Time trajectories and within-subject correlations of matrix metalloproteinases 3, 8, 9, 10, 12, and 13 serum levels and their ability to predict mortality in polytraumatized patients: a pilot study

BACKGROUND

Managing polytrauma victims poses a significant challenge to clinicians since applying the same therapy to patients with similar injury patterns may result in different outcomes. Using serum biomarkers hopefully allows for treating each multiple injured in the best possible individual way. Since matrix metalloproteinases (MMPs) play pivotal roles in various physiological processes, they might be a reliable tool in polytrauma care.

METHODS

We evaluated 24 blunt polytrauma survivors and 12 fatalities (mean age, 44.2 years, mean ISS, 45) who were directly admitted to our Level I trauma center and stayed at the intensive care unit for at least one night. We determined their MMP3, MMP8, MMP9, MMP10, MMP12, and MMP13 serum levels at admission (day 0) and on days 1, 3, 5, 7, and 10.

RESULTS

Median MMP8, MMP9, and MMP12 levels immediately rose after the polytrauma occurred; however, they significantly decreased from admission to day 1 and significantly increased from day 1 to day 10, showing similar time trajectories and (very) strong correlations between each two of the three enzyme levels assessed at the same measurement point. For a two-day lag, autocorrelations were significant for MMP8 (- 0.512) and MMP9 (- 0.302) and for cross-correlations between MMP8 and MMP9 (- 0.439), MMP8 and MMP12 (- 0.416), and MMP9 and MMP12 (- 0.307). Moreover, median MMP3, MMP10, and MMP13 levels significantly increased from admission to day 3 and significantly decreased from day 3 to day 10, showing similar time trajectories and an (almost) strong association between every 2 levels until day 7. Significant cross-correlations were detected between MMP3 and MMP10 (0.414) and MMP13 and MMP10 (0.362). Finally, the MMP10 day 0 level was identified as a predictor for in-hospital mortality. Any increase of the MMP10 level by 200 pg/mL decreased the odds of dying by 28.5%.

CONCLUSIONS

The time trajectories of the highly varying individual MMP levels elucidate the involvement of these enzymes in the endogenous defense response following polytrauma. Similar time courses of MMP levels might indicate similar injury causes, whereas lead-lag effects reveal causative relations between several enzyme pairs. Finally, MMP10 abundantly released into circulation after polytrauma might have a protective effect against dying.

The low expression of matrix metalloproteinases: a key to longevity?

Over the past few decades, it has become clear that an excessive activity of matrix metalloproteinases (MMPs) can accelerate the progression and fatal outcomes of several serious age-related diseases, including atherosclerotic coronary heart disorders and various types of malignancies. These proteolytic enzymes mediate the degradation and remodeling of the extracellular matrix through cleaving its various components, thereby affecting many critical functions of surrounding cells and intercellular communication. Consequently, the low expression levels of MMPs can be important in the prevention and treatment of such chronic life-threatening pathologies, contributing to the better quality of life and longer life expectancy. In this review article, the pathogenic proteolytic roles of MMPs are examined in more detail, especially in the cases of heart attack and stroke as well as cancer invasion and metastasis, showing that these enzymes can be considered not only as diagnostic and prognostic biomarkers but also as important therapeutic targets in the fight against many age- and lifestyle-related serious disorders. The identification and development of suppressing agents with a selective activity towards specific MMPs have, however, still remained a complex and complicated challenge, in which natural plant-derived compounds are increasingly recognized as promising leads for the new-generation inhibitors.

Applicability of an active matrix metalloproteinase-8 point-of-care test in an oral and maxillofacial surgery clinic: a pilot study

OBJECTIVES

Matrix metalloproteinases are enzymes that participate in numerous inflammatory responses and have been targeted as biomarkers in numerous pathologic states. The detection of active matrix metalloproteinase-8 (aMMP-8) using a mouthrinse point-of-care test (POCT) has emerged as a diagnostic marker for periodontitis and other systemic inflammatory states. The objective of this pilot study was to assess the applicability of aMMP-8 POCT in an oral and maxillofacial surgery clinic and to evaluate the relationship between aMMP-8 levels and different patient groups.

MATERIALS AND METHODS

aMMP-8 POCT samples were collected from patients in an oral and maxillofacial surgery clinic during a one-month period. aMMP-8 levels were analyzed using a chairside lateral-flow immunotest and a digital reader. Clinically relevant patient variables were collected and descriptively evaluated. aMMP-8 levels over 20 ng/ml were considered to be elevated.

RESULTS

A total of 115 patients were interviewed of which 112 agreed to the test (97.4%). Elevated aMMP-8 levels were observed in 58 (51.8%) patients. Bone loss was noted in 75 (67.0%) patients. Of these patients, aMMP-8 levels were elevated in 47 (62.7%) patients. Patients at an increased risk of infection had 35.5% higher aMMP-8 values on average compared to patients with no prior illnesses.

CONCLUSION

aMMP-8 POCT provides a non-invasive and reliable method for measuring aMMP-8 levels. Future studies are warranted to assess the clinical relevance between elevated aMMP-8 levels and specific patient groups.

CLINICAL RELEVANCE

The rapid availability of the test score allows an immediate impact on treatment planning.

Extracellular matrix turnover: phytochemicals target and modulate the dual role of matrix metalloproteinases (MMPs) in liver fibrosis

Extracellular matrix (ECM) resolution by matrix metalloproteinases (MMPs) is a well-documented mechanism. MMPs play a dual and complex role in modulating ECM degradation at different stages of liver fibrosis, depending on the timing and levels of their expression. Increased MMP-1 combats disease progression by cleaving the fibrillar ECM. Activated hepatic stellate cells (HSCs) increase expression of MMP-2, -9, and -13 in different chemicals-induced animal models, which may alleviate or worsen disease progression based on animal models and the stage of liver fibrosis. In the early stage, elevated expression of certain MMPs may damage surrounding tissue and activate HSCs, promoting fibrosis progression. At the later stage, downregulation of MMPs can facilitate ECM accumulation and disease progression. A number of phytochemicals modulate MMP activity and ECM turnover, alleviating disease progression. However, the effects of phytochemicals on the expression of different MMPs are variable and may depend on the disease models and stage, and the dosage, timing and duration of phytochemicals used in each study. Here, we review the most recent advances in the role of MMPs in the effects of phytochemicals on liver fibrogenesis, which indicates that further studies are warranted to confirm and define the potential clinical efficacy of these phytochemicals.

