Endotoxin and CD14 in the progression of biliary atresia

<p>Abstract</p> <p>Background</p> <p>Biliary atresia (BA) is a typical cholestatic neonatal disease, characterized by obliteration of intra- and/or extra-hepatic bile ducts. However, the mechanisms contributing to the pathogenesis of BA remain uncertain. Because of decreased bile flow, infectious complications and damaging endotoxemia occur frequently in patients with BA. The aim of this study was to investigate endotoxin levels in patients with BA and the relation of these levels with the expression of the endotoxin receptor, CD14.</p> <p>Methods</p> <p>The plasma levels of endotoxin and soluble CD14 were measured with a pyrochrome Limulus amebocyte lysate assay and enzyme-linked immunosorbent assay in patients with early-stage BA when they received the Kasai procedure (KP), in patients who were jaundice-free post-KP and followed-up at the outpatient department, in patients with late-stage BA when they received liver transplantation, and in patients with choledochal cysts. The correlation of CD14 expression with endotoxin levels in rats following common bile duct ligation was investigated.</p> <p>Results</p> <p>The results demonstrated a significantly higher hepatic CD14 mRNA and soluble CD14 plasma levels in patients with early-stage BA relative to those with late-stage BA. However, plasma endotoxin levels were significantly higher in both the early and late stages of BA relative to controls. In rat model, the results demonstrated that both endotoxin and CD14 levels were significantly increased in liver tissues of rats following bile duct ligation.</p> <p>Conclusions</p> <p>The significant increase in plasma endotoxin and soluble CD14 levels during BA implies a possible involvement of endotoxin stimulated CD14 production by hepatocytes in the early stage of BA for removal of endotoxin; whereas, endotoxin signaling likely induced liver injury and impaired soluble CD14 synthesis in the late stages of BA.</p

Phyllanthus urinaria Induces Apoptosis in Human Osteosarcoma 143B Cells via Activation of Fas/FasL- and Mitochondria-Mediated Pathways

Phyllanthus urinaria (P. urinaria), in this study, was used for the treatment of human osteosarcoma cells, which is one of the tough malignancies with few therapeutic modalities. Herein, we demonstrated that P. urinaria inhibited human osteosarcoma 143B cells growth through an apoptotic extrinsic pathway to activate Fas receptor/ligand expression. Both intracellular and mitochondrial reactive oxygen species were increased to lead to alterations of mitochondrial membrane permeability and Bcl-2 family including upregulation of Bid, tBid, and Bax and downregulation of Bcl-2. P. urinaria triggered an intrinsic pathway and amplified the caspase cascade to induce apoptosis of 143B cells. However, upregulation of both intracellular and mitochondrial reactive oxygen species and the sequential membrane potential change were less pronounced in the mitochondrial respiratory-defective 143Bρ0 cells compared with the 143B cells. This study offers the evidence that mitochondria are essential for the anticancer mechanism induced by P. urinaria through both extrinsic and intrinsic pathways

Effects of Hepatocyte CD14 Upregulation during Cholestasis on Endotoxin Sensitivity

Cholestasis is frequently related to endotoxemia and inflammatory response. Our previous investigation revealed a significant increase in plasma endotoxin and CD14 levels during biliary atresia. We therefore propose that lipopolysacharides (LPS) may stimulate CD14 production in liver cells and promote the removal of endotoxins. The aims of this study are to test the hypothesis that CD14 is upregulated by LPS and investigate the pathophysiological role of CD14 production during cholestasis. Using Western blotting, qRT-PCR, and promoter activity assay, we demonstrated that LPS was associated with a significant increase in CD14 and MD2 protein and mRNA expression and CD14 promoter activity in C9 rat hepatocytes but not in the HSC-T6 hepatic stellate cell line in vitro. To correlate CD14 expression and endotoxin sensitivity, in vivo biliary LPS administration was performed on rats two weeks after they were subjected to bile duct ligation (BDL) or a sham operation. CD14 expression and endotoxin levels were found to significantly increase after LPS administration in BDL rats. These returned to basal levels after 24 h. In contrast, although endotoxin levels were increased in sham-operated rats given LPS, no increase in CD14 expression was observed. However, mortality within 24 h was more frequent in the BDL animals than in the sham-operated group. In conclusion, cholestasis and LPS stimulation were here found to upregulate hepatic CD14 expression, which may have led to increased endotoxin sensitivity and host proinflammatory reactions, causing organ failure and death in BDL rats

2-Deoxyglucose treatment complements the cisplatin- or BH3-only mimetic-induced suppression of neuroblastoma cell growth

