Physiological Mechanisms Research Articles

Response mechanism of water status and photosynthetic characteristics of Cotoneaster multiflorus under drought stress and rehydrated conditions

IntroductionPlant physiology response and adaptation to drought stress has become a hotspot in plant ecology and evolution. Cotoneaster multiflorus possesses high ecological, ornamental and economic benefits. It has large root system and tolerance to cold, drought and poor soil. Therefore, C. multiflorus is considered as one of the most important tree species for ecological restoration in arid and semi-arid areas. However, little is known about the physiological mechanisms, molecular mechanisms and drought strategies of how C. multiflorus responds to drought stress. Therefore, exploring the physiological response mechanisms, molecular mechanisms and adaptive strategies of C. multiflorus in response to drought is important for its growth in arid and semi-arid regions.MethodsWe investigated the response and coupling mechanisms of water status, photosynthetic properties and chloroplast fluorescence parameters in C. multiflorus in response to drought and rehydrated after drought, especially the importance of nocturnal sap flow and nocturnal water refilling to maintain its own water balance in response to drought stress. In addition, we studied the stress response of C. multiflorus transcriptome factors, and we also discussed drought adaptation strategies of C. multiflorus.ResultsC. multiflorus adapted to drought stress by a series of structural and physiological mechanisms, such as promoting closing stomata, increasing nocturnal sap flow. When rehydrated after undergoing severe drought stress, its physiological activities such as photosynthesis, water status, chlorophyll fluorescence parameters and other physiological activities have rapidly resumed. This showed C. multiflorus had strong tolerance to drought. In addition, water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus were highly coupled. Nocturnal sap flow and nocturnal water refilling were very important for C. multiflorus to maintain its own water balance in response to drought stress. Finally, C. multiflorus will strengthen the drought defense mechanism by gene regulation of various metabolisms, such as promoting stomatal closure, reducing transpiration water loss, and vigorously regulating water balance. C. multiflorus responded to drought stress by avoiding or reducing water deficit in plant organs and tissues. Therefore, the shrub C. multiflorus is a drought-tolerant plant.DiscussionWe explored the response mechanisms of water status, photosynthetic characteristics, and chloroplast fluorescence parameters of C. multiflorus in drought and rehydrated after drought stress, especially the response mechanisms of nocturnal sap flow and nocturnal water refilling in response to drought stress, and identified the physiological coupling mechanisms, molecular mechanisms and drought types of C. multiflorus in response to drought.

Exploring the therapeutic potential of GLP-1 receptor agonists in the management of obstructive sleep apnea: a comprehensive review.

Obstructive Sleep Apnea (OSA) is a prevalent sleep disorder marked by repeated episodes of partial or complete upper airway obstruction during sleep, which leads to intermittent hypoxia and fragmented sleep. These disruptions negatively impact cardiovascular health, metabolic function, and overall quality of life. Obesity is amajor modifiable risk factor for OSA, as it contributes toboth anatomical and physiological mechanisms that increase the likelihood of airway collapse during sleep. While continuous positive airway pressure (CPAP) therapy remains the gold standard for OSA treatment, its limitations- particularly issues with patient adherence- underscore the need for alternative oradjunct therapeutic options. One such option is the use ofglucagon-like peptide-1 receptor agonists (GLP-1 RAs), which are widely recognized for their ability to reduce body weight and improve metabolic health. Emerging evidence suggests that GLP-1 RAs may offer therapeutic benefits in managing OSA, particularly by addressing obesity, a key contributor to the condition. This narrative review seeks to explore the role of GLP-1 RAs in the treatment of OSA, evaluating their efficacy in reducing OSA severity and discussing their broader clinical implications for future research and practice.

Non-invasive brain stimulation in cognitive sciences and Alzheimer's disease

Over the last four decades, non-invasive brain stimulation techniques (NIBS) have significantly gained interest in the fields of cognitive sciences and dementia care, including neurorehabilitation, for its emerging potential in increasing the insights over brain functions and in boosting residual cognitive functions. In the present paper, basic physiological and technical mechanisms and different applications of NIBS were reviewed and discussed to highlight the importance of NIBS in multidisciplinary and translational approaches in clinical and research settings of cognitive sciences and neurodegenerative diseases, especially in Alzheimer's disease. Indeed, NIBS strategies may represent a promising opportunity to increase the potential of neuromodulation as efficacious interventions for individualized patients care.

