Nanoparticle targeting of neutrophil glycolysis prevents lung ischemia-reperfusion injury.

Neutrophils exacerbate pulmonary ischemia-reperfusion injury (IRI) resulting in poor short and long-term outcomes for lung transplant recipients. Glycolysis powers neutrophil activation, but it remains unclear if neutrophil-specific targeting of this pathway will inhibit IRI. Lipid nanoparticles containing the glycolysis flux inhibitor 2-deoxyglucose (2-DG) were conjugated to neutrophil-specific Ly6G antibodies (NP-Ly6G[2-DG]). Intravenously administered NP-Ly6G(2-DG) to mice exhibited high specificity for circulating neutrophils. NP-Ly6G(2-DG)-treated neutrophils were unable to adapt to hypoglycemic conditions of the lung airspace environment as evident by the loss of demand-induced glycolysis, reductions in glycogen and ATP content, and an increased vulnerability to apoptosis. NP-Ly6G(2-DG) treatment inhibited pulmonary IRI following hilar occlusion and orthotopic lung transplantation. IRI protection was associated with less airspace neutrophil extracellular trap generation, reduced intragraft neutrophilia, and enhanced alveolar macrophage efferocytotic clearance of neutrophils. Collectively, our data show that pharmacologically targeting glycolysis in neutrophils inhibits their activation and survival leading to reduced pulmonary IRI.

Deformation characteristics test and mechanism of arbor taproot soil complex in rainforests.

This study performed large-scale single shear tests on Haikou red clay and arbor taproot to explore the anti-sliding effect and deformation characteristics of rainforest arbor roots under a shallow landslide. The law of root deformation and the root-soil interaction mechanism were revealed. The results indicated the significant reinforcing effect of arbor roots on the shear strength and ductility of soil, which increased with the decrease of normal stress. The soil reinforcement mechanism of arbor roots was attributed to their friction and retaining effects through an analysis of the movement of soil particles and the deformation pattern of roots during the shear process. The root morphology of arbors under shear failure could be described using an exponential function. Consequently, an advanced Wu model which better reflected the stress state and deformation of roots was proposed based on the concept of curve segment superposition. The results are believed to a reliable experimental and theoretical basis for the in-depth study of soil consolidation and sliding resistance effects of arbor roots, and further lay a foundation for the slope protection by arbor roots.

Reprogramming alveolar macrophage responses to TGF-ß reveals CCR2+ monocyte activity that promotes bronchiolitis obliterans syndrome.

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients, but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-ß bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes were primarily engulfed by alveolar macrophages (AMs), which were reprogrammed to become less responsive to TGF-ß and reduce TGF-ß bioavailability through secretion of the TGF-ß antagonist decorin. In untreated recipients, high airway TGF-ß activity stimulated AMs to express CCL2, leading to CCR2+ monocyte-driven BOS development. Moreover, we found TGF-ß receptor 2-dependent differentiation of CCR2+ monocytes was required for the generation of monocyte-derived AMs, which in turn promoted BOS by expanding tissue-resident memory CD8+ T cells that inflicted airway injury through Blimp-1-mediated granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-ß-dependent network that couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS.

Necroptosis triggers spatially restricted neutrophil-mediated vascular damage during lung ischemia reperfusion injury.

Ischemia reperfusion injury represents a common pathological condition that is triggered by the release of endogenous ligands. While neutrophils are known to play a critical role in its pathogenesis, the tissue-specific spatiotemporal regulation of ischemia-reperfusion injury is not understood. Here, using oxidative lipidomics and intravital imaging of transplanted mouse lungs that are subjected to severe ischemia reperfusion injury, we discovered that necroptosis, a nonapoptotic form of cell death, triggers the recruitment of neutrophils. During the initial stages of inflammation, neutrophils traffic predominantly to subpleural vessels, where their aggregation is directed by chemoattractants produced by nonclassical monocytes that are spatially restricted in this vascular compartment. Subsequent neutrophilic disruption of capillaries resulting in vascular leakage is associated with impaired graft function. We found that TLR4 signaling in vascular endothelial cells and downstream NADPH oxidase 4 expression mediate the arrest of neutrophils, a step upstream of their extravasation. Neutrophil extracellular traps formed in injured lungs and their disruption with DNase prevented vascular leakage and ameliorated primary graft dysfunction. Thus, we have uncovered mechanisms that regulate the initial recruitment of neutrophils to injured lungs, which result in selective damage to subpleural pulmonary vessels and primary graft dysfunction. Our findings could lead to the development of new therapeutics that protect lungs from ischemia reperfusion injury.

