scholarly journals Mechanism of Abnormal Chondrocyte Proliferation Induced by Piezo1-siRNA Exposed to Mechanical Stretch

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yi Sun ◽  
Ping Leng ◽  
Dawei Li ◽  
Huanshen Gao ◽  
Zhenghui Li ◽  
...  

Objective. To investigate the effect of small interfering RNA targeting mechanosensitive ion channel protein Piezo1 (Piezo1-siRNA) on abnormal chondrocyte proliferation exposed to mechanical stretch. Methods. Construct and screen effective Piezo1-siRNA sequences and explore an appropriate method to transfect lentiviral vector into chondrocytes exposed to mechanical stretch. Western blot and RT-PCR were used to detect the mRNA and protein expression of Piezo1, Kif18A, and β-tubulin, respectively. Flow cytometry was used to measure the changes in the chondrocyte cycle. The proliferation of chondrocyte was evaluated by cell counting kit-8. Results. According to the mRNA and protein expression of Piezo1, the effective siRNA sequence was successfully screened. Compared with the 0 h group, mechanical stretch upregulated the expression of Piezo1, Kif18A, and β-tubulin, resulting in chondrocyte cycle arrest and eventually inhibiting chondrocyte proliferation. Moreover, Piezo1-siRNA transfection effectively blocks this process and promotes the proliferation of chondrocyte. Conclusion. Piezo1-siRNA can reduce the inhibition of chondrocyte proliferation induced by mechanical stretch via downregulating the expression of Kif18A and inhibiting the depolymerization of microtubules. Piezo1-siRNA plays a protective role in chondrocytes, which provides a potential method for the treatment of OA under abnormal mechanical stimulation.

2017 ◽  
Vol 42 (5) ◽  
pp. 1769-1778 ◽  
Author(s):  
Ran Ao ◽  
Lin Guan ◽  
Ying Wang ◽  
Jia-Ni Wang

Background/Aims: This paper aims to explore the effects of pyruvate kinase (PK) M2 gene silencing on the proliferation and apoptosis of colorectal cancer (CRC) LS-147T and SW620 cells. Methods: CRC LS-147T and SW620 cells highly expressing PKM2 were randomly selected by quantitative real-time polymerase chain reaction (qRT-PCR) and then assigned into the blank (no transfection), PKM2-shRNA (transfection with shRNA) and empty plasmid (transfection with empty plasmid) groups. Immunofluorescence was applied to detect PKM2 protein expression. qRT-PCR and Western blotting were conducted to assess mRNA and protein expression of PKM2, p53 and p21. The cell counting kit-8 (CCK-8) assay was used to assess cell proliferation. Flow cytometry was used to assess the cell cycle and apoptosis rate, and a senescence-associated β-galactosidase staining kit was used to assess cell senescence. Results: PKM2 exhibited high mRNA expression among CRC LS-147T and SW620 cells with remarkable protein expression noted in the cytoplasm and nucleus. The PKM2-shRNA group exhibited reduced PKM2 mRNA and protein expression, whereas p53 and p21 expression was increased compared with the blank and empty plasmid groups. Cell proliferation in PKM2-shRNA cells decreased significantly compared with the blank group and empty plasmid groups. The PKM2-shRNA group exhibited more cells in the G1 phase and fewer cells in the G2/M phase compared with the blank and empty plasmid groups. In addition, the PKM2-shRNA group exhibited significantly increased apoptosis rates and β-galactosidase activity compared with the blank and empty plasmid groups. Conclusion: Our study demonstrates that PKM2 gene silencing suppresses proliferation and promotes apoptosis in LS-147T and SW620 cells.


2016 ◽  
Vol 28 (2) ◽  
pp. 194
Author(s):  
S. Gebremedhn ◽  
D. Salilew-Wondim ◽  
M. Hoelker ◽  
F. Rings ◽  
C. Neuhoff ◽  
...  

