Tissue Inhibitor Of Metalloproteinases-2 Research Articles

Biology of Tissue Inhibitor of Metalloproteinase 3 (TIMP3), and Its Therapeutic Implications in Cardiovascular Pathology.

Tissue inhibitor of metalloproteinase 3 (TIMP3) is unique among the four TIMPs due to its extracellular matrix (ECM)-binding property and broad range of inhibitory substrates that includes matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), and ADAM with thrombospondin motifs (ADAMTSs). In addition to its metalloproteinase-inhibitory function, TIMP3 can interact with proteins in the extracellular space resulting in its multifarious functions. TIMP3 mRNA has a long 3’ untranslated region (UTR) which is a target for numerous microRNAs. TIMP3 levels are reduced in various cardiovascular diseases, and studies have shown that TIMP3 replenishment ameliorates the disease, suggesting a therapeutic potential for TIMP3 in cardiovascular diseases. While significant efforts have been made in identifying the effector targets of TIMP3, the regulatory mechanism for the expression of this multi-functional TIMP has been less explored. Here, we provide an overview of TIMP3 gene structure, transcriptional and post-transcriptional regulators (transcription factors and microRNAs), protein structure and partners, its role in cardiovascular pathology and its application as therapy, while also drawing reference from TIMP3 function in other diseases.

Aggrecanase-selective tissue inhibitor of metalloproteinase-3 (TIMP3) protects articular cartilage in a surgical mouse model of osteoarthritis

A key feature of osteoarthritis is the gradual loss of articular cartilage and bone deformation, resulting in the impairment of joint function. The primary cause of cartilage destruction is considered to be the presence of elevated proteases, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs). However, clinically tested global MMP inhibitors have low efficacy that may be due to their lack of selectivity. We previously demonstrated in vitro that a variant of tissue inhibitor of metalloproteinase-3 ([-1A]TIMP3) inhibits ADAMTSs but not MMPs. In this study, we tested whether the selectivity of [-1A]TIMP3 is beneficial compared with that of the wild-type TIMP3 in preventing or delaying the onset of the degenerative effects in a mouse model of osteoarthritis. We generated transgenic mice that overexpressed TIMP3 or [-1A]TIMP3 driven by a chondrocyte-specific type II collagen promoter. TIMP3 transgenic mice showed compromised bone integrity as opposed to [-1A]TIMP3 mice. After surgically induced joint instability, TIMP3 overexpression proved to be less protective in cartilage destruction than [-1A]TIMP3 at late stages of OA. The selective inhibition of ADAMTSs provides the possibility of modifying TIMP3 to specifically target a class of cartilage-degrading proteinases and to minimize adverse effects on bone and possibly other tissues.

Effects of Different Doses of Remote Ischemic Preconditioning on Kidney Damage Among Patients Undergoing Cardiac Surgery: A Single-Center Mechanistic Randomized Controlled Trial.

We have previously shown that remote ischemic preconditioning reduces acute kidney injury (acute kidney injury) in high-risk patients undergoing cardiopulmonary bypass and that the protective effect is confined to patients who exhibit an increased urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 in response to remote ischemic preconditioning. The purpose of this study was to determine the optimal intensity of remote ischemic preconditioning to induce required [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] changes and further explore mechanisms of remote ischemic preconditioning. Observational and randomized controlled, double-blind clinical trial. University Hospital of Muenster, Germany. High-risk patients undergoing cardiac surgery as defined by the Cleveland Clinic Foundation Score. In the interventional part, patients were randomized to receive either one of four different remote ischemic preconditioning doses (3 × 5 min, 3 × 7 min, 3 × 10 min remote ischemic preconditioning, or 3 × 5 min remote ischemic preconditioning + 2 × 10 min remote ischemic preconditioning in nonresponders) or sham-remote ischemic preconditioning (control). The primary endpoint of the interventional part was change in urinary [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] between pre- and postintervention. To examine secondary objectives including acute kidney injury incidence, we included an observational cohort. A total of 180 patients were included in the trial (n = 80 observational and n = 100 randomized controlled part [20 patients/group]). The mean age was 69.3 years (10.5 yr), 119 were men (66.1%). Absolute changes in [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] were significantly higher in all remote ischemic preconditioning groups when compared with controls (p < 0.01). Although we did not observe a dose-response relationship on absolute changes in [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] across the four different remote ischemic preconditioning groups, in the 15 patients failing to respond to the lowest dose, nine (60%) responded to a subsequent treatment at a higher intensity. Compared with controls, fewer patients receiving remote ischemic preconditioning developed acute kidney injury within 72 hours after surgery as defined by both Kidney Disease: Improving Global Outcomes criteria (30/80 [37.5%] vs 61/100 [61.0%]; p = 0.003). All doses of remote ischemic preconditioning significantly increased [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] and significantly decreased acute kidney injury compared with controls. High-dose remote ischemic preconditioning could stimulate [tissue inhibitor of metalloproteinases-2]*[insulin-like growth factor-binding protein 7] increases in patients refractory to low-dose remote ischemic preconditioning.

