scholarly journals OPN Inhibits Autophagy through CD44, Integrin and the MAPK Pathway in Osteoarthritic Chondrocytes

Author(s):  
Rui-Jun Bai ◽  
Di Liu ◽  
Yu-Sheng Li ◽  
Jian Tian ◽  
Deng-Jie Yu ◽  
...  

Abstract Background: To investigate whether OPN has an effect on autophagy in human osteoarthritic chondrocytes and determine the roles of CD44, αvβ3 integrin and the MAPK pathway in this progress. Methods: First, we cultured human OA chondrocytes in vitro and then treated cells with rhOPN to determine autophagy changes. Next , the anti-CD44 and anti-CD51/61 monoclonal antibodies (Abs) or isotype IgG were used to determine the possible role of CD44 and αvβ3 integrin; subsequently, an inhibitor of the ERK MAPK pathway was used to investigate the role of ERK MAPK. Western blotting was used to measure the beclin1, LC3 II and MAPK protein expression, and mRFP-GFP-LC3 confocal imaging was used to detect the autophagy levels. CCK-8 was used to assay the proliferation and activity of chondrocytes. Results: Our results showed that the LC3 protein was greatly decreased in OA cartilage compared to normal cartilage ,and OPN suppressed the autophagy activity in chondrocytes in vitro. Blocking experiments with anti-CD44 and anti-CD51/61 Abs indicated that OPN could suppress the expression of LC3II and beclin1 through αvβ3 integrin and CD44. Our results also indicated that the ratio of p-ERK/ ERK but not p-P38/P38 and p-JNK/JNK was increased after the rhOPN treatment. The ERK inhibitor inhibited the activity of OPN in the suppression of autophagy, and the CCK-8 results showed that rhOPN could promote chondrocyte proliferation. Conclusions: OPN inhibited chondrocyte autophagy through CD44 and αvβ3 integrin receptors and via the ERK MAPK signaling pathway.

Author(s):  
Shan Lei ◽  
Zhiwei He ◽  
Tengxiang Chen ◽  
Xingjun Guo ◽  
Zhirui Zeng ◽  
...  

Abstract Background Accumulation evidence indicates the vital role of long non-coding RNAs (lncRNAs) in tumorigenesis and the progression of malignant tumors, including pancreatic cancer (PC). However, the role and the molecular mechanism of long non-coding RNA 00976 is unclear in pancreatic cancer. Methods In situ hybridization (ISH) and qRT-PCR was performed to investigate the association between linc00976 expression and the clinicopathological characteristics and prognosis of patients with PC. Subsequently, linc00976 over-expression vector and shRNAs were transfected into PC cells to up-regulate or down-regulate linc00976 expression. Loss- and gain-of function assays were performed to investigate the role of linc00976 in proliferation and metastasis in vitro and vivo. ITRAQ, bioinformatic analysis and rescue assay were used to illustrate the ceRNA mechanism network of linc00976/miR-137/OTUD7B and its downstream EGFR/MAPK signaling pathway. Results linc00976 expression was overexpressed in PC tissues and cell lines and was positively associated with poorer survival in patients with PC. Function studies revealed that linc00976 knockdown significantly suppressed cell proliferation, migration and invasion in vivo and in vitro, whereas its overexpression reversed these effects. Based on Itraq results and online database prediction, Ovarian tumor proteases OTUD7B was found as a downstream gene of linc00976, which deubiquitinated EGFR mediates MAPK signaling activation. Furthermore, Bioinformatics analysis and luciferase assays and rescue experiments revealed that linc00976/miR137/OTUD7B established the ceRNA network modulating PC cell proliferation and tumor growth. Conclusion The present study demonstrates that linc00976 enhances the proliferation and invasion ability of PC cells by upregulating OTUD7B expression, which was a target of miR-137. Ultimately, OTUD7B mediates EGFR and MAPK signaling pathway, suggesting that linc00976/miR-137/OTUD7B/EGFR axis may act as a potential biomarker and therapeutic target for PC.


2020 ◽  
Vol 86 (3) ◽  
pp. 361-374
Author(s):  
Marianna Lucafò ◽  
Daria Sicari ◽  
Andrea Chicco ◽  
Debora Curci ◽  
Arianna Bellazzo ◽  
...  

