Partial rescue of neuronal genes deregulated in Cornelia de Lange Syndrome by cohesin

Abstract

Cornelia de Lange Syndrome (CdLS) is a human developmental disorder caused by mutations that compromise the function of cohesin, a major regulator of 3D genome organization. Cognitive impairment is a universal and as yet unexplained feature of CdLS. We characterized the transcriptional profile of cortical neurons from CdLS patients and found deregulation of hundreds of genes enriched for neuronal functions related to synaptic transmission, signalling processes, learning and behaviour. Inducible proteolytic cleavage of cohesin disrupted 3-D genome organization and transcriptional control in post-mitotic cortical mouse neurons. The genes affected belonged to similar gene ontology classes and showed significant numerical overlap with those deregulated in CdLS. Interestingly, gene expression was largely rescued by subsequent reconstitution of cohesin function. These experiments show that cohesin is continuously required for neuronal gene expression and provide a tractable approach for addressing mechanisms of neuronal dysfunction in CdLS.

Reliance of neuronal gene expression on cohesin scales with chromatin loop length

“…Genotypes were determined by PCR as previously reported 38,39 . Rad21 tev/tev mice have been described 4,61,62 .…”

“…Dissociated neurons were maintained in Neurobasal medium with B27 supplement (Invitrogen), 1 mM L-glutamine, and 100 U/mL penicillin/streptomycin for 10 days in vitro. For RAD21-TEV experiments, mouse cortices were dissected and dissociated on E14.5 -15.5 as described 4 . Neurons were maintained in Neurobasal medium with B27 supplement (Invitrogen), 1mM L-glutamine, and 100U/ml penicillin/streptomycin.…”

“…Acute proteolytic degradation of RAD21 (RAD21-TEV, Ref. 4 ) corroborated that cohesin is required for the expression genes involved in neuronal maturation, homeostasis, and activation.…”

“…In turn, neuronal maturation, morphological complexity, synapse formation and connectivity facilitate the expression of activitydependent genes [20][21][22][23][24] . To address whether the downregulation of activity-dependent genes observed in Rad21 lox/lox Nex Cre neurons was a cause or a consequence of impaired maturation we examined gene expression changes 24 h after acute proteolytic degradation of RAD21-TEV depletion in post-mitotic neurons 4 . We found remarkable overlap between acute degradation of RAD21-TEV and genetic cohesin depletion in Rad21 lox/lox Nex Cre neurons (P < 2.22e-16, odds ratio = 8.24 for all deregulated genes, odds ratio = 23.81 for downregulated genes; Fig.…”

“…Human mutations in CTCF and cohesin-related factors result in intellectual disability [1][2][3] and are accompanied by defects in neuronal gene expression 4 . In addition to canonical functions in the cell cycle 5 , cohesin cooperates with the sequence-specific DNA binding protein CTCF in the 3-dimensional (3D) organization of the genome.…”