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Molecules (Basel, Switzerland) Apr 2017Neuromuscular disorders such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy are neurodegenerative genetic diseases characterized primarily by muscle weakness... (Review)
Review
Neuromuscular disorders such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy are neurodegenerative genetic diseases characterized primarily by muscle weakness and wasting. Until recently there were no effective therapies for these conditions, but antisense oligonucleotides, a new class of synthetic single stranded molecules of nucleic acids, have demonstrated promising experimental results and are at different stages of regulatory approval. The antisense oligonucleotides can modulate the protein expression via targeting hnRNAs or mRNAs and inducing interference with splicing, mRNA degradation, or arrest of translation, finally, resulting in rescue or reduction of the target protein expression. Different classes of antisense oligonucleotides are being tested in several clinical trials, and limitations of their clinical efficacy and toxicity have been reported for some of these compounds, while more encouraging results have supported the development of others. New generation antisense oligonucleotides are also being tested in preclinical models together with specific delivery systems that could allow some of the limitations of current antisense oligonucleotides to be overcome, to improve the cell penetration, to achieve more robust target engagement, and hopefully also be associated with acceptable toxicity. This review article describes the chemical properties and molecular mechanisms of action of the antisense oligonucleotides and the therapeutic implications these compounds have in neuromuscular diseases. Current strategies and carrier systems available for the oligonucleotides delivery will be also described to provide an overview on the past, present and future of these appealing molecules.
Topics: Animals; Biological Transport; Cell-Penetrating Peptides; Clinical Trials as Topic; Drug Evaluation, Preclinical; Gene Transfer Techniques; Genetic Therapy; Humans; Muscular Atrophy, Spinal; Muscular Dystrophy, Duchenne; Neuromuscular Diseases; Oligonucleotides, Antisense; RNA Splicing; RNA, Messenger
PubMed: 28379182
DOI: 10.3390/molecules22040563 -
European Journal of Cell Biology Jun 2023Spinal muscular atrophy (SMA), the most common genetic cause of infantile death, is caused by a mutation in the survival of motor neuron 1 gene (SMN1), leading to the... (Review)
Review
Spinal muscular atrophy (SMA), the most common genetic cause of infantile death, is caused by a mutation in the survival of motor neuron 1 gene (SMN1), leading to the death of motor neurons and progressive muscle weakness. SMN1 normally produces an essential protein called SMN. Although humans possess a paralogous gene called SMN2, ∼90% of the SMN it produces is non-functional. This is due to a mutation in SMN2 that causes the skipping of a required exon during splicing of the pre-mRNA. The first treatment for SMA, nusinersen (brand name Spinraza), was approved by the FDA in 2016 and by the EMU in 2017. Nusinersen is an antisense oligonucleotide-based therapy that alters the splicing of SMN2 to make functional full-length SMN protein. Despite the recent advancements in antisense oligonucleotide therapy and SMA treatment development, nusinersen is faced with a multitude of challenges, such as intracellular and systemic delivery. In recent years, the use of peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs) in antisense therapy has gained interest. These are antisense oligonucleotides conjugated to cell-penetrating peptides such as Pips and DG9, and they have the potential to address the challenges associated with delivery. This review focuses on the historic milestones, development, current challenges, and future perspectives of antisense therapy for SMA.
Topics: Humans; Oligonucleotides, Antisense; Muscular Atrophy, Spinal; Morpholinos; Motor Neurons; RNA Splicing
PubMed: 37295266
DOI: 10.1016/j.ejcb.2023.151326 -
Annual Review of Pharmacology and... Jan 2021The genetic basis for most inherited neurodegenerative diseases has been identified, yet there are limited disease-modifying therapies for these patients. A new class of... (Review)
Review
The genetic basis for most inherited neurodegenerative diseases has been identified, yet there are limited disease-modifying therapies for these patients. A new class of drugs-antisense oligonucleotides (ASOs)-show promise as a therapeutic platform for treating neurological diseases. ASOs are designed to bind to the RNAs either by promoting degradation of the targeted RNA or by elevating expression by RNA splicing. Intrathecal injection into the cerebral spinal fluid results in broad distribution of antisense drugs and long-term effects. Approval of nusinersen in 2016 demonstrated that effective treatments for neurodegenerative diseases can be identified and that treatments not only slow disease progression but also improve some symptoms. Antisense drugs are currently in development for amyotrophic lateral sclerosis, Huntington's disease, Alzheimer's disease, Parkinson's disease, and Angelman syndrome, and several drugs are in late-stage research for additional neurological diseases. This review highlights the advances in antisense technology as potential treatments for neurological diseases.
