Human umbilical cord-derived mesenchymal stem cells in acute liver injury: Hepatoprotective efficacy, subchronic toxicity, tumorigenicity, and biodistribution.

Umbilical cord-derived mesenchymal stem cells (UC-MSCs) therapy might be an alternative to liver transplantation for acute or chronic liver injury. The aim of this study was to evaluate the efficacy of human UC-MSCs on carbon tetrachloride (CCl4)-induced acute liver injury. In addition, its toxicity, tumorigenicity, and biodistribution were determined. Significant hepatoprotective effects of hUC-MSCs with decreased levels of hepatocellular necrosis and lobular neutrophilic infiltration were found. Regarding the safety of hUC-MSCs, no serious hUC-MSCs-related changes (body weight, food/water consumption, clinical symptom, urinalysis, hematology, clinical chemistry, organ weight, and histopathology) were observed in a 13-week subchronic toxicity study. In a 26-week tumorigenicity study, no mice developed tumor related to hUC-MSCs transplantation up to 1 × 108 cells/kg. In particular, human mitochondrial sequence detection revealed that most hUC-MSCs were cleared from the major organs of the mice at 13 weeks after transplantation. There was no systemic toxicity or neoplastic finding either. Taken together, these results suggested that hUC-MSCs have great potential for future clinical treatment of acute liver disease.

Therapeutic effect of hepatocyte growth factor-secreting mesenchymal stem cells in a rat model of liver fibrosis.

Bone marrow-derived mesenchymal stromal cells (MSCs) have been reported to be beneficial for the treatment of liver fibrosis. Here, we investigated the use of genetically engineered MSCs that overexpress hepatocyte growth factor (HGF) as a means to improve their therapeutic effect in liver fibrosis. Liver fibrosis was induced by intraperitoneal injection of dimethylnitrosamine. HGF-secreting MSCs (MSCs/HGF) were prepared by transducing MSCs with an adenovirus carrying HGF-encoding cDNA. MSCs or MSCs/HGF were injected directly into the spleen of fibrotic rats. Tissue fibrosis was assessed by histological analysis 12 days after stem cell injection. Although treatment with MSCs reduced fibrosis, treatment with MSCs/HGF produced a more significant reduction and was associated with elevated HGF levels in the portal vein. Collagen levels in the liver extract were decreased after MSC/HGF therapy, suggesting recovery from fibrosis. Furthermore, liver function was improved in animals receiving MSCs/HGF, indicating that MSC/HGF therapy resulted not only in reduction of liver fibrosis but also in improvement of hepatocyte function. Assessment of cell and biochemical parameters revealed that mRNA levels of the fibrogenic cytokines PDGF-bb and TGF-ß1 were significantly decreased after MSC/HGF therapy. Subsequent to the decrease in collagen, expression of matrix metalloprotease-9 (MMP-9), MMP-13, MMP-14 and urokinase-type plasminogen activator was augmented following MSC/HGF, whereas tissue inhibitor of metalloprotease-1 (TIMP-1) expression was reduced. In conclusion, therapy with MSCs/HGF resulted in an improved therapeutic effect compared with MSCs alone, probably because of the anti-fibrotic activity of HGF. Thus, MSC/HGF represents a promising approach toward a cell therapy for liver fibrosis.

Reactivation of p53 in cells expressing hepatitis B virus X-protein involves p53 phosphorylation and a reduction of Hdm2.

Multifunctional activities of the hepatitis B virus X-protein (HBx) in cells have been largely implicated in the development of liver cancer; one of these activities is the loss of p53 function by sequestering p53 in the cytoplasm. We have previously found that doxorubicin increased the p53 levels in cells containing p53-binding HBx protein and restored the p53-mediated transcriptional activity that was suppressed by HBx. Here, we investigated the mechanism underlying p53 reactivation. We found that six phosphorylation sites of the Serine residues of p53 were efficiently phosphorylated in HBx-expressing ChangX-34 cells, suggesting that the binding of HBx to the p53 protein does not interfere with the phosphorylation of p53 by signaling kinases. In addition, doxorubicin caused a dramatic reduction of Hdm2 mRNA and protein levels in cells expressing HBx. Intriguingly, reactivation of p53 was accompanied with a nuclear accumulation of p53 and the phosphorylated p53 at Serine15 was only detected in nuclear fraction, but not in cytosolic fraction of doxorubicin-treated ChangX-34 cells. Functional restoration of the p53 protein in HBx-expressing cells occurs according to the dual effects of doxorubicin: a significant reduction of Hdm2 expression and a nuclear accumulation of the phosphorylated p53 protein. Thus, proper usage of doxorubicin as an effective antitumor agent may be reevaluated and can be extended to tumors primarily caused by infection of DNA tumor viruses.

