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Polysulfides have received increased interest in redox biology due to their role as the precursors of H2S and persulfides. However, the compounds that are suitable for biological investigations are limited to cysteine- and glutathione-derived polysulfides. In this work, we report the preparation and evaluation of a novel polysulfide derived from thioglucose, which represents the first carbohydrate-based polysulfide. This compound, thioglucose tetrasulfide (TGS4), showed excellent stability and water solubility. H2S and persulfide production from TGS4, as well as its associated antioxidative property were also demonstrated. Additionally, TGS4 was demonstrated to significantly induce cellular sulfane sulfur level increase, in particular for the formation of hydropersulfides/trisulfides. These results suggest that TGS4 is a useful tool for polysulfide research.

Abstract Supersulphides are inorganic and organic sulphides with sulphur catenation with diverse physiological functions. Their synthesis is mainly mediated by mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulphide synthase (CPERS). Here, we identify protective functions of supersulphides in viral airway infections (influenza and COVID-19), in aged lungs and in chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF). We develop a method for breath supersulphur-omics and demonstrate that levels of exhaled supersulphides increase in people with COVID-19 infection and in a hamster model of SARS-CoV-2 infection. Lung damage and subsequent lethality that result from oxidative stress and inflammation in mouse models of COPD, IPF, and ageing were mitigated by endogenous supersulphides production by CARS2/CPERS or exogenous administration of the supersulphide donor glutathione trisulphide. We revealed a protective role of supersulphides in airways with various viral or chronic insults and demonstrated the potential of targeting supersulphides in lung disease.

A principal concept in developing antibacterial agents with selective toxicity is blocking metabolic pathways that are critical for bacterial growth but that mammalian cells lack. Serine O-acetyltransferase (CysE) is an enzyme in many bacteria that catalyzes the first step in l-cysteine biosynthesis by transferring an acetyl group from acetyl coenzyme A (acetyl-CoA) to l-serine to form O-acetylserine. Because mammalian cells lack this l-cysteine biosynthesis pathway, developing an inhibitor of CysE has been thought to be a way to establish a new class of antibacterial agents. Here, we demonstrated that alkyl gallates such as octyl gallate (OGA) could act as potent CysE inhibitors in vitro and in bacteria. Mass spectrometry analyses indicated that OGA treatment markedly reduced intrabacterial levels of l-cysteine and its metabolites including glutathione and glutathione persulfide in Escherichia coli to a level similar to that found in E. coli lacking the cysE gene. Consistent with the reduction of those antioxidant molecules in bacteria, E. coli became vulnerable to hydrogen peroxide-mediated bacterial killing in the presence of OGA. More important, OGA treatment intensified susceptibilities of metallo-β-lactamase-expressing Gram-negative bacteria (E. coli and Klebsiella pneumoniae) to carbapenem. Structural analyses showed that alkyl gallate bound to the binding site for acetyl-CoA that limits access of acetyl-CoA to the active site. Our data thus suggest that CysE inhibitors may be used to treat infectious diseases caused by drug-resistant Gram-negative bacteria not only via direct antibacterial activity but also by enhancing therapeutic potentials of existing antibiotics.

The excessive inflammatory response of macrophages plays a vital role in the pathogenesis of various diseases. The dynamic metabolic alterations in macrophages, including amino acid metabolism, are known to orchestrate their inflammatory phenotype. To explore a new metabolic pathway that regulates the inflammatory response, we examined metabolome changes in mouse peritoneal macrophages (PMs) in response to lipopolysaccharide (LPS) and found a coordinated increase of cysteine and its related metabolites, suggesting an enhanced demand for cysteine during the inflammatory response. Because Slc7a11, which encodes a cystine transporter xCT, was remarkably upregulated upon the pro-inflammatory challenge and found to serve as a major channel of cysteine supply, we examined the inflammatory behavior of Slc7a11 knockout PMs (xCT-KO PMs) to clarify an impact of the increased cysteine demand on inflammation. The xCT-KO PMs exhibited a prolonged upregulation of pro-inflammatory genes, which was recapitulated by cystine depletion in the culture media of wild-type PMs, suggesting that cysteine facilitates the resolution of inflammation. Detailed analysis of the sulfur metabolome revealed that supersulfides, such as cysteine persulfide, were increased in PMs in response to LPS, which was abolished in xCT-KO PMs. Supplementation of N-acetylcysteine tetrasulfide (NAC-S2), a supersulfide donor, attenuated the pro-inflammatory gene expression in xCT-KO PMs. Thus, activated macrophages increase cystine uptake via xCT and produce supersulfides, creating a negative feedback loop to limit excessive inflammation. Our study highlights the finely tuned regulation of macrophage inflammatory response by sulfur metabolism.

