Granzyme B promotes matrix metalloproteinase-1 (MMP-1) release from gingival fibroblasts in a PAR1- and Erk1/2-dependent manner: A novel role in periodontal inflammation

OBJECTIVE

To gain insights into how proteases signal to connective tissues cells in the periodontium.

BACKGROUND

The connective tissue degradation observed in periodontitis is largely due to matrix metalloproteinase (MMP) release by gingival fibroblasts. Granzyme B (GzmB) is a serine protease whose role in periodontitis is undefined.

METHODS

Human gingival crevicular fluid (GCF) samples were obtained from sites with periodontal disease and healthy control sites. GzmB was quantified in the GCF ([GzmB]GCF ) by ELISA. Gingival fibroblasts (GF) were cultured in the presence or absence of recombinant GzmB. Culture supernatants were analyzed by ELISA to quantify GzmB-induced release of interstitial collagenase (MMP-1). In some experiments, cells were pre-treated with the inhibitor PD98059 to block MEK/ERK signaling. The protease-activated receptor-1 (PAR-1) was blocked with ATAP-2 neutralizing antibody prior to GzmB stimulation. Systemic MMP-1 levels were measured in plasma from wild-type (WT) and granzyme-B-knockout (GzmB-/- ) mice.

RESULTS

The [GzmB]GCF in human samples was ~4-5 fold higher at sites of periodontal disease (gingivitis/periodontitis) compared to healthy control sites, suggesting an association between GzmB and localized matrix degradation. GzmB induced a ~4-5-fold increase in MMP-1 secretion by cultured fibroblasts. GzmB induced phosphorylation of Erk1/2, which was abrogated by PD98059. GzmB-induced upregulation of MMP-1 secretion was also reduced by PD98059. Blockade of PAR-1 function by ATAP-2 abrogated the increase in MMP-1 secretion by GF. Circulating MMP-1 was similar in WT and GzmB-/- mice, suggesting that GzmB's effects on MMP-1 release are not reflected systemically.

CONCLUSION

These data point to a novel GzmB-driven signaling pathway in fibroblasts in which MMP-1 secretion is upregulated in a PAR1- and Erk1/2-dependent manner.

IL-40: A New B Cell-Associated Cytokine Up-Regulated in Rheumatoid Arthritis Decreases Following the Rituximab Therapy and Correlates With Disease Activity, Autoantibodies, and NETosis

Background

Interleukin 40 (IL-40) is a newly identified B cell-associated cytokine implicated in humoral immune responses and B cell homeostasis. As B cells play a pivotal role in autoimmunity, we investigated the function of IL-40 in rheumatoid arthritis (RA).

Methods

IL-40 expression was determined in the synovial tissue from RA and osteoarthritis (OA) patients. IL-40 was analysed in the serum/synovial fluid of patients with RA (n=50), systemic lupus erythematosus (SLE, n=69), OA (n=44), and healthy controls (HC, n=50). We assessed the changes of IL-40 levels in RA patients following the B cell depletion by rituximab (n=29) or after the TNF inhibition by adalimumab (n=25). We examined the relationship between IL-40, disease activity, autoantibodies, cytokines, and NETosis markers. Effect of IL-40 on synovial fibroblasts was determined.

Results

IL-40 was overexpressed in RA synovial tissue, particularly by synovial lining and infiltrating immune cells. The levels of IL-40 were up-regulated in the synovial fluid of RA versus OA patients (p<0.0001). Similarly, IL-40 was increased in the serum of RA patients compared to HC, OA, or SLE (p<0.0001 for all) and decreased after 16 and 24 weeks (p<0.01 and p<0.01) following rituximab treatment. No significant effect of adalimumab on IL-40 was observed. IL-40 levels in RA patients correlated with rheumatoid factor-IgM and anti-cyclic citrullinated peptides (anti-CCP) in the serum (p<0.0001 and p<0.01), as well as in the synovial fluid (p<0.0001 and p<0.001). Synovial fluid IL-40 was also associated with disease activity score DAS28 (p<0.05), synovial fluid leukocyte count (p<0.01), neutrophil attractants IL-8 (p<0.01), MIP-1α (p<0.01), and markers of neutrophil extracellular traps externalization (NETosis) such as proteinase 3 (p<0.0001) and neutrophil elastase (p<0.0001). Synovial fibroblasts exposed to IL-40 increased the secretion of IL-8 (p<0.01), MCP-1 (p<0.05), and MMP-13 (p<0.01) compared to the unstimulated cells.

