scholarly journals GPR30 Activation by 17β-Estradiol Promotes p62 Phosphorylation and Increases Estrogen Receptor α Protein Expression by Inducing Its Release from a Complex Formed with KEAP1

2021 ◽  
Vol 11 (9) ◽  
pp. 906
Author(s):  
Chia-Lung Tsai ◽  
Chiao-Yun Lin ◽  
Angel Chao ◽  
Yun-Shien Lee ◽  
Ren-Chin Wu ◽  
...  

Estrogens can elicit rapid cellular responses via the G-protein-coupled receptor 30 (GPR30), followed by estrogen receptor α (ERα/ESR1)-mediated genomic effects. Here, we investigated whether rapid estrogen signaling via GRP30 may affect ESR1 expression, and we examined the underlying molecular mechanisms. The exposure of human endometrial cancer cells to 17β-estradiol promoted p62 phosphorylation and increased ESR1 protein expression. However, both a GPR30 antagonist and GPR30 silencing abrogated this phenomenon. GPR30 activation by 17β-estradiol elicited the SRC/EGFR/PI3K/Akt/mTOR signaling pathway. Intriguingly, unphosphorylated p62 and ESR1 were found to form an intracellular complex with the substrate adaptor protein KEAP1. Upon phosphorylation, p62 promoted ESR1 release from the complex, to increase its protein expression. Given the critical role played by p62 in autophagy, we also examined how this process affected ESR1 expression. The activation of autophagy by everolimus decreased ESR1 by promoting p62 degradation, whereas autophagy inhibition with chloroquine increased ESR1 expression. The treatment of female C57BL/6 mice with the autophagy inhibitor hydroxychloroquine—which promotes p62 expression—increased both phosphorylated p62 and ESR1 expression in uterine epithelial cells. Collectively, our results indicate that 17β-estradiol-mediated GPR30 activation elicits the SRC/EGFR/PI3K/Akt/mTOR signaling pathway and promotes p62 phosphorylation. In turn, phosphorylated p62 increased ESR1 expression by inducing its release from complexes that included KEAP1. Our findings may lead to novel pharmacological strategies aimed at decreasing ESR1 expression in estrogen-sensitive cells.

2021 ◽  
Author(s):  
Huanfang Fan ◽  
Dehui Li ◽  
Na Guo ◽  
Chunxia Sun ◽  
Jingfei Dong ◽  
...  

Abstract Objective. To study the inhibitory effect of Xihuang Pill on the development of DMBA combined estrogen and progesterone induced breast precancerous lesions rats by PI3K/AKT/mTOR signaling pathway, and to explore the effect of Xihuang Pill in preventing and treating breast cancer. Method. Establishment of a rat model of breast precancerous lesion with DMBA combined estrogen and progesterone sequential induction for 10 weeks. Xihuang Pill was administered by gavage continuously for 4 weeks. Take rat breast tissue and stain with hematoxylin- eosin (HE). The pathomorphological changes were observed with light microscope; TUNEL staining to detect cell apoptosis in breast tissue; Western blot was used to detect the protein expression of P-PI3K, P-AKT (S473), P-AKT (T308), PTEN, P-Tuberin/TSC2, P-Tuberin (p-S939), p-mTOR, P-4E-BP1 in breast tissues. The qRT-PCR was used to detect the gene expression of PTEN mRNA and VEGF mRNA. Immunohistochemistry was used to detect the protein expression of P-S6, p-p70s6k and VEGF. Result. Compared with the disease model group, the low, middle and high dose Xihuang Pill groups could significantly reduce the degree of breast pathology, and the number of apoptosis of breast precancerous lesions cells increased with the increase of Xihuang Pill dose; The expression levels of P-PI3K, P-AKT (S473), P-AKT (T308), p-mTOR, P-4E-BP1, p-S6, p-p70S6K, VEGF protein and VEGF mRNA dropped with the increase of Xihuang Pill dose. The expression levels of PTEN, P-Tuberin/TSC2, P-Tuberin (p-S939) protein and PTEN mRNA elevated with the increase of Xihuang Pill dose. Conclusion. Xihuang Pill can promote the apoptosis of breast precancerous lesion cells and reduce the proliferation of vascular endothelial cells, and then inhibit the progression of breast precancerous lesions. Its mechanism probably associated with the regulation of PI3K/AKT/mTOR pathway related gene protein expression.


2020 ◽  
Author(s):  
yutao guan ◽  
Fu-bin Zhang ◽  
Yan-qing Huang ◽  
Ling-ling Zhou ◽  
Wei-feng Li ◽  
...  

