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International Journal of Molecular... Jul 2023In previous work, we showed that cancer cells do not depend on glycolysis for ATP production, but they do on fatty acid oxidation. However, we found some cancer cells...
In previous work, we showed that cancer cells do not depend on glycolysis for ATP production, but they do on fatty acid oxidation. However, we found some cancer cells induced cell death after glucose deprivation along with a decrease of ATP production. We investigated the different response of glucose deprivation with two types of cancer cells including glucose insensitive cancer cells (GIC) which do not change ATP levels, and glucose sensitive cancer cells (GSC) which decrease ATP production in 24 h. Glucose deprivation-induced cell death in GSC by more than twofold after 12 h and by up to tenfold after 24 h accompanied by decreased ATP production to compare to the control (cultured in glucose). Glucose deprivation decreased the levels of metabolic intermediates of the pentose phosphate pathway (PPP) and the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) in both GSC and GIC. However, glucose deprivation increased reactive oxygen species (ROS) only in GSC, suggesting that GIC have a higher tolerance for decreased NADPH than GSC. The twofold higher ratio of reduced/oxidized glutathione (GSH/GSSG) in GIS than in GSC correlates closely with the twofold lower ROS levels under glucose starvation conditions. Treatment with N-acetylcysteine (NAC) as a precursor to the biologic antioxidant glutathione restored ATP production by 70% and reversed cell death caused by glucose deprivation in GSC. The present findings suggest that glucose deprivation-induced cancer cell death is not caused by decreased ATP levels, but rather triggered by a failure of ROS regulation by the antioxidant system. Conclusion is clear that glucose deprivation-induced cell death is independent from ATP depletion-induced cell death.
Topics: Glucose; Adenosine Triphosphate; Pentose Phosphate Pathway; Reactive Oxygen Species; NADP; Glutathione; Acetylcysteine; PC-3 Cells; Humans; Neoplasms; Cell Death
PubMed: 37569345
DOI: 10.3390/ijms241511969 -
Redox Biology Sep 2023Exposure to ionizing radiation leads to oxidative damages in living cells. NADPH provides the indispensable reducing power to regenerate the reduced glutathione to...
Exposure to ionizing radiation leads to oxidative damages in living cells. NADPH provides the indispensable reducing power to regenerate the reduced glutathione to maintain cellular redox equilibria. In mammalian cells, pentose phosphate pathway (PPP) is the major route to produce NADPH by using glycolytic intermediates, and the rate-limiting step of PPP is controlled by glucose-6-phosphate dehydrogenase (G6PD). Nevertheless, whether G6PD is timely co-opted under ionizing radiation to cope with oxidative stress remains elusive. Here we show that cellular G6PD activity is induced 30 min after ionizing radiation, while its protein expression is mostly unchanged. Mechanistically, casein kinase 2 (CK2) phosphorylates G6PD T145 under ionizing radiation, which consolidates the enzymatic activity of G6PD by facilitating G6PD binding with its substrate NADP. Further, CK2-dependent G6PD T145 phosphorylation promotes NADPH production, decreases ROS level and supports cell proliferation under ionizing radiation. Our findings report a new anti-oxidative signaling route under ionizing radiation, by which CK2-mediated rapid activation of G6PD orchestrates NADPH synthesis to maintain redox homeostasis, thereby highlighting its potential value in the early treatment of ionizing radiation-induced injuries.
Topics: Animals; Glucosephosphate Dehydrogenase; Casein Kinase II; NADP; Phosphorylation; Oxidation-Reduction; Radiation, Ionizing; Homeostasis; Pentose Phosphate Pathway; Mammals
PubMed: 37478541
DOI: 10.1016/j.redox.2023.102810 -
International Journal of Molecular... Dec 2023Blueberry is a high-quality fruit tree with significant nutritional and economic value, but the intricate mechanism of sugar accumulation in its fruit remains unclear....
Blueberry is a high-quality fruit tree with significant nutritional and economic value, but the intricate mechanism of sugar accumulation in its fruit remains unclear. In this study, the ripe fruits of blueberry cultivars 'Anna' and 'Misty' were utilized as experimental materials, and physiological and multi-omics methodologies were applied to analyze the regulatory mechanisms of the difference in sugar content between them. The results demonstrated that the 'Anna' fruit was smaller and had less hardness than the 'Misty' fruit, as well as higher sugar content, antioxidant capability, and lower active substance content. A total of 7067 differentially expressed genes (DEGs) (3674 up-regulated and 3393 down-regulated) and 140 differentially abundant metabolites (DAMs) (82 up-regulated and 58 down-regulated) were identified between the fruits of the two cultivars. According to KEGG analysis, DEGs were primarily abundant in phenylpropanoid synthesis and hormone signal transduction pathways, whereas DAMs were primarily enriched in ascorbate and aldarate metabolism, phenylpropanoid biosynthesis, and the pentose phosphate pathway. A combined multi-omics study showed that 116 DEGs and 3 DAMs in starch and sucrose metabolism (48 DEGs and 1 DAM), glycolysis and gluconeogenesis (54 DEGs and 1 DAM), and the pentose phosphate pathway (14 DEGs and 1 DAM) were significantly enriched. These findings suggest that blueberries predominantly increase sugar accumulation by activating carbon metabolism network pathways. Moreover, we identified critical transcription factors linked to the sugar response. This study presents new understandings regarding the molecular mechanisms underlying blueberry sugar accumulation and will be helpful in improving blueberry fruit quality through breeding.
