Exploring the role of flavonoids in caries-affected dentin adhesion: A comprehensive scoping review

OBJECTIVES

The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin.

METHODS

A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review.

STUDY SELECTION

Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria.

RESULTS

The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs).

CONCLUSIONS

Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.

Evaluation of matrix metalloproteinase-1, -2, -3, -7, and -13 gene polymorphisms in patients with chronic periodontitis and healthy controls

OBJECTIVES

The current study aimed to investigate the association of matrix metalloproteinase- (MMP-) 1, -2, -3, -7, and -13 gene polymorphisms with chronic periodontitis (CP) in an Iranian population.

MATERIALS AND METHODS

In this case-control study, 87 subjects with CP and 89 periodontally healthy subjects were allocated to case and control groups, respectively. Subjects' venous blood samples (5 cc) were collected, and DNA extraction was performed. A spectrophotometer was utilized to assess the concentration of extracted DNAs. The desired gene polymorphisms were examined using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) followed by electrophoresis. Statistical analyses were done using the Pearson Chi-Square test, odds ratio, and t-Test using SPSS Version 28.

RESULTS

The MMP-1 (-1607 1G/2G) rs1799750, MMP-3 (-1171 5A/6A) rs3025058, and MMP-7 (-181 A/G) rs11568818 gene polymorphisms significantly differed between case and control groups (PV = 0.019, 0.007, and 0.028, respectively). In contrast, the gene polymorphisms of MMP-2 (-1306 C/T) rs243865 and MMP-13 (-77 A/G) rs2252070 did not make a significant difference. Regarding allele frequencies, the presence of the 2G allele in the MMP-1 (-1607) rs1799750 genotype increased the CP susceptibility significantly, while subjects with the 6A allele in their MMP-3 (-1171) rs3025058 genotype showed significantly lower susceptibility to CP (PV = 0.008 and < 0.001, respectively).

CONCLUSION

In the studied population, gene polymorphisms in the DNA sequences of MMP-1 (-1607 1G/2G) rs1799750, MMP-3 (-1171 5A/6A) rs3025058, and MMP-7 (-181 A/G) rs11568818 may have impacts on CP incidence.

CLINICAL RELEVANCE

Clinicians should be cautious about the association between MMP-1, MMP-3, and MMP-7 gene polymorphisms and the incidence of chronic periodontitis during periodontal treatment planning.

The mechanism of human neural stem cell secretomes improves neuropathic pain and locomotor function in spinal cord injury rat models: through antioxidant, anti-inflammatory, anti-matrix degradation, and neurotrophic activities

Background

Globally, spinal cord injury (SCI) results in a big burden, including 90% suffering permanent disability, and 60%-69% experiencing neuropathic pain. The main causes are oxidative stress, inflammation, and degeneration. The efficacy of the stem cell secretome is promising, but the role of human neural stem cell (HNSC)-secretome in neuropathic pain is unclear. This study evaluated how the mechanism of HNSC-secretome improves neuropathic pain and locomotor function in SCI rat models through antioxidant, anti-inflammatory, anti-matrix degradation, and neurotrophic activities.

Methods

A proper experimental study investigated 15 Rattus norvegicus divided into normal, control, and treatment groups (30 μL HNSC-secretome, intrathecal in the level of T10, three days post-traumatic SCI). Twenty-eight days post-injury, specimens were collected, and matrix metalloproteinase (MMP)-9, F2-Isoprostanes, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, and brain derived neurotrophic factor (BDNF) were analyzed. Locomotor recovery was evaluated via Basso, Beattie, and Bresnahan scores. Neuropathic pain was evaluated using the Rat Grimace Scale.

Results

The HNSC-secretome could improve locomotor recovery and neuropathic pain, decrease F2-Isoprostane (antioxidant), decrease MMP-9 and TNF-α (anti-inflammatory), as well as modulate TGF-β and BDNF (neurotrophic factor). Moreover, HNSC-secretomes maintain the extracellular matrix of SCI by reducing the matrix degradation effect of MMP-9 and increasing the collagen formation effect of TGF-β as a resistor of glial scar formation.

Conclusions

The present study demonstrated the mechanism of HNSC-secretome in improving neuropathic pain and locomotor function in SCI through antioxidant, anti-inflammatory, anti-matrix degradation, and neurotrophic activities.

Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia

Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.

Mechanisms of Lower Extremity Vein Dysfunction in Chronic Venous Disease and Implications in Management of Varicose Veins

Chronic venous disease (CVD) is a common venous disorder of the lower extremities. CVD can be manifested as varicose veins (VVs), with dilated and tortuous veins, dysfunctional valves and venous reflux. If not adequately treated, VVs could progress to chronic venous insufficiency (CVI) and lead to venous leg ulcer (VLU). Predisposing familial and genetic factors have been implicated in CVD. Additional environmental, behavioral and dietary factors including sedentary lifestyle and obesity may also contribute to CVD. Alterations in the mRNA expression, protein levels and proteolytic activity of matrix metalloproteinases (MMPs) have been detected in VVs and VLU. MMP expression/activity can be modulated by venous hydrostatic pressure, hypoxia, tissue metabolites, and inflammation. MMPs in turn increase proteolysis of different protein substrates in the extracellular matrix particularly collagen and elastin, leading to weakening of the vein wall. MMPs could also promote venous dilation by increasing the release of endothelium-derived vasodilators and activating potassium channels, leading to smooth muscle hyperpolarization and relaxation. Depending on VVs severity, management usually includes compression stockings, sclerotherapy and surgical removal. Venotonics have also been promoted to decrease the progression of VVs. Sulodexide has also shown benefits in VLU and CVI, and recent data suggest that it could improve venous smooth muscle contraction. Other lines of treatment including induction of endogenous tissue inhibitors of metalloproteinases (TIMPs) and administration of exogenous synthetic inhibitors of MMPs are being explored, and could provide alternative strategies in the treatment of CVD.

The effects of nanomicelle of curcumin on the matrix metalloproteinase (MMP-2, 9) activity and expression in patients with coronary artery disease (CAD): A randomized controlled clinical trial

BACKGROUND

Coronary artery disease (CAD) is the most common type of cardiovascular disease. Increasing the expression and activity of matrix metalloproteinases (MMPs) facilitates vascular remodeling and cardiovascular complications. Curcumin (the active ingredient of turmeric) is a potent natural anti-inflammatory agent, with cardiovascular protective effects. The present study was a clinical trial for investigating the effects of curcumin on activity and gene expression of MMP-2 and MMP-9 in patients with CAD.

METHODS

In this study, 70 patients with CAD (with 40%-50% stenosis) were randomly divided into two groups of curcumin (80 mg nanomicelle per day) and placebo. The intervention lasted 3 months. The activity levels of MMP-2 and MMP-9 in serum samples of patients were measured using gelatin zymography assay before and after the intervention. MMP-2 and MMP-9 gene expression in peripheral blood mononuclear cells (PBMCs) was also analyzed using real-time polymerase chain reaction (PCR). Statistical significance was set at P < 0.0500.

RESULTS

After 3 months of medication, the expression of MMP-9 produced by PBMCs significantly decreased in the curcumin group (0.811 ± 0.25) in comparison with the placebo group (2.23 ± 0.94) (P < 0.0001). Furthermore, the zymographic analysis showed that the administration of curcumin significantly inhibited the activity levels of MMP-2 (12469.7 ± 5308.64 pixels) and MMP-9 (14007.2 ± 5371.67 pixels) in comparison with that in patients receiving placebo (MMP-2: 17613.8 ± 5250.68 pixels; MMP-9: 20010.1 ± 3259.37 pixels) (P < 0.0500).

CONCLUSION

Our results show that curcumin can significantly reduce the expression and activity of MMP-2 and MMP-9. Because of the anti-inflammatory effects of curcumin, this compound can be considered as a new strategy for the prevention of cardiovascular events.

Different mechanisms of arsenic related signaling in cellular proliferation, apoptosis and neo-plastic transformation

Arsenic is a toxic heavy metal vastly dispersed all over the earth crust. It manifests several major adverse health issues to millions of arsenic exposed populations. Arsenic is associated with different types of cancer, cardiovascular disorders, diabetes, hypertension and many other diseases. On the contrary, arsenic (arsenic trioxide, As₂O₃) is used as a chemotherapeutic agent in the treatment of acute promyelocytic leukemia. Balance between arsenic induced cellular proliferations and apoptosis finally decide the outcome of its transformation rate. Arsenic propagates signals via cellular and nuclear pathways depending upon the chemical nature, and metabolic-fates of the arsenical compounds. Arsenic toxicity is propagated via ROS induced stress to DNA-repair mechanism and mitochondrial stability in the cell. ROS induced alteration in p53 regulation and some mitogen/ oncogenic functions determine the transformation outcome influencing cyclin-cdk complexes. Growth factor regulator proteins such as c-Jun, c-fos and c-myc are influenced by chronic arsenic exposure. In this review we have delineated arsenic induced ROS regulations of epidermal growth factor receptor (EGFR), NF-ĸβ, MAP kinase, matrix-metalloproteinases (MMPs). The role of these signaling molecules has been discussed in relation to cellular apoptosis, cellular proliferation and neoplastic transformation. The arsenic stimulated pathways which help in proliferation and neoplastic transformation ultimately resulted in cancer manifestation whereas apoptotic pathways inhibited carcinogenesis. Therapeutic strategies against arsenic should be designed taking into account all these factors.

Urinary MMP-9/UCr association with albumin concentration and albumin-creatinine-ratio in Mexican patients with type 2 diabetes mellitus

BACKGROUND

Chronic kidney disease is one of the most common complications of type 2 diabetes mellitus (T2DM), causing an increased risk of cardiovascular morbidity and mortality. Matrix metalloproteinase (MMP) activity has been proposed as useful biomarker for diabetic renal and vascular complications.

METHODS

A cross-sectional study was conducted among T2DM patients who attended a public secondary hospital in Mexico. We performed clinical, biochemical, and microbiological assessments, as well chronic kidney disease diagnosis according to the KDIGO guideline. Urinary MMP-9 was quantified by ELISA and adjusted using urinary creatinine (UCr).

RESULTS

A total of 111 patients were included. Most participants were women (66%). Mean age was 61 ± 10 years and median T2DM duration was estimated at 11 years. Through multivariate analysis, MMP-9/UCr was found to be associated with albumin concentration and albumin to creatinine ratio.

DISCUSSION

Validation of non-invasive biomarkers of chronic kidney disease among T2DM patients is necessary. Here, we demonstrate MMP-9/UCr as a potential biomarker of albumin concentration and albumin to creatinine ratio in Mexican patients with T2DM.

Sensory neurons from dorsal root ganglia regulate endothelial cell function in extracellular matrix remodelling

BACKGROUND

Recent physiological and experimental data highlight the role of the sensory nervous system in bone repair, but its precise role on angiogenesis in a bone regeneration context is still unknown. Our previous work demonstrated that sensory neurons (SNs) induce the osteoblastic differentiation of mesenchymal stem cells, but the influence of SNs on endothelial cells (ECs) was not studied.

METHODS

Here, in order to study in vitro the interplay between SNs and ECs, we used microfluidic devices as an indirect co-culture model. Gene expression analysis of angiogenic markers, as well as measurements of metalloproteinases protein levels and enzymatic activity, were performed.

RESULTS

We were able to demonstrate that two sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), were involved in the transcriptional upregulation of angiogenic markers (vascular endothelial growth factor, angiopoietin 1, type 4 collagen, matrix metalloproteinase 2) in ECs. Co-cultures of ECs with SNs also increased the protein level and enzymatic activity of matrix metalloproteinases 2 and 9 (MMP2/MMP9) in ECs.

CONCLUSIONS

Our results suggest a role of sensory neurons, and more specifically of CGRP and SP, in the remodelling of endothelial cells extracellular matrix, thus supporting and enhancing the angiogenesis process. Video abstract.

Ethanolic Extract of Ocimum sanctum Leaves Reduced Invasion and Matrix Metalloproteinase Activity of Head and Neck Cancer Cell Lines

Background:

Head and neck squamous cell carcinoma (HNSCC) has a yearly incidence of 600,000 cases worldwide with a low survival rate. Ocimum sanctum L. or Ocimum tenuiflorum L. (Holy basil; Tulsi in Hindi), is a traditional medicine herb that demonstrates numerous effects including anti-oxidant, anti-microbial, and anti-tumor effects. The aim of this study was to evaluate the anti-invasive effect of O. sanctum leaf extract on HNSCC cell lines.

