Tissue inhibitor of metalloproteinase-4 deletion in mice impacts maternal cardiac function during pregnancy and postpartum

Reversible physiological cardiac hypertrophy of the maternal heart occurs during pregnancy and involves extracellular matrix (ECM) remodeling. Previous mouse studies revealed that changes in ECM molecules accompany functional changes in the left ventricle (LV) during late pregnancy and postpartum. We evaluated the effect of global Timp4 deletion in female mice on LV functional parameters and ECM molecules during pregnancy and the postpartum period. Heart weights normalized to tibia lengths were increased in Timp4 knockout (Timp4 KO) virgin, pregnant, and postpartum day 2 mice compared with wild types. Serial echocardiography performed on pregnancy days 10, 12, and 18 and postpartum days (ppds) 2, 7, 14, 21, and 28 revealed that both wild-type and Timp4 KO mice increased end systolic and end diastolic volumes (ESV, EDV) by mid to late pregnancy compared with virgins, with EDV changes persisting through the postpartum period. When compared with wild types, Timp4 KO mice exhibited higher ejection fractions in virgins, at pregnancy days 10 and 18 and ppd2 and ppd14. High-molecular weight forms of COL1A1 and COL3A1 proteins in LV were greater in Timp4 KO virgins, and COL1A1 was higher in late pregnancy and on ppd2 compared with wild types. With exceptions, Timp4 KO mice during late pregnancy and the early postpartum period were able to maintain stroke volume similar to wild-type mice through increased ejection fraction. Although TIMP4 deletion in females exhibited altered ECM molecules, it did not adversely affect cardiac function during first pregnancies and lactation.NEW & NOTEWORTHY Pregnancy and lactation increase volume load on the heart. Defects in cardiac remodeling during pregnancy and postpartum can result in peripartum cardiomyopathy. TIMPs participate in cardiac remodeling. The present study reports the cardiac function in Timp4 knockout adult female mice during pregnancy and lactation. Timp4 knockout females at many time points have higher ejection fraction to maintain stroke volume. Global deletion of Timp4 was not detrimental to maternal heart function during first pregnancies and lactation.

CHOP Increases TRIB3-Dependent miR-208 Expression to Potentiate Vascular Smooth Muscle Cell Proliferation and Migration by Downregulating TIMP3 in Atherosclerosis

BACKGROUND

C/EBP homologous protein (CHOP) has been identified as a suitable therapeutic target to combat atherosclerosis but the mechanism has not been fully studied. Here, we sought to define the role and underlying mechanism of CHOP in atherosclerosis.

METHODS

Mouse models of atherosclerosis in ApoE-/- mice were established by high-fat feeding, where miR-208 expression was determined. Then atherosclerotic plaque tissues were isolated from the model mice. Loss- and gain-function assays were performed on trypsinized vascular smooth muscle cells (VSMCs) to test the in vitro effect of CHOP in controlling the tribbles homologue 3 (TRIB3)/microRNA-208 (miR-208)/tissue inhibitor of metalloproteinases-3 (TIMP3) axis in atherosclerosis by determining cell proliferation and migration as well as blood lipid levels. Moreover, expression of α-smooth muscle actin (α-SMA) and type I collagen expression was determined using immunofluorescence staining to assess plaque stability in mice.

RESULTS

miR-208 expression was elevated in atherosclerosis samples and miR-208 overexpression promoted proliferation and migration of VSMCs but diminished plaque stability in mice. TIMP3 was targeted by miR-208, which could be abrogated by upregulation of TIMP3. In addition, CHOP increased TRIB3 expression to upregulate miR-208 and to downregulate TIMP3, which potentiated VSMC proliferation and migration in vitro and in vivo.

CONCLUSION

Taken together, inhibition of CHOP may inhibit the proliferation and migration of VSMCs as well as reduce the levels of TC, TG, and LDL-C but increase the level of HDL-C through the TRIB3/miR-208/TIMP3 axis, thereby inhibiting the progression of atherosclerosis.

The role of matrix metalloproteinases in patients with pulmonary hypertension: data from a prospective study

BACKGROUND

Despite several therapies, pulmonary hypertension (PH) is still a severe disease which can lead to right heart failure. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are involved in cardiac and vascular remodeling in PH. Therefore, these biomarkers play an important role in PH patients. This study investigated whether TIMP-4, MMP-2, and N-terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) plasma levels are useful in assessing the severity of PH and other clinical or echocardiographic parameters.

METHODS

The concentrations of MMP-2, TIMP-4, and NT-proBNP in 68 PH patients were compared with those of 12 controls without PH. All patients underwent a physical examination, echocardiography, and were checked for the presence of cardiovascular risk factors; also, plasma concentrations of MMP-2, TIMP-4, NT-proBNP, total cholesterol, and triglycerides were determined.

RESULTS

In PH patients, significantly elevated plasma levels of TIMP-4 (PH: 2877.99 ± 1363.78 pg/ml, control: 2028.38 ± 762.67 pg/ml, p = 0.0068) and NT-proBNP ( PH: 2405.00 pg/ml-5423.47 ± 6703.38 pg/ml, control: 411.0000 pg/ml-421.75 ± 315.37 pg/ml, p = 0.01) were detected. We also observed that MMP-2 and NT-proBNP were significantly increased in patients with higher WHO functional class (p = 0.001 for MMP-2, p = 0.008 for NT-proBNP), higher pressure in the pulmonary artery (p = 0.002 for MMP-2, p = 0.001 for NT-proBNP), and more severe tricuspid regurgitation (p = 0.001 for MMP-2, p = 0.009 for NT-proBNP). TIMP-4 was elevated in patients with more severe pressure in the pulmonary artery (p = 0.006).

CONCLUSIONS

The plasma levels of TIMP-4 and NT-proBNP are higher in PH patients. MMP-2 and NT-proBNP correlates with different PH parameters severity (WHO functional class, sPAP severity, TV regurgitation severity). Therefore, plasmatic levels of MMP-2 and NT-proBNP at this kind of patients reflect disease severity and may have a prognostic role. MMP-2 can help assess the beneficial effects of PH pharmacotherapy on tissue remodeling. These remodeling biomarkers may not have a diagnostic value but they have the potential to predict survival. Nevertheless, a greater understanding of the involvement of MMPs in PH is mandatory to further explore the prognostic role and the possibilities of therapeutic MMP inhibition in PH.

MicroRNA-146b-5p promotes atrial fibrosis in atrial fibrillation by repressing TIMP4

Alteration of tissue inhibitors of matrix metalloproteinases (TIMP)/matrix metalloproteinases (MMP) associated with collagen upregulation has an important role in sustained atrial fibrillation (AF). The expression of miR-146b-5p, whose the targeted gene is TIMPs, is upregulated in atrial cardiomyocytes during AF. This study was to determine whether miR-146b-5p could regulate the gene expression of TIMP4 and the contribution of miRNA to atrial fibrosis in AF. Collagen synthesis was observed after miR-146b-5p transfection in human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs)-fibroblast co-culture cellular model in vitro. Furthermore, a myocardial infarction (MI) mouse model was used to confirm the protective effect of miR-146b-5p downregulation on atrial fibrosis. The expression level of miR-146b-5p was upregulated, while the expression level of TIMP4 was downregulated in the fibrotic atrium of canine with AF. miR-146b-5p transfection in hiPSC-aCMs-fibroblast co-culture cellular model increased collagen synthesis by regulating TIMP4/MMP9 mediated extracellular matrix proteins synthesis. The inhibition of miR-146b-5p expression reduced the phenotypes of cardiac fibrosis in the MI mouse model. Fibrotic marker MMP9, TGFB1 and COL1A1 were significantly downregulated, while TIMP4 was significantly upregulated (at both mRNA and protein levels) by miR-146b-5p inhibition in cardiomyocytes of MI heart. We concluded that collagen fibres were accumulated in extracellular space on miR-146b-5p overexpressed co-culture cellular model. Moreover, the cardiac fibrosis induced by MI was attenuated in antagomiR-146 treated mice by increasing the expression of TIMP4, which indicated that the inhibition of miR-146b-5p might become an effective therapeutic approach for preventing atrial fibrosis.

CD24 gene inhibition and TIMP-4 gene upregulation by Imperata cylindrica's root extract prevents metastasis of CaSki cells via inhibiting PI3K/Akt/snail signaling pathway and blocking EMT

ETHNOPHARMACOLOGICAL RELEVANCE

Imperata cylindrica (L.) Raeusch (Gramineae) is a medicinal spice traditionally used in the treatment of hypertension and cancer.

AIM OF THE STUDY

To assess the anti-metastatic potential of the methanol extract of I. cylindrica roots and determined its mechanisms of action.

MATERIAL AND METHODS

The growth inhibition activity of I. cylindrica root extract in vitro and in vivo in human cervical cancer. The scratch assay and Boyden Chamber assay were used to determine the anti-migrative and anti-invasion actions of the plant extract. The whole-genome gene expression profiling using RNA-Seq was performed to determine the differentially expressed genes in CaSki cells after exposure to I. cylindrica to identify its targeted genes related to metastasis. Using protein analysis (western blotting) and gene expression analysis (RTqPCR), the targeted pathways of the key genes that were initially identified with RNA-Seq, were evaluated.

RESULTS

I. cylindrica extract showed dose-dependent cytotoxicity in vitro and in vivo in mice bearing tumors. Furthermore, I. cylindrica root extract significantly inhibited cell migration and cell invasion. After the genome-wide transcriptome analysis, we found that important genes involved in cancer progression and metastasis of cervical cancer, that is, CD24 and TIMP-4 were significantly downregulated and upregulated, respectively. Moreover, I. cylindrica root extract significantly inhibited the PI3/AKT/Snail signaling pathway and blocked the EMT of CaSki cells.

CONCLUSION

These findings provide an anti-metastatic mechanism of action of I. cylindrica root extract toward the human cervical cancer suggesting that this plant maybe developed into selective chemotherapy.

Loss of TIMP4 (Tissue Inhibitor of Metalloproteinase 4) Promotes Atherosclerotic Plaque Deposition in the Abdominal Aorta Despite Suppressed Plasma Cholesterol Levels

[Figure: see text].

Atrial matrix remodeling in atrial fibrillation patients with aortic stenosis

BACKGROUND

This study aimed to evaluate atrium extracellular matrix remodeling in atrial fibrillation (AF) patients with severe aortic stenosis, through histological fibrosis quantification and extracellular matrix gene expression analysis, as well as serum quantification of selected protein targets.