Sulforaphane sensitizes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant hepatoma cells to TRAIL-induced apoptosis through reactive oxygen species-mediated up-regulation of DR5.

Sulforaphane is a chemopreventive agent present in various cruciferous vegetables, including broccoli. Here, we show that treatment with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in combination with subtoxic doses of sulforaphane significantly induces rapid apoptosis in TRAIL-resistant hepatoma cells. Neither TNF-alpha- nor Fas-mediated apoptosis was sensitized in hepatoma cells by cotreatment with sulforaphane, suggesting that sulforaphane can selectively sensitize cells to TRAIL-induced apoptosis but not to apoptosis mediated by other death receptors. We found that sulforaphane treatment significantly up-regulated mRNA and protein levels of DR5, a death receptor of TRAIL. This was accompanied by an increase in the generation of reactive oxygen species (ROS). Pretreatment with N-acetyl-l-cysteine and overexpression of catalase inhibited sulforaphane-induced up-regulation of DR5 and almost completely blocked the cotreatment-induced apoptosis. Furthermore, the sulforaphane-mediated sensitization to TRAIL was efficiently reduced by administration of a blocking antibody or small interfering RNAs for DR5. These results collectively indicate that sulforaphane-induced generation of ROS and the subsequent up-regulation of DR5 are critical for triggering and amplifying TRAIL-induced apoptotic signaling. We also found that sulforaphane can sensitize both Bcl-xL- and Bcl-2-overexpressing hepatoma cells to TRAIL-induced apoptosis, indicating that treatment with a combination of TRAIL and sulforaphane may be a safe strategy for treating resistant hepatomas.

Favorable outcomes of hilar duct oriented hepatic resection for high grade Tsunoda type hepatolithiasis.

AIM: To evaluate the efficacy of hilar duct oriented hepatectomy for intractable hepatolithiasis, the ventral hilum exposure (VHE) method that has been applied by the authors. METHODS: From June 1994 to June 2004 for a period of 10 years, 153 patients who had Tsunoda type III or IV hepatolithiasis, received hepatectomy at our institution. Among these patients, 128 who underwent hepatectomy by the VHE method were the subjects for the study. We analyzed the risk of this procedure, residual rate of intra-hepatic stones, and stone recurrent rates. RESULTS: The average age was 54.2 years, and the male to female ratio was 1:1.7. The average follow-up period was 25.6 mo (6-114 mo). There was no post-operative severe complication or mortality after the operation. The rate of residual stones was 5.4% and the rate of recurrent stones was 4.2%. CONCLUSION: VHE is a safe surgical procedure and provides favorable treatment results of intractable hepatolithiasis. Especially, this procedure has advantage in that intra-hepatic bile duct stricture may be confirmed and corrected directly during surgery.

Modulation of E-cadherin by hepatocyte growth factor induces aggressiveness of gastric carcinoma.

OBJECTIVE: Hepatocyte growth factor (HGF) is well known as a scatter factor because it can disperse cells. E-cadherin is a protein that plays a main role in the establishment of cell-cell adhesion. This study focused on the role of HGF on the expression and distribution of E-cadherin. Furthermore, we found induction of aggressiveness of gastric carcinoma by modulation of E-cadherin by HGF. MATERIALS AND METHODS: Tumor tissues from 50 patients with gastric carcinoma were evaluated for the expression of HGF, its receptor c-Met, and E-cadherin. Western blot analysis and invasion assay were performed to confirm the role of HGF on the modulation of E-cadherin using human gastric cancer cell lines. RESULTS: Seventy-eight percent of the gastric carcinoma tissues showed overexpression of c-Met. E-cadherin expression was found in 86%, which could be further classified as membranous type (52%) or nonmembranous type (48%). The levels of HGF in tumor tissues increased significantly according to the tumor progression. The levels of HGF in tumors with nonmembranous type E-cadherin expression were significantly higher than those in tumors with membranous expression. A striking morphologic change from epithelial shape to fibroblastic shape was observed in SNU-16 cells after 3 days' exposure to HGF, accompanied by down-regulation of functional E-cadherin in the membrane. Treatment of the cells with HGF induced significant invasion into the matrigel. CONCLUSION: We can conclude that HGF can modulate the expression of E-cadherin in gastric carcinoma, which was accompanied by more aggressive phenotype.

