Nerve growth factor protects against palmitic acid- induced injury in retinal ganglion cells

Accumulating evidence supports an important role for nerve growth factor （NGF） in diabetic retinopathy. We hypothesized that NGF has a protective effect on rat retinal ganglion RGC-5 cells injured by palmitic acid （PA）, a metabolic factor implicated in the development of dia- betes and its complications. Our results show that PA exposure caused apoptosis of RGC-5 cells, while NGF protected against PA insult in a concentration-dependent manner. Additionally, NGF significantly attenuated the levels of reactive oxygen species （ROS） and malondialde- hyde （MDA） in RGC-5 cells. Pathway inhibitor tests showed that the protective effect of NGF was completely reversed by LY294002 （PI3K inhibitor）, Akt VIII inhibitor, and PD98059 （ERK1/2 inhibitor）. Western blot analysis revealed that NGF induced the phosphorylation of Akt/FoxO1 and ERK1/2 and reversed the PA-evoked reduction in the levels of these proteins. These results indicate that NGF protects RGC-5 cells against PA-induced injury through anti-oxidation and inhibition of apoptosis by modulation of the PI3K/Akt and ERK1/2 signaling pathways.

Eicosane, pentadecane and palmitic acid: The effects in in vitro wound healing studies

Objective: To examine the wound healing properties of eicosane, pentadecane and palmitic acid by evaluating in term of anti-microbial, anti-inflammatory, proliferation, migration and collagen synthesis. Methods: Anti-microbial activities of Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa were evaluated by carrying out disk diffusion and agar well diffusion methods. Growth rate of tested bacteria was also evaluated for 8 h in conjunction with the sample drugs. Besides, U937 cell lines were used as model study for realtime mRNA genes expression studies of TNF-毩 and IL-12 under the treatment. Proliferation, migration and collagen content synthesis were carried out on human dermal fibroblast. Results: None of the sample drugs possessed significant inhibition of bacteria tested in this study both in disk diffusion and agar well diffusion methods. In contrary, significantly low expressed mRNA gene expression levels of TNF-毩 and IL-12 were found under the treatment of respective drugs. Meanwhile in proliferation, migration and hydroxyproline content analysis, all the sample drugs showed no significant positive stimulation. Conclusions: This study therefore explains that apart from their potential in downregulating pro-inflammatory cytokines, these three compounds which were examined individually may not be good candidates in promoting wound healing.

Cannabidiol (CBD) Prevents Palmitic Acid-Induced Drop in Mitochondrial Membrane Potential

Exposure of macrophages and microglia cells to the saturated palmitic acid (PA) leads to reduction in the mitochondrial membrane potential (), shrinkage of the cells and apoptosis. Here we show that the Cannabis component Cannabidiol (CBD) rescues both macrophages and microglia cells from the detrimental effects of PA. CBD prevents the shrinkage in cell size and the reduction incaused by PA. The protective effect of CBD on the macrophage mitochondria is important for sustaining the macrophage population even under the immunosuppressed conditions caused by this drug. To a similar extent, the antagonistic effect of CBD on PA-mediated microglia cytotoxicity is important for its role in neuroprotection.

Melatonin alleviates palmitic acid-induced mitochondrial dysfunction by reducing oxidative stress and enhancing autophagy in bovine endometrial epithelial cells

