Conference Abstract| February 01 2004 The Role of the Extracellular Matrix in the Development of Colorectal Cancer Liver Metastases J.A. Conti; J.A. Conti *Division of Cancer Science, University of Southampton†Division of Infection, Inflammation and Repair, University of Southampton Search for other works by this author on: This Site PubMed Google Scholar R.C. Benyon; R.C. Benyon †Division of Infection, Inflammation and Repair, University of Southampton Search for other works by this author on: This Site PubMed Google Scholar J.N. Primrose; J.N. Primrose *Division of Cancer Science, University of Southampton Search for other works by this author on: This Site PubMed Google Scholar J.P. Iredale J.P. Iredale †Division of Infection, Inflammation and Repair, University of Southampton Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (2004) 106 (s50): 2P. https://doi.org/10.1042/cs106002P Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation J.A. Conti, R.C. Benyon, J.N. Primrose, J.P. Iredale; The Role of the Extracellular Matrix in the Development of Colorectal Cancer Liver Metastases. Clin Sci (Lond) 1 February 2004; 106 (s50): 2P. doi: https://doi.org/10.1042/cs106002P Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 2004 The Biochemical Society and the Medical Research Society2004 Article PDF first page preview Close Modal You do not currently have access to this content.

Collagen-I, which predominates in the neomatrix of fibrotic liver, regulates hepatocyte and hepatic stellate cell (HSC) phenotypes. Recovery from liver fibrosis is accompanied by hepatocyte regeneration, matrix degradation, and HSC apoptosis. Using mice bearing a mutated collagen-I gene (r/r mice), which confers resistance to collagenase degradation, we have investigated the hypothesis that collagen-I degradation is critical to HSC apoptosis and hepatocyte regeneration during recovery from liver fibrosis. During a 28-day recovery period after 8 wk of CCl4 treatment, wild-type (WT) livers had significantly (43%) decreased hydroxyproline (OHP) content. In r/r livers, however, OHP content remained elevated at peak fibrosis levels. Expressed markers of activated HSC (alpha-smooth muscle actin, collagen-I), elevated at peak fibrosis, dropped to control levels in WT livers after 28 days but remained raised in the r/r livers. Moreover, relative to WT livers, r/r livers had significantly reduced stellate cell apoptosis and hepatocyte regeneration during the recovery period. Using extracted collagen-I from each genotype as culture substrata, relative to r/r, we show that WT collagen-I promotes hepatocyte proliferation via stimulation of integrin alphavbeta(3). Failure to degrade collagen-I critically impairs HSC apoptosis and may prevent the effective restoration of hepatocyte mass in liver fibrosis.

Conference Abstract| July 01 2002 Inhibition of Apoptosis of Activated Hepatic Stellate Cells by Timp-1 is Mediated via Effects on Mmp Inhibition: Implications for Reversibility of Liver Fibrosis F. Murphy; F. Murphy 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar R. Issa; R. Issa 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar X. Zhou; X. Zhou 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar H. Hussain; H. Hussain 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar S. Ratnarajah; S. Ratnarajah 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar P. Soloway; P. Soloway 1Rosewell Park Cancer Institute, New York, USA Search for other works by this author on: This Site PubMed Google Scholar H. Nagase; H. Nagase 2 The Kennedy Institute, Imperial College, London, UK Search for other works by this author on: This Site PubMed Google Scholar Arthur Mjp; Arthur Mjp 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar RC Benyon; RC Benyon 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar JP Iredale JP Iredale 1Liver Group, Division of Infection, Inflammation & Repair, Southampton University, Southampton, SO16 6YD Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (2002) 103 (s47): 40P. https://doi.org/10.1042/cs103040P Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation F. Murphy, R. Issa, X. Zhou, H. Hussain, S. Ratnarajah, P. Soloway, H. Nagase, Arthur Mjp, RC Benyon, JP Iredale; Inhibition of Apoptosis of Activated Hepatic Stellate Cells by Timp-1 is Mediated via Effects on Mmp Inhibition: Implications for Reversibility of Liver Fibrosis. Clin Sci (Lond) 1 July 2002; 103 (s47): 40P. doi: https://doi.org/10.1042/cs103040P Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 2002 The Biochemical Society and the Medical Research Society2002 Article PDF first page preview Close Modal You do not currently have access to this content.

The activated hepatic stellate cell (HSC) is central to liver fibrosis as the major source of collagens I and III and the tissue inhibitors of metalloproteinase-1 (TIMP-1). During spontaneous recovery from liver fibrosis, there is a decrease of TIMP expression, an increase in collagenase activity, and increased apoptosis of HSC, highlighting a potential role for TIMP-1 in HSC survival. In this report, we use tissue culture and in vivo models to demonstrate that TIMP-1 directly inhibits HSC apoptosis. TIMP-1 demonstrated a consistent, significant, and dose-dependent antiapoptotic effect for HSC activated in tissue culture and stimulated to undergo apoptosis by serum deprivation, cycloheximide exposure, and nerve growth factor stimulation. A nonfunctional mutated TIMP-1 (T2G mutant) in which all other domains are conserved did not inhibit apoptosis, indicating that inhibition of apoptosis was mediated through MMP inhibition. Synthetic MMP inhibitors also inhibited HSC apoptosis. Studies of experimental liver cirrhosis demonstrated that persistent expression of TIMP-1 mRNA determined by PCR correlated with persistence of activated HSC quantified by alpha smooth muscle actin staining, while in fibrosis, loss of activated HSC correlated with a reduction in TIMP-1 mRNA. We conclude that TIMP-1 inhibits apoptosis of activated HSC via MMP inhibition.

