Overexpressed microRNA-494 represses RIPK1 to attenuate hippocampal neuron injury in epilepsy rats by inactivating the NF-κB signaling pathway
Authors: Yinbao Qi
Ruobing Qian
Dong Zhang
Xiaorui Fei
Yiming Zhang
Xianming Fu
Sen Jiang
Li Jia
Journal: Cell Cycle (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Epilepsy; MicroRNA-494; apoptosis; nuclear factor-kappaB signaling pathway; proliferation
Affiliations: Department of Nuerosurgery, Shandong University , Jinan, Shandong Province, P. R. China., Department of Neurosurgery, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China , Hefei, Anhui Province, P. R. China., Department of Neurosurgery, Anhui Provincial Institute of Stereotactic Neurosurgery , Hefei, Anhui Province, P. R. China., Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University , Hefei, Anhui Province, P. R. China.

Abstract:  Objective: The effects of microRNAs (miRNAs) have been identified in epilepsy (Ep) in recent years, our research was focused on the functions of miR-494 in Ep and its inner mechanisms. Methods: The Ep modeled rats induced by lithium chloride-pilocarpine were treated with agomir-miR-494 or RIPK1-siRNA. The pathology of rat hippocampal tissues was observed. Expression of miR-494, receptor-interacting protein kinase 1 (RIPK1) and nuclear factor-kappaB (NF-κB) p65 was assessed by RT-qPCR and Western blot analysis. The hippocampal neurons of epileptic rats were successfully modeled, which were transfected with miR-494 mimics or RIPK1-siRNA to determine neurons' proliferation ability and cell apoptosis. The target relation between miR-494 and RIPK1 was measured by bioinformatics website and dual luciferase gene reporter assay. Results: The expression of miR-494 was reduced, while the expression of RIPK1 and NF-κB p65 was amplified in hippocampus of Ep rats. Elevated miR-494 repressed the expression of RIPK1 to ameliorate the hippocampal neuron injury, accelerate neuronal proliferation, and restrain neuronal apoptosis via inactivating the NF-κB signaling pathway, causing a deceleration of Ep development. Furthermore, amplified RIPK1 was able to reverse the amelioration of neuronal injury in Ep rats which was contributed by upregulated miR-494. Conclusion: We found in this study that elevated miR-494 repressed RIPK1, causing an inactivation of the NF-κB signaling pathway and acceleration of cell proliferation, and suppression of apoptosis of hippocampal neurons in Ep rats, thereby attenuating the neuron injury and Ep development. Our research may provide novel targets for the therapy of Ep. 

Retracted: No

PubPeer comments:
  Figure 2. Elevated miR-494 and reduced RIPK1 repress hippocampal neuron injury in Ep rats. (A) representative images of HE staining (200 u00d7); (B) comparisons of neuronal ultrastructure of rats among the groups (7500 u00d7); (C) representative images of Nisslu2019s staining (200 u00d7) . ![file] The panels of Fig 2 reveal many causes of concern. Here is a panel of 2a, showing internal similarity after a 180-deg flip. ![file] The fourth and sixth panels of 2c, with some contrast enhancement to draw attention to the background: ![file] The second panel (horizontally flipped), third, fifth and seventh panels of 2c: ![file] I have marked some of the repeated motifs in panels 5 and 7, and left 2 and 3 as an exercise for the readers. Here with contrast enhancement: ![file] , 
  Therefore, more effective methods are needed to further restrain the progression of Ep. Epilepsy is not a progressive condition.  We would like to acknowledge the reviewers for their helpful comments on this paper. One can only imagine what Fig 2 was like before the reviewers suggested improvements. , 
 Thank you for your attention to our manuscript and helpful suggestions. Iu2019m writing to you in response to the inquiries you posted with regard to the study u201cOverexpressed microRNA-494 represses RIPK1 to attenuate hippocampal neuron injury in epilepsy rats by inactivating the NF-u03baB signaling pathwayu201d. Firstly, after carefully rechecking all the images again, we have figured out that this error was caused due to my negligence during the figure assembly as there were too many very similar figures. When we cropped the original images to collectively present the representative pictures, we accidentally inserted the wrong images into the different groups, leading to some overlap and similar pictures between and within groups. Besides, the problems mentioned in Figure 2 might also be resulted from a stutter of the imaging system. Secondly, epilepsy is not a progressive condition, we are very sorry for the improper use of language in the manuscript. Thirdly, when we say  We would like to acknowledge the reviewers for their helpful comments on this paper. , we meant that our deepest gratitude goes to the anonymous reviewers for their careful work and thoughtful suggestions that have helped improve this paper substantially. We sincerely apologize for this unintentional error and confirm that the mistake would not affect the conclusions of this study. At the same time, we have contacted the journal to correct the misused pictures. We greatly appreciate for your concern. , 
 #3 I understand that some accidental re-use of images could happen while assembling them into a panel. However, can you please explain how patterns could ever repeat themselves  within a single image? Let me copy one of the images from #1 to show what I m talking about. Pay attention to the image on the right. ![file] , 
 The Normal panel of Fig 1a has abnormalities. ![file] , 
 Previous comment should be  Fig 2a . The Ep panel of Fig 2a, and a 180-deg flipped version. Unexpected similarities. ![file] , 
 The right first panel of Fig 2a. The image was enhanced to reveal details. ![file] , 
 More fun with 180-deg flips. ![file] , 
 Fig 5A,  morphology of primary-cultured neurons in rat hippocampus under a light microscope . ![file] , 
 Concerns about Figure 3b. * Blue boxes: Two panels appear to overlap, with some stretching and rotation. * Green boxes: The same area - but not its surroundings - appears to be visible twice in two different panels ![file] ,