Thermal plasticity in coral reef symbionts is mediated by oxidation of membrane lipids

Abstract The oxidation of polyunsaturated fatty acids (PUFA) is a common stress response across biomes with potential to trigger impairment of cell growth and reproduction. The oxidative stress theory of coral bleaching induced by global warming has been widely accepted to explain coral reef decline, but its underlying physiological mechanism remains under debate. Here we used lipidomic and population density data to examine cell cultures of three coral reef symbionts after a heat shock (sudden rise of 12 °C for 4 hours). Heat tolerance in S. microadriaticum and C. goreaui was characterized by preservation of thylakoid-derived glycolipids. Conversely, heat sensitivity in B. minutum was linked to elevated concentrations of oxidized PUFA esterified to glycolipids, suggesting that culture growth had ceased due to severe oxidative damage. Our findings provide a basis to further understand the role played by oxidative stress in coral bleaching and reveal novel biomarkers for the monitoring of symbiont-coral health.

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Coral bleaching and disease should not be underestimated as causes of Caribbean coral reef decline

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2008.0606 ◽

2008 ◽

Vol 276 (1655) ◽

pp. 197-198 ◽

Cited By ~ 26

Author(s):

Caroline Rogers

Keyword(s):

Coral Reef ◽

Coral Bleaching ◽

Caribbean Coral ◽

Caribbean Coral Reef ◽

Reef Decline

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Will community calcification reflect reef accretion on future, degraded coral reefs?

10.5194/bg-2021-61 ◽

2021 ◽

Author(s):

Coulson A. Lantz ◽

William Leggat ◽

Jessica L. Bergman ◽

Alexander Fordyce ◽

Charlotte Page ◽

...

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Coral Bleaching ◽

Elevated Temperatures ◽

Coral Cover ◽

Coral Tissue ◽

Bleaching Event ◽

Bleached Coral ◽

Coral Health ◽

Percent Area

Abstract. Coral bleaching events continue to drive the degradation of coral reefs worldwide, causing a shift in the benthic community from coral to algae dominated ecosystems. Critically, this shift may decrease the capacity of degraded coral reef communities to maintain net positive accretion during warming-driven stress events (e.g., reef-wide coral bleaching). Here we measured rates of net ecosystem calcification (NEC) and net ecosystem production (NEP) on a degraded coral reef lagoon community (coral cover 20 %) during a reef-wide bleaching event in February of 2020 at Heron Island on the Great Barrier Reef. We found that during this bleaching event, rates of community NEP and NEC across replicate transects remained positive and did not change in response to bleaching. Repeated benthic surveys over a period of 20 d indicated an increase in the percent area of bleached coral tissue, corroborated by relatively low Symbiodiniaceae densities (~0.6 × 106 cm−2) and dark-adapted photosynthetic yields in photosystem II of corals (~0.5) sampled along each transect over this period. Given that a clear decline in coral health was not reflected in the overall community NEC estimates, it is possible that elevated temperatures in the water column that compromise coral health enhanced the thermodynamic favourability for calcification in other, ahermatypic benthic calcifiers. These data suggest that positive NEC on degraded reefs may not equate to the net positive accretion of reef structure in a future, warmer ocean. Critically, our study highlights that if coral cover continues to decline as predicted, NEC may no longer be an appropriate proxy for reef growth as the proportion of the community NEC signal owed to ahermatypic calcification increases and coral dominance on the reef decreases.

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CRYPTIC CAUSES AND MECHANISMS INVOLVED IN AGEING

INDIAN DRUGS ◽

10.53879/id.50.01.p0005 ◽

2013 ◽

Vol 50 (01) ◽

pp. 5-22

Author(s):

K Challabotla ◽

◽

D Banji ◽

O.J.F Banji ◽

Chilipi K Reddy

Keyword(s):

Oxidative Stress ◽

Developing Countries ◽

Molecular Basis ◽

Metabolic Disorders ◽

Natural Process ◽

Biological Functions ◽

Stress Theory ◽

Biochemical Alterations ◽

Organ Systems ◽

The Brain

Ageing is a natural process characterized by progressive deterioration of biological functions. Ageing causes both morphological as well as biochemical alterations in various body organs leading to deterioration of health. Proteins, enzymes and neurotransmitters are affected, which in turn can result in dysregulation of various pathways. WHO has reported that by 2020, three quarters of all deaths in developing countries will be age-associated. Currently more than 300 theories exist to explain the phenomenon of ageing; amongst them the oxidative stress theory of ageing is most studied and accepted for the molecular basis of ageing. All these processes can progress at an unprecedented pace on contact with triggering factors, leading to the development of pathological ageing. The probability of developing neurodegenerative and metabolic disorders is relatively high under such circumstances. This review emphasizes the theories and mechanisms of ageing and an overview on the aspects of age associated biochemical changes and the implications on the brain, liver and various organ systems.

