Pepper root exudate alleviates cucumber root-knot nematode infection by recruiting a rhizobacterium.

Root-knot nematodes (Meloidogyne spp.) have garnered significant attention from researchers due to their substantial damage to crops and worldwide distribution. However, controlling this nematode disease is challenging which results from limited chemical pesticides and biocontrol agents effective against them. Here, we demonstrate that pepper-rotation markedly reduces Meloidogyne incognita infection in cucumber and diminishes the presence of p-hydroxybenzoic acid in the soil, a compound known to exacerbate M. incognita infection. Pepper-rotation also structures the rhizobacterial community, leading to the colonization of two Pseudarthrobacter oxydans strains (RH60 and RH97) in the cucumber rhizosphere, facilitated by palmitic acid enrichment in pepper root exudates. Furthermore, both strains exhibit high nematocidal activity against M. incognita, and possess the ability to biosynthesize indoleacetic acid and biodegrade p-hydroxybenzoic acid. RH60 and RH97 additionally induce systemic resistance in cucumber plants and promote their growth. These data suggest that pepper root-exudate palmitic acid alleviates M. incognita infection by recruiting beneficial P. oxydans in the cucumber rhizosphere. Our analyses identify a novel chemical component in root exudates and uncover its pivotal role in crop rotation for disease attenuation, providing intriguing insights into the keystone function of root exudates in plant protection against root-knot nematode infection.

Palmitic acid inhibits macrophage-mediated chemotherapy resistance in multiple myeloma via ALOX12 signaling.

We previously discovered that macrophages (MΦs), especially tumor-associated MΦs (tMΦs), contribute to chemotherapy resistance in multiple myeloma (MM). However, the mechanism underlying MΦ-mediated chemotherapy resistance in MM needs further elucidation, and the identification of factors that preferentially abrogate MΦ-induced inhibition of MM chemotherapy may have important clinical significance. In this study, we showed that the expression of FASN and SCD2, the enzymes that synthesize palmitic acid and convert it to palmitoleic acid, was decreased in tMΦs compared with MΦs. Interestingly, palmitic acid abrogated the MΦ-mediated protection of MM cells from the effects of bortezomib and melphalan in vitro. Combination treatment with palmitic acid and bortezomib or melphalan further inhibited MM tumor growth in vivo. Mechanistically, palmitic acid treatment increased ALOX12 expression in MΦs. ALOX12 inhibition partially abrogated the palmitic acid-induced decrease in MΦ-mediated MM cell survival. Palmitic acid treatment inhibited AMPK signaling in MΦs, and ALOX12 knockdown activated the AMPK signaling pathway in MΦs. AMPK inhibition decreased the MΦ-mediated protection of drug-treated MM cells, and AMPK activation partially abolished the palmitic acid-induced inhibition of MΦ-mediated protection. ALOX12 converts arachidonic acid (AA) to 12-HETE. Moreover, treatment with AA but not 12-HETE partially abrogated the inhibitory effect of palmitic acid on MΦ-mediated MM cell survival in response to bortezomib or melphalan. Overall, we identified palmitic acid as a factor that inhibits MΦ-mediated resistance to bortezomib and melphalan in MM, which may have clinical significance.

Chromium and Palmitic Acid Supplementation Modulate Adipose Tissue Insulin Sensitivity in Postpartum Dairy Cows.

