Increased Lactate Dehydrogenase Activity Research Articles

Metabolome Analysis Reveals Excessive Glycolysis via PI3K/AKT/mTOR and RAS/MAPK Signaling in Methotrexate-Resistant Primary CNS Lymphoma-Derived Cells.

Metabolome analysis is an emerging method that provides insight into intracellular and physiologic responses. Methotrexate (MTX) is an antifolate that suppresses DNA syntheses by inhibiting dihydrofolate reductase. High-dose methotrexate treatment with deferred radiotherapy is a standard protocol in primary central nervous system lymphoma (PCNSL) treatments. However, most cases come to relapse-acquired resistance, in which the role of metabolic pathways is largely unknown. Metabolome analysis in methotrexate-resistant PCNSL-derived cells (designated as TK-MTX and HKBML-MTX) was performed to detect alternative metabolites and pathways. The metabolomic analyses using capillary electrophoresis-time-of-flight mass spectrometry detected 188 and 169 peaks in TK- and HKBML-derived cells, respectively, including suppression of central carbon metabolism, lipid metabolism, nucleic acid metabolism, urea cycle, branched chain and aromatic amino acids, and coenzyme metabolism. Particularly, whole suppressive metabolic pathways were demonstrated in TK-MTX, whereas HKBML-MTX indicated partially enhanced pathways of the urea cycle, amino acid metabolism, and coenzyme metabolism. Reciprocally detected metabolites for glycolysis, including induced glucose and reduced glycogen, and induced lactate and reduced pyruvate, in addition to increased lactate dehydrogenase activity, which is involved in Warburg effect. Thereby, ATP was increased in both methotrexate-resistant PCNSL-derived cells. Furthermore, we specifically found that PI3K/AKT/mTOR and RAS/MAPK signaling pathways were activated in TK-MTX but not in HKBML-MTX by growth rate with inhibitors and gene expression analysis, suggestive of cell type-specific methotrexate-resistant metabolic pathways. These results can help us understand targeted therapies with selective anticancer drugs in recurrent CNS lymphoma-acquired resistance against methotrexate.

Bifenthrin insecticide promotes oxidative stress and increases inflammatory mediators in human neuroblastoma cells through NF-kappaB pathway

The extensive application of bifenthrin (BF) insecticide in agriculture has raised serious concerns with regard to increased risks of developing neurodegenerative diseases. Recently, our group showed that BF exposure in rodent models induced oxidative stress and inflammation markers in various regions of the brain (frontal cortex, striatum and hippocampus) and this was associated with behavioral changes. This study aimed to confirm such inflammatory and oxidative stress in an in vitro cell culture model of SK-N-SH human neuroblastoma cells. Markers of oxidative stress (ROS, NO, MDA, H2O2), antioxidant enzyme activities (CAT, GPx, SOD) and inflammatory response (TNF-α, IL-6, PGE2) were analyzed in SK-N-SH cells after 24 h of exposure to different concentrations of BF (1–20 μM). Protein synthesis and mRNA expression of the enzymes implicated in the synthesis of PGE2 were also measured (COX-2, mPGES-1) as well as nuclear factor κappaB (NF-κBp65) and antioxidant nuclear erythroid-2 like factor-2 (Nrf-2). Cell viability was analyzed by MTT-tetrazolio (MTT) and lactate dehydrogenase (LDH) assays. Exposure of SK-N-SH cells to BF resulted in a concentration-dependent reduction in the number of viable cells (reduction of MTT and increase in LDH activity). There was also a BF concentration-dependent increase in oxidative stress markers (ROS release, NO, MDA and H2O2) and decrease in the activity of antioxidant enzymes (CAT and GPx activities). There was further a concentration-dependent increase in pro-inflammatory cytokines (TNF-α and IL-6) and inflammatory mediator PGE2, increase in protein synthesis and mRNA expression of inflammatory markers (COX-2, mPGES-1 and NF-κBp65) and decrease in protein synthesis and mRNA expression of antioxidant Nrf-2. Our data shows that BF induces various oxidative stress and inflammatory markers in SK-N-SH human neuroblastoma cells as well as the activation of NF-κBp65 signaling pathway. This is in line with prior results in brain regions of rodents exposed in vivo to BF showing increased oxidative stress in response to BF exposure, occurring in pro-inflammatory conditions and likely activating programmed cell death.