Among other microRNA clusters, we previously showed that the miR-183~96~182 cluster (miR-183, miR-96, and miR-182) is abundantly expressed in bovine granulosa cells (bGC) of preovulatory dominant follicles obtained at the follicular phase of the bovine oestrous cycle. Moreover, this miRNA cluster are validated to coordinately target the Fork head O1 (FOXO1), a subfamily of transcription factors that regulate genes involved in cell proliferation, apoptosis, cell cycle arrest, and metabolism. However, the functional involvement of miR-183~96~182 cluster in bGC function by regulation of FOXO1 is not yet determined. Here, we aimed to investigate the function of miR-183~96~182 cluster in bGC using in vitro cell culture model. For this, bGC were aspirated from ovarian follicles (Ø 3–5 mm) obtained from local abattoir. Cells were plated in 24-well plate (2.5 × 105 cells well–1) in DMEM/F-12 (Sigma, Germany) supplemented with 10% FBS (GIBCO, Grand Island, NY) and 1% penicillin/streptomycin (GIBCO) and incubated at 37°C in 5% CO2. Transfection of bGC with miRNA mimics, inhibitors, FOXO1-siRNA, and appropriate controls (Exiqon, Vedbæk, Denmark) was performed using Lipofectamine 2000 (Invitrogen, Carlsbad, CA, USA). Cell proliferation was determined using Cell Counting Kit-8 (CCK-8; Dojindo Molecular Technology, Kumamoto, Japan). Cell cycle distribution was determined with flow cytometric analysis. Total RNA was isolated using miRNeasy mini kit (Qiagen, Hilden, Germany), quantification of target gene was performed using qPCR, and data were analysed using ΔΔCT method. Differences in the mean expression values between treatments were analysed with two-tailed Student’s t-test and statistical significance was defined at P ≤ 0.05. Results showed that a sponge effect was observed upon inhibition in individual miRNA of the cluster, which could be attributed to the partial sequence similarity among cluster members. Both FOXO1 mRNA and protein expression were significantly reduced upon transfection of bGC with miR-183~96~182 cluster mimics, while miR-183~96~182 cluster inhibition increased both FOXO1 mRNA and protein expression. Transfection of bGC with miR-183~96~182 mimics promoted cell proliferation, while inhibition tends to slow down proliferation. Furthermore, the proportion of bGC under G0/G1 arrest markedly declined (P < 0.05), while the S and G2/M phases increased in response to miR-183~96~182 mimicking. Selective knockdown of FOXO1 with FOXO1-siRNA significantly reduced FOXO1 mRNA and protein expression. Interestingly, knockdown of FOXO1 showed similar phenotypic effects such as that of miR-183~96~182 mimics transfection, which resulted in elevated bGC proliferation and reduction in the proportion of cells under G0/G1 arrest. In conclusion, overexpression of miR-183~96~182 cluster promote bGC proliferation and G0/G1 to S and G2/M cell cycle transition through coordinated regulation of genes in the FOXO1 signaling axis.


2021 ◽  
Author(s):  
Xiao Wang ◽  
Yuqing Cui ◽  
Chao Han ◽  
Yumeng Geng ◽  
Di Zhang ◽  
...  

Abstract Salvia miltiorrhiza Polysaccharides (SMPs) can alleviate liver injury in mice, but there are few reports on liver injury of broilers, especially the liver injury caused by antibiotics. To explore the hepatoprotective effects of SMPs against florfenicol (FFC) induced broilers liver injury, the broilers were treated with FFC and SMPs. The results showed SMPs could significantly inhibit the decrease of weight gain and the increase of liver index induced by FFC (P < 0.05). SMPs could significantly reduce the contents of Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) in serum and the malondialdehyde (MDA), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in liver tissues (P < 0.05), also significantly increased the content of total protein (TP) in serum and superoxide dismutase (SOD), catalase (CAT) in liver tissues (P < 0.05). QPCR and western bolt results showed that SMPs significantly increased the mRNA and protein expression of cytochrome P4501A1 (CYP1A1), cytochrome P4502H1 (CYP2H1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone-1 (NQO-1) in liver tissue, also significantly reduced the rate of hepatocyte apoptosis and the mRNA and protein expression of p53, cytochrome-C (CytC), caspase-3 in liver tissue (P < 0.05). The results demonstrated that SMPs can inhibit the oxidative stress in hepatocytes by regulating the related proteins in Nrf2 pathway, thereby reducing the apoptosis of hepatocytes, and protecting liver injury.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bo Yang ◽  
Haisheng Huang ◽  
Qisong He ◽  
Wei Lu ◽  
Lu Zheng ◽  
...  

