Visceral fat predominance is associated with non-alcoholic fatty liver disease in Japanese women with metabolic syndrome.

AIM: Metabolic syndrome (MS) is likely to be associated with non-alcoholic fatty liver disease (NAFLD). The prevalence of NAFLD in visceral fat type MS (V-type MS) is known to be higher than in subcutaneous fat type MS (S-type MS) in men with MS, and a larger subcutaneous fat area is reported to be not associated with NAFLD in women. We elucidated differences between V-type S-type MS in Japanese women with MS. METHODS: The subjects were 276 women with MS who underwent a medical checkup including abdominal ultrasonography. We examined for the prevalence of fatty liver and investigated biochemical parameters, and we also made a distinction between V-type and S-type MS. RESULTS: Triglyceride, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase, the frequency of fatty liver and impaired glucose tolerance (IGT) were significantly higher in V-type MS than in S-type MS. On logistic regression analysis with NAFLD (in our study, fatty liver with ALT ≥31 IU/L was defined as NAFLD) as a dependent variable, body mass index, dyslipidemia, AST and V-type MS were significant predictors of an increased prevalence of NAFLD (odds ratios [OR] = 18.85, 3.119, 59.77 and 3.205; 95% confidence intervals [CI] = 3.585-99.15, 1.195-8.142, 18.03-198.2 and 1.198-8.573; P < 0.001, <0.05, <0.001 and <0.05, respectively). CONCLUSION: Women with V-type MS are more likely to have fatty liver, IGT and liver dysfunction than those with S-type MS. V-type MS is one of the significant predictors for NAFLD in Japanese women with MS.

Hemoperfusion with a high-mobility group box 1 adsorption column can prevent the occurrence of hepatic ischemia-reperfusion injury in rats.

OBJECTIVE: High-mobility group box 1, a ubiquitous nonhistone chromosomal protein, is passively released from necrotic cells and actively secreted by inflammatory cells. Extracellular high-mobility group box 1 has recently been recognized to be a mediator of hepatic ischemia-reperfusion injury; however, the kinetics of high-mobility group box 1 during hepatic ischemia-reperfusion and the role of high-mobility group box 1 in ischemia-reperfusion injury still remain poorly understood. This study was designed to assess the localization and the kinetics of high-mobility group box 1 during hepatic ischemia-reperfusion injury and the effects of high-mobility group box 1 adsorption column in hepatic ischemia-reperfusion injury. DESIGN: A prospective, randomized animal study. SETTING: University medical center research laboratory. SUBJECTS: Male Sprague-Dawley rats. INVESTIGATION: The animals underwent 70% partial hepatic ischemia for 60 or 90 mins and were then reperfused. To investigate the high-mobility group box 1 levels in the serum and in the liver, the animals were killed at predetermined periods. As a lethal model, global hepatic ischemia-reperfusion was induced by portal triad cross-clamping for 30 mins. Hemoperfusion therapy using a cellulofine sulfate bead column (high-mobility group box 1 adsorption column) was performed during global hepatic ischemia. MEASUREMENTS AND MAIN RESULTS: During 60 mins of 70% hepatic ischemia, nuclear high-mobility group box 1 was translocated to the cytoplasm in hepatocytes; however, serum high-mobility group box 1was not increased. Immediately after reperfusion, the serum high-mobility group box 1 was significantly increased (p < .05). High-mobility group box 1 mediated ischemia-reperfusion injury in not only liver but also the remote organ, lung. Removal of excess high-mobility group box 1 in blood using an adsorption column significantly improved animal survival (p < .03) and liver and lung injuries. CONCLUSIONS: High-mobility group box 1 plays an important role in the systemic as well as local pathogenesis of hepatic ischemia-reperfusion injury. The removal of excessive high-mobility group box 1 with adsorption column was beneficial and promising option in ischemia-related liver injuries.

Increased expression of fractalkine is correlated with a better prognosis and an increased number of both CD8+ T cells and natural killer cells in gastric adenocarcinoma.

