Nonredundant functions of Mycobacterium tuberculosis chaperones promote survival under stress.

Bacterial chaperones ClpB and DnaK, homologs of the respective eukaryotic heat shock proteins Hsp104 and Hsp70, are essential in the reactivation of toxic protein aggregates that occur during translation or periods of stress. In the pathogen Mycobacterium tuberculosis (Mtb), the protective effect of chaperones extends to survival in the presence of host stresses, such as protein-damaging oxidants. However, we lack a full understanding of the interplay of Hsps and other stress response genes in mycobacteria. Here, we employ genome-wide transposon mutagenesis to identify the genes that support clpB function in Mtb. In addition to validating the role of ClpB in Mtb's response to oxidants, we show that HtpG, a homolog of Hsp90, plays a distinct role from ClpB in the proteotoxic stress response. While loss of neither clpB nor htpG is lethal to the cell, loss of both through genetic depletion or small molecule inhibition impairs recovery after exposure to host-like stresses, especially reactive nitrogen species. Moreover, defects in cells lacking clpB can be complemented by overexpression of other chaperones, demonstrating that Mtb's stress response network depends upon finely tuned chaperone expression levels. These results suggest that inhibition of multiple chaperones could work in concert with host immunity to disable Mtb.

Rifamycin action on RNA polymerase in antibiotic-tolerant Mycobacterium tuberculosis results in differentially detectable populations.

Mycobacterium tuberculosis (Mtb) encounters stresses during the pathogenesis and treatment of tuberculosis (TB) that can suppress replication of the bacteria and render them phenotypically tolerant to most available drugs. Where studied, the majority of Mtb in the sputum of most untreated subjects with active TB have been found to be nonreplicating by the criterion that they do not grow as colony-forming units (cfus) when plated on agar. However, these cells are viable because they grow when diluted in liquid media. A method for generating such "differentially detectable" (DD) Mtb in vitro would aid studies of the biology and drug susceptibility of this population, but lack of independent confirmation of reported methods has contributed to skepticism about their existence. Here, we identified confounding artifacts that, when avoided, allowed development of a reliable method of producing cultures of ≥90% DD Mtb in starved cells. We then characterized several drugs according to whether they contribute to the generation of DD Mtb or kill them. Of the agents tested, rifamycins led to DD Mtb generation, an effect lacking in a rifampin-resistant strain with a mutation in rpoB, which encodes the canonical rifampin target, the ß subunit of RNA polymerase. In contrast, thioridazine did not generate DD Mtb from starved cells but killed those generated by rifampin.

N-methylation of a bactericidal compound as a resistance mechanism in Mycobacterium tuberculosis.

The rising incidence of antimicrobial resistance (AMR) makes it imperative to understand the underlying mechanisms. Mycobacterium tuberculosis (Mtb) is the single leading cause of death from a bacterial pathogen and estimated to be the leading cause of death from AMR. A pyrido-benzimidazole, 14, was reported to have potent bactericidal activity against Mtb. Here, we isolated multiple Mtb clones resistant to 14. Each had mutations in the putative DNA-binding and dimerization domains of rv2887, a gene encoding a transcriptional repressor of the MarR family. The mutations in Rv2887 led to markedly increased expression of rv0560c. We characterized Rv0560c as an S-adenosyl-L-methionine-dependent methyltransferase that N-methylates 14, abolishing its mycobactericidal activity. An Mtb strain lacking rv0560c became resistant to 14 by mutating decaprenylphosphoryl-ß-d-ribose 2-oxidase (DprE1), an essential enzyme in arabinogalactan synthesis; 14 proved to be a nanomolar inhibitor of DprE1, and methylation of 14 by Rv0560c abrogated this activity. Thus, 14 joins a growing list of DprE1 inhibitors that are potently mycobactericidal. Bacterial methylation of an antibacterial agent, 14, catalyzed by Rv0560c of Mtb, is a previously unreported mechanism of AMR.

Common Elements in Rare Kidney Diseases: Conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference.

Rare kidney diseases encompass at least 150 different conditions, most of which are inherited. Although individual rare kidney diseases raise specific issues, as a group these rare diseases can have overlapping challenges in diagnosis and treatment. These challenges include small numbers of affected patients, unidentified causes of disease, lack of biomarkers for monitoring disease progression, and need for complex care. To address common clinical and patient issues among rare kidney diseases, the KDIGO Controversies Conference entitled, Common Elements in Rare Kidney Diseases, brought together a panel of multidisciplinary clinical providers and patient advocates to address five central issues for rare kidney diseases. These issues encompassed diagnostic challenges, management of kidney functional decline and progression of chronic kidney disease, challenges in clinical study design, translation of advances in research to clinical care, and provision of practical and integrated patient support. Thus, by a process of consensus, guidance for addressing these challenges was developed and is presented here.

