Increased distribution of collagen type III and reduced expression of matrix metalloproteinase 1 in patients with diverticular disease

Genetic, epigenetic and environmental factors in diverticular disease: systematic review

BACKGROUND

Diverticulosis is a normal anatomical variant of the colon present in more than 70% of the westernized population over the age of 80. Approximately 3% will develop diverticulitis in their lifetime. Many patients present emergently, suffer high morbidity rates and require substantial healthcare resources. Diverticulosis is the most common finding at colonoscopy and has the potential for causing a significant morbidity rate and burden on healthcare. There is a need to better understand the aetiology and pathogenesis of diverticular disease. Research suggests a genetic susceptibility of 40-50% in the formation of diverticular disease. The aim of this review is to present the hypothesized functional effects of the identified gene loci and environmental factors.

METHODS

A systematic literature review was performed using PubMed, MEDLINE and Embase. Medical subject headings terms used were: 'diverticular disease, diverticulosis, diverticulitis, genomics, genetics and epigenetics'. A review of grey literature identified environmental factors.

RESULTS

Of 995 articles identified, 59 articles met the inclusion criteria. Age, obesity and smoking are strongly associated environmental risk factors. Intrinsic factors of the colonic wall are associated with the presence of diverticula. Genetic pathways of interest and environmental risk factors were identified. The COLQ, FAM155A, PHGR1, ARHGAP15, S100A10, and TNFSF15 genes are the strongest candidates for further research.

CONCLUSION

There is increasing evidence to support the role of genomics in the spectrum of diverticular disease. Genomic, epigenetic and omic research with demographic context will help improve the understanding and management of this complex disease.

An experimental study of the vascular embolism caused by recombinant type III collagen implants and hyaluronic acid

BACKGROUND

There are significant differences in the reported incidence of vascular complications that result from the injection of different soft tissue fillers. This study aimed to compare the risk of vascular embolism after recombinant type III collagen implants and hyaluronic acid (HA) injection into arteries.

METHODS

Different concentrations of recombinant type III collagen and Restylane were injected into the central ear artery of rabbits, to construct an immediate embolization model. We screened for vascular recanalization and tissue necrosis at 30 min, 1 day, and 7 days after injection, and histopathology examination was processed on Day 7.

RESULTS

At 30 min after injection, complete recanalization of the central ear artery was observed in 17 rabbits in the C1 group while none in the HA group. On Day 1 after injection, complete recanalization of the CEA main trunk was observed in all rabbits in the collagen group while 50% in the HA group. There was a significant difference between the C1 group and the HA group in terms of vascular recanalization and skin necrosis.

CONCLUSION

Under the present experimental conditions, the risk of causing vascular embolism was much lower with collagen than with Restylane. Different doses of collagen at different injection rates have the same safety profile.

Breast Tissue Reconstruction Using Polycaprolactone Ball Scaffolds in a Partial Mastectomy Pig Model

BACKGROUND

Breast cancer patients suffer from lowered quality of life (QoL) after surgery. Breast conservancy surgery (BCS) such as partial mastectomy is being practiced and studied as an alternative to solve this problem. This study confirmed breast tissue reconstruction in a pig model by fabricating a 3-dimensional (3D) printed Polycaprolactone spherical scaffold (PCL ball) to fit the tissue resected after partial mastectomy.

METHODS

A 3D printed Polycaprolactone spherical scaffold with a structure that can help adipose tissue regeneration was produced using computer-aided design (CAD). A physical property test was conducted for optimization. In order to enhance biocompatibility, collagen coating was applied and a comparative study was conducted for 3 months in a partial mastectomy pig model.

RESULTS

In order to identify adipose tissue and fibroglandular tissue, which mainly constitute breast tissue, the degree of adipose tissue and collagen regeneration was confirmed in a pig model after 3 months. As a result, it was confirmed that a lot of adipose tissue was regenerated in the PCL ball, whereas more collagen was regenerated in the collagen-coated Polycaprolactone spherical scaffold (PCL-COL ball). In addition, as a result of confirming the expression levels of TNF-a and IL-6, it was confirmed that PCL ball showed higher levels than PCL-COL ball.

CONCLUSION

Through this study, we were able to confirm the regeneration of adipose tissue through a 3-dimensional structure in a pig model. Studies were conducted on medium and large-sized animal models for the final purpose of clinical use and reconstruction of human breast tissue, and the possibility was confirmed.

Age-related changes in the ratio of Type I/III collagen and fibril diameter in mouse skin

The content of type I collagen (COL-I) and type III collagen (COL-III) and the ratio between them not only affect the skin elasticity and mechanical strength, but also determine the fibril diameter. In this research, we investigated the age-related changes in COL-I/COL-III ratio with their formed fibril diameter. The experimental result was obtained from high performance liquid chromatography-mass spectrometer, hydroxyproline determination, picrosirius red staining and transmission electron microscopes (TEM), respectively. The result indicated that the COL-I/COL-III ratio in mouse skin increased with aging. From the 0th to 9th week, the COL-I/COLIII ratio increased from 1.3:1 to 4.5:1. From the 9th to the 18th week, it remained between 4.5:1 and 4.9:1. The total content of COL-I and COL-III firstly increased and then decreased with aging. The TEM result showed that the fibril diameter increased with aging. From the 0th to 9th week, the average fibril diameter increased from 40 to 112 nm; From the 9th to 18th weeks, it increased from 112 to 140 nm. After the 9th week. The fibril diameter showed obvious uneven distribution. Thus, the COL-I/COLIII ratio was proportional to the fibril diameter, but inversely proportional to the uniformity of fibril diameter.

Evaluation of molecular and genetic predisposing parameters at diverticular disease of the colon

BACKGROUND

Diverticular disease (DD) refers to the presence of diverticula throughout the gastrointestinal (GI) tract, mainly along colon. DD might evolve into diverticulitis that is accompanied by severe clinical presentation, which includes abscess formation, perforation, stricture, obstruction and/or fistula.

AIM

The aim of the present review is to summarize the role of molecular and genetic factors in DD development, as well as their possible contribution towards new prognostic indicators, diagnostic algorithms and new therapeutic approaches.

METHODS AND RESULTS

Except from common predisposing parameters, several genetic mutations, immune factors, neurotransmitters, hormones and protein dysfunctions have been associated to the early onset of DD symptoms, pathogenesis and prognosis of the disease. Specific structural changes in the colonic wall, altered matrix composition and compromised motility have been verified as possible pathogenic factors for the development of DD. Dysregulation in peristaltic activity and reduced ability of the longitudinal muscle to relax following contraction has been also associated with DD evolution. In addition, it has been suspected that genetic defects combined with alterations in intestinal microbiota might play an important role in diverticulitis presentation.

