Dynamic immunoediting by macrophages in homologous recombination deficiency-stratified pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, notably resistant to existing therapies. Current research indicates that PDAC patients deficient in homologous recombination (HR) benefit from platinum-based treatments and poly-ADP-ribose polymerase inhibitors (PARPi). However, the effectiveness of PARPi in HR-deficient (HRD) PDAC is suboptimal, and significant challenges remain in fully understanding the distinct characteristics and implications of HRD-associated PDAC. We analyzed 16 PDAC patient-derived tissues, categorized by their homologous recombination deficiency (HRD) scores, and performed high-plex immunofluorescence analysis to define 20 cell phenotypes, thereby generating an in-situ PDAC tumor-immune landscape. Spatial phenotypic-transcriptomic profiling guided by regions-of-interest (ROIs) identified a crucial regulatory mechanism through localized tumor-adjacent macrophages, potentially in an HRD-dependent manner. Cellular neighborhood (CN) analysis further demonstrated the existence of macrophage-associated high-ordered cellular functional units in spatial contexts. Using our multi-omics spatial profiling strategy, we uncovered a dynamic macrophage-mediated regulatory axis linking HRD status with SIGLEC10 and CD52. These findings demonstrate the potential of targeting CD52 in combination with PARPi as a therapeutic intervention for PDAC.

Deep Generative Adversarial Reinforcement Learning for Semi-Supervised Segmentation of Low-Contrast and Small Objects in Medical Images.

Deep reinforcement learning (DRL) has demonstrated impressive performance in medical image segmentation, particularly for low-contrast and small medical objects. However, current DRL-based segmentation methods face limitations due to the optimization of error propagation in two separate stages and the need for a significant amount of labeled data. In this paper, we propose a novel deep generative adversarial reinforcement learning (DGARL) approach that, for the first time, enables end-to-end semi-supervised medical image segmentation in the DRL domain. DGARL ingeniously establishes a pipeline that integrates DRL and generative adversarial networks (GANs) to optimize both detection and segmentation tasks holistically while mutually enhancing each other. Specifically, DGARL introduces two innovative components to facilitate this integration in semi-supervised settings. First, a task-joint GAN with two discriminators links the detection results to the GAN's segmentation performance evaluation, allowing simultaneous joint evaluation and feedback. This ensures that DRL and GAN can be directly optimized based on each other's results. Second, a bidirectional exploration DRL integrates backward exploration and forward exploration to ensure the DRL agent explores the correct direction when forward exploration is disabled due to lack of explicit rewards. This mitigates the issue of unlabeled data being unable to provide rewards and rendering DRL unexplorable. Comprehensive experiments on three generalization datasets, comprising a total of 640 patients, demonstrate that our novel DGARL achieves 85.02% Dice and improves at least 1.91% for brain tumors, achieves 73.18% Dice and improves at least 4.28% for liver tumors, and achieves 70.85% Dice and improves at least 2.73% for pancreas compared to the ten most recent advanced methods, our results attest to the superiority of DGARL. Code is available at GitHub.

Position-based anchor optimization for point supervised dense nuclei detection.

Nuclei detection is one of the most fundamental and challenging problems in histopathological image analysis, which can localize nuclei to provide effective computer-aided cancer diagnosis, treatment decision, and prognosis. The fully-supervised nuclei detector requires a large number of nuclei annotations on high-resolution digital images, which is time-consuming and needs human annotators with professional knowledge. In recent years, weakly-supervised learning has attracted significant attention in reducing the labeling burden. However, detecting dense nuclei of complex crowded distribution and diverse appearances remains a challenge. To solve this problem, we propose a novel point-supervised dense nuclei detection framework that introduces position-based anchor optimization to complete morphology-based pseudo-label supervision. Specifically, we first generate cellular-level pseudo labels (CPL) for the detection head via a morphology-based mechanism, which can help to build a baseline point-supervised detection network. Then, considering the crowded distribution of the dense nuclei, we propose a mechanism called Position-based Anchor-quality Estimation (PAE), which utilizes the positional deviation between an anchor and its corresponding point label to suppress low-quality detections far from each nucleus. Finally, to better handle the diverse appearances of nuclei, an Adaptive Anchor Selector (AAS) operation is proposed to automatically select positive and negative anchors according to morphological and positional statistical characteristics of nuclei. We conduct comprehensive experiments on two widely used benchmarks, MO and Lizard, using ResNet50 and PVTv2 as backbones. The results demonstrate that the proposed approach has superior capacity compared with other state-of-the-art methods. In particularly, in dense nuclei scenarios, our method can achieve 95.1% performance of the fully-supervised approach. The code is available at https://github.com/NucleiDet/DenseNucleiDet.

Mutant KRAS Mediates circARFGEF2 Biogenesis to Promote Lymphatic Metastasis of Pancreatic Ductal Adenocarcinoma.

Circular RNAs (circRNA) contribute to cancer stemness, proliferation, and metastasis. The biogenesis of circRNAs can be impacted by the genetic landscape of tumors. Herein, we identified a novel circRNA, circARFGEF2 (hsa_circ_0060665), which was upregulated in KRASG12D pancreatic ductal adenocarcinoma (PDAC) and positively associated with KRASG12D PDAC lymph node (LN) metastasis. CircARFGEF2 overexpression significantly facilitated KRASG12D PDAC LN metastasis in vitro and in vivo. Mechanistically, circARFGEF2 biogenesis in KRASG12D PDAC was significantly activated by the alternative splicing factor QKI-5, which recruited U2AF35 to facilitate spliceosome assembly. QKI-5 bound the QKI binding motifs and neighboring reverse complement sequence in intron 3 and 6 of ARFGEF2 pre-mRNA to facilitate circARFGEF2 biogenesis. CircARFGEF2 sponged miR-1205 and promoted the activation of JAK2, which phosphorylated STAT3 to trigger KRASG12D PDAC lymphangiogenesis and LN metastasis. Importantly, circARFGEF2 silencing significantly inhibited LN metastasis in the KrasG12D/+Trp53R172H/+Pdx-1-Cre (KPC) mouse PDAC model. These findings provide insight into the mechanism and metastasis-promoting function of mutant KRAS-mediated circRNA biogenesis. SIGNIFICANCE: Increased splicing-mediated biogenesis of circARFGEF2 in KRAS-mutant pancreatic ductal adenocarcinoma activates JAK2-STAT3 signaling and triggers lymph node metastasis, suggesting circARFGEF2 could be a therapeutic target to inhibit pancreatic cancer progression.

Ligustrazine exerts neuroprotective effects via circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury.

BACKGROUND: Ligustrazine is a traditional Chinese herbal medicine that has long been used to treat cerebral ischemic disorders. However, the molecular mechanisms of ligustrazine in cerebral ischemia/reperfusion (I/R) damage have not been clear elucidated. The aim of this study was to examine the neuroprotective mechanisms of ligustrazine in cerebral I/R. METHODS: 9 C57BL/6 mice were randomly divided to three groups: Sham group (n = 3), Middle cerebral artery occlusion (MCAO) group (n = 3), and MCAO + Ligustrazine group (n = 3). The neurological deficit score was evaluated, the cerebral infarct volume was measured by triphenylterazolium chloride (TTC) staining. Differentially expressed (DE) messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) were analyzed using the R package DEseq2 based on P-value < 0.05 and Log2 |fold change (FC)| ≥ 2 in sham group vs MCAO group and MCAO group vs ligustrazine group by high-throughput sequencing. Function enrichment analysis, the protein-protein interaction (PPI) of neurogenesis related genes were performed. The neurogenesis related competitive endogenous RNA (ceRNA) network was constructed. RESULTS: The expression of circ_0008146 was considerably higher in the MCAO group than the Sham group, and ligustrazine treatment markedly decreased the expression of circ_0008146 in MCAO. Next, the circ_0008146 ceRNA network was established, including circ_0008146-miR-709-Cx3cr1 ceRNA network. Besides, real time quantitative polymerase chain reaction (RT-qPCR) assay identified that miR-709 expression was considerably lower and Cx3cr1 expression was higher in the MCAO group than Sham group, and ligustrazine treatment markedly increased the miR-709 expression and reduced Cx3cr1 expression in MCAO. Further, silencing of circ_0008146 inhibited the concentration of Interleukin 6 (IL-6), Tumor Necrosis Factor alpha (TNF-α) and reduced neuron cell death and up-regulated miR-709 expression and down-regulated Cx3cr1 expression in Lipopolysaccharide (LPS) induced BV-2 cells. Dual-Luciferase reporter gene assay verified that circ_0008146 targeted miR-709. CONCLUSION: Ligustrazine targets circ_0008146/miR-709/Cx3cr1 axis to inhibit cell apoptosis and inflammation after cerebral ischemia/reperfusion injury.