Topics: Humans; Neurodegenerative Diseases; Oligonucleotides, Antisense; Parkinson Disease; Pharmaceutical Preparations; RNA
PubMed: 33035446
DOI: 10.1146/annurev-pharmtox-010919-023738 -
Clinical Therapeutics Nov 2023High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an... (Review)
Review
PURPOSE
High plasma concentrations of LDL and lipoprotein(a) (Lp[a]) are independent and causal risk factors for atherosclerotic cardiovascular disease (ASCVD). There is an unmet therapeutic need for high-risk patients with elevated levels of LDL-C and/or Lp(a). Recent advances in the development of nucleic acids for gene silencing (ie, triantennary N-acetylgalactosamine conjugated antisense-oligonucleotides [ASOs] and small interfering RNA [siRNA]) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) and Lp(a) offer effective and sustainable therapies.
METHODS
Related articles in the English language were identified through a search for original and review articles in the PubMed database using the following key terms: cardiovascular disease, dyslipidemia, PCSK9 inhibitors, Lp(a), LDL-cholesterol, familial hypercholesterolemia, siRNA, and antisense oligonucleotide and clinical trials (either alone or in combination).
FINDINGS
Inclisiran, the most advanced siRNA-treatment targeting hepatic PCSK9, is well tolerated, producing a >30% reduction on LDL-C levels in randomized controlled trials. Pelacarsen is the most clinical advanced ASO, whereas olpasiran and SLN360 are the 2 siRNAs directed against the mRNA of the LPA gene. Evidence suggests that all Lp(a)-targeting agents are safe and well tolerated, with robust and sustained reduction in plasma Lp(a) concentration up to 70% to 90% in individuals with elevated Lp(a) levels.
IMPLICATIONS
Cumulative evidence from clinical trials supports the value of ASO and siRNA therapies targeting the synthesis of PCSK9 and Lp(a) for lowering LDL-C and Lp(a) in patients with established ASCVD or high risk of ASCVD. Further research is needed to examine whether gene silencing therapy could improve clinical outcomes in patients with elevated LDL and/or Lp(a) levels. Confirmation of the tolerability and cost-effectiveness of long-term inhibition of PCSK9 and Lp(a) with this approach is essential.
Topics: Humans; Proprotein Convertase 9; Cholesterol, LDL; Cardiovascular Diseases; Lipoprotein(a); Oligonucleotides, Antisense; Atherosclerosis; RNA, Small Interfering
PubMed: 37524569
DOI: 10.1016/j.clinthera.2023.07.008 -
Molecules (Basel, Switzerland) Mar 2021Conditionally activated ("caged") oligonucleotides provide useful spatiotemporal control for studying dynamic biological processes, e.g., regulating in vivo gene... (Review)
Review
Conditionally activated ("caged") oligonucleotides provide useful spatiotemporal control for studying dynamic biological processes, e.g., regulating in vivo gene expression or probing specific oligonucleotide targets. This review summarizes recent advances in caging strategies, which involve different stimuli in the activation step. Oligo cyclization is a particularly attractive caging strategy, which simplifies the probe design and affords oligo stabilization. Our laboratory developed an efficient synthesis for circular caged oligos, and a circular caged antisense DNA oligo was successfully applied in gene regulation. A second technology is Transcriptome In Vivo Analysis (TIVA), where caged oligos enable mRNA isolation from single cells in living tissue. We highlight our development of TIVA probes with improved caging stability. Finally, we illustrate the first protease-activated oligo probe, which was designed for caspase-3. This expands the toolkit for investigating the transcriptome under a specific physiologic condition (e.g., apoptosis), particularly in specimens where light activation is impractical.
