Chaotic fluctuations in mitochondrial function under oxidative stress. Superoxide dismutatase (SOD2) concentrations of 0.013, 0.016,0.0164, 0.0216733 mM

These chaotic time series of mitochondrial dynamics under conditions of oxidative stress are analyzed in detail in Kembro et al. 2018. Mitochondrial chaotic dynamics: Redox-energetic behavior at the edge of stability. Mitochondrial model used was described in the project overview and in detail (Kembro et al. 2013. Biophys J 104(2):332-343; Kembro et al., 2014. Front Physiol 5:257).Fil: Kembro, Jackelyn Melissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Aon, Miguel Antonio. University Johns Hopkins; Estados UnidosFil: Cortassa, Sonia del Carmen. University Johns Hopkins; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lloyd, David. Cardiff University; Reino UnidoFil: Sollott, Steven. National Institute on Aging; Estados Unido

The Fundamental Organization of Cardiac Mitochondria as a Network of Coupled Oscillators

Mitochondria can behave as individual oscillators whose dynamics may obey collective, network properties. We have shown that cardiomyocytes exhibit high-amplitude, self-sustained, and synchronous oscillations of bioenergetic parameters when the mitochondrial network is stressed to a critical state. Computational studies suggested that additional low-amplitude, high-frequency oscillations were also possible. Herein, employing power spectral analysis, we show that the temporal behavior of mitochondrial membrane potential (ΔΨ(m)) in cardiomyocytes under physiological conditions is oscillatory and characterized by a broad frequency distribution that obeys a homogeneous power law (1/f(β)) with a spectral exponent, β = 1.74. Additionally, relative dispersional analysis shows that mitochondrial oscillatory dynamics exhibits long-term memory, characterized by an inverse power law that scales with a fractal dimension (D(f)) of 1.008, distinct from random behavior (D(f) = 1.5), over at least three orders of magnitude. Analysis of a computational model of the mitochondrial oscillator suggests that the mechanistic origin of the power law behavior is based on the inverse dependence of amplitude versus frequency of oscillation related to the balance between reactive oxygen species production and scavenging. The results demonstrate that cardiac mitochondria behave as a network of coupled oscillators under both physiological and pathophysiological conditions

Glutathione/thioredoxin systems modulate mitochondrial H2O2 emission: An experimental-computational study

none7openAon M.A.; Stanley B.A.; Sivakumaran V.; Kembro J.M.; O'Rourke B.; Paolocci N.; Cortassa S.Aon, M. A.; Stanley, B. A.; Sivakumaran, V.; Kembro, J. M.; O'Rourke, B.; Paolocci, N.; Cortassa, S

Prevalence and surgical approach of supravalvular pulmonary stenosis after jatene operation for transposition of great arteries

FUNDAMENTO: A transposição das grandes artérias é a cardiopatia congênita cianogênica mais freqüente no período neonatal, correspondendo a 7% de todas as cardiopatias congênitas. Dentre as operações para tratamento cirúrgico, a operação de Jatene, com correção arterial, é o tratamento escolhido. Durante a evolução pós-operatória tardia, alguns problemas foram observados, sendo o mais comum a ocorrência de estenose supravalvar na neopulmonar, independentemente do tipo da técnica cirúrgica utilizada. OBJETIVO: Estudar e analisar a prevalência da estenose, bem como descrever o tratamento cirúrgico e propor manobras técnicas para prevenir seu aparecimento. MÉTODOS: Dentre 553 pacientes operados, 409 tiveram alta hospitalar e 281 seguidos tardiamente; 59 (20,9%) apresentaram diferentes graus de estenose supravalvar pulmonar e 21 gradiente médio superior a 60 mmHg, necessitando tratamento cirúrgico. Dependendo da localização e da anatomia da estenose, o tratamento cirúrgico constou de aplicação de diferentes técnicas, como ampliação das áreas de estenose com remendos de pericárdio bovino, ressecção de áreas estenóticas e anastomose término-terminal, substituição de remendos retraídos e de tubos sintéticos. RESULTADOS: Houve boa evolução em 20 pacientes, com óbito em um dos casos. CONCLUSÃO: Conclui-se que a estenose supravalvar pulmonar pós-operação de Jatene para transposição das grandes artérias teve prevalência de 20,9%. Uma vez identificada e com indicação de tratamento, pode ser tratada cirurgicamente com baixa mortalidade, mediante diferentes técnicas cirúrgicas. Para prevenir a ocorrência de estenose, propõem-se ampla dissecção e liberação dos ramos pulmonares, anastomoses amplas, remendos amplos de pericárdio autólogo e cuidado na reconstrução da neoaorta, evitando compressão da neopulmonar.BACKGROUND: The Transposition of the Great Arteries is the most frequent congenital cyanogenic cardiopathy in the neonatal period, corresponding to 7% of all congenital cardiopathies. Among the operations for surgical treatment, the Jatene operation, with arterial correction, is the treatment of choice. During the late postoperative evolution, some problems were observed, with the most common being the occurrence of supravalvular stenosis at the neopulmonary, regardless of the type of surgical technique used. OBJECTIVE: To study and analyze the prevalence of stenosis, as well as describe the surgical treatment and propose technical maneuvers to prevent its onset. METHODS: Of the 553 patients that underwent surgery, 409 were discharged from the hospital and 281 had late follow-up; 59 (20.9%) presented different degrees of supravalvular pulmonary stenosis and 21 had a mean gradient > 60 mmHg, needing surgical treatment. Depending on the location and anatomy of the stenosis, the surgical treatment consisted of the use of different techniques, such as the enlargement of stenosis areas with bovine pericardium patches, resection of stenotic areas and termino-terminal anastomosis, replacement of retracted patches and synthetic tubes. RESULTS: Twenty patients presented good evolution and only one patient died. CONCLUSION: It can be concluded that the supravalvular pulmonary stenosis, post-Jatene operation for Transposition of Great Arteries, had a prevalence of 20.9%; once identified and with indication for treatment, it can be treated surgically with low mortality levels, through different surgical techniques; to prevent the occurrence of stenosis, ample dissection and release of the pulmonary branches, double anastomoses, large patches of autologous pericardium and careful reconstruction of the aorta are proposed, which prevents the compression of the neopulmonary

Elucidating the mechanisms by which disulfiram protects against obesity and metabolic syndrome

Abstract There is an unmet need and urgency to find safe and effective anti-obesity interventions. Our recent study in mice fed on obesogenic diet found that treatment with the alcohol aversive drug disulfiram reduced feeding efficiency and led to a decrease in body weight and an increase in energy expenditure. The intervention with disulfiram improved glucose tolerance and insulin sensitivity, and mitigated metabolic dysfunctions in various organs through poorly defined mechanisms. Here, integrated analysis of transcriptomic and proteomic data from mouse and rat livers unveiled comparable signatures in response to disulfiram, revealing pathways associated with lipid and energy metabolism, redox, and detoxification. In cell culture, disulfiram was found to be a potent activator of autophagy, the malfunctioning of which has negative consequences on metabolic regulation. Thus, repurposing disulfiram may represent a potent strategy to combat obesity