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Journal of Controlled Release :... Jul 2023Glioblastoma multiforme (GBM) is the deadliest brain tumor with a poor prognosis and limited therapeutic options. Temozolomide (TMZ) is the first-line chemotherapeutic...
Glioblastoma multiforme (GBM) is the deadliest brain tumor with a poor prognosis and limited therapeutic options. Temozolomide (TMZ) is the first-line chemotherapeutic agent used for the treatment of GBM; however, it suffers from several limitations, including short half-life, rapid metabolism, <1% brain bioavailability, methyl guanine methyl transferase (MGMT) based chemoresistance, and hematological toxicities. Several approaches have been adopted to overcome these limitations, particularly by using nanotechnology-based systems, but its physicochemical properties make TMZ challenging to load into these nanocarriers. In the current research, we conjugated TMZ with different fatty acids, i.e., linoleic acid (LA), oleic acid (OA), and palmitic acid (PA), to obtain TMZ-fatty acid conjugates, which are comparatively hydrophobic, less prone to degradation and potent. These conjugates were thoroughly characterized using H NMR spectroscopy, high-resolution mass spectrometry (HR-MS), and reverse phase-high performance liquid chromatography (RP-HPLC). The synthesized conjugates, namely Temozolomide-oleic acid (TOA,6R), Temozolomide-linoleic acid (TLA, 6R), and Temozolomide-palmitic acid (TPA, 6R), showed an IC of 101.4, 67.97, and 672.04 μM, respectively in C cells and 428.257, 366.43 and 413.69 μM, respectively in U87-MG cells. On the other hand, the free TMZ showed an IC of >1000 μM and 564.23 μM in C and U87-MG, respectively. Further, the in vivo efficacy of the TMZ-fatty acid conjugates was evaluated in the C-induced orthotropic rat glioblastoma model, wherein the TMZ-fatty acid conjugate showed improved survival rate (1.6 folds) and overall health of the animals. Collectively, the conjugation of fatty acids with TMZ improves its anticancer potential against glioblastoma multiforme (GBM).
Topics: Rats; Animals; Temozolomide; Glioblastoma; Antineoplastic Agents, Alkylating; Fatty Acids; Cell Line, Tumor; Brain Neoplasms; Linoleic Acids; Palmitic Acids; Oleic Acids; Drug Resistance, Neoplasm; Xenograft Model Antitumor Assays
PubMed: 37182806
DOI: 10.1016/j.jconrel.2023.05.012 -
Talanta Jul 2023The high incidence and mortality of colorectal cancer (CRC) and the lack of adequate diagnostic molecules have led to poor treatment outcomes for colorectal cancer,...
The high incidence and mortality of colorectal cancer (CRC) and the lack of adequate diagnostic molecules have led to poor treatment outcomes for colorectal cancer, making it particularly important to develop methods to obtain molecular with significant diagnostic effects. Here, we proposed a whole and part study strategy (early-stage colorectal cancer as "part" and colorectal cancer as "whole") to identify specific and co-pathways of change in early-stage and colorectal cancers and to discover the determinants of colorectal cancer development. Metabolite biomarkers discovered in plasma may not necessarily reflect the pathological status of tumor tissue. To explore the determinant biomarkers associated with plasma and tumor tissue in the CRC progression, multi-omics were performed on three phases of biomarker discovery studies (discovery, identification and validation) including 128 plasma metabolomes and 84 tissue transcriptomes. Importantly, we observe that the metabolic levels of oleic acid and FA (18:2) in patients with colorectal cancer were much higher than in healthy people. Finally, biofunctional verification confirmed that oleic acid and FA (18:2) can promote the growth of colorectal cancer tumor cells and be used as plasma biomarkers for early-stage colorectal cancer. We propose a novel research strategy to discover co-pathways and important biomarkers that may be targeted for a potential role in early colorectal cancer, and our work provides a promising tool for the clinical diagnosis of colorectal cancer.
Topics: Colorectal Neoplasms; Multiomics; Humans; Transcriptome; Oleic Acid; Lipid Metabolism; Biomarkers, Tumor; Cell Line, Tumor
PubMed: 37058941
DOI: 10.1016/j.talanta.2023.124543 -
Gastroenterology Oct 2023Although transient bacteremia is common during dental and endoscopic procedures, infections developing during sterile diseases like acute pancreatitis (AP) can have...
