O-158 The effect of circadian rhythm disruption due to constant light on ovarian and oocyte aging through possible relationship between PER2 and mTOR signaling pathway

Abstract Study question Does circadian rhythm disruption by constant light affect the ovarian morphology and function, and cause ovarian and oocyte aging through possible relationship between PER2 and mTOR? Summary answer We demonstrated that circadian rhythm disruption by light may cause ovarian and oocyte aging. What is known already Circadian rhythm regulates multiple physiological processes and PER2 is one of the core circadian rhythm components. Changes in light conditions may cause circadian rhythm disruptions. Light exposure at night may cause attenuation in PER2 mRNA and protein levels. Circadian rhythm disruptions are thought to be associated with reproductive diseases. mTOR signaling pathway functions in folliculogenesis and oocyte maturation in ovary. Also, it is associated with ovarian and oocyte aging. Study design, size, duration A total of 32 female Balb/c mice which enter estrous cycle were used in the study. Mice were randomly assigned to one of two groups as 12:12h L:D and 12:12h L:L. During the experiment, 12:12h L:D (control group) was housed in a 12:12h light:dark cycle and 12:12h L:L (experiment group) was housed in a constant light conditions 12:12h light:light for 1 week. Participants/materials, setting, methods We housed 12:12h L:D group in standard lightening conditions and 12:12h L:L group in constant light for one week. We performed food intake and body weight change analysis. We evaluated ovarian morphology, follicle counting analysis. We evaluated ZP3 and nitrotyrosine (NTY) expression for oocyte aging markers. We performed western blot for PER2, mTOR, p-mTOR, p70 S6K, p-p70 S6K, and Caspase-3 protein levels. Main results and the role of chance We demonstrated that circadian rhythm disruption caused alteration in their food intake and decrease in primordial follicle numbers and increase in atretic follicles (p < 0.05). It caused increase in oxidative stress and decrease in ZP3 expression in oocytes (p < 0.05). We showed decreased protein levels of PER2, mTOR, p-mTOR and p70 S6K (p < 0.05). Limitations, reasons for caution The explanation of molecular mechanism underlying the relationship between circadian rhythm disruptions by light and ovarian function may lead the usage of circadian rhythm-based or light-based therapies currently using to treat some diseases on female reproductive system related diseases. Wider implications of the findings We conclude that constant light may reduce follicle reserve, cause follicles to go rapidly atresia and disrupt the oocyte quality, thus it may be a risk factor for female reproductive diseases such as premature ovarian insufficiency and early menopause. Trial registration number not applicable

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(Pro)renin receptor regulates autophagy and apoptosis in podocytes exposed to high glucose

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00603.2014 ◽

2015 ◽

Vol 309 (3) ◽

pp. E302-E310 ◽

Cited By ~ 26

Author(s):

Caixia Li ◽

Helmy M. Siragy

Keyword(s):

Signaling Pathway ◽

High Glucose ◽

Caspase 3 ◽

Mtor Signaling ◽

Autophagic Flux ◽

Bafilomycin A1 ◽

Mtor Signaling Pathway ◽

Autophagosome Formation ◽

Podocyte Injury ◽

Protein Levels

High glucose reduces autophagy and enhances apoptosis of podocytes. Previously, we reported that high glucose induced podocyte injury through upregulation of the (pro)renin receptor (PRR). We hypothesized that increasing PRR reduces autophagy and increases apoptosis of mouse podocytes exposed to high glucose via activation of the PI3K/Akt/mTOR signaling pathway. Mouse podocytes were cultured in normal (5 mmol/l) or high (25 mmol/l) d-glucose for 48 h. High glucose significantly increased mRNA and protein levels of PRR, phosphorylation of PI3K/Akt/mTOR, and p62. In contrast, high glucose decreased activation of UNC-51-like kinase-1 (ULK1) by phosphorylating Ser757 and protein levels of microtubule-associated protein-1 light chain 3B (LC3B)-II and Lamp-2. Bafilomycin A1 increased LC3BII and p62 accumulation in high-glucose-treated cells. High glucose reduced the autophagic flux. Confocal microscopy studies showed significant reduction in the protein level of LC3B in response to high glucose. Cyto-ID autophagy staining showed a significant decrease in autophagosome formation with high glucose. In the absence of PRR, activation of Akt with sc-79 or mTOR with MHY-1485 increased p62 accumulation. Caspase-3/7 activity and apoptosis monitored by TUNEL assay were significantly increased in podocytes treated with high glucose. PRR siRNA significantly reversed the effects of high glucose. Based on these data, we conclude that high glucose decreases autophagy and increases apoptosis in mouse podocytes through the PRR/PI3K/Akt/mTOR signaling pathway.

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The Circadian Rhythm of Leaf Movement of Coleus blumei x C. frederici, a Short Day Plant. I. Under Constant Light Conditions

PLANT PHYSIOLOGY ◽

10.1104/pp.43.12.1883 ◽

1968 ◽

Vol 43 (12) ◽

pp. 1883-1886 ◽

Cited By ~ 10

Author(s):

Ruth Halaban

Keyword(s):

Circadian Rhythm ◽

Constant Light ◽

Leaf Movement ◽

Light Conditions ◽

Short Day ◽

Coleus Blumei

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SIK2 Promotes Cisplatin Resistance Induced by Aerobic Glycolysis in Breast Cancer Cells through PI3K/AKT/mTOR Signaling Pathway

10.21203/rs.2.24397/v1 ◽

2020 ◽

Author(s):

Shoukai Zong ◽

Wei Dai ◽

Wencheng Fang ◽

Xiangting Guo ◽

Kai Wang

Keyword(s):

Breast Cancer ◽

Western Blot ◽

Cancer Cells ◽

Signaling Pathway ◽

Breast Cancer Cells ◽

Cisplatin Resistance ◽

Aerobic Glycolysis ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Protein Levels

Abstract Objective This study aimed to investigate the effect of SIK2 on cisplatin resistance induced by aerobic glycolysis in breast cancer cells and its potential mechanism. Methods qRT-PCR and Western blot were used to detect SIK2 mRNA and protein levels. Cisplatin (DDP) resistant cell lines of breast cancer cells were established, CCK-8 was used to measure and evaluate the viability, and Transwell was used to evaluate the cell invasion capability. Flow cytometry was adopted to evaluate the apoptosis rate. The glycolysis level was evaluated by measuring glucose consumption and lactic acid production. The protein levels of p-PI3K, p- protein kinase B (Akt) and p-mTOR were determined by western blot. Results SIK2 is highly expressed in breast cancer tissues and cells compared with adjacent tissues and normal human breast epithelial cells, and has higher diagnostic value for breast cancer. Silencing SIK2 expression can inhibit proliferation and invasion of breast cancer cells and induce their apoptosis. In addition, SIK2 knockdown inhibits glycolysis, reverses the resistance of drug-resistant cells to cisplatin, and inhibits PI3K/AKT/mTOR signaling pathway. When LY294002 is used to inhibit PI3K/AKT/mTOR signaling pathway, the effect of Sh-SIK2 on aerobic glycolysis of breast cancer cells can be reversed. Conclusion SIK2 can promote cisplatin resistance caused by aerobic glycolysis of breast cancer cells through PI3K/AKT/mTOR signaling pathway, which may be a new target to improve cisplatin resistance of breast cancer cells.

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Tenacissoside H Induces Autophagy and Radiosensitivity of Hepatocellular Carcinoma Cells by PI3K/Akt/mTOR Signaling Pathway

Dose-Response ◽

10.1177/15593258211011023 ◽

2021 ◽

Vol 19 (2) ◽

pp. 155932582110110

Author(s):

Jiatian Lin ◽

Jiyin Ruan ◽

Hao Zhu ◽

Zaizhong Chen ◽

Junhui Chen ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Signaling Pathway ◽