NADPH oxidase 1: A target in the capacity of dimeric ECG and EGCG procyanidins to inhibit colorectal cancer cell invasion

Colorectal cancer (CRC) is prevalent worldwide. Dietary consumption of procyanidins has been linked to a reduced risk of developing CRC. The epidermal growth factor (EGF) receptor (EGFR) signaling pathway is frequently dysregulated in CRC. Our earlier research showed that the procyanidin dimers of epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), through their interaction with lipid rafts, inhibit the EGFR signaling pathway and decrease CRC cell growth. The process of cancer cell invasion and metastasis involves matrix metalloproteinases (MMPs), which are partially EGFR-regulated. This study investigated whether ECG and EGCG dimers can inhibit EGF-induced CRC cell invasion by suppressing the redox-regulated activation of the EGFR/MMPs pathway. Both dimers mitigated EGF-induced cell invasion and the associated increase of MMP-2/9 expression and activity in different CRC cell lines. In Caco-2 cells, both dimers inhibited the activation of the EGFR and downstream of NF-κB, ERK1/2 and Akt, which was associated with decreased MMP-2/9 transcription. EGF induced a rapid NOX1-dependent oxidant increase, which was diminished by both ECG and EGCG dimers and NOX inhibitors (apocynin, Vas-2870, DPI). Both dimers inhibited NOX1 gene expression, as well as NOX1 activity with evidence of direct binding to NOX1. Both dimers, all NOX chemical inhibitors and NOX1 silencing inhibited EGF-mediated activation of the EGFR signaling pathway and the increased MMP-2/9 mRNA levels and activity. Pointing to the relevance of NOX1 on ECG and EGCG dimer effects on CRC invasiveness, silencing of NOX1 also inhibited EGF-stimulated Caco-2 cell invasion. In summary, ECG and EGCG dimers can act inhibiting CRC cell invasion/metastasis both, by downregulating MMP-2 and MMP-9 expression via a NOX1/EGFR-dependent mechanism, and through a direct inhibitory effect on MMPs enzyme activity.

Paper-Based Biosensor for the Detection of Sepsis Using MMP-9 Biomarker in FIP Mice Model

Sepsis is an immune response to a microbial invasion that causes organ injury and dysfunction due to a systemic inflammatory response. Sepsis is a serious, life-threatening condition and a widely recognized global health challenge. Given its high death rate, it is critical to diagnose sepsis and start treatment as early as possible. There is an urgent need for a sensitive and rapid screening method for detecting sepsis. In this study, we investigated the use of MMP-9 as a biomarker for sepsis. A colorimetric paper-based biosensor was used for the detection of MMP-9 utilizing peptide-magnetic nanoparticle conjugates. The method is based on the cleavage of the MMP-9-specific peptide by the protease leading to the detaching of the magnetic beads from the sensor surface and changing of color. A fecal intraperitoneal (FIP) challenge was used to induce sepsis in mice, and an MMP-9 secretion was measured by taking blood and Bronchoalveolar Lavage (BAL) fluid samples at 1 h, 2 h, 4 h, and 20 h (early sepsis) post-challenge intervals. The results of the paper-based sensor for the detection of MMP-9 levels in blood samples and BAL samples were compared with ELISA and Western Blot. We found that both blood and BAL levels of MMP-9 increased immediately and could be detected as early as 1 h in FIP mice post-challenge. Our work adds evidence to the assertion that MMP-9 is a reliable biomarker for the detection of sepsis at early stages.

The role of neutrophil extracellular traps and proinflammatory damage-associated molecular patterns in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of systemic autoimmune diseases characterized by immune-mediated muscle injury. Abnormal neutrophil extracellular traps (NETs) can be used as a biomarker of IIM disease activity, but the mechanism of NET involvement in IIMs needs to be elucidated. Important components of NETs, including high-mobility group box 1, DNA, histones, extracellular matrix, serum amyloid A, and S100A8/A9, act as damage-associated molecular patterns (DAMPs) to promote inflammation in IIMs. NETs can act on different cells to release large amounts of cytokines and activate the inflammasome, which can subsequently aggravate the inflammatory response. Based on the idea that NETs may be proinflammatory DAMPs of IIMs, we describe the role of NETs, DAMPs, and their interaction in the pathogenesis of IIMs and discuss the possible targeted treatment strategies in IIMs.

A functional MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk in a southern Chinese population

Background

The role of matrix metalloproteinase 9 (MMP-9) in the pathophysiology of chronic kidney disease (CKD), which is associated with a nearly two-fold greater risk for urinary calculi compared to people without CKD, has been demonstrated. The aim of the research is to evaluate the association between MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk.

Methods

A hospital-based case-control study involving 302 kidney stone patients and 408 controls without kidney stone from southern China was conducted. Sanger sequencing was used to genotype the MMP-9-1562C>T polymorphism. The serum MMP-9 was measured in 105 kidney stone patients and 77 controls by enzyme-linked immunosorbent assay.

Results

Compared to the control group, the CT genotype was more frequent in nephrolithiasis patients (adjusted OR = 1.60, 95% CI = 1.09-2.37: the risk of developing nephrolithiasis in individuals with CT genotype compared to CC genotype). Moreover, there was also a higher frequency of CT/TT genotypes among patients with nephrolithiasis (adjusted OR = 1.49, 95% CI = 1.02-2.19: the risk of developing nephrolithiasis in individuals with CT/TT genotypes compared to CC genotype). The risk remained for the subgroups of patients aged >53, smokers with pack-years of smoking >20, non-drinkers, non-diabetic patients, patients with hypertension, recurrent episodes and calcium oxalate stones (OR = 2.26, 95% CI = 1.31-3.91; OR = 5.47, 95% CI = 1.10-27.30; OR = 1.76, 95% CI = 1.14-2.72; OR = 1.54, 95% CI = 1.03-2.30; OR = 1.97, 95% CI = 1.01-3.82; OR = 1.67, 95% CI = 1.06-2.62; OR = 1.54, 95% CI = 1.02-2.32, respectively). Biochemical parameters did not differ between genotypes. Compared to controls (18.57 ± 5.80 ng/mL), nephrolithiasis patients had significantly higher serum MMP-9 levels (30.17 ± 6.78 ng/mL, p < 0.001). The serum MMP-9 levels of patients with CT/TT genotypes of MMP-9-1562C>T were significantly higher than those with CC genotype (32.00 ± 6.33 vs. 29.13 ± 6.85 ng/mL, p = 0.037).

Conclusion

The MMP-9-1562C>T polymorphism in association with its soluble protein increased the risk of kidney stone, thus suggesting it could be used as a susceptibility biomarker for nephrolithiasis. Further functional studies and larger studies that include environmental exposure data are needed to confirm the findings.

A lesion-selective albumin-CTLA4Ig as a safe and effective treatment for collagen-induced arthritis

BACKGROUND

CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG₁ that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.

METHODS

We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.

RESULTS

Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.

CONCLUSIONS

Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

Potential Biomarkers for Early Diagnosis, Evaluation, and Prognosis of Sepsis-Induced Coagulopathy

Sepsis-induced coagulopathy (SIC) is a life-threatening complication characterized by the systemic activation of coagulation in sepsis. The diagnostic criteria of SIC consist of three items, including Sequential Organ Failure Assessment (SOFA) score, platelet count, and prothrombin time (PT)-international normalized ratio (INR). SIC has a high prevalence and it can lead to a higher mortality rate and longer length of hospital and ICU stay. Thus, the early detection of SIC is extremely important. It is unfortunate that there is still no precise biomarker for early diagnosis and assessment of the prognosis of SIC. We reviewed the current literature and discovered that some potential biomarkers, such as soluble thrombomodulin (sTM), thrombin-antithrombin complex (TAT), tissue plasminogen activator-inhibitor complex (t-PAIC), α2-plasmin inhibitor-plasmin complex (PIC), C-type lectin-like receptor 2 (CLEC-2), neutrophil extracellular traps (NETs), prothrombin fragment 1.2 (F1.2), Angiopoietin-2 (Ang-2), plasminogen activator inhibitor-1 (PAI-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) may be useful for early diagnosis, evaluation, and prognosis of SIC. Early initiation of treatment without missing any therapeutic opportunities may improve SIC patients' prognosis. Further large-scale clinical studies are still needed to confirm the role of these biomarkers in the diagnosis and prognosis assessment of SIC.

Serum Level of MMP-3 and MMP-9 in Patients with Diabetes Mellitus Type 2 Infected with Epstein-Barr Virus

Diabetes mellitus type 2 (DM2) has recently become one of the most important health problems in the world. Patients with DM2 with long-term glycaemia are more likely to become infected than the healthy population. Matrix metalloproteinases (MMPs) play a key role in tissue remodeling during various physiological processes. However, it has been reported that certain MMPs are overexpressed during the development of various human diseases. In this study, we analyzed the levels of MMP-3 and MMP-9 in the serum of DM2 patients with and without Epstein-Barr virus (EBV) infection. The study included 115 patients with DM2 hospitalized in the Internal Ward of the Masovian Specialist Hospital in Radom, Poland, who were divided into two groups: EBV-positive and EBV-negative. The levels of MMP-3 and MMP-9 were tested in the serum of patients using the ELISA method, while the presence of EBV in saliva was tested by polymerase chain reaction (PCR). The presented studies showed a significant difference in the concentration of both MMPs in diabetic patients additionally infected with EBV compared to the group of non-infected individuals. It seems that MMPs may be useful biomarkers in the diagnosis, prognosis, and monitoring of diabetes associated with EBV infection.

The Effect of Thiamine, Ascorbic Acid, and the Combination of Them on the Levels of Matrix Metalloproteinase-9 (MMP-9) and Tissue Inhibitor of Matrix Metalloproteinase-1 (TIMP-1) in Sepsis Patients

Background

Methods

Results

Conclusion

Matrix metaloproteinases in vascular pathology

Vascular diseases are the main cause of morbidity and mortality. The vascular extracellular matrix (ECM) is essential in mechanical support, also regulating the cellular behavior fundamental to vascular function and homeostasis. Vascular remodeling is an adaptive response to various physiological and pathological changes and is associated with aging and vascular diseases. The aim of this review is provide a general overview of the involvement of MMPs in the pathogenesis of vascular diseases, namely, arterial hypertension, atherosclerosis, aortic aneurysms and myocardial infarction. The change in the composition of the ECM by matrix metalloproteinases (MMPs) generates a pro-inflammatory microenvironment that modifies the phenotypes of endothelial cells and vascular smooth muscle cells. They play a central role in morphogenesis, tissue repair and remodeling in response to injury, e.g., after myocardial infarction, and in progression of diseases such as atherosclerosis. Alterations in specific MMPs could influence arterial remodeling and lead to various pathological disorders such as hypertension and aneurysm formation. MMPs are regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio generally determines the extent of ECM protein degradation and tissue remodeling. Studies are currently focused on improving the diagnostic and prognostic value of MMPs involved in the pathogenic process, increasing their therapeutic potential, and monitoring the disease. New selective MMP inhibitors may improve the specificity of these inhibitors, target specific MMPs in relevant pathological conditions and mitigate some of the side effects.

Correlation of Matrix Metalloproteinase-9 and Tissue Inhibitor Matrix Metalloproteinase-1 on Lactate Concentration in Sepsis patients Admitted to Intensive Care Unit

BACKGROUND: Lactate level has been used not only as a biomarker for diagnosis and guiding treatment of sepsis but also as predictor of poor clinical outcomes. Elevated lactate does not specifically reflect cellular damage and this condition can be seen in other metabolic disorders. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are two new promising biomarkers that have been reported to elevate significantly in sepsis. These two biomarkers can reflect physiological changes in tissue and cellular levels. AIM: This study aims to identify the correlation of MMP-9, TIMP-1, and MMP-9/TIMP-1 on lactate levels in sepsis patients. METHODS: This was a cross-sectional study conducted in two hospitals, Adam Malik General Hospital, Medan, and Grand Medistra Hospital, Deli Serdang, between April 2020 and May 2021. The inclusion criteria in this study were adult sepsis patients who were admitted to ICU, with Sequential Organ Failure Assessment (SOFA) or quick SOFA score ≥ 2. We recorded the characteristics, MMP-9, TIMP-1, and lactate concentration before given any intervention. The data were then analyzed to find the correlation. RESULTS: Sixty-four patients were included in this study which consisted of almost equal men and women. The mean age of the subjects was 52.16 ± 16.25 years old. There was no correlation between MMP-9 and TIMP-1 toward lactate concentration (p = 0.466 and p = 0.65, respectively). CONCLUSION: Our study showed no correlation between MMP-9 and TIMP-1 toward lactate concentration.

Transcriptomic Biomarker Signatures for Discrimination of Oral Cancer Surgical Margins

Relapse after surgery for oral squamous cell carcinoma (OSCC) contributes significantly to morbidity, mortality and poor outcomes. The current histopathological diagnostic techniques are insufficiently sensitive for the detection of oral cancer and minimal residual disease in surgical margins. We used whole-transcriptome gene expression and small noncoding RNA profiles from tumour, close margin and distant margin biopsies from 18 patients undergoing surgical resection for OSCC. By applying multivariate regression algorithms (sPLS-DA) suitable for higher dimension data, we objectively identified biomarker signatures for tumour and marginal tissue zones. We were able to define molecular signatures that discriminated tumours from the marginal zones and between the close and distant margins. These signatures included genes not previously associated with OSCC, such as MAMDC2, SYNPO2 and ARMH4. For discrimination of the normal and tumour sampling zones, we were able to derive an effective gene-based classifying model for molecular abnormality based on a panel of eight genes (MMP1, MMP12, MYO1B, TNFRSF12A, WDR66, LAMC2, SLC16A1 and PLAU). We demonstrated the classification performance of these gene signatures in an independent validation dataset of OSCC tumour and marginal gene expression profiles. These biomarker signatures may contribute to the earlier detection of tumour cells and complement existing surgical and histopathological techniques used to determine clear surgical margins.

Use of human bone marrow mesenchymal stem cells immortalized by the expression of telomerase in wound healing in diabetic rats

Diabetes mellitus is associated with neural and micro- and macrovascular complications. Therapeutic options for these complications are limited and the delivery of mesenchymal stem cells into lesions have been reported to improve the healing process. In this work, the effects of the administration of a lineage of human bone marrow mesenchymal stem cells immortalized by the expression of telomerase (hBMSC-TERT) as a potential therapeutic tool for wound healing in diabetic rats were investigated. This is the first description of the use of these cells in diabetic wounds. Dorsal cutaneous lesions were made in streptozotocin-induced diabetic rats and hBMSC-TERT were subcutaneously administered around the lesions. The healing process was evaluated macroscopically, histologically, and by birefringence analysis. Diabetic wounded rats infused with hBMSC-TERT (DM-TERT group) and the non-diabetic wounded rats not infused with hBMSC-TERT (CW group) had very similar patterns of fibroblastic response and collagen proliferation indicating improvement of wound healing. The result obtained by birefringence analysis was in accordance with that obtained by the histological analysis. The results indicated that local administration of hBMSC-TERT in diabetic wounds improved the wound healing process and may become a therapeutic option for wounds in individuals with diabetes.

