Mitochondrial division in rat cardiomyocytes: An electron microscope study

Abstract

In cardiomyocytes of rats, two distinct mitochondrial division processes are in operation. The predominant process involves extension of a single crista until it spans the full width of a mitochondrion. Ingrowth of the outer membrane ultimately results in scission. The second division process involves "pinching", in which narrowing of the organelle at specific surface locations leads to its attenuation. When limiting membranes from opposite sides meet, mitochondrial fission ensues. When pinching is the operative mode, elements of sarcoplasmic reticulum always are associated with the membrane constrictions. The nuclear control mechanisms that determine which modality of mitochondrial division will prevail are unknown.

KLF2 and KLF4 control endothelial identity and vascular integrity

“…Brain and lungs were isolated from CRE and EC-DKO mice at day 6 after tamoxifen injection. Small pieces of the brain and lung tissue were fixed for 2 hours at room temperature by immersion in the freshly prepared triple aldehyde-DMSO (32). After rinsing in 0.1 M HEPES buffer (pH 7.3), they were postfixed in ferrocyanide-reduced osmium tetroxide.…”

Kruppel-like factor 4 is critical for transcriptional control of cardiac mitochondrial homeostasis

“…Small pieces of tissue from the LV free wall were fixed by sequential immersion in triple aldehyde-DMSO, ferrocyanide-reduced osmium tetroxide, and acidified uranyl acetate; dehydrated in ascending concentrations of ethanol; passed through propylene oxide; and embedded in Poly/Bed resin (Polysciences Inc., 21844-1). Thin sections were sequentially stained with acidified uranyl acetate, followed by a modification of Sato's triple lead stain, and examined with a JEOL 1200EX electron microscope (65).…”

Kruppel-like Factor 15 Is a Critical Regulator of Cardiac Lipid Metabolism

“…Mitochondrial protein concentration, citrate synthase activity, and oxygen consumption (using a Clark-type oxygen electrode at 30°C) were assayed as described previously (33,34). Mouse heart tissue was freshly dissected and rapidly processed for transmission electron microscopy as described previously (35).…”