MicroRNA-29a inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes by repressing STAT3
Authors: Juan Du
Dan Fei
Jie Xing
Jinxiang Liu
Journal: Biomedicine & Pharmacotherapy (2017)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Apoptosis; Proliferation; Rheumatoid arthritis; STAT3; miR-29a.
Affiliations: Department of Pediatric Rheumatology and Allergy, the First Affiliated Bethune Hospital, Jilin University, Changchun 130021, PR China., Ultrasonographic Department, the China-Ja‚Äãpan Union Hospital of Jilin University, Changchun, Jilin 130033, PR China., Department of Rheumatology and Immunology, the China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, PR China. Electronic address: .

Abstract:  Rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) with aberrant expression of microRNA (miRNA) have been reported to be involved in the initiation, progression, and perpetuation of rheumatoid arthritis (RA). In this study, we explored the biological function and underlying mechanism of microRNA-29a (miR-29a) in cultured RA-FLS from RA patients. The expression of miR-29a in serum, synovial tissues, and FLS from RA patients and health donors was detected by real-time quantitative RT-PCR (qRT-PCR). The effects of miR-29a on cell proliferation, apoptosis, and inflammatory cytokine levels in RA-FLS were also determined using Counting Assay Kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA) respectively. Luciferase reporter assay was carried out to identify the target genes of miR-29a. We observed that expression of miR-29a was markedly downregulated in serum, synovial tissues and FLS of RA patients. miR-29a overexpression in RA-FLS significantly inhibited proliferation, promoted apoptosis, and suppressed expression of inflammatory cytokines. Signal transducer and activator of transcription 3 (STAT3) was identified to be a direct target of miR-29a in RA-FLS. miR-29a overexpression suppressed the expression of STAT3, as well as phosphorylated STAT3(p-STAT3) and its downstream targets protein (Cyclin D1 and Bcl-2). In addition, the levels of miR-29a were inversely correlated with that of STAT3 in synovial tissues. Rescue experiments showed that overexpression of STAT3 effectively reversed the effect of miR-29a on proliferation and apoptosis in RA-FLS. These data indicate that miR-29a inhibits proliferation and induces apoptosis in RA-FLS by targeting STAT3, suggesting that promoting miR-29a expression may yield therapeutic benefits in the treatment of RA. 

Retracted: No

PubPeer comments:
 At left:  Fig. 3. miR-29a overexpression induces apoptosis of RA-FLS. (A) Apoptosis of RA-FLS was evaluated using flow cytometry after transfection of miR-29a mimic or miR-NC Contains two pairs of areas of unusual similarity. Without these replications, the panel would look even more similar to (at right) Fig 7(D),  Cell proliferation, cell cycle, and apoptosis were determined in RA-FLS transfected with miR-29a with without STAT3 overexpression plasmid .  , 
 Fig 7C. Two cell-cycle flow-cytometry plots appear to be the same.  , 
 Figs 5D, 7A.  STAT3, p-STAT3, CyclinD1, and Bcl-2 protein expression levels were determined by western blot in RA-FLS cells transfected with miR-29a mimic or miR-NC ;  STAT3 protein expression was measured by western blot in RA-FLS transfected with miR-29a miR-NC and with without STAT3 overexpression plasmid. GAPDH was used as an internal control .  Curiously, two STAT3 blobs are the same in the two figures, after a 180-deg flip (pink boxes). Brown, green, light green, blue and dark blue boxes mark more pairs of unexpectedly similar protein blobs. Even more curiously, the blobs marked with green, dark blue and red boxes **also** appear in Fig 5B from [Du et al (2019)] :  SOX12 expression on ... protein levels was measured in MCF-7 cells after transfection with miR-326 mimics with (or without) the SOX12-overexpression vector (pCDNA3.1-SOX12) or miR-NC .  And again, in *[left]* Fig 5B from [Xu et al (2018)] .  Western blot analysis of CYR61 protein levels in U2OS and MG63 cells transfected with an miR-365 mimic with or without a pCDNA3.1-CYR61. *[right]* Fig 5A from [Lin et al (2017)] .  Western blot and analysis of AKT3 protein expression in TPC-1 and SW1736 cells expressing miR-217 or miR-217 plus AKT3 overexpression plasmid .  ,