Disturbances In Fatty Acid Metabolism Research Articles

Potential role of lipophagy impairment for anticancer effects of glycolysis-suppressed pancreatic ductal adenocarcinoma cells

Although increased aerobic glycolysis is common in various cancers, pancreatic ductal adenocarcinoma (PDAC) cells can survive a state of glycolysis suppression. We aimed to identify potential therapeutic targets in glycolysis-suppressed PDAC cells. By screening anticancer metabolic compounds, we identified SP-2509, an inhibitor of lysine-specific histone demethylase 1A (LSD1), which dramatically decreased the growth of PDAC PANC-1 cells and showed an anti-tumoral effect in tumor-bearing mice. The growth of glycolysis-suppressed PANC-1 cells was also inhibited by another LSD1 inhibitor, OG-L002. Similarly, the other two PDAC cells (PK-1 and KLM-1) with suppressed glycolysis exhibited anticancer effects against SP-2509. However, the anticancer effects on PDAC cells were unrelated to LSD1. To investigate how PDAC cells survive in a glycolysis-suppressed condition, we conducted proteomic analyses. These results combined with our previous findings suggested that glucose-starvation causes PDAC cells to enhance mitochondrial oxidative phosphorylation. In particular, mitochondrial fatty acid metabolism was identified as a key factor contributing to the survival of PDAC cells under glycolysis suppression. We further demonstrated that SP-2509 and OG-L002 disturbed fatty acid metabolism and induced lipid droplet accumulation through the impairment of lipophagy, but not bulk autophagy. These findings indicate a significant potential association of lipophagy and anticancer effects in glycolysis-suppressed PDAC cells, offering ideas for new therapeutic strategies for PDAC by dual inhibition of glycolysis and fatty acids metabolism.

Dexmedetomidine post-treatment exacerbates metabolic disturbances in septic cardiomyopathy via α2A-adrenoceptor

Cardiomyopathy is a common complication and significantly increases the risk of death in septic patients. Our previous study demonstrated that post-treatment with dexmedetomidine (DEX) aggravates septic cardiomyopathy. However, the mechanisms for the side effect of DEX post-treatment on septic cardiomyopathy are not well-defined. Here we employed a cecal ligation and puncture (CLP) model and α2A-adrenoceptor deficient (Adra2a-/-) mice to observe the effects of DEX post-treatment on myocardial metabolic disturbances in sepsis. CLP mice displayed significant cardiac dysfunction, altered mitochondrial dynamics, reduced cardiac lipid and glucose uptake, impaired fatty acid and glucose oxidation, enhanced glycolysis and decreased ATP production in the myocardium, almost all of which were dramatically enhanced by DEX post-treatment in septic mice. In Adra2a-/- mice, DEX post-treatment did not affect cardiac dysfunction and metabolic disruptions in CLP-induced sepsis. Additionally, Adra2a-/- mice exhibited impaired cardiac function, damaged myocardial mitochondrial structures, and disturbed fatty acid metabolism and glucose oxidation. In sum, DEX post-treatment exacerbates metabolic disturbances in septic cardiomyopathy in a α2A-adrenoceptor dependent manner.

Fumonisin B Series Mycotoxins' Dose Dependent Effects on the Porcine Hepatic and Pulmonary Phospholipidome.

Male weaned piglets n = 6/group were fed Fumonisin B1+2+3 (FBs) mycotoxins at 0, 15, or 30 mg/kg diet for 3 weeks to assess the fatty acid (FA) composition of membrane lipid classes, lipid peroxidation, and histomorphological changes in the liver and lung. Growth performance and lipid peroxidation were unaltered, but histomorphological lesion scores increased in the liver. Linear dose-response was detected in liver phosphatidylcholines for C16:1n7, C18:1n9, and total monounsaturation and in lungs for C22:6n3, total n-3 and n-3:n-6, in pulmonary phosphatidylserines C20:0 and C24:0. Alterations associated with the highest FBs dose were detected in sphingomyelins (liver: total saturation ↓, total monounsaturation ↑), phosphatidylcholines (liver: total n-6 ↓, n-6:n-3 ↑; in lungs: total monounsaturation ↑, total polyunsaturation ↑), phosphatidylethanolamines (liver: total n-3 ↓; in lungs: total monounsaturation ↑ and n-6:n-3 ↑), phosphatidylserines (liver: n-6:n-3 ↑; in lungs: total saturation ↓, total polyunsatuartion ↑, and total n-6 and its ratio to n-3 ↑), and phosphatidylinositol (n-6:n-3 ↑; lungs: C22:1n9 ↑, C22:6n3 ↓, total saturation ↓, total monounsaturaion ↑). In conclusion, FBs exposures neither impaired growth nor induced substantial lipid peroxidation, but hepatotoxicity was proven with histopathological alterations at the applied exposure period and doses. FA results imply an enzymatic disturbance in FA metabolism, agreeing with earlier findings in rats.

