Canonical BAF complex activity shapes the enhancer landscape that licenses CD8+ T cell effector and memory fates.

CD8+ T cells provide host protection against pathogens by differentiating into distinct effector and memory cell subsets, but how chromatin is site-specifically remodeled during their differentiation is unclear. Due to its critical role in regulating chromatin and enhancer accessibility through its nucleosome remodeling activities, we investigated the role of the canonical BAF (cBAF) chromatin remodeling complex in antiviral CD8+ T cells during infection. ARID1A, a subunit of cBAF, was recruited early after activation and established de novo open chromatin regions (OCRs) at enhancers. Arid1a deficiency impaired the opening of thousands of activation-induced enhancers, leading to loss of TF binding, dysregulated proliferation and gene expression, and failure to undergo terminal effector differentiation. Although Arid1a was dispensable for circulating memory cell formation, tissue-resident memory (Trm) formation was strongly impaired. Thus, cBAF governs the enhancer landscape of activated CD8+ T cells that orchestrates TF recruitment and activity and the acquisition of specific effector and memory differentiation states.

CTLA-4 blockade induces a microglia-Th1 cell partnership that stimulates microglia phagocytosis and anti-tumor function in glioblastoma.

The limited efficacy of immunotherapies against glioblastoma underscores the urgency of better understanding immunity in the central nervous system. We found that treatment with αCTLA-4, but not αPD-1, prolonged survival in a mouse model of mesenchymal-like glioblastoma. This effect was lost upon the depletion of CD4+ T cells but not CD8+ T cells. αCTLA-4 treatment increased frequencies of intratumoral IFNγ-producing CD4+ T cells, and IFNγ blockade negated the therapeutic impact of αCTLA-4. The anti-tumor activity of CD4+ T cells did not require tumor-intrinsic MHC-II expression but rather required conventional dendritic cells as well as MHC-II expression on microglia. CD4+ T cells interacted directly with microglia, promoting IFNγ-dependent microglia activation and phagocytosis via the AXL/MER tyrosine kinase receptors, which were necessary for tumor suppression. Thus, αCTLA-4 blockade in mesenchymal-like glioblastoma promotes a CD4+ T cell-microglia circuit wherein IFNγ triggers microglia activation and phagocytosis and microglia in turn act as antigen-presenting cells fueling the CD4+ T cell response.

Transfer of cGAMP into Bystander Cells via LRRC8 Volume-Regulated Anion Channels Augments STING-Mediated Interferon Responses and Anti-viral Immunity.

The enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA in infected and malignant cells and catalyzes the formation of 2'3'cGMP-AMP (cGAMP), which in turn triggers interferon (IFN) production via the STING pathway. Here, we examined the contribution of anion channels to cGAMP transfer and anti-viral defense. A candidate screen revealed that inhibition of volume-regulated anion channels (VRACs) increased propagation of the DNA virus HSV-1 but not the RNA virus VSV. Chemical blockade or genetic ablation of LRRC8A/SWELL1, a VRAC subunit, resulted in defective IFN responses to HSV-1. Biochemical and electrophysiological analyses revealed that LRRC8A/LRRC8E-containing VRACs transport cGAMP and cyclic dinucleotides across the plasma membrane. Enhancing VRAC activity by hypotonic cell swelling, cisplatin, GTPγS, or the cytokines TNF or interleukin-1 increased STING-dependent IFN response to extracellular but not intracellular cGAMP. Lrrc8e-/- mice exhibited impaired IFN responses and compromised immunity to HSV-1. Our findings suggest that cell-to-cell transmission of cGAMP via LRRC8/VRAC channels is central to effective anti-viral immunity.

T Cell Metabolism in a State of Flux.

Our knowledge of T cell metabolism relies primarily on studies performed in vitro that may not fully recapitulate physiological conditions in vivo. In this issue of Immunity, Ma et al. find that the in vivo environment dictates the metabolic phenotype of effector CD8+ T cells-particularly their glucose utilization.

Tyrosine phosphatase SHP-2 mediates C-type lectin receptor-induced activation of the kinase Syk and anti-fungal TH17 responses.

Fungal infection stimulates the canonical C-type lectin receptor (CLR) signaling pathway via activation of the tyrosine kinase Syk. Here we identify a crucial role for the tyrosine phosphatase SHP-2 in mediating CLR-induced activation of Syk. Ablation of the gene encoding SHP-2 (Ptpn11; called 'Shp-2' here) in dendritic cells (DCs) and macrophages impaired Syk-mediated signaling and abrogated the expression of genes encoding pro-inflammatory molecules following fungal stimulation. Mechanistically, SHP-2 operated as a scaffold, facilitating the recruitment of Syk to the CLR dectin-1 or the adaptor FcRγ, through its N-SH2 domain and a previously unrecognized carboxy-terminal immunoreceptor tyrosine-based activation motif (ITAM). We found that DC-derived SHP-2 was crucial for the induction of interleukin 1ß (IL-1ß), IL-6 and IL-23 and anti-fungal responses of the TH17 subset of helper T cells in controlling infection with Candida albicans. Together our data reveal a mechanism by which SHP-2 mediates the activation of Syk in response to fungal infection.

How metabolism bridles cytotoxic CD8+ T cells through epigenetic modifications.

In the direct competition for metabolic resources between cancer cells and tumor-infiltrating CD8+ T cells, the latter are bound to lose out. These effector lymphocytes are therefore rendered exhausted or dysfunctional. Emerging insights into the mechanisms of T cell unresponsiveness in the tumor microenvironment (TME) point towards epigenetic mechanisms as crucial regulatory factors. In this review, we discuss the effects of characteristic components of the TME, i.e. glucose/amino acid dearth with elevated levels of reactive oxygen species (ROS), on DNA methylation and histone modifications in CD8+ T cells. We then take a closer look at the translational potential of epigenetic interventions that aim to improve current immunotherapeutic strategies, including the adoptive transfer of T cell receptor (TCR) or chimeric antigen receptor (CAR) engineered T cells.

The advanced lung cancer inflammation index (ALI) predicted the postoperative survival rate of patients with non-small cell lung cancer and the construction of a nomogram model.

OBJECTIVE: To investigate the prognostic significance of the advanced lung cancer inflammation index (ALI) in patients with operable non-small-cell lung carcinoma (NSCLC). By constructing the nomogram model, it can provide a reference for clinical work. METHODS: A total of 899 patients with non-small cell lung cancer who underwent surgery in our hospital between January 2017 and June 2021 were retrospectively included. ALI was calculated by body mass index (BMI) × serum albumin/neutrophil to lymphocyte ratio (NLR). The optimal truncation value of ALI was obtained using the receiver operating characteristic (ROC) curve and divided into two groups. Survival analysis was represented by the Kaplan-Meier curve. The predictors of Overall survival (OS) were evaluated by the Cox proportional risk model using single factor and stepwise regression multifactor analysis. Based on the results of multi-factor Cox proportional risk regression analysis, a nomogram model was established using the R survival package. The bootstrap method (repeated sampling 1 000 times) was used for internal verification of the nomogram model. The concordance index (C-index) was used to represent the prediction performance of the nomogram model, and the calibration graph method was used to visually represent its prediction conformity. The application value of the model was evaluated by decision curve analysis (DCA). RESULTS: The optimal cut-off value of ALI was 70.06, and the low ALI group (ALI < 70.06) showed a poor survival prognosis. In multivariate analyses, tumor location, pathological stage, neuroaggression, and ALI were independently associated with operable NSCLC-specific survival. The C index of OS predicted by the nomogram model was 0.928 (95% CI: 0.904-0.952). The bootstrap self-sampling method (B = 1000) was used for internal validation of the prediction model, and the calibration curve showed good agreement between the prediction and observation results of 1-year, 2-year, and 3-year OS. The ROC curves for 1-year, 2-year, and 3-year survival were plotted according to independent factors, and the AUC was 0.952 (95% CI: 0.925-0.979), 0.951 (95% CI: 0.916-0.985), and 0.939 (95% CI: 0.913-0.965), respectively. DCA shows that this model has good clinical application value. CONCLUSION: ALI can be used as a reliable indicator to evaluate the prognosis of patients with operable NSCLC, and through the construction of a nomogram model, it can facilitate better individualized treatment and prognosis assessment.

