Vanadium inhalation induces retinal Müller glial cell (MGC) alterations in a murine model

Abstract

Background: Vanadium (V) is a transition metal adhered to suspended particles. Previous studies demonstrated that V inhalation causes oxidative stress in the ependymal epithelium, the choroid plexus on brain lateral ventricles and in the retina. Inhaled-V reaches the eye´s retina through the systemic circulation; however, its effect on the retina has not been widely studied. The Müller glial cell provides support and structure to the retina, facilitates synapses and regulates the microenvironment and neuronal metabolism. Hence, it is of great interest to study the effect of V exposure on the expression and localization of specific biomarkers on this cell.

Methods: Male CD-1 mice were exposed to V inhalation 1 h/twice/week for 4 and 8-Wk. Expression changes in the retina of Glial fibrillary acidic protein, highly expressed in Müller glial cell when retina is damaged, and Glutamine synthetase, important in preventing excitotoxicity in the retina, were analysed by immunohistochemistry.

Results: Glial fibrillary acidic protein expression increased at 4-Wk of V inhalation compared to the control and decreased at 8-Wk of exposure. A time-dependent gradual reduction in glutamine synthetase expression was observed.

Conclusion: Changes in glial fibrillary acidic protein expression induced by V suggest retinal damage, whereas glutamine synthetase gradual reduction might indicate that photoreceptors, which produce most of the glutamine synthetase substrate in the retina, are degenerating, probably as a consequence of the oxidative stress induced by V.

Keywords:

• Retina
• vanadium
• Müller glial cell
• retinal toxicology

Acknowledgements

Authors thank Raquel Guerrero-Alquicira and Veronica Rodriguez-Mata for their technical assistance in the histological processing, and Armando Zepeda Rodriguez and Francisco Pasos-Najera for their assistance in the photographic artwork. Authors also thank Enrique Pinzón Estrada and Ismael Torres Saldaña, members of the school of Medicine vivarium, UNAM.

Disclosure statement

The authors declare that there is no conflict of interest regarding the publication of this paper. The authors alone are responsible for the content of this manuscript.

Additional information

Funding

This study was supported in part by DGAPA-PAPIIT IN211315. Cervantes-Yépez is a recipient of a scholarship from CONACyT-México [CVU: 609435].