Project description:We characterized the metabolic and cardiac mitochondrial function in a mouse model of non-ischemic HF. Inhibition of nitric oxide synthesis and hypertension, which often present together, are two important risk factors in human non-ischemic HF. Compared with L-NAME L-NG-Nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis or Angiotensin II (AngII), a hypertensive agent treatment alone, L-NAME+AngII induced the most severe HF phenotype characterized by edema, hypertrophy, fibrosis, increased blood pressure and reduced ejection fractions. L-NAME+AngII treated mice had robust deterioration of cardiac mitochondrial function we observed. Microarray analyses revealed majority of the gene changes attributed to the combination of L-NAME+AngII. Pathway analyses indicated significant changes in metabolic pathways such as mitochondrial oxidative phosphorylation, fatty acid metabolism and tricarboxylic acid pathways etc.in L-NAME+AngII hearts. We conclude that combination of L-NAME+AngII exacerbates cardiac contractile and mitochondrial functional de-regulation compared with L-NAME and AngII alone, resulting in non-ischemic HF. This model of heart failure may be highly valuable in studying mechanisms and treatments for non-ischemic heart failure.
Project description:We characterized the metabolic and cardiac mitochondrial function in a mouse model of non-ischemic HF. Inhibition of nitric oxide synthesis and hypertension, which often present together, are two important risk factors in human non-ischemic HF. Compared with L-NAME L-NG-Nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis or Angiotensin II (AngII), a hypertensive agent treatment alone, L-NAME+AngII induced the most severe HF phenotype characterized by edema, hypertrophy, fibrosis, increased blood pressure and reduced ejection fractions. L-NAME+AngII treated mice had robust deterioration of cardiac mitochondrial function we observed. Microarray analyses revealed majority of the gene changes attributed to the combination of L-NAME+AngII. Pathway analyses indicated significant changes in metabolic pathways such as mitochondrial oxidative phosphorylation, fatty acid metabolism and tricarboxylic acid pathways etc.in L-NAME+AngII hearts. We conclude that combination of L-NAME+AngII exacerbates cardiac contractile and mitochondrial functional de-regulation compared with L-NAME and AngII alone, resulting in non-ischemic HF. This model of heart failure may be highly valuable in studying mechanisms and treatments for non-ischemic heart failure. Twelve week-old C57BL6 male mice were randomly assigned to 4 groups: 1. Control, 2. L-NAME treatment, 3. AngII treatment, 4. L-NAME+AngII treatment.L-NAME (0.3 mg/ml with 1% NaCl) was administered in drinking water. AngII (0.7 mg/kg/day) was administered via subcutaneous micro-osmotic pumps. L-NAME and AngII were administered to mice for 5 weeks and 4 weeks in combination to induce HF or alone to study the effects of the individual agents.
Project description:Muscle tissue was longitudinally characterized histologically for electron transport function by staining 1mm of quadriceps muscle at 70 micron intervals for the activities of two complexes in the mitochondrial electron transport chain, Cytochrome C Oxidase and Succinate Dehydrogenase. Unstained serial cryosections were prepared for Laser Capture Microdissection. Target cells from the serial sections were isolated and pooled for RNA extraction, amplification and hybridization on Affymetrix microarrays. We selected homogeneous populations of muscle fibers for expression profiling based upon the presence/absence of electron transport dysfunction caused by the somatic accumulation of mitochondrial DNA deletion mutations. The design of this experiment is limited by the source tissue which is individually identified cells harboring intracellular clonal expansions of mitochondrial DNA deletion mutations. These unique and rare cells were identified in rat Vastus lateralis tissue in an aged 36-month old F344xBN F1 hybrid rat by exhaustive serial sectioning and subsequent histological characterization. Unstained serial sections where isolated by LCM and the purified RNA was amplified by 2 rounds of RNA based transcription prior to fragmentation and hybridization on rat genome affymetrix chips. Two populations of cells were analyzed, Electron transport deficient and normal control cells from the same animal.
Project description:Mitochondrial biogenesis is regulated by signaling pathways sensitive to extracellular conditions and to the internal environment of the cell. We found that deletion of protein phosphatase 2A (PP2A) or of protein phosphatase 6 (PP6) diminishes the nuclear transcriptional response associated with mtDNA damage. Six samples were analyzed to determine message RNA levels.
Project description:Serine-rich splicing factor 3 (SRSF3) was recently reported as being necessary to preserve RNA stability via an mTOR mechanism in a cardiac mouse model in adulthood. Here, we demonstrate the link between Srsf3 and mitochondrial integrity in an embryonic cardiomyocyte-specific Srsf3 conditional knockout (cKO) mouse model. Fifteen-day-old Srsf3 cKO mice showed dramatically reduced (below 50%) survival and reduced the left ventricular systolic performance, and histological analysis of these hearts revealed a significant increase in cardiomyocyte size, confirming the severe remodeling induced by Srsf3 deletion. RNA-seq analysis of the hearts of 5-day-old Srsf3 cKO mice revealed early changes in expression levels and alternative splicing of several transcripts related to mitochondrial integrity and oxidative phosphorylation. Likewise, the levels of several protein complexes of the electron transport chain decreased, and mitochondrial complex I-driven respiration of permeabilized cardiac muscle fibers from the left ventricle was impaired. Furthermore, transmission electron microscopy analysis showed disordered mitochondrial length and cristae structure. Together with its indispensable role in the physiological maintenance of mouse hearts, these results highlight the previously unrecognized function of Srsf3 in regulating the mitochondrial integrity.
2021-06-23 | GSE151168 | GEO
Project description:Mitochondrial DNA deletion detection from human tissues