TSC1/mTOR-controlled metabolic-epigenetic cross talk underpins DC control of CD8+ T-cell homeostasis.

Dendritic cells (DCs) play pivotal roles in T-cell homeostasis and activation, and metabolic programing has been recently linked to DC development and function. However, the metabolic underpinnings corresponding to distinct DC functions remain largely unresolved. Here, we demonstrate a special metabolic-epigenetic coupling mechanism orchestrated by tuberous sclerosis complex subunit 1 (TSC1)-mechanistic target of rapamycin (mTOR) for homeostatic DC function. Specific ablation of Tsc1 in the DC compartment (Tsc1DC-KO) largely preserved DC development but led to pronounced reduction in naïve and memory-phenotype cluster of differentiation (CD)8+ T cells, a defect fully rescued by concomitant ablation of mTor or regulatory associated protein of MTOR, complex 1 (Rptor) in DCs. Moreover, Tsc1DC-KO mice were unable to launch efficient antigen-specific CD8+ T effector responses required for containing Listeria monocytogenes and B16 melanomas. Mechanistically, our data suggest that the steady-state DCs tend to tune down de novo fatty acid synthesis and divert acetyl-coenzyme A (acetyl-CoA) for histone acetylation, a process critically controlled by TSC1-mTOR. Correspondingly, TSC1 deficiency elevated acetyl-CoA carboxylase 1 (ACC1) expression and fatty acid synthesis, leading to impaired epigenetic imprinting on selective genes such as major histocompatibility complex (MHC)-I and interleukin (IL)-7. Remarkably, tempering ACC1 activity was able to divert cytosolic acetyl-CoA for histone acetylation and restore the gene expression program compromised by TSC1 deficiency. Taken together, our results uncover a crucial role for TSC1-mTOR in metabolic programing of the homeostatic DCs for T-cell homeostasis and implicate metabolic-coupled epigenetic imprinting as a paradigm for DC specification.

Cardiac-Specific Overexpression of Silent Information Regulator 1 Protects Against Heart and Kidney Deterioration in Cardiorenal Syndrome via Inhibition of Endoplasmic Reticulum Stress.

BACKGROUND/AIMS: Increased endoplasmic reticulum (ER) stress contributes to development of cardiorenal syndrome (CRS), and Silent Information Regulator 1 (SIRT1), a class III histone deacetylase, may have protective effects on heart and renal disease, by reducing ER stress. We aimed to determine if SIRT1 alleviates CRS through ER stress reduction. METHODS: Wild type mice (n=37), mice with cardiac-specific SIRT1 knockout (n=29), or overexpression (n=29), and corresponding controls, were randomized into four groups: sham MI (myocardial infarction) +sham STNx (subtotal nephrectomy); MI+sham STNx; sham MI+STNx; and MI+STNx. To establish the CRS model, subtotal nephrectomy (5/6 nephrectomy, SNTx) and myocardial infarction (MI) (induced by ligation of the left anterior descending (LAD) coronary artery) were performed successively to establish CRS model. At week 8, the mice were sacrificed after sequential echocardiographic and hemodynamic studies, and then pathology and Western-blot analysis were performed. RESULTS: Neither MI nor STNx alone significantly influenced the other healthy organ. However, in MI groups, STNx led to more severe cardiac structural and functional deterioration, with increased remodeling, increased BNP levels, and decreased EF, Max +dp/dt, and Max -dp/dt values than in sham MI +STNx groups. Conversely, in STNx groups, MI led to renal structural and functional deterioration, with more severe morphologic changes, augmented desmin and decreased nephrin expression, and increased BUN, SCr and UCAR levels. In MI+STNx groups, SIRT1 knockout led to more severe cardiac structural and functional deterioration, with higher Masson-staining score and BNP levels, and lower EF, FS, Max +dp/dt, and Max -dp/dt values; while SIRT1 overexpression had the opposite attenuating effects. In kidney, SIRT1 knockout resulted in greater structural and functional deterioration, as evidenced by more severe morphologic changes, higher levels of UACR, BUN and SCr, and increased desmin and TGF-ß expression, while SIRT1 overexpression resulted in less severe morphologic changes and increased nephrin expression without significant influence on BUN or SCr levels. The SIRT1 knockout but not overexpression resulted in increased myocardial expression of CHOP and GRP78. Cardiac-specific SIRT1 knockout or overexpression resulted in increased or decreased renal expression of CHOP, Bax, and p53 respectively. CONCLUSIONS: Myocardial SIRT1 activation appears protective to both heart and kidney in CRS models, probably through modulation of ER stress.

