Decreased inflammation and improved survival with recombinant human activated protein C treatment in experimental acute pancreatitis.

HYPOTHESIS: Drotrecogin alfa (activated), the pharmacologic form of activated protein C and the first Food and Drug Administration-approved drug for treatment of severe sepsis, is beneficial in experimental acute pancreatitis (AP). DESIGN: Animal study. SETTING: Laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Mild (intravenous cerulein) or severe (intravenous cerulein plus intraductal glycodeoxycholic acid) AP was induced in 72 rats, and coagulation evaluated. Rats with severe AP were randomized to treatment with drotrecogin alfa (activated), 100 microg/kg per hour, or isotonic sodium chloride. MAIN OUTCOME MEASURES: Histologic scoring of pancreatic necrosis, inflammation of the pancreas and lung (measured by myeloperoxidase concentration), coagulation measures, and 24-hour survival. RESULTS: Severe consumptive coagulopathy, hemoconcentration, and leukocytosis were observed 6 hours after induction of severe AP, but not in mild AP. Treatment of AP with drotrecogin did not worsen coagulation measures. Although the degree of pancreatic necrosis was comparable in treated and untreated animals with severe AP, drotrecogin significantly reduced myeloperoxidase levels in the pancreas (P = .009) and lungs (P = .03). The 24-hour survival in severe AP was markedly improved in animals treated with drotrecogin (86% vs 38%; P = .05). CONCLUSIONS: Animals with severe AP have severe consumptive coagulopathy, but administration of drotrecogin alfa (activated), 100 microg/kg per hour, does not worsen coagulation abnormalities. Drotrecogin treatment reduces inflammation in the pancreas and lungs and significantly improves survival. These results encourage clinical investigation of drotrecogin in the treatment of severe AP.

Troponin I peptide (Glu94-Leu123), a cartilage-derived angiogenesis inhibitor: in vitro and in vivo effects on human endothelial cells and on pancreatic cancer.

Several inhibitors of angiogenesis have been identified in bovine and shark cartilage. One of them is troponin I, which is the molecule responsible for the inhibition of the actomyosin ATPase during muscle contraction. In this study we sought to investigate if the active site of troponin I (peptide Glu94-Leu123; pTnI) is also the one responsible for the antiangiogenic properties of this protein. The effects of pTnI on endothelial cell tube formation and endothelial cell division were investigated using human umbilical vein endothelial cells, Matrigel, light microscopy, carboxyfluorescein diacetate, succinimidyl esterlabeling, and flow cytometry. Its effects on induction of ICAM-1 and production of vascular endothelial growth factor by pancreatic cancer cells (CAPAN-1) were also investigated, as was its efficacy in a mouse model of pancreatic cancer metastases. Our results show that concentrations as low as 1 pg/ml of pTnI significantly inhibit endothelial cell tube formation, and that endothelial cell division was inhibited at 96 hours by 3 microg/ml pTnI (P=0.0001). No effects were seen using troponin peptide 124-181 as a control. pTnI-treated supernatant from the pancreatic cancer cell line CAPAN-1 downregulated ICAM-1 expression on human umbilical vein endothelial cells up to 10 ng/ml pTnI, and a significant reduction in vascular endothelial growth factor production was seen by treating CAPAN-1 cells with up to 1 microg/ml pTnI. After intrasplenic injection of CAPAN-1 cells, mice treated with pTnI had fewer liver metastases compared to control mice (liver/body weight 5.5 vs. 11.1; P=0.03). The active region of troponin I is the one responsible for its antiangiogenic effect. The mechanism of action of this peptide is probably multifactorial.

Hedgehog is an early and late mediator of pancreatic cancer tumorigenesis.

