Elsevier

World Neurosurgery

Volume 115, July 2018, Pages e570-e579
World Neurosurgery

Original Article
Deep Sequencing of Small RNAs in Blood of Patients with Brain Arteriovenous Malformations

https://doi.org/10.1016/j.wneu.2018.04.097Get rights and content

Highlights

  • We obtained the global miRNA expression profile in peripheral blood samples from BAVMs.

  • Mitogen-activated protein kinase, Wnt, and VEGF signaling were involved in the process of BAVMs.

  • miR-7-5p, miR-199a-5p, and miR-200b-3p may be potential diagnostic biomarkers of BAVMs.

Background

Deregulation of circulating microRNAs (miRNAs) is always associated with development and progression of human diseases. We aimed to assess whether patients with brain arteriovenous malformations (BAVMs) possess a distinct miRNA signature compared with healthy subjects.

Methods

Three patients with unruptured BAVMs and 3 normal control subjects were recruited as case and control groups. Peripheral blood was collected, and miRNA signature was obtained by next-generation sequencing, followed by comparative, functional, and network analyses. Quantitative reverse transcription polymerase chain reaction was performed to validate expression of specific miRNAs.

Results

Deep sequencing detected 246 differentially expressed miRNAs in blood samples of patients with BAVMs compared with normal control subjects. For the top 5 miRNAs, 946 target genes were predicted, and a BAVM-specific miRNA-target gene regulatory network was constructed. Functional annotation suggested that 15 of the predicted miRNA-targeted genes were involved in vascular endothelial growth factor signaling, in which 3 critical miRNAs were involved: miR-7-5p, miR-199a-5p, and miR-200b-3p.

Conclusions

We explored the miRNA expression signature of BAVMs, which will provide an important foundation for future studies on the regulation of miRNAs involved in BAVMs.

Introduction

Brain arteriovenous malformations (BAVMs) are major causes of intracranial hemorrhage or subarachnoid hemorrhage, especially in young adults, leading to serious neurologic symptoms and substantial mortality.1 BAVMs are brain vascular lesions that consist of abnormal tangles of vessels (nidus), or “bag of worms,” and lead to direct communication of arteries and veins without an interposing capillary bed.2 Current medical treatments, such as surgical removal, endovascular treatment, and stereotactic radiosurgery, are highly invasive and can lead to significant risks to nearby brain structures. Moreover, current medical treatments cannot prevent development or rupture of BAVMs.3, 4, 5

Although it is classically believed that BAVMs exist at birth, growing evidence supports the postnatal growth of BAVMs.6 Previous studies showed that some single nucleotide polymorphisms in the inflammatory cascades and in the regulation of angiogenesis play a nonspecific role in the development of hemorrhage of BAVMs.7, 8 Moreover, angiogenic factors and inflammatory cytokines are observed to contribute to manifestation of BAVMs.9, 10, 11, 12 However, the mechanism of BAVM formation is not well elucidated, and it is difficult to make a diagnosis in patients with unruptured BAVMs who present with other clinical symptoms (e.g., seizure, headache, focal neurologic deficit) or who are asymptomatic. Thus, identification of biomarkers that predict BAVM would help to improve the optimal patient management and represent a major advance in clinical care.

MicroRNAs (miRNAs) are a group of noncoding small RNAs that play an important regulatory role in various biologic processes. The expression profiles of miRNAs in tissue and peripheral blood can reflect pathologic changes in the body and brain. Peripheral blood continuously interacts with the tissues of the body, and different disease states may trigger specific changes in blood cell gene expression that could be measured at earlier stages of disease.13

For many diseases, especially diseases affecting the vasculature, tissue specimens are usually obtained only after a patient has become symptomatic and has been treated. Therefore, in the present study, we collected peripheral blood samples from 3 patients with unruptured BAVMs and 3 control subjects. The miRNA expression profiles were evaluated by next-generation sequencing. Further prediction of target genes and functional enrichment of target genes suggested that the vascular endothelial growth factor (VEGF) signaling pathway may be involved in both physiologic and pathologic angiogenesis of BAVMs. Our results suggested that 3 miRNAs (hsa-miR-7-5p, hsa-miR-199a-5p, and hsa-miR-200b-3p) may serve as potential biomarkers for BAVMs.

Section snippets

Patient Recruitment

This study complied with the Declaration of Helsinki principles and was approved by the Ethics Committee of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital. Three specimens from patients with BAVMs were obtained at the Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital according to the standardized guidelines.14 BAVMs in these patients were diagnosed by angiography and were defined as unruptured BAVMs at presentation without evidence of new

Differential Expression Profiles of Patients with BAVMs versus Control Subjects

The primary analysis compared blood miRNA expression profiles between 3 patients with BAVMs and 3 healthy control subjects to identify miRNAs showing consistent expression differences. As shown in Table 2, 10,619,255, 10,407,754, and 10,515,006 clean reads were obtained for BAVM 1, BAVM 2, and BAVM 3. There were 11,842,374, 11,829,993, and 11,828,494 clean reads obtained for Control 1, Control 2, and Control 3. Greater than 91% of clean reads can be mapped to the human reference genome.

With

Discussion

To the best of our knowledge, this is the first study to present global miRNA expression profiling in peripheral blood of BAVMs. In this study, next-generation sequencing was used to identify miRNA expression profiling in a paired design comparing patients with BAVMs and normal control subjects, which showed 246 differentially expressed miRNAs, all of which were upregulated in blood samples of BAVMs, and revealed that the aberrantly expressed miRNAs may aberrantly regulate target genes. Based

Conclusions

In conclusion, our study identified a number of novel dysregulated miRNAs in peripheral blood of BAVMs with unknown function, such as miR-629-5p, let-7b-3p, miR-6747-3p, hsa-miR-148b-5p, hsa-miR-1976, hsa-miR-1284, and hsa-miR-4433b-5p. Further elucidation of the miRNA expression signature may provide a better understanding of the mechanisms of BAVMs.44 Taken together, our study identified a miRNA expression signature in peripheral blood of patients with BAVMs and that the targeted pathway of

References (44)

  • J. van Beijnum et al.

    Treatment of brain arteriovenous malformations: a systematic review and meta-analysis

    JAMA

    (2011)
  • C.S. Haw et al.

    Complications of embolization of arteriovenous malformations of the brain

    J Neurosurg

    (2006)
  • S. Mullan et al.

    Embryological basis of some aspects of cerebral vascular fistulas and malformations

    J Neurosurg

    (1996)
  • L. Pawlikowska et al.

    Apolipoprotein E epsilon 2 is associated with new hemorrhage risk in brain arteriovenous malformations

    Neurosurgery

    (2006)
  • L. Pawlikowska et al.

    Polymorphisms in genes involved in inflammatory and angiogenic pathways and the risk of hemorrhagic presentation of brain arteriovenous malformations

    Stroke

    (2004)
  • Y. Chen et al.

    Evidence of inflammatory cell involvement in brain arteriovenous malformations

    Neurosurgery

    (2008)
  • Y. Chen et al.

    Interleukin-6 involvement in brain arteriovenous malformations

    Ann Neurol

    (2006)
  • B. Xu et al.

    Vascular endothelial growth factor induces abnormal microvasculature in the endoglin heterozygous mouse brain

    J Cereb Blood Flow Metab

    (2004)
  • Q. Hao et al.

    VEGF induces more severe cerebrovascular dysplasia in endoglin than in Alk1 mice

    Transl Stroke Res

    (2010)
  • R.P. Atkinson et al.

    Reporting terminology for brain arteriovenous malformation clinical and radiographic features for use in clinical trials

    Stroke

    (2001)
  • H. Xu et al.

    Gene expression in peripheral blood differs after cardioembolic compared with large-vessel atherosclerotic stroke: biomarkers for the etiology of ischemic stroke

    J Cereb Blood Flow Metab

    (2008)
  • M. Martin

    Cutadapt removes adapter sequences from high-throughput sequencing reads

    Embnet J

    (2011)
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    Conflict of interest statement: This study was supported by Health and Family Planning Commission of Sichuan Province: the Study of Molecular Mechanisms of Brain Arteriovenous Vascular Malformation (Grant No. 140072).

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