Roles of ST2, IL-33 and BNP in predicting major adverse cardiovascular events in acute myocardial infarction after percutaneous coronary intervention.

This study investigated roles of serum ST2, IL-33 and BNP in predicting major adverse cardiovascular events (MACEs) in acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI). Blood samples were collected from the included AMI patients (n = 180) who underwent PCI. All patients were divided into the MACEs and MACEs-free groups. Enzyme-linked immunosorbent assay was performed to measure serum levels of ST2, IL-33 and BNP. Severity of coronary artery lesion was evaluated by Gensini score. Pearson correlation analysis was used. A receiver operating characteristics curve was drawn to evaluate the potential roles of ST2, IL-33 and BNP in predicting MACEs, and Kaplan-Meier curve to analyse the 1-year overall survival rate. Logistic regression analysis was conducted to analyse the independent risk factors for MACEs. Compared with the MACEs-free group, the serum levels of ST2, IL-33 and BNP were significantly higher in the MACEs group. Serum levels of ST2, IL-33 and BNP were positively correlated with each other and positively correlated with Gensini score. The area under curves of ST2, IL-33 and BNP, respectively, were 0.872, 0.675 and 0.902. The relative sensitivity and specificity were, respectively, 76.27% and 85.92%, 69.49% and 58.68%, as well as, 96.61% and 77.69%. Serum levels of ST2, IL-33 and BNP were independent risk factors for MACEs. The 1-year overall survival rate was higher in AMI patients with lower serum levels of ST2, IL-33 and BNP. In conclusion, serum levels of ST2, IL-33 and BNP have potential value in predicting MACEs in AMI patients undergoing PCI.

Iterative Image Reconstruction Improves the Accuracy of Automated Plaque Burden Assessment in Coronary CT Angiography: A Comparison With Intravascular Ultrasound.

