Glucose Consumption Levels Research Articles

Hypoxia-associated circular RNA RPPH1 modulates triple-negative breast cancer cell growth via the miR-1296-5p/TRIM14 axis

Hypoxia affects the advancement, metastasis, and metabolism of breast cancer (BC). The circular RNA ribonuclease P RNA component H1 (circRPPH1) (has_circ_0000515) is implicated in tumor progression. Nevertheless, the regulatory mechanism related to circRPPH1 in hypoxia-mediated triple-negative breast cancer (TNBC) progression is indistinct. The expression levels of circRPPH1, miR-1296-5p, tripartite motif-containing 14 (TRIM14) mRNA in tissue samples and cells were examined through quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, migration, and invasion were determined with Cell Counting Kit-8 (CCK-8) or transwell assays. The levels of glucose consumption and lactate production were assessed via the Glucose Assay Kit or Lactate Assay Kit. The protein levels of TRIM14, Glucose Transporter GLUT1 (GLUT1), and lactic dehydrogenase A (LDHA) were detected by western blot analysis. The targeting relationship between circRPPH1 or TRIM14 and miR-1296-5p was verified with dual-luciferase reporter assay. The role of circRPPH1 was confirmed via xenograft assay. We verified that circRPPH1 and TRIM14 expression were increased while miR-1296-5p expression was decreased in BC tissues and hypoxia-cultured TNBC cells. Functionally, circRPPH1 silencing reversed the promoting effect of hypoxia on viability, migration, invasion, and glycolysis of TNBC cells. CircRPPH1 knockdown repressed decreased TNBC cell growth in vivo. Mechanistically, circRPPH1 sponged miR-1296-5p to modulate TRIM14 expression. Also, miR-1296- 5p silencing restored circRPPH1 inhibition-mediated influence on the viability, migration, invasion, and glycolysis of hypoxia-treated TNBC cells. TRIM14 elevation overturned the inhibitory impact of miR-1296-5p mimic on viability, migration, invasion, and glycolysis of hypoxia-cultured TNBC cells. In conclusion, hypoxia-induced circRPPH1 fostered TNBC progression through regulation of the miR-1296-5p/TRIM14 axis, indicating that circRPPH1 was a promising target for TNBC treatment.

Circ_0025033 promotes the progression of ovarian cancer by activating the expression of LSM4 via targeting miR-184

BackgroundOvarian cancer (OC) is the leading disorder to threaten women’s lives. Numerous circular RNAs (circRNAs) were identified in cancers with dysregulation and involved in the pathogenesis of cancer. This study investigated the function and regulatory mechanism of circ_0025033 in OC development, aiming to provide a potential strategy for OC treatment. MethodsFor expression analysis, the expression levels of circ_0025033, LSM4 mRNA and miR-184 were detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the protein level of LSM4 expression was detected by western blot. For functional analysis, the capacities of colony formation, migration/invasion and glycolysis metabolism were assessed by colony formation assay, transwell assay and the levels of glucose consumption and lactate production. The interaction between miR-184 and circ_0025033 or LSM4 was predicted by the bioinformatics tool and validated by dual-luciferase reporter assay. Xenograft models were established to determine the role of circ_0025033 in vivo. ResultsThe expression of circ_0025033 and LSM4 was promoted in OC tissues and cells. Circ_0025033 knockdown or LSM4 knockdown blocked the ability of colony formation, migration/invasion and glycolysis metabolism in OC cells. In mechanism, circ_0025033 functioned as a “competing endogenous RNA (ceRNA)” to modulate LSM4 expression by targeting miR-184. LSM4 overexpression recovered the inhibitory effects on colony formation, migration/invasion and glycolysis metabolism caused by circ_0025033 knockdown. Moreover, circ_0025033 knockdown also inhibited tumor growth in vivo by regulating LSM4 and targeting miR-184. ConclusionCirc_0025033 promotes the progression of OC by regulating LSM4 expression via targeting miR-184, which provided a new strategy to treat OC.

Circ_0084043 promotes cell proliferation and glycolysis but blocks cell apoptosis in melanoma via circ_0084043-miR-31-KLF3 axis.

Melanoma is an aggressive malignant tumor. The crucial role of circular RNAs has been documented in many types of cancer, including melanoma. The objective of this study was to uncover the function of circ_0084043 in the biological process of melanoma and associated mechanism of action. The expression of circ_0084043, miR-31, and Krüppel-like factor 3 (KLF3) was determined by qRT-PCR. Cell proliferation and apoptosis were monitored by the MTT assay and flow cytometry assay, respectively. The progression of glycolysis was evaluated according to the levels of glucose consumption, lactate production, and ATP concentration using appropriate detection kits. The relationship between miR-31 and circ_0084043 or KLF3 was predicted by the bioinformatics tool and ascertained by the dual-luciferase reporter assay. The protein levels of KLF3 and glucose transporter 1 (Glut1) were quantified by western blot. A xenograft model was established to ascertain the role of circ_0084043 in vivo. As a result, circ_0084043 expression was reinforced in melanoma tissues and cells. Circ_0084043 knockdown inhibited cell proliferation, induced cell apoptosis, and restrained glycolysis. MiR-31 was a target of circ_0084043, and miR-31 deficiency reversed the role of circ_0084043 knockdown. KLF3 was targeted by miR-31, and KLF3 upregulation abolished the effects of miR-31 enrichment. Moreover, circ_0084043 knockdown impeded tumor growth in vivo and suppressed the level of Glut1 by modulating miR-31 and KLF3. Circ_0084043 promoted cell proliferation and glycolysis, and blocked apoptosis through the circ_0084043–miR-31–KLF3 regulatory axis in melanoma.

Effects of Shikonin on the Functions of Myeloid Dendritic Cells in a Mouse Model of Severe Aplastic Anemia.

This study is aimed at investigating the effects of shikonin, a pyruvate kinase M2 (PKM2) inhibitor, on the functions of myeloid dendritic cells (mDCs) in a mouse model of severe aplastic anemia (AA) generated by total body irradiation and lymphocyte infusion. Flow cytometry and qPCR were used to determine the proportions of PKM2+ mDCs and other immune indicators in the AA mice. Glucose consumption level, pyruvate generation level, and ATP content were used to determine the level of glycolytic metabolism in the mDCs. The survival rates of AA mice were evaluated after the administration of shikonin or the immunosuppressive agent cyclosporin A. The AA mice displayed pancytopenia, decreased CD4+/CD8+ cell ratio, increased perforin and granzyme levels in CD8+ cells, increased costimulatory CD80 and CD86 expressions, and inadequate regulatory T cell number. In vivo animal experiments showed that the shikonin-mediated inhibition of the PKM2 expression in mice was associated with high survival rates. In addition, the administration of cyclosporin A or shikonin decreased the expression of cytotoxic molecules and costimulatory CD80 and CD86 on CD8+ cells. Taken together, the results of this study indicated that shikonin could inhibit the activation and proliferation of mDCs as well as the activation of downstream cytotoxic T cells by reducing the PKM2 level in mDCs.

The lateral neocortex is critical for contextual fear memory reconsolidation

Memories are a product of the concerted activity of many brain areas. Deregulation of consolidation and reprocessing of mnemonic traces that encode fearful experiences might result in fear-related psychopathologies. Here, we assessed how pre-established memories change with experience, particularly the labilization/reconsolidation of memory, using the whole-brain analysis technique of positron emission tomography in male mice. We found differences in glucose consumption in the lateral neocortex, hippocampus and amygdala in mice that underwent labilization/reconsolidation processes compared to animals that did not reactivate a fear memory. We used chemogenetics to obtain insight into the role of cortical areas in these phases of memory and found that the lateral neocortex is necessary for fear memory reconsolidation. Inhibition of lateral neocortex during reconsolidation altered glucose consumption levels in the amygdala. Using an optogenetic/neuronal recording-based strategy we observed that the lateral neocortex is functionally connected with the amygdala, which, along with retrograde labeling using fluorophore-conjugated cholera toxin subunit B, support a monosynaptic connection between these areas and poses this connection as a hot-spot in the circuits involved in reactivation of fear memories.

