scholarly journals circPDE4B prevents articular cartilage degeneration and promotes repair by acting as a scaffold for RIC8A and MID1

2021 ◽  
pp. annrheumdis-2021-219969
Author(s):  
Shuying Shen ◽  
Yute Yang ◽  
Panyang Shen ◽  
Jun Ma ◽  
Bin Fang ◽  
...  

ObjectivesCircular RNAs (circRNAs) have emerged as significant biological regulators. Herein, we aimed to elucidate the role of an unidentified circRNA (circPDE4B) that is reportedly downregulated in osteoarthritis (OA) tissues.MethodsThe effects of circPDE4B were explored in human and mouse chondrocytes in vitro. Specifically, RNA pull-down (RPD)-mass spectrometry analysis (MS), immunoprecipitation, glutathione-S-transferase (GST) pull-down, RNA immunoprecipitation and RPD assays were performed to verify the interactions between circPDE4B and the RIC8 guanine nucleotide exchange factor A (RIC8A)/midline 1 (MID1) complex. A mouse model of OA was also employed to confirm the role of circPDE4B in OA pathogenesis in vivo.ResultscircPDE4B regulates chondrocyte cell viability and extracellular matrix metabolism. Mechanistically, FUS RNA binding protein (FUS) was found to promote the splicing of circPDE4B, while downregulation of circPDE4B in OA is partially caused by upstream inhibition of FUS. Moreover, circPDE4B facilitates the association between RIC8A and MID1 by acting as a scaffold to promote RIC8A degradation through proteasomal degradation. Furthermore, ubiquitination of RIC8A at K415 abrogates RIC8A degradation. The circPDE4B–RIC8A axis was observed to play an important role in regulating downstream p38 mitogen-activated protein kinase (MAPK) signalling. Furthermore, delivery of a circPDE4B adeno-associated virus (AAV) abrogates the breakdown of cartilage matrix by medial meniscus destabilisation in mice, whereas a RIC8A AAV induces the opposite effect.ConclusionThis work highlights the function of the circPDE4B–RIC8A axis in OA joints, as well as its regulation of MAPK-p38, suggesting this axis as a potential therapeutic target for OA.

Author(s):  
Andreas W Heumüller ◽  
Alisha Nicole Jones ◽  
André Mourão ◽  
Marius Klangwart ◽  
Chenyue Shi ◽  
...  

Background : Circular RNAs (circRNAs) are generated by back-splicing of mostly mRNAs and are gaining increasing attention as a novel class of regulatory RNAs that control various cellular functions. However, their physiological roles and functional conservation in vivo are rarely addressed, given the inherent challenges of their genetic inactivation. Here we aimed to identify locus conserved circRNAs in mice and humans, which can be genetically deleted due to retained intronic elements not contained in the mRNA host gene to eventually address functional conservation. Methods: Mechanistically, we identified the protein syndesmos (SDOS) to specifically interact with cZNF292 in endothelial cells by RNA affinity purification and subsequent mass spectrometry analysis. Silencing of SDOS or its protein binding partner Syndecan-4, or mutation of the SDOS-cZNF292 binding site, prevented laminar flow-induced cytoskeletal reorganisation thereby recapitulating cZfp292 phenotypes. Results: Combining published endothelial RNA sequencing datasets with circRNAs of the circATLAS databank, we identified locus-conserved circRNA retaining intronic elements between mice and humans. CRISPR/Cas9 mediated genetic depletion of the top expressed circRNA cZfp292 resulted in an altered endothelial morphology and aberrant flow alignment in the aorta in vivo. Consistently, depletion of cZNF292 in endothelial cells in vitro abolished laminar flow-induced alterations in cell orientation, paxillin localisation and focal adhesion organisation. Conclusion: Together, our data reveal a hitherto unknown role of cZNF292/cZfp292 in endothelial flow responses, which influences endothelial shape.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhisheng Long ◽  
Feipeng Gong ◽  
Yuxu Li ◽  
Zhiqiang Fan ◽  
Jingtang Li

Abstract Background Circular RNAs (circRNAs) are important regulators in the pathogenesis of diseases and affects the occurrence and development of diseases. However, the role of circRNAs in osteosarcoma (OS) has not been fully elucidated. Methods The expression of circ_0000285, miR-409-3p and insulin-like growth factor binding protein 3 (IGFBP3) was detected using quantitative real-time PCR (qRT-PCR). The protein level of IGFBP3 was measured using western blot. CCK-8 and colony formation assays were used to determine cell proliferation. Flow cytometry was applied to measure cell cycle and cell apoptosis. Transwell assay was used to assess cell invasion and migration. Dual-luciferase reporter assay and RNA Binding Protein Immunoprecipitation (RIP) assay were performed to determine the relationship among circ_0000285, miR-409-3p and IGFBP3. The animal experiments were performed to determine the function of circ_0000285 in vivo. Results In this study, we found that the expression of circ_0000285 was significantly increased in OS tissues and cells and was enriched in the cytoplasm. Knockdown of circ_0000285 inhibited OS growth in vitro and in vivo. Moreover, miR-409-3p was a target miRNA of circ_0000285 and miR-409-3p targets to IGFBP3 in OS. Besides, circ_0000285 could promote proliferation, migration, invasion and inhibit apoptosis of osteosarcoma by miR-409-3p/IGFBP3 axis. Conclusion In this study, circ_0000285 regulated proliferation, migration, invasion and apoptosis of OS cells by miR-409-3p/IGFBP3 axis, implying that circ_0000285 was a potential target for OS therapy.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Hui Zhang ◽  
Xingyuan Xiao ◽  
Wenjie Wei ◽  
Chao Huang ◽  
Miao Wang ◽  
...  

