Glucose Catabolism Research Articles

Insights into the fatty acid binding protein of Pacific white shrimp (Litopenaeus vannamei) suffering acute hepatopancreatic necrosis disease infection

Acute hepatopancreatic necrosis disease (AHPND) has a significant economic impact on aquaculture worldwide. However, the molecular mechanism responsible for AHPND remains unknown. Our previous study demonstrated that the Litopenaeus vannamei fatty acid binding protein (LvFABP) interacted with the Vibrio parahaemolyticus toxin PirB, and that silencing LvFABP using RNA interference improved AHPND resistance in shrimp. Polyclonal antibodies against recombinant LvFABP and PirBvp toxin were produced to further elucidate the role of LvFABP in AHPND resistance. Immunofluorescence localization showed that LvFABP was abundant throughout the cytoplasm of the hepatopancreas cells, and a co-localization assay revealed that PirBvp directly interacted with LvFABP. Antibodies against LvFABP were able to partially block the binding of LvFABP to PirBvpin vitro and inhibited AHPND infection in vivo. Exogenous recombinant LvFABP had a partially neutralizing effect against AHPND and gave L. vannamei significant protection against infection. In addition, recombinant LvFABP treatment of L. vannamei significantly reduced the morphological damage to the shrimp following pathogen challenge. The transcriptomes of the L. vannamei hepatopancreas with and without V. parahaemolyticus infection after silencing of LvFABP by RNA interference were also explored. The results showed that AHPND infection could affect the health of L. vannamei via functional changes in carbohydrate metabolism, lipid metabolism, and transport and catabolism. Furthermore, silencing LvFABP could effectively protect metabolism, transport and catabolic homeostasis, thus enabling adaptation to further or prolonged AHPND infections. These findings provided a unique and important dataset that deepened our understanding of the pathological mechanism of AHPND and may help in the development of strategies to prevent and ameliorate the effects of bacterial diseases.

Antifungal Activity and Potential Action Mechanism of Allicin against Trichosporon asahii.

Trichosporon asahii is an emerging opportunistic pathogen that causes potentially fatal disseminated trichosporonosis. The global prevalence of coronavirus disease 2019 (COVID-19) poses an increasing fungal infection burden caused by T. asahii. Allicin is the main biologically active component with broad-spectrum antimicrobial activity in garlic. In this study, we performed an in-depth analysis of the antifungal characteristics of allicin against T. asahii based on physiological, cytological, and transcriptomic assessments. In vitro, allicin inhibited the growth of T. asahii planktonic cells and biofilm cells significantly. In vivo, allicin improved the mean survival time of mice with systemic trichosporonosis and reduced tissue fungal burden. Electron microscopy observations clearly demonstrated damage to T. asahii cell morphology and ultrastructure caused by allicin. Furthermore, allicin increased intracellular reactive oxygen species (ROS) accumulation, leading to oxidative stress damage in T. asahii cells. Transcriptome analysis showed that allicin treatment disturbed the biosynthesis of cell membrane and cell wall, glucose catabolism, and oxidative stress. The overexpression of multiple antioxidant enzymes and transporters may also place an additional burden on cells, causing them to collapse. Our findings shed new light on the potential of allicin as an alternative treatment strategy for trichosporonosis. IMPORTANCE Systemic infection caused by T. asahii has recently been recognized as an important cause of mortality in hospitalized COVID-19 patients. Invasive trichosporonosis remains a significant challenge for clinicians, due to the limited therapeutic options. The present work suggests that allicin holds great potential as a therapeutic candidate for T. asahii infection. Allicin demonstrated potent in vitro antifungal activity and potential in vivo protective effects. In addition, transcriptome sequencing provided valuable insights into the antifungal effects of allicin.

The metabolic state of the heart regulates mitochondrial supercomplex abundance in mice

Mitochondrial supercomplexes are observed in mammalian tissues with high energy demand and may influence metabolism and redox signaling. Nevertheless, the mechanisms that regulate supercomplex abundance remain unclear. In this study, we examined the composition of supercomplexes derived from murine cardiac mitochondria and determined how their abundance changes with substrate provision or by genetically induced changes to the cardiac glucose-fatty acid cycle. Protein complexes from digitonin-solubilized cardiac mitochondria were resolved by blue-native polyacrylamide gel electrophoresis and were identified by mass spectrometry and immunoblotting to contain constituents of Complexes I, III, IV, and V as well as accessory proteins involved in supercomplex assembly and stability, cristae architecture, carbohydrate and fat oxidation, and oxidant detoxification. Respiratory analysis of high molecular mass supercomplexes confirmed the presence of intact respirasomes, capable of transferring electrons from NADH to O2. Provision of respiratory substrates to isolated mitochondria augmented supercomplex abundance, with fatty acyl substrate (octanoylcarnitine) promoting higher supercomplex abundance than carbohydrate-derived substrate (pyruvate). Mitochondria isolated from transgenic hearts that express kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (GlycoLo), which decreases glucose utilization and increases reliance on fatty acid oxidation for energy, had higher mitochondrial supercomplex abundance and activity compared with mitochondria from wild-type or phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-expressing hearts (GlycoHi), the latter of which encourages reliance on glucose catabolism for energy. These findings indicate that high energetic reliance on fatty acid catabolism bolsters levels of mitochondrial supercomplexes, supporting the idea that the energetic state of the heart is regulatory factor in supercomplex assembly or stability.

Obligate autotrophy at the thermodynamic limit of life in a new acetogenic bacterium.

One of the important current issues of bioenergetics is the establishment of the thermodynamic limits of life. There is still no final understanding of what is the minimum value of the energy yield of a reaction that is sufficient to be used by an organism (the so-called "biological quantum of energy"). A reasonable model for determination of the minimal energy yield would be microorganisms capable of living on low-energy substrates, such as acetogenic prokaryotes. The most prominent metabolic feature of acetogens is autotrophic growth with molecular hydrogen and carbon dioxide as the substrates, which is hardly competitive in environments. Most probably, that is why only facultative autotrophic acetogens have been known so far. Here, we describe the first obligately autotrophic acetogenic bacterium Aceticella autotrophica gen. nov., sp. nov., strain 3443-3AcT. Phylogenetically, the new genus falls into a monophyletic group of heterotrophic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, and Caldanaerobacter (hereinafter referred to as TTC group), where the sole acetogenic representative has so far been the facultatively autotrophic Thermoanaerobacter kivui. A. autotrophica and T. kivui both are acetogens employing energy-converting hydrogenase (Ech-acetogens) that are likely to have inherited the acetogenesis capacity vertically from common ancestor. However, their acetogenic machineries have undergone different adjustments by gene replacements due to horizontal gene transfers from different donors. Obligate autotrophy of A. autotrophica is associated with the lack of many sugar transport systems and carbohydrate catabolism enzymes that are present in other TTC group representatives, including T. kivui.

Sex-specific alteration in human muscle transcriptome with age.

Sarcopenia is a medical condition that progressively develops with age and results in reduced skeletal muscle mass, alteration in muscle composition, and decreased muscle strength. Several clinical studies suggested that sarcopenia disproportionally affects males and females with age. Despite this knowledge, the molecular mechanism governing the pathophysiology is not well understood in a sex-specific manner. In this study, we utilized human gastrocnemius muscles from males and females to identify differentially regulated genes with age. We found 269 genes with at least a twofold expression difference in the aged muscle transcriptome. Among the female muscle samples, there were 239 differentially regulated genes, and the novel protein-coding genes include KIF20A, PIMREG, MTRNR2L6, TRPV6, EFNA2, RNF24, and SFN. In aged male skeletal muscle, there were 166 differentially regulated genes, and the novel-protein coding genes are CENPK, CDKN2A, BHLHA15, and EPHA. Gene Ontology (GO) enrichment revealed glucose catabolism, NAD metabolic processes, and muscle fiber transition pathways that are involved in aged female skeletal muscle, whereas replicative senescence, cytochrome C release, and muscle composition pathways are disrupted in aged male skeletal muscle. Targeting these novels, differentially regulated genes, and signaling pathways could serve as sex-specific therapeutic targets to combat the age-related onset of sarcopenia and promote healthy aging.