Glycyrrhetinic Acid Improves Insulin-Response Pathway by Regulating the Balance between the Ras/MAPK and PI3K/Akt Pathways.

Glycyrrhetinic acid (GA), a bioactive component in the human diet, has been reported to improve hyperglycemia, dyslipidemia, insulin resistance and obesity in rats with metabolic syndrome. However, GA-specific target proteins and the mechanisms involved in the downstream signaling and cross-talk to improve insulin sensitivity have not been fully elucidated. In this study, the potential targets of GA were identified by chemical proteomics strategies using serial GA probes for target fishing and cell molecular imaging. Intracellular enzyme activity evaluation and insulin resistance models were used for validating the function of the target proteins on the downstream insulin signaling pathways. Collectively, our data demonstrate that GA improved the insulin-responsive pathway and glucose consumption levels via multiple diabetogenic factors that activated the insulin signaling pathway in HepG2 cells. GA improved Glucose transporter 4(GLUT4) expression by targeting the Ras protein to regulate the mitogen-activated protein kinase (MAPK) pathway. GA exhibited a strong inhibitory effect on IRS1ser307 phosphorylation in cells treated with the Protein kinase C (PKC) activator Phorbol 12-myristate 13-acetate (PMA.) Consistently, IRS1ser307 phosphorylation was also inhibited by GA in Free fatty acid (FFA)-treated HepG2 cells. GA also inhibited the PMA-induced phosphorylation of IκB kinase α/β (IKKα/β), c-Jun N-terminal kinase (JNK) and p38 proteins (P38), suggesting that IKKα/β, JNK and P38 activation is dependent on PKC activity.

PTBP1 knockdown overcomes the resistance to vincristine and oxaliplatin in drug-resistant colon cancer cells through regulation of glycolysis

Drug-resistant cancer cells exhibit increased glycolysis, and targeting glycolysis is considered as a novel strategy to overcome drug resistance. Polypyrimidine tract-binding protein (PTBP1) has been found to be a regulator of glycolysis, however, the role of PTBP1 in drug resistance remains to be elucidated. Herein, we found that PTBP1 was highly expressed in two drug-resistant colon cancer cell lines, vincristine-resistant HCT-8 cell line (HCT-8/V) and oxaliplatin-resistant HCT116 cell line (HCT116/L-OHP). The levels of glucose consumption and lactate production as well as expression of pyruvate kinase M2 isoform (PKM2) and hexokinase II (HK2) were elevated, while PKM1 level was reduced in HCT-8/V and HCT116/L-OHP cells when compared with the HCT-8 and HCT116 cells. PTBP1 knockdown enhanced the sensitivity of HCT-8/V and HCT116/L-OHP cells to vincristine and oxaliplatin, and caused reduction in glucose consumption and lactate production. PKM2 expression, but not HK2, was decreased and PKM1 expression level was increased in cells transfected with si-PTBP1. In addition, PTBP1 overexpression significantly induced glycolysis and reduced drug sensitivity, whereas the effects were attenuated by si-PKM2. Treatment with 2-deoxyglucose (2-DG) also attenuated the effect of PTBP1 overexpression on drug sensitivity. In conclusion, PTBP1 knockdown enhanced the sensitivity of drug-resistant colon cancer cells to vincristine and oxaliplatin through repression of glycolysis. Our study provided a promising therapeutic strategy to overcome drug resistance in colon cancer cells.

The Long Noncoding RNA Lncenc1 Maintains Naive States of Mouse ESCs by Promoting the Glycolysis Pathway.

