Integrated Radiolaria, Benthic Foraminifera And Conodont Biochronology Of The Pelagic Permian Blocks/Tectonic Slices And Geochemistry Of Associated Volcanic Rocks From The Mersin Melange, Southern Turkey: Implications For The Permian Evolution Of The Northern Neotethys

Blocks and tectonic slices within the Mersin Melange (southern Turkey), which are of Northern Neotethyan origin (Izmir-Ankara-Erzincan Ocean (IAE)), were studied in detail by using radiolarian, conodont, and foraminiferal assemblages on six different stratigraphic sections with well-preserved Permian succesions. The basal part of the Permian sequence, composed of alternating chert and mudstone with basic volcanics, is assigned to the late Asselian (Early Permian) based on radiolarians. The next basaltic interval in the sequence is dated as Kungurian. The highly alkaline basic volcanics in the sequence are extremely enriched, similar to kimberlitic/lamprophyric magmas generated at continental intraplate settings. Trace element systematics suggest that these lavas were generated in a continental margin involving a metasomatized subcontinental lithospheric mantle source (SCLM). The middle part of the Permian sequences, dated by benthic foraminifera and conodont assemblages, includes detrital limestones with chert interlayers and neptunian dykes of middle Wordian to earliest Wuchiapingian age. Higher in the sequence, detrital limestones are overlain by alternating chert and mudstone with intermittent microbrecciated beds of early Wuchiapingian to middle Changhsingian (Late Permian) age based on the radiolarians. A large negative shift at the base of the Lopingian at the upper part of section is correlated to negative shifts at the Guadalupian/Lopingian boundary associated with the end-Guadalupian mass extinction event. All these findings indicate that a continental rift system associated with a possible mantle plume existed during the late Early to Late Permian period. This event was responsible for the rupturing of the northern Gondwanan margin related to the opening of the IAE Ocean. When the deep basinal features of the Early Permian volcano-sedimentary sequence are considered, the proto IAE oceanic crust formed possibly before the end of the Permian. This, in turn, suggests that the opening of the IAE Ocean dates back to as early as the Permian.WoSScopu

The investigation of immunomodulatory effects of adipose tissue mesenchymal stem cell educated macrophages on the CD4 T cells

WOS: 000480826300015PubMed ID: 31072631Mesenchymal stem cells (MSCs) are strong immunomodulatory cells investigated in numerous clinical studies on fatal pathologies, such as graft versus host disease and autoimmune diseases; e.g., systemic lupus erythematosus, Crohn's disease, and ulcerative colitis. Macrophages are one of the critical cells linking the innate and adaptive immune system, and it has been shown that MSCs can differentiate between pro-inflammatory M1 phenotype and anti-inflammatory M2 phenotype of macrophages. However, it has not yet been fully clarified whether these differentiated macrophages are functional. In this study, we compared the immunomodulatory effects on the CD4 T cells of M1, M2a and M2c macrophages with the macrophages that directly and indirectly cultured with MSCs. We analyzed the changes in CD14, CD64, CD80, CD163 and CD200R expression to evaluate macrophage phenotypes, and the changes in CD4, IFN-g, IL-4, IL-17a and FoxP3 expression to evaluate T helper subsets using the FACS method. The changes in IL-1b, IL-4, IL-10, IL-12p70, IL-17a and IFN-g in the media supernatants were analyzed using the Luminex method. We also performed WST-1 and Caspase-3 ELISA analyses to observe the proliferation and apoptosis status of the T cells. MSCs were found to differentiate macrophages into a distinctive phenotype, which was close to the M2c phenotype, but was not considered as an M2c cell due to the low expression of CD163, a characteristic marker for M2c. While MEM-D, MEM-ID and MSCs showed similar inhibitory effects on the Th2 and Th17 cells, the most significant increase in Treg cell frequencies was seen in MEM-D cells. Macrophages can alter their phenotypes and functions according to the stimuli from the environment. The fact that macrophages educated with MSCs suppressed the production of all the cytokines we evaluated even after the removal of MSCs suggests that these cells may be differentiated by MSCs into a suppressive macrophage subgroup. However, the Treg cell activation caused by direct interactions between MSCs and macrophage cells may be the most prominent observation of this study compared to previous work. As a result, according to our data, the interactions between MSCs and macrophages may lead to differentiation of macrophage cells into an immunosuppressive phenotype, and these macrophages may suppress the T lymphocyte subgroups at least as effectively as MSCs. However, our data obtained from in vitro experiments should be supported by future in vivo studies.Scientific and Technological Research Council of Turkey (TUBITAK)2Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [216 S 761]The Scientific and Technological Research Council of Turkey (TUBITAK)2 supported the project for this study, whose reference number is 216 S 761