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1

The membrane peroxin PEX3 induces peroxisome-ubiquitination-linked pexophagy.  

PubMed

Peroxisomes are degraded by a selective type of autophagy known as pexophagy. Several different types of pexophagy have been reported in mammalian cells. However, the mechanisms underlying how peroxisomes are recognized by autophagy-related machinery remain elusive. PEX3 is a peroxisomal membrane protein (PMP) that functions in the import of PMPs into the peroxisomal membrane and has been shown to interact with pexophagic receptor proteins during pexophagy in yeast. Thus, PEX3 is important not only for peroxisome biogenesis, but also for peroxisome degradation. However, whether PEX3 is involved in the degradation of peroxisomes in mammalian cells is unclear. Here, we report that high levels of PEX3 expression induce pexophagy. In PEX3-loaded cells, peroxisomes are ubiquitinated, clustered, and degraded in lysosomes. Peroxisome targeting of PEX3 is essential for the initial step of this degradation pathway. The degradation of peroxisomes is inhibited by treatment with autophagy inhibitors or siRNA against NBR1, which encodes an autophagic receptor protein. These results indicate that ubiquitin- and NBR1-mediated pexophagy is induced by increased expression of PEX3 in mammalian cells. In addition, another autophagic receptor protein, SQSTM1/p62, is required only for the clustering of peroxisomes. Expression of a PEX3 mutant with substitution of all lysine and cysteine residues by arginine and alanine, respectively, also induces peroxisome ubiquitination and degradation, hence suggesting that ubiquitination of PEX3 is dispensable for pexophagy and an endogenous, unidentified peroxisomal protein is ubiquitinated on the peroxisomal membrane. PMID:25007327

Yamashita, Shun-ichi; Abe, Kakeru; Tatemichi, Yuki; Fujiki, Yukio

2014-09-01

2

Peroxisome proliferators induce apoptosis in hepatoma cells.  

PubMed

In the AH-130 hepatoma, a poorly differentiated tumor, maintained by weekly transplantations in rats, a low percentage of cells spontaneously underwent apoptosis, mainly during the transition from logarithmic- to stationary-growth phase. It was possible to induce massive apoptosis of cells by treating them with clofibrate, a peroxisome proliferator and hypolipidemic drug. Similar results were obtained with HepG2 cells. With 1 mM clofibrate, apoptosis began to manifest itself after 1 h of treatment in vitro, and was assessed by morphological analysis, by DNA fragmentation carried out with agarose gel electrophoresis, and with flow cytometric determination of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling. The mechanisms whereby clofibrate induces apoptosis are still unclear. Since the peroxisome proliferator-activated receptor was expressed at a very low level and was not stimulated by clofibrate in the AH-130 hepatoma cells, its involvement seems unlikely. Moreover, lipid peroxidation was not increased after clofibrate treatment. Phospholipids and cholesterol were significantly decreased. The decreased cholesterol content might suggest an inhibition of the mevalonate pathway and, therefore, of isoprenylation of proteins involved in cell proliferation. PMID:9674879

Canuto, R A; Muzio, G; Bonelli, G; Maggiora, M; Autelli, R; Barbiero, G; Costelli, P; Brossa, O; Baccino, F M

1998-01-01

3

NADH induces the generation of superoxide radicals in leaf peroxisomes. [Pisum sativum L  

SciTech Connect

In peroxisomes isolated from pea leaves (Pisum sativum L.) the production of superoxide free radicals (O{sub 2}{sup {minus}}) by xanthine and NADH was investigated. In peroxisomal membranes, 100 micromolar NADH induced the production of O{sub 2}{sup {minus}} radicals. In the soluble fractions of peroxisomes, no generation of O{sub 2}{sup {minus}} radicals was observed by incubation with either NADH or xanthine, although xanthine oxidase was found located predominantly in the matrix of peroxisomes. The failure of xanthine to induce superoxide generation was probably due to the inability to fully suppress the endogenous Mn-superoxide dismutase activity by inhibitors which were inactive against xanthine oxidase. The generation of superoxide radicals in leaf peroxisomes together with the recently described production of these oxygen radicals in glyoxysomes suggests that O{sub 2}{sup {minus}} generation could be a common metabolic property of peroxisomes and further supports the existence of active oxygen-related roles for peroxisomes in cellular metabolism.

del Rio, L.A.; Sandalio, L.M.; Palma, J.M. (Unidad de Bioquimica Vegetal, Granada (Spain)); Fernandez, V.M.; Ruperez, F.L. (Instituto de Catalisis, Madrid (Spain))

1989-03-01

4

HYDROGEN PEROXIDE INDUCED OXIDATION OF PEROXISOMAL MALATE SYNTHASE AND CATALASE.  

E-print Network

Page 1 HYDROGEN PEROXIDE INDUCED OXIDATION OF PEROXISOMAL MALATE SYNTHASE AND CATALASE. Pria Anand1-6100 E-mail: robdon@gwu.edu Short title: Oxidation of Peroxisomal Malate Synthase and Catalase * Revised Manuscript (Unmarked) Click here to view linked References #12;Page 2 Abbreviations CAT , catalase; MS

Simha, Rahul

5

Dysfunction of peroxisomes in twitcher mice brain: A possible mechanism of psychosine-induced disease  

SciTech Connect

Psychosine (galactosylsphingosine) accumulates in Brain of Krabbe disease (KD) patients as well as twitcher mice, a murine model of KD, resulting in loss of oligodendrocytes and myelin. This study documents progressive loss of peroxisomal proteins/functions and induction of expression of inflammatory cytokine TNF-{alpha} in twitcher brain. The observed decrease in peroxisomal proteins was accompanied by decreased level of peroxisome proliferator-activated receptor-alpha (PPAR-{alpha}), one of the transcription factors required for expression of peroxisomal protein genes. The role of psychosine in down-regulation of PPAR-{alpha} activity was further supported by decreased PPAR-{alpha} mediated PPRE transcriptional activity in cells transfected with PPAR-{alpha} and PPRE reporters. The psychosine-induced down-regulation of PPAR activity and cell death was attenuated by sPLA{sub 2} inhibitor. Therefore, this study provides First evidence of peroxisomal abnormality in a lysosomal disorder, suggesting that such dysfunction of peroxisomes may play a role in the pathogenesis of Krabbe disease.

Haq, Ehtishamul [Department of Pediatrics and The Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425 (United States); Contreras, Miguel A. [Department of Pediatrics and The Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425 (United States); Giri, Shailendra [Department of Pediatrics and The Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425 (United States); Singh, Inderjit [Department of Pediatrics and The Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425 (United States); Singh, Avtar K. [Department of Pathology and Laboratory Medicine, Medical University of South Carolina and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29425 (United States)]. E-mail: singha@musc.edu

2006-04-28

6

An overview of peroxisome proliferator-induced hepatocarcinogenesis.  

PubMed

Peroxisome proliferators are hepatocarcinogens in rats and mice. Chronic administration of these compounds results in the development of altered areas and neoplastic nodules followed by hepatocellular carcinomas. All three types of hepatic lesions do not express gamma-glutamyltranspeptidase, glutathione 8-transferase-P, and alpha-fetoprotein and are resistant to iron accumulation after overload. The mechanism by which nongenotoxic peroxisome proliferators induce hepatic tumors is not well understood. It has been proposed that with continuous administration of peroxisome proliferators, liver cells are subjected to persistent oxidative stress resulting from marked proliferation of peroxisomes and a differential increase in the levels of H2O2 producing (20- to 30-fold) and degrading (2-fold) enzymes. Free oxygen radicals lead to DNA damage (both directly and through lipid peroxidation) and thus may cause initiation and promotion of the carcinogenic process. PMID:1685443

Rao, M S; Reddy, J K

1991-06-01

7

PPAR? activation induces N(?)-Lys-acetylation of rat liver peroxisomal multifunctional enzyme type 1.  

PubMed

Peroxisomes are ubiquitous subcellular organelles that participate in metabolic and disease processes, with few of its proteins undergoing posttranslational modifications. As the role of lysine-acetylation has expanded into the cellular intermediary metabolism, we used a combination of differential centrifugation, organelle isolation by linear density gradient centrifugation, western blot analysis, and peptide fingerprinting and amino acid sequencing by mass spectrometry to investigate protein acetylation in control and ciprofibrate-treated rat liver peroxisomes. Organelle protein samples isolated by density gradient centrifugation from PPAR?-agonist treated rat liver screened with an anti-N(?)-acetyl lysine antibody revealed a single protein band of 75 kDa. Immunoprecipitation with this antibody resulted in the precipitation of a protein from the protein pool of ciprofibrate-induced peroxisomes, but not from the protein pool of non-induced peroxisomes. Peptide mass fingerprinting analysis identified the protein as the peroxisomal multifunctional enzyme type 1. In addition, mass spectrometry-based amino acid sequencing resulted in the identification of unique peptides containing 4 acetylated-Lys residues (K¹??, K¹?³, K¹??, and K??³). This is the first report that demonstrates posttranslational acetylation of a peroxisomal enzyme in PPAR?-dependent proliferation of peroxisomes in rat liver. PMID:24092543

Contreras, Miguel A; Alzate, Oscar; Singh, Avtar K; Singh, Inderjit

2014-02-01

8

The Requirement of Sterol Glucoside for Pexophagy in Yeast Is Dependent on the Species and Nature of Peroxisome Inducers  

PubMed Central

Sterol glucosyltransferase, Ugt51/Atg26, is essential for both micropexophagy and macropexophagy of methanol-induced peroxisomes in Pichia pastoris. However, the role of this protein in pexophagy in other yeast remained unclear. We show that oleate- and amine-induced peroxisomes in Yarrowia lipolytica are degraded by Atg26-independent macropexophagy. Surprisingly, Atg26 was also not essential for macropexophagy of oleate- and amine-induced peroxisomes in P. pastoris, suggesting that the function of sterol glucoside (SG) in pexophagy is both species and peroxisome inducer specific. However, the rates of degradation of oleate- and amine-induced peroxisomes in P. pastoris were reduced in the absence of SG, indicating that P. pastoris specifically uses sterol conversion by Atg26 to enhance selective degradation of peroxisomes. However, methanol-induced peroxisomes apparently have lost the redundant ability to be degraded without SG. We also show that the P. pastoris Vac8 armadillo repeat protein is not essential for macropexophagy of methanol-, oleate-, or amine-induced peroxisomes, which makes PpVac8 the first known protein required for the micropexophagy, but not for the macropexophagy, machinery. The uniqueness of Atg26 and Vac8 functions under different pexophagy conditions demonstrates that not only pexophagy inducers, such as glucose or ethanol, but also the inducers of peroxisomes, such as methanol, oleate, or primary amines, determine the requirements for subsequent pexophagy in yeast. PMID:17079731

Nazarko, Taras Y.; Polupanov, Andriy S.; Manjithaya, Ravi R.; Sibirny, Andriy A.

2007-01-01

9

Molecular basis of non-responsiveness to peroxisome proliferators: the guinea-pig PPARalpha is functional and mediates peroxisome proliferator-induced hypolipidaemia.  

PubMed Central

The guinea pig does not undergo peroxisome proliferation in response to peroxisome proliferators, in contrast with other rodents. To understand the molecular basis of this phenotype, the peroxisome proliferator activated receptor alpha (PPARalpha) from guinea-pig liver was cloned; it encodes a protein of 467 amino acid residues that is similar to rodent and human PPARalpha. The guinea-pig PPARalpha showed a high substitution rate: maximum likelihood analysis was consistent with rodent monophyly, but could not exclude rodent polyphyly (P approximately 0.06). The guinea-pig PPARalpha cDNA was expressed in 293 cells and mediated the induction of the luciferase reporter gene by the peroxisome proliferator, Wy-14,643, dependent on the presence of a peroxisome proliferator response element. Moreover the PPARalpha RNA and protein were expressed in guinea-pig liver, although at lower levels than in a species which is responsive to peroxisome proliferators, the mouse. To determine whether the guinea-pig PPARalpha mediated any physiological effects, guinea pigs were exposed to two selective PPARalpha agonists, Wy-14, 643 and methylclofenapate; both compounds induced hypolipidaemia. Thus the guinea pig is a useful model for human responses to peroxisome proliferators. PMID:9620871

Bell, A R; Savory, R; Horley, N J; Choudhury, A I; Dickins, M; Gray, T J; Salter, A M; Bell, D R

1998-01-01

10

Peroxisome proliferator-activated receptor ? confers resistance to peroxisome proliferator-activated receptor ?-induced apoptosis in colorectal cancer cells  

PubMed Central

Peroxisome proliferator-activated receptor ? (PPAR?) may serve as a useful target for drug development in non-diabetic diseases. However, some colorectal cancer cells are resistant to PPAR? agonists by mechanisms that are poorly understood. Here we provide the first evidence that elevated PPAR? expression and/or activation of PPAR? antagonize the ability of PPAR? to induce colorectal carcinoma cell death. More importantly, the opposing effects of PPAR? and PPAR? in regulating programmed cell death are mediated by survivin and caspase-3. We found that activation of PPAR? results in decreased survivin expression and increased caspase-3 activity, whereas activation of PPAR? counteracts these effects. Our findings suggest that PPAR? and PPAR? coordinately regulate cancer cell fate by controlling the balance between the cell death and survival and demonstrate that inhibition of PPAR? can reprogram PPAR? ligand-resistant cells to respond to PPAR? agonists. PMID:21765467

Wang, Dingzhi; Ning, Wei; Xie, Dianren; Guo, Lixia; DuBois, Raymond N.

2014-01-01

11

Peroxisome Proliferator-Activated Receptor Protects Against Alcohol-Induced Liver Damage  

E-print Network

Peroxisome Proliferator-Activated Receptor Protects Against Alcohol-Induced Liver Damage Tamie alcoholic liver disease are not completely understood, but lipid accumulation seems to be central. To investi- gate the roles of PPAR in alcoholic liver injury, wild-type and PPAR -null mice were continuously

Omiecinski, Curtis

12

Peroxisome proliferator-activated receptor y (PPARy) activation protects H9c2 cardiomyoblasts from oxidative stress-induced apoptosis  

Microsoft Academic Search

Objective: Activation of peroxisome proliferator-activated receptor a (PPARa) and PPARg plays beneficial roles in cardiovascular disorders such as atherosclerosis and heart reperfusion. Although PPARa and g have been documented to reduce oxidative stress in the vasculature and the heart, the role of PPARy remains poorly studied. Methods and results: We focused on PPARy function in the regulation of oxidative stress-induced

Matthieu Pesant; Stephanie Sueur; Patrick Dutartre; Mireille Tallandier; Paul A. Grimaldi; Luc Rochette; Jean-Louis Connat

2006-01-01

13

Histone Deacetylase Inhibitor Upregulates Peroxisomal Fatty Acid Oxidation and Inhibits Apoptotic Cell Death in Abcd1-Deficient Glial Cells  

PubMed Central

In X-ALD, mutation/deletion of ALD gene (ABCD1) and the resultant very long chain fatty acid (VLCFA) derangement has dramatically opposing effects in astrocytes and oligodendrocytes. While loss of Abcd1 in astrocytes produces a robust inflammatory response, the oligodendrocytes undergo cell death leading to demyelination in X-linked adrenoleukodystrophy (X-ALD). The mechanisms of these distinct pathways in the two cell types are not well understood. Here, we investigated the effects of Abcd1-knockdown and the subsequent alteration in VLCFA metabolism in human U87 astrocytes and rat B12 oligodendrocytes. Loss of Abcd1 inhibited peroxisomal ?-oxidation activity and increased expression of VLCFA synthesizing enzymes, elongase of very long chain fatty acids (ELOVLs) (1 and 3) in both cell types. However, higher induction of ELOVL's in Abcd1-deficient B12 oligodendrocytes than astrocytes suggests that ELOVL pathway may play a prominent role in oligodendrocytes in X-ALD. While astrocytes are able to maintain the cellular homeostasis of anti-apoptotic proteins, Abcd1-deletion in B12 oligodendrocytes downregulated the anti-apototic (Bcl-2 and Bcl-xL) and cell survival (phospho-Erk1/2) proteins, and upregulated the pro-apoptotic proteins (Bad, Bim, Bax and Bid) leading to cell loss. These observations provide insights into different cellular signaling mechanisms in response to Abcd1-deletion in two different cell types of CNS. The apoptotic responses were accompanied by activation of caspase-3 and caspase-9 suggesting the involvement of mitochondrial-caspase-9-dependent mechanism in Abcd1-deficient oligodendrocytes. Treatment with histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) corrected the VLCFA derangement both in vitro and in vivo, and inhibited the oligodendrocytes loss. These observations provide a proof-of principle that HDAC inhibitor SAHA may have a therapeutic potential for X-ALD. PMID:23923017

Singh, Jaspreet; Khan, Mushfiquddin; Pujol, Aurora; Baarine, Mauhamad; Singh, Inderjit

2013-01-01

14

The role of NF-?B in SAA-induced peroxisome proliferator-activated receptor ? activation.  

PubMed

Serum amyloid A (SAA) is an acute phase protein whose expression increases markedly during bacterial infection, tissue damage, and inflammation. The potential beneficial roles of SAA include its involvement in the reverse cholesterol transport and possibly extracellular lipid deposition at sites of inflammation and tissue repair. It is an attractive therapeutic target for the treatment of atherosclerosis. Peroxisome proliferator-activated receptor ? (PPAR?) plays a major regulatory role in adipogenesis, and the expression of genes involved in lipid metabolism. Activation of PPAR? leads to multiple changes in gene expression, some of which are believed to be atherogenic while others are antiatherogenic. In this study, we demonstrated that SAA upregulated COX-2 expression and induced PPAR? activity through NF-?B pathway. The effect of SAA on NF-?B activity is mediated by FPRL-1 and TLR4. PMID:23340376

Li, Hongzhe; Ooi, Shu Qin; Heng, Chew-Kiat

2013-03-01

15

Chemical synthesis, docking studies and biological effects of a pan peroxisome proliferator-activated receptor agonist and cyclooxygenase inhibitor.  

PubMed

The compound (5Z)-5-[(5-bromo-1H-indol-3-yl)methylene]-3-(4-chlorobenzyl)-thiazolidine-2,4-dione (LYSO-7) was synthesised in order to obtain a new type of anti-inflammatory drug, designed with hybrid features to inhibit cyclooxygenase (COX) and also to activate peroxisome proliferator-activated receptor (PPAR). Results obtained from docking (in silico) studies corroborated with experimental data, showing the potential affinity between the studied ligand and targets. The specificity of LYSO-7 for COX-enzymes was detected by the inhibition of COX-1 and COX-2 activities by 30% and 20%, respectively. In transactivation reporter gene assays LYSO-07 showed a pan partial agonist effect on the three PPAR subtypes (PPAR?, PPAR? and PPAR?/?). The agonist action on PPAR? was also observed by a pharmacological approach, as the reduction in the Escherichia coli lipopolysaccharide (LPS)-induced interleukin 1 beta (IL-1?) secretion and nitric oxide (NO) production by mouse neutrophils was blocked by GW9962, a specific PPAR? antagonist. Additionally, the in vivo effect was measured by reduced carrageenan-induced neutrophil influx into the subcutaneous tissue of mice. Taken together, these data show that LYSO-7 displays a potent in vivo anti-inflammatory effect during the innate acute response, which is dependent on its associated COX inhibitory activities and PPAR activation. PMID:23305993

Santin, José Roberto; Uchôa, Flávia D T; Lima, Maria do Carmo A; Rabello, Marcelo M; Machado, Isabel Daufenback; Hernandes, Marcelo Z; Amato, Angelica A; Milton, Flora Aparecida; Webb, Paul; Neves, Francisco de Assis Rocha; Galdino, Suely L; Pitta, Ivan Rocha; Farsky, Sandra H P

2013-03-12

16

Conjugated linoleic acid activates peroxisome proliferator-activated receptor ? and ? subtypes but does not induce hepatic peroxisome proliferation in Sprague–Dawley rats  

Microsoft Academic Search

Since conjugated linoleic acid (CLA) has structural and physiological characteristics similar to peroxisome proliferators, we hypothesized that CLA would activate peroxisome proliferator-activated receptor (PPAR). We compared the effects of dietary CLA (0.0, 0.5, 1.0 and 1.5% by weight) with a peroxisome proliferator (0.01% Wy-14,643) in female and male Sprague–Dawley (SD) rats. Dietary CLA had little effect on body weight, liver

Silvia Y Moya-Camarena; John P Vanden Heuvel; Martha A Belury

1999-01-01

17

Fenofibrate, a peroxisome proliferator-activated receptor ? ligand, prevents abnormal liver function induced by a fasting–refeeding process  

SciTech Connect

Highlights: •A fasting–refeeding high fat diet (HDF) model mimics irregular eating habit. •A fasting–refeeding HFD induces liver ballooning injury. •A fasting–refeeding HDF process elicits hepatic triglyceride accumulation. •Fenofibrate, PPAR? ligand, prevents liver damage induced by refeeding HFD. -- Abstract: Fenofibrate, a peroxisome proliferator-activated receptor ? (PPAR?) agonist, is an anti-hyperlipidemic agent that has been widely used in the treatment of dyslipidemia. In this study, we examined the effect of fenofibrate on liver damage caused by refeeding a high-fat diet (HFD) in mice after 24 h fasting. Here, we showed that refeeding HFD after fasting causes liver damage in mice determined by liver morphology and liver cell death. A detailed analysis revealed that hepatic lipid droplet formation is enhanced and triglyceride levels in liver are increased by refeeding HFD after starvation for 24 h. Also, NF-?B is activated and consequently induces the expression of TNF-?, IL1-?, COX-2, and NOS2. However, treating with fenofibrate attenuates the liver damage and triglyceride accumulation caused by the fasting–refeeding HFD process. Fenofibrate reduces the expression of NF-?B target genes but induces genes for peroxisomal fatty acid oxidation, peroxisome biogenesis and mitochondrial fatty acid oxidation. These results strongly suggest that the treatment of fenofibrate ameliorates the liver damage induced by fasting–refeeding HFD, possibly through the activation of fatty acid oxidation.

Lee, Joon No; Dutta, Raghbendra Kumar; Kim, Seul-Gi; Lim, Jae-Young; Kim, Se-Jin; Choe, Seong-Kyu [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)] [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Yoo, Kyeong-Won [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of) [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Immune-network Pioneer Research Center, Department of Biochemistry, College of Medicine, Dong-A University, Busan (Korea, Republic of); Song, Seung Ryel [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)] [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Park, Do-Sim [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of) [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Department of Laboratory of Medicine, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); So, Hong-Seob [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)] [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Park, Raekil, E-mail: rkpark@wku.ac.kr [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)] [Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of)

2013-12-06

18

Methyl Jasmonate Induces Papain Inhibitor(s) in Tomato Leaves.  

PubMed Central

Leaves of 18- to 24-d-old tomato (Lycopersicon esculentum) plants exposed to gaseous methyl jasmonate (MJ) for 24 h at 30[deg]C in continuous light contained high levels of soluble protein that inhibited papain. Chromatographic analysis demonstrated that the active protein had a molecular mass of 80 to 90 kD. Induction of papain inhibitor was directly related to the concentration of air-borne MJ up to a maximum of 0.1 [mu]L MJ per treatment and depended on the duration of exposure up to 18 h. Inhibitor activity in plants treated for less than 18 h increased with time after treatment. Levels remained constant for up to 4 d after treatment, after which time activity decreased. The youngest leaf, leaf 5, consistently lost activity at a faster rate than older, lower leaves. Inhibitor concentration in all leaves was reduced to minimum levels by 11 d after MJ treatment, but did not return to control levels. Treatment with MJ in the dark did induce inhibitor activity, but at a significantly lower rate. Polyclonal antibodies raised to purified potato tuber skin cysteine proteinase inhibitors (CPI) cross-reacted with the tomato inhibitor, suggesting that the tomato papain inhibitor and the potato CPI are closely related. No papain inhibitor activity was observed in extracts from wounded tomato leaves, nor was there any immunoreactivity with antibodies raised to potato tuber skin CPI. PMID:12232028

Bolter, C. J.

1993-01-01

19

Fenofibrate A peroxisome proliferator activated receptor-? agonist treatment ameliorates Concanavalin A-induced hepatitis in rats.  

PubMed

Peroxisome proliferator-activated receptor-? (PPAR?) is physiologically highly expressed by hepatocytes, where it plays a pivotal anti-inflammatory and metabolic role. The decrease expression and functional activity of PPAR? in hepatocytes during hepatitis C virus infection may contribute to the pathogenesis of the disease in humans. This study aims at evaluating the effects of PPAR? activation with fenofibrate (FF) on liver inflammation, fibrosis and portal pressure (PP) in Concanavalin A (Con A)- induced hepatitis in rats. The rats were randomly divided to 3 groups; control (1 ml saline iv/wk) group, Con A (20mg/kg/iv/wk) group and Con A with FF (100mg/kg/day p.o) group. Blood samples and livers were collected by the end of the first, second, fourth and eighth injections of Con A for biochemical, histopathological and immunohistochemistry studies for ?-smooth muscle actin (? SMA). Measurement of PP was performed by the end of the 8th week. FF group had a significant (P<0.05) decrease of serum alanine and aspartate aminotransferases with significant reduction of hepatic tumor necrosis factor alpha and malondialdehyde levels than Con A group. Histopathological examination revealed that treatment with FF significantly suppressed early inflammation, reduced ? SMA, and apoptosis of hepatocytes induced by Con A, thereby preventing the progression of chronic liver injury and fibrosis. In addition FF group had a significantly lower PP (-89.0%) than Con A group. In conclusion PPAR? activation significantly reduced liver inflammation, fibrosis and PP in Con A model of hepatitis that may represent a new therapeutic strategy for hepatitis and its complications. PMID:24140572

Mohamed, Doaa I; Elmelegy, Ahmed A M; El-Aziz, Lubna F A; Abdel Kawy, Hala S; El-Samad, Abeer A Abd; El-Kharashi, Omnyah A

2013-12-01

20

Peroxisome Proliferator-Activated Receptor ? Activation Induces Hepatic Steatosis, Suggesting an Adverse Effect  

PubMed Central

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic triglyceride accumulation, ranging from steatosis to steatohepatitis and cirrhosis. NAFLD is a risk factor for cardiovascular diseases and is associated with metabolic syndrome. Antihyperlipidemic drugs are recommended as part of the treatment for NAFLD patients. Although fibrates activate peroxisome proliferator-activated receptor ? (PPAR?), leading to the reduction of serum triglyceride levels, the effects of these drugs on NAFLD remain controversial. Clinical studies have reported that PPAR? activation does not improve hepatic steatosis. In the present study, we focused on exploring the effect and mechanism of PPAR? activation on hepatic triglyceride accumulation and hepatic steatosis. Male C57BL/6J mice, Ppar?-null mice and HepG2 cells were treated with fenofibrate, one of the most commonly used fibrate drugs. Both low and high doses of fenofibrate were administered. Hepatic steatosis was detected through oil red O staining and electron microscopy. Notably, in fenofibrate-treated mice, the serum triglyceride levels were reduced and the hepatic triglyceride content was increased in a dose-dependent manner. Oil red O staining of liver sections demonstrated that fenofibrate-fed mice accumulated abundant neutral lipids. Fenofibrate also increased the intracellular triglyceride content in HepG2 cells. The expression of sterol regulatory element-binding protein 1c (SREBP-1c) and the key genes associated with lipogenesis were increased in fenofibrate-treated mouse livers and HepG2 cells in a dose-dependent manner. However, the effect was strongly impaired in Ppar?-null mice treated with fenofibrate. Fenofibrate treatment induced mature SREBP-1c expression via the direct binding of PPAR? to the DR1 motif of the SREBP-1c gene. Taken together, these findings indicate the molecular mechanism by which PPAR? activation increases liver triglyceride accumulation and suggest an adverse effect of fibrates on the pathogenesis of hepatic steatosis. PMID:24926685

Yan, Fang; Wang, Qi; Xu, Chao; Cao, Mingfeng; Zhou, Xiaoming; Wang, Tingting; Yu, Chunxiao; Jing, Fei; Chen, Wenbin; Gao, Ling; Zhao, Jiajun

2014-01-01

21

A peroxisomal ABC transporter promotes seed germination by inducing pectin degradation under the control of ABI5.  

PubMed

Seed dormancy is essential for most plants to control the timing of germination. In Arabidopsis thaliana, PED3 is a single-copy gene encoding an ATP-binding cassette transporter that is required for peroxisomal fatty acid beta-oxidation. PED3 is involved in the import of several biologically important molecules into the peroxisome, including very-long-chain fatty acids associated with the breakdown of seed-reserve lipids, and precursors of auxin and jasmonic acid. The germination of ped3 mutants is significantly impaired, suggesting that PED3 regulates dormancy and germination. A transcriptome analysis revealed that many genes containing the core motif of the ABA responsive element (ABRE) in their promoter regions, and the ABA insensitive 5 (ABI5) transcription factor that binds to ABRE, are abnormally up-regulated in imbibed ped3 seeds. Expression of polygalacturonase inhibiting proteins (PGIPs) is also up-regulated specifically in ped3 after imbibition. By contrast, the ped3 abi5 double mutant does not show any of these expression patterns. The results indicate that the abi5 mutation normalizes PGIP expression and rescues the impaired germination phenotype of the ped3 mutant. PGIPs are known to act as inhibitors of polygalacturonases that degrade pectin. The amount of PGIP1 transcript regulates the timing of radicle protrusion. The impaired germination of ped3 could also be rescued by removal of pectin from the seed coat using exogenous polygalacturonase or acidic conditions. Overall, our results suggest that PED3, a peroxisomal ABC transporter, promotes seed germination by suppressing PGIPs under the control of ABI5. PMID:20345608

Kanai, Masatake; Nishimura, Mikio; Hayashi, Makoto

2010-06-01

22

Cucurbitane Triterpenoid from Momordica charantia Induces Apoptosis and Autophagy in Breast Cancer Cells, in Part, through Peroxisome Proliferator-Activated Receptor ? Activation  

PubMed Central

Although the antitumor activity of the crude extract of wild bitter gourd (Momordica charantia L.) has been reported, its bioactive constituents and the underlying mechanism remain undefined. Here, we report that 3?,7?-dihydroxy-25-methoxycucurbita-5,23-diene-19-al (DMC), a cucurbitane-type triterpene isolated from wild bitter gourd, induced apoptotic death in breast cancer cells through peroxisome proliferator-activated receptor (PPAR) ? activation. Luciferase reporter assays indicated the ability of DMC to activate PPAR?, and pharmacological inhibition of PPAR? protected cells from DMC's antiproliferative effect. Western blot analysis indicated that DMC suppressed the expression of many PPAR?-targeted signaling effectors, including cyclin D1, CDK6, Bcl-2, XIAP, cyclooxygenase-2, NF-?B, and estrogen receptor ?, and induced endoplasmic reticulum stress, as manifested by the induction of GADD153 and GRP78 expression. Moreover, DMC inhibited mTOR-p70S6K signaling through Akt downregulation and AMPK activation. The ability of DMC to activate AMPK in liver kinase (LK) B1-deficient MDA-MB-231 cells suggests that this activation was independent of LKB1-regulated cellular metabolic status. However, DMC induced a cytoprotective autophagy presumably through mTOR inhibition, which could be overcome by the cotreatment with the autophagy inhibitor chloroquine. Together, the ability of DMC to modulate multiple PPAR?-targeted signaling pathways provides a mechanistic basis to account for the antitumor activity of wild bitter gourd. PMID:23843889

Weng, Jing-Ru; Bai, Li-Yuan; Chiu, Chang-Fang; Hu, Jing-Lan; Chiu, Shih-Jiuan; Wu, Chia-Yung

2013-01-01

23

An oxidative and salinity stress induced peroxisomal ascorbate peroxidase from Avicennia marina: molecular and functional characterization.  

PubMed

APX (EC, 1.11.1.11) has a key role in scavenging ROS and in protecting cells against their toxic effects in algae and higher plants. A cDNA encoding a peroxisomal ascorbate peroxidase, Am-pAPX1, was isolated from salt stressed leaves of Avicennia marina (Forsk.) Vierh. by EST library screening and its expression in the context of various environmental stresses was investigated. Am-pAPX1 contains an ORF of 286 amino acids coding for a 31.4 kDa protein. The C-terminal region of the Am-pAPX1 ORF has a putative transmembrane domain and a peroxisomal targeting signal (RKKMK), suggesting peroxisomal localization. The peroxisomal localization of Am-pAPX1 was confirmed by stable transformation of the GFP-(Ala)(10)-Am-pAPX1 fusion in tobacco. RNA blot analysis revealed that Am-pAPX1 is expressed in response to salinity (NaCl) and oxidative stress (high intensity light, hydrogen peroxide application and excess iron). The isolated genomic clone of Am-pAPX1 was found to contain nine exons. A fragment of 1616bp corresponding to the 5' upstream region of Am-pAPX1 was isolated by TAIL-PCR. In silico analysis of this sequence reveals the presence of putative light and abiotic stress regulatory elements. PMID:18614374

Kavitha, Kumaresan; Venkataraman, Gayatri; Parida, Ajay

2008-01-01

24

Identification of a peroxisome proliferator responsive element (PPRE)-like cis-element in mouse plasminogen activator inhibitor-1 gene promoter  

SciTech Connect

PAI-1 is expressed and secreted by adipose tissue which may mediate the pathogenesis of obesity-associated cardiovascular complications. Evidence is presented in this report that PAI-1 is not expressed by preadipocyte, but significantly induced during 3T3-L1 adipocyte differentiation and the PAI-1 expression correlates with the induction of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}). A peroxisome proliferator responsive element (PPRE)-like cis-element (-206TCCCCCATGCCCT-194) is identified in the mouse PAI-1 gene promoter by electrophoretic mobility shift assay (EMSA) combined with transient transfection experiments; the PPRE-like cis-element forms a specific DNA-protein complex only with adipocyte nuclear extracts, not with preadipocyte nuclear extracts; the DNA-protein complex can be totally competed away by non-labeled consensus PPRE, and can be supershifted with PPAR{gamma} antibody. Mutation of this PPRE-like cis-element can abolish the transactivation of mouse PAI-1 promoter mediated by PPAR{gamma}. Specific PPAR{gamma} ligand Pioglitazone can significantly induce the PAI-1 expression, and stimulate the secretion of PAI-1 into medium.

Chen Jiegen [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Li Xi [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Huang Haiyan [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Liu Honglei [Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Liu Deguo [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Song Tanjing [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Ma Chungu [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Ma Duan [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Song Houyan [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China); Tang Qiqun [Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University Shanghai Medical School, Shanghai 200032 (China) and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical School, Shanghai 200032 (China) and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China)]. E-mail: qqtang@shmu.edu.cn

2006-09-01

25

An oxidative and salinity stress induced peroxisomal ascorbate peroxidase from Avicennia marina: Molecular and functional characterization  

Microsoft Academic Search

APX (EC, 1.11.1.11) has a key role in scavenging ROS and in protecting cells against their toxic effects in algae and higher plants. A cDNA encoding a peroxisomal ascorbate peroxidase, Am-pAPX1, was isolated from salt stressed leaves of Avicennia marina (Forsk.) Vierh. by EST library screening and its expression in the context of various environmental stresses was investigated. Am-pAPX1 contains

Kumaresan Kavitha; Gayatri Venkataraman; Ajay Parida

2008-01-01

26

Effects of peroxisome proliferator-activated receptor alpha (PPARalpha) agonists on leucine-induced phosphorylation of translational targets in C2C12 cells.  

PubMed

Effect of peroxisome proliferator-activated receptor alpha (PPARalpha) agonists, WY-14,643 (WY) and/or clofibrate, on the leucine-induced phosphorylation of translational targets in C2C12 myoblasts was studied. C2C12 cells were treated with WY or clofibrate for 24 h prior to stimulation with leucine. Western blot analyses revealed that the leucine-induced phosphorylation of p70 S6 kinase (p70S6K), a key regulator of translation initiation, was significantly higher in WY-treated cells than in control and clofibrate-treated cells. Phosphorylation of extracellular-regulated kinase (ERK1/2) was higher in WY-treated cells. WY treatment also increased the leucine-induced phosphorylation of ribosomal protein S6 and eukaryotic initiation factor 4B. In contrast, eukaryotic elongation factor 2, a marker for peptide chain elongation process, was significantly activated (dephosphorylated) only in leucine-stimulated control cells. Pre-treatment of the cells with PD98059 (ERK1/2 kinase inhibitor) prevented the phosphorylation of ERK1/2 and decreased the leucine-induced phosphorylation of p70S6K. It is concluded that WY increased the leucine-induced phosphorylation of target proteins involving in translation initiation via ERK/p70S6K pathway, but impaired the signaling for elongation process, suggesting that p70S6K phosphorylation may be essential, but not sufficient for the activation of entire targets for protein translation in WY-treated cells. PMID:18602970

Nakai, Naoya; Kawano, Fuminori; Terada, Masahiro; Oke, Yoshihiko; Ohira, Takashi; Ohira, Yoshinobu

2008-10-01

27

Thyroid hormone (T3) inhibits ciprofibrate-induced transcription of genes encoding beta-oxidation enzymes: cross talk between peroxisome proliferator and T3 signaling pathways.  

PubMed Central

Peroxisome proliferators cause rapid and coordinated transcriptional activation of genes encoding peroxisomal beta-oxidation system enzymes by activating peroxisome proliferator-activated receptor (PPAR) isoform(s). Since the thyroid hormone (T3; 3,3',5-triiodothyronine) receptor (TR), another member of the nuclear hormone receptor superfamily, regulates a subset of fatty acid metabolism genes shared with PPAR, we examined the possibility of interplay between peroxisome proliferator and T3 signaling pathways. T3 inhibited ciprofibrate-induced luciferase activity as well as the endogenous peroxisomal beta-oxidation enzymes in transgenic mice carrying a 3.2-kb 5'-flanking region of the rat peroxisomal enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase gene fused to the coding region of luciferase. Transfection assays in hepatoma H4-II-E-C3 and CV-1 cells indicated that this inhibition is mediated by TR in a ligand-dependent fashion. Gel shift assays revealed that modulation of PPAR action by TR occurs through titration of limiting amounts of retinoid X receptor (RXR) required for PPAR activation. Increasing amounts of RXR partially reversed the inhibition in a reciprocal manner; PPAR also inhibited TR activation. Results with heterodimerization-deficient TR and PPAR mutants further confirmed that interaction between PPAR and TR signaling systems is indirect. These results suggest that a convergence of the peroxisome proliferator and T3 signaling pathways occurs through their common interaction with the heterodimeric partner RXR. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:8524810

Chu, R; Madison, L D; Lin, Y; Kopp, P; Rao, M S; Jameson, J L; Reddy, J K

1995-01-01

28

Redox regulated peroxisome homeostasis  

PubMed Central

Peroxisomes are ubiquitous organelles present in nearly all eukaryotic cells. Conserved functions of peroxisomes encompass beta-oxidation of fatty acids and scavenging of reactive oxygen species generated from diverse peroxisomal metabolic pathways. Peroxisome content, number, and size can change quickly in response to environmental and/or developmental cues. To achieve efficient peroxisome homeostasis, peroxisome biogenesis and degradation must be orchestrated. We review the current knowledge on redox regulated peroxisome biogenesis and degradation with an emphasis on yeasts and plants. PMID:25545794

Wang, Xiaofeng; Li, Shuo; Liu, Yu; Ma, Changle

2014-01-01

29

Combination Therapy of an Intestine-Specific Inhibitor of Microsomal Triglyceride Transfer Protein and Peroxisome Proliferator-Activated Receptor ? Agonist in Diabetic Rat  

PubMed Central

We investigated effects on glucose and lipid metabolism in combination of JTT-130, a novel intestine-specific microsomal triglyceride transfer protein (MTP) inhibitor, and pioglitazone, peroxisome proliferator-activated receptor (PPAR) ? agonist. Male Zucker diabetic fatty rats were divided into 4 groups: control group, JTT-130 treatment group, pioglitazone treatment group, and combination group. The Zucker diabetic fatty rats were fed a regular powdered diet with JTT-130 and/or pioglitazone as a food admixture for 6 weeks. Effects on glucose and lipid metabolism were compared mainly between JTT-130 treatment group and combination group. JTT-130 treatment showed good glycemic control, while the plasma glucose and glycated hemoglobin levels in combination group were significantly decreased as compared with those JTT-130 treatment group. The reduction in the plasma triglyceride and free fatty acid levels in combination group was higher than that in JTT-130 treatment group, and glucose utilization was significantly elevated in adipose tissues. In Zucker diabetic fatty rats, combination treatment of JTT-130 and pioglitazone showed better glycemic control and a strong hypolipidemic action with an enhancement of insulin sensitivity. Combination therapy of MTP inhibitor and PPAR? agonist might be more useful in the treatment of type 2 diabetes accompanied with obesity and insulin resistance. PMID:24772450

Sakata, Shohei; Mera, Yasuko; Kuroki, Yukiharu; Nashida, Reiko; Kakutani, Makoto; Ohta, Takeshi

2014-01-01

30

Anti-kindling Effect of Bezafibrate, a Peroxisome Proliferator-activated Receptors Alpha Agonist, in Pentylenetetrazole Induced Kindling Seizure Model  

PubMed Central

Background and Purpose: Studies in the animals suggested that Peroxisome proliferators activated receptors (PPARs) may be involved in seizure control and selective agonists of PPAR ? or PPAR ? raise seizure thresholds. The present study was contemplated with the aim of evaluating the anti kindling effects and the mechanism of bezafibrate, a Peroxisome proliferator-activated receptors ? (PPAR-?) agonist in pentylenetetrazole (PTZ) induced kindling model of seizures in rats. Methods: In a PTZ kindled Wistar rat model, different doses of bezafibrate (100 mg/kg, 200 mg/kg and 300 mg/kg) were administered intraperitoneally 30 minutes before the PTZ injection. The PTZ injection was given on alternate day till the animal became fully kindled or till 10 weeks. The parameters measured were the latency to develop kindling and incidence of kindling, histopathological study of hippocampus, hippocampal lipid peroxidation studies, serum neuron specific enolase, and hippocampal DNA fragmentation study. Results: In this study, bezafibrate significantly reduced the incidence of kindling in PTZ treated rats and exhibited a marked prolongation in the latencies to seizures. In the present study bezafibrate decreased the thiobarbituric acid-reactive substance i.e. Malondialdehyde levels, increased the reduced glutathione levels, catalase and superoxide dismutase activity in the brain. This added to its additional neuroprotective effects. Bezafibrate also reduced the neuronal damage and apoptosis in hippocampal area of the brain. Therefore bezafibrate exerted anticonvulsant properties in PTZ induced kindling model in rats. Conclusions: These findings may provide insights into the understanding of the mechanism of bezafibrate as an anti kindling agent and could offer a useful support to the basic antiepileptic therapy in preventing the development of PTZ induced seizures, suggesting its potential for therapeutic applications in temporal lobe epilepsy. PMID:25625088

Saha, Lekha; Bhandari, Swati; Bhatia, Alka; Banerjee, Dibyajyoti; Chakrabarti, Amitava

2014-01-01

31

Peroxisome biogenesis in Saccharomyces cerevisiae  

Microsoft Academic Search

The observation that peroxisomes ofSaccharomyces cerevisiae can be induced by oleic acid has opened the possibility to investigate the biogenesis of these organelles in a biochemically and genetically well characterized organism. Only few enzymes have been identified as peroxisomal proteins inSaccharomyces cerevisiae so far; the three enzymes involved in ß-oxidation of fatty acids, enzymes of the glyoxylate cycle, catalase A

Wolf-H. Kunau; Andreas Hartig

1992-01-01

32

Molecular cloning and characterization of a mitochondrial peroxisome proliferator-induced acyl-CoA thioesterase from rat liver.  

PubMed Central

We have previously reported the purification and characterization of the peroxisome proliferator-induced very-long-chain acyl-CoA thioesterase (MTE-I) from rat liver mitochondria [L.T. Svensson, S.E. H. Alexson and J.K. Hiltunen (1995) J. Biol. Chem. 270, 12177-12183]. Here we describe the cloning of the corresponding cDNA. One full-length clone was isolated that contained an open reading frame of 1359 bp encoding a polypeptide with a calculated molecular mass of 49707 Da. The deduced amino acid sequence contains a putative mitochondrial leader peptide of 42 residues. Expression of the cDNA in Chinese hamster ovary cells, followed by immunofluorescence, immunoelectron microscopy and Western blot analyses, showed that the product was targeted to mitochondria and processed to a mature protein of 45 kDa, which is similar to the molecular mass of the protein isolated from rat liver mitochondria. The recombinant enzyme showed the same acyl-CoA chain-length specificity as the isolated rat liver enzyme. Sequence analysis showed no similarity to known esterases, but a high degree (approx. 40%) of identity with bile acid-CoA:amino acid N-acyltransferase cloned from human and rat liver. A putative active-site serine motif (Gly-Xaa-Ser-Xaa-Gly) of several carboxylesterases and lipases was identified. Western and Northern blot analyses showed that MTE-I is constitutively expressed in heart and is strongly induced in liver by feeding rats with di(2-ethylhexyl)phthalate, a peroxisome proliferator, suggesting a role for the enzyme in lipid metabolism. PMID:9445388

Svensson, L T; Engberg, S T; Aoyama, T; Usuda, N; Alexson, S E; Hashimoto, T

1998-01-01

33

Impacts of peroxisome proliferator-activated receptor-? activation on cigarette smoke-induced exacerbated response to bacteria.  

PubMed

Chronic obstructive pulmonary disease (COPD) is characterised by a state of chronic pulmonary inflammation punctuated by microbial exacerbations. Despite advances in treatment options, COPD remains difficult to manage. In this study, we investigated the potential of peroxisome proliferator-activated receptor (PPAR)? activation as a new therapy against cigarette smoke-induced inflammation and its associated bacterial exacerbation. C57BL/6 mice were exposed to room air or cigarette smoke for either 4 days or 4 weeks and treated either prophylactically or therapeutically with rosiglitazone. The impact of rosiglitazone on cigarette smoke-induced exacerbated response to the bacterial pathogen nontypeable Haemophilus influenzae (NTHi) was studied using the therapeutic treatment protocol. We found that rosiglitazone was able to reduce cigarette smoke-induced neutrophilia both when administered prophylactically or therapeutically. Therapeutic intervention with rosiglitazone was also effective in preventing cigarette smoke-induced neutrophilia exacerbation following NTHi infection. Moreover, the anti-inflammatory effects of rosiglitazone did not lead to an increase in the pulmonary bacterial burden, unlike dexamethasone. Altogether, our data suggest that pharmacological activation of PPAR? may be an effective therapeutic approach to improve COPD management, as it is able to reduce cigarette smoke-induced inflammation and decrease the magnitude of bacterial exacerbations, without compromising the ability of the immune system to control the infection. PMID:25034559

Morissette, Mathieu C; Shen, Pamela; Thayaparan, Danya; Stämpfli, Martin R

2015-01-01

34

Protective role of peroxisome proliferator-activated receptor ?/? in acute lung injury induced by prolonged hyperbaric hyperoxia in rats.  

PubMed

Peroxisome proliferator-activated receptor (PPAR)-?/? is a transcription factor that belongs to the PPAR family, but the role of PPAR-?/? in acute lung injury (ALI) induced by hyperbaric oxygen is unknown. In this study we investigated if PPAR-?/? activation protects from hyperoxia-induced ALI in a rat model. ALI was induced by prolonged hyperbaric oxygen (HBO2) (2.3ATA, 100% O2) for 8h. Administration of PPAR-?/? agonist GW0742 (0.3mg/kg, i.p.) at 1 and 6h prior to HBO2 exposure significantly reduced the (1) lung injury, (2) proinflammatory cytokines (TNF-?, IL-1?, IL-6), (3) apoptosis (Bax/Bcl-2, cleaved-caspase-3 and TUNEL), (4) nuclear factor (NF)-?B expression level and DNA binding activity in the nucleus, and (5) extracellular signal-regulated kinase (ERK)1/2 phosphorylation and markedly elevated (6) superoxide dismutase and glutathione peroxidase activities as well as (7) I?B expression. However, administration of the PPAR-?/? antagonist GSK0660 abolished these protective effects. These findings indicate that activation of PPAR-?/? ameliorates hyperoxia-induced ALI in rats by up-regulating antioxidant enzyme activity as well as suppressing inflammation and apoptosis. PMID:24780550

Bao, Xiao-Chen; Fang, Yi-Qun; You, Pu; Zhang, Shi; Ma, Jun

2014-08-01

35

Hepatic sirtuin 1 is dispensable for fibrate-induced peroxisome proliferator-activated receptor-? function in vivo.  

PubMed

Peroxisome proliferator-activated receptor-? (PPAR?) mediates metabolic remodeling, resulting in enhanced mitochondrial and peroxisomal ?-oxidation of fatty acids. In addition to the physiological stimuli of fasting and high-fat diet, PPAR? is activated by the fibrate class of drugs for the treatment of dyslipidemia. Sirtuin 1 (SIRT1), an important regulator of energy homeostasis, was downregulated in fibrate-treated wild-type mice, suggesting PPAR? regulation of Sirt1 gene expression. The impact of SIRT1 loss on PPAR? functionality in vivo was assessed in hepatocyte-specific knockout mice that lack the deacetylase domain of SIRT1 (Sirt1(?Liv)). Knockout mice were treated with fibrates or fasted for 24 h to activate PPAR?. Basal expression of the PPAR? target genes Cyp4a10 and Cyp4a14 was reduced in Sirt1(?Liv) mice compared with wild-type mice. However, no difference was observed between wild-type and Sirt1(?Liv) mice in either fasting- or fibrate-mediated induction of PPAR? target genes. Similar to the initial results, there was no difference in fibrate-activated PPAR? gene induction. To assess the relationship between SIRT1 and PPAR? in a pathophysiological setting, Sirt1(?Liv) mice were maintained on a high-fat diet for 14 wk, followed by fibrate treatment. Sirt1(?Liv) mice exhibited increased body mass compared with control mice. In the context of a high-fat diet, Sirt1(?Liv) mice did not respond to the cholesterol-lowering effects of the fibrate treatment. However, there were no significant differences in PPAR? target gene expression. These results suggest that, in vivo, SIRT1 deacetylase activity does not significantly impact induced PPAR? activity. PMID:24496310

Bonzo, Jessica A; Brocker, Chad; Jiang, Changtao; Wang, Rui-Hong; Deng, Chu-Xia; Gonzalez, Frank J

2014-04-01

36

Dietary conjugated linoleic acid induces peroxisome-specific enzyme accumulation and ornithine decarboxylase activity in mouse liver  

Microsoft Academic Search

Previous studies have shown that the dietary fatty acids, conjugated linoleic acids (CLA), inhibit carcinogenesis in the colon, mammary gland, forestomach, and skin. Several properties of this chemoprotective polyunsaturated fatty acid suggest it will act as an hepatic peroxisome proliferator. This study evaluated the effect of dietary CLA on the accumulation of enzymes associated with peroxisome proliferation in rodent liver.

Martha A. Belury; Silvia Y. Moya-Camarena; Kai-Li Liu; John P. Vanden Heuvel

1997-01-01

37

Peroxisome Proliferator Activator Receptor (PPAR)- ? Ligand, but Not PPAR- ? , Ameliorates Cyclophosphamide-Induced Oxidative Stress and Inflammation in Rat Liver.  

PubMed

Hepatoprotective potential of peroxisome proliferator activator receptor (PPAR)- ? and - ? agonists, fenofibrate (FEN), and pioglitazone (PIO), respectively, against cyclophosphamide (CP)-induced toxicity has been investigated in rat. FEN and PIO (150 and 10?mg/kg/day, resp.) were given orally for 4 weeks. In separate groups, CP (150?mg/kg, i.p.) was injected as a single dose 5 days before the end of experiment, with or without either PPAR agonist. CP induced hepatotoxicity, as it caused histopathological alterations, with increased serum alanine and aspartate transaminases, total bilirubin, albumin, alkaline phosphatase and lactate dehydrogenase. CP caused hepatic oxidative stress, indicated by decrease in tissue reduced glutathione, with increase in malondialdehyde and nitric oxide levels. CP also caused decrease in hepatic antioxidant enzyme levels, including catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase. Furthermore, CP increased serum and hepatic levels of the inflammatory marker tumor necrosis factor (TNF)- ? , evaluated using ELISA. Preadministration of PIO, but not FEN, prior to CP challenge improved hepatic function and histology, and significantly reversed oxidative and inflammatory parameters. In conclusion, activation of PPAR- ? , but not PPAR- ? , conferred protection against CP-induced hepatotoxicity, via activation of antioxidant and anti-inflammatory mechanisms, and may serve as supplement during CP chemotherapy. PMID:24803924

El-Sheikh, Azza A K; Rifaai, Rehab A

2014-01-01

38

Peroxisome Proliferator Activator Receptor (PPAR)-? Ligand, but Not PPAR-?, Ameliorates Cyclophosphamide-Induced Oxidative Stress and Inflammation in Rat Liver  

PubMed Central

Hepatoprotective potential of peroxisome proliferator activator receptor (PPAR)-? and -? agonists, fenofibrate (FEN), and pioglitazone (PIO), respectively, against cyclophosphamide (CP)-induced toxicity has been investigated in rat. FEN and PIO (150 and 10?mg/kg/day, resp.) were given orally for 4 weeks. In separate groups, CP (150?mg/kg, i.p.) was injected as a single dose 5 days before the end of experiment, with or without either PPAR agonist. CP induced hepatotoxicity, as it caused histopathological alterations, with increased serum alanine and aspartate transaminases, total bilirubin, albumin, alkaline phosphatase and lactate dehydrogenase. CP caused hepatic oxidative stress, indicated by decrease in tissue reduced glutathione, with increase in malondialdehyde and nitric oxide levels. CP also caused decrease in hepatic antioxidant enzyme levels, including catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase. Furthermore, CP increased serum and hepatic levels of the inflammatory marker tumor necrosis factor (TNF)-?, evaluated using ELISA. Preadministration of PIO, but not FEN, prior to CP challenge improved hepatic function and histology, and significantly reversed oxidative and inflammatory parameters. In conclusion, activation of PPAR-?, but not PPAR-?, conferred protection against CP-induced hepatotoxicity, via activation of antioxidant and anti-inflammatory mechanisms, and may serve as supplement during CP chemotherapy. PMID:24803924

El-Sheikh, Azza A. K.; Rifaai, Rehab A.

2014-01-01

39

Identification and functional reconstitution of the yeast peroxisomal adenine nucleotide transporter  

PubMed Central

The requirement for small molecule transport systems across the peroxisomal membrane has previously been postulated, but not directly proven. Here we report the identification and functional reconstitution of Ant1p (Ypr128cp), a peroxisomal transporter in the yeast Saccharomyces cerevisiae, which has the characteristic sequence features of the mitochondrial carrier family. Ant1p was found to be an integral protein of the peroxisomal membrane and expression of ANT1 was oleic acid inducible. Targeting of Ant1p to peroxisomes was dependent on Pex3p and Pex19p, two peroxins specifically required for peroxisomal membrane protein insertion. Ant1p was essential for growth on medium-chain fatty acids as the sole carbon source. Upon reconstitution of the overexpressed and purified protein into liposomes, specific transport of adenine nucleotides could be demonstrated. Remarkably, both the substrate and inhibitor specificity differed from those of the mitochondrial ADP/ATP transporter. The physiological role of Ant1p in S.cerevisiae is probably to transport cytoplasmic ATP into the peroxisomal lumen in exchange for AMP generated in the activation of fatty acids. PMID:11566870

Palmieri, Luigi; Rottensteiner, Hanspeter; Girzalsky, Wolfgang; Scarcia, Pasquale; Palmieri, Ferdinando; Erdmann, Ralf

2001-01-01

40

The Peroxisomal Proliferator-Activated Receptor (PPAR) ? Agonist, Fenofibrate, Prevents Fractionated Whole-Brain Irradiation-Induced Cognitive Impairment  

PubMed Central

We hypothesized that dietary administration of the peroxisomal proliferator-activated receptor ? agonist, fenofibrate, to young adult male rats would prevent the fractionated whole-brain irradiation (fWBI)-induced reduction in cognitive function and neurogenesis and prevent the fWBI-induced increase in the total number of activated microglia. Eighty 12–14-week-old young adult male Fischer 344 × Brown Norway rats received either: (1) sham irradiation, (2) 40 Gy of fWBI delivered as two 5 Gy fractions/week for 4 weeks, (3) sham irradiation + dietary fenofibrate (0.2% w/w) starting 7 days prior to irradiation, or (4) fWBI + fenofibrate. Cognitive function was measured 26–29 weeks after irradiation using: (1) the perirhinal cortex (PRh)-dependent novel object recognition task; (2) the hippocampal-dependent standard Morris water maze (MWM) task; (3) the hippocampal-dependent delayed match-to-place version of the MWM task; and (4) a cue strategy preference version of the MWM to distinguish hippocampal from striatal task performance. Neurogenesis was assessed 29 weeks after fWBI in the granular cell layer and subgranular zone of the dentate gyrus using a doublecortin antibody. Microglial activation was assessed using an ED1 antibody in the dentate gyrus and hilus of the hippocampus. A significant impairment in perirhinal cortex-dependent cognitive function was measured after fWBI. In contrast, fWBI failed to alter hippocampal-dependent cognitive function, despite a significant reduction in hippocampal neurogenesis. Continuous administration of fenofibrate prevented the fWBI-induced reduction in perirhinal cortex-dependent cognitive function, but did not prevent the radiation-induced reduction in neurogenesis or the radiation-induced increase in activated microglia. These data suggest that fenofibrate may be a promising therapeutic for the prevention of some modalities of radiation-induced cognitive impairment in brain cancer patients. PMID:24397438

Greene-Schloesser, Dana; Payne, Valerie; Peiffer, Ann M.; Hsu, Fang-Chi; Riddle, David R.; Zhao, Weiling; Chan, Michael D.; Metheny-Barlow, Linda; Robbins, Mike E.

2014-01-01

41

Pioglitazone, a specific ligand of peroxisome proliferator-activated receptor-gamma, protects pancreas against acute cerulein-induced pancreatitis  

PubMed Central

AIM: To determine the effect of pioglitazone, a specific peroxisome proliferator-activated receptor-? (PPAR?) ligand, on the development of acute pancreatitis (AP) and on the expression of heat shock protein 70 (HSP70) in the pancreas. METHODS: AP was induced in rats by subcutaneous infusion of cerulein for 5 h. Pancreatic blood flow was measured by laser Doppler flowmetry. Plasma lipase activity, interleukin-1? (IL-1?) and IL-10 were determined. Pancreatic weight and histology were evaluated and pancreatic DNA synthesis and blood flow as well as pancreatic mRNA for IL-1? and HSP70 were assessed in rats treated with pioglitazone alone or in combination with cerulein. RESULTS: Pioglitazone administered (10-100 mg/kg i.g.) 30 min before cerulein, attenuated dose-dependently the pancreatic tissue damage in cerulein-induced pancreatitis (CIP) as demonstrated by the improvement of pancreatic histology, reduction in plasma lipase activity, plasma concentration of pro-inflammatory IL-1? and its gene expression in the pancreas and attenuation of the pancreatitis-evoked fall in pancreatic blood flow. CIP increased pancreatic HSP70 mRNA and protein expression in the pancreas and this effect was enhanced by pioglitazone treatment. CONCLUSION: Pioglitazone attenuates CIP and the beneficial effect of this pioglitazone is multifactorial probably due to its anti-inflammatory activities, to the suppression of IL-1? and to the overexpression of HSP70. PPAR? ligands could represent a new therapeutic option in the treatment of AP. PMID:16419161

Konturek, Peter C; Dembinski, Artur; Warzecha, Zygmunt; Burnat, Grzegorz; Ceranowicz, Piotr; Hahn, Eckhart G; Dembinski, Marcin; Tomaszewska, Romana; Konturek, Stanislaw J

2005-01-01

42

Moderate Iron Overload Enhances Lipid Peroxidation in Livers of Rats, but Does Not Affect NF-B Activation Induced by the Peroxisome Proliferator, Wy14,6431,2  

Microsoft Academic Search

It has been hypothesized that high concentrations of tissue iron may enhance carcinogenesis induced by free radical mechanisms. Wy-14,643 is a peroxisome proliferator that is hepatocarcinogenic in rats. Tumor induction may result in part from excessive production of reactive oxygen species, particularly H2O2. The purpose of this study was to examine the effect of iron status on oxidative stress and

Joan G. Fischer; Howard P. Glauert; Taofei Yin; Mary L. Sweeney-Reeves; Nicolas Larmonier; Marsha C. Black

43

Epoxide hydrolase in human and rat peroxisomes: implication for disorders of peroxisomal biogenesis.  

PubMed

To understand the basis of excretion of excessive amounts of epoxydicarboxylic fatty acids (EDFA) in urine of patients with disorders of peroxisomal biogenesis (Pitt, J. J., and A. Poulos. 1993. Clin. Chim. Acta. 223: 23-29), the activity of epoxide hydrolase (EH) was measured in cultured skin fibroblasts from control subjects and patients with peroxisomal disorders. EH activity was approximately 40% lower in fibroblasts that lack intact peroxisomes (Zellweger syndrome), whereas the activity in other peroxisomal disorders (X-adrenoleukodystrophy and rhizomelic chondrodysplasia punctata) with intact peroxisomes was similar to control. To identify the specific enzyme/organelle that represents the decrease in EH activity in Zellweger cells, we have analyzed this activity in different subcellular organelles from control and Zellweger skin fibroblasts. EH activity was enriched in peroxisomes from control fibroblast. EH activity in isolated mitochondria, microsomes, or cytosol from Zellweger fibroblast was similar to that of control fibroblast. These observations indicate that deficient activity of EH in cells from Zellweger patients is due to lack of peroxisomal EH activity. The peroxisomal EH is differentially induced to a higher degree by ciprofibrate, a hypolipidemic agent and peroxisome proliferator, than EH activity in other organelles and cytoplasm. The high specific activity of EH in peroxisomes and differential induction of EH activity in peroxisomes as compared to other organelles, and the excretion of EDFA in patients who lack peroxisomes suggests that peroxisomal EH may be responsible for the detoxification of EDFA, and that this enzyme in peroxisomes may be a different protein than the EH found in other organelles. PMID:8820111

Pahan, K; Smith, B T; Singh, I

1996-01-01

44

Proteinase Inhibitor-inducing Factor in Plant Leaves  

PubMed Central

Thirty-nine plant species representing 20 families from the four major divisions of plants were surveyed for the presence of proteinase inhibitor-inducing factor activity in leaves or other tissues. Tissue juices were assayed for their capacity to induce accumulation of proteinase inhibitor I in excised tomato (Lycopersico esculentum) leaves. In tissues of only 2 of the 39 species was proteinase inhibitor-inducing factor-like activity not found. The activity was absent in cabbage leaves and celery stalks. Fruiting bodies from one of three fungi genera assayed contained exceptionally large quantities of proteinase inhibitor-inducing factor-like activity. Extracts from Agraricus campestris fruiting bodies contained over 20 times more activity than tomato leaf juice. The survey confirms that substances with proteinase inhibitor-inducing factor-like activity are widespread in the plant kingdom. PMID:16658956

McFarland, Douglas; Ryan, Clarence A.

1974-01-01

45

Obese Mice Lacking Inducible Nitric Oxide Synthase Are Sensitized to the Metabolic Actions of Peroxisome Proliferator–Activated Receptor-? Agonism  

PubMed Central

OBJECTIVE—Synthetic ligands for peroxisome proliferator–activated receptor-? (PPAR-?) improve insulin sensitivity in obesity, but it is still unclear whether inflammatory signals modulate their metabolic actions. In this study, we tested whether targeted disruption of inducible nitric oxide (NO) synthase (iNOS), a key inflammatory mediator in obesity, modulates the metabolic effects of rosiglitazone in obese mice. RESEARCH DESIGN AND METHODS—iNOS?/? and iNOS+/+ were subjected to a high-fat diet or standard diet for 18 weeks and were then treated with rosiglitazone for 2 weeks. Whole-body insulin sensitivity and glucose tolerance were determined and metabolic tissues harvested to assess activation of insulin and AMP-activated protein kinase (AMPK) signaling pathways and the levels of inflammatory mediators. RESULTS—Rosiglitazone was found to similarly improve whole-body insulin sensitivity and insulin signaling to Akt/PKB in skeletal muscle of obese iNOS?/? and obese iNOS+/+ mice. However, rosiglitazone further improved glucose tolerance and liver insulin signaling only in obese mice lacking iNOS. This genotype-specific effect of rosiglitazone on glucose tolerance was linked to a markedly increased ability of the drug to raise plasma adiponectin levels. Accordingly, rosiglitazone increased AMPK activation in muscle and liver only in obese iNOS?/? mice. PPAR-? transcriptional activity was increased in adipose tissue of iNOS?/? mice. Conversely, treatment of 3T3-L1 adipocytes with a NO donor blunted PPAR-? activity. CONCLUSIONS—Our results identify the iNOS/NO pathway as a critical modulator of PPAR-? activation and circulating adiponectin levels and show that invalidation of this key inflammatory mediator improves the efficacy of PPAR-? agonism in an animal model of obesity and insulin resistance. PMID:18458147

Dallaire, Patrice; Bellmann, Kerstin; Laplante, Mathieu; Gélinas, Stéphanie; Centeno-Baez, Carolina; Penfornis, Patrice; Peyot, Marie-Line; Latour, Martin G.; Lamontagne, Julien; Trujillo, Maria E.; Scherer, Philipp E.; Prentki, Marc; Deshaies, Yves; Marette, André

2008-01-01

46

Peroxisome Proliferator-Activated Receptor-/ Protects Against Chemically Induced Liver Toxicity in Mice  

E-print Network

carbon tetrachlo- ride (CCl4) hepatoxicity was also observed in PPAR / -null as compared with wild activation of AOM and CCl4 were observed between wild-type or PPAR / - null mice in response to CCl4 against liver toxicity induced by AOM and CCl4, suggesting that this receptor is hepatoprotective against

Omiecinski, Curtis

47

Supplemental Material -Bisphenol A Diglycidyl Ether Induces Adipogenic Differentiation of Multipotent Stromal Stem Cells through a Peroxisome Proliferator Activated Receptor  

E-print Network

of Multipotent Stromal Stem Cells through a Peroxisome Proliferator Activated Receptor Gamma1 , Connie Chow1 , and Bruce Blumberg1, 2 1 Department of Developmental and Cell Biology, 2011 to -Actin. A gene was considered not expressed in the cell preparation if its mean Ct value exceeded 38

Blumberg, Bruce

48

Phosphoinositide synthesis and degradation in isolated rat liver peroxisomes.  