Влияние гепарина и этанола на активность лактатдегидрогеназы в митохондриальной и цитоплазматической фракциях клеток печени крыс

Experiments on rats have shown that ethanol at a dose of 4.5 g/kg leads to an increase in the activity of lactate dehydrogenase (LDH) in rat liver cells in a direct reaction in subcellular fractions. In the cytoplasmic fraction, the LDH activity in the reverse reaction decreased. Pre-administration of heparin to animals at a dose of 250 IU/kg partially neutralizes the effects of intraperitoneal administration of ethanol, which is expressed in a decrease in the activity of LDH in rat liver cells in a direct reaction in subcellular fractions. Binding of endogenous heparin to protamine sulfate and subsequent administration of ethanol leads to an increase in LDH activity in the mitochondrial fraction of rat liver cells.

Metabolic Adaptation of Airway Smooth Muscle Cells to an SPHK2 Substrate Precedes Cytostasis.

Thickening of the airway smooth muscle is central to bronchial hyperreactivity. We have shown that the sphingosine analog (R)-2-amino-4-(4-heptyloxyphenyl)-2-methylbutanol (AAL-R) can reverse preestablished airway hyperreactivity in a chronic asthma model. Because sphingosine analogs can be metabolized by SPHK2 (sphingosine kinase 2), we investigated whether this enzyme was required for AAL-R to perturb mechanisms sustaining airway smooth muscle cell proliferation. We found that AAL-R pretreatment reduced the capacity of live airway smooth muscle cells to use oxygen for oxidative phosphorylation and increased lactate dehydrogenase activity. We also determined that SPHK2 was upregulated in airway smooth muscle cells bearing the proliferation marker Ki67 relative to their Ki67-negative counterpart. Comparing different stromal cell subsets of the lung, we found that high SPHK2 concentrations were associated with the ability of AAL-R to inhibit metabolic activity assessed by conversion of the tetrazolium dye MTT. Knockdown or pharmacological inhibition of SPHK2 reversed the effect of AAL-R on MTT conversion, indicating the essential role for this kinase in the metabolic perturbations induced by sphingosine analogs. Our results support the hypothesis that increased SPHK2 levels in proliferating airway smooth muscle cells could be exploited to counteract airway smooth muscle thickening with synthetic substrates.

The silent information regulator 1 pathway attenuates ROS-induced oxidative stress in Alzheimer's disease

We show that down-regulation of circular ribonucleic acid 0001588 with small interfering-circular ribonucleic acid 0001588 mimics promoted caspase-3 and caspase-9 activity levels, increased lactate dehydrogenase activity levels, and reduced cell growth of in vitro model. Circular ribonucleic acid 0001588 plasmids increased circular ribonucleic acid 0001588 expressions and promoted cell growth and reduced activity levels of lactate dehydrogenase, caspase-3, and caspase-9 activity levels in vitro model of Alzheimer's disease. Then, circular ribonucleic acid 0001588 down-regulation also promoted reactive oxygen species production and oxidative stress (malonaldehyde), and reduced superoxide dismutase, glutathione, and glutathione peroxidase levels by suppressing of silent information regulator 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 in vitro. However, over-expression of circular ribonucleic acid 0001588 reduced reactive oxygen species production and malonaldehyde levels and increased superoxide dismutase, glutathione, and levels via activation signal pathway of silent information regulator 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway by miR-211-5p up-regulation in vitro. Over-expression of miR-211-5p attenuated the role of circular ribonucleic acid 0001588 on Alzheimer's disease-induced oxidative stress. Also, activation of the silent information regulator 1 pathway attenuated the antioxidative effects of circular ribonucleic acid 0001588 down-regulation on oxidative stress by activating silent information regulator 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 in vitro. In conclusion, our findings indicated that circular ribonucleic acid 0001588 induced the silent information regulator 1/nuclear factor erythroid 2-related factor 2-dependent heme oxygenase-1 pathway to prevent oxidative stress by miR-211-5p in the rat model or in vitro model of a sporadic type of Alzheimer's disease. Therefore, the expression of the circular ribonucleic acid 0001588 gene was inhibited in rodent Alzheimer's disease model.