Oxidative stress is responsible for the onset and progression of various kinds of diseases including rhabdomyolysis-induced acute kidney injury (AKI). Antioxidants are, therefore, thought to aid in the recovery of illnesses linked to oxidative stress. Supersulfide species have been shown to have substantial antioxidative activity; however, due to their limited bioavailability, few supersulfide donors have had their actions evaluated in vivo. In this study, human serum albumin (HSA) and N-acetyl-L-cysteine polysulfides (NACSn), which have polysulfides in an oxidized form, were conjugated to create a supersulfide donor. HSA is chosen to be a carrier of NACSn because of its extended blood circulation and high level of biocompatibility. In contrast to a supersulfide donor containing reduced polysulfide in HSA, the NACSn-conjugated HSAs exhibited stronger antioxidant activity than HSA and free NACSn without being uptaken by the cells in vitro. The supersulfide donor reduced the levels of blood urea nitrogen and serum creatinine significantly in a mouse model of rhabdomyolysis-induced AKI. Supersulfide donors significantly reduced the expression of oxidative stress markers in the kidney. These results indicate that the developed supersulfide donor has the therapeutic effect on rhabdomyolysis-induced AKI.

Summary: Infection of mice with Citrobacter rodentium is a useful model for studying the pathogenicity of enteropathogenic and enterohemorrhagic Escherichia coli, pathogens that have a close association with humans. Here, we provide a protocol detailing the approaches for non-canonical inflammasome analysis in a mouse model of C. rodentium infection, including preparation of bacteria, oral administration of bacteria to mice, counting colony-forming units to quantify bacterial colonization, and analysis of expression and activation of inflammasome-related factors.For complete details on the use and execution of this protocol, please refer to Tsutsuki et al. (2022). : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Accumulating evidence suggests that high levels of Fusobacterium nucleatum in colorectal tumor tissues can be associated with poor prognosis in patients with colorectal cancer (CRC); however, data regarding distinct prognostic subgroups in F. nucleatum–positive CRC remain limited. Herein, we demonstrate that high-iron status was associated with a worse prognosis in patients with CRC with F. nucleatum. Patients with CRC presenting elevated serum transferrin saturation exhibited preferential iron deposition in macrophages in the tumor microenvironment. In addition, F. nucleatum induced CCL8 expression in macrophages via the TLR4/NF-κB signaling pathway, which was inhibited by iron deficiency. Mechanistically, iron attenuated the inhibitory phosphorylation of NF-κB p65 by activating serine/threonine phosphatases, augmenting tumor-promoting chemokine production in macrophages. Our observations indicate a key role for iron in modulating the NF-κB signaling pathway and suggest its prognostic potential as a determining factor for interpatient heterogeneity in F. nucleatum–positive CRC.

Summary: Subtilase cytotoxin (SubAB) is an AB5 toxin mainly produced by the locus of enterocyte effacement-negative Shiga-toxigenic Escherichia coli (STEC) strain such as O113:H21, yet the contribution of SubAB to STEC infectious disease is unclear. We found that SubAB reduced activation of the STEC O113:H21 infection-induced non-canonical NLRP3 inflammasome and interleukin (IL)-1β and IL-18 production in murine macrophages. Downstream of lipopolysaccharide signaling, SubAB suppressed caspase-11 expression by inhibiting interferon-β/STAT1 signaling, followed by disrupting formation of the NLRP3/caspase-1 assembly. These inhibitions were regulated by PERK/IRE1α-dependent endoplasmic reticulum (ER) stress signaling initiated by cleavage of the host ER chaperone BiP by SubAB. Our murine model of SubAB-producing Citrobacter rodentium demonstrated that SubAB promoted C. rodentium proliferation and worsened symptoms such as intestinal hyperplasia and diarrhea. These findings highlight the inhibitory effect of SubAB on the NLRP3 inflammasome via ER stress, which may be associated with STEC survival and infectious disease pathogenicity in hosts.

The spike protein of SARS-CoV-2 triggers macrophages and epithelial cells to produce excess levels of pro-inflammatory molecules, which can do more harm than good.

