Intracellular ATP Concentration Research Articles

FV-429 induces apoptosis by regulating nuclear translocation of PKM2 in pancreatic cancer cells

Of all malignancies, pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, has the worst prognosis. Glycolysis is overactive in PDAC patients and is associated with poor prognosis. Drugs that inhibit glycolysis as well as induce cell death need to be identified. However, glycolysis inhibitors often fail to induce cell death. We here found that FV-429, a derivative of the natural flavonoid wogonin, can induce mitochondrial apoptosis and inhibit glycolysis in PDAC in vivo and in vitro. In vitro, FV-429 inhibited intracellular ATP content, glucose uptake, and lactate generation, consequently leading to mitochondrial dysfunction and apoptosis in PDAC cells. Furthermore, it decreased the expression of PKM2 (a specific form of pyruvate kinase) through the ERK signaling pathway and enhanced PKM2 nuclear translocation. TEPP-46, the activator of PKM2, reversed FV-429-induced glycolysis inhibition and mitochondrial apoptosis in the PDAC cells. In addition, FV-429 exhibited significant tumor suppressor activity and high safety in BxPC-3 cell xenotransplantation models. These results thus demonstrated that FV-429 decreases PKM2 expression through the ERK signaling pathway and enhances PKM2 nuclear translocation, thereby resulting in glycolysis inhibition and mitochondrial apoptosis in PDAC in vitro and in vivo, which makes FV-429 a promising candidate for pancreatic cancer treatment.

Activity-based protein profiling technology reveals malate dehydrogenase as the target protein of cinnamaldehyde against Aspergillus niger

Cinnamaldehyde displays strong antifungal activity against fungi such as Aspergillus niger, but its precise molecular mechanisms of antifungal action remain inadequately understood. In this investigation, we applied chemoproteomics and bioinformatic analysis to unveil the target proteins of cinnamaldehyde in Aspergillus niger cells. Additionally, our study encompassed the examination of cinnamaldehyde's effects on cell membranes, mitochondrial malate dehydrogenase activity, and intracellular ATP levels in Aspergillus niger cells. Our findings suggest that malate dehydrogenase could potentially serve as an inhibitory target of cinnamaldehyde in Aspergillus niger cells. By disrupting the activity of malate dehydrogenase, cinnamaldehyde interferes with the mitochondrial tricarboxylic acid (TCA) cycle, leading to a significant decrease in intracellular ATP levels. Following treatment with cinnamaldehyde at a concentration of 1 MIC, the inhibition rate of MDH activity was 74.90 %, accompanied by an 84.5 % decrease in intracellular ATP content. Furthermore, cinnamaldehyde disrupts cell membrane integrity, resulting in the release of cellular contents and subsequent cell demise. This study endeavors to unveil the molecular-level antifungal mechanism of cinnamaldehyde via a chemoproteomics approach, thereby offering valuable insights for further development and utilization of cinnamaldehyde in preventing and mitigating food spoilage.

Abstract 7126: Synergistic combinations and tissue type-specificity of compounds targeting components of the DNA damage response pathway in 2D culture and 3D spheroid cell viability assays

