Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

Makrofajlardaki endoplazmik retikulum stresinde katlanmamış protein yanıtı tarafından düzenlenen mirnalar

Cataloged from PDF version of thesis.Includes bibliographical reference (leaves 53-60).Thesis (M.S.): Bilkent University, Department of Molecular Biology and Genetics, İhsan Doğramacı Bilkent University, 2014.The proper functioning and the development of the cell is essential to the fitness of the multicellular organisms - any significant disturbances in cellular mechanisms can lead to a multitude of diseases or death. Among these conditions, the global rise in metabolic diseases like obesity, diabetes and atherosclerosis draw significant research interest focus. Since the prevalence of metabolic disorders in the developed and underdeveloped world is expected to increase further in next decade; understanding the contributing cellular mechanisms is vital for the development of new and effective diagnostic and therapeutic tools against this devastating disease cluster. Among the homeostatic cellular pathways important for health the Unfolded Protein Response (UPR) is highly conserved from yeast to mammals. Aside from most conserved UPR branch Inositol-requiring protein 1(IRE1), the mammalian UPR is composed of three different pathways regulated by IRE1, eukaryotic translation initiation factor 2-alpha kinase 3 (PERK), and activating transcription factor 6 (ATF6). The UPR signaling is activated in response to the accumulation of unfolded or misfolded proteins in ER that leads to endoplasmic reticulum (ER) stress. The goal of the UPR is to re-establish ER homeostasis via inhibition of further protein translation and promoting protein folding. In the case of severe or unresolved ER stress, UPR instead triggers a programmed cell death. Recent studies indicate that noncoding regulatory RNAs such as microRNAs (miRNAs) play important role in both upstream and downstream of the UPR. In this thesis, the regulation of miRNA expression by the different UPR arms are examined in macrophages under lipidinduced or lipotoxic ER stress conditions. The results of PCR array studies of RNA obtained from mouse macrophages stressed with a saturated fatty acid, palmitate (PA) , revealed multiple differentially regulated miRNAs. Among these miRNAs, significantly regulated ones were further examined for their regulation by the different arms of the UPR. Towards this end several complementary approaches were taken: First, significantly regulated microRNAs from microRNA PCR array results were analyzed. Next, macrophages were treated with palmitate after transfection with IRE1 and PERK silencer RNA (siRNA) to assess the role of UPR arms in lipid regulated miRNA regulation and the expression of relevant miRNAs was examined in treated macrophages. As an alternative method, macrophages were treated simultaneously with palmitate and specific inhibitors for IRE1’s endoribonuclease or PERK’s kinase activity. Then miRNA expressions were further examined in IRE1 knock-out mouse embryonic fibroblast (MEF) cell lines transfected with the wild type (WT) IRE or the endoribonuclease domain inactive (RD) mutant of IRE1 to verify the specific regulation of the miRNA by the IRE1’s endoribonuclease activity. As a result, upregulation of miR-2137 expression by palmitate was determined as IRE1-endoribonuclease dependent. Next, potential target mRNAs were examined by the overexpression or knock-down of miR-2137 in macrophages. One possible target mRNA was found to be inositol polyphosphate phosphatase-like 1 (Innpl1) . Aside from miR-2137, miR-33 also showed significant alteration upon PA treatment in macrophages. Since the role of miR-33 in atherosclerosis, obesity and insulin resistance is well established, its expression was studied further in RAW 264.7 macrophage cell line and bone marrow-derived primary macrophages after IRE1 and PERK knock-down with siRNA. ATP-binding cassette, sub-family A (ABC1), member 1 (ABCA1), a known target of miR-33, was investigated as down-stream target of miR-33 in PA treated macrophages, in an IRE1 dependent manner. The results of this study uncovered new UPR regulated miRNAs under lipid stress in macrophages. Excess lipid is one of the prominent causes in metabolic diseases – obesity, atherosclerosis, insulin resistance – and these UPR regulated miRNAs may explain the underlying mechanism behind this set of diseases. Furthermore, the possible gene targets for these miRNAs could be responsible for progression of such conditions. Further studies are needed to reveal the exact mechanisms that can lead to the development of novel therapeutic approaches.by Erdem Murat Terzi.M.S

