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1.
Adv Exp Med Biol ; 1193: 175-194, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31368104

RESUMO

Sepsis, defined as life-threatening tissue damage and organ dysfunction caused by a dysregulated host response to infection, is a critical disease which imposes global health burden. Sepsis-induced organ dysfunction, including circulatory and cardiac dysfunction, hepatic dysfunction, renal dysfunction, etc., contributes to high mortality and long-term disability of sepsis patients. Altered inflammatory response, ROS and reactive aldehyde stress, mitochondrial dysfunction, and programmed cell death pathways (necrosis, apoptosis, and autophagy) have been demonstrated to play crucial roles in septic organ dysfunction. Unfortunately, except for infection control and supportive therapies, no specific therapy exists for sepsis. New specific therapeutic targets are highly warranted. Emerging studies suggested a role of potential therapeutic target of ALDH2, a tetrameric enzyme located in mitochondria to detoxify aldehydes, in septic organ dysfunction. In this article, we will review the presentations and pathophysiology of septic organ dysfunction, as well as summarize and discuss the recent insights regarding ALDH2 in sepsis.


Assuntos
Aldeído-Desidrogenase Mitocondrial/genética , Sepse/genética , Apoptose , Autofagia , Humanos , Mitocôndrias/enzimologia
2.
Plant Mol Biol ; 101(1-2): 183-202, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31286324

RESUMO

KEY MESSAGE: Isoforms of 2-OGDH E1 subunit are not functionally redundant in plant growth and development of A. thaliana. The tricarboxylic acid cycle enzyme 2-oxoglutarate dehydrogenase (2-OGDH) converts 2-oxoglutarate (2-OG) to succinyl-CoA concomitant with the reduction of NAD+. 2-OGDH has an essential role in plant metabolism, being both a limiting step during mitochondrial respiration as well as a key player in carbon-nitrogen interactions. In Arabidopsis thaliana two genes encode for E1 subunit of 2-OGDH but the physiological roles of each isoform remain unknown. Thus, in the present study we isolated Arabidopsis T-DNA insertion knockout mutant lines for each of the genes encoding the E1 subunit of 2-OGDH enzyme. All mutant plants exhibited substantial reduction in both respiration and CO2 assimilation rates. Furthermore, mutant lines exhibited reduced levels of chlorophylls and nitrate, increased levels of sucrose, malate and fumarate and minor changes in total protein and starch levels in leaves. Despite the similar metabolic phenotypes for the two E1 isoforms the reduction in the expression of each gene culminated in different responses in terms of plant growth and seed production indicating distinct roles for each isoform. Collectively, our results demonstrated the importance of the E1 subunit of 2-OGDH in both autotrophic and heterotrophic tissues and suggest that the two E1 isoforms are not functionally redundant in terms of plant growth in A. thaliana.


Assuntos
Arabidopsis/enzimologia , Carbono/metabolismo , Complexo Cetoglutarato Desidrogenase/metabolismo , Nitrogênio/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Complexo Cetoglutarato Desidrogenase/genética , Mitocôndrias/enzimologia , Mutagênese Insercional , Nitratos/metabolismo , Fenótipo , Filogenia , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Isoformas de Proteínas , Subunidades Proteicas , Plântula/enzimologia , Plântula/genética , Plântula/crescimento & desenvolvimento , Sementes/enzimologia , Sementes/genética , Sementes/crescimento & desenvolvimento
4.
Gen Physiol Biophys ; 38(4): 335-342, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31219428

RESUMO

Ultraviolet-inactivated Sendai virus strain Tianjin (UV-Tianjin) has been proved to have antitumor effects in many kinds of tumor cells. Here, we investigated the anticancer properties of UV-Tianjin on human osteosarcoma HOS cells and the underlying molecular mechanism. Apoptosis, intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential were determined by flow cytometry analysis. The expression levels of apoptosis-related proteins were tested by western blotting. The results showed that UV-Tianjin concentration-dependently induced apoptosis in HOS cells. UV-Tianjin-induced apoptosis was mediated by the mitochondrial pathway, which was confirmed by mitochondrial dysfunction, downregulation of B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-xL (Bcl-xL) and myeloid cell leukemia-1 (Mcl-1), upregulation of B-cell lymphoma 2 associated X protein (Bax) and Bcl-2 Homologous Antagonist/Killer (Bak), as well as the cleavage of caspase-9 and -3. Further analysis showed that UV-Tianjin augmented the phosphorylation of c-Jun N-terminal kinase, the extracellular-regulated kinase and p38, the major components of mitogen-activated protein kinase (MAPK) pathways, as well as the generation of ROS. Moreover, UV-Tianjin-induced apoptosis was remarkably attenuated by MAPK inhibitors and ROS inhibitor. Taken together, our results indicated that UV-Tianjin exerts antitumor effects by inducing mitochondria-dependent apoptosis involving ROS generation and MAPK pathway in human osteosarcoma HOS cells.


Assuntos
Apoptose , Mitocôndrias/metabolismo , Terapia Viral Oncolítica , Osteossarcoma/terapia , Osteossarcoma/virologia , Vírus Sendai/classificação , Vírus Sendai/efeitos da radiação , Linhagem Celular Tumoral , Humanos , Sistema de Sinalização das MAP Quinases , Potencial da Membrana Mitocondrial , Mitocôndrias/enzimologia , Osteossarcoma/patologia , Espécies Reativas de Oxigênio/metabolismo
5.
Gene ; 710: 161-169, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31153884

RESUMO

The glycerol-3-phosphate dehydrogenase (GPD) gene family plays a major role in glycerol synthesis and adaptation to abiotic stresses. Few studies on GPD family genes from the halotolerant algae Dunaliella salina are available. In this study, seven DsaGPD genes were identified by mining D. salina sequencing data. Among them, DsaGPD5 contained the canonical NAD+-GPD protein domain, called si-GPD. In comparison, DsaGPD1-4 not only contained the canonical NAD+-GPD domain but also a unique domain, the haloacid dehalogenase (HAD)-like superfamily domain, in their N-terminal region, called bi-GPD. DsaGPD6, 7 contained the FAD+-GPD domain. In the transient expression system, DsaGPD1, 3, 4 were found in the cytosol of Arabidopsis thaliana protoplast, DsaGPD2, 5 in the chloroplast, and DsaGPD6, 7 in the mitochondria. MEME analysis showed that six conserved motifs were present in both si-GPDs and bi-GPDs, whereas seven highly conserved motifs were only present in bi-GPDs. The quantitative real-time PCR results showed significant induction of the DsaGPD genes under abiotic stresses, indicating their tolerance-related role in D. salina. DsaGPD2 and DsaGPD5 may be the osmoregulator form and glyceride form in the chloroplast, respectively. The evolutionary forces acting on si-GPDs and bi-GPDs were different in the same organism: bi-GPDs were under purifying selection, while si-GPDs were mainly under positive selection. Furthermore, evolution of the N_HAD domain and C_GPD domain in bi-GPDs is highly correlated. In summary, this study characterizes DsaGPD gene family members and provides useful information for elucidating the salt tolerance mechanism in D. salina.


Assuntos
Clorofíceas/enzimologia , Mineração de Dados/métodos , Glicerolfosfato Desidrogenase/química , Glicerolfosfato Desidrogenase/genética , Proteínas de Algas/química , Proteínas de Algas/genética , Motivos de Aminoácidos , Clorofíceas/genética , Cloroplastos/enzimologia , Evolução Molecular , Mitocôndrias/enzimologia , Família Multigênica , Filogenia , Domínios Proteicos , Análise de Sequência de DNA
6.
Life Sci ; 232: 116592, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31228515

RESUMO

Acetoacetyl-CoA thiolase also known as acetyl-CoA acetyltransferase (ACAT) corresponds to two enzymes, one cytosolic (ACAT2) and one mitochondrial (ACAT1), which is thought to catalyse reversible formation of acetoacetyl-CoA from two molecules of acetyl-CoA during ketogenesis and ketolysis respectively. In addition to this activity, ACAT1 is also involved in isoleucine degradation pathway. Deficiency of ACAT1 is an inherited metabolic disorder, which results from a defect in mitochondrial acetoacetyl-CoA thiolase activity and is clinically characterized with patients presenting ketoacidosis. In this review I discuss the recent findings, which unexpectedly expand the known functions of ACAT1, indicating a role for ACAT1 well beyond its classical activity. Indeed ACAT1 has recently been shown to possess an acetyltransferase activity capable of specifically acetylating Pyruvate DeHydrogenase (PDH), an enzyme involved in producing acetyl-CoA. ACAT1-dependent acetylation of PDH was shown to negatively regulate this enzyme with a consequence in Warburg effect and tumor growth. Finally, the elevated ACAT1 enzyme activity in diverse human cancer cell lines was recently reported. These important novel findings on ACAT1's function and expression in cancer cell proliferation point to ACAT1 as a potential new anti-cancer target.


