Downregulation of the Wnt antagonist Dkk2 links the loss of Sept4 and myofibroblastic transformation of hepatic stellate cells.

BACKGROUND/AIMS: Sept4, a subunit of the septin cytoskeleton specifically expressed in quiescent hepatic stellate cells (HSCs), is downregulated through transdifferentiation to fibrogenic and contractile myofibroblastic cells. Since Sept4(-/-)mice are prone to liver fibrosis, we aimed to identify the unknown molecular network underlying liver fibrosis by probing the association between loss of Sept4 and accelerated transdifferentiation of HSCs. METHODS: We compared the transcriptomes of Sept4(+/+) and Sept4(-/-) HSCs undergoing transdifferentiation by DNA microarray and quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. Because Dickkopf2 (Dkk2) gene expression is reduced in Sept4(-/-) HSCs, we tested whether supplementing Dkk2 could suppress myofibroblastic transformation of Sept4(-/-) HSCs. We tested the involvement of the canonical Wnt pathway in this process by using a lymphoid enhancer-binding factor/transcription factor-luciferase reporter assay. RESULTS: We observed consistent upregulation of Dkk2 in primary cultured HSCs and in a carbon tetrachloride liver fibrosis in mice, which was decreased in the absence of Sept4. Supplementation with Dkk2 suppressed the induction of pro-fibrotic genes (α-smooth muscle actin and 2 collagen genes) and induced an anti-fibrotic gene (Smad7) in Sept4(-/-) HSCs. In human liver specimens with inflammation and fibrosis, Dkk2 immunoreactivity appeared to be positively correlated with the degree of fibrotic changes. CONCLUSIONS: Pro-fibrotic transformation of HSCs through the loss of Sept4 is, in part, due to reduced expression of Dkk2 and its homologues, and the resulting disinhibition of the canonical Wnt pathway.

Olprinone attenuates excessive shear stress through up-regulation of endothelial nitric oxide synthase in a rat excessive hepatectomy model.

After extended hepatectomy, excessive shear stress in the remnant liver causes postoperative liver failure. Olprinone (OLP), a selective phosphodiesterase inhibitor, has been reported to improve microcirculation and attenuate inflammation. The aim of this study was to investigate the effects of OLP on shear stress in rats with an excessive hepatectomy (EHx) model. In this study, EHx comprised 90% hepatectomy with ligation of the left and right Glisson's sheaths in Lewis rats. OLP or saline was intraperitoneally administered with an osmotic pump 48 hours before EHx. To evaluate the shear stress, we measured the portal vein (PV) pressure. We also assessed sinusoidal endothelial cell injury by immunohistochemistry and electron microscopy. Furthermore, we assessed apoptosis in the liver with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method. Treatment with OLP up-regulated hepatic endothelial nitric oxide synthase (eNOS) expression. The increase in the PV pressure due to Glisson's sheath ligation was attenuated in OLP-treated rats during a 30-minute period after ligation. Treatment with OLP preserved sinusoidal endothelial cells and reduced apoptosis in the remnant liver. The probability of survival in the OLP-treated rats was significantly better than that in the controls (33.3% versus 13.3%). Furthermore, the postoperative eNOS activity in the OLP-treated rats was higher than that in the controls. The administration of Nω-nitro-l-arginine methyl ester to OLP-treated rats eliminated the effects of OLP on PV pressure and survival after EHx. Therefore, we concluded that OLP attenuates excessive shear stress through the up-regulation of eNOS and improves the survival rate after EHx.

Resistance to cisplatin-induced apoptosis via PI3K-dependent survivin expression in a rat hepatoma cell line.

Hepatocellular carcinoma (HCC) is known to be resistant to chemotherapy. Survivin, a member of the inhibitor of apoptosis proteins, is overexpressed in most cancers but is absent in most normal adult tissue. The aim of this study was to investigate whether expression of survivin contributes to resistance to cisplatin-induced apoptosis. We confirmed induction of survivin expression in hepatoma in the N-diethylnitrosamine (DEN) induced rat and in the rat hepatoma cell line (K-251). We examined cell proliferation after treatment with cisplatin (CDDP) in the presence and absence of siRNA or the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 to suppress survivin or PI3K/Akt, respectively. Survivin was expressed in DEN-induced rat HCC with RT-PCR and Western blotting. Expression of survivin was observed primary in the nuclei and in the cytoplasm with immunohistochemistry. However, survivin was not detected in non-tumor tissues. Expression of survivin was also observed primarily in the nuclei and in the cytoplasm of the K-251 rat hepatoma cell line. CDDP induced survivin expression, which was blocked by siRNA. LY294002 also attenuated survivin expression induced by CDDP. Our results indicate that survivin expression via PI3K contributes to resistance to CDDP-induced apoptosis in a rat hepatoma cell line.