SummaryThe naive embryonic stem cells (nESCs) display unique characteristics compared with the primed counterparts, but the underlying molecular mechanisms remain elusive. Here we investigate the functional roles of Lncenc1, a highly abundant long noncoding RNA in nESCs. Knockdown or knockout of Lncenc1 in mouse nESCs leads to a significantly decreased expression of core pluripotency genes and a significant reduction of colony formation capability. Furthermore, upon the depletion of Lncenc1, the expression of glycolysis-associated genes is significantly reduced, and the glycolytic activity is substantially impaired, as indicated by a more than 50% reduction in levels of glucose consumption, lactate production, and extracellular acidification rate. Mechanistically, Lncenc1 interacts with PTBP1 and HNRNPK, which regulate the transcription of glycolytic genes, thereby maintaining the self-renewal of nESCs. Our results demonstrate the functions of Lncenc1 in linking energy metabolism and naive state of ESCs, which may enhance our understanding of the molecular basis underlying naive pluripotency.

Reexamination of the Physiological Role of PykA in Escherichia coli Revealed that It Negatively Regulates the Intracellular ATP Levels under Anaerobic Conditions.

Pyruvate kinase is one of the three rate-limiting glycolytic enzymes that catalyze the last step of glycolysis, conversion of phosphoenolpyruvate (PEP) into pyruvate, which is associated with ATP generation. Two isozymes of pyruvate kinase, PykF and PykA, are identified in Escherichia coli PykF is considered important, whereas PykA has a less-defined role. Prior studies inactivated the pykA gene to increase the level of its substrate, PEP, and thereby increased the yield of end products derived from PEP. We were surprised when we found a pykA::Tn5 mutant in a screen for increased yield of an end product derived from pyruvate (n-butanol), suggesting that the role of PykA needs to be reexamined. We show that the pykA mutant exhibited elevated intracellular ATP levels, biomass concentrations, glucose consumption, and n-butanol production. We also discovered that the pykA mutant expresses higher levels of a presumed pyruvate transporter, YhjX, permitting the mutant to recapture and metabolize excreted pyruvate. Furthermore, we demonstrated that the nucleotide diphosphate kinase activity of PykA leads to negative regulation of the intracellular ATP levels. Taking the data together, we propose that inactivation of pykA can be considered a general strategy to enhance the production of pyruvate-derived metabolites under anaerobic conditions.IMPORTANCE This study showed that knocking out pykA significantly increased the intracellular ATP level and thus significantly increased the levels of glucose consumption, biomass formation, and pyruvate-derived product formation under anaerobic conditions. pykA was considered to be encoding a dispensable pyruvate kinase; here we show that pykA negatively regulates the anaerobic glycolysis rate through regulating the energy distribution. Thus, knocking out pykA can be used as a general strategy to increase the level of pyruvate-derived fermentative products.

The effect of AdipoRon on insulin sensitivity of mouse skeletal muscle cells and its mechanism

To observe the effect of AdipoRon, an adiponin receptor agonist, on insulin sensitivity in mouse myoblast cell line (C2C12) and to explore its mechanism. C2C12 was induced to differentiate into myoblasts by using horse serum. Then the cells were divided into 6 groups (9 double wells):blank control group, high dose AdipoRon group, low dose AdipoRon group, insulin group and the low dose AdipoRon with PI3K inhibitor (phosphatidylinositol 3 kinase) group and the insulin with PI3K inhibitor group. After cultured for 12 h, the supernatant was collected and glucose consumption was measured. Cell proliferation was tested by using CCK8. In the 6-well plate, C2C12 was induced to differentiate into myoblasts. The drug was incubated for 12 h and the mRNA level of GLUT4 was detected by RT-PCR. Compared with the blank control group, the levels of glucose consumption in high dose AdipoRon group, low dose AdipoRon group and insulin group was increased significantly (P<0.05). After adding PI3K inhibitor, the levels of glucose consumption in the above mentioned three groups were not different from that in blank control group. high dose AdipoRon group, low dose AdipoRon group and insulin group had proliferation, but only the insulin group was statistically significant (P<0.05). Compared with the control group, the levels of GLUT4 mRNA in AdipoRon high dose group, low dose AdipoRon group and insulin group were all higher than those in control group (P<0.05). After adding PI3K inhibitor, GLUT4 mRNA level was not statistically significant compared with blank control group. AdipoRon can increase the consumption of glucose without affecting cell proliferation, which may play a role in improving insulin sensitivity, but the specific mechanism remains to be further studied.