Assuntos
Acetil-CoA C-Acetiltransferase/metabolismo , Neoplasias/enzimologia , Acetil-CoA C-Acetiltransferase/antagonistas & inibidores , Citosol/enzimologia , Humanos , Mitocôndrias/enzimologia , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Processamento de Proteína Pós-Traducional , Piruvato Desidrogenase (Lipoamida)/metabolismo , Esterol O-Aciltransferase/metabolismo
7.
Int J Mol Sci ; 20(8)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027213

RESUMO

Like any genome, mitochondrial DNA (mtDNA) also requires the action of topoisomerases to resolve topological problems in its maintenance, but for a long time, little was known about mitochondrial topoisomerases. The last years have brought a closer insight into the function of these fascinating enzymes in mtDNA topology regulation, replication, transcription, and segregation. Here, we summarize the current knowledge about mitochondrial topoisomerases, paying special attention to mammalian mitochondrial genome maintenance. We also discuss the open gaps in the existing knowledge of mtDNA topology control and the potential involvement of mitochondrial topoisomerases in human pathologies. While Top1mt, the only exclusively mitochondrial topoisomerase in mammals, has been studied intensively for nearly a decade, only recent studies have shed some light onto the mitochondrial function of Top2ß and Top3α, enzymes that are shared between nucleus and mitochondria. Top3α mediates the segregation of freshly replicated mtDNA molecules, and its dysfunction leads to mtDNA aggregation and copy number depletion in patients. Top2ß, in contrast, regulates mitochondrial DNA replication and transcription through the alteration of mtDNA topology, a fact that should be acknowledged due to the frequent use of Topoisomerase 2 inhibitors in medical therapy.


Assuntos
DNA Topoisomerases/metabolismo , DNA Mitocondrial/metabolismo , Animais , Eucariotos/enzimologia , Humanos , Mitocôndrias/enzimologia
8.
Parasitol Res ; 118(5): 1573-1579, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30815727

RESUMO

Parasitic infections caused by protozoan belonging to genus Eimeria are considered important for the poultry industry, due to their severe intestinal lesions and high mortality rates, causing significant economic losses. Although several mechanisms of coccidiosis pathogenesis are known, the effects of this infection on intestinal enzymes linked to adenosine triphosphate (ATP) metabolism, as creatine kinase (CK), adenylate kinase (AK), and pyruvate kinase (PK), remain unknown. Thus, the aim of this study was to evaluate whether coccidiosis impairs enzymes linked ATP metabolism in the intestine of chicken chicks. For this, 42 animals that were 2 days old were divided into two groups: uninfected (the negative control group) and experimentally infected on second day of life (the positive control group). On days 5, 10, and 15 post-infection (PI), fecal samples were collected for oocyst counts; intestinal tissue was collected in order to evaluate CK, AK, and PK activities, as well as parameters of the oxidative stress and histopathology. On days 10 and 15 PI, infected animals showed high counts of oocysts in fecal samples and intestinal lesions compared to the control group. Cytosolic CK activity was higher in infected animals on days 10 and 15 PI compared to the control group, while mitochondrial CK activity was lower on days 5, 10, and 15 PI. Also, AK activity was lower in infected animals on days 10 and 15 PI compared to control group, while no differences were observed between groups regarding PK activity. In relation to parameters of oxidative stress, intestinal lipid peroxidation and reactive oxygen species levels were higher in infected animals on days 10 and 15 PI compared to the control group, while non-protein thiol levels were lower on day 10 PI. On the 15th day, infected animals had lower body weight (P < 0.05). Based on this evidence, inhibition of mitochondrial CK activity causes an impairment of intestinal energetic homeostasis possibly through depletion on ATP levels, although the cytosolic CK activity acted as an attempt to restore the mitochondrial ATP levels through a feedback mechanism. Moreover, the impairment on energy metabolism appears to be mediated by excessive production of intestinal ROS, as well as oxidation of lipids and thiol groups.