Mtor Signaling ◽

Cell Counting ◽

Dependent Manner ◽

Mtor Signaling Pathway ◽

Concentration Dependent Manner ◽

Protein Levels ◽

Underlying Mechanisms ◽

Hcc Cells

Tenacissoside H (TEH), which has anti-inflammatory and anti-tumor effects, is a major active ingredient extracted from the stem of Marsdenia tenacissima. However, the effect of TEH on hepatocellular carcinoma (HCC) as well as the underlying mechanisms are still indistinct. Presently, HCC cells (including Huh-7 and HepG2) were dealt with different concentrations of TEH. The proliferation and apoptosis of HCC cells were determined via Cell Counting Kit-8 (CCK8) assay and flow cytometry. In addition, Western blot was conducted to evaluate the expressions of autophagy—and apoptosis-related proteins. Tissue immunofluorescence was carried out to evaluate LC3B expression in the tumor tissues. The data showed that TEH suppressed the growth of HCC cells in a concentration-dependent manner. Besides, TEH enhanced radiosensitivity and promoted the apoptosis of HCC cells. Moreover, the mRNA and protein levels of autophagy-related genes (LC3-II/LC2-I, ATG5, Beclin-1) were significantly promoted by TEH. Mechanistically, TEH attenuated the activation of PI3K/Akt/mTOR signaling pathway. However, inhibition of PI3 K pathway abolished the anti-tumor effects of TEH in HCC cells. Collectively, this study suggested that TEH increases the radiosensitivity of HCC cells via inducing autophagy and apoptosis through downregulating PI3K/Akt/mTOR signaling pathway.

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ID2 Inhibits Lung Adenocarcinoma Cell Malignant Behaviors Through Inhibiting the Activation of the PI3K/AKT/mTOR Signaling Pathway

10.21203/rs.3.rs-817478/v1 ◽

2021 ◽

Author(s):

Wenzhong Peng ◽

Jia Chen ◽

Ruoxi He ◽

Yongjun Tang ◽

Juan Jiang ◽

...

Keyword(s):

Lung Adenocarcinoma ◽

Candidate Gene ◽

Signaling Pathway ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Tissue Samples ◽

Adenocarcinoma Cell ◽

Protein Levels ◽

Adenocarcinoma Cells ◽

Lung Adenocarcinoma Cells

Abstract Background: Lung cancer is the most common cancer and one of the main causes of cancer-related deaths, and it manifests as metastatic disease in most cases. Considering frequent gene mutation and/or signaling deregulation in lung adenocarcinoma, identifying novel factors or agents targeting these signaling pathways might be promising strategies for lung adenocarcinoma therapy. Methods: GEO datasets were analyzed to identify differentially expressed genes (DEGs) in lung adenocarcinoma. The specific effects of candidate gene overexpression or knockdown on lung adenocarcinoma cell phenotypes were examined. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) are used to connect the genomic and functional information of DEGs. The dynamic effects of candidate gene and signaling pathway agonist on lung adenocarcinoma malignant behaviors were investigated. Finally, clinical lung adenocarcinoma and adjacent non-cancerous tissues were collected and the levels of candidate gene were examined in tissue samples.Results: Inhibitor of DNA binding 2 (ID2) was identified as an aberrantly downregulated gene in lung adenocarcinoma. ID2 overexpression suppressed lung adenocarcinoma cell viability, colony formation capacity, and migration. ID2 overexpression also reduced the protein levels of N-cadherin, MMP2, MMP9, and the phosphorylation of AKT and mTOR. The PI3K/AKT/mTOR signaling agonist exerted opposite effects on lung adenocarcinoma cells to those of ID2 overexpression, and partially reversed the effects of ID2 overexpression. In tissue samples, ID2 protein levels and mRNA expression were also downregulated compared with those in adjacent non-cancerous tissues. Conclusion: ID2 exerts its tumor-suppressive effects on lung adenocarcinoma cell malignant behaviors through inhibiting the activation of the PI3K/AKT/mTOR signaling pathway. Restoring ID2 expression in lung adenocarcinoma cells might improve the curative effect of lung adenocarcinoma therapies.

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The regulation and mechanism of a dual PI3K/mTOR signaling inhibitor in hemangioma vascular endothelial cells in vitro

10.21203/rs.3.rs-17546/v1 ◽

2020 ◽

Author(s):

wangshu liu ◽

Yang Yu ◽

Juan Li ◽

Hui Huang ◽

Hao Liu ◽

...

