Abstract
Circular RNAs (circRNAs) have key roles in a variety of neurological diseases, including epilepsy. This objective of this study was to perform the functional exploration and mechanism investigation of circRNA Ubiquilin1 (circUBQLN1) in epilepsy. Epilepsy cell model was established by the treatment of Mg2+-free in human neurons-hippocampal (HN-h) cells. The quantitative real-time polymerase chain reaction (qRT-PCR) was used for the expression analysis of circUBQLN1, linear-UBQLN1, microRNA-155 (miR-155), and sex-determining region Y-box 7 (SOX7). Proliferation detection was completed using Cell Counting Kit-8 (CCK-8) assay. Apoptosis analysis was conducted by flow cytometry and caspase-3 assay. Oxidative stress was assessed through determining the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Target analysis was performed by dual-luciferase reporter and RNA pull-down assays. SOX7 protein level was examined by Western blot. CircUBQLN1 was downregulated in epilepsy samples and Mg2+-free-induced cell model. Functional analysis in vitro suggested that circUBQLN1 overexpression facilitated proliferation but reduced apoptosis and oxidative stress in Mg2+-free-treated HN-h cells. Target analysis showed that circUBQLN1 acted as a miR-155 sponge and miR-155-targeted SOX7. Moreover, circUBQLN1 could combine with miR-155 to regulate the SOX7 expression. Reverted assays indicated that circUBQLN1 overexpression alleviated the Mg2+-free-induced nerve injury by sponging miR-155, and knockdown of SOX7 abrogated the protective function of in-miR-155 or circUBQLN1 in the Mg2+-free-treated HN-h cells. Our data revealed that circUBQLN1 prevented nerve injury in Mg2+-free-treated HN-h cells by regulating the miR-155/SOX7 axis, showing that circUBQLN1 might be used as a biomolecular target for the treatment of epilepsy.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Data Availability
All data generated or analyzed during this study are included in this published article.
References
Krishnamurthy KB (2016) Epilepsy, Ann Intern Med 164(3):ITC17–32
Howard MA, Baraban SC (2017) Catastrophic epilepsies of childhood. Annu Rev Neurosci 40:149–166
Thijs RD, Surges R, O’Brien TJ, Sander JW (2019) Epilepsy in adults. Lancet 393(10172):689–701
Sen A, Jette N, Husain M, Sander JW (2020) Epilepsy in older people. Lancet 395(10225):735–748
Mbizvo GK, Bennett K, Simpson CR, Duncan SE, Chin RFM (2019) Epilepsy-related and other causes of mortality in people with epilepsy: a systematic review of systematic reviews. Epilepsy Res 157:106192
Pitkanen A, Henshall DC, Cross JH, Guerrini R, Jozwiak S, Kokaia M, Simonato M, Sisodiya S, Mifsud J (2019) Advancing research toward faster diagnosis, better treatment, and end of stigma in epilepsy. Epilepsia 60(7):1281–1292
Ellis CA, Petrovski S, Berkovic SF (2020) Epilepsy genetics: clinical impacts and biological insights. Lancet Neurol 19(1):93–100
Shao Y, Chen Y (2017) Pathophysiology and clinical utility of non-coding RNAs in epilepsy. Front Mol Neurosci 10:249
Ebbesen KK, Hansen TB, Kjems J (2017) Insights into circular RNA biology. RNA Biol 14(8):1035–1045
Henshall DC, Hamer HM, Pasterkamp RJ, Goldstein DB, Kjems J, Prehn JHM, Schorge S, Lamottke K, Rosenow F (2016) MicroRNAs in epilepsy: pathophysiology and clinical utility. Lancet Neurol 15(13):1368–1376
