The 4G/4G genotype of the 4G/5G polymorphism of the type-1 plasminogen activator inhibitor (PAI-1) gene is a determinant of penetrating behaviour in patients with Crohn's disease

Association of plasminogen activator inhibitor-1 gene polymorphism with inflammatory bowel disease in Iranian Azeri Turkish patients

BACKGROUND/AIM

Previous studies have shown the association of some genetic factors, such as Plasminogen activator inhibitor type-1 (PAI-1) 4G/5G polymorphism, with the development of inflammatory bowel disease (IBD). We aimed to study this polymorphism as a risk factor in IBD patients in this cohort.

PATIENTS AND METHODS

One hundred and fifteen IBD patients and 95 healthy controls were selected from Iranian Azeri Turks and -6754G/5G polymorphism of PAI-1 gene was tested by polymerase chain reaction using allele-specific primers confirmed by sequencing.

RESULTS

There was no significant difference of PAI-1 polymorphism between IBD patients and the control group (P>0.05). Furthermore, these data showed no significant difference between Crohn's disease and ulcerative colitis patients. However, 4G/4G homozygotes have reduced probability to progression of loss of appetite, whereas 5G/5G genotypes have increased risk for development of chronic diarrhea without blood, nausea, and loss of appetite.

CONCLUSIONS

Although our study showed no significant association of PAI-1 polymorphism between patients and control group, the carriers of 4G/4G genotype and 4G allele had reduced risk for the progression of IBD features in this cohort.

Role of genetics in the diagnosis and prognosis of Crohn's disease

Considering epidemiological, genetic and immunological data, we can conclude that the inflammatory bowel diseases are heterogeneous disorders of multifactorial etiology in which hereditability and environment interact to produce the disease. It is probable that patients have a genetic predisposition for the development of the disease coupled with disturbances in immunoregulation. Several genes have been so far related to the diagnosis of Crohn's disease. Those genes are related to innate pattern recognition receptors, to epithelial barrier homeostasis and maintenance of epithelial barrier integrity, to autophagy and to lymphocyte differentiation. So far, the most strong and replicated associations with Crohn's disease have been done with NOD2, IL23R and ATG16L1 genes. Many genes have so far been implicated in prognosis of Crohn's disease and many attempts have been made to classify genetic profiles in Crohn's disease. CARD15 seems not only a susceptibility gene, but also a disease-modifier gene for Crohn's disease. Enriching our understanding on Crohn's disease genetics is important but when combining genetic data with functional data the outcome could be of major importance to clinicians.

Role of genetics in the diagnosis and prognosis of Crohn's disease

Considering the epidemiological, genetic and immunological data, we can conclude that the inflammatory bowel diseases are heterogeneous disorders of multifactorial etiology in which hereditability and environment interact to produce the disease. It is probable that patients have a genetic predisposition for the development of the disease coupled with disturbances in immunoregulation. Several genes have so far been related to the diagnosis of Crohn's disease. These genes are related to innate pattern recognition receptors, to epithelial barrier homeostasis and maintenance of epithelial barrier integrity, to autophagy and to lymphocyte differentiation. So far, the strongest and most replicated associations with Crohn's disease have been demonstrated with NOD2, IL23R and ATG16L1 genes. Many genes have so far been implicated in the prognosis of Crohn's disease and many attempts have been made for classification of genetic profiles in Crohn's disease. CARD15 seems to be not only a susceptibility gene, but also a disease-modifier gene for Crohn's disease. Enriching our understanding of Crohn's disease genetics is of value, but when combining genetic data with functional data the outcome could be of major importance to clinicians.

Progress of tissue injury in appendicitis involves the serine proteases uPA and PAI-1

OBJECTIVE

Serine proteases and the matrix metalloproteinases (MMPs) are key factors in the proteolytic cascade and participate in extracellular matrix (ECM) degradation. Fibrinolytic activators and inhibitors may have an effect on inflammatory cells, thereby modulating the inflammatory response. It is reasonable to assume that they may be implicated in the tissue injury in acute appendicitis that subsequently leads to appendix perforation. The purpose of this study was to investigate the expression and distribution of urokinase-type plasminogen activator (uPA) and plasminogen-activator inhibitor type 1 (PAI-1) in appendicitis.

MATERIAL AND METHODS

Expression of uPA and expression of PAI-1 were measured in tissue specimens from patients with appendicitis (n=30) and in control specimens (n=9), using the quantitative ELISA technique. Distribution of enzymes was studied with immunohistochemistry. The uPA and PAI-1 levels in the subgroups of appendicitis and controls were compared.

