Figure 4
MiR-324-5p inhibits mitochondrial fission and apoptosis in cardiomyocytes and in vivo. (a and b) miR-324-5p suppresses A/R-induced mitochondrial fission. Cardiomyocytes were transfected with miR-324-5p mimic or NC. After that, they were treated with A/R. Mitochondrial fission was assayed. (a) Scale bar, 20 μm (upper panel); scale bar, 5 μm (lower panel). *P<0.05 versus A/R alone. (c) MiR-324-5p suppresses A/R-induced apoptosis. Cardiomyocytes were transfected with miR-324-5p mimic or NC and were treated with A/R. Apoptosis was assayed by TUNEL. *P<0.05 versus A/R alone. (d) Analysis of miR-324-5p expression levels. Mice were subjected to I/R at indicated time and the expression of miR-324-5p was assayed by qRT-PCR. *P<0.05 versus sham or 0-min group. (e) MiR-324-5p attenuates Mtfr1 expression and mitochondrial fission upon I/R injury. Adult C57BL/6 mice received miR-324-5p mimic or mimic-NC for 3 days. They were then subjected to I/R. Mtfr1 levels were analyzed by immunoblot (upper panel). The percentage of mitochondrial fission was calculated (lower panel). *P<0.05 versus I/R alone. (f and g) MiR-324-5p attenuates apoptosis upon I/R injury. Mice were treated as described in e. Apoptosis was detected by TUNEL assay. TUNEL-positive cardiomyocyte nuclei (apoptotic cells) are green. Nuclei stained by DAPI showed blue. Cardiomyocytes were labeled with α-actinin. *P<0.05 versus I/R alone