Protein-Sparing Effect of α-Lipoic Acid in Diets with Different Protein/Carbohydrate Ratios for the Oriental River Prawn, Macrobrachium nipponense

Carbohydrates are commonly used in aquaculture feed because they are the cheapest energy source. Promoting carbohydrate catabolism for energy production can increase the dietary protein utilization efficiency (i.e., a protein-sparing effect). Alpha-lipoic acid (α-LA) is a cofactor of some rate-limiting key enzymes (pyruvate dehydrogenase complex and α-ketoglutarate dehydrogenase) in carbohydrate metabolism. To determine whether α-LA could promote carbohydrate catabolism to have a protein-sparing effect, we investigated the growth, activities of key enzymes involved in carbohydrate metabolism, transcript levels of genes encoding enzymes involved in energy metabolism, and the hepatopancreas structure of Macrobrachium nipponense fed with diets containing different protein/carbohydrate ratios (P/C) with and without α-LA. Six experimental diets for M. nipponense were formulated with casein and fish meal as the protein sources, fish oil and soybean oil as the lipid sources, and corn starch as the carbohydrate source. The six diets consisted of three different P/Cs ( P 41 / C 18 , P 37 / C 24 , and P 33 / C 30 ) without or with α-LA (at 1300 mg/kg). Each diet had six replicates and was fed to prawns (initial weight 0.110 ± 0.010 g) twice daily to apparent satiation. Dietary supplementation with α-LA significantly increased the survival rate of prawns, regardless of the P/C ratio. In the low-P/C group ( P 33 / C 30 ), the weight gain did not vary between those that consumed α-LA and those that did not. The P/C ratio and α-LA significantly affected the activities of key enzymes involved in glycolysis and the citric acid cycle. In the P 41 / C 18 group, the hexokinase (HK) and pyruvate dehydrogenase (PDH) activities were significantly higher in prawns that consumed α-LA than in those that did not. In both the P 37 / C 24 and P 33 / C 30 groups, the pyruvate kinase (PK) activity was significantly higher in prawns that consumed α-LA than in those that did not. Significant interactions between P/C and α-LA were found for the transcript levels of genes encoding adenine ribonucleotide-dependent protein kinase subunits (AMPK αand AMPK β), HK, glucose-6-phosphate dehydrogenase (G6PDH), acetyl-CoA carboxylase (ACC), and fatty acid binding protein 10 (FABP 10), all of which are involved in energy metabolism. In the low-P/C group, α-LA increased the transcript levels of genes encoding AMPK α, AMPK β, HK, phosphoenolpyruvate carboxykinase (PEPCK), G6PDH, and MDH, decreased the transcript level of the gene encoding ACC, and did not affect the transcript levels of genes encoding FABP10 and palmitoyl transferase 1 (CPT1). The P/C ratio and α-LA did not affect the overall morphology of the hepatopancreas, but at a low P/C, dietary supplementation of α-LA increased the number of hepatopancreatic B cells. In conclusion, supplementation with α-LA at 1300 mg/kg in a low-P/C diet of M. nipponense increased its carbohydrate utilization efficiency, energy metabolism, and the number of hepatopancreas B cells, thereby having a protein-sparing effect.

Oncogenic roles of GPR176 in breast cancer: a potential marker of aggressiveness and a potential target of gene therapy.

Belonging to the G-protein coupled receptor 1 family, G protein-coupled receptor 176 (GPR176) is associated with the Gz/Gx G-protein subclass and is capable of decreasing cAMP production. GPR176 expression was detected by qRT-PCR, bioinformatics analysis, Western blot and immunohistochemistry, and compared with clinicopathological characteristics of breast cancer. GPR176-related genes and pathways were subjected to bioinformatic analysis. We also explored the effects of GPR176 on the phenotypes of breast cancer cells. Lower expression of GPR176 mRNA was seen in breast cancer than in normal tissues, but the opposite pattern was found for its protein (p < 0.05). GPR176 mRNA was associated with female sex, low T staging, non-Her-2+ subtypes, non-mutant p53 status in breast cancer (p < 0.05). GPR176 methylation was negatively correlated with its mRNA level and T staging in breast cancer, and was higher in breastcancer than normal tissues (p < 0.05). GPR176 protein expression was positively correlated with older age, small tumor size, and non-luminal-B subtype of breast cancers (p < 0.05). The differential genes of GPR176 were involved in receptor-ligand interaction, RNA maturation, and so forth (p < 0.05). GPR176-related genes were categorized into cell mobility, membrane structure, and so on (p < 0.05). GPR176 knockdown weakened the proliferation, glucose catabolism, anti-apoptosis, anti-pyroptosis, migration, invasion, and epithelial-mesenchymal transition of breast cancer cells. These results indicate that GPR176 might be involved in the tumorigenesis and subsequent progression of breast cancer by deteriorating aggressive phenotypes. It might be utilized as a potential biomarker to indicate the aggressive behaviors and poor prognosis of breast cancer and a potential target of genetic therapy.

Changes in the mRNA expression of glycolysis-related enzymes of Candida albicans during inhibition of intramitochondrial catabolism under anaerobic condition.

Candida albicans can cause two major types of infections: superficial infection and systemic candidiasis. C. albicans infects diverse host niches, owing to a wide range of virulence factors and attributes, such as morphological transitions and phenotypic switching. C. albicans uses glycolysis, followed by alcoholic fermentation or mitochondrial respiration to rapidly generate ATP under aerobic conditions. In this study, we quantified the mRNA expression of several glycolysis-related enzymes associated with the initial phase of environmental changes using two strains: a type strain, NBRC 1385, and a strain from a patient with auto-brewery syndrome, LSEM 550. Additionally, we analyzed the regulation of a rate-limiting enzyme in glycolysis, phosphofructokinase 1 (PFK1). Our results showed that the mRNA expression of enzymes in the middle and last stages of glycolysis and alcoholic fermentation increased, and that of mitochondrial respiration enzymes decreased under short-term anaerobic conditions. Carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) administration showed similar results under anaerobic conditions. Moreover, PFK1 maintained its regulatory effect under different conditions; no significant change was observed in its mRNA expression. Our results suggest that C. albicans obtains energy via carbohydrate catabolism in the early phase of environmental change and survives in various parts of the host.

High triacylglycerol turnover is required for efficient opening of stomata during heat stress in Arabidopsis.

Heat stress triggers the accumulation of triacylglycerols in Arabidopsis leaves, which increases basal thermotolerance. However, how triacylglycerol synthesis is linked to thermotolerance remains unclear and the mechanisms involved remain to be elucidated. It has been shown that triacylglycerol and starch degradation are required to provide energy for stomatal opening induced by blue light at dawn. To investigate whether triacylglycerol turnover is involved in heat-induced stomatal opening during the day, we performed feeding experiments with labeled fatty acids. Heat stress strongly induced both triacylglycerol synthesis and degradation to channel fatty acids destined for peroxisomal ß-oxidation through the triacylglycerol pool. Analysis of mutants defective in triacylglycerol synthesis or peroxisomal fatty acid uptake revealed that triacylglycerol turnover and fatty acid catabolism are required for heat-induced stomatal opening in illuminated leaves. We show that triacylglycerol turnover is continuous (1.2 mol% per min) in illuminated leaves even at 22°C. The ß-oxidation of triacylglycerol-derived fatty acids generates C2 carbon units that are channeled into the tricarboxylic acid pathway in the light. In addition, carbohydrate catabolism is required to provide oxaloacetate as an acceptor for peroxisomal acetyl-CoA and maintain the tricarboxylic acid pathway for energy and amino acid production during the day.

Abstract 3037: Effect of obesity on the promoter methylation of regulators of glucose catabolism and its association with prognosis in colorectal cancer

Abstract Metabolic alterations due to obesity are involved in the development of colorectal cancer (CRC) and it may mediate epigenetic alterations such as changes in DNA methylation. This research aimed to associate the effect of obesity on both the methylation of promoters of genes regulating glucose catabolism (n=52) and the prognosis of CRC. The study population was composed of 301 CRC patients of the TCGA-COADREAD project whose clinical and epigenomic data were available. Patients were classified by BMI according to the WHO guidelines. Multiple linear regression was used to estimate the relationship between gene expression and promoter methylation status with BMI. Logistic regression models were used to estimate a correlation between gene expression and promoter methylation status with response to primary anticancer treatment. Kaplan Meier plots were used to determine the association between the gene promoter methylation and overall survival (OS). Mean BMI was 25.2 kg/m2 (± 3.8) and, the prevalence of obesity was 29% in the TCGA-COADREAD cohort. Under-expression of ACO2, PGAM1, and TPI1 genes, and over-expression of GCK were found with an increase in BMI. Also, hypermethylation of the ACO2 (OR: 3.62e-57, CI 3.2e-112 - 0.04) and PGAM1 (OR: 1.75e-22, CI 0.04 - 3.8) promoters decreases the probability of complete remission in CRC patients. Only genes HKDC1 and OGDHL resulted differentially methylated between obese and non-obese CRC patients but their expression was not associated with OS (p&amp;gt;0.05). We concluded that an increase in BMI is associated with changes in expression and promoter methylation of a group of glucose catabolism regulators in CRC. Such changes are associated with disease remission in CRC patients (Table 1). Our results may raise awareness about obesity's effects on CRC prognosis. Further research is encouraged on glucose catabolism genes and their methylation levels to confirm and validate such factors as prognostic markers of CRC. GE: Gene expression, PRM: Promoter region methylation. Adjusted by age, BMI, and presence of polyps. Crude model Adjusted model Response to primary treatment OR 95% CI OR 95% CI ACO2 GE 1.53 0.5 - 4.6 1.56 0.4 - 5.8 PRM 8.99e-36 7.6e-86 - 1.1e+11 3.62e-57 3.2e-112 - 0.04 GCK GE 1.52 0.8 - 3 1.24 0.5 - 2.9 PRM 249.8 0.3 - 204182.6 341.4 0.1 - 1209515 HKDC1 GE 1.3 0.8 - 1.9 1.4 0.87 - 2.3 PRM 0.3 0.03 - 2.4 0.38 0.04 - 3.8 OGDHL GE 1.64 1.13 - 2.4 1.93 1.2 - 3.1 PRM 24.99 0.09 - 6903.4 14458.2 0.01 - 1.49e+10 PGAM1 GE 1.17 0.5 - 2.9 1.24 0.4 - 3.7 PRM 2.48e-13 0.03 - 2.4 1.75e-22 0.04 - 3.8 TPI1 GE 1.62 0.5 - 4.9 1.68 0.4 - 6.5 PRM 1.08e-32 4.1e-104 - 2.84e+39 4.01e-73 5.3e-161 - 3.1e+15 Citation Format: Valeria Clara Morales Ancajima, Claudia Inés Machicado Rivero. Effect of obesity on the promoter methylation of regulators of glucose catabolism and its association with prognosis in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3037.

Evolution of cisplatin resistance through coordinated metabolic reprogramming of the cellular reductive state.

Cisplatin (CDDP) is a mainstay treatment for advanced head and neck squamous cell carcinomas (HNSCC) despite a high frequency of innate and acquired resistance. We hypothesised that tumours acquire CDDP resistance through an enhanced reductive state dependent on metabolic rewiring. To validate this model and understand how an adaptive metabolic programme might be imprinted, we performed an integrated analysis of CDDP-resistant HNSCC clones from multiple genomic backgrounds by whole-exome sequencing, RNA-seq, mass spectrometry, steady state and flux metabolomics. Inactivating KEAP1 mutations or reductions in KEAP1 RNA correlated with Nrf2 activation in CDDP-resistant cells, which functionally contributed to resistance. Proteomics identified elevation of downstream Nrf2 targets and the enrichment of enzymes involved in generation of biomass and reducing equivalents, metabolism of glucose, glutathione, NAD(P), and oxoacids. This was accompanied by biochemical and metabolic evidence of an enhanced reductive state dependent on coordinated glucose and glutamine catabolism, associated with reduced energy production and proliferation, despite normal mitochondrial structure and function. Our analysis identified coordinated metabolic changes associated with CDDP resistance that may provide new therapeutic avenues through targeting of these convergent pathways.

