Arachidonic Research Articles

Structured Triacylglycerol with Optimal Arachidonic Acid and Docosahexaenoic Acid Content for Infant Formula Development: A Bio-Accessibility Study.

Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (ARA) and docosahexaenoic acid (DHA), are extremely important fatty acids for brain development in the fetus and early childhood. Premature infants face challenges obtaining these two fatty acids from their mothers. It has been reported that supplementation with triacylglycerols (TAGs) with an ARA:DHA (w/w) ratio of 2:1 may be optimal for preterm infants, as presented in commercial formulas such as Formulaid™. This study explored methods to produce TAGs with a 2:1 ratio (ARA:DHA), particularly at the more bioavailable sn-2 position of the glycerol backbone. Blending and enzymatic acidolysis of microalgae oil (rich in DHA) and ARA-rich oil yielded products with the desired ARA:DHA ratio, enhancing sn-2 composition compared to Formulaid™ (1.6 for blending and 2.3 for acidolysis versus 0.9 in Formulaid™). Optimal acidolysis conditions were 45 °C, a 1:3 substrate molar ratio, 10% Candida antarctica lipase, and 4 h. The process was reproducible, and scalable, and the lipase could be reused. In vitro digestion showed that 75.5% of the final product mixture was bio-accessible, comprising 19.1% monoacylglycerols, ~50% free fatty acids, 14.6% TAGs, and 10.1% diacylglycerols, indicating better bio-accessibility than precursor oils.

Nanoscale Structural Characterization of Amyloid β 1-42 Oligomers and Fibrils Grown in the Presence of Fatty Acids.

Mono- and polyunsaturated fatty acids (FAs) are broadly used as food supplements. However, their effect on the aggregation of amyloidogenic proteins remains unclear. In this study, we investigated the effect of a large number of mono- and polyunsaturated, as well as fully saturated FAs on the aggregation of amyloid β1-42 (Aβ1-42) peptide. A progressive aggregation of this peptide is the expected molecular cause of Alzheimer's disease (AD), one of the most common neurodegenerative pathologies in the world. We found that arachidonic and stearic acids delayed the aggregation of Aβ1-42. Using Nano-Infrared spectroscopy, we found that FAs caused very little if any changes in the secondary structure of Aβ1-42 oligomers and fibrils formed at different stages of protein aggregation. However, the analyzed mono- and polyunsaturated, as well as fully saturated FAs uniquely altered the toxicity of Aβ1-42 fibrils. We found a direct relationship between the degree of FAs unsaturation and toxicity of Aβ1-42 fibrils formed in their presence. Specifically, with an increase in the degree of unsaturation, the toxicity Aβ1-42/FA fibrils increased. These results indicate that fully saturated or monounsaturated FAs could be used to decrease the toxicity of amyloid aggregates and, consequently, decelerate the development of AD.

Abstract P220: Abdominal Aortic Perivascular Adipose Tissue Lipolysis Is Activated In Hypertensive Dahl SS Rats Fed a High-Fat Diet

