Cell Type Distribution of Intrathecal Antisense Oligonucleotide Activity in Deep Brain Regions of Non-Human Primates.

Intrathecally administered RNase H1-active gapmer antisense oligonucleotides (ASOs) are promising therapeutics for brain diseases where lowering the expression of one target gene is expected to be therapeutically beneficial. Such ASOs are active, to varying degrees, across most or all cell types in the cortex and cerebellum of mouse and non-human primate (NHP) brain regions with substantial drug accumulation. Intrathecally delivered ASOs, however, exhibit a gradient of exposure across the brain, with more limited drug accumulation and weaker target engagement in deep brain regions of NHP.

Therapeutic antisense oligonucleotide mitigates retinal dysfunction in a pig model of CLN3 Batten disease.

CLN3 Batten disease is a lethal pediatric autosomal recessive neurodegenerative disease caused by mutations in the gene. Typically, the disease manifests as vision loss early in life and progresses to neurological dysfunction and death in young adulthood. Therapeutic development has focused on treating the central nervous system.

Antisense oligonucleotide jacifusen for FUS-ALS: an investigator-initiated, multicentre, open-label case series.

Background: Pathogenic variants of fused in sarcoma (FUS) cause amyotrophic lateral sclerosis (FUS-ALS), with evidence of gain of function. Jacifusen is an antisense oligonucleotide targeting FUS pre-mRNA, previously shown to delay neurodegeneration in a mouse model and potentially slow functional decline in a first-in-human study. Here, we sought to further evaluate use of jacifusen as a treatment for FUS-ALS.

The differential impact of HNRNPA1 isoforms on gene expression and their relevance to dsRNA-mediated innate immune response.

Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) is a highly abundant RNA binding protein alternatively spliced in two main isoforms named, hnRNP A1 and hnRNP A1B. While being ubiquitously expressed, both isoforms have different cellular localizations and are differentially expressed in tissues during development and aging. To improve our understanding of the cellular function of each isoform, we performed RNA sequencing in cells exclusively expressing hnRNP A1 or hnRNP A1B.

Skeletal muscle effects of antisense oligonucleotides targeting glycogen synthase 1 in a mouse model of Pompe disease.

Pompe disease (PD) is a progressive myopathy caused by the aberrant accumulation of glycogen in skeletal and cardiac muscle resulting from the deficiency of the enzyme acid alpha-glucosidase (GAA). Administration of recombinant human GAA as enzyme replacement therapy (ERT) works well in alleviating the cardiac manifestations of PD but loses sustained benefit in ameliorating the skeletal muscle pathology. The limited efficacy of ERT in skeletal muscle is partially attributable to its inability to curb the accumulation of new glycogen produced by the muscle enzyme glycogen synthase 1 (GYS1).

Conjugation to a transferrin receptor 1-binding Bicycle peptide enhances ASO and siRNA potency in skeletal and cardiac muscles.

Improving the delivery of antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) to skeletal and cardiac muscles remains a pivotal task toward the broader application of oligonucleotide therapeutics. The targeting of myofibers and cardiomyocytes via conjugation of ASOs and siRNAs to ligands that bind the human transferrin receptor 1 (TfR1) has gathered significant interest in recent years. However, the selection of ligands with low molecular weight and optimal biophysical and binding properties is crucial to maximize the potential of the TfR1 ligand-conjugated antisense (LICA) technology.

Loss of CHOP Prevents Joint Degeneration and Pain in a Mouse Model of Pseudoachondroplasia.

Pseudoachondroplasia (PSACH), a severe dwarfing condition characterized by impaired skeletal growth and early joint degeneration, results from mutations in cartilage oligomeric matrix protein (COMP). These mutations disrupt normal protein folding, leading to the accumulation of misfolded COMP in chondrocytes. The MT-COMP mouse is a murine model of PSACH that expresses D469del human COMP in response to doxycycline and replicates the PSACH chondrocyte and clinical pathology.

A NOTCH3 pathogenic variant influences osteogenesis and can be targeted by antisense oligonucleotides in induced pluripotent stem cells.

