Loss of TIMP3 exacerbates atherosclerosis in ApoE null mice

ECM Microenvironment in Vascular Homeostasis: New Targets for Atherosclerosis

Alterations in vascular extracellular matrix (ECM) components, interactions, and mechanical properties influence both the formation and stability of atherosclerotic plaques. This review discusses the contribution of the ECM microenvironment in vascular homeostasis and remodeling in atherosclerosis, highlighting Cartilage oligomeric matrix protein (COMP) and its degrading enzyme ADAMTS7 as examples, and proposes potential avenues for future research aimed at identifying novel therapeutic targets for atherosclerosis based on the ECM microenvironment.

Flow-induced reprogramming of endothelial cells in atherosclerosis

Atherosclerotic diseases such as myocardial infarction, ischaemic stroke and peripheral artery disease continue to be leading causes of death worldwide despite the success of treatments with cholesterol-lowering drugs and drug-eluting stents, raising the need to identify additional therapeutic targets. Interestingly, atherosclerosis preferentially develops in curved and branching arterial regions, where endothelial cells are exposed to disturbed blood flow with characteristic low-magnitude oscillatory shear stress. By contrast, straight arterial regions exposed to stable flow, which is associated with high-magnitude, unidirectional shear stress, are relatively well protected from the disease through shear-dependent, atheroprotective endothelial cell responses. Flow potently regulates structural, functional, transcriptomic, epigenomic and metabolic changes in endothelial cells through mechanosensors and mechanosignal transduction pathways. A study using single-cell RNA sequencing and chromatin accessibility analysis in a mouse model of flow-induced atherosclerosis demonstrated that disturbed flow reprogrammes arterial endothelial cells in situ from healthy phenotypes to diseased ones characterized by endothelial inflammation, endothelial-to-mesenchymal transition, endothelial-to-immune cell-like transition and metabolic changes. In this Review, we discuss this emerging concept of disturbed-flow-induced reprogramming of endothelial cells (FIRE) as a potential pro-atherogenic mechanism. Defining the flow-induced mechanisms through which endothelial cells are reprogrammed to promote atherosclerosis is a crucial area of research that could lead to the identification of novel therapeutic targets to combat the high prevalence of atherosclerotic disease.

Potential role of soluble CD40 receptor in chronic inflammatory diseases

The CD40 receptor and its ligand CD154 are widely expressed in various immune-competent cells. Interaction of CD154 with CD40 is essential for B-cell growth, differentiation, and immunoglobulin class switching. Many other immune-competent cells involved in innate and adaptive immunity communicate through this co-stimulatory ligand-receptor dyad. CD40-CD154 interaction is involved in the pathogenesis of numerous inflammatory and autoimmune diseases. While CD40 and CD154 are membrane-bound proteins, their soluble counterparts are generated by proteolytic cleavage or alternative splicing. This review summarises current knowledge about the impact of single nucleotide polymorphisms in the human CD40 gene and compensatory changes in the plasma level of the soluble CD40 receptor (sCD40) isoform in related pro-inflammatory diseases. It discusses regulation patterns of the disintegrin metalloprotease ADAM17 function leading to ectodomain shedding of transmembrane proteins, such as pro-inflammatory adhesion molecules or CD40. The role of sCD40 as a potential biomarker for chronic inflammatory diseases will also be discussed.

Organism-wide, cell-type-specific secretome mapping of exercise training in mice

There is a significant interest in identifying blood-borne factors that mediate tissue crosstalk and function as molecular effectors of physical activity. Although past studies have focused on an individual molecule or cell type, the organism-wide secretome response to physical activity has not been evaluated. Here, we use a cell-type-specific proteomic approach to generate a 21-cell-type, 10-tissue map of exercise training-regulated secretomes in mice. Our dataset identifies >200 exercise training-regulated cell-type-secreted protein pairs, the majority of which have not been previously reported. Pdgfra-cre-labeled secretomes were the most responsive to exercise training. Finally, we show anti-obesity, anti-diabetic, and exercise performance-enhancing activities for proteoforms of intracellular carboxylesterases whose secretion from the liver is induced by exercise training.

The Role of ADAM17 in Inflammation-Related Atherosclerosis

Atherosclerosis is a chronic inflammatory disease that poses a huge economic burden due to its extremely poor prognosis. Therefore, it is necessary to explore potential mechanisms to improve the prevention and treatment of atherosclerosis. A disintegrin and metalloprotease 17 (ADAM17) is a cell membrane-bound protein that performs a range of functions through membrane protein shedding and intracellular signaling. ADAM17-mediated inflammation has been identified to be an important contributor to atherosclerosis; however, the specific relationship between its multiple regulatory roles and the pathogenesis of atherosclerosis remains unclear. Here, we reviewed the activation, function, and regulation of ADAM17, described in detail the role of ADAM17-mediated inflammatory damage in atherosclerosis, and discussed several controversial points. We hope that these insights into ADAM17 biology will lead to rational management of atherosclerosis. ADAM17 promotes vascular inflammation in endothelial cells, smooth muscle cells, and macrophages, and regulates the occurrence and development of atherosclerosis.