Dai-kenchu-to attenuates rat sinusoidal obstruction syndrome by inhibiting the accumulation of neutrophils in the liver.

BACKGROUND AND AIM: Sinusoidal obstruction syndrome (SOS) is drug-induced liver injury that occurs in patients who receive hematopoietic cell transplantation and oxaliplatin-contained chemotherapy. The aim of study was to investigate the pharmacological treatment of SOS using a traditional Japanese medicine, Dai-kenchu-to (DKT). METHODS: Male Sprague-Dawley rats were treated with monocrotaline (MCT) to induce SOS. The rats were divided into three groups: control, MCT and MCT+DKT groups. In the MCT+DKT group, DKT was gavaged at 12 h after MCT treatment and given every 12 h until the end of the protocol. The rats of MCT group were treated with water instead of DKT. At 48 h after MCT treatment, blood and liver samples were collected. RESULTS: In the MCT+DKT group, the macroscopic and histological findings revealed liver congestion, sinusoidal alteration and the destruction of sinusoidal lining, which were comparable with those of the MCT group. However, the area of hepatic necrosis and serum AST levels significantly decreased in the MCT+DKT group compared with those of the MCT group. Treatment with DKT resulted in the reduction of neutrophil accumulation, myeloperoxidase activity and the expression of cytokine-induced neutrophil chemoattractant (CINC) and intracellular adhesion molecule-1 (ICAM-1) mRNA in the liver compared with those of the MCT group. Treatment with processed ginger, one of the ingredients in DKT, resulted in similar effects to those shown by DKT. CONCLUSIONS: Dai-kenchu-to attenuates MCT-induced liver injury by preventing neutrophil-induced liver injury through blockage of upregulation of CINC and ICAM-1 mRNA level.

Inhibition of c-Jun NH2-terminal kinase switches Smad3 signaling from oncogenesis to tumor- suppression in rat hepatocellular carcinoma.

UNLABELLED: Transforming growth factor beta (TGF-beta) signaling involves both tumor-suppression and oncogenesis. TGF-beta activates the TGF-beta type I receptor (TbetaRI) and c-Jun N-terminal kinase (JNK), which differentially phosphorylate the mediator Smad3 to become COOH-terminally phosphorylated Smad3 (pSmad3C) and linker-phosphorylated Smad3 (pSmad3L). TbetaRI-dependent pSmad3C transmits a tumor-suppressive TGF-beta signal, while JNK-dependent pSmad3L promotes carcinogenesis in human chronic liver disorders. The aim of this study is to elucidate how SP600125, a JNK inhibitor, affected rat hepatocellular carcinoma (HCC) development, while focusing on the domain-specific phosphorylation of Smad3. The rats received subcutaneous injections of either SP600125 or vehicle 11 times weekly together with 100 ppm N-diethylnitrosamine (DEN) administration for 56 days and were sacrificed in order to evaluate HCC development 28 days after the last DEN administration. The number of tumor nodules greater than 3 mm in diameter and the liver weight/body weight ratio were significantly lower in the SP600125-treated rats than those in the vehicle-treated rats (7.9 +/- 0.8 versus 17.7 +/- 0.9: P < 0.001; 6.3 +/- 1.2 versus 7.1 +/- 0.2%: P < 0.05). SP600125 significantly prolonged the median survival time in rats with DEN-induced HCC (113 versus 97 days: log-rank P = 0.0018). JNK/pSmad3L/c-Myc was enhanced in the rat hepatocytes exposed to DEN. However, TbetaRI/pSmad3C/p21(WAF1) was impaired as DEN-induced HCC developed and progressed. The specific inhibition of JNK activity by SP600125 suppressed pSmad3L/c-Myc in the damaged hepatocytes and enhanced pSmad3C/p21(WAF1), acting as a tumor suppressor in normal hepatocytes. CONCLUSION: Administration of SP600125 to DEN-treated rats shifted hepatocytic Smad3-mediated signal from oncogenesis to tumor suppression, thus suggesting that JNK could be a therapeutic target of human HCC development and progression.