BACKGROUND: Fractalkine (CX3CL1) is the only CX3C chemokine that can chemoattract natural killer (NK) cells, CD8+ T cells, monocytes, and dendritic cells. Although experimental studies have demonstrated that Fractalkine expression by tumor cells is related to the infiltrating lymphocytes and initiates antitumor immunity, the clinical significance of Fractalkine remains to be elucidated in gastric adenocarcinoma. METHODS: Tissue sections from 158 patients with curatively resected T2 or T3 gastric adenocarcinoma were immunohistochemically stained for Fractalkine. Furthermore, to evaluate CD8+ T cells and NK cells infiltration, antibodies to CD8 and CD57 protein were respectively used for immunohistochemistry. RESULTS: A significant direct correlation was observed between the Fractalkine scores and the number of CD8+ T cells and NK cells using the Spearman rank correlation coefficient test (P = .0080, .0031, respectively). Furthermore, the high Fractalkine expression group (n = 67) showed a significantly better prognosis than the low Fractalkine expression group (n = 91) regarding the disease-free survival (P = .0016). In a multivariate analysis, the Fractalkine expression was identified as one of the independent prognosticators for disease-free survival (risk ratio, 2.5; P = .0147). CONCLUSIONS: These data suggest that the expression of Fractalkine by tumor cells enhances the recruitment of CD8+ T cells and NK cells and induces both innate and adaptive immunity, thereby yielding a better prognosis in gastric adenocarcinoma. Fractalkine is a new independent predictor of the prognosis and can be a novel candidate for development of a more effective therapeutic strategy for gastric adenocarcinomas.

Role of peroxisome proliferator-activated receptor-gamma (PPARgamma) during liver regeneration in rats.

BACKGROUND AND AIM: Peroxisome proliferator-activated receptor-gamma (PPARgamma), a member of the nuclear receptor superfamily, is widely expressed in adipocytes and other tissues, including the liver. Several reports have shown that PPARgamma activation induced cell-cycle arrest and apoptosis in tumor cells. We investigated the role of the PPARgamma/ligand system and the effect of the PPARgamma agonist during liver regeneration. METHODS: Expression of PPARgamma and serum levels of 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) by enzyme immunoassay were evaluated in rats following partial hepatectomy (PH group). Further, the effect of the PPARgamma agonist, pioglitazone, on liver regeneration (PH + PGZ group) was evaluated by proliferating cell nuclear antigen labeling index, relative liver weight, and expression of cell-cycle regulators. RESULTS: The number of PPARgamma-stained hepatocytes decreased at 24 h (PH, 15.8 +/- 2.2%; sham, 35.5 +/- 2.4%; P < 0.001) and increased in the late phase of liver regeneration compared to the sham-operated group (P < 0.001 at 48-120 h). The peaks of serum 15d-PGJ2 (627.0 +/- 91.1 pg/ml) and PPARgamma expression (90.6 +/- 3.1%) coincided in the late phase of liver regeneration. Also, oral administration of pioglitazone inhibited hepatocyte proliferation, in terms of the proliferating cell nuclear antigen (PCNA) labeling index and p27 expression during the late phase of liver regeneration, and caused a transient reduction in liver mass when compared to the PH group. CONCLUSIONS: These results indicate that the PPARgamma/ligand system may be one of the key negative regulators of hepatocyte proliferation and may be responsible for the inhibition of liver growth in the late phase of liver regeneration.

A resected case of liver metastasis from colon cancer that occurred 13 years after a colectomy.

A 73-year-old man, who underwent a potentially curative resection of cancer of the descending colon 13 years before, was found to have a well-defined hepatic tumor on ultrasonography. A lateral segmentectomy was performed for a solitary hepatic tumor. Histopathological examination of the tumor indicated well differentiated adenocarcinoma compatible with the metastasis from the previous descending colon cancer. There have been no signs of recurrence for 5 years after the hepatic resection. This case suggests that distant metastasis from colorectal could be found several years after operation like in this case, and consequently long-term and strict follow-up is required after curative resection of the primary lesion.

Our experiences in surgical treatment for hilar cholangiocarcinoma.