Topics: Animals; Cyclization; Enzyme Activation; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Humans; Light; Oligonucleotides; Oligonucleotides, Antisense; RNA, Messenger; Synthetic Biology
PubMed: 33803234
DOI: 10.3390/molecules26051481 -
Cells Oct 2023Antisense oligonucleotide-based (ASO) therapeutics have emerged as a promising strategy for the treatment of human disorders. Charge-neutral PMOs have promising... (Review)
Review
Antisense oligonucleotide-based (ASO) therapeutics have emerged as a promising strategy for the treatment of human disorders. Charge-neutral PMOs have promising biological and pharmacological properties for antisense applications. Despite their great potential, the efficient delivery of these therapeutic agents to target cells remains a major obstacle to their widespread use. Cellular uptake of naked PMO is poor. Cell-penetrating peptides (CPPs) appear as a possibility to increase the cellular uptake and intracellular delivery of oligonucleotide-based drugs. Among these, the DG9 peptide has been identified as a versatile CPP with remarkable potential for enhancing the delivery of ASO-based therapeutics due to its unique structural features. Notably, in the context of phosphorodiamidate morpholino oligomers (PMOs), DG9 has shown promise in enhancing delivery while maintaining a favorable toxicity profile. A few studies have highlighted the potential of DG9-conjugated PMOs in DMD (Duchenne Muscular Dystrophy) and SMA (Spinal Muscular Atrophy), displaying significant exon skipping/inclusion and functional improvements in animal models. The article provides an overview of a detailed understanding of the challenges that ASOs face prior to reaching their targets and continued advances in methods to improve their delivery to target sites and cellular uptake, focusing on DG9, which aims to harness ASOs' full potential in precision medicine.
Topics: Animals; Humans; Oligonucleotides, Antisense; Cell-Penetrating Peptides; Oligonucleotides; Morpholinos; Muscular Dystrophy, Duchenne; Muscular Atrophy, Spinal
PubMed: 37830609
DOI: 10.3390/cells12192395 -
International Journal of Molecular... May 2021Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder leading to paralysis, muscle atrophy, and death. Significant advances in antisense... (Review)
Review
Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder leading to paralysis, muscle atrophy, and death. Significant advances in antisense oligonucleotide treatment and gene therapy have made it possible for SMA patients to benefit from improvements in many aspects of the once devastating natural history of the disease. How the depletion of survival motor neuron (SMN) protein, the product of the gene implicated in the disease, leads to the consequent pathogenic changes remains unresolved. Over the past few years, evidence toward a potential contribution of gastrointestinal, metabolic, and endocrine defects to disease phenotype has surfaced. These findings ranged from disrupted body composition, gastrointestinal tract, fatty acid, glucose, amino acid, and hormonal regulation. Together, these changes could have a meaningful clinical impact on disease traits. However, it is currently unclear whether these findings are secondary to widespread denervation or unique to the SMA phenotype. This review provides an in-depth account of metabolism-related research available to date, with a discussion of unique features compared to other motor neuron and related disorders.
