Pillar[5]arene-segregated ion pairs for enhanced cycloaddition of epoxides with CO2.

A supramolecular approach using a polyviologen-pillar[5]arene complex as segregated ion pairs was shown to be highly efficient for the conversion of CO2 with epoxides into cyclic carbonates without the need for metals or solvents. The enhanced catalytic performance was achieved by cooperative ion pair segregation and CO2 fixation.

Extreme environments and human health: From the immune microenvironments to immune cells.

Exposure to extreme environments causes specific acute and chronic physiological responses in humans. The adaptation and the physiological processes under extreme environments predominantly affect multiple functional systems of the organism, in particular, the immune system. Dysfunction of the immune system affected by several extreme environments (including hyperbaric environment, hypoxia, blast shock, microgravity, hypergravity, radiation exposure, and magnetic environment) has been observed from clinical macroscopic symptoms to intracorporal immune microenvironments. Therefore, simulated extreme conditions are engineered for verifying the main influenced characteristics and factors in the immune microenvironments. This review summarizes the responses of immune microenvironments to these extreme environments during in vivo or in vitro exposure, and the approaches of engineering simulated extreme environments in recent decades. The related microenvironment engineering, signaling pathways, molecular mechanisms, clinical therapy, and prevention strategies are also discussed.

Effect of intensive blood pressure lowering on left ventricular hypertrophy in patients with hypertension: a meta-analysis of randomized trials.

BACKGROUND: Successful antihypertensive management can limit left ventricular hypertrophy (LVH) and improve the clinical prognosis. However, it remains unclear whether intensive blood pressure (BP) lowering has a greater effect on the occurrence and regression of LVH compared to standard BP lowering. METHODS: We searched the electronic databases of PubMed, EMBASE and Web of Science from inception to 2 June 2023. Relevant and eligible studies were included. A random-effects model was used to estimate the pooled odds ratio (OR) and 95% confidence intervals (CI). RESULT: Four RCTs including 20,747 patients met our inclusion criteria. The results demonstrated that intensive BP lowering was associated with a significantly lower rate of LVH (OR 0.85; 95%CI: 0.78-0.93; I2 48.6%) in patients with hypertension compared to standard BP lowering. Subgroup analysis revealed that the effect of intensive BP lowering on LVH was more pronounced in patients with high cardiovascular disease (CVD) risk factors (OR 0.82; 95%CI: 0.72-0.93; I2 57.9%). In addition, intensive BP lowering led to significant regression of LVH (OR 0.68; 95%CI: 0.52-0.88; I2 45.5%). CONCLUSIONS: Our study suggests that intensive BP lowering should be instigated as soon as possible for optimal control of BP and to prevent regression of LVH, especially in patients with high risk of CVD. However, caution is warranted when treating hypertensive patients with LVH to systolic blood pressure (SBP) targets below 130 mm Hg.

We conducted a meta-analysis of four randomised controlled trials involving 20,747 patients with hypertension. The result suggested that intensive BP lowering should be instigated as soon as possible for optimal control of BP and to prevent regression of LVH, especially in patients with high risk of CVD. However, caution is warranted when treating hypertensive patients with LVH to SBP targets below 130 mm Hg.

Cuproptosis-related signature for clinical prognosis and immunotherapy sensitivity in hepatocellular carcinoma.

BACKGROUND: Copper homeostasis imbalance has been implicated in tumor progression, aggressiveness, and treatment response. However, the precise roles of cuproptosis-related genes (CRGs) in hepatocellular carcinoma (HCC) remain poorly understood. METHODS: In this study, we employed a consensus clustering algorithm to identify distinct molecular subtypes. We then performed Kaplan-Meier analysis and univariate Cox regression analysis to identify prognostic differentially expressed genes. The expression of these genes was subsequently validated using qPCR on fresh-frozen tissues obtained from HCC patients. Moreover, leveraging the TCGA-HCC cohort, we constructed a CRGs-related risk prediction model using the LASSO and multivariate Cox regression analysis. RESULTS: By analyzing the data, we successfully established a CRGs risk prognostic model for HCC patients, comprising five differential genes (CAD, SGCB, TXNRD1, KDR, and MTND4P20). Cox regression analysis revealed that the CRGs risk score could serve as an independent prognostic factor for overall survival (hazard ratio [HR] = 1.308, 95% confidence interval [CI] = 1.200 - 1.426, P < 0.001). The area under the curve (AUC) values of the CRGs-score for predicting 1-year, 3-year, and 5-year survival rates were 0.785, 0.724, and 0.723, respectively. Notably, the expression levels of immune checkpoints (including PD-1, PD-L1, and CTLA4) significantly differed between the low- and high-risk score groups. Furthermore, the low-risk score group displayed increased sensitivity to sorafenib, cisplatin, cyclopamine, nilotinib, salubrinal, and gemcitabine, whereas the high-risk score group exhibited heightened sensitivity to lapatinib, erlotinib, and gefitinib. CONCLUSIONS: Our findings highlight the potential of the CRGs risk score as an independent and promising biomarker for clinical prognosis and immunotherapy sensitivity in HCC patients.