OBJECTIVE: The purpose of this study was to determine whether use of iterative image reconstruction algorithms improves the accuracy of coronary CT angiography (CCTA) compared with intravascular ultrasound (IVUS) in semiautomated plaque burden assessment. MATERIALS AND METHODS: CCTA and IVUS images of seven coronary arteries were acquired ex vivo. CT images were reconstructed with filtered back projection (FBP) and adaptive statistical (ASIR) and model-based (MBIR) iterative reconstruction algorithms. Cross-sectional images of the arteries were coregistered between CCTA and IVUS in 1-mm increments. In CCTA, fully automated (without manual corrections) and semiautomated (allowing manual corrections of vessel wall boundaries) plaque burden assessments were performed for each of the reconstruction algorithms with commercially available software. In IVUS, plaque burden was measured manually. Agreement between CCTA and IVUS was determined with Pearson correlation. RESULTS: A total of 173 corresponding cross sections were included. The mean plaque burden measured with IVUS was 63.39% ± 10.63%. With CCTA and the fully automated technique, it was 54.90% ± 11.70% with FBP, 53.34% ± 13.11% with ASIR, and 55.35% ± 12.22% with MBIR. With CCTA and the semiautomated technique mean plaque burden was 54.90% ± 11.76%, 53.40% ± 12.85%, 57.09% ± 11.05%. Manual correction of the semiautomated assessments was performed in 39% of all cross sections and improved plaque burden correlation with the IVUS assessment independently of reconstruction algorithm (p < 0.0001). Furthermore, MBIR was superior to FBP and ASIR independently of assessment method (semiautomated, r = 0.59 for FBP, r = 0.52 for ASIR, r = 0.78 for MBIR, all p < 0.001; fully automated, r = 0.40 for FBP, r = 0.37 for ASIR, r = 0.53 for MBIR, all p < 0.001). CONCLUSION: For the quantification of plaque burden with CCTA, MBIR led to better correlation with IVUS than did traditional reconstruction algorithms such as FBP, independently of the use of a fully automated or semiautomated assessment approach. The highest accuracy for quantifying plaque burden with CCTA can be achieved by using MBIR data with semiautomated assessment.

Protective Effects of Salvianolate on Contrast-Induced Nephropathy after Primary Percutaneous Coronary Intervention: A Prospective Multicenter Randomized Controlled Trial.

OBJECTIVES: This study's aim was to evaluate the protective effects of salvianolate on contrast-induced nephropathy after primary percutaneous coronary intervention (PPCI) compared with normal saline (NS) hydration. METHODS: We enrolled patients with acute myocardial infarction who underwent PPCI in 3 centers in Shanghai. The patients were randomly assigned to the salvianolate group or the NS group. The incidence of CIN, the changes in renal function parameters, and the occurrence of adverse events after the procedure were compared between the 2 groups. We used a multivariate logistic regression analysis to determine the independent correlates of CIN after PPCI. RESULTS: A total of 484 patients were finally included in the statistical analysis. Compared with the control group, salvianolate reduced the incidence of CIN (9.1 vs. 16.3%, p = 0.018) after PPCI. The renal function parameters after PPCI in the salvianolate group were superior to those of the control group (p < 0.05). The composite adverse events rate was significantly lower in the salvianolate group within 1 month after the procedure (9.5 vs. 15.5%, p = 0.046). A higher peak of troponin I and loop diuretic therapy were the independent correlates of CIN after PPCI. CONCLUSIONS: Salvianolate reduces the incidence of CIN and protects renal function after PPCI, and the effects were superior to those of NS hydration.

The ADP antagonist MRS2179 regulates the phenotype of smooth muscle cells to limit intimal hyperplasia.

PURPOSE: ADP plays an important part in platelet aggregation by activating P2Y1 and P2Y12 receptors. The ADP antagonist MRS2179 has been used in thrombosis-related treatments but its effects on vein graft (VG) remodeling is undefined. We examined the effect of MRS2179 on VG intimal hyperplasia and explored the mechanism of action. METHODS: A mouse model of VG transplantation was established. Mice underwent surgery and received MRS2179 by intraperitoneal injection every other day for 3 weeks. VG remodeling was assessed 4-weeks later. Vascular smooth muscle cells (VSMCs) were isolated and treated with MRS2179. The effect of MRS2179 on the proliferation, migration and inflammatory-cytokine expression of VSMCs was also evaluated. RESULTS: MRS2179 significantly inhibited VSMC proliferation compared with the control group. Significant inhibitory effects of MRS2179 on VSMC migration was observed in two-dimensional and three-dimensional models. The extent of intimal hyperplasia was significantly less in MRS2179 treated mice than in controls. Reduced migration of macrophage was found in MRS2179 treated mice. Expression of the inflammatory cytokines IL-1ß and TNF-α was decreased significantly in the MRS2179 treated group. In addition, decreased phosphorylation was found on Akt, Erk1/2 and p38. CONCLUSIONS: These data demonstrate that MRS2179 inhibits neointima formation in VGs by regulating the proliferation, and migration of VSMCs, macrophage migration, inflammatory-cytokine secretion and related signaling pathway. Our study provides novel insights regarding purinergic signaling in SMCs in vivo. The P2Y1 receptor may serve as a therapeutic target in neointima formation.