Peptide-based electrochemical biosensors utilized for protein detection

Proteins are generally detected as biomarkers for tracing or determining various disorders in organisms. Biomarker proteins can be tracked in samples with various origins and in different concentrations, revealing whether an organism is in a healthy or unhealthy state. In regard to detection, electrochemical biosensors are a potential fusion of electronics, chemistry, and biology, allowing for fast and early point-of-care detection from a biological sample with the advantages of high sensitivity, simple construction, and easy operation. Peptides present a promising approach as a biorecognition element when connected with electrochemical biosensors. The benefits of short peptides lie mainly in their good stability and selective affinity to a target analyte. Therefore, peptide-based electrochemical biosensors (PBEBs) represent an alternative approach for the detection of different protein biomarkers. This review provides a summary of the past decade of recently proposed PBEBs designed for protein detection, dividing them according to different protein types: (i) enzyme detection, including proteases and kinases; (ii) antibody detection; and (iii) other protein detection. According to these protein types, different sensing mechanisms are discussed, such as the peptide cleavage by a proteases, phosphorylation by kinases, presence of antibodies, and exploiting of affinities; furthermore, measurements are obtained by different electrochemical methods. A discussion and comparison of various constructions, modifications, immobilization strategies and different sensing techniques in terms of high sensitivity, selectivity, repeatability, and potential for practical application are presented.

Matrix metalloproteinase-9 -1562 C/T polymorphism is associated with the risk of sepsis in a Chinese population: A retrospective study

Matrix metalloproteinase-9 (MMP-9) has been shown to participate in the pathogenesis of sepsis. In this study, we recruited 312 sepsis patients and 413 controls to explore the relationship between sepsis risk and the MMP-9 -1562 C/T polymorphism in Han Chinese. The PCR restriction fragment length polymorphism method was used for genotyping. Our data indicated that the MMP-9 -1562 C/T polymorphism was related with the risk of sepsis (CT vs. CC: P = 0.033, odds ratio (OR) = 1.45, 95% confidence interval (CI) 1.03–2.05; TT+CT vs. CC: P = 0.019, OR = 1.49, 95% CI 1.07–2.07). Stratified analyses demonstrated that this effect was more evident in smokers, drinkers, females and overweight individuals. Furthermore, cross-over analyses suggested that the combined effect of smoking and CT genotype of -1562 C/T polymorphism contributed to the risk of sepsis. In addition, MMP-9 serum levels were significantly lower in sepsis patients than in controls. The MMP-9 -1562 C/T polymorphism was significantly associated with decreased MMP-9 serum levels. Lastly, we observed that this polymorphism was connected to the mortality of sepsis. In conclusion, the interaction between the MMP-9 -1562 C/T polymorphism and smoking correlated with the risk of sepsis in Han Chinese. This polymorphism may serve as a diagnostic marker for sepsis patients.

Metal-Enhanced Fluorescence by Bifunctional Au Nanoparticles for Highly Sensitive and Simple Detection of Proteolytic Enzyme

Although fluorescence-based analytical methods have been used in intracellular analyses, their sensitivity is low for the precise analysis of intracellular proteolytic enzymes to observe cell apoptosis related to cancer and neurodegenerative diseases. In this study, a metal-enhanced-fluorescence (MEF)-based highly sensitive biosensor for the detection of proteolytic enzymes is proposed for the first time by using a bifunctional Au nanoparticle (AuNP), which is connected to the fluorophore by both single-stranded DNA (ssDNA) and a peptide. Once caspase-3, a proteolytic enzyme, cuts the peptide specifically, the fluorescence signal is drastically increased because the ssDNA maintains an optimal distance for the MEF. The proposed sensing method shows the highly sensitive detection of caspase-3 based on just a simple enzymatic cleavage reaction within 1 h, and caspase-3-related preapoptotic cell detection was successfully carried out with high sensitivity. The proposed sensing method is a rapid, simple, and one-step technique for the real-time monitoring of intracellular proteolytic enzymes and can be applied to the early diagnosis of cancer and neurodegenerative diseases.

Ab locks for improving the selectivity and safety of antibody drugs

Monoclonal antibodies (mAbs) are a major targeted therapy for malignancies, infectious diseases, autoimmune diseases, transplant rejection and chronic inflammatory diseases due to their antigen specificity and longer half-life than conventional drugs. However, long-term systemic antigen neutralization by mAbs may cause severe adverse events. Improving the selectivity of mAbs to distinguish target antigens at the disease site from normal healthy tissue and reducing severe adverse events caused by the mechanisms-of-action of mAbs is still a pressing need. Development of pro-antibodies (pro-Abs) by installing a protease-cleavable Ab lock is a novel and advanced recombinant Ab-based strategy that efficiently masks the antigen binding ability of mAbs in the normal state and selectively "turns on" the mAb activity when the pro-Ab reaches the proteolytic protease-overexpressed diseased tissue. In this review, we discuss the design and advantages/disadvantages of different Ab lock strategies, focusing particularly on spatial-hindrance-based and affinity peptide-based approaches. We expect that the development of different masking strategies for mAbs will benefit the local reactivity of mAbs at the disease site, increase the therapeutic efficacy and safety of long-term treatment with mAbs in chronic diseases and even permit scientists to develop Ab drugs for formerly undruggable targets and satisfy the unmet medical needs of mAb therapy.

Longitudinal evaluation of Wnt inhibitors and comparison with others serum osteoimmunological biomarkers in osteolytic bone metastasis

Bone and the immune system are closely linked: bone regulates the hematopoietic stem cells, which are precursors of immune cells, and several immunoregulatory cytokines influence the differentiation of bone cells, thus defining the osteoimmunological system. Cytokines and growth factors produced by immune and bone cells promote tumors in bone, supporting the vicious cycle of bone metastasis. Therefore osteoimmunological molecules linking the immune and bone systems could have diagnostic and prognostic potential for bone metastases. The osteoimmunologic Wnt pathway has been recently described as an important pathway with a vital role in bone carcinogenesis and metastatic progression. We examined the Wnt inhibitor DKK-1, sclerostin and several other osteoimmunological biomarkers involved in bone metastatic progression: RANKL, OPG, OPN, matrix metalloproteinase MMP-3 and the Receptor of Advanced Glycosylated End-products sRAGE. OPN and sclerostin proved good biomarkers of metastatic bone progression; the RANKL/OPG ratio was a good indicator of bone erosion in the metastatic process, while sRAGE had a protective role against metastatic progression in bone. These results serve to define a panel of new osteoimmunological biomarkers that could be useful in assessing the progress of osteolytic bone metastases.

Recent Advances in Capillary Electrochromatography of Proteins and Carbohydrates in the Biopharmaceutical and Biomedical Field

Capillary electrochromatography (CEC) is a powerful hybrid separation technique that combines capillary electrophoresis and capillary chromatography, capable to address the analytical challenges of proteomics and glycomics. The focus of this paper is to review the recent developments in capillary electrochromatography of proteins and carbohydrates. The different column types applied in capillary electrochromatography such as packed bed, open tubular and monoliths are conferred in detail with respective separation examples. A comprehensive comparison is also given listing the mostly utilized coating methods, stationary phase materials and column preparation methods. The choice of porogenic solvent combinations for monolithic column fabrication is thoroughly discussed, paying close attention to the fine tuning options for the separation driving electroosmotic flow. Application examples of CEC in process analytical technology for the biopharmaceutical and biomarker discovery in the biomedical fields are also given.

