scholarly journals Cyclic Mechanical Stretch Ameliorates the Degeneration of Nucleus Pulposus Cells through Promoting the ITGA2/PI3K/AKT Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Dandan Wang ◽  
Yuanzhen Chen ◽  
Shengnan Cao ◽  
Pengcheng Ren ◽  
Haojun Shi ◽  
...  

Background. Intervertebral disc degeneration (IVDD) is one of the major causes of low back pain and motor deficiency. Nucleus pulposus (NP) degeneration plays a key role in the process of IVDD. The mechanical and biological interactions involved in NP degeneration have not been elucidated. The present study is aimed at investigating the effect and mechanism of cyclic mechanical stretch in regulating the function and degeneration of NP cells. Methods. NP cells were subjected to cyclic tensile stress (10% deformation) of 0.1 Hz for 8640 cycles. Cell proliferation was conducted through the MTT assay. The cell cycle and apoptosis were detected by flow cytometry. A gene expression profile chip was used to analyze the differentially expressed genes between the tensile stress group and the control group. Enrichment analysis of Gene Ontology (GO) annotation and signaling pathways were analyzed. Western blot and RNA interference were carried out to investigate the role of the ITGA2/PI3K/AKT pathway in the effect of cyclic mechanical stretch on NP cells. Results. NP cells exhibited a greater ( P < 0.05 ) growth rate in the tensile stress group compared to the control group. Cyclic mechanical stress significantly promoted the cell cycle transition of NP cells from the S phase to the G2/M phase. A fewer proportion of apoptotic cells were found in the tensile stress group ( P < 0.05 ), indicating that cyclic mechanical stretch inhibits NP cell apoptosis. Microarray analysis revealed 689 significant differentially expressed genes between the two groups ( P < 0.05 ), of which 333 genes were upregulated and another 356 genes were downregulated. Cyclic mechanical stretch altered the expression of 31 genes involved in the ITGA2/PI3K/AKT pathway and remarkably promoted this pathway in NP cells. Downregulation of ITGA2 and AKT further demonstrated that the PI3K/AKT pathway was responsible for the proliferation and COL2A1 expression of NP cells upon cyclic mechanical stretch. Conclusions. Cyclic mechanical stretch promoted the proliferation and cell cycle and reversely inhibited the apoptosis of NP cells. Cyclic mechanical stretch promoted COL2A1 expression and ameliorated the degeneration of NP cells via regulation of the ITGA2/PI3K/AKT signaling pathway. Our results may provide a potential target and a possibility of IVDD disease treatment by ameliorating the degenerative changes.

Author(s):  
Jie Ni ◽  
Ying Chen ◽  
Beibei Fei ◽  
Yan Zhu ◽  
Yibei Du ◽  
...  

Background: MicroRNAs are endogenous small noncoding RNAs, which play a critical role in regulating various biological and pathologic processes. Furthermore, miR-301a has been detected to be overly expressed in tumorigenic progression of ovarian cancer. However, the effects of miR-301a on ovarian cancer are still unclear. Objective: The objective of this study is to investigate the molecular mechanisms of miR-301a in epithelial ovarian cancer cells. Methods: The miR-301a expression in ovarian cancer cells was detected. Then, cell proliferation, cell cycle, and apoptosis of the miR-301a-mimic-transfected ovarian cancer cells were determined, as well as the effects of the miR-301a mimic on the PTEN/phosphoinositide 3-kinase (PI3K) signaling pathway were explored. Results: We found that the miR-301a expression levels were markedly upregulated in ovarian cancer tissues and cells, and upregulation of miR-301a-promoted cell viability and proliferation. Our results also showed that the miR-301a-mimic accelerated cell cycle progression of ovarian cancer cells by targeting the CDK4/Cyclin-D1 pathway but not the CDK2/Cyclin-E pathway. Moreover, transfection of the miR-301a mimic into ovarian cancer cells could decrease the PTEN expression while increasing the PI3K and Akt phosphorylation, as compared with the miR-301a inhibitor group and the negative control group. Conclusion: Therefore, miR-301a should be an oncogene in ovarian cancer, and overexpression of miR-301a promoted proliferation of ovarian cancer cells by modulating the PTEN/PI3K/Akt signaling pathway.