Abstract Poly (ADP-ribose) polymerase (PARP) inhibitors have changed the landscape of treatment for homologous recombination (HR)-deficient cancers. PARP inhibitors are synthetically lethal with deficiencies in genes involved in the HR pathway, such as BRCA2, but resistance against PARP inhibitors is a major problem in the clinic. The use of new synergistic drug combinations targeting different components of the DNA damage response (DDR) pathway may overcome PARP inhibitor resistance. Sixteen small molecule inhibitors acting on different targets in the DDR pathway (including PARP, Polθ and ATR) were profiled in 2D culture and 3D spheroid cell viability assays. Intracellular ATP content was used as an indirect readout of cell number. Compound synergies were determined by profiling combinations of compounds in a 6-by-6 matrix, and quantifying synergistic effects using the Excess over Bliss score [1]. A pair of isogenic BRCA2-deficient and -proficient DLD-1 colon adenocarcinoma cell lines was used as a model of BRCA2-deficient tumors. In 2D cell viability assays, PARP inhibitors and the Polθ inhibitor ART558 were more active in BRCA2-deficient compared to BRCA2-proficient DLD-1 cells, whereas an ATR inhibitor (ceralasertib) was equally potent in both cell lines. Combining olaparib with ART558 in 2D culture and 3D spheroid studies showed synergistic effects in BRCA2-deficient DLD-1 cells. Moreover, olaparib synergized with ceralasertib in both BRCA2-deficient and -proficient DLD-1 cells. Different DDR-targeting inhibitors were profiled in over a hundred cancer cell lines from diverse tumor tissue origin in 2D assays. This showed a relatively high potency for PARP inhibitors in ovarian cancer cell lines compared to cell lines derived from other tissue types, which is consistent with the clinical application of PARP inhibitors for treatment of ovarian cancers. For ATR inhibitors and ART558, kidney and myeloid cancer cell lines were found to be most sensitive, respectively, suggesting potential therapeutic utility of ATR and Polθ inhibitors for treatment of these cancer types. The genomic determinants of the different sensitivities were investigated by comparing compound potencies in the cell viability assays with the mutation status of more than 500 genes involved in cancer or the DDR pathway in the cell lines. Additionally, cancer cell line sensitivity was correlated with the expression levels of more than 19,000 genes in these cell lines to identify novel RNA signatures capable of predicting response to DDR-targeting inhibitors. This study uncovers new synergistic drug combinations that increase the efficiency of PARP inhibitors, and provides new insights into the determinants of cancer cell line sensitivity to compounds targeting different components of the DDR pathway. [1] Liu et al. Stat. Biopharm. Res. 10, 112-22; 2018 Citation Format: Janneke J. Melis, Daphne J. Kluitmans, Jeffrey J. Kooijman, Jelle Dylus, Sabine Wetemans, Suzan Geerdink-Datema, Jeroen A. de Roos, Yvonne Grobben, Guido J. Zaman. Synergistic combinations and tissue type-specificity of compounds targeting components of the DNA damage response pathway in 2D culture and 3D spheroid cell viability assays [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7126.

Evaluation of the viability of the Bulgarian BCG vaccine by the adenosine triphosphate assay

We applied a modified assay for the measurement of the intracellular ATP content as an alternative biochemical method for estimating the viability of the BCG vaccine instead of the standard cultural microbiological assay. Eight lyophilized BCG ampoule samples (Lot 287-2 and Lot 254-2, Bulgarian BCG strain SL222 Sofia) were tested on different days. Each calibration curve was measured for the following range of ATP concentrations: 100, 10, 5, 2.5, 1.25, 0.625, 0.3125, and 0.1562 pmol. The obtained results were compared to the traditional cultural colony counting method for evaluating the viability of the BCG vaccine. The NCP of Lot 287-2 (min 2.325–max 3.300) was higher in comparison to Lot 254-2 (min 1.438–max 3.330). That result corresponded to higher ATP-content registered for Lot 287-2 (min 0.409–max 1.338) than Lot 254-2 (min 0.18–max 1.104). Our results confirmed the observation made by other researchers that the modified ATP assay is a reliable, simple, and quick method for the evaluation of the viability of the BCG vaccine. Additional compiled data about all BCG strains are needed to perform studies on the correlation between the luciferin-luciferase bioluminescent ATP assay and the cultural method for viability and enumeration of the units in the lyophilized BCG vaccine.

Synthesis, structure–activity relationship and biological evaluation of indole derivatives as anti-Candida albicans agents

In this work, we synthesized a series of indole derivatives to cope with the current increasing fungal infections caused by drug-resistant Candida albicans. All compounds were evaluated for antifungal activities against Candida albicans in vitro, and the structure–activity relationships (SARs) were analyzed. The results indicated that indole derivatives used either alone or in combination with fluconazole showed good activities against fluconazole-resistant Candida albicans. Further mechanisms studies demonstrated that compound 1 could inhibit yeast-to-hypha transition and biofilm formation of Candida albicans, increase the activity of the efflux pump, the damage of mitochondrial function, and the decrease of intracellular ATP content. In vivo studies, further proved the anti-Candida albicans activity of compound 1 by histological observation. Therefore, compound 1 could be considered as a novel antifungal agent.

