Disturbance of Immune Microenvironment in Androgenetic Alopecia through Spatial Transcriptomics.

Androgenetic alopecia (AGA) is characterized by microinflammation and abnormal immune responses, particularly in the upper segment of hair follicles (HFs). However, the precise patterns of immune dysregulation remain unclear, partly due to limitations in current analysis techniques to preserve tissue architecture. The infundibulum, a major part of the upper segment of HFs, is associated with significant clusters of immune cells. In this study, we investigated immune cells around the infundibulum, referred to as peri-infundibular immune infiltration (PII). We employed spatial transcriptome profiling, a high-throughput analysis technology, to investigate the immunological disruptions within the PII region. Our comprehensive analysis included an evaluation of overall immune infiltrates, gene set enrichment analysis (GSEA), cellular deconvolution, differential expression analysis, over-representation analysis, protein-protein interaction (PPI) networks, and upstream regulator analysis to identify cell types and molecular dysregulation in immune cells. Our results demonstrated significant differences in immune signatures between the PII of AGA patients (PII-A) and the PII of control donors (PII-C). Specifically, PII-A exhibited an enrichment of CD4+ helper T cells, distinct immune response patterns, and a bias toward a T helper (Th) 2 response. Immunohistochemistry revealed disruptions in T cell subpopulations, with more CD4+ T cells displaying an elevated Th2 response and a reduced Th1-cytotoxic response compared to PII-C. These findings reveal the unique immune landscapes of PII-A and PII-C, suggesting potential for the development of innovative treatment approaches.

Elucidating the NB-UVB mechanism by comparing transcriptome alteration on the edge and center of psoriatic plaques.

Narrow band-ultraviolet B (NB-UVB) is an effective treatment for psoriasis. We aim to generate a potential mechanism of NB-UVB through comparing the transcriptomic profile before and after NB-UVB treatment between the peripheral edge of lesional skin (PE skin) and the center of lesional skin (CE skin) on the basis of molecular mechanisms of these two areas display different downstream functions. More than one-fourth of the NB-UVB-altered genes were found to be plaque-specific. Some of them were psoriasis signature genes that were downregulated by NB-UVB in, both, PE and CE skin (core alteration), such as IL36G, DEFB4A/B, S100A15, KRT16, and KRT6A. After NB-UVB treatment, the activity score of upstream cytokines, such as interferons, interleukin (IL)-6, IL-17, and IL-22 in pathogenesis decreased. In addition, NB-UVB could restore normal keratinization by upregulating LORICRIN and KRT2, particularly in the CE skin. Finally, we illustrated that NB-UVB is capable of suppressing molecules from the initiation to maintenance phase of plaque formation, thereby normalizing psoriatic plaques. This finding supports the usefulness of NB-UVB treatment in clinical practice and may help in the development of new treatment approaches in which NB-UVB treatment is included for patients with psoriasis or other inflammatory skin diseases.

Comparison of transcriptomic profiles in edge to center of plaque reveals chronological molecular events in psoriatic plaque formation.

BACKGROUND: Peripheral edge (PE) of plaques contains inflammatory molecules and has potential to initiate plaque formation, while the center (CE) of plaques has regression trends. OBJECTIVE: To elucidate the chronological molecular events by comparing the gene profiles in PE skin to those in CE skin. METHODS: Biopsied PE, CE, and uninvolved (UN) skin samples were analyzed by next-generation sequencing. Three groups of differentially expressed genes (DEGs) were analyzed, PE/UN-, CE/UN-, and PE/CE-skin-derived DEGs. RESULTS: PE skin contained inflammation-priming molecules, such as S100A7 and S100A15, and inflammatory drivers, such as interleukin (IL)-36α. IL-6 signaling was more active in PE than in CE skin. IL-8, S100A7, S100A8, S100A9, and human ß-defensin-2 were all regulated with the similar pattern in both areas. However, PE skin created a more active inflammatory network and downstream functions, including chemotaxis and angiogenesis, were more prominent than in CE skin. Conversely, CE skin, where epidermal growth factor and hepatocyte growth factor increased their activity, was found to be more stable. CONCLUSION: This is the first RNA-seq-based report to determine the chronological molecular events in plaque formation. In the early phase, inflammation might be initiated through molecules, such as IL-36α, S100A7, and S100A15, as observed in PE skin. The inflammation state in PE skin progresses to the more stable state found in CE skin. In CE skin, the growth factor activities are increased, which might lead to attenuation of initial inflammation and initiation of the regression phase. These molecular events may accelerate research towards developing novel therapies for psoriasis.