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.

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.

Effects of Berberine and Cinnamic Acid on Palmitic Acid-Induced Intracellular Triglyceride Accumulation in NIT-1 Pancreatic β Cells

Objective： To investigate the effects of berberine （BBR） and cinnamic acid （CA）, the main active components in Jiaotai Pill （交泰丸, JTP）, on palmitic acid （PA）-induced intracellular tdglyceride （TG） accumulation in NIT-1 pancreatic 13 cells. Methods： Cells were incubated in culture medium containing PA （0.25 mmol/L） for 24 h. Then treatments with BBR （10 μmol/L）, CA （100 μmol/L） and the combination of BBR and CA （BBR＋CA） were performed respectively. Intracellular lipid accumulation was assessed by Oil Red O staining and TG content was measured by colorimetric assay. The expression of adenosine monophosphate-activated protein kinase （AMPK） protein and its downstream lipogenic and fatty acid oxidation genes, including fatty acid synthase （FAS）, acetyl-coA carboxylase （ACC）, phosphorylation acetyl-coA carboxylase （pACC）, carnitine acyl transferase 1 （CPT-1） and sterol regulating element binding protein lc （SREBP-lc） were determined by Western blot or real time polymerase chain reaction. Results： PA induced an obvious lipid accumulation and a significant increase in intracellular TG content in NIT-1 cells. PA also induced a remarkable decrease in AMPK protein expression and its downstream targets such as pACC and CPT-I. Meanwhile, AMPK downstream lipogenic genes including SREBP-lc mRNA, FAS and ACC protein expressions were increased. Treatments with BBR and BBR＋CA, superior to CA, significantly reversed the above genes changes in NIT-1 pancreatic 13 cells. However, the synergistic effect of BBR and CA on intracellular TG content was not observed in the present study. Conclusion： It can be concluded that in vitro, BBR and BBR＋CA could inhibit PA-induced lipid accumulation by decreasing lipoqenesis and increasin.cl lipid oxidation in NIT-1 pancreatic B cells.

Ni nanoparticles encapsulated within H-type ZSM-5 crystals for upgrading palmitic acid to diesel-like fuels

Meso-Ni@HZSM-5 bi-functional catalysts were successfully post-encapsulated with about 3-7 nm Ni nanoparticles within HZSM-5 crystals,which exhibited significantly efficient conversion activity(67.4 g[palmitic acid]g[Ni]^(−1)h^(−1))of palmitic acid and 100%selectivity of hydrocarbons with the outstanding stability during recycling application,compared to the impregnated Ni/HZSM-5 catalyst(14.0 g[palmitic acid]g[Ni]^(−1)h^(−1)).

Similarity of Binding Potentials Between Plant DUF538 and Animal Lipocalin: Cholesterol Binding Ability of DUF538

Objective DUF538(domain of unknown function 538) domain containing proteins are known as putative hypothetical proteins in plants. Until yet, there is no much information regarding their structure and function. Methods In the present research work, the homologous structures and binding potentials were identified between plant/mammalian lipocalins and plant DUF538 protein by using bioinformatics and experimental tools including molecular dynamics simulation, molecular docking and recombinant technology-based techniques. Results Molecular docking analysis of their interactions with lipidic ligands including cholesterol and palmitic acid revealed the similar and comparable binding potentials between DUF538 and lipocalin proteins. Both the test proteins were found to have more affinity to cholesterol molecule in compare to palmitic acid. By using recombinant technology-based experiments, the heterologously expressed and purified fused product of DUF538 protein exhibited about 61% cholesterol binding ability. Conclusion As a conclusion, plants DUF538 protein family was predicted to be the structural and may be the functional homologues of plants/animals lipocalin superfamily.

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.

Structural and electronic effects boosting Ni-doped Mo_(2)C catalyst toward high-efficiency C-O/C-C bonds cleavage

The selective cleavage of C-O and C-C is facing a challenge in the field of catalysis.In the present work,we studied the influence of doped Ni on the structure and electronic properties,as well as the selective C-O/C-C bond cleavages in the hydrodeoxygenation of palmitic acid over Ni-Mo_(2)C catalyst.The catalytic activity on Ni doped Mo_(2)C with TOF of 6.9×10^(3)h^(-1)is much superior to intrinsic Mo_(2)C catalyst,which is also higher than most noble metal catalysts.Structurally,the doped Ni raises the active particle dispersion and the coordination numbers of Mo species(Mo-C and Mo-O),improves the graphitization degree to promote the electron transfer,and increases the amount of Lewis and Br?nsted acid,which are responsible for the excellent hydrodeoxygenation performance.The Ni promotes simultaneously C-O and C-C bonds cleavage to produce pentadecane and hexadecane owing to the increase of electron-rich Mo sites after Ni doping.These findings contribute to the understanding of the nature of Ni-doped Mo_(2)C on the roles as catalytic active sites for C-O and C-C bonds cleavage.