Alpha-synuclein interaction with mitochondria is the final mechanism of ferroptotic death induced by erastin in SH-SY5Y cells

Ferroptosis has been characterized as a form of iron-dependent regulated cell death accompanied by an accumulation of reactive oxygen species and lipid oxidation products along with typical morphological alterations in mitochondria. Ferroptosis is activated by diverse triggers and inhibited by ferrostatin-1 and liproxstatin-1, apart from iron chelators and several antioxidants, and the process is implicated in multiple pathological conditions. There are, however, certain ambiguities about ferroptosis, especially regarding the final executioner of cell death subsequent to the accumulation of ROS. This study uses a typical inducer of ferroptosis such as erastin on SH-SY5Y cells, and shows clearly that ferroptotic death of cells is accompanied by the loss of mitochondrial membrane potential and intracellular ATP content along with an accumulation of oxidative stress markers. All these are prevented by ferrostatin-1 and liproxstatin-1. Additionally, cyclosporine A prevents mitochondrial alterations and cell death induced by erastin implying the crucial role of mitochondrial permeability transition pore (mPTP) activation in ferroptotic death. Furthermore, an accumulation of α-synuclein occurs during erastin induced ferroptosis which can be inhibited by ferrostatin-1 and liproxstatin-1. When the knock-down of α-synuclein expression is performed by specific siRNA treatment of SH-SY5Y cells, the mitochondrial impairment and ferroptotic death of the cells induced by erastin are markedly prevented. Thus, α-synuclein through the involvement of mPTP appears to be the key executioner protein of ferroptosis induced by erastin, but it needs to be verified if it is a generalized mechanism of ferroptosis by using other inducers and cell lines.

Importance of Intracellular Energy Status on High-Hydrostatic-Pressure Inactivation of sake Yeast Saccharomyces cerevisiae.

The HHP inactivation behaviors of Niigata sake yeast Saccharomyces cerevisiae strain S9arg and its aerobic respiratory-deficient mutant strains were investigated after cultivating them in a YPD media containing 2% to 15% glucose, as well as in moromi mash, in a laboratory-scale sake brewing process. The piezotolerance of strain S9arg, shown after cultivation in a YPD medium containing 2% glucose, decreased to become piezosensitive with increasing glucose concentrations in YPD media. In contrast, the piezosensitivity of a mutant strain UV1, shown after cultivation in the YPD medium containing 2% glucose, decreased to become piezotolerant with increasing glucose concentrations in the YPD medium. The intracellular ATP concentrations were analyzed for an S. cerevisiae strain with intact aerobic respiratory ability, as well as for strain UV1. The higher concentration of ATP after cultivation suggested a higher energy status and may be closely related to higher piezotolerance for the yeast strains. The decreased piezotolerance of strain S9arg observed after a laboratory-scale sake brewing test may be due to a lower energy status resulting from a high glucose concentration in moromi mash during the early period of brewing, as well as a lower aeration efficiency during the brewing process, compared with cultivation in a YPD medium containing 2% glucose.

The antibacterial activity and mechanism of a novel peptide MR-22 against multidrug-resistant Escherichia coli.

Bacterial infections have become serious threats to human health, and the excessive use of antibiotics has led to the emergence of multidrug-resistant (MDR) bacteria. E. coli is a human bacterial pathogen, which can cause severe infectious. Antimicrobial peptides are considered the most promising alternative to traditional antibiotics. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and hemolytic activity were determined by the microdilution method. The antimicrobial kinetics of MR-22 against E. coli were studied by growth curves and time-killing curves. The cytotoxicity of MR-22 was detected by the CCK-8 assay. The antimicrobial activity of MR-22 in salt, serum, heat and trypsin was determined by the microdilution method. The antimicrobial mechanism of MR-22 against drug-resistant E. coli was studied by Scanning Electron Microscope, laser confocal microscopy, and Flow Cytometry. The in vivo antibacterial activity of MR-22 was evaluated by the mice model of peritonitis. In this study, MR-22 is a new antimicrobial peptide with good activity that has demonstrated against MDR E. coli. The antimicrobial activity of MR-22 exhibited stability under conditions of high temperature, 10% FBS, and Ca2+. However, a decline of the activity was observed in the presence of Na+, serum, and trypsin. MR-22 had no significant cytotoxicity or hemolysis in vitro. SEM and fluorescent images revealed that MR-22 could disrupt the integrity of cell membrane. DCFH-DA indicated that MR-22 increased the content of reactive oxygen species, while it decreased the content of intracellular ATP. In mice model of peritonitis, MR-22 exhibited potent antibacterial activity in vivo. These results indicated that MR-22 is a potential drug candidate against drug-resistant E. coli.

