scholarly journals Taurocholate Induces Connective Tissue Growth Factor Expression in Hepatocytes Through ERK-YAP Signaling

2018 ◽  
Vol 50 (5) ◽  
pp. 1711-1725
Author(s):  
Bin Yu ◽  
Guan-nan Jin ◽  
Mei Ma ◽  
Hui-fang Liang ◽  
Bi-xiang Zhang ◽  
...  

Background/Aims: Cholestasis is characterized by intrahepatic accumulation of cytotoxic bile acids (BAs), ultimately leading to fibrosis and cirrhosis, but the precise role of BAs in cholestasis-induced liver fibrosis remains largely elusive. In this study, we investigated the role and the potential mechanisms of BAs during cholestasis in vivo and in vitro. Methods: The effect of BAs during cholestasis was studied in bile duct ligation (BDL) rat models in vivo. We performed immunohistochemistry, Western blotting, and quantitative RT-PCR to investigate the expression of connective tissue growth factor (CTGF/CCN2) in rat liver during cholestasis. The hepatic cell lines AML12 and BRL were stimulated with taurocholate (TC) and the level of CTGF/CCN2, and activation of ERK, Akt, p38 MAPK, JNK, YAP, and TGF-β/Smad signaling were examined using Western blotting. Next, to elucidate the mechanism underlying bile acid-induced CTGF/CCN2, we treated the cells with MEK1/2 inhibitor (U0126), YAP function inhibitor (verteporfin), p38 kinase inhibitor (SB203580), Akt inhibitor (MK2206), and small interfering RNA (siRNA) targeting mek1, erk, and yap in cooperation with TC. Besides, we confirmed the activation of these signaling pathways in BDL and sham rat livers by immunohistochemistry, Western blotting, and quantitative RT-PCR. Results: In this study, we confirmed that the expression of CTGF/CCN2 was increased in BDL-induced rodent cholestatic liver fibrosis. In addition, we showed that TC, the main component of BAs, enhanced the synthesis of CTGF/ CCN2 in AML12 and BRL hepatic cell lines. Moreover, we demonstrated that TC activated ERK, Akt, and YAP signaling in hepatocytes, but the precise roles of these signaling cascades in the expression of CTGF/CCN2 were different: TC-induced expression of CTGF/CCN2 was mediated by ERK-YAP signaling, whereas Akt signaling inhibited ERK signaling and YAP and subsequently the expression of CTGF/CCN2 in hepatocytes. Furthermore, YAP functioned as a downstream regulator of ERK signaling in TC-induced CTGF/CCN2 expression in hepatocytes. Conclusion: Our report provides evidence for the role of conjugated BAs in liver fibrosis and suggests that the production of CTGF/CCN2, induced by conjugated BAs via ERK-YAP axis activation, may be a therapeutic target in cholestasis-induced liver fibrosis.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4025-4025
Author(s):  
Jing Fu ◽  
Shirong Li ◽  
Rentian Feng ◽  
Huihui Ma ◽  
Farideh Sabeh ◽  
...  

