Serum levels of matrix metalloproteinases -1,-2,-3 and -9 in thoracic aortic diseases and acute myocardial ischemia

REDV-Functionalized Recombinant Spider Silk for Next-Generation Coronary Artery Stent Coatings: Hemocompatible, Drug-Eluting, and Endothelial Cell-Specific Materials

Coronary artery stents are life-saving devices, and millions of these devices are implanted annually to treat coronary heart disease. The current gold standard in treatment is drug-eluting stents, which are coated with a biodegradable polymer layer that elutes antiproliferative drugs to prevent restenosis due to neointimal hyperplasia. Stenting is commonly paired with systemic antiplatelet therapy to prevent stent thrombosis. Despite their clinical success, current stents have significant limitations including inducing local inflammation that drives hyperplasia; a lack of hemocompatibility that promotes thrombosis, increasing need for antiplatelet therapy; and limited endothelialization, which is a critical step in the healing process. In this research, we designed a novel material for use as a next-generation coating for drug-eluting stents that addresses the limitations described above. Specifically, we developed a recombinant spider silk material that is functionalized with an REDV cell-adhesive ligand, a peptide motif that promotes specific adhesion of endothelial cells in the cardiovascular environment. We illustrated that this REDV-modified spider silk variant [eADF4(C16)-REDV] is an endothelial-cell-specific material that can promote the formation of a near-confluent endothelium. We additionally performed hemocompatibility assays using human whole blood and demonstrated that spider silk materials exhibit excellent hemocompatibility under both static and flow conditions. Furthermore, we showed that the material displayed slow enzyme-mediated degradation. Finally, we illustrated the ability to load and release the clinically relevant drug everolimus from recombinant spider silk coatings in a quantity and at a rate similar to that of commercial devices. These results support the use of REDV-functionalized recombinant spider silk as a coating for drug-eluting stents.

Nanotechnology Applications in Breast Cancer Immunotherapy

Next-generation cancer treatments are expected not only to target cancer cells but also to simultaneously train immune cells to combat cancer while modulating the immune-suppressive environment of tumors and hosts to ensure a robust and lasting response. Achieving this requires carriers that can codeliver multiple therapeutics to the right cancer and/or immune cells while ensuring patient safety. Nanotechnology holds great potential for addressing these challenges. This article highlights the recent advances in nanoimmunotherapeutic development, with a focus on breast cancer. While immune checkpoint inhibitors (ICIs) have achieved remarkable success and lead to cures in some cancers, their response rate in breast cancer is low. The poor response rate in solid tumors is often associated with the low infiltration of anti-cancer T cells and an immunosuppressive tumor microenvironment (TME). To enhance anti-cancer T-cell responses, nanoparticles are employed to deliver ICIs, bispecific antibodies, cytokines, and agents that induce immunogenic cancer cell death (ICD). Additionally, nanoparticles are used to manipulate various components of the TME, such as immunosuppressive myeloid cells, macrophages, dendritic cells, and fibroblasts to improve T-cell activities. Finally, this article discusses the outlook, challenges, and future directions of nanoimmunotherapeutics.

Long-Term Effects of Pulmonary Endarterectomy on Right Ventricular Stiffness and Fibrosis in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Surgical removal of thromboembolic material by pulmonary endarterectomy (PEA) leads within months to the improvement of right ventricular (RV) function in the majority of patients with chronic thromboembolic pulmonary hypertension. However, RV mass does not always normalize. It is unknown whether incomplete reversal of RV remodeling results from extracellular matrix expansion (diffuse interstitial fibrosis) or cellular hypertrophy, and whether residual RV remodeling relates to altered diastolic function.

METHODS

We prospectively included 25 patients with chronic thromboembolic pulmonary hypertension treated with PEA. Structured follow-up measurements were performed before, and 6 and 18 months after PEA. With single beat pressure-volume loop analyses, we determined RV end-systolic elastance (Ees), arterial elastance (Ea), RV-arterial coupling (Ees/Ea), and RV end-diastolic elastance (stiffness, Eed). The extracellular volume fraction of the RV free wall was measured by cardiac magnetic resonance imaging and used to separate the myocardium into cellular and matrix volume. Circulating collagen biomarkers were analyzed to determine the contribution of collagen metabolism.

RESULTS

RV mass significantly decreased from 43±15 to 27±11g/m2 (-15.9 g/m2 [95% CI, -21.4 to -10.5]; P<0.0001) 6 months after PEA but did not normalize (28±9 versus 22±6 g/m2 in healthy controls [95% CI, 2.1 to 9.8]; P<0.01). On the contrary, Eed normalized after PEA. Extracellular volume fraction in the right ventricular free wall increased after PEA from 31.0±3.8 to 33.6±3.5% (3.6% [95% CI, 1.2-6.1]; P=0.013) as a result of a larger reduction in cellular volume than in matrix volume (Pinteraction=0.0013). Levels of MMP-1 (matrix metalloproteinase-1), TIMP-1 (tissue inhibitor of metalloproteinase-1), and TGF-β (transforming growth factor-β) were elevated at baseline and remained elevated post-PEA.

