Background: Non-small cell lung cancer (NSCLC) is the predominant lung cancer subtype with high mortality rate. Drug resistance and immune evasion limit its therapeutic outcomes. Specific mechanism of the oncogenic ZFP36L1 in NSCLC remains unclear.
Methods: scRNA-seq data were analysed using bioinformatic approaches. Hypoxia-induced alterations in the macrophage CXCL9:SPP1 ratio were assessed by qRT-PCR, Western blot (WB), immunofluorescence, flow cytometry and ELISA. Dual-luciferase reporter and ChIP assays were used to validate ZFP36L1-mediated transcriptional regulation of SPP1. In a co-cultivation system of macrophages and NSCLC cells, tumour cell malignancy was evaluated through flow cytometry, CCK-8, Transwell, colony formation and scratch assays. Patient-derived organoids co-cultured with macrophages were analysed via H&E, EdU and CellTiter-Glo assays for pathological changes, proliferation and viability, as well as qRT-PCR and WB for the expression of apoptosis-related proteins. Finally, through a macrophage-specific ZFP36L1-knockout mouse model, the function of ZFP36L1 in CXCL9:SPP1 polarity and NSCLC progression was validated in vivo.
Results: Hypoxia induced an imbalanced macrophage CXCL9:SPP1 ratio, with more pro-tumour SPP1+ macrophages and fewer anti-tumour CXCL9+ macrophages. Upregulation of ZFP36L1 promoted macrophage polarisation towards the SPP1+ phenotype, which then bound to CD44 on tumour cells to accelerate NSCLC progression.
Conclusion: Under hypoxia, ZFP36L1 transcriptionally regulates SPP1 to reduce the macrophage CXCL9:SPP1 ratio, thereby driving NSCLC malignancy.
Background: Breast malignant phyllodes tumours are rare fibroepithelial neoplasms arising from periductal stromal cells, characterized by rapid progression and a high recurrence rate. The poor prognosis largely stems from the lack of effective therapeutic strategies, underscoring the insufficient understanding of their molecular mechanisms and therapeutic targets. Moreover, most previous studies have mainly focused on the tumour core, while the molecular features of the surrounding peritumoural tissue remain insufficiently explored.
Methods: To address this problem, we collected 66 phyllodes tumour specimens from 22 patients, including benign, borderline and malignant subtypes. For each case, paired samples were obtained from the tumour core and peritumoural regions. Multi-regional genomic, transcriptomic and digital pathology analyses were performed to characterize spatial patterns of tumour evolution. In addition, multiplex immunofluorescence was applied to validate the spatial distribution of key cellular and molecular features.
Results: Malignant phyllodes tumours exhibited markedly enhanced proliferative activity compared with benign and borderline counterparts. Malignant tumours were also characterized by a distinctly immune activated peritumoural niche encasing an immune excluded tumour core. Specifically, the peritumoural regions displayed abundant lymphocyte infiltration and close immune cell clustering, whereas the intratumoral compartments were largely devoid of immune cells. Enhanced angiogenesis and collagen remodelling were observed in the peritumoural compartment. In malignant phyllodes tumour patients, a more pronounced spatial immune segregation phenotype may be associated with a lower risk of recurrence.
Conclusion: These results provide an integrated view of phyllodes tumour progression and identify immune exclusion as a defining feature of malignancy. The unique biological characteristics of the peritumoural region may serve as valuable therapeutic targets, offering potential for combined anti-angiogenesis agents and immunotherapy strategies to overcome the immune excluded microenvironment of malignant phyllodes tumours.
Background: A multi-centre, 2-part, phase II study assessed adding rezvilutamide (a novel androgen receptor antagonist) to docetaxel in abiraterone-refractory, metastatic castration-resistant prostate cancer (mCRPC) patients who were naive to chemotherapy. Herein, we report results from part 1.
