Cajanonic acid A regulates the ratio of Th17/Treg via inhibition of expression of IL-6 and TGF-Œ≤ in insulin-resistant HepG2 cells
Authors: Yanfeng Gong
Huanbing Liu
Liming Tao
Journal: Bioscience Reports (2019)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Cajanonic acid A; IL-6; TGF-Œ≤; Th17/Treg; insulin resistance.
Affiliations: Department of Geriatrics, The First Affiliated Hospital of Nanchang University, No. 17, Yongwai Zheng Street, Nanchang 330006, Jiangxi, China.

Abstract:  Background: The objectives of the present study are to investigate whether cajanonic acid A (CAA) can reduce insulin resistance (IR) in HepG2 cells and to gain a preliminary understanding of the mechanisms underlying this effect. Methods: Following induction of IR in HepG2 cells, we tested the regulatory effect of CAA on glucose consumption and evaluated hepatocyte production of IL-6, TGF-Œ≤, and key molecules in the insulin transduction pathway. A transwell co-culturing system was used to assess the effect of CAA on IR in HepG2 cells during the differentiation of CD4+ T cells by calculating the ratio of (Th17)/regulatory T cell (Treg). We evaluated the effect of CAA on the expression of IL-17RC cells and HepG2 cell apoptosis by immunofluorescence and flow cytometry assay. Results: CAA improved dexamethasone-induced reduction in glucose consumption in HepG2 cells, inhibited hepatocyte production of IL-6 and TGF-Œ≤, increased the expression of IL-17RC cell, and increased cellular apoptosis in insulin-resistant HepG2 cells. When co-cultured with CD4+ T cells, insulin-resistant HepG2 cells induced a decrease in the ratio of Th17/Treg, but CAA dampened the effect. Application of IL-6 and TGF-Œ≤, together with CAA, reversed the effect of CAA on insulin-resistant HepG2 cells. Overexpression of IL17R, however, counteracted the effect of IL-6 neutralizing antibody within the culture system. Conclusion: CAA can regulate the ratio of Th17/Treg by mediating the expression of IL-6 and TGF-Œ≤ in insulin-resistant HepG2 cells. 

Retracted: No

PubPeer comments:
 Two plots in figure 3 appear to include an unexpectedly large number of identically placed data points, including several that fall outside the plot area (green arrows). Magenta arrow marks another occasion of the latter issue. Can the authors explain? *** Closeup  *** Full figure  , 
 EXPRESSION OF CONCERN| FEBRUARY 17 2021 The Editorial Office has been made aware of potential issues surrounding the scientific validity of this paper, hence has issued an expression of concern to notify readers whilst the Editorial Office investigates. , 
 Retraction January 20, 2022  This Retraction follows an Expression of Concern relating to this article previously published by Portland Press. This article is being retracted from Bioscience Reports at the request of the Editor-in-Chief and the Editorial following receipt of a notification from a reader, alerting the Editorial Board to multiple duplicate data points in the images from Figure 3A. Upon further examination by the Editorial Office, additional clusters of duplicated data points were also noted in in Figure 3F and 4C. The authors have been contacted in regards to the retraction, and were unable to provide the Editorial Office with the original data which they stated was obtained using equipment from another laboratory, which can no longer be accessed retrieved due to equipment issues. Given the extent of the issues raised, the Editorial Board stand by the decision to retract the article. The authors agree to the Retraction. ,