Propylene Glycol Caprylate as a Novel Potential Absorption Enhancer for Improving the Intestinal Absorption of Insulin: Efficacy, Safety, and Absorption-Enhancing Mechanisms

Sodium caprate (C10) acts as an absorption enhancer. However, the absorption-enhancing effects of compounds with structures similar to C10 have not been characterized. In the present study, insulin was used as a model drug. We examined the effects of C10 and its related compounds on intestinal absorption of insulin using an in situ closed loop in rats. Insulin absorption was significantly enhanced by propylene glycol caprylate (Sefsol-218), a C10-related compound, after large intestinal administration. In addition, activity of lactate dehydrogenase did not increase in the intestinal epithelium in the presence of Sefsol-218 at concentrations equivalent to or lower than 1% (v/v). However, a significant increase in lactate dehydrogenase activity was observed in response to C10. These findings suggested that Sefsol-218 was safer than C10. Furthermore, mechanistic studies showed that increased membrane fluidity and loosening of tight junctions (TJs) might be underlying mechanisms by which this compound improved intestinal absorption of insulin. Furthermore, Sefsol-218 opened TJs by reducing the expression of claudin-4, which is a major TJ protein. These findings suggested that Sefsol-218 effectively enhanced intestinal insulin absorption without causing serious damage to the intestinal epithelium.

Seabream Larval Physiology under Ocean Warming and Acidification

The vulnerability of early fish stages represents a critical bottleneck for fish recruitment; therefore, it is essential to understand how climate change affects their physiology for more sustainable management of fisheries. Here, we investigated the effects of warming (OW; +4 °C) and acidification (OA; ΔpH = 0.5) on the heart and oxygen consumption rates, metabolic enzymatic machinery—namely citrate synthase (CS), lactate dehydrogenase (LDH), and ß-hydroxyacyl CoA dehydrogenase (HOAD), of seabream (Sparus aurata) larvae (fifteen days after hatch). Oxygen consumption and heart rates showed a significant increase with rising temperature, but decreased with pCO2. Results revealed a significant increase of LDH activity with OW and a significant decrease of the aerobic potential (CS and HOAD activity) of larvae with OA. In contrast, under OA, the activity levels of the enzyme LDH and the LDH:CS ratio indicated an enhancement of anaerobic pathways. Although such a short-term metabolic strategy may eventually sustain the basic costs of maintenance, it might not be adequate under the future chronic ocean conditions. Given that the potential for adaptation to new forthcoming conditions is yet experimentally unaccounted for this species, future research is essential to accurately predict the physiological performance of this commercially important species under future ocean conditions.

Evaluation of changes in the carbohydrate metabolism of Biomphalaria glabrata Say, 1818 exposed to experimental coinfection by Angiostrongylus cantonensis (Nematoda) and Echinostoma paraensei (Trematoda)