Abstract Background Cisplatin (CDDP) has become a standard-of-care treatment for muscle-invasive bladder cancer (MIBC), while chemoresistance remains a major challenge. Accumulating evidence indicates that circular RNAs (circRNAs) are discrete functional entities. However, the regulatory functions as well as complexities of circRNAs in modulating CDDP-based chemotherapy in bladder cancer are yet to be well revealed. Methods Through analyzing the expression profile of circRNAs in bladder cancer tissues, RNA FISH, circRNA pull-down assay, mass spectrometry analysis and RIP, circLIFR was identified and its interaction with MSH2 was confirmed. The effects of circLIFR and MSH2 on CDDP-based chemotherapy were explored by flow cytometry and rescue experiments. Co-IP and Western blot were used to investigate the molecular mechanisms underlying the functions of circLIFR and MSH2. Biological implications of circLIFR and MSH2 in bladder cancer were implemented in tumor xenograft models and PDX models. Results CircLIFR was downregulated in bladder cancer and expression was positively correlated with favorable prognosis. Moreover, circLIFR synergizing with MSH2, which was a mediator of CDDP sensitivity in bladder cancer cells, positively modulated sensitivity to CDDP in vitro and in vivo. Mechanistically, circLIFR augmented the interaction between MutSα and ATM, ultimately contributing to stabilize p73, which triggered to apoptosis. Importantly, MIBC with high expression of circLIFR and MSH2 was more sensitive to CDDP-based chemotherapy in tumor xenograft models and PDX models. Conclusions CircLIFR could interact with MSH2 to positively modulate CDDP-sensitivity through MutSα/ATM-p73 axis in bladder cancer. CircLIFR and MSH2 might be act as promising therapeutic targets for CDDP-resistant bladder cancer.


Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.


2021 ◽  
Vol 16 (1) ◽  
pp. 523-536
Author(s):  
Minghao Li ◽  
Jianbin Zhuang ◽  
Di Kang ◽  
Yuzhuo Chen ◽  
Weiliang Song

Abstract Colorectal cancer (CRC) is the third most common malignancy worldwide. Circular RNAs (circRNAs) have been implicated in cancer biology. The purpose of the current work is to investigate the precise parts of circRNA centrosome and spindle pole-associated protein 1 (circ-CSPP1) in the progression of CRC. Our data showed that circ-CSPP1 was significantly overexpressed in CRC tissues and cells. The knockdown of circ-CSPP1 attenuated cell proliferation, migration, invasion and promoted apoptosis in vitro and weakened tumor growth in vivo. circ-CSPP1 directly targeted miR-431, and circ-CSPP1 knockdown modulated CRC cell progression in vitro via upregulating miR-431. Moreover, LIM and SH3 protein 1 (LASP1) was a functional target of miR-431 in modulating CRC cell malignant progression. Furthermore, circ-CSPP1 in CRC cells functioned as a posttranscriptional regulator on LASP1 expression by targeting miR-431. Our present study identified the oncogenic role of circ-CSPP1 in CRC partially by the modulation of the miR-431/LASP1 axis, providing evidence for circ-CSPP1 as a promising biomarker for CRC management.


Plants ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 79 ◽  
Author(s):  
María Ibáñez ◽  
María Blázquez

The chemical composition of winter savory, peppermint, and anise essential oils, and in vitro and in vivo phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, and Echinochloa crus-galli) and food crops (maize, rice, and tomato), have been studied. Sixty-four compounds accounting for between 97.67–99.66% of the total essential oils were identified by Gas Chromatography-Mass Spectrometry analysis. Winter savory with carvacrol (43.34%) and thymol (23.20%) as the main compounds produced a total inhibitory effect against the seed germination of tested weed. Menthol (48.23%), menthone (23.33%), and iso-menthone (16.33%) from peppermint only showed total seed germination inhibition on L. multiflorum, whereas no significant effects were observed with trans-anethole (99.46%) from anise at all concentrations (0.125–1 µL/mL). Low doses of peppermint essential oil could be used as a sustainable alternative to synthetic agrochemicals to control L. multiflorum. The results corroborate that in vivo assays with a commercial emulsifiable concentrate need higher doses of the essential oils to reproduce previous in vitro trials. The higher in vivo phytotoxicity of winter savory essential oil constitutes an eco-friendly and less pernicious alternative to weed control. It is possible to achieve a greater in vivo phytotoxicity if less active essential oil like peppermint is included with other active excipients.