MTOR activation is critical for betulin treatment in renal cell carcinoma cells

Betulin, a natural product isolated from the bark of the birch trees, exhibits multiple anticancer effects. Activation of mTOR signaling pathway has been found in numerous cancers, including renal cell carcinoma (RCC). Here, we attempted to study whether mTOR signaling was essential for betulin to treat RCC. Based on cell survival and colony formation assays, we found that mTOR hyperactive RCC cell line 786-O cells were more sensitive to betulin treatment compared with mTOR-inactive Caki-2 cells. Knockdown of TSC2 in Caki-2 cells had similar results to 786-O cells, and mTOR silencing in 786-O cells rescued the inhibitory effect of betulin, indicating that betulin inhibited RCC cell proliferation in an mTOR-dependent manner. Furthermore, betulin treatment decreases the levels of glucose consumption and lactate production in 786-O cells, while minimal effects were observed in Caki-2 cells. In addition, betulin significantly inhibited the expression of PKM2 and HK2 in 786-O cells. Finally, knockdown of PKM2 or HK2 in 786-O reversed the anti-proliferative effects of betulin, and overexpression of PKM2 or HK2 in Caki-2 cells enhanced the sensitivity to betulin treatment. Taken together, these findings demonstrated the critical role of mTOR activation in RCC cells to betulin treatment, suggesting that betulin might be valuable for targeted therapies in RCC patients with mTOR activation.

Effervescent Granules Prepared Using Eucommia ulmoides Oliv. and Moso Bamboo Leaves: Hypoglycemic Activity in HepG2 Cells.

Eucommia ulmoides Oliv. (E. ulmoides Oliv.) and moso bamboo (Phyllostachys pubescens) leaves are used as folk medicines in central-western China to treat diabetes. To investigate the hypoglycemic activity of the effervescent granules prepared using E. ulmoides Oliv. and moso bamboo leaves (EBEG) in HepG2 cells, EBEG were prepared with 5% of each of polysaccharides and chlorogenic acids from moso bamboo and E. ulmoides Oliv. leaves, respectively. HepG2 cells cultured in a high-glucose medium were classified into different groups. The results displayed EBEG-treated cells showed better glucose utilization than the negative controls; thus, the hypoglycemic effect of EBEG was much greater than that of granules prepared using either component alone, thereby indicating that this effect was due to a synergistic action of the components. Further, glucose consumption levels in the cells treated with EBEG (156.35% at 200 μg/mL) and the positive controls (metformin, 162.29%; insulin, 161.52%) were similar. Thus, EBEG exhibited good potential for use as a natural antidiabetic agent. The hypoglycemic effect of EBEG could be due to the synergistic action of polysaccharides from the moso bamboo leaves and chlorogenic acids from E. ulmoides Oliv. leaves via the inhibition of alpha-glucosidase and glucose-6-phosphate displacement enzyme.

Monomeric ß-amyloid interacts with type-1 insulin-like growth factor receptors to provide energy supply to neurons.

ß-amyloid (Aß1−42) is produced by proteolytic cleavage of the transmembrane type-1 protein, amyloid precursor protein. Under pathological conditions, Aß1−42self-aggregates into oligomers, which cause synaptic dysfunction and neuronal loss, and are considered the culprit of Alzheimer's disease (AD). However, Aß1−42 is mainly monomeric at physiological concentrations, and the precise role of monomeric Aß1−42 in neuronal function is largely unknown. We report that the monomer of Aß1−42 activates type-1 insulin-like growth factor receptors and enhances glucose uptake in neurons and peripheral cells by promoting the translocation of the Glut3 glucose transporter from the cytosol to the plasma membrane. In neurons, activity-dependent glucose uptake was blunted after blocking endogenous Aß production, and re-established in the presence of cerebrospinal fluid Aß. APP-null neurons failed to enhance depolarization-stimulated glucose uptake unless exogenous monomeric Aß1−42 was added. These data suggest that Aß1−42 monomers were critical for maintaining neuronal glucose homeostasis. Accordingly, exogenous Aß1−42 monomers were able to rescue the low levels of glucose consumption observed in brain slices from AD mutant mice.

