Taurine attenuates activation of hepatic stellate cells by inhibiting autophagy and inducing ferroptosis.

BACKGROUND: Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury, and finally leads to liver cirrhosis or even hepatocellular carcinoma. The pathogenesis of hepatic fibrosis is associated with the progressive accumulation of activated hepatic stellate cells (HSCs), which can transdifferentiate into myofibroblasts to produce an excess of the extracellular matrix (ECM). Myofibroblasts are the main source of the excessive ECM responsible for hepatic fibrosis. Therefore, activated hepatic stellate cells (aHSCs), the principal ECM producing cells in the injured liver, are a promising therapeutic target for the treatment of hepatic fibrosis. AIM: To explore the effect of taurine on aHSC proliferation and the mechanisms involved. METHODS: Human HSCs (LX-2) were randomly divided into five groups: Normal control group, platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) treated group, and low, medium, and high dosage of taurine (10 mmol/L, 50 mmol/L, and 100 mmol/L, respectively) with PDGF-BB (20 ng/mL) treated group. Cell Counting Kit-8 method was performed to evaluate the effect of taurine on the viability of aHSCs. Enzyme-linked immunosorbent assay was used to estimate the effect of taurine on the levels of reactive oxygen species (ROS), malondialdehyde, glutathione, and iron concentration. Transmission electron microscopy was applied to observe the effect of taurine on the autophagosomes and ferroptosis features in aHSCs. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to detect the effect of taurine on the expression of α-SMA, Collagen I, Fibronectin 1, LC3B, ATG5, Beclin 1, PTGS2, SLC7A11, and p62. RESULTS: Taurine promoted the death of aHSCs and reduced the deposition of the ECM. Treatment with taurine could alleviate autophagy in HSCs to inhibit their activation, by decreasing autophagosome formation, downregulating LC3B and Beclin 1 protein expression, and upregulating p62 protein expression. Meanwhile, treatment with taurine triggered ferroptosis and ferritinophagy to eliminate aHSCs characterized by iron overload, lipid ROS accumulation, glutathione depletion, and lipid peroxidation. Furthermore, bioinformatics analysis demonstrated that taurine had a direct targeting effect on nuclear receptor coactivator 4, exhibiting the best average binding affinity of -20.99 kcal/mol. CONCLUSION: Taurine exerts therapeutic effects on liver fibrosis via mechanisms that involve inhibition of autophagy and trigger of ferroptosis and ferritinophagy in HSCs to eliminate aHSCs.

Single-Cell Transcriptome Analysis Uncovers Intratumoral Heterogeneity and Underlying Mechanisms for Drug Resistance in Hepatobiliary Tumor Organoids.

Molecular heterogeneity of hepatobiliary tumor including intertumoral and intratumoral disparity always leads to drug resistance. Here, seven hepatobiliary tumor organoids are generated to explore heterogeneity and evolution via single-cell RNA sequencing. HCC272 with high status of epithelia-mesenchymal transition proves broad-spectrum drug resistance. By examining the expression pattern of cancer stem cells markers (e.g., PROM1, CD44, and EPCAM), it is found that CD44 positive population may render drug resistance in HCC272. UMAP and pseudo-time analysis identify the intratumoral heterogeneity and distinct evolutionary trajectories, of which catenin beta-1 (CTNNB1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and nuclear paraspeckle assembly transcript 1 (NEAT1) advantage expression clusters are commonly shared across hepatobiliary organoids. CellphoneDB analysis further implies that metabolism advantage organoids with enrichment of hypoxia signal upregulate NEAT1 expression in CD44 subgroup and mediate drug resistance that relies on Jak-STAT pathway. Moreover, metabolism advantage clusters shared in several organoids have similar characteristic genes (GAPDH, NDRG1 (N-Myc downstream regulated 1), ALDOA, and CA9). The combination of GAPDH and NDRG1 is an independent risk factor and predictor for patient survival. This study delineates heterogeneity of hepatobiliary tumor organoids and proposes that the collaboration of intratumoral heterogenic subpopulations renders malignant phenotypes and drug resistance.

High Serum Levels of Cholesterol Increase Antitumor Functions of Nature Killer Cells and Reduce Growth of Liver Tumors in Mice.

