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1.
PLoS Negl Trop Dis ; 14(9): e0008568, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32936798

RESUMO

Trypanosoma brucei is a single celled eukaryotic parasite and the causative agent of human African trypanosomiasis and nagana in cattle. Aside from its medical relevance, T. brucei has also been key to the discovery of several general biological principles including GPI-anchoring, RNA-editing and trans-splicing. The parasite contains a single mitochondrion with a singular genome. Recent studies have identified several molecular components of the mitochondrial genome segregation machinery (tripartite attachment complex, TAC), which connects the basal body of the flagellum to the mitochondrial DNA of T. brucei. The TAC component in closest proximity to the mitochondrial DNA is TAC102. Here we apply and compare three different approaches (proximity labelling, immunoprecipitation and yeast two-hybrid) to identify novel interactors of TAC102 and subsequently verify their localisation. Furthermore, we establish the direct interaction of TAC102 and p166 in the unilateral filaments of the TAC.


Assuntos
DNA Mitocondrial/genética , Imunoprecipitação , Proteínas de Protozoários/genética , Técnicas do Sistema de Duplo-Híbrido , Animais , Bovinos , Doenças dos Bovinos/parasitologia , DNA de Cinetoplasto/metabolismo , Flagelos/metabolismo , Genoma Mitocondrial/genética , Humanos , Mitocôndrias/genética , Mitocôndrias/fisiologia , Trypanosoma brucei brucei/genética , Tripanossomíase Africana/veterinária
2.
Proc Natl Acad Sci U S A ; 117(37): 23165-23173, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868448

RESUMO

To engineer Mo-dependent nitrogenase function in plants, expression of the structural proteins NifD and NifK will be an absolute requirement. Although mitochondria have been established as a suitable eukaryotic environment for biosynthesis of oxygen-sensitive enzymes such as NifH, expression of NifD in this organelle has proven difficult due to cryptic NifD degradation. Here, we describe a solution to this problem. Using molecular and proteomic methods, we found NifD degradation to be a consequence of mitochondrial endoprotease activity at a specific motif within NifD. Focusing on this functionally sensitive region, we designed NifD variants comprising between one and three amino acid substitutions and distinguished several that were resistant to degradation when expressed in both plant and yeast mitochondria. Nitrogenase activity assays of these resistant variants in Escherichia coli identified a subset that retained function, including a single amino acid variant (Y100Q). We found that other naturally occurring NifD proteins containing alternate amino acids at the Y100 position were also less susceptible to degradation. The Y100Q variant also enabled expression of a NifD(Y100Q)-linker-NifK translational polyprotein in plant mitochondria, confirmed by identification of the polyprotein in the soluble fraction of plant extracts. The NifD(Y100Q)-linker-NifK retained function in bacterial nitrogenase assays, demonstrating that this polyprotein permits expression of NifD and NifK in a defined stoichiometry supportive of activity. Our results exemplify how protein design can overcome impediments encountered when expressing synthetic proteins in novel environments. Specifically, these findings outline our progress toward the assembly of the catalytic unit of nitrogenase within mitochondria.


Assuntos
Genes Bacterianos/genética , Mitocôndrias/genética , Mitocôndrias/fisiologia , Proteínas de Plantas/genética , Plantas/genética , Substituição de Aminoácidos/genética , Escherichia coli/genética , Fixação de Nitrogênio/genética , Nitrogenase/genética , Poliproteínas/genética , Proteômica/instrumentação
3.
Mutat Res ; 785: 108320, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32800274