Perivascular adipose tissues (PVAT) possess anti-contractile functions that are lost during hypertension (HTN). PVAT stores fatty acids (FA) and releases them through lipolysis upon adrenergic or inflammatory stimuli. Visceral AT lipolysis in humans with high abdominal adiposity and hypertension elevates FA release, promoting HTN via lipotoxicity and increased oxylipin synthesis. We hypothesize that lipolytic activity in abdominal aortic PVAT (aaPVAT) is increased during HTN. Plasma and aaPVAT were harvested from Dahl SS rats fed a high-fat (HF) or a control (CON) diet for 8 (♂=20, ♀=20), 16 (♂=10, ♀=10) and 24 (♂=14, ♀=14) wks. Mean arterial pressure (MAP±SEM; mmHg) was measured with sphyngomanometry. Free FA (FFA), β-hydroxybutyrate (BHB), glucose, and triglycerides were quantified with the CataChemWell-T analyzer, and individual FA using HPLC–MS/MS (reported as ng/dL). Adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and phosphorylated pHSL(Ser563) were quantified in the Abby Western Blot. HF increased MAP compared to CON by 8 (131.5 vs 119.51±2.52), 16 (139.34 vs 118.26±5.7), and 24 wks (168.56 vs 121.94±3.93). HF at 24 wks had higher MAP compared to 8 and 16 wks. HF increased FFA and BHB at all time points and glucose at 24 wks. Plasma triglycerides were increased in HF vs. CON, and ♂ had higher levels than ♀ at all time points. ATGL, basal lipolysis rate-limiting enzyme, increased in aaPVAT from HF ♂ by 2.2, 2.53, and 1.82-fold at 8, 16, and 24 wks, respectively, compared to CON. In HF ♀, ATGL increased (1.95-fold change) at 16 wks vs. 8 wks. HSL content increased in HF vs. CON at 16 wks (2.1-fold change) but not at 24 wks. In contrast, pHSL abundance and the pHSL:HSL ratio were not affected by diet at 16 wks; however, both were reduced by 35.2% at 24 wks in HF ♂ and ♀. Lipolytic activity in HF coincided with higher plasma arachidonic (AA) and linoleic acid (LA) at 8 (AA HF=19.93, CON= 16.13±1.3; LA HF=29.22, CON=21.74±2.7) and 16 wks (AA HF=14.83, CON=11.61±1.34; LA HF=22.84, CON=11.66±2.9). Sex had no effect on AA or LA concentrations. Our results provide evidence that hypertensive Dahl SS rats fed HF exhibit higher aaPVAT basal lipolysis that may be driven by ATGL. In contrast, demand lipolysis, controlled by HSL activity, is reduced. Dysregulated basal lipolysis may lead to alterations in PVAT FA trafficking, enhance AA availability, and promote the biosynthesis of inflammatory oxylipins, thus impairing its vasoactive functions.

Challenges in Understanding the Biological and Pharmacological Responses Based on Emergent Complexity in Biological Systems: From Bone Metabolism to General Physiology

Biological systems are complex, and although researchers strive to understand them, the accumulated knowledge often complicates integrative comprehension. Consolidating this knowledge can provide insights into the landscape of specific biological events. Our study on bone metabolism, focusing on the behavior of the receptor activator of nuclear factor kappa B (RANK) and its ligand (RANKL) highlighted the challenges in understanding its role across different cell types. At the same time, the study underscores the importance of exploring interactions between various players (cell types and genes/proteins) in complex systems, which is a core focus of systems biology. Analysis by mathematical models is a potentially powerful tool for describing the dynamic behavior of components in the interaction networks. However, such model-based analyses are limited by parameter availability and reliability. To address this, we proposed two approaches, i.e., sequential simulation and system-wide behavior constraints. Sequential simulation of small dynamic models offers potential in reproducing behavior in larger networks, as seen in toxicity analysis of sunitinib-related adverse effects. System-wide constraints derived from "homeostasis" help reduce the parameter search space in large-scale models, as demonstrated in model-based analysis of the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the arachidonic acid pathway. These analytical approaches offer insights into biological system dynamics and can enhance our understanding of pharmacological effects that result from perturbations in complexities of biological systems.

Soil and stone terraces offset the negative impacts of sloping cultivation on soil microbial diversity and functioning by protecting soil carbon

Cultivation of sloping land is a main cause for soil erosion. Conservation practices, such as soil and stone terraces, may reduce the impacts of erosion but their impacts on soil microbial diversity and functioning related to carbon (C) and nutrient metabolisms remain unclear. This study was conducted to evaluate the effects of slope gradients (5°, 8°, 15°, 25°) and conservation practices (cultivated, uncultivated, soil terrace, and stone terrace) on bacterial and fungal diversities, metagenomic and metabolomic functioning associated with basic soil properties. Our results showed that steep slopes at 25° significantly decreased soil pH, silt percentage, and bacterial and fungal abundances, but that soil and stone terraces increased soil organic C (SOC), silt and clay contents, and fungal abundance compared to sloping cultivated lands. In addition, soil and stone terraces increased both bacterial and fungal alpha diversities, and relative abundances of Crenarchaeota, Nitrospirota, and Latescibacterota, but reduced the proportions of Actinobacteriota and Patescibacteria, thus shifting microbial beta diversities, which were significantly associated with increased SOC and silt content. For metagenomics, soil and stone terraces greatly increased the relative abundance of functional genes related to Respiration, Virulence, disease and defense, Stress response, and nitrogen and potassium metabolisms, such as Denitrification and Potassium homeostasis. For soil metabolomics, a total of 22 soil metabolites was enriched by soil and stone terraces, such as Lipids and lipid-like molecules (Arachidonic acid, Gamma-Linolenic acid, and Pentadecanoic acid), and Organoheterocyclic compounds (Adenine, Laudanosine, Methylpyrazine, and Nicotinic acid). To sum up, soil and stone terraces could reduce some of the negative impacts of steep slope cultivation on soil microbial diversity as well as their metagenomic and metabolomic functioning related to C and nutrient metabolism useful for soil health improvement, potentially bolstering the impact of sustainable practices in erosion hotspots around the world.

The Omega-6 Lipid pathway shift is associated with neutrophil influx and structural lung damage in early cysticfibrosis lung disease.

In cystic fibrosis (CF), an imbalanced lipid metabolism is associated with lung inflammation. Little is known about the role that specific lipid mediators (LMs) exert in CF lung inflammation, and whether their levels change during early disease progression. Therefore, we measured airway LM profiles of young CF patients, correlating these with disease-associated parameters. Levels of omega (ω)-3/6 PUFAs and their LM derivatives were determined in bronchoalveolar lavage fluid (BALF) of children with CF ages 1-5 using a targeted high-performance liquid chromatography-tandem mass spectrometry approach. Hierarchical clustering analysis was performed on relative LM levels. Individual relative LM levels were correlated with neutrophilic inflammation (BALF %Neu) and structural lung damage (PRAGMA-CF %Disease). Significant correlations were included in a backward multivariate linear regression model to identify the LMs that are best related to disease progression. A total of 65 BALF samples were analysed for ω-3/6 lipid content. LM profiles clustered into an arachidonic acid (AA)-enriched and a linoleic acid (LA)-enriched sample cluster. AA derivatives like 17-OH-DH-HETE, 5-HETE, 5,15-diHETE, 15-HETE, 15-KETE, LTB4 and 6-trans-LTB4 positively correlated with BALF %Neu and/or PRAGMA %Dis. Contrastingly, 9-HoTrE and the LA derivatives 9-HoDE, 9(10)-EpOME, 9(10)-DiHOME, 13-HoDE, 13-oxoODE and 12(13)-EpOME negatively correlated with BALF %Neu and/or PRAGMA %Dis. 6-trans-LTB4 was the strongest predictor for BALF %Neu. 5-HETE and 15-KETE contributed most to PRAGMA %Dis prediction. Our data provide more insight into the lung lipidome of infants with CF, and show that a shift from LA derivatives to AA derivatives in BALF associates with early CF lung disease progression.

Abstract P358: Interaction of Cytochrome P450 (CYP) 4A10 and CYP1B1 in the Paraventricular Nucleus in the Angiotensin II-induced Hypertension and Neuroinflammation in Female Mice

We have shown that 17β-estradiol (E2)-cytochrome P450 (CYP) 1B1 and catechol-ο-methyltrasnferase-generated metabolite 2-methoxyestradiol (2-ME) in the paraventricular nucleus (PVN) protects against angiotensin (Ang) II-induced hypertension and neuroinflammation. This study was conducted to determine the relationship between CYP4A10 that is expressed in the PVN and metabolizes arachidonic acid (AA) into prohypertensive eicosanoid, 20-hydroxyeicosatetraenoic acid (20-HETE), and CYP1B1 in Ang II-induced hypertension, neuroinflammation, and reactive oxygen species (ROS) production in female mice. Systemic Ang II infusion (700 ng/kg/min, s.c., two weeks) and transduction in the PVN with adenovirus (Ad)-GFP scrambled (Scr)-short hairpin (sh) RNA (200 nL bilaterally, 6.4×10 11 pfu/mL, single injection) produced a significant increase in systolic blood pressure (SBP, tail-cuff) at Day 12 compared to Day 0 (mmHg, 114±3 vs 151±3 respectively, P<0.05, n=6/group) in wild-type (WT) and a much larger increase in CYP1B1 knockout (KO) female mice having E2 but not 2-ME (119±4 vs 173±6 respectively, P<0.05, n=5/group). Ad-GFP-CYP4A10 shRNA (200 nL bilaterally, 1.0×10 12 pfu/mL, single injection) but not Ad-GFP Scr-shRNA transduced in the PVN diminished Ang II-induced increase in SBP at Day 12 in WT mice (mmHg, 119±2 vs 122±3 respectively, P<0.05, n=5/group), and CYP1B1KO mice (mmHg, 115±1 vs 133±2 respectively, P<0.05, n=5/group). Similar results were obtained with Ad-GFP-CYP4A10 shRNA compared to Ad-GFP Scr-shRNA transduced in the PVN on mean arterial pressure (MAP) measured by radiotelemetry (Day 12: mmHg, 121±4 vs 152±4 respectively, P<0.05, n=4/group) in CYP1B1 KO mice. The number of TMEM119 + microglia and GFAP + astrocytes, markers of neuroinflammation determined by immunofluorescence, and ROS production by dihydroethidium staining followed the changes in blood pressure produced by Ang II in the above groups. To determine the contribution of central AA-CYP4A10-generated 20-HETE to Ang II-induced hypertension, the effect of 20-HETE receptor GPR75 siRNA administered intracerebroventricularly (Dharmacon, SMARTpool: 0.4 nmol 2 μ l, single injection ) was examined in CYP1B1KO mice. GPR75 siRNA but not its non-target siRNA minimized Ang II-induced increase in SBP (Day 12: mmHg, 132±4 vs 171±3, P<0.05, n=6/group). These data suggest that the 20-HETE receptor antagonist could be useful in treating hypertension and associated neuroinflammation in females with ovarian dysfunction.

