Compositions and Methods for Improving Heart Function

A method for ameliorating diastolic impairment in calcium flux in a diabetic heart comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the heart, thereby ameliorating diastolic impairment in calcium flux;
• (ii) the method of (i), wherein the diabetic condition is type I diabetes or type II diabetes, or the diabetic heart is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for improving (normalizing) calcium cycling in a myocyte under hyperglycemic or diabetic conditions, or a diabetic heart, by enhancing the Ca2+ transient and sarcoplasmic reticulum Ca2+ loading, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or heart, thereby enhancing the Ca2+ transient and sarcoplasmic reticulum Ca2+ loading in the myocyte or heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for lowering PLB expression in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby lowering PLB expression in the myocyte or the heart;
• (ii) the method of (i), wherein the diabetic heart, or hyperglycemic or diabetic conditions is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for increasing or normalizing SERCA2a expression, SERCA2a/PLB ratio and/or SERCA2a activity in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby increasing or normalizing SERCA2a expression, SERCA2a/PLB ratio and/or SERCA2a activity in the myocyte or the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for increasing or normalizing phosphorylation levels of PLB in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby increasing or normalizing SERCA2a expression, SERCA2a/PLB ratio and/or SERCA2a activity in the myocyte or the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for increasing or normalizing SERCA2a promoter activity in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby increasing or normalizing SERCA2a promoter activity in the myocyte or the heart;
• (ii) the method of (i), wherein the diabetes is type I diabetes or type II diabetes, or the hyperglycemic or diabetic conditions is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for reducing cellular O-GlcNAcylation in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby reducing cellular O-GlcNAcylation in the myocyte or the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for reducing transcription factor Sp1 O-GlcNAcylation and increasing Sp1 activity in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby reducing transcription factor Sp1 O-GlcNAcylation and increasing Sp1 activity in the myocyte or the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for normalizing myocyte-specific enhancer factor-2 (MEF-2a) levels in a myocyte under hyperglycemic or diabetic conditions, or in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in the myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby normalizing the MEF-2a levels in the myocyte or the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for improving or normalizing cardiomyocyte contractility in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby improving or normalizing cardiomyocyte contractility in the heart;
• (ii) the method of (i), wherein the hyperglycemic or diabetic conditions, or diabetic heart, is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for improving or normalizing global contractility in a diabetic heart, the method comprising

• (i) (a) providing a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, or an O-GlcNAc (OGT) protein;
• and
• (b) administering an effective amount of the nucleic acid or OGT protein to the myocyte or the heart, thereby improving or normalizing global contractility in the heart;
• (ii) the method of (i), wherein the diabetes is type I diabetes or type II diabetes, or the hyperglycemic or diabetic conditions is caused by type I diabetes or type II diabetes;
• (iii) the method of (i) or (ii), wherein administering the effective amount of the nucleic acid or OGT protein causes reduction of excessive O-GlcNAcylation in cytosolic and/or nuclear proteins;
• (iv) the method of any of (i) to (iii), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (v) the method of (iv), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (vi) the method of (iv), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

A method for improving myocardial performance (contractility) or global heart contractility in a mammal comprising a step of enhancing or increasing O-linked GlcNAc transferase (O-GlcNAc, OGT) transferase (O-GlcNAcase, O-GlcNAc, OGT) activity, the method comprising

• (i) (a) providing (i) a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, (ii) an O-GlcNAc (OGT) protein, (iii) a compound that relieves inhibition of O-GlcNAc (OGT) activity;
• or (iv) a compound that increases O-GlcNAc (OGT) transcription;
• and
• (b) administering an effective amount of the nucleic acid, protein or compound of (a) to the heart, thereby improving myocardial performance or global heart contractility in the heart;
• (ii) the method of (i), wherein the mammal is diabetic, or the mammal is a diabetic human;
• or
• (iii) the method of (i) or (ii), wherein the mammal is a mouse, a rat, a rabbit, a hamster, a dog, a pig, a sheep or a monkey;
• (iv) the method of any of (i) to (iii), wherein the compound that increases O-GlcNAc (OGT) transcription comprises a transcriptional regulatory nucleic acid, and the method comprises inserting the transcriptional regulatory nucleic acid into the genome of a cell such that it increases transcription of O-GlcNAc (OGT) endogenous to the cell or relieves transcriptional inhibition of O-GlcNAc (OGT) endogenous to the cell;
• or
• (v) the method of (iv), wherein the transcriptional regulatory nucleic acid comprises a promoter or an enhancer.

A method for improving myocardial performance (contractility) or global heart contractility in a diabetic mammal or a hyperglycemic mammal comprising

• (i) (a) providing a pharmaceutical composition comprising (i) a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, (ii) an O-GlcNAc (OGT) protein, (iii) a compound that relieves inhibition of O-GlcNAc (OGT) activity;
• or (iv) a compound that increases O-GlcNAc (OGT) transcription;
• and
• (b) administering an effective amount of the pharmaceutical composition to a subject in need thereof, thereby improving the myocardial performance (contractility) or global heart contractility in the diabetic mammal or hyperglycemic mammal;
• (ii) the method of (i), wherein the compound that increases O-GlcNAc (OGT) transcription comprises a transcriptional regulatory nucleic acid, and the method comprises inserting the transcriptional regulatory nucleic acid into the genome of a cell such that it increases transcription of O-GlcNAc (OGT) endogenous to the cell or relieves transcriptional inhibition of O-GlcNAc (OGT) endogenous to the cell;
• or
• (iii) the method of (ii), wherein the transcriptional regulatory nucleic acid comprises a promoter or an enhancer.