Topics: Blueberry Plants; Plant Breeding; Gene Expression Profiling; Pentose Phosphate Pathway; Lamiales; Sugars
PubMed: 38203463
DOI: 10.3390/ijms25010293 -
Journal of the National Cancer Institute Jul 2023Poly (ADP-ribose) polymerase inhibitors (PARPi) have revolutionized the treatment of ovarian cancer; however, real-world data on kidney function among patients treated...
BACKGROUND
Poly (ADP-ribose) polymerase inhibitors (PARPi) have revolutionized the treatment of ovarian cancer; however, real-world data on kidney function among patients treated with PARPi are lacking.
METHODS
We identified adults treated with olaparib or niraparib between 2015 and 2021 at a major cancer center in Boston, MA, USA. We determined the incidence of any acute kidney injury (AKI), defined as at least a 1.5-fold rise in serum creatinine from baseline in the first 12 months following PARPi initiation. We calculated the percentage of patients with any AKI and sustained AKI and adjudicated the etiologies by manual chart review. We compared trajectories in estimated glomerular filtration rate (eGFR) among PARPi-treated and carboplatin and paclitaxel-treated patients with ovarian cancer, matched by baseline eGFR.
RESULTS
Of 269 patients, 60 (22.3%) developed AKI, including 43 of 194 (22.1%) olaparib-treated patients and 17 of 75 (22.7%) niraparib-treated patients. Only 9 of 269 (3.3%) had AKI attributable to the PARPi. Of the 60 patients with AKI, 21 (35%) had sustained AKI, of whom 6 had AKI attributable to the PARPi (2.2% of the whole cohort). eGFR declined within 30 days post-PARPi initiation by 9.61 (SD = 11.017) mL/min per 1.73 m2 but recovered by 8.39 (SD = 14.05) mL/min per 1.73 m2 within 90 days after therapy cessation. There was no difference in eGFR at 12 months post-therapy initiation in patients receiving PARPi or controls receiving carboplatin and paclitaxel (P = .29).
CONCLUSIONS
AKI is common following PARPi initiation as is a transient decline in eGFR; however, sustained AKI directly attributable to the PARPi and long-term eGFR decline are uncommon.
Topics: Humans; Female; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Ribose; Carboplatin; Ovarian Neoplasms; Paclitaxel; Acute Kidney Injury; Kidney
PubMed: 37074956
DOI: 10.1093/jnci/djad070 -
Molecular Metabolism Dec 2023Tumor cells hijack inflammatory mechanisms to promote their own growth. IL-6 is one of the major cytokines, and is frequently upregulated in tumors. The pentose...
OBJECTIVE
Tumor cells hijack inflammatory mechanisms to promote their own growth. IL-6 is one of the major cytokines, and is frequently upregulated in tumors. The pentose phosphate pathway (PPP) generates the indispensable building blocks to produce various nucleotides. Here we aimed to determine whether and how PPP is timely tuned in response to IL-6 to support tumor growth.
METHODS
Protein expression was examined by immunoblot. Protein interaction was examined by immunoprecipitation. Tumor cell proliferation in in vitro culture was examined by BrdU assay and colony formation assay. Tumor cell proliferation in mouse xenograft model was examined by Ki-67 staining.
RESULTS
Here we show that the metabolic flux of PPP and enzymatic activity of glucose-6-phosphate dehydrogenase (G6PD) is rapidly induced under IL-6 treatment, without obvious changes in G6PD expression level. Mechanistically, Janus kinase 2 (JAK2) phosphorylates G6PD Y437 under IL-6 treatment, which accentuates G6PD enzymatic activity by promoting G6PD binding with its substrate G6P. Further, JAK2-dependent G6PD Y437 phosphorylation is required for IL-6-induced nucleotide biosynthesis and tumor cell proliferation, and is associated with the progression of oral squamous cell carcinoma.