Enhancing Student Understanding of Cardiovascular Disease Burden in Marginalized Communities in the Physiology Classroom.

Physiology education is at the core of biomedical science and medicine. Physiology unites multiple disciplines to explain the mechanisms whereby a risk factor is associated with disease. Race, ethnicity, sexual orientation, and gender identity are associated with risk of cardiovascular disease (CVD). Minority Stress Theory attempts to explain the association of identity variables in sex and gender minority (SGM) and Black, Indigenous, and People of Color (BIPOC) populations with CVD. However, instruction on how to effectively incorporate the ways that social determinants of health are linked to disease outcomes in marginalized populations, such as the SGM and BIPOC communities, is needed. We investigated the efficacy of teaching Minority Stress Theory concepts in a single lecture in an upper-level cardiovascular pathophysiology course (N=44 students). To test students' understanding of minority-related disease, we used both subjective and objective measures to evaluate student understanding before and after the lecture. Student self-assessment of understanding of health disparity physiological mechanisms and lifestyle and pharmacologic interventions to reduce health disparities in SGM communities increased post-intervention. We observed similar results of self-assessment of understanding of health disparity physiological mechanisms and appropriate lifestyle and pharmacologic interventions to reduce health disparities regarding the BIPOC community. Our findings suggest that integrating social determinants of health into pathophysiology courses may result in a more inclusive-minded scientific and medical workforce.

Plant Coping with Cold Stress: Molecular and Physiological Adaptive Mechanisms with Future Perspectives

Cold stress strongly hinders plant growth and development. However, the molecular and physiological adaptive mechanisms of cold stress tolerance in plants are not well understood. Plants adopt several morpho-physiological changes to withstand cold stress. Plants have evolved various strategies to cope with cold stress. These strategies included changes in cellular membranes and chloroplast structure, regulating cold signals related to phytohormones and plant growth regulators (ABA, JA, GA, IAA, SA, BR, ET, CTK, and MET), reactive oxygen species (ROS), protein kinases, and inorganic ions. This review summarizes the mechanisms of how plants respond to cold stress, covering four main signal transduction pathways, including the abscisic acid (ABA) signal transduction pathway, Ca2+ signal transduction pathway, ROS signal transduction pathway, and mitogen-activated protein kinase (MAPK/MPK) cascade pathway. Some transcription factors, such as AP2/ERF, MYB, WRKY, NAC, and bZIP, not only act as calmodulin-binding proteins during cold perception but can also play important roles in the downstream chilling-signaling pathway. This review also highlights the analysis of those transcription factors such as bHLH, especially bHLH-type transcription factors ICE, and discusses their functions as phytohormone-responsive elements binding proteins in the promoter region under cold stress. In addition, a theoretical framework outlining plant responses to cold stress tolerance has been proposed. This theory aims to guide future research directions and inform agricultural production practices, ultimately enhancing crop resilience to cold stress.

A population dynamics approach to understand the invasiveness of the seaweed Rugulopteryx okamurae (Ochrophyta, Dictyotales)

The success of invasive species can be measured by invasiveness, which depicts intrinsic characteristics that enable them to thrive in new environments. In invasive seaweeds, for example, the persistence of multiple overlapping cohorts throughout the year plays a key role in increasing plant cover and exerting unrelenting pressure on invaded areas. The marine brown macroalgae Rugulopteryx okamurae has recently established abundant populations in the Mediterranean Sea and Atlantic Ocean, negatively affecting both biodiversity and socioeconomic factors by unprecedently aggressive invasive behaviour. The objective of the study is to understand the invasiveness of R. okamurae through its popu lation dynamics. For this, a year-round study was conducted in a protected habitat of Posidonia oceanica in southern Spain, revealing that R. okamurae uses alternating mechanisms for population maintenance. It achieves high density of young individuals in late summer and autumn, peaking at 3285 individuals per square metre. In spring and early summer, the population shifts towards fewer – but larger – individuals, with densities dropping to 888 individuals per square metre and biomass reaching a peak of 170 g dry weight (DW) per square metre. Six overlapping cohorts were identified by Gaussian curves. They persisted throughout the year, but they were not related to environmental factors, which indicates adaptive physiological mechanisms that sustain dense monospecific populations. Additionally, the association between cohorts and different morphotypes suggests that R. okamurae phenotypic plasticity enables its persistence in introduced areas. These findings provide valuable insights into the biological traits underpinning its invasiveness in P. oceanica meadows, revealing temporal windows of invasiveness driven by different mechanisms. This knowledge is crucial for developing effective conservation and management strategies aimed at mitigating the impact of this invasive species.

