Preface [Hot Topic: Amyloidogenic Proteins and Peptides Involved in Human Neurodegenerative Diseases (Guest Editor: Brian m. Austen)]

A number of human neurodegenerative (NG) diseases are known to involve the release of unfoldedpeptides and proteins, which tend to aggregate and in the process harm neuronal cells. These diseases and theassociated aggregating proteins include Alzheimer' disease (βamyloid), Parkinson' disease (αsynuclein), CJD(PrPSc), BRI dementias (Abri and Adan), Huntington' Disease (Hungtin), spinocerebellar ataxias (ataxins), andCADASIL (Notch-3 receptor). Our understanding of the pathogenic mechanisms of these NG diseases has been derived from geneticanalyses of those subsets of NG patients showing clear familial inheritance. An examination of the sequences ofthe identified genes and reading frames has identified those proteins in parentheses above; There is considerableevidence that aggregated forms of the proteins themselves, or fragments of the proteins released by proteolysis,deposit in the brain, either intra-or extraneuronally. Indeed, sequence similarities and structural similaritiessuggest common mechanisms of aggregation of the amyloids. There is accumulating evidence that the initialsoluble aggregated forms of these peptides or proteins are toxic to neurones both in vitro, in laboratory condition,and in vivo, explaining at least in part the loss of functional neurones and ensuing cognitive or neuromusculardegeneration that give rise to abnormalities in patients. Much research has been focussed on the chemical andcellular mechanisms of aggregation and toxicity, with the aim of devising suitable therapeutics to halt theneurodegenerative process. In this special volume, invited authors elucidate structural features of the aggregationmechanisms of several amyloid systems, and relate these to cellular properties and clinical symptoms.