The Lipid-Metabolism-Associated Anti-Obesity Properties of Rapeseed Diacylglycerol Oil.

To investigate the effects of rapeseed diacylglycerol oil (RDG) intake on lipid accumulation and metabolism in C57BL/6J mice, obese mice were fed a high-fat diet in which 45% of the total energy content came from RDG (RDGM group) or rapeseed triacylglycerol oil (RTGM group). This diet intervention was conducted for 12 weeks following the establishment of the obese mouse model. By the end of the experiment, the serum glucose levels of the mice in the RTGM and RDGM groups were 13.0 ± 1.3 mmol/L and 9.7 ± 1.5 mmol/L, respectively. Meanwhile, the serum triglyceride level in the RDGM group was 26.3% lower than that in the RTGM group. The weight-loss effect in the RDGM group was accompanied by a significant decrease in the white adipose tissue (WAT) index. The RDG intervention did not significantly change the antioxidant and anti-inflammatory properties of the rapeseed oil in vivo. The RDG diet improved the liver lipid metabolism abnormalities induced by a high-fat diet, leading to decreased liver damage index values (AST and ALT). Additionally, compared to that in the RTGM group, the expression of the adipogenic genes PPAR-γ and DGAT decreased in both the liver and intestine by 21.7% and 16.7% and by 38.7% and 47.2%, respectively, in the RDGM group. Further, most lipolytic genes in BAT showed no significant change after the RDG intervention. This implies that RDG regulates lipid metabolism by altering the expression of adipogenic genes in the liver, intestine, and adipose tissue, thereby reducing the accumulation of WAT. Furthermore, the RDG diet enhanced gut flora diversity, increasing the relative levels of unclassified Muribaculaceae and decreasing the levels of Dubosiella and Faecalibaculum in the mouse gut, potentially accelerating lipid metabolism. Thus, a three-month RDG diet intervention in obese mice exhibited benefits in regulating the somatotype, serum obesity-related indices, gut flora structure, and lipid metabolism in the adipose tissue, liver, and intestine.

Enhanced anticancer efficacy of primed natural killer cells via coacervate-mediated exogenous interleukin-15 delivery.

Effective exogenous delivery of interleukin (IL)-15 to natural killer (NK) cells with subsequent anticancer efficacy could be a promising immune cell-based cancer immunotherapy. For the protection of encapsulated cargo IL-15 while maintaining its bioactivity under physiological conditions, we utilized a coacervate (Coa) consisting of a cationic methoxy polyethylene glycol-poly(ethylene arginyl aspartate diglyceride) (mPEG-PEAD) polymer, anionic counterpart heparin, and cargo IL-15. mPEGylation into the backbone cation effectively preserved the colloidal stability of Coa in harsh environments and enhanced the protection of cargo IL-15 than normal Coa without mPEGylation. Proliferation and anticancer efficacy of primed NK cells through co-culture with multiple cancer cell lines were enhanced in the mPEG-Coa group due to the maintained bioactivity of cargo IL-15 during the ex vivo expansion of NK cells. These facilitated functions of NK cells were also supported by the increased expression of mRNAs related to anticancer effects of NK cells, including cytotoxic granules, death ligands, anti-apoptotic proteins, and activation receptors. In summary, our Coa-mediated exogenous IL-15 delivery could be an effective ex vivo priming technique for NK cells with sustained immune activation that can effectively facilitate its usage for cancer immunotherapy.

Suppression of tumor progression by thioredoxin-interacting protein-dependent adenosine 2B receptor degradation in a PLAG-treated Lewis lung carcinoma-1 model of non-small cell lung cancer.