Combatting persister cells: The daunting task in post-antibiotics era.

Over the years, much attention has been drawn to antibiotic resistance bacteria, but drug inefficacy caused by a subgroup of special phenotypic variants - persisters - has been largely neglected in both scientific and clinical field. Interestingly, this subgroup of phenotypic variants displayed their power of withstanding sufficient antibiotics exposure in a mechanism different from antibiotic resistance. In this review, we summarized the clinical importance of bacterial persisters, the evolutionary link between resistance, tolerance, and persistence, redundant mechanisms of persister formation as well as methods of studying persister cells. In the light of our recent findings of membrane-less organelle aggresome and its important roles in regulating bacterial dormancy depth, we propose an alternative approach for anti-persister therapy. That is, to force a persister into a deeper dormancy state to become a VBNC (viable but non-culturable) cell that is incapable of regrowth. We hope to provide the latest insights on persister studies and call upon more research interest into this field.

Serum Lipoprotein(a) and High-Density Lipoprotein Cholesterol Associate with Diabetic Nephropathy: Evidence from Machine Learning Perspectives.

Purpose: Diabetic nephropathy (DN) is a common complication of type 2 diabetes mellitus (T2DM) that significantly impacts the quality of life for affected patients. Dyslipidemia is a known risk factor for developing cardiovascular complications in T2DM patients. However, the association between serum lipoprotein(a) (Lp(a)) and high-density lipoprotein cholesterol (HDL-C) with DN requires further investigation. Patients and Methods: For this cross-sectional study, we randomly selected T2DM patients with nephropathy (DN, n = 211) and T2DM patients without nephropathy (T2DM, n = 217) from a cohort of 142,611 patients based on predefined inclusion and exclusion criteria. We collected clinical data from the patients to identify potential risk factors for DN using binary logistic regression and machine learning. After obtaining the feature importance score of clinical indicators by building a random forest classifier, we examined the correlations between Lp(a), HDL-C and the top 10 indicators. Finally, we trained decision tree models with top 10 features using training data and evaluated their performance with independent testing data. Results: Compared to the T2DM group, the DN group had significantly higher serum levels of Lp(a) (p < 0.001) and lower levels of HDL-C (p = 0.028). Lp(a) was identified as a risk factor for DN, while HDL-C was found to be protective. We identified the top 10 indicators that were associated with Lp(a) and/or HDL-C, including urinary albumin (uALB), uALB to creatinine ratio (uACR), cystatin C, creatinine, urinary ɑ1-microglobulin, estimated glomerular filtration rate (eGFR), urinary ß2-microglobulin, urea nitrogen, superoxide dismutase and fibrinogen. The decision tree models trained using the top 10 features and with uALB at a cut-off value of 31.1 mg/L showed an average area under the receiver operating characteristic curve (AUC) of 0.874, with an AUC range of 0.870 to 0.890. Conclusion: Our findings indicate that serum Lp(a) and HDL-C are associated with DN and we have provided a decision tree model with uALB as a predictor for DN.

Outcome of novel oral anticoagulant versus warfarin in frail elderly patients with atrial fibrillation: a systematic review and meta-analysis of retrospective studies.

