• Animals
• Female
• Humans
• Male
• Mice
• Brain/metabolism
• Brain/drug effects
• Brain/pathology
• Cannabidiol/pharmacology
• Cannabidiol/therapeutic use
• Disease Models, Animal
• Fibroblasts/drug effects
• Fibroblasts/metabolism
• Leigh Disease/drug therapy
• Leigh Disease/metabolism
• Leigh Disease/genetics
• Mice, Inbred C57BL
• Mitochondria/drug effects
• Mitochondria/metabolism
• Mitochondrial Diseases/drug therapy
• Mitochondrial Diseases/metabolism
• Neurons/drug effects
• Neurons/metabolism
• PPAR gamma/metabolism
• PPAR gamma/genetics

• ERC-2014-StG-638106 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council)
• LCF/PR/HR20/52400018. "la Caixa" Foundation (Caixa Foundation)
• H2020-MSCA-IF-2020-101030783, EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska-Curie Actions (H2020 Excellent Science - Marie Skłodowska-Curie Actions)
• H2020-MSCA-COFUND-2014-665919 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska-Curie Actions (H2020 Excellent Science - Marie Skłodowska-Curie Actions)
• H2020-MSCA-IF-2014-658352 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska-Curie Actions (H2020 Excellent Science - Marie Skłodowska-Curie Actions)

• Female
• Humans
• Infant, Newborn
• Pregnancy
• Chromatin/genetics
• Fatty Acids/metabolism
• gamma-Linolenic Acid/metabolism
• gamma-Linolenic Acid/pharmacology
• Gene Expression Regulation/drug effects
• Glucose/metabolism
• Heart/drug effects
• Heart/embryology
• Heart/growth & development
• Homeostasis
• In Vitro Techniques
• Milk, Human/chemistry
• Mitochondria/drug effects
• Mitochondria/metabolism
• Myocytes, Cardiac/drug effects
• Myocytes, Cardiac/metabolism
• Retinoid X Receptors/metabolism
• Transcription Factors/metabolism

• FKBP51
• immunophilin
• nuclear-mitochondrial shuttling
• phosphoamino acid

• continuous separation
• insulator-based dielectrophoresis
• mitochondria
• ratchet
• size-based separation

• Electrophoresis/methods
• Humans
• Microfluidic Analytical Techniques
• Organelles
• Particle Size
• Polystyrenes

• R01 GM127562 NIGMS NIH HHS

• ATP-Dependent Proteases/metabolism
• Animals
• Cells, Cultured
• DNA Polymerase gamma/genetics
• DNA Polymerase gamma/metabolism
• DNA Replication
• DNA, Mitochondrial/analysis
• Enzyme Stability/genetics
• HeLa Cells
• Holoenzymes/metabolism
• Humans
• Mice
• Mitochondrial Proteins/metabolism
• Mutation

• MC_UU_00015/8 Medical Research Council
• MC_UU_00015/5 Medical Research Council
• MC_UU_00015/4 Medical Research Council
• MC_UU_00015/7 Medical Research Council
• Telethon Foundation
• Fondation NRJ pour les Neurosciences - Institute de France Grant
• Associazione Luigi Comini Onlus
• Marie Sklodowska-Curie ITN-REMIX
• Swedish Research Council
• Swedish Cancer Foundation
• European Research Council
• Knut and Alice Wallenberg Foundation
• MRC Graduate Student Fellowship
• EMBO Installation Grant
• Bogazici University

• CFTR
• copper
• cystic fibrosis
• inflammation
• lung
• oxidative stress

• Apoptosis
• Cyclophilin A
• Immunophilin
• Mitochondria
• Trafficking
• p23

Aerobic glycolysis, discovered by Otto Warburg, is a hallmark of cancer metabolism even though not yet fully understood. The low activity of the cancerous pyruvate kinase isozyme (M2) is thought to play an important role by facilitating the conversion of glycolytic intermediates to other anabolic pathways to support tumors’ high proliferation rate.

Five breast cancer cell lines representing different molecular subtypes were used in this study where real time measurements of cellular bioenergetics and immunoblotting analysis of energy- and nutrient-sensing pathways were employed to investigate the potential effects of PKM2 allosteric activator (DASA-58) in glucose rewiring.