BACKGROUND/AIMS: Although resection for hilar cholangiocarcinoma usually requires difficult surgical manipulations, it is only one therapeutic modality for a permanent cure or a desirable prognosis. We verified our own experiences after surgical treatment for hilar cholangiocarcinoma. METHODOLOGY: This study included 24 patients with hilar cholangiocarcinoma from 1981 to 2002. The current study mainly evaluated postoperative complications and overall prognosis after resection. RESULTS: Twenty-one patients received tumor resection. Hepatic resection including extended hepatectomy was required in 19 patients (90.5%). Postoperative morbidity was observed in 16 (71.2%), and motality in 2 (9.5%). The overall 5-year survival rate was 33.7%, and median survival was 35.7 months. Tumor extent in the TNM stage (p = 0.011) and the existence of lymph node metastases (p = 0.038) were identified as significant prognostic factors in overall survival after operation by univariate analysis. Postoperative adjuvant radio-chemotherapy after resection improved their prognosis (p = 0.010). CONCLUSIONS: Our results suggest that aggressive resection and appropriate adjuvant therapies for hilar cholangiocarcinoma might make a better prognosis possible, especially in patients without lymph node metastases excluding advanced tumor.

Expression of gap junction protein connexin32 in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma.

BACKGROUND: The gap junction (GJ) plays important roles in the maintenance of tissue homeostasis, the control of cell growth and differentiation, and the prevention of experimental hepatocarcinogenesis. In this study, we examined the relationship between the expression of the GJ protein connexin (Cx) 32 in 24 human hepatocellular carcinomas (HCCs) and 29 non-carcinomatous liver specimens (NCLs) of 31 patients. METHODS: An immunohistochemical study of Cx32 was done in 24 HCCs and 29 NCLs from 31 patients who had undergone hepatic resection. RESULTS: The Cx32 expression decreased gradually as the disease progressed to cirrhosis and HCC. In all Cx32 positive HCCs, the expression was mostly recognized in cytoplasm, not only on the cell membrane. This internalization of Cx32 was also recognized in liver specimens showing hepatitis and cirrhosis, although it was less frequent than in the HCCs. CONCLUSIONS: These findings suggest the possibility that changes in both the amount and the distribution of Cx32 may be implicated in human hepatocarcinogenesis.

Requisite role of VEGF receptors in angiogenesis of hepatocellular carcinoma: a comparison with angiopoietin/Tie pathway.

BACKGROUND: Tumor vascularity is an independent predictor of prognosis in HCC patients, however, the growth factors governing the angiogenesis remain obscure. MATERIALS AND METHODS: Multiple mRNA species of angiogenesis-related growth factors/receptors and CD31 were evaluated in 38 hepatocellular carcinomas (HCCs) and surrounding livers (SL) by a highly sensitive RNase protection assay. RESULTS: Significant increases in VEGF, VEGFR3, endoglin and CD31 mRNA expressions were noted in HCC rather than in SL. Only VEGFR1 had significant correlation with CD31 expression. VEGFRs and CD31 overexpressed in tumors with portal vein invasion and only VEGFR3- and CD31-positive patients had significantly shorter disease-free survival. Tie1 and Tie2 were overexpressed in large HCCs. The VEGF and Tie receptors expressed differentially in 28 tumors. CONCLUSION: The VEGF receptors might play the major role in HCC angiogenesis and prognosis. The differential expression of receptors might prove valuable in selected subsets of patients for tailored antiangiogenic therapy in HCC patients.

Sequential changes of connexin32 and connexin26 in ischemia-reperfusion of the liver in rats.

Serial changes in expression of hepatic gap junction components, connexin32 and connexin26 expressions during ischemia (60 min)-reperfusion injury of the liver were evaluated by immunofluorescence staining and reverse transcription-polymerase chain reaction in rats. Hepatic tissue calcium content and liver enzymes (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase), were also examined. Connexin expressions were down-regulated during ischemia and steeply increased during the early reperfusion period. This upsurge in connexin was coincided with the augmentation in tissue calcium content level. And the mRNA levels of connexin changed in parallel with the connexin protein level until 60 min after reperfusion. Since it is known that the changes in intracellular Ca(2+) concentration controls the intercellular communication via gap junction, these findings suggest the possibility that gap junction may play a definitive role in reperfusion injury of the liver. Further studies may be necessary to clarify the exact role of connexins in hepatic ischemia-reperfusion injury.

Subtypes of metabolic syndrome and of other risk factors in Japanese women with erosive esophagitis.