Protective Effects of Circulating TIMP3 on Coronary Artery Disease and Myocardial Infarction: A Mendelian Randomization Study

Tissue inhibitor of metalloproteinase 3 (TIMP3) is a protease with high expression levels in the heart and plays an essential role in extracellular matrix turnover by maintaining equilibrium with matrix metalloproteinases. Considerable data in experimental models have demonstrated a protective role of TIMP3 in coronary artery disease (CAD) and myocardial infarction (MI). However, causality remains unexplored in population studies. Here, we sought to decipher the potential causality between TIMP3 and CAD/MI using the Mendelian randomization (MR) method. We extracted summary−level datasets for TIMP3 and CAD/MI from the genome−wide association studies performed in the KORA study and CARDIoGRAMplusC4D consortium, respectively. Seven independent SNPs were obtained as instrumental variables for TIMP3. The MR analyses were replicated using FinnGen datasets, and the main results were combined in meta−analyses. Elevated genetically predicted serum TIMP3 levels were causally associated with a lower risk of CAD [odds ratio (OR), 0.97; 95% confidence interval (CI), 0.95, 0.98; p = 5.29 × 10⁻⁵] and MI (OR, 0.96; 95% CI, 0.95, 0.98; p = 3.85 × 10⁻⁵). The association patterns persisted in the meta−analyses combining the different datasets (CAD: OR, 0.97; 95% CI, 0.96, 0.99; p = 4.37 × 10⁻⁵; MI: OR, 0.97; 95% CI, 0.96, 0.99; p = 9.96 × 10⁻⁵) and was broadly consistent across a set of complementary analyses. Evidence of heterogeneity and horizontal pleiotropy was limited for all associations considered. In conclusion, this MR study supports inverse causal associations between serum TIMP3 and the risk of CAD and MI. Strategies for raising TIMP3 levels may offer new avenues for the prevention strategies of atherosclerotic cardiovascular diseases.

Theories and Molecular Basis of Vascular Aging: A Review of the Literature from VascAgeNet Group on Pathophysiological Mechanisms of Vascular Aging

Vascular aging, characterized by structural and functional alterations of the vascular wall, is a hallmark of aging and is tightly related to the development of cardiovascular mortality and age-associated vascular pathologies. Over the last years, extensive and ongoing research has highlighted several sophisticated molecular mechanisms that are involved in the pathophysiology of vascular aging. A more thorough understanding of these mechanisms could help to provide a new insight into the complex biology of this non-reversible vascular process and direct future interventions to improve longevity. In this review, we discuss the role of the most important molecular pathways involved in vascular ageing including oxidative stress, vascular inflammation, extracellular matrix metalloproteinases activity, epigenetic regulation, telomere shortening, senescence and autophagy.

Peripheral apoE4 enhances Alzheimer's pathology and impairs cognition by compromising cerebrovascular function

The ε4 allele of the apolipoprotein E (APOE) gene, a genetic risk factor for Alzheimer's disease, is abundantly expressed in both the brain and periphery. Here, we present evidence that peripheral apoE isoforms, separated from those in the brain by the blood-brain barrier, differentially impact Alzheimer's disease pathogenesis and cognition. To evaluate the function of peripheral apoE, we developed conditional mouse models expressing human APOE3 or APOE4 in the liver with no detectable apoE in the brain. Liver-expressed apoE4 compromised synaptic plasticity and cognition by impairing cerebrovascular functions. Plasma proteome profiling revealed apoE isoform-dependent functional pathways highlighting cell adhesion, lipoprotein metabolism and complement activation. ApoE3 plasma from young mice improved cognition and reduced vessel-associated gliosis when transfused into aged mice, whereas apoE4 compromised the beneficial effects of young plasma. A human induced pluripotent stem cell-derived endothelial cell model recapitulated the plasma apoE isoform-specific effect on endothelial integrity, further supporting a vascular-related mechanism. Upon breeding with amyloid model mice, liver-expressed apoE4 exacerbated brain amyloid pathology, whereas apoE3 reduced it. Our findings demonstrate pathogenic effects of peripheral apoE4, providing a strong rationale for targeting peripheral apoE to treat Alzheimer's disease.

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.

Cosmeceutical Therapy: Engaging the Repercussions of UVR Photoaging on the Skin's Circadian Rhythm

Sunlight is an important factor in regulating the central circadian rhythm, including the modulation of our sleep/wake cycles. Sunlight had also been discovered to have a prominent influence on our skin’s circadian rhythm. Overexposure or prolonged exposure to the sun can cause skin photodamage, such as the formation of irregular pigmentation, collagen degradation, DNA damage, and even skin cancer. Hence, this review will be looking into the detrimental effects of sunlight on our skin, not only at the aspect of photoaging but also at its impact on the skin’s circadian rhythm. The growing market trend of natural-product-based cosmeceuticals as also caused us to question their potential to modulate the skin’s circadian rhythm. Questions about how the skin’s circadian rhythm could counteract photodamage and how best to maximize its biopotential will be discussed in this article. These discoveries regarding the skin’s circadian rhythm have opened up a completely new level of understanding of our skin’s molecular mechanism and may very well aid cosmeceutical companies, in the near future, to develop better products that not only suppress photoaging but remain effective and relevant throughout the day.

Tissue Inhibitor of Metalloproteases 3 (TIMP-3): In Vivo Analysis Underpins Its Role as a Master Regulator of Ectodomain Shedding

The proteolytical cleavage of transmembrane proteins with subsequent release of their extracellular domain, so-called ectodomain shedding, is a post-translational modification that plays an essential role in several biological processes, such as cell communication, adhesion and migration. Metalloproteases are major proteases in ectodomain shedding, especially the disintegrin metalloproteases (ADAMs) and the membrane-type matrix metalloproteases (MT-MMPs), which are considered to be canonical sheddases for their membrane-anchored topology and for the large number of proteins that they can release. The unique ability of TIMP-3 to inhibit different families of metalloproteases, including the canonical sheddases (ADAMs and MT-MMPs), renders it a master regulator of ectodomain shedding. This review provides an overview of the different functions of TIMP-3 in health and disease, with a major focus on the functional consequences in vivo related to its ability to control ectodomain shedding. Furthermore, herein we describe a collection of mass spectrometry-based approaches that have been used in recent years to identify new functions of sheddases and TIMP-3. These methods may be used in the future to elucidate the pathological mechanisms triggered by the Sorsby’s fundus dystrophy variants of TIMP-3 or to identify proteins released by less well characterized TIMP-3 target sheddases whose substrate repertoire is still limited, thus providing novel insights into the physiological and pathological functions of the inhibitor.

Tissue Inhibitor of Metalloproteinase-3 Ameliorates Diabetes-Induced Retinal Inflammation

Purpose: Endogenous tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) has powerful regulatory effects on inflammation and angiogenesis. In this study, we investigated the role of TIMP-3 in regulating inflammation in the diabetic retina.

Methods: Vitreous samples from patients with proliferative diabetic retinopathy (PDR) and non-diabetic patients were subjected to Western blot analysis. Streptozotocin-treated rats were used as a preclinical diabetic retinopathy (DR) model. Blood-retinal barrier (BRB) breakdown was assessed with fluorescein isothiocyanate (FITC)-conjugated dextran. Rat retinas, human retinal microvascular endothelial cells (HRMECs) and human retinal Müller glial cells were studied by Western blot analysis and ELISA. Adherence of human monocytes to HRMECs was assessed and in vitro angiogenesis assays were performed.

Results: Tissue inhibitor of matrix metalloproteinase-3 in vitreous samples was largely glycosylated. Intravitreal injection of TIMP-3 attenuated diabetes-induced BRB breakdown. This effect was associated with downregulation of diabetes-induced upregulation of the p65 subunit of NF-κB, intercellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF), whereas phospho-ERK1/2 levels were not altered. In Müller cell cultures, TIMP-3 significantly attenuated VEGF upregulation induced by high-glucose (HG), the hypoxia mimetic agent cobalt chloride (CoCl₂) and TNF-α and attenuated MCP-1 upregulation induced by CoCl₂ and TNF-α, but not by HG. TIMP-3 attenuated HG-induced upregulation of phospho-ERK1/2, caspase-3 and the mature form of ADAM17, but not the levels of the p65 subunit of NF-κB and the proform of ADAM17 in Müller cells. TIMP-3 significantly downregulated TNF-α-induced upregulation of ICAM-1 and VCAM-1 in HRMECs. Accordingly, TIMP-3 significantly decreased spontaneous and TNF-α- and VEGF-induced adherence of monocytes to HRMECs. Finally, TIMP-3 significantly attenuated VEGF-induced migration, chemotaxis and proliferation of HRMECs.

Conclusion:In vitro and in vivo data point to anti-inflammatory and anti-angiogenic effects of TIMP-3 and support further studies for its applications in the treatment of DR.

Delivery of Anti-microRNA-712 to Inflamed Endothelial Cells Using Poly(β-amino ester) Nanoparticles Conjugated with VCAM-1 Targeting Peptide

Endothelial cells (ECs) are an important target for therapy in a wide range of diseases, most notably atherosclerosis. Developing efficient nanoparticle (NP) systems that deliver RNA interference (RNAi) drugs specifically to dysfunctional ECs in vivo to modulate their gene expression remains a challenge. To date, several lipid-based NPs are developed and shown to deliver RNAi to ECs, but few of them are optimized to specifically target dysfunctional endothelium. Here, a novel, targeted poly(β-amino ester) (pBAE) NP is demonstrated. This pBAE NP is conjugated with VHPK peptides that target vascular cell adhesion molecule 1 protein, overexpressed on inflamed EC membranes. To test this approach, the novel NPs are used to deliver anti-microRNA-712 (anti-miR-712) specifically to inflamed ECs both in vitro and in vivo, reducing the high expression of pro-atherogenic miR-712. A single administration of anti-miR-712 using the VHPK-conjugated-pBAE NPs in mice significantly reduce miR-712 expression, while preventing the loss of its target gene, tissue inhibitor of metalloproteinase 3 (TIMP3) in inflamed endothelium. miR-712 and TIMP3 expression are unchanged in non-inflamed endothelium. This novel, targeted-delivery platform may be used to deliver RNA therapeutics specifically to dysfunctional endothelium for the treatment of vascular disease.

