Role of Akt and mammalian target of rapamycin signalling in insulin-like growth factor 1-mediated cell proliferation in porcine Sertoli cells

2020 ◽  
Vol 32 (10) ◽  
pp. 929
Author(s):  
Chinju Johnson ◽  
John Kastelic ◽  
Jacob Thundathil
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Cholesterol Biosynthesis ◽  
Critical Role ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Insulin Like Growth Factor

The critical role of insulin-like growth factor (IGF) 1 in promoting Sertoli cell proliferation invivo and invitro has been established, but its downstream signalling mechanisms remain unknown. In addition to mitogenic effects, a role for IGF1 in mediating cholesterol biosynthesis within testes has been implied. The aims of this study were to investigate the roles of: (1) phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) signalling in IGF1-mediated Sertoli cell proliferation; and (2) IGF1 in mediating cholesterol biosynthesis in Sertoli cells. Primary cultures of Sertoli cells were prepared from 1-week-old porcine testes. On Day 3 of culture, Sertoli cells were treated with 300ng mL−1 IGF1, alone or in combination with inhibitors of IGF1 receptor (2μM picropodophyllotoxin), Akt (1μM wortmannin) or mTOR (200nM rapamycin). Cells were cultured for 30min and phosphorylation levels of Akt, mTOR and p70 ribosomal protein S6 kinase (p70S6K) were determined by immunoblotting. Cell proliferation and quantitative polymerase chain reaction assays were conducted using cells cultured for 24h. IGF1 increased phosphorylation of Akt, mTOR and p70S6K and cell proliferation, and these effects were inhibited by inhibitors of IGF1R, Akt and mTOR. Furthermore, IGF1 upregulated the expression of cholesterol biosynthetic genes (3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS1) and cytochrome P450, family 5, subfamily A, polypeptide 1 (CYP5A1)), but not sterol regulatory element-binding transcription factor 1 (SREBF1). Increased phosphorylation of p70S6K, a major downstream target of mTOR, and upregulated expression of genes involved in cholesterol biosynthesis are indicative of the key role played by IGF1 in regulating the synthesis of cholesterol, the precursor for steroid hormones.

scholarly journals Interaction among estrogen, IGF-1, and H2S on smooth muscle cell proliferation

2021 ◽  
Vol 248 (1) ◽  
pp. 17-30
Author(s):  
Tian Shuang ◽  
Ming Fu ◽  
Guangdong Yang ◽  
Ying Huang ◽  
Zhongming Qian ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Critical Role ◽  
Insulin Like Growth Factor ◽  
Vascular Effects ◽  
Vascular Effect ◽  
Vascular Smcs ◽  
Underlying Mechanisms

Both estrogen and hydrogen sulfide (H2S) inhibit the proliferation of vascular smooth muscle cells (SMCs) and development of atherosclerosis. In the absence of endogenous H2S as occurred in CSE-knockout (KO) mouse, however, estrogen stimulates the proliferation of vascular SMCs. The underlying mechanisms for this seemingly controversial vascular effect of estrogen are unclear. In the present study, we demonstrated that the stimulatory effect of estrogen on the proliferation of CSE-KO SMCs was suppressed by the inhibitor of insulin-like growth factor-1 receptor (IGF-1R) or knockdown of IGF-1R protein expression. Estrogen downregulated the expression of insulin-like growth factor-1 (IGF-1) and IGF-1R in aortic tissues or aortic SMCs isolated from WT and CSE-KO mice. Furthermore, endogenous H2S downregulated IGF-1R, but upregulated estrogen receptor (ER)-α, in aortic tissues or SMCs. ER-α and IGF-1R were co-located in SMCs and co-immunoprecipitated, which was decreased by H2S. Finally, both endogenous and exogenous H2S induced the S-sulfhydration of IGF-1R, but not ER-α, in WT-SMCs and CSE-KO SMCs, which underlies the decreased formation of IGF-1R/ER-α hybrid in the presence of H2S. Thus, the absence of H2S favors the interaction of estrogen with IGF-1R/ER-α hybrid to stimulate SMCs proliferation. The appreciation of a critical role of H2S in preventing estrogen-induced SMCs proliferation will help better understand the regulation of complex vascular effects of estrogen and sex-related cardiovascular diseases.