Neuroblastoma (NB) is characterized by pleomorphic molecular characteristics, which may influence cellular metabolism as well as the efficacy of glycolytic inhibitors in suppressing NB cell growth. We studied the metabolic profile of four NB cell lines without or with MYCN amplification and found no unanimous metabolic characteristics. The two NB cell lines with MYCN amplification exhibited a significantly higher HIF-1 alpha expression level and ATP content compared to the two cell lines without MYCN amplification. MYCN amplification was associated with significantly greater inhibition of cellular proliferation and more apoptosis after treatment with the glycolytic inhibitor 2-deoxyglucose (2DG). Further analysis showed that 2DG increased PDK1 but decreased the ATP content and increased expression of the proapoptotic BH3-only protein Bad in both SK-N-AS (without MYCN amplification) and SK-N-DZ (with MYCN amplification) cells. In addition, 2DG decreased hexokinase II expression in SK-N-DZ cells and increased HIF-1 alpha, Noxa, and PUMA expression in SK-N-AS cells. Pretreating SK-N-DZ cells with 2DG or cisplatin for 24h, followed by cisplatin or 2DG for another 24h, resulted in significantly greater suppression of cellular proliferation compared to treatment with 2DG or cisplatin for 48 h alone. Effective suppression of SK-N-AS proliferation occurred only when the cells were pretreated with cisplatin. Pretreatment of SK-N-DZ, but not SK-N-AS, with 2DG followed by the BH3-only mimetic ABT737 also resulted in significantly greater suppression of cellular proliferation compared to treatment with ABT737 or 2DG alone. A low dose of 2DG (2 mM) was as effective as a high dose (20 mM) in SK-N-DZ cells. In conclusion, the glycolytic inhibitor 2DG complemented the cisplatin- or ABT737-induced suppression of growth in NB cells, which are sensitive to glycolytic inhibition. (C) 2013 Elsevier Ltd. All rights reserved

2-Deoxyglucose treatment complements the cisplatin- or BH3-onlymimetic-induced suppression of neuroblastoma cell growth (vol 45, pg 944, 2013)

Neuroblastoma (NB) is characterized by pleomorphic molecular characteristics, which may influence cellular metabolism as well as the efficacy of glycolytic inhibitors in suppressing NB cell growth. We studied the metabolic profile of four NB cell lines without or with MYCN amplification and found no unanimous metabolic characteristics. The two NB cell lines with MYCN amplification exhibited a significantly higher HIF-1 alpha expression level and ATP content compared to the two cell lines without MYCN amplification. MYCN amplification was associated with significantly greater inhibition of cellular proliferation and more apoptosis after treatment with the glycolytic inhibitor 2-deoxyglucose (2DG). Further analysis showed that 2DG increased PDK1 but decreased the ATP content and increased expression of the proapoptotic BH3-only protein Bad in both SK-N-AS (without MYCN amplification) and SK-N-DZ (with MYCN amplification) cells. In addition, 2DG decreased hexokinase II expression in SK-N-DZ cells and increased HIF-1 alpha, Noxa, and PUMA expression in SK-N-AS cells. Pretreating SK-N-DZ cells with 2DG or cisplatin for 24h, followed by cisplatin or 2DG for another 24h, resulted in significantly greater suppression of cellular proliferation compared to treatment with 2DG or cisplatin for 48 h alone. Effective suppression of SK-N-AS proliferation occurred only when the cells were pretreated with cisplatin. Pretreatment of SK-N-DZ, but not SK-N-AS, with 2DG followed by the BH3-only mimetic ABT737 also resulted in significantly greater suppression of cellular proliferation compared to treatment with ABT737 or 2DG alone. A low dose of 2DG (2 mM) was as effective as a high dose (20 mM) in SK-N-DZ cells. In conclusion, the glycolytic inhibitor 2DG complemented the cisplatin- or ABT737-induced suppression of growth in NB cells, which are sensitive to glycolytic inhibition. (C) 2013 Elsevier Ltd. All rights reserved

ONC201 Suppresses Neuroblastoma Growth by Interrupting Mitochondrial Function and Reactivating Nuclear ATRX Expression While Decreasing MYCN