β-hydroxybutyrate does not influence viability and clonogenicity of A549 lung cancer cells

Background/Purpose: The metabolic shift from catabolism of carbohydrates to lipids results in production of ketone bodies leading to a state called ketosis. Ketosis via ketone supplement or ketogenic diet has been proposed as a non-toxic therapeutic option for a broad range of malignancies. Although the clinical impact of ketogenic diet is well-documented, the effect of ketone bodies on cancer cell biology is not clear for some cancers including non-small-cell lung cancer (NSCLC). In this study, we aimed to demonstrate the effects of the most prominent ketone body, β-hydroxybutyrate, on a NSCLC cell line, A549. &#x0D; Methods: A549 cell line was utilized as the in vitro model in this study. The effects of different β-hydroxybutyrate concentrations on cell viability were measured via sulforhodamine-B (SRB) viability assay. Long term effects of ketosis were evaluated via colony formation assay. Finally, the effect of β-hydroxybutyrate on cell migration was determined via scratch assay. &#x0D; Results: Our results suggest that introduction of β-hydroxybutyrate in physiologically relevant concentrations into the cell culture media does not influence cell viability, clonogenicity or migration. &#x0D; Conclusion: β-hydroxybutyrate has been previously demonstrated to induce, inhibit or does not influence the viability of different cell lines but there is no report regarding its effects on NSCLC cells. Here we report that physiologically relevant concentrations of β-hydroxybutyrate have no effect on viability, clonogenicity and migration of A549 cells.

Lactate regulates cell cycle by remodelling the anaphase promoting complex.

Lactate is abundant in rapidly dividing cells owing to the requirement for elevated glucose catabolism to support proliferation1-6. However, it is not known whether accumulated lactate affects the proliferative state. Here we use a systematic approach to determine lactate-dependent regulation of proteins across the human proteome. From these data, we identify a mechanism of cell cycle regulation whereby accumulated lactate remodels the anaphase promoting complex (APC/C). Remodelling of APC/C in this way is caused by direct inhibition of the SUMO protease SENP1 by lactate. We find that accumulated lactate binds and inhibits SENP1 by forming a complex with zinc in the SENP1 active site. SENP1 inhibition by lactate stabilizes SUMOylation of two residues on APC4, which drives UBE2C binding to APC/C. This direct regulation of APC/C by lactate stimulates timed degradation of cell cycle proteins, and efficient mitotic exit in proliferative human cells. This mechanism is initiated upon mitotic entry when lactate abundance reaches its apex. In this way, accumulation of lactate communicates the consequences of a nutrient-replete growth phase to stimulate timed opening of APC/C, cell division and proliferation. Conversely, persistent accumulation of lactate drives aberrant APC/C remodelling and can overcome anti-mitotic pharmacology via mitotic slippage. In sum, we define a biochemical mechanism through which lactate directly regulates protein function to control the cell cycle and proliferation.

NADH dehydrogenases are the predominant phenazine reductases in the electron transport chain of Pseudomonas aeruginosa.

Phenazines are redox-active secondary metabolites produced by diverse bacteria including the opportunistic pathogen Pseudomonas aeruginosa. Extracellular electron transfer via phenazines enhances anaerobic survival by serving as an electron sink for glucose catabolism. However, the specific phenazine reductase(s) used to support this catabolism are unknown. Because electron transport chain components have been previously implicated in phenazine reduction, we sought to determine which of them possess phenazine reductase activity. We show that phenazine-1-carboxamide (PCN) and pyocyanin (PYO) are reduced at the highest rate by cells and are localized to the cell envelope while reduced. Using a coupled genetic and biochemical approach, we show that phenazine reductase activity in membrane fractions is attributable to the three NADH dehydrogenases present in P. aeruginosa and that their order of phenazine reductase activity is Nqr > Nuo > Ndh. In mutants possessing only one functional NADH dehydrogenase, whole cell reduction rates of PCN, but not PYO, recapitulate the pattern of biochemical results, implying that PYO reduction is predominantly occurring in the cytosol. Lastly, we show that ubiquinone rapidly and non-enzymatically oxidizes reduced phenazines, demonstrating that phenazines have the capability to serve in a redox loop between the NADH and ubiquinone pools, a finding that carries bioenergetic implications.

