scholarly journals Establishment of A Reversibly Inducible Porcine Granulosa Cell Line

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 156 ◽  
Author(s):  
Yinshan Bai ◽  
Cui Zhu ◽  
Meiying Feng ◽  
Bo Pan ◽  
Shouquan Zhang ◽  
...  

Granulosa cells (GCs) are the key components of ovarian follicles for regulating oocyte maturation. Previous established GC lines have allowed prolonged proliferation, but lost some physiological features owing to long-term immortalization. This study was to establish an induced immortal porcine GC line with reversible proliferation status by the tetracycline inducible (Tet-on) 3G system. Our conditional immortal porcine GCs (CIPGCs) line steadily propagated for at least six months and displayed primary GC morphology when cultured in the presence of 50 ng/mL doxycycline [Dox (+)]. Upon Dox withdrawal [Dox (–)], Large T-antigen expression, reflected by mCherry fluorescence, gradually became undetectable within 48 h, accompanied by less proliferation and size increase. The levels of estradiol and progesterone, and the expression of genes associated with steroid production, such as CYP11A1 (cytochrome P450 family 11), 3β-HSD (3β-hydroxysteroid dehydrogenase), StAR (steroidogenic acute regulatory protein), and CYP19A1 (cytochrome P450 family 19 subfamily a member 1), were all significantly higher in the Dox (–) group than Dox (+) group. The CIPGCs could switch into a proliferative state upon Dox induction. Interestingly, the expression of StAR and CYP19A1 in the CIPGCs (–Dox) was significantly increased by adding porcine follicular fluid (PFF) to mimic an ovary follicle environment. Moreover, PFF priming the CIPGCs in Dox (–) group resulted in similar estradiol production as that of primary GC, and enabled this cell line to respond to gonadotrophins in estradiol production. Collectively, we have established an inducible immortal porcine GC line, which offers a unique and valuable model for future research on the regulation of ovarian functions.

2013 ◽  
Vol 394 (7) ◽  
pp. 909-918 ◽  
Author(s):  
Srividya Vasu ◽  
Neville H. McClenaghan ◽  
Jane T. McCluskey ◽  
Peter R. Flatt

Abstract The novel insulin-secreting human pancreatic β-cell line, 1.1B4, demonstrates stability in culture and many of the secretory functional attributes of human pancreatic β-cells. This study investigated the cellular responses of 1.1B4 cells to lipotoxicity. Chronic 18-h exposure of 1.1B4 cells to 0.5 mm palmitate resulted in decreased cell viability and insulin content. Secretory responses to classical insulinotropic agents and cellular Ca2+ handling were also impaired. Palmitate decreased glucokinase activity and mRNA expression of genes involved in secretory function but up-regulated mRNA expression of HSPA5, EIF2A, and EIF2AK3, implicating activation of the endoplasmic reticulum stress response. Palmitate also induced DNA damage and apoptosis of 1.1B4 cells. These responses were accompanied by increased gene expression of the antioxidant enzymes SOD1, SOD2, CAT and GPX1. This study details molecular mechanisms underlying lipotoxicity in 1.1B4 cells and indicates the potential value of the novel β-cell line for future research.


Endocrinology ◽  
2012 ◽  
Vol 153 (6) ◽  
pp. 2851-2860 ◽  
Author(s):  
Bayasula ◽  
Akira Iwase ◽  
Tohru Kiyono ◽  
Sachiko Takikawa ◽  
Maki Goto ◽  
...  

The ovary is a complex endocrine organ responsible for steroidogenesis and folliculogenesis. Follicles consist of oocytes and two primary steroidogenic cell types, the granulosa cells, and the theca cells. Immortalized human granulosa cells are essential for researching the mechanism of steroidogenesis and folliculogenesis. We obtained granulosa cells from a 35-yr-old female and immortalized them by lentivirus-mediated transfer of several genes so as to establish a human nonluteinized granulosa cell line (HGrC1). We subsequently characterized HGrC1 and investigated its steroidogenic performance. HGrC1 expressed enzymes related to steroidogenesis, such as steroidogenic acute regulatory protein, CYP11A, aromatase, and gonadotropin receptors. Stimulation with FSH increased the mRNA levels of aromatase, which consequently induced the aromatization of androstenedione to estradiol. Activin A increased the mRNA levels of the FSH receptor, which were synergistically up-regulated with FSH stimulation. HGrC1 also expressed a series of ligands and receptors belonging to the TGF-β superfamily. A Western blot analysis showed that bone morphogenetic protein (BMP)-4, BMP-6, and BMP-7 phosphorylated small mother against decapentaplegic (Smad)1/5/8, whereas growth differentiation factor-9 phosphorylated Smad2/3. BMP-15 and anti-Müllerian hormone phosphorylated Smad1/5/8 while also weakly phosphorylating Smad2/3. These results indicate that HGrC1 may possess the characteristics of granulosa cells belonging to follicles in the early stage. HGrC1 might also be capable of displaying the growth transition from a gonadotropin-independent status to gonadotropin-dependent one.