Extracellular adenosine in the tumor microenvironment plays a vital role in cancer development. Specifically, activation of adenosine receptors affects tumor cell growth and adenosine release. We examined the anti-tumor efficacy of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) in animal models, revealing the role of PLAG in inhibiting tumor progression by promoting the degradation of adenosine 2B receptors (A2BRs) in tumors. PLAG induced the expression of thioredoxin-interacting protein (TXNIP), a type of α-arrestin that accelerates A2BR internalization by interacting with A2BR complexes containing ß-arrestin. Engulfed receptors bound to TXNIP were rapidly degraded after E3 ligase recruitment and ubiquitination, resulting in early termination of intracellular signals that promote tumor overgrowth. However, in control cancer cells, A2BRs bound to protein phosphatase 2A and were returned to the cell membrane instead of being degraded, resulting in continuous receptor-mediated signaling by pathways including the Raf-Erk axis, which promotes tumor proliferation. A TXNIP-silenced cell-implanted mouse model and TXNIP knockout (KO) mice were used to verify that PLAG-mediated suppression of tumor progression is dependent on TXNIP expression. Increased tumor growth was observed in TXNIP-silenced cell-implanted mice, and the anti-tumor effects of PLAG, including delayed tumor overgrowth, were greatly reduced. However, the anti-tumor effects of PLAG were observed in cancer cell-implanted TXNIP-KO mice, which indicates that PLAG produces anti-tumor effects by enhancing TXNIP expression in tumor cells. These essential functions of PLAG, including delaying tumor growth via A2BR degradation, suggest innovative directions for anticancer drug development.

Soybean diacylglycerol regulates lipid metabolism in D-galactose-induced aging rats by altering gut microbiota and gene expression of colonic epithelial cells.

Lipid metabolism is closely related to the health of aging bodies and its disorder often leads to cardiovascular diseases and chronic diseases. Dietary fat is one of the important sources of body fat, which affects the body's lipid metabolism. However, how dietary fat affects lipid metabolism in aging bodies has not been reported. Thus, the effects of soybean diacylglycerol (DAG) on lipid metabolism in D-galactose-induced aging rats were investigated by detecting the serum biochemical indexes, hepatocyte morphology, gut microbiota changes, and gene expression of colonic epithelial cells. The results showed that DAG alleviated the lipid metabolism disorders, and the hepatocyte morphology of aging rats fed DAG was normal. 16S rDNA analysis showed that DAG restored Eisenbergiella and Veillonella that were missing in aging rats. The relative abundances of Romboutsia and Ruminococcus_2 decreased and the relative abundance of Lachnospiraceae NK4A136 group increased significantly with the influence of DAG (P < 0.05). Gene expression profiles showed that the gene expression of colon epithelial cells was altered by DAG and DAG downregulated the genes Lipe and Fabp4 related to the lipolysis of adipocytes. In conclusion, DAG regulated the lipid metabolism of aging rats by regulating gut microbiota and gene expression of colonic epithelial cells.

Toll-like receptor 2 and 6 agonist fibroblast-stimulating lipopeptide increases expression and secretion of CXCL1 and CXCL2 by uveal melanocytes.

Fibroblast-stimulating lipopeptide (FSL-1) can activate Toll-like receptor 2 and 6 (TLR2/6), which recognize relevant molecules from gram-positive pathogens, fungus, and mycoplasma, and elevates the expression of CXCL1 and CXCL2, neutrophil chemoattractants, in certain types of cells. This effect has not previously been reported in the uveal melanocytes (UM). This study was designed to test the hypothesis that FSL-1 can induce the expression and secretion of CXCL1 and CXCL2 via activation of TLR2/6 in cultured human UM and producing an acute non-infectious uveitis reaction in the mouse. Flow cytometry and fluorescent immunostaining were used to measure the effect of FSL-1 on the expression of TLR2/6 in UM. Real time PCR and ELISA analysis were used to assess the ability of FSL-1 to elevate CXCL1/CXCL2 levels in cell lysates and conditioned media of UM, respectively. Flow cytometry measured phosphorylated MAPK and activated NF-κB signals in UM, with and without FSL-1 treatment. ELISA analysis tested the impact of various signal inhibitors (NF-κB, p38 MAPK, JNK1/2 and ERK1/2) and TLR2/6 antagonists on FSL-1-induced CXCL1/CXCL2 levels in cultured UM. The effects of neutralizing antibodies to TLR2 on FSL-1-induced mouse uveitis were tested in an experimental animal model. FSL-1 induced the expression of TLR2/6 proteins in cultured UM. FSL-1 significantly elevated the CXCL1 and CXCL2 proteins and mRNA levels in cultured UM time- and dose-dependently. FSL-1 mainly activated NF-κB, JNK, and expression of TLR2. FSL-1-induced expression of CXCL1 and CXCL2 was blocked by NF-κB, JNK, ERK inhibitors and TLR2 antagonists. Intravitreal injection of FSL-1 induced acute non-infectious mouse uveitis, which was significantly reduced in severity by a TLR2 antagonist. These results suggest that UM may play a role in the immune reaction, which targets invading pathogens, especially gram-positive bacteria. On the other hand, an excessive reaction to molecules from gram-positive bacteria may promote an inflammatory state of non-infectious uveitis.

The Toll-Like Receptor 2 Ligand Pam2CSK4 Activates Platelet Nuclear Factor-κB and Bruton's Tyrosine Kinase Signaling to Promote Platelet-Endothelial Cell Interactions.

Circulating platelets establish a variety of immunological programs and orchestrate inflammatory responses at the endothelium. Platelets express the innate immunity family of Toll-like receptors (TLRs). While TLR2/TLR1 ligands are known to activate platelets, the effects of TLR2/TLR6 ligands on platelet function remain unclear. Here, we aim to determine whether the TLR2/TLR6 agonists Pam2CSK4 and FSL-1 activate human platelets. In addition, human umbilical vein endothelial cells (HUVECs) and platelets were co-cultured to analyze the role of platelet TLR2/TLR6 on inflammation and adhesion to endothelial cells. Pam2CSK4, but not FSL-1, induced platelet granule secretion and integrin αIIbß3 activation in a concentration-dependent manner. Moreover, Pam2CSK4 promoted platelet aggregation and increased platelet adhesion to collagen-coated surfaces. Mechanistic studies with blocking antibodies and pharmacologic inhibitors demonstrated that the TLR2/Nuclear factor-κB axis, Bruton's-tyrosine kinase, and a secondary ADP feedback loop are involved in Pam2CSK4-induced platelet functional responses. Interestingly, Pam2CSK4 showed cooperation with immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling to enhance platelet activation. Finally, the presence of platelets increased inflammatory responses in HUVECs treated with Pam2CSK4, and platelets challenged with Pam2CSK4 showed increased adhesion to HUVECs under static and physiologically relevant flow conditions. Herein, we define a functional role for platelet TLR2-mediated signaling, which may represent a druggable target to dampen excessive platelet activation in thrombo-inflammatory diseases.

Design, Synthesis, and Characterization of Novel sn-1 Heterocyclic DAG-Lactones as PKC Activators.

DAG-lactones represent useful templates for the design of potent and selective C1 domain ligands for PKC isozymes. The ester moiety at the sn-1 position, a common feature in this template, is relevant for C1 domain interactions, but it represents a labile group susceptible to endogenous esterases. An interesting challenge involves replacing the ester group of these ligands while still maintaining biological activity. Here, we present the synthesis and functional characterization of novel diacylglycerol-lactones containing heterocyclic ring substituents at the sn-1 position. Our results showed that the new compound 10B12, a DAG-lactone with an isoxazole ring, binds PKCα and PKCε with nanomolar affinity. Remarkably, 10B12 displays preferential selectivity for PKCε translocation in cells and induces a PKCε-dependent reorganization of the actin cytoskeleton into peripheral ruffles in lung cancer cells. We conclude that introducing a stable isoxazole ring as an ester surrogate in DAG-lactones emerges as a novel structural approach to achieve PKC isozyme selectivity.

Early p38 Activation Regulated by MKP-1 Is Determinant for High Levels of IL-10 Expression Through TLR2 Activation.

