Lutein modulates transcription dysregulation of adhesion molecules and spermatogenesis transcription factors induced by testicular ischemia reperfusion injury: it could be SAFE

Abstract

Testicular ischemia reperfusion injury (tIRI) is considered as the underlying mechanism of testicular torsion, which can cause male infertility. tIRI-induced damage was investigated by assessing the gene expression of spermatogenesis master transcription factors (TFs) and that of major adhesion molecules of the blood-testis barrier. The effect of lutein, a hydroxyl carotenoid, in alleviating tIRI-induced damage was also studied. Male Sprague-Dawley rats were divided into three groups: sham, unilateral tIRI, and tIRI + lutein (0.2 mg/kg). tIRI was induced by occlusion of the testicular artery for 1 h, followed by 4 h of reperfusion. Lutein was injected 15 min after the start of ischemia. Histological analysis and real-time polymerase chain reaction revealed significant decreases in tissue biopsy scores, reduced seminiferous tubule diameters, and downregulated the mRNA expression of the TFs cAMP-responsive element modulator (CREM), TATA box-binding protein-related factor 2 (TRF2), and regulatory factor X 2 (RFX2) compared with the sham group. Lutein treatment reversed these effects. The mRNA expression of the adhesion molecules N-cadherin, nectin-2, claudin-11, occludin, and connexin-43 was significantly downregulated during tIRI, but this change was prevented by lutein treatment. In addition, lutein normalized the tIRI-induced increase in total antioxidant capacity, increased malondialdehyde (MDA) levels, augmented number of TdT-mediated dUTP-X nick-end labeling (TUNEL)-positive nuclei, and activated caspase-8 pathway. The components of survivor activating factor enhancement (SAFE) were also activated during tIRI. Increased tissue expression of TNF-α and its receptor, TNFR1, was accompanied by increased phosphorylation of Janus kinase (JAK) and STAT3, which was prevented by lutein treatment. Our findings suggested that tIRI-induced spermatogenic damage may involve modulation of the SAFE pathway and could benefit from lutein treatment.

Keywords: Adhesion molecules; Apoptosis; Lutein; Spermatogenesis; Testicular ischemia reperfusion injury; Transcription factors.