PubMed

Analyzing peroxisomal phosphoinositide (PId(#)) synthesis in highly purified rat liver peroxisomes we found synthesis of phosphatidylinositol 4-phosphate (PtdIns4P), PtdIns(4,5)P(2) and PtdIns(3,5)P(2). PtdIns3P was hardly detected in vitro, however, was observed in vivo after [(32)P]-phosphate labeling of primary rat hepatocytes. In comparison with other subcellular organelles peroxisomes revealed a unique PId pattern suggesting peroxisomal specificity of the observed synthesis. Use of phosphatase inhibitors enhanced the amount of PtdIns4P. The results obtained provide evidence that isolated rat liver peroxisomes synthesize PIds and suggest the association of PId 4-kinase and PId 5-kinase and PId 4-phosphatase activities with the peroxisomal membrane. PMID:17045591

Jeynov, Boyan; Lay, Dorothee; Schmidt, Frank; Tahirovic, Sabina; Just, Wilhelm W

2006-10-30

49

Proteolytic cleavage of plant proteins by peroxisomal endoproteases from senescent pea leaves  

Microsoft Academic Search

.   The degradation of peroxisomal and nonperoxisomal proteins by endoproteases of purified peroxisomes from senescent pea (Pisum sativum L.) leaves has been investigated. In our experimental conditions, most peroxisomal proteins were endoproteolytically degraded.\\u000a This cleavage was prevented, to some extent, by incubation with 2?mM phenylmethylsulfonylfluoride, an inhibitor of serine\\u000a proteinases. The peroxisomal enzymes glycolate oxidase (EC 1.1.3.1), catalase (EC 1.11.1.6)

Stefania Distefano; José M. Palma; Iva McCarthy; Luis A. del Río

1999-01-01

50

Peroxisome proliferator-induced acyl-CoA thioesterase from rat liver cytosol: molecular cloning and functional expression in Chinese hamster ovary cells.  

PubMed Central

We have isolated and cloned a cDNA that codes for one of the peroxisome proliferator-induced acyl-CoA thioesterases of rat liver. The deduced amino acid sequence corresponds to the major induced isoform in cytosol. Analysis and comparison of the deduced amino acid sequence with the established consensus sequences suggested that this enzyme represents a novel kind of esterase with an incomplete lipase serine active site motif. Analyses of mRNA and its expression indicated that the enzyme is significantly expressed in liver only after peroxisome proliferator treatment, but isoenzymes are constitutively expressed at high levels in testis and brain. The reported cDNA sequence is highly homologous to the recently cloned brain acyl-CoA thioesterase [Broustas, Larkins, Uhler and Hajra (1996) J. Biol. Chem. 271, 10470-10476], but subtle differences throughout the sequence, and distinct differences close to the resulting C-termini, suggest that they are different enzymes, regulated in different manners. A full-length cDNA clone was expressed in Chinese hamster ovary cells and the expressed enzyme was characterized. The palmitoyl-CoA hydrolysing activity (Vmax) was induced approx. 9-fold to 1 micromol/min per mg of cell protein, which was estimated to correspond to a specific activity of 250 micromol/min per mg of cDNA-expressed enzyme. Both the specific activity and the acyl-CoA chain length specificity were very similar to those of the purified rat liver enzyme. PMID:9163348

Engberg, S T; Aoyama, T; Alexson, S E; Hashimoto, T; Svensson, L T

1997-01-01

51

ABCD2 alters peroxisome proliferator-activated receptor ? signaling in vitro, but does not impair responses to fenofibrate therapy in a mouse model of diet-induced obesity.  

PubMed

Fenofibrate is a peroxisome proliferator-activated receptor (PPAR) ? ligand that has been widely used as a lipid-lowering agent in the treatment of hypertriglyceridemia. ABCD2 (D2) is a peroxisomal long-chain acyl-CoA transporter that is highly induced by fenofibrate in the livers of mice. To determine whether D2 is a modifier of fibrate responses, wild-type and D2-deficient mice were treated with fenofibrate for 14 days. The absence of D2 altered expression of gene clusters associated with lipid metabolism, including PPAR? signaling. Using 3T3-L1 adipocytes, which express high levels of D2, we confirmed that knockdown of D2 modified genomic responses to fibrate treatment. We next evaluated the impact of D2 on effects of fibrates in a mouse model of diet-induced obesity. Fenofibrate treatment opposed the development of obesity, hypertriglyceridemia, and insulin resistance. However, these effects were unaffected by D2 genotype. We concluded that D2 can modulate genomic responses to fibrates, but that these effects are not sufficiently robust to alter the effects of fibrates on diet-induced obesity phenotypes. PMID:25123288

Liu, Xiaoxi; Liu, Jingjing; Liang, Shuang; Schlüter, Agatha; Fourcade, Stephane; Aslibekyan, Stella; Pujol, Aurora; Graf, Gregory A

2014-11-01

52

Hsp90 inhibitor induces autophagy and apoptosis in osteosarcoma cells  

PubMed Central

Heat shock protein 90 (Hsp90) is constitutively expressed at 2-10-fold higher levels in tumor cells compared to normal cells, suggesting that it may be critically important for tumor cell growth and survival. These features make Hsp90 a potential target for anticancer drug development. Inhibition of Hsp90 activity not only results in rapid degradation of Hsp90 client proteins but also induces apoptosis of various tumor cells. Hsp90 also plays an important role in autophagy. An Hsp90 inhibitor induces autophagy through inhibition of mTOR. It is still under debate whether chemotherapy-induced autophagy in tumor cells is a protective response or is invoked to promote cell death. The aim of this study was to examine the effects of the Hsp90 inhibitor, geldanamycin (GA), on KTHOS osteosarcoma cells. We further examined whether a combination of GA and the autophagy inhibitor 3-methyl-adenine (3-MA) enhanced GA-induced apoptosis in KTHOS cells. GA had an inhibitory effect on cell proliferation and inhibited the Akt/mTOR signaling pathway in KTHOS cells. GA alone induced autophagy and apoptosis in KTHOS cells, but treatment with a combination of GA and 3-MA suppressed autophagy and induced apoptosis to a much greater extent than GA alone in these cells. It was considered that the autophagy inhibitor 3-MA suppressed a protective mechanism induced by Hsp90 inhibitor in tumor cells and induced apoptosis. Therefore, the combination of an Hsp90 inhibitor and an autophagy inhibitor may be an effective treatment for osteosarcoma because this combination effectively induces apoptotic pathways. PMID:25351442

MORI, MASAKI; HITORA, TOSHIAKI; NAKAMURA, OSAMU; YAMAGAMI, YOSHIKI; HORIE, RYOSUKE; NISHIMURA, HIDEKI; YAMAMOTO, TETSUJI

2015-01-01

53

Peroxisome Biogenesis and Function  

PubMed Central

Peroxisomes are small and single membrane-delimited organelles that execute numerous metabolic reactions and have pivotal roles in plant growth and development. In recent years, forward and reverse genetic studies along with biochemical and cell biological analyses in Arabidopsis have enabled researchers to identify many peroxisome proteins and elucidate their functions. This review focuses on the advances in our understanding of peroxisome biogenesis and metabolism, and further explores the contribution of large-scale analysis, such as in sillco predictions and proteomics, in augmenting our knowledge of peroxisome function In Arabidopsis. PMID:22303249

Kaur, Navneet; Reumann, Sigrun; Hu, Jianping

2009-01-01

54

Peroxisomal APX knockdown triggers antioxidant mechanisms favourable for coping with high photorespiratory H2 O2 induced by CAT deficiency in rice.  

PubMed

The physiological role of peroxisomal ascorbate peroxidases (pAPX) is unknown; therefore, we utilized pAPX4 knockdown rice and catalase (CAT) inhibition to assess its role in CAT compensation under high photorespiration. pAPX4 knockdown induced co-suppression in the expression of pAPX3. The rice mutants exhibited metabolic changes such as lower CAT and glycolate oxidase (GO) activities and reduced glyoxylate content; however, APX activity was not altered. CAT inhibition triggered different changes in the expression of CAT, APX and glutathione peroxidase (GPX) isoforms between non-transformed (NT) and silenced plants. These responses were associated with alterations in APX, GPX and GO activities, suggesting redox homeostasis differences. The glutathione oxidation-reduction states were modulated differently in mutants, and the ascorbate redox state was greatly affected in both genotypes. The pAPX suffered less oxidative stress and photosystem II (PSII) damage and displayed higher photosynthesis than the NT plants. The improved acclimation exhibited by the pAPX plants was indicated by lower H2 O2 accumulation, which was associated with lower GO activity and glyoxylate content. The suppression of both pAPXs and/or its downstream metabolic and molecular effects may trigger favourable antioxidant and compensatory mechanisms to cope with CAT deficiency. This physiological acclimation may involve signalling by peroxisomal H2 O2 , which minimized the photorespiration. PMID:25039271

Sousa, Rachel H V; Carvalho, Fabricio E L; Ribeiro, Carol W; Passaia, Gisele; Cunha, Juliana R; Lima-Melo, Yugo; Margis-Pinheiro, Márcia; Silveira, Joaquim A G

2015-03-01

55

Wogonin prevents lipopolysaccharide-induced acute lung injury and inflammation in mice via peroxisome proliferator-activated receptor gamma-mediated attenuation of the nuclear factor-kappaB pathway.  

PubMed

Acute lung injury (ALI) from a variety of clinical disorders, characterized by diffuse inflammation, is a cause of acute respiratory failure that develops in patients of all ages. Previous studies reported that wogonin, a flavonoid-like chemical compound which was found in Scutellaria baicalensis, has anti-inflammatory effects in several inflammation models, but not in ALI. Here, the in vivo protective effect of wogonin in the amelioration of lipopolysaccharide (LPS) -induced lung injury and inflammation was assessed. In addition, the in vitro effects and mechanisms of wogonin were studied in the mouse macrophage cell lines Ana-1 and RAW264.7. In vivo results indicated that wogonin attenuated LPS-induced histological alterations. Peripheral blood leucocytes decreased in the LPS-induced group, which was ameliorated by wogonin. In addition, wogonin inhibited the production of several inflammatory cytokines, including tumour necrosis factor-?, interleukin-1? (IL-1?) and IL-6, in the bronchoalveolar lavage fluid and lung tissues after LPS challenge, while the peroxisome proliferator-activated receptor ? (PPAR?) inhibitor GW9662 reversed these effects. In vitro results indicated that wogonin significantly decreased the secretion of IL-6, IL-1? and tumour necrosis factor-? in Ana-1 and RAW264.7 cells, which was suppressed by transfection of PPAR? small interfering RNA and GW9662 treatment. Moreover, wogonin activated PPAR?, induced PPAR?-mediated attenuation of the nuclear translocation and the DNA-binding activity of nuclear factor-?B in vivo and in vitro. In conclusion, all of these results showed that wogonin may serve as a promising agent for the attenuation of ALI-associated inflammation and pathology by regulating the PPAR?-involved nuclear factor-?B pathway. PMID:24766487

Yao, Jing; Pan, Di; Zhao, Yue; Zhao, Li; Sun, Jie; Wang, Yu; You, Qi-Dong; Xi, Tao; Guo, Qing-Long; Lu, Na

2014-10-01

56

12/15-Lipoxygenase inhibitor baicalein suppresses PPAR gamma expression and nuclear translocation induced by cerebral ischemia/reperfusion.  

PubMed

Accumulating evidences have demonstrated the beneficial actions of peroxisome proliferator-activated receptor gamma (PPAR gamma) in a variety of animal stroke models. Following middle cerebral artery occlusion (60 min) and 2-24 hr reperfusion in rats, we observed cerebral ischemia/reperfusion (I/R) induced up-regulation of PPAR gamma protein expression and translocation from the cytoplasm into the nucleus in a time-dependent manner. We also found that PPAR gamma agonist rosiglitazone enhanced whereas PPAR gamma antagonist GW9662 inhibited the alteration of PPAR gamma stimulated by I/R, suggesting that the changes of PPAR gamma may result from the activation by endogenous ligands. Moreover, the link between the 12/15-lipoxygenase and the production of activating ligands for PPAR gamma has been proved in various tissues. However, the relation of them in brain tissue has not been identified. We demonstrated that the I/R-induced PPAR gamma alteration was reversed by baicalein, the specific inhibitor of 12/15-lipoxygenase. Baicalein treatment significantly inhibited the up-regulation of PPAR gamma expression and, furthermore, suppressed PPAR gamma nuclear accumulation as well as maintained PPAR gamma cytoplasmic retention. Together, these results suggest that I/R induces both PPAR gamma expression and translocation, probably through the activation by endogenous ligands in a 12/15-lipoxygenase inhibitor-sensitive way. PMID:19853588

Xu, Yan-Wei; Sun, Li; Liang, Hao; Sun, Guo-Min; Cheng, Yan

2010-01-11

57

Partial disassembly of peroxisomes  

PubMed Central

Rat liver peroxisomes were subjected to a variety of procedures intended to partially disassemble or damage them; the effects were analyzed by recentrifugation into sucrose gradients, enzyme analyses, electron microscopy, and SDS PAGE. Freezing and thawing or mild sonication released some matrix proteins and produced apparently intact peroxisomal "ghosts" with crystalloid cores and some fuzzy fibrillar content. Vigorous sonication broke open the peroxisomes but the membranes remained associated with cores and fibrillar and amorphous matrix material. The density of both ghosts and more severely damaged peroxisomes was approximately 1.23. Pyrophosphate (pH 9) treatment solubilized the fibrillar content, yielding ghosts that were empty except for cores. Some matrix proteins such as catalase and thiolase readily leak from peroxisomes. Other proteins were identified that remain in mechanically damaged peroxisomes but are neither core nor membrane proteins because they can be released by pyrophosphate treatment. These constitute a class of poorly soluble matrix proteins that appear to correspond to the fibrillar material observed morphologically. All of the peroxisomal beta-oxidation enzymes are located in the matrix, but they vary greatly in how easily they leak out. Palmitoyl coenzyme A synthetase is in the membrane, based on its co-distribution with the 22-kilodalton integral membrane polypeptide. PMID:2989301

1985-01-01

58

Arabidopsis peroxisome proteomics  

PubMed Central

The analytical depth of investigation of the peroxisomal proteome of the model plant Arabidopsis thaliana has not yet reached that of other major cellular organelles such as chloroplasts or mitochondria. This is primarily due to the difficulties associated with isolating and obtaining purified samples of peroxisomes from Arabidopsis. So far only a handful of research groups have been successful in obtaining such fractions. To make things worse, enriched peroxisome fractions frequently suffer from significant organellar contamination, lowering confidence in localization assignment of the identified proteins. As with other cellular compartments, identification of peroxisomal proteins forms the basis for investigations of the dynamics of the peroxisomal proteome. It is therefore not surprising that, in terms of functional analyses by proteomic means, peroxisomes are lagging considerably behind chloroplasts or mitochondria. Alternative strategies are needed to overcome the obstacle of hard-to-obtain organellar fractions. This will help to close the knowledge gap between peroxisomes and other organelles and provide a full picture of the physiological pathways shared between organelles. In this review, we briefly summarize the status quo and discuss some of the methodological alternatives to classic organelle proteomic approaches. PMID:23630535

Bussell, John D.; Behrens, Christof; Ecke, Wiebke; Eubel, Holger

2013-01-01

59

Proteomic Analysis Reveals That the Rab GTPase RabE1c Is Involved in the Degradation of the Peroxisomal Protein Receptor PEX7 (Peroxin 7)*  

PubMed Central

The biogenesis of peroxisomes is mediated by peroxins (PEXs). PEX7 is a cytosolic receptor that imports peroxisomal targeting signal type 2 (PTS2)-containing proteins. Although PEX7 is important for protein transport, the mechanisms that mediate its function are unknown. In this study, we performed proteomic analysis to identify PEX7-binding proteins using transgenic Arabidopsis expressing green fluorescent protein (GFP)-tagged PEX7. Our analysis identified RabE1c, a small GTPase, as a PEX7 binding partner. In vivo analysis revealed that GTP-bound RabE1c binds to PEX7 and that a subset of RabE1c localizes to peroxisomes and interacts with PEX7 on the peroxisome membrane. Unlike endogenous PEX7, which is predominantly localized to the cytosol, GFP-PEX7 accumulates abnormally on the peroxisomal membrane and induces degradation of endogenous PEX7, concomitant with a reduction in import of PTS2-containing proteins and decreased peroxisomal ?-oxidation activity. Thus, GFP-PEX7 on the peroxisomal membrane exerts a dominant negative effect. Mutation of RabE1c restored endogenous PEX7 protein expression and import of PTS2-containing proteins as well as peroxisomal ?-oxidation activity. Treatment with proteasome inhibitors also restored endogenous PEX7 protein levels in GFP-PEX7-expressing seedlings. Based on these findings, we conclude that RabE1c binds PEX7 and facilitates PEX7 degradation in the presence of immobile GFP-PEX7 accumulated at the membrane. PMID:23297417

Cui, Songkui; Fukao, Yoichiro; Mano, Shoji; Yamada, Kenji; Hayashi, Makoto; Nishimura, Mikio

2013-01-01

60

Utility of a topical peroxisome proliferator-activated receptor-? ligand with glucocorticoids in a hapten-induced murine model with features of atopic dermatitis  

PubMed Central

Although topical glucocorticoids (GCs) display potent anti-inflammatory activity in inflamed skin, they also can exert numerous harmful effects on epidermal structure and function. In contrast, topical applications of ligands of peroxisome proliferator-activated receptor-? (PPAR?) not only reduce inflammation, and also improve cutaneous barrier homeostasis. Therefore, we examined whether sequential topical GCs followed by topical Wy14643 (a ligand of PPAR?) might be more effective than either alone for atopic dermatitis (AD) in a hapten (oxazolone)-induced, murine model with multiple features of AD (Ox-AD). Despite expected anti-inflammatory benefits, topical GC alone induced: i) epidermal thinning; ii) reduced expression of involucrin, loricrin and filaggrin; and iii) allowed outside-to-inside penetration of an epicutaneous tracer. While Wy14643 alone yielded significant therapeutic benefits in mice with mild or moderate Ox-AD, it was less effective in severe Ox-AD. Yet, topical applications of Wy14643 after GC was not only significantly effective comparable to GC alone, but it also prevented GC-induced structural and functional abnormalities in permeability barrier homeostasis. Moreover, rebound flares were largely absent after sequential treatment with GC and Wy14643. Together, these results show that GC and PPAR? ligand therapy together is not only effective but also prevents development of GC-induced side effects, including rebound flares, in murine AD. PMID:21633371

Hatano, Yutaka; Elias, Peter M.; Crumrine, Debra; Feingold, Kenneth R.; Katagiri, Kazumoto; Fujiwara, Sakuhei

2011-01-01

61

Activation of peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) induces cell death through MAPK-dependent mechanism in osteoblastic cells  

SciTech Connect

The present study was undertaken to determine the role of the mitogen-activated protein kinase (MAPK) subfamilies in cell death induced by PPAR{gamma} agonists in osteoblastic cells. Ciglitazone and troglitazone, PPAR{gamma} agonists, resulted in a concentration- and time-dependent cell death, which was largely attributed to apoptosis. But a PPAR{alpha} agonist ciprofibrate did not affect the cell death. Ciglitazone caused reactive oxygen species (ROS) generation and ciglitazone-induced cell death was prevented by antioxidants, suggesting an important role of ROS generation in the ciglitazone-induced cell death. ROS generation and cell death induced by ciglitazone were inhibited by the PPAR{gamma} antagonist GW9662. Ciglitazone treatment caused activation of extracellular signal-regulated kinase (ERK) and p38. Activation of ERK was dependent on epidermal growth factor receptor (EGFR) and that of p38 was independent. Ciglitazone-induced cell death was significantly prevented by PD98059, an inhibitor of ERK upstream kinase MEK1/2, and SB203580, a p38 inhibitor. Ciglitazone treatment increased Bax expression and caused a loss of mitochondrial membrane potential, and its effect was prevented by N-acetylcysteine, PD98059, and SB203580. Ciglitazone induced caspase activation, which was prevented by PD98059 and SB203580. The general caspase inhibitor z-DEVD-FMK and the specific inhibitor of caspases-3 DEVD-CHO exerted the protective effect against the ciglitazone-induced cell death. The EGFR inhibitors AG1478 and suramin protected against the ciglitazone-induced cell death. Taken together, these findings suggest that the MAPK signaling pathways play an active role in mediating the ciglitazone-induced cell death of osteoblasts and function upstream of a mitochondria-dependent mechanism. These data may provide a novel insight into potential therapeutic strategies for treatment of osteoporosis.

Kim, Sung Hun [Department of Orthopedic Surgery, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Yoo, Chong Il [Department of Orthopedic Surgery, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Medical Research Institute, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Kim, Hui Taek [Department of Orthopedic Surgery, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Medical Research Institute, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Park, Ji Yeon [Department of Physiology, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Kwon, Chae Hwa [Department of Physiology, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of); Keun Kim, Yong [Department of Physiology, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of) and Medical Research Institute, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of) and MRC for Ischemic Tissue Regeneration, College of Medicine, Pusan National University, Pusan, 602-739 (Korea, Republic of)]. E-mail: kim430@pusan.ac.kr

2006-09-01

62

Peroxisomes take shape  

PubMed Central

Peroxisomes carry out various oxidative reactions that are tightly regulated to adapt to the changing needs of the cell and varying external environments. Accordingly, they are remarkably fluid and can change dramatically in abundance, size, shape and content in response to numerous cues. These dynamics are controlled by multiple aspects of peroxisome biogenesis that are coordinately regulated with each other and with other cellular processes. Ongoing studies are deciphering the diverse molecular mechanisms that underlie biogenesis and how they cooperate to dynamically control peroxisome utility. These important challenges should lead to an understanding of peroxisome dynamics that can be capitalized upon for bioengineering and the development of therapies to improve human health. PMID:24263361

Smith, Jennifer J.; Aitchison, John D.

2014-01-01

63

Peroxisomes in pulmonate gastropods.  

PubMed

Organelles with the morphologic characteristics of peroxisomes have been found in the cells of the kidney sac of two terrestrial pulmonate gastropods. Arion ater and Ariolimax columbianus. These peroxisomes appear in profile as circles or ellipses, 0.25 micron in diameter and 0.3-0.8 micron long; They have a finely granular matrix and a single-limiting membrane; the organelles are extensively associated with smooth endoplasmic reticulum. Some Ariolimax peroxisomes contained structures reminiscent of nucleoids while those of Arion did not. The peroxisomes of Arion ater show a strongly-positive staining reaction with the 3,3'-diaminobenzidine technique, which is inhibited in the presence of aminotriazole. Peroxisomes of Ariolimax columbianus did not show a positive reaction, despite a number of variations of the 3,3'-diaminobenzidine protocol. Speculations are made concerning the biochemical reasons for this cytochemical behavior. Peroxisomes in both tissues were negatively stained while lysosomes were positively stained in acid-phosphatase incubations. PMID:864236

Dannen, E; Beard, M E

1977-05-01

64

Plant Peroxisomes: Biogenesis and Function  

PubMed Central

Peroxisomes are eukaryotic organelles that are highly dynamic both in morphology and metabolism. Plant peroxisomes are involved in numerous processes, including primary and secondary metabolism, development, and responses to abiotic and biotic stresses. Considerable progress has been made in the identification of factors involved in peroxisomal biogenesis, revealing mechanisms that are both shared with and diverged from non-plant systems. Furthermore, recent advances have begun to reveal an unexpectedly large plant peroxisomal proteome and have increased our understanding of metabolic pathways in peroxisomes. Coordination of the biosynthesis, import, biochemical activity, and degradation of peroxisomal proteins allows for highly dynamic responses of peroxisomal metabolism to meet the needs of a plant. Knowledge gained from plant peroxisomal research will be instrumental to fully understanding the organelle’s dynamic behavior and defining peroxisomal metabolic networks, thus allowing the development of molecular strategies for rational engineering of plant metabolism, biomass production, stress tolerance, and pathogen defense. PMID:22669882

Hu, Jianping; Baker, Alison; Bartel, Bonnie; Linka, Nicole; Mullen, Robert T.; Reumann, Sigrun; Zolman, Bethany K.

2012-01-01

65

[Drug induced angioedema (ACE-inhibitors and other)].  

PubMed

Angiotensin Converting Enzyme inhibitors (ACE-I) use is a frequent cause of AE and must be suspected systematically in all patients with AE. The risk of AE is increased in: black people, transplanted patients, those who take gliptins or immunosuppressants (mTOR i). Angiotensin converting enzyme inhibitors induced angioedema (ACE-I AE) can occur a few days to several years after the beginning of this treatment and persist a few months after stopping it. ACE-I AE affect mainly the face and particularly the tongue but also the abdomen. ACE-I AE can be life threatening, due to the involvement of the tongue and the larynx. ACE-I AE must be treated as in the hereditary form when life threatening signs are present, with icatibant or C1 inhibitor concentrate. AE can occur in 10% of angiotensin receptor blockers (ARBs) treated patients who had developed ACE-I AE. PMID:25511647

Fain, Olivier; Mekinian, Arsène; Gobert, Delphine; Khau, Cam-Anh; Javaud, Nicolas

2015-01-01

66

Transcriptome profiling to identify genes involved in peroxisome assembly and function  

PubMed Central

Yeast cells were induced to proliferate peroxisomes, and microarray transcriptional profiling was used to identify PEX genes encoding peroxins involved in peroxisome assembly and genes involved in peroxisome function. Clustering algorithms identified 224 genes with expression profiles similar to those of genes encoding peroxisomal proteins and genes involved in peroxisome biogenesis. Several previously uncharacterized genes were identified, two of which, YPL112c and YOR084w, encode proteins of the peroxisomal membrane and matrix, respectively. Ypl112p, renamed Pex25p, is a novel peroxin required for the regulation of peroxisome size and maintenance. These studies demonstrate the utility of comparative gene profiling as an alternative to functional assays to identify genes with roles in peroxisome biogenesis. PMID:12135984

Smith, Jennifer J.; Marelli, Marcello; Christmas, Rowan H.; Vizeacoumar, Franco J.; Dilworth, David J.; Ideker, Trey; Galitski, Timothy; Dimitrov, Krassen; Rachubinski, Richard A.; Aitchison, John D.

2002-01-01

67

Inhibition of rotavirus ECwt infection in ICR suckling mice by N-acetylcysteine, peroxisome proliferator-activated receptor gamma agonists and cyclooxygenase-2 inhibitors  

PubMed Central

Live attenuated vaccines have recently been introduced for preventing rotavirus disease in children. However, alternative strategies for prevention and treatment of rotavirus infection are needed mainly in developing countries where low vaccine coverage occurs. In the present work, N-acetylcysteine (NAC), ascorbic acid (AA), some nonsteroidal anti-inflammatory drugs (NSAIDs) and peroxisome proliferator-activated receptor gamma (PPAR?) agonists were tested for their ability to interfere with rotavirus ECwt infectivity as detected by the percentage of viral antigen-positive cells of small intestinal villi isolated from ECwt-infected ICR mice. Administration of 6 mg NAC/kg every 8 h for three days following the first diarrhoeal episode reduced viral infectivity by about 90%. Administration of AA, ibuprofen, diclofenac, pioglitazone or rosiglitazone decreased viral infectivity by about 55%, 90%, 35%, 32% and 25%, respectively. ECwt infection of mice increased expression of cyclooxygenase-2, ERp57, Hsc70, NF-?B, Hsp70, protein disulphide isomerase (PDI) and PPAR? in intestinal villus cells. NAC treatment of ECwt-infected mice reduced Hsc70 and PDI expression to levels similar to those observed in villi from uninfected control mice. The present results suggest that the drugs tested in the present work could be assayed in preventing or treating rotaviral diarrhoea in children and young animals. PMID:24037197

Guerrero, Carlos Arturo; Pardo, Paula; Rodriguez, Victor; Guerrero, Rafael; Acosta, Orlando

2013-01-01

68

Mycobacterium tuberculosis 19-kDa lipoprotein induces Toll-like receptor 2-dependent peroxisome proliferator-activated receptor ? expression and promotes inflammatory responses in human macrophages.  

PubMed

Mycobacterium tuberculosis (M.tb) enhances its survival in macrophages by suppressing immune responses, in part through its complex cell wall structures. M.tb 19?kDa lipoprotein (P19), a component of the complex cell wall structures of M.tb, is a Toll?like receptor (TLR) agonist, and may induce immune responses through TLR2. Furthermore, the activation of peroxisome proliferator?activated receptor ? (PPAR?) is also involved in M.tb?induced immune responses in macrophages. In the present study, specific agonists/antagonists and siRNA were used to investigate the role of PPAR? in P19?induced immune responses in human macrophages, including TLR2 activation, p38 phosphorylation and cytokine production. In the present study, PPAR? expression, p38 phosphorylation and cytokine production were upregulated following M.tb H37Rv infection or P19 treatment. By pretreating macrophages with a specific PPAR? agonist or antagonist, it was demonstrated that phosphorylation and IL?6 production are modulated in macrophages by PPAR? activity. Following TLR2 knockdown in macrophages, the expression of PPAR? was significantly decreased in the presence or absence of P19 treatment. Furthermore, p38 phosphorylation and cytokine production were significantly reduced in TLR2 knockdown macrophages following P19 treatment. It was demonstrated in the current study that PPAR? was induced and activated by M.tb infection and that P19?induced PPAR? expression, p38 phosphorylation and cytokine production in macrophages are dependent on TLR2. These findings suggest a role for PPAR? and TLR2 in P19?induced p38 phosphorylation and cytokine production, thereby potentially influencing M.tb pathogenesis. PMID:25504154

Liu, Li; Liu, Jincheng; Niu, Guoqiang; Xu, Qianhong; Chen, Qiliang

2015-04-01

69

[Adverse skin reactions induced by BRAF inhibitors: a systematic review].  

PubMed

Recent developments and therapeutic use of selective BRAF inhibitors (e.g. dabrafenib and vemurafenib) have significantly improved overall survival and disease-free survival of patients with BRAF V600 mutation-positive metastatic melanoma. Despite their survival benefits, small-molecule inhibitors of BRAF are associated with significant and sometimes severe treatment-related dermatological toxicity. The most common adverse skin reactions include photosensitivity, induced malignant lesions of the skin such as keratoacanthomas, squamous cell carcinoma and new primary melanomas, as well as keratinocyte proliferation and differentiation dysfunctions that can manifest as skin papillomas, hand-foot skin reaction, keratosis pilaris-like rash, acantholytic dyskeratosis and cysts of the milia type. In this article, we describe the clinical and histological features of the cutaneous manifestations induced by vemurafenib and dabrafenib on the basis of our clinical experience and a literature review. The crucial role of dermatologists in patient management is also highlighted. PMID:24034635

Sibaud, V; Lamant, L; Maisongrosse, V; Delord, J-P

2013-01-01

70

Cell death is induced by ciglitazone, a peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonist, independently of PPAR{gamma} in human glioma cells  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Greater than 30 {mu}M ciglitazone induces cell death in glioma cells. Black-Right-Pointing-Pointer Cell death by ciglitazone is independent of PPAR{gamma} in glioma cells. Black-Right-Pointing-Pointer CGZ induces cell death by the loss of MMP via decreased Akt. -- Abstract: Peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) regulates multiple signaling pathways, and its agonists induce apoptosis in various cancer cells. However, their role in cell death is unclear. In this study, the relationship between ciglitazone (CGZ) and PPAR{gamma} in CGZ-induced cell death was examined. At concentrations of greater than 30 {mu}M, CGZ, a synthetic PPAR{gamma} agonist, activated caspase-3 and induced apoptosis in T98G cells. Treatment of T98G cells with less than 30 {mu}M CGZ effectively induced cell death after pretreatment with 30 {mu}M of the PPAR{gamma} antagonist GW9662, although GW9662 alone did not induce cell death. This cell death was also observed when cells were co-treated with CGZ and GW9662, but was not observed when cells were treated with CGZ prior to GW9662. In cells in which PPAR{gamma} was down-regulated cells by siRNA, lower concentrations of CGZ (<30 {mu}M) were sufficient to induce cell death, although higher concentrations of CGZ ( Greater-Than-Or-Slanted-Equal-To 30 {mu}M) were required to induce cell death in control T98G cells, indicating that CGZ effectively induces cell death in T98G cells independently of PPAR{gamma}. Treatment with GW9662 followed by CGZ resulted in a down-regulation of Akt activity and the loss of mitochondrial membrane potential (MMP), which was accompanied by a decrease in Bcl-2 expression and an increase in Bid cleavage. These data suggest that CGZ is capable of inducing apoptotic cell death independently of PPAR{gamma} in glioma cells, by down-regulating Akt activity and inducing MMP collapse.

Lee, Myoung Woo; Kim, Dae Seong; Kim, Hye Ryung; Kim, Hye Jin; Yang, Jin Mo; Ryu, Somi; Noh, Yoo Hun; Lee, Soo Hyun; Son, Meong Hi; Jung, Hye Lim; Yoo, Keon Hee [Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)] [Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Koo, Hong Hoe, E-mail: hhkoo@skku.edu [Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Sung, Ki Woong, E-mail: kwsped@skku.edu [Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2012-01-06

71

Induction of Peroxisomes by Butyrate-Producing Probiotics  

PubMed Central

We previously found that peroxisomal biogenesis factor 11a (Pex11a) deficiency is associated with a reduction in peroxisome abundance and impaired fatty acid metabolism in hepatocytes, and results in steatosis. In the present study, we investigated whether butyrate induces Pex11a expression and peroxisome proliferation, and studied its effect on lipid metabolism. C57BL/6 mice fed standard chow or a high-fat diet (HFD) were treated with tributyrin, 4-phelybutyrate acid (4-PBA), or the butyrate-producing probiotics (Clostridium butyricum MIYAIRI 588 [CBM]) plus inulin (dietary fiber), and the body weight, white adipose tissue, serum triglycerides, mRNA expression, and peroxisome abundance were evaluated. Tributyrin or 4-PBA treatment significantly decreased body weight and increased hepatic mRNA expression of peroxisome proliferator-activated receptor-? (PPAR?) and Pex11a. In addition, 4-PBA treatment increased peroxisome abundance and the expression of genes involved in peroxisomal fatty acid ?-oxidation (acyl-coenzyme A oxidase 1 and hydroxysteroid [17-beta] dehydrogenase 4). CBM and inulin administration reduced adipose tissue mass and serum triglycerides, induced Pex11a, acyl-coenzyme A oxidase 1, and hydroxysteroid (17-beta) dehydrogenase 4 genes, and increased peroxisome abundance in mice fed standard chow or an HFD. In conclusion, elevation of butyrate availability (directly through administration of butyrate or indirectly via administration of butyrate-producing probiotics plus fiber) induces PPAR? and Pex11a and the genes involved in peroxisomal fatty acid ?-oxidation, increases peroxisome abundance, and improves lipid metabolism. These results may provide a new therapeutic strategy against hyperlipidemia and obesity. PMID:25659146

Weng, Huachun; Endo, Kosuke; Li, Jiawei; Kito, Naoko; Iwai, Naoharu

2015-01-01

72

No evidence for a role of the peroxisome proliferator-activated receptor gamma (PPARG) and adiponectin (ADIPOQ) genes in antipsychotic-induced weight gain.  

PubMed

Antipsychotics frequently cause changes in glucose metabolism followed by development of weight gain and/or diabetes. Recent findings from our group indicated an influence of glucose-related genes on this serious side effect. With this study, we aimed to extend previous research and performed a comprehensive study on the peroxisome proliferator-activated receptor gamma (PPARG) and the adiponectin (ADIPOQ) genes. In 216 schizophrenic patients receiving antipsychotics for up to 14 weeks, we investigated single-nucleotide polymorphisms in or near PPARG (N=24) and ADIPOQ (N=18). Statistical analysis was done using ANCOVA in SPSS. Haplotype analysis was performed in UNPHASED 3.1.4 and Haploview 4.2. None of the PPARG or ADIPOQ variants showed significant association with antipsychotic-induced weight gain in our combined sample or in a refined subsample of patients of European ancestry treated with clozapine or olanzapine after correction for multiple testing. Similarly, no haplotype association could withstand multiple test correction. Although we could not find a significant influence of ADIPOQ and PPARG on antipsychotic-induced weight gain, our comprehensive examination of these two genes contributes to understanding the biology of this serious side effect. More research on glucose metabolism genes is warranted to elucidate their role in metabolic changes during antipsychotic treatment. PMID:24953421

Brandl, Eva J; Tiwari, Arun K; Zai, Clement C; Chowdhury, Nabilah I; Lieberman, Jeffrey A; Meltzer, Herbert Y; Kennedy, James L; Müller, Daniel J

2014-10-30

73

Involvement of hepatic peroxisome proliferator-activated receptor ?/? in the therapeutic effect of osthole on high-fat and high-sucrose-induced steatohepatitis in rats.  

PubMed

Our previous studies have indicated that osthole may be a dual agonist of peroxisome proliferator-activated receptor (PPAR) ?/? and decrease the hepatic lipid accumulation. But there has been no report about therapeutic effect on steatohepatitis. In the present study, we investigated the action of osthole and its potential mechanisms. The rats with steatohepatitis induced by orally feeding high-fat and high-sucrose emulsion were given osthole 5-20 mg/kg for 4 weeks. The results showed that after treatment with osthole, the serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride (TG), and free fatty acid (FFA) levels, the hepatic TG, FFA, tumor necrosis factor-?, monocyte chemotactic protein-1, interleukin-6, and interleukin-8 contents, and the hepatic weight and liver index were lowered, especially in the osthole 20 mg/kg group. The histological evaluation of liver specimens demonstrated that osthole might improve the hepatic steatosis and inflammation. At the same time, osthole treatment increased the hepatic protein expressions of PPAR?/? and lipoprotein lipase, and decreased the hepatic protein expressions of nuclear factor-?B, sterol regulatory element-binding protein-1c, fatty acid synthase, and diacylglycerol acyltransferase. These findings demonstrate that osthole is effective in treating rat steatohepatitis, and the PPAR?/? may be involved in the osthole-induced modulation of hepatic lipogenic gene expressions and inflammatory cytokine production. PMID:24993341

Zhao, Xi; Xue, Jie; Wang, Xiao-Li; Zhang, Yan; Deng, Min; Xie, Mei-Lin

2014-09-01

74

Cytochemical and biochemical demonstration of an ATPase in membranes of human peroxisomes.  

PubMed

We demonstrated a neutral Mg-ATPase activity in human peroxisomal membranes. To establish the precise experimental conditions for detection of this ATPase, both cytochemical and biochemical characterizations were first carried out in liver peroxisomes from control and cipofibrate-treated rats. The results demonstrated an Mg-ATPase reaction in both normal and proliferated peroxisomes. The nucleotidase activity, with marked preference for ATP, was sensitive to the inhibitors N-ethylmaleimide and 7-chloro-4-nitro-benzo-2-oxadiazole (NBDCl). An ultrastructural cytochemical analysis was developed to evaluate the peroxisomal localization, which localized the reaction product to the peroxisomal membrane. These characteristics can help to differentiate the peroxisomal ATPase from the activity found in mitochondria and endoplasmic reticulum. The conditions established for detecting the rat peroxisomal ATPase were then applied to human peroxisomes isolated from liver and skin fibroblasts in culture. A similar Mg-ATPase activity was readily shown, both cytochemically and biochemically, in the membranes of human peroxisomes. These results, together with previous evidence, strongly support the presence of a specific ATPase in the human peroxisomal membrane. This ATPase may play a crucial role in peroxisome biogenesis. PMID:11850442

Koenig, Cecilia; Araya, Claudia; Skorin, Cetna; Valencia, Claudio; Toro, Andrés; Leighton, Federico; Santos, Manuel J

2002-03-01

75

PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORa (PPARa) AGONISTS DIFFERENTIALLY REGULATE INHIBITOR OF DNA BINDING (ID2) EXPRESSION IN RODENTS AND HUMAN CELLS  

EPA Science Inventory

Abstract Inhibitor of DNA binding (Id2) is a member of the helix-loop-helix (HLH) transcription factor family whose members play important roles in cell differentiation and proliferation. Id2 has been linked to the development of cardiovascular diseases since thiazolidinediones,...

76

A novel sphingosine kinase inhibitor induces autophagy in tumor cells.  

PubMed

The sphingolipids ceramide, sphingosine, and sphingosine 1-phosphate (S1P) regulate cell signaling, proliferation, apoptosis, and autophagy. Sphingosine kinase-1 and -2 (SK1 and SK2) phosphorylate sphingosine to form S1P, shifting the balanced activity of these lipids toward cell proliferation. We have previously reported that pharmacological inhibition of SK activity delays tumor growth in vivo. The present studies demonstrate that the SK2-selective inhibitor 3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide (ABC294640) induces nonapoptotic cell death that is preceded by microtubule-associated protein light chain 3 cleavage, morphological changes in lysosomes, formation of autophagosomes, and increases in acidic vesicles in A-498 kidney carcinoma cells. ABC294640 caused similar autophagic responses in PC-3 prostate and MDA-MB-231 breast adenocarcinoma cells. Simultaneous exposure of A-498 cells to ABC294640 and 3-methyladenine, an inhibitor of autophagy, switched the mechanism of toxicity to apoptosis, but decreased the potency of the SK2 inhibitor, indicating that autophagy is a major mechanism for tumor cell killing by this compound. Induction of the unfolded protein response by the proteasome inhibitor N-(benzyloxycarbonyl)leucinylleucinylleucinal Z-Leu-Leu-Leu-al (MG-132) or the heat shock protein 90 inhibitor geldanamycin synergistically increased the cytotoxicity of ABC294640 in vitro. In severe combined immunodeficient mice bearing A-498 xenografts, daily administration of ABC294640 delayed tumor growth and elevated autophagy markers, but did not increase terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells in the tumors. These data suggest that ABC294640 promotes tumor cell autophagy, which ultimately results in nonapoptotic cell death and a delay of tumor growth in vivo. Consequently, ABC294640 may effectively complement anticancer drugs that induce tumor cell apoptosis. PMID:20179157

Beljanski, Vladimir; Knaak, Christian; Smith, Charles D

2010-05-01

77

Enhanced pan-peroxisome proliferator-activated receptor gene and protein expression in adipose tissue of diet-induced obese mice treated with telmisartan.  

PubMed

Telmisartan has previously been used to target obesity, showing peroxisome proliferator-activated receptor (PPAR) ?/?-related effects in white adipose tissue (WAT). We sought to evaluate whether telmisartan enhances gene and protein expression of all PPAR isoforms in WAT and brown adipose tissue (BAT), as well as their downstream effects upon insulin resistance, adipokine profile and adaptive thermogenesis. Male C57BL/6 mice were fed standard chow (SC; 10% lipids) or high-fat diet (HF; 50% lipids) for 10 weeks. Animals were then randomly allocated into the following four groups: SC, SC-T, HF and HF-T. Telmisartan [10 mg (kg diet)(-1)] was administered for 4 weeks in the diet. Animals in the HF group were overweight and exhibited hypertension, insulin resistance, decreased energy expenditure, a pro-inflammatory adipokine profile and abnormal fat pad mass distribution. Animals in the HF group showed decreased expression of PPAR?, ?/? and ? in WAT and BAT, resulting in impaired glucose uptake and insufficient thermogenesis. Due to the improvement in the adipokine profile and enhanced insulin sensitivity with adequate insulin-stimulated glucose uptake after treatment with telmisartan, the activation of all PPAR isoforms in WAT was beneficial. In BAT, telmisartan induced sustained sympathetic activation, because the ?3-adrenergic receptor was induced by PPAR?/?, while uncoupling protein 1 was induced by PPAR? to promote thermogenesis. Telmisartan exerted anti-obesity effects through higher pan-PPAR gene and protein expression. Upon PPAR?, ?/? and ? (pan-PPAR) agonism in adipose tissue of obese mice, telmisartan ameliorates inflammation and insulin resistance, as well as inducing non-shivering thermogenesis. Our results point to new therapeutic targets for the control of obesity and comorbidities through pan-PPAR-related effects. PMID:25326526

Penna-de-Carvalho, Aline; Graus-Nunes, Francielle; Rabelo-Andrade, Júlia; Mandarim-de-Lacerda, Carlos Alberto; Souza-Mello, Vanessa

2014-12-01

78

A Polypeptide from Tomato Leaves Induces Wound-Inducible Proteinase Inhibitor Proteins  

Microsoft Academic Search

Defensive genes in plants can be activated by several different types of nonpeptide signaling molecules. An endogenous polypeptide, consisting of 18 amino acids, was isolated from tomato leaves and was able at very low concentrations to induce the Synthesis of two wound-inducible proteinase inhibitor proteins when supplied to young tomato plants. The sequence of the polypeptide was determined, and an

Gregory Pearce; Daniel Strydom; Scott Johnson; Clarence A. Ryan

1991-01-01

79

CTSK inhibitor exert its anti-obesity effects through regulating adipocyte differentiation in high-fat diet induced obese mice.  

PubMed

Obesity is associated with increased risk of developing numerous adverse health conditions. Cathepsin k (CTSK) is highly expressed in adipose tissues of obese patients and animal models. Although CTSK has been demonstrated to promote adipocyte differentiation in 3T3-L1 cells, the effects of CTSK selective inhibitor (CKSI) on weight gain and insulin resistance have not been well examined. High-fat diet (HFD) induced obese male C57BL/6 mice were fed a diet with or without CKSI for 8 weeks. The HFD induced increase in adipose tissue weight gain, increase in homeostasis model assessment (HOMA) index as well as accumulation of large adipocytes. After CKSI treatment, all these effects were blunted compared with the HFD control group. A study of the mechanism demonstrated a role for CKSI in significantly down-regulating the expression of two key transcription factors, peroxisome proliferators-activated receptor-? (PPAR?) and CCAAT/enhancer-binding protein ? (C/EBP?), which are markers of adipogenic differentiation. These results indicated that the CKSI possesses an anti-obesity effect, possibly involving the inhibition of adipocyte differentiation. CTSK is likely to be a new target of therapeutic intervention for the treatment of obesity. PMID:25410008

Han, Junfeng; Wei, Li; Xu, Weibin; Lu, Junxi; Wang, Chen; Bao, Yuqian; Jia, Weiping

2014-11-19

80

Over-expression of C/EBP-{alpha} induces apoptosis in cultured rat hepatic stellate cells depending on p53 and peroxisome proliferator-activated receptor-{gamma}  

SciTech Connect

Hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic fibrosis. In our previous studies, CCAAT enhancer binding protein-{alpha} (C/EBP-{alpha}) has been shown to be involved in the activation of HSCs and to have a repression effect on hepatic fibrosis in vivo. However, the mechanisms are largely unknown. In this study, we show that the infection of adenovirus vector expressing C/EBP-{alpha} gene (Ad-C/EBP-{alpha}) could induce HSCs apoptosis in a dose- and time-dependent manner by Annexin V/PI staining, caspase-3 activation assay, and flow cytometry. Also, over-expression of C/EBP-{alpha} resulted in the up-regulation of peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) and P53, while P53 expression was regulated by PPAR-{gamma}. In addition, Fas, FasL, DR4, DR5, and TRAIL were studied. The results indicated that the death receptor pathway was mainly involved and regulated by PPAR-{gamma} and p53 in the process of apoptosis triggered by C/EBP-{alpha} in HSCs.

Wang Xueqing; Huang Guangcun; Mei Shuang; Qian Jin; Ji Juling [Department of Pathology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032 (China); Zhang Jinsheng [Department of Pathology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032 (China)], E-mail: jszhang44@shmu.edu.cn

2009-03-06

81

Antagonist of peroxisome proliferator-activated receptor {gamma} induces cerebellar amyloid-{beta} levels and motor dysfunction in APP/PS1 transgenic mice  

SciTech Connect

Recent evidences show that peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) is involved in the modulation of the amyloid-{beta} (A{beta}) cascade causing Alzheimer's disease (AD) and treatment with PPAR{gamma} agonists protects against AD pathology. However, the function of PPAR{gamma} steady-state activity in A{beta} cascade and AD pathology remains unclear. In this study, an antagonist of PPAR{gamma}, GW9662, was injected into the fourth ventricle of APP/PS1 transgenic mice to inhibit PPAR{gamma} activity in cerebellum. The results show that inhibition of PPAR{gamma} significantly induced A{beta} levels in cerebellum and caused cerebellar motor dysfunction in APP/PS1 transgenic mice. Moreover, GW9662 treatment markedly decreased the cerebellar levels of insulin-degrading enzyme (IDE), which is responsible for the cellular degradation of A{beta}. Since cerebellum is spared from significant A{beta} accumulation and neurotoxicity in AD patients and animal models, these findings suggest a crucial role of PPAR{gamma} steady-state activity in protection of cerebellum against AD pathology.

Du, Jing; Sun, Bing [Protein Science Key Laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, School of Medicine, Tsinghua University, Beijing 100084 (China)] [Protein Science Key Laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, School of Medicine, Tsinghua University, Beijing 100084 (China); Chen, Kui [Department of Pharmacology, Anhui Medical University, Hefei, Anhui 230032 (China)] [Department of Pharmacology, Anhui Medical University, Hefei, Anhui 230032 (China); Fan, Li [Department of Pharmacology, Anhui Medical University, Hefei, Anhui 230032 (China) [Department of Pharmacology, Anhui Medical University, Hefei, Anhui 230032 (China); Cardiovascular Research, Starr Academic Center, Providence Heart and Vascular Institute, Portland, OR 97225 (United States); Wang, Zhao, E-mail: zwang@tsinghua.edu.cn [Protein Science Key Laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, School of Medicine, Tsinghua University, Beijing 100084 (China)] [Protein Science Key Laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, School of Medicine, Tsinghua University, Beijing 100084 (China)

2009-07-03

82

Concurrent Activation of Liver X Receptor and Peroxisome Proliferator-Activated Receptor Alpha Exacerbates Hepatic Steatosis in High Fat Diet-Induced Obese Mice  

PubMed Central

Liver X receptor (LXR) activation improves glucose homeostasis in obesity. This improvement, however, is associated with several side effects including hyperlipidemia and hepatic steatosis. Activation of peroxisome proliferator-activated receptor alpha (PPAR?), on the other hand, increases fatty acid oxidation, leading to a reduction of hyperlipidemia. The objective of this study was to investigate whether concurrent activation of LXR/PPAR? can produce synergistic benefits in treating obesity-associated metabolic disorders. Treatment of high fat diet-induced obese mice with T0901317, an LXR activator, or fenofibrate, the PPAR? agonist, or in combination alleviated insulin resistance and improved glucose tolerance. The combined treatment dramatically exacerbated hepatic steatosis. Gene expression analysis in the liver showed that combined treatment increased the expression of genes involved in lipogenesis and fatty acid transport, including srebp-1c, chrebp, acc1, fas, scd1 and cd36. Histochemistry and ex vivo glycerol releasing assay showed that combined treatment accelerated lipid mobilization in adipose tissue. Combined treatment also increased the transcription of glut4, hsl, atgl and adiponectin, and decreased that of plin1, cd11c, ifn? and leptin. Combined treatment markedly elevated the transcription of fgf21 in liver but not in adipose tissue. These results suggest that concurrent activation of LXR and PPAR? as a strategy to control glucose and lipid metabolism in obesity is beneficial but could lead to elevation of lipid accumulation in the liver. PMID:23762402

Gao, Mingming; Bu, Le; Ma, Yongjie; Liu, Dexi

2013-01-01

83

Onychopathy induced by temsirolimus, a mammalian target of rapamycin inhibitor.  

PubMed

Temsirolimus belongs to the mammalian target of rapamycin (mTOR) inhibitors, targeted therapies for which indications are booming in oncology. While their tolerance is usually good, mucocutaneous toxicity is the most common, including stomatitis, rashes, edemas, pruritus, dry skin and nail disorders. The latter are common in clinical practice but have not yet been well characterized. We report 2 cases of patients who developed, after 6-7 months with temsirolimus, a dystrophy of the 20 nails with fragility, distal onycholysis, yellow discoloration, associated in 1 case with painful paronychia. Topical steroids improved the paronychia, without changing the nail dystrophy. To our knowledge, the occurrence of yellow nail discoloration with temsirolimus has never been reported before. We review the cutaneous and mucosal toxicities induced by temsirolimus and everolimus, two mTOR inhibitors used as anticancer agents and by their parent molecule sirolimus. PMID:22614575

Peuvrel, L; Quéreux, G; Brocard, A; Saint-Jean, M; Dréno, B

2012-01-01

84

Curcumin protects neurons against oxygen-glucose deprivation/reoxygenation-induced injury through activation of peroxisome proliferator-activated receptor-? function.  

PubMed

The turmeric derivative curcumin protects against cerebral ischemic injury. We previously demonstrated that curcumin activates peroxisome proliferator-activated receptor-? (PPAR?), a ligand-activated transcription factor involved in both neuroprotective and anti-inflammatory signaling pathways. This study tested whether the neuroprotective effects of curcumin against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of rat cortical neurons are mediated (at least in part) by PPAR?. Curcumin (10 ?M) potently enhanced PPAR? expression and transcriptional activity following OGD/R. In addition, curcumin markedly increased neuronal viability, as evidenced by decreased lactate dehydrogenase release and reduced nitric oxide production, caspase-3 activity, and apoptosis. These protective effects were suppressed by coadministration of the PPAR? antagonist 2-chloro-5-nitrobenzanilide (GW9662) and by prior transfection of a small-interfering RNA (siRNA) targeting PPAR?, treatments that had no toxic effects on healthy neurons. Curcumin reduced OGD/R-induced accumulation of reactive oxygen species and inhibited the mitochondrial apoptosis pathway, as indicated by reduced release of cytochrome c and apoptosis-inducing factor and maintenance of both the mitochondrial membrane potential and the Bax/Bcl-2 ratio. Again, GW9662 or PPAR? siRNA transfection mitigated the protective effects of curcumin on mitochondrial function. Curcumin suppressed I?B kinase phosphorylation and I?B degradation, thereby inhibiting nuclear factor-? B (NF-?B) nuclear translocation, effects also blocked by GW9662 or PPAR? siRNA. Immunoprecipitation experiments revealed that PPAR? interacted with NF-?B p65 and inhibited NF-?B activation. The present study provides strong evidence that at least some of the neuroprotective effects of curcumin against OGD/R are mediated by PPAR? activation. PMID:24975470

Liu, Zun-Jing; Liu, Hong-Qiang; Xiao, Cheng; Fan, Hui-Zhen; Huang, Qing; Liu, Yun-Hai; Wang, Yu

2014-11-01

85

Analysis of the bioactivity of magnetically immunoisolated peroxisomes.  

PubMed

Peroxisomes produce reactive oxygen species which may participate in biotransformations of innate biomolecules and xenobiotics. Isolating functional peroxisomes with low levels of contaminants would be a useful tool to investigate biotransformations occurring in these organelles that are usually confounded with biotransformations occurring in other co-isolated organelles. Here, we immunoisolate peroxisomes and demonstrate that the impurity level after isolation is low and that peroxisomes retain their biological activity. In this method, an antibody targeting a 70-kDa peroxisomal membrane protein was immobilized to silanized magnetic iron oxide beads (1-4 ?m in diameter) coated with Protein A. Peroxisomes from L6 rat myoblast homogenates were magnetically captured, washed, and then analyzed for subcellular composition using enzymatic assays. Based on the ratio of peroxisomal to lysosomal activity, the retained fraction is 70-fold enriched relative to the unretained fraction. Similarly, the ratio of peroxisomal activity to mitochondrial content suggests that the retained fraction is >30-fold enriched relative to the unretained fraction. H(2)O(2) production from the ?-oxidation of palmitoyl-CoA demonstrated that the isolated peroxisomal fraction was biologically active. Capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) analysis confirmed that the immunopurified fractions were capable of transforming the anticancer drug doxorubicin and the fatty acid analog, BODIPY 500/510 C1C12. Besides its use to investigate peroxisome biotransformations in health and disease, the combination of magnetic immunoisolation with CE-LIF could be widely applicable to investigate subcellular-specific biotransformations of xenobiotics occurring at immunoisolated subcellular compartments. PMID:22065344

Wang, Yaohua; Taylor, Thane H; Arriaga, Edgar A

2012-01-01

86

Peroxisomal ATP Import Is Essential for Seedling Development in Arabidopsis thaliana[W  

PubMed Central

Several recent proteomic studies of plant peroxisomes indicate that the peroxisomal matrix harbors multiple ATP-dependent enzymes and chaperones. However, it is unknown whether plant peroxisomes are able to produce ATP by substrate-level phosphorylation or whether external ATP fuels the energy-dependent reactions within peroxisomes. The existence of transport proteins that supply plant peroxisomes with energy for fatty acid oxidation and other ATP-dependent processes has not previously been demonstrated. Here, we describe two Arabidopsis thaliana genes that encode peroxisomal adenine nucleotide carriers, PNC1 and PNC2. Both proteins, when fused to enhanced yellow fluorescent protein, are targeted to peroxisomes. Complementation of a yeast mutant deficient in peroxisomal ATP import and in vitro transport assays using recombinant transporter proteins revealed that PNC1 and PNC2 catalyze the counterexchange of ATP with ADP or AMP. Transgenic Arabidopsis lines repressing both PNC genes were generated using ethanol-inducible RNA interference. A detailed analysis of these plants showed that an impaired peroxisomal ATP import inhibits fatty acid breakdown during early seedling growth and other ?-oxidation reactions, such as auxin biosynthesis. We show conclusively that PNC1 and PNC2 are essential for supplying peroxisomes with ATP, indicating that no other ATP generating systems exist inside plant peroxisomes. PMID:19073763

Linka, Nicole; Theodoulou, Frederica L.; Haslam, Richard P.; Linka, Marc; Napier, Jonathan A.; Neuhaus, H. Ekkehard; Weber, Andreas P.M.

2008-01-01

87

Peroxisomal cholesterol biosynthesis and Smith-Lemli-Opitz syndrome  

SciTech Connect

Smith-Lemli-Opitz syndrome (SLOS), caused by 7-dehydrocholesterol-reductase (DHCR7) deficiency, shows variable severity independent of DHCR7 genotype. To test whether peroxisomes are involved in alternative cholesterol synthesis, we used [1-{sup 14}C]C24:0 for peroxisomal {beta}-oxidation to generate [1-{sup 14}C]acetyl-CoA as cholesterol precursor inside peroxisomes. The HMG-CoA reductase inhibitor lovastatin suppressed cholesterol synthesis from [2-{sup 14}C]acetate and [1-{sup 14}C]C8:0 but not from [1-{sup 14}C]C24:0, implicating a peroxisomal, lovastatin-resistant HMG-CoA reductase. In SLOS fibroblasts lacking DHCR7 activity, no cholesterol was formed from [1-{sup 14}C]C24:0-derived [1-{sup 14}C]acetyl-CoA, indicating that the alternative peroxisomal pathway also requires this enzyme. Our results implicate peroxisomes in cholesterol biosynthesis but provide no link to phenotypic variation in SLOS.

Weinhofer, Isabelle [Center for Brain Research, Medical University of Vienna, Vienna (Austria); Kunze, Markus [Center for Brain Research, Medical University of Vienna, Vienna (Austria); Stangl, Herbert [Department of Medical Chemistry, Medical University of Vienna, Vienna (Austria); Porter, Forbes D. [National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD (United States); Berger, Johannes [Center for Brain Research, Medical University of Vienna, Vienna (Austria)]. E-mail: johannes.berger@meduniwien.ac.at

2006-06-23

88

PPAR-? Impairment Alters Peroxisome Functionality in Primary Astrocyte Cell Cultures  

PubMed Central

Peroxisomes provide glial cells with protective functions against the harmful effects of H2O2 on neurons and peroxisome impairment results in nervous lesions. Agonists of the ?-subtype of the Peroxisome-Proliferator-Activated-Receptors (PPAR) have been proposed as neuroprotective agents in neurodegenerative disorders. Nevertheless, the role of PPAR-? alterations in pathophysiological mechanisms and the relevance of peroxisome functions in the PPAR-? effects are not yet clear. In a primary cell culture of rat astrocytes, the irreversible PPAR-? antagonist GW9662 concentration-dependently decreased the activity of catalase, the most important antioxidant defense enzyme in peroxisomes. Catalase functionality recovered in a few days and the PPAR-? agonist rosiglitazone promoted reversal of enzymatic damage. The reversible antagonist G3335 reduced both the activity and expression of catalase in a rosiglitazone-prevented manner. G3335 reduced also the glutathione reductase expression, indicating that enzyme involved in glutathione regeneration was compromised. Neither the PPAR-? target gene Acyl-Coenzyme-A-oxidase-1 nor the mitochondrial detoxifying enzyme NADH:ubiquinone-oxidoreductase (NDFUS3) was altered by PPAR-? inhibition. In conclusion, PPAR-? inhibition induced impairment of catalase in astrocytes. A general decrease of the antioxidant defenses of the cell suggests that a PPAR-? hypofunction could participate in neurodegenerative mechanisms through peroxisomal damage. This series of experiments could be a useful model for studying compounds able to restore peroxisome functionality. PMID:24729976

Di Cesare Mannelli, Lorenzo; Zanardelli, Matteo; Micheli, Laura; Ghelardini, Carla

2014-01-01

89

PPAR- ? impairment alters peroxisome functionality in primary astrocyte cell cultures.  

PubMed

Peroxisomes provide glial cells with protective functions against the harmful effects of H2O2 on neurons and peroxisome impairment results in nervous lesions. Agonists of the ? -subtype of the Peroxisome-Proliferator-Activated-Receptors (PPAR) have been proposed as neuroprotective agents in neurodegenerative disorders. Nevertheless, the role of PPAR- ? alterations in pathophysiological mechanisms and the relevance of peroxisome functions in the PPAR- ? effects are not yet clear. In a primary cell culture of rat astrocytes, the irreversible PPAR- ? antagonist GW9662 concentration-dependently decreased the activity of catalase, the most important antioxidant defense enzyme in peroxisomes. Catalase functionality recovered in a few days and the PPAR- ? agonist rosiglitazone promoted reversal of enzymatic damage. The reversible antagonist G3335 reduced both the activity and expression of catalase in a rosiglitazone-prevented manner. G3335 reduced also the glutathione reductase expression, indicating that enzyme involved in glutathione regeneration was compromised. Neither the PPAR- ? target gene Acyl-Coenzyme-A-oxidase-1 nor the mitochondrial detoxifying enzyme NADH:ubiquinone-oxidoreductase (NDFUS3) was altered by PPAR- ? inhibition. In conclusion, PPAR- ? inhibition induced impairment of catalase in astrocytes. A general decrease of the antioxidant defenses of the cell suggests that a PPAR- ? hypofunction could participate in neurodegenerative mechanisms through peroxisomal damage. This series of experiments could be a useful model for studying compounds able to restore peroxisome functionality. PMID:24729976

Di Cesare Mannelli, Lorenzo; Zanardelli, Matteo; Micheli, Laura; Ghelardini, Carla

2014-01-01

90

Rosiglitazone enhances fluorouracil-induced apoptosis of HT29 cells by activating peroxisome proliferator-activated receptor ?  

Microsoft Academic Search

AIM: To examine whether and how rosiglitazone enhances apoptosis induced by fluorouracil in human colon cancer (HT-29) cells. METHODS: Human colon cancer HT-29 cells were cultured in vitro and treated with fluorouracil and\\/or rosiglitazone. Proliferation and growth of HT-29 cells were evaluated by MTT assay and trypan blue exclusion methods, respectively. The apoptosis of HT-29 cells was determined by acridine

Yan-Qin Zhang; Xiao-Qing Tang; Li Sun; Lin Dong; Yong Qin; Hua-Qing Liu; Hong Xia; Jian-Guo Cao

2007-01-01

91

Dual targeting of peroxisomal proteins  

PubMed Central

Cellular compartmentalization into organelles serves to separate biological processes within the environment of a single cell. While some metabolic reactions are specific to a single organelle, others occur in more than one cellular compartment. Specific targeting of proteins to compartments inside of eukaryotic cells is mediated by defined sequence motifs. To achieve multiple targeting to different compartments cells use a variety of strategies. Here, we focus on mechanisms leading to dual targeting of peroxisomal proteins. In many instances, isoforms of peroxisomal proteins with distinct intracellular localization are encoded by separate genes. But also single genes can give rise to differentially localized proteins. Different isoforms can be generated by use of alternative transcriptional start sites, by differential splicing or ribosomal read-through of stop codons. In all these cases different peptide variants are produced, of which only one carries a peroxisomal targeting signal. Alternatively, peroxisomal proteins contain additional signals that compete for intracellular targeting. Dual localization of proteins residing in both the cytoplasm and in peroxisomes may also result from use of inefficient targeting signals. The recent observation that some bona fide cytoplasmic enzymes were also found in peroxisomes indicates that dual targeting of proteins to both the cytoplasm and the peroxisome might be more widespread. Although current knowledge of proteins exhibiting only partial peroxisomal targeting is far from being complete, we speculate that the metabolic capacity of peroxisomes might be larger than previously assumed. PMID:24151469

Ast, Julia; Stiebler, Alina C.; Freitag, Johannes; Bölker, Michael

2013-01-01

92

Mode of action framework analysis for receptor-mediated toxicity: the Peroxisome Proliferator-Activated Receptor alpha (PPARa) as a case study  

EPA Science Inventory

Therapeutic hypolipidemic agents and industrial chemicals that cause peroxisome proliferation and induce liver tumors in rodents activate the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARa). Research has elucidated the cellular and molecular events by w...

93

Proton pump inhibitor-induced subacute cutaneous lupus erythematosus  

PubMed Central

Summary Background Drug-induced subacute cutaneous lupus erythematosus (SCLE) has been known in the literature since 1985 and is increasingly recognized. Objectives To identify and describe patients with proton pump inhibitor (PPI)-induced SCLE. Methods A retrospective medical chart review of patients diagnosed with lupus erythematosus at the Department of Dermatology and Allergy Centre was carried out over a 19-year period. A causality assessment to PPI was performed using the Naranjo probability scale. Results Twenty-four patients with PPI-induced SCLE were identified (21 women and three men). Nineteen patients were newly identified cases, with a mean age of 61 years. These patients had 24 episodes of PPI-induced SCLE comprising lansoprazole (12), omeprazole (six), esomeprazole (four) and pantoprazole (two). Four patients had multiple episodes and three patients reacted to different PPIs. The incubation period was on average 8 months (range 1 week to 3·5 years) and the resolution period was on average 3 months (range 4 weeks to 8 months). Antinuclear antibodies were positive in 61% of tested patients, most frequently with a speckled pattern. Positive anti-Ro/SSA antibodies were found in 73%, anti-La/SSB antibodies in 33% and antihistone antibodies in 8% of tested patients at the time of the eruption. The skin rash was often widespread with a tendency to bullous lesions and focal skin necrosis. Conclusions We present the largest case series of PPI-induced SCLE reported to date, and our patient cohort reveals the lack of attention to this condition. The diagnosis may be suspected on the clinical picture, and most patients have anti-Ro/SSA antibodies, while antihistone antibodies have no value in the diagnostic process. Cross-reactivity can be seen between different PPIs. PMID:24547721

Sandholdt, LH; Laurinaviciene, R; Bygum, A

2014-01-01

94

Aromatase inhibitors-induced bone loss in early breast cancer.  

