Inhibition Of MMPs Research Articles

Computational insights into the selectivity mechanism of APP-IP over matrix metalloproteinases

In this work, selectivity mechanism of APP-IP inhibitor (β-amyloid precursor protein-derived inhibitory peptide) over matrix metalloproteinases (MMPs including MMP-2, MMP-7, MMP-9 and MMP-14) was investigated by molecular modeling methods. Among MMPs, MMP-2 is the most favorable one for APP-IP interacting based on our calculations. The predicted binding affinities can give a good explanation of the activity difference of inhibitor APP-IP. In Comparison with MMP-2/APP-IP complex, the side chain of Tyr214(MMP-7) makes the binding pocket so shallow that the whole side chain of Tyr3(APP-IP) can not be fully embraced, thus unfavorable for the N-terminal of APP-IP binding to MMP-7. The poor selectivity of APP-IP toward MMP-9 is mainly related with the decrease of interaction between the APP-IP C-terminal and MMP-9 due to the bulky side chains of Pro193 and Gln199, which is in agreement with experiment. The mutations at residues P193A and Q199G of MMP-9 alternate the binding pattern of the C-terminal of APP-IP by forming two new hydrogen bonds and hydrophobic interactions with MMP-9. The mutants favor the binding affinity of MMP-9 largely. For MMP-14/APP-IP, the large steric effect of Phe204(MMP-14) and the weak contributions of the polar residues Asn231(MMP-14) and Thr190(MMP-14) could explain why MMP-14 is non-selective for APP-IP interacting. Here, the molecular modeling methods were successfully employed to explore the selective inhibitor of MMPs, and our work gives valuable information for future rational design of selective peptide inhibitors toward individual MMP.

Shark cartilage extract induces cytokines expression and release in endothelial cells and induces E-selectin, plasminogen and t-PA genes expression through an antioxidant-sensitive mechanism

Neovastat® is a standardized extract of marine cartilage, an avascular tissue, which contains many biologically active molecules and has multiple antiangiogenic properties. In addition to VEGFR2 and MMPs inhibition, shark cartilage extract (SCE) has recently been shown to induce tissue plasminogen activator gene (PLAT) expression in bovine endothelial cells in a TNF like manner, by inducing the typical mediators NF-κB and JNK. There is now compelling evidences that the NF-κB and JNK pathways are activated by cytokines induced generation of reactive oxygen species (ROS). We used macroarray genes expression analysis on human umbilical vein endothelial cells, to investigate if that mechanism could mediate the effect of SCE. Transcriptomic results showed that SCE induced expression of several cytokines. Their impact must be important, given that treatment of endothelial cells with the cytokine TNF-α was able to reproduce most of the effects of cartilage extract on genes expression. In addition, most of the genes, known to be inducible by NF-κB or JNK following cytokines stimulation, were less induced by SCE when endothelial cells were pretreated with the antioxidant N-Acetylcysteine (NAC), suggesting a role of ROS in endothelial cell activation by SCE. Finally, the possible effects of PLAT, PLG, SELE, IL8 and PRDX2 (those validated by q-PCR) on angiogenesis, will also be discussed.

Euterpe oleracea Mart.-derived polyphenols prevent endothelial dysfunction and vascular structural changes in renovascular hypertensive rats: role of oxidative stress

The consumption of polyphenol-rich foods is associated with a decreased risk of mortality from cardiovascular diseases. Previously, we have demonstrated that the stone of Euterpe oleracea Mart. (açaí) from the Amazon region exerts vasodilator and antioxidant actions. This study examined the effect of açaí stone extract (ASE) on the vascular functional and structural changes and oxidative stress associated with the two-kidney, one-clip (2K-1C) renovascular hypertension. 2K-1C and sham-operated rats were treated with ASE 200 mg/kg/day (or vehicle) for 40 days. Blood pressure was measured by tail plethysmography, and the vascular reactivity was evaluated in the rat isolated mesenteric arterial bed. Mesenteric protein expression of endothelial nitric oxide synthase (eNOS), superoxide dismutase 1 and 2 (SOD1 and SOD2), metalloproteinase 2 (MMP-2), and tissue inhibitor of MMPs (TIMP)-1 was assessed by Western blot; oxidative damage and antioxidant activity by spectrophotometry; MMP-2 levels by gelatin zymography; and structural changes by histological analysis. ASE prevented 2K-1C hypertension and the reduction of acetylcholine-induced vasodilation. The increased levels of malondialdehyde and carbonyl protein were reduced by ASE. SOD, catalase, and glutathione peroxidase activities and the expressions of SOD1 and SOD2, eNOS, and TIMP-1 were decreased in 2K-1C rats and recovered by ASE. In 2K-1C rats, ASE prevented vascular remodeling and the increased expression/levels of MMP-2. These findings indicate that ASE produces antihypertensive effect and prevents the endothelial dysfunction and vascular structural changes in 2K-1C hypertension, probably through mechanisms involving antioxidant effects, NOS activation, and inhibition of MMP-2 activation.

