scholarly journals The Expression and Significance of mTORC1 in Diabetic Retinopathy

2019 ◽  
Author(s):  
Yanli Liu ◽  
Yarong Zheng ◽  
Yekai Zhou ◽  
Yi Liu ◽  
Mengjuan Xie ◽  
...  

Abstract Background: To investigate the expression and significance of mechanistic target of rapamycin complex 1(mTORC1) in diabetic retinopathy(DR), and to find new targets and new methods for the treatment of DR.Methods: A DR rat model was prepared by general feeding combined with intraperitoneal injection of 10% streptozotocin (60 mg/kg). The rats were randomly divided into a control group (NDM group) and diabetes group (DM group).Three months later,the degrees of retinopathy were determined using hematoxylin and eosin staining,and the levels of p-S6, VEGF, and PEDF proteins were detected by immunohistochemistry and western blotting. Human retinal capillary endothelial cells (HRCECs) were cultured in high glucose conditions,then treated with rapamycin or transfected with siTSC1.The protein levels of p-S6 were assessed by western blotting. The 5-ethynyl-2´-deoxyuridine assay was used to detect cell proliferation, and the Transwell assay was used to detect cell migration.Results: A DM rat model was successfully developed. The expressions of p-S6 and VEGF proteins were significantly increased in the DM group (p < 0.05), and the expression of PEDF protein was significantly decreased compared with the control group (p < 0.05). In vitro,the p-S6 protein in high glucose(HG) induced HRCECs was increased compared with the normal control (p < 0.05), and cell proliferation and migration were increased compared with the normal glucose(NG) group (p < 0.05). After transfection with siTSC1 to activate mTORC1,the expression of p-S6 was increased,as well as cell proliferation and migration.In contrast rapamycin decreased p-S6 expression in HG induced HRCECs, as well as decrased proliferation and migration (p < 0.05).Conclusion: The mTORC1 played an important role in DR. After activation, mTORC1 induced expression of the p-S6 protein, regulated the expressions of VEGF and PEDF proteins, and changed the proliferation and migration of endothelial cells.The mTORC1 can therefore be used as a new target,as well as in the treatment of DR.

2020 ◽  
Author(s):  
Yanli Liu ◽  
Yarong Zheng ◽  
Yekai Zhou ◽  
Yi Liu ◽  
Mengjuan Xie ◽  
...  

Abstract Background: To investigate the expression and significance of mechanistic target of rapamycin complex 1(mTORC1) in diabetic retinopathy(DR), and to find new targets and new methods for the treatment of DR. Methods: A DR rat model was prepared by general feeding combined with intraperitoneal injection of 10% streptozotocin (60 mg/kg). The rats were randomly divided into a control group (NDM group) and a diabetes group (DM group). Three months later, the degrees of retinopathy was determined using hematoxylin and eosin staining, and the levels of p-S6, VEGF, and PEDF proteins were detected by immunohistochemistry and western blotting. Human retinal capillary endothelial cells (HRCECs) were cultured in high glucose(HG) conditions, then treated with rapamycin or transfected with siTSC1.The protein levels of p-S6 were assessed by western blotting. The 5-ethynyl-2´-deoxyuridine assay was used to detect cell proliferation, and the Transwell assay was used to detect cell migration. Results: A DM rat model was successfully developed. The expressions of p-S6 and VEGF proteins were significantly increased in the DM group (p < 0.05), and the expression of PEDF protein was significantly decreased compared with the NDM group (p < 0.05). In vitro, the p-S6 protein, as well as cell proliferation and migration, in HG induced HRCECs were increased (p < 0.05) compared with the control (normal glucose) group (p < 0.05). After transfection with siTSC1 to activate mTORC1, the expression of p-S6, as well as cell proliferation and migration, were increased. In contrast, rapamycin decreased p-S6 expression, as well as proliferation and migration, in HG induced HRCECs compared to the control group (p < 0.05). Conclusion: mTORC1 plays an important role in DR. After activation, mTORC1 induced expression of the p-S6 protein, regulated the expressions of VEGF and PEDF proteins, and changed the proliferation and migration of endothelial cells. The mTORC1 can therefore be used as a new target,as well as in the treatment of DR.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
He Hu ◽  
Shanshan Li ◽  
Jianqiao Li ◽  
Chao Huang ◽  
Fang Zhou ◽  
...  

