Na Li ^1,2,3 Zeqiang Ji ^1,2,3 Kaijiang Kang ^1,2,3 Feng Zhang ⁴ Xingquan Zhao ^1,2,3,5*

• ¹ Beijing Tiantan Hospital, Capital Medical University, Beijing, China
• ² National Clinical Research Center for Neurological Diseases (China), Beijing, Beijing, China
• ³ Research Unit of Artificial Intelligence in Cerebrovascular Disease, Chinese Academy of Medical Sciences, Beijing, China
• ⁴ Zunyi Medical University, Zunyi, Guizhou Province, China
• ⁵ Center of Stroke, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, Beijing Municipality, China

Introduction: Hematoma expansion (HE) has been identified as a crucial predictor for the progress and outcome of intracranial hemorrhage (ICH). MicroRNAs (miRNAs) are associated with HE and play essential roles in regulating the mechanism of ICH. Here, we identified a miRNA, hsa-miR-1278, as a predictor of HE and earlier estimation of ICH prognosis. Methods: The participants diagnosed with ICH by brain imaging were divided into HE and non-HE groups (defined as hematoma growth >6 mL and/or >33% from baseline to follow-up imaging). 10 samples from 2 groups were extracted and subjected to high-throughput sequencing. The differentially expressed microRNAs (DEMs) were identified by bioinformatics and quantitated by Reverse Transcription quantitive polymerase chain reaction (RT-qPCR). To further validate the DEMs, the Targetscan database was searched to find the target gene of the DEMs and cultured in the QSG7701 cells line and performed Western-blotting to validate the target miRNA. The Continuous variables were expressed as mean ± SD and analyzed by unpaired Student's t-test; categorical variables were analyzed by chi-square test, and P values < 0.05 were considered statistically significant. Results: We performed miRNA sequencing of HE and non-HE in 10 ICH patients and found 18 differentially expressed miRNAs in HE group. The RT-qPCR identified that hsa-miR-1278 was significantly increased in the HE group (P <0.05). We selected IL22 and PF4 as the target genes of has-miR-1278. RT-qPCR showed that PF4 decreased in HE group, which was consistent with the upregulation of hsa-miR-1278. Conclusions: The expression of hsa-miR-1278 was significantly upregulated in the HE group and therefore made the hsa-miR-1278 a novel predictor of ICH prognosis.