A phosphodiesterase III inhibitor protects rat liver from sinusoidal obstruction syndrome through heme oxygenase-1 induction.

OBJECTIVE: The aim of study was to investigate pharmacological treatment for sinusoidal obstruction syndrome (SOS). BACKGROUND: SOS is associated with oxaliplatin-based chemotherapy in patients with hepatic colorectal metastases. Patients with SOS have increased postoperative morbidity after major hepatectomy, but a method for effective prevention of SOS has not been established. METHODS: Male Sprague-Dawley rats were treated with cobalt protoporphyrin IX (CoPP) or olprinone (OLP), a phosphodiesterase III inhibitor, and hepatic HO-1 expression and HO enzymatic activity were determined. Monocrotaline (MCT) was given to rats to induce SOS, and blockage of SOS by CoPP or OLP-induced hepatic HO-1 was examined in these rats. Zinc protoporphyrin IX (ZnPP), a competitive HO inhibitor, was given to MCT-treated rats together with OLP to clarify the mechanism of protection against SOS. We also examined if OLP preserved remnant liver function after 70% hepatectomy in MCT-treated rats. RESULTS: OLP up-regulated hepatic HO-1 protein expression and HO enzymatic activity, and activated Akt protein. Administration of ZnPP to OLP-treated rats resulted in inhibition of HO activity and inactivation of Akt. Induction of HO-1 by pretreatment with CoPP led to amelioration of SOS in histologic findings and blockage of elevation of serum liver enzymes. Pretreatment with OLP gave a similar result and preserved remnant liver function, as indicated by improved survival after hepatectomy. ZnPP completely abolished the protective effects of OLP. CONCLUSIONS: Protection of the liver from drug-induced injury by prior up-regulation of HO-1 using OLP may have potential as a therapeutic strategy for prevention of SOS.

Prophylactic respiratory management after liver resection with bilevel positive airway pressure ventilation: Report of three cases.

Pulmonary complications after hepatectomy occur with relative frequency and are associated with increased morbidity and mortality. Moreover, their prevention is often difficult. We report using prophylactic bilevel positive airway pressure ventilation, initiated just after the operation, for the successful postoperative respiratory management of three patients predisposed to the development of pulmonary complications. One patient had insufficient pulmonary function (forced expiratory volume in 1 s (FEV(1)) 0.95 l; FEV(1)/forced vital capacity 40.8%) caused by previous thoracoplasty. The other two patients were obese and had obstructive sleep apnea syndrome (OSAS). None of the patients required endotracheal intubation after hepatectomy, although the two with severe OSAS suffered pulmonary thromboembolism postoperatively. Bilevel positive airway pressure ventilation was well tolerated and there were no adverse effects, suggesting its effectiveness for preventing pulmonary complications after hepatectomy.

[Retrospective analysis of clinical results in eight patients with advanced hepatocellular carcinoma with lung metastases treated by TS-1].

Advanced hepatocellular carcinoma (HCC) with distant metastases, in particular to the lung, has a poor prognosis. This study was undertaken to evaluate the effectiveness of TS-1 as chemotherapy in advanced HCC with lung metastases. Between January 2004 and October 2005, 8 patients with advanced HCC with lung metastasis were enrolled. All patients received systemic chemotherapy with TS-1. The drug was administered at a dose of 80 mg/m(2)/day for four weeks, followed by a two-week rest, repeated every six weeks until disease progression, unacceptable toxicity, or the patient's refusal. Median age of the patients was 59 years (range, 44 to 79 years). All patients were in Child-Pugh class A. A total of 22 cycles were administered to each patient (range, 1 to 5). No complete or partial responses were observed. There were two patients (25%) with decreasing tumor marker. Median progression-free survival was 79.5 days (range, 29 to 225). The median overall survival was 257 days (95% confidence interval, 191 to 323 days). TS-1 as chemotherapy was well tolerated when administered in the schedule used in this study. Some patients achieved stable disease and clinical benefits, though this regimen has limited activity in HCC with lung metastases. Randomized controlled trials are necessary to clarify survival benefits in patients with advanced HCC with lung metastasis.