Function and biomedical implications of exosomal microRNAs delivered by parenchymal and nonparenchymal cells in hepatocellular carcinoma.

Small extracellular vesicles (exosomes) are important components of the tumor microenvironment. They are small membrane-bound vesicles derived from almost all cell types and play an important role in intercellular communication. Exosomes transmit biological molecules obtained from parent cells, such as proteins, lipids, and nucleic acids, and are involved in cancer development. MicroRNAs (miRNAs), the most abundant contents in exosomes, are selectively packaged into exosomes to carry out their biological functions. Recent studies have revealed that exosome-delivered miRNAs play crucial roles in the tumorigenesis, progression, and drug resistance of hepatocellular carcinoma (HCC). In addition, exosomes have great industrial prospects in the diagnosis, treatment, and prognosis of patients with HCC. This review summarized the composition and function of exosomal miRNAs of different cell origins in HCC and highlighted the association between exosomal miRNAs from stromal cells and immune cells in the tumor microenvironment and the progression of HCC. Finally, we described the potential applicability of exosomal miRNAs derived from mesenchymal stem cells in the treatment of HCC.

Liver injury changes the biological characters of serum small extracellular vesicles and reprograms hepatic macrophages in mice.

BACKGROUND: Serum small extracellular vesicles (sEVs) and their small RNA (sRNA) cargoes could be promising biomarkers for the diagnosis of liver injury. However, the dynamic changes in serum sEVs and their sRNA components during liver injury have not been well characterized. Given that hepatic macrophages can quickly clear intravenously injected sEVs, the effect of liver injury-related serum sEVs on hepatic macrophages deserves to be explored. AIM: To identify the characteristics of serum sEVs and the sRNAs during liver injury and explore their effects on hepatic macrophages. METHODS: To identify serum sEV biomarkers for liver injury, we established a CCL4-induced mouse liver injury model in C57BL/6 mice to simulate acute liver injury (ALI), chronic liver injury (CLI) and recovery. Serum sEVs were obtained and characterized by transmission electron microscopy and nanoparticle tracking analysis. Serum sEV sRNAs were profiled by sRNA sequencing. Differentially expressed microRNAs (miRNAs) were compared to mouse liver-enriched miRNAs and previously reported circulating miRNAs related to human liver diseases. The biological significance was evaluated by Ingenuity Pathway Analysis of altered sEV miRNAs and conditioned cultures of ALI serum sEVs with primary hepatic macrophages. RESULTS: We found that both ALI and CLI changed the concentration and morphology of serum sEVs. The proportion of serum sEV miRNAs increased upon liver injury, with the liver as the primary contributor. The altered serum sEV miRNAs based on mouse studies were consistent with human liver disease-related circulating miRNAs. We established serum sEV miRNA signatures for ALI and CLI and a panel of miRNAs (miR-122-5p, miR-192-5p, and miR-22-3p) as a common marker for liver injury. The differential serum sEV miRNAs in ALI contributed mainly to liver steatosis and inflammation, while those in CLI contributed primarily to hepatocellular carcinoma and hyperplasia. ALI serum sEVs decreased both CD86 and CD206 expression in monocyte-derived macrophages but increased CD206 expression in resident macrophages in vitro. CONCLUSION: Serum sEVs acquired different concentrations, sizes, morphologies and sRNA contents upon liver injury and could change the phenotype of liver macrophages. Serum sEVs therefore have good diagnostic and therapeutic potential for liver injury.

External validation and comparison of six prognostic models in a prospective cohort of HBV-ACLF in China.

UNLABELLED:  Background. Acute-on-chronic liver failure has high mortality. Currently, robust models for predicting the outcome of hepatitis B virus (HBV)-associated ACLF are lacking. AIM: To assess and compare the performance of six prevalent models for short- and longterm prognosis in patients with HBV-ACLF. MATERIAL AND METHODS: The model for end-stage liver disease (MELD), MELD sodium (MELD-Na), MELD to sodium ratio (MESO), integrated MELD, Child-Turcotte-Pugh (CTP), and modified CTP (mCTP) were validated in a prospective cohort of 232 HBV-ACLF patients. The six models were evaluated by determining discrimination, calibration and overall performance at 3 months and 5 years. RESULTS: According to the Hosmer-Lemeshow tests and calibration plots, all models could adequately describe the data except CTP at 3 months. Discrimination analysis showed that the iMELD score had the highest AUC of 0.76 with sensitivity of 62.6% and specificity of 80.2% for an optimal cut-off value of 52 at 3 months. It also had the highest AUC of 0.80 with sensitivity of 89.9% and specificity of 48.2% for an optimal cut-off value of 43 at 5 years. The overall performance of iMELD, assessed with Nagelkerke's R2 and the Brier score, was also the best among the six models. CONCLUSION: Integrated MELD may be the best model to predict short- and long-term prognosis in patients with HBV-ACLF.

Quantitative proteomics analysis of chondrogenic differentiation of C3H10T1/2 mesenchymal stem cells by iTRAQ labeling coupled with on-line two-dimensional LC/MS/MS.

The chondrogenic potential of multipotent mesenchymal stem cells (MSCs) makes them a promising source for cell-based therapy of cartilage defects; however, the exact intracellular molecular mechanisms of chondrogenesis as well as self-renewal of MSCs remain largely unknown. To gain more insight into the underlying molecular mechanisms, we applied isobaric tag for relative and absolute quantitation (iTRAQ) labeling coupled with on-line two-dimensional LC/MS/MS technology to identify proteins differentially expressed in an in vitro model for chondrogenesis: chondrogenic differentiation of C3H10T1/2 cells, a murine embryonic mesenchymal cell line, was induced by micromass culture and 100 ng/ml bone morphogenetic protein 2 treatment for 6 days. A total of 1756 proteins were identified with an average false discovery rate <0.21%. Linear regression analysis of the quantitative data gave strong correlation coefficients: 0.948 and 0.923 for two replicate two-dimensional LC/MS/MS analyses and 0.881, 0.869, and 0.927 for three independent iTRAQ experiments, respectively (p < 0.0001). Among 1753 quantified proteins, 100 were significantly altered (95% confidence interval), and six of them were further validated by Western blotting. Functional categorization revealed that the 17 up-regulated proteins mainly comprised hallmarks of mature chondrocytes and enzymes participating in cartilage extracellular matrix synthesis, whereas the 83 down-regulated were predominantly involved in energy metabolism, chromatin organization, transcription, mRNA processing, signaling transduction, and cytoskeleton; except for a number of well documented proteins, the majority of these altered proteins were novel for chondrogenesis. Finally, the biological roles of BTF3l4 and fibulin-5, two novel chondrogenesis-related proteins identified in the present study, were verified in the context of chondrogenic differentiation. These data will provide valuable clues for our better understanding of the underlying mechanisms that modulate these complex biological processes and assist in the application of MSCs in cell-based therapy for cartilage regeneration.

[Comprehensive proteome profile of activated rat hepatic stellate cells].

OBJECTIVE: To profile the protein expression in activated rat hepatic stellate cells (HSCs). METHODS: Primary rat HSCs were isolated and cultured in vitro. After 10 days in vitro culture, the HSCs were activated. Total protein extracted from these activated HSCs were digested, and the obtained peptides were analyzed by using online 2D nanoLC-MS/MS. The identified proteins were classified according to their distributions and functions. RESULTS: 1014 proteins were identified from 50 microg HSCs protein extract, the molecular weights of these proteins ranged from 7832 Da to 588,364 Da. Most of these proteins resided in nucleus, cytoskeleton, mitochondrion and endoplasmic reticulum. And these proteins were mainly involved in nucleic acid metabolism, organelle organization, signal transduction and energy generation. Among these proteins, alpha-smooth muscle actin, vimentin and desmin were specifically expressed in activated HSCs. CONCLUSION: To the best of our knowledge, this is the most comprehensive protein expression profile of activated rat HSCs.

Fenretinide stimulates the apoptosis of hepatic stellate cells and ameliorates hepatic fibrosis in mice.

AIM: To investigate whether fenretinide, a clinically proved apoptosis-inducing chemopreventive agent in tumor cells, can induce apoptosis in hepatic stellate cells (HSCs) and resolve hepatic fibrosis. METHODS: CCl(4)-induced liver fibrosis in mice and rat activated hepatic stellate cells (HSC-T6) as well as hepatocytes (BRL-3A) were studied. RESULTS: The duplex staining of proliferating cell nuclear antigen and alpha- smooth muscle actin or terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and alpha- smooth muscle actin demonstrated that fenretinide executed its anti-fibrosis effect in liver by inducing apoptosis rather than inhibiting proliferation of HSCs, while it had no apparently apoptotic effect on hepatocytes. Fenretinide could elicit apoptosis of HSC-T6 in vitro at the concentration range from 0.5 to 5 microM, but at higher concentrations >/=5 microM was required to induce apoptosis in hepatocytes (BRL-3A). CONCLUSION: Further studies using malondialdehyde measurement, Western blot, antioxidant, inhibitors for p53, caspase 8 and 9 - as well as anti-Fas neutralizing antibody - have shown that in HSC-T6, fenretinide-induced apoptosis involves a reactive oxygen species (ROS)-generated, P53-independent, mitochondria-associated intrinsic pathway, whereas in hepatocytes (BRL-3A), a ROS-generated, P53-dependent, Fas-related extrinsic pathway is triggered only at high concentration.