Depleting apolipoprotein C3 alleviates acute pancreatitis in hamsters but not in mice

Figure 4 Loss of apolipoprotein C3 alleviates caerulein-induced acute pancreatitis under high-fat diet conditions in hamsters. A: Schematic of the experimental protocol: 8-week-old male hamsters were fed a high-fat diet (HFD) for 2 months. At 16 weeks of age, they received hourly intraperitoneal injections of caerulein (50 μg/kg) for a total of 10 times and were sacrificed 24 hours after the first injection; B and C: Plasma triglyceride (B) and NEFA (C) levels were measured under CD and HFD conditions in the indicated treatment groups, n = 4-6; D and E: Plasma amylase (D) and lipase (E) activities were assessed across treatment groups; F: Representative hematoxylin and eosin-stained pancreatic tissue sections from WT and apolipoprotein C3 knockout (ApoC3^-/-) hamsters; enlarged views are shown below, n = 4-6; G-J: Histological scoring of pancreatic tissue from WT and ApoC3^-/- hamsters, including oedema (G), inflammation (H), necrosis (I), and total pathology score (J), n = 4-6; K-O: Relative mRNA expression levels of inflammation- and apoptosis-related genes in pancreatic tissue from WT and ApoC3^-/- hamsters, including Tnf-α (K), Il-6 (L), Nlrp3 (M), Bax (N), and Il-18 (O) , n = 4; P and Q: Representative immunofluorescence staining of MPO (green) with DAPI (blue) nuclear counterstaining (P), and quantification of the relative MPO-positive area in pancreatic tissue of WT and ApoC3^-/- hamsters (Q). White arrowheads indicate MPO-positive staining; scale bar: 75 μm; R and S: Representative immunofluorescence staining of CD68 (green) with DAPI (blue) (R), and quantification of the relative CD68-positive area in the same groups (S). White arrowheads indicate CD68-positive staining; scale bar: 100 μm. For each group, three animals were used; two fields of view per animal were quantified as independent observations (n = 6 per group). Data are presented as the mean ± SEM. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, and ^dP < 0.0001. ApoC3: Apolipoprotein C3; ApoC3^-/-: Apolipoprotein C3 knockout; AP: Acute pancreatitis; CD: Chow diet; HFD: High-fat diet; TG: Triglyceride; NEFA: Non-esterified fatty acid; WT: Wild type; Tnf-α: Tumor necrosis factor-α; Il-6: Interleukin-6; Nlrp3: NLR family pyrin domain containing 3; Bax: BCL2-associated X protein; Il-18: Interleukin-18; DAPI: 4’,6-diamidino-2-phenylindole; MPO: Myeloperoxidase; CD68: Cluster of differentiation 68.