Dual role of enhancer of zeste homolog 2 in the regulation of ultraviolet radiation-induced matrix metalloproteinase-1 and type I procollagen expression in human dermal fibroblasts

Abnormalities in the extracellular matrix (ECM) caused by ultraviolet (UV) radiation are mediated by epigenetic mechanisms. Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that is implicated in inflammation, immune regulation, and senescence. However, its role in controlling UV-induced ECM alterations in the skin remains elusive. Here, we investigated the role of EZH2 in UV-induced expression of matrix metalloproteinase (MMP)-1 and type I procollagen. We found that UV induced EZH2 expression in human skin in vivo and in human dermal fibroblasts (HDFs). EZH2 knockdown reduced the expression and promoter activity of MMP-1 and increased those of type I procollagen, whereas EZH2 overexpression had the opposite effects. Mechanistically, EZH2 increased NF-κB activity, and p65 and p50 expression and promoter activity. Intriguingly, chromatin immunoprecipitation assays revealed that the EZH2/p65/p50 complex was recruited and bound to the MMP-1 promoter after UV irradiation, independent of its histone methyltransferase activity. In contrast, EZH2-induced DNA methyltransferase 1 (DNMT1) formed a complex with EZH2 and enhanced the enrichment of H3K27me3 on the COL1A2 promoter following UV irradiation. These findings indicate that EZH2 plays a dual role in regulating MMP-1 and type I procollagen expression and improve our understanding of how this epigenetic mechanism contributes to UV-induced skin responses and photoaging. This study shows that inhibiting EZH2 is a potential anti-aging strategy for preventing UV-induced skin aging by reducing MMP-1 expression and inducing type I procollagen expression.

Diagnosis of invasive non-functional pituitary adenomas using exosomal biomarkers

BACKGROUND AND AIMS

Incomplete surgical resection of invasive non-functional pituitary adenomas (NFPAs) produces a risk of the subsequent development of complications which will require treatment with powerful drugs and adjuvant radiotherapy.

MATERIALS AND METHODS

The degree of invasiveness of NFPA can be established using biomarkers to help clinicians choose appropriate treatment for these patients.

RESULTS

This research explored transcriptomic and proteomic variations of non-invasive and invasive NFPAs, other forms of pituitary adenomas and evaluated exosomal genetic markers associated with these diseases. Increased expression of matrix metalloproteinase-1 (MMP1) and its formation in exosomes (exo-MMP1) were correlated with the characteristic invasiveness of NFPAs. Changes in the expression of MMP1 in the exosome was synchronized with transduction of NFPA cells. Enrichment of MMP1 stimulated migration, growth and angiogenesis in tumors through the protease-activated receptor-1 signaling pathway in cells.

CONCLUSION

The results revealed that MMP1 activity has obligatory actions in promoting tumor invasion and angiogenesis, and that the exosome-mediated regulatory pathway for MMP1 may be a novel therapeutic target.

Protective effects of Quercus acuta Thunb. fruit extract against UVB-induced photoaging through ERK/AP-1 signaling modulation in human keratinocytes

Background

Quercus acuta Thunb. (Fagaceae) or Japanese evergreen oak is cultivated as an ornamental plant in South Korea, China, Japan, and Taiwan and used in traditional medicine. The acorn or fruit of Quercus acuta Thunb. (QAF) is the main ingredient of acorn jelly, a traditional food in Korea. Its leaf was recently shown to have potent xanthine oxidase inhibitory and anti-hyperuricemic activities; however, there have been no studies on the biological activity of QAF extracts. Solar ultraviolet light triggers photoaging of the skin, which increases the production of reactive oxygen species (ROS) and expression of matrix metalloproteinase (MMPs), and destroys collagen fibers, consequently inducing wrinkle formation. The aim of this study was to investigate the effect of water extracts of QAF against UVB-induced skin photoaging and to elucidate the underlying molecular mechanisms in human keratinocytes (HaCaT).

Methods

In this study, we used HPLC to identify the major active components of QAF water extracts. Anti-photoaging effects of QAF extracts were evaluated by analyzing ROS procollagen type I in UVB-irradiated HaCaT keratinocytes. Antiradical activity was determined using 2,2-diphenyl-1-picrylhydrazyl and 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assays. The expression of MMP-1 was tested by western blotting and ELISA kits. QAF effects on phosphorylation of the MAPK (p38, JNK, and ERK) pathway and transcription factor AP-1, which enhances the expression of MMPs, were analyzed by western blots.

Results

We identified two major active components in QAF water extracts, gallotannic acid and ellagic acid. The QAF aqueous extracts recovered UVB-induced cell toxicity and reduced oxidative stress by inhibiting intracellular ROS generation in HaCaT cells. QAF rescued UVB-induced collagen degradation by suppressing MMP-1 expression. The anti-photoaging activities of QAF were associated with the inhibition of UVB-induced phosphorylation of extracellular signal-regulated kinase (ERK) and activator protein 1 (AP-1). Our findings indicated that QAF prevents UVB-induced skin damage due to collagen degradation and MMP-1 activation via inactivation of the ERK/AP-1 signaling pathway. Overall, this study strongly suggests that QAF exerts anti-skin-aging effects and is a potential natural biomaterial that inhibits UVB-induced photoaging.

Conclusion

These results show that QAF water extract effectively prevents skin photoaging by enhancing collagen deposition and inhibiting MMP-1 via the ERK/AP-1 signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03473-1.

The Effect of MMP-1 on Wound Healing and Scar Formation

BACKGROUND

In this study, we investigated the effect of matrix metalloproteinase-1 (MMP-1) on wound healing on skin in a model produced in rats.

METHODS

Sixteen Sprague-Dawley male rats were included in the study. The four full-thickness skin wound was created on the dorsal area of each rat with 4.4 mm punch. The rats were randomly divided into two groups. MMP-1 and saline were administered intraperitoneally once daily for 7 days. The biopsies were taken from the separate wounds on the 4th, 7th, 14th and 21st days of the experiment. The lymphocytic response, vascular proliferation, fibroblast proliferation, epithelial hyperplasia, foreign body reaction, ulcer formation, acute inflammation, keloid scar formation and hypertrophic scar formation were compared in each group in histopathologically.

RESULTS

In our study, epithelial hyperplasia on 14th day was significantly higher in the MMP-1 group compared to the control group (p < 0.05). The lymphocytic response on 4th and 21th days, the vascular proliferation on 4th day, the fibroblast proliferation on 4th and 7th days, the acute inflammation on 4th day and the hypertrophic scar formation on 7th, 14th, 21st days were significantly lower in the MMP-1 group compared to the control group (p < 0.05). No statistically significant difference was found in comparison with other parameters (p > 0.05).