The interaction between intermediate snail hosts and helminths can cause metabolic changes in the former. The snails use their reserves for maintenance of their vital processes, by activating the internal defense system and repairing tissue damage, while also supplying necessary energy for the parasites’ development. Our aims were to evaluate the lactate dehydrogenase activity and the glucose concentration in the hemolymph of Biomphalaria glabrata experimentally coinfected by Angiostrongylus cantonensis and Echinostoma paraensei. Besides these aspects, the glycogen content in the digestive gland complex and cephalopedal mass along with histochemical changes in parasitized snails were analyzed. The snails were divided in group A (infected by 1200 L1 of A. cantonensis), group E (infected by 20 E. paraensei miracidia), group A + E (co-infected with A. cantonensis first and after a week by E. paraensei), group E + A (co-infected with E. paraensei first and then by A. cantonensis) and control group (not infected). During four weeks after exposure, samples were collected for biochemical and histochemical analyses. In the infected snails, glucose levels and glycogen content in the digestive gland complex and cephalopedal mass were significantly lower, in contrast with an increase of lactate dehydrogenase activity. These results indicate that the intense energy demand resulting from the presence of parasites causes the host snail to accelerate the anaerobic degradation of carbohydrates to obtain energy, in an attempt to maintain homeostasis. Both parasites were observed in histochemical analysis to cause tissue damages in the snails. So, although the snails were able to sustain the coinfection, several metabolic and tissue changes occurred, mainly in those infected with E. paraensei and then with A. cantonensis.

Underfilling of vacuum blood collection tubes leads to increased lactate dehydrogenase activity in serum and heparin plasma samples.

Background Lactate dehydrogenase (LD) activity is routinely monitored for therapeutic risk stratification of malignant diseases, but is also prone to preanalytical influences. Methods We systematically analyzed the impact of defined preanalytical conditions on the hemolysis-susceptible parameters LD, potassium (K) and hemolysis index in vacuum blood collection tubes (serum [SE], heparin plasma [HP]). Blood was collected by venipuncture from healthy volunteers. Tubes were either filled or underfilled to approximately 50%, then processed directly or stored at room temperature for 4 h. Potassium (K), sodium (Na), chloride (Cl), LD, creatine kinase (CK), total cholesterol, and indices for hemolysis, icterus, and lipemia were analyzed. Filling velocity was determined in a subset of tubes. Findings in healthy volunteers were reconfirmed in an in-patient cohort (n = 74,751) that was analyzed for plasma yield and LD data distribution. Results LD activity was higher in HP compared to SE. Underfilling led to higher LD values (SE: +21.6%; HP: +28.3%), K (SE: +4.2%; HP: +5.3%), and hemolysis index (SE: +260.8%; HP: +210.0%), while other analytes remained largely unchanged. Filling velocity of tubes was approximately 3-fold higher in the first half compared to the second half in both HP and SE collection tubes. Importantly, plasma yield also inversely correlated with LD in routine patients. By calculating reference limits, the lowest plasma yield quartile of the patient cohort displayed LD values clearly exceeding current reference recommendations. Conclusions Underfilling of tubes leads to a higher proportion of blood aspirated with high velocity and relevant elevations in LD. This finding should be considered in cases of clinically implausible elevated LD activities.

Metal nanoparticles-induced activation of NLRP3 inflammasome in human oral keratinocytes is a possible mechanism of oral lichenoid lesions

The NLRP3 inflammasome has been implicated in the pathogenesis of various inflammatory diseases and is activated by particulate stimulants. Oral epithelial keratinocytes are frequently exposed to metal nanoparticles. In this study, we examined the effects of gold, silver, and palladium nanoparticles, which are frequently used for dental metal alloys on cell proliferation, cytotoxicity, autophagy, lysosomal functions, and NLRP3 inflammasome activation using the immortalized human oral keratinocyte cell line RT-7. The metal nanoparticles were agglomerated in the membrane vesicles in RT-7 cells and suppressed cell proliferation and increased lactate dehydrogenase activity as well as the proportion of apoptotic cells. Silver and palladium nanoparticles induced autophagy and lysosomal dysfunctions and all metal nanoparticles tested triggered the secretion of IL-1β through caspase-1 activation. Furthermore, the epithelium obtained from patients with oral lichenoid lesions (OLLs) had robust NLRP3, ASC, caspase-1, and IL-1β-positive keratinocytes and cDNA microarray showed significant elevation in the mRNA levels of NLRP3. These results suggest that internalized metal nanoparticles in oral mucosal epithelial cells activate the NLRP3 inflammasome through the induction of lysosomal damage and autophagy dysfunction. This process may be involved in the pathogenesis of OLL and suggest its potential as an alternative target for OLL therapy.

