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Plant Physiology and Biochemistry : PPB Sep 2023Dendrobium catenatum, which belongs to the Orchidaceae family, has been used as a traditional medicine and healthy food in China for over 2000 years, and is of enormous...
Interactions between endophytic fungus Pestalotiopsis sp. DO14 and Dendrobium catenatum: Deciphering plant polysaccharide and flavonoid accumulation and underlying mechanisms by comparative transcriptome and metabolome analyses.
Dendrobium catenatum, which belongs to the Orchidaceae family, has been used as a traditional medicine and healthy food in China for over 2000 years, and is of enormous economic value. Polysaccharides and flavonoids are two major functional ingredients in D. catenatum stems that contribute to its health benefits. D. catenatum lives in close association with endophytic fungi, but the literature regarding the further relations between them, especially the fungal-induced accumulation of metabolites in the host plant, is sparse. Our previous study showed that Pestalotiopsis sp. DO14 isolated from D. catenatum improved the host plant growth and metabolite accumulation. This study was performed to investigate dynamic variations of the growth traits, key metabolites (polysaccharides and flavonoids), and expression of key genes of D. catenatum under conditions of the DO14 colonization. Colonization with DO14 promoted D. catenatum growth as indicated by increased leaf area, mid-stem thickness, and plant height. The content of polysaccharides, mannose, and sucrose increased even without DO14 entering the host cells or forming a mature symbiotic relationship concurrent with improved photosynthesis rate. Furthermore, DO14 induced upregulation of genes involved in sugar and flavonoid metabolism, especially phosphoenolpyruvate carboxykinase (PCKA), chalcone synthase (CHS) and UDP-glycose flavonoid glycosyltransferase (UFGT). These observations suggested that endophytic fungi induce the accumulation of polysaccharides and flavonoids by plants, increasing the efficiency of carbon assimilation and carbon turnover. The findings of this study provide insight into the mechanisms underlying Orchidaceae-endophyte interactions, and suggest potential novel applications of endophytic fungi in D. catenatum breeding to improved plant quality.
Topics: Flavonoids; Dendrobium; Transcriptome; Pestalotiopsis; Plant Breeding; Polysaccharides; Metabolome
PubMed: 37562204
DOI: 10.1016/j.plaphy.2023.107942 -
Journal of Bioscience and Bioengineering Nov 2023Recombinase polymerase amplification (RPA) is an isothermal DNA amplification reaction at around 41°C using recombinase (Rec), single-stranded DNA-binding protein...
Recombinase polymerase amplification (RPA) is an isothermal DNA amplification reaction at around 41°C using recombinase (Rec), single-stranded DNA-binding protein (SSB), strand-displacing DNA polymerase (Pol), and an ATP-regenerating enzyme. In this study, we attempted to use pyruvate kinase instead of creatine kinase (CK) that has been consistently used as an ATP-regenerating enzyme in RPA. Human pyruvate kinase M1 (PKM) was expressed in Escherichia coli and purified from the cells. RPA with PKM was performed at 41°C with the in vitro synthesized urease subunit β (ureB) DNA from Ureaplasma parvum serovar 3 as a standard DNA. The optimal concentrations of PKM and phosphoenolpyruvate were 20 ng/μL and 10 mM, respectively. The RPA reaction with PKM was more sensitive than that with CK. PKM exhibited higher thermostability than CK, suggesting that the RPA reagents with PKM are preferable to those with CK for onsite use.
PubMed: 37718149
DOI: 10.1016/j.jbiosc.2023.08.005 -
ACS Sensors Jun 2024The feasibility of hyperpolarized [2-C, 3-H]pyruvate for probing gluconeogenesis was investigated in this study. Whereas hyperpolarized [1-C]pyruvate has clear access...
The feasibility of hyperpolarized [2-C, 3-H]pyruvate for probing gluconeogenesis was investigated in this study. Whereas hyperpolarized [1-C]pyruvate has clear access to metabolic pathways that convert pyruvate to lactate, alanine, and bicarbonate, its utility for assessing pyruvate carboxylation and gluconeogenesis has been limited by technical challenges, including spectral overlap and an obscure enzymatic step that decarboxylates the labeled carbon. To achieve unambiguous detection of gluconeogenic products, the carbonyl carbon in pyruvate was labeled with C. To prolong the relaxation time, [2-C, 3-H]pyruvate was synthesized and dissolved with DO after dynamic nuclear polarization. The of [2-C, 3-H]pyruvate in DO could be improved by 76.9% (79.6 s at 1 T and 74.5 s at 3 T) as compared to [2-C]pyruvate in water. Hyperpolarized [2-C, 3-H]pyruvate with DO dissolution was applied to rat livers under normal feeding and fasting conditions. A gluconeogenic product, [2-C]phosphoenolpyruvate, was observed at 149.9 ppm from fasted rats only, highlighting the utility of [2-C, 3-H]pyruvate in detecting key gluconeogenic enzyme activities such as pyruvate carboxylase and phosphoenolpyruvate carboxykinase .
Topics: Animals; Gluconeogenesis; Liver; Pyruvic Acid; Rats; Male; Rats, Sprague-Dawley; Carbon Isotopes
PubMed: 38838349
DOI: 10.1021/acssensors.4c00734 -
The Science of the Total Environment Sep 2023Microplastics and nanoplastics (MPs and NPs) are abundant, persistent, and widespread environmental pollutants that are of increasing concern as they pose a serious...
Microplastics and nanoplastics (MPs and NPs) are abundant, persistent, and widespread environmental pollutants that are of increasing concern as they pose a serious threat to ecosystems and aquatic species. Identifying the ecological effects of NPs pollution requires understanding the effects of changing nanoplastics concentrations in aquatic organisms. Monopterus albus were orally fed three different concentrations of 100 nm polystyrene nanoplastics (PS-NPs): 0.05 %, 0.5 %, and 1 % of the feed for 28 days. Nanoplastics significantly activated the PPAR signaling pathway, Acyl-CoA oxidase 1 (ACOX1), carnitine palmitoyltransferase 1a (CPT1A), angiopoietin-like 4 (ANGPTL4), and phosphoenolpyruvate carboxykinase (PCK) at the mRNA level, resulting in disturbed lipid metabolism. Glutathione peroxidase (GSH-px) activity, catalase (CAT) activity, and malondialdehyde (MDA) were significantly elevated in the high nanoplastics-feeding exposure group, leading to oxidative stress in the liver. Overexpression of the cytokines genes Interleukin 1 (IL1B) and Interleukin-8 (IL8), Tumor necrosis factor alpha (TNF-α), activation of MAPK signaling pathway, and increased gene expression of c-Jun amino-terminal kinases (JNK) and p38 indicate that exposure to NPs may lead to hepatopancreas apoptosis through oxidative stress and inflammation. In summary, dietary PS-NPs exposure alters hepatic glycolipid metabolism, triggering inflammatory responses and apoptosis in M. albus. The results of this study provide valuable ecotoxicological data for a better understanding of the biological fate and effects of nanoplastics in M. albus.
Topics: Animals; Microplastics; Polystyrenes; Ecosystem; Plastics; Lipid Metabolism; Liver; Smegmamorpha; Apoptosis; Water Pollutants, Chemical; Nanoparticles
PubMed: 37247739
DOI: 10.1016/j.scitotenv.2023.164460 -
Journal of Applied Physiology... Feb 2024The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced...
The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced hypertension is mediated by insulin receptor (INSR) signaling and by leptin, which binds to the leptin receptor (LEPR) in CB and activates transient receptor potential channel subfamily M member 7 (TRPM7). We hypothesize that in mice with diet-induced obesity, hyperglycemia, glucose intolerance, and insulin resistance will be attenuated by the CB denervation (carotid sinus nerve dissection, CSND) and by knockdown of , and gene expression in CB. In series of experiments in 75 male diet-induced obese (DIO) mice, we performed either CSND (vs. sham) surgeries or shRNA-induced suppression of , , or gene expression in CB, followed by blood pressure telemetry, intraperitoneal glucose tolerance and insulin tolerance tests, and measurements of fasting plasma insulin, leptin, corticosterone, glucagon and free fatty acids (FFAs) levels, hepatic expression of gluconeogenesis enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G-6-Pase) mRNA and liver glycogen levels. CSND decreased blood pressure, fasting blood glucose levels and improved glucose tolerance without any effect on insulin resistance. CSND did not affect any hormone levels and gluconeogenesis enzymes, but increased liver glycogen level. Genetic knockdown of CB , and had no effect on glucose metabolism. We conclude that CB contributes to hyperglycemia of obesity, probably by modulation of the glycogen-glucose equilibrium. Diabetogenic effects of obesity on CB in mice do not occur via activation of CB , and . This paper provides first evidence that carotid body denervation abolishes hypertension and improves fasting blood glucose levels and glucose tolerance in mice with diet-induced obesity. Furthermore, we have shown that this phenomenon is associated with increased liver glycogen content, whereas insulin sensitivity and enzymes of gluconeogenesis were not affected.
Topics: Male; Mice; Animals; Leptin; Insulin Resistance; Blood Glucose; Carotid Body; Mice, Obese; TRPM Cation Channels; Liver Glycogen; Hyperglycemia; Obesity; Glucose; Hypertension; Denervation; Insulins
PubMed: 38126089
DOI: 10.1152/japplphysiol.00215.2023 -
Molecular Therapy : the Journal of the... Jul 2023IL-17-producing antigen-specific human T cells elicit potent antitumor activity in mice. Yet, refinement of this approach is needed to position it for clinical use....