Mechanism of luminal patency of the self-expanding Sideguard sidebranch stent: evaluation by intravascular ultrasound and optical coherence tomography.

BACKGROUND: The Cappella Sideguard (CS) sidebranch stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the sidebranch ostium designed to treat bifurcation lesions. OBJECTIVE: To evaluate the mechanism of long-term lumen patency of the novel, self-expanding CS sidebranch stent compared with a balloon-expandable stent in the main vessel. METHODS: We performed intravascular ultrasound postintervention and at follow-up in 24 CS stents and in 28 balloon-expandable drug-eluting stents deployed in the corresponding main vessel. Thirteen patients also had optical coherence tomography (OCT) at follow-up to evaluate neointimal hyperplasia and strut coverage. RESULTS: CS stent area at the sidebranch carina increased significantly from 3.8 ± 1.2 mm(2) postintervention to 4.6 ± 1.2 mm(2) at follow-up (P < 0.001), resulting in no change in lumen area (3.8 ± 1.2 mm(2) to 3.7 ± 1.2 mm(2) , P = 0.72) despite a neointimal area at follow-up of 0.9 ± 0.8 mm(2) . Volumetric changes were similar, and the distribution of neointimal hyperplasia peaked 1-2 mm distal to the carina. Change of lumen volume inversely correlated to the neointimal volume (R = -0.48, P < 0.001), but correlated positively to the change in stent volume (R = 0.52, P < 0.0001). By OCT, most CS struts were covered (100% [98.9, 100]) at the bifurcation site, whereas 61% of floating DES struts that crossed the sidebranch were covered by smooth tissue with a similar texture compared with neointima. CONCLUSION: Although neointimal hyperplasia accumulates within the CS stent mainly 1-2 mm distal to the carina, the self-expanding CS stent may be effective in maintaining an adequate patency in the sidebranch by continued stent expansion noted at follow-up.

Prognostic factors and predictive model construction in patients with non-small cell lung cancer: a retrospective study.

Objective: The purpose of this study was to construct a nomogram model based on the general characteristics, histological features, pathological and immunohistochemical results, and inflammatory and nutritional indicators of patients so as to effectively predict the overall survival (OS) and progression-free survival (PFS) of patients with non-small cell lung cancer (NSCLC) after surgery. Methods: Patients with NSCLC who received surgical treatment in our hospital from January 2017 to June 2021 were selected as the study subjects. The predictors of OS and PFS were evaluated by univariate and multivariable Cox regression analysis using the Cox proportional risk model. Based on the results of multi-factor Cox proportional risk regression analysis, a nomogram model was established using the R survival package. The bootstrap method (repeated sampling for 1 000 times) was used to internally verify the nomogram model, and C-index was used to represent the prediction performance of the nomogram model. The calibration graph method was used to visually represent its prediction compliance, and decision curve analysis (DCA) was used to evaluate the application value of the model. Results: Univariate and multivariate analyses were used to identify independent prognostic factors and to construct a nomogram of postoperative survival and disease progression in operable NSCLC patients, with C-index values of 0.927 (907-0.947) and 0.944 (0.922-0.966), respectively. The results showed that the model had high predictive performance. Calibration curves for 1-year, 2-year, and 3-year OS and PFS show a high degree of agreement between the predicted probability and the actual observed probability. In addition, the results of the DCA curve show that the model has good clinical application value. Conclusion: We established a predictive model of survival prognosis and disease progression in patients with non-small cell lung cancer after surgery, which has good predictive performance and can guide clinicians to make the best clinical decision.

Association between immune-related adverse events and prognosis in patients with advanced non-small cell lung cancer: a systematic review and meta-analysis.

Background: The emergence of immune checkpoint inhibitors (ICIs) provides a variety of options for patients with advanced non-small-cell lung cancer (NSCLC). After the application of ICIs, the immune system of patients was highly activated, and immune-related adverse events (irAEs) could occur in some organ systems, and irAEs seemed to be associated with the survival prognosis of patients. Therefore, we evaluated the association between survival outcomes and irAEs in NSCLC patients and conducted a systematic review and meta-analysis. Methods: We conducted systematic reviews of PubMed, Embase, Cochrane, and Web of Science databases until December 2021. The forest map was constructed by combining the hazard ratio (HR) and 95% confidence interval (CI). I2 estimated the heterogeneity between studies. A meta-analysis was performed using R 4.2.1 software. Results: Eighteen studies included 4808 patients with advanced NSCLC. In pooled analysis, the occurrence of irAEs was found to be a favorable factor for improved prognosis (PFS: HR: 0.48, 95% CI: 0.41-0.55, P <0.01; OS: HR: 0.46, 95% CI: 0.42-0.52, P <0.01). In subgroup analyses, cutaneous irAE, gastrointestinal irAE, endocrine irAE and grade ≥3 irAEs were associated with improvements in PFS and OS, but pulmonary and hepatic irAEs were not. Conclusion: Existing evidence suggests that the occurrence of irAEs may be a prognostic biomarker for advanced NSCLC. However, further research is needed to explore the prospect of irAEs as a prognostic biomarker in patients undergoing immunotherapy. Systematic review registration: https://www.crd.york.ac.uk/PROSPEROFILES/405333_STRATEGY_20240502.pdf, identifier CRD42023405333.

Rapid weather changes are associated with daily hospital visitors for atrial fibrillation accompanied by abnormal ECG repolarization: a case-crossover study.

BACKGROUND: Atrial fibrillation (AF) is highly prevalent in the population, yet the factors contributing to AF events in susceptible individuals remain partially understood. The potential relationship between meteorological factors and AF, particularly with abnormal electrocardiograph (ECG) repolarization, has not been adequately studied. This case-crossover study aims to investigate the association between meteorological factors and daily hospital visits for AF with abnormal ECG repolarization in Shanghai, China. METHODS: The study cohort comprised 10,325 patients with ECG-confirmed AF who sought treatment at Shanghai Sixth People's Hospital between 2015 and 2018. Meteorological and air pollutant concentration data were matched with the patient records. Using a case-crossover design, we analyzed the association between meteorological factors and the daily count of hospital visitors for AF with abnormal ECG repolarization at our AF center. Lag analysis models were applied to examine the temporal relationship between meteorological factors and AF events. RESULTS: The analysis revealed statistically significant associations between AF occurrence and specific meteorological factors. AF events were significantly associated with average atmospheric pressure (lag 0 day, OR 0.9901, 95% CI 0.9825-0.9977, P < 0.05), average temperature (lag 1 day, OR 0.9890, 95% CI 0.9789-0.9992, P < 0.05), daily pressure range (lag 7 days, OR 1.0195, 95% CI 1.0079-1.0312, P < 0.01), and daily temperature range (lag 5 days, OR 1.0208, 95% CI 1.0087-1.0331, P < 0.01). Moreover, a significant correlation was observed between daily pressure range and daily temperature range with AF patients, particularly those with abnormal ECG repolarization, as evident in the case-crossover analysis. CONCLUSION: This study highlights a significant correlation between meteorological factors and daily hospital visits for AF accompanied by abnormal ECG repolarization in Shanghai, China. In addition, AF patients with abnormal ECG repolarization were found to be more vulnerable to rapid daily changes in pressure and temperature compared to AF patients without such repolarization abnormalities.