Transcriptional profiling of zearalenone-induced inhibition of IPEC-J2 cell proliferation

Mounting evidence has shown that zearalenone (ZEA) can have toxic effects on the intestinal epithelial cells (IECs) of mammals and humans, but the mechanism of ZEA-induced toxicity on IECs is unclear. The aim of this study was to reveal the mechanism of action of ZEA on intestinal epithelial cells via RNA-seq technology. We measured the effects of ZEA on the viability and lactate dehydrogenase (LDH) activity of the pig intestinal epithelial cell line J2 (IPEC-J2). The results showed ZEA can decrease the IPEC-J2 cell viability and increase LDH activity. Appropriate treatment concentrations were determined (40 μM ZEA) to study the toxic effect of ZEA on IPEC-J2. The results showed that 40 μM ZEA significantly inhibited IPEC-J2 proliferation and arrested the cell cycle at the G2/M phase. A total of 783 differentially expressed genes (DEGs) were identified after ZEA treatment. KEGG pathway analysis revealed that PERK regulates gene expression, Toll-like receptor cascades signaling pathway, mitosis, mitotic metaphase and anaphase, DNA replication and G2/M checkpoints, were involved in the cell cycle pathway. Eleven key genes involved in G2/M checkpoints were validated by qPCR. Thus, these data highlighted that ZEA caused abnormalities in the G2/M transition in IPEC-J2 cells by altering the cell cycle signaling pathway, thereby inhibiting cell proliferation and inducing injury in IECs. And the study will contribute to get the molecular mechanisms of ZEA inhibition of IECs cell proliferation.

Bone mesenchymal stem cell-conditioned medium attenuates the effect of oxidative stress injury on NSCs by inhibiting the Notch1 signaling pathway.

Numerous studies have demonstrated the therapeutic effect of bone mesenchymal stem cells on spinal cord injury (SCI), especially on neural stem cells (NSCs). However, the predominant mechanisms of bone mesenchymal stem cells (BMSCs) are unclear. Recently, some researchers have found that paracrine signaling plays a key role in the therapeutic capacity of BMSCs and emphasized that the protective effect of BMSCs may be due to paracrine factors. In this study, we aimed to investigate the potential mechanisms of BMSCs to protect NSCs. NSCs were identified by immunocytochemistry. The oxidative stress environment was simulated by H2 O2 (50, 100, 200 μM) for 2 h. The apoptotic rate of the NSCs was detected via flow cytometry. Lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were evaluated via corresponding assay kits. Western blot was used to detect the expressions of Notch1, HES1, caspase-3, cleave caspase-3, Bax, and Bcl-2. We found that H2 O2 could significantly induce the apoptosis of NSCs, increase LDH, MDA levels, and decrease SOD activity by activating the Notch1 signaling pathway. DAPT (the specific blocker of Notch1) and BMSC-conditioned medium (BMSC-CM) could significantly prevent the apoptotic effect and oxidative stress injury on NSCs that were treated with H2 O2 . We also revealed that BMSC-CM could decrease the expression of Notch1, Hes1, cleave caspase-3, Bax, and increases the expression of Bcl-2 in NSCs, which was induced by H2 O2 . These results have revealed that BMSC-CM can neutralize the effect against oxidative stress injury on the apoptosis of NSCs by inhibiting the Notch1 signaling pathway.

Effect of long-term thermal challenge on the Antarctic notothenioid Notothenia rossii.

