title: AZFc deletions do not affect the function of human spermatogonia in vitro.
abstract: Azoospermic factor c (AZFc) deletions are the underlying cause in 10% of azoo- or severe oligozoospermia. Through extensive molecular analysis the precise genetic content of the AZFc region and the origin of its deletion have been determined. However, little is known about the effect of AZFc deletions on the functionality of germ cells at various developmental steps. The presence of normal, fertilization-competent sperm in the ejaculate and/or testis of the majority of men with AZFc deletions suggests that the process of differentiation from spermatogonial stem cells (SSCs) to mature spermatozoa can take place in the absence of the AZFc region. To determine the functionality of AZFc-deleted spermatogonia, we compared in vitro propagated spermatogonia from six men with complete AZFc deletions with spermatogonia from three normozoospermic controls. We found that spermatogonia of AZFc-deleted men behave similar to controls during culture. Short-term (18 days) and long-term (48 days) culture of AZFc-deleted spermatogonia showed the same characteristics as non-deleted spermatogonia. This similarity was revealed by the same number of passages, the same germ cell clusters formation and similar level of genes expression of spermatogonial markers including ubiquitin carboxyl-terminal esterase L1 (UCHL1), zinc finger and BTB domain containing 16 (ZBTB16) and glial cell line-derived neurotrophic factor family receptor alpha 1 (GFRA1), as well as germ cell differentiation markers including signal transducer and activator of transcription 3 (STAT3), spermatogenesis and oogenesis specific basic helix-loophelix 2 (SOHLH2), v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) and synaptonemal complex protein 3 (SYCP3). The only exception was melanoma antigen family A4 (MAGEA4) which showed significantly lower expression in AZFc-deleted samples than controls in short-term culture while in long-term culture it was hardly detected in both AZFc-deleted and control spermatogonia. These data suggest that, at least in vitro, spermatogonia of AZFc-deleted men are functionally similar to spermatogonia from non-deleted men. Potentially, this enables treatment of men with AZFc deletions by propagating their SSCs in vitro and autotransplanting these SSCs back to the testes to increase sperm counts and restore fertility.
authors.affiliation: Center for Reproductive Medicine, Women's and Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam 1105AZ, The Netherlands Present address: Wake Forest Institute for Regenerative Medicine, Wake Forest University school of Medicine, Winston-Salem, 27101 NC, USA.
authors.forename: B
authors.initials: B
authors.lastname: Nickkholgh
authors.affiliation: Center for Reproductive Medicine, Women's and Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam 1105AZ, The Netherlands.
authors.forename: C M
authors.initials: CM
authors.lastname: Korver
authors.affiliation: Center for Reproductive Medicine, Women's and Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam 1105AZ, The Netherlands.
authors.forename: S K M
authors.initials: SK
authors.lastname: van Daalen
authors.affiliation: Center for Reproductive Medicine, Women's and Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam 1105AZ, The Netherlands.
authors.forename: A M M
authors.initials: AM
authors.lastname: van Pelt
authors.affiliation: Center for Reproductive Medicine, Women's and Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam 1105AZ, The Netherlands s.repping@amc.uva.nl.
authors.forename: S
authors.initials: S
authors.lastname: Repping
mesh_terms: D001324:Autoantigens / Q000235:genetics* / Q000378:metabolism; D053713:Azoospermia / Q000235:genetics* / Q000503:physiopathology; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics* / Q000378:metabolism; D000075364:Deleted in Azoospermia 1 Protein; D017353:Gene Deletion; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics; D013093:Spermatogonia / Q000502:physiology*; D013737:Testis / Q000378:metabolism; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D001324:Autoantigens; D011508:Chondroitin Sulfate Proteoglycans; D000075364:Deleted in Azoospermia 1 Protein; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008565:Membrane Proteins; D009687:Nuclear Proteins; D011506:Proteins; D019009:Proto-Oncogene Proteins c-kit; D016601:RNA-Binding Proteins; C466623:BPY2 protein, human; C118459:CDY1 protein, human; C101390:CSPG4 protein, human; D000099216:Chondroitin Sulfate Proteoglycan 4; C095668:DAZ1 protein, human; C097741:Golgin subfamily A member 2
keywords: AZFc; SSC; infertility; spermatogonia