KRAS mutant-driven SUMOylation controls extracellular vesicle transmission to trigger lymphangiogenesis in pancreatic cancer.

Lymph node (LN) metastasis occurs frequently in pancreatic ductal adenocarcinoma (PDAC) and predicts poor prognosis for patients. The KRASG12D mutation confers an aggressive PDAC phenotype that is susceptible to lymphatic dissemination. However, the regulatory mechanism underlying KRASG12D mutation-driven LN metastasis in PDAC remains unclear. Herein, we found that PDAC with the KRASG12D mutation (KRASG12D PDAC) sustained extracellular vesicle-mediated (EV-mediated) transmission of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) in a SUMOylation-dependent manner and promoted lymphangiogenesis and LN metastasis in vitro and in vivo. Mechanistically, hnRNPA1 bound with SUMO2 at the lysine 113 residue via KRASG12D-induced hyperactivation of SUMOylation, which enabled its interaction with TSG101 to enhance hnRNPA1 packaging and transmission via EVs. Subsequently, SUMOylation induced EV-packaged-hnRNPA1 anchoring to the adenylate- and uridylate-rich elements of PROX1 in lymphatic endothelial cells, thus stabilizing PROX1 mRNA. Importantly, impeding SUMOylation of EV-packaged hnRNPA1 dramatically inhibited LN metastasis of KRASG12D PDAC in a genetically engineered KrasG12D/+ Trp53R172H/+ Pdx-1-Cre (KPC) mouse model. Our findings highlight the mechanism by which KRAS mutant-driven SUMOylation triggers EV-packaged hnRNPA1 transmission to promote lymphangiogenesis and LN metastasis, shedding light on the potential application of hnRNPA1 as a therapeutic target in patients with KRASG12D PDAC.

Aberrant Nuclear Export of circNCOR1 Underlies SMAD7-Mediated Lymph Node Metastasis of Bladder Cancer.

Circular RNAs (circRNA) containing retained introns are normally sequestered in the nucleus. Dysregulation of cellular homeostasis can drive their nuclear export, which may be involved in cancer metastasis. However, the mechanism underlying circRNA nuclear export and its role in lymph node (LN) metastasis of bladder cancer remain unclear. Here, we identify an intron-retained circRNA, circNCOR1, that is significantly downregulated in LN metastatic bladder cancer and is negatively associated with poor prognosis of patients. Overexpression of circNCOR1 inhibited lymphangiogenesis and LN metastasis of bladder cancer in vitro and in vivo. Nuclear circNCOR1 epigenetically promoted SMAD7 transcription by increasing heterogeneous nuclear ribonucleoprotein L (hnRNPL)-induced H3K9 acetylation in the SMAD7 promoter, leading to inhibition of the TGFß-SMAD signaling pathway. Nuclear retention of circNCOR1 was regulated by small ubiquitin-like modifier (SUMO)ylation of DDX39B, an essential regulatory factor responsible for circRNA nuclear-cytoplasmic transport. Reduced SUMO2 binding to DDX39B markedly increased circNCOR1 retention in the nucleus to suppress bladder cancer LN metastasis. By contrast, SUMOylated DDX39B activated nuclear export of circNCOR1, impairing the suppressive role of circNCOR1 on TGFß-SMAD cascade activation and bladder cancer LN metastasis. In patient-derived xenograft (PDX) models, overexpression of circNCOR1 and inhibition of TGFß signaling significantly repressed tumor growth and LN metastasis. This study highlights SUMOylation-induced nuclear export of circNCOR1 as a key event regulating TGFß-SMAD signaling and bladder cancer lymphangiogenesis, thus supporting circNCOR1 as a novel therapeutic agent for patients with LN metastatic bladder cancer. SIGNIFICANCE: This study identifies the novel intron-retained circNCOR1 and elucidates a SUMOylation-mediated DDX39B-circNCOR1-SMAD7 axis that regulates lymph node metastasis of bladder cancer.

Deep Learning-Based Artificial Intelligence System for Automatic Assessment of Glomerular Pathological Findings in Lupus Nephritis.

Accurate assessment of renal histopathology is crucial for the clinical management of patients with lupus nephritis (LN). However, the current classification system has poor interpathologist agreement. This paper proposes a deep convolutional neural network (CNN)-based system that detects and classifies glomerular pathological findings in LN. A dataset of 349 renal biopsy whole-slide images (WSIs) (163 patients with LN, periodic acid-Schiff stain, 3906 glomeruli) annotated by three expert nephropathologists was used. The CNN models YOLOv4 and VGG16 were employed to localise the glomeruli and classify glomerular lesions (slight/severe impairments or sclerotic lesions). An additional 321 unannotated WSIs from 161 patients were used for performance evaluation at the per-patient kidney level. The proposed model achieved an accuracy of 0.951 and Cohen's kappa of 0.932 (95% CI 0.915-0.949) for the entire test set for classifying the glomerular lesions. For multiclass detection at the glomerular level, the mean average precision of the CNN was 0.807, with 'slight' and 'severe' glomerular lesions being easily identified (F1: 0.924 and 0.952, respectively). At the per-patient kidney level, the model achieved a high agreement with nephropathologist (linear weighted kappa: 0.855, 95% CI: 0.795-0.916, p < 0.001; quadratic weighted kappa: 0.906, 95% CI: 0.873-0.938, p < 0.001). The results suggest that deep learning is a feasible assistive tool for the objective and automatic assessment of pathological LN lesions.

Exploring Task Structure for Brain Tumor Segmentation from Multi-modality MR Images.

Brain tumor segmentation, which aims at segmenting the whole tumor area, enhancing tumor core area, and tumor core area from each input multi-modality bioimaging data, has received considerable attention from both academia and industry. However, the existing approaches usually treat this problem as a common semantic segmentation task without taking into account the underlying rules in clinical practice. In reality, physicians tend to discover different tumor areas by weighing different modality volume data. Also, they initially segment the most distinct tumor area, and then gradually search around to find the other two. We refer to the first property as the task-modality structure while the second property as the task-task structure, based on which we propose a novel task-structured brain tumor segmentation network (TSBTS net). Specifically, to explore the task-modality structure, we design a modality-aware feature embedding mechanism to infer the important weights of the modality data during network learning. To explore the tasktask structure, we formulate the prediction of the different tumor areas as conditional dependency sub-tasks and encode such dependency in the network stream. Experiments on BraTS benchmarks show that the proposed method achieves superior performance in segmenting the desired brain tumor areas while requiring relatively lower computational costs, compared to other state-of-the-art methods and baseline models.

Efficacy of Statin Therapy Related to Baseline Renal Function in Patients with Rheumatic Heart Disease Undergoing Cardiac Surgery.

BACKGROUND: Renal impairment increases the risk of cardiovascular events and perioperative complications in patients with heart valve disease. This study aimed to determine the perioperative benefit of statin treatment related to baseline renal function in patients with rheumatic heart disease (RHD) who had cardiac surgery. METHODS AND RESULTS: We performed a retrospective study on 136 patients with RHD who underwent valve replacement surgery. The mean age of the patients was 56.2 years, 59.6% were female, 8.8% patients had diabetes mellitus, and 27.2% of patients had hypertension. Overall, 3 patients died, 2 underwent reoperation, and 25 underwent thoracentesis during the study period. For patients with renal impairment, there was a higher risk of thoracic puncture (odds ratio [OR]: 3.33; 95% confidence interval [CI]: 1.36, 8.11; P < 0.01) and a longer time of drainage (difference in means: 1; 95% CI: 0.88, 1.12; P < 0.01), intensive care unit (ICU) stay (difference in means: 0.2; 95% CI: 0.17, 0.23; P = 0.02), and hospital stay (difference in means: 6.6; 95% CI: 6.15, 7.05; P < 0.01) compared with normal renal function. Furthermore, statins were associated with a reduction in drainage time (difference in means: -1.50; 95% CI: -1.86, -1.14; P = 0.02), ICU stay (difference in means: -0.30; 95% CI: -0.40, -0.20; P = 0.05), and hospital stay (difference in means: -5.40; 95% CI: -6.57, -4.23; P < 0.01) in patients with renal impairment (interaction, P ≤ 0.05 for all), but not in those with normal renal function. CONCLUSION: Statins have a greater clinical benefit in perioperative cardiac surgery with renal impairment. Statins are associated with a comparatively lower risk of thoracic puncture, as well as a reduced trend toward a reduction in drainage time, ICU stay, and hospital stay.