Lateral Meningocele Syndrome (LMS), a disorder associated with NOTCH3 pathogenic variants, presents with neurological, craniofacial and skeletal abnormalities. Mouse models of the disease exhibit osteopenia that is ameliorated by the administration of Notch3 antisense oligonucleotides (ASO) targeting either Notch3 or the Notch3 mutation. To determine the consequences of LMS pathogenic variants in human cells and whether they can be targeted by ASOs, induced pluripotent NCRM1 and NCRM5 stem (iPS) cells harboring a NOTCH36692-93insC insertion were created.

Targeting mechanistic target of rapamycin complex 2 attenuates immunopathology in systemic lupus erythematosus.

Objective: We aimed to explore the role of mechanistic target of rapamycin complex (mTORC) 2 in SLE development, and the in vivo regulation of mTORC2 by type I IFN signalling in autoimmunity, and to use mTORC2 targeting therapy to ameliorate lupus-like symptoms in an in vivo lupus mouse model and an in vitro co-culture model using human peripheral blood mononuclear cells (PBMCs).

Method: We first induced lupus-like disease in T-cell-specific Rictor, a key component of mTORC2-deficient mice, by topical application of imiquimod (IMQ), and monitored disease development. Next, we investigated the changes in mTORC2 signalling and immunological phenotypes in type I IFNAR-deficient Lpr mice.

Molecular Profiling of Mouse Models of Loss or Gain of Function of the KCNT1 (Slack) Potassium Channel and Antisense Oligonucleotide Treatment.

The potassium sodium-activated channel subtype T member 1 () gene encodes the Slack channel K1.1, which is expressed in neurons throughout the brain. Gain-of-function variants in are associated with a spectrum of epilepsy syndromes, and mice carrying those variants exhibit a robust phenotype similar to that observed in patients.

Reduction of RAD23A extends lifespan and mitigates pathology in TDP-43 mice.

Protein misfolding and aggregation are cardinal features of neurodegenerative disease (NDD) and they contribute to pathophysiology by both loss-of-function (LOF) and gain-of-function (GOF) mechanisms. This is well exemplified by TDP-43 which aggregates and mislocalizes in several NDDs. The depletion of nuclear TDP-43 leads to reduction in its normal function in RNA metabolism and the cytoplasmic accumulation of TDP-43 leads to aberrant protein homeostasis.

Modeling antisense oligonucleotide therapy in MECP2 duplication syndrome human iPSC-derived neurons reveals gene expression programs responsive to MeCP2 levels.

Genomic copy-number variations (CNVs) that can cause neurodevelopmental disorders often encompass many genes, which complicates our understanding of how individual genes within a CNV contribute to pathology. MECP2 duplication syndrome (MDS or MRXSL in OMIM; OMIM#300260) is one such CNV disorder caused by duplications spanning methyl CpG-binding protein 2 (MECP2) and other genes on Xq28. Using an antisense oligonucleotide (ASO) to normalize MECP2 dosage is sufficient to rescue abnormal neurological phenotypes in mouse models overexpressing MECP2 alone, implicating the importance of increased MECP2 dosage within CNVs of Xq28.

Targeting mechanistic target of rapamycin complex 2 attenuates immunopathology in Systemic Lupus Erythematosus.

Objective: We aim to explore the role of mechanistic target of rapamycin complex (mTORC) 2 in systemic lupus erythematosus (SLE) development, the in regulation of mTORC2 by type I interferon (IFN) signaling in autoimmunity, and to use mTORC2 targeting therapy to ameliorate lupus-like symptoms in an lupus mouse model and an coculture model using human PBMCs.

Method: We first induced lupus-like disease in T cell specific , a key component of mTORC2, deficient mice by topical application of imiquimod (IMQ) and monitored disease development. Next, we investigated the changes of mTORC2 signaling and immunological phenotypes in type I IFNAR deficient Lpr mice.

Skeletal muscle effects of antisense oligonucleotides targeting glycogen synthase 1 in a mouse model of Pompe disease.

