scholarly journals Changes to coral health and metabolic activity under oxygen deprivation

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1956 ◽  
Author(s):  
James W.A. Murphy ◽  
Robert H. Richmond
Keyword(s):  
Dehydrogenase Activity ◽  
Field Data ◽  
Anaerobic Respiration ◽  
Oxygen Deprivation ◽  
Tissue Loss ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Coral Health ◽  
The Impact ◽  
Octopine Dehydrogenase

On Hawaiian reefs, the fast-growing, invasive algaeGracilaria salicorniaovergrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health.

scholarly journals Changes to coral health and metabolic activity under oxygen deprivation

2016 ◽  
Author(s):  
James WA Murphy ◽  
Robert H Richmond
Keyword(s):  
Critical Role ◽  
Metabolic Stress ◽  
Oxygen Deprivation ◽  
Tissue Loss ◽  
Low Oxygen ◽  
Invasive Algae ◽  
Hypoxic Conditions ◽  
Coral Stress ◽  
Coral Health ◽  
Effect Of Oxygen

Scleractinian corals play a critical role in tropical marine ecosystems by providing essential structure and food for coral reef inhabitants. However, recent investigations have found an alarming increase in coral losses from a variety of stressors, which threatens the general health and resilience of tropical coastal ecosystems. The effect of oxygen deprivation on the health of Hawaiian corals based on local drivers is of particular concern. On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. This study evaluates changes in coral health and metabolism through the replication of hypoxic conditions in a laboratory setting in order to limit the contribution of additional environmental variables to health shifts. Analyses of metabolic stress were accomplished through the quantification of lactate dehydrogenase and opine dehydrogenase activities. Through experimentation, treatment corals were observed to exhibit significant increases in alanopine and strombine dehydrogenase activities (ADH and SDH, respectively), but little to no lactate or octopine dehydrogenase activity. These findings indicate that not only is hypoxia a major source of increased coral stress, which occurs in response to invasive algae mat smothering, but provide novel insight into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH as possible tools for hypoxia mitigation.

scholarly journals Changes to coral health and metabolic activity under oxygen deprivation

2016 ◽  
Author(s):  
James WA Murphy ◽  
Robert H Richmond
Keyword(s):  
Critical Role ◽  
Metabolic Stress ◽  
Oxygen Deprivation ◽  
Tissue Loss ◽  
Low Oxygen ◽  
Invasive Algae ◽  
Hypoxic Conditions ◽  
Coral Stress ◽  
Coral Health ◽  
Effect Of Oxygen

Scleractinian corals play a critical role in tropical marine ecosystems by providing essential structure and food for coral reef inhabitants. However, recent investigations have found an alarming increase in coral losses from a variety of stressors, which threatens the general health and resilience of tropical coastal ecosystems. The effect of oxygen deprivation on the health of Hawaiian corals based on local drivers is of particular concern. On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. This study evaluates changes in coral health and metabolism through the replication of hypoxic conditions in a laboratory setting in order to limit the contribution of additional environmental variables to health shifts. Analyses of metabolic stress were accomplished through the quantification of lactate dehydrogenase and opine dehydrogenase activities. Through experimentation, treatment corals were observed to exhibit significant increases in alanopine and strombine dehydrogenase activities (ADH and SDH, respectively), but little to no lactate or octopine dehydrogenase activity. These findings indicate that not only is hypoxia a major source of increased coral stress, which occurs in response to invasive algae mat smothering, but provide novel insight into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH as possible tools for hypoxia mitigation.

scholarly journals Cell-Free Hemoglobin Does Not Attenuate the Effects of SARS-CoV-2 Spike Protein S1 Subunit in Pulmonary Endothelial Cells

2021 ◽  
Vol 22 (16) ◽  
pp. 9041
Author(s):  
Sirsendu Jana ◽  
Michael R. Heaven ◽  
Abdu I. Alayash
Keyword(s):  
Endothelial Cells ◽  
Hypoxia Inducible Factor ◽  
Spike Protein ◽  
Receptor Interaction ◽  
Low Oxygen ◽  
Viral Receptor ◽  
Hypoxic Conditions ◽  
Viral Components ◽  
Induced Changes ◽  
The Impact