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

[Figure: see text].

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

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

A Pulsatile Flow System to Engineer Aneurysm and Atherosclerosis Mimetic Extracellular Matrix

Alterations of blood flow patterns strongly correlate with arterial wall diseases such as atherosclerosis and aneurysm. Here, a simple, pumpless, close-loop, easy-to-replicate, and miniaturized flow device is introduced to concurrently expose 3D engineered vascular smooth muscle tissues to high-velocity pulsatile flow versus low-velocity disturbed flow conditions. Two flow regimes are distinguished, one that promotes elastin and impairs collagen I assembly, while the other impairs elastin and promotes collagen assembly. This latter extracellular matrix (ECM) composition shares characteristics with aneurysmal or atherosclerotic tissue phenotypes, thus recapitulating crucial hallmarks of flow-induced tissue morphogenesis in vessel walls. It is shown that the mRNA levels of ECM of collagens and elastin are not affected by the differential flow conditions. Instead, the differential gene expression of matrix metalloproteinase (MMP) and their inhibitors (TIMPs) is flow-dependent, and thus drives the alterations in ECM composition. In further support, treatment with doxycycline, an MMP inhibitor and a clinically used drug to treat vascular diseases, halts the effect of low-velocity flow on the ECM remodeling. This illustrates how the platform can be exploited for drug efficacy studies by providing crucial mechanistic insights into how different therapeutic interventions may affect tissue growth and ECM assembly.

Tissue Inhibitor of Metalloproteinase 3 Deficiency Disrupts the Hepatocyte E-Cadherin/β-Catenin Complex and Induces Cell Death in Liver Ischemia/Reperfusion Injury

Tissue inhibitor of metalloproteinase (TIMP) 3 is a naturally occurring inhibitor of a broad range of proteases, with key roles in extracellular matrix turnover and in the pathogenesis of various diseases. In this study, we investigated the response of mice lacking TIMP3 (TIMP3-/-) to hepatic ischemia/reperfusion injury (IRI). We report here that TIMP3-/- mice showed an enhanced inflammatory response, exacerbated organ damage, and further impaired liver function after IRI when compared with their wild-type littermates. Loss of TIMP3 led to the cleavage and shedding of E-cadherin during hepatic IRI; the full-length 120-kDa E-cadherin and the ratio of 38-kDa C-terminal fragment/120-kDa E-cadherin were decreased and increased, respectively, in TIMP3-/- livers after IRI. Moreover, GI254023X, a potent inhibitor of a disintegrin and metalloprotease (ADAM) 10, was capable of partially rescuing the expression of E-cadherin in the TIMP3-null hepatocytes. The proteolysis of E-cadherin in the TIMP3-/- livers was also linked to the loss of β-catenin from the hepatocyte membranes and to an increased susceptibility to apoptosis after liver IRI. In a similar fashion, depression of the E-cadherin/β-catenin complex mediated by TIMP3 deletion and knockdown of β-catenin by small interfering RNA were both capable of inducing caspase activation in isolated hepatocytes subjected to H₂ O₂ oxidative stress. Hence, these results support a protective role for TIMP3 expression in sheltering the hepatocyte E-cadherin/β-catenin complex from proteolytic processing and inhibiting apoptosis after hepatic IRI.

LRP1 Controls TNF Release via the TIMP-3/ADAM17 Axis in Endotoxin-Activated Macrophages

The metalloproteinase ADAM17 plays a pivotal role in initiating inflammation by releasing TNF from its precursor. Prolonged TNF release causes many chronic inflammatory diseases, indicating that tight regulation of ADAM17 activity is essential for resolution of inflammation. In this study, we report that the endogenous ADAM17 inhibitor TIMP-3 inhibits ADAM17 activity only when it is bound to the cell surface and that cell surface levels of TIMP-3 in endotoxin-activated human macrophages are dynamically controlled by the endocytic receptor LRP1. Pharmacological blockade of LRP1 inhibited endocytic clearance of TIMP-3, leading to an increase in cell surface levels of the inhibitor that blocked TNF release. Following LPS stimulation, TIMP-3 levels on the surface of macrophages increased 4-fold within 4 h and continued to accumulate at 6 h, before a return to baseline levels at 8 h. This dynamic regulation of cell surface TIMP-3 levels was independent of changes in TIMP-3 mRNA levels, but correlated with shedding of LRP1. These results shed light on the basic mechanisms that maintain a regulated inflammatory response and ensure its timely resolution.