Pompe disease (PD) is a progressive myopathy caused by the aberrant accumulation of glycogen in skeletal and cardiac muscle resulting from the deficiency of the enzyme acid alpha-glucosidase (GAA). Administration of recombinant human GAA as enzyme replacement therapy (ERT) works well in alleviating the cardiac manifestations of PD but loses sustained benefit in ameliorating the skeletal muscle pathology. The limited efficacy of ERT in skeletal muscle is partially attributable to its inability to curb the accumulation of new glycogen produced by the muscle enzyme glycogen synthase 1 (GYS1).

Generation of five induced pluripotent stem cell lines from patients with MECP2 Duplication Syndrome.

MECP2 Duplication Syndrome (MDS) is a rare, severe neurodevelopmental disorder arising from duplications in the Xq28 region containing the MECP2 gene that predominantly affects males. We generated five human induced pluripotent stem cell (iPSC) lines from the fibroblasts of individuals carrying between 0.355 and 11.

GC targeting antisense oligonucleotides potently mitigate TDP-43 dysfunction in human C9orf72 ALS/FTD induced pluripotent stem cell derived neurons.

The GC 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 GC (sense) repeat RNA via antisense oligonucleotide failed despite a robust decrease in sense-encoded dipeptide repeat proteins demonstrating target engagement.

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

The mRNA transcript of the human STMN2 gene, encoding for stathmin-2 protein (also called SCG10), is profoundly impacted by TAR DNA-binding protein 43 (TDP-43) loss of function. The latter is a hallmark of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Using a combination of approaches, including transient antisense oligonucleotide-mediated suppression, sustained shRNA-induced depletion in aging mice, and germline deletion, we show that stathmin-2 has an important role in the establishment and maintenance of neurofilament-dependent axoplasmic organization that is critical for preserving the caliber and conduction velocity of myelinated large-diameter axons.

Antisense oligonucleotides targeting the miR-29b binding site in the GRN mRNA increase progranulin translation.

Heterozygous GRN (progranulin) mutations cause frontotemporal dementia (FTD) due to haploinsufficiency, and increasing progranulin levels is a major therapeutic goal. Several microRNAs, including miR-29b, negatively regulate progranulin protein levels. Antisense oligonucleotides (ASOs) are emerging as a promising therapeutic modality for neurological diseases, but strategies for increasing target protein levels are limited.

Targeted suppression of mTORC2 reduces seizures across models of epilepsy.

Epilepsy is a neurological disorder that poses a major threat to public health. Hyperactivation of mTOR complex 1 (mTORC1) is believed to lead to abnormal network rhythmicity associated with epilepsy, and its inhibition is proposed to provide some therapeutic benefit. However, mTOR complex 2 (mTORC2) is also activated in the epileptic brain, and little is known about its role in seizures.

PFTK1 kinase regulates axogenesis during development via RhoA activation.

Background: PFTK1/Eip63E is a member of the cyclin-dependent kinases (CDKs) family and plays an important role in normal cell cycle progression. Eip63E expresses primarily in postnatal and adult nervous system in Drosophila melanogaster but its role in CNS development remains unknown. We sought to understand the function of Eip63E in the CNS by studying the fly ventral nerve cord during development.

Reduction of is therapeutic in mouse models of and epilepsy.

Developmental and epileptic encephalopathies (DEEs) are severe seizure disorders with inadequate treatment options. Gain- or loss-of-function mutations of neuronal ion channel genes, including potassium channels and voltage-gated sodium channels, are common causes of DEE. We previously demonstrated that reduced expression of the sodium channel gene is therapeutic in mouse models of sodium and potassium channel mutations.

Antisense oligonucleotides targeting a NOTCH3 mutation in male mice ameliorate the cortical osteopenia of lateral meningocele syndrome.

Lateral Meningocele Syndrome (LMS) is a monogenic disorder associated with NOTCH3 pathogenic variants that result in the stabilization of NOTCH3 and a gain-of-function. A mouse model (Notch3) harboring a 6691-TAATGA mutation in the Notch3 locus that results in a functional outcome analogous to LMS exhibits cancellous and cortical bone osteopenia. We tested Notch3 antisense oligonucleotides (ASOs) specific to the Notch3 mutation for their effects on Notch3 downregulation and on the osteopenia of Notch3 mice.