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  1. Article ; Online: Starvation hardiness as preadaptation for life in subterranean habitats.

    Kozel, Peter / Novak, Tone / Janžekovič, Franc / Lipovšek, Saška

    Scientific reports

    2023  Volume 13, Issue 1, Page(s) 9643

    Abstract: Most subterranean habitats, especially caves, are considered extreme environments, mainly because of the limited and erratic food supply and constant darkness. In temperate regions, many climatic conditions, such as temperature and air humidity, are ... ...

    Abstract Most subterranean habitats, especially caves, are considered extreme environments, mainly because of the limited and erratic food supply and constant darkness. In temperate regions, many climatic conditions, such as temperature and air humidity, are periodically less adverse or even more favourable in caves than the harsh seasonal weather on the surface. Accordingly, many animal species search for hibernacula in caves. These overwintering, non-specialized subterranean species (non-troglobionts) show various modes of dormancy and ongoing development. Since they do not feed, they all undergo periodic starvation, a preadaptation, which might evolve in permanent starvation hardiness, such as found in most specialized subterranean species (troglobionts). To this end, we performed a comparative analysis of energy-supplying compounds in eleven most common terrestrial non-troglobiont species during winter in central European caves. We found highly heterogeneous responses to starvation, which are rather consistent with the degree of energetic adaptation to the habitat than to overwintering mode. The consumption of energy-supplying compounds was strongly higher taxa-dependant; glycogen is the main energy store in gastropods, lipids in insects, and arachnids rely on both reserve compounds. We assume that permanent starvation hardiness in specialized subterranean species might evolved in many different ways as shown in this study.
    MeSH term(s) Animals ; Acclimatization ; Arachnida ; Caves ; Extreme Environments ; Gastropoda ; Starvation
    Language English
    Publishing date 2023-06-14
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-023-36556-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Malpighian tubules in harvestmen.

    Lipovšek, Saška / Kozel, Peter / Leitinger, Gerd / Novak, Tone

    Protoplasma

    2021  Volume 258, Issue 5, Page(s) 1145–1153

    Abstract: In arachnids, the Malpighian tubules (MTs), coxal glands and stercoral pockets are capable of collecting and removing excreta from the body. The presence of the MTs among Opiliones was evidenced for the first time in Amilenus aurantiacus in 2015. ... ...

    Abstract In arachnids, the Malpighian tubules (MTs), coxal glands and stercoral pockets are capable of collecting and removing excreta from the body. The presence of the MTs among Opiliones was evidenced for the first time in Amilenus aurantiacus in 2015. Individuals undergo a winter diapause subterranean habitats. Here, we provided the morphological and cytological description of the MTs and asked whether their structure and ultrastructure change during the winter diapause. We studied the changes using light and transmission electron microscopy. The MTs consisted of the ureter and a pair of long, lateral blind-ended tubules, forming a long loop in the opisthosoma, and a coiled, terminal ball in the prosoma. The MTs were uniform, composed of a single-cell type, a monolayer of cuboidal epithelial cells, and the basal lamina. The cell ultrastructure was quite comparable to those in other arthropods, except for very long infoldings of the basal membrane protruding close to the nucleus. Except for spherite exploitation, no changes were observed in the ultrastructure of the MT epithelial cells during overwintering. We suggest that the analogous MTs in A. aurantiacus, and the nephron anatomies, along with a single-cell-type MT epithelium, might be of advantage in modelled studies of the nephron.
    MeSH term(s) Animals ; Ecosystem ; Epithelial Cells ; Humans ; Malpighian Tubules ; Microscopy, Electron, Transmission ; Seasons
    Language English
    Publishing date 2021-03-29
    Publishing country Austria
    Document type Journal Article
    ZDB-ID 123809-7
    ISSN 1615-6102 ; 0033-183X
    ISSN (online) 1615-6102
    ISSN 0033-183X
    DOI 10.1007/s00709-021-01634-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Western diet-induced ultrastructural changes in mouse pancreatic acinar cells.

    Lipovšek, Saška / Dolenšek, Jurij / Dariš, Barbara / Valladolid-Acebes, Ismael / Vajs, Tanja / Leitinger, Gerd / Stožer, Andraž / Skelin Klemen, Maša

    Frontiers in cell and developmental biology

    2024  Volume 12, Page(s) 1380564

    Abstract: Mouse models of diet-induced type 2 diabetes mellitus provide powerful tools for studying the structural and physiological changes that are related to the disease progression. In this study, diabetic-like glucose dysregulation was induced in mice by ... ...

    Abstract Mouse models of diet-induced type 2 diabetes mellitus provide powerful tools for studying the structural and physiological changes that are related to the disease progression. In this study, diabetic-like glucose dysregulation was induced in mice by feeding them a western diet, and light and transmission electron microscopy were used to study the ultrastructural changes in the pancreatic acinar cells. Acinar necrosis and vacuolization of the cytoplasm were the most prominent features. Furthermore, we observed intracellular and extracellular accumulation of lipid compounds in the form of lipid droplets, structural enlargement of the cisternae of the rough endoplasmic reticulum (RER), and altered mitochondrial morphology, with mitochondria lacking the typical organization of the inner membrane. Last, autophagic structures, i.e., autophagosomes, autolysosomes, and residual bodies, were abundant within the acinar cells of western diet-fed mice, and the autolysosomes contained lipids and material of varying electron density. While diets inducing obesity and type 2 diabetes are clearly associated with structural changes and dysfunction of the endocrine pancreas, we here demonstrate the strong effect of dietary intervention on the structure of acinar cells in the exocrine part of the organ before detectable changes in plasma amylase activity, which may help us better understand the development of non-alcoholic fatty pancreas disease and its association with endo- and exocrine dysfunction.
    Language English
    Publishing date 2024-03-14
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2737824-X
    ISSN 2296-634X
    ISSN 2296-634X
    DOI 10.3389/fcell.2024.1380564
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  4. Article: Malpighian tubules in harvestmen

    Lipovšek, Saška / Kozel, Peter / Leitinger, Gerd / Novak, Tone

    Protoplasma. 2021 Sept., v. 258, no. 5

    2021  

    Abstract: In arachnids, the Malpighian tubules (MTs), coxal glands and stercoral pockets are capable of collecting and removing excreta from the body. The presence of the MTs among Opiliones was evidenced for the first time in Amilenus aurantiacus in 2015. ... ...

    Abstract In arachnids, the Malpighian tubules (MTs), coxal glands and stercoral pockets are capable of collecting and removing excreta from the body. The presence of the MTs among Opiliones was evidenced for the first time in Amilenus aurantiacus in 2015. Individuals undergo a winter diapause subterranean habitats. Here, we provided the morphological and cytological description of the MTs and asked whether their structure and ultrastructure change during the winter diapause. We studied the changes using light and transmission electron microscopy. The MTs consisted of the ureter and a pair of long, lateral blind-ended tubules, forming a long loop in the opisthosoma, and a coiled, terminal ball in the prosoma. The MTs were uniform, composed of a single-cell type, a monolayer of cuboidal epithelial cells, and the basal lamina. The cell ultrastructure was quite comparable to those in other arthropods, except for very long infoldings of the basal membrane protruding close to the nucleus. Except for spherite exploitation, no changes were observed in the ultrastructure of the MT epithelial cells during overwintering. We suggest that the analogous MTs in A. aurantiacus, and the nephron anatomies, along with a single-cell-type MT epithelium, might be of advantage in modelled studies of the nephron.
    Keywords Opiliones ; diapause ; epithelium ; excreta ; overwintering ; transmission electron microscopy ; ultrastructure ; ureter
    Language English
    Dates of publication 2021-09
    Size p. 1145-1153.
    Publishing place Springer Vienna
    Document type Article
    ZDB-ID 123809-7
    ISSN 1615-6102 ; 0033-183X
    ISSN (online) 1615-6102
    ISSN 0033-183X
    DOI 10.1007/s00709-021-01634-0
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Autophagy in the fat body cells of the cave cricket Troglophilus neglectus Krauss, 1878 (Rhaphidophoridae, Saltatoria) during overwintering.

    Lipovšek, Saška / Novak, Tone

    Protoplasma

    2016  Volume 253, Issue 2, Page(s) 457–466

    Abstract: The cave cricket Troglophilus neglectus regularly overwinters for 4-5 months in hypogean habitats. Winter dormancy is a natural starvation period, providing the opportunity to study autophagy under natural conditions. We aimed to evaluate the autophagic ... ...