Inhibiting Matrix Metalloproteinase-2 Activation by Perturbing Protein-Protein Interactions Using a Cyclic Peptide.

We report on a cyclic peptide that inhibits matrix metalloproteinase-2 (MMP2) activation with a low-nM-level potency. This inhibitor specifically binds to the D570-A583 epitope on proMMP2 and interferes with the protein-protein interaction (PPI) between proMMP2 and tissue inhibitor of metalloproteinases-2 (TIMP2), thereby preventing the TIMP2-assisted proMMP2 activation process. We developed this cyclic peptide inhibitor through an epitope-targeted library screening process and validated its binding to proMMP2. Using a human melanoma cell line, we demonstrated the cyclic peptide's ability to modulate cellular MMP2 activities and inhibit cell migration. These results provide the first successful example of targeting the PPI between proMMP2 and TIMP2, confirming the feasibility of an MMP2 inhibition strategy that has been sought after for 2 decades.

P0745URINE TIMP-2 AND IGFBP-7- NEW BIOMARKERS OF KIDNEY INJURY IN MULTIPLE MYELOMA PATIENTS

Abstract Background and Aims Urine tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) seem to be novel kidney injury related biomarkers, especially in tubular cells damage. Free light chains (FLCs) are associated with renal failure in multiple myeloma (MM) and appear to have a prognostic value and indicate stages in MM. The aim of the study was to investigate the correlation between new biomarkers and acclaimed parameters of renal failure and markers of MM stages and prognosis. Method The study included 124 patients with MM in the mean age of 66 +/- 10 years, with median time from MM diagnosis of 30 (lower; upper quartile 14; 63) months. There were 7(6%) patients with smoldering MM, 80(65%) with ISS stage 1, 22 (18%)with stage 2 and 15 (12%) with stage 3 MM. Mean eGFR was 71 +/- 25 ml/min/1.73 m2 and 30 (24%) patients had eGFR &amp;lt;60 ml/min/1.73 m2. The examined parameters included creatinine, urine NGAL, urine and serum cystatin-C, urine and serum FLC kappa and lambda, serum monoclonal protein, IGFBP-7 and TIMP-2 in serum and urine, WBC count, IL-6, NT-proBNP, serum albumin and β2-microglobulin. IGFBP-7 and TIMP-2 in serum were measured in a subgroup of 73 patients, including 26 (36%) with eGFR &amp;lt;60 ml/min/1.73 m2. The association between between these parameters were determined by multivariate stepwise regression analysis. The p-value &amp;lt;0.05 was considered statistically significant. Results Except for urine cystatin C and urine TIMP-2, all the studied markers were higher among patients with eGFR &amp;lt;60 ml/min/1.73m2: urine NGAL: 23.3 (9.2; 68.4) vs. 7.8 (3.9; 16.8) ng/ml; p&amp;lt;0.001; urine IGFBP-7: ; serum IGFBP-7: 86.2 (29.3; 125.0) vs. 33.7 (13.2; 61.5) ng/ml; p=0.003; and serum TIMP-2: 628 (498; 663) vs. 431 (360; 614) ng/ml; p=0.011, respectively. Serum and urine IGFBP-7 and urine NGAL were also higher among patients with ISS grade 3 comparing to the rest of the group (p=0.008, p&amp;lt;0.001 and p=0.033, respectively). Patients with smoldering myeloma did not differ from those with symptomatic disease. No differences in studied markers were observed between patients with newly diagnosed MM in comparison to those who had been treated with one or more schemes. Only urinary IGFBP-7 differed between patients who were on treatment at the time of samples’ collection (median ng/ml) in comparison to untreated (median ng/ml; p=0.009). No differences in TIMP-2 and IGFBP-7 levels in patients divided according to MM state were observed (remission vs stable vs progressive disease). In whole studied group, urinary markers of tubular injury were interrelated: cystatin C correlated positively with NGAL monomer (R=0.22; p=0.016), IGFBP-7 (R=0.26; p=0.004) and TIMP-2 (R=0.22; p=0.016), NGAL correlated positively with IGFBP-7 (R=0.39; p&amp;lt;0.001) and TIMP-2 (R=0.25; p=0.005), and IGFBP-7 correlated positively with TIMP-2 (R=0.31; p&amp;lt;0.001). In multiple linear regression, the negative correlation between urinary IGFBP-7 and eGFR was independent of other studied urinary markers of tubular injury. However, after adjustment for confounders (age, smoldering versus symptomatic MM, ISS, LDH, remission versus stable or progressive disease, and the concentrations of involved urine light chains), only urinary NGAL was independently associated with eGFR. Conclusion Urine TIMP-2 and IGFBP-7 may be useful in investigating tubular renal damage in patients with chronic kidney injury among patients with MM. This can lead to noninvasive biomarker-targeted diagnostic interventions and contribute to early beginning of treatment that may improve life expectancy quality of life in MM.