Methods: Part 1 encompassed both dose-escalation and dose-expansion phases. Eligible patients received oral rezvilutamide (160/240 mg, once daily [QD]) plus intravenous docetaxel (75 mg/m2, on the first day of every 3-week cycle) for more than 10 cycles, followed by maintenance with rezvilutamide monotherapy (240 mg, QD). Rezvilutamide was administered daily starting from the second day of cycle 1. Docetaxel was co-administered with oral prednisone at 5 mg twice daily. Safety served as the primary objective in Part 1.
Results: From 2, December 2020, to 5, August 2021, 36 patients were eligible for enrolment (18 patients with rezvilutamide 160 mg plus docetaxel and 18 patients with rezvilutamide 240 mg plus docetaxel). No one experienced dose-limiting toxicity. 32 (88.9%) patients experienced grade 3 or higher treatment-related adverse events. At week 12, 67.7% of the 31 evaluable patients showed a response in prostate-specific antigen (PSA) levels. Among all 36 patients, the median times were 10.5 months (95% CI: 5.6–14.1) for PSA progression, 13.8 months (95% CI: 8.4–19.2) for radiological progression-free survival and 16.2 months (95% CI: 12.9–22.5) for overall survival. The limitations were a small sample size and a non-randomised design.
Conclusions: Rezvilutamide plus docetaxel followed by maintenance with rezvilutamide monotherapy demonstrated good tolerability and promising efficacy in chemotherapy-naive, abiraterone-refractory, mCRPC patients.
Background: Ascending thoracic aortic aneurysm (ATAA) is a fatal vascular disease characterized by immune dysregulation. However, the cellular composition, spatial localization, and functional diversity of immune cells in the ATAA microenvironment remain poorly understood.
Objective: To construct a high-resolution immune cell atlas of human ATAA and explore the immune-mediated vascular remodelling mechanisms associated with its progression.
Method: We conduct high-throughput single-cell RNA sequencing (scRNA-seq) of aortic tissues from eight ATAA patients and nine controls, including six from the GEO database. In the ATAA group, CD45+ cell subpopulations are isolated, and the scRNA-seq results are integrated with Visium high-definition spatial transcriptomics analysis to achieve near-single-cell resolution cell localization through deconvolution. Advanced cell segmentation algorithms are applied to generate a high-resolution immune cell atlas of human ATAA.
Results: A total of 187163 high-quality immune cells are identified, encompassing eight major immune cell types. Immune cells are significantly enriched in ATAA tissues compared with the controls. CellChat analysis reveals strong immune cell interactions in ATAA, which may contribute to its occurrence and progression.
Conclusion: This study presents the first high-resolution immune cell atlas of human ATAA, offering novel insights into its immune-mediated vascular remodelling mechanism.
Key points: What is currently known about this topic?ATAA is a vascular disease characterized by medial degeneration and chronic inflammation. Previous single-cell transcriptomic studies have revealed the cellular heterogeneity of the aortic wall and identified alterations in the populations of smooth muscle, fibroblasts and endothelial cells. However, the immune landscape of ATAA remains unclear. Recent single-cell and spatial analyses of aortic dissections and abdominal aortic aneurysms have revealed dynamic immune remodelling involving macrophage polarization, T-cell activation and cytokine-driven matrix degradation. Nevertheless, the spatial resolution of immune heterogeneity and cross-lineage signalling in human ATAA is poorly understood.What is the key research question?This study aimed to determine the cellular composition, spatial distribution and transcriptional reprogramming of immune cell populations in ATAA and to elucidate how the interactions among immune cells lead to inflammation and pathological remodelling of the aortic wall.
Background: Sepsis-induced intestinal injury is a severe complication associated with dysfunction affecting multiple organ systems and a significantly elevated risk of death. Intestinal barrier dysfunction plays a central role, but the underlying molecular pathways remain incompletely understood. The present study sought to explore how the Gzma/GEF-H1/RhoA signalling axis contributes to the disruption of the intestinal epithelial barrier in sepsis.
Methods: Transcriptomic data, clinical samples, and a murine caecal ligation and puncture (CLP) model was used to assess Gzma expression and its correlation with disease severity. We investigated how Gzma—released by activated immune cells—affects epithelial structure and function using in vitro co-culture assays. These experiments assessed key tight junction proteins (occludin, claudin-1, ZO-1, E-cadherin), transepithelial electrical resistance (TEER), and paracellular permeability. GEF-H1 knockout mice and the GEF-H1 activator plinabulin were employed to evaluate the physiological roles of GEF-H1. Mutagenesis revealed how Gzma activates GEF-H1. High-throughput screening identified a GEF-H1 modulator, and its efficacy was validated in septic mice. Gzma expression was significantly elevated during sepsis and correlated with disease severity. Gzma secretion from immune cells impaired the epithelial barrier by downregulating tight junction proteins, increasing permeability, and reducing TEER. Gzma activates GEF-H1 by dephosphorylating Ser886, triggering the RhoA/ROCK pathway and subsequent phosphorylation of MLC2, LIMK, and cofilin—driving cytoskeletal remodelling. GEF-H1 knockout mice showed reduced intestinal injury, higher survival rates, and intact barrier function; conversely, GEF-H1 activation worsened intestinal damage. High-throughput screening identified Epothilone A as a potent GEF-H1 modulator that restores intestinal barrier integrity and improves survival in murine sepsis by suppressing the GEF-H1/librariesRhoA pathway.
Conclusion: This research uncovers the Gzma/GEF-H1/RhoA signalling axis as a pivotal contributor to intestinal barrier dysfunction during sepsis. GEF-H1 represents a promising therapeutic target, and its inhibition by agents such as Epothilone A may offer a novel strategy for treating sepsis.
Key points:
Background: Kinesin family member 23 (KIF23) is recognised as an important tumour promoter involved in the pathogenesis of various cancers. However, its role and underlying molecular mechanisms in regulating cervical cancer (CC) growth and primary chemoresistance remain to be fully elucidated.
Methods: The expression and prognostic significance of KIF23 were initially assessed through bioinformatic analyses and subsequently validated in clinical specimens. To evaluate the effects of KIF23 on cell proliferation and cisplatin (DDP) sensitivity in CC cells, in vitro and in vivo experiments were conducted using CRISPR/Cas9 knockout, overexpression and mouse xenograft models. Co-immunoprecipitation, protein half-life assays and ubiquitination assays were employed to elucidate the interactions and regulatory mechanisms involving KIF23, myosin heavy chain 9 (MYH9), minichromosome maintenance protein 2 (MCM2) and proliferating cell nuclear antigen (PCNA), thereby revealing the molecular basis of KIF23-mediated CC progression and primary chemoresistance.
Results: KIF23 is highly expressed in CC tissues and is significantly correlated with poor prognosis and DDP resistance in patients. The knockout of KIF23 inhibited cell proliferation, induced G1-phase arrest and enhanced chemosensitivity to DDP. Mechanistically, the C-terminal domain of KIF23 was found to directly bind to the myosin tail domain of MYH9. This interaction stabilises MYH9 by recruiting deubiquitinase 7 (ubiquitin-specific protease 7 [USP7]), which removes K48-linked ubiquitin chains. The consequent upregulation of MYH9 promoted the recruitment of ubiquitin-specific protease 15 (USP15) to deubiquitinate MCM2, thereby preventing its degradation. Lysine 469 (K469) of MCM2 was identified as the key site for MYH9-induced deubiquitination. Furthermore, elevated MCM2 levels enhanced its binding to PCNA, thereby promoting CC cell proliferation.
Conclusions: These findings demonstrated that elevated KIF23 levels act as an unfavorable prognostic factor for CC by promoting cell proliferation and primary chemoresistance via the activation of the MYH9/MCM2/PCNA axis. Thus, KIF23 may represent a promising therapeutic target for improving clinical outcomes in CC.
Highlights:
Background: Current therapeutic outcomes for advanced colorectal cancer (CRC) remain suboptimal, and chemotherapy-based regimens continue to be the mainstay of treatment. Circular RNAs (circRNAs) can serve as templates for translating short peptides or proteins, and the resulting products actively regulate malignant tumour progression, making them attractive therapeutic targets.
