Association between Sperm Morphology and Altered Sperm microRNA Expression

Abstract

Evaluation of male infertility has been based on semen analysis for years. As this method can be subjective at times, there is a scientific tendency to discover stable and quantifiable biomarkers. This study included 28 couples who underwent an in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycle. The couples were assigned into two groups, according to sperm morphology. Couples where the males were normozoospermic were placed in the control group (15 participants), while couples where males had teratozoospermia were placed in the study group (13 participants). Thirteen candidate miRNAs were selected for qPCR analysis, based on our literature search. We determined significant under-expression of nine miRNAs (miR-10a-5p/-15b-5p/-26a-5p/-34b-3p/-122-5p/-125b-5p/-191-5p/-296-5p and let-7a-5p) in spermatozoa from patients with teratozoospermia compared to the controls, whereas expression levels of four miRNAs (miR-92a-3p/-93-3p/-99b-5p/-328-3p) did not significantly differ between the study and control groups. The expression levels of all 13 included miRNAs were significantly positively correlated with each other and significantly positively associated with spermatozoa morphology, excluding miR-99b-5p. There were no other significant associations between miRNA expression and sperm quality parameters. Only expression levels of miR-99b-5p were significantly positively correlated with good-quality day 3 embryo rate (ρ = 0.546; p = 0.003), while other variables of the IVF/ICSI cycle outcome showed no significant associations with miRNA expression profiles. This is one of the rare studies providing an insight directly into miRNA profiles in regard to sperm morphology. We identified nine miRNAs that could serve as biomarkers of spermatozoa quality in regard to teratozoospermia.

Extracellular vesicle-coupled miRNA profiles of chicken seminal plasma and their potential interaction with recipient cells

“…Over-expression of miR-100 promotes the proliferation of spermatogonial stem cells in vitro ( Huang et al, 2017b ). Another study in human detected significant under-expression of miR-10a-5p in spermatozoa from patients with teratozoospermia ( Tomic et al, 2022 ). The miR-10a-5p is proposed to be related to the proliferation and differentiation of porcine spermatogonia ( Chen et al, 2017 ; Keles et al, 2021 ).…”

Identification of key miRNAs as regulatory biomarkers of gonadotropins leading to infertility in males

“…The underexpression of predicted miR-296 has been reported in highly fertile men suggesting that overexpression of miR-296 leads to infertility [49]. Additionally, elevated level of miR-296 expression has been also predicted in patients diagnosed with several classes of male factor infertility particularly teratozoospermia, asthenozoospermia, oligozoospermia and normozoospermia indicating characteristic role of miR-296 in inducing infertility [50]. Among impaired spermatogenesis cases of male Korean population, miR-4739-STAG3 interaction has been observed however STAG3 gene is a known hallmark of male factor infertility therefore predicted miR-4739 can be used as therapeutic target against male infertility [41].…”

MicroRNAs in spermatogenesis dysfunction and male infertility: clinical phenotypes, mechanisms and potential diagnostic biomarkers

“…The expression of nine miRNAs, namely miR-10a-5p, miR-15b-5p, miR-26a-5p, miR-34b-3p, miR-122-5p, miR-125b-5p, miR-191-5p, miR-296-5p, and miR-let-7a-5p, was lower in the spermatozoa of patients with teratozoospermia than in those of control individuals. These miRNAs are positively associated with each other, and their abundance is positively associated with spermatozoa morphology ( 31 ). A previous study reported a significant association between the expression of hsa-mir-191-5p and sperm morphology, but no significant association was observed between sperm density and viability ( 27 ).…”