Intrinsic targeting of host RNA by Cas13 constrains its utility.

Cas13 can be used for the knockdown, editing, imaging or detection of RNA and for RNA-based gene therapy. Here by using RNA immunoprecipitation sequencing, transcriptome profiling, biochemical analysis, high-throughput screening and machine learning, we show that Cas13 can intrinsically target host RNA in mammalian cells through previously unappreciated mechanisms. Different from its known cis/trans RNA-cleavage activity, Cas13 can also cleave host RNA via mechanisms that are transcript-specific, independent of the sequence of CRISPR RNA and dynamically dependent on the conformational state of Cas13, as we show for several Cas13-family effectors encoded in one-vector and two-vector lentiviral systems. Moreover, host genes involved in viral processes and whose transcripts are intrinsically targeted by Cas13 contribute to constraining the lentiviral delivery and expression of Cas13. Our findings offer guidance for the appropriate use of lentiviral Cas13 systems and highlight the need for caution regarding intrinsic RNA targeting in Cas13-based applications.

CRISPR screens reveal convergent targeting strategies against evolutionarily distinct chemoresistance in cancer.

Resistance to chemotherapy has been a major hurdle that limits therapeutic benefits for many types of cancer. Here we systematically identify genetic drivers underlying chemoresistance by performing 30 genome-scale CRISPR knockout screens for seven chemotherapeutic agents in multiple cancer cells. Chemoresistance genes vary between conditions primarily due to distinct genetic background and mechanism of action of drugs, manifesting heterogeneous and multiplexed routes towards chemoresistance. By focusing on oxaliplatin and irinotecan resistance in colorectal cancer, we unravel that evolutionarily distinct chemoresistance can share consensus vulnerabilities identified by 26 second-round CRISPR screens with druggable gene library. We further pinpoint PLK4 as a therapeutic target to overcome oxaliplatin resistance in various models via genetic ablation or pharmacological inhibition, highlighting a single-agent strategy to antagonize evolutionarily distinct chemoresistance. Our study not only provides resources and insights into the molecular basis of chemoresistance, but also proposes potential biomarkers and therapeutic strategies against such resistance.

Intravascular ultrasound comparison of the self-expanding Sideguard stent in the side branch versus a balloon-expandable stent in the main vessel to assess mechanisms of acute lumen gain in bifurcation lesions.

OBJECTIVES: We compared the mechanisms of lumen gain after Cappella Sideguard (CS) side branch (SB) bifurcation stent deployment versus a balloon-expandable stent in the corresponding main vessel (MV). BACKGROUND: The novel CS SB bifurcation stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the SB ostium. METHODS: In 28 bifurcation lesions, intravascular ultrasound imaging of both the SB and the MV was performed both pre- and postintervention; vessel and lumen areas were measured every 1 mm over a 5 mm segment beginning at the carina. RESULTS: Although minimum lumen area (MLA) within the distal 5 mm segment beginning at the carina increased from 2.8 ± 1.3 mm(2) to 3.8 ± 1.1 mm(2), P < 0.001, in the SB and from 3.4 ± 1.4 mm(2) to 6.0 ± 1.1 mm(2), P < 0.001, in the MV, stent expansion (minimum stent area/distal reference lumen area) was significantly less in the SB compared with the MV (77.8 ± 21.3% vs. 91.6 ± 18.4%, P = 0.02). Post stenting, the MLA site was located at the carina more frequently in the SB (85.7%) than in the MV (60.7%), P = 0.04. Plaque volume in the 5 mm proximal to carina in the MV tended to decrease, whereas plaque volume in the SB increased slightly with no change in overall plaque volume in the 5-mm-long segment distal to the carina in the MV, suggesting plaque shift from the proximal MV to the SB. CONCLUSIONS: Acute CS lumen gain is less than the lumen gain of a balloon-expandable stent in the MV because of less aggressive acute expansion and/or the plaque shift from the proximal MV to the SB.