2021 ◽  
Vol 27 ◽  
Author(s):  
Simin Liang ◽  
Xiaojia Zhou ◽  
Duo Cai ◽  
Fernando Rodrigues-Lima ◽  
Li Wang

Background: Chidamide, a novel benzamide-type histone deacetylase (HDAC) inhibitor, exerts antitumor effects on several types of cancer. However, the role of Chidamide in chronic myeloid leukemia (CML) remains elusive. Therefore, the present study aimed to investigate the effects of Chidamide on CML cell proliferation and explore its underlying mechanism. Methods: Cell proliferation was assessed by CCK-8 assay, cell cycle distribution and apoptosis were detected by flow cytometry and the expression of related proteins was evaluated by western blot analysis. The potential mechanisms were systematically explored by the network-based pharmacological methods, including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. Results: The results revealed that Chidamide inhibited the proliferation of K562 cells in a dose- and time-dependent manner. In addition, Chidamide blocked cells in the G0/G1 phase via downregulating cyclin‑dependent kinase 4, and induced apoptosis via upregulating Bax and downregulating of Bcl-2. Additionally, using network-based pharmacological methods, we found that PI3K/AKT signaling pathway is involved and significantly related to cell proliferation in CML. Intriguingly, cell treatment with Chidamide suppressed the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway via decreasing the levels of phosphorylated (p)-PI3K and p-AKT. Moreover, insulin-like growth factor 1 (IGF-1), a PI3K/AKT activator, reversed the inhibitory effects of Chidamide on K562 cell proliferation. Conclusion: The study demonstrated that Chidamide may inhibit the proliferation of K562 cells by promoting cell cycle arrest and apoptosis via suppressing the PI3K/AKT pathway, suggesting that Chidamide could be a promising approach to the treatment of CML.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Liting Wen ◽  
Yu Ding ◽  
Xiaodong Chen ◽  
Keyong Tian ◽  
Danfeng Li ◽  
...  

Objective. To investigate the effects of S100A8 and S100A9 on proliferation in nasopharyngeal carcinoma cells and the regulatory effects of PI3K/Akt signaling pathway. Methods. Nasopharyngeal carcinoma cells (CNE1) were cultured and randomly divided into three groups: control group, S100A8/S100A9 overexpression group, and siRNA S100A8/S100A9 group. CCK-8 method was used to detect the effect of S100A8 and S100A9 on the viability of nasopharyngeal carcinoma cells. The effects of S100A8 and S100A9 on the colony forming ability of nasopharyngeal carcinoma cells were detected by colony forming assay. The effects of S100A8 and S100A9 on the proliferation of nasopharyngeal carcinoma cells were detected by EdU staining. The mRNA levels of PI3K and Akt were detected by RT-PCR. The expression levels of PI3K and Akt in NPC cells were detected by Western blot. Wortmannin, an inhibitor of PI3K/Akt pathway, was used to inhibit the activation of PI3K/Akt pathway. Results. Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were increased in the overexpression group. Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were decreased in the siRNA group. After inhibiting the activation of PI3K/Akt pathway, the viability of NPC cells in the overexpression group decreased significantly at 48 h and 72 h, while that in the siRNA group increased significantly. Conclusion. SiRNA S100A8 and S100A9 could inhibit the proliferation of nasopharyngeal carcinoma cells, and the underlying mechanism may be related to the inhibition of PI3K/Akt signaling pathway.


Author(s):  
Xueying Tong ◽  
Jiajuan Chen ◽  
Wei Liu ◽  
Hui Liang ◽  
Hezhong Zhu