Effects of caloric restriction on neuropathic pain, peripheral nerve degeneration and inflammation in normometabolic and autophagy defective prediabetic Ambra1 mice

There is a growing interest on the role of autophagy in diabetes pathophysiology, where development of neuropathy is one of the most frequent comorbidities. We have previously demonstrated that neuropathic pain after nerve damage is exacerbated in autophagy-defective heterozygous Ambra1 mice. Here, we show the existence of a prediabetic state in Ambra1 mice, characterized by hyperglycemia, intolerance to glucose and insulin resistance. Thus, we further investigate the hypothesis that prediabetes may account for the exacerbation of allodynia and chronic pain and that counteracting the autophagy deficit may relieve the neuropathic condition. We took advantage from caloric restriction (CR) able to exert a double action: a powerful increase of autophagy and a control on the metabolic status. We found that CR ameliorates neuropathy throughout anti-inflammatory and metabolic mechanisms both in Ambra1 and in WT animals subjected to nerve injury. Moreover, we discovered that nerve lesion represents, per se, a metabolic stressor and CR reinstates glucose homeostasis, insulin resistance, incomplete fatty acid oxidation and energy metabolism. As autophagy inducer, CR promotes and anticipates Schwann cell autophagy via AMP-activated protein kinase (AMPK) that facilitates remyelination in peripheral nerve. In summary, we provide new evidence for the role of autophagy in glucose metabolism and identify in energy depletion by dietary restriction a therapeutic approach in the fight against neuropathic pain.

Metabolomic Signature in Sera of Multiple Sclerosis Patients during Pregnancy

Multiple sclerosis (MuS) is an autoimmune disease of the central nervous system characterized by neuroinflammation, neurodegeneration, and degradation of the myelin sheath. Epidemiological studies have shown that the female gender is more susceptible than the male gender to MuS development, with a female-to-male ratio of 2:1. Despite this high onset, women have a better prognosis than men, and the frequency of the relapsing phase decreases during pregnancy, while it increases soon after birth. Therefore, it is interesting to investigate hormonal fluctuations during pregnancy and whether they correlate with metabolic signatures. To gain a deeper inside into the biochemical mechanism of such a multifactorial disease, we adopted targeted metabolomics approaches for the determination of many serum metabolites in 12 pregnant women affected by MuS by mass spectrometry analysis. Our data show a characteristic hormonal fluctuation for estrogens and progesterone, as expected. They also highlight other interesting hormonal alterations for cortisol, corticosterone, 11-deoxycortisol, 4-androstene-3,17-dione, testosterone, and 17α-hydroxyprogesterone. Furthermore, a negative correlation with progesterone levels was observed for amino acids and for acylcarnitines, while an imbalance of different sphingolipids pathways was found during pregnancy. In conclusion, these data are in agreement with the characteristic clinical signs of MuS patients during pregnancy and, if confirmed, they may add an important tessera in the complex mosaic of maternal neuroprotection.

Compartment-resolved Proteomic Analysis of Mouse Aorta during Atherosclerotic Plaque Formation Reveals Osteoclast-specific Protein Expression

Atherosclerosis leads to vascular lesions that involve major rearrangements of the vascular proteome, especially of the extracellular matrix (ECM). Using single aortas from ApoE knock out mice, we quantified formation of plaques by single-run, high-resolution mass spectrometry (MS)-based proteomics. To probe localization on a proteome-wide scale we employed quantitative detergent solubility profiling. This compartment- and time-resolved resource of atherogenesis comprised 5117 proteins, 182 of which changed their expression status in response to vessel maturation and atherosclerotic plaque development. In the insoluble ECM proteome, 65 proteins significantly changed, including relevant collagens, matrix metalloproteinases and macrophage derived proteins. Among novel factors in atherosclerosis, we identified matrilin-2, the collagen IV crosslinking enzyme peroxidasin as well as the poorly characterized MAM-domain containing 2 (Mamdc2) protein as being up-regulated in the ECM during atherogenesis. Intriguingly, three subunits of the osteoclast specific V-ATPase complex were strongly increased in mature plaques with an enrichment in macrophages thus implying an active de-mineralization function.

Dietary rose hip exerts antiatherosclerotic effects and increases nitric oxide-mediated dilation in ApoE-null mice

Atherosclerosis is a disease in which atheromatous plaques develop inside arteries, leading to reduced or obstructed blood flow that in turn may cause stroke and heart attack. Rose hip is the fruit of plants of the genus Rosa, belonging to the Rosaceae family, and it is rich in antioxidants with high amounts of ascorbic acid and phenolic compounds. Several studies have shown that fruits, seeds and roots of these plants exert antidiabetic, antiobesity and cholesterol-lowering effects in rodents as well as humans. The aim of this study was to elucidate the mechanisms by which rose hip lowers plasma cholesterol and to evaluate its effects on atherosclerotic plaque formation. ApoE-null mice were fed either an HFD (CTR) or HFD with rose hip supplementation (RH) for 24 weeks. At the end of the study, we found that blood pressure and atherosclerotic plaques, together with oxidized LDL, total cholesterol and fibrinogen levels were markedly reduced in the RH group. Fecal cholesterol content, liver expression of Ldlr and selected reverse cholesterol transport (RCT) genes such as Abca1, Abcg1 and Scarb1 were significantly increased upon RH feeding. In the aorta, the scavenger receptor Cd36 and the proinflammatory Il1β genes were markedly down-regulated compared to the CTR mice. Finally, we found that RH increased nitric oxide-mediated dilation of the caudal artery. Taken together, these results suggest that rose hip is a suitable dietary supplement for preventing atherosclerotic plaques formation by modulating systemic blood pressure and the expression of RCT and inflammatory genes.