Methods: We identified the novel protein PVT1-104aa translated from circPVT1, which is generated by back-splicing of the non-coding PVT1 gene. Its expression and clinical significance were examined in CRC clinical specimens and cell lines. Proliferation, metastasis, and tumour growth were assessed by CCK-8, colony formation, transwell, wound healing, and xenograft syngeneic tumour models. Mechanistic studies were performed by immunoprecipitation, ubiquitination assays, and protein half-life analysis. The relationship between PVT1-104aa, c-Myc, and PD-L1 was evaluated by promoter reporter assays, ChIP-qPCR, and immunohistochemistry. The therapeutic efficacy of combining PVT1-104aa inhibition with anti-PD-L1 therapy was tested in vivo.
Results: PVT1-104aa was significantly overexpressed in CRC and correlated with poor patient prognosis. Functionally, it drove tumour progression by promoting proliferation and metastasis. Mechanistically, PVT1-104aa enhanced c-Myc phosphorylation at Ser62, disrupted the c-Myc-FBW7 interaction, and thereby inhibited ubiquitin-mediated degradation of c-Myc, as shown by accelerated c-Myc turnover upon PVT1-104aa knockdown. In addition, PVT1-104aa regulated PD-L1 expression through c-Myc. Combining anti-PVT1-104aa with anti-PD-L1 therapy suppressed CRC growth and increased CD4+ and CD8+ T cell infiltration in xenograft syngeneic tumour models and CRC tissues.
Conclusions: Our results uncover a pathogenic role of the PVT1-originated molecular species PVT1-104aa and suggest that targeting this pathway represents a promising therapeutic strategy for CRC treatment.
Key points:
Background: Laryngotracheal stenosis (LTS) is a fibroproliferative disease of the upper airway characterised by dysregulated extracellular matrix deposition and fibroblast activation. AlkB Homologue 5 (ALKBH5) has emerged as a key regulator of disease pathogenesis by modulating mRNA stability, yet its role in LTS remains unclear.
Methods: We established a LTS rat model and observed mRNA m6A methylation and m6A demethylase ALKBH5 in stenotic tissues. Using single-cell RNA sequencing, in vivo ALKBH5 knockout models, and in vitro gain- and loss-of-function assays, we explored the role of ALKBH5 in fibroblast activation and fibrosis. The downstream target of ALKBH5 and its underlying molecular mechanism were identified through integrating RNA-seq and MeRIP-seq analyses, and further validated by RNA immunoprecipitation (RIP)-quantitative PCR (qPCR), dual-luciferase reporter assays, and in vitro gain- and loss-of-function experiments. In addition, the therapeutic potential of exogenous modulation of ALKBH5 target was evaluated in LTS models.
Results: ALKBH5 acted as a key pro-fibrotic regulator by enhancing the expression of COL1A1, COL3A1 and alpha-smooth muscle actin (α-SMA), increasing fibroblast contractility, and promoting airway fibrosis progression in LTS. RNA-seq and MeRIP-seq analyses identified Igfbp4 as a direct target of ALKBH5. RIP-qPCR and luciferase reporter assay confirmed ALKBH5 binding to the 3′-untranslated region of Igfbp4. Functional studies revealed that IGFBP4 inhibited β-catenin signalling and attenuated fibroblast activation. Overexpression of IGFBP4 partly reversed the profibrotic effects of ALKBH5, both in vitro and in vivo, significantly reducing collagen deposition and airway narrowing in LTS rats.
Conclusion: Our findings identify a novel ALKBH5–IGFBP4 regulatory axis that drives fibroblast activation and airway fibrosis in LTS. Targeting ALKBH5 or supplementing IGFBP4 may become novel therapeutic strategies for LTS.
