Energetic Pathways Research Articles

Exploring microbial diversity and functionality in Verdejo wine vinegar fermentation through LC-MS/MS analysis

The identification of microorganisms in vinegar production remains a challenge mainly, due to the difficulty of isolating and characterizing the microbiota involved. This implies that despite progress in understanding the composition and role of these microbial communities, there are still virtually unknown microorganisms in these environments. Metaproteomics reveals microbial diversity and behavior by analysis of proteins, offering precise insights into key moments and conditions in biological processes like acetification. This study consists of a thorough metaproteomic analysis during the elaboration of an innovative vinegar, Verdejo wine vinegar. Acetic acid fermentation occurred by submerged culture in an 8L automated Frings reactor operated in semi-continuous mode. LC-MS/MS identified 1626 proteins from 149 taxonomic groups, mainly Acetobacteraceae (1529), followed by yeast (47), lactic acid bacteria (29), and Archaea (21). Komagataeibacter (73.7%), Acetobacter (10.7%), Gluconacetobacter (1.7%), Novacetimonas (1.6%), and Gluconobacter (1.3%) were prevalent genera, with K. europaeus being the dominant species (56.7%). To our knowledge, this is the first metaproteomic approach to comprehensively address the study of so diverse microbial populations. GO Term analysis emphasized "heterocyclic compound binding" and "organic substance metabolic process", while analysis of protein-protein interactions identified key metabolic processes, such as amino acid biosynthesis, especially BCAAs, and crucial energetic pathways such as the TCA cycle. Stress response mechanisms, such as the dnaK-dnaJ-grpE and cl2p system, have been also highlighted. These analyses revealed the molecular and functional complexity of the acetification process, highlighting the critical importance of diverse metabolic routes in the adaptation of the microbiota members to the medium conditions. Overall, this study aims to characterize the microbiota driving Verdejo wine acetification and explore its composition, functions, and key metabolic processes.

Influence of captive breeding environment on the locomotor performance and metabolism of the threatened Alcatraz Snouted Treefrog, Ololygon alcatraz

AbstractEx situ conservation is a complementary strategy to in situ efforts and is vital for safeguarding endangered species through maintenance and breeding in captivity with potential for reintroductions into natural environments. However, it is crucial to recognize that prolonged captivity can lead to diminished abilities of organisms over generations. Factors linked to the impact of phenotypic plasticity during development, such as restricted movement, may affect organism performance during ex situ conservation efforts, potentially making reintroduction into the wild unfeasible. Consequently, it is imperative to analyze physiological differences between captive‐bred and wild individuals. Therefore, this study investigates how captivity influences locomotor performance, morphology, and metabolic capacities of adults and juveniles of the threatened treefrog Ololygon alcatraz, in comparison to natural populations. We obtained proportional measurements of individuals and assessed their locomotor performance through jumping exercise. We also measured the metabolic capacities of the frogs by examining the activity of enzymes involved in energetic metabolic pathways in their skeletal muscle fibers. We found that wild adult frogs had larger limbs, greater jumping abilities, and a more glycolytic profile, while captive adult frogs had smaller limbs and increased aerobic enzyme activity compared to their wild counterparts. These differences probably arise from phenotypic plasticity in ontogenetic development that differs between captive and natural environments, as juveniles do not show such differences. These results highlight the need for innovative strategies in managing captive O. alcatraz populations, which will aid in their successful translocation to the wild and strengthen ex situ conservation efforts.

Resistive Heating and Thermal Decomposition of an Additively Manufacturable Electrically Conductive Explosive

AbstractThe ability to transmit electrical signals through high explosive charges without using dense metal conductors could enable continuous monitoring of explosive charges with internally embedded sensors. With the sensor materials themselves being energetic, the impact on the intended detonation performance of the charge can be minimized. Embedded sensors enable real time, in‐situ measurements of conditions relevant to ageing assessments. Additionally, dynamic material property sensing can provide detonation performance data, enabling measurement of dynamic shock position. One proposed method to allow for electronic signal transfer through high explosives is to use electrically conductive explosive composites consisting of an electrically conductive polymer binder mixed with high explosive crystals. These conductive energetic pathways also serve as independently reactive elements and can provide additional functionality via dynamic sensor removal through resistive heating and subsequent decomposition. This work discusses the resistive heating of a previously developed, poly (3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based, electrically conductive extrudable explosive composite. Experimental samples of the conductive explosive material were subjected to a range of direct current applications and the resulting heating and decomposition of the material is discussed.