Phytochemical Properties, Antioxidant Activity and α- Amilase Inhibitory of Curcuma Caesia

Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia, which produces free radicals, particularly reactive oxygen species (ROS), through glucose auto-oxidation and glycosylation. Administration of antioxidants and polyphenolic compound components can capture free radicals and reduce oxidative stress. Polyphenols are also able to reduce blood glucose levels by inhibiting the action of amylase enzymes as carbohydrate catabolism so that glucose absorption does not occur. One of the plants that contain polyphenols is Black Turmeric (Curcuma caesia). Some studies on the rhizomes of this plant include methanol extracts containing phenolics, Flavonoids, alkaloids, triterpenoids, saponins, and tannins. Dry powders and wet rhizome powders were studied to have antioxidant activity. Research on the inhibition of the enzyme alfa amylase is still lacking. This study aims to determine the content of chemical compounds using 70% ethanol solvent. The total phenolic and flavonoid assay with spectrophotometry, determine antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) at 490 nm and inhibition of α-amylase enzyme using 3,5- dinitro salicylic acid (DNS) at 529 nm. The results showed that phenolic levels were 235 mgGAE/100gr, flavonoids were 61 mg QE/100gr, Alkaloids 30 mg Quinine /100gr and saponin 158 mg Quillaja bark/100gr, dan tannin 535mg tannic acid/100gr. DPPH antioxidant activity obtained IC50 value of 299,18 µg/mLµg/mL and α- amylase inhibitory 50,26 µg/mLµg/mL. The research showed that 70% ethanol extract Curcuma caesia roxb contains phenolic, flavonoids, alkaloids, quinine, and saponins constituents and have been antioxidant activity and high α-amylase inhibitory

Portable dual-mode biosensor based on smartphone and glucometer for on-site sensitive detection of Listeria monocytogenes

Contamination of Listeria monocytogenes (L. monocytogenes) in the environment and food can pose a serious threat to human health, and there is an urgent need to establish sensitive on-situ detection methods to mitigate its hazards. In this study, we have developed a field assay that combines magnetic separation technology with antibody-labeled ZIF-8 encapsulating glucose oxidase (GOD@ZIF-8@Ab) to capture and specifically identify L. monocytogenes while GOD catalyzes glucose catabolism to produce signal changes in glucometers. On the other side, horseradish peroxidase (HRP) and 3,3′,5,5′-tetramethylbenzidine (TMB) were added to recombined with the H2O2 generated by the catalyst to form a colorimetric reaction system that changes from colorless to blue. The smartphone software was used for RGB analysis to complete the on-site colorimetric detection of L. monocytogenes. This dual-mode biosensor showed good detection performance for the on-site application of L. monocytogenes in lake water and juice samples, both with a limit of detection up to 101 CFU/mL and a good linear range of 101–106 CFU/mL. Therefore, this dual-mode on-site detection biosensor has a promising application for the early screening of L. monocytogenes in environmental and food samples.

Metformin induces pyroptosis in leptin receptor-defective hepatocytes via overactivation of the AMPK axis

Metformin is the biguanide of hepatic insulin sensitizer for patients with non-alcohol fatty liver disease (NAFLD). Findings regarding its efficacy in restoring blood lipids and liver histology have been contradictory. In this study, we explore metformin’s preventive effects on NAFLD in leptin-insensitive individuals. We used liver tissue, serum exosomes and isolated hepatocytes from high-fat diet (HFD)-induced Zucker diabetic fatty (ZDF) rats and leptin receptor (Lepr) knockout rats to investigate the correlation between hepatic Lepr defective and liver damage caused by metformin. Through immunostaining, RT-PCR and glucose uptake monitoring, we showed that metformin treatment activates adenosine monophosphate (AMP)-activated protein kinase (AMPK) and its downstream cytochrome C oxidase (CCO). This leads to overactivation of glucose catabolism-related genes, excessive energy repertoire consumption, and subsequent hepatocyte pyroptosis. Single-cell RNA sequencing further confirmed the hyper-activation of glucose catabolism after metformin treatment. Altogether, we showed that functional Lepr is necessary for metformin treatment to be effective, and that long-term metformin treatment might promote NAFLD progression in leptin-insensitive individuals. This provides important insight into the clinical application of metformin.