Specific matrix metalloproteinase 9 (MMP-9) haplotype affect the circulating MMP-9 levels in women with migraine

We investigated whether three relevant polymorphisms (C-1562T, microsatellite −90(CA)14–24, and Q279R) in the MMP-9 gene, or MMP-9 haplotypes, are associated with migraine and affect MMP-9 and tissue inhibitor of MMPs (TIMP)-1 levels in patients with migraine. We studied 102 healthy women (controls) and 187 women with migraine (141 without aura — MWA, and 46 with aura — MA). Patients with MWA had higher plasma MMP-9 concentrations than patients with MA. Patients with MA had the highest TIMP-1 and lowest MMP-9/TIMP-1 ratios. The MMP-9 “C L Q” haplotype was associated with higher plasma MMP-9 concentrations in migraine patients.

Inhibition of MMPs During Ovarian Recrudescence Reduces FOXL2 in Recrudescing Siberian Hamsters (Phodopus sungorus).

Inhibition of MMPs During Ovarian Recrudescence Reduces FOXL2 in Recrudescing Siberian Hamsters (Phodopus sungorus).

A novel set of β‐N‐biaryl ether sulfonamide hydroxamates as potential MMPs inhibitors: Molecular dynamics simulations and molecular properties evaluation

AbstractMatrix metalloproteinases (MMPs) constitute a family of zinc‐dependent proteases involved in the extracellular matrix degradation. MMP‐2 and MMP–9 are overexpressed in several human cancer types, including melanoma, thus the development of new compounds to inhibit MMPs' activity is desirable. Molecular dynamic simulation and molecular properties calculations were performed on a set of novel β‐N‐biaryl ether sulfonamide‐based hydroxamates, reported as MMP‐2 and MMP‐9 inhibitors, for providing data to develop an exploratory analysis. Thermodynamic, electronic, and steric descriptors have significantly discriminated highly active from moderately and less active inhibitors of MMP‐2 whereas apparent partition coefficient at pH 1.5 was also significant for the MMP‐9 data set. Compound 47 was considered an outlier in all analysis, indicating the presence of a bulky substituent group in R3 is crucial to this set of inhibitors for the establishment of molecular interactions with the S1 subsite of both enzymes, but there is a limit. © 2012 Wiley Periodicals, Inc.

The relationship between the MMP system, adrenoceptors and phosphoprotein phosphatases

The MMPs and their inhibitors [tissue inhibitor of MMPs (TIMPs)] form the mainstay of extracellular matrix homeostasis. They are expressed in response to numerous stimuli including cytokines and GPCR activation. This review highlights the importance of adrenoceptors and phosphoprotein phosphatases (PPP) in regulating MMPs in the cardiovascular system, which may help explain some of the beneficial effects of targeting the adrenoceptor system in tissue remodelling and will establish emerging crosstalk between these three systems. Although α- and β-adrenoceptor activation increases MMP but decreases TIMP expression, MMPs are implicated in the growth stimulatory effects of adrenoceptor activation through transactivation of epidermal growth factor receptor. Furthermore, they have recently been found to catalyse the proteolysis of β-adrenoceptors and modulate vascular tone. While the mechanisms underpinning these effects are not well defined, reversible protein phosphorylation by kinases and phosphatases may be key. In particular, PPP (Ser/Thr phosphatases) are not only critical in resensitization and internalization of adrenoceptors but also modulate MMP expression. The interrelationship is complex as isoprenaline (ISO) inhibits okadaic acid [phosphoprotein phosphatase type 1/phosphoprotein phosphatase type 2A (PP2A) inhibitor]-mediated MMP expression. While this may be simply due to its ability to transiently increase PP2A activity, there is evidence for MMP-9 that ISO prevents okadaic acid-mediated expression of MMP-9 through a β-arrestin, NF-κB-dependent pathway, which is abolished by knock-down of PP2A. It is essential that crosstalk between MMPs, adrenoceptors and PPP are investigated further as it will provide important insight into how adrenoceptors modulate cardiovascular remodelling, and may identify new targets for pharmacological manipulation of the MMP system.

Hyperhomocysteinemia decreases intestinal motility leading to constipation

Elevated levels of plasma homocysteine (Hcy) called hyperhomocysteinemia (HHcy) have been implicated in inflammation and remodeling in intestinal vasculature, and HHcy is also known to aggravate the pathogenesis of inflammatory bowel disease (IBD). Interestingly, colon is the pivotal site that regulates Hcy levels in the plasma. We hypothesize that HHcy decreases intestinal motility through matrix metalloproteinase-9 (MMP-9)-induced intestinal remodeling leading to constipation. To verify this hypothesis, we used C57BL/6J or wild-type (WT), cystathionine β-synthase (CBS(+/-)), MMP-9(-/-), and MMP-9(-/-) + Hcy mice. Intestinal motility was assessed by barium meal studies and daily feces output. Plasma Hcy levels were measured by HPLC. Expression of ICAM-1, inducible nitric oxide synthase, MMP-9, and tissue inhibitors of MMPs was studied by Western blot and immunohistochemistry. Reactive oxygen species (ROS) including super oxide were measured by the Invitrogen molecular probe method. Tissue nitric oxide levels were assessed by a commercially available kit. Plasma Hcy levels in the treated MMP-9 group mice were comparable to CBS(+/-) mice. Barium meal studies suggest that intestinal motility is significantly decreased in CBS(+/-) mice compared with other groups. Fecal output-to-body weight ratio was significantly reduced in CBS(+/-) mice compared with other groups. There was significant upregulation of MMP-9, iNOS, and ICAM-1 expression in the colon from CBS(+/-) mice compared with WT mice. Levels of ROS, superoxide, and inducible nitric oxide were elevated in the CBS(+/-) mice compared with other groups. Results suggest that HHcy decreases intestinal motility due to MMP-9-induced intestinal remodeling leading to constipation.

Potential biomarkers for disease activity in Takayasu's arteritis

Sun et al. recently reported matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6) as potential biomarkers for disease activity in Takayasu's arteritis (TA) in Chinese population [1]. Authors determined serum levels ofMMPs (MMP-3 and 9), tissue inhibitor ofMMPs (TIMP-1) and IL-6 in subjectswith TA and correlatedwith the disease activity of the disease. In a subgroup offifteenTA subjects they demonstrated that levels ofMMP-9 and IL-6 are able to predict the imagingoutcomeof thepatients with TA, but at the same time failed to notice any significant correlation between the pathological findings and the serum levels of MMP-9 and MMP-3 and IL-6. While reading this article, we found that the authors missed a few important studies to discuss in context to this particular field, where importance of IL-6 andMMPs-TIMP-1 has been established as potential biomarkers for this disease. Noris et al [2] in Italian population demonstrated a close relation of serum IL-6 with disease activity and suggested that it could contribute to vasculitic lesion in TA and could be relevant in the setting of therapeutic management of TA. In another study from Japan, Matsuyama et al [3] suggested that monitoring of circulating levels of MMP-2 as a helpful marker in diagnosing TA and those of MMP-3 and MMP-9 as disease activity markers might help provide adequate evaluation of treatment and guide therapeutic decision making for individual patients with TA. Our research group in India has also demonstrated importance of different MMPs (MMP-1, MMP-2, MMP-3, MMP-9 and TIMP-1) and their significant correlation with oxidative stress biomarkers (8-isoPGF2α and nitrite levels) in Takayasu's arteritis [4,5]. The etiopathogenesis of Takayasu's arteritis disease remains enigmatic, and various mechanisms such as post-infective, autoimmune, ethnic susceptibility and a genetic predisposition have been postulated [4,6]. As concluding remarks, we want to emphasize the fact that TA has been reported all over theworld with awide variation in its prevalence in different geographical regions. Moreover, it has been reported to cause different aortic lesion at different places in different countries [7]. Comparing and thoroughly analyzing the results from various studies reported worldwide will be of great help to provide a correct direction for future research on TA, as each and every researcher in this particular area is teaming to address the questionwhether any of thesemolecules can beused as amarker tomonitor the clinical course of the disease or to predict the disease exacerbations. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology [8].

Neutrophil-derived matrix metalloproteinase-9 is a potent activator of trypsinogen in acinar cells in acute pancreatitis

MMPs are generally considered to regulate degradation and remodeling of the ECM. Convincing data also implicate a role for MMPs in inflammatory conditions, such as AP, although the mechanisms are not known. The aim of this study was to define the role of MMPs in regulating activation of trypsinogen and tissue damage in AP, which was induced by infusion of taurocholate into the pancreatic duct in mice. A broad-spectrum MMP inhibitor (BB-94) and MMP-9 gene-deficient mice were used. Neutrophil secretions and rMMP-9 were used to stimulate trypsinogen activation in isolated acinar cells. Taurocholate challenge increased serum amylase, neutrophil infiltration, MIP-2 (CXCL2) formation, trypsinogen activation, and tissue damage in the pancreas. Treatment with the broad-spectrum inhibitor of MMPs, BB-94, markedly reduced activation of trypsinogen, levels of CXCL2, infiltration of neutrophils, and tissue damage in AP. Taurocholate challenge increased serum levels of MMP-9 but not MMP-2. Taurocholate-induced amylase levels, neutrophil accumulation, production of CXCL2, trypsinogen activation, and tissue damage in the pancreas were abolished in MMP-9-deficient mice. Moreover, secretions from activated neutrophils isolated from WT but not from MMP-9-deficient animals stimulated trypsinogen activation in acinar cells. Notably, rMMP-9 greatly enhanced activation of trypsinogen in acinar cells. These findings demonstrate that neutrophil-derived MMP-9 is a potent activator of trypsinogen in acinar cells and regulates pathological inflammation and tissue damage in AP.

Analysis of the serum biomarkers in human knee osteoarthritis

Analysis of the serum biomarkers in human knee osteoarthritis

Heparan Sulfate Chains of Syndecan-1 Regulate Ectodomain Shedding

Matrix metalloproteinases release intact syndecan-1 ectodomains from the cell surface giving rise to a soluble, shed form of the proteoglycan. Although it is known that shed syndecan-1 controls diverse pathophysiological responses in cancer, wound healing, inflammation, infection, and immunity, the mechanisms regulating shedding remain unclear. We have discovered that the heparan sulfate chains present on syndecan core proteins suppress shedding of the proteoglycan. Syndecan shedding is dramatically enhanced when the heparan sulfate chains are enzymatically degraded or absent from the core protein. Exogenous heparan sulfate or heparin does not inhibit shedding, indicating that heparan sulfate must be attached to the core protein to suppress shedding. Regulation of shedding by heparan sulfate occurs in multiple cell types, for both syndecan-1 and syndecan-4 and in murine and human syndecans. Mechanistically, the loss of heparan sulfate enhances the susceptibility of the core protein to proteolytic cleavage by matrix metalloproteinases. Enhanced shedding of syndecan-1 following loss of heparan sulfate is accompanied by a dramatic increase in core protein synthesis. This suggests that in response to an increase in the rate of shedding, cells attempt to maintain a significant level of syndecan-1 on the cell surface. Together these data indicate that the amount of heparan sulfate present on syndecan core proteins regulates both the rate of syndecan shedding and core protein synthesis. These findings assign new functions to heparan sulfate chains, thereby broadening our understanding of their physiological importance and implying that therapeutic inhibition of heparan sulfate degradation could impact the progression of some diseases.