CONCLUSIONS
Our findings report a new mechanism implicated in the crosstalk between tumor cells and inflammatory microenvironment, by which JAK2-dependent activation of G6PD governs nucleotide synthesis to support tumor cell proliferation, thereby highlighting its value as a potential anti-tumor target.
Topics: Humans; Mice; Animals; Phosphorylation; Oxidoreductases; Interleukin-6; Janus Kinase 2; Glucose 1-Dehydrogenase; Carcinoma, Squamous Cell; Phosphates; Mouth Neoplasms; Nucleotides; Tumor Microenvironment
PubMed: 37949355
DOI: 10.1016/j.molmet.2023.101836 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Mar 2024The utilization of industrial microorganisms for the conversion of lignocellulose into high value-added chemicals is an essential pathway towards achieving carbon...
The utilization of industrial microorganisms for the conversion of lignocellulose into high value-added chemicals is an essential pathway towards achieving carbon neutrality and promoting sustainable bioeconomy. However, the pretreated lignocellulase hydrolysate often contains various sugars, salts, phenols/aldehydes and other substances, which requires microorganisms to possess strong tolerance for direct fermentation. This study aims to investigate the tolerance of to substrate, salt, and high temperature shock, in order to validate its potential for utilizing the enzymatic hydrolysate of in seawater for fermentation. The experimental results showed that the adaptively domesticated . exhibited tolerance to glucose at a concentration of 200 g/L and became a hypertonic strain. When seawater was used instead of freshwater without sterilization, the yield of glycerol in fermentation was 109% higher than that in freshwater with sterilization. Moreover, the combined thermal shock at 32 hours of fermentation and addition of 10 NaSO at 48 hours resulted in a yield of glycerol to glucose 0.37 g/g, which was 225% higher than the control group. By fermenting the enzymatic hydrolysate of . pretreated in seawater, the total conversion rate of glucose into glycerol and ethanol reached 0.45 g/g. This study indicates that hypertonic . exhibits remarkable adaptability to substrate, salt, and temperature. It not only can directly utilize complex lignocellulosic hydrolysates, but also exhibits strong tolerance to them. Therefore, it provides a potential candidate strain for the production of bio-based chemicals using lignocellulosic processes.
Topics: Glycerol; Pichia; Fermentation; Glucose; Xylose
PubMed: 38545986
DOI: 10.13345/j.cjb.230432 -
Journal of Leukocyte Biology Mar 2024Neutrophils are the most abundant leukocytes in humans and play a role in the innate immune response by being the first cells attracted to the site of infection. While...
Neutrophils are the most abundant leukocytes in humans and play a role in the innate immune response by being the first cells attracted to the site of infection. While early studies presented neutrophils as almost exclusively glycolytic cells, recent advances show that these cells use several metabolic pathways other than glycolysis, such as the pentose phosphate pathway, oxidative phosphorylation, fatty acid oxidation, and glutaminolysis, which they modulate to perform their functions. Metabolism shifts from fatty acid oxidation-mediated mitochondrial respiration in immature neutrophils to glycolysis in mature neutrophils. Tissue environments largely influence neutrophil metabolism according to nutrient sources, inflammatory mediators, and oxygen availability. Inhibition of metabolic pathways in neutrophils results in impairment of certain effector functions, such as NETosis, chemotaxis, degranulation, and reactive oxygen species generation. Alteration of these neutrophil functions is implicated in certain human diseases, such as antiphospholipid syndrome, coronavirus disease 2019, and bronchiectasis. Metabolic regulators such as AMPK, HIF-1α, mTOR, and Arf6 are linked to neutrophil metabolism and function and could potentially be targeted for the treatment of diseases associated with neutrophil dysfunction. This review details the effects of alterations in neutrophil metabolism on the effector functions of these cells.
PubMed: 38452242
DOI: 10.1093/jleuko/qiae025 -
Journal of Molecular Biology Jan 2024Alternative DNA structures that differ from the canonical B-form of DNA can arise from repetitive sequences and play beneficial roles in many cellular processes such as... (Review)
Review
Alternative DNA structures that differ from the canonical B-form of DNA can arise from repetitive sequences and play beneficial roles in many cellular processes such as gene regulation and chromatin organization. However, they also threaten genomic stability in several ways including mutagenesis and collisions with replication and/or transcription machinery, which lead to genomic instability that is associated with human disease. Thus, the careful regulation of non-B-DNA structure formation and resolution is crucial for the maintenance of genome integrity. Several protein factors have been demonstrated to associate with alternative DNA structures to facilitate their removal, one of which is the ADP-ribose transferase (ART) PARP1 (also called ADP-ribosyltransferase diphtheria toxin-like 1 or ARTD1), a multifaceted DNA repair enzyme that recognizes single- and double-stranded DNA breaks and synthesizes chains of poly (ADP-ribose) (PAR) to recruit DNA repair proteins. It is now well appreciated that PARP1 recognizes several nucleic acid structures beyond DNA lesions, including stalled replication forks, DNA hairpins and cruciforms, R-loops, and DNA G-quadruplexes (G4 DNA). In this review, we summarize the current evidence of a direct association of PARP1 with each of these aforementioned alternative DNA structures, as well as discuss the role of PARP1 in the prevention of non-B-DNA structure-induced genetic instability. We will focus on the mechanisms of the recognition and binding by PARP1 to each alternative structure and the structure-based stimulation of PARP1 catalytic activity upon binding. Finally, we will discuss some of the outstanding gaps in the literature and offer speculative insight for questions that remain to be experimentally addressed.
