Chronic pancreatitis associated with an activation peptide mutation that facilitates trypsin activation

Teich, Niels; Ockenga, Johann; Hoffmeister, Albrecht; Manns, Michael P.; Mössner, Joachim; Keim, Volker

doi:10.1053/gast.2000.9312

Cited by 143 publications

(111 citation statements)

References 15 publications

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“…Conceptually, these activation peptide mutations are very important, because they do not affect trypsin structure or function, indicating that pancreatitis-associated mutations exert their effect through altering the properties of the pro-enzyme trypsinogen and not the active enzyme trypsin. In this context, properties of the characterized mutants D19A, D22G and K23R confirmed that increased autoactivation of cationic trypsinogen is a relevant pathomechanism in hereditary pancreatitis [31,32]. To date, only mutation E79K seems to contradict this model, which was shown to decrease autoactivation significantly [33].…”

Section: Model #2 Enhanced Trypsinogen Autoactivation Is a Common Pamentioning

confidence: 58%

“…Because increased autoactivation was observed with the R122H, N29I and N29T mutations, whereas N29I had no effect on trypsin stability, the logical conclusion was put forth that enhanced autoactivation is the common pathogenic mechanism of hereditary pancreatitis associated PRSS1 mutations [16]. This conclusion received very strong support from the analysis of a subset of mutations that alter the activation peptide [31,32]. Conceptually, these activation peptide mutations are very important, because they do not affect trypsin structure or function, indicating that pancreatitis-associated mutations exert their effect through altering the properties of the pro-enzyme trypsinogen and not the active enzyme trypsin.…”

Section: Model #1 Increased Trypsin Stability Causes Hereditary Pancmentioning

confidence: 99%

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Biochemical Models of Hereditary Pancreatitis

Sahin–Tóth

2006

Endocrinology and Metabolism Clinics of North America

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The past decade has witnessed remarkable progress in the genetics of chronic pancreatitis. Mutations of the PRSS1 gene encoding cationic trypsinogen and the SPINK1 gene encoding pancreatic secretory trypsin inhibitor were found in association with hereditary, familial or sporadic chronic pancreatitis; and the genotype -phenotype correlations have been characterized at the clinical level. Despite these accomplishments, our understanding of the molecular mechanism(s) through which PRSS1 and SPINK1 mutations cause chronic pancreatitis has remained sketchy. Pancreatitis-associated gene mutations are believed to result in uncontrolled trypsin activity in the pancreas. Thus, PRSS1 mutations would cause a gain of (trypsin) function, while SPINK1 mutations would result in the loss of a (trypsin inhibitor) function. However, experimental identification of the disease-relevant functional alterations caused by PRSS1 or SPINK1 mutations proved to be challenging, as results of biochemical analyses lent themselves to different interpretations. The present review focuses on PRSS1 mutations and summarizes the salient biochemical findings in the context of the mechanistic models that attempt to explain the connection between mutations and hereditary pancreatitis. Human Trypsinogens and Pancreatitis-Associated Trypsinogen MutationsThe human pancreas produces the digestive pro-enzyme trypsinogen in three isoforms. On the basis of their relative isoelectric points and electrophoretic mobility, these are commonly referred to as cationic trypsinogen, anionic trypsinogen, and mesotrypsinogen. The isoenzymes are encoded by separate genes, the PRSS1 (protease, serine, 1), PRSS2 and PRSS3 genes (for a recent review see [1] and references therein). Cationic trypsinogen (PRSS1) and anionic trypsinogen (PRSS2) make up the bulk of secreted trypsinogens in the pancreatic juice, while mesotrypsinogen (PRSS3) accounts for 2-10 % [2-6]. Typically, there is approximately twice as much cationic trypsinogen as anionic trypsinogen, but this ratio is reversed in chronic alcoholism or chronic pancreatitis [3,5]. The significance of the "isoform reversal" is unknown [7]. Human trypsinogens are synthesized as pre-pro-enzymes with a signal peptide of 15 amino acids, followed by the 8 amino acid long pro-peptide, the trypsinogen activation peptide. The signal-peptide is removed upon entry into the endoplasmic reticulum lumen and the proenzymes are packaged into zymogen granules and eventually secreted into the pancreatic juice. Physiological activation of trypsinogen to trypsin takes place in the duodenum by enteropeptidase (enterokinase), a highly specialized serine protease in the brush-border membrane of enterocytes. Trypsin can also activate trypsinogen, a process termed autoactivation, which in the duodenum may have a physiological role in facilitating zymogen activation, whereas inappropriate autoactivation in the pancreas might cause pancreatitis. Mutations in the PRSS1 gene have been identified in patients with hereditary pancreatitis, fam...

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Section: Model #2 Enhanced Trypsinogen Autoactivation Is a Common Pamentioning

confidence: 58%

Section: Model #1 Increased Trypsin Stability Causes Hereditary Pancmentioning

confidence: 99%

Biochemical Models of Hereditary Pancreatitis

Sahin–Tóth

2006

Endocrinology and Metabolism Clinics of North America

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“…All of these possibilities would require that trypsin is, indeed, the trigger of an activation cascade in the pancreas. Studies that have addressed the functional role of disease-relevant trypsin mutations had to rely, as of today, on in vitro experiments in which the activation kinetics of recombinant mutant trypsin were compared with the wild-type enzyme (22,28).…”

Section: Discussionmentioning

confidence: 99%

Trypsin activity is not involved in premature, intrapancreatic trypsinogen activation