Edible Brown Alga E cklonia cava Derived Phlorotannin-Induced Anti-Adipogenic Activity in Vitro

The present study performed the bioactivity-monitored isolation of anti-adipogenic phlorotannins from Ecklonia cava as a part of the ongoing research to develop antiobesity nutraceuticals from natural origin. Extracts were partitioned into n-hexane, 85% aqueous MeOH, n-BuOH and water fractions. Their adipogenic activities were examined by measuring glycerol release level and adipogenic-related gene expression in differentiating 3T3-L1 preadipocytes. Among them, n-BuOH fractions significantly increased glycerol secretion and reduced the regulation of adipogenic transcription factors, peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), as well as tumor necrosis factor α (TNFα). Further separation from n-BuOH fraction led to the isolation of phlorotannins, triphlorethol-A, eckol and dieckol. Phlorotannins increased the glycerol secretion and reduced the glucose consumption levels of 3T3-L1 adipocytes. Moreover, the phlorotannins reduced the expression levels of PPARγ, C/EBPα and differentiation-dependent factor 1/sterol regulatory element-binding protein 1c, as well as downstream genes such as fatty acid binding protein-4, fatty acid transport protein-1, fatty acid synthase, Leptin and acyl-CoA synthetase 1. In addition, phlorotannins increased the mRNA expression of hormone-sensitive lipase while suppressing perilipin and TNFα expressions. Practical Applications Brown alga, Ecklonia cava, is one of the most common edible algae in East Asian countries and widely consumed throughout Korea and Japan because of its nutritional importance along with its medicinal value. Constituents of E. cava, especially phenolic compounds, are considered to possess several bioactivities against various complications and diseases. In this regard, this study provides valuable insights concerning the antiobesity potential of E. cava and effective ingredients. Results indicate that the isolated phlorotannins act as antiobesity agents and suggest possible mechanisms of action. Following this study, a better utilization of E. cava via proper extraction of antiobesity constituents will pave the way for future nutraceuticals with antiobesity value.

Effects of C-Xylopyranoside Derivative on Expression of the Basement Membrane Related Molecules of Oral Keratinocytes and Fibroblasts

Our research team successfully developed a tissue-engineered, human oral mucosa equivalent that has been transplanted as a graft to reconstruct mucosa defects. Phase I clinical trial to increase keratinized gingiva in Japan have been implemented under current good manufacturing practices standard. Because the specific and rigorous release testing for quality assurance/control is required on the day of grafting prior to the product release, we currently measure the glucose consumption level in the culture medium to detect the defectives in this protocol. However, a few substandard products such as a thin epithelium formation is unavoidably formed, which is due to “variations” within the grafts. In parallel with the development of different non-invasive assessments, pharmacological manipulation would be one way to increase the quality of the grafts and minimize the “variations” during manufacturing. Glycosaminoglycans (GAGs) and proteoglycans are one of the major components of extracellular matrix including basement membrane in oral mucosa and have many biological functions. Thus, they play an important role in homeostasis of the epithelium. Recently, C- Xylopyranoside derivatives is reported to increase GAGs and PGs biosynthesis and improve tissue morphogenesis in a skin organotypic culture model.

