A peroxiredoxin-P38 MAPK scaffold increases MAPK activity by MAP3K-independent mechanisms

Dietary polyphenols regulate appetite mechanism via gut-brain axis and gut homeostasis

Nowadays, due to the rise of fast-food consumption, the metabolic diseases are increasing as a result of high-sugar and high-fat diets. Therefore, there is an urgent need for natural, healthy and side-effect-free diets in daily life. Whole grain supplementation can enhance satiety and regulate energy metabolism, effects that have been attributed to polyphenol content. Dietary polyphenols interact with gut microbiota to produce intermediate metabolites that can regulate appetite while also enhancing prebiotic effects. This review considers how interactions between gut metabolites and dietary polyphenols might regulate appetite by acting on the gut-brain axis. In addition, further advances in the study of dietary polyphenols and gut microbial metabolites on energy metabolism and gut homeostasis are summarized. This review contributes to a better understanding of how dietary polyphenols regulate appetite via the gut-brain axis, thereby providing nutritional references for citizens' dietary preferences.

Computational models as catalysts for investigating redoxin systems

Thioredoxin, glutaredoxin and peroxiredoxin systems play central roles in redox regulation, signaling and metabolism in cells. In these systems, reducing equivalents from NAD(P)H are transferred by coupled thiol-disulfide exchange reactions to redoxins which then reduce a wide array of targets. However, the characterization of redoxin activity has been unclear, with redoxins regarded as enzymes in some studies and redox metabolites in others. Consequently, redoxin activities have been quantified by enzyme kinetic parameters in vitro, and redox potentials or redox ratios within cells. By analyzing all the reactions within these systems, computational models showed that many kinetic properties attributed to redoxins were due to system-level effects. Models of cellular redoxin networks have also been used to estimate intracellular hydrogen peroxide levels, analyze redox signaling and couple omic and kinetic data to understand the regulation of these networks in disease. Computational modeling has emerged as a powerful complementary tool to traditional redoxin enzyme kinetic and cellular assays that integrates data from a number of sources into a single quantitative framework to accelerate the analysis of redoxin systems.

Mechanisms underlying sensing of cellular stress signals by mammalian MAP3 kinases

Cellular homeostasis is continuously challenged by environmental cues and cellular stress conditions. In their defense, cells need to mount appropriate stress responses that, dependent on the cellular context, signaling intensity, and duration, may have diverse outcomes. The stress- and mitogen-activated protein kinase (SAPK/MAPK) system consists of well-characterized signaling cascades that sense and transduce an array of different stress stimuli into biological responses. However, the physical and chemical nature of stress signals and how these are sensed by individual upstream MAP kinase kinase kinases (MAP3Ks) remain largely ambiguous. Here, we review the existing knowledge of how individual members of the large and diverse group of MAP3Ks sense specific stress signals through largely non-redundant mechanisms. We emphasize the large knowledge gaps in assigning function and stress signals for individual MAP3K family members and touch on the potential of targeting this class of proteins for clinical benefit.

From workout to molecular switches: How does skeletal muscle produce, sense, and transduce subcellular redox signals?

Skeletal muscle is crucial for maintaining human health and overall quality of life. Acute exercise introduces a multifaceted intracellular stress, with numerous post-translational modifications believed to underpin the health benefits of sustained exercise training. Reactive oxygen species (ROS) are posited to serve as second messengers, triggering cytoprotective adaptations such as the upregulation of enzymatic scavenger systems. However, a significant knowledge gap exists between the generation of oxidants in muscle and the exact mechanisms driving muscle adaptations. This review delves into the current research on subcellular redox biochemistry and its role in the physiological adaptations to exercise. We propose that the subcellular regulation of specific redox modifications is key to ensuring specificity in the intracellular response.