Effects and mechanisms of ziqi ruangan decoction on hepatic fibrosis

To investigate effect and mechanism of Ziqi Ruangan Decoction (ZQRGD) on hepatic fibrosis in rats. Rats were randomly assigned to blank group, model group, colchicine group, ZQRGD high-dose group, ZQRGD middle-dose group, and ZQRGD low-dose group. All groups except group A were intraperitoneally injected with 40% CCl4/olive oil for 8 weeks; group C was then given intragastric colchicine administration. Groups D, E, and F were intragastrically dosed with ZQRGD. Compared with the colchicine group, the superoxide dismutase (SOD) activity of each dose group of ZQRGD significantly increased. TNF-α and IL-6 concentration significantly decreased in each drug intervention group, while these significantly decreased in the high-dose and medium-dose ZQRGD groups. The expression of α-SMA and collagen I significantly decreased in the drug treatment group compared with the model group, as did the expression of PI3K, AKT, and mTOR. Ziqi Ruangan Decoction had a favorable anti-liver fibrosis effect and the mechanism is related to anti-oxidative stress, anti-inflammation, the inhibition of the PI3K/Akt/mTOR signaling pathway, and the inhibition of hepatic stellate cell activation.

Recent Progress in the Molecular Imaging of Nonalcoholic Fatty Liver Disease

Pathological fibrosis of the liver is a landmark feature in chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Diagnosis and assessment of progress or treatment efficacy today requires biopsy of the liver, which is a challenge in, e.g., longitudinal interventional studies. Molecular imaging techniques such as positron emission tomography (PET) have the potential to enable minimally invasive assessment of liver fibrosis. This review will summarize and discuss the current status of the development of innovative imaging markers for processes relevant for fibrogenesis in liver, e.g., certain immune cells, activated fibroblasts, and collagen depositions.

Reduction in SNAP-23 Alters Microfilament Organization in Myofibrobastic Hepatic Stellate Cells

Hepatic stellate cells (HSC) are critical effector cells of liver fibrosis. In the injured liver, HSC differentiate into a myofibrobastic phenotype. A critical feature distinguishing myofibroblastic from quiescent HSC is cytoskeletal reorganization. Soluble NSF attachment receptor (SNARE) proteins are important in trafficking of newly synthesized proteins to the plasma membrane for release into the extracellular environment. The goals of this project were to determine the expression of specific SNARE proteins in myofibroblastic HSC and to test whether their alteration changed the HSC phenotype in vitro and progression of liver fibrosis in vivo. We found that HSC lack the t-SNARE protein, SNAP-25, but express a homologous protein, SNAP-23. Downregulation of SNAP-23 in HSC induced reduction in polymerization and disorganization of the actin cytoskeleton associated with loss of cell movement. In contrast, reduction in SNAP-23 in mice by monogenic deletion delayed but did not prevent progression of liver fibrosis to cirrhosis. Taken together, these findings suggest that SNAP-23 is an important regular of actin dynamics in myofibroblastic HSC, but that the role of SNAP-23 in the progression of liver fibrosis in vivo is unclear.

Exosomal MALAT1 derived from hepatic cells is involved in the activation of hepatic stellate cells via miRNA-26b in fibrosis induced by arsenite

In the liver microenvironment, interactions among diverse types of hepatic cells are involved in liver fibrosis. In fibrotic tissues, exosomes act as transporters in intercellular communication. Long non-coding RNAs (lncRNAs) are involved in the activation of hepatic stellate cells (HSCs), which are participants in liver fibrosis. However, the functions of exosomal lncRNAs in liver fibrosis induced by arsenite are undefined. The purposes of the present study were (a) to determine if lncRNAs secreted from human hepatic (L-02) cells exposed to arsenite are shuttled to hepatic stellate LX-2 cells and (b) to establish their effects on LX-2 cells. In mice, MALAT1 was overexpressed in the progression of liver fibrosis induced by arsenite as well as in L-02 cells exposed to arsenite. Co-cultures with arsenite-treated L-02 cells induced the activation of LX-2 cells and overexpression of MALAT1. Arsenite-treated L-02 cells transported MALAT1 into LX-2 cells. Downregulation of MALAT1, which reduced the MALAT1 levels in exosomes derived from arsenite-treated L-02 cells, inhibited the activation of LX-2 cells. Additionally, exosomal MALAT1 derived from arsenite-treated L-02 cells promoted the activation of LX-2 cells via microRNA-26b regulation of COL1A2. Furthermore, circulating exosomal MALAT1 was up-regulated in people exposed to arsenite. In sum, exosomes derived from arsenite-treated hepatic cells transferred MALAT1 to HSCs, which induced their activation. These findings support the concept that, during liver fibrosis induced by arsenite, exosomal lncRNAs are involved in cell-cell communication.