METHODS

A posthoc analysis of a prospective study was performed in a cohort of aortic stenosis patients. Between 2014 and 2019, 56 patients with severe aortic stenosis submitted to aortic valve replacement surgery in a tertiary hospital were selected.

RESULTS

Fibrosis was significantly increased in the AF group when compared to sinus rhythm (SR) patients (p = 0.024). Moreover, cardiomyocyte area was significantly higher in AF patients versus SR patients (p = 0.008). Conversely, collagen III gene expression was increased in AF patients (p = 0.038). TIMP1 was less expressed in the atria of AF patients. MMP16/TIMP4 ratio was significantly decreased in AF patients (p = 0.006). TIMP1 (p = 0.004) and TIMP2 (p = 0.012) were significantly increased in the serum of AF patients. Aortic valve maximum (p = 0.0159) and mean (p = 0.031) gradients demonstrated a negative association with serum TIMP1.

CONCLUSIONS

Atrial fibrillation patients with severe aortic stenosis present increased atrial fibrosis and collagen type III synthesis, with extracellular matrix remodelling demonstrated by a decrease in the MMP16/TIMP4 ratio, along with an increased serum TIMP1 and TIMP2 proteins.

The retinal pigment epithelium in Sorsby Fundus Dystrophy shows increased sensitivity to oxidative stress-induced degeneration

Sorsby Fundus Dystrophy (SFD) is a rare inherited autosomal dominant macular degeneration caused by specific mutations in TIMP3. Patients with SFD present with pathophysiology similar to the more common Age-related Macular Degeneration (AMD) and loss of vision due to both choroidal neovascularization and geographic atrophy. Previously, it has been shown that RPE degeneration in AMD is due in part to oxidative stress. We hypothesized that similar mechanisms may be at play in SFD. The objective of this study was to evaluate whether mice carrying the S179C-Timp3 mutation, a variant commonly observed in SFD, showed increased sensitivity to oxidative stress. Antioxidant genes are increased at baseline in the RPE in SFD mouse models, but not in the retina. This suggests the presence of a pro-oxidant environment in the RPE in the presence of Timp3 mutations. To determine if the RPE of Timp3 mutant mice is more susceptible to degeneration when exposed to low levels of oxidative stress, mice were injected with low doses of sodium iodate. The RPE and photoreceptors in Timp3 mutant mice degenerated at low doses of sodium iodate, which had no effect in wildtype control mice. These studies suggest that TIMP3 mutations may result in a dysregulation of pro-oxidant-antioxidant homeostasis in the RPE, leading to RPE degeneration in SFD.

Effect of Posaconazole in an in vitro model of cardiac fibrosis induced by Trypanosoma cruzi

Posaconazole (POS) is an inhibitor of ergosterol biosynthesis in clinical use for treating invasive fungal infections. POS has potent and selective anti-Trypanosoma cruzi activity and has been evaluated as a possible treatment for Chagas disease. Microtissues are a 3D culture system that has been shown to reproduce better tissue architecture and functionality than cell cultures in monolayer (2D). It has been used to evaluate chemotropic response as in vitro disease models. We previously developed an in vitro model that reproduces aspects of cardiac fibrosis observed in Chagas cardiomyopathy, using microtissues formed by primary cardiac cells infected by the T. cruzi, here called T. cruzi fibrotic cardiac microtissue (TCFCM). We also showed that the treatment of TCFCM with a TGF-β pathway inhibitor reduces fibrosis. Here, we aimed to evaluate the effect of POS in TCFCM, observing parasite load and molecules involved in fibrosis. To choose the concentration of POS to be used in TCFCM we first performed experiments in a monolayer of primary cardiac cell cultures and, based on the results, TCFCM was treated with 5 nM of POS for 96 h, starting at 144 h post-infection. Our previous studies showed that at this time the TCFCM had established fibrosis, resulting from T. cruzi infection. Treatment with POS of TCFCM reduced 50 % of parasite load as observed by real-time PCR and reduced markedly the fibrosis as observed by western blot and immunofluorescence, associated with a strong reduction in the expression of fibronectin and laminin (45 % and 54 %, respectively). POS treatment also changed the expression of proteins involved in the regulation of extracellular matrix proteins (TGF-β and TIMP-4, increased by 50 % and decreased by 58 %, respectively) in TCFCM. In conclusion, POS presented a potent trypanocidal effect both in 2D and in TCFCM, and the reduction of the parasite load was associated with a reduction of fibrosis in the absence of external immunological effectors.

IMPACT OF PERCUTANEOUS CORONARY INTERVENTION ON MARKERS OF MATRIX DEGRADATION AND ENDOTHELIAL-DEPENDENT MEDIATORS IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION AND DIABETES MELLITUS TYPE 2

Aim of study ‒ assess an impact of percutaneous coronary intervention on markers of matrix degradation (MMP-13, TIMP-4) and endothelial-dependent mediators (sVE-cadherin, ADMA) in patients with acute myocardial infarction and diabetes mellitus type 2. 110 patients with AMI were enrolled in the study, 70 patients had concomitant diabetes mellitus type 2. They were additionally divided into two subgroups depending on the treatment (percutaneous coronary intervention or conservative therapy). According to the obtained results, misbalance of extracellular matrix degradation markers (MMP-13, TIMP-4) and endothelial dysfunction (sVE-cadherin, ADMA) were revealed in patients with acute myocardial infarction. Performing of PCI procedure contributes to the significant lowering of MMP-13, sVE-cadherin, ADMA and increasing of TIMP-4 in diabetic patients. It was establishted that performing of percutaneous coronary intervention in patients with acute myocardial infarction and diabetes mellitus type 2 contributes to the maintenance of extracellular matrix that prevents myocardium remodeling and improvement of endothelial function.

CRN2 binds to TIMP4 and MMP14 and promotes perivascular invasion of glioblastoma cells

CRN2 is an actin filament binding protein involved in the regulation of various cellular processes including cell migration and invasion. CRN2 has been implicated in the malignant progression of different types of human cancer. We used CRN2 knock-out mice for analyses as well as for crossbreeding with a Tp53/Pten knock-out glioblastoma mouse model. CRN2 knock-out mice were subjected to a phenotyping screen at the German Mouse Clinic. Murine glioblastoma tissue specimens as well as cultured murine brain slices and glioblastoma cell lines were investigated by immunohistochemistry, immunofluorescence, and cell biological experiments. Protein interactions were studied by immunoprecipitation, pull-down, and enzyme activity assays. CRN2 knock-out mice displayed neurological and behavioural alterations, e.g. reduced hearing sensitivity, reduced acoustic startle response, hypoactivity, and less frequent urination. While glioblastoma mice with or without the additional CRN2 knock-out allele exhibited no significant difference in their survival rates, the increased levels of CRN2 in transplanted glioblastoma cells caused a higher tumour cell encasement of murine brain slice capillaries. We identified two important factors of the tumour microenvironment, the tissue inhibitor of matrix metalloproteinase 4 (TIMP4) and the matrix metalloproteinase 14 (MMP14, synonym: MT1-MMP), as novel binding partners of CRN2. All three proteins mutually interacted and co-localised at the front of lamellipodia, and CRN2 was newly detected in exosomes. On the functional level, we demonstrate that CRN2 increased the secretion of TIMP4 as well as the catalytic activity of MMP14. Our results imply that CRN2 represents a pro-invasive effector within the tumour cell microenvironment of glioblastoma multiforme.

Sorsby Fundus Dystrophy Mutation in Tissue Inhibitor of Metalloproteinase 3 (TIMP3) promotes Choroidal Neovascularization via a Fibroblast Growth Factor-dependent Mechanism

Choroidal neovascularization (CNV) leads to loss of vision in patients with Sorsby Fundus Dystrophy (SFD), an inherited, macular degenerative disorder, caused by mutations in the Tissue Inhibitor of Metalloproteinase-3 (TIMP3) gene. SFD closely resembles age-related macular degeneration (AMD), which is the leading cause of blindness in the elderly population of the Western hemisphere. Variants in TIMP3 gene have recently been identified in patients with AMD. A majority of patients with AMD also lose vision as a consequence of choroidal neovascularization (CNV). Thus, understanding the molecular mechanisms that contribute to CNV as a consequence of TIMP-3 mutations will provide insight into the pathophysiology in SFD and likely the neovascular component of the more commonly seen AMD. While the role of VEGF in CNV has been studied extensively, it is becoming increasingly clear that other factors likely play a significant role. The objective of this study was to test the hypothesis that basic Fibroblast Growth Factor (bFGF) regulates SFD-related CNV. In this study we demonstrate that mice expressing mutant TIMP3 (Timp3S179C/S179C) showed reduced MMP inhibitory activity with an increase in MMP2 activity and bFGF levels, as well as accentuated CNV leakage when subjected to laser injury. S179C mutant-TIMP3 in retinal pigment epithelial (RPE) cells showed increased secretion of bFGF and conditioned medium from these cells induced increased angiogenesis in endothelial cells. These studies suggest that S179C-TIMP3 may promote angiogenesis and CNV via a FGFR-1-dependent pathway by increasing bFGF release and activity.

The transition of tissue inhibitor of metalloproteinases from -4 to -1 induces aggressive behavior and poor patient survival in dedifferentiated liposarcoma via YAP/TAZ activation

Liposarcoma (LS) is the most common soft-tissue sarcoma. Dedifferentiated liposarcoma (DDLS) shows more aggressive biological behavior than that of well-differentiated liposarcoma (WDLS), so advanced therapeutic agents based on molecular mechanism are urgently needed. Here we show that tissue inhibitors of metalloproteinases (TIMPs) from TIMP-1 to TIMP-4 are differently expressed and regulate yes-associated protein (YAP)/transcriptional co-activator with PDZ binding motif (TAZ) in LS. Database analysis showed high TIMP-1 expression in DDLS patients correlating with poor prognosis, but high TIMP-4 expression in WDLS patients with better prognosis. Stable TIMP-1 knockdown inactivated YAP/TAZ and inhibited proliferation, colony formation and migration in DDLS cells, which was rescued by a constitutive active YAP. However, stable overexpression of TIMP-1 showed the opposite in WDLS cells. Stable TIMP-4 knockdown activated YAP/TAZ and promoted proliferation and migration in WDLS cells, which was suppressed by YAP/TAZ inhibitor (verteporfin) or knockdown of YAP/TAZ. Recombinant TIMP-4 showed opposite results in DDLS cells. These results indicate that dedifferentiation in LS shifts the expression of TIMPs from type 4 to type 1, inducing more aggressive behavior and poor prognosis through YAP/TAZ activation, which can be prognostic markers and therapeutic targets for LS patients.

Comparative Study of Cytokine Levels in Different Respiratory Samples in Mild-to-Moderate AECOPD Patients

BACKGROUND

Matrix metalloproteinase-12 (MMP-12) and Tissue inhibitor of metalloproteinase-4 (TIMP-4) play important roles in the pathophysiology of chronic obstructive pulmonary disease (COPD). Subjects of many previous studies were patients with severe and very severe COPD. However, there are comparatively few studies on patients with mild-to-moderate COPD. Our aim was to measure MMP-12 and TIMP-4 levels and to compare its levels in various materials in patients with mild-to-moderate acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We also compared which of the two materials of these biomarkers was better correlated with disease severity and DODE index.

METHODS

A total of 39 patients with AECOPD and 25 control subjects were enrolled in our study. MMP-12 and TIMP-4 in different respiratory samples were detected by ELISA.

RESULTS

Expression levels of MMP-12 in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) and TIMP-4 in BALF were significantly higher in AECOPD patients than that in healthy subjects (P < 0.001). However, there was no significant difference in TIMP-4 level in EBC of AECOPD patients compared to healthy subjects (P = 0.0527). The levels of MMP-12 in BALF and EBC and TIMP-4 in BAFL of AECOPD patients were significantly correlated with FEV1% predicted (P < 0.001). However, in AECOPD patients, there was no significant correlation between TIMP-4 levels in EBC and BODE index (r = 0.4175, P = 0.0559).

CONCLUSION

During mild-to-moderate AECOPD, the levels of MMP-12 and TIMP-4 in BALF were better correlated with FEV1% predicted and BODE index than that in EBC, indicating that they may be new target interventions for pharmacology to prevent and/or treat AECOPD.

Gene Expression in Intracranial Aneurysms-Comparison Analysis of Aneurysmal Walls and Extracranial Arteries with Real-Time Polymerase Chain Reaction and Immunohistochemistry

BACKGROUND

This study was aimed at evaluating the gene expression levels of 4 genes in the intracranial aneurysm wall and comparing them with extracranial arteries. The analysis was done using real-time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Also, a correlation of the differential genetic expression was done with various patient clinical and radiologic factors.

METHODS

The quantitative assessment of ribonucleic acid levels was done with RT-PCR and was validated with IHC. The genes studied were collagen 1A2 (COL1A2), tissue inhibitor of metalloproteinase 4 (TIMP4), cathepsin B (CTSB), and alpha-1 antitrypsin (α-1 AT). The analysis was done on 24 aneurysm sacs and superficial temporal/occipital artery samples from patients undergoing surgical clipping.

RESULTS

The mean fold change of COL1A2 in the aneurysm sample was 8.89, that of TIMP4 was 10.16, that of CTSB was 1.02, and that of α-1 AT was 1.46 when compared with normal control vessel on PCR. On semiquantitative IHC, COL1A2 was 94.44%, α-1 AT was 77.8% overexpressed, CTSB was positive in 50%, and the expression of TIMP4 was 94.4% underexpressed in aneurysmal walls. There was no statistically significant correlation between patient profile and gene expression.

CONCLUSIONS

On RT-PCR and IHC analysis, COL1A2 and α-1 AT were overexpressed, CTSB was marginally overexpressed, and TIMP4 had equivocal expression in the aneurysmal sac when compared with the normal extracranial vessel. This is the first study of its kind in the Indian population with the largest sample size on live human patients.

Upregulated long noncoding RNA Linc00261 in pre-eclampsia and its effect on trophoblast invasion and migration via regulating miR-558/TIMP4 signaling pathway

Pre-eclampsia (PE) is a leading cause of maternal and perinatal morbidity and mortality but the exact underlying mechanisms of PE pathogenesis remain elusive. Accumulated data suggested that the long noncoding RNAs (lncRNAs) play important roles in the pathogenesis of PE. The present study identified the changes of lncRNA Linc00261 in PE and its effects on trophoblasts invasion and migration. Our results showed that the expression of Linc00261 was upregulated in placental tissues of PE women compared with those of healthy pregnant women. Overexpression of Linc00261 suppressed cell invasion and migration, induced cell apoptosis, and caused cell-cycle arrest at G0 /G1 phase of HTR-8/SVneo cells; while knockdown of Linc00261 had the opposite effects on the HTR-8/SVneo cells. Mechanistic studies showed Linc00261 functioned as a competing endogenous RNA for miR-558 in HTR-8/SVneo cells, and miR-558 was negatively regulated by Linc00261. The expression level of miR-558 in the PE group was significantly lower than the control group, and the expression level of Linc00261 was negatively correlated with the expression level of miR-558 in the placental tissues of women with PE. Furthermore, miR-558 was found to negatively regulate the expression of TIMP metallopeptidase inhibitor 4 (TIMP4) via targeting the 3' untranslated region in the HTR-8/SVneo cells. Overexpression of miR-558 increased HTR-8/SVneo cell invasion and migration, which was attenuated by TIMP4 overexpression. More importantly, both overexpression of miR-558 and knockdown of TIMP4 partially reversed the suppressive effects of Linc00261 overexpression on cell invasion and migration of HTR-8/SVneo cells. Collectively, our results for the first time showed the upregulation of Linc00261 in the placental tissues of severe PE patients. The mechanistic results indicated that Linc00261 exerted the suppressive effects on the trophoblast invasion and migration via targeting miR-558/TIMP4 axis, which may involve in the pathogenesis of PE.

Proteomic discovery of substrates of the cardiovascular protease ADAMTS7

The protease ADAMTS7 functions in the extracellular matrix (ECM) of the cardiovascular system. However, its physiological substrate specificity and mechanism of regulation remain to be explored. To address this, we conducted an unbiased substrate analysis using terminal amine isotopic labeling of substrates (TAILS). The analysis identified candidate substrates of ADAMTS7 in the human fibroblast secretome, including proteins with a wide range of functions, such as collagenous and noncollagenous extracellular matrix proteins, growth factors, proteases, and cell-surface receptors. It also suggested that autolysis occurs at Glu-729-Val-730 and Glu-732-Ala-733 in the ADAMTS7 Spacer domain, which was corroborated by N-terminal sequencing and Western blotting. Importantly, TAILS also identified proteolysis of the latent TGF-β-binding proteins 3 and 4 (LTBP3/4) at a Glu-Val and Glu-Ala site, respectively. Using purified enzyme and substrate, we confirmed ADAMTS7-catalyzed proteolysis of recombinant LTBP4. Moreover, we identified multiple additional scissile bonds in an N-terminal linker region of LTBP4 that connects fibulin-5/tropoelastin and fibrillin-1-binding regions, which have an important role in elastogenesis. ADAMTS7-mediated cleavage of LTBP4 was efficiently inhibited by the metalloprotease inhibitor TIMP-4, but not by TIMP-1 and less efficiently by TIMP-2 and TIMP-3. As TIMP-4 expression is prevalent in cardiovascular tissues, we propose that TIMP-4 represents the primary endogenous ADAMTS7 inhibitor. In summary, our findings reveal LTBP4 as an ADAMTS7 substrate, whose cleavage may potentially impact elastogenesis in the cardiovascular system. We also identify TIMP-4 as a likely physiological ADAMTS7 inhibitor.

Expressions of MMP-12, TIMP-4, and Neutrophil Elastase in PBMCs and Exhaled Breath Condensate in Patients with COPD and Their Relationships with Disease Severity and Acute Exacerbations

OBJECTIVE

The purpose of this study was to compare matrix metalloproteinase-12 (MMP-12), neutrophil elastase (NE), and tissue inhibitor of metalloproteinase-4 (TIMP-4) in peripheral blood of patients with chronic obstructive pulmonary disease (COPD) and controls. At the same time, MMP-12, NE, and TIMP-4 in exhaled breath condensate (EBC) were also evaluated.

METHODS

Peripheral blood and EBC samples from COPD patients and healthy controls were collected. In serum and EBC, MMP-12, NE, and TIMP-4 proteins were detected by enzyme-linked immunoassays. The mRNA expression levels of MMP-12, NE, and TIMP-4 in peripheral blood mononuclear cells (PBMCs) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The concentration of TIMP-4 protein in EBC was lower in patients with COPD (P < 0.001). MMP-12 (P = 0.046), NE (P = 0.027), and TIMP-4 (P = 0.005) proteins in serum of patients with COPD showed higher levels of concentration. The mRNA of MMP-12 (P = 0.0067), NE (P = 0.0058), and TIMP-4 (P = 0.0006) in PBMCs of COPD patients showed higher expression levels. Compared with stable patients, mRNA expression level of NE (P = 0.033) in PBMCs of patients with acute exacerbation of COPD was increased. There were differences in the ratio of MMP-12/TIMP-4 in PBMC (P = 0.0055), serum (P = 0.0427), and EBC (P = 0.0035) samples between COPD patients and healthy controls. The mRNA expression of MMP-12 (r = -0.3958, P = 0.0186) and NE (r = -0.3694, P = 0.0290) in COPD patients was negatively correlated with pulmonary function. However, the mRNA expression of TIMP-4 (r = 0.2871, P = 0.0945) in PBMCs was not correlated with the FEV1 of the pulmonary function. Serum MMP-12 level was positively correlated with the MMP-12 level in EBC (P = 0.0387). The level of TIMP-4 in serum was not correlated with the level in the EBC sample (P = 0.4332).

CONCLUSION

The expression levels of MMP-12, NE, and TIMP-4 in PBMCs and serum were elevated in COPD patients. In PBMCs of COPD patients, the mRNA expression level of NE may predict acute exacerbation, and MMP-12 mRNA expression level may be used to reflect the severity of airflow limitation. However, to better assess their diagnostic or prognostic value, larger studies are necessary.

Inflammatory mediators in exhaled breath condensate and peripheral blood of healthy donors and stable COPD patients

Objective: The aim of this work was to compare matrix metalloproteinase-9 and -12, tissue inhibitor of metalloproteinase-1 and -4, and neutrophil elastase in exhaled breath condensate (EBC) and peripheral blood of patients with COPD. Methods: Peripheral blood and EBC samples from COPD patients and healthy donors were collected. In serum and EBC, MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 proteins were detected by ELISA. The mRNA expression levels of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in peripheral blood mononuclear cells (PBMCs) were analyzed by qRT-PCR. Results: The protein levels of MMP-9 (p=.034) and MMP-12 (p=.041) in the EBC of COPD smokers were higher than those of COPD never-smokers. The concentrations of TIMP-1 (p=.072) and TIMP-4 (p=.084) in the EBC of COPD smokers were higher than those of COPD never-smokers; however, the difference was not statistically significant. MMP-9 (r=-0.78, p<.0001) and TIMP-1 (r=-0.71, p<.0001) levels in EBC were significantly negatively correlated with pulmonary function FEV1%pred. The protein levels of MMP-12 (r=-0.37, p=.034) and TIMP-4 (r=-0.34, p=.041) were also negatively correlated with FEV1%pred. The expression of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in PBMCs and serum of COPD smokers were significantly higher than those of control never-smokers (p<.05). Conclusions: Exhaled MMP-9, MMP-12, TIMP-1, and TIMP-4 levels increased in stable COPD patients and were negatively correlated with FEV1%pred, which suggests the usefulness of their measurement in EBC for the monitoring of airway inflammation. However, to better assess their diagnostic or prognostic value, larger studies are necessary.

Association between tissue inhibitor of metalloproteinase (TIMP) genetic polymorphisms and primary ovarian insufficiency (POI)

BACKGROUND

Until now, an association between tissue inhibitor of metalloproteinase (TIMP) polymorphisms and primary ovarian insufficiency (POI) has not been identified. The aim of our study was to investigate whether the TIMP polymorphisms TIMP1T > C (rs4898), TIMP1G > A (rs6609533), TIMP2G > C (rs8179090), TIMP2G > A (rs2277698), TIMP3G > A (rs135029), and TIMP4T > C (rs3755724), which regulate matrix metalloproteinases (MMPs), confer a risk for primary ovarian insufficiency (POI) in Korean women (further studies would be required to evaluate the associations between TIMP polymorphisms and POI in other populations).

METHODS

We genotyped 137 POI patients and 236 controls for the single nucleotide polymorphism sites using PCR-RFLP analysis. Differences in the frequencies of the TIMP1T > C (rs4898), TIMP1G > A (rs6609533), TIMP2G > C (rs8179090), TIMP2G > A (rs2277698), TIMP3G > A (rs135029), and TIMP4T > C (rs3755724) genotypes between patients and controls were compared, and odds ratios and 95% confidence intervals were determined to measure of the strength of the association between the genotypes and POI.

RESULTS

The TIMP1T > C (rs4898), TIMP1G > A (rs6609533), TIMP2G > C (rs8179090), TIMP2G > A (rs2277698), TIMP3G > A (rs135029), and TIMP4T > C (rs3755724) genotypes, but especially the TIMP2 genotypes, were found more frequently in POI patients than in control subjects. Among the four TIMP loci, the TIMP1T > C (rs4898), TIMP1G > A (rs6609533), TIMP2G > C (rs8179090), TIMP2G > A (rs2277698), TIMP3G > A (rs135029), and TIMP4T > C (rs3755724) haplotypes were identified more frequently in POI patients than in control subjects and conferred susceptibility to POI (P <0.0001).

CONCLUSIONS

The TIMP2G > C (rs8179090) and G > A (rs2277698) alleles were strongly associated with POI. Our data suggest that the minor TIMP2 alleles may increase POI risk in Korean women.

Small Vessel Disease Is Associated with Tissue Inhibitor of Matrix Metalloproteinase-4 After Ischaemic Stroke

Small vessel disease (SVD) is frequent in aging and stroke patients. Inflammation and remodeling of extracellular matrix have been suggested as concurrent mechanisms of SVD. We investigated the relationship between imaging features of SVD and circulating metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in patients with ischaemic stroke. In patients treated with intravenous thrombolysis, we took blood samples before intravenous thrombolysis and 90 days after the acute stroke and analysed levels of MMPs and TIMPs. We assessed leukoaraiosis, number of lacunes and brain atrophy on pre-treatment CT scan and graded global SVD burden combining such features. We investigated associations between single features, global SVD and MMPs and TIMPs at baseline and at follow-up, retaining univariate statistically significant associations in multivariate linear regression analysis and adjusting for clinical confounders. A total of 255 patients [mean (±SD) = 68.6 (± 12.7) years, 154 (59%) males] were included, 107 (42%) had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. A total of 107 (42%) patients had no signs of SVD; 47 (19%) had from moderate to severe SVD burden. After adjustment, only TIMP-4 proved associations with SVD features. Brain atrophy was associated with baseline TIMP-4 (β = 0.20;p = 0.019) and leukoaraiosis with 90 days TIMP-4 (β = 0.19; p = 0.013). Global SVD score was not associated with baseline TIMP-4 levels (β = 0.10; p = 0.072), whereas was associated with 90 days TIMP-4 levels (β = 0.21; p = 0.003). Total SVD burden was associated with higher TIMP-4 levels 90 days after stroke, whereas was not during the acute phase. Our results support a biological relationship between SVD grade and TIMP-4.

Monoclonal Antibody against CXCL1 (HL2401) as a Novel Agent in Suppressing IL6 Expression and Tumoral Growth

Rationale: The expression of the chemokine (C-X-C motif) ligand 1 (CXCL1), an inflammatory protein, has been reported to be up-regulated in many human cancers. The mechanisms through which aberrant cellular CXCL1 levels promote specific steps in tumor growth and progression are unknown. Methods: We described the anticancer effects and mechanism of action of HL2401, a monoclonal antibody directed at CXCL1 with in vitro and in vivo data on bladder and prostate cancers. Results: HL2401 inhibited proliferation and invasion of bladder and prostate cells along with disrupting endothelial sprouting in vitro. Furthermore, novel mechanistic investigations revealed that CXCL1 expression stimulated interleukin 6 (IL6) expression and repressed tissue inhibitor of metalloproteinase 4 (TIMP4). Systemic administration of HL2401 in mice bearing bladder and prostate xenograft tumors retarded tumor growth through the inhibition of cellular proliferation and angiogenesis along with an induction of apoptosis. Our findings reveal a previously undocumented relationship between CXCL1, IL6 and TIMP4 in solid tumor biology. Principal conclusions: Taken together, our results argue that CXCL1 plays an important role in sustaining the growth of bladder and prostate tumors via up-regulation of IL6 and down-regulation of TIMP4. Targeting these critical interactions with a CXCL1 monoclonal antibody offers a novel strategy to therapeutically manage bladder and prostate cancers.

Protein array profiling of circulating angiogenesis-related factors during bevacizumab containing treatment in metastatic colorectal cancer

BACKGROUND

Prolonged angiogenesis inhibition may improve treatment outcome in metastatic colorectal cancer (mCRC) patients. However, due to the complexity of the angiogenic pathways there is a lack of valid predictive biomarkers for anti-angiogenic agents. Here, we describe and optimize a procedure for simultaneous dynamic profiling of multiple angiogenesis related proteins in patient serum to explore associations with the response and acquired resistance to anti-angiogenic therapy.

MATERIALS AND METHODS

Patients (n=22) were selected from a clinical trial investigating maintenance treatment with bevacizumab alone after response to induction chemotherapy + bevacizumab in mCRC. Serum samples were analysed for 55 unique angiogenesis related proteins using a commercial proteome profiler array and a publicly available image analysis program for quantification. Samples were collected at baseline before induction treatment start, at start of maintenance treatment, and at end of treatment after tumour progression.

MAIN RESULTS AND CONCLUSION

For eight proteins, the antibody array signals were below detection range in all patient samples. None of the proteins showed levels at baseline or at start of maintenance with strong evidence for correlation to time to progression (lowest nominal p-value 0.03). The dynamic ranges of protein levels measured during the induction treatment period and during the maintenance period were analysed separately for time trends. Evidence for changing trends (up/down) in the levels of MMP-8, TIMP-4 and EGF was observed both during response to induction treatment and at progressive disease, respectively. For three of the proteins (IL-8, Activin A and IGFBP-2), weak evidence for correlation between increasing protein levels during induction with chemotherapy and bevacizumab and time to progression was observed. In conclusion, semi-quantitative profiling of angiogenesis related proteins in patient serum may be a versatile tool to screen for protein patterns aiming at identifying resistance mechanisms of anti-angiogenic treatment in patients with mCRC.

Circulating Tissue Inhibitor of Metalloproteinase-4 levels are not a Predictor of Preeclampsia in the period between 20 and 25 Weeks of Gestation

OBJECTIVE

 To evaluate whether the circulating level of tissue inhibitor of metalloproteinase-4 (TIMP-4) in the period between 20 and 25 weeks of gestation is a predictor of preeclampsia.

METHODS

 We have performed a case-control study, nested in a prospective study cohort in Ribeirão Preto, in the state of São Paulo, Brazil. Of the 1,400 pregnant women evaluated between 20 and 25 weeks of gestation, 460 delivered in hospitals outside of our institution. Of the 940 pregnant women who completed the protocol, 30 developed preeclampsia. Healthy pregnant women (controls, n = 90) were randomly selected from the remaining 910 participants. From blood samples collected between 20 and 25 weeks of gestation, we performed a screening of 55 angiogenesis-related proteins in 4 cases and 4 controls. The protein TIMP-4 was the most differentially expressed between cases and controls. Therefore, we measured this protein in all cases (n = 30) and controls selected (n = 90).

RESULTS

 There were no differences in the plasma TIMP-4 levels of cases compared with controls (1,144 ± 263 versus 1,160 ± 362 pg/mL, respectively; p > 0.05).

CONCLUSION

 Plasma TIMP-4 levels were not altered at 20 to 25 weeks of gestation, before the manifestation of clinical symptoms; therefore, they are not good predictors of the development of preeclampsia.

Divergent changes in the content and activity of MMP-26 and TIMP-4 in human umbilical cord tissues associated with preeclampsia

OBJECTIVES

Preeclampsia is the most common disorder associated with pregnancy. Our earlier findings revealed a substantial increase in the amount of matrix metalloproteinase-26 (matrilysin 2; MMP-26) in preeclamptic umbilical cord blood. The role of MMP-26 in preeclamptic umbilical cord tissue has not been fully elucidated. Some reports have indicated that the expression of matrilysin 2 and tissue inhibitor of matrix metalloproteinase 4 (TIMP-4) is coordinately regulated during progression of various diseases.

