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Antioxidants & Redox Signaling Nov 2023Persulfides/polysulfides are sulfur-catenated molecular species (, R-S-R', > 2; R-S-H, > 1, with R = cysteine, glutathione, and proteins), such as... (Review)
Review
Persulfides/polysulfides are sulfur-catenated molecular species (, R-S-R', > 2; R-S-H, > 1, with R = cysteine, glutathione, and proteins), such as cysteine persulfide (CysSSH). These species are abundantly formed as endogenous metabolites in mammalian and human cells and tissues. However, the persulfide synthesis mechanism has yet to be thoroughly discussed. We used β-(4-hydroxyphenyl)ethyl iodoacetamide and mass spectrometry to develop sulfur metabolomics, a highly precise, quantitative analytical method for sulfur metabolites. With this method, we detected appreciable amounts of different persulfide species in biological specimens from various organisms, from the domains Bacteria, Archaea, and Eukarya. By using our rigorously quantitative approach, we identified cysteinyl-tRNA synthetase (CARS) as a novel persulfide synthase, and we found that the CysSSH synthase activity of CARS is highly conserved from the domains Bacteria to Eukarya. Because persulfide synthesis is found not only with CARS but also with other sulfotransferase enzymes in many organisms, persulfides/polysulfides are expected to contribute as fundamental elements to substantially diverse biological phenomena. In fact, persulfide generation in higher organisms-that is, plants and animals-demonstrated various physiological functions that are mediated by redox signaling, such as regulation of energy metabolism, infection, inflammation, and cell death, including ferroptosis. Investigating CARS-dependent persulfide production may clarify various pathways of redox signaling in physiological and pathophysiological conditions and may thereby promote the development of preventive and therapeutic measures for oxidative stress as well as different inflammatory, metabolic, and neurodegenerative diseases. 39, 983-999.
Topics: Animals; Humans; Sulfides; Oxidation-Reduction; Cysteine; Sulfur; Mammals
PubMed: 37565274
DOI: 10.1089/ars.2023.0405 -
Nature Sep 2020The transient receptor potential ion channel TRPA1 is expressed by primary afferent nerve fibres, in which it functions as a low-threshold sensor for structurally...
The transient receptor potential ion channel TRPA1 is expressed by primary afferent nerve fibres, in which it functions as a low-threshold sensor for structurally diverse electrophilic irritants, including small volatile environmental toxicants and endogenous algogenic lipids. TRPA1 is also a 'receptor-operated' channel whose activation downstream of metabotropic receptors elicits inflammatory pain or itch, making it an attractive target for novel analgesic therapies. However, the mechanisms by which TRPA1 recognizes and responds to electrophiles or cytoplasmic second messengers remain unknown. Here we use strutural studies and electrophysiology to show that electrophiles act through a two-step process in which modification of a highly reactive cysteine residue (C621) promotes reorientation of a cytoplasmic loop to enhance nucleophilicity and modification of a nearby cysteine (C665), thereby stabilizing the loop in an activating configuration. These actions modulate two restrictions controlling ion permeation, including widening of the selectivity filter to enhance calcium permeability and opening of a canonical gate at the cytoplasmic end of the pore. We propose a model to explain functional coupling between electrophile action and these control points. We also characterize a calcium-binding pocket that is highly conserved across TRP channel subtypes and accounts for all aspects of calcium-dependent TRPA1 regulation, including potentiation, desensitization and activation by metabotropic receptors. These findings provide a structural framework for understanding how a broad-spectrum irritant receptor is controlled by endogenous and exogenous agents that elicit or exacerbate pain and itch.
Topics: Amino Acid Sequence; Calcium; Cysteine; Electric Conductivity; Humans; Iodoacetamide; Ion Channel Gating; Models, Molecular; Mutation; Oximes; TRPA1 Cation Channel
PubMed: 32641835
DOI: 10.1038/s41586-020-2480-9 -
Life Science Alliance Jan 2024We previously reported that activation of p53 by APR-246 reprograms tumor-associated macrophages to overcome immune checkpoint blockade resistance. Here, we demonstrate...
We previously reported that activation of p53 by APR-246 reprograms tumor-associated macrophages to overcome immune checkpoint blockade resistance. Here, we demonstrate that APR-246 and its active moiety, methylene quinuclidinone (MQ) can enhance the immunogenicity of tumor cells directly. MQ treatment of murine B16F10 melanoma cells promoted activation of melanoma-specific CD8 T cells and increased the efficacy of a tumor cell vaccine using MQ-treated cells even when the B16F10 cells lacked p53. We then designed a novel combination of APR-246 with the TLR-4 agonist, monophosphoryl lipid A, and a CD40 agonist to further enhance these immunogenic effects and demonstrated a significant antitumor response. We propose that the immunogenic effect of MQ can be linked to its thiol-reactive alkylating ability as we observed similar immunogenic effects with the broad-spectrum cysteine-reactive compound, iodoacetamide. Our results thus indicate that combination of APR-246 with immunomodulatory agents may elicit effective antitumor immune response irrespective of the tumor's p53 mutation status.
Topics: Mice; Animals; CD8-Positive T-Lymphocytes; Tumor Suppressor Protein p53; Antigens, Neoplasm; Melanoma
PubMed: 37891002
DOI: 10.26508/lsa.202301999 -
Plants (Basel, Switzerland) Feb 2023Species of the family Apiaceae occupy a major market share but are hitherto dependent on open pollinated cultivars. This results in a lack of production uniformity and... (Review)
Review
Species of the family Apiaceae occupy a major market share but are hitherto dependent on open pollinated cultivars. This results in a lack of production uniformity and reduced quality that has fostered hybrid seed production. The difficulty in flower emasculation led breeders to use biotechnology approaches including somatic hybridization. We discuss the use of protoplast technology for the development of somatic hybrids, cybrids and in-vitro breeding of commercial traits such as CMS (cytoplasmic male sterility), GMS (genetic male sterility) and EGMS (environment-sensitive genic male sterility). The molecular mechanism(s) underlying CMS and its candidate genes are also discussed. Cybridization strategies based on enucleation (Gamma rays, X-rays and UV rays) and metabolically arresting protoplasts with chemicals such as iodoacetamide or iodoacetate are reviewed. Differential fluorescence staining of fused protoplast as routinely used can be replaced by new tagging approaches using non-toxic proteins. Here, we focused on the initial plant materials and tissue sources for protoplast isolation, the various digestion enzyme mixtures tested, and on the understanding of cell wall re-generation, all of which intervene in somatic hybrids regeneration. Although there are no alternatives to somatic hybridization, various approaches also discussed are emerging, viz., robotic platforms, artificial intelligence, in recent breeding programs for trait identification and selection.
PubMed: 36903923
DOI: 10.3390/plants12051060 -
Phytomedicine : International Journal... Oct 2022Xiang Sha Liu Junzi decoction (XSLJZD) is a famous traditional Chinese medicinal prescription for the treatment of functional dyspepsia (FD) in spleen deficiency....
Xiangsha Liujunzi Decoction improves gastrointestinal motility in functional dyspepsia with spleen deficiency syndrome by restoring mitochondrial quality control homeostasis.
BACKGROUND
Xiang Sha Liu Junzi decoction (XSLJZD) is a famous traditional Chinese medicinal prescription for the treatment of functional dyspepsia (FD) in spleen deficiency. However, its therapeutic mechanism has not been fully clarified.
PURPOSE
The present study aimed to determine the role of mitochondrial quality control (MQC)-mediated gastrointestinal motility disorder in FD treated with XSLJZD by using spleen-deficient FD rats and gastrointestinal smooth muscle cells (GSMCs).
METHODS
In vivo, an FD with spleen deficiency syndrome model was established by gastric perfusion with iodoacetamide solution combined with the modified multiple platform method (MMPM), followed by intragastric gavage with XSLJZD for 4 weeks. Improvement of pathological symptoms was evaluated based on food intake, water intake, grip strength, gastric histopathological changes, gastric emptying rate, small intestinal propulsion rate, and average amplitude and frequency of smooth muscle strips. The mitochondrial ultrastructure was observed by transmission electron microscopy. The colocalization of LC3 and Parkin with mitochondria was detected by immunofluorescence. The expression and localization of Drp1 proteins were detected by immunohistochemistry. In vitro, GSMCs were treated with different concentrations of XSLJZD-CS for 24 h, followed by treatment with 20 μM carbon cyanide 3-chlorophenylhydrazone (CCCP) for 4 h. Cell viability, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (mtROS), cellular ATP generation and mitochondrial Keima (mtKeima) expression were examined. Both in vivo and in vitro, gene expression was assessed by Western blotting. All experiments were performed in duplicate.
RESULTS
Disorders of the mitochondrial quality control system existed in gastric smooth muscle in FD spleen deficiency syndrome. XSLJZD administration promoted the contraction of gastric smooth muscle and restored mitochondrial function by downregulating the colocalization of LC3 or Parkin with mitochondria, reducing the ratio of LC3II/LC3I, decreasing the expression of PINK1, Parkin and Drp1 and increasing the expression of p62 to restore mitochondrial morphology and function. In vitro studies showed that the improvement in mitochondrial function by XSLJZD was related to PINK1-parkin-mediated mitochondrial quality control.
