Self-cascade MoS2 nanozymes for efficient intracellular antioxidation and hepatic fibrosis therapy

Nanoscale ◽  
2021 ◽  
Author(s):  
Xinyu Zhang ◽  
Shitong Zhang ◽  
Zaixing Yang ◽  
Zhuanghua Wang ◽  
Xin Tian ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Antioxidative Enzymes ◽  
Redox Homeostasis ◽  
Cellular Metabolism ◽  
Cascade Reactions ◽  
Living Cells

Cascade biocatalytic reactions involving multiple antioxidative enzymes are necessary in living cells to regulate cellular metabolism and redox homeostasis. Substantial efforts have been made to construct cascade reactions through engineered...

scholarly journals Mapping glycan-mediated galectin-3 interactions by live cell proximity labeling

2020 ◽  
Author(s):  
Eugene Joeh ◽  
Timothy O’Leary ◽  
Weichao Li ◽  
Richard Hawkins ◽  
Jonathan R. Hung ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Weak Interactions ◽  
Stellate Cell ◽  
Three Dimensional ◽  
Stellate Cells ◽  
Living Cells ◽  
Live Cells ◽  
Galectin 3

AbstractGalectin-3 is a glycan-binding protein (GBP) that binds β-galactoside glycan structures to orchestrate a variety of important biological events, including the activation of hepatic stellate cells to cause hepatic fibrosis. While the requisite glycan epitopes needed to bind galectin-3 have long been elucidated, the cellular glycoproteins that bear these glycan signatures remain unknown. Given the importance of the three-dimensional arrangement of glycans in dictating GBP interactions, strategies that allow the identification of GBP receptors in live cells, where the native glycan presentation and glycoprotein expression are preserved, possess significant advantages over static and artificial systems. Here, we describe the integration of a proximity labeling method and quantitative mass spectrometry to map the glycan and glycoprotein interactors for galectin-3 in live hepatic stellate cells. Understanding the identity of the glycoproteins and defining the structures of the glycans required for galectin-3 mediated hepatic stellate cell activation will empower efforts to design and develop selective therapeutics to mitigate hepatic fibrosis.SignificanceBecause of the weak interactions between individual glycan-binding proteins (GBP), such as galectin-3, and glycans, strategies that allow the direct interrogation of these interactions in living cells remain limited. Thus, the glycan and glycoprotein ligands that are physiologically relevant for galectin-3 binding are insufficiently described. Here, we used a proximity labeling approach that catalytically tags interactors for galectin-3 and identified its pertinent glycan and glycoprotein counter-receptors in live hepatic stellate cells. This study demonstrates that proximity labeling is a powerful tool for mapping GBP complexes in living cells, and when coupled with chemical inhibitors, it can discriminate between protein-protein and protein-glycan interactions.Graphical Abstract

scholarly journals Monitoring the Redox Status in Multiple Sclerosis

2020 ◽  
Author(s):  
Masaru Tanaka ◽  
László Vécsei
Keyword(s):  
Multiple Sclerosis ◽  
Antioxidative Enzymes ◽  
Degradation Products ◽  
Redox Homeostasis ◽  
Chemical Species ◽  
Redox Status ◽  
Antioxidative Enzyme ◽  
Postmortem Brain ◽  
Oxidative Enzymes ◽  
Related Factor

Worldwide, over 2.2 million people are suffered from multiple sclerosis (MS), a multifactorial demyelinating disease of the central nervous system. MS is characterized by multifocal inflammatory or demyelinating attacks associated with neuroinflammation and neurodegeneration. The blood, cerebrospinal fluid, and postmortem brain samples of MS patients evidenced the disturbance of reduction-oxidation (redox) homeostasis such as the alterations of oxidative and antioxidative enzyme activities and the presence of degradation products. This review article discussed the components of redox homeostasis including reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products. The reactive chemical species covered frequently discussed reactive oxygen/nitrogen species, infrequently featured reactive chemicals such as sulfur, carbonyl, halogen, selenium, and nucleophilic species that potentially act as reductive as well as pro-oxidative stressors. The antioxidative enzyme systems covered the nuclear factor erythroid-2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway. The NRF2 and other transcriptional factors potentially become a biomarker sensitive to the initial phase of oxidative stress. Altered components of the redox homeostasis in MS were discussed in search of a diagnostic, prognostic, predictive, and/or therapeutic biomarker. Finally, monitoring a battery of reactive chemical species, oxidative enzymes, antioxidative enzymes and degradation products helps evaluate the redox status of MS patients, expediting prolongation of remission, prevention of relapse, and thus building personalized treatment plans.