Presence of autocrine hepatocyte growth factor-Met signaling and its role in proliferation and migration of SNU-484 gastric cancer cell line.

Autocrine stimulation via coexpression of hepatocyte growth factor (HGF) and its receptor (Met) has been reported in many human sarcomas, but few in carcinomas. In this report, we found that one gastric cancer cell line, SNU-484, among 11 gastric cell lines tested has an autocrine HGF- Met stimulation. RT-PCR, ELISA and scattering assay using MDCK cells revealed that SNU-484 cells secreted a significant amount of active HGF (about 1.25 +/- 0.41 ng/24 h/10(6) cells) into conditioned medium. Resultantly, Met in this cell line was constitutively phosphorylated. Neutralizing antibodies against HGF reduced the tyrosine phosphorylation of Met, resulting in the inhibition of cell proliferation and migration (P <0.005). To the best of our knowledge, this is the first report on autocrine HGF-Met signaling in a gastric cancer cell line. Our observations with SNU-484 cells suggest that HGF is involved in the development and/or progression of some gastric carcinoma through an autocrine mechanism.

Two distinct modes of cell death induced by doxorubicin: apoptosis and cell death through mitotic catastrophe accompanied by senescence-like phenotype.

Chronic exposure of many human hepatoma cell lines to a low dose (LD) of doxorubicin induced a senescence-like phenotype (SLP) accompanied by enlargement of cells and increased senescence-associated beta-galactosidase activity. LD doxorubicin-induced SLP was preceded by multinucleation and downregulation of multiple proteins with mitotic checkpoint function, including CENP-A, Mad2, BubR1, and Chk1. LD doxorubicin-treated cells eventually underwent cell death through mitotic catastrophe. When we investigated whether LD doxorubicin-induced cell death shares biochemical characteristics with high dose (HD) doxorubicin-induced apoptosis in Huh-7 cells, we observed that externalization of phosphatidyl serine and release of mitochondrial cytochrome c into the cytosol was associated with both types of cell death. However, propidium iodide exclusion assays showed that membrane integrity was lost in the initial phase of LD doxorubicin-induced cell death through mitotic catastrophe, whereas it was lost during the late phase of HD doxorubicin-induced apoptosis. Furthermore, HD doxorubicin-induced apoptosis but not LD doxorubicin-induced mitotic catastrophe led to transient activation of NF-kappaB and strong, sustained activations of p38, c-Jun N-terminal kinase, and caspases. Collectively, these results indicate that different doses of doxorubicin activate different regulatory mechanisms to induce either apoptosis or cell death through mitotic catastrophe.

Amylase level in extrahepatic bile duct in adult patients with choledochal cyst plus anomalous pancreatico-biliary ductal union.

AIM: To investigate the relationship between pancreatic amylase in bile duct and the clinico-pathological features in adult patients with choledochal cyst and anomalous pancreatico-biliary ductal union (APBDU). METHODS: From 39 patients who underwent surgery for choledochal cyst between March 1995 and March 2003, we selected 15 adult patients who had some symptoms and were radiologically diagnosed as APBDU, and their clinico-pathological features were subsequently evaluated retrospectively. However, we could not obtain biliary amylase in all the patients because of the surgeon's slip. Therefore, we measured the amylase level in gall bladder of 10 patients and in common bile duct of 11 patients. RESULTS: Levels of amylase in common bile duct and gall bladder ranged from 11,500 to 212,000 IU/L, and the younger the patients, the higher the biliary amylase level (r = -0.982, P<0.01). Pathologically, significant correlation was found between the size of choledochal cyst and the grade of inflammation (r = 0.798, P<0.01). And, significant correlation was found between the level of amylase in gall bladder and the grade of hyperplasia. On the other hand, there was no correlation to the age of symptomatic onset or inflammatory grade (r = 0.743, P<0.05). Level of lipase was elevated from 6,000 to 159,000 IU/L in bile duct and from 14,400 to 117,000 IU/L in the gall bladder; however, there was no significant correlation with age or clinico-pathological features. CONCLUSION: The results support the notion that amylase has a particular role in the onset of symptoms, and suggest that a large amount of biliary amylase induces early onset of symptom, thereby making early diagnosis possible.

Growth inhibition and apoptosis in liver myofibroblasts promoted by hepatocyte growth factor leads to resolution from liver cirrhosis.