MMP-2 and MMP-9 in Human Peripheral Blood: Optimizing Gelatinase Calibrator for Degradome Research and Discovering a Novel Gelatinolytic Enzyme

Matrix metalloprotease-2 and -9 (gelatinase A and B, respectively) are enzymes crucially involved in a plethora of physiopathological conditions. Gelatin zymography is considered one of the major qualitative/semiquantitative assays for simultaneously determining zymogenic, active, and complexed forms of gelatinases. Critical steps are represented by variations in sample collection methods, molecular weight standard calibrators, and different zymography assay protocols. A normalization of these aspects is required for reducing discrepancies in technical procedures and interpreting results among different laboratories. In this study, we describe a novel protocol for gelatin zymography with increased pore size, which improves the separation of gelatinases with different molecular weights. A new method for obtaining gelatinase calibrator for gelatin zymography, by extracting MMP-2 and MMP-9 from peripheral blood, is also reported. Our method provides a gelatinase calibrator with enhanced stability both at room temperature and during multiple freeze-thaw cycles. This calibrator preparation is also suitable for in vitro post-translational modifications. For the first time, the improved zymography protocol allowed us to reveal in human peripheral blood samples new gelatinolytic bands resolved at very high molecular weight, likely complexes of MMP-9, undetectable with classical zymography protocols.

Hypoxia-Activated PEGylated Conditional Aptamer/Antibody for Cancer Imaging with Improved Specificity

Aptamers and antibodies, as molecular recognition probes, play critical roles in cancer diagnosis and therapy. However, their recognition ability is based on target overexpression in disease cells, not target exclusivity, which can cause on-target off-tumor effects. To address the limitation, we herein report a novel strategy to develop a conditional aptamer conjugate which recognizes its cell surface target, but only after selective activation, as determined by characteristics of the disease microenvironment, which, in our model, involve tumor hypoxia. This conditional aptamer is the result of conjugating the aptamer with PEG₅₀₀₀-azobenzene-NHS, which is responsive to hypoxia, here acting as a caging moiety of conditional recognition. More specifically, the caging moiety is unresponsive in the intact conjugate and prevents target recognition. However, in the presence of sodium dithionite or hypoxia (<0.1% O₂) or in the tumor microenvironment, the caging moiety responds by allowing conditional recognition of the cell-surface target, thereby reducing the chance of on-target off-tumor effects. It is also confirmed that the strategy can be used for developing a conditional antibody. Therefore, this study demonstrates an efficient strategy by which to develop aptamer/antibody-based diagnostic probes and therapeutic drugs for cancers with a unique hypoxic microenvironment.

Astrocyte-derived fatty acid-binding protein 7 protects blood-brain barrier integrity through a caveolin-1/MMP signaling pathway following traumatic brain injury

The astrocyte-endothelial cell interaction is crucial for normal brain homeostasis and blood-brain barrier (BBB) disruption in pathological conditions. However, the mechanism by which astrocytes control BBB integrity, especially after traumatic brain injury (TBI), remains unclear. Here, we present evidence that astrocyte-derived fatty acid-binding protein 7 (FABP7), a differentiation- and migration-associated molecule, may function as a modulator of BBB permeability in a rat weight-drop model of TBI. Immunohistochemical analysis revealed that TBI induced increased expression of FABP7 in astrocytes, accompanied by caveolin-1 (Cav-1) upregulation in endothelial cells. Administration of recombinant FABP7 significantly ameliorated TBI-induced neurological deficits, brain edema, and BBB permeability, concomitant with upregulation of endothelial Cav-1 and tight junction protein expression, while FABP7 knockdown resulted in the opposite effects. Furthermore, pretreatment with daidzein, a specific inhibitor of Cav-1, reversed the inhibitory effects of recombinant FABP7 on matrix metalloproteinase (MMP)-2/9 expression and abolished its BBB protection after TBI. Altogether, these findings suggest that astrocyte-derived FABP7 upregulation may represent an endogenous protective response to BBB disruption partly mediated through a Cav-1/MMP signaling pathway following TBI.

Inflammation and lung injury in an ovine model of fluid resuscitated endotoxemic shock

Background

Sepsis is a multi-system syndrome that remains the leading cause of mortality and critical illness worldwide, with hemodynamic support being one of the cornerstones of the acute management of sepsis. We used an ovine model of endotoxemic shock to determine if 0.9% saline resuscitation contributes to lung inflammation and injury in acute respiratory distress syndrome, which is a common complication of sepsis, and investigated the potential role of matrix metalloproteinases in this process.

Methods

Endotoxemic shock was induced in sheep by administration of an escalating dose of lipopolysaccharide, after which they subsequently received either no fluid bolus resuscitation or a 0.9% saline bolus. Lung tissue, bronchoalveolar fluid (BAL) and plasma were analysed by real-time PCR, ELISA, flow cytometry and immunohistochemical staining to assess inflammatory cells, cytokines, hyaluronan and matrix metalloproteinases.

Results

Endotoxemia was associated with decreased serum albumin and total protein levels, with activated neutrophils, while the glycocalyx glycosaminoglycan hyaluronan was significantly increased in BAL. Quantitative real-time PCR studies showed higher expression of IL-6 and IL-8 with saline resuscitation but no difference in matrix metalloproteinase expression. BAL and tissue homogenate levels of IL-6, IL-8 and IL-1β were elevated.

Conclusions

This data shows that the inflammatory response is enhanced when a host with endotoxemia is resuscitated with saline, with a comparatively higher release of inflammatory cytokines and endothelial/glycocalyx damage, but no change in matrix metalloproteinase levels.

Nano-channel of viral DNA packaging motor as single pore to differentiate peptides with single amino acid difference

Detection, differentiation, mapping, and sequencing of proteins are important in proteomics for the assessment of cell development such as protein methylation or phosphorylation as well as the diagnosis of diseases including metabolic disorder, mental illness, immunological ailments, and malignant cancers. Nanopore technology has demonstrated the potential for the sequencing or sensing of DNA, RNA, chemicals, or other macromolecules. Due to the diversity of protein in shape, structure and charge and the composition versatility of 20 amino acids, the sequencing of proteins remains challenging. Herein, we report the application of the channel of bacteriophage T7 DNA packaging motor for the differentiation of an assortment of peptides of a single amino acid difference. Explicit fingerprints or signatures were obtained based on current blockage and dwell time of individual peptide. Data from the clear mapping of small proteins after protease digestion suggests the potential of using T7 motor channel for proteomics including protein sequencing.

Matrix Metalloproteinase-9 and Tissue Inhibitor of Matrix Metalloproteinase-1 in Sepsis after Major Abdominal Surgery

Background

The role of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in sepsis after major abdominal surgery and sepsis-associated organ dysfunction is unexplored.

Materials and Methods

Fifty-three patients with sepsis after major abdominal surgery were compared to 50 operated and 50 nonoperated controls. MMP-9, TIMP-1, biomarkers of inflammation, kidney and liver injury, coagulation, and metabolic disorders were measured daily during 96 h following diagnosis of sepsis and once in controls. MMP-9/TIMP-1 ratios and disease severity scores were calculated. Use of vasopressors/inotropes, mechanical ventilation, and survival were recorded.

Results

Septic patients had lower MMP-9 and MMP-9/TIMP-1 ratios but higher TIMP-1 levels compared to controls. AUC-ROC for diagnosis of sepsis was 0.940 and 0.854 for TIMP-1 and 0.924 and 0.788 for MMP-9/TIMP-1 ratio (sepsis versus nonoperated and sepsis versus operated controls, resp.). Lower MMP-9 and MMP-9/TIMP-1 ratio and higher TIMP-1 levels were associated with shorter survival. MMP-9, TIMP-1, and MMP-9/TIMP-1 ratio correlated with biomarkers of inflammation, kidney and liver injury, coagulation, metabolic disorders, and disease severity scores. Use of vasopressors/inotropes was associated with higher TIMP-1 levels.