Topics: Animals; Disease Models, Animal; Genetic Therapy; Humans; Motor Neurons; Muscular Atrophy, Spinal; Oligonucleotides, Antisense; Phenotype; Survival of Motor Neuron 1 Protein
PubMed: 34072857
DOI: 10.3390/ijms22115913 -
International Journal of Molecular... Nov 2022Myotonic dystrophy type 1 (DM1) is a dominant genetic disease in which the expansion of long CTG trinucleotides in the 3' UTR of the myotonic dystrophy protein kinase ()... (Review)
Review
Myotonic dystrophy type 1 (DM1) is a dominant genetic disease in which the expansion of long CTG trinucleotides in the 3' UTR of the myotonic dystrophy protein kinase () gene results in toxic RNA gain-of-function and gene mis-splicing affecting mainly the muscles, the heart, and the brain. The CUG-expanded transcripts are a suitable target for the development of antisense oligonucleotide (ASO) therapies. Various chemical modifications of the sugar-phosphate backbone have been reported to significantly enhance the affinity of ASOs for RNA and their resistance to nucleases, making it possible to reverse DM1-like symptoms following systemic administration in different transgenic mouse models. However, specific tissue delivery remains to be improved to achieve significant clinical outcomes in humans. Several strategies, including ASO conjugation to cell-penetrating peptides, fatty acids, or monoclonal antibodies, have recently been shown to improve potency in muscle and cardiac tissues in mice. Moreover, intrathecal administration of ASOs may be an advantageous complementary administration route to bypass the blood-brain barrier and correct defects of the central nervous system in DM1. This review describes the evolution of the chemical design of antisense oligonucleotides targeting CUG-expanded mRNAs and how recent advances in the field may be game-changing by forwarding laboratory findings into clinical research and treatments for DM1 and other microsatellite diseases.
Topics: Mice; Humans; Animals; Myotonic Dystrophy; Myotonin-Protein Kinase; Oligonucleotides, Antisense; Mice, Transgenic; Oligonucleotides; 3' Untranslated Regions; Trinucleotide Repeat Expansion
PubMed: 36362145
DOI: 10.3390/ijms232113359 -
Drug Discoveries & Therapeutics 2016Therapeutic oligonucleotides are promising technologies. Nevertheless, improvement of their efficacy is an important issue. Introducing this drug delivery system (DDS)... (Review)
Review
Therapeutic oligonucleotides are promising technologies. Nevertheless, improvement of their efficacy is an important issue. Introducing this drug delivery system (DDS) makes for a great enhancement for delivery of oligonucleotides to targeted tissue or cells. The strategy of DDS for therapeutic oligonucleotides is divided into four categories, A) single piece of oligonucleotide, B) oligonucleotide-ligand conjugate, C) oligonucleotide-polymer conjugate, and D) nanoparticle. In this review we will describe those basic concepts, especially for the technology of conjugating ligand. In addition, we developed a new technology, heteroduplex oligonucleotide (HDO), binding ligand-molecule to antisense oligonucleotide indirectly. We also outline α-tocopherol (a natural isomer of vitamin E) conjugated HDO.
Topics: Drug Delivery Systems; Humans; Oligonucleotides; Oligonucleotides, Antisense; RNA, Small Interfering; Tocopherols
PubMed: 27890899
DOI: 10.5582/ddt.2016.01065 -
The Journal of Clinical Investigation Dec 2021De novo variation in SCN2A can give rise to severe childhood disorders. Biophysical gain of function in SCN2A is seen in some patients with early seizure onset...
De novo variation in SCN2A can give rise to severe childhood disorders. Biophysical gain of function in SCN2A is seen in some patients with early seizure onset developmental and epileptic encephalopathy (DEE). In these cases, targeted reduction in SCN2A expression could substantially improve clinical outcomes. We tested this theory by central administration of a gapmer antisense oligonucleotide (ASO) targeting Scn2a mRNA in a mouse model of Scn2a early seizure onset DEE (Q/+ mice). Untreated Q/+ mice presented with spontaneous seizures at P1 and did not survive beyond P30. Administration of the ASO to Q/+ mice reduced spontaneous seizures and significantly extended life span. Across a range of behavioral tests, Scn2a ASO-treated Q/+ mice were largely indistinguishable from WT mice, suggesting treatment is well tolerated. A human SCN2A gapmer ASO could likewise impact the lives of patients with SCN2A gain-of-function DEE.
Topics: Animals; Behavior, Animal; Biophysics; Disease Models, Animal; Electroencephalography; Epilepsy; Gain of Function Mutation; Humans; Longevity; Male; Maze Learning; Mice; Movement; Mutation; NAV1.2 Voltage-Gated Sodium Channel; Oligonucleotides, Antisense; Phenotype; RNA, Messenger; Seizures
PubMed: 34850743
DOI: 10.1172/JCI152079