Testicular expression of TDRD1, TDRD5, TDRD9 and TDRD12 in azoospermia

Emad Babakhanzadeh,Mohammad Yahya Vahidi Mehrjardi,Iraj Alipourfard,Ali Khodadadian,Yalda Jamshidi,Majid Nazari,Saadi Rostami,Mehdi Hosseinnia,Mohsen Aghaei,Nasrin Ghasemi

doi:10.1186/s12881-020-0970-0

Abstract

BackgroundTudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males.MethodsHere we evaluate gene and protein expression levels of four key TDRDs (TDRD1, TDRD5, TDRD9 and TDRD12) in testicular biopsy samples obtained from men with obstructive azoospermia (OA, n = 29), as controls, and various types of non-obstructive azoospermia containing hypospermatogenesis (HP, 28), maturation arrest (MA, n = 30), and Sertoli cell-only syndrome (SCOS, n = 32) as cases. One-way ANOVA test followed by Dunnett’s multiple comparison post-test was used to determine inter-group differences in TDRD gene expression among cases and controls.ResultsThe results showed very low expression of TDRD genes in SCOS specimens. Also, the expression of TDRD1 and TDRD9 genes were lower in MA samples compared to OA samples. The expression of TDRD5 significantly reduced in SCOS, MA and HP specimens than the OA specimens. Indeed, TDRD12 exhibited a very low expression in HP specimens in comparison to OA specimens. All these results were confirmed by Western blot technique.ConclusionTDRDs could be very important in male infertility, which should be express in certain stages of spermatogenesis.

Highlights

Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males
The expression of TDRD1, TDRD5, TDRD9 and TDRD12 genes were significantly lower in Sertoli cell-only syndrome (SCOS) than controls (P < 0.001, Dunn’s post-test)
The lack of expression of TDRD genes found in SCOS was a common observation in this study, suggesting that the transcription of these genes could be limited to germ cells

Summary

Introduction

Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. piRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males. Tudor domain-containing proteins (TDRDs) play a critical role in piRNA biogenesis and germ cell development. PiRNAs, small regulatory RNAs, act by silencing of transposons during germline development and it has recently been shown in animal model studies that defects in TDRD genes can lead to sterility in males. Infertility remains a significant global burden [1]. Estimates suggest that 10–15% of couples worldwide experience infertility [2], with male infertility being the underlying cause in 20–50% of cases [3]. For the majority of cases the etiology remains unknown, and is termed idiopathic infertility [4]. PIWI-interacting RNA (piRNA) proteins have recently been shown to play an essential role in male fertility and spermatogenesis in humans [9]. The piRNA pathwayassociated genes are highly expressed in germline cells [10]. piRNAs act by suppressing transposons and preventing their mobilization through both post-transcriptional and transcriptional mechanisms, such as degradation, chromatin remodeling, and DNA methylation [11,12,13,14]

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Discussion

Conclusion