PubMed

Women with breast cancer have an increased prevalence and incidence of fractures. This increased risk of fracture has become most evident following the use of aromatase inhibitors (AIs) as standard adjuvant therapy. AI-induced bone loss occurs at more than twice the rate of physiologic postmenopausal bone loss. Moreover, peripheral quantitative computed tomography data indicate that effects of AIs on bone strength and on cortical bone have been substantially underestimated by dual-energy X-ray absorptiometry. All AIs have been associated with an increased fracture risk. The incidence of fractures is at least 33-43% higher in AI-treated patients than in tamoxifen-treated patients, and this increase in fracture risk is maintained at least for the duration of AI therapy. Over the last few years, clinical trials have established the effectiveness of bisphosphonates and denosumab to preserve and even increase bone mineral density (BMD) during adjuvant AIs. Most data have been obtained with zoledronic acid administered twice a year, which effectively maintains or increases BMD in women receiving AIs. In addition, zoledronic acid has been shown to delay disease recurrence and maybe prolong survival in women with hormone-responsive tumors, thereby providing an adjuvant antitumor benefit besides preserving BMD. It is likely that a combined fracture risk assessment will more accurately identify women with breast cancer who require bone protective therapy. The FRAX tool probably underestimates the net increase in fracture risk due to AI therapy. Recent guidelines for the prevention of AI-induced bone loss have adequately considered the presence of several established clinical risk factors for fractures, in addition to BMD, when selecting patients to be treated with inhibitors of bone resorption. PMID:24936287

Body, Jean-Jacques

2012-01-01

95

Catalase Deficiency Accelerates Diabetic Renal Injury Through Peroxisomal Dysfunction  

PubMed Central

Mitochondrial reactive oxygen species (ROS) play an important role in diabetes complications, including diabetic nephropathy (DN). Plasma free fatty acids (FFAs) as well as glucose are increased in diabetes, and peroxisomes and mitochondria participate in FFA oxidation in an interconnected fashion. Therefore, we investigated whether deficiency of catalase, a major peroxisomal antioxidant, accelerates DN through peroxisomal dysfunction and abnormal renal FFA metabolism. Diabetes was induced by multiple injections of low-dose streptozotocin into catalase knock-out (CKO) and wild-type (WT) C57BL/6 mice. Murine mesangial cells (MMCs) transfected with catalase small interfering RNA followed by catalase overexpression were used to further elucidate the role of endogenous catalase. Despite equivalent hyperglycemia, parameters of DN, along with markers of oxidative stress, were more accelerated in diabetic CKO mice than in diabetic WT mice up to 10 weeks of diabetes. CKO mice and MMCs showed impaired peroxisomal/mitochondrial biogenesis and FFA oxidation. Catalase deficiency increased mitochondrial ROS and fibronectin expression in response to FFAs, which were effectively restored by catalase overexpression or N-acetylcysteine. These data provide unprecedented evidence that FFA-induced peroxisomal dysfunction exacerbates DN and that endogenous catalase plays an important role in protecting the kidney from diabetic stress through maintaining peroxisomal and mitochondrial fitness. PMID:22315314

Hwang, Inah; Lee, Jiyoun; Huh, Joo Young; Park, Jehyun; Lee, Hi Bahl; Ho, Ye-Shih; Ha, Hunjoo

2012-01-01

96

[The influence of inhibitors of neuronal and inducible NO-synthases on experimental hemorrhagic stroke.  

PubMed

Objectives. To study the effect of inhibitors of neuronal and inducible NO-synthase on the development of hemorrhagic stroke in rats Krushinsky-Molodkina (KM) without adaptation to hypoxia and with short-term adaptation to hypobaric hypoxia. Material and methods. Ninety rats were included in the study. Experiments with short-term adaptation to hypobaric hypoxia were performed on 48 rats. The inhibitor of inducible NO-synthase (aminoguanidine, "Sigma") or the inhibitor of neuronal NO-synthase (7-nitroindasol, "Sigma") were injected in dosage 2.5 mg/100g intraperitoneally. Results. Selective inhibitors of neuronal and inducible NO-synthase had a protective effect on stress injuries in KM rats. The inhibitor of neuronal NO-synthase was more effective than the inhibitor of inducible NO-synthase in the experiments without adaptation to hypoxia. Markedly greater protective effect was achieved by the simultaneous introduction of inhibitors of neuronal and inducible NO-synthase. The greatest protective effect in the development of stress damage in rats of KM was observed in short-term adaptation to hypobaric hypoxia with simultaneous introduction of both inhibitors. Conclusions. It can be assumed that an excessive amount of NO produced by neuronal and inducible NO-synthases during the acoustic exposure in KM rats leads to stress damage. Use of selective inhibitors reduce the excess NO synthesis and the development of audiogenic stress damage caused by hemorrhagic stroke. PMID:25345640

Krushinski?, A L; Kuzenkov, V S; D'iakonova, V E; Reutov, V P

2014-01-01

97

Evolving models for peroxisome biogenesis?  

PubMed Central

Significant progress has been made towards our understanding of the mechanism of peroxisome formation, in particular concerning sorting of peroxisomal membrane proteins, matrix protein import and organelle multiplication. Here we evaluate the progress made in recent years. We focus mainly on progress made in yeasts. We indicate the gaps in our knowledge and discuss conflicting models. PMID:24681485

Hettema, Ewald H; Erdmann, Ralf; van der Klei, Ida; Veenhuis, Marten

2014-01-01

98

Peroxisome Senescence in Human Fibroblasts  

Microsoft Academic Search

The molecular mechanisms of peroxisome biogenesis have begun to emerge; in contrast, relatively little is known about how the organelle functions as cells age. In this report, we characterize age-related changes in peroxisomes of human cells. We show that aging compromises peroxiso- mal targeting signal 1 (PTS1) protein import, affecting in particular the critical antioxidant enzyme catalase. The number and

Julie E. Legakis; Jay I. Koepke; Chris Jedeszko; Ferdous Barlaskar; Laura J. Terlecky; Holly J. Edwards; Paul A. Walton; Stanley R. Terlecky

2002-01-01

99

Hypoxia-inducible factor 1 mediates hypoxia-induced cardiomyocyte lipid accumulation by reducing the DNA binding activity of peroxisome proliferator-activated receptor {alpha}/retinoid X receptor  

SciTech Connect

In response to cellular hypoxia, cardiomyocytes adapt to consume less oxygen by shifting ATP production from mitochondrial fatty acid {beta}-oxidation to glycolysis. The transcriptional activation of glucose transporters and glycolytic enzymes by hypoxia is mediated by hypoxia-inducible factor 1 (HIF-1). In this study, we examined whether HIF-1 was involved in the suppression of mitochondrial fatty acid {beta}-oxidation in hypoxic cardiomyocytes. We showed that either hypoxia or adenovirus-mediated expression of a constitutively stable hybrid form (HIF-1{alpha}/VP16) suppressed mitochondrial fatty acid metabolism, as indicated by an accumulation of intracellular neutral lipid. Both treatments also reduced the mRNA levels of muscle carnitine palmitoyltransferase I which catalyzes the rate-limiting step in the mitochondrial import of fatty acids for {beta}-oxidation. Furthermore, adenovirus-mediated expression of HIF-1{alpha}/VP16 in cardiomyocytes under normoxic conditions also mimicked the reduction in the DNA binding activity of peroxisome proliferator-activated receptor {alpha} (PPAR{alpha})/retinoid X receptor (RXR), in the presence or absence of a PPAR{alpha} ligand. These results suggest that HIF-1 may be involved in hypoxia-induced suppression of fatty acid metabolism in cardiomyocytes by reducing the DNA binding activity of PPAR{alpha}/RXR.

Belanger, Adam J.; Luo Zhengyu; Vincent, Karen A.; Akita, Geoffrey Y.; Cheng, Seng H.; Gregory, Richard J. [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States); Jiang Canwen [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States)], E-mail: canwen.jiang@genzyme.com

2007-12-21

100

Integrin Inhibitor Suppresses Bevacizumab-Induced Glioma Invasion12  

PubMed Central

Glioblastoma is known to secrete high levels of vascular endothelial growth factor (VEGF), and clinical studies with bevacizumab, a monoclonal antibody to VEGF, have demonstrated convincing therapeutic benefits in glioblastoma patients. However, its induction of invasive proliferation has also been reported. We examined the effects of treatment with cilengitide, an integrin inhibitor, on bevacizumab-induced invasive changes in glioma. U87?EGFR cells were stereotactically injected into the brain of nude mice or rats. Five days after tumor implantation, cilengitide and bevacizumab were administered intraperitoneally three times a week. At 18 days after tumor implantation, the brains were removed and observed histopathologically. Next, the bevacizumab and cilengitide combination group was compared to the bevacizumab monotherapy group using microarray analysis. Bevacizumab treatment led to increased cell invasion in spite of decreased angiogenesis. When the rats were treated with a combination of bevacizumab and cilengitide, the depth of tumor invasion was significantly less than with only bevacizumab. Pathway analysis demonstrated the inhibition of invasion-associated genes such as the integrin-mediated cell adhesion pathway in the combination group. This study showed that the combination of bevacizumab with cilengitide exerted its anti-invasive effect. The elucidation of this mechanism might contribute to the treatment of bevacizumab-refractory glioma. PMID:24704537

Ishida, Joji; Onishi, Manabu; Kurozumi, Kazuhiko; Ichikawa, Tomotsugu; Fujii, Kentaro; Shimazu, Yosuke; Oka, Tetsuo; Date, Isao

2014-01-01

101

Inhibitors of N-linked glycosylation induce systemic acquired resistance in cucumber  

Microsoft Academic Search

Localized treatment of cucumber (Cucumis sativus L. cv. Wisonsin) cotyledons with inhibitors of N-glycosylation such as tunicamycin or amphomycin resulted in systemic acquired resistance in the first leaf to the fungal pathogen Colletotrichum lagenarium. Resistance was maximal as early as 2days after application and best results were observed when the inhibitor was used at 100?M. The same treatment also induced

L Sticher; J.-P Metraux

2000-01-01

102

Chondrocyte apoptosis induced by collagen degradation: inhibition by caspase inhibitors and IGF-1  

Microsoft Academic Search

The main objective of this study was to test the effectiveness of candidate apoptosis inhibitors in limiting chondrocyte apoptosis induced by collagen degradation. Primary human chondrocytes were isolated from normal articular cartilage and grown in monolayer culture. Collagenase was added to the cells in the presence and absence of caspase inhibitors and insulin like growth factor (IGF)-1. The amount of

Marvin Y. Lo; Hubert T. Kim

2004-01-01

103

Heat-induced inactivation mechanisms of Kunitz trypsin inhibitor and Bowman-Birk inhibitor in soymilk processing.  

PubMed

Trypsin inhibitor activity (TIA) is an important antinutritional factor in soymilk. In this study, the effects of NaCl preaddition on TIA and the heat-induced TIA inactivation mechanisms were examined. The results showed that Kunitz trypsin inhibitor (KTI) and Bowman-Birk inhibitor (BBI) contributed 74% and 26% to raw soymilk TIA, respectively. The heat-induced quick KTI incorporation into protein aggregates was the reason for its quick TIA inactivation. The heat-induced slow cleavage of one BBI peptide bond was the reason for its slow TIA inactivation. Heat-induced protein aggregate formation had little effect on BBI inactivation owing to the fact that BBI and its degradation product tended to remain in the supernatant (197,000g, 1h) in all conditions used in this study. NaCl could accelerate the KTI incorporation into protein aggregates and the cleavage of one BBI peptide bond, which supplied a simple and quick method for low TIA soymilk processing. PMID:24518322

Chen, Yeming; Xu, Zhicun; Zhang, Caimeng; Kong, Xiangzhen; Hua, Yufei

2014-07-01

104

Healing Impairment Effect of Cyclooxygenase Inhibitors on Dextran Sulfate Sodium-Induced Colitis in Rats  

Microsoft Academic Search

We examined the effects of various cyclooxygenase (COX) inhibitors on the healing of colonic lesions induced by dextran sulfate sodium (DSS) in the rat. Colonic lesions were induced by 2.5% DSS in the drinking water for 7 days, and then the animals were fed with tap water for subsequent 7 days. Indomethacin (a nonselective COX inhibitor), SC-560 (a selective COX-1

Ryoichi Tsubouchi; Shusaku Hayashi; Yoko Aoi; Hikaru Nishio; Shun Terashima; Shinichi Kato; Koji Takeuchi

2006-01-01

105

Damaged peroxisomes are subject to rapid autophagic degradation in the yeast Hansenula polymorpha.  

PubMed

Evidence is accumulating that damaged components of eukaryotic cells are removed by autophagic degradation (e.g., mitophagy). Here we show that peroxisomes that are damaged by the abrupt removal of the membrane protein Pex3 are massively and rapidly degraded even when the cells are placed at peroxisome-inducing conditions and hence need the organelles for growth. Pex3 degradation was induced by a temperature shift using Hansenula polymorpha pex3? cells producing a Pex3 fusion protein containing an N-terminal temperature sensitive degron sequence. The massive peroxisome degradation process, associated with Pex3 degradation, showed properties of both micro- and macropexophagy and was dependent on Atg1 and Ypt7. This mode of peroxisome degradation is of physiological significance as it was also observed at conditions that excessive ROS is formed from peroxisome metabolism, i.e., when methanol-grown wild-type cells are exposed to methanol excess conditions. PMID:21490428

van Zutphen, Tim; Veenhuis, Marten; van der Klei, Ida J

2011-08-01

106

Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors  

SciTech Connect

Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential in As induced VaD.

Sharma, Bhupesh, E-mail: drbhupeshresearch@gmail.com; Sharma, P.M.

2013-11-15

107

Sodium Dodecyl Sulfate Induces Plasminogen Activator Inhibitor Type 2 Expression in Epidermal Keratinocytes In Vivo and In Vitro  

Microsoft Academic Search

The detergent sodium dodecyl sulfate is a well-known inducer of irritant contact dermatitis. In this study we show that sodium dodecyl sulfate induces the serine proteinase inhibitor, plasminogen activator inhibitor type 2, in epidermal keratinocytes. The enhancement in plasminogen activator inhibitor type 2 mRNA and antigen is observed both when sodium dodecyl sulfate is applied topically to normal human skin

Nancy M Chung; Christine M Marshall; James J Leyden; Robert M Lavker; Pamela J Jensen; Barbara C Risse Marsh

2001-01-01

108

Hepatocyte Growth Factor Is a Downstream Effector that Mediates the Antifibrotic Action of Peroxisome Proliferator–Activated Receptor-? Agonists  

PubMed Central

Peroxisome proliferator–activated receptor-? (PPAR-?) is a ligand-dependent transcription factor that plays an important role in the regulation of insulin sensitivity and lipid metabolism. Evidence shows that PPAR-? agonists also ameliorate renal fibrotic lesions in both diabetic nephropathy and nondiabetic chronic kidney disease. However, little is known about the mechanism underlying their antifibrotic action. This study demonstrated that PPAR-? agonists could exert their actions by inducing antifibrotic hepatocyte growth factor (HGF) expression. Incubation of mesangial cells with natural or synthetic PPAR-? agonists 15-deoxy-?12,14-prostaglandin J2 (15d-PGJ2) or troglitazone and ciglitazone suppressed TGF-?1–mediated ?-smooth muscle actin, fibronectin, and plasminogen activator inhibitor-1 expression. PPAR-? agonists also induced HGF mRNA expression and protein secretion. Transfection studies revealed that 15d-PGJ2 stimulated HGF gene promoter activity, which was dependent on the presence of a novel peroxisome proliferator response element. Treatment of mesangial cells with 15d-PGJ2 induced the binding of PPAR-? to the peroxisome proliferator response element in the HGF promoter region. PPAR-? agonists also activated c-met receptor tyrosine phosphorylation, induced Smad transcriptional co-repressor TG-interacting factor expression, and blocked TGF-?/Smad-mediated gene transcription in mesangial cells. Furthermore, ablation of c-met receptor through the LoxP-Cre system in mesangial cells abolished the antifibrotic effect of 15d-PGJ2. PPAR-? activation also induced HGF expression in renal interstitial fibroblasts and repressed TGF-?1–mediated myofibroblast activation. Both HGF and 15d-PGJ2 attenuated Smad nuclear translocation in response to TGF-?1 stimulation in renal fibroblasts. Together, these findings suggest that HGF may act as a downstream effector that mediates the antifibrotic action of PPAR-? agonists. PMID:16291834

Li, Yingjian; Wen, Xiaoyan; Spataro, Bradley C.; Hu, Kebin; Dai, Chunsun; Liu, Youhua

2007-01-01

109

Proteasome inhibitors sensitize ovarian cancer cells to TRAIL induced apoptosis  

Microsoft Academic Search

In the present study we have explored the sensitivity of ovarian cancer cells to TRAIL and proteasome inhibitors. Particularly,\\u000a we have explored the capacity of proteasome inhibitors to bypass TRAIL resistance of ovarian cancer cells. For these studies\\u000a we have used the A2780 ovarian cancer cell line and its chemoresistant derivatives A2780\\/DDP and A2780\\/ADR, providing evidence\\u000a that: (i) the three

Ernestina Saulle; Alessia Petronelli; Luca Pasquini; Eleonora Petrucci; Gualtiero Mariani; Mauro Biffoni; Gianluigi Ferretti; Giovanni Scambia; Pierluigi Benedetti-Panici; Francesco Cognetti; Robin Humphreys; Cesare Peschle; Ugo Testa

2007-01-01

110

15-deoxy-?¹²,¹? -prostaglandin J? inhibits human immunodeficiency virus-1 tat-induced monocyte chemoattractant protein-1/CCL2 production by blocking the extracellular signal-regulated kinase-1/2 signaling pathway independently of peroxisome proliferator-activated receptor-? and heme oxygenase-1 in rat hippocampal slices.  

PubMed

Human immunodeficiency virus (HIV)-induced inflammation, and its consequences within the central nervous system (CNS), must be countered by multiple pharmacologic agents, and 15-deoxy-?(12,14) -prostaglandin J(2) (15d-PGJ2) may hold promise in the treatment of pathologies associated with this inflammatory response. 15d-PGJ2 can repress the inflammatory response by means of peroxisome proliferator-activated receptor-? (PPAR?)-dependent and -independent mechanisms. However, its precise role and antiinflammatory mechanism in the hippocampus remain poorly understood. In the present study, rat hippocampal slices were stimulated with full-length HIV-1 Tat protein to investigate the role of 15d-PGJ2 8in the hippocampal inflammatory response. Pretreatment of slices with 15d-PGJ2 markedly reduced Tat-induced monocyte chemoattractant protein-1 (MCP-1/CCL2) production. Interestingly, the PPAR? antagonist GW9662 did not inhibit action of 15d-PGJ2, confirming the latter's PPAR?-independent mechanism of mediating antiinflammatory effects. Despite 15d-PGJ2's increasing the expression of heme oxygenase-1 (HO-1), its action was not abrogated by the HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX), nor was it recapitulated by HO-1 inducers such as cobalt protoporphyrin (CoPP). Moreover, short interfering RNA (siRNA)-directed knockdown of HO-1 did not abolish the antiinflammatory action of 15d-PGJ2 against Tat-induced MCP-1 production in human microglia-like THP-1 cells. Conversely, 15d-PGJ2 suppressed Tat-induced ERK1/2 activation, decreasing MCP-1 production upon Tat stimulation. The NADPH oxidase inhibitors DPI and apocynin also abrogated Tat-stimulated ERK1/2 activation, reducing MCP-1 production. Collectively, these data demonstrate that the antiinflammatory effects of 15d-PGJ2 on the hippocampus are exerted through inhibition of Tat-mediated ERK1/2 activation, coupled with that of a redox-sensitive pathway, independent of PPAR? and HO-1. PMID:22487967

Kim, Sang Eun; Lee, Eun Ok; Yang, Ji Hye; Kang, Ji Hee Lee; Suh, Yoo-Hun; Chong, Young Hae

2012-09-01

111

Yeast Methylotrophy: Metabolism, Gene Regulation and Peroxisome Homeostasis  

PubMed Central

Eukaryotic methylotrophs, which are able to obtain all the carbon and energy needed for growth from methanol, are restricted to a limited number of yeast species. When these yeasts are grown on methanol as the sole carbon and energy source, the enzymes involved in methanol metabolism are strongly induced, and the membrane-bound organelles, peroxisomes, which contain key enzymes of methanol metabolism, proliferate massively. These features have made methylotrophic yeasts attractive hosts for the production of heterologous proteins and useful model organisms for the study of peroxisome biogenesis and degradation. In this paper, we describe recent insights into the molecular basis of yeast methylotrophy. PMID:21754936

Yurimoto, Hiroya; Oku, Masahide; Sakai, Yasuyoshi

2011-01-01

112

Fis1, DLP1, and Pex11p coordinately regulate peroxisome morphogenesis  

SciTech Connect

Dynamin-like protein 1 (DLP1) and Pex11p{beta} function in morphogenesis of peroxisomes. In the present work, we investigated whether Fis1 is involved in fission of peroxisomes. Endogenous Fis1 was morphologically detected in peroxisomes as well as mitochondria in wild-type CHO-K1 and DLP1-defective ZP121 cells. Subcellular fractionation studies also revealed the presence of Fis1 in peroxisomes. Peroxisomal Fis1 showed the same topology, i.e., C-tail anchored membrane protein, as the mitochondrial one. Furthermore, ectopic expression of FIS1 induced peroxisome proliferation in CHO-K1 cells, while the interference of FIS1 RNA resulted in tubulation of peroxisomes, hence reducing the number of peroxisomes. Fis1 interacted with Pex11p{beta}, by direct binding apparently involving the C-terminal region of Pex11p{beta} in the interaction. Pex11p{beta} also interacted with each other, whereas the binding of Pex11p{beta} to DLP1 was not detectable. Moreover, ternary complexes comprising Fis1, Pex11p{beta}, and DLP1 were detected by chemical cross-linking. We also showed that the highly conserved N-terminal domain of Pex11p{beta} was required for the homo-oligomerization of Pex11p{beta} and indispensable for the peroxisome-proliferating activity. Taken together, these findings indicate that Fis1 plays important roles in peroxisome division and maintenance of peroxisome morphology in mammalian cells, possibly in a concerted manner with Pex11p{beta} and DLP1.

Kobayashi, Shinta [Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 812-8581 (Japan); Tanaka, Atsushi [Department of Biology, Faculty of Sciences, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fujiki, Yukio [Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 812-8581 (Japan) and Department of Biology, Faculty of Sciences, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan) and JST, CREST (Japan)]. E-mail: yfujiscb@mbox.nc.kyushu-u.ac.jp

2007-05-01

113

Peroxisome biogenesis in mammalian cells  

PubMed Central

To investigate peroxisome assembly and human peroxisome biogenesis disorders (PBDs) such as Zellweger syndrome, thirteen different complementation groups (CGs) of Chinese hamster ovary (CHO) cell mutants defective in peroxisome biogenesis have been isolated and established as a model research system. Successful gene-cloning studies by a forward genetic approach utilized a rapid functional complementation assay of CHO cell mutants led to isolation of human peroxin (PEX) genes. Search for pathogenic genes responsible for PBDs of all 14 CGs is now completed together with the homology search by screening the human expressed sequence tag database using yeast PEX genes. Peroxins are divided into three groups: (1) peroxins including Pex3p, Pex16p, and Pex19p, are responsible for peroxisome membrane biogenesis via classes I and II pathways; (2) peroxins that function in matrix protein import; (3) those such as three forms of Pex11p, Pex11p?, Pex11p?, and Pex11p?, are involved in peroxisome proliferation where DLP1, Mff, and Fis1 coordinately function. In membrane assembly, Pex19p forms complexes in the cytosol with newly synthesized PMPs including Pex16p and transports them to the receptor Pex3p, whereby peroxisomal membrane is formed (Class I pathway). Pex19p likewise forms a complex with newly made Pex3p and translocates it to the Pex3p receptor, Pex16p (Class II pathway). In matrix protein import, newly synthesized proteins harboring peroxisome targeting signal type 1 or 2 are recognized by Pex5p or Pex7p in the cytoplasm and are imported to peroxisomes via translocation machinery. In regard to peroxisome-cytoplasmic shuttling of Pex5p, Pex5p initially targets to an 800-kDa docking complex consisting of Pex14p and Pex13p and then translocates to a 500-kDa RING translocation complex. At the terminal step, Pex1p and Pex6p of the AAA family mediate the export of Pex5p, where Cys-ubiquitination of Pex5p is essential for the Pex5p exit. PMID:25177298

Fujiki, Yukio; Okumoto, Kanji; Mukai, Satoru; Honsho, Masanori; Tamura, Shigehiko

2014-01-01

114

Combined Treatment With Peroxisome Proliferator-Activated Receptor (PPAR) Gamma Ligands and Gamma Radiation Induces Apoptosis by PPAR?-Independent Up-Regulation of Reactive Oxygen Species-Induced Deoxyribonucleic Acid Damage Signals in Non-Small Cell Lung Cancer Cells  

SciTech Connect

Purpose: To investigate possible radiosensitizing activities of the well-known peroxisome proliferator-activated receptor (PPAR)? ligand ciglitazone and novel PPAR? ligands CAY10415 and CAY10506 in non-small cell lung cancer (NSCLC) cells. Methods and Materials: Radiosensitivity was assessed using a clonogenic cell survival assay. To investigate the mechanism underlying PPAR? ligand-induced radiosensitization, the subdiploid cellular DNA fraction was analyzed by flow cytometry. Activation of the caspase pathway by combined PPAR? ligands and ?-radiation treatment was detected by immunoblot analysis. Reactive oxygen species (ROS) were measured using 2,7-dichlorodihydrofluorescein diacetate and flow cytometry. Results: The 3 PPAR? ligands induced cell death and ROS generation in a PPAR?-independent manner, enhanced ?-radiation–induced apoptosis and caspase-3–mediated poly (ADP-ribose) polymerase (PARP) cleavage in vitro. The combined PPAR? ligand/?-radiation treatment triggered caspase-8 activation, and this initiator caspase played an important role in the combination-induced apoptosis. Peroxisome proliferator-activated receptor-? ligands may enhance the ?-radiation-induced DNA damage response, possibly by increasing ?-H2AX expression. Moreover, the combination treatment significantly increased ROS generation, and the ROS scavenger N-acetylcysteine inhibited the combined treatment-induced ROS generation and apoptotic cell death. Conclusions: Taken together, these results indicated that the combined treatment of PPAR? ligands and ?-radiation synergistically induced DNA damage and apoptosis, which was regulated by ROS.

Han, Eun Jong; Im, Chang-Nim; Park, Seon Hwa [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Moon, Eun-Yi [Department of Bioscience and Biotechnology, Sejong University, Seoul (Korea, Republic of)] [Department of Bioscience and Biotechnology, Sejong University, Seoul (Korea, Republic of); Hong, Sung Hee, E-mail: gobrian@kcch.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2013-04-01

115

A protease inhibitor against acute stress-induced visceral hypersensitivity and paracellular permeability in rats  

Microsoft Academic Search

In the present study, we investigated the effects of camostat mesilate (CM), a synthetic protease inhibitor, on visceral sensitivity and paracellular permeability induced by the acute restraint stress. We also explored the possible mechanisms underlying these effects. The acute restraint stress was induced by wrapping the fore shoulders, upper forelimbs and thoracic trunk of Sprague–Dawley rats for 2h. Either CM

Juhui Zhao; Jinhai Wang; Lei Dong; Hongyang Shi; Zongyan Wang; Hui Ding; Haitao Shi; Xiaolan Lu

2011-01-01

116

Histone deacetylase inhibitor trichostatin A and proteasome inhibitor PS-341 synergistically induce apoptosis in pancreatic cancer cells  

SciTech Connect

Pancreatic cancer is a common and lethal malignancy. Pancreatic cancer cells overexpress multiple anti-apoptotic factors and death receptor decoys, and are strongly resistant to radiation and to 5-fluorouracil (5-FU)- or gemcitabine (Gem)-based chemotherapy regimens. We have found that low-dose proteasome inhibitor PS-341 and histone deacetylase inhibitor trichostatin A (TSA) synergistically induce cytotoxicity in a panel of eight diverse pancreatic cancer cell lines. Combining TSA with PS-341 effectively inactivated NF{kappa}B signaling, downregulated the predominant endogenous anti-apoptotic factor Bcl-XL overexpression, and disrupted MAP kinase pathway. The combined drug regimen effectively inflicted an average of 71.5% apoptotic cell death (55.2-80%) in diverse pancreatic cancer cell lines by activating the intrinsic apoptotic pathway. Conclusion: the TSA/PS-341 regimen may represent a potential novel therapeutic strategy for pancreatic cancer.

Bai Jirong [Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 0221 (United States)]. E-mail: jbai@bidmc.harvard.edu; Demirjian, Aram [Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 0221 (United States); Sui Jianhua [Dana-Farber Cancer Institute, Harvard Medical School, 330 Brookline Avenue, Boston, MA 0221 (United States); Marasco, Wayne [Dana-Farber Cancer Institute, Harvard Medical School, 330 Brookline Avenue, Boston, MA 0221 (United States); Callery, Mark P. [Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 0221 (United States)]. E-mail: mcallery@bidmc.harvard.ede

2006-10-06

117

Inhibitors of hydroperoxide metabolism enhance ascorbate-induced cytotoxicity.  

PubMed

Pharmacological ascorbate, via its oxidation, has been proposed as a pro-drug for the delivery of H(2)O(2) to tumors. Pharmacological ascorbate decreases clonogenic survival of pancreatic cancer cells, which can be reversed by treatment with scavengers of H(2)O(2). The goal of this study was to determine if inhibitors of intracellular hydroperoxide detoxification could enhance the cytotoxic effects of ascorbate. Human pancreatic cancer cells were treated with ascorbate alone or in combination with inhibitors of hydroperoxide removal including the glutathione disulfide reductase inhibitor 1,3 bis (2-chloroethyl)-1-nitrosurea (BCNU), siRNA targeted to glutathione disulfide reductase (siGR), and 2-deoxy-D-glucose (2DG), which inhibits glucose metabolism. Changes in the intracellular concentration of H(2)O(2) were determined by analysis of the rate of aminotriazole-mediated inactivation of endogenous catalase activity. Pharmacological ascorbate increased intracellular H(2)O(2) and depleted intracellular glutathione. When inhibitors of H(2)O(2) metabolism were combined with pharmacological ascorbate the increase in intracellular H(2)O(2) was amplified and cytotoxicity was enhanced. We conclude that inclusion of agents that inhibit cellular peroxide removal produced by pharmacological ascorbate leads to changes in the intracellular redox state resulting in enhanced cytotoxicity. PMID:23205739

Olney, K E; Du, J; van 't Erve, T J; Witmer, J R; Sibenaller, Z A; Wagner, B A; Buettner, G R; Cullen, J J

2013-03-01

118

Gambogic acid enhances proteasome inhibitor-induced anticancer activity  

PubMed Central

Proteasome inhibition has emerged as a novel approach to anticancer therapy. Numerous natural compounds, such as gambogic acid, have been tested in vitro and in vivo as anticancer agents for cancer prevention and therapy. However, whether gambogic acid has chemosensitizing properties when combined with proteasome inhibitors in the treatment of malignant cells is still unknown. In an effort to investigate this effect, human leukemia K562 cells, mouse hepatocarcinoma H22 cells and H22 cell allografts were treated with gambogic acid, a proteasome inhibitor (MG132 or MG262) or the combination of both, followed by measurement of cellular viability, apoptosis induction and tumor growth inhibition. We report, for the first time, that: (i) the combination of natural product gambogic acid and the proteasome inhibitor MG132 or MG262 results in a synergistic inhibitory effect on growth of malignant cells and tumors in allograft animal models and (ii) there was no apparent systemic toxicity observed in the animals treated with the combination. Therefore, the findings presented in this study demonstrate that natural product gambogic acid is a valuable candidate to be used in combination with proteasome inhibitors, thus representing a compelling anticancer strategy. PMID:21216092

Huang, Hongbiao; Chen, Di; Li, Shujue; Li, Xiaofen; Liu, Ningning; Lu, Xiaoyu; Liu, Shouting; Zhao, Kai; Zhao, Canguo; Guo, Haiping; Yang, Changshan; Zhou, Ping; Dong, Xiaoxian; Zhang, Change; Guanmei; Dou, Q. Ping; Liu, Jinbao

2013-01-01

119

5-Lipoxygenase Inhibitors Attenuate TNF-?-Induced Inflammation in Human Synovial Fibroblasts  

PubMed Central

The lipoxygenase isoform of 5-lipoxygenase (5-LOX) is reported to be overexpressed in human rheumatoid arthritis synovial tissue and involved in the progress of inflammatory arthritis. However, the detailed mechanism of how 5-lipoxygenase regulates the inflammatory response in arthritis synovial tissue is still unclear. The aim of this study was to investigate the involvement of lipoxygenase pathways in TNF-?-induced production of cytokines and chemokines. Human synovial fibroblasts from rheumatoid patients were used in this study. 5-LOX inhibitors and shRNA were used to examine the involvement of 5-LOX in TNF-?-induced cytokines and chemokines expression. The signaling pathways were examined by Western Blotting or immunofluorescence staining. The effect of 5-LOX inhibitor on TNF-?-induced chemokine expression and paw edema was also explored in vivo in C57BL/6 mice. Treatment with 5-LOX inhibitors significantly decreased TNF-?-induced pro-inflammatory mediators including interleukin-6 (IL-6) and monocyte chemo-attractant protein-1 (MCP-1) in human synovial fibroblasts. Knockdown of 5-LOX using shRNA exerted similar inhibitory effects. The abrogation of NF-?B activation was involved in the antagonizing effects of these inhibitors. Furthermore, 5-LOX inhibitor decreased TNF-?-induced up-regulation of serum MCP-1 level and paw edema in mouse model. Our results provide the evidence that the administration of 5-LOX inhibitors is able to ameliorate TNF-?-induced cytokine/chemokine release and paw edema, indicating that 5-LOX inhibitors may be developed for therapeutic treatment of inflammatory arthritis. PMID:25229347

Lin, Han-Ching; Lin, Tzu-Hung; Wu, Ming-Yueh; Chiu, Yung-Cheng; Tang, Chih-Hsin; Hour, Mann-Jen; Liou, Houng-Chi; Tu, Huang-Ju; Yang, Rong-Sen; Fu, Wen-Mei

2014-01-01

120

Hypothermia-induced hyperphosphorylation: a new model to study tau kinase inhibitors.  

PubMed

Tau hyperphosphorylation is one hallmark of Alzheimer's disease (AD) pathology. Pharmaceutical companies have thus developed kinase inhibitors aiming to reduce tau hyperphosphorylation. One obstacle in screening for tau kinase inhibitors is the low phosphorylation levels of AD-related phospho-epitopes in normal adult mice and cultured cells. We have shown that hypothermia induces tau hyperphosphorylation in vitro and in vivo. Here, we hypothesized that hypothermia could be used to assess tau kinase inhibitors efficacy. Hypothermia applied to models of biological gradual complexity such as neuronal-like cells, ex vivo brain slices and adult non-transgenic mice leads to tau hyperphosphorylation at multiple AD-related phospho-epitopes. We show that Glycogen Synthase Kinase-3 inhibitors LiCl and AR-A014418, as well as roscovitine, a cyclin-dependent kinase 5 inhibitor, decrease hypothermia-induced tau hyperphosphorylation, leading to different tau phosphorylation profiles. Therefore, we propose hypothermia-induced hyperphosphorylation as a reliable, fast, convenient and inexpensive tool to screen for tau kinase inhibitors. PMID:22761989

Bretteville, Alexis; Marcouiller, François; Julien, Carl; El Khoury, Noura B; Petry, Franck R; Poitras, Isabelle; Mouginot, Didier; Lévesque, Georges; Hébert, Sébastien S; Planel, Emmanuel

2012-01-01

121

Effects of phospholipase A2 inhibitors on ruthenium red-induced Ca2+ release from mitochondria.  

PubMed

The pharmacologic agents verapamil, nifedipine, diltiazem, prenylamine, N-oleoylethanolamine, R 24571, trifluoperazine, dibucaine, and quinacrine are examined as potential inhibitors of rat liver mitochondrial phospholipase A2 acting on endogenous phospholipid. Their potency as inhibitors of the enzyme is compared to their activities as inhibitors of phospholipase A2-dependent swelling and ruthenium red-induced Ca2+ release in intact mitochondria. For verapamil, diltiazem, trifluoperazine, dibucaine, and quinacrine, there is complete agreement between the relative potencies as inhibitors of phospholipase A2 and the two other processes. Nifedipine and prenylamine, which are weak inhibitors of phospholipase A2, produce a permeable inner membrane, provided that the mitochondrial have accumulated Ca2+. R 24571, which strongly inhibits the enzyme, disrupts mitochondria by a Ca2+-independent mechanism. N-Oleoylethanolamine, which is an effective inhibitor of swelling, does not inhibit phospholipase A2 or ruthenium red-induced Ca2+ release. The results support a proposed scheme wherein ruthenium red-induced Ca2+ release is viewed as reverse activity of the Ca2+-uptake uniporter occurring subsequent to decline in the proton motive force. The latter effect is proposed to arise from a specific phospholipase A2-dependent increase in inner-membrane H+ conductance of mitochondrial subpopulations. It is further shown that mitochondrial membranes display cyclic oscillations in free fatty acid content which are not dependent on the presence of Ca2+ or on the capacity to generate acylcoenzyme A. PMID:2578123

Broekemeier, K M; Schmid, P C; Schmid, H H; Pfeiffer, D R

1985-01-10

122

Irod\\/Ian5: An Inhibitor of  Radiation and Okadaic Acid-induced Apoptosis  

Microsoft Academic Search

Protein phosphatase-directed toxins such as okadaic acid (OA) are general apoptosis inducers. We show that a protein (inhibitor of radiation- and OA-induced apoptosis, Irod\\/Ian5), belonging to the family of immune-associated nucleotide binding proteins, protected Jurkat T-cells against OA- and -radiation-induced apoptosis. Unlike previously described antiapoptotic proteins Irod\\/Ian5 did not protect against anti-Fas, tumor necrosis factor-, staurosporine, UV-light, or a number

Tone Sandal; Linda Aumo; Lars Hedin; Bjørn T. Gjertsen; Stein O. Doskeland

2003-01-01

123

The multikinase inhibitor sorafenib induces caspase-dependent apoptosis in PC-3 prostate cancer cells  

PubMed Central

The present study investigated the effects of the multikinase inhibitor sorafenib on androgen-independent cancer cells viability and intracellular signaling. Human androgen-independent PC-3 prostate cancer cells were treated with sorafenib. At concentration that suppresses extracellular signal-regulated kinase phosphorylation, sorafenib treatment reduced the mitochondrial transmembrane potential. Sorafenib also down-modulated the levels of myeloid cell leukemia 1, survivin and cellular inhibitor of apoptosis protein 2. Sorafenib induced caspase-3 cleavage and the mitochondrial release of cytochrome c. However, no nuclear translocation of apoptosis inducing factor was detected after treatment and the pan-caspase inhibitor Z-VAD-FMK had an obvious protective effect against the drug. In conclusion, sorafenib induces apoptosis through a caspase-dependent mechanism with down-regulated anti-apoptotic proteins in androgen-independent prostate cancer cells in vitro. PMID:20473320

Huang, Rui; Chen, Xue-Qin; Huang, Ying; Chen, Ni; Zeng, Hao

2010-01-01

124

Icatibant in the Treatment of Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema  

PubMed Central

We describe the case of a 75-year-old woman who presented with massive tongue and lip swelling secondary to angiotensin-converting enzyme inhibitor-induced angioedema. An awake fibre-optic intubation was performed because of impending airway obstruction. As there was no improvement in symptoms after 72 hours, the selective bradykinin B2 receptor antagonist icatibant (Firazyr) was administered and the patient's trachea was successfully extubated 36 hours later. To our knowledge this is the first documented case of icatibant being used for the treatment of angiotensin-converting enzyme inhibitor-induced angioedema in the United Kingdom and represents a novel therapeutic option in its management. PMID:25328718

Crooks, Neil H.; Patel, Jaimin; Diwakar, Lavanya; Smith, Fang Gao

2014-01-01

125

TGF-beta inhibition of CTL re-stimulation requires accessory cells and induces peroxisome-proliferator-activated receptor-gamma (PPAR-gamma).  

PubMed

Effective cellular immunity to Epstein-Barr virus (EBV), necessary to prevent or cure many post-transplant lymphoproliferative disorders (PTLD), can be inhibited by transforming growth factor-beta (TGF-beta). In vitro, TGF-beta inhibits memory CTL re-stimulation from whole PBMC. We show that the effect of TGF-beta on CTL re-stimulation is not directly on the T cell, but requires an accessory cell (AC) population. Further, pre-treatment of AC with TGF-beta significantly reduces memory CTL re-stimulation and suppresses delayed type hypersensitivity (DTH) responses. Addition of exogenous interferon-gamma to the AC overcomes the effects of TGF-beta. TGF-beta pre-treatment also up-regulates expression of peroxisome-proliferator-activated receptor-gamma (PPAR-gamma) in CD14(+) AC. Importantly, pre-treatment of AC with the PPAR-gamma ligand, ciglitazone, results in significantly reduced memory CTL re-stimulation. Thus, the effects of TGF-beta in this system may be mediated in part via PPAR-gamma, and PPAR-gamma activation could have significant inhibitory effects on memory T-cell responses by affecting AC function. These data have important implications in understanding how memory CTL are re-stimulated and function to prevent disease, especially PTLD. PMID:16889541

VanBuskirk, A M; Lesinski, G B; Nye, K J; Carson, W E; Yee, L D

2006-08-01

126

SMK-17, a MEK1/2-specific inhibitor, selectively induces apoptosis in ?-catenin-mutated tumors  

PubMed Central

Although clinical studies have evaluated several MEK1/2 inhibitors, it is unlikely that MEK1/2 inhibitors will be studied clinically. BRAF mutations have been proposed as a responder marker of MEK1/2 inhibitors in a preclinical study. However, current clinical approaches focusing on BRAF mutations have shown only moderate sensitivity of MEK1/2 inhibitors. This has led to insufficient support for their promoted clinical adoption. Further characterization of tumors sensitive to MEK inhibitors holds great promise for optimizing drug therapy for patients with these tumors. Here, we report that ?-catenin mutations accelerate apoptosis induced by MEK1/2 inhibitor. SMK-17, a selective MEK1/2 inhibitor, induced apoptosis in tumor cell lines harboring ?-catenin mutations at its effective concentration. To confirm that ?-catenin mutations and mutant ?-catenin-mediated TCF7L2 (also known as TCF4) transcriptional activity is a predictive marker of MEK inhibitors, we evaluated the effects of dominant-negative TCF7L2 and of active, mutated ?-catenin on apoptosis induced by MEK inhibitor. Indeed, dominant-negative TCF7L2 reduced apoptosis induced by MEK inhibitor, whereas active, mutated ?-catenin accelerated it. Our findings show that ?-catenin mutations are an important responder biomarker for MEK1/2 inhibitors. PMID:25640451

Kiga, Masaki; Nakayama, Ayako; Shikata, Yuki; Sasazawa, Yukiko; Murakami, Ryo; Nakanishi, Toshiyuki; Tashiro, Etsu; Imoto, Masaya

2015-01-01

127

15-Deoxy-?12,14-PGJ 2, by activating peroxisome proliferator-activated receptor-gamma, suppresses p22phox transcription to protect brain endothelial cells against hypoxia-induced apoptosis.  

PubMed

15-Deoxy-?(12,14)-PGJ(2) (15d-PGJ(2)) and thiazolidinedione attenuate reactive oxygen species (ROS) production via a peroxisome proliferator-activated receptor-gamma (PPAR-?)-dependent pathway. Nonetheless, how PPAR-? mediates ROS production to ameliorate ischemic brain injury is not clear. Recent studies indicated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the major source of ROS in the vascular system. In the present study, we used an in vitro oxygen-glucose deprivation and reoxygenation (hypoxia reoxygenation [HR]) paradigm to study whether PPAR-? interacts with NADPH oxidase, thereby regulating ROS formation in cerebral endothelial cells (CECs). With pharmacological (PPAR-? antagonist GW9662), loss-of-function (PPAR-? siRNA), and gain-of-function (Ad-PPAR-?) approaches, we first demonstrated that 15d-PGJ(2) protected HR-treated CECs against ROS-induced apoptosis in a PPAR-?-dependent manner. Results of promoter and subcellular localization analyses further revealed that 15d-PGJ(2), by activating PPAR-?, blocked HR-induced NF-?B nuclear translocation, which led to inhibited transcription of the NADPH oxidase subunit p22phox. In summary, we report a novel transrepression mechanism whereby PPAR-? downregulates hypoxia-activated p22phox transcription and the subsequent NADPH oxidase activation, ROS formation, and CEC apoptosis. PMID:24352801

Wu, Jui-Sheng; Tsai, Hsin-Da; Huang, Chien-Yu; Chen, Jin-Jer; Lin, Teng-Nan

2014-08-01

128

Shikonin, dually functions as a proteasome inhibitor and a necroptosis inducer in multiple myeloma cells.  

PubMed

Shikonin (SHK), a natural small agent (MW 288.3), reportedly induces cell death in various tumor cells. We have found that SHK also exerts potent cytocidal effects on human multiple myeloma (MM) cells, but its anticancer mechanism in MM cells remains to be elucidated. SHK at 2.5-5 µM induced apoptosis in seven MM cell lines, including the bortezomib-resistant cell line KMS11/BTZ. The IC50 value of SHK against KMS11/BTZ was comparable to that of a parental cell line KMS11 (1.1 and 1.56 µM, respectively). SHK induces accumulation of ubiquitinated proteins and activates XBP-1 in MM cells, suggesting that SHK functions as a proteasome inhibitor, eventually inducing ER stress-associated apoptosis. SHK increases levels of HSP70/72, which protects cells from apoptosis, and exerts greater cytocidal effects in combination with the HSP70/72 inhibitor VER-155008. At higher concentrations (10-20 µM), SHK induced cell death, which was completely inhibited by a necroptosis inhibitor, necrostatin-1 (Nec-1), while the cytocidal activity was unaffected by Z-VAD-FMK, strongly suggesting that cell death is induced by SHK at high concentrations through necroptosis. The present data show for the first time that SHK induces cell death in MM cells. SHK efficiently induces apoptosis and combination of heat shock protein inhibitor with low dose SHK enhances apoptosis, while high dose SHK induces necroptosis in MM cells. These findings together support the use of SHK as a potential therapeutic agent for MM. PMID:25530098

Wada, Naoko; Kawano, Yawara; Fujiwara, Shiho; Kikukawa, Yoshitaka; Okuno, Yutaka; Tasaki, Masayoshi; Ueda, Mitsuharu; Ando, Yukio; Yoshinaga, Kazuya; Ri, Masaki; Iida, Shinsuke; Nakashima, Takayuki; Shiotsu, Yukimasa; Mitsuya, Hiroaki; Hata, Hiroyuki

2015-03-01

129

Shikonin, dually functions as a proteasome inhibitor and a necroptosis inducer in multiple myeloma cells  

PubMed Central

Shikonin (SHK), a natural small agent (MW 288.3), reportedly induces cell death in various tumor cells. We have found that SHK also exerts potent cytocidal effects on human multiple myeloma (MM) cells, but its anticancer mechanism in MM cells remains to be elucidated. SHK at 2.5–5 ?M induced apoptosis in seven MM cell lines, including the bortezomib-resistant cell line KMS11/BTZ. The IC50 value of SHK against KMS11/BTZ was comparable to that of a parental cell line KMS11 (1.1 and 1.56 ?M, respectively). SHK induces accumulation of ubiquitinated proteins and activates XBP-1 in MM cells, suggesting that SHK functions as a proteasome inhibitor, eventually inducing ER stress-associated apoptosis. SHK increases levels of HSP70/72, which protects cells from apoptosis, and exerts greater cytocidal effects in combination with the HSP70/72 inhibitor VER-155008. At higher concentrations (10–20 ?M), SHK induced cell death, which was completely inhibited by a necroptosis inhibitor, necrostatin-1 (Nec-1), while the cytocidal activity was unaffected by Z-VAD-FMK, strongly suggesting that cell death is induced by SHK at high concentrations through necroptosis. The present data show for the first time that SHK induces cell death in MM cells. SHK efficiently induces apoptosis and combination of heat shock protein inhibitor with low dose SHK enhances apoptosis, while high dose SHK induces necroptosis in MM cells. These findings together support the use of SHK as a potential therapeutic agent for MM. PMID:25530098

WADA, NAOKO; KAWANO, YAWARA; FUJIWARA, SHIHO; KIKUKAWA, YOSHITAKA; OKUNO, YUTAKA; TASAKI, MASAYOSHI; UEDA, MITSUHARU; ANDO, YUKIO; YOSHINAGA, KAZUYA; RI, MASAKI; IIDA, SHINSUKE; NAKASHIMA, TAKAYUKI; SHIOTSU, YUKIMASA; MITSUYA, HIROAKI; HATA, HIROYUKI

2015-01-01

130

BET and HDAC inhibitors induce similar genes and biological effects and synergize to kill in Myc-induced murine lymphoma.  

PubMed

The bromodomain and extraterminal (BET) domain family of proteins binds to acetylated lysines on histones and regulates gene transcription. Recently, BET inhibitors (BETi) have been developed that show promise as potent anticancer drugs against various solid and hematological malignancies. Here we show that the structurally novel and orally bioavailable BET inhibitor RVX2135 inhibits proliferation and induces apoptosis of lymphoma cells arising in Myc-transgenic mice in vitro and in vivo. We find that BET inhibition exhibits broad transcriptional effects in Myc-transgenic lymphoma cells affecting many transcription factor networks. By examining the genes induced by BETi, which have largely been ignored to date, we discovered that these were similar to those induced by histone deacetylase inhibitors (HDACi). HDACi also induced cell-cycle arrest and cell death of Myc-induced murine lymphoma cells and synergized with BETi. Our data suggest that BETi sensitize Myc-overexpressing lymphoma cells partly by inducing HDAC-silenced genes, and suggest synergistic and therapeutic combinations by targeting the genetic link between BETi and HDACi. PMID:24979794

Bhadury, Joydeep; Nilsson, Lisa M; Muralidharan, Somsundar Veppil; Green, Lydia C; Li, Zhoulei; Gesner, Emily M; Hansen, Henrik C; Keller, Ulrich B; McLure, Kevin G; Nilsson, Jonas A

2014-07-01

131

BET and HDAC inhibitors induce similar genes and biological effects and synergize to kill in Myc-induced murine lymphoma  

PubMed Central

The bromodomain and extraterminal (BET) domain family of proteins binds to acetylated lysines on histones and regulates gene transcription. Recently, BET inhibitors (BETi) have been developed that show promise as potent anticancer drugs against various solid and hematological malignancies. Here we show that the structurally novel and orally bioavailable BET inhibitor RVX2135 inhibits proliferation and induces apoptosis of lymphoma cells arising in Myc-transgenic mice in vitro and in vivo. We find that BET inhibition exhibits broad transcriptional effects in Myc-transgenic lymphoma cells affecting many transcription factor networks. By examining the genes induced by BETi, which have largely been ignored to date, we discovered that these were similar to those induced by histone deacetylase inhibitors (HDACi). HDACi also induced cell-cycle arrest and cell death of Myc-induced murine lymphoma cells and synergized with BETi. Our data suggest that BETi sensitize Myc-overexpressing lymphoma cells partly by inducing HDAC-silenced genes, and suggest synergistic and therapeutic combinations by targeting the genetic link between BETi and HDACi. PMID:24979794

Bhadury, Joydeep; Nilsson, Lisa M.; Veppil Muralidharan, Somsundar; Green, Lydia C.; Li, Zhoulei; Gesner, Emily M.; Hansen, Henrik C.; Keller, Ulrich B.; McLure, Kevin G.; Nilsson, Jonas A.

2014-01-01

132

Urate oxidase in peroxisomes from maize root tips  

Microsoft Academic Search

Peroxisomes isolated from maize root tips contained urate oxidase, although the supplementary enzymes allantoinase, allantoicase and NADH-glyoxylate reductase were not detected. Some glutamate-oxalacetate transaminase was present in peroxisomes. Enzymes of two other pathways occuring in plant peroxisomes, namely glycolate metabolism and the glyoxylate cycle, were not present. The root peroxisome thus resembles peroxisomes of the Arum spadix and supports the

Roger W. Parish

1972-01-01

133

In vitro Phosphorylation of Plant Plasma Membrane Proteins in Response to the Proteinase Inhibitor Inducing Factor  

Microsoft Academic Search

A polygalacturonide purified from a tomato leaf pectic polysaccharide that induces the systemic synthesis of proteinase inhibitors in tomato plants enhances the phosphorylation of specific proteins in plasma membrane fractions isolated from tomato and potato leaves. In tomato plasma membranes, two proteins of 34 and 29 kDa show enhanced phosphorylation in response to the polyuronide. In potato plasma membranes, only

Edward E. Farmer; Gregory Pearce; Clarence A. Ryan

1989-01-01

134

Thyroid Hormone Is an Inhibitor of Estrogen-Induced Degradation of Estrogen Receptor-Protein: Estrogen-  

E-print Network

Thyroid Hormone Is an Inhibitor of Estrogen-Induced Degradation of Estrogen Receptor- Protein in the control of receptor transcriptional activation function. Herein, we report that thyroid hormone can of the pituitary. The stabilization of ER pro- tein by thyroid hormone represents a selective blockade against

Alarid, Elaine T.

135

Adalimumab Induced Subcutaneous Nodular Sarcoidosis; A Rare Side Effect of Tumor Necrosis Factor-? Inhibitor  

PubMed Central

Adalimumab and other tumor necrosis factor-? inhibitors have been shown in the recent years to successfully treat sarcoidosis refractory to systemic corticosteroids and other agents. However, there have been an increasing number of cases of sarcoidosis paradoxically induced by these agents. It is hypothesized that this is due to the disruption of the fine balance of cytokines involved in granuloma formation. We describe the first case of adalimumab-induced subcutaneous nodular sarcoidosis in a patient with pulmonary sarcoidosis. PMID:25363227

Au, Sonoa; Mirsaeidi, Mehdi; Aronson, Iris K; Sweiss, Nadera J.

2014-01-01

136

A Novel and Selective Poly (ADP-Ribose) Polymerase Inhibitor Ameliorates Chemotherapy-Induced Painful Neuropathy  

PubMed Central

Background Chemotherapy-induced neuropathy is the principle dose limiting factor requiring discontinuation of many chemotherapeutic agents, including cisplatin and oxaliplatin. About 30 to 40% of patients receiving chemotherapy develop pain and sensory changes. Given that poly (ADP-ribose) polymerase (PARP) inhibition has been shown to provide neuroprotection, the current study was developed to test whether the novel PARP inhibitor compound 4a (analog of ABT-888) would attenuate pain in cisplatin and oxaliplatin-induced neuropathy in mice. Results An established chemotherapy-induced painful neuropathy model of two weekly cycles of 10 intraperitoneal (i.p.) injections separated by 5 days rest was used to examine the therapeutic potential of the PARP inhibitor compound 4a. Behavioral testing using von Frey, paw radiant heat, cold plate, and exploratory behaviors were taken at baseline, and followed by testing at 3, 6, and 8 weeks from the beginning of drug treatment. Conclusion Cisplatin-treated mice developed heat hyperalgesia and mechanical allodynia while oxaliplatin-treated mice exhibited cold hyperalgesia and mechanical allodynia. Co-administration of 50 mg/kg or 25 mg/kg compound 4a with platinum regimen, attenuated cisplatin-induced heat hyperalgesia and mechanical allodynia in a dose dependent manner. Similarly, co-administration of 50 mg/kg compound 4a attenuated oxaliplatin-induced cold hyperalgesia and mechanical allodynia. These data indicate that administration of a novel PARP inhibitor may have important applications as a therapeutic agent for human chemotherapy-induced painful neuropathy. PMID:23326593

Ta, Lauren E.; Schmelzer, James D.; Bieber, Allan J.; Loprinzi, Charles L.; Sieck, Gary C.; Brederson, Jill D.; Low, Philip A.; Windebank, Anthony J.

2013-01-01

137

HDAC inhibitor-induced drug resistance involving ATP-binding cassette transporters (Review)  

PubMed Central

Histone deacetylase (HDAC) inhibitors are becoming a novel and promising class of antineoplastic agents that have been used for cancer therapy in the clinic. Two HDAC inhibitors, vorinostat and romidepsin, have been approved by the Food and Drug Administration to treat T-cell lymphoma. Nevertheless, similar to common anticancer drugs, HDAC inhibitors have been found to induce multidrug resistance (MDR), which is an obstacle for the success of chemotherapy. The most common cause of MDR is considered to be the increased expression of adenosine triphosphate binding cassette (ABC) transporters. Numerous studies have identified that the upregulation of ABC transporters is often observed following treatment with HDAC inhibitors, particularly the increased expression of P-glycoprotein, which leads to drug efflux, reduces intracellular drug concentration and induces MDR. The present review summarizes the key ABC transporters involved in MDR following various HDAC inhibitor treatments in a range of cancer cell lines and also explored the potential mechanisms that result in MDR, including the effect of nuclear receptors, which are the upstream regulatory factors of ABC transporters.

NI, XUAN; LI, LI; PAN, GUOYU

2015-01-01

138

Import of proteins into the peroxisomal matrix  

PubMed Central

Peroxisomes constitute a dynamic compartment in all nucleated cells. They fulfill diverse metabolic tasks in response to environmental changes and cellular demands. This adaptation is implemented by modulation of the enzyme content of the organelles, which is accomplished by dynamically operating peroxisomal protein transport machineries. Soluble import receptors recognize their newly synthesized cargo proteins in the cytosol and ferry them to the peroxisomal membrane. Subsequently, the cargo is translocated into the matrix, where the receptor is ubiquitinated and exported back to the cytosol for further rounds of matrix protein import. This review discusses the recent progress in our understanding of the peroxisomal matrix protein import and its regulation by ubiquitination events as well as the current view on the translocation mechanism of folded proteins into peroxisomes. This article is part of a Special Issue entitled: Origin and spatiotemporal dynamics of the peroxisomal endomembrane system. PMID:24069002

Hasan, Sohel; Platta, Harald W.; Erdmann, Ralf

2013-01-01

139

The interaction between Helminthosporium carbonum and maize: Induced resistance and the role of an inhibitor  

SciTech Connect

Helminthosporium carbonum race 1 produces large, necrotic lesions on susceptible leaves of maize, whereas race 2 causes small, chlorotic flecks. Resistance to race 1 on susceptible leaves was induced when race 2 was inoculated for at least 10 h prior to a challenge inoculation with the pathogen and was manifest as a decrease in the number of appressoria and reduced penetration by race 1 conidia. Induced resistance was prevented or reversed when HC-toxin was added to challenge race 1 inoculum. The basis for protection appears to be a volatile, inhibitory compound produced by the host. This inhibitor was always associated with treatments that resulted in resistance, whereas no inhibitory activity was detected in diffusates from susceptible reactions. The appearance of inhibitor in diffusates coincided with the appearance of protection on the leaf. In addition to race 2 of H. carbonum, other fungi (H. victoriae, H. turcicum, and Alternaria) also induced production of the inhibitor as well as resistance to race 1. The inhibitor prevented the germination of conidia of all fungi tested. The growth of two phytopathogenic bacteria was also completely inhibited. Incorporation of {sup 3}H-leucine and {sup 14}C-uridine into protein and RNA, respectively, by conidia of H. carbonum was prevented within 15 min of exposure to inhibitor. In addition, respiration of conidia in inhibitor was reduced within 90 min to just 25% of the rate of conidia germinated in water. However, inhibitory activity of the diffusates was readily reversed when conidia were rinsed with water or when organic or amino acids were added to inhibited conidia. The addition of sodium acetate to race 2 and race 1 inocula resulted in lesion enlargement and also nullified inhibitory activity in vitro.

Cantone, F.A.

1989-01-01

140

Paradoxical Reaction to Golimumab: Tumor Necrosis Factor ? Inhibitor Inducing Psoriasis Pustulosa  

PubMed Central

Importance Golimumab is a human monoclonal antibody, used for rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis. Adverse reactions are increasing with this class of medication (tumor necrosis factor ? inhibitors). Observations The authors present a case of a female patient who presented with psoriasis pustulosa after the use of golimumab for rheumatoid arthritis. Conclusions and Relevance Paradoxically, in this case, golimumab, which is used for psoriasis, induced the pustular form of this disease. We are observing an increasing number of patients who develop collateral effects with tumor necrosis factor ? inhibitors, and the understanding of the mechanism of action and how these adverse reactions occur may contribute to avoid these sometimes severe situations. PMID:24348382

Soto Lopes, Marien Siqueira; Trope, Beatriz Moritz; Rochedo Rodriguez, Maria Paula Rua; Grynszpan, Rachel Lima; Cuzzi, Tullia; Ramos-e-Silva, Marcia

2013-01-01

141

Treatment of hypertension and renal injury induced by the angiogenesis inhibitor sunitinib: preclinical study.  

PubMed

Common adverse effects of angiogenesis inhibition are hypertension and renal injury. To determine the most optimal way to prevent these adverse effects and to explore their interdependency, the following drugs were investigated in unrestrained Wistar Kyoto rats exposed to the angiogenesis inhibitor sunitinib: the dual endothelin receptor antagonist macitentan; the calcium channel blocker amlodipine; the angiotensin-converting enzyme inhibitor captopril; and the phosphodiesterase type 5 inhibitor sildenafil. Mean arterial pressure was monitored telemetrically. After 8 days, rats were euthanized and blood samples and kidneys were collected. In addition, 24-hour urine samples were collected. After sunitinib start, mean arterial pressure increased rapidly by ?30 mm Hg. Coadministration of macitentan or amlodipine largely prevented this rise, whereas captopril or sildenafil did not. Macitentan, captopril, and sildenafil diminished the sunitinib-induced proteinuria and endothelinuria and glomerular intraepithelial protein deposition, whereas amlodipine did not. Changes in proteinuria and endothelinuria were unrelated. We conclude that in our experimental model, dual endothelin receptor antagonism and calcium channel blockade are suitable to prevent angiogenesis inhibition-induced hypertension, whereas dual endothelin receptor antagonism, angiotensin-converting enzyme inhibitor, and phosphodiesterase type 5 inhibition can prevent angiogenesis inhibition-induced proteinuria. Moreover, the variable response of hypertension and renal injury to different antihypertensive agents suggests that these side effects are, at least in part, unrelated. PMID:25185126

Lankhorst, Stephanie; Kappers, Mariëtte H W; van Esch, Joep H M; Smedts, Frank M M; Sleijfer, Stefan; Mathijssen, Ron H J; Baelde, Hans J; Danser, A H Jan; van den Meiracker, Anton H

2014-12-01

142

Ibulocydine Is a Novel Prodrug Cdk Inhibitor That Effectively Induces Apoptosis in Hepatocellular Carcinoma Cells*  

PubMed Central

Hepatocellular carcinoma (HCC) is frequently associated with abnormalities in cell cycle regulation, leading to increased activity of cyclin-dependent kinases (Cdks) due to the loss, or low expression of, Cdk inhibitors. In this study, we showed that ibulocydine (an isobutyrate prodrug of the specific Cdk inhibitor, BMK-Y101) is a candidate anti-cancer drug for HCC. Ibulocydine has high activity against Cdk7/cyclin H/Mat1 and Cdk9/cyclin T. Ibulocydine inhibited the growth of HCC cells more effectively than other Cdk inhibitors, including olomoucine and roscovitine, whereas ibulocydine as well as the other Cdk inhibitors and BMK-Y101 minimally influenced the growth of normal hepatocyte cells. Ibulocydine induced apoptosis in HCC cells, most likely by inhibiting Cdk7 and Cdk9. In vitro treatment of HCC cells with ibulocydine rapidly blocked phosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II, a process mediated by Cdk7/9. Anti-apoptotic gene products such as Mcl-1, survivin, and X-linked IAP (XIAP) are crucial for the survival of many cell types, including HCC. Following the inhibition of RNA polymerase II phosphorylation, ibulocydine caused rapid down-regulation of Mcl-1, survivin, and XIAP, thus inducing apoptosis. Furthermore, ibulocydine effectively induced apoptosis in HCC xenografts with no toxic side effects. These results suggest that ibulocydine is a strong candidate anti-cancer drug for the treatment of HCC. PMID:21478145

Cho, Seung-Ju; Kim, Young-Jong; Surh, Young-Joon; Kim, B. Moon; Lee, Seung-Ki

2011-01-01

143

Wound-induced Accumulation of Trypsin Inhibitor Activities in Plant Leaves  

PubMed Central

Proteinase inhibitor-inducing factor (PIIF)-induced accumulation of trypsin inhibitory activity was assayed in leaves of 23 species of plants representing 10 agriculturally important genera. Inhibitory activity was assayed in extracts from attached leaves or from excised leaves supplied through the cut petioles for 30 minutes with extracts containing the wound hormone PIIF, obtained from either tomato leaves or from the leaves of each plant under study. During subsequent incubation in light for 72 hours, PIIF-induced trypsin inhibitory activity accumulated in significant quantities in 10 of the 23 species. Alfalfa accumulated the highest levels of inhibitory activity (340 ?g trypsin inhibited/ml leaf juice), followed by tobacco, tomato, potato, strawberry, cucumber, squash, clover, broadbean, and grape. It is suggested that the inhibitors might be classed as allelochemics that are present in certain plants and not others in response to environmental pressures during their evolution. PMID:16659868

Walker-Simmons, Mary; Ryan, Clarence A.

1977-01-01

144

Lucanthone Is a Novel Inhibitor of Autophagy That Induces Cathepsin D-mediated Apoptosis*  

PubMed Central

Cellular stress induced by nutrient deprivation, hypoxia, and exposure to many chemotherapeutic agents activates an evolutionarily conserved cell survival pathway termed autophagy. This pathway enables cancer cells to undergo self-digestion to generate ATP and other essential biosynthetic molecules to temporarily avoid cell death. Therefore, disruption of autophagy may sensitize cancer cells to cell death and augment chemotherapy-induced apoptosis. Chloroquine and its analog hydroxychloroquine are the only clinically relevant autophagy inhibitors. Because both of these agents induce ocular toxicity, novel inhibitors of autophagy with a better therapeutic index are needed. Here we demonstrate that the small molecule lucanthone inhibits autophagy, induces lysosomal membrane permeabilization, and possesses significantly more potent activity in breast cancer models compared with chloroquine. Exposure to lucanthone resulted in processing and recruitment of microtubule-associated protein 1 light chain 3 (LC3) to autophagosomes, but impaired autophagic degradation as revealed by transmission electron microscopy and the accumulation of p62/SQSTM1. Microarray analysis, qRT-PCR, and immunoblotting determined that lucanthone stimulated a large induction in cathepsin D, which correlated with cell death. Accordingly, knockdown of cathepsin D reduced lucanthone-mediated apoptosis. Subsequent studies using p53+/+ and p53?/? HCT116 cells established that lucanthone induced cathepsin D expression and reduced cancer cell viability independently of p53 status. In addition, lucanthone enhanced the anticancer activity of the histone deacetylase inhibitor vorinostat. Collectively, our results demonstrate that lucanthone is a novel autophagic inhibitor that induces apoptosis via cathepsin D accumulation and enhances vorinostat-mediated cell death in breast cancer models. PMID:21148553

Carew, Jennifer S.; Espitia, Claudia M.; Esquivel, Juan A.; Mahalingam, Devalingam; Kelly, Kevin R.; Reddy, Guru; Giles, Francis J.; Nawrocki, Steffan T.

