Insulin regulates primordial-follicle assembly in vitro by affecting germ-cell apoptosis and elevating oestrogen

2015 ◽  
Vol 27 (8) ◽  
pp. 1197 ◽  
Author(s):  
Xin-Lei Feng ◽  
Yuan-Chao Sun ◽  
Min Zhang ◽  
Shun-Feng Cheng ◽  
Yan-Ni Feng ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Apoptosis ◽  
Culture Medium ◽  
Insulin Treatment ◽  
Ovarian Function ◽  
Primordial Follicle ◽  
Germ Cell Apoptosis ◽  
Germ Cell Cysts ◽  
Culture Model

Insulin is a protein secreted by pancreatic β-cells, which plays an important role in the regulation of ovarian function. However, the specific molecular mechanism of its function remains largely unknown. This study aimed to assess the effect of insulin on mouse folliculogenesis using an in vitro ovary-culture model. The results demonstrated that insulin promoted the proliferation of ovarian granulosa cells in vitro, and thereby accelerated the progress of folliculogenesis (the percentage of oocytes in cysts declined from 42.6% to 29.3%); however, the percentage of apoptotic oocytes increased after insulin treatment. Further investigation indicated that apoptosis occurred mainly in germ-cell cysts. After 3 days of insulin treatment, oestrogen in the culture medium of mouse ovaries significantly increased (P < 0.01), while the lower dose of oestrogen promoted primordial-follicle assembly in vitro. In conclusion, insulin promoted folliculogenesis by facilitating germ-cell apoptosis within the cysts and upregulating oestrogen levels.

Regulation of human male germ cell death by modulators of ATP production

2006 ◽  
Vol 290 (6) ◽  
pp. E1145-E1154 ◽  
Author(s):  
Krista Erkkila ◽  
Sauli Kyttanen ◽  
Marten Wikstrom ◽  
Kimmo Taari ◽  
Amiya P. Sinha Hikim ◽  
...  
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Cell Apoptosis ◽  
Male Germ Cell ◽  
Germ Cell Apoptosis ◽  
Atp Production ◽  
Mitochondrial Inhibitors ◽  
Human Male ◽  
Induced Apoptosis

The understanding of testicular physiology, pathology, and male fertility issues requires knowledge of male germ cell death and energy production. Here, we induced human male germ cell apoptosis (detected by Southern blot analysis of DNA fragmentation, TUNEL, activation of caspases-3 and -9, and electron microscopy) by incubating seminiferous tubule segments under hormone- and serum-free conditions. Inhibitors of complexes I to IV of mitochondrial respiration, exposure to anoxia, and inhibition of F0F1-ATPase (with oligomycin) decreased the ATP levels (analyzed by HPLC) and suppressed apoptosis at 4 h. Uncoupler 2,4-dinitrophenol (DNP) and oligomycin combination also suppressed death at 4 h, as did the DNP alone. Inhibition of glycolysis by 2-deoxyglucose neither suppressed nor further induced apoptosis nor altered the antiapoptotic effects of the mitochondrial inhibitors. Furthermore, Fas system activation did not modify the effects of mitochondrial modulators. After 24 h, delayed male germ cell apoptosis was observed despite the presence of the mitochondrial inhibitors. We conclude that the mitochondrial ATP production machinery plays an important role in regulating in vitro-induced primary pathways of human male germ apoptosis. The ATP synthesized by the F0F1-ATPase seems to be the crucial death regulator, rather than any of the complexes (I-IV) alone, the functional electron transport chain, or the membrane potential. We also conclude that there seem to be secondary pathways of human testicular cell apoptosis that do not require mitochondrial ATP production. The present study emphasizes the role of the main catabolic pathways in the complex network of regulating events of male germ cell life and death.

Fas regulates germ cell apoptosis in the human testis in vitro

1999 ◽  
Vol 276 (2) ◽  
pp. E310-E316 ◽  
Author(s):  
Virve Pentikäinen ◽  
Krista Erkkilä ◽  
Leo Dunkel
Keyword(s):  
Germ Cell ◽  
Cell Apoptosis ◽  
Fas Ligand ◽  
Present Report ◽  
Human Testis ◽  
Seminiferous Tubules ◽  
Caspase Inhibitor ◽  
Germ Cell Apoptosis

The Fas-Fas ligand (FasL) system has been implicated in maintaining the immune privileged nature of the testis. The present report concerns the role of the Fas-FasL system in regulating germ cell apoptosis, another important function of this system in the human testis. Fas was localized immunohistochemically to the same types of germ cells that were identified as apoptotic, namely spermatocytes and spermatids. Strong expression of Fas was also observed in Western blot analysis of the human testis. Furthermore, an antagonistic antibody to the FasL blocked germ cell apoptosis induced in vitro by incubating segments of seminiferous tubules under serum- and hormone-free conditions (i.e., without survival factors). Thus Fas appears to mediate germ cell apoptosis. A universal caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone, also inhibited germ cell death, suggesting that Fas-associated germ cell apoptosis is mediated via the caspase pathway. The present results suggest an important role for the Fas-FasL system in the regulation of germ cell apoptosis in the human testis.

scholarly journals Assisted reproduction with in-vitro-cultured testicular spermatozoa in cases of severe germ cell apoptosis: a pilot study

2001 ◽  
Vol 16 (12) ◽  
pp. 2640-2645 ◽  
Author(s):  
Jan Tesarik ◽  
Ermanno Greco ◽  
Carmen Mendoza
Keyword(s):  
Pilot Study ◽  
Germ Cell ◽  
Assisted Reproduction ◽  
Cell Apoptosis ◽  
Germ Cell Apoptosis ◽  
Testicular Spermatozoa

scholarly journals Arsenic inhibits in vitro spermatogenesis and induces germ cell apoptosis in Japanese eel (Anguilla japonica)

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 279-287 ◽  
Author(s):  
Fritzie T Celino ◽  
Sonoko Yamaguchi ◽  
Chiemi Miura ◽  
Takeshi Miura
Keyword(s):  
Germ Cell ◽  
Cell Apoptosis ◽  
Oxidative Dna Damage ◽  
Arsenic Concentration ◽  
Anguilla Japonica ◽  
Japanese Eel ◽  
World Health ◽  
Low Doses ◽  
Germ Cell Apoptosis

The precise mechanism and direct effects of arsenic on fish, particularly in reproduction, are not well clarified. The aim of this study is to investigate the direct influence of arsenic on fish spermatogenesis using the Japanese eel (Anguilla japonica)in vitrotesticular organ culture system. Eel testicular fragments were culturedin vitrowith 0.1–100 μM arsenic with or without human chorionic gonadotropin (hCG) for 6 or 15 days at 20 °C. Arsenic treatment provoked a dose-dependent inhibition of hCG-induced germ cell proliferation as revealed by 5-bromo-2-deoxyuridine immunohistochemistry. Time-resolved fluorescent immunoassay showed that arsenic suppressed hCG-induced synthesis of 11-ketotestosterone (11-KT) in testicular fragments incubated with 0.0001–100 μM arsenic and hCG for 18 h. A 0.1 μM (7 μg/l) dose of arsenic which is lower than the World Health Organization drinking water quality guideline of 10 μg/l most effectively reduced 11-KT production. The hCG-induced synthesis of progesterone from pregnenolone was significantly inhibited by low doses of arsenic (0.1–1 μM), implying an inhibition of 3β-hydroxysteroid dehydrogenase activity.In situTUNEL assays indicated that germ cells undergo apoptosis at the highest dose of arsenic (100 μM). An arsenic concentration-dependent increase in oxidative DNA damage was detected by 8-hydroxy-2′-deoxyguanosine (8-OHdG) immunohistochemistry. A peak in 8-OHdG index was observed in testicular fragments treated with 100 μM arsenic and hCG consistent with the TUNEL results. These data suggest that low doses of arsenic may inhibit spermatogenesis via steroidogenesis suppression, while high doses of arsenic induce oxidative stress-mediated germ cell apoptosis.

scholarly journals Silica nanoparticles enhance germ cell apoptosis by inducing reactive oxygen species (ROS) formation in Caenorhabditis elegans

2020 ◽  
Vol 45 (3) ◽  
pp. 117-129 ◽  
Author(s):  
Fangfang Zhang ◽  
Xinyue You ◽  
Tengteng Zhu ◽  
Sumeng Gao ◽  
Yu Wang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Silica Nanoparticles ◽  
Cell Apoptosis ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Germ Cell Apoptosis ◽  
Ros Formation

Bcl-2 and Bax are involved in experimental cryptorchidism-induced testicular germ cell apoptosis in rhesus monkey

Contraception ◽  
2003 ◽  
Vol 68 (4) ◽  
pp. 297-301 ◽  
Author(s):  
Zhi-Hong Zhang ◽  
Xuan Jin ◽  
Xue-Sen Zhang ◽  
Zhao-Yuan Hu ◽  
Ru-Jin Zou ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Germ Cell ◽  
Cell Apoptosis ◽  
Testicular Germ Cell ◽  
Germ Cell Apoptosis
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