BACKGROUND AND AIMS: The relationship between serum cholesterol level and development of hepatocellular carcinoma (HCC) remains unclear. We investigated the effects of serum cholesterol level on development of liver tumors in mice. METHODS: We performed studies with C57BL/6J mice, mice with disruption of the low-density lipoprotein receptor gene (Ldlr-/-mice), and mice with conditional deletion of nature killer (NK) cells (NKdele mice). Some C57BL/6J and NKdele mice were given injections of diethylinitrosamine to induce liver tumor formation. Mice were placed on a normal diet (ND) or high-cholesterol diet (HCD) to induce high serum levels of cholesterol. We also studied mice with homozygous disruption of ApoE (ApoE-/- mice), which spontaneously develop high serum cholesterol. C57BL/6J and NKdele mice on the ND or HCD were implanted with Hep1-6 (mouse hepatoma) cells and growth of xenograft tumors and lung metastases were monitored. Blood samples were collected from mice and analyzed by biochemistry and flow cytometry; liver and tumor tissues were collected and analyzed by histology, immunohistochemistry, and RNA-sequencing analysis. NK cells were isolated from mice and analyzed for cholesterol content, lipid raft formation, immune signaling, and changes in functions. We obtained matched tumor tissues and blood samples from 30 patients with HCC and blood samples from 40 healthy volunteers; levels of cholesterol and cytotoxicity of NK cells were measured. RESULTS: C57BL/6J mice on HCD and ApoE-/- mice with high serum levels of cholesterol developed fewer and smaller liver tumors and lung metastases after diethylinitrosamine injection or implantation of Hep1-6 cells than mice on ND. Liver tumors from HCD-fed mice and ApoE-/- mice had increased numbers of NK cells compared to tumors from ND-fed mice. NKdele mice or mice with antibody-based depletion for NK cells showed similar tumor number and size in ND and HCD groups after diethylinitrosamine injection or implantation of Hep1-6 cells. NK cells isolated from C57BL/6J mice fed with HCD had increased expression of NK cell-activating receptors (natural cytotoxicity triggering receptor 1 and natural killer group 2, member D), markers of effector function (granzyme B and perforin), and cytokines and chemokines compared with NK cells from mice on ND; these NK cells also had enhanced cytotoxic activity against mouse hepatoma cells, accumulated cholesterol, increased lipid raft formation, and immune signaling activation. NK cells isolated from HCD-fed Ldlr-/- mice did not have increased cholesterol content or cytotoxic activity against mouse hepatoma cells compared with ND-fed Ldlr-/- mice. Serum levels of cholesterol correlated with number and activity of NK cells isolated from human HCCs. CONCLUSIONS: Mice with increased serum levels of cholesterol due to an HCD or genetic disruption of ApoE develop fewer and smaller tumors after injection of hepatoma cells or a chemical carcinogen. We found cholesterol to accumulate in NK cells and activate their effector functions against hepatoma cells. Strategies to increase cholesterol uptake by NK cells can be developed for treatment of HCC.

Integrated network analysis of transcriptomic and protein-protein interaction data in taurine-treated hepatic stellate cells.

BACKGROUND: Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells (HSCs). Since the molecular mechanism of taurine-mediated antifibrotic activity has not been fully unveiled and is little studied, it is imperative to use "omics" methods to systematically investigate the molecular mechanism by which taurine inhibits liver fibrosis. AIM: To establish a network including transcriptomic and protein-protein interaction data to elucidate the molecular mechanism of taurine-induced HSC apoptosis. METHODS: We used microarrays, bioinformatics, protein-protein interaction (PPI) network, and sub-modules to investigate taurine-induced changes in gene expression in human HSCs (LX-2). Subsequently, all of the differentially expressed genes (DEGs) were subjected to gene ontology function and Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Furthermore, the interactions of DEGs were explored in a human PPI network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software. RESULTS: A total of 635 DEGs were identified in taurine-treated HSCs when compared with the controls. Of these, 304 genes were statistically significantly up-regulated, and 331 down-regulated. Most of these DEGs were mainly located on the membrane and extracellular region, and are involved in the biological processes of signal transduction, cell proliferation, positive regulation of extracellular regulated protein kinases 1 (ERK1) and ERK2 cascade, extrinsic apoptotic signaling pathway and so on. Fifteen significantly enriched pathways with DEGs were identified, including mitogen-activated protein kinase (MAPK) signaling pathway, peroxisome proliferators-activated receptor signaling pathway, estrogen signaling pathway, Th1 and Th2 cell differentiation, cyclic adenosine monophosphate signaling pathway and so on. By integrating the transcriptomics and human PPI data, nine critical genes, including MMP2, MMP9, MMP21, TIMP3, KLF10, CX3CR1, TGFB1, VEGFB, and EGF, were identified in the PPI network analysis. CONCLUSION: Taurine promotes the apoptosis of HSCs via up-regulating TGFB1 and then activating the p38 MAPK-JNK-Caspase9/8/3 pathway. These findings enhance the understanding of the molecular mechanism of taurine-induced HSC apoptosis and provide references for liver disorder therapy.