Abstract Glucocorticoids (GCs) are commonly used as therapeutic agents for immune-mediated diseases and leukemia. However, considerable inter-individual differences in efficacy have been reported. Several reports indicate that the inhibitor of mTOR rapamycin can reverse GC resistance, but the molecular mechanism involved in this synergistic effect has not been fully defined. In this context, we explored the differential miRNA expression in a GC-resistant CCRF-CEM cell line after treatment with rapamycin alone or in co-treatment with methylprednisolone (MP). The expression analysis identified 70, 99 and 96 miRNAs that were differentially expressed after treatment with MP, rapamycin and their combination compared to non-treated controls, respectively. Two pathways were exclusively altered as a result of the co-treatment: the MAPK and ErbB pathways. We validated the only miRNA upregulated specifically by the co-treatment associated with the MAPK signaling, miR-331-3p. Looking for miR-331-3p targets, MAP2K7, an essential component of the JNK/MAPK pathway, was identified. Interestingly, MAP2K7 expression was downregulated during the co-treatment, causing a decrease in terms of JNK activity. miR-331-3p in mimic-transfected cells led to a significant decrease in MAP2K7 levels and promoted the reversion of GC resistance in vitro. Interestingly, miR-331-3p expression was also associated with GC-resistance in patient leukemia cells taken at diagnosis. The combination of rapamycin with MP restores GC effectiveness through the regulation of different miRNAs, suggesting the important role of these pharmacoepigenetic factors in GC response.


2014 ◽  
Vol 28 (12) ◽  
pp. 1999-2011 ◽  
Author(s):  
Allyson Booth ◽  
Tammy Trudeau ◽  
Crystal Gomez ◽  
M. Scott Lucia ◽  
Arthur Gutierrez-Hartmann

The signaling pathways that govern the lactotrope-specific differentiated phenotype, and those that control lactotrope proliferation in both physiological and pathological lactotrope expansion, are poorly understood. Moreover, the specific role of MAPK signaling in lactotrope proliferation vs differentiation, whether activated phosphorylated MAPK is sufficient for prolactinoma tumor formation remain unknown. Given that oncogenic Ras mutations and persistently activated phosphorylated MAPK are found in human tumors, including prolactinomas and other pituitary tumors, a better understanding of the role of MAPK in lactotrope biology is required. Here we directly examined the role of persistent Ras/MAPK signaling in differentiation, proliferation, and tumorigenesis of rat pituitary somatolactotrope GH4 cells. We stimulated Ras/MAPK signaling in a persistent, long-term manner (over 6 d) in GH4 cells using two distinct approaches: 1) a doxycycline-inducible, oncogenic V12Ras expression system; and 2) continuous addition of exogenous epidermal growth factor. We find that long-term activation of the Ras/MAPK pathway over 6 days promotes differentiation of the bihormonal somatolactotrope GH4 precursor cell into a prolactin-secreting, lactotrope cell phenotype in vitro and in vivo with GH4 cell xenograft tumors. Furthermore, we show that persistent activation of the Ras/MAPK pathway not only fails to promote cell proliferation, but also diminishes tumorigenic characteristics in GH4 cells in vitro and in vivo. These data demonstrate that activated MAPK promotes differentiation and is not sufficient to drive tumorigenesis, suggesting that pituitary lactotrope tumor cells have the ability to evade the tumorigenic fate that is often associated with Ras/MAPK activation.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Fang-Fang Sun ◽  
Peng-Fei Hu ◽  
Yan Xiong ◽  
Jia-Peng Bao ◽  
Jing Qian ◽  
...  

Tricetin is a well-studied flavonoid with a wide range of pharmacological activities in cancer and inflammation. However, the ability of tricetin to ameliorate the inflammation that occurs in osteoarthritis (OA) has not been determined. This study explored the effects of tricetin on interleukin- (IL-) 1β-induced rat chondrocytes. Chondrocytes harvested from rat cartilage were incubated in vitro with tricetin in the presence of IL-1β. The expression of matrix metalloproteinase- (MMP-) 1, MMP-3, MMP-13, nitric oxide (NO), prostaglandin E2 (PGE2), Bax, and Bcl-2 was evaluated by real-time-PCR, ELISA, Griess reaction, and western blotting. Caspase-3 activity in chondrocytes was determined using a caspase-3 activity assay and MAPK pathway activity by western blotting. Tricetin decreased the expression of MMP-1, MMP-3, and MMP-13 at both the gene and protein level in IL-1β-induced rat chondrocytes. It also inhibited IL-1β-induced NO and PGE2 production, by modulating inducible NO synthase and cyclooxygenase 2 gene expression. An antiapoptotic role of tricetin involving the Bax/Bcl-2/caspase-3 pathway was also determined. The chondroprotective effect of tricetin was shown to be partly related to the suppression of the MAPK signaling pathway. The results of this study demonstrate the chondroprotective role of tricetin, based on its anticatabolic, anti-inflammatory, and antiapoptotic effects in chondrocytes. The therapeutic potential of tricetin in OA patients should be explored in future studies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingzhi Tang ◽  
Zhimin Chen ◽  
Qi Wang ◽  
Weijie Hao ◽  
Wei-Qiang Gao ◽  
...  

