Distribution Of Matrix Metalloproteinases Research Articles

Similar collagen distribution in full-thickness skin grafts in intraperitoneal and onlay positions, an experimental mice-study

PurposeAutologous full-thickness skin grafting (FTSG) has the potential to become an option in abdominal wall repair. An understanding of tissue remodelling in the extracellular matrix (ECM) is crucial as this interplay determines such parameters as tissue strength and flexibility. This cross-sectional preclinical laboratory study in mice provides information on the distribution of collagen types and matrix metalloproteinases (MMPs) in the ECM of FTSGs in the intraperitoneal and onlay positions compared with internal controls. The aim was to evaluate morphologic changes after tissue remodelling and repair in FTSGs applied in the two positions and to detect any adverse host response.MethodsECM components were evaluated as follows: qualitative examination of collagen bundle thickness using Picrosirius Red staining (collagen types I, III and IV); and evaluation of collagen types IV and V, as well as MMPs 1, 8 and 9 using immunohistochemical staining. Full-thickness grafts transplanted between female twin mice were examined as this best mimics autologous transplantation.ResultsAt 8 weeks, FTSGs in the intraperitoneal position did not show any noticeable differences in morphologic appearance to those in the onlay position. Both intraperitoneal and onlay FTSGs showed increases in the amount of thick collagen bundles compared to internal controls. No correlation was seen between distribution of MMPs 1, 8 or 9 and distribution of collagen types I, III, IV or V.ConclusionThis preclinical study shows that FTSGs in both intraperitoneal and onlay positions are possible application site options and, by extension, promising application site options for abdominal wall reinforcement in hernia surgery. Clinical studies in humans are required to confirm these findings.

Noise-induced blood-labyrinth-barrier trauma of guinea pig and the protective effect of matrix metalloproteinase inhibitors

Objective: The research is to study the expression and distribution of matrix metalloproteinase (MMPs)-2 and -9 in the guinea pig cochlea after noise exposure, and to explore the role of MMPs in the blood-labyrinth-barrier (BLB). In addition, the role of MMPs inhibitor doxycycline in noise-induced BLB trauma was studied as well, which provides the basis for further studies and prophylaxis of noise-induced hearing loss. Methods: A total of 45 healthy adult guinea pigs were randomly divided into the control group (15 received intraperitoneal injection of 0.9% saline for 4 consecutive days), the noise-exposure group (15 exposed by 120 dB SPL white noise for 4 h per day for continuous 2 d, intraperitoneal injection of normal saline for 4 consecutive days) and the noise-exposure + doxycycline group (15 exposed by 120 dB SPL white noise exposure for 4 h per day for 2 consecutive days, and intraperitoneal injection of doxycycline 50 mg/kg/d for 4 consecutive days), respectively. Immunofluorescence staining, western blot, and real-time quantitative PCR were used to analyze the distribution and differential expression of MMP-2 and -9 in the stria vascularis of guinea pigs in comparison with the normal control group, noise only group, and noise & doxycycline treatment group. Immunofluorescence staining was used to observe the changes in tight junction (TJ) protein ZO-1 in stria vascularis in three groups and to investigate the effect of acoustic injury on TJs. And ABR tests were utilized to detect the hearing function of guinea pigs in the three groups. Intravenous Evans blue was administrated intravenously as an indicator of vascular leakage among three groups to study the changes in BLB permeability in context of acoustic injury. SPSS 22.0 was used for statistical analysis. Results: There was no significant difference in hearing function between the noise-exposure group and the noise & doxycycline group two hours after noise exposure. After seven, 14 and 28 days noise exposure, the hearing recovery of the noise & doxycycline treatment group was significantly greater than that of the noise-exposure group (P<0.05) . Immunofluorescence staining showed that there was only a small amount of MMP-2 and -9 in the stria vascular in the normal control group, and ZO-1 showed dense linear expression. While, in the noise-explore group, MMP-2 and -9 in the stria vascular was significantly elevated (P<0.05), and the configuration of ZO-1 became loose and discontinuous. However, the MMP-2 and -9 in the noise & doxycycline treatment group were not significantly different from the normal control group (P>0.05), which were significantly less than that in the noise-exposure group, and just a little break of ZO-1 was observed, however, the overall structure remained dense. The leakage of Evans blue from stria vascular capillary in the noise-exposure group was significantly increased, and the difference between the other two groups did not show any statistical significance (P>0.05). Conclusions: The damage of tight junction structure induced by MMP-2 and -9 may play an important role in BLB destruction. In addition, doxycycline can inhibit MMPs secretion, thereby, to some extent, protecting the integrity of BLB from acoustic injury, and contributing to the long-term hearing recovery.

ASSOCIATION BETWEEN MATRIX METALLOPROTEINASE-1 −1607 1G/2G POLYMORPHISM AND CHRONIC PERIODONTITIS IN INDONESIAN POPULATION

Objective: This study aimed to identify the distribution of matrix metalloproteinase (MMP)-1 −1607 1G/2G alleles and genotypes in subjects withchronic periodontitis and healthy subjects in a sample of Indonesian population and assess the possible association of this polymorphism withsusceptibility to chronic periodontitis.Methods: Genomic DNA samples were obtained from 200 Indonesian males aged 33–78 years old, comprising 100 chronic periodontitis patientsand 100 healthy controls. DNA fragments were amplified by a polymerase chain reaction and analyzed by restriction fragment length polymorphism.Results were analyzed by Chi-square test.Results: The frequency of the 2G allele was high both in subjects with periodontitis (87%) and in controls (91%). Analysis of MMP-1 genotype(−1607 1G/2G) showed no significant difference between the chronic periodontitis and healthy groups (p&gt;0.05).Conclusion: The result found no association between MMP-1 −1607 1G/2G polymorphism and susceptibility to chronic periodontitis in Indonesiansubjects.

The distribution of matrix metalloproteinases and their tissue inhibitors in the brain vascular bed exposed to chronic tobacco smoke

To study the distribution of MMP-2 and MMP-9 and their inhibitors (TIMP-2 and TIMP-1 respectively) in the brain vascular bed of rats exposed to chronic tobacco smoke. Localization and expression of MMP-2, MMP-9, TIMP-2 and TIMP-1 in the pial branches (I-V order vessels), intracerebral arteries and capillaries of rats exposed to tobacco smoke were studied for 36 weeks. The level of enzymatic activity was assessed by the relative quantity of enzymopositive arteries and amount of fragments per 1 mm2 and rate of immunohistochemical reaction. Specific capillary density per mm2 of brain tissue and optical density of the immunohistochemical product were calculated. MMP-2 and TIMP-2 were found in all segments of the arterial course in control animals. In rats exposed to tobacco smoking, the expression of MMP-2 increased only in intracerebral arteries and capillaries while TIMP-2 level decreased. MMP-9 and TIMP-1 were noted only in single vessels, mainly small pial and intracerebral arteries, in intact animals. In rats exposed to tobacco smoke, MMP-9 expression significantly increased in all segments of the arterial course whereas the increase in TIMP-1 was observed mainly in large pial arteries. In physiological conditions, the dynamic balance between MMP-2 and TIMP-2 maintains basic tissue metabolism. Products of tobacco combustion are inductors of the inducible MMP-9 which promotes morphofunctional changes. The imbalance in MMP-9 - TIMP-1 system causes the degradation of extracellular matrix in different segments of the brain arterial course promoting the development of cerebral dysfunction.

Distribution of Matrix Metalloproteinases in Human Atherosclerotic Carotid Plaques and Their Production by Smooth Muscle Cells and Macrophage Subsets.

