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4-MU synergistically kills cancer cells with TRAIL and suppresses reversal of cells from TRAIL-induced apoptosis / CUHK electronic theses & dissertations collectionJanuary 2015 (has links)
TRAIL has been widely investigated as an anti-cancer agent due to its high efficacy in vitro and its safety to normal cells. However, TRAIL-based agents only showed modest effect in clinical studies because of TRAIL resistance. In addition to apoptosis, TRAIL has also been reported to promote pro-survival signalings, cell migration and metastasis. One of the current strategies in the development of TRAIL-based therapeutics focuses on the search of sensitizing agents that help overcome TRAIL resistance without increasing harm to normal cells. / This study reports a novel combination of TRAIL and 4-methylumbelliferone (4-MU) which can kill HeLa cells and HepG2 cells synergistically without cytotoxicity to Hs68 non-tumorigenic cells. This combination also effectively inhibited cancer cell proliferation and potentiated apoptosis by accumulation of tBid, down-regulation of anti-apoptotic proteins and inhibition of Akt. More importantly, 4-MU could suppress the recovery of HeLa cells from TRAIL-induced apoptosis, a process previously implicated to be associated with cancer relapse and tumor heterogeneity. This study has provided solid evidences substantiating further research on TRAIL-4-MU combination. / 腫瘤壞死因子相關凋亡誘導配體 (TRAIL) 在體外實驗中有良好抗癌作用,且不會傷害正常細胞,使之得到廣泛研究,成為近年熱門的新抗癌分子。然而TRAIL 在臨床實驗中並沒有顯著抗癌功效,一般認為人體腫瘤細胞對TRAIL 具有耐藥性。研究文獻亦指出,除了細胞凋亡外,TRAIL亦會誘發細胞存活機制、促進細胞移行及癌細胞轉移。目前,對於TRAIL相關藥品抗癌作用的研究有幾個大方向,其中之一就是尋找良好的增敏分子。良好的增敏分子應能夠增力癌細胞對TRAIL的敏感性,對抗癌細胞對TRAIL的耐藥性,同時不能殺傷正常細胞。 / 本研究揭示了一個全新的抗癌藥物聯合。當TRAIL聯合4-甲基伞形酮(4-MU)能產生協同作用,殺傷HeLa癌細胞和HepG2癌細胞而不會傷害Hs68正常細胞。此組合能有效抑制癌細胞生長,並透過增加tBid蛋白表達、減少抗凋亡蛋白表達及抑制Akt來促進細胞凋亡。更為重要的是,4-MU能抑制HeLa癌細胞自TRAIL誘導凋亡的恢復和逆轉。而癌細胞凋亡逆轉一般被視為與癌症復發及腫瘤多樣性有關。本研究提供了實質證據,支持對TRAIL-4-MU組合的後續研究。 / Wu, Hoi Yan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2015. / Includes bibliographical references (leaves 90-107). / Abstracts also in Chinese. / Title from PDF title page (viewed on 05, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
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Estudo da toxicidade do adalimumabe (Humira®) intravítreo para a retina de coelhos / Testing intravitreal toxicity of adalimumab (Humira®) in the rabbitManzano, Roberta Pereira de Almeida 16 December 2010 (has links)
O adalimumabe (Humira®, Abbott) é um antagonista do Fator de Necrose Tumoral- alpha (TNF-alfa ). É aprovado para o tratamento de artrite reumatoide, espondilite anquilosante, doença de Crohn, psoríase crônica e artrite reumatoide juvenil. É um anticorpo monoclonal que contém apenas sequências humanas de peptídeos contra a molécula do Fator de Necrose Tumoral-alfa. Na literatura, relatos e série de casos sugerem que os antagonistas do Fator de Necrose Tumoral-alfa são úteis no tratamento da inflamação ocular, edema macular cistoide e secundário à uveíte e degeneração macular relacionada à idade. Entretanto, a administração sistêmica do adalimumabe pode gerar efeitos adversos graves. A fim de diminuir esses efeitos adversos e aumentar a concentração da medicação no segmento posterior do olho, uma possível opção é a injeção intravítrea. O objetivo do presente estudo foi avaliar a toxicidade do adalimumabe intravítreo nas diferentes doses para a retina de coelhos por meio de avaliação clínica (biomicroscopia e oftalmoscopia indireta), funcional (eletrorretinograma) e histopatológica (microscopia óptica e eletrônica). Foram utilizados 30 coelhos albinos da raça Nova Zelândia divididos em cinco grupos de seis coelhos. Injeções intravítreas foram realizadas nas seguintes concentrações de adalimumabe: 0,5mg/0,1ml, 1mg/0,1ml, 2,5mg/0,1ml, 5,0mg/0,1ml e 10mg/0,2ml e 0,1ml de solução salina balanceada (BSS) foi injetada nos olhos esquerdos dos grupos 1 e 2 para constituir o grupo controle. Foram realizadas biomicroscopia e