SBIR-STTR Award

Growing lines of evidence suggest that cardiac myocyte death, including apoptosis, is intimately involved in the pathogenesis of heart failure. Thus, an important therapeutic objective in reducing morbidity and mortality in patients with heart diseases is to prevent the cardiac myocyte loss, including apoptosis. We have recently identified that mammalian sterile 20 like kinase 1 (Mst1) plays an important role in mediating cardiac myocyte apoptosis and is intimately involved in the pathogenesis of congestive heart failure. Inhibition of endogenous Mst1 suppresses cardiac myocyte apoptosis in response to ischemia/reperfusion, doxorubicin-induced cardiotoxicity and cardiac remodeling, thereby reducing the size of myocardial infraction and improving long-term cardiac function in transgenic mice. Mst1 is unique among many pro-apoptotic molecules in that 1) Mst1 and caspase-3 stimulate a positive feed back mechanism, thereby powerfully amplifying apoptosis and that 2) Mst1 also inhibits cell growth response and mitochondrial functions, all of which should negatively affect cardiac function. Thus, we reasoned that Mst1 could be an important target to prevent cardiac myocyte death and progression of heart failure. Thus, our long-term goals are 1) to provide unequivocal evidence that inhibition of Mst1 is salutary for prevention of cardiac myocyte death in response to ischemia/reperfusion and heart failure in large animals in vivo, and to provide the rationale for the future efforts to develop small molecule inhibitors for Mst1, and 2) to identify the lead compound for the Mst1 inhibitor. We have recently identified that a 63 amino acid sequence derived from the C-terminus portion of Mst1 inhibits protein kinase activity of Mst1. Using this Mst1 -inhibitory peptide (Mst1-IP) as a tool, our goals in this Phase I studies are 1) to test whether extracellular treatment of cultured cardiac myocytes with the Mst1-IP conjugated with the cell permeable TAT sequence inhibits the kinase activity of Mst1 and blocks apoptosis in response to hypoxia/reoxygenation in cultured cardiac myocytes, 2) to narrow down the amino acid sequence required for the Mst1-IP to block the kinase activity of Mst1 3) and to develop a rapid assay system for determining the kinase activity of Mst1. The studies outlined here will be essential for us to conduct Phase II studies, in which we will obtain unequivocal evidence that the Mst1 inhibitor is useful for treatment of ischemia/reperfusion in large animals in vivo and identify the lead compound for further development of the Mst1 inhibitor

Almost 20 million people suffer from ischemic heart diseases in US and one million patients develop myocardial infarction (MI) every year. Many patients develop heart failure even if they survive the acute event, which clearly indicates that current interventions are not sufficient. Thus, the development of a new class of medicine, which prevents ischemia/reperfusion (I /R) injury, would have a large market opportunity and significant clinical advance. Cardiac myocyte death, including apoptosis, is intimately involved in the pathogenesis of heart failure. Mammalian sterile 20 like kinase 1 (Mst1) plays an important role in mediating cardiac myocyte apoptosis and is intimately involved in the pathogenesis of congestive heart failure (Vasade, US patent 7160859, 2007). Using transgenic mice with cardiac specific overexpression of dominant negative Mst1 (Tg-DN-Mst1), inhibition of endogenous Mst1 suppresses cardiac myocyte apoptosis in response to I/R, thereby reducing the size of MI and improving long-term cardiac function. One of the long-term goals of Vasade is to develop Mst1 specific inhibitors for the treatment of I/R injury. Through our effort made possible by the phase I STTR grant from NIH, Vasade 1) has discovered a novel and specific peptide Mst1 inhibitor (termed Mst1 inhibitory peptide 120 (MIP120)) and made it cell permeable (termed TAT120) and 2) has established an ELISA-based high throughput method to accurately determine the kinase activity of Mst1. To our knowledge, MIP120 and TAT120 are the only compounds currently available inhibiting the kinase activity of Mst1. In the phase II STTR project, Vasade will provide unequivocal evidence showing that the Mst1 inhibitor is useful for the prevention of cardiac myocyte death by I/R in vivo and identify a refined lead compound for the development of peptide mimetic Mst1 inhibitors for treatment of I/R injury. Specific aims are: Aim 1 To determine the effect of TAT120 on the size of MI and cardiac myocyte apoptosis in response to I/R in vivo, thereby establishing the proof of concept for the use of Mst1 inhibitors to reduce I/R injury using the mouse and pig models of ischemia/reperfusion. Aim 2 To further improve the property of MIP120 /TAT120 as Mst1 inhibitors and to elucidate the structure- function relationship of MIP120/TAT120 for the development of better peptides or peptide mimetics This phase II study will provide strong proof of concept and refined lead compounds, which will be used for the development of peptide mimetic small molecule Mst1 inhibitors for the future clinical treatment of I/R injury in the heart.

Public Health Relevance:
Almost 20 million people suffer from ischemic heart diseases in US and one million patients develop myocardial infarction (MI) every year. Many patients develop heart failure even if they survive the acute event, which clearly indicates that current interventions are not sufficient to prevent myocardial cell death and resultant left ventricular (LV) dysfunction. The current investigation is aiming at generating a new class of medicine preventing ischemia/reperfusion (I /R) injury, which should have a large market opportunity and significant clinical importance.

Thesaurus Terms:
(8s-Cis)-10-[(3-Amino-2,3,6-Trideoxy-Alpha-L-Lyxo-Hexopyranosyl)Oxy]-7,8,9,10-Tetrahydro-6,8,11-Trihydroxy-8-(Hydroacetyl)-1-Methoxy-5,12-Naphthacenedione; 14-Hydroxydaunomycin; 5,12-Naphthacenedione, 10-((3-Amino-2,3,6-Trideoxy-Alpha-L-Lyxo-Hexopyranosyl)Oxy)-7,8,9,10-Tetrahydro-6,8,11-Trihydroxy-8-(Hydroxyacetyl)-1-Methoxy-, (8s-Cis)-; Acute; Adriamycine; Antimorphic Mutation; Apopain; Apoptosis; Apoptosis Pathway; Assay; Bioassay; Biologic Assays; Biological Assay; Casp-3; Casp3; Cpp-32; Cpp32; Cpp32 Protein; Cpp32b; Cpp32beta; Cardiac; Cardiac Failure Congestive; Cardiac Myocytes; Cardiac Infarction; Cardiocyte; Caspase 3, Apoptosis-Related Cysteine Protease; Cell Death; Cell Death, Programmed; Cells; Cessation Of Life; Clinical; Clinical Treatment; Congestive Heart Failure; Cysteine Protease Cpp32; Dox; Death; Development; Development Plans; Dominant Negative; Dominant-Negative Mutant; Dominant-Negative Mutation; Doxorubicin; Doxorubicina; Ec 2.7; Event; Family Suidae; Future; Goals; Grant; Htrpy; Heart; Heart Decompensation; Heart Failure, Congestive; Heart Failure; Heart Myocyte; Histones; Hydroxyl Daunorubicin; Hydroxyldaunorubicin; Hypertrophy; Injury; Intervention; Intervention Strategies; Investigation; Ischemia; Ischemia-Reperfusion Injury; Ischemic Heart; Ischemic Heart Disease; Ischemic Myocardium; Kinases; Knowledge; Lats2; Lats2 Gene; Lead; Left; Left Ventricular Dysfunction; Legal Patent; Mammals, Mice; Marketing; Mechanics; Mediating; Medicine; Methods; Mice; Modeling; Murine; Mus; Muscle Cells, Cardiac; Muscle Cells, Heart; Myocardial; Myocardial Infarct; Myocardial Infarction; Myocardial Ischemia; Myocytes, Cardiac; Nih; National Institutes Of Health; National Institutes Of Health (U.S.); Parp Cleavage Protease; Patents; Pathogenesis; Patients; Pb Element; Peptides; Phase; Phosphotransferases; Pigs; Play; Prevention; Property; Property, Loinc Axis 2; Reperfusion Damage; Reperfusion Injury; Reperfusion Therapy; Role; Sca-1; Srebp Cleavage Activity 1; Sttr; Science Of Medicine; Small Business Technology Transfer Research; Sterility; Stress; Structure-Activity Relationship; Suidae; Swine; Transgenic Mice; Transphosphorylases; United States National Institutes Of Health; Ventricular; Yama; Yama Protein; Abstracting; Base; Cardiac Failure; Cardiac Infarct; Cardiomyocyte; Caspase-3; Chemical Structure Function; Coronary Attack; Coronary Infarct; Coronary Infarction; Cysteine Protease P32; Heart Attack; Heart Infarct; Heart Infarct Sizing; Heart Infarction; Heart Infarction Sizing; Heart Ischemia; Heavy Metal Pb; Heavy Metal Lead; Improved; In Vivo; Inhibitor; Inhibitor/Antagonist; Interventional Strategy; Mimetics; Mitochondrial Dysfunction; Myocardial Infarct Sizing; Myocardial Infarction Sizing; Myocardial Ischemia/Hypoxia; Myocardium Ischemia; Necrocytosis; Novel; Overexpression; Phase 2 Study; Porcine; Preclinical Study; Prevent; Preventing; Public Health Relevance; Reperfusion; Response; Small Molecule; Social Role; Sterile; Structure Function Relationship; Suid; Trial Regimen; Trial Treatment