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Kaempferol increases intracellular ATP content in C 2C 12 myotubes under hypoxic conditions by suppressing the HIF-1α stabilization and/or by enhancing the mitochondrial complex IV activity. J Nutr Biochem 2022; 103:108949. [PMID: 35122998 DOI: 10.1016/j.jnutbio.2022.108949] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/28/2021] [Accepted: 01/04/2022] [Indexed: 10/19/2022]
Abstract
Kaempferol (KMP) has numerous important biological functions, and we recently showed that it remarkably increased intracellular adenosine triphosphate (ATP) content in C2C12 myotubes under hypoxic conditions. Since intracellular ATP is generated by aerobic energy metabolism or anaerobic glycolysis, hypoxia inducible factor-1α (HIF-1α) has been shown to be associated with metabolic remodeling and causes metabolic shift from aerobic energy metabolism to anaerobic glycolysis in response to hypoxic conditions. Here, we investigate the effects of KMP under hypoxic conditions on the stabilization of HIF-1α in C2C12 myotubes and its underlying molecular mechanisms. Constitutive HIF-1α protein expression was observed in C2C12 myotubes, and its expression under hypoxic conditions was remarkably suppressed by KMP by reducing its stability; thus, resulting in an increase in ATP content. Furthermore, KMP strikingly increased the ubiquitination of HIF-1α and promoted its degradation via the ubiquitin proteasome system. Inhibition of HIF-1α by KMP resulted in the abrogation of the expression of glycolytic enzymes such as lactate dehydrogenase A and pyruvate dehydrogenase kinase isozyme 1. In addition, the metabolome profiling showed that KMP promoted oxidative energy production, while the mitochondrial complex activity assay indicated that KMP increased the activity of mitochondrial complex IV. Finally, we showed that KMP inhibited HIF-1α expression and increased intracellular ATP content in the soleus muscle of rats. Taken together, these results suggest that KMP increases intracellular ATP content under hypoxic conditions by suppressing the HIF-1α stabilization and/or by enhancing the mitochondrial complex IV activity in muscle.
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Key Words
- 2-OG, 2-oxoglutaric acid
- 3-PG, 3-phosphoglyceric acid
- ADP, adenosine diphosphate
- ATP, adenosine triphosphate
- AcCoA, acetyl CoA
- C(2)C(12) myotube
- CE-TOFMS, capillary electrophoresis time-of-flight mass spectrometry
- CHX, cycloheximide
- DFO, deferoxamine mesylate
- DMEM, Dulbecco's modified Eagle medium
- DMSO, dimethylsulfoxide
- EGCG, epigallocatechin gallate
- F1,6P, fructose-1,6-bisphosphate
- F6P, fructose-6-phosphate
- FAD, flavin adenine dinucleotide
- FBS, fetal bovine serum
- G6P, glucose-6-phosphate
- GAP, glyceraldehyde-3-phosphate
- HIF, hypoxia inducible factor
- HIF-1α, hypoxia
- HRE, hypoxia response element
- HS, horse serum
- HSP, heat shock protein
- KMP, kaempferol
- LDHA, lactate dehydrogenase A
- Lac, lactacystin
- NAD, nicotinamide adenine dinucleotide
- PBS, phosphate-buffered saline
- PDH, pyruvate dehydrogenase
- PDK1, pyruvate dehydrogenase kinase isozyme 1
- PEP, phosphoenolpyruvic acid
- PHD, prolyl hydroxylase
- RACK, receptor for activated C kinase
- RT-qPCR, reverse transcription-quantitative polymerase chain reaction
- TCA, tricarboxylic acid
- Ub, ubiquitin
- VHL, von Hippel–Lindau
- kaempferol
- metabolome profiling
- mitochondria
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2
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Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls. Acta Pharm Sin B 2021; 11:3740-3755. [PMID: 35024303 PMCID: PMC8727921 DOI: 10.1016/j.apsb.2021.09.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/22/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, which is safe at therapeutic doses but can cause severe liver injury and even liver failure after overdoses. The mouse model of APAP hepatotoxicity recapitulates closely the human pathophysiology. As a result, this clinically relevant model is frequently used to study mechanisms of drug-induced liver injury and even more so to test potential therapeutic interventions. However, the complexity of the model requires a thorough understanding of the pathophysiology to obtain valid results and mechanistic information that is translatable to the clinic. However, many studies using this model are flawed, which jeopardizes the scientific and clinical relevance. The purpose of this review is to provide a framework of the model where mechanistically sound and clinically relevant data can be obtained. The discussion provides insight into the injury mechanisms and how to study it including the critical roles of drug metabolism, mitochondrial dysfunction, necrotic cell death, autophagy and the sterile inflammatory response. In addition, the most frequently made mistakes when using this model are discussed. Thus, considering these recommendations when studying APAP hepatotoxicity will facilitate the discovery of more clinically relevant interventions.
