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Non-steroidal anti-inflammatory drugs (NSAIDs) are most extensively used over-the-counter FDA-approved analgesic medicines for treating inflammation, musculoskeletal pain, arthritis, pyrexia and menstrual cramps. Moreover, aspirin is widely used against cardiovascular complications. Owing to their non-addictive nature, NSAIDs are also commissioned as safer opioid-sparing alternatives in acute trauma and post-surgical treatments. In fact, therapeutic spectrum of NSAIDs is expanding. These "wonder-drugs" are now repurposed against lung diseases, diabetes, neurodegenerative disorders, fungal infections and most notably cancer, due to their efficacy against chemoresistance, radio-resistance and cancer stem cells. However, prolonged NSAID treatment accompany several adverse effects. Mechanistically, apart from cyclooxygenase inhibition, NSAIDs directly target mitochondria to induce cell death. Interestingly, there are also incidences of dose-dependent effects where NSAIDs are found to improve mitochondrial health thereby suggesting plausible mitohormesis. While mitochondria-targeted effects of NSAIDs are discretely studied, a comprehensive account emphasizing the multiple dimensions in which NSAIDs affect mitochondrial structure-function integrity, leading to cell death, is lacking. This review discusses the current understanding of NSAID-mitochondria interactions in the pathophysiological background. This is essential for assessing the risk-benefit trade-offs of NSAIDs for judiciously strategizing NSAID-based approaches to manage pain and inflammation as well as formulating effective anti-cancer strategies. We also discuss recent developments constituting selective mitochondria-targeted NSAIDs including theranostics, mitocans, chimeric small molecules, prodrugs and nanomedicines that rationally optimize safer application of NSAIDs. Thus, we present a comprehensive understanding of therapeutic merits and demerits of NSAIDs with mitochondria at its cross roads. This would help in NSAID-based disease management research and drug development.
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Gastric cancer (GC) is a deadly malignancy that demands effective therapeutic intervention capitalizing unique drug target/s. Here, we report that indomethacin, a cyclooxygenase non-selective non-steroidal anti-inflammatory drug, arrests GC cell growth by targeting mitochondrial deacetylase Sirtuin 3 (SIRT3). Interaction study revealed that indomethacin competitively inhibited SIRT3 by binding to nicotinamide adenine dinucleotide (NAD)-binding site. The Cancer Genome Atlas data meta-analysis indicated poor prognosis associated with high SIRT3 expression in GC. Further, transcriptome sequencing data of human gastric adenocarcinoma cells revealed that indomethacin treatment severely downregulated SIRT3. Indomethacin-induced SIRT3 downregulation augmented SOD2 and OGG1 acetylation, leading to mitochondrial redox dyshomeostasis, mtDNA damage, respiratory chain failure, bioenergetic crisis, mitochondrial fragmentation, and apoptosis via blocking the AMPK/PGC1α/SIRT3 axis. Indomethacin also downregulated SIRT3 regulators ERRα and PGC1α. Further, SIRT3 knockdown aggravated indomethacin-induced mitochondrial dysfunction as well as blocked cell-cycle progression to increase cell death. Thus, we reveal how indomethacin induces GC cell death by disrupting SIRT3 signaling.
