Background & AimsAutoimmune hepatitis (AIH) is a chronic inflammatory liver disease manifested with the aberrant activation of hepatic dendritic cells (HDCs) and the subsequent breakdown of immune homeostasis. As an important player, HDC maintains immunological balance between tolerance to self‐antigens versus destruction against pathogens in liver. However, the intracellular signalling networks that program HDC remain unclear. We have now found the role of canonical Wnt/β‐catenin signalling in HDCs.MethodsLiver sections from AIH patients and healthy subjects were stained for the markers of Wnt/β‐catenin signalling. Concanavalin A (ConA) and HDC/Hepa1‐6 vaccine‐induced AIH mouse models were examined for liver injury, inflammation and immune cell functions by serum biochemistry, histology, quantitative reverse transcription polymerase chain reaction (qRT‐PCR), enzyme‐linked immunosorbent assay (ELISA) and flow cytometry analysis. Wnt/β‐catenin signalling expression was measured using immunoblot and qRT‐PCR.ResultsCanonical Wnt/β‐catenin signalling in HDC is deficient in AIH patients and a mouse model, which coincides with the immunogenic function of HDCs. Furthermore, Wnt ligand engagement reactivates Wnt/β‐catenin signalling and recovers the immunoregulatory phenotype of HDCs, in turn alleviating the severity of AIH. Likewise, pharmacologic activation of Wnt/β‐catenin signalling attenuates AIH progression.ConclusionsWe report here that the constitutively active canonical Wnt/β‐catenin signalling confers HDCs tolerogenicity under steady‐state conditions. Deficiency of this pathway gives rise to T cell‐mediated immune response and incidence of AIH. It may act as a new pathogenesis and treatment target for AIH.

Motivation Single-cell RNA-sequencing (scRNA-seq) is widely used to reveal cellular heterogeneity, complex disease mechanisms, and cell differentiation processes. Due to high sparsity and complex gene expression patterns, scRNA-seq data presents a large number of dropout events, affecting downstream tasks such as cell clustering and pseudo-time analysis. Restoring the expression levels of genes is essential for reducing technical noise and facilitating downstream analysis. However, Existing scRNA-seq data imputation methods ignore the topological structure information of scRNA-seq data and cannot comprehensively utilize the relationships between cells. Results Here, we propose a single-cell Graph Contrastive Learning method for scRNA-seq data imputation, named scGCL, which integrates graph contrastive learning and Zero-inflated Negative Binomial (ZINB) distribution to estimate dropout values. scGCL summarizes global and local semantic information through contrastive learning and selects positive samples to enhance the representation of target nodes. To capture the global probability distribution, scGCL introduces an autoencoder based on the ZINB distribution, which reconstructs the scRNA-seq data based on the prior distribution. Through extensive experiments, we verify that scGCL outperforms existing state-of-the-art imputation methods in clustering performance and gene imputation on 14 scRNA-seq datasets. Further, we find that scGCL can enhance the expression patterns of specific genes in Alzheimer’s disease datasets. Availability https://github.com/zehaoxiong123/scGCL Supplementary information Supplementary data are available at Bioinformatics online.

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Background: Tumor-derived organoid, namely tumoroid, can realistically retain the clinicopathologic features of original tumors even after long-term in vitro expansion. Here we develop this production methodology derived from hepatocellular carcinoma primary samples and generate a platform to evaluate the tumoricidal efficacy of autologous adoptive cell transfer including tumor infiltrating lymphocytes and peripheral blood lymphocytes.Methods: Haematoxylin and eosin together with immunohistochemistry staining were employed to ascertain the morphologic and histological features of tumoroids and original tumors. Tumor killing ability of T cells was detected by lactate dehydrogenase assay and propidium iodide staining. In tumoroid xenograft mouse model, tumor volumes were measured and T cell functions were examined by flow cytometry technique.Results: Four tumoroids with characteristics of poor differentiation and mild fibrosis were successfully established from fourteen hepatocellular carcinoma samples. More robust antitumor potential and hyperfunctional phenotype of all four tumor infiltrating lymphocytes were observed compared to matched peripheral blood lymphocytes in coculture system. In tumoroid xenograft mouse models, however, only one patient-derived tumor infiltrating lymphocytes with the highest antitumor activity can bestow efficient tumor eradication.Conclusions: Hepatocellular carcinoma tumoroid-based models could represent invaluable resources for evaluating the tumoricidal efficacy of autologous adoptive cell transfer. Tumor infiltrating lymphocytes should be a promising and yet-to-be-developed regimen to treat hepatocellular carcinoma.

Background Deer antlers are the only known mammalian structure that undergoes full regeneration. In addition, it is peculiar because when growing, it contains vascularized cartilage. The differentiation of antler stem cells (ASCs) into chondrocytes while inducing endochondral extension of blood vessels is necessary to form antler vascularized cartilage. Therefore, antlers provide an unparalleled opportunity to investigate chondrogenesis, angiogenesis, and regenerative medicine. A study found that Galectin-1 (GAL-1), which can be used as a marker in some tumors, is highly expressed in ASCs. This intrigued us to investigate what role GAL-1 could play in antler regeneration. Methods We measured the expression level of GAL-1 in antler tissues and cells by immunohistochemistry, WB and QPCR. We constructed antlerogenic periosteal cells (APCs, one cell type of ASCs) with the GAL-1 gene knocked out (APCGAL-1−/−) using CRISPR-CAS9 gene editing system. The effect of GAL-1 on angiogenesis was determined by stimulating human umbilical vein endothelial cells (HUVECs) using APCGAL-1−/− conditioned medium or adding exogenous deer GAL-1 protein. The effect of APCGAL-1−/− on chondrogenic differentiation was evaluated compared with the APCs under micro-mass culture. The gene expression pattern of APCGAL-1−/− was analyzed by transcriptome sequencing. Results Immunohistochemistry revealed that GAL-1 was widely expressed in the antlerogenic periosteum (AP), pedicle periosteum (PP) and antler growth center. Western blot and qRT-PCR analysis using deer cell lines further supports this result. The proliferation, migration, and tube formation assays of human umbilical vein endothelial cells (HUVECs) showed that the proangiogenic activity of APCGAL-1−/− medium was significantly decreased (P < 0.05) compared with the APCs medium. The proangiogenic activity of deer GAL-1 protein was further confirmed by adding exogenous deer GAL-1 protein (P < 0.05). The chondrogenic differentiation ability of APCGAL-1−/− was impeded under micro-mass culture. The terms of GO and KEGG enrichment of the differentially expressed genes (DEGs) of APCGAL-1−/− showed that down-regulated expression of pathways associated with deer antler angiogenesis, osteogenesis and stem cell pluripotency, such as the PI3K-AKT signaling pathway, signaling pathways regulating pluripotency of stem cells and TGF-β signaling pathway. Conclusions Deer GAL-1, has strong angiogenic activity, is widely and highly expressed in deer antler. The APCs can induce angiogenesis by secreting GAL-1. The knockout of GAL-1 gene of APCs damaged its ability to induce angiogenesis and differentiate into chondrocytes. This ability is crucial to the formation of deer antler vascularized cartilage. Moreover, Deer antlers offer a unique model to explore explore how angiogenesis at high levels of GAL-1 expression can be elegantly regulated without becoming cancerous. Graphical Abstract