Increased risk of acute pancreatitis occurrence in smokers with rs5751901 polymorphisms in GGT1 gene

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.

Assessing the causal link between liver function and acute pancreatitis: A Mendelian randomisation study

A correlation has been reported to exist between exposure factors (e.g. liver function) and acute pancreatitis. However, the specific causal relationship remains unclear. This study aimed to infer the causal relationship between liver function and acute pancreatitis using the Mendelian randomisation method. We employed summary data from a genome-wide association study involving individuals of European ancestry from the UK Biobank and FinnGen. Single-nucleotide polymorphisms (SCNPs), closely associated with liver function, served as instrumental variables. We used five regression models for causality assessment: MR-Egger regression, the random-effect inverse variance weighting method (IVW), the weighted median method (WME), the weighted model, and the simple model. We assessed the heterogeneity of the SNPs using Cochran's Q test. Multi-effect analysis was performed using the intercept term of the MR-Egger method and leave-one-out detection. Odds ratios (ORs) were used to evaluate the causal relationship between liver function and acute pancreatitis risk. A total of 641 SNPs were incorporated as instrumental variables. The MR-IVW method indicated a causal effect of gamma-glutamyltransferase (GGT) on acute pancreatitis (OR = 1.180, 95%CI [confidence interval]: 1.021-1.365, P = 0.025), suggesting that GGT may influence the incidence of acute pancreatitis. Conversely, the results for alkaline phosphatase (ALP) (OR = 0.997, 95%CI: 0.992-1.002, P = 0.197) and aspartate aminotransferase (AST) (OR = 0.939, 95%CI: 0.794-1.111, P = 0.464) did not show a causal effect on acute pancreatitis. Additionally, neither the intercept term nor the zero difference in the MR-Egger regression attained statistical significance (P = 0.257), and there were no observable gene effects. This study suggests that GGT levels are a potential risk factor for acute pancreatitis and may increase the associated risk. In contrast, ALP and AST levels did not affect the risk of acute pancreatitis.

The clinical characteristics of focal acute pancreatitis based on imaging diagnosis: comparison with non-localized acute pancreatitis- a preliminary result

BACKGROUND

Focal acute pancreatitis is a special type of acute pancreatitis, which diagnosis is based on image showing a focal mass formation in the pancreas. For acute pancreatitis with or without focal inflammatory enlargement, little is known on differences between them. Our purpose was to find differences between focal acute pancreatitis and non-localized acute pancreatitis.

METHODS

We reviewed the medical records of a total of 24 patients diagnosed with focal acute pancreatitis by imaging and clinical diagnosis, and 27 cases of acute pancreatitis which manifest non-localized pancreas inflammation were selected as the control group. The differences of the two groups were compared to describe their clinical characteristics.

RESULTS

Differences in bloating (4.2% VS 29.6%,P = 0.026), abdominal tenderness (58.3% VS 85.2%,P = 0.032), peripheral blood neutrophil ratio (60.1 ± 23.3VS 75.9 ± 12.6,P = 0.004), serum D-Dimer (0.40(0.25,0.98) VS 1.59(0.49,4.63),P = 0.008), serum GGT (40(25,91) VS120(22,383),P = 0.046), serum amylase(435(241,718) VS 591(394,1333),P = 0.044) and lipase(988(648,1067) VS 1686(525,2675),P = 0.027) between focal acute pancreatitis and non-localized acute pancreatitis groups were statistically significant. However, difference of the severity of two groups was not statistically significant (P = 1.000).

CONCLUSION

Compared with non-localized acute pancreatitis, changes in symptoms, signs and laboratory indicators of focal acute pancreatitis are non-obvious, however, there was no significant difference in the severity of two groups, indicating that we should pay more attention to diagnosis of focal acute pancreatitis in clinical practice.

Genetic polymorphisms of GGT1 gene (rs8135987, rs5751901 and rs2017869) are associated with neoadjuvant chemotherapy efficacy and toxicities in breast cancer patients

BACKGROUND

Our previous study illustrated the predictive value of serum gamma-glutamyl transpeptidase (GGT) for neoadjuvant chemotherapy (NAC) sensitivity in breast cancer patients. In this study we aim to determine whether single nucleotide polymorphisms (SNPs) in the gamma-glutamyltransferase 1 (GGT1) gene are related to the NAC response and adverse events and to find out a genetic marker in predicting NAC sensitivity.

METHODS

Three SNP loci (rs8135987, rs5751901, rs2017869) of GGT1 gene were selected and tested among breast cancer patients reciving NAC. Four genotype models were used in SNP analysis: co-dominant model compared AA vs. Aa vs. aa; dominant model compared AA vs. Aa + aa; recessive model compared AA + Aa vs. aa; over-dominant model compared AA + aa vs. Aa. Chi-squared test and multivariable logistic regression analysis were performed between SNP genotypes, haplotypes and pathological complete response(pCR), adverse events as well as serum GGT level.

RESULTS

A total of 143 patients were included in the study. For SNP rs8135987 (T > C), the TC genotype in over-dominant model was inversely related with pCR (adjusted OR = 0.30, 95% CI 0.10-0.88, p = 0.029) as well as the risk of peripheral neuropathy (adjusted OR = 0.39, 95% CI 0.15-0.96, p = 0.042). The TC genotype in dominant model was significantly associated with elevated serum GGT level (OR = 3.11, 95% CI 1.07-9.02, p = 0.036). For rs2017869 (G > C), the occurrence of grade 2 or greater neutropenia (OR = 0.39, 95% CI 0.08-0.84, p = 0.025) and leukopenia (OR = 0.24, 95% CI 0.08-0.78, p = 0.017) were both significantly reduced in patients with CC genotypes. For rs5751901(T > C), the CC genotype could significantly reduce the risk of grade 2 or greater neutropenia (OR = 0.29, 95% CI 0.09-0.96, p = 0.036) and leukopenia (OR = 0.27, 95% CI 0.09-0.84, p = 0.024) in recessive model.

CONCLUSIONS

The GGT1 gene SNPs might be an independent risk factor for poor response of NAC in breast cancer patients, providng theoretical basis for further precision therapy.

Genetic determinants of pancreatitis: relevance in severe hypertriglyceridemia

PURPOSE OF REVIEW

Not all patients with severe hypertriglyceridemia develop acute pancreatitis. We surveyed recent literature on inter-individual genetic variation in susceptibility to pancreatitis.

RECENT FINDINGS

Genetic determinants of pancreatitis include: rare Mendelian disorders caused by highly penetrant pathogenic variants in genes involved in trypsinogen activation; uncommon susceptibility variants in genes involved in trypsinogen activation, protein misfolding as well as calcium metabolism and cystic fibrosis, that have variable penetrance and show a range of odds ratios for pancreatitis; and common polymorphisms in many of the same genes that have only a small effect on risk. The role of these genetic variants in modulating pancreatitis risk in hypertriglyceridemia is unclear. However, among genetic determinants of plasma triglycerides, those predisposing to more severe hypertriglyceridemia associated with chylomicronemia appear to have higher pancreatitis risk.

SUMMARY

Currently, among patients with severe hypertriglyceridemia, the most consistent predictor of pancreatitis risk is the triglyceride level. Furthermore, pancreatitis risk appears to be modulated by a higher genetic burden of factors associated with greater magnitude of triglyceride elevation. The role of common and rare genetic determinants of pancreatitis itself in this metabolic context is unclear.

Importance of Polymorphisms in the Gene of Paraoxonase-1 (SNP rs662) and Apolipoprotein A-I (SNP rs670 and rs5069) in Non-Smoking and Smoking Healthy Subjects and Patients with Acute Pancreatitis

Oxidative stress has been implicated in the initiation of acute pancreatitis (AP). HDL is considered to be a preventing factor against cell membrane oxidation, thanks to the presence on its surface of apolipoprotein A-I (apoA-I) and paraoxonase-1 (PON1), which activity can be modified by genetic and environmental factors. The impact of SNP rs662 in the PON1 gene and SNP rs670 and rs5069 in the APOAI gene on PON1 activities and its concentration in the population of AP patients and healthy volunteers was investigated. In the group of patients with AP, a decreased HDL concentration and PON1 activities were observed. A decrease in the aryloesterase and lactonase activities of PON1 in AP patients with the TT genotype for SNP rs662 (especially in smokers) was found. In the group of patients with the AA genotype (rs670), the highest concentrations of HDL and apoA-I were observed, which were gradually decreasing in the course of AP. Changes in the concentration of apoA-I were associated with the changes in the concentration and activities of PON1 in the AP patients with the AA genotype for SNP rs670. A decreasing apoA-I concentration contributing to lowering PON1 concentration and its activities during the hospitalization of AP patients with the CC genotype for SNP rs5069 were shown. Therefore, more susceptibility of persons with the CC genotype for SNP rs5069 to pro/antioxidative imbalance was shown. In this process, an important role was played by the HDL level and its interaction with PON1 and apoA-I.

Characterization of the impact of the MYBBP1A gene and rs3809849 on asparaginase sensitivity and cellular functions

Aims: To investigate the role of MYBBP1A gene and rs3809849 in pancreatic cancer (PANC1) and lymphoblastic leukemia (NALM6) cell lines and their response to asparaginase treatment. Materials & methods: The authors applied CRISPR-Cas9 to produce MYBBP1A knock-out (KO) and rs3809849 knock-in (KI) cell lines. The authors also interrogated rs3809849's impact on PANC1 cells through allele-specific overexpression. Results: PANC1 MYBBP1A KO cells exhibited lower proliferation capacity (p ≤ 0.05), higher asparaginase sensitivity (p = 0.01), reduced colony-forming potential (p = 0.001), cell cycle blockage in S phase, induction of apoptosis and remarkable morphology changes suggestive of an epithelial-mesenchymal transition. Overexpression of the wild-type (but not the mutant) allele of MYBBP1A-rs3809849 in PANC1 cells increased asparaginase sensitivity. NALM6 MYBBP1A KO displayed resistance to asparaginase (p < 0.0001), whereas no effect for rs3809849 KI was noted. Conclusions:MYBBP1A is important for regulating various cellular functions, and it plays, along with its rs3809849 polymorphism, a tissue-specific role in asparaginase treatment response.

