Ken-ichiro Mikami

Expression of a 72-kDa heat shock protein, and its cytoprotective function, in gastric mucosa in cirrhotic rats

BackgroundPortal hypertensive gastropathy (PHG) is a clinical entity that is observed frequently in patients with liver cirrhosis. In PHG, gastric mucosa is highly susceptible to mucosal injury caused by noxious agents. Many studies, including ours, have reported that a 72-kDa heat shock protein (HSP72) has a crucial cytoprotective function in gastric mucosa. In this study, we investigated the expression and cytoprotective effect of HSP72 on gastric mucosa in portal hypertensive rats.MethodsPHG was produced by bile duct ligation (BDL) or carbon tetrachloride administration in male Sprague-Dawley rats. The expression of HSP72 in the gastric mucosa was evaluated by Western blotting. Induction of gastric mucosal HSP72 by 6-h water-immersion stress was compared between cirrhotic and control rats. Also, mucosal protective abilities against hydrochloric acid (HCl; 0.6 N) following pretreatment with water-immersion stress to induce HSP72 were studied in both groups.ResultsPortal venous pressure was significantly higher in cirrhotic rats compared with control rats (P < 0.05). Baseline expression (before water-immersion stress) of mucosal HSP72 was significantly lower in cirrhotic rats compared with control rats. HCl-induced gastric mucosal lesions were significantly suppressed in control rats compared with cirrhotic rats, especially when HSP72 was preinduced by water-immersion stress.ConclusionsThese findings suggest that HSP72 in the gastric mucosa plays a crucial role with respect to cytoprotection; the induction of HSP72 may provide therapeutic strategies for protection against mucosal injury in PHG.

Zinc L-carnosine protects against mucosal injury in portal hypertensive gastropathy through induction of heat shock protein 72

Background and Aims:  Increased susceptibility to gastric mucosal injury is observed in portal hypertensive gastropathy (PHG). In this study, the effects of zinc L‐carnosine, an anti‐ulcer drug, were evaluated on expression of heat shock protein (hsp) 72 and cytoprotection in gastric mucosa in a rat model of PHG.

Induction of a 72-kDa heat shock protein and protection against lipopolysaccharide-induced liver injury in cirrhotic rats

Background and Aim:  A 70‐kDa heat shock protein (stress‐inducible HSP70, HSP72) has been reported to be a cytoprotectant in a variety of organs. It has been reported that HSP72 protected non‐cirrhotic rats against endotoxemia. However, its cytoprotective effect against endotoxemia in cirrhotic rats has not yet been studied. In this study, we investigated the cytoprotective effect of HSP72 on lipopolysaccharide (LPS)‐induced liver injury in carbon tetrachloride (CCl4)‐induced cirrhotic rats.

Gabexate mesilate, a synthetic protease inhibitor, attenuates carbon tetrachloride-induced liver injury in rats.

BackgroundGabexate mesilate, a synthetic protease inhibitor, is used to treat acute pancreatitis and disseminated intravascular coagulation because it inhibits various serine proteases; however, whether gabexate mesilate prevents acute liver failure has not yet been studied. The aim of the present study was to investigate the effect of gabexate mesilate in carbon tetrachloride (CCl4)-induced liver injury in rats.MethodsAcute hepatic failure was induced by administration of CCl4 intragastrically to male Sprague–Dawley rats. The effects of gabexate mesilate were examined in terms of serum transaminase levels, liver histology, and the prognosis of rats.ResultsGabexate mesilate treatment significantly decreased the elevation of serum transaminase levels and improved liver histology 24 h after the administration of CCl4 (0.2 ml/100 g rat weight). Plasma tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) decreased significantly in the gabexate mesilate-treated rats compared with saline-treated rats. Gabexate mesilate treatment also significantly improved survival rate after a lethal dose of CCl4 (0.5 ml/100 g rat weight) from 0% to 20%.ConclusionsGabexate mesilate treatment attenuated CCl4-induced liver injury via a suppression of proinflammatory cytokine production. In addition, these investigations suggest that gabexate mesilate treatment may provide therapeutic strategies for human acute liver failure.

Alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 19-9-producing gallbladder cancer

We report a rare case of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19-9-producing gallbladder cancer with high levels of CA125 and protein induced by vitamin K absence or antagonist II (PIVKA II). A 63-year-old man was diagnosed with gallbladder cancer with metastases to the liver, based on ultrasonography and computed tomography of the abdomen showing multiple tumorous lesions in the liver and a thickened gallbladder wall. Laboratory data showed high levels of tumor markers: 4647.4 ng/ml AFP, 9987.1 ng/ml CEA, 11704.0 U/ml CA19-9, 847.6 U/ml CA125, and 0.2 AU/ml PIVKA II. AFP in the present case showed an increase in Concanavalin A-nonbinding fraction and an increase inLens culinaris lectin-binding fraction by affinity column chromatography. The patient died of hepatic failure. Autopsy revealed gallbladder cancer consisting of papillary adenocarcinoma and moderately differentiated tubular adenocarcinoma. By immunohistochemical staining, AFP was detected in the papillary adenocarcinoma portion of the primary focus and metastatic tumor cells in the liver, but was not detected in noncancerous liver tissue. CEA and CA19-9 were detected mainly in the tubular adenocarcinoma portion.

Distribution and isoforms of epimorphin in carbon tetrachloride-induced acute liver injury in mice.

Background and Aim:  Epimorphin, a morphoregulatory factor essential to organ development, is believed to direct normal morphogenesis in tissue repair. We examined the dynamics and the roles of epimorphin, a cell surface‐associated molecule detected on mesenchymal cells, in hepatic tissue repair from acute liver injury.

Tauroursodeoxycholic acid enhances phagocytosis of the cultured rat Kupffer cell

Background: Ursodeoxycholic acid is used in the treatment of acute and chronic intrahepatic cholestasis because it ameliorates cholestasis and protects hepatocytes. However, few studies have examined the effect of bile acids on the function of Kupffer cells.

Clinical significance of SEN-virus on interferon response in chronic hepatitis C patients.

Background and Aim:  A novel virus, SEN‐virus (SENV), was recently discovered. It has been reported as a candidate for a non‐A–E hepatitis virus. However, much is still unknown about the clinical significance of SENV. The aim of the present study was to clarify the clinical significance of SENV in patients coinfected with SENV and hepatitis C virus (HCV).

Effects of acetaldehyde on microtubules and hepatic kinesin:a study of the pathogenesis of alcoholic liver disease

Abstract In ballooned hepatocytes associated with alcoholic liver disease, secretory proteins are abundant, possibly due to an impairment of the microtubule-dependent vesicular transport system. We studied the effects of ethanol and acetaldehyde on microtubules and hepatic kinesin function. Tubulin and microtubule-associated protein 2 was purified by phosphocellulose and hydroxyapatite column chromatography from microtubule proteins of bovine brain. Hepatic kinesin was purified from rabbit liver. The assembly of microtubules was quantified by spectro-photometer. The kinesin motility assay is done with or without various concentrations of ethanol or acetaldehyde using video-enhanced differential interference contrast microscopy. Ethanol had no effect on the assembly or disassembly of the microtubules or on hepatic kinesin function, even at high concentrations of up to 100 mM. In contrast, acetaldehyde reduced hepatic kinesin function at concentrations greater than or equal to 100 μ M and induced microtubular disassembly at concentrations greater than or equal to 200 μ M. In alcoholic liver injury, chronic reduction of hepatic kinesin function may cause retention of secretory proteins and hepatocyte swelling. Moreover, reduction of the microtubule concentrations due to acetaldehyde may further impair the vesicular transport system and reduce the cells ability to maintain morphology, in turn accelerating hepatocyte ballooning.

Effect of dibutyryl cyclic AMP on phagocytosis and production of nitric oxide and tumor necrosis factor-α in cultured rat Kupffer cells

Abstract Dibutyryl cyclic AMP (DBcAMP) is an analogue of cAMP. DBcAMP has many effects on hepatocellular carcinoma, liver cirrhosis, ischemic liver failure and endotoxin-induced inflammatory liver injury. However, little is known about the mechanism of DBcAMP action in Kupffer cells. We examined the effects of DBcAMP on phagocytic activity and production of nitric oxide (NO) and tumor necrosis factor- α (TNF- α ) in cultured rat Kupffer cells treated with lipopolysaccharide (LPS). NO concentrations in culture supernatants were measured using an NO analyzer and TNF- α levels were measured with ELISA. Immunofluorescent staining for nuclear factor- κ B (NF- κ B) was visualized using an anti-NF- κ B p65 antibody. DBcAMP premedication had no effect on LPS-stimulated phagocytic activity of Kupffer cells but increased NO production and inhibited TNF- α production in a dose-dependent manner. Genistein did not block, but H-89 did block, the inhibitory effect of DBcAMP on LPS-stimulated TNF- α production in Kupffer cells. We conclude that DBcAMP inhibits LPS-stimulated TNF- α production by activating cyclic AMP-dependent protein kinase. Using immunofluorescent staining for NF- κ B, we demonstrate that the effect of DBcAMP does not involve signal transduction through NF- κ B.