Signatures of Mitochondrial Dysfunction and Impaired Fatty Acid Metabolism in Plasma of Patients with Post-Acute Sequelae of COVID-19 (PASC).

Exercise intolerance is a major manifestation of post-acute sequelae of severe acute respiratory syndrome coronavirus infection (PASC, or "long-COVID"). Exercise intolerance in PASC is associated with higher arterial blood lactate accumulation and lower fatty acid oxidation rates during graded exercise tests to volitional exertion, suggesting altered metabolism and mitochondrial dysfunction. It remains unclear whether the profound disturbances in metabolism that have been identified in plasma from patients suffering from acute coronavirus disease 2019 (COVID-19) are also present in PASC. To bridge this gap, individuals with a history of previous acute COVID-19 infection that did not require hospitalization were enrolled at National Jewish Health (Denver, CO, USA) and were grouped into those that developed PASC (n = 29) and those that fully recovered (n = 16). Plasma samples from the two groups were analyzed via mass spectrometry-based untargeted metabolomics and compared against plasma metabolic profiles of healthy control individuals (n = 30). Observational demographic and clinical data were retrospectively abstracted from the medical record. Compared to plasma of healthy controls or individuals who recovered from COVID-19, PASC plasma exhibited significantly higher free- and carnitine-conjugated mono-, poly-, and highly unsaturated fatty acids, accompanied by markedly lower levels of mono-, di- and tricarboxylates (pyruvate, lactate, citrate, succinate, and malate), polyamines (spermine) and taurine. Plasma from individuals who fully recovered from COVID-19 exhibited an intermediary metabolic phenotype, with milder disturbances in fatty acid metabolism and higher levels of spermine and taurine. Of note, depletion of tryptophan-a hallmark of disease severity in COVID-19-is not normalized in PASC patients, despite normalization of kynurenine levels-a tryptophan metabolite that predicts mortality in hospitalized COVID-19 patients. In conclusion, PASC plasma metabolites are indicative of altered fatty acid metabolism and dysfunctional mitochondria-dependent lipid catabolism. These metabolic profiles obtained at rest are consistent with previously reported mitochondrial dysfunction during exercise, and may pave the way for therapeutic intervention focused on restoring mitochondrial fat-burning capacity.

Disturbance of Fatty Acid Metabolism Promoted Vascular Endothelial Cell Senescence via Acetyl-CoA-Induced Protein Acetylation Modification.

Endothelial cell senescence is the main risk factor contributing to vascular dysfunction and the progression of aging-related cardiovascular diseases. However, the relationship between endothelial cell metabolism and endothelial senescence remains unclear. The present study provides novel insight into fatty acid metabolism in the regulation of endothelial senescence. In the replicative senescence model and H2O2-induced premature senescence model of primary cultured human umbilical vein endothelial cells (HUVECs), fatty acid oxidation (FAO) was suppressed and fatty acid profile was disturbed, accompanied by downregulation of proteins associated with fatty acid uptake and mitochondrial entry, in particular the FAO rate-limiting enzyme carnitine palmitoyl transferase 1A (CPT1A). Impairment of fatty acid metabolism by silencing CPT1A or CPT1A inhibitor etomoxir facilitated the development of endothelial senescence, as implied by the increase of p53, p21, and senescence-associated β-galactosidase, as well as the decrease of EdU-positive proliferating cells. In the contrary, rescue of FAO by overexpression of CPT1A or supplement of short chain fatty acids (SCFAs) acetate and propionate ameliorated endothelial senescence. In vivo, treatment of acetate for 4 weeks lowered the blood pressure and alleviated the senescence-related phenotypes in aortas of Ang II-infused mice. Mechanistically, fatty acid metabolism regulates endothelial senescence via acetyl-coenzyme A (acetyl-CoA), as implied by the observations that suppression of acetyl-CoA production using the inhibitor of ATP citrate lyase NDI-091143 accelerated senescence of HUVECs and that supplementation of acetyl-CoA prevented H2O2-induced endothelial senescence. Deficiency of acetyl-CoA resulted in alteration of acetylated protein profiles which are associated with cell metabolism and cell cycle. These findings thus suggest that improvement of fatty acid metabolism might ameliorate endothelial senescence-associated cardiovascular diseases.

