Information of the Included Microarrays
GSE161683, GSE181318, GSE162998, GSE166388, GSE117468, and GSE136757 were included in this study based on the previously specified inclusion criteria. There were 185 lesional skin (LP) and 177 non-lesional skin (NP) samples in these six datasets. Table 1 displays the specific details of these datasets.
Table 1 information about the datasets used in our study
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tissues
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GSEID
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analysis type
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platform
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Database
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9 NP and 9 LP
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GSE161683
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expression profiling by array
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GPL6244
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GEO
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3 NP and 3 LP
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GSE181318
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expression profiling by array
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GPL22120
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GEO
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3 NP and 11 LP
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GSE162998
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expression profiling by array
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GPL8432
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GEO
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4 NP and 4 LP
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GSE166388
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expression profiling by array
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GPL570
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GEO
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128 NP and 128 LP
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GSE117468
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expression profiling by array
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GPL570
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GEO
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30 NP and 30 LP
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GSE136757
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expression profiling by array
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GPL570
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GEO
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84 NP and 83 LP
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GSE117239
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expression profiling by array
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GPL570
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GEO
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4 NP and 4 LP
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GSE50790
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expression profiling by array
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GPL570
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GEO
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6 NP and 17 LP
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GSE151177
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high throughput sequencing
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GPL18573
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GEO
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Identification of PRGs in psoriasis
The standardized results are displayed in Supplemental Fig. 1 for each dataset, with all samples achieving acceptable homogeneity. Figure 1 depicts volcano plots generated from the six microarrays. Each gene in each dataset was thought to be randomly sorted by the RRA approach. There were altogether 52 PRGs found from 984 DEGs in the psoriasis versus healthy samples across the entire dataset, with 38 showing up-regulation and 14 showing down-regulation (Supplementary Table 1). In Fig. 2A, a heatmap is presented showcasing the top 10 genes that were both up- and down-regulated. The analysis revealed that out of the significant genes that displayed aberrant expression in psoriasis, 9 of them were up-regulated; these include LCN2 (P = 1.22E-05), TCN1 (P = 1.67E-04), TMBIM6 (P = 2.19E-04), AKR1B10 (P = 5.18-04), PI3 (8.72E-04), TLR3 (P = 8.72E-04), MMP1 (P = 8.72E-04), S100A12 (P = 1.6E-04), and PRKCQ (P = 2.1E-04). Furthermore, one gene, BCL6 (P = 7.55E-04), was found to be down-regulated. The gene associations are exhibited in Fig. 2B.
Functional enrichment analysis of PRGs from the GSE117239 dataset
The biological processes and pathways linked to PRGs were identified using GO functional annotation and Reactome pathway analysis. As a result, PRGs were significantly enriched in the following GO-molecular function (MF) terms, including “RAGE receptor binding”, “signaling receptor activator activity”, “chemokine activity”, “Toll − like receptor binding”, “cytokine activity”, “protease binding”, “long − chain fatty acid binding”, “growth factor activity”, “chemokine receptor binding” and “receptor ligand activity”. Regarding cellular component (CC) terms, PRGs were markedly associated with “secretory granule lumen”, “secretory granule lumen”, “clathrin − coated endocytic vesicle membrane”, “clathrin − coated vesicle membrane”, “clathrin − coated endocytic vesicle”, “endocytic vesicle membrane”, “specific granule lumen”, “coated vesicle membrane”, “specific granule lumen” and “vesicle lumen”. Also, the annotation of GO-biological process (BP) terms indicated the close relation of PRGs with “regulation of DNA − binding transcription factor activity”, “positive regulation of inflammatory response”, “positive regulation of DNA − binding transcription factor activity”, “defense response to bacterium”, “positive regulation of defense response”, “regulation of inflammatory response”, “chronic inflammatory response”, “positive regulation of NF − kappaB transcription factor activity”, “neutrophil chemotaxis” and “positive regulation of response to external stimulus” (Fig. 2C). Based on Reactome pathway analysis, IL − 17 signaling pathway, Lipid and atherosclerosis, Hippo signaling pathway, Cytokine − cytokine receptor interaction, Cholesterol metabolism, Pyrimidine metabolism, Adipocytokine signaling pathway, Viral protein interaction with cytokine and cytokine receptor, PPAR signaling pathway, and Wnt signaling pathway were significantly enriched (Fig. 2D). The above-mentioned results suggested that PRGs might significantly affect psoriasis pathogenesis by controlling autophagy, cytokines, kinases, and immune cells.