CONCLUSIONS

Although cellular hypertrophy regresses and diastolic stiffness normalizes after PEA, a relative increase in extracellular volume remains. Incomplete regression of diffuse RV interstitial fibrosis after PEA is accompanied by elevated levels of circulating collagen biomarkers, suggestive of active collagen turnover.

Artificial Intelligence Uncovers Natural MMP Inhibitor Crocin as a Potential Treatment of Thoracic Aortic Aneurysm and Dissection

Thoracic aortic aneurysm and dissection (TAAD) is a lethal cardiovascular condition without effective pharmaceutical therapy. Identifying novel drugs that target the key pathogenetic components is an urgent need. Bioinformatics analysis of pathological studies indicated “extracellular matrix organization” as the most significant functional pathway related to TAAD, in which matrix metallopeptidase (MMP) 2 and MMP9 ranked above other proteases. MMP1-14 were designated as the prototype molecules for docking against PubChem Compound Database using Surflex-Dock, and nine natural compounds were identified. Using a generic MMP activity assay and an aminopropionitrile (BAPN)-induced TAAD mouse model, we identified crocin as an effective MMP inhibitor, suppressing the occurrence and rupture of TAAD. Biolayer interferometry and AI/bioinformatics analyses indicated that crocin may inhibit MMP2 activity by direct binding. Possible binding sites were investigated. Overall, the integration of artificial intelligence and functional experiments identified crocin as an MMP inhibitor with strong therapeutic potential.

Matrix metalloproteinases and acute aortic dissection: Et Tu, Brute?

OBJECTIVES

To summarize the present evidence for the association of matrix metalloproteinases (MMPs) with acute aortic dissection (AAD), we performed the first meta-analysis of all currently available case-control studies comparing circulating MMP levels between AAD patients and control subjects.

METHODS

To identify all studies investigating the levels of circulating MMPs in AAD patients, PubMed and Web of Science were searched up to July 2019. The levels of MMPs in AAD patients and control subjects were extracted from each study, and the standardized mean differences (SMDs) in MMP levels were generated. The study-specific estimates were combined in the random-effects model.

RESULTS

Twelve studies enrolling a total of 458 AAD patients and 711 control subjects were identified and included. Pooled analyses demonstrated no significant differences in MMP-1 (4 studies; P = 0.21), MMP-2 (5 studies; P = 0.62) and MMP-3 levels (2 studies; P = 0.94) between AAD patients and control subjects; and significantly higher MMP-8 (2 studies; SMD 2.11; P = 0.020), MMP-9 (9 studies; SMD 1.54; P < 0.001) and MMP-12 levels (2 studies; SMD 1.33; P < 0.001) in AAD patients than in control subjects.

CONCLUSION

High circulating MMP-9 levels are associated with AAD, and MMP-8 and MMP-12 levels may be related to AAD.

Genetic Polymorphisms of MMP1, MMP9, COL1A1, and COL1A2 in Polish Patients with Thoracic Aortopathy

BACKGROUND

The pathogenesis of thoracic aortopathy is complex, and much evidence suggests the influence of genetic factors. Some genes with polymorphisms are widely considered critical factors in the initiation and development of aortic aneurysm. The aim of our study was to analyze the association of genetic polymorphisms of MMP1 rs1799750 (c.-1607G>GG), MMP9 rs3918242 (c.-1562C>T), COL1A1 rs1800012 (c.1245G>T), and COL1A2 rs42524 (c.1645G>C) with predisposition to thoracic aortopathy in Polish patients and with clinical characteristics of these patients.

METHODS

The study was carried out with 96 patients with thoracic aortopathy (47 patients with ascending aortic aneurysm and 49 patients with thoracic aortic dissection) and 61 control subjects without thoracic aortopathy. The MMP1, MMP9, COL1A1, and COL1A2 polymorphisms were determined by PCR-RFLP.

RESULTS

No significant differences in the frequency distributions of MMP1, MMP9, COL1A1, and COL1A2 genotypes or alleles were found (1) between the control group and patients with ascending aortic aneurysm (AsAA), (2) between the control group and patients with thoracic aortic dissection (TAD), or (3) between AsAA and TAD patients. Multivariate logistic regression analysis revealed that MMP1 and MMP9 polymorphisms were associated with the degree of aortic valve regurgitation.

CONCLUSION

The results of our study did not support associations between MMP1, MMP9, COL1A1, and COL1A2 genetic variants with the risk of thoracic artery disease in Polish patients. However, rs1799750 MMP1 and rs3918242 MMP9 seem to be associated with the degree of aortic regurgitation.