2011-01-01

145

Dual targeting of yeast catalase A to peroxisomes and mitochondria.  

PubMed Central

Yeast catalase A (Cta1p) contains two peroxisomal targeting signals (SSNSKF) localized at its C-terminus and within the N-terminal third of the protein, which both can target foreign proteins to peroxisomes. In the present study we demonstrated that Cta1p can also enter mitochondria, although the enzyme lacks a classical mitochondrial import sequence. Cta1p co-targeting was studied in a catalase A null mutant after growth on different carbon sources, and expression of a Cta1p-GFP (green fluorescent protein)-fusion protein or a Cta1p derivative containing either a c-Myc epitope (Cta1p(myc)) or a SKF-extended tag (Cta1p(myc-SKF)). Peroxisomal and mitochondrial co-import of catalase A were tested qualitatively by fluorescence microscopy and functional complementation of a Delta cta1 null mutation, and quantitatively by subcellular fractionation followed by Western blot analysis and enzyme activity assays. Efficient Cta1p import into peroxisomes was observed when cells were cultivated under peroxisome-inducing conditions (i.e. growth on oleate), whereas significant co-import of Cta1p-GFP into mitochondria occurred when cells were grown under respiratory conditions that favour oxygen stress and ROS (reactive oxygen species) accumulation within this organelle. In particular, when cells were grown on the non-fermentable carbon source raffinose, respiration is maximally enhanced, and catalase A was efficiently targeted to the mitochondrial matrix where it presumably functions as scavenger of H2O2 and mitochondrial-derived ROS. PMID:14998369

Petrova, Ventsislava Y; Drescher, Diane; Kujumdzieva, Anna V; Schmitt, Manfred J

2004-01-01

146

A novel histone deacetylase inhibitor Chidamide induces apoptosis of human colon cancer cells  

SciTech Connect

Many studies have demonstrated that histone deacetylase (HDAC) inhibitors induce various tumor cells to undergo apoptosis, and such inhibitors have been used in different clinical trials against different human cancers. In this study, we designed and synthesized a novel HDAC inhibitor, Chidamide. We showed that Chidamide was able to increase the acetylation levels of histone H3 and to inhibit the PI3K/Akt and MAPK/Ras signaling pathways, which resulted in arresting colon cancer cells at the G1 phase of the cell cycle and promoting apoptosis. As a result, the proliferation of colon cancer cells was suppressed in vitro. Our data support the potential application of Chidamide as an anticancer agent in treating colon cancer. Future studies are needed to demonstrate its in vivo efficacy.

Liu, Lin [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China)] [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China); Chen, Baoan, E-mail: wenyu811@126.com [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China)] [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China); Qin, Shukui [Chinese PLA Cancer Center, The 81st PLA Hospital, Nanjing 210002, Jiangsu (China)] [Chinese PLA Cancer Center, The 81st PLA Hospital, Nanjing 210002, Jiangsu (China); Li, Suyi; He, Xiangming [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China)] [Department of Oncology, Zhong-Da Hospital of Southeast University, Nanjing 210009, Jiangsu (China); Qiu, Shaomin; Zhao, Wei; Zhao, Hong [Department of Internal Medicine, Nanjing Municipal Cancer Hospital, Nanjing 210003, Jiangsu (China)] [Department of Internal Medicine, Nanjing Municipal Cancer Hospital, Nanjing 210003, Jiangsu (China)

2010-02-05

147

Peroxisome proliferator-activated receptor-? agonists modulate CXCL9 and CXCL11 chemokines in Graves' ophthalmopathy fibroblasts and preadipocytes.  

PubMed

Peroxisome proliferator-activated receptors (PPAR)? have been shown to exert immunomodulatory effects in autoimmune disorders; no study evaluated the effect of PPAR? activation in Graves' ophthalmopathy (GO). We show the presence of PPAR?, ? and ? in GO fibroblasts and preadipocytes. PPAR? activators have a potent inhibitory action on the secretion of CXCL9 and CXCL11 chemokines (induced by IFN? and TNF?) in fibroblasts and preadipocytes. The potency of the used PPAR? agonists was maximum on the secretion of CXCL11 (67% inhibition by fenofibrate) in fibroblasts. The relative potency of the compounds in GO fibroblasts was different with each chemokine. PPAR? agonists were stronger inhibitors of CXCL9 and CXCL11 (in GO fibroblasts and preadipocytes) than PPAR? activators. This study first shows that PPAR? activators inhibit CXCL9 and CXCL11 chemokines in normal and GO fibroblasts and preadipocytes, suggesting that PPAR? may be involved in the modulation of the immune response in GO. PMID:22101320

Antonelli, Alessandro; Ferrari, Silvia Martina; Frascerra, Silvia; Ruffilli, Ilaria; Gelmini, Stefania; Minuto, Michele; Pupilli, Cinzia; Miccoli, Paolo; Sellari-Franceschini, Stefano; Ferrannini, Ele; Fallahi, Poupak

2012-02-26

148

Apoptosis induced by SRC-family tyrosine kinase inhibitors in cultured rat cortical cells.  

PubMed

In the central nervous system, members of the Src family of tyrosine kinases (SFKs) are widely expressed and are abundant in neurons. The purpose of this study is to examine whether glycogen synthase-3 (GSK-3) is involved in SFK inhibitor-induced apoptosis. PP2 and SU6656, SFK inhibitors, increased apoptotic cell death with morphological changes that were characterized by cell shrinkage, chromatin condensation, or nuclear fragmentation. Moreover, both activation of caspase-9 and caspase-3 were accompanied by the cell death. GSK-3 inhibitors, such as alsterpaullone and SB216763, prevented the PP2-induced apoptosis. In addition, insulin-like growth factor-I prevented the PP2-induced cell death and PP2 inhibited phosphorylation of focal adhesion kinase (FAK). Phosphorylation of FAK on Tyr 576 by Src activates FAK. These results suggest that inhibition of SFK induces apoptosis possibly via blocking of FAK/phosphatidylinositol-3 kinase/Akt signaling pathway and activation of GSK-3 is involved in the cell death in rat cortical neurons. PMID:22006118

Takadera, Tsuneo; Fujibayashi, Mineki; Koriyama, Yoshiki; Kato, Satoru

2012-04-01

149

Histone deacetylase inhibitors induce apoptosis in both Type I and Type II endometrial cancer cells  

PubMed Central

Objective To characterize the molecular pathways involved in apoptosis following administration of histone deacetylase inhibitors to Type I and II endometrial cancer cells. Methods Ark2, Ishikawa, and AN3 cell lines representing both Type I and II endometrial cancers were treated with various concentrations of oxamflatin and HDAC inhibitor-1. Cell apoptosis was determined by flow cytometry, nuclear staining, Western blotting, and mitochondrial membrane potential assays. Results Compared to controls, there was a 95% reduction in the growth of Ark2 cells following administration of histone deacetylase inhibitors and this response was dose-dependent. These agents also caused profound morphologic changes and loss of mitochondrial membrane potentials consistent with the induction of apoptosis. Cleavage of PARP, caspase-9, and caspase-8 was detected, confirming the activation of apoptotic cascades in endometrial carcinoma cells. This effect was present in both serous and endometrioid cell types. Conclusion Our results suggest that oxamflatin and HDAC inhibitor-1 have potent cytotoxicity in endometrial cancer cells by inducing cell apoptosis. Histone deacetylase inhibitors are promising agents for the treatment of both Type I and II endometrial carcinoma. PMID:17303224

Jiang, Shujuan; Dowdy, Sean C.; Meng, Xue W.; Wang, Zhaoyu; Jones, Monica B.; Podratz, Karl C.; Jiang, Shi-Wen

2012-01-01

150

Permeability properties of peroxisomal membranes from yeasts.  

PubMed

We have studied the permeability properties of intact peroxisomes and purified peroxisomal membranes from two methylotrophic yeasts. After incorporation of sucrose and dextran in proteoliposomes composed of asolectin and peroxisomal membranes isolated from the yeasts Hansenula polymorpha and Candida boidinii a selective leakage of sucrose occurred indicating that the peroxisomal membranes were permeable to small molecules. Since the permeability of yeast peroxisomal membranes in vitro may be due to the isolation procedure employed, the osmotic stability of peroxisomes was tested during incubations of intact protoplasts in hypotonic media. Mild osmotic swelling of the protoplasts also resulted in swelling of the peroxisomes present in these cells but not in a release of their matrix proteins. The latter was only observed when the integrity of the cells was disturbed due to disruption of the cell membrane during further lowering of the concentration of the osmotic stabilizer. Stability tests with purified peroxisomes indicated that this leak of matrix proteins was not associated with the permeability to sucrose. Various attempts to mimic the in vivo situation and generate a proton motive force across the peroxisomal membranes in order to influence the permeability properties failed. Two different proton pumps were used for this purpose namely bacteriorhodopsin (BR) and reaction center-light-harvesting complex I (RCLH1 complex). After introduction of BR into the membrane of intact peroxisomes generation of a pH-gradient was not or barely detectable. Since this pump readily generated a pH-gradient in pure liposomes, these results strengthened the initial observations on the leakiness of the peroxisomal membrane fragments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2339956

Douma, A C; Veenhuis, M; Sulter, G J; Waterham, H R; Verheyden, K; Mannaerts, G P; Harder, W

1990-01-01

151

Dipeptidyl Peptidase IV Inhibitor MK-0626 Attenuates Pancreatic Islet Injury in Tacrolimus-Induced Diabetic Rats  

PubMed Central

Background Tacrolimus (TAC)-induced pancreatic islet injury is one of the important causes of new-onset diabetes in transplant recipients. This study was performed to evaluate whether a dipeptidyl peptidase IV (DPP IV) inhibitor is effective in improving TAC-induced diabetes mellitus by reducing pancreatic islet injury. Methods Rats were treated with TAC (1.5 mg/kg, subcutaneously) and the DPP IV inhibitor MK-0626 (10 or 20 mg/kg, oral gavage) for 4 weeks. The effect of MK-0626 on TAC-induced diabetes was evaluated by assessing pancreatic islet function, histopathology. TAC-induced incretin dysfunction was also examined based on active glucagon-like peptide-1 (GLP-1) levels in the serum after glucose loading. The protective effect of MK-0626 was evaluated by measuring markers of oxidative stress, oxidative resistance, and apoptosis. To determine whether enhanced GLP-1 signaling is associated with these protective effects, we measured the expression of the GLP-1 receptor (GLP-1R) and the effect of the GLP-1 analog exendin-4 on cell viability and oxidative stress in isolated islets. Results MK-0626 treatment attenuated TAC-induced pancreatic islet dysfunction and islet morphology. TAC treatment led to a defect in active GLP-1 secretion; however, MK-0626 reversed these effects. TAC treatment increased the level of 8-hydroxy-2?-deoxyguanosine (8-OHdG), the number of apoptotic death, and the level of active caspase-3, and decreased the level of manganese superoxide dismutase and heme oxygenase-1; MK-0626 treatment reversed these changes. MK-0626 treatment restored the expression of GLP-1R, and direct administration of exendin-4 to isolated islets reduced TAC-induced cell death and 8-OHdG expression. Conclusions The DPP IV inhibitor MK-0626wasan effective antidiabetic agent that exerted antioxidative and antiapoptotic effects via enhanced GLP-1 signaling in TAC-induced diabetics. PMID:24959755

Doh, Kyoung Chan; Piao, Shang Guo; Jin, Jian; Heo, Seong Beom; Chung, Byung Ha; Yang, Chul Woo

2014-01-01

152

Peroxisome division in the yeast Yarrowia lipolytica is regulated by a signal from inside the peroxisome  

PubMed Central

We describe an unusual mechanism for organelle division. In the yeast Yarrowia lipolytica, only mature peroxisomes contain the complete set of matrix proteins. These mature peroxisomes assemble from several immature peroxisomal vesicles in a multistep pathway. The stepwise import of distinct subsets of matrix proteins into different immature intermediates along the pathway causes the redistribution of a peroxisomal protein, acyl-CoA oxidase (Aox), from the matrix to the membrane. A significant redistribution of Aox occurs only in mature peroxisomes. Inside mature peroxisomes, the membrane-bound pool of Aox interacts with Pex16p, a membrane-associated protein that negatively regulates the division of early intermediates in the pathway. This interaction inhibits the negative action of Pex16p, thereby allowing mature peroxisomes to divide. PMID:14504266

Guo, Tong; Kit, Yuriy Y.; Nicaud, Jean-Marc; Le Dall, Marie-Therese; Sears, S. Kelly; Vali, Hojatollah; Chan, Honey; Rachubinski, Richard A.; Titorenko, Vladimir I.

2003-01-01

153

Ultrastructural and cytochemical demonstration of peroxisomes in cultured fibroblasts from patients with peroxisomal deficiency disorders  

PubMed Central

The oxidation of very long chain fatty acids and synthesis of ether glycerolipids (plasmalogens) occurs mainly in peroxisomes. Zellweger's cerebrohepatorenal syndrome (CHRS) is a rare, inherited metabolic disease characterized by an apparent absence of peroxisomes, an accumulation of very long chain fatty acids, and a decrease of plasmalogens in tissues and cultured fibroblasts from these patients. As peroxisomes are ubiquitous in mammalian cells, we examined normal and CHRS-cultured fibroblasts for their presence, using an electron microscopic histochemical procedure for the subcellular localization of catalase, a peroxisomal marker enzyme. Small (0.08-0.20 micron) round or slightly oval peroxisomes were seen in both normal and CHRS fibroblasts. The number of peroxisomes was analyzed morphometrically and found to be significantly reduced in all CHRS cell lines. These results are discussed in relation to the underlying defect in peroxisomal function and biogenesis in this disease. PMID:3988808

1985-01-01

154

Xanthoangelols isolated from Angelica keiskei inhibit inflammatory-induced plasminogen activator inhibitor 1 (PAI-1) production.  

PubMed

The folk medicine Angelica keiskei (Ashitaba) exhibits antitumor, antioxidant and antidiabetic activities and it has recently attracted attention as a health food. Ashitaba is thought to have antithrombotic properties, but this has not yet been scientifically proven. The elevation of plasma plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis results in a predisposition to the risk of thrombosis. The present study showed that Ashitaba exudates injected intraperitoneally and orally administered over long-term suppressed the lipopolysaccharide (LPS) induced PAI-1 increase in mouse plasma. We also found that xanthoangelol, xanthoangelols B and D, the components of Ashitaba exudates, significantly inhibited TNF?-induced PAI-1 production from human umbilical vein endothelial cells (HUVECs). These findings suggest that Ashitaba can decrease elevated PAI-1 production, and that daily consumption of Ashitaba product might maintain anticoagulant status by inhibiting elevations in PAI-1 under inflammatory conditions. PMID:22038782

Ohkura, Naoki; Nakakuki, Yoshitaka; Taniguchi, Masahiko; Kanai, Shiho; Nakayama, Akiko; Ohnishi, Katsunori; Sakata, Toshiyuki; Nohira, Tomoyoshi; Matsuda, Juzo; Baba, Kimiye; Atsumi, Gen-Ichi

2011-01-01

155

Nifedipine inhibits advanced glycation end products (AGEs) and their receptor (RAGE) interaction-mediated proximal tubular cell injury via peroxisome proliferator-activated receptor-gamma activation  

SciTech Connect

Research highlights: {yields} Nifedipine inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma}. {yields} GW9662 treatment alone increased RAGE mRNA levels in tubular cells. {yields} Nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-{kappa}B activation and increases in intercellular adhesion molecule-1 and transforming growth factor-{beta} gene expression in tubular cells, all of which were blocked by GW9662. -- Abstract: There is a growing body of evidence that advanced glycation end products (AGEs) and their receptor (RAGE) interaction evokes oxidative stress generation and subsequently elicits inflammatory and fibrogenic reactions, thereby contributing to the development and progression of diabetic nephropathy. We have previously found that nifedipine, a calcium-channel blocker (CCB), inhibits the AGE-induced mesangial cell damage in vitro. However, effects of nifedipine on proximal tubular cell injury remain unknown. We examined here whether and how nifedipine blocked the AGE-induced tubular cell damage. Nifedipine, but not amlodipine, a control CCB, inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}). GW9662 treatment alone was found to increase RAGE mRNA levels in tubular cells. Further, nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-{kappa}B activation and increases in intercellular adhesion molecule-1 and transforming growth factor-beta gene expression in tubular cells, all of which were blocked by GW9662. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-oxidative and anti-inflammatory agent against AGEs in tubular cells by suppressing RAGE expression via PPAR{gamma} activation.

Matsui, Takanori [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan)] [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan); Yamagishi, Sho-ichi, E-mail: shoichi@med.kurume-u.ac.jp [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan)] [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan); Takeuchi, Masayoshi [Department of Pathophysiological Science, Faculty of Pharmaceutical Science, Hokuriku University, Kanazawa (Japan)] [Department of Pathophysiological Science, Faculty of Pharmaceutical Science, Hokuriku University, Kanazawa (Japan); Ueda, Seiji; Fukami, Kei; Okuda, Seiya [Department of Medicine, Kurume University School of Medicine, Kurume (Japan)] [Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

2010-07-23

156

A newly discovered function of peroxisomes  

PubMed Central

In plants, peroxisomes are the organelles involved in various metabolic processes and physiological functions including ?-oxidation, mobilization of seed storage lipids, photorespiration, and hormone biosynthesis. We have recently shown that, in fungi and plants, peroxisomes play a vital role in biosynthesis of biotin, an essential cofactor required for various carboxylation and decarboxylation reactions. In fungi, the mutants defective in peroxisomal protein import exhibit biotin auxotrophy. The fungal BioF protein, a 7-keto-8-aminopelargonic acid (KAPA) synthase catalyzing the conversion of pimeloyl-CoA to KAPA in biotin biosynthesis, contains the peroxisomal targeting sequence 1 (PTS1), and its peroxisomal targeting is required for biotin biosynthesis. In plants, biotin biosynthesis is essential for embryo development. We have shown that the peroxisomal targeting sequences of the BioF proteins are conserved throughout the plant kingdom, and the Arabidopsis thaliana BioF protein is indeed localized in peroxisomes. Our findings suggest that peroxisomal localization of the BioF protein is evolutionarily conserved among eukaryotes, and required for biotin biosynthesis and plant growth and development. PMID:23073000

Maruyama, Jun-ichi; Yamaoka, Shohei; Matsuo, Ichiro; Tsutsumi, Nobuhiro; Kitamoto, Katsuhiko

2012-01-01

157

Effects of the NF-B Inhibitor Pyrrolidine Dithiocarbamate on Experimentally Induced Autoimmune Anterior Uveitis  

Microsoft Academic Search

PURPOSE. To determine the effect of pyrrolidine dithiocarba- mate (PDTC), a nuclear factor (NF)-B inhibitor, on chemokine and chemokine receptor expression and thus elucidate the role of NF-B in the pathogenesis of experimental autoimmune anterior uveitis (EAAU). METHODS. Uveitis was induced in Lewis rats with the injection of melanin-associated antigen into the footpad. PDTC (200 mg\\/kg and 100 mg\\/kg) was

Chang-Hao Yang; I-Mo Fang; Chang-Pin Lin; Chung-May Yang; Muh-Shy Chen

2005-01-01

158

Echinomycin, a Small-Molecule Inhibitor of Hypoxia-Inducible Factor1 DNA-Binding Activity  

Microsoft Academic Search

The identification of small molecules that inhibit the sequence- specific binding of transcription factors to DNA is an attractive approach for regulation of gene expression. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that controls genes involved in glycolysis, angiogenesis, migration, and invasion, all ofwhichareimportantfortumorprogressionandmetastasis.To identify inhibitors of HIF-1 DNA-binding activity, we expressed truncated HIF-1A and HIF-1B proteins containing the basic-

Dehe Kong; Eun Jung Park; Andrew G. Stephen; Maura Calvani; John H. Cardellina; Robert J. Fisher; Robert H. Shoemaker; Giovanni Melillo

2005-01-01

159

The Calpain Inhibitor MDL28170 Induces the Expression of Apoptotic Markers in Leishmania amazonensis Promastigotes  

PubMed Central

Background Human cutaneous leishmaniasis is caused by distinct species, including Leishmania amazonensis. Treatment of cutaneous leishmaniasis is far from satisfactory due to increases in drug resistance and relapses, and toxicity of compounds to the host. As a consequence for this situation, the development of new leishmanicidal drugs and the search of new targets in the parasite biology are important goals. Methodology/Principal Findings In this study, we investigated the mechanism of death pathway induced by the calpain inhibitor MDL28170 on Leishmania amazonensis promastigote forms. The combined use of different techniques was applied to contemplate this goal. MDL28170 treatment with IC50 (15 µM) and two times the IC50 doses induced loss of parasite viability, as verified by resazurin assay, as well as depolarization of the mitochondrial membrane, which was quantified by JC-1 staining. Scanning and transmission electron microscopic images revealed drastic alterations on the parasite morphology, some of them resembling apoptotic-like death, including cell shrinking, surface membrane blebs and altered chromatin condensation pattern. The lipid rearrangement of the plasma membrane was detected by Annexin-V labeling. The inhibitor also induced a significant increase in the proportion of cells in the sub-G0/G1 phase, as quantified by propidium iodide staining, as well as genomic DNA fragmentation, detected by TUNEL assay. In cells treated with MDL28170 at two times the IC50 dose, it was also possible to observe an oligonucleossomal DNA fragmentation by agarose gel electrophoresis. Conclusions/Significance The data presented in the current study suggest that MDL28170 induces apoptotic marker expression in promastigotes of L. amazonensis. Altogether, the results described in the present work not only provide a rationale for further exploration of the mechanism of action of calpain inhibitors against trypanosomatids, but may also widen the investigation of the potential clinical utility of calpain inhibitors in the chemotherapy of leishmaniases. PMID:24498160

Marinho, Fernanda A.; Gonçalves, Keyla C. S.; Oliveira, Simone S. C.; Gonçalves, Diego S.; Matteoli, Filipe P.; Seabra, Sergio H.; Oliveira, Ana Carolina S.; Bellio, Maria; Oliveira, Selma S.; Souto-Padrón, Thaïs; d'Avila-Levy, Claudia M.; Santos, André L. S.; Branquinha, Marta H.

2014-01-01

160

Age-dependent roles of peroxisomes in the hippocampus of a transgenic mouse model of Alzheimer’s disease  

PubMed Central

Background Alzheimer’s Disease (AD) is a progressive neurodegenerative disease, especially affecting the hippocampus. Impairment of cognitive and memory functions is associated with amyloid ?-peptide-induced oxidative stress and alterations in lipid metabolism. In this scenario, the dual role of peroxisomes in producing and removing ROS, and their function in fatty acids ?-oxidation, may be critical. This work aims to investigating the possible involvement of peroxisomes in AD onset and progression, as studied in a transgenic mouse model, harboring the human Swedish familial AD mutation. We therefore characterized the peroxisomal population in the hippocampus, focusing on early, advanced, and late stages of the disease (3, 6, 9, 12, 18 months of age). Several peroxisome-related markers in transgenic and wild-type hippocampal formation were comparatively studied, by a combined molecular/immunohistochemical/ultrastructural approach. Results Our results demonstrate early and significant peroxisomal modifications in AD mice, compared to wild-type. Indeed, the peroxisomal membrane protein of 70 kDa and acyl-CoA oxidase 1 are induced at 3 months, possibly reflecting the need for efficient fatty acid ?-oxidation, as a compensatory response to mitochondrial dysfunction. The concomitant presence of oxidative damage markers and the altered expression of antioxidant enzymes argue for early oxidative stress in AD. During physiological and pathological brain aging, important changes in the expression of peroxisome-related proteins, also correlating with ongoing gliosis, occur in the hippocampus. These age- and genotype-based alterations, strongly dependent on the specific marker considered, indicate metabolic and/or numerical remodeling of peroxisomal population. Conclusions Overall, our data support functional and biogenetic relationships linking peroxisomes to mitochondria and suggest peroxisomal proteins as biomarkers/therapeutic targets in pre-symptomatic AD. PMID:23374228

2013-01-01

161

Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves.  

PubMed

Inducible defensive responses in plants are known to be activated locally and systemically by signaling molecules that are produced at sites of pathogen or insect attacks, but only one chemical signal, ethylene, is known to travel through the atmosphere to activate plant defensive genes. Methyl jasmonate, a common plant secondary compound, when applied to surfaces of tomato plants, induces the synthesis of defensive proteinase inhibitor proteins in the treated plants and in nearby plants as well. The presence of methyl jasmonate in the atmosphere of chambers containing plants from three species of two families, Solanaceae and Fabaceae, results in the accumulation of proteinase inhibitors in leaves of all three species. When sagebrush, Artemisia tridentata, a plant shown to possess methyl jasmonate in leaf surface structures, is incubated in chambers with tomato plants, proteinase inhibitor accumulation is induced in the tomato leaves, demonstrating that interplant communication can occur from leaves of one species of plant to leaves of another species to activate the expression of defensive genes. PMID:11607107

Farmer, E E; Ryan, C A

1990-10-01

162

Effect of ethylene action inhibitors upon wound-induced gene expression in tomato pericarp  

SciTech Connect

The contribution of wound-ethylene to wound-induced gene expression was investigated in unripe tomato pericarp using inhibitors of ethylene action. Wounded unripe tomato pericarp was treated with 2,5-norbornadiene or silver thiosulfate to inhibit specifically the induction of ethylene-dependent mRNA species. Poly(A){sup +} RNAs isolated from these tissues after 12 hours of wounding were translated in vitro in a rabbit reticulocyte lysate system and ({sup 35}S)methionine-labeled polypeptides were compared to unwounded controls after separation by one and two-dimensional polyacrylamide gel electrophoresis. Results show that mechanical wounding induces a dramatic shift in gene expression (over 50 mRNA species) but expression of less than 15% of these genes is affected by the treatment with ethylene action inhibitors. A selective decrease in mRNAs coding for a 37 kilodalton doublet and 75 kilodalton polypeptides is observed in 2,5-norbornadiene and silver thiosulfate treated wounded pericarp. Levels of hydroxyproline-rich glycoprotein mRNAs induced in wounded tissue were not influenced by inhibitors of ethylene action.

Henstrand, J.M.; Handa, A.K. (Purdue Univ., West Lafayette, IN (USA))

1989-09-01

163

Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves.  

PubMed Central

Inducible defensive responses in plants are known to be activated locally and systemically by signaling molecules that are produced at sites of pathogen or insect attacks, but only one chemical signal, ethylene, is known to travel through the atmosphere to activate plant defensive genes. Methyl jasmonate, a common plant secondary compound, when applied to surfaces of tomato plants, induces the synthesis of defensive proteinase inhibitor proteins in the treated plants and in nearby plants as well. The presence of methyl jasmonate in the atmosphere of chambers containing plants from three species of two families, Solanaceae and Fabaceae, results in the accumulation of proteinase inhibitors in leaves of all three species. When sagebrush, Artemisia tridentata, a plant shown to possess methyl jasmonate in leaf surface structures, is incubated in chambers with tomato plants, proteinase inhibitor accumulation is induced in the tomato leaves, demonstrating that interplant communication can occur from leaves of one species of plant to leaves of another species to activate the expression of defensive genes. PMID:11607107

Farmer, E E; Ryan, C A

1990-01-01

164

ACE inhibitor-induced intestinal angio-oedema: rare adverse effect of a common drug.  

PubMed

ACE inhibitors are the leading cause of drug-induced angio-oedema in the USA. ACE inhibitor-induced intestinal angio-oedema, a much rarer complication of this medication, has been reported. The author reports a patient presenting with a 1-day history of severe abdominal pain. The patient was started on lisinopril 2 days prior to this presentation. Computer axial tomography (CAT) scan of the abdomen demonstrated extensive and marked thickening, and oedema involving the duodenum and proximal jejunum associated with significant mesenteric oedema. Concerns for visceral angio-oedema and a possible association with lisinopril according to the Naranjo algorithm were raised. Lisinopril was discontinued and the patient was treated with antihistamines. The patient improved clinically in the next 24 h and discharged home with education and documentation of this serious allergy. ACE inhibitor-induced visceral angio-oedema is under-reported and most often missed resulting in waste of hospital resources towards working up this clinical diagnosis. PMID:23878294

Shahani, Lokesh

2013-01-01

165

Discovery of Indenopyrazoles as a New Class of Hypoxia Inducible Factor (HIF)-1 Inhibitors  

PubMed Central

The indenopyrazole framework was investigated as a new class of HIF-1? inhibitors. Indenopyrazole 2l was found to most strongly inhibit the hypoxia-induced HIF-1? transcriptional activity (IC50 = 0.014 ?M) among all of the known compounds having relatively simple structures, unlike manassantins. Indenopyrazole 2l suppressed HIF-1? transcriptional activity without affecting both HIF-1? protein accumulation and HIF-1?/HIF-1? heterodimerization in nuclei under the hypoxic conditions, suggesting that 2l probably affected the transcriptional pathway induced by the HIF-1?/HIF-1? heterodimer. PMID:24900662

2013-01-01

166

Further studies of auxin and ACC induced feminization in the cucumber plant using ethylene inhibitors  

NASA Technical Reports Server (NTRS)

The present study was designed to establish the role of an essential hormone controlling sex expression in cucumber. A potent anti-ethylene agent, AgNO3, completely inhibited pistillate flower formation caused by IAA, ACC or ethephon. Inhibitors of ethylene biosynthesis, AVG and CoCl2 also suppressed feminization due to exogenous IAA or ACC. Though AVG also suppressed ethephon-induced feminization, this may be due to the second effect of AVG rather than the effect on ACC biosynthesis. These results confirm that ethylene is a major factor regulating feminization and that exogenous auxin induces pistillate flower formation through its stimulation of ethylene production, rather than ACC production.

Takahashi, H.; Jaffe, M. J.

1984-01-01

167

Effects of inhibitors on 1-methyladenine induced maturation of starfish oocytes  

NASA Astrophysics Data System (ADS)

1-methladenine (1-MA) induces starfish oocytes maturation via surface reaction followed by the appearance of a cytoplasmic maturation factor which in turn induces germinal vesicle breakdown (GVBD) to resume meiosis. Cellular mechanisms involved in GVBD were investigated by microinjection of metabolic inhibitors. Colchicine (Co) inhibited maturation, cytochalasin-B (CB) delayed GVBD and actinomycin-D-(Act-D) and puromycin (Pu) had no effect. It appears that the microtubule and the microfilament systems are associated with the nuclear membrane dissolution during the process of oocyte maturation of starfish.

Lee, Harold H.; Xu, Quanhan

1986-12-01

168

A Novel Sphingosine Kinase Inhibitor Induces Autophagy in Tumor CellsS?  

PubMed Central

The sphingolipids ceramide, sphingosine, and sphingosine 1-phosphate (S1P) regulate cell signaling, proliferation, apoptosis, and autophagy. Sphingosine kinase-1 and -2 (SK1 and SK2) phosphorylate sphingosine to form S1P, shifting the balanced activity of these lipids toward cell proliferation. We have previously reported that pharmacological inhibition of SK activity delays tumor growth in vivo. The present studies demonstrate that the SK2-selective inhibitor 3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide (ABC294640) induces nonapoptotic cell death that is preceded by microtubule-associated protein light chain 3 cleavage, morphological changes in lysosomes, formation of autophagosomes, and increases in acidic vesicles in A-498 kidney carcinoma cells. ABC294640 caused similar autophagic responses in PC-3 prostate and MDA-MB-231 breast adenocarcinoma cells. Simultaneous exposure of A-498 cells to ABC294640 and 3-methyladenine, an inhibitor of autophagy, switched the mechanism of toxicity to apoptosis, but decreased the potency of the SK2 inhibitor, indicating that autophagy is a major mechanism for tumor cell killing by this compound. Induction of the unfolded protein response by the proteasome inhibitor N-(benzyloxycarbonyl)leucinylleucinylleucinal Z-Leu-Leu-Leu-al (MG-132) or the heat shock protein 90 inhibitor geldanamycin synergistically increased the cytotoxicity of ABC294640 in vitro. In severe combined immunodeficient mice bearing A-498 xenografts, daily administration of ABC294640 delayed tumor growth and elevated autophagy markers, but did not increase terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-positive cells in the tumors. These data suggest that ABC294640 promotes tumor cell autophagy, which ultimately results in nonapoptotic cell death and a delay of tumor growth in vivo. Consequently, ABC294640 may effectively complement anticancer drugs that induce tumor cell apoptosis. PMID:20179157

Beljanski, Vladimir; Knaak, Christian

2010-01-01

169

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDS and Cox 2 inhibitors  

Microsoft Academic Search

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form.

C. J. Grossman; J. Wiseman; F. S. Lucas; M. A. Trevethick; P. J. Birch

1995-01-01

170

PUMA mediates EGFR tyrosine kinase inhibitor-induced apoptosis in head and neck cancer cells  

PubMed Central

Overexpression of epidermal growth factor receptor (EGFR) is found in over 80% of head and neck squamous cell carcinomas (HNSCC) and associated with poor clinical outcomes. EFGR selective tyrosine kinase inhibitors (TKIs) or antibodies have recently emerged as promising treatments for solid tumors, including HNSCC, though the response rate to these agents is low. p53 upregulated modulator of apoptosis (PUMA), a BH3-only Bcl-2 family protein, is required for apoptosis induced by p53 and various chemotherapeutic agents. In this study, we show that PUMA induction is correlated with EGFR-TKI sensitivity, and is mediated through the p53 family protein p73? and inhibition of the PI3K/AKT pathway. In some HNSCC cells, the gefitinib-induced degradation of oncogenic ?Np63 seems to facilitate p73-mediated PUMA transcription. Inhibiting PUMA expression by small hairpin RNA (shRNA) impairs gefitinib-induced apoptosis. Furthermore, PUMA or BH3 mimetics sensitize HNSCC cells to gefitinib-induced apoptosis. Our results suggest that PUMA induction through p73 represents a new mechanism of EGFR inhibitor-induced apoptosis, and provide potential ways for enhancing and predicting the sensitivity to EGFR-targeted therapies in HNSCC. PMID:19421143

Sun, Q; Ming, L; Thomas, SM; Wang, Y; Chen, ZG; Ferris, RL; Grandis, JR; Zhang, L; Yu, J

2010-01-01

171

Neuroprotective effects of peroxisome proliferator-activated receptor alpha and gamma agonists in model of parkinsonism induced by intranigral 1-methyl-4-phenyl-1,2,3,6-tetrahyropyridine.  

PubMed

A large body of evidence suggests that peroxisome proliferator-activated receptor (PPAR) agonists may improve some of the pathological features of Parkinson's disease (PD). In the present study, we evaluated the effects of the PPAR-? agonist fenofibrate (100mg/kg) and PPAR-? agonist pioglitazone (30mg/kg) in a rat model of parkinsonism induced by intranigral 1-methyl-4-phenyl-1,2,3,6-tetrahyropyridine (MPTP). Male Wistar rats were pretreated with both drugs for 5 days and received an infusion of MPTP. The experiments were divided into two parts. First, 1, 7, 14, and 21 days after surgery, the animals were submitted to the open field test. On days 21 and 22, the rats were subjected to the forced swim test and two-way active avoidance task. In the second part of the study, 24h after neurotoxin administration, immunohistochemistry was performed to assess tyrosine hydroxylase activity. The levels of dopamine and its metabolites in the striatum were determined using high-performance liquid chromatography, and fluorescence detection was used to assess caspase-3 activation in the substantia nigra pars compacta (SNpc). Both fenofibrate as pioglitazone protected against hypolocomotion, depressive-like behavior, impairment of learning and memory, and dopaminergic neurodegeneration caused by MPTP, with dopaminergic neuron loss of approximately 33%. Fenofibrate and pioglitazone also protected against the increased activation of caspase-3, an effector enzyme of the apoptosis cascade that is considered one of the pathological features of PD. Thus, PPAR agonists may contribute to therapeutic strategies in PD. PMID:25127682

Barbiero, Janaína K; Santiago, Ronise M; Persike, Daniele Suzete; da Silva Fernandes, Maria José; Tonin, Fernanda S; da Cunha, Claudio; Lucio Boschen, Suelen; Lima, Marcelo M S; Vital, Maria A B F

2014-11-01

172

The role of peroxisomal fatty acyl-CoA beta-oxidation in bile acid biosynthesis  

SciTech Connect

The physiological role of the peroxisomal fatty acyl-CoA beta-oxidizing system (FAOS) is not yet established. We speculated that there might be a relationship between peroxisomal degradation of long-chain fatty acids in the liver and the biosynthesis of bile acids. This was investigated using (1-{sup 14}C)butyric acid and (1-{sup 14}C)lignoceric acid as substrates of FAOS in mitochondria and peroxisomes, respectively. The incorporation of ({sup 14}C)lignoceric acid into primary bile acids was approximately four times higher than that of ({sup 14}C)butyric acid (in terms of C-2 units). The pools of these two fatty acids in the liver were exceedingly small. The incorporations of radioactivity into the primary bile acids were strongly inhibited by administration of aminotriazole, which is a specific inhibitor of peroxisomal FAOS in vivo. Aminotriazole inhibited preferentially the formation of cholate, the major primary bile acid, from both ({sup 14}C)lignoceric acid and ({sup 14}C)butyric acid, rather than the formation of chenodeoxycholate. The former inhibition was about 70% and the latter was approximately 40-50%. In view of reports that cholate is biosynthesized from endogenous cholesterol, the above results indicate that peroxisomal FAOS may have an anabolic function, supplying acetyl CoA for bile acid biosynthesis.

Hayashi, H.; Miwa, A. (Josai Univ., Saitama (Japan))

1989-11-01

173

A new matrix metalloproteinase inhibitor SI27 induces apoptosis in several human myeloid leukemia cell lines and enhances sensitivity to TNF alpha-induced apoptosis  

Microsoft Academic Search

MMP inhibitors are used clinically for the stabilization of tumor growth, thus prolonging survival in cancer patients. However, their role in the treatment of hematopoietic malignancies remains unclear. In the present study, we investigated the effects of a new MMP inhibitor, SI-27, in hematopoietic malignancies. SI-27 alone induces apoptosis in several human myeloid leukemia cell lines such as U937, NB4,

Y Nakamura; K Sato; N Wakimoto; F Kimura; A Okuyama; K Motoyoshi

2001-01-01

174

Oppositional Regulation of Noxa by JNK1 and JNK2 during Apoptosis Induced by Proteasomal Inhibitors  

PubMed Central

Proteasome inhibitors (PIs) potently induce apoptosis in a variety of tumor cells, but the underlying mechanisms are not fully elucidated. Comparing PI-induced apoptosis susceptibilities of various mouse embryonic fibroblast (MEF) lines differing in their c-jun N-terminal kinase (JNK) 1 and 2 status, we show that several hallmarks of apoptosis were most rapidly detectable in JNK2?/? cells, whereas they appeared only delayed and severely reduced in their intensities in cells expressing JNK2. Consistent with our finding that PI-induced apoptosis requires de novo protein synthesis, the proteasomal inhibitor MG-132 induced expression of the BH3-only protein Noxa at the transcriptional level in a JNK1-dependent, but JNK2-opposing manner. As the knockdown of Noxa blocked only the rapid PI-induced apoptosis of JNK2?/? cells, but not the delayed death occurring in JNK1?/? and JNK1+/+ cells, our data uncover a novel PI-induced apoptosis pathway that is regulated by the JNK1/2-dependent expression of Noxa. Furthermore, several transcription factors known to modulate Noxa expression including ATF3, ATF4, c-Jun, c-Myc, HIF1?, and p53 were found upregulated following MG-132 exposure. From those, only knockdown of c-Myc rescued JNK2?/? cells from PI-induced apoptosis, however, without affecting expression of Noxa. Together, our data not only show that a rapid execution of PI-induced apoptosis requires JNK1 for upregulation of Noxa via an as yet unknown transcription factor, but also that JNK2 controls this event in an oppositional manner. PMID:23593480

Pietkiewicz, Sabine; Sohn, Dennis; Piekorz, Roland P.; Grether-Beck, Susanne; Budach, Wilfried; Sabapathy, Kanaga; Jänicke, Reiner U.

2013-01-01

175

Protection from impulse noise-induced hearing loss with novel Src-protein tyrosine kinase inhibitors  

PubMed Central

Apoptosis is a significant mechanism of cochlear hair cell loss from noise. Molecules that inhibit apoptotic intracellular signaling reduce cochlear damage and hearing loss from noise. The current study is an extension of a previous study of the protective value of Src-protein tyrosine kinase inhibitors against noise (Harris et al., 2005). The current study tested three Src-inhibitors: the indole-based KX1-141, the biaryl-based KX2-329, and the ATP-competitive KX2-328. Each of the three drugs was delivered into the chinchillas’ cochleae by allowing the solutions to diffuse across the round window membrane thirty minutes prior to exposure to impulse noise. Hearing thresholds were measured using auditory evoked responses from electrodes in the inferior colliculi. Ears treated with KX2-329 showed significantly lower threshold shifts and outer hair cell losses than the control group. The cochleae treated with KX1-141 and KX2-328 did not show statistically significant protection from the impulse noise. The finding of protection with KX2-329 demonstrates that a biaryl-based Src inhibitor has protective capacity against noise-induced hearing loss that is as good as that demonstrated by KX1-004, a Src inhibitor drug that has been studied extensively as an otoprotectant against noise, and suggests that KX2-329 could be useful for protection against noise. PMID:21840347

Bielefeld, Eric C.; Hangauer, David; Henderson, Donald

2011-01-01

176

Multiple serum inhibitors of lectin-induced lymphocyte proliferation in nephrotic syndrome.  

PubMed Central

Inhibitory activity on PHA- and Con A-induced lymphocyte proliferation was observed in the serum of 29 patients with nephrotic syndrome (NS); this inhibitory activity was present both in steroid-sensitive nephrotic syndrome (SSNS; 18 patients) and in NS due to other glomerulopathies (11 patients). In order to characterize the inhibitory activity, peripheral blood lymphocytes from normal donors were stimulated with various concentrations of Con A in culture medium supplemented with: (1) 20% SSNS serum, (2) various concentrations (1, 5 and 20%) of either SSNS serum or normal human serum (NHS) and (3) 20% of a serum prepared by mixing different proportions of SSNS and NHS. The results suggest that the inhibitory activity is due to at least two different factors: (a) inhibitor(s) acting competitively with the lectin Con A, and (b) inhibitor(s) neutralized by factor(s) present in NHS. A disturbance in the normal equilibrium between inhibiting and enhancing factors which results in overall inhibition might well be a consequence of the marked alteration in serum proteins characteristic of NS. PMID:7307346

Martini, A; Vitiello, M A; Siena, S; Capelli, V; Ugazio, A G

1981-01-01

177

Structure, composition, physical properties, and turnover of proliferated peroxisomes. A study of the trophic effects of Su-13437 on rat liver  

PubMed Central

Peroxisome proliferation has been induced with 2-methyl-2-(p-[1,2,3,4-tetrahydro-1-naphthyl]-phenoxy)-propionic acid (Su-13437). DNA, protein, cytochrome oxidase, glucose-6-phosphatase, and acid phosphatase concentrations remain almost constant. Peroxisomal enzyme activities change to approximately 165%, 50%, 30%, and 0% of the controls for catalase, urate oxidase, L-alpha-hydroxy acid oxidase, and D-amino acid oxidase, respectively. For catalase the change results from a decrease in particle-bound activity and a fivefold increase in soluble activity. The average diameter of peroxisome sections is 0.58 +/- 0.15 mum in controls and 0.73 +/- 0.25 mum after treatment. Therefore, the measured peroxisomal enzymes are highly diluted in proliferated particles. After tissue fractionation, approximately one-half of the normal peroxisomes and all proliferated peroxisomes show matric extraction with ghost formation, but no change in size. In homogenates submitted to mechanical stress, proliferated peroxisomes do not reveal increased fragility; unexpectedly, Su-13437 stabilizes lysosomes. Our results suggest that matrix extraction and increased soluble enzyme activities result from transmembrane passage of peroxisomal proteins. The changes in concentration of peroxisomal oxidases and soluble catalase after Su-13437 allow the calculation of their half-lives. These are the same as those found for total catalase, in normal and treated rats, after allyl isopropyl acetamide: about 1.3 days, a result compatible with peroxisome degradation by autophagy. A sequential increase in liver RNA concentration, [14C]leucine incorporation into DOC-soluble proteins and into immunoprecipitable catalase, and an increase in liver size and peroxisomal volume per gram liver, characterize the trophic effect of the drug used. In males, Su-13437 is more active than CPIB, another peroxisome proliferation-inducing drug; in females, only Su-13437 is active. PMID:406

Leighton, F.; Coloma, L.; Koenig, C.

1975-01-01

178

Peroxisome Biogenesis Disorders: Biological, Clinical and Pathophysiological Perspectives  

ERIC Educational Resources Information Center

The peroxisome biogenesis disorders (PBD) are a heterogeneous group of autosomal recessive disorders in which peroxisome assembly is impaired, leading to multiple peroxisome enzyme deficiencies, complex developmental sequelae and progressive disabilities. Mammalian peroxisome assembly involves the protein products of 16 "PEX" genes;…

Braverman, Nancy E.; D'Agostino, Maria Daniela; MacLean, Gillian E.

2013-01-01

179

Low levels of Bax inhibitor-1 gene expression increase tunicamycin-induced apoptosis in human neuroblastoma SY5Y cells?  

PubMed Central

A human SH-SY5Y neuroblastoma cell line with a low level of Bax inhibitor-1 expression was established by lentivirus-mediated RNA interference and fluorescence-activated cell sorting. In control SH-SY5Y cells, tunicamycin treatment induced endoplasmic reticulum stress-mediated apoptosis; however, after Bax inhibitor-1 gene knockdown, cell survival rates were significantly decreased and the degree of apoptosis was significantly increased following tunicamycin treatment. In addition, chromatin condensation and apparent apoptotic phenomena, such as marginalization and cytoplasmic vesicles, were observed. Our findings indicate that Bax inhibitor-1 can delay apoptosis induced by endoplasmic reticulum stress.

Wu, Dan; Wang, Peirong; Wang, Shiyao

2012-01-01

180

Covalent and allosteric inhibitors of the ATPase VCP/p97 induce cancer cell death.  

PubMed

VCP (also known as p97 or Cdc48p in yeast) is an AAA(+) ATPase regulating endoplasmic reticulum-associated degradation. After high-throughput screening, we developed compounds that inhibit VCP via different mechanisms, including covalent modification of an active site cysteine and a new allosteric mechanism. Using photoaffinity labeling, structural analysis and mutagenesis, we mapped the binding site of allosteric inhibitors to a region spanning the D1 and D2 domains of adjacent protomers encompassing elements important for nucleotide-state sensing and ATP hydrolysis. These compounds induced an increased affinity for nucleotides. Interference with nucleotide turnover in individual subunits and distortion of interprotomer communication cooperated to impair VCP enzymatic activity. Chemical expansion of this allosteric class identified NMS-873, the most potent and specific VCP inhibitor described to date, which activated the unfolded protein response, interfered with autophagy and induced cancer cell death. The consistent pattern of cancer cell killing by covalent and allosteric inhibitors provided critical validation of VCP as a cancer target. PMID:23892893

Magnaghi, Paola; D'Alessio, Roberto; Valsasina, Barbara; Avanzi, Nilla; Rizzi, Simona; Asa, Daniela; Gasparri, Fabio; Cozzi, Liviana; Cucchi, Ulisse; Orrenius, Christian; Polucci, Paolo; Ballinari, Dario; Perrera, Claudia; Leone, Antonella; Cervi, Giovanni; Casale, Elena; Xiao, Yang; Wong, Chihunt; Anderson, Daniel J; Galvani, Arturo; Donati, Daniele; O'Brien, Tom; Jackson, Peter K; Isacchi, Antonella

2013-09-01

181

XIAP inhibitors induce differentiation and impair clonogenic capacity of acute myeloid leukemia stem cells.  

PubMed

Acute myeloid leukemia (AML) is a neoplasia characterized by the rapid expansion of immature myeloid blasts in the bone marrow, and marked by poor prognosis and frequent relapse. As such, new therapeutic approaches are required for remission induction and prevention of relapse. Due to the higher chemotherapy sensitivity and limited life span of more differentiated AML blasts, differentiation-based therapies are a promising therapeutic approach. Based on public available gene expression profiles, a myeloid-specific differentiation-associated gene expression pattern was defined as the therapeutic target. A XIAP inhibitor (Dequalinium chloride, DQA) was identified in an in silico screening searching for small molecules that induce similar gene expression regulation. Treatment with DQA, similarly to Embelin (another XIAP inhibitor), induced cytotoxicity and differentiation in AML. XIAP inhibition differentially impaired cell viability of the most primitive AML blasts and reduced clonogenic capacity of AML cells, sparing healthy mature blood and hematopoietic stem cells. Taken together, these results suggest that XIAP constitutes a potential target for AML treatment and support the evaluation of XIAP inhibitors in clinical trials. PMID:24952669

Moreno-Martínez, Daniel; Nomdedeu, Meritxell; Lara-Castillo, María Carmen; Etxabe, Amaia; Pratcorona, Marta; Tesi, Niccolò; Díaz-Beyá, Marina; Rozman, María; Montserrat, Emili; Urbano-Ispizua, Alvaro; Esteve, Jordi; Risueño, Ruth M

2014-06-30

182

XIAP inhibitors induce differentiation and impair clonogenic capacity of acute myeloid leukemia stem cells  

PubMed Central

Acute myeloid leukemia (AML) is a neoplasia characterized by the rapid expansion of immature myeloid blasts in the bone marrow, and marked by poor prognosis and frequent relapse. As such, new therapeutic approaches are required for remission induction and prevention of relapse. Due to the higher chemotherapy sensitivity and limited life span of more differentiated AML blasts, differentiation-based therapies are a promising therapeutic approach. Based on public available gene expression profiles, a myeloid-specific differentiation-associated gene expression pattern was defined as the therapeutic target. A XIAP inhibitor (Dequalinium chloride, DQA) was identified in an in silico screening searching for small molecules that induce similar gene expression regulation. Treatment with DQA, similarly to Embelin (another XIAP inhibitor), induced cytotoxicity and differentiation in AML. XIAP inhibition differentially impaired cell viability of the most primitive AML blasts and reduced clonogenic capacity of AML cells, sparing healthy mature blood and hematopoietic stem cells. Taken together, these results suggest that XIAP constitutes a potential target for AML treatment and support the evaluation of XIAP inhibitors in clinical trials. PMID:24952669

Moreno-Martínez, Daniel; Nomdedeu, Meritxell; Lara-Castillo, María Carmen; Etxabe, Amaia; Pratcorona, Marta; Tesi, Niccolò; Díaz-Beyá, Marina; Rozman, María; Montserrat, Emili; Urbano-Ispizua, Álvaro; Esteve, Jordi; Risueño, Ruth M.

2014-01-01

183

Role of autophagy in histone deacetylase inhibitor-induced apoptotic and nonapoptotic cell death  

PubMed Central

Autophagy is a cellular catabolic pathway by which long-lived proteins and damaged organelles are targeted for degradation. Activation of autophagy enhances cellular tolerance to various stresses. Recent studies indicate that a class of anticancer agents, histone deacetylase (HDAC) inhibitors, can induce autophagy. One of the HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA), is currently being used for treating cutaneous T-cell lymphoma and under clinical trials for multiple other cancer types, including glioblastoma. Here, we show that SAHA increases the expression of the autophagic factor LC3, and inhibits the nutrient-sensing kinase mammalian target of rapamycin (mTOR). The inactivation of mTOR results in the dephosphorylation, and thus activation, of the autophagic protein kinase ULK1, which is essential for autophagy activation during SAHA treatment. Furthermore, we show that the inhibition of autophagy by RNAi in glioblastoma cells results in an increase in SAHA-induced apoptosis. Importantly, when apoptosis is pharmacologically blocked, SAHA-induced nonapoptotic cell death can also be potentiated by autophagy inhibition. Overall, our findings indicate that SAHA activates autophagy via inhibiting mTOR and up-regulating LC3 expression; autophagy functions as a prosurvival mechanism to mitigate SAHA-induced apoptotic and nonapoptotic cell death, suggesting that targeting autophagy might improve the therapeutic effects of SAHA. PMID:22493260

Gammoh, Noor; Lam, Du; Puente, Cindy; Ganley, Ian; Marks, Paul A.; Jiang, Xuejun

2012-01-01

184

Detrimental Effect of the Proteasome Inhibitor, Bortezomib in Bacterial Superantigen- and Lipopolysaccharide-induced Systemic Inflammation  

PubMed Central

Bacterial superantigen (BSAg)–induced toxic shock syndrome (TSS) and bacterial lipopolysaccharide (LPS)–induced shock are characterized by severe systemic inflammation. As nuclear factor ?B (NF?B) plays an important role in inflammation and bortezomib, a proteasome inhibitor widely used in cancer chemotherapy, is a potent inhibitor of NF?B activation, we evaluated the therapeutic and prophylactic use of bortezomib in these conditions using murine models. Bortezomib prophylaxis significantly reduced serum levels of many cytokines and chemokines induced by BSAg. However, at 3 hours, serum level of TNF-a, an important cytokine implicated in TSS, was significantly reduced but not abolished. At 6 hours, there was no difference in the serum TNF-a levels between bortezomib treated and untreated mice challenged with staphylococcal enterotoxin B (SEB). Paradoxically, all mice treated with bortezomib either before or after BSAg challenge succumbed to TSS. Neither bortezomib nor BSAg was lethal if given alone. Serum biochemical parameters and histopathological findings suggested acute liver failure as the possible cause of mortality. Liver tissue from SEB-challenged mice treated with bortezomib showed a significant reduction in NF?B activation. Because NF?B-dependent antiapoptotic pathways protect hepatocytes from TNF-?-induced cell death, inhibition of NF?B brought forth by bortezomib in the face of elevated TNF-? levels caused by BSAg or LPS is detrimental. PMID:20372109

Tilahun, Ashenafi Y; Theuer, Jayne E; Patel, Robin; David, Chella S; Rajagopalan, Govindarajan

2010-01-01

185

The Prolyl Hydroxylase Inhibitor Dimethyloxalylglycine Enhances Dentin Sialophoshoprotein Expression through VEGF-Induced Runx2 Stabilization  

PubMed Central

Prolyl hydroxylase (PHD) inhibitors are suggested as therapeutic agents for tissue regeneration based on their ability to induce pro-angiogenic responses. In this study, we examined the effect of the PHD inhibitor dimethyloxalylglycine (DMOG) on odontoblast maturation and sought to determine the underlying mechanism using MDPC-23 odontoblast-like cells. DMOG significantly enhanced matrix mineralization, confirmed by alizarin red staining and by measurement of the calcium content. DMOG dose-dependently increased alkaline phosphatase activity and the expressions of dentin sialophosphoprotein (Dspp) and osteocalcin. To determine the underlying events leading to DMOG-induced Dspp expression, we analyzed the effect of DMOG on Runx2. Knockdown of Runx2 using siRNAs decreased Dspp expression and prevented DMOG-induced Dspp expression. DMOG enhanced the transcriptional activity and level of Runx2 protein but not Runx2 transcript, and this enhancement was linked to the inhibitory effects of DMOG on the degradation of Runx2 protein. The vascular endothelial growth factor (VEGF) siRNAs profoundly decreased the Runx2 protein levels and inhibited the DMOG-increased Runx2 protein. Recombinant VEGF protein treatment significantly and dose-dependently increased the transcriptional activity and level of the Runx2 protein but not Runx2 transcript. Dspp expression was also enhanced by VEGF. Last, we examined the involvement of the Erk mitogen-activated protein kinase and Pin1 pathway in VEGF-enhanced Runx2 because this pathway can regulate the stability and activity of the Runx2 protein. VEGF stimulated Erk activation, and the inhibitors of Erk and Pin1 hampered VEGF-enhanced Runx2 protein. Taken together, the results of this study provide evidence that DMOG can enhance Dspp expression through VEGF-induced stabilization of Runx2 protein, and thus, suggest that DMOG can be used as a therapeutic tool for enhancing odontoblast maturation in dental procedures. PMID:25369078

Rahman, Saeed Ur; Lee, Min-Sun; Baek, Jeong-Hwa; Ryoo, Hyun-Mo; Woo, Kyung Mi

2014-01-01

186

Risk Assessment and Management of Anthracycline and HER2 Receptor Inhibitor-Induced Cardiomyopathy.  

PubMed

With the advent and increased use of chemotherapeutic agents and radiation therapy, cancer survival rates have increased. With increased survival, both acute and chronic cardiotoxic adverse effects have emerged. The growing need for managing the treatment of individuals with chemotherapy-induced cardiotoxicity has led to the formation of cardio-oncology programs throughout the United States. These programs concentrate on many aspects of cardiac disease in the oncology patient. Of these, the cardiotoxic effects (particularly cardiomyopathy) of anthracyclines and HER2 receptor inhibitors are a large focus of cardio-oncology practice. Despite the increasing availability of these programs, no consensus guidelines have been established to provide a framework for treating these patients. This review describes the initial evaluation, risk assessment, and management of individuals receiving anthracycline and HER2 receptor inhibitor therapy for cardiomyopathy. These recommendations are supported by the current literature in this field. PMID:25688890

Jahangir, Eiman; Shah, Sangeeta; Shum, Kelly; Baxter, Caitlin; Fitzpatrick, Jill D; Cole, John; Gilliland, Yvonne; Polin, Nichole M

2015-02-01

187

Acute abdomen due to intestinal angioedema induced by ACE inhibitors: not so rare?  

PubMed

During the last 5 years we identified 7 patients with a history of episodic acute abdominal pain and subobstruction due to intestinal angioedema secondary to the use of Angiotensin Converting Enzyme (ACE) inhibitors. These cases were all diagnosed in one gastroenterology department. This is thereby the largest single centre case series of ACE inhibitor-induced angioedema that has been published until now. Our findings suggest that this syndrome is far more frequent than international literature would let us believe. We also describe one of the first male cases diagnosed with this entity for which there is a significant female predominance. In the presence of an appropriate history and suggestive findings on CT scan, this diagnosis can relatively easily be made if one is sufficiently intent on it. An appropriate diagnosis can save these patients a lot of unnecessary diagnostic procedures and discomfort. PMID:20163043

Dobbels, P; Van Overbeke, L; Vanbeckevoort, D; Hiele, M

2009-01-01

188

Epigenetic Manipulation of a Filamentous Fungus by the Proteasome-Inhibitor Bortezomib Induces the Production of an Additional Secondary Metabolite  

PubMed Central

The use of epigenetic modifiers, such as histone deacetylase inhibitors and DNA methyltransferase inhibitors, has been explored increasingly as a technique to induce the production of additional microbial secondary metabolites. The application of such molecules to microbial cultures has been shown to upregulate otherwise suppressed genes, and in several cases has led to the production of new molecular structures. In this study, the proteasome inhibitor bortezomib was used to induce the production of an additional metabolite from a filamentous fungus (Pleosporales). The induced metabolite was previously isolated from a plant, but the configuration was not assigned until now; in addition, an analogue was isolated from a degraded sample, yielding a new compound. Proteasome inhibitors have not previously been used in this application and offer an additional tool for microbial genome mining. PMID:24955237

VanderMolen, Karen M.; Darveaux, Blaise A.; Chen, Wei-Lun; Swanson, Steven M.; Pearce, Cedric J.; Oberlies, Nicholas H.

2014-01-01

189

Proteasome inhibitor-induced autophagy in PC12 cells overexpressing A53T mutant ?-synuclein  

PubMed Central

The aim of the present study was to examine the effects of proteasome inhibitor (PI)-induced autophagy on PC12 cells overexpressing A53T mutant ?-synuclein (?-syn) by detecting alterations in the levels of microtubule-associated protein 1A/1B light chain (LC3)+ autophagosomes and the lysotracker-positive autolysosomes using immunofluorescence, the expression of LC3-II using western blot analysis and the morphology of PC12 cells using transmission electron microscopy. It was found that the addition of MG132 (500 nmol/l) significantly increased the number of autophagosomes and autolysosomes and upregulated the expression of LC3-II. The autophagy inhibitor 3-methyladenine (3-MA) completely inhibited the autophagy induced by MG132 (500 nmol/l). The autophagy enhancer trehalose significantly increased the number of autophagosomes and autolysosomes and improved the protein level of LC3-II induced by MG132. To examine the effect of PI-induced autophagy on the degradation of A53T mutant ?-syn, the expression of ?-syn was detected by western blot analysis. It was revealed that MG132 increased the expression of A53T ?-syn and trehalose counteracted the increase of A53T ?-syn induced by MG132. Combined inhibition of 3-MA and PI significantly increased the accumulation of A53T ?-syn as compared with treatment using either single agent. In addition, combination of MG132 (500 nmol/l) with trehalose (50 mmol/l) or 3-MA (2 mmol/l) markedly decreased the cell viability as compared with treatment using either single agent individually as demonstrated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. These results suggest that the PI, MG132, could induce autophagy in PC12 cells overexpressing A53T mutant ?-syn and this autophagy could be completely inhibited by 3-MA, indicating that PI-induced autophagy is mediated by the upregulation of the macroautophagy class III PI3K pathway. PI-induced autophagy may act as a compensatory degradation system for degradation of A53T ?-syn when the ubiquitin-proteasome system is impaired. Autophagy activation may directly contribute to the survival of PC12 cells treated with proteasome inhibitors. The present study may assist in illuminating the association between PI and autophagy in the pathogenesis of Parkinson’s disease. PMID:25434876

LAN, DANMEI; WANG, WENZHAO; ZHUANG, JIANHUA; ZHAO, ZHONGXIN

2015-01-01

190

Angiotensin II induces secretion of plasminogen activator inhibitor 1 and a tissue metalloprotease inhibitor-related protein from rat brain astrocytes.  

PubMed

The present study investigates angiotensin (Ang) II effects on secretory protein synthesis in brain astrocytes cultured from neonatal and 21-day-old rats. Ang II-induced changes in the de novo synthesis of [35S]methionine-labeled secretory proteins were visualized using two-dimensional NaDodSO4/PAGE. Astrocytes from 21-day-old rat brain possess specific high-affinity receptors for Ang II. These cells express two Ang II-induced secretory proteins with Mr 55,000 (AISP-55K) and Mr 30,000 (AISP-30K), which were time- and dose-dependent (EC50, 1 nM). [Sar1, Ile8]Ang II (where Sar is sarcosine) inhibited Ang II-induced secretion of AISP-55K but not AISP-30K. N-terminal amino acid sequencing indicates that AISP-55K is identical to rat plasminogen activator inhibitor 1, whereas AISP-30K exhibits 72-81% identity to three closely related proteins: human tissue inhibitor of metalloproteases, a rat phorbol ester-induced protein, and the murine growth-responsive protein 16C8. Immunofluorescent staining with rat plasminogen activator inhibitor 1 antibody was induced in the majority of cells in culture after Ang II treatment of astrocytes from 21-day-old rat brains. Absence of this response to Ang II in astrocytes from neonatal rat brain provides evidence that this action of Ang II on astrocytes is developmentally regulated. PMID:2000398

Olson, J A; Shiverick, K T; Ogilvie, S; Buhi, W C; Raizada, M K

1991-03-01

191

p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells  

SciTech Connect

Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ? Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ? Compound C can upregulate p53 expression and induce p53 activation. ? Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ? p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ? Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

Huang, Shi-Wei [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Wu, Chun-Ying [Division of Gastroenterology and Hepatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Wang, Yen-Ting [Department of Medical Research and Education, Cheng Hsin General Hospital, Taipei, Taiwan (China); Kao, Jun-Kai [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Pediatrics, Children's Hospital, Changhua Christian Hospital, Changhua, Taiwan (China); Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chiu, Husan-Wen [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chang, Chuan-Hsun [Department of Surgical Oncology, Cheng Hsin General Hospital, Taipei, Taiwan (China); Department of Nutrition Therapy, Cheng Hsin General Hospital, Taipei, Taiwan (China); School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan (China); Liang, Shu-Mei [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chen, Yi-Ju [Department of Dermatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Huang, Jau-Ling [Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan (China); Shieh, Jeng-Jer, E-mail: shiehjj@vghtc.gov.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan (China)

2013-02-15

192

Chronic activation of peroxisome proliferator-activated receptor-alpha with fenofibrate prevents alterations in cardiac metabolic phenotype without changing the onset of decompensation in pacing-induced heart failure  

Technology Transfer Automated Retrieval System (TEKTRAN)

Severe heart failure (HF) is characterized by profound alterations in cardiac metabolic phenotype, with down-regulation of the free fatty acid (FFA) oxidative pathway and marked increase in glucose oxidation. We tested whether fenofibrate, a pharmacological agonist of peroxisome proliferator-activat...

193

A new proteasome inhibitor, TP-110, induces apoptosis in human prostate cancer PC-3 cells.  

