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Goshi Shiota

Publications and source records attributed to Goshi Shiota.

At least 19 recordsLinked to original sources
PubMed2007

Bone marrow-derived cells express matrix metalloproteinases and contribute to regression of liver fibrosis in mice.

UNLABELLED: Liver fibrosis is usually progressive, but it can occasionally be reversible if the causative agents are adequately removed or if patients are treated effectively. However, molecular mechanisms responsible for this reversibility of liver fibrosis have been poorly understood. To reveal the contribution of bone marrow (BM)-derived cells to the spontaneous regression of liver fibrosis, mice were treated with repeated carbon tetrachloride injections after hematopoietic reconstitution with enhanced green fluorescent protein (EGFP)-expressing BM cells. The distribution and characteristics of EGFP-positive (EGFP(+)) cells present in fibrotic liver tissue were examined at different time points after cessation of carbon tetrachloride intoxication. A large number of EGFP(+) cells were observed in liver tissue at peak fibrosis, which decreased during the recovery from liver fibrosis. Some of them, as well as EGFP-negative (EGFP(-)) liver resident cells, expressed matrix metalloproteinase (MMP)-13 and MMP-9. Whereas MMP-13 was transiently expressed mainly in the cells clustering in the periportal areas, MMP-9 expression and enzymatic activity were detected over the resolution process in several different kinds of cells located in the portal areas and along the fibrous septa. Therapeutic recruitment of BM cells by granulocyte colony-stimulating factor (G-CSF) treatment significantly enhanced migration of BM-derived cells into fibrotic liver and accelerated the regression of liver fibrosis. Experiments using transgenic mice overexpressing hepatocyte growth factor (HGF) indicated that G-CSF and HGF synergistically increased MMP-9 expression along the fibrous septa. CONCLUSION: Autologous BM cells contribute to the spontaneous regression of liver fibrosis, and their therapeutic derivation could be a new treatment strategy for intractable liver fibrosis.

Animals↗
PubMed2006

Transient expression of bone morphogenic protein-2 in acute liver injury by carbon tetrachloride.

Acute liver injury induced by administration of carbon tetrachloride (CCl4) was shown to be a model of wound-repair in rat liver. Albumin gene expression was significantly reduced at 24 h post injection with CCl4, but recovered at 48 h. We also observed significant and transient expression of bone morphogenic protein-2 (BMP-2) at 6-24 h post treatment. This expression was also shown with depletion of Kupffer cell by GdCl3, and immunostaining with anti-BMP-2 antibody showed BMP-2-producing cells interspersed in intralobular spaces of injured liver. These observations suggest that BMP-2 secreted from oval-like cells plays important roles in the wound healing response of injured liver.

Animals↗
PubMed2006

The liver as a target organ of retinoids.

Retinoids have several biological functions including cell growth, differentiation and apoptosis. In liver, retinoids are known to be associated with regeneration, fibrosis and carcinogenesis. The facts that retinoid droplets in stellate cells are lost with progression of liver disease and that effectiveness of an acyclic retinoid on second primary liver cancer suggest the importance of liver as a target organ of retinoids. Our recent work has indicated that retinoids have antioxidant effects in association with regulation of fatty acid metabolism. In this review article, we discussed the important function of retinoids in liver, mainly from molecular aspects.

Journal Article↗
PubMed2006

Naked gene therapy of hepatocyte growth factor for dextran sulfate sodium-induced colitis in mice.

Ulcerative colitis (UC) is progressive and relapsing disease. To explore the therapeutic effects of naked gene therapy of hepatocyte growth factor (HGF) on UC, the SRalpha promoter driving HGF gene was intrarectally administered to the mice in which colitis was induced by dextran sulfate sodium (DSS). Expression of the transgene was seen in surface epithelium, lamina propria, and muscularis mucosae. The HGF-treated mice showed reduced colonic mucosal damage and increased body weights, compared with control mice (P < 0.01 and P < 0.05, respectively). The HGF-treated mice displayed increased number of PCNA-positive cells and decreased number of apoptotic cells than in control mice (P < 0.01, each). Phosphorylated AKT was dramatically increased after HGF gene administration, however, phosphorylated ERK1/2 was not altered. Microarray analysis revealed that HGF induced expression of proliferation- and apoptosis-associated genes. These data suggest that naked HGF gene delivery causes therapeutic effects through regulation of many downstream genes.

Animals↗
PubMed2006

Evidence for a role of Collapsin response mediator protein-2 in signaling pathways that regulate the proliferation of non-neuronal cells.

Collapsin response mediator protein-2 or Crmp-2 plays a critical role in the establishment of neuronal polarity. In this study, we present evidence that apart from its functions in neurodevelopment, Crmp-2 is also involved in pathways that regulate the proliferation of non-neuronal cells through its phosphorylation by regulatory proteins. We show that Crmp-2 undergoes dynamic phosphorylation changes in response to contact inhibition-induced quiescence and that hyperphosphorylation of Crmp-2 occurs in a tumor. We further suggest that de-regulation of Crmp-2 phosphorylation levels at certain amino acid residues may lead to aberrant cell proliferation and consequently, tumorigenesis.

Animals↗
PubMed2006

Clinical usefulness of serum telomerase reverse transcriptase (hTERT) mRNA and epidermal growth factor receptor (EGFR) mRNA as a novel tumor marker for lung cancer.

Using a newly developed assay of telomerase reverse transcriptase (hTERT) mRNA in serum by real-time RT-PCR, we previously reported this assay to be superior to other tumor markers for hepatoma. In this study, we aimed to clarify its clinical significance as a biomarker for lung cancer. In 112 patients with lung tumor and 80 individuals without cancer, we measured serum hTERT mRNA and epidermal growth factor receptor (EGFR) mRNA levels, using a quantitative one-step real-time RT-PCR assay. We examined its sensitivity and specificity in lung cancer diagnosis, its clinical significance in comparison with other tumor markers, and its correlation with the clinical parameters using multivariate analyses and correlation relative tests. The copy number of serum hTERT mRNA was independently correlated with tumor size, tumor number, presence of metastasis and recurrence, and smoking (all P < 0.05). EGFR mRNA correlated with tumor number and clinical stage (both P < 0.05). The sensitivity and specificity in lung cancer diagnosis were 89.0% and 72.7% for hTERT mRNA, and 71.3% and 80.0% for EGFR mRNA, respectively. hTERT mRNA was superior to other tumor markers in lung cancer diagnosis. For both mRNAs, serum levels were significantly correlated with levels in lung cancer tissues (both P < 0.05). The copy number of hTERT mRNA significantly decreased after the surgical treatment. The data suggest that hTERT mRNA, especially when combined with EGFR mRNA, is a novel and excellent biomarker for pulmonary malignancies to diagnose and assess the clinical stage.

Adenocarcinoma↗
PubMed2006

Expression of oxidative stress-related molecules in circulating leukocytes and urine in patients with chronic viral hepatitis.

AIMS: Oxidative stress plays a role in pathogenesis of chronic viral hepatitis. Expression of oxidative stress-related molecules remains to be clarified. METHODS: 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), catalase, superoxide dismutase-1 (SOD-1), glutathione peroxidase-1, thioredoxin (TRX) in leukocytes and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) were examined in 164 persons, including 130 chronic viral hepatitis patients and 34 normal individuals, by Western blot analysis and enzyme-linked immunosorbent assay, respectively. Hepatic expression of these proteins was immunohistochemically examined in 12 patients with chronic viral hepatitis, compared with three persons without liver damage. RESULTS: The 4-HNE/beta-actin ratios in chronic viral hepatitis were significantly higher than those in normal individuals (P<0.01), and were significantly correlated with asparate aminotransferase (AST) and alanine aminotransferase (ALT) (P<0.01, each). The catalase/beta-actin and SOD-1/beta-actin ratios in chronic viral hepatitis were higher than those in normal individuals, and were significantly correlated with 4-HNE/beta-actin ratios (P<0.01, each). Hepatic expression of 4-HNE, 4-HHE, catalase, SOD-1 and TRX in chronic viral hepatitis was higher than that without liver damage. Urinary excretion of 8-OHdG was not changed in chronic viral hepatitis. CONCLUSIONS: The results of the present study suggest that expression of oxidative stress-related molecules in leukocytes is upregulated in relation to serum aminotransferase levels.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2005

Effect of promoter methylation of the p16 gene on phosphorylation of retinoblastoma gene product and growth of hepatocellular carcinoma cells.