Microbiome perturbation by oral vancomycin reduces plasma concentration of two gut-derived uremic solutes, indoxyl sulfate and p-cresyl sulfate, in end-stage renal disease.

BACKGROUND: Observational studies have suggested a relationship between the plasma concentration of indoxyl sulfate (IS) and p-cresyl sulfate (PCS), small gut-derived 'uremic solutes', and the high incidence of uremic cardiomyopathy in patients with end-stage renal disease (ESRD). IS and PCS are derived from the metabolism of dietary components (tryptophan and tyrosine) by gut bacteria. This pilot study was designed to examine the effects of a poorly absorbable antibiotic (vancomycin) on the plasma concentration of two gut-derived 'uremic solutes', IS and PCS, and on the composition of the gut microbiome. METHODS: Plasma concentrations of IS and PCS were measured by MS-HPLC. The gut microbiome was assessed in stool specimens sequenced for the 16S rRNA gene targeting the V4 region. RESULTS: The pre-dialysis mean plasma concentrations of both IS and PCS were markedly elevated. Following the administration of vancomycin (Day 0), the IS and PCS concentrations decreased at Day 2 or Day 5 and returned to baseline by Day 28. Following vancomycin administration, several changes in the gut microbiome were observed. Most striking was the decrease in diversity, a finding that was evident on Day 7 and was still evident at Day 28. There was little change at the phylum level but at the genus level, broad population changes were noted. Changes in the abundance of several genera appeared to parallel the concentration of IS and PCS. CONCLUSIONS: These findings suggest that alteration of the gut microbiome, by an antibiotic, might provide an important strategy in reducing the levels of IS and PCS in ESRD.

Subjective and objective sleep quality modulate emotion regulatory brain function in anxiety and depression.

BACKGROUND: Disturbances in emotion regulation and sleep are shared across anxiety and mood disorders. Poor sleep has been shown to impair cognitive processes which may undermine cognitive regulatory function. However, it remains unknown if sleep quality impacts regulatory mechanisms in clinical anxiety and depression. METHODS: During fMRI, 78 patients with social anxiety disorder, generalized anxiety disorder, and/or major depressive disorder completed a validated emotion regulation task, which involved reappraisal (i.e., decrease negative affect) as compared to viewing aversive images. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and actigraphy, representing subjective and objective measures of sleep, respectively. Regression analysis was conducted with the PSQI and actigraphy sleep efficiency, duration, and wake-after sleep onset variables. RESULTS: PSQI and actigraphy measures indicated that the majority of patients experienced problematic sleep, however, subjective and objective sleep measures were uncorrelated. Whole-brain voxel-wise regression analysis, controlling for diagnosis, revealed worse self-reported sleep corresponded with less reappraise-related activation in the dorsal anterior cingulate cortex (DACC). The same analysis performed with actigraphy data showed less sleep efficiency positively corresponded with DACC activation. Post-hoc stepwise regression analysis showed these sleep measures predicted DACC activity whereas anxiety and depression symptoms did not. CONCLUSIONS: Individual differences in self-perceived and objective sleep quality differentially modulated the DACC, which is implicated in cognitive reappraisal. Findings suggest neural correlates of emotion regulation tracks different aspects of the sleep experience. Results also indicate sleep disturbance may play a role in the emotion dysregulation observed in anxiety and depressive disorders.

Discovery of Age-Related Protein Folding Stability Differences in the Mouse Brain Proteome.

Described here is the application of thermodynamic stability measurements to study age-related differences in the folding and stability of proteins in a rodent model of aging. Thermodynamic stability profiles were generated for 809 proteins in brain cell lysates from mice, aged 6 (n = 7) and 18 months (n = 9) using the Stability of Proteins from Rates of Oxidation (SPROX) technique. The biological variability of the protein stability measurements was low and within the experimental error of SPROX. A total of 83 protein hits were detected with age-related stability differences in the brain samples. Remarkably, the large majority of the brain protein hits were destabilized in the old mice, and the hits were enriched in proteins that have slow turnover rates (p < 0.07). Furthermore, 70% of the hits have been previously linked to aging or age-related diseases. These results help validate the use of thermodynamic stability measurements to capture relevant age-related proteomic changes and establish a new biophysical link between these proteins and aging.

Rapid, Semiquantitative Assay To Discriminate among Compounds with Activity against Replicating or Nonreplicating Mycobacterium tuberculosis.