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Key Words
- AIF, apoptosis-inducing factor
- AMPK, AMP-activated protein kinase
- APAP, acetaminophen
- ARE, antioxidant response element
- ATG, autophagy-related genes
- Acetaminophen hepatotoxicity
- Apoptosis
- Autophagy
- BSO, buthionine sulfoximine
- CAD, caspase-activated DNase
- CYP, cytochrome P450 enzymes
- DAMPs, damage-associated molecular patterns
- DMSO, dimethylsulfoxide
- Drug metabolism
- EndoG, endonuclease G
- FSP1, ferroptosis suppressing protein 1
- Ferroptosis
- GPX4, glutathione peroxidase 4
- GSH, glutathione
- GSSG, glutathione disulfide
- Gclc, glutamate–cysteine ligase catalytic subunit
- Gclm, glutamate–cysteine ligase modifier subunit
- HMGB1, high mobility group box protein 1
- HNE, 4-hydroxynonenal
- Innate immunity
- JNK, c-jun N-terminal kinase
- KEAP1, Kelch-like ECH-associated protein 1
- LAMP, lysosomal-associated membrane protein
- LC3, light chain 3
- LOOH, lipid hydroperoxides
- LPO, lipid peroxidation
- MAP kinase, mitogen activated protein kinase
- MCP-1, monocyte chemoattractant protein-1
- MDA, malondialdehyde
- MPT, mitochondrial permeability transition
- Mitochondria
- MnSOD, manganese superoxide dismutase
- NAC, N-acetylcysteine
- NAPQI, N-acetyl-p-benzoquinone imine
- NF-κB, nuclear factor κB
- NQO1, NAD(P)H:quinone oxidoreductase 1
- NRF2
- NRF2, nuclear factor erythroid 2-related factor 2
- PUFAs, polyunsaturated fatty acids
- ROS, reactive oxygen species
- SMAC/DIABLO, second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI
- TLR, toll like receptor
- TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling
- UGT, UDP-glucuronosyltransferases
- mTORC1, mammalian target of rapamycin complex 1
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First small-molecule PROTACs for G protein-coupled receptors: inducing α 1A-adrenergic receptor degradation. Acta Pharm Sin B 2020; 10:1669-1679. [PMID: 33088687 PMCID: PMC7563999 DOI: 10.1016/j.apsb.2020.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/18/2019] [Accepted: 12/26/2019] [Indexed: 12/12/2022] Open
Abstract
Proteolysis targeting chimeras (PROTACs) are dual-functional hybrid molecules that can selectively recruit an E3 ubiquitin ligase to a target protein to direct the protein into the ubiquitin-proteasome system (UPS), thereby selectively reducing the target protein level by the ubiquitin-proteasome pathway. Nowadays, small-molecule PROTACs are gaining popularity as tools to degrade pathogenic protein. Herein, we present the first small-molecule PROTACs that can induce the α1A-adrenergic receptor (α1A-AR) degradation, which is also the first small-molecule PROTACs for G protein-coupled receptors (GPCRs) to our knowledge. These degradation inducers were developed through conjugation of known α1-adrenergic receptors (α1-ARs) inhibitor prazosin and cereblon (CRBN) ligand pomalidomide through the different linkers. The representative compound 9c is proved to inhibit the proliferation of PC-3 cells and result in tumor growth regression, which highlighted the potential of our study as a new therapeutic strategy for prostate cancer.
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Key Words
- BPH, benign prostatic hyperplasia
- CRBN, cereblon
- DCM, dichloromethane
- DMF, dimethylformamide
- DMSO, dimethylsulfoxide
- Degradation
- GPCR, G-protein-coupled receptor
- HPLC, high-performance liquid chromatography
- LUTS, lower urinary tract symptoms
- PROTACs, proteolysis targeting chimeras
- Prostate cancer
- Small-molecule PROTACs
- TEA, triethylamine
- THF, tetrahydrofuran
- Ubiquitylation
- hPCE, human prostate cancer epithelial
- α1-ARs, α1-adrenergic receptors
- α1A-AR, α1A-adrenergic receptor
- α1A-Adrenergic receptor
- α1B-AR, α1B-adrenergic receptor
- α1D-AR, α1D-adrenergic receptor
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Identification of a novel PAK1 inhibitor to treat pancreatic cancer. Acta Pharm Sin B 2020; 10:603-614. [PMID: 32322465 PMCID: PMC7161699 DOI: 10.1016/j.apsb.2019.11.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 10/09/2019] [Accepted: 10/15/2019] [Indexed: 12/24/2022] Open
Abstract
Pancreatic cancer is one of the most aggressive cancers with poor prognosis and a low 5-year survival rate. The family of P21-activated kinases (PAKs) appears to modulate many signaling pathways that contribute to pancreatic carcinogenesis. In this work, we demonstrated that PAK1 is a critical regulator in pancreatic cancer cell growth. PAK1-targeted inhibition is therefore a new potential therapeutic strategy for pancreatic cancer. Our small molecule screening identified a relatively specific PAK1-targeted inhibitor, CP734. Pharmacological and biochemical studies indicated that CP734 targets residue V342 of PAK1 to inhibit its ATPase activity. Further in vitro and in vivo studies elucidated that CP734 suppresses pancreatic tumor growth through depleting PAK1 kinase activity and its downstream signaling pathways. Little toxicity of CP734 was observed in murine models. Combined with gemcitabine or 5-fluorouracil, CP734 also showed synergistic effects on the anti-proliferation of pancreatic cancer cells. All these favorable results indicated that CP734 is a new potential therapeutic candidate for pancreatic cancer.
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Key Words
- 5-FU, 5-fluorouracil
- ALP, alkaline phosphatase
- ALT, alanine aminotransferase
- ANOVA, analysis of variance
- AST, aspartate aminotransferase
- BCL-2, B-cell lymphoma-2
- BUN, blood urea nitrogen
- CCK-8, cell counting kit-8
- CDC42, cell division cycle 42
- DMEM, Dulbecco's modified Eagle's medium
- DMSO, dimethylsulfoxide
- ERK, extracellular regulated protein kinase
- GEPIA, gene expression profiling interactive analysis
- GTEx, genotype-tissue expression
- Gem, gemcitabine
- HEK293, human embryonic kidney 293
- HTVS, high-throughput virtual screening
- IMEM, improved minimum essential medium
- IP, immunoprecipitation
- Inhibitor
- MEK, mitogen-activated protein kinase kinase
- MEM, modified Eagle's medium
- NSCLC, non-small cell lung cancer
- OHP, oxaliplatin
- OS, overall survival
- PAK, P21-activated kinase
- PAK1
- PARP, poly(ADP-ribose) polymerase
- PAX, paclitaxel
- PSCs, pancreatic stellate cells
- PUMA, P53 upregulated modulator of apoptosis
- PVDF, polyvinylidene fluoride
- Pancreatic cancer
- RAC1, Rac family small GTPase 1
- RIPA, radio immunoprecipitation assay
- RPMI1640, Roswell Park Memorial Institute 1640 medium
- SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- SP, standard precision
- Structure-based virtual screening
- Synergistic effect
- TCGA, The Cancer Genome Atlas
- TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling
- XP, extra precision
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Novel radioligands for imaging sigma-1 receptor in brain using positron emission tomography (PET). Acta Pharm Sin B 2019; 9:1204-1215. [PMID: 31867166 PMCID: PMC6900558 DOI: 10.1016/j.apsb.2019.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 06/28/2019] [Accepted: 07/04/2019] [Indexed: 12/18/2022] Open
Abstract
The sigma-1 receptor (σ1R) is a unique intracellular protein. σ1R plays a major role in various pathological conditions in the central nervous system (CNS), implicated in several neuropsychiatric disorders. Imaging of σ1R in the brain using positron emission tomography (PET) could serve as a noninvasively tool for enhancing the understanding of the disease's pathophysiology. Moreover, σ1R PET tracers can be used for target validation and quantification in diagnosis. Herein, we describe the radiosynthesis, in vivo PET/CT imaging of novel σ1R 11C-labeled radioligands based on 6-hydroxypyridazinone, [11C]HCC0923 and [11C]HCC0929. Two radioligands have high affinities to σ1R, with good selectivity. In mice PET/CT imaging, both radioligands showed appropriate kinetics and distributions. Additionally, the specific interactions of two radioligands were reduced by compounds 13 and 15 (self-blocking). Of the two, [11C]HCC0929 was further investigated in positive ligands blocking studies, using classic σ1R agonist SA 4503 and σ1R antagonist PD 144418. Both σ1R ligands could extensively decreased the uptake of [11C]HCC0929 in mice brain. Besides, the biodistribution of major brain regions and organs of mice were determined in vivo. These studies demonstrated that two radioligands, especially [11C]HCC0929, possessed ideal imaging properties and might be valuable tools for non-invasive quantification of σ1R in brain.