RESUMO

It is well established that maternal age is associated with a rapid decline in the production of healthy and high-quality oocytes resulting in reduced fertility in women older than 35 years of age. In particular, chromosome segregation errors during meiotic divisions are increasingly common and lead to the production of oocytes with an incorrect number of chromosomes, a condition known as aneuploidy. When an aneuploid oocyte is fertilized by a sperm it gives rise to an aneuploid embryo that, except in rare situations, will result in a spontaneous abortion. As females advance in age, they are at higher risk of infertility, miscarriage, or having a pregnancy affected by congenital birth defects such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Turner syndrome (monosomy X). Here, we review the potential molecular mechanisms associated with increased chromosome segregation errors during meiosis as a function of maternal age. Our review shows that multiple exogenous and endogenous factors contribute to the age-related increase in oocyte aneuploidy. Specifically, the weight of evidence indicates that recombination failure, cohesin deterioration, spindle assembly checkpoint (SAC) disregulation, abnormalities in post-translational modification of histones and tubulin, and mitochondrial dysfunction are the leading causes of oocyte aneuploidy associated with maternal aging. There is also growing evidence that dietary and other bioactive interventions may mitigate the effect of maternal aging on oocyte quality and oocyte aneuploidy, thereby improving fertility outcomes. Maternal age is a major concern for aneuploidy and genetic disorders in the offspring in the context of an increasing proportion of mothers having children at increasingly older ages. A better understanding of the mechanisms associated with maternal aging leading to aneuploidy and of intervention strategies that may mitigate these detrimental effects and reduce its occurrence are essential for preventing abnormal reproductive outcomes in the human population.


Assuntos
Aneuploidia , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos/genética , Anormalidades Congênitas/genética , Idade Materna , Anormalidades Congênitas/prevenção & controle , Feminino , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Meiose/genética , Mitocôndrias/fisiologia , Oócitos/fisiologia
4.
PLoS Pathog ; 16(8): e1008810, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817704

RESUMO

Sterol 14-α-demethylase (C14DM) is a key enzyme in the biosynthesis of sterols and the primary target of azoles. In Leishmania major, genetic or chemical inactivation of C14DM leads to accumulation of 14-methylated sterol intermediates and profound plasma membrane abnormalities including increased fluidity and failure to maintain ordered membrane microdomains. These defects likely contribute to the hypersensitivity to heat and severely reduced virulence displayed by the C14DM-null mutants (c14dm‾). In addition to plasma membrane, sterols are present in intracellular organelles. In this study, we investigated the impact of C14DM ablation on mitochondria. Our results demonstrate that c14dm‾ mutants have significantly higher mitochondrial membrane potential than wild type parasites. Such high potential leads to the buildup of reactive oxygen species in the mitochondria, especially under nutrient-limiting conditions. Consistent with these mitochondrial alterations, c14dm‾ mutants show impairment in respiration and are heavily dependent on glucose uptake and glycolysis to generate energy. Consequently, these mutants are extremely sensitive to glucose deprivation and such vulnerability can be rescued through the supplementation of glucose or glycerol. In addition, the accumulation of oxidants may also contribute to the heat sensitivity exhibited by c14dm‾. Finally, genetic or chemical ablation of C14DM causes increased susceptibility to pentamidine, an antimicrobial agent with activity against trypanosomatids. In summary, our investigation reveals that alteration of sterol synthesis can negatively affect multiple cellular processes in Leishmania parasites and make them vulnerable to clinically relevant stress conditions.


Assuntos
Leishmania major/enzimologia , Leishmania major/fisiologia , Leishmaniose Cutânea/patologia , Mitocôndrias/fisiologia , Proteínas de Protozoários/metabolismo , Esterol 14-Desmetilase/metabolismo , Esteróis/metabolismo , Humanos , Leishmaniose Cutânea/metabolismo , Leishmaniose Cutânea/parasitologia , Potencial da Membrana Mitocondrial , Proteínas de Protozoários/genética , Espécies Reativas de Oxigênio/metabolismo , Esterol 14-Desmetilase/genética
5.
Science ; 369(6505): 858-862, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32792401

RESUMO

The conversion of neural stem cells into neurons is associated with the remodeling of organelles, but whether and how this is causally linked to fate change is poorly understood. We examined and manipulated mitochondrial dynamics during mouse and human cortical neurogenesis. We reveal that shortly after cortical stem cells have divided, daughter cells destined to self-renew undergo mitochondrial fusion, whereas those that retain high levels of mitochondria fission become neurons. Increased mitochondria fission promotes neuronal fate, whereas induction of mitochondria fusion after mitosis redirects daughter cells toward self-renewal. This occurs during a restricted time window that is doubled in human cells, in line with their increased self-renewal capacity. Our data reveal a postmitotic period of fate plasticity in which mitochondrial dynamics are linked with cell fate.


Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Mitocôndrias/fisiologia , Dinâmica Mitocondrial , Mitose , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Neurônios/citologia , Animais , Córtex Cerebral/citologia , Feminino , Células HEK293 , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Masculino , Camundongos , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Sirtuínas/metabolismo
6.
Proc Natl Acad Sci U S A ; 117(35): 21731-21739, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32801213

RESUMO

Ca2+ uptake by mitochondria regulates bioenergetics, apoptosis, and Ca2+ signaling. The primary pathway for mitochondrial Ca2+ uptake is the mitochondrial calcium uniporter (MCU), a Ca2+-selective ion channel in the inner mitochondrial membrane. MCU-mediated Ca2+ uptake is driven by the sizable inner-membrane potential generated by the electron-transport chain. Despite the large thermodynamic driving force, mitochondrial Ca2+ uptake is tightly regulated to maintain low matrix [Ca2+] and prevent opening of the permeability transition pore and cell death, while meeting dynamic cellular energy demands. How this is accomplished is controversial. Here we define a regulatory mechanism of MCU-channel activity in which cytoplasmic Ca2+ regulation of intermembrane space-localized MICU1/2 is controlled by Ca2+-regulatory mechanisms localized across the membrane in the mitochondrial matrix. Ca2+ that permeates through the channel pore regulates Ca2+ affinities of coupled inhibitory and activating sensors in the matrix. Ca2+ binding to the inhibitory sensor within the MCU amino terminus closes the channel despite Ca2+ binding to MICU1/2. Conversely, disruption of the interaction of MICU1/2 with the MCU complex disables matrix Ca2+ regulation of channel activity. Our results demonstrate how Ca2+ influx into mitochondria is tuned by coupled Ca2+-regulatory mechanisms on both sides of the inner mitochondrial membrane.


Assuntos
Canais de Cálcio/metabolismo , Cálcio/metabolismo , Mitocôndrias/metabolismo , Apoptose , Transporte Biológico , Cálcio/fisiologia , Canais de Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/fisiologia , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/fisiologia , Citoplasma/metabolismo , Citosol/metabolismo , Células HEK293 , Células HeLa , Humanos , Potencial da Membrana Mitocondrial/fisiologia , Mitocôndrias/fisiologia , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/fisiologia , Membranas Mitocondriais/metabolismo , Membranas Mitocondriais/fisiologia , Oxirredução , Multimerização Proteica , Transdução de Sinais
7.
Metabolism ; 111: 154341, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32810486

RESUMO

BACKGROUND: Biallelic loss of function variants in AGPAT2, encoding 1-acylglycerol-3-phosphate O-acyltransferase 2, cause congenital generalized lipodystrophy type 1, a disease characterized by near total loss of white adipose tissue and metabolic complications. Agpat2 deficient (Agpat2-/-) mice completely lacks both white and interscapular brown adipose tissue (iBAT). The objective of the present study was to characterize the effects of AGPAT2 deficiency in brown adipocyte differentiation. METHODS: Preadipocytes obtained from newborn (P0.5) Agpat2-/- and wild type mice iBAT were differentiated into brown adipocytes, compared by RNA microarray, RT-qPCR, High-Content Screening (HCS), western blotting and electron microscopy. RESULTS: 1) Differentiated Agpat2-/- brown adipocytes have fewer lipid-laden cells and lower abundance of Pparγ, Pparα, C/ebpα and Pgc1α, both at the mRNA and protein levels, compared those to wild type cells. Prmd16 levels were equivalent in both, Agpat2-/- and wild type, while Ucp1 was only induced in wild type cells, 2) These differences were not due to lower abundance of preadipocytes, 3) Differentiated Agpat2-/- brown adipocytes are enriched in the mRNA abundance of genes participating in interferon (IFN) type I response, whereas genes involved in mitochondrial homeostasis were decreased, 4) Mitochondria in differentiated Agpat2-/- brown adipocytes had altered morphology and lower mass and contacting sites with lipid droplets concomitant with lower levels of Mitofusin 2 and Perlipin 5. CONCLUSION: AGPAT2 is necessary for normal brown adipose differentiation. Its absence results in a lower proportion of lipid-laden cells, increased expression of interferon-stimulated genes (ISGs) and alterations in mitochondrial morphology, mass and fewer mitochondria to lipid droplets contacting sites in differentiated brown adipocytes.