A method for treating, ameliorating or preventing heart disease comprising poor myocardial performance associated with diabetic cardiomyopathy, comprising

• (i) (a) providing a pharmaceutical composition comprising (i) a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, (ii) an O-GlcNAc (OGT) protein, (iii) a compound that relieves inhibition of O-GlcNAc (OGT) activity;
• or (iv) a compound that increases O-GlcNAc (OGT) transcription;
• and
• (b) administering an effective amount of the pharmaceutical composition to a subject in need thereof, thereby treating, ameliorating or preventing heart disease comprising poor myocardial performance associated with diabetic cardiomyopathy;
• (ii) the method of (i), wherein the subject is a diabetic mammal, and optionally the mammal is a human, a mouse, a rat, a rabbit, a hamster, a dog, a pig, a sheep or a monkey;
• (iii) the method of (i) or (ii), wherein the compound that increases O-GlcNAc (OGT) transcription comprises a transcriptional regulatory nucleic acid, and the method comprises inserting the transcriptional regulatory nucleic acid into the genome of a cell such that it increases transcription of O-GlcNAc (OGT) endogenous to the cell or relieves transcriptional inhibition of O-GlcNAc (OGT) endogenous to the cell;
• or
• (iv) the method of (iii), wherein the transcriptional regulatory nucleic acid comprises a promoter or an enhancer.

An ex vivo method for treating, ameliorating or preventing heart disease comprising poor myocardial performance associated with diabetic cardiomyopathy comprising

• (i) (a) providing a cardiomyocyte, cardiomyocyte precursor cell or cardio-myocyte stem cell that overexpresses O-linked GlcNAc transferase (O-GlcNAc, OGT) by (i) inserting into the myocyte a nucleic acid encoding an O-linked GlcNAc transferase (O-GlcNAc, OGT), wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart, (ii) inserting into the myocyte an O-GlcNAc (OGT) protein, (iii) inserting into the myocyte a compound that relieves inhibition of O-GlcNAc (OGT) activity;
• (iv) inserting into the myocyte a compound that increases O-GlcNAc (OGT) transcription;
• or (v) inserting into the myocyte a transcriptional regulatory nucleic acid that it increases transcription of O-GlcNAc (OGT) endogenous to the cell or relieves transcriptional inhibition of O-GlcNAc (OGT) endogenous to the cell;
• and
• (b) administering the cardiomyocyte, cardiomyocyte precursor cell or cardio-myocyte stem cell to the heart of a subject in need thereof, thereby treating, ameliorating or preventing heart disease comprising poor myocardial performance associated with diabetic cardiomyopathy;
• (ii) the method of (i), wherein an O-linked GlcNAc transferase (O-GlcNAc, OGT) nucleic acid is contained within a cloning vehicle, an expression cassette or vector;
• (iii) the method of (ii), wherein the cloning vehicle, expression cassette or vector comprises a viral vector, a plasmid, a phage, a phagemid, a cosmid, a fosmid, a bacteriophage or an artificial chromosome;
• or
• (iv) the method of (iii), wherein the viral vector comprises an adenovirus vector, a retroviral vector or an adeno-associated viral vector, wherein optionally the retroviral vector comprises a lentiviral vector.

An isolated cardiomyocyte cell, cardiomyocyte precursor cell or cardio-myocyte stem cell comprising:

• (a) a nucleic acid encoding (i) an O-linked GlcNAc transferase (O-GlcNAc, OGT), (ii) an exogenous O-GlcNAc (OGT) protein, (iii) a compound that relieves inhibition of O-GlcNAc (OGT) activity;
• and/or (iv) a compound that increases O-GlcNAc (OGT) transcription,
• wherein the nucleic acid is operatively linked to a promoter constitutively or inducibly active in a myocyte or the heart;
• or
• (b) the isolated cardiomyocyte cell, cardiomyocyte precursor cell or cardio-myocyte stem cell of (a), wherein the cell and/or the O-linked GlcNAc transferase (O-GlcNAc, OGT) are derived from a human.

A non-human transgenic animal comprising

• (i) a heterologous O-linked GlcNAc transferase (O-GlcNAc, OGT) coding sequence;
• (ii) the non-human transgenic animal of (i), wherein the animal is a goat, a rabbit, a sheep, a pig, a dog, a cow, a cat, a rat or a mouse;
• or,
• (iii) the non-human transgenic animal of (i) or (ii), wherein the endogenous O-linked GlcNAc transferase (O-GlcNAc, OGT) gene of the non-human transgenic animal is completely or partially disabled (“knocked out”).