Periparturient dairy cows exhibit intense lipolysis driven by reduced dry matter intake, enhanced energy needs, and the loss of adipose tissue (AT) insulin sensitivity. Extended periods of low insulin sensitivity and negative energy balance induce lipolysis dysregulation, leading to increased disease susceptibility and poor lactation performance. Chromium (Cr) supplementation improves systemic insulin sensitivity, while palmitic acid (PA) increases energy availability for milk production. However, the effect of supplementing Cr and PA alone or in combination on insulin sensitivity in AT is unknown. Thirty-two multiparous cows were used in a randomized complete block design experiment and randomly assigned to one of 4 diets fed from 1 to 24 DIM. Diets included: control, no supplementation (CON, n = 8); Cr (Cr-propionate at 0.45 ppm Cr/kg DM, n = 8); PA (1.5% DM, n = 8); or Cr+PA (n = 8). Plasma samples were collected at -13 ± 5.1 d prepartum (PreP), and 14.4 ± 1.9d (PP1) and 21 ± 1.9d (PP2) after calving for albumin, BHB, BUN, calcium, cholesterol, glucose, nonesterified fatty acids (NEFA), total protein, iron, transferrin, triglycerides, and oxylipids quantification. Subcutaneous AT (SCAT) explants were collected at PreP, PP1 and PP2 and incubated in the presence of the lipolytic agent isoproterenol (ISO = 1 µM, BASAL = 0 µM) for 3 h. The antilipolytic effect of insulin (1µL/L) on SCAT explants was evaluated during ISO stimulation (IN+ISO). Lipolysis was quantified by glycerol release in the media (nmol glycerol/mg AT). Macrophage infiltration and adipocyte size were measured using hematoxylin and eosin-stained AT sections and immunohistochemistry. Cr tended to reduce postpartum NEFA concentrations when compared with CON, PA, and Cr+PA. Likewise, Cr increased the percentage of large adipocytes (>9000 µm2) postpartum compared with other diets. In line with higher lipid content, Cr-fed cows had higher ex-vivo BASAL lipolysis at PP2 when compared with PA and Cr+PA. ISO induced higher lipolysis at PP1 and PP2 but it was not affected by Cr and PA. IN+ISO reduced lipolysis by 29.91 ± 11% in Cr compared with ISO. In contrast, IN+ISO did not affect ISO lipolysis in CON, PA, and Cr+PA. Plasma transferrin was reduced by Cr. At PP2, PA cows had 3.3-fold higher macrophage infiltration in SCAT when compared with CON and Cr. Plasma 9-HODE and 9-oxoODE were increased by Cr+PA. PA increased plasma 13-oxoODE and Cr increased the ratio of 13-HODE:13-oxoODE. PA increased 5-iso Prostaglandin F2α-VI. Our results demonstrate that supplementing Cr during the immediate postpartum enhances SCAT insulin sensitivity and lipid accumulation. Further studies should determine the effects and mechanisms of action of Cr and PA on AT lipogenesis, adipogenesis, and their impact on lactation performance.

Promotion of maturation in CDM3-induced embryonic stem cell-derived cardiomyocytes by palmitic acid.

BACKGROUND: Myocardial infarction leads to myocardial necrosis, and cardiomyocytes are non-renewable. Fatty acid-containing cardiomyocyte maturation medium promotes maturation of stem cell-derived cardiomyocytes. OBJECTIVE: To study the effect palmitic acid on maturation of cardiomyocytes derived from human embryonic stem cells (hESCs) to optimize differentiation for potential treatment of myocardial infarction by hESCs. METHODS: hESCs were differentiated into cardiomyocytes using standard chemically defined medium 3 (CDM3). Up to day 20 of differentiation, 200 Mm palmitic acid were added, and then the culture was continued for another 8 days to mimic the environment in which human cardiomyocytes mainly use fatty acids as the main energy source. Light microscopy, transmission electron microscopy, immunofluorescence, reverse transcription-polymerase chain reaction, and cellular ATP assays, were carried out to analyze the expression of relevant cardiomyocyte-related genes, cell morphology, metabolism levels, and other indicators cardiomyocyte maturity. RESULTS: Cardiomyocytes derived from hESCs under exogenous palmitic acid had an elongated pike shape and a more regular arrangement. Sarcomere stripes were clear, and the cells color was clearly visible. The cell perimeter and elongation rate were also increased. Myogenic fibers were abundant, myofibrillar z-lines were regularly, the numbers of mitochondria and mitochondrial cristae were higher, more myofilaments were observed, and the structure of round-like discs was occasionally seen. Expression of mature cardiomyocyte-associated genes TNNT2, MYL2 and MYH6, and cardiomyocyte-associated genes KCNJ4, RYR2,and PPARα, was upregulated (p < 0.05). Expression of MYH7, MYL7, KCND2, KCND3, GJA1 and TNNI1 genes was unaffected (p > 0.05). Expression of mature cardiomyocyte-associated sarcomere protein MYL2 was significantly increased (p < 0.05), MYH7 protein expression was unaffected (p > 0.05). hESC-derived cardiomyocytes exposed to exogenous palmitic acid produced more ATP per unit time (p < 0.05). CONCLUSION: Exogenous palmitic acid induced more mature hESC-CMs in terms of the cellular architecture, expression of cardiomyocyte maturation genes adnprotein, and metabolism.

The aroma transformation of Japanese sea bass (Lateolabrax japonicas) through endogenous enzyme incubation during the lag phase of attached microorganisms.

Endogenous enzymes play a crucial role in determining fish product aroma. However, the attached microorganisms can promote enzyme production, making it challenging to identify specific aromatic compounds resulting from endogenous enzymes. Thus, we investigated the aroma transformation of Japanese sea bass through enzymatic incubation by controlling attached microorganisms during the lag phase. Our results demonstrate that enzymatic incubation significantly enhances grassy and sweet notes while reducing fishy odors. These changes in aroma are associated with increased levels of 10 volatile compounds and decreased levels of 3 volatile compounds. Among them, previous studies have reported enzyme reaction pathways for octanal, 1-nonanal, vanillin, indole, linalool, geraniol, citral, and 6-methyl-5-hepten-2-one; however, the enzymatic reaction pathways for germacrene D, beta-caryophyllene, pristane, 1-tetradecene and trans-beta-ocimene remain unclear. These findings provide novel insights for further study to elucidate the impact of endogenous enzymes on fish product aromas.

Green enrichment of argan oil (Argania spinosa L.) with thyme (Thymus vulgaris L.) and oregano (Origanum vulgare L.) leaves: Evaluating quality and stability improvements.

This study aimed to assess the impact of enriching argan oil (AO) (Argania spinosa L.) using the maceration technique with thyme (Thymus vulgaris L.) and oregano (Origanum vulgare L.) leaves (TL and OL) at two proportions (5 and 10%). The oxidative stability of the control and enriched oils was examined under accelerated conditions at a temperature of 60 °C for 120 days (4 months). Quality indices (Free fatty acids (FFA), peroxide value (PV), p-anisidine value (p-AV), ultraviolet absoptions (K232 and K270), Rancimat test, fatty acids composition, sensory attributes, simple phenolic contents (SPC) and antioxidant activity (DPPH•) were determined. As a simple, inexpensive and green method, enrichment by maceration yielded advantageous results. Compared to the control (68.05 ± 1.10 mg GAE/kg), the SPC significantly increased in enriched oils reaching notably 250.9 ± 9.1 mg GAE/kg when adding 10% of TL. Also, the enriched oil samples showed the lowest PV, p-AV and ultraviolet absorptions compared with the control. However, no noticeable changes were reported in fatty acids composition and iodine value. In terms of sensory attributes, enrichment by maceration masked the rancid odour caused by oxidation. These scientific discoveries inherently yield economic advantages by enabling the diversification of product offerings, simultaneously catering to a broader market seeking high-quality oils infused with herbs, including both AO and aromatic plants.

Palmitic acid causes hepatocyte inflammation by suppressing the BMAL1-NAD+-SIRT2 axis.

Palmitic acid is the most abundant saturated fatty acid in circulation and causes hepatocyte toxicity and inflammation. As saturated fatty acid can also disrupt the circadian rhythm, the present work evaluated the connection between clock genes and NAD+ dependent Sirtuins in protecting hepatocytes from lipid-induced damage. Hepatocytes (immortal cells PH5CH8, hepatoma cells HepG2) treated with higher doses of palmitic acid (400-600µM) showed typical features of steatosis accompanied with growth inhibition and increased level of inflammatory markers (IL-6 IL-8, IL-1α and IL-1ß) together with decline in NAD+ levels. Palmitic acid treated hepatocytes showed significant decline in not only the protein levels of SIRT2 but also its activity as revealed by the acetylation status of its downstream targets (Tubulin and NF-ƙB). Additionally, the circadian expression of both SIRT2 and BMAL1 was inhibited in presence of palmitic acid in only the non-cancerous hepatocytes, PH5CH8 cells. Clinical specimens obtained from subjects with NASH-associated fibrosis, ranging from absent (F0) to cirrhosis (F4), showed a significant decline in levels of SIRT2 and BMAL1, especially in the cirrhotic liver. Ectopic expression of BMAL1 or activating SIRT2 by supplementation with nicotinamide riboside (precursor of NAD+) dampened the palmitic acid induced lipoinflammation and lipotoxicity more effectively in PH5CH8 cells as compared to HepG2 cells. Mechanistically, palmitic acid caused transcriptional suppression of SIRT2 by disrupting the chromatin occupancy of BMAL1 at its promoter site. Overall, the work suggested that SIRT2 is a clock-controlled gene that is transcriptionally regulated by BMAL1. In conclusion the activation of the BMAL1-NAD+-SIRT2 axis shows hepatoprotective effects by preventing lipotoxicity and dampening inflammation.

Dysregulation of mitochondrial dynamics and mitophagy are involved in high-fat diet-induced steroidogenesis inhibition.

Male obesity is a pandemic health issue and can disrupt testicular steroidogenesis. Here, we explored the mechanism by which a high-fat diet (HFD) induced steroidogenic inhibition. As expected, HFD induced lipid droplet accumulation and reduced the expression of StAR, P450scc, and 3ß-HSD, three steroidogenic enzymes, in mouse testes. Palmitic acid (PA), a saturated fatty acid usually used to trigger lipotoxicity in vitro, induced greater accumulation of lipid droplets and the downregulation of steroidogenic enzymes in TM3 cells. Mechanistically, both HFD and PA disturbed mitochondrial fusion/fission dynamics and then induced mitochondrial dysfunction and mitophagy inhibition in mouse Leydig cells. Additionally, mitochondrial fusion promoter M1 attenuated PA-induced imbalance of mitochondrial dynamics, mitophagy inhibition, mitochondrial reactive oxygen species (ROS) production, and mitochondrial dysfunction in TM3 cells. Mitofusin 2 (Mfn2) knock-down further aggravated the PA-induced imbalance of mitochondrial dynamics, mitochondrial ROS production, and mitochondrial dysfunction in TM3 cells. Importantly, M1 rescued PA-induced downregulation of steroidogenic enzymes, whereas Mfn2 knock-down further aggravated PA-induced downregulation of steroidogenic enzymes in TM3 cells. Overall, our results provide laboratory evidence that mitochondrial dysfunction and mitophagy inhibition caused by dysregulation of mitochondrial fusion may be involved in HFD-induced steroidogenesis inhibition in mouse Leydig cells.

Unraveling brain palmitic acid: Origin, levels and metabolic fate.

In the human brain, palmitic acid (16:0; PAM) comprises nearly half of total brain saturates and has been identified as the third most abundant fatty acid overall. Brain PAM supports the structure of membrane phospholipids, provides energy, and regulates protein stability. Sources underlying the origin of brain PAM are both diet and endogenous synthesis via de novo lipogenesis (DNL), primarily from glucose. However, studies investigating the origin of brain PAM are limited to tracer studies utilizing labelled (14C/11C/3H/2H) PAM, and results vary based on the model and tracer used. Nevertheless, there is evidence PAM is synthesized locally in the brain, in addition to obtained directly from the diet. Herein, we provide an overview of brain PAM origin, entry to the brain, metabolic fate, and factors influencing brain PAM kinetics and levels, the latter in the context of age, as well as neurological diseases and psychiatric disorders. Additionally, we briefly summarize the role of PAM in signaling at the level of the brain. We add to the literature a rudimentary summary on brain PAM metabolism.

Isopropyl 3-(3,4-Dihydroxyphenyl)-2-hydroxypropanoate Alleviates Palmitic Acid-Induced Vascular Aging in HUVEC Cells through ROS/Ferroptosis Pathway.

Vascular aging is an important factor leading to cardiovascular diseases such as hypertension and atherosclerosis. Hyperlipidemia or fat accumulation may play an important role in vascular aging and cardiovascular disease. Isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate (IDHP) has biological activity and can exert cardiovascular protection, which may be related to ferroptosis. However, the exact mechanism remains undefined. We hypothesized that IDHP may have a protective effect on blood vessels by regulating vascular aging caused by hyperlipidemia or vascular wall fat accumulation. The aim of this study is to investigate the protective effect and mechanism of IDHP on palmitic acid-induced human umbilical vein endothelial cells (HUVEC) based on senescence and ferroptosis. We found that IDHP could delay vascular aging, reduce the degree of ferrous ion accumulation and lipid peroxidation, and protect vascular cells from injury. These effects may be achieved by attenuating excessive reactive oxygen species (ROS) and ferroptosis signaling pathways generated in vascular endothelial cells. In short, our study identified IDHP as one of the antioxidant agents to slow down lipotoxicity-induced vascular senescence through the ROS/ferroptosis pathway. IDHP has new medicinal value and provides a new therapeutic idea for delaying vascular aging in patients with dyslipidemia.

A Comparative Study on the Antidiabetic Activity, Cytotoxicity and Lipid Profile of Trichilia emetica Oils.

The Trichilia emetica plant is traditionally used for medicinal and food purposes. However, there are limited studies on the bioactivity and cytotoxicity of its seed butter and aril oil. This study aimed to assess the antidiabetic activity and cytotoxicity of seed butter and aril oil, obtained via two different extraction methods, and compare their lipid profiles. The plant samples were collected from the Faifa mountains and extracted using a Soxhlet apparatus for hot extraction and a magnetic stirrer for cold maceration. The antidiabetic activity and cytotoxicity were evaluated using the α-amylase and MTT assays, respectively. The fatty acids were quantified utilizing gas chromatography-mass spectrometry. This study proves the impact of the extraction method on the yield, cytotoxicity, antidiabetic activity and lipid profile. The highest cytotoxicity was observed with the seed butter obtained via Soxhlet extraction. The α-amylase inhibition was observed at the highest levels with the seed butter and aril oil obtained via cold maceration. The palmitic acid (PA) and oleic acid (OA) were detected at their maximal concentrations in the seed butter obtained via Soxhlet extraction and aril oil obtained via cold maceration, respectively. This study represents an essential basis for understanding the importance of T. emetica as a valuable tree for food, cosmetic and medicinal purposes. Further experiments can lead to the development of green extraction techniques and isolation of the cytotoxic and antidiabetic molecules that can be developed into new pharmaceutical products or serve as lead molecules for new drugs.

Palmitic acid-mediated modulation of crystallization dynamics in amylose microparticle formation: From spherical to macaron and disc shapes.

Here, we investigated the complexation of short chain amylose (SCAs) and palmitic acid (PA), serving as polymeric building blocks that alter the selectivity and directionality of particle growth. This alteration affects the shape anisotropy of the particles, broadening their applications due to the increased surface area. By modifying the concentration of PA, we were able to make spherical, macaron, and disc-shaped particles, demonstrating that PA acts as a structure-directing agent. We further illustrated the lateral and longitudinal stacking kinetics between PA-SCA inclusion complexes during self-assembly, leading to anisotropy. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed the structural difference between the initial and final morphologies of palmitic acid-short chain amylose particles (PA-SCAPs) compared to those of short-chain amylose particle (SCAPs). The presence of PA-SCA inclusion complex in the anisotropic particles was confirmed using nuclear magnetic resonance (NMR) and powder x-ray diffraction (XRD) analysis.

Jie-Du-Tong-Luo formula protects C2C12 myotubes against high glucose and palmitic acid injury by activating the PI3K/Akt/PPARγ pathway in vitro.

Introduction: In prior reports, Jie-Du-Tong-Luo (JDTL) was reported to help control insulin secretion and blood glucose in patients with diabetes, while also protecting liver and pancreatic islet cells against injury caused by exposure to high glucose (HG) levels. This study was thus developed to assess the effects of JDTL on HG and palmitic acid (PA)-induced muscle injury and to explore the mechanistic basis for these effects. Methods: A model of muscle injury was established using mouse C2C12 myotubes treated with HG + PA. A proteomics approach was used to assess changes in protein levels following JDTL treatment, after which Western immunoblotting was employed to validate significantly affected pathways. Results: JDTL was able to protect against HG + PA-induced muscle cell injury in this experimental system, altering lipid metabolism and inflammatory activity in these injured C2C12 myotubes. Western blotting suggested that JDTL is capable of activating PI3K/Akt/PPARγ signaling to control lipid metabolism without any corresponding impact on the inflammatory NF-κB pathway. Conclusions: These data highlight the ability of JDTL to protect against HG + PA-induced injury to muscle cells, and suggest that the underlying basis for such efficacy is related to the PI3K/Akt/PPARγ pathway-mediated modulation of lipid metabolism.

Mammary gland responses to altering the supply of de novo fatty acid substrates and preformed fatty acids on the yields of milk components and milk fatty acids.

The objective of our study was to evaluate the effect of altering the dietary supply of acetate, palmitic acid (PA), and cottonseed on the yields of milk components and milk fatty acids (FA) in lactating dairy cows. Thirty-two multiparous Holstein cows (133 ± 57 d in milk, 50.5 ± 7.2 kg/d milk) were used in a 4 × 4 Latin square split plot design with a 2 × 2 factorial arrangement of subplot treatments. Cows were blocked by energy-corrected milk (ECM) yield and allocated to a main plot receiving a basal diet (n = 16) with no supplemental PA (Low PA) or a basal diet (n = 16) with 1.5% inclusion of a FA supplement containing ~85% PA (High PA). In each main plot, the following subplots of treatment diets were fed in a Latin square arrangement consisting of 14-d periods: 1) a control diet (CON), 2) the control diet supplemented with 3% sodium acetate (AC), 3) the control diet supplemented with 12% whole cottonseed (CS), and 4) the control diet supplemented with 3% sodium acetate and 12% whole cottonseed (CS+AC). The PA supplement and sodium acetate replaced soyhulls, and whole cottonseed replaced cottonseed hulls and meal. All diets were balanced for 30% neutral detergent fiber (NDF), 23% forage NDF, 28% starch, and 17% crude protein (CP). Sources of FA were classified as de novo (<16 carbons), mixed (16-carbon), and preformed (>16 carbons). The statistical model included the random effect of cow nested within basal diet and fixed effect of period, basal diet, acetate, cottonseed, and their interactions. Three-way interactions among basal diet, acetate, and cottonseed were observed for the yields of milk fat, 3.5% fat-corrected milk (FCM), and the molar yields of de novo FA, mixed FA, and preformed FA. In the Low PA diets, AC and CS+AC increased the yields of milk fat and FCM compared with CON and CS, whereas, in the High PA diets, CS+AC increased the yields of milk fat and FCM compared with the other treatments and AC increased milk fat yield compared with CON and CS. Compared with Low PA, High PA increased milk fat content, mixed FA yield, and tended to increase C4:0 yield. Diets containing acetate increased DMI and the yields of milk fat, ECM, FCM, de novo FA, mixed FA, and preformed FA compared with diets without acetate. Diets containing cottonseed increased the yields of milk and preformed FA, tended to increase the yields of FCM and protein, and decreased DMI and the yields of de novo FA and mixed FA compared with diets without cottonseed. In summary, in high PA diets, the inclusion of acetate plus cottonseed increased milk fat yield compared with the other treatments. The CON diet in High PA increased milk fat yield to the same extent as AC and CS+AC in Low PA suggesting PA is important for initiating milk TG synthesis. Balancing the supply of de novo FA substrates and preformed FA is important for increasing the synthesis of milk fat triglycerides and milk fat production.

