scholarly journals ATP activation of peritubular cells drives testicular sperm transport

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
David Fleck ◽  
Lina Kenzler ◽  
Nadine Mundt ◽  
Martin Strauch ◽  
Naofumi Uesaka ◽  
...  
Keyword(s):  
Purinergic Signaling ◽  
Rete Testis ◽  
Seminiferous Tubules ◽  
Testicular Sperm ◽  
Sperm Transport ◽  
Complex Process ◽  
Immotile Spermatozoa ◽  
Peritubular Cells

Spermatogenesis, the complex process of male germ cell proliferation, differentiation, and maturation, is the basis of male fertility. In the seminiferous tubules of the testes, spermatozoa are constantly generated from spermatogonial stem cells through a stereotyped sequence of mitotic and meiotic divisions. The basic physiological principles, however, that control both maturation and luminal transport of the still immotile spermatozoa within the seminiferous tubules remain poorly, if at all, defined. Here, we show that coordinated contractions of smooth muscle-like testicular peritubular cells provide the propulsive force for luminal sperm transport toward the rete testis. Using a mouse model for in vivo imaging, we describe and quantify spontaneous tubular contractions and show a causal relationship between peritubular Ca2+ waves and peristaltic transport. Moreover, we identify P2 receptor-dependent purinergic signaling pathways as physiological triggers of tubular contractions both in vitro and in vivo. When challenged with extracellular ATP, transport of luminal content inside the seminiferous tubules displays stage-dependent directionality. We thus suggest that paracrine purinergic signaling coordinates peristaltic recurrent contractions of the mouse seminiferous tubules to propel immotile spermatozoa to the rete testis.

scholarly journals ATP activation of peritubular cells drives testicular sperm transport

2020 ◽  
Author(s):  
David Fleck ◽  
Lina Kenzler ◽  
Nadine Mundt ◽  
Martin Strauch ◽  
Naofumi Uesaka ◽  
...  
Keyword(s):  
Developmental Process ◽  
Purinergic Signaling ◽  
Rete Testis ◽  
Seminiferous Tubules ◽  
Testicular Sperm ◽  
Sperm Transport ◽  
Immotile Spermatozoa ◽  
Peritubular Cells

AbstractSpermatogenesis, the complex developmental process of male germ cell proliferation, differentiation, and maturation, is the basis of male fertility and reproductive fitness. In the seminiferous tubules of the testes, spermatozoa are constantly generated from spermatogonial stem cells through a stereotyped sequence of mitotic and meiotic divisions. The basic physiological principles, however, that control both maturation and luminal transport of the still immotile spermatozoa within the seminiferous tubules remain poorly, if at all, defined. Here, we show that coordinated contractions of smooth muscle-like testicular peritubular cells provide the propulsive force for luminal sperm transport towards the rete testis and epididymis. Using a mouse model for in vivo imaging, we describe and quantify spontaneous tubular contractions and show a causal relationship between peritubular Ca2+ waves and peristaltic transport. Moreover, we identify P2 receptor-dependent purinergic signaling pathways as physiological triggers of tubular contractions both in vitro and in vivo. When challenged with extracellular ATP, transport of luminal content inside the seminiferous tubules displays stage-dependent directionality. We thus suggest that paracrine purinergic signaling coordinates peristaltic recurrent contractions of the mouse seminiferous tubules to propel immotile spermatozoa to the rete testis. Consequently, our findings could have substantial pharmaceutical implications for both infertility treatment and / or male contraception.

METABOLISM OF RAM TESTICULAR SPERMATOZOA IN THE PRESENCE OF TESTOSTERONE AND RELATED STEROIDS

1970 ◽  
Vol 65 (3) ◽  
pp. 565-576 ◽  
Author(s):  
J. K. Voglmayr ◽  
R. N. Murdoch ◽  
I. G. White
Keyword(s):  
Aerobic Glycolysis ◽  
Rete Testis ◽  
Glycolytic Metabolism ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Testicular Spermatozoa ◽  
Almost All ◽  
Oxidation Of Glucose

ABSTRACT The effects of testosterone* and related steroids on the oxidative and glycolytic metabolism of freshly collected ram testicular spermatozoa and of spermatozoa stored under air in rete testis fluid for 3 days at 3°C have been studied. When freshly collected testicular spermatozoa were incubated with glucose under aerobic conditions only a small proportion of the utilized glucose could be accounted for as lactate. The addition of a number of steroids, including testosterone, androstanedione, 5β-androstanedione, androsterone, epiandrosterone and 5β-androsterone, greatly increased aerobic glycolysis, the oxidation of the substrate and the proportion of the utilized substrate converted to lactic acid. After 3 days storage at 3°C, testicular spermatozoa respired at a greater rate than spermatozoa freshly collected from the testes. Although the stimulating effect of steroids on aerobic glycolysis increased after storage, they depressed rather than stimulated the oxidation of glucose by stored testicular spermatozoa. With the exception of androstanedione, which slightly stimulated glycolysis, storage of testicular spermatozoa for 3 days in the presence of steroids did not significantly influence their subsequent metabolism when washed free of the steroids. Both freshly collected and stored ram testicular spermatozoa displayed a marked Pasteur effect, and utilized more glucose and produced more lactate under anaerobic than under aerobic conditions. In the absence of oxygen the steroids did not stimulate glycolysis to any extent. However, epiandrosterone depressed the glycolysis of freshly collected spermatozoa under anaerobic conditions and after storage, 5β-androsterone had a similar effect. Androstanedione, 5β-androstanedione, epiandrosterone and 5β-androsterone were the most effective steroids in altering the metabolism of testicular spermatozoa and, under almost all conditions of incubation, depressed the synthesis of amino acids from glucose. The results suggest that the effects of testosterone and related steroids in vitro may depend on the age of the spermatozoa after their release from the Sertoli cells; the steroid effects may have important consequences in vivo in relation to sperm maturation.

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

1998 ◽  
Vol 9 (2) ◽  
pp. 421-435 ◽  
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.

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

Reproduction ◽  
2020 ◽  
Vol 160 (2) ◽  
pp. 259-268 ◽  
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.

P–056 To graft or not to graft? Intratesticular grafting of testicular tissue from Klinefelter boys to the mouse testis as possible novel in vivo model

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M Willems ◽  
P Sesenhausen ◽  
I Gies ◽  
V Vloeberghs ◽  
J D Schepper ◽  
...  
Keyword(s):  
Klinefelter Syndrome ◽  
Testicular Biopsy ◽  
Testicular Tissue ◽  
Mouse Testis ◽  
In Vivo Model ◽  
Seminiferous Tubules ◽  
Positive Effects ◽  
Fibrotic Process

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

271 THE EFFECT OF TEMPERATURE ON HUMAN TESTICULAR TISSUE TO OPTIMIZE THE IN VITRO MATURATION OF PRE-FREEZE MOTILITY

2009 ◽  
Vol 21 (1) ◽  
pp. 233
Author(s):  
M. C. Schiewe ◽  
A. Spitz ◽  
R. E. Anderson
Keyword(s):  
Sperm Motility ◽  
Seminiferous Tubules ◽  
Type I ◽  
Obstructive Azoospermia ◽  
Percentage Increase ◽  
Testicular Sperm ◽  
Incubation Condition ◽  
Progressive Motility ◽  
Over Time

