Glycation potentiates α-synuclein-associated neurodegeneration in synucleinopathies

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Effect of dietary palm oil on growth and carcass composition of Heterobranchus longifilis fingerlings

This study investigated the effects of dietary palm oil (PO) on growth performance and carcass composition of Heterobranchus longifilis with the goal of replacing dietary fish oil with palm oil. In this study triplicate groups of H. longifilis fingerlings were fed the experimental diets for 8 weeks. Five isonitrogenous (45% crude protein), isoenergetic (20 KJg-1) experimental diets were made containing either 6.0% FO and 0% PO, 4.5% FO and 1.5% PO; 3.0% FO and 3.0% PO; 1.5% FO and 4.5% PO; or 0% FO and 6.0% PO using soybean and fish meal as the protein source. Dietary palm oil had no significant effect on growth rate or feed conversion ratio. Similarly, No significant differences were observed between dietary treatments for moisture, protein and ash content in H. longifilis fingerlings. However, fillet saturated, monounsaturated fatty acids and liver lipid deposition were significantly (P0.05) higher in fish fed 6.0% PO diet. This study suggests that the replacement of cod liver oil by palm oil as lipid supplement in the diet permitted a clear improvement of growth and FCR of H. longifilis. This indicates that PO can effectively replace FO in the diet of the fish without compromising fish growth and feed efficiency

Overexpression of synphilin-1 promotes clearance of soluble and misfolded alpha-synuclein without restoring the motor phenotype in aged A30P transgenic mice.

Lewy bodies and neurites are the pathological hallmark of Parkinson's disease. These structures are composed of fibrillized and ubiquitinated alpha-synuclein suggesting that impaired protein clearance is an important event in aggregate formation. The A30P mutation is known for its fast oligomerization, but slow fibrillization rate. Despite its toxicity to neurons, mechanisms involved in either clearance or conversion of A30P alpha-synuclein from its soluble state into insoluble fibrils and their effects in vivo are poorly understood. Synphilin-1 is present in Lewy bodies, interacting with alpha-synuclein in vivo and in vitro and promotes its sequestration into aggresomes, which are thought to act as cytoprotective agents facilitating protein degradation. We therefore crossed animals overexpressing A30P alpha-synuclein with synphilin-1 transgenic mice to analyze its impact on aggregation, protein clearance and phenotype progression. We observed that co-expression of synphilin-1 mildly delayed the motor phenotype caused by A30P alpha-synuclein. Additionally, the presence of N- and C-terminal truncated alpha-synuclein species and fibrils were strongly reduced in double-transgenic mice when compared with single-transgenic A30P mice. Insolubility of mutant A30P and formation of aggresomes was still detectable in aged double-transgenic mice, paralleled by an increase of ubiquitinated proteins and high autophagic activity. Hence, this study supports the notion that co-expression of synphilin-1 promotes formation of autophagic-susceptible aggresomes and consecutively the degradation of human A30P alpha-synuclein. Notably, although synphilin-1 overexpression significantly reduced formation of fibrils and astrogliosis in aged animals, a similar phenotype is present in single- and double-transgenic mice suggesting additional neurotoxic processes in disease progression

Glycation potentiates α-synuclein-associated neurodegeneration in synucleinopathies

α-Synuclein misfolding and aggregation is a hallmark in Parkinson's disease and in several other neurodegenerative diseases known as synucleinopathies. The toxic properties of α-synuclein are conserved from yeast to man, but the precise underpinnings of the cellular pathologies associated are still elusive, complicating the development of effective therapeutic strategies. Combining molecular genetics with target-based approaches, we established that glycation, an unavoidable age-associated post-translational modification, enhanced α-synuclein toxicity in vitro and in vivo, in Drosophila and in mice. Glycation affected primarily the N-terminal region of α-synuclein, reducing membrane binding, impaired the clearance of α-synuclein, and promoted the accumulation of toxic oligomers that impaired neuronal synaptic transmission. Strikingly, using glycation inhibitors, we demonstrated that normal clearance of α-synuclein was re-established, aggregation was reduced, and motor phenotypes in Drosophila were alleviated. Altogether, our study demonstrates glycation constitutes a novel drug target that can be explored in synucleinopathies as well as in other neurodegenerative conditions.Authors were supported by: H.V.M. (Fundac¸a˜o para a Cieˆncia e Tecnologia (FCT), Portugal SFRH/BPD/64702/ 2009 and SFRH/BPD/109347/2015; EU FP7 project MEFOPA), L.M.A.O (FCT - SFRH/BD/23604/2005; CIRM-BMFB joint grant, 315050 AZ0101-31P6855), R.M.O. and T.S. (FCT SFRH/BPD/41416/2007; SFRH/ BPD/31209/2006); W.X. (Deutsche Forschungsgemeinschaft, SFB539/A3); C.B. and F.G. (Parkinson’s UK and the Medical Research Council, UK). S.E. is supported by Israel Academy of Sciences, Rappaport Family Institute for Research in the Medical Sciences, The Allen and Jewel Prince Center for Neurodegenerative Disorders of the Brain. T.F.O. (EMBO Installation Grant; Marie Curie IRG, Neurofold; DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain; I.C.M. (FCT SFRH/BPD/74287/2010; Investigador FCT IF/00772/ 2013). This work was supported by: FCT PTDC/SAUNEU/ 105215/2008, PTDC/QUI/73430/2006, PTDC/SAUENB/ 117013/2010, PTDC/NEU-OSD/5644/2014; EU FP7 project MEFOPA; CIRM-BMFB joint grant (315050 AZ0101-31P6855); Max Planck Society; and European Union (NEURASYNC PITNGA-2009-238316).info:eu-repo/semantics/publishedVersio