fundoscopia e sinais de inflamação, infecção ou toxicidade foram observados durante duas semanas. O eletrorretinograma foi realizado antes do tratamento e após 14 dias da injeção intravítrea. Os animais foram sacrificados, foi feita a enucleação dos olhos, e o tecido para a avaliação histopatológica foi preparado. A injeção intravítrea de adalimumabe (Humira®) nas doses estudadas até 5mg (0,5mg, 1,0mg, 2,5mg, 5mg) não apresentou sinais clínicos, eletrorretinográficos e histopatológicos de toxicidade para a retina de coelhos a curto prazo. No grupo de 10mg, foram observados sinais inflamatórios leves em três dos seis olhos e houve diminuição da amplitude da onda a na resposta fotópica do ERG, não foram observadas alterações na microscopia óptica / Adalimumab is a fully human anti-TNF alpha monoclonal antibody consisting of 100% human sequences developed using phage display technology. It is currently FDA approved for the treatment of rheumatoid arthritis, ankylosing spondylitis, Crohns disease, moderate to severe chronic psoriasis, and juvenile idiopathic arthritis. Anti-TNF alpha drugs may be an effective therapy for cystoid macular edema associated with uveitis. Significant improvements in chronic diabetic macular edema and regression of CNV from AMD have also been documented in small published series after systemic treatment with TNF-alpha antagonists. However the systemic administration of these drugs can have serious side effects. Intravitreous injection would assure delivery of high concentrations of medication at the posterior segment with minimum side effects.The aim of this study was to evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira®) in the rabbit eye. Thirty New Zealand albino rabbits received intravitreous injections of 0.1ml of adalimumab 0.5 mg (6 eyes), 1mg (6 eyes), 2.5mg (6 eyes), 5mg (6 eyes) and 0.2ml was injected in the10mg (6 eyes) group. BSS (0,1ml) was injected in the left eye of the rabbits from the groups 1 and 2 to serve as control group. Slit lamp biomicroscopy, fundoscopy were carried out at baseline, day 7 and 14 following intravitreous injection while electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14 and histopathological examination of the eyes was performed. The tested doses of intravitreous adalimumab up to 5mg (0.5mg, 1.0mg, 2.5mg, 5mg) had no associated ocular short-term toxicity in rabbit eyes. The 10mg group showed mild inflammatory reaction in 3 out of 6 eyes and showed decrease in the a wave amplitude in the photopic response, light microscopy was normal
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Atividade mutagênica e ativadora da resposta imune celular induzidas por Byrsonima crassa Niedenzu e Byrsonima intermedia A.Juss. (Malpighiaceae)Cardoso, Cássia Regina Primila [UNESP] 21 February 2006 (has links) (PDF)
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cardoso_crp_me_arafcf.pdf: 859101 bytes, checksum: dc8d0d66975b1493a8b7a5a2830d3074 (MD5) / Universidade Estadual Paulista (UNESP) / Considerando a pesquisa de novas moléculas farmacologicamente ativas, orientada pelo uso tradicional das plantas com finalidade terapêutica, o presente trabalho avaliou os efeitos genotóxicos e de ativação do sistema imunológico em duas espécies de plantas do gênero Byrsonima: Byrsonima crassa e Byrsonima intermedia. Essas espécies são plantas de uso popular, pertencentes à flora do Cerrado Brasileiro, utilizadas pela população para disfunções gástricas e diarréias. Foram realizados ensaios para a caracterização da mutagenicidade dos extratos, através do Teste de Ames (TA), utilizando-se linhagens geneticamente modificadas de Salmonella typhimurium e de ativação da resposta imune celular, utilizando-se cultura de macrófagos de exsudato peritoneal (PEC) de camundongos Swiss, avaliando a liberação celular de Fator de Necrose Tumoral-alfa (TNF-α) e Óxido nítrico (NO), importantes moduladores da resposta inflamatória. Foi verificado que somente o extrato metanólico de B.crassa