In this study, we show that DASA-58 can induce pyruvate kinase activity in breast cancer cells without affecting the overall cell survival. The drug is also able to reduce TXNIP levels (an intracellular glucose sensor) probably through depletion of upstream glycolytic metabolites and independent of AMPK and ER signaling. AMPK shows an induction in phosphorylation (T172) in response to treatment an effect that can be potentiated by combining DASA-58 with other metabolic inhibitors.

Altogether, the multifaceted metabolic reprogramming induced by DASA-58 in breast cancer cells increases their susceptibility to other therapeutics suggesting the suitability of the intracellular glucose sensor TXNIP as a marker of PK activity.

The online version contains supplementary material available at 10.1186/s40170-021-00239-8.

• AMPK
• Breast cancer
• Cancer metabolism
• Glycolysis
• Pyruvate kinase M2
• TXNIP

• Animals
• Ataxia/genetics
• Ataxia/metabolism
• Ataxia/pathology
• Carbon/metabolism
• Electron Transport
• Electron Transport Complex I/genetics
• Electron Transport Complex I/metabolism
• Fibroblasts/drug effects
• Fibroblasts/metabolism
• Fibroblasts/pathology
• Glutathione/metabolism
• Humans
• Mice
• Mice, Inbred C57BL
• Mitochondria/metabolism
• Mitochondria/pathology
• Mitochondrial Diseases/genetics
• Mitochondrial Diseases/metabolism
• Mitochondrial Diseases/pathology
• Muscle Weakness/genetics
• Muscle Weakness/metabolism
• Muscle Weakness/pathology
• Oxidoreductases Acting on Sulfur Group Donors/genetics
• Oxidoreductases Acting on Sulfur Group Donors/metabolism
• Skin/drug effects
• Skin/metabolism
• Skin/pathology
• Sulfides/metabolism
• Transcriptome
• Ubiquinone/analogs & derivatives
• Ubiquinone/deficiency
• Ubiquinone/genetics
• Ubiquinone/metabolism
• Ubiquinone/pharmacology
• Vitamins/pharmacology

• P01 HD080642 NICHD NIH HHS
• National Institute of Health
• University of Granada
• Muscular Dystrophy Association
• Ministerio de Ciencia e Innovación, Spain, and the ERDF

• Mpv17
• Opa1
• apoptosis
• focal segmental glomerulosclerosis
• mitochondrial DNA depletion
• mitochondrial cristae
• oxidative phosphorylation

• Animals
• Apoptosis/genetics
• DNA, Mitochondrial
• Disease Models, Animal
• Disease Susceptibility
• GTP Phosphohydrolases/genetics
• GTP Phosphohydrolases/metabolism
• Gene Expression
• Immunohistochemistry
• Kidney Diseases/etiology
• Kidney Diseases/metabolism
• Kidney Diseases/pathology
• Membrane Proteins/deficiency
• Mice
• Mice, Knockout
• Mitochondria/genetics
• Mitochondria/metabolism
• Mitochondrial Proteins/genetics
• Mitochondrial Proteins/metabolism
• Models, Biological
• Oxidative Phosphorylation
• Podocytes/metabolism
• Podocytes/pathology
• Podocytes/ultrastructure

• MC_U105184326 Medical Research Council
• MC_UU_00015/5 Medical Research Council

The age-dependent declines of skeletal muscle and cognitive functions often coexist in elderly subjects. The underlying pathophysiological mechanisms share common features of mitochondrial dysfunction, which plays a central role in the development of overt sarcopenia and/or dementia. Dietary supplementation with formulations of essential and branched-chain amino acids (EAA-BCAA) is a promising preventive strategy because it can preserve mitochondrial biogenesis and function. The senescence-accelerated mouse prone 8 (SAMP8) is considered an accurate model of age-related muscular and cognitive alterations. Hence, we aimed to investigate the progression of mitochondrial dysfunctions during muscular and cognitive aging of SAMP8 mice and to study the effects of a novel EAA-BCAA-based metabolic modulator on these changes. We evaluated body condition, motor endurance, and working memory of SAMP8 mice at 5, 9, 12, and 15 months of age. Parallel changes in protein levels of mitochondrial respiratory chain subunits, regulators of mitochondrial biogenesis and dynamics, and the antioxidant response, as well as respiratory complex activities, were measured in the quadriceps femoris and the hippocampus. The same variables were assessed in 12-month-old SAMP8 mice that had received dietary supplementation with the novel EAA-BCAA formulation, containing tricarboxylic acid cycle intermediates and co-factors (PD-0E7, 1.5 mg/kg/body weight/day in drinking water) for 3 months. Contrary to untreated mice, which had a significant molecular and phenotypic impairment, PD-0E7-treated mice showed preserved healthy body condition, muscle weight to body weight ratio, motor endurance, and working memory at 12 months of age. The PD-0E7 mixture increased the protein levels and the enzymatic activities of mitochondrial complex I, II, and IV and the expression of proliferator-activated receptor γ coactivator-1α, optic atrophy protein 1, and nuclear factor, erythroid 2 like 2 in muscles and hippocampi. The mitochondrial amyloid-β-degrading pitrilysin metallopeptidase 1 was upregulated, while amyloid precursor protein was reduced in the hippocampi of PD-0E7 treated mice. In conclusion, we show that a dietary supplement tailored to boost mitochondrial respiration preserves skeletal muscle and hippocampal mitochondrial quality control and health. When administered at the early onset of age-related physical and cognitive decline, this novel metabolic inducer counteracts the deleterious effects of precocious aging in both domains.

• aging
• cognitive impairment
• essential amino acids
• mitochondrial biogenesis
• mitochondrial respiratory chain
• proteostasis
• sarcopenia
• tricarboxylic acid cycle

• AAV
• Leigh syndrome
• Ndufs4
• OXPHOS
• PHP.B
• complex I
• gene therapy
• mitochondrial diseases

Respirometry is the gold standard measurement of mitochondrial oxidative function, as it reflects the activity of the electron transport chain complexes working together. However, the requirement for freshly isolated mitochondria hinders the feasibility of respirometry in multi‐site clinical studies and retrospective studies. Here, we describe a novel respirometry approach suited for frozen samples by restoring electron transfer components lost during freeze/thaw and correcting for variable permeabilization of mitochondrial membranes. This approach preserves 90–95% of the maximal respiratory capacity in frozen samples and can be applied to isolated mitochondria, permeabilized cells, and tissue homogenates with high sensitivity. We find that primary changes in mitochondrial function, detected in fresh tissue, are preserved in frozen samples years after collection. This approach will enable analysis of the integrated function of mitochondrial Complexes I to IV in one measurement, collected at remote sites or retrospectively in samples residing in tissue biobanks.

• frozen tissue
• methodology
• mitochondrial content
• mitochondrial uncoupled respiration
• oxygen consumption

• Bioenergetics
• Genetic diseases
• Genetics
• Mitochondria
• Ophthalmology

• Animals
• DNA Polymerase gamma/physiology
• DNA Replication
• DNA, Mitochondrial/genetics
• DNA-Binding Proteins/chemistry
• DNA-Binding Proteins/genetics
• Exome
• Female
• Humans
• Male
• Mitochondria/metabolism
• Mitochondrial Proteins/chemistry
• Mitochondrial Proteins/genetics
• Mutation
• Optic Atrophies, Hereditary/etiology
• Optic Atrophies, Hereditary/genetics
• Zebrafish

• I 2741 Austrian Science Fund FWF
• Z01 ES065078 Intramural NIH HHS

Cyclic adenosine monophosphate (cAMP) is a ubiquitous secondary messenger that plays a central role in endocrine tissue function, particularly in the synthesis of steroid hormones. The intracellular concentration of cAMP is regulated through its synthesis by cyclases and its degradation by cyclic nucleotide phosphodiesterases (PDEs). Although the expression and activity of PDEs impact the specificity and the amplitude of the cAMP response, it is becoming increasingly clear that the sub-cellular localization of PDE emphasizes the spatial regulation of the cell signalling processes that are essential for normal cellular function. We first examined the expression of PDE8A in porcine ovarian cells. PDE8A is expressed in granulosa cells, cumulus cells and oocytes. Second, we assessed the mitochondrial sub-cellular localization of PDE8A. Using western blotting with isolated mitochondrial fractions from granulosa cells and cumulus-oocyte complexes revealed immuno-reactive bands. PDE assay of isolated mitochondrial fractions from granulosa cells measured specific PDE8 cAMP-PDE activity as PF-04957325-sensitive. The immune-reactive PDE8A signal and MitoTracker labelling co-localized supporting mitochondrial sub-cellular localization of PDE8A, which was confirmed using immuno-electron microscopy. Finally, the effect of PDE8 on progesterone production was assessed during the in-vitro maturation of cumulus-oocyte complexes. Using PF-04957325, we observed a significant increase (P < 0.05) in progesterone secretion with follicle-stimulating hormone (FSH). Active mitochondria stained with MitoTracker orange CMTMRos were also increased by the specific PDE8 inhibitor supporting its functional regulation. In conclusion, we propose the occurrence of mitochondrial sub-cellular localization of PDE8A in porcine granulosa cells and cumulus cells. This suggests that there is potential for new strategies for ovarian stimulation and artificial reproductive technologies, as well as the possibility for using new media to improve the quality of oocytes.