Safety and efficacy of the perioperative administration of recombinant human brain natriuretic peptide (rhBNP): a systematic review and meta-analysis.

OBJECTIVE: Retrospective studies and a meta-analysis were performed to evaluate the safety and effectiveness of the perioperative administration of recombinant human brain natriuretic peptide (rhBNP) during cardiac surgery under extracorporeal circulation. METHODS: Computerized literature searches were performed in Medline, Embase, The Cochrane Library, CNKI, CBM, and WANFANG to find randomized controlled trials (RCTs) related to the perioperative administration of rhBNP during cardiac surgery starting from the database inception until December 2016. Two researchers independently performed study screening, information extraction, and quality evaluation according to the inclusion/exclusion criteria, and a meta-analysis was performed using RevMan 5.2 software. RESULTS: A total of 12 studies were analyzed, including 12 RCTs and 727 patients. The meta-analysis results indicated that the perioperative administration of rhBNP could reduce the occurrence rate of postoperative complications, length of intensive care unit (ICU) stay, length of hospital stay, and serum creatinine (Scr) levels, and increase the 24-hour urine volume; however, it did not affect the postoperative mortality rate. CONCLUSION: The perioperative administration of rhBNP during cardiac surgery was safe and effective, and could improve the prognosis of the patients.

Efficacy and Mechanism of Preoperative Simvastatin Therapy on Myocardial Protection after Extracorporeal Circulation.

BACKGROUND: Cardiopulmonary bypass (CPB) causes systemic inflammatory response and ischemia-reperfusion (IR) injury. OBJECTIVE: To investigate the effect and mechanism of simvastatin on myocardial injury in cardiac valve surgery with CPB. METHODS: One hundred thirty patients were randomly assigned to the statin group (n = 65) or control group (n = 65). Simvastatin was administered preoperatively and postoperatively. Duration of intensive care unit stay, duration of assisted ventilation, and left ventricular ejection fraction were recorded. Plasma was analysed for troponin T (cTnT), isoenzyme of creatine kinase (CK-MB), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8). Ultrastructure of the myocardium and autophagosomes were observed. Beclin-1, LC3-II/I, P62, AMPK, and the phosphorylation of AMPK in cardiomyocytes were detected. RESULTS: Simvastatin significantly reduced the duration of assisted ventilation (P = 0.030) and ejection fraction was significantly higher in the statin group (P = 0.024). Simvastatin significantly reduced the levels of cTnT, CK-MB, TNF-α, IL-6, and IL-8 (P < 0.05), reduced the expression of LC3-II/LC3-I and Beclin 1, and increased the expression of phosphorylation of AMPK. Simvastatin reduced the generation of autophagosomes and the ultrastructural injuries to myocardium. CONCLUSION: Perioperative statin therapy reduced myocardial injury by regulating myocardial autophagy and activating the phosphorylation of AMPK. The registration number of this study is ChiCTR-TRC-14005164.

Preliminary research on DNA methylation changes during murine palatogenesis induced by TCDD.

2,3,7,8-Tetrachlrodibenzo-p-dioxin (TCDD) has been shown to induce cleft palate through growth factor and receptor expression changes during palatogenesis. DNA methylation is an important epigenetic modification that can regulate gene expressions and may be involved in TCDD-induced cleft palate. In this study, we investigated the effects of TCDD on the global and CpG DNA methylation status and the expression levels of DNA methyltransferases (Dnmts) in palate tissue of fetal mice. Pregnant C57BL/6J mice were administered with corn oil or TCDD 28 µg/kg at gestation day 10.5(GD10.5), and sacrificed at GD13.5, 14.5, 15.5. Fetal palates were collected for molecular analysis. Global DNA methylation status was detected by Methylamp™ Global DNA Methylation Quantification Ultra Kit. The expression of DNA methyltransferases were examined by quantitative real-time PCR(q-PCR). Methylation Specific PCR (MSP) was performed to analyze CpG methylation status of Dnmts. We found that the global DNA methylation level and the expression of Dnmt3a were higher at GD13.5 in the TCDD group. The methylation level of CpG site 2 in the promoter region of Dnmt3a in the control group was higher than that of the TCDD group at GD13.5. The low CpG methylation level of Dnmt3a at GD13.5 which causes the up-expression of Dnmt3a may induce global hypermethylation in fetal palate tissue. The aberrant global methylation status at GD13.5 may be the cause of palate malformation in fetal mice induced by TCDD.