Purpose. Recent research has provided novel insight into the function of fibromodulin (FMOD) in wound healing and angiogenesis. The role of FMOD in initiation of proliferative vitreoretinopathy (PVR) has not been studied. This study investigated the effect of FMOD on human retinal pigment epithelial (RPE) cell, which plays an essential role in the progression of PVR, and the possible mechanisms. Methods. Small interfering (si) RNA-based gene transfer technology was used to decrease FMOD expression and to study its effects on RPEs in vitro. Cell Counting Kit-8 assays, transwells, and flow cytometry analysis were used to measure cell proliferation, migration, cell cycle, and apoptosis. Western blot was used to measure expression of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR2), extracellular signal-related kinase 1/2 (ERK1/2), and phosphoinositide 3 kinase (PI3K/AKT). Results. After transfection of RPEs with a FMOD-specific siRNA, cell proliferation and migration were inhibited to the percentage of 65% ± 5% and 39% ± 10%, respectively, compared to the control group. Depletion of FMOD induced cell cycle arrest and apoptosis in RPE cells. Downregulation of VEGF, VEGFR2, and phosphorylated AKT (p-AKT) were detected in transfected RPEs. Conclusion. Depletion of FMOD selectively downregulated the expression of VEGF and VEGFR2 and inhibited the signaling pathway of AKT phosphorylation, which consequently inhibited the proliferation and migration of RPE Cell.


2021 ◽  
Author(s):  
Yanwei Li ◽  
Wei Cui ◽  
Bing Song ◽  
Xuying Ye ◽  
Zhuqing Li ◽  
...  

Abstract Background and purpose: SIRT1 exerted its link to CAS risk in humans and EPCs presented its reparative role in CAS. In this study, we explored the role of SIRT1 in CAS mice and also its modulation in EPCs.Methods and materials: ApoE-/- mice were fed with high-fat and high-glucose food to establish the CAS animal model with the normally-raised C57BL/6 mice as a healthy control group. 5 ApoE mice were intravenously injected with SIRT1 activator, SRT 2104 and another 5 were injected with inhibitor Nicotinamide in tail. Weight changes were recorded per week. Blood samples were taken from posterior orbital venous plexus and detected by automatic biochemical analyzer for lipid concentrations. Coronary artery tissues were observed. HE staining displayed the pathological condition while Immunohistochemistry (IHC) evaluated the CD34+/VEGFR2+ relative density. In vitro, EPCs were isolated from bone marrow each group and then purified, cultured and verified using immunofluorescence staining (IFS). Thereafter, we examined the modulatory mechanism of SIRT1 in EPCs by RT-PCR, MTT, Western Blot (WB) and colony formation, scratch methods, connecting the wnt/β-catenin/GSK3β signaling pathway.Results:SIRT1 activation negatively regulated the weight and TC, TG and LDL. SIRT1 activator alleviated the lesion area and decreased the CD34+/VEGFR2+ density which was higher in coronary artery tissues in CAS and SIRT1 inhibitor groups. In vitro, SIRT1 activator promoted the bone marrow-derived EPCs proliferation, migration and activated wnt/β-catenin/GSK3β signaling pathway while inhibited the autophagy biomarkers ATG1 and LC3II. Furthermore, inhibition of autophagy led to the upregulation of SIRT1 and increase in cell proliferation, migration and wnt/β-catenin/GSK3β activity. The suppression of the pathway in turn lowered SIRT1 expression in EPCs, attenuated the cell proliferation and migration and promoted autophagy. Conclusion: Taken all the findings together, this research disclosed that SIRT1 activator might perform its protective role in CAS through autophagy inhibition via wnt/β-catenin/GSK3β signaling pathway in EPCs.


Author(s):  
Jian Zhang ◽  
ZhenFeng Shi ◽  
JinXing Huang ◽  
XiaoGuang Zou

This study aimed to investigate the pivotal role of cystatin B (CSTB) in the development of gastric cancer and to explore its possible regulatory mechanism. Human gastric cancer SGC-7901 cells as a model in vitro were transfected with plasmid PCDNA3.1-CSTB and siRNA-CSTB using Lipofectamine 2000. Quantitative real-time PCR (qRT-PCR) and Western blotting were performed to determine the relative expression of CSTB and PI3K/Akt/mTOR pathway-related protein. Moreover, MTT assay, Transwell assay, and flow cytometry were used to assess cell proliferation, migration, and apoptosis, respectively. The results showed that CSTB was significantly downregulated in SGC-7901 cells compared with gastric epithelial cells. CSTB was successfully overexpressed and suppressed after cells were transfected with pc-CSTB and si-CSTB, respectively. Moreover, cell viability and migration were significantly decreased after being transfected with pc-CSTB when compared with the control group, while being obviously increased after transfection with si-CSTB. However, cell apoptosis was significantly induced after being transfected with pc-CSTB, while being obviously suppressed after transfection with si-CSTB. Besides, the expression levels of p-PI3K, p-Akt, and p-mTOR proteins were all significantly decreased in the pc-CSTB transfection group when compared with the control group, while being increased in the si-CSTB transfection group. Our findings suggest that CSTB downregulation may promote the development of gastric cancer by affecting cell proliferation and migration, and the PI3K/Akt/mTOR signaling pathway was activated in this process. CSTB may serve as a potential therapeutic target for gastric cancer.


2021 ◽  
Vol 22 (6) ◽  
pp. 3046
Author(s):  
Ming-Huei Chou ◽  
Hui-Ching Chuang ◽  
Yu-Tsai Lin ◽  
Ming-Hsien Tsai ◽  
Ying-Hsien Kao ◽  
...  