The neo-potential therapeutic strategy in preeclampsia: downregulated miR-26a-2-3p motivates endothelial cell injury by targeting 15-LOX-1

Preeclampsia (PE) poses a life-threatening risk for both mothers and babies, and its onset and progression are linked to endothelial injury. The enzyme 15-lipoxygenase-1 (15-LOX-1), critical in arachidonic acid metabolism, is implicated in various diseases, yet its specific role and precise mechanisms in PE remain largely unknown. In this study, we found that 15-LOX-1 and its main metabolite, 15-HETE, were significantly increased in both the placenta and serum of PE patients. This increase was accompanied by elevated levels of endothelial injury markers, including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). A positive correlation between 15-LOX-1 and those markers in the placenta. In Alox15-/- mice, Alox15 deficiency reduced endothelial cell injury in PE-like mice induced by L-NAME. In vitro studies showed that hypoxia-induced upregulation of 15-LOX-1 reduced the cell viability, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs), while increasing apoptosis and inflammatory cell adhesion. Mechanistically, the p38 MAPK pathway was identified as a downstream target of 15-LOX-1. Knocking down 15-LOX-1 or inhibiting p38 MAPK activation improved endothelial cell injury in hypoxia-treated HUVECs. Furthermore, downregulation of miR-26a-2-3p was found to correlate negatively and colocalize with 15-LOX-1 upregulation in the placenta of PE patients. Luciferase reporter assays further confirmed that miR-26a-2-3p directly bind to the 3’UTR of 15-LOX-1, targeting its expression. Moreover, miR-26a-2-3p agomir ameliorated the PE-like phenotype in mice through the 15-LOX-1/p38 MAPK axis, improving endothelial dysfunction. Therefore, our study provides novel insights into the pathogenesis of PE and highlight modulating the miR-26a-2-3p/15-LOX-1/p38 MAPK axis as a potential therapeutic target for PE.

Parallel LC‐MS/MS‐based targeted proteomics and oxylipin metabolomics for a comprehensive investigation of the arachidonic acid cascade in human macrophages

Parallel LC‐MS/MS‐based targeted proteomics and oxylipin metabolomics for a comprehensive investigation of the arachidonic acid cascade in human macrophages

Gut Microbiomics of Sustained Knee Pain in Knee Osteoarthritis Patients.

To examine whether gut microbes were associated with post-surgery sustained knee pain in knee osteoarthritis (OA) patients by a gut microbiomics approach. Total knee replacement (TKR) patients due to primary knee OA were recruited. Sustained knee pain status at least one year after TKR was defined by the Western Ontario and McMaster University Arthritis Index (WOMAC). Fasting plasma sample and fecal sample were collected. Metabolomic profiling was performed on fasting plasma. 16S rRNA sequencing was performed on fecal samples to determine microbial composition. Twenty TKR patients due to primary knee OA were included in the study with 10 experiencing sustained post-surgery pain and 10 without such pain. Age, sex, and BMI were matched. Linear discriminant analysis of microbiome data identified 13 bacterial taxa that were highly abundant in the pain group, and 5 that were highly abundant in the non-pain group (all P < 0.05). Plasma metabolomic profiling measured 622 metabolites. The correlation analysis indicated that the 18 taxa were significantly correlated with 231 metabolites (all P < 0.05). sPLS-DA analysis showed that 30 out of the 231 metabolites explained 29% of total variance and can be used to clearly separate sustained knee pain patients from non-pain patients. Pathway enrichment analysis showed that these significant metabolites were enriched in arachidonic acid metabolic pathway, bile acid biosynthesis, and linoleic acid metabolism. The gut microbes may play a significant role in sustained knee pain in knee OA patients after TKR potentially through their activation of inflammatory pathways, lipid metabolism, and central sensitization.

Huangqi Guizhi Wuwu Decoction Improves Inflammatory Factor Levels in Chemotherapy-induced Peripheral Neuropathy by Regulating the Arachidonic Acid Metabolic Pathway.

Chemotherapy-induced Peripheral Neuropathy (CIPN) is a common complication that arises from the use of anticancer drugs. Huangqi Guizhi Wuwu Decoction (HGWWD) is an effective classic prescription for treating CIPN; however, the mechanism of the activity is not entirely understood. This study aimed to investigate the remedial effects and mechanisms of HGWWD on CIPN. Changes in behavioral, biochemical, histopathological, and biomarker indices were used to evaluate the efficacy of HGWWD treatment. Ultra-high-performance liquid chromatography/mass spectrometry combined with the pattern recognition method was used to screen biomarkers and metabolic pathways related to CIPN. The results of pathway analyses were verified by protein blotting experiments. A total of 29 potential biomarkers were identified and 13 metabolic pathways were found to be involved in CIPN. In addition HGWWD reversed the levels of 19 biomarkers. Prostaglandin H2 and 17α,21-dihydroxypregnenolone were targeted as core biomarkers. This study provides scientific evidence to support the finding that HGWWD mainly inhibits the inflammatory response during CIPN by regulating arachidonic acid metabolism.

Novel Dual COX-2/5-LOX Inhibitory Activity by Chalcone Derivatives: A Safe and Efficacious Anti-inflammatory Agent.

Non-communicable diseases are chronic systemic inflammation in humans that occurs because of enhanced inflammatory mediators of the arachidonic acid cascade. We aimed to explore whether the lead chalcone compounds could exhibit anti-inflammatory activity via dual blockage of COX-2/5-LOX enzymes and their regulatory mechanism. RAW 264.7 macrophages were collected from NCC, Pune, for in-vitro experiments. The IC50 values of chalcone compounds C45 and C64 were calculated. RAW 264.7 macrophages were treated with C45 and C64 (10%, 5%, 2.5%, 0.125%, and 0.0625% concentration). The cell viability was carried out with an MTT assay. The COX-1, COX-2, 5-LOX, PGE2, and LTB4 levels were detected by ELISA-based kits. The in-vivo evaluation was carried out in Male Wistar rats (250-300 g, 7-8 weeks old) with acute and chronic anti-inflammatory models and histopathological studies on the stomach, liver, and kidney. The present study described the in-vitro and in-vivo biological evaluation of dual COX-2/5-LOX inhibitors in chalcone derivatives (C45 and C64) compounds showed the most effective COX-2 and 5-LOX inhibition with IC50 values 0.092 and 0.136 μM respectively. Simultaneously, compound C64 showed comparable selectivity towards COX-2 with a Selectivity Index (SI) of 68.43 compared to etoricoxib, with an SI of 89.32. In-vivo carrageenaninduced rat paw oedema activity, the compound C64 showed a significant reduction in oedema with 78.28% compared to indomethacin with 88.07% inhibition. Furthermore, cotton pelletinduced granuloma activity revealed that compound C64 significantly reduced 32.85% compared with standard 40.13% granuloma inhibition. The chalcone compound C64, (E)-1-(4-Amino-2-hydroxyphenyl)-3-(3,4,5-trimethoxyphenyl)- prop-2-en-1-one was proved to be a potent and novel Dual COX-2/5-LOX inhibitor with improved gastric safety profiling.

The Role of Arachidonic Acid Metabolizing Cytochromes P450 in the Control of Cardiovascular Functions

The Role of Arachidonic Acid Metabolizing Cytochromes P450 in the Control of Cardiovascular Functions

Identifying Potential Human Monoacylglycerol Lipase Inhibitors from the Phytoconstituents of Morinda Citrifolia L. Fruits by in silico Pharmacology and in vitro Study.