    Abstract The cave cricket Troglophilus neglectus regularly overwinters for 4-5 months in hypogean habitats. Winter dormancy is a natural starvation period, providing the opportunity to study autophagy under natural conditions. We aimed to evaluate the autophagic activity in adipocytes and urocytes of the fat body in three time frames: directly before overwintering, in the middle of dormancy, and at its end. For this purpose, we sampled individuals in caves. The cell ultrastructure was studied by transmission electron microscopy (TEM) and the abundance of autophagosomes by immunofluorescence microscopy (IFM), applying the widely used, specific immunolabeling marker microtubule-associated protein 1 light chain 3 (LC3). Before overwintering, TEM revealed scarce autophagosomes and residual bodies in the adipocytes and none in the urocytes. Congruently, IFM showed a very limited or no reaction. In the middle and at the end of overwintering, in both cell types, phagophores, autophagosomes, autolysosomes, and residual bodies were identified by TEM, while LC3 immunolabeling for detecting autophagosomes showed a conspicuous positive reaction. Both methods revealed that there were no significant differences between the sexes in any time frame. Minimal autophagic activity was detected before the winter dormancy, and it gradually intensified till the end of overwintering, probably because reserve proteins in protein granula are not composed of all the required amino acids. We conclude that in T. neglectus, autophagy is a substantial response to starvation and supports homeostatic processes during winter dormancy by supplying cells with nutrients.
    MeSH term(s) Adipocytes/physiology ; Adipocytes/ultrastructure ; Animals ; Autophagosomes/ultrastructure ; Autophagy ; Fat Body/ultrastructure ; Female ; Gryllidae/ultrastructure ; Male ; Seasons
    Language English
    Publishing date 2016-03
    Publishing country Austria
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 123809-7
    ISSN 1615-6102 ; 0033-183X
    ISSN (online) 1615-6102
    ISSN 0033-183X
    DOI 10.1007/s00709-015-0824-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Notes on coexistence of closely related Leiobunum rupestre and L. subalpinum (Opiliones, Eupnoi, Sclerosomatidae).

    Kozel, Peter / Delakorda, Miha / Komposch, Christian / Novak, Ljuba Slana / Novak, Tone / Lipovšek, Saška

    Zootaxa

    2021  Volume 4984, Issue 1, Page(s) 3442

    Abstract: Two closely related, syntopic species, Leiobunum rupestre and L. subalpinum, spend the day at apparently randomly distributed resting sites. In this preliminary research, we studied differences in their microclimatic preferences at a locality in the ... ...

    Abstract Two closely related, syntopic species, Leiobunum rupestre and L. subalpinum, spend the day at apparently randomly distributed resting sites. In this preliminary research, we studied differences in their microclimatic preferences at a locality in the Pohorje Mts., Slovenia. We measured air temperature and relative humidity at individual resting sites, and found that L. subalpinum occupied a slightly wider air temperature-relative humidity ecospace as compared to L. rupestre. Individuals of L. rupestre rested at more humid sites than L. subalpinum. Regression analyses revealed that the presence of L. rupestre was most likely at resting sites with air temperature in the range of 1217°C and with relative air humidity of 98.1%. In contrast, the presence of L. subalpinum was most likely at resting sites with air temperature 23.1°C and relative air humidity in the range of 6585%. Nevertheless, microclimatic niches of both species overlapped almost completely, indicating that niche filtering may allow the coexistence of the two species.
    Language English
    Publishing date 2021-06-10
    Publishing country New Zealand
    Document type Journal Article
    ISSN 1175-5334
    ISSN (online) 1175-5334
    DOI 10.11646/zootaxa.4984.1.5
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  7. Article ; Online: Ultrastructure of spherites in the midgut diverticula and Malpighian tubules of the harvestman Amilenus aurantiacus during the winter diapause.

    Lipovšek, Saška / Novak, Tone / Dariš, Barbara / Hofer, Ferdinand / Leitinger, Gerd / Letofsky-Papst, Ilse

    Histochemistry and cell biology

    2021  Volume 157, Issue 1, Page(s) 107–118

    Abstract: Amilenus aurantiacus overwinter in diapause, a natural starvation period, in hypogean habitats. The structure of spherites in the midgut diverticula (MD) and Malpighian tubules (MT) has been studied comparatively by light microscopy and TEM to detect ... ...