The potential role of HO-1 in regulating the MLK3-MKK7-JNK3 module scaffolded by JIP1 during cerebral ischemia/reperfusion in rats.

Heme oxygenase (HO-1), which may be induced by Cobaltic protoporphyrin IX chloride (CoPPIX) or Rosiglitazone (Ros), is a neuroprotective agent that effectively reduces ischemic stroke. Previous studies have shown that the neuroprotective mechanisms of HO-1 are related to JNK signaling. The expression of HO-1 protects cells from death through the JNK signaling pathway. This study aimed to ascertain whether the neuroprotective effect of HO-1 depends on the assembly of the MLK3-MKK7-JNK3 signaling module scaffolded by JIP1 and further influences the JNK signal transmission through HO-1. Prior to the ischemia-reperfusion experiment, CoPPIX was injected through the lateral ventricle for 5 consecutive days or Ros was administered via intraperitoneal administration in the week prior to transient ischemia. Our results demonstrated that HO-1 could inhibit the assembly of the MLK3-MKK7-JNK3 signaling module scaffolded by JIP1 and could ultimately diminish the phosphorylation of JNK3. Furthermore, the inhibition of JNK3 phosphorylation downregulated the level of p-c-Jun and elevated neuronal cell death in the CA1 of the hippocampus. Taken together, these findings suggested that HO-1 could ameliorate brain injury by regulating the MLK3-MKK7-JNK3 signaling module, which was scaffolded by JIP1 and JNK signaling during cerebral ischemia/reperfusion.

A Novel Tropoloisoquinoline Alkaloid, Neotatarine, from Acorus calamus L.

A novel tropoloisoquinoline alkaloid, neotatarine (1), was isolated from the 95% ethanol extract of the rhizome parts of Acorus calamus L. The chemical structure was unambiguously elucidated by spectroscopic and single-crystal X-ray diffraction analysis. Neotatarine (1) exhibited significantly inhibitory activity against Aß25 - 35 induced PC12 cell death with 2, 4 and 8 µm comparing with the assay control (P < 0.01).

Linc00152 promotes cancer progression in hepatitis B virus-associated hepatocellular carcinoma.

BACKGROUND: The X protein (HBx) plays as a key role in hepatocarcinogenesis associated with hepatitis B virus (HBV) infections. The study aimed to figure out the role of Linc00152 in hepatocellular carcinoma (HCC) and the association between the expression levels of Linc00152 and HBx. METHODS: QRT-PCR assays were applied to analyzed the expression levels of Linc00152 and HBx. Kaplan-Meier survival curve was performed to identify the association between LINC00152 and the over survival time (OS) in HCC patients. Cell growth and invasion ability was evaluated by CCK8 cell proliferation and transwell invasion assays. Western-blot analysis was detected the protein expression. RNA immunoprecipitation (RIP), RNA-pull down and chromatin Immunoprecipitation (ChIP) assays was also been carried out. RESULTS: We demonstrated that LINC00152 expression in hepatocellular carcinoma (HCC) patients was significantly higher compared with adjacent non-tumour tissues and positively correlated with tumor size, HBV infection (HBsAg) and tumor number. Patient with hepatitis B virus (HBV) infection HCC was higher expression than that without HBV. Furthermore, the expression levels of Linc00152 were positively correlated with HBx expression in HCC tissues and higher Linc00152 expression levels were correlated with poor prognosis of HCC patients. In vitro, Linc00152 was up-regulated in Huh-7 and SM7721 cells after overexpression of HBx and down-regulated after silencing HBx. Furthermore, silencing Linc00152 suppressed the cell proliferation and invasion. Moreover, we found that Linc00152 inhibited the E-cadherin expression via interacting with EZH2 and promoted the Epithelial-mesenchymal transition (EMT) phenomenon in HCC cells. CONCLUSIONS: These results suggested that HBx enhanced LINC00152 expression and inhibition of LINC00152 could provide a therapeutic target for HCC.