Toll-like receptors (TLRs) play a crucial role in the recognition of pathogen-derived components as a first line of defense against infections. It has been suggested that depending on the nature of the pathogens, TLRs activation induce a distinct cytokine profile that may contribute to the polarization of the acquired immune response. Here, we investigated the early MAPK signaling activation via TLR4 and TLR2 receptors and its impact in differential cytokine profile by macrophages. We found that TLR2 ligands activated MAPKs p38 and ERK earlier compared to the TLR4 ligand LPS in macrophages. Higher IL-10/IL-12 and IL-10/TNF-α ratios were also observed at later time points in response to TLR2 ligands compared to LPS. The results also indicate an earlier activation of the phosphatase MKP-1 and that MKP-1 KO macrophages show a prolongation in p38 phosphorylation in response to TLR2 stimulation. Furthermore, p38 is critical for IL-10 expression in response to TLR2 ligands, which triggers the macrophage change to a M2 and regulatory phenotype in contrast to the M1 phenotype induced by TLR4 activation. Therefore, the early TLR2-mediated p38 induction contributes for the high IL-10 production, likely as a virulence strategy to suppress host Th1 response against certain types of pathogens.

Human Amnion Epithelial Cells (AECs) Respond to the FSL-1 Lipopeptide by Engaging the NLRP7 Inflammasome.

Context and Objectives: Inflammation is the leading mechanism involved in both physiological and pathological rupture of fetal membranes. Our aim was to obtain a better characterization of the inflammasome-dependent inflammation processes in these tissues, with a particular focus on the nucleotide-binding oligomerization domain (NOD)-like receptor, pyrin domain containing protein 7 (NLRP7) inflammasome. Methods: The presence of NLRP7 inflammasome actors [NLRP7, apoptosis-associated speck-like protein containing a CARD domain (ASC), and caspase-1] was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) in human amnion and choriodecidua at the three trimesters and at term. The protein concentrations were then determined by enzyme-linked immunosorbent assay in term tissues, with or without labor. The presence of Mycoplasma salivarium and Mycoplasma fermentans in human fetal membranes was investigated using a PCR approach. Human amnion epithelial cells (AECs) were treated for 4 or 20 h with fibroblast-stimulating lipopeptide-1 (FSL-1), a M. salivarium-derived ligand. Transcripts and proteins quantity was then measured by RT-quantitative PCR and Western blotting, respectively. NLRP7 and ASC colocalization was confirmed by immunofluorescence. Western blots allowed analysis of pro-caspase-1 and gasdermin D cleavage. Results: NLRP7, ASC, and caspase-1 transcripts were expressed in both sheets of human fetal membranes during all pregnancy stages, but only ASC protein expression was increased with labor. In addition, M. salivarium and M. fermentans were detected for the first time in human fetal membranes. NLRP7 and caspase-1 transcripts, as well as NLRP7, ASC, and pro-caspase-1 protein levels, were increased in FSL-1-treated AECs. The NLRP7 inflammasome assembled around the nucleus, and pro-caspase-1 and gasdermin D were cleaved into their mature forms after FSL-1 stimulation. Conclusion: Two new mycoplasmas, M. salivarium and M. fermentans, were identified in human fetal membranes, and a lipopeptide derived from M. salivarium was found to induce NLRP7 inflammasome formation in AECs.

Liposomal Formulation of a Melphalan Lipophilic Prodrug: Studies of Acute Toxicity, Tolerability, and Antitumor Efficacy.

BACKGROUND: Recently we developed a scalable scheme of synthesis of melphalan ester conjugate with 1,2-dioleoyl-sn-glycerol (MlphDG) and a protocol for the fabrication of its lyophilized liposomal formulation. OBJECTIVE: Herein we compared this new convenient in use formulation of MlphDG with parent drug Alkeran® in rats concerning several toxicological parameters and evaluated its antitumor efficacy in the model of breast cancer in mice. METHOD: Liposomes of approximately 100 nm in diameter, consisting of egg phosphatidylcholine, soybean phosphatidylinositol, and MlphDG, or placebo liposomes without the drug were produced by extrusion and lyophilized. Alkeran® or liposomes recovered by the addition of water were injected into the tail vein of animals. Clinical examination of rats consisted of detailed inspection of the behavior, general status, and hematological parameters. Mice with transplanted breast cancer WNT-1 were subjected to multiple treatments with the drugs; tumor growth inhibition was assessed, together with cellular immunity parameters. RESULTS: Liposomes showed approximately two times lower acute toxicity and better tolerability than Alkeran® in terms of behavioral criteria. The toxic effects of liposomes on hemopoiesis were manifested at higher doses than in the case of Alkeran®, proportionally to the difference in LD50 values. The formulation inhibited tumor growth significantly more effectively than Alkeran®, delaying the start of the exponential growth phase and exhibiting no additional toxic effects toward bone marrow. CONCLUSION: Lower toxicity of the liposomal formulation of MlphDG promises improved quality of life for cancer patients in need of treatment with melphalan. Presumably, the list of indications for melphalan therapy could be extended.