Assuntos
Aciltransferases/metabolismo , Adipócitos Marrons/metabolismo , Adipogenia/fisiologia , Tecido Adiposo Marrom/metabolismo , Expressão Gênica/fisiologia , Interferon Tipo I/metabolismo , Mitocôndrias/metabolismo , Adipócitos Marrons/fisiologia , Tecido Adiposo Marrom/fisiologia , Animais , Diferenciação Celular/fisiologia , GTP Fosfo-Hidrolases/metabolismo , Homeostase/fisiologia , Camundongos , Mitocôndrias/fisiologia , RNA Mensageiro/metabolismo
8.
Int J Surg ; 81: 47-54, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32738546

RESUMO

Globally, a staggering 310 million major surgeries are performed each year; around 40 to 50 million in USA and 20 million in Europe. It is estimated that 1-4% of these patients will die, up to 15% will have serious postoperative morbidity, and 5-15% will be readmitted within 30 days. An annual global mortality of around 8 million patients places major surgery comparable with the leading causes of death from cardiovascular disease and stroke, cancer and injury. If surgical complications were classified as a pandemic, like HIV/AIDS or coronavirus (COVID-19), developed countries would work together and devise an immediate action plan and allocate resources to address it. Seeking to reduce preventable deaths and post-surgical complications would save billions of dollars in healthcare costs. Part of the global problem resides in differences in institutional practice patterns in high- and low-income countries, and part from a lack of effective perioperative drug therapies to protect the patient from surgical stress. We briefly review the history of surgical stress and provide a path forward from a systems-based approach. Key to progress is recognizing that the anesthetized brain is still physiologically 'awake' and responsive to the sterile stressors of surgery. New intravenous drug therapies are urgently required after anesthesia and before the first incision to prevent the brain from switching to sympathetic overdrive and activating secondary injury progression such as hyperinflammation, coagulopathy, immune activation and metabolic dysfunction. A systems-based approach targeting central nervous system-mitochondrial coupling may help drive research to improve outcomes following major surgery in civilian and military medicine.


Assuntos
Complicações Pós-Operatórias/etiologia , Procedimentos Cirúrgicos Operatórios/mortalidade , Saúde Global , Glicocálix/fisiologia , Humanos , Sistema Hipotálamo-Hipofisário/fisiologia , Mitocôndrias/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Complicações Pós-Operatórias/prevenção & controle , Estresse Fisiológico , Procedimentos Cirúrgicos Operatórios/efeitos adversos
9.
PLoS One ; 15(8): e0234492, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790760

RESUMO

Endothelial injury is a common manifestation in IgA nephropathy (IgAN). After the previous identification of the upregulated soluble fms-like tyrosine kinase-1 (sFlt-1) correlated with endothelial injury in IgAN, in the present study, we further explored the role of sFlt-1 in endothelial injury in IgAN. We enrolled 72 patients with IgAN and detected the sFlt-1 levels. The polymeric IgA1 (pIgA1) complexes were isolated from the pooled plasma samples of another 10 patients with IgAN. Apoptosis proteins were detected in cultured human umbilical vein endothelial cells (HUVECs) with the stimulation of recombinant sFlt-1 or the caspase-9 inhibitor Z-LEHD-FMK. We identified there were positive correlations between sFlt-1 and IgA-IgG complex as well as vWF levels in patients with IgAN. The sFlt-1 levels in HUVECs were significantly upregulated by pIgA1 complex derived from IgAN patients in a concentration-dependent manner. The proliferation ability of HUVECs was damaged when stimulated with sFlt-1 protein in a time- and dose- dependent manner. And the apoptosis rate was up-regulated significantly as the stimulation concentrations of sFlt-1 increased. We found sFlt-1 challenge could significantly increase the expression of vWF. In addition, sFlt-1 increased the levels of caspase-9, caspase-3, Bax and mitochondrial membrane potential; facilitated the release of cytochrome C from mitochondria to cytoplasma. In contrast, Z-LEHD-FMK attenuated high sFlt-1-induced HUVECs apoptosis. In conclusion, our study demonstrated that sFlt-1 expression was up-regulated by the challenge of pIgA1 complex derived from patients with IgAN. Furthermore, increased sFlt-1 facilitated human umbilical vein endothelial cells apoptosis via the mitochondrial-dependent pathway.