    Abstract Amilenus aurantiacus overwinter in diapause, a natural starvation period, in hypogean habitats. The structure of spherites in the midgut diverticula (MD) and Malpighian tubules (MT) has been studied comparatively by light microscopy and TEM to detect eventual differences in mineral consumption in the beginning and at the end of the starvation period in these organs (MD and MT) associated with digestive processes. The chemical composition of spherites was examined by combining energy-dispersive X-ray spectroscopy (EDXS), electron energy-loss spectroscopy (EELS) and energy-filtered TEM (EFTEM). The structure of the spherites changed during overwintering in both organs. At the beginning of overwintering, the spherites were composed of densely packed concentric layers of electron-dense and electron-lucent material. In the middle and at the end of overwintering, the electron-lucent layers between the layers of material indicated the loss of some material. The chemical composition of the spherites changed only in the MD; at the beginning of overwintering, these contained Si, O, C and Fe, while later there was no more Fe. In contrast, spherites in the MT were composed of Si, O, C and Ca throughout overwintering. A less intensive exploitation of the MD spherites was probably due to complete cessation of digestive and other cell activity in this organ during the winter diapause; activity of the MT slowed, but continued removing the cell metabolites.
    MeSH term(s) Animals ; Diapause ; Digestive System ; Diverticulum ; Malpighian Tubules/ultrastructure ; Seasons
    Language English
    Publishing date 2021-11-05
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1222930-1
    ISSN 1432-119X ; 0301-5564 ; 0948-6143
    ISSN (online) 1432-119X
    ISSN 0301-5564 ; 0948-6143
    DOI 10.1007/s00418-021-02046-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Ultrastructure of fat body cells and Malpighian tubule cells in overwintering Scoliopteryx libatrix (Noctuoidea).

    Lipovšek, Saška / Janžekovič, Franc / Novak, Tone

    Protoplasma

    2017  Volume 254, Issue 6, Page(s) 2189–2199

    Abstract: The herald moths, Scoliopteryx libatrix, overwinter in hypogean habitats. The ultrastructure of their fat body (FB) cells and Malpighian tubule (MT) epithelial cells was studied by light microscopy and transmission electron microscopy, and essential ... ...

    Abstract The herald moths, Scoliopteryx libatrix, overwinter in hypogean habitats. The ultrastructure of their fat body (FB) cells and Malpighian tubule (MT) epithelial cells was studied by light microscopy and transmission electron microscopy, and essential biometric and biochemical measurements were performed. The FB was composed of adipocytes and sparse urocytes. The ultrastructure of both cells did not change considerably during this natural starvation period, except for rough endoplasmic reticulum (rER) which became more abundant in March females. In the cells, the reserve material consisted of numerous lipid droplets, glycogen rosettes, and protein granula. During overwintering, the lipid droplets diminished, and protein granula became laminated. The MTs consisted of a monolayer epithelium and individual muscle cells. The epithelial cells were attached to the basal lamina by numerous hemidesmosomes. The apical plasma membrane was differentiated into numerous microvilli, many of them containing mitochondria. Nuclei were surrounded by an abundant rER. There were numerous spherites in the perinuclear part of the cells. The basal plasma membrane formed infoldings with mitochondria in between. Nuclei were located either in the basal or in the central part of the cells. During overwintering, spherites were gradually exploited, and autophagic structures appeared: autophagosomes, autolysosomes, and residual bodies. There were no statistical differences between the sexes in any measured biometric and biochemical variables in the same time frames. The energy-supplying lipids and glycogen, and spherite stores were gradually spent during overwintering. In March, the augmented rER signified the intensification of synthetic processes prior to the epigean ecophase.
    MeSH term(s) Animals ; Fat Body/physiology ; Fat Body/ultrastructure ; Female ; Glycogen/metabolism ; Lipid Metabolism ; Male ; Malpighian Tubules/physiology ; Malpighian Tubules/ultrastructure ; Moths/physiology ; Moths/ultrastructure ; Seasons ; Torpor
    Chemical Substances Glycogen (9005-79-2)
    Language English
    Publishing date 2017-11
    Publishing country Austria
    Document type Journal Article
    ZDB-ID 123809-7
    ISSN 1615-6102 ; 0033-183X
    ISSN (online) 1615-6102
    ISSN 0033-183X
    DOI 10.1007/s00709-017-1110-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Autolysis Affects the Iron Cargo of Ferritins in Neurons and Glial Cells at Different Rates in the Human Brain.

    Sunkara, Sowmya / Radulović, Snježana / Lipovšek, Saška / Birkl, Christoph / Eggenreich, Stefan / Birkl-Toeglhofer, Anna Maria / Schinagl, Maximilian / Funk, Daniel / Stöger-Pollach, Michael / Haybaeck, Johannes / Goessler, Walter / Ropele, Stefan / Leitinger, Gerd

    Cellular and molecular neurobiology

    2023  Volume 43, Issue 6, Page(s) 2909–2923

    Abstract: Iron is known to accumulate in neurological disorders, so a careful balance of the iron concentration is essential for healthy brain functioning. An imbalance in iron homeostasis could arise due to the dysfunction of proteins involved in iron homeostasis. ...