RESULTS

The overall expressions of uPA and PAI-1 were greater in appendicitis than in control specimens (p <0.001 and p<0.0001, respectively). Expressions of uPA and PAI-1 in phlegmonous (n=15), gangrenous (n=6) and perforated appendicitis (n=9) were all higher than those in controls (n=9), (p<0.01). Moreover, the PAI-1 level was elevated in perforated appendicitis compared with phlegmonous appendicitis (p<0.01). uPA staining was observed in connection with vascular endothelial cells and the serosa stained intensely in specimens from perforated appendicitis.

CONCLUSIONS

The expression of uPA and especially the over-expression of PAI-1 seem to correlate to the progression of local inflammatory response in acute appendicitis.

Synergistic effects of the polymorphisms in the PAI-1 and IL-6 genes with smoking in determining their associated risk with coronary artery disease

OBJECTIVES

To assess the relationship between IL-6 and PAI-1 polymorphisms and coronary artery disease (CAD) and to observe the interactions between these polymorphic variants and smoking in the CAD risk.

DESIGN AND METHOD

The study population consisted of 178 patients with angiographically documented CAD and 202 blood donors. The analyses of genetic polymorphisms were performed using the PCR-RFLP method.

RESULTS

The frequency of PAI-1 5G allele was higher in the entire CAD group than in control group (p=0.04, OR=1.35). Also the 5G allele carriers (4G5G+5G5G) were more frequent in patients than in controls (p=0.03, OR=1.93). The number of women carrying 5G allele was again significantly higher among patients (OR=10.95 p=0.0075). The IL-6 C allele frequency was higher only in the CAD male subgroup (p=0.035, OR=1.44). We found synergistic and cumulative effects between specific genotype patterns and smoking in determining the risk of CAD, especially between PAI-1(4G5G+5G5G)+IL-6(CC) and smoking (SIM=4.18 and p=0.0005, OR=9.20, respectively).

CONCLUSIONS

There are synergistic and cumulative effects of 5G allele of PAI-1 polymorphism and C allele of IL-6 polymorphism with smoking in determining their associated risk with CAD.

Genetic risk factors in patients with inflammatory bowel disease and vascular complications: case-control study

BACKGROUND

Inherited risk factors have been suggested to play an important role in the pathogenesis of vascular complications of inflammatory bowel disease (IBD). The aim of the present study was to investigate the role of mutations associated with cardiovascular disease in IBD patients with or without vascular complications compared with thrombotic and healthy controls (HC).

METHODS

Twelve polymorphisms of thrombophilic and vasoactive genes were evaluated in a group of 30 IBD patients with vascular complications (IBD-VC) compared with 60 IBD patients without vascular complications, 30 thrombotic controls (TC), and 54 healthy controls, using a commercially available kit.

RESULTS

No significant differences between IBD-VC and TC concerning the carriage of these mutations were found. The frequencies of the factor V (FV) 506 RQ (Leiden) genotype and the 506Q allele were significantly higher in these groups than in HC (P < 0.05) but not IBD controls (P > 0.05). The allele frequency of the mutant 4G allele of the plasminogen activator inhibitor (PAI) polymorphism, similar in the IBD-VC and TC groups, was significantly higher in these groups compared with the IBD group (P = 0.03) and the HC (P = 0.001). It is noteworthy that there was a trend of association of FV R506Q polymorphism with venous thrombosis and PAI-1 gene polymorphism with arterial thrombosis.

CONCLUSIONS

Our results suggest that the investigated gene polymorphisms do not differ in patients with IBD-VC and TC. FV R506Q and PAI-1 gene polymorphisms might be associated with the increased risk of development of vascular complications in IBD.

A comprehensive analysis of 12 thrombophilic mutations and related parameters in patients with inflammatory bowel disease: data from Turkey

BACKGROUND

Possible association of inflammatory bowel disease (IBD) with the most common inherited prothrombotic conditions has been the focus of many investigations. Advance in modern molecular biology is expanding the thrombophilia evaluation steadily. We tried to put forward a comprehensive thrombophilic profile in IBD and to see the probable role of this profile in pathogenesis.

METHODS

A total of 60 adults (33 patients and 27 healthy controls) were included. We used the CVD-StripAssay which is based on the reverse-hybridization principle to identify a total of 12 thrombophilic gene mutations: Factor V R506Q, Factor V H1299R, prothrombin G20210A, Factor XIII V34L, beta-Fibrinogen-455 G-A, PAI-1 4G/5G, platelet GPIIIa L33P, MTHFR C677T, MTHFR A1298C, ACE I/D, Apo B R3500Q and Apo E2/E3/E4, respectively. Besides, we evaluated many related blood parameters such as protein C, protein S, AT-III, IL-6, TNF-alpha, Apo-A1, Apo-B100, homocysteine (tHcy) etc. using commercially available assays.

RESULTS

The frequencies of genetic polymorphisms were found to be statistically insignificant among patients and controls, except for three: Beta-Fibrinogen-455G-A, MTHFR A1298C and ACE-I/D. Two patients with a history of deep venous thrombosis had more than one polymorphism. Patients with MTHFR C677T and MTHFR A1298C gene mutations had a similar mean tHcy levels with controls. Patients with Apolipoprotein B R3500Q and Apolipoprotein E4 gene mutations had similar mean LDL-cholesterol levels. Mean total cholesterol and triglyceride levels were similar in patients and controls of Apo E2, E3, E4 alleles.

CONCLUSION

Predominantly, the presence of genetic mutations that predispose to hypercoagulable states does not appear to be in correlation with IBD. There was a statistical difference between the proportions of the mutated allele frequencies of Beta-Fibrinogen-455G-A, MTHFR A1298C and ACE-I/D in IBD.

Combined type-1 plasminogen activator inhibitor and NOD2/CARD15 genotyping predicts complicated Crohn's disease behaviour

BACKGROUND

NOD2/CARD15 gene variants have not been universally associated with stricturing behaviour in Crohn's disease. Other behaviour modifying genes could explain these results.

AIM

To study the combined influence of NOD2/CARD15 variants and 4G/4G genotype of type-1 plasminogen activator inhibitor (PAI-1) gene on Crohn's disease behaviour.

METHODS

One hundred and seventy Crohn's disease patients were studied prospectively, with a mean follow-up of 7+/- 6 years. Disease behaviour was registered by using two criteria: the Vienna classification and a non-hierarchical classification based on the behavioural Vienna categories.

RESULTS

In the multivariate analysis for stricturing behaviour according to the Vienna categories, only absence of colonic disease (OR, 4.0; 95% CI: 1.49-11.1; P = 0.006) was an independent predictive factor. However, in the multivariate analysis for stricturing disease applying a non-hierarchical criteria, ileal disease (OR, 4.19; 95% CI: 1.30-13.5; P = 0.01), and carrying both NOD2/CARD15 variants and the 4G/4G PAI-1 genotype (OR, 5.02; 95% CI: 1.44-17.48; P = 0.01) were independent predictive factors. In the multivariate analysis for penetrating behaviour, the 4G/4G PAI-1 (OR, 3.10; 95% CI: 1.54-6.23; P = 0.001) and male sex (OR, 2.44; 95% CI: 1.30-4.60; P = 0.005) were independent predictive factors irrespective of criteria applied.

CONCLUSIONS

Combined PAI-1 and NOD2/CARD15 genotyping predict complicated Crohn's disease. Patients with these variants could benefit from early interventions.

Fibrogenesis in Crohn's disease

INTRODUCTION

Over one-third of patients with Crohn's disease (CD) will develop an intestinal stricture and the great majority of these will require at least one surgical procedure. While the pathogenesis of inflammation in CD has been extensively investigated, knowledge of stricture pathogenesis remains limited. The aim of this review is to discuss the current understanding of fibrogenesis in CD and to outline potential directions in research and therapeutics.

METHODS

The electronic literature (January 1966 to May 2006) on CD-associated fibrosis was reviewed. Further references were obtained by cross-referencing from key articles.

RESULTS

CD-associated fibrosis results from chronic transmural inflammation and a complex interplay among intestinal mesenchymal cells, cytokines, and local inflammatory cells. The fibroblast is the key cell type mediating stricture formation. The cytoarchitecure of the bowel wall is altered with disruption of the muscularis mucosa, thickening of the muscularis propria, and deposition of collagen throughout. The cytokine TGF-beta appears critical in this process, acting to increase growth factor and extracellular matrix (ECM) production and dysregulate ECM turnover. Potential therapeutic interventions are likely to concentrate on modulating down-stream targets of TGF-beta.

CONCLUSIONS

Greater understanding of the biology of fibrostenosis is likely to yield significant advances in our ability to care for patients with stricturing CD. Potential dividends of this approach include identification of novel therapeutic targets and biomarkers useful for prognostication and therapeutic monitoring.

Contemporaneous carrier-state of two or three "proatherosclerotic" variants of APOE, ICAM1, PPARA and PAI-1 genes differentiate CAD patients from healthy individuals

BACKGROUND

Atherosclerosis is the most important cause of coronary artery disease (CAD). Genetic predisposition to CAD is related to polymorphisms of genes encoding products functionally involved in pathogenesis of atherosclerosis. Polymorphisms of genes participating in monocyte adhesion and diapedesis, lipid metabolism and fibrinolysis regulation may be partially responsible for this process. The aim of our study was to assess the polymorphic variants frequencies of ICAM1, APOE, PPARA and PAI-1 genes in CAD patients and healthy blood donors and to find specific arrangement of polymorphic variants which would differentiate both groups.