Conclusions

MMP-9, TIMP-1, and MMP-9/TIMP ratio were good diagnostic or prognostic biomarkers of sepsis after major abdominal surgery and were linked to sepsis-associated organ dysfunction.

Inflammatory Mediator Profiles Differ in Sepsis Patients With and Without Bacteremia

Systemic levels of cytokines are altered during infection and sepsis. This prospective observational study aimed to investigate whether plasma levels of multiple inflammatory mediators differed between sepsis patients with and those without bacteremia during the initial phase of hospitalization. A total of 80 sepsis patients with proven bacterial infection and no immunosuppression were included in the study. Plasma samples were collected within 24 h of hospitalization, and Luminex^® analysis was performed on 35 mediators: 16 cytokines, six growth factors, four adhesion molecules, and nine matrix metalloproteases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs). Forty-two patients (52.5%) and 38 (47.5%) patients showed positive and negative blood cultures, respectively. There were significant differences in plasma levels of six soluble mediators between the two “bacteremia” and “non-bacteremia” groups, using Mann–Whitney U test (p < 0.0014): tumor necrosis factor alpha (TNFα), CCL4, E-selectin, vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), and TIMP-1. Ten soluble mediators also significantly differed in plasma levels between the two groups, with p-values ranging between 0.05 and 0.0014: interleukin (IL)-1ra, IL-10, CCL2, CCL5, CXCL8, CXCL11, hepatocyte growth factor, MMP-8, TIMP-2, and TIMP-4. VCAM-1 showed the most robust results using univariate and multivariate logistic regression. Using unsupervised hierarchical clustering, we found that TNFα, CCL4, E-selectin, VCAM-1, ICAM-1, and TIMP-1 could be used to discriminate between patients with and those without bacteremia. Patients with bacteremia were mainly clustered in two separate groups (two upper clusters, 41/42, 98%), with higher levels of the mediators. One (2%) patient with bacteremia was clustered in the lower cluster, which compromised most of the patients without bacteremia (23/38, 61%) (χ² test, p < 0.0001). Our study showed that analysis of the plasma inflammatory mediator profile could represent a potential strategy for early identification of patients with bacteremia.

Filamin A interacting protein 1-like expression inhibits progression in colorectal cancer

Filamin A interacting protein 1-like (FILIP1L) expression, which is decreased in various cancers, may inhibit carcinogenesis. In this study, we evaluated the effects of FILIP1L on oncogenic behavior and prognosis in colorectal cancer. siRNA-mediated FILIP1L knockdown enhanced tumor cell migration and invasion and inhibited apoptosis and cell cycle arrest in COLO205 cells. pcDNA-myc vector-mediated FILIP1L overexpression suppressed tumor cell migration and invasion and induced apoptosis and cell cycle arrest in HCT116 cells. FILIP1L knockdown enhanced angiogenesis by increasing VEGF-A and HIF-1α levels and decreasing angiostatin level. FILIP1L overexpression suppressed angiogenesis by decreasing VEGF-A and -D l level and increasing angiostatin and endostatin levels. Phosphorylated β-catenin levels decreased and phosphorylated Akt and GSK-3β levels increased following FILIP1L knockdown. FILIP1L overexpression had the opposite effects. FILIP1L expression was associated with reductions in tumor size, cell differentiation, lymphovascular invasion, stage, invasion depth and lymph node metastasis, and with longer overall survival. Mean Ki-67 labeling indexes and microvessel density values were lower in FILIP1L-positive tumors than in FILIP1L-negative tumors. These results indicate that FILIP1L suppresses tumor progression by inhibiting cell proliferation and angiogenesis in colorectal cancer.

The role of miR-766-5p in cell migration and invasion in colorectal cancer

Colorectal cancer (CRC) develops from the colon or rectum and is the fourth highest inducer of cancer mortality. In the present study, cancer tissues and normal tissues were extracted from patients with CRC who were treated in the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (Jinan, China). Reverse transcription-quantitative polymerase chain reaction demonstrated that the expression level of miR-766-5p was significantly higher (P<0.01) in cancer tissue than that in normal tissue. SW480 cells were used for in vitro study and randomly separated into the miR-negative control (NC) inhibitor treatment group and miR-766-5p inhibitor treatment group. SW480 cell behaviors were evaluated. Results demonstrated that in the miR-766-5p inhibitor group, there was a decreased level of cell proliferation/migration/invasion and higher cell apoptosis compared with that in the miR-NC inhibitor group. miR-766-5p was predicted and verified to target the 3' untranslated region of suppressor of cancer cell invasion (SCAI) in SW480 cells. Protein expression levels of matrix metalloproteinase-2/phosphoinositide 3-kinase/AKT were decreased and SCAI was increased following miR-766-5p inhibitor treatment. In conclusion, the present study indicated that miR-766-5p inhibitor repressed the process of CRC by targeting SCAI.

Predictive Value of Matrix Metalloproteinases and Their Inhibitors for Mortality in Septic Patients: A Cohort Study

Purpose:

Over 170 biomarkers are being investigated regarding their prognostic and diagnostic accuracy in sepsis in order to find new tools to reduce morbidity and mortality. Matrix metalloproteinases (MMPs) and their inhibitors have been recently studied as promising new prognostic biomarkers in patients with sepsis. This study is aimed at determining the utility of several cutoff points of these biomarkers to predict mortality in patients with sepsis.

Materials and Methods:

A multicenter, prospective, analytic cohort study was performed in the metropolitan area of Bucaramanga, Colombia. A total of 289 patients with sepsis and septic shock were included. MMP-9, MMP-2, tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, TIMP-1/MMP-9 ratio, and TIMP-2/MMP-2 ratio were determined in blood samples. Value ranges were correlated with mortality to estimate sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiving operating characteristic curve.

Results:

Sensitivity ranged from 33.3% (MMP-9/TIMP-1 ratio) to 60.6% (TIMP-1) and specificity varied from 38.8% (MMP-2/TIMP-2 ratio) to 58.5% (TIMP-1). As for predictive values, positive predictive value range was from 17.5% (MMP-9/TIMP-1 ratio) to 70.4% (MMP-2/TIMP-2 ratio), whereas negative predictive values were between 23.2% (MMP-2/TIMP-2 ratio) and 80.9% (TIMP-1). Finally, area under the curve scores ranged from 0.31 (MMP-9/TIMP-1 ratio) to 0.623 (TIMP-1).

Conclusion:

Although TIMP-1 showed higher sensitivity, specificity, and negative predictive value, with a representative population sample, we conclude that none of the evaluated biomarkers had significant predictive value for mortality.

