Serum Fragmented Cytokeratin 18 Levels Reflect the Histologic Activity Score of Nonalcoholic Fatty Liver Disease More Accurately Than Serum Alanine Aminotransferase Levels

Background and Goals: Reliable noninvasive biomarkers to assess the histologic activity of nonalcoholic fatty liver disease (NAFLD) have not been established. As the frequency of Mallory bodies is known to be closely associated with the disease severity, we hypothesized that serum levels of Mallory body-related proteins were correlated with NAFLD histologic activity and evaluated this possibility. Study: Serum levels of total and fragmented cytokeratin (CK) 18, heat shock protein (Hsp) 70, Hsp90 alpha, ubiquitin + 1, and p38 alpha at the time of liver biopsy were measured in 118 NAFLD patients and their association with histologic findings and NAFLD histologic activity score (NAS) was investigated. Results: Serum levels of both forms of CK18 and Hsp90 alpha were markedly higher in patients having nonalcoholic steatohepatitis (NASH) compared with non-NASH ones. Both forms of CK18 significantly correlated with degree of steatosis, lobular inflammation, and ballooning, and showed stronger positive correlations with NAS than serum aspartate and alanine aminotransferase (AST and ALT). Multiple regression analysis further revealed that fragmented CK18 and AST were effective predictors of NAS, with the former being the more definitive of the two (P < 0.001 vs. 0.005). In 20 NAFLD patients who received a follow-up biopsy, changes in fragmented CK18 levels, but not AST or ALT levels, closely paralleled those in NAS. Conclusions: These results establish the usefulness of fragmented CK18 measurement for assessing and monitoring the histologic activity of NAFLD.ArticleJOURNAL OF CLINICAL GASTROENTEROLOGY. 44(6):440-447 (2010)journal articl

Role of ASC in the Mouse Model of Helicobacter pylori Infection

Apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) is an adaptor molecule activating caspase-1 that stimulates pro-interleukin-1β (pro-IL-1β) and pro-IL-18, two pro-inflammatory cytokines with critical functions in host defense against a variety of pathogens. In this study, we investigated the role of ASC in the host defense against Helicobacter pylori utilizing ASC-deficient mice. Mice were orally inoculated with H. pylori; bacterial load, degree of gastritis, and mucosal levels of inflammatory cytokines were analyzed and compared with those obtained from wild-type mice. We found more prominent H. pylori colonization in ASC-deficient mice, as revealed by colony-forming unit counts. Both groups of mice developed gastritis; however, ASC-deficient mice showed significant attenuation of inflammation despite high H. pylori colonization. ELISA, immunohistochemistry, and quantitative RT-PCR analyses revealed complete suppression of IL-1β and IL-18, and substantial reduction of interferon-γ (IFN-γ) expression, in ASC-deficient mice without apparent upregulation of other cytokines, including IL-10 and tumor necrosis factor-α. These results as a whole indicate that ASC exerts considerable influence on the host defense, acting through IL-1β/IL-18 and subsequent IFN-γ production, which in turn contributes to continuous chronic inflammatory response and consequent reduction of H. pylori colonization. (J Histochem Cytochem 57:327–338, 2009

Hyperproduction of Hyaluronan in Neu-Induced Mammary Tumor Accelerates Angiogenesis through Stromal Cell Recruitment : Possible Involvement of Versican/PG-M

Elevated concentrations of hyaluronan are often associated with human breast cancer malignancy. Here, we investigated the roles of hyaluronan in carcinogenesis and cancer progression using the mouse mammary tumor virus (MMTV)-Neu transgenic model of spontaneous breast cancer. Conditional transgenic mice that express murine hyaluronan synthase 2 (Has2) by Cre-mediated recombination were generated and crossed with the MMTV-Neu mice. In expressing Cre recombinase under the control of the MMTV promoter, the bigenic mice bearing Has2 and neu transgenes exhibited a deposition of hyaluronan matrix and aggressive growth of Neu-initiated mammary tumors. Notably, forced expression of Has2 impaired intercellular adhesion machinery and elicited cell survival signals in tumor cells. Concurrent with these alterations of tumor cells, intratumoral stroma and microvessels were markedly induced. To reveal the molecular basis of hyaluronan-mediated neovascularization, various hyaluronan samples were examined for their ability to potentiate in vivo angiogenesis. In Matrigel plug assays, basic fibroblast growth factor-induced neovascularization was elevated in the presence of either hyaluronan oligosaccharides or a hyaluronan aggregate containing versican. Administration of hyaluronan-versican aggregates, but not native hyaluronan alone, promoted stromal cell recruitment concurrently with the infiltration of endothelial cells. Taken together, these results suggest that hyaluronan overproduction accelerates tumor angiogenesis through stromal reaction, notably in the presence of versican