Sara Tallón-Lorenzo1, Juan Francisco Crespo-Cerezo1, Alicia Flores-Roco1,2, Jes S. Lindholt3, Jose Luis Martin-Ventura4,5, Ricardo Villa-Bellosta1,2,6
Affiliation(s):
1. center For Research In Molecular Medicine And Chronic Diseases (cimus). Campus Vida. University Of Santiago De Compostela. 15782 Santiago De Compostela, Spain.
2. health Research Institute Of Santiago De Compostela (idis), Travesia Da Choupana S/n, 15706 Santiago De Compostela, Spain
3. department Of Cardiothoracic And Vascular Surgery, Center For Individualized Medicine In Arterial Diseases, Odense University Hospital, Odense, Denmark
4. vascular Lab, Instituto De Investigacion Sanitaria Fundacion Jimenez-diaz- Autonoma University Of Madrid (iis-fjd, Uam), Madrid, Spain
5. Ciber De Enfermedades Cardiovasculares (cibercv), Madrid, Spain
6. Department Of Biochemistry And Molecular Biology. University Of Santiago De Compostela. 15782 Santiago De Compostela, Spain
Abdominal aortic aneurysm (AAA) is often associated with vascular calcification, the calcium-phosphate crystal deposition in the aortic wall, which could impact aneurysm progression and/or stability. Tissue-nonspecific alkaline phosphatase (TNAP) hydrolyzes pyrophosphate—a natural inhibitor of calcification—thereby promoting calcium deposition.
This study analyzes phosphatase activity and pyrophosphate dynamics in the plasma of AAA patients, randomly selected from the whole VIVA cohort, including controls (n=48, aortic diameter in <3 cm) and small AAA patients (n=96, aortic diameter: 3-5.5 cm), which were stratified by growth rate (low: < 2 cm/y or high > 2 cm/y, n=48 in each group), initially adjusted by aortic diameter. The phosphatase activity was assessed at physiological (7.4) and optimal (10.5) pH levels. Phosphatase activity was significantly higher in AAA patients at physiological pH, a pattern absent at optimal pH, suggesting disease-specific alterations. Small AAA patients showed notably higher phosphatase activity and pyrophosphate hydrolysis than controls at physiological pH. An inverse correlation was also observed between phosphatase activity and aortic growth rate.