Cytokine gene expression in peripheral blood mononuclear cells reflects a systemic immune response in alcoholic chronic pancreatitis

A single-nucleotide polymorphism in tumor necrosis factor-α (-308 G/A) as a biomarker in chronic pancreatitis

OBJECTIVE

Chronic pancreatitis is a gradual, long-term inflammation of the pancreas that results in alteration of its normal structure and function. The study aims to investigate the role of -308 (G/A) polymorphism of TNF-α gene in chronic pancreatitis.

MATERIAL AND METHODS

A total of 200 subjects were included in this case-control study. A total of 100 in patients admitted in the Gastroenterology Unit of Gandhi Hospital and Osmania General Hospital, Hyderabad were included in the present study. An equal number of healthy control subjects were randomly selected for the study. The genotyping of TNF-α gene was carried out by tetra-primer ARMS PCR followed by gel electrophoresis. The TNF-α levels were assayed by enzyme-linked immunosorbent assay.

RESULTS

A significant variation with respect to the genotypic and allelic distribution in the disease group when compared to control subjects [OR=2.001 (1.33-3.005), p<0.0001**] was observed. Subjects homozygous for the A allele had higher TNF-α levels compared to G allele.

CONCLUSION

The present study revealed a significant association of the TNF-α gene promoter polymorphism with chronic pancreatitis. Thus, TNF-α genotype can be considered as one of the biological markers in the etiology of chronic pancreatitis.

The risk of fractures among patients with cirrhosis or chronic pancreatitis

BACKGROUND & AIMS

Cirrhosis and chronic pancreatitis (CP) are accompanied by inflammation and malnutrition. Both conditions can have negative effects on bone metabolism and promote fractures. We evaluated the risk of fractures among patients with CP or cirrhosis and determined the effect of fat malabsorption on fracture risk among patients with CP.

METHODS

We performed a retrospective cohort study using the Danish National Patient Register to identify patients diagnosed with CP or cirrhosis. We analyzed data collected from January 1, 1995, to December 31, 2010, on 20,769 patients (35.5% women with cirrhosis and 11,972 patients (33.5% women) with CP. Each patient was compared with 10 age- and sex-matched controls. We also assessed the risk of fractures among patients with CP who received pancreatic enzyme substitution (PES) for fat malabsorption.

RESULTS

During the study period, bone fractures occurred in 3954 patients with cirrhosis and 2594 patients with CP. The adjusted hazard ratio (HR) for any fracture was 2.4 in patients with cirrhosis (95% confidence interval [CI], 2.2-2.5) and 1.7 in patients with CP (95% CI, 1.6-1.8). The relative risk of low-trauma fractures was highest among individuals younger than 50 years old. Alcohol as an etiology was associated with an increased risk of fracture compared with patients with nonalcoholic cirrhosis (HR, 2.4 vs 1.5; P < .0001) and CP (HR, 2.0 vs 1.5; P < .0001). Patients with CP receiving PES for fat malabsorption had a lower risk of fractures than other CP patients (HR, 0.8; 95% CI, 0.7-0.9). However, increasing the duration of treatment with PES was associated with an increased risk of fracture.

CONCLUSIONS

Patients, especially younger patients, with cirrhosis or CP have an increased risk of fractures of all types.

The role of nitric oxide in the physiology and pathophysiology of the exocrine pancreas

SIGNIFICANCE

Nitric oxide (NO), a ubiquitous gaseous signaling molecule, contributes to both pancreatic physiology and pathophysiology.

RECENT ADVANCES

The present review provides a general overview of NO synthesis, signaling, and function. Further, it specifically discusses NO metabolism and its effects in the exocrine pancreas and focuses on the role of NO in the pathogenesis of acute pancreatitis and pancreatic ischemia/reperfusion injury.

CRITICAL ISSUES

Unfortunately, the role of NO in pancreatic physiology and pathophysiology remains controversial in numerous areas. Many questions regarding the messenger molecule still remain unanswered.

FUTURE DIRECTIONS

Probably the least is known about the downstream targets of NO, which need to be identified, especially at the molecular level.

Mononuclear cells modulate the activity of pancreatic stellate cells which in turn promote fibrosis and inflammation in chronic pancreatitis

Background

Interactions between mononuclear cells and activated pancreatic myofibroblasts (pancreatic stellate cells; PSC) may contribute to inflammation and fibrosis in chronic pancreatitis (CP).