Applications and Challenges of Oral Peptide Drug Delivery in Diabetes Treatment

Peptide drugs, an important class of biopharmaceuticals, have been studied and applied in the field of diabetes treatment for decades. In recent years, with a deeper understanding of the physiological mechanisms of diabetes, efforts by developers to improve therapeutic efficacy have increased. Although oral administration is the most common mode of drug delivery, many peptide drugs still need to be administered by injection due to their unique chemical structures and biological properties. The paper aims to summarize the research literature related to diabetes and analyze the major barriers to the development of oral peptide drugs, such as the stability and low bioavailability of peptides in the GI tract, as well as technological coping strategies to address these barriers, including novel delivery systems and formulation optimization. In addition, it assesses the current progress in the development of oral peptide drugs and their clinical applications, mainly with reference to relevant literature from 2015 onwards. The results indicate that although some oral peptide drugs have been approved, the possibility of their popularization is still relatively small in the short term. Thus, future research should focus on overcoming the technical challenges of oral drug delivery in order to enhance their clinical application potential and ultimately provide patients with more convenient and effective treatment options

Evaluation of In Vitro Production Capabilities of Indole Derivatives by Lactic Acid Bacteria

Lactic acid Bacteria (LAB) convert tryptophan to indole derivatives and induce protective IL-22 production in vivo. However, differences in metabolizing capabilities among LAB species have not been widely investigated. In the present study, we compared the capabilities of 186 LAB strains to produce four kinds of indole derivatives, including indole-3-carboxaldehyde (IAId), indole-3-lactic acid (ILA), indole-3-propanoic acid (IPA), and indole-3-acetic acid (IAA). These strains were isolated from fermented foods, dairy products, and the feces of healthy individuals, as well as from fish and shrimp from Shanxi and Jiangsu provinces. They represent 15 genera, including Bifidobacterium, Enterococcus, Lacticaseibacillus, Lactiplantibacillus, Lactobacillus, Lactococcus, Limosilactobacillus, Pediococcus, Streptococcus, Weissella, Latilactobacillus, Levilactobacillus, Ligilactobacillus, and Loigolactobacillus. The results indicate widespread IAId-producing capabilities in LAB strains, with positive rates of approximately 90% (106/117) and 100% (69/69) among strains from Shanxi and Jiangsu provinces, respectively. The concentrations of IAId ranged from 72.42 ng/mL to 423.14 ng/mL in all positive strains from Shanxi Province and from 169.39 ng/mL to 503.51 ng/mL in strains from Jiangsu Province. Intriguingly, we also observed specific ILA-producing capabilities in Lactiplantibacillus strains, with positive rates of 55.17% (16/29) and 80.95% (17/21) among strains isolated from Shanxi and Jiangsu provinces, respectively. The overall detection rates of ILA among all tested strains (including both Lactiplantibacillus and other genus strains) were 17.9% (21/117) and 26.1% (18/69). The concentrations of ILA in positive strains ranged from 12.22 ng/mL to 101.86 ng/mL and from 5.75 ng/mL to 62.96 ng/mL from Shanxi and Jiangsu provinces, respectively. IPA and IAA were not detected in any strains. Finally, these indole derivative-producing capabilities were not related to their geographical origins or isolation sources. The current study provides insights into the species- or genus-dependent capabilities for metabolizing indole derivatives. Defining the specific roles of LAB in indole derivative metabolism will uncover the exact physiological mechanisms and be helpful for functional strain screening.

The cold tolerance of the terrestrial slug, Ambigolimax valentianus.