P612: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL)-DERIVED T-CELLS HAVE DISTURBED FATTY ACID METABOLISM, POSSIBLY CONTRIBUTING TO T-CELL DYSFUNCTION

Background: T-cells from CLL patients are dysfunctional and display reduced activation, proliferation and cytotoxicity upon in-vitro activation. Whilst the role of glucose metabolism in activated T cells is extensively studied, the contribution of other energy sources is less clear. Fatty acid (FA) and lipid uptake in T cells involves the scavenger membrane transporter CD36. CD36-mediated lipid transport has been identified to (metabolically) modulate intratumoral T cells (both Treg and cytotoxic CD8+ T cells). However, lipid metabolism and a potential role for CD36 has not been studied in the context of T cell dysfunction in CLL Aims: To examine the role of FA metabolism and the fatty acid transporter CD36 in acquired T-cell dysfunction in CLL. Methods: Untreated CLL patients with a white blood cell count (WBC) greater than 20×109 cells/L and, as control, age-matched healthy donors (HD) were studied. T cells were analyzed by flow cytometry, confocal microscopy or extracellular flux analysis (Seahorse), either directly after thawing or after a 2 day culture with or without αCD3/αCD28 antibodies. Results: Analysis of CD36+ vs CD36- CD4 and CD8 T-cells from HD revealed that CD36+ cells had higher long-chain fatty acid (LCFA) and glucose uptake, and higher expression of the glucose transporter GLUT-1 and the rate-limiting mitochondrial FA transporter CPT1α (Fig. 1A). The cells expressing CD36 were also more likely to increase their CD25 expression and mitochondrial mass upon stimulation, indicating a metabolic and functional advantage potentially conferred by the surface expression of CD36. The absolute amount and percentage of T cells (CD4 and CD8) expressing FA transporter CD36 was lower in CLL T-cells as compared to HD (Fig. 1B). The levels of LCFA uptake and expression of CPT1α were comparable, indicating that the lower amount of CD36 might successfully cater to the FA demands of resting CLL T cells(Fig. 1C). However, while stimulation of HD T-cells markedly upregulated CD36 abundance, LCFA uptake and CPT1α, concomitantly with the activation marker CD25, CLL-derived T-cells failed to mount a similar response (Fig. 1D). This lack of induction of CD36 expression was also observed in CLL-derived T cells that increased CD25, which implies that this response is independent of T-cell activation. The transcription factors peroxisome proliferator-activated receptors (PPAR) α and γ are important regulators of FA metabolism. We observed reduced expression of these transcription factors in resting CLL T cells. However, distinct from CD36, CLL T cells were indistinguishable from HD T-cells in their ability to increase levels of both PPARα and PPARγ upon stimulation, indicating that alternative mechanisms might be implicated in the regulation of CD36 and FA metabolism in CLL T cells. Image:Summary/Conclusion: Collectively, our results show that disturbances in FA metabolism are present on multiple levels in CLL T cells and that lack of LCFA uptake into CLL T-cells could represent a limiting step in FA metabolism. We also highlight CD36+ cells as a metabolically distinct T-cell subtype that is largely absent in CLL T-cells, independently of their activation status. We are currently investigating strategies to increase CD36 expression and FA metabolism in general in CLL T cells, which could ameliorate CLL T cell dysfunction and provide targets to improve autologous T cell therapies.

Combined Transcriptome and Proteome Analysis to Elucidate Salt Tolerance Strategies of the Halophyte Panicum antidotale Retz.

