Maysin plays a protective role against alpha-Synuclein oligomers cytotoxicity by triggering autophagy activation
FOOD AND CHEMICAL TOXICOLOGY
Authors: Leri, Manuela; Vasarri, Marzia; Palazzi, Luana; Barletta, Emanuela; Nielsen, Erik; Bucciantini, Monica; Degl'Innocenti, Donatella
Abstract
Parkinson's disease (PD) is a widespread neurodegenerative disorder characterized by the progressive loss of neurons. The accumulation of aggregated forms of the alpha-Synuclein (Syn) protein is the main cause of neumtoxicity in PD by disrupting cellular homeostasis until neuronal death. Scientific research is constantly looking for natural products as preventive agents against the progression of several neurodisorders due their safety and non-toxic nature. Neumprotective phytochemicals include Maysin (Mys), the most abundant C-glycosilflavone in corn silk. In this work, the Mys protective role against damage by Syn amyloid aggregates - oligomers and fibrils was investigated in SH-SY5Y human neuroblastoma cells obtaining novel and interesting information concerning the Mys molecular mechanism of action. Mys showed effectiveness in preventing the typical toxic events induced by Syn amyloid aggregates, i.e. oxidative stress and imbalance of intracellular calcium homeostasis. Mys exhibited a cytopmtective role, especially against Syn oligomers injury, activating an autophagic degradative process, thus playing a key role on several features of amyloid neurotoxicity. Therefore, Mys could be proposed for the first time to the scientific community as an interesting novel natural compound that might allow to develop alternative strategies to prevent the damage of Syn oligomers involved in Parkinson's disease.
The human gene for gamma S-crystallin: Alternative transcripts and expressed sequences from the first intron
MOLECULAR VISION
Authors: Wistow, G; Sardarian, L; Gan, WN; Wyatt, MK
Abstract
Purpose: gamma S-crystallins are major components of adult vertebrate lenses. Here we examine the population of gamma S transcripts in adult human lens and the structure of the human CRYGS genes. Methods: Adult lens human transcripts were obtained from NEIBANK, an Expressed Sequence Tag (EST) analysis of human eye tissues. The human CRYGS gene was isolated as a PAC clone and sequenced by direct and PCR-based methods. Results: As judged by EST frequency, gamma S is one of the most abundant transcripts in the adult human lens, ranking just behind beta B2-, alpha B- and alpha A-crystallins. EST analysis reveals two transcript sizes resulting from alternative AATAAA and ATTAAA polyadenylation signals. In addition, one cDNA clone was found to contain a novel insert sequence that disrupted the open reading frame. Gene sequencing confirmed that this insert comes from intron 1 and is part of a sequence corresponding to a cluster of unidentified human transcripts in dbEST. Human and mouse gamma S gene proximal promoter sequences were compared and showed a high degree of evolutionary conservation, including consensus binding sites for transcription factors of the maf and SOX families. Conclusions: The human CRYGS gene can give rise to at least two transcripts through alternative polyadenylation. A minor transcript results from alternative splicing into sequences in intron 1. These sequences form part of a transcription unit (Mys) expressed in several non-lens tissues. The identity and function Mys of is not yet known, however, the cryptic splicing of CRYGS could produce a defective protein product, with potentially deleterious results for the adult human lens.