Metabolic profile in elite badminton match play and training drills.

Aim of the study was to analyze the metabolic profile of badminton matches and training drills. Therefore, 11 male (23.2±3.8years, 182±7cm, 74.4±8.4kg) and five female (19.3±1.5years, 170±6cm, 62.6±9.2kg) elite badminton players participated in either a training match (TM; n=7) and/or three protocols of multifeeding drills (T10, T30, T50; n=13), that varied in interval and rest durations (10s/10s, 30s/30s, 50s/50s). Absolute and relative energetic costs (Wtot and Etot) and contribution to oxidative (WOxid), phosphagen (WPCr), and anaerobic glycolytic (WLa) metabolism were calculated by the three-component PCr-La-O2-method based on an indirect calorimetric approach from oxygen consumption during exercise, post exercise, and net blood lactate concentration. A novel intermittent approach was used to consider replenishment of phosphocreatine during each resting phase. Results show that during TM, Etot was 676±98J·kg-1min-1, while metabolic pathways contributed by 56.9±8.6% (WOxid), 42.7±8.7% (WPCr), and 0.4±0.6% (WLa). In the multifeeding drills Etot was comparable between T10 (1020±160J·kg-1min-1) and T30 (985±173J·kg-1min-1) but higher in T50 (1266±194J·kg-1min-1) (p<0.001). Relative contribution of WOxid was lower in T10 (47.3±7.7%) but similar in T30 (56.5±6.2%) and T50 (57.3±6.0%) (p<0.001). WPCr was highest in T10 (51.1±8.3%) followed by T30 (42.2±6.9%) and lowest in T50 (31.2±7.7%) (p<0.001). WLa was similar between T10 (1.6±1.0%) and T30 (2.1±1.0%) but higher in T50 (11.6±4.8%) (p<0.001). Concludingly, metabolic costs in badminton are predominantly covered by oxidative and phosphagen energetic pathways. Metabolic profiles of the multifeeding drills differ depending on rally/interval duration, with increasing contribution of anaerobic glycolysis and decreasing phosphagen contribution in case of longer intervals.

Abstract Tu107: Decreased Mitochondrial Protein Expression Accompanies Atrial Hypertrophy but Precedes Atrial Fibrillation Onset in a Mouse Model of Spontaneous Atrial Fibrillation

Introduction: Atrial fibrillation (AF), characterized by episodes of rapid and irregular heart rate, increases left atrial (LA) demand for ATP. While the heart is metabolically flexible, able to use fatty acids, lactate, glucose, ketones, and amino acids to generate ATP, fatty acids are the primary fuel source. AF is associated with altered mitochondrial structure and function, but the role of energetic pathways in early stages of AF progression is not clear. Hypothesis: Decreased expression of mitochondrial proteins contributes to AF progression. Aim: Evaluate expression of proteins that influence mitochondrial structure and energetic capacity in AF onset and progression. Methods: AF burden was assessed weekly by electrocardiography (ECG) in male wild-type (WT) and cAMP responsive element modulator IbΔC-X heterozygous mice (CREM) (n=3). LA (4 - 9 mg) was obtained at 7 weeks and 16 weeks. Global proteomics was conducted, and 139,316 peptides were identified that mapped to 6000 robustly quantified proteins. Results: LA hypertrophy was evident in 7-week and 16-week CREM mice (Figure 1). We detected 2408 proteins differentially expressed in CREM compared to WT. At 7 weeks, Hallmark pathways adipogenesis, fatty acid metabolism, oxidative phosphorylation, and myogenesis were decreased in CREM (Table 1). These changes persisted at 16 weeks. We identified 740 differentially expressed mitochondrial proteins using MitoCarta 3.0 (552 decreased, 188 increased). Mitochondrial pathways associated with energy production, including branched chain amino acid metabolism, fatty acid transport and oxidation, carbohydrate metabolism, and tricarboxylic acid cycle were decreased (Table 1). Mitochondrial cristae organizing system (MICOS) and mitophagy, pathways that influence mitochondrial structure and content, were decreased. Terminal ECGs confirmed AF in 16-week CREM mice only. The coefficient of variation of RR intervals (CVRR), a measure of heart rate variability, was increased in 16-week CREM (Figure 2). These data suggest that decreased expression of mitochondrial proteins accompanies LA hypertrophy but precedes onset of AF. Conclusions: Decreased expression of proteins that regulate mitochondrial structure and energy production prior to AF onset suggests that these proteins play an important role in early LA changes that promote AF onset and progression. Future studies will examine how these changes in protein expression relate to alterations in atrial energy homeostasis.

Modulation of energetic and lipid pathways by curcumin as a potential chemopreventive strategy in human prostate cancer cells

In Western industrialized countries, prostate cancer (PCa) is the second most common malignant disease and prevalent cause of death for men. Epidemiological studies have shown that curcumin (CUR) either prevents PCa initiation or delays its progression to a more aggressive and treatment-refractory form, thus reducing related mortality. Our previous studies have proven the anticancer, antioxidant, and anti-inflammatory properties of CUR on PCa cells. However, there are few reports of the effect of CUR on energy and lipid pathways in PCa. Herein, we show that CUR can modulate the two metabolic energy pathways, increasing glycolytic reserve and reducing oxidative phosphorylation. Moreover, through the regulation of key enzymes and proteins, CUR affected the lipid pathway in PC-3 to a greater extent compared to the healthy PNT-2 cells. According to molecular docking investigations, the CUR activity in PCa may be mediated by the direct binding to the pyruvate dehydrogenase (PDHA1) enzyme, which is essential for regulating the appropriate mitochondrial activity. Taken together, our results shed light on the mechanism of action of CUR in the PCa cell metabolism and provide evidence of its potential value as an anticancer metabolic modulator, paving opportunities for novel therapeutic strategies.

Localized Pantothenic Acid (Vitamin B5) Reductions Present Throughout the Dementia with Lewy Bodies Brain.

Localized pantothenic acid deficiencies have been observed in several neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease dementia (PDD), and Huntington's disease (HD), indicating downstream energetic pathway perturbations. However, no studies have yet been performed to see whether such deficiencies occur across the dementia with Lewy bodies (DLB) brain, or what the pattern of such dysregulation may be. Firstly, this study aimed to quantify pantothenic acid levels across ten regions of the brain in order to determine the localization of any pantothenic acid dysregulation in DLB. Secondly, the localization of pantothenic acid alterations was compared to that previously in AD, PDD, and HD brains. Pantothenic acid levels were determined in 20 individuals with DLB and 19 controls by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) across ten brain regions. Case-control differences were determined by nonparametric Mann-Whitney U test, with the calculation of S-values, risk ratios, E-values, and effect sizes. The results were compared with those previously obtained in DLB, AD, and HD. Pantothenic acid levels were significantly decreased in six of the ten investigated brain regions: the pons, substantia nigra, motor cortex, middle temporal gyrus, primary visual cortex, and hippocampus. This level of pantothenic acid dysregulation is most similar to that of the AD brain, in which pantothenic acid is also decreased in the motor cortex, middle temporal gyrus, primary visual cortex, and hippocampus. DLB appears to differ from other neurodegenerative diseases in being the only of the four to not show pantothenic acid dysregulation in the cerebellum. Pantothenic acid deficiency appears to be a shared mechanism of several neurodegenerative diseases, although differences in the localization of this dysregulation may contribute to the differing clinical pathways observed in these conditions.

Geometric modeling of phase ordering for the isotropic–smectic A phase transition