Abstract Abstract 4025 Background: MM cells produce several osteoclast-activating factors, which result in highly activated osteoclasts and cause dysregulated bone remodeling with excessive bone resorption. Our previous data showed that matrix metalloproteinase 13 (MMP13) is highly expressed in MM cells, and co-culture with stromal cells further increased MMP13 levels. Most importantly, exogenous MMP13 increased OCL fusion and bone resorption activity induced by nuclear factor kappa-B ligand (RANKL). Here, we further addressed the mechanism of MMP13 upregulation in MM and its role in MM-related bone disease in vivo. Methods and Results: Based upon the previous results that IL-6 neutralizing antibody blocks MMP13 upregulation in MM cells co-cultured with stromal cells, we further investigated the role of IL-6 on MMP13 induction in MM cells. Human RPMI8266 MM cells were serum-starved for 24 hours, then treated with IL-6 for up to 96 hours. RT-PCR and western blotting showed that MMP13 expression and secretion by MM cells were upregulated after 24h and prolonged through 96h. AP-1 binding sites were identified in the MMP13 promoter, and we found that IL-6 induced upregulation of the AP-1 members c-Jun and c-fos in MM cells by RT-PCR and western blotting, which correlated with MMP13 induction. To address the role of heightened MMP13 expression/secretion of MM on OCL formation and development of lytic lesions, we silenced MMP13 expression in MM cells by lentiviral mediated shRNA transduction. 5TGM1 mouse MM cells were infected with the pKLO.1-puro-vector (EV) or pKLO.1-puro-sh-MMP13 (MMP13 Knock down [KD]) lentivirus particles and cells were selected by puromycin. MMP13 KD was confirmed by RT-PCR and western blotting. To investigate the effects of MMP13 KD on OCL formation, we co-cultured mouse bone marrow cells (BMC) with either 5TGM1-EV or 5TGM1-MMP13 KD MM cells using a transwell system to permit only soluble molecule exchange. Co-culture with 5TGM1-EV MM cells significantly (p<0.01) induced OCL fusion, while this effect was largely impaired in the co-culture group with 5TGM1-MMP13 KD MM cells. Treatment with IL-6 further enhanced the OCL fusion activity in both groups. However, in 5TGM1-MMP13 KD group, IL-6 did not compensate for impaired OCL formation due to MMP13 silencing. This indicates that MMP13 secreted from MM cells is one of the key factors facilitating OCL formation/activity in MM. We further investigated the effects of MMP13 silencing on MM tumor progression and bone disease in vivo using the 5TGM1 intratibial tumor model. Recombination activating genes 2 (RAG2) knockout mice were intratibially injected with either 5TGM1-EV or 5TGM1-MMP13 KD MM cells, and 3 weeks later, mice were sacrificed and tumor growth and bone lytic lesion were monitored by serum IgG2b level (by Elisa) and micro-QCT respectively. Preliminary results show that MMP13 KD in MM cells inhibited tumor growth and lytic lesions in trabecular bone. Conclusion: Our results demonstrate that IL-6-induced high level of MMP13 in MM cells is essential for multiple myeloma tumor growth, OCL induction and development of lytic bone lesions. Disclosures: Lentzsch: Celgene: Consultancy, Research Funding.


2007 ◽  
Vol 293 (5) ◽  
pp. F1468-F1475 ◽  
Author(s):  
Jie Xu ◽  
Bing Yao ◽  
Xiaofeng Fan ◽  
Melissa M. Langworthy ◽  
Ming-Zhi Zhang ◽  
...  

Serotonin [5-hydroxytryptamine (5HT)] acts through multiple G protein-coupled 5-HT receptors, and its activity is also regulated by the 5-HT transporter. The current studies report the expression and localization of the 5-HT receptors and transporter in the kidney. In addition, the enzymatic pathway mediating 5-HT synthesis is present in renal cortex, especially in the proximal tubules and glomerular epithelial cells and mesangial cells. Expression of the 5-HT receptors and 5-HT transporter was detected by RT-PCR in cell lines of these cell types. In cultured proximal tubule cells and podocytes, 5-HT activated ERK1/2 and increased the expression of connective tissue growth factor and transforming growth factor-β, two key mediators of extracellular matrix accumulation. Immunohistochemistry and real-time RT-PCR studies also indicated that 5-HT stimulated expression of vascular endothelial growth factor in podocytes in vitro and in vivo. Therefore, these results indicate the presence of an integrated intrarenal serotonergic system and suggest a possible role for 5-HT as a mediator of renal fibrosis in the kidney.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Yao Wang ◽  
Fan Yang ◽  
Jun Xue ◽  
Xuan Zhou ◽  
Lei Luo ◽  
...  

ABSTRACT This study investigated the antischistosomiasis liver fibrosis effects of chlorogenic acid (CGA) on interleukin 13 (IL-13)/microRNA-21 (miR-21)/Smad7 signaling interactions in the hepatic stellate LX2 cell line and schistosome-infected mice. The transfection was based on the ability of the GV273–miR-21–enhanced green fluorescent protein (EGFP) and GV369–miR-21–EGFP lentiviral system to up- or downregulate the miR-21 gene in LX2 cells. The mRNA expression of miR-21, Smad7, and connective tissue growth factor (CTGF) and the protein expression of Smad7, CTGF, Smad1, phosphor-Smad1 (p-Smad1), Smad2, p-Smad2, Smad2/3, p-Smad2/3, transforming growth factor β (TGF-β) receptor I, and α-smooth muscle actin (α-SMA) was assayed. Pathological manifestation of hepatic tissue was assessed for the degree of liver fibrosis in animals. The results showed that CGA could inhibit the mRNA expression of miR-21, promote Smad7, and inhibit CTGF mRNA expression. Meanwhile, CGA could significantly lower the protein levels of CTGF, p-Smad1, p-Smad2, p-Smad2/3, TGF-β receptor I, and α-SMA and elevate the Smad7 protein level. In vivo, with treatment with CGA, the signaling molecules of IL-13/miR-21/Smad7 interactions were markedly regulated. CGA could also reduce the degree of liver fibrosis in pathological manifestations. In conclusion, CGA could inhibit schistosomiasis-induced hepatic fibrosis through IL-13/miR-21/Smad7 signaling interactions in LX2 cells and schistosome-infected mice and might serve as an antifibrosis agent for treating schistosomiasis liver fibrosis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samir Sissaoui ◽  
Stuart Egginton ◽  
Ling Ting ◽  
Asif Ahmed ◽  
Peter W. Hewett