Panicum antidotale, a C4 monocot, has the potential to reclaim saline and drylands and to be utilized as fodder and forage. Its adaptability to survive saline stress has been proven with eco-physiological and biochemical studies. However, little is known about its molecular mechanisms of salt tolerance. In this study, an integrated transcriptome and proteome analysis approach, based on RNA sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), was used to identify the said mechanisms. Plants were treated with control (0 mM), low (100 mM), and high (300 mM) sodium chloride (NaCl) treatments to distinguish beneficial and toxic pathways influencing plant biomass. The results indicated differential expression of 3,179 (1,126 upregulated/2,053 downregulated) and 2,172 (898 upregulated/1,274 downregulated) genes (DEGs), and 514 (269 upregulated/245 downregulated) and 836 (494 upregulated/392 downregulated) proteins (DEPs) at 100 and 300 mM NaCl, respectively. Among these, most upregulated genes and proteins were involved in salt resistance strategies such as proline biosynthesis, the antioxidant defense system, ion homeostasis, and sugar accumulation at low salinity levels. On the other hand, the expression of several genes and proteins involved in the respiratory process were downregulated, indicating the inability of plants to meet their energy demands at high salinity levels. Moreover, the impairments in photosynthesis were also evident with the reduced expression of genes regulating the structure of photosystems and increased expression of abscisic acid (ABA) mediated pathways which limits stomatal gas exchange. Similarly, the disturbance in fatty acid metabolism and activation of essential ion transport blockers damaged the integrity of the cell membrane, which was also evident with enhanced malondialdehyde (MDA). Overall, the analysis of pathways revealed that the plant optimal performance at low salinity was related to enhanced metabolism, antioxidative defense, cell growth, and signaling pathways, whereas high salinity inhibited biomass accumulation by altered expression of numerous genes involved in carbon metabolism, signaling, transcription, and translation. The data provided the first global analysis of the mechanisms imparting salt stress tolerance of any halophyte at transcriptome and proteome levels.

Exposure to GenX and its novel analogs disrupts fatty acid metabolism in male mice

Perfluoroalkyl ether carboxylic acids (PFECAs), including hexafluoropropylene oxide dimer acid (HFPO-DA, GenX), have been widely used as alternatives to perfluorooctanoic acid (PFOA) and subsequently detected in various environmental matrices. Despite this, public information regarding their hepatotoxicity remains limited. Here, to compare the hepatotoxicity of PFECAs and identify better alternatives for GenX, adult male mice were exposed to different concentrations (0.4, 2, and 10 mg/kg/d) of PFOA, GenX, and its analogs (PFMO2HpA and PFMO3NA) for 28 d. Results demonstrated increased hepatomegaly and disturbed fatty acid metabolism with increasing treatment doses. After dimensionality reduction analysis, significant differences were observed in the relative liver weights and liver and serum biochemical parameters among the four clusters. Furthermore, when chemical concentrations in the liver were similar, no differences in the indicators of liver injury associated with fatty acid metabolism were observed among groups in the same clusters. Our results suggest that dimensionality reduction analysis is a useful strategy for analyzing samples exposed to multiple compounds at different doses. Furthermore, PFECAs exhibit similar hepatotoxicities at the same cumulative hepatic concentration in mice with constant body weight, while PFMO2HpA exhibits lower hepatotoxicity compared to GenX at the same dose.

CPT1 regulates the proliferation of pulmonary artery smooth muscle cells through the AMPK-p53-p21 pathway in pulmonary arterial hypertension.

Abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) plays a dominant role in the development of pulmonary arterial hypertension (PAH). Some studies and our previous work found that disturbance of fatty acid metabolism existed in PAH. However, the mechanistic link between fatty acid catabolism and cell proliferation remains elusive. Here, we identified an essential role and signal pathway for the key rate-limiting enzyme of mitochondrial fatty acid β-oxidation, carnitine palmitoyltransferase (CPT) 1, in regulating PASMC proliferation in PAH. We found that CPT1 was highly expressed in rat lungs and pulmonary arteries in monocrotaline-induced PAH, accompanied by decreased adenosine triphosphate (ATP) production and downregulation of the AMPK-p53-p21 pathway. Platelet-derived growth factor (PDGF)-BB upregulated the expression of CPT1 in a dose- and time-dependent manner. PASMC proliferation and ATP production induced by PDGF-BB were partly reversed by the CPT1 inhibitor etomoxir (ETO). The overexpression of CPT1 in PASMCs also promoted proliferation and ATP production and subsequently inhibited the phosphorylation of AMPK, p53, as well as p21 in PASMCs. Furthermore, AMPK was activated by ETO, which increased the expression of p53 and p21, and the proportion of cells in the cell cycle G2/M phase in response to PDGF-BB stimulation in PASMCs. Our work reveals a novel mechanism of CPT1 regulating PASMC proliferation in PAH, and regulation of CPT1 may be a potential target for therapeutic intervention in PAH.

Graphene oxide nano-bio interaction induces inhibition of spermatogenesis and disturbance of fatty acid metabolism in the nematode Caenorhabditis elegans

Graphene oxide (GO) has the potential for wide applications, which necessitates an intensive investigation of its potential hazard on human and environmental health. Even if previous studies show reproductive toxicity in the nematode Caenorhabditis elegans, the mechanisms of reproductive toxicity by GO are poorly understood. To understand the underlying mechanisms of GO-induced reproductive toxicity, we investigated the interaction between GO and C. elegans using Raman spectroscopy, sperm counts produced by spermatogenesis, progeny and analyzed the fatty acid metabolism using molecular techniques. GO-characteristic Raman spectral bands measured throughout C. elegans, brood size and Hoecst staining of dissected gonads clearly showed GO accumulation in the reproductive organs, reduced progeny and low sperm counts, which are possibly direct results of the reproductive toxicity from GO exposure. Interestingly, reduced fatty acid metabolites, such as stearic, oleic, palmitoleic, and palmitic acids, were found with GO exposure. We found that GO increased intestinal fat accumulation in wild type N2, fat-5(tm420), and fat-7(wa36) mutants, whereas it decreased fat storage in the fat-6(tm331) and nhr-49(nr2041) mutants. GO exposure affected C. elegans fat accumulation and consumption, which was possibly regulated by daf-16 and nhr-80 gene activity. Also, GO exposure suppressed the survival of long-lived fat-5(tm420) mutants, whereas it increased the survival of short-lived nhr-49(nr2041) mutants. Hence, our studies collectively indicated that GO accumulation in reproductive organs, suppression of spermatogenesis, and the alteration of fatty acid metabolism play critical roles in understanding mechanisms of toxicity in C. elegans.

Porphyromonas gingivalis Promotes 4-Nitroquinoline-1-Oxide-Induced Oral Carcinogenesis With an Alteration of Fatty Acid Metabolism.

Microbiota has been widely considered to play a critical role in human carcinogenesis. Human papilloma virus, hepatitis B and C virus, and Helicobacter pylori are implicated in the pathogenesis of cancer of uterine cervix, liver, and stomach, respectively. However, whether Porphyromonas gingivalis (P. gingivalis), a common Gram negative oral bacteria, is associated with oral carcinogenesis still remains unclear and its underlying mechanism needs to be addressed. Here, we established a combined experimental system of 4NQO-induced oral carcinoma model and chronic periodontitis model and investigated the effects of P. gingivalis infection on oral carcinogenesis and fatty acid metabolism during oral carcinogenesis. The data showed that in this animal model, P. gingivalis infection induced mice periodontitis, increased the tongue lesion size and multiplicity of each mouse and promoted oral cancer development. P. gingivalis treatment significantly increased the level of free fatty acids and altered the fatty acid profile in tongue tissues and the serum of mice. And P. gingivalis induced the formation of fatty liver of the mice. Besides, immunohistochemical analysis and qRT-PCR showed that the expression of fatty-acid synthase and acetyl-CoA carboxylase 1 were increased in the tongue and liver tissues of 4NQO-treated mice infected with P. gingivalis. These results showed that P. gingivalis promoted oral carcinogenesis and aggravated disturbance of fatty acid metabolism, indicating a close association among P. gingivalis, lipid metabolic and oral carcinogenesis.

Mitochondria-mediated disturbance of fatty acid metabolism in proximal tubule epithelial cells leads to renal interstitial fibrosis.

To investigate the role of mitochondria-mediated fatty acid metabolism in proximal tubule cells in renal interstitial fibrosis. Intraperitoneal injection of folate was performed to induce renal interstitial fibrosis in mice. Polymerase chain reaction (PCR) was used to detect the expression of cytochrome c oxidase subunit IV (COX4IL) and phosphoenolpyruvate carboxykinase 1 (PCK1) in samples. Electron microscope was used to detect the activity of mitochondria. Serum creatinine and urea nitrogen were chosen as evaluation criteria for renal function. Western-blotting was used to detect protein expression of cells. Immunohistochemistry was used to test renal structure and deposition of collagen. In renal interstitial fibrosis, mitochondria mediated the dysfunction and the promotion of tubulointerstitial fatty acid metabolism. Besides, it could also reduce renal interstitial fibrosis and alleviate the fatty acid metabolism of tubulointerstitial fibrosis. Mitochondrial dysfunction induced fatty acid metabolism is an important factor to promote the progress of renal interstitial fibrosis. Intervention of related targets of fatty acid metabolism is expected to become a new treatment for renal interstitial fibrosis.

Association between increased visceral fat area and alterations in plasma fatty acid profile in overweight subjects: a cross-sectional study

BackgroundVisceral fat accumulation in overweight status has been resulted in changes of fatty acid profiles. The fatty acids profiles can be altered by fatty acid desaturase; the activity of which is highly associated with obesity and other metabolic diseases. We hypothesized that fatty acid composition, desaturase activity, and accumulation of visceral fat are interrelated. Thus, the aim of this study was to investigate the association between increased visceral fat area and alterations in plasma fatty acid profile in overweight subjects with different amounts of visceral fat.MethodsHealthy overweight subjects (25.0 kg/m2 ≤ BMI < 30 kg/m2, n=232) were classified into lower (T1), middle (T2), and upper tertiles (T3) according to L4 visceral fat area (T1: <71.8 cm2, T2: 71.8 cm2–99.6 cm2, T3: >99.6 cm2).ResultsThe T3 group showed higher amounts of cis-10-heptadecenoic acid and activity of C16 Δ9-desaturase and C18 Δ9-desaturase and lower activity of Δ5-desaturase than the T1 group. Additionally, the T3 group showed higher amounts of saturated fatty acids, myristic acid, palmitic acid, stearic acid, monounsaturated fatty acids, palmitoleic acid, oleic acid, n-6 polyunsaturated fatty acids, linoleic acid, dihomo-γ-linolenic acid, arachidonic acid, n-3 PUFAs, and docosapentaenoic acid than the T1 and T2 groups.ConclusionsThis study indicates that greater than a certain area (>99.6 cm2) of visceral fat is needed to observe altered levels of individual fatty acid species and desaturase activities. The results suggest that increased activity of C16 Δ9-desaturase and C18 Δ9-desaturase in parallel with decreased Δ5-desaturase activity may be a causative factor in disturbed fatty acid metabolism.

Metabonomic potential plasma biomarkers in abnormal fast buoyancy ascent escape-induced decompression sickness model and the protective effects of pyrrolidine dithiocarbamic acid.

Decompression sickness (DCS) induced by fast buoyancy ascent escape (FBAE) is a special DCS, characterized with cardiopulmonary injuries. Serum metabonomics of this type of DCS has not yet been studied. We proposed a metabonomics approach for assessing serum metabonomics changes and evaluating the preventive effect of pyrrolidine dithiocarbamic acid (PDTC) in FBAE-induced DCS rats. Sixty-five (65) rats were divided into three groups, including the Control, DCS and PDTC groups. After receiving physiological saline or PDTC pretreatment, rats in the DCS and PDTC groups received the same protocol of simulated FBAE. Following this, a metabonomics approach - combined with pattern recognition methods including PCA and PLS-DA - was used to characterize the global serum metabolic profile on survival rats (five rats per group) associated with abnormal FBAE-induced DCS. As the VIP-value threshold cutoff of the metabolites was set to 2, metabolites above this threshold were filtered out as potential target biomarkers. Sixteen (16) distinct potential biomarkers in rat plasma were identified. PDTC significantly lowered DSC mortality from 60% to 10%, and alleviated ultrastructural alteration of the left ventricular apex compared to the DCS group. It was found that abnormal FBAE-induced DCS was closely related to disturbed fatty acid metabolism, glycerophospholipid metabolism, sterol lipid metabolism, and bile acid metabolism. With the presented metabonomic method, we systematically analyzed the protective effects of PDTC. The results demonstrated that PDTC administration could provide satisfactory effects on abnormal FBAE-induced DCS through partially regulating the perturbed metabolic pathways.

Targeting fatty acid metabolism to improve glucose metabolism.

Disturbances in fatty acid metabolism in adipose tissue, liver, skeletal muscle, gut and pancreas play an important role in the development of insulin resistance, impaired glucose metabolism and type 2 diabetes mellitus. Alterations in diet composition may contribute to prevent and/or reverse these disturbances through modulation of fatty acid metabolism. Besides an increased fat mass, adipose tissue dysfunction, characterized by an altered capacity to store lipids and an altered secretion of adipokines, may result in lipid overflow, systemic inflammation and excessive lipid accumulation in non-adipose tissues like liver, skeletal muscle and the pancreas. These impairments together promote the development of impaired glucose metabolism, insulin resistance and type 2 diabetes mellitus. Furthermore, intrinsic functional impairments in either of these organs may contribute to lipotoxicity and insulin resistance. The present review provides an overview of fatty acid metabolism-related pathways in adipose tissue, liver, skeletal muscle, pancreas and gut, which can be targeted by diet or food components, thereby improving glucose metabolism.