apresentou atividade mutagênica positiva na linhagem TA98, com e sem ativação metabólica. Analisando-se as frações aquosa e acetato de etila, verificou-se que o composto provavelmente responsável pela atividade mutagênica do extrato metanólico está presente na fração acetato. Testes realizados com os compostos isolados dessa fração (catequina, galato de metila, querecetina -3-O-β-Dgalactopiranosídeo, quercetina-3-O-α-arabinopiranosídeo e amentoflavona) revelaram ação mutagênica da amentoflavona e indícios de mutagenicidade da quercetina arabinopiranosídeo. Nos ensaios imunológicos, verificou-se que os extratos de B.crassa e B.intermedia promoveram estímulo da liberação de NO por macrófagos de camundongos em níveis reduzidos, assim como a fração aquosa do extrato metanólico de B.crassa. A fração acetato de etila do extrato... / Considering the research of active new molecules, leaded by the traditional use of plants with therapeutic proposal, this paper tested the genotoxic effects and the activation of the immune system in two species of Byrsonima: Byrsonima crassa and Byrsonima intermedia. These are popular use species that belong to the Brazilian Cerrado, utilized by population to gastric dysfunctions and diarrheas. Many assays were done to give the characterization of mutagenicity of the extracts, through the Ames test (TA) using a line of genetic changed Salmonella typhimurium and the activation of the cellular response, using a culture of peritoneal macrophages from Swiss mice, to test the cell liberation of the Tumor Necrosis Factor-apha (TNF-a) and Nitric Oxide (NO), important modulators on the inflammation response. It was verified that only the methanolic extract of B.crassa presented positive mutagenic activity in the line TA98, with and without metabolic activation. Analyzing the watering and ethyl acetate portions, it was checked that the substance that probably is responsible by the mutagenic activity of the methanolic extract is present on the ethyl acetate portion. Assays achieved with isolated compounds from this portion - (+)-catechin, methyl galate, quercetin-3-O-ß-D-galactopyranoside, quercetin-3-O-a-Larabinopyranoside and amentoflavone - discovered mutagenic activity of amentoflavone and mutagenicity signals of quercetin-3-O-a-L-arabinopyranoside. On this immunologic assays, it was observed that the B.crassa and B.intermedia extracts did not promote the stimulation of leaving NO and TNF-a by macrophages of mouse, just live the watering portion from B.crassa methanolic extract. The ethyl acetate B.crassa portion presented stimulated and relevant activity to the liberation of NO and TNF-a. (Complete abstract, click electronic address below).
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Tumor necrosis factor triggers the expression and activation of matrix metalloproteinases through NADPH-dependent superoxide productionAwad, Ahmed 06 1900 (has links)
Tumor necrosis factor (TNF) is upregulated in a number of cardiomyopathies. This thesis investigates TNF in triggering the expression and activation of matrix metalloproteinases (MMPs) in pressure overload cardiac disease, and explores the role of superoxide.
Cardiac pressure overload was generated in adult wild-type and TNF-/- mice by transverse aortic constriction. Isolated cardiomyocytes and cardiofibroblasts from neonatal mice ventricles were treated with recombinant TNF (rTNF), and MMP induction and activation were assessed, with and without apocynin (a NADPH-oxidase inhibitor).
TNF-/- mice showed less superoxide production and MMP activation, compared to wild-type mice, following pressure overload. rTNF upregulated the production of NADPH-dependent superoxide in cardiomyocytes as early as 1 hour (24 hours in cardiofibroblasts). rTNF also increased the expression of MMP-9 and MMP-12 in cardiomyocytes more than in cardiofibroblasts, and MMP-8 and MMP-13 more in cardiofibroblasts. This induction in both cardiac cell types was concomitant with superoxide production.
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Aspects on inflammation and cardiovascular comorbidity in rheumatoid arthritisLjung, Lotta January 2012 (has links)
There is an increased risk for cardiovascular (CV) comorbidity among patients with rheumatoid arthritis (RA), with premature atherosclerosis, and a higher incidence of CV events, compared with the general population. Disease related factors add to the CV risk, and interact with the traditional CV risk factors. The underlying mechanism for this is not completely understood. In active RA there is a loss of muscle mass and an increase in body fat content. Production of cytokines, i.e., adipokines, in the adipose tissue could link the inflammation with the CV system. Control of the inflammation has been suggested to modify the CV risk in RA, and the recently introduced biological drugs, such as the tumor necrosis factor inhibitors (TNFi), have opened up new treatment opportunities. The aim of this thesis was to evaluate aspects of the interaction between inflammation and CV comorbidity in RA using biochemical and epidemiological methods. Methods In the first two studies, patients with established RA were examined for clinical disease activity, and blood samples were analysed for cytokines and adipokines using ELISAs and multiplex technology. In Study I (n RA=23) anthropometric measurements were assessed and in Study II (n RA=51) measurements of intima-media thickness (IMT), and endothelial function (FMD). From a subgroup of patients (Study II, n RA=13) samples of abdominal subcutaneous adipose tissue (SAT) were analysed for content of adipokines. In study III and IV associations between treatment with TNFi and acute coronary syndromes (ACS) were analysed using data from the Swedish Rheumatology Register; in Study III regarding early RA (n TNFi exposed=1,271, n bionaïve RA=4,729), and in Study IV comprising patients with RA of all stages (n TNFi exposed=7,213, n bionaïve RA=17,769) and with a matched general population comparator cohort (n=32,161). Associations between response to TNFi therapy and risk for ACS in the early RA cohort were evaluated in a nested case-control design (cases n=24, controls n=81). Results Serum levels of the cytokines/adipokines interleukin-1 receptor antagonist (IL-1Ra), IL-6, osteopontin, visfatin and TNF were increased in patients compared with controls (p≤0.001-0.036). The amount of TNF receptor II extracted from SAT was greater in patients (p=0.006). The serum (s-) levels of IL-1Ra correlated with s-leptin (r=0.71, p≤0.001) and s-haptoglobin in RA patients (r=0.56, p≤0.01). The result from a factor analysis indicated IL-1Ra to be associated with both adipose tissue and inflammation. Levels of s-visfatin (p=0.019) and s-IL-1Ra (p=0.023), respectively, were positively associated with IMT independently of inflammatory activity and CV risk factors. PAI-1 and MCP-1 extracted from SAT showed inverse associations with IMT. Patients with RA, whether exposed to TNFi or bio-naïve, had a doubled risk for ACS compared with the general population; HR 2.09 (95%CI 1.58-2.76) and 1.80 (1.49-2.17), respectively. No significant associations between risk for ACS and TNFi exposure were detected after adjustments; HR 0.80 (0.52-1.24) in early RA and HR 1.08 (0.82-1.41) in RA of any duration. Furthermore, no association between the risk for ACS and response to TNFi treatment in patients with early RA was observed, OR 1.5 (0.3-6.9). Conclusions The results indicate that cytokines/adipokines may have a role in the development of atherosclerosis in RA patients. A continuing increase in the risk of ACS in RA compared with the general population, despite modern therapeutic strategies, was noted. Neither exposure nor response to treatment with TNFi was associated with any modification of the risk for ACS.
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Tumor necrosis factor triggers the expression and activation of matrix metalloproteinases through NADPH-dependent superoxide productionAwad, Ahmed Unknown Date
No description available.
