scholarly journals Mechanical Stress-Induced IGF-1 Facilitates col-I and col-III Synthesis via the IGF-1R/AKT/mTORC1 Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bin Yan ◽  
Canjun Zeng ◽  
Yuhui Chen ◽  
Minjun Huang ◽  
Na Yao ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Signaling Pathway ◽  
Ligamentum Flavum ◽  
Neutralizing Antibody ◽  
Underlying Mechanism ◽  
Mrna Levels ◽  
Stress Exposure ◽  
Collagen Iii ◽  
Mtorc1 Signaling ◽  
The Relationship

Mechanical stress promotes human ligamentum flavum cells (LFCs) to synthesize multitype collagens, leading to ligamentum flavum hypertrophy (LFH). However, the mechanism of mechanical stress in the formation of collagen remains unclear. Therefore, we investigated the relationship between mechanical stress and collagen synthesis in the present study. First, LFCs were isolated from 9 patients and cultured with or without mechanical stress exposure for different times. IGF-1, collagen I (col-I), and collagen III (col-III) protein and mRNA levels were then detected via ELISA and qPCR, respectively. Moreover, the activation of pIGF-1R, pAKT, and pS6 was examined by Western blot analysis. To further explore the underlying mechanism, an IGF-1 neutralizing antibody, NVP-AEW541, and rapamycin were used. IGF-1, col-I, and col-III were significantly increased in stressed LFCs compared to nonstressed LFCs. In addition, the activation of pIGF-1R, pAKT, and pS6 was obviously enhanced in stressed LFCs. Interestingly, col-I protein, col-I mRNA, col-III protein, col-III mRNA, and IGF-1 protein, but not IGF-1 mRNA, were inhibited by IGF-1 neutralizing antibody. In addition, col-I and col-III protein and mRNA, but not IGF-1, were inhibited by both NVP-AEW541 and rapamycin. Moreover, the activation of pIGF-1R, pAKT, and pS6 was reduced by the IGF-1 neutralizing antibody and NVP-AEW541, and the activation of pS6 was reduced by rapamycin. In summary, these results suggested that mechanical stress promotes LFCs to produce IGF-1, which facilitates col-I and col-III synthesis via the IGF-1R/AKT/mTORC1 signaling pathway.

scholarly journals Locally Produced IGF-1 Promotes Hypertrophy of the Ligamentum Flavum via the mTORC1 Signaling Pathway

2018 ◽  
Vol 48 (1) ◽  
pp. 293-303 ◽  
Author(s):  
Bin Yan ◽  
Minjun Huang ◽  
Canjun Zeng ◽  
Na Yao ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Signaling Pathway ◽  
Ligamentum Flavum ◽  
The Elderly ◽  
Collagen I ◽  
Second Primary ◽  
High Morbidity ◽  
Collagen Iii ◽  
Mtorc1 Signaling ◽  
Lumbar Spinal

Background/Aims: Narrowing of the lumbar spinal canal is a condition called lumbar spinal stenosis (LSS) and is a high-morbidity problem in the elderly. LSS is commonly caused by hypertrophy of the ligamentum flavum (HLF). Previous studies showed that fibrosis of the ligamentum flavum (LF) largely contributed to HLF. However, the underlying pathomechanism remains unclear. Insulin-like growth factor-1 (IGF-1) is known to have an intimate relationship with fibrosis in various tissues. Nevertheless, currently, there are few studies regarding IGF-1 in HLF. In this study, we investigated the role of IGF-1 in HLF and its potential molecular mechanism of action. Methods: First, the IGF-1, phosphorylation of IGF-1 receptor (pIGF-1R), phosphorylation of AKT (pAKT), phosphorylation of S6(pS6), collagen I and collagen III expression levels were examined via immunohistochemistry and Western blotting in LF tissues from patients with LSS or Non-LSS. Second, primary LF cells were isolated from adults with a normal LF thickness and were cultured with different concentrations of IGF-1 with or without NVP-AEW541/rapamycin. Results: The results showed that IGF-1, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression in the LSS group was significantly higher than that in the Non-LSS group. Meanwhile, pIGF-1R, pAKT, pS6, collagen I and collagen III protein expression was significantly enhanced in LF cells after IGF-1 exposure, which can be notably blocked by NVP-AEW541. In addition, pS6, collagen I and collagen III protein expression was blocked by rapamycin. Conclusions: Enhanced IGF-1 promotes the synthesis of collagen I and collagen III via the mTORC1 signaling pathway, which eventually contributes to hypertrophy of the ligamentum flavum.