Obesity and metabolic syndrome (MS) are strongly associated with erosive esophagitis (EE). The prevalence of MS and EE, and the distribution of adipose tissue have been known to differ markedly between men and women. Although the prevalence of EE in men with MS is known to be higher in visceral fat type MS (V-type MS) than in subcutaneous fat type MS (S-type MS), the association between EE and the types of MS in women with MS is unclear. This study was a cross-sectional study elucidating the association between EE and the types of MS in women with MS. Subjects were 454 women with MS who underwent a regular health check-up. A distinction was made between V-type MS and S-type MS and the prevalence of EE and the association between EE and other data were elucidated. Although there were some significant different factors in characteristics between V-type MS and S-type MS, there was no significant difference in the prevalence of EE between V-type MS and S-type MS. The presence of Helicobacter pylori (H. pylori) was significantly lower than in subjects with EE (13.7%) than in subjects without EE (41.9%). The frequency of hiatal hernia was significantly higher in subjects with EE (60.8%) than in subjects without EE (24.6%). Logistic regression analysis showed hiatal hernia (odds ratio: 4.673; 95% confidence interval: 2.448-8.920; P<0.001), hemoglobin A1c (HbA1c) (2.325; 1.110-4.870; P<0.05), and the presence of H. pylori (0.239; 0.101-0.567; P<0.005) were significant predictors of the prevalence of EE. V-type MS may not be such an important factor for the prevalence of EE in women with MS as in men with MS. The absence of H. pylori, hiatal hernia, and HbA1c may be more important for the prevalence of EE than the types of MS in women with MS.

Visceral fat predominance is associated with erosive esophagitis in Japanese men with metabolic syndrome.

BACKGROUND AND AIM: Although visceral fat is strongly associated with metabolic syndrome (MS), the association between erosive esophagitis (EE) and visceral and subcutaneous fat types in individuals with MS has remained unclear. In this study, we divided individuals with MS into those with visceral and subcutaneous fat types, and determined the differences in the presence of EE between the types of MS in Japanese men. METHODS: The participants were 265 men with MS who underwent a medical checkup including upper gastrointestinal endoscopy and abdominal ultrasonography. We made a distinction between visceral and subcutaneous fat types of MS by ultrasonography, and examined for the presence of EE, and the correlation between EE and other data. RESULTS: Total cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, and the frequency of EE were significantly higher in visceral fat-type MS than in subcutaneous fat-type MS. On logistic regression analysis with EE as a dependent variable and the significant background factors as the independent variables, visceral fat-type MS and hiatal hernia were significant predictors of an increased prevalence of EE (odds ratios=3.808 and 8.599; 95% confidence intervals=1.710-8.479 and 4.206-17.58; P<0.005 and <0.001, respectively). CONCLUSION: Japanese men with visceral fat-type MS are more likely to have dyslipidemia and EE than those with subcutaneous fat-type MS. Visceral fat-type MS is one of the most significant predictors of an increased prevalence of EE in Japanese men with MS.

Usefulness of differentiating metabolic syndrome into visceral fat type and subcutaneous fat type using ultrasonography in Japanese males.

BACKGROUND: Although metabolic syndrome (MS) is likely to be associated with nonalcoholic fatty liver disease (NAFLD), visceral fat type MS and subcutaneous fat type MS have not been distinguished. In this study, we divided persons with MS into those with visceral and subcutaneous fat types by ultrasonography (US), and elucidated differences between these types of MS in Japanese males. METHODS: The subjects were 628 males with MS who underwent a medical checkup including abdominal US. We examined for the presence of fatty liver and investigated biochemical parameters, and we also made a distinction between visceral and subcutaneous fat types of MS by US. RESULTS: Total cholesterol (T-CHO), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the frequency of fatty liver were significantly higher in visceral fat type MS than in subcutaneous fat type MS. On logistic regression analysis with NAFLD (in our study, fatty liver with ALT ≥31 IU/l was defined as NAFLD) as a dependent variable, the age, body mass index (BMI), AST, and visceral fat type MS were significant risk factors for NAFLD. BMI, AST, and visceral fat type MS were predictors of an increased prevalence of NAFLD [odds ratios (ORs) = 1.903, 12.06, and 2.617; 95% confidence intervals (CIs) = 1.122-3.228, 7.053-20.61, and 1.741-3.935; p = 0.017, <0.001, and <0.001, respectively). CONCLUSIONS: Japanese males with visceral fat type MS are more likely to have dyslipidemia, fatty liver, and liver dysfunction than those with subcutaneous fat type MS. Visceral fat type MS is one of the most significant risk factors for NAFLD in Japanese males with MS.