CONCLUSIONS

MMP-1 improves the wound-healing process of skin with higher epithelial hyperplasia and reduces scar formation in the animal model. Therefore, MMP-1 can potentially be used as an effective anti-fibrogenic agent for preventing or treating the hypertrophic scar.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A synergy between the catalytic and structural Zn(II) ions and the enzyme and substrate dynamics underlies the structure-function relationships of matrix metalloproteinase collagenolysis

Matrix metalloproteinases (MMPs) are Zn(II) dependent endopeptidases involved in the degradation of collagen. Unbalanced collagen breakdown results in numerous pathological conditions, including cardiovascular and neurodegenerative diseases and tumor growth and invasion. Matrix metalloproteinase-1 (MMP-1) is a member of the MMPs family. The enzyme contains catalytic and structural Zn(II) ions. Despite many studies on the enzyme, there is little known about the synergy between the two Zn(II) metal ions and the enzyme and substrate dynamics in MMP-1 structure-function relationships. We performed a computational study of the MMP-1•triple-helical peptide (THP) enzyme•substrate complex to provide this missing insight. Our results revealed Zn(II) ions' importance in modulating the long-range correlated motions in the MMP-1•THP complex. Overall, our results reveal the importance of the catalytic Zn(II) and the role of the structural Zn(II) ion in preserving the integrity of the enzyme active site and the overall enzyme-substrate complex synergy with the dynamics of the enzyme and the substrate. Notably, both Zn(II) sites participate in diverse networks of long-range correlated motions that involve the CAT and HPX domains and the THP substrate, thus exercising a complex role in the stability and functionality of the MMP-1•THP complex. Both the Zn(II) ions have a distinct impact on the structural stability and dynamics of the MMP-1•THP complex. The study shifts the paradigm from the "local role" of the Zn(II) ions with knowledge about their essential role in the long-range dynamics and stability of the overall enzyme•substrate (ES) complex.

[Study of cytokines in peripheral blood and lung of rats exposed to hard metal dust]

Objective: To study the dynamic changes of cytokines in bronchoalveolar lavage fluid (BALF) and serum of hard metal lung disease (HMLDR) rats. Methods: In March 2019, the rats were randomly divided into 6 groups, each group included 8 rats: control (C) group include 3 groups, hard metal (HM) group include 3 groups. 10 mg HM were administered in HM group by using the pulmonary endotracheal tube. After 4, 8 and 12 week, the BALF and serum were collected for the enzyme-linked immunosorbent assay (ELISA) of matrix metalloproteinase-1 (MMP-1) , tissue inhibitor of metalloproteinase-1 (TIMP-1) and tumor necrosis factor-alpha (TNF-α) . Results: There was no abnormality in behavior, diet and fur of rats in C and HM group at each exposure time. There was no significant difference in body weight between the two groups of rats (P>0.05) . Compared with the C group, the expression of MMP-1 in BALF of rats in HM group were significantly higher in all stages (4, 8 and 12 weeks after exposure) (P<0.05) , the expression of TIMP-1 in BALF of rats in HM group were significantly higher in 8 and 12 weeks after exposure (P<0.05) . However, there was no significant difference in serum MMP-1 and TIMP-1 levels between the two groups in each stage (P>0.05) . There was no significant difference in TNF-α. level in BALF and serum between C and HM group in all stages (P>0.05) . Conclusion: Expression of MMP-1 and TIMP-1 in BALF have reference value in the HMLD auxiliary diagnosis.

Effect of UVA1 on hypertrophic scarring in the rabbit ear model

Hypertrophic scars (HTSs) are common and cause functional and psychological morbidity. UVA1 (340-400 nm) phototherapy has been previously shown to be effective in the treatment of localized scleroderma, systemic sclerosis, and POEMS syndrome with minimal side effects, all of which are presented as collagen fibrils hyperplasia that is common with scarring in skin histology. In the present study, we aimed to investigate the impact of UVA1 on the protein expression of TGF-β signal pathway and myofibroblasts in a rabbit model of cutaneous scarring. Full-thickness skin wounds (2 cm × 5 cm in diameter) were made in New Zealand white rabbits to establish the hypertrophic scarring model. New Zealand white rabbits were divided into two treatment groups (n=30 wounds per group with an equal number of controls): medium-dose of UVA1 phototherapy group: 60 J/cm2; high-dose of UVA1 phototherapy group: 110 J/cm2. Left ears were used for treatment and the right ones were used for control. Treatment was administered five times weekly for 6 weeks. Treated and untreated control wounds were harvested at various time points and examined by histologic examination, immunohistochemical assessment, and ultrastructural evaluation. The results showed that UVA1 phototherapy caused a significant reduction in dermal thickness by histological features, whereas the scar index was descended significantly in both medium- and high-dose UVA1 groups compared with the control group. Examination of immunohistochemistry also revealed a marked suppression of tissue growth factor-β (TGF-β) (both medium- and high-dose), α smooth muscle actin (α-SMA) (only high-dose), and tissue inhibitor of metalloproteinase 1 (TIMP-1) (only high-dose), and apparent increase in matrix metalloproteinases (MMP-1) (both medium- and high-dose) compared with the control. The ultrastructural evaluation showed the collagen fibers' diameter had shrunk, and that fibroblastic cytoplasm was not affluent and in a quiescent stage. These findings of the present study suggested that administration of UVA1 irradiation is effective to improve the experimental HTS model and raises a possibility of the therapeutic approach of UVA1 in the scar. Although not directly examined in the present study, MMP inhibition is hypothesized to be responsible for this effect. However, early UVA1 treatment could not prevent the formation of scar model.

Matrix metalloproteinase-1 decorated polymersomes, a surface-active extracellular matrix therapeutic, potentiates collagen degradation and attenuates early liver fibrosis

Liver fibrosis affects millions of people worldwide and is rising vastly over the past decades. With no viable therapies available, liver transplantation is the only curative treatment for advanced diseased patients. Excessive accumulation of aberrant extracellular matrix (ECM) proteins, mostly collagens, produced by activated hepatic stellate cells (HSCs), is a hallmark of liver fibrosis. Several studies have suggested an inverse correlation between collagen-I degrading matrix metalloproteinase-1 (MMP-1) serum levels and liver fibrosis progression highlighting reduced MMP-1 levels are associated with poor disease prognosis in patients with liver fibrosis. We hypothesized that delivery of MMP-1 might potentiate collagen degradation and attenuate fibrosis development. In this study, we report a novel approach for the delivery of MMP-1 using MMP-1 decorated polymersomes (MMPsomes), as a surface-active vesicle-based ECM therapeutic, for the treatment of liver fibrosis. The storage-stable and enzymatically active MMPsomes were fabricated by a post-loading of Psomes with MMP-1. MMPsomes were extensively characterized for the physicochemical properties, MMP-1 surface localization, stability, enzymatic activity, and biological effects. Dose-dependent effects of MMP-1, and effects of MMPsomes versus MMP-1, empty polymersomes (Psomes) and MMP-1 + Psomes on gene and protein expression of collagen-I, MMP-1/TIMP-1 ratio, migration and cell viability were examined in TGFβ-activated human HSCs. Finally, the therapeutic effects of MMPsomes, compared to MMP-1, were evaluated in vivo in carbon-tetrachloride (CCl₄)-induced early liver fibrosis mouse model. MMPsomes exhibited favorable physicochemical properties, MMP-1 surface localization and improved therapeutic efficacy in TGFβ-activated human HSCs in vitro. In CCl₄-induced early liver fibrosis mouse model, MMPsomes inhibited intra-hepatic collagen-I (ECM marker, indicating early liver fibrosis) and F4/80 (marker for macrophages, indicating liver inflammation) expression. In conclusion, our results demonstrate an innovative approach of MMP-1 delivery, using surface-decorated MMPsomes, for alleviating liver fibrosis.