Assuntos
Trifosfato de Adenosina/metabolismo , Adenilato Quinase/metabolismo , Galinhas/parasitologia , Coccidiose/veterinária , Creatina Quinase/metabolismo , Eimeria/metabolismo , Mitocôndrias/metabolismo , Piruvato Quinase/metabolismo , Animais , Coccidiose/metabolismo , Metabolismo Energético/fisiologia , Glicólise/fisiologia , Homeostase , Enteropatias/parasitologia , Intestinos/parasitologia , Intestinos/patologia , Mitocôndrias/enzimologia , Estresse Oxidativo , Fosforilação , Doenças das Aves Domésticas/parasitologia , Espécies Reativas de Oxigênio/metabolismo , Ganho de Peso
9.
Nat Cell Biol ; 21(4): 476-486, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30858581

RESUMO

The capacity of cells to alter bioenergetics in response to the demands of various biological processes is essential for normal physiology. The coordination of energy sensing and production with highly energy-demanding cellular processes, such as cell division, is poorly understood. Here, we show that a cell cycle-dependent mitochondrial Ca2+ transient connects energy sensing to mitochondrial activity for mitotic progression. The mitochondrial Ca2+ uniporter (MCU) mediates a rapid mitochondrial Ca2+ transient during mitosis. Inhibition of mitochondrial Ca2+ transients via MCU depletion causes spindle checkpoint-dependent mitotic delay. Cellular ATP levels drop during early mitosis, and the mitochondrial Ca2+ transients boost mitochondrial respiration to restore energy homeostasis. This is achieved through mitosis-specific MCU phosphorylation and activation by the mitochondrial translocation of energy sensor AMP-activated protein kinase (AMPK). Our results establish a critical role for AMPK- and MCU-dependent mitochondrial Ca2+ signalling in mitosis and reveal a mechanism of mitochondrial metabolic adaptation to acute cellular energy stress.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Canais de Cálcio/fisiologia , Cálcio/metabolismo , Mitocôndrias/metabolismo , Mitose , Trifosfato de Adenosina/biossíntese , Animais , Canais de Cálcio/genética , Linhagem Celular , Células Cultivadas , Células HeLa , Humanos , Camundongos Endogâmicos C57BL , Microtúbulos/metabolismo , Mitocôndrias/enzimologia
10.
Biomed Khim ; 65(1): 63-66, 2019 Jan.
Artigo em Russo | MEDLINE | ID: mdl-30816099

RESUMO

Biosensor experiments on investigation of interaction between prostacyclin synthase (PGIS) and different proteins of the cytochrome P450 monooxygenase systems were perfomed. Interaction of PGIS with microsomal (CYP21A2, CYP2E1) and mitochondrial (CYP27A1, CYP11B1, CYP11B2, CYP11A1) cytochrome P450s was detected. Kinetic and equilibrium parameters of protein complexes formation were determined. Data obtained suggest an essential role of these hemoproteins interaction in regulation of prostacyclin and thromboxane A2 biosynthesis.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Oxirredutases Intramoleculares/metabolismo , Humanos , Microssomos/enzimologia , Mitocôndrias/enzimologia , Prostaglandinas I/biossíntese , Tromboxano A2/biossíntese
11.
Arch Pharm Res ; 42(5): 436-445, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30919268

RESUMO

Mitochondrial dysfunction caused by oxidative stress appears at early stages of aging and age-related diseases. Plasma membrane redox enzymes act in a compensatory manner to decrease oxidative stress and supply reductive capacity to ensure cell survival. Plasma membrane redox enzymes transfer electrons from NAD(P)H to oxidized ubiquinone and α-tocopherol, resulting in inhibition of further oxidative damage. Plasma membrane redox enzymes and their partners are affected by aging, leading to progression of neurodegenerative disease pathogenesis. Up-regulating plasma membrane redox enzymes via calorie restriction and phytochemicals make cells more resistant to oxidative damage under stress conditions by maintaining redox homeostasis and improving mitochondrial function. Investigation into plasma membrane redox enzymes can provide mechanistic details underlying the relationships between plasma membrane redox enzymes and mitochondrial complexes and provide a good therapeutic target for prevention and delay of neurodegenerative disorders.