Conclusions

We show the up-regulation of IL-40 in RA and its decrease following B cell depleting therapy. The association of IL-40 with autoantibodies, chemokines, and markers of NETosis may imply its potential involvement in RA development. Moreover, IL-40 up-regulates the secretion of chemokines and MMP-13 in synovial fibroblasts, indicating its role in the regulation of inflammation and tissue destruction in RA.

Corneal Cross-Linking Has No Effect on Matrix Metalloproteinase 9 and 13 Levels During Fungal Keratitis on the Early Stage

The aim of our study was to investigate matrix metalloproteinases, MMP-9 and MMP-13 levels, in the rabbit model of Fusarium and Candida keratitis treated by corneal cross-linking (PACK-CXL). Rabbit corneas were inoculated with fungal inoculum for keratitis. Each group divided into four subgroups, including un-treated group, PACK-CXL group, voriconazole group and PACK-CXL plus voriconazole group. PACK-CXL was applied with 0.25% riboflavin in accelerated Dresden protocol, and 0.1% voriconazole drops were administered. All corneal buttons excised at tenth day after ophthalmological examination. Fungal cell counts and Scheiber scores were determined in all groups. Corneal tissue MMP mRNA levels were evaluated quantitative reverse transcriptase PCR. The difference in MMP-9 and MMP-13 levels at all groups was not statistically significant (p > 0.05). PACK-CXL with 0.25% riboflavin either alone or combined with antifungal drops was unable to provide decline in inflammatory findings in both macroscopic and microscopic levels similar to medical antifungal treatment.

Long-term effects of hydrogen sulfide on the anabolic-catabolic balance of articular cartilage in vitro

Healthy cartilage maintenance relies on an equilibrium among the anabolic and catabolic processes in chondrocytes. With the onset of osteoarthritis (OA), increased interleukin (IL)-1β levels induce an inhibition of the synthesis of extracellular matrix (ECM) proteins, as well as an increase in proteases. This eventually leads to a predominance of the catabolic phenotype and the progressive loss of articular cartilage. Hydrogen sulfide (H₂S) is a small gaseous molecule recognized as the third endogenous gasotransmitter. When administered exogenously, it has shown anti-inflammatory and anti-catabolic properties in several in vitro and in vivo models. Here, OA cartilage disks were co-cultured in vitro with IL-1β (5 ng/ml) and NaSH or GYY4137 (200 or 1000 μM) for 21 days. The ability of these two H₂S-producing compounds to avoid long term extracellular matrix (ECM) destruction was evaluated. We used a glycosaminoglycan (GAG) quantification kit histology and immunohistochemistry (IHC) to evaluate matrix proteins degradation and matrix metalloproteinases (MMP) abundance. Through the GAGs quantification assay, safranin O (S-O) and toluidine blue (TB) stains, and keratan/chondroitin sulfate (KS/ChS) IHCs it was shown that co-stimulation with H₂S-forming reagents effectively avoided GAGs destruction. Both Masson's trichrome (MT) stain and collagen (col) type II IHC, as well as aggrecan (agg) IHC demonstrated that not only were these proteins protected but even promoted, their abundance being higher than in the basal condition. Further, stains also demonstrated that positivity in the inter-territorial and intra-cellular for the different matrix components were rescued, suggesting that NaSH and GYY4137 might also have pro-anabolic effects. In addition, a clear protective effect against the increased MMPs levels was seen, since increased MMP3 and 13 levels were subsequently reduced with the co-stimulation with sulfide compounds. In general, GYY4137 was more effective than NaSH, and increasing the dose improved the results. This study demonstrates that H₂S anti-catabolic effects, which had been previously proven in short-term (24-48 h) in vitro cellular models, are maintained over time directly in OA cartilage tissue.

Krüppel-Like Factor 2 Regulates Degradation of Type II Collagen by Suppressing the Expression of Matrix Metalloproteinase (MMP)-13

BACKGROUND/AIMS

Krüppel-like factor 2 (KLF2) plays an essential role in the inhibition of endothelial cell and macrophage activation during the inflammatory process. However, the roles of KLF2 in chondrocytes and the pathological progression of osteoarthritis (OA) remain unknown. The aim of this study was to investigate the function of KLF2 in the inhibition of cartilage matrix destruction in chondrocytes.

METHODS

RT-PCR and western blot analysis was used to determine the expression of KLF2 in human chondrocytes. Luciferase assay, ELISA assay and MMP-13 enzymatic activity assays were used to investigate the effects of KLF2 in regulating MMP-13 expression. Western blot analysis was used to examine the effects of KLF2 in suppressing degradation of type Ⅱ collagen.

RESULTS

KLF2 is expressed in primary chondrocytes and is downregulated in OA chondrocytes. Expression of KLF2 in primary chondrocytes was reduced in response to IL-1β. Overexpression of KLF2 robustly inhibited IL-1β-induced MMP-13 expression. Conversely, knockdown of KLF2 markedly exacerbated MMP-13 expression. Mechanistically, KLF2 could suppress the activation of MMP-13 promoter. However, knockdown of KLF2 could promote the activation of MMP-13 promoter. Importantly, overexpression of KLF2 ameliorated the degradation of type Ⅱ collagen while silencing of KLF2 exacerbated the degradation of type Ⅱ collagen induced by IL-1β.

CONCLUSIONS

KLF2 may be a potential therapeutic target for OA treatment.

[Research on application of determination of MMP-13 in osteoarthritis]

Osteoarthritis (OA) is a complex chronic progressive disease attacked by biological and mechanical factors and a result from the anabolic and catabolic imbalance in chondrocyte, subchondral bone and extracellular matrix(ECM). Etiology and pathological of OA are not yet entirely clear. The degradation and destruction of collagen II caused by matrix metalloproteinase -13 (MMP-13) is considered the core factor in the occurrence and development of OA. The research of MMP-13 inhibitor provide ideas and methods for the treatment of OA. In this article,the role and determination of MMP-13 in OA and the development prospect of MMP-13 inhibitor in the treatment of OA research progress were reviewed.

Increased expression of matrix metalloproteinase-13 in glioma is associated with poor overall survival of patients

Glioma is the most common and aggressive tumor in human central nervous system. MMP-13 plays an important role in tumor aggressive process for it can degrade the extracellular matrix of basement membranes. The present study was to investigate the expression of MMP-13 in clinical glioma samples and its association with clinicopathological characteristics as well as survival of patients. Clinical glioma samples from 286 patients who had not received chemotherapy or radiotherapy were collected, in which MMP-13 expression was assessed by immunochemistry assays. The association of staining evaluation results with clinicopathological characters was analyzed by appropriate statistical analysis. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the associations of MMP-13 expression with survival of patients. Results showed that MMP-13 expression was increased in glioma and associated with tumor progression for its expression increased from grade I to grade IV glioma (P<0.001). Kaplan-Meier analysis showed that patients of glioma with higher MMP-13 expression tend to have shorter overall survival time (P<0.001). In multivariate analysis, MMP-13 expression was proved to be an independent prognostic factor for patients with glioma (P<0.001). The present study confirmed the over-expression of MMP-13 and its association with tumor progression in glioma. It also provided the first evidence that MMP-13 expression in glioma was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of glioma.

Specific signaling molecule expression in periodontal ligaments in different age groups: pilot study

INTRODUCTION. Orthodontic teeth movement is accompanied by remodeling of alveolar bone, including the interradicular septum and periodontal ligaments (PDL). Periodontal signaling molecules have important functions during tooth movement and they are active in the bone remodeling process. Patients involved in orthodontic treatment belong to different age groups: therefore age must be considered as a contributing factor compromising the remodeling potential of periodontal tissues. The aim of the current study was to investigate the specific expression of signaling molecules in the PDL of interradicular septum in patients from different groups of age. MATERIALS AND METHODS. The study group included 25 patients to whom extractions of teeth was recommended as a part of further orthodontic treatment. 25 patients (10 males and 15 females) were divided into three groups as follows: 1) 12-14 years old; 2) 15-22 years old; and 3) 23 years old or older. The routine histological method was followed and samples were stained with hematoxyline-eosine. According to literature data in current immunohistochemical study were included and examined expression of NGFR (nerve growth factor receptor), TGF-β (transforming growth factor β), bFGF (basic fibroblast growth factor), FGFR1 (fibroblast growth factor receptor), IL-1 (interleukin 1), IL-6 (interleukin 6), IL-8 (interleukin 8), MMP-1 (matrix metalloproteinase 1), MMP-2 (matrix metalloproteinase 2), MMP-8 (matrix metalloproteinase 8), MMP-9 (matrix metalloproteinase 9), MMP-13 (matrix metalloproteinase 13) in PDL of interradicular septum. The distribution of these factors was evaluated semi quantitatively. RESULTS. Expression levels of FGFR1, bFGF, MMP 8 and 9, and IL-6 in PDL of interradicular septum structure were determined in all samples. Decreases in the mean values of signaling factors relevant to age were statistically significant in bFGF. CONCLUSIONS. Analyzed data suggest that bFGF, FGFR, IL-6, MMP 8 and 9 were determined as signaling factors in PDL of interradicular septum. Mean expression level decrease with age of FGFR1, IL-6, MMP-8, MMP-9 was non- statistically significant. The mean expression level of bFGF decreased with age, and this decrease was statistically significant. In younger patients, signal molecule expression is higher because of increased PDL metabolic activity. Increased PDL metabolic activity is a reason for higher expression of signal molecule in younger patients. Activity of remodeling process of periodontal tissue decreases with the aging and expression of signaling molecule decreases in adults.

Specific signaling molecule expressions in the interradicular septum in different age groups

INTRODUCTION

Orthodontic teeth movement is accompanied by the remodeling of alveolar bone, including the interradicular septum. Bone contains three cell types, osteoblasts, osteocytes, and osteoclasts that are in direct contact with all of the cellular elements in the bone marrow. Marrow is the source of both bone-building osteoblasts and bone destroying osteoclasts, and the turnover of bone occurs throughout life. Bone signalling molecules have important functions during osteogenesis, and they are active in the bone remodelling process. Patients involved in orthodontic treatment belong to different age groups: therefore age must be considered as a contributing factor compromising the osteogenetic potential of bone. The aim of the current study was to investigate the specific expression of signalling molecules in the interradicular septum in different age groups.

MATERIALS AND METHODS

The study group included 17 patients to whom the extraction of teeth was recommended as part of further orthodontic treatment. Patients (9 males and 8 females) - were divided into 3 groups 1st group - 12-14 years old); 2nd group - 15-22 years old; 3rd group - 23 years old or older. Expression of BMP 2/4, TGF-α, IL-1, IL-8, OPG, MMP-1, MMP-2, MMP-8, MMP-9, MMP-13, NGFR, NKpB 105, osteocalcin, and osteopontin in interradicular septum tissues was examined. TUNEL staining was also completed. The distribution of these factors was evaluated semi quantitalively.

RESULTS

In the interradicular septum bone structure, the expression levels of osteocalcin, osteoprotegerin, matrix metalloproteinases 8 and 9, and nuclear factor kappa B were determined in all samples. TUNEL staining was also done. Age related decreases in the mean values of signalling factors and the number of apoptotic cells were statistically significant.

CONCLUSION

Specific to interradicular septum osteoblasts and osteoclasts factors include osteoprotegerin, osteocalcin, matrix metalloproteinase 8, matrix metallproteniase 9, and nuclear factors kappa B. The mean expression levels of these proteins and the mean TUNEL staining statistically significantly decreased with age. This is preliminary study and more patients are necessary for more precise statistical analysis in the future.

Rat model for studying tissue changes induced by the mechanical environment surrounding loaded titanium implants

PURPOSE

This study presents a new rat oral implant model for assessing histologic changes in the mechanical environment surrounding loaded and unloaded dental implants.

MATERIALS AND METHODS

The maxillary left first molar from retired breeder rats was extracted, and the site was allowed to heal for 1 month. A titanium miniscrew implant was then placed into the site and allowed to heal for 21 days. The mandibular left first molars in one group of rats were extracted to create an unloaded condition; in a second group of rats the mandibular left first molars were left in occlusion with the opposing screw head to simulate loading. Radiographs were taken on the day of placement and again at 7 days, 14 days, and 21 days after placement and were used to estimate the bone-implant contact ratio. The rats were sacrificed after 21 days. Peri-implant tissue samples from day 21 were processed for histology and immunohistochemistry with antibodies to osteocalcin and matrix metalloproteinase 13 (MMP-13). Two-dimensional finite element models were created from images of the histologic sections and immunohistochemical samples to observe tissue changes.

RESULTS

Areas of high shear stress adjacent to the helical threads of loaded implants were associated with osteocalcin localization and bone formation but only minimal localization of MMP-13. Bone adjacent to unloaded implants showed fibrous tissue and extensive MMP-13 localization surrounding the apical two-thirds of each implant. These results agree with estimated bone-implant contact ratios, which showed a steady decrease in contact ratio for the unloaded implant group but a significantly higher contact ratio in the loaded group between 14 and 21 days.

CONCLUSION

The rat oral implant model is useful for studies of the mechanical and physiologic environment affecting osseointegration in loaded and unloaded implants.

[Relationship between the expression of matrix metalloproteinase-13 protein and other biomarkers, prognosis in invasive breast cancer]

OBJECTIVE

The study was designed to investigate the expression patterns of metalloproteinase (MMP)-13 protein in invasive breast carcinoma and to determine the clinicopathological and prognostic values of its various localization and relation to the tumor phenotypes.

METHODS

Immunohistochemistry was performed on paraffin-embedded tissue array from 263 invasive breast carcinomas to investigate the protein expressions of MMP-13, estrogen receptor, progesterone receptor, HER2, MMP-2, MMP-9 and tissue inhibitor of matrix metalloproteinases (TIMP)-1, TIMP-2.

RESULTS

MMP-13 protein was detected in the cytoplasm of carcinoma cells and peritumoral fibroblasts. High level expression of MMP-13 protein in tumor cells was associated with more lymph node involvement and higher tumor grade (both P < 0.01), and positively correlated with HER2 (P = 0.015) and TIMP-1 protein (P < 0.01) expression in carcinoma cells. Moreover, high expression of MMP-13 was associated with shortened overall survival for the entire patient population and the patient group with positive lymph node. Tumor cell derived MMP-13 had different impact on patients with different HER2 status. Peritumoral fibroblasts derived MMP-13 protein, although correlated with tumor cell derived MMP-13 and associated with lymph node stage and HER2 expression, was found having less prognostic impact. Univariate survival analysis showed that the tumor size, grade, lymph node status, PR status, HER2 expression, tumors TIMP-1 and MMP-13 expression were prognostic factors. However, multivariate survival analysis showed that only tumor size, lymph node status, HER2 expression, tumors TIMP-1 and MMP-13 were independent prognostic factors.

CONCLUSION

MMP-13 protein expressed by tumor cells correlates with the invasion and metastasis of breast carcinoma, and therefore, may serve as a poor prognostic marker for the patient.

Altered gene expression levels of matrix metalloproteinases and their inhibitors in periodontitis-affected gingival tissue

BACKGROUND

The balance between the degradation and synthesis of extracellular matrix determines periodontal attachment levels and alveolar bone matrix concentration in periodontal diseases. Matrix metalloproteinases (MMPs) are known to degrade periodontal ligamental attachment and bone matrix proteins. The purpose of this study was to examine the effect of different expression levels of MMPs and their inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), in periodontitis.

METHODS

Sixteen inflamed gingival tissue samples from subjects with generalized chronic periodontitis and 14 control tissue samples from systemically and periodontally healthy subjects were evaluated. The total RNA was extracted, and the transcript levels for MMP-1, -3, -9, and -13 and TIMP-1, -2, -3, and -4 relative to beta-actin were determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

Gene transcript levels for MMP-1 and TIMP-4 were significantly higher in periodontitis-affected gingival tissues (P <0.05). MMP-3, -9, and -13 and TIMP-1 mRNAs also were elevated in periodontitis; however, the difference was not statistically significant. TIMP-2 and -3 mRNA levels were similar in healthy and diseased gingivae. The ratios of MMP-1/TIMP-2 (P <0.01), MMP-3/TIMP-2 (P <0.05), MMP-9/TIMP-2 (P <0.05), and MMP-1/TIMP-3 (P <0.01) from periodontitis lesions were significantly higher than those in the control tissues.

CONCLUSIONS

Upregulated MMP expression and an increased MMP/TIMP ratio indicate that a potential imbalance between degradation and synthesis of extracellular matrix persists in periodontitis-affected gingival tissues. This process may be responsible for increased tissue breakdown in periodontitis.

MMP-13 and TIMP-1 determinations in progressive chronic periodontitis

Matrix metalloproteinase (MMP)-13 is a collagenase involved in extracellular matrix degradation either by its direct degradative effects or by processing bioactive substrates. The aim of this study was to determine the levels of MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 in gingival crevicular fluid (GCF) and gingival biopsies obtained from active and inactive sites during chronic periodontitis progression.

MATERIALS AND METHODS

This was a longitudinal study in which chronic periodontitis patients with moderate to severe disease were included and followed until they developed progression determined by the tolerance method. GCF samples were obtained from periodontitis, active, inactive and healthy sites and additional gingival biopsies were taken from active and inactive sites. MMP-13 and TIMP-1 determinations were carried out by immunodot blots and immunowestern blots.

RESULTS

In progressive periodontitis, MMP-13 and TIMP-1 remained unchanged between active and inactive sites, but as the TIMP-1 relative levels increased together with MMP-13 elevation in inactive samples, an inverse correlation was observed in active sites. Besides, MMP-13 was undetectable in healthy controls.

CONCLUSION

Chronic periodontitis is characterized by increased MMP-13 expression. During disease progression, active sites tended to decrease TIMP-1 levels in association with MMP-13 elevation.

Pulsed low intensity ultrasound enhances mineralisation in preosteoblast cells

Pulsed low intensity ultrasound has been shown to be highly efficacious in the treatment of nonunion fractures and in the acceleration of fresh fracture healing. MC3T3-E1 subclone 14 cells were cultured for up to 25 days either with or without a daily treatment with low intensity pulsed ultrasound. It was determined that, on day 10 there was a dramatic increase in alkaline phosphatase and MMP-13 mRNA levels detected in ultrasound-treated cultures compared with untreated controls. The activity of alkaline phosphatase was significantly increased at days 6, 8 and 10. On day 10, the amount of mineralisation within cultures, assessed using alizarin red staining, was significantly increased in ultrasound-treated cultures compared with untreated controls. These results suggest that one of the mechanisms that low intensity pulsed ultrasound has on fracture repair is to enhance the process of endochondral ossification where the soft callus is converted to mineralised hard callus.