Abstract Background: Endometriosis is a progressive and benign disease characterized by the presence of endometrial glands and stroma tissue outside of the uterine cavity. Though endometriosis is a benign disease, it has the characteristics of malignant tumour growth. Abnormal expression of T-cadherin is involved in the occurrence and progression of many tumours. We aimed to investigate whether T-cadherin promotes the migration and invasion of endometriosis cells through the PI3K/AKT/mTOR signaling pathway. Methods: Ectopic and eutopic endometrial samples from 62 female patients with endometriosis and endometrial samples from 51 female patients without endometriosis were collected. The immortalized endometrial stromal cell line hEM15A was cultured. Real-time RT-PCR, immunohistochemistry and Western blot were used to detect the expression of T-cadherin, phospho-PI3K/Akt/mTOR and matrix metalloproteinase 2 (MMP-2). Transfection technology was employed to upregulate T-cadherin expression. The migration and invasion abilities of hEM15A cells were measured by the transwell assay with uncoated or Matrigel-coated membranes. Results: The mRNA and protein expression of T-cadherin was significantly decresed in the ectopic tissues of the patients with endometriosis, while the mRNA and protein expression in the eutopic endometrial tissues of the same patients did not significantly differ from that in the patients without endometriosis. The migration and invasion ability and phospho-PI3K/Akt/mTOR and MMP-2 expression levels were decreased in hEM15A cells with high T-cadherin expression compared with the corresponding parameters in the normal control group. However, everolimus and BEZ235 inhibited cell migration and invasion in cells with low T-cadherin expression, and weakened overexpression of T‑cadherin significantly attenuated MMP-2 protein expression. Conclusion: Loss of T-cadherin promotes cell migration and invasion in endometriosis via the PI3K/AKT/mTOR signalling pathway.


2021 ◽  
Author(s):  
De-hui Li ◽  
Huan-fang Fan ◽  
Na Guo ◽  
Chun-xia Sun ◽  
Jing-fei Dong ◽  
...  

Abstract Background:To study the inhibitory effect of Xihuang pill on the development of DMBA combined with oestrogen- and progesterone-induced breast precancerous lesions in rats by the PI3K/AKT/mTOR signaling pathway and to explore the effect of Xihuang pill in preventing and treating breast cancer. Method: Establishment of a rat model of precancerous breast lesions with DMBA combined with oestrogen and progesterone sequential induction for 10 weeks. Xihuang pill was administered continuously by gavage for 4 weeks. Rat breast tissue was stained with haematoxylin-eosin (HE). The pathomorphological changes were observed with a light microscope. TUNEL staining was used to detect cell apoptosis in breast tissue. Western blotting was used to detect the protein expression of P-PI3K, P-AKT (S473), P-AKT (T308), PTEN, P-tuberin/TSC2, P-tuberin (p-S939), p-mTOR, and P-4E-BP1 in breast tissues. qRT-PCR was used to detect the gene expression of PTEN mRNA and VEGF mRNA. Immunohistochemistry was used to detect the protein expression of P-S6, p-p70s6k and VEGF.Result:Compared with the disease model group, the low-, middle- and high-dose Xihuang pill groups could significantly reduce the degree of breast pathology, and the number of apoptotic precancerous breast lesion cells increased with increasing Xihuang pill dose. The expression levels of P-PI3K, P-AKT (S473), P-AKT (T308), p-mTOR, P-4E-BP1, p-S6, p-p70S6K, VEGF protein and VEGF mRNA dropped with increasing Xihuang pill dose. The expression levels of PTEN, P-tuberin/TSC2, P-tuberin (p-S939) protein and PTEN mRNA increased with increasing Xihuang pill dose. Conclusion:Xihuang pill can promote the apoptosis of precancerous breast lesion cells, reduce the proliferation of vascular endothelial cells, and then inhibit the progression of precancerous breast lesions. Its mechanism is probably associated with the regulation of the PI3K/AKT/mTOR pathway related protein expression.


2019 ◽  
Vol 17 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Han-Qing Liu ◽  
Ya-Wen An ◽  
A-Zhen Hu ◽  
Ming-Hua Li ◽  
Jue-Lian Wu ◽  
...  

AbstractThis study aimed to reveal potential roles of the phosphatidylinositol 3 kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway in apoptosis and autophagy of astrocytes induced by methamphetamine (METH). A Cell Counting Kit-8 (CCK-8) was used to determine the reduction in proliferation of U-118 MG cells induced by METH. Hoechst 33258 and flow cytometry were used to observe the astrocytes. Western blot analysis was performed to evaluate protein expression and phosphorylation levels. METH inhibited the proliferation of U-118 MG cells and induced apoptosis and autophagy. Western blot analysis showed that the ratio of LC3-II/I was increased, whereas the expression of Bcl-2 was decreased. The phosphorylation cascade of kinases in the PI3K-Akt-mTOR signaling pathway was significantly inhibited by METH exposure, as were proteins downstream of mTORC1, such as p70s6k, rps6, 4EBP1 and eIF4E. METH inhibited proliferation of U-118 MG cells and induced apoptosis and autophagy. The PI3K-Akt-mTOR signaling pathway likely plays a critical role in these effects.


2021 ◽  
Vol 11 ◽  
Author(s):  
Runhong Mei ◽  
Peng Lou ◽  
Guanchao You ◽  
Tianlong Jiang ◽  
Xuefeng Yu ◽  
...  

Increasing evidence reveals that estrogen, especially 17β-estradiol (17β-E2), is associated with articular cartilage metabolism disorder and postmenopausal osteoarthritis (OA). SIRT1, AMPK, and mTOR are regarded as critical mitophagy regulators. Recent studies have shown that mitophagy displays a protective effect against OA, but the molecular mechanism is not well known. This study aimed to investigate the effect of 17β-E2 on Sirtuin-1 (SIRT1) expression and the induction of mitophagy upregulation by 17β-E2 via the SIRT1-mediated AMP-activated protein kinase (AMPK)/mammalian target of the rapamycin (mTOR) signaling pathway to protect chondrocytes. ATDC5 chondrocytes were treated with different concentrations of 17β-E2 (0 M, 1 × 10-9 M, 1 × 10-8 M, and 1 × 10-7 M) for 24 h or pretreatment with or without NAM (SIRT1 inhibitor), Compound C (AMPK inhibitor) and S1842 (mTOR inhibitor) for 30 min prior to treatment with 17β-E2 (1 × 10-7 M) for 24 in each groups. Expression of SIRT1 was evaluated by real-time PCR, Western blotting and confocal immunofluorescence staining. Then, the mitophagosomes in cells were observed under a transmission electron microscopy (TEM), and the AMPK/mTOR signaling pathway was detected by Western blotting. The mitophagy-related proteins, p-AMPK, p-mTOR, p-JNK, and p-p38 were also identified by Western blot analysis. The chondrocytes viability and proliferation were determined by MTT and 5-Bromo-2’-deoxyuridine (BrdU) assay. These experiments were independently repeated 3 times The study found that 17β-E2 increased the expression level of SIRT1, p-AMPK, and mitophagy-related proteins but decreased p-mTOR expression, and then induced mitophagy upregulation in chondrocytes. More mitochondrial autophagosomes were observed in 17β-E2-treated chondrocytes under a transmission electron microscope. Also, 17β-E2 improved cell viability and proliferation with the higher expression of SIRT1 and activation of the AMPK/mTOR signaling pathway. However, SIRT1 inhibitor nicotinamide (NAM) and AMPK inhibitor Compound C blocked the beneficial effect of 17β-E2. In summary, this study was novel in demonstrating that 17β-E2 induced mitophagy upregulation to protect chondrocytes via the SIRT1-mediated AMPK/mTOR signaling pathway.


2021 ◽  
Author(s):  
Ji Zhang ◽  
Yi Hu ◽  
Huiping Huang ◽  
Qun Liu ◽  
Yang Du ◽  
...  

Abstract Fibroblast-to-myofibroblast transdifferentiation and myofibroblast hyperproliferation play a major role in Idiopathic pulmonary fibrosis (IPF). It was also reported that mTOR signaling pathway and SIRT6 have a critical role in pulmonary fibrosis. However, the mechanisms whether mTOR signaling pathway and SIRT6 affect the myofibroblasts differentiation in IPF remain unclear. The results show that SIRT6 is significantly upregulated by TGF-β1 with a time and concentration-dependent manner in MRC5 line and primary lung fibroblasts isolated from IPF patients. SIRT6 protein is also increased in IPF fibrotic lung tissues and bleomycin-challenged mice lung tissues. Also, the activity of mTOR signaling is activated in MRC5 and primary lung fibroblasts. Furthermore, the inhibitor of mTOR, rapamycin treatment significantly suppress mTORC1 pathway activity and SIRT6 protein expression. SIRT6 siRNA failed to mediate the activity of mTORC1 pathway and autophagy induction. Finally, deficiency of SIRT6 could promote TGF-β1 induced pro-fibrotic cytokines. In summary, the study have suggested that SIRT6 is a downstream of mTORC1 signaling pathway in the pulmonary fibrosis caused by TGF-β1-induced. Deficiency of SIRT6 mediated myofibroblasts differentiation through induced pro-fibrotic cytokines production but not induced-autophagy. It was indicated that manipulations of SIRT6 expression may provide a new therapeutic strategy to reverse the progression of pulmonary fibrosis.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9261 ◽  
Author(s):  
Demin Fan ◽  
Qiang Liu ◽  
Fei Wu ◽  
Na Liu ◽  
Hongyi Qu ◽  
...  

