Impaired mitochondrial morphological plasticity and failure of mitophagy associated with the G11778A mutation of LHON.

Mitochondrial dynamics were examined in human dermal fibroblasts biopsied from a confirmed Leber's Hereditary Optic Neuropathy (LHON) patient with a homoplasmic G11778A mutation of the mitochondrial genome. Expression of the G11778A mutation did not impart any discernible difference in mitochondrial network morphology using widefield fluorescence microscopy. However, at the ultrastructural level, cells expressing this mutation exhibited an impairment of mitochondrial morphological plasticity when forced to utilize oxidative phosphorylation (OXPHOS) by transition to glucose-free, galactose-containing media.

Galactose-replacement unmasks the biochemical consequences of the G11778A mitochondrial DNA mutation of LHON in patient-derived fibroblasts.

Leber's hereditary optic neuropathy (LHON) is a visual impairment associated with mutations of mitochondrial genes encoding elements of the electron transport chain. While much is known about the genetics of LHON, the cellular pathophysiology leading to retinal ganglion cell degeneration and subsequent vision loss is poorly understood. The impacts of the G11778A mutation of LHON on bioenergetics, redox balance and cell proliferation were examined in patient-derived fibroblasts.

Endosomal recycling and dopamine neurotransmission: Exploring the links between the retromer and Parkinson's disease.

The retromer complex is an evolutionarily conserved protein complex involved in the endosomal recycling of various cargo proteins. It is ubiquitously expressed in all tissue and is found in both invertebrate as well as mammalian nervous systems, where it recycles various synaptic membrane proteins including the dopamine transporter and dopamine D1 receptor, two proteins implicated in dopamine homeostasis and neurotransmission. The involvement of the retromer complex in dopamine neurobiology is further underscored by its links to Parkinson's disease, a neurodegenerative disorder of the dopamine system.

Kif5 regulates mitochondrial movement, morphology, function and neuronal survival.

Due to the unique architecture of neurons, trafficking of mitochondria throughout processes to regions of high energetic demand is critical to sustain neuronal health. It has been suggested that compromised mitochondrial trafficking may play a role in neurodegenerative diseases. We evaluated the consequences of disrupted kif5c-mediated mitochondrial trafficking on mitochondrial form and function in primary rat cortical neurons.

Changes in mitochondrial morphology induced by calcium or rotenone in primary astrocytes occur predominantly through ros-mediated remodeling.

Morphological changes in mitochondria have been primarily attributed to fission and fusion, while the more pliable transformations of mitochondria (remodeling, rounding, or stretching) have been largely overlooked. In this study, we quantify the contributions of fission and remodeling to changes in mitochondrial morphology induced by the Ca(2+) ionophore 4Br-A23187 and the metabolic toxin rotenone. We also examine the role of reactive oxygen species (ROS) in the regulation of mitochondrial remodeling.