Tumour metabolic modulation represents a promising adjuvant therapeutic strategy for cancers, including colorectal cancer (CRC). Dapagliflozin, a clinically approved sodium‒glucose cotransporter 2 (SLC5A2/SGLT2) inhibitor, has attracted considerable attention, yet its functional role in CRC remains unclear. Here, we investigated the oncogenic effect of SLC5A2 on the colorectal mucosal epithelium using transgenic rats and an azoxymethane/dextran sulphate sodium (AOM/DSS)-induced tumour model. Multiple immunofluorescence and tissue microarray analyses of clinical samples revealed an inverse correlation between SLC5A2 expression and natural killer (NK) cell infiltration, highlighting the therapeutic potential of dapagliflozin for CRC treatment. Mechanistically, gene expression profiling analysis and coculture experiments demonstrated that SLC5A2 impairs NKG2D-mediated NK cell cytotoxicity. Furthermore, perforated patch‒clamp and calcium imaging revealed that SLC5A2 modulates the membrane potential and calcium influx, enhancing MHC-I-associated MICA/B secretion via extracellular vesicle (EV) formation and thereby enabling CRC cells to evade NK cell surveillance. Our findings reveal a critical oncogenic role of SLC5A2 in CRC progression and suggest dapagliflozin as a novel therapeutic option, particularly for CRC patients with metabolic comorbidities.
Background: Cardiac macrophages (cMacs) have been implicated in myocardial repair following myocardial infarction (MI), yet their therapeutic potential in ischaemic cardiomyopathy (ICM) remains limited by an incomplete understanding of their molecular regulation. Cluster of Differentiation 163 (CD163) is highly expressed in these macrophages, yet its functional role in regulating post-MI cardiac repair remains unknown.
Methods: A cross-sectional clinical study was conducted to assess the association between circulating soluble CD163 concentration and heart failure due to ICM. To investigate the functional contribution of CD163 in ICM, wild-type (WT) and Cd163−/− mice were subjected to permanent ligation of the left anterior descending coronary artery. Single-cell RNA sequencing was employed to analyse transcriptional changes in cardiac immune cells. Recombinant osteopontin (OPN) and CD163 were administered to assess their therapeutic effect in Cd163−/− mice.
Results: Circulating soluble CD163 levels were markedly elevated in patients with ICM-induced heart failure compared with individuals without heart failure (median difference 34.5 ng/mL, IQR 13.6–54.6 ng/mL, p = .002) and showed a positive correlation with the extent of systolic dysfunction and left ventricular (LV) dilation. Cd163−/− mice displayed aggravated LV systolic dysfunction, reduced ejection fraction and fractional shortening, impaired myocardial strain and reduced relative wall thickness post-MI. Recombinant CD163 protein could reverse systolic dysfunction and LV dilation in Cd163−/− mice after MI. CD163 was predominantly expressed in CCR2− resident cMacs, and CD163 deficiency altered transcriptional programmes of macrophages without affecting their polarization status, with enrichment in cytokine signalling and extracellular matrix-related pathways. Spp1 (OPN) expression was significantly downregulated in Cd163−/− hearts under both sham and MI conditions. Administration of recombinant OPN improved systolic function, reduced ventricular dilation, decreased fibrotic scar size and restored the elastin-to-collagen ratio in Cd163−/− mice.
Conclusions: In cMacs, CD163 contributes to post-MI repair by upregulating OPN expression, which in turn helps maintain systolic function.
Key points:
Background: Vascular smooth muscle cell (VSMC) phenotype switching plays a significant role in the pathogenesis of atherosclerosis (AS). However, the subtypes of VSMC transdifferentiation and their impact on AS progression and atherosclerotic plaque instability remains unclear.
Methods: We reanalysed scRNA-seq datasets of GSE155513 and GSE253903 and performed single-sample gene set enrichment analysis (ssGSEA) in three transcriptome datasets from unstable plaques to determine the major subtypes contributing the most to plaque instability. Using high-dimensional weighted gene co-expression network analysis (hdWGCNA), we identified hub genes in macrophage (MP)-like smooth muscle cells (SMCs) of unstable plaques. We conducted cell communication analysis according to tensin1 (TNS1) gene levels in VSMCs. TNS1 expression was analysed in human AS plaques. Finally, an AS model was established in VSMC-specific Tns1 knockout ApoE−/− mice to validate the causative role of TNS1 on atherosclerotic lesions.