Methods:

Ethanolic extract of O. sanctum leaf (EEOS) was prepared and the phenolic compounds were identified using high-performance liquid chromatography-electrospray ionization-time of flight-mass spectrometry. Genetically matched HNSCC cell lines derived from primary (HN30 and HN4) and metastatic sites (HN31 and HN12) from the same patient were used in this study. The EEOS cytotoxicity to the cell lines was determined using an MTT assay. The invasion and matrix metalloproteinase (MMP)-2 and -9 activity of EEOS-treated cells were tested using a modified Boyden chamber assay and zymography, respectively.

Results:

We found that EEOS significantly inhibited the invasion and MMP-2 and MMP-9 activity of HN4 and HN12 cells, but not HN30 and HN31 cells. Rosmarinic acid, caffeic acid, and apigenin were detected in EEOS. Moreover, rosmarinic acid was found as the major phenolic compound.

Conclusion:

EEOS exerted its anti-invasive effect on HNSCC cells by attenuating MMP activity. The active compounds identified in EEOS might be promising as an alternative therapeutic agent for HNSCC.

Mycobacterium avium lysate induces matrix metalloproteinase-1 in intestinal tissue and peripheral blood: Observations from selected hospital based Zambian adults

OBJECTIVES

Environmental enteropathy is prevalent in low-income countries, although its aetiology is unknown. We investigated if Mycobacterium avium antigens, which are commonly found in the environment, could contribute to its pathogenesis in a population known to have widespread environmental enteropathy.

METHODS

Routine endoscopy patients at the University Teaching Hospital, Lusaka whose endoscopy results were normal submitted duodenal biopsies and whole blood samples. Samples were stimulated with M. avium lysate over 24h while unstimulated samples served as negative controls. Matrix metalloproteinase (MMP) and cytokine response in supernatants were quantified using ELISA and cytometric bead array.

RESULTS

Samples from 48 patients (56% women) were analysed, with a median age of 35 years (IQR 27.5, 50.5). M. avium induced the secretion of a wide-range of Th1, Th2 and Th17 cytokines in blood but only IL-1β and IL-6 in duodenal tissue. However it differentially induced the secretion of MMP-1 in duodenal tissue compared to negative controls (p=0.004). A similar MMP-1 response but with lower concentrations was observed in blood.

CONCLUSION

The induction of MMP-1 and cytokines by M. avium in duodenal tissue suggests that environmental mycobacteria could contribute to the epithelial disruption seen in environmental enteropathy, and a need to further explore possible biomarkers that may predict this exposure in at-risk populations.

In vivo imaging biomarkers of neuroinflammation in the development and assessment of stroke therapies - towards clinical translation

Modulation of the inflammatory microenvironment after stroke opens a new avenue for the development of novel neurorestorative therapies in stroke. Understanding the spatio-temporal profile of (neuro-)inflammatory imaging biomarkers in detail thereby represents a crucial factor in the development and application of immunomodulatory therapies. The early integration of quantitative molecular imaging biomarkers in stroke drug development may provide key information about (i) early diagnosis and follow-up, (ii) spatio-temporal drug-target engagement (pharmacodynamic biomarker), (iii) differentiation of responders and non-responders in the patient cohort (inclusion/exclusion criteria; predictive biomarkers), and (iv) the mechanism of action. The use of targeted imaging biomarkers for may thus allow clinicians to decipher the profile of patient-specific inflammatory activity and the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in stroke. Here, we highlight the recent developments in preclinical and clinical molecular imaging biomarkers of neuroinflammation (endothelial markers, microglia, MMPs, cell labeling, future developments) in stroke and outline how imaging biomarkers can be used in overcoming current translational roadblocks and attrition in order to advance new immunomodulatory compounds within the clinical pipeline.

The Protein Extract of Chlorella minutissima Inhibits The Expression of MMP-1, MMP-2 and MMP-9 in Cancer Cells through Upregulation of TIMP-3 and Down Regulation of c-Jun

Objective

Considering the bioactivities exhibited by microalgae, the effect of protein extract of Chlorella minutissimma (CP extract) was investigated on the expression of human matrix metalloproteinases-1 (MMP-1) in the breast cancer cell line MDA-MB231, and that of MMP-2 and -9 in hepatocellular cancer cell line HepG2 at different expression levels. The study aimed identification and analysis of inhibitory activity of microalgal components extracted from Chlorella minutissima against human MMPs.