Formation of lamellar body-like structure may be an initiator of didecyldimethylammonium chloride-induced toxic response

Due to the pandemic of coronavirus disease 2019, the use of disinfectants is rapidly increasing worldwide. Didecyldimethylammonium chloride (DDAC) is an EPA-registered disinfectant, it was also a component in humidifier disinfectants that had caused idiopathic pulmonary diseases in Korea. In this study, we identified the possible pulmonary toxic response and mechanism using human bronchial epithelial (BEAS-2B) cells and mice. First, cell viability decreased sharply at a 4 μg/mL of concentration. The volume of intracellular organelles and the ROS level reduced, leading to the formation of apoptotic bodies and an increase of the LDH release. Secretion of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and matrix metalloproteinase-1 also significantly increased. More importantly, lamellar body-like structures were formed in both the cells and mice exposed to DDAC, and the expression of both the indicator proteins for lamellar body (ABCA3 and Rab11a) and surfactant proteins (A, B, and D) was clearly enhanced. In addition, chronic fibrotic pulmonary lesions were notably observed in mice instilled twice (weekly) with DDAC (500 μg), ultimately resulting in death. Taken together, we suggest that disruption of pulmonary surfactant homeostasis may contribute to DDAC-induced cell death and subsequent pathophysiology and that the formation of lamellar body-like structures may play a role as the trigger. In addition, we propose that the cause of sudden death of mice exposed to DDAC should be clearly elucidated for the safe application of DDAC.

Immuohistochemical score of matrix metalloproteinase-1 may indicate the severity of symptomatic cervical and lumbar disc degeneration

BACKGROUND CONTEXT

Intervertebral disc (IVD) degeneration is related to numerous risk factors, including obesity. Leptin, one of the commonly measured adipokines, is proven to play an important role in the pathogenesis of IVD degeneration. In the context of IVD degeneration, matrix metalloproteinase-1 (MMP-1), which is upregulated and activated by leptin, is the most abundant catabolic enzyme. It remains unclear which of the factors mentioned above is most strongly associated with IVD degeneration.

PURPOSE

To investigate the influence of MMP-1 in IVD degeneration, we determined the strength of different predictors, including age, sex, magnetic resonance imaging (MRI), Modic changes (MCs), body mass index (BMI), leptin, and MMP-1. This was achieved by assessing the correlation among these factors and histologic degeneration score (HDS).

STUDY DESIGN

This study included 89 patients undergoing cervical discectomy for disc herniation, 93 who underwent lumbar discectomy, and 90 control subjects. Herniated disc tissue and plasma were used after the study was approved by the Human Ethics Review Committee at the authors' institution.

METHODS

Hematoxylin and eosin (H&E), Alcian blue-PAS and immunohistochemical (IHC) staining were performed to measure the expression levels of leptin and MMP-1. Circulating plasma levels of leptin and MMP-1 were measured using an enzyme-linked immunosorbent assay. To assess the correlation with HDS, measurements of age, sex, BMI, MRI scale, MCs scale, leptin/MMP-1 plasma concentration, and leptin/MMP-1 IHC expression were analyzed.

RESULTS

Patients with cervical or lumbar discectomy had significantly higher BMI than controls. Significantly more men than women were involved in the lumbar patients as compared with the cervical patients and the control subjects. After adjustment for age and sex, plasma leptin and leptin IHC score correlated significantly with BMI in patients with cervical or lumbar discectomy. Age, sex, MRI scale, MCs scale, and leptin/MMP-1 plasma concentration were not positively correlated with HDS. HDS was significantly associated with BMI, leptin IHC score, and MMP-1 IHC score. After a stepwise-multiple linear regression analysis to evaluate the strength of the correlations between HDS and various factors, only the MMP-1 IHC score demonstrated an independent association with HDS in patients with degeneration of the cervical or lumbar disc.

CONCLUSIONS

MMP-1 IHC score is an independent predictor of the severity of cervical or lumbar IVD degeneration.

CLINICAL SIGNIFICANCE

MMP-1 IHC score may be used as an indicator of IVD degeneration.

Association of polymorphisms in IL-8, MMP-1 and MMP-13 with the risk and prognosis of oral and oropharyngeal squamous cell carcinoma

OBJECTIVE

This study investigated the risk and prognostic value of single nucleotide polymorphisms (SNP) inIL-8, MMP-1 and MMP-13 in oral and oropharyngeal squamous cell carcinomas (SCCs).

DESIGN

SNPs rs2227532 and rs4073 inIL-8, rs2071230 and rs470558 in MMP-1, and rs2252070 in MMP-13 were genotyped in 125 oral and oropharyngeal SCC patients and 130 healthy controls, using TaqMan allelic discrimination assays. Multiple logistic regression models were used to explore the association between SNPs and cancer development, as well as SNP-SNP interaction and gene-environmental factor (GxE) interaction. Univariate and multivariate methods were applied for survival analyses.

RESULTS

With exception of rs2227532, all the SNPs were in Hardy-Weinberg equilibrium in the control. No associations between rs4073 in IL-8 and rs2071230 and rs470558 in MMP-1 were observed, but rs2252070 in MMP-13, in the dominant model, was associated in a protective manner to oral and oropharyngeal SCC (OR: 0.20, 95% CI: 0.06-0.71, p = 0.007). All SNPs interact significantly with cigarette smoking and alcohol consumption on susceptibility to oral and oropharyngeal SCC, but they showed no influence on survival of the patients.

CONCLUSIONS

Our results show that rs2252070 inMMP-13 may confer protection effect against oral and oropharyngeal SCC. In addition, the combined effects of IL-8 (rs4073), MMP-1 (rs2071230 and rs470558) and MMP-13 (rs2252070) with environmental carcinogens, such as tobacco and alcohol, are related to increased risk for oral and oropharyngeal SCC development.

