Mitochondrial dysfunction in long-term neuronal cultures mimics changes with aging

Abstract

SummaryBackgroundAging is a highly complex process that affects various tissues and systems in the body. Senescent changes are relatively more prevalent and severe in the postmitotic cells. Mitochondria play an important role in the aging process. Recently, cell cultures have been widely used as an in vitro model to study aging. The present study was designed to investigate mitochondrial dysfunction associated with aging in a long-term cell culture system.Material/MethodsRat hippocampal neurons were maintained in culture in serum-free medium for 30 days in vitro (DIV). The morphology and development of hippocampal neurons was observed by phase contrast microscope. The levels of cellular senescence were evaluated by cytochemical staining of senescence-associated β-galactosidase (SA-β-Gal) at DIV 5, 10, 15, 20, 25 and 30. In addition, we investigated the changes in mitochondrial membrane potential (Δψm) and intracellular reactive oxygen species (ROS) generation of hippocampal neurons by flow cytometry at different ages.ResultsThe proportion of the senescent cells steadily increased with age in neuron cultures. Δψm decreased gradually with age in long-term culture, while ROS generation increased.ConclusionsThis study indicates an age-related decrease in mitochondrial function in long-term hippocampal neuronal culture and suggests that DIV 25 neurons could possibly serve as a platform for the future study of anti-aging from the perspective of mitochondrial function.

Neurons from senescence‐accelerated SAMP8 mice are protected against frailty by the sirtuin 1 promoting agents melatonin and resveratrol

“…Diverse neuronal cultures aged in vitro have been used as a model of aging neurons. After a long‐term culture of 30–60 DIV, cerebral cortical or hippocampal neurons from conventional strains of rats or mice show mitochondrial dysfunction [45], decreased Ca 2+ signaling [46], protein oxidation [47], or amyloidogenesis [48]. However, culture conditions exert some stress on the cells, and long‐term cultures may induce some changes different from those in aging in vivo.…”

Innate immunity and cellular senescence: The good and the bad in the developmental and aged brain

“…Although these cells do not undergo replicative senescence, recent studies revealed that neurons can show a stress‐induced senescence‐like phenotype. Increased β‐galactosidase activity and mitochondrial dysfunction were observed in hippocampal neurons in long‐term cultures in vitro, and β‐galactosidase‐positive staining was detected also in vivo in the hippocampus of aging rat . Furthermore, in response to DNA damage, purkinje, hippocampal, and cortical mouse neurons exhibit different markers of senescence, including heterochromatinization, synthesis of proinflammatory interleukins, and high b‐galactosidase activity.…”

In vitro aging promotes endoplasmic reticulum (ER)-mitochondria Ca 2+ cross talk and loss of store-operated Ca 2+ entry (SOCE) in rat hippocampal neurons

“…Whether this transfer is affected by aging has not been addressed. Inasmuch as mitochondrial potential (ΔѰ), the main driving force for mitochondrial Ca 2+ uptake, decreases with age [4,25], it is possible that aging may influence Ca…”