Assuntos
Endotélio Vascular/fisiopatologia , Glomerulonefrite por IGA/fisiopatologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Adulto , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Proteínas Reguladoras de Apoptose/fisiologia , Caspase 9/efeitos dos fármacos , Inibidores de Caspase/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Feminino , Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Oligopeptídeos/farmacologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Adulto Jovem
10.
Ecotoxicol Environ Saf ; 204: 111051, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32763565

RESUMO

The present study was performed to determine the effect of waterborne cadmium (Cd) exposure on oxidative stress, autophagy and mitochondrial dysfunction, and to explore the mechanism of Cd-induced liver damage in freshwater teleost Procypris merus. To this end, P. merus were exposed to waterborne 0, 0.25 and 0.5 mg/L Cd for 30 days (equal to 0, 2.22 and 4.45 µmol Cd/l). The waterborne Cd exposure significantly increased hepatic Cd accumulation and impaired histological structure of the liver of P. merus. both low and high-dose waterborne Cd exposure induced oxidative stress in the liver of P. merus, through increases Malondialdehyde (MDA) and reactive oxide species (ROS) accumulation in the liver. The Cd-induced oxidative stress in liver may result from reduction of enzyme activities (superoxide dismutases (SOD), catalases (CAT), GSH-S-transferases (GST)) and transcriptional expression of antioxidant related genes (gpx1, gpx2, cata, gsta1, sod1). Furthermore, the present study showed that waterborne Cd exposure decreased the transcriptional factor (nrf2) expression, which might lead to the down-regulation of antioxidant gene expression. Transmission electron microscopy (TEM) observations demonstrated that waterborne Cd exposure induced autophagy in the liver of P. merus. Gene expression analysis showed that waterborne Cd exposure also induced mRNA expression of a set of genes (beclin1, ulk1, atg5, lc3a, atg4b, atg9a, and p62) involved in the autophagy process, indicating that the influence of Cd on autophagy involved transcription regulation of autophagy gene expression. Waterborne Cd exposure induced a sharp decrease in ATP content in the liver of P. merus. In addition, the expression of mitochondrial function genes (sdha, cox4i1, cox1, atp5f1, and mt-cyb) are significantly decreased in the liver of P. merus in Cd treated groups, manifesting the suppression of Cd on mitochondrial energy metabolism. Taken together, our experiments demonstrate that waterborne Cd exposure induced oxidative stress, autophagy and mitochondrial dysfunction in the liver of P. merus. These results may contribute to the understanding of mechanisms that hepatotoxicity of Cd in teleost.


Assuntos
Antioxidantes/fisiologia , Autofagia/efeitos dos fármacos , Cádmio/toxicidade , Cyprinidae/fisiologia , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Fígado/fisiologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Distribuição Aleatória
11.
Ecotoxicol Environ Saf ; 204: 111040, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798748

RESUMO

Tebuconazole (TEB) is a common triazole fungicide that is widely used throughout the world in agriculture applications. We previously reported that TEB induces cardiac toxicity in rats. The aim of this study was to investigate the underlying mechanism of the toxicity induced by TEB in cardiac cells. TEB induced dose-dependent cell death in H9c2 cardiomyoblasts and in adult rat ventricular myocytes (ARVM). The comet assay and western blot analysis showed a concentration-dependent increase in DNA damage and in p53 and p21 protein levels 24 h after TEB treatment. Our findings also showed that TEB triggered the mitochondrial pathway of apoptosis as evidenced by a loss of mitochondrial transmembrane potential (ΔΨm), an increase in Bax/Bcl-2 ratio, an activation of caspase-9 and caspase-3, a cleavage of poly (ADP-ribose) polymerase (PARP) and an increase in the proportion of cells in the sub-G1 phase. In addition, TEB promoted ROS production in cardiac cells and consequently increased the amounts of MDA, the end product of lipid peroxidation. Treatment of cardiomyocytes with the ROS scavenger N-acetylcysteine reduced TEB-induced DNA damage and activation of the mitochondrial pathway of apoptosis. These results indicate that the genotoxic and cytotoxic effects of TEB are mediated through a ROS-dependent pathway in cardiac cells.