The NLRP3 inflammasome is a multiprotein complex responsible for the maturation of precursor forms of interleukin (IL)-1β and IL-18 into active proinflammatory cytokines. Increasing evidence suggests that modulation of redox homeostasis contributes to the activation of the NLRP3 inflammasome. However, specific mechanistic details remain unclear. We demonstrate here that ATP exposure evoked a sharp decrease in glutathione (GSH) levels in macrophages, which led to NLRP3 inflammasome activation. We detected an increase in GSH levels in culture supernatants that was comparable to the GSH decrease in macrophages, which suggests that exposure to ATP stimulated GSH efflux. Exogenous addition of P2X7 receptor antagonist, GSH, or the oxidized form GSSG attenuated this efflux. Also, exogenous GSH or GSSG strongly inhibited NLRP3 inflammasome activation in vitro and in vivo. These data suggest that GSH efflux controls NLRP3 inflammasome activation, which may lead to development of novel therapeutic strategies for NLRP3 inflammasome-associated disorders.

Advances in drug delivery systems (DDSs) have enabled the specific delivery of drugs to target cells. Subtilase cytotoxin (SubAB) produced by certain enterohemorrhagic Escherichia coli strains induces endoplasmic reticulum (ER) stress and suppresses nitric oxide generation in macrophages. We previously reported that modification of SubAB with poly(D,L-lactide-co-glycolic) acid (PLGA) nanoparticles (SubAB-PLGA NPs) increased intracellular uptake of SubAB and had an anti-inflammatory effect on macrophages. However, specific delivery of SubAB to macrophages could not be achieved because its effects on other cell types were not negligible. Therefore, to suppress non-specific SubAB binding, we used low-binding mutant SubABS35A (S35A) in which the 35th serine of the B subunit was mutated to alanine. In a macrophage cell line, PLGA NPs modified with S35A (S35A-PLGA NPs) induced ER stress and had anti-inflammatory effects similar to WT-PLGA NPs. However, in an epithelial cell line, S35A-PLGA NPs induced lower ER stress than WT-PLGA NPs. These results suggest that S35A is selectively delivered to macrophages rather than epithelial cells by modification with PLGA NPs and exerts anti-inflammatory effects. Our findings provide a useful technique for protein delivery to macrophages and encourage medical applications of DDSs for the treatment of inflammatory diseases.

Blood-brain barrier (BBB) impairment clearly accelerates brain disease progression. As ways to prevent injury-induced barrier dysfunction remain elusive, better understanding of how BBB cells interact and modulate barrier integrity is needed. Our metabolomic profiling study showed that cell-specific adaptation to injury correlates well with metabolic reprogramming at the BBB. In particular we noted that primary astrocytes (AC) contain comparatively high levels of glutathione (GSH)-related metabolites compared to primary endothelial cells (EC). Injury significantly disturbed redox balance in EC but not AC motivating us to assess 1) whether an AC-EC GSH shuttle supports barrier stability and 2) the impact of GSH on EC function. Using an isotopic labeling/tracking approach combined with Time-of-Flight Mass Spectrometry (TOF-MS) we prove that AC constantly shuttle GSH to EC even under resting conditions - a flux accelerated by injury conditions in vitro. In correlation, co-culture studies revealed that blocking AC GSH generation and secretion via siRNA-mediated γ-glutamyl cysteine ligase (GCL) knockdown significantly compromises EC barrier integrity. Using different GSH donors, we further show that exogenous GSH supplementation improves barrier function by maintaining organization of tight junction proteins and preventing injury-induced tight junction phosphorylation. Thus the AC GSH shuttle is key for maintaining EC redox homeostasis and BBB stability suggesting GSH supplementation could improve recovery after brain injury.

Background. Familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). Because of underdiagnosis, acute coronary syndrome (ACS) is often the first clinical manifestation of FH. In Japan, there are few reports on the prevalence and diagnostic ratios of FH and the proportion of ACS among FH patients in clinical settings. Methods. This retrospective, observational study used anonymized data from electronic healthcare databases between April 2001 and March 2015 of patients who had ≥2 LDL-C measurements recorded after April 2009. The index date was defined as the date of the first LDL-C measurement after April 2009. The primary endpoint was the prevalence of definite or suspected FH; secondary endpoints included the proportion of FH patients hospitalized for ACS, the proportion of patients using lipid-lowering drugs (LLDs), and LDL-C levels. Results. Of the 187,781 patients screened, 1547 had definite or suspected FH (0.8%) based on data from the entire period; 832 patients with definite (n=299, 0.16%) or suspected FH (n=533, 0.28%) before the index date were identified in the main analysis cohort. LLDs were used in 214 definite FH patients (71.6%) and 137 suspected FH patients (25.7%). Among definite or suspected FH patients with ACS (n=84) and without ACS (n=748), 32.1% and 30.1% with definite FH and 3.2% and 2.4% with suspected FH had LDL-C levels

SP7/Osterix is a transcription factor involved in osteoblast differentiation. Here, the authors show that Sirtuin 7 activates Osterix posttranslationally by regulating its lysine acylation, and that mice lacking Sirtuin 7 in osteoblasts show reduced bone formation.

