CTRC gene polymorphism (p.G60=; c.180 C > T) in acute pancreatitis

Genetic Variability in the CPA1 Gene and Its Impact on Acute Pancreatitis Risk: New Insights from a Large-Scale Study

Acute pancreatitis (AP) is a common and potentially lethal disease. Over the last 10 years, AP has become one of the most important healthcare problems. On a global scale, the incidence has increased by 63% over the last 20 years. AP is usually caused by gallstones and excessive alcohol consumption and genetic factors play an important role in the development of inflammation. Recent studies involving the CPA1 mutations are ambiguous and dependent on the population studied. In this study, the variability of the CPA1 gene in patients with AP was analyzed. Genetic material was isolated from the blood of 301 patients with AP and 184 healthy individuals. Identification of the variants in exons 5, 6, 8, and 9 with introns was performed using molecular biology methods. Mutations were identified by comparison to the reference sequence (NM_001868.4). Statistical analysis included the identification of mutations correlating with the risk of AP, the etiology of inflammation, and family history. Several novel mutations in the CPA1 gene have been identified, along with a high degree of variability within the coding region of the carboxypeptidase gene. A correlation between mutations CPA1:c.1072 + 84del; c.987 + 57G>A and increased risk of developing AP was found. Two protective mutations, CPA1:c.625A>T, c.1072 + 94del, were identified. The CPA1 gene is characterized by high sequence variability and regions in which mutations lead to an increased risk of developing AP. Single or co-occurring mutations of the CPA1 gene can significantly affect the risk of developing AP.

Heterozygous Spink1 c.194+2T>C mutation promotes chronic pancreatitis after acute attack in mice

BACKGROUND & AIMS

Mutations in genes, including serine protease inhibitor Kazal-type 1 (SPINK1), influence disease progression following sentinel acute pancreatitis event (SAPE) attacks. SPINK1 c.194+2T > C intron mutation is one of the main mutants of SPINK1，which leads to the impairment of SPINK1 function by causing skipping of exon 3. Research on the pathogenesis of SAPE attacks would contribute to the understanding of the outcomes of acute pancreatitis. Therefore, the aim of the study was to clarify the role of SPINK1 c.194+2T > C mutation in the CP progression after an AP attack.

METHODS

SAPE attacks were induced in wildtype and SPINK mutant (Spink1 c.194+2T > C) mice by cerulein injection. The mice were sacrificed at 24 h, 14 d, 28 d, and 42 d post-SAPE. Data-independent acquisition (DIA) proteomic analysis was performed for the identification of differentially expressed protein in the pancreatic tissues. Functional analyses were performed using THP-1 and HPSCs.

RESULTS

Following SAPE attack, the Spink1 c.194+2T > C mutant mice exhibited a more severe acute pancreatitis phenotype within 24 h. In the chronic phase, the chronic pancreatitis phenotype was more severe in the Spink1 c.194+2T > C mutant mice after SAPE. Proteomic analysis revealed elevated IL-33 level in Spink1 c.194+2T > C mutant mice. Further in vitro analyses revealed that IL-33 induced M2 polarization of macrophages and activation of pancreatic stellate cells.

CONCLUSION

Spink1 c.194+2T > C mutation plays an important role in the prognosis of patients following SAPE. Heterozygous Spink1 c.194+2T > C mutation promotes the development of chronic pancreatitis after an acute attack in mice through elevated IL-33 level and the induction of M2 polarization in coordination with pancreatic stellate cell activation.