Reproduction ◽  
2000 ◽  
pp. 251-262 ◽  
Author(s):  
CA Price ◽  
GM Cooke ◽  
LM Sanford

The regulation of LH-dependent and -independent increases in testosterone secretion by key proteins in the testes of adult rams was investigated. Serial blood samples were collected from groups of four control and passively immunized (oestradiol antiserum for 3 weeks) rams and the animals were gonadectomized in either the non-breeding season (April) or the breeding season (September). LH pulse frequency and basal (interpulse) concentrations were several times greater (P < 0.01) in the breeding season than in the non-breeding season. Neither of these parameters nor LH pulse amplitude were affected by oestradiol immunization. Parameters of testosterone episodic secretion and response to an injection (i.v.) of 15 micrograms NIH-LH-S25 were also greater (P < 0.05) in the breeding season and, with the exception of pulse frequency, in immunized rams versus controls. Substrate utilization established that testosterone biosynthesis was predominantly via the 5-ene pathway. Increases in blood testosterone concentration in the breeding season were associated with a fivefold higher (P < 0.01) activity of cytochrome P450 17alpha-hydroxylase/C-17,20 lyase (P450(17alpha)) and a 65% higher (P < 0.05) relative amount of mRNA for cytochrome P450 cholesterol side-chain cleavage enzyme complex (P450scc) in the testis. Of the steroidogenic enzyme activities examined, only that for 17beta-hydroxysteroid dehydrogenase (17beta-HSD) tended to be increased by oestradiol immunization. Blood concentrations of cholesterol lipoproteins and expression of the testicular low density lipoprotein receptor were not affected by season or immunization. The amount of steroidogenic acute regulatory protein (StAR) mRNA was 65% higher (P < 0.01) in the breeding season and 20% higher (P < 0.01) in immunized rams versus controls. These results indicate that greater LH stimulation may increase testosterone biosynthesis in the breeding season by increasing StAR mRNA (and presumably delivery of cholesterol to P450scc) and the activity of P450(17alpha), and possibly that of P450scc (activity not measured). More moderate increases in StAR mRNA and 17beta-HSD activity may explain, in part, the increases in testosterone secretion with oestradiol immunization.


2000 ◽  
pp. 294-299 ◽  
Author(s):  
S Zenkert ◽  
B Schubert ◽  
M Fassnacht ◽  
F Beuschlein ◽  
B Allolio ◽  
...  

The rate limiting step in steroidogenesis is cholesterol transport through the outer to the inner mitochondrial membrane and the cytochrome P450 side chain cleavage (P450scc) complex. The protein factor responsible for this transport, and as such necessary for regulating the acute production of steroids, has been identified and named the steroidogenic acute regulatory protein (StAR). We investigated the expression of StAR in functional and non-functional adrenal neoplasms and compared the expression with that of P450scc. Poly A RNA was extracted from normal adrenal glands (NAG, n=5), aldosterone producing adenomas (APA, n=4), cortisol producing adenomas (CPA, n=5), adrenocortical carcinomas (ACC, n=6) and non-functional adenomas (NFA, n=3), electrophoresed through a 1% agarose gel, blotted and hybridised with a PCR-generated cDNA labelled with [(32)P]CTP. The blots were stripped and re-hybridised with a P450scc cDNA and a mouse beta-actin probe. Compared with P450scc, StAR mRNA expression showed little variability in the magnitude of expression and did not correlate with the endocrine profiles (NAG: StAR 100+/-16%, P450scc 100+/-14%; APA: StAR 80+/-3%, P450scc 94+/-13%; CPA: StAR 71+/-10%, P450scc 109+/-15%; NFA: StAR 64+/-9.5%, P450scc 18+/-5%; means+/-s.e.m.). ACC expressed low levels of both genes probably as a result of dedifferentiation (StAR 29+/-9%, P450scc 46+/-18%). Incubation of the NCI-h295 tumour cell line with 10nmol ACTH and 10micromol forskolin induced an increase in the abundance of StAR and P450scc mRNA, demonstrating gene regulation by the cAMP protein kinase A pathway. Furthermore, we incubated the NCI-h295 tumour cell line with the adrenostatic compounds, aminoglutethimide and metyrapone. We could not detect an effect on the expression of StAR mRNA, whereas the expression of P450scc mRNA was significantly reduced. We conclude that, in contrast to P450scc, StAR seems to be evenly expressed in adrenocortical adenomas. Therefore, the endocrine activity of a given tumour cannot be explained by the abundance of StAR expression. In ACC, both StAR and P450scc expression is low, explaining the relatively inefficient steroid production of these tumours.