Assuntos
Apoptose , Cardiotoxicidade/metabolismo , Dano ao DNA , Fungicidas Industriais/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Triazóis/toxicidade , Animais , Cardiotoxicidade/etiologia , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Ratos , Ratos Wistar
12.
Science ; 369(6501): 325-329, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32675375

RESUMO

Chromatin instability and mitochondrial decline are conserved processes that contribute to cellular aging. Although both processes have been explored individually in the context of their distinct signaling pathways, the mechanism that determines which process dominates during aging of individual cells is unknown. We show that interactions between the chromatin silencing and mitochondrial pathways lead to an epigenetic landscape of yeast replicative aging with multiple equilibrium states that represent different types of terminal states of aging. The structure of the landscape drives single-cell differentiation toward one of these states during aging, whereby the fate is determined quite early and is insensitive to intracellular noise. Guided by a quantitative model of the aging landscape, we genetically engineered a long-lived equilibrium state characterized by an extended life span.


Assuntos
Senescência Celular , Mitocôndrias/fisiologia , Saccharomyces cerevisiae , Cromatina/fisiologia , Montagem e Desmontagem da Cromatina , DNA Fúngico , Inativação Gênica
13.
Int Arch Allergy Immunol ; 181(8): 629-634, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32564017

RESUMO

The difference between the female and male immune response to COVID-19 infection, and infections in general, is multifactorial. The well-known determiners of the immune response, such as X and Y chromosomes, sex hormones, and microbiota, are functionally interconnected and influence each other in shaping the organism's immunity. We focus our commentary on the interplay between the genetic sex and mitochondria and how this may affect a sex-dependent immune response in COVID-19 infection. Realizing the existence of these interactions may help in designing novel methods or fine-tuning the existing and routine therapies to fight COVID-19 and other infections.


Assuntos
Betacoronavirus , Infecções por Coronavirus/imunologia , Mitocôndrias/fisiologia , Pneumonia Viral/imunologia , Cromossomos Sexuais/fisiologia , Infecções por Coronavirus/tratamento farmacológico , Feminino , Humanos , Masculino , Melatonina/uso terapêutico , Pandemias , Pneumonia Viral/tratamento farmacológico , Caracteres Sexuais
14.
Int J Infect Dis ; 97: 303-305, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32497811

RESUMO

The coronavirus 2 (SARS-CoV-2) pandemic is viciously spreading through the continents with rapidly increasing mortality rates. Current management of COVID-19 is based on the premise that respiratory failure is the leading cause of mortality. However, mounting evidence links accelerated pathogenesis in gravely ill COVID-19 patients to a hyper-inflammatory state involving a cytokine storm. Several components of the heightened inflammatory state were addressed as therapeutic targets. Another key component of the heightened inflammatory state is hyper-ferritinemia which reportedly identifies patients with increased mortality risk. In spite of its strong association with mortality, it is not yet clear if hyper-ferritinemia in COVID-19 patients is merely a systemic marker of disease progression, or a key modulator in disease pathogenesis. Here we address implications of a possible role for hyper-ferritinemia, and altered iron homeostasis in COVID-19 pathogenesis, and potential therapeutic targets in this regard.


Assuntos
Infecções por Coronavirus/patologia , Sobrecarga de Ferro/virologia , Pneumonia Viral/patologia , Betacoronavirus , Infecções por Coronavirus/mortalidade , Síndrome da Liberação de Citocina/virologia , Ferroptose , Hepcidinas/fisiologia , Humanos , Inflamação , Ferro/sangue , Mitocôndrias/patologia , Mitocôndrias/fisiologia , Estresse Oxidativo , Pandemias , Pneumonia Viral/mortalidade
15.
Artigo em Inglês | MEDLINE | ID: mdl-32551862

