Details

Autor(en) / Beteiligte

• Hvozda Arana, Ailen G.
• Lasagni Vitar, Romina M.
• Reides, Claudia G.
• Calabró, Valeria
• Marchini, Timoteo
• Lerner, S. Fabián
• Evelson, Pablo A.
• Ferreira, Sandra M.

Titel

Mitochondrial function is impaired in the primary visual cortex in an experimental glaucoma model

Ist Teil von

• Archives of biochemistry and biophysics, 2021-04, Vol.701, p.108815-108815, Article 108815

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2021

Quelle

MEDLINE

Beschreibungen/Notizen

• Glaucoma is a neurodegenerative disease that affects eye structures and brain areas related to the visual system. Oxidative stress plays a key role in the development and progression of the disease. The aims of the present study were to evaluate the mitochondrial function and its participation in the brain redox metabolism in an experimental glaucoma model. 3-month-old female Wistar rats were subjected to cauterization of two episcleral veins of the left eye to elevate the intraocular pressure. Seven days after surgery, animals were sacrificed, the brain was carefully removed and the primary visual cortex was dissected. Mitochondrial bioenergetics and ROS production, and the antioxidant enzyme defenses from both mitochondrial and cytosolic fractions were evaluated. When compared to control, glaucoma decreased mitochondrial ATP production (23%, p < 0.05), with an increase in superoxide and hydrogen peroxide production (30%, p < 0.01 and 28%, p < 0.05, respectively), whereas no changes were observed in membrane potential and oxygen consumption rate. In addition, the glaucoma group displayed a decrease in complex II activity (34%, p < 0.01). Moreover, NOX4 expression was increased in glaucoma compared to the control group (27%, p < 0.05). Regarding the activity of enzymes associated with the regulation of the redox status, glaucoma showed an increase in mitochondrial SOD activity (34%, p < 0.05), mostly due to an increase in Mn-SOD (50%, p < 0.05). A decrease in mitochondrial GST activity was observed (11%, p < 0.05). GR and TrxR activity were decreased in both mitochondrial (16%, p < 0.05 and 20%, p < 0.05 respectively) and cytosolic (21%, p < 0.01 and 50%, p < 0.01 respectively) fractions in the glaucoma group. Additionally, glaucoma showed an increase in cytoplasmatic GPx (50%, p < 0.01). In this scenario, redox imbalance took place resulting in damage to mitochondrial lipids (39%, p < 0.01) and proteins (70%, p < 0.05). These results suggest that glaucoma leads to mitochondrial function impairment in brain visual targets, that is accompanied by an alteration in both mitochondrial and cytoplasmatic enzymatic defenses. As a consequence of redox imbalance, oxidative damage to macromolecules takes place and can further affect vital cellular functions. Understanding the role of the mitochondria in the development and progression of the disease could bring up new neuroprotective therapies. [Display omitted] •Glaucoma alters mitochondrial ATP production rate in the primary visual cortex.•Mitochondrial superoxide anion and hydrogen peroxide production increases in glaucoma.•Complex II activity is impaired in glaucoma.•Mitochondrial NOX4 is an additional source of ROS in the mitochondria in glaucoma.•Glaucoma modifies mitochondrial and cytosolic enzyme defenses leading to redox imbalance.