Differences in inflammation, MMP activation and collagen damage account for gender difference in murine cardiac rupture following myocardial infarction

Sex differences in myocardial infarction and rupture

“…Other cases of gender divergence in gene expression include the hepatic response to ethanol consumption in rats [18], and the sensitivity of murine hematopoietic stem cells to benzene intoxication [19]. An example of gender difference in the heart includes the genomic response to pressure overload, a condition in which male mice show a more robust over-expression of genes involved in immunity and inflammation than females [20], which is in agreement with the more pronounced inflammatory response found in male mice after MI as described here by Fang et al [2]. In addition, previous studies in rodents have documented a gender difference in cardiac remodeling following MI [21].…”

“…An additional study from the same authors showed that testosterone is also responsible for a higher rate of cardiac rupture due to higher inflammatory response in the same model of MI [29]. These data correlate with the observations by Fang et al of a higher rate of rupture in males compared to females, associated with higher inflammatory reaction and a more pronounced activation of MMP9 [2].…”

“…In the current study, Fang et al [2] confirm this gender difference in the risk of cardiac rupture after MI, and further delineate its mechanisms. The novelty brought by the present study relates to the fact that total collagen content does not differ between genders, however males are characterized by a 70% reduction in cross-linked collagen, which indicates more breakdown and therefore more fragility of the collagen network in males.…”

“…Understanding the molecular mechanisms leading to myocardial rupture therefore represents an important challenge for improving the short term prognosis of MI. In the present issue of the Journal, Fang and coauthors [2] investigate an intriguing aspect of the pathophysiology of this disease, which relates to the mechanisms underlying the gender differences in the rate of post-MI rupture.It is well documented that the incidence of acute MI varies according to both gender and age. The Framingham study, for example, has demonstrated that the incidence of acute MI is 2.5-fold higher in males than females before age 45, however, this gender difference disappears after 55 years of age [3].…”

“…Understanding the molecular mechanisms leading to myocardial rupture therefore represents an important challenge for improving the short term prognosis of MI. In the present issue of the Journal, Fang and coauthors [2] investigate an intriguing aspect of the pathophysiology of this disease, which relates to the mechanisms underlying the gender differences in the rate of post-MI rupture.…”