The plasminogen activator/plasmin system is up-regulated after acute necrotizing pancreatitis in human beings

Prognostic role of suPAR in acute pancreatitis: A protocol for systematic review

BACKGROUND

Acute pancreatitis (AP) is a common emergency condition with high morbidity, mortality, and socio-economic impact. Soluble urokinase plasminogen activator receptor (suPAR) is a potential biomarker for AP prognosis. This study systematically reviews the literature on suPAR's prognostic roles in assessing AP severity, organ failure, mortality, and other pathological markers.

METHODS

A comprehensive search of 5 databases up to March 19, 2023, was conducted, selecting cohort studies that examined suPAR's relationship with AP outcomes. Outcome variables included AP severity, organ failure, mortality, hospital stay length, and suPAR's association with other inflammatory markers. Our paper has been registered on Prospero (ID: CRD42023410628).

RESULTS

Nine prospective observational studies with 1033 AP patients were included. Seven of eight studies found suPAR significantly elevated in severe acute pancreatitis (P < .05). Four studies showed suPAR effectively predicted organ failure risk, and 4 studies concluded suPAR significantly predicted mortality (P < .05). The review had no high-risk studies, enhancing credibility.

CONCLUSION

suPAR is a valuable prognostic marker in AP, significantly predicting severity, organ failure, hospital stay length, and mortality. Further large-scale studies are needed to explore suPAR's role in other clinical outcomes related to AP disease course, to establish it as a mainstay of AP prognosis.

Persistent fibrinolysis shutdown is associated with increased mortality in traumatic pancreatic injury

PURPOSE

The features of fibrinolytic system modifications and their relationship with prognosis are still unknown in traumatic pancreatic injury. The object of this prospective cohort research was to identify fibrinolytic characteristics in patients with pancreatic trauma and to identify the correlation to mortality.

METHOD

A prospective screening of traumatic pancreatic injury patients was done for five years. The fibrinolytic status of patients was determined by thromboelastography (TEG). The percentage reduction in clot strength 30 min (LY30) after the time of maximal clot strength was utilized to distinguish the fibrinolytic phenotype of individuals, including fibrinolytic shutdown (SD), physiologic fibrinolysis (PHYS) and hyperfibrinolysis (HF). Two cohorts, transient fibrinolytic shutdown (TSD) and persistent fibrinolytic shutdown (PSD), were divided according to whether fibrinolytic shutdown persisted within one week. Demographics, injury severity, characteristics of pancreatic injury, treatment, and outcomes were compared.

RESULT

A total of 180 cases enrolled, aged 42(interquartile range 32-51) years, 88% males, 97% were blunt trauma. The median ISS was 19(IQR 10-25), and 76% were AAST grade III to V (high-grade). At admission, there were 159 cases of SD (88%), 15 cases of PHYS (8%) while 6 cases of HF (3%). Of these, the TSD cohort included 54 patients (34%), while the PSD cohort included 105 patients (66%). Compared with the TSD cohort, the PSD cohort had more severe injury (ISS 21[IQR 12-27] vs 16[IQR 9-22], p = 0.006) and a higher proportion of AAST high-grade (83% vs 67%, p = 0.035). Persistent fibrinolytic shutdown was associated with operative treatment (odds ratio [OR] 3.111; 95%CI 1.146-8.447; p = 0.026), associated intra-abdominal injury (OR 8.331; 95% CI 1.301-53.336; p = 0.025) and admission LY30 (OR 0.016; 95% CI 0.002 - 0.120; p < 0.001). It was an independent predictor of mortality (adjusted odds ratio [AOR] 4.674; 95% CI 1.03 to 21.14; p = 0.045).

CONCLUSION

Fibrinolytic shutdown especially persistence of this phenotype is more common in traumatic pancreatic injury than PHYS and HF, which related with mortality. Risk factors including LY30 at admission, intra-abdominal injury and operative treatment were associated with the persistent fibrinolytic shutdown. Sheltered the patients from these risk factors seems to be beneficial, which need to be confirmed by further large-scale studies.

Evaluation of Plasma Urokinase-Type Plasminogen Activator Receptor (UPAR) in Patients With Chronic Hepatitis B, C and Non-Alcoholic Fatty Liver Disease (NAFLD) as Serological Fibrosis Marker

BACKGROUND/AIMS

Progressive hepatic fibrosis is the main predictor of outcome and prognosis in chronic liver diseases. The importance of the coagulation cascade has been defined in liver fibrosis; however, the role of the fibrinolytic pathway has not been clear yet. We aimed to evaluate the association between the plasma levels of soluble urokinase Plasminogen Activator Receptor (uPAR) and the severity of liver fibrosis in chronic hepatitis B, C and Non-Alcoholic Fatty Liver Disease (NAFLD).

