Proteomic analysis of cells exposed to prefibrillar aggregates of HypF-N

Abstract

Several human diseases are associated with the deposition of stable ordered protein aggregates known as amyloid fibrils. In addition, a large wealth of data shows that proteins not involved in amyloidoses, are able to form, in vitro, amyloid-like prefibrillar and fibrillar assemblies indistinguishable from those grown from proteins associated with disease. Previous studies showed that early prefibrillar aggregates of the N-terminal domain of the prokaryotic hydrogenase maturation factor HypF (HypF-N) are cytotoxic, inducing early mitochondria membrane depolarization, activation of caspase 9 and eventually cell death. To gain knowledge on the molecular basis of HypF-N aggregate cytotoxicity, we performed a differential proteomic analysis of NIH-3T3 cells exposed to HypF-N prefibrillar aggregates in comparison with control cells. Two-dimensional gel electrophoresis followed by protein identification by MALDI-TOF MS, allowed us to identify 21 proteins differentially expressed. The changes of the expression level of proteins involved in stress response (Hsp60 and 78 kDa glucose-regulated protein) and in signal transduction (Focal adhesion kinase1) appear particularly interesting as possible determinants of the cell fate. The levels of some of the differently expressed proteins were modified also in similar studies carried out on cells exposed to Aβ or α-synuclein aggregates, supporting the existence of shared features of amyloid cytotoxicity.

Unraveling amyloid toxicity pathway in NIH3T3 cells by a combined proteomic and1H‐NMR metabonomic approach

“…Reduction of gamma actin levels, resulted also after Aβ (1–42) exposure of SN56 cells (Joerchel et al, 2008). A proteomic study in NIH‐3T3 cells exposed to HypF‐N prefibrillar aggregates reveal an opposite results, specifically, an enhanced actin level in presence of amyloid aggregates (Magherini et al, 2009). However, a careful analysis of protein accession number reveals that the two studies concern different actin isoforms, the latter referring to beta isoform (Khaitlina, 2001).…”