Evidence for the Involvement of Matrix-Degrading Metalloproteinases (MMPs) in Atherosclerosis

Atherosclerosis leads to blockage of arteries, culminating in myocardial infarction, and stroke. The involvement of matrix-degrading metalloproteinases (MMPs) in atherosclerosis is established and many studies have highlighted the importance of various MMPs in this process. MMPs were first implicated in atherosclerosis due to their ability to degrade extracellular matrix components, which can lead to increased plaque instability. However, more recent work has highlighted a multitude of roles for MMPs in addition to breakdown of extracellular matrix proteins. MMPs are now known to be involved in various stages of plaque progression: from initial macrophage infiltration to plaque rupture. This chapter summarizes the development and progression of atherosclerotic plaques and the contribution of MMPs. We provide data from human studies showing the effect of MMP polymorphisms and the expression of MMPs in both the atherosclerotic plaque and within plasma. We also discuss work in animal models of atherosclerosis that show the effect of gain or loss of function of MMPs. Together, the data provided from these studies illustrate that MMPs are ideal targets as both biomarkers and potential drug therapies for atherosclerosis.

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.

Proteomic definitions of basement membrane composition in health and disease

Basement membranes are formed from condensed networks of extracellular matrix (ECM) proteins. These structures underlie all epithelial, mesothelial and endothelial sheets and provide an essential structural scaffold. Candidate-based investigations have established that predominant components of basement membranes are laminins, collagen type IV, nidogens and heparan sulphate proteoglycans. More recently, global proteomic approaches have been applied to investigate ECM and these analyses confirm tissue-specific ECM proteomes with a high degree of complexity. The proteomes consist of structural as well as regulatory ECM proteins such as proteases and growth factors. This review is focused on the proteomic analysis of basement membranes and illustrates how this approach can be used to build our understanding of ECM regulation in health and disease.

MicroRNA-181b Controls Atherosclerosis and Aneurysms Through Regulation of TIMP-3 and Elastin

Supplemental Digital Content is available in the text.

Rationale:

Atherosclerosis and aneurysms are leading causes of mortality worldwide. MicroRNAs (miRs) are key determinants of gene and protein expression, and atypical miR expression has been associated with many cardiovascular diseases; although their contributory role to atherosclerotic plaque and abdominal aortic aneurysm stability are poorly understood.

Objective:

To investigate whether miR-181b regulates tissue inhibitor of metalloproteinase-3 expression and affects atherosclerosis and aneurysms.

Methods and Results:

Here, we demonstrate that miR-181b was overexpressed in symptomatic human atherosclerotic plaques and abdominal aortic aneurysms and correlated with decreased expression of predicted miR-181b targets, tissue inhibitor of metalloproteinase-3, and elastin. Using the well-characterized mouse atherosclerosis models of Apoe^−/− and Ldlr^−/−, we observed that in vivo administration of locked nucleic acid anti-miR-181b retarded both the development and the progression of atherosclerotic plaques. Systemic delivery of anti-miR-181b in angiotensin II–infused Apoe^−/− and Ldlr^−/− mice attenuated aneurysm formation and progression within the ascending, thoracic, and abdominal aorta. Moreover, miR-181b inhibition greatly increased elastin and collagen expression, promoting a fibrotic response and subsequent stabilization of existing plaques and aneurysms. We determined that miR-181b negatively regulates macrophage tissue inhibitor of metalloproteinase-3 expression and vascular smooth muscle cell elastin production, both important factors in maintaining atherosclerotic plaque and aneurysm stability. Validation studies in Timp3^−/− mice confirmed that the beneficial effects afforded by miR-181b inhibition are largely tissue inhibitor of metalloproteinase-3 dependent, while also revealing an additional protective effect through elevating elastin synthesis.

Conclusions:

Our findings suggest that the management of miR-181b and its target genes provides therapeutic potential for limiting the progression of atherosclerosis and aneurysms and protecting them from rupture.

Plaque Size Is Decreased but M1 Macrophage Polarization and Rupture Related Metalloproteinase Expression Are Maintained after Deleting T-Bet in ApoE Null Mice

Background

Thelper1 (Th1) lymphocytes have been previously implicated in atherosclerotic plaque growth but their role in plaque vulnerability to rupture is less clear. We investigated whether T-bet knockout that prevents Th1 lymphocyte differentiation modulates classical (M1) macrophage activation or production of matrix degrading metalloproteinases (MMPs) and their tissue inhibitors, TIMPs.

Methods & Results

We studied the effect of T-bet deletion in apolipoproteinE (ApoE) knockout mice fed a high fat diet (HFD) or normal chow diet (ND). Transcript levels of M1/M2 macrophage polarization markers, selected MMPs and TIMPs were measured by RT-qPCR in macrophages isolated from subcutaneous granulomas or in whole aortae. Immunohistochemistry of aortic sinus (AS) and brachiocephalic artery (BCA) plaques was conducted to quantify protein expression of the same factors.

Deletion of T-bet decreased mRNA for the M1 marker NOS-2 in granuloma macrophages but levels of M2 markers (CD206, arginase-1 and Ym-1), MMPs-2, -9, -12, -13, -14 and -19 or TIMPs-1 to -3 were unchanged. No mRNA differences were observed in aortic extracts from mice fed a HFD for 12 weeks. Moreover, AS and BCA plaques were similarly sized between genotypes, and had similar areas stained for NOS-2, COX-2, MMP-12 and MMP-14 proteins. T-bet deletion increased MMP-13, MMP-14 and arginase-1 in AS plaques. After 35 weeks of ND, T-bet deletion reduced the size of AS and BCA plaques but there were no differences in the percentage areas stained for M1 or M2 markers, MMPs-12, -13, -14, or TIMP-3.