BACKGROUND: Frail patients with atrial fibrillation (AF) are thought to be at a higher risk for cerebral infarction and death than patients who are not frail, making preventive interventions important. Anticoagulants should be used in frailty patients with AF. However, there are limited data about anticoagulants in frail patients with AF. Therefore, we concucted this meta-analysis to find the best anticoagulation strategy. METHODS: Systematic electronic searches were conducted on 4 July 2022 4 July 2022, in PubMed, Embase (Ovid), and Cochrane Library. Relevant and eligible cohort studies were included. A random-effects model was used to estimate the pooled Hazard ratio (HR) and 95% confidence intervals (CI). Furthermore, we performed a publication bias analysis and subgroup analysis to explore the source of heterogeneity. RESULT: 3 publications (10 cohorts, 188573 participants) met our inclusion criteria. The pooled analysis showed that ischemic strokes (HR: 0.75; 95%CI: 0.71 to 0.79; I2 = 60.2%), systemic embolism (HR: 0.75; 95%CI: 0.64 to 0.87; I = 68.6%), major bleeding(HR: 0.76; 95%CI: 0.64 to 0.89; I2 = 97.4%), intracranial hemorrhage (HR: 0.57; 95%CI: 0.45 to 0.71; I2 = 54.6%) and cardiovascular death(HR: 0.61; 95%CI: 0.51 to 0.70; I2 = 83.2%) were lower in NOACs as compared with warfarin. Regarding gastrointestinal bleeding, meta-analysis showed no significant differences in the risk of gastrointestinal bleeding (HR: 0.97; 95%CI: 0.69 to 1.36; I2 = 95.9%). . CONCLUSION: NOAC was more effective and safety than warfarin in frail patients with AF.

Genetically predicted chronic rhinosinusitis and the risk of stroke: a two-sample Mendelian randomization study.

Objective: The causal association between chronic rhinosinusitis (CRS) and stroke remains uncertain due to the susceptibility of observational studies to confounding and the possibility of reverse causality. This study aims to examine the potential causal relationship between CRS and the risk of stroke, encompassing various subtypes. Methods: In this research, we utilized genome-wide association study (GWAS) data for CRS from FinnGen. We identified significant single-nucleotide polymorphisms (SNPs) associated with CRS and used them as instrumental variables (IVs). GWAS data for any ischemic stroke (AIS), ischemic stroke (IS), large-artery atherosclerotic stroke (LAS), small-vessel strokes (SVS), cardioembolic strokes (CES), intracerebral hemorrhage (ICH), lobar ICH, and non-lobar ICH came from multi-ancestry GWAS datasets. We conducted two-sample Mendelian randomization (MR) analyses using inverse variance weighting (IVW), weighted median, and MR-Egger regression methods to investigate potential causal relationships between CRS and stroke. Both heterogeneity and pleiotropy were evaluated by sensitivity analyses. Result: The IVW analysis revealed no significant associations between CRS and AIS (OR = 0.99, 95% CI [0.93-1.05], p = 0.73), IS (OR = 0.97, 95% CI [0.81-1.17], p = 0.09), SVS (OR = 0.96, 95% CI [0.82-1.12], p = 0.58), LAS (OR = 0.91, 95% CI [0.77-1.08], p = 0.09), CES (OR = 0.97, 95% CI [0.81-1.17], p = 0.79), ICH (OR = 1.28, 95% CI [0.74-2.22], p = 0.28), lobar ICH (OR = 1.22, 95% CI [0.60-2.50], p = 0.28), and non-lobar ICH (OR = 1.25, 95% CI [0.65-2.40], p = 0.79). Sensitivity analysis found no evidence of horizontal pleiotropy. Conclusion: According to genetic evidence, this Mendelian randomization (MR) study does not indicate a causal relationship between CRS and stroke in European populations. However, further studies are necessary to comprehensively evaluate the potential association between CRS and stroke.

The Association of Neutrophil-Lymphocyte Ratio with Venous Thromboembolism: A Systematic Review and Meta-Analysis.

The neutrophil-lymphocyte ratio(NLR) has been used for diagnosing venous thromboembolism (VTE). We aimed to assess the accuracy of NLR to diagnose VTE by meta-analysis. Systematic electronic searches were conducted June 2, 2021 in PubMed, Embase(Ovid), and Cochrane Library. The search did not have any language or time restriction applied. Our search strategy was based on keywords in combination with both medical subject headings (MeSH) terms and text words. The diagnostic odds ratio, summary receiver operating characteristics, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were estimated. 10 articles with 1513 VTE participants and 2593 control participants were included for quantitative synthesis. The pooled values were as follows: sensitivity = 0.68(95% CI 0.45-0.84), specificity = 0.73(95% CI 0.6-0.83), positive likelihood ratio = 2.5(95% CI 1.8-3.4), negative likelihood ratio = 0.44(95% CI 0.26-0.75), diagnostic odds ratio = 6(95% CI 3-11), and SROC = 0.76(95% CI: 0.73-0.8). NLR could be diagnostic factor for the detection of potential VTE, the accuracy thereof in the current meta-analysis exhibited moderate accuracy for diagnosing VTE. Furthermore, further large cohort studies are needed to determine optimal cut-off values of NLR.