RESUMO

In the last few months, the number of cases of a new coronavirus-related disease (COVID-19) rose exponentially, reaching the status of a pandemic. Interestingly, early imaging studies documented that pulmonary vascular thickening was specifically associated with COVID-19 pneumonia, implying a potential tropism of the virus for the pulmonary vasculature. Moreover, SARS-CoV-2 infection is associated with inflammation, hypoxia, oxidative stress, mitochondrial dysfunction, DNA damage, and lung coagulopathy promoting endothelial dysfunction and microthrombosis. These features are strikingly similar to what is seen in pulmonary vascular diseases. Although the consequences of COVID-19 on the pulmonary circulation remain to be explored, several viruses have been previously thought to be involved in the development of pulmonary vascular diseases. Patients with preexisting pulmonary vascular diseases also appear at increased risk of morbidity and mortality. The present article reviews the molecular factors shared by coronavirus infection and pulmonary vasculature defects, and the clinical relevance of pulmonary vascular alterations in the context of COVID-19.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Pneumopatias/etiologia , Pulmão/irrigação sanguínea , Pulmão/fisiopatologia , Pneumonia Viral/complicações , Betacoronavirus/patogenicidade , Betacoronavirus/fisiologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/virologia , Citocinas/sangue , Dano ao DNA , Traumatismos Cardíacos/etiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Hipóxia/etiologia , Mediadores da Inflamação/sangue , Pulmão/virologia , Pneumopatias/fisiopatologia , Pneumopatias/virologia , Mitocôndrias/fisiologia , Miocárdio , Estresse Oxidativo , Pandemias , Peptidil Dipeptidase A/fisiologia , Pneumonia Viral/fisiopatologia , Pneumonia Viral/virologia , Circulação Pulmonar , Embolia Pulmonar/etiologia , Receptores Virais/fisiologia , Fatores de Risco , Vasculite/etiologia
16.
Chemosphere ; 258: 127305, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32563914

RESUMO

Chronic arsenic toxicity has become a global concern due to its adverse pathophysiological outcome and carcinogenic potential. It is already established that arsenic induced reactive oxygen species alters mitochondrial functionality. Major regulatory genes for mitochondrial biogenesis, i.e., PGC1α, Tfam, NRF1and NRF2 are located in the nucleus. As a result, mitochondria-nucleus crosstalk is crucial for proper mitochondrial function. This previous hypothesis led us to investigateinvolvement of epigenetic alteration behindenhanced mitochondrial biogenesis in chronic arsenic exposure. An extensive case-control study was conducted with 390 study participants (unexposed, exposed without skin lesion, exposed with skin lesion and exposed skin tumour) from highly arsenic exposed areas ofWest Bengal, India. Methylation specific PCRrevealed significant promoter hypomethylation oftwo key biogenesis regulatory genes, PGC1αandTfam in arsenic exposed individuals and also in skin tumour tissues. Linear regression analysis indicated significant negative correlation between urinary arsenic concentration and promoter methylation status. Increased expression of biogenesis regulatory genes wasobtained by quantitative real-time PCR analysis. Moreover, altered mitochondrial fusion-fission regulatory gene expression was also observed in skin tumour tissues. miR663, having tumour suppressor gene like function was known to be epigenetically regulated through mitochondrial retrograde signal. Promoter hypermethylation with significantly decreased expression of miR663 was found in skin cancer tissues compared to non-cancerous control tissue. In conclusion, results indicated crucial role of epigenetic alteration in arsenic induced mitochondrial biogenesis and arsenical skin carcinogenesis for the first time. However, further mechanistic studies are necessary for detailed understanding of mitochondria-nucleus crosstalk in arsenic perturbation.


Assuntos
Arsênico/toxicidade , Epigênese Genética , Mitocôndrias/fisiologia , Arsênico/metabolismo , Intoxicação por Arsênico , Carcinogênese/induzido quimicamente , Estudos de Casos e Controles , Metilação de DNA , Epigenômica , Feminino , Humanos , Índia , Masculino , MicroRNAs/metabolismo , Mitocôndrias/metabolismo , Biogênese de Organelas , Regiões Promotoras Genéticas , Dermatopatias/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente
17.
Life Sci ; 254: 117812, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32428596

RESUMO

AIMS: Since the role of the major mitochondrial NAD+-dependent deacetylase, sirtuin 3 (Sirt3), is differential in cancer, opposite to the well-known tumor-suppressing effect of hyperoxia, this study aimed to investigate the role of Sirt3 in triple-negative breast cancer (TNBC) cell line MDA-MB-231 upon hyperoxic (95% O2) conditions. MAIN METHODS: MDA-MB-231 cells were stably transfected with Flag-tagged Sirt-3 or empty plasmid. Western blot and real-time PCR were used to monitor the expression of proteins or genes involved in mitochondrial biogenesis, metabolic regulation and antioxidant defense. Immunocytochemistry and confocal microscopy were used to confirm the cellular localization and abundance of proteins. Flow cytometry was used to analyze mitochondrial mass, potential and ROS production, and MTT test as a measure of metabolic activity. Mitotic index analysis, colony-forming unit assay, DNA damage and Annexin V-FITC analyses were used to assess the differences in the growth and apoptosis rate. KEY FINDINGS: Although Sirt3 seemed to improve mitochondrial properties by increasing mitochondrial mass and potential, metabolic activity (Warburg effect) and antioxidative defense (SOD2, Cat), it also increased mitochondrial ROS, induced DNA damage, timp-1 expression, formation of multinucleated cells and apoptosis, and finally markedly reduced the proliferation of MDA-MB-231 cells. All these effects were even more evident upon the hyperoxic treatment, thus pointing towards combined negative effect of Sirt3 and hyperoxia on MDA-MB-231 cells. SIGNIFICANCE: Both Sirt3 and hyperoxia, alone or in combination, have the potential to negatively affect the malignant properties of the MDA-MB-231 cells and should be further explored as a possible therapy for TNBC.