Assuntos
Membrana Celular/enzimologia , Mitocôndrias/enzimologia , NADH NADPH Oxirredutases/metabolismo , Doenças Neurodegenerativas/terapia , Fármacos Neuroprotetores/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Restrição Calórica , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Progressão da Doença , Regulação para Baixo/fisiologia , Radicais Livres/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Modelos Animais , NADH NADPH Oxirredutases/antagonistas & inibidores , Doenças Neurodegenerativas/patologia , Fármacos Neuroprotetores/uso terapêutico , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Regulação para Cima/efeitos dos fármacos , alfa-Tocoferol/metabolismo
12.
World J Surg Oncol ; 17(1): 24, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30700285

RESUMO

BACKGROUND: Endometrioid ovarian carcinoma and clear cell ovarian carcinoma are both classified as endometriosis-associated ovarian cancers (EAOCs). Despite the high rates of recurrence and mortality of EAOC, only a few prognostic biomarkers have been reported. Mitochondrial superoxide dismutase (SOD2) plays an important role in maintaining mitochondrial function through oxidative stress tolerance and contributes to chemotherapeutic resistance. METHODS: To clarify the clinical significance of SOD2 in EAOC, SOD2 expression was semi-quantitatively investigated by immunohistochemical analysis in 61 primary EAOC cases, and the correlations between SOD2 expression and clinicopathological data and survival were analyzed. RESULTS: Forty-six (75%) cases expressed high levels of SOD2. High SOD2 expression was associated with a poor prognosis on both univariate and multivariate analyses after adjusting for variables such as age, International Federation of Gynecology and Obstetrics (FIGO) stage, blood markers, histological type, and completion of treatment. There were 14 fatalities from 15 recurrences among 46 cases with high SOD2 expression. In contrast, only one recurrence and no fatalities were seen among 15 cases with low SOD2 expression. CONCLUSION: Increased SOD2 expression is a predictive biomarker for worse prognosis in EAOC. The therapeutic efficacy of the current standard therapeutic protocol for EAOC is limited; thus, mitochondrial SOD2 should be a therapeutic target for SOD2-abundant EAOC.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Endometrioide/enzimologia , Mitocôndrias/enzimologia , Neoplasias Ovarianas/enzimologia , Superóxido Dismutase/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Endometrioide/mortalidade , Carcinoma Endometrioide/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Espécies Reativas de Oxigênio/metabolismo
13.
Mol Cell ; 73(5): 1028-1043.e5, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733118

RESUMO

Mutations in PTEN-induced kinase 1 (PINK1) can cause recessive early-onset Parkinson's disease (PD). Import arrest results in PINK1 kinase activation specifically on damaged mitochondria, triggering Parkin-mediated mitophagy. Here, we show that PINK1 import is less dependent on Tim23 than on mitochondrial membrane potential (ΔΨm). We identified a negatively charged amino acid cluster motif that is evolutionarily conserved just C-terminal to the PINK1 transmembrane. PINK1 that fails to accumulate at the outer mitochondrial membrane, either by mutagenesis of this negatively charged motif or by deletion of Tom7, is imported into depolarized mitochondria and cleaved by the OMA1 protease. Some PD patient mutations also are defective in import arrest and are rescued by the suppression of OMA1, providing a new potential druggable target for PD. These results suggest that ΔΨm loss-dependent PINK1 import arrest does not result solely from Tim23 inactivation but also through an actively regulated "tug of war" between Tom7 and OMA1.


Assuntos
Proteínas de Membrana/metabolismo , Metaloendopeptidases/metabolismo , Mitocôndrias/enzimologia , Membranas Mitocondriais/enzimologia , Proteínas Mitocondriais/metabolismo , Doença de Parkinson/enzimologia , Proteínas Quinases/metabolismo , Motivos de Aminoácidos , Antiparkinsonianos/farmacologia , Transporte Biológico , Desenho de Drogas , Ativação Enzimática , Células HeLa , Humanos , Potencial da Membrana Mitocondrial , Proteínas de Membrana/genética , Metaloendopeptidases/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Proteínas Mitocondriais/genética , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/genética , Domínios e Motivos de Interação entre Proteínas , Proteínas Quinases/genética , Proteólise , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
14.
Drug Chem Toxicol ; 42(4): 444-450, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30777466

