Systematic interrogation of CRISPR antimicrobials in Klebsiella pneumoniae reveals nuclease-, guide- and strain-dependent features influencing antimicrobial activity.

CRISPR-Cas systems can be utilized as programmable-spectrum antimicrobials to combat bacterial infections. However, how CRISPR nucleases perform as antimicrobials across target sites and strains remains poorly explored. Here, we address this knowledge gap by systematically interrogating the use of CRISPR antimicrobials using multidrug-resistant and hypervirulent strains of Klebsiella pneumoniae as models. Comparing different Cas nucleases, DNA-targeting nucleases outperformed RNA-targeting nucleases based on the tested targets. Focusing on AsCas12a that exhibited robust targeting across different strains, we found that the elucidated modes of escape varied widely, restraining opportunities to enhance killing. We also encountered individual guide RNAs yielding different extents of clearance across strains, which were linked to an interplay between improper gRNA folding and strain-specific DNA repair and survival. To explore features that could improve targeting across strains, we performed a genome-wide screen in different K. pneumoniae strains that yielded guide design rules and trained an algorithm for predicting guide efficiency. Finally, we showed that Cas12a antimicrobials can be exploited to eliminate K. pneumoniae when encoded in phagemids delivered by T7-like phages. Altogether, our results highlight the importance of evaluating antimicrobial activity of CRISPR antimicrobials across relevant strains and define critical parameters for efficient CRISPR-based targeting.

IgE directly affects eosinophil migration in chronic rhinosinusitis with nasal polyps through CCR3 and predicts the efficacy of omalizumab.

BACKGROUND: Whether IgE affects eosinophil migration in chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unclear. Moreover, our understanding of local IgE, eosinophils, and omalizumab efficacy in CRSwNP remains limited. OBJECTIVE: We investigated whether IgE acts directly on eosinophils and determined its role in omalizumab therapy. METHODS: Eosinophils and their surface receptors were detected by hematoxylin and eosin staining and flow cytometry. IgE and its receptors, eosinophil peroxidase (EPX), eosinophilic cationic protein, and CCR3 were detected by immunohistochemistry and immunofluorescence. Functional analyses were performed on blood eosinophils and polyp tissues. Logistic regression was performed to screen for risk factors. Receiver operating characteristic curve was generated to evaluate the accuracy. RESULTS: Both FcεRI and CD23 were expressed on eosinophils. The expression of FcεRI and CD23 on eosinophil in nasal polyp tissue was higher than in peripheral blood (both P < .001). IgE and EPX colocalized in CRSwNP. IgE directly promoted eosinophil migration by upregulating CCR3 in CRSwNP but not in healthy controls. Omalizumab and lumiliximab were found to be effective in restraining this migration, indicating CD23 was involved in IgE-induced eosinophil migration. Both IgE+ and EPX+ cells were significantly reduced after omalizumab treatment in those who experienced response (IgE+ cells, P = .001; EPX+ cells, P = .016) but not in those with no response (IgE+ cells, P = .060; EPX+ cells, P = .151). Baseline IgE+ cell levels were higher in those with response compared to those without response (P = .024). The baseline local IgE+ cell count predicted omalizumab efficacy with an accuracy of 0.811. CONCLUSIONS: IgE directly promotes eosinophil migration, and baseline local IgE+ cell counts are predictive of omalizumab efficacy in CRSwNP.

Integration of clinical and blood parameters in risk prognostication for patients receiving immunochemotherapy for extensive stage small cell lung cancer: real-world data from two centers.

BACKGROUND: Immune checkpoint inhibitors (ICIs) had modest advances in the treatment of extensive-stage small cell lung cancer (ES-SCLC) in clinical trials, but there is a lack of biomarkers for prognosis in clinical practice. METHODS: We retrospectively collected data from ES-SCLC patients who received ICIs combined chemotherapy from two centers in China, integrated clinical and blood parameters, and constructed risk prognostication for immunochemotherapy. The population was divided into high- and low-risk groups, and the performance of the model was assessed separately in the training and validation cohorts. RESULTS: Two hundred and twenty and 43 patients were included in the training and validation groups, respectively. The important predictors were screened including body mass index, liver metastases, coefficient variation of red blood cell distribution width, lactate dehydrogenase, albumin, and C-reactive protein. Predicting 1-year overall survival (OS), the AUC values under ROC for the model under training, internal validation, and external validation were 0.760, 0.732, and 0.722, respectively, and the calibration curve and clinical decision curve performed well. Applied the model to divide patients into low-risk and high-risk groups, and the median OS was 23.7 months and 9.1 months, and the median progression-free survival was 8.2 months and 4.8 months, respectively; furthermore, this ability to discriminate survival was also observed in the validation cohort. CONCLUSIONS: We constructed a novel prognostic model for ES-SCLC to predict survival employing baseline tumor burden, nutritional and inflammatory parameters, it is easily measured to screen high-risk patient populations.