Hydrogen-bonded aromatic amide macrocycles: synthesis, properties and functions.

As a classic example of nearly planar cyclic compounds, hydrogen-bonded aromatic amide (H-bonded aramide) macrocycles, consisting of consecutive intramolecular hydrogen bonds and aromatic residues, receive considerable research attention due to their rich host-guest chemistry. This review provides a detailed summary of the synthesis, properties and functions of H-bonded aramide macrocycles and their derivatives. Herein, the constitutional patterns of these macrocycles are divided into two subcategories: interior hydrogen bonding motifs and exterior hydrogen bonding motifs. Based on these two motifs, we summarize the facile synthesis, self-assembly, host-guest interaction complexation of H-bonded aramide macrocycles and the resulting applications such as molecular recognition, artificial ion channels, soft materials, supramolecular catalysis, and artificial molecular machines. The development of H-bonded aramide macrocycles is still in its infancy, although a considerable number of examples have been reported. We hope that this review will provide useful information and unlock new opportunities in this field.

Clinical Diagnostic and Prognostic Potential of NDRG1 and NDRG2 in Hepatocellular Carcinoma Patients.

Background: Primary liver cancer is still the most common lethal malignancy. The N-myc downstream-regulated gene family (NDRG1-4) is a group of multifunctional proteins associated with carcinogenesis. However, systematic evaluation of the diagnostic and prognostic values of NDRG1 or NDRG2 expression in liver cancer is poorly investigated. Method: The gene expression matrix of liver hepatocellular carcinoma (LIHC) was comprehensively analyzed by the "limma" and "Dseq2" R packages. The Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) were used to identify the biological functional differences. A single-sample GSEA (ssGSEA) was conducted to quantify the extent of immune cell infiltration. Finally, the clinical and prognostic information of LIHC patients was systematically investigated using Kaplan-Meier analysis and logistic and Cox regression analysis. Results: Compared with normal tissues, NDRG1 expression was higher, whereas NDRG2 expression was lower in tumor tissues (P <0.001). The area under the receiver operator characteristic curve (AUROC) of NDRG1 and NDRG2 for LIHC was 0.715 and 0.799, respectively. Kaplan-Meier analysis revealed that NDRG1 and NDRG2 were independent clinical prognostic biomarkers for the overall survival (OS, P = 0.001 and 2.9e-06), progression-free interval (PFI, P = 0.028 and 0.005) and disease-specific survival (DSS, P = 0.027 and P <0.001). The C-indexes and calibration plots of the nomogram suggest that NDRG1 and NDRG2 have an effective predictive performance for OS (C-index: 0.676), DSS (C-index: 0.741) and PFI (C-index: 0.630) of liver cancer patients. The mutation rate of NDRG1 in liver cancer reached up to 14%, and DNA methylation levels of NDRG1 and NDRG2 promoters correlated significantly with clinical prognosis. Conclusions: The mRNA expression and DNA methylation of NDRG superfamily members have the potential for LIHC diagnosis and prognosis via integrative analysis from multiple cohorts.

Escherichia coli Uses a Dedicated Importer and Desulfidase To Ferment Cysteine.

CyuA of Escherichia coli is an inducible desulfidase that degrades cysteine to pyruvate, ammonium, and hydrogen sulfide. Workers have conjectured that its role may be to defend bacteria against the toxic effects of cysteine. However, cyuA sits in an operon alongside cyuP, which encodes a cysteine importer that seems ill suited to protecting the cell from environmental cysteine. In this study, transport measurements established that CyuP is a cysteine-specific, high-flux importer. The concerted action of CyuP and CyuA allowed anaerobic E. coli to employ cysteine as either the sole nitrogen or the sole carbon/energy source. CyuA was essential for this function, and although other transporters can slowly bring cysteine into the cell, CyuP-proficient cells outcompeted cyuP mutants. Cells immediately consumed the ammonia and pyruvate that CyuA generated, with little or none escaping from the cell. The expression of the cyuPA operon depended upon both CyuR, a cysteine-activated transcriptional activator, and Crp. This control is consistent with its catabolic function. In fact, the cyuPA operon sits immediately downstream of the thrABCDEFG operon, which allows the analogous fermentation of serine and threonine; this arrangement suggests that this gene cluster may have moved jointly through the anaerobic biota, providing E. coli with the ability to ferment a limited set of amino acids. Interestingly, both the cyu- and thr-encoded pathways depend upon oxygen-sensitive enzymes and cannot contribute to amino acid catabolism in oxic environments. IMPORTANCE Cysteine is a singularly reactive amino acid; in high concentrations, it can disrupt cytoplasmic metabolism. This phenomenon prompted the view that the cyuPA operon of Escherichia coli serves to detoxify cysteine by degrading it. The present study indicates, however, that the natural purpose of that operon is to provide a concise route of cysteine fermentation. CyuP is the first dedicated cysteine importer to be functionally validated among the bacteria, and CyuA constitutes a cysteine desulfidase. Intriguingly, the CyuA iron-sulfur cofactor is inactivated by oxygen so that cysteine is, uniquely, a carbon source that is usable only in anoxic environments. Presumably, this constraint is tolerable because cysteine is scarce in oxic habitats. It also avoids sulfide release, which could interfere with aerobic respiration. Cysteine joins just serine and threonine as amino acids that E. coli is known to ferment, underscoring that this facultative bacterium is oriented toward the fermentation of carbohydrates.