RESUMO

OBJECTIVE: Bufalin has been reported to kill various types of cancer including human colorectal cancer. Our previous study demonstrated that bufalin induced cell death via autophagy in HT-29 and Caco-2 colon cancer cells, but the action of bufalin remains unclear. This study was conducted to investigate the role of bufalin in other colon cancer HCT-116 and SW620 cells as well as its potential mechanism. METHODS: The effect of bufalin in HCT-116 and SW620 colon cancer cells was detected by assessing cell viability and cell death. Apoptotic cells were analyzed by Western blot and trypan blue dye exclusion assay. Mitochondrial ROS production was analyzed by flow cytometry after DCFDA and DHR-123 staining. The potential mechanism was investigated via pharmacological inhibitors. RESULTS: Bufalin had high potency against HCT-116 and SW620 cells with IC50 values of 12.823 ± 1.792 nM and 26.303 ± 2.498 nM in HCT-116 and SW620 cells, respectively. Bufalin decreased cell viability, increased cell death as well as caspase-3 downstream target (cleaved PARP) accumulation, and these actions were significantly blocked by pan-caspase inhibitor zVAD-FMK. Mechanistically, ROS production, but neither the NAD(P)H oxidase, AMPK, ERK nor p38, is responsible for bufalin-induced apoptotic cell death. Moreover, bufalin-induced ROS generation is derived from mitochondria. CONCLUSION: Bufalin significantly induces apoptosis in HCT-116 and SW620 colon cancer cells via mitochondrial ROS-mediated caspase-3 activation. We believe that our novel findings will greatly alter our current understanding on the anti-cancer mechanism of bufalin in colon cancer cells and will pave the way for further exploiting the clinical application.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bufanolídeos/farmacologia , Caspase 3/metabolismo , Mitocôndrias/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Ativação Enzimática/efeitos dos fármacos , Células HCT116 , Humanos , Mitocôndrias/enzimologia
15.
Geroscience ; 41(1): 51-67, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30729413

RESUMO

Nicotinamide adenine dinucleotide (reduced form: NADH) serves as a vital redox-energy currency for reduction-oxidation homeostasis and fulfilling energetic demands. While NADH exists as free and bound forms, only free NADH is utilized for complex I to power oxidative phosphorylation, especially important in neurons. Here, we studied how much free NADH remains available for energy production in mitochondria of old living neurons. We hypothesize that free NADH in neurons from old mice is lower than the levels in young mice and even lower in neurons from the 3xTg-AD Alzheimer's disease (AD) mouse model. To assess free NADH, we used lifetime imaging of NADH autofluorescence with 2-photon excitation to be able to resolve the pool of NADH in mitochondria, cytoplasm, and nuclei. Primary neurons from old mice were characterized by a lower free/bound NADH ratio than young neurons from both non-transgenic (NTg) and more so in 3xTg-AD mice. Mitochondrial compartments maintained 26 to 41% more reducing NADH redox state than cytoplasm for each age, genotype, and sex. Aging diminished the mitochondrial free NADH concentration in NTg neurons by 43% and in 3xTg-AD by 50%. The lower free NADH with age suggests a decline in capacity to regenerate free NADH for energetic supply to power oxidative phosphorylation which further worsens in AD. Applying this non-invasive approach, we showed the most explicit measures yet of bioenergetic deficits in free NADH with aging at the subcellular level in live neurons from in-bred mice and an AD model.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/enzimologia , Mitocôndrias/enzimologia , NAD/classificação , NAD/metabolismo , Neurônios/enzimologia , Animais , Modelos Animais de Doenças , Genótipo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência , Mitocôndrias/patologia , Neurônios/ultraestrutura , Imagem Óptica , Oxirredução , Fosforilação Oxidativa , Caracteres Sexuais , Proteínas tau/genética
16.
Nature ; 566(7743): 279-283, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30700909

