Disruption of the protein C inhibitor gene results in impaired spermatogenesis and male infertility
Pavel Uhrin, … , Bernd R. Binder, Margarethe Geiger
Pavel Uhrin, … , Bernd R. Binder, Margarethe Geiger
Published December 15, 2000
Citation Information: J Clin Invest. 2000;106(12):1531-1539. https://doi.org/10.1172/JCI10768.
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Article

Disruption of the protein C inhibitor gene results in impaired spermatogenesis and male infertility

Abstract

Protein C inhibitor (PCI) is a nonspecific, heparin-binding serpin (serine protease inhibitor) that inactivates many plasmatic and extravascular serine proteases by forming stable 1:1 complexes. Proteases inhibited by PCI include the anticoagulant activated protein C, the plasminogen activator urokinase, and the sperm protease acrosin. In humans PCI circulates as a plasma protein but is also present at high concentrations in organs of the male reproductive tract. The biological role of PCI has not been defined so far. However, the colocalization of high concentrations of PCI together with several of its target proteases in the male reproductive tract suggests a role of PCI in reproduction. We generated mice lacking PCI by homologous recombination. Here we show that PCI–/– mice are apparently healthy but that males of this genotype are infertile. Infertility was apparently caused by abnormal spermatogenesis due to destruction of the Sertoli cell barrier, perhaps due to unopposed proteolytic activity. The resulting sperm are malformed and are morphologically similar to abnormal sperm seen in some cases of human male infertility. This animal model might therefore be useful for analyzing the molecular bases of these human conditions.

Authors

Pavel Uhrin, Mieke Dewerchin, Mario Hilpert, Peter Chrenek, Christian Schöfer, Margareta Zechmeister-Machhart, Gerhard Krönke, Anja Vales, Peter Carmeliet, Bernd R. Binder, Margarethe Geiger

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Disruption of the PCI gene. (a) Genomic organization of the PCI allele i...
Disruption of the PCI gene. (a) Genomic organization of the PCI allele in 129S/v mouse strain. Polymorphic restriction sites, present in the majority (more than 90%) of analyzed Swiss mice, are indicated by asterisks. Black boxes in the genomic structure represent exon sequences. Upon homologous recombination, the neo gene replaces a 3.6-kb genomic fragment consisting of a major part of exon II, exons III and IV, and a major part of exon V, leading to complete disruption of the PCI gene. WT, wild type; HR, homologously recombined. (b) Southern blot analysis of mouse genomic DNA digested with BglII and hybridized to a 5′ flanking probe. The appearance of a novel 8.7-kb band indicates correct targeting at the 5′ end of the gene. (c) DNA digested with HindIII and hybridized to a 3′ semi-internal probe C. The appearance of a novel 10.4-kb band indicates correct targeting at the 3′ end of the gene. In b and c, the presence of two fragments differing in size in wild-type mice reflects polymorphism of the PCI allele occurring in the Swiss mice population. Lane 1, PCI+/+ mice with nonpolymorphic wild-type PCI alleles; lane 2, PCI+/+ homozygous mice with polymorphic wild-type PCI alleles; lane 3, PCI+/+ mice with polymorphic and nonpolymorphic wild-type PCI allele; lane 4, PCI+/– mice with nonpolymorphic wild-type PCI allele; lane 5, PCI+/– mice with polymorphic wild-type PCI allele; lane 6, PCI–/– with targeted PCI alleles. Correct targeting of the clones was further checked with additional digests using internal and neo-specific probes (not shown), confirming correct targeting and excluding additional random integration of the targeting vector at other loci.