A salivary metabolite signature that reflects gingival host-microbe interactions: instability predicts gingivitis susceptibility.

Several proteins and peptides in saliva were shown to stimulate gingival wound repair, but the role of salivary metabolites in this process remains unexplored. In vitro gingival re-epithelialization kinetics were determined using unstimulated saliva samples from healthy individuals collected during an experimental gingivitis study. Elastic net regression with stability selection identified a specific metabolite signature in a training dataset that was associated with the observed re-epithelialization kinetics and enabled its prediction for all saliva samples obtained in the clinical study. This signature encompassed ten metabolites, including plasmalogens, diacylglycerol and amino acid derivatives, which reflect enhanced host-microbe interactions. This association is in agreement with the positive correlation of the metabolite signature with the individual's gingival bleeding index. Remarkably, intra-individual signature-variation over time was associated with elevated risk for gingivitis development. Unravelling how these metabolites stimulate wound repair could provide novel avenues towards therapeutic approaches in patients with impaired wound healing capacity.

Transcriptome sequencing analysis of porcine MDM response to FSL-1 stimulation.

Mycoplasma infection can cause many diseases in pigs, resulting in great economic losses in pork production. Innate immune responses are thought to play critical roles in the pathogenesis of mycoplasma disease. However, the molecular events involved in immune responses remain to be determined. Hence, the object of this study was to use RNA-Seq to investigate the gene expression profiles of the innate immune response mediated by FSL-1 in pig monocyte-derived macrophages (MDMs). The results revealed that 1442 genes were differentially expressed in the FSL-1 group compared with the control groups, of which 777 genes were upregulated and 665 genes were downregulated. KEGG pathway analysis showed that the upregulated genes were mainly involved in innate immune-related pathways including the TNF signaling pathway, cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, Jak-STAT signaling pathway, chemokine signaling pathway, NOD-like receptor signaling pathway and NF-kappa B signaling pathway. The downregulated genes were only involved in the cGMP-PKG signaling pathway and glycerophospholipid metabolism. Our results showed that FSL-1 stimulation activated the TLR2 signaling pathway and resulted in diverse inflammatory responses. FSL-1 induced the transcription of numerous protein-coding genes involved in a complex network of innate immune-related pathways. We speculate that TNF, IL1B, IL6, NFKB1, NFKBIA, CXCL2, CXCL8, CXCL10, CCL2, CCL4 and CCL5 were the most likely hub genes that play important roles in the above pathways. This study identified the differentially expressed genes and their related signaling pathways, contributing to the comprehensive understanding of the mechanisms underlying host-pathogen interactions during mycoplasma infection and providing a reference model for further studies.

Production, safety, health effects and applications of diacylglycerol functional oil in food systems: a review.

Diacylglycerol (DAG) is a world leading anti-obesity functional cooking oil synthesized via structural modification of conventional fats and oils. DAG exits in three stereoisomers namely sn-1,2-DAG, sn-1,3-DAG, and sn-2,3-DAG. DAG particularly sn-1,3-DAG demonstrated to have the potential in suppressing body fat accumulation and lowering postprandial serum triacylglycerol, cholesterol and glucose level. DAG also showed to improve bone health. This is attributed to DAG structure itself that caused it to absorb and digest via different metabolic pathway than conventional fats and oils. With its purported health benefits, many studies attempt to enzymatically or chemically synthesis DAG through various routes. DAG has also received wide attention as low calorie fat substitute and has been incorporated into various food matrixes. Despite being claimed as healthy cooking oil the safety of DAG still remained uncertain. DAG was banned from sale as it was found to contain probable carcinogen glycidol fatty acid esters. The article aims to provide a comprehensive and latest review of DAG emphasizing on its structure and properties, safety and regulation, process developments, metabolism and beneficial health attributes as well as its applications in the food industry.