Background Negative energy balance(NEB)typically occurs in dairy cows after delivery.Cows with a high yield are more likely to experience significant NEB.This type of metabolic imbalance could cause ketosis,which is often accompanied by a decline in reproductive performance.However,the molecular mechanisms underlying NEB have yet to be fully elucidated.During excessive NEB,the body fat is extensively broken down,resulting in the abnormal accumulation of non-esterified fatty acids(NEFAs),represented by palmitic acid(PA),within the uterus.Such an abnormal accumulation has the potential to damage bovine endometrial epithelial cells(BEECs),while the molecular mechanisms underlying its involvement in the PA-induced injury of BEECs remains poorly understood.Melatonin(MT)is recognized for its regulatory role in maintaining the homeostasis of mitochondrial reactive oxygen species(mitoROS).However,little is known as to whether MT could ameliorate the damage incurred by BEECs in response to PA and the mo ecu ar mechanism invo ved.Results Analysis showed that 0.2 mmol/L PA stress increased the level of cellular and mitochondrial oxidative stress,as indicated by increased reactive oxygen species(ROS)level.In addition,we observed mitochondrial dysfunction,including abnormal mitochondrial structure and respiratory function,along with a reduction in mitochondrial membrane potential and mitochondrial copy number,and the induction of apoptosis.Notably,we also observed the upregulation of autophagy proteins(PINK,Parkin,LC3B and Ubiquitin),however,the P62 protein was also increased.As we expected,100 Wmol/L of MT pre-treatment attenuated PA-induced mitochondrial ROS and restored mitochondrial respiratory function,Meanwhile,MT pretreatment reversed the upregulation of P62induced by PA and activated the AMPK-mTOR-Beclin-1 pathway,contributing to an increase of autophagy and decline apoptosis.Conclusions Our findings indicate that PA can induce mitochondrial dysfunction and enhance autophagy in BEECs.In addition,MT is proved to not only reduce mitochondrial oxidative stress but also facilitate the clearance of damaged mitochondria by upregulating autophagy pathways,thereby safeguarding the mitochondrial pool and promoting cellular viability.Our study provides a better understanding of the molecular mechanisms underlying the effect of an excess of NEB on the fertility outcomes of high yielding dairy cows.

Lipase-Catalyzed Synthesis of Sn-2 Palmitate: A Review

Human milk fat(HMF)is an important source of nutrients and energy for infants.Triacylglycerols(TAGs)account for about 98%of HMF and have a unique molecular structure.HMF is highly enriched in palmitic acid(PA)at the sn-2 position of the glycerol backbone(more than 70%)and in unsaturated fatty acids at the sn-1,3 position.The specific TAG structure in HMF plays a valuable function in infant growth.Sn-2 palmitate(mainly 1,3-dioleoyl-2-palmitoyl-glycerol)is one of the structured TAGs that is commonly supplemented into infant formula in order to enable it to present a similar structure to HMF.In this review,the development of the lipase-catalyzed synthesis of sn-2 palmitate over the last 25 years are summarized,with a focus on reaction schemes in a laboratory setting.Particular attention is also paid to the commercialized sn-1,3 regioselective lipases that are used in structured TAGs synthesis,to general methods of TAG analysis,and to successfully developed sn-2 palmitate products on the market.Prospects for the lipase-catalyzed synthesis of sn-2 palmitate are discussed.

Lipase-catalyzed regioselective synthesis of palmitolyglucose ester in ionic liquids

Candida antarctica lipase B (CAL-B) was used as a catalyst in the synthesis of palmitolyglucose ester in the ionic liquids, 1-butyl-3-methylimidazolium triflu- oromethanesulfonate ([Bmim][TfO]), with glucose as a substrates and palmitic acid vinyl ester as the acyl donor. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was studied. The reaction conditions in [Bmim][TfO] re- sulting in the highest yield of the sugar ester were a temperature of 50?C, enzyme concentration of 50 mg/ mL, and a molar ratio of glucose/vinyl palmitate of 1:3. The major reaction product was purified and char- acterized by FT-IR, HPLC, MS and NMR, as being 6-O-palmitolyglucose ester. The advantages of ionic liquid vs. organic solvent were noted.

Reaction kinetics of isopropyl palmitate synthesis

In this study, the kinetics of isopropyl palmitate synthesis including the reaction mechanism was studied based on the two-step noncatalytic method. The liquid-phase diffusion effect on the reaction process was eliminated by adjusting the stirring rate. The results showed that the two-step reaction followed a tetrahedral mechanism and conformed to second-order reaction kinetics. Nucleophilic attack on the carbonyl carbon afforded an intermediate, containing a tetrahedral carbon center. The intermediate ultimately decomposed by elimination of the leaving group, affording isopropyl palmitate. The experimental data were analyzed at different temperatures by the integral method. The kinetic equations of the each step were deduced, and the activation energy and frequency factor were obtained. Experiments were performed to verify the feasibility of kinetic equations, and the result showed that the kinetic equations were reliable. This study could be very signi ficant to both industrial application and determining the continuous production of isopropyl palmitate.