Metabolic reprogramming by KSHV in cellular transformation

Oncogenic Kaposi’s sarcoma-associated herpesvirus (KSHV) is causally linked to several human cancers including Kaposi’s sarcoma and primary effusion lymphoma. Despite intensive studies, little is known about how KSHV alters cellular metabolism during cellular transformation. Using a novel model of KSHV-induced cellular transformation of primary rat embryonic metanephric mesenchymal stem cells (MM), we found that KSHV-transformed MM (KMM) cells did not require glucose for growth and formation of colonies in soft agar. Consistent with these results, KMM cells had lower levels of glucose consumption, lactate production, oxygen consumption and intracellular ATP levels. Compared to MM cells, KMM cells had lower levels of glucose transporters GLUT1 and GLUT3. Genetic deletion of KSHV-encoded microRNA cluster or vFLIP gene from the viral genome, which resulted in reduced NF-κB activity, significantly increased glucose consumption and lactate production, and sensitized the cells to glucose deprivation. Accordingly, inhibition of the NF-κB pathway with either RelA siRNAs or inhibitor JSH-23 dramatically increased glucose consumption and lactate production. Thus, the insensitivity of KMM cells to glucose is mediated by the heightened NF-κB activity. In contrast to the insensitivity to glucose, KMM cells were sensitive to glutamine deprivation. Glucose deprivation further increased glutamine consumption of KMM cells. Inhibition of glutamine metabolism with amino oxyacetate (AOA), an inhibitor of glutamate-dependent transaminases, or epigallocatechin gallate (EGCG), an inhibitor of glutamate dehydrogenase (GDH) mimicked the effect of glutamine deprivation and effectively suppressed cell growth and formation of colonies in soft agar. Addition of nonessential amino acid (NEAA) mixture or asparagine alone was sufficient to restore the growth of KMM cells upon glutamine deprivation while dimethyl α-ketoglutarate only had partial effect, indicating that glutamine not only provided a carbon source to fuel the tricarboxylic acid (TCA) cycle but also supplied nitrogen for biosynthesis. Taken together, these results indicate that KMM cells depend neither on aerobic glycolysis nor on oxidative phosphorylation but instead on glutamine to support cell growth and transformation. Our findings also suggest that metabolic reprogramming might have a critical role in KSHV-induced cellular transformation.

Storage of pork meat under modified atmospheres containing vapors from commercial alcoholic beverages

The present study aimed to evaluate the effect of AB vapors on microbial, physicochemical, and sensory profile of pork meat stored in different MAP conditions. Pork pieces (10g) and cotton/cellulose absorbent cloths (2×2cm) were placed into compartmentalized Petri-dishes in two sections. Aliquots (1mL) of water (control), 30% v/v and 40% v/v ethanol, whisky, brandy, tsipouro, raki, and ouzo were added separately to the cotton/cellulose absorbent cloths. Each pork sample was placed in one compartment and cotton/cellulose absorbent cloths supplemented with different ABs were placed in a separate compartment of each Petri-dish. Samples were packaged in 40% CO2: 30% O2: 30% N2 and 80% O2: 20% CO2 and stored at 4 and 10°C. Total viable counts, Pseudomonas sp., Brochothrix thermosphacta, lactic acid bacteria, yeasts and molds, and Enterobacteriaceae, were enumerated during storage. Changes in pH, color (L*, a*, b*), odor, taste, and overall appearance of pork meat were also evaluated along with changes in organic acid levels via HPLC. At 4°C, lactic acid bacteria and B. thermosphacta were the dominant organisms under 40% CO2: 30% N2: 30% O2 and 80% O2: 20% CO2, respectively, while at 10°C, lactic acid bacteria dominated in both MAP conditions. All applied ABs were effective (p<0.05) against lactic acid bacteria, pseudomonads, and B. thermosphacta. The inhibitory effect of ABs was also reflected through lower levels of glucose consumption or accumulation of lactic, acetic, succinic, and formic acid compared to controls. Moreover, packaged samples in 40% CO2: 30% O2: 30% N2 exhibited a significant increase (p<0.05) of acetic acid during storage at 4°C, but the concentrations of acetic acid in samples exposed to AB vapors were lower than those in controls. Both antimicrobial active MAPs extended the shelf-life of pork meat by ca. 2-fold, while samples exposed to alcoholic beverages (especially ouzo) under 80% O2: 20% CO2 resulted in better (p<0.05) sensory properties compared to the respective samples under 40% CO2: 30% O2: 30% N2. Overall, vapor action of ABs in combination with MAP may constitute a promising, antimicrobial packaging technology for extending the shelf-life of pork meat.