Serum matrix metalloproteinase-9 is a valuable biomarker for identification of abdominal and thoracic aortic aneurysm: a case-control study

Background

Matrix metalloproteinase-9 (MMP9) has been reported to play a key role in the pathogenesis of aortic aneurysm. However, few studies have assessed serum MMP9 levels in both abdominal aortic aneurysm (AAA) and thoracic aortic aneurysm (TAA). In this study, we investigated the serum levels of MMP9 in aortic aneurysm to evaluate its predictive and diagnostic efficacy for AAA and TAA, and explored the association of MMP9 with circulating laboratory markers.

Methods

A total of 296 subjects were enrolled, including 105 AAA patients, 79 TAA patients and 112 healthy controls. The levels of serum MMP9 were detected by enzyme-linked immunosorbent assay (ELISA).

Results

Compared to control group, both AAA and TAA patients had higher serum MMP9 levels in the overall comparison and subgroup analysis based on subjects aged<65 years, either male or female, hypertension, non-diabetes and non-hyperlipidemia (all P<0.05). Moreover, MMP9 levels were significantly higher in TAA group than those in AAA group in the total comparison, and this discrepancy was also found in the non-diabetes, non-hyperlipidemia and aortic diameter ≥ 5.5 cm subgroup analysis. Serum MMP9 levels were influenced by age and hypertension. There was a positive association of serum MMP9 with CRP (r = 0.33, P < 0.001) and Hcy (r = 0.199, P = 0.033). Multiple logistic analyses showed that serum MMP9 was an independent risk factor for AAA and TAA. Based on receiver operating characteristic (ROC) analysis, the area under the curve (AUC) of MMP9 for predicting TAA was 0.83 with 70% sensitivity and 91% specificity, while the AUC of MMP9 to detect AAA was 0.69 and the sensitivity and specificity were 50% and 88%.

Conclusions

Serum MMP9 was closely related to the existence of aortic aneurysms and could be a valuable marker for the discrimination of aortic aneurysm, especially for TAA.

Mechanical stretch aggravates aortic dissection by regulating MAPK pathway and the expression of MMP-9 and inflammation factors

This study aimed to explore whether mechanical stretch aggravated aortic dissection through regulating MAPK pathway, MMP-9, and inflammation factors. We first established aortic dissection model rats. Mechanical stretch (3 g) was exerted on vascular ring of aortic dissection which was also treated by inhibitors of MAPK pathway (SB203580, SP600125, and U0126). HE and Masson staining showed that aortic dissection severity with 3 g tension was worse than that without tension (0 g); after the treatments of diverse inhibitors, the fracture and breakage of the elastic fibers decreased. The expression of MMP-9, TNF-α, IL-1β) p38/p-p38, JNK1/p-JNK1, and ERK1/2/p-ERK1/2 were determined by immunohistochemical analysis, RT-PCR, and western blot. No matter whether tension was exerted or inhibitors were added, there was no change in the expression of p38, JNK1, and ERK1/2. However, compared to the 0 g group, the expression of MMP-9, TNF-α, IL-1β, p-p38, p-JNK1, and p-ERK1/2 was significantly upregulated in the 3 g group (P < 0.05). In both 0 g and 3 g groups, the expression of MMP-9, TNF-α, IL-1β, p-p38, p-JNK1, and p-ERK1/2 was remarkably downregulated after inhibitors treatment (P < 0.05). In conclusion, mechanical stretch aggravated aortic dissection by regulating the MAPK pathway and the consequent expression of MMP-9 and inflammation factors.

Circulating tumor cells and serum levels of MMP-2, MMP-9 and VEGF as markers of the metastatic process in patients with high risk of metastatic progression

BACKGROUND AND AIMS

Metastases are a severe complication in cancer patients and biomarkers predicting their progression are still lacking for specific groups of patients. HER2 positive breast cancer (HER2 BC) patients on trastuzumab therapy are at risk of the development of unpredictable and often fatal central nervous system (CNS) metastases and castration resistant prostate cancer (CRPC) patients urgently need a marker of disease progression during therapy. Proposed metastatic markers: circulating tumor cells (CTC), serum levels of matrix metalloproteinase 2 (MMP-2), 9 (MMP-9) and vascular endothelial growth factor (VEGF) were prospectively studied to confirm their utility in these two narrowly defined groups of cancer patients.

PATIENTS AND METHODS

The groups comprised 44 advanced HER2 BC, 24 CRPC patients and 42 healthy controls. An immunomagnetic separation method followed by PCR and electrophoretic detection (AdnaGen, Germany) were used for CTC determination. Serum marker levels were determined by the ELISAs (R&D System, USA).

