Low molecular weight heparin treatment decreases MMP-9 plasma activity in patients with abdominal aortic aneurysm

Common molecular mechanism and immune infiltration patterns of thoracic and abdominal aortic aneurysms

BACKGROUND

Aortic disease (aortic aneurysm (AA), dissection (AD)) is a serious threat to patient lives. Little is currently known about the molecular mechanisms and immune infiltration patterns underlying the development and progression of thoracic and abdominal aortic aneurysms (TAA and AAA), warranting further research.

METHODS

We downloaded AA (includes TAA and AAA) datasets from the GEO database. The potential biomarkers in TAA and AAA were identified using differential expression analysis and two machine-learning algorithms. The discrimination power of the potential biomarkers and their diagnostic accuracy was assessed in validation datasets using ROC curve analysis. Then, GSEA, KEGG, GO and DO analyses were conducted. Furthermore, two immuno-infiltration analysis algorithms were utilized to analyze the common immune infiltration patterns in TAA and AAA. Finally, a retrospective clinical study was performed on 78 patients with AD, and the serum from 6 patients was used for whole exome sequencing (WES).

RESULTS

The intersection of TAA and AAA datasets yielded 82 differentially expressed genes (DEGs). Subsequently, the biomarkers (CX3CR1 and HBB) were acquired by screening using two machine-learning algorithms and ROC curve analysis. The functional analysis of DEGs showed significant enrichment in inflammation and regulation of angiogenic pathways. Immune cell infiltration analysis revealed that adaptive and innate immune responses were closely linked to AA progression. However, neither CX3CR1 nor HBB was associated with B cell-mediated humoral immunity. CX3CR1 expression was correlated with macrophages and HBB with eosinophils. Finally, our retrospective clinical study revealed a hyperinflammatory environment in aortic disease. The WES study identified disease biomarkers and gene variants, some of which may be druggable.

CONCLUSION

The genes CX3CR1 and HBB can be used as common biomarkers in TAA and AAA. Large numbers of innate and adaptive immune cells are infiltrated in AA and are closely linked to the development and progression of AA. Moreover, CX3CR1 and HBB are highly correlated with the infiltration of immune cells and may be potential targets of immunotherapeutic drugs. Gene mutation research is a promising direction for the treatment of aortic disease.

Ageing- and AAA-associated differentially expressed proteins identified by proteomic analysis in mice

Background

Abdominal aortic aneurysm (AAA) is a disease of high prevalence in old age, and its incidence gradually increases with increasing age. There were few studies about differences in the circulatory system in the incidence of AAA, mainly because younger patients with AAA are fewer and more comorbid nonatherosclerotic factors.

Method

We induced AAA in ApoE^-/- male mice of different ages (10 or 24 weeks) and obtained plasma samples. After the top 14 most abundant proteins were detected, the plasma was analyzed by a proteomic study using the data-dependent acquisition (DDA) technique. The proteomic results were compared between different groups to identify age-related differentially expressed proteins (DEPs) in the circulation that contribute to AAA formation. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analyses were performed by R software. The top 10 proteins were determined with the MCC method of Cytoscape, and transcription factor (TF) prediction of the DEPs was performed with iRegulon (Cytoscape).

Results

The aortic diameter fold increase was higher in the aged group than in the youth group (p < 0.01). Overall, 92 DEPs related to age and involved in AAA formation were identified. GO analysis of the DEPs showed enrichment of the terms wounding healing, response to oxidative stress, regulation of body fluid levels, ribose phosphate metabolic process, and blood coagulation. The KEGG pathway analysis showed enrichment of the terms platelet activation, complement and coagulation cascades, glycolysis/gluconeogenesis, carbon metabolism, biosynthesis of amino acids, and ECM-receptor interaction. The top 10 proteins were Tpi1, Eno1, Prdx1, Ppia, Prdx6, Vwf, Prdx2, Fga, Fgg, and Fgb, and the predicted TFs of these proteins were Nfe2, Srf, Epas1, Tbp, and Hoxc8.

Conclusion

The identified proteins related to age and involved in AAA formation were associated with the response to oxidative stress, coagulation and platelet activation, and complement and inflammation pathways, and the TFs of these proteins might be potential targets for AAA treatments. Further experimental and biological studies are needed to elucidate the role of these age-associated and AAA-related proteins in the progression of AAA.

Cellular and Molecular Effects of High-Molecular-Weight Heparin on Matrix Metalloproteinase 9 Expression

Blood sampling with different anticoagulants alters matrix metalloproteinase (MMP-) 9 expression, thus influencing its concentration and diagnostic validity. Here, we aimed to evaluate the effects of different anticoagulants on MMP-9 regulation. MMP-9 expression was assessed in response to ethylenediaminetetraacetic acid, citrate, and high-/low-molecular-weight heparin (HMWH, LMWH) in co-culture experiments using THP-1, Jurkat, and HT cells (representing monocytes, T, and B cells). Triple and double cell line co-culture experiments revealed that HMWH treatment of THP-1 and Jurkat led to a significant MMP-9 induction, whereas other anticoagulants and cell type combinations had no effect. Supernatant of HMWH-treated Jurkat cells also induced MMP-9 in THP-1 suggesting monocytes as MMP-9 producers. HMWH-induced cytokine/chemokine secretion was assessed in co-culture supernatant, and the influence of cytokines/chemokines on MMP-9 production was analyzed. These experiments revealed that Jurkat-derived IL-16 and soluble intercellular adhesion molecule (sICAM-) 1 are able to induce MMP-9 and IL-8 production by THP-1. As a consequence, the increased MMP-9 expression found in HMWH blood samples may be influenced by HMWH-dependent secretion of IL-16 and sICAM-1 by T cells resulting in an increased production of MMP-9 and IL-8 by monocytes. IL-8, in turn, may support MMP-9 and its own expression in a positive autocrine feedback loop.

Antithrombotic therapy in abdominal aortic aneurysm: beneficial or detrimental?

Abdominal aortic aneurysm (AAA) is a degenerative vascular pathology resulting in significant morbidity and mortality in older adults due to rupture and sudden death. Despite 150 000 new cases and nearly 15 000 deaths annually, the only approved treatment of AAA is surgical or endovascular intervention when the risk for aortic rupture is increased. The goal of the scientific community is to develop novel pharmaceutical treatment strategies to reduce the need for surgical intervention. Because most clinically relevant AAAs contain a complex structure of fibrin, inflammatory cells, platelets, and red blood cells in the aneurysmal sac known as an intraluminal thrombus (ILT), antithrombotic therapies have emerged as potential pharmaceutical agents for the treatment of AAA progression. However, the efficacy of these treatments has not been shown, and the effects of shrinking the ILT may be as detrimental as they are beneficial. This review discusses the prospect of anticoagulant and antiplatelet (termed collectively as antithrombotic) therapies in AAA. Herein, we discuss the role of the coagulation cascade and platelet activation in human and animal models of AAA, the composition of ILT in AAA, a possible role of the ILT in aneurysm stabilization, and the implications of antithrombotic drugs in AAA treatment.

Does the dysregulation of matrix metalloproteinases contribute to recurrent implantation failure?

INTRODUCTION

The progress in in vitro fertilization (IVF) techniques for infertility management has led to the investigation of embryo implantation site proteins such as Matrix metalloproteinases (MMPs), which may have a key role in embryo-endometrium crosstalk and in the molecular mechanisms of the embryo implantation. Areas covered: Numerous studies have generated much information concerning the relation between the different proteins at the site of implantation such as cytokines, growth factors, adhesion molecules and MMPs. However, the exact role of the MMPs in embryo implantation and the impact of their dysregulation in recurrent implantation failure have yet to be characterized. Expert commentary: The proteomic investigation of the MMPs and their molecular pathways may enable scientists and clinicians to correct this dysregulation (via appropriate means of prevention and treatment), better manage embryo transfer during IVF cycles, and thus increase the ongoing pregnancy rate.