Caveolin-1 is related to lipid droplet formation in hepatic stellate cells in human liver

Caveolins (CAVs) regulate intracellular cholesterol transport by a complex process involving caveolae, endoplasmic reticulum (ER), and the Golgi network. Hepatic stellate cells (HSCs) are the central site for retinoid storage in the liver and indeed the entire body. Herein, we attempted to elucidate the ultrastructural localization and expression of caveolin-1 (CAV-1) in human HSCs during the progression of liver cirrhosis (LC). Normal and hepatitis C-related cirrhotic liver samples were prepared using a modified perfusion-fixation method to fix organelle structures and molecules in their in vivo positions, and examined using immunoelectron microscopy. In control liver specimens, CAV-1 was minimally associated with low electron density lipid droplets (LDs) segregated around zones 1-2, and specifically associated with membranes surrounding LDs. CAV-1 was segregated in high-density LDs, consistent with the formation of membrane-enclosed lipid-rich vesicular structures, as well as caveolae on plasma membranes around zones 2-3. In cirrhotic liver specimens, CAV-1 molecules were inserted into the cytoplasmic leaflets of ER membranes for transportation to LDs. Thus, CAV-1 transport to LDs might represent an intracellular pathway from the ER in cirrhotic liver tissue.

Ultrastructural characteristics of the respective forms of hepatic stellate cells in chronic hepatitis B as an example of high fibroblastic cell plasticity. The first assessment in children

PURPOSE

Activation of hepatic stellate cells (HSCs), mainly responsible for extracellular matrix synthesis, is assumed to be central event in the process of liver fibrogenesis. The major objective of the research was to analyze the ultrastructural profile of activated HSCs in children with chronic hepatitis B (chB), with respect to fibrosis intensity.

MATERIALS/METHODS

Ultrastructural investigations of HSCs were conducted on liver bioptates from 70 children with clinicopathologically diagnosed chB before antiviral treatment. Biopsy material, fixed in paraformaldehyde and glutaraldehyde solution, was routinely processed for electron-microscopic analysis.

RESULTS

In children with intensive liver fibrosis (S-2 and S-3), the ultrastructural picture showed almost total replacement of quiescent HSCs (Q-HSCs) by activated, i.e. transitional HSCs (T-HSCs). Among T-HSCs, two types of cells were distinguished: cells exhibiting initiation of HSC activation (Ti-HSCs), never before described in chB, that were frequently accompanied by activated Kupffer cells, and cells with features of perpetuation of activation (Tp-HSCs). Tp-HSCs were elongated and characterized by substantial loss of cytoplasmic lipid material; they contained an increased number of cytoskeletal components, extremely dilated channels of granular endoplasmic reticulum and activated Golgi apparatus, which indicated their marked involvement in intensive synthesis of extracellular matrix proteins. Many collagen fibers were found to adhere directly to Tp-HSCs.

CONCLUSIONS

The current study showed T-HSCs to be an important link between Q-HSCs and myofibroblastic HSCs (Mf-HSCs). Transformation of HSCs into new morphological variations (Ti-HSCs; Tp-HSCs and Mf-HSCs), observed along with growing fibrosis, indicates their high plasticity and a key role in fibrogenesis in pediatric chB.

Hepatocyte nuclear factor 4α induces a tendency of differentiation and activation of rat hepatic stellate cells

AIM: To investigate the effect of hepatocyte nuclear factor 4α (HNF4α) on the differentiation and transformation of hepatic stellate cells (HSCs).