Urine cell cycle arrest biomarkers distinguish poorly between transient and persistent AKI in early septic shock: a prospective, multicenter study

BackgroundThe urine biomarkers tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) have been validated for predicting and stratifying AKI. In this study, we analyzed the utility of these biomarkers for distinguishing between transient and persistent AKI in the early phase of septic shock.MethodsWe performed a prospective, multicenter study in 11 French ICUs. Patients presenting septic shock, with the development of AKI within the first 6 h, were included. Urine [TIMP-2]*[IGFBP7] was determined at inclusion (0 h), 6 h, 12 h, and 24 h. AKI was considered transient if it resolved within 3 days. Discriminative power was evaluated by receiver operating characteristic (ROC) curve analysis.ResultsWe included 184 patients, within a median [IQR] time of 1.0 [0.0–3.0] h after norepinephrine (NE) initiation; 100 (54%) patients presented transient and 84 (46%) presented persistent AKI. Median [IQR] baseline urine [TIMP-2]*[IGFBP7] was higher in the persistent AKI group (2.21 [0.81–4.90] (ng/ml)2/1000) than in the transient AKI group (0.75 [0.20–2.12] (ng/ml)2/1000; p < 0.001). Baseline urine [TIMP-2]*[IGFBP7] was poorly discriminant, with an AUROC [95% CI] of 0.67 [0.59–0.73]. The clinical prediction model combining baseline serum creatinine concentration, baseline urine output, baseline NE dose, and baseline extrarenal SOFA performed well for the prediction of persistent AKI, with an AUROC [95% CI] of 0.81 [0.74–0.86]. The addition of urine [TIMP-2]*[IGFBP7] to this model did not improve the predictive performance.ConclusionsUrine [TIMP-2]*[IGFBP7] measurements in the early phase of septic shock discriminate poorly between transient and persistent AKI and do not improve clinical prediction over that achieved with the usual variables.Trial registrationNCT02812784

P0624INCREASED URINARY BIOMARKERS OF KIDNEY INJURY IN PATIENTS AFTER ALLOGENETICHEMATOPOETIC STEM CELL TRANSPLANTATION REFLECT KIDNEY DAMAGE EVEN IN NORMALN KIDNEY FUNCTION

Abstract Background and Aims Chronic kidney disease (CKD) and acute kidney injury (AKI) are common complications of hematopoietic stem cell transplantation (HSCT) associated with increased morbidity and mortality. On the other hand, presence of CKD is often used as an exclusion criterion when selecting patients who undergo HSCT, especially when fludarabine in conditioning or GVHD prophylaxis with a calcineurin inhibitor is contemplated. There is also no threshold (CKD stage, level of serum creatinine etc) below which patients should not undergo allogeneic HSCT. Kidney function in patients undergoing HSCT is frequently worsened by previous chemotherapy and exposure to a variety of nephrotoxic drugs. Several biomarkers were widely investigated for early diagnosis of acute kidney injury, including neutrophil gelatinase associated lipocalin (NGAL), urinary liver-type fatty acid-binding protein (uL-FABP) and others, however, in patients undergoing HSCT, the published literature is exceptionally scarce. A few studies with inconclusive results stress the knowledge gap and need for further research. The aim of the study was to assess biomarkers of kidney injury in patients at least 3 months after HSCT (to avoid the effect of calcineurin inhibitors) under ambulatory care of Hematology, Oncology and Internal Medicine Department, University Teaching Hospital. Method We studied 80 prevalent patients after allogeneic HSCT and 32 healthy volunteers to obtained normal ranges for biomarkers. In this cross-sectional study following biomarkers of kidney injury in urine were evaluated: IGFBP-7/TIMP2 (insulin growth factor binding protein-7/, tissue inhibitor of metalloproteinases-2), netrin-1, semaphorin A2 using commercially available assays. Results All the biomarkers studied were significantly higher in patients after HSCT when compared to healthy volunteers (all p&amp;lt;0.001). When we divided patients according to kidney function (below and over 60 ml./min/1.72m2), we found that only concentration of IGFBP-7 was significantly higher in 23 patients with CKD stage 3 (i.e. eGFR below 60ml.min/1.72m2) relative to patients with eGFR over 60 ml.min.1.72m2. All biomarkers in both subgroups of patients with eGFR below and over 60 ml./min/1.72m2 were significantly higher relative to healthy volunteers. In univariate correlations sempahorinA2 was related to netrin 1 (r=0.47, p&amp;lt;0.001), IGFBP7 (r=0.35, p&amp;lt;0.01), TIMP2 (r=0.32, p&amp;lt;0.01), whereas IGFBP7 was positively related to serum creatinine (r=0.38, p&amp;lt;0.001) and inversely to eGFR (r=-0.36, p&amp;lt;0.001). Conclusion Concluding, patients after allogeneic HSCT despite normal or near normal kidney function show evidence of kidney injury, which might be due to comorbidities, previous chemotherapy, conditioning regimen,complement activation, calcineurin therapy after HSCT, other possible nephrotoxic drugs etc. Nephroprotective strategies are to be considered as chronic kidney disease is a risk factor for increased morbidity and mortality in this vulnerable population.

