Biology subjects

Sellier, C.

Publications and source records attributed to Sellier, C..

3 recordsLinked to original sources

bioRxiv2024

CREB3 gain of function variants protect against ALS

Amyotrophic lateral sclerosis (ALS) is a fatal and rapidly evolving neurodegenerative disease that arises from the loss of glutamatergic corticospinal neurons (CSN) and cholinergic motoneurons (MN). The disease is mostly sporadic, but genetics is expected to highly contribute to disease onset and progression. Genome wide association studies identified a few genetic disease modifiers, mostly associated with a negative outcome, and demonstrated that ALS is primarily a disease of excitatory glutamatergic neurons. Here, we reasoned that at least a subpart of genetic disease modifiers may directly modulate the molecular pathways selectively activated in vulnerable neurons as the disease progresses, and concentrated on CSN for their selective vulnerability and glutamatergic identity. We implemented comparative cross-species transcriptomics using snRNAseq data from postmortem motor cortex of ALS patients and controls, and longitudinal RNAseq data from anatomically defined CSN purified from the Sod1G86R mouse model of ALS. We report that disease vulnerable neuronal populations undergo ER stress and altered mRNA translation, and identify the transcription factor CREB3 and its regulatory network as a resilience marker of neuronal dysfunction in ALS. Using genetic and epidemiologic analyses we further identify the rare variant CREB3R119G (rs11538707) as a new disease modifier in ALS. Through gain of function, CREB3R119G decreases both the risk of developing ALS and the progression rate of ALS patients. This study reveals novel genetic variants that protect against ALS and highlights the benefice of combining transcriptomics and genetics to identify new disease modifiers and therapeutic targets.

genomics↗

bioRxiv2024

FUS controls muscle differentiation and structure through LLPS mediated recruitment of MEF2 and ETV5

FUS is an RNA binding protein mutated in amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by progressive muscle weakness. We show that ALS-associated FUS mutations lead to ultrastructural defects in muscle of FUS-ALS patients, with disruption of sarcomeres and mitochondria. Studies in mouse and Drosophila models demonstrate an evolutionary-conserved cell autonomous function of FUS in muscle development. Mechanistically, FUS is required for transcription of MEF2 dependent genes, binds to the promoter of genes bound by ETS transcription factors in particular ETV5 and co-activates transcription of MEF2 dependent genes with ETV5. FUS phase separates with ETV5 and MEF2A, and MEF2A binding to FUS is potentiated by ETV5. Last, Etv5 haploinsufficiency exacerbates muscle weakness in a mouse model of FUS-ALS. These findings establish FUS as an essential protein for skeletal muscle structure through its phase separation-dependent recruitment of ETV5 and MEF2, defining a novel pathway compromised in FUS-ALS.

neuroscience↗

bioRxiv2019

Highly clustered de novo frameshift variants in the neuronal splicing factor NOVA2 result in a specific abnormal C terminal part and cause a severe form of intellectual disability with autistic features.

The Neuro-Oncological Ventral Antigen 2 NOVA2 protein is a major factor regulating neuron specific alternative splicing, previously associated with an acquired neurologic condition, the paraneoplastic opsoclonus-myoclonus ataxia (POMA). We report here six individuals with de novo frameshift variants in the NOVA2 gene affected with a severe neurodevelopmental disorder characterized by intellectual disability (ID), motor and speech delay, autistic features, hypotonia, feeding difficulties, spasticity or ataxic gait and abnormal brain MRI. The six variants lead to the same reading frame, adding a common 133 aa long proline rich C-terminus part instead of the last KH RNA binding domain. We detected forty-one genes differentially spliced after NOVA2 inactivation in human neural cells. The mutant NOVA2 protein shows decreased ability to bind a target RNA, to regulate specific splicing events and to rescue the phenotype of altered retinotectal axonal pathfinding induced by loss of NOVA2 ortholog in zebrafish. Our results suggest a partial loss-of-function mechanism rather than a full heterozygous loss of function, although a specific contribution of the novel C terminal extension cannot be excluded on the basis of the genetic findings.

genetics↗