Matrix metalloproteinase-7 induces E-cadherin cleavage in acid-exposed primary human pharyngeal epithelial cells via the ROS/ERK/c-Jun pathway

Laryngopharyngeal reflux disease (LPRD) is caused by pharyngeal mucosal damage due to the reflux of gastric contents, including acid, pepsin, and bile juice. Our previous study has demonstrated that LPRD is associated with the cleavage of E-cadherin, which is facilitated by the acid-activated matrix metalloproteinase-7 (MMP-7); however, the mechanism by which the acid activates MMP-7 remains unclear. The purpose of this study was to investigate the mechanism by which MMP-7 is activated in the pharyngeal epithelial cells that are exposed to acid. The levels of reactive oxygen species (ROS) were measured in the epithelial cells exposed to acid. To investigate the signaling mechanism of ROS in the expression of MMP-7, the mechanism of action of the mitogen-activated protein kinase was examined. The expression of various signaling factors was determined, according to the presence or absence of each inhibitor in the acid-exposed pharyngeal epithelial cells. To identify changes in the cleavage of E-cadherin, the integrity of the mucosal membrane was assessed using a transepithelial permeability test. We found that acid exposure increased the levels of ROS, phosphorylated-extracellular signal-regulated kinase (p-ERK) 1/2, and phosphorylated-c-Jun (p–c-Jun) in pharyngeal epithelial cells. The ROS inhibitor reduced the expression of p-ERK and MMP-7, while the ERK inhibitor reduced the expression of p–c-Jun and MMP-7. Moreover, the c-Jun inhibitor reduced the expression of MMP-7 and blocked the degradation of E-cadherin. In addition, decrease in the levels of immunostained E-cadherin and increase in transepithelial permeability after acid exposure were collectively alleviated by the inhibitors of ROS, ERK, and c-Jun. The degradation of E-cadherin that occurs after human mucosal cells are exposed to acid appears to be caused by an increase in the expression of MMP-7 via the ROS/ERK/c-Jun pathway, which is thought to be an important mechanism associated with the development of LPRD. Key messages • ROS is triggered when reflux occurs. • ROS regulates the transcription factor c-Jun via the ERK pathway. • The increase in MMP-7 that induces LPRD is induced via the ROS/ERK/c-Jun pathway. • This study revealed for the first time the expression mechanism of MMP-7, which is one of the causes of LPRD.

The Roles of Matrix Metalloproteinase 7 in Spinal Cord Ischemia- Reperfusion Injury in Rats

Background: Neuronal survival after spinal cord ischemia-reperfusion injury (SCII) is a major factor affecting the motor function. Recently, matrix metalloproteinase-7 (MMP-7) plays an important role in a variety of diseases, but the specific role of MMP-7 in SCII remains unclear. This paper aims to further investigate the role of MMP7 in SCII.Methods: We built the SCII model by clipping the aortic arch for 14 minutes. The RNA and protein expression of MMP-7 was detected by Western blot and real-time polymerase chain reaction (PCR) during the groups. The co-localization of major cell types and MMP-7 in the spinal cords was detected by Immunofluorescence staining. To further study the specific mechanism, rats were intrathecally pretreated with si-MMP7 or negative control (NC) siRNA 3 days before clipping the aortic arch for 14 minutes. The Tarlov criteria and Haematoxylin and eosin staining were used to detect neurological function and histological assessment. Western blot, PCR and Immunofluorescence staining were used to evaluate the effect of silencing MMP-7.Results: The expression of MMP-7 RNA and protein increased both at 12 h and 24 h after SCII. At 24 h after SCII, the expression of MMP-7 RNA reached its maximum amount. Compared with the sham group, MMP-7 fluorescent expression in the SCII group greatly enhanced, and MMP-7 fluorescence was mainly co-expressed with neuronal nuclei (NeuN) fluorescence. The Tarlov scores and number of intact neurons were increased by pre-treatment with si-MMP7. Pre-treatment with si-MMP7 could also decrease the expression of MMP-7, Interleukin-1β (IL-1β) and cleaved caspase-3 and reduce the MMP-7 expression in neurons. Conclusions: Silencing MMP-7 protected the rats against SCII by inhibiting the neuroapoptosis and inflammation. Silencing MMP-7 could be a hopeful therapeutic treatment after SCII.

Bacteroides fragilis Enterotoxin Upregulates Matrix Metalloproteinase-7 Expression through MAPK and AP-1 Activation in Intestinal Epithelial Cells, Leading to Syndecan-2 Release

Bacteroides fragilis enterotoxin (BFT) produced by enterotoxigenic B. fragilis (ETBF) causes colonic inflammation. BFT initially contacts intestinal epithelial cells (IECs) and affects the intestinal barrier. Although molecular components of the gut epithelial barrier such as metalloproteinase-7 (MMP-7) and syndecan-2 are known to be associated with inflammation, little has been reported about MMP-7 expression and syndecan-2 shedding in response to ETBF infection. This study explores the role of BFT in MMP-7 induction and syndecan-2 release in IECs. Stimulating IECs with BFT led to the induction of MMP-7 and the activation of transcription factors such as NF-κB and AP-1. MMP-7 upregulation was not affected by NF-κB, but it was related to AP-1 activation. In BFT-exposed IECs, syndecan-2 release was observed in a time- and concentration-dependent manner. MMP-7 suppression was associated with a reduction in syndecan-2 release. In addition, suppression of ERK, one of the mitogen-activated protein kinases (MAPKs), inhibited AP-1 activity and MMP-7 expression. Furthermore, the suppression of AP-1 and ERK activity was related to the attenuation of syndecan-2 release. These results suggest that a signaling cascade comprising ERK and AP-1 activation in IECs is involved in MMP-7 upregulation and syndecan-2 release during exposure to BFT.

Matrix Metalloproteinase-7 Aggravated the Oxidized Low Density Lipoprotein-Induced Damage of Human Vascular Endothelial Cells

Introduction: Vascular endothelial injury could induce many cardiovascular diseases. Recently, some studies have indicated that matrix metalloproteinase-7 (MMP-7) was associated with the occurrence and development of cardiovascular diseases. However, whether higher levels of MMP-7 were associated with the occurrence of the vascular endothelial injury is unclear. Material and methods: In this study, ox-LDL was used for the simulation of vascular endothelial injury in HUVECs. Next, we detected the expression of MMP-7 in these cells. After that, we established the cell models with MMP-7 overexpression and knockdown, respectively. At last, the apoptosis and inflammation of HUVECs were detected with corresponding assays. Results: After the stimulation of ox-LDL, the expression of MMP-7 was enhanced compared to the control groups. After the stimulation of ox-LDL and the overexpression of MMP-7, the apoptosis rates of HUVECs were enhanced, while MMP-7 knockdown led to the decreased apoptosis rates of these cells. Furthermore, after the stimulation of ox-LDL and overexpression of MMP-7, the expression of inflammatory factors (IL-6, IL-1β and TNF-α) was promoted. Additionally, the expression of these proteins was repressed after knockdown of MMP-7. Conclusion: MMP-7 aggravated the ox-LDL-induced damage of HUVECs by promoting the apoptosis and inflammation of these cells.

A systematic review of blood biomarkers with individual participant data meta-analysis of matrix-metalloproteinase-7 in IPF

BackgroundBlood derived biomarkers have been extensively described as potential prognostic markers in idiopathic pulmonary fibrosis (IPF), but studies have been limited by analyses using data-dependent thresholds, inconsistent adjustment for confounders and an array of endpoints, thus often yielding ungeneralisable results. Meta-analysis of individual participant data (IPD) is a powerful tool to overcome these limitations. Through systematic review of blood derived biomarkers, sufficient studies with measurements of Matrix Metalloproteinase-7 (MMP-7) were identified to facilitate standardised analyses of the prognostic potential of this biomarker in IPF.MethodsElectronic databases were searched on 12th November 2020 to identify prospective studies reporting outcomes in patients with untreated IPF, stratified according to at least one pre-specified biomarker, measured at either baseline, or change over three months. Individual participant data (IPD) was sought for studies investigating MMP-7 as a prognostic factor. The primary outcome was overall mortality according to standardised MMP-7 z-scores, with a secondary outcome of disease progression in 12 months, all adjusted for age, gender, smoking and baseline FVC.ResultsIPD was available for nine studies out of twelve identified, reporting outcomes from 1664 participants. Baseline MMP-7 levels were associated with increased mortality risk (adjusted HR1.23, 95%CI 1.03;1.48, I2=64.3%) and disease progression (adjusted OR1.27, 95%CI 1.11;1.46, I2=5.9%). In limited studies, three-month change in MMP-7 was not associated with outcomes.ConclusionIPD meta-analysis demonstrated greater baseline MMP-7 levels were independently associated with an increased risk of poor outcomes in patients with untreated IPF, whilst short term changes did not reflect disease progression.