Impact of thermal stress exposure on seminal quality, antioxidant defence system, TNF-α and TIMP-3 in Ossimi ram.

Heat stress (HS) occupies huge importance nowadays as it leads to severe economic losses especially in livestock. Preserving sheep against HS is one of the governmental scopes where it represents huge percentage of global ruminant. The present research was conducted to study semen quality, some stress and inflammatory markers in Ossimi rams under both hot and mild climatic conditions. The current study was conducted on selected 46 ram samples divided into two groups during summer and winter. Semen analysis, testosterone (TES), cortisol (COR) and blood glucose (BG) levels, and lipid and protein profiles were done. Concentrations of tumour necrosis factor alpha (TNF-α), tissue inhibitor of metalloproteinase-3 (TIMP-3), nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) and specific activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were assessed. The results in summer compared to winter revealed significant elevation of total defects and number of dead sperms; however, there was reduction in sperm total motility and concentration and external epididymal tail duct diameter. Histological study of epididymal tail lumen exhibited azoospermia. Further, TES, TIMP-3 and GSH levels were decreased and COR, TNF-α, NO and MDA were raised. Specific activities of GPx and SOD were also declined. Additionally, there was a significant increase in concentrations of BG and lipid profiles except high-density lipoprotein. Our data concluded that there were new insights into TNF-α and TIMP-3 as biomarkers can be used in diagnosis of sheep suffering from HS, but further studies are recommended to do in future work about such aspect.

MiR-23b Promotes the Migration of Keratinocytes Through Downregulating TIMP3

BackgroundWound healing is a complex process aiming at repairing the damaged skin. MiR-23b has been reported to be upregulated during wound healing. In this study, we intended to explore the working mechanism of miR-23b during wound healing. MethodsQuantitative real-time polymerase chain reaction was performed to detect the enrichment of miR-23b and tissue inhibitor of metalloproteinase-3 (TIMP3) in HaCaT cells. Scratch wound assay was carried out to measure the migration of HaCaT cells. The target of miR-23b was predicted by microT-CDS software, and the combination was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay. The abundance of TIMP3 protein was detected by Western blot assay. ResultsThe abundance of miR-23b was positively related to the concentration and time of transforming growth factor β1 treatment in HaCaT cells. MiR-23b promoted the migration of keratinocytes. TIMP3 was a direct target of miR-23b and was negatively regulated by miR-23b. TIMP3 inhibited the migration of keratinocytes. MiR-23b accelerated the migration of keratinocytes by downregulating the abundance of TIMP3. ConclusionsMiR-23b promoted the migration of keratinocytes partly through reducing the enrichment of TIMP3. MiR-23b might be a promising target for the treatment of wound healing–associated diseases.

MiR-770-5p facilitates podocyte apoptosis and inflammation in diabetic nephropathy by targeting TIMP3.

Objective: Diabetic nephropathy (DN) is one of the most severe and frequent diabetic complications. MicroRNAs (miRNAs) have been reported to play a vital role in DN pathogenesis. The present study aimed to investigate the molecular mechanism of miR-770-5p in DN.Methods: Podocyte injury model was established by treating mouse podocytes with high glucose (HG, 33 mM) for 24 h. The levels of miR-770-5p and TIMP3 were examined in kidney tissues and podocytes using quantitative real-time PCR (qRT-PCR). Flow cytometry analysis was applied to detect apoptosis in podocytes. Western blot assay was used to measure the protein levels of B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax) and tissue inhibitors of metalloproteinase 3 (TIMP3). Enzyme-linked immunosorbent assay (ELISA) was conducted to measure the levels of inflammatory factors. The interaction between miR-770-5p and TIMP3 was determined by MicroT-CDS and luciferase reporter assay.Results: MiR-770-5p was up-regulated and TIMP3 was down-regulated in DN kidney tissues and HG-stimulated podocytes. Depletion of miR-770-5p suppressed cell apoptosis and the release of pro-inflammatory factors in HG-treated podocytes. Additionally, TIMP3 was a target of miR-770-5p in HG-treated podocytes. TIMP3 inhibited cell apoptosis and inflammation in HG-treated podocytes. Moreover, TIMP3 knockdown alleviated the inhibitory effect of miR-770-5p silencing on podocyte apoptosis and inflammatory response.Conclusion: Knockdown of miR-770-5p suppressed podocyte apoptosis and inflammatory response by targeting TIMP3 in HG-treated podocytes, indicating that miR-770-5p may be a potential therapeutic target for DN therapy.

