TIMP-2 mediated inhibition of angiogenesis: an MMP-independent mechanism

EZH2-mediated epigenetic silencing of TIMP2 promotes ovarian cancer migration and invasion

Enhancer of zeste homolog 2 (EZH2) is often increased in malignant tumors and is involved in metastasis. EZH2 silences gene expression by tri-methylating the lysine 27 residue of histone H3 (H3K27me3). However, the mechanism underlying EZH2 promotion of ovarian cancer metastasis remains elusive. Here, we showed that EZH2 is up-regulated in ovarian cancer and is associated with tumor metastasis and poor survival by mRNA sequencing and microarray results from databases. Tissue microarray and immunohistochemistry results revealed that EZH2 was negatively correlated with the expression of tissue inhibitor of metalloproteinases 2 (TIMP2). EZH2 overexpression inhibited TIMP2 expression and promoted proteolytic activities of matrix metalloproteinases 2 and 9 and vice versa. EZH2 promoted ovarian cancer invasion and migration, which could be largely reversed by TIMP2 down-regulation in vitro and in vivo. Both H3K27me3 inhibition and demethylation could reduce methylation of the TIMP2 promoter and finally reactivate TIMP2 transcription. The presence of EZH2 and H3K27me3 at the TIMP2 promoter was confirmed by chromatin immunoprecipitation. H3K27me3 and DNA methyltransferases at the promoter were significantly increased by EZH2 overexpression. These results suggest that EZH2 inhibits TIMP2 expression via H3K27me3 and DNA methylation, which relieve the repression of MMP and facilitate ovarian cancer invasion and migration.

Inflammation and vascular remodeling in the ventral hippocampus contributes to vulnerability to stress

During exposure to chronic stress, some individuals engage in active coping behaviors that promote resiliency to stress. Other individuals engage in passive coping that is associated with vulnerability to stress and with anxiety and depression. In an effort to identify novel molecular mechanisms that underlie vulnerability or resilience to stress, we used nonbiased analyses of microRNAs in the ventral hippocampus (vHPC) to identify those miRNAs differentially expressed in active (long-latency (LL)/resilient) or passive (short-latency (SL)/vulnerable) rats following chronic social defeat. In the vHPC of active coping rats, miR-455-3p level was increased, while miR-30e-3p level was increased in the vHPC of passive coping rats. Pathway analyses identified inflammatory and vascular remodeling pathways as enriched by genes targeted by these microRNAs. Utilizing several independent markers for blood vessels, inflammatory processes and neural activity in the vHPC, we found that SL/vulnerable rats exhibit increased neural activity, vascular remodeling and inflammatory processes that include both increased blood-brain barrier permeability and increased number of microglia in the vHPC relative to control and resilient rats. To test the relevance of these changes for the development of the vulnerable phenotype, we used pharmacological approaches to determine the contribution of inflammatory processes in mediating vulnerability and resiliency. Administration of the pro-inflammatory cytokine vascular endothelial growth factor-164 increased vulnerability to stress, while the non-steroidal anti-inflammatory drug meloxicam attenuated vulnerability. Collectively, these results show that vulnerability to stress is determined by a re-designed neurovascular unit characterized by increased neural activity, vascular remodeling and pro-inflammatory mechanisms in the vHPC. These results suggest that dampening inflammatory processes by administering anti-inflammatory agents reduces vulnerability to stress. These results have translational relevance as they suggest that administration of anti-inflammatory agents may reduce the impact of stress or trauma in vulnerable individuals.

Urinary Tissue Inhibitor of Metalloproteinase-2 and Insulin-Like Growth Factor-Binding Protein 7 for Risk Stratification of Acute Kidney Injury in Patients With Sepsis

Supplemental Digital Content is available in the text.

Objectives:

To examine the performance of the urinary biomarker panel tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 in patients with sepsis at ICU admission. To investigate the effect of nonrenal organ dysfunction on tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 in this population.

Method:

In this ancillary analysis, we included patients with sepsis who were enrolled in either of two trials including 39 ICUs across Europe and North America. The primary endpoint was moderate-severe acute kidney injury (equivalent to Kidney Disease Improving Global Outcome stage 2–3) within 12 hours of enrollment. We assessed biomarker performance by calculating the area under the receiver operating characteristic curve, sensitivity, specificity, and negative and positive predictive values at three cutoffs: 0.3, 1.0, and 2.0 (ng/mL)²/1,000. We also calculated nonrenal Sequential Organ Failure Assessment scores for each patient on enrollment and compared tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 results in patients with and without acute kidney injury and across nonrenal Sequential Organ Failure Assessment scores. Finally, we constructed a clinical model for acute kidney injury in this population and compared the performance of the model with and without tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7.

Results:

We included 232 patients in the analysis and 40 (17%) developed acute kidney injury. We observed significantly higher urine tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 in patients with acute kidney injury than without acute kidney injury in both patients with low and high nonrenal Sequential Organ Failure Assessment scores (p < 0.001). The area under the receiver operating characteristic curve (95% CI) of tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 was 0.84 (0.73–0.92) and 0.85 (0.76–0.94), in low and high nonrenal Sequential Organ Failure Assessment score subgroups. Performance of the tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 test was not modified by nonrenal Sequential Organ Failure Assessment (p = 0.70). In multivariate analysis, the addition of tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 significantly improved the performance of a clinical model for predicting acute kidney injury (p = 0.015).

Conclusion:

Urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 accurately predicts acute kidney injury in septic patients with or without other organ failures.

The Balance Between Metalloproteinases and TIMPs: Critical Regulator of Microvascular Endothelial Cell Function in Health and Disease

Endothelial cells (EC), especially the microvascular EC (MVEC), have critical functions in health and disease. For example, healthy MVEC provide a barrier between the fluid and protein found within the blood, and the surrounding tissue. Following tissue injury or infection, the microvascular barrier is often disrupted due to activation and dysfunction of the MVEC. Multiple mechanisms promote MVEC activation and dysfunction, including stimulation by cytokines, mechanical interaction with activated leukocytes, and exposure to harmful leukocyte-derived molecules, which collectively result in a loss of MVEC barrier function. However, MVEC activation is also critical to facilitate recruitment of inflammatory cells, such as neutrophils (PMNs) and monocytes, into the injured or infected tissue. Metalloproteinases, including the matrix metalloproteinases (MMPs) and the closely related, a disintegrin and metalloproteinases (ADAMs), have been implicated in regulating both MVEC barrier function, through cleavage of adherens and tight junctions proteins between adjacent MVEC and through degradation of the extracellular matrix, as well as PMN-MVEC interaction, through shedding of cell surface PMN receptors. Moreover, the tissue inhibitors of metalloproteinases (TIMPs), which collectively inhibit most MMPs and ADAMs, are critical regulators of MVEC activation and dysfunction through their ability to inhibit metalloproteinases and thereby promote MVEC stability. However, TIMPs have been also found to modulate MVEC function through metalloproteinase-independent mechanisms, such as regulation of vascular endothelial growth factor signaling. This chapter is focused on examining the role of the metalloproteinases and TIMPs in regulation of MVEC function in both health and disease.

