Provided herein are compositions and methods for treating a disorder associated with abnormal RYR2 function (e.g., arrhythmia or heart failure). In some embodiments, method comprises administering to a subject in need thereof an effective amount of a polypeptide comprising a C-terminal domain of Cardiac Myosin binding protein C (MYBPC3) or a nucleic acid or an rAAV encoding such polypeptide.

The present invention provides a method of treating heart failure with reduced ejection fraction, by administering to a patient at risk of such damage, a pharmaceutically effective amount of a composition which inhibits the anchoring of PP2A to mAKAPβ. This composition is preferably in the form of a viral based gene therapy vector that encodes a fragment of mAKAPβ to which PP2A binds.

Methods for the treatment or prevention of disease, such as fatty liver disease and obesity, are described including the modulation the amount of CTRP1 in a subject. Novel mouse strains are also described.

Compositions and methods for delivery of mRNA agents to subjects are provided in which the mRNA agents are encapsulated in exosomes prepared from human stem cells or progenitor cells, such as human mesenchymal stem cells, human embryonic stem cells or human cardiac progenitor cells. The compositions and methods can be used for delivery of mRNA agents encoding therapeutics, such as enzymes (e.g., metabolic enzymes), cytokines, growth factors, antigens, antibodies or immunomodulatory agents, by administering the compositions to the subject. Methods of preparing compositions comprising exosomes encapsulating mRNA agents are also provided.

Provided herein are variant adeno-associated virus (AAV) capsid proteins having one or more modifications in amino acid sequence relative to a parental AAV capsid protein, which, when present in an AAV virion, confer increased infectivity of one or more types of muscle cells as compared to the infectivity of the muscle cells by an AAV virion comprising the unmodified parental AAV capsid protein. Also provided are recombinant AAV virions and pharmaceutical compositions thereof comprising a variant AAV capsid protein as described herein, methods of making these rAAV capsid proteins and virions, and methods for using these rAAV capsid proteins and virions in research and in clinical practice, for example in, e.g., the delivery of nucleic acid sequences to one or more muscle cells for the treatment of muscle disorders and diseases.

The invention relates to a method for inducing or promoting skipping of exon 45 of DMD pre-mRNA in a Duchenne Muscular Dystrophy patient, preferably in an isolated (muscle) cell, the method comprising providing said cell with an antisense molecule that binds to a continuous stretch of at least 21 nucleotides within said exon. The invention further relates to such antisense molecule used in said method.

Described herein are methods of treating muscular dystrophy comprising administering a self complementary recombinant AAV (rAAV) scAAVrh74.MHCK7.hSGCB vector, methods of expressing beta-sarcoglycan gene in a patient, pharmaceutical compositions comprising the rAAV, and methods of generating the rAAV.

The disclosure provides compositions and methods for delivering a payload to cells or tissues that express GLUT4. In some embodiments, the compositions comprise an antibody, or fragment or derivative thereof, that specifically binds to glucose transporter 4 (“GLUT4”) protein, and a therapeutic payload conjugated thereto. In some exemplary embodiments, the compositions are useful for methods of treating a disease or condition in a subject with a genetic mutation in a gene encoding dystrophin protein, wherein the payload comprises a nucleic acid encoding a functional dystrophin protein or functional fragment thereof to ameliorate aspects of the disease.

Provided herein are variant adeno-associated virus (AAV) capsid proteins having one or more modifications in amino acid sequence relative to a parental AAV capsid protein, which, when present in an AAV virion, confer increased infectivity of one or more types of muscle cells as compared to the infectivity of the muscle cells by an AAV virion comprising the unmodified parental AAV capsid protein. Also provided are recombinant AAV virions and pharmaceutical compositions thereof comprising a variant AAV capsid protein as described herein, methods of making these rAAV capsid proteins and virions, and methods for using these rAAV capsid proteins and virions in research and in clinical practice, for example in, e.g., the delivery of nucleic acid sequences to one or more muscle cells for the treatment of muscle disorders and diseases.

The invention provides for recombinant AAV vectors comprising a polynucleotide sequence comprising the guide strand of miR-29c and methods of using the recombinant vectors to reduce or prevent fibrosis in subjects suffering from dystrophinopathy or muscular dystrophy. The invention also provides for combination therapies comprising expressing both miR-29 and micro-dystrophin to reduce and prevent fibrosis in patients suffering from dystrophinopathy or muscular dystrophy.