Lee WJ, Moon J, Jeon D, Kim TJ, Yoo JS, Park DK, Lee ST, Jung KH, Park KI, Jung KY, Kim M, Lee SK, Chu K (2018) Possible epigenetic regulatory effect of dysregulated circular RNAs in epilepsy. PLoS ONE 13(12):e0209829
Li J, Lin H, Sun Z, Kong G, Yan X, Wang Y, Wang X, Wen Y, Liu X, Zheng H, Jia M, Shi Z, Xu R, Yang S, Yuan F (2018) High-Throughput data of circular RNA profiles in human temporal cortex tissue reveals novel insights into temporal lobe epilepsy. Cell Physiol Biochem 45(2):677–691
Gong GH, An FM, Wang Y, Bian M, Wang D, Wei CX (2018) Comprehensive circular RNA profiling reveals the regulatory role of the CircRNA-0067835/miR-155 pathway in temporal lobe epilepsy. Cell Physiol Biochem 51(3):1399–1409
Li X, Giri V, Cui Y, Yin M, Xian Z, Li J (2019) LncRNA FTX inhibits hippocampal neuron apoptosis by regulating miR-21-5p/SOX7 axis in a rat model of temporal lobe epilepsy. Biochem Biophys Res Commun 512(1):79–86
Sombati S, Delorenzo RJ (1995) Recurrent spontaneous seizure activity in hippocampal neuronal networks in culture. J Neurophysiol 73(4):1706–1711
Wang XM, Jia RH, Wei D, Cui WY, Jiang W (2014) MiR-134 blockade prevents status epilepticus like-activity and is neuroprotective in cultured hippocampal neurons. Neurosci Lett 572:20–25
Li Y, Wang C, Lian Y, Zhang H, Meng X, Yu M, Li Y, Xie N (2020) Role of the mitochondrial calcium uniporter in Mg(2+)-free-induced epileptic hippocampal neuronal apoptosis, Int J Neurosci 1–9
Liu Y, Yang C, Cao C, Li Q, Jin X, Shi H (2020) Hsa_circ_RNA_0011780 represses the proliferation and metastasis of non-small cell lung cancer by decreasing FBXW7 via targeting miR-544a. Onco Targets Ther 13:745–755
Li Y, Song J, Xie Z, Liu M, Sun K (2020) Long noncoding RNA colorectal neoplasia differentially expressed alleviates sepsis-induced liver injury via regulating miR-126-5p. IUBMB Life 72(3):440–451
Bi J, Liu H, Cai Z, Dong W, Jiang N, Yang M, Huang J, Lin T (2018) Circ-BPTF promotes bladder cancer progression and recurrence through the miR-31-5p/RAB27A axis. Aging (Albany NY) 10(8):1964–1976
Salzman J, Gawad C, Wang PL, Lacayo N, Brown PO (2012) Circular RNAs are the predominant transcript isoform from hundreds of human genes in diverse cell types. PLoS ONE 7(2):e30733
Qu X, Li Z, Chen J, Hou L (2020) The emerging roles of circular RNAs in CNS injuries. J Neurosci Res
D'Ambra E, Capauto D, Morlando M (2019) Exploring the Regulatory Role of Circular RNAs in Neurodegenerative Disorders. Int J Mol Sci 20(21)
Wang G, Han B, Shen L, Wu S, Yang L, Liao J, Wu F, Li M, Leng S, Zang F, Zhang Y, Bai Y, Mao Y, Chen B, Yao H (2020) Silencing of circular RNA HIPK2 in neural stem cells enhances functional recovery following ischaemic stroke. EBioMedicine 52:102660
Yang Y, Gao X, Zhang M, Yan S, Sun C, Xiao F, Huang N, Yang X, Zhao K, Zhou H, Huang S, Xie B, Zhang N (2018) Novel Role of FBXW7 Circular RNA in Repressing Glioma Tumorigenesis. J Natl Cancer Inst 110(3)
Kumar L, Shamsuzzama, Jadiya P, Haque R, Shukla S, Nazir A (2018) Functional Characterization of Novel Circular RNA Molecule, circzip-2 and Its Synthesizing Gene zip-2 in C. elegans Model of Parkinson's Disease. Mol Neurobiol 55(8):6914–6926
Dube U, Del-Aguila JL, Li Z, Budde JP, Jiang S, Hsu S, Ibanez L, Fernandez MV, Farias F, Norton J, Gentsch J, Wang F, Dominantly Inherited Alzheimer N, Salloway S, Masters CL, Lee JH, Graff-Radford NR, Chhatwal JP, Bateman RJ, Morris JC, Karch CM, Harari O, Cruchaga C (2019) An atlas of cortical circular RNA expression in Alzheimer disease brains demonstrates clinical and pathological associations. Nat Neurosci 22(11):1903–1912
Yu Q, Zhao MW, Yang P (2020) LncRNA UCA1 suppresses the inflammation via modulating miR-203-mediated regulation of MEF2C/NF-kappaB signaling pathway in epilepsy. Neurochem Res 45(4):783–795
Zhu H, Xu H, Ma H, Luo L, Yang L, Chen F, Qu X, Liu H, Zhang R (2020) LncRNA CASC2 inhibits astrocytic activation and adenosine metabolism by regulating PTEN in pentylenetetrazol-induced epilepsy model. J Chem Neuroanat 105:101749
Panda AC (2018) Circular RNAs act as miRNA sponges. Adv Exp Med Biol 1087:67–79
Hu W, Han Q, Zhao L, Wang L (2019) Circular RNA circRNA_15698 aggravates the extracellular matrix of diabetic nephropathy mesangial cells via miR-185/TGF-beta1. J Cell Physiol 234(2):1469–1476
Zhu F, Cheng C, Qin H, Wang H, Yu H (2020) A novel circular RNA circENTPD7 contributes to glioblastoma progression by targeting ROS1. Cancer Cell Int 20:118
Author information
Authors and Affiliations
Contributions
Zhujun Zhu conceived and designed the experiments; Sihong Wang performed the experiments, funding acquisition; Qishi Cao contributed reagents/materials/analysis tools; Gang Li wrote the paper. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Ethical Approval
This study was approved by the Ethical Committee of the First People’s Hospital of Jintan District and the written informed consent from has been signed by each patient involved in this study.
Inform Consent
Informed consent was obtained from all patients.
Competing Interests
The authors declare no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Highlights
1. CircUBQLN1 enhances proliferation while represses apoptosis and oxidative stress in epilepsy cell model
2. CircUBQLN1 functions as a miR-155 sponge and SOX7 is a target for miR-155
3. CircUBQLN1 directly binds to miR-155 to regulate SOX7 expression
Supplementary Information
Below is the link to the electronic supplementary material.
12031_2021_1838_MOESM1_ESM.tif
Supplementary file1 (TIF 2087 KB) Fig. S1 Inhibition of SOX7 prevented the rescue of circUBQLN1 in Mg2+-free-treated HN-h cells. Mg2+-free-treated HN-h cells were transfected with pcDNA, circUBQLN1, circUBQLN1 + si-con or circUBQLN1 + si-SOX7. (A) Western blot was performed for the SOX7 protein quantification. (B) Cell proliferation was detected using CCK-8 assay. (C-D) Cell apoptosis was assessed using flow cytometry (C) and caspase3 activity assay (D). (E–F) Oxidative stress was analyzed using SOD and MDA levels. *P < 0.05, **P < 0.01, ***P < 0.001
Rights and permissions
About this article
Cite this article
Zhu, Z., Wang, S., Cao, Q. et al. CircUBQLN1 Promotes Proliferation but Inhibits Apoptosis and Oxidative Stress of Hippocampal Neurons in Epilepsy via the miR-155-Mediated SOX7 Upregulation. J Mol Neurosci 71, 1933–1943 (2021). https://doi.org/10.1007/s12031-021-01838-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12031-021-01838-2