An in Vitro Tubule Assay Identifies HGF as a Morphogen for the Formation of Seminiferous Tubules in the Postnatal Mouse Testis

Abstract Study question Can intratesticular transplanted testis tissue from Klinefelter boys to the mouse testis be used to study the mechanisms behind testicular fibrosis? Summary answer Grafting of testicular tissue from Klinefelter boys to the mouse testis is not a valuable new in vivo model to study Klinefelter-related testicular fibrosis. What is known already Klinefelter syndrome (KS; 47, XXY) affects 1–2 in 1000 males. Most KS men suffer from azoospermia due to a loss of spermatogonial stem cells. Additionally, testicular fibrosis is detected from puberty onwards. However, mechanisms responsible for fibrosis and germ cell loss remain unknown. An optimal in vivo model to study the KS testicular fibrotic process is not available. This study aimed to evaluate a possible in vivo model to study KS-related testicular fibrosis. In addition, the effect of the mast cell blocker ketotifen, which showed positive effects on fertility in infertile non-KS patients, was evaluated in this graft model. Study design, size, duration First, the survival time of the KS graft was established, since it was the first time KS tissue was transplanted to the mouse testis. Testes were collected after two, four, six and eight weeks after which histological and immunohistochemical evaluations were performed. Next, the effect of daily ketotifen injections on the fibrotic appearance of intratesticular grafted testicular tissue from KS and controls was evaluated. Participants/materials, setting, methods Testicular biopsy samples from pre- and peripubertal KS (n = 22) and age-matched control samples (n = 22) were transplanted to the testes of six weeks old Swiss Nu/Nu mice (n = 22). Prior to grafting, testicular tissue pieces were cultured in vascular endothelial growth factor (VEGF) for five days. Next, tissues were transplanted to the mouse testes. Testicular transplants were analysed by immunohistochemistry. In the second experiment, mice were given daily subcutaneous injections of ketotifen or saline. Main results and the role of chance Four weeks after transplantation, all KS grafts could still be retrieved. At a later timepoint, degeneration of the tissue could be detected. In the grafts, recovered four weeks after transplantation, about 30% of the tubules in peripubertal grafts showed a good integrity, while in the prepubertal tissue, 83% of the tubules were intact. A fibrotic score was assigned to each graft. No significant changes in fibrotic score was observed between testicular biopsies before or after transplantation. However, an increased (p < 0.01) fibrotic score was observed after in-vitro treatment with VEGF both in control and KS tissue. Based on recovery and tubule integrity grafts were recovered after four weeks in the second experiment. Treatment with ketotifen did not result in significant histological differences compared to non-treated grafts (KS and control tissue). The survival potential of grafts from KS testicular biopsies of pre- and peripubertal boys was patient- and age-dependent. After four weeks, most KS tissue starts to degenerate. In prepubertal tissue, seminiferous tubules were mostly intact, while tissue from adolescent boys was impaired. Interestingly, no loss of germ cells was observed after transplantation of the testicular tissue. Limitations, reasons for caution The availability of tissue from young KS patients is very scarce, leading to a low number of included patients (n = 8). Testicular tissue pieces from the same patient were included to evaluate the differences before and after transplantation. However, histological variability between testicular tissue biopsy pieces is well-known in KS patients. Wider implications of the findings Since testicular tissue from KS boys, transplanted to the mouse testes, already starts to degenerate after four weeks and the integrity is not optimal, we conclude that this is not a valuable model for future studies. In vitro models to study the KS-testicular fibrosis should be investigated. Trial registration number NA

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Immature rat seminiferous tubules reconstructed in vitro express markers of Sertoli cell maturation after xenografting into nude mouse hosts

MHR Basic science of reproductive medicine ◽

10.1093/molehr/gap081 ◽

2009 ◽

Vol 16 (2) ◽

pp. 97-110 ◽

Cited By ~ 19

Author(s):

K. Gassei ◽

J. Ehmcke ◽

M.A. Wood ◽

W.H. Walker ◽

S. Schlatt

Keyword(s):

Sertoli Cell ◽

Nude Mouse ◽

Cell Maturation ◽

Seminiferous Tubules ◽

Immature Rat

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The Expression Levels and Cellular Localization of Pigment Epithelium Derived Factor (PEDF) in Mouse Testis: Its Possible Involvement in the Differentiation of Spermatogonial Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22031147 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1147

Author(s):

Noy Bagdadi ◽

Alaa Sawaied ◽

Ali AbuMadighem ◽

Eitan Lunenfeld ◽

Mahmoud Huleihel

Keyword(s):

Cellular Localization ◽

Pigment Epithelium ◽

Testicular Tissue ◽

Seminiferous Tubules ◽

Target Cells ◽

Isolated Cells ◽

Expression Levels ◽

Cellular Origin ◽

Pigment Epithelium Derived Factor

Pigment epithelium derived factor (PEDF) is a multifunctional secretory soluble glycoprotein that belongs to the serine protease inhibitor (serpin) family. It was reported to have neurotrophic, anti-angiogenic and anti-tumorigenic activity. Recently, PEDF was found in testicular peritubular cells and it was assumed to be involved in the avascular nature of seminiferous tubules. The aim of this study was to determine the cellular origin, expression levels and target cells of PEDF in testicular tissue of immature and adult mice under physiological conditions, and to explore its possible role in the process of spermatogenesis in vitro. Using immunofluorescence staining, we showed that PEDF was localized in spermatogenic cells at different stages of development as well as in the somatic cells of the testis. Its protein levels in testicular homogenates and Sertoli cells supernatant showed a significant decrease with age. PEDF receptor (PEDF-R) was localized within the seminiferous tubule cells and in the interstitial cells compartment. Its RNA expression levels showed an increase with age until 8 weeks followed by a decrease. RNA levels of PEDF-R showed the opposite trend of the protein. Addition of PEDF to cultures of isolated cells from the seminiferous tubules did not changed their proliferation rate, however, a significant increase was observed in number of meiotic/post meiotic cells at 1000 ng/mL of PEDF; indicating an in vitro differentiation effect. This study may suggest a role for PEDF in the process of spermatogenesis.

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“In Vitro” Assay of Rat Spermatogonial Chalone in Prepuberal Seminiferous Tubules

Andrologia ◽

10.1111/j.1439-0272.1982.tb03093.x ◽

2009 ◽

Vol 14 (1) ◽

pp. 35-42 ◽

Cited By ~ 5

Author(s):

A. THUMANN ◽

E. BUSTOS-OBREGÓN

Keyword(s):

In Vitro Assay ◽

Seminiferous Tubules ◽

Vitro Assay

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Expression and localization of the mRNA for DNA (cytosine-5)- methyltransferase in mouse seminiferous tubules.

Journal of Histochemistry & Cytochemistry ◽

10.1177/42.9.8064134 ◽

1994 ◽

Vol 42 (9) ◽

pp. 1271-1276 ◽

Cited By ~ 14

Author(s):

M Numata ◽

T Ono ◽

S Iseki

Keyword(s):

In Situ Hybridization ◽

Significant Role ◽

Meiotic Prophase ◽

Oligonucleotide Probe ◽

Mouse Testis ◽

Seminiferous Tubules ◽

Hybridization Histochemistry ◽

In Situ Hybridization Histochemistry

DNA (cytosine-5)-methyltransferase (DNA MTase) is the only enzyme known to be involved in the methylation of mammalian DNA. Although the expression of DNA MTase gene is abundant in the testis, little is known about the role of this enzyme during spermatogenesis. We examined the distribution of DNA MTase mRNA in mouse testis by in situ hybridization histochemistry with an oligonucleotide probe. The mRNA signal was observed in the seminiferous tubules and was localized predominantly in spermatogonia and spermatocytes, particularly during the earlier steps of meiotic prophase I, with maximal intensity in the early pachytene cells. These results suggest some significant role for DNA MTase in spermatogenesis.

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Propagation of bovine spermatogonial stem cells in vitro

Reproduction ◽

10.1530/rep-07-0419 ◽

2008 ◽

Vol 136 (5) ◽

pp. 543-557 ◽

Cited By ~ 90

Author(s):

Pedro M Aponte ◽

Takeshi Soda ◽

Katja J Teerds ◽

S Canan Mizrak ◽

Henk J G van de Kant ◽

...

Keyword(s):

Stem Cells ◽

Growth Factor ◽

Cultured Cells ◽

Somatic Cells ◽

Type A ◽

Spermatogonial Stem Cells ◽

Seminiferous Tubules ◽

Type A Spermatogonia ◽

Stimulation Of

The access to sufficient numbers of spermatogonial stem cells (SSCs) is a prerequisite for the study of their regulation and further biomanipulation. A specialized medium and several growth factors were tested to study thein vitrobehavior of bovine type A spermatogonia, a cell population that includes the SSCs and can be specifically stained for the lectin Dolichos biflorus agglutinin. During short-term culture (2 weeks), colonies appeared, the morphology of which varied with the specific growth factor(s) added. Whenever the stem cell medium was used, round structures reminiscent of sectioned seminiferous tubules appeared in the core of the colonies. Remarkably, these round structures always contained type A spermatogonia. When leukemia inhibitory factor (LIF), epidermal growth factor (EGF), or fibroblast growth factor 2 (FGF2) were added, specific effects on the numbers and arrangement of somatic cells were observed. However, the number of type A spermatogonia was significantly higher in cultures to which glial cell line-derived neurotrophic factor (GDNF) was added and highest when GDNF, LIF, EGF, and FGF2 were all present. The latter suggests that a proper stimulation of the somatic cells is necessary for optimal stimulation of the germ cells in culture. Somatic cells present in the colonies included Sertoli cells, peritubular myoid cells, and a few Leydig cells. A transplantation experiment, using nude mice, showed the presence of SSCs among the cultured cells and in addition strongly suggested a more than 10 000-fold increase in the number of SSCs after 30 days of culture. These results demonstrate that bovine SSC self-renew in our specialized bovine culture system and that this system can be used for the propagation of these cells.

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Overexpression of the Matrix Metalloproteinase Matrilysin Results in Premature Mammary Gland Differentiation and Male Infertility

Molecular Biology of the Cell ◽

10.1091/mbc.9.2.421 ◽

1998 ◽

Vol 9 (2) ◽

pp. 421-435 ◽

Cited By ~ 36

Author(s):

Laura A. Rudolph-Owen ◽

Paul Cannon ◽

Lynn M. Matrisian

Keyword(s):

Matrix Metalloproteinase ◽

Transgenic Animals ◽

Reproductive Organs ◽

Mammary Development ◽

Seminiferous Tubules ◽

Interstitial Tissue ◽

Wild Type ◽

The Matrix

To examine the role of matrilysin (MAT), an epithelial cell-specific matrix metalloproteinase, in the normal development and function of reproductive tissues, we generated transgenic animals that overexpress MAT in several reproductive organs. Three distinct forms of human MAT (wild-type, active, and inactive) were placed under the control of the murine mammary tumor virus promoter/enhancer. Although wild-type, active, and inactive forms of the human MAT protein could be produced in an in vitro culture system, mutations of the MAT cDNA significantly decreased the efficiency with which the MAT protein was produced in vivo. Therefore, animals carrying the wild-type MAT transgene that expressed high levels of human MAT in vivo were further examined. Mammary glands from female transgenic animals were morphologically normal throughout mammary development, but displayed an increased ability to produce β-casein protein in virgin animals. In addition, beginning at approximately 8 mo of age, the testes of male transgenic animals became disorganized with apparent disintegration of interstitial tissue that normally surrounds the seminiferous tubules. The disruption of testis morphology was concurrent with the onset of infertility. These results suggest that overexpression of the matrix-degrading enzyme MAT alters the integrity of the extracellular matrix and thereby induces cellular differentiation and cellular destruction in a tissue-specific manner.

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A translational cellular model for the study of peritubular cells of the testis

Reproduction ◽

10.1530/rep-20-0100 ◽

2020 ◽

Vol 160 (2) ◽

pp. 259-268 ◽

Cited By ~ 2

Author(s):

Nina Schmid ◽

Annika Missel ◽

Stoyan Petkov ◽

Jan B Stöckl ◽

Florian Flenkenthaler ◽

...

Keyword(s):

Smooth Muscle ◽

Replicative Senescence ◽

Smooth Muscle Actin ◽

Proteome Analysis ◽

Inflammatory Factors ◽

Seminiferous Tubules ◽

Cellular Model ◽

Mechanistic Studies ◽

Peritubular Cells

Testicular peritubular cells (TPCs) are smooth muscle-like cells, which form a compartment surrounding the seminiferous tubules. Previous studies employing isolated human testicular peritubular cells (HTPCs) indicated that their roles in the testis go beyond sperm transport and include paracrine and immunological contributions. Peritubular cells from a non-human primate (MKTPCs), the common marmoset monkey, Callithrix jacchus, share a high degree of homology with HTPCs. However, like their human counterparts these cells age in vitro and replicative senescence limits in-depth functional or mechanistic studies. Therefore, a stable cellular model was established. MKTPCs of a young adult animal were immortalized by piggyBac transposition of human telomerase (hTERT), that is, without the expression of viral oncogenes. Immortalized MKTPCs (iMKTPCs) grew without discernable changes for more than 50 passages. An initial characterization revealed typical genes expressed by peritubular cells (androgen receptor (AR), smooth-muscle actin (ACTA2), calponin (CNN1)). A proteome analysis of the primary MKTPCs and the derived immortalized cell line confirmed that the cells almost completely retained their phenotype. To test whether they respond in a similar way as HTPCs, iMKTPCs were challenged with forskolin (FSK) and ATP. As HTPCs, they showed increased expression level of the StAR protein (StAR) after FSK stimulation, indicating steroidogenic capacity. ATP increased the expression of pro-inflammatory factors (e.g. IL1B; CCL7), as it is the case in HTPCs. Finally, we confirmed that iMKTPCs can efficiently be transfected. Therefore, they represent a highly relevant translational model, which allows mechanistic studies for further exploration of the roles of testicular peritubular cells.

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