HepG2.2.15-derived exosomes facilitate the activation and fibrosis of hepatic stellate cells.

BACKGROUND: The role of exosomes derived from HepG2.2.15 cells, which express hepatitis B virus (HBV)-related proteins, in triggering the activation of LX2 liver stellate cells and promoting liver fibrosis and cell proliferation remains elusive. The focus was on comprehending the relationship and influence of differentially expressed microRNAs (DE-miRNAs) within these exosomes. AIM: To elucidate the effect of exosomes derived from HepG2.2.15 cells on the activation of hepatic stellate cell (HSC) LX2 and the progression of liver fibrosis. METHODS: Exosomes from HepG2.2.15 cells, which express HBV-related proteins, were isolated from parental HepG2 and WRL68 cells. Western blotting was used to confirm the presence of the exosomal marker protein CD9. The activation of HSCs was assessed using oil red staining, whereas DiI staining facilitated the observation of exosomal uptake by LX2 cells. Additionally, we evaluated LX2 cell proliferation and fibrosis marker expression using 5-ethynyl-2'-deoxyuracil staining and western blotting, respectively. DE-miRNAs were analyzed using DESeq2. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to annotate the target genes of DE-miRNAs. RESULTS: Exosomes from HepG2.2.15 cells were found to induced activation and enhanced proliferation and fibrosis in LX2 cells. A total of 27 miRNAs were differentially expressed in exosomes from HepG2.2.15 cells. GO analysis indicated that these DE-miRNA target genes were associated with cell differentiation, intracellular signal transduction, negative regulation of apoptosis, extracellular exosomes, and RNA binding. KEGG pathway analysis highlighted ubiquitin-mediated proteolysis, the MAPK signaling pathway, viral carcinogenesis, and the toll-like receptor signaling pathway, among others, as enriched in these targets. CONCLUSION: These findings suggest that exosomes from HepG2.2.15 cells play a substantial role in the activation, proliferation, and fibrosis of LX2 cells and that DE-miRNAs within these exosomes contribute to the underlying mechanisms.

Study of Recellularized Human Acellular Arterial Matrix Repairs Porcine Biliary Segmental Defects.

Background: With the popularity of laparoscopic cholecystectomy, common bile duct injury has been reported more frequently. There is no perfect method for repairing porcine biliary segmental defects. Methods: After the decellularization of human arterial blood vessels, the cells were cultured with GFP+ (carry green fluorescent protein) porcine bile duct epithelial cells. The growth and proliferation of porcine bile duct epithelial cells on the human acellular arterial matrix (HAAM) were observed by hematoxylin-eosin (HE) staining, electron microscopy, and immunofluorescence. Then, the recellularized human acellular arterial matrix (RHAAM) was used to repair biliary segmental defects in the pig. The feasibility of it was detected by magnetic resonance cholangiopancreatography, liver function and blood routine changes, HE staining, immunofluorescence, real-time quantitative PCR (RT-qPCR), and western blot. Results: After 4 weeks (w) of co-culture of HAAM and GFP+ porcine bile duct epithelial cells, GFP+ porcine bile duct epithelial cells grew stably, proliferated, and fused on HAAM. Bile was successfully drained into the duodenum without bile leakage or biliary obstruction. Immunofluorescence detection showed that GFP-positive bile duct cells could still be detected after GFP-containing bile duct cells were implanted into the acellular arterial matrix for 8 w. The implanted bile duct cells can successfully resist bile invasion and protect the acellular arterial matrix until the newborn bile duct is formed. Conclusion: The RHAAM can be used to repair biliary segmental defects in pigs, which provides a new idea for the clinical treatment of common bile duct injury.

Prolonged warm ischemia aggravates hepatic mitochondria damage and apoptosis in DCD liver by regulating Ca2+/CaM/CaMKII signaling pathway.

This study was conducted to investigate the effect of warm ischemia duration on hepatocyte mitochondrial damage after liver transplantation, and confirm the role of CaMKIIγ in this process. Rat donation after cardiac death (DCD) liver transplantation model was established by exposing donor liver to 0 (W0 group), 15 (W15 group), and 30 (W30 group) min warm ischemia. Some rats in W15 group were transfected with CaMKIIγ and CaMKIIγ-shRNA lentivirus. On day 1, 3, and 7 post-transplantation, a series of experiments, including HE staining, TEM observation, ALT and AST measurement, flow cytometry analysis, qRT-PCR, and Western blotting were performed to evaluate the extent of hepatic and mitochondria damage. Within 7 days post-transplantation, prolonged ischemia led to an obvious deterioration of hepatic and mitochondria damage, presenting with a marked increase of apoptotic hepatocytes, ALT and AST levels, cells with low MMP, and AIF and Cyt C expression. CaMKIIγ overexpression caused the significant ultrastructural damage of hepatic cells, increase of cells with low MMP, enhancement of AIF and Cyt C expression, and augmented Ca2+/CaM/CaMKIIγ, while blocking CaMKIIγ showed an opposite result. In conclusion, ischemia duration is proportional to the extent of hepatic mitochondria damage, and CaMKIIγ plays a negative regulatory role in this process by regulating the Ca2+/CaM/CaMKII signaling pathway.