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Key Words
- 11C-labeled radioligand
- 3D, three-dimensional
- 6-Hydroxypyridazinone
- AF, ammonium formate
- BBB, brain blood barrier
- BP, binding potential
- Brain imaging
- CNS, center nervous systems
- CRPS, complex regional pain syndrome
- DMF, dimethyl formamide
- DMSO, dimethylsulfoxide
- ER, endoplasmic reticulum
- LCP, lipidic cubic phase
- MAM, mitochondria-associated ER membrane
- PCP, phencyclidine
- PET
- PET, positron emission tomography
- TFA, trifluoroacetic acid
- σ1R
- σ1R, sigma-1 receptor
- σ2R, sigma-2 receptor
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Orthogonal assays for the identification of inhibitors of the single-stranded nucleic acid binding protein YB-1. Acta Pharm Sin B 2019; 9:997-1007. [PMID: 31649849 PMCID: PMC6804448 DOI: 10.1016/j.apsb.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 02/01/2023] Open
Abstract
We have previously shown that high expression of the nucleic acid binding factor YB-1 is strongly associated with poor prognosis in a variety of cancer types. The 3-dimensional protein structure of YB-1 has yet to be determined and its role in transcriptional regulation remains elusive. Drug targeting of transcription factors is often thought to be difficult and there are very few published high-throughput screening approaches. YB-1 predominantly binds to single-stranded nucleic acids, adding further difficulty to drug discovery. Therefore, we have developed two novel screening assays to detect compounds that interfere with the transcriptional activation properties of YB-1, both of which may be generalizable to screen for inhibitors of other nucleic acid binding molecules. The first approach is a cell-based luciferase reporter gene assay that measures the level of activation of a fragment of the E2F1 promoter by YB-1. The second approach is a novel application of the AlphaScreen system, to detect interference of YB-1 interaction with a single-stranded DNA binding site. These complementary assays examine YB-1 binding to two discrete nucleic acid sequences using two different luminescent signal outputs and were employed sequentially to screen 7360 small molecule compounds leading to the identification of three putative YB-1 inhibitors.
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Key Words
- AlphaScreen
- CSD, cold shock domain
- CTD, C-terminal domain
- Cancer
- DMSO, dimethylsulfoxide
- E2F1, E2F transcription factor 1
- EGR1, early growth response 1
- HTS, high-throughput screening
- Luciferase
- NTD, N-terminal domain
- Single-stranded DNA
- Transcription factor
- YB-1
- YB-1, Y-box binding protein-1
- YBX1, Y-box binding protein gene 1
- cDNA, complementary DNA
- dsDNA, double-stranded DNA
- shRNA, short-hairpin RNA
- siRNA, small-interfering RNA
- ssDNA, single-stranded DNA
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Novel fluorescent probes of 10-hydroxyevodiamine: autophagy and apoptosis-inducing anticancer mechanisms. Acta Pharm Sin B 2019; 9:144-156. [PMID: 30766786 PMCID: PMC6361730 DOI: 10.1016/j.apsb.2018.08.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/25/2018] [Accepted: 08/05/2018] [Indexed: 12/21/2022] Open
Abstract
Natural product evodiamine and its derivatives represent a promising class of multi-target antitumor agents. However, the clinical development of these compounds has been hampered by a poor understanding of their antitumor mechanisms. To tackle this obstacle, herein, novel fluorescent probes were designed to elucidate the antitumor mode of action of 10-hydroxyevodiamine. This compound was proven to be distributed in the mitochondria and lysosomes and to act by autophagy and apoptosis mechanisms.
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Key Words
- 10-Hydroxyevodiamine
- 3MA, 3-methyladenine
- Anticancer mechanisms
- Apoptosis
- Autophagy
- Boc, di-tert-butyl dicarbonate
- CCK8, cell counting kit-8
- DMAP, 4-dimethylaminopyridine
- DMSO, dimethylsulfoxide
- EDC, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride
- Fluorescent probes
- HBTU, O-benzotriazole-N,N,N,N-tetramethyl-uronium-hexafluorophosphate
- MMP, mitochondrial membrane potential
- NPs, natural products
- TEA, trimethylamine
- TFA, trifluoroacetic acid
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Effects of endosulfan isomers on cytokine and nitric oxide production by differentially activated RAW 264.7 cells. Toxicol Rep 2018; 5:396-400. [PMID: 29765866 PMCID: PMC5949890 DOI: 10.1016/j.toxrep.2018.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/22/2018] [Accepted: 03/05/2018] [Indexed: 01/08/2023] Open
Abstract
Non-cytotoxic concentrations of endosulfan suppressed NO production. Suppression of NO was a more sensitive endpoint than suppression of TNF. Endosulfan alpha had greater cytotoxic potency than endosulfan beta.
Endosulfan is an organochlorine insecticide comprised of two isomers: endosulfan-α and endosulfan-β. Endosulfan exposure has been shown to elevate some inflammatory factors, such as nitric oxide (NO) and tumor necrosis factor (TNF), in animals or cultures of animal cells. Because the two endosulfan isomers can vary in their biological activities, the goal of this study was to determine if individual endosulfan isomers differentially impact production of NO or TNF by the mouse macrophage cell RAW 264.7 at non-cytotoxic levels. We found elevated TNF with exposure to endosulfan-α (not endosulfan-β), but only at concentrations that were cytotoxic (≥100 μM), whereas neither endosulfan isomer altered baseline levels of NO at any concentration up to 300 μM. In interferon (IFN)-γ-activated cultures, NO levels were significantly suppressed by either endosulfan isomer at 10 μM (the lowest concentration examined), whereas only endosulfan-β significantly lowered TNF levels at non-cytotoxic concentrations. In lipopolysaccharide (LPS)-activated cultures, both endosulfan isomers significantly reduced NO, but not TNF, at non-cytotoxic concentrations. These results suggest that the endosulfan isomers have some capacity to alter inflammatory responses differentially, particularly with IFN-γ stimulation.