In vitro Effects of Chitosan on the Survival of Listeria monocytogenes

The nonlinear robust stability theory of Georgiou and Smith (IEEE Trans. Auto. Control, 42(9):1200--1229, 1997) is generalized to the case of notions of stability with bias terms. An example from adaptive control illustrates non trivial robust stability certificates for systems which the previous unbiased theory could not establish a non-zero robust stability margin. This treatment also shows that the BIBO robust stability results for adaptive controllers in French (IEEE Trans. Auto. Control, 53(2):461--478, 2008) can be refined to show preservation of biased forms of stability under gap perturbations. In the nonlinear setting, it also is shown that, in contrast to LTI systems, the problem of minimizing nominal performance is not equivalent to maximizing the robust stability margin

The efficacy of rituximab in patients with neuromyelitis optica spectrum disorder: A real-world study from Turkey

Background Neuromyelitis optica spectrum disorders (NMOSD) are a group of antibody-mediated chronic inflammatory diseases of the central nervous system. Rituximab is a monoclonal antibody that leads to a reduction in disease activity

Inositol-requiring enzyme-1 regulates phosphoinositide signaling lipids and macrophage growth

The ER‐bound kinase/endoribonuclease (RNase), inositol‐requiring enzyme‐1 (IRE1), regulates the phylogenetically most conserved arm of the unfolded protein response (UPR). However, the complex biology and pathology regulated by mammalian IRE1 cannot be fully explained by IRE1’s one known, specific RNA target, X box‐binding protein‐1 (XBP1) or the RNA substrates of IRE1‐dependent RNA degradation (RIDD) activity. Investigating other specific substrates of IRE1 kinase and RNase activities may illuminate how it performs these diverse functions in mammalian cells. We report that macrophage IRE1 plays an unprecedented role in regulating phosphatidylinositide‐derived signaling lipid metabolites and has profound impact on the downstream signaling mediated by the mammalian target of rapamycin (mTOR). This cross‐talk between UPR and mTOR pathways occurs through the unconventional maturation of microRNA (miR) 2137 by IRE1’s RNase activity. Furthermore, phosphatidylinositol (3,4,5) phosphate (PI(3,4,5)P(3)) 5‐phosphatase‐2 (INPPL1) is a direct target of miR‐2137, which controls PI(3,4,5)P(3) levels in macrophages. The modulation of cellular PI(3,4,5)P(3)/PIP(2) ratio and anabolic mTOR signaling by the IRE1‐induced miR‐2137 demonstrates how the ER can provide a critical input into cell growth decisions

Inositol-requiring enzyme-1 regulates phosphoinositide signaling lipids and macrophage growth

The ER-bound kinase/endoribonuclease (RNase), inositol-requiring enzyme-1 (IRE1), regulates the phylogenetically most conserved arm of the unfolded protein response (UPR). However, the complex biology and pathology regulated by mammalian IRE1 cannot be fully explained by IRE1's one known, specific RNA target, X box-binding protein-1 (XBP1) or the RNA substrates of IRE1-dependent RNA degradation (RIDD) activity. Investigating other specific substrates of IRE1 kinase and RNase activities may illuminate how it performs these diverse functions in mammalian cells. We report that macrophage IRE1 plays an unprecedented role in regulating phosphatidylinositide-derived signaling lipid metabolites and has profound impact on the downstream signaling mediated by the mammalian target of rapamycin (mTOR). This cross-talk between UPR and mTOR pathways occurs through the unconventional maturation of microRNA (miR) 2137 by IRE1's RNase activity. Furthermore, phosphatidylinositol (3,4,5) phosphate (PI(3,4,5)P-3) 5-phosphatase-2 (INPPL1) is a direct target of miR-2137, which controls PI(3,4,5)P-3 levels in macrophages. The modulation of cellular PI(3,4,5)P-3/PIP2 ratio and anabolic mTOR signaling by the IRE1-induced miR-2137 demonstrates how the ER can provide a critical input into cell growth decisions