Terrestrial molluscs living in temperate and polar environments must contend with cold winter temperatures. However, the physiological mechanisms underlying the survival of terrestrial molluscs in cold environments and the strategies employed by them are poorly understood. Here we investigated the cold tolerance of Ambigolimax valentianus, an invasive, terrestrial slug that has established populations in Japan, Canada, and Europe. To do this, we acclimated A. valentianus to different environmental conditions (differing day lengths and temperatures), then exposed them to sub-zero temperatures and measured overall survival. Then, we measured low molecular weight metabolites using 1H NMR to see if they play a role in their cold tolerance as they do in other invertebrate species. We found that A. valentianus is not strongly freeze tolerant but does become more cold-hardy after acclimation to shorter day lengths. We also found that no metabolites were strongly upregulated in response to winter conditions despite the change in cold hardiness, and instead saw evidence of metabolic suppression leading up to winter such as formate and L-glutamine being suppressed in winter conditions.

Intermittent Fasting: Weighing the Benefits and Drawbacks for Health and Longevity – A Comprehensive Literature Review

Introduction:Obesity rates have risen sharply in recent decades, with one in eight people worldwide living with obesity in 2022. This has driven interest in the search for effective and sustainable dietary strategies. Intermittent fasting (IF), which alternates periods of eating and fasting, has gained considerable attention as a tool for weight management and overall health improvement. Unlike traditional calorie-restricted diets, IF’s simplicity and flexibility make it more accessible, potentially increasing adherence and long-term sustainability. Purpose:This study reviews current knowledge on IF, evaluating its physiological mechanisms, health benefits, risks, and long-term implications. It focuses on weight management, glucose metabolism, cardiovascular health, cognitive function, circadian rhythm, and sports performance, while addressing challenges related to safety and sustainability. Materials and Methods:This study reviews existing literature, including clinical trials, meta-analyses, and observational studies. It compares IF protocols such as alternate-day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE), emphasizing physiological effects and practical implications. Conclusion:Intermittent fasting represents a promising dietary intervention with wide-ranging health benefits, from weight management to improved metabolic and cognitive health. However, challenges such as nutritional deficiencies, risks of hypoglycemia, and limited long-term data highlight the need for personalized approaches and further investigation. Future research should prioritize large-scale, long-term studies to refine fasting protocols and ensure safety and effectiveness across diverse populations. By addressing these gaps, IF could evolve into a sustainable, evidence-based strategy for improving global health outcomes.

Influence of Geometric Parameters on The Hemodynamic Characteristics of The Vertebral Artery.

The carotid and vertebral arteries are principal conduits for cerebral blood supply and are common sites for atherosclerotic plaque formation. To date, there has been extensive clinical and hemodynamic reporting on carotid arteries; however, studies focusing on the hemodynamic characteristics of the vertebral artery (VA) are notably scarce. This article presents a systematic analysis of the impact of VA diameter and the angle of divergence from the subclavian artery (SA) on hemodynamic properties, facilitated by the construction of an idealized VA geometric model. Research indicates that the increase in the diameter of the VA is associated with a corresponding increase in the complexity of the vortex structures at the bifurcation with the SA. When the VA diameter is constant, a 30° VA-SA angle yields better hemodynamic capacity than 45° and 60° angles, and the patterns of blood flow and helicity values are consistent across different angles. Elevated Oscillatory shear index (OSI) zones are mainly at the origin of the VA, with an elliptical low OSI region within. As the diameter increases, the high OSI region spreads downstream. Increasing the bifurcation angle decreases OSI values in and below the elliptical low OSI region. These findings are valuable for studying the physiological and pathological mechanisms of VA atherosclerosis.

Cold Hardiness and Physio-Biochemical Responses of Annual Branches in Five Early-Fruiting Walnut Varieties (Juglans regia L.) Under Simulated Low-Temperature Stress

