scholarly journals Mice with a Sertoli cell-specific knockout of the Ctr1 gene exhibit a reduced sensitivity to cisplatin-induced testicular germ cell apoptosis

2019 ◽  
Vol 8 (6) ◽  
pp. 972-978 ◽  
Author(s):  
Rashin Ghaffari ◽  
John H. Richburg
Keyword(s):  
Germ Cells ◽  
Fold Increase ◽  
Testicular Germ Cell ◽  
Copper Transporter ◽  
Relative Contribution ◽  
Adult Mice ◽  
Sequence Of Events ◽  
Male Patients ◽  
Testicular Injury

Abstract Exposure to the chemotherapeutic agent cis-diamminedichloroplatinum(ii) (cDDP) is well known to instigate acute and prolonged testicular injury in male patients. Many investigators have hypothesized that cDDP-induced dysfunction of Sertoli cells (SCs) may, in part, account for the cDDP-induced lasting testicular injury. Nevertheless, the relative contribution of cDDP-induced SC injury versus direct effects on germ cells (GCs) to the pathogenesis of GC loss remains to be elucidated. The expression of the copper transporter 1 (CTR1) protein in cells directly corresponds with cDDP uptake and its cellular toxicity. Therefore, to discern the role of SCs in the pathogenic mechanism, mice were developed with a SC-specific disruption of the Ctr1 gene (SCΔCtr1) as a strategy to prevent their exposure to cDDP. Adult mice at postnatal day (PND) 60 were treated with 5 mg kg−1 cDDP and then testis collected at 48 hours. A two-fold increase in GC-apoptosis occurred in the testis of cDDP-treated wildtype (WT) mice as compared to saline-treated WT mice. In contrast, cDDP-treated SCΔCtr1 mice exhibited only a half-fold increase in GC-apoptosis as compared to the saline-treated SCΔCtr1 mice. This reduced incidence of GC apoptosis in the SCΔCtr1 mice corresponded to a significantly lower level of platinum within the testis. Taken together, these findings reveal that the uptake of cDDP by CTR1 in SCs accounts for the accumulation of cDDP in the testis and plays a pivotal role in the pathogenic sequence of events leading to the loss of germ cells via apoptosis.

Gonadal expression of c-kit encoded at the W locus of the mouse

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1057-1069 ◽  
Author(s):  
K. Manova ◽  
K. Nocka ◽  
P. Besmer ◽  
R.F. Bachvarova
Keyword(s):  
In Situ Hybridization ◽  
Germ Cells ◽  
Leydig Cells ◽  
Interstitial Tissue ◽  
Type B ◽  
Age Dependence ◽  
Oocyte Growth ◽  
Adult Mice

Recently, it has been shown that the c-kit proto-oncogene is encoded at the white spotting (W) locus in mice. Mutations of this gene cause depletion of germ cells, some hematopoietic cells and melanocytes. In order to define further the role of c-kit in gametogenesis, we have examined its expression in late fetal and postnatal ovaries and in postnatal testis. By RNA blot analysis, c-kit transcripts were not detected in late fetal ovaries but appeared at birth. The relative amount reached a maximum in ovaries of juvenile mice, and decreased in adult ovaries. c-kit transcripts were present in increasing amounts in isolated primordial, growing and full-grown oocytes, as well as in ovulated eggs. Little was detected in early 2-cell embryos and none in blastocysts. In situ hybridization revealed c-kit transcripts in a few oocytes of late fetal ovaries and in all oocytes (from primordial to full-grown) in ovaries from juvenile and adult mice. Expression was also observed in ovarian interstitial tissue from 14 days of age onward. Using indirect immunofluorescence, the c-kit protein was detected on the surface of primordial, growing and full-grown oocytes, as well as on embryos at the 1- and 2-cell stages; little remained in blastocysts. In situ hybridization analysis of testes from mice of different ages demonstrated expression in spermatogonia from 6 days of age onward. Using information provided by determining the stage of the cycle of the seminiferous epithelium for a given tubule and by following the age dependence of labeling, it was concluded that the period of expression of c-kit extends from at least as early as type A2 spermatogonia through type B spermatogonia and into preleptotene spermatocytes. Leydig cells were labelled at all ages examined. The expression pattern in oocytes correlates most strongly with oocyte growth and in male germ cells with gonial proliferation.

scholarly journals Role of gonadotrophins in regulating numbers of Leydig and Sertoli cells during fetal and postnatal development in mice

Reproduction ◽  
2001 ◽  
pp. 227-234 ◽  
Author(s):  
PJ Baker ◽  
PJ O'Shaughnessy
Keyword(s):  
Cell Volume ◽  
Postnatal Development ◽  
Leydig Cell ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Normal Values ◽  
Fold Increase ◽  
Adult Mice ◽  
Number Of Cells

The role of the gonadotrophins in regulating numbers of Leydig and Sertoli cells during fetal and postnatal development was examined using normal mice and hypogonadal (hpg) mice, which lack circulating gonadotrophins. The disector method was used to determine the number of cells from day 16 of gestation until adulthood. The numbers of Leydig cells did not change significantly between day 16 of gestation and day 5 after parturition in normal mice and were not significantly different from numbers in hpg mice at any age up to day 5 after parturition. There was a 16-fold increase in the number of Leydig cells in normal mice between day 5 and day 20 after parturition, followed by a further doubling of number of cells between day 20 and adulthood. The number of Leydig cells in hpg testes did not change between day 5 and day 20 after parturition but doubled between day 20 and adulthood so that the number of cells was about 10% of normal values from day 20 onwards. Leydig cell volume was constant in normal animals from birth up to day 20 and then showed a 2.5-fold increase in adult animals. Leydig cell volume was normal in hpg testes at birth but decreased thereafter and was about 20% of normal volume in adult mice. The number of Sertoli cells increased continuously from day 16 of gestation to day 20 after gestation in normal mice and then remained static until adulthood. The number of Sertoli cells in hpg testes was normal throughout fetal life but was reduced by about 30% on day 1 (day of parturition). Thereafter, Sertoli cells proliferated at a slower rate but over a longer period in the hpg testis so that on day 20 after parturition the number of Sertoli cells was about 50% of normal values, whereas in adult mice the number was 65% of normal. The number of gonocytes did not change between day 16 of gestation and day 1 and did not differ between normal and hpg testes. The number of gonocytes increased nine-fold in normal testes but only three-fold in hpg testes between day 1 and day 5 after parturition. Gonocytes differentiated into spermatogonia in both normal and hpg testes between day 5 and day 20 after parturition. These results show: (i) that fetal development of both Sertoli and Leydig cells is independent of gonadotrophins; (ii) that normal differentiation and proliferation of the adult Leydig cell population (starting about day 10 after parturition) is dependent on the presence of gonadotrophins; and (iii) that the number of Sertoli cells after birth is regulated by gonadotrophins, although proliferation will continue, at a lower rate and for longer, in the absence of gonadotrophins.

Role of c-kit in mouse spermatogenesis: identification of spermatogonia as a specific site of c-kit expression and function

Development ◽  
1991 ◽  
Vol 113 (2) ◽  
pp. 689-699 ◽  
Author(s):  
K. Yoshinaga ◽  
S. Nishikawa ◽  
M. Ogawa ◽  
S. Hayashi ◽  
T. Kunisada ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Type A ◽  
Tyrosine Kinase Receptor ◽  
Postnatal Life ◽  
Adult Mice ◽  
Undifferentiated Type ◽  
Type A Spermatogonia

Recent studies have shown that the dominant white spotting (W) locus encodes the proto-oncogene c-kit, a member of the tyrosine kinase receptor family. One symptom of mice bearing mutation within this gene is sterility due to developmental failure of the primordial germ cells during early embryogenesis. To elucidate the role of the c-kit in gametogenesis, we used an anti-c-kit monoclonal antibody, ACK2, as an antagonistic blocker for c-kit function to interfere with the development of male and female germ cells during postnatal life. ACK2 enabled us to detect the expression of c-kit in the gonadal tissue and also to determine the functional status of c-kit, which is expressed on the surface of a particular cell lineage. Consistent with our immunohistochemical findings, the intravenous injection of ACK2 into adult mice caused a depletion in the differentiating type A spermatogonia from the testis during 24–36 h, while the undifferentiated type A spermatogonia were basically unaffected. Intraperitoneal injections of ACK2 into prepuberal mice could completely block the mitosis of mature (differentiating) type A spermatogonia, but not the mitosis of the gonocytes and primitive type A spermatogonia, or the meiosis of spermatocytes. Our results indicate that the survival and/or proliferation of the differentiating type A spermatogonia requires c-kit, but the primitive (undifferentiated) type A spermatogonia or spermatogenic stem cells are independent from c-kit. Moreover, the antibody administration had no significant effect on oocyte maturation despite its intense expression of c-kit.