PubMed

Proteasome inhibitors are useful in the treatment of cancer. Recently, we found a new proteasome inhibitor, TP-110, derived from tyropeptin A produced by Kitasatospora sp. Here we report that TP-110 induces apoptosis in human prostate cancer PC-3 cells. TP-110 showed strong cytotoxicity to PC-3 cells (IC(50)=0.05 muM). It increased the number of cells in the G(2)-M phase and increased the accumulated amounts of the p21 and p27 proteins, which are negative regulators of cell cycle progression. Furthermore, it induced apoptosis along with chromatin condensation and DNA fragmentation in PC-3 cells, and TP-110-induced apoptosis appeared to be associated with caspase activation. Additionally, TP-110 inhibited not only the degradation of IkappaB and the nuclear translocation of nuclear factor-kappaB (NF-kappaB), but also the DNA binding activity of NF-kappaB. These results indicate that TP-110 shows a strong growth inhibition and apoptosis in PC-3 cells. PMID:17420589

Momose, Isao; Iijima, Masatomi; Kawada, Manabu; Ikeda, Daishiro

2007-04-01

194

Nitric Oxide Synthase Inhibitor Improves De Novo and Long-Term l-DOPA-Induced Dyskinesia in Hemiparkinsonian Rats  

PubMed Central

Inhibitors of neuronal and endothelial nitric oxide synthase decrease l-3,4-dihidroxifenilalanine (l-DOPA)-induced dyskinesias in rodents. The mechanism of nitric oxide inhibitor action is unknown. The aims of the present study were to investigate the decrease of l-DOPA-induced abnormal involuntary movements (AIMs) in 6-hydroxydopamine (6-OHDA)-lesioned rats by nitric oxide inhibitors following either acute or chronic treatment. The primary findings of this study were that NG-nitro-l-Arginine, an inhibitor of endothelial and neuronal nitric oxide synthase, attenuated AIMs induced by chronic and acute l-DOPA. In contrast, rotational behavior was attenuated only after chronic l-DOPA. The 6-OHDA lesion and the l-DOPA treatment induced a bilateral increase (1.5 times) in the neuronal nitric oxide synthase (nNOS) protein and nNOS mRNA in the striatum and in the frontal cortex. There was a parallel increase, bilaterally, of the FosB/?FosB, primarily in the ipsilateral striatum. The exception was in the contralateral striatum and the ipsilateral frontal cortex, where chronic l-DOPA treatment induced an increase of approximately 10 times the nNOS mRNA. Our results provided further evidence of an anti-dyskinetic effect of NOS inhibitor. The effect appeared under l-DOPA acute and chronic treatment. The l-DOPA treatment also revealed an over-expression of the neuronal NOS in the frontal cortex and striatum. Our results corroborated findings that l-DOPA-induced rotation differs between acute and chronic treatment. The effect of the NOS inhibitor conceivably relied on the l-DOPA structural modifications in the Parkinsonian brain. Taken together, these data provided a rationale for further evaluation of NOS inhibitors in the treatment of l-DOPA-induced dyskinesia. PMID:21713068

Padovan-Neto, Fernando Eduardo; Echeverry, Marcela Bermúdez; Chiavegatto, Silvana; Del-Bel, Elaine

2011-01-01

195

Original Contribution Sustained formation of ?-(4-pyridyl-1-oxide)-N-tert-butylnitrone radical adducts in mouse liver by peroxisome proliferators is dependent upon peroxisome proliferator-activated receptor-?, but not NADPH oxidase  

Microsoft Academic Search

Reactive oxygen species are thought to be crucial for peroxisome proliferator-induced liver carcinogenesis. Free radicals have been shown to mediate the production of mitogenic cytokines by Kupffer cells and cause DNA damage in rodent liver. Previous in vivo experiments demonstrated that acute administration of the peroxisome proliferator di(2-ethylhexyl) phthalate (DEHP) led to an increase in production of ?-(4-pyridyl-1-oxide)- N-tert-butylnitrone (POBN)

Courtney G. Woods; Amanda M. Burns; Akira Maki; Blair U. Bradford; Michael L. Cunningham; Henry D. Connor; Maria B. Kadiiska; Ronald P. Mason; Jeffrey M. Peters; Ivan Rusyn

196

Conformational Changes in HIV-1 Reverse Transcriptase Induced by Nonnucleoside Reverse Transcriptase Inhibitor Binding  

PubMed Central

Nonnucleoside reverse transcriptase inhibitors (NNRTI) are a group of small hydrophobic compounds with diverse structures that specifically inhibit HIV-1 reverse transcriptase (RT). NNRTIs interact with HIV-1 RT by binding to a single site on the p66 subunit of the p66/p51 heterodimeric enzyme, termed the NNRTI-binding pocket (NNRTI-BP). This binding interaction results in both short-range and long-range distortions of RT structure. In this article, we review the structural, computational and experimental evidence of the NNRTI-induced conformational changes in HIV-1 RT and relate them to the mechanism by which these compounds inhibit HIV-1 reverse transcription. PMID:15544453

Sluis-Cremer, Nicolas; Temiz, N. Alpay; Bahar, Ivet

2005-01-01

197

The Natural Product Noformycin Is an Inhibitor of Inducible-Nitric Oxide Synthase  

Microsoft Academic Search

Inducible-Nitric oxide synthase (iNOS, EC 1.14.13.39) catalyzes the formation of nitric oxide (NO) andL-citrulline fromL-Arg, NADPH and dioxygen. The natural product, (?)-noformycin was found to be a potent, competitive inhibitor of recombinant human iNOS with respect toL-Arg with aKi= 1.3 ± 0.3 ?M. The reversible binding of noformycin caused a high spin type I spectral perturbation of the iNOS heme

Barbara Gordon Green; Renee Chabin; Stephan K. Grant

1996-01-01

198

ACE inhibitor-induced angioedema of the small intestine: a case report.  

PubMed

Angiotensin-converting enzyme (ACE) inhibitors are standard medication in treating hypertension, heart failure and diabetic nephropathy. The most common side effects are cough and angioneurotic oedema of the upper airways. A less familiar side effect is the ACE inhibition-induced visceral angioedema. We report the case of a young female patient with recent diagnosis of heart failure (dilated cardiomyopathy due to viral myocarditis), who developed angioedema of the small intestine three weeks after initiating treatment with lisinopril. Symptoms resolved within days once administration of the drug was stopped. PMID:22032061

Cuypers, Sofie; Van Meerbeeck, Stephen; De Pauw, Michel

2011-10-01

199

Anmindenols A and B, inducible nitric oxide synthase inhibitors from a marine-derived Streptomyces sp.  

PubMed

Anmindenols A (1) and B (2), inhibitors of inducible nitric oxide synthase (iNOS), were isolated from a marine-derived bacterium Streptomyces sp. Their chemical structures were elucidated by interpreting various spectroscopic data, including IR, MS, and NMR. Anmindenols A and B are sesquiterpenoids possessing an indene moiety with five- and six-membered rings derived from isoprenyl units. The absolute configuration of C-4 in anmindenol B was determined by electronic circular dichroism (ECD) of a dimolybdenum complex. Anmindenols A (1) and B (2) inhibited nitric oxide production in stimulated RAW 264.7 macrophage cells with IC50 values of 23 and 19 ?M, respectively. PMID:24878306

Lee, Jihye; Kim, Hiyoung; Lee, Tae Gu; Yang, Inho; Won, Dong Hwan; Choi, Hyukjae; Nam, Sang-Jip; Kang, Heonjoong

2014-06-27

200

Histone deacetylase inhibitor treatment induces ‘BRCAness’ and synergistic lethality with PARP inhibitor and cisplatin against human triple negative breast cancer cells  

PubMed Central

There is an unmet need to develop new, more effective and safe therapies for the aggressive forms of triple negative breast cancers (TNBCs). While up to 20% of women under 50 years of age with TNBC harbor germline mutations in BRCA1, and these tumors are sensitive to treatment with poly(ADP) ribose polymerase inhibitors, a majority of TNBCs lack BRCA1 mutations or loss of expression. Findings presented here demonstrate that by attenuating the levels of DNA damage response and homologous recombination proteins, pan-histone deacetylase inhibitor (HDI) treatment induces ‘BRCAness’ and sensitizes TNBC cells lacking BRCA1 to lethal effects of PARP inhibitor or cisplatin. Treatment with HDI also induced hyperacetylation of nuclear hsp90. Similar effects were observed following shRNA-mediated depletion of HDAC3, confirming its role as the deacetylase for nuclear HSP90. Furthermore, cotreatment with HDI and ABT-888 induced significantly more DNA strand breaks than either agent alone, and synergistically induced apoptosis of TNBC cells. Notably, co-treatment with HDI and ABT-888 significantly reduced in vivo tumor growth and markedly improved the survival of mice bearing TNBC cell xenografts. These findings support the rationale to interrogate the clinical activity of this novel combination against human TNBC, irrespective of its expression of mutant BRCA1. PMID:25026298

Ha, Kyungsoo; Bhaskara, Srividya; Cerchietti, Leandro; Devaraj, Santhana G. T.; Shah, Bhavin; Sharma, Sunil; Chang, Jenny C.; Melnick, Ari M.; Hiebert, Scott; Bhalla, Kapil N.

2014-01-01

201

Cytoprotective effect of selective small-molecule caspase inhibitors against staurosporine-induced apoptosis  

PubMed Central

Caspases are currently known as the central executioners of the apoptotic pathways. Inhibition of apoptosis and promotion of normal cell survival by caspase inhibitors would be a tremendous benefit for reducing the side effects of cancer therapy and for control of neurodegenerative disorders such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. The objective of this study was to discover small-molecule caspase inhibitors with which to achieve cytoprotective effect. We completed the high-throughput screening of Bionet’s 37,500-compound library (Key Organics Limited, Camelford, Cornwall, UK) against caspase-1, -3, and -9 and successfully identified 43 initial hit compounds. The 43 hit compounds were further tested for cytoprotective activity against staurosporine-induced cell death in NIH3T3 cells. Nineteen compounds were found to have significant cytoprotective effects in cell viability assays. One of the compounds, RBC1023, was demonstrated to protect NIH3T3 cells from staurosporine-induced caspase-3 cleavage and activation. RBC1023 was also shown to protect against staurosporine-induced impairment of mitochondrial membrane potential. DNA microarray analysis demonstrated that staurosporine treatment induced broad global gene expression alterations, and RBC1023 co-treatment significantly restored these changes, especially of the genes that are related to cell growth and survival signaling such as Egr1, Cdc25c, cdkn3, Rhob, Nek2, and Taok1. Collectively, RBC1023 protects NIH3T3 cells against staurosporine-induced apoptosis via inhibiting caspase activity, restoring mitochondrial membrane potential, and possibly upregulating some cell survival-related gene expressions and pathways. PMID:24920883

Wu, Jianghong; Wang, Yuren; Liang, Shuguang; Ma, Haiching

2014-01-01

202

Topically Applied Hsp90 Inhibitor 17AAG Inhibits UVR-Induced Cutaneous Squamous Cell Carcinomas.  

PubMed

We present here that heat-shock protein 90 (Hsp90) inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17AAG), when topically applied to mouse skin, inhibits UVR-induced development of cutaneous squamous cell carcinoma (SCC). In these experiments, DMSO:acetone (1:40 v/v) solution of 17AAG (500?nmol) was applied topically to mouse skin in conjunction with each UVR exposure (1.8?kJ?m(-2)). The UVR source was Kodacel-filtered FS-40 sun lamps (approximately 60% UVB and 40% UVA). In independent experiments with three separate mouse lines (SKH-1 hairless mice, wild-type FVB, and protein kinase C epsilon (PKC?)-overexpressing transgenic FVB mice), 17AAG treatment increased the latency and decreased both the incidence and multiplicity of UVR-induced SCC. Topical 17AAG alone or in conjunction with UVR treatments elicited neither skin nor systemic toxicity. 17AAG-caused inhibition of SCC induction was accompanied by a decrease in UVR-induced (1) hyperplasia, (2) Hsp90?-PKC? interaction, and (3) expression levels of Hsp90?, Stat3, pStat3Ser727, pStat3Tyr705, pAktSer473, and matrix metalloproteinase (MMP). The results presented here indicate that topical Hsp90 inhibitor 17AAG is effective in prevention of UVR-induced epidermal hyperplasia and SCC. One may conclude from the preclinical data presented here that topical 17AAG may be useful for prevention of UVR-induced inflammation and cutaneous SCC either developed in UVR-exposed or organ transplant population.Journal of Investigative Dermatology advance online publication, 20 November 2014; doi:10.1038/jid.2014.460. PMID:25337691

Singh, Anupama; Singh, Ashok; Sand, Jordan M; Bauer, Samuel J; Bin Hafeez, Bilal; Meske, Louise; Verma, Ajit K

2014-10-22

203

A TSC signaling node at the peroxisome regulates mTORC1 and autophagy in response to ROS  

PubMed Central

Subcellular localization is emerging as an important mechanism for mTORC1 regulation. We report that the tuberous sclerosis complex (TSC) signaling node, TSC1, TSC2 and Rheb, localizes to peroxisomes, where it regulates mTORC1 in response to reactive oxygen species (ROS). TSC1 and TSC2 were bound by PEX19 and PEX5, respectively, and peroxisome-localized TSC functioned as a Rheb GAP to suppress mTORC1 and induce autophagy. Naturally occurring pathogenic mutations in TSC2 decreased PEX5 binding, abrogated peroxisome localization, Rheb GAP activity, and suppression of mTORC1 by ROS. Cells lacking peroxisomes were deficient in mTORC1 repression by ROS and peroxisome-localization deficient TSC2 mutants caused polarity defects and formation of multiple axons in neurons. These data identify a role for TSC in responding to ROS at the peroxisome, and identify the peroxisome as a signaling organelle involved in regulation of mTORC1. PMID:23955302

Zhang, Jiangwei; Kim, Jinhee; Alexander, Angela; Cai, Shengli; Tripathi, Durga Nand; Dere, Ruhee; Tee, Andrew R.; Tait-Mulder, Jacqueline; Di Nardo, Alessia; Han, Juliette M.; Kwiatkowski, Erica; Dunlop, Elaine A.; Dodd, Kayleigh M.; Folkerth, Rebecca D.; Faust, Phyllis L.; Kastan, Michael B.; Sahin, Mustafa; Walker, Cheryl Lyn

2013-01-01

204

A small molecule inhibitor of XIAP induces apoptosis and synergises with vinorelbine and cisplatin in NSCLC  

PubMed Central

Background: Evasion of apoptosis contributes to the pathogenesis of solid tumours including non-small cell lung cancer (NSCLC). Malignant cells resist apoptosis through over-expression of inhibitor of apoptosis proteins (IAPs), such as X-linked IAP (XIAP). Methods: A phenylurea-based small molecule inhibitor of XIAP, XIAP antagonist compound (XAC) 1396-11, was investigated preclincally to determine its ability to sensitise to clinically relevant cytotoxics, potentially allowing dose reduction while maintaining therapeutic efficacy. Results: XIAP protein expression was detected in six NSCLC cell lines examined. The cytotoxicity of XAC 1396-11 against cultured NSCLC cell lines in vitro was concentration- and time-dependent in both short-term and clonogenic assays. XAC 1396-11-induced apoptosis was confirmed by PARP cleavage and characteristic nuclear morphology. XAC 1396-11 synergised with vinorelbine±cisplatin in H460 and A549 NSCLC cells. The mechanism of synergy was enhanced apoptosis, shown by increased cleavage of caspase-3 and PARP and by the reversal of synergy by a pan-caspase inhibitor. Synergy between XAC 1396-11 and vinorelbine was augmented by optimising drug scheduling with superior effects when XAC 1396-11 was administered before vinorelbine. Conclusion: These preclinical data suggest that XIAP inhibition in combination with vinorelbine holds potential as a therapeutic strategy in NSCLC. PMID:19904270

Dean, E J; Ward, T; Pinilla, C; Houghten, R; Welsh, K; Makin, G; Ranson, M; Dive, C

2009-01-01

205

Mitochondrial and peroxisomal beta-oxidation capacities of organs from a non-oilseed plant.  

PubMed

Until recently, beta-oxidation was believed to be exclusively located in the peroxisomes of all higher plants. Whilst this is true for germinating oilseeds undergoing gluconeogenesis, evidence demonstrating mitochondrial beta-oxidation in other plant systems has refuted this central dogma of plant lipid metabolism. This report describes a comparative study of the dual mitochondrial and peroxisomal beta-oxidation capacities of plant organs. Oxidation of [1-(14)C] palmitate was measured in the cotyledons, plumules and radicles of Pisum sativum L., which is a starchy seed, over a 14 day period from the commencement of imbibition. Respiratory chain inhibitors were used for differentiating between mitochondrial and peroxisomal beta-oxidation. Peroxisomal beta-oxidation gave a steady, baseline rate and, in the early stages of seedling development, accounted for 70-100% of the beta-oxidation observed. Mitochondrial beta-oxidation gave peaks of activity at days 7 and 10-11, accounting for up to 82% of the total beta-oxidation activity at these times. These peaks coincide with key stages of seedling development and were not observed when normal development was disrupted by growth in the dark. Peroxisomal beta-oxidation was unaffected by etiolation. Since mitochondrial beta-oxidation was overt only during times of intense biosynthetic activity it might be switched on or off during seedling development. In contrast, peroxisomes maintained a continuous, low beta-oxidation activity that could be essential in removing harmful free fatty acids, e.g. those produced by protein and lipid turnover. PMID:11564353

Masterson, C; Wood, C

2001-09-22

206

The Cytoskeleton and the Peroxisomal-Targeted SNOWY COTYLEDON3 Protein Are Required for Chloroplast Development in Arabidopsis[W  

PubMed Central

Here, we describe the snowy cotyledon3 (sco3-1) mutation, which impairs chloroplast and etioplast development in Arabidopsis thaliana seedlings. SCO3 is a member of a largely uncharacterized protein family unique to the plant kingdom. The sco3-1 mutation alters chloroplast morphology and development, reduces chlorophyll accumulation, impairs thylakoid formation and photosynthesis in seedlings, and results in photoinhibition under extreme CO2 concentrations in mature leaves. There are no readily apparent changes to chloroplast biology, such as transcription or assembly that explain the disruption to chloroplast biogenesis. Indeed, SCO3 is actually targeted to another organelle, specifically to the periphery of peroxisomes. However, impaired chloroplast development cannot be attributed to perturbed peroxisomal metabolic processes involving germination, fatty acid ?-oxidation or photorespiration, though there are so far undescribed changes in low and high CO2 sensitivity in seedlings and young true leaves. Many of the chloroplasts are bilobed, and some have persistent membranous extensions that encircle other cellular components. Significantly, there are changes to the cytoskeleton in sco3-1, and microtubule inhibitors have similar effects on chloroplast biogenesis as sco3-1 does. The localization of SCO3 to the periphery of the peroxisomes was shown to be dependent on a functional microtubule cytoskeleton. Therefore, the microtubule and peroxisome-associated SCO3 protein is required for chloroplast development, and sco3-1, along with microtubule inhibitors, demonstrates an unexpected role for the cytoskeleton and peroxisomes in chloroplast biogenesis. PMID:20978221

Albrecht, Verónica; Šimková, Klára; Carrie, Chris; Delannoy, Etienne; Giraud, Estelle; Whelan, Jim; Small, Ian David; Apel, Klaus; Badger, Murray R.; Pogson, Barry James

2010-01-01

207

Inhibitor-induced Conformational Shifts and Ligand Exchange Dynamics for HIV-1 Protease Measured by Pulsed EPR and NMR Spectroscopy  

PubMed Central

Double electron-electron resonance (DEER) spectroscopy was utilized to investigate shifts in conformational sampling induced by nine FDA-approved protease inhibitors (PIs) and a non-hydrolyzable substrate mimic for human immunodeficiency virus type 1 protease (HIV-1 PR) subtype B, subtype C and CRF_01 A/E. The ligand-bound subtype C protease has broader DEER distance profiles but trends for inhibitor-induced conformational shifts are comparable to those previously reported for subtype B. Ritonavir, one of the strong-binding inhibitors for subtype B and C, induces less of the closed conformation in CRF_01 A/E. 1H-15N heteronuclear single quantum coherence (HSQC) spectra were acquired for each protease construct titrated with the same set of inhibitors. NMR 1H-15N HSQC titration data show that inhibitor residence time in the protein binding pocket, inferred from resonance exchange broadening, shifting or splitting correlates with the degree of ligand-induced flap closure measured by DEER spectroscopy. These parallel results show that the ligand-induced conformational shifts resulting from protein-ligand interactions characterized by DEER spectroscopy of HIV-1 PR obtained at cryogenic temperature are consistent with more physiological solution protein-ligand interactions observed via solution NMR. PMID:23167829

Huang, Xi; de Vera, Ian Mitchelle S.; Veloro, Angelo M.; Blackburn, Mandy E.; Kear, Jamie L.; Carter, Jeffery D.; Rocca, James R.; Simmerling, Carlos; Dunn, Ben M.; Fanucci, Gail E.

2013-01-01

208

Induced resistance to methionyl-tRNA synthetase inhibitors in Trypanosoma brucei is due to overexpression of the target.  

PubMed

New classes of antiparasitic drugs active against Trypanosoma brucei are needed to combat human African trypanosomiasis. Inhibitors of methionyl-tRNA synthetase (MetRS) have excellent potential to be developed for this purpose (S. Shibata, J. R. Gillespie, A. M. Kelley, A. J. Napuli, Z. Zhang, K. V. Kovzun, R. M. Pefley, J. Lam, F. H. Zucker, W. C. Van Voorhis, E. A. Merritt, W. G. Hol, C. L. Verlinde, E. Fan, and F. S. Buckner, Antimicrob. Agents Chemother. 55:1982-1989, 2011). In order to assess the potential for resistance to develop against this new class of inhibitors, T. brucei cultures were grown in the presence of MetRS inhibitors or comparison drugs. Resistance up to ?50 times the baseline 50% inhibitory concentration (IC50) was induced against a MetRS inhibitor after ?120 days. A similar level of resistance to the clinical drug eflornithine was induced after ?50 days and for pentamidine after ?80 days. Thus, resistance was induced more slowly against MetRS inhibitors than against clinically used drugs. The parasites resistant to the MetRS inhibitor were shown to overexpress MetRS mRNA by a factor of 35 over the parental strain. Southern analysis indicated that the MetRS gene was amplified in the genome by nearly 8-fold. When injected into mice, the MetRS inhibitor-resistant parasites caused a reduced level of infection, indicating that the changes associated with resistance attenuated their virulence. This finding and the fact that resistance to MetRS inhibitors developed relatively slowly are encouraging for further development of this class of compounds. Published studies on other antitrypanosomal drugs have primarily shown that alterations in membrane transporters were the mechanisms responsible for resistance. This is the first published report of induced drug resistance in the African trypanosome due to overexpression of the target enzyme. PMID:23587950

Ranade, Ranae M; Gillespie, J Robert; Shibata, Sayaka; Verlinde, Christophe L M J; Fan, Erkang; Hol, Wim G J; Buckner, Frederick S

2013-07-01

209

HIF Prolyl Hydroxylase Inhibitors Prevent Neuronal Death Induced by Mitochondrial Toxins: Therapeutic Implications for Huntington's Disease and Alzheimer's Disease  

PubMed Central

Abstract Mitochondrial dysfunction is a central feature of a number of acute and chronic neurodegenerative conditions, but clinically approved therapeutic interventions are only just emerging. Here we demonstrate the potential clinical utility of low molecular weight inhibitors of the hypoxia inducible factor prolyl-4-hydroxylases (HIF PHDs) in preventing mitochondrial toxin-induced cell death in mouse striatal neurons that express a “knock-in” mutant Huntingtin allele. Protection from 3-nitropropionic acid (3-NP, a complex II inhibitor)-induced toxicity by HIF PHD inhibition occurs without rescue of succinate dehydrogenase activity. Although HIF-1? mRNA is dramatically induced by mutant huntingtin, HIF-1? depletion by short interfering RNAs (siRNA) does not affect steady-state viability or protection from 3-NP-induced death by HIF PHD inhibitors in these cells. Moreover, 3-NP-induced complex II inhibition in control or mutant striatal neurons does not lead to activation of HIF-dependent transcription. HIF PHD inhibition also protects cortical neurons from 3-NP-induced cytotoxicity. Protection of cortical neurons by HIF PHD inhibition correlates with enhanced VEGF but not PGC-1? gene expression. Together, these findings suggest that HIF PHD inhibitors are promising candidates for preventing cell death in conditions such as Huntington's disease and Alzheimer's disease that are associated with metabolic stress in the central nervous system. Antioxid. Redox Signal. 12, 435–443. PMID:19659431

Niatsetskaya, Zoya; Basso, Manuela; Speer, Rachel E.; McConoughey, Stephen J.; Coppola, Giovanni; Ma, Thong C.

2010-01-01

210

Apoptosis induced in neuronal cultures by either the phosphatase inhibitor okadaic acid or the kinase inhibitor staurosporine is attenuated by isoquinolinesulfonamides H-7, H-8, and H-9  

Microsoft Academic Search

Protein phosphorylation is kept in balance by an orchestrated action of kinases and phosphatases; when this balance is lost,\\u000a neuronal apoptosis may occur. Okadaic acid (OKA), a marine toxin that inhibits specifically protein phosphatases 1 and 2A\\u000a (EC 3.1.3.16), and staurosporine, an inhibitor of protein kinase C (PKC; EC 2.7.1.37), induced apoptosis in primary cultures\\u000a of rat cerebellar granule neurons.

Cinzia M. Cagnoli; Elena Kharlamov; Cagla Atabay; Tolga Uz; Hari Manev

1996-01-01

211

Antidiabetic effects of SGLT2-selective inhibitor ipragliflozin in streptozotocin-nicotinamide-induced mildly diabetic mice.  

PubMed

Sodium-glucose cotransporter (SGLT) 2 plays an important role in renal glucose reabsorption, and inhibition of renal SGLT2 activity represents an innovative strategy for the treatment of hyperglycemia in diabetic patients. The present study investigated the antidiabetic effects of ipragliflozin, a SGLT2-selective inhibitor, in streptozotocin-nicotinamide-induced mildly diabetic mice, which exhibited a mild decline in glucose tolerance associated with the loss of early-phase insulin secretion. Oral administration of ipragliflozin increased urinary glucose excretion in a dose-dependent manner, an effect which was significant at doses of 0.3 mg/kg or higher and lasted over 12 h. In addition, ipragliflozin dose-dependently improved hyperglycemia and glucose intolerance with concomitant decreases in plasma insulin levels without causing hypoglycemia. Once-daily dosing of ipragliflozin (0.1 - 3 mg/kg) for 4 weeks attenuated hyperglycemia, glucose intolerance, and impaired insulin secretion. These results suggest that the SGLT2-selective inhibitor ipragliflozin increases urinary glucose excretion by inhibiting renal glucose reabsorption, improves hyperglycemia in streptozotocin-nicotinamide-induced mildly diabetic mice, and may be useful for treating type 2 diabetes. PMID:22971845

Tahara, Atsuo; Kurosaki, Eiji; Yokono, Masanori; Yamajuku, Daisuke; Kihara, Rumi; Hayashizaki, Yuka; Takasu, Toshiyuki; Imamura, Masakazu; Qun, Li; Tomiyama, Hiroshi; Kobayashi, Yoshinori; Noda, Atsushi; Sasamata, Masao; Shibasaki, Masayuki

2012-01-01

212

Histone deacetylase inhibitor, butyrate, attenuates lipopolysaccharide-induced acute lung injury in mice  

PubMed Central

Background Histone deacetylase (HDAC) inhibitors, developed as promising anti-tumor drugs, exhibit their anti-inflammatory properties due to their effects on reduction of inflammatory cytokines. Objective To investigate the protective effect of butyrate, a HDAC inhibitor, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Methods ALI was induced in Balb/c mice by intratracheally instillation of LPS (1 mg/kg). Before 1 hour of LPS administration, the mice received butyrate (10 mg/kg) orally. The animals in each group were sacrificed at different time point after LPS administration. Pulmonary histological changes were evaluated by hematoxylin-eosin stain and lung wet/dry weight ratios were observed. Concentrations of interleukin (IL)-1? and tumor necrosis factor (TNF)-? in bronchoalveolar lavage fluid (BALF) and concentrations of nitric oxide (NO) and myeloperoxidase (MPO) activity in lung tissue homogenates were measured by enzyme-linked immunosorbent assay (ELISA). Expression of nuclear factor (NF)-?B p65 in cytoplasm and nucleus was determined by Western blot analysis respectively. Results Pretreatment with butyrate led to significant attenuation of LPS induced evident lung histopathological changes, alveolar hemorrhage, and neutrophils infiltration with evidence of reduced MPO activity. The lung wet/dry weight ratios, as an index of lung edema, were reduced by butyrate administration. Butyrate also repressed the production of TNF-?, IL-1? and NO. Furthermore, the expression of NF-?B p65 in nucleus was markedly suppressed by butyrate pretreatment. Conclusions Butyrate had a protective effect on LPS-induced ALI, which may be related to its effect on suppression of inflammatory cytokines production and NF-?B activation. PMID:20302656

2010-01-01

213

Glycine transporters type 1 inhibitor promotes brain preconditioning against NMDA-induced excitotoxicity.  

PubMed

Brain preconditioning is a protective mechanism, which can be activated by sub-lethal stimulation of the NMDA receptors (NMDAR) and be used to achieve neuroprotection against stroke and neurodegenerative diseases models. Inhibitors of glycine transporters type 1 modulate glutamatergic neurotransmission through NMDAR, suggesting an alternative therapeutic strategy of brain preconditioning. The aim of this work was to evaluate the effects of brain preconditioning induced by NFPS, a GlyT1 inhibitor, against NMDA-induced excitotoxicity in mice hippocampus, as well as to study its neurochemical mechanisms. C57BL/6 mice (male, 10-weeks-old) were preconditioned by intraperitoneal injection of NFPS at doses of 1.25, 2.5 or 5.0 mg/kg, 24 h before intrahippocampal injection of NMDA. Neuronal death was evaluated by fluoro jade C staining and neurochemical parameters were evaluated by gas chromatography-mass spectrometry, scintillation spectrometry and western blot. We observed that NFPS preconditioning reduced neuronal death in CA1 region of hippocampus submitted to NMDA-induced excitotoxicity. The amino acids (glycine and glutamate) uptake and content were increased in hippocampus of animals treated with NFPS 5.0 mg/kg, which were associated to an increased expression of type-2 glycine transporter (GlyT2) and glutamate transporters (EAAT1, EAAT2 and EAAT3). The expression of GlyT1 was reduced in animals treated with NFPS. Interestingly, the preconditioning reduced expression of GluN2B subunits of NMDAR, whereas did not change the expression of GluN1 or GluN2A in all tested doses. Our study suggests that NFPS preconditioning induces resistance against excitotoxicity, which is associated with neurochemical changes and reduction of GluN2B-containing NMDAR expression. PMID:25312280

Cunha Xavier Pinto, Mauro; Lima, Isabel Vieira de Assis; Pessoa da Costa, Flávia Lage; Rosa, Daniela Valadão; Mendes-Goulart, Vânia Aparecida; Resende, Rodrigo Ribeiro; Romano-Silva, Marco Aurélio; Pinheiro de Oliveira, Antônio Carlos; Gomez, Marcus Vinícius; Gomez, Renato Santiago

2015-02-01

214

Effect of the Angiotensin I Converting Enzyme Inhibitor, MK-421, on Experimentally Induced Drinking  

NASA Technical Reports Server (NTRS)

MK-421, the ethyl ester maleate salt of N-(S)-1-(ethoxycarbonyl)-3-phenyl-propyl- Ala-L-Pro, is an angiotensin I converting enzyme inhibitor. An initial objective was to determine whether MK-421, administered at 0, 2.5, 5.0, 10.0, 20.0 and 40.0 mg/kg, ip to 96 female rats 15 min prior to administration of the beta-adrenergic agonist, isoproterenol (25 microgram/kg, ip), would inhibit the drinking induced by isoproterenol during 2 h after its administration. The water intake induced by isoproterenol was inhibited significantly by 2.5 mg MK-421/kg. When a similar experiment was performed using Angiotensin I (AI) (200 microgram/kg, ip) as the dipsogenic agent, MK-421 (5 mg/kg, ip), administered 15 min prior to AI, inhibited significantly both the dipsogenic and the diuretic effect of AI. However, administration of angiotensin II (AII, 200 microgram/kg, ip) 15 min after MK-421 (5mg/kg) was accompanied by a water intake that did not differ from AII alone. The drink induced by ip administration of 1.0 m NaCl solution (1% of body wt, ip) was not inhibited by administration of MK-421 (5 mg/kg) 15 min prior to allowing access to water while the drink induced by a 24 h dehydration was partially inhibited. Thus, the drinks induced by administraition of either isoproterenol or AI are dependent on formation of AII. That induced by dehydration is partially dependent, while that induced by hypertonic siilinc is independent of the formation of AII.

Fregley, Melvin J.; Fater, Dennis C.; Greenleaf, John E.

1982-01-01

215

A rat retinal damage model predicts for potential clinical visual disturbances induced by Hsp90 inhibitors  

SciTech Connect

In human trials certain heat shock protein 90 (Hsp90) inhibitors, including 17-DMAG and NVP-AUY922, have caused visual disorders indicative of retinal dysfunction; others such as 17-AAG and ganetespib have not. To understand these safety profile differences we evaluated histopathological changes and exposure profiles of four Hsp90 inhibitors, with or without clinical reports of adverse ocular effects, using a rat retinal model. Retinal morphology, Hsp70 expression (a surrogate marker of Hsp90 inhibition), apoptotic induction and pharmacokinetic drug exposure analysis were examined in rats treated with the ansamycins 17-DMAG and 17-AAG, or with the second-generation compounds NVP-AUY922 and ganetespib. Both 17-DMAG and NVP-AUY922 induced strong yet restricted retinal Hsp70 up-regulation and promoted marked photoreceptor cell death 24 h after the final dose. In contrast, neither 17-AAG nor ganetespib elicited photoreceptor injury. When the relationship between drug distribution and photoreceptor degeneration was examined, 17-DMAG and NVP-AUY922 showed substantial retinal accumulation, with high retina/plasma (R/P) ratios and slow elimination rates, such that 51% of 17-DMAG and 65% of NVP-AUY922 present at 30 min post-injection were retained in the retina 6 h post-dose. For 17-AAG and ganetespib, retinal elimination was rapid (90% and 70% of drugs eliminated from the retina at 6 h, respectively) which correlated with lower R/P ratios. These findings indicate that prolonged inhibition of Hsp90 activity in the eye results in photoreceptor cell death. Moreover, the results suggest that the retina/plasma exposure ratio and retinal elimination rate profiles of Hsp90 inhibitors, irrespective of their chemical class, may predict for ocular toxicity potential. - Highlights: • In human trials some Hsp90 inhibitors cause visual disorders, others do not. • Prolonged inhibition of Hsp90 in the rat eye results in photoreceptor cell death. • Retina/plasma ratio and retinal elimination rate are linked to toxicity potential. • Rat retinotoxic responses to individual Hsp90 inhibitors reflect clinical profiles. • Rodent modeling may be used to assess ocular risks of targeted Hsp90 compounds.

Zhou, Dan, E-mail: DZhou@syntapharma.com [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Liu, Yuan; Ye, Josephine; Ying, Weiwen; Ogawa, Luisa Shin; Inoue, Takayo; Tatsuta, Noriaki; Wada, Yumiko; Koya, Keizo [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Huang, Qin [Department of Pathology and Laboratory Medicine, Veterans Affairs Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132 (United States); Bates, Richard C.; Sonderfan, Andrew J. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States)

2013-12-01

216

Targeting ER stress–induced autophagy overcomes BRAF inhibitor resistance in melanoma  

PubMed Central

Melanomas that result from mutations in the gene encoding BRAF often become resistant to BRAF inhibition (BRAFi), with multiple mechanisms contributing to resistance. While therapy-induced autophagy promotes resistance to a number of therapies, especially those that target PI3K/mTOR signaling, its role as an adaptive resistance mechanism to BRAFi is not well characterized. Using tumor biopsies from BRAFV600E melanoma patients treated either with BRAFi or with combined BRAF and MEK inhibition, we found that BRAFi-resistant tumors had increased levels of autophagy compared with baseline. Patients with higher levels of therapy-induced autophagy had drastically lower response rates to BRAFi and a shorter duration of progression-free survival. In BRAFV600E melanoma cell lines, BRAFi or BRAF/MEK inhibition induced cytoprotective autophagy, and autophagy inhibition enhanced BRAFi-induced cell death. Shortly after BRAF inhibitor treatment in melanoma cell lines, mutant BRAF bound the ER stress gatekeeper GRP78, which rapidly expanded the ER. Disassociation of GRP78 from the PKR-like ER-kinase (PERK) promoted a PERK-dependent ER stress response that subsequently activated cytoprotective autophagy. Combined BRAF and autophagy inhibition promoted tumor regression in BRAFi-resistant xenografts. These data identify a molecular pathway for drug resistance connecting BRAFi, the ER stress response, and autophagy and provide a rationale for combination approaches targeting this resistance pathway. PMID:24569374

Ma, Xiao-Hong; Piao, Sheng-Fu; Dey, Souvik; Mcafee, Quentin; Karakousis, Giorgos; Villanueva, Jessie; Hart, Lori S.; Levi, Samuel; Hu, Janice; Zhang, Gao; Lazova, Rossitza; Klump, Vincent; Pawelek, John M.; Xu, Xiaowei; Xu, Wei; Schuchter, Lynn M.; Davies, Michael A.; Herlyn, Meenhard; Winkler, Jeffrey; Koumenis, Constantinos; Amaravadi, Ravi K.

2014-01-01

217

ERK inhibitor U0126 enhanced SDT-induced cytotoxicity of human leukemia U937 cells.  

PubMed

This study was to investigate the cell killing effect of chlorin-e6 (Ce6) mediated sonodynamic therapy (SDT) on human leukemia U937 cells and explore the role of ERK signal pathway in the process. The ultrastructure changes of U937 cells induced by ultrasonic irradiation were evaluated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The viability of cells was evaluated by viacount assay. Apoptosis was analyzed using ?ow cytometer as well as ?uorescence microscopy with 4'-6-diamidino-2-phenylindole (DAPI) staining. Western blotting was used to analyze the expression of mitogen-activated protein kinase (MAPK). Intracellular reactive oxygen species (ROS) and mitochondria membrane potential (MMP) levels were also analyzed by ?ow cytometer after exposure. Our experiments showed that several distinct sonochemical effects were found after Ce6-mediated SDT treatment. Western blotting analysis indicated that the MAPK were activated. Especially, pre-treatment with ERK inhibitor U0126 could additionally enhance SDT-induced cell viability loss, early- and late-apoptotic rate, chromatin condensation, DNA fragmentation and caspase-3 activation. Besides, a mass of ROS accumulation and a conspicuous loss of mitochondrial membrane potential were detected in U937 cells. These ?ndings suggested ERK signal pathway may deliver a survival signal which counteracts SDT-induced cell death, while combination with U0126 could significantly potentiate the SDT-induced cytotoxic effect in U937 cells. PMID:24448375

Su, Xiaomin; Wang, Xiaobing; Zhang, Kun; Yang, Shuang; Xue, Qin; Wang, Pan; Liu, Quanhong

2014-01-01

218

Diabetes or peroxisome proliferator-activated receptor alpha agonist increases mitochondrial thioesterase I activity in heart  

Technology Transfer Automated Retrieval System (TEKTRAN)

Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a transcriptional regulator of the expression of mitochondrial thioesterase I (MTE-I) and uncoupling protein 3 (UCP3), which are induced in the heart at the mRNA level in response to diabetes. Little is known about the regulation of pr...

219

IDENTIFICATION OF EARLY MOLECULAR EVENTS AFTER PEROXISOME PROLIFERATOR EXPOSURE IN THE RODENT LIVER  

EPA Science Inventory

Peroxisome proliferators (PP) are a large class of structurally diverse chemicals that mediate their effects in the liver mainly through the PP-activated receptor a(PPARa). Development of PP induced hepatocarcinogenesis in mouse liver is known to be dependent on PPARa but do...

220

PPARÁ-DEPENDENT GENE EXPRESSION CHANGES IN THE MOUSE LIVER AFTER EXPOSURE TO PEROXISOME PROLIFERATORS  

EPA Science Inventory

Peroxisome proliferators (PP) are a large class of structurally diverse chemicals that mediate their effects in the liver mainly through the PP-activated receptor ¿ (PPAR?). Development of PP induced hepatocarcinogenesis in mouse liver is known to be dependent on PPAR&#...

221

Inhibitors of the 5-lipoxygenase arachidonic acid pathway induce ATP release and ATP-dependent organic cation transport in macrophages.  

PubMed

We have previously described that arachidonic acid (AA)-5-lipoxygenase (5-LO) metabolism inhibitors such as NDGA and MK886, inhibit cell death by apoptosis, but not by necrosis, induced by extracellular ATP (ATPe) binding to P2X7 receptors in macrophages. ATPe binding to P2X7 also induces large cationic and anionic organic molecules uptake in these cells, a process that involves at least two distinct transport mechanisms: one for cations and another for anions. Here we show that inhibitors of the AA-5-LO pathway do not inhibit P2X7 receptors, as judged by the maintenance of the ATPe-induced uptake of fluorescent anionic dyes. In addition, we describe two new transport phenomena induced by these inhibitors in macrophages: a cation-selective uptake of fluorescent dyes and the release of ATP. The cation uptake requires secreted ATPe, but, differently from the P2X7/ATPe-induced phenomena, it is also present in macrophages derived from mice deficient in the P2X7 gene. Inhibitors of phospholipase A2 and of the AA-cyclooxygenase pathway did not induce the cation uptake. The uptake of non-organic cations was investigated by measuring the free intracellular Ca(2+) concentration ([Ca(2+)]i) by Fura-2 fluorescence. NDGA, but not MK886, induced an increase in [Ca(2+)]i. Chelating Ca(2+) ions in the extracellular medium suppressed the intracellular Ca(2+) signal without interfering in the uptake of cationic dyes. We conclude that inhibitors of the AA-5-LO pathway do not block P2X7 receptors, trigger the release of ATP, and induce an ATP-dependent uptake of organic cations by a Ca(2+)- and P2X7-independent transport mechanism in macrophages. PMID:24743022

da Silva-Souza, Hercules Antônio; Lira, Maria Nathalia de; Costa-Junior, Helio Miranda; da Cruz, Cristiane Monteiro; Vasconcellos, Jorge Silvio Silva; Mendes, Anderson Nogueira; Pimenta-Reis, Gabriela; Alvarez, Cora Lilia; Faccioli, Lucia Helena; Serezani, Carlos Henrique; Schachter, Julieta; Persechini, Pedro Muanis

2014-07-01

222

Protective effect of inducible nitric oxide synthase inhibitor on pancreas transplantation in rats  

PubMed Central

AIM: To investigate the effect of inducible nitric oxide synthase inhibitor, aminoguanidine, on pancreas transplantation in rats. METHODS: A model of pancreas transplantation was established in rats. Streptozotocin-induced diabetic male Wistar rats were randomly assigned to sham-operation control group (n = 6), transplant control group (n = 6), and aminoguanidine (AG) treatment group (n = 18). In the AG group, aminoguanidine was added to intravascular infusion as the onset of reperfusion at the dose of 60 mg/kg, 80 mg/kg, 100 mg/kg body weight, respectively. Serum nitric oxide (NO) level, blood sugar and amylase activity were detected. Nitric oxide synthase (NOS) test kit was used to detect the pancreas cNOS and inducible NOS (iNOS) activity. Pancreas sections stained with HE and immunohistochemistry were evaluated under a light microscope. RESULTS: As compared with the transplant control group, the serum NO level and amylase activity decreased obviously and the evidence for pancreas injury was much less in the AG group. The AG (80 mg/kg body weight) group showed the most significant difference in NO and amylase (NO: 66.0 ± 16.6 vs 192.3 ± 60.0, P < 0.01 and amylase: 1426 ± 177 vs 4477 ± 630, P < 0.01).The expression and activity of tissue iNOS, and blood sugar in the AG (80 mg/kg body weight) group were much lower than those in the transplant control group (iNOS: 2.01 ± 0.23 vs 26.59 ± 5.78, P < 0.01 and blood sugar: 14.2 ± 0.9 vs 16.8 ± 1.1, P < 0.01). CONCLUSION: Selective iNOS inhibitor, aminoguanidine as a free radical, has a protective effect on pancreas transplantation in rats by inhibiting NO and reducing its toxicity. PMID:18023101

Li, Bai-Feng; Liu, Yong-Feng; Cheng, Ying; Zhang, Ke-Zhong; Li, Tie-Min; Zhao, Ning

2007-01-01

223

B-Raf Inhibitors Induce Epithelial Differentiation in BRAF-Mutant Colorectal Cancer Cells.  

PubMed

BRAF mutations are associated with aggressive, less-differentiated and therapy-resistant colorectal carcinoma. However, the underlying mechanisms for these correlations remain unknown. To understand how oncogenic B-Raf contributes to carcinogenesis, in particular to aspects other than cellular proliferation and survival, we generated three isogenic human colorectal carcinoma cell line models in which we can dynamically modulate the expression of the B-Raf(V600E) oncoprotein. Doxycyclin-inducible knockdown of endogenous B-Raf(V600E) decreases cellular motility and invasion in conventional and three-dimensional (3D) culture, whereas it promotes cell-cell contacts and induces various hallmarks of differentiated epithelia. Importantly, all these effects are recapitulated by B-Raf (PLX4720, vemurafenib, and dabrafenib) or MEK inhibitors (trametinib). Surprisingly, loss of B-Raf(V600E) in HT29 xenografts does not only stall tumor growth, but also induces glandular structures with marked expression of CDX2, a tumor-suppressor and master transcription factor of intestinal differentiation. By performing the first transcriptome profiles of PLX4720-treated 3D cultures of HT29 and Colo-205 cells, we identify several upregulated genes linked to epithelial differentiation and effector functions, such as claudin-1, a Cdx-2 target gene encoding a critical tight junction component. Thereby, we provide a mechanism for the clinically observed correlation between mutant BRAF and the loss of Cdx-2 and claudin-1. PLX4720 also suppressed several metastasis-associated transcripts that have not been implicated as targets, effectors or potential biomarkers of oncogenic B-Raf signaling so far. Together, we identify a novel facet of clinically applied B-Raf or MEK inhibitors by showing that they promote cellular adhesion and differentiation of colorectal carcinoma cells. Cancer Res; 75(1); 216-29. ©2014 AACR. PMID:25381152

Herr, Ricarda; Köhler, Martin; Andrlová, Hana; Weinberg, Florian; Möller, Yvonne; Halbach, Sebastian; Lutz, Lisa; Mastroianni, Justin; Klose, Martin; Bittermann, Nicola; Kowar, Silke; Zeiser, Robert; Olayioye, Monilola A; Lassmann, Silke; Busch, Hauke; Boerries, Melanie; Brummer, Tilman

2015-01-01

224

Tissue Inhibitor of Matrix Metalloproteinase-1 Mediates Erythropoietin-induced Neuroprotection in Hypoxia Ischemia  

PubMed Central

Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However theses studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and if its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia Ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice-Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2 hours with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48 hours after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2, STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO’s protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury. PMID:21689752

Souvenir, Rhonda; Fathali, Nancy; Ostrowski, Robert P.; Lekic, Tim; Zhang, John H.; Tang, Jiping

2011-01-01

225

Isoflurane-Induced Spatial Memory Impairment in Mice is Prevented by the Acetylcholinesterase Inhibitor Donepezil  

PubMed Central

Although many studies have shown that isoflurane exposure impairs spatial memory in aged animals, there are no clinical treatments available to prevent this memory deficit. The anticholinergic properties of volatile anesthetics are a biologically plausible cause of cognitive dysfunction in elderly subjects. We hypothesized that pretreatment with the acetylcholinesterase inhibitor donepezil, which has been approved by the Food and Drug Administration (FDA) for the treatment of Alzheimer's disease, prevents isoflurane-induced spatial memory impairment in aged mice. In present study, eighteen-month-old mice were administered donepezil (5 mg/kg) or an equal volume of saline by oral gavage with a feeding needle for four weeks. Then the mice were exposed to isoflurane (1.2%) for six hours. Two weeks later, mice were subjected to the Morris water maze to examine the impairment of spatial memory after exposure to isoflurane. After the behavioral test, the mice were sacrificed, and the protein expression level of acetylcholinesterase (AChE), choline acetylase (ChAT) and ?7 nicotinic receptor (?7-nAChR) were measured in the brain. Each group consisted of 12 mice. We found that isoflurane exposure for six hours impaired the spatial memory of the mice. Compared with the control group, isoflurane exposure dramatically decreased the protein level of ChAT, but not AChE or ?7-nAChR. Donepezil prevented isoflurane-induced spatial memory impairments and increased ChAT levels, which were downregulated by isoflurane. In conclusions, pretreatment with the AChE inhibitor donepezil prevented isoflurane-induced spatial memory impairment in aged mice. The mechanism was associated with the upregulation of ChAT, which was decreased by isoflurane. PMID:22114680

Wang, Beilei; Xu, Huan; Li, Wen; Chen, Jie; Wang, Xiangrui

2011-01-01

226

Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram  

SciTech Connect

Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. -- Highlights: ? Chlorine causes lung injury when inhaled and is considered a chemical threat agent. ? Rolipram inhibited chlorine-induced pulmonary edema and airway hyperreactivity. ? Post-exposure rolipram treatments by both systemic and local delivery were effective. ? Rolipram shows promise as a rescue treatment for chlorine-induced lung injury.

Chang, Weiyuan; Chen, Jing; Schlueter, Connie F. [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States)] [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States); Rando, Roy J. [Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University Health Sciences Center, New Orleans, LA (United States)] [Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University Health Sciences Center, New Orleans, LA (United States); Pathak, Yashwant V. [College of Pharmacy, University of South Florida, Tampa, FL (United States)] [College of Pharmacy, University of South Florida, Tampa, FL (United States); Hoyle, Gary W., E-mail: Gary.Hoyle@louisville.edu [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States)

2012-09-01

227

Natural Product-Based Inhibitors of Hypoxia-Inducible Factor-1 (HIF-1)  

PubMed Central

The transcription factor hypoxia-inducible factor-1 (HIF-1) regulates the expression of more than 70 genes involved in cellular adaptation and survival under hypoxic stress. Activation of HIF-1 is associated with numerous physiological and pathological processes that include tumorigenesis, vascular remodeling, inflammation, and hypoxia/ischemia-related tissue damage. Clinical studies suggested that HIF-1 activation correlates directly with advanced disease stages and treatment resistance among cancer patients. Preclinical studies support the inhibition of HIF-1 as a major molecular target for antitumor drug discovery. Considerable effort is underway, in government laboratories, industry and academia, to identify therapeutically useful small molecule HIF-1 inhibitors. Natural products (low molecular weight organic compounds produced by plants, microbes, and animals) continue to play a major role in modern antitumor drug discovery. Most of the compounds discovered to inhibit HIF-1 are natural products or synthetic compounds with structures that are based on natural product leads. Natural products have also served a vital role as molecular probes to elucidate the pathways that regulate HIF-1 activity. Natural products and natural product-derived compounds that inhibit HIF-1 are summarized in light of their biological source, chemical class, ancd effect on HIF-1 and HIF-mediated gene regulation. When known, the mechanism(s) of action of HIF-1 inhibitors are described. Many of the substances found to inhibit HIF-1 are non-druggable compounds that are too cytotoxic to serve as drug leads. The application of high-throughput screening methods, complementary molecular-targeted assays, and structurally diverse chemical libraries hold promise for the discovery of therapeutically useful HIF-1 inhibitors. PMID:16515532

Nagle, Dale G.; Zhou, Yu-Dong

2010-01-01

228

Identification of an acetylation-dependant Ku70/FLIP complex that regulates FLIP expression and HDAC inhibitor-induced apoptosis  

PubMed Central

FLIP is a potential anti-cancer therapeutic target that inhibits apoptosis by blocking caspase 8 activation by death receptors. We report a novel interaction between FLIP and the DNA repair protein Ku70 that regulates FLIP protein stability by inhibiting its polyubiquitination. Furthermore, we found that the histone deacetylase (HDAC) inhibitor Vorinostat (SAHA) enhances the acetylation of Ku70, thereby disrupting the FLIP/Ku70 complex and triggering FLIP polyubiquitination and degradation by the proteasome. Using in vitro and in vivo colorectal cancer models, we further demonstrated that SAHA-induced apoptosis is dependant on FLIP downregulation and caspase 8 activation. In addition, an HDAC6-specific inhibitor Tubacin recapitulated the effects of SAHA, suggesting that HDAC6 is a key regulator of Ku70 acetylation and FLIP protein stability. Thus, HDAC inhibitors with anti-HDAC6 activity act as efficient post-transcriptional suppressors of FLIP expression and may, therefore, effectively act as ‘FLIP inhibitors'. PMID:22322857

Kerr, E; Holohan, C; McLaughlin, K M; Majkut, J; Dolan, S; Redmond, K; Riley, J; McLaughlin, K; Stasik, I; Crudden, M; Van Schaeybroeck, S; Fenning, C; O'Connor, R; Kiely, P; Sgobba, M; Haigh, D; Johnston, P G; Longley, D B

2012-01-01

229

Angiotensin-converting enzyme inhibitor (enalapril maleate) accelerates recovery of mouse skin from UVB-induced wrinkles  

SciTech Connect

Highlights: •Angiotensin converting enzyme (ACE) increases in UVB-irradiated skin. •Administration of an ACE inhibitor improved UVB-induced skin wrinkle. •ACE inhibitor improved UVB-induced epidermal hypertrophy. •ACE inhibitor improved transepidermal water loss in the UVB-irradiated skin. -- Abstract: Angiotensin-converting enzyme (ACE) activity and angiotensin II signaling regulate cell proliferation, differentiation, and tissue remodeling, as well as blood pressure, while in skin, angiotensin II signaling is involved in wound healing, inflammation, and pathological scar formation. Therefore, we hypothesized that angiotensin II is also involved in photoaging of skin. In this study, we examined the effect of enalapril maleate, an ACE inhibitor, on recovery of wrinkled skin of hairless mice exposed to long-term UVB irradiation. Immunohistochemical observation revealed that expression of ACE, angiotensin II, and angiotensin II type 1 (AT1) and type 2 (AT2) receptors in the skin was increased after UVB irradiation (3 times/week at increasing intensities for 8 weeks). Administration of enalapril maleate (5 times/week for 6 weeks, starting 1 week after 10-week irradiation) accelerated recovery from UVB-induced wrinkles, epidermal hyperplasia and epidermal barrier dysfunction, as compared with the vehicle control. Our results indicate that ACE and angiotensin II activity are involved in skin photoaging, and suggest that ACE inhibitor such as enalapril maleate may have potential for improvement of photoaged skin.

Matsuura-Hachiya, Yuko; Arai, Koji Y.; Ozeki, Rieko; Kikuta, Ayako; Nishiyama, Toshio, E-mail: toshio_n@cc.tuat.ac.jp

2013-12-06

230

Thrombocytopenia induced by the histone deacetylase inhibitor abexinostat involves p53-dependent and -independent mechanisms  

PubMed Central

Abexinostat is a pan histone deacetylase inhibitor (HDACi) that demonstrates efficacy in malignancy treatment. Like other HDACi, this drug induces a profound thrombocytopenia whose mechanism is only partially understood. We have analyzed its effect at doses reached in patient plasma on in vitro megakaryopoiesis derived from human CD34+ cells. When added at day 0 in culture, abexinostat inhibited CFU-MK growth, megakaryocyte (MK) proliferation and differentiation. These effects required only a short incubation period. Decreased proliferation was due to induction of apoptosis and was not related to a defect in TPO/MPL/JAK2/STAT signaling. When added later (day 8), the compound induced a dose-dependent decrease (up to 10-fold) in proplatelet (PPT) formation. Gene profiling from MK revealed a silencing in the expression of DNA repair genes with a marked RAD51 decrease at protein level. DNA double-strand breaks were increased as attested by elevated ?H2AX phosphorylation level. Moreover, ATM was phosphorylated leading to p53 stabilization and increased BAX and p21 expression. The use of a p53 shRNA rescued apoptosis, and only partially the defect in PPT formation. These results suggest that HDACi induces a thrombocytopenia by a p53-dependent mechanism along MK differentiation and a p53-dependent and -independent mechanism for PPT formation. PMID:23887629

Ali, A; Bluteau, O; Messaoudi, K; Palazzo, A; Boukour, S; Lordier, L; Lecluse, Y; Rameau, P; Kraus-Berthier, L; Jacquet-Bescond, A; Lelièvre, H; Depil, S; Dessen, P; Solary, E; Raslova, H; Vainchenker, W; Plo, I; Debili, N

2013-01-01

231

The JNK inhibitor SP600129 enhances apoptosis of HCC cells induced by the tumor suppressor WWOX  

PubMed Central

Background/Aims The FRA16D fragile site gene WWOX is a tumor suppressor that participates in p53-mediated apoptosis. The c-jun N-terminal kinase JNK1 interacts with WWOX and inhibits apoptosis. We investigated the function of WWOX in human hepatocellular carcinoma (HCC) and the effect of JNK inhibition on WWOX-mediated apoptosis. Methods Allelic imbalance on chromosome 16 was analyzed in 73 HCCs using 53 microsatellite markers. WWOX mRNA in HCC cell lines and primary HCCs was measured by real-time RT-PCR. Effects of WWOX on proliferation and apoptosis and the interaction between WWOX and JNK inhibition were examined. Results Loss on chromosome 16 occurred in 34 of 73 HCCs. Of 11 HCC cell lines, 2 had low, 7 intermediate, and 2 had high WWOX mRNA. Of 51 primary tumors, 23 had low WWOX mRNA. Forced expression of WWOX in SNU387 cells decreased FGF2-mediated proliferation and enhanced apoptosis induced by staurosporine and the JNK inhibitor SP600129. Conversely, knockdown of WWOX in SNU449 cells using shRNA targeting WWOX increased proliferation and resistance to SP600129 induced apoptosis. Conclusions WWOX induces apoptosis and inhibits human HCC cell growth through a mechanism enhanced by JNK inhibition. PMID:18620777

Aderca, Ileana; Moser, Catherine D.; Veerasamy, Manivannan; Bani-Hani, Ahmad H.; Bonilla-Guerrero, Ruben; Ahmed, Kadra; Shire, Abdirashid; Cazanave, Sophie C.; Montoya, Damian P.; Mettler, Teresa A.; Burgart, Lawrence J.; Nagorney, David M.; Thibodeau, Stephen N.; Cunningham, Julie M.; Lai, Jin-Ping; Roberts, Lewis R.

2008-01-01

232

Sensitization to UV-induced apoptosis by the histone deacetylase inhibitor trichostatin A (TSA)  

SciTech Connect

UV-induced apoptosis is a protective mechanism that is primarily caused by DNA damage. Cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts are the main DNA adducts triggered by UV radiation. Because the formation of DNA lesions in the chromatin is modulated by the structure of the nucleosomes, we postulated that modification of chromatin compaction could affect the formation of the lesions and consequently apoptosis. To verify this possibility we treated human colon carcinoma RKO cells with the histone deacetylase inhibitor trichostatin A (TSA) prior to exposure to UV radiation. Our data show that pre-treatment with TSA increased UV killing efficiency by more than threefold. This effect correlated with increased formation of CPDs and consequently apoptosis. On the other hand, TSA treatment after UV exposure rather than before had no more effect than UV radiation alone. This suggests that a primed (opened) chromatin status is required to sensitize the cells. Moreover, TSA sensitization to UV-induced apoptosis is p53 dependent. p53 and acetylation of the core histones may thus contribute to UV-induced apoptosis by modulating the formation of DNA lesions on chromatin.

Kim, Myoung Sook [Department of Otolaryngology-Head and Neck Surgery, Head and Neck Cancer Research Division, Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Baek, Jin Hyen; Chakravarty, Devulapalli [Biochemistry and Molecular Biology Department, School of Medicine, and Greenebaum Cancer Center, University of Maryland, 108 North Greene Street, Room 330, Baltimore, MD 21201-1503 (United States); Sidransky, David [Department of Otolaryngology-Head and Neck Surgery, Head and Neck Cancer Research Division, Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Carrier, France [Biochemistry and Molecular Biology Department, School of Medicine, and Greenebaum Cancer Center, University of Maryland, 108 North Greene Street, Room 330, Baltimore, MD 21201-1503 (United States)]. E-mail: fcarr001@umaryland.edu

2005-05-15

233

Predictive factor and antihypertensive usage of tyrosine kinase inhibitor-induced hypertension in kidney cancer patients  

PubMed Central

Hypertension (HT) is the common adverse event associated with vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKI). The present study was performed to identify the predictive factors of TKI-induced HT and to determine the classes of antihypertensive agents (AHTA) that demonstrate optimal efficacy against this type of HT. The charts of 50 cases of patients that had received VEGFR-TKI treatment were retrospectively examined. The association between patient background and TKI-induced HT, and the effect of administering AHTA were analyzed. High systolic blood pressure at baseline was identified to be a predictive factor for HT. In addition, there was no difference observed between calcium channel blockers (CCBs) and angiotensin receptor II blockers (ARBs) as first-line AHTA for the control of HT. The findings of the present study may aid with predicting the onset of TKI-induced HT, as well as for its management via the primary use of either CCBs or ARBs. PMID:24959266

IZUMI, KOUJI; ITAI, SHINGO; TAKAHASHI, YOSHIKO; MAOLAKE, AERKEN; NAMIKI, MIKIO

2014-01-01

234

Effects of Cytochrome P450 Inhibitors on Itraconazole and Fluconazole Induced Cytotoxicity in Hepatocytes  

PubMed Central

Itraconazole and fluconazole have been reported to induce hepatotoxicity in patients. The present study was designed to investigate the role of cytochrome P450 inhibitors, SKF 525A, and curcumin pretreatment on the cytotoxicity of antifungal drugs fluconazole and itraconazole. For 3 consecutive days, female rats were administered daily SKF 525A or curcumin (5 and 25?mg/kg). Control rats received an equivalent amount of dosed vehicle. The animals were anaesthetized 24 hours after receiving the last dose for liver perfusion. Hepatocytes were then exposed to various concentrations of antifungal drugs. In vitro incubation of hepatocytes with itraconazole revealed significantly lower viability when compared to fluconazole as assessed by lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase activities. The cytotoxicity of itraconazole was enhanced when incubated with hepatocytes pretreated with SKF 525A. SKF 525A had no effects on the cytotoxicity of fluconazole. Curcumin failed to either increase or decrease the cytotoxicity of both antifungal drugs. ATP levels also showed significant decrease in both itraconazole and fluconazole incubated hepatocytes. However, SKF 525A pretreated hepatocytes had significantly lower ATP levels after itraconazole incubations. Collectively, these results confirm the involvement of cytochrome P450 in the cytoprotection in itraconazole induced hepatocyte toxicity. Differences of the effects of SKF 525A on the cytotoxicity induced by itraconazole and fluconazole may be due to the differences on the metabolism of each antifungal drug in vivo. PMID:20130764

Somchit, Nhareet; Ngee, Chong Sock; Yaakob, Azhar; Ahmad, Zuraini; Zakaria, Zainul Amiruddin

2009-01-01

235

Antifibrotic effects of focal adhesion kinase inhibitor in bleomycin-induced pulmonary fibrosis in mice.  

PubMed

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase involved in various biological functions, including cell survival, proliferation, migration, and adhesion. FAK is an essential factor for transforming growth factor ? to induce myofibroblast differentiation. In the present study, we investigated whether the targeted inhibition of FAK by using a specific inhibitor, TAE226, has the potential to regulate pulmonary fibrosis. TAE226 showed inhibitory activity of autophosphorylation of FAK at tyrosine 397 in lung fibroblasts. The addition of TAE226 inhibited the proliferation of lung fibroblasts in response to various growth factors, including platelet-derived growth factor and insulin-like growth factor I, in vitro. TAE226 strongly suppressed the production of type I collagen by lung fibroblasts. Furthermore, treatment of fibroblasts with TAE226 reduced the expression of ?-smooth muscle actin induced by transforming growth factor ?, indicating the inhibition of differentiation of fibroblasts to myofibroblasts. Administration of TAE226 ameliorated the pulmonary fibrosis induced by bleomycin in mice even when used late in the treatment. The number of proliferating mesenchymal cells was reduced in the lungs of TAE226-treated mice. These data suggest that FAK signal plays a significant role in the progression of pulmonary fibrosis and that it can become a promising target for therapeutic approaches to pulmonary fibrosis. PMID:23642017

Kinoshita, Katsuhiro; Aono, Yoshinori; Azuma, Momoyo; Kishi, Jun; Takezaki, Akio; Kishi, Masami; Makino, Hideki; Okazaki, Hiroyasu; Uehara, Hisanori; Izumi, Keisuke; Sone, Saburo; Nishioka, Yasuhiko

2013-10-01

236

A protease inhibitor against acute stress-induced visceral hypersensitivity and paracellular permeability in rats.  

PubMed

In the present study, we investigated the effects of camostat mesilate (CM), a synthetic protease inhibitor, on visceral sensitivity and paracellular permeability induced by the acute restraint stress. We also explored the possible mechanisms underlying these effects. The acute restraint stress was induced by wrapping the fore shoulders, upper forelimbs and thoracic trunk of Sprague-Dawley rats for 2h. Either CM (30, 100 and 300mg/kg) or saline was intragastrically administrated to the rats 30min before the acute restraint stress. Visceral perception was quantified as visceral motor response with an electromyography in a subset of rats. Paracellular permeability was determined in another subset of rats. We found that the visceral sensitivity and paracellular permeability were significantly reduced in the CM-treated rats. Moreover, the fecal protease activity was decreased in the CM-treated rats. The ZO-1 protein expression was markedly reduced by the stress treatment, but this decrease was suppressed by CM administration. Our data indicated that CM could efficiently inhibit visceral sensitivity and paracellular permeability induced by the acute restraint stress in rats. Therefore, CM might be an effective drug for the treatment of irritable bowel syndrome. PMID:21237151

Zhao, Juhui; Wang, Jinhai; Dong, Lei; Shi, Hongyang; Wang, Zongyan; Ding, Hui; Shi, Haitao; Lu, Xiaolan

2011-03-11

237

Sulfonamides as a New Scaffold for Hypoxia Inducible Factor Pathway Inhibitors  

PubMed Central

Solid tumors generally grow under hypoxic conditions, a pathophysiological change, which activates the expression of genes responsible for malignant, aggressive, and treatment-refractory properties. Hypoxia inducible factor (HIF) is the chief transcription factor regulating hypoxia-driven gene expression. Therefore, the HIF pathway has become a critical target for cancer therapeutics development. We screened a privileged library of about 10,000 natural-product-like compounds using a cell-based assay for HIF-dependent transcriptional activity and identified several arylsulfonamide HIF pathway inhibitors. Among these compounds, the most potent ones showed an IC50 of ~0.5 ?M in the hypoxia-responsive element (HRE)-luciferase reporter system. Further studies are needed to fully elucidate the mechanism of action of this class of compounds and their structure-activity relationship. PMID:21831638

Tan, Chalet; de Noronha, Rita; Devi, Narra S.; Jabbar, Adnan A.; Kaluz, Stefan; Liu, Yuan; Mooring, Suazette Reid; Nicolaou, K.C.; Wang, Binghe; Van Meir, Erwin G.

2011-01-01

238

Management of diarrhea induced by epidermal growth factor receptor tyrosine kinase inhibitors  

PubMed Central

Treatment for non-small-cell lung cancer (nsclc) is moving away from traditional chemotherapy toward personalized medicine. The reversible tyrosine kinase inhibitors (tkis) erlotinib and gefitinib were developed to target the epidermal growth factor receptor (egfr). Afatinib, an irreversible ErbB family blocker, was developed to block egfr (ErbB1), human epidermal growth factor receptor 2 (ErbB2), and ErbB4 signalling, and transphosphorylation of ErbB3. All of the foregoing agents are efficacious in treating nsclc, and their adverse event profile is different from that of chemotherapy. Two of the most common adverse events with egfr tkis are rash and diarrhea. Here, we focus on diarrhea. The key to successful management of diarrhea is to treat early and aggressively using patient education, diet, and antidiarrheal medications such as loperamide. We also present strategies for the effective assessment and management of egfr tki–induced diarrhea. PMID:25489260

Hirsh, V.; Blais, N.; Burkes, R.; Verma, S.; Croitoru, K.