As global climate change escalates, horticultural crops, especially walnuts, face increased vulnerability to frost damage. Cold hardiness—a crucial trait for survival—is influenced by complex physiological and biochemical mechanisms. This study assessed the cold hardiness of five walnut cultivars—‘Xinxin 2’, ‘Wen 81’, ‘Wen 185’, ‘Zha 343’, and ‘Xinzaofeng’—under simulated low-temperature stress, focusing on differences in freezing tolerance. One-year branches were gradually cooled to temperatures as low as −30 °C. Key physiological metrics, including electrolyte leakage (EL) and regrowth (RG) potential, along with biochemical metrics like antioxidant enzyme activities and osmoregulatory compounds, were used to evaluate cold hardiness. A comprehensive cold resistance indicator, derived using the subordination function method, highlighted cultivar resilience. Results showed significant variation in cold tolerance, with ‘Wen 185’ and ‘Wen 81’ exhibiting superior resilience, while ‘Xinxin 2’ was the most susceptible. Logistic regression analysis of relative electrolyte conductivity (REC) data estimated the semi-lethal temperature (LT50), identifying ‘Wen 81’ as the most cold-tolerant cultivar (LT50 = −21.73 °C). Antioxidant enzymes and osmoregulatory compounds were crucial for maintaining cellular stability and recovery after freezing. These findings offer practical insights for breeding cold-resistant cultivars and strategies to mitigate frost damage.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and sarcopenia: A cross-sectional study.

The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is a newly developed lipid parameter that's used to evaluate cardiovascular disease risk. However, its association with sarcopenia risk has not been explored before. Data on NHHR and sarcopenia were based on the secondary analysis of the years 2011-2018 of National Health and Nutrition Examination Survey (NHANES) dataset. NHHR was nature log-transformed (LnNHHR) to achieve a normal distribution. A multivariate logistic regression and a restricted cubic spline (RCS) model adjusted for associated factors were utilized to evaluate the correlation between NHHR and sarcopenia. Subgroup and sensitivity analyses were conducted to verify the robustness of the findings. The study cohort comprised 7069 participants, of whom 6497 (91.91%) were sarcopenia-free, and 572 (8.09%) exhibited sarcopenia. A significant increase in NHHR was observed in the sarcopenia group compared to the non-sarcopenic group (P<0.001). Multivariate logistic regression analysis revealed that sarcopenia was independently linked to NHHR [odds ratio (OR): 1.394, P=0.007]. A linear relationship was identified between NHHR and sarcopenia risk (Pnon-linear=0.108). Interaction analysis indicated that the relationship between NHHR and sarcopenia risk was not significantly modified by gender, sex, poverty income ratio, education, smoking status, or race. NHHR was significantly associated with an elevated risk of sarcopenia among U.S. adults. Further research is warranted to elucidate the underlying physiological mechanisms through which NHHR influences sarcopenia development.

Exploring Dietary Composition in an Invasive Apple Snail From Different Habitats Combining With Intestinal Microbiota and Metabolomics.

Pomacea canaliculata is recognized as a globally invasive aquatic species. Analyses of intestinal microbiota, dietary composition, and metabolism of invasive species can enhance our understanding of their feeding strategies and physiological adaptation strategies to the environment. Intestinal content samples were collected from P. canaliculata inhabiting three distinct environments including a pond, a river, and a ditch. These samples were subjected to 16S rRNA gene sequencing analysis and multiple metabarcoding analyses, including eukaryotic 18S rRNA, mitochondrial cytochrome c oxidase I (COI), and chloroplast rbcL genes. In addition, metabolomics analysis was conducted on the intestinal content samples to investigate metabolic change. The highest dietary diversity in P. canaliculata was observed in the ditch, and females exhibited a higher dietary diversity than males in the pond. The 18S rRNA gene has a high potential for identifying the dietary components of omnivorous species. The intestinal microbiota of P. canaliculata from different habitats displayed significant variations, attributed to differences in food resources and other environmental factors. Bacteria in the aquatic environment had minimal impact on the intestinal microbiota of P. canaliculata. Overall, P. canaliculata exhibited adaptive changes in physiological characteristics across different habitats, including alterations in diet, which, in turn, influence microbiota and metabolic pathways such as amino acid biosynthesis in the intestine. The present study investigated the physiological mechanisms that enable P. canaliculata to adapt to diverse habitats, considering various factors including diet, which is important for comprehending its invasive potential and the subsequent threats it poses to aquatic ecosystems.

Auditory Brainstem Response (ABR) Recording of Simultaneous Electric-Acoustic Stimulation between Round Window Membrane and Basal Part of Cochlear Bone in guinea Pigs.