STUDY DESIGN

Therefore, we decided to assess the expression and activity of MMP-26 and TIMP-4 in normal and preeclamptic umbilical cord tissues - umbilical cord arteries (UCA), vein (UCV) and Wharton's jelly (WJ). Tissues obtained from 10 normal (control material) and 10 preeclamptic umbilical cords were assessed using immunoenzymatic assay, Western immunoblotting, reverse transcriptase - polymerase chain reaction and fluorometric determination of the enzyme activity.

RESULTS

All umbilical cord tissues, both control and preeclamptic, expressed MMP-26 and TIMP-4 in macromolecular complexes. Preeclampsia induced a significant increase in the content and actual activity of MMP-26 in UCV and WJ, as compared to control. The content of TIMP-4 in preeclamptic UCV and WJ was reduced. The content of MMP-26 mRNA was lower in UCA and UCV, whereas higher in WJ in preeclampsia.

CONCLUSIONS

Divergent changes in MMP-26 mRNA and protein expression suggest a difference in the factors controlling the matrilysin synthesis in healthy and preeclamptic subjects. The decrease in TIMP-4 content in preeclamptic UCV might be the main reason for significantly higher actual activity of MMP-26 in that tissue. Only in preeclamptic Wharton's jelly the changes were compatible in terms of the content and activity of MMP-26 and TIMP-4. It cannot be excluded that similar alterations can be observed for the whole vascular system of newborns delivered by mothers with preeclampsia.

Deletion of BMAL1 in Smooth Muscle Cells Protects Mice From Abdominal Aortic Aneurysms

OBJECTIVE

Abdominal aortic aneurysm (AAA) has high mortality rate when ruptured, but currently, there is no proven pharmacological therapy for AAA because of our poor understanding of its pathogenesis. The current study explored a novel role of smooth muscle cell (SMC) BMAL1 (brain and muscle Arnt-like protein-1)-a transcription factor known to regulate circadian rhythm-in AAA development.

APPROACH AND RESULTS

SMC-selective deletion of BMAL1 potently protected mice from AAA induced by (1) MR (mineralocorticoid receptor) agonist deoxycorticosterone acetate or aldosterone plus high salt intake and (2) angiotensin II infusion in hypercholesterolemia mice. Aortic BMAL1 was upregulated by deoxycorticosterone acetate-salt, and deletion of BMAL1 in SMCs selectively upregulated TIMP4 (tissue inhibitor of metalloproteinase 4) and suppressed deoxycorticosterone acetate-salt-induced MMP (matrix metalloproteinase) activation and elastin breakages. Moreover, BMAL1 bound to the Timp4 promoter and suppressed Timp4 transcription.

CONCLUSIONS

These results reveal an important, but previously unexplored, role of SMC BMAL1 in AAA. Moreover, these results identify TIMP4 as a novel target of BMAL1, which may mediate the AAA protective effect of SMC BMAL1 deletion.

Differential expression and localization of human tissue inhibitors of metalloproteinases in proliferative diabetic retinopathy

PURPOSE

Tissue inhibitors of metalloproteinases (TIMPs) block the catalysis by matrix metalloproteinases (MMPs) and have additional biologic activities, including regulation of cell growth and differentiation, apoptosis, angiogenesis and oncogenesis. We investigated the expression levels of all the four human TIMPs and correlated these levels with those of MMP-9 and vascular endothelial growth factor (VEGF) in proliferative diabetic retinopathy (PDR).

METHODS

Vitreous samples from 38 PDR and 21 nondiabetic control patients and epiretinal membranes from 14 patients with PDR and 10 patients with proliferative vitreoretinopathy (PVR) were studied by enzyme-linked immunosorbent assay, Western blot analysis and immunohistochemistry.

RESULTS

Tissue inhibitor of metalloproteinases-1, TIMP-4, MMP-9 and VEGF levels were significantly higher in vitreous samples from PDR patients than in nondiabetic controls (p < 0.0001 for all comparisons), whereas TIMP-2 and TIMP-3 levels did not differ significantly. TIMP-1, TIMP-4, MMP-9 and VEGF levels in PDR with active neovascularization were significantly higher than those in inactive PDR (p < 0.0001, 0.001, 0.013, 0.004, respectively). Significant positive correlations existed between levels of TIMP-1 and levels of TIMP-4 (r = 0.37; p = 0.004), MMP-9 (r = 0.65; p < 0.0001) and VEGF (r = 0.59; p < 0.0001), between levels of TIMP-4 and levels of MMP-9 (r = 0.61; p < 0.0001) and VEGF (r = 0.62; p < 0.0001) and between levels of MMP-9 and VEGF (r = 0.62; p < 0.0001). TIMP-1 and TIMP-3 were expressed in vascular endothelial cells in PDR epiretinal membranes and in myofibroblasts and leucocytes in PDR and PVR epiretinal membranes.

CONCLUSION

The differential expression of TIMPs in PDR suggests that among the 4 TIMPs, TIMP-1 and TIMP-4 may be possible biomarkers of disease activity.

The DNA methylation status of genes encoding Matrix metalloproteinases and tissue inhibitors of Matrix metalloproteinases in endometriosis

Endometriosis is a benign disease, with malignant properties. A necessary step in the progression of endometriosis is tissue remodeling, which is coordinated by the activities of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). This study evaluated the regulation of abnormal MMP and TIMP gene expression during endometriosis. Among the two genes families, promoter regions of MMP2, MMP3, MMP7, TIMP3, and TIMP4 were significantly altered in proliferative-phase endometriotic lesions compared to menstrual cycle-matched eutopic tissue from endometriosis-free women. In addition, a negative correlation was found between the DNA methylation status of the promoter region and transcript abundance of MMP2. Our findings suggest that changes in DNA methylation at the promoter region of MMP2 could underlie the changes in its expression in the ectopic endometria from patients with endometriosis.

Higher levels of circulating TIMP-4 in preeclampsia is strongly associated with clinical parameters and microRNA

BACKGROUND

Preeclampsia results in maternal and fetal complications and some studies have reported the role of MMPs and TIMPs in its pathophysiology. Therefore, the aim of this study was to compare plasma TIMP-4 levels in preeclampsia and healthy pregnant; and to correlate these levels with clinical parameters and expression of Let7a-5p (3´UTR post-transcriptionally regulation) Methods: TIMP-4 was measured by ELISA and miR-Let7a-5p expression by qPCR.

RESULTS

Elevated plasma TIMP-4 levels in preeclampsia compared to healthy pregnant was found 1450 ± 411 vs. 775 ± 210 pg/mL, respectively (p < 0.0001); these levels are correlated positively with serum liver enzymes (ALT, r = 0.84, p = 0.004; and AST, r = 0.51, p = 0.02); and negatively with newborn weight (r = -0.45, p = 0.04) in preeclampsia. Regarding Let7a-5p a negative but not significant correlation was found (r = -0.39, p = 0.06, including both healthy and preeclampsia).

CONCLUSIONS

Preeclampsia present elevated levels of circulating TIMP-4 compared to healthy pregnant and these levels are correlated with clinical parameters of disease.

Biomarkers of drug-induced kidney injury

PURPOSE OF REVIEW

Drug-induced kidney injury (DIKI) is an important and potentially modifiable cause of acute kidney injury (AKI). The reliance on traditional markers of kidney injury to diagnose DIKI impedes early detection. Biomarkers of DIKI that facilitate early diagnosis and the identification of high-risk patients are essential to ameliorate the clinical burden of this complication.

RECENT FINDINGS

Recent progress in this area supports the potential utility of several biomarkers for the diagnosis of DIKI, for the prediction of outcomes and also for monitoring responses to potential nephrotoxic or beneficial therapies. Data regarding the impact of clinically relevant factors, such as chronic kidney disease, on biomarker levels represents a further recent advancement. Emerging novel biomarkers include microRNAs, which are showing promise as markers of drug-induced tubular damage. They may also have a role in elucidating the molecular mechanisms of AKI.

SUMMARY

There is compelling evidence to support the use of biomarkers for the early detection of DIKI. Ongoing research is required to delineate their role in prognostication and for the prediction of outcomes. The inclusion of biomarkers in more clinical studies of DIKI would be a welcome advance, which may accelerate their integration into clinical diagnostics.

Plasma MMP2/TIMP4 Ratio at Follow-up Assessment Predicts Disease Progression of Idiopathic Pulmonary Arterial Hypertension

PURPOSE

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are of particular interest in the remodeling processes of pulmonary hypertension. The aim of this study was to investigate MMP/TIMP ratios of selected biomarkers (MMP2, MMP9, TIMP1, TIMP4) at follow-up examination (V2) and their prognostic value in patients with idiopathic pulmonary arterial hypertension (iPAH).

METHODS

Blood samples were taken from iPAH patients during right heart catheterization at diagnosis (V1, from 2003 to 2012) and first follow-up examination (V2). MMP2, MMP9, TIMP1, and TIMP4 plasma levels at V2 were determined by ELISA. Coincident with sample collection hemodynamic, laboratory, and clinical parameters were acquired. Additionally, death and clinical worsening (CW) events were listed until July 2015.

RESULTS

MMP2/TIMP1 and MMP9/TIMP1 did not correlate with hemodynamic and clinical parameters. MMP2/TIMP4 showed a good correlation with mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance, estimated glomerular filtration rate (eGFR), and tricuspid annular plain systolic excursion (TAPSE). MMP9/TIMP4 shows good correlation with mPAP and eGFR. MMP2/TIMP4 showed significant results in the receiver operating characteristics analysis predicting death (AUC = 0.922; p = 0.005) and CW event (AUC = 0.818; p = 0.026). Patients above the cut-off values had a significantly higher probability to die or experience CW, respectively, estimated by log-rank test (p = 0.010 for death; p = 0.032 for CW).

CONCLUSIONS

MMP2/TIMP4 ratio was detected as a marker of disease severity and right ventricular function as well as a predictor for survival and time to clinical worsening and therefore might help for guidance of disease progression in iPAH patients at V2.

