Li Hui, Ma Murong, Wen Wen, Leidinger Mariah R, Hu Di, Zhang Zuohui, Lin Hong, Luo Jia
bioRxiv. 2025 Aug 2:2025.07.31.667953. doi: 10.1101/2025.07.31.667953.
Acute pancreatitis (AP) is a complex and potentially severe inflammatory disorder of the pancreas and is one of the most common causes of gastrointestinal hospitalization. Although environmental risk factors such as alcohol and gallstones are well recognized, only a subset of exposed individuals develop AP, suggesting that intrinsic factors, including genetic susceptibility, influence disease onset and progression. Endoplasmic reticulum (ER) stress has emerged as a key mechanism in AP pathogenesis, because ER is essential for protein synthesis, folding, degradation and secretion (proteostasis). Mesencephalic astrocyte-derived neurotrophic factor (MANF), an ER stress-inducible protein highly expressed in the pancreas, plays a critical role in maintaining proteostasis, yet its involvement in AP remains unclear. To investigate the functional role of MANF in AP, we generated pancreas-specific MANF knockout (MANF-KO) mice using the Cre/loxP system and subjected them to moderate experimental AP, that is caerulein- or alcohol-induced AP in mice. In the caerulein model, MANF deficiency exacerbated pancreatic injury in both sexes, as indicated by increased apoptosis (cleaved caspase-3, caspase-12), ER stress markers (eIF2α, p-eIF2α, GRP78), inflammation (IL-6, TNFα), regenerative activity (Ki67), and pancreatic lipase levels. Notably, male MANF-KO mice exhibited enhanced inflammation (HMGB1), macrophage infiltration (CD68), and oxidative stress (DNP, HNE), which were not observed in females. In the alcoholic AP model, both male and female MANF-KO mice showed increased ER stress (p-IRE1, p-eIF2α, GRP78), apoptosis, inflammation, macrophage infiltration, regeneration, and lipase levels, whereas elevated HMGB1 expression and oxidative stress again predominantly occurred in male MANF-KO mice. Together, these findings reveal a critical and sex-specific role for MANF in regulating pancreatic stress responses and inflammatory injury, supporting its potential contribution as a genetic factor in AP pathogenesis.
急性胰腺炎（AP）是一种复杂且可能严重的胰腺炎症性疾病，是胃肠道住院治疗的最常见原因之一。尽管酒精和胆结石等环境危险因素已广为人知，但只有一部分暴露个体发生AP，这表明包括遗传易感性在内的内在因素会影响疾病的发生和发展。内质网（ER）应激已成为AP发病机制中的关键机制，因为内质网对于蛋白质合成、折叠、降解和分泌（蛋白质稳态）至关重要。中脑星形胶质细胞衍生的神经营养因子（MANF）是一种在胰腺中高度表达的内质网应激诱导蛋白，在维持蛋白质稳态中起关键作用，但其在AP中的作用仍不清楚。为了研究MANF在AP中的功能作用，我们使用Cre/loxP系统构建了胰腺特异性MANF基因敲除（MANF-KO）小鼠，并使其遭受中度实验性AP，即小鼠中由蛙皮素或酒精诱导的AP。在蛙皮素模型中，MANF缺乏加剧了两性的胰腺损伤，表现为凋亡增加（裂解的半胱天冬酶-3、半胱天冬酶-12）、内质网应激标志物（eIF2α、磷酸化eIF2α、GRP78）、炎症（IL-6、TNFα）、再生活性（Ki67）和胰腺脂肪酶水平升高。值得注意的是，雄性MANF-KO小鼠表现出增强的炎症（HMGB1）、巨噬细胞浸润（CD68）和氧化应激（二硝基苯酚、羟壬烯醛），而雌性小鼠未观察到这些情况。在酒精性AP模型中，雄性和雌性MANF-KO小鼠均表现出内质网应激增加（磷酸化IRE1、磷酸化eIF2α、GRP78）、凋亡、炎症、巨噬细胞浸润、再生和脂肪酶水平升高，而HMGB1表达升高和氧化应激再次主要发生在雄性MANF-KO小鼠中。总之，这些发现揭示了MANF在调节胰腺应激反应和炎症损伤中的关键且性别特异性作用，支持其作为AP发病机制中遗传因素的潜在作用。