4 PRGs served as the diagnostic genes for psoriasis
Furthermore, DEGs obtained by LASSO and SVM-RFE were screened, and this study concentrated on the prediction of whether PRGs could be applied in disease diagnosis. To this end, the GSE117239 dataset was used to analyze two distinct machine learning techniques, LASSO and SVM-RFE, so as to select PRGs that significantly identified patients with psoriasis from healthy individuals. By using the LASSO logistic regression that selected six psoriasis-related characteristics, the penalty parameter was adjusted (Figs. 3A, B). Also, the SVM-RFE algorithm was applied to filter PRGs, and six best characteristic gene combinations were obtained (minimal RMSE = 0.00606, maximal accuracy = 0.994) (Figs. 3C,D). Subsequently, in further investigations, four marker genes (TCN1, S100A12, PRKCQ, and ABCC1) were obtained by intersecting the marker genes obtained from the two aforementioned algorithms (Fig. 3G). The DEGs obtained from RRA analysis were modeled logistically, the results distinguished well between NP and LP samples (Fig. 3E,F), and the four marker bases were filtered by machine learning for better differentiation (Fig. 3H, I).
Marker genes exhibited close relations to several pathways connected to psoriasis
The single-gene GSEA-KEGG pathway analysis was carried out to more thoroughly investigate the potential functions of marker genes in differentiating psoriasis from healthy samples. These four marker gene-associated pathways are shown in Fig. 4. After a thorough analysis of marker genes, it was discovered that they were significantly linked to the cytokine-cytokine receptor interaction, the Nod-like receptor pathway, the JAK-STAT pathway, the Toll-like receptor pathway, as well as several disease pathways (graft versus host disease and type I diabetes mellitus). Typically, the "cytokine-cytokine receptor interaction" was a common pathway among all marker genes.
In addition, GO analysis was performed on the four PRGs, as a result, all these four genes were associated with “cytokine activity", with S100A12, PRKCQ, and ABCC1 being associated with “intermediate filament”, “keratin filament”, and “response to cytokine response” separately, as shown in Fig. 4.
To find potential medications targeting marker genes, DGIdb database was used for analysis, and the two-parameter interaction relation was left at default (Supplementary Table 2). A total of 73 medicines that targeted marker genes were investigated, including one for TCN1, five for S100A12, seventeen for PRKCQ, and fifty for ABCC1. In our subject paper, we conducted a search in the cMap database to identify potential natural active ingredients for treating psoriasis using PANoptosis. The cMap database assigns a score to measure the correlation between small molecules and genes. A score closer to 1 indicates a positive correlation between genes and drugs, while a score closer to -1 represents a negative correlation. The study's findings indicate that BRD-K34812979, WYE-125132, and BRD-K27925875 could potentially serve as small molecule components for treating psoriasis. Additionally, Supplementary Table 3 highlights the top 10 small molecule components with lower scores that could treat psoriasis by inhibiting PANoptosis. Meanwhile, we utilized HERB (http://herb.ac.cn/) to investigate the relationship between diagnostic gene biomarkers and traditional Chinese medicine. Visualization images were generated using cytoscape 3.9.0. Our findings revealed that PRKCQ targets 11 natural medicines, as depicted in Fig. 5A. Additionally, S100A12 was found to be associated with 35 natural medicines, as shown in Fig. 5B. Finally, ABCC1 was found to have a connection with 25 natural drugs, as illustrated in Fig. 5C.
Finally, using the GSE50790 dataset, the expression levels of marker genes were verified. Our findings revealed that the expression profiles of TCN1, S100A12, PRKCQ, and ABCC1 were identical to those in the GSE117239 dataset. Moreover, it is noteworthy that the levels of TCN1, S100A12, ABCC1, and PRKCQ expression were found to be considerably elevated in patients with psoriasis, as compared to those in the healthy control group, based on statistically significant data (Fig. 6A,B,C,D).
In total, thirteen psoriasis lesional skin and five healthy volunteer skin samples were collected, and there were 14,640 cells passing the quality control (Fig. 7A), including 11,462 from psoriasis samples, while the remaining from healthy samples with the following cell types (Fig. 7B). Single-cell samples can be divided into 5 major categories, DC cells, keratinocytes, monocyte,T cells, and tissue stem cells(Fig. 7C). Afterward, cells were divided into 15 clusters (Fig. 8). Of them, Chondrocytes, DC, Endothelial cells, Epithelial cells, Fibroblasts, Keratinocytes, Macrophage, Monocyte, MSC, Neurons, NK cell, ProB cell CD34+, ProMyelocyte, T cells, Tissue stem cells were among the 14 major cell types found in psoriasis (Fig. 8B). Thereafter, four marker genes, namely, TCN1, S100A12, PRKCQ, and ABCC1, were examined. The levels of these genes were noted in the associated cell types (Figs. 8B, C). Results for healthy tissues and psoriasis tissues are displayed in Figs. 8D, F. Marker genes were predominantly distributed in keratinocytes within the psoriasis samples. To be specific, TCN1, S100A12, and ABCC1 were mostly distributed in Keratinocytes, while PRKCQ was predominantly expressed in NK cells.