Ghrelin通过GHSR1a-EGFR-ERK途径调控胰腺Lgr5+细胞分化参与急性胰腺炎后腺泡细胞再生的机制研究

Incomplete pancreatic repair after acute pancreatitis (AP) may prolong the AP course and increase the incidence of exocrine pancreatic insufficiency after AP.LGR5+ cells increased dramatically after pancreatic injury and can be cultured into pancreatic organoid with multipotent stem cell characterization . We found that ghrelin can promote the expression of LGR5 and Amy2 (acinar cell marker) in pancreatic organoid. Besides, the concentration of serum ghrelin increased in repair phase in AP patients and AP mice model. Ghrelin can promote the repair progress by GHSR1a-EGFR-ERK pathway in many injury repair model including duodenal ulcer, which was co-expressed with LGR5 in pancreatic organoid. Therefore, we hypothesized Ghrelin regulates differentiation of pancreatic LGR5+ cell by activating GHSR1a-EGFR-ERK pathway to promote acinar cell regeneration after Acute pancreatitis. We will use 3D cultures of pancreatic organoid, AP mice model, flow cytometry, immunofluorescence, Rt-PCR, Western-blot, EDU-click-it and etc.to explore the hypothesis and the mechanism of pancreatic injury repair after AP and provide useful target for the treatment of AP.

急性胰腺炎（AP）后胰腺坏死修复不佳可导致病程延长，后期外分泌功能不全发生增加。LGR5+细胞在胰腺损伤后显著增加，并在体外可培养成具有多能干细胞特性的胰腺类器官。我们发现Ghrelin在胰腺类器官中可促进LGR5和腺泡细胞标记物Amy2表达增加。在AP患者和小鼠模型中，血清Ghrelin浓度在修复期显著增加。而Ghrelin在十二指肠溃疡等多种损伤模型中可通过GHSR1a-EGFR-ERK途径促进组织损伤修复，其受体GHSR-1a在胰腺类器官中与LGR5共表达。因此我们假设Ghrelin可能通过GHSR1a-EGFR-ERK途径调控LGR5+细胞分化参与AP后腺泡细胞再生，并使用3D胰腺类器官及AP动物模型，通过流式细胞、免疫荧光、Rt-PCR、Western-blot 、EDU-click-it方法等技术，验证上述假设，探索AP后胰腺损伤修复的新机制和治疗新靶点。

急性胰腺炎（AP）后胰腺坏死修复不佳可导致病程延长，胰腺外分泌功能不全（EPI）发生增加。促进AP后胰腺组织尤其是腺泡细胞的修复是减少外分泌功能不全发生、提高疾病后生活质量的重要目标。本研究拟通过诱导小鼠AP模型后，给予ghrelin受体GHS-R激动剂或拮抗剂观察损伤腺泡细胞的修复变化，应用体外长时间培养原代腺泡细胞探索激动或抑制GHS-R影响AP后损伤腺泡细胞修复的潜在机制。研究内容和假设：①观察血清ghrelin水平在AP炎症和修复期动态变化；②ghrelin受体GHS-R在AP时基因及蛋白水平变化；③体内体外应用GHS-R激动剂MK-677可能减轻小鼠AP炎症、减少腺泡细胞死亡、促进损伤的腺泡细胞修复；④GHS-R拮抗剂JMV2959可能延缓AP小鼠损伤的胰腺腺泡细胞修复；⑤GHS-R激动剂MK-677促进损伤腺泡细胞修复的具体机制。研究结果将为AP后胰腺外分泌功能不全提供可能的治疗靶点。