Cholangiocytes play a crucial role in bile formation. Cholangiocyte injury causes cholestasis, including primary biliary cholangitis (PBC). However, the etiology of PBC remains unclear despite being characterized as an autoimmune disease. Using single-cell RNA sequencing (scRNA-seq), fluorescence-activated-cell-sorting, multiplex immunofluorescence (IF) and RNAscope analyses, we identified unique DUOX2⁺ACE2⁺ small cholangiocytes in human and mouse livers. Their selective decrease in PBC patients was associated with the severity of disease. Moreover, proteomics, scRNA-seq, and qPCR analyses indicated that polymeric immunoglobulin receptor (pIgR) was highly expressed in DUOX2⁺ACE2⁺ cholangiocytes. Serum anti-pIgR autoantibody levels were significantly increased in PBC patients, regardless of positive and negative AMA-M2. Spatial transcriptomics and multiplex IF revealed that CD27⁺ memory B and plasma cells accumulated in the hepatic portal tracts of PBC patients. Collectively, DUOX2⁺ACE2⁺ small cholangiocytes are pathogenic targets in PBC, and preservation of DUOX2⁺ACE2⁺ cholangiocytes and targeting anti-pIgR autoantibodies may be valuable strategies for therapeutic interventions in PBC.

Objectives. Endothelial cell injury is a critical pathological change during the development of atherosclerosis. Here, we explored the effect of omentin-1 on free fatty acid- (FFA-) induced endothelial cell injury. Methods. An FFA-induced endothelial cell injury model was established to investigate the role of omentin-1 in this process. Cell proliferation was analyzed with the Cell Counting Kit assay and flow cytometry. Scratch and transwell assays were used to evaluate cell migration. Factors secreted by endothelial cells after injury were detected by western blotting, reverse-transcription quantitative polymerase chain reaction, and cellular fluorescence assay. Results. Omentin-1 rescued the FFA-induced impaired proliferation and migration capabilities of human umbilical vein endothelial cells (HUVECs). It decreased the number of THP-1 cells attached to HUVECs in response to injury and inhibited the FFA-induced proinflammatory state of HUVECs. Conclusion. Omentin-1 could partly ameliorate FFA-induced endothelial cell injury.

Nasopharyngeal carcinoma (NPC) is an epithelial carcinoma originating from the nasopharyngeal mucosal tissue and is highly prevalent in southeast Asia. Galectin‑3 (gal‑3) serves crucial roles in many cancers but its role in NPC remains to be elucidated. The aim of the present study was to investigate the role of gal‑3 in NPC. Immunohistochemistry and ELISA were used to determine the expression level of gal‑3 in patients with NPC or chronic rhinitis (CR). Gal‑3 short hairpin (sh)RNA was established to knockdown gal‑3 in 5‑8F and 6‑10B cells, allowing for the evaluation of the roles of gal‑3 in proliferation, migration and apoptosis in NPC cell lines. Immunohistochemistry staining of IL‑6 and IL‑8 was applied to access the inflammatory state of tumor tissues, and the correlation between the inflammatory state and gal‑3 was analyzed. The results demonstrated that gal‑3 was upregulated in patients with NPC compared with patients with CR. Knockdown of gal‑3 inhibited proliferation and migration in 5‑8F and 6‑10B cells, as well as promoted apoptosis in these cells. The expression levels of MMP‑9 and IL‑8 were also decreased in 5‑8F and 6‑10B cells after transfection with gal‑3 shRNA. A positive correlation was identified between the expression level of gal‑3 and the inflammatory state of NPC. The phosphorylation levels of ERK1/2 and Akt were downregulated after knockdown of gal‑3 in 5‑8F and 6‑10B cells. In conclusion, the expression level of gal‑3 was upregulated in patients with NPC and was positively correlated with the inflammatory state of NPC. The results suggested that gal‑3 promoted the proliferation and migration of 5‑8F and 6‑10B cells, while inhibiting the apoptosis of these cells. Moreover, activation of ERK1/2 and Akt may be the underlying mechanism of the effects of gal‑3 on NPC.

