Upregulation of microRNA-320 decreases the risk of developing steroid-induced avascular necrosis of femoral head by inhibiting CYP1A2 both in vivo and in vitro
Authors: Chun-Lan Huang
Qun-Qiang Luo
Ji-Xia Chen
Ji-Hua Wei
Qian-Li Tang
Yu-Jin Tang
Ding-Gui Lu
Journal: Gene (2018)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: CYP1A2; MicroRNA-320; Rat model; Steroid-induced avascular necrosis of femoral head.
Affiliations: Jinan University, Guangzhou 510632, PR China; Department of Orthopedics, the Affiliated Hospital of Youjiang Medical University for Nationality, Baise 533000, PR China., Department of Orthopedics, the Affiliated Hospital of Youjiang Medical University for Nationality, Baise 533000, PR China., Key Laboratory of High Incidence of Disease Prevention in the West of Guangxi, Youjiang Medical University for Nationality, Baise 533000, PR China. Electronic address: .

Abstract:  Steroid-induced avascular necrosis of femoral head (SANFH) occurs frequently in patients receiving high-dose steroid treatment for these underlying diseases. The target of this study is to investigate the effect of microRNA-320 (miR-320) on SANFH by targeting CYP1A2. CYP1A2 expression was detected using immunohistochemistry. Specimens were collected from patients with SANFH and femoral neck fracture. Seventy rats were assigned into seven groups. The targeting relationship between miR-320 and CYP1A2 was verified by bioinformatics website and dual luciferase reporter gene assay. RT-qPCR and Western blot analysis were used to detect miR-320 and CYP1A2 expressions. The enzymatic activity of CYP1A2 was detected by fluorescence spectrophotometry. Hemorheology and microcirculation were measured in rats. MiR-320 expression decreased and CYP1A2 expression and enzymatic activity increased in SANFH patients compared to those with femoral neck fracture. CYP1A2 was the target gene of miR-320. Hemorheology and microcirculation results showed that up-regulated expression of CYP1A2 promoted the development of SANFH while increased expression of miR-320 inhibited the development of SANFH. Compared with the SANFH group, the SANFH + miR-320 mimic group showed increased miRNA-320 expression, and decreased CYP1A2 expression and enzymatic activity. Opposite results were found in the SANFH + miR-320 inhibitor group. The SANFH + miR-320 inhibitor + pCR-CYP1A2_KO group showed decreased miRNA-320 expression and the SANFH + pCR-CYP1A2_KO group showed decreased CYP1A2 expression and enzymatic activity. Our findings provide evidences that miR-320 might inhibit the development of SANFH by targeting CYP1A2. 

Retracted: No

PubPeer comments:
 Fig 6.  Enhanced miR-320 led to decreased CYP1A2 protein expression and enzymatic activity in rat femoral head tissues. Panel A, CYP1A2 protein expression in rat femoral head tissues . One of these bands is presumably CYP1A2, and one is presumably a loading control, but there is nothing in the Legend or the text to identify it. ![file] The protein blobs in the upper band appear to belong to a restricted gamut of shapes, represented by numerous papers by otherwise-unrelated groups of authors. I prepared a montage: ![] , 
 #1 Dear Mrs. Mr. Hoya camphorifolia, I am **Ji-hua Wei**, **the first author** of the article on which you commented, titled  Upregulation of microRNA-320 decreases the risk of developing steroid-induced avascular necrosis of femoral head by inhibiting CYP1A2 both in vivo and in vitro . It is my honour having your attention on my work, and I must thank you for your professional and courtesy comments skeptismon this article. As for Fig. 6A, the western blot result, the upper panel should be labelled with the gene s name  CYP1A2 , the lower panel should be labelled with the house keeping gene  GAPDH . In this part, I sincerely appreciate your pinpoint out this inadverent clerical error exhisting in this article. Admittedly, it is very important for us, and for the readers,without question. For which, we have already prepared the material(s) for ongoing erratum. We are now contacting the journal (Gene) for this erratum. The new Fig. 6A with gene names labelled is attached as below. ![file] If there s any progress, we will post it here. Besides, the bands in the upper panel (bands for the expression of the gene CYP1A2), we compared the skeptical ones with the photos provided by you, we find they are merely similar, but are quite different ones, both in shape and spectrum, especially when you put them in a big high-resolutional screen. For which, we have prepared and attached our Fig.6A prepared from raw data, for comparison. At last, we thank you very much for your professional comments on our work. My institutional E-mail address is: jihua.wei@ymun.edu.cn. Yours, sincerely, Ji-Hua Wei ,