Dataset Information

Targeted metabolomic profiling of retinas from WT and Rho-Cre/Mfn1flx/flx/Mfn2flx/flx mice

ABSTRACT: Mitochondria are dynamic organelles that undergo continuous morphological changes, yet exhibit unique, cell-type-specific structures. In rod photoreceptor cells of the retina, these structures include elongated mitochondria in the inner segments and a distinct, large, circular mitochondrion in each presynaptic terminal. The mechanisms underlying the establishment and maintenance of these specialized mitochondrial morphologies, along with their functional significance, are not well understood. Here, we investigate the roles of mitochondrial fusion proteins mitofusin 1 (MFN1) and mitofusin 2 (MFN2) in shaping these structures and maintaining photoreceptor cell health. Rod photoreceptor cell-specific ablation of MFN1 and MFN2 resulted in mitochondrial fragmentation by one month of age, suggesting that mitochondrial fusion is essential for the development of photoreceptor cell-specific mitochondrial structures. Notably, the layer structures of the retina examined by light microscopy appeared unaffected at this age. Following this time period, significant photoreceptor cell degeneration occurred by three months of age. Furthermore, we showed that impaired mitochondrial fusion perturbed the balance of proteins involved in glycolysis, oxidative phosphorylation (OXPHOS), and β-oxidation, highlighting the critical role of mitochondrial fusion in ensuring the proper levels of proteins necessary for optimal energy metabolism. Additionally, we identified upregulation of cellular stress pathways such as endoplasmic reticulum (ER) stress and unfolded protein response (UPR), which arise in response to energy deprivation, and cytoprotective biosynthetic pathways mediated by CCAAT/enhancer-binding protein gamma (C/EBPγ) and mammalian target of rapamycin complex 1 (mTORC1) signaling. In summary, our findings indicate that mitochondrial fusion through MFN1 and MFN2 is vital for the development of unique mitochondrial structures and proper energy production, underscoring the fundamental importance of mitochondrial dynamics in photoreceptor cell function and survival.

INSTRUMENT(S): Liquid Chromatography MS - alternating - hilic

PROVIDER: MTBLS12512 | MetaboLights | 2026-03-12

REPOSITORIES: MetaboLights

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	metabolomics_raw_data_1.xml	Xml
	metabolomics_raw_data_10.xml	Xml
	metabolomics_raw_data_2.xml	Xml
	metabolomics_raw_data_3.xml	Xml
	metabolomics_raw_data_4.xml	Xml

Items per page:

1 - 5 of 24

Similar Datasets

Project description:Mitochondria are dynamic organelles that undergo continuous morphological changes, yet exhibit unique, cell-type-specific structures. In rod photoreceptor cells of the retina, these structures include elongated mitochondria in the inner segments and a distinct, large, circular mitochondrion in each presynaptic terminal. The mechanisms underlying the establishment and maintenance of these specialized mitochondrial morphologies, along with their functional significance, are not well understood. Here, we investigate the roles of mitochondrial fusion proteins mitofusin 1 (MFN1) and mitofusin 2 (MFN2) in shaping these structures and maintaining photoreceptor cell health. Rod photoreceptor cell-specific ablation of MFN1 and MFN2 resulted in mitochondrial fragmentation by one month of age, suggesting that mitochondrial fusion is essential for the development of photoreceptor cell-specific mitochondrial structures. Notably, the layer structures of the retina examined by light microscopy appeared unaffected at this age. Following this time period, significant photoreceptor cell degeneration occurred by three months of age. Furthermore, we showed that impaired mitochondrial fusion perturbed the balance of proteins involved in glycolysis, oxidative phosphorylation (OXPHOS), and β-oxidation, highlighting the critical role of mitochondrial fusion in ensuring the proper levels of proteins necessary for optimal energy metabolism. Additionally, we identified upregulation of cellular stress pathways such as endoplasmic reticulum (ER) stress and unfolded protein response (UPR), which arise in response to energy deprivation, and cytoprotective biosynthetic pathways mediated by CCAAT/enhancer-binding protein gamma (C/EBPγ) and mammalian target of rapamycin complex 1 (mTORC1) signaling. In summary, our findings indicate that mitochondrial fusion through MFN1 and MFN2 is vital for the development of unique mitochondrial structures and proper energy production, underscoring the fundamental importance of mitochondrial dynamics in photoreceptor cell function and survival.

