Dataset Information

Circular RNA HIPK2 regulates astrocyte activation via cooperation of autophagy and ER stress by targeting MIR124-2HG.

ABSTRACT: Circular RNAs are a subclass of noncoding RNAs in mammalian cells; however, whether these RNAs are involved in the regulation of astrocyte activation is largely unknown. Here, we have shown that the circular RNA HIPK2 (circHIPK2) functions as an endogenous microRNA-124 (MIR124-2HG) sponge to sequester MIR124-2HG and inhibit its activity, resulting in increased sigma non-opioid intracellular receptor 1 (SIGMAR1/OPRS1) expression. Knockdown of circHIPK2 expression significantly inhibited astrocyte activation via the regulation of autophagy and endoplasmic reticulum (ER) stress through the targeting of MIR124-2HG and SIGMAR1. These findings were confirmed in vivo in mouse models, as microinjection of a circHIPK2 siRNA lentivirus into mouse hippocampi inhibited astrocyte activation induced by methamphetamine or lipopolysaccharide (LPS). These findings provide novel insights regarding the specific contribution of circHIPK2 to astrocyte activation in the context of drug abuse as well as for the treatment of a broad range of neuroinflammatory disorders.

SUBMITTER: Huang R

PROVIDER: S-EPMC5640207 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Circular RNA HIPK2 regulates astrocyte activation via cooperation of autophagy and ER stress by targeting MIR124-2HG.

Huang Rongrong R Zhang Yuan Y Han Bing B Bai Ying Y Zhou Rongbin R Gan Guangming G Chao Jie J Hu Gang G Yao Honghong H

Autophagy 20170808 10

Circular RNAs are a subclass of noncoding RNAs in mammalian cells; however, whether these RNAs are involved in the regulation of astrocyte activation is largely unknown. Here, we have shown that the circular RNA HIPK2 (circHIPK2) functions as an endogenous microRNA-124 (MIR124-2HG) sponge to sequester MIR124-2HG and inhibit its activity, resulting in increased sigma non-opioid intracellular receptor 1 (SIGMAR1/OPRS1) expression. Knockdown of circHIPK2 expression significantly inhibited astrocyte ...[more]

PMID: 28786753

Similar Datasets

Project description:Circular RNAs (circRNAs) are highly expressed in the central nervous system and are involved in the regulation of physiological and pathophysiological processes. However, the potential role of circRNAs in stroke remains largely unknown. Here, using a circRNA microarray, we showed that circular RNA Hectd1 (circHectd1) levels were significantly increased in ischemic brain tissues in transient middle cerebral artery occlusion (tMCAO) mouse stroke models and further validated this finding in plasma samples from acute ischemic stroke (AIS) patients. Knockdown of circHectd1 expression significantly decreased infarct areas, attenuated neuronal deficits, and ameliorated astrocyte activation in tMCAO mice. Mechanistically, circHECTD1 functions as an endogenous MIR142 (microRNA 142) sponge to inhibit MIR142 activity, resulting in the inhibition of TIPARP (TCDD inducible poly[ADP-ribose] polymerase) expression with subsequent inhibition of astrocyte activation via macroautophagy/autophagy. Taken together, the results of our study indicate that circHECTD1 and its coupling mechanism are involved in cerebral ischemia, thus providing translational evidence that circHECTD1 can serve as a novel biomarker of and therapeutic target for stroke.Abbreviations3-MA: 3-methyladenine; ACTB: actin beta; AIS: acute ischemic stroke; AS: primary mouse astrocytes; BECN1: beclin 1, autophagy related; BMI: body mass index; circHECTD1: circRNA HECTD1; circRNAs: circular RNAs; CBF: cerebral blood flow; Con: control; DAPI: 4',6-diamidino-2-phenylindole; ECA: external carotid artery; FISH: fluorescence in situ hybridization; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; Gdna: genomic DNA; GFAP: glial fibrillary acidic protein; GO: gene ontology; HDL: high-density lipoprotein; IOD: integrated optical density; LDL: low-density lipoprotein; LPA: lipoprotein(a); MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MIR142: microRNA 142; mNSS: modified neurological severity scores; MRI: magnetic resonance imaging; NIHSS: National Institute of Health Stoke Scale; OGD-R: oxygen glucose deprivation-reperfusion; PCR: polymerase chain reaction; PFA: paraformaldehyde; SQSTM1: sequestosome 1; TIPARP: TCDD inducible poly(ADP-ribose) polymerase; tMCAO: transient middle cerebral artery occlusion; TTC: 2,3,5-triphenyltetrazolium chloride; UTR: untranslated region; WT: wild type.

Project description:The role of circular RNA in cancer is emerging. A newly reported circular RNA HIPK3 (circHIPK3) is critical in cell proliferation of various cancer types, although its role in non-small cell lung cancer (NSCLC), has yet to be elucidated. Our results provided evidence that silencing of circHIPK3 significantly impaired cell proliferation, migration, invasion and induced macroautophagy/autophagy. Mechanistically, we uncovered that autophagy was induced upon loss of circHIPK3 via the MIR124-3p-STAT3-PRKAA/AMPKa axis in STK11 mutant lung cancer cell lines (A549 and H838). STAT3 abrogation as well as transfection with a MIR124-3p mimic, recapitulated the induction of autophagy. We also demonstrated antagonistic regulation on autophagy between circHIPK3 and linear HIPK3 (linHIPK3). We therefore propose that the ratio between circHIPK3 and linHIPK3 (C:L ratio) may reflect autophagy levels in cancer cells. We observed that a high C:L ratio (>0.49) was an indicator of poor survival, especially in advanced-stage NSCLC patients. These results support that circHIPK3 is a key autophagy regulator in a subset of lung cancer and has potential clinical use as a prognostic factor. The circular RNA HIPK3 (circHIPK3) functions as an oncogene and autophagy regulator may potential use as a prognostic marker and therapeutic target in lung cancer.Abbreviations 3-MA: 3-methyladenine; AMPK: AMP-activated protein kinase; ATG7: autophagy related 7; Baf-A: bafilomycin A1; BECN1: beclin 1; circHIPK3: circular HIPK3; CQ: chloroquine; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; HIPK3: homeodomain interacting protein kinase 3; IL6R: interleukin 6 receptor; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; NSCLC: non-small cell lung cancer; RFP: red fluorescent protein; RPS6KB1/S6K: ribosomal protein S6 kinase B1; SQSTM1/p62: sequestosome 1; STAT3: signal transducer and activator of transcription 3; STK11: serine/threonine kinase 11.

Dataset Information

Circular RNA HIPK2 regulates astrocyte activation via cooperation of autophagy and ER stress by targeting MIR124-2HG.

Publications

Circular RNA HIPK2 regulates astrocyte activation via cooperation of autophagy and ER stress by targeting MIR124-2HG.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets