Effects of RANKL on the proliferation and apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis through regulating the NF-κB signaling pathway
Authors: L Zhou
Y Wang
Y-Q Geng
L Li
Q Gao
Journal: European Review for Medical and Pharmacological Sciences (2019)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: RANKL; fibroblast-like synoviocytes; rheumatoid arthritis; proliferation; apoptosis
Affiliations: Department of Rheumatology and Immunology, The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University, Changzhou, China. .

Abstract:  Objective: The aim of this study is to investigate the regulatory effects of receptor activator of nuclear factor-kappa B ligand (RANKL) on the proliferation and apoptosis of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA), and to explore its regulatory mechanism. Materials and methods: Synoviocytes were primarily cultured in rats of recognized collagen-induced arthritis (CIA) model. Meanwhile, they were induced into FLS models by lipopolysaccharides (LPS). All cells were divided into three groups, including blank group, model group and RANKL inhibitor group. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) in the cells were detected by enzyme-linked immunosorbent assay (ELISA). The proliferation and apoptosis of FLS were detected via 3-(4,5)-dimethylthiazol (-z-y1)-3,5-diphenytetrazoliumromide (MTT) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was conducted to measure the messenger ribonucleic acid (mRNA) expression levels of nuclear factor-kappa B ligand (NF-κB) and Caspase-3 in FLS. Furthermore, Western blotting was adopted to detect the protein expression levels of NF-κB and Caspase-3 in FLS. Results: Compared with the blank group, the expression levels of TNF-α and IL-1β in the cells of the model group increased significantly. Cell proliferation rate increased significantly, whereas the cell apoptosis rate decreased remarkably in the model group. Meanwhile, the mRNA and protein levels of NF-κB and Caspase-3 in FLS were significantly up-regulated. Compared with the model group, the levels of TNF-α and IL-1β in cells of RANKL inhibitor group notably declined. Similarly, cell proliferation rate was significantly reduced, whereas the cell apoptosis rate increased significantly. Furthermore, the mRNA and protein levels of NF-κB and Caspase-3 in FLS were evidently down-regulated. Conclusions: RANKL inhibitors can inhibit the proliferation and promote the apoptosis of FLS in RA. In addition, its mechanism may be related to the inhibition of NF-κB signaling pathway. 

Retracted: No

PubPeer comments:
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 Figure 3A. * Pink boxes: The b-actin panel looks very similar to the b-actin panel in C.-H. Shi et al. (2019) Eur Rev Med Pharmacol Sci. DOI: 10.26355 eurrev_201911_19573, https: pubpeer.com publications 241A499EF70CB52D3CFD303BD0994F ![file] , 
 Figure 4A: The bottom parts of some lanes look very similar to those of lanes in other panels, albeit in a different order. In addition, the top parts appear to show some brush-stroke-like light dark stripes. Also, some of the bottom parts of the lanes look similar to lanes in Figure 3A of the above-mentioned paper by C.-H. Shi et al. (2019) Eur Rev Med Pharmacol Sci. DOI: 10.26355 eurrev_201911_19573, https: pubpeer.com publications 241A499EF70CB52D3CFD303BD0994F Boxes of the same color show areas that look similar. ![file] ,