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BACKGROUND AND PURPOSE: Mitochondrial oxidative stress, inflammation and apoptosis primarily underlie gastric mucosal injury caused by the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Alternative gastroprotective strategies are therefore needed. Sirtuin-3 pivotally maintains mitochondrial structural integrity and metabolism while preventing oxidative stress; however, its relevance to gastric injury was never explored. Here, we have investigated whether and how sirtuin-3 stimulation by the phytochemical, honokiol, could rescue NSAID-induced gastric injury. EXPERIMENTAL APPROACH: Gastric injury in rats induced by indomethacin was used to assess the effects of honokiol. Next-generation sequencing-based transcriptomics followed by functional validation identified the gastroprotective function of sirtuin-3. Flow cytometry, immunoblotting, qRT-PCR and immunohistochemistry were used measure effects on oxidative stress, mitochondrial dynamics, electron transport chain function, and markers of inflammation and apoptosis. Sirtuin-3 deacetylase activity was also estimated and gastric luminal pH was measured. KEY RESULTS: Indomethacin down-regulated sirtuin-3 to induce oxidative stress, mitochondrial hyperacetylation, 8-oxoguanine DNA glycosylase 1 depletion, mitochondrial DNA damage, respiratory chain defect and mitochondrial fragmentation leading to severe mucosal injury. Indomethacin dose-dependently inhibited sirtuin-3 deacetylase activity. Honokiol prevented mitochondrial oxidative damage and inflammatory tissue injury by attenuating indomethacin-induced depletion of both sirtuin-3 and its transcriptional regulators PGC1α and ERRα. Honokiol also accelerated gastric wound healing but did not alter gastric acid secretion, unlike lansoprazole. CONCLUSIONS AND IMPLICATIONS: Sirtuin-3 stimulation by honokiol prevented and reversed NSAID-induced gastric injury through maintaining mitochondrial integrity. Honokiol did not affect gastric acid secretion. Sirtuin-3 stimulation by honokiol may be utilized as a mitochondria-based, acid-independent novel gastroprotective strategy against NSAIDs.
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Sirtuína 3 , Ratos , Animais , Sirtuína 3/metabolismo , Ratos Sprague-Dawley , Anti-Inflamatórios não Esteroides/farmacologia , Indometacina/toxicidade , Mucosa Gástrica/metabolismo , Apoptose , Inflamação/metabolismoRESUMO
Gastroduodenal inflammation and ulcerative injuries are increasing due to expanding socio-economic stress, unhealthy food habits-lifestyle, smoking, alcoholism and usage of medicines like non-steroidal anti-inflammatory drugs. In fact, gastrointestinal (GI) complications, associated with the prevailing COVID-19 pandemic, further, poses a challenge to global healthcare towards safeguarding the GI tract. Emerging evidences have discretely identified mitochondrial dysfunctions as common etiological denominators in diseases. However, it is worth realizing that mitochondrial dysfunctions are not just consequences of diseases. Rather, damaged mitochondria severely aggravate the pathogenesis thereby qualifying as perpetrable factors worth of prophylactic and therapeutic targeting. Oxidative and nitrosative stress due to endogenous and exogenous stimuli triggers mitochondrial injury causing production of mitochondrial damage associated molecular patterns (mtDAMPs), which, in a feed-forward loop, inflicts inflammatory tissue damage. Mitochondrial structural dynamics and mitophagy are crucial quality control parameters determining the extent of mitopathology and disease outcomes. Interestingly, apart from endogenous factors, mitochondria also crosstalk and in turn get detrimentally affected by gut pathobionts colonized during luminal dysbiosis. Although mitopathology is documented in various pre-clinical/clinical studies, a comprehensive account appreciating the mitochondrial basis of GI mucosal pathogenesis is largely lacking. Here we critically discuss the molecular events impinging on mitochondria along with the interplay of mitochondria-derived factors in fueling mucosal damage. We specifically emphasize on the potential role of aberrant mitochondrial dynamics, anomalous mitophagy, mitochondrial lipoxidation and ferroptosis as emerging regulators of GI mucosal pathogenesis. We finally discuss about the prospect of mitochondrial targeting for next-generation drug discovery against GI disorders.
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COVID-19 , Mitofagia , Alarminas , Humanos , Mitocôndrias/patologia , Dinâmica Mitocondrial , PandemiasRESUMO
Fibrotic lung diseases qualify among the most dreaded irreversible interstitial pulmonary complications with progressive yet largely unpredictable clinical course. Idiopathic pulmonary fibrosis (IPF) is the most challenging prototype characterized by unknown and complex molecular etiology, severe dearth of non-invasive therapeutic options and average lifespan of 2-5 years in patients post diagnosis. Lung fibrosis (LF) is a leading cause of death in the industrialized world with the propensity to contract, significantly increasing with age. Approximately 45% deaths in US are attributed to fibrotic diseases while around 7% respiratory disease-associated deaths, annually in UK, are actually attributed to IPF. Recent developments in the field of LF have unambiguously pointed towards the pivotal role of Sirtuins (SIRTs) in regulating disease progression, thereby qualifying as potential anti-fibrotic drug targets. These NAD+-dependent lysine deacetylases, deacylases and ADP-ribosyltransferases are evolutionarily conserved proteins, regulated by diverse metabolic/environmental factors and implicated in age-related degenerative and inflammatory disorders. While SIRT1, SIRT6 and SIRT7 are predominantly nuclear, SIRT3, SIRT4, SIRT5 are mainly mitochondrial and SIRT2 is majorly cytosolic with occasional nuclear translocation. SIRT1, SIRT3, SIRT6 and SIRT7 are documented as cytoprotective sirtuins implicated in cardiovascular, pulmonary and metabolic diseases including fibrosis; however functional roles of remaining sirtuins in pulmonary pathologies are yet elusive. Here, we provide a comprehensive recent update on the regulatory role of sirtuins on LF along with discussion on potential therapeutic modulation of endogenous Sirtuin expression through synthetic/plant-derived compounds which can help synthetic chemists and ethnopharmacologists to design new-generation cheap, non-toxic Sirtuin-based drugs against LF.
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Pulmão/metabolismo , Pulmão/patologia , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Sirtuínas/metabolismo , Animais , Humanos , Mitocôndrias/metabolismo , Terapia de Alvo Molecular , Transdução de SinaisRESUMO
Owing to the efficacy in reducing pain and inflammation, non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most popularly used medicines confirming their position in the WHO's Model List of Essential Medicines. With escalating musculoskeletal complications, as evident from 2016 Global Burden of Disease data, NSAID usage is evidently unavoidable. Apart from analgesic, anti-inflammatory and antipyretic efficacies, NSAIDs are further documented to offer protection against diverse critical disorders including cancer and heart attacks. However, data from multiple placebo-controlled trials and meta-analyses studies alarmingly signify the adverse effects of NSAIDs in gastrointestinal, cardiovascular, hepatic, renal, cerebral and pulmonary complications. Although extensive research has elucidated the mechanisms underlying the clinical hazards of NSAIDs, no review has extensively collated the outcomes on various multiorgan toxicities of these drugs together. In this regard, the present review provides a comprehensive insight of the existing knowledge and recent developments on NSAID-induced organ damage. It precisely encompasses the current understanding of structure, classification and mode of action of NSAIDs while reiterating on the emerging instances of NSAID drug repurposing along with pharmacophore modification aimed at safer usage of NSAIDs where toxic effects are tamed without compromising the clinical benefits. The review does not intend to vilify these 'wonder drugs'; rather provides a careful understanding of their side-effects which would be beneficial in evaluating the risk-benefit threshold while rationally using NSAIDs at safer dose and duration.
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Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Inflamatórios não Esteroides/farmacologia , Insuficiência de Múltiplos Órgãos/induzido quimicamente , Animais , Anti-Inflamatórios não Esteroides/classificação , Inibidores de Ciclo-Oxigenase 2/efeitos adversos , Inibidores de Ciclo-Oxigenase 2/classificação , Inibidores de Ciclo-Oxigenase 2/farmacologia , Humanos , Insuficiência de Múltiplos Órgãos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
The subcellular mechanism by which nonsteroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in gastric cancer and normal mucosal cells is elusive because of the diverse cyclooxygenase-independent effects of these drugs. Using human gastric carcinoma cells (AGSs) and a rat gastric injury model, here we report that the NSAID indomethacin activates the protein kinase Cζ (PKCζ)-p38 MAPK (p38)-dynamin-related protein 1 (DRP1) pathway and thereby disrupts the physiological balance of mitochondrial dynamics by promoting mitochondrial hyper-fission and dysfunction leading to apoptosis. Notably, DRP1 knockdown or SB203580-induced p38 inhibition reduced indomethacin-induced damage to AGSs. Indomethacin impaired mitochondrial dynamics by promoting fissogenic activation and mitochondrial recruitment of DRP1 and down-regulating fusogenic optic atrophy 1 (OPA1) and mitofusins in rat gastric mucosa. Consistent with OPA1 maintaining cristae architecture, its down-regulation resulted in EM-detectable cristae deformity. Deregulated mitochondrial dynamics resulting in defective mitochondria were evident from enhanced Parkin expression and mitochondrial proteome ubiquitination. Indomethacin ultimately induced mitochondrial metabolic and bioenergetic crises in the rat stomach, indicated by compromised fatty acid oxidation, reduced complex I- associated electron transport chain activity, and ATP depletion. Interestingly, Mdivi-1, a fission-preventing mito-protective drug, reversed indomethacin-induced DRP1 phosphorylation on Ser-616, mitochondrial proteome ubiquitination, and mitochondrial metabolic crisis. Mdivi-1 also prevented indomethacin-induced mitochondrial macromolecular damage, caspase activation, mucosal inflammation, and gastric mucosal injury. Our results identify mitochondrial hyper-fission as a critical and common subcellular event triggered by indomethacin that promotes apoptosis in both gastric cancer and normal mucosal cells, thereby contributing to mucosal injury.