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Key Words
- AP-1, activator protein 1
- DMSO, dimethylsulfoxide
- ER, estrogen receptor
- Endosulfan
- IFN, interferon
- IL, interleukin
- Inflammation
- LPS, lipopolysaccharide
- Macrophage
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NO, nitric oxide
- NOS2, nitric oxide synthase type 2
- Nitric oxide
- PAMP, pathogen-associated molecular pattern
- STAT, signal transducer and activator of transcription
- TNF
- TNF, tumor necrosis factor
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131I-Evans blue: evaluation of necrosis targeting property and preliminary assessment of the mechanism in animal models. Acta Pharm Sin B 2018; 8:390-400. [PMID: 29881678 PMCID: PMC5989829 DOI: 10.1016/j.apsb.2017.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/18/2017] [Accepted: 08/05/2017] [Indexed: 01/28/2023] Open
Abstract
Necrosis is a form of cell death, which is related to various serious diseases such as cardiovascular disease, cancer, and neurodegeneration. Necrosis-avid agents (NAAs) selectively accumulated in the necrotic tissues can be used for imaging and/or therapy of related diseases. The aim of this study was to preliminarily investigate necrosis avidity of 131I-evans blue (131I-EB) and its mechanism. The biodistribution of 131I-EB at 24 h after intravenous administration showed that the radioactivity ratio of necrotic to viable tissue was 3.41 in the liver and 11.82 in the muscle as determined by γ counting in model rats. Autoradiography and histological staining displayed preferential uptake of 131I-EB in necrotic tissues. In vitro nuclear extracts from necrotic cells exhibited 82.3% of the uptake in nuclei at 15 min, as well as 79.2% of the uptake at 2 h after 131I-EB incubation. The DNA binding study demonstrated that evans blue (EB) has strong binding affinity with calf-thymus DNA (CT-DNA) (Ksv=5.08×105 L/(mol/L)). Furthermore, the accumulation of 131I-EB in necrotic muscle was efficiently blocked by an excess amount of unlabeled EB. In conclusion, 131I-EB can not only detect necrosis by binding the DNA released from necrotic cells, but also image necrotic tissues generated from the disease clinically.
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Key Words
- % ID/g, percentage of the injected dose per gram of tissue
- 131I-EB, 131I-evans blue
- 131I-Evans blue
- CE-T1WI, contrast-enhanced T1WI
- CT-DNA, calf-thymus DNA
- DMSO, dimethylsulfoxide
- DNA binding
- DWI, diffusion-weighted imaging
- EB, evans blue
- H&E, haematoxylin-eosin
- Hyp, hypericin
- MPS, mononuclear phagocyte system
- MRI, magnetic resonance imaging
- NAAs, necrosis-avid agents
- Necrosis avidity
- Necrosis imaging
- PI, propidium iodide
- RCP, radiochemical purity
- RFA, radiofrequency ablation
- RPLI, reperfused liver infarction
- Radioactivity
- SD rats, Sprague–Dawley rats
- T1WI, T1-weighted imaging
- T2WI, T2-weighted imaging
- TLC, thin layer chromatography
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Qingfei Xiaoyan Wan, a traditional Chinese medicine formula, ameliorates Pseudomonas aeruginosa-induced acute lung inflammation by regulation of PI3K/AKT and Ras/MAPK pathways. Acta Pharm Sin B 2016; 6:212-21. [PMID: 27175332 PMCID: PMC4856955 DOI: 10.1016/j.apsb.2016.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/04/2016] [Accepted: 02/22/2016] [Indexed: 12/27/2022] Open
Abstract
Gram-negative pathogen–induced nosocomial infections and resistance are a most serious menace to global public health. Qingfei Xiaoyan Wan (QF), a traditional Chinese medicine (TCM) formula, has been used clinically in China for the treatment of upper respiratory tract infections, acute or chronic bronchitis and pulmonary infection. In this study, the effects of QF on Pseudomonas aeruginosa–induced acute pneumonia in mice were evaluated. The mechanisms by which four typical anti-inflammatory ingredients from QF, arctigenin (ATG), cholic acid (CLA), chlorogenic acid (CGA) and sinapic acid (SPA), regulate anti-inflammatory signaling pathways and related targets were investigated using molecular biology and molecular docking techniques. The results showed that pretreatment with QF significantly inhibits the release of cytokines (TNF-α and IL-6) and chemokines (IL-8 and RANTES), reduces leukocytes recruitment into inflamed tissues and ameliorates pulmonary edema and necrosis. In addition, ATG was identified as the primary anti-inflammatory agent with action on the PI3K/AKT and Ras/MAPK pathways. CLA and CGA enhanced the actions of ATG and exhibited synergistic NF-κB inactivation effects possibly via the Ras/MAPK signaling pathway. Moreover, CLA is speculated to target FGFR and MEK firstly. Overall, QF regulated the PI3K/AKT and Ras/MAPK pathways to inhibit pathogenic bacterial infections effectively.
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Key Words
- ATG, arctigenin
- Anti-inflammatory
- CGA, chlorogenic acid
- CLA, cholic acid
- DMSO, dimethylsulfoxide
- Dex, dexamethasone
- ELISA, enzyme-linked immunosorbent assay
- ESI, electrospray ionization
- GA, genetic algorithm
- HE, hematoxylin and eosin
- KEGG, Kyoto Encyclopedia of Genes and Genomes
- LB, Luria–Bertani
- LEV, levofloxacin
- Lung
- MAPK, mitogen activated protein kinase
- Mouse
- NFATc1, nuclear factor of activated T cells c1
- Network pharmacology
- Ninj1, ninjurin1
- PBS, phosphate-buffered saline
- PI3K, phosphoinositide 3-kinase
- PI3K/AKT pathway
- Pathogenic bacterial infection
- QF, Qingfei Xiaoyan Wan
- Ras/MAPK pathway
- SARS, severe acute respiratory syndrome
- SPA, sinapic acid
- TCM, traditional Chinese medicine
- TTBS, Tween 20/Tris-buffered saline
- UPLC, ultra-performance liquid chromatography
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The antitumor effect of tanshinone IIA on anti-proliferation and decreasing VEGF/VEGFR2 expression on the human non-small cell lung cancer A549 cell line. Acta Pharm Sin B 2015; 5:554-63. [PMID: 26713270 PMCID: PMC4675810 DOI: 10.1016/j.apsb.2015.07.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/01/2015] [Accepted: 07/11/2015] [Indexed: 11/24/2022] Open
Abstract
The effects of tanshinone IIA on the proliferation of the human non-small cell lung cancer cell line A549 and its possible mechanism on the VEGF/VEGFR signal pathway were investigated. The exploration of the interaction between tanshinone IIA and its target proteins provides a feasible platform for studying the anticancer mechanism of active components of herbs. The CCK-8 assay was used to evaluate the proliferative activity of A549 cells treated with tanshinone IIA (2.5-80 μmol/L) for 24, 48 and 72 h, respectively. Flow cytometry was used for the detection of cell apoptosis and cell cycle perturbation. VEGF and VEGFR2 expression were studied by Western blotting. The binding mode of tanshinone IIA within the crystal structure of the VEGFR2 protein was evaluated with molecular docking analysis by use of the CDOCKER algorithm in Discovery Studio 2.1. The CCK-8 results showed that tanshinone IIA can significantly inhibit A549 cell proliferation in a dose- and time-dependent manner. Flow cytometry results showed that the apoptosis rate of tested group was higher than the vehicle control, and tanshinone IIA-treated cells accumulated at the S phase, which was higher than the vehicle control. Furthermore, the expression of VEGF and VEGFR2 was decreased in Western blot. Finally, molecular docking analysis revealed that tanshinone IIA could be stably docked into the kinase domain of VEGFR2 protein with its unique modes to form H-bonds with Cys917 and π-π stacking interactions with Val848. In conclusion, tanshinone IIA may suppress A549 proliferation, induce apoptosis and cell cycle arrest at the S phase. This drug may suppress angiogenesis by targeting the protein kinase domains of VEGF/VEGFR2.
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Key Words
- ADM, adriamycin
- CAM, chorioallantoic membrane
- CCK-8, cell counting kit-8
- DMSO, dimethylsulfoxide
- EPCs, endothelial progenitor cells
- FBS, fetal bovine serum
- FCM, flow cytometry
- HRP, horseradish peroxidase
- IC50, 50% inhibitory concentration
- MD, molecular dynamics
- Molecular docking
- NS, normal saline
- NSCLC, non-small cell lung cancer
- Non-small cell lung cancer
- PI, propidium iodide
- PKB/AKT, protein kinase B
- RMSD, root-mean-square deviation
- Tan IIA, tanshinone IIA
- Tanshinone IIA
- VEGF, vascular endothelial growth factor
- VEGF/VEGFR signal pathway
- mOS, median overall survival
- tRR, tumor response rate
- vdW, van der Waals force
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Palmitoyl-ceramide accumulation with necrotic cell death in A549 cells, followed by a steep increase in sphinganine content. BIOCHIMIE OPEN 2015; 1:11-27. [PMID: 29632826 PMCID: PMC5889477 DOI: 10.1016/j.biopen.2015.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/03/2015] [Indexed: 11/29/2022]
Abstract
Ceramides (Cers) have recently been identified as key signaling molecules that mediate biological functions such as cell growth, differentiation, senescence, apoptosis, and autophagy. However, the functions of Cer accumulation in necrotic cell death remain unknown. The aim of this study was to clarify the relationship between Cer accumulation with inhibition of the conversion pathway of Cer and concomitant necrotic cell death. In order to minimize the effect of apoptosis against necrotic cell death, A549 cells having the inhibiting effect of caspase 9 by survivin were used in this study. Consequently, Cer accumulation in A549 cells would likely be associated with a pathway other than the mitochondrial caspase-dependent pathway of apoptosis. Here, we showed that the dual addition of a glucosyl-Cer synthase inhibitor and a ceramidase inhibitor to A549 cell culture induced palmitoyl-Cer accumulation with Cer synthase 5 expression and necrotic cell death with lysosomal rupture together with leakage of cathepsin B/alkalization after 2–3 h, although it is unknown in this study whether the necrotic cell death was caused by the lysosomal rupture. This Cer accumulation was followed by a steep increase in sphinganine base levels via the activation of serine palmitoyltransferase activity brought about by the increase in palmitoyl-coenzyme A concentration as a substrate after 5–6 h. The increase in palmitoyl-coenzyme A concentration was achieved by activation of the fatty acid synthetic pathway from acetyl coenzyme A. Palmitoylceramide accumulation with necrosis is studied. The accumulation is with ceramide synthase 5 expression. The accumulation is followed by high sphinganine levels.
