Testicular torsion-detorsion causes dysfunction of mitochondrial oxidative phosphorylation

Abstract

Background: Semen quality impairment is a serious consequence of testicular torsion-detorsion. Adequate germ-cell mitochondrial oxidative phosphorylation plays a crucial role in male fertility. Changes in cellular oxidative phosphorylation in testicular tissues after testicular torsion-detorsion remain unclear.

Objectives: This study investigated whether testicular torsion-detorsion induces alternations of mitochondrial oxidative phosphorylation in testicular tissues.

Materials and methods: BALB/c male mice were divided into a Sham group and a testicular torsion-detorsion group. At the end of the procedure, the mice were euthanized, and their bilateral testicles were removed. Mitochondria morphology was evaluated through transmission electron microscopy. The cellular respiratory functions of germ cells were evaluated using a Seahorse analyzer assay. The proteome profiles in testicular tissues were analyzed using liquid chromatography-tandem mass spectrometry. The differences in the expression levels of each component in the oxidative phosphorylation were revealed using Ingenuity Pathways Analysis.

Results: Inner mitochondrial membrane disruption was found in ipsilateral twisted testicular mitochondria in the torsion-detorsion group but not in contralateral untwisted testes. The cellular respiratory function in germ cells was significantly decreased after testicular torsion-detorsion in ipsilateral twisted testes but not in contralateral untwisted testes. Liquid chromatography-tandem mass spectrometry analysis of ipsilateral twisted testicular tissue revealed that mitochondrial proteins were differentially expressed after testicular torsion-detorsion. Testicular torsion-detorsion induced downregulation of oxidative phosphorylation and revealed alternations of specific proteins in the oxidative phosphorylation complexes.

Discussion and conclusion: Testicular torsion-detorsion produced mitochondria injury and dysregulation of mitochondrial oxidative phosphorylation in ipsilateral twisted testes. Different protein expressions were identified in the mitochondrial oxidative phosphorylation complexes with testicular torsion-detorsion; new therapeutic targets may be identified to restore the oxidative phosphorylation function of germ cells.

Keywords: oxidative; phosphorylation; reperfusion; testis; torsion.