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Earth's biodiversity is increasingly threatened and at risk. We propose a passive lunar biorepository for long-term storage of prioritized taxa of live cryopreserved samples to safeguard Earth's biodiversity and to support future space exploration and planet terraforming. Our initial focus will be on cryopreserving animal skin samples with fibroblast cells. An exemplar system has been developed using cryopreserved fish fins from the Starry Goby, Asterropteryx semipunctata. Samples will be expanded into fibroblast cells, recryopreserved, and then tested in an Earth-based laboratory for robust packaging and sensitivity to radiation. Two key factors for this biorepository are the needs to reduce damage from radiation and to maintain the samples near –196° Celsius. Certain lunar sites near the poles may meet these criteria. If possible, further testing would occur on the International Space Station prior to storage on the Moon. To secure a positive shared future, this is an open call to participate in this decades-long program. [ABSTRACT FROM AUTHOR]

Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) are excellent models for studying acute brain ischemia because they show high resistance to reductions in blood flow and oxygen delivery without evidence of neurological damage. In this study, we analyzed the insulin signaling pathway and regulation of mitochondrial substrate oxidation in three regions of ground squirrel brain (forebrain, cerebellum, and brainstem), comparing summer, late torpor, and interbout arousal conditions. We found select decreases in phospho-Akt in the cerebellum during torpor compared with summer animals, as well as select increases in the forebrain during interbout arousal, suggesting that Akt may influence either metabolism or cytoprotective pathways. The phosphoprotein abundance of glycogen synthase kinase 3 beta (GSK3[beta]) showed the most consistent trend across all three brain regions, with peak increases observed during deep torpor, suggesting a crucial role for this protein during hibernation. Furthermore, all three regions of the brain showed increased phospho-protein abundance of pyruvate dehydrogenase at serine 232 during both deep torpor and interbout arousal, and serine 300 during interbout arousal only, whereas other phosphorylation sites showed a region-specific expression pattern. Information collected from these studies sheds light on the molecular controls governing insulin signaling and fuel utilization in the brain of hibernating ground squirrels. Key words: hibernation, insulin signaling, protein translation, fat metabolism, glycolysis. Le spermophile rayé (Ictidomys tridecemlineatus) constitue un excellent modèle pour étudier l'ischémie cérébrale aigüe, car il est très résistant à des réductions du flux sanguin et de l'oxygénation sans manifestations d'un dommage neurologique. Dans cette étude, les auteurs ont analysé la voie de signalisation de l'insuline et la régulation de l'oxydation des substrats mitochondriaux dans trois régions du cerveau du spermophile (cerveau antérieur, cervelet et tronc cérébral) en comparant les conditions d'été, de torpeur tardive et d'éveil périodique. Ils ont trouvé des diminutions sélectives de phospho-Akt dans le cervelet durant la période de torpeur comparativement à l'été, de même que des augmentations sélectives dans le cerveau antérieur durant l'éveil périodique, suggérant que Akt puisse influencer le métabolisme ou les voies de protection cellulaire. À travers l'abondance de la forme phosphorylée de GSK3[beta] se dessinait la tendance la plus persistante à travers les trois régions du cerveau, avec des augmentations de pointe durant la torpeur profonde, suggérant que cette protéine jouerait un rôle important durant l'hibernation. En outre, l'abondance de la forme phosphorylée de la pyruvate déshydrogénase sur la sérine 232 était accrue dans les trois régions du cerveau durant la torpeur profonde et l'éveil périodique, la phosphorylation sur la sérine 300 était accrue durant l'éveil périodique seulement, alors que les sites de phosphorylation montraient un patron d'expression spécifique à la région. L'information recueillie lors de ces études fait la lumière sur les mécanismes de contrôle moléculaires qui gouvernent la signalisation et l'utilisation de carburant dans le cerveau des spermophiles en hibernation. [Traduit par la Rédaction] Mots-clés: hibernation, signalisation de l'insuline, traduction des protéines, métabolisme des lipides, glycolyse., Introduction Seasonal hibernation is a survival strategy used by a wide variety of mammals to survive extreme environmental changes in temperature and (or) food and water availability. Under unfavorable environmental [...]

Striated muscle shows an amazing ability to adapt its structural apparatus based on contractile activity, loading conditions, fuel supply, or environmental factors. Studies with mammalian hibernators have identified a variety of molecular pathways which are strategically regulated and allow animals to endure multiple stresses associated with the hibernating season. Of particular interest is the observation that hibernators show little skeletal muscle atrophy despite the profound metabolic rate depression and mechanical unloading that they experience during long weeks of torpor. Additionally, the cardiac muscle of hibernators must adjust to low temperature and reduced perfusion, while the strength of contraction increases in order to pump cold, viscous blood. Consequently, hibernators hold a wealth of knowledge as it pertains to understanding the natural capacity of myocytes to alter structural, contractile and metabolic properties in response to environmental stimuli. The present review outlines the molecular and biochemical mechanisms which play a role in muscular atrophy, hypertrophy, and remodeling. In this capacity, four main networks are highlighted: (1) antioxidant defenses, (2) the regulation of structural, contractile and metabolic proteins, (3) ubiquitin proteosomal machinery, and (4) macroautophagy pathways. Subsequently, we discuss the role of transcription factors nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Myocyte enhancer factor 2 (MEF2), and Forkhead box (FOXO) and their associated posttranslational modifications as it pertains to regulating each of these networks. Finally, we propose that comparing and contrasting these concepts to data collected from model organisms able to withstand dramatic changes in muscular function without injury will allow researchers to delineate physiological versus pathological responses.