Circulating mitochondrial DNA is an early indicator of severe illness and mortality from COVID-19.

BackgroundMitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether circulating cell-free MT-DNA quantitation could be used to predict the risk of poor COVID-19 outcomes remains undetermined.MethodsWe measured circulating MT-DNA levels in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at hospital presentation. Our primary outcome was mortality. Intensive care unit (ICU) admission, intubation, vasopressor, and renal replacement therapy requirements were secondary outcomes. Multivariate regression analysis determined whether MT-DNA levels were independent of other reported COVID-19 risk factors. Receiver operating characteristic and area under the curve assessments were used to compare MT-DNA levels with established and emerging inflammatory markers of COVID-19.ResultsCirculating MT-DNA levels were highly elevated in patients who eventually died or required ICU admission, intubation, vasopressor use, or renal replacement therapy. Multivariate regression revealed that high circulating MT-DNA was an independent risk factor for these outcomes after adjusting for age, sex, and comorbidities. We also found that circulating MT-DNA levels had a similar or superior area under the curve when compared against clinically established measures of inflammation and emerging markers currently of interest as investigational targets for COVID-19 therapy.ConclusionThese results show that high circulating MT-DNA levels are a potential early indicator for poor COVID-19 outcomes.FundingWashington University Institute of Clinical Translational Sciences COVID-19 Research Program and Washington University Institute of Clinical Translational Sciences (ICTS) NIH grant UL1TR002345.

Galuminox: Preclinical validation of a novel PET tracer for non-invasive imaging of oxidative stress in vivo.

Overproduction of reactive oxygen species (ROS) is a well-established indicator of ongoing tissue inflammation. However, there is a scarcity of molecular imaging probes capable of providing noninvasive sensitive detection of ROS for allowing longitudinal studies of disease pathology and/or monitoring therapeutic efficacy of ROS scavengers. Herein, we report synthesis and chemical characterization of a novel metalloprobe, Galuminox, a moderately fluorescent agent that detects superoxide and hydrogen peroxide generation. Using live-cell fluorescence imaging analysis, Galuminox demonstrates ability to detect superoxide and monitor effects of ROS-attenuating agents, such as Carvedilol, Dexrazoxane, and mitoTempo in lung epithelial A549 cells. Furthermore, LPS stimulation of A549 cells that either express the mitochondria targeted fluorescent protein Keima or are stained with MitoSOX, a mitochondria-specific superoxide probe, indicates preferential co-localization of Galuminox with mitochondria producing elevated amounts of superoxide. Dynamic PET/CT scans 45 min post tail-vein administration of 68Ga-Galuminox show 4-fold higher uptake and stable retention in lungs of LPS treated mice compared to their saline-only treated counterparts. Post preclinical PET imaging, quantitative biodistribution studies also correlate with 4-fold higher retention of the radiotracer in lungs of LPS treated mice compared with their saline-only treated control counterparts. Consistent with these observations, lung cells isolated from LPS-treated mice demonstrated elevated ROS production deploying CellROX, the ROS probe. Finally, Galuminox uptake correlates with histological and physiological evidence of acute lung injury as evident by polynuclear infiltration, thickening of the alveolar epithelial membranes and increased bronchioalveolar lavage protein content. Taken collectively, these data indicate that 68Ga-Galuminox tracer uptake is a measure of ROS activity in acutely injured lungs and suggests its potential utility in monitoring oxidative stress in other diseases.

Circulating Mitochondrial DNA is an Early Indicator of Severe Illness and Mortality from COVID-19.

Mitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether the appearance of cell-free MT-DNA is linked to poor COVID-19 outcomes remains undetermined. Here, we quantified circulating MT-DNA in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at the time of hospital presentation. Circulating MT-DNA were sharply elevated in patients who eventually died, required ICU admission or intubation. Multivariate regression analysis revealed that high circulating MT-DNA levels is an independent risk factor for all of these outcomes after adjusting for age, sex and comorbidities. Additionally, we found that circulating MT-DNA has a similar or superior area-under-the curve when compared to clinically established measures of systemic inflammation, as well as emerging markers currently of interest as investigational targets for COVID-19 therapy. These results show that high circulating MT-DNA levels is a potential indicator for poor COVID-19 outcomes.

Ecological security and health risk assessment of soil heavy metals on a village-level scale, based on different land use types.

Land use affects the accumulation of heavy metals in soil, which will endanger ecological safety and human health. Taking the village as an administrative unit, the ecological safety and health risks of heavy metals, namely, Cr, Cu, Zn, and Pb in soils in the Houzhai River Watershed of Guizhou Province, China, were evaluated based on land use types by the Hakanson potential ecological risk methods and human health risk model. Results showed that the spatial heterogeneity of Cu and Zn was greatly affected by primary structural factors, and Cr and Pb were interfered by both structural factors and human activities. The geo-accumulation index of the heavy metals showed a light pollution in the study area. The comprehensive potential ecological risk of heavy metal in the area was divided into three levels: slight, moderate, and intense, and it is spatially high in the northwest and low in the southeast. Both non-carcinogenic risk and carcinogenic risk of the heavy metals to the human body are not significant and are acceptable. The risks of children are higher than adults, and direct intake is the primary route of exposure in the area. The potential ecological risk and human health risk of soil heavy metals are relatively obviously affected by digital elevation data and normalized vegetation index. The study has certain reference value for the prevention and control of regional soil heavy metal risk.

Adipose tissue monomethyl branched-chain fatty acids and insulin sensitivity: Effects of obesity and weight loss.

OBJECTIVES: An increase in circulating branched-chain amino acids (BCAA) is associated with insulin resistance. Adipose tissue is a potentially important site for BCAA metabolism. It was evaluated whether monomethyl branched-chain fatty acids (mmBCFA) in adipose tissue, which are likely derived from BCAA catabolism, are associated with insulin sensitivity. METHODS: Insulin-stimulated glucose disposal was determined by using the hyperinsulinemic-euglycemic clamp procedure with stable isotope glucose tracer infusion in nine lean and nine obese subjects, and in a separate group of nine obese subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery (38% weight loss). Adipose tissue mmBCFA content was measured in tissue biopsies taken in the basal state. RESULTS: Total adipose tissue mmBCFA content was ∼30% lower in obese than lean subjects (P=0.02) and increased by ∼65% after weight loss in the RYGB group (P=0.01). Adipose tissue mmBCFA content correlated positively with skeletal muscle insulin sensitivity (R(2) =35%, P=0.01, n=18). CONCLUSIONS: These results demonstrate a novel association between adipose tissue mmBCFA content and obesity-related insulin resistance. Additional studies are needed to determine whether the association between adipose tissue mmBCFA and muscle insulin sensitivity is causal or a simple association.

The brown fat-enriched secreted factor Nrg4 preserves metabolic homeostasis through attenuation of hepatic lipogenesis.

Brown fat activates uncoupled respiration in response to cold temperature and contributes to systemic metabolic homeostasis. To date, the metabolic action of brown fat has been primarily attributed to its role in fuel oxidation and uncoupling protein 1 (UCP1)-mediated thermogenesis. Whether brown fat engages other tissues through secreted factors remains largely unexplored. Here we show that neuregulin 4 (Nrg4), a member of the epidermal growth factor (EGF) family of extracellular ligands, is highly expressed in adipose tissues, enriched in brown fat and markedly increased during brown adipocyte differentiation. Adipose tissue Nrg4 expression was reduced in rodent and human obesity. Gain- and loss-of-function studies in mice demonstrated that Nrg4 protects against diet-induced insulin resistance and hepatic steatosis through attenuating hepatic lipogenic signaling. Mechanistically, Nrg4 activates ErbB3 and ErbB4 signaling in hepatocytes and negatively regulates de novo lipogenesis mediated by LXR and SREBP1c in a cell-autonomous manner. These results establish Nrg4 as a brown fat-enriched endocrine factor with therapeutic potential for the treatment of obesity-associated disorders, including type 2 diabetes and nonalcoholic fatty liver disease (NAFLD).