Hepatic fibrosis is a progressive debilitating disease which if left unchecked leads to cirrhosis and liver failure. To date, transplantation remains the only clinical treatment. The molecular mechanisms which lead to fibrosis represent an area of intensive study and it is now clear that hepatic stellate cells (HSCs) play a pivotal role in this process. As a first step to developing an effective anti-fibrotic chemotherapy, we have undertaken a global genetic analysis of HSC activation using Affymetrix GeneChip™ HG-U95A, which represents up to 11 000 characterised human genes. We have analysed pairwise, matched HSCs either freshly isolated (designated as “quiescent”), or activated by culture on plastic in the presence of 16% serum, from three independent healthy human liver samples at n=>4 for each condition. All three datasets show uniform host control gene expression and hybridisation controls. Our three datasets exhibit a consistent number of expressed genes (4000–5000 active in both quiescent and activated HSCs). In addition, ~2200 genes are consistently modulated upon activation, of which ~1000 genes are upregulated and ~1200 are downregulated. Furthermore, 900 gene modulations (~40%) are common to all three samples which is extremely high agreement when compared to other gene profiling studies using established or transformed cell lines. Finally, further analysis shows that ~400 genes are consistently and significantly upregulated during HSC activation. Many of the collagen genes are represented in the upregulated genes as expected for a model for fibrosis. Other identified genes which are modulated include those for cell motility, growth factors/receptors, TGF signalling, ECM remodelling, and those genes which are established markers for activation—for example, ?-smooth muscle actin. We intend using these datasets to target pathways for therapeutic intervention to help prevent hepatic fibrosis caused, for example by chronic HCV infection. Such an anti-fibrotic therapy, allied to an anti-HCV viral therapy, would meet an urgent clinical need

Although liver cirrhosis is considered to be irreversible, examples of spontaneous resolution of advanced fibrosis and cirrhosis have been described for those conditions in which effective treatment of the causative insult is available. Fibrotic injury is characterised by proliferation and activation of hepatic stellate cells (HSCs), which become the major source of the fibrillar matrix that characterises fibrosis. Thus a prerequisite of resolution is that a net loss of activated HSCs must occur. We have studied a model of spontaneous resolution of liver fibrosis to determine whether apoptosis mediates the loss of HSCs. Livers were harvested from rats during 0, 3, 7, 14 and 28 days of recovery from liver fibrosis induced by CCl4 intra peritoneal (IP) injections for 4 weeks. Histological analysis demonstrated remodelling of the fibrotic septae during the 28 day period of recovery in association with which, the numbers of HSCs determined by alpha-Smooth Muscle Actin (alpha-SMA) staining diminished 12 fold. By standard Haematoxylin and Eosin (H&E) histological staining and after TUNEL staining of representative sections of experimental liver, the first 7 days of recovery were associated with clear evidence of HSC apoptosis. HSCs were isolated from normal rat liver and activated by culture on plastic and serial passage. Cells with an apoptotic morphology were demonstrated on the surface of the monolayer after staining with Acridine Orange, Giemsa and Propidium Iodide. Culture of activated HSCs in serum free media resulted in an increase in the rate of HSC apoptosis.This data confirms that apoptosis is the major mechanism resulting in HSC clearance during recovery from fibrosis. Furthermore they provide evidence that growth factors may increase HSCs numbers during injury by inhibiting apoptosis in addition to promoting proliferation.

The clinical features of systemic mastocytosis have been ascribed to mast cell-dependent mediators, but there have been no studies of their release from isolated cells. We have investigated the release of histamine and eicosanoids from isolated spleen cells obtained from tissue of a mastocytosis patient undergoing therapeutic splenectomy. Dispersed cell preparations contained lymphocytes 65.9%, monocytes/macrophages 22.3%, neutrophils 9.9%, mast cells 1.1%, and eosinophils 0.8%; upon challenge with 0.1-3.0 microM A23187 they released histamine much greater than PGD2 greater than TXB2 greater than LTB4 greater than LTC4 approximately equal to LTD4 greater than LTE4. With immunological activation of passively sensitized cells, histamine and PGD2 release had similar dose-response characteristics, but TXB2, LTC4, LTD4, and LTE4 release differed in reaching maximum at 50 micrograms/ml and declining at 125 micrograms/ml anti-human IgE. Percoll centrifugation separated most of the histamine-containing cells to the middle of the gradient, but they were refractory to release with 0.3 microM A23187 or 50 micrograms/ml anti-IgE. Spontaneous release of histamine from these cells was not abnormally high (1.3%-4.5%). Electron microscopy of tissue sections revealed large numbers of mast cells with empty granules. It is possible that the refractory cells observed are such mast cells where intracellular histamine is no longer granule-associated. Most net histamine and PGD2 release was confined to cells at the bottom of the gradients (1.078-1.09 g/ml), although some release of PGD2 occurred near the top (1.05-1.058 g/ml). There was a significant correlation between the net release of histamine and PGD2 with both immunological (r = 0.92; n = 16) and A23187 (r = 0.97, n = 14) activation. These studies provide evidence for a link between PGD2 and histamine release in mastocytosis spleen cells.