Systemic administration of heparin ameliorates radiation-induced oral mucositis-preclinical studies in mice

Purpose

The present study investigates the impact of systemic application of heparins on the manifestation of radiation-induced oral mucositis in a well-established mouse model.

Materials and methods

Male C3H/Neu mice were irradiated with either single-dose or fractionated irradiation protocols with 5 × 3 Gy/week, given over one (days 0–4) or two (days 0–4, 7–11) weeks. All fractionation protocols were concluded by a local test irradiation (day 7/14) using graded doses to generate complete dose–effect curves. Daily doses of unfractionated or low molecular weight heparin (40 or 200 I.U./mouse, respectively) were applied subcutaneously over varying time intervals. The incidence and the time course of mucosal ulceration, corresponding to confluent mucositis in patients (RTOG/EORTC grade 3), were analysed as clinically relevant endpoints.

Results

Systemic application of heparins significantly increased the iso-effective doses for the induction of mucosal ulceration, particularly in combination with fractionated irradiation protocols. Moreover, a tentative prolongation of the latent time and a pronounced reduction of the ulcer duration were observed.

Conclusion

These data provide the first evidence for a protective and/or mitigative effect of heparins for radiation-induced oral mucositis. Further studies are ongoing investigating the underlying mechanism.

Electronic supplementary material

The online version of this article (10.1007/s00066-018-1300-8) contains supplementary material, which is available to authorized users.

Intravenous heparin during ruptured abdominal aortic aneurysmal repair

BACKGROUND

There have been enormous advances in the screening, diagnosis, intervention and overall prognosis of abdominal aortic aneurysms (AAAs) in the last decade, but despite these, ruptured AAAs (rAAAs) still cause around 3500 to 6000 deaths in England and Wales each year. Open repair remains standard treatment for rAAA in most centres but increasingly endovascular aneurysm repair (EVAR) is being adopted. This has a 30-day postoperative mortality of 40%. This has remained static despite surgical, anaesthetic and critical care advances.One significant change to current practice for elective repairs of AAAs, as opposed to emergency repairs of rAAAs, has been the introduction of intravenous heparin. This provides a protective effect against cardiac and thrombotic disease in the postoperative period. This practice has not gained widespread acceptance for emergency repairs of rAAA even though a reduction in mortality and morbidity has been demonstrated in elective repairs.

OBJECTIVES

The primary objective was to assess the effect of intravenous heparin on all-cause mortality in ruptured abdominal aortic aneurysm (rAAA) management in people undergoing an emergency repair.The secondary objectives were to assess the effect of intravenous heparin in rAAA management on the incidence of general arterial disease, for example, cardiovascular, cerebral, pulmonary and renal pathologies, in people undergoing emergency repair.

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (December 2015). In addition the CIS searched CENTRAL;2015, Issue 11). The CIS searched clinical trials registries for details of ongoing or unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of intravenous heparin in rAAA repairs (including parallel designs).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no RCTs or CCTs that satisfied the inclusion criteria.

AUTHORS' CONCLUSIONS

We identified no RCTs or CCTs of intravenous heparin in rAAA repairs (including parallel designs). Therefore, we were unable to assess the effect of intravenous heparin on all-cause mortality and incidence of general arterial disease, for example, cardiovascular, cerebral, pulmonary and renal pathologies in rAAA management in people undergoing an emergency repair. It is clear that an RCT is needed to address this question in rAAA management as there is no high quality evidence.

Decreases in plasma MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios in uremic patients during hemodialysis

BACKGROUND

Matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors (TIMPs) play important roles in the pathophysiology of renal diseases. Imbalanced MMPs/TIMPs are implicated in the vascular alterations of uremic patients on hemodialysis (HD). We have investigated the plasma levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in uremic patients and the effects of a course of HD on the changes in these factors.