AbstractCardiovascular diseases rank the top cause of morbidity and mortality worldwide and are usually associated with blood reperfusion after myocardial ischemia/reperfusion injury (MIRI), which often causes severe pathological damages and cardiomyocyte apoptosis. LSINCT5 expression in the plasma of MI patients (n = 53), healthy controls (n = 42) and hypoxia-reoxygenation (HR)-treated cardiomyocyte AC16 cells was examined using qRT-PCR. The effects of LSINCT5 on cell viability and apoptosis were detected by MTT and flow cytometry, respectively. The expression of apoptosis-related proteins Bcl2, Bax and caspase 3 were tested by Western blot. The interaction between LSINCT5 and miR-222 was predicted by bioinformatic analysis. Moreover, changes in viability and apoptosis of AC16 cells co-transfected with siLSINCT5 and miR-222 inhibitor after HR treatment were examined. At last, the expression of proteins in PI3K/AKT pathway, namely PTEN, PI3K and AKT, was examined to analyze the possible pathway participating in LSINCT5-mediated MI/RI. Our study showed that LSINCT5 expression was upregulated in the plasma of MI patients and HR-treated AC16 cells. LSINCT5 overexpression significantly decreased cell viability and apoptosis. Luciferase reporter gene assay and RNA pulldown assay showed that LSINCT5 was a molecular sponge of miR-222. MiR-222 silencing in AC16 cells simulated the phenotypes of MIRI patients and HR-treated cells, indicating that LSINCT5 functions via miR-222 to regulate proliferation and apoptosis of HR-treated AC16 cells. We also showed that proteins of PI3K/AKT signaling pathway were affected in HR-treated AC16 cells, and LSINTC5 knockdown rescued these effects. LncRNA LSINCT5 was upregulated during MI pathogenesis, and LSINCT5 regulated MIRI possibly via a potential LSINCT5/miR-222 axis and PI3K/AKT signaling pathway. Our findings may provide novel evidence for MIRI prevention.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Linwen Zhu ◽  
Zhe Li ◽  
Xiuchong Yu ◽  
Yao Ruan ◽  
Yijing Shen ◽  
...  

Abstract Background Recently, tRNA-derived fragments (tRFs) have been shown to serve important biological functions. However, the role of tRFs in gastric cancer has not been fully elucidated. This study aimed to identify the tumor suppressor role of tRF-5026a (tRF-18-79MP9P04) in gastric cancer. Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was first used to detect tRF-5026a expression levels in gastric cancer tissues and patient plasma. Next, the relationship between tRF-5026a levels and clinicopathological features in gastric cancer patients was assessed. Cell lines with varying tRF-5026a levels were assessed by measuring tRF-5026a using qRT-PCR. After transfecting cell lines with a tRF-5026a mimic or inhibitor, cell proliferation, colony formation, migration, apoptosis, and cell cycle were evaluated. The expression levels of related proteins in the PTEN/PI3K/AKT pathway were also analyzed by Western blotting. Finally, the effect of tRF-5026a on tumor growth was tested using subcutaneous tumor models in nude mice. Results tRF-5026a was downregulated in gastric cancer patient tissues and plasma samples. tRF-5026a levels were closely related to tumor size, had a certain diagnostic value, and could be used to predict overall survival. tRF-5026a was also downregulated in gastric cancer cell lines. tRF-5026a inhibited the proliferation, migration, and cell cycle progression of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Animal experiments showed that upregulation of tRF-5026a effectively inhibited tumor growth. Conclusions tRF-5026a (tRF-18-79MP9P04) is a promising biomarker for gastric cancer diagnostics and has tumor suppressor effects mediated through the PTEN/PI3K/AKT signaling pathway.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dongyong Yang ◽  
Yanqing Wang ◽  
Yajing Zheng ◽  
Fangfang Dai ◽  
Shiyi Liu ◽  
...  