Dynamic Analysis of Serum MMP-7 and Its Relationship with Disease Progression in Biliary Atresia: A Multicenter Prospective Study

PurposeWe aimed to assess the dynamic changing trend of serum matrix metalloproteinase-7 (MMP-7) in BA patients from diagnosis to LTx to further elucidate its clinical value in diagnosis and prognoses and its relationship with disease progression.MethodsIn this multicentre prospective study, a total of 440 cholestasis patients (direct bilirubin level of > 17 μmol/L) were enrolled. Serum and stool MMP-7 levels were measured using an enzyme-linked immunosorbent assay at different time points and analysed. The polymorphism of MMP-7 was assessed to explore the possible reasons for the low value in BA patients.Results:In neonate biliary atresia patients, using a cut-off value of > 26.73 ng/ml, serum MMP-7 had a AUC of 0.954. A genetic mutation (G137D) and rapid degradation of MMP-7 in serum samples could cause low MMP-7 levels in serum of BA patients. Four dynamic patterns of serum MMP-7 post-KPE were associated with prognosis. A high concentration of MMP-7 in the stool is linked to a decreased serum MMP-7 concentration. MMP-7 showed a mediation effect on the association between inflammation and liver fibrosis in BA patients. Serum MMP-7 was the only significant predictor at six weeks post-KPE and the most accurate predictor at three months post-KPE of survival with the native liver (SNL) in two years.Conclusion:As one of the critical factors associated with BA occurrence and progression, serum MMP-7 can be used for early diagnosis of BA and post-KPE MMP-7 level is the earliest prognostic biomarker so far.

Usefulness of matrix metalloproteinase-7 in saliva as a diagnostic biomarker for laryngopharyngeal reflux disease

Several diagnostic methods are currently being used to diagnose LPRD (laryngopharyngeal reflux disease), but have the disadvantage of being invasive, subjective, or expensive. Our purpose in this study was to investigate the correlation between pepsin and MMP-7 (Matrix Metalloproteinase-7) in pharyngeal secretions of subjects according to RSI (Reflux Symptom Index) score to find out the diagnostic value of MMP-7. We recruited 173 subjects aged between 19 and 85 years who completed the RSI scale. All samples were taken after waking up, and the amount of the pepsin and MMP-7 in saliva were measured by means of an enzyme activity assay. There was a significant increase of pepsin and MMP-7 activity in the study group with an RSI score of 13 or higher. The sensitivity and specificity of MMP-7 for predicting the possibility of an RSI of 13 or more was higher than that of pepsin. When MMP-7 and pepsin were combined, this sensitivity and specificity increased. An enzyme assay of MMP-7 in saliva may be a noninvasive and easy technique for diagnosing LPRD.

Matrix Metalloproteinase-7 Induces E-Cadherin Cleavage in Acid-Exposed Primary Human Pharyngeal Epithelial Cells Via The ROS/ERK/c-Jun Pathway

Introduction Laryngopharyngeal reflux disease (LPRD) is caused by pharyngeal mucosal damage due to the reflux of gastric contents, including acid, pepsin, and bile juice. Our previous study has demonstrated that LPRD is associated with the cleavage of E-cadherin, which is facilitated by the acid-activated matrix metalloproteinase-7 (MMP-7); however, the mechanism by which the acid activates MMP-7 remains unclear. The purpose of this study was to investigate the mechanism by which MMP-7 is activated in the pharyngeal epithelial cells that are exposed to acid. Methods The levels of reactive oxygen species (ROS) were measured in the epithelial cells exposed to acid. To investigate the signaling mechanism of ROS in the expression of MMP-7, the mechanism of action of the mitogen-activated protein kinase was examined. The expression of various signaling factors were determined, according to the presence or absence of each inhibitor in the acid-exposed pharyngeal epithelial cells. To identify changes in the cleavage of E-cadherin, the integrity of the mucosal membrane was assessed using a transepithelial permeability test.ResultsWe found that acid exposure increased the levels of ROS, phosphorylated-extracellular signal-regulated kinase (p-ERK) 1/2, and phosphorylated-c-Jun (p-c-Jun) in pharyngeal epithelial cells. The ROS inhibitor reduced the expression of p-ERK and MMP-7, while the ERK inhibitor reduced the expression of p-c-Jun and MMP-7. Moreover, the c-Jun inhibitor reduced the expression of MMP-7 and blocked the degradation of E-cadherin. In addition, decrease in the levels of immunostained E-cadherin and increase in transepithelial permeability after acid exposure were collectively alleviated by the inhibitors of ROS, ERK, and c-Jun. Conclusions The degradation of E-cadherin that occurs after human mucosal cells are exposed to acid appears to be caused by an increase in the expression of MMP-7 via the ROS/ERK/c-Jun pathway, which is thought to be an important mechanism associated with the development of LPRD.