Fig 2: ORM2 deficiency contributes to AP progression. (A) The serum amylase level from ORM2WT and ORM2KO mice subjected to intraperitoneal injection of vehicle or caerulein (n=6 per group). (B) The serum IL-6 from ORM2WT and ORM2KO mice subjected to intraperitoneal injection of vehicle or caerulein (n=6 per group). (C) The serum TNF-α from ORM2WT and ORM2KO mice subjected to intraperitoneal injection of vehicle or caerulein (n=6 per group). (D) Representative HE staining and histological scores of the pancreatic tissues in ORM2WT and ORM2KO mice subjected to intraperitoneal injection of vehicle or caerulein (n=6 per group). Scale bar: 50 µm. Data are presented as mean ± SEM. The groups were compared using one-way ANOVA with Tukey’s post hoc test (****, P<0.0001). ANOVA, analysis of variance; AP, acute pancreatitis; IL-6, interleukin-6; HE, hematoxylin and eosin; SEM, standard error of the mean; TNF-α, tumor necrosis factor-alpha.

Fig 3: Reduced pancreatic ORM2 expression in AP. (A) Scatterplots showing log2 transformation of the normalized blood ORM1 in patients with MAP (n=57) and healthy controls (n=32). (B) Scatterplots showing log2 transformation of the normalized blood ORM2 in patients with MAP (n=57) and healthy controls (n=32). (C) The serum ORM in control and AP mice (n=6 per group). (D) Immunoblotting of ORM1 and ORM2 in serum from control and AP mice (n=6 per group). (E) Immunoblotting and quantitative analysis of ORM1 and ORM2 in pancreas from control and AP mice (n=6 per group). (F) Immunoblotting and quantitative analysis of ORM1 and ORM2 in liver from control and AP mice (n=6 per group). Data are presented as mean ± SEM. The groups were compared using unpaired two-tailed student’s t-test (*, P<0.05; ***, P<0.001; ****, P<0.0001). AP, acute pancreatitis; MAP, mild acute pancreatitis; ORM, orosomucoid; SEM, standard error of the mean.

Fig 4: ORM2 inhibits pancreatic inflammation by preventing premature trypsinogen activation. (A) Volcano plot of differentially expressed proteins between AP and control groups. (B) Volcano plot of differentially expressed proteins between AP + ORM2 and AP groups (ORM2, 100 µg/kg). (C) The mRNA levels of Spink1 in control and AP mice following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). (D) The mRNA levels of Prss2 in control and AP mice following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). (E) The trypsin activity in pancreatic tissues from control and AP mice following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). Data are presented as mean ± SEM. The groups were compared using one-way ANOVA with Tukey’s post hoc test (ns, not significant; *, P<0.05; **, P<0.01; ****, P<0.0001). ANOVA, analysis of variance; AP, acute pancreatitis; OH, high-dose ORM2; OL, low-dose ORM2; SEM, standard error of the mean.

Fig 5: Exogenous ORM2 attenuates acinar cell injury in vitro. (A) The mRNA level of Il-1β in control and CCK-induced primary acinar cells following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). Low-dose ORM2: 5 µg/mL, high-dose ORM2: 10 µg/mL. (B) The mRNA level of Il-6 in control and CCK-induced primary acinar cells following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). (C) The mRNA level of Tnf-α in control and CCK-induced primary acinar cells following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). (D) The amylase level in control and CCK-induced primary acinar cells following treatment with vehicle, low-dose ORM2, or high-dose ORM2 (n=6 per group). Data are presented as mean ± SEM. The groups were compared using one-way ANOVA with Tukey’s post hoc test (ns, not significant; **, P<0.01; ****, P<0.0001). ANOVA, analysis of variance; CCK, cholecystokinin; SEM, standard error of the mean.