Matrix Metalloproteinases in Bone Resorption, Remodeling, and Repair

Matrix metalloproteinases (MMPs) are the major protease family responsible for the cleavage of the matrisome (global composition of the extracellular matrix (ECM) proteome) and proteins unrelated to the ECM, generating bioactive molecules. These proteins drive ECM remodeling, in association with tissue-specific and cell-anchored inhibitors (TIMPs and RECK, respectively). In the bone, the ECM mediates cell adhesion, mechanotransduction, nucleation of mineralization, and the immobilization of growth factors to protect them from damage or degradation. Since the first description of an MMP in bone tissue, many other MMPs have been identified, as well as their inhibitors. Numerous functions have been assigned to these proteins, including osteoblast/osteocyte differentiation, bone formation, solubilization of the osteoid during bone resorption, osteoclast recruitment and migration, and as a coupling factor in bone remodeling under physiological conditions. In turn, a number of pathologies, associated with imbalanced bone remodeling, arise mainly from MMP overexpression and abnormalities of the ECM, leading to bone osteolysis or bone formation. In this review, we will discuss the functions of MMPs and their inhibitors in bone cells, during bone remodeling, pathological bone resorption (osteoporosis and bone metastasis), bone repair/regeneration, and emergent roles in bone bioengineering.

Narrowband ultraviolet B light treatment changes plasma concentrations of MMP-3, MMP-9 and TIMP-3 in psoriatic patients

Background

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are thought to be associated with the pathogenesis and spread of psoriatic disease. This study was designed to investigate the plasma levels of MMP-3, MMP-9 and TIMP-3 in plaque psoriasis patients prior to and following a course of ultraviolet B narrowband treatment with respect to disease advancement.

Methods

Plasma samples of 49 patients suffering from plaque psoriasis and 40 healthy volunteers were evaluated. Concentrations of MMP-3, MMP-9 and TIMP-3 were determined using enzyme-linked immunosorbent assay, while Psoriasis Area and Severity Index was used to define disease advancement.

Results

Plasma levels of MMP-3, MMP-9 and TIMP-3 were significantly elevated in psoriasis patients compared to healthy individuals. A course of ultraviolet B narrowband treatment resulted in a significant decline in the studied metalloproteinases. Furthermore, the concentration of selected tissue inhibitors was negatively correlated with baseline Psoriasis Area and Severity Index score.

Conclusion

Our research highlights the meaningful role of MMP-3, MMP-9 and TIMP-3 in psoriasis pathogenesis and clearance of disease symptoms. Furthermore, plasma levels of the analyzed metalloproteinases seem to be a valuable psoriasis biomarker.

Unveiling differentially expressed genes upon regulation of transcription factors in sepsis

In this study, we integrated the gene expression data of sepsis to reveal more precise genome-wide expression signature to shed light on the pathological mechanism of sepsis. Differentially expressed genes via integrating five microarray datasets from the Gene Expression Omnibus database were obtained. The gene function and involved pathways of differentially expressed genes (DEGs) were detected by GeneCodis3. Transcription factors (TFs) targeting top 20 dysregulated DEGs (including up- and downregulated genes) were found based on the TRANSFAC. A total of 1339 DEGs were detected including 788 upregulated and 551 downregulated genes. These genes were mostly involved in DNA-dependent transcription regulation, blood coagulation, and innate immune response, pathogenic escherichia coli infection, epithelial cell signaling in helicobacter pylori infection, and chemokine signaling pathway. TFs bioinformatic analysis of 20 DEGs generated 374 pairs of TF-target gene involving 47 TFs. At last, we found that five top ten upregulated DEGs (S100A8, S100A9, S100A12, PGLYRP1 and MMP9) and three downregulated DEGs (ZNF84, CYB561A3 and BST1) were under the regulation of three hub TFs of Pax-4, POU2F1, and Nkx2-5. The identified eight DEGs may be regarded as the diagnosis marker and drug target for sepsis.

Matrix Metalloproteinase 9 in Epilepsy: The Role of Neuroinflammation in Seizure Development

Matrix metalloproteinase 9 is a proteolytic enzyme which is recently one of the more often studied biomarkers. Its possible use as a biomarker of neuronal damage in stroke, heart diseases, tumors, multiple sclerosis, and epilepsy is being widely indicated. In epilepsy, MMP-9 is suggested to play a role in epileptic focus formation and in the stimulation of seizures. The increase of MMP-9 activity in the epileptic focus was observed both in animal models and in clinical studies. MMP-9 contributes to formation of epileptic focus, for example, by remodeling of synapses. Its proteolytic action on the elements of blood-brain barrier and activation of chemotactic processes facilitates accumulation of inflammatory cells and induces seizures. Also modification of glutamatergic transmission by MMP-9 is associated with seizures. In this review we will try to recapitulate the results of previous studies about MMP-9 in terms of its association with epilepsy. We will discuss the mechanisms of its actions and present the results revealed in animal models and clinical studies. We will also provide a comparison of the results of various studies on MMP-9 levels in the context of its possible use as a biomarker of the activity of epilepsy.

C-peptide exhibits a late induction effect on matrix metallopeptidase-9 in high glucose-stimulated rat mesangial cells

Insufficient matrix metalloproteinase (MMP)-9 and MMP-2 is considered to be a contributor of extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can reverse fibrosis, thus exerting a beneficial effect on DN. Whether C-peptide induces MMP-9 and MMP-2 to reverse ECM accumulation is not clear. In the present study, in order to determine ECM metabolism, rat mesangial cells were treated with high glucose (HG) and C-peptide intervention, then the early and late effects of C-peptide on HG-affected MMP-9 and MMP-2 were evaluated. Firstly, it was confirmed that HG mainly suppressed MMP-9 expression levels. Furthermore, C-peptide treatment induced MMP-9 expression at 6 h and suppressed it at 24 h, revealing the early dual effects of C-peptide on MMP-9 expression. Subsequently, significant increase in MMP-9 expression at 72, 96 and 120 h C-peptide treatment was observed. These changes in MMP-9 protein content confirmed its expression changes following late C-peptide treatment. Furthermore, at 96 and 120 h C-peptide treatment reversed the HG-inhibited MMP-9 secretion, further indicating the late induction effect of C-peptide on MMP-9. The present results demonstrated that C-peptide exerted a late induction effect on MMP-9 in HG-stimulated rat mesangial cells, which may be associated with the underlying mechanism of C-peptide's reversal effects on DN.

α-ketoglutarate is associated with delayed wound healing in diabetes

AIM

A high level of matrix metalloproteinase 9 (MMP-9) is a predictor of poor wound healing in diabetic foot ulcers. In skin keratinocytes, site-specific DNA demethylation plays an important role in MMP-9 expression. Ten-eleven translocation enzyme 2 (TET2) protein, one member of TET family, could rely on α-ketoglutarate (α-KG) as cosubstrate to exhibit catalytic activity of DNA demethylation. Here, we aimed to explore the changes of α-KG and its relationship with MMP-9 and TET2 during diabetic wound healing.

METHODS

Seventy-one cases of patients with diabetic foot ulcers and 53 cases of nondiabetic ulcers were enrolled. Serum, urine and wound fluids were collected for measurement of α-KG levels and MMP-9 expression. Skin tissues were collected for the measurement of TET2 and MMP-9 expression. Clinical parameters were collected, and transcutaneous oxygen pressure (TcPO2) levels of feet were detected.

RESULTS

The levels of α-KG, TET2 and MMP-9 were significantly increased in diabetic wound compared with nondiabetic wound (P = 0·010, 0·016 and 0·025). There was a significant correlation between a low TcPO2 and a high α-KG level of wound fluids (r = -0·395, P = 0·002). Further analysis showed that α-KG concentration had a positive correlation with both haemoglobin A1c (HbA1C) and 2 h postprandial blood glucose (PBG) (r = 0·393, P = 0·005; r = 0·320, P = 0·025, respectively).