In situ localization of gelatinolytic activity during development and resorption of Meckel's cartilage in mice

Degradation of Meckel's cartilage in the middle portion is accompanied by hypertrophy and death of chondrocytes, calcification of the cartilaginous matrix, and chondroclastic resorption. We hypothesize that the gelatinolytic activity of matrix metalloproteinases (MMPs) largely contributes to the degradation of extracellular matrix (ECM) in the process. The activity in Meckel's cartilage of mouse mandibular arches at embryonic days 14-16 (E14-E16) was examined by a combination of in situ zymography (ISZ), using quenched fluorescent dye-labeled gelatin as a substrate, with CTT (a selective inhibitor of MMP-2 and -9) or with EDTA (a general MMP inhibitor). On E14 and E15, ISZ showed fluorescence in the perichondrium, in the intercellular septa between chondrocytes, and in the nucleus of chondrocytes. CTT attenuated fluorescence, and EDTA eliminated it. On E16, calcified cartilaginous matrix showed intense fluorescence, and dot-like fluorescence was observed in as-yet uncalcified intercellular septa, even after CTT treatment. EDTA inhibited fluorescence, but unexpectedly intense fluorescence was found in the cytoplasm of hypertrophic chondrocytes facing the resorption front. MMP-2, -9, and -13 immunoreactivity was detected in the perichondrium and chondrocytes of Meckel's cartilage. These findings suggest that MMPs and other proteinases capable of degrading gelatin play an integral role in the development, calcification, and resorption of Meckel's cartilage through ECM reconstitution.

Scar-associated macrophages are a major source of hepatic matrix metalloproteinase-13 and facilitate the resolution of murine hepatic fibrosis

Both the identity and source of the rodent collagenase(s) that mediates matrix remodeling in liver fibrosis remain elusive. We have recently demonstrated an unequivocal role for scar-associated macrophages (SAMs) in the spontaneous resolution of liver fibrosis and sought to determine whether SAMs are the source of matrix metalloproteinase (MMP) 13 (collagenase 3), considered to be the primary interstitial collagenase in rodents. In this study, we demonstrate an association between MMP13 expression and the presence of SAMs in the regression of experimental liver fibrosis. mmp13 gene expression was restricted to regions of fibrosis that were rich in SAMs. Both MMP13 mRNA and protein colocalized to large phagocytes within and directly apposed to hepatic scars. Using the CD11b-DTR-transgenic mouse to deplete SAMs in a model of chronic CCl(4) injury, we found that SAM depletion resulted in a 5-fold reduction in mmp13 message (p = 0.005). Furthermore, resolution of CCl(4)-induced fibrosis was retarded in MMP13-deficient mice. Thus, SAMs selectively, during resolution of fibrosis induce and use the major collagenase MMP13 to mediate the resorption of interstitial matrix and successfully remodel the fibrotic liver.

Gas-related impact of pneumoperitoneum on systemic wound healing

INTRODUCTION

The aim of the present study was to investigate the gas-dependent effects of pneumoperitoneum on wound healing distant from the abdomen.

MATERIALS AND METHODS

Dorsal skin incisions were performed in 54 male Sprague-Dawley rats. A CO(2) or a helium pneumoperitoneum of 3 mmHg was maintained before, with an overall duration of 30 min (each n = 18). Rats in the control group received laparotomy only (n = 18). Animals were killed after 5 and 10 days. The infiltration of macrophages (CD 68), expression of matrix metalloproteinase 13 (MMP-13) and collagen I/III ratios were analysed in the dorsal skin wounds.

RESULTS

Both after 5 and 10 days, infiltration of macrophages and expression of MMP-13 were greatest after helium pneumoperitoneum. After 5 days, collagen I/III ratio was significantly increased in the helium group. After 10 days, collagen I/III ratio was lowest in the CO(2) group.

CONCLUSION

Our results suggest beneficial effects on systemic wound healing for helium pneumoperitoneum as compared to CO(2).

Age-dependent increase of discoidin domain receptor 2 and matrix metalloproteinase 13 expression in temporomandibular joint cartilage of type IX and type XI collagen-deficient mice

Our previous studies demonstrated that mutations in type IX and type XI collagens in mice caused osteoarthritis (OA)-like changes in knee and temporomandibular (TM) joints. We also found that the overexpression of matrix metalloproteinase 13 (Mmp-13) was probably due to the up-regulation of a collagen receptor, discoidin domain receptor 2 (Ddr2), which was responsible for knee cartilage degeneration in mutant mice. The objective of our study was to determine whether the expression of Mmp-3, Mmp-13 and Ddr2 was increased in OA-like TM joints in mutant mice using immunohistochemistry. We found that the staining for Ddr2, Mmp-13 and Mmp-derived type II collagen fragments in tissue sections from 6-month-old mice was increased in TM joints of the mutant mice. In contrast, we found no difference in the staining for Mmp-3 amongst the two mutant mice and their wild-type littermates. We conclude that, similar to previous observations in knee joints, the overexpression of Ddr2 and Mmp-13 may be responsible for the OA-like change in TM joints in mutant mice.

Gingival crevicular fluid matrix metalloproteinase-13 levels and molecular forms in various types of periodontal diseases

BACKGROUND

The purpose of this study was to evaluate the levels, molecular forms and activation degree of matrix metalloproteinase-13 (MMP-13) in the gingival crevicular fluid (GCF) of patients with periodontal diseases and to correlate these findings with periodontal clinical parameters.

METHODS

Sixty one subjects participated in this study as healthy (n = 18), gingivitis (n = 17), aggressive periodontitis (AgP; n = 15) and chronic periodontitis (CP; n = 11) groups. Clinical measurements and GCF samples were obtained from each subject. The molecular forms of MMP-13 in GCF samples were analyzed by Western immunoblotting method. Differences among the groups were assessed using non-parametric statistical analysis.

RESULTS

In the CP group, levels of 29-30 kDa fragment of MMP-13, total MMP-13, and activated form of MMP-13 were significantly higher than in the healthy, gingivitis and AgP groups. GCF levels of all molecular forms of MMP-13 in AgP group were similar to those of healthy and gingivitis groups. Total and activated MMP-13 levels were positively correlated with all clinical parameters. 29-30 kDa fragment levels of MMP-13 were also positively correlated with papillary bleeding index and plaque index.

CONCLUSION

These results indicate that elevated GCF MMP-13 levels may play an important role in the pathogenesis of CP. These data demonstrate, for the first time, pathologically activated and elevated MMP-13 in GCF.

Induction of tumour necrosis factor, interleukin-1beta and matrix metalloproteinases in pulmonary fibrosis of rats infected with Angiostrongylus cantonensis

In angiostrongyliasis, chronic parasite-induced granuloma formation can lead to tissue destruction and fibrosis. Here, the histomorphology of granulomatous fibrosis and proteinase production in the lungs of Angiostrongylus cantonensis-infected Sprague-Dawley rats were investigated. The relationship between metalloproteinases and granulomatous fibrosis was investigated following infection of each rat with 60 infective larvae. Granulomata and fibrosis were marked in the lungs of rats on day 180 post-inoculation. Reverse transcriptase polymerase chain reaction of lung mRNA showed an up-expression of proinflammatory cytokine including tumour necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta). According to Western blot analysis, matrix metalloproteinase-2 (MMP-2) proenzyme was presented in the lungs of uninfected and infected rats, and partial conversion of 72 kDa proenzyme to the 64 kDa active form occurred in infected rats. In addition, increased protein levels of MMP-9 and MMP-13 were detected in infected lungs, but were undetectable in controls. The results suggest that TNF-alpha, IL-1beta, MMP-2, -9, and -13 may be associated with the granulomatous fibrosis.