Tissue inhibitor of metalloproteinases-1 stimulates gene expression in MDA-MB-435 human breast cancer cells by means of its ability to inhibit metalloproteinases

Cerebrospinal fluid peptides as potential Parkinson disease biomarkers: a staged pipeline for discovery and validation

Finding robust biomarkers for Parkinson disease (PD) is currently hampered by inherent technical limitations associated with imaging or antibody-based protein assays. To circumvent the challenges, we adapted a staged pipeline, starting from our previous proteomic profiling followed by high-throughput targeted mass spectrometry (MS), to identify peptides in human cerebrospinal fluid (CSF) for PD diagnosis and disease severity correlation. In this multicenter study consisting of training and validation sets, a total of 178 subjects were randomly selected from a retrospective cohort, matching age and sex between PD patients, healthy controls, and neurological controls with Alzheimer disease (AD). From ∼14,000 unique peptides displaying differences between PD and healthy control in proteomic investigations, 126 peptides were selected based on relevance and observability in CSF using bioinformatic analysis and MS screening, and then quantified by highly accurate and sensitive selected reaction monitoring (SRM) in the CSF of 30 PD patients versus 30 healthy controls (training set), followed by diagnostic (receiver operating characteristics) and disease severity correlation analyses. The most promising candidates were further tested in an independent cohort of 40 PD patients, 38 AD patients, and 40 healthy controls (validation set). A panel of five peptides (derived from SPP1, LRP1, CSF1R, EPHA4, and TIMP1) was identified to provide an area under curve (AUC) of 0.873 (sensitivity = 76.7%, specificity = 80.0%) for PD versus healthy controls in the training set. The performance was essentially confirmed in the validation set (AUC = 0.853, sensitivity = 82.5%, specificity = 82.5%). Additionally, this panel could also differentiate the PD and AD groups (AUC = 0.990, sensitivity = 95.0%, specificity = 97.4%). Furthermore, a combination of two peptides belonging to proteins TIMP1 and APLP1 significantly correlated with disease severity as determined by the Unified Parkinson's Disease Rating Scale motor scores in both the training (r = 0.381, p = 0.038)j and the validation (r = 0.339, p = 0.032) sets. The novel panel of CSF peptides, if validated in independent cohorts, could be used to assist in clinical diagnosis of PD and has the potential to help monitoring or predicting disease progression.

Identification of miR-1293 potential target gene: TIMP-1

Tissue inhibitor of metalloproteinases 1 (TIMP-1) is a glycosylated protein with multiple activities in the regulation of biological processes, such as cell growth and apoptosis as well as tumor invasion and metastasis. Bioinformatics analysis using TargetScan and miRanda suggested tissue inhibitors of TIMP-1 are among the targets of miR-1293. To confirm this, we cloned both wild-type and mutant TIMP-1 3'UTR fragments by overlap extension PCR, constructed the recombinant plasmids pGL3-TIMP-1-wt, -mut, and pcDNA 3.1(+)/TIMP-1-CDS and, respectively, co-transfected them into 293T cells with the miR-1293 inhibitor, mimics or the miR inhibitor-NC using a BTX ECM 2001 square-wave electroporator. We used a luciferase assay to investigate binding of miR-1293 to the 3'UTR of TIMP-1. Effects on the levels of the TIMP-1 protein were analyzed by Western blot experiments. The luciferase reporter assay showed a statistically significant (P < 0.05) upregulation of activity. Western blot analysis showed a significant increase of expression of the TIMP-1 gene co-transfected with the miR-1293 inhibitor, and demonstrated direct binding of miR-1293 to the 3'UTR of TIMP-1. In this study, we identified TIMP-1 as a novel direct target for miR-1293, which provides the basis for further study of the multifunctional mechanisms of miR-1293 and TIMP-1 in the regulation of a variety of diseases.

Tissue inhibitor of metalloproteinase-1 promotes NIH3T3 fibroblast proliferation by activating p-Akt and cell cycle progression

Tissue inhibitor of metalloproteinase-1 (TIMP-1) plays various roles in cell growth in different cell types. However, few studies have focused on TIMP-1's effect on fibroblast cells. In this study, we investigated the effects of TIMP-1 overexpression on NIH3T3 fibroblast proliferation and potential transduction signaling pathways involved. Overexpression of TIMP-1, by transfection of the pLenti6/V5-DESTTIMP-1 plasmid, significantly promoted NIH3T3 proliferation as determined by the BrdU array. Neither 5 nor 15 nM GM6001 (matrix metalloproteinase system inhibitor) affected NIH3T3 proliferation, but 45 nM GM6001 inhibited proliferation. TIMP-1 overexpression activated the p-Akt pathway, but not the p-ERK or p-p38 pathway. In TIMP-1-transfected cells, cyclinD1 was upregulated and p21CIP1 and p27(KIP1) were downregulated, which promoted cell entry into the S and G2/M phases. The PI3-K inhibitor LY294002 abolished the TIMP-1-induced effects. Overexpression of intracellular TIMP-1 stimulated NIH3T3 fibroblast proliferation in a matrix metalloproteinase (MMP)-independent manner by activating the p-Akt pathway and related cell cycle progression.

Cellular stress induced by resazurin leads to autophagy and cell death via production of reactive oxygen species and mitochondrial impairment

Mitochondrial bioenergetics and reactive oxygen species (ROS) often play important roles in cellular stress mechanisms. In this study we investigated how these factors are involved in the stress response triggered by resazurin (Alamar Blue) in cultured cancer cells. Resazurin is a redox reactive compound widely used as reporter agent in assays of cell biology (e.g. cell viability and metabolic activity) due to its colorimetric and fluorimetric properties. In order to investigate resazurin-induced stress mechanisms we employed cells affording different metabolic and regulatory phenotypes. In HL-60 and Jurkat leukemia cells resazurin caused mitochondrial disintegration, respiratory dysfunction, reduced proliferation, and cell death. These effects were preceded by a burst of ROS, especially in HL-60 cells which were also more sensitive and contained autophagic vesicles. Studies in Rho(0) cells (devoid of mitochondrial DNA) indicated that the stress response does not depend on the rates of mitochondrial respiration. The anti-proliferative effect of resazurin was confirmed in native acute myelogenous leukemia (AML) blasts. In conclusion, the data suggest that resazurin triggers cellular ROS production and thereby initiates a stress response leading to mitochondrial dysfunction, reduced proliferation, autophagy, and cell degradation. The ability of cells to tolerate this type of stress may be important in toxicity and chemoresistance.

TIMP-1 overexpression promotes tumorigenesis of MDA-MB-231 breast cancer cells and alters expression of a subset of cancer promoting genes in vivo distinct from those observed in vitro

TIMP-1 (Tissue inhibitor of matrix metalloproteinase-1) is typically associated with inhibition of matrix metalloproteinases (MMP) induced invasion. However, TIMP-1 is overexpressed in many malignancies and is associated with poor prognosis in breast cancer. The mechanisms by which TIMP-1 promotes tumorigenesis are unclear. Reduced levels of TIMP-1 mediated by shRNA in MDA-MB-231 breast cancer cells had no effect on cellular physiology in vitro or tumor growth in SCID mice compared to vector control MDA-MB-231 cells. However, overexpression of TIMP-1 in MDA-MB-231 cells resulted in inhibition of cell invasion and enhanced phosphorylation of p38 MAPK and AKT in vitro. Additionally, treatment of parental MDA-MB-231 cells with purified TIMP-1 protein led to activation of p38 MAPK and MKK 3/6. cDNA array analysis demonstrated that high expression of TIMP-1 in MDA-MB-231 cells resulted in alterations in expression of approximately 200 genes, 1.5 fold or greater compared to vector control cells (P < 0.1). Real-time RT-PCR confirmed changes in expression of several genes associated with cancer progression including DAPK1, FGFR4 and MAPK13. In vivo, high TIMP-1 expression induced tumor growth in SCID mice compared to vector control cells and increased tumor vessel density. Affymetrix array analysis of vector control and TIMP-1 MDA-MB-231 xenograft tumors revealed that TIMP-1 altered expression of approximately 600 genes in vivo, including MMP1, MMP13, S100A14, S100P, Rab25 and ID4. These combined observations suggest that the effects of TIMP-1 differ significantly in a 2-D environment compared to the 3-D environment and that TIMP-1 stimulates tumor growth.