Optical tweezers integrated surface plasmon resonance holographic microscopy for characterizing cell-substrate interactions under noninvasive optical force stimuli.

The rapid development of bio-mechanical research increases the significance of studying cell behaviors near the substrate under the force stimuli in a real-time manner. Here, we present an optical tweezers (OT) integrated surface plasmon resonance holographic microscopy (SPRHM) to realize the dynamical and in-situ characterizations of cell-substrate interactions with noninvasive optical force stimulations. Using the OT integrated SPRHM (OT-SPRHM), we dynamically manipulate the living cells by OT, and simultaneously, the phase-contrast surface plasmon resonance images of the living cells are obtained and the cell-substrate distance is determined via SPRHM. We show that OT-SPRHM has the advanced capabilities of measuring the optical force and its tiny variations applied to the K562 cells near the substrate. Also, we for the first time reveal the manipulation of the MC3T3-E1 cells by OT. Demonstrating its robustness, this technique provides a powerful tool to explore the responses of various biological specimens to the force stimuli along the cell-substrate interface in the bio-sensing area.

Correction: Threading of three rings on two stations: a convergent approach to [4]rotaxane.

Correction for 'Threading of three rings on two stations: a convergent approach to [4]rotaxane' by Yidan Zhou et al., Chem. Commun., 2021, 57, 13506-13509, DOI: 10.1039/D1CC05501A.

Threading of three rings on two stations: a convergent approach to [4]rotaxane.

A novel approach to efficient and selective construction of [4]rotaxane was proposed to demonstrate the superiority of H-bonded azo-macrocycles in forging higher order rotaxanes. The single crystal structure reveals the importance of the interplay of multiple non-covalent bonding interactions, particularly π-stacking interactions, in stabilizing the host-guest complex. This may open an avenue to the synthesis of oligomeric mechanically interlocked molecules containing fewer stations but more rings.

PE_PGRS: Vital proteins in promoting mycobacterial survival and modulating host immunity and metabolism.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tb), is the leading infectious cause of mortality worldwide. One of the key reasons for M. tb pathogenesis is the capability of M. tb to evade immune elimination and survive in macrophage, eventually causing chronic infection. However the pathogenicity mechanism of M. tb is not unclear yet, and thus diagnosis and therapy for TB remains a challenge. The genome of M. tb, encodes a unique protein family known as the PGRS family, with largely unexplored functions. Recently, an increasing number of reports have shown that the PE_PGRS proteins play critical roles in bacterial pathogenesis and immune evasion. The PE_PGRS protein family, characterized by a special N-terminal PE (Pro (P)-Glu (E) motif) domain and a C-terminal PGRS (Polymorphic GC-rich Repetitive Sequences) domain, is restricted mainly to pathogenic mycobacteria. Here we summarize current literature on the PE_PGRS as vital proteins in promoting bacterial survival and modulating host immunity, cell death and metabolism. We also highlight the potential of PE_PGRS as novel targets of anti-mycobacterial interventions for TB control.

Mycobacterial EST12 activates a RACK1-NLRP3-gasdermin D pyroptosis-IL-1ß immune pathway.

Pyroptosis, an inflammatory form of programmed cell death, has been implicated in eliminating pathogenic infections. However, macrophage pyroptosis-related proteins from Mycobacterium tuberculosis (M.tb) have largely gone unexplored. Here, we identified a cell pyroptosis-inducing protein, Rv1579c, named EST12, secreted from the M.tb H37Rv region of difference 3. EST12 binds to the receptor for activated C kinase 1 (RACK1) in macrophages, and the EST12-RACK1 complex recruits the deubiquitinase UCHL5 to promote the K48-linked deubiquitination of NLRP3, subsequently leading to an NLRP3 inflammasome caspase-1/11-pyroptosis gasdermin D-interleukin-1ß immune process. Analysis of the crystal structure of EST12 reveals that the amino acid Y80 acts as a critical binding site for RACK1. An EST12-deficient strain (H37RvΔEST12) displayed higher susceptibility to M.tb infection in vitro and in vivo. These results provide the first proof that RACK1 acts as an endogenous host sensor for pathogens and that EST12-RACK1-induced pyroptosis plays a pivotal role in M.tb-induced immunity.

Correction: Ciclopirox activates PERK-dependent endoplasmic reticulum stress to drive cell death in colorectal cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

During Oxidative Stress the Clp Proteins of Escherichia coli Ensure that Iron Pools Remain Sufficient To Reactivate Oxidized Metalloenzymes.

Hydrogen peroxide (H2O2) is formed in natural environments by both biotic and abiotic processes. It easily enters the cytoplasms of microorganisms, where it can disrupt growth by inactivating iron-dependent enzymes. It also reacts with the intracellular iron pool, generating hydroxyl radicals that can lethally damage DNA. Therefore, virtually all bacteria possess H2O2-responsive transcription factors that control defensive regulons. These typically include catalases and peroxidases that scavenge H2O2 Another common component is the miniferritin Dps, which sequesters loose iron and thereby suppresses hydroxyl-radical formation. In this study, we determined that Escherichia coli also induces the ClpS and ClpA proteins of the ClpSAP protease complex. Mutants that lack this protease, plus its partner, ClpXP protease, cannot grow when H2O2 levels rise. The growth defect was traced to the inactivity of dehydratases in the pathway of branched-chain amino acid synthesis. These enzymes rely on a solvent-exposed [4Fe-4S] cluster that H2O2 degrades. In a typical cell the cluster is continuously repaired, but in the clpSA clpX mutant the repair process is defective. We determined that this disability is due to an excessively small iron pool, apparently due to the oversequestration of iron by Dps. Dps was previously identified as a substrate of both the ClpSAP and ClpXP proteases, and in their absence its levels are unusually high. The implication is that the stress response to H2O2 has evolved to strike a careful balance, diminishing iron pools enough to protect the DNA but keeping them substantial enough that critical iron-dependent enzymes can be repaired.IMPORTANCE Hydrogen peroxide mediates the toxicity of phagocytes, lactic acid bacteria, redox-cycling antibiotics, and photochemistry. The underlying mechanisms all involve its reaction with iron atoms, whether in enzymes or on the surface of DNA. Accordingly, when bacteria perceive toxic H2O2, they activate defensive tactics that are focused on iron metabolism. In this study, we identify a conundrum: DNA is best protected by the removal of iron from the cytoplasm, but this action impairs the ability of the cell to reactivate its iron-dependent enzymes. The actions of the Clp proteins appear to hedge against the oversequestration of iron by the miniferritin Dps. This buffering effect is important, because E. coli seeks not just to survive H2O2 but to grow in its presence.

Ciclopirox activates PERK-dependent endoplasmic reticulum stress to drive cell death in colorectal cancer.

Ciclopirox (CPX) modulates multiple cellular pathways involved in the growth of a variety of tumor cell types. However, the effects of CPX on colorectal cancer (CRC) and the underlying mechanisms for its antitumor activity remain unclear. Herein, we report that CPX exhibited strong antitumorigenic properties in CRC by inducing cell cycle arrest, repressing cell migration, and invasion by affecting N-cadherin, Snail, E-cadherin, MMP-2, and MMP-9 expression, and disruption of cellular bioenergetics contributed to CPX-associated inhibition of cell growth, migration, and invasion. Interestingly, CPX-induced reactive oxygen species (ROS) production and impaired mitochondrial respiration, whereas the capacity of glycolysis was increased. CPX (20 mg/kg, intraperitoneally) substantially inhibited CRC xenograft growth in vivo. Mechanistic studies revealed that the antitumor activity of CPX relies on apoptosis induced by ROS-mediated endoplasmic reticulum (ER) stress in both 5-FU-sensitive and -resistant CRC cells. Our data reveal a novel mechanism for CPX through the disruption of cellular bioenergetics and activating protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent ER stress to drive cell death and overcome drug resistance in CRC, indicating that CPX could potentially be a novel chemotherapeutic for the treatment of CRC.