The search for drugs that can kill replicating and nonreplicating Mycobacterium tuberculosis faces practical bottlenecks. Measurement of CFU and discrimination of bacteriostatic from bactericidal activity are costly in compounds, supplies, labor, and time. Testing compounds against M. tuberculosis under conditions that prevent the replication of M. tuberculosis often involves a second phase of the test in which conditions are altered to permit the replication of bacteria that survived the first phase. False-positive determinations of activity against nonreplicating M. tuberculosis may arise from carryover of compounds from the nonreplicating stage of the assay that act in the replicating stage. We mitigate these problems by carrying out a 96-well microplate liquid MIC assay and then transferring an aliquot of each well to a second set of plates in which each well contains agar supplemented with activated charcoal. After 7 to 10 days-about 2 weeks sooner than required to count CFU-fluorometry reveals whether M. tuberculosis bacilli in each well have replicated extensively enough to reduce a resazurin dye added for the final hour. This charcoal agar resazurin assay (CARA) distinguishes between bacterial biomasses in any two wells that differ by 2 to 3 log10 CFU. The CARA thus serves as a pretest and semiquantitative surrogate for longer, more laborious, and expensive CFU-based assays, helps distinguish bactericidal from bacteriostatic activity, and identifies compounds that are active under replicating conditions, nonreplicating conditions, or both. Results for 14 antimycobacterial compounds, including tuberculosis (TB) drugs, revealed that PA-824 (pretomanid) and TMC207 (bedaquiline) are largely bacteriostatic.

Nonsteroidal anti-inflammatory drug sensitizes Mycobacterium tuberculosis to endogenous and exogenous antimicrobials.

Existing drugs are slow to eradicate Mycobacterium tuberculosis (Mtb) in patients and have failed to control tuberculosis globally. One reason may be that host conditions impair Mtb's replication, reducing its sensitivity to most antiinfectives. We devised a high-throughput screen for compounds that kill Mtb when its replication has been halted by reactive nitrogen intermediates (RNIs), acid, hypoxia, and a fatty acid carbon source. At concentrations routinely achieved in human blood, oxyphenbutazone (OPB), an inexpensive anti-inflammatory drug, was selectively mycobactericidal to nonreplicating (NR) Mtb. Its cidal activity depended on mild acid and was augmented by RNIs and fatty acid. Acid and RNIs fostered OPB's 4-hydroxylation. The resultant 4-butyl-4-hydroxy-1-(4-hydroxyphenyl)-2-phenylpyrazolidine-3,5-dione (4-OH-OPB) killed both replicating and NR Mtb, including Mtb resistant to standard drugs. 4-OH-OPB depleted flavins and formed covalent adducts with N-acetyl-cysteine and mycothiol. 4-OH-OPB killed Mtb synergistically with oxidants and several antituberculosis drugs. Thus, conditions that block Mtb's replication modify OPB and enhance its cidal action. Modified OPB kills both replicating and NR Mtb and sensitizes both to host-derived and medicinal antimycobacterial agents.

A time to weep and a time to laugh: humour in the nurse-patient relationship in an adult cancer setting.

PURPOSE: The literature highlights the value of humour in health-care settings. Humour impacts on the physiological, psychosocial and cognitive well-being of a person. The diagnosis of cancer is extremely stressful, and treatments are difficult. Patients and nurses may use humour as a coping mechanism to contend with the stresses caused directly or indirectly by cancer. This study investigated the use of humour during interactions between patients and nurses in an adult cancer ward. METHODS: This study used a modified ethnographic methodology that included fieldwork participant observation and informal interviews (n=30 h) and formal interviews (n=10). In total, 9 nurses and 12 patients participated in participant observation. From these, five nurses and five patients were interviewed. Data were analysed using thematic analysis. RESULTS: Findings highlighted the importance of humour in the nurse-patient relationship. Patients consciously use humour during nurse-patient interactions in an attempt to help nurses cope with the stress they encounter in clinical practice. Patients perceive having a sense of humour as a positive nurse attribute. Nurses expressed concerns regarding compromising professionalism when using humour and felt the need for guidance from senior staff. Constant assessment and reflection help ensure humour is used appropriately in the adult health-care setting. CONCLUSION: The benefits of humour are recognised by both adult cancer patients and nurses. A deeper understanding of patient and nurse perceptions of the use of humour can inform strategies for its therapeutic use in the clinical setting.

Landing the job: A guide to successful transition.