PurposeIn this study, the potential of matrix metalloproteinase (MMP) sense for detection of atherosclerotic plaque instability was explored. Secondly, expression of MMPs by macrophage subtypes and smooth muscle cells (SMCs) was investigated.ProceduresTwenty-three consecutive plaques removed during carotid endarterectomy were incubated in MMPSense™ 680 and imaged with IVIS® Spectrum. mRNA levels of MMPs, macrophage markers, and SMCs were determined in plaque specimens, and in in vitro differentiated M1 and M2 macrophages.ResultsThere was a significant difference between autofluorescence signals and MMPSense signals, both on the intraluminal and extraluminal sides of plaques. MMP-9 and CD68 messenger RNA (mRNA) expression was higher in hot spots, whereas MMP-2 and αSMA expression was higher in cold spots. In vitro M2 macrophages had higher mRNA expression of MMP-1, MMP-9, MMP-12, and TIMP-1 compared to M1 macrophages.ConclusionMMP-9 is most dominantly MMP present in atherosclerotic plaques and is produced by M2 rather than M1 macrophages.

The Distribution of Matrix Metalloproteinase-2, Tissue Inhibitor of Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-4 in Psoriatic Skin

Aims: To evaluate the appearance and distribution of matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2) and tissue inhibitor of metalloproteinase-4 (TIMP-4) in lesional skin biopsies of psoriasis patients. Study Design: Observational study. Place and Duration of Study: Institute of Anatomy and Anthropology and Department of Infectology and Dermatology, Rīga Stradiņs University, between September 2013 and June 2014. Methodology: We included 40 patients (31 men, 9 women; age range 18-70 years) with Psoriasis vulgaris, with present characteristic psoriatic eruptions in typical localization sites and no treatment received. Skin samples were obtained using routine punch biopsy method. 10 clinically healthy skin samples obtained during nevus excision procedure were used as control material. All Short Research Article Sidhom et al.; BJMMR, 8(10): 883-890, 2015; Article no.BJMMR.2015.519 884 tissue specimens were stained with hematoxylin and eosin and by immunohistochemistry for MMP2, TIMP-2 and TIMP-4. The intensity of staining was graded semiquantitatively. Spearman’s rank correlation coefficient was calculated. Results: In psoriasis patients numerous MMP-2-containing keratinocytes were found in epidermis, MMP-2 positive dermal fibroblasts and inflammatory cells varied from few to abundant. Few epidermal cells and moderate to numerous dermal cells contained TIMP-2. Moderate to numerous epidermal and dermal cells contained TIMP-4. Statistically significant strong positive correlation was found between MMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .878, P = .000). Statistically significant moderate positive correlation was found between TIMP-2 and TIMP-4 in dermis (Spearman’s rank correlation coefficient = .639, P = .000) and between TIMP-2 in epidermis and dermis (Spearman’s rank correlation coefficient = .564, P = .000). Conclusion: TIMP-4 seems to be most important inhibitor of psoriatic skin degeneration, richly raised by MMP-2. Its moderate correlation with TIMP-2 proves involvement of other tissue inhibitors in the degeneration inhibition and gives evidence about possible patterning between the tissue inhibitors of metalloproteinases.

Localization and quantitative detection of matrix metalloproteinase in human coronal dentine

To compare the distribution and concentrations of matrix metalloproteinase (MMP)-1, 2, 3, 8, 9 in human coronal dentin. The localization of five types of MMP was performed using immunohistochemistry. Molars were demineralized and sectioned into 5 µm thick specimens. All specimens were randomly divided into five groups according to the antibodies. Each group contained two subgroups (n = 6). Immunoreactivity of each subgroup was visualized with 3, 3-diaminobenzidine solution or fluorescein isothiocyanate and observed under microscopy respectively. Molars were sectioned into slices. The slices were divided into two groups according to superficial or deep dentin and pulverized to fine powder. After dentin protein was extracted, the concentrations of MMP-1, 2, 3, 8, 9 were detected by using fluorescent microsphere immunoassay. Immunohistochemical staining revealed that MMP-1, 2, 3, 8, 9 were highly concentrated in the deep dentin. However, intense immunoreactivities of MMP-2, 8, 9 were identified in a 6-10 µm wide zone adjacent to the dentino-enamel junction. The content of MMP-1 in superficial layer and deep layer of dentin were (0.037±0.025) and (0.433±0.089) ng/mg. The content of MMP-2 in superficial layer and deep layer of dentin were (0.445±0.115) and (2.730±0.712) ng/mg. The content of MMP-3 in superficial layer and deep layer of dentin were (0.071±0.069) and (0.460±0.108) ng/mg. The content of MMP-8 in superficial layer and deep layer of dentin were (0.586±0.246) and (6.159±0.948) ng/mg. The content of MMP-9 in superficial layer and deep layer of dentin were (0.384±0.185) and (1.460±0.251) ng/mg. The concentrations of all tested MMP were significantly higher in deep dentin than those in superficial dentin (P < 0.05). There are five types of MMP contained in human coronal dentin, and the distribution of MMP shows a decreasing trend from the deep dentin to the superficial dentin.