Is Dietary 2-Oxoglutaric Acid Effective in Accelerating Bone Growth and Development in Experimentally-Induced Intrauterine Growth Retarded Gilts?

Simple SummaryIntrauterine growth restriction (IUGR) is a significant health issue that not only affects infant mortality or term body weight, but may also predispose individuals to a reduced rate of weight gain and the development of numerous diseases later in life. In livestock production, growth restricted (IUGR) animals require more time to reach slaughter weight. In this study, we examined the effects of long-term administration of 2-oxoglutaric acid (2-Ox) to experimentally-induced intrauterine growth retarded gilts.In this study, the effect of long-term 2-oxoglutaric acid (2-Ox) supplementation to experimentally-induced intrauterine growth retarded gilts was examined. Sows were treated with synthetic glucocorticoid (dexamethasone) every second day, during the last 45 days of pregnancy, at a dose of 0.03 mg/kg b.w. At birth, the gilts were randomly divided into two groups: unsupplemented and supplemented with 2-Ox for nine months (0.4 g/kg body weight/day). Oral supplementation of 2-Ox to experimentally-induced intrauterine growth retarded gilts increased body weight at weaning as well as final body weight at the age of nine months, and showed a regenerative effect on bone mineralization and morphology of trabeculae and articular cartilage. The positive effects on bone structure were attributed to the 2-Ox-induced alterations in bone metabolism, as evidenced by the changes in the expression of proteins involved in bone formation and remodeling: osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL), tissue inhibitor of metalloproteinases 2 (TIMP-2), bone morphogenetic protein 2 (BMP-2), cartilage oligomeric matrix protein (COMP), and vascular endothelial growth factor (VEGF).

Urinary cell cycle arrest biomarkers and chitinase 3-like protein 1 (CHI3L1) to detect acute kidney injury in the critically ill: a post hoc laboratory analysis on the FINNAKI cohort

BackgroundAcute kidney injury (AKI) is a frequently occurring syndrome in critically ill patients and is associated with worse outcomes. Biomarkers allow early identification and therapy of AKI which may improve outcomes. Urine chitinase 3-like protein 1 (uCHI3L1) was recently identified as a promising urinary biomarker for AKI. In this multicenter study, we evaluated the diagnostic performance for AKI stage 2 or greater of uCHI3L1 in comparison with the urinary cell cycle arrest biomarkers urinary tissue inhibitor of metalloproteinases-2 (TIMP-2)•insulin-like growth factor-binding protein 7 (IGFBP7) measured by NephroCheck Risk®.MethodsPost hoc laboratory study of the prospective observational FINNAKI study. Of this cohort, we included patients with stored admission urine samples and availability of serum creatinine at day 1 of admission. Patients who already had AKI stage 2 or 3 at ICU admission were excluded. AKI was defined and staged according to the KDIGO definition and staging system. The primary endpoint was AKI stage 2 or 3 at day 1. Biomarker performance was assessed by the area under the curve of the receiver operating characteristic curve (AUC). We assessed individual performance and different combinations of urine biomarkers.ResultsOf 660 included patients, 49 (7.4%) had AKI stages 2–3 at day 1. All urine biomarkers were increased at admission in AKI patients. All biomarkers and most combinations had AUCs < 0.700. The combination uCHI3L1•TIMP-2 was best with a fair AUC of 0.706 (0.670, 0.718). uCHI3L1 had a positive likelihood ratio (LR) of 2.25 which was comparable to that of the NephroCheck Risk® cutoff of 2.0, while the negative LR of 0.53 was comparable to that of the NephroCheck Risk® cutoff of 0.3.ConclusionsWe found that uCHI3L1 and NephroCheck Risk® had a comparable diagnostic performance for diagnosis of AKI stage 2 or greater within a 24-h period in this multicenter FINNAKI cohort. In contrast to initial discovery and validation studies, the diagnostic performance was poor. Possible explanations for this observation are differences in patient populations, proportion of emergency admissions, proportion of functional AKI, rate of developing AKI, and observation periods for diagnosis of AKI.