BACKGROUND & AIMS
Although transient bacteremia is common during dental and endoscopic procedures, infections developing during sterile diseases like acute pancreatitis (AP) can have grave consequences. We examined how impaired bacterial clearance may cause this transition.
METHODS
Blood samples from patients with AP, normal controls, and rodents with pancreatitis or those administered different nonesterified fatty acids (NEFAs) were analyzed for albumin-unbound NEFAs, microbiome, and inflammatory cell injury. Macrophage uptake of unbound NEFAs using a novel coumarin tracer were done and the downstream effects-NEFA-membrane phospholipid (phosphatidylcholine) interactions-were studied on isothermal titration calorimetry.
RESULTS
Patients with infected AP had higher circulating unsaturated NEFAs; unbound NEFAs, including linoleic acid (LA) and oleic acid (OA); higher bacterial 16S DNA; mitochondrial DNA; altered β-diversity; enrichment in Pseudomonadales; and increased annexin V-positive myeloid (CD14) and CD3-positive T cells on admission. These, and increased circulating dead inflammatory cells, were also noted in rodents with unbound, unsaturated NEFAs. Isothermal titration calorimetry showed progressively stronger unbound LA interactions with aqueous media, phosphatidylcholine, cardiolipin, and albumin. Unbound NEFAs were taken into protein-free membranes, cells, and mitochondria, inducing voltage-dependent anion channel oligomerization, reducing ATP, and impairing phagocytosis. These were reversed by albumin. In vivo, unbound LA and OA increased bacterial loads and impaired phagocytosis, causing infection. LA and OA were more potent for these amphipathic interactions than the hydrophobic palmitic acid.
CONCLUSIONS
Release of stored LA and OA can increase their circulating unbound levels and cause amphipathic liponecrosis of immune cells via uptake by membrane phospholipids. This impairs bacterial clearance and causes infection during sterile inflammation.
Topics: Humans; Acute Disease; Pancreatitis; Fatty Acids, Nonesterified; Oleic Acid; Inflammation; Albumins; Phosphatidylcholines
PubMed: 37263302
DOI: 10.1053/j.gastro.2023.05.034 -
Hepatology (Baltimore, Md.) Jul 2024Lymph node metastasis is a significant risk factor for patients with cholangiocarcinoma, but the mechanisms underlying cholangiocarcinoma colonization in the lymph node...
BACKGROUND AND AIMS
Lymph node metastasis is a significant risk factor for patients with cholangiocarcinoma, but the mechanisms underlying cholangiocarcinoma colonization in the lymph node microenvironment remain unclear. We aimed to determine whether metabolic reprogramming fueled the adaptation and remodeling of cholangiocarcinoma cells to the lymph node microenvironment.
APPROACH AND RESULTS
Here, we applied single-cell RNA sequencing of primary tumor lesions and paired lymph node metastases from patients with cholangiocarcinoma and revealed significantly reduced intertumor heterogeneity and syntropic lipid metabolic reprogramming of cholangiocarcinoma after metastasis to lymph nodes, which was verified by pan-cancer single-cell RNA sequencing analysis, highlighting the essential role of lipid metabolism in tumor colonization in lymph nodes. Metabolomics and in vivo CRISPR/Cas9 screening identified PPARγ as a crucial regulator in fueling cholangiocarcinoma colonization in lymph nodes through the oleic acid-PPARγ-fatty acid-binding protein 4 positive feedback loop by upregulating fatty acid uptake and oxidation. Patient-derived organoids and animal models have demonstrated that blocking this loop impairs cholangiocarcinoma proliferation and colonization in the lymph node microenvironment and is superior to systemic inhibition of fatty acid oxidation. PPARγ-regulated fatty acid metabolic reprogramming in cholangiocarcinoma also contributes to the immune-suppressive niche in lymph node metastases by producing kynurenine and was found to be associated with tumor relapse, immune-suppressive lymph node microenvironment, and poor immune checkpoint blockade response.
