HMG Box-Containing Protein 1 (HBP1) Protects Against Pancreatic Injury in Acute Pancreatitis but Promotes Neoplastic Progression

Background & Aims Pancreatitis is an inflammatory disease of the exocrine pancreas and a known risk factor for pancreatic ductal adenocarcinoma (PDAC). Previously, we identified HMG- box transcription factor 1 (HBP1) as a potential master transcription factor (TF) in the early progression of PDAC, with its expression associated with poor patient survival, underscoring its significance in pancreatic disease. However, the functional role of HBP1 in the onset and progression of acute pancreatitis (AP) remains unknown. Methods We examined HBP1 expression in human pancreatitis samples and a cerulein-induced AP mouse model. Pancreatic-specific conditional HBP1 knockout mice, with or without an oncogenic Kras mutation, were generated and compared to their littermate controls. Spatial transcriptomics and multiplexed protein assays, histological analysis, and immunostaining were utilized to characterize pathological changes. Findings from mouse models were validated using inducible HBP1-overexpressing human pancreatic ductal epithelial cells. Results HBP1 was upregulated in pancreatic exocrine cells in human chronic pancreatitis and mouse acute pancreatitis, with its expression in human chronic pancreatitis correlating with cancer presence. Pancreatic HBP1 ablation disrupted acinar homeostasis by impairing autophagic flux and exacerbating inflammation following injury. In the presence of oncogenic KRAS, HBP1 ablation delayed the formation of pancreatic intraepithelial neoplasia (PanIN), the precursor to PDAC, and slowed its progression to higher-grade lesions. Conclusions HBP1 upregulation in pancreatitis mitigates pancreatic inflammatory injury; however, in the presence of oncogenic KRAS, it facilitates PanIN progression. Thus, HBP1 serves as a critical regulator in both pancreatitis and early pancreatic neoplasia, representing a potential therapeutic target for intervening pancreatitis and PanIN progression. Overall design: Spatial transcriptomic analysis was performed on pancreata from three HBP1 WT and three HBP1 CKO mice on days 1 and 2 post-cerulein treatment. Pancreatitis areas were mounted on 10x Genomics Visium slides, with 5000 barcoded 55 µm spots capturing 1–10 cells per spot, each containing millions of probes for 20,551 mouse genes via CytAssist28. Sequencing (25k read pairs/spot) generated FASTQ files, which were mapped to H&E images and feature-barcode matrices using Spaceranger.

研究背景与目的：胰腺炎是发生于外分泌胰腺的炎症性疾病，同时也是胰腺导管腺癌（pancreatic ductal adenocarcinoma, PDAC）的明确危险因素。既往本团队已证实，高迁移率族盒转录因子1（HMG-box transcription factor 1, HBP1）是胰腺导管腺癌早期进展过程中的潜在主转录因子（transcription factor, TF），其表达水平与患者不良预后相关，凸显了其在胰腺疾病中的重要意义。然而，HBP1在急性胰腺炎（acute pancreatitis, AP）的发生与进展过程中所发挥的功能尚不清楚。
方法：本研究检测了人胰腺炎样本及雨蛙素诱导的急性胰腺炎小鼠模型中HBP1的表达水平。构建了携带或不携带致癌性KRAS突变的胰腺特异性条件性HBP1敲除小鼠，并以其同窝野生型小鼠作为对照。通过空间转录组学、多重蛋白检测、组织学分析及免疫染色等技术，对胰腺的病理变化进行表征。同时利用诱导型过表达HBP1的人胰腺导管上皮细胞，对小鼠模型的研究结果进行验证。
结果：人慢性胰腺炎及小鼠急性胰腺炎的胰腺外分泌细胞中均存在HBP1表达上调，且人慢性胰腺炎组织中HBP1的表达水平与癌变状态呈正相关。胰腺特异性敲除HBP1可通过损伤自噬流、加重损伤后的炎症反应，破坏腺泡稳态。在携带致癌性KRAS突变的背景下，敲除HBP1可延缓胰腺上皮内瘤变（pancreatic intraepithelial neoplasia, PanIN，PDAC的前驱病变）的形成，并阻滞其向高级别病变进展。
结论：胰腺炎状态下HBP1的表达上调可减轻胰腺炎症损伤；但在致癌性KRAS突变存在的情况下，HBP1可促进胰腺上皮内瘤变的进展。综上，HBP1是胰腺炎及胰腺早期肿瘤发生过程中的关键调控因子，有望成为干预胰腺炎及胰腺上皮内瘤变进展的潜在治疗靶点。
整体实验设计：在雨蛙素造模后第1天和第2天，分别对3只HBP1野生型（WT）小鼠及3只HBP1条件性敲除（CKO）小鼠的胰腺组织进行空间转录组分析。将胰腺炎病灶固定于10x Genomics Visium芯片上，采用5000个带条形码的55微米捕获斑点，每个斑点可覆盖1~10个细胞，通过CytAssist28技术搭载可靶向20551个小鼠基因的数百万条探针。以每个斑点25k读对的测序深度进行测序，生成FASTQ文件，随后通过Spaceranger软件将测序数据匹配至H&E染色图像及特征-条形码矩阵。