Role of mTOR1 and mTOR2 complexes in MEG-01 cell physiology

2015 ◽  
Vol 114 (11) ◽  
pp. 969-981 ◽  
Author(s):  
Esther López ◽  
Alejandro Berna-Erro ◽  
Javier J. López ◽  
María P. Granados ◽  
Nuria Bermejo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Cell Physiology ◽  
Cell Stimulation ◽  
Intracellular Location ◽  
Macromolecular Complexes

SummaryThe function of the mammalian target of rapamycin (mTOR) is upregulated in response to cell stimulation with growing and differentiating factors. Active mTOR controls cell proliferation, differentiation and death. Since mTOR associates with different proteins to form two functional macromolecular complexes, we aimed to investigate the role of the mTORI and mTOR2 complexes in MEG-01 cell physiology in response to thrombopoietin (TPO). By using mTOR antagonists and overexpressing FKBP38, we have explored the role of both mTOR complexes in proliferation, apoptosis, maturation-like mechanisms, endoplasmic reticulum-stress and the intracellular location of both active mTOR complexes during MEG-01 cell stimulation with TPO. The results demonstrate that mTOR1 and mTOR2 complexes play different roles in the physiology of MEG-01 cells and in the maturation-like mechanisms; hence, these findings might help to understand the mechanism underlying generation of platelets.

A combination of insulin-like growth factor I (IGF-I) and FSH promotes proliferation of prepubertal bovine Sertoli cells isolated and cultured in vitro

2017 ◽  
Vol 29 (8) ◽  
pp. 1635 ◽  
Author(s):  
A. Dance ◽  
J. Kastelic ◽  
J. Thundathil
Keyword(s):  
Growth Factor ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Seminiferous Tubules ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Bull Calves ◽  
Igf I ◽  
Growth Factor I

Beef and dairy bull calves fed a low-nutrition diet during early life had decreased concentrations of circulating insulin-like growth factor I (IGF-I), delayed increases in testosterone, smaller testes and delayed puberty compared with those fed high-nutrition diets. Although IGF-1 has important roles in Sertoli cell function in rats and mice, this has not been well documented in bulls. The objectives of this study were to: (1) isolate Sertoli cells from bull calves at 8 weeks of age, (2) culture them in vitro and (3) determine the effects of IGF-I, FSH and a combination of both hormones on cell proliferation. For Sertoli cell isolation, minced testicular tissues were treated with collagenase followed by trypsin and hyaluronidase to digest seminiferous tubules and release Sertoli cells. In this study, Sertoli cells were successfully isolated from 8-week-old Holstein bull calves (n = 4) and these cells were cultured for up to 8 days. A combination of IGF-I and FSH increased proliferation (~18%) and therefore cell number (1.5-fold) of prepubertal bovine Sertoli cells in culture, providing clear evidence that IGF-I has a similar role in bovine Sertoli cells as reported in rodents.

Insulin-Like Growth Factor 1/Mammalian Target of Rapamycin and AMP-Activated Protein Kinase Signaling Involved in the Effects of Metformin in the Human Endometrial Cancer

2016 ◽  
Vol 26 (9) ◽  
pp. 1667-1672 ◽  
Author(s):  
Dongge Cai ◽  
Hongli Sun ◽  
Yanhua Qi ◽  
Xiaogui Zhao ◽  
Minjuan Feng ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Growth Factor ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Pilot Trial ◽  
Plasma Concentrations ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Insulin Like Growth Factor ◽  
Amp Activated Protein Kinase

BackgroundMetformin is a well-tolerated biguanide drug used for decades to treat type 2 diabetes mellitus. In recent years, long-term administration of metformin has been found to reduce carcinogenic risk for cancers derived from various tissues. However, its cellular and molecular mechanisms of anticancer action in the endometrial cancer (EC) have not yet been fully elucidated.Patients and MethodsSixty patients diagnosed as endometrial carcinoma were grouped into (n = 30) and non-treatment mixed (n = 30) for analysis. Thirty healthy donors are control groups. We attempt to investigate the interaction of metformin, insulin-like growth factor 1 (IGF-1) expression, and phosphorylated mammalian target of rapamycin (p-mTOR) and AMP-activated protein kinase (p-AMPK).ResultsWe found that high IGF-1 plasma concentrations in women with EC were reversed by conventional antidiabetic doses of metformin in the present work. In parallel, the activation of AMPK and suppression of mTOR seemed to play an important role for the effect of metformin in patients with EC.ConclusionsThis pilot trial presents biological evidence consistent with antiproliferative effects of metformin in women with EC in the clinical setting.

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