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Plant Physiology and Biochemistry : PPB Sep 2023Under conditions of abiotic stress several physiological and biochemical processes in plants can be modified. The production of reactive oxygen species (ROS) is toxic at... (Review)
Review
Under conditions of abiotic stress several physiological and biochemical processes in plants can be modified. The production of reactive oxygen species (ROS) is toxic at high concentrations and promotes RNA, DNA and plant cell membrane degradation. Plants have enzymatic and non-enzymatic adaptation mechanisms to act against ROS detoxification. Ascorbic acid (AsA) is the non-enzymatic compound essential for several biological functions, which acts in the elimination and balance of ROS production and with the potential to promote several physiological functions in plants, such as the photosynthetic process. For plant development, AsA plays an important role in cell division, osmotic adjustment, hormone biosynthesis, and as an enzymatic cofactor. In this review, the redox reactions, biosynthetic pathways, and the physiological and biochemical functions of AsA against abiotic stress in plants are discussed. The concentration of AsA in plants can vary between species and depend on the biosynthetic pathways d-mannose/l-galactose, d-galacturonate, euglenids, and d-glucuronate. Although the endogenous levels of AsA in plants are used in large amounts in cell metabolism, the exogenous application of AsA further increases these endogenous levels to promote the antioxidant system and ameliorate the effects produced by abiotic stress. Foliar application of AsA promotes antioxidant metabolism in plants subjected to climate change conditions, also allowing the production of foods with higher nutritional quality and food safety, given the fact that AsA is biologically essential in the human diet.
Topics: Humans; Ascorbic Acid; Antioxidants; Reactive Oxygen Species; Acclimatization; Cell Division
PubMed: 37625254
DOI: 10.1016/j.plaphy.2023.107970 -
ELife Aug 2023Adaptation of the functional proteome is essential to counter pathogens during infection, yet precisely timed degradation of these response proteins after pathogen...
Adaptation of the functional proteome is essential to counter pathogens during infection, yet precisely timed degradation of these response proteins after pathogen clearance is likewise key to preventing autoimmunity. Interferon regulatory factor 1 (IRF1) plays an essential role as a transcription factor in driving the expression of immune response genes during infection. The striking difference in functional output with other IRFs is that IRF1 also drives the expression of various cell cycle inhibiting factors, making it an important tumor suppressor. Thus, it is critical to regulate the abundance of IRF1 to achieve a 'Goldilocks' zone in which there is sufficient IRF1 to prevent tumorigenesis, yet not too much which could drive excessive immune activation. Using genetic screening, we identified the E3 ligase receptor speckle type BTB/POZ protein (SPOP) to mediate IRF1 proteasomal turnover in human and mouse cells. We identified S/T-rich degrons in IRF1 required for its SPOP MATH domain-dependent turnover. In the absence of SPOP, elevated IRF1 protein levels functionally increased IRF1-dependent cellular responses, underpinning the biological significance of SPOP in curtailing IRF1 protein abundance.
Topics: Humans; Animals; Mice; Interferon Regulatory Factor-1; Genes, Regulator; Gene Expression Regulation; Acclimatization; Immunologic Factors
PubMed: 37622993
DOI: 10.7554/eLife.89951 -
Journal of Applied Physiology... Jun 2024
Topics: Climate Change; Humans; Acclimatization; Hot Temperature; Animals
PubMed: 38836542
DOI: 10.1152/japplphysiol.00265.2024 -
Nature Sep 2023The critical temperature beyond which photosynthetic machinery in tropical trees begins to fail averages approximately 46.7 °C (T). However, it remains unclear...
The critical temperature beyond which photosynthetic machinery in tropical trees begins to fail averages approximately 46.7 °C (T). However, it remains unclear whether leaf temperatures experienced by tropical vegetation approach this threshold or soon will under climate change. Here we found that pantropical canopy temperatures independently triangulated from individual leaf thermocouples, pyrgeometers and remote sensing (ECOSTRESS) have midday peak temperatures of approximately 34 °C during dry periods, with a long high-temperature tail that can exceed 40 °C. Leaf thermocouple data from multiple sites across the tropics suggest that even within pixels of moderate temperatures, upper canopy leaves exceed T 0.01% of the time. Furthermore, upper canopy leaf warming experiments (+2, 3 and 4 °C in Brazil, Puerto Rico and Australia, respectively) increased leaf temperatures non-linearly, with peak leaf temperatures exceeding T 1.3% of the time (11% for more than 43.5 °C, and 0.3% for more than 49.9 °C). Using an empirical model incorporating these dynamics (validated with warming experiment data), we found that tropical forests can withstand up to a 3.9 ± 0.5 °C increase in air temperatures before a potential tipping point in metabolic function, but remaining uncertainty in the plasticity and range of T in tropical trees and the effect of leaf death on tree death could drastically change this prediction. The 4.0 °C estimate is within the 'worst-case scenario' (representative concentration pathway (RCP) 8.5) of climate change predictions for tropical forests and therefore it is still within our power to decide (for example, by not taking the RCP 6.0 or 8.5 route) the fate of these critical realms of carbon, water and biodiversity.
Topics: Acclimatization; Australia; Brazil; Extreme Heat; Forests; Global Warming; Photosynthesis; Puerto Rico; Sustainable Development; Trees; Tropical Climate; Plant Leaves; Uncertainty
PubMed: 37612501
DOI: 10.1038/s41586-023-06391-z -
Sports Medicine (Auckland, N.Z.) Apr 2024The (patho-)physiological responses to hypoxia are highly heterogeneous between individuals. In this review, we focused on the roles of sex differences, which emerge as... (Review)
Review
The (patho-)physiological responses to hypoxia are highly heterogeneous between individuals. In this review, we focused on the roles of sex differences, which emerge as important factors in the regulation of the body's reaction to hypoxia. Several aspects should be considered for future research on hypoxia-related sex differences, particularly altitude training and clinical applications of hypoxia, as these will affect the selection of the optimal dose regarding safety and efficiency. There are several implications, but there are no practical recommendations if/how women should behave differently from men to optimise the benefits or minimise the risks of these hypoxia-related practices. Here, we evaluate the scarce scientific evidence of distinct (patho)physiological responses and adaptations to high altitude/hypoxia, biomechanical/anatomical differences in uphill/downhill locomotion, which is highly relevant for exercising in mountainous environments, and potentially differential effects of altitude training in women. Based on these factors, we derive sex-specific recommendations for mountain sports and intermittent hypoxia conditioning: (1) Although higher vulnerabilities of women to acute mountain sickness have not been unambiguously shown, sex-dependent physiological reactions to hypoxia may contribute to an increased acute mountain sickness vulnerability in some women. Adequate acclimatisation, slow ascent speed and/or preventive medication (e.g. acetazolamide) are solutions. (2) Targeted training of the respiratory musculature could be a valuable preparation for altitude training in women. (3) Sex hormones influence hypoxia responses and hormonal-cycle and/or menstrual-cycle phases therefore may be factors in acclimatisation to altitude and efficiency of altitude training. As many of the recommendations or observations of the present work remain partly speculative, we join previous calls for further quality research on female athletes in sports to be extended to the field of altitude and hypoxia.
Topics: Humans; Hypoxia; Female; Altitude Sickness; Altitude; Acclimatization; Sex Factors; Mountaineering; Adaptation, Physiological; Physical Conditioning, Human; Male
PubMed: 38082199
DOI: 10.1007/s40279-023-01970-6 -
Frontiers in Endocrinology 2023The dual aquaporin (Aqp1ab1/Aqp1ab2)-mediated hydration of marine teleost eggs, which occurs during oocyte meiosis resumption (maturation), is considered a key...
The dual aquaporin (Aqp1ab1/Aqp1ab2)-mediated hydration of marine teleost eggs, which occurs during oocyte meiosis resumption (maturation), is considered a key adaptation underpinning their evolutionary success in the oceans. However, the endocrine signals controlling this mechanism are almost unknown. Here, we investigated whether the nonapeptides arginine vasopressin (Avp, formerly vasotocin) and oxytocin (Oxt, formerly isotocin) are involved in marine teleost oocyte hydration using the gilthead seabream () as a model. We show that concomitant with an increased systemic production of Avp and Oxt, the nonapeptides are also produced and accumulated locally in the ovarian follicles during oocyte maturation and hydration. Functional characterization of representative Avp and Oxt receptor subtypes indicates that Avpr1aa and Oxtrb, expressed in the postvitellogenic oocyte, activate phospholipase C and protein kinase C pathways, while Avpr2aa, which is highly expressed in the oocyte and in the follicular theca and granulosa cells, activates the cAMP-protein kinase A (PKA) cascade. Using and mutagenesis approaches, we determined that Avpr2aa plays a major role in the PKA-mediated phosphorylation of the aquaporin subdomains driving membrane insertion of Aqp1ab2 in the theca and granulosa cells, and of Aqp1ab1 and Aqp1ab2 in the distal and proximal regions of the oocyte microvilli, respectively. The data further indicate that luteinizing hormone, which surges during oocyte maturation, induces the synthesis of Avp in the granulosa cells progestin production and the nuclear progestin receptor. Collectively, our data suggest that both the neurohypophysial and paracrine vasopressinergic systems integrate to differentially regulate the trafficking of the Aqp1ab-type paralogs a common Avp-Avpr2aa-PKA pathway to avoid competitive occupancy of the same plasma membrane space and maximize water influx during oocyte hydration.
Topics: Female; Animals; Oocytes; Ovarian Follicle; Acclimatization; Aquaporins; Arginine Vasopressin; Cyclic AMP-Dependent Protein Kinases
PubMed: 37635977
DOI: 10.3389/fendo.2023.1222724 -
Cell Reports Methods Aug 2023We present a miniaturized immunofluorescence assay (mini-IFA) for measuring antibody response in patient blood samples. The method utilizes machine learning-guided image...
We present a miniaturized immunofluorescence assay (mini-IFA) for measuring antibody response in patient blood samples. The method utilizes machine learning-guided image analysis and enables simultaneous measurement of immunoglobulin M (IgM), IgA, and IgG responses against different viral antigens in an automated and high-throughput manner. The assay relies on antigens expressed through transfection, enabling use at a low biosafety level and fast adaptation to emerging pathogens. Using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the model pathogen, we demonstrate that this method allows differentiation between vaccine-induced and infection-induced antibody responses. Additionally, we established a dedicated web page for quantitative visualization of sample-specific results and their distribution, comparing them with controls and other samples. Our results provide a proof of concept for the approach, demonstrating fast and accurate measurement of antibody responses in a research setup with prospects for clinical diagnostics.
Topics: Humans; SARS-CoV-2; COVID-19; COVID-19 Testing; Acclimatization; Machine Learning
PubMed: 37671026
DOI: 10.1016/j.crmeth.2023.100565 -
Nature Communications Jul 2023The evolution of endothermy in vertebrates is a major research topic in recent decades that has been tackled by a myriad of research disciplines including paleontology,...
The evolution of endothermy in vertebrates is a major research topic in recent decades that has been tackled by a myriad of research disciplines including paleontology, anatomy, physiology, evolutionary and developmental biology. The ability of most mammals to maintain a relatively constant and high body temperature is considered a key adaptation, enabling them to successfully colonize new habitats and harsh environments. It has been proposed that in mammals the anterior nasal cavity, which houses the maxilloturbinal, plays a pivotal role in body temperature maintenance, via a bony system supporting an epithelium involved in heat and moisture conservation. The presence and the relative size of the maxilloturbinal has been proposed to reflect the endothermic conditions and basal metabolic rate in extinct vertebrates. We show that there is no evidence to relate the origin of endothermy and the development of some turbinal bones by using a comprehensive dataset of µCT-derived maxilloturbinals spanning most mammalian orders. Indeed, we demonstrate that neither corrected basal metabolic rate nor body temperature significantly correlate with the relative surface area of the maxilloturbinal. Instead, we identify important variations in the relative surface area, morpho-anatomy, and complexity of the maxilloturbinal across the mammalian phylogeny and species ecology.
Topics: Animals; Mammals; Acclimatization; Basal Metabolism; Body Temperature; Ecology
PubMed: 37479710
DOI: 10.1038/s41467-023-39994-1 -
Plant Physiology and Biochemistry : PPB Jun 2024Neurotransmitters are naturally found in many plants, but the molecular processes that govern their actions still need to be better understood. Acetylcholine,... (Review)
Review
Neurotransmitters are naturally found in many plants, but the molecular processes that govern their actions still need to be better understood. Acetylcholine, γ-Aminobutyric acid, histamine, melatonin, serotonin, and glutamate are the most common neurotransmitters in animals, and they all play a part in the development and information processing. It is worth noting that all these chemicals have been found in plants. Although much emphasis has been placed on understanding how neurotransmitters regulate mood and behaviour in humans, little is known about how they regulate plant growth and development. In this article, the information was reviewed and updated considering current thinking on neurotransmitter signaling in plants' metabolism, growth, development, salt tolerance, and the associated avenues for underlying research. The goal of this study is to advance neurotransmitter signaling research in plant biology, especially in the area of salt stress physiology.
Topics: Neurotransmitter Agents; Plant Physiological Phenomena; Plants; Salt Stress; Salt Tolerance; Signal Transduction
PubMed: 38696867
DOI: 10.1016/j.plaphy.2024.108601 -
Science Advances Aug 2023Salient cues, such as the rising sun or availability of food, entrain biological clocks for behavioral adaptation. The mechanisms underlying entrainment to food...
Salient cues, such as the rising sun or availability of food, entrain biological clocks for behavioral adaptation. The mechanisms underlying entrainment to food availability remain elusive. Using single-nucleus RNA sequencing during scheduled feeding, we identified a dorsomedial hypothalamus leptin receptor-expressing (DMH) neuron population that up-regulates circadian entrainment genes and exhibits calcium activity before an anticipated meal. Exogenous leptin, silencing, or chemogenetic stimulation of DMH neurons disrupts the development of molecular and behavioral food entrainment. Repetitive DMH neuron activation leads to the partitioning of a secondary bout of circadian locomotor activity that is in phase with the stimulation and dependent on an intact suprachiasmatic nucleus (SCN). Last, we found a DMH neuron subpopulation that projects to the SCN with the capacity to influence the phase of the circadian clock. This direct DMH-SCN connection is well situated to integrate the metabolic and circadian systems, facilitating mealtime anticipation.
Topics: Receptors, Leptin; Hypothalamus; Suprachiasmatic Nucleus; Acclimatization; Circadian Clocks
PubMed: 37624889
DOI: 10.1126/sciadv.adh9570