Effect of a Diet Rich in Interesterified, Non-Interesterified and Trans Fats on Biochemical Parameters and Oxidative Status of Balb-c Mice

The aim of this study was to investigate the effects of different modified fats on the body weight, biochemical profile, and biomarkers of hepatic oxidative status in Balb-c mice. The animals were divided into four groups and fed for 75 days with a normolipidic (Control Group, CG) or hiperlipidic diets (40% kcal) containing a commercial interesterified fat (IFG) rich in palmitic acid (39%);a blend of non-interesterified fat (NIFG), with 2-fold less saturated fatty acids at the sn-2 position of triacylglycerols;or a partially hydrogenated vegetable oil (PHFG), source of trans fatty acid (20%) and of linolenic acid (6%). The mice of the IFG and NIFG presented similar results in all evaluated parameters. The serum biochemical profile and hepatic oxidative stress markers in mice of the PHFG were similar to CG, except for total cholesterol (TC) which was significantly higher (p < 0.05) for the mice of the PHFG. The mice feed with interesterified fat (IFG) showed serum TC (p < 0.01), non-HDL-C (p < 0.05), glucose (p < 0.05) and hepatic reduced glutathione values (2.7 fold, p < 0.05) and glutathione reductase activity (2.4 fold, p < 0.001) significantly higher when compared to the mice fed with partially hydrogenated vegetable oil (PHFG). The hydrogenated fat source of trans fatty acid (20%) had less important metabolic effects than fats containing amounts of palmitic acid (interesterified or non-interesterified). Our results suggest that the replacement of hydrogenated fats by interesterified fats may not be such a simple solution to reduce or eliminate trans fatty acids in foods.

Volatile Constituents of Leaves of Trifolium alexandrinum

This study presents the volatile constituents from leaves of Trifolium alexandrinum from Pakistan.The dried leaves were subjected to hydrodistillation for extraction and extracted volatile oil was subsequently characterized by gas chromatography-mass spectrometry technique.A total of 22 compounds were identified where the most dominant constituents were:phytol(46.00%),palmitic acid(9.26%),phytol acetate(6.44%),and linolenic acid(3.47%).Most of these are well-known constituents to exhibit antibacterial,antioxidant,antitumor,and anti-inflammatory activities.

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.

Ferroptosis inhibitors reduce celastrol toxicity and preserve its insulin sensitizing effects in insulin resistant HepG2 cells

Objective:Research has shown that celastrol can effectively treat a variety of diseases,yet when passing a certain dosage threshold,celastrol becomes toxic,causing complications such as liver and kidney damage and erythrocytopenia,among others.With this dichotomy in mind,it is extremely important to find ways to preserve celastrol’s efficacy while reducing or preventing its toxicity.Methods:In this study,insulin-resistant Hep G2(IR-Hep G2)cells were prepared using palmitic acid and used for in vitro experiments.IR-Hep G2 cells were treated with celastrol alone or in combination with Nacetylcysteine(NAC)or ferrostatin-1(Fer-1)for 12,24 or 48 h,at a range of doses.Cell counting kit-8assay,Western blotting,quantitative reverse transcription-polymerase chain reaction,glucose consumption assessment,and flow cytometry were performed to measure celastrol’s cytotoxicity and whether the cell death was linked to ferroptosis.Results:Celastrol treatment increased lipid oxidation and decreased expression of anti-ferroptosis proteins in IR-Hep G2 cells.Celastrol downregulated glutathione peroxidase 4(GPX4)m RNA.Molecular docking models predicted that solute carrier family 7 member 11(SLC7A11)and GPX4 were covalently bound by celastrol.Importantly,we found for the first time that the application of ferroptosis inhibitors(especially NAC)was able to reduce celastrol’s toxicity while preserving its ability to improve insulin sensitivity in IR-Hep G2 cells.Conclusion:One potential mechanism of celastrol’s cytotoxicity is the induction of ferroptosis,which can be alleviated by treatment with ferroptosis inhibitors.These findings provide a new strategy to block celastrol’s toxicity while preserving its therapeutic effects.

Ethanol promotes saturated fatty acid-induced hepatoxicity through endoplasmic reticulum(ER) stress response

Serum palmitic acid(PA), a type of saturated fatty acid, causes lipid accumulation and induces toxicity in hepatocytes.Ethanol(Et OH) is metabolized by the liver and induces hepatic injury and inflammation. Herein, we analyzed the effects of Et OH on PA-induced lipotoxicity in the liver. Our results indicated that Et OH aggravated PA-induced apoptosis and lipid accumulation in primary rat hepatocytes in dose-dependent manner. Et OH intensified PA-caused endoplasmic reticulum(ER) stress response in vitro and in vivo, and the expressions of CHOP, ATF4, and XBP-1 in nucleus were significantly increased. Et OH also increased PA-caused cleaved caspase-3 in cytoplasm. In wild type and CHOP–/– mice treated with Et OH and high fat diet(HFD), Et OH worsened the HFD-induced liver injury and dyslipidemia, while CHOP knockout blocked toxic effects of Et OH and PA. Our study suggested that targeting UPR-signaling pathways is a promising, novel approach to reducing Et OH and saturated fatty acid-induced metabolic complications.

Muscadine or amla extracts standardized to ellagic acid content ameliorate glucolipotoxicity associatedβ-cell dysfunction via inhibition of IL-1βand improved insulin secretion

Glucolipotocixity induces IL-1βsecretion which impairs pancreaticβ-cell insulin secretion.Ellagic acid and urolithin A have strong anti-inflammatory effect on cells.Muscadine and amla are very good sources of ellagic acid.The present study examined the effect of ellagic acid,ellagic acid-rich muscadine or amla extract,or urolothin A on inflammation inβcells under glucolipotoxic conditions.Rat NIT-1βcells were incubated in glucolipotoxic conditions(33.3 mM glucose,250μM palmitic acid or 33.3 mM glucose+250μM palmitic acid with or without ellagic acid,ellagic acid-rich muscadine or amla extracts standardized to its ellagic acid content,or urolithin A).Inflammatory status was evidenced by ELISA analysis of insulin and IL-1βsecretion.Ellagic acid-rich muscadine or amla extracts dose-dependently stimulated insulin secretion and down-regulated IL-1βbetter than pure ellagic acid,or urolithin A.Urolithin A did not statistically stimulate insulin secretion and did not inhibit IL-1β.

Propionate promotes gluconeogenesis by regulating mechanistic target of rapamycin(mTOR)pathway in calf hepatocytes

Enhancing hepatic gluconeogenesis is one of the main modes of meeting the glucose requirement of dairy cows.This study attempted to determine whether the gluconeogenesis precursor propionate had an effect on the expression of the main genes involved in gluconeogenesis in calf hepatocytes and elucidate the associated mechanisms.Calf hepatocytes were obtained from 5 healthy calves(1 d old;30to 40 kg)and exposed to 0-,1-,2.5-,or 5-mM sodium propionate(NaP),which is known to promote the expression of genes involved in the gluconeogenesis pathway,including fructose 1,6-bisphosphatase,phosphoenolpyruvate carboxykinase,and glucose-6-phosphatase.With regard to the underlying mechanism,propionate promoted the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha,hepatocyte nuclear factor 4,and forkhead box O1(transcription factors that regulate the expression of hepatic gluconeogenic genes)by promoting mammalian target of rapamycin complex 1(mTORC1),but inhibiting mTORC2 activity(P<0.01).We also established a model of palmitic acid(PA)-induced hepatic injury in calf hepatocytes and found that PA could inhibit the gluconeogenic capacity of calf hepatocytes by suppressing the expression of gluconeogenic genes,inhibiting m TORC1,and promoting the activity of m TORC2(P<0.01).In contrast,NaP provided protection to calf hepatocytes by counteracting the inhibitory effect of PA on the gluconeogenic capacity of calf hepatocytes(P<0.05).Collectively,these findings indicate that NaP enhances the gluconeogenic capacity of calf hepatocytes by regulating the mTOR pathway activity.Thus,in addition to improving the glucose production potential,propionate may have therapeutic potential for the treatment of hepatic injury in dairy cows.

Double-lipase Catalyzed Synthesis of Kojic Dipalmitate in Organic Solvents

Kojic dipalmitate（KDP） was synthesized by the way of esterification ofpalmitic and kojic acids in organic solvent, with double-lipase as the biocatalyst. Four commercially available lipases（Amano PS, Novozym 435, Lipozyme TL IM and Lipozyme RM IM） were used to group six double-lipase combinations. These combinations were studied and Amano PS-Novozym 435 was found to have the best efficiency and was selected for optimizing the reaction conditions. The optimal reaction conditions were as follows. The mass ratio ofAmano PS to Novozyme 435 was 1：1.5, with stirring speed of 500 r/min, substrates molar ratio of 1：2, 50 ℃, 5%（mass fraction） catalyst dosage of kojic acid quantity and using acetone as co-solvent. Under these conditions, the diesterification of C5 and C7 hydroxyl groups of kojic acid molecule could be well catalyzed by double-lipase and realize a high KDP yield of 85%.