Personal development plans (PDPs) guide individuals in personal and professional career enhancement ( Bullock and Jamieson 1998 ). While formats vary, the key component is self-analysis of strengths and weaknesses. This article describes a nurse administrator's successful use of a PDP to progress her career from a mid-level manager position at a small, rural hospital to a senior executive level position at the USA's second largest Veterans Health Administration (VHA) facility. The PDP used VHA's eight core leadership competencies: personal mastery, systems thinking, organisational stewardship, creative thinking, technical skills, interpersonal effectiveness, flexibility, and customer service. These core competencies mirror the VHA's 360° self-assessment tool supported by the National Center for Organization Development ( US Department of Veterans Affairs 2014 ).

Evaluating the impact of a UK recovery college on mental well-being: pre- and post-intervention study.

BACKGROUND: Recovery colleges provide personalised educational mental health support for people who self-refer. The research evidence supporting them is growing, with key components and the positive experiences of attendees reported. However, the quantitative outcome evidence and impact on economic outcomes is limited. AIMS: To evaluate the impact of attending a UK recovery college for students who receive a full educational intervention. METHOD: This is a pre- and post-intervention study, with predominantly quantitative methods. Participants recruited over an 18-month period (01.2020-07.2021) completed self-reported well-being (Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS)) and recovery (Process of Recovery (QPR)) surveys, and provided details and evidence of employment and educational status. Descriptive statistics for baseline data and Shapiro-Wilk, Wilcoxon signed-rank and paired t-tests were used to compare pre- and post-intervention scores, with Hedges' g-statistic as a measure of effect size. Medical records were reviewed and a brief qualitative assessment of changes reported by students was conducted. RESULTS: Of 101 student research participants, 84 completed the intervention. Well-being (mean SWEMWBS scores 17.3 and 21.9; n = 80) and recovery (mean QPR scores 27.2 and 38.8; n = 75) improved significantly (P < 0.001; Hedges' g of 1.08 and 1.03). The number of economically inactive students reduced from 53 (69%) to 19 (24.4%). No research participants were referred for specialist mental health support while students. 'Within-self' and 'practical' changes were described by students following the intervention. CONCLUSIONS: Findings detail the largest self-reported pre-post data-set for students attending a recovery college, and the first data detailing outcomes of remote delivery of a recovery college.

Redirecting raltitrexed from cancer cell thymidylate synthase to Mycobacterium tuberculosis phosphopantetheinyl transferase.

There is a compelling need to find drugs active against Mycobacterium tuberculosis (Mtb). 4'-Phosphopantetheinyl transferase (PptT) is an essential enzyme in Mtb that has attracted interest as a potential drug target. We optimized a PptT assay, used it to screen 422,740 compounds, and identified raltitrexed, an antineoplastic antimetabolite, as the most potent PptT inhibitor yet reported. While trying unsuccessfully to improve raltitrexed's ability to kill Mtb and remove its ability to kill human cells, we learned three lessons that may help others developing antibiotics. First, binding of raltitrexed substantially changed the configuration of the PptT active site, complicating molecular modeling of analogs based on the unliganded crystal structure or the structure of cocrystals with inhibitors of another class. Second, minor changes in the raltitrexed molecule changed its target in Mtb from PptT to dihydrofolate reductase (DHFR). Third, the structure-activity relationship for over 800 raltitrexed analogs only became interpretable when we quantified and characterized the compounds' intrabacterial accumulation and transformation.

Humour in adult cancer care: a concept analysis.

AIMS: To report an analysis of the concept of humour in adult cancer care. BACKGROUND: Humour is a form of communication which is present in the adult cancer setting. Numerous studies show the multi-dimensional value of humour in cancer care. A clear conceptual understanding, however, of what it represents is lacking. DESIGN: Walker and Avant's framework was used to guide this concept analysis. DATA SOURCES: Literature searches included bibliographic databases, internet, and manual searches. REVIEW METHODS: Literature published from 1990 to the present was reviewed. Thematic analysis was carried out to identify critical attributes and antecedents. RESULTS: Based on the analysis, a definition of humour in adult cancer nursing is proposed. Humour is a subjective emotional response, resulting from the recognition and expression of incongruities of a comic, absurd and impulsive situation, remark, character, or action, which enhances feelings of closeness or togetherness when shared in the context of trust between the patient and nurse and may be used as a coping mechanism in a stressful situation such as the adult cancer care setting. CONCLUSION: The analysis provides an understanding of the concept of humour in the adult cancer setting and includes a theoretical illustration of its critical attributes. This concept analysis provides a forum for discussion with reference to the use of humour in adult cancer nursing care. Further exploration is recommended to determine the meaning of humour and its nature across different care settings.

'ZOOMing' in on Consulting with Children and Parents Remotely to Co-Create Health Information Resources.

