Neuronal PRDX-2-Mediated ROS Signaling Regulates Food Digestion via peripheral UPRmt Activation
0
Citation
45
Reference
10
Related Paper
Abstract:
All organisms depend on food digestion for survival, yet the brain-gut signaling mechanisms that regulate this process are not fully understood. Here, using an established C. elegans digestion model, we uncover a pathway in which neuronal ROS (free radicals) signal the intestine to suppress digestion. Genetic screening reveals that reducing genes responsible for maintaining ROS balance increases free radicals and decreases digestion. PRDX-2 knockout in olfactory neurons (AWC) elevates ROS and reduces digestive capacity, mediated by the neuropeptide NLP-1 and activation of the mitochondrial unfolded protein response (UPRmt) in the intestine. Additionally, over-expressing nlp-1 or ablating AWC neurons both trigger UPRmt and inhibit digestion. These findings reveal a brain-gut connection in which neuronal PRDX-2-mediated ROS signaling modulates food digestion, highlighting a critical role of free radicals in shutting down digestion to alleviate stress and reduce food consumption. Neuronal PRDX-2-mediated reactive oxygen species (ROS) signaling in C. elegans AWC neurons triggers intestinal mitochondrial stress response, halting digestion to reduce cellular stress. This discovery reveals a brain-gut pathway regulating food intake via ROS signaling.Keywords:
Digestion
Mitochondrial ROS
Mitochondrial ROS
Mitochondrial respiratory chain
Cite
Citations (7)
Objective High levels of reactive oxygen species (ROS) are intricately linked to obesity and associated pathologies, notably insulin resistance and type 2 diabetes. However, ROS are also thought to be important in intracellular signaling, which may paradoxically be required for insulin sensitivity. Many theories have been developed to explain this apparent paradox, which have broadened our understanding of these important small molecules. While many sites for intracellular ROS production have been described, mitochondrial generated ROS remain a major contributor in most cell types. Mitochondrial ROS generation is controlled by a number of factors described in this review. Moreover, these studies have established both a demand for novel sensitive approaches to measure ROS, as well as a need to standardize and review their suitability for different applications. Methods To properly assess levels of ROS and mitochondrial ROS in the development of obesity and its complications, a growing number of tools have been developed. This paper reviews many of the common methods for the investigation of ROS in mitochondria, cell, animal, and human models. Results Available approaches can be generally divided into those that measure ROS‐induced damage (e.g., DNA, lipid, and protein damage); those that measure antioxidant levels and redox ratios; and those that use novel biosensors and probes for a more direct measure of different forms of ROS (e.g., 2′,7′‐di‐chlorofluorescein (DCF), dihydroethidium (DHE) and its mitochondrial targeted form (MitoSOX), Amplex Red, roGFP, HyPer, mt‐cpYFP, ratiometric H 2 O 2 probes, and their derivatives). Moreover, this review provides caveats and strengths for the use of these techniques in different models. Conclusions Advances in these techniques will undoubtedly advance the understanding of ROS in obesity and may help resolve unanswered questions in the field.
Mitochondrial ROS
Cite
Citations (220)
Mitochondrial ROS
Cite
Citations (280)
Mitochondrial ROS
Cite
Citations (1,289)
Mitochondrial ROS
Wild type
Cite
Citations (2)
Mitochondrial ROS
Hypoxia
Viability assay
Cite
Citations (136)
Oxidative stress is considered a major contributor to the etiology of both “normal” senescence and severe pathologies with serious public health implications. Several cellular sources, including mitochondria, are known to produce significant amounts of reactive oxygen species (ROS) that may contribute to intracellular oxidative stress. Mitochondria possess at least 10 known sites that are capable of generating ROS, but they also feature a sophisticated multilayered ROS defense system that is much less studied. This review summarizes the current knowledge about major components involved in mitochondrial ROS metabolism and factors that regulate ROS generation and removal at the level of mitochondria. An integrative systemic approach is applied to analysis of mitochondrial ROS metabolism, which is “dissected” into ROS generation, ROS emission, and ROS scavenging. The in vitro ROS‐producing capacity of several mitochondrial sites is compared in the metabolic context and the role of mitochondria in ROS‐dependent intracellular signaling is discussed.
Mitochondrial ROS
Cite
Citations (778)
Rotenone
Mitochondrial ROS
Cardioprotection
Antimycin A
Cite
Citations (0)
Mitochondrial ROS
Knockout mouse
Cite
Citations (100)
The production of reactive oxygen species (ROS) from the inner mitochondrial membrane is one of many fundamental processes governing the balance between health and disease. It is well known that ROS are necessary signaling molecules in gene expression, yet when expressed at high levels, ROS may cause oxidative stress and cell damage. Both hypoxia and hyperoxia may alter ROS production by changing mitochondrial Po2 (). Because depends on the balance between O2 transport and utilization, we formulated an integrative mathematical model of O2 transport and utilization in skeletal muscle to predict conditions to cause abnormally high ROS generation. Simulations using data from healthy subjects during maximal exercise at sea level reveal little mitochondrial ROS production. However, altitude triggers high mitochondrial ROS production in muscle regions with high metabolic capacity but limited O2 delivery. This altitude roughly coincides with the highest location of permanent human habitation. Above 25,000 ft., more than 90% of exercising muscle is predicted to produce abnormally high levels of ROS, corresponding to the "death zone" in mountaineering.
Mitochondrial ROS
Hyperoxia
Hypoxia
Cite
Citations (15)