Association of genetic variants in the GPX1 and GPX4 genes with the activities of glutathione-dependent enzymes, their interaction with smoking and the risk of acute pancreatitis

Genetic factors and tobacco smoke exposure can be associated with an increased risk of acute pancreatitis (AP). The pathogenesis of AP is associated with intensive oxidative stress. Glutathione peroxidase (GPx) is one of many enzymes involved in the neutralization of free radicals. This study aimed to investigate the impact of SNP rs1050450 in the GPX1 gene and rs713041 in the GPX4 gene on the activity of total GPx in a group of AP patients and healthy subjects. It was found that AP can contribute to decreased GPx activity (in plasma and erythrocyte lysate) accompanied by an increased glutathione reductase (GR) activity and decreased glutathione (GSH) concentration in two groups, non-smokers and smokers. A decreased GPx activity in erythrocyte lysate of AP patients compared to healthy subjects was associated with the occurrence of the CC genotype for SNP rs1050450. It was noted an increased GPx activity and decreased GR activity in erythrocytes of non-smoking AP patients with the TT genotype compared to subjects with the CC and TC genotype for SNP rs713041. However, in the group of smoking AP patients with this genotype, GR activity was elevated compared to non-smokers, which was accompanied by increased GSH concentration. These results can indicate that smoking in the course of AP can change the involvement of antioxidants in dependence on the genotype for the examined SNPs. The CC genotype for SNP rs1050450 and the TT genotype for rs713041 increases the risk of AP recurrence, which may be associated with increased MDA concentration.

Activity of glutathione S-transferase and its π isoenzyme in the context of single nucleotide polymorphism in the GSTP1 gene (rs1695) and tobacco smoke exposure in the patients with acute pancreatitis and healthy subjects

Oxidative stress associated with the course of acute pancreatitis (AP) can cause changes in the involvement of antioxidants, which can result in the increased production of free radicals with pro-inflammatory potential. Through its noncatalytic activity, the glutathione S-transferase and its π isoenzyme (GST-π), apart from cellular xenobiotics detoxification, are involved in the regulation of cellular signalling, metabolism and apoptosis. This study aimed to evaluate the impact of SNP rs1695 in the GSTP1 gene on GST and GST-π activity in healthy subjects and patients with acute pancreatitis (AP). The concentration of glutathione (GSH) as an important component of the antioxidant system, necessary for environmental xenobiotics detoxification by GST, and malonyldialdehyde (MDA) as a marker of oxidative stress induced by inflammation were also assessed. SNP was examined in 39 AP patients and 51 healthy subjects using PCR-RFLP methods. GST activity (in plasma and erythrocyte lysate) and GST-π activity (in erythrocyte lysate) were measured using the spectrophotometric method with 1-chloro-2,4-dinitrobenzene and ethacrynic acid as substrate, respectively. Blood GSH concentration was measured using the Patterson method. Concentrations of high-sensitive C-reactive protein (hs-CRP) and MDA were measured using commercial tests. In the blood of non-smoking AP patients with GG genotypes for SNP rs1695 in the GSTP1 gene, the lowest GST-π activity was shown. It was accompanied by the lowest hsCRP concentration in this group. In the blood of smoking healthy subjects with AG genotype, a decrease in GST-π activity was noted compared to non-smokers from this group. However, in the blood of smokers with AP, a gradually decreasing GST-π activity was noted in individuals with AA genotype, which was associated with the increasing MDA concentration. It confirms the role of GST-π in the neutralization of oxidative stress induced by the exposure to smoke xenobiotics.

Complex Genetics in Pancreatitis: Insights Gained From a New Candidate Locus Panel

OBJECTIVES

Chronic pancreatitis is the end stage of a pathologic inflammatory syndrome with multiple etiological factors, including genetic. We hypothesized that some pancreatitis etiology originates in pancreatic acinar or duct cells and requires both injury and compensatory mechanism failure.

METHODS

One hundred pancreatitis patients were assessed using a DNA sequencing panel for pancreatitis. Cooccurrence of variants within and between genes was measured. Gene coexpression was confirmed via published single-cell RNA sequencing.

RESULTS

One hundred and twenty-one variants were identified in 2 or more patients, 15 of which were enriched compared with reference populations. Single cell RNA-sequencing data verified coexpression of GGT1, CFTR, and PRSS1 in duct cells, PRSS1, CPA1, CEL, CTRC, and SPINK1 in acinar cells, and UBR1 in both. Multiple-risk variants with injury/stress effects (CEL, CFTR, CPA1, PRSS1) and impaired cell protection (CTRC, GGT1, SPINK1, UBR1) cooccur within duct cells, acinar cells, or both.

CONCLUSIONS

Pancreatitis is a complex disorder with genetic interactions across genes and cell types. These findings suggest a new, non-Mendelian genetic risk/etiology paradigm where a combination of nonpathogenic genetic risk variants in groups of susceptibility genes and injury/dysfunction response genes contribute to acquired pancreatic disease.