HNRNPA2B1, an RNA-binding protein, plays a key role in primary microRNA processing, alternative splicing, mRNA metabolism and transport. Interestingly, hnRNPA2B1 also works as an N6-methyladenosine (m6A) reader and is critical during tumorigenesis of various tissue types. However, its role in colon cancer is still unclear. In this study, we aimed to elucidate the biological functions of hnRNPA2B1 and to explore its underlying mechanisms in colon cancer. We examined the expression of hnRNPA2B1 in Oncomine and TCGA databases. Then verified the findings in colon cancer cells and clinical samples with western blotting and immunohistochemistry (IHC). We used CRISPR/Cas9 directed gene editing to knockout hnRNPA2B1 expression in human colon cancer cell line SW480 and HCT-116 and carried out both in vivo and in vitro experiments. The results were further confirmed by RNA-seq analyses. We found that hnRNPA2B1 significantly promoted colon cancer cell proliferation both in vitro and in vivo, while knockout of hnRNPA2B1 induced apoptosis and cell cycle arrest in SW480. RNA-seq analyses revealed that the ERK/MAPK pathway was activated by hnRNPA2B1 upregulation. In addition, both hnRNPA2B1 and MAPK pathway were activated in clinical colon cancer specimens and positively correlated. Mechanistically, hnRNPA2B1 appeared to be an upstream regulator of the ERK/MAPK pathway and inhibition of MAPK signaling blocked the effects of hnRNPA2B1. Taken together, our data demonstrated that the RNA-binding protein hnRNPA2B1 promotes cell proliferation and regulates cell cycle and apoptosis of human colon cancer by activating the ERK/MAPK signaling, which may provide a new insight into the development of hnRNPA2B1 as a potential therapeutic target for treatment of colon cancer.


2016 ◽  
Vol 40 (3-4) ◽  
pp. 644-656 ◽  
Author(s):  
Danni Wang ◽  
Danbo Wang ◽  
Ning Wang ◽  
Zaiqiu Long ◽  
Xuemei Ren

Background/Aims: Microarray screening had found BRAF-activated non-coding RNA (BANCR) was significantly upregulated in type 1 endometrial cancer (EC). This study aimed to assess the potential role of long non-coding RNA (lncRNA) BANCR in the pathogenesis and progression of type 1 EC. Methods: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to confirm the expression of BANCR in type 1 EC tissue, and analyze its clinical significance. In vitro, RNA interference (siRNA) was used to investigate the biological role of BANCR in type 1 EC. Results: qRT-PCR revealed that the expression of lncRNA BANCR was higher in type 1 EC (P<0.01). BANCR expression was significantly correlated with FIGO stage, pathological grade, myometrial invasion, and lymph node metastasis. The expression of BANCR was significantly correlated with that of MMP2/MMP1. In vitro, knockdown of BANCR significantly suppressed proliferation, migration, and invasion of Ishikawa and HEC-1A cells, and significantly inhibited the ERK/MAPK signaling pathway that decreased MMP2 and MMP1 expression. Conclusion: BANCR is highly expressed in type 1 EC tissue and promotes EC-cell proliferation, migration, and invasion by activating ERK/MAPK signaling pathway that regulates MMP2/MMP1 expression. BANCR is expected to become a prognostic marker and therapeutic target in type 1 EC.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2248 ◽  
Author(s):  
Jian-Ming Chen ◽  
Pei-Yin Chen ◽  
Chia-Chieh Lin ◽  
Ming-Chang Hsieh ◽  
Jen-Tsun Lin