RESULTS

MMP-2 serum level was significantly higher in HER2 BC patients who developed CNS metastases, especially if there were also bone metastases. CTCs were a negative predictive marker for overall survival in HER2 BC patients. MMP-9 serum level was significantly higher in CRPC patients in whom disease progression occurred. CTC vanished from the blood of most of the CRPC patients (from 88% to 37%) during chemotherapy.

CONCLUSION

MMP-2 serum level and CTCs show the potential to predict CNS metastases and overall survival in BC patients. CTCs and MMP-9 serum level could be a promising therapy response marker in CRPC patients.

Mechanical Strain Induced Expression of Matrix Metalloproteinase-9 via Stretch-Activated Channels in Rat Abdominal Aortic Dissection

Background

The aim of the study was to investigate the expression of matrix metalloproteinase-9 (MMP-9) in rat abdominal aortic dissection (AD) induced by mechanical strain, so as to offer a better understanding of the possible mechanisms of AD.

Material/Methods

Experimental AD in rats was achieved by the injection of porcine pancreatic elastase. At days 0, 1, 3, 5, 7, 14, 21, and 30 after the establishment of AD model, serum MMP-9 levels were measured by enzyme-linked immunosorbent assay (ELISA). Four groups of vascular rings were stretched in vitro with a mechanical strength of 0 g, 1 g, 3 g, or 5 g for 30 min. Another four groups were pretreated with GdCl₃, streptomycin, SN50, and SN50M, followed by stretching with 3 g for 30 min. The messenger RNA and the protein of MMP-9 were analyzed by real-time RT-PCR and Western blotting, and NF-κB p65 was detected by ELISA.

Results

After the establishment of rat abdominal AD model, the serum MMP-9 levels of AD groups increased significantly. The results showed increased expression of MMP-9 in rat AD vessels stretched with mechanical strength of 1 g, 3 g, and 5 g, but this effect was mostly blocked by Gd Cl₃ and streptomycin. The NF-κB activity in aortic rings was activated by stretching with a mechanical strength of 3 g and was blocked by SN50, but not by SN50M.

Conclusions

The expression of MMP-9 in serum was increased significantly after rat abdominal AD formation. Mechanical strain induced MMP-9 expression in AD vessels, which was mediated through the activation of the stretch-activated channel-induced NF-κB pathway.

Matrix metalloproteinases are possible targets in monocrotaline-induced pulmonary hypertension: investigation of anti-remodeling effects of alagebrium and everolimus

Objective:

In our study, sildenafil alone and everolimus or alagebrium in combination with sildenafil were investigated in terms of their additional therapeutic and anti-remodeling activity in monocrotaline-induced pulmonary hypertension (PH) model in rats. In particular, the inter-relationships between PH and matrix metalloproteinases (MMPs) were investigated.

Methods:

The pulmonary artery responses of male Sprague Dawley rats were recorded using myography, and the quantities and activities of MMPs were analyzed in homogenates of the pulmonary arteries and lungs by enzyme-linked immunosorbent assays, activity assays, and gelatin zymography techniques.

Results:

Our results indicated that the therapeutic effects of sildenafil were accompanied by its suppressor effects on MMP activity. It was also shown that everolimus or alagebrium in combination with sildenafil showed additional regulatory effects on MMPs as well as functional responses on pulmonary artery pressure. Therefore, the enzymes in the MMP superfamily are likely to be target molecules for the treatment of PH.

Conclusion:

In conclusion, MMPs were involved in the pathogenesis of PH, and our results suggested that the addition of everolimus or alagebrium to sildenafil therapy may be beneficial in PH. Our results indicated that agents that limit pulmonary vascular hypertrophy and inflammation via their anti-remodeling effects significantly ameliorate mortality and morbidity in PH.

Advanced Glycation End Products and its Soluble Receptors in the Pathogenesis of Thoracic Aortic Aneurysm

BACKGROUND

Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of thoracic aortic aneurysms (TAAs). Cytokines [Interleukin (IL)-Iβ, IL-2, IL-6, and TNF-α)] increase the expression of MMP-2 and -3. Advanced glycation end products (AGEs) interact with cell receptors to increase the release of cytokines. Circulating soluble receptors for AGEs (sRAGE) and endogenous secretory RAGE (esRAGE) compete with membrane bound RAGE for binding with AGEs and reduce the production of cytokines. It is hypothesized that low levels of serum sRAGE and esRAGE and high levels of AGEs, AGEs/sRAGE, and AGEs/esRAGE would increase the levels of cytokines that would increase the levels MMPs, thus contributing to the formation of TAAs.

METHODS

The study population was composed of 17 control subjects and 20 patients with TAA. Blood samples were collected for measurement of serum sRAGE, esRAGE, AGEs, cytokines, and MMPs. AGEs, sRAGE, and esRAGE were measured using ELISA kits, whereas the remaining parameters were measured using the Luminex Multi-Analyte system.