Multiple Target-Specific Molecular Imaging Agents Detect Liver Cancer in a Preclinical Model

Liver cancer is the fifth most common cause of cancer deaths worldwide. Noninvasive diagnosis is difficult and the disease heterogeneity reduces the accuracy of pathological assays. Improvement in diagnostic imaging of specific molecular disease markers has provided hope for accurate and early noninvasive detection of liver cancer. However, all current imaging technologies, including ultrasonography, computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, are not specific targets for detection of liver cancer. The aim of this study was to test the feasibility of injecting a cocktail of specific molecular imaging agents to noninvasively image liver cancer. The target-specific cocktail contained agents for imaging the neovasculature (RGD peptide), matrix metalloproteinase (MMP), and glucose transport (18F-fluorodeoxyglucose [18F-FDG]). Imaging studies were performed in liver cancer cells and xenograft models. The distribution of MMP at the intracellular level was imaged by confocal microscopy. RGD, MMP, and 18F-FDG were imaged on tumor-bearing mice using PET, CT, X-ray, and multi-wavelength optical imaging modalities. Image data demonstrated that each agent bound to a specific disease target component. The same liver cancer xenograft contained multiple disease markers. Those disease markers were heterogenetically distributed in the same tumor nodule. The molecular imaging agents had different distributions in the whole body and inside the tumor nodule. All target-specific agents yielded high tumor-to-background ratios after injection. In conclusion, target-specific molecular imaging agents can be used to study liver cancer in vitro and in vivo. Noninvasive multimodal/multi-target-specific molecular imaging agents could provide tools to simultaneously study multiple liver cancer components.

Expressão de MMP-2 e MMP-9 no endométrio de éguas saudáveis e portadoras de endometrite crônica

Avaliaram-se, por método imunoistoquímico, a expressão e distribuição das metaloproteinases (MMP) 2 e 9 em amostras de endométrio hígido e de éguas portadoras de endometrite crônica. Foram utilizadas 60 biópsias endometriais. A MMP-2 foi observada na parede vascular, nas células estromais e no epitélio glandular, e a imunorreatividade mais intensa foi obtida nas células do epitélio glandular nas endometrites da categoria III e na parede vascular nos endométrios da categoria I. A marcação imunoistoquímica para MMP-9 mostrou-se difusa pelo endométrio e foi observada no epitélio luminal e glandular, na região da parede vascular, nas células estromais, endoteliais e do infiltrado inflamatório. Houve diminuição da marcação imunoistoquímica na região da parede vascular conforme aumentou o grau das lesões endometriais concomitante à diminuição da intensidade da reação. Não houve relação na expressão imunoistoquímica das metaloproteinases estudadas com o tipo de endometrite

Inhibitory effect of N-acetylcysteine upon atherosclerotic processes in rabbit carotid

To discuss the effect of N-acetylcysteine (NAC) upon matrix metalloproteinases (MMP) in the atherosclerotic processes in rabbit carotid. The atherosclerotic models were generated in vitro by injuring rabbit internal carotid with arterial canal balloon. These rabbits were divided into 3 groups (15 mg/kg NAC, 30 mg/kg NAC and control group) and treated for 8 weeks. HE staining and immunohistochemistry were used to observe the plaque formation and the distribution of MMPs and ox-LDL. ELISA was used to detect the level of ox-LDL. And the protein levels of MMP-2 and MMP-9 in rabbit venous blood were detected by SDS PAGE zymography. The mRNA level of MMP-2 and MMP-9 were measured by RT-PCR and electrophoresis. As compared with the control group, NAC (15 mg/kg) group had a reduction of neointima of arterial lumen [(1.79 +/- 0.24) vs (2.78 +/- 0.17) mm2]. A decrease of endothelial thickness [(0.16 +/- 0.01) vs (0.24 +/- 0.02) mm2] and an increase of vascular cavity transverse [(0.58 +/- 0.10) vs (0.33 +/- 0.1) mm2] (P < 0.05) were observed. At week 8, the oxLDL levels decreased by 16% in NAC (30 mg/kg) group [(30.5 +/- 1.2) vs (36.2 +/- 1.8) mmol/L] (P < 0.01). Serum levels of pro-MMP-2, MMP-2 and pro-MMP-9 decreased markedly [INT/mm2: (311 +/- 19, 208 +/- 8, 283 +/- 7 vs 619 +/- 17, 574 +/- 8, 564 +/- 10) respectively, P < 0.01] in NAC (30 mg/kg) group. The levels of mRNA expression of MMP-2 and MMP-9 were (2.4 +/- 0.4, 2.8 +/- 0.2) vs (3.4 +/- 0.3, 3.7 +/- 0.5) respectively (P < 0.05). NAC inhibits the atherosclerotic formation, suppresses the levels of ox-LDL, MMP-9 and MMP-2 and downgrades the expression of matrix metalloproteinase mRNA.

Atherosclerosis and Matrix Metalloproteinases: Experimental Molecular MR Imaging in Vivo

To evaluate the capability of P947, a magnetic resonance (MR) imaging contrast agent that molecularly targets matrix metalloproteinases (MMPs), to aid detection and imaging of MMPs in atherosclerotic lesions in vivo; its specificity compared with that of P1135; expression and distribution of MMPs in atherosclerotic vessels; and in vivo distribution and molecular localization of fluorescent europium (Eu) P947. The Animal Care and Use Committee approved all experiments. P947 was synthesized by attaching a gadolinium chelate (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) to a peptide that specifically binds MMPs. Scrambled form of P947 (P1135) was synthesized by replacing the targeting moiety of P947 with a scrambled peptide lacking the ability to bind MMPs. P947, P1135, and gadoterate meglumine were injected into atherosclerotic apolipoprotein E-deficient and wild-type mice. The aortic MR imaging enhancement produced by the contrast agents was measured at different times and was compared by using one-way analysis of variance. MMP expression was investigated in the aortas by using MMP immunostaining and in situ MMP zymography. A fluorescent form of P947 (Eu-P947) was synthesized to compare the in vivo distribution of the contrast agent (Eu-P947) with specific MMP immunofluorescent staining. MMP-targeted P947 facilitated a 93% increase (P < .001) in MR image signal intensity (contrast-to-noise ratio [CNR], 17.7 compared with 7.7; P < .001) of atherosclerotic lesions in vivo. Nontargeted P1135 (scrambled P947) provided 33% MR image enhancement (CNR, 10.8), whereas gadoterate meglumine provided 5% (CNR, 6.9). Confocal laser scanning microscopy demonstrated colocalization between fluorescent Eu-P947 and MMPs in atherosclerotic plaques. Eu-P947 was particularly present in the fibrous cap region of plaques. P947 improved MR imaging for atherosclerosis through MMP-specific targeting. The results were validated and provide support for further assessment of P947 as a potential tool for the identification of unstable atherosclerosis.

Pathological findings in rats with experimental allergic encephalomyelitis

The aim of this study was to establish an animal model of experimental allergic encephalomyelitis (EAE) and examine the basic pathological changes, as well as expression and distribution of MMP-2 and MMP-9, in Wistar rats. Tissue sections were processed for HE staining, Weil myelin staining, and modified Bielschowsky staining. Expression and distribution of glial fibrillary acidic protein (GFAP), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) were detected with immunohistochemistry. We divided the EAE into five types, depending on pathological characteristics and clinical manifestations: acute EAE, relapsing-remitting EAE, progressive EAE, benign EAE, and asymptomatic EAE. Rats with acute EAE suffered from quick, severe attacks with widespread inflammatory cells and axonal loss. No demyelination or astrocytic hyperplasia was found around the lesions. Rats with relapsing-remitting EAE broke down twice, with many perivascular cuffs and demyelinating plaques in lesions; hyperplastic and hypertrophic astrocytes characterized old lesions and axonal loss was evident. Rats suffering from progressive EAE exhibited continuous aggravation without improvement, accompanied by perivascular cuffs, demyelination, increased gliocytes and axonal damage. Rats with benign EAE recovered to a normal state with obviously decreased inflammatory cells and almost entirely unaffected myelin and axons. Rats with asymptomatic EAE also had various pathological changes that were not coincident with their clinical manifestations. Elevated expression of MMP-2 and MMP-9 was concordant in different types of EAE, but the extent differed in each type of EAE. MMP-2 and MMP-9 can be expressed in the form of vascular endothelial cells, meninges, or accumulated inflammatory cells. Multiple clinical courses of disease were demonstrated in Wistar rat EAE, with attributes similar to multiple sclerosis (MS) in clinical and pathological characteristics. Elevated expression of MMP-2 and MMP-9 may play a role in some aspects of pathological changes in EAE, for example, destroying the blood-brain barrier, degrading the myelin sheath, and damaging axons.

Expression and distribution of MMPs and TIMPs in human uveal melanoma

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are involved in tumour invasion, metastasis and angiogenesis, and have been implicated as progression markers in uveal melanoma, although their topographical expression has not been fully described. In this study we compared the distribution and specificity of several classes of MMPs (MMP-1, -2, -9, -19, and MT1-MMP) and physiological MMP inhibitors (TIMP-2 and -3) in different regions of the tumour microenvironment and adjacent choroid in a series of primary uveal melanomas. Paraffin sections of untreated uveal melanomas ( n = 18, 3/18 spindle; 11/18 mixed, and 4/18 epithelioid) were examined for MMP-1 (collagenase 1), MMP-2 and MMP-9 (gelatinases A and B), MT1-MMP (membrane-type 1-MMP), MMP-19, TIMP-2 and TIMP-3 (tissue inhibitors of MMPs), using indirect peroxidase immunohistochemistry. The distribution and intensity of immunolabelling was graded semi-quantitatively (0–3) by 2 independent observers. Non-parametric analyses were used to test for associations between tumour cell type, and the average grade of MMP or TIMP expression. Immunostaining for MMP-1, -9, -19 and MT1-MMP was ≥Grade 2 in more than 70% of specimens, and a heterogeneous pattern of MMP-1, -9, MT1-MMP and TIMP-3 expression was observed. At the tumour-scleral interface (TSI), melanoma cells had a flattened morphology and a much reduced MMP and TIMP expression, with a high expression in tumour areas adjacent to the TSI. Tumour vasculature and stromal cells strongly expressed MMP-2. We also observed heterogeneous immunostaining of the vasculature by MMP-1, -9, MT1-MMP and TIMP-2 antibodies, and of the extravascular matrix by MMP-9 antibody. The distinct immunostaining patterns observed for MMPs and TIMPs within uveal melanoma are consistent with their involvement in tumour growth and angiogenesis. In particular, the heterogeneous expression within regions of the tumours, and the localized expression in vasculature and stromal cells emphasises the importance of the tumour microenvironment in the pathogenesis of uveal melanoma (and other tumours).