Cyclic AMP in human preterm infant blood is associated with increased TLR-mediated production of acute-phase and anti-inflammatory cytokines in vitro.

BACKGROUND: Preterm infants are at high risk of infection and have distinct pathogen recognition responses. Suggested mechanisms include soluble mediators that enhance cellular levels of cAMP. The aim of this study was to assess the relationship between blood cAMP concentrations and TLR-mediated cytokine production in infants during the first month of life. METHODS: Cord and serial peripheral blood samples (days of life 1-28) were obtained from a cohort of very preterm (<30 weeks' gestational age) and term human infants. Whole-blood concentrations of cAMP and FSL-1 and LPS in vitro stimulated cytokine concentrations were measured by ELISA and multiplex bead assay. RESULTS: cAMP concentrations were higher in cord than in peripheral blood, higher in cord blood of female preterm infants, and lower at Days 1 and 7 in infants exposed to chorioamnionitis, even after adjusting for leukocyte counts. TLR2 and TLR4-mediated TNF-α, IL-1ß, IL-6, IL-12p70, and IL-10 production in vitro increased over the first month of life in preterm infants and were positively correlated with leukocyte-adjusted cAMP levels and reduced by exposure to chorioamnionitis. CONCLUSIONS: The ontogeny of blood cAMP concentrations and associations with chorioamnionitis and TLR-mediated production of cytokines suggest that this secondary messenger helps shape distinct neonatal pathogen responses in early life.

1-Palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol ameliorates chemoradiation-induced oral mucositis.

OBJECTIVE: This study was designed to investigate whether necroptosis is involved in the pathogenesis of chemoradiation-induced oral mucositis in a murine model and whether 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) ameliorates this disorder. MATERIALS AND METHODS: A chemoradiation-induced oral mucositis model was established by treating mice with concurrent 5-fluorouracil (100 mg/kg, i.p.) and head and neck X-irradiation (20 Gy). Phosphate-buffered saline or PLAG (100 mg/kg or 250 mg/kg, p.o.) was administered daily. Body weights were recorded daily, and mice were sacrificed on Day 9 for tongue tissue analysis. RESULTS: On Day 9, chemoradiotherapy-treated (ChemoRT) mice had tongue ulcerations and experienced significant weight loss (Day 0:26.18 ± 1.41 g; Day 9:19.44 ± 3.26 g). They also had elevated serum macrophage inhibitory protein 2 (MIP-2) (control: 5.57 ± 3.49 pg/ml; ChemoRT: 130.14 ± 114.54 pg/ml) and interleukin (IL)-6 (control: 198.25 ± 16.91 pg/ml; ChemoRT: 467.25 ± 108.12 pg/ml) levels. ChemoRT-treated mice who received PLAG exhibited no weight loss (Day 0:25.78 ± 1.04 g; Day 9:26.46 ± 1.68 g) and had lower serum MIP-2 (4.42 ± 4.04 pg/ml) and IL-6 (205.75 ± 30.41 pg/ml) levels than ChemoRT-treated mice who did not receive PLAG. Tongue tissues of mice who received PLAG also displayed lower phosphorylation levels of necroptotic signalling proteins. CONCLUSION: 1-Palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol mitigated chemoradiation-induced oral mucositis by modulating necroptosis.

Specific diacylglycerols generated by hepatic lipogenesis stimulate the oncogenic androgen receptor activity in male hepatocytes.

