Chromatin Protamination and Catsper Expression in Spermatozoa Predict Clinical Outcomes after Assisted Reproduction Programs

Abstract

Identification of parameters predicting assisted reproductive technologies (ARTs) success is a major goal of research in reproduction. Quality of gametes is essential to achieve good quality embryos and increase the success of ARTs. We evaluated two sperm parameters, chromatin maturity and expression of the sperm specific calcium channel CATSPER, in relation to ART outcomes in 206 couples undergoing ARTs. Chromatin maturity was evaluated by Chromomycin A3 (CMA3) for protamination and Aniline Blue (AB) for histone persistence and CATSPER expression by a flow cytometric method. CMA3 positivity and CATSPER expression significantly predicted the attainment of good quality embryos with an OR of 6.6 and 14.3 respectively, whereas AB staining was correlated with fertilization rate. In the subgroup of couples with women ≤35 years, CATSPER also predicted achievement of clinical pregnancy (OR = 4.4). Including CMA3, CATSPER and other parameters affecting ART outcomes (female age, female factor and number of MII oocytes), a model that resulted able to predict good embryo quality with high accuracy was developed. CMA3 staining and CATSPER expression may be considered two applicable tools to predict ART success and useful for couple counseling. This is the first study demonstrating a role of CATSPER expression in embryo development after ARTs programs.

LH supplementation of ovarian stimulation protocols influences follicular fluid steroid composition contributing to the improvement of ovarian response in poor responder women

“…Recently, we demonstrated a relationship between some sperm characteristics and embryo quality 47 . Successful implantation, on the other hand, depends on embryo quality 47 – 49 , as well as several other factors related to the receiving woman.…”

Uterine size and volume are associated with a higher clinical pregnancy rate in patients undergoing assisted reproduction technology

“…The outcome of ART is influenced by many determinants, such as sperm quality, oocyte quality, hormone level, and so forth. [9–11] In normal conditions, gynecologists have eliminated the cause of congenital uterine malformation, with little consideration for uterine factors, including uterine length, width, anteroposterior diameter, and total volume, are predictive of clinical pregnancy rate.…”

Sperm chromatin condensation and single‐ and double‐stranded DNA damage as important parameters to define male factor related recurrent miscarriage

“…DNA condensation and defects of sperm protamination can be evaluated through different cytochemical tests such as aniline blue, toluidine blue, or the CMA3 test (De Iuliis et al, 2009; Talebi et al, 2008). CMA3 competes with protamines in DNA binding to the DNA's minor groove and, therefore, it binds to zones with abnormal protamination, generating fluorescence that can be visualized in an epifluorescence microscope (Marchiani et al, 2017; Talebi et al, 2008). In this study, a weak but significant correlation between an alkaline comet, representing oxidative single‐stranded DNA damage, and CMA3 was found.…”

“…CMA3 is an indicator of the extent of chromatin protamination in mature spermatozoa, as it competes with protamines for the binding to the minor groove of the DNA (Marchiani et al, 2017). Then, a sperm cell with poor protamination would leave free protamination sites, which will be occupied by chromomycin and, therefore, fluorescence will be emitted.…”