DNA methyltransferase 3b regulates nerve growth factor-induced differentiation of PC12 cells by recruiting histone deacetylase 2
Authors: Shoumei Bai
Kalpana Ghoshal
Samson T Jacob
Jharna Datta
Sung Ok Yoon
Sarmila Majumder
Journal: Molecular and Cellular Biology (2005)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Epigenetic reprogramming; DNA methyltransferases; NGF-induced differentiation; PC12 cells; Neuronal cells
Affiliations: Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University, Columbus, OH 43210, USA., Department
of Molecular and Cellular Biochemistry, College of
Medicine, Center for Molecular
Neurobiology, The Ohio State University, Columbus,
Ohio

Abstract:  To elucidate the role of epigenetic reprogramming in cell- or tissue-specific differentiation, we explored the role of DNA methyltransferases (Dnmts) in the nerve growth factor (NGF)-induced differentiation of PC12 (pheochromocytoma) cells into neuronal cells. The mRNA and protein levels of de novo methyltransferase Dnmt3b increased, whereas those of Dnmt3a and Dnmt1 decreased, during NGF-induced neurite outgrowth. Dnmt3b localized in the nucleus, as well as in the growing neurites. When the expression of Dnmt3b was inhibited by antisense or small interfering RNA, PC12 cells continued to proliferate and failed to generate neurites. Cells depleted of Dnmt3b were unable to exit the cell cycle even after 6 days of NGF treatment. Furthermore, this failure in differentiation correlated with significant attenuation in tyrosine phosphorylation of TrkA (a marker for NGF-induced differentiation) and reduced the expression of neuronal markers, Hu antigen, and MAP2. The methyl-CpG content of the PC12 genome or the methylation status of repetitive elements was not significantly altered after differentiation and was not affected by Dnmt3b depletion. This was consistent with the ability of the catalytic-site mutant of Dnmt3b to induce differentiation in Dnmt3b-depleted cells after NGF treatment. The Dnmt3b-mediated differentiation was attributed to its N-terminal domain, which recruits histone deacetylase 2 (Hdac2), as demonstrated by (i) impeding of differentiation by the Hdac inhibitors, (ii) facilitation of the differentiation process by overexpression of the N-terminal domain of Dnmt3b, (iii) higher Hdac activity associated with Dnmt3b after NGF treatment, and (iv) coimmunoprecipitation and cosedimentation of Dnmt3b specifically with Hdac2 in a glycerol density gradient. These data indicate a novel role of Dnmt3b in neuronal differentiation. 

Retracted: Yes

PubPeer comments:
 Figure 2(F)  Representative microscopy image of control and Dnmt3b antisense cell lines. ![file] Vector and Parental -NGF cell lines are the same. , 
 #3 Figure 8C is perhaps best approached band-by-band. Here s the Dnmt3b band. As peer2 noted, lanes 17-18 duplicate lanes 15-16. There is also a vertical glitch between the Input lane and the others. ![file] Dnmt3a band. As peer2 noted, there are two pairs of lane duplications. And what are all those blurry smeary marks in lanes 12 to 15? ![file] , 
 Figure 8C. Dnmt3b panel. Small details. ![file] , 
 The Hdac2 band is just a hot mess so I have shown it twice, in original form and with contrast enhanced. Vertical discontinuities around lane 1, and between lanes 7-8. Lane 4 appears to be a retouched copy of lane 3. All sorts of stuttering happening in lanes 15-18. ![file] , 
 #6 Possibly a fourth occurrence of the same small detail? ![file] , 
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 First author appears to currently be affiliated with University of Pittsburgh, and has the unfortunate distinction of appearing as coauthor of multiple papers with similar image concerns while at different institutions: https: pubpeer.com search?q=Shoumei+Bai ![file] , 
 12 April 2022 retraction. https: journals.asm.org doi 10.1128 mcb.00545-21 The Ohio State University (OSU) informed Molecular and Cellular Biology and ASM that following an investigation of research misconduct, they found u201cfalsified data in Figure 8Cu201d and u201cincorrect data includedu201d in Fig. 1D, 2D, 5, and 8A and B. Based on these findings and an unsatisfactory response from the authors, per ASM Publishing Ethics Policies and Procedures, we are abiding by the OSU retraction request. The integrity of the data presented was compromised; therefore, this publication is retracted in its entirety. We apologize to the readers of Molecular and Cellular Biology and regret any inconvenience that this causes. , 
 https: retractionwatch.com 2018 08 17 cancer-researcher-at-osu-up-to-nine-retractions ,