Exploring the stability of long intergenic non-coding RNA in K562 cells by comparative studies of RNA-Seq datasets.

BACKGROUND: The stability of long intergenic non-coding RNAs (lincRNAs) that possess tissue/cell-specific expression, might be closely related to their physiological functions. However, the mechanism associated with stability of lincRNA remains elusive. In this study, we try to study the stability of lincRNA in K562 cells, an important model cell, through comparing two K562 transcriptomes which are obtained from ENCODE Consortium and our sequenced RNA-Seq dataset (PH) respectively. RESULTS: By lincRNAs analysis pipeline, 1804 high-confidence lincRNAs involving 1564 annotated lincRNAs and 240 putative novel lincRNAs were identified in PH, and 1587 high-confidence lincRNAs including 1429 annotated lincRNAs and 158 putative novel lincRNAs in ENCODE. There are 1009 unique lincRNAs in PH, 792 unique lincRNAs were in ENCODE, and 795 overlapping lincRNAs in both datasets. The analysis of differences in minimum free energy distribution and lincRNA half-life showed that a large proportion of overlapping lincRNAs were more stable than the unique lincRNAs. Most lincRNAs were more unstable than protein-coding RNAs through comparing their minimum free energy. CONCLUSIONS: Identification of overlapping and unique lincRNAs can be helpful to classify the stability of lincRNAs. Our results suggest that overlapping lincRNAs (relatively stable linRNAs) and unique lincRNAs (relatively unstable lincRNAs) might be involved in different cellular processes. REVIEWERS: This article has been reviewed by Prof. Oliviero Carugo, Dr. Alistair Forrest and Prof. Manju Bansal.

A new species of the genus Thoracochirus Bernhauer (Coleoptera: Staphylinidae: Osoriinae) from Yunnan, China.

Thoracochirus yunxianius sp. nov. is described from Yunnan, China. Color images of the habitus and aedeagus of the new species are included. A key to the genus Thoracochirus of mainland China species is provided.

CD36 protein influences myocardial Ca2+ homeostasis and phospholipid metabolism: conduction anomalies in CD36-deficient mice during fasting.

Sarcolemmal CD36 facilitates myocardial fatty acid (FA) uptake, which is markedly reduced in CD36-deficient rodents and humans. CD36 also mediates signal transduction events involving a number of cellular pathways. In taste cells and macrophages, CD36 signaling was recently shown to regulate store-responsive Ca(2+) flux and activation of Ca(2+)-dependent phospholipases A(2) that cycle polyunsaturated FA into phospholipids. It is unknown whether CD36 deficiency influences myocardial Ca(2+) handling and phospholipid metabolism, which could compromise the heart, typically during stresses. Myocardial function was examined in fed or fasted (18-22 h) CD36(-/-) and WT mice. Echocardiography and telemetry identified conduction anomalies that were associated with the incidence of sudden death in fasted CD36(-/-) mice. No anomalies or death occurred in WT mice during fasting. Optical imaging of perfused hearts from fasted CD36(-/-) mice documented prolongation of Ca(2+) transients. Consistent with this, knockdown of CD36 in cardiomyocytes delayed clearance of cytosolic Ca(2+). Hearts of CD36(-/-) mice (fed or fasted) had 3-fold higher SERCA2a and 40% lower phospholamban levels. Phospholamban phosphorylation by protein kinase A (PKA) was enhanced after fasting reflecting increased PKA activity and cAMP levels in CD36(-/-) hearts. Abnormal Ca(2+) homeostasis in the CD36(-/-) myocardium associated with increased lysophospholipid content and a higher proportion of 22:6 FA in phospholipids suggests altered phospholipase A(2) activity and changes in membrane dynamics. The data support the role of CD36 in coordinating Ca(2+) homeostasis and lipid metabolism and the importance of this role during myocardial adaptation to fasting. Potential relevance of the findings to CD36-deficient humans would need to be determined.

CD36 level and trafficking are determinants of lipolysis in adipocytes.

CD36 has been linked to the etiology of insulin resistance and inflammation. We explored its function in regulating adipose tissue lipolysis, which influences fat accumulation by liver and muscle and overall metabolism. Knockdown of CD36 in differentiated 3T3-L1 adipocytes decreased lipolysis in response to 10 µM of the ß-adrenergic agonist isoproterenol (by 42%), 10 µM of the adenyl cyclase activator forskolin (by 32%), and 500 µM of the phosphodiesterase (PDE) inhibitor isobutylmethylxanthine (by 33%). All three treatments in the knockdown adipocytes were associated with significant decreases of cAMP levels and of the hormone-sensitive lipase (HSL) and perilipin phosphorylation. An important role for PDE was supported by the lack of inhibition of the lipolysis induced by the poorly hydrolyzable dibutyryl cAMP analog. An additional contributory mechanism was diminished activation of the Src-ERK1/2 pathway. Regulation of lipolysis and lipolytic signaling by CD36 was reproduced with adipose tissue from CD36(-/-) mice. The importance of surface CD36 in this regulation was suggested by the finding that the plasma membrane-impermeable CD36 inhibitor sulfo-N-succinimidyl oleate (20 µM) decreased lipolysis. Interestingly, isoproterenol induced CD36 internalization, and this process was blocked by HSL inhibition, suggesting feedback regulation of adipocyte lipolysis via CD36 trafficking.

Decreased hepatic glucose production in obese rats by dipeptidyl peptidase-IV inhibitor sitagliptin.

BACKGROUND: Dipeptidyl peptidase-IV (DPP-4) inhibitors are now used to improve postprandial glycemic control in type 2 diabetes. However, their effects on hepatic glucose production (HGP) in obesity are not clear. This study was designed to test the hypothesis that gluconeogenesis and HGP can be modulated by DPP-4 inhibitors in obesity. METHODS: Sprague Dawley male rats were divided into four groups, each on a different diet: general rat chow, n = 10 (G); G + sitagliptin, n = 10; high fat chow (obesity), n = 10 (55% fat calories, HFO); HFO + sitagliptin, n = 10. After 10 weeks, the rats were fasted overnight and glucose metabolism was determined using 3-(3)H-glucose and (14)C-glycerol as tracers. RESULTS: Glycerol rate of appearance (P < 0.00001), plasma glycerol (P < 0.05) and free fatty acid (FFA) (P < 0.05) concentrations, and HGP (P < 0.05) were decreased in HFO + sitagliptin group compared with HFO group, but there was no significant difference between G and G + sitagliptin groups (P > 0.05). Gluconeogenesis in HFO group was five times of that in G rats (P < 0.01), but was significantly declined in HFO + sitagliptin group (P < 0.0001). CONCLUSIONS: Gluconeogenesis and HGP were inhibited by sitagliptin in high fat-induced obese rats due to decreased glycerol availability, which was a result of reduced glycerol release from adipose tissues. The finding suggests that sitagliptin is potentially useful for controlling fasting glucose in obesity, thereby delaying or preventing the development of diabetes.

Stereospecificity of fatty acid 2-hydroxylase and differential functions of 2-hydroxy fatty acid enantiomers.

FA 2-hydroxylase (FA2H) is an NAD(P)H-dependent enzyme that initiates FA α oxidation and is also responsible for the biosynthesis of 2-hydroxy FA (2-OH FA)-containing sphingolipids in mammalian cells. The 2-OH FA is chiral due to the asymmetric carbon bearing the hydroxyl group. Our current study performed stereochemistry investigation and showed that FA2H is stereospecific for the production of (R)-enantiomers. FA2H knockdown in adipocytes increases diffusional mobility of raft-associated lipids, leading to reduced GLUT4 protein level, glucose uptake, and lipogenesis. The effects caused by FA2H knockdown were reversed by treatment with exogenous (R)-2-hydroxy palmitic acid, but not with the (S)-enantiomer. Further analysis of sphingolipids demonstrated that the (R)-enantiomer is enriched in hexosylceramide whereas the (S)-enantiomer is preferentially incorporated into ceramide, suggesting that the observed differential effects are in part due to synthesis of sphingolipids containing different 2-OH FA enantiomers. These results may help clarify the mechanisms underlying the recently identified diseases associated with FA2H mutations in humans and may lead to potential pharmaceutical and dietary treatments. This study also provides critical information to help study functions of 2-OH FA enantiomers in FA α oxidation and possibly other sphingolipid-independent pathways.

Locating the source of hyperglycemia: liver versus muscle.

BACKGROUND: Glucose homeostasis relies on insulin to suppress hepatic glucose production and to stimulate glucose uptake by peripheral tissues (primarily skeletal muscle) during and after a meal or glucose load. Glucose metabolism impairments in the liver and/or muscle attenuate these insulin actions, causing hyperglycemia. Thus, identifying the loci of the impairments can improve the understanding of hyperglycemia and enable organ-targeted interventions. METHODS: Studies were performed to identify such loci using modified oral glucose tolerance test (OGTT) techniques in individuals with type 2 diabetes (T2D) and overweight/obese individuals. RESULTS: Individuals with severe T2D were found to have significantly impaired glucose metabolism in both the liver and muscle. In contrast, impairments in glucose metabolism in individuals with non-severe T2D were predominantly localized in the liver or muscle, but not both. Similarly, milder impairments in overweight or obese individuals were clearly localized in either the liver or muscle, but not both. All these impairments are quantifiable. CONCLUSION: Impairments in glucose metabolism in the liver and muscle can be differentiated and quantified in a clinical setting.

Global analysis of in vivo EGR1-binding sites in erythroleukemia cell using chromatin immunoprecipitation and massively parallel sequencing.

Early growth response gene 1 (EGR1) has been implicated in megakaryocyte differentiation induced by phorbol ester. But the molecule mechanism of EGR1 in this process has not been widely investigated. The identification of direct EGR1 target genes in a global scale is critical for our understanding of how EGR1 contributes to this process. In this study, we provide a global survey on the binding location of EGR1 in the K562 cells using chromatin immunoprecipitation and massively parallel sequencing. Over 14 000 highly confident in vivo EGR1 binding sites were identified in phorbol 12-myristate 13-acetate-treated K562 cells. More than 70% of these genomic sites associated with EGR1 binding were located around annotated gene regions. Molecular functional classification of 6138 putative EGR1 target genes showed that the transcription factor class (695 of 6138; 11%) is the largest significantly enriched one. The results showed that a high coverage of the genome and a high positive rate achieve were achieved. This whole genome study on the EGR1 targets may provide a better understanding of the EGR1 regulated genes and the downstream pathway in megakaryocyte differentiation.

Fatty acid 2-hydroxylase mediates diffusional mobility of Raft-associated lipids, GLUT4 level, and lipogenesis in 3T3-L1 adipocytes.

Straight chain fatty acid alpha-oxidation increases during differentiation of 3T3-L1 adipocytes, leading to a marked accumulation of odd chain length fatty acyl moieties. Potential roles of this pathway in adipocyte differentiation and lipogenesis are unknown. Mammalian fatty acid 2-hydroxylase (FA2H) was recently identified and suggested to catalyze the initial step of straight chain fatty acid alpha-oxidation. Accordingly, we examined whether FA2H modulates adipocyte differentiation and lipogenesis in mature adipocytes. FA2H level markedly increases during differentiation of 3T3-L1 adipocytes, and small interfering RNAs against FA2H inhibit the differentiation process. In mature adipocytes, depletion of FA2H inhibits basal and insulin-stimulated glucose uptake and lipogenesis, which are partially rescued by the enzymatic product of FA2H, 2-hydroxy palmitic acid. Expression of fatty-acid synthase and SCD1 was decreased in FA2H-depleted cells, and levels of GLUT4 and insulin receptor proteins were reduced. 2-Hydroxy fatty acids are enriched in cellular sphingolipids, which are components of membrane rafts. Accelerated diffusional mobility of raft-associated lipids was shown to enhance degradation of GLUT4 and insulin receptor in adipocytes. Consistent with this, depletion of FA2H appeared to increase raft lipid mobility as it significantly accelerated the rates of fluorescence recovery after photobleaching measurements of lipid rafts labeled with Alexa 488-conjugated cholera toxin subunit B. Moreover, the enhanced recovery rates were partially reversed by treatment with 2-hydroxy palmitic acid. In conclusion, our findings document the novel role of FA2H in adipocyte lipogenesis possibly by modulation of raft fluidity and level of GLUT4.