AbstractPlacenta growth factor (PlGF) is a pro-inflammatory angiogenic mediator that promotes many pathologies including diabetic complications and atherosclerosis. Widespread endothelial dysfunction precedes the onset of these conditions. As very little is known of the mechanism(s) controlling PlGF expression in pathology we investigated the role of hyperglycaemia in the regulation of PlGF production in endothelial cells. Hyperglycaemia stimulated PlGF secretion in cultured primary endothelial cells, which was suppressed by IGF-1-mediated PI3K/Akt activation. Inhibition of PI3K activity resulted in significant PlGF mRNA up-regulation and protein secretion. Similarly, loss or inhibition of Akt activity significantly increased basal PlGF expression and prevented any further PlGF secretion in hyperglycaemia. Conversely, constitutive Akt activation blocked PlGF secretion irrespective of upstream PI3K activity demonstrating that Akt is a central regulator of PlGF expression. Knock-down of the Forkhead box O-1 (FOXO1) transcription factor, which is negatively regulated by Akt, suppressed both basal and hyperglycaemia-induced PlGF secretion, whilst FOXO1 gain-of-function up-regulated PlGF in vitro and in vivo. FOXO1 association to a FOXO binding sequence identified in the PlGF promoter also increased in hyperglycaemia. This study identifies the PI3K/Akt/FOXO1 signalling axis as a key regulator of PlGF expression and unifying pathway by which PlGF may contribute to common disorders characterised by endothelial dysfunction, providing a target for therapy.


2017 ◽  
Vol 68 (4) ◽  
pp. 326-329
Author(s):  
Piotr Barć ◽  
Tomasz Płonek ◽  
Dagmara Baczyńska ◽  
Artur Pupka ◽  
Wojciech Witkiewicz ◽  
...  

2013 ◽  
Vol 815 ◽  
pp. 345-349 ◽  
Author(s):  
Ching Wen Hsu ◽  
Ping Liu ◽  
Song Song Zhu ◽  
Feng Deng ◽  
Bi Zhang

Here we reported a combined technique for articular cartilage repair, consisting of bone arrow mesenchymal stem cells (BMMSCs) and poly (dl-lactide-co-glycolide-b-ethylene glycol-b-dl-lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymers carried with tissue growth factor (TGF-belat1). In the present study, BMMSCs seeded on PLGA-PEG-PLGA with were incubated in vitro, carried or not TGF-belta1, Then the effects of the composite on repair of cartilage defect were evaluated in rabbit knee joints in vivo. Full-thickness cartilage defects (diameter: 5 mm; depth: 3 mm) in the patellar groove were either left empty (n=18), implanted with BMMSCs/PLGA (n=18), TGF-belta1 modified BMMSCs/PLGA-PEG-PLGA. The defect area was examined grossly, histologically at 6, 24 weeks postoperatively. After implantation, the BMMSCs /PLGA-PEG-PLGA with TGF-belta1 group showed successful hyaline-like cartilage regeneration similar to normal cartilage, which was superior to the other groups using gross examination, qualitative and quantitative histology. These findings suggested that a combination of BMMSCs/PLGA-PEG-PLGA carried with tissue growth factor (TGF-belat1) may be an alternative treatment for large osteochondral defects in high loading sites.


2002 ◽  
pp. 795-802 ◽  
Author(s):  
F Fallo ◽  
V Pezzi ◽  
L Barzon ◽  
P Mulatero ◽  
F Veglio ◽  
...  

BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.


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