and the ratio of ApoAI to ApoB in Bai Ku Yao were different among the three genotypes in females but not in males(P【0.05 for all).The subjects with TT and TC genotypes had lower serum LDL-C and ApoB levels and higher the ratio of ApoAI to ApoB than the CC genotype in females.The levels of TC and ApoB in the total Han population were different among the three genotypes (P【0.05 for all).The C allele carriers had higher serum TC and ApoB levels than the C allele noncarriers.When serum lipid levels were analyzed according to sex,the difference in serum TC levels in Han was significant in males(P【0.01) but not in females,whereas the difference in serum ApoB levels was significant in females(P【0.05)but not in males. Serum TC and ApoB levels were correlated with genotypes in Han(P【0.05 for each) but not in Bai Ku Yao.Serum lipid parameters were also correlated with sex,age,body massindex, alcohol consumption,cigarette smoking,and blood pressure in both ethnic groups.Conclusions These results suggest that the association of PPARD +294T】C polymorphism and serum lipid levels is different between the Bai Ku Yao and Han populations.The discrepancy between the two ethnic groups might partly result from different PPARD +294T】C polymorphism or PPARD gene-enviromental interactions,subgroup of the Yao minority in China.

基于ox-LDL/LOX-1信号通路探讨脂质代谢紊乱促进肺癌进展中的机制

目的基于氧化低密度脂蛋白(ox-LDL)/人凝集素样氧化低密度脂蛋白受体1(LOX-1)信号通路探讨脂质代谢紊乱促进肺癌进展的机制。方法收集81个已鉴定的具有成对相邻非癌组织(离肿瘤至少5 cm)的肺腺癌组织,使用免疫组织化学检测LOX-1表达。肺腺癌细胞系(A549、H1299细胞)中过表达LOX-1。用Transwell测定细胞侵袭能力。用不同浓度oxLDL处理细胞,并检测细胞中LOX-1表达情况。结果在包含原发性人肺癌和匹配的邻近非癌组织中,肿瘤中LOX-1染色比非癌组织样品明显增强(中值H分数99.4 vs.16.2,P<0.001)。高LOX-1表达与低生存显著相关(P<0.001)。与无淋巴结转移的患者相比,发生淋巴结转移患者的癌组织具有更高的LOX-1水平(中值H分数83.2 vs.121.1,P<0.01)。LOX-1过表达显著促进肺癌细胞的侵袭转移细胞数(P<0.01)。此外,LOX-1是ox-LDL诱导的肺癌细胞转移所必需的功能靶点。伊他替尼抑制LOX-1过表达的A549在体外的转移能力。结论LOX-1的表达随着oxLDL水平的升高而增加,并且LOX-1的表达上调促进了肺癌细胞的转移,其作用机制可能与激活Janus激酶/转录因子激活子(JAK1/STAT6)信号通路有关。

清肝降脂汤对体外诱导非酒精性脂肪肝细胞模型脂代谢和过氧化物酶体增殖物激活受体-α的调节作用研究

目的:探讨清肝降脂汤对体外诱导非酒精性脂肪肝(NAFLD)细胞模型脂代谢和过氧化物酶体增殖物激活受体(PPAR)-α的调节作用。方法:取HepG2细胞株,采用油酸构建NAFLD细胞模型。将细胞分为正常对照组(无油酸建模+无药物处理)、模型对照组(有油酸建模+无药物处理)和清肝降脂汤组(有油酸建模+有药物处理)。采用CCK-8实验检测细胞活性。采用油红O染色定性定量检测清肝降脂汤对细胞内脂质的影响,定量计算脂质含量的抑制率。同时,测定细胞内丙二醛(MDA)、超氧化物歧化酶(SOD)、甘油三酯(TG)、总胆固醇(TC)和游离脂肪酸(FFA)含量;并采用聚合酶链反应(PCR)和Western blot检测脂肪代谢标志物PPAR-α和成纤维细胞生长因子-21(FGF21)的表达水平。结果:与正常对照组相比,模型对照组的HepG2细胞活性显著增高,脂质含量显著增高,MDA、SOD、TG、TC和FFA含量显著增高,而PPAR-α和FGF21表达水平显著降低(均P<0.05);而与模型对照组相比,清肝降脂汤组的HepG2细胞活性显著降低,脂质含量显著降低,MDA、SOD、TG、TC和FFA含量显著降低,而PPAR-α和FGF21表达水平显著增高(均P<0.05)。结论:清肝降脂汤有助于降低HepG2细胞活性、脂质含量以及MDA、SOD、TG、TC和FFA含量,并促进PPAR-α和FGF21表达,进而调节脂质代谢,抑制NAFLD发展进程。