The Role of TIMP3 in Microvascular Endothelial Cell‐Extracellular Matrix Interaction and Regulation of Microvascular Barrier Function

BackgroundDuring sepsis, disruption of the pulmonary microvascular endothelial cell (PMVEC) barrier is associated with lung dysfunction and death. PMVEC‐PMVEC interactions through adherens and tight junctions are crucial for maintaining barrier function, as disruption of these junctions causes protein leak. Multiple mechanisms support PMVEC junctional and barrier function, including PMVEC binding to the extracellular matrix (ECM). Data suggest that decreased PMVEC‐ECM interactions under pro‐inflammatory conditions, indicated by altered focal adhesion kinase (FAK) phosphorylation, may be associated with increased leak. Tissue inhibitor of metalloproteinases 3 (TIMP3) is shown to regulate barrier function as PMVEC from Timp3−/− mice have increased leak; however, the specific mechanisms are unknown. Interestingly, previous studies in the developing lung found that TIMP3 can mediate PMVEC‐ECM interactions. Based on this, I hypothesized that TIMP3 maintains PMVEC barrier function by promoting PMVEC‐ECM interactions.MethodPMVEC from wild type (WT) and Timp3−/− mice were cultured on different matrices and stimulated with pro‐inflammatory cytokines (sepsis) vs control PBS. PMVEC‐ECM interactions were assessed using adhesion assays, immunocytochemistry, and the XPERT‐permeability assay.ResultsExamination of PMVEC adhesion to fibronectin, laminin, vitronectin, and collagen I indicated preferential adhesion of WT PMVEC to fibronectin with lowest adhesion to collagen. While Timp3−/− PMVEC appeared to also preferentially adhere to fibronectin, overall adhesion to the ECM vs. WT PMVEC was reduced. Assessment of phosphorylated FAK (pFAK) through immunocytochemistry revealed reduced abundance of pFAK in both cell types under cytomix‐treatment vs. PBS. Additionally, pFAK organisation and localised distribution around the periphery of cell borders appeared to be reduced in Timp3−/− vs. WT PMVEC. The XPERT‐permeability assay revealed differences in total inter‐PMVEC avidin fluorescence and specifically avidin leak diffusion distance between PMVEC and the ECM in WT vs. Timp3−/− cells, especially under cytomix‐treatment.SignificanceThese findings demonstrate that sepsis disrupts the interaction of WT PMVEC with ECM, which is further enhanced in Timp3−/− cells. The results suggest that TIMP3 may play an important role in regulating PMVEC‐ECM interactions, and could help elucidate therapeutic targets to maintain or rescue PMVEC barrier integrity in sepsis.Support or Funding InformationHeart and Stroke Foundation of Ontario, Ontario Thoracic Society Grant‐in‐Aid, NSERC Discovery Grant

Changes in extracellular matrix in different stages of colorectal cancer and their effects on proliferation of cancer cells.

BACKGROUNDThe extracellular matrix is the main component of the tumor microenvironment. Extracellular matrix remodels with the oncogenesis and development of tumors. Previous studies usually focused on the changes of proteins in normal colorectal tissues and colorectal cancers. Little is known about the changes in the extracellular matrix in different stages of colorectal cancer and the effects of these changes on the development of this cancer.AIMTo test the changes of type I collagen, type IV collagen, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-3 (TIMP-3) in different stages of colorectal cancer and the effects of these changes on the proliferation of cancer cells.METHODSThe extracellular matrix from various stages of colorectal cancer and normal colon tissue was obtained by using acellular technology. We used proteomics to detect the differential expression of proteins between normal colon tissues and colorectal cancer tissues, and then we used Western blot to observe their expression in each stage of colorectal cancer and in normal colon tissue. By co-culturing the extracellular matrix and HT29 colon cancer cells in vivo and in vitro, we tested the cancer cell proliferation rate in vitro by methyl thiazolyl tetrazolium (MTT) assay and in vivo by measuring the tumor volume.RESULTSThe expression of type I collagen and MMP-2 increased with increased tumor stage. The expression of MMP-9 was higher in colorectal cancer tissues and was highest in stage III cancer. The expression of type IV collagen and TIMP-3 decreased with increased tumor stage. The proliferation rate of cancer cells in the extracellular matrix of colorectal cancer was higher than that in the extracellular matrix of the normal colon.CONCLUSIONThese data suggest that the extracellular matrix structure and composition become disorganized during the development of tumors, which is more conducive for the growth of cancer cells.

Elastin is a key factor of tumor development in colorectal cancer

BackgroundColorectal cancer (CRC) is the most common cancer and a leading cause of death worldwide. Extracellular matrix (ECM) proteins regulate tumor growth and development in CRC. Elastin (ELN) is a component of ECM proteins involved in the tumor microenvironment. However, the role of ELN in CRC remains unclear.MethodsIn this study, we analyzed ELN gene expression in tumors from CRC patients and adjacent non-tumor colon tissues and healthy controls from two existing microarray datasets. ELN protein was measured in human normal colon cells and colon cancer epithelial cells and tumor development was assessed in colon epithelial cells cultured in medium with or without ELN peptide on plates coated with ELN recombinant protein. Control plates were coated with PBS only.ResultsWe found ELN gene expression was increased in tumors from CRC patients compared to adjacent non-tumor tissues and healthy controls. ELN protein was increased in cancer cells compared to normal colon epithelial cells. Transforming growth factor beta (TGF-β) was a key cytokine to induce production of ECM proteins, but it did not induce ELN expression in colon cancer cells. Matrix metalloproteinase 9 (MMP9) gene expression was increased, but that of MMP12 (elastase) did not change between CRC patients and control. Tissue inhibitor of metalloproteinases 3 (TIMP3) gene expression was decreased in colon tissues from CRC patients compared to healthy controls. However, MMP9, MMP12 and TIMP3 proteins were increased in colon cancer cells. ELN recombinant protein increased proliferation and wound healing in colon cancer epithelial cells. This had further increased in cancer cells incubated in plates coated with recombinant ELN coated plate and in culture media containing ELN peptide. A potential mechanism was that ELN induced epithelial mesenchymal transition with increased alpha-smooth muscle actin and vimentin proteins but decreased E-cadherin protein. Tumor necrosis factor alpha (TNF) mRNA was also increased in CRC patients compared to controls. ELN recombinant protein induced further increases in TNF protein in mouse bone marrow derived macrophages after lipopolysaccharide stimulation.ConclusionsThese data suggest ELN regulates tumor development and the microenvironment in CRC.

Sepsis-Associated Acute Kidney Disease

IntroductionAbout one-third of critically ill patients with acute kidney injury (AKI) develop persistently decreased kidney function, known as acute kidney disease (AKD), which may progress to chronic kidney disease (CKD). Although sepsis is the most common cause of AKI, little is known about sepsis-associated AKD.MethodsUsing data from a large randomized trial including 1341 patients with septic shock, we studied patients with stage 2 or 3 AKI on day 1 of hospitalization. We defined AKD as a persistently reduced glomerular filtration rate for >7 days. In addition to clinical data, we measured several urinary biomarkers (tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 [TIMP-2∗IGFBP7], neutrophil gelatinase-associated lipocalin [NGAL], kidney injury molecule-1 [KIM-1], liver-type fatty acid binding protein, and type 4 collagen) at 0, 6, and 24 hours, to predict AKD.ResultsOf 598 patients, 119 (19.9%) died within 7 days, 318 (53.2%) had early reversal of AKI within the first 7 days, whereas 161 (26.9%) developed AKD. In patients with early reversal, 45 (14.2%) had relapsed AKI after early reversal, and only about one-third of these recovered. Among patients developing AKD, only 15 (9.3%) recovered renal function prior to discharge. Male sex, African American race, and underlying CKD were more predominant in patients developing AKD. None of the biomarkers tested performed well for prediction of AKD, although NGAL modestly increased the performance of a clinical model.ConclusionsAKD is common in patients with septic shock, especially among African American males and those with underlying CKD. Existing AKI biomarkers have limited utility for predicting AKD but might be useful together with clinical variables. Novel predictive biomarkers for renal recovery are needed.

Role of FGF and Hyaluronan in Choroidal Neovascularization in Sorsby Fundus Dystrophy

Sorsby’s fundus dystrophy (SFD) is an inherited blinding disorder caused by mutations in the tissue inhibitor of metalloproteinase-3 (TIMP3) gene. The SFD pathology of macular degeneration with subretinal deposits and choroidal neovascularization (CNV) closely resembles that of the more common age-related macular degeneration (AMD). The objective of this study was to gain further insight into the molecular mechanism(s) by which mutant TIMP3 induces CNV. In this study we demonstrate that hyaluronan (HA), a large glycosaminoglycan, is elevated in the plasma and retinal pigment epithelium (RPE)/choroid of patients with AMD. Mice carrying the S179C-TIMP3 mutation also showed increased plasma levels of HA as well as accumulation of HA around the RPE in the retina. Human RPE cells expressing the S179C-TIMP3 mutation accumulated HA apically, intracellularly and basally when cultured long-term compared with cells expressing wildtype TIMP3. We recently reported that RPE cells carrying the S179C-TIMP3 mutation have the propensity to induce angiogenesis via basic fibroblast growth factor (FGF-2). We now demonstrate that FGF-2 induces accumulation of HA in RPE cells. These results suggest that the TIMP3-MMP-FGF-2-HA axis may have an important role in the pathogenesis of CNV in SFD and possibly AMD.

Loss of TIMP3 expression induces inflammation, matrix degradation, and vascular ingrowth in nucleus pulposus: A new mechanism of intervertebral disc degeneration.

Low back pain (LBP) is one of the most common complains in orthopedic outpatient department and intervertebral disc degeneration (IDD) is one of the most important reasons of LBP. The mechanisms of IDD contain a complex biochemical cascade which includes inflammation, vascular ingrowth, and results in degradation of matrix. In our study, we used both in vitro and in vivo models to investigate the relation between tissue inhibitor of metalloproteinase-3 (TIMP3) expression and IDD. Loss of TIMP3 expression was found in degenerative intervertebral disc (IVD), this change of expression was closely related with the dephosphorylation of smad2/3. Overexpression of TIMP3 significantly inhibited the release of TNF-α and matrix degradation induced by Lipopolysaccharide. Vascular ingrowth was also suppressed by TIMP3 in the in vitro and in vivo models. Further, animal experiments confirmed that the degeneration of IVD was reduced after overexpression of TIMP3 in nucleus pulposus. Taken together, our results indicated TIMP-3 might play an important role in the pathogenesis of IDD and therefore be a potential therapeutic target in the future.

P14ARF inhibits regional inflammation and vascularization in intervertebral disc degeneration by upregulating TIMP3.

In this study, we identified P14 alternate reading frame (P14ARF) as a novel regulator of inflammation and vascularization in intervertebral disk degeneration (IVDD). We collected IVD tissues from IVDD patients and normal individuals for analysis of P14ARF expression. We also induced experimental IVDD by needle puncture injuries in the caudal intervertebral disks of Sprague-Dawley (SD) rats and achieved recombinant adenovirus-mediated P14ARF overexpression in experimental IVDD rats. Regulation relationships between P14ARF and tissue inhibitors of metalloproteinases-3 (TIMP3) were confirmed in P14ARF-overexpressed and TIMP3-depleted nucleus pulposus (NP) cells. Tube formation in vitro was evaluated in coculture systems of human umbilical vein endothelial cells (HUVECs) and rat degenerated NP cells (DNPCs). Inflammatory response was assessed from levels of TNF-α, IL-1β, and IL-6 and neovascularization from expression of endothelial growth factor (VEGF). The P14ARF and TIMP3 were downregulated in degenerated IVD tissue derived from patients and experimental IVDD rats. Overexpressed P14ARF suppressed inflammatory cytokine levels and vascularization. There was decreased in vitro tube formation in response to P14ARF overexpression and TIMP3 elevation. Finally, attenuated inflammatory responses and suppression of VEGF were achieved by P14ARF-mediated promotion of TIMP3 in rat DNPCs. Taken together, the present study reveals that P14ARF/TIMP3 modulation of inflammatory response and vascularization in the context of IVDD highlights a potential target for future therapeutic strategies.

AMD3100 Attenuates Post-Traumatic Osteoarthritis by Maintaining Transforming Growth Factor-β1-Induced Expression of Tissue Inhibitor of Metalloproteinase-3 via the Phosphatidylinositol 3-Kinase/Akt Pathway.

AMD3100 is a small-molecule inhibitor of the C-X-C motif chemokine ligand 12/C-X-C chemokine receptor type 4 (CXCL12/CXCR4) axis, while its role in aggrecan metabolism is unclear. We hypothesized that the AMD3100 modulates the transforming growth factor-β1 (TGF-β1)-induced expression of tissue inhibitor of metalloproteinase-3 (TIMP-3) in chondrocytes. We evaluated expression of CXCL12/CXCR4 and TIMP-3 in the knee joints of rats with and without osteoarthritis (OA) by immunohistochemistry, immunofluorescence, Western blotting, and enzyme-linked immunosorbent assay (ELISA). The rats were divided into sham control, destabilization of the medial meniscus/AMD3100-treated (DMM/AMD3100-treated), and DMM/phosphate-buffered saline (PBS)-treated groups. After 6 weeks, the rats were euthanized and subjected to histological and immunohistochemical analyses. Also, interleukin (IL)-1-pretreated primary chondrocytes were cultured in the presence of empty control (−, −), CXCL12a (+,−), CXCL12a + small interfering RNA (siRNA) CXCR4 (+,+), or CXCL12a + siNC (+NC), and the expression levels of target markers were evaluated by Western blotting and real-time reverse transcription PCR (RT-PCR). The CXCL12/CXCR4 levels were higher, and the expression of TIMP-3 was lower, in the OA rats compared to the healthy control rats. The rats in the DMM/AMD3100-treated group revealed a markedly decreased immunological response and mild pathology. Treatment with CXCL12a increased expression of aggrecan and disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) and suppressed that of TIMP-3 in IL-1-pretreated primary chondrocytes. TGF-β1 increased expression of TIMP-3, and this increase was reversed by CXCL12a via the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Moreover, these effects were inhibited by the CXCR4 antagonist AMD3100 and the PI3K inhibitor LY303511. In conclusion, inhibition of the CXCL12a/CXCR4 signaling axis maintained TIMP-3 expression via the PI3K/Akt pathway. Our findings provide insight into the mechanism by which AMD3100 prevents OA.