BackgroundLiquid crystal (LC) mesophases have an orientational and positional order that can be found in both synthetic and biological materials. These orders are maintained until some parameter, mainly the temperature or concentration, is changed, inducing a phase transition. Among these transitions, a special sequence of mesophases has been observed, in which priority is given to the direct smectic liquid crystal transition. The description of these transitions is carried out using the Landau–de Gennes (LdG) model, which correlates the free energy of the system with the orientational and positional order.MethodologyThis work explored the direct isotropic-to-smectic A transition studying the free energy landscape constructed with the LdG model and its relation to three curve families: (I) level-set curves, steepest descent, and critical points; (II) lines of curvature (LOC) and geodesics, which are directly connected to the principal curvatures; and (III) the Casorati curvature and shape coefficient that describe the local surface geometries resemblance (sphere, cylinder, and saddle).ResultsThe experimental data on 12-cyanobiphenyl were used to study the three curve families. The presence of unstable nematic and metastable plastic crystal information was found to add information to the already developed smectic A phase diagram. The lines of curvature and geodesics were calculated and laid out on the energy landscape, which highlighted the energetic pathways connecting critical points. The Casorati curvature and shape coefficient were computed, and in addition to the previous family, they framed a geometric region that describes the phase transition zone.Conclusion and significanceA direct link between the energy landscape’s topological geometry, phase transitions, and relevant critical points was established. The shape coefficient delineates a stability zone in which the phase transition develops. The methodology significantly reduces the impact of unknown parametric data. Symmetry breaking with two order parameters (OPs) may lead to novel phase transformation kinetics and droplets with partially ordered surface structures.

Molecular Insights of Drug Resistance in Epilepsy: Multi-omics Unveil.

Epilepsy is a devastating neurological disorder mainly associated with impaired synchronic discharge that leads to sensory, motor, and psychomotor impairments. Till now, about 30 anti-seizure medications (ASMs) have been approved for the management of epilepsy, yet one-third of individuals still have uncontrollable epilepsy and develop resistance. Drug resistance epilepsy (DRE) is defined as the condition where two ASMs fail to control the seizure in epileptic patients. The leading cause of the resistance was the extended use of ASMs. According to various studies, alterations in some genes and their expressions, along with specific metabolic impairments, are suggested to be associated with ASMs resistance and DRE pathophysiology. Several factors aid in the pathophysiology of DRE, such as alterations in protein-encoding genes such as neurotransmitter receptors, drug transporters, ion channels, and drug targets. Furthermore, the altered metabolite levels of metabolites implicated in neurotransmitter signaling, energetic pathways, oxidative stress, and neuroinflammatory signaling differentiate the epileptic patient from the DRE patient. Various DRE biomarkers can be identified using the "integrated omics approach," which includes the study of genomics, transcriptomics, and metabolomics. The current review has been compiled to understand the pathophysiological mechanisms of DRE by focusing on genomics, transcriptomics, and metabolomics. An effort has also been made to identify the therapeutic targets based on identifying significant markers by a multi-omics approach. This has the potential to develop novel therapeutic interventions in the future.

Requirements on synthesis gas from gasification for material and energy utilization: a mini review

Achieving sustainable energy and material use mandates a critical focus on carbon recycling. The imperative for an efficient carbon cycle is paramount in sustainable energy systems and the chemical industry. Syngas, derived from waste and biomass gasification, offers a robust foundation for such recycling efforts. Various technologies, each with unique gas purity requirements, facilitate further refinement of syngas. This study provides a detailed and comparative analysis of the purity specifications necessary for both energetic and material utilization pathways.

Why Do Child Care Teachers Leave? Why Do They Stay? – Pre-Pandemic Evidence

ABSTRACT Turnover of child care staff is associated with lower care quality and compromised children’s development. While turnover rates in the child care sector have steadily been high, the COVID-19 pandemic has compounded the global staffing crisis. This article therefore aims to explore the correlates and reasons for turnover intention, turnover, and retention among child care teachers in two steps: The first study tested the Job Demands-Resources model using structural equation modeling. The second study assessed actual turnover and retention and explored the reasons for teachers staying and leaving in a smaller subsample 3 years later using correlational and content analyzes. Research Findings: The theoretical model fit the data well, indicating that job demands and job resources predict turnover intention mediated via job satisfaction and burnout. Overall, the motivational pathway was stronger than the energetic pathway. Furthermore, turnover intention predicted turnover 3 years later. The content analysis revealed that the team climate was a main reason for retention; leadership quality and a lack of advancement opportunities were crucial for job and occupational turnover. Practice or Policy: The results inform policy makers about measures to retain child care teachers and hence ensure care quality.

Insights into the Mechanism of Neptunium Oxidation to the Heptavalent State.

