Succinate Dehydrogenase Supports Metabolic Repurposing of Mitochondria to Drive Inflammatory Macrophages

Recently, the group of McBride reported a stunning observation regarding peroxisome biogenesis: newly born peroxisomes are hybrids of mitochondrial and ER-derived pre-peroxisomes. What was stunning? Studies performed with the yeast Saccharomyces cerevisiae had convincingly shown that peroxisomes are ER-derived, without indications for mitochondrial involvement. However, the recent finding using fibroblasts dovetails nicely with a mechanism inferred to be driving the eukaryotic invention of peroxisomes: reduction of mitochondrial reactive oxygen species (ROS) generation associated with fatty acid (FA) oxidation. This not only explains the mitochondrial involvement, but also its apparent absence in yeast. The latest results allow a reconstruction of the evolution of the yeast's highly derived metabolism and its limitations as a model organism in this instance. As I review here, peroxisomes are eukaryotic inventions reflecting mutual host endosymbiont adaptations: this is predicted by symbiogenetic theory, which states that the defining eukaryotic characteristics evolved as a result of mutual adaptations of two merging prokaryotes.See also the video abstract here: https://youtu.be/ HtyKhQ3DSxg

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We are able to read this because of quantum and thermodynamic principles that via an inorganic proton gradient, possibly generated 4.2 billion years ago, gave rise to a system that has an awareness of time and space by using energy to integrate information. Life can be described as a dissipative system driven by an energy gradient that uses information to positively reinforce its self-sustaining structure, which in turn increases its non-linear decisional capacity. Key in the evolution of life has been stress coupled to natural selection, which usually meant an increased demand for energy. As hormesis describes the adaptive response to stress, we propose that hormesis embraces not only the evolution of life, but that of intelligence itself, as natural selection would favour systems that enhances its efficiency. A component of the hormetic response in eukaryotes is the mitochondrion, which itself relies on quantum effects such as tunnelling. This suggests that quantum effects control the stability of individual cells as well as long-lived cellular networks. Hormesis, which can be anti-inflammatory, is therefore key in maintaining the functional stability of complex systems, including the brain. In contrast, a lack of classical hormetic factors, such as physical activity, plant polyphenols, or calorie restriction, will lead to accelerated cognitive decline, which is associated with increased inflammation. However, there may be another previously unidentified factor that could also be considered hormetic, and that is thinking itself. Here we propose that the process of "thinking", and managing complex movement, induces "stress" in the neuronal system and is therefore in itself part of maintaining cognitive health and reserve throughout life. In effect, the right amount of thinking and information processing can beneficially induce adaptation, and this itself could be explainable by quantum thermodynamics.