Author + information
- Judit Cubedo, PhD,
- Teresa Padró, PhD,
- Esther Peña, PhD,
- Rosa Aledo, PhD,
- Francesc Formiga, MD, PhD,
- Assumpta Ferrer, MD, PhD,
- Glòria Padrós, MD, PhD and
- Lina Badimon, PhD∗ ()
- ↵∗Cardiovascular Research Center, c/Sant Antoni MªClaret 167, 08025 Barcelona, Spain
Aging is one of the most important contributors to cardiovascular disease (CVD). Moreover, aging and CVD are important triggers of cognitive decline in older people (1). However, there is little understanding of the molecular effectors contributing to this age-related atherothrombotic risk and cognitive decline and their association with healthy longevity in the elderly. For this reason, we have investigated the plasma proteome in octogenarians in relation with cognitive decline and ischemic atherothrombotic disease.
A total of 100 community-dwelling octogenarians (age 87 ± 0 years) from the OCTABAIX (Oldest CharacTheristic and Assessments-Baix Llobregat) study (2) were included. Functional (Barthel, Lawton-Brody), cognitive (MEC [Spanish version of the Mini-Mental State Examination]) and mini-nutritional assessment (MNA) results were recorded. The differential plasma proteomic signature was investigated as previously reported (3) in 2 groups of subjects: 1) healthy octogenarians (HO) (preserved functional, cognitive, and nutritional status) without any previous clinical manifestation of CVD (n = 10); and 2) unhealthy octogenarians (UHO) with cognitive decline (MEC <24), functional dependency (Barthel <90), and malnutrition (MNA <23.5) who had had a previous cardiovascular ischemic event (acute myocardial infarction and/or stroke) and were treated to guidelines (n = 8). Enzyme-linked immunosorbent assay validation was performed in 100 subjects: 38 HO, 27 UHO, and 35 HO with a previous cardiovascular ischemic event (HO-CVD). Fibrin clot formation/lysis was tested by confocal microscopy. The “IDIAP-Jordi Gol” Ethics Committee approved the project, and it was conducted according to the principles of Helsinki’s Declaration, with written informed consent. The statistical analysis was performed according to the sample size and the dataset distribution in each case. A p value ≤0.05 (2-sided test) was considered significant.
Alpha-2-antiplasmin (A2AP) (p = 0.008) and coagulation factor XIII B-chain (FXIIIB) (p = 0.012) were increased in the plasma proteome of UHO patients when compared with HO individuals (Figure 1A), and were positively correlated (rho = 0.732; p = 0.005), highlighting a coordinated increase in the antifibrinolytic pathway (Figure 1B). FXIIIB was inversely correlated with MNA (rho = −0.588; p = 0.019) and Lawton-Brody (rho = −0.544; p = 0.03), which has been reported to be an independent predictor of 3-year mortality (3).
Validation studies (enzyme-linked immunosorbent assay) confirmed the proteomic results. A2AP levels were lower in HO than in HO-CVD (p = 0.038) and UHO subjects (p = 0.032) (Figure 1C). FXIII levels were also lower in HO subjects than in UHO (p = 0.008) (Figure 1C) but not HO-CVD subjects. Subjects without CVD had lower A2AP levels than those who experienced CVD (p = 0.014). Whereas those with preserved cognitive, functional, and nutritional status (independently of CVD) showed decreased FXIII levels compared with UHO subjects (p = 0.01). Patients with cognitive decline (MEC <24) showed higher FXIII levels (p = 0.04). In multivariate analysis, including pharmacological treatment, only FXIII and A2AP levels remained as independent predictors of unhealthy phenotype and CVD.
Plasma from UHO patients formed clots with larger fiber diameter (p = 0.0002) and decreased pore size (p = 0.0007) (Figure 1D), resulting in a tighter fibrin network (Figure 1E) with a slower fibrinolytic rate (135 μm/h) than those from HO individuals (232 μm/h).
Genetic testing showed that the healthy phenotype was not associated with any polymorphism detected in the FXIIIB gene.
In the present study, we have identified a coordinated decrease in plasma levels of 2 antifibrinolytic proteins, A2AP and FXIII, in HO subjects without any previous episode of CVD, suggesting that an active spontaneous fibrinolysis protects against CVD and cognitive impairment. A2AP is the main serine-protease inhibitor controlling the dissolution of fibrin polymers by inhibiting plasmin activity (4). Coagulation factor XIII cross-links A2AP into the fibrin network and promotes intramolecular cross-links between fibrin strands, forming stable clots with an increased fiber density and a decreased proteolytic vulnerability (5). Thus, our confocal studies have revealed that increased levels of antifibrinolytic proteins in UHO with a previous CVD event are associated with the formation of denser fibrin clots with a decreased fibrinolytic response.
Interestingly, we have found that changes in FXIII are associated with cognitive status in the elderly, whereas changes in A2AP are associated with CVD event presentation, highlighting that the combination of both proteins could provide information about the global health status in the elderly.
In conclusion, the coordinated increase in antifibrinolytic proteins induces a phenotype with reduced spontaneous fibrinolysis and, hence, a diminished capability for spontaneous thrombus resolution in octogenarians with cognitive decline, CVD, and unhealthy longevity. Further studies are warranted to longitudinally analyze the effect of these antifibrinolytic markers in the aging process.
Please note: Fundación de Investigación Cardiovascular–Fundacion Jesús Serra has provided continuous support. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness of Science (SAF2013-42962-R to Dr. Badimon); Spanish Ministry of Health “Instituto de Mayores y Servicios Sociales” (IMSERSO 113/2011 to Dr. Padró); and FEDER “Una manera de hacer Europa” and Institute of Health Carlos III, ISCIII (RIC RD12/0042/0027 and TERCEL RD12/0019/0026 to Dr. Badimon and PI13/02850 to Dr. Padró). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Cubedo and Padró contributed equally to this work.
- 2015 American College of Cardiology Foundation