Background Renal cell carcinoma (RCC) is a fatal disease, in which the PI3K/AKT/mTOR signaling pathway serves an important role in the tumorigenesis. Previous studies have reported the prognostic significance of PI3K/AKT/mTOR signaling pathway members in RCC; however, there is insufficient evidence to date to confirm this. Thus, the present study aimed to systematically investigate the prognostic roles of multiple PI3K/AKT/mTOR signaling proteins in clear cell RCC (ccRCC) using online large-scale databases. Methods The mRNA expression profiles of PI3K/AKT/mTOR signaling pathway proteins PTEN, PIK3CA, PIK3CB, PIK3CD, PIK3CG, AKT1, AKT2, AKT3 and mTOR were investigated using the Gene Expression Profiling Interactive Analysis (GEPIA) and Oncomine databases, and the protein expression levels of PI3K, AKT and mTOR were detected using western blotting (WB) analysis. In addition, the correlation between mRNA or protein expression levels and the prognostic significance was analyzed using the Kaplan-Meier (K-M) plotter (n = 530), the Human Protein Atlas (HPA; n = 528) and The Cancer Protein Atlas (TCPA; n = 445) databases. Results The GEPIA revealed that the mRNA expression of major PI3K/AKT/mTOR pathway members, including PTEN, PIK3CA, PIK3CB, AKT1, AKT2 and AKT3, were negatively correlated with ccRCC stages (P < 0.05), though most of their mRNA and protein expression levels were notsignificantly different between ccRCC and normal tissues using GEPIA, Oncomine and WB analyses (P < 0.05). Meanwhile, using the K-M plotter and HPA prognostic analysis, it was found that the mRNA expression levels of the majority of the PI3K/AKT/mTOR signaling pathway members, including PTEN, PIK3CA, PIK3CB, PIK3CG, AKT3 and mTOR were positively correlated with overall survival (OS), whereas PIK3CD mRNA expression was negatively correlated with OS (P < 0.05). Furthermore, TCPA prognostic analysis observed that several of the key molecules of the PI3K/AKT/mTOR signaling pathway [PTEN, p-AKT (S473) and p-mTOR (S2448)] were also positively correlated with OS in patients with ccRCC (P < 0.05). In conclusion, the present study suggested that several members of the PI3K/AKT/mTOR signaling pathway, especially PTEN, may be favorable prognostic factors in ccRCC, which indicated that the PI3K/AKT/mTOR signaling pathway may be implicated in ccRCC initiation and progression.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Yanli Wang ◽  
Sijun Diao ◽  
Maoqing Hu ◽  
Lin Zhang

The Tsc1-mTOR signaling pathway is often related to obesity, and epigenetic modification may lead to expression changes of obesity-related gene. Therefore, we aim to investigate the methylation of the Tsc1-mTOR signaling pathway in regulation of obesity susceptibility. Wistar rats were fed a normal diet or a high-fat diet to develop animal models. Protein and mRNA expression levels of Tsc1-mTOR signaling in the hypothalamus were determined by Western blot and quantitative real-time PCR. Methylation of Tsc1 gene promoter was detected by bisulfite genomic sequence. Both mRNA and protein expression levels of Tsc1 in DIO group hypothalamus were lower; mTOR and its downstream targets S6K1, 4EBP1, and S6 protein expression levels were higher than those of the DIO-R group and the chow group. The Tsc1 gene promoter methylation rate in the hypothalamus was 92.05 ± 3.07 % in the DIO group, 87.27 ± 1.91 % in the DIO-R group, and 88.18 % ± 3.20 % in the chow group, respectively, with significantly higher levels in the DIO group. Both the expression levels of Tsc1 gene promoter methylation and Tsc1-mTOR signaling pathway in the hypothalamus of DIO rats and DIO-R rats are different. These findings may shed light on the potential mechanism for the differentiation of obesity susceptibility.


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