Methods

Markers of fibrosis and inflammation were concomitantly analysed by immunohistochemistry in chronic pancreatitis tissues. In vitro, PSC were stimulated with TNFalpha and LPS. Primary human blood mononuclear cells (PBMC) and PSC were cocultured, followed by analysis of cytokines and extracellular matrix (ECM) proteins. PBMC were derived from healthy donors and CP and septic shock patients.

Results

In areas of mononuclear cell infiltration in chronic pancreatitis tissues, there was decreased immunoreactivity for collagen1 and fibronectin, in contrast to areas with sparse mononuclear cells, although PSC were detectable in both areas. LPS and TNFalpha induced collagen1 and fibronectin levels as well as the matrix degradation enzyme MMP-1. Coculture experiments with PSC and PBMC revealed increased fibronectin secretion induced by PBMC. In addition, donor and CP PBMC significantly induced an increase in IL-6, MCP-1 and TGFbeta levels under coculture conditions. Determination of the source of cytokines and ECM proteins by mRNA expression analysis confirmed PSC as major contributors of ECM production. The increase in cytokine expression was PBMC- and also PSC-derived.

Conclusion

Mononuclear cells modulate the activity of pancreatic stellate cells, which may in turn promote fibrosis and inflammation.

Enhanced expression of interleukin-18 in serum and pancreas of patients with chronic pancreatitis

AIM: To investigate interleukin-18 (IL-18) in patients with chronic panreatitis (CP).

METHODS: We studied 29 patients with CP and 30 healthy controls. Peripheral blood mononuclear cells (PBMC) were isolated and incubated with 50 mmol/L ethanol, lipopolysaccharide (LPS) (doses 25 g/L, 250 g/L, 2500 g/L) and both agents for 24 h. Levels of IL-18 in the supernatants, and levels of IL-18, IL-12, interferon (IFN)-γ and soluble CD14 in the serum were analysed by ELISA technique. Expression of IL-18 in PBMC was investigated by reverse-transcription (RT)-PCR. IL-18 protein levels in CP tissue and in normal pancreas were studied by ELISA technique. IL-18 levels in PBMC and pancreatic tissue were determined by Westernblot. Immunohistochemistry for pancreatic IL-18 expression was performed.

RESULTS: In patients, IL-18 serum levels were significantly enhanced by 76% (mean: 289.9 ± 167.7 ng/L) compared with controls (mean: 165.2 ± 43.6 ng/L; P < 0.0005). IL-12 levels were enhanced by 25% in patients (18.3 ± 7.3 ng/L) compared with controls (14.7 ± 6.8 ng/L, P = 0.0576) although not reaching the statistical significance. IFN-γ and soluble CD14 levels were not increased. In vitro, LPS stimulated significantly and dose-dependently IL-18 secretion from PBMC. Incubation with ethanol reduced LPS-stimulated IL-18 secretion by about 50%. The mRNA expression of IL-18 in PBMC and the response of PBMC to ethanol and LPS was similar in CP patients and controls. In PBMC, no significant differences in IL-18 protein levels were detected between patients and controls. IL-18 protein levels were increased in CP tissues compared to normal pancreatic tissues. IL-18 was expressed by pancreatic acinar cells and by infiltrating inflammatory cells within the pancreas.

CONCLUSION: IL-18 originates from the chronically inflammed pancreas and appears to be involved in the fibrotic destruction of the organ.

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Expression of multidrug resistance proteins in rat and human chronic pancreatitis

BACKGROUND AND AIMS

The expression of the ABC-transporters MDR-1, MRP1, and MRP-2 was investigated in healthy pancreas and in chronic pancreatitis tissue samples in rats and humans to evaluate their possible involvement in a multidrug resistance of the pancreas with consequences for the pharmacologic treatment of pancreatic diseases.

METHODS

Human pancreatic tissue samples of healthy tissue and chronic pancreatitis were collected during pancreas surgery. In rats, the time-course of the expression of transporter proteins was studied 14, 28, and 56 days after experimental induction of chronic pancreatitis. The expression of MDR-1, MRP-1, MRP-2, and furthermore, LRP and PAP was investigated by RT-PCR, Real Time TaqManPCR, and immunohistochemistry.

RESULTS

In rat pancreas, MDR-1 (P-gp) and MRP-1 but in human pancreas MDR-1 (P-gp), MRP-1 and MRP-2 were found to be expressed. Chronic pancreatitis lead to an increased transcription of mRNA of MDR-1 (rat and human) and much lower, MRP-2 (human).

CONCLUSIONS

The expression of P-gp and related transporters could have impact on the metabolism, distribution, and availability of various compounds, including drugs, in the pancreas. The results indicate that this could be more pronounced in chronic pancreatitis.

Analysis of tumor necrosis factor-alpha, transforming growth factor-beta 1, interleukin-10, and interferon-gamma polymorphisms in patients with alcoholic chronic pancreatitis

The pathophysiologic mechanisms underlying alcoholic chronic pancreatitis are poorly understood. Cytokines participate in the immunologic progression of acute and chronic pancreatitis and may play an important role in the development of pancreatic fibrosis. Functional polymorphisms in cytokine genes have been identified that alter cytokine production. The aims of the current investigation were to determine whether functional polymorphisms in the tumor necrosis factor-alpha (TNF-alpha) gene at positions -308 and -238; in the transforming growth factor-beta 1 (TGF-beta(1)) gene at positions -509, +869 (codon 10), and +915 (codon 25); in the interleukin-10 (IL-10) gene at position -1082; and in the intron 1 of the interferon-gamma (IFN-gamma) gene at position +874 are associated with alcoholic chronic pancreatitis. We investigated 42 patients with alcoholic chronic pancreatitis. We studied 94 control subjects for the TNF-alpha polymorphisms and 73 control subjects for the remaining polymorphisms. Mutation analysis was performed by direct DNA sequencing or by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). The genotype frequencies were similar between patients and control subjects for all investigated cytokine polymorphisms (P>.05). We did not find an association between the different genotypes and the clinical course of the disease. Therefore, we assume that these genetic variants do not play a dominant role in alcoholic chronic pancreatitis.

Analysis of tumour necrosis factor alpha and interleukin 10 promotor variants in patients with chronic pancreatitis

OBJECTIVE

Cationic trypsinogen gene mutations are strong risk factors of hereditary pancreatitis. However, 20% of subjects with a trypsinogen mutation never get pancreatitis and the cause of this incomplete penetrance is unknown. We investigated the influence of interleukin 10 (IL10) and tumour necrosis factor alpha (TNFalpha) promotor variants on the manifestation of chronic pancreatitis of different underlying causes and in pancreatic cancer.

METHODS

A total of 335 German patients with chronic pancreatitis were investigated. In 157 patients the disease was related to alcohol abuse; the other cases were of non-alcoholic origin. In the latter group, the serine protease inhibitor, Kazal type 1 (SPINK1) mutation N34S was found in 72 patients and the trypsinogen mutations N29I or R122H were present in 60 patients; in the remaining 46 patients no mutation was found. In addition, we studied 208 patients with pancreatic cancer. As controls, 116 healthy blood donors and 25 healthy carriers of the trypsinogen mutations N29I or R122H were investigated. After DNA extraction from blood leucocytes, genotyping for the cytokine polymorphisms was performed by induced heteroduplex generators and/or direct DNA sequencing of the IL10 and TNFalpha promotor regions.

RESULTS

The frequencies of the promotor polymorphisms of IL10-627A, IL10-1117A, TNF-238A and TNF-308A in patients with alcoholic chronic pancreatitis, idiopathic pancreatitis, SPINK1-N34S-associated chronic pancreatitis and pancreatic cancer did not differ significantly from the control group. The variant TNF-238A was two to four times more frequent in index patients with trypsinogen mutations than in all other groups. The analysis of the allelic frequencies of whole families with trypsinogen mutations revealed that all subjects with the TNF-238A variant suffered from chronic pancreatitis, whereas all intrafamilial controls with wild-type TNF were unaffected.

CONCLUSIONS

TNFalpha and IL10 promotor variants are not associated with a manifestation of chronic pancreatitis or pancreatic cancer. The variant TNF-238A, however, might be a relevant risk factor for disease manifestation in families with hereditary pancreatitis.

Hereditary, familial, and idiopathic chronic pancreatitis are not associated with polymorphisms in the tumor necrosis factor alpha (TNF-alpha) promoter region or the TNF receptor 1 (TNFR1) gene

PURPOSE

Genetic alterations that are associated with acute and chronic pancreatitis remain to be identified.

METHODS

The authors investigated two functionally active tumor necrosis factor (TNF) promoter region polymorphisms at positions -238 and -308 and the entire coding region of the corresponding TNF receptor 1 (TNFR1) gene in 54 patients with hereditary, familial, and idiopathic chronic pancreatitis who were previously tested negative for cationic trypsinogen mutations by direct DNA sequencing.

RESULTS

In three patients, we detected novel DNA variants in the TNFR1 gene that did not segregate with the disease. The genotype frequencies of the TNF promoter polymorphisms were similar between patients and controls.

CONCLUSION

These polymorphisms are not associated with hereditary, familial, or idiopathic chronic pancreatitis.