Background: Sesamin is a lignin present in sesame oil from the bark of Zanthoxylum spp. Sesamin reportedly has anticarcinogenic potential and exerts anti-inflammatory effects on several tumors. Hypothesis/Purpose: However, the effect of sesamin on metastatic progression in human head and neck squamous carcinoma (HNSCC) remains unknown in vitro and in vivo; hence, we investigated the effect of sesamin on HNSCC cells in vitro. Methods and Results: Sesamin-treated human oral cancer cell lines FaDu, HSC-3, and Ca9-22 were subjected to a wound-healing assay. Furthermore, Western blotting was performed to assess the effect of sesamin on the expression levels of matrix metalloproteinase (MMP)-2 and proteins of the MAPK signaling pathway, including p-ERK1/2, P-p38, and p-JNK1/2. In addition, we investigated the association between MMP-2 expression and the MAPK pathway in sesamin-treated oral cancer cells. Sesamin inhibited cell migration and invasion in FaDu, Ca9-22, and HSC-3 cells and suppressed MMP-2 at noncytotoxic concentrations (0 to 40 μM). Furthermore, sesamin significantly reduced p38 MAPK and JNK phosphorylation in a dose-dependent manner in FaDu and HSC-3 cells. Conclusions: These results indicate that sesamin suppresses the migration and invasion of HNSCC cells by regulating MMP-2 and is thus a potential antimetastatic agent for treating HNSCC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sireesh Kumar Teertam ◽  
Phanithi Prakash Babu

AbstractCerebral ischemia (CI) is a severe cause of neurological dysfunction and mortality. Sirtuin-1 (Silent information regulator family protein 1, SIRT1), an oxidized nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase, plays an important role in protection against several neurodegenerative disorders. The present study aims to investigate the protective role of SIRT1 after CI in experimental young and aged rats and humans. Also, the study examines the possible regulatory mechanisms of neuronal death in CI settings. Immunoblotting and immunohistochemistry were used to evaluate changes in the expression of SIRT1, JNK/ERK/MAPK/AKT signaling, and pro-apoptotic caspase-3 in experimental rats and CI patients. The study findings demonstrated that, in aged experimental rats, SIRT1 activation positively influenced JNK and ERK phosphorylation and modulated neuronal survival in AKT-dependent manner. Further, the protection conferred by SIRT1 was effectively reversed by JNK inhibition and increased pro-apoptotic caspase-3 expression. In young experimental rats, SIRT1 activation decreased the phosphorylation of stress-induced JNK, ERK, caspase-3, and increased the phosphorylation of AKT after CI. Inhibition of SIRT1 reversed the protective effect of resveratrol. More importantly, in human patients, SIRT1 expression, phosphorylation of JNK/ERK/MAPK/AKT signaling and caspase-3 were up-regulated. In conclusion, SIRT1 could possibly be involved in the modulation of JNK/ERK/MAPK/AKT signaling pathway in experimental rats and humans after CI.


1993 ◽  
Vol 101 (4) ◽  
pp. 605-608 ◽  
Author(s):  
Joseph G Morelli ◽  
Joseph J Yohn ◽  
Tamara Zekman ◽  
David A Norris

2020 ◽  
Author(s):  
Hongyu Zheng ◽  
Tingting Wang ◽  
Xiangmin Li ◽  
Wei He ◽  
Zhiqiang Gong ◽  
...  

Abstract Background: Intervertebral disc degeneration (IDD) is characterized by the loss of nucleus pulposus cells (NPCs) and phenotypic abnormalities. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) are involved in the pathogenesis of IDD. In this study, we aimed to investigate the functional effects of lncRNA MALAT1 on NPCs in IDD and the possible mechanism governing these effects. Results: We validated the decreased expression of MALAT1 in the IDD tissues, which was associated with decreased Collagen II and Aggrecan expression. In vitro, overexpressed MALAT1 could attenuate the effect of IL-1β on NPC proliferation, apoptosis, and Aggrecan degradation. In vivo, MALAT1 overexpression attenuated the severity of disc degeneration in IDD model rats. Our molecular study further demonstrated that MALAT1 could sponge miR-503, modulate the expression of miR-503, and activate downstream MAPK signaling pathways. The effects of MALAT1 on NPCs were partially reversed/aggregated by miR-503 mimics/inhibitor treatment. Conclusion: Our data suggested that the MALAT1-miR-503-MAPK pathway plays a critical role in NPCs, which may be a potential strategy for alleviating IDD.


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