Neptunium can exist in multiple oxidation states, including the rare and poorly understood heptavalent form. In this work, we monitored the formation of heptavalent neptunium [Np(VII)O4(OH)2]3- during ozonolysis of aqueous MOH (M=Li, Na, K) solutions using a combined experimental and theoretical approach. All experimental reactions were closely monitored via absorption and vibrational spectroscopy to follow both the oxidation state and the speciation of neptunium guided by the calculated vibrational frequencies for various neptunium species. The mechanism of the reaction partly involves oxidative dissolution of transient Np(VI) oxide/hydroxide solid phases, the identity of which are dependent on the co-precipitating counter-cation Li+/Na+/K+. Additional calculations suggest that the most favorable energetic pathway occurs through the reaction of a [Np(V)O2(OH)4]3- with the hydroxide radical to form [Np(VI)O2(OH)4]2-, followed by an additional oxidation with HO⋅ to create [Np(VII)O4(OH)2]3-.

Assessment of the Potential of Sunflower Grown in Metal-Contaminated Soils for Production of Biofuels

Environmental biotechnology needs solutions that are associated with a low budget and cleaner remediation, and which are connected to resources and energetic valorization, to be able to encourage a circular bioeconomy. A prospective resolution for heavy-metal-contaminated soils is the application of phytoremediation approaches merged with bioenergy generation using the resulting biomass. Sunflower (Helianthus annuus) has been studied as a feedstock for biodiesel generation, and appears to be very attractive for biogas and bioethanol production. The current study reports an innovative energetic valorization approach of H. annuus biomass derived from the application of a phytoremediation strategy devised to remove Zn and Cd from an industrially contaminated soil (599 mg Zn kg−1 and 1.2 mg Cd kg−1)—and its comparison to the analysis of the same energetic valorization pathway for sunflower plants growing in an agricultural non-contaminated soil. After plant harvesting, bioethanol was produced from the aboveground tissues, and applied in the transesterification of the oil obtained through seed extraction for the generation of biodiesel. Also, biogas production was assessed through the root’s biomass anaerobic digestion. Similar yields of oil extraction—0.32 and 0.28 mL g−1 DW—were obtained when using seeds from H. annuus cultured in contaminated and non-contaminated soils, respectively. The production yield of bioethanol was superior using biomass from the agricultural non-contaminated soil (0.29 mL g−1 DW) when compared to the industrial metal-contaminated soil (0.20 mL g−1 DW). Zinc was measured in minor levels in bioethanol and oil (ca. 1.1 and 1.8 mg mL−1, correspondingly) resulting from the biomass cultivated in the industrialized soil, whereas Cd was not detected. The production yield of biogas was superior when using root biomass from H. annuus cultivated in agricultural non-contaminated soil (VS max. ca. 104 mL g−1) when compared to the one deriving from the industrial contaminated soil (VS max ca. 85 mL g−1). Generally, results demonstrate that substantial production yields of the tested biofuels were attained from biomass resulting from phytoremediation, corroborating this integrated original approach as a valuable alternative for the phytoremediation of HM-polluted soils and as an important strategy for plant biomass valorization.

Wildfire burn severity and stream chemistry influence aquatic invertebrate and riparian avian mercury exposure in forested ecosystems.

Terrestrial soils in forested landscapes represent some of the largest mercury (Hg) reserves globally. Wildfire can alter the storage and distribution of terrestrial-bound Hg via reemission to the atmosphere or mobilization in watersheds where it may become available for methylation and uptake into food webs. Using data associated with the 2007 Moonlight and Antelope Fires in California, we examined the long-term direct effects of wildfire burn severity on the distribution and magnitude of Hg concentrations in riparian food webs. Additionally, we quantified the cross-ecosystem transfer of Hg from aquatic invertebrate to riparian bird communities; and assessed the influence of biogeochemical, landscape variables, and ecological factors on Hg concentrations in aquatic and terrestrial food webs. Benthic macroinvertebrate methylmercury (MeHg) and riparian bird blood total mercury (THg) concentrations varied by 710- and 760-fold, respectively, and Hg concentrations were highest in predators. We found inconsistent relationships between Hg concentrations across and within taxa and guilds in response to stream chemical parameters and burn severity. Macroinvertebrate scraper MeHg concentrations were influenced by dissolved organic carbon (DOC); however, that relationship was moderated by burn severity (as burn severity increased the effect of DOC declined). Omnivorous bird Hg concentrations declined with increasing burn severity. Overall, taxa more linked to in situ energetic pathways may be more responsive to the biogeochemical processes that influence MeHg cycling. Remarkably, 8 years post-fire, we still observed evidence of burn severity influencing Hg concentrations within riparian food webs, illustrating its overarching role in altering the storage and redistribution of Hg and influencing biogeochemical processes.

