Identification and Bioinformatic Analysis of Circular RNA Expression in Peripheral Blood Mononuclear Cells from Patients with Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Basic Clinical Information of Participants

Characteristics	COPD (n = 21)	NC (n = 21)
Gender (male/female)	13/8	12/9
Mean age (years)	66.7 ± 4.0	63.5 ± 7.4
Mean BMI (kg/m^2)	25.0 ± 3.4	25.2 ± 3.8
FEV1% predicted	63.5 ± 18.6	92.8 ± 16.1**
FEV1/FVC	48.6 ± 15.5	74.7 ± 4.6**
Current/ex-smokers	13	12
Pack-years	28.0 ± 6.0	20.0 ± 3.0
Medication status
LABA	1	NA
LAMA	14	NA
LABA+ICS	9	NA
LAMA+ICS	3	NA
Theophylline drugs	3	NA
Aspirin	4	3
Complications
Hypertension	5	2
Peptic ulcer	1	0
Lacunar cerebral infarction	2	1

Notes: Data are presented as mean ± SD. Pack-years were defined as the number of cigarettes smoked per day divided by 20 and then multiplied by the number of years smoked. **P-value < 0.001.

Abbreviations: COPD, chronic obstructive pulmonary disease; NC, normal controls; BMI, body mass index; FEV1, forced expiratory volume in 1 second; FEV1% predicted, forced expiratory volume in 1 second as percentage of predicted value; FVC, forced vital capacity; LABA, long-acting beta-2 agonist; ICS, inhaled corticosteroid; LAMA, long-acting muscarinic antagonist; SD, standard deviation; NA, not available.

Table 2 Ten Most Up-Regulated and Down-Regulated Circular RNAs in COPD Patients Compared to Normal Controls

No.	Gene Symbol	Regulation	FC	P-value	Chromosome
1	hsa_circ_0007294	Up	1.828	0.000235181	chr12
2	hsa_circ_0004903	Up	1.828	0.000152574	chr20
3	hsa_circ_0003003	Up	1.717	1.06128E-05	chr6
4	hsa_circ_0000157	Up	1.670	0.002107531	chr1
5	hsa_circ_0001853	Up	1.647	0.009231771	chr9
6	hsa_circ_0043926	Up	1.625	0.013286737	chr17
7	hsa_circ_0002136	Up	1.591	0.003380009	chr2
8	hsa_circ_0026466	Up	1.580	2.31772E-06	chr12
9	hsa_circ_0051433	Up	1.569	0.000198442	chr19
10	hsa_circ_0000364	Up	1.558	0.000211056	chr11
11	hsa_circ_0000074	Down	−11.004	2.32503E-09	chr1
12	hsa_circ_0025453	Down	−10.853	9.77445E-13	chr12
13	hsa_circ_0056158	Down	−10.056	5.98183E-10	chr2
14	hsa_circ_0075043	Down	−9.514	1.54647E-11	chr5
15	hsa_circ_0077995	Down	−5.696	5.68273E-11	chr6
16	hsa_circ_0051785	Down	−5.315	8.65909E-12	chr19
17	hsa_circ_0031660	Down	−4.408	6.97663E-09	chr14
18	hsa_circ_0001744	Down	−4.141	1.59018E-09	chr7
19	hsa_circ_0043144	Down	−4.056	3.48066E-10	chr17
20	hsa_circ_0064900	Down	−3.864	3.46705E-10	chr3

Table 3 Ten Most Up-Regulated and Down-Regulated mRNAs in COPD Patients Compared to Normal Controls

No.	Gene Symbol	Regulation	FC	P-value	Chromosome
1	KIDINS220	Up	1.959	1.25949E-09	chr2
2	ANKS1B	Up	1.828	0.000235181	chr12
3	CCR4	Up	1.647	0.011224379	chr3
4	FFAR1	Up	1.636	0.000325624	chr19
5	RPL27	Up	1.625	0.013286737	chr17
6	RGPD3	Up	1.602	0.002016005	chr2
7	KRT8	Up	1.580	2.31772E-06	chr12
8	CLASRP	Up	1.569	0.000198442	chr19
9	TMBIM1	Up	1.548	5.27563E-08	chr2
10	IGFBP3	Up	1.526	0.004996072	chr7
11	FOS	Down	−17.388	1.64945E-11	chr14
12	CXCL8	Down	−14.825	5.0726E-06	chr4
13	JUN	Down	−11.004	2.32503E-09	chr1
14	CD69	Down	−10.853	9.77445E-13	chr12
15	RGS1	Down	−10.267	5.2533E-11	chr1
16	IL1B	Down	−10.056	5.98183E-10	chr2
17	G0S2	Down	−8.225	1.06143E-07	chr1
18	EGR1	Down	−7.013	0.000309397	chr5
19	NR4A2	Down	−5.696	4.99191E-10	chr2
20	TNFAIP3	Down	−5.696	5.68273E-11	chr6

Figure 1 CircRNA and mRNA expression profile in COPD patients. Volcano plots were used to distinguish differentially expressed circRNAs (A) and mRNAs (B). Red and blue indicate up-regulation and down-regulation, respectively.

Figure 2 GO and KEGG pathway analysis. GO analysis of significantly up-regulated (A) and down-regulated (B) mRNAs clustered in the CC, MF, and BP. KEGG analysis of differentially up-regulated (C) and down-regulated mRNAs (D). The x‐axis shows ‐lgP, and the y-axis shows GO terms or KEGG pathways.

Abbreviations: GO, Gene Ontology; KEGG, Kyoto Encyclopedia of Genes and Genomes; BP, biological process; CC, cellular component; MF, molecular function.

Figure 3 Validation of microarray data by RT‐qPCR. (A) Relative expression levels of the circRNAs and mRNAs between the COPD group and normal control group, assessed by RT-qPCR. The heights of the columns in the chart represent the relative expression (2^−ΔΔCT). Data are mean ± SEM. All data were normalized to GAPDH gene expression. (B) Comparison of mean fold changes between microarray data and RT-qPCR results. SEM, standard error of the mean. ****P-value < 0.0001. **P-value < 0.001. ns, no significance.