Abstract 3630: Function-Blocking Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) Antibody Injection is Neuroprotective after Focal Cerebral Ischemia

Introduction: Extracellular metalloproteinase inducer, EMMPRIN, is a cell surface glycoprotein found on endothelial cells and astrocytes and has a key role in the expression of MMPs. It was reported that EMMPRIN expression is upregulated in a mouse model of permanent cerebral ischemia and that EMMPRIN co-localized with MMP-9 in infarcted tissue. There is evidence to support that elevation of MMP activity contributes to injury after stroke and that inhibition of MMPs can reduce infarct volume in rats. In this study we hypothesized that inhibition of EMMPRIN with a function-blocking antibody would reduce infarct volume and improve stroke outcome in mice subjected to a MCAO stroke through reduction in MMP activation. Methods: Transient 90-minute middle cerebral artery occlusion (MCAO) was performed on male wild-type mice treated with vehicle, rat IgG2a (eBioscience), or with function blocking anti-EMMPRIN antibody (eBioscience) injected via tail vein. A single injection was given at stroke onset. Mice were sacrificed at 48 hours post reperfusion. Brains were harvested for TTC staining (n=4/group; significance p<0.05). A second cohort of vehicle and drug treated mice (n=3 vehicle, n=7 drug) were subjected to transient 90-minute middle cerebral artery occlusion and were sacrificed at 72 hours. These mice were given the initial dose at stroke onset and an additional dose at 48 hours. Both cohorts were subjected to behavioral analysis using a modified 4 point scoring system. Results: Mice treated with the function blocking EMMPRIN antibody had smaller infarct volumes when compared with vehicle treated animals. This reduction in damaged tissue was consistent in the cortex, striatum and total hemisphere of each group. Drug treated mice had improved behavior scores when compared to vehicle treated mice at both the 48hr and 72hrs time points. Furthermore, vehicle treated mice had higher mortality rates (20% at 48hrs and 66% at 72hrs) than drug mice (0% at 48hrs and 14% at 72hrs) at both time points. Discussion: Animals treated with a function-blocking antibody to EMMPRIN presented with less infarct volume and better behavior scores than similar animals treated with vehicle. Thus, EMMPRIN inhibition is neuroprotective. Considering monoclonal antibody therapy has been successful in the treatment of other diseases, this data suggests that inhibition of EMMPRIN via administration of an antibody could have therapeutic potential for stroke patients.

Effects of an oral MMP-9 and -12 inhibitor, AZD1236, on biomarkers in moderate/severe COPD: A randomised controlled trial

BackgroundThere is a pressing need for new forms of treatment for COPD. Based on the known pathophysiology of COPD, inhibition of matrix metalloproteinases is a theoretically promising approach. This Phase IIa study evaluated the effects of AZD1236, a selective MMP-9 and MMP-12 inhibitor, on the biomarkers of inflammation and emphysematous lung tissue degradation in patients with moderate-to-severe COPD. MethodsThis was a multinational, randomized, double-blind, placebo-controlled signal-searching study conducted in men and women aged ≥40 years with stable moderate-to-severe COPD. After a 2–6-week period to eliminate any remaining effects of previous medication, 55 patients received oral AZD1236 75 mg or matching placebo twice daily for 6 weeks. Differential cell count and TNF-α levels in induced sputum and 24-h urinary desmosine excretion were the main study variables, but a range of exploratory biomarkers was also assessed in induced sputum, blood and urine. Secondary variables included lung function and patient-recorded Clinical COPD Questionnaire (CCQ) responses and diary records of symptoms, adverse events, use of rescue medication and AZD1236 plasma concentrations. ResultsThe majority of variables showed little change compared to placebo although there was a possible, but not statistically significant reduction in urinary desmosine excretion and reductions in the number and percentage of lymphocytes in sputum and blood with AZD1236. No effect was seen on clinical parameters after 6 weeks of treatment. The proportion of patients experiencing adverse events was similar in both treatment groups. ConclusionsAZD1236 dosed orally at 75 mg twice daily was generally well tolerated over 6 weeks in patients with moderate-to-severe COPD. No clinical efficacy of AZD1236 was demonstrated in this short-term signal-searching study, although possible evidence of an impact on desmosine may suggest the potential value of selective inhibitors of MMPs in the treatment of COPD in longer term trials.

Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion

Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs) related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA) increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion.

The Relationship between Tumor Sialic Acids and Neoplasm Metastasis and as a Drug Target

Cancer is one of the high-mortality diseases, which causes the annual deaths listing among the top 5 mortality in almost all countries. Unlike cardiovascular diseases, the treatment beneficiary for cancers especially for epithelial carcinoma has been improving slightly over the past several decades [1-3]. Neoplasm metastasis is one of the fatalist characters responsible for these unsatisfactory of therapies and more than 60% cancer deaths and can be hopefully only controlled by drugs. Paradoxically to our efforts and expectations, except some antibodies, no obvious improvements and therapeutic benefits by conventional antimetastatic drugs (usually antivascular agents or MMPs inhibitors) have been achieved until now. Therapeutic benefits in late-staged or aged cancer patients are especially poor and useless [1-3]. Clinical anticancer drug therapies currently in use have been mainly focusing on primary tumor growth rather than specifically targeting pathologic courses of metastases relevantly. Finding important drugs targeting specifically to neoplasm metastases is essential and indispensable [4-7]. It nevertheless needs changing our focus from targeting vascularity and MMPs into more metastatic-relating molecules.

TIMPs and MMPs expression in nasal polyps

Nasal polyposis is a chronic inflammatory disease characterized by inflammatory invasion of nasal mucosa, changes in cells differentiation, thickness reduction and remodelling of basal membrane, hyperplasia of mucous glands, extracellular matrix deposition. MMPs shown a proteolytic activities towards several components of extracellular matrix, play an important role in connective tissue remodeling. MMPs are a proteins family including 25 isoforms of Ca2+ and Zn 2+ dependant endopeptidases. MMPs are inactive and can be activated by proteases removing some amino acids. Tissue inhibitors of matrix metalloproteinases (TIMPs) are natural inhibitors of MMPs. TIMPs inhibiting MMPs activation by MMPs/TIMPs complexes: TIMP-1 and TIMP-2 are soluble protein, inhibiting mainly MMP-9 and 2, TIMP-3 is mainly associated to ECM. The balance between MMP/TIMP is very critical in matrix remodeling and various physiological processes. Imbalances between these enzymes and inhibitors may cause pathological processes such as chronic inflammation, degenerative disease and tumour invasion. In our study we aimed at demonstrating MMP/TIMP imbalance in nasal polyposis, similar to other pathological processes. The complex structure of polyp formation is still unknown. In this research nasal polyp specimens were obtained from 96 patients with nasal polyposis during endoscopic sinus surgery. Bullous middle turbinates with normal appearing mucosa of fifteen non-smoker patients free of any allergic or infectious diseases of nose or sinuses were used as controls. Patients were divided in three groups: patients of group A have morphostructural polyps; patients of group B have syndromic polyps; patients of group C have allergic polyps. We investigate MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2, TIMP-3 expression in our specimens using immunoistochemistry, Western Blot Analysis and RT-PCR methods. Our results shown a interesting relashionship between MMPs/TIMPs imbalance and nasal polyps formation.

Biochemical comparison of osteoarthritic knees with and without effusion

BackgroundSeveral symptom-relieving interventions have been shown to be efficacious among osteoarthritis (OA) patients with knee effusion; however, not every symptomatic knee OA patient has clinical effusion. Results may be over-generalized since it is unclear if effused knees represent a unique pathological condition or subset compared to knees without effusion. The primary purpose of this study was to determine if biochemical differences existed between OA knees with and without effusion.MethodsThe present cross-sectional study consisted of 22 volunteers (11 with knee effusion, 11 without knee effusion) with confirmed late-stage radiographic knee OA (Kellgren-Lawrence score ≥ 3). Synovial fluid samples were collected and analyzed using a custom multiplex enzyme-linked immunosorbent assay to determine eight specific biomarker concentrations (e.g., catabolic, anabolic).ResultsMatrix metalloproteinase (MMP)-3, tissue inhibitor of MMPs (TIMP)-1, TIMP-2, and interleukin-10 were significantly higher in the knees with effusion than in the knees without effusion.ConclusionsThe biochemical differences that existed between knees with and without effusion provide support that OA subsets may exist, characterized by distinct biochemical characteristics and clinical findings (e.g., effusion).