The biological significance of hypermethylation of p16 gene promoter in human hepatocellular carcinoma (HCC) cells remains to resolved. In order to clarify the significance of methylation of p16 gene promoter, we examined the methylation status of p16 gene in association with phosphorylation of retinoblastoma gene product (pRb) and cell growth in human HCC cell lines. The presence of methylation was examined by methylation-specific PCR. Expression and phosphorylation of p16 and pRb were examined by Western blot analysis. Genetic changes were analyzed by multiplex PCR and DNA sequencing. The effect of demethylation of p16 was assessed by cell growth. p16 gene promoter was methylated in HuH7 and HLF cells. The demethylating agent, 5-aza-2-deoxycytidine (5-Aza-CdR), upregulated p16 mRNA in HuH6 and HuH7 cells. 5-Aza-CdR increased p16 protein expression in HuH6, HuH7, and HLF cells, and it clearly decreased the phosphorylation level of pRb in HuH6, HuH7 and PLC/PRF/5 cells. Treatment with 5-Aza-CdR inhibited the growth of HuH7 cells. Homozygous deletion and significant mutations were absent. Methylation in the p16 promoter region is biologically significant, being associated with phosphorylation of pRb and cell growth in human HCC cells.

Amino Acid Sequence↗
PubMed2005

Loss of function of retinoic acid in liver leads to steatohepatitis and liver tumor: A NASH animal model.

To explore the role of retinoic acid (RA) in liver, we developed transgenic mice expressing retinoic acid receptor alpha dominant negative form (RARE) in hepatocytes using by albumin promoter and enhancer. At 4 months of age, the RARE transgenic mice developed microvesicular steatosis and spotty focal necrosis. Mitochondrial beta-oxidation activity of fatty acids and expression of its related enzymes including VLCAD, LCAD and HCD were down-regulated. On the other hand, peroxisomal beta-oxidation and its related enzymes including AOX and BFE were up-regulated. Expression of CYP4a10, CYP4a12 and CYP4a14 was increased, suggesting that omega-oxidation of fatty acids in microsome was accelerated. In addition, formation of H(2)O(2) and 8-hydroxy-2'-deoxyguanosine was increased. After 12 months of age, these mice developed liver tumors which are hepatocellular carcinoma or adenoma. The incidence of tumor formation was increased with age. Expression of beta-catenin and cyclin D1 was enhanced, and TCF-4/beta-catenin complex was increased whereas RARalpha/beta-catenin complex was decreased. Feeding on high RA diet reversed histological and biochemical abnormalities, and inhibited occurrence of liver tumor. Taken together, hepatic loss of RA function leads to development of steatohepatitis and liver tumor and RA plays an important role in preventing hepatocarcinogenesis in association with fatty acid metabolism and Wnt signaling.

Journal Article↗
PubMed2005

Dual effects of adenovirus-mediated thrombopoietin gene transfer on hepatic oval cell proliferation and platelet counts.

Thrombopoietin (TPO) is the growth factor for megakaryocytes and platelets, however, it also acts as a potent regulator of stem cell proliferation. To examine the significance of TPO expression in proliferation of hepatic oval cells, the effect of adenovirus-mediated TPO gene transfer into livers of the Solt-Farber model, which mimics the condition where liver regeneration is impaired, was examined. Hepatic TPO mRNA peaked its expression at 2 days after gene transduction and then gradually decreased. The peripheral platelet number began to increase at 4 days (P<0.05) and reached its plateau at 9 days (P<0.01). Oval cells expressed c-Mpl, a receptor for TPO as well as immature hematopoietic and hepatocytic surface markers such as CD34 and AFP. The proliferating cell nuclear antigen-positive oval cells in rats into which adenovirus-TPO gene was transferred at 7 and 9 days were significantly greater than those in adenovirus-LacZ gene transferred (P<0.05, each), and the total numbers of oval cells in the adenovirus-TPO gene transferred at 9 and 13 days were also significantly greater than those in adenovirus-LacZ gene transferred (P<0.05, each). Expression of SCF protein was increased at 4, 7, and 9 days by TPO gene administration and that of c-Kit was increased at 4 and 7 days. These data suggest that adenovirus-mediated TPO gene transfer stimulated oval cell proliferation in liver as well as increasing peripheral platelet counts, emphasizing the significance of the TPO/c-Mpl system in proliferation of hepatic oval cells.

