Inhibition of HMGB1-induced angiogenesis by cilostazol via SIRT1 activation in synovial fibroblasts from rheumatoid arthritis
Authors: Sung Won Lee
Ki Whan Hong
So Youn Park
Won Suk Lee
Hye Rin Lee
Hye Young Kim
Byung Yong Rhim
Chi Dae Kim
Journal: PLoS ONE (2014)
Discipline: Multidisciplinary
Keywords: HMGB-1; cilostazol; arthritis; angiogenesis; HIF-1Œ±
Affiliations: Medical Research Center for Ischemic Tissue Regeneration, Pusan National University, Yangsan, Gyeongnam, Republic of Korea., Department of Internal Medicine, College of Medicine, Dong-A University, Busan, Republic of Korea., Medical Research Center for Ischemic Tissue Regeneration, Pusan National University, Yangsan, Gyeongnam, Republic of Korea; Department of Pharmacology, School of Medicine, Pusan National University, Yangsan, Gyeongnam, Republic of Korea., Department of Pharmacology, School of Medicine, Pusan National University, Yangsan, Gyeongnam, Republic of Korea.

Abstract:  High mobility group box chromosomal protein 1 (HMGB-1) released from injured cells plays an important role in the development of arthritis. This study investigated the anti-angiogenic effects of cilostazol in collagen-induced arthritis (CIA) of mice, and the underlying mechanisms involved. The expressions of HIF-1Œ±, VEGF, NF-Œ∫B p65 and SIRT1 in synovial fibroblasts obtained from rheumatoid arthritis (RA) patients were assessed by Western blotting, and in vitro and in vivo angiogenesis were analyzed. Tube formations by human microvascular endothelial cells (HMVECs) were significantly increased by direct exposure to HMGB1 or to conditioned medium derived from HMGB1-stimulated RA fibroblasts, and these increases were attenuated by cilostazol, the latter of which was blocked by sirtinol. HMGB1 increased the expression of HIF-1Œ± and VEGF and concomitantly increased nuclear NF-Œ∫B p65 and DNA binding activity, but these effects of HMGB1 were inhibited by cilostazol. SIRT1 protein expression was time-dependently decreased (3-24 hr) by HMGB1, which was recovered by pretreatment with cilostazol (1-30 ¬µM) or resveratrol, accompanying with increased SIRT1 deacetylase activity. In the tibiotarsal joint tissues of CIA mice treated with vehicle, HIF-1Œ±- and VEGF-positive spots and CD31 staining were markedly exaggerated, whereas SIRT1 immunofluorescence was diminished. These variables were wholly reversed in cilostazol (30 mg/kg/day)-treated mice. Furthermore, number of blood vessels stained by von Willebrand factor antibody was significantly lower in cilostazol-treated CIA mice. Summarizing, cilostazol activated SIRT1 and inhibited NF-Œ∫B-mediated transcription, thereby suppressing the expression of HIF-1Œ± and VEGF. In addition, cilostazol caused HIF-1Œ± deacetylation by enhancing SIRT1 activity and reduced VEGF production, thereby had an anti-angiogenic effect in vitro studies and in CIA murine model. 

Retracted: Yes

PubPeer comments:
 19 March 2020 retraction. https: journals.plos.org plosone article?id=10.1371 journal.pone.0230889 Following publication of this article [1], concerns were raised about western blot images in Figs 3D, 4B, and 4E. Specifically, - In Fig 3D, there is an appearance of vertical discontinuities on either side of lane 4 in the VEGF panel; the u03b2-Actin panel is a duplicate of lanes 1u20135 of the u03b2-Actin panel in Fig 4B. - In Fig 4B and 4E, the u03b2-Actin panels were included as a result of an error in figure assembly. u03b2-Actin is a cytosolic protein, and was not measured in these experiments because NF-u03baB translocation was measured in nuclear extracts, and results were expressed relative to control untreated cells. The authors retract this article as it is not possible to fully resolve the concerns regarding Fig 3D because the majority of the underlying data for the article is unavailable. HYK, SYP, SWL, HRL, WSL, BYR, CDK agreed with the retraction. KWH either could not be reached or did not reply directly. Reference 1.Kim HY, Park SY, Lee SW, Lee HR, Lee WS, Rhim BY, et al. (2014) Inhibition of HMGB1-Induced Angiogenesis by Cilostazol via SIRT1 Activation in Synovial Fibroblasts from Rheumatoid Arthritis. PLoS ONE 9(8): e104743. https: doi.org 10.1371 journal.pone.0104743 pmid:25126750 , 
 Here is an illustration of the similarity between the Actin panels of Figure 3D and 4B, marked with red boxes, as reported in October 2015.  ,