-
International Journal of Molecular... Jan 2023High-altitude illnesses (HAIs) result from acute exposure to high altitude/hypoxia. Numerous molecular mechanisms affect appropriate acclimatization to hypobaric and/or... (Review)
Review
High-altitude illnesses (HAIs) result from acute exposure to high altitude/hypoxia. Numerous molecular mechanisms affect appropriate acclimatization to hypobaric and/or normobaric hypoxia and curtail the development of HAIs. The understanding of these mechanisms is essential to optimize hypoxic acclimatization for efficient prophylaxis and treatment of HAIs. This review aims to link outcomes of molecular mechanisms to either adverse effects of acute high-altitude/hypoxia exposure or the developing tolerance with acclimatization. After summarizing systemic physiological responses to acute high-altitude exposure, the associated acclimatization, and the epidemiology and pathophysiology of various HAIs, the article focuses on molecular adjustments and maladjustments during acute exposure and acclimatization to high altitude/hypoxia. Pivotal modifying mechanisms include molecular responses orchestrated by transcription factors, most notably hypoxia inducible factors, and reciprocal effects on mitochondrial functions and REDOX homeostasis. In addition, discussed are genetic factors and the resultant proteomic profiles determining these hypoxia-modifying mechanisms culminating in successful high-altitude acclimatization. Lastly, the article discusses practical considerations related to the molecular aspects of acclimatization and altitude training strategies.
Topics: Humans; Altitude; Proteomics; Altitude Sickness; Hypoxia; Acclimatization
PubMed: 36675214
DOI: 10.3390/ijms24021698 -
Nature Nov 2019The current trajectory for crop yields is insufficient to nourish the world's population by 2050. Greater and more consistent crop production must be achieved against a... (Review)
Review
The current trajectory for crop yields is insufficient to nourish the world's population by 2050. Greater and more consistent crop production must be achieved against a backdrop of climatic stress that limits yields, owing to shifts in pests and pathogens, precipitation, heat-waves and other weather extremes. Here we consider the potential of plant sciences to address post-Green Revolution challenges in agriculture and explore emerging strategies for enhancing sustainable crop production and resilience in a changing climate. Accelerated crop improvement must leverage naturally evolved traits and transformative engineering driven by mechanistic understanding, to yield the resilient production systems that are needed to ensure future harvests.
Topics: Acclimatization; Animals; Crop Production; Crops, Agricultural; Fertilizers; Food Supply; Global Warming; Humans; Plant Diseases; Rain; Sustainable Development
PubMed: 31695205
DOI: 10.1038/s41586-019-1679-0 -
The Plant Cell Nov 2021Light and temperature are two key environmental factors that coordinately regulate plant growth and development. Although the mechanisms that integrate signaling...
Light and temperature are two key environmental factors that coordinately regulate plant growth and development. Although the mechanisms that integrate signaling mediated by cold and red light have been unraveled, the roles of the blue light photoreceptors cryptochromes in plant responses to cold remain unclear. In this study, we demonstrate that the CRYPTOCHROME2 (CRY2)-COP1-HY5-BBX7/8 module regulates blue light-dependent cold acclimation in Arabidopsis thaliana. We show that phosphorylated forms of CRY2 induced by blue light are stabilized by cold stress and that cold-stabilized CRY2 competes with the transcription factor HY5 to attenuate the HY5-COP1 interaction, thereby allowing HY5 to accumulate at cold temperatures. Furthermore, our data demonstrate that B-BOX DOMAIN PROTEIN7 (BBX7) and BBX8 function as direct HY5 targets that positively regulate freezing tolerance by modulating the expression of a set of cold-responsive genes, which mainly occurs independently of the C-repeat-binding factor pathway. Our study uncovers a mechanistic framework by which CRY2-mediated blue-light signaling enhances freezing tolerance, shedding light on the molecular mechanisms underlying the crosstalk between cold and light signaling pathways in plants.