scholarly journals Elucidation of interfacial pH behaviour at the cell/substrate nanogap for in situ monitoring of cellular respiration

Nanoscale ◽  
2018 ◽  
Vol 10 (21) ◽  
pp. 10130-10136 ◽  
Author(s):  
Hiroto Satake ◽  
Akiko Saito ◽  
Toshiya Sakata
Keyword(s):  
Cellular Metabolism ◽  
Living Cells ◽  
In Situ Monitoring ◽  
Cellular Respiration ◽  
Cell Substrate

In situ monitoring of cellular metabolism is useful for elucidating dynamic functions of living cells.

Coumarin-based fluorescence sensor for rapid discrimination of cysteine/homocysteine and glutathione under dual excitation wavelengths.

The Analyst ◽  
2021 ◽  
Author(s):  
Jianbin Chao ◽  
Jiamin Zhao ◽  
Yongbin Zhang ◽  
Fangjun Huo ◽  
Caixia Yin
Keyword(s):  
Molecular Structure ◽  
Redox Homeostasis ◽  
Living Cells ◽  
Fluorescence Sensor ◽  
Rapid Discrimination

Biological thiols (Cys, Hcy and GSH) are crucial biomolecules in living cells and play indispensable roles in maintaining the redox homeostasis of organisms. But due to their similar molecular structure,...

scholarly journals Understanding and Eliminating the Detrimental Effect of Thiamine Deficiency on the Oleaginous Yeast Yarrowia lipolytica

2019 ◽  
Vol 86 (3) ◽  
Author(s):  
Caleb Walker ◽  
Seunghyun Ryu ◽  
Richard J. Giannone ◽  
Sergio Garcia ◽  
Cong T. Trinh
Keyword(s):  
Energy Metabolism ◽  
Yarrowia Lipolytica ◽  
Thiamine Deficiency ◽  
Oleaginous Yeast ◽  
De Novo ◽  
Lipid Production ◽  
Cellular Metabolism ◽  
Living Cells ◽  
Lipid Biosynthesis ◽  
Content Type

ABSTRACT Thiamine is a vitamin that functions as a cofactor for key enzymes in carbon and energy metabolism in all living cells. While most plants, fungi, and bacteria can synthesize thiamine de novo, the oleaginous yeast Yarrowia lipolytica cannot. In this study, we used proteomics together with physiological characterization to elucidate key metabolic processes influenced and regulated by thiamine availability and to identify the genetic basis of thiamine auxotrophy in Y. lipolytica. Specifically, we found that thiamine depletion results in decreased protein abundance for the lipid biosynthesis pathway and energy metabolism (i.e., ATP synthase), leading to the negligible growth and poor sugar assimilation observed in our study. Using comparative genomics, we identified the missing 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase (THI13) gene for the de novo thiamine biosynthesis in Y. lipolytica and discovered an exceptional promoter, P3, that exhibits strong activation and tight repression by low and high thiamine concentrations, respectively. Capitalizing on the strength of our thiamine-regulated promoter (P3) to express the missing gene from Saccharomyces cerevisiae (scTHI13), we engineered a thiamine-prototrophic Y. lipolytica strain. By comparing this engineered strain to the wild-type strain, we revealed the tight relationship between thiamine availability and lipid biosynthesis and demonstrated enhanced lipid production with thiamine supplementation in the engineered thiamine-prototrophic Y. lipolytica strain. IMPORTANCE Thiamine plays a crucial role as an essential cofactor for enzymes involved in carbon and energy metabolism in all living cells. Thiamine deficiency has detrimental consequences for cellular health. Yarrowia lipolytica, a nonconventional oleaginous yeast with broad biotechnological applications, is a native thiamine auxotroph whose affected cellular metabolism is not well understood. Therefore, Y. lipolytica is an ideal eukaryotic host for the study of thiamine metabolism, especially because mammalian cells are also thiamine auxotrophic and thiamine deficiency is implicated in several human diseases. This study elucidates the fundamental effects of thiamine deficiency on cellular metabolism in Y. lipolytica and identifies genes and novel thiamine-regulated elements that eliminate thiamine auxotrophy in Y. lipolytica. Furthermore, the discovery of thiamine-regulated elements enables the development of thiamine biosensors with useful applications in synthetic biology and metabolic engineering.