Oxidative stress-induced chondrocyte apoptosis and degradation of the extracellular matrix (ECM) play an important role in the progression of osteoarthritis (OA). In addition, tert-butylhydroquinone (TBHQ) is an activator of the nuclear factor erythroid derived-2-related factor 2 (Nrf2). The present study aimed to determine the effectiveness of TBHQ in preventing the apoptosis of chondrocytes and degradation of the extracellular matrix, induced by oxidative stress, in vitro. Therefore, rat chondrocytes were exposed to 20 μM tert-butyl hydroperoxide (TBHP) for 24 h to establish an oxidative damage model, in vitro. Thereafter, cell viability was evaluated using the Cell Counting Kit-8 assay. Moreover, the level of ROS was determined through 2′,7′-dichlorofluorescein diacetate staining. The mitochondrial membrane potential of chondrocytes was also measured using JC-1. Furthermore, cell apoptosis was assessed through Annexin V-fluorescein isothiocyanate/propidium iodide staining. The study also performed Western blotting and qPCR to evaluate the expression of extracellular matrix components, matrix catabolic enzymes, and changes in signalling pathways. The results showed that 2.5 and 5 μM of TBHQ reduced the TBHP-induced generation of excessive ROS and improved cell viability. Additionally, 2.5 and 5 μM of TBHQ prevented mitochondrial damage and apoptosis in rat chondrocytes. Treatment with TBHQ also increased the mRNA and protein expression levels of aggrecan and collagen II. However, TBHQ reduced the mRNA and protein expression levels of matrix metalloproteinase 3 (MMP3) and matrix metalloproteinase 13 (MMP13) in rat chondrocytes. In addition, treatment with TBHQ enhanced the protein expression levels of Nrf2, NADPH quinone oxidoreductase 1 (NQO-1), and hemeoxygenase-1 (HO-1) in rat chondrocytes. The current study showed that TBHQ was not only effective in protecting against TBHP-induced oxidative stress but also inhibited the apoptosis of rat chondrocytes and degradation of the ECM by activating the Nrf2 pathway. The results therefore suggest that TBHQ holds potential for use in the treatment of OA.


2021 ◽  
Author(s):  
xiangju long ◽  
Zhe Liu ◽  
Yanan Sun ◽  
Hong Zhang

Abstract CD36 is a receptor of OxLDL in kidney tubular epithelial cells(NRK-52E cells),nuclear factor erythroid 2-related factor 2 (Nrf2) is a crucial factor initiate Nrf2-signaling pathway regulating oxidative stress,kelch-like ECH-associated protein 1(Keap1) is called Nrf2 inhibitor.We treated NRK-52E cells by different concentration and time of OxLDL, and Nrf2 inhibitor ΚeapI ,and then observed CD36 ,cytoplasmic and nuleus of Nrf2 ,E-cadherinin in NRK-52E cells by western blotting and RT-PCR methods etc.,we found that CD36 protein in OxLDL stimulated NRK-52E cells increased after enough concentration and time;Although total Nrf2 protein level did not chang significantly at 5h,10h,but decreased at 24h,48h;Nuleus Nrf2 protein level increased relatively.Meanwhile, cytoplasmic Nrf2 protein level did not change significantly; CD36 mRNA and protein expression decreased in the NRK-52E renal tubular cells treated with Nrf2 inhibitor keap1; After OxLDL stimulation and then keap1 overexpression, CD36 mRNA and protein expression also decreased; E-cadherin expression decreased in NRK-52E after KeapI over-expression treatment .These results may indicateed that CD36 could accept OxLDL and then upregulated in NRK-52E cells ; Nrf2 could be activated by OxLDL, But Nrf2 could resist oxidative stress induced by OxLDL only if it transfer to the nucleus from cytoplasm.Nrf2 may play an protective role through upregulating CD36 .


2008 ◽  
Vol 295 (5) ◽  
pp. E1205-E1212 ◽  
Author(s):  
Utpal Sen ◽  
Walter E. Rodriguez ◽  
Neetu Tyagi ◽  
Munish Kumar ◽  
Soumi Kundu ◽  
...  