SARS-CoV-2 primarily infects epithelial airway cells that express the host entry receptor angiotensin-converting enzyme 2 (ACE2), which binds to the S1 spike protein on the surface of the virus. To delineate the impact of S1 spike protein interaction with the ACE2 receptor, we incubated the S1 spike protein with human pulmonary arterial endothelial cells (HPAEC). HPAEC treatment with the S1 spike protein caused disruption of endothelial barrier function, increased levels of numerous inflammatory molecules (VCAM-1, ICAM-1, IL-1β, CCL5, CXCL10), elevated mitochondrial reactive oxygen species (ROS), and a mild rise in glycolytic reserve capacity. Because low oxygen tension (hypoxia) is associated with severe cases of COVID-19, we also evaluated treatment with hemoglobin (HbA) as a potential countermeasure in hypoxic and normal oxygen environments in analyses with the S1 spike protein. We found hypoxia downregulated the expression of the ACE2 receptor and increased the critical oxygen homeostatic signaling protein, hypoxia-inducible factor (HIF-1α); however, treatment of the cells with HbA yielded no apparent change in the levels of ACE2 or HIF-1α. Use of quantitative proteomics revealed that S1 spike protein-treated cells have few differentially regulated proteins in hypoxic conditions, consistent with the finding that ACE2 serves as the host viral receptor and is reduced in hypoxia. However, in normoxic conditions, we found perturbed abundance of proteins in signaling pathways related to lysosomes, extracellular matrix receptor interaction, focal adhesion, and pyrimidine metabolism. We conclude that the spike protein alone without the rest of the viral components is sufficient to elicit cell signaling in HPAEC, and that treatment with HbA failed to reverse the vast majority of these spike protein-induced changes.

scholarly journals Impact of Pancreatic Rat Islet Density on Cell Survival during Hypoxia

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
A. Rodriguez-Brotons ◽  
W. Bietiger ◽  
C. Peronet ◽  
J. Magisson ◽  
C. Sookhareea ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Survival ◽  
Confined Space ◽  
Loss Of Function ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Normal Atmospheric Pressure ◽  
And Function ◽  
Islet Survival ◽  
The Impact

In bioartificial pancreases (BP), the number of islets needed to restore normoglycaemia in the diabetic patient is critical. However, the confinement of a high quantity of islets in a limited space may impact islet survival, particularly in regard to the low oxygen partial pressure (PO2) in such environments. The aim of the present study was to evaluate the impact of islet number in a confined space under hypoxia on cell survival. Rat islets were seeded at three different concentrations (150, 300, and 600 Islet Equivalents (IEQ)/cm2) and cultured in normal atmospheric pressure (160 mmHg) as well as hypoxic conditions (15 mmHg) for 24 hours. Cell viability, function, hypoxia-induced changes in gene expression, and cytokine secretion were then assessed. Notably, hypoxia appeared to induce a decrease in viability and increasing islet density exacerbated the observed increase in cellular apoptosis as well as the loss of function. These changes were also associated with an increase in inflammatory gene transcription. Taken together, these data indicate that when a high number of islets are confined to a small space under hypoxia, cell viability and function are significantly impacted. Thus, in order to improve islet survival in this environment during transplantation, oxygenation is of critical importance.

scholarly journals Long-Term Hypoxia Maintains a State of Dedifferentiation and Enhanced Stemness in Fetal Cardiovascular Progenitor Cells

2021 ◽  
Vol 22 (17) ◽  
pp. 9382
Author(s):  
Cole Knox ◽  
Victor Camberos ◽  
Lourdes Ceja ◽  
Andrea Monteon ◽  
Lorelei Hughes ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Early Stage ◽  
Low Oxygen ◽  
Hypoxic Conditions ◽  
Hypoxic Environment ◽  
Cell Mobilization ◽  
Islet 1 ◽  
The Impact