Adenoviridae↗
PubMed2005

Proteasomal degradation of Kir6.2 channel protein and its inhibition by a Na+ channel blocker aprindine.

ATP-sensitive K+ channels (K(ATP):SUR2A+Kir6.2) play a pivotal role in cardiac protection against ischemia and reperfusion injury. When expressed in COS cells, Kir6.2 was short-lived with a half-life time of 1.9 h. The half-life time of Kir6.2 was prolonged by proteasome inhibitors MG132, ALLN, proteasome inhibitor 1, and lactacystine, but not at all by a lysosomal inhibitor chloroquine. MG132 also increased the level of ubiquitinated Kir6.2 without affecting its localization in the endoplasmic reticulum and Golgi apparatus. In electrophysiological recordings, MG132 augmented nicorandil-activated K(ATP) currents in COS cells expressing SUR2A and Kir6.2 as well as the same currents in neonatal rat cardiomyocytes. Like MG132, a Na+ channel blocker aprindine prolonged the half-life time of Kir6.2 and augmented K(ATP). Finally, both aprindine and MG132 inhibited the 20S proteasome activity in vitro. These results suggest a novel activity of aprindine to enhance K(ATP) currents by inhibiting proteasomal degradation of Kir 6.2 channels, which may be beneficial in the setting of cardiac ischemia.

Animals↗
PubMed2005

Serum human telomerase reverse transcriptase messenger RNA as a novel tumor marker for hepatocellular carcinoma.

PURPOSE: We previously reported the usefulness of a qualified highly sensitive detection method for human telomerase reverse transcriptase (hTERT) mRNA in serum with 89.7% sensitivity for hepatocellular carcinoma (HCC). In this study, we developed a quantitative detection method for serum hTERT mRNA and examined the clinical significance in HCC diagnosis. EXPERIMENTAL BACKGROUND: In 64 patients with HCC, 20 with liver cirrhosis, 20 with chronic hepatitis, and 50 healthy individuals, we measured serum hTERT mRNA by using the newly developed real-time quantitative reverse transcription-PCR with SYBR Green I. We examined its sensitivity and specificity in HCC diagnosis, clinical significance in comparison with other tumor markers, and its correlations with the clinical variables by using multivariate analyses. RESULTS: Serum hTERT mRNA showed higher values in patients with HCC than those with chronic liver diseases. hTERT mRNA expression was shown to be independently correlated with clinical variables such as tumor size, number, and degree of differentiation (P < 0.001, each). The sensitivity/specificity of hTERT mRNA and alpha-fetoprotein (AFP) mRNA in HCC diagnosis were 88.2%/70.0% for hTERT and 71.6%/67.5% for AFP, respectively. hTERT mRNA proved to be superior to AFP mRNA, AFP, and des-gamma-carboxy prothrombin in HCC diagnosis. Furthermore, hTERT mRNA in serum was associated with that in HCC tissue. CONCLUSIONS: The usefulness of hTERT mRNA expression in HCC diagnosis and its superiority to conventional tumor markers were shown. Therefore, serum hTERT mRNA is a novel and available marker for HCC diagnosis.

Adult↗
PubMed2005

Therapeutic effect of adenoviral-mediated hepatocyte growth factor gene administration on TNBS-induced colitis in mice.

Inflammatory bowel disease is incurable and relapsing disease. In order to clarify the effect of HGF gene therapy for inflammatory bowel disease, the adenoviral-mediated HGF gene was intrarectally administered into TNBS-colitis-induced Balb/c mice. Adenoviral-mediated gene delivery targetted its expression mainly to intestinal epithelial cells. Mucosal damage of HGF-treated intestine was significantly improved, and compared with LacZ-treated and saline administered mice (P<0.05, each). The mice treated with intrarectal administration of pAxCAHGF showed an increased average of body weight in comparison with that of pAxCALacZ-treated and saline-treated mice (P<0.05, each). The PCNA-positive cells in pAxCALacZ-treated mice were 44.7+/-4.9%, 51.7+/-6.6%, and 53.9+/-4.5% at 10, 15, and 21 days after TNBS administration, however those in pAxCAHGF-treated mice were increased to 74.3+/-5.1%, 67.1+/-2.6%, and 69.2+/-4.6% (P<0.05, each). The TUNEL-positive cells in pAxCALacZ-treated mice were 13.3+/-5.2%, 11.5+/-2.1%, and 7.2+/-5.2%, respectively. However, those in pAxCAHGF-treated mice at 10, 15, and 21 days were significantly decreased to 5.4+/-1.8%, 3.8+/-1.3%, and 5.7+/-2.8% (P<0.05, respectively). Expression of ERK1/2 was stronger in pAxCAHGF mice than in pAxCALacZ. These data suggest that adenoviral-mediated HGF gene therapy via an intrarectal route is a promising therapy for inflammatory bowel disease.