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Apoptose/efeitos dos fármacos , GTP Fosfo-Hidrolases/metabolismo , Mucosa Gástrica/enzimologia , Indometacina/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/enzimologia , Dinâmica Mitocondrial/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Proteínas de Neoplasias/metabolismo , Proteína Quinase C/metabolismo , Neoplasias Gástricas/enzimologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Apoptose/genética , Linhagem Celular Tumoral , Dinaminas , GTP Fosfo-Hidrolases/genética , Mucosa Gástrica/patologia , Humanos , Sistema de Sinalização das MAP Quinases/genética , Proteínas Associadas aos Microtúbulos/genética , Mitocôndrias/genética , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/genética , Proteínas de Neoplasias/genética , Proteína Quinase C/genética , Ratos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
Myofibroblast differentiation is a key process in the pathogenesis of fibrotic diseases. Transforming growth factor-ß1 (TGF-ß1) is a powerful inducer of myofibroblast differentiation and is implicated in pathogenesis of tissue fibrosis. This study was undertaken to determine the role of mitochondrial deacetylase SIRT3 in TGF-ß1-induced myofibroblast differentiation in vitro and lung fibrosis in vivo. Treatment of human lung fibroblasts with TGF-ß1 resulted in increased expression of fibrosis markers, smooth muscle α-actin (α-SMA), collagen-1, and fibronectin. TGF-ß1 treatment also caused depletion of endogenous SIRT3, which paralleled with increased production of reactive oxygen species (ROS), DNA damage, and subsequent reduction in levels of 8-oxoguanine DNA glycosylase (OGG1), an enzyme that hydrolyzes oxidized guanine (8-oxo-dG) and thus protects DNA from oxidative damage. Overexpression of SIRT3 by adenovirus-mediated transduction reversed the effects of TGF-ß1 on ROS production and mitochondrial DNA damage and inhibited TGF-ß1-induced myofibroblast differentiation. To determine the antifibrotic role of SIRT3 in vivo, we used the bleomycin-induced mouse model of pulmonary fibrosis. Compared with wild-type controls, Sirt3-knockout mice showed exacerbated fibrosis after intratracheal instillation of bleomycin. Increased lung fibrosis was associated with decreased levels of OGG1 and concomitant accumulation of 8-oxo-dG and increased mitochondrial DNA damage. In contrast, the transgenic mice with whole body Sirt3 overexpression were protected from bleomycin-induced mtDNA damage and development of lung fibrosis. These data demonstrate a critical role of SIRT3 in the control of myofibroblast differentiation and lung fibrosis.
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Diferenciação Celular , Dano ao DNA , DNA Mitocondrial/metabolismo , Miofibroblastos/patologia , Fibrose Pulmonar/patologia , Sirtuína 3/metabolismo , 8-Hidroxi-2'-Desoxiguanosina , Animais , Biomarcadores/metabolismo , Bleomicina , Células Cultivadas , Colágeno Tipo I/metabolismo , Citoproteção/efeitos dos fármacos , DNA/metabolismo , DNA Glicosilases/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Humanos , Camundongos Knockout , Modelos Biológicos , Miofibroblastos/metabolismo , Fibrose Pulmonar/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
Cardiovascular diseases (CVDs) are expanding at an alarming rate and people's propensity to develop them increases with age. Growing evidence indicates that sirtuins play a pivotal role in regulating a multitude of age-related diseases. Sirtuins are versatile molecules conserved from archaea to mammals. They are regulated by various metabolic and environmental stimuli. Seven sirtuin homologs (SIRT1-7) are present in mammals, with diverse cellular locations. Recent studies have delineated roles of sirtuins in regulating cardiac pathophysiological conditions under various stressors. SIRT1 is the most extensively studied sirtuin, while the role of other sirtuins in maintaining cardiac growth and function is still emerging. In this review we discuss the present understanding of the role of sirtuins in regulating pathophysiological conditions of the heart.
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Coração/fisiopatologia , Sirtuínas/metabolismo , Animais , Doenças Cardiovasculares/metabolismo , Coração/crescimento & desenvolvimento , Humanos , Sirtuína 1/metabolismoRESUMO
Doxorubicin (Doxo) is a chemotherapeutic drug widely used to treat variety of cancers. One of the most serious side effects of Doxo is its dose-dependent and delayed toxicity to the heart. Doxo is known to induce cardiac mitochondrial damage. Recently, the mitochondrial sirtuin SIRT3 has been shown to protect mitochondria from oxidative stress. Here we show that overexpression of SIRT3 protects the heart from toxicity of Doxo by preventing the drug-induced mitochondrial DNA (mtDNA) damage. Doxo treatment caused depletion of Sirt3 levels both in primary cultures of cardiomyocytes and in mouse hearts, which led to massive acetylation of mitochondrial proteins. Doxo-induced toxicity to cardiomyocytes was associated with increased reactive oxygen species (ROS) production, mitochondrial fragmentation, and cell death. Overexpression of SIRT3 helped to attenuate Doxo-induced ROS levels and cardiomyocyte death. Sirt3 knockout (Sirt3.KO) mice could not endure the full dose of Doxo treatment, developed exacerbated cardiac hypertrophy, and died during the course of treatment, whereas Sirt3 transgenic (Sirt3.tg) mice were protected against Doxo-induced cardiotoxicity. Along with Sirt3, we also observed a concomitant decrease in levels of oxoguanine-DNA glycosylase-1 (OGG1), a major DNA glycosylase that hydrolyzes oxidized-guanine (8-oxo-dG) to guanine. Depletion of OGG1 levels was associated with increased mtDNA damage. Sirt3.KO mice and Doxo-treated mice showed increased 8-oxo-dG adducts in DNA and corresponding increase in mtDNA damage, whereas, 8-oxo-dG adducts and mtDNA damage were markedly reduced in Sirt3 overexpressing transgenic mice hearts. These results thus demonstrated that Sirt3 activation protects the heart from Doxo-induced cardiotoxicity by maintaining OGG1 levels and protecting mitochondria from DNA damage.
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Cardiomiopatias/prevenção & controle , Dano ao DNA , DNA Mitocondrial/metabolismo , Doxorrubicina , Mitocôndrias Cardíacas/enzimologia , Miócitos Cardíacos/enzimologia , Sirtuína 3/metabolismo , 8-Hidroxi-2'-Desoxiguanosina , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/enzimologia , Cardiomegalia/genética , Cardiomegalia/patologia , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/enzimologia , Cardiomiopatias/genética , Cardiomiopatias/patologia , Morte Celular , Células Cultivadas , Adutos de DNA/metabolismo , DNA Glicosilases/metabolismo , DNA Mitocondrial/genética , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Modelos Animais de Doenças , Feminino , Fibroblastos/enzimologia , Fibroblastos/patologia , Hidrólise , Masculino , Camundongos Knockout , Mitocôndrias Cardíacas/patologia , Miócitos Cardíacos/patologia , Estresse Oxidativo , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/deficiência , Sirtuína 3/genética , Sirtuínas/metabolismo , Fatores de TempoRESUMO
Tissue fibrosis is a major cause of organ dysfunction during chronic diseases and aging. A critical step in this process is transforming growth factor ß1 (TGF-ß1)-mediated transformation of fibroblasts into myofibroblasts, cells capable of synthesizing extracellular matrix. Here, we show that SIRT3 controls transformation of fibroblasts into myofibroblasts via suppressing the profibrotic TGF-ß1 signaling. We found that Sirt3 knockout (KO) mice with age develop tissue fibrosis of multiple organs, including heart, liver, kidney, and lungs but not whole-body SIRT3-overexpressing mice. SIRT3 deficiency caused induction of TGF-ß1 expression and hyperacetylation of glycogen synthase kinase 3ß (GSK3ß) at residue K15, which negatively regulated GSK3ß activity to phosphorylate the substrates Smad3 and ß-catenin. Reduced phosphorylation led to stabilization and activation of these transcription factors regulating expression of the profibrotic genes. SIRT3 deacetylated and activated GSK3ß and thereby blocked TGF-ß1 signaling and tissue fibrosis. These data reveal a new role of SIRT3 to negatively regulate aging-associated tissue fibrosis and discloses a novel phosphorylation-independent mechanism controlling the catalytic activity of GSK3ß.