CONCLUSION
We demonstrated that XSLJZD can improve gastrointestinal motility disorder in functional dyspepsia with spleen deficiency syndrome, which was related to reconstruction of the mitochondrial quality control system by restraining PINK1/Parkin-mediated mitophagy and division. This study illustrates a novel clinical significance of herbal medicine in the treatment of FD and clarifies the important role of MQC in treating gastrointestinal motility disorder.
Topics: Animals; Drugs, Chinese Herbal; Dyspepsia; Gastrointestinal Diseases; Gastrointestinal Motility; Homeostasis; Mitochondria; Protein Kinases; Rats; Spleen; Ubiquitin-Protein Ligases
PubMed: 35963194
DOI: 10.1016/j.phymed.2022.154374 -
PloS One 2020Protein sulfhydryl residues participate in key structural and biochemical functions. Alterations in sulfhydryl status, regulated by either reversible redox reactions or...
Protein sulfhydryl residues participate in key structural and biochemical functions. Alterations in sulfhydryl status, regulated by either reversible redox reactions or by permanent covalent capping, may be challenging to identify. To advance the detection of protein sulfhydryl groups, we describe the production of new Rabbit monoclonal antibodies that react with carbamidomethyl-cysteine (CAM-cys), a product of iodoacetamide (IAM) labeling of protein sulfhydryl residues. These antibodies bind to proteins labeled with IAM (but not N-ethylmaleimide (NEM) or acrylamide) and identify multiple protein bands when applied to Western blots of cell lysates treated with IAM. The monoclonal antibodies label a subset of CAM-cys modified peptide sequences and purified proteins (human von Willebrand Factor (gene:vWF), Jagged 1 (gene:JAG1), Laminin subunit alpha 2 (gene:LAMA2), Thrombospondin-2 (gene:TSP2), and Collagen IV (gene:COL4)) but do not recognize specific proteins such as Bovine serum albumin (gene:BSA) and human Thrombospondin-1 (gene:TSP1), Biglycan (gene:BGN) and Decorin (gene:DCN). Scanning mutants of the peptide sequence used to generate the CAM-cys antibodies elucidated residues required for context dependent reactivity. In addition to recognition of in vitro labeled proteins, the antibodies were used to identify selected sulfhydryl-containing proteins from living cells that were pulse labeled with IAM. Further development of novel CAM-cys monoclonal antibodies in conjunction with other biochemical tools may complement current methods for sulfhydryl detection within specific proteins. Moreover, CAM-cys reactive reagents may be useful when there is a need to label subpopulations of proteins.
Topics: Alkylation; Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antibody Specificity; Antigens; Base Sequence; Blotting, Western; Cattle; Disulfides; Enzyme-Linked Immunosorbent Assay; Ethylmaleimide; Green Fluorescent Proteins; HEK293 Cells; Humans; Iodoacetamide; Peptide Fragments; Proteins; Rabbits; Sequence Alignment; Sequence Homology, Amino Acid; Staining and Labeling; Sulfhydryl Compounds
PubMed: 33232360
DOI: 10.1371/journal.pone.0242376 -
Scientific Reports Feb 2021Celeriac F hybrid seed production is currently complicated due to the instability of cytoplasmic male sterile lines. To develop alternative alloplasmic CMS lines, an...
Celeriac F hybrid seed production is currently complicated due to the instability of cytoplasmic male sterile lines. To develop alternative alloplasmic CMS lines, an asymmetric protoplast fusion and hybrid screening methodology was established. Celeriac suspension cells protoplasts were used as the acceptor and carrot, coriander and white celery mesophyll protoplasts as the donor for protoplast fusion experiments. Acceptor cytoplasmic inheritance was inhibited by iodoacetamide treatment and donor nuclear genome inheritance was prevented by UV exposure. Protoplasts were selectively stained and fused using electroporation and polyethylene glycol, and candidate hybrid shoots were obtained. One chloroplast and three mitochondrial markers that could distinguish acceptor and donors organelles were used to characterize over 600 plants obtained after fusion events, without identifying any cybrid. In order to increase the testing efficiency a high number of micro plantlets were pooled and hence the presence of the carrot specific Atp1 marker in one of the pooled samples was detected. We demonstrated that fusion took place between celeriac and a carrot indicating that the creation of viable hybrids is possible although at a very low frequency. These findings open the path for new cytoplasmic hybridization and the isolation of novel CMS lines of celeriac.