Patients with advanced head and neck squamous cell carcinoma (HNSCC) usually show a dismal prognosis. It is this worthwhile to develop new, effective therapeutic regimens for these patients, such as molecular targeted therapy, which is promising as an alternative or combination treatment for HNSCC. The mammalian target of rapamycin (mTOR) pathway, which plays an important role in the carcinogenesis of HNSCC, is the most frequently activated, and is thus worthy of further investigation. In this study, two human HNSCC cell lines, FaDu and SAS, were evaluated for cell growth with trypan blue staining and tumor growth using an orthotopic xenograft model. The immunohistochemical expression of mTOR in the subcutaneous xenograft model and the inhibitory effects of docetaxel on the growth and state of activation of the PI3K/mTOR pathway were also evaluated and examined by colony formation and Western blot, respectively. Cell proliferation and migration were measured by water-soluble tetrazolium salt (WST-1) and OrisTM cell migration assay, respectively. Furthermore, the effects of rapamycin and BEZ235, a phosphatidylinositol 3-kinases (PI3K) and mTOR inhibitor in combination with docetaxel or CCL20 were evaluated in the FaDu and SAS cells. The results showed that the expression of mTOR was significantly higher in the SAS and FaDu xenograft models than in the control. Docetaxel treatment significantly suppressed HNSCC cell proliferation and migration in vitro via the PI3K/mTOR/CCL-20 signaling pathway. Additionally, when administered in a dose-dependent fashion, mTOR inhibitors inhibited the growth and migration of the HNSCC cells. This combination was synergistic with docetaxel, resulting in almost complete cell growth and migration arrest. In conclusion, docetaxel significantly inhibited HNSCC cell proliferation and migration in vitro via the PI3K/mTOR/CCL-20 signaling pathway. The synergistic and additive activity of mTOR inhibitors combined with docetaxel shows potential as a new treatment strategy for HNSCC.


2021 ◽  
Vol 30 ◽  
pp. 096368972110255
Author(s):  
Qing Wang ◽  
Kai Li ◽  
Xiaoliang Li

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Increasing evidence suggests that long non-coding RNAs (lncRNAs) function in the tumorigenesis of NSCLC. LINC00958, a newly identified lncRNA, has been reported to be closely linked to tumorigenesis in several cancers. However, its specific role in NSCLC remains unclear. In this study, we determined the expression of LINC00958 in NSCLC by RT-qPCR analysis and evaluated cell proliferation and migration by CCK-8 and transwell assays, respectively. We established a xenograft tumor model to examine the effect of LINC00958 on tumor growth in vivo. Luciferase reporter assays were performed to determine the interaction between LINC00958 and miR-204-3p and the interaction between miR-204-3p and KIF2A. We found that LINC00958 was up-regulated in NSCLC tissues and cell lines. Down-regulation of LINC00958 inhibited cell proliferation and migration in vitro and suppressed tumor growth in vivo. Besides, miR-204-3p was identified as a target of LINC00958 and miR-204-3p inhibitor could reverse the inhibitory effect of LINC00958 knockdown on proliferation and migration of NSCLC cells. We also validated that KIF2A, a direct target of miR-204-3p, was responsible for the biological role of LINC00958. KIF2A antagonized the effect of miR-204-3p on NSCLC cell proliferation and migration and was regulated by LINC00958/miR-204-3p. Taken together, these data indicate that the LINC00958/miR-204-3p/KIF2A axis is critical for NSCLC progression, which might provide a potential therapeutic target of NSCLC.


2020 ◽  
Vol 48 (9) ◽  
pp. 030006052095947
Author(s):  
Xinwen Zhang ◽  
Xingbao Han ◽  
Pengli Zuo ◽  
Xiuying Zhang ◽  
Hongbang Xu

Objective To detect the expression of CEA-related cell adhesion molecule 5 (CEACAM5) in non-small-cell lung cancer (NSCLC) and explore its function in the progression and development of NSCLC. Methods qRT-PCR and immunohistochemistry were performed to detect CEACAM5 expression in human NSCLC tissues and cell lines. The correlation between CEACAM5 expression and the clinicopathological features of patients with NSCLC was also investigated. MTT, colony formation, wound healing, and immunoblot assays were performed to detect the functions of CEACAM5 in NSCLC cells in vitro, and immunoblotting was used to detect the effects of CEACAM5 on p38–Smad2/3 signaling. Results CEACAM5 expression was elevated in human NSCLC tissues and cells. We further found that CEACAM expression was correlated with clinicopathological features including T division, lymph invasion, and histological grade in patients with NSCLC. The in vitro assays confirmed that CEACAM5 depletion inhibited the proliferation and migration of NSCLC cells by activating p38–Smad2/3 signaling. We verified the involvement of CEACAM5 in the suppression of NSCLC tumor growth in mice. Conclusion CEACAM5 stimulated the progression of NSCLC by promoting cell proliferation and migration in vitro and in vivo. CEACAM5 may serve as a potential therapeutic target for the treatment of NSCLC.


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