Materials and Methods

In this experimental study, we analysed the effect of Chlorella extracts on MMP-1, -2, and -9 expression at various levels. Gelatin zymography was performed to study the inhibitory effect of Chlorella exracts on human gelatinases at the activity level, followed by western blotting to analyse the expression of all three MMPs at the protein level. The similar effect at the mRNA level along with the probable mechanism underlying inhibition of MMPs was assessed using real-time polymerase chain reaction (PCR).

Results

The results reveal that the treatment with CP extract decreased the mRNA expression of MMP-1, MMP-2, and MMP-9 by 0.26-, 0.29-, and 0.40-fold, respectively, at 20 μg/ml concentration as well as inhibited the activity of MMP-2 and MMP-9 by 37.56 and 42.64%, respectively, at 15 μg/ml concentration. Additionally, upregulated mRNA expression of tissue inhibitor of metalloproteinases-3 (TIMP-3) by 1.68-fold was seen in HepG2 cells at 20 μg/ml concentration treatment group. However, CP extract did not induce any change in the mRNA expression of the TIMP-1, -2 and -4 in HepG2 and TIMP-1, -2, -3 and -4 in MDA-MB231 cells. Activator protein-1 (AP-1)-dependent c-Jun-mediated transcriptional regulation of MMP-1, -2, and -9 was also studied to elucidate the appropriate mechanism involved in the inhibition of MMPs.

Conclusion

The CP extract successfully inhibited MMP-1, -2, and -9 at different expression levels through TIMP-3 upregulation and c-Jun downregulation.

Simvastatin Therapy and Bronchoalveolar Lavage Fluid Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a progressive disease underlain by airway inflammation. Despite trials with new generations of anti-inflammatory drugs to alleviate the disease burden, the effective curative treatment remains elusive. In this context, the aim of this study was to assess the influence of simvastatin, a leading member of the family of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, known to display anti-inflammatory and immunomodulatory activity, on symptoms and lung function, as well as the proportion of inflammatory cells, cytokines, proteolytic enzymes, and surfactant protein D (SP-D) content in bronchoalveolar lavage fluid (BALF) in COPD patients. There were 50 patients with moderate-to-severe airway obstructions included into the study, subdivided into simvastatin-treated (Zocor - MSD; 40 mg daily) and control simvastatin-untreated groups, other treatment being equal. Pulmonary functions tests and bronchofiberoscopy with BALF procedure were performed before and after 3-month-long treatment in both groups. The major finding was that simvastatin treatment caused a distinct increase in the airway content of SP-D. Further effects, albeit smaller in magnitude, consisted of reductions in the proportion of airway neutrophils and in MMP-9 content, all with a benefit of improved score in the disease activity assessment test. There were no appreciable changes noted in lung function or dyspnea perception, which could be ascribed to simvastatin treatment. We conclude that statin's anti-inflammatory and surfactant homeostasis preserving properties may offer promise as an adjunctive treatment in COPD patients. The SP-D content in BALF has a potential to become a marker of COPD inflammatory activity and treatment monitoring.

PEP-1-SIRT2-induced matrix metalloproteinase-1 and -13 modulates type II collagen expression via ERK signaling in rabbit articular chondrocytes

Matrix metalloproteinases (MMPs) are critical for the degradation of the extracellular matrix (ECM), which includes cartilage-specific collagen types I, II and XI. We previously found that PEP-1-sirtuin (SIRT)2 could induce dedifferentiation of articular chondrocytes; however, the underlying mechanisms remains unclear. We addressed this in the present study by examining the association between PEP-1-SIRT2 and the expression of MMP-1 and MMP-13 and type II collagen in rabbit articular chondrocytes. We found that PEP-1-SIRT2 increased MMP-1 and -13 expression in a dose- and time-dependent manner, as determined by western blotting. A similar trend in MMP-1 and -13 levels was observed in cultures during expansion to four passages. Pharmacological inhibition of MMP-1 and -13 blocked the PEP-1-SIRT2-induced decrease in type II collagen level. Phosphorylation of extracellular regulated kinase (ERK) was increased by PEP-1-SIRT2; however, treatment with the mitogen-activated protein kinase inhibitor PD98059 suppressed PEP-1-SIRT2-induced MMP-1 and -13 expression and dedifferentiation while restoring type II collagen expression in passage 2 cells. These results suggest that PEP-1-SIRT2 promotes MMP-induced dedifferentiation via ERK signaling in articular chondrocytes.

Effects of Ethanol on Brain Extracellular Matrix: Implications for Alcohol Use Disorder

The brain extracellular matrix (ECM) occupies the space between cells and is involved in cell-matrix and cell-cell adhesion. However, in addition to providing structural support to brain tissue, the ECM activates cell signaling and controls synaptic transmission. The expression and activity of brain ECM components are regulated by alcohol exposure. This review will discuss what is currently known about the effects of alcohol on the activity and expression of brain ECM components. An interpretation of how these changes might promote alcohol use disorder (AUD) will be also provided. Ethanol (EtOH) exposure decreases levels of structural proteins involved in the interstitial matrix and basement membrane, with a concomitant increase in proteolytic enzymes that degrade these components. In contrast, EtOH exposure generally increases perineuronal net components. Because the ECM has been shown to regulate both synaptic plasticity and behavioral responses to drugs of abuse, regulation of the brain ECM by alcohol may be relevant to the development of alcoholism. Although investigation of the function of brain ECM in alcohol abuse is still in early stages, a greater understanding of the interplay between ECM and alcohol might lead to novel therapeutic strategies for treating AUD.

Characteristics of Expression of Matrix Metalloproteinases (MMP-2 and MMP-9) in Glottic Squamous Cell Carcinoma and Benign Vocal Fold Lesions

Objectives

The aim of this study was to investigate expression profile of matrix metalloproteinases (MMP-2 and MMP-9) in glottic squamous cell carcinoma (SCC) and benign vocal fold lesions (BVFLs) and to correlate it with clinical and pathological features.

Methods

The immunohistochemical expression of MMP-2 and MMP-9 was investigated in specimens taken from 217 patients group, including vocal fold polyps (n=39), recurrent respiratory papillomatosis (n=30), laryngeal keratosis (n=36), glottic SCC (n=112), and the normal tissue of vocal fold (n=12, control group). The expression of MMP-2 and MMP-9, both in epithelium and stroma cells, was graded on a semiquantitative scale, ranging from 0 (no expression) to 18 points (high expression).

Results

Expressions of both, MMP-2 and MMP-9 were significantly higher in the glottic SCC group comparing with BVFL group. Significant higher expression of parenchymal MMP-2 (P<0.001) and stromal MMP-9 (P=0.01) was revealed in the group of moderate/poorly differentiated glottic SCC comparing with well differentiated glottic SCC group. Expression of stroma MMP-2 was found to be correlated with nodal metastasis (P=0.030). Expressions of both, MMP-2 and MMP-9 were not correlated with clinical stage, tumor T value, smoking, alcohol use, age in the glottic SSC patients group. The MMP-2 stroma value of 11.2 points was determined as the optimum point (limiting value) for separating BVFL and glottic SCC patient groups.

Conclusion

Our results suggest that expressions of both MMP-2 and MMP-9 are up-regulated already in the development of BVFL, the next determinant step is concerned with occurrence of malignization. Limiting value of stroma MMP-2 demonstrates prognostic importance of MMP-2 in glottic SCC carcinogenesis.

Anticedants and natural prevention of environmental toxicants induced accelerated aging of skin

Skin is frequently exposed to a variety of environmental and chemical agents that accelerate ageing. External stress such as UV radiations (UVR) and environmental pollutants majorly deteriorate the skin morphology, by activating certain intrinsic factors such as Reactive Oxygen Species (ROS) which trigger the activation of Matrix Metalloproteinases (MMPs) and inflammatory responses hence damaging the extracellular matrix (ECM) components. To counter this, an exogenous supply of anti-oxidants, is required since the endogenous anti-oxidant system cannot alone suffice the need. Bio-prospecting of natural resources for anti-oxidants has hence been intensified. Immense research is being carried out to identify potential plants with potent anti-oxidant activity against skin ageing. This review summarizes the major factors responsible for premature skin ageing and the plants being targeted to lessen the impact of those.

