Mitochondrial tRNA pseudouridylation governs erythropoiesis.

Pseudouridine is the most prevalent RNA modification, and its aberrant function is implicated in various human diseases. However, the specific impact of pseudouridylation on hematopoiesis remains poorly understood. In this study, we investigated the role of tRNA pseudouridylation in erythropoiesis and its association with mitochondrial myopathy, lactic acidosis, and sideroblastic anemia syndrome (MLASA) pathogenesis. By utilizing patient-specific induced pluripotent stem cells (iPSCs) carrying a genetic PUS1 mutation and a corresponding mutant mouse model, we demonstrated impaired erythropoiesis in MLASA iPSCs and anemia in the MLASA mouse model. Both MLASA iPSCs and mouse erythroblasts exhibited compromised mitochondrial function and impaired protein synthesis. Mechanistically, we revealed that PUS1 deficiency resulted in reduced mitochondrial tRNA levels due to pseudouridylation loss, leading to aberrant mitochondrial translation. Screening of mitochondrial supplements aimed at enhancing respiration or heme synthesis showed limited effect in promoting erythroid differentiation. Interestingly, the mTOR inhibitor rapamycin facilitated erythroid differentiation in MLASA-iPSCs by suppressing mTOR signaling and protein synthesis, and consistent results were observed in the MLASA mouse model. Importantly, rapamycin treatment effectively ameliorated anemia phenotypes in the MLASA patient. Our findings provide novel insights into the crucial role of mitochondrial tRNA pseudouridylation in governing erythropoiesis and present potential therapeutic strategies for anemia patients facing challenges related to protein translation.

Comparative genomic analysis of the Growth-Regulating Factors-Interacting Factors (GIFs) in six Salicaceae species and functional analysis of PeGIF3 reveals their regulatory role in Populus heteromorphic leaves.

BACKGROUND: The growth-regulating factor-interacting factor (GIF) gene family plays a vital role in regulating plant growth and development, particularly in controlling leaf, seed, and root meristem homeostasis. However, the regulatory mechanism of heteromorphic leaves by GIF genes in Populus euphratica as an important adaptative trait of heteromorphic leaves in response to desert environment remains unknown. RESULTS: This study aimed to identify and characterize the GIF genes in P. euphratica and other five Salicaceae species to investigate their role in regulating heteromorphic leaf development. A total of 27 GIF genes were identified and characterized across six Salicaceae species (P. euphratica, Populus pruinose, Populus deltoides, Populus trichocarpa, Salix sinopurpurea, and Salix suchowensis) at the genome-wide level. Comparative genomic analysis among these species suggested that the expansion of GIFs may be derived from the specific Salicaceae whole-genome duplication event after their divergence from Arabidopsis thaliana. Furthermore, the expression data of PeGIFs in heteromorphic leaves, combined with functional information on GIF genes in Arabidopsis, indicated the role of PeGIFs in regulating the leaf development of P. euphratica, especially PeGIFs containing several cis-acting elements associated with plant growth and development. By heterologous expression of the PeGIF3 gene in wild-type plants (Col-0) and atgif1 mutant of A. thaliana, a significant difference in leaf expansion along the medial-lateral axis, and an increased number of leaf cells, were observed between the overexpressed plants and the wild type. CONCLUSION: PeGIF3 enhances leaf cell proliferation, thereby resulting in the expansion of the central-lateral region of the leaf. The findings not only provide global insights into the evolutionary features of Salicaceae GIFs but also reveal the regulatory mechanism of PeGIF3 in heteromorphic leaves of P. euphratica.

Multi-omics analysis reveals spatiotemporal regulation and function of heteromorphic leaves in Populus.

Despite the high economic and ecological importance of forests, our knowledge of the adaptive evolution of leaf traits remains very limited. Euphrates poplar (Populus euphratica), which has high tolerance to arid environment, has evolved four heteromorphic leaf forms, including narrow (linear and lanceolate) and broad (ovate and broad-ovate) leaves on different crowns. Here, we revealed the significant functional divergence of four P. euphratica heteromorphic leaves at physiological and cytological levels. Through global analysis of transcriptome and DNA methylation across tree and leaf developmental stages, we revealed that gene expression and DNA epigenetics differentially regulated key processes involving development and functional adaptation of heteromorphic leaves, such as hormone signaling pathways, cell division, and photosynthesis. Combined analysis of gene expression, methylation, ATAC-seq, and Hi-C-seq revealed longer interaction of 3D genome, hypomethylation, and open chromatin state upregulates IAA-related genes (such as PIN-FORMED1 and ANGUSTIFOLIA3) and promotes the occurrence of broad leaves while narrow leaves were associated with highly concentrated heterochromatin, hypermethylation, and upregulated abscisic acid pathway genes (such as Pyrabactin Resistance1-like10). Therefore, development of P. euphratica heteromorphic leaves along with functional divergence was regulated by differentially expressed genes, DNA methylation, chromatin accessibility, and 3D genome remodeling to adapt to the arid desert. This study advances our understanding of differential regulation on development and functional divergence of heteromorphic leaves in P. euphratica at the multi-omics level and provides a valuable resource for investigating the adaptive evolution of heteromorphic leaves in Populus.

Single-cell analysis reveals alterations in cellular composition and cell-cell communication associated with airway inflammation and remodeling in asthma.

BACKGROUND: Asthma is a heterogeneous disease characterized by airway inflammation and remodeling, whose pathogenetic complexity was associated with abnormal responses of various cell types in the lung. The specific interactions between immune and stromal cells, crucial for asthma pathogenesis, remain unclear. This study aims to determine the key cell types and their pathological mechanisms in asthma through single-cell RNA sequencing (scRNA-seq). METHODS: A 16-week mouse model of house dust mite (HDM) induced asthma (n = 3) and controls (n = 3) were profiled with scRNA-seq. The cellular composition and gene expression profiles were assessed by bioinformatic analyses, including cell enrichment analysis, trajectory analysis, and Gene Set Enrichment Analysis. Cell-cell communication analysis was employed to investigate the ligand-receptor interactions. RESULTS: The asthma model results in airway inflammation coupled with airway remodeling and hyperresponsiveness. Single-cell analysis revealed notable changes in cell compositions and heterogeneities associated with airway inflammation and remodeling. GdT17 cells were identified to be a primary cellular source of IL-17, related to inflammatory exacerbation, while a subpopulation of alveolar macrophages exhibited numerous significantly up-regulated genes involved in multiple pathways related to neutrophil activities in asthma. A distinct fibroblast subpopulation, marked by elevated expression levels of numerous contractile genes and their regulators, was observed in increased airway smooth muscle layer by immunofluorescence analysis. Asthmatic stromal-immune cell communication significantly strengthened, particularly involving GdT17 cells, and macrophages interacting with fibroblasts. CXCL12/CXCR4 signaling was remarkedly up-regulated in asthma, predominantly bridging the interaction between fibroblasts and immune cell populations. Fibroblasts and macrophages could jointly interact with various immune cell subpopulations via the CCL8/CCR2 signaling. In particular, fibroblast-macrophage cell circuits played a crucial role in the development of airway inflammation and remodeling through IL1B paracrine signaling. CONCLUSIONS: Our study established a mouse model of asthma that recapitulated key pathological features of asthma. ScRNA-seq analysis revealed the cellular landscape, highlighting key pathological cell populations associated with asthma pathogenesis. Cell-cell communication analysis identified the crucial ligand-receptor interactions contributing to airway inflammation and remodeling. Our findings emphasized the significance of cell-cell communication in bridging the possible causality between airway inflammation and remodeling, providing valuable hints for therapeutic strategies for asthma.

Inhibition of growth of hepatocellular carcinoma by co-delivery of anti-PD-1 antibody and sorafenib using biomimetic nano-platelets.

BACKGROUND: Traditional nanodrug delivery systems have some limitations, such as eliciting immune responses and inaccuracy in targeting tumor microenvironments. MATERIALS AND METHODS: Targeted drugs (Sorafenib, Sora) nanometers (hollow mesoporous silicon, HMSN) were designed, and then coated with platelet membranes to form aPD-1-PLTM-HMSNs@Sora to enhance the precision of drug delivery systems to the tumor microenvironment, so that more effective immunotherapy was achieved. RESULTS: These biomimetic nanoparticles were validated to have the same abilities as platelet membranes (PLTM), including evading the immune system. The successful coating of HMSNs@Sora with PLTM was corroborated by transmission electron microscopy (TEM), western blot and confocal laser microscopy. The affinity of aPD-1-PLTM-HMSNs@Sora to tumor cells was stronger than that of HMSNs@Sora. After drug-loaded particles were intravenously injected into hepatocellular carcinoma model mice, they were demonstrated to not only directly activate toxic T cells, but also increase the triggering release of Sora. The combination of targeted therapy and immunotherapy was found to be of gratifying antineoplastic function on inhibiting primary tumor growth. CONCLUSIONS: The aPD-1-PLTM-HMSNs@Sora nanocarriers that co-delivery of aPD-1 and Sorafenib integrates unique biomimetic properties and excellent targeting performance, and provides a neoteric idea for drug delivery of personalized therapy for primary hepatocellular carcinoma (HCC).

Age and incidence of occult pancreaticobiliary reflux in patients with benign gallbladder diseases.

BACKGROUND: Occult pancreaticobiliary reflux (OPBR) has a significant correlation with diseases of the gallbladder and biliary system. This study examined the incidence of OPBR by age in patients with benign gallbladder diseases. METHODS: We assessed 475 patients with benign gallbladder diseases who underwent surgery at Shanghai East Hospital from December 2020 to December 2021. Bile samples collected during surgery were tested for amylase. Patients with bile amylase >110 U/L (n = 64) were classified as the OPBR group; the rest (n = 411) as controls. RESULTS: Of the participants, 375 had gallbladder stone (GS), 170 had gallbladder polyp (GP), and 49 had gallbladder adenomyomatosis (GA). The OPBR group was generally older, with OPBR incidence increasing with age, peaking post-45. Rates by age were: 4.9% (<35), 5.2% (35-44), 20.7% (45-54), 22.5% (55-64) and 17.6% (≥65), mainly in GS patients. ROC analysis for predicting OPBR by age yielded an area under the curve of 0.656, optimal cut-off at 45 years. Logistic regression indicated age > 45, GP, male gender, and BMI ≥ 24 kg*m-2 as independent OPBR predictors in GS patients. Based on these variables, a predictive nomogram was constructed, and its effectiveness was validated using the ROC curve, calibration curve and decision curve analysis (DCA). Further stratification revealed that among GS patients ≤ 45, concurrent GA was an OPBR risk; for > 45, it was GP and male gender. CONCLUSIONS: The incidence of OPBR in GS patients is notably influenced by age, with those over 45, especially males without GP, being at heightened risk.

Identification of changes in bile composition in pancreaticobiliary reflux based on liquid chromatography/mass spectrometry metabolomics.

INTRODUCTION: Pancreaticobiliary reflux (PBR) can induce gallstone formation; however, its pathogenic mechanism remains unclear. In this study, we explored the mechanism of PBR by the non-targeted metabolomic analysis of bile in patients with PBR. OBJECTIVE: The aim of this study was to investigate the pathogenic mechanism in PBR by the non-targeted metabolomic analysis of bile collected during surgery. METHODS: Sixty patients who underwent gallstone surgery at our center from December 2020 to May 2021 were enrolled in the study. According to the level of bile amylase, 30 patients with increased bile amylase ( > 110 U/L) were classified into the PBR group, and the remaining 30 patients were classified into the control group (≤ 110 U/L). The metabolomic analysis of bile was performed. RESULTS: The orthogonal projections to latent structure-discriminant analysis of liquid chromatography mass spectrometry showed significant differences in bile components between the PBR and control groups, and 40 metabolites were screened by variable importance for the projection value (VIP > 1). The levels of phosphatidylcholine (PC) and PC (20:3(8Z,11Z,14Z)/14:0) decreased significantly, whereas the levels of lysoPC (16:1(9z)/0:0), lysoPC (15:0), lysoPC (16:0), palmitic acid, arachidonic acid, leucine, methionine, L-tyrosine, and phenylalanine increased. CONCLUSIONS: Significant differences in bile metabolites were observed between the PBR and control groups. Changes in amino acids and lipid metabolites may be related to stone formation and mucosal inflammation.

Human amniotic epithelial stem cell is a cell therapy candidate for preventing acute graft-versus-host disease.

Graft-versus-host disease (GVHD), an immunological disorder that arises from donor T cell activation through recognition of host alloantigens, is the major limitation in the application of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Traditional immunosuppressive agents can relieve GVHD, but they induce serious side effects. It is highly required to explore alternative therapeutic strategy. Human amniotic epithelial stem cells (hAESCs) were recently considered as an ideal source for cell therapy with special immune regulatory property. In this study, we evaluated the therapeutic role of hAESCs in the treatment of GVHD, based on our previous developed cGMP-grade hAESCs product. Humanized mouse model of acute GVHD (aGVHD) was established by injection of huPBMCs via the tail vein. For prevention or treatment of aGVHD, hAESCs were injected to the mice on day -1 or on day 7 post-PBMC infusion, respectively. We showed that hAESCs infusion significantly alleviated the disease phenotype, increased the survival rate of aGVHD mice, and ameliorated pathological injuries in aGVHD target organs. We demonstrated that hAESCs directly induced CD4+ T cell polarization, in which Th1 and Th17 subsets were downregulated, and Treg subset was elevated. Correspondingly, the levels of a series of pro-inflammatory cytokines were reduced while the levels of the anti-inflammatory cytokines were upregulated in the presence of hAESCs. We found that hAESCs regulated CD4+ subset polarization in a paracrine mode, in which TGFß and PGE2 were selectively secreted to mediate Treg elevation and Th1/Th17 inhibition, respectively. In addition, transplanted hAESCs preserved the graft-versus-leukemia (GVL) effect by inhibiting leukemia cell growth. More intriguingly, hAESCs infusion in HSCT patients displayed potential anti-GVHD effect with no safety concerns and confirmed the immunoregulatory mechanisms in the preclinical study. We conclude that hAESCs infusion is a promising therapeutic strategy for post-HSCT GVHD without compromising the GVL effect. The clinical trial was registered at www.clinicaltrials.gov as #NCT03764228.

Yam Gruel alone and in combination with metformin regulates hepatic lipid metabolism disorders in a diabetic rat model by activating the AMPK/ACC/CPT-1 pathway.

BACKGROUND: As independent and correctable risk factors, disturbances in lipid metabolism are significantly associated with type 2 diabetes mellitus (T2DM). This research investigated the mechanism underlying the lipid-regulating effects of Yam Gruel in diabetic rats. METHODS: First, rats in the control group were given a normal diet, and a diabetic rat model was established via the consumption of a diet that was rich in both fat and sugar for six weeks followed by the intraperitoneal injection of streptozotocin (STZ). After the model was established, the rats were divided into five distinct groups: the control group, model group, Yam Gruel (SYZ) group, metformin (MET) group, and combined group; each treatment was administered for six weeks. The fasting blood glucose (FBG), body and liver weights as well as liver index of the rats were determined. Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), aspartic acid transaminase (AST), alanine aminotransferase (ALT), and nonesterified fatty acid (NEFA) levels were measured. Oil Red O staining was used to assess hepatic steatosis. In addition, the levels of Phospho-acetyl-CoA carboxylase (p-ACC), acetyl coenzyme A carboxylase (ACC), AMP-activated protein kinase (AMPK), Phospho-AMPK (p-AMPK), carnitine palmitoyl transferase I (CPT-1), and Malonyl-CoA decarboxylase (MLYCD) in liver tissues were measured by real-time PCR (q-PCR) and western blotting. RESULTS: After 6 weeks of treatment, Yam Gruel alone or in combination with metformin significantly reduced FBG level, liver weight and index. The concentrations of lipid indices (TG, TC, NEFA, and LDL-C), the levels of liver function indices (ALT and AST) and the degree of hepatic steatosis was improved in diabetic rats that were treated with Yam Gruel with or without metformin. Furthermore, Yam Gruel increased the protein levels of p-ACC/ACC, p-AMPK/AMPK, MLYCD, and CPT-1, which was consistent with the observed changes in gene expression. Additionally, the combination of these two agents was significantly more effective in upregulating the expression of AMPK pathway-related genes and proteins. CONCLUSIONS: These results demonstrated that Yam Gruel may be a potential diet therapy for improving lipid metabolism in T2DM patients and that it may exert its effects via AMPK/ACC/CPT-1 pathway activation. In some respects, the combination of Yam Gruel and metformin exerted more benefits effects than Yam Gruel alone.

Bipartite interaction sites differentially modulate RNA-binding affinity of a protein complex essential for germline stem cell self-renewal.

In C. elegans, PUF proteins promote germline stem cell self-renewal. Their functions hinge on partnerships with two proteins that are redundantly required for stem cell maintenance. Here we focus on understanding how the essential partner protein, LST-1, modulates mRNA regulation by the PUF protein, FBF-2. LST-1 contains two nonidentical sites of interaction with FBF-2, LST-1 A and B. Our crystal structures of complexes of FBF-2, LST-1 A, and RNA visualize how FBF-2 associates with LST-1 A versus LST-1 B. One commonality is that FBF-2 contacts the conserved lysine and leucine side chains in the KxxL motifs in LST-1 A and B. A key difference is that FBF-2 forms unique contacts with regions N- and C-terminal to the KxxL motif. Consequently, LST-1 A does not modulate the RNA-binding affinity of FBF-2, whereas LST-1 B decreases RNA-binding affinity of FBF-2. The N-terminal region of LST-1 B, which binds near the 5' end of RNA elements, is essential to modulate FBF-2 RNA-binding affinity, while the C-terminal residues of LST-1 B contribute strong binding affinity to FBF-2. We conclude that LST-1 has the potential to impact which mRNAs are regulated depending on the precise nature of engagement through its functionally distinct FBF binding sites.

Psychometric Evaluation of the Traditional Chinese Version of the Self-Care of Heart Failure Index Version 7.2.

BACKGROUND: The Self-Care of Heart Failure Index (SCHFI) is a widely used instrument used to measure self-care in both research and clinical settings. The lack of a psychometric evaluation of the traditional Chinese version of the SCHFI (SCHFI-C) might limit its utilization in non-Mainland Chinese populations such as Hong Kong, Macau, and Taiwan. OBJECTIVE: This study aimed to evaluate the psychometric properties of the SCHFI-C v.7.2. METHODS: Participants included 365 adults with heart failure. Breslin's method of translation was used to translate the SCHFI v.7.2 into traditional Chinese. Exploratory factor analysis was conducted to examine the dimensionality structure of each scale. Then, composite reliability was calculated to assess the reliability of 3 scales. Construct validity was examined by hypothesis testing and known-group comparisons. RESULTS: The results of exploratory factor analysis suggest its multidimensionality of each scale. More specifically, the findings indicated a unique internal structure of the self-care maintenance ("lifestyle-related behaviors" and "consulting behaviors") and self-care management ("self-reliance behaviors" and "help-seeking behaviors") scales. The composite reliability of 3 scales were 0.81, 0.88, and 0.82, respectively, reaching adequate level. As for construct validity, the significant associations between the 3 SCHFI domains and self-care confidence as well as significant group difference among patients of different ages and educational backgrounds supported good construct validity. CONCLUSIONS: This study provides evidence of the reliability and validity of the SCHFI-C v.7.2. The traditional SCHFI-C v.7.2 can serve as a valid and reliable outcome measure to evaluate the effects of self-care-promoting interventions.

How do stressful life events affect medical students' academic adjustment? Parallel mediating mechanisms of anxiety and depression.

BACKGROUND: Medical students frequently face challenges in academic adjustment, necessitating effective support and intervention. This study aimed to investigate the impact of stressful life events on medical students' academic adjustment, focusing on the mediating roles of depression and anxiety. It also differentiated the impacts between at-risk students (those with academic failures) and their peers respectively. METHODS: This case-control study involved 320 at-risk medical students and 800 other students from a university in western China. Participants anonymously completed the scales of stressful life events, depression, anxiety, and academic adjustment. T-tests, ANOVA, Pearson correlation, and structural equation modeling were employed for statistical analysis. RESULTS: Depression and anxiety were significantly more prevalent in at-risk students (46.8% and 46.1%, respectively) than in controls (34.0% and 40.3%, respectively). Notably, at-risk students had poorer academic adjustment (t = 5.43, p < 0.001). The structural equation modeling had good fit indices and the results indicated that depression and anxiety fully mediated the effects of stressful life events on academic adjustment. For at-risk students, stressful life events significantly decreased academic adjustment through increased depression and anxiety (p < 0.001). Conversely, anxiety had a positive effect on academic adjustment in other students. CONCLUSION: Targeted interventions focusing on depression and anxiety could reduce the negative impact of stressful life events on medical students' academic adjustment. However, educators have to distinguish the differences between at-risk students and others.

Identification of cough-variant asthma phenotypes based on clinical and pathophysiologic data.

BACKGROUND: Cough-variant asthma (CVA) may respond differently to antiasthmatic treatment. There are limited data on the heterogeneity of CVA. OBJECTIVE: We aimed to classify patients with CVA using cluster analysis based on clinicophysiologic parameters and to unveil the underlying molecular pathways of these phenotypes with transcriptomic data of sputum cells. METHODS: We applied k-mean clustering to 342 newly physician-diagnosed patients with CVA from a prospective multicenter observational cohort using 10 prespecified baseline clinical and pathophysiologic variables. The clusters were compared according to clinical features, treatment response, and sputum transcriptomic data. RESULTS: Three stable CVA clusters were identified. Cluster 1 (n = 176) was characterized by female predominance, late onset, normal lung function, and a low proportion of complete resolution of cough (60.8%) after antiasthmatic treatment. Patients in cluster 2 (n = 105) presented with young, nocturnal cough, atopy, high type 2 inflammation, and a high proportion of complete resolution of cough (73.3%) with a highly upregulated coexpression gene network that related to type 2 immunity. Patients in cluster 3 (n = 61) had high body mass index, long disease duration, family history of asthma, low lung function, and low proportion of complete resolution of cough (54.1%). TH17 immunity and type 2 immunity coexpression gene networks were both upregulated in clusters 1 and 3. CONCLUSION: Three clusters of CVA were identified with different clinical, pathophysiologic, and transcriptomic features and responses to antiasthmatics treatment, which may improve our understanding of pathogenesis and help clinicians develop individualized cough treatment in asthma.

Exploration of potential biomarkers and therapeutic targets for trauma-related acute kidney injury.

PURPOSE: Acute kidney injury (AKI) is one of the most common functional injuries observed in trauma patients. However, certain trauma medications may exacerbate renal injury. Therefore, the early detection of trauma-related AKI holds paramount importance in improving trauma prognosis. METHODS: Qualified datasets were selected from public databases, and common differentially expressed genes related to trauma-induced AKI and hub genes were identified through enrichment analysis and the establishment of protein-protein interaction (PPI) networks. Additionally, the specificity of these hub genes was investigated using the sepsis dataset and conducted a comprehensive literature review to assess their plausibility. The raw data from both datasets were downloaded using R software (version 4.2.1) and processed with the "affy" package19 for correction and normalization. RESULTS: Our analysis revealed 585 upregulated and 629 downregulated differentially expressed genes in the AKI dataset, along with 586 upregulated and 948 downregulated differentially expressed genes in the trauma dataset. Concurrently, the establishment of the PPI network and subsequent topological analysis highlighted key hub genes, including CD44, CD163, TIMP metallopeptidase inhibitor 1, cytochrome b-245 beta chain, versican, membrane spanning 4-domains A4A, mitogen-activated protein kinase 14, and early growth response 1. Notably, their receiver operating characteristic curves displayed areas exceeding 75%, indicating good diagnostic performance. Moreover, our findings postulated a unique molecular mechanism underlying trauma-related AKI. CONCLUSION: This study presents an alternative strategy for the early diagnosis and treatment of trauma-related AKI, based on the identification of potential biomarkers and therapeutic targets. Additionally, this study provides theoretical references for elucidating the mechanisms of trauma-related AKI.

Irreversible repolarization of tumour-associated macrophages by low-Pi stress inhibits the progression of hepatocellular carcinoma.