METHODS

There were 382 uremic patients on regular HD treatment and 50 healthy controls enrolled in this study. The plasma MMP-2 and MMP-9 levels were detected by gelatin zymography, and TIMP-1 and TIMP-2 concentrations were determined by ELISA assay.

RESULTS

Significantly higher plasma MMP-2 and MMP-9 and decreased TIMP-1 in the uremic patients were detected compared with those in the controls. Therefore, there were markedly higher MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios in the uremic patients. In the course of a single HD session, the plasma MMP-2 level was significantly decreased from pre-HD to post-HD. TIMP-1 concentration was significantly increased from pre-HD to post-HD. Although the HD session did not have a significant effect on the levels of plasma MMP-9 and TIMP-2, both plasma MMP-2/TIMP-2 and MMP-9/TIMP-1 ratios were significantly decreased from pre-HD to post-HD levels.

CONCLUSION

HD session could decrease MMP-2 and increase TIMP-1 level in the circulation of uremic patients. The physiological significance of reduced MMPs/TIMPs ratio due to a single HD session is required to further validate.

Prolonged Treatment with Inhaled Corticosteroids does not Normalize High Activity of Matrix Metalloproteinase-9 in Exhaled Breath Condensates of Children with Asthma

The airway remodeling in asthma is associated with increased amount of matrix metalloproteinase (MMP)-9. High levels of MMP-9 were found in mucosal biopsies, sputum and in exhaled breath condensates (EBC) of asthma patients. However, there are no data concerning real in vivo activity. Inhaled corticosteroids are effective in asthma control, but it is unclear, whether they only attenuate inflammation, or also protect against progressive remodeling of respiratory tract. Therefore, the aim of the study was to assess the amount and activity of MMP-9 in context of pro-inflammatory cytokines (IL-6, IL-8 and tumor necrosis factor, TNF), measured in EBC of asthma-suffering children, treated with inhaled steroids. The study involved 27 children with asthma, continuously treated with inhaled fluticasone propionate, and 22 healthy controls. In addition to routine clinical screening, the selected cytokines in EBC were analyzed using Ultrasensitive ELISA, whereas activity of MMP-9 was assessed using a novel immunozymography method. Despite chronic treatment with inhaled steroids mean MMP-9/EBC activity in asthma group was significantly higher than in healthy controls. Moreover, high MMP-9/EBC in asthma-suffering children significantly correlated with IgE serum levels. The IL-6 and IL-8 concentration was below the detection limit in all EBC samples. TNF/EBC levels were similar in both, asthma and healthy children. We hypothesize that MMP-9 hyperactivity in asthma may be closely related to high IgE serum levels. Our results suggest that inhaled steroids may be ineffective to prevent asthma-associated airway remodeling. Finally, we emphasize the necessity of further research focused on MMP-9 inhibition in asthma treatment.

Matrix metalloproteinases and peripheral arterial disease

Matrix metalloproteinases (MMPs), a family of enzymes that degrade extracellular matrix, are emerging as important modulators of atherothrombosis. MMPs are produced by inflammatory cells; some of them are also released by activated platelets and play a crucial role in the remodeling processes, leading to atherosclerotic plaque formation, plaque rupture, arterial aneurysm development, and critical limb ischemia. Independent from their matrix degrading activity, MMPs also regulate some cell functions relevant to atherothrombosis, such as platelet activation, neutrophil activation, and vascular reactivity. Plasma levels of some MMPs are increasingly being recognized as a biomarker of atherosclerosis and cardiovascular risk. In peripheral arterial disease, MMPs have been shown to be involved in angiogenesis, arteriogenesis, and the development of arterial calcifications. Increased plasma levels of some MMPs (MMP-2, MMP-9) have been correlated with PAD development and severity. Single nucleotide polymorphisms of the genes encoding for some MMPs have also been associated with the risk of developing peripheral arterial disease and critical limb ischemia. Large prospective observational studies are needed to further demonstrate the role of MMPs in PAD. In perspective, pharmacologic targeting of the expression or activity of MMPs may represent a novel, attractive approach for the treatment of peripheral arterial disease.