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Wood frogs are a few vertebrate species that can survive whole-body freezing. Multiple adaptations support this, including cryoprotectant production (glucose), metabolic rate depression, and selective changes in gene and protein expression to activate pro-survival pathways. The role of DNA methylation machinery (DNA methyltransferases, DNMTs) in regulating nuclear gene expression to support freezing survival has already been established. However, a comparable role for DNMTs in the mitochondria has not been explored in wood frogs. We examined the mitochondrial protein levels of DNMT-1, DNMT-3A, DNMT-3B, and DNMT-3L as well as mitochondrial DNMT activity in the liver and heart to assess the involvement of DNMT in the survival of freezing and dehydration stresses (cellular dehydration being a component of freezing). Our results showed stress- and tissue-specific responses to mitochondrial DNMT-1 in the liver and heart, respectively. During 24 h of freezing and whole-body dehydration, we observed an overall downregulation of mitochondrial DNMT-1, a major protein involved in maintaining methylation levels related to its role in the selective transcription of mitochondrial genes as well as antioxidant response. Tissue-specific responses of protein levels of DNMT-3A, DNMT-3B, DNMT-3L, and DNMT activity in the liver suggested a preference for a higher methylation state in the liver under both freezing and dehydration stress, but not in the heart. Key words: DNMT activity, metabolic rate depression, antioxidant response, mitochondria, mitochondrial proteins. Les grenouilles des bois sont l'une des rares especes de vertebres qui peuvent survivre a la congelation du corps entier. De multiples adaptations permettent cette survie, notamment la production de cryoprotecteurs (glucose), la reduction de la vitesse du metabolisme et des changements selectifs dans l'expression de genes et de proteines pour activer les voies favorisant la survie. Le role de la machinerie de methylation de l'ADN (ADN methyltransferases, DNMT) dans la regulation de l'expression des genes nucleaires favorisant la survie lors de la congelation a deja ete etabli. Cependant, un role comparable des DNMT dans les mitochondries n'a pas ete explore chez les grenouilles des bois. Les auteurs ont examine les niveaux des proteines DNMT-1, DNMT-3A, DNMT-3B et DNMT-3L dans les mitochondries ainsi que l'activite DNMT mitochondriale dans le foie et le coeur afin d'evaluer l'implication des DNMT dans la survie aux deux types de stress provoques par le gel et la deshydratation (la deshydratation cellulaire etant une composante du gel). Leurs resultats ont montre une reponse par la proteine DNMT-1 mitochondriale specifique au stress et au tissu dans le foie et le coeur respectivement. Au cours d'une congelation de 24 heures et d'une deshydratation du corps entier, ils ont observe une regulation globale a la baisse de la DNMT-1 mitochondriale, une proteine majeure impliquee dans le maintien des niveaux de methylation, liee a son role dans la transcription selective des genes mitochondriaux ainsi que dans la reponse antioxydante. La reponse specifique au tissu des niveaux des proteines DNMT-3A, DNMT-3B et DNMT-3L et l'activite DNMT dans le foie ont suggere une preference pour un etat de methylation plus eleve dans le foie sous les deux types de stress de congelation et de deshydratation, mais pas dans le coeur. [Traduit par la Redaction] Mots-cles : Activite DNMT, reduction de la vitesse du metabolisme, reponse antioxydante, mitochondries, proteines mitochondriales., Introduction Wood frogs, Rana sylvatica, are one of the best-studied models of natural freeze-tolerance; they can survive whole-body freezing during winter, with up to 65%--70% of their total body water [...]

Diabetic neuropathy (DN) is a neurodegenerative disorder that is primarily characterized by distal sensory loss, reduced mobility, and foot ulcers that may potentially lead to amputation. The multifaceted etiology of DN is linked to a range of inflammatory, vascular, metabolic, and other neurodegenerative factors. Chronic inflammation, endothelial dysfunction, and oxidative stress are the three basic biological changes that contribute to the development of DN. Although our understanding of the intricacies of DN has advanced significantly over the past decade, the distinctive mechanisms underlying the condition are still poorly understood, which may be the reason behind the lack of an effective treatment and cure for DN. The present study delivers a comprehensive understanding and highlights the potential role of the several pathways and molecular mechanisms underlying the etiopathogenesis of DN. Moreover, Schwann cells and satellite glial cells, as integral factors in the pathogenesis of DN, have been enlightened. This work will motivate allied research disciplines to gain a better understanding and analysis of the current state of the biomolecular mechanisms behind the pathogenesis of DN, which will be essential to effectively address every facet of DN, from prevention to treatment. [ABSTRACT FROM AUTHOR]

The article discusses the coordination between India and Association of Southeast Asian Nations (ASEAN) regarding the Indo-Pacific, highlighting their shared principles and evolving strategic partnership. Topics include the development of Indo-Pacific policies, maritime cooperation, and regional security challenges in the context of ASEAN-India relations and collaboration amidst evolving regional dynamics and the emergence of the Indo-Pacific concept.