CONCLUSIONS

The levels of α-KG, TET2 and MMP-9 were significantly increased in diabetic wound compared with nondiabetic wound. Elevated α-KG was related to local hypoxia ischaemia status and systematic poor glycaemic control.

Diagnostic Value of Matrix Metalloproteinase-9 and Tissue Inhibitor of Matrix Metalloproteinase-1 in Sepsis-Associated Acute Kidney Injury

Sepsis-associated acute kidney injury (SA-AKI) severely impacts morbidity and mortality in surgical patients with sepsis. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) have an important role in pathophysiology of sepsis but they have been unexplored in SA-AKI. We aimed to investigate the role of MMP-9 and TIMP-1 in septic surgical patients with SA-AKI and to evaluate them as diagnostic biomarkers of SA-AKI. This prospective observational study compared 53 major abdominal surgery patients with sepsis divided into SA-AKI (n = 37) and non-SA-AKI (n =16) group to 50 controls without sepsis matched by age, gender, comorbidities and type of surgery. Blood and urine samples from septic patients were collected on admission to ICU and 24, 48, 72 and 96 h later and once from the controls. The levels of MMP-9, TIMP-1, neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1, urea and creatinine were measured. MMP-9/TIMP-1 ratio and disease severity scores, such as Sequential Organ Failure Assessment (SOFA), were calculated. Septic patients with SA-AKI had higher serum TIMP-1 levels and lower serum MMP-9 levels and lower MMP-9/TIMP ratio, compared to septic patients without SA-AKI and controls. The levels of these biomarkers did not change significantly over time. MMP-9, TIMP-1 and MMP-9/TIMP-1 ratio correlated with urea, creatinine, NGAL, and SOFA scores. Moreover, using the area under ROC curve, we showed that TIMP-1 and MMP-9/TIMP-1 ratio, but not MMP-9, were good diagnostic biomarkers of SA-AKI. We report for the first time the potential diagnostic value of TIMP-1 and MMP-9/TIMP-1 ratio in SA-AKI.

Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries

Cardiovascular diseases are the leading causes of death in industrialized countries. Atherosclerotic coronary arteries are commonly treated with percutaneous transluminal coronary intervention followed by stent deployment. This treatment has significantly improved the clinical outcome. However, triggered vascular smooth muscle cell (SMC) proliferation leads to in-stent restenosis in bare metal stents. In addition, stent thrombosis is a severe side effect of drug eluting stents due to inhibition of endothelialization. The aim of this study was to develop and test a stent surface polymer, where cytotoxic drugs are covalently conjugated to the surface and released by proteases selectively secreted by proliferating smooth muscle cells. Resting and proliferating human coronary artery smooth muscle cells (HCASMC) and endothelial cells (HCAEC) were screened to identify an enzyme exclusively released by proliferating HCASMC. Expression analyses and enzyme activity assays verified selective and exclusive activity of the matrix metalloproteinase-9 (MMP-9) in proliferating HCASMC. The principle of drug release exclusively triggered by proliferating HCASMC was tested using the biodegradable stent surface polymer poly-l-lactic acid (PLLA) and the MMP-9 cleavable peptide linkers named SRL and AVR. The specific peptide cleavage by MMP-9 was verified by attachment of the model compound fluorescein. Fluorescein release was observed in the presence of MMP-9 secreting HCASMC but not of proliferating HCAEC. Our findings suggest that cytotoxic drug conjugated polymers can be designed to selectively release the attached compound triggered by MMP-9 secreting smooth muscle cells. This novel concept may be beneficial for stent endothelialization thereby reducing the risk of restenosis and thrombosis.

Acute phase of aortic dissection: a pilot study on CD40L, MPO, and MMP-1, -2, 9 and TIMP-1 circulating levels in elderly patients

Background

Acute aortic dissection (AAD) is an event which may be rapidly fatal without early diagnosis and treatment. Aging is one of the main risk factors that could leading to AAD. To date, no specific biomarkers are available to increase the speed of diagnosis. CD40 ligand (CD40L), myeloperoxidase (MPO), matrix metalloproteinase (MMP)-1, -2, -9 and metallopeptidase tissue inhibitor 1 (TIMP-1) are biologically related molecules which integrate inflammation, tissue injury and remodeling, all events associated to AAD.

Our is a pilot study to evaluate whether circulating levels of these molecules may be used as potential biomarkers in timely diagnosis of AAD.

Results

Within 24 h of symptom onset, circulating CD40L, MPO, MMP-1,-2,-9 and TIMP-1 were quantified by enzyme-linked immunosorbent assays in 22 patients (40–86 years of age) with AAD of ascending aorta (type A according to Stanford classification) and 11 patients with AAD of descending aorta (type B). 30 healthy individuals age matched were used as control group compared to controls, both type A and B AAD patients had higher CD40L (p < 0.001) and MPO (p < 0.01) levels. MMP-1 was higher in the overall AAD group (p < 0.01). After Stanford classification, type A group had increased level compared to both control and type B (p < 0.01 and p < 0.05, respectively). TIMP-1 was higher in both A and B groups compared to controls (p < 0.001). No differences were observed in MMP-2 and MMP-9 levels.

Conclusions

The simultaneous evaluation of CD40L, MPO and MMP-1 and TIMP-1, which may contribute to structural changes in aortic tissue in AAD patients, seems to be a novel promising diagnostic panel.

Activity of Proteolytic Enzymes and Level of Cystatin C in the Peripartum Period

Objectives. The aim of the study was to evaluate the activity of cathepsin B, collagenases, trypsin, and plasmin and concentration of cystatin C in serum of healthy pregnant women in peripartum period. Study Design. The study group included 45 women in uncomplicated pregnancies. Blood samples were collected in four time points. Enzyme activity was measured by spectrofluorometric method. The level of cystatin C was measured using immunonephelometric method. Results. Mean activity of cathepsin B and the level of serum cystatin C were significantly higher in the study group. Collagenase activity was significantly lower in the study group than the control group. No differences in collagenase, plasmin, and trypsin activity on each day of the peripartum period were found. Conclusion. High activity of cathepsin B and increased level of cystatin C are typical for women in late pregnancy. Those levels significantly decrease after delivery which can be associated with potential role of those markers in placental separation. The insignificant changes of cystatin C level in the peripartum period seem to exclude the possibility of using cystatin C as a marker for renal insufficiency in the peripartum period but additional research is necessary to investigate the matter further.

Inhibitory effect of arsenic trioxide on neuronal migration in vitro and its potential molecular mechanism

Primary neuron cultures were established from the brains of neonatal rats and the effects of arsenic trioxide (As2O3) on the migration of neurons and the potential mechanism of As2O3 were investigated. Boyden chamber assay was used to detect the effect of AS2O3 on neuronal migration. Matrix metalloproteinase-2 (MMP-2) and MMP-9 RNA expression and doublecortin (DCX) protein expression were measured. Neuronal migration ability was significantly lower in the 20 μmol/L group compared with the other three groups (all p < 0.001). The expression of both MMP-2 and MMP-9 was significantly inversely correlated with As2O3 concentration. The expression of DCX was significantly higher in the control group compared with the other three groups (all p ≤ 0.003). Thus, the inhibitory effect of As2O3 on the migration of primary neurons might be related to the reduction in MMP-2 and MMP-9 activities and decrease in β-actin and DCX expression.