The thermal stability of the Antarctic Ocean raises questions concerning the metabolic plasticity of Antarctic notothenioids to changes in the environmental temperature. In this study, Notothenia rossii survived 90days at 8°C, and their condition factor level was maintained. However, their hepatosomatic (0.29×) index decreased, indicating a decrease in nutrient storage as a result of changes in the energy demands to support survival. At 8°C, the plasma calcium, magnesium, cholesterol, and triglyceride concentrations decreased, whereas the glucose (1.91×) and albumin (1.26×) concentrations increased. The main energy substrate of the fish changed from lipids to glucose due to a marked increase in lactate dehydrogenase activity, as demonstrated by an increase in anaerobic metabolism. Moreover, malate dehydrogenase activity increased in all tissues, suggesting that fish acclimated at 8°C exhibit enhanced gluconeogenesis. The aerobic demand increased only in the liver due to an increase (2.23×) in citrate synthase activity. Decreases in the activities of superoxide dismutase, catalase, and glutathione-S-transferase to levels that are most likely sufficient at 8°C were observed, establishing a new physiological activity range for antioxidant defense. Our findings indicate that N. rossii has some compensatory mechanisms that enabled its long-term survival at 8°C.

Chronic cadmium exposure in Japanese quails perturbs serum biochemical parameters and enzyme activity

Cadmium is a heavy metal, toxic even in trace amounts and its biological function in the human body has not been described to date. It is assumed that cadmium manifests in dose-dependent genotoxic and cytotoxic effects on many organs and tissue types. In this study, we have analyzed the biochemical parameters in the serum of Japanese quails (Coturnix japonica) after chronic in vivo exposure to cadmium. Adult animals were exposed to cadmium in the form of CdCl2 dissolved in water (0.20 mg/L) for 20 days. Significant differences between controls and exposed animals were found in 12 out of 13 analyzed biochemical parameters. Total bilirubin concentrations did not show any significant differences between the two groups. Exposure to cadmium has resulted in a significant increase in lactate dehydrogenase activity, sodium and chloride concentration, as well as significant reductions in total proteins, albumins, globulins, glucose, triglycerides, cholesterol, calcium concentration, and alkaline phosphatase activity. In this sense, chronic in vivo exposure to low doses of cadmium has induced severe changes in the levels of observed biochemical parameters and enzyme activity. Additionally, evident cytogenetic changes in the liver were also noted, where hepatocyte damage and even lack of organized nuclei, including nuclear fragmentation, clearly indicated ongoing apoptotic processes.

Therapeutic Potential of Dihydropyridine Calcium Channel Blockers on Oxidative Injury Caused by Organophosphates in Cortex and Cerebellum: An In Vivo Study.

This study was designed to investigate the effects of amlodipine (AM), a dihydropyridine calcium channel blocker, on the oxidative damage induced by diazinon (DZN) in the rat cortex and cerebellum. Forty-two rats were randomly divided into six groups. The rats were treated intraperitoneally with normal saline (group 1), AM (9mg/kg; group 2), DZN (32mg/kg; group 3) and different doses of AM (3, 6, and 9mg/kg; groups 4, 5, and 6, respectively) with DZN. After 14days, the cerebellum and cortex tissues were removed for biochemical and histological experiments. DZN significantly decreased acetylcholinesterase activity (AChE; 57%, p < 0.001 and 39.1%, p < 0.05), depleted total antioxidant capacity (TAC; 46.2%, p < 0.01 and 44.7%, p < 0.05), and increased lactate dehydrogenase activity (LDH; 96%, p < 0.001 and 202%, p < 0.001), nitric oxide (NO; 130%, p < 0.001 and 74.4%, p < 0.001), and lipid peroxidation levels (LPO; 35.6%, p < 0.001 and 128.7%, p < 0.001), in the cerebellum and cortex tissues, respectively. In addition, DZN induced structural alterations in the cerebellum and cortex. Following AM administration, a remarkable improvement was observed in LDH activity and some of the oxidative markers, such as NO and LPO; however, no significant changes were found in AChE activity when the DZN group was compared with the AM-treated groups. This study suggests that AM may prevent DZN-induced neurotoxicity via improvement of the oxidative/antioxidant balance in the cerebellum and cortex tissues.