    Abstract Iron is known to accumulate in neurological disorders, so a careful balance of the iron concentration is essential for healthy brain functioning. An imbalance in iron homeostasis could arise due to the dysfunction of proteins involved in iron homeostasis. Here, we focus on ferritin-the primary iron storage protein of the brain. In this study, we aimed to improve a method to measure ferritin-bound iron in the human post-mortem brain, and to discern its distribution in particular cell types and brain regions. Though it is known that glial cells and neurons differ in their ferritin concentration, the change in the number and distribution of iron-filled ferritin cores between different cell types during autolysis has not been revealed yet. Here, we show the cellular and region-wide distribution of ferritin in the human brain using state-of-the-art analytical electron microscopy. We validated the concentration of iron-filled ferritin cores to the absolute iron concentration measured by quantitative MRI and inductively coupled plasma mass spectrometry. We show that ferritins lose iron from their cores with the progression of autolysis whereas the overall iron concentrations were unaffected. Although the highest concentration of ferritin was found in glial cells, as the total ferritin concentration increased in a patient, ferritin accumulated more in neurons than in glial cells. Summed up, our findings point out the unique behaviour of neurons in storing iron during autolysis and explain the differences between the absolute iron concentrations and iron-filled ferritin in a cell-type-dependent manner in the human brain. The rate of loss of the iron-filled ferritin cores during autolysis is higher in neurons than in glial cells.
    MeSH term(s) Humans ; Iron/metabolism ; Ferritins/metabolism ; Neuroglia/metabolism ; Neurons/metabolism ; Brain/metabolism
    Chemical Substances Iron (E1UOL152H7) ; Ferritins (9007-73-2)
    Language English
    Publishing date 2023-03-15
    Publishing country United States
    Document type Journal Article
    ZDB-ID 283404-2
    ISSN 1573-6830 ; 0272-4340
    ISSN (online) 1573-6830
    ISSN 0272-4340
    DOI 10.1007/s10571-023-01332-w
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  10. Article: Ultrastructure of fat body cells and Malpighian tubule cells in overwintering Scoliopteryx libatrix (Noctuoidea)

    Lipovšek, Saška / Franc Janžekovič / Tone Novak

    Protoplasma. 2017 Nov., v. 254, no. 6

    2017  

    Abstract: The herald moths, Scoliopteryx libatrix, overwinter in hypogean habitats. The ultrastructure of their fat body (FB) cells and Malpighian tubule (MT) epithelial cells was studied by light microscopy and transmission electron microscopy, and essential ... ...

    Abstract The herald moths, Scoliopteryx libatrix, overwinter in hypogean habitats. The ultrastructure of their fat body (FB) cells and Malpighian tubule (MT) epithelial cells was studied by light microscopy and transmission electron microscopy, and essential biometric and biochemical measurements were performed. The FB was composed of adipocytes and sparse urocytes. The ultrastructure of both cells did not change considerably during this natural starvation period, except for rough endoplasmic reticulum (rER) which became more abundant in March females. In the cells, the reserve material consisted of numerous lipid droplets, glycogen rosettes, and protein granula. During overwintering, the lipid droplets diminished, and protein granula became laminated. The MTs consisted of a monolayer epithelium and individual muscle cells. The epithelial cells were attached to the basal lamina by numerous hemidesmosomes. The apical plasma membrane was differentiated into numerous microvilli, many of them containing mitochondria. Nuclei were surrounded by an abundant rER. There were numerous spherites in the perinuclear part of the cells. The basal plasma membrane formed infoldings with mitochondria in between. Nuclei were located either in the basal or in the central part of the cells. During overwintering, spherites were gradually exploited, and autophagic structures appeared: autophagosomes, autolysosomes, and residual bodies. There were no statistical differences between the sexes in any measured biometric and biochemical variables in the same time frames. The energy-supplying lipids and glycogen, and spherite stores were gradually spent during overwintering. In March, the augmented rER signified the intensification of synthetic processes prior to the epigean ecophase.
    Keywords adipocytes ; droplets ; epithelial cells ; epithelium ; fat body ; females ; glycogen ; habitats ; light microscopy ; lipids ; Malpighian tubules ; microvilli ; mitochondria ; moths ; myocytes ; overwintering ; plasma membrane ; rough endoplasmic reticulum ; starvation ; transmission electron microscopy ; ultrastructure
    Language English
    Dates of publication 2017-11
    Size p. 2189-2199.
    Publishing place Springer Vienna
    Document type Article
    ZDB-ID 123809-7
    ISSN 1615-6102 ; 0033-183X
    ISSN (online) 1615-6102
    ISSN 0033-183X
    DOI 10.1007/s00709-017-1110-3
    Database NAL-Catalogue (AGRICOLA)

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