Numerous studies have shown the positive correlation between high levels of Pi and tumour progression. A critical goal of macrophage-based cancer therapeutics is to reduce anti-inflammatory macrophages (M2) and increase proinflammatory antitumour macrophages (M1). This study aimed to investigate the relationship between macrophage polarization and low-Pi stress. First, the spatial populations of M2 and M1 macrophages in 22 HCC patient specimens were quantified and correlated with the local Pi concentration. The levels of M2 and M1 macrophage markers expressed in the peritumour area were higher than the intratumour levels, and the expression of M2 markers was positively correlated with Pi concentration. Next, monocytes differentiated from THP-1 cells were polarized against different Pi concentrations to investigate the activation or silencing of the expression of p65, IκB-α and STAT3 as well as their phosphorylation. Results showed that low-Pi stress irreversibly repolarizes tumour-associated macrophages (TAMs) towards the M1 phenotype by silencing stat6 and activating p65. Moreover, HepG-2 and SMCC-7721 cells were cultured in conditioned medium to investigate the innate anticancer immune effects on tumour progression. Both cancer cell lines showed reduced proliferation, migration and invasion, as epithelial-mesenchymal transition (EMT) was inactivated. In vivo therapeutic effect on the innate and adaptive immune processes was validated in a subcutaneous liver cancer model by the intratumoural injection of sevelamer. Tumour growth was significantly inhibited by the partial deprivation of intratumoural Pi as the tumour microenvironment under low-Pi stress is more immunostimulatory. The anticancer immune response, activated by low-Pi stress, suggests a new macrophage-based immunotherapeutic modality.

Dual-Level Enhanced Nonradiative Carrier Recombination in Wide-Gap Semiconductors: The Case of Oxygen Vacancy in SiO2.

The conventional single-defect-mediated Shockley-Read-Hall model suggests that the nonradiative carrier recombination rate in wide-band gap (WBG) semiconductors would be negligible because the single-defect level is expected to be either far from valence-band-maximum (VBM) or conduction-band-minimum (CBM), or both. However, this model falls short of elucidating the substantial nonradiative recombination phenomena often observed experimentally across various WBG semiconductors. Owing to more localized nature of defect states inherent to WBG semiconductors, when the defect charge state changes, there is a pronounced structural relaxation around the local defect site. This suggests that a defect at each charge state may exhibit a few distinct local configurations, namely, a stable configuration and a few metastable/transit state configurations. Consequently, a dual-level nonradiative recombination model should more realistically exist in WBG semiconductors. In this model, through the dual-level mechanism, electron and hole trap levels are different from each other and could be closer to the CBM for the electron trap and closer to the VBM for the hole trap, respectively; therefore, this significantly increases the corresponding electron and hole capture rates, enhancing the overall process of nonradiative recombination, and explains the experimental observations. In this work, taking technically important SiO2 as an illustrative example, we introduce the dual-level mechanism to elucidate the mechanism of nonradiative carrier recombination in WBG semiconductors. Our findings demonstrated strong alignment with available experimental data, reinforcing the robustness of our proposed dual-level model. Our fundamental understanding, therefore, provides a clear physical picture of the issue and can also be applied to predict the defect-related nonradiative carrier recombination characteristics in other WBG materials.

Highly Efficient Stable Luminescent Radical-Based X-ray Scintillator.

Stable luminescent radicals are open-shell emitters with unique doublet emission characteristics. This feature makes stable luminescent radicals exhibit widespread application prospects in constructing optical, electrical, and magnetic materials. In this work, a stable luminescent radical-based X-ray scintillator of AuPP-1.0 was prepared, which exhibited a high X-ray excited luminescence (XEL) efficiency as well as excellent stability. A mechanism study showed that the heavy atom of Au in AuPP-1.0 endowed it with effective absorption of X-rays, and the doublet emission characteristics of AuPP-1.0 significantly increased its exciton utilization rate in the radioluminescence process. Moreover, AuPP-1.0 has good processability to fabricate a flexible screen for high-quality X-ray imaging, whose resolution can reach 20 LP mm-1. This work demonstrates that the doublet emission is beneficial for improving the exciton utilization rate of radioluminescence, providing a brand-new strategy for the construction of high-performance X-ray scintillators.