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 molecular mechanism involved. 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 µmol/L of MT pre-treatment attenuated PA-induced mitochondrial ROS and restored mitochondrial respiratory function. Meanwhile, MT pretreatment reversed the upregulation of P62 induced 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.

Protonation of palmitic acid embedded in DPPC lipid bilayers obscures detection of ripple phase by FTIR spectroscopy.

The transformation of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers from the gel (Lß') to the fluid (Lα) phase involves an intermediate ripple (Pß') phase forming a few degrees below the main transition temperature (Tm). While the exact cause of bilayer rippling is still debated, the presence of amphiphilic molecules, pH, and lipid bilayer architecture are all known to influence (pre)transition behavior. In particular, fatty acid chains interact with hydrophobic lipid tails, while the carboxylic groups simultaneously participate in proton transfer with interfacial water in the polar lipid region which is controlled by the pH of the surrounding aqueous medium. The molecular-level variations in the DPPC ripple phase in the presence of 2% palmitic acid (PA) were studied at pH levels 4.0, 7.3, and 9.1, where PA is fully protonated, partially protonated, or fully deprotonated. Bilayer thermotropic behavior was investigated by differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy which agreed in their characterization of (pre)transition at pH of 9.1, but not at pH 4.0 and especially not at 7.3. Owing to the different insertion depths of protonated and deprotonated PA, along with the ability of protonated PA to undergo flip-flop in the bilayer, these two forms of PA show a different hydration pattern in the interfacial water layer. Finally, these results demonstrated the hitherto undiscovered potential of FTIR spectroscopy in the detection of the events occurring at the surface of lipid bilayers that obscure the low-cooperativity phase transition explored in this work.

Eicosapentaenoic Acid Rescues Cav1.2-L-Type Ca2+ Channel Decline Caused by Saturated Fatty Acids via Both Free Fatty Acid Receptor 4-Dependent and -Independent Pathways in Cardiomyocytes.

Dietary intake of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid, EPA) exerts antiarrhythmic effects, although the mechanisms are poorly understood. Here, we investigated the possible beneficial actions of EPA on saturated fatty acid-induced changes in the L-type Ca2+ channel in cardiomyocytes. Cardiomyocytes were cultured with an oleic acid/palmitic acid mixture (OAPA) in the presence or absence of EPA. Beating rate reduction in cardiomyocytes caused by OAPA were reversed by EPA. EPA also retrieved a reduction in Cav1.2 L-type Ca2+ current, mRNA, and protein caused by OAPA. Immunocytochemical analysis revealed a distinct downregulation of the Cav1.2 channel caused by OAPA with a concomitant decrease in the phosphorylated component of a transcription factor adenosine-3',5'-cyclic monophosphate (cAMP) response element binding protein (CREB) in the nucleus, which were rescued by EPA. A free fatty acid receptor 4 (FFAR4) agonist TUG-891 reversed expression of Cav1.2 and CREB mRNA caused by OAPA, whereas an FFAR4 antagonist AH-7614 abolished the effects of EPA. Excessive reactive oxygen species (ROS) accumulation caused by OAPA decreased Cav1.2 and CREB mRNA expressions, which was reversed by an ROS scavenger. Our data suggest that EPA rescues cellular Cav1.2-Ca2+ channel decline caused by OAPA lipotoxicity and oxidative stresses via both free fatty acid receptor 4-dependent and -independent pathways.

