HDAC2 phosphorylation-dependent Klf5 deacetylation and RARŒ± acetylation induced by RAR agonist switch the transcription regulatory programs of p21 in VSMCs
Authors: Xin-Hua Zhang
Ya-Nan Shu
Mei Han
Hui-Jing Shi
Sui-Bing Miao
Ying-Jie Li
Bin Zheng
Tian Zhang
Jin-Kun Wen
Journal: Cell Research (2011)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Vascular smooth muscle cells; VSMCs; p21; retinoic acid receptor; RAR
Affiliations: Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China.

Abstract:  Abnormal proliferation of vascular smooth muscle cells (VSMCs) occurs in hypertension, atherosclerosis and restenosis after angioplasty, leading to pathophysiological vascular remodeling. As an important growth arrest gene, p21 plays critical roles in vascular remodeling. Regulation of p21 expression by retinoic acid receptor (RAR) and its ligand has important implications for control of pathological vascular remodeling. Nevertheless, the mechanism of RAR-mediated p21 expression in VSMCs remains poorly understood. Here, we show that, under basal conditions, RARŒ± forms a complex with histone deacetylase 2 (HDAC2) and Kr√ºppel-like factor 5 (Klf5) at the p21 promoter to inhibit its expression. Upon RARŒ± agonist stimulation, HDAC2 is phosphorylated by CK2Œ±. Phosphorylation of HDAC2, on the one hand, promotes its dissociation from RARŒ±, thus allowing the liganded-RARŒ± to interact with co-activators; on the other hand, it increases its interaction with Klf5, thus leading to deacetylation of Klf5. Deacetylation of Klf5 facilitates its dissociation from the p21 promoter, relieving its repressive effect on the p21 promoter. Interference with HDAC2 phosphorylation by either CK2Œ± knockdown or the use of phosphorylation-deficient mutant of HDAC2 prevents the dissociation of Klf5 from the p21 promoter and impairs RAR agonist-induced p21 activation. Our results reveal a novel mechanism involving a phosphorylation-deacetylation cascade that functions to remove the basal repression complex from the p21 promoter upon RAR agonist treatment, allowing for optimum agonist-induced p21 expression. 

Retracted: No

PubPeer comments:
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 Seven papers published by Wen Jinkun et al have data problemsuff0cincluding multi use of one image, cutting and splicing images, fictitious control blank data, and so on. All of them were journal papers with higher impact factors, such as Cell res (1), JBC (2), mol ther (1), CIRC res (1). The data of papers published in cell res (2011; 21 (10): 1487-508) were most seriously modified by the Main author. 1.tBy changing the brightness, width and width of the same picture and cropping the swim lanes, it can be reused in Figure1G, Figure3I and Figure5C. The marked cell types and processing conditions are completely different.  Legend: Figure 1 Guff1a293A cells were cotransfected with these p21 promoter-reporter constructs together with pMT-Klf5 and pCMV-RARu03b1u3002 Figure 3Iuff1aVSMCs were treated with or without Am80 (2 u00b5M) for 2 h, then crosslinked chromatin was extracted and immunoprecipitated with anti-RARu03b1 (upper panel) or anti-Klf5 (lower panel) antibodies with Am80-treated VSMCs. Figure 5Cuff1aVSMCs were pretreated with TSA for 1 h before exposure to Am80 for 2 h. The author used the same picture to present panels under three different experimental conditions: Figure1G, Figure3I, and Figure5C. Although the experimental groups were similar, the cell types and processing conditions marked by Legend were completely different. 2.tThe bottom of Figure3D is the same picture as the bottom of Figure3E on the right Just made a parallel inversion, but the content displayed is completely different.  The author explains: RARa and Klf5 s western blot background reference pictures are very similar, and the negligence caused the pictures to be confused. They interpreted the subjective behavior of  parallel reversal as  negligence . Even so, why is there no other original background picture that was confused, or data from repetitive experiments? Therefore, u201cThe results are from representative experiments that have been repeated 3 times with similar results.u201d claimed by Figure 3 Legend is obviously also false. 3. The above parallel inverted Figure3D and Figure3E are clipped and modified on both sides of the lane, and the fabricated data appears again in the two panels of Figure 2Au3002The processing conditions displayed by Legends are completely different.  Legendsuff1a Figure 2Auff1aInteraction between Klf5, RARu03b1 and HDAC2 was examined by co-immunoprecipitation (Co-IP) and western blot analysis with the indicated antibodies. Anti-Klf5 (left panel) or anti-RAR u03b1 (right panel) immunoprecipitates were analyzed by western blotting with anti-HDAC2, Klf5 and RARu03b1 antibodies. The text shows u201cunder basal conditionsu201duff01 Figure 3D-Euff1aVSMCs were treated with different concentrations of Am80. Cell extracts were immunoprecipitated either with anti-Klf5 antibody or with anti-RAR u03b1 anti-body and immunoblotted with antibodies against RAR u03b1, Klf5 and HDAC2u3002 The authors explained that the images they cut and spelled out were negative controls (so they drew a blank box), not the core data. , 
 Zheng Bin (the first author) recently sent to Cell Res an email saying u201cshe has found all of the original records in 2008 and applied for erratau00a0to replace the photosu201d, suggesting that all the original data of the Cell Res paper published in 2011 were completed in 2008. No data has been updated in the three-year time span.u00a0The manuscript revision time should be in 2010, do these data also come from 2008? It s unbelievable. Paradoxically, in her another email in December 2012, Zheng Bin stated u201cSome of the experimental results obtained by Shu Yanan (Klf4 and RAR) have been published in Cell Res (2011)u201d. The experimental records filed by Shu Yanan (the third author) clearly shows that this part of the results was finished in the period from March 2009 to April 2010, which coincided with the publication time of the paper. May I ask which of the two emails is true? Why do you refuse other authors to review your original data so faruff1f Zheng Bin s words are self-contradictory, together with most of the problem papers are from Zheng Bin in Wen s Labuff0cand she has refused to let other authors review her basic data so far. We were afraid her research integrity is questionable. ,