Single-Cell Landscape of Lungs Reveals Key Role of Neutrophil-Mediated Immunopathology during Lethal SARS-CoV-2 Infection.

Due to the limitation of human studies with respect to individual difference or the accessibility of fresh tissue samples, how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in pathological complications in lung, the main site of infection, is still incompletely understood. Therefore, physiologically relevant animal models under realistic SARS-CoV-2 infection conditions would be helpful to our understanding of dysregulated inflammation response in lung in the context of targeted therapeutics. Here, we characterized the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicates human symptoms, including severe lung pathology and lymphopenia. We showed a reduction of lymphocyte populations and an increase of neutrophils in lung and then demonstrated the key role of neutrophil-mediated lung immunopathology in both mice and humans. Under severe conditions, neutrophils recruited by a chemokine-driven positive feedback produced elevated "fatal signature" proinflammatory genes and pathways related to neutrophil activation or releasing of granular content. In addition, we identified a new Cd177high cluster that is undergoing respiratory burst and Stfahigh cluster cells that may dampen antigen presentation upon infection. We also revealed the devastating effect of overactivated neutrophil by showing the highly enriched neutrophil extracellular traps in lung and a dampened B-cell function in either lung or spleen that may be attributed to arginine consumption by neutrophil. The current study helped our understanding of SARS-CoV-2-induced pneumonia and warranted the concept of neutrophil-targeting therapeutics in COVID-19 treatment. IMPORTANCE We demonstrated the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicated human symptoms, including severe lung pathology and lymphopenia. Our comprehensive study revealed the key role of neutrophil-mediated lung immunopathology in SARS-CoV-2-induced severe pneumonia, which not only helped our understanding of COVID-19 but also warranted the concept of neutrophil targeting therapeutics in COVID-19 treatment.

CircKDM5B sponges miR-128 to regulate porcine blastocyst development by modulating trophectoderm barrier function.

Circular RNAs (circRNAs), which exert critical functions in the regulation of transcriptional and post-transcriptional gene expression, are found in mammalian cells but their functions in mammalian preimplantation embryo development remain poorly understood. Here, we showed that circKDM5B mediated miRNA-128 (miR-128) to regulate porcine early embryo development. We screened circRNAs potentially expressed in porcine embryos through an integrated analysis of sequencing data from mouse and human embryos, as well as porcine oocytes. An authentic circRNA originating from histone demethylase KDM5B (referred to as circKDM5B) was abundantly expressed in porcine embryos. Functional studies revealed that circKDM5B knockdown not only significantly reduced blastocyst formation but also decreased the number of total cells and trophectoderm (TE) cells. Moreover, the knockdown of circKDM5B resulted in the disturbance of tight junction assembly and impaired paracellular sealing within the TE epithelium. Mechanistically, miR-128 inhibitor injection could rescue the early development of circKDM5B knockdown embryos. Taken together, the findings revealed that circKDM5B functions as a miR-128 sponge, thereby facilitating early embryonic development in pigs through the modulation of gene expression linked to tight junction assembly.

AI-algorithm-assisted 895-nm praseodymium laser emitting sub-100-fs pulses.

Praseodymium (Pr) lasers have achieved outstanding pico- and sub-picosecond pulsations covering the near-infrared (NIR) and visible spectral range in recent years. However, it has been a stagnant task for more than two decades to leapfrog into the sub-100 femtosecond (fs) regime as the Pr gain bandwidths are too narrow for their major transition lines. Although the wide tunability at the NIR bands in the Pr:YLF crystals has been explored, the spectral tails in these transitions suffer severely from weak gains for mode locking, combined with the intricate dispersion control to achieve transform-limit formation. In this work, we target the Pr:YLF's 895-nm line with a specially designed edge-pass filter to balance the gain bandwidth and transitional strength. By deploying a symmetric dispersion scheme and tuning with the soft actor-critic artificial intelligence (AI) algorithm, we have achieved the pulse duration down to sub-100-fs in a Pr laser for the first time. This work also enriches the AI-assisted methodology for ultrafast solid-state laser realizations.