Effect of Smoking on Metalloproteinases (MMPs) Activity in Patients with Acute Myocardial Infarction (AMI)

INTRODUCTION

Many risk factors are involved in the course and pathogenesis of Acute Myocardial Infarction (AMI). Smoking can significantly increase the AMI mortality and morbidity. Matrix metalloproteinases (MMPs), a class of Zn containing enzymes, are involved in the erosion of the fibrous cap and rupture of the plaque which leads to AMI.

AIM

To evaluate the activity of MMP2 and MMP9 in AMI patients, with or without the habit of smoking.

MATERIALS AND METHODS

The study group consists of 300 AMI patients and 100 sex and age matched control subjects with and without the habit of smoking. MMP2 and MMP9 activities were measured in the blood samples of these patients and controls by sandwich enzyme immunoassay and the values were noted and compared.

RESULTS

Both MMP2 and MMP9 were found to be significantly elevated in all the AMI patients when compared to the normal controls subjects irrespective of the habit of smoking. However MMP9 showed a significant elevation when compared to MMP2 in patients with the habit of smoking.

CONCLUSION

The results of the present study shows increased concentration of both MMPs in AMI patients. However, concentration of MMP9 was found to be more in patients with the habit of smoking when compared to MMP2, indicating that smoking can increase the activity of MMP9 in these patients. Hence apart from producing the free radicals, the smoke can increase the activities of matrix degrading enzymes which in turn contribute to the vulnerability of plaque.

The significance of matrix metalloproteinases in the immunopathogenesis and treatment of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). The major pathological outcomes of the disease are the loss of blood-brain barrier (BBB) integrity and the development of reactive astrogliosis and MS plaque. For the disease to occur, the non-resident cells must enter into the immune-privileged CNS through a breach in the relatively impermeable BBB. It has been demonstrated that matrix metalloproteinases (MMPs) play an important role in the immunopathogenesis of MS, in part through the disruption of the BBB and the recruitment of inflammatory cells into the CNS. Moreover, MMPs can also enhance the cleavage of myelin basic protein (MBP) and the demyelination process. Regarding the growing data on the roles of MMPs and their tissue inhibitors (TIMPs) in the pathogenesis of MS, this review discusses the role of different types of MMPs, including MMP-2, -3, -7, -9, -12 and -25, in the immunopathogenesis and treatment of MS.

Mechanisms by which chronic ethanol feeding impairs the migratory capacity of cutaneous dendritic cells

BACKGROUND

Chronic alcoholism is associated with increased incidence and severity of skin infection. Cutaneous dendritic cells (CDCs) play a pivotal role in skin immunity, and chronic ethanol (EtOH) feeding in mice has been shown to inhibit CDC migration to skin-draining lymph nodes (dLNs) following epicutaneous sensitization. Because CDC subsets differentially initiate T-cell responses, it is important to determine how EtOH feeding affects migration of each subset and identify mechanisms responsible for observed defects.

METHODS

Mice received EtOH in the drinking water for ≥ 16 weeks. Baseline numbers of CDC subsets and their migration to the dLNs following fluorescein 5-isothiocyanate (FITC) sensitization were assessed by flow cytometry. Epidermal cell suspension and skin explant cultures were used to measure the impact of EtOH upon molecules that influence CDC migration. Cytokine arrays performed on explant culture supernatants assessed local production of inflammatory cytokines.

RESULTS

Chronic EtOH feeding reduced migration of all CDC subsets to the dLNs following FITC sensitization. Reduced migration of dermal-resident CDCs did not correspond with reduced baseline numbers of these cells. For Langerhans cells (LCs), EtOH-induced migratory dysfunction corresponded with delayed down-regulation of E-cadherin, chemokine receptor 1 (CCR1), and CCR6 and impaired up-regulation of matrix metalloproteinases (MMPs) 2 and 9. In skin explant assays, EtOH blunted CDC mobilization following stimulation with CCL21/CPG 1826. No alteration in CD54 or CCR7 expression was observed, but production of skin-derived tumor necrosis factor alpha (TNF-α) was reduced. Poor migratory responses in vitro could be improved by supplementing explant cultures from EtOH-fed mice with TNF-α.

