1. Asthma & IPF related proteins collecting and analyzing
One thousand three hundred thirty-three asthma-related targets and 404 IPF-related targets were retrieved from the TTD, CTD, and DisGeNET database (Duplicates were removed and detailed in additional table S1). Asthma and IPF disease-specific PPI networks were established (figure 2A, 2B). The top 15 core proteins based on two network topology parameters (degree and betweenness centrality) in asthma and IPF were displayed in Table 1 and Table 2. Then we found that VEGFA, TP53, EGFR, AKT1, EGF, IL6, STAT3, and MYC occupied the core positions in asthma and IPF specific PPI networks, indicating the essential roles of these proteins in the pathological process of asthma and IPF. Thus, these common core proteins were the potential targets for the treatment of asthma and IPF. To further exploring the molecule link between asthma and IPF, a co-bioinformatics analysis was conducted by Metascape. One hundred twenty proteins were overlapped in the two groups of protein lists (Figure. 2C). Much of the asthma-related proteins fall into the same statistically significant GO terms (such as response to oxygen levels, leukocyte differentiation, MAPK cascades, signaling by interleukins, response to growth factor and regulation of cytokine production, etc.) with IPF-specific proteins (Figure.2D), indicating the strong function association between the two comparison cohorts. The 120 common proteins were used for further analysis.
Table 1
Top 15 core proteins in the asthma-specific PPT network.
Protein Name
|
Degree
|
Betweenness Centrality
|
Protein Name
|
Degree
|
Betweenness Centrality
|
IL6
|
507
|
0.026602
|
TP53
|
463
|
0.038446
|
GAPDH
|
500
|
0.035006
|
INS
|
464
|
0.03671
|
AKT1
|
490
|
0.031011
|
GAPDH
|
500
|
0.035006
|
TNF
|
479
|
0.025118
|
AKT1
|
490
|
0.031011
|
INS
|
464
|
0.03671
|
IL6
|
507
|
0.026602
|
TP53
|
463
|
0.038446
|
TNF
|
479
|
0.025118
|
ALB
|
434
|
0.023965
|
ALB
|
434
|
0.023965
|
VEGFA
|
400
|
0.014278
|
EGFR
|
391
|
0.01915
|
EGFR
|
391
|
0.01915
|
HSP90AA1
|
243
|
0.019129
|
MAPK3
|
367
|
0.010079
|
MYC
|
360
|
0.014939
|
STAT3
|
362
|
0.010978
|
VEGFA
|
400
|
0.014278
|
MYC
|
360
|
0.014939
|
NME8
|
54
|
0.012606
|
CXCL8
|
358
|
0.008725
|
EGF
|
354
|
0.012404
|
EGF
|
354
|
0.012404
|
APP
|
236
|
0.012177
|
IL10
|
353
|
0.008187
|
MAPK1
|
316
|
0.012167
|
Table 2
Top 15 core proteins in the IPF specific PPT network.
