36 research outputs found

    Lipoxygenases and Poly(ADP-Ribose) Polymerase in Amyloid Beta Cytotoxicity

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    The 12/15-lipoxygenase(s) (LOX), poly(ADP-ribose) polymerase (PARP-1) activity and mitochondrial apoptosis inducing factor (AIF) protein in the amyloid β (Aβ) toxicity were investigated in PC12 cells that express either wild-type (APPwt) or double Swedish mutation (APPsw) forms of human Aβ precursor protein. Different levels of Aβ secretion and free radicals formation characterize these cells. The results demonstrated a relationship between the Aβ levels and LOX protein expression and activity. High Aβ concentration in APPsw cells correlated with a significant increase in free radicals and LOX activation, which leads to translocation of p65/NF-κB into the nucleus. An increase in AIF expression in mitochondria was observed concurrently with inhibition of PARP-1 activity in the nuclear fraction of APPsw cells. We suggested that AIF accumulation in mitochondria may be involved in adaptive/protective processes. However, inhibition of PARP-1 may be responsible for the disturbances in transcription and DNA repair as well as the degeneration of APP cells. Under conditions of increased nitrosative stress, evoked by the nitric oxide donor, sodium nitroprusside (SNP, 0.5 mM), 70–80% of all cells types died after 24 h, significantly more in APPsw cells. There was no further significant change in mitochondrial AIF level and PARP-1 activity compared to corresponding non-treated cells. Only one exception was observed in PC12 control, where SNP significantly inhibits PARP-1 activity. Moreover, SNP significantly activated gene expression for 12/15-LOX in all types of investigated cells. Inhibitors of all LOX isoforms and specific inhibitor of 12-LOX enhanced the survival of cells that were subjected to SNP. We conclude that the LOX pathways may play a role in Aβ toxicity and in nitrosative-stress-induced cell death and that inhibition of these pathways offers novel protective strategies

    Aging-Related Cellular, Structural and Functional Changes in the Lymph Nodes: A Significant Component of Immunosenescence? An Overview

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    Aging affects all tissues and organs. Aging of the immune system results in the severe disruption of its functions, leading to an increased susceptibility to infections, an increase in autoimmune disorders and cancer incidence, and a decreased response to vaccines. Lymph nodes are precisely organized structures of the peripheral lymphoid organs and are the key sites coordinating innate and long-term adaptive immune responses to external antigens and vaccines. They are also involved in immune tolerance. The aging of lymph nodes results in decreased cell transport to and within the nodes, a disturbance in the structure and organization of nodal zones, incorrect location of individual immune cell types and impaired intercellular interactions, as well as changes in the production of adequate amounts of chemokines and cytokines necessary for immune cell proliferation, survival and function, impaired naïve T- and B-cell homeostasis, and a diminished long-term humoral response. Understanding the causes of these stromal and lymphoid microenvironment changes in the lymph nodes that cause the aging-related dysfunction of the immune system can help to improve long-term immune responses and the effectiveness of vaccines in the elderly

    Vascular plants of the Maly Borek Nature Reserve in the Augustow Forest (NE Poland)

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    During the survey of the Mały Borek nature reserve (Augustów Forest, NE Poland) 236 species of vascular plants were recorded, including 10 plant species red-listed in Poland and 19 species protected under the Polish law. The most valuable species were sedges typical of the boreal coniferous forests: Carex vaginata, C. globularis and C. loliacea. The presence of neophytes was very limited (1,3% of the flora) in the area studied. The principal aim of the establishment of the reserve was the conservation of old-growth coniferous forests with long ecological continuity. Since the reserve studied consists mainly of old-growth coniferous forests, the number of species regarded as ancient forest indicators is lower (54 species) than in the well-preserved reserves with deciduous stands in north-east Poland, but still rather high. The most valuable, threatened species are bound to wetland forests that are presently disturbed due to drainage. Restoration of the former hydrological conditions is essential for the preservation of the vascular plants in the reserve
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