Human monoacylglycerol lipase (MGL) is accountable for the hydrolysis of 2-arachidonoylglycerol (2-AG), thus contributing pivotally to neuroprotection because 2-AG is the main source of arachidonic acid, the precursor of prostaglandins production. Inhibiting MGL reduces inflammatory damage in the ischemic brain and enhances cerebral blood flow. Plants have been reported for their neuroprotective effect, such as Morinda citrifolia on pentylenetetrazol (PTZ)-induced kindling seizures in mice, by reducing the seizures and restoring behavioral and biochemical changes, although the mechanism is not described. To evaluate the binding affinity and stability of phytoconstituents in M. citrifolia fruits toward human MGL (PDB ID 3PE6), compared to the known MGL inhibitors (JZL195 and ZYH). The in silico pharmacology study was validated by an in vitro study of the phytosterols and the ethanol extract of M. citrifolia fruits (EEMC) towards MGL. Initially, nine phytoconstituents of M. citrifolia fruits were docked to the catalytic pocket of human MGL (PDB ID: 3PE6), and compounds with the best affinity were subjected to a molecular dynamic (MD) simulation. The in vitro study was performed using the MGL inhibitor screening assay kit. The best binding affinity and stability toward human MGL were shown by stigmasterol and beta-sitosterol, and the MM-PBSA total binding energy of stigmasterol and beta-sitosterol to MGL is stronger than that of JZL195 and ZYH. Moreover, beta-sitosterol and EEMC inhibit MGL with an IC50 value of, respectively, 8.10μg/mL and 196.20μg/mL, while JZL195 shows an IC50 of 0.028μg/mL. Beta-sitosterol of Morinda citrifolia fruits may have the potential to protect human neurons by occupying the catalytic site of human MGL, thus competitively inhibiting the substrate of the enzyme. However, the inhibitory activity towards human MGL is lower than JZL195.

Biological Evaluation of Lysionotin: a Novel Inhibitor of 5-Lipoxygenase for Anti-glioma.

To explore the potential mechanism of lysionotin in treating glioma. First, target prediction based on Bernoulli Naïve Bayes profiling and pathway enrichment was used to predict the biological activity of lysionotin. The binding between 5-lipoxygenase (5-LO) and lysionotin was detected by surface plasmon resonance (SPR) and molecular docking, and the inhibitory effects of lysionotin on 5-LO and proliferation of glioma were determined using enzyme inhibition assay in vitro and cell viability analysis, respectively. Furthermore, the pharmaceutical effect of lysionotin was explored by cell survival rate analysis and liquid chromatography with tandem mass spectrometry (LC-MS/MS). The protein expression, intracellular calcium ion concentration and cytoskeleton detection were revealed by Western blot, flow cytometry and fluorescence labeling, respectively. Target prediction and pathway enrichment revealed that lysionotin inhibited 5-LO, a key enzyme involved in the arachidonic acid metabolism pathway, to inhibit the proliferation of glioma. Molecular docking results demonstrated that 5-LO can be binding to lysionotin through hydrogen bonds, forming bonds with His600, Gln557, Asn554, and His372. SPR analysis further confirmed the interaction between 5-LO and lysionotin. Furthermore, enzyme inhibition assay in vitro and cell survival rate analysis revealed that 50% inhibition concentration of lysionotin and the median effective concentration of lysionotin were 90 and 16.58 µmol/L, respectively, and the results of LC-MS/MS showed that lysionotin inhibited the production of 5S-hydroperoxy-eicosatetraenoic acid (P<0.05), and moreover, the LC-MS/MS results indicated that lysionotin can enter glioma cells well (P<0.01) and inhibit their proliferation. Western blot analysis demonstrated that lysionotin can inhibit the expression of 5-LO (P<0.05) and downstream leukotriene B4 receptor (P<0.01). In addition, the results showed that lysionotin affected intracellular calcium ion concentration by inhibiting 5-LO to affect the cytoskeleton, as determined by flow cytometry and fluorescence labeling. Lysionotin binds to 5-LO could suppress glioma by inhibiting arachiodonic acid metabolism pathway.

Transcriptome analysis and functional study of phospholipase A2 in Galleria mellonella larvae lipid metabolism in response to envenomation by an ectoparasitoid, Iseropus kuwanae.