Endothelial progenitor cells (EPCs) are a group of circulating cells with important functions in vascular repair and treatment of cardiovascular diseases. However, in patients with atrial fibrillation (AF), the number and function of EPCs reportedly are decreased. TGF-β is highly expressed in AF patients. In this study, we examined the effect of TGF-β1 on EPCs and the therapeutic outcome of metformin treatment on TGF-β1-induced EPCs. EPCs were induced with TGF-β1 at different concentrations (5 ng/ml, 10 ng/ml, and 20 ng/ml) for 48 h followed by western blot, qPCR, and immunofluorescence analyses to investigate changes in the levels of the fibrosis-related proteins, α-SMA, Col I, Col III, CTGF, and MMP-1. Live-dead cell staining was used to evaluate cell apoptosis. Compared with the control, TGF-β1 treatment significantly (p<0.05) enhanced the levels of α-SMA, Col I, Col III, CTGF, and MMP-1 in a dose-dependent manner. The most effective concentration of TGF-β1 (20 ng/ml) was then used to induce fibrosis biomarker expression in EPCs, followed by treatment with metformin at different concentrations (0.5, 1, and 2 mmol/l). Metformin treatment suppressed TGF-β-induced expression of all above factors, with the effect at 2 mmol/l being significant (p<0.05). Live-dead cell staining showed no difference among the control, TGF-β1-treated, and metformin-treated groups. In conclusion, our study showed that TGF-β1 induces the expression of fibrosis biomarkers in EPCs, which is attenuated by treatment with metformin. Thus, metformin may have therapeutic potential for improving EPC function in cardiovascular diseases.

Diabetes‐related macrovascular and microvascular complications lead to poor prognosis. Insulin receptor substrate p53 (IRSp53) is known to act as a substrate for the insulin receptor tyrosine kinase, but its role in endothelial dysfunction remains unclear. Human umbilical vein endothelial cells (HUVECs) treated with D‐glucose at different concentrations and a streptozocin‐induced rat diabetes mellitus (DM) model were used to investigate the effects of hyperglycemia on the expression levels of IRSp53 and galectin‐3 (gal‐3) and the inflammatory state and mobility of HUVECs. Thereafter, IRSp53‐overexpressing HUVECs and IRSp53‐knockdown HUVECs were established using IRSp53‐overexpressing lentivirus or IRSp53‐siRNA to explore the role of IRSp53 in the HUVEC inflammatory state and HUVEC mobility. D‐glucose at high concentration (HG) and hyperglycemia were found to induce downregulation of IRSp53 and upregulation of gal‐3 in vitro and in vivo. Treatment with HG resulted in activation of NF‐κB in HUVECs and impaired HUVEC mobility. Insulin restored HG‐induced changes in the expression levels of IRSp53 and gal‐3 in HUVECs and protected the cells from NF‐κB activation and impaired mobility. Overexpression of IRSp53 inhibited the activation of NF‐κB in HUVECs and strengthened HUVEC migration. Knockdown of IRSp53 facilitated the activation of NF‐κB in HUVECs and decreased HUVEC migration. However, neither overexpression nor knockdown of IRSp53 altered the effects of insulin on HG‐induced detrimental changes in HUVECs. HG and hyperglycemia resulted in downregulation of IRSp53 in vitro and in vivo. IRSp53 is concluded to inhibit the activation of NF‐κB in HUVECs and to strengthen HUVEC migration.

Organic anion-transporting polypeptides (OATPs) play a crucial role in the transport of bile acids and bilirubin. In our previous study, interleukin 6 (IL-6) reduced OATP1B3 levels in cholestatic disease. However, it remains unclear whether IL-6 inhibits OATP1B1 expression in cholestatic diseases. This study aimed to investigate whether IL-6 can inhibit OATP1B1 expression and explore the underlying mechanisms.