RESULTS

The levels of sRAGE were lower, while the levels of AGEs, AGEs/sRAGE, AGEs/esRAGE, cytokines and MMPs were higher in patients with TAA compared to controls. The levels of sRAGE were inversely correlated with cytokines and MMPs, while AGEs, AGEs/sRAGE and AGEs/esRAGE were positively correlated with cytokines and MMPs. Cytokines were positively correlated with MMPs.

CONCLUSIONS

The data suggest that the AGE-RAGE axis may be involved in the pathogenesis of TAA and that low levels of sRAGE and high levels of AGEs, AGEs/sRAGE, and AGEs/esRAGE are risk factors for TAA.

Stanford-A acute aortic dissection, inflammation, and metalloproteinases: a review

Acute aortic dissection (AAD) is a life-threatening disease with an incidence of about 2.6-3.6 cases per 100,000/year. Depending on the site of rupture, AAD is classified as Stanford-A when the ascending aortic thoracic tract and/or the arch are involved, and Stanford-B when the descending thoracic aorta and/or aortic abdominal tract are targeted. It was recently shown that inflammatory pathways underlie aortic rupture in both type A and type B Stanford AAD. An immune infiltrate has been found within the middle and outer tunics of dissected aortic specimens. It has also been observed that the recall and activation of macrophages inside the middle tunic are key events in the early phases of AAD. Macrophages are able to release metalloproteinases (MMPs) and pro-inflammatory cytokines which, in turn, give rise to matrix degradation and neoangiogenesis. An imbalance between the production of MMPs and MMP tissue inhibitors is pivotal in the extracellular matrix degradation underlying aortic wall remodelling in dissections occurring both in inherited conditions and in atherosclerosis. Among MMPs, MMP-12 is considered a specific marker of aortic wall disease, whatever the genetic predisposition may be. The aim of this review is, therefore, to take a close look at the immune-inflammatory mechanisms underlying Stanford-A AAD.

Biomarkers for the diagnosis of aortic dissection

This review discusses the role of biomarkers for both diagnoses and disease monitoring before, during, and after treatment of aortic dissection.

Simple assay for proteases based on aggregation of stimulus-responsive polypeptides

Unregulated changes in protease activity are linked to many diseases including cancer. Fast, accurate, and low-cost assays for detection of these changes are being explored for early diagnosis and monitoring of these diseases and can also be used as platforms for the discovery of new drugs. We report a new methodology for the simple detection and quantification of protease activity in buffer and human serum. The assay is based on recombinant diblock polypeptides that undergo temperature- or salt-triggered micellization in water. The coronae of the micelles are linked to the water-insoluble cores by a peptide substrate that is cleaved in the presence of the target protease. Protease cleavage of the diblock polypeptide triggers the aggregation of the core-forming segment, leading to a change in solution optical density, which can be used to detect the presence of, and to quantify the concentration of, protease. We used matrix metalloproteinase-1 (MMP-1) as a model protease and found peptide aggregation time to be proportional to enzyme concentration over a range from endogenous MMP-1 level in human serum (∼3 ng/mL) to 100 ng/mL (0.15-5 nM) in 40% human serum and 1-100 ng/mL in buffer. The assay does not require any intermediate steps or sophisticated data analysis, and the modular design of the assay system is amenable to straightforward adaptation for the detection of a wide range of proteases.

Matrix metalloproteinase levels in chronic thoracic aortic dissection

BACKGROUND

Imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) can lead to aortic wall failure. We hypothesized that patients with aneurysms resulting from chronic descending thoracic aortic dissection have elevated tissue and plasma levels of specific MMPs and decreased tissue levels of TIMPs.

MATERIALS AND METHODS

Aortic tissue was obtained from 25 patients who required surgical repair of descending thoracic aortic aneurysm due to chronic aortic dissection and from 17 organ-donor controls without aortic disease. Tissue levels of MMP-1, -2, -3, -9, -12, and -13 and TIMP-1 and -2 were measured by colorimetric activity assay or enzyme-linked immunosorbent assay and confirmed by Western blot and immunohistochemistry. Blood obtained from the 25 patients and 15 controls without aortic diseases was used to compare plasma levels of MMP-3, -9, and -12.

RESULTS

Total MMP-1, total MMP-9, and active MMP-9 levels were higher and total MMP-2 levels were lower in dissection tissue than in control tissue. Additionally, the MMP-9 to TIMP-1 and active to total MMP-2 ratios were higher and the MMP-2 to TIMP-2 ratio was lower in dissection tissue. Furthermore, patients had higher plasma active to total MMP-9 ratios than the controls. Age and hypertension were associated with increased MMP levels.

CONCLUSIONS

Increased levels of several MMPs and increased MMP to TIMP ratios in aortic tissue from patients suggest an environment that favors proteolysis, which may promote progressive extracellular matrix destruction and medial degeneration after aortic dissection. An elevated active to total MMP-9 ratio in plasma may be a biomarker for end-stage aneurysm development in patients with chronic thoracic aortic disease.