Antihyperglycemic Glucosylated Coumaroyltyramine Derivatives from Teucrium viscidum

Eight new glucosylated coumaroyltyramine derivatives, teuvissides A-H (1-8), were isolated from whole plants of Teucrium viscidum. Their structures were elucidated using spectroscopic data and chemical methods. The antihyperglycemic activities of these compounds were evaluated in HepG2 cells and 3T3-L1 adipocytes, and all of the isolates elicited different levels of glucose consumption at a concentration of 2.0 μM. Teuvissides A (1), B (2), and F (6) induced 2.2-, 2.1-, and 2.2-fold changes, respectively, in the levels of glucose consumption in HepG2 cells and 2.5-, 2.1-, and 2.3-fold changes, respectively, in 3T3-L1 adipocytes relative to the basal levels.

Effect of Coptidis Rhizoma extracts in a water-based solution on insulin resistance in 3T3-L1 adipocytes.

The present study was designed to investigate effects and molecular mechanisms of Coptidis Rhizoma extracts (CRE) on the improvement of insulin resistance induced by tumor necrosis factor-α (TNF-α) in adipocytes. We examined whether CRE administration could directly influence the insulin resistance in 3T3-L1 adipocytes. Potential roles of CRE in glucose consumption, mRNA expression of peroxisome proliferators activated receptor (PPAR-γ), expression of insulin receptor substrate-1 (IRS-1) protein, and phosphorylation of IRS-1 Ser307 were also investigated in the present study. Our data demonstrated that TNF-α significantly reduced levels of glucose consumption and IRS-1 protein expression, while TNF-α increased the phosphorylation of IRS-1 Ser307 in adipocytes 24 h after the challenge, suggesting that TNF-α induced a condition with the occurrence of insulin resistance. Those alterations induced by TNF-α were prevented and the mRNA expression of PPAR-γ was up-regulated by the administration of CRE. Thus, our results indicate that CRE can be used to prevent from the TNF-α-induced insulin resistance through PPAR-γ pathways.

Abstract 768: MCL1 and glycolysis synergistically induce prednisolone resistance, which can be therapeutically reversed

Abstract Although cure rates for acute lymphoblastic leukemia (ALL) have greatly improved, contemporary treatment is still ineffective in 20% of patients. Unsuccessful treatment can be mainly ascribed to resistance towards antileukemic drugs. In particular prednisolone is highly associated with poor prognosis. Overcoming drug resistance is therefore necessary to increase current survival rates. Microarray analysis of precursor B-ALL patients revealed MCL1 as an important gene involved in prednisolone resistance (Holleman, N Engl J Med 2004). We demonstrated sensitization towards prednisolone after lentiviral silencing of MCL1 in prednisolone resistant leukemic cell lines (Stam, Blood 2009). These results point to MCL1 as an interesting candidate for targeted therapy. We also discovered that cells upregulate their glucose consumption level to protect from prednisolone induced apoptosis. 2-Deoxyglucose (2DG), an inhibitor of glycolysis, sensitized for prednisolone in leukemic cell lines and patients’ cells (Hulleman, Blood 2009). We here provide evidence for an inter-connection between MCL1, glycolysis and prednisolone resistance. A clear increase in glucose consumption was observed after targeting MCL1 in leukemic cells by both lentiviral silencing and mRNA antagonists. This suggests that cells upregulate glycolysis to prevent apoptosis induced upon MCL1 knockdown. Indeed, co-exposure to 2DG substantially decreased the proliferation rate of MCL1-silenced cells, and most importantly, synergized with silencing of MCL1 in reversing resistance to prednisolone. Altogether these data provide evidence for concomitant causes of resistance and indicate that MCL1 silencing and glycolysis inhibition can serve as potent ways to reverse resistance to prednisolone in acute leukemia. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 768. doi:1538-7445.AM2012-768