Retracted : Magnesium protects mouse hippocampal HT22 cells against hypoxia‐induced injury by upregulation of miR‐221
Authors: Fuyu Liu
Fuli Mi
Chuanzhu Zhang
Journal: Journal of Cellular Biochemistry (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: NGF; hypoxia-induced injury; miR-221; neuroprotection.
Affiliations: Department of Gastrointestinal Endoscopy Center, Shandong Provincial Qianfoshan Hospital The First Hospital Affiliated with Shandong First Medical University  Jinan Shandong China, Department of Anesthesiology Linyi People's Hospital  Linyi Shandong China

Abstract:  Magnesium (Mg2+ ) has been shown to exert neuroprotective effects against hypoxia. However, it still remains elusive whether Mg2+ protected mouse hippocampal HT22 cells against hypoxia-evoked damages. Therefore, we aimed to investigate the function of Mg2+ and mechanisms associated with microRNA-221 (miR-221). HT22 cells were exposed to 3% O2 for 24 hours to induce hypoxic damages with 21% as a normoxic culture condition. The damages were monitored by viability, migration, and apoptosis of HT22 cells with or without Mg2+ pretreatment. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to examine the alteration of miR-221, miR-210, and miR-17-5p. Transduction was carried out to artificially alter the expression of miR-221 and nerve growth factor (NGF), which was confirmed by qRT-PCR or Western blot assays. To blunt phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and nuclear factor κB (NF-κB), LY294002 (10 µM) and BAY 11-7082 (10 µM) were used. We observed Mg2+ protected HT22 cells against hypoxia-induced damages by upregulating miR-221. Further, miR-221 positively regulated NGF expression. Overexpression of NGF alleviated cell injury, while suppression of NGF aggravated cell injury. Moreover, miR-221 elevated NGF by inducing phosphorylation of regulators in PI3K/AKT and NF-κB transduction cascades and then alleviated cell injury. In conclusion, Mg2+ protected HT22 cells against hypoxia-induced damages by upregulation of miR-221 and NGF. These findings provided insights into the development of improved strategies for clinical application. 

Retracted: Yes

PubPeer comments:
 The Western blots in this paper have an interesting appearance that appears to be shared with blots in other papers from other research groups, such as these papers published in the Journal of Cellular Biochemistry: * Ying Liu et al. 2019, DOI: 10.1002 jcb.29568 * Long Liu et al. 2020, DOI: 10.1002 jcb.29642 * Lin Zhang et al. 2019, DOI: 10.1002 jcb.28729 * Yugeng Li et al. 2019, DOI: 10.1002 jcb.29146 * Xiaoliang Yang et al. 2019, DOI: 10.1002 jcb.28829 * Ning Han et al. 2019, DOI: 10.1002 jcb.29638 All these papers share particular characteristics, such as similar title structure, similar graph design, and the appearance of the Western blots. Western blot panels within the same figure, and across figures and papers, appear to share the same background or parts of the background. In addition, the bands are regularly spaced, all have similar rounded edges, without the usual smudges and specks. The bands also sometimes have a particular fish-like shape that resembles jumping sardines. For example, here is Figure 1C. Although the bands are differently shaped, the background of these panels is much more similar than expected. Colored boxes draw attention to a subset of background areas that look unexpectedly similar. ![file] , 
 Figure 2C has three lane panels instead of two-lane panels. The left side of the blots appear to be showing the same shared background patterns as in Figure 1C (shown in blue and green boxes), while the right hand area shows a different set of similarities (shown in orange). ![file] , 
 Figure 3H panels appear to have a different shared background, while Figure 3L panels share some of the background patterns with Figures 1C and 2C. As with the previous comments, the colored panels are drawing attention to some of these shared patterns, without trying to be complete. ![file] , 
 Figure 5D, a 6-laner, shares background similarities with the 4 panel 3L (blue, green, and yellow boxes) as well as displaying another shared similarity on the right hand side. The reader can bring out their own colored pencils to color this one, as well as other Western blot panels not yet discussed. ![file] , 
 This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels. Despite these similarities, these papers are authored by researchers from different departments and institutes, with almost no overlap in authors. The list of these papers is available here: https: docs.google.com spreadsheets d 1KXqTAyl4j-jVorFPMD2XRpr76LcIKJ0CVyIvRj0exYQ edit?usp=sharing A more detailed description of this set of papers, suspected to all be generated by a common source, a paper mill , can be found here: * https: forbetterscience.com 2020 01 24 the-full-service-paper-mill-and-its-chinese-customers (January 2020) * https: scienceintegritydigest.com 2020 02 21 the-tadpole-paper-mill (February 2020) The same paper mill has been described in these papers: * Jana Christopher - Systematic fabrication of scientific images revealed - FEBS Letters (2018) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13201 * Jennifer A Byrne and Jana Christopher - Digital magic, or the dark arts of the 21st centuryu2014how can journals and peer reviewers detect manuscripts and publications from paper mills? - FEBS Letters (2020) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13747 , 
 Retracted [29 December 2020] .  u2018Magnesium protects mouse hippocampal HT22 cells against hypoxiau2010induced injury by upregulation of miRu2010221u2019, by Fuli Mi, Fuyu Liu, Chuanzhu Zhang, Cell Biochem. 2020; 1452u20101462: The above article, published online on 12 September 2019 in Wiley Online Library , has been retracted by agreement between the journal s Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. Several flaws and inconsistencies between results presented and experimental methods described were found, the editors consider the conclusions of this article to be invalid. The authors collaborated in the investigation initially, but were not available for a final confirmation of the retraction. ,