Provided are compounds, methods, and pharmaceutical compositions for reducing the amount or activity of MSH3 RNA in a cell or subject, and in certain instances reducing the amount of MSH3 protein in a cell or subject. These compounds, methods, and pharmaceutical compositions are useful to ameliorate at least one symptom or hallmark of a repeat expansion disease. Such symptoms and hallmarks include brain atrophy, muscle atrophy, nerve degeneration, uncontrolled movement, seizure, tremors, muscle weakness, muscle cramping, difficulty swallowing, difficulty speaking, decreased memory, decreased cognition, anxiety, and depression. Non-limiting examples of repeat expansion diseases that benefit from these compounds, methods, and pharmaceutical compositions are myotonic dystrophy (DM1 and DM2), amyotrophic lateral sclerosis, frontotemporal dementia, Huntington's disease, various polyglutamine disorders, Friedrich's ataxia, Fragile X syndrome, or spinocerebellar ataxia (e.g., SCA1, SCA2, SCA3, SCA6, SCAT, SCA8, SCA10, or SCA17).

In some embodiments, the invention is directed to a method for diagnosing fibrosis and/or fibrosis related diseases and to a method for screening a pharmaceutically active compound for the treatment of fibrosis and/or fibrosis related diseases. The present invention further relates to compositions for use in the treatment, amelioration, and/or prevention of fibrosis. In certain embodiments, the compositions modulate the activity of a miRNA for the treatment, amelioration, and/or prevention of fibrosis. In certain embodiments, the compositions inhibit the activity of miR-21 for the treatment, amelioration, and/or prevention of fibrosis.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload inhibits activity of a disease allele associated with muscle disease. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload inhibits expression or activity of DUX4. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.

Described are RNAi agents, compositions that include RNAi agents, and methods for inhibition of a beta-ENaC (SCNN1B) gene. The beta-ENaC RNAi agents and RNAi agent conjugates disclosed herein inhibit the expression of a beta-ENaC gene. Pharmaceutical compositions that include one or more beta-ENaC RNAi agents, optionally with one or more additional therapeutics, are also described. Delivery of the described beta-ENaC RNAi agents to epithelial cells, such as pulmonary epithelial cells, in vivo, provides for inhibition of beta-ENaC gene expression and a reduction in ENaC activity, which can provide a therapeutic benefit to subjects, including human subjects, for the treatment of various diseases including chronic obstructive pulmonary disease (COPD).

Provided herein are compounds comprising cyclic cell penetrating peptides and antisense compounds. Also provided herein are methods of modulating splicing, inhibiting or regulating translation, mediating degradation, blocking expansions of nucleotide repeats, and treating disease using the aforementioned compounds.

Molecules are provided for inducing or facilitating exon skipping in forming spliced mRNA products from pre-mRNA molecules in cells. The molecules may be provided directly as oligonucleotides or expression products of vectors that are administered to a subject. High rates of skipping can be achieved. High rates of skipping reduce the severity of a disease like Duchene Muscular Dystrophy so that the disease is more like Becker Muscular Dystrophy. This is a severe reduction in symptom severity and mortality.

Disclosed herein are methods for decreasing AlAT mRNA and protein expression and treating, ameliorating, preventing, slowing progression, or stopping progression of fibrosis. Disclosed herein are methods for decreasing A1AT mRNA and protein expression and treating, ameliorating, preventing, slowing progression, or stopping progression of liver disease, such as, A1ATD associated liver disease, and pulmonary disease, such as, A1ATD associated pulmonary disease in an individual in need thereof. Methods for inhibiting AlAT mRNA and protein expression can also be used as a prophylactic treatment to prevent individuals at risk for developing a liver disease, such as, A1ATD associated liver disease and pulmonary disease, such as, A1ATD associated pulmonary disease.

Disclosed herein are methods for inhibiting or activating the transcription of a gene of interest, or inhibiting or activating the transcription of specific mRNA isoforms of a gene by using antisense oligonucleotides and/or small molecules. Also described herein are methods for activating transcription from a promoter and increasing overall gene expression by creating of a new splice site in a gene of a cell.

Disclosed herein are embodiments of a compound useful for treating or preventing SARS-Cov-2 infections. Also disclosed is a method for administering the compound to a subject, particularly a human subject, to treat or prevent a SARS-CoV-2 infection in the subject. The compound may comprise an oligomer comprising a nucleic acid base sequence that is antisense to a gene, pre-mRNA or mRNA in the subject, such as a gene, pre-mRNA or mRNA of transmembrane serine protease 2 (TMPRSS2). The compound also may comprise a peptide sequence. In some embodiments, the compound is a peptide-conjugated phosphorodiamidate morpholino oligomer (PPMO).