Assuntos
Sobrevivência Celular/fisiologia , Hiperóxia/fisiopatologia , Mitocôndrias/fisiologia , Sirtuína 3/fisiologia , Neoplasias de Mama Triplo Negativas/fisiopatologia , Anexinas/metabolismo , Apoptose/fisiologia , Carcinogênese , Linhagem Celular Tumoral , Dano ao DNA , Regulação Neoplásica da Expressão Gênica , Humanos , Potencial da Membrana Mitocondrial/fisiologia , Mitocôndrias/metabolismo , Índice Mitótico , Proteínas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/genética , Células-Tronco , Transfecção , Neoplasias de Mama Triplo Negativas/metabolismo
18.
Adv Exp Med Biol ; 1194: 225-238, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468538

RESUMO

The research on alternative computation paradigms has been initiated mainly because of the apparent limits induced by the nature of the materials and the methods used in current computing technologies. Due to the above observation, various bio-inspired computing methods have already been proposed and studied, both in practice and theory. In this paper, a review of such models is outlined with emphasis on biomolecular forms of computing. In addition, a novel biomolecular model of computation based on P systems is proposed inspired by the structure of mitochondria, namely, the mitochondria P systems and automata.


Assuntos
Biologia Computacional , Computadores , Modelos Moleculares , Biologia Computacional/instrumentação , Biologia Computacional/métodos , Biologia Computacional/tendências , Humanos , Mitocôndrias/fisiologia
20.
J Surg Res ; 254: 125-134, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32438104

RESUMO

BACKGROUND: The aim of this study is to investigate the protective effect of N-acetylcysteine (NAC) pretreatment on acute kidney injury in septic rats. METHODS: We constructed a septic rat model by cecal ligation and perforation (CLP) and assessed kidney tissue pathologic damage, renal function changes, and inflammatory factor levels. Meanwhile, we also assessed oxide and antioxidant enzyme levels in kidney tissues, observed apoptosis of kidney tissues, and evaluated mitochondrial membrane activity in renal cortical cells. RESULTS: Pretreatment of NAC significantly alleviated pathologic damage of kidney tissues in septic rats; decreased the levels of serum creatinine, blood urea nitrogen, plasma neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1; and reduced the expression of tumor necrosis factor a, interleukin [IL]-1ß, IL-6, and IL-8. Furthermore, NAC pretreatment reduced the level of protein-nitrotyrosine adducts and malondialdehyde in CLP-induced kidney tissues, while elevated the levels of superoxide dismutase, glutathione peroxidase, and catalase. Moreover, pretreatment of NAC reduced the number of apoptosis in kidney tissues induced by CLP, decreased the mRNA levels of caspase-3, caspase-9, cytochrome c, and poly ADP-ribose polymerase, and increased mitochondrial membrane activity in renal cortical cells (complex I/II/III/IV). CONCLUSIONS: NAC pretreatment has protective effects on acute kidney injury induced by CLP, and its mechanism is closely related to anti-inflammatory, antioxidation, antiapoptosis, and regulation of mitochondrial function.


Assuntos
Acetilcisteína/administração & dosagem , Lesão Renal Aguda/prevenção & controle , Sepse/complicações , Lesão Renal Aguda/etiologia , Lesão Renal Aguda/patologia , Animais , Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Apoptose , Ceco/cirurgia , Modelos Animais de Doenças , Rim/enzimologia , Rim/patologia , Ligadura , Masculino , Mitocôndrias/fisiologia , Ratos , Ratos Sprague-Dawley
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