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Protective role of olive oil and its major component oleic acid in TNF-α induced remodeling subsequent to myocardial infarction in ratsAl-Shudiefat, Abd Al-Rahman 01 1900 (has links)
Oxidative stress and inflammation are important factors involved in the progression of heart failure. An important cytokine produced during myocardial infarction (MI) is tumor necrosis factor alpha (TNF-α). TNF-α may induce oxidative stress, cell damage, apoptosis and cardiac dysfunction. Considering the anti-inflammatory and anti-oxidant properties of extra-virgin olive oil and its major component (80%) oleic acid (OA), and their benefits to the cardiovascular system, we hypothesized that the negative effects of TNF-α in the pathogenesis of heart failure will be mitigated by olive oil consumption. This hypothesis was tested by examining the effects of a special diet supplemented with 10% olive oil, in coronary artery ligated animal model of MI. Corn oil (10%) supplementation was used as a control for matching caloric intake. Animals in the sham and ligated groups fed regular chow, olive oil, and corn oil were studied at 4 and 16 weeks post myocardial infarction (PMI).
Mortality, diet consumption, weight gain and conduction system abnormalities were comparable among all ligated groups. Echocardiography showed that MI deteriorated cardiac function, and olive oil restored the function. At 16 weeks PMI, only corn oil fed groups showed significant increase in both total cholesterol and HDL. Corn oil was not able to offer protection to the heart, suggesting that the beneficial effects of olive oil are not due to increased caloric intake or increased HDL. MI increased myocardial TNF-α, oxidative stress, lipid peroxidation, pro-apoptotic protein expression (Bax, cleaved Caspase 3, cleaved PARP, TGFβ, Bnip3), cytochrome C release, MAP kinase activation (p38, JNK) and decreased anti-apoptotic protein Bcl-xL expression at both 4 and 16 weeks PMI, and these changes were modulated by olive oil.
In order to further test the central role of TNF-α PMI, we examined the possible miti-gation of TNF-α induced changes by OA in isolated adult rat cardiomyocytes. TNF-α in-creased oxidative stress, cell damage, cell death, and apoptosis, while OA treatment miti-gated these TNF-α induced effects.
We concluded that TNF-α is implicated in the progression of heart failure subsequent to MI and that OA in olive oil may prevent this progression, through its anti-oxidant, anti-inflammatory, anti-hypertensive, and inotropic effects.
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Ectopic expression of TAL-1 increases resistance to TNF[alpha]-induced apoptosis in Jurkat cells via changes in the NF-kB signaling pathway / Ectopic expression of T-cell acute lymphoblastic leukemia 1 increases resistance to tumor necrosis factor [alpha]-induced apoptosis in Jurkat cells via changes in the nuclear factor kappa B signaling pathwayLucas, Bethany R. 09 July 2011 (has links)
TAL-1, ectopically expressed in 60% of T-cell acute lymphoblastic leukemia (T-ALL) patients, may contribute to poor chemotherapy response. This research sought to determine if TAL-1 influences expression of proteins involved in the NF-kB signaling pathway and thus, resistance to cell death. NF-kB, IKKy, and TRAF-2 expression levels were found to be TAL-1 dependent. Cell death levels were higher in staurosporine-treated cells compared to tumor necrosis factor a-treated or dual-treated cells. TAL-1, NF-kB, IKKy, and TRAF-2 expression levels were elevated in tumor necrosis factor a-treated cells and reduced in staurosporine-treated or dual treated cells compared to untreated cells. These results suggest TAL-1 influences expression of proteins involved in the NF-kB signaling pathway, thus inducing an anti-apoptotic response in the cell. / Department of Biology
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Regulation of interleukin-1[Beta] and tumor necrosis factor[alpha] synthesis by fatty acids and eicosanoids / by Gillian Elizabeth Caughey.Caughey, Gillian Elizabeth January 1998 (has links)
Bibliography: leaves 267-345. / xi, 345, [61] leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the regulation of interleukin-1[Beta] and tumor necrosis factor[alpha] synthesis by fatty acids and eicosanoids by examining the mediator synthesis following dietary fatty acid manipulation / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1998?