TNFSF15 inhibits VEGF-stimulated vascular hyperpermeability by inducing VEGFR2 dephosphorylation

Vascular hyperpermeability is critical in ischemic diseases, including stroke and myocardial infarction, as well as in inflammation and cancer. It is well known that the VEGF-VEGFR2 signaling pathways are pivotal in promoting vascular permeability; however, counterbalancing mechanisms that restrict vascular permeability to maintain the integrity of blood vessels are not yet fully understood. We report that TNF superfamily member 15 (TNFSF15), a cytokine largely produced by vascular endothelial cells and a specific inhibitor of the proliferation of these same cells, can inhibit VEGF-induced vascular permeability in vitro and in vivo, and that death receptor 3 (DR3), a cell surface receptor of TNFSF15, mediates TNFSF15-induced dephosphorylation of VEGFR2. Src homology region 2 domain-containing phosphatase-1 (SHP-1) becomes associated with DR3 upon TNFSF15 interaction with the latter. In addition, a protein complex consisting of VEGFR2, DR3, and SHP-1 is formed in response to the effects of TNFSF15 and VEGF on endothelial cells. It is plausible that this protein complex provides a structural basis for the molecular mechanism in which TNFSF15 induces the inhibition of VEGF-stimulated vascular hyperpermeability.-Yang, G.-L., Zhao, Z., Qin, T.-T., Wang, D., Chen, L., Xiang, R., Xi, Z., Jiang, R., Zhang, Z.-S., Zhang, J., Li. L.-Y. TNFSF15 inhibits VEGF-stimulated vascular hyperpermeability by inducing VEGFR2 dephosphorylation.

TIMPs: versatile extracellular regulators in cancer

A compelling long-term goal of cancer biology is to understand the crucial players during tumorigenesis in order to develop new interventions. Here, we review how the four non-redundant tissue inhibitors of metalloproteinases (TIMPs) regulate the pericellular proteolysis of a vast range of matrix and cell surface proteins, generating simultaneous effects on tumour architecture and cell signalling. Experimental studies demonstrate the contribution of TIMPs to the majority of cancer hallmarks, and human cancers invariably show TIMP deregulation in the tumour or stroma. Of the four TIMPs, TIMP1 overexpression or TIMP3 silencing is consistently associated with cancer progression or poor patient prognosis. Future efforts will align mouse model systems with changes in TIMPs in patients, will delineate protease-independent TIMP function, will pinpoint therapeutic targets within the TIMP-metalloproteinase-substrate network and will use TIMPs in liquid biopsy samples as biomarkers for cancer prognosis.

Modulation of VEGF receptor 2 signaling by protein phosphatases

Phosphorylation of serines, threonines, and tyrosines is a central event in signal transduction cascades in eukaryotic cells. The phosphorylation state of any particular protein reflects a balance of activity between kinases and phosphatases. Kinase biology has been exhaustively studied and is reasonably well understood, however, much less is known about phosphatases. A large body of evidence now shows that protein phosphatases do not behave as indiscriminate signal terminators, but can function both as negative or positive regulators of specific signaling pathways. Genetic models have also shown that different protein phosphatases play precise biological roles in health and disease. Finally, genome sequencing has unveiled the existence of many protein phosphatases and associated regulatory subunits comparable in number to kinases. A wide variety of roles for protein phosphatase roles have been recently described in the context of cancer, diabetes, hereditary disorders and other diseases. In particular, there have been several recent advances in our understanding of phosphatases involved in regulation of vascular endothelial growth factor receptor 2 (VEGFR2) signaling. The receptor is the principal signaling molecule mediating a wide spectrum of VEGF signal and, thus, is of paramount significance in a wide variety of diseases ranging from cancer to cardiovascular to ophthalmic. This review focuses on the current knowledge about protein phosphatases' regulation of VEGFR2 signaling and how these enzymes can modulate its biological effects.

Plasma levels and diagnostic utility of VEGF, MMP-2 and TIMP-2 in the diagnostics of breast cancer patients

OBJECTIVE

We investigated plasma levels and diagnostic utility of vascular endothelial growth factor VEGF, matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of metalloproteinase-2 (TIMP-2) in comparison to cancer antigen 15-3 (CA 15-3).

METHODS

Plasma levels of tested parameters were determined using enzyme-linked immunosorbent assay (ELISA) while CA 15-3 with chemiluminescent microparticle immunoassay (CMIA).

RESULTS

The plasma levels of VEGF, TIMP-2 showed significantly higher than CA 15-3 values of the diagnostic sensitivity, the predictive values of positive and negative test results (PPV, NPV) and the area under the receiver-operating characteristics (ROC) curve (AUC) in early stages of breast cancer (BC). The combined use of the tested parameters with CA 15-3 resulted in the increase in sensitivity, NPV and AUC, especially in the combination with VEGF (83%; 72%; 0.888) and TIMP-2 (83%; 72%; 0.894). The highest values were obtained for combination of all three parameters (93%; 85%; 0.923).

CONCLUSIONS

These findings suggest the usefulness of the tested parameters in the diagnosis of BC, especially VEGF and TIMP-2 with CA 15-3 in early stages of BC, which could be a new diagnostic panel.

Association of TIMP-2-418G/C and TIMP-2-303G/A with gastric cancer: a meta-analysis

Background

According to the relevant reports, TIMP-2 polymorphism might be associated with the susceptibility to gastric cancer. Owing to the inconclusive results from the published studies based on the association between TIMP-2 single nucleotide polymorphisms (SNPs) and gastric cancer susceptibility, a meta-analysis was conducted to investigate the correlation between the TIMP-2 SNPs and the risk of gastric cancer.

Materials and methods

PubMed, Embase, CNKI and Wanfang databases were systematically searched to cover all the studies based on the association of two SNPs with the susceptibility to gastric cancer published before April 2016. Pooled odds ratios (ORs) and 95% confidence intervals were calculated for all genetic models.

Results

A total of six case–control studies on TIMP-2-418G/C and four studies on TIMP-2-303G/A were included. No obvious association was found between TIMP-2-418G/C polymorphism and the risk of gastric cancer in all the genetic models. On the other hand, TIMP-2-303G/A polymorphism had a significant association with increased risk of gastric cancer in homozygote recessive and allele comparisons, and similar results were observed in subgroups of Asian populations, but there were inadequate data to completely verify the association between TIMP-2-303G/A and gastric cancer.

Conclusion

TIMP-2-418G/C polymorphism is not correlated with the risk of gastric cancer, while TIMP-2-303G/A is a risk factor for gastric cancer, especially in Asian populations. However, owing to the limited cases, the results of TIMP-2-303G/A should be thoroughly examined and validated with large-scale and well-designed studies.

Growth-stimulatory activity of TIMP-2 is mediated through c-Src activation followed by activation of FAK, PI3-kinase/AKT, and ERK1/2 independent of MMP inhibition in lung adenocarcinoma cells

Tissue inhibitors of metalloproteinases (TIMPs) control extracellular matrix (ECM) homeostasis by inhibiting the activity of matrix metalloproteinases (MMPs), which are associated with ECM turnover. Recent studies have revealed that TIMPs are implicated in tumorigenesis in both MMP-dependent and MMP-independent manners. We examined a mechanism by which TIMP-2 stimulated lung adenocarcinoma cell proliferation, independent of MMP inhibition. The stimulation of growth by TIMP-2 in A549 cells required c-Src kinase activation. c-Src kinase activity, induced by TIMP-2, concomitantly increased FAK, phosphoinositide 3-kinase (PI3-kinase)/AKT, and ERK1/2 activation. Selective knockdown of integrin α3β1, known as a TIMP-2 receptor, did not significantly change TIMP-2 growth promoting activity. Furthermore, we showed that high TIMP-2 expression in lung adenocarcinomas is associated with a worse prognosis from multiple cohorts, especially for stage I lung adenocarcinoma. Through integrated analysis of The Cancer Genome Atlas data, TIMP-2 expression was significantly associated with the alteration of driving genes, c-Src activation, and PI3-kinase/AKT pathway activation. Taken together, our results demonstrate that TIMP-2 stimulates lung adenocarcinoma cell proliferation through c-Src, FAK, PI3-kinase/AKT, and ERK1/2 pathway activation in an MMP-independent manner.