The COVID-19 pandemic altered the way many people worked. Remote and creative ways were favoured and utilised for consultation activities. In this paper, we draw attention to how we have used creative methods over the teleconferencing platform 'ZOOM' to consult with children and their parents when we were unable to consult with them face-to-face. We document a clear timeline of how we have worked together to co-create an animation and information sheet about receiving outpatient parenteral antimicrobial therapy (OPAT). We identify the opportunities and challenges we faced.

UBQLN2 restrains the domesticated retrotransposon PEG10 to maintain neuronal health in ALS.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron dysfunction and loss. A portion of ALS cases are caused by mutation of the proteasome shuttle factor Ubiquilin 2 (UBQLN2), but the molecular pathway leading from UBQLN2 dysfunction to disease remains unclear. Here, we demonstrate that UBQLN2 regulates the domesticated gag-pol retrotransposon 'paternally expressed gene 10 (PEG10)' in human cells and tissues. In cells, the PEG10 gag-pol protein cleaves itself in a mechanism reminiscent of retrotransposon self-processing to generate a liberated 'nucleocapsid' fragment, which uniquely localizes to the nucleus and changes the expression of genes involved in axon remodeling. In spinal cord tissue from ALS patients, PEG10 gag-pol is elevated compared to healthy controls. These findings implicate the retrotransposon-like activity of PEG10 as a contributing mechanism in ALS through the regulation of gene expression, and restraint of PEG10 as a primary function of UBQLN2.

Mycobacterium tuberculosis PptT Inhibitors Based on Heterocyclic Replacements of Amidinoureas.

4'-Phosphopantetheinyl transferase (PptT) is an essential enzyme for Mycobacterium tuberculosis (Mtb) survival and virulence and therefore an attractive target for a tuberculosis therapeutic. In this work, two modeling-informed approaches toward the isosteric replacement of the amidinourea moiety present in the previously reported PptT inhibitor AU 8918 are reported. Although a designed 3,5-diamino imidazole unexpectedly adopted an undesired tautomeric form and was inactive, replacement of the amidinourea moiety afforded a series of active PptT inhibitors containing 2,6-diaminopyridine scaffolds.

In Vitro and In Vivo Inhibition of the Mycobacterium tuberculosis Phosphopantetheinyl Transferase PptT by Amidinoureas.

A newly validated target for tuberculosis treatment is phosphopantetheinyl transferase, an essential enzyme that plays a critical role in the biosynthesis of cellular lipids and virulence factors in Mycobacterium tuberculosis. The structure-activity relationships of a recently disclosed inhibitor, amidinourea (AU) 8918 (1), were explored, focusing on the biochemical potency, determination of whole-cell on-target activity for active compounds, and profiling of selective active congeners. These studies show that the AU moiety in AU 8918 is largely optimized and that potency enhancements are obtained in analogues containing a para-substituted aromatic ring. Preliminary data reveal that while some analogues, including 1, have demonstrated cardiotoxicity (e.g., changes in cardiomyocyte beat rate, amplitude, and peak width) and inhibit Cav1.2 and Nav1.5 ion channels (although not hERG channels), inhibition of the ion channels is largely diminished for some of the para-substituted analogues, such as 5k (p-benzamide) and 5n (p-phenylsulfonamide).

Identification of ß-Lactams Active against Mycobacterium tuberculosis by a Consortium of Pharmaceutical Companies and Academic Institutions.

Rising antimicrobial resistance challenges our ability to combat bacterial infections. The problem is acute for tuberculosis (TB), the leading cause of death from infection before COVID-19. Here, we developed a framework for multiple pharmaceutical companies to share proprietary information and compounds with multiple laboratories in the academic and government sectors for a broad examination of the ability of ß-lactams to kill Mycobacterium tuberculosis (Mtb). In the TB Drug Accelerator (TBDA), a consortium organized by the Bill & Melinda Gates Foundation, individual pharmaceutical companies collaborate with academic screening laboratories. We developed a higher order consortium within the TBDA in which four pharmaceutical companies (GlaxoSmithKline, Sanofi, MSD, and Lilly) collectively collaborated with screeners at Weill Cornell Medicine, the Infectious Disease Research Institute (IDRI), and the National Institute of Allergy and Infectious Diseases (NIAID), pharmacologists at Rutgers University, and medicinal chemists at the University of North Carolina to screen ∼8900 ß-lactams, predominantly cephalosporins, and characterize active compounds. In a striking contrast to historical expectation, 18% of ß-lactams screened were active against Mtb, many without a ß-lactamase inhibitor. One potent cephaloporin was active in Mtb-infected mice. The steps outlined here can serve as a blueprint for multiparty, intra- and intersector collaboration in the development of anti-infective agents.