Estivation is an adaptive stress response utilized by some amphibians during periods of drought in the summer season. In this study, we examine the regulation of the insulin signaling cascade and glycolysis pathway in the African clawed frog Xenopus laevis during the dehydration stress induced state of estivation. We show that in the brain and heart of X. laevis, dehydration reduces the phosphorylation of the insulin growth factor-1 receptor (IGF-1R), and this is followed by similar reductions in the phosphorylation of the Akt and mechanistic target of rapamycin (mTOR) kinase. Interestingly, phosphorylation levels of IGF-1R and mTOR were not affected in the kidney, and phosphorylation levels of P70S6K and the ribosomal S6 protein were elevated during dehydration stress. Animals under estivation are also susceptible to periods of hypoxia, suggesting that glycolysis may also be affected. We observed that protein levels of many glycolytic enzymes remained unchanged during dehydration; however, the hypoxia response factor-1 alpha (HIF-1[alpha]) protein was elevated by greater than twofold in the heart during dehydration. Overall, we provide evidence that shows that the insulin signaling pathway in X. laevis is regulated in a tissue-specific manner during dehydration stress and suggests an important role for this signaling cascade in mediating the estivation response. Key words: desiccation, metabolic depression, mTOR, HIF-1, estivation. Resume: L'estivation est une reponse adaptative au stress utilisee par certains amphibiens durant les periodes de secheresse de la saison estivale. Dans cette etude, les auteurs ont examine la regulation de la cascade de signalisation de l'insuline et de la voie de la glycolyse chez le xenope, Xenopus laevis, pendant un etat d'estivation induit par le stress de la deshydratation. Ils montrent que dans le cerveau et le cceur de X. laevis, la deshydratation reduit la phosphorylation du recepteur du facteur de croissance insulinomimetique-1 (IGF-1R) et que cette reduction est suivie par des reductions similaires de la phosphorylation des kinases Akt et mTOR (<< mechanistic target of rapamycin >>). Fait interessant, les niveaux de phosphorylation de IGF-1R et de mTOR n'etaient pas affectes dans le rein, et les niveaux de phosphorylation de P70S6K et de la proteine ribosomique S6 etaient accrus durant le stress de la deshydratation. Les animaux en estivation sont aussi susceptibles a des periodes d'hypoxie, suggerant que la glycolyse peut etre aussi affectee. Les auteurs ont observe que les niveaux proteiques de plusieurs enzymes de la glycolyse demeuraient inchanges durant la deshydratation, mais que le facteur de reponse a l'hypoxie-1 alpha (HIF-1a) etait de plus de deux fois plus eleve dans le cceur durant la deshydratation. Globalement, les auteurs apportent des elements qui montrent que la voie de signalisation de l'insuline chez X. laevis est regulee de maniere specifique au tissu durant le stress de la deshydratation, et suggerent que cette cascade de signalisation joue un role important dans la mediation de l'estivation. [Traduit par la Redaction] Mots-cles: dessiccation, depression metabolique, mTOR, HIF-1, estivation., Introduction The African clawed frog Xenopus laevis is commonly used as a model organism to study vertebrate developmental biology and embryology; Xenopus frogs are an attractive research model, as the [...]

Background For 50 years, static cold storage (SCS) has been the gold standard for solid organ preservation in transplantation. Although logistically convenient, this preservation method presents important constraints in terms of duration and cold ischemia-induced lesions. We aimed to develop a machine perfusion (MP) protocol for recovery of vascularized composite allografts (VCA) after static cold preservation and determine its effects in a rat limb transplantation model. Methods Partial hindlimbs were procured from Lewis rats and subjected to SCS in Histidine-Tryptophan-Ketoglutarate solution for 0, 12, 18, 24, and 48 hours. They were then either transplanted (Txp), subjected to subnormothermic machine perfusion (SNMP) for 3 hours with a modified Steen solution, or to SNMP + Txp. Perfusion parameters were assessed for blood gas and electrolytes measurement, and flow rate and arterial pressures were monitored continuously. Histology was assessed at the end of perfusion. For select SCS durations, graft survival and clinical outcomes after transplantation were compared between groups at 21 days. Results Transplantation of limbs preserved for 0, 12, 18, and 24-hour SCS resulted in similar survival rates at postoperative day 21. Grafts cold-stored for 48 hours presented delayed graft failure (p = 0.0032). SNMP of limbs after 12-hour SCS recovered the vascular resistance, potassium, and lactate levels to values similar to limbs that were not subjected to SCS. However, 18-hour SCS grafts developed significant edema during SNMP recovery. Transplantation of grafts that had undergone a mixed preservation method (12-hour SCS + SNMP + Txp) resulted in better clinical outcomes based on skin clinical scores at day 21 post-transplantation when compared to the SCS + Txp group (p = 0.01613). Conclusion To date, VCA MP is still limited to animal models and no protocols are yet developed for graft recovery. Our study suggests that ex vivo SNMP could help increase the preservation duration and limit cold ischemia-induced injury in VCA transplantation. [ABSTRACT FROM AUTHOR]