Keyword(s):

Endothelial Cells ◽

Signaling Pathway ◽

Vascular Endothelial Cells ◽

Mtor Signaling ◽

Control Group ◽

Dependent Manner ◽

Vascular Endothelial ◽

Mtor Signaling Pathway ◽

Protein Levels

Abstract Objective To observe the influence of the dual PI3K/mTOR inhibitor NVP-BEZ235 on proliferation and apoptosis of hemangioma cells in vitro and key molecules of the PI3K/Akt/mTOR signaling pathway.Methods Hemangioma-derived endothelial cells (HeECs) were obtained by surgical resection and cultured after the explants with the trypsin-digestion method. Fourth generation cells were cultured with serum-free medium for 24 hours. Then, the intervention group cells were added to the culture medium with 0.50 μM or 1.00 μM NVP-BEZ235. Cell proliferation was detected with CCK-8 assays, apoptosis was detected by flow cytometry, and PI3K, Akt, mTOR, and p70s6k protein levels were detected by Western blots. Then, the relationship between the phenotype of hemangioma vascular endothelial cells and the four proteins was analyzed.Results the 0.50 μM and 1.00 μM NVP-BEZ235 groups were significantly lower (0.88±0.03 and 0.59±0.05, respectively) than the control group (1.10±0.02) (P<0.01). The rate of G0/G1 phase cells in the 0.50 μM and 1.00 μM NVP-BEZ235 group were higher than the control group (P<0.01). The total rates of apoptotic cells in the 0.50 μM and 1.00 μM NVP-BEZ235 groups were higher than the control group (2.77±1.23)% (P<0.01). The PI3K pathway related protein levels in the NVP-BEZ235 group were lower than control group (P<0.01).Conclusion The PI3K/Akt/mTOR signaling pathway participates in hemangioma development. NVP-BEZ235 affected hemangioma vascular endothelial cells in vitro by regulating the PI3K/Akt/mTOR signaling pathway in a dose-dependent manner.

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Insulin Increases Sestrin 2 Content by Reducing Its Degradation through the PI3K/mTOR Signaling Pathway

International Journal of Endocrinology ◽

10.1155/2015/505849 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 10

Author(s):

Dandan Chai ◽

Guoyu Wang ◽

Ziyu Zhou ◽

Hanyan Yang ◽

Zhiwen Yu

Keyword(s):

Signaling Pathway ◽

Insulin Signaling ◽

Hepg2 Cells ◽

Metabolic Regulation ◽

Mtor Signaling ◽

Protein Synthesis Inhibitor ◽

Mtor Signaling Pathway ◽

Synthesis Inhibitor ◽

Antitumor Property ◽

Protein Levels

Sestrin (SESN) is known as a cysteine sulfinic acid reductase. Recently, nonredox functions of SESN in metabolic regulation and antitumor property have been recognized. While mechanisms underlying the expression of SESN are not fully understood. Here we report that insulin markedly increased SESN2 level in HepG2 cells through mTOR activation. To determine whether insulin affects SESN2 degradation, we assessed SESN2 turnover by applying the protein synthesis inhibitor, cycloheximide (CHX), and found that following insulin treatment SESN2 protein levels were reduced significantly slower than non-insulin-treated cells. Furthermore, the proteasomal inhibitor, MG132, dramatically increased SESN2 protein and its ubiquitination level while in the presence of MG132 insulin did not further increase SESN2 content, suggesting that insulin increases SESN2 content mainly via inhibiting its proteasomal degradation. We then explored the potential feedback role of SESN2 in insulin signaling by SESN2 siRNA knockdown in HepG2 cells. Following SESN2 knockdown insulin-stimulated PKB phosphorylation was enhanced and accompanied by reduced PTEN content. Taken together, our study suggests that insulin upregulates SESN2 content via the PI3K/mTOR signaling pathway and this effect is attributed to decreased SESN2 degradation. Furthermore, SESN2 via modulating PTEN plays a negative feedback role in insulin signaling.

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