Halangk

Krüger

Ruthenbürger

et al. 2002

American Journal of Physiology-Gastrointestinal and Liver Physi

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Halangk, Walter, Burkhard Krü ger, Manuel Ruthenbü rger, Jö rg Stü rzebecher, Elke Albrecht, Hans Lippert, and Markus M. Lerch. Trypsin activity is not involved in premature, intrapancreatic trypsinogen activation. Am J Physiol Gastrointest Liver Physiol 282: G367-G374, 2002. First published September 21, 2001 10.1152/ajpgi.00315.2001.-A premature and intracellular activation of digestive zymogens is thought to be responsible for the onset of pancreatitis. Because trypsin has a critical role in initiating the activation cascade of digestive enzymes in the gut, it has been assumed that trypsin also initiates intracellular zymogen activation in the pancreas. We have tested this hypothesis in isolated acini and lobules from rat pancreas. Intracellular trypsinogen activation was induced by supramaximal secretagogue stimulation and measured using either specific trypsin substrates or immunoreactivity of the trypsinogen activation peptide (TAP). To prevent a trypsin-induced trypsinogen activation, we used the cell-permeant, highly specific, and reversible inhibitor N␣-(2-naphthylsulfonyl)-3-amidinophenylalanine-carboxymethylpiperazide (S124), and to prevent cathepsin-induced trypsinogen activation, we used the cysteine protease inhibitor E-64d. Incubation of acini or lobules in the presence of S124 completely prevented the generation of trypsin activity in response to supramaximal caerulein but had no effect whatsoever on the generation of TAP. Conversely, when trypsin activity was recovered at the end of the experiment by either washout of S124 from acini or extensive dilution of lobule homogenates, it was up to 400% higher than after caerulein alone and corresponded, in molar terms, to the generation of TAP. Both trypsin activity and TAP release were inhibited in parallel by E-64d. We conclude that caerulein-induced trypsinogen activation in the pancreas is caused by an E-64d-inhibitable mechanism such as cathepsin-induced trypsinogen activation, and neither involves nor requires intracellular trypsin activity. Specific trypsin inhibition, on the other hand, prevents 80% of trypsin inactivation or autodegradation in the pancreas. autoactivation; cathepsin B; acute pancreatitis ACUTE PANCREATITIS HAS LONG been thought to represent an autodigestion of the pancreas by its own digestive proteases (1). Recent evidence suggests that a premature activation of digestive proteases does indeed occur within pancreatic acinar cells (6, 10, 13) and has been closely associated with the proteolytic damage to the organ (3, 23). What have remained controversial are the triggering events that initiate the premature and intrapancreatic activation of these proteolytic enzymes that are physiologically synthetized, stored, and secreted from the pancreas as inactive precursor zymogens.In a series of elegant studies from the first half of the last century, Kunitz and Northrop (11) have firmly established that highly purified trypsin cannot only activate other serine protease precursors, such as chymotrypsinogen, but can also convert itsel...

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“…This theory was given wide support when an apparent 'gain-of-function' mutation, namely R122H, in the cationic trypsinogen gene (PRSS1; MIM #276000), was identified as the cause of hereditary pancreatitis. 2 Subsequently identified and functionally characterised pancreatitis-associated PRSS1 missense mutations including D19A, 3 D22G, 3,4 K23R, 3,4 N29I/T, 5 E79K 6 and R122C 7 were also demonstrated to cause a 'gain' of trypsin. By contrast, 'loss-of-function' PRSS1 mutations 8 as well as a degradation-sensitive anionic trypsinogen (PRSS2; MIM #601564) variant (G191R) 9 appear to protect against the disease.…”

Section: Introductionmentioning

confidence: 99%

Detection of a large genomic deletion in the pancreatic secretory trypsin inhibitor (SPINK1) gene

et al. 2006

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Mutations and polymorphisms in the SPINK1 gene, which encodes trypsin's physiological inhibitor, pancreatic secretory trypsin inhibitor, have been found to be associated with chronic pancreatitis. However, to date, all currently reported SPINK1 variants are either single-nucleotide substitutions or microinsertions/deletions. It is possible that large genomic rearrangements at this locus may underlie certain cases of chronic pancreatitis. However, such events, if indeed they exist, may have been overlooked by conventional PCR-based techniques. Here we attempted to screen all four exons as well as the promoter region of the SPINK1 gene for large genomic deletions by means of quantitative high-performance liquid chromatography analysis. Of the 47 pancreatitis families (not carrying any known PRSS1, SPINK1 and CFTR variants/mutations after screening the coding regions by our previously established denaturing highperformance liquid chromatography methods), one family was suggested to carry a large genomic deletion in the SPINK1 gene. The aberrant chromosomal junction was encapsulated by long-range PCR and the breakpoints were determined by direct sequencing of the rearranged fragment. A 2-bp short direct repeat was present at the deletion breakpoints; this simple deletion (c.1 -320_c.55 þ 961del1336 bp) can thus in principle be explained by replication slippage. Identification of this lesion has not only expanded the SPINK1 mutational spectrum but also served to identify a novel mutational mechanism causing chronic pancreatitis.

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Chronic pancreatitis associated with an activation peptide mutation that facilitates trypsin activation

Cited by 143 publications

References 15 publications

Biochemical Models of Hereditary Pancreatitis

Biochemical Models of Hereditary Pancreatitis

Trypsin activity is not involved in premature, intrapancreatic trypsinogen activation

Detection of a large genomic deletion in the pancreatic secretory trypsin inhibitor (SPINK1) gene

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