Nanomedicine ◽  
2021 ◽  
Author(s):  
Andre Gonçalves Prospero ◽  
Lais Pereira Buranello ◽  
Carlos AH Fernandes ◽  
Lucilene Delazari dos Santos ◽  
Guilherme Soares ◽  
...  

Background: We evaluated the impacts of corona protein (CP) formation on the alternating current biosusceptometry (ACB) signal intensity and in vivo circulation times of three differently coated magnetic nanoparticles (MNP): bare, citrate-coated and bovine serum albumin-coated MNPs. Methods: We employed the ACB system, gel electrophoresis and mass spectrometry analysis. Results: Higher CP formation led to a greater reduction in the in vitro ACB signal intensity and circulation time. We found fewer proteins forming the CP for the bovine serum albumin-coated MNPs, which presented the highest circulation time in vivo among the MNPs studied. Conclusion: These data showed better biocompatibility, stability and magnetic signal uniformity in biological media for bovine serum albumin-coated MNPs than for citrate-coated MNPs and bare MNPs.


2021 ◽  
Author(s):  
Hongwei Chu ◽  
Changqing Wu ◽  
Qun Zhao ◽  
Rui Sun ◽  
Kuo Yang ◽  
...  

Abstract Sorafenib is commonly used to treat advanced human hepatocellular carcinoma (HCC). However, clinical efficacy has been limited by drug resistance. In this study, we used label-free quantitative proteomic analysis to systematically investigate the underlying mechanisms of sorafenib resistance in HCC cells. A total of 1709 proteins were confidently quantified. Among them, 89 were differentially expressed, and highly enriched in the processes of cell-cell adhesion, negative regulation of apoptosis, response to drug and metabolic processes involving in sorafenib resistance. Notably, folate receptor α (FOLR1) was found to be significantly upregulated in resistant HCC cells. In addition, in-vitro studies showed that overexpression of FOLR1 decreased the sensitivity of HCC cells to sorafenib, whereas siRNA-directed knockdown of FOLR1 increased the sensitivity of HCC cells to sorafenib. Immunoprecipitation-mass spectrometry analysis suggested a strong link between FOLR1 and autophagy related proteins. Further biological experiments found that FOLR1-related sorafenib resistance was accompanied by the activation of autophagy, whereas inhibition of autophagy significantly reduced FOLR1-induced cell resistance. These results suggest the driving role of FOLR1 in HCC resistance to sorafenib, which may be exerted through FOLR1-induced autophagy. Therefore, this study may provide new insights into understanding the mechanism of sorafenib resistance.


2012 ◽  
Vol 80 (12) ◽  
pp. 4333-4343 ◽  
Author(s):  
Barak Hajaj ◽  
Hasan Yesilkaya ◽  
Rachel Benisty ◽  
Maayan David ◽  
Peter W. Andrew ◽  
...  

ABSTRACTStreptococcus pneumoniaeis an aerotolerant Gram-positive bacterium that causes an array of diseases, including pneumonia, otitis media, and meningitis. During aerobic growth,S. pneumoniaeproduces high levels of H2O2. SinceS. pneumoniaelacks catalase, the question of how it controls H2O2levels is of critical importance. Thepsalocus encodes an ABC Mn2+-permease complex (psaBCA) and a putative thiol peroxidase,tpxD. This study shows thattpxDencodes a functional thiol peroxidase involved in the adjustment of H2O2homeostasis in the cell. Kinetic experiments showed that recombinant TpxD removed H2O2efficiently. However,in vivoexperiments revealed that TpxD detoxifies only a fraction of the H2O2generated by the pneumococcus. Mass spectrometry analysis demonstrated that TpxD Cys58undergoes selective oxidationin vivo, under conditions where H2O2is formed, confirming the thiol peroxidase activity. Levels of TpxD expression and synthesisin vitrowere significantly increased in cells grown under aerobic versus anaerobic conditions. The challenge with D39 and TIGR4 with H2O2resulted intpxDupregulation, whilepsaBCAexpression was oppositely affected. However, the challenge of ΔtpxDmutants with H2O2did not affectpsaBCA, implying that TpxD is involved in the regulation of thepsaoperon, in addition to its scavenging activity. Virulence studies demonstrated a notable difference in the survival time of mice infected intranasally with D39 compared to that of mice infected intranasally with D39ΔtpxD. However, when bacteria were administered directly into the blood, this difference disappeared. The findings of this study suggest that TpxD constitutes a component of the organism's fundamental strategy to fine-tune cellular processes in response to H2O2.


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