Matrix metalloproteinases-2, -3 and -9 in human term placenta

Matrix metalloproteinases (MMPs) are zinc-dependent enzymes that degrade the components of the extracellular matrix (ECM) and are known to be the main mediators of human placentation and parturition. Although there are many studies on the roles and distribution of MMPs in human term placenta, so far none of the studies has investigated the distribution of MMP-2, -3 and -9 in different cells of various placental sites. In this study, we aimed to determine the distribution and enzymatic activities of MMP-2, -3 and -9 with regard to different regions of term human placenta, such as amnion, basal plate, chorionic plate, decidua, chorion laeve, Nitabuch's stria, umbilical cord and placental villi. Eighteen normal human term placentas were obtained after vaginal deliveries. Immunohistochemistry and zymography were performed for MMP-2, -3 and -9 on placental tissue sections and protein extracts, respectively. Nearly all tissues showed immunoreactivity for MMPs. The strongest enzymatic activity for MMP-2 was seen in areas where invasive trophoblast cells invaded maternal tissues. MMP-9 had the highest enzymatic activity at the contact region of fetal and maternal parts, suggesting the importance of MMP-9 in separation of the placenta from the uterine wall during labor. MMP-3 had a similar localization to MMP-9, suggesting that besides gelatinases like MMP-2 and -9, MMP-3 (stromelysin-1) may also have important roles during labor. This study describes the site-specific distribution and activities of MMPs and therefore might help in elucidating the molecular mechanisms in pathologies such as premature rupture of membranes.

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 andmethods. 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.

The distribution of matrix metalloproteinases and tissue inhibitors of metalloproteinases in the lungs of congenital diaphragmatic hernia patients and age‐matched controls

In congenital diaphragmatic hernia (CDH), the pathogenesis of abnormal pulmonary morphology is still incompletely understood. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are known to play an important role in the turnover of the extracellular matrix (ECM) during development and in remodelling of tissue. The aim of this study was to investigate differences in the expression of MMPs and TIMPs between CDH lungs and controls, against the background of the abnormal pulmonary vasculature in CDH. We studied 12 lungs of term CDH patients who died < 24 h after birth and 11 normal age-matched control lungs, by immunohistochemistry with antibodies against human MMP-1, -2, -9, TIMP-1 and -2. There was a clear increase in the number of MMP-1-reactive capillaries and fibroblasts in CDH lungs compared with controls. In contrast, TIMP-2 reactivity in these structures was decreased in CDH lungs. The arterial endothelium and medial smooth muscle expressed MMP-2, -9 and TIMP-2 in both CDH and control lungs. In small arteries (< 100 microm in diameter), the positive surface area of MMP-2, -9 and TIMP-2 was significantly larger in CDH lungs than in controls. There was no difference in the distribution and expression of TIMP-1 between CDH lungs and normal controls. The differences in staining pattern of MMPs and TIMPs between normal and CDH lungs suggest that these enzymes might play a role in the abnormal remodelling of the interstitium and the pulmonary arteries in CDH lungs. This could contribute to our understanding of the abnormal lung morphology and the occurrence of pulmonary hypertension, which forms one of the major obstacles to the successful treatment of these patients.

Distribution of matrix metalloproteinase-2, -9 and their inhibitors in the human decidual stroma during early pregnancy and ultrastructural findings

Human implantation and subsequent placental development require the invasion of trophoblast cells into the maternal endometrium. The invasive ability of trophoblast cells is mediated by matrix degradation enzymes, matrix metalloproteinases (MMPs), among which the type IV collagenases (MMP-2 and MMP-9) play major roles. During the invasion process, the behavior of cytotrophoblast cells is similar to that of malignant cells, except that their invasion is precisely regulated. For controlled cellular invasion, the balance between protease activation and inhibition is maintained by a group of endogenous tissue inhibitors of metalloproteinases (TIMPs).