Identification of polyphenol extracts from flaxseed and study on its bacteriostatic mechanism

In this paper, the polyphenol components of flaxseed were identified, and their antibacterial effect and mechanism of action against pathogenic bacteria were studied. Results showed that 14 phenolic acids and 15 flavonoids were identified in flaxseed. Among them, 5 phenolic acids, including ferulic acid, vanillic acid, sinapic acid, gallic acid, 4-hydroxybenzoic acid, as well as 6 flavonoids, including vitexin, quercitrin, quercetin, apigenin, kaempfero1, (+)-dihydroquercetin, were the main phenolic compounds in flaxseed and have been quantitatively analyzed and determined. The content of sinapic acid and quercetin accounted for over 42.67% of flaxseed polyphenol extract. The Oxford Cup method confirmed the antibacterial effect of flaxseed polyphenol extract on Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Salmonella and Pseudomonas fluorescens. The experimental data showed that flaxseed polyphenol extract had a strong inhibitory effect on the growth of both common food-borne pathogens and non-food-borne pathogens. Flaxseed polyphenols increased the permeability of microbial cell membrane, resulting in microbial protein leakage, cell membrane depolarization, and decreased intracellular ATP content, and increased cell membrane potential and cell contents leakage. The results of this study clarified the composition of flaxseed polyphenol and provided a new way for the comprehensive utilization of flaxseed.

Engineering yeast with a light-driven proton pump system in the vacuolar membrane

BackgroundThe supply of ATP is a limiting factor for cellular metabolism. Therefore, cell factories require a sufficient ATP supply to drive metabolism for efficient bioproduction. In the current study, a light-driven proton pump in the vacuolar membrane was constructed in yeast to reduce the ATP consumption required by V-ATPase to maintain the acidification of the vacuoles and increase the intracellular ATP supply for bioproduction.ResultsDelta rhodopsin (dR), a microbial light-driven proton-pumping rhodopsin from Haloterrigena turkmenica, was expressed and localized in the vacuolar membrane of Saccharomyces cerevisiae by conjugation with a vacuolar membrane-localized protein. Vacuoles with dR were isolated from S. cerevisiae, and the light-driven proton pumping activity was evaluated based on the pH change outside the vacuoles. A light-induced increase in the intracellular ATP content was observed in yeast harboring vacuoles with dR.ConclusionsYeast harboring the light-driven proton pump in the vacuolar membrane developed in this study are a potential optoenergetic cell factory suitable for various bioproduction applications.

Oleic Acid Activates Mitochondrial Energy Metabolism and Reduces Oxidative Stress Resistance in the Pancreatic β-Cell Line INS-1.

Elevated concentration of saturated fatty acids in plasma adversely affects pancreatic β-cells, but the effects of unsaturated fatty acids are controversial. In this study, we examined the effects of oleic acid (OA), a monounsaturated fatty acid, on mitochondrial function, which is important for insulin secretion, using INS-1 cells, a pancreatic β-cell line derived from rats. Observations of mitochondrial membrane potential and intracellular ATP concentration showed that the electron transport chain was enhanced and ATP production increased in cells treated with OA, indicating that the response that occurs from sensing an increase in glucose concentration to the production of ATP was accelerated. Measurements of intracellular reactive oxygen species (ROS) indicated that the rate of increase in ROS after glucose stimulation was significantly higher in OA-treated cells. The mRNA expression levels of superoxide dismutase 1 and 2, which are responsive to ROS and other substances, were significantly increased in OA 1-d treated cells, but decreased in OA 7-d treated cells. It can be inferred that continued exposure to high concentrations of OA reduced ROS processing capacity and increased intracellular ROS levels. The mRNA expression of apoptosis-inducing enzyme Caspase-3 was significantly increased in OA-treated cells, although its activity was not high. However, the apoptosis induction rate after H2O2 stimulation was significantly higher in OA-treated cells. The high OA environment was shown to promote mitochondrial energy metabolism, leading to an increase in glucose sensitivity and a decrease in oxidative stress resistance.

High Production of Nattokinase via Fed-Batch Fermentation of the γ-PGA-Deficient Strain of Bacillus licheniformis

During the production of nattokinase (NK) by Bacillus species, certain by-products such as poly-γ-glutamic acid (γ-PGA) are simultaneously synthesized. The impact of γ-PGA synthesis on NK production remains unclear. In this study, we knocked out the pgsC gene, a component of the γ-PGA synthetase cluster (pgsBCA), and constructed a novel recombinant strain, Bacillus licheniformis BL11. Next, we compared the fed-batch fermentation profiles of BL11 and its parental strain BL10, conducted transcriptional analysis, and measured intracellular ATP content. We also optimized glucose-feeding strategies under varying oxygen supply conditions. Our results indicated that the utilization rates of glucose and soybean meal were both improved in the pgsC-deficient strain BL11, and NK activity was enhanced. Furthermore, the transcriptional levels of genes involved in glycolysis and the TCA cycle were relatively upregulated in BL11. The maximal NK activity reached 2522.2 FU/mL at 54 h of fermentation using a constant glucose-feeding rate of 5.0 g/(L·h) under high oxygen supply conditions. The newly developed recombinant strain B. licheniformis BL11, along with the optimized feeding strategy, shows promise for large-scale NK production.