scholarly journals Role of the tubulin-microtubule system in lymphocyte activation

1977 ◽  
Vol 74 (2) ◽  
pp. 371-376 ◽  
Author(s):  
P Sherline ◽  
GR Mundy
Keyword(s):  
Dna Synthesis ◽  
Human Peripheral Blood ◽  
Lymphocyte Activation ◽  
Fold Increase ◽  
Microtubule Assembly ◽  
Total Protein Content ◽  
Blood Leukocytes ◽  
Sequence Of Events ◽  
Tubulin Content

The role of the tubulin-microtubule system was examined in human peripheral blood leukocytes after activation with phytohemagglutinin (PHA). Soluble tubulin and microtubules were measured with a [(3)H]colchicine-binding assay. It was found that the tubulin content of PHA-activated lymphocytes was consistently increased relative to total protein content after 36 h of culture. There was no increase in the proportion of total tubulin synthesis which was present as microtubules at 36 h. Nevertheless, as a result of increased tubulin synthesis, there was a two-to three-fold increase in total microtubular mass. Colchicine, which disrupts microtubles, was used to assess the role of microtubule assembly in the sequence of events which follow lymphocyte activation, namely lymphokine release, protein synthesis, RNA synthesis, and DNA synthesis. Colchicine consistently inhibited DNA synthesis but did not inhibit release of the lymphokine, osteoclast activating factor (OAF). Protein and RNA syntheses were inhibited much less than DNA synthesis. The fact that some effects of PHA on lymphocytes appear to require intact microtubules and at least one does not suggest that the microtubule dependent step in PHA-stimulated lymphocyte activation occurs at a stage after propagation of the signal from the membrane to the cell interior.

scholarly journals Most regions of mouse epididymis are able to phagocytose immature germ cells

Reproduction ◽  
2013 ◽  
Vol 146 (5) ◽  
pp. 481-489 ◽  
Author(s):  
P Ramos-Ibeas ◽  
E Pericuesta ◽  
R Fernández-González ◽  
M A Ramírez ◽  
A Gutierrez-Adan
Keyword(s):  
Germ Cells ◽  
Fluorescent Protein ◽  
Sperm Quality ◽  
Phagocytic Capacity ◽  
Adult Mice ◽  
Deleted In Azoospermia ◽  
Control Organ ◽  
Green Fluorescent ◽  
Mouse Epididymis

The role of the epididymis as a quality control organ in preventing infertile gametes entering the ejaculate has been extensively explored, and it has been suggested that a specific region of mammalian epididymis is able to phagocytose abnormal germ cells. This study examines whether the epithelium of certain zones of the mouse epididymis can act as a selection barrier by removing immature germ cells from the lumen by phagocytosis. To detect the presence of immature germ cells in the epididymis, we generated transgenic mice expressing enhanced green fluorescent protein under the deleted in azoospermia-like (mDazl) promoter to easily identify immature germ cells under fluorescence microscopy. Using this technique, we observed that during the first stage of spermatogenesis in prepuberal mice, a wave of immature germ cells is released into the epididymis and that the immature epididymis is not able to react to this abnormal situation. By contrast, when immature germ cells were artificially released into the epididymis in adult mice, a phagocytic response was observed. Phagosomes appeared inside principal cells of the epididymal epithelium and were observed to contain immature germ cells at different degradation stages in different zones of the epididymis, following the main wave of immature germ cells. In this paper, we describe how the epididymal epithelium controls sperm quality by clearing immature germ cells in response to their artificially induced massive shedding into the epididymal lumen. Our observations indicate that this phenomenon is not restricted to a given epididymis region and that phagocytic capacity is gradually acquired during epididymal development.

Plasminogen Activation In Vivo upon Intravenous Infusion of DDAVP

1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack
Keyword(s):  
Monoclonal Antibodies ◽  
Plasminogen Activator ◽  
Plasma Levels ◽  
Fold Increase ◽  
Fibrinolytic System ◽  
Plasminogen Activation ◽  
Plasminogen Activator Activity ◽  
Insight Into

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.