Regulation of Matrix Metalloproteinase-2 Activity by COX-2-PGE2-pAKT Axis Promotes Angiogenesis in Endometriosis

Endometriosis is characterized by the ectopic development of the endometrium which relies on angiogenesis. Although studies have identified the involvement of different matrix metalloproteinases (MMPs) in endometriosis, no study has yet investigated the role of MMP-2 in endometriosis-associated angiogenesis. The present study aims to understand the regulation of MMP-2 activity in endothelial cells and on angiogenesis during progression of ovarian endometriosis. Histological and biochemical data showed increased expressions of vascular endothelial growth factor (VEGF), VEGF receptor-2, cycloxygenase (COX)-2, von Willebrand factor along with angiogenesis during endometriosis progression. Women with endometriosis showed decreased MMP-2 activity in eutopic endometrium as compared to women without endometriosis. However, ectopic ovarian endometrioma showed significantly elevated MMP-2 activity with disease severity. In addition, increased MT1MMP and decreased tissue inhibitors of metalloproteinases (TIMP)-2 expressions were found in the late stages of endometriosis indicating more MMP-2 activation with disease progression. In vitro study using human endothelial cells showed that prostaglandin E2 (PGE2) significantly increased MMP-2 activity as well as tube formation. Inhibition of COX-2 and/or phosphorylated AKT suppressed MMP-2 activity and endothelial tube formation suggesting involvement of PGE2 in regulation of MMP-2 activity during angiogenesis. Moreover, specific inhibition of MMP-2 by chemical inhibitor significantly reduced cellular migration, invasion and tube formation. In ovo assay showed decreased angiogenic branching upon MMP-2 inhibition. Furthermore, a significant reduction of lesion numbers was observed upon inhibition of MMP-2 and COX-2 in mouse model of endometriosis. In conclusion, our study establishes the involvement of MMP-2 activity via COX-2-PGE2-pAKT axis in promoting angiogenesis during endometriosis progression.

β-catenin activity in late hypertrophic chondrocytes locally orchestrates osteoblastogenesis and osteoclastogenesis

Trabecular bone formation is the last step in endochondral ossification. This remodeling process of cartilage into bone involves blood vessel invasion and removal of hypertrophic chondrocytes (HTCs) by chondroclasts and osteoclasts. Periosteal- and chondrocyte-derived osteoprogenitors utilize the leftover mineralized HTC matrix as a scaffold for primary spongiosa formation. Here, we show genetically that β-catenin (encoded by Ctnnb1), a key component of the canonical Wnt pathway, orchestrates this remodeling process at multiple levels. Conditional inactivation or stabilization of β-catenin in HTCs by a Col10a1-Cre line locally modulated osteoclastogenesis by altering the Rankl:Opg ratio in HTCs. Lack of β-catenin resulted in a severe decrease of trabecular bone in the embryonic long bones. Gain of β-catenin activity interfered with removal of late HTCs and bone marrow formation, leading to a continuous mineralized hypertrophic core in the embryo and resulting in an osteopetrotic-like phenotype in adult mice. Furthermore, β-catenin activity in late HTCs is required for chondrocyte-derived osteoblastogenesis at the chondro-osseous junction. The latter contributes to the severe trabecular bone phenotype in mutants lacking β-catenin activity in HTCs.

Summary: The conditional modulation of β-catenin activity in late hypertrophic chondrocytes locally regulates osteoclast differentiation and the transdifferentiation of chondrocytes into osteoblasts.

An engineered TIMP2-based and enediyne-integrated fusion protein for targeting MMP-14 shows potent antitumor efficacy

Recent studies have shown that MMP-14 is highly expressed in a panel of human solid tumors and poses as a potential molecular target for anticancer drugs. Currently, major strategies for targeted therapeutics have mainly focused on the use of antibody or ligand-based agents. For seeking an alternative approach, it is of interest to employ endogenous proteins as drug delivery carriers. Considering the facts that TIMP2, the tissue inhibitor of metalloproteinase 2, shows specific interaction with MMP-14 and that Lidamycin (LDM), an extremely potent cytotoxic antitumor antibiotic, consists of an apoprotein (LDP) and a highly active enediyne (AE); we designed and prepared a TIMP2-based and enediyne-integrated fusion protein LDP(AE)-TIMP2 by DNA recombination and molecular reconstitution consecutively. Furthermore, the MMP-14 binding attributes of the active fusion protein were determined and its therapeutic efficacy against human esophageal carcinoma KYSE150 xenograft and human fibrosarcoma HT1080 xenograft models in nude mice was investigated. It is suggested that TIMP2, the endogenous and MMP-14 binding protein, might serve as a guided carrier for targeted therapeutics.

Glycoprotein non-metastaticmelanoma protein B promotes glioma motility and angiogenesis through the Wnt/β-catenin signaling pathway

Glioma is a common tumor with high mortality and poor overall survival. However, the regulatory mechanisms of glioma tumorigenesis and glioma cell motility are completely unknown. Here, we investigated the role of glycoprotein non-metastatic melanoma protein B in glioma. The expression of glycoprotein non-metastatic melanoma protein B is observed to be aberrantly regulated in glioma tissues and cells, and high levels of glycoprotein non-metastatic melanoma protein B present an inverse correlation with the survival of glioma patients. Compared with the control, glycoprotein non-metastatic melanoma protein B inhibition significantly retarded the proliferation and migration of human glioma cells. The tube formation ability of HBMECs induced by glioma cells was also remarkably reduced by glycoprotein non-metastatic melanoma protein B silencing. Increased levels of VEGF-C and TEM7 were down-regulated by the suppression of glycoprotein non-metastatic melanoma protein B in glioma cells. Additionally, the activity of MMP-2/3/9 was assessed in glioma cells using Western blotting and gelatin zymography assay; their activities were strongly decreased following the suppression of glycoprotein non-metastatic melanoma protein B. Further studies suggested that canonical Wnt/β-catenin pathway was activated, but was inactivated by glycoprotein non-metastatic melanoma protein B suppression in glioma cells. In conclusion, we demonstrate that glycoprotein non-metastatic melanoma protein B might be an inducer for glioma and could enhance matrix metalloproteinase activity through Wnt/β-catenin pathway to contribute to glioma tumorigenesis. This may represent a new understanding for malignant glioma.

Cross-species validation of cell cycle arrest markers for acute kidney injury in the rat during sepsis

Background

The recent discovery of cell cycle arrest biomarkers, tissue inhibitor of metalloproteinases (TIMP)-2 and insulin-like growth factor binding protein 7 (IGFBP7), has led to a newly available clinical test for acute kidney injury. The performance of these markers in preclinical studies has not been established. Therefore, we sought to evaluate the performance of TIMP-2 and IGFBP7 in rats undergoing cecal ligation and puncture.

Methods

In this secondary analysis, we analyzed banked urine samples from 60 Sprague-Dawley rats undergoing cecal ligation and puncture (CLP). Samples were obtained from baseline, 18 h after CLP, at the end of fluid resuscitation (22 h after CLP), and again 24 h later. We measured TIMP-2 and IGFBP7 and compared the results to acute kidney injury by RIFLE criteria for creatinine using area under the receiver operating characteristic curve (AUC). The primary endpoint was moderate-to-severe acute kidney injury (AKI) (I or F criteria), and the primary time point was immediately after fluid resuscitation. Secondary outcomes included mortality and comparisons with other biomarkers: cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) in both urine and plasma.

