雨蛙素诱导急性胰腺炎中胰腺再生修复的损伤程度依赖性差异研究

Injury severity-dependent differences in pancreatic regeneration and repair in cerulein-induced acute pancreatitis

摘要:

背景与目的 急性胰腺炎（AP）再生修复过程具有显著异质性，其与初始损伤程度的关系尚缺乏系统阐明。本研究构建不同损伤强度的AP小鼠模型，探讨胰腺再生修复的病理学特征及其损伤程度依赖性规律。方法 采用雨蛙素腹腔注射建立AP小鼠模型，分为7次注射组（轻度）和10次注射组（中重度）。于造模后第1、3、5、7天取材，通过HE染色及病理评分评估胰腺损伤程度；免疫荧光检测腺泡-导管化生（ADM）标志物（CK19、SOX9）及巨噬细胞极化标志物（F4/80、iNOS、CD206）；Masson染色及α-SMA免疫组化评估纤维化水平；Ki-67免疫组化分析细胞增殖活性。结果 10次注射组胰腺损伤显著重于7次注射组（P<0.05），表现为弥漫性受累及修复延迟。ADM反应显著增强，CK19及SOX9表达明显升高；巨噬细胞浸润增加并以M1型极化为主；纤维化沉积（胶原体积分数及α-SMA表达）显著加重（P<0.05）。细胞增殖呈“早期增强、峰值延迟”特征。相比之下，7次注射组损伤局限、修复较快，各项病理改变程度较轻。结论 雨蛙素不同注射强度可诱导AP小鼠呈现梯度化损伤表型，胰腺再生修复过程具有明确的损伤程度依赖性异质性，涉及ADM、巨噬细胞极化、纤维化及细胞增殖的协同调控。

Abstract:

Background and Aims Pancreatic regeneration following acute pancreatitis (AP) exhibits marked heterogeneity, which is closely related to the initial injury severity but remains insufficiently characterized. This study aimed to investigate the pathological features of pancreatic regeneration and repair under different injury severities.Methods Cerulein-induced AP mouse models were established using two regimens: 7 injections (mild injury) and 10 injections (moderate-to-severe injury). Pancreatic tissues were collected on days 1, 3, 5, and 7. Histopathological injury was evaluated using HE staining and scoring. Immunofluorescence was used to assess acinar-to-ductal metaplasia (ADM) markers (CK19, SOX9) and macrophage polarization markers (F4/80, iNOS, CD206). Fibrosis was evaluated by Masson staining and α-SMA immunohistochemistry. Cell proliferation was assessed by Ki-67 staining.Results The 10-injection group exhibited significantly more severe pancreatic injury and delayed repair compared with the 7-injection group (P<0.05). ADM was markedly enhanced, with increased expression of CK19 and SOX9. Macrophage infiltration was elevated with a predominance of M1 polarization. Fibrosis was significantly aggravated, as evidenced by increased collagen deposition and α-SMA expression (P<0.05). Cell proliferation showed a pattern of early activation with a delayed peak. In contrast, the 7-injection group showed localized injury and rapid recovery with milder pathological changes.Conclusion Different cerulein injection regimens induce graded injury phenotypes in AP mice. Pancreatic regeneration exhibits injury severity-dependent heterogeneity, involving coordinated regulation of ADM, macrophage polarization, fibrosis, and cell proliferation.