scholarly journals Tou Nong San Attenuates Inflammation in TNBS-IBD Model by Inhibiting NF-κB Signaling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Zhipeng Hu ◽  
Maoyi Yang ◽  
Qiaobo Ye ◽  
Kaihua Qin ◽  
Mingquan Wu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
High Performance ◽  
Chemical Constituents ◽  
Underlying Mechanism ◽  
Interleukin 17 ◽  
Rat Tissues ◽  
Mrna Levels ◽  
Trinitrobenzenesulfonic Acid ◽  
Inflammatory Bowel ◽  
Positive Effect

The incidence of inflammatory bowel disease (IBD), which predominantly comprises Crohn’s disease and ulcerative colitis, is increasing worldwide. However, the treatment of IBD still faces great challenges. The involved NF-κB is the main signaling pathway in human IBD and thus is a prime target. There is abundant evidence that Tou Nong San (TNS), which is a traditional Chinese medicinal decoction used for treating sores and carbuncles, has a positive effect on the inflammation. This study investigated the effects of oral administration of TNS on colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) and the underlying mechanism(s). Quality control of the major compounds in TNS was performed by high-performance liquid chromatography, and six chemical constituents were identified in aqueous extracts. TNS led to improvements in weight loss and water and food intake in rats. The macroscopic and microscopic scores of rat tissues greatly decreased. Protein and mRNA levels of proinflammatory cytokines, including interleukin-17 (IL-17), tumour necrosis factor-α, IL-1β, and IL6, involved in the NF-κB signaling pathway were greatly reduced. The results suggest that the anti-inflammatory effect of TNS is associated with the regulation of the NF-κB signaling pathway, which contributes to the network pharmacological effect of TNS on human IBD in clinical practice.

scholarly journals Crystal structure of arginine-bound lysosomal transporter SLC38A9 in the cytosol-open state

2018 ◽  
Author(s):  
Hsiang-Ting Lei ◽  
Jinming Ma ◽  
Silvia Sanchez Martinez ◽  
Tamir Gonen
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Signaling Pathway ◽  
Transmembrane Helix ◽  
Underlying Mechanism ◽  
Transitional State ◽  
Mechanistic Target Of Rapamycin ◽  
Mtorc1 Signaling ◽  
Solute Carrier ◽  
Amino Acid Sensing

Amino acid-dependent activation of mechanistic target of rapamycin complex 1 (mTORC1) is essential to reflect nutrient availabilities in cells for cell growth and metabolism1. Solute carrier 38 family A member 9 (SLC38A9) is the lysosomal transporter responsible for amino acid sensing in the mTORC1 signaling pathway2–4. Here we present the first crystal structure of SLC38A9 from Danio rerio in complex with arginine. As captured in the cytosol-open state, the bound arginine was locked in a transitional state stabilized by the transmembrane helix 1 (TM1) of SLC38A9 which was anchored at the grove between transmembrane helix 5 and 7 inside the transporter. The key motif WNTMM on TM1, contributing to the anchoring interactions, is highly conserved in various species. Mutations in WNTMM motif abolished arginine transport by SLC38A9. The underlying mechanism of substrate binding is critical for both sensitizing mTORC1 signaling pathway to amino acids and for maintaining amino acid homeostasis across lysosomal membranes2.

scholarly journals Luteolin Prevents H2O2-Induced Apoptosis in H9C2 Cells through Modulating Akt-P53/Mdm2 Signaling Pathway

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hong Chang ◽  
Chun Li ◽  
Kuiyuan Huo ◽  
Qiyan Wang ◽  
Linghui Lu ◽  
...  
Keyword(s):  
Cell Viability ◽  
Signaling Pathway ◽  
Underlying Mechanism ◽  
Chinese Herbs ◽  
Mrna Levels ◽  
H9c2 Cells ◽  
Apoptotic Pathway ◽  
Apoptosis Rate ◽  
Established Cell ◽  
Induced Apoptosis

