Influence of temperature, serum, and gonadotropin supplementation in short- and long-term organotypic culture of human immature testicular tissue

Abstract

Objective: To study how temperature, serum, and gonadotropin supplementation affect the organotypic culture of human immature testicular tissue (ITT) in vitro.

Design: Experimental basic science study.

Setting: Reproductive biology laboratory.

Patient(s): ITT from 4 boys with cancer that had testicular tissue cryopreserved as part of their fertility preservation treatment.

Intervention(s): In vitro organotypic culture of ITT, exposed to different temperatures (37°C vs. 34°C), serum (fetal bovine serum [FBS] vs. Knockout Serum Replacement [KOS]), and gonadotropin supplementation (with and without FSH and LH).

Main outcome measure(s): Characterization of the tissue was performed at days 0, 14, and 70 with the use of reverse-transcription quantitative polymerase chain reaction, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling, histologic analysis by means of hematoxylin-eosin staining, and immunohistochemical staining. Hormonal secretion was determined at days 3, 14, 28, and 70 by means of immunofluorescent assay.

Result(s): The 37°C conditions showed an accelerated loss of tubular morphology and higher intratubular apoptosis. KOS supplementation triggered the up-regulation of STAR, SOX9, DAZL, DDX4, PLZF, and UTF1, the percentage of SOX9+/androgen receptor (AR)-positive mature Sertoli cells at day 14, and testosterone secretion. Gonadotropin supplementation increased the numbers of both undifferentiated UTF1+ spermatogonia and premeiotic VASA+/SYCP3+ spermatogonia at day 14, and the number of SOX9+ Sertoli cells at day 70. The low SOX9+/AR+ colocalization, the disorganized pattern of ZO-1, and the progressive decrease of antimüllerian hormone secretion indicated inefficient Sertoli cell maturation in vitro.

Conclusion(s): The 34°C condition in KOS showed the best results for the survival of both spermatogonia and Sertoli cells. FSH/LH supplementation also improved long-term survival of Sertoli cells and the maturation of spermatogonia up to meiotic initiation in short-term culture.

Keywords: Fertility preservation; human immature testicular tissue; in vitro spermatogenesis; organotypic culture.