Reconstruction of the gastrointestinal tract by hemi-double stapling method for the esophagus and jejunum using EEA OrVil in laparoscopic total gastrectomy and proximal gastrectomy.

We report the method of anastomosis based on a hemi-double stapling technique (hereinafter, HDST) using a trans-oral anvil delivery system (EEA OrVil) for reconstructing the esophagus and lifted jejunum following laparoscopic total gastrectomy or proximal gastric resection. As a basic technique, end-to-side anastomosis was used for the cut-off stump of the esophagus and lifted jejunum. After the gastric lymph node dissection, the esophagus was cut off obliquely to the long axis using an automated stapler. EEA OrVil was orally, and a small hole was created at the tip of the obliquely cut-off stump with scissors to let the valve tip pass through. When it was confirmed that the automated stapler and center rod were made completely linear, the anvil and the main unit were connected with each other and firing was carried out. Then, HDST-based anastomosis was completed. The method may safe laparoscopic anastomosis between the esophagus and reconstructed intestine.

Experimental investigation of the role of endothelin-1 in idiopathic portal hypertension.

BACKGROUND AND AIM: The authors' previous report revealed that endothelin-1 might be released from B lymphocytes in cirrhotic patients with hypersplenism. Other investigators have shown that persistent exposure to environmental contaminants including arsenic might induce idiopathic portal hypertension. The aim of this study was to experimentally identify how endothelin-1 is involved in the development of idiopathic portal hypertension and which cells produce endothelin-1 in the spleen. METHODS: Portal pressure and venous endothelin-1 concentrations were measured in rats that were given sodium arsenate orally for long periods, and endothelin-1 expression levels in the spleen were assessed by staining. In a second experiment, B and T lymphocytes and monocyte-derived macrophages cultured from healthy human peripheral blood were stimulated with sodium arsenite, sodium arsenate, lipopolysaccharide and interferon-gamma. Endothelin-1 concentrations in the supernatants were measured by ELISA. RESULTS: Arsenic exposure gradually increased portal pressure and venous endothelin-1 levels in rats. Endothelin-1 concentration in the supernatant did not change in every cell type stimulated with arsenic, but it increased in B lymphocytes and monocyte-derived macrophages treated with lipopolysaccharide and interferon-gamma. CONCLUSIONS: The in vivo study indicated that arsenic might elevate portal pressure through mechanisms involving endothelin-1. In the in vitro study, lipopolysaccharide and interferon-gamma clearly induced endothelin-1 synthesis not only in monocyte-derived macrophages but also in B lymphocytes, although arsenic treatment did not affect those cells. This study partially supports the hypothesis that idiopathic portal hypertension might be promoted by endothelin-1 overproduction from splenic B lymphocytes in response to certain substances.

Fractalkine-CX3CR1 axis regulates tumor cell cycle and deteriorates prognosis after radical resection for hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: Fractalkine is the only CX3C chemokine, and its receptor, CX3CR1, is expressed on NK cells, CD8+ T cells, monocytes, and dendritic cells (DC). Although studies have reported that fractalkine regulates the host immune response, the roles of the fractalkine-CX3CR1 axis in tumor biology and the clinical results of hepatocellular carcinoma (HCC) remain unknown. METHODS: Fractalkine and CX3CR1 expression in HCC were evaluated and compared with the clinicopathologic features, including tumor progression determined by proliferating cell nuclear antigen (PCNA) antibody and patient prognosis after surgery. RESULTS: Tumors with high expression of both fractalkine and CX3CR1 had significantly fewer intra- and extrahepatic recurrences, a low PCNA labeling index (PCNALI), and different histological grades. Patients with tumors that expressed both had a significantly better prognosis in terms of disease-free (DFS) and overall survival (OAS), and this finding was identified as one of the independent prognostic factors in the multivariate analysis. CONCLUSIONS: Our results suggest that the fractalkine-CX3CR1 axis plays a pivotal role in the prognosis of patients with HCC, which might arise from the known modulation of the host immune response, and that of the cell cycle in HCC.

FR-167653, a selective p38 MAPK inhibitor, exerts salutary effect on liver cirrhosis through downregulation of Runx2.

Liver cirrhosis remains a difficult-to-treat disease with a substantial morbidity and mortality rate. There is an emerging body of data purporting a pivotal role of the activated p38 mitogen-activated protein kinase (MAPK) in the process of cirrhosis. Several anticirrhotic agents have been developed over the past few years, and most of them exert their effects by indirectly inhibiting the p38 pathway. Effect of a selective p38 inhibitor is yet to be reported. In this study, we evaluated the salutary effect of FR-167653 (FR), a selective p38 inhibitor, in a carbon tetrachloride (CCl(4))-induced rat cirrhotic model. Twenty rats were assigned into four groups: Sham, olive oil only; Control, CCl(4) in olive oil; FR50, FR 50 mg/kg/day and CCl(4); and FR100, FR 100 mg/kg/day and CCl(4). FR dose-dependently inhibited activation of p38 and had an ameliorating effect on cirrhosis formation. Significant dose-dependent reduction in alpha-smooth muscle actin immunostaining and hydroxyproline content of the liver was noticed in the FR-treated rats. Also densitometric analysis showed a significant reduction in azan-stained area in the FR-treated rats. These fibrotic changes were observed in the myofibroblasts including the hepatic stellate cells and portal fibroblasts. mRNA expression of runt-related protein 2 (Runx2), a profibrogenic transcription factor, was significantly low in FR-treated livers, indicating that Runx2 might be a key downstream regulator of the p38 pathway. A similar reduction in expression of Smad4 and tissue inhibitor of metalloproteinase-1 was noticed in the FR-treated rats. In conclusion, FR treatment exerted a significant beneficial effect in a CCl(4)-induced rat cirrhotic model. The ameliorating effect of FR could be partially attributable to an inhibition of the Smad4/p38/Runx2 axis in the cirrhotic liver.

Tetracycline analogues (doxycycline and COL-3) induce caspase-dependent and -independent apoptosis in human colon cancer cells.

Tetracycline analogues (TCNAs) possess cytotoxic activities as well as matrix metalloproteinase (MMP) inhibitory properties. Previously, we demonstrated that doxycycline (DOXY) could induce apoptosis in human HT29 colon cancer cells. In present study, the molecular apoptotic mechanisms induced by two kinds of TCNAs, designated as DOXY and COL-3 (chemically modified tetracycline-3; 6-demethyl, 6-deoxy, 4-dedimethylamino tetracycline), were evaluated in cultured HT29 cells. Both TCNAs inhibited the proliferation of 6 different colorectal cancer cell lines in a dose-dependent manner. Especially, COL-3 had a stronger effect on cancer cells than DOXY. Apoptotic changes were actually observed by 10 mug/ml COL-3 and 20 mug/ml DOXY in a time-dependent manner. COL-3 produced the increase in cytosolic cytochrome c and the loss of mitochondrial membrane potential after 3 hr treatment, and thereafter activated caspases. In case of DOXY, these changes were observed after 24 hr. Bax translocation was not a prerequisite for cytochrome c releasing in COL-3 treatment. Pretreated pancaspase inhibitor (Z-VAD-FMK) reduced COL-3 and DOXY mediated apoptosis up to 81.3 and 35.3%, as compared with nontreated cells, respectively. These data indicated that TCNAs could induce mitochondria-mediated apoptosis through both caspase-dependent and -independent pathway. In fact, endonuclease G and apoptosis-inducing factor were released into cytosol after the treatment of TCNAs, which indicated that caspase-independent apoptotic pathway is also one of the key mechanisms for the treatment of TCNAs. Taken together, we believe that TCNAs could have strong potentials for clinical application in treating colorectal cancers and improve cancer chemotherapy.

Expression of hypoxia inducible factor-1alpha during liver regeneration induced by partial hepatectomy in rats.

BACKGROUND/AIMS: It has been well established that hypoxia inducible factor-1alpha (HIF-1alpha) transcribes essential factors in cell preservation, including angiogenesis, during hypoxia. However, the transition of HIF-1alpha expression during liver regeneration remains unknown. In this study, a role of HIF-1alpha was experimentally elucidated in relation to sinusoidal endothelial reconstruction during liver regeneration. METHODS: Expression of HIF-1alpha was evaluated in the regenerating liver following 70% hepatectomy in rats. Expressions of nuclear HIF-1alpha, vascular endothelial growth factor (VEGF) and fms-like tyrosine kinase-1 (flt-1) were measured by Western blot and liver blood flow by a laser Doppler. Sinusoidal endothelial cell area (SECA) and HIF-1alpha were localized by immunohistochemistry. HIF-1alpha mRNA was measured by reverse transcription-polymerase chain reaction. RESULT: Liver blood flow and SECA were lowest 36 and 72 h following hepatectomy, respectively. Nuclear HIF-1alpha peaked at 24 h and continuously increased 72-120 h following hepatectomy. This transition was fully supported by histological HIF-1alpha expression and HIF-1alpha mRNA up-regulation. VEGF and flt-1 peaked at 120 and 12 h, respectively. CONCLUSIONS: A significant evaluation in HIF-1alpha expression was revealed in regenerating rat livers. HIF-1alpha expression was preceded by VEGF and flt-1 expression and thus may be related to sinusoidal endothelial reconstruction.

Overexpression of macrophage migration inhibitory factor induces angiogenesis and deteriorates prognosis after radical resection for hepatocellular carcinoma.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pivotal cytokine that regulates inflammatory and immune responses. Recently, many investigators reported that MIF is expressed highly in several tumors, including hepatocellular carcinoma (HCC). However, the role of MIF in tumor angiogenesis and patient prognosis has not been examined in patients with HCC. METHODS: The authors evaluated MIF expression in 56 samples of HCC by Western blot analysis, and the results were correlated with clinicopathologic factors and patient prognosis. MIF localization was determined by immunohistochemical methods, and the results were compared with tumor microvessel density (MVD), as assessed by anti-CD34 antibody. Furthermore, to validate the role of MIF in angiogenesis, both MIF expression during culture of HCC cells (using the Hep3B, HepG2, and Huh7 cell lines) under hypoxic condition and the angiogenic potential of recombinant MIF in an in vitro angiogenic model were examined. RESULTS: Tumors with high MIF expression had high alpha-fetoprotein levels (P = 0.049) and frequent intrahepatic recurrence (P = 0.043). Immunohistochemical MIF scores had a significant correlation with MVD (P = 0.007). Patients who had tumors with high MIF expression levels had a significantly worse (P = 0.025) disease-free survival, and this finding remained significant as an independent prognostic factor in the multivariate analysis. Hep3B cells had high expression of MIF at 6 hours and 12 hours after hypoxic stress and exogenous MIF stimulated endothelial tube formation in in vitro angiogenesis. CONCLUSIONS: The current findings suggest that MIF expression may play a pivotal role in the dismal prognosis of patients with HCC that may be attributable to the modulation of angiogenesis.

Transforming growth factor-beta1 released from the spleen exerts a growth inhibitory effect on liver regeneration in rats.

Several previous reports indicated that partial hepatectomy (PH) when combined with splenectomy enhances the regenerative capacity of the liver, most probably due to the removal of unknown inhibitory factors released from the spleen. Transforming growth factor (TGF)-beta1 is a major antiproliferative factor for the hepatocytes, and the role of splenic TGF-beta1 in liver regeneration is yet to be clarified. The splenic expression of TGF-beta1 and its secretion into the portal circulation from the spleen were evaluated in a standardized two-thirds hepatectomy model in rats. Rats in the control group underwent only the hepatectomy, while splenectomy was added in the splenectomy group. The hepatocyte proliferation rate was assessed by proliferating cell nuclear antigen (PCNA) immunostaining, and the results were compared with the TGF-beta1 kinetics in the portal blood. Significant increase in PCNA index and decrease in portal TGF-beta1 level were noticed in the splenectomy group at 48 hours after PH compared with the control group. Both TGF-beta1 protein and mRNA expression level in the spleen were strongest at 48 hours after PH and coincided with the peak of the plasma TGF-beta1 level. TGF-beta type II receptor (TbetaR-II) expression in the liver after PH was assessed immunohistochemically. The expression of TbetaR-II decreased at 12 hours and returned to preoperative level at 24 hours after PH in both groups. The changes of TbetaR-II expression were similar in both groups, and the significant difference was not observed at 48 hours after PH. Namely, splenectomy did not alter the expression of TbetaR-II in remnant liver at the peak of hepatocytes proliferation. In conclusion we found that TGF-beta1 was produced and secreted by the spleen during the early phase of liver regeneration and removal of the spleen enhanced proliferation of hepatocytes. Splenectomy thus may exert a salutary effect in selected patients with jeopardized regenerative capacity of the liver.