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Key Words
- ([13C16]C16:0-CoA, palmitoyl-13C16 coenzyme A
- 4-HPR, N-(4-hydroxyphenyl)retinamide
- A549 cells
- APCI, atmospheric pressure chemical ionization
- BSA, bovine serum albumin
- C16:0-Cer, palmitoyl-ceramide
- C16:0-CoA, palmitoyl-coenzyme A
- C2:0-CoA, acetyl-coenzyme A
- CHOP, CAAT/enhancer binding protein homologous protein
- CathB, cathepsin B
- Cer, ceramide
- CerS, ceramide synthase
- D-NMAPPD
- D-NMAPPD, N-[(1R,2R)-2-hydroxy-1-(hydroxy-methyl)-2-(4-nitrophenyl)ethyl]tetradecanamide
- DAPI, 4′,6-diamidino-2-phenylindole
- DL-PDMP
- DL-PDMP, DL-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol
- DMEM, Dulbecco's modified Eagle's medium
- DMSO, dimethylsulfoxide
- DTT, dithiothreitol
- ER, endoplasmic reticulum
- ESI, electrospray ionization
- FATP1, fatty acid transport protein 1
- FBS, fetal bovine serum
- GlcCer, glucosylceramide
- IS, internal standard
- L-[2,3,3-D3]Ser, L-serine-2,3,3-D3
- LC3, microtubule-associated protein 1 light chain 3B
- LDH, lactate dehydrogenase
- LMP, lysosomal membrane permeabilization
- Lys, lysosomes
- MAM, mitochondria-associated membrane
- Myriocin, 2-amino-3,4-dihydroxy-2-(hydroxymethyl)-14-oxo-6-eicosenoic acid
- Necrosis
- Palmitoyl-ceramide
- SDS, sodium dodecyl sulfate
- SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- SIM, selected-ion monitoring
- SM, sphingomyelin
- SPT, serine palmitoyltransferase
- SPTLC, SPT-long chain base subunit
- Ser, Serine
- Sphinganine
- [1,2,3,4-13C4]C16:0 acid, palmitic acid-1,2,3,4-13C4
- [2-13C]C2:0 acid, sodium acetate-2-13C
- [D7]d18:0, D-erythro-sphinganine-D7
- [D7]d18:1, D-erythro-sphingosine-D7
- acridine orange, 3,6-Bis(dimethylamino) acridine hydrochloride
- d18:0, sphinganine
- d18:1, sphingosine
- d18:1-[D31]C16:0-Cer, N-palmitoyl [D31]-D-erythro-sphingosine
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1,4-benzoquinone-induced STAT-3 hypomethylation in AHH-1 cells: Role of oxidative stress. Toxicol Rep 2015; 2:864-869. [PMID: 28962422 PMCID: PMC5598509 DOI: 10.1016/j.toxrep.2015.05.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/13/2015] [Accepted: 05/29/2015] [Indexed: 11/19/2022] Open
Abstract
Benzene, a known occupational and environmental contaminant, is associated with increased risk of leukemia. The objectives of this study were to elucidate the regulatory mechanism of the hypomethylated STAT3 involved in benzene toxicity in vitro. As 1,4-benzoquinone (1,4-BQ) is one of benzene’s major toxic metabolites, AHH-1 cells were treated by 1,4-BQ for 24 h with or without pretreatment of the antioxidant a-LA or the methyltransferase inhibitor, 5-aza-2′ deoxycytidine (5-aza). The cell viability was investigated using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. ROS was determined via 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) flow cytometric assays. The level of oxidative stress marker 8-OHdG was measured by enzyme-linked immunosorbent assay. Methylation-specific PCR was used to detect the methylation status of STAT3. Results indicated the significantly increasing expression of ROS and 8-OHdG which accompanied with STAT3 hypomethylation in 1,4-BQ-treated AHH-1 cells. α-LA suppressed the expression of both ROS and 8-OHdG, simultaneously reversed 1,4-BQ-induced STAT3 hypomethylation. However, although the methylation inhibitor, 5-aza reduced the expression level of ROS and 8-OHdG, but had no obvious inhibiting effect on STAT3 methylation level. Taken together, oxidative stress are involved 1,4-BQ-induced STAT3 methylation expression.
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Key Words
- 1,4-BQ, 1,4-benzoquinone
- 1,4-benzoquinone
- 5-aza, 5-aza-2′ deoxycytidine
- 8-OHdG, 8-hydroxy deoxyguanosine adduct
- DCFH-DA, 2,7-dichlorofluorescein diacetate
- DMSO, dimethylsulfoxide
- DNMT, DNA methyltransferase
- ELISA, enzyme-linked immunosorbent assay
- MSP, methylation-specific PCR
- Methylation
- Oxidative stress
- PBS, phosphate buffered saline
- ROS, reactive oxygen species
- STAT3
- α-LA, alpha lipoic acid
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Quantitative analysis of microtubule orientation in interdigitated leaf pavement cells. PLANT SIGNALING & BEHAVIOR 2015; 10:e1024396. [PMID: 26039484 PMCID: PMC4622981 DOI: 10.1080/15592324.2015.1024396] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Leaf pavement cells are shaped like a jigsaw puzzle in most dicotyledon species. Molecular genetic studies have identified several genes required for pavement cells morphogenesis and proposed that microtubules play crucial roles in the interdigitation of pavement cells. In this study, we performed quantitative analysis of cortical microtubule orientation in leaf pavement cells in Arabidopsis thaliana. We captured confocal images of cortical microtubules in cotyledon leaf epidermis expressing GFP-tubulinβ and quantitatively evaluated the microtubule orientations relative to the pavement cell growth axis using original image processing techniques. Our results showed that microtubules kept parallel orientations to the growth axis during pavement cell growth. In addition, we showed that immersion treatment of seed cotyledons in solutions containing tubulin polymerization and depolymerization inhibitors decreased pavement cell complexity. Treatment with oryzalin and colchicine inhibited the symmetric division of guard mother cells.
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Nitrosopersulfide (SSNO(-)) accounts for sustained NO bioactivity of S-nitrosothiols following reaction with sulfide. Redox Biol 2014; 2:234-44. [PMID: 24494198 PMCID: PMC3909780 DOI: 10.1016/j.redox.2013.12.031] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 12/23/2013] [Accepted: 12/23/2013] [Indexed: 11/16/2022] Open
Abstract
Sulfide salts are known to promote the release of nitric oxide (NO) from S-nitrosothiols and potentiate their vasorelaxant activity, but much of the cross-talk between hydrogen sulfide and NO is believed to occur via functional interactions of cell regulatory elements such as phosphodiesterases. Using RFL-6 cells as an NO reporter system we sought to investigate whether sulfide can also modulate nitrosothiol-mediated soluble guanylyl cyclase (sGC) activation following direct chemical interaction. We find a U-shaped dose response relationship where low sulfide concentrations attenuate sGC stimulation by S-nitrosopenicillamine (SNAP) and cyclic GMP levels are restored at equimolar ratios. Similar results are observed when intracellular sulfide levels are raised by pre-incubation with the sulfide donor, GYY4137. The outcome of direct sulfide/nitrosothiol interactions also critically depends on molar reactant ratios and is accompanied by oxygen consumption. With sulfide in excess, a ‘yellow compound’ accumulates that is indistinguishable from the product of solid-phase transnitrosation of either hydrosulfide or hydrodisulfide and assigned to be nitrosopersulfide (perthionitrite, SSNO−; λmax 412 nm in aqueous buffers, pH 7.4; 448 nm in DMF). Time-resolved chemiluminescence and UV–visible spectroscopy analyses suggest that its generation is preceded by formation of the short-lived NO-donor, thionitrite (SNO−). In contrast to the latter, SSNO− is rather stable at physiological pH and generates both NO and polysulfides on decomposition, resulting in sustained potentiation of SNAP-induced sGC stimulation. Thus, sulfide reacts with nitrosothiols to form multiple bioactive products; SSNO− rather than SNO− may account for some of the longer-lived effects of nitrosothiols and contribute to sulfide and NO signaling. Sulfide modulates the bioactivity of nitrosothiols in a concentration-dependent manner. Nitrosopersulfide anions (SSNO−) accumulate at high sulfide/RSNO ratios. SSNO− releases NO and is surprisingly stable in the presence of reduced thiols. SSNO− is a potent activator of soluble guanylyl cyclase. SSNO− is likely to contribute to NO and hydrogen sulfide/polysulfide signaling.
