Downregulation in GATA4 and Downstream Structural and Contractile Genes in the db/db Mouse Heart

Figure 3

GATA4 is localized in the cell nuclei of cardiomyocytes of 2-day-old rats (a). GATA4 mRNA is expression is similar to that seen in control hearts (b). However, as illustrated in (c), protein expression of GATA4 is downregulated in db/db hearts (c). GATA4 was present in nuclei of the cells expressing cardiomyocyte marker, troponin C (d). Hearts from db/db mice showed a tendency toward a reduced weight (d), but cardiomyocyte surface was increased in db/db hearts (Figure 3e2) compared with control hearts (Figure 3e1). Figure (e3) shows that cardiomyocyte surface area, expressed as μm², was significantly increased in db/db hearts compared with control hearts. Values are expressed as mean ± SEM obtained from 2 separate experiments each performed with 5 hearts. db/⁺, control mice; db/db, diabetic mice. ^∗𝑃<0.05.