The Primary Mode of Action of Lippia graveolens Essential Oil on Salmonella enterica subsp. Enterica Serovar Typhimurium.

Essential oils are known to exhibit diverse antimicrobial properties, showing their value as a natural resource. Our work aimed to investigate the primary mode of action of Cuban Lippia graveolens (Kunth) essential oil (EO) against Salmonella enterica subsp. enterica serovar Typhimurium (S. enterica ser. Typhimurium). We assessed cell integrity through various assays, including time-kill bacteriolysis, loss of cell material with absorption at 260 and 280 nm, total protein leakage, and transmission electron microscopy (TEM). The impact of L. graveolens EO on membrane depolarization was monitored and levels of intracellular and extracellular ATP were measured by fluorescence intensity. The minimum inhibitory and bactericidal concentrations (MIC and MBC) of L. graveolens EO were 0.4 and 0.8 mg/mL, respectively. This EO exhibited notable bactericidal effects on treated cells within 15 min without lysis or leakage of cellular material. TEM showed distinct alterations in cellular ultrastructure, including membrane shrinkage and cytoplasmic content redistribution. We also observed disruption of the membrane potential along with reduced intracellular and extracellular ATP concentrations. These findings show that L. graveolens EO induces the death of S. enterica ser. Typhimurium, important information that can be used to combat this foodborne disease-causing agent.

PER2 regulates odontoblastic differentiation of dental papilla cells in vitro via intracellular ATP content and reactive oxygen species levels

Background Dental papilla cells (DPCs) are one of the key stem cells for tooth development, eventually forming dentin and pulp. Previous studies have reported that PER2 is expressed in a 24-hour oscillatory pattern in DPCs in vitro. In vivo, PER2 is highly expressed in odontoblasts (which are differentiated from DPCs). However, whether PER2 modulates the odontogenic differentiation of DPCs is uncertain. This research was to identify the function of PER2 in the odontogenic differentiation of DPCs and preliminarily explore its mechanisms. Methods We monitored the expression of PER2 in DPCs differentiated in vivo. We used PER2 overexpression and knockdown studies to assess the role of PER2 in DPC differentiation and performed intracellular ATP content and reactive oxygen species (ROS) assays to further investigate the mechanism. Results PER2 expression was considerably elevated throughout the odontoblastic differentiation of DPCs in vivo. Overexpressing Per2 boosted levels of odontogenic differentiation markers, such as dentin sialophosphoprotein (Dspp), dentin matrix protein 1 (Dmp1), and alkaline phosphatase (Alp), and enhanced mineralized nodule formation in DPCs. Conversely, the downregulation of Per2 inhibited the differentiation of DPCs. Additionally, downregulating Per2 further affected intracellular ATP content and ROS levels during DPC differentiation. Conclusion Overall, we demonstrated that PER2 positively regulates the odontogenic differentiation of DPCs, and the mechanism may be related to mitochondrial function as shown by intracellular ATP content and ROS levels.

Antimicrobial Activity and Mechanisms of Walnut Green Husk Extract.

Walnut green husks (WGHs), by-products of walnut production, are believed to possess antimicrobial properties, making them a potential alternative to antibiotics. In this study, the antibacterial activities of three extracts, derived from WGH, against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli were investigated, and the antibacterial mechanisms of an anhydrous ethanol extract of WGH (WGHa) were examined. The results showed that WGHa exhibited inhibitory effects on all tested bacteria. The ultrahigh-performance liquid chromatography-tandem mass spectrometry analysis revealed that the major active compounds present in WGHa were terpenoids, phenols, and flavonoids. Treatment with WGHa resulted in the leakage of intracellular ions and alkaline phosphatase; a reduction in intracellular ATP content, ATPase activity, and nucleic acid content; as well as cellular metabolic viability. The transmission electron microscopy images showed varying degrees of cell deformation and membrane damage following WGHa treatment. The transcriptome sequencing and differentially expressed gene enrichment analyses revealed an up-regulation in pathways associated with RNA degradation, translation, protein export, and oxidative phosphorylation. Conversely, pathways involved in cell movement and localization, as well as cell wall organization and carbohydrate transport, were found to be down-regulated. These findings suggest that WGHa alters cell membrane permeability and causes damage to the cell wall. Additionally, WGHa interferes with cellular energy metabolism, compromises RNA integrity, and induces DNA replication stress, consequently inhibiting the normal growth and proliferation of bacteria. These findings unveiled the antimicrobial mechanisms of WGHa, highlighting its potential application as an antibiotic alternative.