Theoretical Study on the Mechanisms and Kinetics of Atmospheric Oxidation of Tetrafluoropropyne and Its Analogues.

Tetrafluoropropyne (C3F4) is a potential dielectric in various electrical insulating equipment to replace the most potent industrial greenhouse gas, sulfur hexafluoride. Atmospheric oxidation of C3F4 by OH radicals in the presence of molecular O2 has been investigated theoretically in order to clarify the lifetime and degradation products at mechanistic and kinetic aspects. Energetic minimum-energy pathways for the C3F4 + OH/O2 reactions were calculated in detail using various theoretical methods including density functional M06-2X and CCSD for geometries, CBS-QB3, CCSD(T), and multireference RS2 with extrapolation to the complete basis-set limit for energies. It has been demonstrated that the C3F4 + OH reaction takes place via the bifurcated C-O addition/elimination routes leading to CF3C(OH)═CF and CF3C═C(OH)F radical adducts, where the latter is more preferable in view of the difference in barrier heights (1.3 vs 0.3 kcal/mol), followed by H-migration, HF-elimination, and C-C and C-F bond fission. The atmospheric lifetime of C3F4 was estimated to be about 13 days, which is indicative of a very short-lived substance in the atmosphere. Further degradation of the energy-rich C3F4OH* intermediates by O2 takes place spontaneously in view of the successive barrier-free and highly exothermic pathways, producing a variety of fluorinated acids, anhydrides, biacetyls, and regenerating OH radicals. For comparison, the reactions of C3H4, CF3CCH, and CH3CCF with OH radicals were examined to clarify the F-substitution effect. It is revealed that the reactivity of fluoropropynes could be either reduced by CF3 or enhanced by atomic F attached to the acetylenic carbon. The present work provides a fundamental understanding of the reactions of fluoroalkynes with OH/O2. The use of C3F4 as a promising eco-friendly gaseous dielectric alternative to SF6 has been supported.

Targeted genetic therapies for inherited disorders that affect both cardiac and skeletal muscle.

Skeletal myopathies and ataxias with secondary cardiac involvement are complex, progressive and debilitating conditions. As life expectancy increases across these conditions, cardiac involvement often becomes more prominent. This highlights the need for targeted therapies that address these evolving cardiac pathologies. Musculopathies by and large lack cures that directly target the genetic basis of the diseases; however, as our understanding of the genetic causes of these conditions has evolved, it has become tractable to develop targeted therapies using biologics, to design precision approaches to target the primary genetic causes of these varied diseases. Using the examples of Duchenne muscular dystrophy, Friedreich ataxia and Pompe disease, we discuss how the genetic causes of such diseases derail diverse homeostatic, energetic and signalling pathways, which span multiple cellular systems in varied tissues across the body. We outline existing therapeutics and treatments in the context of emerging novel genetic approaches. We discuss the hurdles that the field must overcome to deliver targeted therapies across the many tissue types affected in primary myopathies.

Comparing Two Parameterizations for the Restratification Effect of Mesoscale Eddies in an Isopycnal Ocean Model

AbstractThere are two distinct parameterizations for the restratification effect of mesoscale eddies: the Greatbatch and Lamb (1990, GL90, https://journals.ametsoc.org/view/journals/phoc/20/10/1520-0485_1990_020_1634_opvmom_2_0_co_2.xml?tab_body=abstract-display) parameterization, which mixes horizontal momentum in the vertical, and the Gent and McWilliams (1990, GM90, https://journals.ametsoc.org/view/journals/phoc/20/1/1520-0485_1990_020_0150_imiocm_2_0_co_2.xml) parameterization, which flattens isopycnals adiabatically. Even though these two parameterizations are effectively equivalent under the assumption of quasi‐geostrophy, GL90 has been used much less than GM90, and exclusively in z‐coordinate models. In this paper, we compare the GL90 and GM90 parameterizations in an idealized isopycnal coordinate model, both from a theoretical and practical perspective. From a theoretical perspective, GL90 is more attractive than GM90 for isopycnal coordinate models because GL90 provides an interpretation that is fully consistent with thickness‐weighted isopycnal averaging, while GM90 cannot be entirely reconciled with any fully isopycnal averaging framework. From a practical perspective, the GL90 and GM90 parameterizations lead to extremely similar energy levels, flow and vertical structure, even though their energetic pathways are very different. The striking resemblance between the GL90 and GM90 simulations persists from non‐eddying through eddy‐permitting resolution. We conclude that GL90 is a promising alternative to GM90 for isopycnal coordinate models, where it is more consistent with theory, computationally more efficient, easier to implement, and numerically more stable. Assessing the applicability of GL90 in realistic global ocean simulations with hybrid coordinate schemes should be a priority for future work.