Results

After fluid resuscitation, urine [TIMP-2] and [IGFBP7] were significantly higher in animals developing moderate-to-severe AKI (p = 0.002 and p = 0.01). AUC of [TIMP-2]·[IGFBP7] for AKI was 0.89 (95 % CI 0.80–0.98). By contrast, the next best AUC was seen with plasma cystatin C (0.78; 95 % CI 0.65–0.90). [TIMP-2]·[IGFBP7] also predicted mortality (AUC 0.69; 95 % CI 0.53–0.85).

Conclusions

In this experimental model of sepsis in the rat, cell cycle arrest biomarkers TIMP-2 and IGFBP7 are valid predictors of acute kidney injury.

The cell cycle biomarkers: promising research, but do not oversell them

This review focuses on the most recent scientific and clinical information on the development and clinical applicability of the cell cycle biomarkers TIMP-2 and IGFBP-7 in the diagnosis and prognosis of patients at risk for and suffering from acute kidney injury (AKI). A number of evaluation studies have demonstrated that compared with existing biomarkers, urinary excretion of the product of both biomarkers, [TIMP-2]•[IGFBP-7], improved diagnostic performance in assessing the risk for AKI, predicting the need for renal replacement therapy, AKI-related complications and short- and long-term prognoses. The reference intervals for these biomarkers, measured by the recently approved NephroCheck test, have been determined in apparently healthy adults and those with stable chronic morbid conditions without AKI. This review recognizes that the combination of these two cell cycle arrest markers for the early detection of AKI is promising but concludes that its clinical impact is still unproved. Clinicians should understand the utility and limitations of this test before deciding whether to make it available at their institution.

DNA-PKcs plays role in cancer metastasis through regulation of secreted proteins involved in migration and invasion

The DNA-dependent protein kinase catalytic subunit (DNA-PKcs) plays a major role in DNA damage signaling and repair and is also frequently overexpressed in tumor metastasis. We used isogenic cell lines expressing different levels of DNA-PKcs to investigate the role of DNA-PKcs in metastatic development. We found that DNA-PKcs participates in melanoma primary tumor and metastasis development by stimulating angiogenesis, migration and invasion. Comparison of conditioned medium content from DNA-PKcs-proficient and deficient cells reveals that DNA-PKcs controls secretion of at least 103 proteins (including 44 metastasis-associated with FBLN1, SERPINA3, MMP-8, HSPG2 and the inhibitors of matrix metalloproteinases, such as α-2M and TIMP-2). High throughput analysis of secretomes, proteomes and transcriptomes, indicate that DNA-PKcs regulates the secretion of 85 proteins without affecting their gene expression. Our data demonstrate that DNA-PKcs has a pro-metastatic activity via the modification of the tumor microenvironment. This study shows for the first time a direct link between DNA damage repair and cancer metastasis and highlights the importance of DNA-PKcs as a potential target for anti-metastatic treatment.

Maintenance of a Protein Structure in the Dynamic Evolution of TIMPs over 600 Million Years

Deciphering the events leading to protein evolution represents a challenge, especially for protein families showing complex evolutionary history. Among them, TIMPs represent an ancient eukaryotic protein family widely distributed in the animal kingdom. They are known to control the turnover of the extracellular matrix and are considered to arise early during metazoan evolution, arguably tuning essential features of tissue and epithelial organization. To probe the structure and molecular evolution of TIMPs within metazoans, we report the mining and structural characterization of a large data set of TIMPs over approximately 600 Myr. The TIMPs repertoire was explored starting from the Cnidaria phylum, coeval with the origins of connective tissue, to great apes and humans. Despite dramatic sequence differences compared with highest metazoans, the ancestral proteins displayed the canonical TIMP fold. Only small structural changes, represented by an α-helix located in the N-domain, have occurred over the evolution. Both the occurrence of such secondary structure elements and the relative solvent accessibility of the corresponding residues in the three-dimensional structures raises the possibility that these sites represent unconserved element prone to accept variations.

Tissue inhibitor of metalloproteinases 3-dependent microvascular endothelial cell barrier function is disrupted under septic conditions

Sepsis is associated with dysfunction of microvascular endothelial cells (MVEC) leading to tissue edema and multiple organ dysfunction. Metalloproteinases can regulate MVEC function through processing of cell surface proteins, and tissue inhibitor of metalloproteinases 3 (TIMP3) regulates metalloproteinase activity in the lung following injury. We hypothesize that TIMP3 promotes normal pulmonary MVEC barrier function through inhibition of metalloproteinase activity. Naive Timp3(-/-) mice had significantly higher basal pulmonary microvascular Evans blue (EB) dye-labeled albumin leak vs. wild-type (WT) mice. Additionally, cecal-ligation/perforation (CLP)-induced sepsis significantly increased pulmonary microvascular EB-labeled albumin leak in WT but not Timp3(-/-) mice. Similarly, PBS-treated isolated MVEC monolayers from Timp3(-/-) mice displayed permeability barrier dysfunction vs. WT MVEC, evidenced by lower transendothelial electrical resistance and greater trans-MVEC flux of fluorescein-dextran and EB-albumin. Cytomix (equimolar interferon γ, tumor necrosis factor α, and interleukin 1β) treatment of WT MVEC induced significant barrier dysfunction (by all three methods), and was associated with a time-dependent decrease in TIMP3 mRNA and protein levels. Additionally, basal Timp3(-/-) MVEC barrier dysfunction was associated with disrupted MVEC surface VE-cadherin localization, and both barrier dysfunction and VE-cadherin localization were rescued by treatment with GM6001, a synthetic metalloproteinase inhibitor. TIMP3 promotes normal MVEC barrier function, at least partially, through inhibition of metalloproteinase-dependent disruption of adherens junctions, and septic downregulation of TIMP3 may contribute to septic MVEC barrier dysfunction.

5-Caffeoylquinic acid inhibits invasion of non-small cell lung cancer cells through the inactivation of p70S6K and Akt activity: Involvement of p53 in differential regulation of signaling pathways

In the present study, we investigated the effects and molecular mechanism of 5-caffeoylquinic acid (5-CQA), a natural phenolic compound isolated from Ligularia fischeri, on cell invasion, proliferation and adhesion in p53 wild-type A549 and p53-deficient H1299 non-small cell lung cancer (NSCLC) cells. 5-CQA abrogated mitogen-stimulated invasion, but not proliferation, in both A549 and H1299 cells. In addition, 5-CQA inhibited mitogen-stimulated adhesion in A549 cells only. Anti-invasive activity of 5-CQA in A549 cells was mediated by the inactivation of p70(S6K)-dependent signaling pathway. In contrast, in H1299 cells the inactivation of Akt was found to be involved in 5-CQA-mediated inhibition of cell invasion. Collectively, these findings demonstrate the pharmacological roles and molecular targets of 5-CQA in regulating NSCLC cell fate, and suggest further evaluation and development of 5-CQA as a potential therapeutic agent for the treatment and prevention of lung cancer.

Dual effect of LPS on murine myeloid leukemia cells: Pro-proliferation and anti-proliferation

Modification of the bone marrow microenvironment is considered as a promising strategy to control leukemic cell proliferation, diseases progression and relapse after treatment. However, due to the diversity and complexity of the cellular and molecular compartments in the leukemic microenvironment, it is extremely difficult to dissect the role of each individual molecule or cell type in vivo. Here we established an in vitro system to dissect the role of lipopolysaccharide (LPS), stromal cells and endothelial cells in the growth of mouse myeloid tumor cells and B-lymphoma cells. We found that either LPS or bone marrow stromal cells as a feeder layer in culture is required for the proliferation of myeloid tumor cells. Surprisingly, the growth of myeloid leukemic cells on stromal cells is strongly inhibited when coupled with LPS in culture. This opposing effect of LPS, a complete switch from pro-proliferation to antitumor growth is due, at least in part, to the rapidly increased production of interleukin 12, Fas ligand and tissue inhibitor of metalloproteinases-2 from stromal cells stimulated by LPS. These results demonstrate that LPS can either facilitate or attenuate tumor cell proliferation, thus changing the disease course of myeloid leukemias through its direct effect or modulation of the tumor microenvironment.

Clinical Use of the Urine Biomarker [TIMP-2] × [IGFBP7] for Acute Kidney Injury Risk Assessment

Acute kidney injury (AKI) is a serious complication, commonly occurring in the critically ill population, with devastating short- and long-term consequences. Despite standardization of the definition and staging of AKI, early recognition remains challenging given that serum creatinine level is a marker, albeit imperfect, of kidney function and not kidney injury. Furthermore, the delay in increase in serum creatinine level after loss of glomerular filtration also prevents timely detection of decreased kidney function in patients with AKI. During the past decade, numerous clinical investigations have evaluated the utility of several biomarkers in the early diagnosis and risk stratification of AKI. In 2014, the US Food and Drug Administration approved the marketing of a test based on the combination of urine concentrations of tissue inhibitor of metalloproteinase 2 and insulin-like growth factor binding protein 7 ([TIMP-2] × [IGFBP7]) to determine whether certain critically ill patients are at risk for developing moderate to severe AKI. The optimal role of this biomarker in the diagnosis, management, and prognosis of AKI in different clinical settings requires further clarification. In this perspective, we summarize the biological actions of these 2 cell-cycle arrest biomarkers and present important considerations regarding the clinical application, interpretation, and limitations of this novel test for the early detection of AKI.

Tissue inhibitor of metalloproteinase 2 inhibits activation of the β-catenin signaling in melanoma cells

The tissue inhibitor of metalloproteinase (TIMP) family, including TIMP-2, regulates the activity of multifunctional metalloproteinases in pathogenesis of melanoma. The Wnt/β-catenin pathway is constitutively activated and plays a critical role in melanoma progression. However, the relationship between TIMP-2 expression and β-catenin activity is still unclear. We hypothesize that TIMP-2 over expression inhibits the activation of the Wnt/β-catenin pathway in melanoma cells. Protein expression, distribution, and transcriptional activity of β-catenin were assayed in established stable melanoma cell lines: parental A2058 expressing, A2058 T2-1 over-expressing (T2-1), and A2058 T2R-7 under-expressing (T2R-7) TIMP-2. Compared to T2-1 cells at the basal level, T2R-7 showed significantly lower amount protein and weaker immunofluorescence staining of β-catenin. This regulation is through posttranslational level via ubiquitination. Functionally, proliferation and cell growth were lower in T2R-7 compared to A2058 and T2-1. Lithium treatment was used to mimics activation of the Wnt/β-catenin pathway. In T2R-7 cells under-expressing TIMP2, lithium significantly increased total β-catenin, nuclear β-catenin, and its downstream protein phosphor-c-Myc (S62). Nuclear β-catenin staining was enhanced in T2R-7. Beta-catenin transcriptional activity and cell proliferation were also increased significantly. Axins inhibit β-catenin pathway via GSK-3 β. We further found the ratio of p-GSK-3 β (S9) to β-catenin and protein levels of Axins were significantly lower, whereas downstream Wnt 11 was high in T2R-7 treated with lithium. Collectively, the high level of TIMP-2 protein inhibits the activation of the Wnt/β-catenin pathway, thus suppressing proliferation. Insights in the molecular mechanisms of TIMP-2 may provide promising opportunities for anti-proliferative therapeutic intervention.

Rasip1 is essential to blood vessel stability and angiogenic blood vessel growth

Cardiovascular function depends on patent, continuous and stable blood vessel formation by endothelial cells (ECs). Blood vessel development initiates by vasculogenesis, as ECs coalesce into linear aggregates and organize to form central lumens that allow blood flow. Molecular mechanisms underlying in vivo vascular 'tubulogenesis' are only beginning to be unraveled. We previously showed that the GTPase-interacting protein called Rasip1 is required for the formation of continuous vascular lumens in the early embryo. Rasip1(-/-) ECs exhibit loss of proper cell polarity and cell shape, disrupted localization of EC-EC junctions and defects in adhesion of ECs to extracellular matrix. In vitro studies showed that Rasip1 depletion in cultured ECs blocked tubulogenesis. Whether Rasip1 is required in blood vessels after their initial formation remained unclear. Here, we show that Rasip1 is essential for vessel formation and maintenance in the embryo, but not in quiescent adult vessels. Rasip1 is also required for angiogenesis in three models of blood vessel growth: in vitro matrix invasion, retinal blood vessel growth and directed in vivo angiogenesis assays. Rasip1 is thus necessary in growing embryonic blood vessels, postnatal angiogenic sprouting and remodeling, but is dispensable for maintenance of established blood vessels, making it a potential anti-angiogenic therapeutic target.

Adipose-derived stem cells increase angiogenesis through matrix metalloproteinase-dependent collagen remodeling

Adipose-derived stem cells (ASCs) are key regulators of new blood vessel formation and widely investigated for their role in tissue regeneration and tumorigenesis. However, the cellular and molecular mechanisms through which ASCs regulate angiogenesis are not well understood. Here, it was our goal to test the functional contribution of ASC-mediated extracellular matrix (ECM) remodeling on endothelial cell invasion. To isolate the effect of ECM-remodeling, ASCs were embedded within 3-D collagen type I hydrogels and pre-cultured for 7 days; controls were not pre-cultured. A confluent monolayer of human umbilical vein endothelial cells (HUVECs) was seeded on top and its invasion into the underlying hydrogel was analyzed. Without pre-culture, ASCs inhibited vascular sprouting by stabilizing the endothelium. In contrast, 7 day pre-culture of ASCs drastically increased invasion by HUVECs. This effect was largely mediated by proteolytic ECM degradation by ASC-derived matrix metalloproteinases (MMPs) rather than vascular endothelial growth factor (VEGF), as our results indicated that blockade of MMPs, but not VEGF, inhibited endothelial sprouting. Collectively, these data suggest that the angiogenic capability of ASCs is modulated by their proteolytic remodeling of the ECM, opening new avenues for pro- and anti-angiogenic therapies.

RGD mimetics γ-AApeptides and methods of use (US 20,140,004,039 A1): a patent evaluation

The patent (US 20140004039 A1) claims Arg-Gly-Asp (RGD) mimetics based on a new type of peptidomimetics - γ-AApeptides - which display high binding affinity and specificity to integrin αvβ3. Integrin αvβ3 is one of the most important proteins involved in tumor angiogenesis and metastasis of solid tumors. It binds tightly to the tripeptide RGD, a prominent recognition motif found in extracellular matrix proteins. As αvβ3 is frequently upregulated during tumor angiogenesis, molecules mimicking the RGD recognition motif may target αvβ3 specifically and therefore can be used for cancer prevention or targeted diagnosis. Indeed, several positron emission tomography tracers targeting αvβ3 are currently under clinical investigation. γ-AApeptides as a new class of peptidomimetics show enhanced stability against proteolytic degradation and are amendable for derivatization due to their enormous chemodiversity. γ-AApeptide-based RGD mimetics, including linear, cyclic and multimeric γ-AApeptides, display comparable binding affinity and specificity to integrin αvβ3. These RGD mimetics can be synthesized easily on the solid phase and have been shown to be excellent positron emission tomography tracers by targeting glioblastoma tumor on the mouse model. As γ-AApeptide-based peptidomimetics are more stable than RGD peptides, they could be novel agents for the diagnostics and treatment of various cancers.