Conclusions

Absence of Th1 lymphocytes is associated with reduced plaque size in ApoE knockout mice fed a normal but not high fat diet. In either case, M1 macrophage polarization and expression of several MMPs related to plaque instability are either maintained or increased.

Gene silencing of TACE enhances plaque stability and improves vascular remodeling in a rabbit model of atherosclerosis

We aimed to test the hypothesis that gene silencing of tumor necrosis factor alpha converting enzyme (TACE) may attenuate lesion inflammation and positive vascular remodeling and enhance plaque stability in a rabbit model of atherosclerosis. Lentivirus-mediated TACE shRNA was injected into the abdominal aortic plaques of rabbits which effectively down-regulated TACE expression and activities from week 8 to week 16. TACE gene silencing reduced remodeling index and plaque burden, and diminished the content of macrophages and lipids while increased that of smooth muscle cells and collagen in the aortic plaques. In addition, TACE gene silencing attenuated the local expression of P65, iNOS, ICAM-1, VEGF and Flt-1 and activities of MMP9 and MMP2 while increased the local expression of TGF-β1 together with reduced number of neovessels in the aorta. TACE shRNA treatment resulted in down-regulated expression of TACE in macrophages and blunted ERK-P38 phosphorylation and tube formation of co-cultured mouse vascular smooth muscle cells or human umbilical vein endothelial cells. In conclusion, gene silencing of TACE enhanced plaque stability and improved vascular positive remodeling. The mechanisms may involve attenuated local inflammation, neovascularization and MMP activation, as well as enhanced collagen production probably via down-regulated ERK-NF-κB and up-regulated TGF-β1 signaling pathways.

Prospect and progress of gene therapy in treating atherosclerosis

INTRODUCTION

Despite considerable improvements in therapies, atherosclerotic cardiovascular diseases remain the leading cause of death worldwide. Therefore, in addition to current treatment options, new therapeutic approaches are still needed.

AREAS COVERED

In this review, novel gene and RNA interference-based therapy approaches and promising target genes for treating atherosclerosis are addressed. In addition, relevant animal models for the demonstration of the efficacy of different gene therapy applications, and current progress toward more efficient, targeted and safer gene transfer vectors are reviewed.

EXPERT OPINION

Atherosclerosis represents a complex multifactorial disease that is dependent on the interplay between lipoprotein metabolism, cellular reactions and inflammation. Recent advances and novel targets, especially in the field of RNA interference-based therapies, are very promising. However, it should be noted that the modulation of a particular gene is not as clearly associated with a complex polygenic disease as it is in the case of monogenic diseases. A deeper understanding of molecular mechanisms of atherosclerosis, further progress in vector development and the demonstration of treatment efficacy in relevant animal models will be required before gene therapy of atherosclerosis meets its clinical reality.

TIMP3 interplays with apelin to regulate cardiovascular metabolism in hypercholesterolemic mice

OBJECTIVE

Tissue inhibitor of metalloproteinase 3 (TIMP3) is an extracellular matrix (ECM) bound protein, which has been shown to be downregulated in human subjects and experimental models with cardiometabolic disorders, including type 2 diabetes mellitus, hypertension and atherosclerosis. The aim of this study was to investigate the effects of TIMP3 on cardiac energy homeostasis during increased metabolic stress conditions.

METHODS

ApoE(-/-)TIMP3(-/-) and ApoE(-/-) mice on a C57BL/6 background were subjected to telemetric ECG analysis and experimental myocardial infarction as models of cardiac stress induction. We used Western blot, qRT-PCR, histology, metabolomics, RNA-sequencing and in vivo phenotypical analysis to investigate the molecular mechanisms of altered cardiac energy metabolism.

RESULTS

ApoE(-/-)TIMP3(-/-) revealed decreased lifespan. Telemetric ECG analysis showed increased arrhythmic episodes, and experimental myocardial infarction by left anterior descending artery (LAD) ligation resulted in increased peri-operative mortality together with increased scar formation, ventricular dilatation and a reduction of cardiac function after 4 weeks in the few survivors. Hearts of ApoE(-/-)TIMP3(-/-) exhibited accumulation of neutral lipids when fed a chow diet, which was exacerbated by a high fat, high cholesterol diet. Metabolomics analysis revealed an increase in circulating markers of oxidative stress with a reduction in long chain fatty acids. Using whole heart mRNA sequencing, we identified apelin as a putative modulator of these metabolic defects. Apelin is a regulator of fatty acid oxidation, and we found a reduction in the levels of enzymes involved in fatty acid oxidation in the left ventricle of ApoE(-/-)TIMP3(-/-) mice. Injection of apelin restored the hitherto identified metabolic defects of lipid oxidation.