Metabolomic Study of Biochemical Changes related of toxicity induced by bupleurotoxin Using LC-MS Coupled with a Pattern Recognition Approach

The purpose of this study was to detect changes in urine of mice and to clarify the toxicity induced by bupleurotoxin (BETX) using liquid chromatography/quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). A procedure for urine analysis using pattern recognition was proposed to evaluate the toxicity induced by BETX in male BALB/c mice. BETX at 2.5 mg/kg was administrated intraperitoneally (i.p.), and urine samples for the metabolomic study were collected from control and BETX experimental groups. Changes in the concentrations of some urine metabolites were detected exclusively in the experimental group. All results suggested that exposure to BETX might cause a disturbance in fatty acid metabolism and the oxidative stress system. These results may not only clarify the underlying mechanism of diverse intoxication effects of BETX but also provide the guidance in preclinical toxicity screening for new drugs.

Erratum to: Study on the binding interaction between perfluoroalkyl acids and DNA

Abstract Perfluoroalkyl acids (PFAAs) are carcinogens,and elucidating their DNA binding properties is crucial forunderstanding PFAA genotoxicity. We have investigated thebinding mode and affinity of five PFAAs to seven DNAmolecules using fluorescence displacement and moleculardockinganalysis. DNA conformational changes uponPFAAbinding were also examined by circular dichroism (CD).The data revealed that DNA intercalation was the dominantinteraction mode of the PFAAs; however, these moleculesalso bound to grooves. The dissociation constants for thePFAAs ranged between 0.11 and 1,217.14 μM, and between3.46 and 2,141.21 μM for DNA intercalation and groovebinding, respectively. PFAAs that contain longer carbonchains had stronger DNA intercalation affinities. Bindingto DNA was stronger for perfluoroalkyl sulfonates than forperfluorcarboxyl acids that contain the same number ofcarbons. This observation is postulated to arise from thepresenceofmorefluorineandoxygenatomsinperfluoroalkylsulfonates acting as hydrogen bond donors that facilitatestronger DNA intercalation. The binding of the PFAAs toDNA showed some CT-DNA sequence selectivity. Moleculardocking analysis confirmed the DNA binding mode andaffinities of the PFAAs. CD analysis revealed that thePFAAs weakened DNA base stacking and loosened DNAhelicity.Thepresentstudyhasimprovedourunderstandingofthe formation of PFAA–DNA adducts.Keywords Perfluoroalkylacids .DNAbinding .Intercalation .Minorgroovebinding .DNAconformationalchange .DNAsequenceselectivityIntroductionPerfluoroalkyl acids (PFAAs) have been produced and usedfor over 50 years. Because of their specific physical andchemical properties, chemical and thermal inertness, lowsurface energy, and special surface-active properties,PFAAs have applications in numerous industrial and con-sumer products, ranging from carpet protection to fire-fighting foams (Lehmler 2005; Martin et al. 2004). PFAAspersist ubiquitously in the environment, resisting hydrolysis,photolysis, and biodegradation because of the high energyof the carbon–fluorine bond (Hekster et al. 2003; Martin etal. 2004; Quinete et al. 2010). Although the toxicologicaleffects of these chemicals are still under investigation, manystudieshavereportedontheirdevelopmentalandreproductivetoxicity, neurotoxicity, immunotoxicity, and carcinogenicityinanimalsbothinvivoandinvitro(Heksteretal.2003;Lauetal. 2004; Slotkin et al. 2008). PFAAs can cause peroxisomalproliferation, mitochondrial dysfunction, disturbance of fattyacid metabolism, hepatocellular hypertrophy, changes in

Fatty acid catalytic enzymes in vascular smooth muscle cells play a crucial role in the pathogenesis of atherosclerosis