The role of clomiphene citrate in the resolution of hypogonadism in male patients with prolactinomas under cabergoline therapy

2018 ◽  
Author(s):  
Lucio Vilar ◽  
Clarice Vilar ◽  
Ruy Lyra ◽  
Ana Carolina The ◽  
Erik Trovao ◽  
...  
Keyword(s):  
Clomiphene Citrate ◽  
Male Patients

A Developmental Perspective on the Genetic Basis of Alcohol Use Disorder

2018 ◽  
Author(s):  
Elisa M. Trucco ◽  
Gabriel L. Schlomer ◽  
Brian M. Hicks
Keyword(s):  
Alcohol Use ◽  
Alcohol Use Disorder ◽  
Developmental Perspective ◽  
Relative Contribution ◽  
Intermediate Phenotypes ◽  
Problematic Alcohol ◽  
Age Related ◽  
Genetic And Environmental Factors ◽  
Problematic Alcohol Use

Approximately 48–66% of the variation in alcohol use disorders is heritable. This chapter provides an overview of the genetic influences that contribute to alcohol use disorder within a developmental perspective. Namely, risk for problematic alcohol use is framed as a function of age-related changes in the relative contribution of genetic and environmental factors and an end state of developmental processes. This chapter discusses the role of development in the association between genes and the environment on risk for alcohol use disorder. Designs used to identify genetic factors relevant to problematic alcohol use are discussed. Studies examining developmental pathways to alcohol use disorder with a focus on endophenotypes and intermediate phenotypes are reviewed. Finally, areas for further investigation are offered.

scholarly journals The SOS Error-Prone DNA Polymerase V Mutasome and β-Sliding Clamp Acting in Concert on Undamaged DNA and during Translesion Synthesis

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1083
Author(s):  
Adhirath Sikand ◽  
Malgorzata Jaszczur ◽  
Linda B. Bloom ◽  
Roger Woodgate ◽  
Michael M. Cox ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Pathogenic Bacteria ◽  
Fold Increase ◽  
Translesion Dna Synthesis ◽  
Sliding Clamp ◽  
Pol V ◽  
Dna Polymerase V ◽  
Acting In Concert

In the mid 1970s, Miroslav Radman and Evelyn Witkin proposed that Escherichia coli must encode a specialized error-prone DNA polymerase (pol) to account for the 100-fold increase in mutations accompanying induction of the SOS regulon. By the late 1980s, genetic studies showed that SOS mutagenesis required the presence of two “UV mutagenesis” genes, umuC and umuD, along with recA. Guided by the genetics, decades of biochemical studies have defined the predicted error-prone DNA polymerase as an activated complex of these three gene products, assembled as a mutasome, pol V Mut = UmuD’2C-RecA-ATP. Here, we explore the role of the β-sliding processivity clamp on the efficiency of pol V Mut-catalyzed DNA synthesis on undamaged DNA and during translesion DNA synthesis (TLS). Primer elongation efficiencies and TLS were strongly enhanced in the presence of β. The results suggest that β may have two stabilizing roles: its canonical role in tethering the pol at a primer-3’-terminus, and a possible second role in inhibiting pol V Mut’s ATPase to reduce the rate of mutasome-DNA dissociation. The identification of umuC, umuD, and recA homologs in numerous strains of pathogenic bacteria and plasmids will ensure the long and productive continuation of the genetic and biochemical journey initiated by Radman and Witkin.

Health research capacity in Nepal: Analysis of the trend and the role of local researchers

2021 ◽  
pp. 004947552098277
Author(s):  
Madhu Kharel ◽  
Alpha Pokharel ◽  
Krishna P Sapkota ◽  
Prasant V Shahi ◽  
Pratisha Shakya ◽  
...  
Keyword(s):  
Health Research ◽  
Fold Increase ◽  
Research Capacity ◽  
Rapid Review ◽  
Evidence Based ◽  
Middle Income ◽  
Middle Income Countries ◽  
Health Related ◽  
Evidence Based Decision Making

Evidence-based decision-making is less common in low- and middle-income countries where the research capacity remains low. Nepal, a lower-middle-income country in Asia, is not an exception. We conducted a rapid review to identify the trend of health research in Nepal and found more than seven-fold increase in the number of published health-related articles between 2000 and 2018. The proportion of articles with Nepalese researchers as the first authors has also risen over the years, though they are still only in two-thirds of the articles in 2018.

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