Esculetin Prevents the Induction of Matrix Metalloproteinase-1 by Hydrogen Peroxide in Skin Keratinocytes

Background

Reactive oxygen species (ROS) are involved in various cellular diseases. Excessive ROS can cause intracellular oxidative stress, resulting in a calcium imbalance and even aging. In this study, we evaluated the protective effect of esculetin on oxidative stress-induced aging in human HaCaT keratinocytes.

Methods

Human keratinocytes were pretreated with esculetin for 30 minutes and treated with H₂O₂. Then, the protective effects on oxidative stress-induced matrix metalloproteinase (MMP)-1 were detected by Flou-4-AM staining, reverse transcription-PCR, Western blotting, and quantitative fluorescence assay.

Results

Esculetin prevented H₂O₂-induced aging by inhibiting MMP-1 mRNA, protein, and activity levels. In addition, esculetin decreased abnormal levels of phospho-MEK1, phospho-ERK1/2, phospho-SEK1, phospho-JNK1/2, c-Fos, and phospho-c-Jun and inhibited activator protein 1 binding activity.

Conclusions

Esculetin prevented excessive levels of intracellular calcium and reduced the expression levels of aging-related proteins.

Biomarker-based phenotyping of myocardial fibrosis identifies patients with heart failure with preserved ejection fraction resistant to the beneficial effects of spironolactone: results from the Aldo-DHF trial

BACKGROUND

Myocardial fibrosis is characterized by excessive cross-linking and deposition of collagen type I and is involved in left ventricular stiffening and left ventricular diastolic dysfunction (LVDD). We investigated whether the effect of spironolactone on LVDD in patients with heart failure with preserved ejection fraction (HFpEF) depends on its effects on collagen cross-linking and/or deposition.

METHODS AND RESULTS

We investigated 381 HFpEF patients from the multicentre, randomized, placebo-controlled Aldo-DHF trial with measures of the E:e' ratio. The ratio of serum carboxy-terminal telopeptide of collagen type I to serum matrix metalloproteinase-1 (CITP:MMP-1, an inverse index of myocardial collagen cross-linking) and serum carboxy-terminal propeptide of procollagen type I (PICP, a direct index of myocardial collagen deposition) were determined at baseline and after 1-year treatment with spironolactone 25 mg once daily or placebo. Patients were classified by CITP:MMP-1 and PICP tertiles at baseline. While CITP:MMP-1 tertiles at baseline interacted (P < 0.05) with spironolactone effect on E:e', PICP tertiles did not. In fact, while spironolactone treatment did not modify E:e' in patients with lower CITP:MMP-1 levels, this ratio was significantly reduced in the remaining spironolactone-treated patients. In addition, PICP was unchanged in patients with lower CITP:MMP-1 levels but was reduced in the remaining spironolactone-treated patients.

CONCLUSIONS

A biochemical phenotype of high collagen cross-linking identifies HFpEF patients resistant to the beneficial effects of spironolactone on LVDD. It is suggested that excessive collagen cross-linking, which stabilizes collagen type I fibres, diminishes the ability of spironolactone to reduce collagen deposition in these patients.

Punicalagin and (-)-Epigallocatechin-3-Gallate Rescue Cell Viability and Attenuate Inflammatory Responses of Human Epidermal Keratinocytes Exposed to Airborne Particulate Matter PM10

BACKGROUND/AIMS

Airborne particulate matter with a diameter of < 10 µm (PM10) causes oxidative damage, inflammation, and premature skin aging. In this study, we evaluated whether polyphenolic antioxidants attenuate the inflammatory responses of PM10-exposed keratinocytes.

METHODS

Primary human epidermal keratinocytes were exposed in vitro to PM10 in the absence or presence of punicalagin and (-)-epigallocatechin-3-gallate (EGCG), which are the major polyphenolic antioxidants found in pomegranate and green tea, respectively. Assays were performed to determine cell viability, production of reactive oxygen species (ROS), and expression of NADPH oxidases (NOX), proinflammatory cytokines, and matrix metalloproteinase (MMP)-1.

RESULTS

PM10 decreased cell viability and increased ROS production in a dose-dependent manner. It also increased the expression levels of NOX-1, NOX-2, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-8, and MMP-1. Punicalagin was not cytotoxic up to 300 μM, and (-)-EGCG was cytotoxic above 30 μM, respectively. Further, punicalagin (3-30 μM) and EGCG (3-10 μM) rescued the viability of PM10-exposed cells. They also attenuated ROS production and the expression of NOX-1, NOX-2, TNF-α, IL-1β, IL-6, IL-8, and MMP-1 stimulated by PM10.

CONCLUSIONS

This study demonstrates that polyphenolic antioxidants, such as punicalagin and (-)-EGCG, rescue keratinocyte viability and attenuate the inflammatory responses of these cells due to airborne particles.

Preventive effect of Ephedra sinica extract on UVB-induced COX-2 and MMP-1 expression

Ultraviolet B (UVB)-induced cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-1 are representative markers for skin inflammation and photoaging, respectively. To evaluate compounds that may counteract the effects of UVB-induced skin damage, we developed an immortalized human keratinocyte (HaCaT) cell line with an MMP-1 reporter construct. Among the 30 botanical extracts screened, we selected Ephedra sinica extract (ESE) as a promising candidate and confirmed that ESE significantly suppresses UVB-induced COX-2 and MMP-1 expression in HaCaT cells. Treatment with ESE also potently suppressed UVB-induced ERK1/2 phosphorylation, as well as UVB-induced MEK1/2 and Raf phosphorylation in HaCaT cells. These findings suggest that our MMP-1 reporter system can be used to evaluate compounds with anti-inflammatory and anti-photoaging effects. We also report that ESE has potent suppressive effects against COX-2 and MMP-1 expression, which occurs via downregulation of Raf/MEK1/2/ERK1/2 phosphorylation.

Involvement of PI3K and MMP1 in PDGF-induced Migration of Human Adipose-derived Stem Cells

Human adult stem cells have widely been examined for their clinical application including their wound healing effect in vivo. To function as therapeutic cells, however, cells must represent the ability of directed migration in response to signals. This study aimed to investigate the mechanism of platelet-derived growth factor (PDGF)-induced migration of the human abdominal adipose-derived stem cells (hADSCs) in vitro. A general matrix metalloproteinase (MMP) inhibitor or a MMP2 inhibitor significantly inhibited the PDGF-induced migration. PDGF treatment exhibited greater mRNA level and denser protein level of MMP1. The conditioned medium of PDGF-treated cells showed a caseinolytic activity of MMP1. Transfection of cells with siRNA against MMP1 significantly inhibited MMP1 expression, its caseinolytic activity, and cell migration following PDGF treatment. Phosphatidylinositol 3-kinase (PI3K) inhibitor reduced the migration by about 50% without affecting ERK and MLC proteins. Rho-associated protein kinase inhibitor mostly abolished the migration and MLC proteins. The results suggest that PDGF might signal hADSCs through PI3K, and MMP1 activity could play an important role in this PDGF-induced migration in vitro.