CONCLUSIONS
Our results reveal the role of the oleic acid-PPARγ-fatty acid-binding protein 4 loop in fueling cholangiocarcinoma colonization in lymph nodes and demonstrate that PPARγ-regulated lipid metabolic reprogramming is a promising therapeutic target for relieving cholangiocarcinoma lymph node metastasis burden and reducing further progression.
Topics: Cholangiocarcinoma; PPAR gamma; Humans; Bile Duct Neoplasms; Lymphatic Metastasis; Tumor Microenvironment; Animals; Fatty Acid-Binding Proteins; Mice; Oleic Acid; Lymph Nodes; Lipid Metabolism
PubMed: 38377465
DOI: 10.1097/HEP.0000000000000784 -
Molecules (Basel, Switzerland) Sep 2023Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from...
Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from dietary intake, plasma free fatty acid (FFA) uptake, or hepatic de novo lipogenesis (DNL). Currently, cellular and animal models of hepatocellular steatosis are widely used to study the pathogenesis of NAFLD and to investigate therapeutic agents. However, whether there are differences between the in vivo and in vitro models of the mechanisms that cause lipid accumulation has not been reported. We used OA/PA-induced NCTC 1469 cells and high-fat-diet-fed C57BL/6J mice to simulate a hepatocyte steatosis model of NAFLD and to detect indicators related to FFA uptake and DNL. In addition, when serological indicators were analysed in the mouse model, it was found that serum FASN levels decreased. The results revealed that, in the cellular model, indicators related to DNL were decreased, FASN enzyme activity was unchanged, and indicators related to FFA uptake were increased, including the high expression of CD36; while, in the animal model, indicators related to both FFA uptake and de novo synthesis were increased, including the high expression of CD36 and the increased protein levels of FASN with enhanced enzyme activity. In addition, after an analysis of the serological indicators in the mouse model, it was found that the serum levels of FASN were reduced. In conclusion, the OA/PA-induced cellular model can be used to study the mechanism of FFA uptake, whereas the high-fat-diet-induced mouse model can be used to study the mechanism of FFA uptake and DNL. Combined treatment with CD36 and FASN may be more effective against NAFLD. FASN in the serum can be used as one of the indicators for the clinical diagnosis of NAFLD.
Topics: Mice; Animals; Mice, Inbred C57BL; Oleic Acid; Palmitic Acid; Non-alcoholic Fatty Liver Disease; Diet, High-Fat; Hepatocytes; Disease Models, Animal; CD36 Antigens; Fatty Acids, Nonesterified
PubMed: 37764494
DOI: 10.3390/molecules28186714 -
Phytomedicine : International Journal... Oct 2023Nonalcoholic fatty liver disease (NAFLD) is becoming a global epidemic without effective treatment currently available. NAFLD is characterized by an increase in hepatic...
BACKGROUND
Nonalcoholic fatty liver disease (NAFLD) is becoming a global epidemic without effective treatment currently available. NAFLD is characterized by an increase in hepatic de novo lipogenesis (DNL) and inadequate compensatory enhancement in fatty acid oxidation (FAO), which disturbs lipid homeostasis. In NAFLD, lipid metabolism relies heavily on metabolic reprogramming. Moreover, lipid metabolism plays an essential role in switching between lipogenesis and FAO, which is beneficial for the anti-NAFLD therapy. Our recent study demonstrated that the phytochemical tetrahydropalmatine (THP) has positive efficacy in hepatocellular carcinoma (HCC). However, it remains unclear whether the therapeutic benefits of THP are primarily due to delaying the progression of hepatic steatosis to HCC.
PURPOSE
This work aimed to systemically evaluate the pharmacological functions and underlying mechanisms of THP in NAFLD using both in vitro and in vivo models.
METHODS
NAFLD models were established using high-fat diet (HFD)-fed mice in vivo and palmitic acid- and oleic acid-challenged hepatocytes in vitro. Metabonomics analysis concomitant with biochemical indices and computational biology assays were performed comprehensively to reveal the key link between the treatment of NAFLD and the AMPK-SREBP-1c-Sirt1 signaling axis.