IL-17-producing antigen-specific human T cells elicit potent antitumor activity in mice. Yet, refinement of this approach is needed to position it for clinical use. While activation signal strength regulates IL-17 production by CD4 T cells, the degree to which T cell antigen receptor (TCR) and costimulation signal strength influences Th17 immunity remains unknown. We discovered that decreasing TCR/costimulation signal strength by incremental reduction of αCD3/costimulation beads progressively altered Th17 phenotype. Moreover, Th17 cells stimulated with αCD3/inducible costimulator (ICOS) beads produced more IL-17A, IFNγ, IL-2, and IL-22 than those stimulated with αCD3/CD28 beads. Compared with Th17 cells stimulated with the standard, strong signal strength (three beads per T cell), Th17 cells propagated with 30-fold fewer αCD3/ICOS beads were less reliant on glucose and favored the central carbon pathway for bioenergetics, marked by abundant intracellular phosphoenolpyruvate (PEP). Importantly, Th17 cells stimulated with weak αCD3/ICOS beads and redirected with a chimeric antigen receptor that recognizes mesothelin were more effective at clearing human mesothelioma. Less effective CAR Th17 cells generated with high αCD3/ICOS beads were rescued by overexpressing phosphoenolpyruvate carboxykinase 1 (PCK1), a PEP regulator. Thus, Th17 therapy can be improved by using fewer activation beads during manufacturing, a finding that is cost effective and directly translatable to patients.
Topics: Animals; Humans; Mice; CD28 Antigens; Inducible T-Cell Co-Stimulator Protein; Interleukin-17; Lymphocyte Activation; Phosphoenolpyruvate; Receptors, Antigen, T-Cell; Receptors, Chimeric Antigen; Signal Transduction; Th17 Cells
PubMed: 37081789
DOI: 10.1016/j.ymthe.2023.04.010 -
Chemical Communications (Cambridge,... Nov 2023Aberrant PCK2 overexpression has been linked to an unfavorable prognosis and shorter survival, particularly in hepatocellular carcinoma (HCC). Thus, the inactivation of...
Aberrant PCK2 overexpression has been linked to an unfavorable prognosis and shorter survival, particularly in hepatocellular carcinoma (HCC). Thus, the inactivation of PCK2 provides a promising strategy for HCC treatment. In this study, we used a chemical genetic strategy to identify a natural-derived small-molecule cucurbitacin B (CuB) as a selective PCK2 inhibitor. CuB covalently bound to PCK2 at a unique Cys63 site, blocking the Ω-loop lid domain formation a previously undisclosed allosteric mechanism. Additionally, targeted lipidomics analysis also revealed that CuB destroyed mitochondrial membrane integrity, leading to the disruption of mitochondrial fusion-fission dynamics. Taken together, this study highlights the discovery of a small-molecule CuB, which reprograms lipid metabolism for controlling mitochondrial dynamics targeting PCK2 in cancer cells.
Topics: Humans; Carcinoma, Hepatocellular; Mitochondrial Dynamics; Liver Neoplasms; Allosteric Regulation; Phosphoenolpyruvate Carboxykinase (ATP)
PubMed: 37885376
DOI: 10.1039/d3cc02781c -
Endocrinology and Metabolism (Seoul,... Feb 2024Sodium-dependent glucose cotransporter 2 (SGLT2) mediates glucose reabsorption in the renal proximal tubules, and SGLT2 inhibitors are used as therapeutic agents for...
BACKGRUOUND
Sodium-dependent glucose cotransporter 2 (SGLT2) mediates glucose reabsorption in the renal proximal tubules, and SGLT2 inhibitors are used as therapeutic agents for treating type 2 diabetes mellitus. This study aimed to elucidate the effects and mechanisms of SGLT2 inhibition on hepatic glucose metabolism in both serum deprivation and serum supplementation states.
METHODS
Huh7 cells were treated with the SGLT2 inhibitors empagliflozin and dapagliflozin to examine the effect of SGLT2 on hepatic glucose uptake. To examine the modulation of glucose metabolism by SGLT2 inhibition under serum deprivation and serum supplementation conditions, HepG2 cells were transfected with SGLT2 small interfering RNA (siRNA), cultured in serum-free Dulbecco's modified Eagle's medium for 16 hours, and then cultured in media supplemented with or without 10% fetal bovine serum for 8 hours.
