Sheep primary astrocytes under starvation conditions express higher amount of LC3 II autophagy marker than neurons.

Autophagy is a general term for the degradation of cytoplasmic components within lysosomes. Recent studies have clearly demonstrated that autophagy has a greater variety of physiological and pathophysiological roles than expected, such as starvation adaptation, intracellular protein and organelle clearance, development, anti-aging, elimination of microorganisms, cell death, tumor suppression and antigen presentation. MAP-LC3 is one of the most common markers  to evaluate autophagic processes.

Brain aging and testosterone-induced neuroprotection: studies on cultured sheep cortical neurons.

Objective: This research reports the expression of topoisomerase βII in fetal sheep neuronal cells. The β isoform of DNA topoisomerase II plays a role in DNA repair process in non proliferating cells as neurons and its expression tends to be downregulated with senescence.

Methods: Cortical neurons from 60-day-old sheep embryos underwent two protocols: the former based on rising time of culture (10, 20 and 30 days); the latter based on the 72hrs exposure to 3-nitro-L-tyrosine (oxidative/nitrosative stressor) and/or testosterone.

Aromatase expression in cultured fetal sheep astrocytes after nitrosative/oxidative damage.

Aromatase, the enzyme converting androgens into estrogens, is involved in many brain processes such as neural differentiation and plasticity or the prevention of cell death. We have previously observed an increase in aromatase immunoreactivity in sheep neurons exposed in vitro to the oxidant 3-nitro-L: -tyrosine. However, little is known regarding the way that sheep astrocytes cope with nitrosative stress, a condition occurring in sheep in the pathogenesis of neurodegenerative disorders such as scrapie and Maedi-Visna.

Expression and distribution of P450-aromatase in the ovine hypothalamus at different stages of fetal development.

Objectives: An important step of sexual differentiation is the conversion of testosterone to estrogen by aromatase leading to masculinization and defeminization of the fetal brain areas crucial for normal sexual behavior and reproduction. Brain sexual differentiation occurs throughout a critical period starting from different prenatal stages depending on the species. Such period goes on from gestation day (GD) 30 to 100GD in the sheep.