Extracochlear electric-acoustic stimulation (EAS) between the round window membrane and the basal part of the cochlear bone exhibits distinct auditory brainstem response (ABR) characteristics. The use of EAS in individuals with residual hearing is becoming increasingly common in clinical settings. Ongoing research has explored the characteristics of EAS-induced responses in hearing cochleae. This study explored a novel extracochlear EAS approach using round window membrane-cochlear bone stimulation to maintain cochlear integrity. The electrodes stimulate the basal part of the cochlea and spare the apex, making the model ideal for EAS candidates with profound high-frequency hearing loss and residual low-frequency hearing. ABR analyses of EAS were conducted to compare responses to acoustic, electrical, and combined stimulations. The threshold of EAS was higher than that of acoustic stimulation (AS) or electric stimulation (ES). The maximum peak height of the amplitude (MPHA) in the EAS showed sound pressure level (SPL)- and electric current-dependent changes, with superior performance at higher SPLs. The MPHA latency shift index analysis demonstrated significant differences between the EAS and the AS or ES only. In the context of EAS, neural responses occurring before 4 ms are defined as early responses, which are related to the stimulus. Late responses, occurring after 4 ms, suggest distinct physiological mechanisms that may involve synaptic actions or specific interactions within the EAS. Extracochlear EAS provides insights into its physiological implications, proposes a method for clinical application, and offers a potential avenue for improving hearing preservation and performance.

Can guilt enhance sensitivity to other's suffering? An EEG investigation into moral emotions and pain empathy.

As a unique form of empathy, pain empathy often has a close relationship with society and morality. Research has revealed that moral emotions can influence pain empathy. The underlying physiological mechanism still needs to be further examined to understand how moral emotions affect pain empathy. This study employs EEG and Machine Learning techniques, using a painful image induction paradigm to explore the impact of moral emotion (guilt)-on pain empathy and its neural mechanisms. Participants without pain sensation were instructed to observe and evaluate pictures of an anonymous hand in painful or non-painful pictures under feelings of guilt or neutral emotion. Results found slower reaction times and higher pain ratings for painful pictures. Furthermore, guilt led to higher pain ratings. Under conditions of painful pictures, guilt-induced greater P3(350-450ms) amplitudes and higher α oscillations and enhanced the functional connectivity between the prefrontal cortex, the central frontal region, and the parieto-occipital lobe. K-nearest neighbor can effectively classify high and low-pain empathy under guilt emotion. The result showed that guilt promotes the brain's processing of painful picture, causing individuals to pay high attention and engage in deep cognitive processing. This study provides insights into enhancing empathy and fostering interpersonal relationships.

Mind in others' shoes: Neuroscientific protocol for external referent decision awareness (ERDA) in organizations.

This study investigates the neural and physiological mechanisms underlying External Referent Decision Awareness (ERDA) within organizational contexts, focusing on hierarchical roles (Head, Peer, Staff). Twenty-two professionals participated, and electroencephalographic (EEG frequency band: Delta, Theta, Alpha, Beta, Gamma) and autonomic indices (skin conductance and cardiovascular indices) were recorded, while personality traits and decision-making styles were assessed. Results revealed higher Delta and Theta activation in the left temporo-parietal junction (TPJ) during Peer-related decisions, reflecting increased social cognition and ambiguity regulation in those contexts. Gamma activity, associated with high-order cognitive processes, was prominent in the left frontal cortex across all roles, indicating complex decision evaluation. These findings underscore the complexity of low-frequency bands (Delta and Theta), involved in emotional regulation and social cognition, while high-frequency bands (Gamma) reflect cognitive integration and decision complexity. Furthermore, autonomic data showed higher Skin Conductance Levels (SCL) for Head decisions, suggesting greater emotional involvement.The findings revealed a significant negative correlation between avoidant decision-making styles and the neural and behavioral evaluations of leader decisions, suggesting reduced engagement of neurocognitive systems involved in reward processing and evaluative judgment in individuals with a tendency to avoid decision-making. Additionally, higher extraversion correlated with more favorable evaluations of decisions made by Staff, potentially indicating greater activation in neural circuits associated with social reward and group dynamics. In conclusion, these findings suggest that neural activity and personality traits interact to shape hierarchical decision-making awareness, highlighting the need for tailored leadership and decision-making strategies in organizations.