METHODS: By constructing the recombinant adenovirus vector expressing HNF4α and HNF4α shRNA vector, and manipulating HNF4α expression in HSC-T6 cells, we explored the influence of HNF4α and its induction capacity in the differentiation of rat HSCs into hepatocytes.

RESULTS: With increased expression of HNF4α mediated by AdHNF4α, the relative expression of Nanog was downregulated in HSC-T6 cells (98.33 ± 12.33 vs 41.33 ± 5.67, P < 0.001). Consequently, the expression of G-P-6 and PEPCK was upregulated (G-P-6: 14.34 ± 3.33 vs 42.53 ± 5.87, P < 0.01; PEPCK: 10.10 ± 4.67 vs 56.56 ± 5.25, P < 0.001), the expression of AFP and ALB was positive, and the expression of Nanog, Type I collagen, α-SMA, and TIMP-1 was significantly decreased. HNF4α also downregulated vimentin expression and enhanced E-cadherin expression. The ultrastructure of HNF4α-induced cells had more mitochondria and ribosomes compared with the parental cells. After silencing HNF4α expression, EPCK, E-cadherin, AFP, and ALB were downregulated and α-SMA and vimentin were upregulated.

CONCLUSION: HNF4α can induce a tendency of differentiation of HSCs into hepatocyte-like cells. These findings may provide an effective way for the treatment of liver diseases.

Early activated hepatic stellate cell-derived molecules reverse acute hepatic injury

AIM: To test whether hepatic stellate cells (HSCs) at different activation stages play different roles in acetaminophen (APAP)-induced acute liver injury (ALI).

METHODS: HSCs were isolated from mouse liver and cultured in vitro. Morphological changes of initiation HSCs [HSCs (5d)] and perpetuation HSCs [HSCs (p3)] were observed by immunofluorescence and transmission electron microscopy. The protective effects of HSC-derived molecules, cell lysates and HSC-conditioned medium (HSC-CM) were tested in vivo by survival and histopathological analyses. Liver injury was determined by measuring aminotransferase levels in the serum and by histologic examination of tissue sections under a light microscope. Additionally, to determine the molecular mediators of the observed protective effects of initiation HSCs, we examined HSC-CM using a high-density protein array.

RESULTS: HSCs (5d) and HSCs (p3) had different morphological and phenotypic traits. HSCs (5d) presented a star-shaped appearance with expressing α-SMA at non-uniform levels between cells. However, HSCs (p3) evolved into myofibroblast-like cells without lipid droplets and expressed a uniform and higher level of α-SMA. HSC-CM (5d), but not HSC-CM (p3), provided a significant survival benefit and showed a dramatic reduction of hepatocellular necrosis and panlobular leukocyte infiltrates in mice exposed to APAP. However, this protective effect was abrogated at higher cell masses, indicating a therapeutic window of effectiveness. Furthermore, the protein array screen revealed that HSC-CM (5d) was composed of many chemokines and growth factors that correlated with inflammatory inhibition and therapeutic activity. When compared with HSC-CM (p3), higher levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-1γ, hepatocyte growth factor, interleukin-10, and matrix metalloproteinase-2, but lower levels of stem cell factor and Fas-Ligand were observed in HSC-CM (5d).

CONCLUSION: These data indicated that initiation HSCs and perpetuation HSCs were different in morphology and protein expression, and provided the first experimental evidence of the potential medical value of initiation HSC-derived molecules in the treatment of ALI.

[Structure of venular vessels and cellular composition of hepatic sinusoidal capillaries in newborn infants]

The objective of this study was to identify the structural peculiarities of terminal interlobular venules and to determine the number of endotheliocytes, hepatic fat-storing cells (FSC) and stellate macrophages (SM) in the liver of newborn infants. Liver fragments were obtained from 5 healthy newborn infants during medico-legal autopsies. In the sections stained using Mallory's method, the relation of the connective tissue of terminal portal tracts with the adventitia of interlobular veins was determined. The numbers of endotheliocytes, FSC and CD68+ SM were counted in different zones of the liver acini. It was found that the adventitia of the terminal interlobular venules was completely represented by the connective tissue of the terminal portal tracts. Anastomoses with the sinusoidal capillaries (SC) via the circumlobular venules form the preterminal veins. FSC were concentrated in the central and periportal zones of the liver acinus, endotheliocytes of SC - in the periportal and peripheral zones, while SM were evenly distributed in all parts of the liver acinus. Thus, in newborn infants, liver cells possessing fibrogenic potential were numerous and were accumulated mainly near terminal interlobular venules, their circumlobular branches and within their adventitia.