Project description:Mitochondrial diseases are caused by dysfunction of the mitochondria, which are specialized compartments that are present in every cell of the body except red blood cells. Mitochondria generate more than 90% of the energy that the body needs to sustain life and support growth. When they fail, less and less energy is generated within the cell. This injures the cell and can cause its death. If this process is repeated throughout the body, whole organ systems begin to fail, and the life of the person in whom this is happening is severely compromised. Mitochondrial diseases primarily affect children, but adult onset is becoming more and more common. Mitochondrial diseases are probably the most diverse human disorders at every level: clinical, biochemical, and genetic. Some affect only the nervous system but most affect many body systems, including the brain, heart, liver, skeletal muscles, kidney, and the endocrine and respiratory systems. Although mitochondrial disorders vary in severity, they are usually progressive, and often crippling. They can cause paralysis, seizures, mental retardation, dementia, hearing loss, blindness, weakness and premature death. Because of the range of symptoms and the frequent involvement of multiple body systems, mitochondrial diseases can be a great challenge to diagnose. Even when accurately diagnosed, they pose an even more formidable challenge to treat, as there are very few therapies and most are only partially effective. About this Study The first objective of this study is to establish a clinical registry of patients with suspected or confirmed mitochondrial diseases. We are collecting medical and family history, diagnostic test results, and prospective medical information for these patients and, using agreed procedures developed by the leading research clinicians in the field, providing, for the first time, standardized diagnoses of these complex disorders for the patients. The clinical information we collect from the participants will be used to learn about the spectrum of mitochondrial disorders and their prevalence. We will also develop studies which allow us to better understand how these diseases progress, which we do not understand well enough. When we begin clinical trials for mitochondrial diseases, patients enrolled in the registry who are identified as potentially eligible will be offered enrollment. Patients will only be included in studies if they give their consent in advance. The second objective of this study is to establish a biorepository for specimens and DNA from patients with mitochondrial diseases, in order to make materials easily available to consortium researchers.

Project description:Mitochondria are highly dynamic organelles undergoing fusion, fission and degradation. Although mitochondria are known to be essential for cellular metabolism, it is not fully understood how mitochondrial dynamics affect cellular metabolism. We previously identified a mouse gene, transmembrane protein 135 (TMEM135) that plays a role in the regulation of mitochondrial dynamics. Mice with mutant Tmem135 (Tmem135FUN025/FUN025) show accelerated aging phenotypes and age-related pathologies in the retina including the retinal pigment epithelium (RPE). We also generated a transgenic mouse line globally overexpressing the Tmem135 gene (Tmem135 TG). In several tissues and cells that we studied such as the retina, heart and fibroblast cells, we observed that the Tmem135 mutation causes elongated mitochondria, while over-expression of Tmem135 results in fragmented mitochondria. These unique mouse models allow us to test how abnormal mitochondrial dynamics affect metabolic signatures of tissues and cells. In this study, we identified metabolic changes in primary RPE cell cultures as well as tissues isolated from Tmem135FUN025/FUN025 mice (fusion > fission) and Tmem135 TG mice (fusion < fission) using nuclear magnetic resonance (NMR) spectroscopy. Metabolomics analysis revealed a tissue-dependent response to alterations to Tmem135 whereby, significant metabolic changes were observed in heart in both mutant and TG mice as compared to WT while negligible effects were observed in cerebellum and hippocampus. We also observed changes in Tmem135FUN025/FUN025 and Tmem135 TG RPE cells associated with osmosis, glucose metabolism and phospholipid metabolism. Significant depletion of NAD+ was detected in both Tmem135FUN025/FUN025 and Tmem135 TG RPE cells, indicating that imbalance in mitochondrial dynamics to both directions lowers the cellular NAD+ level. Thus, we have identified metabolomic changes associated with imbalanced mitochondrial dynamics in heart tissue and RPE cells which can likely lead to functional abnormalities.

Dataset Information

Targeted metabolomic profiling of retinas from WT and Rho-Cre/Mfn1flx/flx/Mfn2flx/flx mice

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets