scholarly journals ID: 1039 The antidepressant fluoxetine inhibits adenylate cyclase stimulation by FSH or Forskolin in the COV434 human ovarian granulosa tumor cell line

2017 ◽  
Vol 4 (S) ◽  
pp. 117
Author(s):  
Thi Mong Diep Nguyen ◽  
Danièle Klett ◽  
Minh Thu Vo ◽  
Yves Combarnous

Fluoxetine (Prozac), a selective Serotonin Reuptake Inhibitor antidepressant, exhibits other mechanisms of action in various cell types and has been shown to induce cell death in cancer cells, paving the way for its potential use in cancer therapy. The ovary is a complex endocrine organ responsible for steroidogenesis and folliculogenesis, and human granulosa cells are essential for scientific research to improve the understanding of these two processes. However, little is known about fundamental signaling pathways in human granulosa cells. In this study, we investigated the dynamics of intracellular cyclic adenosine monophosphate AMP, a conserved signaling messenger that can regulate virtually every physiological process. We show that incubating COV434 human ovarian granulosa cells with fluoxetine induces a decrease in intracellular cAMP response to Follicle-stimulating hormone (FSH) and forskolin (FSK). In order to study the intracellular cAMP kinetic responses of COV434 cells to FSH or FSK, we used COV434 cells transiently expressing a chimeric cAMP-responsive luciferase so that real-time variations of intracellular cAMP concentration could be monitored, by using oxiluciferin luminescence produced from catalyzed luciferin oxidation. Our data show that fluoxetine induces an increase in the extracellular Ca2+ entry and reduces ATP concentration as well as cell viability. Targeting these signaling pathways with fluoxetine could permit to get better knowledge in the molecular mechanisms involved in ovarian follicular development

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shang Yang ◽  
Oana M. Constantin ◽  
Divya Sachidanandan ◽  
Hannes Hofmann ◽  
Tobias C. Kunz ◽  
...  

Abstract Background Cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger that transduces extracellular signals in virtually all eukaryotic cells. The soluble Beggiatoa photoactivatable adenylyl cyclase (bPAC) rapidly raises cAMP in blue light and has been used to study cAMP signaling pathways cell-autonomously. But low activity in the dark might raise resting cAMP in cells expressing bPAC, and most eukaryotic cyclases are membrane-targeted rather than soluble. Our aim was to engineer a plasma membrane-anchored PAC with no dark activity (i.e., no cAMP accumulation in the dark) that rapidly increases cAMP when illuminated. Results Using a streamlined method based on expression in Xenopus oocytes, we compared natural PACs and confirmed bPAC as the best starting point for protein engineering efforts. We identified several modifications that reduce bPAC dark activity. Mutating a phenylalanine to tyrosine at residue 198 substantially decreased dark cyclase activity, which increased 7000-fold when illuminated. Whereas Drosophila larvae expressing bPAC in mechanosensory neurons show nocifensive-like behavior even in the dark, larvae expressing improved soluble (e.g., bPAC(R278A)) and membrane-anchored PACs exhibited nocifensive responses only when illuminated. The plasma membrane-anchored PAC (PACmn) had an undetectable dark activity which increased >4000-fold in the light. PACmn does not raise resting cAMP nor, when expressed in hippocampal neurons, affect cAMP-dependent kinase (PKA) activity in the dark, but rapidly and reversibly increases cAMP and PKA activity in the soma and dendrites upon illumination. The peak responses to brief (2 s) light flashes exceed the responses to forskolin-induced activation of endogenous cyclases and return to baseline within seconds (cAMP) or ~10 min (PKA). Conclusions PACmn is a valuable optogenetic tool for precise cell-autonomous and transient stimulation of cAMP signaling pathways in diverse cell types.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Lixian Qin ◽  
Chantacha Sitticharoon ◽  
Rungnapa Sririwichitchai ◽  
Issarawan Keadkraichaiwat ◽  
Pailin Maikaew ◽  
...  

Abstract Kisspeptin has a central role to stimulate the hypothalamic-pituitary-gonadal (HPG) axis. Furthermore, a previous study has suggested that kisspeptin might have a peripheral role in follicular development (1). This study aimed to 1) explore the effect of kisspeptin on CYP19A1 (aromatase) mRNA expression in human granulosa cells and aromatase concentrations in the supernatant; and 2) investigate the effect of kisspeptin on FSHR mRNA expression in human granulosa cells. In this study, human granulosa-like tumor cell line (KGN) (n=3) was incubated for 24 hours with FSH (10-8 M); FSH with IGF-1 (10-8 M); different doses of kisspeptin including 1, 10, 100, 1,000, and 10,000 nM; FSH with different doses of kisspeptin; and FSH with IGF-1 together with different doses of kisspeptin. FSH treatment alone or FSH with IGF-1 did not increase CYP19A1 mRNA expression when compared to control. Interestingly, kisspeptin treatment at the doses of 100 nM (P=0.028), 1,000 nM (P=0.005), and 10,000 nM (P=0.009) in the presence of FSH together with IGF-1 enhanced CYP19A1 mRNA expression when compared with control. Furthermore, FSH or FSH with IGF-1 or FSH with all doses of kisspeptin or FSH with IGF-1 together with all doses of kisspeptin increased aromatase concentrations in the supernatant when compared to control (P<0.01 all). Surprisingly, kisspeptin at the dose of 10,000 nM with FSH or FSH together with IGF-1 statistically increased aromatase concentrations in the supernatant when compared with FSH treatment alone or FSH with IGF-1 treatment (P<0.01 all). FSHR mRNA expression was comparable between control and all treatments. As a result, kisspeptin combined with FSH and IGF-1 could enhance CYP19A1 mRNA expression in human granulosa cells and the high dose of kisspeptin (10,000 nM) might be able to augment aromatase secretion in the supernatant. These results suggest that kisspeptin might enhance aromatase expression and secretion, which probably leads to enhance estrogen synthesis. Further studies regarding kisspeptin treatment on estrogen synthesis or secretion in human granulosa cells should be confirmed. Reference: (1) Fernandois D, et al. J Endocrinol. 2016;228(3):161-70.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoxia Jiang ◽  
Xin Xu ◽  
Mengjie Wu ◽  
Zhonghai Guan ◽  
Xingyun Su ◽  
...  

Aberrant expression of G protein-coupled receptors (GPCRs) is frequently associated with tumorigenesis. G Protein-coupled receptor class C group 5 member A (GPRC5A) is a member of the GPCR superfamily, is expressed preferentially in lung tissues, and is regulated by various entities at multiple levels. GPRC5A exerts a tumor suppressive role in lung cancer and GPRC5A deletion promotes lung tumor initiation and progression. Recent advances have highlighted that GPRC5A dysregulation is found in various human cancers and is related to many tumor-associated signaling pathways, including the cyclic adenosine monophosphate (cAMP), nuclear factor (NF)-κB, signal transducer and activator of transcription (STAT) 3, and focal adhesion kinase (FAK)/Src signaling. This review aimed to summarize our updated view on the biology and regulation of GPRC5A, its expression in human cancers, and the linked signaling pathways. A better comprehension of the underlying cellular and molecular mechanisms of GPRC5A will provide novel insights into its potential diagnostic and therapeutic value.


Author(s):  
Ronald Y. Kwon ◽  
Sara Temiyasathit ◽  
Padmaja Tummala ◽  
Clarence Quah ◽  
Christopher R. Jacobs

It is well accepted that fluid flow is an important mechanical signal in regulating bone structure and function. Primary cilia, which are non-motile, microtubule based organelles that extend from the centrosome and project into extracellular space in many cell types, have recently been shown to mediate fluid flow-induced osteogenic responses in MLO-Y4 osteocyte-like cells [1]. However, primary cilia did not mediate increases in intracellular Ca2+ concentration, and the second messenger system(s) involved in primary cilia-mediated mechanosensing has yet to be elucidated. In this study, our goals were to (1) determine whether exposing bone cells to oscillatory fluid flow modulates intracellular levels of cyclic adenosine monophosphate (cAMP), another ubiquitous second messenger molecule, and (2) investigate whether this modulation may be mediated by primary cilia.


