Kupffer Cells Promote the Differentiation of Adult Liver Hematopoietic Stem and Progenitor Cells into Lymphocytes via ICAM-1 and LFA-1 Interaction

A dataset of single-cell transcriptomic atlas of Bama pig and potential marker genes across seven tissues

The use of single-cell sequencing technology for single-cell transcriptomics studies in pigs is expanding progressively. However, the comprehensive classification of cell types across different anatomical tissues and organs of pig in multiple datasets remains relatively limited. This study employs single-cell and single-nucleus sequencing technologies in Bama pig to identify unique marker genes and their corresponding transcriptomic profiles across diverse cell types in various anatomical tissues and organs, including subcutaneous fat, visceral fat, psoas major muscle, liver, spleen, lung, and kidney. Through detailed data analyses, we observed widespread cellular diversity across various anatomical tissues and organs of Bama pig. This work contributes a comprehensive dataset that supports physiological studies and aids in the identification and prediction of potential marker genes through single-cell transcriptomics of these tissues. The methodologies and data employed in this study are designed to improve the accuracy of cell type identification and ensure consistent cell type allocation.

Protective Roles of Apigenin Against Cardiometabolic Diseases: A Systematic Review

Apigenin is a flavonoid with antioxidant, anti-inflammatory, and anti-apoptotic activity. In this study, the potential effects of apigenin on cardiometabolic diseases were investigated in vivo and in vitro. Potential signaling networks in different cell types induced by apigenin were identified, suggesting that the molecular mechanisms of apigenin in cardiometabolic diseases vary with cell types. Additionally, the mechanisms of apigenin-induced biological response in different cardiometabolic diseases were analyzed, including obesity, diabetes, hypertension and cardiovascular diseases. This review provides novel insights into the potential role of apigenin in cardiometabolic diseases.

Murine CXCR3+CXCR6+γδT Cells Reside in the Liver and Provide Protection Against HBV Infection

Gamma delta (γδ) T cells play a key role in the innate immune response and serve as the first line of defense against infection and tumors. These cells are defined as tissue-resident lymphocytes in skin, lung, and intestinal mucosa. They are also relatively abundant in the liver; however, little is known about the residency of hepatic γδT cells. By comparing the phenotype of murine γδT cells in liver, spleen, thymus, and small intestine, a CXCR3⁺CXCR6⁺ γδT-cell subset with tissue-resident characteristics was found in liver tissue from embryos through adults. Liver sinusoidal endothelial cells mediated retention of CXCR3⁺CXCR6⁺ γδT cells through the interactions between CXCR3 and CXCR6 and their chemokines. During acute HBV infection, CXCR3⁺CXCR6⁺ γδT cells produced high levels of IFN-γ and adoptive transfer of CXCR3⁺CXCR6⁺ γδT cells into acute HBV-infected TCRδ^−/− mice leading to lower HBsAg and HBeAg expression. It is suggested that liver resident CXCR3⁺CXCR6⁺ γδT cells play a protective role during acute HBV infection. Strategies aimed at expanding and activating liver resident CXCR3⁺CXCR6⁺ γδT cells both in vivo or in vitro have great prospects for use in immunotherapy that specifically targets acute HBV infection.

Functional kupffer cells migrate to the liver from the intraperitoneal cavity

We established a method of KC transplantation by intraperitoneal (i.p.) injection using EGFP-expressing cells (EGFP-KCs) and normal KCs. The novel method is easier and less invasive than conventional methods so that it is not only technically advantageous but also ethically preferable for experiments using animals. We demonstrated that KCs migrated to the liver following i.p. Injection. Engraftment in the liver was not observed for peritoneal macrophages (pMPs). This suggests that KCs migrate to the liver via a sorting mechanism. KC injection decreased the KC number at 24 h and then recovered the KCs at 10 days to a normal level. Additionally, recovery to the normal level by KC injection was observed in mice with KC depletion induced by GdCl3. These results suggest that a regulatory mechanism exists for controlling the number of KCs.

Bioinformatic Analysis of Crosstalk Between circRNA, miRNA, and Target Gene Network in NAFLD

Background: The majority of chronic liver disease is caused by non-alcoholic fatty liver disease (NAFLD), which is one of the highly prevalent diseases worldwide. The current studies have found that non-coding RNA (ncRNA) plays an important role in the NAFLD, but few studies on circRNA. In this study, genes, microRNA (miRNA), and circular RNA (circRNA) associated with NAFLD were found by bioinformatic methods, bringing a novel perspective for the prevention and treatment of NAFLD.

Methods: Expression data of GSE63067 was acquired from Gene Expression Omnibus (GEO) database. The liver samples were collected from the people diagnosed with NAFLD or not. Differentially expressed genes (DEGs) were obtained from the steatosis vs. the control group and non-alcoholic steatohepatitis (NASH) vs. the control group using the GEO2R online tool. The overlapping genes remained for further functional enrichment analysis and protein-protein interaction network analysis. MiRNAs and circRNAs targeting these overlapping DEGs were predicted from the databases. Finally, the GSE134146 dataset was used to verify the expression of circRNA.