Identification of the first intragenic deletion of the PITX2 gene causing an Axenfeld-Rieger Syndrome: case report

BACKGROUND

Axenfeld-Rieger syndrome (ARS) is characterized by bilateral congenital abnormalities of the anterior segment of the eye associated with abnormalities of the teeth, midface, and umbilicus. Most cases of ARS are caused by mutations in the genes encoding PITX2 or FOXC1. Here we describe a family affected by a severe form of ARS.

CASE PRESENTATION

Two members of this family (father and daughter) presented with typical ARS and developed severe glaucoma. The ocular phenotype was much more severe in the daughter than in the father. Magnetic resonance imaging (MRI) detected an aggressive form of meningioma in the father. There was no mutation in the PITX2 gene, determined by exon screening. We identified an intragenic deletion by quantitative genomic PCR analysis and characterized this deletion in detail.

CONCLUSION

Our findings implicate the first intragenic deletion of the PITX2 gene in the pathogenesis of a severe form of ARS in an affected family. This study stresses the importance of a systematic search for intragenic deletions in families affected by ARS and in sporadic cases for which no mutations in the exons or introns of PITX2 have been found. The molecular genetics of some ARS pedigrees should be re-examined with enzymes that can amplify medium and large genomic fragments.

Differential proinflammatory and angiogenesis-specific cytokine production in human pulmonary endothelial cells, HPMEC-ST1.6R infected with dengue-2 and dengue-3 virus

In this study, the ability of dengue virus serotypes 2 (DENV-2) and 3 (DENV-3) to infect and induce increased production of proinflammatory cytokines in a pulmonary endothelial cell line (HPMEC-ST1.6R) was investigated. This cell line exhibits the major constitutive and inducible endothelial cell characteristics, as well as angiogenic response. DENV-2 and DENV-3 infection was confirmed by an observed cytopathic effect (CPE), as well as RT-PCR and immunofluorescence assays. Increases in Th-1 and Th-2 cytokines IL-4, IL-8, IL-6, IL-10, GM-CSF, INF-gamma, and tumor necrosis factor (TNF-alpha) within DENV-2- and DENV-3-infected cells were demonstrated using a microbead-based Bio-plex assay. Proinflammatory cytokine increases and the expression of a potent angiogenic inducer protein, VEGF were confirmed by dot-blot analysis using the TranSignal Human Angiogenesis Antibody Array. Dengue virus-infected HPMEC-ST1.6R cells exhibited an elongated cytoplasmic morphology, possibly representing a response to VEGF and activation of angiogenesis. The increased levels of Th-1 cytokines and VEGF in DENV-2 virus infected-HPMEC-ST1.6R could be distinguished from those infected by DENV-3. This suggests that cytokine patterns associated with DENV infections may be serotype and strain-specific. The experimental approaches described here could be developed further into a useful diagnostic tool for the characterization of dengue hemorrhagic fever cases, leading to enhancement of treatment therapy.

Therapeutic potential of S179D prolactin – from prostate cancer to angioproliferative disorders: the first selective prolactin receptor modulator

Increasing evidence suggests an important role for autocrine/paracrine prolactin in breast and prostate cancers and other disease states. Prolactin production in these extrapituitary sites is not governed by dopamine agonists, a finding that has spurred the production of prolactin receptor antagonists. This review focuses on one such antagonist, S179D prolactin, which was produced by mimicking a natural antagonist, phosphorylated prolactin. S179D prolactin is a very effective growth antagonist, partly because it inhibits signalling from unmodified prolactin and partly because it produces its own intracellular signal. This signal results in cell differentiation, cell-cycle arrest or apoptosis depending on dose, duration of treatment and cellular context. S179D prolactin is also a potent antiangiogenic and initial studies have shown it to be a potent anti-inflammatory agent. In light of these additional modes of action, it is suggested that S179D prolactin should now be more aptly referred to as a selective prolactin receptor modulator.

Novel functions of TIMPs in cell signaling

Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of matrix metalloproteinases (MMPs) and the balance between MMPs/TIMPs regulates the extracellular matrix (ECM) turnover and remodeling during normal development and pathogenesis. Increasing evidence indicates a much more complex role for TIMPs during tumor progression and angiogenesis, in addition to their regulation of MMP-mediated ECM degradation. In this article, we review both the MMP-dependent and -independent actions of TIMPs for the regulation of cell death, cell proliferation, and angiogenesis, with a particular emphasis on TIMP-1 in the regulation of tetraspanin/integrin-mediated cell survival signal transduction pathways.