Abstract Background Polycystic ovary syndrome (PCOS) is the most common hormonal disorder among reproductive-aged women worldwide, however, the mechanisms and progression of PCOS still unclear due to its heterogeneous nature. Using the human granulosa-like tumor cell line (KGN) and PCOS mice model, we explored the function of lncRNA UCA1 in the pathological progression of PCOS. Results CCK8 assay and Flow cytometry were used to do the cell cycle, apoptosis and proliferation analysis, the results showed that UCA1 knockdown in KGN cells inhibited cell proliferation by blocking cell cycle progression and promoted cell apoptosis. In the in vivo experiment, the ovary of PCOS mice was injected with lentivirus carrying sh-UCA1, the results showed that knockdown of lncRNA UCA1 attenuated the ovary structural damage, increased the number of granular cells, inhibited serum insulin and testosterone release, and reduced the pro-inflammatory cytokine production. Western blot also revealed that UCA1 knockdown in PCOS mice repressed AKT activation, inhibitor experiment demonstrated that suppression of AKT signaling pathway, inhibited the cell proliferation and promoted apoptosis. Conclusions Our study revealed that, in vitro, UCA1 knockdown influenced the apoptosis and proliferation of KGN cells, in vivo, silencing of UCA1 regulated the ovary structural damage, serum insulin release, pro-inflammatory production, and AKT signaling pathway activation, suggesting lncRNA UCA1 plays an important role in the pathological progression of PCOS.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Bing Jing ◽  
Hongjuan Ji ◽  
Rui Jiang ◽  
Jinlong Wang

Abstract Background Osteoporosis is a widespread chronic disease characterized by low bone density. There is currently no gold standard treatment for osteoporosis. The aim of this study was to explore the role and mechanism of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. Methods MC3T3-E1 cells were divided into control and different dose of Astragaloside (10, 20, 40, 50, and 60 μg/ml). Then, ALP and ARS staining were performed to identify the effects of Astragaloside for early and late osteogenic capacity of MC3T3-E1 cells, respectively. Real-time PCR and western blot were performed to assess the ALP, OCN, and OSX expression. PI3K/Akt signaling pathway molecules were then assessed by Western blot. Finally, PI3K inhibitor, LY294002, was implemented to assess the mechanism of Astragaloside in promoting osteogenic differentiation of MC3T3-E1 cells. Results Astragaloside significantly increased the cell viability than the control group. Moreover, Astragaloside enhanced the ALP activity and calcium deposition than the control groups. Compared with the control group, Astragaloside increased the ALP, OCN, and OSX expression in a dose-response manner. Western blot assay further confirmed the real-time PCR results. Astragaloside could significantly increase the p-PI3K and p-Akt expression than the control group. LY294002 partially reversed the promotion effects of Astragaloside on osteogenic differentiation of MC3T3-E1 cells. LY294002 partially reversed the promotion effects of Astragaloside on ALP, OCN, and OSX of MC3T3-E1 cells. Conclusion The present study suggested that Astragaloside promoted osteogenic differentiation of MC3T3-E1 cells through regulating PI3K/Akt signaling pathway.


Author(s):  
ZiJun Liao ◽  
Qi Zheng ◽  
Ting Wei ◽  
YanBing Zhang ◽  
JieQun Ma ◽  
...  

MicroRNAs (miRNAs) play crucial roles in tumorigenesis and tumor progression. miR-561 has been reported to be downregulated in gastric cancer and affects cancer cell proliferation and metastasis. However, the role and underlying molecular mechanism of miR-561 in human non-small cell lung cancer (NSCLC) remain unknown and need to be further elucidated. In this study, we discovered that miR-561 expression was downregulated in human NSCLC tissues and cell lines. The overexpression of miR-561 inhibited NSCLC cell proliferation and cell cycle G1/S transition and induced apoptosis. The inhibition of miR-561 facilitated cell proliferation and G1/S transition and suppressed apoptosis. miR-561 expression was inversely correlated with P-REX2a expression in NSCLC tissues. P-REX2a was confirmed to be a direct target of miR-561 using a luciferase reporter assay. The overexpression of miR-561 decreased P-REX2a expression, and the suppression of miR-561 increased P-REX2a expression. Particularly, P-REX2a silencing recapitulated the cellular and molecular effects observed upon miR-561 overexpression, and P-REX2a overexpression counteracted the effects of miR-561 overexpression on NSCLC cells. Moreover, both exogenous expression of miR-561 and silencing of P-REX2a resulted in suppression of the PTEN/AKT signaling pathway. Our study demonstrates that miR-561 inhibits NSCLC cell proliferation and G1/S transition and induces apoptosis through suppression of the PTEN/AKT signaling pathway by targeting P-REX2a. These findings indicate that miR-561 plays a significant role in NSCLC progression and serves as a potential therapeutic target for NSCLC.


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