PubMed: 33633203
DOI: 10.1038/s41598-021-83970-y -
Materials (Basel, Switzerland) Feb 2021This work presents an efficient and facile strategy to prepare an α-amylase bioreactor. As enzymes are quite large to be immobilized inside metal-organic frameworks...
This work presents an efficient and facile strategy to prepare an α-amylase bioreactor. As enzymes are quite large to be immobilized inside metal-organic frameworks (MOFs), the tertiary and quaternary structures of α-amylase were first disrupted using a combination of urea, dithiothreitol (DTT), and iodoacetamide (IAA). After losing its tertiary structure, the unfolded proteins can now penetrate into the microporous MOFs, affording fragmented α-amylase@MOF bioreactors. Among the different MOFs evaluated, UiO-66 gave the most promising potential due to the size-matching effect of the α-helix of the fragmented α-amylase with the pore size of UiO-66. The prepared bioreactor exhibited high yields of small carbohydrate (maltose) even when reused up to 15 times (>80% conversion).
PubMed: 33670380
DOI: 10.3390/ma14040870 -
Angewandte Chemie (International Ed. in... Jul 2022Protein persulfides (R-S-SH) have emerged as a common post-translational modification. Detection and quantitation of protein persulfides requires trapping with...
Protein persulfides (R-S-SH) have emerged as a common post-translational modification. Detection and quantitation of protein persulfides requires trapping with alkylating agents. Here we show that alkylating agents differ dramatically in their ability to conserve the persulfide's sulfur-sulfur bond for subsequent detection by mass spectrometry. The two alkylating agents most commonly used in cell biology and biochemistry, N-ethylmaleimide and iodoacetamide, are found to be unsuitable for the purpose of conserving persulfides under biologically relevant conditions. The resulting persulfide adducts (R-S-S-Alk) rapidly convert into the corresponding thioethers (R-S-Alk) by donating sulfur to ambient nucleophilic acceptors. In contrast, certain other alkylating agents, in particular monobromobimane and N-t-butyl-iodoacetamide, generate stable alkylated persulfides. We propose that the nature of the alkylating agent determines the ability of the disulfide bond (R-S-S-Alk) to tautomerize into the thiosulfoxide (R-(S=S)-Alk), and/or the ability of nucleophiles to remove the sulfane sulfur atom from the thiosulfoxide.
Topics: Alkylating Agents; Bridged Bicyclo Compounds; Iodoacetamide; Receptor Protein-Tyrosine Kinases; Sulfides; Sulfur
PubMed: 35506673
DOI: 10.1002/anie.202203684 -
Evidence-based Complementary and... 2022Although, acupoint specificity is regarded as the core of scientific issues in electroacupuncture (EA), the difference of EA on treating functional dyspepsia (FD) at...
Although, acupoint specificity is regarded as the core of scientific issues in electroacupuncture (EA), the difference of EA on treating functional dyspepsia (FD) at different acupoints is unclear. Therefore, this study aims to investigate the different therapeutic effects of EA at lower extremity or abdominal acupoints on the mucosal integrity and lower-inflammatory response in FD. The intragastric administration of iodoacetamide (IA) was performed in 48 rats to establish the FD model. These rats were randomly divided into the control group, the model group and the six EA groups receiving stimulation at the lower extremity (ST36, ST37, and ST39) or abdominal acupoints (ST25, CV4, and CV12) separately. The open-field test (OFT) was measured after 8 weeks of IA, and gastric emptying was evaluated after 10 days of the EA treatment. The local inflammation markers of CD45, eosinophil major basic protein (EMBP), and the tight junction proteins ZO1 and Claudin3 were assessed by immunofluorescence in all groups. Western blot analysis showed that the EMBP and Occludin1 levels in the duodenal. EA at lower extremity acupoint ST36 could improve the gastric emptying. EA at lower extremity acupoints reduced the immunoreactivity of EMBP, but the CD45 was reregulated by the ST37 and ST39 acupoints. The lower extremity acupoints also ameliorated FD-tight junction protein in the expression of Claudin3 and ZO1. However, only the ST36 suppressed the expression of EMBP and recovered the expression of Occludin1. Similarly, the effect of EA at abdominal acupoints was not obvious either in facilitating gastric motility or in improving inflammatory and mucosal injury. EA at lower extremity and abdominal acupoints with the same stimulation parameters had different therapeutic effects in gastric emptying, intestinal mucosal integrity, and inflammation response, thus proving the specificity of acupoints.
PubMed: 35154349
DOI: 10.1155/2022/6548623