Comparative investigation of exosome extraction from rat bone marrow mesenchymal stem cells using three different methodologies.

Exosomes have been identified as crucial mediators in numerous physiological and pathological processes, emerging as a focal point of scientific inquiry. This study aims to compare three methods for isolating exosomes from rat bone marrow mesenchymal stem cells: ultracentrifugation (UC), ultrafast separation system (EXODUS), and commercial precipitation kit (EXO-kit). First, the investigation compared exosomal morphology, particle size distribution, and expression of marker proteins. Subsequently, the RNA content, protein concentration, and purity of exosomes were evaluated. Finally, the impact of these exosomes on cellular metabolic viability and migration capacity was assessed. Results indicated that exosomes exhibited spherical or elliptical membrane structures, and most of the exosomes extracted by the three methods were in the range of 30to 200 nm. UC-extracted exosomes demonstrated the least impurities and clearest background, followed by EXODUS-extracted exosomes, and lastly EXO-kit-extracted exosomes. The EXO-kit-extracted exosomes yielded the highest RNA and protein content, whereas those isolated through UC exhibited superior purity. Furthermore, exosomes extracted from EXODUS and EXO-kit methods effectively enhanced the metabolic viability and migratory ability of osteoblast precursor cells compared to UC-extracted exosomes. In conclusion, each of the three methodologies presents advantages and limitations. Therefore, the selection of an appropriate exosome extraction technique should be based on specific experimental objectives and requirements.

Abnormal circulating steroids refine risk of progression to heart failure in ischemic heart disease.

BACKGROUND: Patients with ischemic heart disease (IHD) experience a high incidence of progression to heart failure (HF) despite current therapies. We speculated that steroid hormone metabolic disorders distinct adverse phenotypes and contribute to HF. METHODS: We measured 18 steroids using liquid chromatography with tandem mass spectrometry in 2023 patients from the Registry Study of Biomarkers in Ischemic Heart Disease (BIOMS-IHD), including 1091 patients with IHD in a retrospective discovery set and 932 patients with IHD in a multicentre validation set. Our outcomes included incident HF after a median follow-up of 4 years. RESULTS: We demonstrated steroid-based signatures of inflammation, coronary microvascular dysfunction and left ventricular hypertrophy that were associated with subsequent HF events in patients with IHD. In both cohorts, patients with a high steroid-heart failure score (SHFS) (>1) exhibited a greater risk of incident HF than patients with a low SHFS (≤1). The SHFS further improved the prognostic accuracy beyond clinical variables (net reclassification improvement of 0.628 in the discovery set and 0.299 in the validation set) and demonstrated the maximal effect of steroid signatures in patients with IHD who had lower B-type natriuretic peptide levels (pinteraction = 0.038). CONCLUSIONS: A steroid-based strategy can simply and effectively identify individuals at higher HF risk who may derive benefit from more intensive follow-ups.

Macrophage targeted graphene oxide nanosystem synergize antibiotic killing and host immune defense for Tuberculosis Therapy.

Tuberculosis (TB), a deadly disease caused by Mycobacterium tuberculosis (Mtb) infection, remains one of the top killers among infectious diseases worldwide. How to increase targeting effects of current anti-TB chemotherapeutics and enhance anti-TB immunological responses remains a big challenge in TB and drug-resistant TB treatment. Here, mannose functionalized and polyetherimide protected graphene oxide system (GO-PEI-MAN) was designed for macrophage-targeted antibiotic (rifampicin) and autophagy inducer (carbamazepine) delivery to achieve more effective Mtb killings by combining targeted drug killing and host immunological clearance. GO-PEI-MAN system demonstrated selective uptake by in vitro macrophages and ex vivo macrophages from macaques. The endocytosed GO-PEI-MAN system would be transported into lysosomes, where the drug loaded Rif@Car@GO-PEI-MAN system would undergo accelerated drug release in acidic lysosomal conditions. Rif@Car@GO-PEI-MAN could significantly promote autophagy and apoptosis in Mtb infected macrophages, as well as induce anti-bacterial M1 polarization of Mtb infected macrophages to increase anti-bacterial IFN-γ and nitric oxide production. Collectively, Rif@Car@GO-PEI-MAN demonstrated effectively enhanced intracellular Mtb killing effects than rifampicin, carbamazepine or GO-PEI-MAN alone in Mtb infected macrophages, and could significantly reduce mycobacterial burdens in the lung of infected mice with alleviated pathology and inflammation without systemic toxicity. This macrophage targeted nanosystem synergizing increased drug killing efficiency and enhanced host immunological defense may be served as more effective therapeutics against TB and drug-resistant TB.

Rhodium(III)-Catalyzed C-H Cascade Annulation of Arylhydrazines with 2-Diazo-1,3-indandiones for the Synthesis of Tetracyclic Indeno[1,2-b]indoles.

