Green tea polyphenols protect PC12 cells against H2O2-induced damages by upregulating lncRNA MALAT1
Authors: Guisheng Yu
Guohua Song
Qingguo Zhang
Shuheng Liu
Journal: International Journal of Immunopathology and Pharmacology (2019)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: MALAT1; PI3K/AKT; Wnt/β-catenin; green tea polyphenols; spinal cord injury.
Affiliations: 1 Department of Spine Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, China., 2 Department of Orthopaedics, Heze Municipal Hospital, Heze, China.

Abstract:  It is of significance to alleviate oxidative damages for the treatment of spinal cord injury (SCI). Studies have ascertained that green tea polyphenols (GTPs) exert protective activities against oxidative damages. In this study, we aimed to investigate the protective effects of GTP against H2O2-caused injuries in PC12 cells as well as the molecular underpinnings associated with long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). PC12 cells were preincubated with GTP prior to H2O2 stimulation. Furthermore, MALAT1-deficient PC12 cells were constructed by transfection and identified by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Next, viability and apoptosis were detected by cell counting kit-8 and flow cytometry, respectively. Meanwhile, Western blot assay was carried out to monitor the expression alteration of proteins associated with apoptosis (Bcl-2, Bax, pro-Caspase-3/9, and cleaved Caspase-3/9) and autophagy (microtubule-associated protein 1 light chain 3 (LC3)-II, LC3-I, Beclin-1, and p62). Moreover, we examined the expression of β-catenin and dissected the phosphorylation of phosphatidylinositol 3'-kinase (PI3K) and protein kinase B (AKT). We found that H2O2 decreased the viability of PC12 cells while initiated apoptosis and autophagy processes. GTP-preincubated PC12 cells maintained the viability and resisted the apoptosis and autophagy induced by H2O2. Pointedly, GTP-pretreated PC12 cells showed an increase in MALAT1 after H2O2 stimulation. Of note, the protective effects of GTP were buffered in MALAT1-deficient cells in response to H2O2. The expression of β-catenin and phosphorylation of PI3K and AKT were upregulated by GTP, while MALAT1 knockdown led to opposite results. To sum up, GTP protected PC12 cells from H2O2-induced damages by the upregulation of MALAT1. This process might be through activating Wnt/β-catenin and PI3K/AKT signal pathways. 

Retracted: No

PubPeer comments:
 The Western blots and other figures in this paper have an interesting layout that appears to be shared with many other papers, as discussed in a January 2020 post on Leonid Schneider s blog: https: forbetterscience.com 2020 01 24 the-full-service-paper-mill-and-its-chinese-customers The list of these papers is available here: https: docs.google.com spreadsheets d 1KXqTAyl4j-jVorFPMD2XRpr76LcIKJ0CVyIvRj0exYQ edit?usp=sharing In almost all papers, Western blot panels within the same figure, and across figures and papers, appear to share the same background, while the bands are regularly spaced, all have similar rounded edges without the usual smudges and specks, and with some bands showing a recognizable  jumping sardine shape. Also in almost all papers, bar graphs show a characteristic layout with bars in solid shades of grey, and the left-most bar in black, as well as double-edged error bars. Many papers have  cell viability and  apoptotic cells graphs. To illustrate the recognizable layout of the graphs in this paper, here is Figure 1. ![file] , 
 February 2021 Expression of Concern found here: https: journals.sagepub.com doi full 10.1177 20587384211000802 From the Notice:  *It has been brought to SAGEu2019s attention that this article may have been written (and possibly submitted) by a third-party agency, and that the contents of the article may be partially or wholly fabricated. SAGE is currently conducting a thorough investigation into this to establish the most appropriate way forward.* , 
 Retracted [2 September 2021] . H t [RetractionWatch] . ------------------------- At the request of the Journal Editor(s) the following article has been retracted. Liu S, Yu G, Song G, Zhang Q (2019) Green tea polyphenols protect PC12 cells against H2O2-induced damages by upregulating lncRNA MALAT1. International Journal of Immunopathology and Pharmacology 33: 1-10. DOI: 10.1177 2058738419872624. Significant similarities between this paper and a number of other papers have been identified, as well as indication of image and data manipulation suggestive of the use of a u201cpaper millu201d. These papers share common structures and wording yet do not share any common authors. The authors did not provide a sufficient response or evidence to refute these claims. As a result, the scientific accuracy of this paper is not reliable. Adhering to the international guidelines established by the Committee on Publication Ethics, the Journal has determined these are grounds for retraction. ,