Topics: Acclimatization; Arabidopsis; Cold Temperature; Light; Light Signal Transduction
PubMed: 34427646
DOI: 10.1093/plcell/koab215 -
Journal of the International Society of... Jan 2020The ergogenic effects of supplemental carbohydrate on aerobic exercise performance at high altitude (HA) may be modulated by acclimatization status. Longitudinal... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The ergogenic effects of supplemental carbohydrate on aerobic exercise performance at high altitude (HA) may be modulated by acclimatization status. Longitudinal evaluation of potential performance benefits of carbohydrate supplementation in the same volunteers before and after acclimatization to HA have not been reported.
PURPOSE
This study examined how consuming carbohydrate affected 2-mile time trial performance in lowlanders at HA (4300 m) before and after acclimatization.
METHODS
Fourteen unacclimatized men performed 80 min of metabolically-matched (~ 1.7 L/min) treadmill walking at sea level (SL), after ~ 5 h of acute HA exposure, and after 22 days of HA acclimatization and concomitant 40% energy deficit (chronic HA). Before, and every 20 min during walking, participants consumed either carbohydrate (CHO, n = 8; 65.25 g fructose + 79.75 g glucose, 1.8 g carbohydrate/min) or flavor-matched placebo (PLA, n = 6) beverages. A self-paced 2-mile treadmill time trial was performed immediately after completing the 80-min walk.
RESULTS
There were no differences (P > 0.05) in time trial duration between CHO and PLA at SL, acute HA, or chronic HA. Time trial duration was longer (P < 0.05) at acute HA (mean ± SD; 27.3 ± 6.3 min) compared to chronic HA (23.6 ± 4.5 min) and SL (17.6 ± 3.6 min); however, time trial duration at chronic HA was still longer than SL (P < 0.05).
CONCLUSION
These data suggest that carbohydrate supplementation does not enhance aerobic exercise performance in lowlanders acutely exposed or acclimatized to HA.
TRIAL REGISTRATION
NCT, NCT02731066, Registered March 292,016.
Topics: Acclimatization; Altitude; Carbohydrates; Dietary Supplements; Exercise; Heart Rate; Humans; Longitudinal Studies; Male; Oxygen Consumption; Physical Exertion
PubMed: 31918720
DOI: 10.1186/s12970-020-0335-2 -
Philosophical Transactions of the Royal... May 2023The study of sex allocation-that is, the investment of resources into male versus female reproductive effort-yields among the best quantitative evidence for Darwinian... (Review)
Review
The study of sex allocation-that is, the investment of resources into male versus female reproductive effort-yields among the best quantitative evidence for Darwinian adaptation, and has long enjoyed a tight and productive interplay of theoretical and empirical research. The fitness consequences of an individual's sex allocation decisions depend crucially upon the sex allocation behaviour of others and, accordingly, sex allocation is readily conceptualized in terms of an evolutionary game. Here, I investigate the historical development of understanding of a fundamental driver of the evolution of sex allocation-the rarer-sex effect-from its inception in the writing of Charles Darwin in 1871 through to its explicit framing in terms of consanguinity and reproductive value by William D. Hamilton in 1972. I show that step-wise development of theory proceeded through refinements in the conceptualization of the strategy set, the payoff function and the unbeatable strategy. This article is part of the theme issue 'Half a century of evolutionary games: a synthesis of theory, application and future directions'.
Topics: Male; Female; Humans; Reproduction; Adaptation, Physiological; Acclimatization; Biological Evolution
PubMed: 36934750
DOI: 10.1098/rstb.2021.0500 -
Plant Communications Nov 2020
Topics: Acclimatization; Adaptation, Physiological; Biological Evolution; Plants
PubMed: 33367271
DOI: 10.1016/j.xplc.2020.100118 -
Current Biology : CB Feb 2021The term 'neural adaptation' refers to the common phenomenon of decaying neuronal activities in response to repeated or prolonged stimulation. Many different roles of...
The term 'neural adaptation' refers to the common phenomenon of decaying neuronal activities in response to repeated or prolonged stimulation. Many different roles of adaptation in neural computations have been discussed. On a single-cell level adaptation introduces a high-pass filter operation as a basic element for predictive coding. Interactions of adaptation processes with nonlinearities are key to many more computations including generation of invariances, stimulus selectivity, denoising, and sparsening. Neural adaptation is observed all the way along neuronal pathways from the sensory periphery to the motor output and adaptation usually gets stronger at higher levels. Non-adapting neurons or neurons that increase their sensitivity are rare exceptions. What computations arise by repeated adaptation mechanisms along a processing pathway? After giving some background on neural adaptation, underlying mechanisms, dynamics, and resulting filter properties, I will discuss computational properties of four examples of serial and parallel adaptation processes, demonstrating that adaptation acts together with other mechanisms, in particular threshold nonlinearities, to eventually compute meaningful perceptions. Python code and further details of the simulations illustrating this primer are available at https://github.com/janscience/adaptationprimer.
Topics: Acclimatization; Adaptation, Physiological; Neurons
PubMed: 33561404
DOI: 10.1016/j.cub.2020.11.054 -
Biology Letters Nov 2022According to several interlinked and influential lines of argument, human minds have been shaped by natural selection so as to include biological adaptations with the... (Review)
Review
According to several interlinked and influential lines of argument, human minds have been shaped by natural selection so as to include biological adaptations with the evolved, naturally selected function to facilitate the transmission of cultural knowledge. This 'cultural minds' hypothesis has proved highly influential, and if it is correct it is a major step forward in understanding how and why humans have survived and prospered in a hugely diverse range of ecologies. It can be contrasted with a 'social minds' hypothesis, according to which cultural transmission occurs as an outcome, but not the biologically evolved function, of social cognition the domain of which is relatively small-group interaction. Here, I critique the cultural minds hypothesis and I argue that the data favour the social minds perspective. Cultural phenomena can clearly emerge and persist over time without cognitive adaptations for cultural transmission. Overtly intentional communication plays an especially pivotal role.
Topics: Humans; Adaptation, Biological; Acclimatization; Communication; Ecology
PubMed: 36448292
DOI: 10.1098/rsbl.2022.0439 -
Nature Reviews. Nephrology Dec 2021Evolutionary processes, including mutation, migration and natural selection, have influenced the prevalence and distribution of various disorders in humans. However,... (Review)
Review
Evolutionary processes, including mutation, migration and natural selection, have influenced the prevalence and distribution of various disorders in humans. However, despite a few well-known examples, such as the APOL1 variants - which have undergone positive genetic selection for their ability to confer resistance to Trypanosoma brucei infection but confer a higher risk of chronic kidney disease - little is known about the effects of evolutionary processes that have shaped genetic variation on kidney disease. An understanding of basic concepts in evolutionary genetics provides an opportunity to consider how findings from ancient and archaic genomes could inform our knowledge of evolution and provide insights into how population migration and genetic admixture have shaped the current distribution and landscape of human kidney-associated diseases. Differences in exposures to infectious agents, environmental toxins, dietary components and climate also have the potential to influence the evolutionary genetics of kidneys. Of note, selective pressure on loci associated with kidney disease is often from non-kidney diseases, and thus it is important to understand how the link between genome-wide selected loci and kidney disease occurs in relation to secondary nephropathies.
Topics: Acclimatization; Apolipoprotein L1; Genetic Variation; Genome; Humans; Kidney Diseases; Mutation; Nephrology
PubMed: 34584272
DOI: 10.1038/s41581-021-00483-7 -
ELife May 2023A combination of imaging and theory suggests a new mechanism for the remodeling of veins in vascular networks.
A combination of imaging and theory suggests a new mechanism for the remodeling of veins in vascular networks.
Topics: Veins; Cardiovascular System; Adaptation, Physiological; Acclimatization
PubMed: 37227267
DOI: 10.7554/eLife.88052