Abstract B061: Sensitivity and resistance mechanisms of human cancer cell lines treated with PARP, POLθ, and ATR inhibitor combinations in 2D and 3D spheroid cell viability assays

Abstract Poly ADP Ribose Polymerase (PARP) inhibitors have changed the landscape of treatment of homologous recombination (HR) -deficient cancers. The combination of PARP targeting agents and genetic alterations in the HR pathway is known to be synthetically lethal. Currently, four PARP inhibitors are approved for treatment of HR-deficient cancers. In combination with DNA damaging agents, PARP inhibitors synergistically kill tumor cells. Occurrence of resistance to PARP inhibitors is a major problem in the clinic. Targeting alternative DNA repair pathways or the use of new drug combinations may overcome PARP inhibitor resistance. We have determined and compared the effect of inhibitors of PARP, POLθ and ATR on cell viability in a large panel of human cancer cell lines (the Oncolines® panel) in 2D cell viability assays, using intracellular ATP content as an indirect read-out of cell number. The relationship between the mutation and expression status of genes involved in the DNA damage response pathway, or known to be involved in PARP inhibitor resistance, was determined. The effect of co-treatment of PARP inhibitors with inhibitors of POLθ, ATR and DNA damaging, cytotoxic agents was determined in BLISS combination matrix experiments in the colorectal adenocarcinoma cell line DLD1 and an isogenic BRCA2-deficient knock-out derivative. Drug combinations were studied in 2D and in 3D spheroid viability assays. To identify novel, potential mechanisms of resistance to PARP inhibitors, BRCA1-deficient ovarian UWB1.289 and BRCA2-deficient DLD1 cells were treated with sequentially increasing concentrations of PARP inhibitors talazoparib or olaparib. Resistant clones were selected and characterized. Our study reveals insight into the genetic determinants of cancer cell line sensitivity to inhibitors of PARP, POLθ and ATR. We also present the first side-by-side comparative study of the effect of drug combinations targeting the DNA damage response pathway in HR-deficient tumors in 2D and 3D spheroid cell viability assays. Citation Format: Janneke J.T.M. Melis, Jeffrey Kooijman, Sabine Wetemans, Suzan Geerdink-Datema, Jelle Dylus, Jeroen A.D.M. de Roos, Wilhelmina E. van Riel, Guido J.R. Zaman. Sensitivity and resistance mechanisms of human cancer cell lines treated with PARP, POLθ, and ATR inhibitor combinations in 2D and 3D spheroid cell viability assays [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 B061.

Probiotic-Derived Heptelidic Acid Demonstrates Therapeutic Efficacy Against Pediatric B-Cell Acute Lymphoblastic Leukemia

Introduction Pediatric B-cell acute lymphoblastic leukemia (B-ALL) is known to be sensitive to chemotherapy. However, approximately 15-20% of pediatric B-ALL patients experience relapse, and survival rates after relapse can drop to 5-10%. Therefore, new drugs need to be developed. Probiotics are live microorganisms with potential health benefits. Heptelidic acid (HA) from the probiotic Aspergillus oryzae has been shown to exert antitumor effects against pancreatic cancer, lung cancer, thyroid cancer, breast cancer and melanoma in vivo as well as in vitro. In this study, we assessed the antitumor effects of HA in B-ALL, which is the most common type of pediatric cancer. Methods Two B-ALL cell lines (JM1 and Reh), four CD34 + hematopoietic stem cells (HSCs) and three high-risk patient-derived B-ALL cells (s90: age < 1 year old, s96: age > 10 years old, s98: relapse) collected from the spleen or bone marrow of a patient-derived xenograft (PDX) model were used in this study. Cytotoxicity of HA was assessed by MTS assay. GAPDH activity and intracellular ATP contents were measured, as HA binds to cysteine 152 of GAPDH, a crucial region for its enzymatic activity and ATP production in glycolysis. The synergistic effects of HA with therapeutics, vincristine (VCR), doxorubicin (DXR) and L-asparaginase (L-Asp), were evaluated. GAPDH is involved not only in glucose metabolism but also in amino acid and fatty acids for energy production. Therefore, we analyzed whether HA exerted cytotoxicity under glucose, amino acid or fatty acid-deprived conditions in Reh cells. To analyze the underlying mechanism for HA's cytotoxicity against B-ALL, cell cycle analysis by flowcytometry, western blotting of cleaved PARP, caspase assays, and inhibitory assays using specific inhibitors for PCD mechanisms, such as RIPK-1 inhibitor, MLKL inhibitor, and autophagy inhibitor, were conducted. In vivo studies were done using a B-ALL PDX model. Oral administration of 0.5mg/kg HA was carried out for 21 days, while intraperitoneal injection of 0.15mg/kg VCR was performed once per week for 3 cycles in the HA-VCR combinational therapeutic efficacy study. Results HA exhibited significant cytotoxicity in JM1 (IC50: 169 ng/ml), Reh (IC50: 126.5 ng/ml), and three samples obtained from PDX mice (s90 IC50: 66.6 ng/ml, s96 IC50: 89.9 ng/ml, and s98 IC50: 275.6 ng/ml), while sparing CD34 + HSCs. GAPDH activity of CD34+ HSCs was significantly lower than both B-ALL cell lines and patient-derived cells. The cytotoxic effect of HA was associated with the reduction of GAPDH activity and ATP contents, suggesting glycolysis inhibition. Glucose deprivation induced significant reduction of cell viability, and HA showed the cytotoxicity in amino acid and fatty acid deprived media in Reh cells. Oral daily administration of HA prolonged the survival of the B-ALL PDX mice (34.5 days, n=8) compared to control mice (28 days, n=7) without causing body weight loss (p<0.05) (Figure 1A). The effects of over 0.5mg/kg of HA was confirmed by the reduction in GAPDH activity observed in leukemia cells isolated from the bone marrow. HA demonstrated synergistic effects when combined with chemotherapeutic agents, especially VCR. The combination therapy of HA and VCR resulted in improved survival outcomes in the B-ALL PDX model (49 days, n=5) compared to single-agent treatments (HA: 28 days, n=5, VCR: 40 days, n=5) and control groups (26 days, n=5) (p<0.05) (Figure 1B). Mechanistic studies revealed that HA induced PCD in B-ALL cells. HA treatment caused G2/M arrest (Control: 18.8%, HA: 27.6% in JM1; Control: 13.3%, HA: 18.3% in Reh), and this was accompanied by increased cleavage of PARP, a hallmark of PCD, in both cell lines. Moreover, the cytotoxicity of HA was attenuated by RIPK1 inhibition in JM1 and Reh. Conclusion We have demonstrated that B-ALL cells utilize glucose for their survival and HA is cytotoxic in B-ALL cells by disrupting glycolysis through the inhibition of GAPDH. The therapeutic efficacy of HA is further enhanced when combined with chemotherapeutic agents. The underlying mechanisms of HA involve the induction of RIPK-1 mediated PCD. This is the first study to demonstrate HA as a novel therapeutic agent for B-ALL.

Exploring the metabolic and antioxidant potential of solergy: Implications for enhanced animal production

Cell models are indispensable tools in biotechnology when investigating the functional properties of organic compounds. The emergence of various additives designed to enhance animal production has introduced the need for in-depth evaluations, which are often hindered by the complexities of in vivo testing. In this study, we harnessed cell-based models to scrutinize the impact of Solergy as a regulator of cellular metabolism with a particular focus on its modulation of glycogen and antioxidant effects. Our experiment was designed to include assessments of the influence of Solergy on the viability of both terrestrial and aquatic vertebrate cell models, which revealed the benign nature of Solergy and its lack of adverse effects. Furthermore, we examined the capacity of Solergy to modulate intracellular ATP concentrations and enhance glycogen accumulation. Notably, the antioxidant potential of Solergy and its ability to mitigate cellular aging were evaluated within the same cellular frameworks. The outcomes of our investigation suggest that Solergy is a potent metabolic regulator that elevates cellular activity while exerting an antioxidant effect. Importantly, our study demonstrates that Solergy does not induce changes in membrane oxidation. These findings indicate the potential of using Solergy to regulate glycogen synthesis, intracellular ATP concentrations, and oxidative stress in production animals. The multifaceted effects of this additive, which acts as both a metabolism enhancer and an antioxidant, open doors to the creation of custom diets tailored to meet specific production needs while maintaining stable production parameters.

