The present inventors have shown that an HMGB1 fragment peptide having a specific amino acid sequence has an effect of improving cardiac function, suppressing cardiomyocyte hypertrophy, suppressing myocardial fibrosis, and promoting angiogenesis in an animal model of dilated cardiomyopathy Even in animal models of ischemic cardiomyopathy caused by old myocardial infarction, the specific HMGB1 fragment peptide improves cardiac function, suppresses cardiac expansion, suppresses cardiomyocyte hypertrophy, suppresses myocardial fibrosis, and It has been found that the effect of promoting angiogenesis is demonstrated, and that the specific HMGB1 fragment peptide exhibits an effect of suppressing cardiomyocyte hypertrophy and an effect of suppressing myocardial fibrosis in an animal model of hypertensive cardiomyopathy. Based on these findings, a pharmaceutical composition for preventing and / or treating cardiomyopathy and old myocardial infarction and chronic heart failure resulting therefrom, comprising an HMGB1 fragment peptide having a specific amino acid sequence, is provided.本発明者らは、特定のアミノ酸配列を有するHMGB1断片ペプチドが、拡張型心筋症の動物モデルにおいて心機能の改善、心筋細胞肥大の抑制、心筋線維化の抑制、および血管新生促進の効果を示すこと、陳旧性心筋梗塞に起因する虚血性心筋症の動物モデルにおいても、当該特定のHMGB1断片ペプチドが心機能の改善、心拡大の抑制、心筋細胞肥大の抑制、心筋線維化の抑制、および血管新生促進の効果を示すこと、並びに、高血圧性心筋症の動物モデルにおいて、当該特定のHMGB1断片ペプチドが心筋細胞肥大の抑制および心筋線維化の抑制効果を示すことを見出した。これら知見に基づき、特定のアミノ酸配列を有するHMGB1断片ペプチドを含有する、心筋症および陳旧性心筋梗塞ならびにこれらに起因する慢性心不全の予防および／または治療のための医薬組成物を提供する。