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Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

Oxidative Medicine and Cellular Longevity ◽

10.1155/2013/528935 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 29

Author(s):

Ken Shinmura

Keyword(s):

Oxidative Stress ◽

Free Radical ◽

Oxidative Damage ◽

Caloric Restriction ◽

Functional Decline ◽

Cellular Damage ◽

Free Radical Theory ◽

Radical Theory ◽

Stress Theory

The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

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Effects Of Climate-Induced Coral Bleaching On Coral-Reef Fishes ‚Äî Ecological And Economic Consequences

Oceanography and Marine Biology - Oceanography and Marine Biology - An Annual Review ◽

10.1201/9781420065756.ch6 ◽

2008 ◽

pp. 251-296 ◽

Cited By ~ 273

Author(s):

Morgan Pratchett ◽

Philip Munday ◽

Shaun Wilson ◽

Nicholas Graham ◽

Joshua Cinner ◽

...

Keyword(s):

Coral Reef ◽

Coral Bleaching ◽

Reef Fishes ◽

Coral Reef Fishes ◽

Economic Consequences

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Heme oxygenase-1 induction by hemin prevents oxidative stress-induced acute cholestasis in the rat

Clinical Science ◽

10.1042/cs20180675 ◽

2019 ◽

Vol 133 (1) ◽

pp. 117-134 ◽

Cited By ~ 7

Author(s):

Pamela L. Martín ◽

Paula Ceccatto ◽

María V. Razori ◽

Daniel E.A. Francés ◽

Sandra M.M. Arriaga ◽

...

Keyword(s):

Oxidative Stress ◽

Heme Oxygenase ◽

Bile Flow ◽

Driving Forces ◽

Membrane Lipids ◽

Ex Vivo ◽

Heme Oxygenase 1 ◽

Canalicular Transporters

Abstract We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.

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Analysis of composition and abundance of viral communities associated with coral \(\textit{Acropora formosa}\)

ACADEMIA JOURNAL OF BIOLOGY ◽

10.15625/2615-9023/15595 ◽

2021 ◽

Vol 43 (3) ◽

pp. 113-123

Author(s):

Doan Thi Nhung ◽

Bui Van Ngoc

Keyword(s):

Economic Development ◽

Coral Bleaching ◽

Coastal Communities ◽

Marine Animals ◽

Coral Mucus ◽

Bleached Coral ◽

The World ◽

Viral Communities ◽

Acropora Formosa ◽

Coral Health

Coral reefs harbor the extraordinary biodiversity and not only provide livelihoods for coastal communities but also play a crucial role in economic development generally. Unfortunately, they are in decline in Vietnam and around the world because mass coral bleaching events have become more common worldwide. However, little is discovered, about viruses that infect corals and their symbionts. Herein, we present metagenomic analyses of the viral communities in coral mucus associated with healthy and bleached coral Acropora formosa which was collected at Con Dao Island, Vietnam. Interestingly, the number of viral species in bleached specimens are higher than those in healthy status. Viruses similar to those that infect humans and some marine animals also appeared in the coral viral assemblage. The results indicated that the proportion of shared viruses were quite small, and represented extremely abundance. Among the phage identified, vibriophage and cyanophage were only presented in healthy and bleached coral, respectively. Therefore, coral-associated viruses could prospectively infect all constituents of the holobiont - coral, microalgal and microbial. Thus, we expect viruses to be illustrated prominently in the preservation and breakdown of coral health.

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Genotype by environment interactions in coral bleaching

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0177 ◽

2021 ◽

Vol 288 (1946) ◽

pp. 20210177

Author(s):

Crawford Drury ◽

Diego Lirman

Keyword(s):

Coral Bleaching ◽

Environmental Gradients ◽

Explanatory Power ◽

Cell Signalling ◽

Conservation Strategies ◽

Acropora Cervicornis ◽

Genotype By Environment ◽

Significant Enrichment ◽

Reef Tract ◽

Reef Decline

Climate-driven reef decline has prompted the development of next-generation coral conservation strategies, many of which hinge on the movement of adaptive variation across genetic and environmental gradients. This process is limited by our understanding of how genetic and genotypic drivers of coral bleaching will manifest in different environmental conditions. We reciprocally transplanted 10 genotypes ofAcropora cervicornisacross eight sites along a 60 km span of the Florida Reef Tract and documented significant genotype × environment interactions in bleaching response during the severe 2015 bleaching event. Performance relative to site mean was significantly different between genotypes and can be mostly explained by ensemble models of correlations with genetic markers. The high explanatory power was driven by significant enrichment of loci associated DNA repair, cell signalling and apoptosis. No genotypes performed above (or below) bleaching average at all sites, so genomic predictors can provide practitioners with ‘confidence intervals' about the chance of success in novel habitats. These data have important implications for assisted gene flow and managed relocation, and their integration with traditional active restoration.

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