PUFA supplementation may confer enhanced metabolic capacity in stimulated skeletal muscle cells

Skeletal muscle is an energetically demanding tissue that catabolizes a variety of different substrates, a phenomenon that is largely activity‐dependent. Lipids are an energetically‐rich macromolecule and, in this light, are advantageous for skeletal muscle performance and maintenance. It has long been established that lipids have dichotomous lasting effects on the body that appear to be, at least in part, species‐specific. While lipid‐related pathologies are largely associated with species such as saturated fatty acids, diacylglycerols, and ceramides, other lipid species, such as various unsaturated fatty acids, confer adaptive changes and may actually protect against diseases. Lipids have previously been linked to increased aerobic capacity in skeletal muscle, though the role of fatty acid quality in this context (e.g., degree of saturation) is less clear. In the present study, we used C2C12 cells, an immortalized line of mouse skeletal muscle cells, to better understand how polyunsaturated fatty acids (PUFAs), in combination with exercise, affect metabolism and protein concentration in skeletal muscle. Following standard proliferation protocols, mature myotubes were differentiated for 7 days in either control media or media supplemented with a 5% addition of linoleic acid (PUFA); additionally, to stimulate contractile activity, a subset of cell cohorts from each media group were exposed to caffeine for 20 minutes per day during differentiation days 4–7. All cells were harvested for protein on differentiation day seven. Protein concentration across cohorts was measured using a Bradford protein assay. Metabolic changes were characterized by running functional enzyme assays for lactate dehydrogenase (LDH) and citrate synthase (CS) to compare anaerobic and aerobic changes, respectively. Preliminary data show that non‐exercised cohorts have higher protein concentration when supplemented PUFA, and that exercise, both with and without PUFA supplementation, decreases protein concentration as compared to respective non‐exercised cohorts. Regarding enzyme activity, PUFA supplementation appears to decrease LDH activity in non‐exercised cells, while PUFA supplementation appears to increase LDH activity in exercised cells; CS activity also appears to change in PUFA supplemented cohorts. Collectively, these preliminary data suggest activity‐induced adaptive changes in skeletal muscle metabolism are contingent upon specific substrate availability, whereby PUFA availability may advantageously prime skeletal muscle for a higher overall metabolic capacity.Support or Funding InformationMcNair Scholars Program and The College of Saint ScholasticaThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Cancer metabolism in a snapshot: MRS(I).

The contribution of MRS(I) to the in vivo evaluation of cancer-metabolism-derived metrics, mostly since 2016, is reviewed here. Increased carbon consumption by tumour cells, which are highly glycolytic, is now being sampled by 13 C magnetic resonance spectroscopic imaging (MRSI) following the injection of hyperpolarized [1-13 C] pyruvate (Pyr). Hot-spots of, mostly, increased lactate dehydrogenase activity or flow between Pyr and lactate (Lac) have been seen with cancer progression in prostate (preclinical and in humans), brain and pancreas (both preclinical) tumours. Therapy response is usually signalled by decreased Lac/Pyr 13 C-labelled ratio with respect to untreated or non-responding tumour. For therapeutic agents inducing tumour hypoxia, the 13 C-labelled Lac/bicarbonate ratio may be a better metric than the Lac/Pyr ratio. 31 P MRSI may sample intracellular pH changes from brain tumours (acidification upon antiangiogenic treatment, basification at fast proliferation and relapse). The steady state tumour metabolome pattern is still in use for cancer evaluation. Metrics used for this range from quantification of single oncometabolites (such as 2-hydroxyglutarate in mutant IDH1 glial brain tumours) to selected metabolite ratios (such as total choline to N-acetylaspartate (plain ratio or CNI index)) or the whole 1 H MRSI(I) pattern through pattern recognition analysis. These approaches have been applied to address different questions such as tumour subtype definition, following/predicting the response to therapy or defining better resection or radiosurgery limits.