Fabrication and characterization of an inorganic gold and silica nanoparticle mediated drug delivery system for nitric oxide

Nitric oxide (NO) plays an important role in inhibiting the development of hepatic fibrosis and its ensuing complication of portal hypertension by inhibiting human hepatic stellate cell (HSC) activation. Here we have developed a gold nanoparticle and silica nanoparticle mediated drug delivery system containing NO donors, which could be used for potential therapeutic application in chronic liver disease. The gold nanoconjugates were characterized using several physico-chemical techniques such as UV-visible spectroscopy and transmission electron microscopy. Silica nanoconjugates were synthesized and characterized as reported previously. NO released from gold and silica nanoconjugates was quantified under physiological conditions (pH = 7.4 at 37 degrees C) for a substantial period of time. HSC proliferation and the vascular tube formation ability, manifestations of their activation, were significantly attenuated by the NO released from these nanoconjugates. This study indicates that gold and silica nanoparticle mediated drug delivery systems for introducing NO could be used as a strategy for the treatment of hepatic fibrosis or chronic liver diseases, by limiting HSC activation.

Hepatitis B virus infects hepatic stellate cells and affects their proliferation and expression of collagen type I

BACKGROUND

Hepatitis B is at particularly high risk of fibrosis progression. Unfortunately, the mechanism of hepatic fibrogenesis induced by hepatitis B virus (HBV) has not been fully understood to date. The aim of this study was to observe whether HBV can infect hepatic stellate cells (HSCs), and to examine the effects of HBV or HBV S protein (HBs) on the proliferation and collagen type I expression of HSCs.

METHODS

The supernatants of HepG2.2.15 cells which contained HBV-DNA or HBs were added to LX-2 cells for 72 hours. Cell survival was determined by MTT assay. HBV particles in LX-2 cells were detected by transmission electron microscopy. The expression of HBs and HBV C protein (HBc) was determined by confocal fluorescence microscopy. The expression levels of HBV-DNA were measured by real-time PCR. The cellular collagen type I mRNA and protein levels were quantified by reverse transcription-PCR and ELISA, respectively.

RESULTS

High concentrations of HBV (1.2 x 10(5) - 5.0 x 10(5) copies/ml) or HBs (1.25 - 20 microg/ml) inhibited the proliferation of LX-2 cells, while low concentrations of HBV (1.0 x 10(3) - 6.2 x 10(4) copies/ml) or HBs (0.04 - 0.62 microg/ml) promoted the proliferation. After treating LX-2 cells with HBV for 72 hours, about 42 nm HBV-sized particles and strong expression of HBs and HBc were found in the cytoplasm of LX-2 cells. HBV-DNA in the culture medium of LX-2 cells decreased at 24 hours, rose at 48 hours and thereafter, decreased again at 72 hours. The mRNA and protein expression of cellular collagen type I in LX-2 cells were significantly increased by HBV infection but not by recombinant HBs.

CONCLUSIONS

HBV and HBs affect the proliferation of HSCs; HBV can transiently infect and replicate in cultured HSCs and express HBs and HBc in vitro. Furthermore, HBV can significantly increase the expression of collagen type I mRNA and protein in HSCs.

