广西医学

目的探讨血小板衍生生长因子A（PDGFA）在瘢痕疙瘩组织中的表达特征及其促纤维化作用机制。方法在GEO数据库中检索瘢痕疙瘩相关单细胞RNA测序数据集，分析PDGFA在瘢痕疙瘩组织中的表达水平及相关细胞特征。在GEO数据库、SRA数据库和ArrayExpress数据库中搜索并下载包含瘢痕疙瘩组织样本和正常瘢痕组织样本的RNA测序数据集和基因芯片数据集，分析PDGFA在瘢痕疙瘩组织中的表达水平及对瘢痕疙瘩的诊断效能。从某医院收集13例正常瘢痕组织样本和12例瘢痕疙瘩组织样本用于基因表达测序，分析PDGFA在临床样本中的表达水平及对瘢痕疙瘩的诊断效能。对RNA测序数据集和基因芯片数据集瘢痕疙瘩组织中高表达的基因、临床病例瘢痕疙瘩组织中高表达的基因、与PDGFA共表达的基因进行交集分析，针对交集基因进行京都基因与基因组百科全书通路富集分析与基因本体论功能富集分析。利用DSigDB数据库与GSEA软件筛选出5种潜在的PDGFA靶向小分子药物，采用分子对接技术验证这些靶向小分子药物与PDGFA蛋白的结合活性。结果在单细胞RNA测序数据集中，PDGFA在瘢痕疙瘩组织的活化成纤维细胞及其COL1A1/2+ Fibroblast亚群中高表达。在RNA测序数据集和基因芯片数据集中，PDGFA在瘢痕疙瘩组织中的表达水平高于正常瘢痕组织（P<0.05）；汇总受试者工作特征曲线分析结果显示，PDGFA表达水平在区分瘢痕疙瘩和正常瘢痕中具有较高的综合效能（曲线下面积为0.74）；在单个数据集分析中，GSE158395、GSE246562数据集显示PDGFA在瘢痕疙瘩组织中的表达水平高于正常瘢痕组织（P<0.05），且其诊断效能较高（曲线下面积分别为 0.929、0.967）。在临床病例样本中，PDGFA在瘢痕疙瘩组织中高表达（P<0.05），其对瘢痕疙瘩具有较好的诊断效能（曲线下面积为0.795）。共筛选出198个交集基因，这些基因主要富集于核苷酸糖的生物合成、氨基糖与核苷酸糖代谢、p53信号通路等通路，并与肌动蛋白结合、肌动蛋白丝结合、细胞外基质结构成分等分子功能，骨骼发育和胶原纤维组织等生物过程，以及细胞⁃基质连接和黏着斑等细胞组分密切相关。分子对接分析结果显示奈比洛尔与PDGFA蛋白的结合活性最佳，其Vina评分为-9.0 kcal/mol。结论 PDGFA可以促进成纤维细胞活化并驱动瘢痕疙瘩形成，其有望成为瘢痕疙瘩早期诊断和治疗的新靶点。

Objective To investigate the expression characteristics of platelet⁃derived growth factor A (PDGFA) in keloid tissues and its pro⁃fibrotic mechanism. Methods Keloid⁃related single⁃cell RNA sequencing datasets from the GEO database were retrieved to analyze PDGFA expression and associated cellular features in keloid tissues. RNA sequencing datasets and microarray datasets containing keloid and normal scar tissue samples were retrieved and downloaded from GEO, SRA, and ArrayExpress databases to assess PDGFA expression in keloid tissues and diagnostic efficiency for keloid. Samples (13 normal scars and 12 keloids) were collected from a hospital for gene expression sequencing to validate PDGFA expression in clinical samples and diagnostic efficiency on keloid. Intersection analysis was performed on the genes highly expressed in keloid tissues of RNA sequencing datasets and microarray datasets, the genes highly expressed in keloid tissues of clinical cases, and the genes co⁃expressed with PDGFA. For these intersection targets, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and Gene Ontology functional enrichment analysis were conducted. Five potential PDGFA⁃targeting small⁃molecule drugs were screened using DSigDB database and GSEA software, followed by molecular docking to evaluate binding affinity with PDGFA proteins. Results In single cell RNA sequencing datasets, PDGFA was highly expressed in activated fibroblasts and its COL1A1/2+ Fibroblast subpopulations of keloid tissues. RNA sequencing/microarray datasets revealed a higher PDGFA expression in keloid tissues than normal scar tissues (P<0.05). Summary receiver operating characteristic curve analysis indicated strong comprehensive efficiency (area under the curve=0.74) of PDGFA expression in discriminating keloid tissues and normal scar tissues. Individual datasets (GSE158395, GSE246562) confirmed elevated PDGFA expression in keloid tissues than in normal scar tissues (P<0.05), with high diagnostic efficiency (areas under the curve=0.929, 0.967). Clinical samples validated PDGFA high⁃expression in keloid tissues (P<0.05), with a favorable diagnostic efficiency on keloid (area under the curve=0.795). A total of 198 intersection genes were screened and enriched in pathways such as nucleotide sugar biosynthesis, amino sugar and nucleotide suagr metabolism, p53 signaling pathway, in molecular functions such as actin binding, actin filament binding, and extracellular matrix structural constituent, in biological processes such as skeletal development, collagen fibril organization, and in cellular components such as cell⁃matrix junctions, focal adhesions. Molecular docking analysis revealed that nebivolol showed the optimal binding affinity to PDGFA protein (Vina score: ⁃9.0 kcal/mol). Conclusion PDGFA promotes fibroblast activation and keloid formation, serving as a novel early diagnostic and therapeutic target for keloid.