Protein Name
|
Degree
|
Betweenness Centrality
|
Protein Name
|
Degree
|
Betweenness Centrality
|
IL6
|
129
|
0.049704
|
TP53
|
119
|
0.083659
|
AKT1
|
129
|
0.082012
|
AKT1
|
129
|
0.082012
|
TP53
|
119
|
0.083659
|
FN1
|
114
|
0.070219
|
EGFR
|
115
|
0.05726
|
EGFR
|
115
|
0.05726
|
FN1
|
114
|
0.070219
|
IL6
|
129
|
0.049704
|
VEGFA
|
112
|
0.046531
|
VEGFA
|
112
|
0.046531
|
EGF
|
110
|
0.029447
|
MYC
|
104
|
0.042975
|
TNF
|
108
|
0.020339
|
ESR1
|
88
|
0.039777
|
MYC
|
104
|
0.042975
|
EGF
|
110
|
0.029447
|
STAT3
|
100
|
0.026734
|
TERT
|
34
|
0.02814
|
JUN
|
98
|
0.027703
|
JUN
|
98
|
0.027703
|
IL1B
|
96
|
0.016969
|
ACTB
|
76
|
0.027551
|
CXCL8
|
96
|
0.016948
|
STAT3
|
100
|
0.026734
|
ESR1
|
88
|
0.039777
|
CDH1
|
87
|
0.026659
|
CDH1
|
87
|
0.026659
|
CFTR
|
28
|
0.025087
|
2. Active ingredients screening and corresponding targets prediction of BSYQ decoction.
After removing duplicates, 175 active ingredients were acquired and further submitted to TCMSP, BATMAN-TCM, and ETCM databases to get the corresponding targets. Finally, except for 59 components predicted no targets, 116 active compounds and 1535 related targets were retrieved (additional tables S2 and S3). The compound-target (C-T) network was constructed and analyzed via Cytoscape 3.8.0 (figure 3A, B). The C-T network consists of 1651 nodes (116 active compounds and 1535 potential targets) and 5255 edges. Two centrality indicators, degree and betweenness centrality, were calculated to identify the critical nodes within the network (figure 3B). Interestingly, both two types of centrality indicators uniformly confirmed the core 15 candidate compounds (including adenosine, cetylic acid, octadecanoic, linolenic acid and quercetin, etc.) and targets (including PTGS2, NCOA2, AR, ESR1, and PTGS1, etc.) of BSYQ decoction (Table 3 and Table 4).
Table 3
Top 15 active compounds in the C-T network according to degree and betweenness centrality.
Ingredient Name
|
Degree
|
Betweenness Centrality
|
Ingredient Name
|
Degree
|
Betweenness Centrality
|
Adenosine, Adenine Nucleoside
|
414
|
0.282464182
|
Adenosine, Adenine Nucleoside
|
414
|
0.282464
|
Cetylic Acid,Hexadecanoic Acid,Palmitic Acid
|
370
|
0.169742477
|
Linolenic Acid
|
259
|
0.175644
|
Octadecanoic?Acid,Stearic Acid
|
320
|
0.114930316
|
Cetylic Acid,Hexadecanoic Acid,Palmitic Acid
|
370
|
0.169742
|
Linolenic Acid
|
259
|
0.175644195
|
Quercetin
|
237
|
0.125366
|
Quercetin
|
237
|
0.125365848
|
Gamma-Aminobutyric Acid
|
224
|
0.121065
|
Gamma-Aminobutyric Acid
|
224
|
0.121065221
|
Octadecanoic?Acid,Stearic Acid
|
320
|
0.11493
|
Canavanine
|
149
|
0.069555043
|
FA
|
127
|
0.082434
|
Kaempferol
|
137
|
0.030226515
|
Canavanine
|
149
|
0.069555
|
luteolin
|
129
|
0.032355609
|
Sucrose
|
63
|
0.039162
|
FA
|
127
|
0.082434046
|
Uridine
|
82
|
0.037645
|
Beta-Sitosterol
|
115
|
0.02578383
|
D-Mannitol,Cordycepic Acid
|
98
|
0.034955
|
D-Mannitol,Cordycepic Acid
|
98
|
0.034955394
|
luteolin
|
129
|
0.032356
|
Lupeol
|
98
|
0.020896911
|
Kaempferol
|
137
|
0.030227
|
Isorhamnetin
|
89
|
0.011006298
|
Beta-Sitosterol
|
115
|
0.025784
|
sitosterol
|
83
|
0.010530446
|
3,5-Dimethoxystilbene
|
61
|
0.024598
|
Table 4
Top 15 candidate targets in the C-T network according to degree and betweenness centrality.
Protein Name
|
Degree
|
Betweenness Centrality
|
Protein Name
|
Degree
|
Betweenness Centrality
|
PTGS2
|
54
|
0.035328
|
PTGS1
|
42
|
0.035343
|
NCOA2
|
49
|
0.01164
|
PTGS2
|
54
|
0.035328
|
AR
|
48
|
0.020706
|
AR
|
48
|
0.020706
|
ESR1
|
46
|
0.004363
|
PPARG
|
23
|
0.015876
|
PTGS1
|
42
|
0.035343
|
ACHE
|
18
|
0.013354
|
RXRA
|
31
|
0.009231
|
NCOA2
|
49
|
0.01164
|
GABRA1
|
29
|
0.003085
|
TNF
|
12
|
0.0116
|
ESR2
|
28
|
0.001461
|
PPARA
|
12
|
0.01123
|
PIM1
|
27
|
0.004446
|
ADORA1
|
10
|
0.010569
|
HSP90A
|
27
|
0.001984
|
SCN5A
|
22
|
0.010239
|
PRSS1
|
26
|
9.40E-04
|
SHMT1
|
9
|
0.010117
|
PGR
|
25
|
4.98E-04
|
ATP1A2
|
18
|
0.009873
|
ATP1A1
|
24
|
0.005754
|
XDH
|
10
|
0.009636
|
AHR
|
24
|
0.004933
|
RXRA
|
31
|
0.009231
|
PPARG
|
23
|
0.015876
|
IL1B
|
8
|
0.009034
|
3. Potential ingredients and targets of BSYQ decoction for asthma and IPF therapy
To further explore the molecule mechanisms of BSYQ decoction for asthma and IPF therapy, we took the intersection of the target's profile of BSYQ decoction with the 120 common proteins between asthma and IPF. Finally, 56 potential targets were retrieved and were regarded as the potential targets for asthma and IPF treatment (figure 3C). Then a potential compound -potential target (PC-PT) network was established and analyzed (figure 3D). The PC-PT network consists of 139 nodes (83 potential compounds and 56 potential targets) and 371 edges. The core potential ingredients and targets based on the two network parameters were shown in Tables 5 and Table 6. Quercetin, luteolin, linolenic acid, adenosine, kaempferol, etc., were considered the potential core compounds, and PTGS2, ESR1, PTGS1, NOS2, and AKT1, etc. were the main potential targets of BSYQ for asthma and IPF therapy. We further constructed the PPI network with the 56 potential targets by STRING and searched the similar function clusters of the PPI network by MCODE analysis based on topology (figure 4). The top 15 core proteins based on the two topological parameters in the 56 potential targets PPI network were showed in Table 7. IL6, IL-1β, TNF, VEGFA, and AKT1, etc., played an essential role in the PPI network, indicating the crucial roles in treating asthma and IPF. Similar function subnetworks were constructed, function analysis showed that cluster 1 mainly participated in the interleukins signaling (figure 4B). Cluster 2 specifically regulates the reactive oxygen species (figure 4C). Cluster 3 mainly regulates the cytokines and inflammatory response (figure 4D). Then we performed the GO and KEGG analysis with the 56 potential targets (figure 5). KEGG pathway analysis showed that TNF signaling pathway, HIF-1 signaling pathway, cytokine-cytokine receptor interaction, toll-like receptor signaling pathway, and MAPK signaling pathway, etc. were enriched and regulated by BSYQ decoction (figure 5A, 5B), indicating the underline comprehensive mechanisms of BSYQ decoction for asthma and IPF treatment. We found that the 56 potential targets mainly participate in the regulation of the inflammatory response, nitric oxide biosynthetic process, and smooth muscle cell proliferation process, etc. (figure 5C)
Table 5
Top 15 potential compounds in the PC-PT network according to degree and betweenness centrality.
Ingredient Name
|
Degree
|
Betweenness Centrality
|
Ingredient Name
|
Degree
|
Betweenness Centrality
|
Quercetin
|
36
|
0.309833105
|
Quercetin
|
36
|
0.309833105
|
luteolin
|
20
|
0.074877417
|
Sucrose
|
6
|
0.104421054
|
Linolenic Acid
|
16
|
0.076791716
|
Adenosine,Adenine Nucleoside
|
15
|
0.079102825
|
Adenosine,Adenine Nucleoside
|
15
|
0.079102825
|
Linolenic Acid
|
16
|
0.076791716
|
Kaempferol
|
14
|
0.048065771
|
luteolin
|
20
|
0.074877417
|
Isorhamnetin
|
11
|
0.010756097
|
Kaempferol
|
14
|
0.048065771
|
Rhamnocitrin
|
10
|
0.00855788
|
Canavanine
|
6
|
0.033126673
|
Pratensein
|
10
|
0.00855788
|
FA
|
6
|
0.029886082
|
Formononetin
|
10
|
0.01317824
|
TGFBR2
|
4
|
0.029023858
|
Beta-Sitosterol
|
9
|
0.019445351
|
Fructose
|
4
|
0.019612123
|
Cetylic Acid,Hexadecanoic Acid,Palmitic Acid
|
8
|
0.017682546
|
Beta-Sitosterol
|
9
|
0.019445351
|
Kumatakenin
|
7
|
0.005434062
|
Cetylic Acid,Hexadecanoic Acid,Palmitic Acid
|
8
|
0.017682546
|
Canavanine
|
6
|
0.033126673
|
Hentriacontanol-6
|
2
|
0.014492754
|
Sucrose
|
6
|
0.104421054
|
Medicarpin
|
6
|
0.013850015
|
Octadecanoic?Acid,Stearic Acid
|
6
|
0.010597854
|
(6aR,11aR)-9,10-dimethoxy-6a,11a-dihydro-6H-benzofurano[3,2-c]chromen-3-ol
|
6
|
0.013850015
|
Table 6
Top 15 potential targets in the PC-PT network according to degree and betweenness centrality.
Protein Name
|
Degree
|
Betweenness Centrality
|
Protein Name
|
Degree
|
Betweenness Centrality
|
PTGS2
|
54
|
0.277312173
|
PTGS2
|
54
|
0.277312173
|
ESR1
|
46
|
0.153120648
|
PTGS1
|
42
|
0.204507204
|
PTGS1
|
42
|
0.204507204
|
ESR1
|
46
|
0.153120648
|
NOS2
|
19
|
0.032615148
|
CXCR4
|
8
|
0.086469588
|
AKT1
|
15
|
0.01512124
|
TNF
|
12
|
0.060803175
|
GSK3B
|
13
|
0.009859331
|
CYP3A4
|
12
|
0.058290209
|
CYP3A4
|
12
|
0.058290209
|
HMOX1
|
6
|
0.035902065
|
TNF
|
12
|
0.060803175
|
HIF1A
|
4
|
0.035245261
|
ACTB
|
10
|
0.013813159
|
ICAM1
|
5
|
0.034843635
|
MAPK14
|
10
|
0.001209612
|
NOS2
|
19
|
0.032615148
|
CEBPB
|
9
|
0.007230542
|
IL1B
|
8
|
0.031406599
|
ANXA1
|
8
|
0.014493758
|
TGFBR2
|
4
|
0.029023858
|
CXCR4
|
8
|
0.086469588
|
IFNG
|
4
|
0.016903104
|
IL1B
|
8
|
0.031406599
|
AKT1
|
15
|
0.01512124
|
IL6
|
6
|
0.009704189
|
SERPINE1
|
5
|
0.014896122
|
Table 7
Top 15 potential targets in the 56 potential targets PPI network
Protein Name
|
Degree
|
Betweenness Centrality
|
Protein Name
|
Degree
|
Betweenness Centrality
|
IL6
|
51
|
0.059767121
|
IL6
|
51
|
0.059767121
|
IL1B
|
46
|
0.034930701
|
EGFR
|
43
|
0.041706178
|
TNF
|
46
|
0.030700549
|
VEGFA
|
46
|
0.038701872
|
VEGFA
|
46
|
0.038701872
|
IL1B
|
46
|
0.034930701
|
AKT1
|
45
|
0.034171523
|
AKT1
|
45
|
0.034171523
|
PTGS2
|
44
|
0.027625229
|
TNF
|
46
|
0.030700549
|
EGFR
|
43
|
0.041706178
|
ESR1
|
33
|
0.030204633
|
EGF
|
42
|
0.022481519
|
PTGS2
|
44
|
0.027625229
|
JUN
|
40
|
0.025683985
|
JUN
|
40
|
0.025683985
|
CCL2
|
39
|
0.015488887
|
EGF
|
42
|
0.022481519
|
MMP2
|
37
|
0.009780132
|
MAPK14
|
34
|
0.021812819
|
IL4
|
36
|
0.013415867
|
CCL2
|
39
|
0.015488887
|
TGFB1
|
35
|
0.009526729
|
IL4
|
36
|
0.013415867
|
MAPK14
|
34
|
0.021812819
|
CEBPB
|
20
|
0.011576047
|
ICAM1
|
33
|
0.005648341
|
CXCL10
|
27
|
0.011252843
|
4. Molecule docking for the core potential ingredients and targets of BSYQ for asthma and IPF treatment
In the current study, the possible interaction modes between core ingredients and targets were predicted by Autodock vina. Molecule docking is a computational method that efficiently predicts the noncovalent binding of macromolecules or, more frequently, of a macromolecule (receptor) and a small molecule (ligand). It is generally believed that the lower the binding energy between ligand and receptor, the greater the possibility of interaction. Three core ingredients, including quercetin, luteolin, and kaempferol with four corresponding essential targets including AKT1, IL-6, PTGS2, and TNF, were docked and displayed to elucidate the exact binding mode (figure 6, A: kaempferol-AKT1; B: luteolin-AKT1; C: quercetin-AKT1; D: kaempferol-IL-6; E: luteolin-IL-6; F: quercetin-IL-6; G: kaempferol-PTGS2; H: luteolin-PTGS2; I: quercetin-PTGS2; J: kaempferol-TNF; K: luteolin-TNF; L: quercetin-TNF). Specifically, taking the kaempferol with AKT1, for example, five typical hydrogen bonds were established between kaempferol and AKT1 by engaging with essential amino acids such as SER205A, THR211A, and VAL271A inside the interfaced pocket created by active amino acid residues of AKT1. In the active site, there were also π-Stacking interactions between kaempferol and TRP80A, as well as hydrophobic interactions with TRP80A, LEU210A, and VAL270A, which helped stabilize the molecule at the binding site (figure 6A). Six key hydrogen bonds with SER205A, THR211A, and VAL271A, hydrophobic interactions with TRP80A, LEU210A, LEU240A, and VAL270A, and π-Stacking interaction with TRP80A, were established between luteolin and AKT1 (figure 6B). Similarly, quercetin and AKT1 were shown to create five critical hydrogen bonds with SER205A, THR211A, and VAL271A, hydrophobic contacts with TRP80A, LEU210A, VAL270A, and ASP292A, and π-Stacking interaction with TRP80A (figure 6C). Between kaempferol and IL-6, seven important hydrogen bonds were discovered with ARG104A, GLU106A, SER108A, GLN156A, and ASP160A, as well as hydrophobic interactions with LYS46A and PHE105A, and π-Cation interactions with LYS46A were found (figure 6D). Five critical hydrogen bonds with THR43A, LYS46A, ARG 104A, GLU106A, and THR163A, hydrophobic interactions with LYS46A, ARG104A, and PHE105A, and π-Cation interactions with LYS46A and ARG 104A were formed between luteolin and IL-6 (figure 6E). Quercetin and IL-6 formed seven critical hydrogen bonds with GLU42A, ARG104A, GLU106A, SER107A, SER108A, and GLN156A, as well as hydrophobic interactions with LYS46A and PHE105A, and π-Cation interactions with LYS46A (figure 6F). Between kaempferol and PTGS2, six critical hydrogen bonds with ARG44A, ILE124A, ASP125A, SER126A, and GLN372A, as well as hydrophobic interactions with PRO542B and GLN543B, were discovered (figure 6G). Three key hydrogen bonds with SER126A and LYS546B, hydrophobic interactions with ARG44A, PRO542B, and GLN543B, were established between luteolin and PTGS2 (figure 6H). Quercetin and PTGS2 were shown to have three critical hydrogen bonds with ARG44A, SER126A, and LYS546B. Hydrophobic interactions with ARG44A, PRO542B, and GLN543B, and π-Cation interaction with ARG44A were predicted (figure 6I). Between kaempferol and TNF, four key hydrogen bonds with SER60B, GLN61A, TYR151A, and TYR151B, hydrophobic interactions with TYR59B and TYR119A, and π-Stacking interaction with TYR119A and TYR119B, were recognized (figure 6J). Five key hydrogen bonds with SER60B, LEU120B, GLY121A, TYR151A, and TYR151B, hydrophobic interactions with TYR59B and TYR119A, and π-Stacking interaction with TYR119A and TYR119B, were formed between luteolin and TNF (figure 6K). Quercetin and TNF established five critical hydrogen bonds with GLY121A, TYR151A, and TYR151B, hydrophobic interactions with TYR119A, and π-Stacking interactions with TYR119A (figure 6L). Taken together, hydrogen-bonding, π-stacking, π-cation, and hydrophobic interaction played key roles in the protein−ligand recognition and stability, which may be helpful for the activation or inhibition of the target proteins and is necessary for the pharmacology activities.