Human testicular peritubular cells secrete pigment epithelium-derived factor (PEDF), which may be responsible for the avascularity of the seminiferous tubules.
Male fertility depends on spermatogenesis, which takes place in the seminiferous tubules of the testis. This compartment is devoid of blood vessels, which are however found in the wall of the seminiferous tubules. Our proteomic study using cultured human testicular peritubular cells (HTPCs) i.e. the cells, which form this wall, revealed that they constitutively secrete pigment epithelium-derived factor, PEDF, which is known to exert anti-angiogenic actions. Immunohistochemistry supports its presence in vivo, in the human tubular wall. Co-culture studies and analysis of cell migration patterns showed that human endothelial cells (HUVECs) are repulsed by HTPCs. The factor involved is likely PEDF, as a PEDF-antiserum blocked the repulsing action. Thus testicular peritubular cells, via PEDF, may prevent vascularization of human seminiferous tubules. Dihydrotestosterone (DHT) increased PEDF (qPCR) in HTPCs, however PEDF expression in the testis of a non-human primate occurs before puberty. Thus PEDF could be involved in the establishment of the avascular nature of seminiferous tubules and after puberty androgens may further reinforce this feature. Testicular microvessels and blood flow are known to contribute to the spermatogonial stem cell niche. Hence HTPCs via control of testicular microvessels may contribute to the regulation of spermatogonial stem cells, as well.
Biomedical Center (BMC), Cell Biology, Anatomy III, LMU, Munich, Germany.
S
S
Windschüttl
Biomedical Center (BMC), Cell Biology, Anatomy III, LMU, Munich, Germany.
C
C
Kampfer
Biomedical Center (BMC), Cell Biology, Anatomy III, LMU, Munich, Germany.
C
C
Mayer
Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU, Munich, Germany.
F
F
Flenkenthaler
Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU, Munich, Germany.
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T
Fröhlich
Andrologie-Centrum-München, Lortzingstraße 26, 81241, Munich, Germany.
J U
JU
Schwarzer
Andrologicum Burgstraße 7, 80331, Münich, Germany.
F M
FM
Köhn
Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, USA.
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H
Urbanski
Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, LMU, Munich, Germany.
G J
GJ
Arnold
Biomedical Center (BMC), Cell Biology, Anatomy III, LMU, Munich, Germany.
A
A
Mayerhofer
D000328:Adult; D002478:Cells, Cultured; D005136:Eye Proteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D018919:Neovascularization, Physiologic / Q000502:physiology*; D009414:Nerve Growth Factors / Q000378:metabolism*; D012671:Seminiferous Tubules / Q000098:blood supply* / Q000378:metabolism*; D015843:Serpins / Q000378:metabolism*; D013737:Testis / Q000098:blood supply* / Q000378:metabolism*; D055815:Young Adult; D000099174:Pigment Epithelium-Derived Factor
D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor