title: Calretinin Immunoreactivity in the Human Testis Throughout Fetal Life.
abstract: The main functions of the testis are sex hormone and sperm cell production. Steroidogenesis occurs in the Leydig interstitial cells and spermatogenesis in the seminiferous tubules. Male gonad morphogenesis is a finely orchestrated process, mainly coordinated by hormones, whose actions can significantly affect post-pubertal testicular function. Calcium is a key intracellular messenger, which regulates many signal transduction pathways, and is also implicated in steroidogenesis. Calcium homeostasis and signaling rely on many calcium-binding proteins including calretinin, of the "EF-hand" protein family. Calretinin is a highly conserved protein mainly expressed in the nervous system but also detected in rat and human adult and fetal testis as well as in pathological conditions. Calretinin expression in the fetal testis, however, has not been thoroughly analyzed probably owing to limited availability and paucity of tissues. Here, we examined by immunocytochemistry the expression of calretinin in human fetal testis specimens, obtained from natural and therapeutic abortions, at various developmental ages. We found that calretinin-immunoreactive Leydig cells were visible throughout the timeframe studied (14th-27th week). Immunoreactivity was also observed in Sertoli cells and in the germ cells of the immature seminiferous tubules. Overall our data indicate that calretinin expression parallels the decline in Leydig cell number, suggesting that its presence is indeed correlated to their steroidogenic activity. They also suggest that the intratubular positivity of calretinin could be linked to the ability of Sertoli cells to produce locally acting hormones contributing to the histodifferentiation of the male genital tract. J. Cell. Physiol. 232: 1872-1878, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Advanced Biomedical Sciences, Medical School, Federico II University of Naples, Naples, Italy.
authors.forename: Giovanna G
authors.initials: GG
authors.lastname: Altobelli
authors.affiliation: Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Department of Biology, Temple University, Philadelphia, Pennsylvania.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pentimalli
authors.affiliation: Department of Advanced Biomedical Sciences, Medical School, Federico II University of Naples, Naples, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: D'Armiento
authors.affiliation: Department of Histopathology, Imperial College London, Hammersmith Hospital, London, United Kingdom.
authors.forename: Susan
authors.initials: S
authors.lastname: Van Noorden
authors.affiliation: Department of Advanced Biomedical Sciences, Medical School, Federico II University of Naples, Naples, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cimini
mesh_terms: D064032:Calbindin 2 / Q000378:metabolism*; D002648:Child; D004822:Epididymis / Q000166:cytology / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D007985:Leydig Cells / Q000166:cytology / Q000378:metabolism; D008297:Male; D011627:Puberty; D013737:Testis / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*
chemical_list: D064032:Calbindin 2; D047628:Estrogen Receptor alpha