GGT1 is a SNP eQTL gene involved in STAT3 activation and associated with the development of Post-ERCP pancreatitis

Post-ERCP pancreatitis (PEP) is an acute pancreatitis caused by endoscopic-retrograde-cholangiopancreatography (ERCP). About 10% of patients develop PEP after ERCP. Here we show that gamma-glutamyltransferase 1 (GGT1)-SNP rs5751901 is an eQTL in pancreatic cells associated with PEP and a positive regulator of the IL-6 amplifier. More PEP patients had the GGT1 SNP rs5751901 risk allele (C) than that of non-PEP patients at Hokkaido University Hospital. Additionally, GGT1 expression and IL-6 amplifier activation were increased in PEP pancreas samples with the risk allele. A mechanistic analysis showed that IL-6-mediated STAT3 nuclear translocation and STAT3 phosphorylation were suppressed in GGT1-deficient cells. Furthermore, GGT1 directly associated with gp130, the signal-transducer of IL-6. Importantly, GGT1-deficiency suppressed inflammation development in a STAT3/NF-κB-dependent disease model. Thus, the risk allele of GGT1-SNP rs5751901 is involved in the pathogenesis of PEP via IL-6 amplifier activation. Therefore, the GGT1-STAT3 axis in pancreas may be a prognosis marker and therapeutic target for PEP.

Clinical interpretation of SPINK1 and CTRC variants in pancreatitis

Since the description of the SPINK1 gene encoding the serine protease inhibitor Kazal type 1 and the CTRC gene encoding the Chymotrypsin C as being involved in chronic pancreatitis, more than 56 SPINK1 and 87 CTRC variants have been reported. Assessing the clinical relevance of SPINK1 and CTRC variants is often complicated in the absence of functional evidence and interpretation of rare variants is not very easy in clinical practice. The aim of this study was to review the different variants identified in these two genes and to classify them according to their degree of damaging effect. This classification was based on the results of in vitro experiments, in silico analysis using different prediction tools, and on population data, in comparing the allelic frequency of each variant in patients with pancreatitis and in unaffected control individuals. This review should help geneticists and clinicians in charge of patient's care and genetic counseling to interpret the results of genetic studies.

Association between genetic variants in CYP2E1 and CTRC genes and susceptibility to alcoholic pancreatitis: A systematic review and meta-analysis

BACKGROUND

Genetic predisposition plays an important role in the development of alcoholic pancreatitis (AP), with previous studies suggesting that genetics variants in certain genes, such asCYP2E1 and CTRC, partially explain individual susceptibility to this disease. Therefore, the aim of this work was to conduct a systematic review and meta-analysis of existing studies that analyzed how polymorphisms within CYP2E1 and CTRC genes influence the risk of AP.

MATERIAL AND METHODS

We performed a systematic review of studies that analyzed the genotype distribution of CYP2E1 and CTRC allelic variants among patients with AP and a group of controls. A meta-analysis was conducted using a random effects model. Odds ratios (ORs) and their confidence intervals (CIs) were calculated.

RESULTS

The T allele of theCTRC 180 C > T variant was significantly more prevalent among patients with AP compared to all controls (OR = 1.79, 95% CI = 1.43-2.24; P < 0.00001) and healthy subjects (OR = 1.84, 95% CI = 1.46-2.31; P < 0.00001). The Trp variant of CTRC Arg254Trp polymorphism was also more prevalent in patients with AP; however, these results were not significant after excluding one study. We found no clear evidence that CYP2E1-DraI or of CYP2E1-RsaI/PstI polymorphisms modulate the risk of developing AP.

CONCLUSIONS

Our meta-analysis supports that the T allele ofCTRC 180C > T polymorphisms modulates the risk of alcoholic pancreatitis. No clear evidence was found for the remaining SNPs being associated with this disease.