RESUMO

Adaptation to the environment and extraction of energy are essential for survival. Some species have found niches and specialized in using a particular source of energy, whereas others-including humans and several other mammals-have developed a high degree of flexibility1. A lot is known about the general metabolic fates of different substrates but we still lack a detailed mechanistic understanding of how cells adapt in their use of basic nutrients2. Here we show that the closely related fasting/starvation-induced forkhead transcription factors FOXK1 and FOXK2 induce aerobic glycolysis by upregulating the enzymatic machinery required for this (for example, hexokinase-2, phosphofructokinase, pyruvate kinase, and lactate dehydrogenase), while at the same time suppressing further oxidation of pyruvate in the mitochondria by increasing the activity of pyruvate dehydrogenase kinases 1 and 4. Together with suppression of the catalytic subunit of pyruvate dehydrogenase phosphatase 1 this leads to increased phosphorylation of the E1α regulatory subunit of the pyruvate dehydrogenase complex, which in turn inhibits further oxidation of pyruvate in the mitochondria-instead, pyruvate is reduced to lactate. Suppression of FOXK1 and FOXK2 induce the opposite phenotype. Both in vitro and in vivo experiments, including studies of primary human cells, show how FOXK1 and/or FOXK2 are likely to act as important regulators that reprogram cellular metabolism to induce aerobic glycolysis.


Assuntos
Aerobiose , Fatores de Transcrição Forkhead/metabolismo , Glicólise , Células 3T3 , Animais , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/deficiência , Fatores de Transcrição Forkhead/genética , Humanos , Ácido Láctico/biossíntese , Ácido Láctico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Oxirredução , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Desidrogenase (Lipoamida)-Fosfatase/metabolismo , Complexo Piruvato Desidrogenase/química , Complexo Piruvato Desidrogenase/metabolismo , Ácido Pirúvico/metabolismo
17.
PLoS Genet ; 15(2): e1007987, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30802236

RESUMO

Drosophila melanogaster sperm reach an extraordinary long size, 1.8 mm, by the end of spermatogenesis. The mitochondrial derivatives run along the entire flagellum and provide structural rigidity for flagellar movement, but its precise function and organization is incompletely understood. The two mitochondrial derivatives differentiate and by the end of spermatogenesis the minor one reduces its size and the major one accumulates paracrystalline material inside it. The molecular constituents and precise function of the paracrystalline material have not yet been revealed. Here we purified the paracrystalline material from mature sperm and identified by mass spectrometry Sperm-Leucylaminopeptidase (S-Lap) family members as important constituents of it. To study the function of S-Lap proteins we show the characterization of classical mutants and RNAi lines affecting of the S-Lap genes and the analysis of their mutant phenotypes. We show that the male sterile phenotype of the S-Lap mutants is caused by defects in paracrystalline material accumulation and abnormal structure of the elongated major mitochondrial derivatives. Our work shows that S-Lap proteins localize and accumulate in the paracrystalline material of the major mitochondrial derivative. Therefore, we propose that S-Lap proteins are important constituents of the paracrystalline material of Drosophila melanogaster sperm.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Leucil Aminopeptidase/metabolismo , Espermatozoides/enzimologia , Animais , Animais Geneticamente Modificados , Cristalização , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Fertilidade/genética , Fertilidade/fisiologia , Genes de Insetos , Infertilidade Masculina/enzimologia , Infertilidade Masculina/genética , Leucil Aminopeptidase/química , Leucil Aminopeptidase/genética , Masculino , Microscopia Eletrônica de Transmissão , Mitocôndrias/química , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Mutação , Interferência de RNA , Espermatogênese/genética , Espermatogênese/fisiologia , Espermatozoides/fisiologia , Espermatozoides/ultraestrutura
18.
Parasit Vectors ; 12(1): 80, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30744665

RESUMO

BACKGROUND: In Kenya, malaria remains a major public health menace equally affecting the semi-arid to arid ecologies. However, entomologic knowledge of malaria vectors in such areas remains poor. METHODS: Morphologically-identified wild-caught Anopheles funestus (s.l.) specimens trapped outdoors from the semi-arid to arid area of Kacheliba, West Pokot County, Kenya, were analysed by PCR and sequencing for species identification, malaria parasite infection and host blood-meal sources. RESULTS: Three hundred and thirty specimens were analysed to identify sibling species of the An. funestus group, none of which amplified using the available primers; two were infected with Plasmodium falciparum and Plasmodium ovale, separately, while 84% (n = 25) of the blood-fed specimens had fed on humans. Mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS2) sequences of 55 specimens (Plasmodium-positive, blood-fed and Plasmodium-negative) did not match reference sequences, possibly suggesting a previously unreported species, resolving as two clades. CONCLUSIONS: Our findings indicate the existence of yet-to-be identified and described anopheline species with a potential as malaria vectors in Kenya.