Finite element modeling of a novel self-expanding endovascular stent method in treatment of aortic aneurysms

A novel large self-expanding endovascular stent was designed with strut thickness of 70 μm × 70 μm width. The method was developed and investigated to identify a novel simpler technique in aortic aneurysm therapy. Stage 1 analysis was performed after deploying it in a virtual aneurysm model of 6 cm wide × 6 cm long fusiform hyper-elastic anisotropic design. At cell width of 9 mm, there was no buckling or migration of the stent at 180 Hg. Radial force of the stents was estimated after parametric variations. In stage 2 analysis, a prototype 300 μm × 150 μm stent with a cell width of 9 mm was chosen, and it was evaluated similarly after embedding in the aortic wall, and also with a tissue overgrowth of 1 mm over the stent. The 300/150 μm stent reduced the peak wall stress by 70% in the aneurysm and 50% reduction in compliance after embedding. Stage 3 analysis was performed to study the efficacy of stents with struts (thickness/width) 70/70, 180/100 and 300/150 μm after embedding and tissue overgrowth. The adjacent wall stresses were very minimal in stents with 180/100 and 70/70 μm struts after embedding. There is potential for a novel stent method in aortic aneurysm therapy.

Impact of matrix metalloproteinase-8 gene variations on the risk of thoracic aortic dissection in a Chinese Han population

The importance of matrix metalloproteinase 8 (MMP8) expression during the progression of thoracic aortic dissection (TAD) has been recently emphasized. Genetic variations that affect proteinase expression or activity might contribute to the pathogenesis of TAD. In this study, we investigated whether the MMP8 C-799T genotype is associated with TAD. The frequency distributions of the MMP8 C-799T polymorphism were determined by direct sequencing. Associations between the polymorphism and disease progression in TAD were investigated. The level of plasma and tissue MMP8 was measured by enzyme-linked immunosorbent assay and western blotting. The MMP8 C-799T polymorphism was significantly associated with susceptibility to disease progression in TAD patients (n = 152) than in controls (n = 147) (P = 0.004, OR = 0.62, 95 % CI 0.45–0.86). The TT homozygotes had a significantly higher risk of TAD compared to C allele carriers in a logistic regression model, after adjustment for the conventional risk factors for TAD. The plasma MMP8 concentration was significantly higher in TAD patients compared to control patients (P < 0.05). TT genotypes had increased MMP8 levels compared to CC and CT genotype carriers in both TAD and control subjects (P < 0.05). The C-799T polymorphism in the MMP8 promoter is part of the genetic variation underlying the susceptibility of individuals to the progression of TAD.

Thoracic aortic aneurysm frequency and dissection are associated with fibrillin-1 fragment concentrations in circulation

RATIONALE

Mutations in fibrillin-1 are associated with thoracic aortic aneurysm (TAA) in Marfan syndrome. Genome-wide association studies also implicate fibrillin-1 in sporadic TAA. Fragmentation of the aortic elastic lamellae is characteristic of TAA.

OBJECTIVE

Immunoassays were generated to test whether circulating fragments of fibrillin-1, or other microfibril fragments, are associated with TAA and dissection.

METHODS AND RESULTS

Plasma samples were obtained from 1265 patients with aortic aneurysm or dissection and from 125 control subjects. Concentrations of fibrillin-1, fibrillin-2, and fibulin-4 were measured with novel immunoassays. One hundred and seventy-four patients (13%) had aneurysms with only abdominal aortic involvement (abdominal aortic aneurysm), and 1091 (86%) had TAA. Of those with TAA, 300 patients (27%) had chronic dissection and 109 (10%) had acute or subacute dissection. Associations of fragment concentrations with TAA (versus abdominal aortic aneurysm) or with dissection (versus no dissection) were estimated with odds ratios (OR) and 95% confidence intervals (CI) adjusted for age, sex, and smoking. Compared with controls, significantly higher percentages of aneurysm patients had detectable levels of fibrillin fragments. TAA was significantly more common (than abdominal aortic aneurysm) in the highest compared with lowest quartile of fibrillin-1 concentration (OR=2.9; 95% CI, 1.6-5.0). Relative to TAA without dissection, acute or subacute dissection (OR=2.9; 95% CI, 1.6-5.3), but not chronic dissection, was more frequent in the highest compared with lowest quartile of fibrillin-1 concentration. Neither TAA nor dissection was associated with fibrillin-2 or fibulin-4.

CONCLUSIONS

Circulating fibrillin-1 fragments represent a new potential biomarker for TAA and acute aortic dissection.