Background: To address a clinical impact of atherosclerotic cardiovascular diseases (CVD) on cancer developments, we investigated an issue whether any difference in an incidence of cancers is present between patients with atherosclerotic CVD and those with non-atherosclerotic CVD. Methods: Of a total of 32,095 consecutive patients with acquired CVD enrolled in the Sakakibara Health Integrative Profile cohort study, we segregated patients based on a presence of atherosclerotic or non-atherosclerotic CVD to investigate an incidence of cancers and mortality. We also evaluated an incidence of cancers in patients with a singular presence versus a plural presence of atherosclerotic CVD. Atherosclerotic CVD included coronary artery diseases, aortic diseases and peripheral artery diseases. Non-atherosclerotic CVD were any acquired CVD except atherosclerotic CVD. Results: During a median follow-up of 1020 days (interquartile range, 665–1340 days), an incidence of cancers (5% vs. 2%, p = 0.0001) and overall mortality (6% vs. 3%, p = 0.0001) were more than two-fold higher in 10,592 patients with atherosclerotic CVD than in 21,503 patients with non-atherosclerotic CVD. A presence of atherosclerotic CVD (hazard ratio 1.372 with 95% confidence interval 1.199–1.569) was independently associated with an incidence of cancers. In patients with atherosclerotic CVD, 61 of 640 patients with a plural presence and 470 of 9932 patients with a singular presence developed cancers (9% vs. 5%, p = 0.0001). An incremental risk of death was found according to a presence of atherosclerotic CVD, cancers, and both of them (all p = 0.0001). Conclusions: A presence of atherosclerotic CVD itself may have a potential risk for cancer developments. Trial registration: ClinicalTrials.gov. number, NCT03005834

Cysteine hydropersulfides (CysSSH) are believed to have a cellular redox protective role. Here the authors show that these species can be produced from L-cysteine by cysteinyl-tRNA synthetases and that these enzymes are also involved in mitochondrial biogenesis and bioenergetics regulation.

The physiological importance of reactive sulfur species (RSS) such as cysteine hydropersulfide (CysSSH) has been increasingly recognized in recent years. We have established a reactive sulfur metabolomics analysis by using RSS metabolic profiling, which revealed appreciable amounts of RSS generated endogenously and ubiquitously in both prokaryotic and eukaryotic organisms. The chemical nature of these polysulfides is not fully understood, however, because of their reactive or complicated redox-active properties. In our study here, we determined that tyrosine and a hydroxyphenyl-containing derivative, β-(4-hydroxyphenyl)ethyl iodoacetamide (HPE-IAM), had potent stabilizing effects on diverse polysulfide residues formed in CysSSH-related low-molecular-weight species, e.g., glutathione polysulfides (oxidized glutathione trisulfide and oxidized glutathione tetrasulfide). The protective effect against degradation was likely caused by the inhibitory activity of hydroxyphenyl residues of tyrosine and HPE-IAM against alkaline hydrolysis of polysulfides. This hydrolysis occurred via heterolytic scission triggered by the hydroxyl anion acting on polysulfides that are cleaved into thiolates and sulfenic acids, with the hydrolysis being enhanced by alkylating reagents (e.g. IAM) and dimedone. Moreover, tyrosine prevented electrophilic degradation occurring in alkaline pH. The polysulfide stabilization induced by tyrosine or the hydroxyphenyl moiety of HPE-IAM will greatly improve our understanding of the chemical properties of polysulfides and may benefit the sulfur metabolomics analysis if it can be applied successfully to any kind of biological samples, including clinical specimens. Keywords: Reactive sulfur species, β-(4-Hydroxyphenyl)ethyl iodoacetamide, Tyrosine, Reactive sulfur metabolomics analysis, Reactive sulfur signaling, Redox signaling