Assuntos
Anopheles/classificação , Malária/transmissão , Mosquitos Vetores/classificação , Plasmodium falciparum/fisiologia , Animais , Anopheles/genética , Anopheles/parasitologia , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Ecologia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Monitoramento Ambiental , Feminino , Humanos , Quênia/epidemiologia , Malária/epidemiologia , Malária/parasitologia , Mitocôndrias/enzimologia , Mosquitos Vetores/genética , Mosquitos Vetores/parasitologia , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
19.
Plant Cell Physiol ; 60(6): 1239-1249, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30796840

RESUMO

Malonyl-acyl carrier protein (ACP) is a key building block for the synthesis of fatty acids, which are important components of cell membranes, storage oils and lipid-signaling molecules. Malonyl CoA-ACP malonyltransferase (MCAMT) catalyzes the production of malonyl-ACP and CoA from malonyl-CoA and ACP. Here, we report that MCAMT plays a critical role in cell division and has the potential to increase the storage oil content in Arabidopsis. The quantitative real-time PCR and MCAMT promoter:GUS analyses showed that MCAMT is predominantly expressed in shoot and root apical meristems, leaf hydathodes and developing embryos. The fluorescent signals of MCAMT:eYFP were observed in both chloroplasts and mitochondria of tobacco leaf protoplasts. In particular, the N-terminal region (amino acid residues 1-30) of MCAMT was required for mitochondrial targeting. The Arabidopsis mcamt-1 and -2 mutants exhibited an embryo-lethal phenotype because of the arrest of embryo development at the globular stage. The transgenic Arabidopsis expressing antisense MCAMT RNA showed growth retardation caused by the defects in cell division. The overexpression of MCAMT driven by the promoter of the senescence-associated 1 (SEN1) gene, which is predominantly expressed in developing seeds, increased the seed yield and storage oil content of Arabidopsis. Taken together, the plastidial and mitochondrial MCAMT is essential for Arabidopsis cell division and is a novel genetic resource useful for enhancing storage oil content in oilseed crops.


Assuntos
Proteína de Transporte de Acila S-Maloniltransferase/metabolismo , Proteínas de Arabidopsis/metabolismo , Divisão Celular , Mitocôndrias/enzimologia , Óleos Vegetais/metabolismo , Plastídeos/enzimologia , Arabidopsis/enzimologia , Arabidopsis/metabolismo , Mitocôndrias/metabolismo , Plantas Geneticamente Modificadas , Plastídeos/metabolismo , Tabaco
20.
Artigo em Inglês | MEDLINE | ID: mdl-30658134

RESUMO

Mitochondrial function is critical to support aerobic metabolism through the production of ATP, and deficiencies in mitochondrial bioenergetics will directly impact the performance capacity of highly aerobic tissues such as the myocardium. Cardiac function in fish has been shown to be negatively affected by crude oil exposure, however, the mechanism for this adverse response is largely unexplored. We hypothesized that lipophilic polycyclic aromatic hydrocarbons (PAHs) found in crude oil disrupt the electron transport system (ETS) ultimately leading to mitochondrial dysfunction. In this study, mitochondrial respiration and ADP affinity we measured using high resolution respirometery in permeabilized cardiac muscle fibers of young adult Mahi-mahi (Coryphaena hippurus) after an acute (24 h) whole animal crude oil exposure. Oil exposure reduced both complex I-fueled ADP stimulated respiration (OXPHOSCI) and complex I,II-fueled ADP stimulated respiration (OXPHOSCI, CII) by 33%,while complex II-fueled ADP stimulated respiration (OXPHOSCII) was reduced by 25%. These changes were found without changes in enzyme activity or mitochondrial density between control and oil exposed Mahi. Additionally, mitochondrial affinity for ADP was decreased three-fold after acute exposure to crude oil. We purpose that acute crude oil exposure selectively impairs mitochondrial complexes of the electron transport system and ATP supply to the cell. This limited ATP supply could present several challenges to a predatory animal like the mahi; including a reliance on anaerobic metabolism and ultimately cell or tissue death as metabolic substrates are rapidly depleted. However, the impact of this impairment may only be evident under periods of increased aerobic metabolic demand.


Assuntos
Difosfato de Adenosina/metabolismo , Mitocôndrias/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Perciformes , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Mitocôndrias/enzimologia , Miócitos Cardíacos/metabolismo , Consumo de Oxigênio/efeitos dos fármacos
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