Comparative atomic force and scanning electron microscopy: an investigation of structural differentiation of hepatic stellate cells

The molecular mechanism leading to the transdifferentiation of hepatic stellate cells (HSC) into myofibroblast-like cells following liver injury is not well understood. The state of cultured rat HSCs was determined using primarily fluorescence microscopy (UV), immunofluorescence (IF) (Glial fibrillary acidic protein (GFAP), Desmin, alpha-smooth muscle actin (alpha-SMA), F-actin) and immunocytochemistry (ICC) (GFAP, Desmin, alpha-SMA, Fibulin-2). Additionally, tapping-mode atomic force microscopy (TM-AFM) and field-emission scanning electron microscopy (FE-SEM) with low-resistivity indium-tin-oxide (ITO) thin-film were performed to observe the micro-morphological character of cells during HSC differentiation. Quiescent HSCs changed to the activated state were identified via UV, IF, and ICC observations. Normal rat HSCs (NHSCs) and thioacetamide-induced rat HSCs (THSCs) were demonstrated to be UV(-), GFAP(+), Desmin(+), alpha-SMA(+) and Fibulin-2(-). After F-actin staining, lamellipodia and filopodia were found in both NHSCs and THSCs, but membrane ruffles were only seen in THSCs. The micro-structures of lamellipodia and filopodia in both NHSCs and THSCs were confirmed using FE-SEM and TM-AFM with ITO; in contrast, the micro-projection was not found. Moreover, "aerial root" structures were observed for the first time in the filopodia of THSCs using TM-AFM. These results reveal that HSC transdifferentiation to a myofibroblastic-like cell (activated HSC) from thioacetamide-induced rat HSC induces extensive changes in the cytoskeleton.

[Pathogenesis of liver fibrosis in patients with chronic hepatitis B]

OBJECTIVE

To explore the role of sinusoidal endothelial cell in the development of liver fibrosis, and to dissect the relationship among hepatic microcirculation disorders, hepatic sinusoidal capilarization and liver fibrosis.

METHODS

Liver biopsy was performed in fifty-six patients with chronic hepatitis B. The liver tissues were observed under light microscope and transmitted electronic microscope.

RESULTS

Of 56 cases, 39 cases were mild hepatitis, 10 were moderate hepatitis, and 7 were severe hepatitis. The morphology of hepatic stellate cells (HSCs) was similar to that of fibroblasts in the tissues of the patients with chronic hepatitis B. Collagenous fibers were deposited around the hepatic stellate cells. Electron-dense materials were deposited between sinusoidal endothelial cell and hepatic stellate cell. The size and amount of fenestraes of sinusoidal endothelial cells were reduced in 53 of 56 cases. The consecutive or inconsecutive membrane-like materials were observed along sinusoidal endothelial cells in 20 cases. Collagen fibers were observed in the space of Disse in 15 cases. Even in the patients with normal hepatic functions, red blood cells aggregation and microthrombi could be observed in the liver tissues.

CONCLUSION

Sinusoidal endothelial cells are involved in development of liver fibrosis by interacting with hepatic stellate cells. Hepatic microcirculation disorders and sinusoidal capillarization are important changes in the early stage of liver fibrosis.

Hepatic stellate cell lipid droplets: a specialized lipid droplet for retinoid storage

The majority of retinoid (vitamin A and its metabolites) present in the body of a healthy vertebrate is contained within lipid droplets present in the cytoplasm of hepatic stellate cells (HSCs). Two types of lipid droplets have been identified through histological analysis of HSCs within the liver: smaller droplets bounded by a unit membrane and larger membrane-free droplets. Dietary retinoid intake but not triglyceride intake markedly influences the number and size of HSC lipid droplets. The lipids present in rat HSC lipid droplets include retinyl ester, triglyceride, cholesteryl ester, cholesterol, phospholipids and free fatty acids. Retinyl ester and triglyceride are present at similar concentrations, and together these two classes of lipid account for approximately three-quarters of the total lipid in HSC lipid droplets. Both adipocyte-differentiation related protein and TIP47 have been identified by immunohistochemical analysis to be present in HSC lipid droplets. Lecithin:retinol acyltransferase (LRAT), an enzyme responsible for all retinyl ester synthesis within the liver, is required for HSC lipid droplet formation, since Lrat-deficient mice completely lack HSC lipid droplets. When HSCs become activated in response to hepatic injury, the lipid droplets and their retinoid contents are rapidly lost. Although loss of HSC lipid droplets is a hallmark of developing liver disease, it is not known whether this contributes to disease development or occurs simply as a consequence of disease progression. Collectively, the available information suggests that HSC lipid droplets are specialized organelles for hepatic retinoid storage and that loss of HSC lipid droplets may contribute to the development of hepatic disease.