BACKGROUND: Obesity-induced hepatocellular carcinoma (HCC) is more prevalent in males than in females, but the underlying mechanism remains unclear. The influence of hepatic androgen receptor (AR) pathway on the gender difference of HCC has been well documented. Here we investigated the role of hepatic lipogenesis, which is elevated in the livers of obese and nonalcoholic fatty liver disease (NAFLD) patients, in stimulating the AR pathway for the male preference of obesity induced HCC. METHODS: Male C57BL/6J mice were fed a fructose-rich high carbohydrate diet (HCD) to induce hepatic lipogenesis. The effect of hepatic lipogenesis on AR was examined by the expression of hydrodynamically injected AR reporter and the endogenous AR target gene; the mechanism was delineated in hepatoma cell lines and validated in male mice. RESULTS: The hepatic lipogenesis induced by a fructose-rich HCD enhanced the transcriptional activity of hepatic AR in male mice, which did not happen when fed a high fat diet. This AR activation was blocked by sh-RNAs or inhibitors targeting key enzymes in lipogenesis, either acetyl-CoA carboxylase subunit alpha (ACCα), or fatty acid synthase (FASN), in vivo and in vitro. Further mechanistic study identified that specific unsaturated fatty acid, the oleic acid (C18:1 n-9), incorporated DAGs produced by hepatic lipogenesis are the key molecules to enhance the AR activity, through activation of Akt kinase, and this novel mechanism is targeted by metformin. CONCLUSIONS: Our study elucidates a novel mechanism underlying the higher risk of HCC in obese/NAFLD males, through specific DAGs enriched by hepatic lipogenesis to increase the transcriptional activity of hepatic AR, a confirmed risk factor for male HCC.

Differential Regulation of Gene Expression in Lung Cancer Cells by Diacyglycerol-Lactones and a Phorbol Ester Via Selective Activation of Protein Kinase C Isozymes.

Despite our extensive knowledge on the biology of protein kinase C (PKC) and its involvement in disease, limited success has been attained in the generation of PKC isozyme-specific modulators acting via the C1 domain, the binding site for the lipid second messenger diacylglycerol (DAG) and the phorbol ester tumor promoters. Synthetic efforts had recently led to the identification of AJH-836, a DAG-lactone with preferential affinity for novel isozymes (nPKCs) relative to classical PKCs (cPKCs). Here, we compared the ability of AJH-836 and a prototypical phorbol ester (phorbol 12-myristate 13-acetate, PMA) to induce changes in gene expression in a lung cancer model. Gene profiling analysis using RNA-Seq revealed that PMA caused major changes in gene expression, whereas AJH-836 only induced a small subset of genes, thus providing a strong indication for a major involvement of cPKCs in their control of gene expression. MMP1, MMP9, and MMP10 were among the genes most prominently induced by PMA, an effect impaired by RNAi silencing of PKCα, but not PKCδ or PKCε. Comprehensive gene signature analysis and bioinformatics efforts, including functional enrichment and transcription factor binding site analyses of dysregulated genes, identified major differences in pathway activation and transcriptional networks between PMA and DAG-lactones. In addition to providing solid evidence for the differential involvement of individual PKC isozymes in the control of gene expression, our studies emphasize the importance of generating targeted C1 domain ligands capable of differentially regulating PKC isozyme-specific function in cellular models.

SIG1459: A novel phytyl-cysteine derived TLR2 modulator with in vitro and clinical anti-acne activity.