白藜芦醇通过ESR1-PI3K信号通路抑制3T3-L1细胞脂滴形成

【目的】探究白藜芦醇(RES)与雌激素受体1(ESR1)对3T3-L1细胞脂滴形成的影响及调控机制,为RES抑制脂肪沉积潜在机制的研究提供理论依据。【方法】以3T3-L1细胞为试验材料,设计并合成针对ESR1基因的小干扰RNA(siRNA),在3T3-L1细胞培养基中添加RES,以添加等量二甲基亚砜(DMSO)为对照,利用油红O染色、实时荧光定量PCR检测、Western blotting检测等分析RES与ESR1对3T3-L1细胞分化的影响。【结果】与对照组相比,RES能显著(P<0.05)减少3T3-L1细胞脂滴的生成,极显著(P<0.001)上调脂肪分解关键基因ATGL相对表达量,极显著下调(P<0.001)脂肪合成关键基因CEBPα、PPARγ及FAS相对表达量。RES能极显著(P<0.001)增加ESR1基因相对表达量,极显著(P<0.01)增加ESR1蛋白相对表达水平;同时,RES能极显著(P<0.001)下调PI3K信号通路中PI3K和AKT基因相对表达量,极显著(P<0.001)上调FOXO1基因相对表达量。干扰ESR1基因可极显著(P<0.01)增加3T3-L1细胞脂滴的生成,极显著(P<0.001)下调ATGL基因相对表达量,极显著(P<0.001)上调CEBPα、PPARγ及FAS基因相对表达量;加入RES后,干扰ESR1基因的3T3-L1细胞脂滴与未加入RES相比无显著差异(P>0.05,下同),ATGL、CEBPα、PPARγ及FAS基因相对表达量也均无显著差异。干扰ESR1基因能极显著(P<0.001)上调PI3K信号通路中PI3K和AKT基因相对表达量,极显著(P<0.001)下调FOXO1基因相对表达量;加入RES后,PI3K、AKT及FOXO1基因相对表达量与未加入RES相比均无显著差异。【结论】RES能通过ESR1-PI3K信号通路,上调脂肪分解关键基因ATGL相对表达量,下调脂肪合成关键基因CEBPα、PPARγ及FAS相对表达量,从而抑制3T3-L1细胞脂滴形成。

抑制髓样细胞触发受体-1(TREM-1)减轻慢性间歇性低氧诱发的模型小鼠动脉粥样硬化

目的探究髓样细胞触发受体-1(TREM-1)在慢性间歇性低氧(CIH)诱发的动脉粥样硬化(AS)中作用。方法将ApoE-/-小鼠随机分为空白组、模型组和实验组。模型组和实验组小鼠饲养于低氧环境,给予高脂饲料喂养;实验组小鼠高脂饲养4周后,腹腔注射TREM-1抑制剂LR12(5 mg/kg),连续干预8周。饲养12周后,检测血清总胆固醇(TC)、低密度脂蛋白(LDL)、三酰甘油(TG)、肿瘤坏死因子α(TNF-α)、白细胞介素1(IL-1β)、白细胞介素10(IL-10)水平;组织学分析主动脉TREM-1表达、斑块面积及巨噬细胞水平。结果与空白组相比,模型组小鼠主动脉TREM-1表达量显著升高(P<0.05)。相比于模型组,实验组小鼠主动脉斑块显著减少,血清血脂(TC、LDL、TG)及炎性因子(TNF-α、IL-1β、IL-10)水平显著降低,主动脉斑块及斑块浸润巨噬细胞、TREM-1表达显著减少(P<0.05),且斑块中TREM-1表达与巨噬细胞为共定位。结论TREM-1参与CIH诱发的AS发生发展,抑制TREM-1能够减轻CIH诱发的AS,其机制与抑制巨噬细胞活化有关。

生长分化因子15与胶质源性神经营养因子样受体通路对小鼠动脉粥样硬化进展的影响

目的 探讨生长分化因子15(growth differentiation factor 15,GDF-15)/胶质源性神经营养因子样受体(glial-derived neurotrophic factor receptor alpha-like, GFRAL)通路对载脂蛋白E^(-/-)小鼠动脉粥样硬化进展的影响及可能机制。方法 选择8周龄C57BL/6雄性载脂蛋白E^(-/-)小鼠8只,随机分为对照组和重组GDF-15组,每组4只。对照组:高脂饮食4周后,每周1次尾静脉注射磷酸盐缓冲液;重组GDF-15组:高脂饮食4周后,每周1次尾静脉注射重组GDF-15(0.05 mg/kg)。高脂饮食12周,监测小鼠体质量,处死小鼠。取4只同等周龄(20周龄)正常小鼠作为正常组,比较3组空腹血糖、血脂、皮质醇和醛固酮水平。主动脉冷冻切片油红O染色评估对照组和重组GDF-15组斑块大小。免疫组织化学检测对照组和重组GDF-15组脑组织GDF-15及GFRAL表达。结果 重组GDF-15组血清GDF-15水平较对照组明显升高,差异有统计学意义[(52.59±2.90)ng/ml vs(20.09±1.27)ng/ml,P<0.01]。重组GDF-15组11周和12周体质量较对照组明显减低[(28.60±0.22)g vs(29.47±0.25)g;(28.98±0.22)g vs(30.35±0.13)g,P<0.01]。重组GDF-15组三酰甘油水平较对照组明显降低[(0.22±0.02)mmol/L vs(0.38±0.09)mmol/L,P<0.05]。重组GDF-15组斑块面积明显小于对照组,差异有统计学意义[(22.22±2.58)%vs(31.61±3.51)%,P<0.01]。重组GDF-15组脑组织GDF-15和GFRAL表达较对照组明显增加(0.088±0.007 vs 0.030±0.006,0.031±0.003 vs 0.010±0.001,P<0.01)。对照组及重组GDF-15组皮质醇和醛固酮水平较正常组明显升高,差异有统计学意义(P<0.01)。重组GDF-15组醛固酮水平较对照组明显降低,差异有统计学意义[(22.01±3.67)mg/ml vs(87.29±8.63)mg/ml,P<0.01]。结论 GDF-15可能通过GFRAL调控小鼠体质量、三酰甘油及醛固酮水平影响动脉粥样硬化进展。

Liver as a new target organ in Alzheimer's disease:insight from cholesterol metabolism and its role in amyloid-beta clearance

Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.

Retinoic acid receptor responder 2 and lipid metabolic reprogramming:A new insight into brain metastasis

The brain is one of the most common metastatic sites for carcinoma,especially for breast cancer,the second leading cause of brain metastases(BrM)after lung cancer[1].During organ‐tropic metastases,cancer cells have to survive and expand in target organs through a process involving a complex interplay between invading cells and the microenvironment.