Purpose: Integrity of vascular smooth muscle cell (SMC) function plays an important role in the development and progression of atherosclerosis. Increasing evidence has given credit to elevated plasma free fatty acids as crucial risk factor for atherosclerotic disease in obese or diabetic patients. However, little is known about the molecular mechanism by which disturbance of fatty acid metabolism in VSMC results in atherosclerosis. In this study, we focused on two fatty acid catalytic enzymes, stearoyl-CoA desaturase 1 (SCD1), that catalyzes the synthesis of monounsaturated fatty acids (MUFA) from saturated fatty acids (SFA), and elongase of long chain fatty acids 6 (Elovl6), that catalyzes the elongation of long-chain SFA and MUFA. Methods and results: We first examined SCD1 and Elovl6 expressions in neointimal hyperplasia by immunohistochemistry. Both SCD1 and Elovl6 were co-localized with smooth muscle alpha-actin-positive cells in medial layer of normal vessels while they were dramatically increased in 14-day balloon-injured rat aortas or intimal thickening area of human coronary artery. Furthermore, SCD1 and Elovl6 mRNA expressions in cultured human aortic SMC (HASMC) were significantly increased by transforming growth factor-beta (TGF-b; 15.2-fold) or platelet-derived growth factor-BB (PDGF-BB; 2.4-fold) which is negative regulator of SMC differentiation. We next examined whether SCD1 or Elovl6 expressions affect cell proliferation in VSMC. Knockdown of SCD1 or Elovl6 expressions in HASMC significantly suppressed DNA synthesis measured by [3H]-thymidine incorporation (63% and 16%, respectively, relative to control, p<0.01). These effects were blunted by adenovirus-mediated overexpression. Furthermore, SCD1 or Elovl6 knockdown markedly induced p21 and p53 expressions, phospholyration of AMP-activated protein kinase (p-AMPK) and suppressed mTOR expression levels, which lead to inhibit cell proliferation. Of importance, analysis of FFA composition in VSMC showed that both SCD1 and Elovl6 knockdown markedly increased the proportion of palmitic acid, while decreased that of MUFAs such as palmitoleic acid or oleic acid. In accordance with these results, palmitic acid substantially suppressed DNA synthesis and induced p21 or p-AMPK expressions. Conclusions: Collectively, our results suggest that perturbation of fatty acid desaturation or elongation in VSMC causes the shift of fatty acid composition and the inhibition of cell proliferation. Therefore, fatty acid metabolism and composition is crucial for SMC proliferation and progression of atherosclerosis.

Metabonomic studies on potential plasma biomarkers in rats exposed to ionizing radiation and the protective effects of Hong Shan Capsule

An ultra performance liquid chromatography coupled to mass spectrometry-based metabonomic approach, combined with pattern recognition methods including PCA, PLS-DA, RF and heatmap, has been developed to characterize the global serum metabolic profile associated with ionizing radiation (IR). As the VIP-value threshold cutoff of the metabolites was set to 2, metabolites above this threshold were filtered out as potential target biomarkers. Nineteen distinct potential biomarkers in rat plasma were identified. To further elucidate the pathophysiology of IR, related metabolic pathways have been studied. It was found that IR was closely related to disturbed fatty acid metabolism, taurine and hypotaurine metabolism, sphingolipid metabolism, purine metabolism, pyrimidine metabolism, phospholipid catabolism, tryptophan metabolism, phenylalanine metabolism, and bile acid metabolism. With the presented metabonomic method, we systematically analyzed the protective effects of Traditional Chinese Medicine Hong Shan Capsule (HSC). The results demonstrated that HSC administration could provide satisfactory effects on IR through partially regulating the perturbed metabolic pathways.

Metabolic alteration in healthy men with first degree type 2 diabetic relatives

The recognition of prediabetic patients with the genetic risk of type 2 diabetes is very important as prediabetes is the last stage when manifestation of diabetes could be prevented by life style modification or drug intervention. This suggests the need for diagnostic processes to trace the risk of patients in time. The authors looked for metabolic differences between age and BMI in adjusted healthy men with or without first degree type 2 diabetic relatives. The study included 73 healthy men (21 with and 52 without) first-degree relatives with type 2 diabetes. Total body and muscle tissue glucose utilization, glucose tolerance did not differ between the two groups, but free fatty acid levels were not suppressed by glucose load in subjects with diabetic relatives. In addition the body fat content, leptin and IL-6 levels were higher, while adiponectin and the free fatty acid/adiponectin ratio were significantly lover in healthy men with diabetic relatives. In this group HDL cholesterol, and the large buoyant LDL fraction were lower whereas the high density LDL - small molecular lipid fraction was higher than those measured in subjects without diabetic relatives. These data suggest that deteriorations of insulin sensitivity and glucose tolerance is preceded by disturbances of fatty acid metabolism. The observed alteration in free fatty acid/adiponectin ratio, and/or the absence of free fatty acid suppression during glucose tolerance tests could be a screening tool for diabetes risk among men.