Transcriptional responses, metabolic activity and mouthpart deformities in natural populations ofchironomus ripariuslarvae exposed to environmental pollutants

AbstractSubcellular organelles communicate with each other to regulate function and coordinate responses to changing cellular conditions. The physical-functional coupling of the endoplasmic reticulum (ER) with mitochondria allows for the direct transfer of Ca2+ between organelles and is an important avenue for rapidly increasing mitochondrial metabolic activity. As such, increasing ER−mitochondrial coupling can boost the generation of ATP that is needed to restore homeostasis in the face of cellular stress. The mitochondrial unfolded protein response (mtUPR) is activated by the accumulation of unfolded proteins in mitochondria. Retrograde signaling from mitochondria to the nucleus promotes mtUPR transcriptional responses aimed at restoring protein homeostasis. It is currently unknown whether the changes in mitochondrial−ER coupling also play a role during mtUPR stress. We hypothesized that mitochondrial stress favors an expansion of functional contacts between mitochondria and ER, thereby increasing mitochondrial metabolism as part of a protective response. Hela cells were treated with doxycycline, an antibiotic that inhibits the translation of mitochondrial-encoded proteins to create protein disequilibrium. Treatment with doxycycline decreased the abundance of mitochondrial encoded proteins while increasing expression of CHOP, C/EBPβ, ClpP, and mtHsp60, markers of the mtUPR. There was no change in either mitophagic activity or cell viability. Furthermore, ER UPR was not activated, suggesting focused activation of the mtUPR. Within 2 h of doxycycline treatment, there was a significant increase in physical contacts between mitochondria and ER that was distributed throughout the cell, along with an increase in the kinetics of mitochondrial Ca2+ uptake. This was followed by the rise in the rate of oxygen consumption at 4 h, indicating a boost in mitochondrial metabolic activity. In conclusion, an early phase of the response to doxycycline-induced mitochondrial stress is an increase in mitochondrial−ER coupling that potentiates mitochondrial metabolic activity as a means to support subsequent steps in the mtUPR pathway and sustain cellular adaptation.

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In vitro cultivation of primary intestinal cells from Eisenia fetida as basis for ecotoxicological studies

Ecotoxicology ◽

10.1007/s10646-021-02495-2 ◽

2021 ◽

Author(s):

Simon A. B. Riedl ◽

Matthias Völkl ◽

Anja Holzinger ◽

Julia Jasinski ◽

Valérie Jérôme ◽

...

Keyword(s):

Silver Nanoparticles ◽

Metal Ions ◽

Metabolic Activity ◽

Eisenia Fetida ◽

Environmental Pollutants ◽

Model Organism ◽

Intestinal Cells ◽

In Vitro Cultivation ◽

Size Dependent

AbstractThe earthworm Eisenia fetida is a commonly used model organism for unspecific soil feeders in ecotoxicological studies. Its intestinal cells are the first to encounter possible pollutants co-ingested by the earthworm, which makes them prime candidates for studies of toxic effects of environmental pollutants on the cellular as compared to the organismic level. In this context, the aim of this study was to demonstrate the suitability of preparations of primary intestinal E. fetida cells for in vitro ecotoxicological studies. For this purpose, a suitable isolation and cultivation protocol was established. Cells were isolated directly from the intestine, maintaining >85% viability during subsequent cultivations (up to 144 h). Exposure to established pollutants and soil elutriates comprising silver nanoparticles and metal ions (Cu2+, Cd2+) induced a significant decrease in the metabolic activity of the cells. In case of microplastic particles (MP particles), namely 0.2, 0.5, 2.0, and 3.0 µm diameter polystyrene (PS) beads as well as 0.5 and 2.0 µm diameter polylactic acid (PLA) beads, no active uptake was observed. Slight positive as well as negative dose and size dependent effects on the metabolism were seen, which to some extent might correlate with effects on the organismic level.

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Arsenite Oxidase Also Functions as an Antimonite Oxidase

Applied and Environmental Microbiology ◽

10.1128/aem.02981-14 ◽

2015 ◽

Vol 81 (6) ◽

pp. 1959-1965 ◽

Cited By ~ 36

Author(s):

Qian Wang ◽

Thomas P. Warelow ◽

Yoon-Suk Kang ◽

Christine Romano ◽

Thomas H. Osborne ◽

...