RESULTS
Hepatic metabolomics analysis revealed that THP altered lipid metabolism by enhancing FAO and inhibiting glycolysis, tricarboxylic acid cycle, and urea cycle in HFD-fed mice. Analysis of gene expression showed that THP profoundly suppressed hepatic DNL and promoted FAO. THP supplementation not only significantly decreased body/liver weight gain and serum indices but also ameliorated hepatic steatosis. Simultaneously, impaired lipotoxicity was observed in vivo and in vitro after THP supplementation, protecting against steatosis-driven injury. Metabolic phenotype assays showed that THP promoted switching from glycolysis inhibition to FAO enhancement in steatotic cells, resulting in reprogramming lipid metabolism. Mechanistically, THP accelerated lipid oxidation by activating AMPK-SREBP-1c-Sirt1 axis signaling. Applying molecular docking combined with surface plasmon resonance and cellular thermal shift assay target engagement, as well as siRNA assays, AMPKα was confirmed as a direct molecular target of THP.
CONCLUSION
In summary, THP ameliorates hepatic steatosis in NAFLD by switching lipid metabolism via the AMPK-SREBP-1c-Sirt1 pathway. This work provides an attractive phytochemical component for therapy against hepatic steatosis in NAFLD.
Topics: Animals; Mice; Non-alcoholic Fatty Liver Disease; Lipid Metabolism; Sterol Regulatory Element Binding Protein 1; AMP-Activated Protein Kinases; Carcinoma, Hepatocellular; Sirtuin 1; Molecular Docking Simulation; Liver Neoplasms; Liver; Oleic Acid; Diet, High-Fat; Mice, Inbred C57BL
PubMed: 37562090
DOI: 10.1016/j.phymed.2023.155005 -
International Journal of Molecular... Sep 2023Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of lipids within hepatocytes, which compromises liver functionality following...
Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of lipids within hepatocytes, which compromises liver functionality following mitochondrial dysfunction and increased production of reactive oxygen species (ROS). Lipoic acid is one of the prosthetic groups of the pyruvate dehydrogenase complex also known for its ability to confer protection from oxidative damage because of its antioxidant properties. In this study, we aimed to investigate the effects of lipoic acid on lipotoxicity and mitochondrial dynamics in an in vitro model of liver steatosis. HepG2 cells were treated with palmitic acid and oleic acid (1:2) to induce steatosis, without and with 1 and 5 µM lipoic acid. Following treatments, cell proliferation and lipid droplets accumulation were evaluated. Mitochondrial functions were assessed through the evaluation of membrane potential, MitoTracker Red staining, expression of genes of the mitochondrial quality control, and analysis of energy metabolism by HPLC and Seahorse. We showed that lipoic acid treatment restored membrane potential to values comparable to control cells, as well as protected cells from mitochondrial fragmentation following PA:OA treatment. Furthermore, our data showed that lipoic acid was able to determine an increase in the expression of mitochondrial fusion genes and a decrease in mitochondrial fission genes, as well as to restore the bioenergetics of cells after treatment with palmitic acid and oleic acid. In conclusion, our data suggest that lipoic acid reduces lipotoxicity and improves mitochondrial functions in an in vitro model of steatosis, thus providing a potentially valuable pharmacological tool for NAFLD treatment.
Topics: Humans; Thioctic Acid; Non-alcoholic Fatty Liver Disease; Palmitic Acid; Oleic Acid; Mitochondria; Hepatocytes; Oxidative Stress; Energy Metabolism; Liver
PubMed: 37833939
DOI: 10.3390/ijms241914491 -
Journal of Oleo Science 2024Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid... (Comparative Study)
Comparative Study
Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid hydroperoxides as primary oxidation products. However, the catabolic rates of unsaturated fatty acid hydroperoxides in the human body remain unknown. In this study, ethyl esters of C-labeled linoleic acid (*C18:2-EE) and oleic acid (*C18:1-EE) and their hydroperoxides (*C18:2-EE-OOH and *C18:1-EE-OOH, respectively) prepared by the photo-oxidation of *C18:2-EE and *C18:1-EE, respectively, were administered to mice and their catabolic rates were determined by measuring the expired CO levels. *C18:2-EE-OOH and *C18:1-EE-OOH were β-oxidized faster than *C18:2-EE and *C18:1-EE, respectively. Notably, rapid β-oxidation of *C18:2-EE-OOH and *C18:1-EE-OOH was similar to that of medium-chain fatty acids, such as octanoic acid. Then, degradation products of C18:2-EE-OOH and C18:1-EE-OOH were analyzed under gastric conditions by gas chromatography/mass spectrometry. Major decomposition products of C18:2-EE-OOH and C18:1-EE-OOH were medium-chain compounds, such as octanoic acid ethyl ester, 9-oxo-nonanoic acid ethyl ester, and 10-oxo-8-decenoic acid ethyl esters, indicating that C18:2-EE-OOH and C18:1-EE-OOH isomers formed during photo-oxidation were decomposed under acidic conditions. These findings support previous reports that dietary lipid hydroperoxides are not absorbed into the intestine as lipid hydroperoxides but as degradation products. This is the first study to suggest that dietary lipid hydroperoxides decompose during gastric digestion to form medium-chain compounds that are directly absorbed into the liver via the portal vein and rapidly catabolized via β-oxidation.
