Two transport processes in a single protein : molecular mechanisms underlying glutamate transporter function

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Исследование прочностных характеристик ремонтных конструкций трубопроводов

Моделирование трубопроводов с дефектами и ремонтных конструкций в среде ANSYS. Исследование прочностных характеристик ремонтных конструкций.Modeling of pipelines with defects and repair structures in ANSYS. Evaluation of strength characteristics of sleeve joints

Clinical Significance of Sentinel Lymph Node Detection in Patients with Invasive Cervical Cancer

The clinical significance of determining sentinel lymph nodes (SLN) in patients with invasive cervical cancer was studied. From 2013 to 2014, 30 cervical cancer patients (T1a1NxM0-T1b1NxM0) were treated at the Gynecological Oncology Department of the Cancer Research Institute. The day before surgery, four submucosal injections of 99mTc Al2O3 at a total dose of 80 MBq were made in each quadrant around the cervical tumor. Patients were submitted to preoperative lymphoscintigraphy and intraoperative SLN detection. The feasibility of preserving the reproductive potential in patients after radical abdominal trachelectomy was assessed. The 3-year, overall, disease-free and metastasis-free survival rates were analyzed. Thirty-four SLNs were detected by single-photon emission computed tomography (SPECT) and 42 SLNs were identified by intraoperative gamma probe. The sensitivity in detecting SLNs was 100% for intraoperative SLN identification and 80% for SPECT image. The reproductive potential was preserved in 86% of patients. The 3-year overall and metastases-free survival rates were 100%. Recurrence occurred in 8.6% of cases

A β-Lactam Antibiotic Dampens Excitotoxic Inflammatory CNS Damage in a Mouse Model of Multiple Sclerosis

In multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE), impairment of glial “Excitatory Amino Acid Transporters” (EAATs) together with an excess glutamate-release by invading immune cells causes excitotoxic damage of the central nervous system (CNS). In order to identify pathways to dampen excitotoxic inflammatory CNS damage, we assessed the effects of a β-lactam antibiotic, ceftriaxone, reported to enhance expression of glial EAAT2, in “Myelin Oligodendrocyte Glycoprotein” (MOG)-induced EAE. Ceftriaxone profoundly ameliorated the clinical course of murine MOG-induced EAE both under preventive and therapeutic regimens. However, ceftriaxone had impact neither on EAAT2 protein expression levels in several brain areas, nor on the radioactive glutamate uptake capacity in a mixed primary glial cell-culture and the glutamate-induced uptake currents in a mammalian cell line mediated by EAAT2. Moreover, the clinical effect of ceftriaxone was preserved in the presence of the EAAT2-specific transport inhibitor, dihydrokainate, while dihydrokainate alone caused an aggravated EAE course. This demonstrates the need for sufficient glial glutamate uptake upon an excitotoxic autoimmune inflammatory challenge of the CNS and a molecular target of ceftriaxone other than the glutamate transporter. Ceftriaxone treatment indirectly hampered T cell proliferation and proinflammatory INFγ and IL17 secretion through modulation of myelin-antigen presentation by antigen-presenting cells (APCs) e.g. dendritic cells (DCs) and reduced T cell migration into the CNS in vivo. Taken together, we demonstrate, that a β-lactam antibiotic attenuates disease course and severity in a model of autoimmune CNS inflammation. The mechanisms are reduction of T cell activation by modulation of cellular antigen-presentation and impairment of antigen-specific T cell migration into the CNS rather than or modulation of central glutamate homeostasis

Selenocysteine is transported by EAATs 1–3.

<p><b>A)</b> Representative recordings (upper panel) and averaged normalized transport currents (lower panel) measured at −60 mV as a function of the L-selenocysteine concentration in EAAT3 expressing oocytes (n = 6). Data are presented as the mean and Std. dev. of the mean and fit with the Hill equation to estimate the Km for transport. <b>B)</b> Comparison of the maximal transport currents at −60 mV for L-selenocysteine and L-cysteine by EAAT1 (n>3), EAAT2 (n>5) or EAAT3 (n>10) normalized to the maximal currents induced by L-glutamate measured in the same oocyte. <b>C)</b> Comparison of averaged current-voltage relationships recorded from oocytes expressing EAAT3 for both 1 mM glutamate (red symbols, n = 4) and 1 mM selenocysteine (blue symbols, n = 4). Black symbols indicate the averaged current voltage relationship of the same cells in the absence of substrate (n = 4) and the solid line represents the average of water injected oocytes in the presence of 1 mM glutamate (n = 5).</p

pH affects glutamate inhibition of cysteine transport.

<p>Glutamate inhibition of cysteine uptake from oocytes expressing EAAT3 at three different cysteine concentrations: 30 µM (circles), 300 µM (triangles) and 1 mM (squares) at pH 6.9 (<b>A</b>) and pH 8.5 (<b>B</b>).</p

Transport of substrates in cells expressing EAAT2 or EAAT3 differentially affects intracellular pH.

<p>Representative fluorescence recordings from HEK293 cells expressing EAAT2 (<b>A</b>) or EAAT3 (<b>B</b>) in response to short applications of different concentrations of L-cysteine, L-glutamate or L-selenocysteine. The magnitude of maximal steady state slopes (<b>A</b> and <b>B</b>) are plotted in bar graphs below each trace, normalized to the glutamate slope magnitude. <b>C)</b> Representative trace of the effect on cysteine induced mEGFPpH fluorescence changes in EAAT3 expressing HEK293 cells with (left) or without (right) 100 µM TBOA. The Y-axis units for traces represent the fluorescence ratio for emission at 510 nm with excitation at 485 and 405 nm (F485/F405).</p