血清LncRNA UCA1、NPASDP4水平与急性脑梗死患者神经功能缺损的关系及对预后的预测价值

目的探讨血清长链非编码核糖核酸尿路上皮癌胚抗原1(LncRNA UCA1)、神经元PAS结构域蛋白4(NPASDP4)水平与急性脑梗死(ACI)患者神经功能缺损的关系及对预后的预测价值。方法选取2021年1月—2023年6月南京大学医学院附属鼓楼医院急诊科收治的ACI患者163例(ACI组),根据美国国立卫生研究院卒中量表(NIHSS)评分分为轻度(n=32)、中度(n=73)、重度缺损亚组(n=58),另选取同期健康体检者65例作为健康对照组。根据ACI患者90 d预后分为不良预后亚组52例、良好预后亚组111例。采用实时荧光定量聚合酶链式反应与酶联免疫吸附法,检测血清LncRNA UCA1与NPASDP4水平。Spearman相关性分析血清LncRNA UCA1、NPASDP4水平与ACI患者NIHSS评分的相关性。多因素Logistic回归分析ACI患者不良预后的因素,受试者工作特征(ROC)曲线分析血清LncRNA UCA1、NPASDP4预测ACI患者不良预后的价值。结果与健康对照组比较,ACI组血清LncRNA UCA1、NPASDP4水平升高(t/P=20.114/<0.001、15.711/<0.001)。血清LncRNA UCA1、NPASDP4水平重度缺损亚组>中度缺损亚组>轻度缺损亚组(F/P=187.914/<0.001、195.031/<0.001)。ACI患者血清LncRNA UCA1、NPASDP4水平与NIHSS评分呈正相关(r/P=0.759/<0.001、0.773/<0.001)。随访90 d,与良好预后亚组比较,不良预后亚组血清LncRNA UCA1、NPASDP4水平升高(t/P=6.963/<0.001、6.515/<0.001)。年龄大、NIHSS评分增加、LncRNA UCA1和NPASDP4升高为ACI患者不良预后的独立危险因素[OR(95%CI)=1.107(1.043~1.176)、1.098(1.049~1.150)、3.479(1.941~6.235)、1.959(1.398~2.745)]。血清LncRNA UCA1、NPASDP4及二者联合预测不良预后的AUC分别为0.777、0.789、0.870,二者联合大于血清LncRNA UCA1、NPASDP4单独预测的AUC(Z/P=3.312/0.001、2.721/0.007)。结论血清LncRNA UCA1表达、NPASDP4水平升高与ACI患者神经功能缺损加重和不良预后密切相关,血清LncRNA UCA1联合NPASDP4水平预测ACI患者不良预后的效能较高。

Dihydroartemisinin ameliorates palmitate-induced apoptosis in cardiomyocytes via regulation on miR-133b/Sirt1 axis

Excessive fat ectopically deposited in the non-adipose tissues is considered as one of the leading causes of myopathy.The aim of this study was to investigate the role of Dihydroartemisinin(DHA)in palmitate(PAL)-incubated H9c2 cells(lipotoxicity-induced cell injury model).Cell viability of PAL-treated cells was determined by MTT assay,and apoptotic regulators were examined by qRT-PCR and western blot analysis,in the absence or in the presence of DHA,respectively.Expression levels of miR-133b and Sirt1 were also evaluated by qRT-PCR and western blotting examination.PAL decreased the viability of H9c2 cells and enhanced the expression of apoptotic genes.DHA reversed the effect of PAL on cell viability and lowed the level of Caspase3 and Bax.It also lowered the expression of miR-133b,while enhanced the expression of Bcl-2.Sirt1 was revealed as target of miR-133b through transcriptional regulation and the process was affected by DHA.DHA partially protected against the PAL-induced lipotoxicity by influencing the expression of miR-133b that hindered the activity of Sirt1.DHA may be used as a potential treatment in clinical management for lipotoxicity induced heart complications.