Absence of Tissue Inhibitor of Metalloproteinase-4 (TIMP4) ameliorates high fat diet-induced obesity in mice due to defective lipid absorption

Tissue inhibitor of metalloproteases (TIMPs) are inhibitors of matrix metalloproteinases (MMPs) that regulate tissue extracellular matrix (ECM) turnover. TIMP4 is highly expressed in adipose tissue, its levels are further elevated following high-fat diet, but its role in obesity is unknown. Eight-week old wild-type (WT) and Timp4-knockout (Timp4 -/-) mice received chow or high fat diet (HFD) for twelve weeks. Timp4 -/- mice exhibited a higher food intake but lower body fat gain. Adipose tissue of Timp4 -/- -HFD mice showed reduced hypertrophy and fibrosis compared to WT-HFD mice. Timp4 -/- -HFD mice were also protected from HFD-induced liver and skeletal muscle triglyceride accumulation and dyslipidemia. Timp4 -/--HFD mice exhibited reduced basic metabolic rate and energy expenditure, but increased respiratory exchange ratio. Increased free fatty acid excretion was detected in Timp4 -/--HFD compared to WT-HFD mice. CD36 protein, the major fatty acid transporter in the small intestine, increased with HFD in WT but not in Timp4 -/- mice, despite a similar rise in Cd36 mRNA in both genotypes. Consistently, HFD increased enterocyte lipid content only in WT but not in Timp4 -/- mice. Our study reveals that absence of TIMP4 can impair lipid absorption and the high fat diet-induced obesity in mice possibly by regulating the proteolytic processing of CD36 protein in the intestinal enterocytes.

Usefulness of Plasma Tissue Inhibitor of Matrix Metalloproteinase-4 to Predict Death and Myocardial Infarction in Patients With Diabetes Mellitus Referred for Coronary Angiography

TIMP-4 is the newest member of a family of secreted proteins known as the tissue inhibitors of metalloproteases that selectively inhibit matrix metalloproteases. TIMP-4 is abundantly expressed in human cardiovascular structures and has been implicated in cardiovascular disease. Furthermore, it has also been shown to be a novel target of peroxisome proliferator-activated receptor gamma in rat smooth muscle cells, suggesting a potential role in diabetes mellitus as well. However, there have been no studies that have specifically examined the utility of baseline plasma TIMP-4 levels for the prediction of long-term adverse cardiovascular outcomes. In this study, baseline plasma TIMP-4 levels were measured in 162 male patients with diabetes mellitus who were referred for coronary angiography and followed prospectively for the development of all-cause mortality and enzymatically confirmed myocardial infarction (MI) out to 5 years. After adjustment for a variety of baseline clinical, angiographic and laboratory parameters, plasma TIMP-4 levels were an independent predictor of all-cause mortality (hazard ratio 1.60, 95% CI 1.13 to 2.26; p = 0.0082) and MI (hazard ratio 1.61, 95% CI 1.19 to 2.18; p = 0.0021) at 5 years. Furthermore, in additional multivariate models that adjusted for a variety of biomarkers with established prognostic efficacy, TIMP-4 remained an independent predictor of adverse outcomes. In conclusion, elevated levels of TIMP-4 are associated with an increased risk of long-term all-cause mortality and MI in patients with diabetes mellitus referred for coronary angiography. Moreover, this association is independent of a variety of clinical, angiographic, and laboratory variables, including biomarkers with established prognostic efficacy in the prediction of adverse cardiovascular outcomes.

Modulation of Matrix Metalloproteinase 14, Tissue Inhibitor of Metalloproteinase 3, Tissue Inhibitor of Metalloproteinase 4, and Inducible Nitric Oxide Synthase in the Development of Periapical Lesions

INTRODUCTION

Periapical cysts and granulomas are chronic lesions caused by an inflammatory immune response against microbial challenge in the root canal. Different cell types, cytokines, and molecules have been associated with periapical lesion formation and expansion. Therefore, because of the chronic inflammatory state of these lesions, the aim of this study was to evaluate the in situ expression of matrix metalloproteinase (MMP)-14 and -19, tissue inhibitor of metalloproteinase (TIMP)-3 and -4, CD68, and inducible nitric oxide synthase (iNOS) in periapical cysts and granulomas.

METHODS

Sixteen cases of periapical cysts and 15 cases of periapical granulomas were analyzed. Ten normal dental pulps were used as the negative control. Immunohistochemistry was performed with anti-MMP-19, anti-MMP-14, anti-TIMP-3, anti-TIMP-4, anti-iNOS, and anti-CD68 antibodies.

RESULTS

The expression of TIMP-3, TIMP-4, iNOS, and CD68 was significantly higher in both the cyst and granuloma groups than in the control group. TIMP-4 was also significantly higher in cases of chronic apical abscess. There was also a significant difference in the expression of MMP-14 between the cyst and control groups. However, there were no differences in the expression of MMP-19 between the 3 groups.

CONCLUSIONS

Our data suggest that the expression of MMP-14, TIMP-3, and TIMP-4 is associated with the development of periapical lesions.

Genetic Predictors of ≥5% Weight Loss by Multidisciplinary Advice to Severely Obese Subjects

BACKGROUND

Weight loss success is determined by genetic factors, which may differ according to treatment strategy.

METHODS

From a multidisciplinary obesity treatment program involving dietary advice, psychological counseling, and increased physical activity, 587 subjects (68% female; 46.1 ± 12.4 years; BMI 39.9 ± 6.3) were recruited. At baseline, a blood sample was drawn for DNA isolation. Genotypes were determined for 30 polymorphisms in 25 candidate genes. The association between genotypes and weight loss was assessed after 3 months (short-term) and after 12 months of treatment (long-term). Weight loss was categorized as ≥5% or <5% of initial weight.

RESULTS

The G/G genotype of PLIN1 (rs2289487) and PLIN1 (rs2304795), the T/T genotype of PLIN1 (rs1052700), and the C/C genotype of MMP2 predicted ≥5% weight loss in the first 3 months. The C/G-G/G genotype of PPARγ (rs1801282) and the T/C genotype of TIMP4 (rs3755724) predicted ≥5% weight loss after 12 months. Subjects with the combination of PPARγ (rs1801282) C/G-G/G and TIMP4 (rs3755724) T/C lost even more weight.

CONCLUSION

Polymorphisms in genes related to regulation of fat storage and structural adaptation of the adipocytes are predictors for weight loss success with different genes being relevant for short-term and long-term weight loss success.

CHA2DS2-VASc score and blood biomarkers to identify patients with atrial high-rate episodes and paroxysmal atrial fibrillation

AIMS

Paroxysmal atrial fibrillation (PAF) is often asymptomatic but nonetheless harmful. We evaluated the performance of disease-related blood biomarkers and CHA2DS2-VASc score to discriminate for PAF in patients with continuous rhythm monitoring.

METHODS AND RESULTS

Clinical data and blood samples were obtained from patients with dual-chamber pacemakers selected according to the absence (no_AHRE) or presence of Atrial High-Rate Episodes (AHRE) >6 min in recent device history (case-control approach). We included 93 patients (n = 49 AHRE, n = 44 no_AHRE). In a subgroup with high AHRE burden and confirmed PAF 15 biomarkers were evaluated (n = 19 AHRE-AF vs. n = 20 no_AHRE). Significantly regulated biomarkers were then tested in all patients to distinguish no_AHRE from AHRE (receiver operating characteristics analysis). Hsp27, TGFβ1, cystatin C, matrix metalloproteinases MMP-2,-3,-9, albumin, and serum uric acid were not altered in the subgroup. Tissue inhibitors of metalloproteinases (TIMP) -1,-2,-4; NT-proANP, NT-proBNP, IL-6 and serum amyloid protein A were significantly different in AHRE vs. no_AHRE (subgroup and whole cohort), with best discriminatory performance for TIMP-4. Biomarkers performed better than CHADS2-VASc for AHRE discrimination. Intracardial electrograms and medical history from seven AHRE patients suggested atrial tachycardia and not AF (AHRE-AT). Four of the most relevant regulated biomarkers (TIMP-4, TIMP-2, SAA, NT-proBNP) behaved similarly in AHRE-AT and AHRE-AF. NT-proBNP >150 pg/mL indicated an odds ratio of 12.9 for AHRE. Combining two biomarkers significantly improved discrimination of AHRE.

CONCLUSION

TIMP-4, NT-proANP, NT-proBNP were strongest associated with PAF and AHRE. The discriminatory performance of CHADS2-VASc for PAF was increased by addition of selected biomarkers.

Effect of simvastatin on MMPs and TIMPs in cigarette smoke-induced rat COPD model

BACKGROUND

Proteases may play an important role in the development of chronic obstructive pulmonary disease and emphysema in response to cigarette smoke exposure (CSE). The current study was designed to investigate the expression of matrix metalloproteinase (MMP)-8, MMP-9, MMP-12, tissue inhibitor of MMP (TIMP)-1, and TIMP-4 in rat lung tissues in response to CSE, and assessed the effect of simvastatin in regulating expression of MMPs and TIMPs.

METHODS

Thirty normal Sprague Dawley (SD) rats were divided into control (n=10), CSE (n=10), and CSE plus simvastatin (n=10) groups. Animals were whole-body exposed to the cigarette smoke in the box for 1 hour each time, twice a day, 5 days a week for 16 weeks. Animals of CSE + simvastatin group were intra-gastrically administered simvastatin at a dose of 5 mg/kg/day followed by CSE. Bronchoalveolar lavage fluid was harvested for inflammatory cell count and lung tissues were stained for morphologic examination. Expression of mRNA and protein level of MMP-8, MMP-9, MMP-12, TIMP-1, and TIMP-4 was assessed by real-time reverse transcription polymerase chain reaction and immunohistochemistry, respectively.