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Key Words
- CysNO, S-nitrosocysteine
- DMF, dimetylformamide
- DMSO, dimethylsulfoxide
- GSNO, S-nitrosoglutathione
- HSNO
- Hydrogen sulfide
- IPN, isopentyl nitrite
- NO+, nitrosonium
- NO, nitric oxide
- Nitric oxide
- Nitroxyl
- Polysulfides
- RFL-6, rat fibroblastoid-like cell line
- SNAP, S-nitrosopenicillamine
- SNO−, thionitrite
- SSNO−, nitrosopersulfide, perthionitrite, PDE, phopsphodiesterase
- cGMP
- sGC, soluble guanylyl cyclase
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Specificity in the actions of the UBR1 ubiquitin ligase in the degradation of nuclear receptors. FEBS Open Bio 2013; 3:394-7. [PMID: 24251101 PMCID: PMC3821023 DOI: 10.1016/j.fob.2013.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/12/2013] [Accepted: 09/12/2013] [Indexed: 11/23/2022] Open
Abstract
The UBR1 ubiquitin ligase promotes degradation of proteins via the N-end rule and by another mechanism that detects a misfolded conformation. Although UBR1 was shown recently to act on protein kinases whose misfolding was promoted by inhibition of Hsp90, it was unknown whether this ubiquitin ligase targeted other client types of the chaperone. We analyzed the role of UBR1 in the degradation of nuclear receptors that are classical clients of Hsp90. Our results showed that UBR1 deletion results in impaired degradation of the glucocorticoid receptor and the androgen receptor but not the estrogen receptor α. These findings demonstrate specificity in the actions of the UBR1 ubiquitin ligase in the degradation of Hsp90 clients in the presence of small molecule inhibitors that promote client misfolding. UBR1 promotes degradation of misfolded glucocorticoid receptors (GR) upon Hsp90 inhibition. Overexpression of UBR1 promotes degradation of the GR without Hsp90 inhibition. UBR1 also promotes degradation of the androgen receptor (AR) but not the estrogen receptor α (ERα).
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Glucose availability is a decisive factor for Nrf2-mediated gene expression. Redox Biol 2013; 1:359-65. [PMID: 24024172 PMCID: PMC3757705 DOI: 10.1016/j.redox.2013.06.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 01/07/2023] Open
Abstract
Activation of the transcription factor Nrf2 (nuclear factor-erythroid 2-related factor 2) is one of the major cellular defense lines against oxidative and xenobiotic stress, but also influences genes involved in lipid and glucose metabolism. It is unresolved whether the cytoprotective and metabolic responses mediated by Nrf2 are connected or separable events in non-malignant cells. In this study we show that activation of Nrf2, either by the small molecule sulforaphane or knockout of the Nrf2 inhibitor Keap1, leads to increased cellular glucose uptake and increased glucose addiction in fibroblasts. Upon Nrf2 activation glucose is preferentially metabolized through the pentose phosphate pathway with increased production of NADPH. Interference with the supply of glucose or the pentose phosphate pathway and NADPH generation not only hampers Nrf2-mediated detoxification of reactive oxygen species on the enzyme level but also Nrf2-initiated expression of antioxidant defense proteins, such as glutathione reductase and heme-oxygenase1. We conclude that the Nrf2-dependent protection against oxidative stress relies on an intact pentose phosphate pathway and that there is crosstalk between metabolism and detoxification already at the level of gene expression in mammalian cells. Activation of Nrf2 results in increased cellular glucose uptake. Upon activation of Nrf2 glucose is preferentially metabolized through the PPP. The resulting increase in NADPH is not only pivotal for functional detoxification of ROS, but also for Nrf2-dependent gene expression in mammalian cells. These data complement our understanding of the metabolic shade of Nrf2 action.
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Key Words
- 3BP, 3-bromopyruvate
- ATP, adenosine triphosphate
- DCF, dichloroflourescein
- DHEA, dehydroandrostendione
- DMSO, dimethylsulfoxide
- G6PD, glucose 6-phosphate dehydrogenase
- GR, glutathione reductase
- Glucose addiction
- Glut1, glucose transporter 1
- HO-1, heme oxygenase-1
- Keap1, Kelch-like ECH-associated protein1
- MEF, mouse embryonic fibroblasts
- Maf, small masculoaponeurotic fibrosarcoma
- NADP, nicotine adenine dinucleotide phosphate
- NQO1, NAD(P)H:quinone oxidoreductase 1
- Nrf2
- Nrf2, nuclear factor-erythroid 2-related factor 2
- OXPHOS, oxidative phosphorylation
- PBS, phosphate buffered saline
- PPP, pentose phosphate pathway
- ROS detoxification
- ROS, reactive oxygen species
- SFN, sulforaphane
- WT, wild type
- ctrl, control
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Oxidized lipids activate autophagy in a JNK-dependent manner by stimulating the endoplasmic reticulum stress response. Redox Biol 2013; 1:56-64. [PMID: 24024137 PMCID: PMC3757667 DOI: 10.1016/j.redox.2012.10.003] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 10/22/2012] [Indexed: 11/30/2022] Open
Abstract
Excessive production of unsaturated aldehydes from oxidized lipoproteins and membrane lipids is a characteristic feature of cardiovascular disease. Our previous studies show that unsaturated lipid peroxidation-derived aldehydes such as 4-hydroxy-trans-2-nonenal (HNE) promote autophagy in rat aortic smooth muscle cells (RASMC). In this study, we examined the mechanism by which HNE induces autophagy. Exposure of RASMC to HNE led to the modification of several proteins, most of which were identified by mass spectrometry and confocal microscopy to be localized to the endoplasmic reticulum (ER). HNE stimulated the phosphorylation of PKR-like ER kinase and eukaryotic initiation factor 2α and increased heme oxygenase-1 (HO-1) abundance. HNE treatment also increased LC3-II formation and the phosphorylation of JNK and p38. Pharmacological inhibition of JNK, but not p38, prevented HNE-induced HO-1 expression and LC3-II formation. Inhibition of JNK increased cell death in HNE-treated cells. Pretreatment with the chemical chaperone phenylbutryic acid prevented LC3-II formation as well as JNK phosphorylation and HO-1 induction. Taken together, these data suggest that autophagic responses triggered by unsaturated aldehydes could be attributed, in part, to ER stress, which stimulates autophagy by a JNK-dependent mechanism and promotes cell survival during oxidative stress.
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Key Words
- 4-hydroxynonenal
- ATF6, activating transcription factor 6
- Autophagy
- DMEM, Delbucco's Eagle Modified Medium
- DMSO, dimethylsulfoxide
- DNPH, 2,4-dinitrophenylhydrazine
- DTT, dithiothreitol
- ECL, enhanced chemiluminescence
- ER, endoplasmic reticulum
- FBS, fetal bovine serum
- Grp, glucose regulated protein
- HEPES, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- HNE, 4-hydroxy-trans-2-nonenal
- HRP, horseradish peroxidase
- IRE, inositol requiring enzyme
- JNK
- JNK, c-jun N-terminal kinase
- LC3, microtubule-associated protein 1 light chain 3
- NP-40, noniodet P40
- Oxidative stress
- PDI, protein disulfide isomerase
- PERK, PKR-like ER kinase
- PVDF, polyvinylidene fluoride
- RASMC, rat aortic smooth muscle cells
- SDS, sodium dodecyl sulfate
- Smooth muscle cells
- UPR, unfolded protein response
- Unfolded protein response
- eIF2α, elongation initiation factor 2 α
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Anthelmintic PF1022A: stepwise solid-phase synthesis of a cyclodepsipeptide containing N-methyl amino acids. Tetrahedron 2012; 68:2068-2073. [PMID: 32287426 PMCID: PMC7111844 DOI: 10.1016/j.tet.2011.12.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/04/2011] [Accepted: 12/10/2011] [Indexed: 11/18/2022]
Abstract
Cyclodepsipeptides of the enniation-, PF1022-, and verticilide-family represent a diverse class of highly interesting natural products with respect to their manifold biological activities. However, until now no stepwise solid-phase synthesis has been accomplished due to the difficult combination of N-methyl amino acids and hydroxycarboxylic acids. We report here the first stepwise solid-phase synthesis of the anthelmintic cyclooctadepsipeptide PF1022A based on an Fmoc/THP-ether protecting group strategy on Wang-resin. The standard conditions of our synthesis allow an unproblematic adaption to an automated peptide synthesizer.
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Key Words
- ACN, acetonitrile
- BOPCl, N,N′-bis(2-oxo-3-oxazolidinyl)phosphinic chloride
- Boc, tert-butyloxycarbonyl
- DCM, dichloromethane
- DEAD, diethylazodicarboxylate
- DHP, 3,4-dihydro-2H-pyrane
- DIC, N,N′-diisopropylcarbodiimide
- DIEA, diisopropylethylamine
- DMAP, 4-dimethylaminopyridine
- DMF, dimethylformamide
- DMSO, dimethylsulfoxide
- EDCI, 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide methiodide
- Fmoc, 9-Fluorenyl-methoxycarbonyl
- HATU, N,N,N′,N′-tetramethyl-O-(7-azabenzo-triazol-1-yl)uroniumhexa-fluorophosphate
- HOAt, 1-hydroxy-7-azabenzotriazole
- HOBt, 1-hydroxy-benzotriazole
- MeOH, methanol
- TEA, triethylamine
- TFA, trifluoro acetic acid
- THF, tetrahydrofuran
- THP, tetrahydropyranyl
- TPP, triphenylphosphane
- p-TsOH, para-toluenesulfonic acid
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Phyllanthin of Standardized Phyllanthus amarus Extract Attenuates Liver Oxidative Stress in Mice and Exerts Cytoprotective Activity on Human Hepatoma Cell Line. J Clin Exp Hepatol 2011; 1:57-67. [PMID: 25755316 PMCID: PMC3940533 DOI: 10.1016/s0973-6883(11)60123-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 08/12/2011] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Phyllanthus amarus, a traditional herbal liver-protecting medicine, is known to contain an active ingredient phyllanthin. Many research studies and clinical trials performed in the past using this plant have given contentious results which clearly accentuates the need for the standardization of the extracts. AIM In this study, P. amarus extract was standardized for phyllanthin content by high performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) analysis. The preventive role of a standardized extract of P. amarus against CC14-induced hepatotoxicity in vivo and in vitro using mice model and human hepatoma HepG2 cell line, respectively, was investigated. METHODS Phyllanthin was used as a marker phytochemical for the standardization of P. amarus extract. The extracts were verified for phyllanthin content by HPTLC and HPLC. Female mice were orally administered with CCl4 either with or without standardized P. amarus extract in three different doses. Similarly, the cytoprotective role of the standardized extract in vitro was studied in HepG2 cell line. RESULTS Oral administration of CCl4 resulted in increased oxidative stress, decreased antioxidative defense, and liver injury. Treatment with P. amarus along with CCl4 significantly mitigated the increase in activities of liver marker enzymes, lipid peroxidation, and bilirubin content. It also increased the antioxidant enzymatic and non-enzymatic defense parameter levels. The results of the in vitro study conducted in HepG2 cells indicated that the hepatotoxin lowered 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (Mil) metabolism and increased the release of transaminases which were corrected with co-incubation with P. amarus. CONCLUSION The study established a significant liver-protecting role of standardized P. amarus extract due to the presence of active ingredient phyllanthin.
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Key Words
- ALT, alanine transaminase
- ANOVA, analysis of variance = AST = aspartate transaminase
- CAM, complementary and alternative medicines
- CAT, catalase
- DMSO, dimethylsulfoxide
- GSH, glutathione
- HBV, hepatitis B virus
- HETP, height equivalent of theoretical plates
- HPLC, high performance liquid chromatography
- HPTLC, high performance thin layer chromatography
- HQC, high quality control
- HepG2
- Hepatitis B virus
- LDH, lactate dehydrogenase
- LPO, lipid peroxidation
- LQC, low quality control
- MDA, malondialdehyde
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
- TAA, total ascorbic acid
- hepatoprotection
- high performance liquid chromatography
- high performance thin layer chromatography
- lipid peroxidation
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