Topics: Animals; Oxidation-Reduction; Oleic Acid; Linoleic Acid; Carbon Dioxide; Carbon Isotopes; Mice; Male; Hydrogen Peroxide
PubMed: 38825538
DOI: 10.5650/jos.ess23236 -
Experimental Eye Research Apr 2024The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional...
The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional disorder, as it is a potent stimulator of acne-related lipogenesis and inflammation in sebaceous gland. Therefore, we investigate whether OA induces lipogenesis and inflammasome activation in organotypic cultured mouse MG and human meibomian gland epithelial cells (HMGECs). Organotypic cultured mouse MG and HMGECs were exposed to OA or combinations with specific AMPK agonists 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Lipogenic status, ductal keratinization, squamous metaplasia, NLRP3/ASC/Caspase-1 inflammasome activation, proinflammatory cytokine IL-1β production, and AMPK pathway phosphorylation in MG were subsequently examined by lipid staining, immunofluorescence staining, immunohistochemical staining, ELISA assay, and Western blot analyses. We found that OA significantly induced lipid accumulation, ductal keratinization, and squamous metaplasia in organotypic cultured MG, as evidenced by increased lipids deposition within acini and duct, upregulated expression of lipogenic proteins (SREBP-1 and HMGCR), and elevation of K10/Sprr1b. Additionally, OA induced NLRP3/ASC/Caspase-1 inflammasome activation, cleavage of Caspase-1, and production of downstream proinflammatory cytokine IL-1β. The findings of lipogenesis and NLRP3-related proinflammatory response in OA-stimulated HMGECs were consistent with those in organotypic cultured MG. OA exposure downregulated phospho-AMPK in two models, while AICAR treatment alleviated lipogenesis by improving AMPK/ACC phosphorylation and SREBP-1/HMGCR expression. Furthermore, AMPK amelioration inhibited activation of the NLRP3/ASC/Caspase-1 axis and secretion of IL-1β, thereby relieving the OA-induced proinflammatory response. These results demonstrated that OA induced lipogenic disorder and NLRP3 inflammasome activation in organotypic cultured mouse MG and HMGECs by suppressing the AMPK signaling pathway, indicating OA may play an etiological role in MGD.
Topics: Humans; Mice; Animals; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Sterol Regulatory Element Binding Protein 1; Oleic Acid; Meibomian Glands; AMP-Activated Protein Kinases; Lipogenesis; Epithelial Cells; Caspase 1; Cytokines; Metaplasia; Carcinoma, Squamous Cell; Interleukin-1beta
PubMed: 38453039
DOI: 10.1016/j.exer.2024.109851 -
BioRxiv : the Preprint Server For... Oct 2023Lipogenesis is a vital but often dysregulated metabolic pathway. We report super-resolution multiplexed vibrational imaging of lipogenesis rates and pathways using...
Lipogenesis is a vital but often dysregulated metabolic pathway. We report super-resolution multiplexed vibrational imaging of lipogenesis rates and pathways using isotopically labelled oleic acid and glucose as probes in live adipocytes and hepatocytes. These findings suggest oleic acid inhibits lipogenesis (DNL), but not total lipogenesis, in hepatocytes. No significant effect is seen in adipocytes. These differential effects may be due to alternate regulation of DNL between cell types and could help explain the complicated role oleic acid plays in metabolism.
PubMed: 37873279
DOI: 10.1101/2023.10.04.560581