Palmitic Acid Modulation of the Insulin-Like Growth Factor System in Hypothalamic Astrocytes and Neurons.

INTRODUCTION: Insulin-like growth factor (IGF)1 and IGF2 have neuroprotective effects, but less is known regarding how other members of the IGF system, including IGF binding proteins (IGFBPs) and the regulatory proteinase pappalysin-1 (PAPP-A) and its endogenous inhibitor stanniocalcin-2 (STC2) participate in this process. Here, we analyzed whether these members of the IGF system are modified in neurons and astrocytes in response to palmitic acid (PA), a fatty acid that induces cell stress when increased centrally. METHODS: Primary hypothalamic astrocyte cultures from male and female PND2 rats and the pro-opiomelanocortin (POMC) neuronal cell line, mHypoA-POMC/GFP-2, were treated with PA, IGF1 or both. To analyze the role of STC2 in astrocytes, siRNA assays were employed. RESULTS: In astrocytes of both sexes, PA rapidly increased cell stress factors followed by increased Pappa and Stc2 mRNA levels and then a decrease in Igf1, Igf2, and Igfbp2 expression and cell number. Exogenous IGF1 did not revert these effects. In mHypoA-POMC/GFP-2 neurons, PA reduced cell number and Pomc and Igf1 mRNA levels, and increased Igfbp2 and Stc2, again with no effect of exogenous IGF1. PA increased STC2 expression, but no effects of decreasing its levels by interference assays or exogenous STC2 treatment in astrocytes were found. CONCLUSIONS: The response of the IGF system to PA was cell and sex specific, but no protective effects of the IGFs were found. However, the modifications in hypothalamic PAPP-A and STC2 indicate that further studies are required to determine their role in the response to fatty acids and possibly in metabolic control.

TRIM65/NF2/YAP1 Signaling Coordinately Orchestrates Metabolic and Immune Advantages in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide. Significantly activated uridine nucleotide and fatty acid metabolism in HCC cells promote malignant proliferation and immune evasion. Herein, it is demonstrated that the tripartite motif 65 (TRIM65) E3 ubiquitin-protein ligase, O-GlcNAcylated via O-GlcNAcylation transferase, is highly expressed in HCC and facilitated metabolic remodeling to promote the accumulation of products related to uracil metabolism and palmitic acid, driving the progression of HCC. Mechanistically, it is showed that TRIM65 mediates ubiquitylation at the K44 residue of neurofibromatosis type 2 (NF2), the key protein upstream of classical Hippo signaling. Accelerated NF2 degradation inhibits yes-associated protein 1 phosphorylation, inducing aberrant activation of related metabolic enzyme transcription, and orchestrating metabolic and immune advantages. In conclusion, these results reveal a critical role for the TRIM family molecule TRIM65 in supporting HCC cell survival and highlight the therapeutic potential of targeting its E3 ligase activity to alter the regulation of proteasomal degradation.

Fatty acid preference for beta-oxidation in mitochondria of murine cultured astrocytes.

The brain utilizes glucose as a primary energy substrate but also fatty acids for the ß-oxidation in mitochondria. The ß-oxidation is reported to occur mainly in astrocytes, but its capacity and efficacy against different fatty acids remain unknown. Here, we show the fatty acid preference for the ß-oxidation in mitochondria of murine cultured astrocytes. Fatty acid oxidation assay using an extracellular flux analyzer showed that saturated or monosaturated fatty acids, palmitic acid and oleic acid, are preferred substrates over polyunsaturated fatty acids like arachidonic acid and docosahexaenoic acid. We also report that fatty acid binding proteins expressed in the astrocytes contribute less to fatty acid transport to mitochondria for ß-oxidation. Our results could give insight into understanding energy metabolism through fatty acid consumption in the brain.