Cutibacterium (formerly Propionibacterium acnes) is a major contributor to the pathogenesis of acne. C. acnes initiates an innate immune response in keratinocytes via recognition and activation of toll-like receptor-2 (TLR2), a key step in comedogenesis. Tetramethyl-hexadecenyl-cysteine-formylprolinate (SIG1459), a novel anti-acne isoprenylcysteine (IPC) small molecule, is shown in this study to have direct antibacterial activity and inhibit TLR2 inflammatory signalling. In vitro antibacterial activity of SIG1459 against C. acnes was established demonstrating minimal inhibitory concentration (MIC = 8.5 µmol\L), minimal bactericidal concentration (MBC = 16.1 µmol\L) and minimal biofilm eradication concentration (MBEC = 12.5 µmol\L). To assess SIG1459's anti-inflammatory activity, human keratinocytes were exposed to C. acnes and different TLR2 ligands (peptidoglycan, FSL-1, Pam3CSK4) that induce pro-inflammatory cytokine IL-8 and IL-1α production. Results demonstrate SIG1459 inhibits TLR2-induced IL-8 release from TLR2/TLR2 (IC50  = 0.086 µmol\L), TLR2/6 (IC50  = 0.209 µmol\L) and IL-1α from TLR2/TLR2 (IC50  = 0.050 µmol\L). To assess the safety and in vivo anti-acne activity of SIG1459, a vehicle controlled clinical study was conducted applying 1% SIG1459 topically (n = 35 subjects) in a head-to-head comparison against 3% BPO (n = 15 subjects). Utilizing the Investigator Global Assessment scale for acne as primary endpoint, results demonstrate 1% SIG1459 significantly outperformed 3% BPO over 8 weeks, resulting in 79% improvement as compared to 56% for BPO. Additionally, 1% SIG1459 was well tolerated. Thus, SIG1459 and phytyl IPC compounds represent a novel anti-acne technology that provides a safe dual modulating benefit by killing C. acnes and reducing the inflammation it triggers via TLR2 signalling.

Diacylglycerol in Cationic Nanoparticles Stimulates Oxidative Stress-Mediated Death of Cancer Cells.

Previous reports have suggested that cargo-free cationic nanoparticles (cNP) consisting of cationic monovalent lipids, such as 1,2-oleoyl-3-trimethylammonium-propane (DOTAP), induce reactive oxygen species (ROS) generation and toxicity in cells. In addition, cNP containing six lysine residues (6K) and cargo (6K-cNP) exerted synergistic effects on ROS production and cell death in cancer cells. In this study, we investigated the effect of diacylglycerol (DAG) derived from egg phosphatidylcholine in nanoparticles (NP) on ROS-mediated cellular toxicity. When DAG was incorporated into cNP (D-cNP) or 6K-cNP (6K-D-cNP) up to 7.8 mol% at the expense of DOTAP, and treated with cells, ROS generation in cancer cells increased further in a DAG concentration-dependent manner compared with those of both cNP without DAG. Concomitantly, cancer cell viability was more decreased upon the treatment with DAG-containing cNP. Moreover, D-cNP or 6K-D-cNP exhibited enhanced uptake into cells under endocytosis-inhibited conditions. Taken together, these results suggested that the presence of DAG in NP stimulated the interaction of NP with cancer cells and the resulting ROS-mediated cytotoxicity.

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) reduces hepatic injury in concanavalin A-treated mice.

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG), a chemically synthesized monoacetyldiaglyceride, is one of the constituents in Sika deer antlers and has been known traditionally as having immunomodulatory effects. However, the mechanism by which PLAG controls neutrophil migration, which evokes liver injury in the hepatitis animal model, remains largely unknown. This study was designed to evaluate the immunomodulatory effects of PLAG on cytokine secretion and neutrophil migration in vivo and in vitro. Concanavalin A (Con A) induced leukocyte infiltration in the liver and increased plasma cytokine levels. Pretreatment with PLAG reduced the levels of interleukin (IL)-4, IL-6, IL-10, and CXCL2, but maintained interferon (IFN)-γ levels and modulated neutrophil recruitment toward the liver. Furthermore, the mRNA and protein levels of IL-4 and CXCL2 in liver tissue were also decreased in the Con A-treated mice. Liver histology analyses showed that PLAG reduced Con A-induced hepatic necrosis, which was accompanied by leukocyte infiltration. The in vitro studies revealed that PLAG reduced IL-4 secretion in Con A stimulated T cell and blocked signal transducer and activator of transcription 6 (STAT6) Con A induced hepatocyte. PLAG attenuated IL-4 induced activation of atypical protein kinase C (PKC)/STAT6 in hepatocytes and inhibited neutrophil migration toward the liver tissue through suppression of IL-8/vascular cell adhesion molecule (VCAM) expression. These results suggest that PLAG could mitigate excess neutrophil migration into liver tissue and potentially have a therapeutic effect on immune-mediated liver injury.