Biological features of thoracic aortic diseases. Where are we now, where are we heading to: established and emerging biomarkers and molecular pathways

Thoracic aortic aneurysms (TAAs) and aortic dissections (ADs) are among the main causes of mortality and morbidity in Western countries. For this reason, the diagnosis, prevention and prediction of TAAs and ADs have become a very active area of research; in fact, it is important to monitor and predict the evolution of these diseases over time. It is also critical, in cases of doubtful diagnosis, to receive some guidance from biochemical assays, particularly in the case of ADs. Although biological testing for disease prediction has already been discussed several times, the role of biomarkers in TAAs and ADs is still under discussion for routine patient screening, periodical follow-up or for prompt diagnosis in emergency conditions. In this review, we update the current knowledge and new trends regarding the role of biomarkers in thoracic aortic diseases, focusing on established and emerging biomarkers in the fields of genetics, inflammation, haemostasis and matrix remodelling as well as on substances released upon cell damage. Other than D-dimer, a sensitive but not a specific marker for the diagnosis of AD that has been widely tested by several authors and currently seems a viable option in ambiguous cases, the remaining markers have been most frequently assessed in limited or mixed patient populations. This currently precludes their widespread adoption as diagnostic or prognostic tools, even if many of these markers are conceptually promising. In years to come, we expect that future studies will further clarify the diagnostic and prognostic features of several established and emerging biomarkers that, to date, are still in the translational limbo separating biological discovery from a practical clinical role.

Neurological biomarkers in the perioperative period

The rapid detection and evaluation of patients presenting with perioperative neurological dysfunction is of great clinical relevance. Biomarkers have been defined as biological molecules that can be used as an indicator of new onset or progression of a biological process or effect of treatment. Biomarkers have become increasingly important in this setting to supplement other modalities of diagnosis such as EEG, sensory- or motor-evoked potential, transcranial Doppler, near-infrared spectroscopy, or imaging methods. A number of neuro-proteins have been identified and are currently under investigation for potential to provide insights into injury severity, outcome, and the ability to monitor cellular damage and molecular events that occur during neurological injury. S100B is a protein released by glial cells and is considered a marker of blood-brain barrier dysfunction. Clinical studies in patients undergoing cardiac and non-cardiac surgery indicate that serum levels of S100B are increased intraoperatively and after operation. The neurone-specific enolase has also been extensively investigated as a potential marker of neuronal injury in the context of cardiac and non-cardiac surgery. A third biomarker of interest is the Tau protein, which has been linked to neurodegenerative disorders. Tau appears to be more specific than the previous two biomarkers since it is only found in the central nervous system. The metalloproteinase and ubiquitin C terminal hydroxylase-L1 (UCH-L1) are the most recently researched markers; however, their usefulness is still unclear. This review presents a comprehensive overview of S100B, neuronal-specific enolase, metalloproteinases, and UCH-L1 in the perioperative period.

Plasma concentrations of interleukin-6, C-reactive protein, tumor necrosis factor-α and matrix metalloproteinase-9 in aortic dissection

BACKGROUND

The role of inflammation in aortic dissection (AD) has not fully been investigated. We evaluated the potential relationships between interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase-9 (MMP-9) and AD.

METHODS

Plasma concentrations of IL-6, TNF-α, MMP-9 and CRP were determined in 64 acute AD patients, 42 patients with chronic AD, 98 patients with hypertension alone, and 96 healthy subjects.

RESULTS

IL-6 concentrations were higher in acute AD than that in hypertension and healthy controls (10.98±2.38 vs. 3.79±1.56 and 3.32±1.60 pg/ml, P<0.05, respectively). Increased CRP concentrations were found in acute AD compared with chronic AD and hypertension as well as healthy subjects (13.48±3.74 vs. 4.12±2.99, 1.62±0.65 and 1.12±0.35 mg/l, P<0.001, respectively). Higher MMP-9 concentrations were detected in acute AD, chronic AD and hypertension compared with healthy controls (37.75±9.38, 55.78±6.41 and 31.03±7.94 vs. 21.24±7.28 ng/ml, P<0.05, P<0.001 and P<0.05, respectively), and in the dead compared to the survived (107.29±9.38 vs. 86.80±7.93 ng/ml, P<0.001) among acute AD patients. In acute AD, the time after onset had positive correlation with TNF-α (r=0.497, P=0.000), and negative correlation with CRP (r=-0.424, P=0.000). Plasma CRP levels decreased significantly when the onset time increased (P=0.013). Moreover, in the patients with acute AD who underwent surgery and stenting, plasma MMP-9 concentrations increased immediately after surgical treatment and stenting, and reached the peak values at 24h, then decreased at 1 week (P<0.001).

CONCLUSIONS

Our findings confirmed and extended previous studies that increased plasma inflammatory markers were significantly associated with AD.

Levels of matrix metalloproteinase-1 and tissue inhibitors of metalloproteinase-1 in gastric cancer

AIM: To evaluate the levels of preoperative serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in gastric cancer.