RESULTS
SGLT2 inhibitors dose-dependently decreased hepatic glucose uptake. Serum deprivation increased the expression levels of the gluconeogenesis genes peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), glucose 6-phosphatase (G6pase), and phosphoenolpyruvate carboxykinase (PEPCK), and their expression levels during serum deprivation were further increased in cells transfected with SGLT2 siRNA. SGLT2 inhibition by siRNA during serum deprivation induces nuclear localization of the transcription factor forkhead box class O 1 (FOXO1), decreases nuclear phosphorylated-AKT (p-AKT), and p-FOXO1 protein expression, and increases phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK) protein expression. However, treatment with the AMPK inhibitor, compound C, reversed the reduction in the protein expression levels of nuclear p- AKT and p-FOXO1 and decreased the protein expression levels of p-AMPK and PEPCK in cells transfected with SGLT2 siRNA during serum deprivation.
CONCLUSION
These data show that SGLT2 mediates glucose uptake in hepatocytes and that SGLT2 inhibition during serum deprivation increases gluconeogenesis via the AMPK/AKT/FOXO1 signaling pathway.
Topics: Humans; AMP-Activated Protein Kinases; Diabetes Mellitus, Type 2; Gluconeogenesis; Glucose; Phosphoenolpyruvate Carboxykinase (ATP); Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Sodium; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors
PubMed: 38171209
DOI: 10.3803/EnM.2023.1786 -
Frontiers in Plant Science 2023The content and proportion of sugars and acids in tomato fruit directly affect its flavor quality. Previous studies have shown that 5-aminolevulinic acid (ALA) could...
The content and proportion of sugars and acids in tomato fruit directly affect its flavor quality. Previous studies have shown that 5-aminolevulinic acid (ALA) could promote fruit ripening and improve its aroma quality. In order to explore the effect of ALA on sugar and acid quality during tomato fruit development, 0, 100, and 200 mg L ALA solutions were sprayed on the fruit surface 10 days after pollination of the fourth inflorescence, and the regulation of ALA on sugar, acid metabolism and flavor quality of tomato fruit was analyzed. The results showed that ALA treatment could enhance the activities of acid invertase (AI), neutral invertase (NI), and sucrose synthase (SS), reduce the activity of sucrose phosphate synthase (SPS), up-regulate the expression of , and , change the composition and content of sugar in tomato fruit at three stages, significantly increase the content of sugars in fruit, and promote the accumulation of sugars into flesh. Secondly, ALA treatments increased the activities of phosphoenolpyruvate carboxykinase (PEPC), malic enzyme (ME), and citrate synthase (CS), up-regulated the expression of , , and , and reduced the citric acid content at maturity stage, thereby reducing the total organic acid content. In addition, ALA could also increase the number and mass fraction of volatile components in mature tomato fruits. These results indicated that exogenous application of ALA during tomato fruit development could promote the formation of fruit aroma quality and were also conducive to the formation of fruit sugar and acid quality.
PubMed: 38186602
DOI: 10.3389/fpls.2023.1323048 -
Environment International May 2024Heavy metals are commonly released into the environment through industrial processes such as mining and refining. The rapid industrialization that occurred in South...
Heavy metals are commonly released into the environment through industrial processes such as mining and refining. The rapid industrialization that occurred in South Korea during the 1960s and 1970s contributed significantly to the economy of the country; however, the associated mining and refining led to considerable environmental pollution, and although mining is now in decline in South Korea, the detrimental effects on residents inhabiting the surrounding areas remain. The bioaccumulation of toxic heavy metals leads to metabolic alterations in human homeostasis, with disruptions in this balance leading to various health issues. This study used metabolomics to explore metabolomic alterations in the plasma samples of residents living in mining and refining areas. The results showed significant increases in metabolites involved in glycolysis and the surrounding metabolic pathways, such as glucose-6-phosphate, phosphoenolpyruvate, lactate, and inosine monophosphate, in those inhabiting polluted areas. An investigation of the associations between metabolites and blood clinical parameters through meet-in-the-middle analysis indicated that female residents were more affected by heavy metal exposure, resulting in more metabolomic alterations. For women, inhabiting the abandoned mine area, metabolites in the glycolysis and pentose phosphate pathways, such as ribose-5-phosphate and 3-phosphoglycerate, have shown a negative correlation with albumin and calcium. Finally, Mendelian randomization(MR) was used to determine the causal effects of these heavy metal exposure-related metabolites on heavy metal exposure-related clinical parameters. Metabolite biomarkers could provide insights into altered metabolic pathways related to exposure to toxic heavy metals and improve our understanding of the molecular mechanisms underlying the health effects of toxic heavy metal exposure.
Topics: Humans; Metals, Heavy; Female; Environmental Exposure; Republic of Korea; Male; Adult; Metabolomics; Mining; Middle Aged; Environmental Pollution; Environmental Pollutants
PubMed: 38723457
DOI: 10.1016/j.envint.2024.108709