Palmitic acid reduces the methylation of the FOXO1 promoter to suppress the development of diffuse large B-cell lymphoma via modulating the miR-429/DNMT3A axis

Diffuse large B-cell lymphoma(DLBCL)is characterized by significant treatment resistance.Palmitic acid(PA)has shown promising antitumor properties.This study aims to elucidate the molecular mechanisms by which PA influences DLBCL progression.We quantified the expression levels of microRNAs(miRNAs),Forkhead box protein O1(FOXO1),and DNA methyltransferase 3A(DNMT3A)in both untreated and PA-treated DLBCL tumors and cell lines.Assessments were made of cell viability,apoptosis,and autophagy-related protein expression following PA administration.Interaction analyses among miR-429,DNMT3A,and FOXO1 were conducted using luciferase reporter assays and methylation-specific(MSP)Polymerase chain reaction(PCR).After transfecting the miR-429 inhibitor,negative control(NC)inhibitor,shRNA against DNMT3A(sh-DNMT3A),shRNA negative control(sh-NC),over-expression vector for DNMT3A(oe-DNMT3A),or overexpression negative control(oe-NC),we evaluated the effects of miR-429 and DNMT3A on cell viability,mortality,and autophagy-related protein expression in PA-treated DLBCL cell lines.The efficacy of PA was also tested in vivo using DLBCL tumor-bearing mouse models.MiR-429 and FOXO1 expression levels were downregulated,whereas DNMT3A was upregulated in DLBCL compared to the control group.PA treatment was associated with enhanced autophagy,mediated by the upregulation of miR-429 and downregulation of DNMT3A.The luciferase reporter assay and MSP confirmed that miR-429 directly inhibits DNMT3A,thereby reducing FOXO1 methylation.Subsequent experiments demonstrated that PA promotes autophagy and inhibits DLBCL progression by upregulating miR-429 and modulating the DNMT3A/FOXO1 axis.In vivo PA signific-antly reduced the growth of xenografted tumors through its regulatory impact on the miR-429/DNMT3A/FOXO1 axis.Palmitic acid may modulate autophagy and inhibit DLBCL progression by targeting the miR-429/DNMT3A/FOXO1 signaling pathway,suggesting a novel therapeutic target for DLBCL management.

曲美他嗪对棕榈酸诱导的H9C2心肌细胞脂毒性凋亡的影响

目的:建立棕榈酸(PA)诱导的H9C2细胞凋亡模型,验证曲美他嗪(TMZ)是否对H9C2细胞脂毒性凋亡产生保护作用及具体机制。方法:在体外培养的H9C2心肌细胞,当细胞密度为90%时分别给予不同时间(0、6、12、24 h)、不同浓度(0、50、100、150、200、300、350μmol/L)的PA刺激(n=3),建立脂毒性损伤模型,用CCK8检测细胞活性确定最佳刺激条件,蛋白印迹法证实细胞凋亡。实验共分6组,分别为对照组(CON)、PA(200μmol/L)组、CON+TMZ3(10μmol/L)组、PA(200μmol/L)+TMZ1(0.1μmol/L)组、PA(200μmol/L)+TMZ2(1μmol/L)组、PA(200μmol/L)+TMZ3(10μmol/L)组(n=3),用CCK8检测细胞活性、蛋白印迹测定凋亡相关蛋白表达量。后续为观察细胞内脂质含量变化,实验分为4组,分别为对照组(CON)、PA(200μmol/L)组、TMZ3(10μmol/L)组、PA(200μmol/L)+TMZ3组(n=3),通过油红O染色镜下观察。结果:与CON组相比,200μmol/L PA组及12 h组细胞活力明显下降(t=15.8、20.82,均P<0.05),使用CCK8检测并最终确定PA 200μmol/L、刺激12 h的条件下,H9C2细胞脂毒性损伤较大、存活细胞最多。与CON组相比,200μmol/L PA组Bax蛋白表达明显升高(t=3.201,P<0.05),150μmol/L PA组Bcl-2蛋白表达明显降低(t=2.479,P<0.05),蛋白检测证实细胞凋亡。与PA刺激组相比,PA+TMZ1组、PA+TMZ2组、PA+TMZ3组的细胞活力升高(F=420.1,均P<0.05)、PA+TMZ2组、PA+TMZ3组凋亡相关蛋白Bcl-2表达升高(t=6.028、8.952,均P<0.05)、Bax表达下降(t=3.392、4.275,均P<0.05),随着TMZ浓度的增加,Bax表达降低、Bcl-2表达增加(F=3.763、7.548,均P<0.05)。与CON组相比,PA组H9C2细胞内脂滴含量明显增多。与PA组相比,PA+TMZ3组H9C2细胞内脂滴含量明显减少。结论:棕榈酸刺激可诱导H9C2心肌细胞脂毒性凋亡,曲美他嗪可抑制棕榈酸诱导的H9C2细胞脂毒性凋亡。