Investigation of MMP-1 genetic polymorphisms and protein expression and their effects on the risk of Kashin-Beck disease in the northwest Chinese Han population

BACKGROUND

The etiology of Kashin-Beck disease (KBD), an endemic osteochondropathy, is largely unknown. Matrix metalloproteinase-1 (MMP-1) plays a central role in the initiation and progression of cartilage destruction; however, no study has reported on the relationship between KBD and MMP-1. This study was to investigate the role of MMP-1 in the pathogenesis and progression of KBD.

METHODS

Single nucleotide polymorphism (SNP) genotyping was conducted for 274 KBD cases and 248 healthy controls using the Sequenom MassARRAY system. Additionally, the expression of MMP-1 in the knee articular cartilage of 22 KBD patients and 21 controls was analyzed by immunohistochemistry, and the concentration of MMP-1 in their joint fluid was also measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results showed that two SNPs (rs470221 and rs1144396) had a weak association with increased KBD risk; however, the significance of these results did not survive Bonferroni's correction. Moreover, the percentages of cells expressing MMP-1 in each layer of cartilage were significantly higher in the KBD group than in the controls (F = 11.41-28.31, P = 0.002-0.000). The concentration of MMP-1 in KBD joint fluid was significantly higher than that in the controls (t = 9.83, P < 0.0001).

CONCLUSIONS

The increased expression of MMP-1 has a potential effect on the risk of KBD in the northwest Chinese Han population. However, six selected SNPs in the MMP-1 gene might not be useful as significant markers for predicting KBD susceptibility in Chinese Han population. Therefore, future studies in the association of MMP-1 with KBD should focus on other candidate SNPs.

Anti-wrinkle effects of Seungma-Galgeun-Tang as evidenced by the inhibition of matrix metalloproteinase-I production and the promotion of type-1 procollagen synthesis

Background

Seungma-Galgeun-Tang (SMGGT), a traditional herbal medicinal formula, has been used to treat various skin problems such as inflammation and rashes in Korean traditional medicine. In order to clarify the scientific evidence for the biological efficacy of SMGGT on the prevention of skin aging and in particular wrinkle formation, molecular anti-wrinkle parameters were evaluated in cultured human dermal fibroblasts.

Methods

Standard SMGGT was prepared from KFDA-certified herbal medicines and the chemical fingerprint of SMGGT was verified by HPLC-ESI-MS to insure the quality of SMGGT. To evaluate the inhibitory effects of SMGGT on the synthesis of matrix metalloproteinase-1 (MMP-1) and type-1 procollagen, the content of MMP-1 and type-1 procollagen synthesizing enzymes in cultured human dermal fibroblasts were measured using an ELISA kit and Western Blot, respectively.

Results

The treatment of SMGGT water extract significantly inhibited the production of MMP-1 and promoted type-1 procollagen synthesis concentration dependently.

Conclusions

These results suggest that SMGGT has the potential to prevent wrinkle formation by down-regulating MMP-1 and up-regulating type-1 procollagen in human dermal fibroblasts.

Effect of siRNA-mediated down-regulation of receptor for advanced glycation end products on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in rat hepatic stellate cells and hepatic fibrosis

AIM: To investigate the effect of small interfering RNA (siRNA)-mediated down-regulation of receptor for advanced glycation end products (RAGE) on the expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in primary rat hepatic stellate cells (HSCs) and hepatic fibrosis (HF).

METHODS: In in vitro experiment, primary rat HSCs were cultured and isolated. The pAKD-GR126 vector carrying siRNA targeting RAGE was constructed and transfected to primary rat HSCs. Blank cells and cells transfected with unspecific siRNA vector pAKD-NC were used as controls. In in vivo experiment, liver fibrosis was induced in SD rats with CCl₄. pAKD-GR126 was transfected to liver fibrosis rats at different doses via the tail vein. A blank group, a liver fibrosis model group and an unspecific siRNA vector pAKD-NC-transfected group were used as controls. Real-time PCR and Western blot were used to detect the expression of RAGE, MMP-1 and TIMP-1. The histological changes of the liver were observed by HE and Masson staining methods.

RESULTS: The mRNA and protein expression of RAGE and TIMP-1 in pAKD-GR126-transfected primary HSCs was significantly lower than that in the blank group and unspecific siRNA vector pAKD-NC-transfected group (P < 0.05 for all). However, the level of MMP-1 in pAKD-GR126-transfected primary HSCs was significantly higher than that in the blank group and pAKD-NC-transfected group (P < 0.05 for all). In vivo, the mRNA and protein expression of RAGE and TIMP-1 was significantly lower and that of MMP-1 was significantly higher in the low-, medium-, and high-dose RAGE siRNA groups than in the liver fibrosis model group (P < 0.05 for all). Compared with the liver fibrosis model group, liver fibrosis was significantly milder in the low-, medium-, and high-dose RAGE siRNA groups, especially the high-dose group.

CONCLUSION: RAGE specific siRNA could decrease the expression of RAGE and TIMP-1, increase the expression of MMP-1 in primary rat HSCs and HF rats, and reduce the degree of rat hepatic fibrosis.

p-Coumaric Acid Attenuates UVB-Induced Release of Stratifin from Keratinocytes and Indirectly Regulates Matrix Metalloproteinase 1 Release from Fibroblasts

Ultraviolet (UV) radiation-induced loss of dermal extracellular matrix is associated with skin photoaging. Recent studies demonstrated that keratinocyte-releasable stratifin (SFN) plays a critical role in skin collagen metabolism by inducing matrix metalloproteinase 1 (MMP1) expression in target fibroblasts. In the present study, we examined whether SFN released from UVB-irradiated epidermal keratinocytes increases MMP1 release from dermal fibroblasts, and whether these events are affected by p-coumaric acid (p-CA), a natural phenolic compound with UVB-shielding and antioxidant properties. HaCaT cells were exposed to UVB in the absence and presence of p-CA, and the conditioned medium was used to stimulate fibroblasts in medium transfer experiments. The cells and media were analyzed to determine the expressions/releases of SFN and MMP1. UVB exposure increased SFN release from keratinocytes into the medium. The conditioned medium of UVB-irradiated keratinocytes increased MMP1 release from fibroblasts. The depletion of SFN using a siRNA rendered the conditioned medium of UVB-irradiated keratinocytes ineffective at stimulating fibroblasts to release MMP1. p-CA mitigated UVB-induced SFN expression in keratinocytes, and attenuated the MMP1 release by fibroblasts in medium transfer experiments. In conclusion, the present study demonstrated that the use of UV absorbers such as p-CA would reduce UV-induced SFN-centered signaling events involved in skin photoaging.