2014-01-01

239

Silencing of the polyamine catabolic key enzyme SSAT prevents CDK inhibitor-induced apoptosis in Caco-2 colon cancer cells  

PubMed Central

Roscovitine and purvalanol are purine derivative cyclin-dependent kinase (CDK) inhibitors that induce apoptosis in various types of cancer cells. However, their impact on the apoptotic cell death mechanism requires further elucidation. Natural polyamines putrescine, spermidine and spermine play essential roles in the regulation of cell growth and proliferation. Increased levels of polyamines in cells are considered to be involved in cancer progression. Intracellular polyamine levels are under the control of several catabolic enzymes, such as spermidine/spermine-N-acetyl transferase (SSAT), acetylpolyamine oxidase (APAO) and spermine oxidase (SMO), which could be altered by several therapeutic drugs. However, the possible role of polyamines in drug-induced apoptosis has yet to be clarified. In the present study, our aim was to determine the modulation of the polyamine catabolic pathway related to CDK inhibitor-induced apoptosis in Caco-2 cells. We found that roscovitine and purvalanol (each 20 ?M) induced apoptosis by activating caspase-9 and -3, and inhibiting the mitochondrial membrane potential in Caco-2 cells. CDK inhibitors decreased the intracellular putrescine and spermine levels without affecting spermidine levels. Although both roscovitine and purvalanol induced SSAT expression, they did not exert a significant effect on the APAO expression profile. SSAT transient silencing prevented roscovitine-induced apoptosis compared to parental cells. Thus, we concluded that roscovitine and purvalanol significantly induce apoptosis in Caco-2 cells by modulating the polyamine catabolism, and that SSAT could be an important target in evaluating the potential role of polyamines in apoptotic cell death. PMID:22294330

ÇOKER, A.; ARISAN, E.D.; PALAVAN-ÜNSAL, N.

2012-01-01

240

Genetics Home Reference: Peroxisomal acyl-CoA oxidase deficiency  

MedlinePLUS

... oxidase. This enzyme is found in sac-like cell structures (organelles) called peroxisomes, which contain a variety of enzymes that break down many different substances. The peroxisomal straight-chain acyl-CoA oxidase ... gene mutations prevent the peroxisomal straight-chain ...

241

USP7 inhibitor P22077 inhibits neuroblastoma growth via inducing p53-mediated apoptosis.  

PubMed

Neuroblastoma (NB) is a common pediatric cancer and contributes to more than 15% of all pediatric cancer-related deaths. Unlike adult tumors, recurrent somatic mutations in NB, such as tumor protein 53 (p53) mutations, occur with relative paucity. In addition, p53 downstream function is intact in NB cells with wild-type p53, suggesting that reactivation of p53 may be a viable therapeutic strategy for NB treatment. Herein, we report that the ubiquitin-specific protease 7 (USP7) inhibitor, P22077, potently induces apoptosis in NB cells with an intact USP7-HDM2-p53 axis but not in NB cells with mutant p53 or without human homolog of MDM2 (HDM2) expression. In this study, we found that P22077 stabilized p53 by inducing HDM2 protein degradation in NB cells. P22077 also significantly augmented the cytotoxic effects of doxorubicin (Dox) and etoposide (VP-16) in NB cells with an intact USP7-HDM2-p53 axis. Moreover, P22077 was found to be able to sensitize chemoresistant LA-N-6 NB cells to chemotherapy. In an in vivo orthotopic NB mouse model, P22077 significantly inhibited the xenograft growth of three NB cell lines. Database analysis of NB patients shows that high expression of USP7 significantly predicts poor outcomes. Together, our data strongly suggest that targeting USP7 is a novel concept in the treatment of NB. USP7-specific inhibitors like P22077 may serve not only as a stand-alone therapy but also as an effective adjunct to current chemotherapeutic regimens for treating NB with an intact USP7-HDM2-p53 axis. PMID:24136231

Fan, Y-H; Cheng, J; Vasudevan, S A; Dou, J; Zhang, H; Patel, R H; Ma, I T; Rojas, Y; Zhao, Y; Yu, Y; Zhang, H; Shohet, J M; Nuchtern, J G; Kim, E S; Yang, J

2013-01-01

242

Mitigation and Treatment of Radiation-Induced Thoracic Injury With a Cyclooxygenase-2 Inhibitor, Celecoxib  

SciTech Connect

Purpose: To test whether a cyclooxygenase-2 inhibitor (celecoxib) could reduce mortality resulting from radiation-induced pneumonitis. Methods and Materials: Celecoxib was given to mice twice daily for 40 consecutive days starting on the day of local thoracic irradiation (LTI) or 40 or 80 days later. C3Hf/KamLaw mice were observed for morbidity, and time to death was determined. Results were analyzed using the Cox proportional hazards model. Results: Timing of celecoxib relative to LTI determined efficacy. A significant reduction in time to death was achieved only when celecoxib was started 80 days after LTI, corresponding to the time when pneumonitis is expressed. For these mice the reduction in mortality was quantified as a hazard ratio for mortality of treated vs untreated of 0.36 (95% confidence interval [CI] 0.24-0.53), thus significantly less than 1.0. Correspondingly, the median lethal dose for treated mice (12.9 Gy; 95% CI 12.55-13.25 Gy) was significantly (P=.026) higher than for untreated mice (12.4 Gy; 95% CI 12.2-12.65 Gy). Conclusions: Celecoxib significantly reduced lung toxicity when administered months after LTI when the deleterious effects of radiation were expressed. The schedule-dependent reduction in fatal pneumonitis suggests that celecoxib could be clinically useful by reintroduction of treatment months after completion of radiation therapy. These findings may be important for designing clinical trials using cyclooxygenase-2 inhibitors to treat radiation-induced lung toxicity as a complement to concurrent radiation therapy of lung cancers.

Hunter, Nancy R.; Valdecanas, David [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao Zhongxing [Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Milas, Luka [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Thames, Howard D. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mason, Kathy A., E-mail: kmason@mdanderson.org [Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2013-02-01

243

Peroxisome proliferator-activated receptors for hypertension  

PubMed Central

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear receptor superfamily, which is composed of four members encoded by distinct genes (?, ?, ?, and ?). The genes undergo transactivation or transrepression under specific mechanisms that lead to the induction or repression of target gene expression. As is the case with other nuclear receptors, all four PPAR isoforms contain five or six structural regions in four functional domains; namely, A/B, C, D, and E/F. PPARs have many functions, particularly functions involving control of vascular tone, inflammation, and energy homeostasis, and are, therefore, important targets for hypertension, obesity, obesity-induced inflammation, and metabolic syndrome in general. Hence, PPARs also represent drug targets, and PPAR? and PPAR? agonists are used clinically in the treatment of dyslipidemia and type 2 diabetes mellitus, respectively. Because of their pleiotropic effects, they have been identified as active in a number of diseases and are targets for the development of a broad range of therapies for a variety of diseases. It is likely that the range of PPAR? agonist therapeutic actions will result in novel approaches to lifestyle and other diseases. The combination of PPARs with reagents or with other cardiovascular drugs, such as diuretics and angiotensin II receptor blockers, should be studied. This article provides a review of PPAR isoform characteristics, a discussion of progress in our understanding of the biological actions of PPARs, and a summary of PPAR agonist development for patient management. We also include a summary of the experimental and clinical evidence obtained from animal studies and clinical trials conducted to evaluate the usefulness and effectiveness of PPAR agonists in the treatment of lifestyle-related diseases. PMID:25228953

Usuda, Daisuke; Kanda, Tsugiyasu

2014-01-01

244

A small molecule inhibitor of ubiquitin-specific protease-7 induces apoptosis in multiple myeloma cells and overcomes bortezomib resistance.  

PubMed

Bortezomib therapy has proven successful for the treatment of relapsed/refractory, relapsed, and newly diagnosed multiple myeloma (MM); however, dose-limiting toxicities and the development of resistance limit its long-term utility. Here, we show that P5091 is an inhibitor of deubiquitylating enzyme USP7, which induces apoptosis in MM cells resistant to conventional and bortezomib therapies. Biochemical and genetic studies show that blockade of HDM2 and p21 abrogates P5091-induced cytotoxicity. In animal tumor model studies, P5091 is well tolerated, inhibits tumor growth, and prolongs survival. Combining P5091 with lenalidomide, HDAC inhibitor SAHA, or dexamethasone triggers synergistic anti-MM activity. Our preclinical study therefore supports clinical evaluation of USP7 inhibitor, alone or in combination, as a potential MM therapy. PMID:22975377

Chauhan, Dharminder; Tian, Ze; Nicholson, Benjamin; Kumar, K G Suresh; Zhou, Bin; Carrasco, Ruben; McDermott, Jeffrey L; Leach, Craig A; Fulcinniti, Mariaterresa; Kodrasov, Matthew P; Weinstock, Joseph; Kingsbury, William D; Hideshima, Teru; Shah, Parantu K; Minvielle, Stephane; Altun, Mikael; Kessler, Benedikt M; Orlowski, Robert; Richardson, Paul; Munshi, Nikhil; Anderson, Kenneth C

2012-09-11

245

The polyamine oxidase inhibitor MDL-72,527 selectively induces apoptosis of transformed hematopoietic cells through lysosomotropic effects.  

PubMed

Polyamine oxidase functions in the polyamine catabolic pathway, converting N1-acetyl-spermidine and -spermine into putrescine (Put) and spermidine (Spd), respectively, thereby facilitating homeostasis of intracellular polyamine pools. Inhibition of polyamine oxidase in hematopoietic cells by a specific inhibitor, N,N'-bis(2,3-butadienyl)-1,4-butanediamine (MDL-72,527), reduces the levels of Put and Spd and induces the accumulation of N1-acetylated Spd. Although previously thought to be relatively nontoxic, we now report that this inhibitor overrides survival factors to induce cell death of several immortal and malignant murine and human hematopoietic cells, but not of primary myeloid progenitors. Cells treated with MDL-72,527 displayed biochemical changes typical of apoptosis, and cell death was associated with the down-regulation of the antiapoptotic protein Bcl-X(L). However, enforced overexpression of Bcl-X(L), or treatment with the universal caspase inhibitor zVAD-fmk, failed to block MDL-72,527-induced apoptosis in these hematopoietic cells. Despite decreases in Put and Spd pools, MDL-72,527-induced apoptosis was not blocked by cotreatment with exogenous Put or Spd, nor was it influenced by overexpression or inhibition of the polyamine biosynthetic enzyme ornithine decarboxylase. Significantly, MDL-72,527-induced apoptosis was associated with the rapid formation of numerous lysosomally derived vacuoles. Malignant leukemia cells were variably sensitive to the lysosomotropic effects of MDL-72,527, yet pretreatment with the ornithine decarboxylase inhibitor L-alpha-difluoromethylornithine sensitized all of these leukemia cells to the deleterious effects of the inhibitor by stimulating its intracellular accumulation. The lysosomotropic nature of select polyamine analogues may, thus, provide a novel chemotherapeutic strategy to selectively induce apoptosis of malignant hematopoietic cells. PMID:10519408

Dai, H; Kramer, D L; Yang, C; Murti, K G; Porter, C W; Cleveland, J L

1999-10-01

246

Mechanisms of angiotensin-converting enzyme inhibitor induced thrombolysis in Wistar rats.  

PubMed

Our in vivo assay for thrombolysis consisted of recording the weight of platelet-rich thrombi adhering to a collagen strip that was superfused with arterial blood in extracorporal circulation of anaesthetised Wistar rats. Immediate thrombolysis occurred in response to intravenously administrated angiotensin-converting enzyme inhibitor (ACE-I) at non-hypotensive doses of 3-30 microg kg(-1) (captoprilinhibitors (aspirin at a low dose of 1 mg kg(-1), SC 560 and acetaminophen, 0.3-3 mg kg(-1)) slightly augmented thrombolysis by ACE-I, while COX-2 inhibitors (nimesulide and coxibs at doses <1 mg kg(-1) and aspirin at a high dose of 50 mg kg(-1)) or a kinin B2 receptor antagonist (icatibant) abolished it. NOS inhibition by L-NAME blunted and delayed thrombolysis by ACE-I. In parallel to maximum thrombolysis by quinapril (30 microg kg(-1)), plasma levels of 6-keto-PGF1alpha rose significantly from 40 +/- 7 to 554 +/- 91 pg ml(-1) (n=5, mean +/- S.D.), while basal levels of PGE2 (12 +/- 3 pg ml(-1)) and TXB2 (47 +/- 11 pg ml(-1)) remained essentially unchanged. Pretreatment with celecoxib (0.1-1.0 mg kg(-1)) abolished not only thrombolysis by quinapril but also the quinapril-induced rise in plasma 6-keto-PGF1alpha. In cultured bovine aortic endothelial cells, perindoprilate (30 microM) increased cytosolic free calcium [Ca2+]i, but this effect was by three to four orders of magnitude weaker than that of bradykinin (Bk). In aortas of Wistar rats, the transcripts of COX-2 and PGI-S were overexpressed as compared to COX-1. Thus, in blood vessels of Wistar rats, the preferable route of the PGI2 generation might lead through the COX-2 pathway. We conclude that in Wistar rats, ACE-I induces thrombolysis via accumulation of endogenous kinins over the endothelium and a subsequent activation of B2 receptors followed by the release of prostacyclin and nitric oxide. Thrombolysis by ACE-I seems to be mediated mainly through prostacyclin that is made by COX-2. It may well be that an increase in endothelial [Ca2+]i by ACE-I activates phospholipase A2, which supplies COX-2 with the substrate for making thrombolytic prostacyclin. PMID:14592556

Gryglewski, Richard J; Swies, Józef; Uracz, Wojciech; Ch?opicki, Stefan; Marcinkiewicz, Ewa

2003-06-15

247

A novel aggregation-induced emission based fluorescent probe for an angiotensin converting enzyme (ACE) assay and inhibitor screening.  

PubMed

A 'turn-on' fluorescent probe based on aggregation-induced emission (AIE) has been developed. It exhibits excellent selectivity and sensitivity for monitoring angiotensin converting enzyme (ACE) activity both in solutions and in living cells as well as for screening ACE inhibitors in vitro. PMID:25329757

Wang, Haibo; Huang, Yi; Zhao, Xiaoping; Gong, Wan; Wang, Yi; Cheng, Yiyu

2014-12-11

248

Changes in Metalloproteinase and Tissue Inhibitor of Metalloproteinase during Tachycardia-Induced Cardiomyopathy by Rapid Atrial Pacing in Dogs  

Microsoft Academic Search

Background: It was the aim of this study to investigate the variation in metalloproteinase and tissue inhibitor of metalloproteinase (TIMP) connexin levels during tachycardia-induced cardiomyopathy (TIC). Methods: Canine models of TIC were established by rapid right atrial pacing at 350–400 beats per min for 8 weeks in 11 dogs, with another 6 dogs acting as sham operation group. Echocardiography, left

Jing-quan Zhong; Wei Zhang; Yan Li; Ming Zhong; Duoling Li; Cheng Zhang; Yun Zhang

2006-01-01

249

The Proteome of Human Liver Peroxisomes: Identification of Five New Peroxisomal Constituents by a Label-Free Quantitative Proteomics Survey  

PubMed Central

The peroxisome is a key organelle of low abundance that fulfils various functions essential for human cell metabolism. Severe genetic diseases in humans are caused by defects in peroxisome biogenesis or deficiencies in the function of single peroxisomal proteins. To improve our knowledge of this important cellular structure, we studied for the first time human liver peroxisomes by quantitative proteomics. Peroxisomes were isolated by differential and Nycodenz density gradient centrifugation. A label-free quantitative study of 314 proteins across the density gradient was accomplished using high resolution mass spectrometry. By pairing statistical data evaluation, cDNA cloning and in vivo colocalization studies, we report the association of five new proteins with human liver peroxisomes. Among these, isochorismatase domain containing 1 protein points to the existence of a new metabolic pathway and hydroxysteroid dehydrogenase like 2 protein is likely involved in the transport or ?-oxidation of fatty acids in human peroxisomes. The detection of alcohol dehydrogenase 1A suggests the presence of an alternative alcohol-oxidizing system in hepatic peroxisomes. In addition, lactate dehydrogenase A and malate dehydrogenase 1 partially associate with human liver peroxisomes and enzyme activity profiles support the idea that NAD+ becomes regenerated during fatty acid ?-oxidation by alternative shuttling processes in human peroxisomes involving lactate dehydrogenase and/or malate dehydrogenase. Taken together, our data represent a valuable resource for future studies of peroxisome biochemistry that will advance research of human peroxisomes in health and disease. PMID:23460848

Ofman, Rob; Bunse, Christian; Pawlas, Magdalena; Hayen, Heiko; Eisenacher, Martin; Stephan, Christian; Meyer, Helmut E.; Waterham, Hans R.; Erdmann, Ralf; Wanders, Ronald J.; Warscheid, Bettina

2013-01-01

250

Mitochondrial electron-transport-chain inhibitors of complexes I and II induce autophagic cell death mediated by reactive oxygen species.  

PubMed

Autophagy is a self-digestion process important for cell survival during starvation. It has also been described as a form of programmed cell death. Mitochondria are important regulators of autophagy-induced cell death and damaged mitochondria are often degraded by autophagosomes. Inhibition of the mitochondrial electron transport chain (mETC) induces cell death through generating reactive oxygen species (ROS). The role of mETC inhibitors in autophagy-induced cell death is unknown. Herein, we determined that inhibitors of complex I (rotenone) and complex II (TTFA) induce cell death and autophagy in the transformed cell line HEK 293, and in cancer cell lines U87 and HeLa. Blocking the expression of autophagic genes (beclin 1 and ATG5) by siRNAs or using the autophagy inhibitor 3-methyladenine (3-MA) decreased cell death that was induced by rotenone or TTFA. Rotenone and TTFA induce ROS production, and the ROS scavenger tiron decreased autophagy and cell death induced by rotenone and TTFA. Overexpression of manganese-superoxide dismutase (SOD2) in HeLa cells decreased autophagy and cell death induced by rotenone and TTFA. Furthermore, blocking SOD2 expression by siRNA in HeLa cells increased ROS generation, autophagy and cell death induced by rotenone and TTFA. Rotenone- and TTFA-induced ROS generation was not affected by 3-MA, or by beclin 1 and ATG5 siRNAs. By contrast, treatment of non-transformed primary mouse astrocytes with rotenone or TTFA failed to significantly increase levels of ROS or autophagy. These results indicate that targeting mETC complex I and II selectively induces autophagic cell death through a ROS-mediated mechanism. PMID:18032788

Chen, Yongqiang; McMillan-Ward, Eileen; Kong, Jiming; Israels, Sara J; Gibson, Spencer B

2007-12-01

251

Marchantin M: a novel inhibitor of proteasome induces autophagic cell death in prostate cancer cells  

PubMed Central

We previously reported that marchantin M (Mar) is an active agent to induce apoptosis in human prostate cancer (PCa), but the molecular mechanisms of action remain largely unknown. Here, we demonstrate that Mar potently inhibited chymotrypsin-like and peptidyl-glutamyl peptide-hydrolyzing activities of 20S proteasome both in in vitro and intracellular systems and significantly induced the accumulation of polyubiquitinated proteins in PCa cells. The computational modeling analysis suggested that Mar non-covalently bound to active sites of proteasome ?5 and ?1 subunits, resulting in a non-competitive inhibition. Proteasome inhibition by Mar subsequently resulted in endoplasmic reticulum (ER) stress, as evidenced by elevated glucose-regulated protein 78 and CHOP, increased phospho-eukaryotic translation initiation factor 2? (eIF2?), splicing of X-box-binding protein-1 and dilation of the ER. However, Mar-mediated cell death was not completely impaired by a pan inhibitor of caspases. Further studies revealed that the Mar-induced cell death was greatly associated with the activation of autophagy, as indicated by the significant induction of microtubule-associated protein-1 light chain-3 beta (LC3B) expression and conversion. Electron microscopic and green fluorescent protein-tagged LC3B analyses further demonstrated the ability of autophagy induction by Mar. Time kinetic studies revealed that Mar induced a rapid and highly sustained processing of LC3B in treated cells and simultaneously decreased the expression of p62/SQSTM1. Pharmacological blockade or knockdown of LC3B and Atg5 attenuated Mar-mediated cell death. The autophagic response triggered by Mar required the activation of RNA-dependent protein kinase-like ER kinase/eIF2? and suppression of the phosphatidylinositol-3 kinase/Akt/mammalian target of rapamycin axis via preventing activation and expression of Akt. Our results identified a novel mechanism for the cytotoxic effect of Mar, which strengthens it as a potential agent in cancer chemotherapy. PMID:23928700

Jiang, H; Sun, J; Xu, Q; Liu, Y; Wei, J; Young, C Y F; Yuan, H; Lou, H

2013-01-01

252

Induction of early response genes in trypsin inhibitor-induced pancreatic growth.  

PubMed

Endogenous CCK release induced by a synthetic trypsin inhibitor, camostat, stimulates pancreatic growth; however, the mechanisms mediating this growth are not well established. Early response genes often couple short-term signals with long-term responses. To study their participation in the pancreatic growth response, mice were fasted for 18 h and refed chow containing 0.1% camostat for 1-24 h. Expression of 18 early response genes were evaluated by quantitative PCR; mRNA for 17 of the 18 increased at 1, 2, 4, or 8 h. Protein expression for c-jun, c-fos, ATF-3, Egr-1, and JunB peaked at 2 h. Nuclear localization was confirmed by immunohistochemistry of c-fos, c-jun, and Egr-1. Refeeding regular chow induced only a small increase of c-jun and none in c-fos expression. JNKs and ERKs were activated 1 h after camostat feeding as was the phosphorylation of c-jun and ATF-2. AP-1 DNA binding evaluated by EMSA showed a significant increase 1-2 h after camostat feeding with participation of c-jun, c-fos, ATF-2, ATF-3, and JunB shown by supershift. The CCK antagonist IQM-95,333 blocked camostat feeding-induced c-jun and c-fos expression by 67 and 84%, respectively, and AP-1 DNA binding was also inhibited. In CCK-deficient mice, the maximal response of c-jun induction and AP-1 DNA binding were reduced by 64 and 70%, respectively. These results indicate that camostat feeding induces a spectrum of early response gene expression and AP-1 DNA binding and that these effects are mainly CCK dependent. PMID:17095753

Guo, Lili; Sans, Maria Dolors; Gurda, Grzegorz T; Lee, Sae-Hong; Ernst, Stephen A; Williams, John A

2007-02-01

253

Potentiation of temozolomide-induced cytotoxicity: a comparative study of the biological effects of poly(ADP-ribose) polymerase inhibitors.  

PubMed Central

Four poly(ADP-ribose) polymerase (PADPRP) inhibitors [3-aminobenzamide, benzamide, 3,4-dihydro-5-methoxyisoquinolin-1(2H)-one (PD 128763) and 8-hydroxy-2-methylquinazolin-4(3H)-one (NU1025)] were compared with respect to their effects on a number of biological end points. The following parameters were assessed: their ability to inhibit the enzyme in permeabilised L1210 cells; their ability to potentiate the cytotoxicity of temozolomide (including the cytotoxicity of the compounds per se); their ability to increase net levels of temozolomide-induced DNA strand breaks and inhibit temozolomide-induced NAD depletion. PD 128763 and NU1025 were equipotent as PADPRP inhibitors, and 40- and 50-fold more potent than benzamide and 3-aminobenzamide respectively. All the compounds acted in a concentration-dependent manner to potentiate the cytotoxicity and increase DNA strand break levels in cells treated with temozolomide. There was an excellent correlation between the potency of the compounds as PADPRP inhibitors and their effects on cell survival and DNA repair. Temozolomide treatment caused a decrease in cellular NAD levels, and this was abolished by the PADPRP inhibitors. In conclusion, the new generation of PADPRP inhibitors are at least 50-fold more effective than 3-aminobenzamide as chemopotentiators, and can be used at micromolar rather than millimolar concentrations in intact cells. PMID:7547230

Boulton, S.; Pemberton, L. C.; Porteous, J. K.; Curtin, N. J.; Griffin, R. J.; Golding, B. T.; Durkacz, B. W.

1995-01-01

254

Bortezomib, a Proteasome Inhibitor, Attenuates Angiotensin II-Induced Hypertension and Aortic Remodeling in Rats  

PubMed Central

Background Hypertension is a highly prevalent disorder and a major risk factor for cardiovascular diseases. Hypertensive vascular remodeling is the pathological mal-adaption of blood vessels to the hypertensive condition that contributes to further development of high blood pressure and end-organ damage. Hypertensive remodeling involves, at least in part, changes in protein turnover. The ubiquitin proteasome system (UPS) is a major protein quality and quantity control system. This study tested the hypothesis that the proteasome inhibitor, bortezomib, would attenuate AngII-induced hypertension and its sequelae such as aortic remodeling in rats. Methodology/Principal Findings Male Sprague Dawley rats were subjected to AngII infusion for two weeks in the absence or presence of bortezomib. Mean arterial pressure was measured in conscious rats. Aortic tissue was collected for estimation of wall area, collagen deposition and expression of tissue inhibitors of matrix metalloproteases (TIMP), Ki67 (a marker of proliferation), reactive oxygen species (ROS) and VCAM-1 (a marker of inflammation). AngII infusion increased arterial pressure significantly (160±4 mmHg vs. vehicle treatment 133±2 mmHg). This hypertensive response was attenuated by bortezomib (138±5 mmHg). AngII hypertension was associated with significant increases in aortic wall to lumen ratio (?29%), collagen deposition (?14%) and expression of TIMP1 and TIMP2. AngII also increased MMP2 activity, proteasomal chymotrypsin-like activity, Ki67 staining, ROS generation and VCAM-1 immunoreactivity. Co-treatment of AngII-infused rats with bortezomib attenuated these AngII-induced responses. Conclusions Collectively, these data support the idea that proteasome activity contributes to AngII-induced hypertension and hypertensive aortic vascular remodeling at least in part by modulating TIMP1/2 and MMP2 function. Preliminary observations are consistent with a role for ROS, inflammatory and proliferative mechanisms in this effect. Further understanding of the mechanisms by which the proteasome is involved in hypertension and vascular structural remodeling may reveal novel targets for pharmacological treatment of hypertension, hypertensive remodeling or both. PMID:24205262

Li, Shuai; Wang, Xuejun; Li, Yifan; Kost, Curtis K.; Martin, Douglas S.

2013-01-01

255

A lysophosphatidic acid analogue is revealed as a potent inhibitor of phosphatidylcholine synthesis, inducing apoptosis.  

PubMed Central

A previous study demonstrated that cross-desensitization experiments performed with the lysophosphatidic acid (LPA) analogues (R)- and (S)-N-palmitoyl-norleucinol 1-phosphate (PNPAs) inhibited LPA-induced platelet aggregation without any stereospecificity. Here we report opposite biological effects of the two enantiomers on mitogenesis of IMR-90 fibroblasts in relation to their respective metabolism. (R)PNPA was proliferative, while (S)PNPA induced apoptosis by specifically inhibiting phosphatidylcholine biosynthesis at the last step of the CDP-choline pathway controlled by cholinephosphotransferase. This effect was not direct but required dephosphorylation of PNPAs by ecto-lipid phosphate phosphatase before cellular uptake of the generated N-palmitoyl-norleucinols (PNOHs). Inhibition of cholinephosphotransferase by the derivative (S)PNOH was confirmed by an in vitro assay. (S)PNPA proapoptotic effects led us to clarify the mechanism linking cholinephosphotransferase inhibition to apoptosis. Three proapoptotic responses were observed: the activation of caspase-3, the production of ceramides from newly synthesized pools (as demonstrated by the inhibitor Fumonisin B1) and finally the activation of stress-activated protein kinase, p38 and c-Jun N-terminal kinases 1/2, as a result of ceramide increase. Thus our data demonstrate that synthetic analogues of LPA might display stereospecific effects leading to apoptosis independently of classical LPA-activated pathways. PMID:12197836

Gueguen, Geneviéve; Granci, Virginie; Rogalle, Pierre; Briand-Mésange, Fabienne; Wilson, Michéle; Klaébé, Alain; Tercé, François; Chap, Hugues; Salles, Jean-Pierre; Simon, Marie-Françoise; Gaits, Frédérique

2002-01-01

256

A lysophosphatidic acid analogue is revealed as a potent inhibitor of phosphatidylcholine synthesis, inducing apoptosis.  

PubMed

A previous study demonstrated that cross-desensitization experiments performed with the lysophosphatidic acid (LPA) analogues (R)- and (S)-N-palmitoyl-norleucinol 1-phosphate (PNPAs) inhibited LPA-induced platelet aggregation without any stereospecificity. Here we report opposite biological effects of the two enantiomers on mitogenesis of IMR-90 fibroblasts in relation to their respective metabolism. (R)PNPA was proliferative, while (S)PNPA induced apoptosis by specifically inhibiting phosphatidylcholine biosynthesis at the last step of the CDP-choline pathway controlled by cholinephosphotransferase. This effect was not direct but required dephosphorylation of PNPAs by ecto-lipid phosphate phosphatase before cellular uptake of the generated N-palmitoyl-norleucinols (PNOHs). Inhibition of cholinephosphotransferase by the derivative (S)PNOH was confirmed by an in vitro assay. (S)PNPA proapoptotic effects led us to clarify the mechanism linking cholinephosphotransferase inhibition to apoptosis. Three proapoptotic responses were observed: the activation of caspase-3, the production of ceramides from newly synthesized pools (as demonstrated by the inhibitor Fumonisin B1) and finally the activation of stress-activated protein kinase, p38 and c-Jun N-terminal kinases 1/2, as a result of ceramide increase. Thus our data demonstrate that synthetic analogues of LPA might display stereospecific effects leading to apoptosis independently of classical LPA-activated pathways. PMID:12197836

Gueguen, Geneviéve; Granci, Virginie; Rogalle, Pierre; Briand-Mésange, Fabienne; Wilson, Michéle; Klaébé, Alain; Tercé, François; Chap, Hugues; Salles, Jean-Pierre; Simon, Marie-Françoise; Gaits, Frédérique

2002-12-01

257

Knockdown of cyclin-dependent kinase inhibitors induces cardiomyocyte re-entry in the cell cycle.  

PubMed

Proliferation of mammalian cardiomyocytes stops rapidly after birth and injured hearts do not regenerate adequately. High cyclin-dependent kinase inhibitor (CKI) levels have been observed in cardiomyocytes, but their role in maintaining cardiomyocytes in a post-mitotic state is still unknown. In this report, it was investigated whether CKI knockdown by RNA interference induced cardiomyocyte proliferation. We found that triple transfection with p21(Waf1), p27(Kip1), and p57(Kip2) siRNAs induced both neonatal and adult cardiomyocyte to enter S phase and increased the nuclei/cardiomyocyte ratio; furthermore, a subpopulation of cardiomyocytes progressed beyond karyokynesis, as assessed by the detection of mid-body structures and by straight cardiomyocyte counting. Intriguingly, cardiomyocyte proliferation occurred in the absence of overt DNA damage and aberrant mitotic figures. Finally, CKI knockdown and DNA synthesis reactivation correlated with a dramatic change in adult cardiomyocyte morphology that may be a prerequisite for cell division. In conclusion, CKI expression plays an active role in maintaining cardiomyocyte withdrawal from the cell cycle. PMID:21209082

Di Stefano, Valeria; Giacca, Mauro; Capogrossi, Maurizio C; Crescenzi, Marco; Martelli, Fabio

2011-03-11

258

Knockdown of Cyclin-dependent Kinase Inhibitors Induces Cardiomyocyte Re-entry in the Cell Cycle*  

PubMed Central

Proliferation of mammalian cardiomyocytes stops rapidly after birth and injured hearts do not regenerate adequately. High cyclin-dependent kinase inhibitor (CKI) levels have been observed in cardiomyocytes, but their role in maintaining cardiomyocytes in a post-mitotic state is still unknown. In this report, it was investigated whether CKI knockdown by RNA interference induced cardiomyocyte proliferation. We found that triple transfection with p21Waf1, p27Kip1, and p57Kip2 siRNAs induced both neonatal and adult cardiomyocyte to enter S phase and increased the nuclei/cardiomyocyte ratio; furthermore, a subpopulation of cardiomyocytes progressed beyond karyokynesis, as assessed by the detection of mid-body structures and by straight cardiomyocyte counting. Intriguingly, cardiomyocyte proliferation occurred in the absence of overt DNA damage and aberrant mitotic figures. Finally, CKI knockdown and DNA synthesis reactivation correlated with a dramatic change in adult cardiomyocyte morphology that may be a prerequisite for cell division. In conclusion, CKI expression plays an active role in maintaining cardiomyocyte withdrawal from the cell cycle. PMID:21209082

Di Stefano, Valeria; Giacca, Mauro; Capogrossi, Maurizio C.; Crescenzi, Marco; Martelli, Fabio

2011-01-01

259

Panhistone deacetylase inhibitors inhibit proinflammatory signaling pathways to ameliorate interleukin-18-induced cardiac hypertrophy  

PubMed Central

We investigated the genome-wide consequences of pan-histone deacetylase inhibitors (HDACIs) trichostatin A (TSA) and m-carboxycinnamic acid bis-hydroxamide (CBHA) in the hearts of BALB/c mice eliciting hypertrophy in response to interleukin-18 (IL-18). Both TSA and CBHA profoundly altered cardiac chromatin structure that occurred concomitantly with normalization of IL-18-induced gene expression and amelioration of cardiac hypertrophy. The hearts of mice exposed to IL-18 +/? TSA or CBHA elicited distinct gene expression profiles. Of 184 genes that were differentially regulated by IL-18 and TSA, 33 were regulated in an opposite manner. The hearts of mice treated with IL-18 and/or CBHA elicited 147 differentially expressed genes (DEGs), a third of which were oppositely regulated by IL-18 and CBHA. Ingenuity Pathways and Kyoto Encyclopedia of Genes and Genomes analyses of DEGs showed that IL-18 impinged on TNF-?- and IFN?-specific gene networks relegated to controlling immunity and inflammation, cardiac metabolism and energetics, and cell proliferation and apoptosis. These TNF-?- and IFN?-specific gene networks, extensively connected with PI3K, MAPK, and NF-?B signaling pathways, were oppositely regulated by IL-18 and pan-HDACIs. Evidently, both TSA and CBHA caused a two- to fourfold induction of phosphatase and tensin homolog expression to counteract IL-18-induced proinflammatory signaling and cardiac hypertrophy. PMID:21954451

Majumdar, Gipsy; Rooney, Robert J.; Johnson, I. Maria

2011-01-01

260

The NADPH oxidase inhibitor apocynin induces nitric oxide synthesis via oxidative stress  

SciTech Connect

We have recently shown that apocynin elicits an oxidative stress in N11 mouse glial cells and other cell types. Here we report that apocynin increased the accumulation of nitrite, the stable derivative of nitric oxide (NO), in the extracellular medium of N11 cell cultures, and the NO synthase (NOS) activity in cell lysates. The increased synthesis of NO was associated with increased expression of inducible NOS (iNOS) mRNA, increased nuclear translocation of the redox-sensitive transcription factor NF-{kappa}B and decreased intracellular level of its inhibitor IkB{alpha}. These effects, accompanied by increased production of H{sub 2}O{sub 2}, were very similar to those observed after incubation with bacterial lipopolysaccharide (LPS) and were inhibited by catalase. These results suggest that apocynin, similarly to LPS, induces increased NO synthesis by eliciting a generation of reactive oxygen species (ROS), which in turn causes NF-{kappa}B activation and increased expression of iNOS. Therefore, the increased bioavailability of NO reported in the literature after in vivo or in vitro treatments with apocynin might depend, at least partly, on the drug-elicited induction of iNOS, and not only on the inhibition of NADPH oxidase and the subsequent decreased scavenging of NO by oxidase-derived ROS, as it is often supposed.

Riganti, Chiara [Dipartimento di Genetica, Biologia e Biochimica, Universita di Torino, Via Santena 5/bis, 10126 Torino (Italy)], E-mail: chiara.riganti@unito.it; Costamagna, Costanzo; Doublier, Sophie; Miraglia, Erica; Polimeni, Manuela; Bosia, Amalia; Ghigo, Dario [Dipartimento di Genetica, Biologia e Biochimica, Universita di Torino, Via Santena 5/bis, 10126 Torino (Italy)

2008-05-01

261

Induced sputum-retrieved matrix metalloproteinase 9 and tissue metalloproteinase inhibitor 1 in granulomatous diseases  

PubMed Central

Matrix metalloproteinases (MMPs) capable of degrading various components of connective tissue matrices, and tissue inhibitor metalloproteinases (TIMPs) are considered important in lung parenchymal remodeling and repair processes in pulmonary diseases. Induced sputum (IS) is a reliable noninvasive method to investigate pathogenesis, pathophysiology and treatment of lung disease. This study was designed to determine whether IS-MMP9/TIMP1 levels demonstrate lung parenchymal remodeling in sarcoidosis (SA) and Crohn's disease (CRD) patients. Sputum was induced and processed conventionally in 13 SA patients, 18 CRD patients and 9 controls. Two-hundred cells were counted on Giemsa-stained cytopreps, and T lymphocytes subsets (CD4 = T helper and CD8 = T suppressor cytotoxic cells) were analysed by FACS using monoclonal antibodies.MMP-9 and TIMP-1 were measured using commercial ELISA kits. MMP-9 concentrations, but not those of TIMP-1, were significantly greater in the sputum supernatant in SA and CRD patients compared to controls (P = 0·018 and P = 0·0019, respectively). The molar ratio, MMP-9/TIMP-1, was significantly higher in SA and CRD patients compared to controls (P = 0·008 and P = 0·024, respectively). Gelatinase species having a molecular weight similar to that of MMP-9 were demonstrated by zymographic analysis. MMP-9 levels were highly correlated with the CD4/CD8 ratio and DLCO capacity in SA but less in CRD patients. MMP-9 levels in IS provide a sensitive marker for pulmonary damage. PMID:12390324

Fireman, E; Kraiem, Z; Sade, O; Greif, J; Fireman, Z

2002-01-01

262

CT-2576, an inhibitor of phospholipid signaling, suppresses constitutive and induced expression of human immunodeficiency virus.  

PubMed Central

Viruses such as human immunodeficiency virus (HIV) require cellular activation for expression. Cellular activation in lymphoid cells is associated with augmented accumulation of certain phosphatidic acid (PA) species derived from the hydrolysis of glycan phosphatidylinositol (GPI). This suggests that activation of a phospholipid pathway may play a role in initiation of viral replication. To test this hypothesis, we examined the effect of tat gene expression on the production of cellular PA species, as the Tat protein is essential for HIV expression and has been implicated in activating the expression of multiple host cellular genes. Expression of tat increased the expression of PA. We then tested whether synthetic inhibitors of PA metabolism would inhibit activation of the HIV long terminal repeat by Tat and tumor necrosis factor alpha (TNF-alpha). CT-2576 suppressed both PA generation induced by Tat and HIV long terminal repeat-directed gene expression in response to Tat or TNF-alpha at a posttranscriptional step. CT-2576 also inhibited constitutive as well as TNF-alpha- and interleukin 6-induced expression of HIV p24 antigen in chronically infected U1 cells and in peripheral blood lymphocytes acutely infected with a clinical isolate of HIV. Pharmacological inhibition of synthesis of selected PA species may therefore provide a therapeutic approach to suppression of HIV replication. Images Fig. 1 Fig. 3 Fig. 5 PMID:7761405

Leung, D W; Peterson, P K; Weeks, R; Gekker, G; Chao, C C; Kaplan, A H; Balantac, N; Tompkins, C; Underiner, G E; Bursten, S

1995-01-01

263

The protein synthesis inhibitor anisomycin induces macrophage apoptosis in rabbit atherosclerotic plaques through p38 mitogen-activated protein kinase.  

PubMed

Because macrophages play a major role in atherosclerotic plaque destabilization, selective removal of macrophages represents a promising approach to stabilize plaques. We showed recently that the protein synthesis inhibitor cycloheximide, in contrast to puromycin, selectively depleted macrophages in rabbit atherosclerotic plaques without affecting smooth muscle cells (SMCs). The mechanism of action of these two translation inhibitors is dissimilar and could account for the differential effects on SMC viability. It is not known whether selective depletion of macrophages is confined to cycloheximide or whether it can also be achieved with translation inhibitors that have a similar mechanism of action. Therefore, in the present study, we investigated the effect of anisomycin, a translation inhibitor with a mechanism of action similar to cycloheximide, on macrophage and SMC viability. In vitro, anisomycin induced apoptosis of macrophages in a concentration-dependent manner, whereas SMCs were only affected at higher concentrations. In vivo, anisomycin selectively decreased the macrophage content of rabbit atherosclerotic plaques through apoptosis. The p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190 [4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole] prevented anisomycin-induced macrophage death, without affecting SMC viability. SB202190 decreased anisomycin-induced p38 MAPK phosphorylation, did not alter c-Jun NH(2)-terminal kinase (JNK) phosphorylation, and increased extracellular signal-regulated kinase (ERK) 1/2 phosphorylation. The latter effect was abolished by the mitogen-activated protein kinase kinase 1/2 inhibitor U0126 [1,4-diamino-2,3-dicyano-1,4-bis(2-aminophynyltio)butadiene ethanolate], although the prevention of anisomycin-induced macrophage death by SB202190 remained unchanged. The JNK phosphorylation inhibitor SP600125 did not affect anisomycin-induced macrophage or SMC death. In conclusion, anisomycin selectively decreased the macrophage content in rabbit atherosclerotic plaques, indicating that this effect is not confined to cycloheximide. p38 MAPK, but not ERK1/2 or JNK, plays a major role in anisomycin-induced macrophage death. PMID:19286921

Croons, Valerie; Martinet, Wim; Herman, Arnold G; Timmermans, Jean-Pierre; De Meyer, Guido R Y

2009-06-01

264

Defining the Plant Peroxisomal Proteome: From Arabidopsis to Rice  

PubMed Central

Peroxisomes are small subcellular organelles mediating a multitude of processes in plants. Proteomics studies over the last several years have yielded much needed information on the composition of plant peroxisomes. In this review, the status of peroxisome proteomics studies in Arabidopsis and other plant species and the cumulative advances made through these studies are summarized. A reference Arabidopsis peroxisome proteome is generated, and some unique aspects of Arabidopsis peroxisomes that were uncovered through proteomics studies and hint at unanticipated peroxisomal functions are also highlighted. Knowledge gained from Arabidopsis was utilized to compile a tentative list of peroxisome proteins for the model monocot plant, rice. Differences in the peroxisomal proteome between these two model plants were drawn, and novel facets in rice were expounded upon. Finally, we discuss about the current limitations of experimental proteomics in decoding the complete and dynamic makeup of peroxisomes, and complementary and integrated approaches that would be beneficial to defining the peroxisomal metabolic and regulatory roadmaps. The synteny of genomes in the grass family makes rice an ideal model to study peroxisomes in cereal crops, in which these organelles have received much less attention, with the ultimate goal to improve crop yield. PMID:22645559

Kaur, Navneet; Hu, Jianping

2011-01-01

265

Protein Phosphatase 2A Holoenzyme Is Targeted to Peroxisomes by Piggybacking and Positively Affects Peroxisomal ?-Oxidation.  

PubMed

The eukaryotic, highly conserved serine (Ser)/threonine-specific protein phosphatase 2A (PP2A) functions as a heterotrimeric complex composed of a catalytic (C), scaffolding (A), and regulatory (B) subunit. In Arabidopsis (Arabidopsis thaliana), five, three, and 17 genes encode different C, A, and B subunits, respectively. We previously found that a B subunit, B'?, localized to peroxisomes due to its C-terminal targeting signal Ser-Ser-leucine. This work shows that PP2A C2, C5, andA2 subunits interact and colocalize with B'? in peroxisomes. C and A subunits lack peroxisomal targeting signals, and their peroxisomal import depends on B'? and appears to occur by piggybacking transport. B'? knockout mutants were impaired in peroxisomal ?-oxidation as shown by developmental arrest of seedlings germinated without sucrose, accumulation of eicosenoic acid, and resistance to protoauxins indole-butyric acid and 2,4-dichlorophenoxybutyric acid. All of these observations strongly substantiate that a full PP2A complex is present in peroxisomes and positively affects ?-oxidation of fatty acids and protoauxins. PMID:25489022

Kataya, Amr R A; Heidari, Behzad; Hagen, Lars; Kommedal, Roald; Slupphaug, Geir; Lillo, Cathrine

2015-02-01

266

PAS3, a Saccharomyces cerevisiae gene encoding a peroxisomal integral membrane protein essential for peroxisome biogenesis  

PubMed Central

Saccharomyces cerevisiae pas3-mutants are described which conform the pas-phenotype recently reported for the peroxisomal assembly mutants pas1-1 and pas2 (Erdmann, R., M. Veenhuis, D. Mertens, and W.-H Kunau, 1989, Proc. Natl. Acad. Sci. USA. 86:5419-5423). The isolation of pas3- mutants enabled us to clone the PAS3 gene by functional complementation. DNA sequence analysis revealed a 50.6-kD protein with at least one domain of sufficient length and hydrophobicity to span a lipid bilayer. To verify these predictions antibodies were raised against a truncated portion of the PAS3 coding region overexpressed in E. coli. Pas3p was identified as a 48 kD peroxisomal integral membrane protein. It is shown that a lack of this protein causes the peroxisome- deficient phenotype and the cytosolic mislocalization of peroxisomal matrix enzymes. Based on protease digestion experiments Pas3p is discussed to be anchored in the peroxisomal membrane by its amino- terminus while the bulk of the molecule is exposed to the cytosol. These findings are consistent with the possibility that Pas3p is one component of the peroxisomal import machinery. PMID:1894692

1991-01-01

267

Induction by perfluorinated fatty acids with different carbon chain length of peroxisomal ?-oxidation in the liver of rats  

Microsoft Academic Search

The potency of the induction of peroxisomal ?-oxidation was compared between perfluorinated fatty acids (PFCAs) with different carbon chain lengths in the liver of male and female rats. In male rats, perfluoroheptanoic acid (PFHA) has little effect, although perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) potentially induced the activity. By contrast, PFHA and PFOA did not induce

Naomi Kudo; Naoki Bandai; Erika Suzuki; Masanori Katakura; Yoichi Kawashima

2000-01-01

268

Effect of a neutrophil elastase inhibitor on ventilator-induced lung injury in rats  

PubMed Central

Objective We hypothesized that pretreatment with sivelestat therapy could attenuate ventilator-induced lung injury (VILI) and lung inflammation in a rat model. Methods The neutrophil elastase inhibitor was administered intraperitoneally 30 min before and at the initiation of ventilation. The rats were categorized as (I) sham group; (II) VILI group; (III) sivelestat group; (IV) early sivelestat group. Wet-to-dry weight ratio, bronchoalveolar lavage fluid (BALF) neutrophil and protein, tissue malondialdehyde (MDA) and histologic VILI scores were investigated. Results The ratio of wet-to-dry weight, BALF neutrophil and protein, tissue MDA and VILI scores were significantly increased in the VILI group compared to the sham group [3.85±0.32 vs. 9.05±1.02, P<0.001; (0.89±0.93)×104 vs. (7.67±1.41)×104 cells/mL, P<0.001; 2.34±0.47 vs. 23.01±3.96 mg/mL, P<0.001; 14.43±1.01 vs. 36.56±5.45 nmol/mg protein, P<0.001; 3.78±0.67 vs. 7.00±1.41, P<0.001]. This increase was attenuated in the early sivelestat group compared with the sivelestat group [wet-to-dry ratio: 6.76±2.01 vs. 7.39±0.32, P=0.032; BALF neutrophil: (5.56±1.13)×104 vs. (3.89±1.05)×104 cells/mL, P=0.021; BALF protein: 15.57±2.32 vs. 18.38±2.00 mg/mL, P=0.024; tissue MDA: 29.16±3.01 vs. 26.31±2.58, P=0.049; VILI scores: 6.33±1.41 vs. 5.00±0.50, P=0.024]. Conclusions Pretreatment with a neutrophil elastase inhibitor attenuates VILI in a rat model. PMID:25589960

Kim, Do-Hyung; Chung, Jae Ho; Son, Bong Soo; Kim, Yeon Ji

2014-01-01

269

Human MX2 is an interferon-induced post-entry inhibitor of HIV-1 infection.  

PubMed

Animal cells harbour multiple innate effector mechanisms that inhibit virus replication. For the pathogenic retrovirus human immunodeficiency virus type 1 (HIV-1), these include widely expressed restriction factors, such as APOBEC3 proteins, TRIM5-?, BST2 (refs 4, 5) and SAMHD1 (refs 6, 7), as well as additional factors that are stimulated by type 1 interferon (IFN). Here we use both ectopic expression and gene-silencing experiments to define the human dynamin-like, IFN-induced myxovirus resistance 2 (MX2, also known as MXB) protein as a potent inhibitor of HIV-1 infection and as a key effector of IFN-?-mediated resistance to HIV-1 infection. MX2 suppresses infection by all HIV-1 strains tested, has equivalent or reduced effects on divergent simian immunodeficiency viruses, and does not inhibit other retroviruses such as murine leukaemia virus. The Capsid region of the viral Gag protein dictates susceptibility to MX2, and the block to infection occurs at a late post-entry step, with both the nuclear accumulation and chromosomal integration of nascent viral complementary DNA suppressed. Finally, human MX1 (also known as MXA), a closely related protein that has long been recognized as a broadly acting inhibitor of RNA and DNA viruses, including the orthomyxovirus influenza A virus, does not affect HIV-1, whereas MX2 is ineffective against influenza virus. MX2 is therefore a cell-autonomous, anti-HIV-1 resistance factor whose purposeful mobilization may represent a new therapeutic approach for the treatment of HIV/AIDS. PMID:24048477

Goujon, Caroline; Moncorgé, Olivier; Bauby, Hélène; Doyle, Tomas; Ward, Christopher C; Schaller, Torsten; Hué, Stéphane; Barclay, Wendy S; Schulz, Reiner; Malim, Michael H

2013-10-24

270

Topoisomerase I inhibitor, camptothecin, induces apoptogenic signaling in human embryonic stem cells.  

PubMed

Embryonic stem cells (ESCs) need to maintain their genomic integrity in response to DNA damage to safeguard the integrity of the organism. DNA double strand breaks (DSBs) are one of the most lethal forms of DNA damage and, if not repaired correctly, they can lead to cell death, genomic instability and cancer. How human ESCs (hESCs) maintain genomic integrity in response to agents that cause DSBs is relatively unclear. In the present study we aim to determine the hESC response to the DSB inducing agent camptothecin (CPT). We find that hESCs are hypersensitive to CPT, as evidenced by high levels of apoptosis. CPT treatment leads to DNA-damage sensor kinase (ATM and DNA-PKcs) phosphorylation on serine 1981 and serine 2056, respectively. Activation of ATM and DNA-PKcs was followed by histone H2AX phosphorylation on Ser 139, a sensitive reporter of DNA damage. Nuclear accumulation and ATM-dependent phosphorylation of p53 on serine 15 were also observed. Remarkably, hESC viability was further decreased when ATM or DNA-PKcs kinase activity was impaired by the use of specific inhibitors. The hypersensitivity to CPT treatment was markedly reduced by blocking p53 translocation to mitochondria with pifithrin-?. Importantly, programmed cell death was achieved in the absence of the cyclin dependent kinase inhibitor, p21(Waf1), a bona fide p53 target gene. Conversely, differentiated hESCs were no longer highly sensitive to CPT. This attenuated apoptotic response was accompanied by changes in cell cycle profile and by the presence of p21(Waf1). The results presented here suggest that p53 has a key involvement in preventing the propagation of damaged hESCs when genome is threatened. As a whole, our findings support the concept that the phenomenon of apoptosis is a prominent player in normal embryonic development. PMID:24380814

García, Carolina Paola; Videla Richardson, Guillermo Agustín; Romorini, Leonardo; Miriuka, Santiago Gabriel; Sevlever, Gustavo Emilio; Scassa, María Elida

2014-03-01

271

FoxM1 knockdown sensitizes human cancer cells to proteasome inhibitor-induced apoptosis but not to autophagy  

PubMed Central

Apoptosis has been widely accepted as the primary mechanism of drug-induced cell death. Recently, a second type of cell death pathway has been demonstrated: autophagy, also called programmed type II cell death. Autophagy is a highly regulated process, by which selected components of a cell are degraded. It primarily functions as a cell survival mechanism under stress. However, persistent stress can also promote extensive autophagy leading to cell death. Forkhead Box M1 (FoxM1), an oncogenic transcription factor that is abundantly expressed in a wide range of human cancers. Here, we evaluated the role of FoxM1 in sensitivity of human cancer cells to proteasome inhibitor-induced apoptosis and autophagy. We found that FoxM1 knockdown sensitized the human cancer cells to apoptotic cell death induced by proteasome inhibitors, such as, MG132, bortezomib and thiostrepton, while it did not affect the levels of autophagy following treatment with these drugs. PMID:21941087

Pandit, Bulbul

2011-01-01

272

Statins meditate anti-atherosclerotic action in smooth muscle cells by peroxisome proliferator-activated receptor-? activation.  

PubMed

The peroxisome proliferator-activated receptor-? (PPAR?) is an important regulator of lipid and glucose metabolism, and its activation is reported to suppress the progression of atherosclerosis. We have reported that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) activate PPAR? in macrophages. However, it is not yet known whether statins activate PPAR? in other vascular cells. In the present study, we investigated whether statins activate PPAR? in smooth muscle cells (SMCs) and endothelial cells (ECs) and thus mediate anti-atherosclerotic effects. Human aortic SMCs (HASMCs) and human umbilical vein ECs (HUVECs) were used in this study. Fluvastatin and pitavastatin activated PPAR? in HASMCs, but not in HUVECs. Statins induced cyclooxygenase-2 (COX-2) expression in HASMCs, but not in HUVECs. Moreover, treatment with COX-2-siRNA abrogated statin-mediated PPAR? activation in HASMCs. Statins suppressed migration and proliferation of HASMCs, and inhibited lipopolysaccharide-induced expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-? (TNF-?) in HASMCs. These effects of statins were abrogated by treatment with PPAR?-siRNA. Treatment with statins suppressed atherosclerotic lesion formation in Apoe(-/-) mice. In addition, transcriptional activity of PPAR? and CD36 expression were increased, and the expression of MCP-1 and TNF-? was decreased, in the aorta of statin-treated Apoe(-/-) mice. In conclusion, statins mediate anti-atherogenic effects through PPAR? activation in SMCs. These effects of statins on SMCs may be beneficial for the prevention of atherosclerosis. PMID:25529449

Fukuda, Kazuki; Matsumura, Takeshi; Senokuchi, Takafumi; Ishii, Norio; Kinoshita, Hiroyuki; Yamada, Sarie; Murakami, Saiko; Nakao, Saya; Motoshima, Hiroyuki; Kondo, Tatsuya; Kukidome, Daisuke; Kawasaki, Shuji; Kawada, Teruo; Nishikawa, Takeshi; Araki, Eiichi

2015-01-30

273

Attenuation of doxorubicin-induced cardiotoxicity by mdivi-1: a mitochondrial division/mitophagy inhibitor.  

PubMed

Doxorubicin is one of the most effective anti-cancer agents. However, its use is associated with adverse cardiac effects, including cardiomyopathy and progressive heart failure. Given the multiple beneficial effects of the mitochondrial division inhibitor (mdivi-1) in a variety of pathological conditions including heart failure and ischaemia and reperfusion injury, we investigated the effects of mdivi-1 on doxorubicin-induced cardiac dysfunction in naïve and stressed conditions using Langendorff perfused heart models and a model of oxidative stress was used to assess the effects of drug treatments on the mitochondrial depolarisation and hypercontracture of cardiac myocytes. Western blot analysis was used to measure the levels of p-Akt and p-Erk 1/2 and flow cytometry analysis was used to measure the levels p-Drp1 and p-p53 upon drug treatment. The HL60 leukaemia cell line was used to evaluate the effects of pharmacological inhibition of mitochondrial division on the cytotoxicity of doxorubicin in a cancer cell line. Doxorubicin caused a significant impairment of cardiac function and increased the infarct size to risk ratio in both naïve conditions and during ischaemia/reperfusion injury. Interestingly, co-treatment of doxorubicin with mdivi-1 attenuated these detrimental effects of doxorubicin. Doxorubicin also caused a reduction in the time taken to depolarisation and hypercontracture of cardiac myocytes, which were reversed with mdivi-1. Finally, doxorubicin caused a significant elevation in the levels of signalling proteins p-Akt, p-Erk 1/2, p-Drp1 and p-p53. Co-incubation of mdivi-1 with doxorubicin did not reduce the cytotoxicity of doxorubicin against HL-60 cells. These data suggest that the inhibition of mitochondrial fission protects the heart against doxorubicin-induced cardiac injury and identify mitochondrial fission as a new therapeutic target in ameliorating doxorubicin-induced cardiotoxicity without affecting its anti-cancer properties. PMID:24147064

Gharanei, Mayel; Hussain, Afthab; Janneh, Omar; Maddock, Helen

2013-01-01

274

Attenuation of Doxorubicin-Induced Cardiotoxicity by mdivi-1: A Mitochondrial Division/Mitophagy Inhibitor  

PubMed Central

Doxorubicin is one of the most effective anti-cancer agents. However, its use is associated with adverse cardiac effects, including cardiomyopathy and progressive heart failure. Given the multiple beneficial effects of the mitochondrial division inhibitor (mdivi-1) in a variety of pathological conditions including heart failure and ischaemia and reperfusion injury, we investigated the effects of mdivi-1 on doxorubicin-induced cardiac dysfunction in naïve and stressed conditions using Langendorff perfused heart models and a model of oxidative stress was used to assess the effects of drug treatments on the mitochondrial depolarisation and hypercontracture of cardiac myocytes. Western blot analysis was used to measure the levels of p-Akt and p-Erk 1/2 and flow cytometry analysis was used to measure the levels p-Drp1 and p-p53 upon drug treatment. The HL60 leukaemia cell line was used to evaluate the effects of pharmacological inhibition of mitochondrial division on the cytotoxicity of doxorubicin in a cancer cell line. Doxorubicin caused a significant impairment of cardiac function and increased the infarct size to risk ratio in both naïve conditions and during ischaemia/reperfusion injury. Interestingly, co-treatment of doxorubicin with mdivi-1 attenuated these detrimental effects of doxorubicin. Doxorubicin also caused a reduction in the time taken to depolarisation and hypercontracture of cardiac myocytes, which were reversed with mdivi-1. Finally, doxorubicin caused a significant elevation in the levels of signalling proteins p-Akt, p-Erk 1/2, p-Drp1 and p-p53. Co-incubation of mdivi-1 with doxorubicin did not reduce the cytotoxicity of doxorubicin against HL-60 cells. These data suggest that the inhibition of mitochondrial fission protects the heart against doxorubicin-induced cardiac injury and identify mitochondrial fission as a new therapeutic target in ameliorating doxorubicin-induced cardiotoxicity without affecting its anti-cancer properties. PMID:24147064

Gharanei, Mayel; Hussain, Afthab; Janneh, Omar; Maddock, Helen

2013-01-01

275

CDK-4 inhibitor P276 sensitizes Pancreatic Cancer cells to Gemcitabine induced Apoptosis  

PubMed Central

Despite advances in molecular pathogenesis, pancreatic cancer remains a major unsolved health problem. It is a rapidly invasive, metastatic tumor that is resistant to standard therapies. The phosphatidylinositol-3-kinase (PI3K)/Akt and mammalian target of rapamycin (mTOR) signaling pathways are frequently dysregulated in pancreatic cancer. Gemcitabine (Gem) is the mainstay treatment for metastatic pancreatic cancer. P276 is a novel CDK inhibitor that induces G2/M arrest and inhibits tumor growth in vivo models. Here, we determined that P276 sensitizes pancreatic cancer cells to Gem induced apoptosis, a mechanism mediated through inhibition of Akt-mTOR signaling. In vitro, the combination of P276 and Gem resulted in a dose- and time-dependent inhibition of proliferation and colony formation of pancreatic cancer cells but not with normal pancreatic ductal cells. This combination also induced apoptosis, as seen by activated caspase 3 and increased Bax/Bcl2 ratio. Gene profiling studies demonstrated that this combination downregulated Akt-mTOR signaling pathway, which was confirmed by western blot analyses. There was also a downregulation of vascular endothelial growth factor (VEGF) and interleukin-8 expression suggesting effects on angiogenesis pathway. In vivo, intraperitoneal administration of the P276-Gem combination significantly suppressed the growth of pancreatic cancer tumor xenografts. There was a reduction in CD31 positive blood vessels, and reduced VEGF expression, again suggesting an effect on angiogenesis. Taken together, these data suggest that P276-Gem combination is a novel potent therapeutic agent that can target the Akt-mTOR signaling pathway to inhibit both tumor growth and angiogenesis. PMID:22532602

Subramaniam, Dharmalingam; Periyasamy, Giridharan; Ponnurangam, Sivapriya; Chakrabarti, Debarshi; Sugumar, Aravind; Padigaru, Muralidhara; Weir, Scott J.; Balakrishnan, Arun; Sharma, Somesh; Anant, Shrikant

2012-01-01

276

HDAC inhibitors induce tumor-cell-selective pro-apoptotic transcriptional responses  

PubMed Central

The identification of recurrent somatic mutations in genes encoding epigenetic enzymes has provided a strong rationale for the development of compounds that target the epigenome for the treatment of cancer. This notion is supported by biochemical studies demonstrating aberrant recruitment of epigenetic enzymes such as histone deacetylases (HDACs) and histone methyltransferases to promoter regions through association with oncogenic fusion proteins such as PML-RAR? and AML1-ETO. HDAC inhibitors (HDACi) are potent inducers of tumor cell apoptosis; however, it remains unclear why tumor cells are more sensitive to HDACi-induced cell death than normal cells. Herein, we assessed the biological and molecular responses of isogenic normal and transformed cells to the FDA-approved HDACi vorinostat and romidepsin. Both HDACi selectively killed cells of diverse tissue origin that had been transformed through the serial introduction of different oncogenes. Time-course microarray expression profiling revealed that normal and transformed cells transcriptionally responded to vorinostat treatment. Over 4200 genes responded differently to vorinostat in normal and transformed cells and gene ontology and pathway analyses identified a tumor-cell-selective pro-apoptotic gene-expression signature that consisted of BCL2 family genes. In particular, HDACi induced tumor-cell-selective upregulation of the pro-apoptotic gene BMF and downregulation of the pro-survival gene BCL2A1 encoding BFL-1. Maintenance of BFL-1 levels in transformed cells through forced expression conferred vorinostat resistance, indicating that specific and selective engagement of the intrinsic apoptotic pathway underlies the tumor-cell-selective apoptotic activities of these agents. The ability of HDACi to affect the growth and survival of tumor cells whilst leaving normal cells relatively unharmed is fundamental to their successful clinical application. This study provides new insight into the transcriptional effects of HDACi in human donor-matched normal and transformed cells, and implicates specific molecules and pathways in the tumor-selective cytotoxic activity of these compounds. PMID:23449455

Bolden, J E; Shi, W; Jankowski, K; Kan, C-Y; Cluse, L; Martin, B P; MacKenzie, K L; Smyth, G K; Johnstone, R W

2013-01-01

277

Direct thrombin inhibitors, but not the direct factor Xa inhibitor rivaroxaban, increase tissue factor-induced hypercoagulability in vitro and in vivo  

PubMed Central

Background Increased hypercoagulability has been reported with low doses of direct thrombin inhibitors but not with direct factor Xa inhibitors. Objectives To compare the effects of rivaroxaban with those of melagatran and dabigatran on thrombin generation (TG) and tissue factor-induced hypercoagulability and to explore the possible involvement of the thrombin–thrombomodulin/activated protein C system. Methods In normal human plasma and in protein C-deficient plasma, TG was investigated in vitro in the presence and absence of recombinant human soluble thrombomodulin (rhs-TM). TG was determined by calibrated automated thrombography and an ELISA for prothrombin fragments 1+2 (F1+2). In an in vivo rat model, hypercoagulability was induced by tissue factor; levels of thrombin–antithrombin (TAT) and fibrinogen and the platelet count were determined. Results Rivaroxaban inhibited TG in a concentration-dependent manner. In the absence of rhs-TM, melagatran and dabigatran also inhibited TG concentration dependently. However, in the presence of rhs-TM, lower concentrations of melagatran (119–474 nmol L–1) and dabigatran (68–545 nmol L?1) enhanced endogenous thrombin potential, peak TG, and F1+2 formation in normal plasma but not in protein C-deficient plasma. In vivo, rivaroxaban dose-dependently inhibited TAT generation, whereas melagatran showed a paradoxical effect, with an increase in TAT and a small decrease in fibrinogen and platelet count at lower doses. Conclusion Low concentrations of the direct thrombin inhibitors melagatran and dabigatran enhanced TG and hypercoagulability, possibly via inhibition of the protein C system. In contrast, rivaroxaban reduced TG and hypercoagulability under all conditions studied, suggesting that it does not suppress this negative-feedback system. PMID:24766850

Perzborn, E; Heitmeier, S; Buetehorn, U; Laux, V

2014-01-01

278

Fatty Acid Synthase Inhibitors Induce Apoptosis in Non-Tumorigenic Melan-A Cells Associated with Inhibition of Mitochondrial Respiration  

PubMed Central

The metabolic enzyme fatty acid synthase (FASN) is responsible for the endogenous synthesis of palmitate, a saturated long-chain fatty acid. In contrast to most normal tissues, a variety of human cancers overexpress FASN. One such cancer is cutaneous melanoma, in which the level of FASN expression is associated with tumor invasion and poor prognosis. We previously reported that two FASN inhibitors, cerulenin and orlistat, induce apoptosis in B16-F10 mouse melanoma cells via the intrinsic apoptosis pathway. Here, we investigated the effects of these inhibitors on non-tumorigenic melan-a cells. Cerulenin and orlistat treatments were found to induce apoptosis and decrease cell proliferation, in addition to inducing the release of mitochondrial cytochrome c and activating caspases-9 and -3. Transfection with FASN siRNA did not result in apoptosis. Mass spectrometry analysis demonstrated that treatment with the FASN inhibitors did not alter either the mitochondrial free fatty acid content or composition. This result suggests that cerulenin- and orlistat-induced apoptosis events are independent of FASN inhibition. Analysis of the energy-linked functions of melan-a mitochondria demonstrated the inhibition of respiration, followed by a significant decrease in mitochondrial membrane potential (??m) and the stimulation of superoxide anion generation. The inhibition of NADH-linked substrate oxidation was approximately 40% and 61% for cerulenin and orlistat treatments, respectively, and the inhibition of succinate oxidation was approximately 46% and 52%, respectively. In contrast, no significant inhibition occurred when respiration was supported by the complex IV substrate N,N,N?,N?-tetramethyl-p-phenylenediamine (TMPD). The protection conferred by the free radical scavenger N-acetyl-cysteine indicates that the FASN inhibitors induced apoptosis through an oxidative stress-associated mechanism. In combination, the present results demonstrate that cerulenin and orlistat induce apoptosis in non-tumorigenic cells via mitochondrial dysfunction, independent of FASN inhibition. PMID:24964211

Rossato, Franco A.; Zecchin, Karina G.; La Guardia, Paolo G.; Ortega, Rose M.; Alberici, Luciane C.; Costa, Rute A. P.; Catharino, Rodrigo R.; Graner, Edgard; Castilho, Roger F.; Vercesi, Aníbal E.