通心络下调caspase-3蛋白表达及活性抑制软脂酸诱导的人外周血内皮祖细胞凋亡

目的:探讨通心络(tongxinluo,TXL)对软脂酸(palmitic acid,PA)诱导的人外周血内皮祖细胞(endothelialprogenitor cell,EPCs)凋亡及caspase-3蛋白表达和活性的影响。方法:密度梯度离心法获取人外周血单个核细胞,培养7d后,贴壁细胞分成7组:对照组以M199培养液培养48h;PA各浓度组(共3组)分别用含200,400,800μmol/L PA的M199培养液孵育48h;通心络干预组(共3组)分别先用含100,200,400μmol/L TXL的M199培养液干预2h后,再加入400μmol/L PA孵育48h。采用流式细胞仪检测细胞凋亡率;提取细胞蛋白,采用Westernblot技术检测caspase-3蛋白表达水平;采用分光光度法检测caspase-3蛋白活性水平。结果:PA呈浓度依赖性诱导EPCs凋亡;加入TXL干预,EPCs细胞凋亡率明显降低;Western blot和分光光度法检测显示,PA组EPCs的caspase-3蛋白表达及活性明显高于对照组,200和400μmol/L TXL干预组明显低于PA组(P<0.05)。结论:PA呈浓度依赖性诱导EPCs凋亡,TXL能部分抑制PA的上述作用,其机制与下调caspase-3蛋白表达及活性有关。

软脂酸在体外激活Caspase9和Caspase3引起L02细胞凋亡

以人肝细胞系L02为试验材料,采用Western blot和流式细胞术检测软脂酸对L02细胞凋亡及Caspase3、Caspase9信号的影响,为解决动物摄入高能量日粮时肝损伤状况提供理论依据。试验结果显示,软脂酸可以通过激活Caspase3和Caspase9引起L02细胞凋亡,发生凋亡的L02细胞多处于凋亡早期,L02细胞凋亡率与软脂酸的剂量呈正相关。当软脂酸浓度超过30mg/mL,处理24h后可显著升高L02细胞凋亡率(P<0.05)。上述结果表明,软脂酸在体外激活Caspase9和Caspase3信号从而诱导L02细胞进入早期凋亡阶段。

填充增强PA6/PP合金的性能

以衣康酸接枝PP(I-PP)作PA6/PP增容剂,将制得的PA6/I-PP/PP合金与滑石、云母、玻纤单独或组合复合,研究了复合材料的力学性能与填充量、组合填充配比的关系。

PAS、AB染色法在软骨蛋白黏多糖检测中的运用

[目的 ] 探讨过碘酸雪夫氏反应PAS染色 (PeriodicAcidSchiff)及阿利辛兰AB染色 (AlcianBlue)组织化学分析法在检测软骨组织蛋白黏多糖含量中的运用价值。 [方法 ] 以原发性退行性骨关节炎动物模型的软骨为检测标本 ,分别采用PAS和AB染色法 ,观察软骨组织中蛋白黏多糖的含量。 [结果 ] PAS染色法中软骨组织基质中的中性黏多糖呈紫红色 ,软骨细胞内为无色。AB法中软骨细胞周围的酸性黏多糖呈深蓝色 ,基质呈淡蓝色。此外 ,随着动物模型关节炎程度的不断加剧 ,即软骨组织中蛋白黏多糖丢失的不断增加 ,标本中的紫红色和深蓝色也相应减退 ,直至消失。 [结论 ] PAS染色法和AB染色法能清楚地区分软骨基质中的中性黏多糖和细胞囊内的酸性黏多糖 ,并能对它们的改变进行量化分析。可作为软骨组织中黏多糖检测的有效方法。