RESULTS

CSE resulted in a significant increase of mean linear intercept (MLI: 34.6±2.0 μm) and bronchial wall thickness and diameter (BWT/D, 0.250±0.062) compared to control (MLI: 24.0±1.7 μm, BWT/D: 0.160±0.034, P<0.01). In contrast, mean alveolar number was significantly decreased in the CSE group than that in the control group (13.5±2.0 of CSE vs 21.5±2.0 N/μm2 of control, P>0.01). Simvastatin slightly but not significantly prevented alteration of MLI, BWT/D, and mean alveolar number (MLI: 33.4±1.4 μm; BWT/D: 0.220±0.052; mean alveolar number: 15.5±2.5 N/μm2, P>0.05). Total white blood cell was significantly increased in the bronchoalveolar lavage fluid of smoking group (3.3±2.5×109 cells/L vs 1.1±1.3×109 cells/L of control, P<0.01), and it was significantly reduced by simvastatin (2.3±2.1×109 cells/L, P<0.01). CSE resulted in significantly increased accumulation of neutrophils and macrophages (neutrophils: 14.5%±1.3% of CSE group vs 9.1%±1.5% of control; macrophage: 91%±3% of CSE group vs 87%±2% of control, P<0.05), and simvastatin significantly reduced neutrophils (12.9%±2.0%, P<0.05) in the bronchoalveolar lavage fluid, but had no effect on macrophage (89%±1.6%, P>0.05). In response to CSE, MMP-8, MMP-9, and MMP-12 mRNA were upregulated more than sevenfold, while TIMP-1 and TIMP-4 increased two- to fivefold. Simvastatin significantly blocked upregulation of MMP-8 and -9 (P<0.01), but had no effect on MMP-12, TIMP-1 and TIMP-4 mRNA (P>0.05). In addition, simvastatin significantly blocked cigarette smoke-induced MMP-8 and -9 protein synthesis, while it had no significant effect on TIMP-1 and -4 protein synthesis even in the presence of cigarette smoke.

CONCLUSION

CSE resulted in imbalance of MMPs and TIMPs, and by which mechanism, cigarette smoke may lead to insufficient lung tissue repair. Simvastatin partially blocked airway inflammation and MMP production and, thus, statins may modulate composition of the lung extracellular matrix.

TIMP4 expression is regulated by miR-200b-3p in prostate cancer cells

In prostate cancer TIMP4 expression level fluctuates with tumor progression. The mechanism and factors influencing its expression remain unclear. The aim of the study was to test the hypothesis on regulation of TIMP4 by microRNA-200b-3p. The levels of TIMP4 and miR-200b-3p expression were determined by real time PCR in 27 prostate carcinomas and eight benign prostatic hyperplasia samples. We found that miR-200b-3p positively correlated with TIMP4 expression in cancer samples (r = 0.46; p < 0.02). Moreover, mean miR-200b-3p level and TIMP4 expression were both higher in cancer tissues compared to benign prostatic hyperplasia samples (p > 0.05). Next, to test probable mechanisms of the regulation androgen-sensitive human prostate adenocarcinoma cells (LNCaP) were transfected with synthetic-miR-200b-3p or its synthetic antagonist. Modulation of miR-200b-3p in LNCaP cells had an impact on TIMP4 expression confirming the observation made in analyzed clinical samples. Two targets of miR-200b-3p: ZEB1 and ETS1 were investigated subsequently as potential regulators of TIMP4, however, no effect of their modulation on TIMP4 expression in LNCaP cells was found. Concluding, miR-200b-3p mediates regulation of TIMP4 expression in prostate cancer but exact mechanism needs to be investigated.

MMP-12 and TIMP Behavior in Symptomatic and Asymptomatic Critical Carotid Artery Stenosis

OBJECTIVE

The aim of this study was to evaluate the levels of matrix metalloproteinase-12 (MMP-12) and tissue inhibitors of metalloproteinases (TIMP)-1, TIMP-2, TIMP-3, and TIMP-4 in patients with symptomatic and asymptomatic critical carotid artery stenosis (CAS).

METHODS

We enrolled 10 patients affected by symptomatic CAS within 12 hours from onset of stroke (S group) and 30 patients with asymptomatic CAS (CAS group); 31 patients matched for age, sex, and traditional cardiovascular risk factors were used as controls (RF group). Serum levels of MMP-12, TIMP-1, TIMP-2, TIMP-3, and TIMP-4 were assessed by Luminex.

RESULTS

MMP-12 levels were significantly higher both in the S and CAS groups than in the RF group (P < .001). We found a significant decrease of all TIMPs in the CAS group compared with the RF group, whereas a significant increase was observed in the S group compared with the CAS group. A significant increase of TIMP-3 and TIMP-4 levels was observed in the S group compared with all other groups.

CONCLUSION

MMP-12 is related to critical CAS both symptomatic and asymptomatic, being mainly released in the late stage of plaque development. Moreover, we suggest that a specific pattern of matrix degrading enzyme inhibitors arises during the early phases of stroke.

High-fat diet-induced obesity regulates MMP3 to modulate depot- and sex-dependent adipose expansion in C57BL/6J mice

Increased adipocyte size is hypothesized to signal the recruitment of adipose progenitor cells (APCs) to expand tissue storage capacity. To investigate depot and sex differences in adipose growth, male and female C57BL/6J mice (10 wk-old) were challenged with high-fat (HF) or low-fat (LF) diets (D) for 14 wk. The HFD increased gonadal (GON) depot weight by adipocyte hypertrophy and hyperplasia in females but hypertrophy alone in males. In both sexes, inguinal (ING) adipocytes were smaller than GON, and depot expansion was due to hypertrophy. Matrix metalloproteinase 3 (Mmp3), an antiadipogenic factor, and its inhibitor Timps modulate the extracellular matrix remodeling needed for depot expansion. Mmp3 mRNA was depot different (ING > GON), higher in females than males and mainly expressed in APCs. In males, HFD-induced obesity increased tissue and APC Mmp3 mRNA levels and MMP3 protein and enzymatic activity. In females however, HFD significantly decreased MMP3 protein without affecting its mRNA levels. MMP3 activity also decreased (significant in ING). Timp4 mRNA was expressed mainly in adipocytes, and HFD-induced obesity tended to increase the ratio of TIMP4 to MMP3 protein in females, whereas it decreased it in males. Overexpression of Mmp3 in 3T3-L1 preadipocytes or rhMMP3 protein added to primary human preadipocytes inhibited differentiation, whereas rhTIMP4 improved adipogenesis and attenuated the inhibitory effect of rhMMP3. These data suggest that HFD-induced obesity downregulates APC MMP3 expression to trigger adipogenesis, and adipocyte TIMP4 may modulate this process to regulate hyperplastic vs. hypertrophic adipose tissue expansion, fat distribution, and metabolic health in a sex- and depot-dependent manner.

Tissue inhibitor of metalloproteinases-4 (TIMP-4) regulates stemness in cervical cancer cells

Tissue inhibitor of metalloproteinase-4 (TIMP-4) belongs to a family of extracellular matrix (ECM) metalloproteinases inhibitors that are overexpressed in several cancers. However, the role of TIMP-4 during carcinogenesis is poorly understood. To evaluate TIMP-4 functions in carcinogenesis, stably transfected cells overexpressing this tissue inhibitor were used. Xenograft tumor growth, stem cell enrichment, colony formation, and gene regulation were investigated. Microarrays and in silico analysis were carried out to elucidate TIMP-4 molecular mechanisms. In the present report, we show that in nude mice, cervical cancer cells that overexpress TIMP-4 formed tumors faster than control cell-derived tumors. Furthermore, in vivo limiting dilution assays showed that fewer TIMP-4 overexpressing cells are needed for tumor formation. In vitro analyses demonstrated that TIMP-4 overexpression or exposure to human recombinant TIMP-4 (hrTIMP4) caused an enrichment of the tumor progenitor cell (TPC) population. Accordingly, genome-wide expression and signaling pathway analyses showed that hrTIMP-4 modulated cell survival, cell proliferation, inflammation, and epithelial-mesenchymal transition (EMT) signaling networks. Notably, NFκB signaling pathway appeared to be globally activated upon hrTIMP-4 treatment. Overall, this report provides the first example that TIMP-4 regulates carcinogenesis through enriching the TPC population in cervical cancer cells. Understanding TIMP-4 effects on tumorigenesis may provide clues for future therapies design. © 2015 Wiley Periodicals, Inc.

Xinmailong mitigated epirubicin-induced cardiotoxicity via inhibiting autophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Using insects, such as the cockroach, for the treatment of disease has a long history in traditional Chinese medicine. Xinmailong (XML) Injection, a bioactive composite extracted from Periplaneta americana (a species of cockroach), shows reasonable protective effects against cardiovascular injury and was approved for the use in the treatment of cardiac dysfunction in 2006, yet its cardio protective mechanisms remain unclear.

AIM

The present study aims to examine the protective effects of XML against epirubicin-induced cardiotoxicity in vivo and determine its underlying mechanisms.

MATERIALS AND METHODS

The chemical characteristics of XML were identified using high performance liquid chromatography (HPLC). Rats were intraperitoneally injected with epirubicin and then treated with XML for 14 days. Survival rate, echocardiography, electrocardiographic recordings and Masson staining were used to evaluate the cardioprotective activity of XML. Western blot and quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) analyses were used to investigate the molecular mechanisms underlying the actions of XML.

RESULTS

XML treatment significantly enhanced the survival rate of rats from epirubicin-induced heart failure. XML prevented left ventricle dilatation, improved cardiac function. Furthermore, treatment with XML also significantly inhibited the accumulation of collagen, reduced the levels of mRNA for matrix metalloproteinases-9 (Mmp9) and transforming growth factor-β 1(Tgfb1). This action of XML therefore might be responsible, at least in part, for the attenuation of cardiac fibrotic remodeling. XML inhibited autophagy as evidenced by the decreased accumulation of Beclin1 and autophagy related 7 (Atg7), which are necessary to form autophagosome structures. Protein kinase B (PKB/Akt), phosphatidylinositol 3 kinase (PI3K) and B cell lymphoma2 (Bcl2) levels were up-regulated, while significantly decreased protein levels for phosphorylated P38 and extracellular regulated protein kinases 1/2 (Erk1/2) were observed in the XML treated rats. The autophagy related results suggested that the increase in PI3K/Akt levels and inhibition of the phosphorylation of P38 MAPK and Erk1/2 contributed to the anti-autophagic activity of XML.

CONCLUSIONS

Our data suggest that XML may be effective for mitigating epirubicin-induced cardiomyopathy and inhibits autophagy via activating the PI3K/Akt signaling pathway and inhibiting the Erk1/2 and P38 MAPK signaling pathways.

