Quantitative proteomics reveals the regulatory networks of circular RNA BTBD7_hsa_circ_0000563 in human coronary artery

BACKGROUND: BTBD7_hsa_circ_0000563, which is located on chromosome 14, contains conserved binding sites with miR‐155/130a and RNA‐binding proteins according to bioinformatic prediction. We investigated the association of BTBD7_hsa_circ_0000563 expression in coronary artery segments with atherosclerotic stenosis and identified the proteome‐wide BTBD7_hsa_circ_0000563‐regulated proteins in human coronary artery. METHODS: The atherosclerotic grade and extent in coronary artery segments were determined by hematoxylin and eosin staining. BTBD7_hsa_circ_0000563 expression in eight coronary artery segments from one patient was quantified by RT‐qPCR assay. A proteomic approach was adopted to reveal significant differences in protein expression between among four groups differing in their BTBD7_hsa_circ_0000563 expression levels. RESULTS: The RT‐qPCR assay revealed that coronary artery segments with severe atherosclerotic stenosis had significantly low BTBD7_hsa_circ_0000563 levels. The proteomic analysis identified 49 differentially expressed proteins among the segment groups with different BTBD7_hsa_circ_0000563 expression levels, of which 10 were downregulated and 39 were upregulated with increases in the BTBD7_hsa_circ_0000563 level. The 10 downregulated proteins were P61626 (LYSC_HUMAN), P02760 (AMBP_HUMAN), Q02985 (FHR3_HUMAN), P01701 (LV151_HUMAN), P06312(KV401_HUMAN), P01624 (KV315_HUMAN), P13671 (CO6_HUMAN), P01700(LV147_HUMAN), Q9Y287(ITM2B_HUMAN), and A0A075B6I0 (LV861_HUMAN). The top 10 upregulated proteins were Q92552 (RT27_HUMAN), Q9UJY1(HSPB8_HUMAN), Q9Y235(ABEC2_HUMAN), P19022 (CADH2_HUMAN), O43837(IDH3B_HUMAN), Q9H479(FN3K_HUMAN), Q9UM22(EPDR1_HUMAN), P48681(NEST_HUMAN), Q9NRP0(OSTC_HUMAN), and Q15628(TRADD_HUMAN). CONCLUSION: BTBD7_hsa_circ_0000563 is involved in the atherosclerotic changes in human coronary artery segments. Verification, mechanistic, and function studies are needed to confirm whether patients with coronary artery disease would benefit from such personalized medicine in the future.