[Determination of five pyrethroid pesticides residues in Anoectochilus roxburghii by cloud point extraction-back extraction and GC-MS].

A method for residual determination of 5 pyrethroid pesticides in Anoectochilus roxburghii by cloud point extraction-back extraction-GC-MS was established. PEG 6000 was used as extraction agent and isooctane was used for back-extractant. The con- tent was calculated by external standard method. The linear range was from 15 to 2 000 µg x kg(-1) with the good correlation coefficients (0.955-0.999). The recoveries at spiked concentrations of 50-500 µg x kg(-1) ranged from 85.12% to 101.6%. The limit of detection and quantification of 5 pyrethroid pesticides were in the range of 0.63-3.10 µg x kg(-1) and 2.10-10.31 µg x kg(-1), respectively. The proposed method can be applied to the determination of pyrethroid pesticides residues in A. roxburghii.

[A preliminary study of anti-aging and wound healing of recombination cytoglobin].

In this paper, the preliminary study on antioxidant, enhancement of antioxidant enzymes activity, reducing the content of oxygen free radicals, delaying skin aging of the recombination cytoglobin (rCygb) purified by our lab were investigated through human keratinocyte cell line (HaCAT) H2O2 oxidative stress model, mouse skin aging model caused by continuous subcutaneous injection D-gal, rat acute liver injury model induced by CCl4 and rat skin wound healing model. The results showed that rCygb improved the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), reduced the activities of lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) as well as decreased the content of malondialdehyde (MDA). Skin biopsy showed that rCygb promoted angiogenesis, increased expression of collagen and improved the anti-inflammatory ability. All results displayed that rCygb improved the oxygen free radical scavenging ability, delayed skin aging and promoted wound healing.

p28(GANK) prevents degradation of Oct4 and promotes expansion of tumor-initiating cells in hepatocarcinogenesis.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is believed to arise from tumor-initiating cells (T-ICs), although little is known about their stem cell-like properties. METHODS: We quantified levels of p28(GANK) (Gankyrin), OV6, and Oct4 in 130 human HCC samples using immunohistochemistry. Magnetic-activated cell sorting was used to isolate OV6+ HCC cells. T-IC properties were evaluated by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and spheroid formation. We used a coimmunoprecipitation assay to study interactions among p28(GANK), Oct4, and WWP2. Tumorigenicity and pulmonary metastasis were examined in nonobese diabetic and severe combined immunodeficient mice. RESULTS: In HCC samples, high levels of p28(GANK) correlated with expansion of OV6+ tumor cells; the combination of high levels of p28(GANK) and OV6 was associated with progression of HCC. p28(GANK) was predominantly expressed in liver T-ICs, isolated by magnetic sorting, and undifferentiated primary HCC spheroids. Increased levels of p28(GANK) in T-ICs increased their percentages in HCC samples, expression of stem cell genes, self-renewal potential, chemoresistance in vitro, and tumorigenicity and ability to develop into pulmonary metastases in mice. Conversely, knockdown of p28(GANK) reduced their T-IC properties. p28(GANK) likely activates liver T-ICs by impeding ubiquitination and degradation of the transcription factor Oct4 by WWP2. In support of this concept, levels of p28(GANK) correlated with those of Oct4 in HCC samples. CONCLUSIONS: p28(GANK) activates and maintains liver T-ICs in HCCs by preventing degradation of Oct4. Inhibitors of p28(GANK) might therefore be developed to inactivate T-ICs and slow tumor progression.