Titanium implants induce expression of matrix metalloproteinases in bone during osseointegration

Implanted pure titanium fixtures are able to completely integrate with bone, in part because of the formation of a strong extracellular matrix (ECM) bond at the titanium-bone interface. In this study, we used a rodent femur model of intramedullary osseointegration to analyze the changes in immunoreactivity of ECM-controlling matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinase-3 (TIMP-3), and tumor necrosis factor alpha (TNF-alpha) during osseointegration. We observed dramatic increases in MMP-2, MMP-9, MMP-7, TIMP-3, and TNF-alpha in osteocytes, osteoclasts, haversian canals, and the interface matrix in bone ipsilateral to the titanium implant. An increase in TIMP-3, MMP-9, and MMP-7 in hypertrophied chondrocytes and the vascular component of the epiphysial growth plate was also observed in experimental bone. These findings were not seen in contralateral or sham-operated bone, where the titanium fixtures were threaded into the femur and immediately removed. Our data link titanium-induced bone remodeling to changes in expression and distribution of MMPs.

Effect of colonic obstruction on the distribution of matrix metalloproteinases during anastomotic healing.

Anastomotic dehiscence is common after surgery for colonic obstruction. The strength of an anastomosis is dependent on collagen, which is degraded by matrix metalloproteinases (MMPs). The aim of this study was to determine the distribution of the MMPs and their inhibitor, tissue inhibitor of metalloproteinases (TIMP) 1 in an experimental model of colonic obstruction, with and without resection and anastomosis. The distal colon of rabbits was obstructed with a Silastic ring for 24 h and then either the ring was removed or the obstructed segment was resected and an anastomosis formed. Rabbits were killed immediately or at intervals for up to 7 days after operation. The distribution of the MMPs and TIMP-1 was examined by indirect immunofluorescence. MMPs and TIMP-1 were present throughout the descending colon for 24 h in both groups. They persisted to the third day in rabbits with an anastomosis but by day 7 were restricted to the suture line. Their presence correlated with microscopic damage. The extensive distribution of the MMPs suggests that these enzymes contribute to anastomotic dehiscence, but only in the immediate postoperative period.

Regulation of matrix metalloproteinases in a model of colonic wound healing in a rabbit.

Matrix metalloproteinases occur in the colon at an anastomosis but not in the normal colon. Matrix metalloproteinase synthesis can be regulated by cytokines, for example interleukin-1 beta and growth factors, such as transforming growth factor beta and basic fibroblast growth factor. The aim of this study was to investigate the regulation of matrix metalloproteinases at an anastomosis by identifying the cell types that synthesize matrix metalloproteinases, examining factors that might regulate their synthesis, determining whether they occur in an active form, and assessing the effect of suture type on these parameters. An anastomosis was formed in the distal colon of rabbits using either polyglactin or polydioxanone and the animals were killed six hours or seven days later. The distribution of matrix metalloproteinases and cytokines and the cell types were assessed by immunohistochemistry. Matrix metalloproteinase-2, matrix metalloproteinase-3, and matrix metalloproteinase-9 were detected also by zymography. Immunohistochemistry showed that matrix metalloproteinases were restricted to the suture line. Although zymography demonstrated that matrix metalloproteinase-2 was present mainly in an active form, matrix metalloproteinase-9 and matrix metalloproteinase-3 were present in the pro-form. The active form of matrix metalloproteinase-3 occurred more often in the polydioxanone-sutured rabbits. With the exception of matrix metalloproteinase-9, the matrix metalloproteinases were synthesized by fibroblasts. Interleukin-1 beta and transforming growth factor beta were more widespread than in the normal colon and were localized adjacent to the matrix metalloproteinases. Basic fibroblast growth factor was also more widespread postoperatively but occurred deeper in the anastomosis than the matrix metalloproteinases. This study has shown that interleukin-1 beta and transforming growth factor beta may regulate the synthesis of the matrix metalloproteinases by fibroblasts and that minor differences that occur in the matrix metalloproteinase profile are dependent on the suture type.