Synthesis of new diphenyl urea-clubbed imine analogs and its Implications in diabetic management through in vitro and in silico approaches

Type II diabetes mellitus (T2DM) is a global health issue with high rate of prevalence. The inhibition of α-glucosidase enzyme has prime importance in the management of T2DM. This study was established to synthesize Schiff bases of 1,3-dipheny urea (3a–y) and to investigate their in vitro anti-diabetic capability via inhibiting α-glucosidase, a key player in the catabolism of carbohydrates. The structures of all compounds were confirmed through various techniques including, Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) and mass-spectrometry (MS) methods. Interestingly all these compounds displayed potent inhibition IC50 values in range of 2.14–115 µM as compared to acarbose used as control. Additionally, all the compounds were docked at the active site of α-glucosidase to predict their mode of binding. The docking results indicates that Glu277 and Asn350 play important role in the stabilization of these compounds in the active site of enzyme. These molecules showed excellent predicted pharmacokinetics, physicochemical and drug-likeness profile. The anti-diabetic potential of these molecules signifies their medical importance and provide insights into prospective therapeutic options for the treatment of T2DM.

The impact of glucose on mitochondria and life span is determined by the integrity of proline catabolism in Caenorhabditis elegans

Mutations in genes involved in mitochondrial proline catabolism lead to the rare genetic disorder hyperprolinemia in humans. We have previously reported that mutations of proline catabolic genes in Caenorhabditis elegans impair mitochondrial homeostasis and shorten life span, and that these effects surprisingly occur in a diet type-dependent manner. Therefore, we speculated that a specific dietary component may mitigate the adverse effects of defective proline catabolism. Here, we discovered that high dietary glucose, which is generally detrimental to health, actually improves mitochondrial homeostasis and life span in C.elegans with faulty proline catabolism. Mechanistically, defective proline catabolism results in a shift of glucose catabolism toward the pentose phosphate pathway, which is crucial for cellular redox balance. This shift helps to maintain mitochondrial reactive oxygen species homeostasis and to extend life span, as suppression of the pentose phosphate pathway enzyme GSPD-1 prevents the favorable effects of high glucose. In addition, we demonstrate that this crosstalk between proline and glucose catabolism is mediated by the transcription factor DAF-16. Altogether, these findings suggest that a glucose-rich diet may be advantageous in certain situations and might represent a potentially viable treatment strategy for disorders involving impaired proline catabolism.

Hypoxia tolerance in fish depends on catabolic preference between lipids and carbohydrates.

Hypoxia is a common environmental stress factor in aquatic organisms, which varies among fish species. However, the mechanisms underlying the ability of fish species to tolerate hypoxia are not well known. Here, we showed that hypoxia response in different fish species was affected by lipid catabolism and preference for lipid or carbohydrate energy sources. Activation of biochemical lipid catabolism through peroxisome proliferator-activated receptor alpha (Pparα) or increasing mitochondrial fat oxidation in tilapia decreased tolerance to acute hypoxia by increasing oxygen consumption and oxidative damage and reducing carbohydrate catabolism as an energy source. Conversely, lipid catabolism inhibition by suppressing entry of lipids into mitochondria in tilapia or individually knocking out three key genes of lipid catabolism in zebrafish increased tolerance to acute hypoxia by decreasing oxygen consumption and oxidative damage and promoting carbohydrate catabolism. However, anaerobic glycolysis suppression eliminated lipid catabolism inhibition-promoted hypoxia tolerance in adipose triglyceride lipase (atgl) mutant zebrafish. Using 14 fish species with different trophic levels and taxonomic status, the fish preferentially using lipids for energy were more intolerant to acute hypoxia than those preferentially using carbohydrates. Our study shows that hypoxia tolerance in fish depends on catabolic preference for lipids or carbohydrates, which can be modified by regulating lipid catabolism.