Early-stage mammalian embryos survive within a low oxygen tension environment and develop into fully functional, healthy organisms despite this hypoxic stress. This suggests that hypoxia plays a regulative role in fetal development that influences cell mobilization, differentiation, proliferation, and survival. The long-term hypoxic environment is sustained throughout gestation. Elucidation of the mechanisms by which cardiovascular stem cells survive and thrive under hypoxic conditions would benefit cell-based therapies where stem cell survival is limited in the hypoxic environment of the infarcted heart. The current study addressed the impact of long-term hypoxia on fetal Islet-1+ cardiovascular progenitor cell clones, which were isolated from sheep housed at high altitude. The cells were then cultured in vitro in 1% oxygen and compared with control Islet-1+ cardiovascular progenitor cells maintained at 21% oxygen. RT-PCR, western blotting, flow cytometry, and migration assays evaluated adaptation to long term hypoxia in terms of survival, proliferation, and signaling. Non-canonical Wnt, Notch, AKT, HIF-2α and Yap1 transcripts were induced by hypoxia. The hypoxic niche environment regulates these signaling pathways to sustain the dedifferentiation and survival of fetal cardiovascular progenitor cells.

scholarly journals COX-1/EP1R Inhibition Ameliorate Deficits in Adult Neurogenesis and Social Interaction via Alleviating NLRP3/ IL-1β Activation During Hypobaric Hypoxia

2020 ◽  
Author(s):  
Garima Chauhan ◽  
Gaurav Kumar ◽  
Koustav Roy ◽  
Punita Kumari ◽  
Shahnawaz Alam ◽  
...  
Keyword(s):  
Adult Neurogenesis ◽  
Hypobaric Hypoxia ◽  
Social Memory ◽  
Systematic Investigation ◽  
Low Oxygen ◽  
Neurogenic Niche ◽  
Hypoxic Conditions ◽  
Notable Increase ◽  
The Impact ◽  
Cox 1

Abstract BackgroundLow oxygen environments like hypobaric hypoxia (HH) are common nodes to various diseases: characterized by neuroinflammation, which is detrimental to the structural and functional aspects of hippocampal circuitry. Various hypoxic conditions also lead to elevation of NLRP3 mediated neuroinflammation that may contribute to cognitive deficits. Components of neurogenic niches like microglia and astrocyte are largely affected by neuroinflammation; however, a systematic investigation of the impact of NLRP3 mediated neuroinflammation on components of neurogenic niche during hypoxia (HH) remains elusive. MethodsIn this study, we simulated cerebral hypoxia via decreasing partial pressure of oxygen(HH). The effect of hypobaric hypoxic (1, 3 and 7 day at 25000 ft) on social memory, anxiety, adult neurogenesis change in the inflammatory milieu in DG was explored in detail. We explored the efficacy of COX-1 inhibitor (Valery salicylate, 5mg/kg/day,i.p), and EP1R antagonist (SC19220, 1mg/kg/day,i.p) on NLRP3 mediated neuroinflammation and associated maladies during HH. ResultsWe observed that HH exposure induced alteration in social and anxiety-like behavior post 7 day exposure along with perturbation in levels of BDNF, Serotonin and adult neurogenesis in the DG right from day 1. Moreover, significant elevated NLRP3, caspase-1, and IL-1β levels are observed during HH from day 1. Concomitantly, a notable increase in the COX-1/EP1 pathway in both activated microglia and astrocyte in DG was evident after 3HH exposure. Pharmacological COX-1 inhibitor and EP1 antagonist counteract the detrimental effects of HH exposure on social memory, adult neurogenesis, and NLRP3 inflammasome induction. ConclusionsThus, our data showed induction of the COX-1/EP1 pathway in glial cells is detrimental to adult neurogenesis and social memory, raising possibility that the COX-1/EP1 pathway as a plausible target for inflammasome related neurogenesis impairment.

scholarly journals Mechanisms controlling bacterial infection in myeloid cells under hypoxic conditions

2020 ◽  
Author(s):  
Inaya Hayek ◽  
Valentin Schatz ◽  
Christian Bogdan ◽  
Jonathan Jantsch ◽  
Anja Lührmann
Keyword(s):  
Bacterial Infections ◽  
Current Knowledge ◽  
Myeloid Cells ◽  
Low Oxygen ◽  
Complex Interplay ◽  
Tissue Microenvironment ◽  
The Past ◽  
Host Pathogen Interaction ◽  
Hypoxic Conditions ◽  
The Impact

Abstract Various factors of the tissue microenvironment such as the oxygen concentration influence the host–pathogen interaction. During the past decade, hypoxia-driven signaling via hypoxia-inducible factors (HIF) has emerged as an important factor that affects both the pathogen and the host. In this chapter, we will review the current knowledge of this complex interplay, with a particular emphasis given to the impact of hypoxia and HIF on the inflammatory and antimicrobial activity of myeloid cells, the bacterial responses to hypoxia and the containment of bacterial infections under oxygen-limited conditions. We will also summarize how low oxygen concentrations influence the metabolism of neutrophils, macrophages and dendritic cells. Finally, we will discuss the consequences of hypoxia and HIFα activation for the invading pathogen, with a focus on Pseudomonas aeruginosa, Mycobacterium tuberculosis, Coxiella burnetii, Salmonella enterica and Staphylococcus aureus. This includes a description of the mechanisms and microbial factors, which the pathogens use to sense and react to hypoxic conditions.

THE EFFECT OF BACTERIAL STRAINS ON THE ENZYMATIC ACTIVITY OF SOILS IN IMPACT ZONE OF ATAMAN LAKE

2020 ◽  
Author(s):  
V.V. Zinchenko ◽  
◽  
E.S Fedorenko ◽  
A.V Gorovtsov ◽  
T.M Minkina ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Dehydrogenase Activity ◽  
Contaminated Soil ◽  
Model Experiment ◽  
Impact Zone ◽  
Bacterial Strains ◽  
The Impact

As a result of the model experiment, an increase in the enzymatic activity of meadow chernozem of the impact zone of Ataman Lake with the introduction of a strains mixture of metal-resistant microorganisms into the soil was established. The experiment has shown that the application of bacterial strains increases the dehydrogenase activity of contaminated soil by 51.8% compared to the variant without remediation

USING FIELD DATA FOR THE EVALUATION OF THE IMPACT OF ULTRA-LOW FREQUENCY MOTIONS ON THE FATIGUE OF MOORING LINES

2019 ◽  
Author(s):  
Guilherme Borzacchiello ◽  
Carl Albrecht ◽  
Fabricio N Correa ◽  
Breno Jacob ◽  
Guilherme da Silva Leal
Keyword(s):  
Field Data ◽  
Low Frequency ◽  
Mooring Lines ◽  
The Impact

Influence of long-term fertilization on soil microbial biomass and dehydrogenase activity in relation to crop productivity in an acid Inceptisols

2019 ◽  
Vol 56 (3) ◽  
pp. 305-311
Author(s):  
Debasis Purohit ◽  
Mitali Mandal ◽  
Avisek Dash ◽  
Kumbha Karna Rout ◽  
Narayan Panda ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Dehydrogenase Activity ◽  
Nutrient Content ◽  
Crop Productivity ◽  
Maturity Stage ◽  
Microbial Biomass Nitrogen ◽  
Biological Potential ◽  
Initiation Stage ◽  
The Impact

An effective approach for improving nutrient use efficiency and crop productivity simultaneously through exploitation of biological potential for efficient acquisition and utilization of nutrients by crops is very much needed in this current era. Thus, an attempt is made here to investigate the impact of long term fertilization in the soil ecology in rice-rice cropping system in post kharif - 2015 in flooded tropical rice (Oryza sativa L.) in an acidic sandy soil. The experiment was laid out in a randomized block design with quadruplicated treatments. Soil samples at different growth stages of rice were collected from long term fertilizer experiment.The studied long-term manured treatments included 100 % N, 100% NP, 100 % NPK, 150 % NPK and 100 % NPK+FYM (5 t ha-1) and an unmanured control. Soil fertility status like SOC content and other available nutrient content has decreased continuously towards the crop growth period. Comparing the results of different treatments, it was found that the application of 100% NPK + FYM exhibited highest nutrient content in soils. With regards to microbial properties it was also observed that the amount of microbial biomass carbon (MBC) and microbial biomass nitrogen ( MBN) showed highest accumulation in 100 % NPK + FYM at maximum tillering stage of the rice. The results further reveal that dehydrogenase activity was maximum at panicle initiation stage and thereafter it decreases. Soil organic carbon content, MBC, MBN and dehydrogenase activity were significantly correlated with each other. Significant correlations were observed between rice yield and MBC at maturity stage( R2 = 0.94**) and panicle initiation stage( R2 = 0.92**) and available nitrogen content at maturity stage( R2 = 0.91**).

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