Systematic elucidation of neuron-astrocyte interaction in models of amyotrophic lateral sclerosis using multi-modal integrated bioinformatics workflow

Vartika Mishra,Harry Ischiropoulos,Virginia Le Verche,Diane B Ré ,Kristin A Politi,Paola Rinchetti,Stefania Corti,Alessandro Vasciaveo,Monica Nizzardo,Dimitra Papadimitriou,Francesco Lotti,Andrea Califano,Kevin Clare,Manuel E Than,Arnaud Jacquier,Paschalis Tomas Doulias ,Todd M Greco,Burcin Ikiz,Mariano J Alvarez,Tetsuya Nagata,Eduardo Pérez-Torres ,Serge Przedborski

doi:10.1038/s41467-020-19177-y

Abstract

Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking. Herein, we propose an approach for the Systematic Elucidation and Assessment of Regulatory Cell-to-cell Interaction Networks (SEARCHIN) to identify ligand-mediated interactions between distinct cellular compartments. To test this approach, we selected a model of amyotrophic lateral sclerosis (ALS), in which astrocytes expressing mutant superoxide dismutase-1 (mutSOD1) kill wild-type motor neurons (MNs) by an unknown mechanism. Our integrative analysis that combines proteomics and regulatory network analysis infers the interaction between astrocyte-released amyloid precursor protein (APP) and death receptor-6 (DR6) on MNs as the top predicted ligand-receptor pair. The inferred deleterious role of APP and DR6 is confirmed in vitro in models of ALS. Moreover, the DR6 knockdown in MNs of transgenic mutSOD1 mice attenuates the ALS-like phenotype. Our results support the usefulness of integrative, systems biology approach to gain insights into complex neurobiological disease processes as in ALS and posit that the proposed methodology is not restricted to this biological context and could be used in a variety of other non-cell-autonomous communication mechanisms.

Highlights

Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking
RNA interference (RNAi)-mediated knockdown of death receptor-6 (DR6) in MNsattenuated neurodegeneration. In light of these data and of our previous studies[8,9], we propose a pathogenic model of neurodegeneration in amyotrophic lateral sclerosis (ALS) in which astrocyte-specific release of a soluble fragment of amyloid precursor protein (APP), and possibly of other ligands prioritized by our analysis, activates DR6 at the surface of motor neurons (MNs), triggering a death signal that culminates in the demise of spinal MNs via NF-κB1-dependent pathway
We found that the Q-column eluates from mutant superoxide dismutase-1 (mutSOD1) ACMs were associated with greater MN loss at 7 DIV, compared with unfiltered mutSOD1 ACMs after 5 days incubation (Fig. 1a)

Summary

Introduction

Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking. We propose an approach for the Systematic Elucidation and Assessment of Regulatory Cell-to-cell Interaction Networks (SEARCHIN) to identify ligand-mediated interactions between distinct cellular compartments To test this approach, we selected a model of amyotrophic lateral sclerosis (ALS), in which astrocytes expressing mutant superoxide dismutase-1 (mutSOD1) kill wild-type motor neurons (MNs) by an unknown mechanism. It has been reported that mutSOD1-expressing glial-restricted precursor cells grafted onto spinal cords (SCs) of WT rats were associated with MN loss in living animals[21] and that selective reduction of mutSOD1 levels in astrocytes prolonged survival in transgenic (Tg) SOD1G37R mice[22] Taken together, these observations suggest that astrocyte-mediated MN degeneration is a general phenomenon in ALS and is not restricted to in vitro systems, mouse cells, or mutSOD1-linked ALS. The precise mechanisms promoting astrocyte-induced demise of neighboring

Methods

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Conclusion