Association of matrix metalloproteinase-1 -519A/G polymorphism with acute coronary syndrome: a meta-analysis

Matrix metalloproteinase-1 (MMP-1) has been demonstrated to play an important role in the development and progression of acute coronary syndrome (ACS). Recent studies have shown that MMP-1 -519A/G (rs1144393) polymorphism is associated with the susceptibility to ACS. However, published studies showed inconsistent results. Therefore, a meta-analysis of eligible studies reporting the association between -519A/G polymorphism and ACS was carried out. A systematic search was conducted using PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure and Chinese Wan Fang database. Six eligible studies involving 5670 subjects (2868 ACS patients and 2802 healthy controls) were included in this meta-analysis. Overall, this meta-analysis showed a significant association between the rs1144393 polymorphism and ACS (A vs. G: OR = 1.385, 95% CI = 1.019-1.882, P = 0.037; AA vs.

AG/GG

OR = 1.547, 95% CI = 1.002-2.389, P = 0.049). Furthermore, subgroup analyses also displayed significant associations between MMP-1 rs1144393 polymorphism and susceptibility to acute myocardial infarction (AA/AG vs. GG: OR = 1.275, 95% CI = 1.016-1.600, P = 0.036) or unstable angina pectoris subjects (A vs. G: OR = 2.128, 95% CI = 1.696-2.670, P < 0.001; AA vs. GG: OR = 2.933, 95% CI = 1.339-6.421, P = 0.007; AA vs.

AG/GG

OR = 2.477, 95% CI = 1.457-4.211, P = 0.001). But we found no significant association between the -519A/G polymorphism and ACS either in Asian or Caucasian. In conclusion, our meta-analysis suggests that MMP-1 -519A/G polymorphism was associated with the susceptibility to ACS. However, further large scale case-control studies with rigorous design should be conducted to confirm above conclusions in the future.

Anti-elastase, anti-tyrosinase and matrix metalloproteinase-1 inhibitory activity of earthworm extracts as potential new anti-aging agent

OBJECTIVE

To examine whether earthworms of Eisenia fetida, Lumbricus rubellus and Eudrilus eugeniae extracts have elastase, tyrosinase and matrix metalloproteinase-1 (MMP-1) inhibitory activity.

METHODS

The earthworms extract was screened for elastase, tyrosinase and MMP-1 inhibitory activity and compared with the positive controls. It was also evaluated for whitening and anti-wrinkle capacity.

RESULTS

The extract showed significantly (P<0.05) good elastase and tyrosinase inhibition and excellent MMP-1 inhibition compared to N-Isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid.

CONCLUSIONS

Earthworms extract showed effective inhibition of tyrosinase, elastase and MMP-1 activities. Therefore, this experiment further rationalizes the traditional use of this worm extracts which may be useful as an anti-wrinkle agent.

Redox-sensitive gene-regulatory events controlling aberrant matrix metalloproteinase-1 expression

Aberrant matrix metalloproteinase-1 (MMP-1) expression contributes to the pathogenesis of many degenerative disease processes that are associated with increased oxidative damage or stress. We and others have established that shifts in steady-state H2O2 production resulting from enforced antioxidant gene expression, senescence, or UV irradiation control MMP-1 expression. Here we establish that histone deacetylase-2 (HDAC2) protein levels and its occupancy of the MMP-1 promoter are decreased in response to enforced manganese superoxide dismutase (Sod2) expression. Inhibition of HDAC activity further accentuates the redox-dependent expression of MMP-1. Sod2-dependent decreases in HDAC2 are associated with increases in a proteasome-sensitive pool of ubiquitinylated HDAC2 and MMP-1-specific histone H3 acetylation. Sod2 overexpression also enhanced recruitment of Ets-1, c-Jun, c-Fos, and the histone acetyltransferase PCAF to the distal and proximal regions of the MMP-1 promoter. Furthermore, the Sod2-dependent expression of MMP-1 can be reversed by silencing the transcriptional activator c-Jun. All of the above Sod2-dependent alterations are largely reversed by catalase coexpression, indicating that the redox control of MMP-1 is H2O2-dependent. These findings identify a novel redox regulation of MMP-1 transcription that involves site-specific promoter recruitment of both activating factors and chromatin-modifying enzymes, which converge to maximally drive MMP-1 gene expression.

Interleukin-1β and cyclic AMP mediate the invasion of sheared chondrosarcoma cells via a matrix metalloproteinase-1-dependent mechanism

Matrix metalloproteinase-1 (MMP-1) is a potential biomarker for chondrosarcoma that is overexpressed at the invading edges of articular cartilage, and its expression correlates with poor survival rates. However, the molecular mechanisms of MMP-1 regulation and its potential contribution to chondrosarcoma cell invasion have yet to be elucidated, especially in shear-activated cells. Using molecular biology tools and an in vitro fluid shear model, we report that shear stress upregulates cyclic AMP (cAMP) and interleukin-1β (IL-1β) release, which in turn promotes the invasion of chondrosarcoma cells via the induction of MMP-1 in a phosphoinositide 3-kinase (PI3-K)- and ERK1/2-dependent manner. Activated PI3-K and ERK1/2 signaling pathways phosphorylate c-Jun, which in turn transactivates MMP-1 in human chondrosarcoma cells. Collectively, fluid shear stress upregulates matrix MMP-1 expression, which is responsible for the enhanced invasion of human chondrosarcoma cells.

Association of D2-40 and MMP-1 expression with cyst formation in lung metastatic lesions of cutaneous angiosarcoma on the scalp: immunohistochemical analysis of 23 autopsy cases

Cutaneous angiosarcoma of the scalp can rapidly develop into pulmonary metastasis. The pulmonary metastatic lesions display a unique appearance, so-called thin-walled cysts, which cause a fatal relapsed pneumothorax by rupturing. We analyzed 23 autopsy cases of angiosarcoma with pulmonary metastasis to elucidate the mechanism of the thin-walled cyst development. Of the 23 cases of cutaneous angiosarcoma of the scalp with pulmonary metastasis, radiological examination revealed pulmonary metastatic lesions as thin-walled cysts (39%), nodules (39%), mixed cysts and nodules (13%), and ground-glass opacity (9%). All the cases but one with cystic metastases were complicated by pneumothorax. The cystic lesions were accompanied by podoplanin (D2-40)-positive tumor cells in the luminal surface of the cysts. In both primary cutaneous lesions and pulmonary metastatic lesions, the D2-40 expression was positive for angiosarcoma cells in 100% and 92% of the cases, respectively. While the estrogen-regulated gene (ERG) expression was also positive for most of the primary and metastatic pulmonary angiosarcomas, D2-40 was a more useful marker to differentiate tumor cells from the background than was the ERG expression of the vascular endothelium. Matrix metalloproteinase-1 (MMP-1) expression was also predominant in primary lesions (95%) and pulmonary metastatic lesions (82.6%). Proteinases, like MMP-1, might be associated with a developing thin-walled cyst, although there were no differences in the MMP-1 expression in either the cystic or nodular metastasis. Two extremely aggressive cases showed cystic metastasis with central necrosis that was not observed in other cases. These results suggest a pathogenesis of thin-walled cysts in some progressive cases.

