Stress Conditions Increase Vimentin Cleavage by Omi/HtrA2 Protease in Human Primary Neurons and Differentiated Neuroblastoma Cells

Abstract

Dysfunctional Omi/HtrA2, a mitochondrial serine protease, has been implicated in various neurodegenerative disorders. Despite the wealth of evidence on the roles of Omi/HtrA2 in apoptosis, little is known about its cytosolic targets, the cleavage of which could account for the observed morphological changes such as cytoskeletal reorganizations in axons. By proteomic analysis, vimentin was identified as a substrate for Omi/HtrA2 and we have reported increased Omi/HtrA2 protease activity in Alzheimer disease (AD) brain. Here, we investigated a possible link between Omi/HtrA2 and vimentin cleavage, and consequence of this cleavage on mitochondrial distribution in neurons. In vitro protease assays showed vimentin to be cleaved by Omi/HtrA2 protease, and proximity ligation assay demonstrated an increased interaction between Omi/HtrA2 and vimentin in human primary neurons upon stress stimuli. Using differentiated neuroblastoma SH-SY5Y cells, we showed that Omi/HtrA2 under several different stress conditions induces cleavage of vimentin in wild-type as well as SH-SY5Y cells transfected with amyloid precursor protein with the Alzheimer disease-associated Swedish mutation. After stress treatment, inhibition of Omi/HtrA2 protease activity by the Omi/HtrA2 specific inhibitor, Ucf-101, reduced the cleavage of vimentin in wild-type cells. Following altered vimentin filaments integrity by stress stimuli, mitochondria was redistributed in differentiated SH-SY5Y cells and human primary neurons. In summary, the findings outlined in this paper suggest a role of Omi/HtrA2 in modulation of vimentin filamentous structure in neurons. Our results provide important findings for understanding the biological role of Omi/HtrA2 activity during stress conditions, and give knowledge of interplay between Omi/HtrA2 and vimentin which might affect mitochondrial distribution in neurons.

Acute administration of ucf-101 ameliorates the locomotor impairments induced by a traumatic spinal cord injury

“…In our analyses, ucf-101 treatment increased the number of neurons surviving from programmed cell death, particularly in sections caudally far away from the initial damage, where tissue did not show signs of white matter alteration. Present experiments in neuro-2a neuroblastoma cell line as well as previous ones in other neuronal related cell lines(Jiang et al, 2014;Lucotte et al, 2014) confirm that ucf-101 cytoprotects neuronal cells from apoptotic stimuli.…”

Fibroblasts as a practical alternative to mesenchymal stem cells

“…Vimentin, is major structural component of the intermediate filaments in many cell types, is shown to play an important role in vital mechanical and biological functions such as cell contractility, migration, stiffness, stiffening, and proliferation [ 74 , 75 ]. One disadvantage of this marker is that it is also found on endothelial cells of capillaries that often locate very close to fibroblasts, additionally, it is found on neurons [ 76 ]. Another marker of fibroblasts, that is preferentially found on cardiac derived fibroblasts is the collagen receptor Discoidin Domain Receptor 2 (DDR2 [ 77 ]).…”

Elucidation of GlcNAc‐binding properties of type III intermediate filament proteins, using GlcNAc‐bearing polymers

“…Interestingly, vimentin and another type III intermediate filament protein are co-expressed at the lesion sites. Type III intermediate filaments are expressed in various tissues, and over-expression of these filaments at disease sites has also been reported (Levin et al 2009;Teshigawara et al 2013;Lucotte et al 2015;Parlakian et al 2016). Therefore, as GlcNAc-bearing polymers such as AC-GlcNAc can strongly bind to cells over-expressing and cell surface-expressing two type III intermediate filament proteins, the targeting of these diseases using GlcNAc-bearing polymers may be an effective strategy for therapeutic and diagnostic applications.…”

“…For example, activated stellate cells over-expressing vimentin and desmin proliferate excessively in liver fibrosis (Iwaisako et al 2014). Reactive astrocytes over-expressing vimentin and GFAP are increased in Alzheimer's disease (Teshigawara et al 2013;Kamphuis et al 2015;Lucotte et al 2015), whereas peripheral nerves over-expressing vimentin and peripherin are increased in neurodegenerative diseases (Levin et al 2009;Parlakian et al 2016). Interestingly, vimentin and another type III intermediate filament protein are co-expressed at the lesion sites.…”

“…Many researchers investigated the cell surface expression of vimentin at sites of various diseases (Satelli & Li 2011;Mitra et al 2015;Satelli et al 2015). Type III intermediate filaments are expressed in various tissues, and over-expression of these filaments at disease sites has also been reported (Levin et al 2009;Teshigawara et al 2013;Lucotte et al 2015;Parlakian et al 2016). However, the cell surface expression of these proteins at such sites remains unknown.…”