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Envelhecimento , Fibroblastos/patologia , Quinase 3 da Glicogênio Sintase/metabolismo , Miofibroblastos/patologia , Sirtuína 3/metabolismo , Acetilação , Adulto , Animais , Células Cultivadas , Ativação Enzimática , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibrose , Glicogênio Sintase Quinase 3 beta , Humanos , Rim/citologia , Rim/metabolismo , Rim/patologia , Fígado/citologia , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Miocárdio/citologia , Miocárdio/metabolismo , Miocárdio/patologia , Miofibroblastos/citologia , Miofibroblastos/metabolismo , Fosforilação , Transdução de Sinais , Sirtuína 3/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , beta Catenina/metabolismoRESUMO
Components of the conserved engulfment pathways promote programmed cell death in Caenorhabditis elegans (C. elegans) through an unknown mechanism. Here we report that the phagocytic receptor CED-1 mEGF10 is required for the formation of a dorsal-ventral gradient of CED-3 caspase activity within the mother of a cell programmed to die and an increase in the level of CED-3 protein within its dying daughter. Furthermore, CED-1 becomes enriched on plasma membrane regions of neighbouring cells that appose the dorsal side of the mother, which later forms the dying daughter. Therefore, we propose that components of the engulfment pathways promote programmed cell death by enhancing the polar localization of apoptotic factors in mothers of cells programmed to die and the unequal segregation of apoptotic potential into dying and surviving daughters. Our findings reveal a novel function of the engulfment pathways and provide a better understanding of how apoptosis is initiated during C. elegans development.
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Apoptose/fisiologia , Caenorhabditis elegans/fisiologia , Animais , Animais Geneticamente Modificados , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Regulação da Expressão Gênica/fisiologia , Neurônios/citologia , Neurônios/fisiologiaRESUMO
The liver efficiently restores function after damage induced during malarial infection once the parasites are cleared from the blood. However, the molecular events leading to the restoration of liver function after malaria are still obscure. To study this, we developed a suitable model wherein mice infected with Plasmodium yoelii (45% parasitemia) were treated with the antimalarial α/ß-arteether to clear parasites from the blood and, subsequently, restoration of liver function was monitored. Liver function tests clearly indicated that complete recovery of liver function occurred after 25 days of parasite clearance. Analyses of proinflammatory gene expression and neutrophil infiltration further indicated that hepatic inflammation, which was induced immediately after parasite clearance from the blood, was gradually reduced. Moreover, the inflammation in the liver after parasite clearance was found to be correlated positively with oxidative stress and hepatocyte apoptosis. We investigated the role of heme oxygenase 1 (HO-1) in the restoration of liver function after malaria because HO-1 normally renders protection against inflammation, oxidative stress, and apoptosis under various pathological conditions. The expression and activity of HO-1 were found to be increased significantly after parasite clearance. We even found that chemical silencing of HO-1 by use of zinc protoporphyrin enhanced inflammation, oxidative stress, hepatocyte apoptosis, and liver injury. In contrast, stimulation of HO-1 by cobalt protoporphyrin alleviated liver inflammation and reduced oxidative stress, hepatocyte apoptosis, and associated tissue injury. Therefore, we propose that selective induction of HO-1 in the liver would be beneficial for the restoration of liver function after parasite clearance.
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Antimaláricos/uso terapêutico , Heme Oxigenase-1/metabolismo , Fígado/patologia , Malária/tratamento farmacológico , Malária/patologia , Plasmodium yoelii/crescimento & desenvolvimento , Animais , Testes de Função Hepática , Malária/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Nonsteroidal anti-inflammatory drug (NSAID)-induced mitochondrial oxidative stress (MOS) is an important prostaglandin (PG)-independent pathway of the induction of gastric mucosal injury. However, the molecular mechanism behind MOS-mediated gastric pathology is still obscure. In various pathological conditions of tissue injury oxidative stress is often linked with inflammation. Here we report that MOS induced by indomethacin (an NSAID) induces gastric mucosal inflammation leading to proinflammatory damage. Indomethacin, time dependently stimulated the expression of proinflammatory molecules such as intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), interleukin1ß (IL-1ß), and monocyte chemotactic protein-1 (MCP-1) in gastric mucosa in parallel with the increase of neutrophil infiltration and injury of gastric mucosa in rat. Western immunoblotting and confocal microscopic studies revealed that indomethacin induced nuclear translocation of nuclear factor kappa-B (NF-κB) in gastric mucosal cells, which resulted in proinflammatory signaling. The prevention of MOS by antioxidant tryptamine-gallic acid hybrid (SEGA) inhibited indomethacin-induced expression of ICAM-1, VCAM-1, IL-1ß, and MCP-1. SEGA also prevented indomethacin-induced NF-κB activation and neutrophil infiltration as documented by chromatin immunoprecipitation studies and neutrophil migration assay, respectively. Heme oxygenase-1 (HO-1), a cytoprotective enzyme associated with tissue repair mechanisms is stimulated in response to oxidative stress. We have investigated the role of HO-1 against MOS and MOS-mediated inflammation in recovering from gastropathy. Indomethacin stimulated the expression of HO-1 and indomethacin-stimulated HO-1 expression was reduced by SEGA, an antioxidant, which could prevent MOS. Thus, the data suggested that the induction of HO-1 was a protective response against MOS developed by indomethacin. Moreover, the induction of HO-1 by cobalt protoporphyrin inhibited inflammation and chemical silencing of HO-1 by zinc protoporphyrin aggravated the inflammation by indomethacin. Thus, NSAID by promoting MOS-induced proinflammatory response damaged gastric mucosa and HO-1 protected NSAID-induced gastric mucosal damage by preventing NF-κB activation and proinflammatory activity.
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Anti-Inflamatórios não Esteroides/toxicidade , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Heme Oxigenase-1/metabolismo , NF-kappa B/metabolismo , Animais , Western Blotting , Imunoprecipitação da Cromatina , Mucosa Gástrica/lesões , Indometacina/efeitos adversos , Inflamação/induzido quimicamente , Microscopia Confocal , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Infiltração de Neutrófilos/efeitos dos fármacos , Estresse Oxidativo , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-DawleyRESUMO
We have investigated the impact of persistent intravascular hemolysis on liver dysfunction using the mouse malaria model. Intravascular hemolysis showed a positive correlation with liver damage along with the increased accumulation of free heme and reactive oxidants in liver. Hepatocytes overinduced heme oxygenase-1 (HO-1) to catabolize free heme in building up defense against this pro-oxidant milieu. However, in a condition of persistent free heme overload in malaria, the overactivity of HO-1 resulted in continuous transient generation of free iron to favor production of reactive oxidants as evident from 2',7'-dichlorofluorescein fluorescence studies. Electrophoretic mobility shift assay documented the activation of NF-κB, which in turn up-regulated intercellular adhesion molecule 1 as evident from chromatin immunoprecipitation studies. NF-κB activation also induced vascular cell adhesion molecule 1, keratinocyte chemoattractant, and macrophage inflammatory protein 2, which favored neutrophil extravasation and adhesion in liver. The infiltration of neutrophils correlated positively with the severity of hemolysis, and neutrophil depletion significantly prevented liver damage. The data further documented the elevation of serum TNFα in infected mice, and the treatment of anti-TNFα antibodies also significantly prevented neutrophil infiltration and liver injury. Deferoxamine, which chelates iron, interacts with free heme and bears antioxidant properties that prevented oxidative stress, NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Furthermore, the administration of N-acetylcysteine also prevented NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Thus, hepatic free heme accumulation, TNFα release, oxidative stress, and NF-κB activation established a link to favor neutrophil infiltration in inducing liver damage during hemolytic conditions in malaria.