Removal of the basement membrane enhances corneal wound healing

Recurrent corneal erosions are painful and put patients’ vision at risk. Treatment typically begins with debridement of the area around the erosion site followed by more aggressive treatments. An in vivo mouse model has been developed that reproducibly induces recurrent epithelial erosions in wild-type mice spontaneously within two weeks after a single 1.5 mm corneal debridement wound created using a dulled-blade. This study was conducted to determine whether 1) inhibiting MMP9 function during healing after dulled-blade wounding impacts erosion development and 2) wounds made with a rotating-burr heal without erosions. Oral or topical inhibition of MMPs after dulled-blade wounding does not improve healing. Wounds made by rotating-burr heal with significantly fewer erosions than dulled-blade wounds. The localization of MMP9, β4 integrin and basement membrane proteins (LN332 and type VII collagen), immune cell influx, and reinnervation of the corneal nerves were compared after both wound types. Rotating-burr wounds remove the anterior basement membrane centrally but not at the periphery near the wound margin, induce more apoptosis of corneal stromal cells, and damage more stromal nerve fibers. Despite the fact that rotating-burr wounds do more damage to the cornea, fewer immune cells are recruited and significantly more wounds resolve completely.

Abstract C1: The myosin II inhibitor blebbistatin more potently inhibits 3-D cell invasion than 2-D cell migration in a human metastatic tumor cell

Abstract The acquired ability for tumor cells to migrate and invade through the extracellular matrix within the tumor microenvironment has long been accepted as a hallmark of metastatic potential. Numerous signal transduction pathways and a wide variety of protein classes have been implicated as important players in cell migration and/or invasion. For example, matrix-metalloproteinases (MMPs) have been implicated in the degradation of the basal lamina that is required for the movement of cells through the matrix. Likewise, the MEK/ERK pathway has been implicated in upregulated expression of MMPs in tumor cells. Furthermore, recent evidence has indicated that myosin II also plays a major role in tumor cell invasion. However, the relative contribution of myosin II in cell migration compared to cell invasion remains unclear. In this study we use the myosin II inhibitor, blebbistatin, to concurrently investigate the relative contribution of myosin II to both 2D migration and 3D invasion of human fibrosarcoma derived HT 1080 cells through collagen I and Matrigel matrices. To accomplish this, we utilized a novel assay strategy using a live-cell imaging system, the IncuCyte-FLR, to simultaneously measure migration and invasion of non-labeled cells in a 96-well plate format. Following assay initiation, images of all 96-wells were obtained every three hours until assay completion. Each image was automatically analyzed using phase contrast image based algorithms. Our results indicate that blebbistatin is approximately one order of magnitude more potent in its ability to inhibit cell invasion through both collagen I and Matrigel matrices compared to its ability to inhibit 2D cell migration (e.g. IC50 value for invasion is 5μM compared to the IC50 value for migration, >90μM). Similar, less pronounced results were also observed when human breast adenocarcinoma derived MDA-MB-231 cells were identically evaluated. These results suggest that the myosin II contractile machinery is more heavily taxed during the process of invasion compared to migration in two distinct metastatic cell types. In addition to the role of myosin II, we extended our study to investigate the relative contribution of both MMPs and the MEK/ERK pathway to cell migration and invasion using the inhibitors GM6001 and U0126, respectively. Interestingly, with both inhibitors, we observed minimal effects on cell migration, but significant inhibition of cell invasion through collagen I. In addition, whereas inhibition of myosin II had a significant, immediate effect on invasion, broad inhibition of several MMPs and inhibition of the MEK/ERK pathway did not significantly show an effect until 5, or 10 hours after assay initiation, respectively. These time points are often well past the end point of other commonly used approaches to measure cell invasion. We also found that the results of this assay were dependent both on cell density as well as matrix concentration illustrating the importance of assay optimization. Using this novel, kinetic approach, the results of this study further clarify a more significant role for myosin II in cell invasion when compared to cell migration. We also provide additional evidence that MMPs and MAPK signaling pathways are significantly involved in the process of cell invasion. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C1.