METHODS: One hundred gastric cancer patients who underwent gastrectomy were enrolled in this study. The serum concentrations of MMP-1 and TIMP-1 in these patients and in fifty healthy controls were determined using an enzyme-linked immunosorbent assay.

RESULTS: Higher serum MMP-1 and TIMP-1 levels were observed in patients than in controls (P < 0.001). Serum MMP-1 and TIMP-1 levels were positively associated with morphological appearance, tumor size, depth of wall invasion, lymph node metastasis, liver metastasis, perineural invasion, and pathological stage. They were not significantly associated with age, gender, tumor location, or histological type.

CONCLUSION: Increased MMP-1 and TIMP-1 were associated with gastric cancer. Although these markers are not good markers for diagnosis, these markers show in advanced gastric cancer.

Differential expression of elastin assembly genes in patients with Stanford Type A aortic dissection using microarray analysis

OBJECTIVE

Pathologic studies have demonstrated that aortic dissection is initiated by an intimal tear, followed by the rapid growth of an intramural hematoma that dissects the media and is characterized by elastin degradation. Genetic extracellular matrix abnormalities and proteinases may be the predisposing factors in aortic dissection, but little is known about the role of elastic fiber assembly. Fibulin-1 is an extracellular protein that is expressed in the vascular basement membrane. It regulates elastic fiber assembly and hence provides integrity in aortic structure. This study investigates the expression profiles of genes responsible for the elastolysis in the dissected human aorta, especially those coding fibulin-1, matrix metalloproteinase-9 (MMP-9), and elastin.

METHODS

Intraoperative aortic samples were obtained from Chinese patients with Stanford Type A aortic dissection. Both the ascending dissected aortas (primary tear) and the adjacent intact aortas were collected for comparison. Control aortic tissues were obtained from healthy organ donors. The gene profile study was determined by the Affymetrix HG-U133A GeneChip (Affymetrix, Santa Clara, Calif) and analyzed by GeneSpring GX11.0 (Agilent Technologies Inc, Palo Alto, Calif). Only the genes displaying a net signal intensity two-fold higher than the mean background were used for analysis. To evaluate elastin expression, aortic sections were stained with Movat pentachrome stain. Fibulin-1, MMP-9, and elastin mRNA and protein expression were further confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting, respectively.

RESULTS

Eight male Chinese aortic dissection patients (mean age, 45.8 years) and eight gender- and age-matched organ donors were recruited for the study. On the Affymetrix platform, 2,250 of 22,283 genes (10.1%) were detectable. The dissected and adjacent macroscopically intact aorta displayed similar gene expression patterns. In contrast, 11.2% (252) of the detectable genes were differentially expressed in the dissected and control aortas. Of these, 102 genes were upregulated, and 150 genes were downregulated. Based on the gene ontology, genes that code for extracellular matrix protein components and regulating elastic fiber assembly, like fibulin-1 and elastin, were downregulated, while enzymes like MMP-9 and MMP-11 that degrade matrix proteins were upregulated in dissected aortas. RT-PCR and Western blot results further validated the results.

CONCLUSIONS

Our gender- and age-matched study demonstrated that the alternated genes in the elastin assembly of dissected aortas may predispose structural failure in the aorta leading to dissection. However, no significant gene alterations in the adjacent intact and dissected aortas of the same patient can be found. Therefore, the genetic changes found in the dissected aortas most likely developed before the dissection starts. The inhibition of the aberrant expression of the fibulin-1 gene and that of the related matrix proteinase may open a new avenue for preventing aortic dissection.

Biomarkers in aortic dissection

Aortic dissection (AD) is a severe cardiovascular disease with high mortality and morbidity, which is characterized by acute onset and rapid progress. Mechanically, it has been considered that circulating blood flows into the media of the aorta through the rupture of the intima forming true and false lumens. Generally, its pathologic process is considered as follows: initially, inflammatory reaction, inflammatory cells infiltration in aortic wall, and then apoptosis of vascular smooth muscle cells, degenerating of aortic media, elastin fracture, and degradation. At last, the ingredients of the aorta are destroyed and lead to aortic dilatation, aneurysm formation, dissection and rupture. Currently, several biomarkers in peripheral blood including C-reactive protein (CRP), matrix metalloproteinases (MMPs), soluble elastin fragments (sELAF), D-dimer, smooth muscle myosin heavy chain, calponin, N-terminal pro-brain natriuretic peptide (NT-proBNP), big endothelin-1 (Big ET-1), genetic markers and so on, have been demonstrated to play a major role in evaluation of AD, for example, making early diagnosis and classifying of AD. Additionally, those markers may also guide our treatment therapies and predict the prognosis. The aims of this review mainly focus on the clinical implications of the biomarkers in AD.