Liver cirrhosis is characterized by hepatic dysfunction with extensive accumulation of fibrous tissue in the liver. In response to chronic hepatic injury, hepatic portal myofibroblasts and activated hepatic stellate cells (HSCs) play a role in liver fibrosis. Although administration or gene expression of hepatocyte growth factor (HGF) leads to improvement in hepatic fibrosis/cirrhosis, the related mechanisms are not fully understood. We investigated mechanisms involved in resolution from liver cirrhosis by HGF, focusing on growth regulation and apoptosis in portal myofibroblasts. Cultured rat HSCs could not proliferate, were withdrawn after passage, and were replaced by proliferating portal myofibroblasts during the passages. In quiescent HSCs, c-Met receptor expression was undetected whereas c-Met receptor expression was detected in activated HSCs and liver myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA), suggesting that activated HSCs and portal myofibroblasts are targets of HGF. For cultured rat portal myofibroblasts, HGF counteracted phosphorylation of extracellular signal-regulated kinase (Erk) 1/2 and mitogenic stimulus induced by platelet-derived growth factor, induced c-jun N-terminal kinase (JNK) 1 phosphorylation, and promoted apoptotic cell death. In the dimethylnitrosamine rat model of liver cirrhosis, administration of HGF suppressed proliferation while promoting apoptosis of alpha-SMA-positive cells in the liver, events that were associated with reduced hepatic expressions of alpha-SMA and histological resolution from liver cirrhosis. Growth inhibition and enhanced apoptosis in portal myofibroblasts by HGF are newly identified mechanisms aiding resolution from liver fibrosis/cirrhosis by HGF.

Effects of suppressing intrarenal angiotensinogen on renal transforming growth factor-beta1 expression in acute ureteral obstruction.

BACKGROUND: Angiotensin II (Ang II) mediates the up-regulation of fibrogenic factors such as transforming growth factor-beta1 (TGF-beta1) in chronic renal diseases. In addition, it has been proposed that the intrarenal renin-angiotensin system (RAS) is as important as the systemic RAS in kidney disease progression. METHODS: We suppressed angiotensinogen (AGT) gene expression in the kidney by transferring recombinant adenoviral vectors carrying a transgene expressing AGT antisense mRNA, and determined the effect of the local inhibition of the RAS on TGF-beta1 synthesis in the kidneys of rats with unilateral ureteral obstruction (UUO). Immediately after UUO, recombinant adenovirus vectors were injected intraparenchymally into the cortex of obstructed kidneys. RESULTS: beta-galactosidase (beta-gal)-stained kidney sections revealed the efficient transduction of the recombinant adenoviral vectors into tubular epithelial cells. Kidney cortex injected with AGT antisense showed significantly lower native AGT mRNA and protein expressions than control UUO kidneys at 24 hours and 5 days post-UUO. TGF-beta1 was significantly up-regulated in the renal cortex 24 hours and 5 days post-UUO, whereas AGT antisense-injected UUO rats showed significantly reduced TGF-beta1 expression compared to control UUO rats. Both fibronectin and collagen type I expressions were increased 24 hours and 5 days post-UUO, and these augmentations were considerably reduced by AGT antisense RNA treatment. CONCLUSION: This study demonstrates that the suppression of intrarenal RAS prevents the formation of renal cortical TGF-beta1, and of related fibrogenic factors, in early UUO.

Risk factor for extrahepatic bile duct cancer in patients with anomalous pancreaticobiliary ductal union.

BACKGROUND/AIMS: Anomalous connection between the choledochus and pancreatic duct is considered to be a factor in the development of biliary tract diseases such as choledochal cyst, pancreatitis, cholangitis, gallbladder cancer, and bile duct cancer. Our purpose was analysis of combined disease, especially biliary neoplasm and evaluated microscopic changes of extrahepatic bile ducts. METHODOLOGY: To study the clinical characteristics of anomalous pancreaticobiliary ductal union (APBDU), we reviewed 14 APBDU cases from June 1994 to June 1998. We studied the associated disease, surgical treatment, and the histological findings of the extrahepatic bile ducts. RESULTS: Gallbladder cancer was identified in 5 out of 14 patients with APBDU. The incidences of metaplasia of gallbladder and bile duct with APBDU were higher than that of control gallbladder epithelium. The proliferating cell nuclear antigen-labeling index of the gallbladder in patients with APBDU was significantly higher than that in the control group. CONCLUSIONS: The patients with APBDU showed high incidence of gallbladder carcinoma and metaplasia in epithelium of gallbladder and bile duct. As this metaplasia in the gallbladder and bile duct is thought of as a precancerous condition, it is important to remove the place that causes bile stasis and to stop backflow of pancreatic juice into the bile duct in managing patients with this anomaly. In other words, prophylactic cholecystectomy and reconstruction of the biliary tract are both necessary.