Hedgehog signalling--an essential pathway during embryonic pancreatic development, the misregulation of which has been implicated in several forms of cancer--may also be an important mediator in human pancreatic carcinoma. Here we report that sonic hedgehog, a secreted hedgehog ligand, is abnormally expressed in pancreatic adenocarcinoma and its precursor lesions: pancreatic intraepithelial neoplasia (PanIN). Pancreata of Pdx-Shh mice (in which Shh is misexpressed in the pancreatic endoderm) develop abnormal tubular structures, a phenocopy of human PanIN-1 and -2. Moreover, these PanIN-like lesions also contain mutations in K-ras and overexpress HER-2/neu, which are genetic mutations found early in the progression of human pancreatic cancer. Furthermore, hedgehog signalling remains active in cell lines established from primary and metastatic pancreatic adenocarcinomas. Notably, inhibition of hedgehog signalling by cyclopamine induced apoptosis and blocked proliferation in a subset of the pancreatic cancer cell lines both in vitro and in vivo. These data suggest that this pathway may have an early and critical role in the genesis of this cancer, and that maintenance of hedgehog signalling is important for aberrant proliferation and tumorigenesis.

Perioperative matrix metalloproteinase inhibition therapy does not impair wound or anastomotic healing.

Matrix metalloproteinases (MMPs) catalyze the degradation of collagen and extracellular matrix. They play a role in pathologic states including malignancy, in which they facilitate invasion and metastasis. MMP inhibition has been shown to block neoplastic invasion and improve survival in animal models of malignancy. Concern about the effects of MMP inhibitors on wound and anastomotic healing may limit their potential use in the perioperative period to prevent local and systemic showering of cancer cells from surgical manipulation. We sought to assess the safety of perioperative administration of an MMP inhibitor (BB-94) with respect to skin and bowel healing in a rat model. Absorption of BB-94 was confirmed through high-pressure liquid chromatography and mass spectroscopy of sera from treated animals. Bowel bursting pressure in all animals increased almost 10-fold between 4 and 14 days. Two-way analysis of variance showed no significant difference in bowel bursting pressure between control and treatment animals over time. There was a significant increase in the collagen content of skin specimens of all animals combined between 4 and 28 days. Similarly, all animals showed an increase in bowel collagen between 4 and 28 days. There was no significant difference in skin or bowel collagen concentrations between control and treatment animals over time. Perioperative treatment with MMP inhibition does not impair wound or enteric healing in a rat model of laparotomy and small bowel resection. MMP inhibitors are safe for use as adjuvant therapy after resection for cancer.

Matrix metalloproteinase-9 promotes neutrophil migration and alveolar capillary leakage in pancreatitis-associated lung injury in the rat.

BACKGROUND & AIMS: In pancreatitis-associated lung injury, neutrophils (PMN) access the lung by migration through endothelial basement membranes. We hypothesize that degeneration of the basement membrane by specific PMN-produced matrix metalloproteinases (MMPs) may facilitate this process. METHODS: Mild or severe pancreatitis was induced in rats and the consequent pulmonary injury characterized. MMP-2 and MMP-9 activity in supernatant of PMN cultures and homogenates of lungs were assessed by zymography and Western blot. Congruence of PMN and MMP expression in lung tissue was evaluated by neutrophil depletion and fluorescent immunohistochemistry (IHC). The contribution of MMPs to PMN transmigration and lung injury was tested with the MMP inhibitor batimastat (BB-94) in vitro (PMN transmigration across matrigel chambers) and in vivo (myeloperoxidase activity and Evans blue in broncho-alveolar lavage fluid). RESULTS: MMP-9 was highly expressed in lungs and supernatant of neutrophil cultures in severe pancreatitis, and, to a lesser degree, in mild pancreatitis. Lung IHC showed colocalization of MMP-9 and PMN. PMN depletion simultaneously reduced neutrophil infiltration and MMP-9 levels in lung tissue. Trypsin, interleukin 1 beta, and tumor necrosis factor (TNF)-alpha all potently stimulated MMP-9 release from PMN. BB-94 significantly reduced TNF-alpha-induced PMN transmigration across matrigel and ameliorated transendothelial PMN migration and protein leak in severe pancreatitis. CONCLUSIONS: MMP-9 secretion by PMN can be stimulated by trypsin and proinflammatory cytokines and increases in pancreatitis in proportion to its severity. MMP inhibition reduces PMN transmigration and reduces resultant alveolar-capillary leakage. These findings suggest an important role for MMP-9 from PMN in the pathogenesis of pancreatitis-associated lung injury.