Cysteine persulfide (CysSSH) and cysteine polysulfides (CysSSnH, n > 1) are cysteine derivatives that have sulfane sulfur atoms bound to cysteine thiol. Advances in analytical methods that detect and quantify persulfides and polysulfides have shown that CysSSH and related species such as glutathione persulfide occur physiologically and are prevalent in prokaryotes, eukaryotes, and mammals in vivo. The chemical properties and abundance of these compounds suggest a central role for reactive persulfides in cell-regulatory processes. CysSSH and related species have been suggested to act as powerful antioxidants and cellular protectants and may serve as redox signaling intermediates. It was recently shown that cysteinyl-tRNA synthetase (CARS) is a new cysteine persulfide synthase. In addition, we discovered that CARS is involved in protein polysulfidation that is coupled with translation. Mitochondrial activity in biogenesis and bioenergetics is supported and upregulated by CysSSH derived from mitochondrial CARS. In this review article, we discuss the mechanisms of the biosynthesis of CysSSH and related persulfide species, with a particular focus on the roles of CARS. We also review the antioxidative and anti-inflammatory actions of persulfides.

Helicobacter cinaedi is associated with nosocomial infections. The CRISPR-Cas system provides adaptive immunity against foreign genetic elements. We investigated the CRISPR-Cas system in H. cinaedi to assess the potential of the CRISPR-based microevolution of H. cinaedi strains. A genotyping method based on CRISPR spacer organization was carried out using 42 H. cinaedi strains. The results of sequence analysis showed that the H. cinaedi strains used in this study had two CRISPR loci (CRISPR1 and CRISPR2). The lengths of the consensus direct repeat sequences in CRISPR1 and CRISPR2 were both 36 bp-long, and 224 spacers were found in the 42 H. cinaedi strains. Analysis of the organization and sequence similarity of the spacers of the H. cinaedi strains showed that CRISPR arrays could be divided into 7 different genotypes. Each genotype had a different ancestral spacer, and spacer acquisition/deletion events occurred while isolates were spreading. Spacer polymorphisms of conserved arrays across the strains were instrumental for differentiating closely-related strains collected from the same hospital. MLST had little variability, while the CRISPR sequences showed remarkable diversity. Our data revealed the structural features of H. cinaedi CRISPR loci for the first time. CRISPR sequences constitute a valuable basis for genotyping, provide insights into the divergence and relatedness between closely-related strains, and reflect the microevolutionary process of H. cinaedi.

ObjectivesOver the past decade, hospitals and clinics have gradually adopted hospital information systems, including provider order entries and electronic health records. Although these systems have helped to improve patient safety and efficiency of healthcare providers, not all healthcare providers and patients are satisfied with the current situation. Healthcare should be smarter. Thus, there is a need for state-of-the-art medical and healthcare devices that can handle massive amounts of data with the help of sophisticated information processing and discovery technologies.MethodsThis article compares hospital information systems with the information systems of other social infrastructures. It also explores the possibilities of smarter healthcare, including personal health devices and personal health records with interoperability.ResultsThe main traits of the iEHR at Teikyo University Hospital in Tokyo include IT governance, unification, and workflow efficiency.ConclusionsSmarter healthcare can be achieved by leveraging the full capabilities of devices, data, and sophisticated algorithms.

Background: Adenoviral gene transfer has been shown to be effective in cardiac myocytes in vitro and in vivo. A major limitation of myocardial gene therapy is the extracardiac transgene expression. Methods: To minimize extracardiac gene expression, we have constructed a tissue-specific promoter for cardiac gene transfer, namely, the 250-bp fragment of the myosin light chain-2v (MLC-2v) gene, which is known to be expressed in a tissue-specific manner in ventricular myocardium followed by a luciferase (luc) reporter gene (Ad.4 × MLC 250 .Luc). Rat cardiomyocytes, liver and kidney cells were infected with Ad.4 × MLC.Luc or control vectors. For in vivo testing, Ad.4 × MLC 250 .Luc was injected into the myocardium or in the liver of rats. Kinetics of promoter activity were monitored over 8 days using a cooled CCD camera. Results: In vitro: By infecting hepatic versus cardiomyocyte cells, we found that the promoter specificity ratio (luc activity in cardiomyocytes per liver cells) was 20.4 versus 0.9 (Ad.4 × MLC 250 .Luc vs. Ad.CMV). In vivo: Ad.4 × MLC 250 .Luc significantly reduced luc activity in liver (38.4-fold), lung (16.1-fold), and kidney (21.8-fold) versus Ad.CMV ( p = .01); whereas activity in the heart was only 3.8-fold decreased. The gene expression rate of cardiomyocytes versus hepatocytes was 7:1 (Ad.4 × MLC.Luc) versus 1:1.4 (Ad.CMV.Luc). Discussion: This new vector may be useful to validate therapeutic approaches in animal disease models and offers the perspective for selective expression of therapeutic genes in the diseased heart.