2014-01-01

279

Modulation of curcumin-induced Akt phosphorylation and apoptosis by PI3K inhibitor in MCF-7 cells  

SciTech Connect

Curcumin has been shown to induce apoptosis in various malignant cancer cell lines. One mechanism of curcumin-induced apoptosis is through the PI3K/Akt signaling pathway. Akt, also known as protein kinase B (PKB), is a member of the family of phosphatidylinositol 3-OH-kinase regulated Ser/Thr kinases. The active Akt regulates cell survival and proliferation; and inhibits apoptosis. In this study we found that curcumin induces apoptotic cell death in MCF-7 cells, as assessed by MTT assay, DNA ladder formation, PARP cleavage, p53 and Bax induction. At apoptotic inducing concentration, curcumin induces a dramatic Akt phosphorylation, accompanied by an increased phosphorylation of glycogen synthase kinase 3{beta} (GSK3{beta}), which has been considered to be a pro-growth signaling molecule. Combining curcumin with PI3K inhibitor, LY290042, synergizes the apoptotic effect of curcumin. The inhibitor LY290042 was capable of attenuating curcumin-induced Akt phosphorylation and activation of GSK3{beta}. All together, our data suggest that blocking the PI3K/Akt survival pathway sensitizes the curcumin-induced apoptosis in MCF-7 cells.

Kizhakkayil, Jaleel; Thayyullathil, Faisal; Chathoth, Shahanas; Hago, Abdulkader; Patel, Mahendra [Cell Signaling Laboratory, Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain (United Arab Emirates)] [Cell Signaling Laboratory, Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain (United Arab Emirates); Galadari, Sehamuddin, E-mail: sehamuddin@uaeu.ac.ae [Cell Signaling Laboratory, Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain (United Arab Emirates)] [Cell Signaling Laboratory, Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain (United Arab Emirates)

2010-04-09

280

Purpurin as a specific inhibitor of spermidine-induced autoactivation of the protease plasma hyaluronan-binding protein.  

PubMed

Plasma hyaluronan-binding protein (PHBP), a serine protease that can activate coagulation factor VII and prourokinase, circulates as a single-chain form (pro-PHBP), and is autoproteolytically converted to an active two-chain form with the aid of an effector such as spermidine and heparin. In this study, we screened natural sources for inhibitors of spermidine-induced pro-PHBP autoactivation. As an active agent, we purified bikaverin from a culture of a fungus. Bikaverin inhibited spermidine-induced autoactivation with an IC(50) of 0.45 microM, while it also inhibited the active form of PHBP (IC(50)=0.8 microM). Additional screening of related compounds led to the identification of purpurin, a plant anthraquinone, as a specific inhibitor: IC(50)=6.6 microM for spermidine-induced autoactivation; no inhibition of heparin-induced autoactivation and active PHBP. Alizarin and emodin, which structurally differed from purpurin in the position or the number of the hydroxyl groups, were less active and nonspecific. Thus, the position and/or the number of the hydroxyl group affect both the potency and selectivity of the anthraquinone inhibitors. PMID:20686243

Nishimura, Naoko; Takai, Masayuki; Yamamoto, Eisaku; Hasumi, Keiji

2010-01-01

281

A comparative study of the aneugenic and polyploidy-inducing effects of fisetin and two model Aurora kinase inhibitors.  

PubMed

Fisetin, a plant flavonol commonly found in fruits, nuts and vegetables, is frequently added to nutritional supplements due to its reported cardioprotective, anti-carcinogenic and antioxidant properties. Earlier reports from our laboratory and others have indicated that fisetin has both aneugenic and clastogenic properties in cultured cells. More recently, fisetin has also been reported to target Aurora B kinase, a Ser/Thr kinase involved in ensuring proper microtubule attachment at the spindle assembly checkpoint, and an enzyme that is overexpressed in several types of cancer. Here we have further characterized the chromosome damage caused by fisetin and compared it with that induced by two known Aurora kinase inhibitors, VX-680 and ZM-447439, in cultured TK6 cells using the micronucleus assay with CREST staining as well as a flow cytometry-based assay that measures multiple types of numerical chromosomal aberrations. The three compounds were highly effective in inducing aneuploidy and polyploidy as evidenced by increases in kinetochore-positive micronuclei, hyperdiploidy, and polyploidy. With fisetin, however, the latter two effects were most significantly observed only after cells were allowed to overcome a cell cycle delay, and occurred at higher concentrations than those induced by the other Aurora kinase inhibitors. Modest increases in kinetochore-negative micronuclei were also seen with the model Aurora kinase inhibitors. These results indicate that fisetin induces multiple types of chromosome abnormalities in human cells, and indicate a need for a thorough investigation of fisetin-augmented dietary supplements. PMID:24680981

Gollapudi, P; Hasegawa, L S; Eastmond, D A

2014-06-01

282

Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells induced by hybrid-compound histone deacetylase inhibitor  

SciTech Connect

Highlights: •Novel histone deacetylase inhibitor Ky-2, remarkably inhibits myeloma cell growth. •Ky-2 demonstrates no cytotoxicity against normal lymphocytic cells. •Ky-2 induces cell cycle arrest through the cell cycle-associated proteins. •Ky-2 induces Bcl-2-inhibitable apoptosis through a caspase-dependent cascade. -- Abstract: Objectives: Histone deacetylase (HDAC) inhibitors are new therapeutic agents, used to treat various types of malignant cancers. In the present study, we investigated the effects of Ky-2, a hybrid-compound HDAC inhibitor, on the growth of mouse myeloma cells. Materials and methods: Myeloma cells, HS-72, P3U1, and mouse normal cells were used in this study. Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle regulatory and the apoptosis associated proteins were examined by Western blot analysis. Hoechst’s staining was used to detect apoptotic cells. Results: Our findings showed that Ky-2 decreased the levels of HDACs, while it enhanced acetylation of histone H3. Myeloma cell proliferation was inhibited by Ky-2 treatment. Interestingly, Ky-2 had no cytotoxic effects on mouse normal cells. Ky-2 treatment induced G1-phase cell cycle arrest and accumulation of a sub-G1 phase population, while Western blotting analysis revealed that expressions of the cell cycle-associated proteins were up-regulated. Also, Ky-2 enhanced the cleavage of caspase-9 and -3 in myeloma cells, followed by DNA fragmentation. In addition, Ky-2 was not found to induce apoptosis in bcl-2 overexpressing myeloma cells. Conclusion: These findings suggest that Ky-2 induces apoptosis via a caspase-dependent cascade and Bcl-2-inhibitable mechanism in myeloma cells.

Fujii, Seiko [Division of Infections and Molecular Biology, Kyushu Dental University (Japan) [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Okinaga, Toshinori; Ariyoshi, Wataru [Division of Infections and Molecular Biology, Kyushu Dental University (Japan) [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Oral Biology Research Center, Kyushu Dental University (Japan); Takahashi, Osamu; Iwanaga, Kenjiro [Division of Maxillofacial Surgery, Kyushu Dental University (Japan)] [Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Nishino, Norikazu [Oral Biology Research Center, Kyushu Dental University (Japan)] [Oral Biology Research Center, Kyushu Dental University (Japan); Tominaga, Kazuhiro [Division of Maxillofacial Surgery, Kyushu Dental University (Japan)] [Division of Maxillofacial Surgery, Kyushu Dental University (Japan); Nishihara, Tatsuji, E-mail: tatsujin@kyu-dent.ac.jp [Division of Infections and Molecular Biology, Kyushu Dental University (Japan) [Division of Infections and Molecular Biology, Kyushu Dental University (Japan); Oral Biology Research Center, Kyushu Dental University (Japan)

2013-05-10

283

Histone deacetylase inhibitors are potent inducers of gene expression in latent EBV and sensitize lymphoma cells to nucleoside antiviral agents.  

PubMed

Induction of EBV lytic-phase gene expression, combined with exposure to an antiherpes viral drug, represents a promising targeted therapeutic approach to EBV-associated lymphomas. Short-chain fatty acids or certain chemotherapeutics have been used to induce EBV lytic-phase gene expression in cultured cells and mouse models, but these studies generally have not translated into clinical application. The recent success of a clinical trial with the pan-histone deacetylase (pan-HDAC) inhibitor arginine butyrate and the antiherpes viral drug ganciclovir in the treatment of EBV lymphomas prompted us to investigate the potential of several HDAC inhibitors, including some new, highly potent compounds, to sensitize EBV(+) human lymphoma cells to antiviral agents in vitro. Our study included short-chain fatty acids (sodium butyrate and valproic acid); hydroxamic acids (oxamflatin, Scriptaid, suberoyl anilide hydroxamic acid, panobinostat [LBH589], and belinostat [PXD101]); the benzamide MS275; the cyclic tetrapeptide apicidin; and the recently discovered HDAC inhibitor largazole. With the exception of suberoyl anilide hydroxamic acid and PXD101, all of the other HDAC inhibitors effectively sensitized EBV(+) lymphoma cells to ganciclovir. LBH589, MS275, and largazole were effective at nanomolar concentrations and were 10(4) to 10(5) times more potent than butyrate. The effectiveness and potency of these HDAC inhibitors make them potentially applicable as sensitizers to antivirals for the treatment of EBV-associated lymphomas. PMID:22160379

Ghosh, Sajal K; Perrine, Susan P; Williams, Robert M; Faller, Douglas V

2012-01-26

284

OCTN3 is a mammalian peroxisomal membrane carnitine transporter  

SciTech Connect

Carnitine is a zwitterion essential for the {beta}-oxidation of fatty acids. The role of the carnitine system is to maintain homeostasis in the acyl-CoA pools of the cell, keeping the acyl-CoA/CoA pool constant even under conditions of very high acyl-CoA turnover, thereby providing cells with a critical source of free CoA. Carnitine derivatives can be moved across intracellular barriers providing a shuttle mechanism between mitochondria, peroxisomes, and microsomes. We now demonstrate expression and colocalization of mOctn3, the intermediate-affinity carnitine transporter (K {sub m} 20 {mu}M), and catalase in murine liver peroxisomes by TEM using immunogold labelled anti-mOctn3 and anti-catalase antibodies. We further demonstrate expression of hOCTN3 in control human cultured skin fibroblasts both by Western blotting and immunostaining analysis using our specific anti-mOctn3 antibody. In contrast with two peroxisomal biogenesis disorders, we show reduced expression of hOCTN3 in human PEX 1 deficient Zellweger fibroblasts in which the uptake of peroxisomal matrix enzymes is impaired but the biosynthesis of peroxisomal membrane proteins is normal, versus a complete absence of hOCTN3 in human PEX 19 deficient Zellweger fibroblasts in which both the uptake of peroxisomal matrix enzymes as well as peroxisomal membranes are deficient. This supports the localization of hOCTN3 to the peroxisomal membrane. Given the impermeability of the peroxisomal membrane and the key role of carnitine in the transport of different chain-shortened products out of peroxisomes, there appears to be a critical need for the intermediate-affinity carnitine/organic cation transporter, OCTN3, on peroxisomal membranes now shown to be expressed in both human and murine peroxisomes. This Octn3 localization is in keeping with the essential role of carnitine in peroxisomal lipid metabolism.

Lamhonwah, Anne-Marie [Division of Neurology, Department of Pediatrics, Hospital for Sick Children, Toronto (Canada); Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ont., M5G 1X8 (Canada); Ackerley, Cameron A. [Department of Pathology, Hospital for Sick Children, Toronto (Canada); Tilups, Aina [Department of Pathology, Hospital for Sick Children, Toronto (Canada); Edwards, Vernon D. [Department of Pathology, Hospital for Sick Children, Toronto (Canada); Wanders, Ronald J. [Department of Pediatrics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Tein, Ingrid [Division of Neurology, Department of Pediatrics, Hospital for Sick Children, Toronto (Canada) and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ont., M5G 1X8 (Canada)]. E-mail: ingrid.tein@sickkids.ca

2005-12-30

285

Alterations on the growth and ultrastructure of Leishmania chagasi induced by squalene synthase inhibitors.  

PubMed

Leishmaniasis is an important disease in widely dispersed regions of the world. In South America, visceral leishmaniasis (VL) is mainly caused by Leishmania chagasi. The morbidity associated with the infection is high, and death may occur in some untreated patients. Treatment has been based upon pentavalent antimonial drugs for more than half a century and problems, including development of resistance to antimonials and lack of efficacy against VL/HIV co-infections, have emphasized the need for new drugs. Squalene synthase (SQS) is an essential enzyme for the biosynthesis of protozoal sterol molecules. In this work, nineteen synthetic quinuclidines, potentially inhibitors of SQS, were tested against promastigote forms of L. chagasi and the IC50 values of the compounds were determined. The most active compounds had IC50 values of around 30 nM and induced complete growth arrest and cell lysis at sub-micromolar concentrations. We analyzed the morphological structure of the parasites treated with these compounds by transmission electron microscopy of thin sections. Treated parasites showed significant ultrastructural changes, which varied from discrete alterations to total destruction of the cells, depending on the drug concentration and the time of incubation. One important change observed was a typical swelling of the unique and highly branched mitochondrion, where the inner membrane lost its organization. There was an increase in the number of autophagosomal structures. Changes in the organization of the nuclear chromatin and alterations in the flagellar pocket and flagellar membrane were also observed. PMID:17367936

Granthon, Ana Claudia; Braga, Marina V; Rodrigues, Juliany C F; Cammerer, Simon; Lorente, Silvia Orenes; Gilbert, Ian H; Urbina, Julio A; de Souza, Wanderley

2007-05-15

286

Cystathionine-gamma-lyase inhibitor attenuates acute lung injury induced by acute pancreatitis in rats  

PubMed Central

Introduction Acute pancreatitis (AP) is known to induce injuries to extrapancreatic organs. Because respiratory dysfunction is the main cause of death in patients with severe AP, acute pancreatitis-associated lung injury (APALI) is a great challenge for clinicians. This study aimed to investigate the potential role of hydrogen sulfide (H2S) in the pathogenesis of APALI. Material and methods Fifty-four SD rats were randomly divided into three groups: the AP group of rats that received injection of sodium deoxycholate into the common bile duct, the control group that underwent a sham operation, and the treatment group made by intraperitoneal injection of propargylglycine (PAG), an inhibitor of cystathionine-?-lyase (CSE), into rats with AP. Histopathology of the lung was examined and the expression of CSE and TNF-? mRNA in lung tissue was detected by real-time polymerase chain reaction. The H2S level in the serum was detected spectrophotometrically. Results The serum concentration of H2S and CSE and TNF-? expression in the lung were increased in AP rats modeled after 3 h and 6 h than in control rats (p < 0.05). Intraperitoneal injection of PAG could reduce the serum concentration of H2S, reduce CSE and TNF-? expression, and alleviate the lung pathology (p < 0.05). Conclusions Taken together, our findings suggest that the H2S/CSE system is crucially involved in the pathological process of APALI and represents a novel target for the therapy of APALI. PMID:25276170

Qu, Zhen; Wu, Bao-Qiang; Duan, Yun-Fei; Sun, Zhen-Di; Luo, Guang-Hua

2014-01-01

287

Protease Inhibitor Reduces Airway Response and Underlying Inflammation in Cockroach Allergen-Induced Murine Model.  

PubMed

Protease(s) enhances airway inflammation and allergic cascade. In the present study, effect of a serine protease inhibitor was evaluated in mouse model of airway disease. Mice were sensitized with cockroach extract (CE) or Per a 10 and treated with 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF) 1 h before or after challenge to measure airway response. Mice were euthanized to collect bronchoalveolar lavage fluid (BALF), blood, and lung to evaluate inflammation. AEBSF treatment significantly reduced the AHR in allergen-challenged mice in dose-dependent manner (p???0.01). IgE (p???0.05) and Th2 cytokines (p???0.05) were significantly reduced in treated mice. AEBSF treatment lowered total cell (p???0.05), eosinophil (p???0.05), and neutrophil (p???0.05) in BALF and lung tissue. Oxidative stress parameters were impaired on treatment in allergen-challenged mice (p???0.05). AEBSF had therapeutic effect in allergen-induced airway resistance and underling inflammation and had potential for combination or as add-on therapy for respiratory diseases. PMID:25052477

Saw, Sanjay; Arora, Naveen

2014-07-23

288

Aromatase inhibitor-induced modulation of breast density: clinical and genetic effects  

PubMed Central

Background: Change in breast density may predict outcome of women receiving adjuvant hormone therapy for breast cancer. We performed a prospective clinical trial to evaluate the impact of inherited variants in genes involved in oestrogen metabolism and signalling on change in mammographic percent density (MPD) with aromatase inhibitor (AI) therapy. Methods: Postmenopausal women with breast cancer who were initiating adjuvant AI therapy were enrolled onto a multicentre, randomised clinical trial of exemestane vs letrozole, designed to identify associations between AI-induced change in MPD and single-nucleotide polymorphisms in candidate genes. Subjects underwent unilateral craniocaudal mammography before and following 24 months of treatment. Results: Of the 503 enrolled subjects, 259 had both paired mammograms at baseline and following 24 months of treatment and evaluable DNA. We observed a statistically significant decrease in mean MPD from 17.1 to 15.1% (P<0.001), more pronounced in women with baseline MPD ?20%. No AI-specific difference in change in MPD was identified. No significant associations between change in MPD and inherited genetic variants were observed. Conclusion: Subjects with higher baseline MPD had a greater average decrease in MPD with AI therapy. There does not appear to be a substantial effect of inherited variants in biologically selected candidate genes. PMID:24084768

Henry, N L; Chan, H-P; Dantzer, J; Goswami, C P; Li, L; Skaar, T C; Rae, J M; Desta, Z; Khouri, N; Pinsky, R; Oesterreich, S; Zhou, C; Hadjiiski, L; Philips, S; Robarge, J; Nguyen, A T; Storniolo, A M; Flockhart, D A; Hayes, D F; Helvie, M A; Stearns, V

2013-01-01

289

CD8+ T Cell-Induced Expression of Tissue Inhibitor of Metalloproteinses-1 Exacerbated Osteoarthritis  

PubMed Central

Despites the fact that T cells are involved in the pathogenesis of osteoarthritis (OA) little is known about the roles of CD8+ T cells in this disease. We investigated the effects of CD8+ T cells and the expression of tissue inhibitor of metalloproteinases 1 (TIMP-1) on joint pathology. Using anterior cruciate ligament-transection (ACLT), OA was induced in mice. The knee joints were histologically assessed for manifestations of OA. The CD8+ T cells from splenocytes and synovium were flow-cytometrically and immunochemically evaluated, respectively. Local expression of TIMP-1, matrix metalloproteinase (MMP)-13, and VEGF were examined. Cartilage degeneration was slower in CD8+ T cell knockout mice than in control mice. CD8+ T cells were activated once OA was initiated and expanded during OA progression. More CD8+ T cells from splenocytes expressed TIMP-1 in ACLT-group mice than in Sham-group mice. The number of TIMP-1-expressing CD8+ T cells in OA mice correlated with the disease severity. TIMP-1 expression in cartilage was co-localized with that of MMP-13 and VEGF. TIMP-1 protein was detected in synovium in which angiogenesis occurred. During the pathogenesis of OA, the expression of TIMP-1, VEGF and MMP-13 accompanying with CD8+ T cells activation were increased. Furthermore, inhibiting the expression of TIMP-1 in joints could retard the progression of OA. PMID:24108368

Hsieh, Jeng-Long; Shiau, Ai-Li; Lee, Che-Hsin; Yang, Shiu-Ju; Lee, Bih-O; Jou, I-Ming; Wu, Chao-Liang; Chen, Shun-Hua; Shen, Po-Chuan

2013-01-01

290

Protection against titanium particle-induced inflammatory osteolysis by the proteasome inhibitor bortezomib in vivo.  

PubMed

Wear particle-induced vascularized granulomatous inflammation and subsequent inflammatory osteolysis is the most common cause of aseptic loosening after total joint replacement (TJR); however, the precise mechanism by which this occurs is unclear. This study investigates the effects of the proteasome inhibitor bortezomib (Bzb) on the expression of key biochemical markers of bone metabolism and vascularised granulomatous tissues, such as receptor activator of nuclear factor-?B ligand (RANKL), osteoprotegerin (OPG), vascular endothelial growth factor (VEGF) and tumor necrosis factor receptor-associated factor 6 (TRAF6). In addition, the effect of Bzb on apoptosis of CD68+ cells was examined. A total of 32 female BALB/C mice were randomly divided into four groups. After implantation of calvaria bone from syngeneic littermates, titanium (Ti) particles were injected into established air pouches for all mice (excluding negative controls) to provoke inflammatory osteolysis. Subsequently, Bzb was administered at a ratio of 0, 0.1, or 0.5 mg/kg on day 1, 4, 8, and 11 post-surgery to alleviate this response. All of the air pouches were harvested 14 days after the surgical procedure and were processed for molecular and histological analysis. The results demonstrated that Ti injection elevated the expression of RANKL, OPG, VEGF, and TRAF6 at both the gene and protein levels, increased counts of infiltrated cells and thickness of air pouch membranes, and elevated the apoptosis index (AI) of CD68+ cells. Bzb treatment significantly improved Ti particle-induced implanted bone osteolysis, attenuated vascularised granulomatous tissues and elevated AI of CD68+ cells. Therefore, the proteasome pathway may represent an effective therapeutic target for the prevention and treatment of aseptic loosening. PMID:22391745

Mao, Xin; Pan, Xiaoyun; Zhao, Song; Peng, Xiaochun; Cheng, Tao; Zhang, Xianlong

2012-08-01

291

A possible antineoplastic potential of selective, irreversible proteasome inhibitor, carfilzomib on chemically induced hepatocarcinogenesis in rats.  

PubMed

The antineoplastic effect of carfilzomib (CFZ) against chemically induced hepatocarcinogenesis was studied. A total of 60 male Wistar albino rats were divided into six groups with 10 animals in each group. Rats in group 1 (control group) were given dimethylsulphoxide (DMSO) (0.4 mL/kg i.p) twice a week for 3 weeks from week 8 to week 10. Animals in groups 2 and 3 were given CFZ (2 and 4 mg/kg i.p) twice a week from week 8 to week 10, respectively. Rats in group 4 were given diethylnitrosamine (DENA) at a dose of 0.01% in drinking water for 10 weeks and received a DMSO (0.4 mL/kg i.p) twice a week from week 8 to week 10. Animals in groups 5 and 6 were given DENA at a dose of 0.01% in drinking water for 10 weeks and treated with CFZ (2 and 4 mg/kg i.p) twice a week from week 8 to week 10, respectively. CFZ succeeded in suppressing the elevated serum tumor marker ?-fetoprotein and carcinoembryonic antigen. The antineoplastic effect of CFZ was also accompanied by normalization of elevated hepatic tissue growth factors, matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1, and augmentation of hepatic endostatin and metallothionein. A histopathological examination of liver samples treated with CFZ after DENA intoxication correlated with the biochemical observation. Treatment with CFZ confers an antineoplastic activity against chemically induced hepatocarcinogenesis. These findings suggest that CFZ plays a pivotal role in the treatment of hepatocarcinogenesis. PMID:24861196

Mansour, Mahmoud A; Aljoufi, Mohammed A; Al-Hosaini, Khaled; Al-Rikabi, Ammar C; Nagi, Mahmoud N

2014-09-01

292

PX-478, an inhibitor of hypoxia-inducible factor-1?, enhances radiosensitivity of prostate carcinoma cells  

PubMed Central

Overexpression of hypoxia-inducible factor-1? (HIF-1?) in human tumors is associated with poor prognosis and poor outcome to radiation therapy. Inhibition of HIF-1? is considered as a promising approach in cancer therapy. The purpose of this study was to test the efficacy of a novel HIF-1? inhibitor PX-478 as a radiosensitizer under normoxic and hypoxic conditions in vitro. PC3 and DU 145 prostate carcinoma cells were treated with PX-478 for 20 hr, and HIF-1? protein level and clonogenic cell survival were determined under normoxia and hypoxia. Effects of PX-478 on cell cycle distribution and phosphorylation of H2AX histone were evaluated. PX-478 decreased HIF-1? protein in PC3 and DU 145 cells. PX-478 produced cytotoxicity in both cell lines with enhanced toxicity under hypoxia for DU-145. PX-478 (20 ?mol/L) enhanced the radiosensitivity of PC3 cells irradiated under normoxic and hypoxic condition with enhancement factor (EF) 1.4 and 1.56, respectively. The drug was less effective in inhibiting HIF-1? and enhancing radiosensitivity of DU 145 cells compared to PC3 cells with EF 1.13 (normoxia) and 1.25 (hypoxia) at 50 ?mol/L concentration. PX-478 induced S/G2M arrest in PC3 but not in DU 145 cells. Treatment of PC3 and DU 145 cells with the drug resulted in phosphorylation of H2AX histone and prolongation of ?H2AX expression in the irradiated cells. PX-478 is now undergoing Phase I clinical trials as an oral agent. Although the precise mechanism of enhancement of radiosensitivity remains to be identified, this study suggests a potential role for PX-478 as a clinical radiation enhancer. PMID:18729192

Palayoor, Sanjeewani T.; Mitchell, James B.; Cerna, David; DeGraff, William; John-Aryankalayil, Molykutty; Coleman, C. Norman

2014-01-01

293

Factors associated with hospitalization of patients with angiotensin-converting enzyme inhibitor-induced angioedema.  

PubMed

Angiotensin-converting enzyme inhibitor (ACE-I)-induced angioedema can be life-threatening without emergent intervention. The putative mediator is believed to be bradykinin, similar to hereditary angioedema, so these patients respond poorly to corticosteroids and antihistamines. This study was designed to determine characteristics and clinical outcomes of patients presenting to an emergency department (ED) with ACE-I angioedema. This was a retrospective chart review of 100 patients presenting to the ED from 2007 to 2008 with an ICD-9 code of 995.1 (angioedema) or 995.2 (drug-induced angioedema). Two hundred fifty-two patients with these ICD-9 codes were identified and placed in random order, and the first 100 meeting inclusion criteria were included. Statistical analysis was primarily descriptive. All 100 patients had an ICD-9 code of 995.1 (angioedema). Patients presented in every month, with spring months (April-June) having the most presentations (32%). The median age was 59 years, 75% were African American, and 66% were admitted to the hospital. Two patients (2%) required endotracheal intubation. Lisinopril was the most commonly prescribed ACE-I (84%). The most common symptom was moderate lip and tongue swelling (89%) followed by mild difficulty breathing (12%). Tongue swelling was significantly associated with admission. Time from symptom onset to ED presentation was not associated with need for admission. Concomitant medications did not differ between admitted and discharged patients. ACE-I angioedema is associated with significant morbidity and health care use because many patients require hospitalization, suggesting an unmet need for novel therapies targeted to treat this condition. PMID:23676576

Gang, Cheng; Lindsell, Christopher J; Moellman, Joseph; Sublett, Wesley; Hart, Kim; Collins, Sean; Bernstein, Jonathan A

2013-01-01

294

Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review.  

PubMed

Exogenous cannabinoids are structurally and pharmacologically diverse compounds that are widely used. The purpose of this systematic review is to summarize the data characterizing the potential for these compounds to act as substrates, inhibitors, or inducers of human drug metabolizing enzymes, with the aim of clarifying the significance of these properties in clinical care and drug interactions. In vitro data were identified that characterize cytochrome P-450 (CYP-450) enzymes as potential significant contributors to the primary metabolism of several exogenous cannabinoids: tetrahydrocannabinol (THC; CYPs 2C9, 3A4); cannabidiol (CBD; CYPs 2C19, 3A4); cannabinol (CBN; CYPs 2C9, 3A4); JWH-018 (CYPs 1A2, 2C9); and AM2201 (CYPs 1A2, 2C9). CYP-450 enzymes may also contribute to the secondary metabolism of THC, and UDP-glucuronosyltransferases have been identified as capable of catalyzing both primary (CBD, CBN) and secondary (THC, JWH-018, JWH-073) cannabinoid metabolism. Clinical pharmacogenetic data further support CYP2C9 as a significant contributor to THC metabolism, and a pharmacokinetic interaction study using ketoconazole with oromucosal cannabis extract further supports CYP3A4 as a significant metabolic pathway for THC and CBD. However, the absence of interaction between CBD from oromucosal cannabis extract with omeprazole suggests a less significant role of CYP2C19 in CBD metabolism. Studies of THC, CBD, and CBN inhibition and induction of major human CYP-450 isoforms generally reflect a low risk of clinically significant drug interactions with most use, but specific human data are lacking. Smoked cannabis herb (marijuana) likely induces CYP1A2 mediated theophylline metabolism, although the role of cannabinoids specifically in eliciting this effect is questionable. PMID:24160757

Stout, Stephen M; Cimino, Nina M

2014-02-01

295

A critical role of the C-terminal segment for allosteric inhibitor-induced aberrant multimerization of HIV-1 integrase.  

PubMed

Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are a promising class of antiretroviral agents for clinical development. Although ALLINIs promote aberrant IN multimerization and inhibit IN interaction with its cellular cofactor LEDGF/p75 with comparable potencies in vitro, their primary mechanism of action in infected cells is through inducing aberrant multimerization of IN. Crystal structures have shown that ALLINIs bind at the IN catalytic core domain dimer interface and bridge two interacting subunits. However, how these interactions promote higher-order protein multimerization is not clear. Here, we used mass spectrometry-based protein footprinting to monitor surface topology changes in full-length WT and the drug-resistant A128T mutant INs in the presence of ALLINI-2. These experiments have identified protein-protein interactions that extend beyond the direct inhibitor binding site and which lead to aberrant multimerization of WT but not A128T IN. Specifically, we demonstrate that C-terminal residues Lys-264 and Lys-266 play an important role in the inhibitor induced aberrant multimerization of the WT protein. Our findings provide structural clues for exploiting IN multimerization as a new, attractive therapeutic target and are expected to facilitate development of improved inhibitors. PMID:25118283

Shkriabai, Nikoloz; Dharmarajan, Venkatasubramanian; Slaughter, Alison; Kessl, Jacques J; Larue, Ross C; Feng, Lei; Fuchs, James R; Griffin, Patrick R; Kvaratskhelia, Mamuka

2014-09-19

296

Activated peroxisomal fatty acid metabolism improves cardiac recovery in ischemia-reperfusion.  

PubMed

Depressed oxidation of long chain fatty acids (LCFA) in heart ischemia leads to acute accumulation of LCFA metabolites that impair the functioning of the mitochondria. We hypothesized that reduced activity of carnitine palmitoyltransferase-I (CPT-I) might activate peroxisomal LCFA oxidation and protect mitochondrial function in ischemia and reperfusion. In the present study, despite the long-term threefold reduction in L-carnitine content by 3-(2,2,2-trimethylhydrazinium)-propionate, the uptake and oxidation rates of LCFA in the heart in normoxia were not significantly influenced. The significant increase in PPAR? and PGC1? nuclear content, observed in this study, were followed by increased expression of genes involved in peroxisomal fatty acid oxidation (FAO) which compensated for the limited CPT-I-dependent FA transport into the mitochondria. In ischemia followed by reperfusion, the redirection of LCFA oxidation from mitochondria to peroxisomes protected the mitochondria from the accumulation of LCFA. In turn, the recovery of FAO resulted in significant reduction of myocardial infarct size. In conclusion, the decreased L-carnitine content in the heart preserves its peroxisomal and mitochondrial function after ischemia and improves cardiac recovery during reperfusion. The functional interplay between the decrease in L-carnitine and the PPAR?/PGC1? pathway-induced redirection of FA metabolism protects the mitochondria against LCFA overload and provides a foundation for novel cardioprotective mechanisms. PMID:23525500

Liepinsh, Edgars; Skapare, Elina; Kuka, Janis; Makrecka, Marina; Cirule, Helena; Vavers, Edijs; Sevostjanovs, Eduards; Grinberga, Solveiga; Pugovics, Osvalds; Dambrova, Maija

2013-06-01

297

High-level expression and molecular cloning of genes encoding Candida tropicalis peroxisomal proteins.  

PubMed Central

The development of peroxisomes in the cells of Candida tropicalis grown on oleic acid was accompanied by a markedly high expression of peroxisomal proteins. On the basis of this finding, the nuclear DNA library of this yeast was screened by differential hybridization, and 102 clones of oleic acid-inducible sequences were isolated. Seven coding regions were found to form clusters in three stretches of the genomic DNA. Five of the regions were identified as genes for peroxisomal polypeptides (PXPs). The coding sequence for PXP-2 hybrid selected an additional mRNA for PXP-4, the subunit of long-chain acyl coenzyme A oxidase, which was the most abundant PXP. PXP-2 and PXP-4 were close in apparent molecular weight and generated similar peptides when digested with a protease. The gene for PXP-4 was adjacent to that for PXP-2 on the genome and also hybridized to the mRNA coding for PXP-5. These and other similar results suggest that the genes for the peroxisomal proteins of this organism arose by duplication of a few ancestral genes. Images PMID:6504042

Kamiryo, T; Okazaki, K

1984-01-01

298

A receptor tyrosine kinase inhibitor, Tyrphostin A9 induces cancer cell death through Drp1 dependent mitochondria fragmentation  

SciTech Connect

Highlights: {yields} We screened and identified Tyrphostin A9, a receptor tyrosine kinase inhibitor as a strong mitochondria fission inducer. {yields} Tyrphostin A9 treatment promotes mitochondria dysfunction and contributes to cytotoxicity in cancer cells. {yields} Tyrphostin A9 induces apoptotic cell death through a Drp1-mediated pathway. {yields} Our studies suggest that Tyrphostin A9 induces mitochondria fragmentation and apoptotic cell death via Drp1 dependently. -- Abstract: Mitochondria dynamics controls not only their morphology but also functions of mitochondria. Therefore, an imbalance of the dynamics eventually leads to mitochondria disruption and cell death. To identify specific regulators of mitochondria dynamics, we screened a bioactive chemical compound library and selected Tyrphostin A9, a tyrosine kinase inhibitor, as a potent inducer of mitochondrial fission. Tyrphostin A9 treatment resulted in the formation of fragmented mitochondria filament. In addition, cellular ATP level was decreased and the mitochondrial membrane potential was collapsed in Tyr A9-treated cells. Suppression of Drp1 activity by siRNA or over-expression of a dominant negative mutant of Drp1 inhibited both mitochondrial fragmentation and cell death induced by Tyrpohotin A9. Moreover, treatment of Tyrphostin A9 also evoked mitochondrial fragmentation in other cells including the neuroblastomas. Taken together, these results suggest that Tyrphostin A9 induces Drp1-mediated mitochondrial fission and apoptotic cell death.

Park, So Jung; Park, Young Jun; Shin, Ji Hyun; Kim, Eun Sung [Graduate School of East-West Medical Science, Kyung Hee University, Gyeoggi-Do 446-701 (Korea, Republic of)] [Graduate School of East-West Medical Science, Kyung Hee University, Gyeoggi-Do 446-701 (Korea, Republic of); Hwang, Jung Jin; Jin, Dong-Hoon; Kim, Jin Cheon [Institute for Innovative Cancer Research, Asan Medical Center, Seoul 138-736 (Korea, Republic of)] [Institute for Innovative Cancer Research, Asan Medical Center, Seoul 138-736 (Korea, Republic of); Cho, Dong-Hyung, E-mail: dhcho@khu.ac.kr [Graduate School of East-West Medical Science, Kyung Hee University, Gyeoggi-Do 446-701 (Korea, Republic of)] [Graduate School of East-West Medical Science, Kyung Hee University, Gyeoggi-Do 446-701 (Korea, Republic of)

2011-05-13

299

SIRT inhibitors induce cell death and p53 acetylation through targeting both SIRT1 and SIRT2.  

PubMed

SIRT proteins play an important role in the survival and drug resistance of tumor cells, especially during chemotherapy. In this study, we investigated the potency, specificity, and cellular targets of three SIRT inhibitors, Sirtinol, Salermide, and EX527. Cell proliferative and cell cycle analyses showed that Sirtinol and Salermide, but not EX527, were effective in inducing cell death at concentrations of 50 micromol/L or over in MCF-7 cells. Instead, EX527 caused cell cycle arrest at G(1) at comparable concentrations. In vitro SIRT assays using a p53 peptide substrate showed that all three compounds are potent SIRT1/2 inhibitors, with EX527 having the highest inhibitory activity for SIRT1. Computational docking analysis showed that Sirtinol and Salermide have high degrees of selectivity for SIRT1/2, whereas EX527 has high specificity for SIRT1 but not SIRT2. Consistently, Sirtinol and Salermide, but not EX527, treatment resulted in the in vivo acetylation of the SIRT1/2 target p53 and SIRT2 target tubulin in MCF-7 cells, suggesting that EX527 is ineffective in inhibiting SIRT2 and that p53 mediates the cytotoxic function of Sirtinol and Salermide. Studies using breast carcinoma cell lines and p53-deficient mouse fibroblasts confirmed that p53 is essential for the Sirtinol and Salermide-induced apoptosis. Further, we showed using small interfering RNA that silencing both SIRTs, but not SIRT1 and SIRT2 individually, can induce cell death in MCF-7 cells. Together, our results identify the specificity and cellular targets of these novel inhibitors and suggest that SIRT inhibitors require combined targeting of both SIRT1 and SIRT2 to induce p53 acetylation and cell death. Mol Cancer Ther; 9(4); 844-55. (c)2010 AACR. PMID:20371709

Peck, Barrie; Chen, Chun-Yuan; Ho, Ka-Kei; Di Fruscia, Paolo; Myatt, Stephen S; Coombes, R Charles; Fuchter, Matthew J; Hsiao, Chwan-Deng; Lam, Eric W-F

2010-04-01

300

Prevention of HIV Protease Inhibitor-Induced Dysregulation of Hepatic Lipid Metabolism by Raltegravir via Endoplasmic Reticulum Stress Signaling Pathways  

PubMed Central

Hyperlipidemia associated with the HIV protease inhibitor (PI), the major component of highly active antiretroviral treatment (HAART) for HIV infection, has stimulated interest in developing new agents that minimize these side effects in the clinic. HIV integrase inhibitor is a new class of anti-HIV agents. Raltegravir is a first-in-its-class oral integrase inhibitor and has potent inhibitory activity against HIV-1 strains that are resistant to other antiretroviral regimens. Our previous studies have demonstrated that HIV PI-induced endoplasmic reticulum (ER) stress links to dysregulation of lipid metabolism. However, little information is available as to whether raltegravir would have similar effects as the HIV PIs. In this study, we examined the effect of raltegravir on lipid metabolism both in primary rat hepatocytes and in in vivo mouse models, and we further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed development of dyslipidemia. The results indicated that raltegravir did not induce ER stress or disrupt lipid metabolism either in vitro or in vivo. However, HIV PI-induced ER stress and lipid accumulation were significantly inhibited by raltegravir both in in vitro primary rat hepatocytes and in in vivo mouse liver. High-performance liquid chromatography analysis further demonstrated that raltegravir did not affect the uptake and metabolism of HIV PIs in hepatocytes. Thus, raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of lipid metabolism by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the side effects associated with current HAART. PMID:20472667

Cao, Risheng; Hu, Yiqiao; Wang, Yun; Gurley, Emily C.; Studer, Elaine J.; Wang, Xuan; Hylemon, Phillip B.; Pandak, William M.; Sanyal, Arun J.; Zhang, Luyong

2010-01-01

301

Effects of rolipram and roflumilast, phosphodiesterase-4 inhibitors, on hypertension-induced defects in memory function in rats.  

PubMed

Hypertension (HT) is a prevailing risk factor for cognitive impairment, the most common cause of vascular dementia; yet, no possible mechanism underlying the cognitive impairment induced by hypertension has been identified so far. Inhibition of PDE-4 has been shown to increase phosphorylation of cAMP-response element binding protein in the hippocampus and enhance the memory performance. Here, we examined the effects of PDE-4 inhibitors, rolipram and roflumilast, on the impairment of learning and memory observed in hypertensive rats. We used 2k-1c hypertensive model to induce learning and memory defects. In addition, mRNA expression of PDE-4 sub-types A-D was also assessed in the hippocampus tissue. Systolic blood pressure (SBP) was measured by tail-cuff method was significantly increased in 2k-1c rats when compared to sham operated rats; this effect was reversed by clonidine, whereas, PDE-4 inhibitors did not. PDE-4 inhibitors significantly reversed time induced memory deficit in novel object recognition task (NORT). Further, the retention latency on the second day in the elevated plus maze model was significantly shortened after repeated administration of rolipram and roflumilast. Plasma and brain concentrations of rolipram, roflumilast and roflumilast N-oxide were also measured after the NORT and showed linear increase in plasma and brain concentrations. The PDE4B and PDE4D gene expression was significantly enhanced in hypertensive rats compared with sham operated however PDE4A and PDE4C remained unaltered. Repeated treatment with PDE-4 inhibitors caused down regulation of PDE4B and PDE4D in hypertensive rats. These results suggest that inhibition of PDE-4 ameliorates HT-induced impairment of learning and memory functions. PMID:25446433

Jabaris, Sobhana George Sugin Lal; Sumathy, Haridass; Kumar, Ramadass Satiesh; Narayanan, Shridhar; Thanikachalam, Sadagopan; Babu, Chidambaram Saravana

2015-01-01

302

Dissection of Arabidopsis Bax Inhibitor1 Suppressing Bax, Hydrogen Peroxide, and Salicylic Acid-Induced Cell Death  

Microsoft Academic Search

Overexpression of plant Bax Inhibitor-1 (BI-1) was able to suppress Bax-mediated cell death in yeast and Arabidopsis. Here, we demonstrate that reactive oxygen species production induced by the ectopic expression of Bax was insensitive to the coexpression of AtBI-1. Similarly, H 2 O 2 - or salicylic acid-mediated cell death also was suppressed in tobacco BY-2 cells overexpressing AtBI-1. To

Maki Kawai-Yamada; Yuri Ohori; Hirofumi Uchimiya

2003-01-01

303

PP1 Inhibitor Induces Degradation of RETMEN2A and RETMEN2B Oncoproteins through Proteosomal Targeting1  

Microsoft Academic Search

RET tyrosine kinase oncoproteins are potential targets for anticancer therapy. We show here that along with the inhibition of RET tyrosine phosphorylation, the pyrazolo-pyrimidine inhibitor PP1 induces RETMEN2A and RETMEN2B oncoprotein destruction. In fact, as a consequence of PP1 treatment, RET oncoproteins translocate from the outer limiting membrane to inner cellular compartments and are rapidly addressed to the degradative pathway.

Cristiana Carniti; Carla Perego; Piera Mondellini; Marco Alessandro Pierotti; Italia Bongarzone

2003-01-01

304

NAAG peptidase inhibitors block cognitive deficit induced by MK-801 and motor activation induced by d-amphetamine in animal models of schizophrenia.  

PubMed

The most widely validated animal models of the positive, negative and cognitive symptoms of schizophrenia involve administration of d-amphetamine or the open channel NMDA receptor blockers, dizocilpine (MK-801), phencyclidine (PCP) and ketamine. The drug ZJ43 potently inhibits glutamate carboxypeptidase II (GCPII), an enzyme that inactivates the peptide transmitter N-acetylaspartylglutamate (NAAG) and reduces positive and negative behaviors induced by PCP in several of these models. NAAG is an agonist at the metabotropic glutamate receptor 3 (mGluR3). Polymorphisms in this receptor have been associated with expression of schizophrenia. This study aimed to determine whether two different NAAG peptidase inhibitors are effective in dopamine models, whether their efficacy was eliminated in GCPII knockout mice and whether the efficacy of these inhibitors extended to MK-801-induced cognitive deficits as assessed using the novel object recognition test. ZJ43 blocked motor activation when given before or after d-amphetamine treatment. (R,S)-2-phosphono-methylpentanedioic acid (2-PMPA), another potent NAAG peptidase inhibitor, also reduced motor activation induced by PCP or d-amphetamine. 2-PMPA was not effective in GCPII knockout mice. ZJ43 and 2-PMPA also blocked MK-801-induced deficits in novel object recognition when given before, but not after, the acquisition trial. The group II mGluR antagonist LY341495 blocked the effects of NAAG peptidase inhibition in these studies. 2-PMPA was more potent than ZJ43 in a test of NAAG peptidase inhibition in vivo. By bridging the dopamine and glutamate theories of schizophrenia with two structurally different NAAG peptidase inhibitors and demonstrating their efficacy in blocking MK-801-induced memory deficits, these data advance the concept that NAAG peptidase inhibition represents a potentially novel antipsychotic therapy. PMID:22850437

Olszewski, R T; Janczura, K J; Ball, S R; Madore, J C; Lavin, K M; Lee, J C-M; Lee, M J; Der, E K; Hark, T J; Farago, P R; Profaci, C P; Bzdega, T; Neale, J H

2012-01-01

305

Organic cadmium complexes as proteasome inhibitors and apoptosis inducers in human breast cancer cells.  

PubMed

Although cadmium (Cd) is a widespread environmental contaminant and human carcinogen, our studies indicate an organic Cd complex to be a potent inhibitor of proteasomal chymotrypsin-like (CT-like) activity, further capable of inducing apoptosis in a cancer cell-specific manner. It has been reported that the ligands indole-3-butyric acid (L1) and indole-3-propionic acid (L2) have cancer-fighting effects when tested in a rat carcinoma model. In addition, 3, 5-diaminobenzoic acid o-vanillin Schiff bases (L3) have high antimicrobial activity and a large number of Schiff base complexes have been reported to have proteasome-inhibitory activity. We therefore hypothesized that synthetic forms of Cd in combination with L1, L2 and L3 may have proteasome-inhibitory and apoptosis-inducing activities, which would be cancer cell-specific. To test this hypothesis, we have synthesized three novel Cd-containing complexes: [Cd2(C12H12O2N)4(H2O)2]·2H2O (Cd1), [Cd2(C11H10O2N)4(H2O)2]·2H2O (Cd2) and [Cd(C7H4N2O2)(C8H6O2)2]·2H2O (Cd3), by using these three ligands. We sought out to characterize and assess the proteasome-inhibitory and anti-proliferative properties of these three Cd complexes in human breast cancer cells. Cd1, Cd2 and Cd3 were found to effectively inhibit the chymotrypsin-like activity of purified 20S proteasome with IC50 values of 2.6, 3.0 and 3.3 ??, respectively. Moreover, inhibition of cancer cell proliferation also correlated with this effect. As a result of proteasomal shutdown, the accumulation of ubiquitinated proteins and the proteasome target I?B-? protein as well as induction of apoptosis were observed. To account for the cancer specificity of this effect, immortalized, non-tumorigenic breast MCF10A cells were used under the same experimental conditions. Our results indicate that MCF10A cells are much less sensitive to the Cd1, Cd2 and Cd3 complexes when compared to MDA MB 231 breast cancer cells. Therefore, our study suggests that these Cd organic complexes are capable of inhibiting tumor cellular proteasome activity and consequently induce cancer cell-specific apoptotic death. PMID:23499788

Zhang, Zhen; Bi, Caifeng; Buac, Daniela; Fan, Yuhua; Zhang, Xia; Zuo, Jian; Zhang, Pengfei; Zhang, Nan; Dong, Lili; Dou, Q Ping

2013-06-01

306

Inhibitors of glutamate release from breast cancer cells; new targets for cancer-induced bone-pain  

PubMed Central

Glutamate is an important signaling molecule in a wide variety of tissues. Aberrant glutamatergic signaling disrupts normal tissue homeostasis and induces several disruptive pathological conditions including pain. Breast cancer cells secrete high levels of glutamate and often metastasize to bone. Exogenous glutamate can disrupt normal bone turnover and may be responsible for cancer-induced bone pain (CIBP). CIBP is a significant co-morbidity that affects quality of life for many advanced-stage breast cancer patients. Current treatment options are commonly accompanied by serious side-effects that negatively impact patient care. Identifying small molecule inhibitors of glutamate release from aggressive breast cancer cells advances a novel, mechanistic approach to targeting CIBP that could advance treatment for several pathological conditions. Using high-throughput screening, we investigated the ability of approximately 30,000 compounds from the Canadian Compound Collection to reduce glutamate release from MDA-MB-231 breast cancer cells. This line is known to secrete high levels of glutamate and has been demonstrated to induce CIBP by this mechanism. Positive chemical hits were based on the potency of each molecule relative to a known pharmacological inhibitor of glutamate release, sulfasalazine. Efficacy was confirmed and drug-like molecules were identified as potent inhibitors of glutamate secretion from MDA-MB-231, MCF-7 and Mat-Ly-Lu cells. PMID:25670024

Fazzari, Jennifer; Lin, Hanxin; Murphy, Cecilia; Ungard, Robert; Singh, Gurmit

2015-01-01

307

Oral administration of the NAALADase inhibitor GPI-5693 attenuates cocaine-induced reinstatement of drug-seeking behavior in rats.  

PubMed

We have recently reported that the endogenous mGlu2/3 agonist N-acetylaspartylglutamate (NAAG) and the N-acetylated-alpha-linked-acidic dipeptidase (NAALADase, a NAAG degradation enzyme) inhibitor 2-PMPA significantly inhibit cocaine self-administration and cocaine-induced reinstatement of drug-seeking behavior by attenuating cocaine-enhanced extracellular dopamine and glutamate in the nucleus accumbens. However, the poor oral bioavailability of NAAG and 2-PMPA limits their practical use in humans. In the present study, we investigated the effects of the orally active NAALADase inhibitor GPI-5693 and its enantiomers on cocaine-taking and cocaine-seeking behaviours. We found that oral administration of GPI-5693 (15, 30, 60 mg/kg, p.o.) did not significantly alter intravenous cocaine self-administration under fixed-ratio (FR2) reinforcement, but significantly inhibited cocaine-induced reinstatement of the extinguished drug-seeking behavior. This inhibition was blocked by pretreatment with LY341495, a selective mGlu2/3 receptor antagonist. Pretreatment with the same doses (15, 30, 60 mg/kg, p.o.) of GPI-16476 or GPI-16477, two enantiomers of GPI-5693, also inhibited cocaine-induced reinstatement similar to GPI-5693. In contrast, GPI-5693 altered neither oral sucrose self-administration nor sucrose-triggered reinstatement of sucrose-seeking behavior. These data suggest that orally effective NAAG peptidase inhibitors deserve further study as potential agents for the treatment of cocaine addiction. PMID:19887067

Peng, Xiao-Qing; Li, Jie; Gardner, Eliot L; Ashby, Charles R; Thomas, Ajit; Wozniak, Krystyna; Slusher, Barbara S; Xi, Zheng-Xiong

2010-02-10

308

Inhibitors of glutamate release from breast cancer cells; new targets for cancer-induced bone-pain.  

PubMed

Glutamate is an important signaling molecule in a wide variety of tissues. Aberrant glutamatergic signaling disrupts normal tissue homeostasis and induces several disruptive pathological conditions including pain. Breast cancer cells secrete high levels of glutamate and often metastasize to bone. Exogenous glutamate can disrupt normal bone turnover and may be responsible for cancer-induced bone pain (CIBP). CIBP is a significant co-morbidity that affects quality of life for many advanced-stage breast cancer patients. Current treatment options are commonly accompanied by serious side-effects that negatively impact patient care. Identifying small molecule inhibitors of glutamate release from aggressive breast cancer cells advances a novel, mechanistic approach to targeting CIBP that could advance treatment for several pathological conditions. Using high-throughput screening, we investigated the ability of approximately 30,000 compounds from the Canadian Compound Collection to reduce glutamate release from MDA-MB-231 breast cancer cells. This line is known to secrete high levels of glutamate and has been demonstrated to induce CIBP by this mechanism. Positive chemical hits were based on the potency of each molecule relative to a known pharmacological inhibitor of glutamate release, sulfasalazine. Efficacy was confirmed and drug-like molecules were identified as potent inhibitors of glutamate secretion from MDA-MB-231, MCF-7 and Mat-Ly-Lu cells. PMID:25670024

Fazzari, Jennifer; Lin, Hanxin; Murphy, Cecilia; Ungard, Robert; Singh, Gurmit

2015-01-01

309

Reduction of the HIV Protease Inhibitor-Induced ER Stress and Inflammatory Response by Raltegravir in Macrophages  

PubMed Central

Background HIV protease inhibitor (PI), the core component of highly active antiretroviral treatment (HAART) for HIV infection, has been implicated in HAART-associated cardiovascular complications. Our previous studies have demonstrated that activation of endoplasmic reticulum (ER) stress is linked to HIV PI-induced inflammation and foam cell formation in macrophages. Raltegravir is a first-in-its-class HIV integrase inhibitor, the newest class of anti-HIV agents. We have recently reported that raltegravir has less hepatic toxicity and could prevent HIV PI-induced dysregulation of hepatic lipid metabolism by inhibiting ER stress. However, little information is available as to whether raltegravir would also prevent HIV PI-induced inflammatory response and foam cell formation in macrophages. Methodology and Principal Findings In this study, we examined the effect of raltegravir on ER stress activation and lipid accumulation in cultured mouse macrophages (J774A.1), primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV PIs would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. The results indicated that raltegravir did not induce ER stress and inflammatory response in macrophages. Even more interestingly, HIV PI-induced ER stress, oxidative stress, inflammatory response and foam cell formation were significantly reduced by raltegravir. High performance liquid chromatography (HPLC) analysis further demonstrated that raltegravir did not affect the uptake of HIV PIs in macrophages. Conclusion and Significance Raltegravir could prevent HIV PI-induced inflammatory response and foam cell formation by inhibiting ER stress. These results suggest that incorporation of this HIV integrase inhibitor may reduce the cardiovascular complications associated with current HAART. PMID:24625618

Liu, Runping; Zhao, Renping; Huang, Yi; Gurley, Emily C.; Hylemon, Phillip B.; Pandak, William M.; Wang, Guangji; Zhang, Luyong; Li, Xiaokun; Zhou, Huiping

2014-01-01

310

The ATRA-induced differentiation of medulloblastoma cells is enhanced with LOX/COX inhibitors: an analysis of gene expression  

PubMed Central

Background A detailed analysis of the expression of 440 cancer-related genes was performed after the combined treatment of medulloblastoma cells with all-trans retinoic acid (ATRA) and inhibitors of lipoxygenases (LOX) and cyclooxygenases (COX). The combinations of retinoids and celecoxib as a COX-2 inhibitor were reported to be effective in some regimens of metronomic therapy of relapsed solid tumors with poor prognosis. Our previous findings on neuroblastoma cells using expression profiling showed that LOX/COX inhibitors have the capability of enhancing the differentiating action of ATRA. Presented study focused on the continuation of our previous work to confirm the possibility of enhancing ATRA-induced cell differentiation in these cell lines via the application of LOX/COX inhibitors. This study provides more detailed information concerning the mechanisms of the enhancement of the ATRA-induced differentiation of medulloblastoma cells. Methods The Daoy and D283 Med medulloblastoma cell lines were chosen for this study. Caffeic acid (an inhibitor of 5-LOX) and celecoxib (an inhibitor on COX-2) were used in combined treatment with ATRA. The expression profiling was performed using Human Cancer Oligo GEArray membranes, and the most promising results were verified using RT-PCR. Results The expression profiling of the selected cancer-related genes clearly confirmed that the differentiating effects of ATRA should be enhanced via its combined administration with caffeic acid or celecoxib. This effect was detected in both cell lines. An increased expression of the genes that encoded the proteins participating in induced differentiation and cytoskeleton remodeling was detected in both cell lines in a concentration-dependent manner. This effect was also observed for the CDKN1A gene encoding the p21 protein, which is an important regulator of the cell cycle, and for the genes encoding proteins that are associated with proteasome activity. Furthermore, our results showed that D283 Med cells are significantly more sensitive to treatment with ATRA alone than Daoy cells. Conclusions The obtained results on medulloblastoma cell lines are in accordance with our previous findings on neuroblastoma cells and confirm our hypothesis concerning the common mechanism of the enhancement of ATRA-induced cell differentiation in various types of pediatric solid tumors. PMID:24959102

2014-01-01

311

Calpain inhibitors delay injury-induced apoptosis in adult mouse spinal cord motor neurons.  

PubMed

Here, we investigated the effect of calpain inhibitors on apoptosis in organotypic adult spinal cord slices from mice. An increase in calpain I immunoreactivity was found in the nuclei of motor neurons from slices cultured for 30 min. After 4 h, the immunopositive motor neurons exhibited apoptotic changes including nuclear and chromatin condensation. Eight hours after excision, most motor neurons showed nuclear apoptotic features. Two calpain inhibitors, leupeptin and calpain inhibitor XI, inhibited apoptosis in the motor neurons while the caspase inhibitor Z-VAD.fmk had no effect. Leupeptin, but not calpain inhibitor XI and Z-VAD.fmk, also inhibited nucleosomal DNA fragmentation. These results suggest the involvement of calpain I in the induction of apoptosis in motor neurons of adult spinal cord and that apoptosis can be triggered independent of caspase activation. PMID:16708011

Momeni, Hamid R; Kanje, Martin

2006-05-29

312

HY-2, a novel DNA topoisomerase II inhibitor, induces G2/M cell cycle arrest in HCT-116 cells.  

PubMed

4beta-(Benzoylthioureido)-4'-demethyl-4-desoxypodophyllotoxin (HY-2), a synthetic aroylthiourea analog of podophyllotoxin, was identified as a novel DNA topoisomerase II inhibitor. It exhibited significant antiproliferative effect on seven cancer cell lines and induced HCT-116 cells apoptosis. DNA flow cytometric analysis revealed that HY-2 induced cell cycle arrest at G2/M phase. Western blot analysis indicated that phosphorylation of cdc2 protein was decreased after HY-2 treatment, which might be the main cause for G2/M phase arrest. PMID:24188177

Wu, Zhonghua; Zhao, Yu; Zhang, Yuting; Zhu, Li

2014-12-01

313

Histone Deacetylase Inhibitor Valproic Acid Promotes the Differentiation of Human Induced Pluripotent Stem Cells into Hepatocyte-Like Cells  

PubMed Central

In this study, we aimed to elucidate the effects and mechanism of action of valproic acid on hepatic differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells. Human induced pluripotent stem cells were differentiated into endodermal cells in the presence of activin A and then into hepatic progenitor cells using dimethyl sulfoxide. Hepatic progenitor cells were matured in the presence of hepatocyte growth factor, oncostatin M, and dexamethasone with valproic acid that was added during the maturation process. After 25 days of differentiation, cells expressed hepatic marker genes and drug-metabolizing enzymes and exhibited drug-metabolizing enzyme activities. These expression levels and activities were increased by treatment with valproic acid, the timing and duration of which were important parameters to promote differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells into hepatocytes. Valproic acid inhibited histone deacetylase activity during differentiation of human induced pluripotent stem cells, and other histone deacetylase inhibitors also enhanced differentiation into hepatocytes. In conclusion, histone deacetylase inhibitors such as valproic acid can be used to promote hepatic differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells. PMID:25084468

Kondo, Yuki; Iwao, Takahiro; Yoshihashi, Sachimi; Mimori, Kayo; Ogihara, Ruri; Nagata, Kiyoshi; Kurose, Kouichi; Saito, Masayoshi; Niwa, Takuro; Suzuki, Takayoshi; Miyata, Naoki; Ohmori, Shigeru; Nakamura, Katsunori; Matsunaga, Tamihide

2014-01-01

314

Effects of an endogenous nitric oxide synthase inhibitor on phorbol myristate acetate-induced acute lung injury in rats.  

PubMed

1. In the present study, we determined whether the endogenous nitric oxide (NO) synthase (NOS) inhibitor Nomega-nitro-l-arginine methyl ester (l-NAME) could ameliorate the acute lung injury (ALI) induced by phorbol myristate acetate (PMA) in rat isolated lung. 2. Typical ALI was induced successfully by PMA during 60 min of observation. At 2 micro g/kg, PMA elicited a significant increase in microvascular permeability (measured using the capillary filtration coefficient Kfc), lung weight gain, lung weight/bodyweight ratio, pulmonary arterial pressure (PAP) and protein concentration of bronchoalveolar lavage fluid. 3. Pretreatment with the NOS inhibitor l-NAME (5 mmol/L) significantly attenuated ALI. None of the parameters reflective of lung injury showed significant increase, except for PAP (P < 0.001). The addition of l-arginine (4 mmol/L) blocked the protective effective of l-NAME. Pretreatment with l-arginine exacerbated PMA-induced lung injury. 4. These data suggest that l-NAME significantly ameliorates ALI induced by PMA in rats, indicating that endogenous NO plays a key role in the development of lung oedema in PMA-induced lung injury. PMID:12859432

Lin, Hen I; Chu, Shi Jye; Wang, David; Chen, Hsing I; Hsu, Kang

2003-01-01

315

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDs and Cox 2 inhibitors.  

PubMed

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form. The most selective compound was Dup697 and the least selective, ketoprofen. Several compounds only produced a partial inhibition of constitutive cyclooxygenase as the maximum inhibitor concentration achievable in the assay was limited to 1 mM. With the exception of paracetamol, all compounds were able to produce full inhibition curves against the inducible form. Potency estimates against constitutive Cox compare closely with published data but most compounds were consistently more potent against the inducible isoform than in published data for human cloned, microsomal Cox 2. These data suggest that human mononuclear cells are either exquisitely sensitive to some NSAIDs or they may contain another Cox isoform as yet indistinguishable from Cox 2. PMID:7583521

Grossman, C J; Wiseman, J; Lucas, F S; Trevethick, M A; Birch, P J

1995-06-01

316

Herpesvirus-associated ubiquitin-specific protease (HAUSP) modulates peroxisome proliferator-activated receptor ? (PPAR?) stability through its deubiquitinating activity.  

PubMed

The peroxisome proliferator-activated receptor ? (PPAR?) is a central regulator of adipogenesis and modulates glucose and lipid metabolism. In this study, herpesvirus-associated ubiquitin-specific protease (HAUSP) was isolated as a binding partner of PPAR?. Both endogenous and exogenous PPAR? associated with HAUSP in co-immunoprecipitation analysis. HAUSP, but not the catalytically inactive HAUSP C223S mutant, increased the stability of both endogenous and exogenous PPAR? through its deubiquitinating activity. Site-directed mutagenesis experiments showed that the Lys(462) residue of PPAR? is critical for ubiquitination. HBX 41,108, a specific inhibitor of HAUSP, abolished the increase in PPAR? stability induced by HAUSP. In addition, knockdown of endogenous HAUSP using siRNA decreased PPAR? protein levels. HAUSP enhanced the transcriptional activity of both exogenous and endogenous PPAR? in luciferase activity assays. Quantitative RT-PCR analysis showed that HAUSP increased the transcript levels of PPAR? target genes in HepG2 cells, resulting in the enhanced uptake of glucose and fatty acids, and vice versa, upon siRNA knockdown of HAUSP. In vivo analysis using adenoviruses confirmed that HAUSP, but not the HAUSP C223S mutant, decreased blood glucose and triglyceride levels, which are associated with the increased expression of endogenous PPAR? and lipid accumulation in the liver. Our results demonstrate that the stability and activity of PPAR? are modulated by the deubiquitinating activity of HAUSP, which may be a target for the development of anti-diabetic drugs. PMID:24072712

Lee, Kyeong Won; Cho, Jin Gu; Kim, Chul Min; Kang, A Young; Kim, Min; Ahn, Byung Yong; Chung, Sung Soo; Lim, Key-Hwan; Baek, Kwang-Hyun; Sung, Jong-Hyuk; Park, Kyong Soo; Park, Sang Gyu

2013-11-15

317

Herpesvirus-associated Ubiquitin-specific Protease (HAUSP) Modulates Peroxisome Proliferator-activated Receptor ? (PPAR?) Stability through Its Deubiquitinating Activity*  

PubMed Central

The peroxisome proliferator-activated receptor ? (PPAR?) is a central regulator of adipogenesis and modulates glucose and lipid metabolism. In this study, herpesvirus-associated ubiquitin-specific protease (HAUSP) was isolated as a binding partner of PPAR?. Both endogenous and exogenous PPAR? associated with HAUSP in co-immunoprecipitation analysis. HAUSP, but not the catalytically inactive HAUSP C223S mutant, increased the stability of both endogenous and exogenous PPAR? through its deubiquitinating activity. Site-directed mutagenesis experiments showed that the Lys462 residue of PPAR? is critical for ubiquitination. HBX 41,108, a specific inhibitor of HAUSP, abolished the increase in PPAR? stability induced by HAUSP. In addition, knockdown of endogenous HAUSP using siRNA decreased PPAR? protein levels. HAUSP enhanced the transcriptional activity of both exogenous and endogenous PPAR? in luciferase activity assays. Quantitative RT-PCR analysis showed that HAUSP increased the transcript levels of PPAR? target genes in HepG2 cells, resulting in the enhanced uptake of glucose and fatty acids, and vice versa, upon siRNA knockdown of HAUSP. In vivo analysis using adenoviruses confirmed that HAUSP, but not the HAUSP C223S mutant, decreased blood glucose and triglyceride levels, which are associated with the increased expression of endogenous PPAR? and lipid accumulation in the liver. Our results demonstrate that the stability and activity of PPAR? are modulated by the deubiquitinating activity of HAUSP, which may be a target for the development of anti-diabetic drugs. PMID:24072712

Lee, Kyeong Won; Cho, Jin Gu; Kim, Chul Min; Kang, A Young; Kim, Min; Ahn, Byung Yong; Chung, Sung Soo; Lim, Key-Hwan; Baek, Kwang-Hyun; Sung, Jong-Hyuk; Park, Kyong Soo; Park, Sang Gyu

2013-01-01

318

The life of the peroxisome: from birth to death.  

PubMed

Peroxisomes are dynamic and metabolically plastic organelles. Their multiplicity of functions impacts on many aspects of plant development and survival. New functions for plant peroxisomes such as in the synthesis of biotin, ubiquinone and phylloquinone are being uncovered and their role in generating reactive oxygen species (ROS) and reactive nitrogen species (RNS) as signalling hubs in defence and development is becoming appreciated. Understanding of the biogenesis of peroxisomes, mechanisms of import and turnover of their protein complement, and the wholesale destruction of the organelle by specific autophagic processes is giving new insight into the ways that plants can adjust peroxisome function in response to changing needs. PMID:25261594

Baker, Alison; Paudyal, Rupesh

2014-12-01

319

Phosphoinositide synthesis and degradation in isolated rat liver peroxisomes  

Microsoft Academic Search

Analyzing peroxisomal phosphoinositide (PId#) synthesis in highly purified rat liver peroxisomes we found synthesis of phosphatidylinositol 4-phosphate (PtdIns4P), PtdIns(4,5)P2 and PtdIns(3,5)P2. PtdIns3P was hardly detected in vitro, however, was observed in vivo after [32P]-phosphate labeling of primary rat hepatocytes. In comparison with other subcellular organelles peroxisomes revealed a unique PId pattern suggesting peroxisomal specificity of the observed synthesis. Use of

Boyan Jeynov; Dorothee Lay; Frank Schmidt; Sabina Tahirovic; Wilhelm W. Just

2006-01-01

320

Emerging role of the endoplasmic reticulum in peroxisome biogenesis  

PubMed Central

During the past few years, we have witnessed a paradigm shift in our long-standing concept of peroxisome biogenesis. Recent biochemical and morphological studies have revealed a primary role of the endoplasmic reticulum (ER) in the de novo formation of peroxisomes, thus challenging the prevalent model invoking growth and division of pre-existing peroxisomes. Importantly, a novel sorting process has been recently defined at the ER that segregates and assembles specific sets of peroxisomal membrane proteins (PMPs) into distinct pre-peroxisomal vesicular carriers (ppVs) that later undergo heterotypic fusion to form mature peroxisomes. Consequently, the emerging model has redefined the function of many peroxins (most notably Pex3, Pex19, and Pex25) and assigned them novel roles in vesicular budding and subsequent peroxisome assembly. These advances establish a novel intracellular membrane trafficking route between the ER and peroxisomes, but the components remain elusive. This review will provide a historical perspective and focus on recent developments in the emerging role of the ER in peroxisome biogenesis. PMID:24115935

Agrawal, Gaurav; Subramani, Suresh

2013-01-01

321

Inter-?-inhibitor impairs TSG-6-induced hyaluronan cross-linking.  

PubMed

Under inflammatory conditions and in the matrix of the cumulus-oocyte complex, the polysaccharide hyaluronan (HA) becomes decorated covalently with heavy chains (HCs) of the serum glycoprotein inter-?-inhibitor (I?I). This alters the functional properties of the HA as well as its structural role within extracellular matrices. The covalent transfer of HCs from I?I to HA is catalyzed by TSG-6 (tumor necrosis factor-stimulated gene-6), but TSG-6 is also known as a HA cross-linker that induces condensation of the HA matrix. Here, we investigate the interplay of these two distinct functions of TSG-6 by studying the ternary interactions of I?I and TSG-6 with well defined films of end-grafted HA chains. We demonstrate that TSG-6-mediated cross-linking of HA films is impaired in the presence of I?I and that this effect suppresses the TSG-6-mediated enhancement of HA binding to CD44-positive cells. Furthermore, we find that the interaction of TSG-6 and I?I in the presence of HA gives rise to two types of complexes that independently promote the covalent transfer of heavy chains to HA. One type of complex interacts very weakly with HA and is likely to correspond to the previously reported covalent HC·TSG-6 complexes. The other type of complex is novel and binds stably but noncovalently to HA. Prolonged incubation with TSG-6 and I?I leads to HA films that contain, in addition to covalently HA-bound HCs, several tightly but noncovalently bound molecular species. These findings have important implications for understanding how the biological activities of TSG-6 are regulated, such that the presence or absence of I?I will dictate its function. PMID:24005673

Baranova, Natalia S; Foulcer, Simon J; Briggs, David C; Tilakaratna, Viranga; Enghild, Jan J; Milner, Caroline M; Day, Anthony J; Richter, Ralf P

2013-10-11

322

The Bcr-Abl kinase inhibitor INNO-406 induces autophagy and different modes of cell death execution in Bcr-Abl-positive leukemias  

Microsoft Academic Search

Bcr-Abl tyrosine kinase (TK) inhibitors are promising therapeutic agents for Bcr-Abl-positive (Bcr-Abl+) leukemias. Although they are known to promote caspase-mediated apoptosis, it remains unclear whether caspase-independent cell death-inducing mechanisms are also triggered. Here we demonstrated that INNO-406, a second-generation Bcr-Abl TK inhibitor, induces programmed cell death (PCD) in chronic myelogenous leukemia (CML) cell lines through both caspase-mediated and caspase-independent pathways.

Y Kamitsuji; J Kuroda; S Kimura; S Toyokuni; K Watanabe; E Ashihara; H Tanaka; Y Yui; M Watanabe; H Matsubara; Y Mizushima; Y Hiraumi; E Kawata; T Yoshikawa; T Maekawa; T Nakahata; S Adachi

2008-01-01

323

Recombinant tissue factor pathway inhibitor prevents lipopolysaccharide-induced systemic hypotension in rats by inhibiting excessive production of nitric oxide.  

PubMed

Excessive production of nitric oxide (NO) by the inducible form of NO synthase (iNOS) plays a key role in the development of endotoxin shock. Tumor necrosis factor-alpha (TNF-alpha) induces iNOS, thereby contributing to the development of shock. We recently reported that recombinant tissue factor pathway inhibitor (r-TFPI), an important inhibitor of the extrinsic pathway of the coagulation system, inhibits TNF-alpha production by monocytes. In this study, we investigated whether r-TFPI could ameliorate hypotension by inhibiting excessive production of NO in rats given lipopolysaccharide (LPS). Pretreatment of animals with r-TFPI prevented LPS-induced hypotension. Recombinant TFPI significantly inhibited the increases in both the plasma levels of NO2-/NO3- and lung iNOS activity 3 h after LPS administration. Expression of iNOS mRNA in the lung was also inhibited by intravenous administration of r-TFPI. However, neither DX-9065a, a selective inhibitor of factor Xa, nor an inactive derivative of factor VIIa (DEGR-F.Vlla) that selectively inhibits factor VIIa activity, had any effect on LPS-induced hypotension despite their potent anticoagulant effects. Moreover, neither the plasma levels of NO2-/NO3- nor lung iNOS activity were affected by administration of DX-9065a and DEGR-F.VIIa. These results suggested that r-TFPI ameliorates LPS-induced hypotension by reducing excessive production of NO in rats given LPS and this effect was not attributable to its anticoagulant effects, but to the inhibition of TNF-alpha production. PMID:11776329

Enkhbaatar, P; Okajima, K; Uchiba, M; Isobe, H; Okabe, H

2001-12-01

324

Chondrosarcoma and Peroxisome Proliferator-Activated Receptor  

PubMed Central

Induction of differentiation and apoptosis in cancer cells by ligands of PPAR? is a novel therapeutic approach to malignant tumors. Chondrosarcoma (malignant cartilage tumor) and OUMS-27 cells (cell line established from grade III human chondrosarcoma) express PPAR?. PPAR? ligands inhibited cell proliferation in a dose-dependent manner, and induced apoptosis of OUMS-27. The higher-grade chondrosarcoma expressed a higher amount of antiapoptotic Bcl-xL in vivo. The treatment of OUMS-27 by 15d-PGJ2, the most potent endogenous ligand for PPAR?, downregulated expression of Bcl-xL and induced transient upregulation of proapoptotic Bax, which could accelerate cytochrome c release from mitochondria to the cytosol, followed by induction of caspase-dependent apoptosis. 15d-PGJ2 induced the expression of CDK inhibitor p21 protein in human chondrosarcoma cells, which appears to be involved in the mechanism of inhibition of cell proliferation. These findings suggest that targeted therapy with PPAR? ligands could be a novel strategy against chondrosarcoma. PMID:18725985

Nishida, K.; Kunisada, T.; Shen, Z. N.; Kadota, Y.; Hashizume, K.; Ozaki, T.

2008-01-01

325

Peroxisomal localization and activation by bivalent metal ions of ureidoglycolate lyase, the enzyme involved in urate degradation in Candida tropicalis  

SciTech Connect

Ureidoglycolate lyase was found only in the peroxisomes in urate-induced Candida tropicalis. The enzyme was markedly activated by the bivalent metal ions Mn/sup 2 +/, Fe/sup 2 +/, and Ni/sup 2 +/. The activation by Mn/sup 2 +/ was suggested to be the result of its binding to the apoenzyme.

Takada, Y.; Tsukiji, N.

1987-05-01

326

Peroxisome proliferator-activated receptor ? reduces the growth rate of pancreatic cancer cells through the reduction of cyclin D1  

Microsoft Academic Search

Peroxisome proliferator-activated receptor ? (PPAR?) forms a heterodimeric DNA-binding complex with the retinoid X receptor (RXR) and regulates the transcription of its target genes. Activation of PPAR? has been shown to induce G1 arrest and to inhibit cell growth of human pancreatic carcinoma cell lines. The purpose of the present study was to examine the effect of ligand activation of

Miyuki Toyota; Yoshiji Miyazaki; Shinji Kitamura; Yutaka Nagasawa; Tatsuya Kiyohara; Yasuhisa Shinomura; Yuji Matsuzawa

2002-01-01

327

Histone deacetylase inhibitors reverse manic-like behaviors and protect the rat brain from energetic metabolic alterations induced by ouabain.  

PubMed

Studies have revealed alterations in mitochondrial complexes in the brains of bipolar patients. However, few studies have examined changes in the enzymes of the tricarboxylic acid cycle. Several preclinical studies have suggested that histone deacetylase inhibitors may have antimanic effects. The present study aims to investigate the effects of lithium, valproate and sodium butyrate, a histone deacetylase inhibitor, on the activity of tricarboxylic acid cycle enzymes in the brains of rats subjected to an animal model of mania induced by ouabain. Wistar rats received a single intracerebroventricular injection of ouabain or cerebrospinal fluid. Starting on the day following the intracerebroventricular injection, the rats were treated for 7days with intraperitoneal injections of saline, lithium, valproate or sodium butyrate. Risk-taking behavior, locomotor and exploratory activities were measured using the open-field test. Citrate synthase, succinate dehydrogenase, and malate dehydrogenase were examined in the frontal cortex and hippocampus. All treatments reversed ouabain-related risk-taking behavior and hyperactivity in the open-field test. Ouabain inhibited tricarboxylic acid cycle enzymes in the brain, and valproate and sodium butyrate but not lithium reversed this ouabain-induced dysfunction. Thus, protecting the tricarboxylic acid cycle may contribute to the therapeutic effects of histone deacetylase inhibitors. PMID:25433326

Lopes-Borges, Jéssica; Valvassori, Samira S; Varela, Roger B; Tonin, Paula T; Vieira, Julia S; Gonçalves, Cinara L; Streck, Emilio L; Quevedo, João

2015-01-01

328

The effect of topically applied prostaglandin inhibitors on the laser-induced disruption of the blood aqueous barrier.  

PubMed

The therapeutic effect of topically applied prostaglandin inhibitors on the laser-induced disruption of the blood-aqueous barrier was investigated in six series of five rabbits each. One series was not coagulated and served as baseline, and in a reference group laser coagulation was performed without pretreatment with a prostaglandin inhibitor. In four series the iris laser coagulation of the left eyes was preceded by topical application of a prostaglandin inhibitor. The right eyes served as controls for the contralateral effect on the blood aqueous barrier. After laser coagulation the intraocular pressure was monitored at 10-min intervals, and the anterior chamber was tapped for analysis of the protein concentration and the lactate dehydrogenase activity. Pretreatment with dexamethasone eyedrops and indomethacin eyedrops markedly blocked the laser-induced disruption of the blood-aqueous barrier. The level of protein concentration in the aqueous humor after laser coagulation was much less after pretreatment with dexamethasone or indomethacin eyedrops. The effect was significant, both for the laser-treated eyes and for the noncoagulated fellow eyes (p less than 0.025). The subconjunctival pretreatment with dexamethasone 1 or 24 h before laser coagulation had no significant effect with respect to the protection of the blood aqueous barrier. PMID:4040006

Schrems, W; van Dorp, H P; Mager, S; Krieglstein, G K

1985-04-30

329

Selective serotonin re-uptake inhibitors potentiate gene blunting induced by repeated methylphenidate treatment: Zif268 vs. Homer1a  

PubMed Central

There is a growing use of psychostimulants such as methylphenidate (Ritalin; dopamine reuptake inhibitor) for medical treatments and as cognitive enhancers in the healthy. Methylphenidate is known to produce some addiction-related gene regulation. Recent findings in animal models show that selective serotonin reuptake inhibitors (SSRIs) including fluoxetine can potentiate acute induction of gene expression by methylphenidate, thus indicating an acute facilitatory role for serotonin in dopamine-induced gene regulation. We investigated whether repeated exposure to fluoxetine in conjunction with methylphenidate in adolescent rats facilitated a gene regulation effect well-established for repeated exposure to illicit psychostimulants such as cocaine - blunting (repression) of gene inducibility. We measured, by in situ hybridization histochemistry, the effects of a 5-day repeated treatment with methylphenidate (5 mg/kg), fluoxetine (5 mg/kg) or a combination on the inducibility (by cocaine) of neuroplasticity-related genes (Zif268, Homer1a) in the striatum. Repeated methylphenidate treatment alone produced minimal gene blunting, while fluoxetine alone had no effect. In contrast, fluoxetine added to methylphenidate robustly potentiated methylphenidate-induced blunting for both genes. This potentiation was widespread throughout the striatum, but was most robust in the lateral, sensorimotor striatum, thus mimicking cocaine effects. For illicit psychostimulants, blunting of gene expression is considered part of the molecular basis of addiction. Our results thus suggest that SSRIs such as fluoxetine may increase the addiction liability of methylphenidate. PMID:23763573

Van Waes, Vincent; Vandrevala, Malcolm; Beverley, Joel; Steiner, Heinz

2015-01-01

330

Selective serotonin re-uptake inhibitors potentiate gene blunting induced by repeated methylphenidate treatment: Zif268 versus Homer1a.  

PubMed

There is a growing use of psychostimulants, such as methylphenidate (Ritalin; dopamine re-uptake inhibitor), for medical treatments and as cognitive enhancers in the healthy. Methylphenidate is known to produce some addiction-related gene regulation. Recent findings in animal models show that selective serotonin re-uptake inhibitors (SSRIs), including fluoxetine, can potentiate acute induction of gene expression by methylphenidate, thus indicating an acute facilitatory role for serotonin in dopamine-induced gene regulation. We investigated whether repeated exposure to fluoxetine, in conjunction with methylphenidate, in adolescent rats facilitated a gene regulation effect well established for repeated exposure to illicit psychostimulants such as cocaine-blunting (repression) of gene inducibility. We measured, by in situ hybridization histochemistry, the effects of a 5-day repeated treatment with methylphenidate (5?mg/kg), fluoxetine (5?mg/kg) or a combination on the inducibility (by cocaine) of neuroplasticity-related genes (Zif268, Homer1a) in the striatum. Repeated methylphenidate treatment alone produced minimal gene blunting, while fluoxetine alone had no effect. In contrast, fluoxetine added to methylphenidate robustly potentiated methylphenidate-induced blunting for both genes. This potentiation was widespread throughout the striatum, but was most robust in the lateral, sensorimotor striatum, thus mimicking cocaine effects. For illicit psychostimulants, blunting of gene expression is considered part of the molecular basis of addiction. Our results thus suggest that SSRIs, such as fluoxetine, may increase the addiction liability of methylphenidate. PMID:23763573

Van Waes, Vincent; Vandrevala, Malcolm; Beverley, Joel; Steiner, Heinz

2014-11-01

331

Protective effects of a squalene synthase inhibitor, lapaquistat acetate (TAK-475), on statin-induced myotoxicity in guinea pigs.  

PubMed

High-dose statin treatment has been recommended as a primary strategy for aggressive reduction of LDL cholesterol levels and protection against coronary artery disease. The effectiveness of high-dose statins may be limited by their potential for myotoxic side effects. There is currently little known about the molecular mechanisms of statin-induced myotoxicity. Previously we showed that T-91485, an active metabolite of the squalene synthase inhibitor lapaquistat acetate (lapaquistat: a previous name is TAK-475), attenuated statin-induced cytotoxicity in human skeletal muscle cells [Nishimoto, T., Tozawa, R., Amano, Y., Wada, T., Imura, Y., Sugiyama, Y., 2003a. Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A. Biochem. Pharmacol. 66, 2133-2139]. In the current study, we investigated the effects of lapaquistat administration on statin-induced myotoxicity in vivo. Guinea pigs were treated with either high-dose cerivastatin (1 mg/kg) or cerivastatin together with lapaquistat (30 mg/kg) for 14 days. Treatment with cerivastatin alone decreased plasma cholesterol levels by 45% and increased creatine kinase (CK) levels by more than 10-fold (a marker of myotoxicity). The plasma CK levels positively correlated with the severity of skeletal muscle lesions as assessed by histopathology. Co-administration of lapaquistat almost completely prevented the cerivastatin-induced myotoxicity. Administration of mevalonolactone (100 mg/kg b.i.d.) prevented the cerivastatin-induced myotoxicity, confirming that this effect is directly related to HMG-CoA reductase inhibition. These results strongly suggest that cerivastatin-induced myotoxicity is due to depletion of mevalonate derived isoprenoids. In addition, squalene synthase inhibition could potentially be used clinically to prevent statin-induced myopathy. PMID:17599378

Nishimoto, Tomoyuki; Ishikawa, Eiichiro; Anayama, Hisashi; Hamajyo, Hitomi; Nagai, Hirofumi; Hirakata, Masao; Tozawa, Ryuichi

2007-08-15

332

Novel inhibitors of macrophage migration inhibitory factor prevent cytokine-induced beta cell death.  

PubMed

Macrophage migration inhibitory factor is a multifunctional cytokine involved in the regulation of immune processes and also in apoptosis induction. Elevated MIF expression is detrimental for insulin-producing beta cells and MIF inhibition protected beta cells from several cytotoxic insults such as inflammatory cytokines, high fatty acids or high glucose concentrations. Therefore, the aim of this study was to investigate two newly synthesized small molecule MIF inhibitors (K664-1 and K647-1) and to compare them with previously established effects of the prototypical MIF inhibitor, ISO-1. Our results indicate that K664-1 and K647-1 are 160- and 40-fold more effective in inhibition of MIF?s tautomerase activity than ISO-1. Also, new inhibitors confer beta cell protection from cytokine-triggered apoptosis at significantly lower concentrations than ISO-1. Although all three MIF inhibitors inhibit caspase 3 activity, K664-1 and K647-1 suppress pro-apoptotic BAX protein expression and up-regulate anti-apoptotic Bcl-2 mRNA. Finally, all three MIF inhibitors operate through blockade of nitric oxide production stimulated by cytokines. In conclusion, two novel MIF inhibitors are more potent than ISO-1 and operate through inhibition of the mitochondria-related apoptotic pathway. We propose that these compounds represent a unique class of anti-MIF antagonists that should be further tested for therapeutic use. PMID:24967533

Vujicic, Milica; Nikolic, Ivana; Krajnovic, Tamara; Cheng, Kai-Fan; VanPatten, Sonya; He, Mingzhu; Stosic-Grujicic, Stanislava; Stojanovic, Ivana; Al-Abed, Yousef; Saksida, Tamara

2014-10-01

333

Adr1p-dependent regulation of the oleic acid-inducible yeast gene SPS19 encoding the peroxisomal beta-oxidation auxiliary enzyme 2,4-dienoyl-CoA reductase.  

PubMed

The role of Saccharomyces cerevisiae Adr1p was examined with respect to the transcriptional regulation of the SPS19 gene encoding the peroxisomal beta-oxidation auxiliary enzyme 2,4-dienoyl-CoA reductase. The SPS19 promoter contains both an oleate response element that binds the Pip2p-Oaf1p transcription factor as well as a canonical Adr1p-binding element, termed UAS1(SPS19). Northern analysis demonstrated that transcriptional up-regulation of SPS19 was abolished in cells devoid of Adr1p. Expression of an SPS19-lacZ reporter gene was shown to be quiescent in the adr1Delta mutant and abnormally elevated in cells containing multiple ADR1 copies. UAS1(SPS19) was able to compete for formation of a specific complex between recombinant Adr1p-LacZ and UAS1(CTA1) representing the corresponding Adr1p-binding element in the promoter of the catalase A gene, and to interact directly with this fusion protein. We conclude that in the presence of fatty acids in the medium transcription of SPS19 is directly regulated by both Pip2p-Oaf1p and Adr1p. PMID:11170837

Gurvitz, A; Wabnegger, L; Rottensteiner, H; Dawes, I W; Hartig, A; Ruis, H; Hamilton, B

2000-08-01

334

NOX4 mediates cytoprotective autophagy induced by the EGFR inhibitor erlotinib in head and neck cancer cells  

SciTech Connect

Most head and neck squamous cell carcinomas (HNSCCs) overexpress epidermal growth factor receptor (EGFR) and EGFR inhibitors are routinely used in the treatment of HNSCC. However, many HNSCC tumors do not respond or become refractory to EGFR inhibitors. Autophagy, which is a stress-induced cellular self-degradation process, has been reported to reduce the efficacy of chemotherapy in various disease models. The purpose of this study is to determine if the efficacy of the EGFR inhibitor erlotinib is reduced by activation of autophagy via NOX4-mediated oxidative stress in HNSCC cells. Erlotinib induced the expression of the autophagy marker LC3B-II and autophagosome formation in FaDu and Cal-27 cells. Inhibition of autophagy by chloroquine and knockdown of autophagy pathway genes Beclin-1 and Atg5 sensitized both cell lines to erlotinib-induced cytotoxicity, suggesting that autophagy may serve as a protective mechanism. Treatment with catalase (CAT) and diphenylene iodonium (DPI) in the presence of erlotinib suppressed the increase in LC3B-II expression in FaDu and Cal-27 cells. Erlotinib increased NOX4 mRNA and protein expression by increasing its promoter activity and mRNA stability in FaDu cells. Knockdown of NOX4 using adenoviral siNOX4 partially suppressed erlotinib-induced LC3B-II expression, while overexpression of NOX4 increased expression of LC3B-II. These studies suggest that erlotinib may activate autophagy in HNSCC cells as a pro-survival mechanism, and NOX4 may play a role in mediating this effect. - Highlights: • Erlotinib increased LC3B-II and autophagosome formation in HNSCC cells. • Inhibition of autophagy sensitized HNSCC cells to erlotinib. • Erlotinib increased NOX4 promoter and 3?UTR luciferase activity. • Manipulating NOX4 decreases or increases autophagy.

Sobhakumari, Arya [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Schickling, Brandon M. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Love-Homan, Laurie; Raeburn, Ayanna [Department of Pathology, The University of Iowa, Iowa City, IA (United States); Fletcher, Elise V.M. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Case, Adam J. [Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Domann, Frederick E. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); Miller, Francis J. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); and others

2013-11-01

335

Inhibitors of CLK Protein Kinases Suppress Cell Growth and Induce Apoptosis by Modulating Pre-mRNA Splicing  

PubMed Central

Accumulating evidence has demonstrated the importance of alternative splicing in various physiological processes, including the development of different diseases. CDC-like kinases (CLKs) and serine-arginine protein kinases (SRPKs) are components of the splicing machinery that are crucial for exon selection. The discovery of small molecule inhibitors against these kinases is of significant value, not only to delineate the molecular mechanisms of splicing, but also to identify potential therapeutic opportunities. Here we describe a series of small molecules that inhibit CLKs and SRPKs and thereby modulate pre-mRNA splicing. Treatment with these small molecules (Cpd-1, Cpd-2, or Cpd-3) significantly reduced the levels of endogenous phosphorylated SR proteins and caused enlargement of nuclear speckles in MDA-MB-468 cells. Additionally, the compounds resulted in splicing alterations of RPS6KB1 (S6K), and subsequent depletion of S6K protein. Interestingly, the activity of compounds selective for CLKs was well correlated with the activity for modulating S6K splicing as well as growth inhibition of cancer cells. A comprehensive mRNA sequencing approach revealed that the inhibitors induced splicing alterations and protein depletion for multiple genes, including those involved in growth and survival pathways such as S6K, EGFR, EIF3D, and PARP. Fluorescence pulse-chase labeling analyses demonstrated that isoforms with premature termination codons generated after treatment with the CLK inhibitors were degraded much faster than canonical mRNAs. Taken together, these results suggest that CLK inhibitors exhibit growth suppression and apoptosis induction through splicing alterations in genes involved in growth and survival. These small molecule inhibitors may be valuable tools for elucidating the molecular machinery of splicing and for the potential development of a novel class of antitumor agents. PMID:25581376

Araki, Shinsuke; Dairiki, Ryo; Nakayama, Yusuke; Murai, Aiko; Miyashita, Risa; Iwatani, Misa; Nomura, Toshiyuki; Nakanishi, Osamu

2015-01-01

336

Chloroquine or Chloroquine-PI3K/Akt Pathway Inhibitor Combinations Strongly Promote ?-Irradiation-Induced Cell Death in Primary Stem-Like Glioma Cells  

PubMed Central

We asked whether inhibitors of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, which is highly active in cancer stem cells (CSCs) and upregulated in response to genotoxic treatments, promote ?-irradiation?IR)-induced cell death in highly radioresistant, patient-derived stem-like glioma cells (SLGCs). Surprisingly, in most cases the inhibitors did not promote ?IR-induced cell death. In contrast, the strongly cytostatic Ly294002 and PI-103 even tended to reduce it. Since autophagy was induced we examined whether addition of the clinically applicable autophagy inhibitor chloroquine (CQ) would trigger cell death in SLGCs. Triple therapy with CQ at doses as low as 5 to 10 µM indeed caused strong apoptosis. At slightly higher doses, CQ alone strongly promoted ?IR-induced apoptosis in all SLGC lines examined. The strong apoptosis in combinations with CQ was invariably associated with strong accumulation of the autophagosomal marker LC3-II, indicating inhibition of late autophagy. Thus, autophagy-promoting effects of PI3K/Akt pathway inhibitors apparently hinder cell death induction in ?-irradiated SLGCs. However, as we show here for the first time, the late autophagy inhibitor CQ strongly promotes ?IR-induced cell death in highly radioresistant CSCs, and triple combinations of CQ, ?IR and a PI3K/Akt pathway inhibitor permit reduction of the CQ dose required to trigger cell death. PMID:23091617

Firat, Elke; Weyerbrock, Astrid; Gaedicke, Simone; Grosu, Anca-Ligia; Niedermann, Gabriele

2012-01-01

337

Inducible expression of a fusion gene encoding two proteinase inhibitors leads to insect and pathogen resistance in transgenic rice.  

PubMed

Plant proteinase inhibitors (PIs) are considered as candidates for increased insect resistance in transgenic plants. Insect adaptation to PI ingestion might, however, compromise the benefits received by transgenic expression of PIs. In this study, the maize proteinase inhibitor (MPI), an inhibitor of insect serine proteinases, and the potato carboxypeptidase inhibitor (PCI) were fused into a single open reading frame and introduced into rice plants. The two PIs were linked using either the processing site of the Bacillus thuringiensis Cry1B precursor protein or the 2A sequence from the foot-and-mouth disease virus (FMDV). Expression of each fusion gene was driven by the wound- and pathogen-inducible mpi promoter. The mpi-pci fusion gene was stably inherited for at least three generations with no penalty on plant phenotype. An important reduction in larval weight of Chilo suppressalis fed on mpi-pci rice, compared with larvae fed on wild-type plants, was observed. Expression of the mpi-pci fusion gene confers resistance to C. suppressalis (striped stem borer), one of the most important insect pest of rice. The mpi-pci expression systems described may represent a suitable strategy for insect pest control, better than strategies based on the use of single PI genes, by preventing insect adaptive responses. The rice plants expressing the mpi-pci fusion gene also showed enhanced resistance to infection by the fungus Magnaporthe oryzae, the causal agent of the rice blast disease. Our results illustrate the usefulness of the inducible expression of the mpi-pci fusion gene for dual resistance against insects and pathogens in rice plants. PMID:24237606

Quilis, Jordi; López-García, Belén; Meynard, Donaldo; Guiderdoni, Emmanuel; San Segundo, Blanca

2014-04-01

338

Up-regulation of the Sirtuin 1 (Sirt1) and peroxisome proliferator-activated receptor ? coactivator-1? (PGC-1?) genes in white adipose tissue of Id1 protein-deficient mice: implications in the protection against diet and age-induced glucose intolerance.  

PubMed

Id1, a helix-loop-helix (HLH) protein that inhibits the function of basic HLH E protein transcription factors in lymphoid cells, has been implicated in diet- and age-induced obesity by unknown mechanisms. Here we show that Id1-deficient mice are resistant to a high fat diet- and age-induced obesity, as revealed by reduced weight gain and body fat, increased lipid oxidation, attenuated hepatosteatosis, lower levels of lipid droplets in brown adipose tissue, and smaller white adipocytes after a high fat diet feeding or in aged animals. Id1 deficiency improves glucose tolerance, lowers serum insulin levels, and reduces TNF? gene expression in white adipose tissue. Id1 deficiency also increased expression of Sirtuin 1 and peroxisome proliferator-activated receptor ? coactivator 1?, regulators of mitochondrial biogenesis and energy expenditure, in the white adipose tissue. This effect was accompanied by the elevation of several genes encoding proteins involved in oxidative phosphorylation and fatty acid oxidation, such as cytochrome c, medium-chain acyl-CoA dehydrogenase, and adipocyte protein 2. Moreover, the phenotype for Id1 deficiency was similar to that of mice expressing an E protein dominant-positive construct, ET2, suggesting that the balance between Id and E proteins plays a role in regulating lipid metabolism and insulin sensitivity. PMID:25190816

Zhao, Ying; Ling, Flora; Griffin, Timothy M; He, Ting; Towner, Rheal; Ruan, Hong; Sun, Xiao-Hong

2014-10-17

339

Suppression of MOG- and PLP-Induced Experimental Autoimmune Encephalomyelitis Using a Novel Multivalent Bifunctional Peptide Inhibitor  

PubMed Central

Previously, bifunctional peptide inhibitors (BPI) with a single antigenic peptide have been shown to suppress experimental autoimmune encephalomyelitis (EAE) in an antigen-specific manner. In this study, a multivalent BPI (MVBMOG/PLP) with two antigenic peptides derived from myelin oligodendrocyte glycoprotein (MOG38-50) and myelin proteolipid protein (PLP139-151) was evaluated in suppressing MOG38-50- and PLP139-151-induced EAE. MVBMOG/PLP significantly suppressed both models of EAE even when there was some evidence of epitope spreading in the MOG38-50-induced EAE model. In addition, MVBMOG/PLP was found to be more effective than PLP-BPI and MOG-BPI in suppressing MOG38-50-induced EAE. Thus, the development of MVB molecules with broader antigenic targets can lead to suppression of epitope spreading in EAE. PMID:23911075

Badawi, Ahmed H.; Siahaan, Teruna J.

2013-01-01

340

A critical reflection on the principles of peroxisome formation in yeast  

PubMed Central

We have evaluated the current knowledge on peroxisome proliferation in yeast. In wild-type cells, peroxisomes multiply predominantly by fission at conditions that require peroxisome function(s) for growth. In cells that lack peroxisomes, for instance in pex3 and pex19 mutants or in mutants that display inheritance defects, peroxisomes may form de novo. We propose a novel machinery for the de novo formation of peroxisomes in pex3 cells, in which new peroxisomes do not arise from the endoplasmic reticulum. This machinery is based on the recent observation that membrane vesicles are present in pex3 cells that display peroxisomal characteristics in that they contain specific peroxisomal membrane and matrix proteins. These structures are the source for newly formed peroxisomes upon reintroduction of Pex3. Furthermore, we critically evaluate the principles of sorting of other peroxisomal membrane proteins to their target organelle and the function of the endoplasmic reticulum therein. PMID:24688473

Veenhuis, Marten; van der Klei, Ida J.

2014-01-01

341

Free Fatty Acids Block Glucose-Induced ?-Cell Proliferation in Mice by Inducing Cell Cycle Inhibitors p16 and p18  

PubMed Central

Pancreatic ?-cell proliferation is infrequent in adult humans and is not increased in type 2 diabetes despite obesity and insulin resistance, suggesting the existence of inhibitory factors. Free fatty acids (FFAs) may influence proliferation. In order to test whether FFAs restrict ?-cell proliferation in vivo, mice were intravenously infused with saline, Liposyn II, glucose, or both, continuously for 4 days. Lipid infusion did not alter basal ?-cell proliferation, but blocked glucose-stimulated proliferation, without inducing excess ?-cell death. In vitro exposure to FFAs inhibited proliferation in both primary mouse ?-cells and in rat insulinoma (INS-1) cells, indicating a direct effect on ?-cells. Two of the fatty acids present in Liposyn II, linoleic acid and palmitic acid, both reduced proliferation. FFAs did not interfere with cyclin D2 induction or nuclear localization by glucose, but increased expression of inhibitor of cyclin dependent kinase 4 (INK4) family cell cycle inhibitors p16 and p18. Knockdown of either p16 or p18 rescued the antiproliferative effect of FFAs. These data provide evidence for a novel antiproliferative form of ?-cell glucolipotoxicity: FFAs restrain glucose-stimulated ?-cell proliferation in vivo and in vitro through cell cycle inhibitors p16 and p18. If FFAs reduce proliferation induced by obesity and insulin resistance, targeting this pathway may lead to new treatment approaches to prevent diabetes. PMID:22338094

Pascoe, Jordan; Hollern, Douglas; Stamateris, Rachel; Abbasi, Munira; Romano, Lia C.; Zou, Baobo; O’Donnell, Christopher P.; Garcia-Ocana, Adolfo; Alonso, Laura C.

2012-01-01

342

Free fatty acids block glucose-induced ?-cell proliferation in mice by inducing cell cycle inhibitors p16 and p18.  

PubMed

Pancreatic ?-cell proliferation is infrequent in adult humans and is not increased in type 2 diabetes despite obesity and insulin resistance, suggesting the existence of inhibitory factors. Free fatty acids (FFAs) may influence proliferation. In order to test whether FFAs restrict ?-cell proliferation in vivo, mice were intravenously infused with saline, Liposyn II, glucose, or both, continuously for 4 days. Lipid infusion did not alter basal ?-cell proliferation, but blocked glucose-stimulated proliferation, without inducing excess ?-cell death. In vitro exposure to FFAs inhibited proliferation in both primary mouse ?-cells and in rat insulinoma (INS-1) cells, indicating a direct effect on ?-cells. Two of the fatty acids present in Liposyn II, linoleic acid and palmitic acid, both reduced proliferation. FFAs did not interfere with cyclin D2 induction or nuclear localization by glucose, but increased expression of inhibitor of cyclin dependent kinase 4 (INK4) family cell cycle inhibitors p16 and p18. Knockdown of either p16 or p18 rescued the antiproliferative effect of FFAs. These data provide evidence for a novel antiproliferative form of ?-cell glucolipotoxicity: FFAs restrain glucose-stimulated ?-cell proliferation in vivo and in vitro through cell cycle inhibitors p16 and p18. If FFAs reduce proliferation induced by obesity and insulin resistance, targeting this pathway may lead to new treatment approaches to prevent diabetes. PMID:22338094

Pascoe, Jordan; Hollern, Douglas; Stamateris, Rachel; Abbasi, Munira; Romano, Lia C; Zou, Baobo; O'Donnell, Christopher P; Garcia-Ocana, Adolfo; Alonso, Laura C

2012-03-01

343

The cathepsin B inhibitor, z-FA-CMK is toxic and readily induced cell death in human T lymphocytes  

SciTech Connect

The cathepsin B inhibitor, benzyloxycarbonyl-phenylalanine-alanine-chloromethylketone (z-FA-CMK) was found to be toxic and readily induced cell death in the human T cell line, Jurkat, whereas two other analogs benzyloxycarbonyl-phenylalanine-alanine-fluoromethylketone (z-FA-FMK) and benzyloxycarbonyl-phenylalanine-alanine-diazomethylketone (z-FA-DMK) were not toxic. The toxicity of z-FA-CMK requires not only the CMK group, but also the presence of alanine in the P1 position and the benzyloxycarbonyl group at the N-terminal. Dose–response studies showed that lower concentrations of z-FA-CMK induced apoptosis in Jurkat T cells whereas higher concentrations induced necrosis. In z-FA-CMK-induced apoptosis, both initiator caspases (-8 and -9) and effector caspases (-3, -6 and -7) were processed to their respective subunits in Jurkat T cells. However, only the pro-form of the initiator caspases were reduced in z-FA-CMK-induced necrosis and no respective subunits were apparent. The caspase inihibitor benzyloxycarbonyl-valine-alanine-aspartic acid-(O-methyl)-fluoromehylketone (z-VAD-FMK) inhibits apoptosis and caspase processing in Jurkat T cells treated with low concentration of z-FA-CMK but has no effect on z-FA-CMK-induced necrosis and the loss of initiator caspases. This suggests that the loss of initiator caspases in Jurkat T cells during z-FA-CMK-induced necrosis is not a caspase-dependent process. Taken together, we have demonstrated that z-FA-CMK is toxic to Jurkat T cells and induces apoptosis at low concentrations, while at higher concentrations the cells die of necrosis. - Highlights: • z-FA-CMK is toxic and induce cell death in the human T cells. • z-FA-CMK toxicity requires the CMK group, alanine and the benzyloxycarbonyl group. • z-FA-CMK induced apoptosis at low concentration and necrosis at high concentration.

Liow, K.Y.; Chow, S.C., E-mail: chow.sek.chuen@monash.edu

2013-11-01

344

Paradoxical Regulation of Hypoxia Inducible Factor-1? (HIF-1?) by Histone Deacetylase Inhibitor in Diffuse Large B-Cell Lymphoma  

PubMed Central

Hypoxia inducible factor (HIF) is important in cancer, as it regulates various oncogenic genes as well as genes involved in cell survival, proliferation, and migration. Elevated HIF-1 protein promotes a more aggressive tumor phenotype, and greater HIF-1 expression has been demonstrated to correlate with poorer prognosis, increased risk of metastasis and increased mortality. Recent reports suggest that HIF-1 activates autophagy, a lysosomal degradation pathway which may promote tumor cell survival. We show here that HIF-1? expression is constitutively active in multiple diffuse large B cell lymphoma (DLBCL) cell lines under normoxia and it is regulated by the PI3K/AKT pathway. PCI-24781, a pan histone deacetylase inhibitor (HDACI), enhanced accumulation of HIF-1? and induced autophagy initially, while extended incubation with the drug resulted in inhibition of HIF-1?. We tested the hypothesis that PCI-24781- induced autophagy is mediated by HIF-1? and that inhibition of HIF-1? in these cells results in attenuation of autophagy and decreased survival. We also provide evidence that autophagy serves as a survival pathway in DLBCL cells treated with PCI-24781 which suggests that the use of autophagy inhibitors such as chloroquine or 3-methyl adenine in combination with PCI-24781 may enhance apoptosis in lymphoma cells. PMID:24312289

Bhalla, Savita; Evens, Andrew M.; Prachand, Sheila; Schumacker, Paul T.; Gordon, Leo I.

2013-01-01

345

Tyrosine kinase inhibitor Thiotanib targets Bcr-Abl and induces apoptosis and autophagy in human chronic myeloid leukemia cells.  

PubMed

Chronic myeloid leukemia (CML) is characterized by abnormal Bcr and Abl genes and enhanced tyrosine kinase activity. Anti-CML therapy has been much improved along with the applications of tyrosine kinase inhibitors (TKIs) which selectively target Bcr-Abl and have a cytotoxic effect on CML. Recently, four-membered heterocycles as "compact modules" have attracted much interest in drug discovery. Grafting these small four-membered heterocycles onto a molecular scaffold could probably provide compounds that retain notable activity and populate chemical space otherwise not previously accessed. Accordingly, a novel TKI, Thiotanib, has been designed and synthesized. It selectively targets Bcr-Abl, inducing growth inhibition, cell cycle arrest, and apoptosis of CML cells. Meanwhile, the compound Thiotanib could also induce autophagy in CML cells. Interestingly, inhibition of autophagy promotes Thiotanib-induced apoptosis with no further activation of caspase 3, while inhibition of caspases did not affect the cell survival of CML cells. Moreover, the compound Thiotanib could inhibit phosphorylation of Akt and mTOR, increase beclin-1 and Vps34, and block the formation of the Bcl-2 and Beclin-1 complex. This indicates the probable pathway of autophagy initiation. Our results highlight a new approach for TKI reforming and further provide an indication of the efficacy enhancement of TKIs in combination with autophagy inhibitors. PMID:25200837

Fan, Jiajun; Dong, Xiaochun; Zhang, Weixing; Zeng, Xian; Li, Yubin; Sun, Yun; Wang, Shaofei; Wang, Ziyu; Gao, Hongjian; Zhao, Weili; Ju, Dianwen

2014-12-01

346

KN-93, A CaMKII inhibitor, suppresses ventricular arrhythmia induced by LQT2 without decreasing TDR.  

PubMed

Abnormal enhanced transmural dispersion of repolarization (TDR) plays an important role in the maintaining of the severe ventricular arrhythmias such as torsades de pointes (TDP) which can be induced in long-QT (LQT) syndrome. Taking advantage of an in vitro rabbit model of LQT2, we detected the effects of KN-93, a CaM-dependent kinase (CaMK) II inhibitor on repolarization heterogeneity of ventricular myocardium. Using the monophasic action potential recording technique, the action potentials of epicardium and endocardium were recorded in rabbit cardiac wedge infused with hypokalemic, hypomagnesaemic Tyrode's solution. At a basic length (BCL) of 2000 ms, LQT2 model was successfully mimicked with the perfusion of 0.5 ?mol/L E-4031, QT intervals and the interval from the peak of T wave to the end of T wave (Tp-e) were prolonged, and Tp-e/QT increased. Besides, TDR was increased and the occurrence rate of arrhythmias like EAD, R-on-T extrasystole, and TDP increased under the above condition. Pretreatment with KN-93 (0.5 ?mol/L) could inhibit EAD, R-on-T extrasystole, and TDP induced by E-4031 without affecting QT interval, Tp-e, and Tp-e/QT. This study demonstrated KN-93, a CaMKII inhibitor, can inhibit EADs which are the triggers of TDP, resulting in the suppression of TDP induced by LQT2 without affecting TDR. PMID:24142712

Wang, Wen-long; Zhang, Shuang-shuang; Deng, Jie; Zhao, Jun-yan; Zhao, Chong-qiang; Lin, Li; Zhang, Cun-tai; Lv, Jia-gao

2013-10-01

347

The DNA methyltransferase inhibitor zebularine induces mitochondria-mediated apoptosis in gastric cancer cells in vitro and in vivo  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Zebularine inhibited cell growth of gastric cancer in a time- and dose-dependent manner. Black-Right-Pointing-Pointer Chromatin condensation and nuclear fragmentation were induced. Black-Right-Pointing-Pointer Zebularine promoted apoptosis via mitochondrial pathways. Black-Right-Pointing-Pointer Tumorigenicity was inhibited by zebularine. -- Abstract: DNA methyltransferase (DNMT) inhibitor zebularine has been reported to potentiate the anti-tumor effect by reactivating the expression of tumor suppressor genes and apoptosis-related genes in various malignant cells. However, the apoptotic signaling pathway in gastric cancer cells induced by zebularine is not well understood. In the study, the effects of zebularine on the growth and apoptosis of gastric cancer cells were investigated by MTT assay, Hoechst assay, Western blot analysis, flow cytometric analysis of annexin V-FITC/PI staining, and TUNEL assay. Zebularine was an effective inhibitor of human gastric cancer cells proliferation in vitro and in vivo. The effects were dose dependent. A zebularine concentration of 50 {mu}M accounted for the inhibition of cell proliferation of 67% at 48 h. The treatment with zebularine upregulated Bax, and decreased Bcl-2 protein. Caspase-3 was activated, suggesting that the apoptosis is mediated by mitochondrial pathways. Moreover, zebularine injection successfully inhibited the tumor growth via apoptosis induction which was demonstrated by TUNEL assay in xenograft tumor mouse model. These results demonstrated that zebularine induced apoptosis in gastric cancer cells via mitochondrial pathways, and zebularine might become a therapeutic approach for the treatment of gastric cancer.

Tan, Wei, E-mail: polo5352877@163.com [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan (China)] [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan (China); Zhou, Wei; Yu, Hong-gang; Luo, He-Sheng; Shen, Lei [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan (China)] [Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan (China)

2013-01-04

348

Potential of protease inhibitor in 3-nitropropionic acid induced Huntington's disease like symptoms: Mitochondrial dysfunction and neurodegeneration.  

PubMed

Huntington's disease (HD) is a genetic, neurodegenerative disorder mainly characterized by motor dysfunction, cognitive decline and psychiatric disturbances. 3-Nitropropionic acid (3-NP) is an inhibitor of succinate dehydrogenase (Complex II) of the mitochondrial respiratory chain, which thereby reduces production of ATP. It induces neurotoxicity by causing striatal degeneration, energy deficit and oxidative stress. Angiotensin converting enzyme (ACE) is an important protease in the renin angiotensin system (RAS) responsible for the conversion of Angiotensin I to Angiotensin II. Angiotensin-II stimulates mitochondrial oxidant release leading to depression of energy metabolism. ACE inhibitors have shown promise in disorders like stress, anxiety, and depression in addition to showing beneficial effects in cognitive disorders like Alzheimer's. Angiotensin-II inhibition enhances energy production by lowering mitochondrial oxidant production, and hence protects mitochondrial structure. Trandolapril is a centrally active ACE inhibitor. 3-NP administered systematically (20mg/kg, i.p) for 4 days consecutively induced HD like symptoms - loss of body weight, neurobehavioral alterations like memory dysfunction (elevated plus maze, Morris water maze performance), Hind-limb impairment (Narrow beam test), motor incoordination (locomotor activity). Biochemical studies on brain tissue showed increased lipid peroxidation, nitrite levels and acetylcholinesterase activity along with decreased levels of reduced glutathione, catalase activity. Mitochondrial enzyme complex activities (I, II, IV and MTT assay) were found to be significantly lowered in brain mitochondria. Administration of Trandolapril (4 and 6mg/kg, p.o) daily for 12 days showed significant improvement in body weight, neurobehavioral parameters, oxidative stress and mitochondrial enzyme activities in rat brain. These findings were further confirmed by histopathological studies which showed improvement in 3-NP induced brain lesions. This study indicates that Trandolapril could be an effective treatment option for the management of HD. PMID:25445565

Hariharan, Ashwini; Shetty, Shruthi; Shirole, Trupti; Jagtap, Aarti G

2014-12-01

349

Bacillus Calmette-Guérin vaccine induces a selective serotonin reuptake inhibitor (SSRI)-resistant depression like phenotype in mice.  

PubMed

Preclinical studies have shown that administration of Bacillus Calmette-Guérin (BCG) vaccine induces depression-like behaviors in mice; however, the effect of antidepressant drug treatment has not been reported earlier. In the present study, we induced depression-like behavior by administering BCG vaccine to BALB/c mice. BCG treatment produced robust serum sickness as shown by a decrease in body weight, reduced spontaneous locomotor activity and reduced voluntary wheel running activity. BCG treatment also elevated plasma IL6 and IFN? levels and produced a marked activation of lung IDO activity. At a time point when serum sickness-related behaviors had fully recovered (i.e., day 14) BCG-treated mice showed a significant increase in immobility in the forced swim test (FST) and tail suspension test (TST) indicative of a pro-depressant phenotype. We observed significant increase in [(3)H]PK11195 binding in cortex and hippocampus regions of BGC-treated mice in comparison to saline-treated mice indicating prominent neuroinflammation. Pharmacological evaluation of FST behavior in BCG-treated mice demonstrated selective resistance to the selective serotonin reuptake inhibitors (SSRIs) fluoxetine and escitalopram. In contrast the tricyclic antidepressant imipramine, the dual serotonin/norepinephrine reuptake inhibitor (SNRI) duloxetine, and the dual dopamine/norepinephrine reuptake inhibitor (DNRI) nomifensine retained antidepressant efficacy in these mice. The lack of efficacy with acute treatment with SSRIs could not be explained either by differences in drug exposure or serotonin transporter (SERT) occupancy. Our results demonstrate that BCG-vaccine induced depression like behavior is selectively resistant to SSRIs and could potentially be employed to evaluate novel therapeutic agents being developed to treat SSRI-resistance in humans. PMID:25016199

Vijaya Kumar, K; Rudra, Anjuman; Sreedhara, M V; Siva Subramani, T; Prasad, Durga Shiva; Das, Manish Lal; Murugesan, Senthil; Yadav, Rajbharan; Trivedi, Ravi Kumar; Louis, Justin V; Li, Yu-Wen; Bristow, Linda J; Naidu, Pattipati S; Vikramadithyan, Reeba Kannimel

2014-11-01

350

An Aminopyridazine Inhibitor of Death Associated Protein Kinase Attenuates Hypoxia-Ischemia Induced Brain Damage  

SciTech Connect

Death associated protein kinase (DAPK) is a calcium and calmodulin regulated enzyme that functions early in eukaryotic programmed cell death, or apoptosis. To validate DAPK as a potential drug discovery target for acute brain injury, the first small molecule DAPK inhibitor was synthesized and tested in vivo. A single injection of the aminopyridazine-based inhibitor administered 6 h after injury attenuated brain tissue or neuronal biomarker loss measured, respectively, 1 week and 3 days later. Because aminopyridazine is a privileged structure in neuropharmacology, we determined the high-resolution crystal structure of a binary complex between the kinase domain and a molecular fragment of the DAPK inhibitor. The co-crystal structure describes a structural basis for interaction and provides a firm foundation for structure-assisted design of lead compounds with appropriate molecular properties for future drug development.

Velentza, A.V.; Wainwright, M.S.; Zasadzki, M.; Mirzoeva, S.; Haiech, J.; Focia, P.J.; Egli, M.; Watterson, D.M.

2010-03-08

351

Fate and role of peroxisomes during the life cycle of the yeast Saccharomyces cerevisiae: inheritance of peroxisomes during meiosis.  

PubMed

Sporulation in the yeast Saccharormyces cerevisiae is a meiotic developmental process that occurs in MATa/MATalpha heterozygotes in response to nutrient deprivation. Here, the fate and role of peroxisomes during sporulation and germination has been examined by a combination of immunoelectron microscopy and the use of pex mutants defective in peroxisomal functions. Using a green fluorescent protein probe targeted to peroxisomes we show that peroxisomes are inherited through meiosis and that they do not increase in number either during sporulation or spore germination. In addition, there is no requirement for peroxisome degradation prior to spore packaging. Unlike the situation in filamentous fungi, peroxisomes do not proliferate during the yeast life cycle. Functional peroxisomes are dispensable for efficient meiotic development on acetate medium since homozygous delta pex6 diploids sporulated well and produced mature spores that were resistant to diethyl ether. Like haploids, diploid cells can proliferate their peroxisomes in response to oleate as sole carbon source in liquid medium, but under these conditions they do not sporulate. On solid oleate medium, homozygous pex5, delta pex6, and pex7 cells were unable to sporulate efficiently, whereas the wild type was. The results presented here are discussed in terms of the transmission of organelles to progeny cells. PMID:9681685

Gurvitz, A; Rottensteiner, H; Hamilton, B; Ruis, H; Hartig, A; Dawes, I W; Binder, M

1998-07-01

352

The role of poly(ADP-ribose) polymerase-1 inhibitor in carrageenan-induced lung inflammation in mice.  

PubMed

Increasing indication is unveiling a role for poly(ADP-ribose) polymerase (PARP)-1 in the regulation of inflammatory/immune responses. The aim of the present study was to determine the potential anti-inflammatory effects of PARP-1 inhibitor 5-aminoisoquinolinone (5-AIQ) to explore the role of PARP-1 inhibitor in a mouse model of carrageenan-induced lung inflammation. A single dose of 5-AIQ (1.5mg/kg) was administered intraperitoneally (i.p.) 1h before ?-carrageenan (Cg) administration. We assessed the effects of 5-AIQ treatment on CD25(+), GITR(+), CD25(+)GITR(+), IL-17(+) and Foxp3(+) cells which were investigated using flowcytometry in pleural exudates and heparinized blood. We also evaluated mRNA expressions of IL-6, TNF-?, IL-1?, IL-10, CD11a, l-selectin (CD62L), ICAM-1, MCP-1, iNOS and COX-2 in the lung tissue. We further examined the effects of 5-AIQ on the key mediators of inflammation, namely COX-2, STAT-3, NF-kB p65, PARP-1, IkB-? and IL-4 protein expression in the lung tissue using western blotting. The results illustrated that the numbers of T cell subsets, IL-17(+) cytokine levels were markedly increased and Foxp3(+) production decreased in the Cg group. Furthermore, Cg-induced up-regulation of adhesion molecules, pro-inflammatory mediators and chemokine expressions. Western blot analysis revealed an increased protein expressions of COX-2, STAT-3 NF-kB p65 and PARP-1 and decreased IkB-? and IL-4 in the Cg group. PARP-1 inhibitor via 5-AIQ treatment reverses the action significantly of all the previously mentioned effects. Moreover, histological examinations revealed anti-inflammatory effects of 5-AIQ, whereas Cg-group aggravated Cg-induced inflammation. Present findings demonstrate the potent anti-inflammatory action of the PARP-1 inhibitor in acute lung injury induced by carrageenan. PMID:25304310

Ahmad, Sheikh Fayaz; Zoheir, Khairy M A; Ansari, Mushtaq Ahmad; Korashy, Hesham M; Bakheet, Saleh A; Ashour, Abdelkader E; Al-Shabanah, Othman A; Al-Harbi, Mohammed M; Attia, Sabry M

2015-02-01

353

The proton pump inhibitor inhibits cell growth and induces apoptosis in human hepatoblastoma  

Microsoft Academic Search

Purpose  In normal physiology, a vacuolar-type proton pump (V-ATPase) maintains an intracellular acid microenvironment in lysosome,\\u000a endosome, and other endomembrane systems. Cancer cells overexpress V-ATPase compared with normal cells, and disturbances of\\u000a the acid environment are thought to significantly impact the cancer cell infiltration and growth. Bafilomycin A1 (Baf-A1)\\u000a is a specific inhibitor of the proton-pump inhibitor (PPI) V-ATPase. Neoplastic cells

Toshiya Morimura; Keiko Fujita; Masumi Akita; Masabumi Nagashima; Akira Satomi

2008-01-01

354

Reversible acute encephalopathy with mutism, induced by calcineurin inhibitors after renal transplantation.  

PubMed

The incidence of neurotoxicity from calcineurin inhibitors varies by the organ transplanted. Akinetic mutism is characterized by the inability to perform voluntary movements and express language, without alterations in mental status. This process has been reported in neurotoxicity due to high serum levels of calcineurin inhibitors, but in rare cases, it presents as a form of tacrolimus toxicity after renal transplantation, despite normal serum levels. We report a clinical case of a renal transplant patient in whom reversible acute encephalopathy and akinetic mutism developed. Brain lesions appeared on magnetic resonance imaging, and the condition resolved after the drug was withdrawn. PMID:22252846

Toledo Perdomo, Katia; Navarro Cabello, María-Dolores; Pérez Sáez, María-José; Ramos Pérez, Manuel José; Agüera Morales, Maria Luisa; Aljama García, Pedro

2012-01-01

355

Expression of the Serpin Serine Protease Inhibitor 6 Protects Dendritic Cells from Cytotoxic T Lymphocyte–Induced Apoptosis  

PubMed Central

Dendritic cells (DCs) play a central role in the immune system as they drive activation of T lymphocytes by cognate interactions. However, as DCs express high levels of major histocompatibility complex class I, this intimate contact may also result in elimination of DCs by activated cytotoxic T lymphocytes (CTLs) and thereby limit induction of immunity. We show here that immature DCs are indeed susceptible to CTL-induced killing, but become resistant upon maturation with anti-CD40 or lipopolysaccharide. Protection is achieved by expression of serine protease inhibitor (SPI)-6, a member of the serpin family that specifically inactivates granzyme B and thereby blocks CTL-induced apoptosis. Anti-CD40 and LPS-induced SPI-6 expression is sustained for long periods of time, suggesting a role for SPI-6 in the longevity of DCs. Importantly, T helper 1 cells, which mature DCs and boost CTL immunity, induce SPI-6 expression and subsequent DC resistance. In contrast, T helper 2 cells neither induce SPI-6 nor convey protection, despite the fact that they trigger DC maturation with comparable efficiency. Our data identify SPI-6 as a novel marker for DC function, which protects DCs against CTL-induced apoptosis. PMID:11535633

Medema, Jan Paul; Schuurhuis, Danita H.; Rea, Delphine; van Tongeren, Joost; de Jong, Joan; Bres, Sandra A.; Laban, Sandra; Toes, René E.M.; Toebes, Mireille; Schumacher, Ton N.M.; Bladergroen, Bellinda A.; Ossendorp, Ferry; Kummer, J. Alain; Melief, Cornelis J.M.; Offringa, Rienk

2001-01-01

356

Proteome Analysis of Peroxisomes from Etiolated Arabidopsis Seedlings Identifies a Peroxisomal Protease Involved in ?-Oxidation and Development1[C][W][OPEN  

PubMed Central

Plant peroxisomes are highly dynamic organelles that mediate a suite of metabolic processes crucial to development. Peroxisomes in seeds/dark-grown seedlings and in photosynthetic tissues constitute two major subtypes of plant peroxisomes, which had been postulated to contain distinct primary biochemical properties. Multiple in-depth proteomic analyses had been performed on leaf peroxisomes, yet the major makeup of peroxisomes in seeds or dark-grown seedlings remained unclear. To compare the metabolic pathways of the two dominant plant peroxisomal subtypes and discover new peroxisomal proteins that function specifically during seed germination, we performed proteomic analysis of peroxisomes from etiolated Arabidopsis (Arabidopsis thaliana) seedlings. The detection of 77 peroxisomal proteins allowed us to perform comparative analysis with the peroxisomal proteome of green leaves, which revealed a large overlap between these two primary peroxisomal variants. Subcellular targeting analysis by fluorescence microscopy validated around 10 new peroxisomal proteins in Arabidopsis. Mutant analysis suggested the role of the cysteine protease RESPONSE TO DROUGHT21A-LIKE1 in ?-oxidation, seed germination, and growth. This work provides a much-needed road map of a major type of plant peroxisome and has established a basis for future investigations of peroxisomal proteolytic processes to understand their roles in development and in plant interaction with the environment. PMID:24130194

Quan, Sheng; Yang, Pingfang; Cassin-Ross, Gaëlle; Kaur, Navneet; Switzenberg, Robert; Aung, Kyaw; Li, Jiying; Hu, Jianping

2013-01-01

357

HDAC inhibitors mitigate ischemia-induced oligodendrocyte damage: potential roles of oligodendrogenesis, VEGF, and anti-inflammation  

PubMed Central

White matter injury is an important component of stroke pathology, but its pathophysiology and potential treatment remain relatively elusive and underexplored. We previously reported that after permanent middle cerebral artery occlusion (pMCAO), sodium butyrate (SB) and trichostatin A (TSA) induced neurogenesis via histone deacetylase (HDAC) inhibition in multiple ischemic brain regions in rats; these effects-which depended on activation of brain-derived neurotrophic factor (BDNF)-TrkB signaling-contributed to behavioral improvement. The present study found that SB or TSA robustly protected against ischemia-induced loss of oligodendrocytes detected by confocal microscopy of myelin basic protein (MBP) immunostaining in the ipsilateral subventricular zone (SVZ), striatum, corpus callosum, and frontal cortex seven days post-pMCAO. Co-localization of 5-bromo-2’-deoxyuridine (BrdU)+ and MBP+ cells after SB treatment suggested the occurrence of oligodendrogenesis. SB also strongly upregulated vascular endothelial growth factor (VEGF), which plays a major role in neurogenesis, angiogenesis, and functional recovery after stroke. These SB-induced effects were markedly suppressed by blocking the TrkB signaling pathway with K252a. pMCAO-induced activation of microglia (OX42+) and macrophages/monocytes (ED1+)-which has been linked to white matter injury-was robustly suppressed by SB in a K252a-sensitive manner. In addition, SB treatment largely blocked caspase-3+ and OX42+ cells in ipsilateral brain regions. Our results suggest that HDAC inhibitor-mediated protection against ischemia-induced oligodendrocyte loss may involve multiple mechanisms including oligodendrogenesis, VEGF upregulation, anti-inflammation, and caspase-3 downregulation. Taken together, the results suggest that post-insult treatment with HDAC inhibitors is a rational strategy to mitigate white matter injury following ischemic stroke. PMID:24936215

Kim, Hyeon Ju; Chuang, De-Maw

2014-01-01

358

Effects of a lipoxygenase inhibitor on digoxin-induced cardiac arrhythmias in the isolated perfused guinea-pig heart.  

PubMed

1. The effects of a lipoxygenase inhibitor, BW A4C, on digoxin-induced arrhythmias and cardiac dynamics (contractile force, perfusion pressure, heart rate) were investigated in Langendorff-perfused isolated guinea-pig hearts. In the control group, arrhythmias were induced by 25 micrograms/ml digoxin at a perfusion rate of 0.5 ml/min. In the treated groups, BW A4C (1 and 0.3 microM) perfused continuously from 15 min prior to digoxin until cardiac arrest occurred. Digoxin exposure (microgram/g wet weight of heart) for the occurrence of arrhythmias and cardiac arrest were the parameters evaluated to assess cardiotoxicity. 2. Digoxin caused a marked increase in leukotriene B4 release in the coronary effluent, and was collected during tachyarrhythmias. BW A4C markedly inhibited the digoxin-induced elevation of LTB4. 3. BW A4C (1 and 0.3 microM) did not prevent the onset of ventricular fibrillation and ventricular tachycardia despite a slight delay in the occurrence of ventricular fibrillation and cardiac arrest at the 0.3 microM concentration. 4. Contractile force increased significantly after digoxin infusion which was concomitant with the time of onset of arrhythmias. In the presence of BW A4C, the contractile force increased, but not significantly. Perfusion pressure increased initially after digoxin infusion in the absence and the presence of BW A4C, but not significantly. 5. These findings show that the lipoxygenase inhibitor lacked any protective action on digoxin-induced arrhythmias despite its effective suppression of digoxin-induced elevation of LTB4 in coronary effluent. PMID:9347327

Gök, S; Ulker, S; Hüseyinov, A; Evinç, A

1997-11-01

359

Anisodamine Counteracts Lipopolysaccharide-Induced Tissue Factor and Plasminogen Activator Inhibitor1 Expression in Human Endothelial Cells: Contribution of the NF-?B Pathway  

Microsoft Academic Search

In this study we aimed to investigate whether the therapeutic efficacy of anisodamine in the treatment of bacteraemic shock could – at least in part – be brought about by its direct interference with the lipopolysaccharide (LPS)-induced activation of endothelial cells. Thus, we investigated the effect of anisodamine on LPS-induced expression of plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF),

Qiu-Rong Ruan; Wei-Jian Zhan g; Peter Hufnagl; Christoph Kaun; Bernd R. Binder; Johann Wojta

2001-01-01

360

Identification of Novel Plant Peroxisomal Targeting Signals by a Combination of Machine Learning Methods and in Vivo Subcellular Targeting Analyses[W  

PubMed Central

In the postgenomic era, accurate prediction tools are essential for identification of the proteomes of cell organelles. Prediction methods have been developed for peroxisome-targeted proteins in animals and fungi but are missing specifically for plants. For development of a predictor for plant proteins carrying peroxisome targeting signals type 1 (PTS1), we assembled more than 2500 homologous plant sequences, mainly from EST databases. We applied a discriminative machine learning approach to derive two different prediction methods, both of which showed high prediction accuracy and recognized specific targeting-enhancing patterns in the regions upstream of the PTS1 tripeptides. Upon application of these methods to the Arabidopsis thaliana genome, 392 gene models were predicted to be peroxisome targeted. These predictions were extensively tested in vivo, resulting in a high experimental verification rate of Arabidopsis proteins previously not known to be peroxisomal. The prediction methods were able to correctly infer novel PTS1 tripeptides, which even included novel residues. Twenty-three newly predicted PTS1 tripeptides were experimentally confirmed, and a high variability of the plant PTS1 motif was discovered. These prediction methods will be instrumental in identifying low-abundance and stress-inducible peroxisomal proteins and defining the entire peroxisomal proteome of Arabidopsis and agronomically important crop plants. PMID:21487095

Lingner, Thomas; Kataya, Amr R.; Antonicelli, Gerardo E.; Benichou, Aline; Nilssen, Kjersti; Chen, Xiong-Yan; Siemsen, Tanja; Morgenstern, Burkhard; Meinicke, Peter; Reumann, Sigrun

2011-01-01

361

The Effect of Serine Protease Inhibitors on Airway Inflammation in a Chronic Allergen-Induced Asthma Mouse Model  

PubMed Central

Serine protease inhibitors reportedly attenuated airway inflammation and had antioxidant in multiorgan. However, the effects of the serine protease inhibitors nafamostat mesilate (FUT), gabexate mesilate (FOY), and ulinastatin (UTI) on a long-term challenged mouse model of chronic asthma are unclear. BALB/c mice (6 mice/group) were intratracheally inoculated with five doses of Dermatophagoides pteronyssinus (Der p; 50??L, 1?mg/mL) at one-week intervals. Therapeutic doses of FUT (0.0625?mg/kg), FOY (20?mg/kg), or UTI (10,000?U/kg) were, respectively, injected intraperitoneally into these mice. Control mice received sterile PBS. At 3 days after the last challenge, mice were sacrificed to assess airway hyperresponsiveness (AHR), remodeling, and inflammation; lung histological features; and cytokine expression profiles. Compared with untreated controls, mice treated with FUT, FOY, and UTI had decreased AHR and goblet cell hyperplasia, decreased eosinophil and neutrophil infiltration, decreased Der p-induced IL-4 levels in serum and IL-5, IL-6, IL-13, and IL-17 levels in bronchoalveolar lavage fluid, and inhibited nuclear factor (NF)-?B activity in lung tissues. The serine protease inhibitors FUT, FOY, and UTI have potential therapeutic benefits for treating asthma by downregulating Th2 cytokines and Th17 cell function and inhibiting NF-?B activation in lung tissue. PMID:25180025

Lin, Li-Jen; Wang, Shulhn-Der; Chiang, Chung-Jen; Kao, Shung-Te

2014-01-01

362

Novel inhibitors are cytotoxic for myeloma cells with NFkB inducing kinase-dependent activation of NFkB  

PubMed Central

NFkB activity is critical for survival and proliferation of normal lymphoid cells and many kinds of B-cell tumors, including multiple myeloma (MM). NFkB activating mutations, which are apparent progression events, enable MM tumors to become less dependent on bone marrow signals that activate NFkB. Mutations that activate NFkB-inducing kinase (NIK) protein are the most prevalent among the many kinds of NFkB mutations in MM tumors. NIK is the main activating kinase of the alternative NFkB pathway, although over-expression of NIK also can activate the classical pathway. Two NIK inhibitors and an isomeric control were tested with human myeloma cell lines. These specific NIK inhibitors are selectively cytotoxic for cells with NIK-dependent activation of NFkB. Combination therapy targeting NIK and IKKbeta (as a main kinase of the classical NFkB pathway) represents a promising treatment strategy in MM. NIK inhibitors can also be useful tool for assessing the role of NIK and alternative NFkB pathway in different cells. PMID:24980832

Demchenko, Yulia N.; Brents, Leslie A.; Li, Zhihong; Bergsagel, Leif P.; McGee, Lawrence R.; Kuehl, Michael W.

2014-01-01