Keyword(s):

Environmental Protection Agency ◽

Large Subunit ◽

Environmental Pollutants ◽

Transcriptional Responses ◽

Oxidation Activity ◽

Content Type ◽

Genes Encoding ◽

Basic Features

ABSTRACTArsenic and antimony are toxic metalloids and are considered priority environmental pollutants by the U.S. Environmental Protection Agency. Significant advances have been made in understanding microbe-arsenic interactions and how they influence arsenic redox speciation in the environment. However, even the most basic features of how and why a microorganism detects and reacts to antimony remain poorly understood. Previous work withAgrobacterium tumefaciensstrain 5A concluded that oxidation of antimonite [Sb(III)] and arsenite [As(III)] required different biochemical pathways. Here, we show within vivoexperiments that a mutation inaioA[encoding the large subunit of As(III) oxidase] reduces the ability to oxidize Sb(III) by approximately one-third relative to the ability of the wild type. Further,in vitrostudies with the purified As(III) oxidase fromRhizobiumsp. strain NT-26 (AioA shares 94% amino acid sequence identity with AioA ofA. tumefaciens) provide direct evidence of Sb(III) oxidation but also show a significantly decreasedVmaxcompared to that of As(III) oxidation. TheaioBAgenes encoding As(III) oxidase are induced by As(III) but not by Sb(III), whereasarsRgene expression is induced by both As(III) and Sb(III), suggesting that detection and transcriptional responses for As(III) and Sb(III) differ. While Sb(III) and As(III) are similar with respect to cellular extrusion (ArsB or Acr3) and interaction with ArsR, they differ in the regulatory mechanisms that control the expression of genes encoding the different Ars or Aio activities. In summary, this study documents an enzymatic basis for microbial Sb(III) oxidation, although additional Sb(III) oxidation activity also is apparent in this bacterium.

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Anti-parasite treatment removes negative effects of environmental pollutants on reproduction in an Arctic seabird

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2006.3687 ◽

2006 ◽

Vol 273 (1605) ◽

pp. 3117-3122 ◽

Cited By ~ 33

Author(s):

Jan O Bustnes ◽

Kjell E Erikstad ◽

Sveinn A Hanssen ◽

Torkild Tveraa ◽

Ivar Folstad ◽

...

Keyword(s):

Polychlorinated Biphenyl ◽

Environmental Pollutants ◽

Natural Populations ◽

Nesting Success ◽

Return Rate ◽

Negative Effects ◽

Anthropogenic Pollutants ◽

Study Population ◽

Breeding Seasons ◽

Reproductive Consequences

Recent studies have shown that the detrimental effects of anthropogenic pollutants may be worse if organisms are exposed to natural stress. In this study, we examined whether negative effects of organochlorines (OCs) could be influenced by parasites. In two breeding seasons, we administered an anti-helminthic drug to groups of breeding glaucous gulls ( Larus hyperboreus ), whereas control groups were placebo treated. In all birds, blood residues of the most important OCs in the study population (hexachlorobenzene, oxychlordane, p , p ′-dichlorodiphenyldichloroethylene and polychlorinated biphenyl), were measured. The relationships between OCs and fitness components (i.e. nesting success and return rate between breeding seasons) were then compared between the birds receiving anti-parasite treatment and the controls. Among untreated males, higher blood residues of OCs were associated with lowered nesting success, while in males receiving anti-parasite treatment, there was no detrimental effect of OCs on fitness. Return rate was not affected by treatment or OCs. Our findings suggest that parasites may be an important factor in triggering reproductive effects of such pollutants, and that relatively low levels of OCs may have serious reproductive consequences in natural populations when stress from other sources is high.

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Ex Vivo Cultivation Of Primary Intestinal Cells From Eisenia Fetida As Basis For Ecotoxicological Studies

10.21203/rs.3.rs-613888/v1 ◽

2021 ◽

Author(s):

Simon A.B. Riedl ◽

Matthias Voelkl ◽

Anja Holzinger ◽

Julia Jasinski ◽

Valérie Jérôme ◽

...

Keyword(s):

Silver Nanoparticles ◽

Metal Ions ◽

Polylactic Acid ◽

Metabolic Activity ◽

Eisenia Fetida ◽

Ex Vivo ◽

Environmental Pollutants ◽

Model Organism ◽

Intestinal Cells ◽

Short Time

Abstract The earthworm Eisenia fetida is a commonly used model organism for unspecific soil feeders in ecotoxicological studies. Its intestinal cells are the first to encounter possible pollutants co-ingested by the earthworm, which makes them prime candidates for studies of toxic effects of environmental pollutants on the cellular as compared to the organismic level. Here, cells are isolated directly from the intestine, maintaining > 90% viability during subsequent short-time cultivations (up to 144 h). Exposure to established toxins comprising silver nanoparticles and metal ions (Cu2+, Cd2+) induced a significant decrease in the metabolic activity of the cells. In presence of microplastic particles (MP particles), namely 0.2, 0.5, 2.0, and 3.0 µm diameter polystyrene (PS) beads as well as 0.5 and 2.0 µm diameter polylactic acid (PLA) beads, no active uptake and no effect on the metabolic activity of the cells was observed. This suggests a tissue rather than cell related basis for the previously observed ecotoxicological effects of MP in case of Eisenia fetida.

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Ultrastructure and Drug Metabolism in the Developing Guinea Pig

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100073131 ◽

1973 ◽

Vol 31 ◽

pp. 538-539

Author(s):

W. Kuenzig ◽

M. Boublik ◽

J.J. Kamm ◽

J.J. Burns

Keyword(s):

Guinea Pig ◽

Metabolic Activity ◽

Animal Species ◽

Adult Animal ◽

Smooth Endoplasmic Reticulum ◽

Fetal Life ◽

Mixed Function Oxidase ◽

Cytochrome P 450 ◽

Microsomal Mixed Function Oxidase ◽

Mixed Function Oxidase Activity

Unlike a variety of other animal species, such as the rabbit, mouse or rat, the guinea pig has a relatively long gestation period and is a more fully developed animal at birth. Kuenzig et al. reported that drug metabolic activity which increases very slowly during fetal life, increases rapidly after birth. Hepatocytes of a 3-day old neonate metabolize drugs and reduce cytochrome P-450 at a rate comparable to that observed in the adult animal. Moreover the administration of drugs like phenobarbital to pregnant guinea pigs increases the microsomal mixed function oxidase activity already in the fetus.Drug metabolic activity is, generally, localized within the smooth endoplasmic reticulum (SER) of the hepatocyte.

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Fibroblasts During Hypertrophic Scar Formation and Resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072587 ◽

1973 ◽

Vol 31 ◽

pp. 428-429

Author(s):

C. W. Kischer

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Cell Proliferation ◽

Fine Structure ◽

Metabolic Activity ◽

Hypertrophic Scar ◽

Normal Skin ◽

Ground Substance ◽

Hypertrophic Scars ◽

Scanning Electron

The morphology of the fibroblasts changes markedly as the healing period from burn wounds progresses, through development of the hypertrophic scar, to resolution of the scar by a self-limiting process of maturation or therapeutic resolution. In addition, hypertrophic scars contain an increased cell proliferation largely made up of fibroblasts. This tremendous population of fibroblasts seems congruous with the abundance of collagen and ground substance. The fine structure of these cells should reflect some aspects of the metabolic activity necessary for production of the scar, and might presage the stage of maturation.A comparison of the fine structure of the fibroblasts from normal skin, different scar types, and granulation tissue has been made by transmission (TEM) and scanning electron microscopy (SEM).

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Ultrastructural aspects of gymnosperms reproductive organs tissues due to their functional condition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083060 ◽

1978 ◽

Vol 36 (2) ◽

pp. 440-441

Author(s):

G. M. Kozubov

Keyword(s):

Metabolic Activity ◽

Functional Condition ◽

Reproductive Organs ◽

Considerable Change ◽

Complicated Structure ◽

Tetrad Stage ◽

Ubisch Bodies ◽

Similar Organization ◽

Female Reproductive Organs ◽

High Metabolic Activity

The ultrastructure of reproductive organs of pine, spruce, larch and ginkgo was investigated. It was found that the male reproductive organs possess similar organization. The most considerable change in the ultrastructure of the microsporocytes occur in meiosis. Sporoderm is being laid at the late tetrad stage. The cells of the male gameto-phyte are distinguished according to the metabolic activity of the or- ganells. They are most weakly developed in the spermiogenic cell. Ta-petum of the gymnosperms is of the periplasmodic - secretorial type. The Ubisch bodies which possess similar structure in the types investigated but are specific in details in different species are produced in tapetum.Parietal and subepidermal layers are distinguished for their high metabolic activity and are capable of the autonomous photosynthesis. Female reproductive organs differ more greatly in their struture and have the most complicated structure in primitive groups. On the first stages of their formation the inner cells of nucellus are transformed into the nucellar tapetum in which the structures similar to the Ubisch bodies taking part in the formation of the sporoderm of female gametophyte have been found.

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High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103875 ◽

1988 ◽

Vol 46 ◽

pp. 362-363

Author(s):

G. E. Tyson ◽

M. J. Song

Keyword(s):

Electron Microscopy ◽

High Voltage ◽

Brine Shrimp ◽

Natural Populations ◽

Three Dimensional ◽

Dimensional Structure ◽

High Voltage Electron Microscopy ◽

Voltage Electron ◽

High Voltage Electron ◽

Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

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Effect of acid deposition on trichome morphology and dogwood anthracnose biology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124604 ◽

1992 ◽

Vol 50 (1) ◽

pp. 840-841

Author(s):

Kyle T. Thornham ◽

R. Jay Stipes ◽

Randolph L. Grayson

Keyword(s):

Acid Deposition ◽

Disease Incidence ◽

Natural Populations ◽

Tree Disease ◽

Flowering Dogwood ◽

Discula Destructiva ◽

Disease Induction ◽

Dogwood Anthracnose ◽

Trichome Morphology ◽

Precipitation Events

Dogwood anthracnose, caused by Discula destructiva (1), is another new catastrophic tree disease that has ravaged natural populations of the flowering dogwood (Cornus florida) in the Appalachians over the past 15 years, and the epidemic is prognosticated to continue (2). An estimated 9.5 million acres have been affected, primarily in the Appalachian Mountains, from VA southwards, alone, and an estimated 50% of all dogwoods in PA have been killed. Since acid deposition has been linked experimentally with disease induction, and since the disease incidence and severity are more pronounced at higher elevations where lower pH precipitation events occur, we investigated the effect of acidic foliar sprays on moiphologic changes in the foliar cuticle and trichomes (3), the initial sites of infection and foci of Discula sporulation.

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