Biology subjects

Bennett, F.

Publications and source records attributed to Bennett, F..

3 recordsLinked to original sources

bioRxiv2023

Epidermal IL-33 drives inflammation in necroptosis-induced skin inflammation by recruiting TNF-producing immune cells.

Caspase-8 deficiency in the epidermis (caspase-8EKO) results in cutaneous inflammation resembling pustular psoriasis, triggered by necroptotic cell death of keratinocytes. Necroptosis is a highly proinflammatory form of programmed necrosis due to the release of intracellular molecules called alarmins, which can act as inflammatory mediators. However, their role in necroptosis-induced skin inflammation remains unexplored. Here, we demonstrate that alarmin IL-33 and its receptor ST2 are essential early mediators of necroptosis-induced skin inflammation. Genetic ablation of Il-33 or St2 dramatically delays lesion development and improves survival of caspase-8EKO animals. IL-33 is highly expressed in necroptotic epidermis of caspase-8EKO mice and induces immune cell recruitment in the skin upon keratinocyte necroptosis. Impairment of the IL33-ST2 axis does not affect epidermal necroptosis but reduces the recruitment of TNF-producing infiltrating immune cells and subsequent amplification of cutaneous inflammation. Collectively, our findings highlight a pivotal role for IL-33 and ST2 in necroptosis-induced skin inflammation. TeaserInhibition of IL-33/ST2 axis alleviates necroptosis-induced skin inflammation by reducing TNF production in the dermis.

immunology↗

bioRxiv2023

G2C4 targeting antisense oligonucleotides potently mitigate TDP-43 dysfunction in C9orf72 ALS/FTD human neurons

The G4C2 repeat expansion in the C9orf72 gene is the most common genetic cause of Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Many studies suggest that dipeptide repeat proteins produced from this repeat are toxic, yet, the contribution of repeat RNA toxicity is under investigated and even less is known regarding the pathogenicity of antisense repeat RNA. Recently, two clinical trials targeting G4C2 (sense) repeat RNA via antisense oligonucleotide failed despite a robust decrease in sense encoded dipeptide repeat proteins demonstrating target engagement. Here, in this brief report, we show that G2C4 antisense, but not G4C2 sense, repeat RNA is sufficient to induce TDP-43 dysfunction in induced pluripotent stem cell (iPSC) derived neurons (iPSNs). Unexpectedly, only G2C4, but not G4C2 sense strand targeting, ASOs mitigate deficits in TDP-43 function in authentic C9orf72 ALS/FTD patient iPSNs. Collectively, our data suggest that the G2C4 antisense repeat RNA may be an important therapeutic target and provide insights into a possible explanation for the recent G4C2 ASO clinical trial failure.

neuroscience↗

bioRxiv2022

Stathmin-2 loss leads to neurofilament-dependent axonal collapse driving motor and sensory denervation

The human mRNA most affected by TDP-43 loss-of-function is transcribed from the STMN2 gene and encodes stathmin-2 (also known as SCG10), whose loss is a neurodegenerative disease hallmark. Here using multiple in vivo approaches, including transient antisense oligonucleotide (ASO)-mediated suppression, chronic shRNA-mediated depletion in aging mice, and germline deletion, we establish stathmin-2 to be essential for acquisition and maintenance of neurofilament-dependent structuring of axoplasm critical for maintaining diameter and conduction velocity of large-myelinated axons. Sustained stathmin-2 loss from an otherwise mature adult nervous system is demonstrated over a time course of eight months to initiate and drive motor neuron disease that includes 1) shrinkage in inter-neurofilament spacing that is required to produce a three-dimensional space filling array that defines axonal caliber, 2) collapse of mature axonal caliber with tearing of outer myelin layers, 3) reduced conduction velocity, 4) progressive motor and sensory deficits (including reduction of the pain transducing neuropeptide CGRP), and 5) muscle denervation. Demonstration that chronic stathmin-2 reduction is itself sufficient to trigger motor neuron disease reinforces restoration of stathmin-2 as an attractive therapeutic approach for TDP-43-dependent neurodegeneration, including the fatal adult motor neuron disease ALS.

cell biology↗