13 research outputs found

    Cytosolic aggregation of mitochondrial proteins disrupts cellular homeostasis by stimulating the aggregation of other proteins.

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    Mitochondria are organelles with their own genomes, but they rely on the import of nuclear-encoded proteins that are translated by cytosolic ribosomes. Therefore, it is important to understand whether failures in the mitochondrial uptake of these nuclear-encoded proteins can cause proteotoxic stress and identify response mechanisms that may counteract it. Here, we report that upon impairments in mitochondrial protein import, high-risk precursor and immature forms of mitochondrial proteins form aberrant deposits in the cytosol. These deposits then cause further cytosolic accumulation and consequently aggregation of other mitochondrial proteins and disease-related proteins, including α-synuclein and amyloid β. This aggregation triggers a cytosolic protein homeostasis imbalance that is accompanied by specific molecular chaperone responses at both the transcriptomic and protein levels. Altogether, our results provide evidence that mitochondrial dysfunction, specifically protein import defects, contributes to impairments in protein homeostasis, thus revealing a possible molecular mechanism by which mitochondria are involved in neurodegenerative diseases

    Middle Pleistocene fauna and palaeoenvironment in the south of Eastern Europe: A case study of the Medzhybizh 1 locality (MIS 11, Ukraine)

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    The Middle Pleistocene was a period of dynamic changes in Europe. During MIS 11, a number of modern mammal taxa appeared and environmental conditions remained warm and favourable for a relatively long time. The Medzhybizh 1 locality of Ukraine dated to this very period comprises alluvial deposits with rich animal remains, which allow not only to reconstruct the fauna composition, but also to highlight the environmental conditions that dominated at this locality. A revision of the fauna of Medzhybizh 1 locality based on remains of all vertebrate groups revealed a taxonomically diverse fish community (16 species of 11 genera) dominated by cyprinids common for lacustrine or riverine assemblages. Amphibians are represented by 11 species, while the number of reptile and bird remains are less significant. Mammals are the most represented group at the locality, including small mammals (30 species), carnivorans (2 species), and ungulates (5 taxa), the latter dominated by C. elaphus. The taxonomic composition of terrestrial groups indicates temperate climate with boreal-type forests and meadows similar to cold steppe, as well as low wet areas and riparian habitats inhabited by amphibians, reptiles, insectivores, beavers, and various voles. The fish assemblage indicates a partially overgrown but well-aerated water body (lake or slow-flowing river) with sandy-silty bottom. Lithic artefacts found at the Medzhybizh 1 locality contribute to a better understanding of relationships between ancient hominins and faunas during the Middle Pleistocene of Eastern Europe.Archaeological field works at Medzhybizh were supported by the NASU state research projects 0105U001383 (2005–2009), 0109U008921 (2010–2014) and partly funded by the State Fund of Fundamental Research of Ukraine grant 0118U001457 (F77/50–2018). This research was also supported by the grant 0201/2048/18 ‘Life and death of extinct rhino (Stephanorhinus sp.) from Western Poland: a multi-proxy palaeoenvironmental approach’ financed from the funds of the National Science Centre, Poland. JvdM received support from the Spanish Ministerio de Ciencia, Inovación y Universidades (current grant numbers PGC2018-093925-B-C31 and PGC2018-095489-B-I00).Peer reviewe

    Browsers, grazers or mix-feeders? Study of the diet of extinct Pleistocene Eurasian forest rhinoceros Stephanorhinus kirchbergensis (J¨ager, 1839) and woolly rhinoceros Coelodonta antiquitatis (Blumenbach, 1799)

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    The wooly rhinoceros (Coelodonta antiquitatis) and forest rhinoceros (Stephanorhinus kirchbergensis) were prominent representatives of the Middle and Late Pleistocene glacial and interglacial faunas of Eurasia. Their diet has traditionally been inferred on functional morphology of the dentition and skull. In rare cases, food remains are preserved in the fossas of the teeth or as gut content. New approaches to infer diet include the study of isotopes and mesowear. Here we apply all four methods to infer the diet of these emblematic rhinoceros’ species and compare the food actually taken with the food available, as indicated by independent botanical data from the localities where the rhinoceros’ fossils were found: Gorz´ow Wielkopolski (Eemian) and Starunia (Middle Vistulian) as well as analysis of literature data. We also made inferences on the season of death of these individuals. Our results indicate that the woolly rhino in both Europe and Asia (Siberia) was mainly a grazer, although at different times of the year and depending on the region its diet was also supplemented by leaves of shrubs and trees. According to the results of isotope studies, there were important individual variations. The data show a clear seasonal variation in the isotope composition of this rhino’s diet. In contrast, Stephanorhinus kirchbergensis was a browser, though its diet included low-growing vegetation. Its habitat consisted of various types of forests, from riparian to deciduous and mixed forests, and open areas. The diet of this species consisted of selected items of vegetation, also including plants growing near both flowing and standing waters. The food remains from the fossae of the teeth indicated flexible browsing, confirming the previous interpretations based on functional morphology and stable isotopes. Long-term data from mesowear and microwear across a wider range of S. kirchbergensis fossils indicate a more mixed diet with a browsing component. The different diets of both of rhinoceros reflect not only the different habitats, but also climate changes that occurred during the Late Pleistocene

    Diversity of muskox Ovibos moschatus (Zimmerman, 1780) (Bovidae, Mammalia) in time and space based on cranial morphometry