Results: MP-like SMC was identified as the key subtype for plaque instability. hdWGCNA analysis for MP-like SMC identified blue module as the key gene module involved in unstable plaques. Decreased TNS1 expression in VSMCs was positively correlated with the down-regulation of contractile VSMC marker genes, SRF and MYCOD genes, negatively correlated with the up-regulation of CD68 and KLF4 genes, and activated VCAM, PDGF, THBS and CXCL signalling pathways. TNS1 mRNA expression levels were lower in human atherosclerotic arteries than in healthy arteries, and even lower in unstable plaques than in early and stable plaques. TNS1 protein levels in VSMCs were lower in human atherosclerotic plaques than in healthy arteries, and even lower in advanced plaques than in early plaques. VSMC-specific Tns1 gene deficiency aggravated AS progression and enhanced plaque instability with increased MP-like SMC transdifferentiation.
Conclusion: The reduction of TNS1 gene in VSMCs might drive contractile VSMC transdifferentiation into MP-like SMC, the major subtype contributing to plaque instability. In vivo experimental results confirmed the role of Tns1 gene in contractile VSMC transdifferentiation into MP-like SMC and plaque instability.
Background: Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutant lung adenocarcinoma (LUAD) typically demonstrates limited response to neoadjuvant immunotherapy (NIT). Elucidating the immune determinants that differentiate responders from non-responders was critical for optimizing immunotherapy strategies. This study aimed to characterize the tumour microenvironment features of KRAS-mutant LUAD following neoadjuvant programmed death protein 1 (PD-1) inhibitor therapy by integrating clinical outcomes with single-cell RNA sequencing (scRNA-seq).
Methods: A total of 143 patients with resectable LUAD were consecutively enrolled in this study, including 106 cases in the KRAS-wildtype cohort and 37 cases in the KRAS-mutant cohort. We systematically compared the pathological response rates, survival outcomes and recurrence patterns between the two cohorts. We performed scRNA-seq on tumour specimens from 234 real-world patients with non-small cell lung cancer. From this cohort, 48 LUAD cases were identified and stratified by KRAS mutation status (13 KRAS-mutant and 35 KRAS-wildtype patients). Cellular compositions, transcriptional features and intercellular communication networks were analysed.
Results: Clinical analysis revealed that the KRAS-mutant group exhibited significantly poorer pathological responses (p = .032) and inferior long-term survival compared to the KRAS-wildtype group. We identified an immunosuppressive tumour necrosis factor receptor superfamily member 4 (TNFRSF4)-expressing regulatory T-cell (CD4T_Treg_TNFRSF4) subset enriched in non-responders, whereas responders showed increased frequencies of T helper 1 cells (Th1 cells) and a previously unrecognized exhausted-like B-cell state (Bex). Bex cells displayed impaired metabolic activity yet retained antigen presentation potential and showed extensive cellular interactions with Th1 cells, suggesting a supportive role in Th1-mediated antitumour immunity.
Conclusion: KRAS-mutant patients exhibited significantly poorer pathological responses, and KRAS-mutant status may independently predict survival outcomes after NIT in LUAD patients. Additionally, our study unveiled the cellular and molecular architecture underlying differential responses to NIT in KRAS-mutant LUAD, emphasizing the opposing roles of immunosuppressive Tregs and synergistic Bex–Th1 networks.
Highlights:
Background: Chronic psychological stress drives neuroimmune crosstalk and accelerates atherosclerosis progression. Physical exercise confers broad health benefits and is associated with reduced inflammation. However, the exercise-mediated factors and mechanisms that mitigate stress-induced vascular inflammation remain unclear.
