Integrated Bioinformatics Analysis Reveals Diagnostic Biomarkers and Immune Cell Infiltration Characteristics of Solar Lentigines

Xin Yang,1,2,* Zhikuan Xia,1,* Yunlong Fan,1 Yitong Xie,1 Ge Ge,1 Dexiu Lang,3 Junhong Ao,1 Danxia Yue,1 Jiamin Wu,1 Tong Chen,1 Yuekun Zou,1 Mingwang Zhang,4 Rongya Yang1,2 1Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Beijing, People’s Republic of China; 2Department of Dermatology, Yanbian University Hospital, Yanji, People’s Republic of China; 3Department of Dermatology, XingYi People’s Hospital, Xingyi, People’s Republic of China; 4Department of Dermatology, Southwest Hospital, Army Medical University, Chongqing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Mingwang Zhang; Rongya Yang, Email mingwangzhang2@163.com; yangrya@sina.comBackground: Solar lentigines (SLs), serving as a prevalent characteristic of skin photoaging, present as cutaneous aberrant pigmentation. However, the underlying pathogenesis remains unclear and there is a dearth of reliable diagnostic biomarkers.Objective: The aim of this study was to identify diagnostic biomarkers for SLs and reveal its immunological features.Methods: In this study, gene expression profiling datasets (GSE192564 and GSE192565) of SLs were obtained from the GEO database. The GSE192564 was used as the training group for screening of differentially expressed genes (DEGs) and subsequent depth analysis. Gene set enrichment analysis (GSEA) was employed to explore the biological states associated with SLs. The weighted gene co-expression network analysis (WGCNA) was employed to identify the significant modules and hub genes. Then, the feature genes were further screened by the overlapping of hub genes and up-regulated differential genes. Subsequently, an artificial neural network was constructed for identifying SLs samples. The GSE192565 was used as the test group for validation of feature genes expression level and the model’s classification performance. Furthermore, we conducted immune cell infiltration analysis to reveal the immune infiltration landscape of SLs.Results: The 9 feature genes were identified as diagnostic biomarkers for SLs in this study. And an artificial neural network based on diagnostic biomarkers was successfully constructed for identification of SLs. GSEA highlighted potential role of immune system in pathogenesis of SLs. SLs samples had a higher proportion of several immune cells, including activated CD8 T cell, dendritic cell, myeloid-derived suppressor cell and so on. And diagnostic biomarkers exhibited a strong relationship with the infiltration of most immune cells.Conclusion: Our study identified diagnostic biomarkers for SLs and explored its immunological features, enhancing the comprehension of its pathogenesis.Keywords: solar lentigines, photoaging, diagnostic biomarkers, immune infiltration, artificial neural network