Collaborative overexpression of matrix metalloproteinase-1 and vascular endothelial growth factor-C predicts adverse prognosis in patients with gliomas

BACKGROUND AND AIM

Matrix metalloproteinase-1 (MMP-1), a member of the MMP family of zinc-dependent endopeptidases, has been detected to be strongly expressed in gliomas with high tumor grade and to be correlated with increased tumor invasiveness. Vascular endothelial growth factor-C (VEGF-C), which is able to induce MMP-1 transcription, has been found to be upregulated in glioblastoma compared to low grade gliomas and non-neoplastic brain. The aim of the present study was to investigate the clinical significance of the co-expression of MMP-1 and VEGF-C in glioma patients on determining the prognosis.

METHODS

One hundred and sixteen glioma patients (26 World Health Organization (WHO) grade I, 30 WHO grade II, 30 WHO grade III, and 30 WHO grade IV) and 15 non-neoplastic brain specimens acquired from 15 patients undergoing surgery for epilepsy as control were collected. Immunohistochemistry was used to evaluate the expression of MMP-1 and VEGF-C in glioma and non-neoplastic brain tissues. The correlations of collaborative MMP-1 and VEGF-C expression with selected clinicopathologic parameters and clinical outcome of glioma patients were also assessed.

RESULTS

Both MMP-1 and VEGF-C expression were significantly higher in glioma tissues compared to non-neoplastic brain tissues (both P<0.001). Of 116 glioma patients, 68 (58.62%) overexpressed MMP-1 and VEGF-C simultaneously. In addition, combined MMP-1 and VEGF-C expression was significantly associated with WHO grade (P<0.001) and Karnofsky performance status (KPS) score (P=0.01). Moreover, glioma patients expressing both MMP-1 and VEGF-C exhibited markedly poorer overall survival (P<0.001). According to the multivariate analyses, collaborative overexpression of MMP-1 and VEGF-C was found to be an independent prognostic factor for overall survival (P=0.009).

CONCLUSIONS

Our data demonstrated for the first time that overexpression of both MMP-1 and VEGF-C may be an independent poor prognostic factor in gliomas, suggesting the interaction between MMP-1 and VEGF-C collaboratively stimulated advanced tumor progression and adverse outcome. Inhibiting both MMP-1 and VEGF-C could be a novel therapeutic approach for gliomas.

Processed Panax ginseng, Sun Ginseng Increases Type I Collagen by Regulating MMP-1 and TIMP-1 Expression in Human Dermal Fibroblasts

In the present study, effects of sun ginseng (SG) on the collagen synthesis and the proliferation of dermal fibroblast were investigated. Collagen synthesis was measured by assaying procollagen type I C-peptide production. In addition, the level of matrix metalloproteinase (MMP)-1 was assessed by western blot analysis. SG suppressed the MMP-1 protein level in a dose-dependent manner. In contrast, SG dose-dependently increased tissue inhibitors of MMP (TIMP)-1 production in fibroblasts. SG increased type I collagen production directly and/or indirectly by reducing MMP-1 and stimulating TIMP-1 production in human dermal fibroblasts. SG dose-dependently induced fibroblast proliferation and this, in turn, can trigger more collagen production. These results suggest that SG may be a potential pharmacological agent with anti-aging properties in cultured human skin fibroblast.

Levels of matrix metalloproteinase-1 and tissue inhibitors of metalloproteinase-1 in gastric cancer

AIM: To evaluate the levels of preoperative serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in gastric cancer.

METHODS: One hundred gastric cancer patients who underwent gastrectomy were enrolled in this study. The serum concentrations of MMP-1 and TIMP-1 in these patients and in fifty healthy controls were determined using an enzyme-linked immunosorbent assay.

RESULTS: Higher serum MMP-1 and TIMP-1 levels were observed in patients than in controls (P < 0.001). Serum MMP-1 and TIMP-1 levels were positively associated with morphological appearance, tumor size, depth of wall invasion, lymph node metastasis, liver metastasis, perineural invasion, and pathological stage. They were not significantly associated with age, gender, tumor location, or histological type.

CONCLUSION: Increased MMP-1 and TIMP-1 were associated with gastric cancer. Although these markers are not good markers for diagnosis, these markers show in advanced gastric cancer.

Clinical significance of plasma MMP-1 and TIMP-1 measurement in patients with ulcerative colitis

AIM: To determine the plasma level of matrix metalloproteinase-1 (MMP-1) and its tissue inhibitor of metalloproteinase-1(TIMP-1) in patients with ulcerative colitis (UC) and to investigate their clinical significance.

METHODS: ELISA assay was used to determine the plasma MMP-1 and TIMP-1 level in the peripheral venous blood samples from 30 pathologically confirmed UC patients and 15 normal healthy controls.

RESULTS: Plasma levels of MMP-1 and TIMP-1 were significantly higher in patients with UC than in normal controls (2.4421 ± 0.5394 vs 1.8967 ± 0.3737, 6.3728 ± 0.4940 vs 5.5917 ± 0.2968, both P < 0.05); Plasma level of TIMP-1 was positively correlated with the severity of the disease (t = 4.097, P < 0.05), but that of MMP-1 wasn't; Plasma level of MMP-1 in moderate to severe patients was significantly higher than that in controls, but no significant difference was found between mild patients and control groups.

CONCLUSION: Plasma level of MMP-1 and TIMP-1 are significantly elevated in patients with UC; Plasma MMP-1, particularly plasma TIMP-1 could be considered as simple biological parameters for the severity and clinical diagnosis of UC.

Protective effect of ilomastat on trinitrobenzenesulfonic acid-induced ulcerative colitis in rats

AIM: To evaluate the protective effects of ilomastat, an exogenous matrix metalloproteinase (MMP) inhibitor, on trinitrobenzenesulfonic acid (TNB)-induced ulcerative colitis (UC) in rats.

METHODS: Male SD rats were randomly divided into model group, protective groups A and B, and normal control group. Rats in the model group received only intra-colonic TNB. Rats in the protective groups A and B received intra-peritoneal ilomastat of 10 mg/kg and 20 mg/kg, respectively, beside TNB. Rats in the normal control group received only intra-colonic normal saline. After 3 wk, segments of colon were obtained. RT-PCR and immunohistochemistry were used to examine the expression of MMP-1 and TIMP-1. Hematoxylin-eosin (HE) staining was used for pathological study.

RESULTS: The model of UC was successfully induced in rats. Inflammation of colonic mucosa greatly improved in protective groups A and B. Expression of MMP-1 and TIMP-1 in the model group, protective groups A and B was significantly higher than that in the normal control group (P < 0.0001) with MMP-1 expression increased more significantly than TIMP-1 expression. Expression of MMP-1 in protective groups A and B was significantly lower than that in the model group (P < 0.0001) . Expression of MMP-1 in protective group B was significantly lower than that in protective group A (P < 0.0001).

