TGR5 promotes cholangiocarcinoma by interacting with mortalin.

Takeda-G-protein-receptor-5 (TGR5) is a G-protein-coupled receptor (GPCR) activated by bile acids, and mortalin is a multipotent chaperone of the HSP70 family. In the present study, TGR5 was detected by immunohistochemistry (IHC) in extrahepatic cholangiocarcinoma (ECC) specimens, and TGR5 expression in ECC tissues and adjacent tissues was compared. In vitro TGR5 was overexpressed and knocked down in human intrahepatic cholangiocarcinoma (ICC) cell line RBE and human extrahepatic cholangiocarcinoma (ECC) cell line QBC-939 to observe its effects on the biological behavior of cholangiocarcinoma (CC) cells, including proliferation, apoptosis and migration. In vivo xenograft model was constructed to explore the role of TGR5 in CC growth. Proteins that interacted with TGR5 were screened using an immunoprecipitation spectrometry approach, and the identified protein was down-regulated to investigate its contribution to CC growth. The present study demonstrated that TGR5 is highly expressed in CC tissues, and strong TGR5 expression may indicate high malignancy in CC. Furthermore, TGR5 promotes CC cell proliferation, migration, and apoptosis resistance. TGR5 boosts CC growth in vivo. In addition, TGR5 combines with mortalin and regulates mortalin expression in the CC cell line. Mortalin participates in the TGR5-induced increase in CC cell proliferation. In conclusion, TGR5 is of clinical significance based on its implications for the degree of malignancy in patients with CC. Mortalin may be a downstream component regulated by TGR5, and TGR5 promotes cholangiocarcinoma at least partially by interacting with mortalin and upregulating its expression. Both TGR5 and mortalin are positive regulators, and may serve as potential therapeutic targets for CC.

Knockdown of Astrocyte Elevated Gene-1 Inhibits Activation of Hepatic Stellate Cells.

BACKGROUND: Astrocyte elevated gene-1 (AEG-1) is a positive regulator of tumorigenesis and a valuable prognostic marker of a diverse array of cancers, including liver cancer; however, the relationship between AEG-1 and hepatic fibrogenesis is not known. OBJECTIVE: The objective of this study was to explore the expression of AEG-1 during hepatic fibrogenesis and determine how AEG-1 regulates the profibrogenic phenotype of hepatic stellate cells (HSCs). METHODS: The levels of AEG-1 were monitored in the fibrotic livers and transforming growth factor-ß (TGF-ß)- or lipopolysaccharide (LPS)-stimulated HSCs. The expression of AEG-1 was knocked down by lentivirus-mediated short hairpin RNA in HSCs, and collagen expression, proliferation assays, apoptosis induction studies, and migration assays were simultaneously conducted in vitro. RESULTS: AEG-1 expression was increased in the fibrotic livers. At the cellular level, TGF-ß or LPS stimulation, which caused HSC activation, induced AEG-1 expression in HSC-T6 and primary rat HSCs (P < 0.05). Knockdown of AEG-1 inhibited collagen I and α-smooth muscle actin expression (P < 0.05), reduced cell proliferation (P < 0.05) and motility (P < 0.05), and induced cell apoptosis (P < 0.05) in HSCs. This antifibrotic effect caused by lack of AEG-1 was associated with the inactivation of PI3K/Akt and the mitogen-activated protein kinase pathway. CONCLUSIONS: Knockdown of AEG-1 suppressed the activation of HSCs by modulating the phenotype and inducing apoptosis. AEG-1 might be a potential target in treatment of hepatic fibrosis.

[Heme oxygenase-1 overexpression in patients with malignant obstructive jaundice].

OBJECTIVE: To investigate the role of heme oxygenase-1 (HO-1) in the oxidative stress damage of intestinal mucosa barrier disruption in patients with malignant obstructive jaundice (MOJ). METHODS: Fifteen jaundiced patients with malignant biliary obstruction undergoing endoscopic retrograde cholangiopancreatography (ERCP) examination or treatment were enrolled. The control group was comprised of 10 healthy subjects with gastroscopy and 10 patients with non-jaundiced biliary obstruction. Patients were subjected to duodenal biopsy to assess the intestinal oxidative stress as estimated by lipid peroxidation (malondialdehyde) and activity of superoxide dismutase (SOD). Apoptosis of epithelial cell was examined by TdT-mediated dUTP-biotin nick end labeling. Immunohistochemistry and Western blotting were employed to examine the distribution and expression of HO-1 proteins in intestinal mucosa. RESULTS: MOJ jaundiced patients presented high levels of intestinal oxidative stress with a significantly increased level of lipid peroxidation [(1.79 +/- 0.24) vs (1.09 +/- 0.28) vs (1.18 +/- 0.32) nmol x mg(-1) x prot(-1), P = 0.041] and a decreased SOD activity [(303 +/- 10) vs (398 +/- 11) vs (406 +/- 11) nmol x mg(-1) x prot(-1), P = 0.017]. The apoptotic rate of intestinal epithelial cells was significantly higher in jaundiced group than in non-jaundiced control group. Apoptotic index was (69.1 +/- 5.9)%, (28.6 +/- 3.5)% and (10.2 +/- 2.5)% respectively (P < 0.01). The staining of HO-1 was predominantly localized in cytoplasm. In jaundiced patients, HO-1 was obviously elevated than those in the control group (HO-1 optical density 0.28 +/- 0.04 vs 0.20 +/- 0.04 vs 0.13 +/- 0.05) (P < 0.01). Similar outcomes were obtained by quantitative analysis of Western blotting images [HO-1/GAPDH (10.7 +/- 0.7)% vs (7.6 +/- 0.5)% vs (3.9 +/- 0.4)%, P < 0.01]. CONCLUSION: MOJ induces intestinal oxidative stress and it may be a key contributing factor to intestinal barrier failure in the patient population. HO-1 protein level is rising with the progression of obstruction. Perhaps HO-1 has a protective effect upon MOJ through anti-oxidative damage.

[Decreased basic activity and induced activity of ERK1/2 pathway in hippocampal CA1/CA2 region of ovariectomized rats].

AIM: To investigate the relationship between the spatial learning and memory and hippocampal ERK1/2 pathway activity in ovariectomized rats. METHODS: Female SD rats were randomly divided into sham operated group (Sham group) and ovariectomized group (OVX group), and fed 4 months. Then spatial learning and memory of rats were evaluated by the Morris water maze task. Rats in each group were randomly divided into training group and untraining group before the test. Induced activity of ERK 1/2 stimulated by learning and memory was detected in the training group, and basic activity of ERK 1/2 was detected in the untraining group. The protein expression of p-ERK 1/2 and Raf kinase inhibitor protein (RKIP) were assayed by Western blotting respectively. RESULTS: (1) During the training session the OVX rats held longer escape latenci than the sham rats did (P < 0.05). (2) The relative level of pERK1/2 protein in training rats of the both groups was higher than that in untraining rats (P < 0.05). (3) The relative level of p-ERK1/2 protein both training and untraining rats in OVX group was lower than that in sham group correspondingly (P < 0.05). (4) Compared with sham group, the relative expression of RKIP in OVX group was significantly higher (P < 0.05). CONCLUSION: Spatial learning and memory deficits in ovariectomized rats might be correlated with the decreased basic and induced activity of ERK1/2 pathway and increased expression of RKIP in the CA1/CA2 region of hippocampus.