An efficient approach for the preparation of tetracyclic indeno[1,2-b]indoles via Rh(III)-catalyzed C-H cascade annulation between arylhydrazines and diazo indan-1,3-diones has been established. In addition, a series of indeno[1,2-b]indoles were obtained in up to 96% yield with a wide range of substrates and high functional group tolerance. Finally, the diverse transformations of the desired products demonstrate the synthetic utility and utilization of this protocol.

Relationship between intrinsic capacity and health-related quality of life among community-dwelling older adults: the moderating role of social support.

PURPOSE: To examine how social support might moderate the relationship between intrinsic capacity and health-related quality of life (HRQoL) based on the buffering model of social support. METHODS: This was a cross-sectional study with a sample of 1181 Chinese community-dwelling older adults aged ≥ 60 years in 2016. Social support was assessed using the Social Support Rating Scale. Intrinsic capacity was assessed using the revised integrated care for older people screening tool. HRQoL was measured by the 12-item Short Form Health Survey. Hierarchical linear regression analysis was implemented to test the moderating effect of social support. RESULTS: Support utilization attenuated the relationship between lower intrinsic capacity and poor physical HRQoL while subjective support attenuated the relationship between lower intrinsic capacity and poor mental HRQoL. However, objective support had no significant moderating effect on the relationship between intrinsic capacity and specific domains of HRQoL. CONCLUSION: The moderating effects of social support on the association between intrinsic capacity and HRQoL vary by support types. Effective interventions should target the perception and utilization of available support among older adults with lower intrinsic capacity to maintain their physical and mental HRQoL.

Effectiveness of interventions for informal caregivers of community-dwelling frail older adults: A systematic review and meta-analysis.

AIM: Systematic reviews on interventions for informal caregivers of community-dwelling frail older adults were published over a decade ago and they mistook frailty for other severe age-related conditions like disability and dementia. Therefore, this study aimed to systematically synthesize these interventions supporting these caregivers identified by an acknowledged frailty assessment instrument and to examine their effectiveness on caregiver-related outcomes. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Fourteen electronic databases, grey literature and reference lists were systematically searched for randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) from inception to November 3, 2023. METHODS: Methodology quality and risk of bias were assessed. Data were meta-analysed using the Comprehensive Meta-Analysis, version 3.0. Studies and outcomes unsuitable for meta-analysis were summarized by narrative syntheses. RESULTS: Four studies consisting of three RCTs and one NRCT were included involving 350 participants. Interventions for caregivers of frail older adults included multicomponent interventions (n = 3) and education intervention (n = 1). Interventions had a moderate effect on reducing depression and showed nonsignificant effects on caregiver burden, caregiving time or quality of life (QoL). The PEDro scores for RCTs ranged from 6 to 8, indicating good methodologic quality, but were all judged as high risk of bias. The NRCT reported all methodologic aspects and was at low risk of bias. CONCLUSIONS: Few studies focus on interventions targeting caregivers of frail older adults, and their effectiveness may vary by outcomes. This review suggested the potential benefits of these interventions in reducing caregivers' depression. IMPACT: The differential effectiveness by outcomes and high risk of bias of studies implicate that more rigorous studies are warranted.

Exploring Novel Antidepressants Targeting G Protein-Coupled Receptors and Key Membrane Receptors Based on Molecular Structures.

Major Depressive Disorder (MDD) is a complex mental disorder that involves alterations in signal transmission across multiple scales and structural abnormalities. The development of effective antidepressants (ADs) has been hindered by the dominance of monoamine hypothesis, resulting in slow progress. Traditional ADs have undesirable traits like delayed onset of action, limited efficacy, and severe side effects. Recently, two categories of fast-acting antidepressant compounds have surfaced, dissociative anesthetics S-ketamine and its metabolites, as well as psychedelics such as lysergic acid diethylamide (LSD). This has led to structural research and drug development of the receptors that they target. This review provides breakthroughs and achievements in the structure of depression-related receptors and novel ADs based on these. Cryo-electron microscopy (cryo-EM) has enabled researchers to identify the structures of membrane receptors, including the N-methyl-D-aspartate receptor (NMDAR) and the 5-hydroxytryptamine 2A (5-HT2A) receptor. These high-resolution structures can be used for the development of novel ADs using virtual drug screening (VDS). Moreover, the unique antidepressant effects of 5-HT1A receptors in various brain regions, and the pivotal roles of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and tyrosine kinase receptor 2 (TrkB) in regulating synaptic plasticity, emphasize their potential as therapeutic targets. Using structural information, a series of highly selective ADs were designed based on the different role of receptors in MDD. These molecules have the favorable characteristics of rapid onset and low adverse drug reactions. This review offers researchers guidance and a methodological framework for the structure-based design of ADs.