CONCLUSION: Ilomastat improves TNB-induced UC in rats by inhibiting the MMP-1 activity.

Expression of matrix metalloproteinase-1 and tumor necrosis factor-α in ulcerative colitis

AIM: To examine the expression of matrix metallo-proteinase-1 (MMP-1) and tumor necrosis factor-α (TNF-α) in the colon mucosa of patients with ulcerative colitis (UC).

METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were used to examine the expression of MMP-1 and TNF-α at both mRNA and protein levels in the colon mucosa of patients with UC. Correlation between MMP-1 and TNF-α and their correlation with the severity of the disease were also analyzed statistically.

RESULTS: The expression of MMP-1 and TNF-α in the ulcerated and inflamed colon mucosa of patients with UC was significantly higher than that in the non-inflamed mucosa of normal controls at both mRNA and protein levels. Furthermore, the expression of MMP-1 and TNF-α in the ulcerated area was significantly higher than that in the inflamed area of patients with UC (0.9797 ± 0.1433 vs 0.6746 ± 0.0373, 0.8669 ± 0.0746 vs 0.5227 ± 0.0435, P < 0.05). There was no statistically significant difference in the non-inflamed area of normal controls. There was a significant correlation between MMP-1 and TNF-α expression (0.9797 ± 0.1433 vs 0.8669 ± 0.0746, P < 0.05), the correlating factor was 0.877. MMP-1 and TNF-α showed a significant correlation with the severity of the disease (0.0915 ± 0.0044 vs 0.0749 ± 0.0032 , 0.0932 ± 0.0019 vs 0.0724 ± 0.0043, P < 0.05), their correlating factors were 0.942 and 0.890, respectively.

CONCLUSION: Excessively expressed MMP-1 directly damages the colon mucosa by degrading extracellular matrix (ECM) in patients with UC. While damaging colon mucosa, excessively expressed TNF-α stimulates MMPs secreting cells to produce more MMP-1 and aggravates the mucosa damage. MMP-1 promotes secretion of TNF-α in a positive feedback manner to cause further injury in the colon mucosa. MMP-1 and TNF-α correlate well with the severity of the disease, and therefore, can be used clinically as biological markers to judge the severity of UC.

Expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in ulcerative colitis

AIM: To examine the expression of metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the colonic mucosa of patients with ulcerative colitis (UC).

METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were used to study the expression of MMP-1 and TIMP-1 at both mRNA and protein levels in patients with UC and controls. The relationship between MMP-1 mRNA, TIMP-1 mRNA, MMP-1 mRNA/TIMP-1 mRNA ratio and the severity of clinical symptoms of the patients with UC were also analyzed.

RESULTS: The expression of MMP-1 mRNA and TIMP-1 mRNA in the ulcerated and inflamed colonic mucosa was significantly higher than that in the non-inflamed colonic mucosa (P < 0.001), but there was no statistically significant difference in the non-inflamed colonic mucosa of UC patients and normal controls (P > 0.05). The mRNA expression of MMP-1 and TIMP-1 in ulcerated colonic mucosa of UC patients was increased by 80-fold and 2.2-fold, respectively when compared with the normal controls. In the inflamed colonic mucosa, the increase was 30-fold and 1.6-fold, respectively. Immunohistochemical analysis showed that among the ulcerated, inflamed, and non-inflamed colonic mucosae of UC patients and the normal controls, the positive rate of MMP-1 expression was 87%, 87%, 40% and 35% respectively, and the positive rate of TIMP-1 expression was 89%, 89%, 80% and 75%, respectively. Furthermore, the expression of MMP-1 mRNA, TIMP-1 mRNA and the MMP-1 mRNA/ TIMP-1 mRNA ratio were correlated with the severity of clinical symptoms (P <0.05).

CONCLUSION: Excessive expression of MMP-1 in the diseased colonic mucosa causes excessive hydrolysis of the extracellular matrix (ECM) and ulceration in UC patients. MMP-1 mRNA, TIMP-1 mRNA and MMP-1 mRNA/TIMP-1 mRNA ratio can be used as biomarkers to judge the severity of clinical symptoms in patients with UC. Exogenous TIMP-1 or MMP-1 inhibitor therapy is a novel treatment for patients with UC.

Dynamic change of MMP-1/TIMP-1 expression in experimental immune hepatic fibrosis

AIM: To evaluate the roles of matrix metalloproteinase-1/ tissue inhibitor of metalloproteinse-1 (MMP-1/TIMP-1) in the course of formation and progression of liver fibrosis.

METHODS: Forty-eight female SD rats, 120-150 g in weight, were divided randomly into 2 groups, 8 rats in normal control group and 40 rats in fibrosis group. The fibrotic animal model was established according to the method of Blackwell with some modifications. Human serum albumin (HSA)-sensitized rats were further attacked by i. v. injection of HSA through the coccygeal vein. Liver tissues were obtained 0, 2, 4, 6, and 8 weeks after the attack. Liver hydroxyproline (HYP) content was determined, and HE, argentophilic as well as Van Gieson's (VG) stainings were performed to monitor the process of fibroproliferation. The protein and RNA of MMP-1/TIMP-1 were analyzed using ELISA and semi-quantitative RT-PCR, respectively.

RESULTS: Gradual formation of hepatic fibrosis was detected in the rats, which indicated an ideal model to study the process of generation and development of fibrosis. MMP-1 protein was present in the normal liver, with no significant change in fibrosis and cirrhosis (P>0.05). In contrast, TIMP-1 protein was increased progressively (P<0.01, after 4 weeks), reaching the peak in the stage of cirrhosis (the value after 8 wks was increased by 4 folds). In consistence with the changes of the proteins, MMP-1 mRNA expression did not alter significantly during the fibrosis process (P>0.05), while TIMP-1 mRNA expression was increased gradually (P<0.01, after 4 weeks). MMP-1/TIMP-1 ratio tended to decrease in this process. The change was more profound after 4 weeks (P<0.01). Moreover, the extent of the increase of TIMP-1 and the decrease of MMP-1/TIMP-1 ratio was well correlated with the extent of fibrosis, as revealed by the study of rats in different groups with different grades of fibroproliferation.

CONCLUSION: The main cause responsible for the deposition of extracellular matrix (ECM) during fibrosis might not be a gradual decrease in MMP-1 level, but a progressing increase in TIMP-1 level, which suppresses the activity of MMP-1 so as to diminish matrix degradation. A gradual decrease of MMP-1/TIMP-1 ratio during this process indicates a progressing disproportion between MMP-1 and TIMP-1, which accelerates the fibrosis process. TIMP-1 expression and MMP-1/TIMP-1 ratio are two useful indexes to reflect the fibrotic extent.