Results: In summary, 228 upregulated and 63 downregulated differential genes were selected. The top 10 biological processes and relative signaling pathways of the upregulated differential genes were obtained. Also, ten hub genes were performed in the Protein-protein interaction (PPI) network. One hundred thirty-nine miRNAs and 902 circRNAs were forecast for the differential genes by the database. Ultimately, the crosstalk between hsa_circ_0000313, miR-6512-3p, and PEG10 was constructed.

Conclusion: The crosstalk of hsa_circ_0000313-hsa-miR-6512-3p-PEG10 and some related non-coding RNAs may take part in NAFLD’s pathogenesis, which could be the potential biomarkers of NAFLD in the future.

Single-cell analysis reveals the origins and intrahepatic development of liver-resident IFN-γ-producing γδ T cells

γδ T cells are heterogeneous lymphocytes located in various tissues. However, a systematic and comprehensive understanding of the origins of γδ T cell heterogeneity and the extrathymic developmental pathway associated with liver γδ T cells remain largely unsolved. In this study, we performed single-cell RNA sequencing (scRNA-seq) to comprehensively catalog the heterogeneity of γδ T cells derived from murine liver and thymus samples. We revealed the developmental trajectory of γδ T cells and found that the liver contains γδ T cell precursors (pre-γδ T cells). The developmental potential of hepatic γδ T precursor cells was confirmed through in vitro coculture experiments and in vivo adoptive transfer experiments. The adoptive transfer of hematopoietic progenitor Lin^-Sca-1⁺Mac-1⁺ (LSM) cells from fetal or adult liver samples to sublethally irradiated recipients resulted in the differentiation of liver LSM cells into pre-γδ T cells and interferon-gamma⁺ (IFN-γ⁺) but not interleukin-17a⁺ (IL-17a⁺) γδ T cells in the liver. Importantly, thymectomized mouse models showed that IFN-γ-producing γδ T cells could originate from liver LSM cells in a thymus-independent manner. These results suggested that liver hematopoietic progenitor LSM cells were able to differentiate into pre-γδ T cells and functionally mature γδ T cells, which implied that these cells are involved in a distinct developmental pathway independent of thymus-derived γδ T cells.

The cellular pathways of liver fibrosis in non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is considered the advanced stage of non-alcoholic fatty liver disease (NAFLD). It is characterized by liver steatosis, inflammation and different degrees of fibrosis. Although the exact mechanisms by which fatty liver progresses to NASH are still not well understood, innate and adaptive immune responses seem to be essential key regulators in the establishment, progression, and chronicity of these disease. Diet-induced lipid overload of parenchymal and non-parenchymal liver cells is considered the first step for the development of fatty liver with the consequent organelle dysfunction, cellular stress and liver injury. These will generate the production of pro-inflammatory cytokines, chemokines and damage-associated molecular patterns (DAMPs) that will upregulate the activation of Kupffer cells (KCs) and monocyte-derived macrophages (MMs) favoring the polarization of the tolerogenic environment of the liver to an immunogenic phenotype with the resulting transdifferentiation of hepatic stellate cells (HSCs) into myofibroblasts developing fibrosis. In the long run, dendritic cells (DCs) will activate CD4+ T cells polarizing into the pro-inflammatory lymphocytes Th1 and Th17 worsening the liver damage and inflammation. Therefore, the objective of this review is to discuss in a systematic way the mechanisms known so far of the immune and non-proper immune liver cells in the development and progression of NASH.

β2 Integrins-Multi-Functional Leukocyte Receptors in Health and Disease

β2 integrins are heterodimeric surface receptors composed of a variable α (CD11a-CD11d) and a constant β (CD18) subunit and are specifically expressed by leukocytes. The α subunit defines the individual functional properties of the corresponding β2 integrin, but all β2 integrins show functional overlap. They mediate adhesion to other cells and to components of the extracellular matrix (ECM), orchestrate uptake of extracellular material like complement-opsonized pathogens, control cytoskeletal organization, and modulate cell signaling. This review aims to delineate the tremendous role of β2 integrins for immune functions as exemplified by the phenotype of LAD-I (leukocyte adhesion deficiency 1) patients that suffer from strong recurrent infections. These immune defects have been largely attributed to impaired migratory and phagocytic properties of polymorphonuclear granulocytes. The molecular base for this inherited disease is a functional impairment of β2 integrins due to mutations within the CD18 gene. LAD-I patients are also predisposed for autoimmune diseases. In agreement, polymorphisms within the CD11b gene have been associated with autoimmunity. Consequently, β2 integrins have received growing interest as targets in the treatment of autoimmune diseases. Moreover, β2 integrin activity on leukocytes has been implicated in tumor development.