Introduction.Luteolin, a falconoid compound in many Chinese herbs and formula, plays important roles in cardiovascular diseases. The underlying mechanism of luteolin remains to be further elaborated.Methods. A model of hydrogen peroxide- (H2O2-) induced H9C2 cells apoptosis was established. Cell viabilities were examined with an MTT assay.2′,7′-Dichlorofluorescin diacetate (DCFH-DA) and flow cytometry were used to detect ROS level and apoptosis rate, respectively. The expressions of signaling proteins related to apoptosis were analyzed by western blot and mRNA levels were detected by real-time polymerase chain reaction (PCR). Quercetin was applied as positive drug.Results. Incubation with various concentrations of H2O2(0, 50, 100, and 200 μM) for 1 h caused dose-dependent loss of cell viability and 100 μM H2O2reduced the cell viability to approximately 50%. Treatments with luteolin and quercetin protected cells from H2O2-induced cytotoxicity and reduced cellular ROS level and apoptosis rate. Moreover, luteolin could downregulate the expressions of Bax, caspase-8, cleaved-caspase-3, and p53 in apoptotic signaling pathway. Further study showed that the expressions of Akt, Bcl-2, and Mdm2 were upregulated by luteolin.Conclusion. Luteolin protects H9C2 cells from H2O2-induced apoptosis. The protective and antiapoptotic effects of luteolin could be mediated by regulating the Akt-P53/Mdm2 apoptotic pathway.

scholarly journals Cyclocarya paliurus Polysaccharide Inhibits Glioma Cell U251 Proliferation, Migration, and Invasion and Promotes Apoptosis via the GSK3β/β-Catenin Signaling Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaolong Du ◽  
Kai Guo ◽  
Yongqian Ma ◽  
Jianyong Chang
Keyword(s):  
Protein Expression ◽  
Signaling Pathway ◽  
Underlying Mechanism ◽  
Cell Counting ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Cyclocarya Paliurus ◽  
Protein Levels ◽  
U251 Cells

Objective. To investigate the effects of Cyclocarya paliurus polysaccharide (CPP) on the proliferation, migration, invasion, and apoptosis of human glioma U251 cells and further explore the underlying mechanism. Methods. U251 cells were cultured in vitro and treated with various concentrations (25, 50, 75, 100, 125, and 150 μmol/L) of CPP for 24, 48, and 72 h. Cell counting kit-8 was used to detect the activity of cell proliferation. Wound-healing assay, Transwell assay, and flow cytometry were used to measure the effects of CPP on the migration, invasion, and apoptosis of U251 cells, respectively. Western blotting was used to determine the protein expression involved in the GSK3β/β-catenin signaling pathway and its downstream genes related to proliferation, migration, invasion, and apoptosis including Cyr61, CCND1, Vimentin, and Slug. Meanwhile, qRT-PCR was used to detect the mRNA levels of Cyr61, CCND1, Vimentin, and Slug. Results. We found that CPP not only could inhibit the proliferation, migration, and invasion of U251 cells but also promote its apoptosis in vitro. Besides, CPP could significantly inhibit the phosphorylation and decrease the protein levels of GSK3 β at ser9 site (p<0.05), and thus increasing the phosphorylation of β-Catenin at ser33/37 site (p<0.05), resulting in β-Catenin degradation. In addition, we also found that CPP could downregulate the mRNA (p<0.05) and protein expression (p<0.05) of downstream genes of GSK3 β/β-catenin signaling pathway including Cyr61, CCND1, Vimentin, and Slug, which are related to proliferation, migration, invasion, and apoptosis. Conclusion. CPP could inhibit the expression of GSK3β, promote the degradation of β-catenin, and downregulate the levels of GSK3β/β-catenin downstream genes including Cyr61, CCND1, Vimentin, and Slug, which regulate the proliferation, migration, invasion, and apoptosis of glioma cells.

Growth performance, amino acid retention and mRNA levels of mTORC1 signaling pathway genes in Nile tilapia fingerlings fed protein-bound and crystalline amino acids

Aquaculture ◽  
2021 ◽  
pp. 736953
Author(s):  
Thaís Pereira da Cruz ◽  
Mariana Michelato ◽  
Maeli Dal-Pai-Silva ◽  
Tassiana Gutierrez de Paula ◽  
Edson Assunção Macedo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Growth Performance ◽  
Signaling Pathway ◽  
Nile Tilapia ◽  
Mrna Levels ◽  
Mtorc1 Signaling ◽  
Crystalline Amino Acids

scholarly journals mTORC1 Signaling Pathway Mediates Chronic Stress-Induced Synapse Loss in the Hippocampus

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu-Fei Luo ◽  
Xiao-Xia Ye ◽  
Ying-Zhao Fang ◽  
Meng-Die Li ◽  
Zhi-Xuan Xia ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Glutamate Receptors ◽  
Signaling Pathway ◽  
Chronic Stress ◽  
Restraint Stress ◽  
Mrna Levels ◽  
Chronic Restraint Stress ◽  
Synapse Loss ◽  
Antidepressant Effects ◽  
Mtorc1 Signaling

Background: The mechanistic target of rapamycin complex 1 (mTORC1) signaling has served as a promising target for therapeutic intervention of major depressive disorder (MDD), but the mTORC1 signaling underlying MDD has not been well elucidated. In the present study, we investigated whether mTORC1 signaling pathway mediates synapse loss induced by chronic stress in the hippocampus.Methods: Chronic restraint stress-induced depression-like behaviors were tested by behavior tests (sucrose preference test, forced swim test and tail suspension test). Synaptic proteins and alternations of phosphorylation levels of mTORC1 signaling-associated molecules were measured using Western blotting. In addition, mRNA changes of immediate early genes (IEGs) and glutamate receptors were measured by RT-PCR. Rapamycin was used to explore the role of mTORC1 signaling in the antidepressant effects of fluoxetine.Results: After successfully establishing the chronic restraint stress paradigm, we observed that the mRNA levels of some IEGs were significantly changed, indicating the activation of neurons and protein synthesis alterations. Then, there was a significant downregulation of glutamate receptors and postsynaptic density protein 95 at protein and mRNA levels. Additionally, synaptic fractionation assay revealed that chronic stress induced synapse loss in the dorsal and ventral hippocampus. Furthermore, these effects were associated with the mTORC1 signaling pathway-mediated protein synthesis, and subsequently the phosphorylation of associated downstream signaling targets was reduced after chronic stress. Finally, we found that intracerebroventricular infusion of rapamycin simulated depression-like behavior and also blocked the antidepressant effects of fluoxetine.Conclusion: Overall, our study suggests that mTORC1 signaling pathway plays a critical role in mediating synapse loss induced by chronic stress, and has part in the behavioral effects of antidepressant treatment.

MiR-493 Induces Cytotoxic Autophagy in Prostate Cancer Cells through Regulation on PHLPP2

2020 ◽  
Vol 21 (14) ◽  
pp. 1451-1456 ◽  
Author(s):  
Jun Deng ◽  
Ming Ma ◽  
Wei Jiang ◽  
Liangliang Zheng ◽  
Suping Cui
Keyword(s):  
Prostate Cancer ◽  
Protein Expression ◽  
Cell Function ◽  
Mrna Levels ◽  
Prostate Cancer Cells ◽  
Potent Inducer ◽  
Qrt Pcr ◽  
Autophagy Gene ◽  
The Relationship ◽  
Cancer Inhibition

Background: MiR-493 promotes the proliferation of prostate cancer (PC) cells by targeting PHLPP2. We aimed to explore the relationship between miR-493 and autophagy in PC. Methods: qRT-PCR and western blotting were used to determine the mRNA levels and protein expression of miR-493, PHLPP2, autophagy gene BECN1 and ATG7 in PC cells. The autophagy gene expression was determined after PC cells transfected with miR-493 precursor or PHLPP2 precursor. Corresponding changes of autophagy phenotype and PC cell function were also studied. Results: The mRNA levels and protein expression of miR-493, PHLPP2, BECN1 and ATG7 in PC cells were significantly decreased in PC cells. Overexpression of miR-493 or PHLPP2 markedly upregulated the expression levels of BECN1 and ATG7 in PC cells. Overexpression of miR-493 and PHLPP2 markedly promoted autophagy, and inhibited the invasion and cloning formation of PC cells. Conclusion: MiR-493 is a potent inducer of cytotoxic autophagy that leads to prostate cancer inhibition by regulating on PHLPP2.

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