scholarly journals Monitoring the Redox Status in Multiple Sclerosis

Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 406 ◽  
Author(s):  
Masaru Tanaka ◽  
László Vécsei
Keyword(s):  
Multiple Sclerosis ◽  
Antioxidative Enzymes ◽  
Degradation Products ◽  
Redox Homeostasis ◽  
Chemical Species ◽  
Redox Status ◽  
Antioxidative Enzyme ◽  
Oxidative Enzymes ◽  
Related Factor ◽  
Wide Range

Worldwide, over 2.2 million people suffer from multiple sclerosis (MS), a multifactorial demyelinating disease of the central nervous system. MS is characterized by a wide range of motor, autonomic, and psychobehavioral symptoms, including depression, anxiety, and dementia. The blood, cerebrospinal fluid, and postmortem brain samples of MS patients provide evidence on the disturbance of reduction-oxidation (redox) homeostasis, such as the alterations of oxidative and antioxidative enzyme activities and the presence of degradation products. This review article discusses the components of redox homeostasis, including reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products. The reactive chemical species cover frequently discussed reactive oxygen/nitrogen species, infrequently featured reactive chemicals such as sulfur, carbonyl, halogen, selenium, and nucleophilic species that potentially act as reductive, as well as pro-oxidative stressors. The antioxidative enzyme systems cover the nuclear factor erythroid-2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway. The NRF2 and other transcriptional factors potentially become a biomarker sensitive to the initial phase of oxidative stress. Altered components of the redox homeostasis in MS were discussed in search of a diagnostic, prognostic, predictive, and/or therapeutic biomarker. Finally, monitoring the battery of reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products helps to evaluate the redox status of MS patients to expedite the building of personalized treatment plans for the sake of a better quality of life.

scholarly journals Understanding and eliminating the detrimental effect of endogenous thiamine auxotrophy on metabolism of the oleaginous yeast Yarrowia lipolytica

2019 ◽  
Author(s):  
Caleb Walker ◽  
Seunghyun Ryu ◽  
Richard J. Giannone ◽  
Sergio Garcia ◽  
Cong T. Trinh
Keyword(s):  
Energy Metabolism ◽  
Yarrowia Lipolytica ◽  
Thiamine Deficiency ◽  
Oleaginous Yeast ◽  
De Novo ◽  
Lipid Production ◽  
Cellular Metabolism ◽  
Living Cells ◽  
Lipid Biosynthesis ◽  
Missing Gene

ABSTRACTThiamine is an essential vitamin that functions as a cofactor for key enzymes in carbon and energy metabolism for all living cells. While most plants, fungi and bacteria can synthesize thiamine de novo, the oleaginous yeast, Yarrowia lipolytica, cannot. In this study, we used proteomics together with physiological characterization to understand key metabolic processes influenced and regulated by thiamine availability and identified the genetic basis of thiamine auxotrophy in Y. lipolytica. Specifically, we found thiamine depletion results in decreased protein abundance of the lipid biosynthesis pathways and energy metabolism (i.e., ATP synthase), attributing to the negligible growth and poor sugar assimilation observed in our study. Using comparative genomics, we identified the missing gene scTHI13, encoding the 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase for the de novo thiamine synthesis in Y. lipolytica, and discovered an exceptional promoter, P3, that exhibits strong activation or tight repression by low and high thiamine concentrations, respectively. Capitalizing on the strength of our thiamine-regulated promoter (P3) to express the missing gene, we engineered the first thiamine-prototrophic Y. lipolytica reported to date. By comparing this engineered strain to the wildtype, we unveiled the tight relationship linking thiamine availability to lipid biosynthesis and demonstrated enhanced lipid production with thiamine supplementation in the engineered thiamine-prototrophic Y. lipolytica.IMPORTANCEThiamine plays a crucial role as an essential cofactor for enzymes in carbon and energy metabolism of all living cells. Thiamine deficiency has detrimental consequences on cellular health. Yarrowia lipolytica, a non-conventional oleaginous yeast with broad biotechnological applications, is a native thiamine auxotroph, whose effects on cellular metabolism are not well understood. Therefore, Y. lipolytica is an ideal eukaryotic host to study thiamine metabolism, especially as mammalian cells are also thiamine-auxotrophic and thiamine deficiency is implicated in several human diseases. This study elucidates the fundamentals of thiamine deficiency on cellular metabolism of Y. lipolytica and identifies genes and novel thiamine-regulated elements that eliminate thiamine auxotrophy in Y. lipolytica. Furthermore, discovery of thiamine-regulated elements enables development of thiamine biosensors with useful applications in synthetic biology and metabolic engineering.

scholarly journals A Fast-Response Red Shifted Fluorescent Probe for Detection of H2S in Living Cells

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 437 ◽  
Author(s):  
Ismail Ismail ◽  
Zhuoyue Chen ◽  
Xiuru Ji ◽  
Lu Sun ◽  
Long Yi ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Near Infrared ◽  
Redox Homeostasis ◽  
Fast Response ◽  
Living Cells ◽  
Live Cells ◽  
Minimal Damage ◽  
Auto Fluorescence ◽  
Mitochondria Targeting

Near-infrared (NIR) fluorescent probes are attractive tools for bioimaging applications because of their low auto-fluorescence interference, minimal damage to living samples, and deep tissue penetration. H2S is a gaseous signaling molecule that is involved in redox homeostasis and numerous biological processes in vivo. To this end, we have developed a new red shifted fluorescent probe 1 to detect physiological H2S in live cells. The probe 1 is based on a rhodamine derivative as the red shifted fluorophore and the thiolysis of 7-nitro 1,2,3-benzoxadiazole (NBD) amine as the H2S receptor. The probe 1 displays fast fluorescent enhancement at 660 nm (about 10-fold turn-ons, k2 = 29.8 M−1s−1) after reacting with H2S in buffer (pH 7.4), and the fluorescence quantum yield of the activated red shifted product can reach 0.29. The probe 1 also exhibits high selectivity and sensitivity towards H2S. Moreover, 1 is cell-membrane-permeable and mitochondria-targeting, and can be used for imaging of endogenous H2S in living cells. We believe that this red shifted fluorescent probe can be a useful tool for studies of H2S biology.

scholarly journals Monitoring the Redox Status in Multiple Sclerosis

2020 ◽  
Author(s):  
Masaru Tanaka ◽  
László Vécsei
Keyword(s):  
Multiple Sclerosis ◽  
Antioxidative Enzymes ◽  
Degradation Products ◽  
Redox Homeostasis ◽  
Chemical Species ◽  
Redox Status ◽  
Antioxidative Enzyme ◽  
Oxidative Enzymes ◽  
Related Factor ◽  
Wide Range

Worldwide, over 2.2 million people are suffered from multiple sclerosis (MS), a multifactorial demyelinating disease of the central nervous system. MS is characterized by a wide range of motor, autonomic, and psychobehavioral symptoms including depression, anxiety, and dementia. The blood, cerebrospinal fluid, and postmortem brain samples of MS patients evidenced the disturbance of reduction-oxidation (redox) homeostasis such as the alterations of oxidative and antioxidative enzyme activities and the presence of degradation products. This review article discussed the components of redox homeostasis including reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products. The reactive chemical species covered frequently discussed reactive oxygen/nitrogen species, infrequently featured reactive chemicals such as sulfur, carbonyl, halogen, selenium, and nucleophilic species that potentially act as reductive as well as pro-oxidative stressors. The antioxidative enzyme systems covered the nuclear factor erythroid-2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway. The NRF2 and other transcriptional factors potentially become a biomarker sensitive to the initial phase of oxidative stress. Altered components of the redox homeostasis in MS were discussed in search of a diagnostic, prognostic, predictive, and/or therapeutic biomarker. Finally, monitoring a battery of reactive chemical species, oxidative enzymes, antioxidative enzymes and degradation products helps evaluate the redox status of MS patients to expedite building personalized treatment plans for the sake of better quality of life.

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