Pymetrozine induced remarkable hemato-biochemical modifications and genotoxicity in vital organs of bighead carp (Aristichthys nobilis)

Pymetrozine (a pyridine azomethine pesticide) is one of the most commonly and frequently used insecticides. Scanty information is available about the deleterious effects of Pymetrozine on fish especially bighead carp. Hence, the current study investigated chronic toxicological effects of pymetrozine in bighead carp. A total of 80 fish were reared and divided into four groups(A–D) each containing 20 fish. Pymetrozine was given to experimental fish of groups B, C, and D mixed in water at doses of 5, 10, and 15 mg/L respectively for 30 days. Group A remained as control group. On days 10, 20, and 30 of the experiment, blood and other visceral tissues were collected for analysis of genotoxic effects, erythrocytic morphological and nuclear changes, antioxidant enzymes, and oxidative stress profile. The results revealed significantly higher values of various nuclear abnormalities (erythrocyte with micronuclei, red blood cells with condensed and lobed nuclei) and morphological changes (pear shaped erythrocyte, spindle shaped erythrocytes and spherocyte) in erythrocytes of bighead carp. The investigations on status of antioxidant enzymes and oxidative stress indicated higher values of oxidative stress biomarkers and lower values of antioxidant enzymes in visceral organs (brain, liver, gills, and kidneys) of treated fish. The findings on genotoxic potential of pymetrozine revealed a considerably increased frequency of DNA damage in isolated cells of multiple tissues (brain, liver, gills, and kidneys) of experimental fish at higher doses. In conclusion, it may be suggested that pymetrozine induces toxic effects via disruption of physiological mechanisms of multiple visceral organs of bighead carp.

Calcium-sensing receptor- and ADAM10-mediated klotho shedding is regulated by tetraspanin 5.

Soluble, circulating Klotho (sKlotho) is essential for normal health and renal function. sKlotho is shed from the renal distal convoluted tubule (DCT), its primary source, via enzymatic cleavage. However, the physiologic mechanisms that control sKlotho production, trafficking, and shedding are not fully defined. We previously found that the G protein-coupled calcium-sensing receptor (CaSR) co-localizes with membrane-bound αKlotho and the disintegrin/metalloprotease ADAM10 in the DCT and controls sKlotho in response to CaSR ligands and pHo by activating ADAM10. Here, we advance understanding of this process by showing that tetraspanin 5 (Tspan5), a scaffolding and chaperone protein, contributes to the cell surface expression and specificity of a protein complex that includes Tspan5, ADAM10, Klotho, and CaSR. These results support a model of multiprotein complexes that confer signaling specificity beyond CaSR on G protein-coupled processes. Impact statement Systemic circulating sKlotho is a determinant for normal physiology. Studies of knockout animals established its role as an anti-aging protein. The regulatory mechanisms for Klotho production and secretion are largely unknown. We report that Tspan 5 contributes to CaSR- and ADAM10-dependent Klotho shedding from the kidney, its primary source.

Genomic and physiological mechanisms of high-altitude adaptation in Ethiopian highlanders: a comparative perspective

High-altitude adaptation is a remarkable example of natural selection, yet the genomic and physiological adaptation mechanisms of Ethiopian highlanders remain poorly understood compared to their Andean and Tibetan counterparts. Ethiopian populations, such as the Amhara and Oromo, exhibit unique adaptive strategies characterized by moderate hemoglobin levels and enhanced arterial oxygen saturation, indicating distinct mechanisms of coping with chronic hypoxia. This review synthesizes current genomic insights into Ethiopian high-altitude adaptation, identifying key candidate genes involved in hypoxia tolerance and examining the influence of genetic diversity and historical admixture on adaptive responses. Furthermore, the review highlights significant research gaps, particularly the underrepresentation of Ethiopian populations in global genomic studies, the lack of comprehensive genotype-phenotype analyses, and inconsistencies in research methodologies. Addressing these gaps is crucial for advancing our understanding of the genetic basis of human adaptation to extreme environments and for developing a more complete picture of human physiological resilience. This review offers a comparative perspective with Tibetan and Andean highlanders, emphasizing the need for expanding genomic representation and refining methodologies to uncover the genetic mechanisms underlying high-altitude adaptation in Ethiopian populations.