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Tumour necrosis factor : alpha signal transduction in rat corpus luteum apoptosisAbdo, Michael A. January 2002 (has links)
[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] Apoptosis is a morphologically distinct form of cell death that is involved in the regulation of normal and aberrant cell systems. The complexities of the apoptotic cell death pathway arise from variation in both the cellular specialisation and initial stimulus. The corpus luteum (CL) is an endocrine gland that whilst critical to the maintenance of pregnancy in the rat, regresses at the completion of each oestrous cycle and pregnancy. This regression is facilitated through apoptosis; though, the stimulus and factors involved in the apoptotic pathway are poorly understood. Previous studies suggest that CL regression is not initiated through failure of luteotrophic support, but rather the active production of a luteolytic factor, of which tumour necrosis factor -alpha (TNFα) is one possible candidate. Several publications have reported the participation of the immune system in ovarian events. There is evidence that TNFα expression within the ovary is coordinated between cells of the immune system and the hormonal regulation of the CL. This study has focussed on the role of TNFα in CL apoptosis and the factors involved in this apoptotic pathway. TNFα-induced cell death is governed by the presence of the two TNFα receptors (TNFR) and several second messenger systems that include; the sphingolipids, mitogen-activated protein (MAP) kinases, nitric oxide (NO), nuclear factor-kappaB (NF-κB) and the caspases. These factors and their interactions were assessed in the rat CL during pregnancy and post-partum, and in vitro. Apoptosis was measured through the analysis of DNA fragmentation using DNA 3’ end labelling and single cell electrophoresis (COMET assay). Assessment of mRNA and protein expression was through Real-time RT-PCR and Western blot analysis; proteins were localised within the CL by immunocytochemistry. In addition, specific measurement of sphingolipid expression and nitric oxide (NO) production was by high performance liquid chromatography (HPLC) and NO assay respectively. Following parturition, TNFα mRNA and protein expression increased corresponding to the onset of CL apoptosis and increased expression of the chemotactic factor monocyte chemoattractant protein -1 (MCP-1). Furthermore, CL apoptosis was induced by treatment with recombinant TNFα in a time- and dose-dependent manner. A similar effect was observed in isolated luteal cells. Simultaneously, the functional regression of the CL was assessed by measurement of both progesterone synthesis and steroidogenic acute regulatory (StAR) protein expression. StAR mRNA and protein expression declined toward parturition in vivo. Immunocytochemical studies revealed the presence of TNFα receptors 1 (TNFR1) and 2 (TNFR2) in luteal cells. Furthermore, TNFR mRNA was isolated from CL throughout pregnancy and post-partum. Subsequently, the role of the sphingolipids ceramide and sphingosine was examined during CL apoptosis in vitro. Ceramide and sphingosine were found to be potent apoptotic agents when administered in vitro (50µM). The downstream signal transduction of TNFα and ceramide was assessed through MAP kinase expression. Both TNFα and ceramide increased expression of the pro-apoptotic p38 MAP kinase with no change to the non-apoptotic extracellular signal-related kinase (ERK1&2). Despite previous reports of c-Jun NH2 terminal kinase (JNK) involvement in the cell death pathway, JNK expression was not evident in the rat CL. The caspases are a family of cysteine proteases central to the regulation and execution of apoptosis. General inhibition of the caspase cascade in vitro was effective in preventing apoptosis regardless of the apoptotic stimulus (TNFα, ceramide and sphingosine), suggesting that this pathway is central to CL apoptosis. Specific inhibition of several caspases produced a varying effect; inhibition of caspases 3, 6 and 8 significantly reduced the level of TNFα-induced apoptosis, thus supporting their classification as either regulatory or effector caspases. NO is endowed with the unique ability to initiate and to block apoptosis and this dichotomy extends to the cytotoxic actions of TNFα. Inhibition of NO production by treating CL with L-NAME prevented the onset of apoptosis, whilst NO production increased in response to increasing levels of apoptosis following trophic withdrawal. However, this effect was not seen during TNFα-induced apoptosis, suggesting that the actions of NO are independent of TNFα. The data presented within this study examine multiple elements of the TNFα cell death pathway in a single system. The results suggest that these elements are involved in TNFα signal transduction and furthermore, in rat CL apoptosis. It can be said that TNFα plays an active role in CL regression through the activation of the caspases, the sphingolipids and the MAP kinases.
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