Increased mitochondrial free Ca during ischemia is suppressed, but not eliminated by, germline deletion of the mitochondrial Ca uniporter.

Mitochondrial Ca overload is proposed to regulate cell death via opening of the mitochondrial permeability transition pore. It is hypothesized that inhibition of the mitochondrial Ca uniporter (MCU) will prevent Ca accumulation during ischemia/reperfusion and thereby reduce cell death. To address this, we evaluate mitochondrial Ca in ex-vivo-perfused hearts from germline MCU-knockout (KO) and wild-type (WT) mice using transmural spectroscopy.

Reduction of Mitochondrial RNase P in Skeletal and Heart Muscle Causes Muscle Degeneration, Cardiomyopathy, and Heart Arrhythmia.

In this study, we examine the cause and progression of mitochondrial diseases linked to the loss of mtRNase P, a three-protein complex responsible for processing and cleaving mitochondrial transfer RNAs (tRNA) from their nascent transcripts. When mtRNase P function is missing, mature mitochondrial tRNA levels are decreased, resulting in mitochondrial dysfunction. mtRNase P is composed of Mitochondrial RNase P Protein (MRPP) 1, 2, and 3.

Analysis of cardiac hypertrophy by microcomputerized tomography for genetic dissection of heart growth mechanisms.

Heart failure is often preceded by pathological cardiac hypertrophy, a thickening of the heart musculature driven by complex gene regulatory and signaling processes. The heart has great potential as a genetic model for deciphering the underlying mechanisms of cardiac hypertrophy. However, current methods for evaluating hypertrophy of the heart are laborious and difficult to carry out reproducibly.

Suppression of store-operated calcium entry causes dilated cardiomyopathy of the heart.

Store-operated Ca entry (SOCE) is an essential Ca signaling mechanism present in most animal cells. SOCE refers to Ca influx that is activated by depletion of sarco/endoplasmic reticulum (S/ER) Ca stores. The main components of SOCE are STIM and Orai.