CONCLUSION

TIMP3 regulates lipid metabolism as well as oxidative stress response via apelin. These findings therefore suggest that TIMP3 maintains metabolic flexibility in the heart, particularly during episodes of increased cardiac stress.

Attenuation of atherosclerotic lesions in diabetic apolipoprotein E-deficient mice using gene silencing of macrophage migration inhibitory factor

Macrophage migration inhibitory factor (MIF) involves the pathogenesis of atherosclerosis (AS) and increased plasma MIF levels in diabetes mellitus (DM) patients are associated with AS. Here, we have been suggested that MIF could be a critical contributor for the pathological process of diabetes-associated AS by using adenovirus-mediated RNA interference. First, streptozotocin (STZ)-induced diabetic animal model was constructed in 114 apolipoprotein E-deficient mice (apoE−/− mice) fed on a regular chow diet. Then, the animals were randomly divided into three groups: Adenovirus-mediated MIF interference (Ad-MIFi), Ad-enhanced green fluorescent protein (EGFP) and normal saline (NS) group (n ≈ 33/group). Non-diabetic apoE−/− mice (n = 35) were served as controls. Ad-MIFi, Ad-EGFP and NS were, respectively, injected into the tail vein of mice from Ad-MIFi, Ad-EGFP and NS group, which were injected repeatedly 4 weeks later. Physical, biochemical, morphological and molecular parameters were measured. The results showed that diabetic apoE−/− mice had significantly aggravated atherosclerotic lesions. MIF gene interference attenuated atherosclerotic lesions and stabilized atheromatous plaque, accompanied by the decreased macrophages and lipids deposition and inflammatory cytokines production, improved glucose intolerance and plasma cholesterol level, the decreased ratio of matrix matalloproteinase-2/tissue inhibitor of metalloproteinase-1 and plaque instability index. An increased expression of MIF and its ligand CD74 was also detected in the diabetic patients with coronary artery disease. The results suggest that MIF gene interference is able to inhibit atherosclerotic lesions and increase plaque stability in diabetic apoE−/−mice. MIF inhibition could be a novel and promising approach to the treatment of DM-associated AS.

A score including ADAM17 substrates correlates to recurring cardiovascular event in subjects with atherosclerosis

OBJECTIVE

Atherosclerosis disease is a leading cause for mortality and morbidity. The narrowing/rupture of a vulnerable atherosclerotic plaque is accountable for acute cardiovascular events. However, despite of an intensive research, a reliable clinical method which may disclose a vulnerable patient is still unavailable.

APPROACH AND RESULTS

We tested the association of ADAM17 (A Disintegrin and Metallo Protease Domain 17) circulating substrates (sICAM-1, sVCAM-1, sIL6R and sTNFR1) with a second major cardiovascular events [MACEs] (cardiovascular death, peripheral artery surgeries, non-fatal myocardial infarction and non-fatal stroke) in 298 patients belonging to the Vascular Diabetes (AVD) study. To evaluate ADAM17 activity we create ADAM17 score through a RECPAM model. Finally we tested the discrimination ability and the reclassification of clinical models. At follow-up (mean 47 months, range 1-118 months), 55 MACEs occurred (14 nonfatal MI, 14 nonfatal strokes, 17 peripheral artery procedures and 10 cardiovascular deaths) (incidence = 7.8% person-years). An increased risk for incident events was observed among the high ADAM17 score individuals both in univariable (HR 19.20, 95% CI 15.82-63.36, p < 0.001) and multivariable analysis (HR 3.42, 95% CI 1.55-7.54, p < 0.001). Finally we found that ADAM17 score significantly increases the prediction accuracy of the Framingham Recurring-Coronary-Heart-Disease-Score, with a significant improvement in discrimination (integrated discrimination improvement = 9%, p = 0.012) and correctly reclassifying 10% of events and 41% of non-events resulting in a cNRI = 0.51 (p = 0.005).

CONCLUSION

We demonstrated a positive role of ADAM17 activity to predicting CV events. We think that an approach that targets strategies beyond classic cardiovascular risk factors control is necessary in individuals with an established vascular atherosclerosis.

Metalloproteinases promote plaque rupture and myocardial infarction: A persuasive concept waiting for clinical translation

Atherosclerotic plaque rupture provokes most myocardial infarctions. Matrix metalloproteinases (MMPs) have counteracting roles in intimal thickening, which stabilizes plaques, on the one hand and extracellular matrix destruction that leads to plaque rupture on the other. This review briefly summarizes the key points supporting the involvement of individual MMPs in provoking plaque rupture and discusses the barriers that stand in the way of clinical translation, which can be itemised as follows: structural and functional complexity of the MMP family; lack of adequate preclinical models partly owing to different expression patterns of MMPs and TIMPs in mouse and human macrophages; the need to target individual MMPs selectively; the difficulties in establishing causality in human studies; and the requirement for surrogate markers of efficacy. Overcoming these barriers would open the way to new treatments that could have a major impact on cardiovascular mortality worldwide.

Glucagon-like peptide 1 protects INS-1E mitochondria against palmitate-mediated beta-cell dysfunction: a proteomic study

Proteomic analysis of the protein expression profiles of enriched mitochondrial preparations of rat INS-1E β cells treated with palmitate in the presence and in the absence of GLP-1.