High-Resolution Colonic Manometry Pressure Profiles Are Similar in Asymptomatic Diverticulosis and Controls

BACKGROUND

Elevated colonic pressures and increased colonic activity have been thought to contribute to the pathophysiology of diverticulosis. However, evidence for this has been limited to low-resolution manometry, which is of limited accuracy.

AIMS

This study aimed to evaluate the contraction pressures, counts, and distance of propagation recorded by high-resolution colonic manometry in diverticulosis vs control patients.

METHODS

High-resolution colonic manometry was used to record descending and sigmoid colon activity pre- and post-meal in patients with established, asymptomatic diverticulosis and in healthy controls. Antegrade and retrograde propagating contractions, distance of propagation (mm), and mean contraction pressures (mmHg) in the descending and sigmoid colon were compared between patients and controls for all isolated propagating contractions, the cyclic motor pattern, and high-amplitude propagating contractions independently.

RESULTS

Mean manometry pressures were not different between controls and diverticulosis patients (p > 0.05 for all comparisons). In the descending colon, diverticulosis patients had lower post-meal mean distance of propagation for all propagating contractions [10.8 (SE1.5) mm vs 20.0 (2.0) mm, p = 0.003] and the cyclic motor pattern [6.0 (2.5) mm vs 17.1 (2.8) mm, p = 0.01]. In the sigmoid colon, diverticulosis patients showed lower post-meal mean distance of propagation for all propagating contractions [10.8 (1.5) mm vs 20.2 (5.9) mm, p = 0.01] and a lower post-meal increase in retrograde propagating contractions (p = 0.04).

CONCLUSIONS

In this first high-resolution colonic manometry study of patients with diverticular disease, we did not find evidence for increased manometric pressures or increased colonic activity in patients with diverticular disease.

Pathophysiology and Epidemiology of Diverticular Disease

Diverticular disease exists on a spectrum, ranging from asymptomatic diverticulosis to complicated diverticulitis. Incidence of diverticulitis in western nations has increased in recent years, although the factors that influence the progression from diverticulosis to diverticulitis are unknown. Geographic/environmental influences, lifestyle variables, and microbiota of the gastrointestinal tract are some of the factors implicated in diverticular disease.

Sex and Race Disparities in Diverticulosis Prevalence

BACKGROUND & AIMS

The prevalence of diverticulosis differs with demographic features of patients, but evidence is limited. Well-defined demographic studies are necessary to understand diverticulosis biology. We estimated the prevalence of diverticulosis among patients of different ages, sexes, and races and ethnicities and calculated odds ratios.

DESIGN

Using data from an endoscopic database, we identified 271,181 colonoscopy procedures performed from 2000 through 2012 at 107 sites in the United States. Our analysis included individuals 40 years and older who underwent colonoscopy examination for average-risk screening. The outcome was any reported diverticulosis on colonoscopy. Multivariate analyses were performed using logistic regression to estimate odds ratios (ORs) and 95% CI values, adjusting for confounding variables.

RESULTS

The prevalence of diverticulosis increased with age in men and women of all races and ethnicities. Women 40-49 years old had significantly lower odds of any diverticulosis (OR, 0.71; 95% CI, 0.63-0.80) compared with men 40-49 years old, after adjustment. The strength of this association decreased with age. Compared with non-Hispanic white individuals, non-Hispanic black individuals (OR, 0.80; 95% CI, 0.77-0.83) and Asian/Pacific Islanders (OR, 0.38; 95% CI, 0.35-0.41) had lower odds of any diverticulosis. However, non-Hispanic black individuals (OR, 1.53, 95% CI, 1.44-1.62) had increased odds of any proximal diverticulosis, whereas Asian/Pacific Islanders (OR, 3.12; 95% CI, 2.67-3.66) had increased odds of only proximal diverticulosis.

CONCLUSIONS

In an analysis of data from 271,181 colonoscopy procedures, diverticulosis was less prevalent in women compared with men in the same age groups, indicating that sex hormones might affect pathogenesis. Differences in the odds of diverticulosis by race and ethnicity indicate a genetic contribution to risk.

Etiopathogenetic Mechanisms in Diverticular Disease of the Colon

This article reviews epidemiological evidence of heritability and putative mechanisms in diverticular disease, with greatest attention to 3 recent studies of genetic associations with diverticular disease based on genome-wide or whole-genome sequencing studies in large patient cohorts. We provide an analysis of the biological plausibility of the significant associations with gene variants reported and highlight the relevance of ANO1, CPI-17 (aka PPP1R14A), COLQ6, COL6A1, CALCB or CALCA, COL6A1, ARHGAP15, and S100A10 to colonic neuromuscular function and tissue properties that may result in altered compliance and predispose to the development of diverticular disease. Such studies also identify candidate genes for future studies.

Diverticulosis and nine connective tissue disorders: epidemiological support for an association

Purpose: An underlying connective tissue disorder (CTD) may predispose to formation of intestinal diverticula. We assess the association of diverticulosis with nine selected CTDs, to inform the pathophysiology of diverticula. Methods: A population-based period-prevalence study. Individuals (3.5 million New Zealand residents born 1901-1986) with a health system record 1999-2016 were grouped into those with a hospital diagnosis of diverticulosis or diverticulitis (ICD-10-AM K57), and those without. Also recorded were any hospital diagnoses of nine selected CTDs. The association of exposure to diverticulosis and each CTD was assessed using logistic regressions adjusted for age, gender, ethnicity and region. Results: In all, 85,958 (2.4%) people had a hospital diagnosis of diverticulosis. Hospitalisation with diverticulosis was highly significantly associated with rectal prolapse (adjusted odds ratio [OR] = 3.9), polycystic kidney disease (OR = 3.8), heritable syndromes (Marfan or Ehlers-Danlos) (OR = 2.4), female genital prolapse (OR = 2.3), non-aortic aneurysm (OR = 2.3), aortic aneurysm (OR = 2.2), inguinal hernia (OR = 1.9) and dislocations of shoulder and other joints (OR = 1.7), but not subarachnoid haemorrhage (OR = 1.0). Conclusion: People with diverticulosis are more likely to have colonic extracellular matrix (ECM)/connective tissue alterations in anatomical areas other than the bowel, suggesting linked ECM/connective tissue pathology. Although biases may exist, the results indicate large-scale integrated studies are needed to investigate underlying genetic pathophysiology of colonic diverticula, together with fundamental biological studies to investigate cellular phenotypes and ECM changes.

Novel swine model of colonic diverticulosis

The pathophysiology of colonic diverticulosis has not been completely understood. The development of appropriate animal models is essential to study diverticular disease. To date, no large animal models are available for this disease condition. The objective of this study was to develop a swine model by damaging the colon wall, combined with or without a low-fiber diet to mimic the pathogenesis of diverticulosis. To create a weakness on the colon wall, collagenase was applied in vivo to degrade the collagen in the colon wall. Three groups of Yucatan minipigs were included. Group 1 (n = 12) underwent collagenase injection (CI) with a low-fiber diet for 6 mo, group 2 (n = 8) underwent CI alone with a standard swine diet for 6 mo, and group 3 (n = 12) received a low-fiber diet alone for 6 mo. We found that diverticulosis occurred in 91.7% (11 of 12) of pigs in the CI + diet group and 100% (8 of 8) in CI-alone group. Moreover, around 30-75% of colon CI spots for each pig developed diverticular lesions. Diet alone for 6 mo did not induce diverticulosis. The endoscopic and histological examinations revealed the formation of multiple wide-mouthed diverticular lesions along the descending colon. Our results provide convincing evidence of the high efficacy of the reduced colon wall strength caused by CI in the development of a swine model of diverticulosis. Low-fiber diet consumption for 6 mo had no influence on the generation time or incidence rate of diverticulosis. In this model, digestion of the collagen in the colonic wall is sufficient to cause diverticulosis. NEW & NOTEWORTHY Effective large animal models of diverticulosis are currently lacking for the study of diverticular disease. This study marks the first time that a swine model of diverticulosis was developed by damaging colon wall structure, combined with or without a low-fiber diet. We found that a defect of colon wall could result in colon diverticular lesions within 6 mo in swine. This animal model mimicking the pathological process of diverticulosis is of great clinical value.

Increasing Diverticulosis in an Aging Population: A Colonoscopy-Based Study of 5-Year Trends in 26 463 Patients in Northern China

Background

Because such data are scarce in northern China, the purpose of this study was to determine trends in diverticulosis over the past 5 years.

Material/Methods

A total of 26 463 patients (27 558 examinations, including 1095 repeated colonoscopies) performed between January 2011 and December 2015 were reviewed respectively. The distributions of diverticulosis were recorded, which were classified as right-sided, left-sided, and bilateral type. The trends in diverticulosis were analyzed in terms of aging and yearly increase. Additionally, associations of the occurrence of diverticulosis with age (≤39, 40–59, and ≥60 years) and sex were determined using a logistic regression model.

Results

We identified 1045 patients with colonic diverticulosis, with an overall prevalence of 3.8% (1045/27 558). A preponderance of right-sided diverticulosis was demonstrated, accounting for 72.9% (693/951) of included subjects. The proportion of colonic diverticulosis increased significantly (P<0.001 for trend), from 2.78% (112/4028) in 2011 to 4.98% (309/6208) in 2015. The proportion of patients of all age groups with diverticulosis increased significantly (P<0.001 for trend) in correlation with yearly increase. There was a greater proportion of diverticulosis, regardless of the distribution, in patients aged ≥60 than in younger age groups (P<0.001 for trend). Multivariate analysis showed older age and male sex (P<0.001) were independent risk factor for diverticulosis.

Conclusions

Colonic diverticulosis has been increasing in northern China, where rapid aging is ongoing.

Structural and functional failure of fibrillin‑1 in human diseases (Review)

Fibrillins (FBNs) are key relay molecules that form the backbone of microfibrils in elastic and non‑elastic tissues. Interacting with other components of the extracellular matrix (ECM), these ubiquitous glycoproteins exert pivotal roles in tissue development, homeostasis and repair. In addition to mechanical support, FBN networks also exhibit regulatory activities on growth factor signalling, ECM formation, cell behaviour and the immune response. Consequently, mutations affecting the structure, assembly and stability of FBN microfibrils have been associated with impaired biomechanical tissue properties, altered cell‑matrix interactions, uncontrolled growth factor or cytokine activation, and the development of fibrillinopathies and associated severe complications in multiple organs. Beyond a panoramic overview of structural cues of the FBN network, the present review will also describe the pathological implications of FBN disorders in the development of inflammatory and fibrotic conditions.

Economic burden of diverticular disease: An observational analysis based on real world data from an Italian region

INTRODUCTION

Diverticular disease (DD), a herniation of the colonic mucosa through the muscle layer, covers a wide variety of conditions associated with the presence of diverticula in the colon. The most serious form is an acute episode of diverticulitis, which can lead to hospitalization and surgery with various types of consequences. The main aim of this study is to evaluate the economic burden of hospitalizations arising from acute episodes of diverticulitis using data from the administrative databases used in the Marche region in Italy and, as a secondary objective of this real-world data analysis, to study patient outcome variables following initial hospitalization for diverticulitis.

METHOD

A deterministic linkage was performed at individual user level between the different administrative sources of the Marche region through anonymous ID number for a period of analysis between 1 January, 2008 and 31 December, 2014. We enrolled all patients with at least one hospitalization for "diverticulitis of the colon without mention of haemorrhage" (ICD-9-CM code 562.11) or "diverticulitis of the colon with haemorrhage" (ICD-9-CM code 562.13) as primary or secondary diagnosis. For each patient we assessed the cost of hospitalization, of medicines and of specialist services considering a time-scale of one year or cohort analysis 365days after first admission.

RESULTS

The total number of residents in the Marche region who had at least one hospitalization for diverticulitis in the period 2008-2014 was 2987 (427 patients a year, corresponding to about 35 patients per 100,000 adult residents); the total number of admissions was 3453 (just over 490 a year). The direct healthcare costs incurred by the Marche region for episodes of diverticulitis in 2008-2014 amounted to approximately €11.4 million (€1.6 million a year), of which €10.9 million (95.5%) for the hospitalizations, € 246,000 (2.1%) for pharmaceutical treatment and €270,000 (2.4%) for specialist outpatient services. The average annual cost per patient was €3826, of which €3653 was for hospitalization, while pharmaceutical expenditure and specialist services accounted for €83 and €90, respectively. The cohort of patients undergoing a first admission for diverticulitis between 2010 and 2013 was made up of 1729 people (54.4% women, mean age 68.9 years), of whom 1500 (86.8%) did not undergo surgery while in hospital. Hospital mortality, recorded only for the over-65 age class, averaged 1.2%; for patients not receiving surgery during the initial hospitalization it was 0.5%, reaching 5.2% in patients undergoing surgery. The percentage of patients with one or more readmissions for diverticulitis within a year of the first was on average 7.8% and in 48% of cases this resulted in surgery.

CONCLUSIONS

Our study is the first analysis in Italy to use real-world data to measure the financial impact of diverticular disease. Assuming that the diagnostic and therapeutic behaviour identified in the Marche region could be representative of the situation nationwide, the estimated annual number of hospitalizations in Italy for acute episodes of diverticulitis is 19,000. The total amount of economic resources needed to treat patients suffering from acute episodes of diverticulitis is estimated at €63.5 million a year.

Diverticular disease is associated with benign intra-abdominal cystic disease

BACKGROUND

Diverticular disease (DD) and hepatic and renal cysts have been linked with defects in collagen and dysfunctional matrix metalloproteinases.

METHODS

Consecutive abdominal computed tomography scans between January-July 2015 were prospectively studied to determine a correlation between visceral cysts and DD. Patients with a sigmoid colectomy for pathology other than DD and scans in which DD and/or solid organs were not fully visualized were excluded. A subgroup analysis was performed on youthful DD patients (<55 years of age, n = 32) vs. older controls (>55, n = 213).

RESULTS

238 DD patients (50.8% male) and 369 controls (40.5% male, p = .02) were included. Incidence of visceral cystic disease in DD patients vs. controls was 71.4% vs. 22.5% (p < 0.00001). Renal cysts, present in 53.4% of the DD patients and 18.7% of the controls (p < .00001), were more common than hepatic cysts in both groups. Hepatic cyst prevalence was 8.8 vs. 2.4% (p = .0008). In the subgroup analysis, cystic disease was present in 56.2% of youthful DD patients vs. 29.1% of older controls (p = .004).

CONCLUSIONS

A significant association between cystic disease and DD was demonstrated overall and in subgroup analysis inclusive of youthful DD patients and older controls. These findings suggest a global defect in connective tissue integrity in DD patients.

Review article: pathogenesis and clinical manifestations of gastrointestinal involvement in systemic sclerosis

BACKGROUND

Gastrointestinal tract (GIT) involvement is a common cause of debilitating symptoms in patients with systemic sclerosis (SSc). There are no disease modifying therapies for this condition and the treatment remains symptomatic, largely owing to the lack of a clear understanding of its pathogenesis.

AIMS

To investigate novel aspects of the pathogenesis of gastrointestinal involvement in SSc. To summarise existing knowledge regarding the cardinal clinical gastrointestinal manifestations of SSc and its pathogenesis, emphasising recent investigations that may be valuable in identifying potentially novel therapeutic targets.

METHODS

Electronic (PubMed/Medline) and manual Google search.

RESULTS

The GIT is the most common internal organ involved in SSc. Any part of the GIT from the mouth to the anus can be affected. There is substantial variability in clinical manifestations and disease course and symptoms are nonspecific and overlapping for a particular anatomical site. Gastrointestinal involvement can occur in the absence of cutaneous disease. Up to 8% of SSc patients develop severe GIT symptoms. This subset of patients display increased mortality with only 15% survival at 9 years. Dysmotiity of the GIT causes the majority of symptoms. Recent investigations have identified a novel mechanism in the pathogenesis of GIT dysmotility mediated by functional anti-muscarinic receptor autoantibodies.

CONCLUSIONS

Despite extensive investigation, the pathogenesis of gastrointestinal involvement in systemic sclerosis remains elusive. Although treatment currently remains symptomatic, an improved understanding of novel pathogenic mechanisms may allow the development of potentially highly effective approaches including intravenous immunoglobulin and microRNA based therapeutic interventions.

Management of sigmoid diverticulitis: an update

The role, indications and modalities of elective resection for sigmoid diverticulitis remain the cause of fierce debate. During the past two decades clinicians have increasingly recognized that: (1) young patients (<50) are no more at risk to develop more aggressive course of the disease; and (2) patients who present initially with a first uncomplicated attack are no more at risk for developing subsequent complicated diverticulitis requiring emergency surgery. Hence, the previously well-recognized indications (based upon age of the patients or the number of attacks) are no longer valid. Yet, the number of sigmoid resections performed for diverticulitis in industrialized countries is increasing, which seems to indicate that in many cases, uncomplicated sigmoid diverticulitis progressively evolves towards a chronic symptomatic condition, which significantly impacts upon the patients' quality of life. The aims of this review are twofold: (1) to identify which disease presentation still represents good indications for elective laparoscopic sigmoid resection; and (2) to summarize the technical aspects of surgery for a benign condition, such as diverticular disease.

Abdominal wall hernias-A local manifestation of systemically impaired quality of the extracellular matrix

BACKGROUND

Throughout life, inguinal hernia develops in approximately every fourth man, some of whom develop multiple hernias. If patients at risk of developing multiple hernias could be identified by a serologic biomarker, treatment might be able to be tailored and improved. Evidence suggests that abdominal wall hernia formation is associated with altered collagen metabolism. The aim of this study was to evaluate biomarkers for type IV and V collagen turnover in patients with multiple hernias and control subjects without hernia.

METHODS

Venous blood was collected from 88 men (mean age, 62 years) with a history of more than 3 hernia repairs and 86, age-matched men without hernias. Biomarkers for synthesis of collagen type IV (P4NP) and type V (P5CP) as well as breakdown (C4M and C5M) were measured in serum by validated, solid-phase, competitive assays. Collagen turnover was indicated by the ratio between the biomarker for synthesis and breakdown.

RESULTS

Type IV collagen turnover was 1.4-fold increased in patients with multiple hernias compared to control subjects (P < .001), whereas type V collagen turnover was 1.7-fold decreased (P < .001). Diagnostic power of P5CP was 0.83 (95%C.I.:0.77-0.89), P < .001.

CONCLUSION

Patients with multiple hernias exhibit increased turnover of type IV collagen and a decreased turnover of type V collagen, demonstrating systemically altered collagen turnover. Biomarkers for type V collagen turnover may be used to identify patients at risk for or with multiple hernias.

Diverticulosis today: unfashionable and still under-researched

Diverticulosis of the colon is a widespread disease, and its prevalence is increasing especially in the developing world. The underlying pathological mechanisms that cause the formation of colonic diverticula remain unclear but are likely to be the result of complex interactions among age, diet, genetic factors, colonic motility, and changes in colonic structure. The large majority of patients remain asymptomatic throughout their life, one fifth of them become symptomatic (developing the so-called 'diverticular disease') while only a minority of these will develop acute diverticulitis. The factors predicting the development of symptoms remain to be identified. Again, it is generally recognized that diverticular disease occurrence is probably related to complex interactions among colonic motility, diet, lifestyle, and genetic features. Changes in intestinal microflora due to low-fiber diet and consequent low-grade inflammation are thought to be one of the mechanisms responsible for symptoms occurrence of both diverticular disease and acute diverticulitis. Current therapeutic approaches with rifaximin and mesalazine to treat the symptoms seem to be promising. Antibiotic treatment is currently advised only in acute complicated diverticulitis, and no treatment has currently proven effective in preventing the recurrence of acute diverticulitis. Further studies are required in order to clarify the reasons why diverticulosis occurs and the factors triggering occurrence of symptoms. Moreover, the reasons why rifaximin and mesalazine work in symptomatic diverticular disease but not in acute diverticulitis are yet to be elucidated.

Management of diverticular disease

Diverticular disease is a common condition in Western countries and the incidence and prevalence of the disease is increasing. The pathogenetic factors involved include structural changes in the gut that increase with age, a diet low in fibre and rich in meat, changes in intestinal motility, the concept of enteric neuropathy and an underlying genetic background. Current treatment strategies are hampered by insufficient options to stratify patients according to individual risk. One of the main reasons is the lack of an all-encompassing classification system of diverticular disease. In response, the German Society for Gastroenterology and Digestive Diseases (DGVS) has proposed a classification system as part of its new guideline for the diagnosis and management of diverticular disease. The classification system includes five main types of disease: asymptomatic diverticulosis, acute uncomplicated and complicated diverticulitis, as well as chronic diverticular disease and diverticular bleeding. Here, we review prevention and treatment strategies stratified by these five main types of disease, from prevention of the first attack of diverticulitis to the management of chronic complications and diverticular bleeding.

Surgical diverticulitis is not associated with defects in the expression of wound healing genes

PURPOSE

The development of diverticuli may represent defects in collagen vascular tissue integrity possibly from a genetic predisposition. We evaluated the tissue expression of wound healing genes in sigmoid tissue from youthful patients undergoing surgery for diverticulitis and thus would more likely suffer from a genetic predisposition (SD mean age 39 ± 0.9) versus controls in the form of patients over the age of 50 (mean age 52.9 ± 10.5 years) without evidence of diverticular disease.

METHODS

The mRNA expression of 84 genes associated with the extracellular matrix, cellular adhesion, growth factors, inflammatory cytokines, and signal transduction was evaluated in 16 SD and 15 control tissues using a Qiagen Wound Healing Array. Vitronectin, the gene protein with the highest potential significance on raw analysis, was further investigated using a Taqman assay with an additional 11 SD (total n = 27) and four control (total n = 19) samples. Statistics were by Student's t and Mann-Whitney tests with Bonferroni correction.

RESULTS

No significant differences in mRNA expression between the SD and control tissue in the 84 measured genes were demonstrated after correction. Vitronectin mRNA expression was downregulated 2.7-fold in SD tissue vs. tissue from non-neoplastic control patients (p = 0.001 raw/0.08 corrected). However, on vitronectin TaqMan analysis, no difference in expression was seen in SD vs. all controls or in all subset comparisons.

CONCLUSIONS

The lack of significant alteration in mRNA expression of traditionally associated wound healing genes/proteins in young SD patients suggests that such genes play a minor role in the genetic predisposition to youthful diverticulitis.

Alterations of the enteric smooth musculature in diverticular disease

BACKGROUND

The pathogenesis of diverticular disease (DD) is considered to be multifactorial and involves intestinal motor disturbances and an underlying enteric neuromuscular pathology. While an enteric neuropathy has been well documented, actual studies on concomitant alterations of the enteric musculature are limited. This study is aimed at reassessing the smooth muscle tissue by histological, ultrastructural and molecular-biological approaches.

METHODS

Full-thickness sigmoid specimens were obtained from patients with DD (n = 20) and controls (n = 19). Morphometric analysis was performed to evaluate the thickness and connective tissue index of the circular and longitudinal muscle layers as well as the myenteric plexus. Structural alterations were determined by light and transmission electron microscopy. mRNA profiles of components of the contractile smooth muscle apparatus including smooth muscle α-actin, smoothelin, histone deacetylase 8, and smooth muscle myosin heavy chain (SMMHC) were assessed by qPCR. Altered gene expression levels were confirmed at protein level by immunohistochemistry.

RESULTS

Compared to controls, patients with DD showed (1) increased thickness of the circular and longitudinal muscle layers, (2) architectural alterations of smooth muscle cells, (3) increased connective tissue index of the longitudinal muscle layer, (4) focally reduced density of myofilaments at ultrastructural level, (5) specific down-regulation of SMMHC mRNA levels, (6) decreased immunoreactivity of SMMHC, (7) oligo-neuronal hypoganglionosis.

CONCLUSIONS

DD is associated with distinct structural and functional alterations of the enteric musculature. The enteric myopathy is characterized by disturbed muscular architecture, connective tissue replacement and loss of specific myofilaments and thus may contribute to the pathogenesis and progression of DD.

Colonic wall changes in patients with diverticular disease - is there a predisposition for a complicated course?

BACKGROUND

The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ).

METHODS

Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ.

RESULTS

Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values.

CONCLUSIONS

This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

The enteric serotonergic system is altered in patients with diverticular disease

OBJECTIVE

Disturbances of the enteric serotonergic system have been implicated in several intestinal motility disorders. Patients with diverticular disease (DD) have been reported to exhibit abnormal intestinal motility and innervation patterns. Gene expression profiles of the serotonergic system and distribution of the serotonin type 4 receptor (5HT-4R) were thus studied in patients with DD.

DESIGN

Colonic specimens from patients with DD and controls were subjected to quantitative PCR for serotonin receptors 2B, 3A, 4, serotonin transporter and synthesising enzyme tryptophan hydroxylase. Localisation of 5HT-4R was determined by dual-label immunocytochemistry using smooth muscle actin (α-SMA) and pan-neuronal markers (PGP 9.5) and quantitative analysis was carried out. Site-specific gene expression analysis of 5HT-4R was assessed within myenteric ganglia and muscle layers. Correlation of 5HT-4R with muscarinic receptors 2 and 3 (M2R, M3R) messenger RNA expression was determined.

RESULTS

5HT-4R mRNA expression was downregulated in the tunica muscularis and upregulated in the mucosa of patients with DD, whereas the other components of the serotonergic system remained unchanged. 5HT-4R was detected in ganglia and muscle layers, but was decreased in the circular muscle layer and myenteric ganglia of patients with DD. 5HT-4R mRNA expression correlated with M2R/M3R mRNA expression in controls, but not in patients with DD.

CONCLUSIONS

The serotonergic system is compromised in DD. Altered expression of 5HT-4R at mRNA and protein levels may contribute to intestinal motor disturbances reported in patients with DD. The findings support the hypothesis that DD is associated and possibly promoted by an enteric neuromuscular pathology.

Heritability and familial aggregation of diverticular disease: a population-based study of twins and siblings

BACKGROUND & AIMS

Little is known about the role of heritable factors in diverticular disease. We evaluated the contribution of heritable factors to the development of diverticular disease diagnosed at a hospitalization or outpatient visit.

METHODS

Using nationwide patient registries, we identified 142,123 incident cases of diverticular disease diagnosed at a hospitalization (1977-2011) or an outpatient hospital visit (1995-2011) in Denmark, including cases in 10,420 index siblings and 923 twins. We calculated standardized incidence ratios for siblings versus the general population and concordance rates for monozygotic versus dizygotic twin pairs as measures of relative risk (RR).

RESULTS

The RR for diverticular disease in siblings of index cases was 2.92 (95% confidence interval [CI], 2.50-3.39) compared with the general population. The RRs were similar irrespective of the sex of the sibling or index case and were particularly strong in siblings of hospitalized cases and cases that underwent surgery. The proband-wise concordance rate for monozygotic twins was double that of dizygotic twins (0.16 [95% CI, 0.11-0.22] vs 0.07 [95% CI, 0.05-0.11], respectively). The RR of diverticular disease in one twin when the other had diverticular disease was 14.5 (95% CI, 8.9-23) for monozygotic twins compared with 5.5 (95% CI, 3.3-8.6) for dizygotic twins. Associations were stronger in female monozygotic twins compared with male twins (tetrachoric correlation, 0.60 [95% CI, 0.49-0.70] vs 0.33 [95% CI, 0.13-0.51]; P = .03 in an analysis stratified by sex and zygosity). We estimate that 53% (95% CI, 45%-61%) of susceptibility to diverticular disease results from genetic factors.

CONCLUSIONS

Based on a population-based study in Denmark, genetic factors appear to contribute to development of diverticular disease.

Antibiotics for uncomplicated diverticulitis

BACKGROUND

Diverticulitis is an inflammatory complication to the very common condition diverticulosis. Uncomplicated diverticulitis has traditionally been treated with antibiotics with reference to the microbiology, extrapolation from trials on complicated intra-abdominal infections and clinical experience.

OBJECTIVES

To assess the effects of antibiotic interventions for uncomplicated diverticulitis on relevant outcome.

SEARCH METHODS

Studies were identified by computerised searches of the The Cochrane Library (CENTRAL), MEDLINE and EMBASE. Ongoing trials were identified and reference lists of identified trials and relevant review articles were screened for additional studies.

SELECTION CRITERIA

RCTs including all types of patients with a radiological confirmed diagnosis of left-sided uncomplicated diverticulitis. Interventions of antibiotics compared to any other antibiotic treatment (different regime, route of administration, dosage or duration of treatment), placebo or no antibiotics. Outcome measures were complications, emergency surgery, recurrence, late complications and duration of hospital stay and recovery of signs of infection.

DATA COLLECTION AND ANALYSIS

Two authors performed the searches, identification of RCTs, trial assessment and data extraction. Disagreements were resolved by discussion or involvement of a third part. Authors of trials were contacted to obtain additional data if needed or were contacted for preliminary results of ongoing trials. Effect estimates were extracted as relative risks (RR).

MAIN RESULTS

Three RCTs were identified. A qualitative approach with no meta analysis was performed because of variety in interventions between included studies. Interventions compared were antibiotics to no antibiotics, single to double compound antibiotic therapy and short to long IV administration. None of the studies found significant difference between the tested interventions. Risk of bias varied from low to high. The newest RCT overall had the best quality and statistical power.

AUTHORS' CONCLUSIONS

The newest evidence from one RCT says there is no significant difference between antibiotics versus no antibiotics in the treatment of uncomplicated diverticulitis. Previous RCTs have only suggested a non-inferiority between different antibiotic regimes and treatment lengths. This new evidence needs confirmation from more RCTs before it can be implicated safely in clinical guidelines. Ongoing RCTs will be published in the years to come and more are needed. The role of antibiotics in the treatment of complicated diverticulitis has not been investigated yet.

Abnormalities of neuromuscular anatomy in diverticular disease

The pathogenesis of diverticular disease is still poorly understood and considered to be multifactorial. Whereas classical pathogenetic concepts have focused on risk factors including increasing age, low-fiber diet and connective tissue disorders, novel concepts take into account that patients with diverticular disease exhibit disturbed intestinal motility patterns (that may result in functional obstruction and painful sensations) therefore postulating an underlying enteric neuro-/myopathy. Recent studies including quantitative evaluations of the enteric nervous system (ENS) in diverticular disease yielded hypoganglionic conditions of both myenteric and submucosal plexus as well as a nerve tissue remodeling in chronic diverticular disease. The disturbed neuromuscular communication was proven by demonstrating alterations in several enteric neurotransmitter systems, exemplified for the cholinergic, serotonergic, nitrergic system as well as for vasointestinal peptide, galanin and tachykinins. Novel lines of evidence have added the involvement of neurotrophic factors such as glial cell line-derived neurotrophic factor which is supposed to regulate ENS development and maintenance and which is downregulated in patients with diverticular disease. Consistent with the hypothesis of an enteric myopathy, deficits in smooth muscle integrity and composition such as hypertrophy, fibrotic transformation and gene expression deficits could be delineated. Taken together, the structural and functional findings on alterations of the ENS and the enteric musculature in diverticular disease provide evidence to strengthen the hypothesis that an enteric neuro-/myopathy may contribute to the development of colonic diverticula and the generation of symptoms in the course of the disease.

Impact of remote ischemic preconditioning on wound healing in small bowel anastomoses

AIM: To investigate the influence of remote ischemic preconditioning (RIPC) on anastomotic integrity.

METHODS: Sixty male Wistar rats were randomized to six groups. The control group (n = 10) had an end-to-end ileal anastomosis without RIPC. The preconditioned groups (n = 34) varied in time of ischemia and time of reperfusion. One group received the amino acid L-arginine before constructing the anastomosis (n = 9). On postoperative day 4, the rats were re-laparotomized, and bursting pressure, hydroxyproline concentration, intra-abdominal adhesions, and a histological score concerning the mucosal ischemic injury were collected. The data are given as median (range).

RESULTS: On postoperative day 4, median bursting pressure was 124 mmHg (60-146 mmHg) in the control group. The experimental groups did not show a statistically significant difference (P > 0.05). Regarding the hydroxyproline concentration, we did not find any significant variation in the experimental groups. We detected significantly less mucosal injury in the RIPC groups. Furthermore, we assessed more extensive intra-abdominal adhesions in the preconditioned groups than in the control group.

CONCLUSION: RIPC directly before performing small bowel anastomosis does not affect anastomotic stability in the early period, as seen in ischemic preconditioning.

Spontaneous hemoperitoneum caused by a diverticulum of the sigmoid colon

The diverticulum of the sigmoid colon is relatively common in the gastrointestinal tract, with the majority of cases being asymptomatic. A non-traumatic hemoperitoneum secondary to colonic diverticulum is very rare. Here, we report the case of a 35-year-old woman with hemoperitoneum caused by the bleeding of the serosal vessel of the sigmoid colon diverticulum. The bleeding focus was identified and ligated, and the diverticulum was invaginated laparoscopically. No blood vessel malformation was detected.

Rana catesbeiana, pólvora e modulação supramolecular cicatrização intestinal e prognóstico no câncer de cólon: uma mesma origem biológica para o insucesso?

A cicatrização e remodelação do cólon resultam das modificações do colágeno na matriz extracelular. Algumas condições desequilibram sua renovação, enfraquecendo a resistência mecânica a cicatriz, como resultado da atividade elevada das metaloproteinases locais, e levando a um alto risco de deiscência. As metaloproteinases da matriz extracelular (matrix metalloproteinases, MMPs) constituem uma família de endopeptidases zinco-dependentes - metzincinas. São reconhecidos atualmente, em humanos, cerca de 24 genes responsáveis por cada uma delas. A colagenase (MMP-1) foi identificada por Gross e Lapière (1962) na cauda do girino da rã-touro americana. No câncer as MMPs tem ocupado um lugar especial. Evidências de que a célula neoplásica é capaz de interferir na modulação desta enzima - um co-fator associado à invasividade local e disseminação metastática. As MMP-2 e -7 são observadas com frequência no câncer de cólon, a MMP-12 parece exercer um efeito protetor (melhor prognóstico) e, ao contrário, a MMP-3 o torna pior. A associação entre alta atividade de MMPs, o pior prognóstico do câncer e o maior risco de deiscência de anastomose intestinal já vem sendo considerada, sugerindo uma trilogia consistente. A terapia farmacológica (inibidores MMPs) tem sido investigada, também para o controle do câncer. O artigo discute as informações mais relevantes e atualizadas sobre o assunto.

Diet, ageing and genetic factors in the pathogenesis of diverticular disease

Diverticular disease (DD) is an age-related disorder of the large bowel which may affect half of the population over the age of 65 in the UK. This high prevalence ranks it as one of the most common bowel disorders in western nations. The majority of patients remain asymptomatic but there are associated life-threatening co-morbidities, which, given the large numbers of people with DD, translates into a considerable number of deaths per annum. Despite this public health burden, relatively little seems to be known about either the mechanisms of development or causality. In the 1970s, a model of DD formulated the concept that diverticula occur as a consequence of pressure-induced damage to the colon wall amongst those with a low intake of dietary fiber. In this review, we have examined the evidence regarding the influence of ageing, diet, inflammation and genetics on DD development. We argue that the evidence supporting the barotrauma hypothesis is largely anecdotal. We have also identified several gaps in the knowledge base which need to be filled before we can complete a model for the etiology of diverticular disease.

Nut, corn, and popcorn consumption and the incidence of diverticular disease

CONTEXT

Patients with diverticular disease are frequently advised to avoid eating nuts, corn, popcorn, and seeds to reduce the risk of complications. However, there is little evidence to support this recommendation.

OBJECTIVE

To determine whether nut, corn, or popcorn consumption is associated with diverticulitis and diverticular bleeding.

DESIGN AND SETTING

The Health Professionals Follow-up Study is a cohort of US men followed up prospectively from 1986 to 2004 via self-administered questionnaires about medical (biennial) and dietary (every 4 years) information. Men reporting newly diagnosed diverticulosis or diverticulitis were mailed supplemental questionnaires.

PARTICIPANTS

The study included 47,228 men aged 40 to 75 years who at baseline were free of diverticulosis or its complications, cancer, and inflammatory bowel disease and returned a food-frequency questionnaire.

MAIN OUTCOME MEASURES

Incident diverticulitis and diverticular bleeding.

RESULTS

During 18 years of follow-up, there were 801 incident cases of diverticulitis and 383 incident cases of diverticular bleeding. We found inverse associations between nut and popcorn consumption and the risk of diverticulitis. The multivariate hazard ratios for men with the highest intake of each food (at least twice per week) compared with men with the lowest intake (less than once per month) were 0.80 (95% confidence interval, 0.63-1.01; P for trend = .04) for nuts and 0.72 (95% confidence interval, 0.56-0.92; P for trend = .007) for popcorn. No associations were seen between corn consumption and diverticulitis or between nut, corn, or popcorn consumption and diverticular bleeding or uncomplicated diverticulosis.

CONCLUSIONS

In this large, prospective study of men without known diverticular disease, nut, corn, and popcorn consumption did not increase the risk of diverticulosis or diverticular complications. The recommendation to avoid these foods to prevent diverticular complications should be reconsidered.

Is herniosis the single etiology of Saint's triad?

BACKGROUND

Sixty years ago, Saint's triad (hiatus hernia, diverticulosis of the colon, and gallbladder disease) was first described in three patients. Since then, the association of these conditions has been questioned. We tested the hypothesis that these conditions are associated, and, based on recent research, propose a common etiology.

METHODS

Data from the U.S. Veterans Integrated Service Network (VISN) 16 Data Warehouse were analyzed. Chi-square tests and calculated odds ratios (ORs) were utilized to describe the magnitude of association, and multivariable logistic regression models were used to determine the variables associated with Saint's triad.

RESULTS

Among 637,518 patient records (1996-2005), any hernia was diagnosed among 22,181 (3.5%) patients, hiatus hernia among 1,661 (0.3%), diverticulosis of the colon among 14,375 (2.3%), and gallbladder disease among 5,284 (0.8%). The following associations were observed: diverticulosis, hiatus hernia (OR: 6.9), hiatus hernia, gallbladder disease (OR = 3.8), and gallbladder disease, diverticulosis (OR = 5.9). Patients with both diverticulosis and gallbladder disease were more likely to have hiatus hernia (OR = 3.8; P = 0.0012) or any hernia (OR = 10.7; P < 0.0001). Diseases associated with Saint's triad (incorporating any hernia) included chronic obstructive pulmonary disease (OR = 4.3), hypertension (OR = 3.1), aortic aneurysm (OR = 2.2), and diabetes (OR = 1.8).

CONCLUSIONS

Herniosis, the systemic connective tissue disease known to cause diverticulosis and herniae, may be responsible for Saint's triad. Diabetes, like aging, enhanced herniosis. Further research on the gallbladder wall pathology in patients with cholelithiasis or cholecystitis is needed.

A local imbalance between MMP and TIMP may have an implication on the severity and course of appendicitis

BACKGROUND

Matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs) have been demonstrated to be involved in inflammatory conditions in the intestine. The purpose of this study was to investigate whether the alterations of the MMP/TIMP balance might reflect the course of the inflammatory process in acute appendicitis and if the expression and localisation of MMPs and TIMP is variable in the various clinical manifestations of appendicitis.

MATERIALS AND METHODS

The study comprises 40 patients (26 men and 14 women) having emergency appendectomy and a control group constituting of 10 patients (5 men and 5 women) having a hemicolectomy for other reasons. MMP and TIMP expressions were assessed and compared in tissue specimens from phlegmonous (n = 15), gangrenous (n = 7), perforated appendicitis (n = 11) and controls with noninflamed appendices (n = 10) by means of enzyme-linked immunosorbent assay technique. Localisation of the enzymes was performed by immunohistochemistry.

RESULTS

MMP-1 was significantly higher in gangrenous and perforated appendicitis compared with phlegmonous appendicitis and controls (p < 0.05) while MMP-2 was significantly lower in gangrenous appendicitis compared with phlegmonous appendicitis and controls. MMP-2 was also lower in perforated appendicitis when compared with controls (p < 0.01). Elevated expression of MMP-9 was demonstrated in all groups of appendicitis compared with the controls (p < 0.001).

CONCLUSIONS

MMP-9 is the most abundantly expressed MMP of those investigated in inflamed appendix. We postulate that a local imbalance between MMP-9 and TIMP-1 may trigger a perforation. These results suggest that MMPs might be useful as biomarkers of appendices prone to perforation.

Different matrix micro-environments in colon cancer and diverticular disease

BACKGROUND AND AIMS

The extracellular matrix and the interactive signalling between its components are thought to play a pivotal role for tumour development and metastasis formation. An altered matrix composition as potential underlying pathology for the development of colorectal cancer was hypothesized.

METHODS

In a retrospective study of patients with colon cancer, the extracellular matrix in tumour-free bowel specimen was investigated in comparison with non-infected bowel specimen from patients operated on for colonic diverticulosis. The following matrix parameters with known associations to tumour formation, cell proliferation, invasion and metastasis were analysed by immunohistochemistry and quantified by a scoring system: VEGF, TGF-beta, ESDN, CD117, c-erb-2, cyclin D1, p53, p27, COX-2, YB-1, collagen I/III, MMP-13, PAI and uPAR. Expression profiles and correlations were calculated.

RESULTS

The comparison of the two groups revealed a significantly decreased immunostaining for CD117 and TGF-beta in the cancer group (8.5+/-2.6 vs 10.3+/-2,1 and 4.9+/-1.5 vs 8.1+/-3, respectively), whereas PAI scores were significantly higher than in patients with diverticular disease (8.1+/-1.6 vs 6.2+/-0.9). Overall correlation patterns of matrix parameters indicated pronounced differences between tumour-free tissue in cancer patients compared with patients with diverticular disease.

CONCLUSIONS

Our results indicate distinct differences in the colonic tissue architecture between cancer patients and patients with diverticulitis that support the notion of an altered matrix composition predisposing to the development of colon cancer.

Increased concentration of tissue-degrading matrix metalloproteinases and their inhibitor in complicated diverticular disease

OBJECTIVE

Complicated diverticular disease is associated with extensive structural changes of the colonic wall. Turnover of extracellular matrix (ECM) plays a pivotal role in this process. Proteolytic enzymes, including matrix metalloproteinases (MMPs), are capable of degrading most components of ECM. Their activity is regulated by inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Disturbances of the MMP-TIMP balance can cause tissue degradation or fibrosis. The aim of this study was to assess the concentration and distribution of MMPs and TIMPs in colonic biopsies.

MATERIAL AND METHODS

Twenty-seven patients who had undergone sigmoid colectomy were included in the study. Full-thickness biopsies from affected and non-affected parts of each resected specimen were collected. Expressions of the proteins MMP-1, -2, -3, -9, TIMP-1 and TIMP-2 were quantified by ELISA and localized by immunohistochemistry.

RESULTS

The concentrations of MMP-1, MMP-2 and TIMP-1 were significantly higher in affected tissue than concentrations in non-affected tissue (MMP-1 p=0.005, MMP-2 p=0.0003 and TIMP-1 p<0.0001). In affected segments in general, there was an increased expression in the entire bowel wall, predominantly for MMP-2, MMP-3 and TIMP-1.

CONCLUSIONS

Concentrations of MMP-1, MMP-2 and TIMP-1 were increased in intestinal segments affected by complicated diverticular disease and distributed throughout the entire bowel wall, which may explain the structural changes.

Collagen in colon disease

The pathophysiology of wound healing in the bowel wall suggests that collagen and matrix metalloproteinases (MMPs) have an important role in the changes of the bowel wall seen in several colonic diseases. Several recent studies suggest that disturbances of the collagen texture and the extracellular matrix (ECM) metabolism are major factors leading to the onset of diverticular disease. Changes of the ECM also play a role in the development of inflammatory bowel diseases. Regarding the permanent remodeling of the bowel wall, any imbalance of the ECM could support the onset of chronic inflammation and the development of fistula formation, such as that seen in patients with Crohn's disease. Disturbances of the ECM play a role in the pathogenesis of anastomotic leakage after large bowel surgery and suggest the presence of a genetically defined risk population with disturbed wound healing mechanisms. This concept could explain the well known situation where an anastomotic breakdown is observed, despite the absence of other known risk factors and after a technically correct anastomosis.