CaMKII/proteasome/cytosolic calcium/cathepsin B axis was present in tryspin activation induced by nicardipine

Premature trypsinogen activation is the early event of acute pancreatitis. Therefore, the studies on the processes of trypsinogen activation induced by compounds are important to understand mechanism underly acute pancreatitis under various conditions. Calcium overload in the early stage of acute pancreatitis was previously found to cause intracellular trypsinogen activation; however, treatment of acute pancreatitis using calcium channel blockers did not produced consistent results. Proteasome activity that could be inhibited by some calcium channel blocker has recently been reported to affect the development of acute pancreatitis; however, the associated mechanism were not fully understood. Here, the roles of nicardipine were investigated in trypsinogen activation in pancreatic acinar cells. The results showed that nicardipine could increase cathepsin B activity that caused trypsinogen activation, but higher concentration of nicardipine or prolonged treatment had an opposite effect. The effects of short time treatment of nicardipine at low concentration were studied here. Proteasome inhibition was observed under nicardipine treatment that contributed to the up-regulation in cytosolic calcium. Increased cytosolic calcium from ER induced by nicardipine resulted in the release and activation of cathepsin B. Meanwhile, calcium chelator inhibited cathepsin B as well as trypsinogen activation. Consistently, proteasome activator protected acinar cells from injury induced by nicardipine. Moreover, proteasome inhibition caused by nicardipine depended on CaMKII. In conclusion, CaMKII down-regulation/proteasome inhibition/cytosolic calcium up-regulation/cathepsin B activation/trypsinogen activation axis was present in pancreatic acinar cells injury under nicardipine treatment.

Effects of PRSS1-PRSS2 rs10273639, CLDN2 rs7057398 and MORC4 rs12688220 polymorphisms on individual susceptibility to pancreatitis: A meta-analysis

BACKGROUND

Genetic association studies regarding relationship between PRSS1-PRSS2 rs10273639/CLDN2 rs7057398/MORC4 rs12688220 polymorphisms and pancreatitis yielded conflicting results. We performed this meta-analysis to explore associations between these polymorphisms and pancreatitis in a larger pooled population.

METHODS

A systematic search of the literature was conducted for eligible studies. We used Review Manager to conduct statistical analyses.

RESULTS

Fifteen studies were included in this meta-analysis. The results of pooled analyses showed that CLDN2 rs7057398, MORC4 rs12688220 and PRSS1-PRSS2 rs10273639 polymorphisms were all significantly associated with susceptibility to acute pancreatitis in Caucasians. Moreover, MORC4 rs12688220 and PRSS1-PRSS2 rs10273639 polymorphisms were also significantly associated with susceptibility to chronic pancreatitis in Asians.

CONCLUSIONS

Our findings suggested that rs7057398, rs12688220 and rs10273639 polymorphisms could be used to identify individuals at an elevated susceptibility to acute pancreatitis in Caucasians. Moreover, rs12688220 and rs10273639 polymorphisms could be used to identify individuals at an elevated susceptibility chronic pancreatitis in Asians.

Early Intra-Acinar Events in Pathogenesis of Pancreatitis

Premature activation of digestive enzymes in the pancreas has been linked to development of pancreatitis for more than a century. Recent development of novel models to study the role of pathologic enzyme activation has led to advances in our understanding of the mechanisms of pancreatic injury. Colocalization of zymogen and lysosomal fraction occurs early after pancreatitis-causing stimulus. Cathepsin B activates trypsinogen in these colocalized organelles. Active trypsin increases permeability of these organelles resulting in leakage of cathepsin B into the cytosol leading to acinar cell death. Although trypsin-mediated cell death leads to pancreatic injury in early stages of pancreatitis, multiple parallel mechanisms, including activation of inflammatory cascades, endoplasmic reticulum stress, autophagy, and mitochondrial dysfunction in the acinar cells are now recognized to be important in driving the profound systemic inflammatory response and extensive pancreatic injury seen in acute pancreatitis. Chymotrypsin, another acinar protease, has recently been shown be play critical role in clearance of pathologically activated trypsin protecting against pancreatic injury. Mutations in trypsin and other genes thought to be associated with pathologic enzyme activation (such as serine protease inhibitor 1) have been found in familial forms of pancreatitis. Sustained intra-acinar activation of nuclear factor κB pathway seems to be key pathogenic mechanism in chronic pancreatitis. Better understanding of these mechanisms will hopefully allow us to improve treatment strategies in acute and chronic pancreatitis.

Common variants in the CLDN2-MORC4 and PRSS1-PRSS2 loci confer susceptibility to acute pancreatitis

BACKGROUND/OBJECTIVES

Acute pancreatitis (AP) is one of the most common gastrointestinal disorders often requiring hospitalization. Frequent aetiologies are gallstones and alcohol abuse. In contrast to chronic pancreatitis (CP) few robust genetic associations have been described. Here we analysed whether common variants in the CLDN2-MORC4 and the PRSS1-PRSS2 locus that increase recurrent AP and CP risk associate with AP.

METHODS

We screened 1462 AP patients and 3999 controls with melting curve analysis for SNPs rs10273639 (PRSS1-PRSS2), rs7057398 (RIPPLY), and rs12688220 (MORC4). Calculations were performed for the overall group, aetiology, and gender sub-groups. To examine genotype-phenotype relationships we performed several meta-analyses.

RESULTS

Meta-analyses of all AP patients depicted significant (p-value < 0.05) associations for rs10273639 (odds ratio (OR) 0.88, 95% confidence interval (CI) 0.81-0.97, p-value 0.01), rs7057398 (OR 1.27, 95% CI 1.07-1.5, p-value 0.005), and rs12688220 (OR 1.32, 95% CI 1.12-1.56, p-value 0.001). For the different aetiology groups a significant association was shown for rs10273639 (OR 0.76, 95% CI 0.63-0.92, p-value 0.005), rs7057398 (OR 1.43, 95% CI 1.07-1.92, p-value 0.02), and rs12688220 (OR 1.44, 95% CI 1.07-1.93, p-value 0.02) in the alcoholic sub-group only.

CONCLUSIONS

The association of CP risk variants with different AP aetiologies, which is strongest in the alcoholic AP group, might implicate common pathomechanisms most likely between alcoholic AP and CP.

Genetic Polymorphisms: A Novel Perspective on Acute Pancreatitis

Acute pancreatitis (AP) is a complex disease that results in significant morbidity and mortality. For many decades, it has compelled researchers to explore the exact pathogenesis and the understanding of the pathogenesis of AP has progressed dramatically. Currently, premature trypsinogen activation and NF-κB activation for inflammation are two remarkable hypotheses for the mechanism of AP. Meanwhile, understanding of the influence of genetic polymorphisms has resulted in tremendous development in the understanding of the advancement of complex diseases. Now, genetic polymorphisms of AP have been noted gradually and many researchers devote themselves to this emerging area. In this review, we comprehensively describe genetic polymorphisms combined with the latest hypothesis of pathogenesis associated with AP.

CTRC gene polymorphism may increase pancreatic cancer risk – preliminary study

Pancreatic cancer is often fatal due to delayed diagnosis and treatment difficulties. Objective: To analyze selected SPINK1, CTRC, CFTR, and PRSS1 gene mutations in cancer tissue and blood samples of patients with pancreatic tumors. Materials and method: We enrolled 16 consecutive patients diagnosed with pancreatic tumors. We collected cancer tissue, normal pancreatic tissue, and blood samples for genetic tests. The control group consisted of 419 healthy individuals. Peripheral blood samples were collected from all study participants in EDTA-coated tubes. Results: Out of 16 patients with pancreatic tumors, 12 had pancreatic cancer on microscopic examination (mean age, 60.2 years). The CTRC polymorphism Hetero p.G60=(c.180C>T) was found in 5 patients with pancreatic cancer (41.7% vs. 18.6% in the control group). One patient with pancreatic cancer and a positive family history had the SPINK1 (p.N34S) mutation [8.3% vs. 2.9% (12/419) in the control group]. One patient with pancreatic cancer had the CTRC (p.R254W) mutation [8.3% vs. 1% (4/419) in the control group]. Conclusions: Our preliminary results show that the CTRC polymorphism p.G60= (c.180C>T) is frequent in patients with pancreatic cancer. However, further research is needed to verify our findings.