Epigenetic silencing of TIMP4 in heart failure

Tissue inhibitor of matrix metalloprotease 4 (TIMP4) is endogenously one of the key modulators of matrix metalloprotease 9 (MMP9) and we have reported earlier that cardiac specific TIMP4 instigates contractility and helps in differentiation of cardiac progenitor cells. Although studies show that the expression of TIMP4 goes down in heart failure but the mechanism is unknown. This study aims to determine the mechanism of silencing of TIMP4 in heart failure progression created by aorta-vena cava (AV) fistula. We hypothesize that there is epigenetic silencing of TIMP4 in heart failure. To validate this hypothesis, we created heart failure model by creating AV fistula in C57BL/6 mice and looked into the promoter methylation (methylation specific PCR, high resolution melting, methylation sensitive restriction enzyme and Na bisulphite treatment followed by sequencing), histone modification (ChIP assay) and microRNAs that regulate TIMP4 (mir122a) and MMP9 (mir29b and mir455-5p). The physiological parameters in terms of cardiac function after AV fistula were assessed by echocardiography. We observed that there are 7 CpG islands in the TIMP4 promoter which get methylated during the progression of heart failure which leads to its epigenetic silencing. In addition, the up-regulated levels of mir122a in part, contribute to regulation of TIMP4. Consequently, MMP9 gets up-regulated and leads to cardiac remodeling. This is a novel report to explain the epigenetic silencing of TIMP4 in heart failure.

Lysyl Oxidase (LOX) Transcriptionally Regulates SNAI2 Expression and TIMP4 Secretion in Human Cancers

PURPOSE

Epithelial-to-mesenchymal transition (EMT) is important in cancer progression and metastasis. We and others have previously reported that lysyl oxidase (LOX) is overexpressed in aggressive cancers, is associated with increased mortality, and regulates EMT. However, the mechanism by which LOX mediates EMT is unknown. In this study, we investigated the effect of LOX on mediators of EMT.

EXPERIMENTAL DESIGN

We used chromatin immunoprecipitation and promoter luciferase assays to determine the target gene of LOX. To determine the effects of SNAI2 in vivo, we used our metastatic anaplastic thyroid cancer (ATC) mouse model. To investigate the effects of LOX and SNAI2 on MMPs and TIMPs, protein arrays were used. Primary tumors from patients with metastatic, breast and colon cancer, and tissue array for thyroid cancer were assessed for SNAI2 and TIMP4 expression by immunohistochemistry.

RESULTS

We found that LOX knockdown decreases SNAI2 expression in cancer cell lines. Furthermore, knockdown of LOX reduced SNAI2 expression in a metastatic mouse model of thyroid cancer. We also demonstrated that LOX binds and transactivates the SNAI2 promoter. We found a direct correlation in thyroid and breast cancer samples between LOX and SNAI2 expression. To understand how LOX/SNAI2 axis mediates these effects, we performed a comprehensive analysis of MMPs/TIMPs. LOX and SNAI2 depletion reduced TIMP4 secretion. Analysis of SNAI2 and TIMP4 expression showed overexpression of both proteins in aggressive thyroid, colon, and breast tumors.

CONCLUSIONS

Our findings provide new evidence that LOX regulates SNAI2 expression and that SNAI2-mediated TIMP4 secretion plays a role in cancer progression. Clin Cancer Res; 22(17); 4491-504. ©2016 AACR.

Differential expression levels of collagen 1A2, tissue inhibitor of metalloproteinase 4, and cathepsin B in intracranial aneurysms

AIMS

Intracranial aneurysms (IAs) express a variety of differentially expressed genes when compared to the normal artery. The aim of this study was to evaluate the expression level of a few genes in the aneurysm wall and to correlate them with various clinicoradiological factors.

MATERIALS AND METHODS

The mRNA level of collagen 1A2 (COL1A2), tissue inhibitor of metalloproteinase 4 (TIMP4), and cathepsin B (CTSB) genes were studied in 23 aneurysmal walls and 19 superficial temporal arteries harvested from 23 patients undergoing clipping of IAs, by real-time polymerase chain reaction method.

RESULTS

The mean fold change of COL1A2 gene between the aneurysm sample and the superficial temporal artery (STA) sample was 2.46 ± 0.12, that of TIMP4 gene was 0.31 ± 0, and that of CTSB gene was 31.47 ± 39.01. There was a positive correlation of TIMP4 expression level with maximum diameter of aneurysm (P = 0.008) and fundus of aneurysm (P = 0.012). The mean fold change of CTSB of patients who had preoperative hydrocephalus in the computed tomogram (CT) scan of the head at admission was 56.16 and that of the patients who did not have hydrocephalus was 13.51 (P = 0.008). The mean fold change of CTSB of patients who developed fresh postoperative deficits or worsening of the preexisting deficits was 23.64 and that of the patients who did not develop was 42.22 (P = 0.039).

CONCLUSIONS

COL1A2 gene and CTSB genes were overexpressed, and TIMP4 gene was underexpressed in the aneurysmal sac compared to STA and their expression levels were associated with a few clinicoradiological factors.

Ageing does not result in a decline in cell synthetic activity in an injury prone tendon

Advancing age is a well-known risk factor for tendon disease. Energy-storing tendons [e.g., human Achilles, equine superficial digital flexor tendon (SDFT)] are particularly vulnerable and it is thought that injury occurs following an accumulation of micro-damage in the extracellular matrix (ECM). Several authors suggest that age-related micro-damage accumulates due to a failure of the aging cell population to maintain the ECM or an imbalance between anabolic and catabolic pathways. We hypothesized that ageing results in a decreased ability of tendon cells to synthesize matrix components and matrix-degrading enzymes, resulting in a reduced turnover of the ECM and a decreased ability to repair micro-damage. The SDFT was collected from horses aged 3-30 years with no signs of tendon injury. Cell synthetic and degradative ability was assessed at the mRNA and protein levels. Telomere length was measured as an additional marker of cell ageing. There was no decrease in cellularity or relative telomere length with increasing age, and no decline in mRNA or protein levels for matrix proteins or degradative enzymes. The results suggest that the mechanism for age-related tendon deterioration is not due to reduced cellularity or a loss of synthetic functionality and that alternative mechanisms should be considered.

Reducing Timp3 or vitronectin ameliorates disease manifestations in CADASIL mice

OBJECTIVE

CADASIL is a genetic paradigm of cerebral small vessel disease caused by NOTCH3 mutations that stereotypically lead to the extracellular deposition of NOTCH3 ectodomain (Notch3(ECD) ) on the vessels. TIMP3 and vitronectin are 2 extracellular matrix proteins that abnormally accumulate in Notch3(ECD) -containing deposits on brain vessels of mice and patients with CADASIL. Herein, we investigated whether increased levels of TIMP3 and vitronectin are responsible for aspects of CADASIL disease phenotypes.

METHODS

Timp3 and vitronectin expression were genetically reduced in TgNotch3(R169C) mice, a well-established preclinical model of CADASIL. A mouse overexpressing human TIMP3 (TgBAC-TIMP3) was developed. Disease-related phenotypes, including cerebral blood flow (CBF) deficits, white matter lesions, and Notch3(ECD) deposition, were evaluated between 6 and 20 months of age.

RESULTS

CBF responses to neural activity (functional hyperemia), topical application of vasodilators, and decreases in blood pressure (CBF autoregulation) were similarly reduced in TgNotch3(R169C) and TgBAC-TIMP3 mice, and myogenic responses of brain arteries were likewise attenuated. These defects were rescued in TgNotch3(R169C) mice by haploinsufficiency of Timp3, although the number of white matter lesions was unaffected. In contrast, haploinsufficiency or loss of vitronectin in TgNotch3(R169C) mice ameliorated white matter lesions, although CBF responses were unchanged. Amelioration of cerebrovascular reactivity or white matter lesions in these mice was not associated with reduced Notch3(ECD) deposition in brain vessels.

INTERPRETATION

Elevated levels of TIMP3 and vitronectin, acting downstream of Notch3(ECD) deposition, play a role in CADASIL, producing divergent influences on early CBF deficits and later white matter lesions.

Dynamic regulation of plasma matrix metalloproteinases in human diabetic ketoacidosis

BACKGROUND

Diabetic ketoacidosis (DKA) in children is associated with cerebrovascular-related complications. We recently reported that DKA facilitates leukocyte adherence to the brain microvascular endothelium. Adhered leukocytes can release enzymes that instigate vascular dysfunction. Our aims were to measure plasma levels of leukocyte-derived matrix metalloproteinases (MMPs) from DKA patients and to correlate plasma MMP concentrations with DKA severity.

METHODS

Plasma was obtained from children with type 1 diabetes, either in DKA (n = 16) or insulin controlled (CON; n = 16). Antibody microarray and gelatin zymography were used to quantify plasma MMPs and their endogenous tissue inhibitors (TIMPs). MMP concentrations were correlated with DKA severity (blood pH). Quantitative PCR of leukocyte mRNA was used to help determine the origin of plasma MMPs.

RESULTS

DKA was associated with altered plasma levels of ↓MMP-2 (P < 0.001), ↑MMP-8 (P < 0.001), ↑MMP-9 (P < 0.05), and ↑TIMP-4 (P < 0.001), as compared with CON. Elevated MMP-8 and MMP-9 were both positively correlated with DKA severity (P < 0.05). DKA was associated with increased leukocyte mRNA for MMP-8, MMP-9, and TIMP-4 (P < 0.005).

CONCLUSION

MMPs are dynamically regulated during DKA. Plasma MMP-8 and MMP-9 concentrations correlate with DKA severity and are known to degrade brain microvascular endothelial cell tight junctions. Thus, leukocyte-derived MMPs might contribute to DKA-associated cerebrovascular complications.

TIMP4 Modulates ER-α Signalling in MCF7 Breast Cancer Cells

Tissue inhibitor of metalloprotease 4 (TIMP4) contributes to poor prognosis in breast and other tumours. However, the mechanisms of how TIMP4 influences breast cancer cell behaviour are unknown. Our aim was to explore the signalling pathways modulated by TIMP4 in breast cancer cells. Human recombinant TIMP4 was added to MCF7 breast cancer cells and RNASeq was performed. TIMP4 RNASeq results were validated by RT-PCR. Network analyses of TIMP4-exposed cells showed that ER-α, HIF1A and TGF-β signalling were activated, whereas FOXO3 signalling was downregulated. ER-α protein levels were increased and concordantly, promoters of TIMP4-upregulated genes were significantly enriched in oestrogen-binding sites. We concluded that TIMP4 modulates multiple signalling pathways relevant in cancer in MCF7 cells, including the ER-α cascade.