Topics: Humans; DNA; DNA Repair; Gene Expression Regulation; Genomic Instability; Poly (ADP-Ribose) Polymerase-1; Ribose; DNA, Cruciform; Animals
PubMed: 37481154
DOI: 10.1016/j.jmb.2023.168207 -
Molecular Therapy : the Journal of the... Dec 2023Mutations in the fukutin-related protein (FKRP) gene cause dystroglycanopathy, with disease severity ranging from mild LGMD2I to severe congenital muscular dystrophy....
Mutations in the fukutin-related protein (FKRP) gene cause dystroglycanopathy, with disease severity ranging from mild LGMD2I to severe congenital muscular dystrophy. Recently, considerable progress has been made in developing experimental therapies, with adeno-associated virus (AAV) gene therapy and ribitol treatment demonstrating significant therapeutic effect. However, each treatment has its strengths and weaknesses. AAV gene therapy can achieve normal levels of transgene expression, but it requires high doses, with toxicity concerns and variable distribution. Ribitol relies on residual FKRP function and restores limited levels of matriglycan. We hypothesized that these two treatments can work synergistically to offer an optimized therapy with efficacy and safety unmatched by each treatment alone. The most effective treatment is the combination of high-dose (5e-13 vg/kg) AAV-FKRP with ribitol, whereas low dose (1e-13 vg/kg) AAV-FKRP combined with ribitol showed a 22.6% increase in positive matriglycan fibers and the greater improvement in pathology when compared to low-dose AAV-FKRP alone. Together, our results support the potential benefits of combining ribitol with AAV gene therapy for treating FKRP-related muscular dystrophy. The fact that ribitol is a metabolite in nature and has already been tested in animal models and clinical trials in humans without severe side effects provides a safety profile for it to be trialed in combination with AAV gene therapy.
Topics: Animals; Humans; Pentosyltransferases; Ribitol; Dependovirus; Dystroglycans; Muscular Dystrophies; Genetic Therapy; Mutation; Muscle, Skeletal
PubMed: 37919902
DOI: 10.1016/j.ymthe.2023.10.022 -
International Journal of Molecular... Nov 2023Salt stress has a considerable impact on the development and growth of plants. The soil is currently affected by salinisation, a problem that is becoming worse every...
Salt stress has a considerable impact on the development and growth of plants. The soil is currently affected by salinisation, a problem that is becoming worse every year. This means that a significant amount of salt-tolerant plant material needs to be added. has aesthetically pleasing leaves, unique flowers, and a remarkable tolerance to salt. In this study, RNA-seq technology was used to sequence and analyse the transcriptome of the root of seedlings subjected to 200 mM NaCl treatment for 12, 24, and 48 h. In total, 12 seedling root transcriptome libraries were constructed. At the three time points of salt treatment compared with the control, 3888, 1907, and 1479 differentially expressed genes (DEGs) were identified, respectively. Various families of transcription factors (TFs), mainly AP2, MYB, and bHLH, were identified and might be linked to salt tolerance. Gene Ontology (GO) analysis of DEGs revealed that the structure and composition of the cell wall and cytoskeleton may be crucial in the response to salt stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of the DEGs showed a significant enrichment of the pentose and glucuronate interconversion pathway, which is associated with cell wall metabolism after 24 and 48 h of salt treatment. Based on GO and KEGG analyses of DEGs, the pentose and glucuronate interconversion pathway was selected for further investigation. AP2, MYB, and bHLH were found to be correlated with the functional genes in this pathway based on a correlation network. This study provides the groundwork for understanding the key pathways and gene networks in response to salt stress, thereby providing a theoretical basis for improving salt tolerance in .
Topics: Salt Tolerance; Aquilegia; Gene Expression Regulation, Plant; Gene Expression Profiling; Transcriptome; Seedlings; Glucuronates; Pentoses; Salinity
PubMed: 38003641
DOI: 10.3390/ijms242216450