The development of intracytoplasmic sperm injection has made the use of testicular sperm a viable option for infertile men with obstructive and nonobstructive azoospermia. Over the past decade, testicular biopsies have been handled and processed using a variety of different methods. Whole biopsy pieces can be effectively cryopreserved in a 10% glycerol diluent (Schiewe et al. 1997 67, S115 abst); however, the ability to find viable, motile sperm post-thaw is improved when prefreeze motility exists. The purpose of this study was to comparatively document in vitro sperm motility enhancement over time at different temperatures, and to prove that an intermediate temperature (28 to 30°C) would optimize sperm longevity for up to 1 week. In this study, 10 men with obstructive azoospermia underwent a surgical, open testicular biopsy procedure. Each biopsy was placed in HEPES buffered-human tubal fluid (mHTF) medium supplemented with 5% human serum albumin (HSA; Irvine Sci., Santa Ana, CA, USA) and transported to the laboratory at room temperature. Each testis biopsy (TBx) was dissected into 8 equal pieces (approximately 2 × 2 × 1 mm). Five intact pieces of TBx were cryopreserved in separate cryovials for future use. The remaining TBx tissue was subdivided into 1 of 3 temperature treatment groups (24, 30, or 37°C) for extended IVM. The 30°C incubation condition was achieved by placing the dish(es) in a Styrofoam box placed on a 37°C warming plate. Each TBx was placed into a separate 100 × 35 mm Falcon dish in 150-μL droplets of mHTF under oil and shredded by needle dissection to disperse the contents of the seminiferous tubules. Reminant tissue was placed into another droplet for additional dissection, as needed. Sperm were analyzed for motility (graded as Type I = twitching, II = undulating, III = slow progression, and IV = rapid progression) at 0, 24, 96, and 144 h without replacing the IVM medium. The percentage increase in motility, compared with 0 h, was statistically contrasted across temperature treatments by chi-squared analysis. Testicular sperm motility ranged from 5 to 25% at 0 h and increased in all groups at 24 h. There was no difference in total motility at 24 h, but progressive motility was higher (P < 0.05) at 37°C compared with 24°C. Significant differences (P < 0.05) were observed in total percentage of motility/percentage of progressive motility at 96 h with treatment differences (*) being 30°C (66%*/44%*) > 24°C (42%*/14%) > 37°C (18%*/10%). This statistical trend continued at 144 h with 30°C (42%*/23%*) > 24°C (24%*/8%) > 37°C (9%*/5%). During this study, a viable pregnancy was achieved using a 30°C sample 8 days post biopsy, exceeding 2 previous healthy triplet pregnancies, which were successful using 4-day-old TBx specimens in 1996 and 2004. This study confirms that an intermediate IVM temperature of 30°C is optimal to enhance TBx cryopreservation, which in our laboratory is generally performed at 24 to 72 h of IVM. Our routine pregnancy success in applying ICSI with IVM, thawed TBx sperm discounts the concern some individuals express regarding DNA fragmentation of sperm over time.

scholarly journals Interleukin-34, a Novel Paracrine/Autocrine Factor in Mouse Testis, and Its Possible Role in the Development of Spermatogonial Cells In Vitro

2020 ◽  
Vol 21 (21) ◽  
pp. 8143
Author(s):  
Alaa Sawaied ◽  
Eitan Lunenfeld ◽  
Mahmoud Huleihel
Keyword(s):  
Seminiferous Tubules ◽  
Isolated Cells ◽  
Proliferation And Differentiation ◽  
Endocrine Factors ◽  
First Time ◽  
Old Mice ◽  
Stimulating Factor ◽  
Autocrine Factor ◽  
Peritubular Cells

Spermatogenesis is the process of spermatogonial stem cell (SSC) proliferation and differentiation to generate sperm. This process is regulated by cell–cell interactions between Sertoli cells and developing SSCs by autocrine/paracrine and endocrine factors. It is also affected by cells in the interstitial compartment, such as Leydig cells and peritubular cells. Here, we demonstrate, for the first time, the presence of interleukin-34 (IL-34) in Leydig, Sertoli, and peritubular cells and in the premeiotic, meiotic, and postmeiotic cells. Its receptor, colony-stimulating factor-1 (CSF-1), has already been demonstrated in Leydig, Sertoli, premeiotic, and meiotic cells. IL-34 was detected in testicular homogenates and Sertoli cell-conditioned media, and was affected by mouse age. We showed that the addition of IL-34 in vitro to isolated cells from the seminiferous tubules of 7-day-old mice, using the methylcellulose culture system (MCS), increased the percentages and expression of the premeiotic cells (VASA), the meiotic cells (BOULE), and the meiotic/postmeiotic cells (ACROSIN) after four weeks of culture, when examined by immunofluorescence staining (IF) and qPCR analysis. It is possible to suggest that IL-34 is a novel paracrine/autocrine factor involved in the development of spermatogenesis. This factor may be used in future therapeutic strategies for the treatment of male infertility.

scholarly journals The Glucocorticoid-Induced Leucine Zipper (Gilz/Tsc22d3-2) Gene Locus Plays a Crucial Role in Male Fertility

