Mechanisms of OCT4 on 3,5,3'-tri-iodothyronine and FSH-induced granulosa cell development in female mice

Endocrinology ◽  
2021 ◽  
Author(s):  
Qiaozhi Wang ◽  
Yilin Yao ◽  
Xiaoshu Ma ◽  
Baoqiang Fu ◽  
Ningxin Li ◽  
...  

Abstract Octamer-binding transcription factor 4 (OCT4) regulates the pluripotency of stem cells and also plays important roles in granulosa cells growth, which is regulated by follicle-stimulating hormone (FSH). Thyroid hormone (TH) is important for the development and maturation of follicles and the maintenance of various endocrine functions. Although 3,5,3′-triiodothyronine (T3) enhances the effects of FSH on the regulation of the growth of granulosa cells and development of follicles, it is unclear whether and how TH combines with FSH to regulate OCT4 expression in granulosa cells during the preantral to early antral transition stage. Our results showed that T3 enhanced FSH-induced OCT4 expression. However, T3/FSH-induced cellular growth was reduced by OCT4 siRNA. OCT4 knockdown significantly increased the number of apoptotic cell. Moreover, T3 combined with FSH to increase ERβ expression, but did not significantly affect ERα expression. ERβ knockdown dramatically decreased T3/FSH-induced OCT4 expression and cell development and increased cell apoptosis. The PI3K/Akt pathway was involved in hormones inducing OCT4 and ERβ expressions. Furthermore, the hormones regulating OCT4 and ERβ expressions were regulated by cytochrome P450 lanosterol 14a-demethylase (CYP51), a key enzyme in sterol and steroid biosynthesis. T3 and FSH cotreatment potentiated cellular development by upregulating OCT4 expression, which is mediated by CYP51 and ERβ. These regulatory processes are mediated by the PI3K/Akt signaling pathway. These findings suggest that OCT4 mediates the T3 and FSH-induced development of follicles.

2016 ◽  
Vol 76 (10) ◽  
Author(s):  
S Heublein ◽  
S Hecht ◽  
V Nick ◽  
S Mahner ◽  
C Thaler ◽  
...  

Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 73-80 ◽  
Author(s):  
JongYeob Choi ◽  
MinWha Jo ◽  
EunYoung Lee ◽  
DooSeok Choi

In this study, we examined whether granulosa cell autophagy during follicular development and atresia was regulated by the class I phosphoinositide-3 kinase/protein kinase B (AKT) pathway, which is known to control the activity of mammalian target of rapamycin (mTOR), a major negative regulator of autophagy. Ovaries and granulosa cells were obtained using an established gonadotropin-primed immature rat model that induces follicular development and atresia. Autophagy was evaluated by measuring the expression level of microtubule-associated protein light chain 3-II (LC3-II) using western blots and immunohistochemistry. The activity of AKT and mTOR was also examined by observing the phosphorylation of AKT and ribosomal protein S6 kinase (S6K) respectively. After gonadotropin injection, LC3-II expression was suppressed and phosphorylation of AKT and S6K increased in rat granulosa cells. By contrast, gonadotropin withdrawal by metabolic clearance promoted LC3-II expression and decreased phosphorylation of AKT and S6K. In addition,in-vitroFSH treatment of rat granulosa cells also indicated inhibition of LC3-II expression accompanied by a marked increase in phosphorylation of AKT and S6K. Inhibition of AKT phosphorylation using AKT inhibitor VIII suppressed FSH-mediated phosphorylation of S6K, followed by an increase in LC3-II expression. Furthermore, co-treatment with FSH and AKT inhibitor increased the levels of apoptosis and cell death of granulosa cells compared with the single treatment with FSH. Taken together, our findings indicated that AKT-mediated activation of mTOR suppresses granulosa cell autophagy during follicular development and is involved in the regulation of apoptotic cell death.


2011 ◽  
Vol 95 (4) ◽  
pp. 1482-1486 ◽  
Author(s):  
JongYeob Choi ◽  
MinWha Jo ◽  
EunYoung Lee ◽  
DooSeok Choi

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Hong An ◽  
Joshua Wright ◽  
Yunxia Duan ◽  
Di Wu ◽  
Xunming Ji ◽  
...  

Introduction: Hypothermia is an effective neuroprotectant against stroke, but its application is limited by delayed onset, prolonged duration, and significant complications. Mild hypothermia is more clinically practical but offers weaker neuroprotection. This study investigated whether the neuroprotective effects of mild hypothermia can be enhanced by phenothiazine neuroleptics (chlorpromazine and promethazine), which were reported to have depressive or hibernation-like roles on the CNS. We also worked to elucidate the role of the PI3K/Akt signaling pathway in this protective mechanism. Methods: A total of 131 adult male Sprague-Dawley rats were randomly divided into 6 groups: sham, stroke without treatment (2-hour right middle cerebral artery occlusion), and 4 treatment groups with 1) mild hypothermia (anal temperature 33-35 0 C), 2) phenothiazines (1mg/kg chlorpromazine & 1mg/kg promethazine, anal temperature 37.8-38.3 0 C), 3) combination of mild hypothermia and phenothiazines, and 4) both therapies with the addition of a p-Akt antagonist (LY294002 was injected into the lateral ventricle 30 minutes before ischemia). Infarct volume, neurological deficit, and apoptotic cell death were determined 24h post reperfusion. Expression of p-Akt, cleaved Caspase-3, pro-apoptotic (AIF & Bax) and anti-apoptotic proteins (Bcl-2 & Bcl-xL) was assessed by Western blot at 6h and 24h after reperfusion. Results: The combination of hypothermia and phenothiazines decreased (P<0.01) infarct volume and neurological deficit. This change was associated with a reduction (P<0.01) of apoptotic cell death. Each treatment alone did not induce significant neuroprotection. The combination therapy, but not each alone, promoted (P<0.01) the expression of p-Akt, accompanied with increased expression of anti-apoptotic proteins and decreased expression of pro-apoptotic proteins. The neuroprotective effects were blocked by p-Akt inhibition. Conclusion: Mild hypothermia-induced neuroprotection was enhanced by phenothiazines in an experimental ischemia/reperfusion injury model. This study supports the involvement of the PI3K/Akt signaling pathway. This novel therapeutic strategy could be developed as an effective treatment for acute ischemic stroke.


Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 383-393 ◽  
Author(s):  
David J. Izon ◽  
Sofia Rozenfeld ◽  
Stephen T. Fong ◽  
László Kömüves ◽  
Corey Largman ◽  
...  

Abstract Hox homeobox genes play a crucial role in specifying the embryonic body pattern. However, a role for Hox genes in T-cell development has not been explored. The Hoxa-9 gene is expressed in normal adult and fetal thymuses. Fetal thymuses of mice homozygous for an interruption of the Hoxa-9 gene are one eighth normal size and have a 25-fold decrease in the number of primitive thymocytes expressing the interleukin-2 receptor (IL-2R, CD25). Progression to the double positive (CD4+CD8+) stage is dramatically retarded in fetal thymic organ cultures. This aberrant development is associated with decreased amounts of intracellular CD3 and T-cell receptor β (TCRβ) and reduced surface expression of IL-7R and E-cadherin. Mutant thymocytes show a significant increase in apoptotic cell death and premature downregulation of bcl-2 expression. A similar phenotype is seen in primitive thymocytes from adult Hoxa-9−/− mice and from mice transplanted with Hoxa-9−/−marrow. Hoxa-9 appears to play a previously unsuspected role in T-cell ontogeny by modulating cell survival of early thymocytes and by regulating their subsequent differentiation.


Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2037-2044 ◽  
Author(s):  
John J. Peluso ◽  
Xiufang Liu ◽  
Jonathan Romak

The present studies were designed to 1) describe changes in both the mitochondrial membrane potential and ATP content of spontaneously immortalized granulosa cells as they undergo apoptosis, 2) identify some of the downstream events that are activated by progesterone (P4), and 3) relate these downstream events to changes in mitochondrial function and apoptotic cell death. These studies revealed that in response to serum deprivation, the mitochondrial membrane potential initially hyperpolarizes and ATP content increases. That this increase in ATP is required for apoptosis was demonstrated by the finding that oligomycin inhibited the increase in ATP and apoptosis. Piridoxalphosphate-6-azopeyl-2′-4′-disulfonic acid, an inhibitor of purinergic receptors, which are activated by ATP, also inhibited apoptosis due to serum withdrawal. This study provides additional support for ATP’s causative role in apoptosis. Moreover, 8-Br-cGMP, a protein kinase G (PKG) activator, mimicked P4’s action, whereas a PKG antagonist, DT-3, attenuated P4’s suppressive effect on ATP and apoptosis. Finally, DT-3 treatment was shown to attenuate P4-regulated phosphorylation of 14-3-3σ and its binding partner, ATP synthaseβ/precursor and the amount of ATP synthaseβ/precursor that bound to 14-3-3σ. Based on these data, it is proposed that P4 prevents apoptosis in part by activating PKG, which in turn maintains the interaction between ATP synthaseβ/precursor and 14-3-3σ. In the absence of P4-induced PKG activity, we further propose that some ATP synthaseβ precursor dissociates from 14-3-3σ, resulting in its activation and incorporation into the ATP synthase complex, which ultimately results in an increase in ATP and apoptosis.


2016 ◽  
Vol 28 (12) ◽  
pp. 2027 ◽  
Author(s):  
Guruprasad Kalthur ◽  
Sujith Raj Salian ◽  
Ramya Nair ◽  
Jemey Mathew ◽  
Satish Kumar Adiga ◽  
...  

The aim of the present study was to determine the effects of repeated superovulation on oocyte quality and embryo developmental potential. Female Swiss albino mice were injected with 5 IU pregnant mare’s serum gonadotropin followed 48 h by 10 IU human chorionic gonadotropin. Mice were superovulated up to four times with a gap of 7 days between each superovulation cycle. Ovarian weight increased significantly with an increasing number of superovulation cycles. Although the first stimulation cycle resulted in a threefold increase in the number of oocytes, the number of oocytes decreased gradually after subsequent stimulations. Increased cytoplasmic fragmentation, abnormal mitochondrial distribution, aggregation of Golgi apparatus, spindle damage, increased intracellular oxidative stress and a decrease in expression of octamer-binding transcription factor 4 (Oct4) expression were observed in these oocytes. Further, embryos derived from mice subjected to multiple stimulation cycles exhibited a low blastocyst rate, decreased hatching rate and increased apoptosis in blastocysts. In conclusion, the present study demonstrates that repeated superovulation adversely affects mouse oocyte quality by altering the distribution of cytoplasmic organelles, increasing oxidative stress and decreasing Oct4 expression, resulting in poor developmental potential of the embryos.


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