METHODS

We studied 146 CAD patients and 121 healthy blood donors. Polymorphisms in analyzed genes were examined using PCR-RFLP analysis.

RESULTS

We found significantly higher frequency of 5G allele of PAI-1 gene in patients than in control subjects (p = 0.038, OR = 1.44). We observed also a considerably higher frequency of contemporaneous carriers of two or three "proatherosclerotic" variants: 1) PPARA and PAI-1, 2) APOE and ICAM1 and 3) PPARA, ICAM1 and PAI-1 in CAD group comparing to control subjects. The number of "proatherosclerotic" variants carriers differentiate studied groups also independently of specific genotype arrangement.

CONCLUSION

In conclusion, contemporaneous carrier-state of two or three polymorphic variants within analyzed genes is associated with CAD.

No association is found between the candidate genes of t-PA/plasminogen system and Japanese methamphetamine-related disorder: a collaborative study by the Japanese Genetics Initiative for Drug Abuse

In the central nervous system, tissue-plasminogen activator (t-PA)/plasmin system is involved in long-term synaptic plasticity and remodeling, and participates in rewarding effects of methamphetamine (MAP), by acutely regulating MAP-induced dopamine release in the nucleus accumbens. The aim of this study was to examine the relationships between the patients with MAP abusers/psychosis and the t-PA/plasminogen system genes. Subjects comprised 185 MAP abusers and 288 healthy controls. Four polymorphisms in the t-PA, plasminogen activator inhibitor, and plasminogen genes were examined in the present study. No significant differences were observed in each polymorphism between healthy controls and MAP abusers/psychosis. This study suggests that t-PA/plasminogen system is unlikely to be a major contributor to the substance abuse liability and/or the development of MAP psychosis.

Outcome of patients with nonstenotic, nonfistulizing Crohn's disease

The nonstenotic, nonfistulizing (or inflammatory) pattern of Crohn's disease appears to be unstable in time and may evolve toward either the stenotic or the fistulizing pattern. We aimed to assess the course of the inflammatory disease and its relation to certain clinical characteristics. After a mean follow-up of 93 months, we evaluated 73 patients with an inflammatory pattern. The behavior trend and its relation to disease location, initial treatment, and need for corticosteroids, immunosuppressors, and surgical resection were analyzed. In 64% of the patients the inflammatory pattern did not change, while in 14 and 22% it evolved toward a stenotic and a fistulizing pattern, respectively. This change was mainly determined by the appearance of perianal disease (75%). The mean time to behavior evolution was 67 months. Most patients required corticosteroids (92%). Need for immunosuppressors (48%) and surgical resection (30%) was significantly greater (P < 0.05) among patients with a change in pattern than in those with persistent inflammatory disease. The inflammatory pattern of CD remains stable in about half of patients. The course of this pattern is not indolent, however, since the needs for immunosuppression and surgical resection during follow-up are considerable.

Update in inflammatory bowel disease pathogenesis

PURPOSE OF REVIEW

During the last few years, significant advances have been achieved in the understanding of the pathogenesis of inflammatory bowel disease (IBD). By gaining new insights, paradigms that seemed to be a safe basis of our knowledge on IBD pathogenesis have recently become doubtful. This review discusses and summarizes the most recent developments.

RECENT FINDINGS

Important new insights have been gained into the function of caspase-activating and recruitment domain-15 (CARD15)/NOD2, the first cloned susceptibility gene for Crohn disease (CD). New data on CARD15/NOD2 function and nuclear factor-kappaB activation indicate that an inflammatory reaction of the intestinal mucosa as a response of the innate immune system may be necessary for the maintenance of gut homeostasis. CD may therefore be seen as a defective immune response, no longer only as hyperresponsiveness of the mucosal immune system. Data on CARD15/NOD2 expression suggest that macrophages and epithelial cells could be the site of a primary pathophysiologic defect, and T-cell activation might just be a secondary effect inducing chronification of the inflammation, perhaps as a backup mechanism to a defective innate immunity. In addition to CARD15/NOD2, there are additional "innate" pathways by which commensal and pathogenic bacteria can directly interact with cells of the intestinal mucosa (eg, toll-like receptors). The "germ concept" and the "genetic concept" of IBD pathophysiology are converging.

SUMMARY

New findings are changing our concepts of the pathogenesis of IBD. The innate immune system, early responses to bacterial products, and the modulation of T-cell responses are important aspects that are reviewed.