2012 ◽  
Vol 26 (6) ◽  
pp. 1000-1013 ◽  
Author(s):  
Philippe Emmanuel Suarez ◽  
Elena Gonzalez Rodriguez ◽  
Rama Soundararajan ◽  
Anne-Marie Mérillat ◽  
Jean-Christophe Stehle ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Leucine Zipper ◽  
Inflammatory Responses ◽  
Metabolic Phenotype ◽  
Seminiferous Tubules ◽  
Water Handling ◽  
Renal Sodium Handling ◽  
Leucine Zipper Protein

Abstract The glucocorticoid-induced leucine zipper (Tsc22d3-2) is a widely expressed dexamethasone-induced transcript that has been proposed to be important in immunity, adipogenesis, and renal sodium handling based on in vitro studies. To address its function in vivo, we have used Cre/loxP technology to generate mice deficient for Tsc22d3-2. Male knockout mice were viable but surprisingly did not show any major deficiencies in immunological processes or inflammatory responses. Tsc22d3-2 knockout mice adapted to a sodium-deprived diet and to water deprivation conditions but developed a subtle deficiency in renal sodium and water handling. Moreover, the affected animals developed a mild metabolic phenotype evident by a reduction in weight from 6 months of age, mild hyperinsulinemia, and resistance to a high-fat diet. Tsc22d3-2-deficient males were infertile and exhibited severe testis dysplasia from postnatal d 10 onward with increases in apoptotic cells within seminiferous tubules, an increased number of Leydig cells, and significantly elevated FSH and testosterone levels. Thus, our analysis of the Tsc22d3-2-deficient mice demonstrated a previously uncharacterized function of glucocorticoid-induced leucine zipper protein in testis development.

scholarly journals Inhibition of UDP/P2Y 6 purinergic signaling prevents phagocytosis of viable neurons by activated microglia in vitro and in vivo

Glia ◽  
2014 ◽  
Vol 62 (9) ◽  
pp. 1463-1475 ◽  
Author(s):  
Jonas J. Neher ◽  
Urte Neniskyte ◽  
Tamara Hornik ◽  
Guy C. Brown
Keyword(s):  
Purinergic Signaling ◽  
Activated Microglia

scholarly journals Effect of Dimerizing Domains and Basic Residues on In Vitro and In Vivo Assembly of Mason-Pfizer Monkey Virus and Human Immunodeficiency Virus

2009 ◽  
Vol 84 (4) ◽  
pp. 1977-1988 ◽  
Author(s):  
Karolína Bohmová ◽  
Romana Hadravová ◽  
Jitka Štokrová ◽  
Roman Tůma ◽  
Tomáš Ruml ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Gag Polyprotein ◽  
Complex Process ◽  
Immunodeficiency Virus ◽  
Interaction Domains ◽  
Immature Virus ◽  
Hiv 1 ◽  
Positively Charged

ABSTRACT Assembly of immature retroviral particles is a complex process involving interactions of several specific domains of the Gag polyprotein localized mainly within capsid protein (CA), spacer peptide (SP), and nucleocapsid protein (NC). In the present work we focus on the contribution of NC to the oligomerization of CA leading to assembly of Mason-Pfizer monkey virus (M-PMV) and HIV-1. Analyzing in vitro assembly of substitution and deletion mutants of ΔProCANC, we identified a “spacer-like” sequence (NC15) at the M-PMV NC N terminus. This NC15 domain is indispensable for the assembly and cannot be replaced with oligomerization domains of GCN4 or CREB proteins. Although the M-PMV NC15 occupies a position analogous to that of the HIV-1 spacer peptide, it could not be replaced by the latter one. To induce the assembly, both M-PMV NC15 and HIV-1 SP1 must be followed by a short peptide that is rich in basic residues. This region either can be specific, i.e., derived from the downstream NC sequence, or can be a nonspecific positively charged peptide. However, it cannot be replaced by heterologous interaction domains either from GCN4 or from CREB. In summary, we report here a novel M-PMV spacer-like domain that is functionally similar to other retroviral spacer peptides and contributes to the assembly of immature-virus-like particles.

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