Neuroblastoma (NB) is characterized by several malignant phenotypes that are difficult to treat effectively without combination therapy. The therapeutic implication of mitochondrial ClpXP protease ClpP and ClpX has been verified in several malignancies, but is unknown in NB. Firstly, we observed a significant increase in ClpP and ClpX expression in immature and mature ganglion cells as compared to more malignant neuroblasts and less malignant Schwannian-stroma-dominant cell types in human neuroblastoma tissues. We used ONC201 targeting ClpXP to treat NB cells, and found a significant suppression of mitochondrial protease, i.e., ClpP and ClpX, expression and downregulation of mitochondrial respiratory chain subunits SDHB and NDUFS1. The latter was associated with a state of energy depletion, increased reactive oxygen species, and decreased mitochondrial membrane potential, consequently promoting apoptosis and suppressing cell growth of NB. Treatment of NB cells with ONC201 as well as the genetic attenuation of ClpP and ClpX through specific short interfering RNA (siRNA) resulted in the significant upregulation of the tumor suppressor alpha thalassemia/mental retardation X-linked (ATRX) and promotion of neurite outgrowth, implicating mitochondrial ClpXP proteases in MYCN-amplified NB cell differentiation. Furthermore, ONC201 treatment significantly decreased MYCN protein expression and suppressed tumor formation with the reactivation of ATRX expression in MYCN-amplified NB-cell-derived xenograft tumors. Taken together, ONC201 could be the potential agent to provide diversified therapeutic application in NB, particularly in NB with MYCN amplification

Upregulation of TLRs and IL-6 as a Marker in Human Colorectal Cancer

Toll-like receptors (TLRs) not only form an important part of the innate immune system but also serve to activate the adaptive immune system in response to cancer. Real-time PCR; immunohistochemical stain and Western blotting analyses were performed to clarify molecular alterations in colorectal cancer (CRC) patients. We identified Toll-like receptor 1 (TLR1), TLR2, TLR4 and TLR8 gene expression levels and downstream gene, i.e., interleukin-6 (IL-6), IL-8, interferon-α (IFN-α) and myeloid differentiation primary-response protein-88 (MyD88), expression levels in CRC patients and in cancer cell lines. CRC tissues have higher TLR1, TLR2, TLR4, TLR8, IL-6 and IL-8 gene expression levels than do the normal colon mucosa (p &lt; 0.05). TLR2 expression varied in different cell types (mucosa and lymphocytes). There was no difference in the MyD88 and IFN-α gene expression levels between cancerous and normal colon mucosa. CRC patients had higher levels of IL-6 (p = 0.002) and IL-8 (p = 0.038) expression than healthy volunteers did; and higher IL-6 and IL-8 expression was also found to signify a higher risk of recurrence. CL075 (3M002) treatments can reduce the production of IL-8 in different cancer cell lines. The signaling pathway of TLRs in cancer tissue is different from that in normal cells; and is MyD88-independent. Higher expression levels of TLR1, TLR2, TLR 4 and TLR 8 mRNA were related to upregulation inflammatory cytokines IL-6 and IL-8 gene expression in tissue and to the upregulation of IL-6 in blood. The concentration of IL-6 in serum can be used as an indicator of the possibility of CRC recurrence. Treatment with 3M002 can reduce IL-6 production in vitro and may prevent CRC recurrence. Our findings provide evidence that TLR1, TLR2, TLR4 and TLR8 gene expression induce downstream IL-6 and IL-8 gene expression; detection of these expression levels can serve as a CRC marker

Microarray Study of Pathway Analysis Expression Profile Associated with MicroRNA-29a with Regard to Murine Cholestatic Liver Injuries

Accumulating evidence demonstrates that microRNA-29 (miR-29) expression is prominently decreased in patients with hepatic fibrosis, which consequently stimulates hepatic stellate cells’ (HSCs) activation. We used a cDNA microarray study to gain a more comprehensive understanding of genome-wide gene expressions by adjusting miR-29a expression in a bile duct-ligation (BDL) animal model. Methods: Using miR-29a transgenic mice and wild-type littermates and applying the BDL mouse model, we characterized the function of miR-29a with regard to cholestatic liver fibrosis. Pathway enrichment analysis and/or specific validation were performed for differentially expressed genes found within the comparisons. Results: Analysis of the microarray data identified a number of differentially expressed genes due to the miR-29a transgene, BDL, or both. Additional pathway enrichment analysis revealed that TGF-β signaling had a significantly differential activated pathway depending on the occurrence of miR-29a overexpression or the lack thereof. Furthermore, overexpression was found to elicit changes in Wnt/β-catenin after BDL. Conclusion: This study verified that an elevated miR-29a level could alleviate liver fibrosis caused by cholestasis. Furthermore, the protective effects of miR-29a correlate with the downregulation of TGF-β and associated with Wnt/β-catenin signal pathway following BDL