METHODS

96 chronic hepatitis B, 22 chronic hepatitis C and 11 NAFLD patients together with 47 healthy controls were enrolled in the study. uPAR plasma levels were detected by Enzyme-Linked Immunosorbent Assay (ELISA) method.

RESULTS

The plasma levels of uPAR in patients with chronic hepatitis B and C significantly exceeded those of healthy controls (P < 0.001) while mean uPAR levels in patients with NAFLD were not different from healthy controls. Mean uPAR levels in chronic viral hepatitis patients with F1-F3 fibrosis and F4-F6 fibrosis were higher than those of control group (P < 0.001). Mean uPAR level in patients with F4-F6 fibrosis was significantly higher than that of patients with F1-F3 fibrosis (P < 0.001).

CONCLUSION

This is the first study that investigated uPAR as a fibrosis marker in NAFLD and chronic hepatitis B patients. It is suggested that plasma levels of uPAR are closely related to the fibrosis stage in chronic hepatitis B and C and that uPAR might be a noninvasive marker of liver fibrosis.

Serum Urokinase-Type Plasminogen Activator Receptor Does Not Outperform C-Reactive Protein and Procalcitonin as an Early Marker of Severity of Acute Pancreatitis

Severe acute pancreatitis (SAP) concerns 10–20% of acute pancreatitis (AP) patients and is associated with a poor prognosis and high mortality. An early prognosis of the unfavorable outcome, transfer to an intensive care unit (ICU) and the introduction of an adequate treatment are crucial for patients’ survival. Recently, the elevated circulating urokinase-type plasminogen activator receptor (uPAR) has been reported to predict SAP with a high diagnostic accuracy among patients in a tertiary center. The aim of the study was to compare the diagnostic utility of uPAR and other inflammatory markers as the predictors of the unfavorable course of AP in patients admitted to a secondary care hospital within the first 24 h of the onset of AP. The study included 95 patients, eight with a SAP diagnosis. Serum uPAR was measured on admission and in the two subsequent days. On admission, uPAR significantly predicted organ failure, acute cardiovascular failure, acute kidney injury, the need for intensive care, and death. The diagnostic accuracy of the admission uPAR for the prediction of SAP, organ failure, and ICU transfer or death was low to moderate and did not differ significantly from the diagnostic accuracy of interleukin-6, C-reactive protein, procalcitonin, D-dimer and soluble fms-like tyrosine kinase-1. In the secondary care hospital, where most patients with AP are initially admitted, uPAR measurements did not prove better than the currently used markers.

Hemostatic gene polymorphisms in severe acute pancreatitis

OBJECTIVE

Systemic inflammatory reaction in acute pancreatitis (AP) is associated with activation of the coagulation system. The prothrombotic component of the coagulation system, which may promote microvascular thrombosis and vital organ injury, is strengthened by genetic factors such as polymorphism of plasminogen activator inhibitor type 1 (PAI-1) and factor V Leiden (FVL) mutation. This prompted us to study the occurrence of FVL and PAI-1 4G/5G polymorphisms in patients with AP.

METHODS

This case control association study included 397 patients with AP and 310 controls. Severe AP was determined according to the Atlanta Classification. Genotyping was performed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry-assisted genotyping method.

RESULTS

Factor V Leiden was identified in 5 (3.3%) of 152 cases of severe AP and in 8 (3.3%) of 245 cases of mild AP. The prothrombotic PAI-1 4G allele frequency was 0.49 for patients with severe AP and 0.57 for patients with mild AP (P < 0.05). Patients with septic infectious complications (n = 47) and patients with organ failure (n = 55) had genotype distribution not different from those with mild, uncomplicated disease (n = 245).

CONCLUSIONS

The results do not support the hypothesis that prothrombotic polymorphisms such as FVL mutation and PAI-1 4G/5G are associated with AP severity.

Comparison of pancreas juice proteins from cancer versus pancreatitis using quantitative proteomic analysis

OBJECTIVES

Pancreatitis is an inflammatory condition of the pancreas. However, it often shares many molecular features with pancreatic cancer. Biomarkers present in pancreatic cancer frequently occur in the setting of pancreatitis. The efforts to develop diagnostic biomarkers for pancreatic cancer have thus been complicated by the false-positive involvement of pancreatitis.

METHODS

In an attempt to develop protein biomarkers for pancreatic cancer, we previously use quantitative proteomics to identify and quantify the proteins from pancreatic cancer juice. Pancreatic juice is a rich source of proteins that are shed by the pancreatic ductal cells. In this study, we used a similar approach to identify and quantify proteins from pancreatitis juice.