Methods: Chronic restraint stress (CRS) and voluntary exercise models were established to investigate the role of exercise in neuroimmune crosstalk. RNA sequencing identified kinesin family member 4 (Kif4) as a key gene associated with the attenuation of stress-induced inflammatory responses in peripheral blood monocytes following exercise. Combined co-immunoprecipitation–mass spectrometry and membrane proteomics identified T cell-interacting activating receptors on myeloid cell 1 (TARM1) as the Kif4 cargo. The function of TARM1 was validated using an immobilized TARM1-Fc fusion protein. Brain-derived neurotrophic factor (BDNF), a key effector during exercise and stress, regulated the Kif4–TARM1 axis using recombinant BDNF (rBDNF) and the TrkB inhibitor ANA-12. Finally, exercise-mediated effects and mechanisms were examined in atherosclerotic CRS-exposed mouse models and in patients with coronary artery disease (CAD) experiencing high psychological stress.
Results: Physical exercise alleviated stress-induced neuroimmune crosstalk, reduced the proinflammatory CD11b+Ly6Chigh monocyte phenotype, and suppressed M1 macrophage polarization. Kif4 knockdown mitigated proinflammatory responses in peripheral blood monocytes and BMDMs in the CRS model mice. Mechanistically, kinesin Kif4 facilitates microtubule-dependent transport of TARM1 to the plasma membrane, thereby promoting macrophage inflammatory responses and enhancing monocyte‒endothelial cell adhesion. Conversely, neurogenic BDNF, regulated by exercise and stress, activated the TrkB receptor in monocytes/macrophages and inhibited the p-STAT3/Kif4/TARM1 signalling pathway. Furthermore, in both an atherosclerotic mouse model and patients with CAD, exercise mitigated stress-induced inflammation via the BDNF–Kif4–TARM1 axis.
Conclusions: Physical exercise alleviates stress-induced neuroimmune crosstalk through the BDNF–Kif4–TARM1 axis, revealing a novel neuroimmune-mediated brain–heart axis that supports exercise-based therapeutic strategies for psychogenic CAD.
Key Points:
Background: Autoimmune pancreatitis (AIP) is a chronic pancreatic inflammatory disease that is often difficult to differentiate from pancreatic cancer. Some AIP patients may even progress into pancreatic ductal adenocarcinoma (PDAC). We sought to delineate the peripheral immunological landscape of AIP, identify its differences from PDAC and find novel biomarkers for disease differentiation.
Methods: Single-cell RNA/BCR sequencing (scRNA/BCR-seq) was performed on peripheral blood mononuclear cells (PBMCs) from 10 type 1 AIP patients. Public PBMC sequencing data from 13 PDAC patients and 11 healthy volunteers were integrated in the analysis. Fourteen-colour flow cytometry was conducted in independent cohorts for validation.
Results: The analyses revealed a significantly higher proportion of IgG4high-switched memory B cells in patients with AIP than in PDAC. These cells, characterised by high CD23 expression, exhibited enhanced antigen-presenting capacity and might differentiate into pancreatic plasma cells in AIP. Compared with PDAC, AIP was characterised by an increased frequency of T follicular helper (Tfh) cells with a more pronounced exhaustion-like phenotype. Coculture experiments demonstrated that IgG4high-switched memory B cells can promote Tfh cell differentiation through major histocompatibility complex-mediated antigen presentation. TREM2-up-regulated intermediate monocytes were also increased in AIP and showed greater potential to differentiate into macrophages. The Boruta algorithm identified proportional changes in these subsets as useful for disease differentiation, and these findings were validated by multi-colour flow cytometry. A nomogram was established, with an AUC of .94 in the internal cohort and .88 in the external cohort. As for prognostic prediction, the reduction rate of Tfh cells after steroid therapy was associated with relapse risk.
Conclusion: By integrating scRNA/BCR-seq and flow cytometry, we identified three novel immune cell subsets in PBMCs of AIP patients and confirmed their diagnostic and prognostic value. A flow cytometry-derived nomogram based on these subsets provides a novel tool for differentiating patients with AIP from those with PDAC.