THERAPEUTIC OR PREVENTIVE AGENT FOR MYOCARDIAL INFARCTION, CARDIAC FIBROSIS, OR HEART FAILURE USING Htra3 AS THERAPEUTIC TARGET

A non-human mammalian heart failure model animal in which expression of serine protease HtrA3 in cardiac fibroblasts is reduced or inhibited.

A method for screening for an agent or a method for regulation of a DNA repair mechanism in a cardiac fibroblast, the method comprising:

• (A) a step of treating a cell in which expression of serine protease HtrA3 is reduced or inhibited with a test factor;
• and
• (B) a step of comparing the cell to an untreated control cell or a wild-type cells.

A method of diagnosing myocardial infarction, cardiac fibrosis, or heart failure, the method comprising:

• (E) a step of determining that a subject may suffer from myocardial infarction, cardiac fibrosis or heart failure in a case where an expression level of serine protease HtrA3 in a cardiac fibroblast of the subject is significantly reduced as compared with an expression level in a cardiac fibroblast of a healthy subject.

A non-human mammalian heart failure model animal with enhanced expression of insulin-like growth factor binding protein 7 (IGFBP7) in cardiac fibroblasts.

A method for screening for an agent or a method for treating or preventing myocardial infarction or heart failure, the method comprising:

• (F) a step of treating a cell with enhanced expression of insulin-like growth factor binding protein 7 (IGFBP7) with a test factor;
• and
• (G) a step of comparing the cell to an untreated control cell or a wild-type cell.

A method of diagnosing myocardial infarction or heart failure, the method comprising:

• (J) a step of determining that a subject may suffer from myocardial infarction or heart failure in a case where an expression level of insulin-like growth factor binding protein 7 (IGFBP7) in cardiac fibroblasts, cardiomyocytes, or blood of the subject is significantly increased as compared with an expression level in a cardiac fibroblast, a cardiomyocyte, or blood of a healthy subject.

A method of determining a severity level of myocardial infarction, or heart failure, the method comprising:

• (K) a step of determining a severity level of myocardial infarction or heart failure of a subject by comparing an expression level of insulin-like growth factor binding protein 7 (IGFBP7) in a cardiac fibroblast, a cardiomyocyte, or blood of the subject with an expression level in a cardiac fibroblast, a cardiomyocyte, or blood of a healthy subject or a past expression level of the subject.