Abstract LB_B15: The antiproliferative activity of metformin in glioblastoma stem cells is mediated by the direct binding and functional inhibition of the membrane configuration of CLIC1 protein

Abstract Glioblastoma (GBM) is the deadliest brain tumor and represents a major clinical challenge. Even with the current standard of care and cutting-edge strategies, patients’ life expectancy remains invariably poor. Tumor heterogeneity and its extensive invasiveness make GBM difficult to be radically resected by neurosurgery and recurrence is common. There is scientific consensus that tumor relapse originates from progenitor/stem-like cells known as glioblastoma stem cells (GSCs). GSCs are endowed with distinct tumorigenic potential, with properties of self-renewal and multi-lineage differentiation that contribute to tumor mass heterogeneity. Thus, GSCs represent an appealing target for new therapies. In recent years, metformin's anti-cancer properties have been highlighted. Metformin administration to patients with type 2 diabetes (T2D) has been positively linked to a decrease in the risk of developing several cancers and in cancer-related mortality, including glioblastoma. Additionally, numerous studies on glioblastoma demonstrate that metformin’s anti-cancer properties are directed against GSCs. Despite this evidence, metformin’s mechanism of action on cancer cells has not been clarified, although it has been proposed to target the oxidative phosphorylation (OXPHOS) pathway. GSCs are able to shuttle between glycolysis and OXPHOS energetic pathways, and this metabolic plasticity could be the major reason for metformin’s low effectiveness in clinical trials so far. Chloride Intracellular Channel 1 (CLIC1) is a metamorphic protein that is predominantly cytoplasmic under physiological conditions. In response to persistent stress, it translocates to the plasma membrane, inducing chloride conductance. When GSCs are treated with metformin and agents that impair the activity of the transmembrane form of CLIC1 (tmCLIC1), they show a parallel and non-additive inhibition of proliferation. Our previous studies comprehensively demonstrated that tmCLIC1 contributes to the progression of GBM both in vitro and in vivo. In addition, its specific localization and enrichment at the GSC plasma membrane position tmCLIC1 as a prime pharmacological target for GBM treatment. Our investigation found that in vitro, metformin’s antiproliferative effect is exerted at a millimolar concentration range. However, in vivo, with metformin administered through drinking water, mice exhibit an increase in survival with brain levels of metformin quantified in the nanomolar range. It is possible that the constant fresh drug circulation, continuously reaching the brain during prolonged administration in vivo (up to 100 days) creates a drug steady state with persistent saturation and inhibition of all the active tmCLIC1 expressed by GBM cells. The need for lower concentrations in vivo than in vitro is also important to translate these studies into the clinic; the already-available extended-release formulation may provide the same sustained activity on GBM cells as the drug in mouse drinking water. Citation Format: Michele M Mazzanti, Francesca M Cianci. The antiproliferative activity of metformin in glioblastoma stem cells is mediated by the direct binding and functional inhibition of the membrane configuration of CLIC1 protein [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B15.

Abstract C057: Fibrolamellar carcinoma single-nucleus RNA sequencing reveals alteration of mitochondrial energetic pathways

Abstract Background: Fibrolamellar carcinoma (FLC) is a primary liver cancer, which arises in a background of normal liver. The DNAJB1-PRKACA (DP) fusion gene is present in the majority of FLC and is an oncogenic driver in animal models. The oncogenic mechanism of DP is unclear. To date, transcriptomic analyses of FLC have been based on bulk RNA sequencing. Given the lack of cell-specific data in bulk transcriptomic analysis, we hypothesize that using single nucleus RNA sequencing (snRNA-Seq) will allow for identification of significantly dysregulated signaling pathways specific to tumor cells. Methods: Single nuclei were isolated from 7 FLC tumors and 4 normal liver (NL). The Chromium Next GEM Single Cell 3’ Reagent Kit was used to generate sequencing libraries. All samples passing QC were submitted for sequencing by GeneWiz with a read depth of 20,000 reads/cell. An R-based pipeline for the single-cell profiling was built using Seurat R toolkit. Cells exhibiting extremely low or high library sizes, gene features outside the 95% confidence interval, or displaying high mitochondrial content were filtered out. Clusters from snRNA-Seq analysis were annotated using singleR, enrichR, and publicly available datasets. Results: FLC and NL nuclei counts were 98664 and 56644, respectively. We generated thirty one clusters and annotated 21 cell types. The FLC tumor group was annotated based on previously published FLC bulk transcriptomic data. We identified increased expression of SLC16A14, TMEM163, PDE10A, OAT, and GALNTL6 in FLC tumor cells. The predominant cells types and percentage of cells (%NL/%FLC) per group were: hepatocytes (43/57), endothelial cells (18/82), FLC tumor cells (15/85), stellate cells (28/72), Kupffer cells (50/50), cholangiocytes (62/38), Other 1 (22/78), T cells (36/64), and fibroblasts (69/31). FLC tissue contained only 3% of the liver sinusoidal endothelial cells. Comparison of FLC tumor cells demonstrated differential upregulation of 1879 and downregulation of 1579 genes in tumor vs. NL. Gene ontology (GO) enrichment identified the following top processes in FLC tumor cells: ATP metabolic process, cellular respiration, and response to peptide hormone. GO analysis of hepatocytes identified: ribonucleotide metabolic process, energy derivation by oxidation of organic compounds, and response to peptide hormone as significant pathways. Conclusions: FLC tumor cells demonstrate alterations in mitochondrial processes and energetics. FLC cells are known to contain abundant mitochondria, which is not observed in other primary liver epithelial cancers. The PRKACA component of DP fusion protein is the catalytic subunit of protein kinase A (PKA). Since PKA is known to regulate mitochondrial function, these data support the possibility that DP may directly alter mitochondrial function. Another interesting finding is the presence of the FLC tumor cell type in NL group (15%), which may suggest its dedifferentiation status or its cell-of-origin as a subpopulation of liver cells distinct from mature hepatocytes or cholangiocytes. Citation Format: Nihal Bharath, Biju Isaac, Marc S. Sherman, Colton J. Smith, Michael Karski, Liang Sun, Brian J. Pepe-Mooney, Ina Kycia, Michael Rogers, Wolfram Goessling, Khashayar Vakili. Fibrolamellar carcinoma single-nucleus RNA sequencing reveals alteration of mitochondrial energetic pathways [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C057.

Nickel-Tin Nanoalloy Supported ZnO Catalysts from Mixed-Metal Zeolitic Imidazolate Frameworks for Selective Conversion of Glycerol to 1,2-Propanediol.

The successful synthesis of finely tuned Ni1.5 Sn nanoalloy phases containing ZnO catalyst with a small particle size (6.7 nm) from a mixed-metal zeolitic imidazolate framework (MM-ZIF) is investigated. The catalyst was evaluated for the efficient production of 1,2-propanediol (1,2-PDO) from crude glycerol and comprehensively characterized using several analytical techniques. Among the catalysts, 3Ni1Sn/ZnO (Ni/Sn=3/1) showed the best catalytic performance and produced the highest yield (94.2 %) of 1,2-PDO at ~100 % conversion of glycerol; it also showed low apparent activation energy (15.4 kJ/mol) and excellent stability. The results demonstrated that the synergy between Ni-Sn alloy, finely dispersed Ni metallic sites, and the Lewis acidity of SnOx species-loaded ZnO played a pivotal role in the high activity and selectivity of the catalyst. The confirmation of acetol intermediate and theoretical calculations verify the Ni1.5 Sn phases provide the least energetic pathway for the formation of 1,2-PDO selectively. The reusability of solvent for successive ZIF synthesis, along with the excellent recyclability of the ZIF-derived catalyst, enables an overall sustainable process. We believe that the present synthetic protocol that uses MM-ZIF for the conversion of various biomass-derived platform chemicals into valuable products can be applied to various nanoalloy preparations.