There is abundant evidence that parasitoids manipulate their hosts by envenomation to support the development and survival of their progeny before oviposition. However, the specific mechanism underlying host nutritional manipulation remains largely unclear. To gain a more comprehensive insight into the effects induced by the gregarious ectoparasitoid Iseropus kuwanae (Hymenoptera: Ichneumonidae) on the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae) larvae, we sequenced the transcriptome of both non-envenomed and envenomed G. mellonella larvae, specifically targeting genes related to lipid metabolism. The present study revealed that 202 differentially expressed genes (DEGs) were identified and 9 DEGs were involved in lipid metabolism. The expression levels of these 9 DEGs relied on envenomation and the duration post-envenomation. Further, envenomation by I. kuwanae induced an increase in triglyceride (TG) level in the hemolymph of G. mellonella larvae. Furthermore, silencing GmPLA2 in G. mellonella larvae 24h post-envenomation significantly decreased the content of 4 unsaturated fatty acids and TG levels in the hemolymph. The content of linoleic acid and α-linoleic acid were significantly decreased and the content of oleic acid was significantly increased by exogenous supplement of arachidonic acid. Meanwhile, the reduction in host lipid levels impairs the growth and development of wasp offspring. The present study provides valuable knowledge about the molecular mechanism of the nutritional interaction between parasitoids and their hosts and sheds light on the coevolution between parasitoids and host insects.

Multi-Omics Reveals the Role of Arachidonic Acid Metabolism in the Gut-Follicle Axis for the Antral Follicular Development of Holstein Cows.

In vitro embryonic technology is crucial for improving farm animal reproduction but is hampered by the poor quality of oocytes and insufficient development potential. This study investigated the relationships among changes in the gut microbiota and metabolism, serum features, and the follicular fluid metabolome atlas. Correlation network maps were constructed to reveal how the metabolites affect follicular development by regulating gene expression in granulosa cells. The superovulation synchronization results showed that the number of follicle diameters from 4 to 8 mm, qualified oocyte number, cleavage, and blastocyst rates were improved in the dairy heifers (DH) compared with the non-lactating multiparous dairy cows (NDC) groups. The gut microbiota was decreased in Rikenellaceae_RC9_gut_group, Alistipes, and Bifidobacterium, but increased in Firmicutes, Cyanobacteria, Fibrobacterota, Desulfobacterota, and Verrucomicrobiota in the NDC group, which was highly associated with phospholipid-related metabolites of gut microbiota and serum. Metabolomic profiling of the gut microbiota, serum, and follicular fluid further demonstrated that the co-metabolites were phosphocholine and linoleic acid. Moreover, the expression of genes related to arachidonic acid metabolism in granulosa cells was significantly correlated with phosphocholine and linoleic acid. The results in granulosa cells showed that the levels of PLCB1 and COX2, participating in arachidonic acid metabolism, were increased in the DH group, which improved the concentrations of PGD2 and PGF2α in the follicular fluid. Finally, the expression levels of apoptosis-related proteins, cytokines, and steroidogenesis-related genes in granulosa cells and the concentrations of steroid hormones in follicular fluid were determinants of follicular development. According to our results, gut microbiota-related phosphocholine and linoleic acid participate in arachidonic acid metabolism in granulosa cells through the gut-follicle axis, which regulates follicular development. These findings hold promise for enhancing follicular development and optimizing oocyte quality in subfertile dairy cows.

Abstract P206: Renal hemodynamic and transcriptomic changes in response to salt in Dahl salt-sensitive rats

