The A53T alpha-synuclein mutation increases iron-dependent aggregation and toxicity

Parkinson's disease (PD) is the most common motor disorder affecting the elderly. PD is characterized by the formation of Lewy bodies and death of dopaminergic neurons. The mechanisms underlying PD are unknown, but the discoveries that mutations in alpha-synuclein can cause familial PD and that alpha-synuclein accumulates in Lewy bodies suggest that alpha-synuclein participates in the pathophysiology of PD. Using human BE-M17 neuroblastoma cells overexpressing wild-type, A53T, or A30P alpha-synuclein, we now show that iron and free radical generators, such as dopamine or hydrogen peroxide, stimulate the production of intracellular aggregates that contain alpha-synuclein and ubiquitin. The aggregates can be identified by immunocytochemistry, electron microscopy, or the histochemical stain thioflavine S. The amount of aggregation occurring in the cells is dependent on the amount of alpha-synuclein expressed and the type of alpha-synuclein expressed, with the amount of alpha-synuclein aggregation following a rank order of A53T > A30P > wild-type > untransfected. In addition to stimulating aggregate formation, alpha-synuclein also appears to induce toxicity. BE-M17 neuroblastoma cells overexpressing alpha-synuclein show up to a fourfold increase in vulnerability to toxicity induced by iron. The vulnerability follows the same rank order as for aggregation. These data raise the possibility that alpha-synuclein acts in concert with iron and dopamine to induce formation of Lewy body pathology in PD and cell death in PD

alpha-Synuclein shares physical and functional homology with 14-3-3 proteins

alpha-Synuclein has been implicated in the pathophysiology of many neurodegenerative diseases, including Parkinson's disease (PD) and Alzheimer's disease. Mutations in alpha-synuclein cause some cases of familial PD (Polymeropoulos et al., 1997; Kruger et al., 1998). In addition, many neurodegenerative diseases show accumulation of alpha-synuclein in dystrophic neurites and in Lewy bodies (Spillantini et al., 1998). Here, we show that alpha-synuclein shares physical and functional homology with 14-3-3 proteins, which are a family of ubiquitous cytoplasmic chaperones. Regions of alpha-synuclein and 14-3-3 proteins share over 40% homology. In addition, alpha-synuclein binds to 14-3-3 proteins, as well as some proteins known to associate with 14-3-3, including protein kinase C, BAD, and extracellular regulated kinase, but not Raf-1. We also show that overexpression of alpha-synuclein inhibits protein kinase C activity. The association of alpha-synuclein with BAD and inhibition of protein kinase C suggests that increased expression of alpha-synuclein could be harmful. Consistent with this hypothesis, we observed that overexpression of wild-type alpha-synuclein is toxic, and overexpression of alpha-synuclein containing the A53T or A30P mutations exhibits even greater toxicity. The activity and binding profile of alpha-synuclein suggests that it might act as a protein chaperone and that accumulation of alpha-synuclein could contribute to cell death in neurodegenerative diseases

The Grizzly, November 17, 1978

Tuition, Room And Board Fees Raised • GreaseBand Slated For January • Snow Precautions Outlined • Forum Highlights • Mail Theft In New Men\u27s • Hockey Violence Must Stop • Should Ursinus Teach Moral Values? • Acapulco: Gold • Rock\u27s Lesser-Knowns Provide Fresh Sound • Audio Corner: Purchasing audio equipment • Forum Committee • GM: Looking Good For \u2779 • A History Of Accomplishment • Bear Pack Bombs At Districts • Equestrians Riding High • Letters to the Editor: Public Apology; Grading Disputedhttps://digitalcommons.ursinus.edu/grizzlynews/1007/thumbnail.jp

Modeling key pathological features of frontotemporal dementia with C9ORF72 repeat expansion in iPSC-derived human neurons

The recently identified GGGGCC repeat expansion in the noncoding region of C9ORF72 is the most common pathogenic mutation in patients with frontotemporal dementia (FTD) or amyotrophic lateral sclerosis (ALS). We generated a human neuronal model and investigated the pathological phenotypes of human neurons containing GGGGCC repeat expansions. Skin biopsies were obtained from two subjects who had \u3e 1,000 GGGGCC repeats in C9ORF72 and their respective fibroblasts were used to generate multiple induced pluripotent stem cell (iPSC) lines. After extensive characterization, two iPSC lines from each subject were selected, differentiated into postmitotic neurons, and compared with control neurons to identify disease-relevant phenotypes. Expanded GGGGCC repeats exhibit instability during reprogramming and neuronal differentiation of iPSCs. RNA foci containing GGGGCC repeats were present in some iPSCs, iPSC-derived human neurons and primary fibroblasts. The percentage of cells with foci and the number of foci per cell appeared to be determined not simply by repeat length but also by other factors. These RNA foci do not seem to sequester several major RNA-binding proteins. Moreover, repeat-associated non-ATG (RAN) translation products were detected in human neurons with GGGGCC repeat expansions and these neurons showed significantly elevated p62 levels and increased sensitivity to cellular stress induced by autophagy inhibitors. Our findings demonstrate that key neuropathological features of FTD/ALS with GGGGCC repeat expansions can be recapitulated in iPSC-derived human neurons and also suggest that compromised autophagy function may represent a novel underlying pathogenic mechanism

Pennsylvania Folklife Vol. 32, No. 4

• Frakturs • Apple Head Dolls are Unique • Tableware and Dutch Folklore • The Pipemaker • Wheat Weaving • Beekeeping: Past and Present • The Pennsylvania Longrifle • Festival Focus • Folk Festival Programs • Quilts • The Country Butcher • Stained Glass • Metal Casting in Sand • Is This Pure Leather? • The Horse and Carriage • Marquetry, Parquetry and Intarsia • Pennsylvania Dutch Cookinghttps://digitalcommons.ursinus.edu/pafolklifemag/1100/thumbnail.jp

Dose intensity and efficacy of the combination of everolimus and exemestane (EVE/EXE) in a real-world population of hormone receptor-positive (ER+/PgR+), HER2-negative advanced breast cancer (ABC) patients: a multicenter Italian experience

Aim: This retrospective analysis focused on the effect of treatment with EVE/EXE in a real-world population outside of clinical trials. We examined the efficacy of this combination in terms of PFS and RR related to dose intensity (5 mg daily versus 10 mg daily) and tolerability. Methods: 163 HER2-negative ER+/PgR+ ABC patients, treated with EVE/EXE from May 2011 to March 2016, were included in the analysis. The primary endpoints were the correlation between the daily dose and RR and PFS, as well as an evaluation of the tolerability of the combination. Secondary endpoints were RR, PFS, and OS according to the line of treatment. Patients were classified into three different groups, each with a different dose intensity of everolimus (A, B, C). Results: RR was 29.8% (A), 27.8% (B) (p = 0.953), and not evaluable (C). PFS was 9 months (95% CI 7–11) (A), 10 months (95% CI 9–11) (B), and 5 months (95% CI 2–8) (C), p = 0.956. OS was 38 months (95% CI 24–38) (A), median not reached (B), and 13 months (95% CI 10–25) (C), p = 0.002. Adverse events were stomatitis 57.7% (11.0% grade 3–4), asthenia 46.0% (6.1% grade 3–4), hypercholesterolemia 46.0% (0.6% grade 3–4), and hyperglycemia 35.6% (5.5% grade 3–4). The main reason for discontinuation/interruption was grade 2–3 stomatitis. Conclusions: No correlation was found between dose intensity (5 vs. 10 mg labeled dose) and efficacy in terms of RR and PFS. The tolerability of the higher dose was poor in our experience, although this had no impact on efficacy