Diabetes and hyperhomocysteinemia (HHcy) are two independent risk factors for glomeruloslerosis and renal insufficiency. Although PPARγ agonists such as ciglitazone (CZ) are known to modulate diabetic nephropathy, the role of CZ in diabetes-associated HHcy and renopathy is incompletely defined. We tested the hypothesis that induction of PPARγ by CZ decreases tissue Hcy level; this provides a protective role against diabetic nephropathy. C57BL/6J mice were administered alloxan to create diabetes. Mice were grouped to 0, 1, 10, 12, and 16 wk of treatment; only 12- and 16-wk animals received CZ in drinking water after a 10-wk alloxan treatment. In diabetes, PPARγ cDNA, mRNA, and protein expression were repressed, whereas an increase in plasma and glomerular Hcy levels was observed. CZ normalized PPARγ mRNA and protein expression and glomerular level of Hcy, whereas plasma level of Hcy remained unchanged. GFR was dramatically increased at 1-wk diabetic induction, followed by hypofiltration at 10 wk, and was normalized by CZ treatment. This result corroborated with glomerular and preglomerular arteriole histology. A steady-state increase of RVR in diabetic mice became normal with CZ treatment. CZ ameliorated decrease bioavailability of NO in the diabetic animal. Glomerular MMP-2 and MMP-9 activities as well as TIMP-1 expression were increased robustly in diabetic mice and normalized with CZ treatment. Interestingly, TIMP-4 expression was opposite to that of TIMP-1 in diabetic and CZ-treated groups. These results suggested that diabetic nephropathy exacerbated glomerular tissue level of Hcy, and this caused further deterioration of glomerulus. CZ, however, protected diabetic nephropathy in part by activating PPARγ and clearing glomerular tissue Hcy.


Author(s):  
Jian Jiao ◽  
Puqi Hu ◽  
Ying Li ◽  
Chao Cai ◽  
Xiangdong Wang ◽  
...  

<b><i>Background:</i></b> Fine particulate matter (PM) (PM with an aerodynamic diameter &#x3c;2.5 μm, PM2.5) exposure contributes to respiratory disease development and exacerbation. <b><i>Objective:</i></b> We sought to investigate the effect of PM2.5 exposure on mucociliary function in primary human nasal epithelial cells (HNECs) and the underlying mechanism. <b><i>Methods:</i></b> HNECs derived from control subjects and patients with chronic rhinosinusitis with nasal polyps were established as air-liquid interface cultures. Confluent cultures were exposed to 100 or 200 μg/mL PM2.5 for 24 h and assessed for expression of specific mucociliary-associated factors, the percentage of β-tubulin IV-positive and MUC5AC-positive cells, expression of epidermal growth factor receptor (EGFR) ligand and activation of phosphoinositide 3-kinase (PI3K)-AKT/ERK. In addition, cultures pretreated for 30 min with AG1478 (an EGFR inhibitor) or LY294002 (a PI3K inhibitor) following PM2.5 exposure were assessed for MUC5AC mRNA and protein expression. <b><i>Results:</i></b> PM2.5 exposure at 100 or 200 μg/mL for 24 h did not affect geminin coiled-coil domain containing, multiciliate differentiation and DNA synthesis associated cell cycle protein, FOXJ1, or DNAI2 mRNA expression or the percentage of β-tubulin IV-positive cells. However, 200 μg/mL PM2.5 exposure significantly increased mRNA expression of SAM-pointed domain-containing ETS transcription factor and MUC5AC and the percentage of MUC5AC-positive cells. PM2.5 also increased expression of EGFR ligands, including heparin-binding EGF-like growth factor and amphiregulin. Furthermore, PM2.5induced activation of PI3K, AKT, and ERK, and pretreatment of HNECs with AG1478 or LY294002 attenuated PM2.5-induced MUC5AC mRNA and protein expression. <b><i>Conclusions and Clinical Relevance:</i></b> This study demonstrates that short-term PM2.5 exposure increases MUC5AC expression in HNECs. Furthermore, this study shows that PM2.5-induced MUC5AC expression is likely mediated through the EGFR-PI3K pathway.


2000 ◽  
Vol 111 (4) ◽  
pp. 1118-1121 ◽  
Author(s):  
A. Bellahcene ◽  
I. Van Riet ◽  
C. de Greef ◽  
N. Antoine ◽  
M. F. Young ◽  
...  

Author(s):  
Klaudia V. Nesvitaylova ◽  
Olga A. Gonchar ◽  
Tatyana I. Drevitskaya ◽  
Ludmila P. Arabskaya ◽  
Mikhail M. Steshenko ◽  
...  

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