TIMP-2 Interaction with MT1-MMP Activates the AKT Pathway and Protects Tumor Cells from Apoptosis

Membrane-type 1 matrix metalloproteinase (MT1-MMP), a transmembrane proteinase with an extracellular catalytic domain and a short cytoplasmic tail, degrades a variety of extracellular matrix (ECM) components. In addition, MT1-MMP activates intracellular signaling through proteolysis-dependent and independent mechanisms. We have previously shown that binding of tissue inhibitor of metalloproteinases-2 (TIMP-2) to MT1-MMP controls cell proliferation and migration, as well as tumor growth in vivo by activating the Ras—extracellular signal regulated kinase-1 and -2 (ERK1/2) pathway through a mechanism that requires the cytoplasmic but not the proteolytic domain of MT1-MMP. Here we show that in MT1-MMP expressing cells TIMP-2 also induces rapid and sustained activation of AKT in a dose- and time-dependent manner and by a mechanism independent of the proteolytic activity of MT1-MMP. Fibroblast growth factor receptor-1 mediates TIMP-2 induction of ERK1/2 but not of AKT activation; however, Ras activation is necessary to transduce the TIMP-2-activated signal to both the ERK1/2 and AKT pathways. ERK1/2 and AKT activation by TIMP-2 binding to MT1-MMP protects tumor cells from apoptosis induced by serum starvation. Conversely, TIMP-2 upregulates apoptosis induced by three-dimensional type I collagen in epithelial cancer cells. Thus, TIMP-2 interaction with MT1-MMP provides tumor cells with either pro- or anti-apoptotic signaling depending on the extracellular environment and apoptotic stimulus.

TIMP-1 overexpression in lung carcinoma enhances tumor kinetics and angiogenesis in brain metastasis

Tissue inhibitors of matrix metalloproteinase (TIMP) orchestrate many biologic activities, including inhibition of matrix metalloproteinase activity, activation of pro-matrix metalloproteinases, and regulation of cell proliferation, angiogenesis, and apoptosis induction. Tissue inhibitors of matrix metalloproteinase can play a protective role during tumor invasion and metastasis, but elevated TIMP messenger RNA levels have also been associated with aggressive cancers and poor clinical outcome. We examined the potential roles of TIMP-1 in H2009 lung adenocarcinoma cells and in cells transfected with a human TIMP-1-overexpressing vector (HB-6 and HB-1). Tumors resulting from the implantation of parental cell lines and transfected HB-1 cells into the brains of nude mice had a typical carcinoma profile, but human TIMP-1-overexpressing tumors showed enhanced tumor kinetics and focally more infiltrative features; vessel density assessed with anti-CD31 immunohistochemistry was also greater within HB-1 tumor implants. Similar effects on HB-6 and HB-1 cells versus parental cell lines and empty vector clones were observed in endothelial cell assays. Anchorage-independent growth and invasion through Matrigel were also increased in TIMP-1-overexpressing cells. Together, these results indicate tumor-promoting functions of TIMP-1 through alterations in angiogenesis, increased tumorigenicity, and invasive behavior. Although matrix metalloproteinase inhibition has been the traditionally identified function of TIMP-1, matrix metalloproteinase-independent interactions may contribute to the growth of metastatic carcinomas in the brain.

Ligularia fischeri inhibits endothelial cell proliferation, invasion and tube formation through the inactivation of mitogenic signaling pathways and regulation of vascular endothelial cadherin distribution and matrix metalloproteinase expression

Ligularia fischeri (LF) has been used as an edible herb and traditional medicine for the treatment of inflammatory and infectious diseases. In the present study, we report the effects and molecular mechanism of the ethanolic extract of LF on cell proliferation, invasion and tube formation in human umbilical vein endothelial cells (HUVECs). LF-mediated inhibition of cell proliferation was accompanied by reduced expression of cell cycle-related proteins such as cyclin-dependent kinases (Cdks) and cyclins, leading to pRb hypophosphorylation and G1 phase cell cycle arrest. We also show that LF treatment inhibited cell invasion and tube formation in HUVECs. These anti-angiogenic activities of LF were associated with the inactivation of mitogenic signaling pathways, induction of vascular endothelial (VE)-cadherin distribution at cell-cell contacts and inhibition of matrix metalloproteinase (MMP) expression. Collectively, our findings demonstrate the pharmacological functions and molecular mechanisms of LF in regulating endothelial cell fates, and support further development as a potential therapeutic agent for the treatment and prevention of angiogenesis-related disorders including cancer.

Effect of elastin-derived peptides on the production of tissue inhibitor of metalloproteinase-1, -2, and -3 and the ratios in various endothelial cell lines

Tissue inhibitors of metalloproteinases (TIMPs) control the activity of metalloproteinases. Elastin-derived peptides (EDPs) are generated as a result of the degradation of elastin fibers. The EDPs bind to the elastin receptor and exert numerous biological effects. The aim of the present study was to compare the production of TIMP-1, TIMP-2 and TIMP-3 and their ratios in human endothelial cells (ECs) derived from three clinically important vascular localizations (coronary arteries, aorta and iliac artery), and evaluate the influence of a well-known EDP, κ-elastin. The highest concentration of TIMP-1 was identified in the aortic ECs, while the lowest concentration was observed in the ECs derived from the coronary artery. The opposite pattern was observed for TIMP-2 production. When the TIMP-3 concentration was analyzed in the three EC lines, no statistically significant differences were observed. Application of κ-elastin was found to decrease the TIMP-1 concentration in the aortic ECs, while an increase in the TIMP-1 concentration was observed in the ECs derived from the iliac artery. The most significant decrease in TIMP-2 concentration following κ-elastin administration was observed in the ECs obtained from the coronary arteries. Furthermore, the highest concentration of κ-elastin resulted in an increase in TIMP-3 production in the ECs derived from the coronary arteries. The following ratios of the TIMP concentrations were calculated: TIMP-1/TIMP-2, TIMP-1/TIMP-3 and TIMP-2/TIMP-3. Each ratio presented different values for the ECs obtained from the various localizations. In the majority of cases, the addition of κ-elastin did not significantly change these proportions. Therefore, these indicators may be characteristic features that can be used to describe ECs in various clinically important vascular localizations.

Urinary biomarkers TIMP-2 and IGFBP7 early predict acute kidney injury after major surgery

Objective

To assess the ability of the urinary biomarkers IGFBP7 (insulin-like growth factor-binding protein 7) and TIMP-2 (tissue inhibitor of metalloproteinase 2) to early predict acute kidney injury (AKI) in high-risk surgical patients.

Introduction

Postoperative AKI is associated with an increase in short and long-term mortality. Using IGFBP7 and TIMP-2 for early detection of cellular kidney injury, thus allowing the early initiation of renal protection measures, may represent a new concept of evaluating renal function.

Methods

In this prospective study, urinary [TIMP-2]×[IGFBP7] was measured in surgical patients at high risk for AKI. A predefined cut-off value of [TIMP-2]×[IGFBP7] >0.3 was used for assessing diagnostic accuracy. Perioperative characteristics were evaluated, and ROC analyses as well as logistic regression models of risk assessment were calculated with and without a [TIMP-2]×[IGFBP7] test.

Results

107 patients were included in the study, of whom 45 (42%) developed AKI. The highest median values of biomarker were detected in septic, transplant and patients after hepatic surgery (1.24 vs 0.45 vs 0.47 ng/l²/1000). The area under receiving operating characteristic curve (AUC) for the risk of any AKI was 0.85, for early use of RRT 0.83 and for 28-day mortality 0.77. In a multivariable model with established perioperative risk factors, the [TIMP-2]×[IGFBP7] test was the strongest predictor of AKI and significantly improved the risk assessment (p<0.001).