The vast majority of mitochondrial disorders have limited the clinical management to palliative care. Rapamycin has emerged as a potential therapeutic drug for mitochondrial diseases since it has shown therapeutic benefits in a few mouse models of mitochondrial disorders. However, the underlying therapeutic mechanism is unclear, the minimal effective dose needs to be defined and whether this therapy can be generally used is unknown.

We have evaluated whether low and high doses of rapamycin administration may result in therapeutic effects in a mouse model (Coq9^R239X) of mitochondrial encephalopathy due to CoQ deficiency. The evaluation involved phenotypic, molecular, image (histopathology and MRI), metabolomics, transcriptomics and bioenergetics analyses.

Low dose of rapamycin induces metabolic changes in liver and transcriptomics modifications in midbrain. The high dose of rapamycin induces further changes in the transcriptomics profile in midbrain due to the general inhibition of mTORC1. However, neither low nor high dose of rapamycin were able to improve the mitochondrial bioenergetics, the brain injuries and the phenotypic characteristics of Coq9^R239X mice, resulting in the lack of efficacy for increasing the survival.

These results may be due to the lack of microgliosis-derived neuroinflammation, the limitation to induce autophagy, or the need of a functional CoQ-junction. Therefore, the translation of rapamycin therapy into the clinic for patients with mitochondrial disorders requires, at least, the consideration of the particularities of each mitochondrial disease.

Supported by the grants from “Fundación Isabel Gemio - Federación Española de Enfermedades Neuromusculares – Federación FEDER” (TSR-1), the NIH (P01HD080642) and the ERC (Stg-337327).

• CoQ deficiency
• Mitochondrial diseases
• Mitochondrial encephalopathy
• Mouse model
• mTORC1

• Apoptosis/genetics
• Cell Death/drug effects
• Cell Line
• Cell Survival/drug effects
• DNA, Mitochondrial/genetics
• Humans
• Mitochondria/physiology
• Mitophagy/physiology
• Mutation
• Optic Atrophy, Hereditary, Leber/genetics
• Optic Atrophy, Hereditary, Leber/physiopathology
• Oxidative Stress/physiology

• R01 GM109434 NIGMS NIH HHS
• R01 GM130129 NIGMS NIH HHS

• 2,4‐dihydroxybenzoic acid
• Q synthome
• astrogliosis
• mitochondrial encephalopathy
• spongiosis

• Animals
• Brain/pathology
• Brain/physiopathology
• Disease Models, Animal
• Energy Metabolism
• Histocytochemistry
• Hydroxybenzoates/administration & dosage
• Mice
• Mitochondrial Encephalomyopathies/drug therapy
• Mitochondrial Encephalomyopathies/pathology
• Neuroprotective Agents/administration & dosage
• Salicylic Acid/administration & dosage
• Survival Analysis
• Treatment Outcome
• Ubiquinone/analogs & derivatives
• Ubiquinone/analysis
• Ubiquinone/deficiency
• Ubiquinone/genetics
• Ubiquinone/metabolism

• P01 HD080642 NICHD NIH HHS

• autophagy
• lysosomal biogenesis
• mTORC1
• mitochondrial disease
• rapamycin

• Genome editing
• Leigh syndrome
• Mitochondrial disease
• Pig
• SURF1 KO

• Animals
• Animals, Genetically Modified
• Animals, Newborn
• Behavior, Animal
• CRISPR-Cas Systems
• Cells, Cultured
• Central Nervous System/growth & development
• Disease Models, Animal
• Down-Regulation
• Electron Transport Complex IV/metabolism
• Female
• Fibroblasts
• Gene Editing
• Gene Knockout Techniques
• Humans
• Jejunum/pathology
• Leigh Disease/genetics
• Leigh Disease/pathology
• Male
• Membrane Proteins/genetics
• Mitochondria/pathology
• Mitochondrial Proteins/genetics
• Muscle, Skeletal/cytology
• Muscle, Skeletal/pathology
• Nuclear Transfer Techniques
• Primary Cell Culture
• Sus scrofa/genetics

• MC_U105674181 Medical Research Council
• MC_UP_1002/1 Medical Research Council
• MC_UU_00015/5 Medical Research Council
• MC_UU_00015/8 Medical Research Council

Hydroxytyrosol (HT) is a polyphenol found in olive oil that is known for its antioxidant effects. Here, we aimed to describe the effects of a low and high HT dose on the physical running capacity and redox state in both sedentary and exercised rats.

Male Wistar rats were allocated into 6 groups: sedentary (SED; n = 10); SED consuming 20 mg/kg/d HT (SED20; n = 7); SED consuming 300 mg/kg/d HT (SED300; n = 7); exercised (EXE; n = 10); EXE consuming 20 mg/kg/d HT (EXE20; n = 10) and EXE consuming 300 mg/kg/d HT (EXE300; n = 10). All the interventions lasted 10 weeks; the maximal running velocity was assessed throughout the study, whereas daily physical work was monitored during each training session. At the end of the study, the rats were sacrificed by bleeding. Hemoglobin (HGB) and hematocrit (HCT) were measured in the terminal blood sample. Moreover, plasma hydroperoxide (HPx) concentrations were quantified as markers of lipid peroxidation.

In sedentary rats, HT induced an antioxidant effect in a dose-dependent manner without implications on running performance. However, if combined with exercise, the 300 mg/kg/d HT dosage exhibited a pro-oxidant effect in the EXE300 group compared with the EXE and EXE20 groups. The EXE20 rats showed a reduction in daily physical work and a lower maximal velocity than the EXE and EXE300 rats. The higher physical capacity exhibited by the EXE300 group was achieved despite the EXE300 rats expressing lower HGB levels and a lower HCT than the EXE20 rats.

Our results suggest that a high HT dose induces a systemic pro-oxidant effect and may prevent the loss of performance that was observed with the low HT dose.

• Antioxidants
• Exercise
• Hemoglobin
• Oxidative stress
• Polyphenols
• ROS

• PARK2
• PINK1
• autophagy
• mitochondria
• mitophagy
• renal ischemia-reperfusion

Mitochondria are essential for the onset of hypoxia-induced pulmonary vasoconstriction and pulmonary vascular-remodeling, two major aspects underlying the development of pulmonary hypertension, an incurable disease. However, hypoxia induces relaxation of systemic arteries such as femoral arteries and mitochondrial heterogeneity controls the distinct responses of pulmonary versus femoral artery smooth muscle cells to hypoxia in vitro. The aim of this study was to determine whether mitochondrial heterogeneity can be experimentally exploited in vivo for a potential treatment against pulmonary hypertension. The intact mitochondria were transplanted into Sprague-Dawley rat pulmonary artery smooth muscle cells in vivo via intravenous administration. The immune-florescent staining and ultrastructural examinations on pulmonary arteries confirmed the intracellular distribution of exogenous mitochondria and revealed the possible mitochondrial transfer from pulmonary artery endothelial cells into smooth muscle cells in part through their intercellular space and intercellular junctions. The transplantation of mitochondria derived from femoral artery smooth muscle cells inhibited acute hypoxia-triggered pulmonary vasoconstriction, attenuated chronic hypoxia-induced pulmonary vascular remodeling, and thus prevented the development of pulmonary hypertension or cured the established pulmonary hypertension in rats exposed to chronic hypoxia. Our findings suggest that mitochondrial transplantation possesses potential implications for exploring a novel therapeutic and preventive strategy against pulmonary hypertension.

• Pathology Section
• hypoxia
• mitochondria
• pulmonary hypertension
• transplantation
• vasoconstriction

Cytochrome c oxidase of the mitochondrial oxidative phosphorylation system reduces molecular oxygen with redox equivalent-derived electrons. The conserved mitochondrial-encoded COX1- and COX2-subunits are the heme- and copper-center containing core subunits that catalyze water formation. COX1 and COX2 initially follow independent biogenesis pathways creating assembly modules with subunit-specific, chaperone-like assembly factors that assist in redox centers formation. Here, we find that COX16, a protein required for cytochrome c oxidase assembly, interacts specifically with newly synthesized COX2 and its copper center-forming metallochaperones SCO1, SCO2, and COA6. The recruitment of SCO1 to the COX2-module is COX16- dependent and patient-mimicking mutations in SCO1 affect interaction with COX16. These findings implicate COX16 in Cu_A-site formation. Surprisingly, COX16 is also found in COX1-containing assembly intermediates and COX2 recruitment to COX1. We conclude that COX16 participates in merging the COX1 and COX2 assembly lines.

• Copper chaperone
• Cytochrome c oxidase
• Mitochondrial oxidative phosphorylation
• biochemistry
• cell biology
• human
• mitochondria
• mitochondrial diseases
• protein assembly

• Animals
• Brain/metabolism
• Dependovirus/genetics
• Electron Transport Complex I/genetics
• Electron Transport Complex I/metabolism
• Genetic Therapy/methods
• Genetic Vectors/genetics
• Humans
• Injections, Intravenous
• Leigh Disease/genetics
• Leigh Disease/therapy
• Mice
• Mice, Inbred C57BL
• Phenotype

• 322424 European Research Council
• MC_UP_1002/1 Medical Research Council
• MC_UU_00015/5 Medical Research Council
• MC_UU_00015/8 Medical Research Council

• COX
• SQR
• blood pressure
• glutathione
• mitochondrial disease

Cardiac progenitors are specified early in development and progressively differentiate and mature into fully functional cardiomyocytes. This process is controlled by an extensively studied transcriptional program. However, the regulatory events coordinating the progression of such program from development to maturation are largely unknown. Here, we show that the genome organizer CTCF is essential for cardiogenesis and that it mediates genomic interactions to coordinate cardiomyocyte differentiation and maturation in the developing heart. Inactivation of Ctcf in cardiac progenitor cells and their derivatives in vivo during development caused severe cardiac defects and death at embryonic day 12.5. Genome wide expression analysis in Ctcf mutant hearts revealed that genes controlling mitochondrial function and protein production, required for cardiomyocyte maturation, were upregulated. However, mitochondria from mutant cardiomyocytes do not mature properly. In contrast, multiple development regulatory genes near predicted heart enhancers, including genes in the IrxA cluster, were downregulated in Ctcf mutants, suggesting that CTCF promotes cardiomyocyte differentiation by facilitating enhancer-promoter interactions. Accordingly, loss of CTCF disrupts gene expression and chromatin interactions as shown by chromatin conformation capture followed by deep sequencing. Furthermore, CRISPR-mediated deletion of an intergenic CTCF site within the IrxA cluster alters gene expression in the developing heart. Thus, CTCF mediates local regulatory interactions to coordinate transcriptional programs controlling transitions in morphology and function during heart development.

Properly regulated gene expression in time and space during development and differentiation requires not only transcriptional inputs, but also specific structuring of the chromatin. CTCF is a DNA binding factor that is believed to be critical for this process through binding to tens of thousands of sites across the genome. Despite the knowledge gained in recent years on the role of CTCF in genome organization, its functions in vivo are poorly understood. To address this issue, we studied the effect of genetically deleting CTCF in differentiating cardiomyocytes at early stages of mouse development. Surprisingly only a fraction of genes change their expression when CTCF is removed. Importantly, misregulated genes control opposing genetic programs in charge of development and patterning on one hand, and cardiomyocyte maturation on the other. This imbalance leads to faulty mitochondria and incorrect expression of cardiac patterning genes, and subsequent embryonic lethality. Our results suggest that CTCF is not necessary for maintenance of global genome structure, but coordinates dynamic genetic programs controlling phenotypic transitions in developing cells and tissues.

• Animals
• CCCTC-Binding Factor
• Cell Differentiation/genetics
• Chromatin/genetics
• Embryonic Development/genetics
• Enhancer Elements, Genetic
• Gene Expression Regulation, Developmental
• Heart/embryology
• Heart/growth & development
• Heart Ventricles/embryology
• Heart Ventricles/growth & development
• Mice
• Mitochondria/genetics
• Mitochondria/metabolism
• Organogenesis/genetics
• Promoter Regions, Genetic
• Protein Binding
• Repressor Proteins/genetics
• Transcriptional Activation/genetics

• Ministerio de Economía y Competitividad
• Consejería de Educación, Juventud y Deporte, Comunidad de Madrid
• Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía
• Hospital for Sick Children
• Universidad Pablo de Olavide (ES)
• Fundacion ProCNIC
• Heart and Stroke Foundation of Canada
• Natural Sciences and Engineering Research Council of Canada
• Canadian Institutes of Health Research