PSIII-4 Effect of Photobiomodulation Treatment on Atp Concentrations in Bovine Oocytes During Maturation

Abstract Oocyte cytoplasmic maturation is critical in determining the success of subsequent embryo development. It has been proposed that light in the red-to-near infrared optical region (~600–1000 nm) enhances cellular metabolic activity through activation of the mitochondrial respiratory chain, increasing intracellular ATP concentrations, and has the potential to modify the oocyte metabolome. Previous research indicated a greater cleavage rate and similar blastocyst rates for bovine oocytes treated with photobiomodulation at hours 16 and 20 from the start of maturation compared with control. For the present study, two separate experiments were conducted to determine ATP concentration in oocytes during maturation after photobiomodulation treatment. A standardized in vitro maturation (IVM) protocol and commercial media (IVF Bioscience) were used. Briefly, bovine ovaries were obtained at a local slaughterhouse, cumulus oocyte complexes (COCs) were collected by aspiration of small (2 to 6 mm) follicles. For experiment 1, compact COCs were cultured in in vitro maturation media (n = 30/well) and treated with no light (control); light (660-665nm) for 10 minutes at hour 16 from start of maturation (L-16) and light for 10 minutes at hour 20 from the start of maturation (L-20). At hour 24 of in vitro maturation, COCs were vortexed to remove cumulus, stained with BioTracker ATP-Red Live Cell Dye (Sigma-Aldrich SCT045), imaged with Cytation-1 (Agilent Technologies Inc.) in 6 replicates. For experiment 2, COCs were cultured in in vitro maturation media (n = 40/well) and treated with no light (control) and light (660-665nm) for 10 minutes at hour 16 from start of maturation (L-16). At hours 18, 20, 22 and 24 of in vitro maturation, COCs were vortexed to remove cumulus, stained with BioTracker ATP-Red Live Cell Dye, and imaged with Cytation-1 in 4 replicates. For experiment 1, one-way ANOVA and Student’s T-Test were performed (JMP software 16.0); in experiment 2, each well was considered as an experimental unit in a model of repeated measures, main effects of time and treatment, blocked by replicate (Mixed procedure, SAS Institute Inc.). In experiment 1, there was a significant (P < 0.05) effect of treatment; ATP concentrations were greater in L-16 than control, and L-20 was intermediate. ATP concentrations were 19,579.3a ± 596.5, 21,652.0b ± 602.7 and 19,710.9ab ± 570.6 relative fluorescence units (RFU) for control, L-16, and L-20 respectively. In experiment 2, there was a significant (P < 0.05) effect of treatment and no significant effect of time. Overall ATP concentrations were 25,668 ± 894.6 and 28,332 ± 894.6 RFU for control and L-16 respectively. In conclusion, photobiomodulation treatment with LED 660-665nm for 10 minutes at hour 16 from start of oocyte maturation increases intracellular ATP concentrations from hour 18 to 24 of maturation.

Senescent Endothelial Cells Sustain Their Senescence-Associated Secretory Phenotype (SASP) through Enhanced Fatty Acid Oxidation.

Cellular senescence is closely linked to endothelial dysfunction, a key factor in age-related vascular diseases. Senescent endothelial cells exhibit a proinflammatory phenotype known as SASP, leading to chronic inflammation (inflammaging) and vascular impairments. Albeit in a state of permanent growth arrest, senescent cells paradoxically display a high metabolic activity. The relationship between metabolism and inflammation is complex and varies across cell types and senescence inductions. While some cell types shift towards glycolysis during senescence, others favor oxidative phosphorylation (OXPHOS). Despite the high availability of oxygen, quiescent endothelial cells (ECs) tend to rely on glycolysis for their bioenergetic needs. However, there are limited data on the metabolic behavior of senescent ECs. Here, we characterized the metabolic profiles of young and senescent human umbilical vein endothelial cells (HUVECs) to establish a possible link between the metabolic status and the proinflammatory phenotype of senescent ECs. Senescent ECs internalize a smaller amount of glucose, have a lower glycolytic rate, and produce/release less lactate than younger cells. On the other hand, an increased fatty acid oxidation activity was observed in senescent HUVECs, together with a greater intracellular content of ATP. Interestingly, blockade of glycolysis with 2-deoxy-D-glucose in young cells resulted in enhanced production of proinflammatory cytokines, while the inhibition of carnitine palmitoyltransferase 1 (CPT1), a key rate-limiting enzyme of fatty acid oxidation, ameliorated the SASP in senescent ECs. In summary, metabolic changes in senescent ECs are complex, and this research seeks to uncover potential strategies for modulating these metabolic pathways to influence the SASP.