2020 ◽  
Vol 17 (4) ◽  
pp. 595-602
Author(s):  
Nguyen Thi Mong Diep ◽  
Nguyen Thi Bich Hang ◽  
Nguyen Le Cong Minh ◽  
Tran Thanh Son ◽  
Nguyen Thuy Duong

Fluoxetine (FLX), a widely used antidepressant primarily acting as a selective serotonin reuptake inhibitor, has been shown to exhibit other mechanisms of action in various cell types. Cyclic adenosine monophosphate (cAMP) is a second messenger used for intracellular signal induction. Cyclic AMP is a nucleotide synthesized within the cell from adenosine triphosphate by the adenylyl cyclase enzyme, and is inactivated enzymatically to 5′AMP by hydroxylation with a group of enzymes called phosphodiesterase. The aim of this study was to determine the effects of FLX on MLTC-1 Leydig cells on intracellular cyclic AMP response to forskolin (FSK). MLTC-1 cells were incubated at 37°C in media supplemented with or without different doses of FLX (0, 0.156, 0.3125, 0.625, 1.25, 2.5, 5 and 10 µM). We then looked for how the concentration of FLX for a short-time (2 hours) and a long-time (24 hours) affects the concentration of intracellular cyclic AMP response to FSK and ATP levels on MLTC-1 cells. Our results show that FLX decreased the intracellular cAMP response to FSK depending on FLX concentration. FLX decreased significantly cAMP levels only at 10 µM after 2 hours of incubation but after 24 hours of incubation FLX caused an effect on cAMP levels at 5 µM and at 10 µM. Moreover, as expected, FLX also caused a decline of steroidogenesis, which is under the control of cAMP and ATP levels in the cells. Taken together, these findings demonstrate that the inhibition of cAMP synthesis by FLX is dose-dependent, and that FLX also inhibited hormone-induced steroidogenesis in MLTC-1 cells.


2017 ◽  
Vol 41 (1) ◽  
pp. 265-273 ◽  
Author(s):  
Meng Yang ◽  
Xurong Wang ◽  
Lei Wang ◽  
Xuezhi Wang ◽  
Jianxi Li ◽  
...  

Background/Aims: IL-6 is one of the main cytokines in regulating ovarian follicular development and ovulation. However, the factors that regulate IL-6 expression in follicles are still unclear. The aim of this study was to elucidate the mechanisms underlying the effect of IL-1α on IL-6 expression in granulosa cells. Methods: IL-6 expression after IL-1α with/without inhibitors treatment was analyzed by RT-qPCR and ELISA. The phosphorylation of proteins induced by IL-1α was analyzed by western blot. The intracellular cAMP level was assayed by immunoassay kit. Results: IL-1α has a dose-dependent effect on IL-6 expression in granulosa cells. This promoting effect can be significantly attenuated by Erk, c-Jun, p38 and IκB proteins inhibitors, respectively. Moreover, the phosphorylation levels of Erk, c-Jun, p38 and IκBα proteins were significantly increased after IL-1α treatment. In addition, we also found that IL-1α not only reversed the cAMP attenuated IL-6 expression, but also increased IL-1α mRNA expression in granulosa cells. Conclusion: The regulation of IL-1α on IL-6 expression is mediated by activation of MAPKs and NF-κB signaling pathways. Moreover,IL-1α may regulate the ovulation-related genes expression in granulosa cells by an autocrine and/or paracrine manner.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hai-Yun Guan ◽  
He-Xia Xia ◽  
Xiu-Ying Chen ◽  
Lu Wang ◽  
Zhi-Jing Tang ◽  
...  

Toll-like receptor 4 (TLR4) may play a critical role in regulating follicular development. Data are scarce on the role of TLR4 in the follicle. This study investigated the effects of TLR4 on steroidogenesis in human granulosa cells. Immunohistochemical analysis revealed stage-specific expression of TLR4 in the mouse ovarian cycle, and immunofluorescence showed TLR4 expression in the human granulosa-like tumor cell line (KGN). TLR4 agonist lipopolysaccharides (LPS) significantly inhibited follicular development and synthesis of estradiol (E2) in mice. In KGN cells, TLR4 activation significantly inhibited CYP19A1, FSHR and StAR, and TLR4 inhibition reversed these effects. TLR4 activation also inhibited forskolin-induced secretion of E2 by inhibiting CYP19A1, with no effect on progesterone. Further studies showed activation of p38, JNK and NF-κB signaling after TLR4 activation. Subsequent analyses showed that an NF-κB antagonist reversed the inhibitory effects on CYP19A1 expression and E2 secretion. Together, our results suggest that TLR4 activation may suppress CYP19A1 expression and E2 secretion via NF-κB signaling in human granulosa cells, with important implications for the regulation of ovarian pathophysiology.


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