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    Muskox Ovibos moschatus is a Pleistocene relic, which has survived only in North America and Greenland. During the Pleistocene, it was widely distributed in Eurasia and North America. To evaluate its morphological variability through time and space, we conducted an extensive morphometric study of 217 Praeovibos and Ovibos skull remains. The analyses showed that the skulls grew progressively wider from Praeovibos sp. to the Pleistocene O. moschatus, while from the Pleistocene to the recent O. moschatus, the facial regions of the skull turned narrower and shorter. We also noticed significant geographic differences between the various Pleistocene Ovibos crania. Siberian skulls were usually larger than those from Western and Central Europe. Eastern Europeanmuskoxen also exceeded in size those from the other regions of Europe. The large size of Late Pleistocene muskoxen from regions located in more continental climatic regimes was probably associated with the presence of more suitable food resources in steppe-tundra settings. Consistently, radiocarbon-dated records of this species are more numerous in colder periods, when the steppe-tundra was widely spread, and less abundant in warmer periods

    A skeleton of peat-trapped forest rhinoceros Stephanorhinus kirchbergensis (Jäger, 1839) from Gorzów Wielkopolski, Northwestern Poland: a record of life and death of the Eemian large mammals

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    We present a description of an almost complete skeleton of the forest rhino (Stephanorhinus kirchbergensis) found near Gorzów Wielkopolski (Northwest Poland) in its geological and palaeoenvironmental context. While finds of bones and teeth are common, the importance of this find resides in, that it is the most complete specimen of this species, almost perfectly preserved in a well-studied and dated stratigraphic and sedimentological context, along with other fossil fauna and flora. The OSL dates of glaciofluvial sediments sandwiching skeleton-bearing horizons indicate a Middle Eemian age of the Pleistocene paleolake land. This warm climate is also indicated by the results of sedimentological, geochemical, paleobotanical, and isotopic analyses. The rhino skeleton was deposited in a shallow area near the lake’s littoral zone. Bite marks of a large predator (cave hyena) were recognized on the rhino’s pelvis, which, due to their location, were probably created post-mortem. With an estimated height of 1.82 m at the withers, this was a large adult Stephanorhinus kirchbergensis. The results of osteometric analyses indicate that we are dealing with one of the largest known individuals of this species. Although it suffered from a pathologically deformed spine, the individual died at a relatively old age.Peer reviewe

    Proceedings of the 48 Speleological Symposium : Kletno, 16-19.10.2014

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    Pro-Healthy Diet Properties and Its Determinants among Aging Masters Athletes

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    Qualitative dietary assessments are not common in aging athletes. Therefore, this study aimed to evaluate diet quality and its determinants among aging masters athletes. Eighty-six participants of the 8th World Masters Indoor Athletics Championships were enrolled in the study (age range 36–65 years). Three subgroups were distinguished to represent countries with different eating habits. Body composition was measured by bioelectrical impedance. Eating habits and diet quality were assessed using the Dietary Habits and Nutrition Beliefs Questionnaire (KomPAN®, Warszawa, Poland), and the Pro-healthy Diet Index (pHDI-10). Dietary quality determinants were identified by a multiple regression model conducted for each subgroup separately (Great Britain, France, and Poland). The results showed that none of the subgroups adhered to the reference intake of products with beneficial health outcomes. This was particularly noticeable in the insufficient consumption of whole grain products, dairy, and fish. The fish and vegetables consumption frequency significantly differentiated the eating habits of the studied groups. Diet quality determinants varied depending on the group. However, in each of them, fruit consumption was one of the components of a good-quality diet. The obtained results can be used by institutions providing health education among the elderly to develop an appropriate strategy aimed at changing inappropriate eating habits

    Evaluation of ACL Graft Remodeling and Prediction of Graft Insufficiency in Sequenced MRI—Two-Year Follow-Up

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    Background: Postoperative magnetic resonance imaging (MRI) evaluation of anterior cruciate ligament (ACL) graft maturity is a useful and practical tool that allows for assessment of graft status and remodeling stage. The purpose of this study was to evaluate and compare previously described methods of graft evaluation in MRI. We identify factors influencing the maturation and correlating graft appearance in MRI with indirect symptoms of graft insufficiency to identify patients at risk. Methods: Retrospective evaluation was performed in 44 patients who received bone patellar tendon bone (BPTB) ACL reconstruction with nine consecutive postoperative MRIs at 2, 6, 12, 18, 24, 36, 48, 72, and 96 weeks. Graft status was evaluated using signal-to-noise quotient (SNQ) methods in both sagittal and axial planes. We also assessed the homogeneity of the graft by standard deviation (SD) of signal intensity. SNQ was correlated with patient’s age, sex, postoperative weight-bearing, as well as indirect signs of graft insufficiency by MRI including graft appearance, posterior cruciate ligament (PCL) buckling, and measurement of anterior tibia subluxation. Results: We observed that the results of modelling SNQs from both sagittal and axial planes were similar. For both SNQs, the change over weeks quotient was nonlinear where the clinical parameter increased at week 36 and subsequently decreased. The SNQ at week 96 does not reach the levels from week 2. We observed that the model incorporating SNQ and relative SD (rSD) in the sagittal plane predicted the tibia anterior subluxation proportions better than the model with clinical parameters measured in the axial plane. Our results demonstrate that greater SD is associated with less graft homogeneity, which could indicate that this model is a good predictor of graft insufficiency. In addition, the proportion of PCL buckling increased over the course of the study. Conclusions: MRI graft evaluation is very useful for assessing graft ligamentization stage and to predict graft insufficiency
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