Abstract Background Pulmonary endarterectomy (PEA) remains one of potentially curative options for chronic thromboembolic pulmonary hypertension (CTEPH). The operation can remove proximal thromboembolic materials and their secondary branches. However, the cellular landscape and pathological features across different anatomical regions remain limited understood. Methods Ten patients with CTEPH undergoing PEA surgery and six reference distal pulmonary arteries were conducted single‐cell transcriptomics to profile the cellular composition of the main and its bifurcate portion. Results Pronounced muscularised and fibrotic thrombi organisation were presented in the main portion, and the proportion of mononuclear phagocytes was significantly increased. Inflammatory response and pro‐inflammatory activity were attributed to CD8+ effector T cells and nature killer cells subsets and a M1‐like (high IL1B and TNF, minimal IL6) phenotypic macrophage subcluster. The colander‐like lesions were dominant in the bifurcate portion, and the percentage of plasma cells was markedly increased. Immune dysregulation was induced from CD4 naïve T cells, and a downregulation of M2‐like macrophage infiltration into the vascular wall. The expression of plasminogen activator, urokinase receptor, urokinase receptor (PLAUR; plasminogen activator) were observed in M2‐like (high MRC1 and CD163, virtually no IL1B or TNF) macrophage in bifurcate portion. Notably, one of smooth muscle cells (SMCs) subclusters in the bifurcate portion gained more significantly myofibroblast markers than those in the main portion, and other subclusters remained the function of SMCs. Conclusions The regions with colander‐like lesions changes had more obviously T cell and macrophages driving immune‐inflammatory response and SMCs differentiation, suggesting that combining therapeutic interventions after surgical removal of accessible thrombus may be beneficial. Key points This study reveals the comprehensive cellular composition in main/lobar and bifurcate pulmonary endarterectomy (PEA) specimens at the single‐cell level. The bifurcate regions with colander had more obviously T cell and macrophages driving immune‐inflammatory response and smooth muscle cells (SMCs) differentiation, however, the remodelling of distal or micro‐vessels still remained.
Abstract Background Spatiotemporal transcriptomics (STT) integrates spatially resolved gene expression with temporal information derived from staged samples, paired treatment specimens, or computational inference, providing a framework for reconstructing tissue‐level dynamics. In the tumour microenvironment (TME), STT extends static molecular and cellular maps by revealing how cellular neighbourhoods and functional niches are reorganised during tumour evolution. Main text This review examines how STT characterises TME remodelling during malignant transformation, invasion, metastasis, ageing, and treatment response. We discuss strategies for resolving temporal dynamics, including stage‐stratified sampling, paired or serial specimens, pseudotime and trajectory inference, and complementary intravital imaging. We further consider how spatiotemporal analyses can connect changes in cellular states, spatial organisation, and intercellular interactions with clinically relevant tumour phenotypes. Conclusion By linking the spatial organisation of the TME with stage‐ and treatment‐associated molecular changes, STT may improve the prioritisation of candidate targets, treatment stratification, and the development of precision oncology strategies.
Abstract Background Mitochondrial transplantation is built on a simple idea: failing cells might be rescued by healthy mitochondria. The approach has entered early clinical testing, and encapsulation and cell‐type targeting have improved uptake in selected systems. Better delivery, however, does not explain the therapy. Main body Internalised donor mitochondria encounter an established network, quality‐control machinery and sensors for mitochondrial material. Donor material may remain in the endolysosomal system or reach the cytosol. Cytosolic fates include network integration, clearance and a candidate functional contribution without fusion. Intracellular processing may also generate bioactive cargo. These fates imply different mechanisms and evidence requirements. This Review examines how recipient cells shape the contribution of internalised mitochondria, while recognising extracellular routes to benefit. We distinguish direct transplantation evidence from mechanistic support drawn from endogenous mitochondrial biology and natural intercellular transfer. The required donor fate and duration depend on the therapeutic task. Transient rescue may rely on short‐term donor function or productive processing in specific models; sustained support may depend on continued donor function, recipient adaptation or redosing. Durable mitochondrial DNA (mtDNA) correction requires donor‐mtDNA retention and replication. Conclusions Linking these tasks to product design, safety assessment and clinical endpoints shifts the question from how many mitochondria enter cells to what they accomplish after arrival. Key points Recipient‐cell handling shapes what transplanted mitochondria do after uptake. Uptake, structural integration and donor mitochondrial DNA retention require distinct evidence. Transient rescue, sustained support and durable mitochondrial DNA correction impose different requirements. Therapeutic goals should guide donor selection, product testing and clinical endpoints.
Abstract Background Immune checkpoint inhibitor–associated myocarditis (ICIAM) is one of the immune–related adverse events (irAEs) with low incidence but extremely high mortality. High–dose glucocorticoid pulse therapy remains the recommended initial treatment for patients with ICIAM. However, an inadequate response to corticosteroid therapy is observed in some patients, who are subsequently classified as having steroid‐resistant immune checkpoint inhibitor‐associated myocarditis (srICIAM). Early combination of second‐line immunosuppression may represent an effective therapeutic strategy. However, Biomarkers capable of identifying such patients before treatment are currently lacking. We therefore sought to characterize circulating inflammatory proteins associated with corticosteroid responsiveness and to derive a preliminary serum‐based prediction model for steroid‐resistant ICIAM (srICIAM). Methods Serum specimens obtained from patients with ICIAM at baseline and after methylprednisolone treatment were analyzed to quantify circulating immune‐related proteins using an antibody‐based proteomic assay. We developed a preliminary model for the early identification of patients at risk of srICIAM using proteins selected by three complementary machine–learning algorithms and evaluated its discriminatory performance in an internal hold‐out cohort. Results Pretreatment serum samples from 47 patients with ICIAM were used to establish a protein–based prediction model, with 33 patients assigned to model development and 14 to internal validation. Patients with a high srICIAM predictive score (≥.5625) based on CXCL9, TRANCE and MMP1 were more likely to show an inadequate early response to corticosteroid therapy and may warrant closer clinical monitoring and further evaluation. The analysis also revealed that several serum immune proteins decreased in patients with ICIAM after methylprednisolone therapy. Serum CXCL9 levels were positively correlated with lactate dehydrogenase (LDH) and cardiac troponin T (cTnT). Conclusion Serum immune proteins were dynamically altered in patients with ICIAM after methylprednisolone therapy. The preliminary score may enable earlier recognition of patients at risk of an inadequate corticosteroid response.
RATIONALE:Circular RNAs (circRNAs) are stable, tissue- and developmental-stage-specific regulators of gene expression and candidate disease biomarkers. Their expression profile in abnormal lung development in congenital diaphragmatic hernia (CDH) is unknown. OBJECTIVE:To evaluate circRNA expression profile in CDH-associated abnormal lung development. METHODS:We profiled circRNAs in rat CDH and control lungs at embryonic day (E)15 and E21 by microarray. We validated identified circRNAs using back‒splice junction amplicon sequencing, RT-qPCR and in situ hybridisation. We modified a circRNA function prediction tool to predict circRNA::micro(mi)RNA::messenger(m)RNA interactions and compared these with Oxford Nanopore RNA sequencing and existing human CDH datasets. MEASUREMENTS AND MAIN RESULTS:Microarrays revealed a unique circRNA biosignature during CDH lung development. CircAnp32e was expressed in a sex-specific and spatiotemporal expression pattern in the epithelium at E15. The predicted mature sequence of circAnp32e overlapped 90% with its human orthologue. circRNA::miRNA::mRNA interaction networks at E15 and E21 revealed enrichment in inflammation/infection, smooth muscle cell function, cell proliferation/cell cycle regulation and response to hypoxia pathways. Parental genes of differentially expressed circRNAs at E15 enriched pathways linked to cell proliferation/cell cycle/cancer, while at end-gestation, inflammation and cardiovascular processes were also overrepresented. Rat and human CDH lungs showed overlapping pathways with additional enrichment for RNA processing and protein binding/modification in humans. In a human bronchial epithelial (BEAS-2B) nitrofen-injury model, ANP32E and circANP32E were downregulated, and the predicted let-7 target was significantly dysregulated. CONCLUSION:A unique circRNA signature during abnormal lung development in CDH may mediate inflammatory responses, smooth muscle cell function and cell proliferation regulation via miRNA sponging. Overlap of downstream pathways in rat and human CDH suggests conserved functions across species. This circRNA biosignature defines strong candidate biomarkers for CDH and a basis for future prospective prenatal investigation.