Conclusions

Urinary [TIMP-2]×[IGFBP7] test sufficiently detect patients with risk of AKI after major non-cardiac surgery. Due to its rapid responsiveness it extends the time frame for intervention to prevent development of AKI.

MiR-221/222 promote human glioma cell invasion and angiogenesis by targeting TIMP2

miR-221/222 are two highly homologous microRNAs that are frequently upregulated in solid tumors. However, the effects of miR-221/222 in malignant gliomas have not been investigated thoroughly. In this study, we found that miR-221/222 were significantly upregulated in human glioma samples and glioma cell lines. Both gain- and loss-of-function studies showed that miR-221/222 regulate cell proliferation, the cell cycle and apoptosis, in addition to, invasion, metastasis, and angiogenesis in glioma cell lines. Subsequent investigations revealed that TIMP2 is a direct target of miR-221/222, and overexpression of TIMP2 reduced the miR-221/222-mediated invasion, metastasis, and angiogenesis of glioma cells. Taken together, our results suggest that the suppression of miR-221/222 may be a feasible approach for inhibiting the malignant behaviors of glioma.

Molecular control of capillary morphogenesis and maturation by recognition and remodeling of the extracellular matrix: functional roles of endothelial cells and pericytes in health and disease

This review addresses fundamental mechanisms underlying how capillaries form in three-dimensional extracellular matrices and how endothelial cells (ECs) and pericytes co-assemble to form capillary networks. In addition to playing a critical role in supplying oxygen and nutrients to tissues, recent work suggests that blood vessels supply important signals to facilitate tissue development. Here, we hypothesize that another major function of capillaries is to supply signals to suppress major disease mechanisms including inflammation, infection, thrombosis, hemorrhage, edema, ischemic injury, fibrosis, autoimmune disease and tumor growth/progression. Capillary dysfunction plays a key pathogenic role in many human diseases, and thus, this suppressing function may be attenuated and central toward the initiation and progression of disease. We describe how capillaries form through creation of EC-lined tube networks and vascular guidance tunnels in 3D extracellular matrices. Pericytes recruit to the abluminal EC tube surface within these tunnel spaces, and work together to assemble the vascular basement membrane matrix. These processes occur under serum-free conditions in 3D collagen or fibrin matrices and in response to five key growth factors which are stem cell factor, interleukin-3, stromal-derived factor-1α, fibroblast growth factor-2 and insulin. In addition, we identified a key role for EC-derived platelet-derived growth factor-BB and heparin-binding epidermal growth factor in pericyte recruitment and proliferation to promote EC-pericyte tube co-assembly and vascular basement membrane matrix deposition. A molecular understanding of capillary morphogenesis and maturation should lead to novel therapeutic strategies to repair capillary dysfunction in major human disease contexts including cancer and diabetes.

Tissue Inhibitor Metalloproteinase-2 (TIMP-2)⋅IGF-Binding Protein-7 (IGFBP7) Levels Are Associated with Adverse Long-Term Outcomes in Patients with AKI

Tissue inhibitor metalloproteinase-2 (TIMP-2) and IGF-binding protein-7 (IGFBP7) have been validated for risk stratification in AKI. However, the association of urinary TIMP-2 and IGFBP7 with long-term outcomes is unknown. We evaluated the 9-month incidence of a composite end point of all-cause mortality or the need for RRT in a secondary analysis of a prospective observational international study of critically ill adults. Two predefined [TIMP-2]⋅[IGFBP7] cutoffs (0.3 for high sensitivity and 2.0 for high specificity) for the development of AKI were evaluated. Cox proportional hazards models were used to determine risk for the composite end point. Baseline [TIMP-2]⋅[IGFBP7] values were available for 692 subjects, of whom 382 (55.2%) subjects developed stage 1 AKI (defined by Kidney Disease Improving Global Outcomes guidelines) within 72 hours of enrollment and 217 (31.4%) subjects met the composite end point. Univariate analysis showed that [TIMP-2]⋅[IGFBP7]>2.0 was associated with increased risk of the composite end point (hazard ratio [HR], 2.11; 95% confidence interval [95% CI], 1.37 to 3.23; P<0.001). In a multivariate analysis adjusted for the clinical model, [TIMP-2]⋅[IGFBP7] levels>0.3 were associated with death or RRT only in subjects who developed AKI (compared with levels≤0.3: HR, 1.44; 95% CI, 1.00 to 2.06 for levels>0.3 to ≤2.0; P=0.05 and HR, 2.16; 95% CI, 1.32 to 3.53 for levels>2.0; P=0.002). In conclusion, [TIMP-2]⋅[IGFBP7] measured early in the setting of critical illness may identify patients with AKI at increased risk for mortality or receipt of RRT over the next 9 months.

Anti-angiogenic effects of Siegesbeckia glabrescens are mediated by suppression of the Akt and p70S6K-dependent signaling pathways

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of allergic and inflammatory diseases. In the present study, we report the effects and molecular mechanism of an ethanolic extract of SG on cell proliferation, migration and tube formation in vascular endothelial growth factor-A (VEGF-A)-treated human umbilical vein endothelial cells. SG treatment inhibited VEGF-A-stimulated endothelial cell proliferation through downregulation of cyclin D and upregulation of cyclin-dependent kinase inhibitors such as p27Kip1 and p21WAF1/Cip1. In addition, SG inhibited VEGF‑A-stimulated endothelial cell migration and tube formation. These anti-angiogenic activities of SG were mediated by inactivation of the Akt- and p70S6K-dependent signaling pathways. Collectively, our findings demonstrate the pharmacological roles and molecular mechanism of SG in regulating angiogenic responses and support further evaluation and development of SG as a potential therapeutic agent for the treatment and prevention of angiogenesis-related diseases including cancer.

Primary proximal tubule injury leads to epithelial cell cycle arrest, fibrosis, vascular rarefaction, and glomerulosclerosis

Tubular injury has a major etiological role in fibrosis. For many years, this relationship has been dominated by the perception that epithelial cells are transformed into myofibroblasts that proliferate and generate fibrotic matrix—the so-called epithelial-to-mesenchymal transition. Here we focus on mechanisms by which injury to the tubule results in fibrosis because of paracrine mechanisms. Specific injury to the proximal tubule results in inflammation, reversible injury, and adaptive repair if the insult is mild, self-limited in time, and occurs in a background of a normal kidney. Repeated injury, in contrast, leads to maladaptive repair with sustained tubule injury, chronic inflammation, proliferation of interstitial myofibroblasts, vascular rarefaction, interstitial fibrosis, and glomerular sclerosis. During the maladaptive repair process after the renal insult, many tubular cells become arrested in the G2/M phase of the cell cycle. This results in activation of the DNA repair response with the resultant synthesis and secretion of pro-fibrotic factors. Pharmacologic interventions that enhance the movement through G2/M or facilitate apoptosis of cells that otherwise would be blocked in G2/M may reduce the development of fibrosis after kidney injury and reduce the progression of chronic kidney disease.

Validation of cell-cycle arrest biomarkers for acute kidney injury after pediatric cardiac surgery

Background

The lack of early biomarkers for acute kidney injury (AKI) seriously inhibits the initiation of preventive and therapeutic measures for this syndrome in a timely manner. We tested the hypothesis that insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2), both inducers of G1 cell cycle arrest, function as early biomarkers for AKI after congenital heart surgery with cardiopulmonary bypass (CPB).

Methods

We prospectively studied 51 children undergoing cardiac surgery with CPB. Serial urine samples were analyzed for [TIMP-2]•[IGFBP7]. The primary outcome measure was AKI defined by the pRIFLE criteria within 72 hours after surgery.

Results

12 children (24%) developed AKI within 1.67 (SE 0.3) days after surgery. Children who developed AKI after cardiac surgery had a significant higher urinary [TIMP-2]•[IGFBP7] as early as 4 h after the procedure, compared to children who did not develop AKI (mean of 1.93 ((ng/ml)²/1000) (SE 0.4) vs 0.47 ((ng/ml)²/1000) (SE 0.1), respectively; p<0.05). Urinary [TIMP-2]•[IGFBP7] 4 hours following surgery demonstrated an area under the receiver-operating characteristic curve of 0.85. Sensitivity was 0.83, and specificity was 0.77 for a cutoff value of 0.70 ((ng/ml)²/1000).

Conclusions

Urinary [TIMP-2]•[IGFBP7] represent sensitive, specific, and highly predictive early biomarkers for AKI after surgery for congenital heart disease.

Trial Registration

www.germanctr.de/, DRKS00005062

Pro-angiogenic effects of Carthami Flos whole extract in human microvascular endothelial cells in vitro and in zebrafish in vivo

AIM

Carthami Flos (CF) is a Chinese herb traditionally used for cardiovascular disease and bone injury in China with pharmacological effects on improving blood circulation. The aim of this study was to investigate the angiogenic potential of CF whole extract (extracted by boiling with water, followed by ethanol) and the underlying mechanisms in human microvascular endothelial cells (HMEC-1) in vitro and in transgenic TG(fli1:EGFP)(y1)/+(AB) zebrafish with transgenic endothelial cells expressing EGFP (Enhanced Green Fluorescent Protein) in vivo.

METHODS

Effects of CF whole extract on cell proliferation, migration and tube formation in HMEC-1 cells in vitro were detected by MTT assay, wound healing assay and tube formation assay. Its angiogenic effect in zebrafish was investigated by monitoring the sprout number in the sub-intestinal vessel (SIV), and the underlying mechanisms were tested by quantitative real-time PCR.

RESULTS

CF whole extract increased cell proliferation, migration and tube formation in vitro in HMEC-1 cells. Its angiogenic effect was also confirmed in vivo in zebrafish by increasing the sprout number in the SIV. As determined by quantitative real-time PCR, CF whole extract up-regulated the expression of angiogenesis-related genes in zebrafish, including angiogenic and its associated growth factors and receptors (e.g. IGF1, CTGF, NRP2, and VEGFR3), transcription factor (e.g. HIF1A), matrix degradation and endothelial cell migration-related factors (e.g. MMP2, MMP9, TIMP2, PLG and PLAU), cell adhesion molecules (e.g. ITGAV, ITGB3, beta-catenin and PECAM1), tubule formation factors (e.g. ANGPT1, TIE-2, PDGFR-B, CDH5, S1PR1, FGF2, Shh, and TGFRB1), and blood vessel maturation/formation factor (e.g. Ephrin B2).

CONCLUSIONS

CF whole extract increased angiogenesis in HMEC-1 cells in vitro and in zebrafish in vivo with multiple mechanisms.

No correlation between TIMP2 -418 G>C polymorphism and increased risk of cancer: evidence from a meta-analysis

Aim

Tissue inhibitor of metalloproteinase (TIMP2) is involved in the regulation of matrix metalloproteinase 2 (MMP2) and shown to implicate in cancer development and progression. The results from the published studies based on the association between TIMP2 -418 G>C polymorphism and cancer risk are inconsistent. In this meta-analysis, we aimed to evaluate the potential association between TIMP2 -418 G>C polymorphism and cancer risk.

Methodology

We searched PubMed (Medline) and EMBASE web databases to cover all studies based on relationship of TIMP2 -418 G>C polymorphism and risk of cancer until October 2013. The meta-analysis was performed for selected case-control studies and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all genetic models.

Results

A total of 2225 cancer cases and 2532 controls were included from ten eligible case-control studies. Results from overall pooled analysis suggested no evidence of significant risk between TIMP2 -418 G>C polymorphism and cancer risk in any of the genetic models, such as, allele (C vs. G: OR = 1.293, 95% CI = 0.882 to 1.894, p = 0.188), homozygous (CC vs. GG: OR = 0.940, 95% CI = 0.434 to 2.039, p = 0.876), heterozygous (GC vs. GG: OR = 1.397, 95% CI = 0.888 to 2.198, p = 0.148), dominant (CC+GC vs. GG: OR = 1.387, 95% CI = 0.880 to 2.187, p = 0.159) and recessive (CC vs. GG+GC: OR = 0.901, 95% CI = 0.442 to 1.838, p = 0.774) models. No evidence of publication bias was detected during the analysis.

Conclusions

The present meta-analysis suggests that the TIMP2 -418 G>C polymorphism may not be involved in predisposing risk factor for cancer in overall population. However, future larger studies with group of populations are needed to analyze the possible correlation.

Broussonetia kazinoki modulates the expression of VEGFR-2 and MMP-2 through the inhibition of ERK, Akt and p70S6K‑dependent signaling pathways: Its implication in endothelial cell proliferation, migration and tubular formation

Broussonetia kazinoki (BK) has been used as a traditional medicine to improve vision, as well as for inflammatory and infectious diseases. In the present study, we investigated the effects and molecular mechanism of the ethanolic extract of BK on cell proliferation, migration and tubular formation in vascular endothelial growth factor-A (VEGF-A)-treated human umbilical vein endothelial cells. BK treatment inhibited VEGF-A-stimulated endothelial cell proliferation through the downregulation of cell cycle-related proteins including cyclin-dependent kinases and cyclins. Moreover, BK treatment suppressed cell migration and tubular formation in response to VEGF-A. These anti-angiogenic activities of BK were associated with the inactivation of mitogenic signaling pathways including extracellular signal-regulated kinase, Akt and p70S6K, and the subsequent downregulation of VEGFR-2 and matrix metalloproteinase-2. Taken together, these findings suggest further evaluation and development of BK as a potential therapeutic agent for the treatment and prevention of angiogenesis-related diseases including cancer.

Candidate prognostic markers in breast cancer: focus on extracellular proteases and their inhibitors

The extracellular matrix (ECM) is the complex network of proteins that surrounds cells in multicellular organisms. Due to its diverse nature and composition, the ECM has a multifaceted role in both normal tissue homeostasis and pathophysiology. It provides structural support, segregates tissues from one another, and regulates intercellular communication. Furthermore, the ECM sequesters a wide range of growth factors and cytokines that may be released upon specific and well-coordinated cues. Regulation of the ECM is performed by the extracellular proteases, which are tasked with cleaving and remodeling this intricate and diverse protein matrix. Accordingly, extracellular proteases are differentially expressed in various tissue types and in many diseases such as cancer. In fact, metastatic dissemination of tumor cells requires degradation of extracellular matrices by several families of proteases, including metalloproteinases and serine proteases, among others. Extracellular proteases are emerging as strong candidate cancer biomarkers for aiding and predicting patient outcome. Not surprisingly, inhibition of these protumorigenic enzymes in animal models of metastasis has shown impressive therapeutic effects. As such, many of these proteolytic inhibitors are currently in various phases of clinical investigation. In addition to direct approaches, aberrant expression of extracellular proteases in disease states may also facilitate the selective delivery of other therapeutic or imaging agents. Herein, we outline extracellular proteases that are either bona fide or probable prognostic markers in breast cancer. Furthermore, using existing patient data and multiple robust statistical analyses, we highlight several extracellular proteases and associated inhibitors (eg, uPA, ADAMs, MMPs, TIMPs, RECK) that hold the greatest potential as clinical biomarkers. With the recent advances in high-throughput technology and targeted therapies, the incorporation of extracellular protease status in breast cancer patient management may have a profound effect on improving outcomes in this deadly disease.