Introduction: Continuous measurements (24/7) of arterial pressure (AP) and renal blood flow (RBF), along with intermittent sampling of arterial and renal venous blood and urine in freely moving rats, have enabled the determination of sequential changes in global substrate metabolism and their association with physiological responses in the kidney. It was found that salt loading in Sprague-Dawley (SD) rats resulted in an increase in RBF and renal O 2 consumption with minimal changes in AP. At the same time, TCA cycle pathway was downregulated with reduced metabolism of free fatty acids and amino acids, while glycolysis was upregulated, in the kidney cortex (Cx). In contrast, no significant changes were observed in metabolism-related pathways in the outer medulla (OM). (PMID: 37575482). Here, we report transcriptomic responses of Dahl salt-sensitive (SS) rats to the HS diet as compared to the salt-resistant SD rats. Method: Male SS rats were fed a 0.4% NaCl (LS) diet. At 8 weeks of age, the rats were implanted with an RBF probe together with an arterial and a renal venous catheter. RBF and AP were measured continuously, and arterial and renal venous blood and urine were sampled when rats were fed the LS and on days 7, 14, and 21 after switching to the 4.0% NaCl (HS) diet. From separate groups of rats subjected to the same protocol, Cx and OM were removed for mRNAseq analysis (Novogene, Inc). Results: When switching to the HS diet, mean AP of SS rats rose from 122 ± 2 to 164 ± 5 mmHg by HS21. RBF (mL/min/g kidney weight) fell significantly over the 3 weeks of the HS diet averaging 7.2 ± 0.6 (LS) to 4.6 ± 0.7 (HS21). The gene set enrichment analysis (GSEA) of the mRNAseq data revealed that only a few metabolic pathways were enriched in HS7 in Cx such as glycosphingolipid biosynthesis, while metabolic pathways such as linolenic acid and arachidonic acid metabolism and glycosphingolipid biosynthesis were enriched in OM. Downregulation of the lysine degradation and glutathione metabolic pathways was observed in both Cx and OM in HS21. In general, fewer metabolic pathways responded to HS in SS rats compared to SD in Cx (22 in SD vs 7 in SS). Conclusion: The Cx of SS rats appear less capable of adjusting to the increased metabolic needs imposed by a HS diet compared to SD rats in contrast to the OM. The functional implications of this are being examined and the metabolomic analysis of blood, tissue and urine samples is currently in progress at the JAX lab.

Study on the Immunomodulatory effect of Qixian Decoction in an Asthmatic Mice Model Based on Serum Metabolomics

AbstractThe study aimed to investigate the immunomodulatory effect of Qixian Decoction (QXT) in an asthmatic model. In this study, ovalbumin (OVA)-induced asthma in female SPF BALB/c mice was established. Mice were randomly divided into four groups (n = 8): a control group, an OVA model group, a low-dose Qixian Granules (KLL) group, and a high-dose Qixian Granules (KLH) group. Mice in the KLL and KLH groups were given the Qixian Granules at a dose of 8 and 16 g/kg, respectively. After the treatment, the lung pathology was evaluated. The expression of inflammatory factors was determined. Serum metabolomics was used to investigate the overall regulation of QXT on the metabolism of asthmatic mice. Our data showed that QXT significantly increased the expression levels of Th1-related interferon-γ, Treg-related interleukin (IL)-10, and transforming growth factor-β1 while decreasing Th1-related tumor necrosis factor α levels in bronchoalveolar lavage fluid, and Th2-related IL-4 and IL-5 levels in serum when compared with the model group (all p &lt; 0.05). Serum metabolomics revealed 28 potential biomarkers associated with nine pathways. Compared with the control group, 19 different metabolites in the KLL group and 18 different metabolites in the KLH were reversed. QXT's therapeutic effect against asthma might be related to glycerophospholipid metabolism and arachidonic acid metabolism. In conclusion, QXT could ameliorate inflammation of the OVA-induced asthmatic mice, mainly by regulating the expression of immune-related factors, probably through regulating the Th1/Th2 immune balance and promoting the proliferation of Treg.

A Nematode Isolate, Oscheius Tipulae, Exhibiting a Wide Entomopathogenic Spectrum and its Application to Control Dipteran Insect Pests.

An entomopathogenic nematode, Oscheius tipulae, was isolated from a soil sample. The identification of this species was supported by morphological and molecular markers. The nematode isolate exhibited pathogenicity against different target insects including lepidopteran, coleopteran, and dipteran insects. The virulence of this nematode was similar to that of a well-known entomopathogenic nematode, Steinernema carpocapsae, against the same insect targets. A comparative metagenomics analysis of these two nematode species predicted the existence of a combined total of 272 bacterial species in their intestines, of which 51 bacterial species were shared between the two nematode species. In particular, the common gut bacteria included several entomopathogenic bacteria including Xenorhabdus nematophila, which is known as a symbiotic bacterium to S. carpocapsae. The nematode virulence of O. tipulae to insects was enhanced by an addition of dexamethasone but suppressed by an addition of arachidonic acid, suggesting that the immune defenses of the target insects against the nematode infection is mediated by eicosanoids, which would be manipulated by the symbiotic bacteria of the nematode. Unlike S. carpocapsae, O. tipulae showed high virulence against dipteran insects including fruit flies, onion flies, and mosquitoes. O. tipulae showed particularly high control efficacies against the onion maggot, Delia platura, infesting the Welsh onion in the rhizosphere in both pot and field assays.