Increased lactate dehydrogenase activity is dispensable in squamous carcinoma cells of origin

Although numerous therapeutic strategies have attempted to target aerobic glycolysis to inhibit tumor progression, these approaches have not resulted in effective clinical outcomes. Murine squamous cell carcinoma (SCC) can be initiated by hair follicle stem cells (HFSCs). HFSCs utilize aerobic glycolysis, and the activity of lactate dehydrogenase (Ldh) is essential for HFSC activation. We sought to determine whether Ldh activity in SCC is critical for tumorigenesis or simply a marker of the cell type of origin. Genetic abrogation or induction of Ldh activity in HFSC-mediated tumorigenesis shows no effect on tumorigenesis as measured by number, time to formation, proliferation, volume, epithelial to mesenchymal transition, gene expression, or immune response. Ldha-null tumors show dramatically reduced levels of glycolytic metabolites by metabolomics, and significantly reduced glucose uptake by FDG-PET live animal imaging. These results suggest that squamous cancer cells of origin do not require increased glycolytic activity to generate cancers.

E-Cigarettes Increase Candida albicans Growth and Modulate its Interaction with Gingival Epithelial Cells.

Electronic cigarette (e-cigarette) vapor comes in contact with the different constituents of the oral cavity, including such microorganisms as Candida albicans. We examined the impact of e-cigarettes on C. albicans growth and expression of different virulent genes, such as secreted aspartic proteases (SAPs), and the effect of e-cigarette vapor-exposed C. albicans on gingival epithelial cell morphology, growth, and lactate dehydrogenase (LDH) activity. An increase in C. albicans growth was observed with nicotine-rich e-cigarettes compared with non-exposed cultures. Following exposure to e-cigarette vapor, C. albicans produced high levels of chitin. E-cigarettes also increased C. albicans hyphal length and the expression of SAP2, SAP3, and SAP9 genes. When in contact with gingival epithelial cells, e-cigarette-exposed C. albicans adhered better to epithelial cells than the control. Indirect contact between e-cigarette-exposed C. albicans and gingival epithelial cells led to epithelial cell differentiation, reduced cell growth, and increased LDH activity. Overall, results indicate that e-cigarettes may interact with C. albicans to promote their pathogenesis, which may increase the risk of oral candidiasis in e-cigarette users.

Primary Bone Lymphomas: Long-Term Results of a Prospective Single-Center Trial

Background. Primary bone lymphomas (PBL) are rare extranodal lymphomas. In more than 90 % of cases they are reported as diffuse large B-cell lymphomas (DLBCL). At local (IE) stage of PBL the standard R-CHOP immunotherapy demonstrates efficacy over 90 %. If, however, such poor prognostic factors (PPF) as multiple bone lesions (IVE stage), increased lactate dehydrogenase (LDH) activity, B-symptoms, and large tumor mass are identified, R-CHOP efficacy tends to decrease. There is currently no optimal regimen for treatment of PBL patients with PPF. We suggest intensified multiagent chemotherapy for this category of patients. Aim. To assess long-term results of prospective single-center trial on the use of high-dose mNHL-BFM-90 program in patients with primary bone DLBCL and PPF. Materials &amp; Methods. The trial included 33 patients with primary bone DLBCL followed-up at the National Medical Hematology Research Center from 2006 to 2018. The median age of patients was 44 years (range 16-78 years). The spectrum of assessed data included main clinical, laboratory, X-ray and MRI tumor characteristics as well as survival rates and prognostic factors. Results. PPF were identified in 29 (88 %) patients, out of them 20 (61 %) patients had an advanced stage (&gt; IE), 20 (59 %) patients showed an increased LDH activity, B-symptoms were identified in 15 (45 %) patients, and large tumor mass was reported in 23 (71 %) patients. High-dose antitumor treatment (mNHL-BFM-90) was administered in 27 out of 33 patients. Overall and progression-free survival within the period of 5 years was 92 %. None of PPF significantly influenced survival rates. Conclusion. The use of high-dose mNHL-BFM-90 program in PBL with poor prognosis achieves long-term remissions in 92 % patients. We recommend mNHL-BFM-90 as a therapy of choice for PBL patients with poor prognosis.