RETRACTED ARTICLE: Epigallocatechin-3-gallate (EGCG) as a pro-osteogenic agent to enhance osteogenic differentiation of mesenchymal stem cells from human bone marrow: an in vitro study
Authors: Pan Jin
Huayu Wu
Jinmin Zhao
Li Zheng
Guojie Xu
Journal: Cell and Tissue Research (2014)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Mesenchymal stem cells; Osteogenic capacity; (-)-Epigallocatechin-3-gallate (EGCG); Osteoporosis; Osteoblasts
Affiliations: Department of Orthopaedic Trauma and Hand Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, 530021, China.

Abstract:  The proliferation and osteogenic capacity of mesenchymal stem cells (MSCs) needs to be improved for their use in cell-based therapy for osteoporosis. (-)-Epigallocatechin-3-gallate (EGCG), one of the green tea catechins, has been widely investigated in studies of osteoblasts and osteoclasts. However, no consensus on its role as an osteogenic inducer has been reached, possibly because of the various types of cell lines examined and the range of concentrations of EGCG used. In this study, the osteogenic effects of EGCG are studied in primary human bone-marrow-derived MSCs (hBMSCs) by detecting cell proliferation, alkaline phosphatase (ALP) activity and the expression of relevant osteogenic markers. Our results show that EGCG has a strong stimulatory effect on hBMSCs developing towards the osteogenic lineage, especially at a concentration of 5 μM, as evidenced by an increased ALP activity, the up-regulated expression of osteogenic genes and the formation of bone-like nodules. Further exploration has indicated that EGCG directes osteogenic differentiation via the continuous up-regulation of Runx2. The underlying mechanism might involve EGCG affects on osteogenic differentiation through the modulation of bone morphogenetic protein-2 expression. EGCG has also been found to promote the proliferation of hBMSCs in a dose-dependent manner. This might be associated with its antioxidative effect leading to favorable amounts of reactive oxygen species in the cellular environment. Our study thus indicates that EGCG can be used as a pro-osteogenic agent for the stem-cell-based therapy of osteoporosis. 

Retracted: Yes

PubPeer comments:
 Figure 2: Two cases where microscopy data has been duplicated and presented as something else (b vs e and k vs m). Figure 5: Just a few examples are shown. Figure 6: Just a few examples are shown. ![file] ![file] ![file] , 
 Figure 3 is really impressive. Just panel (a) here: ![file] , 
 #1 The replication (or overlap) of panels within Fig 2 is understandable, given the amount of effort that must have gone into their construction. ![file] , 
 2(c). Wouldn t it have been easier just to conduct an experiment? ![file] , 
 Retracted [14 December 2020] . ----------------------------------------- The Editor-in-Chief has retracted this article [1] because there appear to be numerous duplications within Figs. 2, 3, 5 and 6. Due to these duplications, the Editor-in-Chief no longer has confidence in the data and subsequent conclusions drawn from them. Huayu Wu agrees to this retraction. Li Zheng agrees with the retraction but does not does not agree with the wording. Pan Jin does not agree with the retraction. Guojie Xu and Jinmin Zhao have not responded to any correspondence from the publisher about this retraction. , 
 #5 It would be interesting to hear the first authoru2019s explanation. It seems they have multiple papers with problems. ,