CONCLUSIONS

Chronic EtOH consumption does not alter baseline dermal-resident CDC numbers. However, like LCs, migratory responsiveness of dermal CDCs was decreased following FITC sensitization. Inefficient down-regulation of both CCRs and adhesion molecules and the inability to up-regulate MMPs indicate that EtOH impedes LC acquisition of a promigratory phenotype. These defects, combined with improvement of the migratory defect with in vitro TNF-α replacement, demonstrate intrinsic as well as environmental contributions to defective CDC migration. These findings provide novel mechanisms to explain the observed increased incidence and severity of skin infections in chronic alcoholics.

S100 proteins as diagnostic and prognostic markers in colorectal and hepatocellular carcinoma

CONTEXT

Clinical and experimental studies have suggested a link between S100 gene ex-pression and neoplastic disorders, however, the molecular mechanisms of this associa-tion are not well understood. The aim of this review was to conduct a comprehensive literature search in order to understand the possible underlying molecular mechanisms of this association. We also discuss their application as diagnostic and prognostic mark-ers in colorectal and hepatocellular carcinoma.

EVIDENCE ACQUISITIONS

We searched Pubmed (NLM) and Web of Science (ISI Web of Knowledge).

RESULTS

S100 genes display a complex expression pattern in colorectal and hepatocel- lular carcinoma. They are expressed in tumor and/or tumor stroma cells, and they exert both pro- and antitumorigenic actions. In view of this complexity, it becomes clear that S100 proteins might act as both friend and foe. The biological role of the S100 genes is predicted to depend on the relative contributions of the different cell types at specific stages of tumor progression.

CONCLUSIONS

Further research is required in order to uncover the functional role of S100 genes in tumorigenesis. Answers to this issue are needed before we can more fully un-derstand the clinical relevance of S100 protein expression within epithelial tumors, with regard to their potential applicability as biomarkers for diagnosis and therapy decisions.

Review of matrix metalloproteinases' effect on the hybrid dentin bond layer stability and chlorhexidine clinical use to prevent bond failure

This review describes the relationship between dentin collagen hybrid bond layer degradation and the Matrix Metalloproteinases (MMPs) after their release by acid etch and rinse adhesives and self etching bonding adhesives that can reduce the bond stability over time. MMP-2, MMP-8 and MMP-9 are indicated as the active proteases that breakdown the collagen fibrils in the hybrid bond layer. Phosphoric acid in the acid etch and rinse bonding process and acid primers in the self etch process are implicated in the release of these proteases and their activation by several non-collagen proteins also released from dentin by the etching. MMPs are released in saliva by salivary glands, by cells in the gingival crevices to crevicular fluid and by pulpal odontoblasts cells to the dentinal fluids. These sources may affect the hybrid layer also. Evidence of the bond strength deterioration over time and the ability of Chlorhexidine to prevent bond deterioration by inhibiting MMP action are discussed. Dentin Bonding procedure utilizing Chlorhexidine for different application times and concentrations are being developed. The application of 2% Chlorhexidine to the phosphoric acid etch surface after rinsing off the acid is the only procedure that has been clinically tested for a longer period of time and shown to prevent bond strength degradation so far. The adoption of this procedure is recommended as means of improving bond stability at this time.

Differential expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in thioacetamide-induced chronic liver injury

Hepatic fibrogenesis, a complex process that involves a marked accumulation of extracellular matrix components, activation of cells capable of producing matrix materials, cytokine release, and tissue remodeling, is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The MMP-TIMP balance can regulate liver fibrogenesis. The aim of this study was to evaluate the expression patterns of MMPs and TIMPs during thioacetamide (TAA)-induced liver fibrogenesis. Chronic liver injury was induced with TAA (200 mg/kg i.p.) for 4 or 7 weeks in male Sprague-Dawley rats. Hepatic injury and fibrosis were assessed by hematoxylin-eosin (H&E) staining, and collagen deposition was confirmed by Sirius Red staining. The level of hepatic injury was quantified by serological analysis. The transcriptional and translational levels of alpha-smooth muscle actin (alpha-SMA), MMPs, and TIMPs in the liver were measured by Western blotting, RT-PCR, and immunohistochemistry. MMP, TIMP, and alpha-SMA were observed along fibrotic septa and portal spaces around the lobules. TAA treatment increased transcription of both MMPs and TIMPs, but only TIMPs showed increased translation. The dominant expression of TIMPs may regulate the function of MMPs to maintain liver fibrosis induced by TAA.