Adenoviridae↗
PubMed2005

Effects of angiotensin II on the action potential durations of atrial myocytes in hypertensive rats.

Angiotensin II (Ang II) has been reported to indirectly influence atrial electrical activity and to play a critical role in atrial arrhythmias in hypertensive patients. However, it is unclear whether Ang II has direct effects on the electrophysiological activity of the atrium affected by hypertension. We examined the effects of Ang II on the action potentials of atrial myocytes enzymatically isolated from spontaneous hypertensive rats (SHRs). The action potentials were recorded by the perforated patch-clamp technique and the atrial expression of the receptors AT1a and AT2 was measured by radioimmunoassay. Ang II significantly shortened the action potential durations (APDs) of SHRs without changes in the resting membrane potentials (RMPs). Pretreatment with selective AT1a blockers abolished the Ang II-induced reduction of atrial APDs of SHRs; however, a selective AT2 blocker did not, which was consistent with the results of the receptor assay. Pretreatment with phosphatidylinositol 3 (PI3)-kinase inhibitor, phospholipase C inhibitor, or protein kinase C (PKC) inhibitor abolished the Ang II-induced shortening of atrial APDs, but pertussis toxin and protein kinase A (PKA) inhibitor did not. To study the effects of chronic AT1a inhibition on Ang II-induced shortening of atrial APD, SHRs were treated with AT1a blocker for 4 weeks. AT1a blocker abolished the Ang II-induced reduction of atrial APDs of SHRs and also significantly lowered their blood pressure. In conclusion, Ang II shortened atrial APDs of SHRs via AT1a coupled with the Gq-mediated inositol triphosphate (IP3)-PKC pathway. Our findings indicated that Ang II caused atrial arrhythmias in hypertensive patients by shortening the effective refractory period of the atrium.

Action Potentials↗
PubMed2004

Analyses to clarify rich fractions in hepatic progenitor cells from human umbilical cord blood and cell fusion.

Umbilical cord blood (UCB) is a source of hematopoietic stem cells and other stem cells, and human UCB cells have been reported to contain transplantable hepatic progenitor cells. However, the fractions of UCB cells in which hepatic progenitor cells are rich remain to be clarified. In the present study, first, the fractionated cells by CD34, CD38, and c-kit were transplanted via portal vein of NOD/SCID mice, and albumin mRNA expression was examined in livers at 1 and 3 months posttransplantation. At 1 and 3 months, albumin mRNA expression in CD34+UCB cells-transplanted livers was higher than that in CD34- cells-transplanted livers. Albumin mRNA expression in CD34+CD38+ cells-transplanted livers was higher than that in CD34+CD38- cells-transplanted [corrected] liver at 1 month. However, it was much higher [corrected] in CD34+CD38- cell-transplanted livers at 3 months. Similar expression of albumin mRNA was obtained between CD34+CD38+c-kit+ cells- and CD34+CD38-c-kit- cells-transplanted livers, and between CD34+CD38-c-kit+ cells- and CD34+CD38-c-kit- cells-transplanted livers, respectively. Second, fluorescence in situ hybridization and immunohistochemistry were performed to examine whether UCB cells really transdifferentiated into hepatocytes or they only fused with mouse hepatocytes. In mouse liver sections, of 1.2% cells which had human chromosomes, 0.9% cells were due to cell fusion, whereas 0.3% cells were transdifferentiated into human hepatocytes. These results suggest that CD34+UCB cells are rich fractions in hepatic progenitor cells, and that transdifferentiation from UCB cells into hepatocytes as well as cell fusion simultaneously occur in this situation.

ADP-ribosyl Cyclase↗