rt-PA静脉溶栓对脑梗死早期患者血清神经特异性烯醇酶、C反应蛋白及脂肪酸结合蛋白水平影响研究

目的探讨rt-PA静脉溶栓对脑梗死早期患者血清神经特异性烯醇酶(NSE)、C反应蛋白(CRP)及脂肪酸结合蛋白水平(FABP)的影响。方法收集大连市中心医院收治的急性脑海梗死患者54例,随机分为对照组和实验组,每组27例,2组均给予降低颅内压、改善循环、营养脑细胞常规治疗,对照组在此基础上给予低分子肝素钙注射液5000 U皮下注射,1次/12 h,连续7 d;实验组在对照组基础上,给予注射用阿替普酶(rt-PA)溶栓治疗,连续7 d,治疗结束后,对所有患者的NSE、CRP及FABP水平进行检测。结果与对照组治疗后比较,实验组患者血清CRP、NSE和FABP水平显著降低(P<0.05)。结论 rt-PA静脉溶栓能够显著降低脑梗死早期患者血清NSE、CRP及FABP水平,改善患者预后,对临床有指导意义。

PARP-1抑制剂在游离脂肪酸诱导胰岛细胞凋亡中的作用

目的:探讨PARP-1抑制剂3-氨基苯酰胺(3-Aminobenzamide,3-AB)在游离脂肪酸棕榈酸诱发的胰岛细胞凋亡和坏死中的作用。方法:常规培养RIN-m5F细胞株,采用四甲基偶氮唑盐(MTT)比色法观察棕榈酸和PARP-1抑制剂3-AB作用后细胞的增殖情况,并用流式细胞术及TUNEL法分析细胞凋亡和坏死。结果:棕榈酸明显抑制RIN-m5F细胞的增殖(P<0.01);低浓度3-AB与棕榈酸共同孵育24h后细胞的凋亡率和坏死率显著低于棕榈酸单独培养(P<0.01);高浓度3-AB与棕榈酸共同孵育后较棕榈酸单独培养时细胞凋亡率显著性增强(P<0.01)。结论:低浓度3-AB能有效抑制棕榈酸所诱导的胰岛细胞株RIN-m5F细胞坏死,缓解细胞凋亡;而高浓度3-AB则促进细胞凋亡。进一步说明了3-AB在棕榈酸所诱导的胰岛细胞凋亡过程中具有双重作用,此可为2型糖尿病的治疗提供一个新的靶点。

超细PA/PU合成革用酸性染料的染色性能研究

本文通过使用各种酸性染料(一般酸性染料、弱酸性染料、酸性络合染料、中性染料)对超细PA/PU合成革进行染色试验,研究了它们各自的染色性能,探讨了固色剂对染料的固色性能,分析并总结了各染料结构及颜色与染色性能之间的关系。

糖蛋白PAGE分离后的糖基显色法

鸡卵清蛋白通过SDS-PAGE分离后,用过碘酸-希夫(PAS)显色法可以使卵清蛋白显红色,而用糖苷酶去除卵清蛋白的糖基可以去除相应的红色。考马斯亮兰染色结果显示,去糖基后的卵清蛋白分子量略有减小。可见,PAS可方便地使糖蛋白呈现红色。

OPA柱前衍生反相高效液相色谱法测定脑组织中氨基酸类神经递质

目的:建立一种脑组织中氨基酸类神经递质测定的方法。方法:利用邻苯二甲醛(OPA)柱前衍生反相高效液相色谱法结合荧光检测器测定标准品或脑组织中5种氨基酸(谷氨酸、门冬氨酸、甘氨酸、谷氨酰胺、γ-氨基丁酸)的含量。结果:5种氨基酸于15min内得到了很好的分离,在1～10μmol/L和10～100μmool/L浓度范围内与峰高有良好的线性关系。结论:本方法具有快速、准确、灵敏度高、稳定性好等优点,适用于脑组织中微量氨基酸类神经递质的测定。