Mechanism of immune hyporesponsiveness induced by recipient- derived immature dendritic cells in liver transplantation rat.

OBJECTIVE: To investigate the mechanism of immune hyporesponsiveness induced by donor-antigen- unloaded recipient-derived immature dendritic cell (imDC) of liver grafts in rats. METHODS: Forty Sprague-Dawley rats (donor) and forty male Wistar rats (recipient) were randomly divided into 4 groups: control, cyclosporine A (CsA), mature DC (mDC), and imDC groups respectively, with 10 donor rats and 10 recipient rats in each group. Recipient rats in CsA group were treated with 10 mg•kg⁻¹â€¢d⁻¹ CsA starting day 2 after the transplantation. Recipients in the mDC or imDC groups were given Wistar rat derived mDCs (1 × 106/rat) or imDCs (1 × 106/rat) via dorsal vein of the penis respectively 1 day before the transplantation. In each group, 5 recipients were kept for determination of survival time and the other 5 rats were executed at day 10 after transplantation. Blood samples were collected for the measurement of serum alanine aminotransferase (ALT), total bilirubin (TBIL), interleukin 2 (IL-2), interferon gamma (IFN-γ), IL-4, and IL-10 levels. Liver tissue was harvested for HE staining and acute rejection evaluation. Expression levels of Fas-L/Fas in the grafts were detected by immunohistochemical staining; and Western blot was used to detect the expression level of Scurfin. RESULTS: The survival time of CsA and imDC groups was significantly longer than that of control and mDC groups (all P < 0.05). The levels of serum ALT and TBIL in the control group (2072.20 ± 217.93 IU/L and 147.42 ± 22.02 µmol/L) and mDC group (2117.00 ± 285.13 IU/L and 141.58 ± 20.82 µmol/L) were significantly higher than those in the CsA group (59.68 ± 13.48 IU/L and 15.40 ± 2.13 µmol/L) or imDC group (50.80 ± 9.63 IU/L and 14.44 ± 3.49 µmol/L) (all P < 0.05). In the CsA and imDC groups, the levels of IL-2 (22.52 ± 3.75 pg/mL and 22.12 ± 3.90 pg/mL) and IFN-γ (309.20 ± 25.19 pg/mL and 321.00 ± 21.64 pg/mL) were significantly lower, but the levels of IL-4 (297.60 ± 25.07 pg/mL and 277.00 ± 22.47 pg/mL) and IL-10 (1226.00 ± 140.49 pg/mL and 1423.00 ± 106.39 pg/mL) were higher than those of the control (IL-2: 147.78 ± 12.80 pg/mL, IFN-γ: 1758.60 ± 106.22 pg/mL, IL-4: 17.40 ± 4.77 pg/mL, IL-10: 81.00 ± 9.47 pg/mL) and mDC groups (IL-2: 142.34 ± 9.29 pg/mL, IFN-γ: 1835.00 ± 82.63 pg/mL, IL-4: 15.60 ± 3.96 pg/mL, IL-10: 68.80 ± 11.23 pg/mL) (all P < 0.01). The expression level of Scurfin protein on CD4+ CD25+ T cells of the imDC group (1.34 ± 0.29) was significantly higher than that in the control (0.72 ± 0.13), CsA (0.37 ± 0.11), and mDC groups (0.78 ± 0.17) (all P < 0.05). CONCLUSION: Donor-antigen-unloaded recipient-derived imDC is an effective treatment in inducing immune hyporesponsiveness through induction of T cell apoptosis, shift in Thl/Th2 balance, and proliferation of regulatory T cell.

[A causal analysis of intra-abdominal hemorrhage after reduced-size liver transplantation in rats].

OBJECTIVE: To analyze the cause of abdominal hemorrhage after reduce-size liver transplantation in rats. METHODS: Healthy female SD rats were used as the donors and male SD rats as the recipients (weighing 260-280 g), with the recipients weighing 10 g more than that of the donors. The donor operation was performed by the same surgeon under direct vision, and the liver graft size reduction procedure was completed in the donor operation. The recipient operation was performed by two surgeons under direct vision. RESULTS: A total of 270 SD rats received reduce-size liver transplantation successfully, and 44 of the rats died from intra-abdominal hemorrhage. The abdominal hemorrhages, listed in the order of incidences, included anastomotic hemorrhage of the inferior vena cava of the superior liver (28 cases), subcapsular hemorrhage of the liver (9 cases), ligation hemorrhage of the left outboard lobe, the nipple lobe and the triangle lobe of the liver (9 , 7 and 7 cases, respectively), hemorrhage of the right suprarenal vein and lumbar veins (5 cases), hemorrhage of the mechanical injury (4 cases), cuff hemorrhage of the portal vein and inferior vein cava of the inferior liver (both 4 cases). Eight rats had anastomotic hemorrhage of the inferior vena cava of the superior liver and ligation hemorrhage of the left outboard lobe, 5 had hemorrhage of the two ligation points of the reduce-size liver; for management of the hemorrhage, 10 rats received suture or/and ligature, and 6 had washing and hot water bath. CONCLUSION: The most common cause of hemorrhage after reduce-size liver transplantation in rats is the anastomotic hemorrhage of the inferior vena cava of the superior liver, and this finding may provide clues for improving the success rate of reduced size liver transplantation in rats.