2008 ◽  
Vol 294 (3) ◽  
pp. R711-R719 ◽  
Author(s):  
Derek Alsop ◽  
Mathilakath M. Vijayan

Using zebrafish embryos and larvae, we examined the temporal patterns of cortisol and expression of genes involved in corticosteroid synthesis and signaling. Embryonic cortisol levels decreased ∼70% from 1.5 h postfertilization (hpf) to hatch (∼42 hpf) and then increased 27-fold by 146 hpf. The mRNA abundances of steroidogenic acute regulatory protein, 11β-hydroxylase and 11β-hydroxysteroid dehydrogenase type 2, increased severalfold after hatch and preceded the rise of cortisol levels. In contrast to other teleosts that possess two glucocorticoid receptors (GRs) and one mineralocorticoid receptor (MR), only one GR and MR were identified in zebrafish, which were cloned and sequenced. GR mRNA abundance decreased from 1.5 to 25 hpf, rebounded, and then was stable from 49 to 146 hpf. MR transcripts increased continuously from 1.5 hpf and were 52-fold higher by 97 hpf. An acute cortisol response to a stressor was not detected until 97 hpf, whereas melanocortin type 2 receptor mRNA increased between 25 and 49 hpf. Collectively, the patterns of cortisol and the expression of cortisol biosynthetic genes and melanocortin type 2 receptor suggest that the corticoid stress axis in zebrafish is fully developed only after hatch. The temporal differences in GR, MR, and 11β-hydroxysteroid dehydrogenase type 2 gene expression lead us to propose a key role for MR signaling by maternal cortisol during embryogenesis, whereas cortisol secretion after hatch may be regulating GR expression and signaling in zebrafish.


2001 ◽  
Vol 15 (8) ◽  
pp. 1264-1276 ◽  
Author(s):  
Xing-zi Lin ◽  
Hiroshi Takemori ◽  
Yoshiko Katoh ◽  
Junko Doi ◽  
Nanao Horike ◽  
...  

Abstract The involvement of salt-inducible kinase, a recently cloned protein serine/threonine kinase, in adrenal steroidogenesis was investigated. When Y1 mouse adrenocortical tumor cells were stimulated by ACTH, the cellular content of salt-inducible kinase mRNA, protein, and enzyme activity changed rapidly. Its level reached the highest point in 1–2 h and returned to the initial level after 8 h. The mRNA levels of cholesterol side-chain cleavage cytochrome P450 and steroidogenic acute regulatory protein, on the other hand, began to rise after a few hours, reaching the highest levels after 8 h. The salt-inducible kinase mRNA level in ACTH-, forskolin-, or 8-bromo-cAMP-treated Kin-7 cells, mutant Y1 with less cAMP-dependent PKA activity, remained low. However, Kin-7 cells, when transfected with a PKA expression vector, expressed salt-inducible kinase mRNA. Y1 cells that overexpressed salt-inducible kinase were isolated, and the mRNA levels of steroidogenic genes in these cells were compared with those in the parent Y1. The level of cholesterol side-chain cleavage cytochrome P450 mRNA in the salt-inducible kinase-overexpressing cells was markedly low compared with that in the parent, while the levels of Ad4BP/steroidogenic factor-1-, ACTH receptor-, and steroidogenic acute regulatory protein-mRNAs in the former were similar to those in the latter. The ACTH-dependent expression of cholesterol side-chain cleavage cytochrome P450- and steroidogenic acute regulatory protein-mRNAs in the salt-inducible kinase-overexpressing cells was significantly repressed. The promoter activity of the cholesterol side-chain cleavage cytochrome P450 gene was assayed by using Y1 cells transfected with a human cholesterol side-chain cleavage cytochrome P450 promoter-linked reporter gene. Addition of forskolin to the culture medium enhanced the cholesterol side-chain cleavage cytochrome P450 promoter activity, but the forskolin-dependently activated promoter activity was inhibited when the cells were transfected with a salt-inducible kinase expression vector. This inhibition did not occur when the cells were transfected with a salt-inducible kinase (K56M) vector that encoded an inactive kinase. The salt-inducible kinase’s inhibitory effect was also observed when nonsteroidogenic, nonAd4BP/steroidogenic factor-1 -expressing, NIH3T3 cells were used for the promoter assays. These results suggested that salt-inducible kinase might play an important role(s) in the cAMP-dependent, but Ad4BP/steroidogenic factor-1-independent, gene expression of cholesterol side-chain cleavage cytochrome P450 in adrenocortical cells.


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