RESULTS

In total, 72 proteins were identified and quantified in the comparison of pancreatic juice from pancreatitis patients versus pooled normal control juice. Nineteen of the juice proteins were overexpressed, and 8 were underexpressed in pancreatitis juice by at least 2-fold compared with normal pancreatic juice. Of these 27 differentially expressed proteins in pancreatitis, 9 proteins were also differentially expressed in the pancreatic juice from pancreatic cancer patient.

CONCLUSIONS

Identification of these differentially expressed proteins from pancreatitis juice provides useful information for future study of specific pancreatitis-associated proteins and to eliminate potential false-positive biomarkers for pancreatic cancer.

Pancreas recovery following cerulein-induced pancreatitis is impaired in plasminogen-deficient mice

BACKGROUND & AIMS

The plasminogen (plg) system participates in tissue repair in several organs, but its role in pancreas repair remains poorly characterized. To understand better the role of plg in pancreas recovery following injury, we examined the course of cerulein-induced pancreatitis in plg-deficient and -sufficient mice.

METHODS

Pancreatitis was induced by cerulein administration (50 microg/kg, 7 intraperitoneal injections). Mice were killed either at the acute phase (7 hours after the first cerulein injection) or during recovery (at 2, 4, and 7 days). In pancreatic sections, we examined pancreatic morphology, trypsin activation, inflammatory cell infiltration, acinar cell death, cell proliferation, extracellular matrix deposition, activation of stellate cells (PSCs), and components of the plg and metalloproteinase systems.

RESULTS

In plg-sufficient mice, pancreatic plg levels and plasmin activity increased during the acute phase and remained elevated during recovery. Pancreatitis resolved in plg-sufficient mice within 7 days. Pancreas recovery involved reorganization of the parenchyma structure, removal of necrotic debris, cell proliferation, transient activation of PSCs, and moderate deposition of extracellular matrix proteins. Acute pancreatitis (7 hours) was indistinguishable between plg-deficient and -sufficient mice. In contrast, pancreas recovery was impaired in plg-deficient mice. Plg deficiency led to disorganized parenchyma, extensive acinar cell loss, poor removal of necrotic debris, reduced cell proliferation, and fibrosis. Fibrosis was characterized by deposition of collagens and fibronectin, persistent activation of PSCs, and up-regulation of pancreatic transforming growth factor beta1.

CONCLUSIONS

Plg/plasmin deficiency leads to features similar to those found in chronic pancreatitis such as parenchymal atrophy and fibrosis.

Pancreatic gene expression during the initiation of acute pancreatitis: identification of EGR-1 as a key regulator

We hypothesized that genes expressed in pancreatic acinar cells during the initiation of acute pancreatitis determine the severity of the disease. Therefore, we utilized microarrays to identify those genes commonly induced in rat pancreatic acinar cells within 1-4 h in two in vivo models, caerulein and taurocholate administration. This strategy yielded 51 known genes representing a complex array of molecules, including those that are likely to either reduce or increase the severity of the disease. Novel genes identified in the current study included ATF3, BRF1, C/EBPbeta, CGRP, EGR-1, ephrinA1, villin2, ferredoxin, latexin, lipocalin, MKP-1, NGFI-B, RhoA, tissue factor (TF), and syndecan. To validate these microarray results, the role of EGR-1 was further investigated using quantitative RT-PCR, Western blotting, and immunocytochemistry. EGR-1 expression occurred within acinar cells and correlated with the development of caerulein-induced acute pancreatitis in rats. Furthermore, the levels of the inflammation-related genes MCP-1, PAI, TF, IL-6, and ICAM-1 and the extent of lung inflammation were reduced during the initiation of caerulein-induced acute pancreatitis in EGR-1-deficient mice. Thus this study identified EGR-1 and several other novel genes likely to be important in the development and severity of acute pancreatitis.

A Forkhead/winged helix-related transcription factor mediates insulin-increased plasminogen activator inhibitor-1 gene transcription

Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of fibrinolysis by its inhibition of both tissue-type and urokinase plasminogen activators. PAI-1 levels are elevated in type II diabetes and this elevation correlates with macro- and microvascular complications of diabetes. Insulin increases PAI-1 production in several experimental systems, but the mechanism of insulin-activated PAI-1 transcription remains to be determined. Deletion analysis of the PAI-1 promoter revealed that the insulin response element is between -117 and -7. Mutation of the AT-rich site at -52/-45 abolished the insulin responsiveness of the PAI-1 promoter. This sequence is similar to the inhibitory sequence found in the phosphoenolpyruvate carboxylkinase/insulin-like growth factor-I-binding protein I promoters. Gel-mobility shift assays demonstrated that the forkhead bound to the PAI-1 promoter insulin response element. Expression of the DNA-binding domain of FKHR acted as a dominant negative to block insulin-increased PAI-1-CAT expression. A LexA-FKHR construct was also insulin responsive. These data suggested that a member of the Forkhead/winged helix family of transcription factors mediated the effect of insulin on PAI-1 transcription. Inhibition of phosphatidylinositol 3-kinase reduced the effect of insulin on PAI-1 gene expression, a result consistent with activation through FKHR. However, it was likely that a different member of the FKHR family (not FKHR) mediated this effect since FKHR was present in both insulin-responsive and non-responsive cell lines.

Connective tissue growth factor is involved in pancreatic repair and tissue remodeling in human and rat acute necrotizing pancreatitis

OBJECTIVE

To analyze the involvement of connective tissue growth factor (CTGF) in the transforming growth factor-beta (TGF-beta) pathway during acute necrotizing pancreatitis (ANP) in humans and rats.

SUMMARY BACKGROUND DATA

Connective tissue growth factor is involved in several fibrotic diseases and has a critical role in fibrogenesis and tissue remodeling after injury.

METHODS

Normal human pancreas tissue samples were obtained through an organ donor program from five individuals without a history of pancreatic disease. Human ANP tissues were obtained from eight persons undergoing surgery for this disease. In rats, ANP was induced by intraductal infusion of taurocholate. The expression of CTGF was studied by Northern blot analysis, in situ hybridization, and immunohistochemistry in both human and rat pancreatic tissue samples.

RESULTS

Northern blot analysis revealed enhanced CTGF mRNA expression in human ANP tissue samples compared with normal controls. In addition, a concomitant increase in TGF-beta1 was present. By in situ hybridization, CTGF mRNA was localized in the remaining acinar and ductal cells and in fibroblasts. In regions of intense damage adjacent to areas of necrosis, CTGF mRNA signals were most intense. Inflammatory cells were devoid of any CTGF mRNA signals. By immunohistochemistry, CTGF protein was localized at high levels in the same cell types as CTGF mRNA. In ANP in rats, concomitantly enhanced mRNA levels of CTGF, TGF-beta1, and collagen type 1 were present, with a biphasic peak pattern on days 2 to 3 and day 7 after induction of ANP.

CONCLUSIONS

These data indicate that CTGF participates in tissue remodeling in ANP. The expression of CTGF predominantly in the remaining acinar and ductal cells indicates that extracellular matrix synthesis after necrosis is at least partly regulated by the remaining pancreatic parenchyma and only to a minor extent by inflammatory cells. Blockage of CTGF, a downstream mediator of TGF-beta in fibrogenesis, might be useful as a target to influence and reduce fibrogenesis in this disorder.

Role of TGF-beta1, extracellular matrix, and matrix metalloproteinase in the healing process of the pancreas after induction of acute necrotizing pancreatitis using arginine in rats

INTRODUCTION

Pancreatic tissues are almost completely restored to normal after an attack of acute pancreatitis, once the cause of the disease is removed. Transforming growth factor (TGF)-beta and extracellular matrix (ECM) are known to play an important role in the process of wound healing in pathologic diseases. Tissue repair is a process regulated by a balance between synthesis and degradation of ECM.

AIMS

To elucidate the role of TGF-beta, ECM, and matrix metalloproteinase (MMP) in the process of regeneration occurring after acute necrotizing pancreatitis.

METHODOLOGY

Acute necrotizing pancreatitis was induced by intraperitoneal injection of 500 mg/100 g body weight of L-arginine in male Wistar rats. Expression of TGF-beta1 and ECM messenger RNA (mRNA) was determined by Northern blot analysis, and that of MMP-1 and MMP-2 mRNA was examined by the reverse transcription polymerase chain reaction (RT-PCR). Immunoreactivity for ECM components, TGF-beta1, and MMP-2 in the pancreas was assessed by using a monoclonal antibody.

RESULTS

TGF-beta1 mRNA expression reached a peak value on day 2.5, with a decrease on day 3, and reached the control level on day 7. Procollagen types III and IV and fibronectin mRNA reached a peak value on day 2.5, whereas the expression level of procollagen type I mRNA was maximal on day 3, and gradually decreased to control levels by day 7. MMP-2 mRNA was significantly elevated on day 3, and peaked on day 5, whereas MMP-1 mRNA levels did not change throughout the observation period. Immunoreactivity for MMP-2 was observed around disrupted acinar cells and interstitial spaces on day 3, and maximally on day 7. Immunoreactivity for fibronectin was detected around disrupted acinar cells and interstitial spaces. On day 7, it was less than on day 5 around disrupted acinar cells and interstitial spaces, whereas in the regenerated acinar cells, it was undetected.

CONCLUSION

Our results show that TGF-beta1 mRNA expression peaked earlier than that of ECM mRNA. Furthermore, increased level of the MMP-2 transcript was followed by disappearance of fibronectin. Our findings suggest that TGF-beta1 plays an important role in ECM production in the early phase of acute pancreatitis, and that MMP-2 is involved in the subsequent healing process.